2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The MAINTAINERS file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm925t Files specific to ARM 925 CPUs
143 /arm926ejs Files specific to ARM 926 CPUs
144 /arm1136 Files specific to ARM 1136 CPUs
145 /ixp Files specific to Intel XScale IXP CPUs
146 /pxa Files specific to Intel XScale PXA CPUs
147 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
148 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
149 /lib Architecture specific library files
150 /avr32 Files generic to AVR32 architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /blackfin Files generic to Analog Devices Blackfin architecture
154 /cpu CPU specific files
155 /lib Architecture specific library files
156 /x86 Files generic to x86 architecture
157 /cpu CPU specific files
158 /lib Architecture specific library files
159 /m68k Files generic to m68k architecture
160 /cpu CPU specific files
161 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
162 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
163 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
164 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
165 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
166 /lib Architecture specific library files
167 /microblaze Files generic to microblaze architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /mips Files generic to MIPS architecture
171 /cpu CPU specific files
172 /mips32 Files specific to MIPS32 CPUs
173 /xburst Files specific to Ingenic XBurst CPUs
174 /lib Architecture specific library files
175 /nds32 Files generic to NDS32 architecture
176 /cpu CPU specific files
177 /n1213 Files specific to Andes Technology N1213 CPUs
178 /lib Architecture specific library files
179 /nios2 Files generic to Altera NIOS2 architecture
180 /cpu CPU specific files
181 /lib Architecture specific library files
182 /powerpc Files generic to PowerPC architecture
183 /cpu CPU specific files
184 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc824x Files specific to Freescale MPC824x CPUs
189 /mpc8260 Files specific to Freescale MPC8260 CPUs
190 /mpc85xx Files specific to Freescale MPC85xx CPUs
191 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
192 /lib Architecture specific library files
193 /sh Files generic to SH architecture
194 /cpu CPU specific files
195 /sh2 Files specific to sh2 CPUs
196 /sh3 Files specific to sh3 CPUs
197 /sh4 Files specific to sh4 CPUs
198 /lib Architecture specific library files
199 /sparc Files generic to SPARC architecture
200 /cpu CPU specific files
201 /leon2 Files specific to Gaisler LEON2 SPARC CPU
202 /leon3 Files specific to Gaisler LEON3 SPARC CPU
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /examples Example code for standalone applications, etc.
211 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
212 /include Header Files
213 /lib Files generic to all architectures
214 /libfdt Library files to support flattened device trees
215 /lzma Library files to support LZMA decompression
216 /lzo Library files to support LZO decompression
218 /post Power On Self Test
219 /rtc Real Time Clock drivers
220 /tools Tools to build S-Record or U-Boot images, etc.
222 Software Configuration:
223 =======================
225 Configuration is usually done using C preprocessor defines; the
226 rationale behind that is to avoid dead code whenever possible.
228 There are two classes of configuration variables:
230 * Configuration _OPTIONS_:
231 These are selectable by the user and have names beginning with
234 * Configuration _SETTINGS_:
235 These depend on the hardware etc. and should not be meddled with if
236 you don't know what you're doing; they have names beginning with
239 Later we will add a configuration tool - probably similar to or even
240 identical to what's used for the Linux kernel. Right now, we have to
241 do the configuration by hand, which means creating some symbolic
242 links and editing some configuration files. We use the TQM8xxL boards
246 Selection of Processor Architecture and Board Type:
247 ---------------------------------------------------
249 For all supported boards there are ready-to-use default
250 configurations available; just type "make <board_name>_config".
252 Example: For a TQM823L module type:
257 For the Cogent platform, you need to specify the CPU type as well;
258 e.g. "make cogent_mpc8xx_config". And also configure the cogent
259 directory according to the instructions in cogent/README.
262 Configuration Options:
263 ----------------------
265 Configuration depends on the combination of board and CPU type; all
266 such information is kept in a configuration file
267 "include/configs/<board_name>.h".
269 Example: For a TQM823L module, all configuration settings are in
270 "include/configs/TQM823L.h".
273 Many of the options are named exactly as the corresponding Linux
274 kernel configuration options. The intention is to make it easier to
275 build a config tool - later.
278 The following options need to be configured:
280 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
282 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
284 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
285 Define exactly one, e.g. CONFIG_ATSTK1002
287 - CPU Module Type: (if CONFIG_COGENT is defined)
288 Define exactly one of
290 --- FIXME --- not tested yet:
291 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
292 CONFIG_CMA287_23, CONFIG_CMA287_50
294 - Motherboard Type: (if CONFIG_COGENT is defined)
295 Define exactly one of
296 CONFIG_CMA101, CONFIG_CMA102
298 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
299 Define one or more of
302 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
303 Define one or more of
304 CONFIG_LCD_HEARTBEAT - update a character position on
305 the LCD display every second with
308 - Board flavour: (if CONFIG_MPC8260ADS is defined)
311 CONFIG_SYS_8260ADS - original MPC8260ADS
312 CONFIG_SYS_8266ADS - MPC8266ADS
313 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
314 CONFIG_SYS_8272ADS - MPC8272ADS
316 - Marvell Family Member
317 CONFIG_SYS_MVFS - define it if you want to enable
318 multiple fs option at one time
319 for marvell soc family
321 - MPC824X Family Member (if CONFIG_MPC824X is defined)
322 Define exactly one of
323 CONFIG_MPC8240, CONFIG_MPC8245
325 - 8xx CPU Options: (if using an MPC8xx CPU)
326 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
327 get_gclk_freq() cannot work
328 e.g. if there is no 32KHz
329 reference PIT/RTC clock
330 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
333 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
334 CONFIG_SYS_8xx_CPUCLK_MIN
335 CONFIG_SYS_8xx_CPUCLK_MAX
336 CONFIG_8xx_CPUCLK_DEFAULT
337 See doc/README.MPC866
339 CONFIG_SYS_MEASURE_CPUCLK
341 Define this to measure the actual CPU clock instead
342 of relying on the correctness of the configured
343 values. Mostly useful for board bringup to make sure
344 the PLL is locked at the intended frequency. Note
345 that this requires a (stable) reference clock (32 kHz
346 RTC clock or CONFIG_SYS_8XX_XIN)
348 CONFIG_SYS_DELAYED_ICACHE
350 Define this option if you want to enable the
351 ICache only when Code runs from RAM.
356 Specifies that the core is a 64-bit PowerPC implementation (implements
357 the "64" category of the Power ISA). This is necessary for ePAPR
358 compliance, among other possible reasons.
360 CONFIG_SYS_FSL_TBCLK_DIV
362 Defines the core time base clock divider ratio compared to the
363 system clock. On most PQ3 devices this is 8, on newer QorIQ
364 devices it can be 16 or 32. The ratio varies from SoC to Soc.
366 CONFIG_SYS_FSL_PCIE_COMPAT
368 Defines the string to utilize when trying to match PCIe device
369 tree nodes for the given platform.
371 CONFIG_SYS_PPC_E500_DEBUG_TLB
373 Enables a temporary TLB entry to be used during boot to work
374 around limitations in e500v1 and e500v2 external debugger
375 support. This reduces the portions of the boot code where
376 breakpoints and single stepping do not work. The value of this
377 symbol should be set to the TLB1 entry to be used for this
380 CONFIG_SYS_FSL_ERRATUM_A004510
382 Enables a workaround for erratum A004510. If set,
383 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
384 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
386 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
389 Defines one or two SoC revisions (low 8 bits of SVR)
390 for which the A004510 workaround should be applied.
392 The rest of SVR is either not relevant to the decision
393 of whether the erratum is present (e.g. p2040 versus
394 p2041) or is implied by the build target, which controls
395 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
397 See Freescale App Note 4493 for more information about
400 CONFIG_A003399_NOR_WORKAROUND
401 Enables a workaround for IFC erratum A003399. It is only
402 requred during NOR boot.
404 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
406 This is the value to write into CCSR offset 0x18600
407 according to the A004510 workaround.
409 CONFIG_SYS_FSL_DSP_DDR_ADDR
410 This value denotes start offset of DDR memory which is
411 connected exclusively to the DSP cores.
413 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
414 This value denotes start offset of M2 memory
415 which is directly connected to the DSP core.
417 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
418 This value denotes start offset of M3 memory which is directly
419 connected to the DSP core.
421 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
422 This value denotes start offset of DSP CCSR space.
424 CONFIG_SYS_FSL_DDR_EMU
425 Specify emulator support for DDR. Some DDR features such as
426 deskew training are not available.
428 - Generic CPU options:
429 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
431 Defines the endianess of the CPU. Implementation of those
432 values is arch specific.
434 - Intel Monahans options:
435 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
437 Defines the Monahans run mode to oscillator
438 ratio. Valid values are 8, 16, 24, 31. The core
439 frequency is this value multiplied by 13 MHz.
441 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
443 Defines the Monahans turbo mode to oscillator
444 ratio. Valid values are 1 (default if undefined) and
445 2. The core frequency as calculated above is multiplied
449 CONFIG_SYS_INIT_SP_OFFSET
451 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
452 pointer. This is needed for the temporary stack before
455 CONFIG_SYS_MIPS_CACHE_MODE
457 Cache operation mode for the MIPS CPU.
458 See also arch/mips/include/asm/mipsregs.h.
460 CONF_CM_CACHABLE_NO_WA
463 CONF_CM_CACHABLE_NONCOHERENT
467 CONF_CM_CACHABLE_ACCELERATED
469 CONFIG_SYS_XWAY_EBU_BOOTCFG
471 Special option for Lantiq XWAY SoCs for booting from NOR flash.
472 See also arch/mips/cpu/mips32/start.S.
474 CONFIG_XWAY_SWAP_BYTES
476 Enable compilation of tools/xway-swap-bytes needed for Lantiq
477 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
478 be swapped if a flash programmer is used.
481 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
483 Select high exception vectors of the ARM core, e.g., do not
484 clear the V bit of the c1 register of CP15.
486 CONFIG_SYS_THUMB_BUILD
488 Use this flag to build U-Boot using the Thumb instruction
489 set for ARM architectures. Thumb instruction set provides
490 better code density. For ARM architectures that support
491 Thumb2 this flag will result in Thumb2 code generated by
494 CONFIG_ARM_ERRATA_716044
495 CONFIG_ARM_ERRATA_742230
496 CONFIG_ARM_ERRATA_743622
497 CONFIG_ARM_ERRATA_751472
499 If set, the workarounds for these ARM errata are applied early
500 during U-Boot startup. Note that these options force the
501 workarounds to be applied; no CPU-type/version detection
502 exists, unlike the similar options in the Linux kernel. Do not
503 set these options unless they apply!
508 The frequency of the timer returned by get_timer().
509 get_timer() must operate in milliseconds and this CONFIG
510 option must be set to 1000.
512 - Linux Kernel Interface:
515 U-Boot stores all clock information in Hz
516 internally. For binary compatibility with older Linux
517 kernels (which expect the clocks passed in the
518 bd_info data to be in MHz) the environment variable
519 "clocks_in_mhz" can be defined so that U-Boot
520 converts clock data to MHZ before passing it to the
522 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
523 "clocks_in_mhz=1" is automatically included in the
526 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
528 When transferring memsize parameter to linux, some versions
529 expect it to be in bytes, others in MB.
530 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
534 New kernel versions are expecting firmware settings to be
535 passed using flattened device trees (based on open firmware
539 * New libfdt-based support
540 * Adds the "fdt" command
541 * The bootm command automatically updates the fdt
543 OF_CPU - The proper name of the cpus node (only required for
544 MPC512X and MPC5xxx based boards).
545 OF_SOC - The proper name of the soc node (only required for
546 MPC512X and MPC5xxx based boards).
547 OF_TBCLK - The timebase frequency.
548 OF_STDOUT_PATH - The path to the console device
550 boards with QUICC Engines require OF_QE to set UCC MAC
553 CONFIG_OF_BOARD_SETUP
555 Board code has addition modification that it wants to make
556 to the flat device tree before handing it off to the kernel
560 This define fills in the correct boot CPU in the boot
561 param header, the default value is zero if undefined.
565 U-Boot can detect if an IDE device is present or not.
566 If not, and this new config option is activated, U-Boot
567 removes the ATA node from the DTS before booting Linux,
568 so the Linux IDE driver does not probe the device and
569 crash. This is needed for buggy hardware (uc101) where
570 no pull down resistor is connected to the signal IDE5V_DD7.
572 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
574 This setting is mandatory for all boards that have only one
575 machine type and must be used to specify the machine type
576 number as it appears in the ARM machine registry
577 (see http://www.arm.linux.org.uk/developer/machines/).
578 Only boards that have multiple machine types supported
579 in a single configuration file and the machine type is
580 runtime discoverable, do not have to use this setting.
582 - vxWorks boot parameters:
584 bootvx constructs a valid bootline using the following
585 environments variables: bootfile, ipaddr, serverip, hostname.
586 It loads the vxWorks image pointed bootfile.
588 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
589 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
590 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
591 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
593 CONFIG_SYS_VXWORKS_ADD_PARAMS
595 Add it at the end of the bootline. E.g "u=username pw=secret"
597 Note: If a "bootargs" environment is defined, it will overwride
598 the defaults discussed just above.
600 - Cache Configuration:
601 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
602 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
603 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
605 - Cache Configuration for ARM:
606 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
608 CONFIG_SYS_PL310_BASE - Physical base address of PL310
609 controller register space
614 Define this if you want support for Amba PrimeCell PL010 UARTs.
618 Define this if you want support for Amba PrimeCell PL011 UARTs.
622 If you have Amba PrimeCell PL011 UARTs, set this variable to
623 the clock speed of the UARTs.
627 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
628 define this to a list of base addresses for each (supported)
629 port. See e.g. include/configs/versatile.h
631 CONFIG_PL011_SERIAL_RLCR
633 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
634 have separate receive and transmit line control registers. Set
635 this variable to initialize the extra register.
637 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
639 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
640 boot loader that has already initialized the UART. Define this
641 variable to flush the UART at init time.
645 Depending on board, define exactly one serial port
646 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
647 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
648 console by defining CONFIG_8xx_CONS_NONE
650 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
651 port routines must be defined elsewhere
652 (i.e. serial_init(), serial_getc(), ...)
655 Enables console device for a color framebuffer. Needs following
656 defines (cf. smiLynxEM, i8042)
657 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
659 VIDEO_HW_RECTFILL graphic chip supports
662 VIDEO_HW_BITBLT graphic chip supports
663 bit-blit (cf. smiLynxEM)
664 VIDEO_VISIBLE_COLS visible pixel columns
666 VIDEO_VISIBLE_ROWS visible pixel rows
667 VIDEO_PIXEL_SIZE bytes per pixel
668 VIDEO_DATA_FORMAT graphic data format
669 (0-5, cf. cfb_console.c)
670 VIDEO_FB_ADRS framebuffer address
671 VIDEO_KBD_INIT_FCT keyboard int fct
672 (i.e. i8042_kbd_init())
673 VIDEO_TSTC_FCT test char fct
675 VIDEO_GETC_FCT get char fct
677 CONFIG_CONSOLE_CURSOR cursor drawing on/off
678 (requires blink timer
680 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
681 CONFIG_CONSOLE_TIME display time/date info in
683 (requires CONFIG_CMD_DATE)
684 CONFIG_VIDEO_LOGO display Linux logo in
686 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
687 linux_logo.h for logo.
688 Requires CONFIG_VIDEO_LOGO
689 CONFIG_CONSOLE_EXTRA_INFO
690 additional board info beside
693 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
694 a limited number of ANSI escape sequences (cursor control,
695 erase functions and limited graphics rendition control).
697 When CONFIG_CFB_CONSOLE is defined, video console is
698 default i/o. Serial console can be forced with
699 environment 'console=serial'.
701 When CONFIG_SILENT_CONSOLE is defined, all console
702 messages (by U-Boot and Linux!) can be silenced with
703 the "silent" environment variable. See
704 doc/README.silent for more information.
707 CONFIG_BAUDRATE - in bps
708 Select one of the baudrates listed in
709 CONFIG_SYS_BAUDRATE_TABLE, see below.
710 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
712 - Console Rx buffer length
713 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
714 the maximum receive buffer length for the SMC.
715 This option is actual only for 82xx and 8xx possible.
716 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
717 must be defined, to setup the maximum idle timeout for
720 - Pre-Console Buffer:
721 Prior to the console being initialised (i.e. serial UART
722 initialised etc) all console output is silently discarded.
723 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
724 buffer any console messages prior to the console being
725 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
726 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
727 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
728 bytes are output before the console is initialised, the
729 earlier bytes are discarded.
731 'Sane' compilers will generate smaller code if
732 CONFIG_PRE_CON_BUF_SZ is a power of 2
734 - Safe printf() functions
735 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
736 the printf() functions. These are defined in
737 include/vsprintf.h and include snprintf(), vsnprintf() and
738 so on. Code size increase is approximately 300-500 bytes.
739 If this option is not given then these functions will
740 silently discard their buffer size argument - this means
741 you are not getting any overflow checking in this case.
743 - Boot Delay: CONFIG_BOOTDELAY - in seconds
744 Delay before automatically booting the default image;
745 set to -1 to disable autoboot.
746 set to -2 to autoboot with no delay and not check for abort
747 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
749 See doc/README.autoboot for these options that
750 work with CONFIG_BOOTDELAY. None are required.
751 CONFIG_BOOT_RETRY_TIME
752 CONFIG_BOOT_RETRY_MIN
753 CONFIG_AUTOBOOT_KEYED
754 CONFIG_AUTOBOOT_PROMPT
755 CONFIG_AUTOBOOT_DELAY_STR
756 CONFIG_AUTOBOOT_STOP_STR
757 CONFIG_AUTOBOOT_DELAY_STR2
758 CONFIG_AUTOBOOT_STOP_STR2
759 CONFIG_ZERO_BOOTDELAY_CHECK
760 CONFIG_RESET_TO_RETRY
764 Only needed when CONFIG_BOOTDELAY is enabled;
765 define a command string that is automatically executed
766 when no character is read on the console interface
767 within "Boot Delay" after reset.
770 This can be used to pass arguments to the bootm
771 command. The value of CONFIG_BOOTARGS goes into the
772 environment value "bootargs".
774 CONFIG_RAMBOOT and CONFIG_NFSBOOT
775 The value of these goes into the environment as
776 "ramboot" and "nfsboot" respectively, and can be used
777 as a convenience, when switching between booting from
783 When this option is #defined, the existence of the
784 environment variable "preboot" will be checked
785 immediately before starting the CONFIG_BOOTDELAY
786 countdown and/or running the auto-boot command resp.
787 entering interactive mode.
789 This feature is especially useful when "preboot" is
790 automatically generated or modified. For an example
791 see the LWMON board specific code: here "preboot" is
792 modified when the user holds down a certain
793 combination of keys on the (special) keyboard when
796 - Serial Download Echo Mode:
798 If defined to 1, all characters received during a
799 serial download (using the "loads" command) are
800 echoed back. This might be needed by some terminal
801 emulations (like "cu"), but may as well just take
802 time on others. This setting #define's the initial
803 value of the "loads_echo" environment variable.
805 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
807 Select one of the baudrates listed in
808 CONFIG_SYS_BAUDRATE_TABLE, see below.
811 Monitor commands can be included or excluded
812 from the build by using the #include files
813 <config_cmd_all.h> and #undef'ing unwanted
814 commands, or using <config_cmd_default.h>
815 and augmenting with additional #define's
818 The default command configuration includes all commands
819 except those marked below with a "*".
821 CONFIG_CMD_ASKENV * ask for env variable
822 CONFIG_CMD_BDI bdinfo
823 CONFIG_CMD_BEDBUG * Include BedBug Debugger
824 CONFIG_CMD_BMP * BMP support
825 CONFIG_CMD_BSP * Board specific commands
826 CONFIG_CMD_BOOTD bootd
827 CONFIG_CMD_CACHE * icache, dcache
828 CONFIG_CMD_CONSOLE coninfo
829 CONFIG_CMD_CRC32 * crc32
830 CONFIG_CMD_DATE * support for RTC, date/time...
831 CONFIG_CMD_DHCP * DHCP support
832 CONFIG_CMD_DIAG * Diagnostics
833 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
834 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
835 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
836 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
837 CONFIG_CMD_DTT * Digital Therm and Thermostat
838 CONFIG_CMD_ECHO echo arguments
839 CONFIG_CMD_EDITENV edit env variable
840 CONFIG_CMD_EEPROM * EEPROM read/write support
841 CONFIG_CMD_ELF * bootelf, bootvx
842 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
843 CONFIG_CMD_ENV_FLAGS * display details about env flags
844 CONFIG_CMD_EXPORTENV * export the environment
845 CONFIG_CMD_EXT2 * ext2 command support
846 CONFIG_CMD_EXT4 * ext4 command support
847 CONFIG_CMD_SAVEENV saveenv
848 CONFIG_CMD_FDC * Floppy Disk Support
849 CONFIG_CMD_FAT * FAT command support
850 CONFIG_CMD_FDOS * Dos diskette Support
851 CONFIG_CMD_FLASH flinfo, erase, protect
852 CONFIG_CMD_FPGA FPGA device initialization support
853 CONFIG_CMD_FUSE * Device fuse support
854 CONFIG_CMD_GETTIME * Get time since boot
855 CONFIG_CMD_GO * the 'go' command (exec code)
856 CONFIG_CMD_GREPENV * search environment
857 CONFIG_CMD_HASH * calculate hash / digest
858 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
859 CONFIG_CMD_I2C * I2C serial bus support
860 CONFIG_CMD_IDE * IDE harddisk support
861 CONFIG_CMD_IMI iminfo
862 CONFIG_CMD_IMLS List all images found in NOR flash
863 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
864 CONFIG_CMD_IMMAP * IMMR dump support
865 CONFIG_CMD_IMPORTENV * import an environment
866 CONFIG_CMD_INI * import data from an ini file into the env
867 CONFIG_CMD_IRQ * irqinfo
868 CONFIG_CMD_ITEST Integer/string test of 2 values
869 CONFIG_CMD_JFFS2 * JFFS2 Support
870 CONFIG_CMD_KGDB * kgdb
871 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
872 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
874 CONFIG_CMD_LOADB loadb
875 CONFIG_CMD_LOADS loads
876 CONFIG_CMD_MD5SUM * print md5 message digest
877 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
878 CONFIG_CMD_MEMINFO * Display detailed memory information
879 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
881 CONFIG_CMD_MEMTEST * mtest
882 CONFIG_CMD_MISC Misc functions like sleep etc
883 CONFIG_CMD_MMC * MMC memory mapped support
884 CONFIG_CMD_MII * MII utility commands
885 CONFIG_CMD_MTDPARTS * MTD partition support
886 CONFIG_CMD_NAND * NAND support
887 CONFIG_CMD_NET bootp, tftpboot, rarpboot
888 CONFIG_CMD_NFS NFS support
889 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
890 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
891 CONFIG_CMD_PCI * pciinfo
892 CONFIG_CMD_PCMCIA * PCMCIA support
893 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
895 CONFIG_CMD_PORTIO * Port I/O
896 CONFIG_CMD_READ * Read raw data from partition
897 CONFIG_CMD_REGINFO * Register dump
898 CONFIG_CMD_RUN run command in env variable
899 CONFIG_CMD_SANDBOX * sb command to access sandbox features
900 CONFIG_CMD_SAVES * save S record dump
901 CONFIG_CMD_SCSI * SCSI Support
902 CONFIG_CMD_SDRAM * print SDRAM configuration information
903 (requires CONFIG_CMD_I2C)
904 CONFIG_CMD_SETGETDCR Support for DCR Register access
906 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
907 CONFIG_CMD_SHA1SUM * print sha1 memory digest
908 (requires CONFIG_CMD_MEMORY)
909 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
910 CONFIG_CMD_SOURCE "source" command Support
911 CONFIG_CMD_SPI * SPI serial bus support
912 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
913 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
914 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
915 CONFIG_CMD_TIMER * access to the system tick timer
916 CONFIG_CMD_USB * USB support
917 CONFIG_CMD_CDP * Cisco Discover Protocol support
918 CONFIG_CMD_MFSL * Microblaze FSL support
919 CONFIG_CMD_XIMG Load part of Multi Image
922 EXAMPLE: If you want all functions except of network
923 support you can write:
925 #include "config_cmd_all.h"
926 #undef CONFIG_CMD_NET
929 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
931 Note: Don't enable the "icache" and "dcache" commands
932 (configuration option CONFIG_CMD_CACHE) unless you know
933 what you (and your U-Boot users) are doing. Data
934 cache cannot be enabled on systems like the 8xx or
935 8260 (where accesses to the IMMR region must be
936 uncached), and it cannot be disabled on all other
937 systems where we (mis-) use the data cache to hold an
938 initial stack and some data.
941 XXX - this list needs to get updated!
943 - Regular expression support:
945 If this variable is defined, U-Boot is linked against
946 the SLRE (Super Light Regular Expression) library,
947 which adds regex support to some commands, as for
948 example "env grep" and "setexpr".
952 If this variable is defined, U-Boot will use a device tree
953 to configure its devices, instead of relying on statically
954 compiled #defines in the board file. This option is
955 experimental and only available on a few boards. The device
956 tree is available in the global data as gd->fdt_blob.
958 U-Boot needs to get its device tree from somewhere. This can
959 be done using one of the two options below:
962 If this variable is defined, U-Boot will embed a device tree
963 binary in its image. This device tree file should be in the
964 board directory and called <soc>-<board>.dts. The binary file
965 is then picked up in board_init_f() and made available through
966 the global data structure as gd->blob.
969 If this variable is defined, U-Boot will build a device tree
970 binary. It will be called u-boot.dtb. Architecture-specific
971 code will locate it at run-time. Generally this works by:
973 cat u-boot.bin u-boot.dtb >image.bin
975 and in fact, U-Boot does this for you, creating a file called
976 u-boot-dtb.bin which is useful in the common case. You can
977 still use the individual files if you need something more
982 If this variable is defined, it enables watchdog
983 support for the SoC. There must be support in the SoC
984 specific code for a watchdog. For the 8xx and 8260
985 CPUs, the SIU Watchdog feature is enabled in the SYPCR
986 register. When supported for a specific SoC is
987 available, then no further board specific code should
991 When using a watchdog circuitry external to the used
992 SoC, then define this variable and provide board
993 specific code for the "hw_watchdog_reset" function.
996 CONFIG_VERSION_VARIABLE
997 If this variable is defined, an environment variable
998 named "ver" is created by U-Boot showing the U-Boot
999 version as printed by the "version" command.
1000 Any change to this variable will be reverted at the
1005 When CONFIG_CMD_DATE is selected, the type of the RTC
1006 has to be selected, too. Define exactly one of the
1009 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1010 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1011 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1012 CONFIG_RTC_MC146818 - use MC146818 RTC
1013 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1014 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1015 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1016 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1017 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1018 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1019 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1020 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1023 Note that if the RTC uses I2C, then the I2C interface
1024 must also be configured. See I2C Support, below.
1027 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1028 CONFIG_PCA953X_INFO - enable pca953x info command
1030 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1031 chip-ngpio pairs that tell the PCA953X driver the number of
1032 pins supported by a particular chip.
1034 Note that if the GPIO device uses I2C, then the I2C interface
1035 must also be configured. See I2C Support, below.
1037 - Timestamp Support:
1039 When CONFIG_TIMESTAMP is selected, the timestamp
1040 (date and time) of an image is printed by image
1041 commands like bootm or iminfo. This option is
1042 automatically enabled when you select CONFIG_CMD_DATE .
1044 - Partition Labels (disklabels) Supported:
1045 Zero or more of the following:
1046 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1047 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1048 Intel architecture, USB sticks, etc.
1049 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1050 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1051 bootloader. Note 2TB partition limit; see
1053 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1055 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1056 CONFIG_CMD_SCSI) you must configure support for at
1057 least one non-MTD partition type as well.
1060 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1061 board configurations files but used nowhere!
1063 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1064 be performed by calling the function
1065 ide_set_reset(int reset)
1066 which has to be defined in a board specific file
1071 Set this to enable ATAPI support.
1076 Set this to enable support for disks larger than 137GB
1077 Also look at CONFIG_SYS_64BIT_LBA.
1078 Whithout these , LBA48 support uses 32bit variables and will 'only'
1079 support disks up to 2.1TB.
1081 CONFIG_SYS_64BIT_LBA:
1082 When enabled, makes the IDE subsystem use 64bit sector addresses.
1086 At the moment only there is only support for the
1087 SYM53C8XX SCSI controller; define
1088 CONFIG_SCSI_SYM53C8XX to enable it.
1090 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1091 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1092 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1093 maximum numbers of LUNs, SCSI ID's and target
1095 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1097 The environment variable 'scsidevs' is set to the number of
1098 SCSI devices found during the last scan.
1100 - NETWORK Support (PCI):
1102 Support for Intel 8254x/8257x gigabit chips.
1105 Utility code for direct access to the SPI bus on Intel 8257x.
1106 This does not do anything useful unless you set at least one
1107 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1109 CONFIG_E1000_SPI_GENERIC
1110 Allow generic access to the SPI bus on the Intel 8257x, for
1111 example with the "sspi" command.
1114 Management command for E1000 devices. When used on devices
1115 with SPI support you can reprogram the EEPROM from U-Boot.
1117 CONFIG_E1000_FALLBACK_MAC
1118 default MAC for empty EEPROM after production.
1121 Support for Intel 82557/82559/82559ER chips.
1122 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1123 write routine for first time initialisation.
1126 Support for Digital 2114x chips.
1127 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1128 modem chip initialisation (KS8761/QS6611).
1131 Support for National dp83815 chips.
1134 Support for National dp8382[01] gigabit chips.
1136 - NETWORK Support (other):
1138 CONFIG_DRIVER_AT91EMAC
1139 Support for AT91RM9200 EMAC.
1142 Define this to use reduced MII inteface
1144 CONFIG_DRIVER_AT91EMAC_QUIET
1145 If this defined, the driver is quiet.
1146 The driver doen't show link status messages.
1148 CONFIG_CALXEDA_XGMAC
1149 Support for the Calxeda XGMAC device
1152 Support for SMSC's LAN91C96 chips.
1154 CONFIG_LAN91C96_BASE
1155 Define this to hold the physical address
1156 of the LAN91C96's I/O space
1158 CONFIG_LAN91C96_USE_32_BIT
1159 Define this to enable 32 bit addressing
1162 Support for SMSC's LAN91C111 chip
1164 CONFIG_SMC91111_BASE
1165 Define this to hold the physical address
1166 of the device (I/O space)
1168 CONFIG_SMC_USE_32_BIT
1169 Define this if data bus is 32 bits
1171 CONFIG_SMC_USE_IOFUNCS
1172 Define this to use i/o functions instead of macros
1173 (some hardware wont work with macros)
1175 CONFIG_DRIVER_TI_EMAC
1176 Support for davinci emac
1178 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1179 Define this if you have more then 3 PHYs.
1182 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1184 CONFIG_FTGMAC100_EGIGA
1185 Define this to use GE link update with gigabit PHY.
1186 Define this if FTGMAC100 is connected to gigabit PHY.
1187 If your system has 10/100 PHY only, it might not occur
1188 wrong behavior. Because PHY usually return timeout or
1189 useless data when polling gigabit status and gigabit
1190 control registers. This behavior won't affect the
1191 correctnessof 10/100 link speed update.
1194 Support for SMSC's LAN911x and LAN921x chips
1197 Define this to hold the physical address
1198 of the device (I/O space)
1200 CONFIG_SMC911X_32_BIT
1201 Define this if data bus is 32 bits
1203 CONFIG_SMC911X_16_BIT
1204 Define this if data bus is 16 bits. If your processor
1205 automatically converts one 32 bit word to two 16 bit
1206 words you may also try CONFIG_SMC911X_32_BIT.
1209 Support for Renesas on-chip Ethernet controller
1211 CONFIG_SH_ETHER_USE_PORT
1212 Define the number of ports to be used
1214 CONFIG_SH_ETHER_PHY_ADDR
1215 Define the ETH PHY's address
1217 CONFIG_SH_ETHER_CACHE_WRITEBACK
1218 If this option is set, the driver enables cache flush.
1222 Support TPM devices.
1225 Support for i2c bus TPM devices. Only one device
1226 per system is supported at this time.
1228 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1229 Define the the i2c bus number for the TPM device
1231 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1232 Define the TPM's address on the i2c bus
1234 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1235 Define the burst count bytes upper limit
1237 CONFIG_TPM_ATMEL_TWI
1238 Support for Atmel TWI TPM device. Requires I2C support.
1241 Support for generic parallel port TPM devices. Only one device
1242 per system is supported at this time.
1244 CONFIG_TPM_TIS_BASE_ADDRESS
1245 Base address where the generic TPM device is mapped
1246 to. Contemporary x86 systems usually map it at
1250 Add tpm monitor functions.
1251 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1252 provides monitor access to authorized functions.
1255 Define this to enable the TPM support library which provides
1256 functional interfaces to some TPM commands.
1257 Requires support for a TPM device.
1259 CONFIG_TPM_AUTH_SESSIONS
1260 Define this to enable authorized functions in the TPM library.
1261 Requires CONFIG_TPM and CONFIG_SHA1.
1264 At the moment only the UHCI host controller is
1265 supported (PIP405, MIP405, MPC5200); define
1266 CONFIG_USB_UHCI to enable it.
1267 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1268 and define CONFIG_USB_STORAGE to enable the USB
1271 Supported are USB Keyboards and USB Floppy drives
1273 MPC5200 USB requires additional defines:
1275 for 528 MHz Clock: 0x0001bbbb
1279 for differential drivers: 0x00001000
1280 for single ended drivers: 0x00005000
1281 for differential drivers on PSC3: 0x00000100
1282 for single ended drivers on PSC3: 0x00004100
1283 CONFIG_SYS_USB_EVENT_POLL
1284 May be defined to allow interrupt polling
1285 instead of using asynchronous interrupts
1287 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1288 txfilltuning field in the EHCI controller on reset.
1290 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1291 interval for usb hub power-on delay.(minimum 100msec)
1294 Define the below if you wish to use the USB console.
1295 Once firmware is rebuilt from a serial console issue the
1296 command "setenv stdin usbtty; setenv stdout usbtty" and
1297 attach your USB cable. The Unix command "dmesg" should print
1298 it has found a new device. The environment variable usbtty
1299 can be set to gserial or cdc_acm to enable your device to
1300 appear to a USB host as a Linux gserial device or a
1301 Common Device Class Abstract Control Model serial device.
1302 If you select usbtty = gserial you should be able to enumerate
1304 # modprobe usbserial vendor=0xVendorID product=0xProductID
1305 else if using cdc_acm, simply setting the environment
1306 variable usbtty to be cdc_acm should suffice. The following
1307 might be defined in YourBoardName.h
1310 Define this to build a UDC device
1313 Define this to have a tty type of device available to
1314 talk to the UDC device
1317 Define this to enable the high speed support for usb
1318 device and usbtty. If this feature is enabled, a routine
1319 int is_usbd_high_speed(void)
1320 also needs to be defined by the driver to dynamically poll
1321 whether the enumeration has succeded at high speed or full
1324 CONFIG_SYS_CONSOLE_IS_IN_ENV
1325 Define this if you want stdin, stdout &/or stderr to
1329 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1330 Derive USB clock from external clock "blah"
1331 - CONFIG_SYS_USB_EXTC_CLK 0x02
1333 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1334 Derive USB clock from brgclk
1335 - CONFIG_SYS_USB_BRG_CLK 0x04
1337 If you have a USB-IF assigned VendorID then you may wish to
1338 define your own vendor specific values either in BoardName.h
1339 or directly in usbd_vendor_info.h. If you don't define
1340 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1341 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1342 should pretend to be a Linux device to it's target host.
1344 CONFIG_USBD_MANUFACTURER
1345 Define this string as the name of your company for
1346 - CONFIG_USBD_MANUFACTURER "my company"
1348 CONFIG_USBD_PRODUCT_NAME
1349 Define this string as the name of your product
1350 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1352 CONFIG_USBD_VENDORID
1353 Define this as your assigned Vendor ID from the USB
1354 Implementors Forum. This *must* be a genuine Vendor ID
1355 to avoid polluting the USB namespace.
1356 - CONFIG_USBD_VENDORID 0xFFFF
1358 CONFIG_USBD_PRODUCTID
1359 Define this as the unique Product ID
1361 - CONFIG_USBD_PRODUCTID 0xFFFF
1363 - ULPI Layer Support:
1364 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1365 the generic ULPI layer. The generic layer accesses the ULPI PHY
1366 via the platform viewport, so you need both the genric layer and
1367 the viewport enabled. Currently only Chipidea/ARC based
1368 viewport is supported.
1369 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1370 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1371 If your ULPI phy needs a different reference clock than the
1372 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1373 the appropriate value in Hz.
1376 The MMC controller on the Intel PXA is supported. To
1377 enable this define CONFIG_MMC. The MMC can be
1378 accessed from the boot prompt by mapping the device
1379 to physical memory similar to flash. Command line is
1380 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1381 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1384 Support for Renesas on-chip MMCIF controller
1386 CONFIG_SH_MMCIF_ADDR
1387 Define the base address of MMCIF registers
1390 Define the clock frequency for MMCIF
1392 - USB Device Firmware Update (DFU) class support:
1394 This enables the USB portion of the DFU USB class
1397 This enables the command "dfu" which is used to have
1398 U-Boot create a DFU class device via USB. This command
1399 requires that the "dfu_alt_info" environment variable be
1400 set and define the alt settings to expose to the host.
1403 This enables support for exposing (e)MMC devices via DFU.
1406 This enables support for exposing NAND devices via DFU.
1408 CONFIG_SYS_DFU_DATA_BUF_SIZE
1409 Dfu transfer uses a buffer before writing data to the
1410 raw storage device. Make the size (in bytes) of this buffer
1411 configurable. The size of this buffer is also configurable
1412 through the "dfu_bufsiz" environment variable.
1414 CONFIG_SYS_DFU_MAX_FILE_SIZE
1415 When updating files rather than the raw storage device,
1416 we use a static buffer to copy the file into and then write
1417 the buffer once we've been given the whole file. Define
1418 this to the maximum filesize (in bytes) for the buffer.
1419 Default is 4 MiB if undefined.
1421 - Journaling Flash filesystem support:
1422 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1423 CONFIG_JFFS2_NAND_DEV
1424 Define these for a default partition on a NAND device
1426 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1427 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1428 Define these for a default partition on a NOR device
1430 CONFIG_SYS_JFFS_CUSTOM_PART
1431 Define this to create an own partition. You have to provide a
1432 function struct part_info* jffs2_part_info(int part_num)
1434 If you define only one JFFS2 partition you may also want to
1435 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1436 to disable the command chpart. This is the default when you
1437 have not defined a custom partition
1439 - FAT(File Allocation Table) filesystem write function support:
1442 Define this to enable support for saving memory data as a
1443 file in FAT formatted partition.
1445 This will also enable the command "fatwrite" enabling the
1446 user to write files to FAT.
1448 CBFS (Coreboot Filesystem) support
1451 Define this to enable support for reading from a Coreboot
1452 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1458 Define this to enable standard (PC-Style) keyboard
1462 Standard PC keyboard driver with US (is default) and
1463 GERMAN key layout (switch via environment 'keymap=de') support.
1464 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1465 for cfb_console. Supports cursor blinking.
1468 Enables a Chrome OS keyboard using the CROS_EC interface.
1469 This uses CROS_EC to communicate with a second microcontroller
1470 which provides key scans on request.
1475 Define this to enable video support (for output to
1478 CONFIG_VIDEO_CT69000
1480 Enable Chips & Technologies 69000 Video chip
1482 CONFIG_VIDEO_SMI_LYNXEM
1483 Enable Silicon Motion SMI 712/710/810 Video chip. The
1484 video output is selected via environment 'videoout'
1485 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1488 For the CT69000 and SMI_LYNXEM drivers, videomode is
1489 selected via environment 'videomode'. Two different ways
1491 - "videomode=num" 'num' is a standard LiLo mode numbers.
1492 Following standard modes are supported (* is default):
1494 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1495 -------------+---------------------------------------------
1496 8 bits | 0x301* 0x303 0x305 0x161 0x307
1497 15 bits | 0x310 0x313 0x316 0x162 0x319
1498 16 bits | 0x311 0x314 0x317 0x163 0x31A
1499 24 bits | 0x312 0x315 0x318 ? 0x31B
1500 -------------+---------------------------------------------
1501 (i.e. setenv videomode 317; saveenv; reset;)
1503 - "videomode=bootargs" all the video parameters are parsed
1504 from the bootargs. (See drivers/video/videomodes.c)
1507 CONFIG_VIDEO_SED13806
1508 Enable Epson SED13806 driver. This driver supports 8bpp
1509 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1510 or CONFIG_VIDEO_SED13806_16BPP
1513 Enable the Freescale DIU video driver. Reference boards for
1514 SOCs that have a DIU should define this macro to enable DIU
1515 support, and should also define these other macros:
1521 CONFIG_VIDEO_SW_CURSOR
1522 CONFIG_VGA_AS_SINGLE_DEVICE
1524 CONFIG_VIDEO_BMP_LOGO
1526 The DIU driver will look for the 'video-mode' environment
1527 variable, and if defined, enable the DIU as a console during
1528 boot. See the documentation file README.video for a
1529 description of this variable.
1533 Enable the VGA video / BIOS for x86. The alternative if you
1534 are using coreboot is to use the coreboot frame buffer
1541 Define this to enable a custom keyboard support.
1542 This simply calls drv_keyboard_init() which must be
1543 defined in your board-specific files.
1544 The only board using this so far is RBC823.
1546 - LCD Support: CONFIG_LCD
1548 Define this to enable LCD support (for output to LCD
1549 display); also select one of the supported displays
1550 by defining one of these:
1554 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1556 CONFIG_NEC_NL6448AC33:
1558 NEC NL6448AC33-18. Active, color, single scan.
1560 CONFIG_NEC_NL6448BC20
1562 NEC NL6448BC20-08. 6.5", 640x480.
1563 Active, color, single scan.
1565 CONFIG_NEC_NL6448BC33_54
1567 NEC NL6448BC33-54. 10.4", 640x480.
1568 Active, color, single scan.
1572 Sharp 320x240. Active, color, single scan.
1573 It isn't 16x9, and I am not sure what it is.
1575 CONFIG_SHARP_LQ64D341
1577 Sharp LQ64D341 display, 640x480.
1578 Active, color, single scan.
1582 HLD1045 display, 640x480.
1583 Active, color, single scan.
1587 Optrex CBL50840-2 NF-FW 99 22 M5
1589 Hitachi LMG6912RPFC-00T
1593 320x240. Black & white.
1595 Normally display is black on white background; define
1596 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1598 CONFIG_LCD_ALIGNMENT
1600 Normally the LCD is page-aligned (tyically 4KB). If this is
1601 defined then the LCD will be aligned to this value instead.
1602 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1603 here, since it is cheaper to change data cache settings on
1604 a per-section basis.
1606 CONFIG_CONSOLE_SCROLL_LINES
1608 When the console need to be scrolled, this is the number of
1609 lines to scroll by. It defaults to 1. Increasing this makes
1610 the console jump but can help speed up operation when scrolling
1615 Support drawing of RLE8-compressed bitmaps on the LCD.
1619 Enables an 'i2c edid' command which can read EDID
1620 information over I2C from an attached LCD display.
1622 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1624 If this option is set, the environment is checked for
1625 a variable "splashimage". If found, the usual display
1626 of logo, copyright and system information on the LCD
1627 is suppressed and the BMP image at the address
1628 specified in "splashimage" is loaded instead. The
1629 console is redirected to the "nulldev", too. This
1630 allows for a "silent" boot where a splash screen is
1631 loaded very quickly after power-on.
1633 CONFIG_SPLASHIMAGE_GUARD
1635 If this option is set, then U-Boot will prevent the environment
1636 variable "splashimage" from being set to a problematic address
1637 (see README.displaying-bmps and README.arm-unaligned-accesses).
1638 This option is useful for targets where, due to alignment
1639 restrictions, an improperly aligned BMP image will cause a data
1640 abort. If you think you will not have problems with unaligned
1641 accesses (for example because your toolchain prevents them)
1642 there is no need to set this option.
1644 CONFIG_SPLASH_SCREEN_ALIGN
1646 If this option is set the splash image can be freely positioned
1647 on the screen. Environment variable "splashpos" specifies the
1648 position as "x,y". If a positive number is given it is used as
1649 number of pixel from left/top. If a negative number is given it
1650 is used as number of pixel from right/bottom. You can also
1651 specify 'm' for centering the image.
1654 setenv splashpos m,m
1655 => image at center of screen
1657 setenv splashpos 30,20
1658 => image at x = 30 and y = 20
1660 setenv splashpos -10,m
1661 => vertically centered image
1662 at x = dspWidth - bmpWidth - 9
1664 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1666 If this option is set, additionally to standard BMP
1667 images, gzipped BMP images can be displayed via the
1668 splashscreen support or the bmp command.
1670 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1672 If this option is set, 8-bit RLE compressed BMP images
1673 can be displayed via the splashscreen support or the
1676 - Do compresssing for memory range:
1679 If this option is set, it would use zlib deflate method
1680 to compress the specified memory at its best effort.
1682 - Compression support:
1685 If this option is set, support for bzip2 compressed
1686 images is included. If not, only uncompressed and gzip
1687 compressed images are supported.
1689 NOTE: the bzip2 algorithm requires a lot of RAM, so
1690 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1695 If this option is set, support for lzma compressed
1698 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1699 requires an amount of dynamic memory that is given by the
1702 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1704 Where lc and lp stand for, respectively, Literal context bits
1705 and Literal pos bits.
1707 This value is upper-bounded by 14MB in the worst case. Anyway,
1708 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1709 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1710 a very small buffer.
1712 Use the lzmainfo tool to determinate the lc and lp values and
1713 then calculate the amount of needed dynamic memory (ensuring
1714 the appropriate CONFIG_SYS_MALLOC_LEN value).
1719 The address of PHY on MII bus.
1721 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1723 The clock frequency of the MII bus
1727 If this option is set, support for speed/duplex
1728 detection of gigabit PHY is included.
1730 CONFIG_PHY_RESET_DELAY
1732 Some PHY like Intel LXT971A need extra delay after
1733 reset before any MII register access is possible.
1734 For such PHY, set this option to the usec delay
1735 required. (minimum 300usec for LXT971A)
1737 CONFIG_PHY_CMD_DELAY (ppc4xx)
1739 Some PHY like Intel LXT971A need extra delay after
1740 command issued before MII status register can be read
1750 Define a default value for Ethernet address to use
1751 for the respective Ethernet interface, in case this
1752 is not determined automatically.
1757 Define a default value for the IP address to use for
1758 the default Ethernet interface, in case this is not
1759 determined through e.g. bootp.
1760 (Environment variable "ipaddr")
1762 - Server IP address:
1765 Defines a default value for the IP address of a TFTP
1766 server to contact when using the "tftboot" command.
1767 (Environment variable "serverip")
1769 CONFIG_KEEP_SERVERADDR
1771 Keeps the server's MAC address, in the env 'serveraddr'
1772 for passing to bootargs (like Linux's netconsole option)
1774 - Gateway IP address:
1777 Defines a default value for the IP address of the
1778 default router where packets to other networks are
1780 (Environment variable "gatewayip")
1785 Defines a default value for the subnet mask (or
1786 routing prefix) which is used to determine if an IP
1787 address belongs to the local subnet or needs to be
1788 forwarded through a router.
1789 (Environment variable "netmask")
1791 - Multicast TFTP Mode:
1794 Defines whether you want to support multicast TFTP as per
1795 rfc-2090; for example to work with atftp. Lets lots of targets
1796 tftp down the same boot image concurrently. Note: the Ethernet
1797 driver in use must provide a function: mcast() to join/leave a
1800 - BOOTP Recovery Mode:
1801 CONFIG_BOOTP_RANDOM_DELAY
1803 If you have many targets in a network that try to
1804 boot using BOOTP, you may want to avoid that all
1805 systems send out BOOTP requests at precisely the same
1806 moment (which would happen for instance at recovery
1807 from a power failure, when all systems will try to
1808 boot, thus flooding the BOOTP server. Defining
1809 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1810 inserted before sending out BOOTP requests. The
1811 following delays are inserted then:
1813 1st BOOTP request: delay 0 ... 1 sec
1814 2nd BOOTP request: delay 0 ... 2 sec
1815 3rd BOOTP request: delay 0 ... 4 sec
1817 BOOTP requests: delay 0 ... 8 sec
1819 - DHCP Advanced Options:
1820 You can fine tune the DHCP functionality by defining
1821 CONFIG_BOOTP_* symbols:
1823 CONFIG_BOOTP_SUBNETMASK
1824 CONFIG_BOOTP_GATEWAY
1825 CONFIG_BOOTP_HOSTNAME
1826 CONFIG_BOOTP_NISDOMAIN
1827 CONFIG_BOOTP_BOOTPATH
1828 CONFIG_BOOTP_BOOTFILESIZE
1831 CONFIG_BOOTP_SEND_HOSTNAME
1832 CONFIG_BOOTP_NTPSERVER
1833 CONFIG_BOOTP_TIMEOFFSET
1834 CONFIG_BOOTP_VENDOREX
1835 CONFIG_BOOTP_MAY_FAIL
1837 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1838 environment variable, not the BOOTP server.
1840 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1841 after the configured retry count, the call will fail
1842 instead of starting over. This can be used to fail over
1843 to Link-local IP address configuration if the DHCP server
1846 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1847 serverip from a DHCP server, it is possible that more
1848 than one DNS serverip is offered to the client.
1849 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1850 serverip will be stored in the additional environment
1851 variable "dnsip2". The first DNS serverip is always
1852 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1855 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1856 to do a dynamic update of a DNS server. To do this, they
1857 need the hostname of the DHCP requester.
1858 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1859 of the "hostname" environment variable is passed as
1860 option 12 to the DHCP server.
1862 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1864 A 32bit value in microseconds for a delay between
1865 receiving a "DHCP Offer" and sending the "DHCP Request".
1866 This fixes a problem with certain DHCP servers that don't
1867 respond 100% of the time to a "DHCP request". E.g. On an
1868 AT91RM9200 processor running at 180MHz, this delay needed
1869 to be *at least* 15,000 usec before a Windows Server 2003
1870 DHCP server would reply 100% of the time. I recommend at
1871 least 50,000 usec to be safe. The alternative is to hope
1872 that one of the retries will be successful but note that
1873 the DHCP timeout and retry process takes a longer than
1876 - Link-local IP address negotiation:
1877 Negotiate with other link-local clients on the local network
1878 for an address that doesn't require explicit configuration.
1879 This is especially useful if a DHCP server cannot be guaranteed
1880 to exist in all environments that the device must operate.
1882 See doc/README.link-local for more information.
1885 CONFIG_CDP_DEVICE_ID
1887 The device id used in CDP trigger frames.
1889 CONFIG_CDP_DEVICE_ID_PREFIX
1891 A two character string which is prefixed to the MAC address
1896 A printf format string which contains the ascii name of
1897 the port. Normally is set to "eth%d" which sets
1898 eth0 for the first Ethernet, eth1 for the second etc.
1900 CONFIG_CDP_CAPABILITIES
1902 A 32bit integer which indicates the device capabilities;
1903 0x00000010 for a normal host which does not forwards.
1907 An ascii string containing the version of the software.
1911 An ascii string containing the name of the platform.
1915 A 32bit integer sent on the trigger.
1917 CONFIG_CDP_POWER_CONSUMPTION
1919 A 16bit integer containing the power consumption of the
1920 device in .1 of milliwatts.
1922 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1924 A byte containing the id of the VLAN.
1926 - Status LED: CONFIG_STATUS_LED
1928 Several configurations allow to display the current
1929 status using a LED. For instance, the LED will blink
1930 fast while running U-Boot code, stop blinking as
1931 soon as a reply to a BOOTP request was received, and
1932 start blinking slow once the Linux kernel is running
1933 (supported by a status LED driver in the Linux
1934 kernel). Defining CONFIG_STATUS_LED enables this
1937 - CAN Support: CONFIG_CAN_DRIVER
1939 Defining CONFIG_CAN_DRIVER enables CAN driver support
1940 on those systems that support this (optional)
1941 feature, like the TQM8xxL modules.
1943 - I2C Support: CONFIG_SYS_I2C
1945 This enable the NEW i2c subsystem, and will allow you to use
1946 i2c commands at the u-boot command line (as long as you set
1947 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1948 based realtime clock chips or other i2c devices. See
1949 common/cmd_i2c.c for a description of the command line
1952 ported i2c driver to the new framework:
1953 - drivers/i2c/soft_i2c.c:
1954 - activate first bus with CONFIG_SYS_I2C_SOFT define
1955 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1956 for defining speed and slave address
1957 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1958 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1959 for defining speed and slave address
1960 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1961 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1962 for defining speed and slave address
1963 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1964 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1965 for defining speed and slave address
1967 - drivers/i2c/fsl_i2c.c:
1968 - activate i2c driver with CONFIG_SYS_I2C_FSL
1969 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1970 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1971 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1973 - If your board supports a second fsl i2c bus, define
1974 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1975 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1976 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1979 - drivers/i2c/tegra_i2c.c:
1980 - activate this driver with CONFIG_SYS_I2C_TEGRA
1981 - This driver adds 4 i2c buses with a fix speed from
1982 100000 and the slave addr 0!
1984 - drivers/i2c/ppc4xx_i2c.c
1985 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1986 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1987 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1991 CONFIG_SYS_NUM_I2C_BUSES
1992 Hold the number of i2c busses you want to use. If you
1993 don't use/have i2c muxes on your i2c bus, this
1994 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
1997 CONFIG_SYS_I2C_DIRECT_BUS
1998 define this, if you don't use i2c muxes on your hardware.
1999 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2002 CONFIG_SYS_I2C_MAX_HOPS
2003 define how many muxes are maximal consecutively connected
2004 on one i2c bus. If you not use i2c muxes, omit this
2007 CONFIG_SYS_I2C_BUSES
2008 hold a list of busses you want to use, only used if
2009 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2010 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2011 CONFIG_SYS_NUM_I2C_BUSES = 9:
2013 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2014 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2015 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2016 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2017 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2018 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2019 {1, {I2C_NULL_HOP}}, \
2020 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2021 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2025 bus 0 on adapter 0 without a mux
2026 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2027 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2028 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2029 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2030 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2031 bus 6 on adapter 1 without a mux
2032 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2033 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2035 If you do not have i2c muxes on your board, omit this define.
2037 - Legacy I2C Support: CONFIG_HARD_I2C
2039 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2040 provides the following compelling advantages:
2042 - more than one i2c adapter is usable
2043 - approved multibus support
2044 - better i2c mux support
2046 ** Please consider updating your I2C driver now. **
2048 These enable legacy I2C serial bus commands. Defining
2049 CONFIG_HARD_I2C will include the appropriate I2C driver
2050 for the selected CPU.
2052 This will allow you to use i2c commands at the u-boot
2053 command line (as long as you set CONFIG_CMD_I2C in
2054 CONFIG_COMMANDS) and communicate with i2c based realtime
2055 clock chips. See common/cmd_i2c.c for a description of the
2056 command line interface.
2058 CONFIG_HARD_I2C selects a hardware I2C controller.
2060 There are several other quantities that must also be
2061 defined when you define CONFIG_HARD_I2C.
2063 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2064 to be the frequency (in Hz) at which you wish your i2c bus
2065 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2066 the CPU's i2c node address).
2068 Now, the u-boot i2c code for the mpc8xx
2069 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2070 and so its address should therefore be cleared to 0 (See,
2071 eg, MPC823e User's Manual p.16-473). So, set
2072 CONFIG_SYS_I2C_SLAVE to 0.
2074 CONFIG_SYS_I2C_INIT_MPC5XXX
2076 When a board is reset during an i2c bus transfer
2077 chips might think that the current transfer is still
2078 in progress. Reset the slave devices by sending start
2079 commands until the slave device responds.
2081 That's all that's required for CONFIG_HARD_I2C.
2083 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2084 then the following macros need to be defined (examples are
2085 from include/configs/lwmon.h):
2089 (Optional). Any commands necessary to enable the I2C
2090 controller or configure ports.
2092 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2096 (Only for MPC8260 CPU). The I/O port to use (the code
2097 assumes both bits are on the same port). Valid values
2098 are 0..3 for ports A..D.
2102 The code necessary to make the I2C data line active
2103 (driven). If the data line is open collector, this
2106 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2110 The code necessary to make the I2C data line tri-stated
2111 (inactive). If the data line is open collector, this
2114 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2118 Code that returns true if the I2C data line is high,
2121 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2125 If <bit> is true, sets the I2C data line high. If it
2126 is false, it clears it (low).
2128 eg: #define I2C_SDA(bit) \
2129 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2130 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2134 If <bit> is true, sets the I2C clock line high. If it
2135 is false, it clears it (low).
2137 eg: #define I2C_SCL(bit) \
2138 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2139 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2143 This delay is invoked four times per clock cycle so this
2144 controls the rate of data transfer. The data rate thus
2145 is 1 / (I2C_DELAY * 4). Often defined to be something
2148 #define I2C_DELAY udelay(2)
2150 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2152 If your arch supports the generic GPIO framework (asm/gpio.h),
2153 then you may alternatively define the two GPIOs that are to be
2154 used as SCL / SDA. Any of the previous I2C_xxx macros will
2155 have GPIO-based defaults assigned to them as appropriate.
2157 You should define these to the GPIO value as given directly to
2158 the generic GPIO functions.
2160 CONFIG_SYS_I2C_INIT_BOARD
2162 When a board is reset during an i2c bus transfer
2163 chips might think that the current transfer is still
2164 in progress. On some boards it is possible to access
2165 the i2c SCLK line directly, either by using the
2166 processor pin as a GPIO or by having a second pin
2167 connected to the bus. If this option is defined a
2168 custom i2c_init_board() routine in boards/xxx/board.c
2169 is run early in the boot sequence.
2171 CONFIG_SYS_I2C_BOARD_LATE_INIT
2173 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2174 defined a custom i2c_board_late_init() routine in
2175 boards/xxx/board.c is run AFTER the operations in i2c_init()
2176 is completed. This callpoint can be used to unreset i2c bus
2177 using CPU i2c controller register accesses for CPUs whose i2c
2178 controller provide such a method. It is called at the end of
2179 i2c_init() to allow i2c_init operations to setup the i2c bus
2180 controller on the CPU (e.g. setting bus speed & slave address).
2182 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2184 This option enables configuration of bi_iic_fast[] flags
2185 in u-boot bd_info structure based on u-boot environment
2186 variable "i2cfast". (see also i2cfast)
2188 CONFIG_I2C_MULTI_BUS
2190 This option allows the use of multiple I2C buses, each of which
2191 must have a controller. At any point in time, only one bus is
2192 active. To switch to a different bus, use the 'i2c dev' command.
2193 Note that bus numbering is zero-based.
2195 CONFIG_SYS_I2C_NOPROBES
2197 This option specifies a list of I2C devices that will be skipped
2198 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2199 is set, specify a list of bus-device pairs. Otherwise, specify
2200 a 1D array of device addresses
2203 #undef CONFIG_I2C_MULTI_BUS
2204 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2206 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2208 #define CONFIG_I2C_MULTI_BUS
2209 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2211 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2213 CONFIG_SYS_SPD_BUS_NUM
2215 If defined, then this indicates the I2C bus number for DDR SPD.
2216 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2218 CONFIG_SYS_RTC_BUS_NUM
2220 If defined, then this indicates the I2C bus number for the RTC.
2221 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2223 CONFIG_SYS_DTT_BUS_NUM
2225 If defined, then this indicates the I2C bus number for the DTT.
2226 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2228 CONFIG_SYS_I2C_DTT_ADDR:
2230 If defined, specifies the I2C address of the DTT device.
2231 If not defined, then U-Boot uses predefined value for
2232 specified DTT device.
2234 CONFIG_SOFT_I2C_READ_REPEATED_START
2236 defining this will force the i2c_read() function in
2237 the soft_i2c driver to perform an I2C repeated start
2238 between writing the address pointer and reading the
2239 data. If this define is omitted the default behaviour
2240 of doing a stop-start sequence will be used. Most I2C
2241 devices can use either method, but some require one or
2244 - SPI Support: CONFIG_SPI
2246 Enables SPI driver (so far only tested with
2247 SPI EEPROM, also an instance works with Crystal A/D and
2248 D/As on the SACSng board)
2252 Enables the driver for SPI controller on SuperH. Currently
2253 only SH7757 is supported.
2257 Enables extended (16-bit) SPI EEPROM addressing.
2258 (symmetrical to CONFIG_I2C_X)
2262 Enables a software (bit-bang) SPI driver rather than
2263 using hardware support. This is a general purpose
2264 driver that only requires three general I/O port pins
2265 (two outputs, one input) to function. If this is
2266 defined, the board configuration must define several
2267 SPI configuration items (port pins to use, etc). For
2268 an example, see include/configs/sacsng.h.
2272 Enables a hardware SPI driver for general-purpose reads
2273 and writes. As with CONFIG_SOFT_SPI, the board configuration
2274 must define a list of chip-select function pointers.
2275 Currently supported on some MPC8xxx processors. For an
2276 example, see include/configs/mpc8349emds.h.
2280 Enables the driver for the SPI controllers on i.MX and MXC
2281 SoCs. Currently i.MX31/35/51 are supported.
2283 - FPGA Support: CONFIG_FPGA
2285 Enables FPGA subsystem.
2287 CONFIG_FPGA_<vendor>
2289 Enables support for specific chip vendors.
2292 CONFIG_FPGA_<family>
2294 Enables support for FPGA family.
2295 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2299 Specify the number of FPGA devices to support.
2301 CONFIG_SYS_FPGA_PROG_FEEDBACK
2303 Enable printing of hash marks during FPGA configuration.
2305 CONFIG_SYS_FPGA_CHECK_BUSY
2307 Enable checks on FPGA configuration interface busy
2308 status by the configuration function. This option
2309 will require a board or device specific function to
2314 If defined, a function that provides delays in the FPGA
2315 configuration driver.
2317 CONFIG_SYS_FPGA_CHECK_CTRLC
2318 Allow Control-C to interrupt FPGA configuration
2320 CONFIG_SYS_FPGA_CHECK_ERROR
2322 Check for configuration errors during FPGA bitfile
2323 loading. For example, abort during Virtex II
2324 configuration if the INIT_B line goes low (which
2325 indicated a CRC error).
2327 CONFIG_SYS_FPGA_WAIT_INIT
2329 Maximum time to wait for the INIT_B line to deassert
2330 after PROB_B has been deasserted during a Virtex II
2331 FPGA configuration sequence. The default time is 500
2334 CONFIG_SYS_FPGA_WAIT_BUSY
2336 Maximum time to wait for BUSY to deassert during
2337 Virtex II FPGA configuration. The default is 5 ms.
2339 CONFIG_SYS_FPGA_WAIT_CONFIG
2341 Time to wait after FPGA configuration. The default is
2344 - Configuration Management:
2347 If defined, this string will be added to the U-Boot
2348 version information (U_BOOT_VERSION)
2350 - Vendor Parameter Protection:
2352 U-Boot considers the values of the environment
2353 variables "serial#" (Board Serial Number) and
2354 "ethaddr" (Ethernet Address) to be parameters that
2355 are set once by the board vendor / manufacturer, and
2356 protects these variables from casual modification by
2357 the user. Once set, these variables are read-only,
2358 and write or delete attempts are rejected. You can
2359 change this behaviour:
2361 If CONFIG_ENV_OVERWRITE is #defined in your config
2362 file, the write protection for vendor parameters is
2363 completely disabled. Anybody can change or delete
2366 Alternatively, if you #define _both_ CONFIG_ETHADDR
2367 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2368 Ethernet address is installed in the environment,
2369 which can be changed exactly ONCE by the user. [The
2370 serial# is unaffected by this, i. e. it remains
2373 The same can be accomplished in a more flexible way
2374 for any variable by configuring the type of access
2375 to allow for those variables in the ".flags" variable
2376 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2381 Define this variable to enable the reservation of
2382 "protected RAM", i. e. RAM which is not overwritten
2383 by U-Boot. Define CONFIG_PRAM to hold the number of
2384 kB you want to reserve for pRAM. You can overwrite
2385 this default value by defining an environment
2386 variable "pram" to the number of kB you want to
2387 reserve. Note that the board info structure will
2388 still show the full amount of RAM. If pRAM is
2389 reserved, a new environment variable "mem" will
2390 automatically be defined to hold the amount of
2391 remaining RAM in a form that can be passed as boot
2392 argument to Linux, for instance like that:
2394 setenv bootargs ... mem=\${mem}
2397 This way you can tell Linux not to use this memory,
2398 either, which results in a memory region that will
2399 not be affected by reboots.
2401 *WARNING* If your board configuration uses automatic
2402 detection of the RAM size, you must make sure that
2403 this memory test is non-destructive. So far, the
2404 following board configurations are known to be
2407 IVMS8, IVML24, SPD8xx, TQM8xxL,
2408 HERMES, IP860, RPXlite, LWMON,
2411 - Access to physical memory region (> 4GB)
2412 Some basic support is provided for operations on memory not
2413 normally accessible to U-Boot - e.g. some architectures
2414 support access to more than 4GB of memory on 32-bit
2415 machines using physical address extension or similar.
2416 Define CONFIG_PHYSMEM to access this basic support, which
2417 currently only supports clearing the memory.
2422 Define this variable to stop the system in case of a
2423 fatal error, so that you have to reset it manually.
2424 This is probably NOT a good idea for an embedded
2425 system where you want the system to reboot
2426 automatically as fast as possible, but it may be
2427 useful during development since you can try to debug
2428 the conditions that lead to the situation.
2430 CONFIG_NET_RETRY_COUNT
2432 This variable defines the number of retries for
2433 network operations like ARP, RARP, TFTP, or BOOTP
2434 before giving up the operation. If not defined, a
2435 default value of 5 is used.
2439 Timeout waiting for an ARP reply in milliseconds.
2443 Timeout in milliseconds used in NFS protocol.
2444 If you encounter "ERROR: Cannot umount" in nfs command,
2445 try longer timeout such as
2446 #define CONFIG_NFS_TIMEOUT 10000UL
2448 - Command Interpreter:
2449 CONFIG_AUTO_COMPLETE
2451 Enable auto completion of commands using TAB.
2453 Note that this feature has NOT been implemented yet
2454 for the "hush" shell.
2457 CONFIG_SYS_HUSH_PARSER
2459 Define this variable to enable the "hush" shell (from
2460 Busybox) as command line interpreter, thus enabling
2461 powerful command line syntax like
2462 if...then...else...fi conditionals or `&&' and '||'
2463 constructs ("shell scripts").
2465 If undefined, you get the old, much simpler behaviour
2466 with a somewhat smaller memory footprint.
2469 CONFIG_SYS_PROMPT_HUSH_PS2
2471 This defines the secondary prompt string, which is
2472 printed when the command interpreter needs more input
2473 to complete a command. Usually "> ".
2477 In the current implementation, the local variables
2478 space and global environment variables space are
2479 separated. Local variables are those you define by
2480 simply typing `name=value'. To access a local
2481 variable later on, you have write `$name' or
2482 `${name}'; to execute the contents of a variable
2483 directly type `$name' at the command prompt.
2485 Global environment variables are those you use
2486 setenv/printenv to work with. To run a command stored
2487 in such a variable, you need to use the run command,
2488 and you must not use the '$' sign to access them.
2490 To store commands and special characters in a
2491 variable, please use double quotation marks
2492 surrounding the whole text of the variable, instead
2493 of the backslashes before semicolons and special
2496 - Commandline Editing and History:
2497 CONFIG_CMDLINE_EDITING
2499 Enable editing and History functions for interactive
2500 commandline input operations
2502 - Default Environment:
2503 CONFIG_EXTRA_ENV_SETTINGS
2505 Define this to contain any number of null terminated
2506 strings (variable = value pairs) that will be part of
2507 the default environment compiled into the boot image.
2509 For example, place something like this in your
2510 board's config file:
2512 #define CONFIG_EXTRA_ENV_SETTINGS \
2516 Warning: This method is based on knowledge about the
2517 internal format how the environment is stored by the
2518 U-Boot code. This is NOT an official, exported
2519 interface! Although it is unlikely that this format
2520 will change soon, there is no guarantee either.
2521 You better know what you are doing here.
2523 Note: overly (ab)use of the default environment is
2524 discouraged. Make sure to check other ways to preset
2525 the environment like the "source" command or the
2528 CONFIG_ENV_VARS_UBOOT_CONFIG
2530 Define this in order to add variables describing the
2531 U-Boot build configuration to the default environment.
2532 These will be named arch, cpu, board, vendor, and soc.
2534 Enabling this option will cause the following to be defined:
2542 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2544 Define this in order to add variables describing certain
2545 run-time determined information about the hardware to the
2546 environment. These will be named board_name, board_rev.
2548 CONFIG_DELAY_ENVIRONMENT
2550 Normally the environment is loaded when the board is
2551 intialised so that it is available to U-Boot. This inhibits
2552 that so that the environment is not available until
2553 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2554 this is instead controlled by the value of
2555 /config/load-environment.
2557 - DataFlash Support:
2558 CONFIG_HAS_DATAFLASH
2560 Defining this option enables DataFlash features and
2561 allows to read/write in Dataflash via the standard
2564 - Serial Flash support
2567 Defining this option enables SPI flash commands
2568 'sf probe/read/write/erase/update'.
2570 Usage requires an initial 'probe' to define the serial
2571 flash parameters, followed by read/write/erase/update
2574 The following defaults may be provided by the platform
2575 to handle the common case when only a single serial
2576 flash is present on the system.
2578 CONFIG_SF_DEFAULT_BUS Bus identifier
2579 CONFIG_SF_DEFAULT_CS Chip-select
2580 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2581 CONFIG_SF_DEFAULT_SPEED in Hz
2585 Define this option to include a destructive SPI flash
2588 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2590 Define this option to use the Bank addr/Extended addr
2591 support on SPI flashes which has size > 16Mbytes.
2593 - SystemACE Support:
2596 Adding this option adds support for Xilinx SystemACE
2597 chips attached via some sort of local bus. The address
2598 of the chip must also be defined in the
2599 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2601 #define CONFIG_SYSTEMACE
2602 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2604 When SystemACE support is added, the "ace" device type
2605 becomes available to the fat commands, i.e. fatls.
2607 - TFTP Fixed UDP Port:
2610 If this is defined, the environment variable tftpsrcp
2611 is used to supply the TFTP UDP source port value.
2612 If tftpsrcp isn't defined, the normal pseudo-random port
2613 number generator is used.
2615 Also, the environment variable tftpdstp is used to supply
2616 the TFTP UDP destination port value. If tftpdstp isn't
2617 defined, the normal port 69 is used.
2619 The purpose for tftpsrcp is to allow a TFTP server to
2620 blindly start the TFTP transfer using the pre-configured
2621 target IP address and UDP port. This has the effect of
2622 "punching through" the (Windows XP) firewall, allowing
2623 the remainder of the TFTP transfer to proceed normally.
2624 A better solution is to properly configure the firewall,
2625 but sometimes that is not allowed.
2630 This enables a generic 'hash' command which can produce
2631 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2635 Enable the hash verify command (hash -v). This adds to code
2638 CONFIG_SHA1 - support SHA1 hashing
2639 CONFIG_SHA256 - support SHA256 hashing
2641 Note: There is also a sha1sum command, which should perhaps
2642 be deprecated in favour of 'hash sha1'.
2644 - Freescale i.MX specific commands:
2645 CONFIG_CMD_HDMIDETECT
2646 This enables 'hdmidet' command which returns true if an
2647 HDMI monitor is detected. This command is i.MX 6 specific.
2650 This enables the 'bmode' (bootmode) command for forcing
2651 a boot from specific media.
2653 This is useful for forcing the ROM's usb downloader to
2654 activate upon a watchdog reset which is nice when iterating
2655 on U-Boot. Using the reset button or running bmode normal
2656 will set it back to normal. This command currently
2657 supports i.MX53 and i.MX6.
2662 This enables the RSA algorithm used for FIT image verification
2663 in U-Boot. See doc/uImage/signature for more information.
2665 The signing part is build into mkimage regardless of this
2669 - Show boot progress:
2670 CONFIG_SHOW_BOOT_PROGRESS
2672 Defining this option allows to add some board-
2673 specific code (calling a user-provided function
2674 "show_boot_progress(int)") that enables you to show
2675 the system's boot progress on some display (for
2676 example, some LED's) on your board. At the moment,
2677 the following checkpoints are implemented:
2679 - Detailed boot stage timing
2681 Define this option to get detailed timing of each stage
2682 of the boot process.
2684 CONFIG_BOOTSTAGE_USER_COUNT
2685 This is the number of available user bootstage records.
2686 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2687 a new ID will be allocated from this stash. If you exceed
2688 the limit, recording will stop.
2690 CONFIG_BOOTSTAGE_REPORT
2691 Define this to print a report before boot, similar to this:
2693 Timer summary in microseconds:
2696 3,575,678 3,575,678 board_init_f start
2697 3,575,695 17 arch_cpu_init A9
2698 3,575,777 82 arch_cpu_init done
2699 3,659,598 83,821 board_init_r start
2700 3,910,375 250,777 main_loop
2701 29,916,167 26,005,792 bootm_start
2702 30,361,327 445,160 start_kernel
2704 CONFIG_CMD_BOOTSTAGE
2705 Add a 'bootstage' command which supports printing a report
2706 and un/stashing of bootstage data.
2708 CONFIG_BOOTSTAGE_FDT
2709 Stash the bootstage information in the FDT. A root 'bootstage'
2710 node is created with each bootstage id as a child. Each child
2711 has a 'name' property and either 'mark' containing the
2712 mark time in microsecond, or 'accum' containing the
2713 accumulated time for that bootstage id in microseconds.
2718 name = "board_init_f";
2727 Code in the Linux kernel can find this in /proc/devicetree.
2729 Legacy uImage format:
2732 1 common/cmd_bootm.c before attempting to boot an image
2733 -1 common/cmd_bootm.c Image header has bad magic number
2734 2 common/cmd_bootm.c Image header has correct magic number
2735 -2 common/cmd_bootm.c Image header has bad checksum
2736 3 common/cmd_bootm.c Image header has correct checksum
2737 -3 common/cmd_bootm.c Image data has bad checksum
2738 4 common/cmd_bootm.c Image data has correct checksum
2739 -4 common/cmd_bootm.c Image is for unsupported architecture
2740 5 common/cmd_bootm.c Architecture check OK
2741 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2742 6 common/cmd_bootm.c Image Type check OK
2743 -6 common/cmd_bootm.c gunzip uncompression error
2744 -7 common/cmd_bootm.c Unimplemented compression type
2745 7 common/cmd_bootm.c Uncompression OK
2746 8 common/cmd_bootm.c No uncompress/copy overwrite error
2747 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2749 9 common/image.c Start initial ramdisk verification
2750 -10 common/image.c Ramdisk header has bad magic number
2751 -11 common/image.c Ramdisk header has bad checksum
2752 10 common/image.c Ramdisk header is OK
2753 -12 common/image.c Ramdisk data has bad checksum
2754 11 common/image.c Ramdisk data has correct checksum
2755 12 common/image.c Ramdisk verification complete, start loading
2756 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2757 13 common/image.c Start multifile image verification
2758 14 common/image.c No initial ramdisk, no multifile, continue.
2760 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2762 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2763 -31 post/post.c POST test failed, detected by post_output_backlog()
2764 -32 post/post.c POST test failed, detected by post_run_single()
2766 34 common/cmd_doc.c before loading a Image from a DOC device
2767 -35 common/cmd_doc.c Bad usage of "doc" command
2768 35 common/cmd_doc.c correct usage of "doc" command
2769 -36 common/cmd_doc.c No boot device
2770 36 common/cmd_doc.c correct boot device
2771 -37 common/cmd_doc.c Unknown Chip ID on boot device
2772 37 common/cmd_doc.c correct chip ID found, device available
2773 -38 common/cmd_doc.c Read Error on boot device
2774 38 common/cmd_doc.c reading Image header from DOC device OK
2775 -39 common/cmd_doc.c Image header has bad magic number
2776 39 common/cmd_doc.c Image header has correct magic number
2777 -40 common/cmd_doc.c Error reading Image from DOC device
2778 40 common/cmd_doc.c Image header has correct magic number
2779 41 common/cmd_ide.c before loading a Image from a IDE device
2780 -42 common/cmd_ide.c Bad usage of "ide" command
2781 42 common/cmd_ide.c correct usage of "ide" command
2782 -43 common/cmd_ide.c No boot device
2783 43 common/cmd_ide.c boot device found
2784 -44 common/cmd_ide.c Device not available
2785 44 common/cmd_ide.c Device available
2786 -45 common/cmd_ide.c wrong partition selected
2787 45 common/cmd_ide.c partition selected
2788 -46 common/cmd_ide.c Unknown partition table
2789 46 common/cmd_ide.c valid partition table found
2790 -47 common/cmd_ide.c Invalid partition type
2791 47 common/cmd_ide.c correct partition type
2792 -48 common/cmd_ide.c Error reading Image Header on boot device
2793 48 common/cmd_ide.c reading Image Header from IDE device OK
2794 -49 common/cmd_ide.c Image header has bad magic number
2795 49 common/cmd_ide.c Image header has correct magic number
2796 -50 common/cmd_ide.c Image header has bad checksum
2797 50 common/cmd_ide.c Image header has correct checksum
2798 -51 common/cmd_ide.c Error reading Image from IDE device
2799 51 common/cmd_ide.c reading Image from IDE device OK
2800 52 common/cmd_nand.c before loading a Image from a NAND device
2801 -53 common/cmd_nand.c Bad usage of "nand" command
2802 53 common/cmd_nand.c correct usage of "nand" command
2803 -54 common/cmd_nand.c No boot device
2804 54 common/cmd_nand.c boot device found
2805 -55 common/cmd_nand.c Unknown Chip ID on boot device
2806 55 common/cmd_nand.c correct chip ID found, device available
2807 -56 common/cmd_nand.c Error reading Image Header on boot device
2808 56 common/cmd_nand.c reading Image Header from NAND device OK
2809 -57 common/cmd_nand.c Image header has bad magic number
2810 57 common/cmd_nand.c Image header has correct magic number
2811 -58 common/cmd_nand.c Error reading Image from NAND device
2812 58 common/cmd_nand.c reading Image from NAND device OK
2814 -60 common/env_common.c Environment has a bad CRC, using default
2816 64 net/eth.c starting with Ethernet configuration.
2817 -64 net/eth.c no Ethernet found.
2818 65 net/eth.c Ethernet found.
2820 -80 common/cmd_net.c usage wrong
2821 80 common/cmd_net.c before calling NetLoop()
2822 -81 common/cmd_net.c some error in NetLoop() occurred
2823 81 common/cmd_net.c NetLoop() back without error
2824 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2825 82 common/cmd_net.c trying automatic boot
2826 83 common/cmd_net.c running "source" command
2827 -83 common/cmd_net.c some error in automatic boot or "source" command
2828 84 common/cmd_net.c end without errors
2833 100 common/cmd_bootm.c Kernel FIT Image has correct format
2834 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2835 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2836 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2837 102 common/cmd_bootm.c Kernel unit name specified
2838 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2839 103 common/cmd_bootm.c Found configuration node
2840 104 common/cmd_bootm.c Got kernel subimage node offset
2841 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2842 105 common/cmd_bootm.c Kernel subimage hash verification OK
2843 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2844 106 common/cmd_bootm.c Architecture check OK
2845 -106 common/cmd_bootm.c Kernel subimage has wrong type
2846 107 common/cmd_bootm.c Kernel subimage type OK
2847 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2848 108 common/cmd_bootm.c Got kernel subimage data/size
2849 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2850 -109 common/cmd_bootm.c Can't get kernel subimage type
2851 -110 common/cmd_bootm.c Can't get kernel subimage comp
2852 -111 common/cmd_bootm.c Can't get kernel subimage os
2853 -112 common/cmd_bootm.c Can't get kernel subimage load address
2854 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2856 120 common/image.c Start initial ramdisk verification
2857 -120 common/image.c Ramdisk FIT image has incorrect format
2858 121 common/image.c Ramdisk FIT image has correct format
2859 122 common/image.c No ramdisk subimage unit name, using configuration
2860 -122 common/image.c Can't get configuration for ramdisk subimage
2861 123 common/image.c Ramdisk unit name specified
2862 -124 common/image.c Can't get ramdisk subimage node offset
2863 125 common/image.c Got ramdisk subimage node offset
2864 -125 common/image.c Ramdisk subimage hash verification failed
2865 126 common/image.c Ramdisk subimage hash verification OK
2866 -126 common/image.c Ramdisk subimage for unsupported architecture
2867 127 common/image.c Architecture check OK
2868 -127 common/image.c Can't get ramdisk subimage data/size
2869 128 common/image.c Got ramdisk subimage data/size
2870 129 common/image.c Can't get ramdisk load address
2871 -129 common/image.c Got ramdisk load address
2873 -130 common/cmd_doc.c Incorrect FIT image format
2874 131 common/cmd_doc.c FIT image format OK
2876 -140 common/cmd_ide.c Incorrect FIT image format
2877 141 common/cmd_ide.c FIT image format OK
2879 -150 common/cmd_nand.c Incorrect FIT image format
2880 151 common/cmd_nand.c FIT image format OK
2882 - FIT image support:
2884 Enable support for the FIT uImage format.
2886 CONFIG_FIT_BEST_MATCH
2887 When no configuration is explicitly selected, default to the
2888 one whose fdt's compatibility field best matches that of
2889 U-Boot itself. A match is considered "best" if it matches the
2890 most specific compatibility entry of U-Boot's fdt's root node.
2891 The order of entries in the configuration's fdt is ignored.
2893 CONFIG_FIT_SIGNATURE
2894 This option enables signature verification of FIT uImages,
2895 using a hash signed and verified using RSA. See
2896 doc/uImage.FIT/signature.txt for more details.
2898 - Standalone program support:
2899 CONFIG_STANDALONE_LOAD_ADDR
2901 This option defines a board specific value for the
2902 address where standalone program gets loaded, thus
2903 overwriting the architecture dependent default
2906 - Frame Buffer Address:
2909 Define CONFIG_FB_ADDR if you want to use specific
2910 address for frame buffer. This is typically the case
2911 when using a graphics controller has separate video
2912 memory. U-Boot will then place the frame buffer at
2913 the given address instead of dynamically reserving it
2914 in system RAM by calling lcd_setmem(), which grabs
2915 the memory for the frame buffer depending on the
2916 configured panel size.
2918 Please see board_init_f function.
2920 - Automatic software updates via TFTP server
2922 CONFIG_UPDATE_TFTP_CNT_MAX
2923 CONFIG_UPDATE_TFTP_MSEC_MAX
2925 These options enable and control the auto-update feature;
2926 for a more detailed description refer to doc/README.update.
2928 - MTD Support (mtdparts command, UBI support)
2931 Adds the MTD device infrastructure from the Linux kernel.
2932 Needed for mtdparts command support.
2934 CONFIG_MTD_PARTITIONS
2936 Adds the MTD partitioning infrastructure from the Linux
2937 kernel. Needed for UBI support.
2942 Adds commands for interacting with MTD partitions formatted
2943 with the UBI flash translation layer
2945 Requires also defining CONFIG_RBTREE
2947 CONFIG_UBI_SILENCE_MSG
2949 Make the verbose messages from UBI stop printing. This leaves
2950 warnings and errors enabled.
2955 Adds commands for interacting with UBI volumes formatted as
2956 UBIFS. UBIFS is read-only in u-boot.
2958 Requires UBI support as well as CONFIG_LZO
2960 CONFIG_UBIFS_SILENCE_MSG
2962 Make the verbose messages from UBIFS stop printing. This leaves
2963 warnings and errors enabled.
2967 Enable building of SPL globally.
2970 LDSCRIPT for linking the SPL binary.
2972 CONFIG_SPL_MAX_FOOTPRINT
2973 Maximum size in memory allocated to the SPL, BSS included.
2974 When defined, the linker checks that the actual memory
2975 used by SPL from _start to __bss_end does not exceed it.
2976 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2977 must not be both defined at the same time.
2980 Maximum size of the SPL image (text, data, rodata, and
2981 linker lists sections), BSS excluded.
2982 When defined, the linker checks that the actual size does
2985 CONFIG_SPL_TEXT_BASE
2986 TEXT_BASE for linking the SPL binary.
2988 CONFIG_SPL_RELOC_TEXT_BASE
2989 Address to relocate to. If unspecified, this is equal to
2990 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2992 CONFIG_SPL_BSS_START_ADDR
2993 Link address for the BSS within the SPL binary.
2995 CONFIG_SPL_BSS_MAX_SIZE
2996 Maximum size in memory allocated to the SPL BSS.
2997 When defined, the linker checks that the actual memory used
2998 by SPL from __bss_start to __bss_end does not exceed it.
2999 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3000 must not be both defined at the same time.
3003 Adress of the start of the stack SPL will use
3005 CONFIG_SPL_RELOC_STACK
3006 Adress of the start of the stack SPL will use after
3007 relocation. If unspecified, this is equal to
3010 CONFIG_SYS_SPL_MALLOC_START
3011 Starting address of the malloc pool used in SPL.
3013 CONFIG_SYS_SPL_MALLOC_SIZE
3014 The size of the malloc pool used in SPL.
3016 CONFIG_SPL_FRAMEWORK
3017 Enable the SPL framework under common/. This framework
3018 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3019 NAND loading of the Linux Kernel.
3021 CONFIG_SPL_DISPLAY_PRINT
3022 For ARM, enable an optional function to print more information
3023 about the running system.
3025 CONFIG_SPL_INIT_MINIMAL
3026 Arch init code should be built for a very small image
3028 CONFIG_SPL_LIBCOMMON_SUPPORT
3029 Support for common/libcommon.o in SPL binary
3031 CONFIG_SPL_LIBDISK_SUPPORT
3032 Support for disk/libdisk.o in SPL binary
3034 CONFIG_SPL_I2C_SUPPORT
3035 Support for drivers/i2c/libi2c.o in SPL binary
3037 CONFIG_SPL_GPIO_SUPPORT
3038 Support for drivers/gpio/libgpio.o in SPL binary
3040 CONFIG_SPL_MMC_SUPPORT
3041 Support for drivers/mmc/libmmc.o in SPL binary
3043 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3044 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3045 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3046 Address, size and partition on the MMC to load U-Boot from
3047 when the MMC is being used in raw mode.
3049 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3050 Sector to load kernel uImage from when MMC is being
3051 used in raw mode (for Falcon mode)
3053 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3054 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3055 Sector and number of sectors to load kernel argument
3056 parameters from when MMC is being used in raw mode
3059 CONFIG_SPL_FAT_SUPPORT
3060 Support for fs/fat/libfat.o in SPL binary
3062 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3063 Filename to read to load U-Boot when reading from FAT
3065 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3066 Filename to read to load kernel uImage when reading
3067 from FAT (for Falcon mode)
3069 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3070 Filename to read to load kernel argument parameters
3071 when reading from FAT (for Falcon mode)
3073 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3074 Set this for NAND SPL on PPC mpc83xx targets, so that
3075 start.S waits for the rest of the SPL to load before
3076 continuing (the hardware starts execution after just
3077 loading the first page rather than the full 4K).
3079 CONFIG_SPL_NAND_BASE
3080 Include nand_base.c in the SPL. Requires
3081 CONFIG_SPL_NAND_DRIVERS.
3083 CONFIG_SPL_NAND_DRIVERS
3084 SPL uses normal NAND drivers, not minimal drivers.
3087 Include standard software ECC in the SPL
3089 CONFIG_SPL_NAND_SIMPLE
3090 Support for NAND boot using simple NAND drivers that
3091 expose the cmd_ctrl() interface.
3093 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3094 Set for the SPL on PPC mpc8xxx targets, support for
3095 arch/powerpc/cpu/mpc8xxx/ddr/libddr.o in SPL binary.
3097 CONFIG_SPL_COMMON_INIT_DDR
3098 Set for common ddr init with serial presence detect in
3101 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3102 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3103 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3104 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3105 CONFIG_SYS_NAND_ECCBYTES
3106 Defines the size and behavior of the NAND that SPL uses
3109 CONFIG_SYS_NAND_U_BOOT_OFFS
3110 Location in NAND to read U-Boot from
3112 CONFIG_SYS_NAND_U_BOOT_DST
3113 Location in memory to load U-Boot to
3115 CONFIG_SYS_NAND_U_BOOT_SIZE
3116 Size of image to load
3118 CONFIG_SYS_NAND_U_BOOT_START
3119 Entry point in loaded image to jump to
3121 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3122 Define this if you need to first read the OOB and then the
3123 data. This is used for example on davinci plattforms.
3125 CONFIG_SPL_OMAP3_ID_NAND
3126 Support for an OMAP3-specific set of functions to return the
3127 ID and MFR of the first attached NAND chip, if present.
3129 CONFIG_SPL_SERIAL_SUPPORT
3130 Support for drivers/serial/libserial.o in SPL binary
3132 CONFIG_SPL_SPI_FLASH_SUPPORT
3133 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3135 CONFIG_SPL_SPI_SUPPORT
3136 Support for drivers/spi/libspi.o in SPL binary
3138 CONFIG_SPL_RAM_DEVICE
3139 Support for running image already present in ram, in SPL binary
3141 CONFIG_SPL_LIBGENERIC_SUPPORT
3142 Support for lib/libgeneric.o in SPL binary
3144 CONFIG_SPL_ENV_SUPPORT
3145 Support for the environment operating in SPL binary
3147 CONFIG_SPL_NET_SUPPORT
3148 Support for the net/libnet.o in SPL binary.
3149 It conflicts with SPL env from storage medium specified by
3150 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3153 Image offset to which the SPL should be padded before appending
3154 the SPL payload. By default, this is defined as
3155 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3156 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3157 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3160 Final target image containing SPL and payload. Some SPLs
3161 use an arch-specific makefile fragment instead, for
3162 example if more than one image needs to be produced.
3164 CONFIG_FIT_SPL_PRINT
3165 Printing information about a FIT image adds quite a bit of
3166 code to SPL. So this is normally disabled in SPL. Use this
3167 option to re-enable it. This will affect the output of the
3168 bootm command when booting a FIT image.
3173 [so far only for SMDK2400 boards]
3175 - Modem support enable:
3176 CONFIG_MODEM_SUPPORT
3178 - RTS/CTS Flow control enable:
3181 - Modem debug support:
3182 CONFIG_MODEM_SUPPORT_DEBUG
3184 Enables debugging stuff (char screen[1024], dbg())
3185 for modem support. Useful only with BDI2000.
3187 - Interrupt support (PPC):
3189 There are common interrupt_init() and timer_interrupt()
3190 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3191 for CPU specific initialization. interrupt_init_cpu()
3192 should set decrementer_count to appropriate value. If
3193 CPU resets decrementer automatically after interrupt
3194 (ppc4xx) it should set decrementer_count to zero.
3195 timer_interrupt() calls timer_interrupt_cpu() for CPU
3196 specific handling. If board has watchdog / status_led
3197 / other_activity_monitor it works automatically from
3198 general timer_interrupt().
3202 In the target system modem support is enabled when a
3203 specific key (key combination) is pressed during
3204 power-on. Otherwise U-Boot will boot normally
3205 (autoboot). The key_pressed() function is called from
3206 board_init(). Currently key_pressed() is a dummy
3207 function, returning 1 and thus enabling modem
3210 If there are no modem init strings in the
3211 environment, U-Boot proceed to autoboot; the
3212 previous output (banner, info printfs) will be
3215 See also: doc/README.Modem
3217 Board initialization settings:
3218 ------------------------------
3220 During Initialization u-boot calls a number of board specific functions
3221 to allow the preparation of board specific prerequisites, e.g. pin setup
3222 before drivers are initialized. To enable these callbacks the
3223 following configuration macros have to be defined. Currently this is
3224 architecture specific, so please check arch/your_architecture/lib/board.c
3225 typically in board_init_f() and board_init_r().
3227 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3228 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3229 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3230 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3232 Configuration Settings:
3233 -----------------------
3235 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3236 undefine this when you're short of memory.
3238 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3239 width of the commands listed in the 'help' command output.
3241 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3242 prompt for user input.
3244 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3246 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3248 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3250 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3251 the application (usually a Linux kernel) when it is
3254 - CONFIG_SYS_BAUDRATE_TABLE:
3255 List of legal baudrate settings for this board.
3257 - CONFIG_SYS_CONSOLE_INFO_QUIET
3258 Suppress display of console information at boot.
3260 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3261 If the board specific function
3262 extern int overwrite_console (void);
3263 returns 1, the stdin, stderr and stdout are switched to the
3264 serial port, else the settings in the environment are used.
3266 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3267 Enable the call to overwrite_console().
3269 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3270 Enable overwrite of previous console environment settings.
3272 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3273 Begin and End addresses of the area used by the
3276 - CONFIG_SYS_ALT_MEMTEST:
3277 Enable an alternate, more extensive memory test.
3279 - CONFIG_SYS_MEMTEST_SCRATCH:
3280 Scratch address used by the alternate memory test
3281 You only need to set this if address zero isn't writeable
3283 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3284 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3285 this specified memory area will get subtracted from the top
3286 (end) of RAM and won't get "touched" at all by U-Boot. By
3287 fixing up gd->ram_size the Linux kernel should gets passed
3288 the now "corrected" memory size and won't touch it either.
3289 This should work for arch/ppc and arch/powerpc. Only Linux
3290 board ports in arch/powerpc with bootwrapper support that
3291 recalculate the memory size from the SDRAM controller setup
3292 will have to get fixed in Linux additionally.
3294 This option can be used as a workaround for the 440EPx/GRx
3295 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3298 WARNING: Please make sure that this value is a multiple of
3299 the Linux page size (normally 4k). If this is not the case,
3300 then the end address of the Linux memory will be located at a
3301 non page size aligned address and this could cause major
3304 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3305 Enable temporary baudrate change while serial download
3307 - CONFIG_SYS_SDRAM_BASE:
3308 Physical start address of SDRAM. _Must_ be 0 here.
3310 - CONFIG_SYS_MBIO_BASE:
3311 Physical start address of Motherboard I/O (if using a
3314 - CONFIG_SYS_FLASH_BASE:
3315 Physical start address of Flash memory.
3317 - CONFIG_SYS_MONITOR_BASE:
3318 Physical start address of boot monitor code (set by
3319 make config files to be same as the text base address
3320 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3321 CONFIG_SYS_FLASH_BASE when booting from flash.
3323 - CONFIG_SYS_MONITOR_LEN:
3324 Size of memory reserved for monitor code, used to
3325 determine _at_compile_time_ (!) if the environment is
3326 embedded within the U-Boot image, or in a separate
3329 - CONFIG_SYS_MALLOC_LEN:
3330 Size of DRAM reserved for malloc() use.
3332 - CONFIG_SYS_BOOTM_LEN:
3333 Normally compressed uImages are limited to an
3334 uncompressed size of 8 MBytes. If this is not enough,
3335 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3336 to adjust this setting to your needs.
3338 - CONFIG_SYS_BOOTMAPSZ:
3339 Maximum size of memory mapped by the startup code of
3340 the Linux kernel; all data that must be processed by
3341 the Linux kernel (bd_info, boot arguments, FDT blob if
3342 used) must be put below this limit, unless "bootm_low"
3343 enviroment variable is defined and non-zero. In such case
3344 all data for the Linux kernel must be between "bootm_low"
3345 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3346 variable "bootm_mapsize" will override the value of
3347 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3348 then the value in "bootm_size" will be used instead.
3350 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3351 Enable initrd_high functionality. If defined then the
3352 initrd_high feature is enabled and the bootm ramdisk subcommand
3355 - CONFIG_SYS_BOOT_GET_CMDLINE:
3356 Enables allocating and saving kernel cmdline in space between
3357 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3359 - CONFIG_SYS_BOOT_GET_KBD:
3360 Enables allocating and saving a kernel copy of the bd_info in
3361 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3363 - CONFIG_SYS_MAX_FLASH_BANKS:
3364 Max number of Flash memory banks
3366 - CONFIG_SYS_MAX_FLASH_SECT:
3367 Max number of sectors on a Flash chip
3369 - CONFIG_SYS_FLASH_ERASE_TOUT:
3370 Timeout for Flash erase operations (in ms)
3372 - CONFIG_SYS_FLASH_WRITE_TOUT:
3373 Timeout for Flash write operations (in ms)
3375 - CONFIG_SYS_FLASH_LOCK_TOUT
3376 Timeout for Flash set sector lock bit operation (in ms)
3378 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3379 Timeout for Flash clear lock bits operation (in ms)
3381 - CONFIG_SYS_FLASH_PROTECTION
3382 If defined, hardware flash sectors protection is used
3383 instead of U-Boot software protection.
3385 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3387 Enable TFTP transfers directly to flash memory;
3388 without this option such a download has to be
3389 performed in two steps: (1) download to RAM, and (2)
3390 copy from RAM to flash.
3392 The two-step approach is usually more reliable, since
3393 you can check if the download worked before you erase
3394 the flash, but in some situations (when system RAM is
3395 too limited to allow for a temporary copy of the
3396 downloaded image) this option may be very useful.
3398 - CONFIG_SYS_FLASH_CFI:
3399 Define if the flash driver uses extra elements in the
3400 common flash structure for storing flash geometry.
3402 - CONFIG_FLASH_CFI_DRIVER
3403 This option also enables the building of the cfi_flash driver
3404 in the drivers directory
3406 - CONFIG_FLASH_CFI_MTD
3407 This option enables the building of the cfi_mtd driver
3408 in the drivers directory. The driver exports CFI flash
3411 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3412 Use buffered writes to flash.
3414 - CONFIG_FLASH_SPANSION_S29WS_N
3415 s29ws-n MirrorBit flash has non-standard addresses for buffered
3418 - CONFIG_SYS_FLASH_QUIET_TEST
3419 If this option is defined, the common CFI flash doesn't
3420 print it's warning upon not recognized FLASH banks. This
3421 is useful, if some of the configured banks are only
3422 optionally available.
3424 - CONFIG_FLASH_SHOW_PROGRESS
3425 If defined (must be an integer), print out countdown
3426 digits and dots. Recommended value: 45 (9..1) for 80
3427 column displays, 15 (3..1) for 40 column displays.
3429 - CONFIG_FLASH_VERIFY
3430 If defined, the content of the flash (destination) is compared
3431 against the source after the write operation. An error message
3432 will be printed when the contents are not identical.
3433 Please note that this option is useless in nearly all cases,
3434 since such flash programming errors usually are detected earlier
3435 while unprotecting/erasing/programming. Please only enable
3436 this option if you really know what you are doing.
3438 - CONFIG_SYS_RX_ETH_BUFFER:
3439 Defines the number of Ethernet receive buffers. On some
3440 Ethernet controllers it is recommended to set this value
3441 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3442 buffers can be full shortly after enabling the interface
3443 on high Ethernet traffic.
3444 Defaults to 4 if not defined.
3446 - CONFIG_ENV_MAX_ENTRIES
3448 Maximum number of entries in the hash table that is used
3449 internally to store the environment settings. The default
3450 setting is supposed to be generous and should work in most
3451 cases. This setting can be used to tune behaviour; see
3452 lib/hashtable.c for details.
3454 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3455 - CONFIG_ENV_FLAGS_LIST_STATIC
3456 Enable validation of the values given to enviroment variables when
3457 calling env set. Variables can be restricted to only decimal,
3458 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3459 the variables can also be restricted to IP address or MAC address.
3461 The format of the list is:
3462 type_attribute = [s|d|x|b|i|m]
3463 access_atribute = [a|r|o|c]
3464 attributes = type_attribute[access_atribute]
3465 entry = variable_name[:attributes]
3468 The type attributes are:
3469 s - String (default)
3472 b - Boolean ([1yYtT|0nNfF])
3476 The access attributes are:
3482 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3483 Define this to a list (string) to define the ".flags"
3484 envirnoment variable in the default or embedded environment.
3486 - CONFIG_ENV_FLAGS_LIST_STATIC
3487 Define this to a list (string) to define validation that
3488 should be done if an entry is not found in the ".flags"
3489 environment variable. To override a setting in the static
3490 list, simply add an entry for the same variable name to the
3493 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3494 If defined, don't allow the -f switch to env set override variable
3497 - CONFIG_SYS_GENERIC_BOARD
3498 This selects the architecture-generic board system instead of the
3499 architecture-specific board files. It is intended to move boards
3500 to this new framework over time. Defining this will disable the
3501 arch/foo/lib/board.c file and use common/board_f.c and
3502 common/board_r.c instead. To use this option your architecture
3503 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3504 its config.mk file). If you find problems enabling this option on
3505 your board please report the problem and send patches!
3507 - CONFIG_SYS_SYM_OFFSETS
3508 This is set by architectures that use offsets for link symbols
3509 instead of absolute values. So bss_start is obtained using an
3510 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3511 directly. You should not need to touch this setting.
3513 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3514 This is set by OMAP boards for the max time that reset should
3515 be asserted. See doc/README.omap-reset-time for details on how
3516 the value can be calulated on a given board.
3518 The following definitions that deal with the placement and management
3519 of environment data (variable area); in general, we support the
3520 following configurations:
3522 - CONFIG_BUILD_ENVCRC:
3524 Builds up envcrc with the target environment so that external utils
3525 may easily extract it and embed it in final U-Boot images.
3527 - CONFIG_ENV_IS_IN_FLASH:
3529 Define this if the environment is in flash memory.
3531 a) The environment occupies one whole flash sector, which is
3532 "embedded" in the text segment with the U-Boot code. This
3533 happens usually with "bottom boot sector" or "top boot
3534 sector" type flash chips, which have several smaller
3535 sectors at the start or the end. For instance, such a
3536 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3537 such a case you would place the environment in one of the
3538 4 kB sectors - with U-Boot code before and after it. With
3539 "top boot sector" type flash chips, you would put the
3540 environment in one of the last sectors, leaving a gap
3541 between U-Boot and the environment.
3543 - CONFIG_ENV_OFFSET:
3545 Offset of environment data (variable area) to the
3546 beginning of flash memory; for instance, with bottom boot
3547 type flash chips the second sector can be used: the offset
3548 for this sector is given here.
3550 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3554 This is just another way to specify the start address of
3555 the flash sector containing the environment (instead of
3558 - CONFIG_ENV_SECT_SIZE:
3560 Size of the sector containing the environment.
3563 b) Sometimes flash chips have few, equal sized, BIG sectors.
3564 In such a case you don't want to spend a whole sector for
3569 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3570 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3571 of this flash sector for the environment. This saves
3572 memory for the RAM copy of the environment.
3574 It may also save flash memory if you decide to use this
3575 when your environment is "embedded" within U-Boot code,
3576 since then the remainder of the flash sector could be used
3577 for U-Boot code. It should be pointed out that this is
3578 STRONGLY DISCOURAGED from a robustness point of view:
3579 updating the environment in flash makes it always
3580 necessary to erase the WHOLE sector. If something goes
3581 wrong before the contents has been restored from a copy in
3582 RAM, your target system will be dead.
3584 - CONFIG_ENV_ADDR_REDUND
3585 CONFIG_ENV_SIZE_REDUND
3587 These settings describe a second storage area used to hold
3588 a redundant copy of the environment data, so that there is
3589 a valid backup copy in case there is a power failure during
3590 a "saveenv" operation.
3592 BE CAREFUL! Any changes to the flash layout, and some changes to the
3593 source code will make it necessary to adapt <board>/u-boot.lds*
3597 - CONFIG_ENV_IS_IN_NVRAM:
3599 Define this if you have some non-volatile memory device
3600 (NVRAM, battery buffered SRAM) which you want to use for the
3606 These two #defines are used to determine the memory area you
3607 want to use for environment. It is assumed that this memory
3608 can just be read and written to, without any special
3611 BE CAREFUL! The first access to the environment happens quite early
3612 in U-Boot initalization (when we try to get the setting of for the
3613 console baudrate). You *MUST* have mapped your NVRAM area then, or
3616 Please note that even with NVRAM we still use a copy of the
3617 environment in RAM: we could work on NVRAM directly, but we want to
3618 keep settings there always unmodified except somebody uses "saveenv"
3619 to save the current settings.
3622 - CONFIG_ENV_IS_IN_EEPROM:
3624 Use this if you have an EEPROM or similar serial access
3625 device and a driver for it.
3627 - CONFIG_ENV_OFFSET:
3630 These two #defines specify the offset and size of the
3631 environment area within the total memory of your EEPROM.
3633 - CONFIG_SYS_I2C_EEPROM_ADDR:
3634 If defined, specified the chip address of the EEPROM device.
3635 The default address is zero.
3637 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3638 If defined, the number of bits used to address bytes in a
3639 single page in the EEPROM device. A 64 byte page, for example
3640 would require six bits.
3642 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3643 If defined, the number of milliseconds to delay between
3644 page writes. The default is zero milliseconds.
3646 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3647 The length in bytes of the EEPROM memory array address. Note
3648 that this is NOT the chip address length!
3650 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3651 EEPROM chips that implement "address overflow" are ones
3652 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3653 address and the extra bits end up in the "chip address" bit
3654 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3657 Note that we consider the length of the address field to
3658 still be one byte because the extra address bits are hidden
3659 in the chip address.
3661 - CONFIG_SYS_EEPROM_SIZE:
3662 The size in bytes of the EEPROM device.
3664 - CONFIG_ENV_EEPROM_IS_ON_I2C
3665 define this, if you have I2C and SPI activated, and your
3666 EEPROM, which holds the environment, is on the I2C bus.
3668 - CONFIG_I2C_ENV_EEPROM_BUS
3669 if you have an Environment on an EEPROM reached over
3670 I2C muxes, you can define here, how to reach this
3671 EEPROM. For example:
3673 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3675 EEPROM which holds the environment, is reached over
3676 a pca9547 i2c mux with address 0x70, channel 3.
3678 - CONFIG_ENV_IS_IN_DATAFLASH:
3680 Define this if you have a DataFlash memory device which you
3681 want to use for the environment.
3683 - CONFIG_ENV_OFFSET:
3687 These three #defines specify the offset and size of the
3688 environment area within the total memory of your DataFlash placed
3689 at the specified address.
3691 - CONFIG_ENV_IS_IN_REMOTE:
3693 Define this if you have a remote memory space which you
3694 want to use for the local device's environment.
3699 These two #defines specify the address and size of the
3700 environment area within the remote memory space. The
3701 local device can get the environment from remote memory
3702 space by SRIO or PCIE links.
3704 BE CAREFUL! For some special cases, the local device can not use
3705 "saveenv" command. For example, the local device will get the
3706 environment stored in a remote NOR flash by SRIO or PCIE link,
3707 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3709 - CONFIG_ENV_IS_IN_NAND:
3711 Define this if you have a NAND device which you want to use
3712 for the environment.
3714 - CONFIG_ENV_OFFSET:
3717 These two #defines specify the offset and size of the environment
3718 area within the first NAND device. CONFIG_ENV_OFFSET must be
3719 aligned to an erase block boundary.
3721 - CONFIG_ENV_OFFSET_REDUND (optional):
3723 This setting describes a second storage area of CONFIG_ENV_SIZE
3724 size used to hold a redundant copy of the environment data, so
3725 that there is a valid backup copy in case there is a power failure
3726 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3727 aligned to an erase block boundary.
3729 - CONFIG_ENV_RANGE (optional):
3731 Specifies the length of the region in which the environment
3732 can be written. This should be a multiple of the NAND device's
3733 block size. Specifying a range with more erase blocks than
3734 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3735 the range to be avoided.
3737 - CONFIG_ENV_OFFSET_OOB (optional):
3739 Enables support for dynamically retrieving the offset of the
3740 environment from block zero's out-of-band data. The
3741 "nand env.oob" command can be used to record this offset.
3742 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3743 using CONFIG_ENV_OFFSET_OOB.
3745 - CONFIG_NAND_ENV_DST
3747 Defines address in RAM to which the nand_spl code should copy the
3748 environment. If redundant environment is used, it will be copied to
3749 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3751 - CONFIG_ENV_IS_IN_UBI:
3753 Define this if you have an UBI volume that you want to use for the
3754 environment. This has the benefit of wear-leveling the environment
3755 accesses, which is important on NAND.
3757 - CONFIG_ENV_UBI_PART:
3759 Define this to a string that is the mtd partition containing the UBI.
3761 - CONFIG_ENV_UBI_VOLUME:
3763 Define this to the name of the volume that you want to store the
3766 - CONFIG_ENV_UBI_VOLUME_REDUND:
3768 Define this to the name of another volume to store a second copy of
3769 the environment in. This will enable redundant environments in UBI.
3770 It is assumed that both volumes are in the same MTD partition.
3772 - CONFIG_UBI_SILENCE_MSG
3773 - CONFIG_UBIFS_SILENCE_MSG
3775 You will probably want to define these to avoid a really noisy system
3776 when storing the env in UBI.
3778 - CONFIG_ENV_IS_IN_MMC:
3780 Define this if you have an MMC device which you want to use for the
3783 - CONFIG_SYS_MMC_ENV_DEV:
3785 Specifies which MMC device the environment is stored in.
3787 - CONFIG_SYS_MMC_ENV_PART (optional):
3789 Specifies which MMC partition the environment is stored in. If not
3790 set, defaults to partition 0, the user area. Common values might be
3791 1 (first MMC boot partition), 2 (second MMC boot partition).
3793 - CONFIG_ENV_OFFSET:
3796 These two #defines specify the offset and size of the environment
3797 area within the specified MMC device.
3799 If offset is positive (the usual case), it is treated as relative to
3800 the start of the MMC partition. If offset is negative, it is treated
3801 as relative to the end of the MMC partition. This can be useful if
3802 your board may be fitted with different MMC devices, which have
3803 different sizes for the MMC partitions, and you always want the
3804 environment placed at the very end of the partition, to leave the
3805 maximum possible space before it, to store other data.
3807 These two values are in units of bytes, but must be aligned to an
3808 MMC sector boundary.
3810 - CONFIG_ENV_OFFSET_REDUND (optional):
3812 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3813 hold a redundant copy of the environment data. This provides a
3814 valid backup copy in case the other copy is corrupted, e.g. due
3815 to a power failure during a "saveenv" operation.
3817 This value may also be positive or negative; this is handled in the
3818 same way as CONFIG_ENV_OFFSET.
3820 This value is also in units of bytes, but must also be aligned to
3821 an MMC sector boundary.
3823 - CONFIG_ENV_SIZE_REDUND (optional):
3825 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3826 set. If this value is set, it must be set to the same value as
3829 - CONFIG_SYS_SPI_INIT_OFFSET
3831 Defines offset to the initial SPI buffer area in DPRAM. The
3832 area is used at an early stage (ROM part) if the environment
3833 is configured to reside in the SPI EEPROM: We need a 520 byte
3834 scratch DPRAM area. It is used between the two initialization
3835 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3836 to be a good choice since it makes it far enough from the
3837 start of the data area as well as from the stack pointer.
3839 Please note that the environment is read-only until the monitor
3840 has been relocated to RAM and a RAM copy of the environment has been
3841 created; also, when using EEPROM you will have to use getenv_f()
3842 until then to read environment variables.
3844 The environment is protected by a CRC32 checksum. Before the monitor
3845 is relocated into RAM, as a result of a bad CRC you will be working
3846 with the compiled-in default environment - *silently*!!! [This is
3847 necessary, because the first environment variable we need is the
3848 "baudrate" setting for the console - if we have a bad CRC, we don't
3849 have any device yet where we could complain.]
3851 Note: once the monitor has been relocated, then it will complain if
3852 the default environment is used; a new CRC is computed as soon as you
3853 use the "saveenv" command to store a valid environment.
3855 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3856 Echo the inverted Ethernet link state to the fault LED.
3858 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3859 also needs to be defined.
3861 - CONFIG_SYS_FAULT_MII_ADDR:
3862 MII address of the PHY to check for the Ethernet link state.
3864 - CONFIG_NS16550_MIN_FUNCTIONS:
3865 Define this if you desire to only have use of the NS16550_init
3866 and NS16550_putc functions for the serial driver located at
3867 drivers/serial/ns16550.c. This option is useful for saving
3868 space for already greatly restricted images, including but not
3869 limited to NAND_SPL configurations.
3871 - CONFIG_DISPLAY_BOARDINFO
3872 Display information about the board that U-Boot is running on
3873 when U-Boot starts up. The board function checkboard() is called
3876 - CONFIG_DISPLAY_BOARDINFO_LATE
3877 Similar to the previous option, but display this information
3878 later, once stdio is running and output goes to the LCD, if
3881 Low Level (hardware related) configuration options:
3882 ---------------------------------------------------
3884 - CONFIG_SYS_CACHELINE_SIZE:
3885 Cache Line Size of the CPU.
3887 - CONFIG_SYS_DEFAULT_IMMR:
3888 Default address of the IMMR after system reset.
3890 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3891 and RPXsuper) to be able to adjust the position of
3892 the IMMR register after a reset.
3894 - CONFIG_SYS_CCSRBAR_DEFAULT:
3895 Default (power-on reset) physical address of CCSR on Freescale
3898 - CONFIG_SYS_CCSRBAR:
3899 Virtual address of CCSR. On a 32-bit build, this is typically
3900 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3902 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3903 for cross-platform code that uses that macro instead.
3905 - CONFIG_SYS_CCSRBAR_PHYS:
3906 Physical address of CCSR. CCSR can be relocated to a new
3907 physical address, if desired. In this case, this macro should
3908 be set to that address. Otherwise, it should be set to the
3909 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3910 is typically relocated on 36-bit builds. It is recommended
3911 that this macro be defined via the _HIGH and _LOW macros:
3913 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3914 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3916 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3917 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3918 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3919 used in assembly code, so it must not contain typecasts or
3920 integer size suffixes (e.g. "ULL").
3922 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3923 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3924 used in assembly code, so it must not contain typecasts or
3925 integer size suffixes (e.g. "ULL").
3927 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3928 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3929 forced to a value that ensures that CCSR is not relocated.
3931 - Floppy Disk Support:
3932 CONFIG_SYS_FDC_DRIVE_NUMBER
3934 the default drive number (default value 0)
3936 CONFIG_SYS_ISA_IO_STRIDE
3938 defines the spacing between FDC chipset registers
3941 CONFIG_SYS_ISA_IO_OFFSET
3943 defines the offset of register from address. It
3944 depends on which part of the data bus is connected to
3945 the FDC chipset. (default value 0)
3947 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3948 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3951 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3952 fdc_hw_init() is called at the beginning of the FDC
3953 setup. fdc_hw_init() must be provided by the board
3954 source code. It is used to make hardware dependant
3958 Most IDE controllers were designed to be connected with PCI
3959 interface. Only few of them were designed for AHB interface.
3960 When software is doing ATA command and data transfer to
3961 IDE devices through IDE-AHB controller, some additional
3962 registers accessing to these kind of IDE-AHB controller
3965 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3966 DO NOT CHANGE unless you know exactly what you're
3967 doing! (11-4) [MPC8xx/82xx systems only]
3969 - CONFIG_SYS_INIT_RAM_ADDR:
3971 Start address of memory area that can be used for
3972 initial data and stack; please note that this must be
3973 writable memory that is working WITHOUT special
3974 initialization, i. e. you CANNOT use normal RAM which
3975 will become available only after programming the
3976 memory controller and running certain initialization
3979 U-Boot uses the following memory types:
3980 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3981 - MPC824X: data cache
3982 - PPC4xx: data cache
3984 - CONFIG_SYS_GBL_DATA_OFFSET:
3986 Offset of the initial data structure in the memory
3987 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3988 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3989 data is located at the end of the available space
3990 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3991 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3992 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3993 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3996 On the MPC824X (or other systems that use the data
3997 cache for initial memory) the address chosen for
3998 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3999 point to an otherwise UNUSED address space between
4000 the top of RAM and the start of the PCI space.
4002 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4004 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4006 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4008 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4010 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4012 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4014 - CONFIG_SYS_OR_TIMING_SDRAM:
4017 - CONFIG_SYS_MAMR_PTA:
4018 periodic timer for refresh
4020 - CONFIG_SYS_DER: Debug Event Register (37-47)
4022 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4023 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4024 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4025 CONFIG_SYS_BR1_PRELIM:
4026 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4028 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4029 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4030 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4031 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4033 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4034 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4035 Machine Mode Register and Memory Periodic Timer
4036 Prescaler definitions (SDRAM timing)
4038 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4039 enable I2C microcode relocation patch (MPC8xx);
4040 define relocation offset in DPRAM [DSP2]
4042 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4043 enable SMC microcode relocation patch (MPC8xx);
4044 define relocation offset in DPRAM [SMC1]
4046 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4047 enable SPI microcode relocation patch (MPC8xx);
4048 define relocation offset in DPRAM [SCC4]
4050 - CONFIG_SYS_USE_OSCCLK:
4051 Use OSCM clock mode on MBX8xx board. Be careful,
4052 wrong setting might damage your board. Read
4053 doc/README.MBX before setting this variable!
4055 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4056 Offset of the bootmode word in DPRAM used by post
4057 (Power On Self Tests). This definition overrides
4058 #define'd default value in commproc.h resp.
4061 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4062 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4063 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4064 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4065 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4066 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4067 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4068 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4069 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4071 - CONFIG_PCI_DISABLE_PCIE:
4072 Disable PCI-Express on systems where it is supported but not
4075 - CONFIG_PCI_ENUM_ONLY
4076 Only scan through and get the devices on the busses.
4077 Don't do any setup work, presumably because someone or
4078 something has already done it, and we don't need to do it
4079 a second time. Useful for platforms that are pre-booted
4080 by coreboot or similar.
4082 - CONFIG_PCI_INDIRECT_BRIDGE:
4083 Enable support for indirect PCI bridges.
4086 Chip has SRIO or not
4089 Board has SRIO 1 port available
4092 Board has SRIO 2 port available
4094 - CONFIG_SRIO_PCIE_BOOT_MASTER
4095 Board can support master function for Boot from SRIO and PCIE
4097 - CONFIG_SYS_SRIOn_MEM_VIRT:
4098 Virtual Address of SRIO port 'n' memory region
4100 - CONFIG_SYS_SRIOn_MEM_PHYS:
4101 Physical Address of SRIO port 'n' memory region
4103 - CONFIG_SYS_SRIOn_MEM_SIZE:
4104 Size of SRIO port 'n' memory region
4106 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4107 Defined to tell the NAND controller that the NAND chip is using
4109 Not all NAND drivers use this symbol.
4110 Example of drivers that use it:
4111 - drivers/mtd/nand/ndfc.c
4112 - drivers/mtd/nand/mxc_nand.c
4114 - CONFIG_SYS_NDFC_EBC0_CFG
4115 Sets the EBC0_CFG register for the NDFC. If not defined
4116 a default value will be used.
4119 Get DDR timing information from an I2C EEPROM. Common
4120 with pluggable memory modules such as SODIMMs
4123 I2C address of the SPD EEPROM
4125 - CONFIG_SYS_SPD_BUS_NUM
4126 If SPD EEPROM is on an I2C bus other than the first
4127 one, specify here. Note that the value must resolve
4128 to something your driver can deal with.
4130 - CONFIG_SYS_DDR_RAW_TIMING
4131 Get DDR timing information from other than SPD. Common with
4132 soldered DDR chips onboard without SPD. DDR raw timing
4133 parameters are extracted from datasheet and hard-coded into
4134 header files or board specific files.
4136 - CONFIG_FSL_DDR_INTERACTIVE
4137 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4139 - CONFIG_SYS_83XX_DDR_USES_CS0
4140 Only for 83xx systems. If specified, then DDR should
4141 be configured using CS0 and CS1 instead of CS2 and CS3.
4143 - CONFIG_ETHER_ON_FEC[12]
4144 Define to enable FEC[12] on a 8xx series processor.
4146 - CONFIG_FEC[12]_PHY
4147 Define to the hardcoded PHY address which corresponds
4148 to the given FEC; i. e.
4149 #define CONFIG_FEC1_PHY 4
4150 means that the PHY with address 4 is connected to FEC1
4152 When set to -1, means to probe for first available.
4154 - CONFIG_FEC[12]_PHY_NORXERR
4155 The PHY does not have a RXERR line (RMII only).
4156 (so program the FEC to ignore it).
4159 Enable RMII mode for all FECs.
4160 Note that this is a global option, we can't
4161 have one FEC in standard MII mode and another in RMII mode.
4163 - CONFIG_CRC32_VERIFY
4164 Add a verify option to the crc32 command.
4167 => crc32 -v <address> <count> <crc32>
4169 Where address/count indicate a memory area
4170 and crc32 is the correct crc32 which the
4174 Add the "loopw" memory command. This only takes effect if
4175 the memory commands are activated globally (CONFIG_CMD_MEM).
4178 Add the "mdc" and "mwc" memory commands. These are cyclic
4183 This command will print 4 bytes (10,11,12,13) each 500 ms.
4185 => mwc.l 100 12345678 10
4186 This command will write 12345678 to address 100 all 10 ms.
4188 This only takes effect if the memory commands are activated
4189 globally (CONFIG_CMD_MEM).
4191 - CONFIG_SKIP_LOWLEVEL_INIT
4192 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4193 low level initializations (like setting up the memory
4194 controller) are omitted and/or U-Boot does not
4195 relocate itself into RAM.
4197 Normally this variable MUST NOT be defined. The only
4198 exception is when U-Boot is loaded (to RAM) by some
4199 other boot loader or by a debugger which performs
4200 these initializations itself.
4203 Modifies the behaviour of start.S when compiling a loader
4204 that is executed before the actual U-Boot. E.g. when
4205 compiling a NAND SPL.
4207 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4208 Only for 85xx systems. If this variable is specified, the section
4209 .resetvec is not kept and the section .bootpg is placed in the
4210 previous 4k of the .text section.
4212 - CONFIG_ARCH_MAP_SYSMEM
4213 Generally U-Boot (and in particular the md command) uses
4214 effective address. It is therefore not necessary to regard
4215 U-Boot address as virtual addresses that need to be translated
4216 to physical addresses. However, sandbox requires this, since
4217 it maintains its own little RAM buffer which contains all
4218 addressable memory. This option causes some memory accesses
4219 to be mapped through map_sysmem() / unmap_sysmem().
4221 - CONFIG_USE_ARCH_MEMCPY
4222 CONFIG_USE_ARCH_MEMSET
4223 If these options are used a optimized version of memcpy/memset will
4224 be used if available. These functions may be faster under some
4225 conditions but may increase the binary size.
4227 - CONFIG_X86_RESET_VECTOR
4228 If defined, the x86 reset vector code is included. This is not
4229 needed when U-Boot is running from Coreboot.
4232 Defines the MPU clock speed (in MHz).
4234 NOTE : currently only supported on AM335x platforms.
4236 Freescale QE/FMAN Firmware Support:
4237 -----------------------------------
4239 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4240 loading of "firmware", which is encoded in the QE firmware binary format.
4241 This firmware often needs to be loaded during U-Boot booting, so macros
4242 are used to identify the storage device (NOR flash, SPI, etc) and the address
4245 - CONFIG_SYS_QE_FMAN_FW_ADDR
4246 The address in the storage device where the firmware is located. The
4247 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4250 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4251 The maximum possible size of the firmware. The firmware binary format
4252 has a field that specifies the actual size of the firmware, but it
4253 might not be possible to read any part of the firmware unless some
4254 local storage is allocated to hold the entire firmware first.
4256 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4257 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4258 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4259 virtual address in NOR flash.
4261 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4262 Specifies that QE/FMAN firmware is located in NAND flash.
4263 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4265 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4266 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4267 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4269 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4270 Specifies that QE/FMAN firmware is located on the primary SPI
4271 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4273 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4274 Specifies that QE/FMAN firmware is located in the remote (master)
4275 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4276 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4277 window->master inbound window->master LAW->the ucode address in
4278 master's memory space.
4280 Building the Software:
4281 ======================
4283 Building U-Boot has been tested in several native build environments
4284 and in many different cross environments. Of course we cannot support
4285 all possibly existing versions of cross development tools in all
4286 (potentially obsolete) versions. In case of tool chain problems we
4287 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4288 which is extensively used to build and test U-Boot.
4290 If you are not using a native environment, it is assumed that you
4291 have GNU cross compiling tools available in your path. In this case,
4292 you must set the environment variable CROSS_COMPILE in your shell.
4293 Note that no changes to the Makefile or any other source files are
4294 necessary. For example using the ELDK on a 4xx CPU, please enter:
4296 $ CROSS_COMPILE=ppc_4xx-
4297 $ export CROSS_COMPILE
4299 Note: If you wish to generate Windows versions of the utilities in
4300 the tools directory you can use the MinGW toolchain
4301 (http://www.mingw.org). Set your HOST tools to the MinGW
4302 toolchain and execute 'make tools'. For example:
4304 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4306 Binaries such as tools/mkimage.exe will be created which can
4307 be executed on computers running Windows.
4309 U-Boot is intended to be simple to build. After installing the
4310 sources you must configure U-Boot for one specific board type. This
4315 where "NAME_config" is the name of one of the existing configu-
4316 rations; see boards.cfg for supported names.
4318 Note: for some board special configuration names may exist; check if
4319 additional information is available from the board vendor; for
4320 instance, the TQM823L systems are available without (standard)
4321 or with LCD support. You can select such additional "features"
4322 when choosing the configuration, i. e.
4325 - will configure for a plain TQM823L, i. e. no LCD support
4327 make TQM823L_LCD_config
4328 - will configure for a TQM823L with U-Boot console on LCD
4333 Finally, type "make all", and you should get some working U-Boot
4334 images ready for download to / installation on your system:
4336 - "u-boot.bin" is a raw binary image
4337 - "u-boot" is an image in ELF binary format
4338 - "u-boot.srec" is in Motorola S-Record format
4340 By default the build is performed locally and the objects are saved
4341 in the source directory. One of the two methods can be used to change
4342 this behavior and build U-Boot to some external directory:
4344 1. Add O= to the make command line invocations:
4346 make O=/tmp/build distclean
4347 make O=/tmp/build NAME_config
4348 make O=/tmp/build all
4350 2. Set environment variable BUILD_DIR to point to the desired location:
4352 export BUILD_DIR=/tmp/build
4357 Note that the command line "O=" setting overrides the BUILD_DIR environment
4361 Please be aware that the Makefiles assume you are using GNU make, so
4362 for instance on NetBSD you might need to use "gmake" instead of
4366 If the system board that you have is not listed, then you will need
4367 to port U-Boot to your hardware platform. To do this, follow these
4370 1. Add a new configuration option for your board to the toplevel
4371 "boards.cfg" file, using the existing entries as examples.
4372 Follow the instructions there to keep the boards in order.
4373 2. Create a new directory to hold your board specific code. Add any
4374 files you need. In your board directory, you will need at least
4375 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4376 3. Create a new configuration file "include/configs/<board>.h" for
4378 3. If you're porting U-Boot to a new CPU, then also create a new
4379 directory to hold your CPU specific code. Add any files you need.
4380 4. Run "make <board>_config" with your new name.
4381 5. Type "make", and you should get a working "u-boot.srec" file
4382 to be installed on your target system.
4383 6. Debug and solve any problems that might arise.
4384 [Of course, this last step is much harder than it sounds.]
4387 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4388 ==============================================================
4390 If you have modified U-Boot sources (for instance added a new board
4391 or support for new devices, a new CPU, etc.) you are expected to
4392 provide feedback to the other developers. The feedback normally takes
4393 the form of a "patch", i. e. a context diff against a certain (latest
4394 official or latest in the git repository) version of U-Boot sources.
4396 But before you submit such a patch, please verify that your modifi-
4397 cation did not break existing code. At least make sure that *ALL* of
4398 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4399 just run the "MAKEALL" script, which will configure and build U-Boot
4400 for ALL supported system. Be warned, this will take a while. You can
4401 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4402 environment variable to the script, i. e. to use the ELDK cross tools
4405 CROSS_COMPILE=ppc_8xx- MAKEALL
4407 or to build on a native PowerPC system you can type
4409 CROSS_COMPILE=' ' MAKEALL
4411 When using the MAKEALL script, the default behaviour is to build
4412 U-Boot in the source directory. This location can be changed by
4413 setting the BUILD_DIR environment variable. Also, for each target
4414 built, the MAKEALL script saves two log files (<target>.ERR and
4415 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4416 location can be changed by setting the MAKEALL_LOGDIR environment
4417 variable. For example:
4419 export BUILD_DIR=/tmp/build
4420 export MAKEALL_LOGDIR=/tmp/log
4421 CROSS_COMPILE=ppc_8xx- MAKEALL
4423 With the above settings build objects are saved in the /tmp/build,
4424 log files are saved in the /tmp/log and the source tree remains clean
4425 during the whole build process.
4428 See also "U-Boot Porting Guide" below.
4431 Monitor Commands - Overview:
4432 ============================
4434 go - start application at address 'addr'
4435 run - run commands in an environment variable
4436 bootm - boot application image from memory
4437 bootp - boot image via network using BootP/TFTP protocol
4438 bootz - boot zImage from memory
4439 tftpboot- boot image via network using TFTP protocol
4440 and env variables "ipaddr" and "serverip"
4441 (and eventually "gatewayip")
4442 tftpput - upload a file via network using TFTP protocol
4443 rarpboot- boot image via network using RARP/TFTP protocol
4444 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4445 loads - load S-Record file over serial line
4446 loadb - load binary file over serial line (kermit mode)
4448 mm - memory modify (auto-incrementing)
4449 nm - memory modify (constant address)
4450 mw - memory write (fill)
4452 cmp - memory compare
4453 crc32 - checksum calculation
4454 i2c - I2C sub-system
4455 sspi - SPI utility commands
4456 base - print or set address offset
4457 printenv- print environment variables
4458 setenv - set environment variables
4459 saveenv - save environment variables to persistent storage
4460 protect - enable or disable FLASH write protection
4461 erase - erase FLASH memory
4462 flinfo - print FLASH memory information
4463 nand - NAND memory operations (see doc/README.nand)
4464 bdinfo - print Board Info structure
4465 iminfo - print header information for application image
4466 coninfo - print console devices and informations
4467 ide - IDE sub-system
4468 loop - infinite loop on address range
4469 loopw - infinite write loop on address range
4470 mtest - simple RAM test
4471 icache - enable or disable instruction cache
4472 dcache - enable or disable data cache
4473 reset - Perform RESET of the CPU
4474 echo - echo args to console
4475 version - print monitor version
4476 help - print online help
4477 ? - alias for 'help'
4480 Monitor Commands - Detailed Description:
4481 ========================================
4485 For now: just type "help <command>".
4488 Environment Variables:
4489 ======================
4491 U-Boot supports user configuration using Environment Variables which
4492 can be made persistent by saving to Flash memory.
4494 Environment Variables are set using "setenv", printed using
4495 "printenv", and saved to Flash using "saveenv". Using "setenv"
4496 without a value can be used to delete a variable from the
4497 environment. As long as you don't save the environment you are
4498 working with an in-memory copy. In case the Flash area containing the
4499 environment is erased by accident, a default environment is provided.
4501 Some configuration options can be set using Environment Variables.
4503 List of environment variables (most likely not complete):
4505 baudrate - see CONFIG_BAUDRATE
4507 bootdelay - see CONFIG_BOOTDELAY
4509 bootcmd - see CONFIG_BOOTCOMMAND
4511 bootargs - Boot arguments when booting an RTOS image
4513 bootfile - Name of the image to load with TFTP
4515 bootm_low - Memory range available for image processing in the bootm
4516 command can be restricted. This variable is given as
4517 a hexadecimal number and defines lowest address allowed
4518 for use by the bootm command. See also "bootm_size"
4519 environment variable. Address defined by "bootm_low" is
4520 also the base of the initial memory mapping for the Linux
4521 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4524 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4525 This variable is given as a hexadecimal number and it
4526 defines the size of the memory region starting at base
4527 address bootm_low that is accessible by the Linux kernel
4528 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4529 as the default value if it is defined, and bootm_size is
4532 bootm_size - Memory range available for image processing in the bootm
4533 command can be restricted. This variable is given as
4534 a hexadecimal number and defines the size of the region
4535 allowed for use by the bootm command. See also "bootm_low"
4536 environment variable.
4538 updatefile - Location of the software update file on a TFTP server, used
4539 by the automatic software update feature. Please refer to
4540 documentation in doc/README.update for more details.
4542 autoload - if set to "no" (any string beginning with 'n'),
4543 "bootp" will just load perform a lookup of the
4544 configuration from the BOOTP server, but not try to
4545 load any image using TFTP
4547 autostart - if set to "yes", an image loaded using the "bootp",
4548 "rarpboot", "tftpboot" or "diskboot" commands will
4549 be automatically started (by internally calling
4552 If set to "no", a standalone image passed to the
4553 "bootm" command will be copied to the load address
4554 (and eventually uncompressed), but NOT be started.
4555 This can be used to load and uncompress arbitrary
4558 fdt_high - if set this restricts the maximum address that the
4559 flattened device tree will be copied into upon boot.
4560 For example, if you have a system with 1 GB memory
4561 at physical address 0x10000000, while Linux kernel
4562 only recognizes the first 704 MB as low memory, you
4563 may need to set fdt_high as 0x3C000000 to have the
4564 device tree blob be copied to the maximum address
4565 of the 704 MB low memory, so that Linux kernel can
4566 access it during the boot procedure.
4568 If this is set to the special value 0xFFFFFFFF then
4569 the fdt will not be copied at all on boot. For this
4570 to work it must reside in writable memory, have
4571 sufficient padding on the end of it for u-boot to
4572 add the information it needs into it, and the memory
4573 must be accessible by the kernel.
4575 fdtcontroladdr- if set this is the address of the control flattened
4576 device tree used by U-Boot when CONFIG_OF_CONTROL is
4579 i2cfast - (PPC405GP|PPC405EP only)
4580 if set to 'y' configures Linux I2C driver for fast
4581 mode (400kHZ). This environment variable is used in
4582 initialization code. So, for changes to be effective
4583 it must be saved and board must be reset.
4585 initrd_high - restrict positioning of initrd images:
4586 If this variable is not set, initrd images will be
4587 copied to the highest possible address in RAM; this
4588 is usually what you want since it allows for
4589 maximum initrd size. If for some reason you want to
4590 make sure that the initrd image is loaded below the
4591 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4592 variable to a value of "no" or "off" or "0".
4593 Alternatively, you can set it to a maximum upper
4594 address to use (U-Boot will still check that it
4595 does not overwrite the U-Boot stack and data).
4597 For instance, when you have a system with 16 MB
4598 RAM, and want to reserve 4 MB from use by Linux,
4599 you can do this by adding "mem=12M" to the value of
4600 the "bootargs" variable. However, now you must make
4601 sure that the initrd image is placed in the first
4602 12 MB as well - this can be done with
4604 setenv initrd_high 00c00000
4606 If you set initrd_high to 0xFFFFFFFF, this is an
4607 indication to U-Boot that all addresses are legal
4608 for the Linux kernel, including addresses in flash
4609 memory. In this case U-Boot will NOT COPY the
4610 ramdisk at all. This may be useful to reduce the
4611 boot time on your system, but requires that this
4612 feature is supported by your Linux kernel.
4614 ipaddr - IP address; needed for tftpboot command
4616 loadaddr - Default load address for commands like "bootp",
4617 "rarpboot", "tftpboot", "loadb" or "diskboot"
4619 loads_echo - see CONFIG_LOADS_ECHO
4621 serverip - TFTP server IP address; needed for tftpboot command
4623 bootretry - see CONFIG_BOOT_RETRY_TIME
4625 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4627 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4629 ethprime - controls which interface is used first.
4631 ethact - controls which interface is currently active.
4632 For example you can do the following
4634 => setenv ethact FEC
4635 => ping 192.168.0.1 # traffic sent on FEC
4636 => setenv ethact SCC
4637 => ping 10.0.0.1 # traffic sent on SCC
4639 ethrotate - When set to "no" U-Boot does not go through all
4640 available network interfaces.
4641 It just stays at the currently selected interface.
4643 netretry - When set to "no" each network operation will
4644 either succeed or fail without retrying.
4645 When set to "once" the network operation will
4646 fail when all the available network interfaces
4647 are tried once without success.
4648 Useful on scripts which control the retry operation
4651 npe_ucode - set load address for the NPE microcode
4653 silent_linux - If set then linux will be told to boot silently, by
4654 changing the console to be empty. If "yes" it will be
4655 made silent. If "no" it will not be made silent. If
4656 unset, then it will be made silent if the U-Boot console
4659 tftpsrcport - If this is set, the value is used for TFTP's
4662 tftpdstport - If this is set, the value is used for TFTP's UDP
4663 destination port instead of the Well Know Port 69.
4665 tftpblocksize - Block size to use for TFTP transfers; if not set,
4666 we use the TFTP server's default block size
4668 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4669 seconds, minimum value is 1000 = 1 second). Defines
4670 when a packet is considered to be lost so it has to
4671 be retransmitted. The default is 5000 = 5 seconds.
4672 Lowering this value may make downloads succeed
4673 faster in networks with high packet loss rates or
4674 with unreliable TFTP servers.
4676 vlan - When set to a value < 4095 the traffic over
4677 Ethernet is encapsulated/received over 802.1q
4680 The following image location variables contain the location of images
4681 used in booting. The "Image" column gives the role of the image and is
4682 not an environment variable name. The other columns are environment
4683 variable names. "File Name" gives the name of the file on a TFTP
4684 server, "RAM Address" gives the location in RAM the image will be
4685 loaded to, and "Flash Location" gives the image's address in NOR
4686 flash or offset in NAND flash.
4688 *Note* - these variables don't have to be defined for all boards, some
4689 boards currenlty use other variables for these purposes, and some
4690 boards use these variables for other purposes.
4692 Image File Name RAM Address Flash Location
4693 ----- --------- ----------- --------------
4694 u-boot u-boot u-boot_addr_r u-boot_addr
4695 Linux kernel bootfile kernel_addr_r kernel_addr
4696 device tree blob fdtfile fdt_addr_r fdt_addr
4697 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4699 The following environment variables may be used and automatically
4700 updated by the network boot commands ("bootp" and "rarpboot"),
4701 depending the information provided by your boot server:
4703 bootfile - see above
4704 dnsip - IP address of your Domain Name Server
4705 dnsip2 - IP address of your secondary Domain Name Server
4706 gatewayip - IP address of the Gateway (Router) to use
4707 hostname - Target hostname
4709 netmask - Subnet Mask
4710 rootpath - Pathname of the root filesystem on the NFS server
4711 serverip - see above
4714 There are two special Environment Variables:
4716 serial# - contains hardware identification information such
4717 as type string and/or serial number
4718 ethaddr - Ethernet address
4720 These variables can be set only once (usually during manufacturing of
4721 the board). U-Boot refuses to delete or overwrite these variables
4722 once they have been set once.
4725 Further special Environment Variables:
4727 ver - Contains the U-Boot version string as printed
4728 with the "version" command. This variable is
4729 readonly (see CONFIG_VERSION_VARIABLE).
4732 Please note that changes to some configuration parameters may take
4733 only effect after the next boot (yes, that's just like Windoze :-).
4736 Callback functions for environment variables:
4737 ---------------------------------------------
4739 For some environment variables, the behavior of u-boot needs to change
4740 when their values are changed. This functionailty allows functions to
4741 be associated with arbitrary variables. On creation, overwrite, or
4742 deletion, the callback will provide the opportunity for some side
4743 effect to happen or for the change to be rejected.
4745 The callbacks are named and associated with a function using the
4746 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4748 These callbacks are associated with variables in one of two ways. The
4749 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4750 in the board configuration to a string that defines a list of
4751 associations. The list must be in the following format:
4753 entry = variable_name[:callback_name]
4756 If the callback name is not specified, then the callback is deleted.
4757 Spaces are also allowed anywhere in the list.
4759 Callbacks can also be associated by defining the ".callbacks" variable
4760 with the same list format above. Any association in ".callbacks" will
4761 override any association in the static list. You can define
4762 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4763 ".callbacks" envirnoment variable in the default or embedded environment.
4766 Command Line Parsing:
4767 =====================
4769 There are two different command line parsers available with U-Boot:
4770 the old "simple" one, and the much more powerful "hush" shell:
4772 Old, simple command line parser:
4773 --------------------------------
4775 - supports environment variables (through setenv / saveenv commands)
4776 - several commands on one line, separated by ';'
4777 - variable substitution using "... ${name} ..." syntax
4778 - special characters ('$', ';') can be escaped by prefixing with '\',
4780 setenv bootcmd bootm \${address}
4781 - You can also escape text by enclosing in single apostrophes, for example:
4782 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4787 - similar to Bourne shell, with control structures like
4788 if...then...else...fi, for...do...done; while...do...done,
4789 until...do...done, ...
4790 - supports environment ("global") variables (through setenv / saveenv
4791 commands) and local shell variables (through standard shell syntax
4792 "name=value"); only environment variables can be used with "run"
4798 (1) If a command line (or an environment variable executed by a "run"
4799 command) contains several commands separated by semicolon, and
4800 one of these commands fails, then the remaining commands will be
4803 (2) If you execute several variables with one call to run (i. e.
4804 calling run with a list of variables as arguments), any failing
4805 command will cause "run" to terminate, i. e. the remaining
4806 variables are not executed.
4808 Note for Redundant Ethernet Interfaces:
4809 =======================================
4811 Some boards come with redundant Ethernet interfaces; U-Boot supports
4812 such configurations and is capable of automatic selection of a
4813 "working" interface when needed. MAC assignment works as follows:
4815 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4816 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4817 "eth1addr" (=>eth1), "eth2addr", ...
4819 If the network interface stores some valid MAC address (for instance
4820 in SROM), this is used as default address if there is NO correspon-
4821 ding setting in the environment; if the corresponding environment
4822 variable is set, this overrides the settings in the card; that means:
4824 o If the SROM has a valid MAC address, and there is no address in the
4825 environment, the SROM's address is used.
4827 o If there is no valid address in the SROM, and a definition in the
4828 environment exists, then the value from the environment variable is
4831 o If both the SROM and the environment contain a MAC address, and
4832 both addresses are the same, this MAC address is used.
4834 o If both the SROM and the environment contain a MAC address, and the
4835 addresses differ, the value from the environment is used and a
4838 o If neither SROM nor the environment contain a MAC address, an error
4841 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4842 will be programmed into hardware as part of the initialization process. This
4843 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4844 The naming convention is as follows:
4845 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4850 U-Boot is capable of booting (and performing other auxiliary operations on)
4851 images in two formats:
4853 New uImage format (FIT)
4854 -----------------------
4856 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4857 to Flattened Device Tree). It allows the use of images with multiple
4858 components (several kernels, ramdisks, etc.), with contents protected by
4859 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4865 Old image format is based on binary files which can be basically anything,
4866 preceded by a special header; see the definitions in include/image.h for
4867 details; basically, the header defines the following image properties:
4869 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4870 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4871 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4872 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4874 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4875 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4876 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4877 * Compression Type (uncompressed, gzip, bzip2)
4883 The header is marked by a special Magic Number, and both the header
4884 and the data portions of the image are secured against corruption by
4891 Although U-Boot should support any OS or standalone application
4892 easily, the main focus has always been on Linux during the design of
4895 U-Boot includes many features that so far have been part of some
4896 special "boot loader" code within the Linux kernel. Also, any
4897 "initrd" images to be used are no longer part of one big Linux image;
4898 instead, kernel and "initrd" are separate images. This implementation
4899 serves several purposes:
4901 - the same features can be used for other OS or standalone
4902 applications (for instance: using compressed images to reduce the
4903 Flash memory footprint)
4905 - it becomes much easier to port new Linux kernel versions because
4906 lots of low-level, hardware dependent stuff are done by U-Boot
4908 - the same Linux kernel image can now be used with different "initrd"
4909 images; of course this also means that different kernel images can
4910 be run with the same "initrd". This makes testing easier (you don't
4911 have to build a new "zImage.initrd" Linux image when you just
4912 change a file in your "initrd"). Also, a field-upgrade of the
4913 software is easier now.
4919 Porting Linux to U-Boot based systems:
4920 ---------------------------------------
4922 U-Boot cannot save you from doing all the necessary modifications to
4923 configure the Linux device drivers for use with your target hardware
4924 (no, we don't intend to provide a full virtual machine interface to
4927 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4929 Just make sure your machine specific header file (for instance
4930 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4931 Information structure as we define in include/asm-<arch>/u-boot.h,
4932 and make sure that your definition of IMAP_ADDR uses the same value
4933 as your U-Boot configuration in CONFIG_SYS_IMMR.
4936 Configuring the Linux kernel:
4937 -----------------------------
4939 No specific requirements for U-Boot. Make sure you have some root
4940 device (initial ramdisk, NFS) for your target system.
4943 Building a Linux Image:
4944 -----------------------
4946 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4947 not used. If you use recent kernel source, a new build target
4948 "uImage" will exist which automatically builds an image usable by
4949 U-Boot. Most older kernels also have support for a "pImage" target,
4950 which was introduced for our predecessor project PPCBoot and uses a
4951 100% compatible format.
4960 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4961 encapsulate a compressed Linux kernel image with header information,
4962 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4964 * build a standard "vmlinux" kernel image (in ELF binary format):
4966 * convert the kernel into a raw binary image:
4968 ${CROSS_COMPILE}-objcopy -O binary \
4969 -R .note -R .comment \
4970 -S vmlinux linux.bin
4972 * compress the binary image:
4976 * package compressed binary image for U-Boot:
4978 mkimage -A ppc -O linux -T kernel -C gzip \
4979 -a 0 -e 0 -n "Linux Kernel Image" \
4980 -d linux.bin.gz uImage
4983 The "mkimage" tool can also be used to create ramdisk images for use
4984 with U-Boot, either separated from the Linux kernel image, or
4985 combined into one file. "mkimage" encapsulates the images with a 64
4986 byte header containing information about target architecture,
4987 operating system, image type, compression method, entry points, time
4988 stamp, CRC32 checksums, etc.
4990 "mkimage" can be called in two ways: to verify existing images and
4991 print the header information, or to build new images.
4993 In the first form (with "-l" option) mkimage lists the information
4994 contained in the header of an existing U-Boot image; this includes
4995 checksum verification:
4997 tools/mkimage -l image
4998 -l ==> list image header information
5000 The second form (with "-d" option) is used to build a U-Boot image
5001 from a "data file" which is used as image payload:
5003 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5004 -n name -d data_file image
5005 -A ==> set architecture to 'arch'
5006 -O ==> set operating system to 'os'
5007 -T ==> set image type to 'type'
5008 -C ==> set compression type 'comp'
5009 -a ==> set load address to 'addr' (hex)
5010 -e ==> set entry point to 'ep' (hex)
5011 -n ==> set image name to 'name'
5012 -d ==> use image data from 'datafile'
5014 Right now, all Linux kernels for PowerPC systems use the same load
5015 address (0x00000000), but the entry point address depends on the
5018 - 2.2.x kernels have the entry point at 0x0000000C,
5019 - 2.3.x and later kernels have the entry point at 0x00000000.
5021 So a typical call to build a U-Boot image would read:
5023 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5024 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5025 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5026 > examples/uImage.TQM850L
5027 Image Name: 2.4.4 kernel for TQM850L
5028 Created: Wed Jul 19 02:34:59 2000
5029 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5030 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5031 Load Address: 0x00000000
5032 Entry Point: 0x00000000
5034 To verify the contents of the image (or check for corruption):
5036 -> tools/mkimage -l examples/uImage.TQM850L
5037 Image Name: 2.4.4 kernel for TQM850L
5038 Created: Wed Jul 19 02:34:59 2000
5039 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5040 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5041 Load Address: 0x00000000
5042 Entry Point: 0x00000000
5044 NOTE: for embedded systems where boot time is critical you can trade
5045 speed for memory and install an UNCOMPRESSED image instead: this
5046 needs more space in Flash, but boots much faster since it does not
5047 need to be uncompressed:
5049 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5050 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5051 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5052 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5053 > examples/uImage.TQM850L-uncompressed
5054 Image Name: 2.4.4 kernel for TQM850L
5055 Created: Wed Jul 19 02:34:59 2000
5056 Image Type: PowerPC Linux Kernel Image (uncompressed)
5057 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5058 Load Address: 0x00000000
5059 Entry Point: 0x00000000
5062 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5063 when your kernel is intended to use an initial ramdisk:
5065 -> tools/mkimage -n 'Simple Ramdisk Image' \
5066 > -A ppc -O linux -T ramdisk -C gzip \
5067 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5068 Image Name: Simple Ramdisk Image
5069 Created: Wed Jan 12 14:01:50 2000
5070 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5071 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5072 Load Address: 0x00000000
5073 Entry Point: 0x00000000
5076 Installing a Linux Image:
5077 -------------------------
5079 To downloading a U-Boot image over the serial (console) interface,
5080 you must convert the image to S-Record format:
5082 objcopy -I binary -O srec examples/image examples/image.srec
5084 The 'objcopy' does not understand the information in the U-Boot
5085 image header, so the resulting S-Record file will be relative to
5086 address 0x00000000. To load it to a given address, you need to
5087 specify the target address as 'offset' parameter with the 'loads'
5090 Example: install the image to address 0x40100000 (which on the
5091 TQM8xxL is in the first Flash bank):
5093 => erase 40100000 401FFFFF
5099 ## Ready for S-Record download ...
5100 ~>examples/image.srec
5101 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5103 15989 15990 15991 15992
5104 [file transfer complete]
5106 ## Start Addr = 0x00000000
5109 You can check the success of the download using the 'iminfo' command;
5110 this includes a checksum verification so you can be sure no data
5111 corruption happened:
5115 ## Checking Image at 40100000 ...
5116 Image Name: 2.2.13 for initrd on TQM850L
5117 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5118 Data Size: 335725 Bytes = 327 kB = 0 MB
5119 Load Address: 00000000
5120 Entry Point: 0000000c
5121 Verifying Checksum ... OK
5127 The "bootm" command is used to boot an application that is stored in
5128 memory (RAM or Flash). In case of a Linux kernel image, the contents
5129 of the "bootargs" environment variable is passed to the kernel as
5130 parameters. You can check and modify this variable using the
5131 "printenv" and "setenv" commands:
5134 => printenv bootargs
5135 bootargs=root=/dev/ram
5137 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5139 => printenv bootargs
5140 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5143 ## Booting Linux kernel at 40020000 ...
5144 Image Name: 2.2.13 for NFS on TQM850L
5145 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5146 Data Size: 381681 Bytes = 372 kB = 0 MB
5147 Load Address: 00000000
5148 Entry Point: 0000000c
5149 Verifying Checksum ... OK
5150 Uncompressing Kernel Image ... OK
5151 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
5152 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5153 time_init: decrementer frequency = 187500000/60
5154 Calibrating delay loop... 49.77 BogoMIPS
5155 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5158 If you want to boot a Linux kernel with initial RAM disk, you pass
5159 the memory addresses of both the kernel and the initrd image (PPBCOOT
5160 format!) to the "bootm" command:
5162 => imi 40100000 40200000
5164 ## Checking Image at 40100000 ...
5165 Image Name: 2.2.13 for initrd on TQM850L
5166 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5167 Data Size: 335725 Bytes = 327 kB = 0 MB
5168 Load Address: 00000000
5169 Entry Point: 0000000c
5170 Verifying Checksum ... OK
5172 ## Checking Image at 40200000 ...
5173 Image Name: Simple Ramdisk Image
5174 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5175 Data Size: 566530 Bytes = 553 kB = 0 MB
5176 Load Address: 00000000
5177 Entry Point: 00000000
5178 Verifying Checksum ... OK
5180 => bootm 40100000 40200000
5181 ## Booting Linux kernel at 40100000 ...
5182 Image Name: 2.2.13 for initrd on TQM850L
5183 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5184 Data Size: 335725 Bytes = 327 kB = 0 MB
5185 Load Address: 00000000
5186 Entry Point: 0000000c
5187 Verifying Checksum ... OK
5188 Uncompressing Kernel Image ... OK
5189 ## Loading RAMDisk Image at 40200000 ...
5190 Image Name: Simple Ramdisk Image
5191 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5192 Data Size: 566530 Bytes = 553 kB = 0 MB
5193 Load Address: 00000000
5194 Entry Point: 00000000
5195 Verifying Checksum ... OK
5196 Loading Ramdisk ... OK
5197 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
5198 Boot arguments: root=/dev/ram
5199 time_init: decrementer frequency = 187500000/60
5200 Calibrating delay loop... 49.77 BogoMIPS
5202 RAMDISK: Compressed image found at block 0
5203 VFS: Mounted root (ext2 filesystem).
5207 Boot Linux and pass a flat device tree:
5210 First, U-Boot must be compiled with the appropriate defines. See the section
5211 titled "Linux Kernel Interface" above for a more in depth explanation. The
5212 following is an example of how to start a kernel and pass an updated
5218 oft=oftrees/mpc8540ads.dtb
5219 => tftp $oftaddr $oft
5220 Speed: 1000, full duplex
5222 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5223 Filename 'oftrees/mpc8540ads.dtb'.
5224 Load address: 0x300000
5227 Bytes transferred = 4106 (100a hex)
5228 => tftp $loadaddr $bootfile
5229 Speed: 1000, full duplex
5231 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5233 Load address: 0x200000
5234 Loading:############
5236 Bytes transferred = 1029407 (fb51f hex)
5241 => bootm $loadaddr - $oftaddr
5242 ## Booting image at 00200000 ...
5243 Image Name: Linux-2.6.17-dirty
5244 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5245 Data Size: 1029343 Bytes = 1005.2 kB
5246 Load Address: 00000000
5247 Entry Point: 00000000
5248 Verifying Checksum ... OK
5249 Uncompressing Kernel Image ... OK
5250 Booting using flat device tree at 0x300000
5251 Using MPC85xx ADS machine description
5252 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5256 More About U-Boot Image Types:
5257 ------------------------------
5259 U-Boot supports the following image types:
5261 "Standalone Programs" are directly runnable in the environment
5262 provided by U-Boot; it is expected that (if they behave
5263 well) you can continue to work in U-Boot after return from
5264 the Standalone Program.
5265 "OS Kernel Images" are usually images of some Embedded OS which
5266 will take over control completely. Usually these programs
5267 will install their own set of exception handlers, device
5268 drivers, set up the MMU, etc. - this means, that you cannot
5269 expect to re-enter U-Boot except by resetting the CPU.
5270 "RAMDisk Images" are more or less just data blocks, and their
5271 parameters (address, size) are passed to an OS kernel that is
5273 "Multi-File Images" contain several images, typically an OS
5274 (Linux) kernel image and one or more data images like
5275 RAMDisks. This construct is useful for instance when you want
5276 to boot over the network using BOOTP etc., where the boot
5277 server provides just a single image file, but you want to get
5278 for instance an OS kernel and a RAMDisk image.
5280 "Multi-File Images" start with a list of image sizes, each
5281 image size (in bytes) specified by an "uint32_t" in network
5282 byte order. This list is terminated by an "(uint32_t)0".
5283 Immediately after the terminating 0 follow the images, one by
5284 one, all aligned on "uint32_t" boundaries (size rounded up to
5285 a multiple of 4 bytes).
5287 "Firmware Images" are binary images containing firmware (like
5288 U-Boot or FPGA images) which usually will be programmed to
5291 "Script files" are command sequences that will be executed by
5292 U-Boot's command interpreter; this feature is especially
5293 useful when you configure U-Boot to use a real shell (hush)
5294 as command interpreter.
5296 Booting the Linux zImage:
5297 -------------------------
5299 On some platforms, it's possible to boot Linux zImage. This is done
5300 using the "bootz" command. The syntax of "bootz" command is the same
5301 as the syntax of "bootm" command.
5303 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5304 kernel with raw initrd images. The syntax is slightly different, the
5305 address of the initrd must be augmented by it's size, in the following
5306 format: "<initrd addres>:<initrd size>".
5312 One of the features of U-Boot is that you can dynamically load and
5313 run "standalone" applications, which can use some resources of
5314 U-Boot like console I/O functions or interrupt services.
5316 Two simple examples are included with the sources:
5321 'examples/hello_world.c' contains a small "Hello World" Demo
5322 application; it is automatically compiled when you build U-Boot.
5323 It's configured to run at address 0x00040004, so you can play with it
5327 ## Ready for S-Record download ...
5328 ~>examples/hello_world.srec
5329 1 2 3 4 5 6 7 8 9 10 11 ...
5330 [file transfer complete]
5332 ## Start Addr = 0x00040004
5334 => go 40004 Hello World! This is a test.
5335 ## Starting application at 0x00040004 ...
5346 Hit any key to exit ...
5348 ## Application terminated, rc = 0x0
5350 Another example, which demonstrates how to register a CPM interrupt
5351 handler with the U-Boot code, can be found in 'examples/timer.c'.
5352 Here, a CPM timer is set up to generate an interrupt every second.
5353 The interrupt service routine is trivial, just printing a '.'
5354 character, but this is just a demo program. The application can be
5355 controlled by the following keys:
5357 ? - print current values og the CPM Timer registers
5358 b - enable interrupts and start timer
5359 e - stop timer and disable interrupts
5360 q - quit application
5363 ## Ready for S-Record download ...
5364 ~>examples/timer.srec
5365 1 2 3 4 5 6 7 8 9 10 11 ...
5366 [file transfer complete]
5368 ## Start Addr = 0x00040004
5371 ## Starting application at 0x00040004 ...
5374 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5377 [q, b, e, ?] Set interval 1000000 us
5380 [q, b, e, ?] ........
5381 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5384 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5387 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5390 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5392 [q, b, e, ?] ...Stopping timer
5394 [q, b, e, ?] ## Application terminated, rc = 0x0
5400 Over time, many people have reported problems when trying to use the
5401 "minicom" terminal emulation program for serial download. I (wd)
5402 consider minicom to be broken, and recommend not to use it. Under
5403 Unix, I recommend to use C-Kermit for general purpose use (and
5404 especially for kermit binary protocol download ("loadb" command), and
5405 use "cu" for S-Record download ("loads" command). See
5406 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5407 for help with kermit.
5410 Nevertheless, if you absolutely want to use it try adding this
5411 configuration to your "File transfer protocols" section:
5413 Name Program Name U/D FullScr IO-Red. Multi
5414 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5415 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5421 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5422 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5424 Building requires a cross environment; it is known to work on
5425 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5426 need gmake since the Makefiles are not compatible with BSD make).
5427 Note that the cross-powerpc package does not install include files;
5428 attempting to build U-Boot will fail because <machine/ansi.h> is
5429 missing. This file has to be installed and patched manually:
5431 # cd /usr/pkg/cross/powerpc-netbsd/include
5433 # ln -s powerpc machine
5434 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5435 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5437 Native builds *don't* work due to incompatibilities between native
5438 and U-Boot include files.
5440 Booting assumes that (the first part of) the image booted is a
5441 stage-2 loader which in turn loads and then invokes the kernel
5442 proper. Loader sources will eventually appear in the NetBSD source
5443 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5444 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5447 Implementation Internals:
5448 =========================
5450 The following is not intended to be a complete description of every
5451 implementation detail. However, it should help to understand the
5452 inner workings of U-Boot and make it easier to port it to custom
5456 Initial Stack, Global Data:
5457 ---------------------------
5459 The implementation of U-Boot is complicated by the fact that U-Boot
5460 starts running out of ROM (flash memory), usually without access to
5461 system RAM (because the memory controller is not initialized yet).
5462 This means that we don't have writable Data or BSS segments, and BSS
5463 is not initialized as zero. To be able to get a C environment working
5464 at all, we have to allocate at least a minimal stack. Implementation
5465 options for this are defined and restricted by the CPU used: Some CPU
5466 models provide on-chip memory (like the IMMR area on MPC8xx and
5467 MPC826x processors), on others (parts of) the data cache can be
5468 locked as (mis-) used as memory, etc.
5470 Chris Hallinan posted a good summary of these issues to the
5471 U-Boot mailing list:
5473 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5474 From: "Chris Hallinan" <clh@net1plus.com>
5475 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5478 Correct me if I'm wrong, folks, but the way I understand it
5479 is this: Using DCACHE as initial RAM for Stack, etc, does not
5480 require any physical RAM backing up the cache. The cleverness
5481 is that the cache is being used as a temporary supply of
5482 necessary storage before the SDRAM controller is setup. It's
5483 beyond the scope of this list to explain the details, but you
5484 can see how this works by studying the cache architecture and
5485 operation in the architecture and processor-specific manuals.
5487 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5488 is another option for the system designer to use as an
5489 initial stack/RAM area prior to SDRAM being available. Either
5490 option should work for you. Using CS 4 should be fine if your
5491 board designers haven't used it for something that would
5492 cause you grief during the initial boot! It is frequently not
5495 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5496 with your processor/board/system design. The default value
5497 you will find in any recent u-boot distribution in
5498 walnut.h should work for you. I'd set it to a value larger
5499 than your SDRAM module. If you have a 64MB SDRAM module, set
5500 it above 400_0000. Just make sure your board has no resources
5501 that are supposed to respond to that address! That code in
5502 start.S has been around a while and should work as is when
5503 you get the config right.
5508 It is essential to remember this, since it has some impact on the C
5509 code for the initialization procedures:
5511 * Initialized global data (data segment) is read-only. Do not attempt
5514 * Do not use any uninitialized global data (or implicitely initialized
5515 as zero data - BSS segment) at all - this is undefined, initiali-
5516 zation is performed later (when relocating to RAM).
5518 * Stack space is very limited. Avoid big data buffers or things like
5521 Having only the stack as writable memory limits means we cannot use
5522 normal global data to share information beween the code. But it
5523 turned out that the implementation of U-Boot can be greatly
5524 simplified by making a global data structure (gd_t) available to all
5525 functions. We could pass a pointer to this data as argument to _all_
5526 functions, but this would bloat the code. Instead we use a feature of
5527 the GCC compiler (Global Register Variables) to share the data: we
5528 place a pointer (gd) to the global data into a register which we
5529 reserve for this purpose.
5531 When choosing a register for such a purpose we are restricted by the
5532 relevant (E)ABI specifications for the current architecture, and by
5533 GCC's implementation.
5535 For PowerPC, the following registers have specific use:
5537 R2: reserved for system use
5538 R3-R4: parameter passing and return values
5539 R5-R10: parameter passing
5540 R13: small data area pointer
5544 (U-Boot also uses R12 as internal GOT pointer. r12
5545 is a volatile register so r12 needs to be reset when
5546 going back and forth between asm and C)
5548 ==> U-Boot will use R2 to hold a pointer to the global data
5550 Note: on PPC, we could use a static initializer (since the
5551 address of the global data structure is known at compile time),
5552 but it turned out that reserving a register results in somewhat
5553 smaller code - although the code savings are not that big (on
5554 average for all boards 752 bytes for the whole U-Boot image,
5555 624 text + 127 data).
5557 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5558 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5560 ==> U-Boot will use P3 to hold a pointer to the global data
5562 On ARM, the following registers are used:
5564 R0: function argument word/integer result
5565 R1-R3: function argument word
5567 R10: stack limit (used only if stack checking if enabled)
5568 R11: argument (frame) pointer
5569 R12: temporary workspace
5572 R15: program counter
5574 ==> U-Boot will use R8 to hold a pointer to the global data
5576 On Nios II, the ABI is documented here:
5577 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5579 ==> U-Boot will use gp to hold a pointer to the global data
5581 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5582 to access small data sections, so gp is free.
5584 On NDS32, the following registers are used:
5586 R0-R1: argument/return
5588 R15: temporary register for assembler
5589 R16: trampoline register
5590 R28: frame pointer (FP)
5591 R29: global pointer (GP)
5592 R30: link register (LP)
5593 R31: stack pointer (SP)
5594 PC: program counter (PC)
5596 ==> U-Boot will use R10 to hold a pointer to the global data
5598 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5599 or current versions of GCC may "optimize" the code too much.
5604 U-Boot runs in system state and uses physical addresses, i.e. the
5605 MMU is not used either for address mapping nor for memory protection.
5607 The available memory is mapped to fixed addresses using the memory
5608 controller. In this process, a contiguous block is formed for each
5609 memory type (Flash, SDRAM, SRAM), even when it consists of several
5610 physical memory banks.
5612 U-Boot is installed in the first 128 kB of the first Flash bank (on
5613 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5614 booting and sizing and initializing DRAM, the code relocates itself
5615 to the upper end of DRAM. Immediately below the U-Boot code some
5616 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5617 configuration setting]. Below that, a structure with global Board
5618 Info data is placed, followed by the stack (growing downward).
5620 Additionally, some exception handler code is copied to the low 8 kB
5621 of DRAM (0x00000000 ... 0x00001FFF).
5623 So a typical memory configuration with 16 MB of DRAM could look like
5626 0x0000 0000 Exception Vector code
5629 0x0000 2000 Free for Application Use
5635 0x00FB FF20 Monitor Stack (Growing downward)
5636 0x00FB FFAC Board Info Data and permanent copy of global data
5637 0x00FC 0000 Malloc Arena
5640 0x00FE 0000 RAM Copy of Monitor Code
5641 ... eventually: LCD or video framebuffer
5642 ... eventually: pRAM (Protected RAM - unchanged by reset)
5643 0x00FF FFFF [End of RAM]
5646 System Initialization:
5647 ----------------------
5649 In the reset configuration, U-Boot starts at the reset entry point
5650 (on most PowerPC systems at address 0x00000100). Because of the reset
5651 configuration for CS0# this is a mirror of the onboard Flash memory.
5652 To be able to re-map memory U-Boot then jumps to its link address.
5653 To be able to implement the initialization code in C, a (small!)
5654 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5655 which provide such a feature like MPC8xx or MPC8260), or in a locked
5656 part of the data cache. After that, U-Boot initializes the CPU core,
5657 the caches and the SIU.
5659 Next, all (potentially) available memory banks are mapped using a
5660 preliminary mapping. For example, we put them on 512 MB boundaries
5661 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5662 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5663 programmed for SDRAM access. Using the temporary configuration, a
5664 simple memory test is run that determines the size of the SDRAM
5667 When there is more than one SDRAM bank, and the banks are of
5668 different size, the largest is mapped first. For equal size, the first
5669 bank (CS2#) is mapped first. The first mapping is always for address
5670 0x00000000, with any additional banks following immediately to create
5671 contiguous memory starting from 0.
5673 Then, the monitor installs itself at the upper end of the SDRAM area
5674 and allocates memory for use by malloc() and for the global Board
5675 Info data; also, the exception vector code is copied to the low RAM
5676 pages, and the final stack is set up.
5678 Only after this relocation will you have a "normal" C environment;
5679 until that you are restricted in several ways, mostly because you are
5680 running from ROM, and because the code will have to be relocated to a
5684 U-Boot Porting Guide:
5685 ----------------------
5687 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5691 int main(int argc, char *argv[])
5693 sighandler_t no_more_time;
5695 signal(SIGALRM, no_more_time);
5696 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5698 if (available_money > available_manpower) {
5699 Pay consultant to port U-Boot;
5703 Download latest U-Boot source;
5705 Subscribe to u-boot mailing list;
5708 email("Hi, I am new to U-Boot, how do I get started?");
5711 Read the README file in the top level directory;
5712 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5713 Read applicable doc/*.README;
5714 Read the source, Luke;
5715 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5718 if (available_money > toLocalCurrency ($2500))
5721 Add a lot of aggravation and time;
5723 if (a similar board exists) { /* hopefully... */
5724 cp -a board/<similar> board/<myboard>
5725 cp include/configs/<similar>.h include/configs/<myboard>.h
5727 Create your own board support subdirectory;
5728 Create your own board include/configs/<myboard>.h file;
5730 Edit new board/<myboard> files
5731 Edit new include/configs/<myboard>.h
5736 Add / modify source code;
5740 email("Hi, I am having problems...");
5742 Send patch file to the U-Boot email list;
5743 if (reasonable critiques)
5744 Incorporate improvements from email list code review;
5746 Defend code as written;
5752 void no_more_time (int sig)
5761 All contributions to U-Boot should conform to the Linux kernel
5762 coding style; see the file "Documentation/CodingStyle" and the script
5763 "scripts/Lindent" in your Linux kernel source directory.
5765 Source files originating from a different project (for example the
5766 MTD subsystem) are generally exempt from these guidelines and are not
5767 reformated to ease subsequent migration to newer versions of those
5770 Please note that U-Boot is implemented in C (and to some small parts in
5771 Assembler); no C++ is used, so please do not use C++ style comments (//)
5774 Please also stick to the following formatting rules:
5775 - remove any trailing white space
5776 - use TAB characters for indentation and vertical alignment, not spaces
5777 - make sure NOT to use DOS '\r\n' line feeds
5778 - do not add more than 2 consecutive empty lines to source files
5779 - do not add trailing empty lines to source files
5781 Submissions which do not conform to the standards may be returned
5782 with a request to reformat the changes.
5788 Since the number of patches for U-Boot is growing, we need to
5789 establish some rules. Submissions which do not conform to these rules
5790 may be rejected, even when they contain important and valuable stuff.
5792 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5794 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5795 see http://lists.denx.de/mailman/listinfo/u-boot
5797 When you send a patch, please include the following information with
5800 * For bug fixes: a description of the bug and how your patch fixes
5801 this bug. Please try to include a way of demonstrating that the
5802 patch actually fixes something.
5804 * For new features: a description of the feature and your
5807 * A CHANGELOG entry as plaintext (separate from the patch)
5809 * For major contributions, your entry to the CREDITS file
5811 * When you add support for a new board, don't forget to add this
5812 board to the MAINTAINERS file, too.
5814 * If your patch adds new configuration options, don't forget to
5815 document these in the README file.
5817 * The patch itself. If you are using git (which is *strongly*
5818 recommended) you can easily generate the patch using the
5819 "git format-patch". If you then use "git send-email" to send it to
5820 the U-Boot mailing list, you will avoid most of the common problems
5821 with some other mail clients.
5823 If you cannot use git, use "diff -purN OLD NEW". If your version of
5824 diff does not support these options, then get the latest version of
5827 The current directory when running this command shall be the parent
5828 directory of the U-Boot source tree (i. e. please make sure that
5829 your patch includes sufficient directory information for the
5832 We prefer patches as plain text. MIME attachments are discouraged,
5833 and compressed attachments must not be used.
5835 * If one logical set of modifications affects or creates several
5836 files, all these changes shall be submitted in a SINGLE patch file.
5838 * Changesets that contain different, unrelated modifications shall be
5839 submitted as SEPARATE patches, one patch per changeset.
5844 * Before sending the patch, run the MAKEALL script on your patched
5845 source tree and make sure that no errors or warnings are reported
5846 for any of the boards.
5848 * Keep your modifications to the necessary minimum: A patch
5849 containing several unrelated changes or arbitrary reformats will be
5850 returned with a request to re-formatting / split it.
5852 * If you modify existing code, make sure that your new code does not
5853 add to the memory footprint of the code ;-) Small is beautiful!
5854 When adding new features, these should compile conditionally only
5855 (using #ifdef), and the resulting code with the new feature
5856 disabled must not need more memory than the old code without your
5859 * Remember that there is a size limit of 100 kB per message on the
5860 u-boot mailing list. Bigger patches will be moderated. If they are
5861 reasonable and not too big, they will be acknowledged. But patches
5862 bigger than the size limit should be avoided.
projects / kernel / u-boot.git / blob