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_M2_RAM_ADDR
410 This value denotes start offset of M2 memory
411 which is directly connected to the DSP core.
413 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
414 This value denotes start offset of DSP CCSR space.
416 - Generic CPU options:
417 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
419 Defines the endianess of the CPU. Implementation of those
420 values is arch specific.
422 - Intel Monahans options:
423 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
425 Defines the Monahans run mode to oscillator
426 ratio. Valid values are 8, 16, 24, 31. The core
427 frequency is this value multiplied by 13 MHz.
429 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
431 Defines the Monahans turbo mode to oscillator
432 ratio. Valid values are 1 (default if undefined) and
433 2. The core frequency as calculated above is multiplied
437 CONFIG_SYS_INIT_SP_OFFSET
439 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
440 pointer. This is needed for the temporary stack before
443 CONFIG_SYS_MIPS_CACHE_MODE
445 Cache operation mode for the MIPS CPU.
446 See also arch/mips/include/asm/mipsregs.h.
448 CONF_CM_CACHABLE_NO_WA
451 CONF_CM_CACHABLE_NONCOHERENT
455 CONF_CM_CACHABLE_ACCELERATED
457 CONFIG_SYS_XWAY_EBU_BOOTCFG
459 Special option for Lantiq XWAY SoCs for booting from NOR flash.
460 See also arch/mips/cpu/mips32/start.S.
462 CONFIG_XWAY_SWAP_BYTES
464 Enable compilation of tools/xway-swap-bytes needed for Lantiq
465 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
466 be swapped if a flash programmer is used.
469 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
471 Select high exception vectors of the ARM core, e.g., do not
472 clear the V bit of the c1 register of CP15.
474 CONFIG_SYS_THUMB_BUILD
476 Use this flag to build U-Boot using the Thumb instruction
477 set for ARM architectures. Thumb instruction set provides
478 better code density. For ARM architectures that support
479 Thumb2 this flag will result in Thumb2 code generated by
482 CONFIG_ARM_ERRATA_716044
483 CONFIG_ARM_ERRATA_742230
484 CONFIG_ARM_ERRATA_743622
485 CONFIG_ARM_ERRATA_751472
487 If set, the workarounds for these ARM errata are applied early
488 during U-Boot startup. Note that these options force the
489 workarounds to be applied; no CPU-type/version detection
490 exists, unlike the similar options in the Linux kernel. Do not
491 set these options unless they apply!
496 The frequency of the timer returned by get_timer().
497 get_timer() must operate in milliseconds and this CONFIG
498 option must be set to 1000.
500 - Linux Kernel Interface:
503 U-Boot stores all clock information in Hz
504 internally. For binary compatibility with older Linux
505 kernels (which expect the clocks passed in the
506 bd_info data to be in MHz) the environment variable
507 "clocks_in_mhz" can be defined so that U-Boot
508 converts clock data to MHZ before passing it to the
510 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
511 "clocks_in_mhz=1" is automatically included in the
514 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
516 When transferring memsize parameter to linux, some versions
517 expect it to be in bytes, others in MB.
518 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
522 New kernel versions are expecting firmware settings to be
523 passed using flattened device trees (based on open firmware
527 * New libfdt-based support
528 * Adds the "fdt" command
529 * The bootm command automatically updates the fdt
531 OF_CPU - The proper name of the cpus node (only required for
532 MPC512X and MPC5xxx based boards).
533 OF_SOC - The proper name of the soc node (only required for
534 MPC512X and MPC5xxx based boards).
535 OF_TBCLK - The timebase frequency.
536 OF_STDOUT_PATH - The path to the console device
538 boards with QUICC Engines require OF_QE to set UCC MAC
541 CONFIG_OF_BOARD_SETUP
543 Board code has addition modification that it wants to make
544 to the flat device tree before handing it off to the kernel
548 This define fills in the correct boot CPU in the boot
549 param header, the default value is zero if undefined.
553 U-Boot can detect if an IDE device is present or not.
554 If not, and this new config option is activated, U-Boot
555 removes the ATA node from the DTS before booting Linux,
556 so the Linux IDE driver does not probe the device and
557 crash. This is needed for buggy hardware (uc101) where
558 no pull down resistor is connected to the signal IDE5V_DD7.
560 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
562 This setting is mandatory for all boards that have only one
563 machine type and must be used to specify the machine type
564 number as it appears in the ARM machine registry
565 (see http://www.arm.linux.org.uk/developer/machines/).
566 Only boards that have multiple machine types supported
567 in a single configuration file and the machine type is
568 runtime discoverable, do not have to use this setting.
570 - vxWorks boot parameters:
572 bootvx constructs a valid bootline using the following
573 environments variables: bootfile, ipaddr, serverip, hostname.
574 It loads the vxWorks image pointed bootfile.
576 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
577 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
578 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
579 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
581 CONFIG_SYS_VXWORKS_ADD_PARAMS
583 Add it at the end of the bootline. E.g "u=username pw=secret"
585 Note: If a "bootargs" environment is defined, it will overwride
586 the defaults discussed just above.
588 - Cache Configuration:
589 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
590 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
591 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
593 - Cache Configuration for ARM:
594 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
596 CONFIG_SYS_PL310_BASE - Physical base address of PL310
597 controller register space
602 Define this if you want support for Amba PrimeCell PL010 UARTs.
606 Define this if you want support for Amba PrimeCell PL011 UARTs.
610 If you have Amba PrimeCell PL011 UARTs, set this variable to
611 the clock speed of the UARTs.
615 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
616 define this to a list of base addresses for each (supported)
617 port. See e.g. include/configs/versatile.h
619 CONFIG_PL011_SERIAL_RLCR
621 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
622 have separate receive and transmit line control registers. Set
623 this variable to initialize the extra register.
625 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
627 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
628 boot loader that has already initialized the UART. Define this
629 variable to flush the UART at init time.
633 Depending on board, define exactly one serial port
634 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
635 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
636 console by defining CONFIG_8xx_CONS_NONE
638 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
639 port routines must be defined elsewhere
640 (i.e. serial_init(), serial_getc(), ...)
643 Enables console device for a color framebuffer. Needs following
644 defines (cf. smiLynxEM, i8042)
645 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
647 VIDEO_HW_RECTFILL graphic chip supports
650 VIDEO_HW_BITBLT graphic chip supports
651 bit-blit (cf. smiLynxEM)
652 VIDEO_VISIBLE_COLS visible pixel columns
654 VIDEO_VISIBLE_ROWS visible pixel rows
655 VIDEO_PIXEL_SIZE bytes per pixel
656 VIDEO_DATA_FORMAT graphic data format
657 (0-5, cf. cfb_console.c)
658 VIDEO_FB_ADRS framebuffer address
659 VIDEO_KBD_INIT_FCT keyboard int fct
660 (i.e. i8042_kbd_init())
661 VIDEO_TSTC_FCT test char fct
663 VIDEO_GETC_FCT get char fct
665 CONFIG_CONSOLE_CURSOR cursor drawing on/off
666 (requires blink timer
668 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
669 CONFIG_CONSOLE_TIME display time/date info in
671 (requires CONFIG_CMD_DATE)
672 CONFIG_VIDEO_LOGO display Linux logo in
674 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
675 linux_logo.h for logo.
676 Requires CONFIG_VIDEO_LOGO
677 CONFIG_CONSOLE_EXTRA_INFO
678 additional board info beside
681 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
682 a limited number of ANSI escape sequences (cursor control,
683 erase functions and limited graphics rendition control).
685 When CONFIG_CFB_CONSOLE is defined, video console is
686 default i/o. Serial console can be forced with
687 environment 'console=serial'.
689 When CONFIG_SILENT_CONSOLE is defined, all console
690 messages (by U-Boot and Linux!) can be silenced with
691 the "silent" environment variable. See
692 doc/README.silent for more information.
695 CONFIG_BAUDRATE - in bps
696 Select one of the baudrates listed in
697 CONFIG_SYS_BAUDRATE_TABLE, see below.
698 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
700 - Console Rx buffer length
701 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
702 the maximum receive buffer length for the SMC.
703 This option is actual only for 82xx and 8xx possible.
704 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
705 must be defined, to setup the maximum idle timeout for
708 - Pre-Console Buffer:
709 Prior to the console being initialised (i.e. serial UART
710 initialised etc) all console output is silently discarded.
711 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
712 buffer any console messages prior to the console being
713 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
714 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
715 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
716 bytes are output before the console is initialised, the
717 earlier bytes are discarded.
719 'Sane' compilers will generate smaller code if
720 CONFIG_PRE_CON_BUF_SZ is a power of 2
722 - Safe printf() functions
723 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
724 the printf() functions. These are defined in
725 include/vsprintf.h and include snprintf(), vsnprintf() and
726 so on. Code size increase is approximately 300-500 bytes.
727 If this option is not given then these functions will
728 silently discard their buffer size argument - this means
729 you are not getting any overflow checking in this case.
731 - Boot Delay: CONFIG_BOOTDELAY - in seconds
732 Delay before automatically booting the default image;
733 set to -1 to disable autoboot.
734 set to -2 to autoboot with no delay and not check for abort
735 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
737 See doc/README.autoboot for these options that
738 work with CONFIG_BOOTDELAY. None are required.
739 CONFIG_BOOT_RETRY_TIME
740 CONFIG_BOOT_RETRY_MIN
741 CONFIG_AUTOBOOT_KEYED
742 CONFIG_AUTOBOOT_PROMPT
743 CONFIG_AUTOBOOT_DELAY_STR
744 CONFIG_AUTOBOOT_STOP_STR
745 CONFIG_AUTOBOOT_DELAY_STR2
746 CONFIG_AUTOBOOT_STOP_STR2
747 CONFIG_ZERO_BOOTDELAY_CHECK
748 CONFIG_RESET_TO_RETRY
752 Only needed when CONFIG_BOOTDELAY is enabled;
753 define a command string that is automatically executed
754 when no character is read on the console interface
755 within "Boot Delay" after reset.
758 This can be used to pass arguments to the bootm
759 command. The value of CONFIG_BOOTARGS goes into the
760 environment value "bootargs".
762 CONFIG_RAMBOOT and CONFIG_NFSBOOT
763 The value of these goes into the environment as
764 "ramboot" and "nfsboot" respectively, and can be used
765 as a convenience, when switching between booting from
771 When this option is #defined, the existence of the
772 environment variable "preboot" will be checked
773 immediately before starting the CONFIG_BOOTDELAY
774 countdown and/or running the auto-boot command resp.
775 entering interactive mode.
777 This feature is especially useful when "preboot" is
778 automatically generated or modified. For an example
779 see the LWMON board specific code: here "preboot" is
780 modified when the user holds down a certain
781 combination of keys on the (special) keyboard when
784 - Serial Download Echo Mode:
786 If defined to 1, all characters received during a
787 serial download (using the "loads" command) are
788 echoed back. This might be needed by some terminal
789 emulations (like "cu"), but may as well just take
790 time on others. This setting #define's the initial
791 value of the "loads_echo" environment variable.
793 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
795 Select one of the baudrates listed in
796 CONFIG_SYS_BAUDRATE_TABLE, see below.
799 Monitor commands can be included or excluded
800 from the build by using the #include files
801 <config_cmd_all.h> and #undef'ing unwanted
802 commands, or using <config_cmd_default.h>
803 and augmenting with additional #define's
806 The default command configuration includes all commands
807 except those marked below with a "*".
809 CONFIG_CMD_ASKENV * ask for env variable
810 CONFIG_CMD_BDI bdinfo
811 CONFIG_CMD_BEDBUG * Include BedBug Debugger
812 CONFIG_CMD_BMP * BMP support
813 CONFIG_CMD_BSP * Board specific commands
814 CONFIG_CMD_BOOTD bootd
815 CONFIG_CMD_CACHE * icache, dcache
816 CONFIG_CMD_CONSOLE coninfo
817 CONFIG_CMD_CRC32 * crc32
818 CONFIG_CMD_DATE * support for RTC, date/time...
819 CONFIG_CMD_DHCP * DHCP support
820 CONFIG_CMD_DIAG * Diagnostics
821 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
822 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
823 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
824 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
825 CONFIG_CMD_DTT * Digital Therm and Thermostat
826 CONFIG_CMD_ECHO echo arguments
827 CONFIG_CMD_EDITENV edit env variable
828 CONFIG_CMD_EEPROM * EEPROM read/write support
829 CONFIG_CMD_ELF * bootelf, bootvx
830 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
831 CONFIG_CMD_ENV_FLAGS * display details about env flags
832 CONFIG_CMD_EXPORTENV * export the environment
833 CONFIG_CMD_EXT2 * ext2 command support
834 CONFIG_CMD_EXT4 * ext4 command support
835 CONFIG_CMD_SAVEENV saveenv
836 CONFIG_CMD_FDC * Floppy Disk Support
837 CONFIG_CMD_FAT * FAT command support
838 CONFIG_CMD_FDOS * Dos diskette Support
839 CONFIG_CMD_FLASH flinfo, erase, protect
840 CONFIG_CMD_FPGA FPGA device initialization support
841 CONFIG_CMD_FUSE * Device fuse support
842 CONFIG_CMD_GETTIME * Get time since boot
843 CONFIG_CMD_GO * the 'go' command (exec code)
844 CONFIG_CMD_GREPENV * search environment
845 CONFIG_CMD_HASH * calculate hash / digest
846 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
847 CONFIG_CMD_I2C * I2C serial bus support
848 CONFIG_CMD_IDE * IDE harddisk support
849 CONFIG_CMD_IMI iminfo
850 CONFIG_CMD_IMLS List all images found in NOR flash
851 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
852 CONFIG_CMD_IMMAP * IMMR dump support
853 CONFIG_CMD_IMPORTENV * import an environment
854 CONFIG_CMD_INI * import data from an ini file into the env
855 CONFIG_CMD_IRQ * irqinfo
856 CONFIG_CMD_ITEST Integer/string test of 2 values
857 CONFIG_CMD_JFFS2 * JFFS2 Support
858 CONFIG_CMD_KGDB * kgdb
859 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
860 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
862 CONFIG_CMD_LOADB loadb
863 CONFIG_CMD_LOADS loads
864 CONFIG_CMD_MD5SUM * print md5 message digest
865 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
866 CONFIG_CMD_MEMINFO * Display detailed memory information
867 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
869 CONFIG_CMD_MEMTEST * mtest
870 CONFIG_CMD_MISC Misc functions like sleep etc
871 CONFIG_CMD_MMC * MMC memory mapped support
872 CONFIG_CMD_MII * MII utility commands
873 CONFIG_CMD_MTDPARTS * MTD partition support
874 CONFIG_CMD_NAND * NAND support
875 CONFIG_CMD_NET bootp, tftpboot, rarpboot
876 CONFIG_CMD_NFS NFS support
877 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
878 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
879 CONFIG_CMD_PCI * pciinfo
880 CONFIG_CMD_PCMCIA * PCMCIA support
881 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
883 CONFIG_CMD_PORTIO * Port I/O
884 CONFIG_CMD_READ * Read raw data from partition
885 CONFIG_CMD_REGINFO * Register dump
886 CONFIG_CMD_RUN run command in env variable
887 CONFIG_CMD_SANDBOX * sb command to access sandbox features
888 CONFIG_CMD_SAVES * save S record dump
889 CONFIG_CMD_SCSI * SCSI Support
890 CONFIG_CMD_SDRAM * print SDRAM configuration information
891 (requires CONFIG_CMD_I2C)
892 CONFIG_CMD_SETGETDCR Support for DCR Register access
894 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
895 CONFIG_CMD_SHA1SUM * print sha1 memory digest
896 (requires CONFIG_CMD_MEMORY)
897 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
898 CONFIG_CMD_SOURCE "source" command Support
899 CONFIG_CMD_SPI * SPI serial bus support
900 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
901 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
902 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
903 CONFIG_CMD_TIMER * access to the system tick timer
904 CONFIG_CMD_USB * USB support
905 CONFIG_CMD_CDP * Cisco Discover Protocol support
906 CONFIG_CMD_MFSL * Microblaze FSL support
907 CONFIG_CMD_XIMG Load part of Multi Image
910 EXAMPLE: If you want all functions except of network
911 support you can write:
913 #include "config_cmd_all.h"
914 #undef CONFIG_CMD_NET
917 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
919 Note: Don't enable the "icache" and "dcache" commands
920 (configuration option CONFIG_CMD_CACHE) unless you know
921 what you (and your U-Boot users) are doing. Data
922 cache cannot be enabled on systems like the 8xx or
923 8260 (where accesses to the IMMR region must be
924 uncached), and it cannot be disabled on all other
925 systems where we (mis-) use the data cache to hold an
926 initial stack and some data.
929 XXX - this list needs to get updated!
931 - Regular expression support:
933 If this variable is defined, U-Boot is linked against
934 the SLRE (Super Light Regular Expression) library,
935 which adds regex support to some commands, as for
936 example "env grep" and "setexpr".
940 If this variable is defined, U-Boot will use a device tree
941 to configure its devices, instead of relying on statically
942 compiled #defines in the board file. This option is
943 experimental and only available on a few boards. The device
944 tree is available in the global data as gd->fdt_blob.
946 U-Boot needs to get its device tree from somewhere. This can
947 be done using one of the two options below:
950 If this variable is defined, U-Boot will embed a device tree
951 binary in its image. This device tree file should be in the
952 board directory and called <soc>-<board>.dts. The binary file
953 is then picked up in board_init_f() and made available through
954 the global data structure as gd->blob.
957 If this variable is defined, U-Boot will build a device tree
958 binary. It will be called u-boot.dtb. Architecture-specific
959 code will locate it at run-time. Generally this works by:
961 cat u-boot.bin u-boot.dtb >image.bin
963 and in fact, U-Boot does this for you, creating a file called
964 u-boot-dtb.bin which is useful in the common case. You can
965 still use the individual files if you need something more
970 If this variable is defined, it enables watchdog
971 support for the SoC. There must be support in the SoC
972 specific code for a watchdog. For the 8xx and 8260
973 CPUs, the SIU Watchdog feature is enabled in the SYPCR
974 register. When supported for a specific SoC is
975 available, then no further board specific code should
979 When using a watchdog circuitry external to the used
980 SoC, then define this variable and provide board
981 specific code for the "hw_watchdog_reset" function.
984 CONFIG_VERSION_VARIABLE
985 If this variable is defined, an environment variable
986 named "ver" is created by U-Boot showing the U-Boot
987 version as printed by the "version" command.
988 Any change to this variable will be reverted at the
993 When CONFIG_CMD_DATE is selected, the type of the RTC
994 has to be selected, too. Define exactly one of the
997 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
998 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
999 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1000 CONFIG_RTC_MC146818 - use MC146818 RTC
1001 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1002 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1003 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1004 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1005 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1006 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1007 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1008 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1011 Note that if the RTC uses I2C, then the I2C interface
1012 must also be configured. See I2C Support, below.
1015 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1016 CONFIG_PCA953X_INFO - enable pca953x info command
1018 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1019 chip-ngpio pairs that tell the PCA953X driver the number of
1020 pins supported by a particular chip.
1022 Note that if the GPIO device uses I2C, then the I2C interface
1023 must also be configured. See I2C Support, below.
1025 - Timestamp Support:
1027 When CONFIG_TIMESTAMP is selected, the timestamp
1028 (date and time) of an image is printed by image
1029 commands like bootm or iminfo. This option is
1030 automatically enabled when you select CONFIG_CMD_DATE .
1032 - Partition Labels (disklabels) Supported:
1033 Zero or more of the following:
1034 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1035 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1036 Intel architecture, USB sticks, etc.
1037 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1038 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1039 bootloader. Note 2TB partition limit; see
1041 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1043 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1044 CONFIG_CMD_SCSI) you must configure support for at
1045 least one non-MTD partition type as well.
1048 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1049 board configurations files but used nowhere!
1051 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1052 be performed by calling the function
1053 ide_set_reset(int reset)
1054 which has to be defined in a board specific file
1059 Set this to enable ATAPI support.
1064 Set this to enable support for disks larger than 137GB
1065 Also look at CONFIG_SYS_64BIT_LBA.
1066 Whithout these , LBA48 support uses 32bit variables and will 'only'
1067 support disks up to 2.1TB.
1069 CONFIG_SYS_64BIT_LBA:
1070 When enabled, makes the IDE subsystem use 64bit sector addresses.
1074 At the moment only there is only support for the
1075 SYM53C8XX SCSI controller; define
1076 CONFIG_SCSI_SYM53C8XX to enable it.
1078 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1079 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1080 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1081 maximum numbers of LUNs, SCSI ID's and target
1083 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1085 The environment variable 'scsidevs' is set to the number of
1086 SCSI devices found during the last scan.
1088 - NETWORK Support (PCI):
1090 Support for Intel 8254x/8257x gigabit chips.
1093 Utility code for direct access to the SPI bus on Intel 8257x.
1094 This does not do anything useful unless you set at least one
1095 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1097 CONFIG_E1000_SPI_GENERIC
1098 Allow generic access to the SPI bus on the Intel 8257x, for
1099 example with the "sspi" command.
1102 Management command for E1000 devices. When used on devices
1103 with SPI support you can reprogram the EEPROM from U-Boot.
1105 CONFIG_E1000_FALLBACK_MAC
1106 default MAC for empty EEPROM after production.
1109 Support for Intel 82557/82559/82559ER chips.
1110 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1111 write routine for first time initialisation.
1114 Support for Digital 2114x chips.
1115 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1116 modem chip initialisation (KS8761/QS6611).
1119 Support for National dp83815 chips.
1122 Support for National dp8382[01] gigabit chips.
1124 - NETWORK Support (other):
1126 CONFIG_DRIVER_AT91EMAC
1127 Support for AT91RM9200 EMAC.
1130 Define this to use reduced MII inteface
1132 CONFIG_DRIVER_AT91EMAC_QUIET
1133 If this defined, the driver is quiet.
1134 The driver doen't show link status messages.
1136 CONFIG_CALXEDA_XGMAC
1137 Support for the Calxeda XGMAC device
1140 Support for SMSC's LAN91C96 chips.
1142 CONFIG_LAN91C96_BASE
1143 Define this to hold the physical address
1144 of the LAN91C96's I/O space
1146 CONFIG_LAN91C96_USE_32_BIT
1147 Define this to enable 32 bit addressing
1150 Support for SMSC's LAN91C111 chip
1152 CONFIG_SMC91111_BASE
1153 Define this to hold the physical address
1154 of the device (I/O space)
1156 CONFIG_SMC_USE_32_BIT
1157 Define this if data bus is 32 bits
1159 CONFIG_SMC_USE_IOFUNCS
1160 Define this to use i/o functions instead of macros
1161 (some hardware wont work with macros)
1163 CONFIG_DRIVER_TI_EMAC
1164 Support for davinci emac
1166 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1167 Define this if you have more then 3 PHYs.
1170 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1172 CONFIG_FTGMAC100_EGIGA
1173 Define this to use GE link update with gigabit PHY.
1174 Define this if FTGMAC100 is connected to gigabit PHY.
1175 If your system has 10/100 PHY only, it might not occur
1176 wrong behavior. Because PHY usually return timeout or
1177 useless data when polling gigabit status and gigabit
1178 control registers. This behavior won't affect the
1179 correctnessof 10/100 link speed update.
1182 Support for SMSC's LAN911x and LAN921x chips
1185 Define this to hold the physical address
1186 of the device (I/O space)
1188 CONFIG_SMC911X_32_BIT
1189 Define this if data bus is 32 bits
1191 CONFIG_SMC911X_16_BIT
1192 Define this if data bus is 16 bits. If your processor
1193 automatically converts one 32 bit word to two 16 bit
1194 words you may also try CONFIG_SMC911X_32_BIT.
1197 Support for Renesas on-chip Ethernet controller
1199 CONFIG_SH_ETHER_USE_PORT
1200 Define the number of ports to be used
1202 CONFIG_SH_ETHER_PHY_ADDR
1203 Define the ETH PHY's address
1205 CONFIG_SH_ETHER_CACHE_WRITEBACK
1206 If this option is set, the driver enables cache flush.
1210 Support TPM devices.
1213 Support for i2c bus TPM devices. Only one device
1214 per system is supported at this time.
1216 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1217 Define the the i2c bus number for the TPM device
1219 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1220 Define the TPM's address on the i2c bus
1222 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1223 Define the burst count bytes upper limit
1225 CONFIG_TPM_ATMEL_TWI
1226 Support for Atmel TWI TPM device. Requires I2C support.
1229 Support for generic parallel port TPM devices. Only one device
1230 per system is supported at this time.
1232 CONFIG_TPM_TIS_BASE_ADDRESS
1233 Base address where the generic TPM device is mapped
1234 to. Contemporary x86 systems usually map it at
1238 Add tpm monitor functions.
1239 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1240 provides monitor access to authorized functions.
1243 Define this to enable the TPM support library which provides
1244 functional interfaces to some TPM commands.
1245 Requires support for a TPM device.
1247 CONFIG_TPM_AUTH_SESSIONS
1248 Define this to enable authorized functions in the TPM library.
1249 Requires CONFIG_TPM and CONFIG_SHA1.
1252 At the moment only the UHCI host controller is
1253 supported (PIP405, MIP405, MPC5200); define
1254 CONFIG_USB_UHCI to enable it.
1255 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1256 and define CONFIG_USB_STORAGE to enable the USB
1259 Supported are USB Keyboards and USB Floppy drives
1261 MPC5200 USB requires additional defines:
1263 for 528 MHz Clock: 0x0001bbbb
1267 for differential drivers: 0x00001000
1268 for single ended drivers: 0x00005000
1269 for differential drivers on PSC3: 0x00000100
1270 for single ended drivers on PSC3: 0x00004100
1271 CONFIG_SYS_USB_EVENT_POLL
1272 May be defined to allow interrupt polling
1273 instead of using asynchronous interrupts
1275 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1276 txfilltuning field in the EHCI controller on reset.
1278 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1279 interval for usb hub power-on delay.(minimum 100msec)
1282 Define the below if you wish to use the USB console.
1283 Once firmware is rebuilt from a serial console issue the
1284 command "setenv stdin usbtty; setenv stdout usbtty" and
1285 attach your USB cable. The Unix command "dmesg" should print
1286 it has found a new device. The environment variable usbtty
1287 can be set to gserial or cdc_acm to enable your device to
1288 appear to a USB host as a Linux gserial device or a
1289 Common Device Class Abstract Control Model serial device.
1290 If you select usbtty = gserial you should be able to enumerate
1292 # modprobe usbserial vendor=0xVendorID product=0xProductID
1293 else if using cdc_acm, simply setting the environment
1294 variable usbtty to be cdc_acm should suffice. The following
1295 might be defined in YourBoardName.h
1298 Define this to build a UDC device
1301 Define this to have a tty type of device available to
1302 talk to the UDC device
1305 Define this to enable the high speed support for usb
1306 device and usbtty. If this feature is enabled, a routine
1307 int is_usbd_high_speed(void)
1308 also needs to be defined by the driver to dynamically poll
1309 whether the enumeration has succeded at high speed or full
1312 CONFIG_SYS_CONSOLE_IS_IN_ENV
1313 Define this if you want stdin, stdout &/or stderr to
1317 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1318 Derive USB clock from external clock "blah"
1319 - CONFIG_SYS_USB_EXTC_CLK 0x02
1321 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1322 Derive USB clock from brgclk
1323 - CONFIG_SYS_USB_BRG_CLK 0x04
1325 If you have a USB-IF assigned VendorID then you may wish to
1326 define your own vendor specific values either in BoardName.h
1327 or directly in usbd_vendor_info.h. If you don't define
1328 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1329 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1330 should pretend to be a Linux device to it's target host.
1332 CONFIG_USBD_MANUFACTURER
1333 Define this string as the name of your company for
1334 - CONFIG_USBD_MANUFACTURER "my company"
1336 CONFIG_USBD_PRODUCT_NAME
1337 Define this string as the name of your product
1338 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1340 CONFIG_USBD_VENDORID
1341 Define this as your assigned Vendor ID from the USB
1342 Implementors Forum. This *must* be a genuine Vendor ID
1343 to avoid polluting the USB namespace.
1344 - CONFIG_USBD_VENDORID 0xFFFF
1346 CONFIG_USBD_PRODUCTID
1347 Define this as the unique Product ID
1349 - CONFIG_USBD_PRODUCTID 0xFFFF
1351 - ULPI Layer Support:
1352 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1353 the generic ULPI layer. The generic layer accesses the ULPI PHY
1354 via the platform viewport, so you need both the genric layer and
1355 the viewport enabled. Currently only Chipidea/ARC based
1356 viewport is supported.
1357 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1358 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1359 If your ULPI phy needs a different reference clock than the
1360 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1361 the appropriate value in Hz.
1364 The MMC controller on the Intel PXA is supported. To
1365 enable this define CONFIG_MMC. The MMC can be
1366 accessed from the boot prompt by mapping the device
1367 to physical memory similar to flash. Command line is
1368 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1369 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1372 Support for Renesas on-chip MMCIF controller
1374 CONFIG_SH_MMCIF_ADDR
1375 Define the base address of MMCIF registers
1378 Define the clock frequency for MMCIF
1380 - USB Device Firmware Update (DFU) class support:
1382 This enables the USB portion of the DFU USB class
1385 This enables the command "dfu" which is used to have
1386 U-Boot create a DFU class device via USB. This command
1387 requires that the "dfu_alt_info" environment variable be
1388 set and define the alt settings to expose to the host.
1391 This enables support for exposing (e)MMC devices via DFU.
1394 This enables support for exposing NAND devices via DFU.
1396 CONFIG_SYS_DFU_DATA_BUF_SIZE
1397 Dfu transfer uses a buffer before writing data to the
1398 raw storage device. Make the size (in bytes) of this buffer
1399 configurable. The size of this buffer is also configurable
1400 through the "dfu_bufsiz" environment variable.
1402 CONFIG_SYS_DFU_MAX_FILE_SIZE
1403 When updating files rather than the raw storage device,
1404 we use a static buffer to copy the file into and then write
1405 the buffer once we've been given the whole file. Define
1406 this to the maximum filesize (in bytes) for the buffer.
1407 Default is 4 MiB if undefined.
1409 - Journaling Flash filesystem support:
1410 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1411 CONFIG_JFFS2_NAND_DEV
1412 Define these for a default partition on a NAND device
1414 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1415 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1416 Define these for a default partition on a NOR device
1418 CONFIG_SYS_JFFS_CUSTOM_PART
1419 Define this to create an own partition. You have to provide a
1420 function struct part_info* jffs2_part_info(int part_num)
1422 If you define only one JFFS2 partition you may also want to
1423 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1424 to disable the command chpart. This is the default when you
1425 have not defined a custom partition
1427 - FAT(File Allocation Table) filesystem write function support:
1430 Define this to enable support for saving memory data as a
1431 file in FAT formatted partition.
1433 This will also enable the command "fatwrite" enabling the
1434 user to write files to FAT.
1436 CBFS (Coreboot Filesystem) support
1439 Define this to enable support for reading from a Coreboot
1440 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1446 Define this to enable standard (PC-Style) keyboard
1450 Standard PC keyboard driver with US (is default) and
1451 GERMAN key layout (switch via environment 'keymap=de') support.
1452 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1453 for cfb_console. Supports cursor blinking.
1456 Enables a Chrome OS keyboard using the CROS_EC interface.
1457 This uses CROS_EC to communicate with a second microcontroller
1458 which provides key scans on request.
1463 Define this to enable video support (for output to
1466 CONFIG_VIDEO_CT69000
1468 Enable Chips & Technologies 69000 Video chip
1470 CONFIG_VIDEO_SMI_LYNXEM
1471 Enable Silicon Motion SMI 712/710/810 Video chip. The
1472 video output is selected via environment 'videoout'
1473 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1476 For the CT69000 and SMI_LYNXEM drivers, videomode is
1477 selected via environment 'videomode'. Two different ways
1479 - "videomode=num" 'num' is a standard LiLo mode numbers.
1480 Following standard modes are supported (* is default):
1482 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1483 -------------+---------------------------------------------
1484 8 bits | 0x301* 0x303 0x305 0x161 0x307
1485 15 bits | 0x310 0x313 0x316 0x162 0x319
1486 16 bits | 0x311 0x314 0x317 0x163 0x31A
1487 24 bits | 0x312 0x315 0x318 ? 0x31B
1488 -------------+---------------------------------------------
1489 (i.e. setenv videomode 317; saveenv; reset;)
1491 - "videomode=bootargs" all the video parameters are parsed
1492 from the bootargs. (See drivers/video/videomodes.c)
1495 CONFIG_VIDEO_SED13806
1496 Enable Epson SED13806 driver. This driver supports 8bpp
1497 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1498 or CONFIG_VIDEO_SED13806_16BPP
1501 Enable the Freescale DIU video driver. Reference boards for
1502 SOCs that have a DIU should define this macro to enable DIU
1503 support, and should also define these other macros:
1509 CONFIG_VIDEO_SW_CURSOR
1510 CONFIG_VGA_AS_SINGLE_DEVICE
1512 CONFIG_VIDEO_BMP_LOGO
1514 The DIU driver will look for the 'video-mode' environment
1515 variable, and if defined, enable the DIU as a console during
1516 boot. See the documentation file README.video for a
1517 description of this variable.
1521 Enable the VGA video / BIOS for x86. The alternative if you
1522 are using coreboot is to use the coreboot frame buffer
1529 Define this to enable a custom keyboard support.
1530 This simply calls drv_keyboard_init() which must be
1531 defined in your board-specific files.
1532 The only board using this so far is RBC823.
1534 - LCD Support: CONFIG_LCD
1536 Define this to enable LCD support (for output to LCD
1537 display); also select one of the supported displays
1538 by defining one of these:
1542 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1544 CONFIG_NEC_NL6448AC33:
1546 NEC NL6448AC33-18. Active, color, single scan.
1548 CONFIG_NEC_NL6448BC20
1550 NEC NL6448BC20-08. 6.5", 640x480.
1551 Active, color, single scan.
1553 CONFIG_NEC_NL6448BC33_54
1555 NEC NL6448BC33-54. 10.4", 640x480.
1556 Active, color, single scan.
1560 Sharp 320x240. Active, color, single scan.
1561 It isn't 16x9, and I am not sure what it is.
1563 CONFIG_SHARP_LQ64D341
1565 Sharp LQ64D341 display, 640x480.
1566 Active, color, single scan.
1570 HLD1045 display, 640x480.
1571 Active, color, single scan.
1575 Optrex CBL50840-2 NF-FW 99 22 M5
1577 Hitachi LMG6912RPFC-00T
1581 320x240. Black & white.
1583 Normally display is black on white background; define
1584 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1586 CONFIG_LCD_ALIGNMENT
1588 Normally the LCD is page-aligned (tyically 4KB). If this is
1589 defined then the LCD will be aligned to this value instead.
1590 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1591 here, since it is cheaper to change data cache settings on
1592 a per-section basis.
1594 CONFIG_CONSOLE_SCROLL_LINES
1596 When the console need to be scrolled, this is the number of
1597 lines to scroll by. It defaults to 1. Increasing this makes
1598 the console jump but can help speed up operation when scrolling
1603 Support drawing of RLE8-compressed bitmaps on the LCD.
1607 Enables an 'i2c edid' command which can read EDID
1608 information over I2C from an attached LCD display.
1610 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1612 If this option is set, the environment is checked for
1613 a variable "splashimage". If found, the usual display
1614 of logo, copyright and system information on the LCD
1615 is suppressed and the BMP image at the address
1616 specified in "splashimage" is loaded instead. The
1617 console is redirected to the "nulldev", too. This
1618 allows for a "silent" boot where a splash screen is
1619 loaded very quickly after power-on.
1621 CONFIG_SPLASHIMAGE_GUARD
1623 If this option is set, then U-Boot will prevent the environment
1624 variable "splashimage" from being set to a problematic address
1625 (see README.displaying-bmps and README.arm-unaligned-accesses).
1626 This option is useful for targets where, due to alignment
1627 restrictions, an improperly aligned BMP image will cause a data
1628 abort. If you think you will not have problems with unaligned
1629 accesses (for example because your toolchain prevents them)
1630 there is no need to set this option.
1632 CONFIG_SPLASH_SCREEN_ALIGN
1634 If this option is set the splash image can be freely positioned
1635 on the screen. Environment variable "splashpos" specifies the
1636 position as "x,y". If a positive number is given it is used as
1637 number of pixel from left/top. If a negative number is given it
1638 is used as number of pixel from right/bottom. You can also
1639 specify 'm' for centering the image.
1642 setenv splashpos m,m
1643 => image at center of screen
1645 setenv splashpos 30,20
1646 => image at x = 30 and y = 20
1648 setenv splashpos -10,m
1649 => vertically centered image
1650 at x = dspWidth - bmpWidth - 9
1652 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1654 If this option is set, additionally to standard BMP
1655 images, gzipped BMP images can be displayed via the
1656 splashscreen support or the bmp command.
1658 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1660 If this option is set, 8-bit RLE compressed BMP images
1661 can be displayed via the splashscreen support or the
1664 - Do compresssing for memory range:
1667 If this option is set, it would use zlib deflate method
1668 to compress the specified memory at its best effort.
1670 - Compression support:
1673 If this option is set, support for bzip2 compressed
1674 images is included. If not, only uncompressed and gzip
1675 compressed images are supported.
1677 NOTE: the bzip2 algorithm requires a lot of RAM, so
1678 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1683 If this option is set, support for lzma compressed
1686 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1687 requires an amount of dynamic memory that is given by the
1690 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1692 Where lc and lp stand for, respectively, Literal context bits
1693 and Literal pos bits.
1695 This value is upper-bounded by 14MB in the worst case. Anyway,
1696 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1697 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1698 a very small buffer.
1700 Use the lzmainfo tool to determinate the lc and lp values and
1701 then calculate the amount of needed dynamic memory (ensuring
1702 the appropriate CONFIG_SYS_MALLOC_LEN value).
1707 The address of PHY on MII bus.
1709 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1711 The clock frequency of the MII bus
1715 If this option is set, support for speed/duplex
1716 detection of gigabit PHY is included.
1718 CONFIG_PHY_RESET_DELAY
1720 Some PHY like Intel LXT971A need extra delay after
1721 reset before any MII register access is possible.
1722 For such PHY, set this option to the usec delay
1723 required. (minimum 300usec for LXT971A)
1725 CONFIG_PHY_CMD_DELAY (ppc4xx)
1727 Some PHY like Intel LXT971A need extra delay after
1728 command issued before MII status register can be read
1738 Define a default value for Ethernet address to use
1739 for the respective Ethernet interface, in case this
1740 is not determined automatically.
1745 Define a default value for the IP address to use for
1746 the default Ethernet interface, in case this is not
1747 determined through e.g. bootp.
1748 (Environment variable "ipaddr")
1750 - Server IP address:
1753 Defines a default value for the IP address of a TFTP
1754 server to contact when using the "tftboot" command.
1755 (Environment variable "serverip")
1757 CONFIG_KEEP_SERVERADDR
1759 Keeps the server's MAC address, in the env 'serveraddr'
1760 for passing to bootargs (like Linux's netconsole option)
1762 - Gateway IP address:
1765 Defines a default value for the IP address of the
1766 default router where packets to other networks are
1768 (Environment variable "gatewayip")
1773 Defines a default value for the subnet mask (or
1774 routing prefix) which is used to determine if an IP
1775 address belongs to the local subnet or needs to be
1776 forwarded through a router.
1777 (Environment variable "netmask")
1779 - Multicast TFTP Mode:
1782 Defines whether you want to support multicast TFTP as per
1783 rfc-2090; for example to work with atftp. Lets lots of targets
1784 tftp down the same boot image concurrently. Note: the Ethernet
1785 driver in use must provide a function: mcast() to join/leave a
1788 - BOOTP Recovery Mode:
1789 CONFIG_BOOTP_RANDOM_DELAY
1791 If you have many targets in a network that try to
1792 boot using BOOTP, you may want to avoid that all
1793 systems send out BOOTP requests at precisely the same
1794 moment (which would happen for instance at recovery
1795 from a power failure, when all systems will try to
1796 boot, thus flooding the BOOTP server. Defining
1797 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1798 inserted before sending out BOOTP requests. The
1799 following delays are inserted then:
1801 1st BOOTP request: delay 0 ... 1 sec
1802 2nd BOOTP request: delay 0 ... 2 sec
1803 3rd BOOTP request: delay 0 ... 4 sec
1805 BOOTP requests: delay 0 ... 8 sec
1807 - DHCP Advanced Options:
1808 You can fine tune the DHCP functionality by defining
1809 CONFIG_BOOTP_* symbols:
1811 CONFIG_BOOTP_SUBNETMASK
1812 CONFIG_BOOTP_GATEWAY
1813 CONFIG_BOOTP_HOSTNAME
1814 CONFIG_BOOTP_NISDOMAIN
1815 CONFIG_BOOTP_BOOTPATH
1816 CONFIG_BOOTP_BOOTFILESIZE
1819 CONFIG_BOOTP_SEND_HOSTNAME
1820 CONFIG_BOOTP_NTPSERVER
1821 CONFIG_BOOTP_TIMEOFFSET
1822 CONFIG_BOOTP_VENDOREX
1823 CONFIG_BOOTP_MAY_FAIL
1825 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1826 environment variable, not the BOOTP server.
1828 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1829 after the configured retry count, the call will fail
1830 instead of starting over. This can be used to fail over
1831 to Link-local IP address configuration if the DHCP server
1834 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1835 serverip from a DHCP server, it is possible that more
1836 than one DNS serverip is offered to the client.
1837 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1838 serverip will be stored in the additional environment
1839 variable "dnsip2". The first DNS serverip is always
1840 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1843 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1844 to do a dynamic update of a DNS server. To do this, they
1845 need the hostname of the DHCP requester.
1846 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1847 of the "hostname" environment variable is passed as
1848 option 12 to the DHCP server.
1850 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1852 A 32bit value in microseconds for a delay between
1853 receiving a "DHCP Offer" and sending the "DHCP Request".
1854 This fixes a problem with certain DHCP servers that don't
1855 respond 100% of the time to a "DHCP request". E.g. On an
1856 AT91RM9200 processor running at 180MHz, this delay needed
1857 to be *at least* 15,000 usec before a Windows Server 2003
1858 DHCP server would reply 100% of the time. I recommend at
1859 least 50,000 usec to be safe. The alternative is to hope
1860 that one of the retries will be successful but note that
1861 the DHCP timeout and retry process takes a longer than
1864 - Link-local IP address negotiation:
1865 Negotiate with other link-local clients on the local network
1866 for an address that doesn't require explicit configuration.
1867 This is especially useful if a DHCP server cannot be guaranteed
1868 to exist in all environments that the device must operate.
1870 See doc/README.link-local for more information.
1873 CONFIG_CDP_DEVICE_ID
1875 The device id used in CDP trigger frames.
1877 CONFIG_CDP_DEVICE_ID_PREFIX
1879 A two character string which is prefixed to the MAC address
1884 A printf format string which contains the ascii name of
1885 the port. Normally is set to "eth%d" which sets
1886 eth0 for the first Ethernet, eth1 for the second etc.
1888 CONFIG_CDP_CAPABILITIES
1890 A 32bit integer which indicates the device capabilities;
1891 0x00000010 for a normal host which does not forwards.
1895 An ascii string containing the version of the software.
1899 An ascii string containing the name of the platform.
1903 A 32bit integer sent on the trigger.
1905 CONFIG_CDP_POWER_CONSUMPTION
1907 A 16bit integer containing the power consumption of the
1908 device in .1 of milliwatts.
1910 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1912 A byte containing the id of the VLAN.
1914 - Status LED: CONFIG_STATUS_LED
1916 Several configurations allow to display the current
1917 status using a LED. For instance, the LED will blink
1918 fast while running U-Boot code, stop blinking as
1919 soon as a reply to a BOOTP request was received, and
1920 start blinking slow once the Linux kernel is running
1921 (supported by a status LED driver in the Linux
1922 kernel). Defining CONFIG_STATUS_LED enables this
1925 - CAN Support: CONFIG_CAN_DRIVER
1927 Defining CONFIG_CAN_DRIVER enables CAN driver support
1928 on those systems that support this (optional)
1929 feature, like the TQM8xxL modules.
1931 - I2C Support: CONFIG_SYS_I2C
1933 This enable the NEW i2c subsystem, and will allow you to use
1934 i2c commands at the u-boot command line (as long as you set
1935 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1936 based realtime clock chips or other i2c devices. See
1937 common/cmd_i2c.c for a description of the command line
1940 ported i2c driver to the new framework:
1941 - drivers/i2c/soft_i2c.c:
1942 - activate first bus with CONFIG_SYS_I2C_SOFT define
1943 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1944 for defining speed and slave address
1945 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1946 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1947 for defining speed and slave address
1948 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1949 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1950 for defining speed and slave address
1951 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1952 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1953 for defining speed and slave address
1955 - drivers/i2c/fsl_i2c.c:
1956 - activate i2c driver with CONFIG_SYS_I2C_FSL
1957 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1958 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1959 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1961 - If your board supports a second fsl i2c bus, define
1962 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1963 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1964 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1967 - drivers/i2c/tegra_i2c.c:
1968 - activate this driver with CONFIG_SYS_I2C_TEGRA
1969 - This driver adds 4 i2c buses with a fix speed from
1970 100000 and the slave addr 0!
1972 - drivers/i2c/ppc4xx_i2c.c
1973 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1974 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1975 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1979 CONFIG_SYS_NUM_I2C_BUSES
1980 Hold the number of i2c busses you want to use. If you
1981 don't use/have i2c muxes on your i2c bus, this
1982 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
1985 CONFIG_SYS_I2C_DIRECT_BUS
1986 define this, if you don't use i2c muxes on your hardware.
1987 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1990 CONFIG_SYS_I2C_MAX_HOPS
1991 define how many muxes are maximal consecutively connected
1992 on one i2c bus. If you not use i2c muxes, omit this
1995 CONFIG_SYS_I2C_BUSES
1996 hold a list of busses you want to use, only used if
1997 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1998 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1999 CONFIG_SYS_NUM_I2C_BUSES = 9:
2001 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2002 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2003 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2004 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2005 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2006 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2007 {1, {I2C_NULL_HOP}}, \
2008 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2009 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2013 bus 0 on adapter 0 without a mux
2014 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2015 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2016 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2017 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2018 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2019 bus 6 on adapter 1 without a mux
2020 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2021 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2023 If you do not have i2c muxes on your board, omit this define.
2025 - Legacy I2C Support: CONFIG_HARD_I2C
2027 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2028 provides the following compelling advantages:
2030 - more than one i2c adapter is usable
2031 - approved multibus support
2032 - better i2c mux support
2034 ** Please consider updating your I2C driver now. **
2036 These enable legacy I2C serial bus commands. Defining
2037 CONFIG_HARD_I2C will include the appropriate I2C driver
2038 for the selected CPU.
2040 This will allow you to use i2c commands at the u-boot
2041 command line (as long as you set CONFIG_CMD_I2C in
2042 CONFIG_COMMANDS) and communicate with i2c based realtime
2043 clock chips. See common/cmd_i2c.c for a description of the
2044 command line interface.
2046 CONFIG_HARD_I2C selects a hardware I2C controller.
2048 There are several other quantities that must also be
2049 defined when you define CONFIG_HARD_I2C.
2051 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2052 to be the frequency (in Hz) at which you wish your i2c bus
2053 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2054 the CPU's i2c node address).
2056 Now, the u-boot i2c code for the mpc8xx
2057 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2058 and so its address should therefore be cleared to 0 (See,
2059 eg, MPC823e User's Manual p.16-473). So, set
2060 CONFIG_SYS_I2C_SLAVE to 0.
2062 CONFIG_SYS_I2C_INIT_MPC5XXX
2064 When a board is reset during an i2c bus transfer
2065 chips might think that the current transfer is still
2066 in progress. Reset the slave devices by sending start
2067 commands until the slave device responds.
2069 That's all that's required for CONFIG_HARD_I2C.
2071 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2072 then the following macros need to be defined (examples are
2073 from include/configs/lwmon.h):
2077 (Optional). Any commands necessary to enable the I2C
2078 controller or configure ports.
2080 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2084 (Only for MPC8260 CPU). The I/O port to use (the code
2085 assumes both bits are on the same port). Valid values
2086 are 0..3 for ports A..D.
2090 The code necessary to make the I2C data line active
2091 (driven). If the data line is open collector, this
2094 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2098 The code necessary to make the I2C data line tri-stated
2099 (inactive). If the data line is open collector, this
2102 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2106 Code that returns true if the I2C data line is high,
2109 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2113 If <bit> is true, sets the I2C data line high. If it
2114 is false, it clears it (low).
2116 eg: #define I2C_SDA(bit) \
2117 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2118 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2122 If <bit> is true, sets the I2C clock line high. If it
2123 is false, it clears it (low).
2125 eg: #define I2C_SCL(bit) \
2126 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2127 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2131 This delay is invoked four times per clock cycle so this
2132 controls the rate of data transfer. The data rate thus
2133 is 1 / (I2C_DELAY * 4). Often defined to be something
2136 #define I2C_DELAY udelay(2)
2138 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2140 If your arch supports the generic GPIO framework (asm/gpio.h),
2141 then you may alternatively define the two GPIOs that are to be
2142 used as SCL / SDA. Any of the previous I2C_xxx macros will
2143 have GPIO-based defaults assigned to them as appropriate.
2145 You should define these to the GPIO value as given directly to
2146 the generic GPIO functions.
2148 CONFIG_SYS_I2C_INIT_BOARD
2150 When a board is reset during an i2c bus transfer
2151 chips might think that the current transfer is still
2152 in progress. On some boards it is possible to access
2153 the i2c SCLK line directly, either by using the
2154 processor pin as a GPIO or by having a second pin
2155 connected to the bus. If this option is defined a
2156 custom i2c_init_board() routine in boards/xxx/board.c
2157 is run early in the boot sequence.
2159 CONFIG_SYS_I2C_BOARD_LATE_INIT
2161 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2162 defined a custom i2c_board_late_init() routine in
2163 boards/xxx/board.c is run AFTER the operations in i2c_init()
2164 is completed. This callpoint can be used to unreset i2c bus
2165 using CPU i2c controller register accesses for CPUs whose i2c
2166 controller provide such a method. It is called at the end of
2167 i2c_init() to allow i2c_init operations to setup the i2c bus
2168 controller on the CPU (e.g. setting bus speed & slave address).
2170 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2172 This option enables configuration of bi_iic_fast[] flags
2173 in u-boot bd_info structure based on u-boot environment
2174 variable "i2cfast". (see also i2cfast)
2176 CONFIG_I2C_MULTI_BUS
2178 This option allows the use of multiple I2C buses, each of which
2179 must have a controller. At any point in time, only one bus is
2180 active. To switch to a different bus, use the 'i2c dev' command.
2181 Note that bus numbering is zero-based.
2183 CONFIG_SYS_I2C_NOPROBES
2185 This option specifies a list of I2C devices that will be skipped
2186 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2187 is set, specify a list of bus-device pairs. Otherwise, specify
2188 a 1D array of device addresses
2191 #undef CONFIG_I2C_MULTI_BUS
2192 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2194 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2196 #define CONFIG_I2C_MULTI_BUS
2197 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2199 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2201 CONFIG_SYS_SPD_BUS_NUM
2203 If defined, then this indicates the I2C bus number for DDR SPD.
2204 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2206 CONFIG_SYS_RTC_BUS_NUM
2208 If defined, then this indicates the I2C bus number for the RTC.
2209 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2211 CONFIG_SYS_DTT_BUS_NUM
2213 If defined, then this indicates the I2C bus number for the DTT.
2214 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2216 CONFIG_SYS_I2C_DTT_ADDR:
2218 If defined, specifies the I2C address of the DTT device.
2219 If not defined, then U-Boot uses predefined value for
2220 specified DTT device.
2222 CONFIG_SOFT_I2C_READ_REPEATED_START
2224 defining this will force the i2c_read() function in
2225 the soft_i2c driver to perform an I2C repeated start
2226 between writing the address pointer and reading the
2227 data. If this define is omitted the default behaviour
2228 of doing a stop-start sequence will be used. Most I2C
2229 devices can use either method, but some require one or
2232 - SPI Support: CONFIG_SPI
2234 Enables SPI driver (so far only tested with
2235 SPI EEPROM, also an instance works with Crystal A/D and
2236 D/As on the SACSng board)
2240 Enables the driver for SPI controller on SuperH. Currently
2241 only SH7757 is supported.
2245 Enables extended (16-bit) SPI EEPROM addressing.
2246 (symmetrical to CONFIG_I2C_X)
2250 Enables a software (bit-bang) SPI driver rather than
2251 using hardware support. This is a general purpose
2252 driver that only requires three general I/O port pins
2253 (two outputs, one input) to function. If this is
2254 defined, the board configuration must define several
2255 SPI configuration items (port pins to use, etc). For
2256 an example, see include/configs/sacsng.h.
2260 Enables a hardware SPI driver for general-purpose reads
2261 and writes. As with CONFIG_SOFT_SPI, the board configuration
2262 must define a list of chip-select function pointers.
2263 Currently supported on some MPC8xxx processors. For an
2264 example, see include/configs/mpc8349emds.h.
2268 Enables the driver for the SPI controllers on i.MX and MXC
2269 SoCs. Currently i.MX31/35/51 are supported.
2271 - FPGA Support: CONFIG_FPGA
2273 Enables FPGA subsystem.
2275 CONFIG_FPGA_<vendor>
2277 Enables support for specific chip vendors.
2280 CONFIG_FPGA_<family>
2282 Enables support for FPGA family.
2283 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2287 Specify the number of FPGA devices to support.
2289 CONFIG_SYS_FPGA_PROG_FEEDBACK
2291 Enable printing of hash marks during FPGA configuration.
2293 CONFIG_SYS_FPGA_CHECK_BUSY
2295 Enable checks on FPGA configuration interface busy
2296 status by the configuration function. This option
2297 will require a board or device specific function to
2302 If defined, a function that provides delays in the FPGA
2303 configuration driver.
2305 CONFIG_SYS_FPGA_CHECK_CTRLC
2306 Allow Control-C to interrupt FPGA configuration
2308 CONFIG_SYS_FPGA_CHECK_ERROR
2310 Check for configuration errors during FPGA bitfile
2311 loading. For example, abort during Virtex II
2312 configuration if the INIT_B line goes low (which
2313 indicated a CRC error).
2315 CONFIG_SYS_FPGA_WAIT_INIT
2317 Maximum time to wait for the INIT_B line to deassert
2318 after PROB_B has been deasserted during a Virtex II
2319 FPGA configuration sequence. The default time is 500
2322 CONFIG_SYS_FPGA_WAIT_BUSY
2324 Maximum time to wait for BUSY to deassert during
2325 Virtex II FPGA configuration. The default is 5 ms.
2327 CONFIG_SYS_FPGA_WAIT_CONFIG
2329 Time to wait after FPGA configuration. The default is
2332 - Configuration Management:
2335 If defined, this string will be added to the U-Boot
2336 version information (U_BOOT_VERSION)
2338 - Vendor Parameter Protection:
2340 U-Boot considers the values of the environment
2341 variables "serial#" (Board Serial Number) and
2342 "ethaddr" (Ethernet Address) to be parameters that
2343 are set once by the board vendor / manufacturer, and
2344 protects these variables from casual modification by
2345 the user. Once set, these variables are read-only,
2346 and write or delete attempts are rejected. You can
2347 change this behaviour:
2349 If CONFIG_ENV_OVERWRITE is #defined in your config
2350 file, the write protection for vendor parameters is
2351 completely disabled. Anybody can change or delete
2354 Alternatively, if you #define _both_ CONFIG_ETHADDR
2355 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2356 Ethernet address is installed in the environment,
2357 which can be changed exactly ONCE by the user. [The
2358 serial# is unaffected by this, i. e. it remains
2361 The same can be accomplished in a more flexible way
2362 for any variable by configuring the type of access
2363 to allow for those variables in the ".flags" variable
2364 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2369 Define this variable to enable the reservation of
2370 "protected RAM", i. e. RAM which is not overwritten
2371 by U-Boot. Define CONFIG_PRAM to hold the number of
2372 kB you want to reserve for pRAM. You can overwrite
2373 this default value by defining an environment
2374 variable "pram" to the number of kB you want to
2375 reserve. Note that the board info structure will
2376 still show the full amount of RAM. If pRAM is
2377 reserved, a new environment variable "mem" will
2378 automatically be defined to hold the amount of
2379 remaining RAM in a form that can be passed as boot
2380 argument to Linux, for instance like that:
2382 setenv bootargs ... mem=\${mem}
2385 This way you can tell Linux not to use this memory,
2386 either, which results in a memory region that will
2387 not be affected by reboots.
2389 *WARNING* If your board configuration uses automatic
2390 detection of the RAM size, you must make sure that
2391 this memory test is non-destructive. So far, the
2392 following board configurations are known to be
2395 IVMS8, IVML24, SPD8xx, TQM8xxL,
2396 HERMES, IP860, RPXlite, LWMON,
2399 - Access to physical memory region (> 4GB)
2400 Some basic support is provided for operations on memory not
2401 normally accessible to U-Boot - e.g. some architectures
2402 support access to more than 4GB of memory on 32-bit
2403 machines using physical address extension or similar.
2404 Define CONFIG_PHYSMEM to access this basic support, which
2405 currently only supports clearing the memory.
2410 Define this variable to stop the system in case of a
2411 fatal error, so that you have to reset it manually.
2412 This is probably NOT a good idea for an embedded
2413 system where you want the system to reboot
2414 automatically as fast as possible, but it may be
2415 useful during development since you can try to debug
2416 the conditions that lead to the situation.
2418 CONFIG_NET_RETRY_COUNT
2420 This variable defines the number of retries for
2421 network operations like ARP, RARP, TFTP, or BOOTP
2422 before giving up the operation. If not defined, a
2423 default value of 5 is used.
2427 Timeout waiting for an ARP reply in milliseconds.
2431 Timeout in milliseconds used in NFS protocol.
2432 If you encounter "ERROR: Cannot umount" in nfs command,
2433 try longer timeout such as
2434 #define CONFIG_NFS_TIMEOUT 10000UL
2436 - Command Interpreter:
2437 CONFIG_AUTO_COMPLETE
2439 Enable auto completion of commands using TAB.
2441 Note that this feature has NOT been implemented yet
2442 for the "hush" shell.
2445 CONFIG_SYS_HUSH_PARSER
2447 Define this variable to enable the "hush" shell (from
2448 Busybox) as command line interpreter, thus enabling
2449 powerful command line syntax like
2450 if...then...else...fi conditionals or `&&' and '||'
2451 constructs ("shell scripts").
2453 If undefined, you get the old, much simpler behaviour
2454 with a somewhat smaller memory footprint.
2457 CONFIG_SYS_PROMPT_HUSH_PS2
2459 This defines the secondary prompt string, which is
2460 printed when the command interpreter needs more input
2461 to complete a command. Usually "> ".
2465 In the current implementation, the local variables
2466 space and global environment variables space are
2467 separated. Local variables are those you define by
2468 simply typing `name=value'. To access a local
2469 variable later on, you have write `$name' or
2470 `${name}'; to execute the contents of a variable
2471 directly type `$name' at the command prompt.
2473 Global environment variables are those you use
2474 setenv/printenv to work with. To run a command stored
2475 in such a variable, you need to use the run command,
2476 and you must not use the '$' sign to access them.
2478 To store commands and special characters in a
2479 variable, please use double quotation marks
2480 surrounding the whole text of the variable, instead
2481 of the backslashes before semicolons and special
2484 - Commandline Editing and History:
2485 CONFIG_CMDLINE_EDITING
2487 Enable editing and History functions for interactive
2488 commandline input operations
2490 - Default Environment:
2491 CONFIG_EXTRA_ENV_SETTINGS
2493 Define this to contain any number of null terminated
2494 strings (variable = value pairs) that will be part of
2495 the default environment compiled into the boot image.
2497 For example, place something like this in your
2498 board's config file:
2500 #define CONFIG_EXTRA_ENV_SETTINGS \
2504 Warning: This method is based on knowledge about the
2505 internal format how the environment is stored by the
2506 U-Boot code. This is NOT an official, exported
2507 interface! Although it is unlikely that this format
2508 will change soon, there is no guarantee either.
2509 You better know what you are doing here.
2511 Note: overly (ab)use of the default environment is
2512 discouraged. Make sure to check other ways to preset
2513 the environment like the "source" command or the
2516 CONFIG_ENV_VARS_UBOOT_CONFIG
2518 Define this in order to add variables describing the
2519 U-Boot build configuration to the default environment.
2520 These will be named arch, cpu, board, vendor, and soc.
2522 Enabling this option will cause the following to be defined:
2530 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2532 Define this in order to add variables describing certain
2533 run-time determined information about the hardware to the
2534 environment. These will be named board_name, board_rev.
2536 CONFIG_DELAY_ENVIRONMENT
2538 Normally the environment is loaded when the board is
2539 intialised so that it is available to U-Boot. This inhibits
2540 that so that the environment is not available until
2541 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2542 this is instead controlled by the value of
2543 /config/load-environment.
2545 - DataFlash Support:
2546 CONFIG_HAS_DATAFLASH
2548 Defining this option enables DataFlash features and
2549 allows to read/write in Dataflash via the standard
2552 - Serial Flash support
2555 Defining this option enables SPI flash commands
2556 'sf probe/read/write/erase/update'.
2558 Usage requires an initial 'probe' to define the serial
2559 flash parameters, followed by read/write/erase/update
2562 The following defaults may be provided by the platform
2563 to handle the common case when only a single serial
2564 flash is present on the system.
2566 CONFIG_SF_DEFAULT_BUS Bus identifier
2567 CONFIG_SF_DEFAULT_CS Chip-select
2568 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2569 CONFIG_SF_DEFAULT_SPEED in Hz
2573 Define this option to include a destructive SPI flash
2576 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2578 Define this option to use the Bank addr/Extended addr
2579 support on SPI flashes which has size > 16Mbytes.
2581 - SystemACE Support:
2584 Adding this option adds support for Xilinx SystemACE
2585 chips attached via some sort of local bus. The address
2586 of the chip must also be defined in the
2587 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2589 #define CONFIG_SYSTEMACE
2590 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2592 When SystemACE support is added, the "ace" device type
2593 becomes available to the fat commands, i.e. fatls.
2595 - TFTP Fixed UDP Port:
2598 If this is defined, the environment variable tftpsrcp
2599 is used to supply the TFTP UDP source port value.
2600 If tftpsrcp isn't defined, the normal pseudo-random port
2601 number generator is used.
2603 Also, the environment variable tftpdstp is used to supply
2604 the TFTP UDP destination port value. If tftpdstp isn't
2605 defined, the normal port 69 is used.
2607 The purpose for tftpsrcp is to allow a TFTP server to
2608 blindly start the TFTP transfer using the pre-configured
2609 target IP address and UDP port. This has the effect of
2610 "punching through" the (Windows XP) firewall, allowing
2611 the remainder of the TFTP transfer to proceed normally.
2612 A better solution is to properly configure the firewall,
2613 but sometimes that is not allowed.
2618 This enables a generic 'hash' command which can produce
2619 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2623 Enable the hash verify command (hash -v). This adds to code
2626 CONFIG_SHA1 - support SHA1 hashing
2627 CONFIG_SHA256 - support SHA256 hashing
2629 Note: There is also a sha1sum command, which should perhaps
2630 be deprecated in favour of 'hash sha1'.
2632 - Freescale i.MX specific commands:
2633 CONFIG_CMD_HDMIDETECT
2634 This enables 'hdmidet' command which returns true if an
2635 HDMI monitor is detected. This command is i.MX 6 specific.
2638 This enables the 'bmode' (bootmode) command for forcing
2639 a boot from specific media.
2641 This is useful for forcing the ROM's usb downloader to
2642 activate upon a watchdog reset which is nice when iterating
2643 on U-Boot. Using the reset button or running bmode normal
2644 will set it back to normal. This command currently
2645 supports i.MX53 and i.MX6.
2650 This enables the RSA algorithm used for FIT image verification
2651 in U-Boot. See doc/uImage/signature for more information.
2653 The signing part is build into mkimage regardless of this
2657 - Show boot progress:
2658 CONFIG_SHOW_BOOT_PROGRESS
2660 Defining this option allows to add some board-
2661 specific code (calling a user-provided function
2662 "show_boot_progress(int)") that enables you to show
2663 the system's boot progress on some display (for
2664 example, some LED's) on your board. At the moment,
2665 the following checkpoints are implemented:
2667 - Detailed boot stage timing
2669 Define this option to get detailed timing of each stage
2670 of the boot process.
2672 CONFIG_BOOTSTAGE_USER_COUNT
2673 This is the number of available user bootstage records.
2674 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2675 a new ID will be allocated from this stash. If you exceed
2676 the limit, recording will stop.
2678 CONFIG_BOOTSTAGE_REPORT
2679 Define this to print a report before boot, similar to this:
2681 Timer summary in microseconds:
2684 3,575,678 3,575,678 board_init_f start
2685 3,575,695 17 arch_cpu_init A9
2686 3,575,777 82 arch_cpu_init done
2687 3,659,598 83,821 board_init_r start
2688 3,910,375 250,777 main_loop
2689 29,916,167 26,005,792 bootm_start
2690 30,361,327 445,160 start_kernel
2692 CONFIG_CMD_BOOTSTAGE
2693 Add a 'bootstage' command which supports printing a report
2694 and un/stashing of bootstage data.
2696 CONFIG_BOOTSTAGE_FDT
2697 Stash the bootstage information in the FDT. A root 'bootstage'
2698 node is created with each bootstage id as a child. Each child
2699 has a 'name' property and either 'mark' containing the
2700 mark time in microsecond, or 'accum' containing the
2701 accumulated time for that bootstage id in microseconds.
2706 name = "board_init_f";
2715 Code in the Linux kernel can find this in /proc/devicetree.
2717 Legacy uImage format:
2720 1 common/cmd_bootm.c before attempting to boot an image
2721 -1 common/cmd_bootm.c Image header has bad magic number
2722 2 common/cmd_bootm.c Image header has correct magic number
2723 -2 common/cmd_bootm.c Image header has bad checksum
2724 3 common/cmd_bootm.c Image header has correct checksum
2725 -3 common/cmd_bootm.c Image data has bad checksum
2726 4 common/cmd_bootm.c Image data has correct checksum
2727 -4 common/cmd_bootm.c Image is for unsupported architecture
2728 5 common/cmd_bootm.c Architecture check OK
2729 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2730 6 common/cmd_bootm.c Image Type check OK
2731 -6 common/cmd_bootm.c gunzip uncompression error
2732 -7 common/cmd_bootm.c Unimplemented compression type
2733 7 common/cmd_bootm.c Uncompression OK
2734 8 common/cmd_bootm.c No uncompress/copy overwrite error
2735 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2737 9 common/image.c Start initial ramdisk verification
2738 -10 common/image.c Ramdisk header has bad magic number
2739 -11 common/image.c Ramdisk header has bad checksum
2740 10 common/image.c Ramdisk header is OK
2741 -12 common/image.c Ramdisk data has bad checksum
2742 11 common/image.c Ramdisk data has correct checksum
2743 12 common/image.c Ramdisk verification complete, start loading
2744 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2745 13 common/image.c Start multifile image verification
2746 14 common/image.c No initial ramdisk, no multifile, continue.
2748 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2750 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2751 -31 post/post.c POST test failed, detected by post_output_backlog()
2752 -32 post/post.c POST test failed, detected by post_run_single()
2754 34 common/cmd_doc.c before loading a Image from a DOC device
2755 -35 common/cmd_doc.c Bad usage of "doc" command
2756 35 common/cmd_doc.c correct usage of "doc" command
2757 -36 common/cmd_doc.c No boot device
2758 36 common/cmd_doc.c correct boot device
2759 -37 common/cmd_doc.c Unknown Chip ID on boot device
2760 37 common/cmd_doc.c correct chip ID found, device available
2761 -38 common/cmd_doc.c Read Error on boot device
2762 38 common/cmd_doc.c reading Image header from DOC device OK
2763 -39 common/cmd_doc.c Image header has bad magic number
2764 39 common/cmd_doc.c Image header has correct magic number
2765 -40 common/cmd_doc.c Error reading Image from DOC device
2766 40 common/cmd_doc.c Image header has correct magic number
2767 41 common/cmd_ide.c before loading a Image from a IDE device
2768 -42 common/cmd_ide.c Bad usage of "ide" command
2769 42 common/cmd_ide.c correct usage of "ide" command
2770 -43 common/cmd_ide.c No boot device
2771 43 common/cmd_ide.c boot device found
2772 -44 common/cmd_ide.c Device not available
2773 44 common/cmd_ide.c Device available
2774 -45 common/cmd_ide.c wrong partition selected
2775 45 common/cmd_ide.c partition selected
2776 -46 common/cmd_ide.c Unknown partition table
2777 46 common/cmd_ide.c valid partition table found
2778 -47 common/cmd_ide.c Invalid partition type
2779 47 common/cmd_ide.c correct partition type
2780 -48 common/cmd_ide.c Error reading Image Header on boot device
2781 48 common/cmd_ide.c reading Image Header from IDE device OK
2782 -49 common/cmd_ide.c Image header has bad magic number
2783 49 common/cmd_ide.c Image header has correct magic number
2784 -50 common/cmd_ide.c Image header has bad checksum
2785 50 common/cmd_ide.c Image header has correct checksum
2786 -51 common/cmd_ide.c Error reading Image from IDE device
2787 51 common/cmd_ide.c reading Image from IDE device OK
2788 52 common/cmd_nand.c before loading a Image from a NAND device
2789 -53 common/cmd_nand.c Bad usage of "nand" command
2790 53 common/cmd_nand.c correct usage of "nand" command
2791 -54 common/cmd_nand.c No boot device
2792 54 common/cmd_nand.c boot device found
2793 -55 common/cmd_nand.c Unknown Chip ID on boot device
2794 55 common/cmd_nand.c correct chip ID found, device available
2795 -56 common/cmd_nand.c Error reading Image Header on boot device
2796 56 common/cmd_nand.c reading Image Header from NAND device OK
2797 -57 common/cmd_nand.c Image header has bad magic number
2798 57 common/cmd_nand.c Image header has correct magic number
2799 -58 common/cmd_nand.c Error reading Image from NAND device
2800 58 common/cmd_nand.c reading Image from NAND device OK
2802 -60 common/env_common.c Environment has a bad CRC, using default
2804 64 net/eth.c starting with Ethernet configuration.
2805 -64 net/eth.c no Ethernet found.
2806 65 net/eth.c Ethernet found.
2808 -80 common/cmd_net.c usage wrong
2809 80 common/cmd_net.c before calling NetLoop()
2810 -81 common/cmd_net.c some error in NetLoop() occurred
2811 81 common/cmd_net.c NetLoop() back without error
2812 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2813 82 common/cmd_net.c trying automatic boot
2814 83 common/cmd_net.c running "source" command
2815 -83 common/cmd_net.c some error in automatic boot or "source" command
2816 84 common/cmd_net.c end without errors
2821 100 common/cmd_bootm.c Kernel FIT Image has correct format
2822 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2823 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2824 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2825 102 common/cmd_bootm.c Kernel unit name specified
2826 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2827 103 common/cmd_bootm.c Found configuration node
2828 104 common/cmd_bootm.c Got kernel subimage node offset
2829 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2830 105 common/cmd_bootm.c Kernel subimage hash verification OK
2831 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2832 106 common/cmd_bootm.c Architecture check OK
2833 -106 common/cmd_bootm.c Kernel subimage has wrong type
2834 107 common/cmd_bootm.c Kernel subimage type OK
2835 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2836 108 common/cmd_bootm.c Got kernel subimage data/size
2837 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2838 -109 common/cmd_bootm.c Can't get kernel subimage type
2839 -110 common/cmd_bootm.c Can't get kernel subimage comp
2840 -111 common/cmd_bootm.c Can't get kernel subimage os
2841 -112 common/cmd_bootm.c Can't get kernel subimage load address
2842 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2844 120 common/image.c Start initial ramdisk verification
2845 -120 common/image.c Ramdisk FIT image has incorrect format
2846 121 common/image.c Ramdisk FIT image has correct format
2847 122 common/image.c No ramdisk subimage unit name, using configuration
2848 -122 common/image.c Can't get configuration for ramdisk subimage
2849 123 common/image.c Ramdisk unit name specified
2850 -124 common/image.c Can't get ramdisk subimage node offset
2851 125 common/image.c Got ramdisk subimage node offset
2852 -125 common/image.c Ramdisk subimage hash verification failed
2853 126 common/image.c Ramdisk subimage hash verification OK
2854 -126 common/image.c Ramdisk subimage for unsupported architecture
2855 127 common/image.c Architecture check OK
2856 -127 common/image.c Can't get ramdisk subimage data/size
2857 128 common/image.c Got ramdisk subimage data/size
2858 129 common/image.c Can't get ramdisk load address
2859 -129 common/image.c Got ramdisk load address
2861 -130 common/cmd_doc.c Incorrect FIT image format
2862 131 common/cmd_doc.c FIT image format OK
2864 -140 common/cmd_ide.c Incorrect FIT image format
2865 141 common/cmd_ide.c FIT image format OK
2867 -150 common/cmd_nand.c Incorrect FIT image format
2868 151 common/cmd_nand.c FIT image format OK
2870 - FIT image support:
2872 Enable support for the FIT uImage format.
2874 CONFIG_FIT_BEST_MATCH
2875 When no configuration is explicitly selected, default to the
2876 one whose fdt's compatibility field best matches that of
2877 U-Boot itself. A match is considered "best" if it matches the
2878 most specific compatibility entry of U-Boot's fdt's root node.
2879 The order of entries in the configuration's fdt is ignored.
2881 CONFIG_FIT_SIGNATURE
2882 This option enables signature verification of FIT uImages,
2883 using a hash signed and verified using RSA. See
2884 doc/uImage.FIT/signature.txt for more details.
2886 - Standalone program support:
2887 CONFIG_STANDALONE_LOAD_ADDR
2889 This option defines a board specific value for the
2890 address where standalone program gets loaded, thus
2891 overwriting the architecture dependent default
2894 - Frame Buffer Address:
2897 Define CONFIG_FB_ADDR if you want to use specific
2898 address for frame buffer. This is typically the case
2899 when using a graphics controller has separate video
2900 memory. U-Boot will then place the frame buffer at
2901 the given address instead of dynamically reserving it
2902 in system RAM by calling lcd_setmem(), which grabs
2903 the memory for the frame buffer depending on the
2904 configured panel size.
2906 Please see board_init_f function.
2908 - Automatic software updates via TFTP server
2910 CONFIG_UPDATE_TFTP_CNT_MAX
2911 CONFIG_UPDATE_TFTP_MSEC_MAX
2913 These options enable and control the auto-update feature;
2914 for a more detailed description refer to doc/README.update.
2916 - MTD Support (mtdparts command, UBI support)
2919 Adds the MTD device infrastructure from the Linux kernel.
2920 Needed for mtdparts command support.
2922 CONFIG_MTD_PARTITIONS
2924 Adds the MTD partitioning infrastructure from the Linux
2925 kernel. Needed for UBI support.
2930 Adds commands for interacting with MTD partitions formatted
2931 with the UBI flash translation layer
2933 Requires also defining CONFIG_RBTREE
2935 CONFIG_UBI_SILENCE_MSG
2937 Make the verbose messages from UBI stop printing. This leaves
2938 warnings and errors enabled.
2943 Adds commands for interacting with UBI volumes formatted as
2944 UBIFS. UBIFS is read-only in u-boot.
2946 Requires UBI support as well as CONFIG_LZO
2948 CONFIG_UBIFS_SILENCE_MSG
2950 Make the verbose messages from UBIFS stop printing. This leaves
2951 warnings and errors enabled.
2955 Enable building of SPL globally.
2958 LDSCRIPT for linking the SPL binary.
2960 CONFIG_SPL_MAX_FOOTPRINT
2961 Maximum size in memory allocated to the SPL, BSS included.
2962 When defined, the linker checks that the actual memory
2963 used by SPL from _start to __bss_end does not exceed it.
2964 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2965 must not be both defined at the same time.
2968 Maximum size of the SPL image (text, data, rodata, and
2969 linker lists sections), BSS excluded.
2970 When defined, the linker checks that the actual size does
2973 CONFIG_SPL_TEXT_BASE
2974 TEXT_BASE for linking the SPL binary.
2976 CONFIG_SPL_RELOC_TEXT_BASE
2977 Address to relocate to. If unspecified, this is equal to
2978 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2980 CONFIG_SPL_BSS_START_ADDR
2981 Link address for the BSS within the SPL binary.
2983 CONFIG_SPL_BSS_MAX_SIZE
2984 Maximum size in memory allocated to the SPL BSS.
2985 When defined, the linker checks that the actual memory used
2986 by SPL from __bss_start to __bss_end does not exceed it.
2987 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2988 must not be both defined at the same time.
2991 Adress of the start of the stack SPL will use
2993 CONFIG_SPL_RELOC_STACK
2994 Adress of the start of the stack SPL will use after
2995 relocation. If unspecified, this is equal to
2998 CONFIG_SYS_SPL_MALLOC_START
2999 Starting address of the malloc pool used in SPL.
3001 CONFIG_SYS_SPL_MALLOC_SIZE
3002 The size of the malloc pool used in SPL.
3004 CONFIG_SPL_FRAMEWORK
3005 Enable the SPL framework under common/. This framework
3006 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3007 NAND loading of the Linux Kernel.
3009 CONFIG_SPL_DISPLAY_PRINT
3010 For ARM, enable an optional function to print more information
3011 about the running system.
3013 CONFIG_SPL_INIT_MINIMAL
3014 Arch init code should be built for a very small image
3016 CONFIG_SPL_LIBCOMMON_SUPPORT
3017 Support for common/libcommon.o in SPL binary
3019 CONFIG_SPL_LIBDISK_SUPPORT
3020 Support for disk/libdisk.o in SPL binary
3022 CONFIG_SPL_I2C_SUPPORT
3023 Support for drivers/i2c/libi2c.o in SPL binary
3025 CONFIG_SPL_GPIO_SUPPORT
3026 Support for drivers/gpio/libgpio.o in SPL binary
3028 CONFIG_SPL_MMC_SUPPORT
3029 Support for drivers/mmc/libmmc.o in SPL binary
3031 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3032 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3033 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3034 Address, size and partition on the MMC to load U-Boot from
3035 when the MMC is being used in raw mode.
3037 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3038 Sector to load kernel uImage from when MMC is being
3039 used in raw mode (for Falcon mode)
3041 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3042 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3043 Sector and number of sectors to load kernel argument
3044 parameters from when MMC is being used in raw mode
3047 CONFIG_SPL_FAT_SUPPORT
3048 Support for fs/fat/libfat.o in SPL binary
3050 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3051 Filename to read to load U-Boot when reading from FAT
3053 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3054 Filename to read to load kernel uImage when reading
3055 from FAT (for Falcon mode)
3057 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3058 Filename to read to load kernel argument parameters
3059 when reading from FAT (for Falcon mode)
3061 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3062 Set this for NAND SPL on PPC mpc83xx targets, so that
3063 start.S waits for the rest of the SPL to load before
3064 continuing (the hardware starts execution after just
3065 loading the first page rather than the full 4K).
3067 CONFIG_SPL_NAND_BASE
3068 Include nand_base.c in the SPL. Requires
3069 CONFIG_SPL_NAND_DRIVERS.
3071 CONFIG_SPL_NAND_DRIVERS
3072 SPL uses normal NAND drivers, not minimal drivers.
3075 Include standard software ECC in the SPL
3077 CONFIG_SPL_NAND_SIMPLE
3078 Support for NAND boot using simple NAND drivers that
3079 expose the cmd_ctrl() interface.
3081 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3082 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3083 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3084 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3085 CONFIG_SYS_NAND_ECCBYTES
3086 Defines the size and behavior of the NAND that SPL uses
3089 CONFIG_SYS_NAND_U_BOOT_OFFS
3090 Location in NAND to read U-Boot from
3092 CONFIG_SYS_NAND_U_BOOT_DST
3093 Location in memory to load U-Boot to
3095 CONFIG_SYS_NAND_U_BOOT_SIZE
3096 Size of image to load
3098 CONFIG_SYS_NAND_U_BOOT_START
3099 Entry point in loaded image to jump to
3101 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3102 Define this if you need to first read the OOB and then the
3103 data. This is used for example on davinci plattforms.
3105 CONFIG_SPL_OMAP3_ID_NAND
3106 Support for an OMAP3-specific set of functions to return the
3107 ID and MFR of the first attached NAND chip, if present.
3109 CONFIG_SPL_SERIAL_SUPPORT
3110 Support for drivers/serial/libserial.o in SPL binary
3112 CONFIG_SPL_SPI_FLASH_SUPPORT
3113 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3115 CONFIG_SPL_SPI_SUPPORT
3116 Support for drivers/spi/libspi.o in SPL binary
3118 CONFIG_SPL_RAM_DEVICE
3119 Support for running image already present in ram, in SPL binary
3121 CONFIG_SPL_LIBGENERIC_SUPPORT
3122 Support for lib/libgeneric.o in SPL binary
3124 CONFIG_SPL_ENV_SUPPORT
3125 Support for the environment operating in SPL binary
3127 CONFIG_SPL_NET_SUPPORT
3128 Support for the net/libnet.o in SPL binary.
3129 It conflicts with SPL env from storage medium specified by
3130 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3133 Image offset to which the SPL should be padded before appending
3134 the SPL payload. By default, this is defined as
3135 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3136 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3137 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3140 Final target image containing SPL and payload. Some SPLs
3141 use an arch-specific makefile fragment instead, for
3142 example if more than one image needs to be produced.
3144 CONFIG_FIT_SPL_PRINT
3145 Printing information about a FIT image adds quite a bit of
3146 code to SPL. So this is normally disabled in SPL. Use this
3147 option to re-enable it. This will affect the output of the
3148 bootm command when booting a FIT image.
3153 [so far only for SMDK2400 boards]
3155 - Modem support enable:
3156 CONFIG_MODEM_SUPPORT
3158 - RTS/CTS Flow control enable:
3161 - Modem debug support:
3162 CONFIG_MODEM_SUPPORT_DEBUG
3164 Enables debugging stuff (char screen[1024], dbg())
3165 for modem support. Useful only with BDI2000.
3167 - Interrupt support (PPC):
3169 There are common interrupt_init() and timer_interrupt()
3170 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3171 for CPU specific initialization. interrupt_init_cpu()
3172 should set decrementer_count to appropriate value. If
3173 CPU resets decrementer automatically after interrupt
3174 (ppc4xx) it should set decrementer_count to zero.
3175 timer_interrupt() calls timer_interrupt_cpu() for CPU
3176 specific handling. If board has watchdog / status_led
3177 / other_activity_monitor it works automatically from
3178 general timer_interrupt().
3182 In the target system modem support is enabled when a
3183 specific key (key combination) is pressed during
3184 power-on. Otherwise U-Boot will boot normally
3185 (autoboot). The key_pressed() function is called from
3186 board_init(). Currently key_pressed() is a dummy
3187 function, returning 1 and thus enabling modem
3190 If there are no modem init strings in the
3191 environment, U-Boot proceed to autoboot; the
3192 previous output (banner, info printfs) will be
3195 See also: doc/README.Modem
3197 Board initialization settings:
3198 ------------------------------
3200 During Initialization u-boot calls a number of board specific functions
3201 to allow the preparation of board specific prerequisites, e.g. pin setup
3202 before drivers are initialized. To enable these callbacks the
3203 following configuration macros have to be defined. Currently this is
3204 architecture specific, so please check arch/your_architecture/lib/board.c
3205 typically in board_init_f() and board_init_r().
3207 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3208 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3209 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3210 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3212 Configuration Settings:
3213 -----------------------
3215 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3216 undefine this when you're short of memory.
3218 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3219 width of the commands listed in the 'help' command output.
3221 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3222 prompt for user input.
3224 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3226 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3228 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3230 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3231 the application (usually a Linux kernel) when it is
3234 - CONFIG_SYS_BAUDRATE_TABLE:
3235 List of legal baudrate settings for this board.
3237 - CONFIG_SYS_CONSOLE_INFO_QUIET
3238 Suppress display of console information at boot.
3240 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3241 If the board specific function
3242 extern int overwrite_console (void);
3243 returns 1, the stdin, stderr and stdout are switched to the
3244 serial port, else the settings in the environment are used.
3246 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3247 Enable the call to overwrite_console().
3249 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3250 Enable overwrite of previous console environment settings.
3252 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3253 Begin and End addresses of the area used by the
3256 - CONFIG_SYS_ALT_MEMTEST:
3257 Enable an alternate, more extensive memory test.
3259 - CONFIG_SYS_MEMTEST_SCRATCH:
3260 Scratch address used by the alternate memory test
3261 You only need to set this if address zero isn't writeable
3263 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3264 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3265 this specified memory area will get subtracted from the top
3266 (end) of RAM and won't get "touched" at all by U-Boot. By
3267 fixing up gd->ram_size the Linux kernel should gets passed
3268 the now "corrected" memory size and won't touch it either.
3269 This should work for arch/ppc and arch/powerpc. Only Linux
3270 board ports in arch/powerpc with bootwrapper support that
3271 recalculate the memory size from the SDRAM controller setup
3272 will have to get fixed in Linux additionally.
3274 This option can be used as a workaround for the 440EPx/GRx
3275 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3278 WARNING: Please make sure that this value is a multiple of
3279 the Linux page size (normally 4k). If this is not the case,
3280 then the end address of the Linux memory will be located at a
3281 non page size aligned address and this could cause major
3284 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3285 Enable temporary baudrate change while serial download
3287 - CONFIG_SYS_SDRAM_BASE:
3288 Physical start address of SDRAM. _Must_ be 0 here.
3290 - CONFIG_SYS_MBIO_BASE:
3291 Physical start address of Motherboard I/O (if using a
3294 - CONFIG_SYS_FLASH_BASE:
3295 Physical start address of Flash memory.
3297 - CONFIG_SYS_MONITOR_BASE:
3298 Physical start address of boot monitor code (set by
3299 make config files to be same as the text base address
3300 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3301 CONFIG_SYS_FLASH_BASE when booting from flash.
3303 - CONFIG_SYS_MONITOR_LEN:
3304 Size of memory reserved for monitor code, used to
3305 determine _at_compile_time_ (!) if the environment is
3306 embedded within the U-Boot image, or in a separate
3309 - CONFIG_SYS_MALLOC_LEN:
3310 Size of DRAM reserved for malloc() use.
3312 - CONFIG_SYS_BOOTM_LEN:
3313 Normally compressed uImages are limited to an
3314 uncompressed size of 8 MBytes. If this is not enough,
3315 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3316 to adjust this setting to your needs.
3318 - CONFIG_SYS_BOOTMAPSZ:
3319 Maximum size of memory mapped by the startup code of
3320 the Linux kernel; all data that must be processed by
3321 the Linux kernel (bd_info, boot arguments, FDT blob if
3322 used) must be put below this limit, unless "bootm_low"
3323 enviroment variable is defined and non-zero. In such case
3324 all data for the Linux kernel must be between "bootm_low"
3325 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3326 variable "bootm_mapsize" will override the value of
3327 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3328 then the value in "bootm_size" will be used instead.
3330 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3331 Enable initrd_high functionality. If defined then the
3332 initrd_high feature is enabled and the bootm ramdisk subcommand
3335 - CONFIG_SYS_BOOT_GET_CMDLINE:
3336 Enables allocating and saving kernel cmdline in space between
3337 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3339 - CONFIG_SYS_BOOT_GET_KBD:
3340 Enables allocating and saving a kernel copy of the bd_info in
3341 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3343 - CONFIG_SYS_MAX_FLASH_BANKS:
3344 Max number of Flash memory banks
3346 - CONFIG_SYS_MAX_FLASH_SECT:
3347 Max number of sectors on a Flash chip
3349 - CONFIG_SYS_FLASH_ERASE_TOUT:
3350 Timeout for Flash erase operations (in ms)
3352 - CONFIG_SYS_FLASH_WRITE_TOUT:
3353 Timeout for Flash write operations (in ms)
3355 - CONFIG_SYS_FLASH_LOCK_TOUT
3356 Timeout for Flash set sector lock bit operation (in ms)
3358 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3359 Timeout for Flash clear lock bits operation (in ms)
3361 - CONFIG_SYS_FLASH_PROTECTION
3362 If defined, hardware flash sectors protection is used
3363 instead of U-Boot software protection.
3365 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3367 Enable TFTP transfers directly to flash memory;
3368 without this option such a download has to be
3369 performed in two steps: (1) download to RAM, and (2)
3370 copy from RAM to flash.
3372 The two-step approach is usually more reliable, since
3373 you can check if the download worked before you erase
3374 the flash, but in some situations (when system RAM is
3375 too limited to allow for a temporary copy of the
3376 downloaded image) this option may be very useful.
3378 - CONFIG_SYS_FLASH_CFI:
3379 Define if the flash driver uses extra elements in the
3380 common flash structure for storing flash geometry.
3382 - CONFIG_FLASH_CFI_DRIVER
3383 This option also enables the building of the cfi_flash driver
3384 in the drivers directory
3386 - CONFIG_FLASH_CFI_MTD
3387 This option enables the building of the cfi_mtd driver
3388 in the drivers directory. The driver exports CFI flash
3391 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3392 Use buffered writes to flash.
3394 - CONFIG_FLASH_SPANSION_S29WS_N
3395 s29ws-n MirrorBit flash has non-standard addresses for buffered
3398 - CONFIG_SYS_FLASH_QUIET_TEST
3399 If this option is defined, the common CFI flash doesn't
3400 print it's warning upon not recognized FLASH banks. This
3401 is useful, if some of the configured banks are only
3402 optionally available.
3404 - CONFIG_FLASH_SHOW_PROGRESS
3405 If defined (must be an integer), print out countdown
3406 digits and dots. Recommended value: 45 (9..1) for 80
3407 column displays, 15 (3..1) for 40 column displays.
3409 - CONFIG_FLASH_VERIFY
3410 If defined, the content of the flash (destination) is compared
3411 against the source after the write operation. An error message
3412 will be printed when the contents are not identical.
3413 Please note that this option is useless in nearly all cases,
3414 since such flash programming errors usually are detected earlier
3415 while unprotecting/erasing/programming. Please only enable
3416 this option if you really know what you are doing.
3418 - CONFIG_SYS_RX_ETH_BUFFER:
3419 Defines the number of Ethernet receive buffers. On some
3420 Ethernet controllers it is recommended to set this value
3421 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3422 buffers can be full shortly after enabling the interface
3423 on high Ethernet traffic.
3424 Defaults to 4 if not defined.
3426 - CONFIG_ENV_MAX_ENTRIES
3428 Maximum number of entries in the hash table that is used
3429 internally to store the environment settings. The default
3430 setting is supposed to be generous and should work in most
3431 cases. This setting can be used to tune behaviour; see
3432 lib/hashtable.c for details.
3434 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3435 - CONFIG_ENV_FLAGS_LIST_STATIC
3436 Enable validation of the values given to enviroment variables when
3437 calling env set. Variables can be restricted to only decimal,
3438 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3439 the variables can also be restricted to IP address or MAC address.
3441 The format of the list is:
3442 type_attribute = [s|d|x|b|i|m]
3443 access_atribute = [a|r|o|c]
3444 attributes = type_attribute[access_atribute]
3445 entry = variable_name[:attributes]
3448 The type attributes are:
3449 s - String (default)
3452 b - Boolean ([1yYtT|0nNfF])
3456 The access attributes are:
3462 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3463 Define this to a list (string) to define the ".flags"
3464 envirnoment variable in the default or embedded environment.
3466 - CONFIG_ENV_FLAGS_LIST_STATIC
3467 Define this to a list (string) to define validation that
3468 should be done if an entry is not found in the ".flags"
3469 environment variable. To override a setting in the static
3470 list, simply add an entry for the same variable name to the
3473 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3474 If defined, don't allow the -f switch to env set override variable
3477 - CONFIG_SYS_GENERIC_BOARD
3478 This selects the architecture-generic board system instead of the
3479 architecture-specific board files. It is intended to move boards
3480 to this new framework over time. Defining this will disable the
3481 arch/foo/lib/board.c file and use common/board_f.c and
3482 common/board_r.c instead. To use this option your architecture
3483 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3484 its config.mk file). If you find problems enabling this option on
3485 your board please report the problem and send patches!
3487 - CONFIG_SYS_SYM_OFFSETS
3488 This is set by architectures that use offsets for link symbols
3489 instead of absolute values. So bss_start is obtained using an
3490 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3491 directly. You should not need to touch this setting.
3493 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3494 This is set by OMAP boards for the max time that reset should
3495 be asserted. See doc/README.omap-reset-time for details on how
3496 the value can be calulated on a given board.
3498 The following definitions that deal with the placement and management
3499 of environment data (variable area); in general, we support the
3500 following configurations:
3502 - CONFIG_BUILD_ENVCRC:
3504 Builds up envcrc with the target environment so that external utils
3505 may easily extract it and embed it in final U-Boot images.
3507 - CONFIG_ENV_IS_IN_FLASH:
3509 Define this if the environment is in flash memory.
3511 a) The environment occupies one whole flash sector, which is
3512 "embedded" in the text segment with the U-Boot code. This
3513 happens usually with "bottom boot sector" or "top boot
3514 sector" type flash chips, which have several smaller
3515 sectors at the start or the end. For instance, such a
3516 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3517 such a case you would place the environment in one of the
3518 4 kB sectors - with U-Boot code before and after it. With
3519 "top boot sector" type flash chips, you would put the
3520 environment in one of the last sectors, leaving a gap
3521 between U-Boot and the environment.
3523 - CONFIG_ENV_OFFSET:
3525 Offset of environment data (variable area) to the
3526 beginning of flash memory; for instance, with bottom boot
3527 type flash chips the second sector can be used: the offset
3528 for this sector is given here.
3530 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3534 This is just another way to specify the start address of
3535 the flash sector containing the environment (instead of
3538 - CONFIG_ENV_SECT_SIZE:
3540 Size of the sector containing the environment.
3543 b) Sometimes flash chips have few, equal sized, BIG sectors.
3544 In such a case you don't want to spend a whole sector for
3549 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3550 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3551 of this flash sector for the environment. This saves
3552 memory for the RAM copy of the environment.
3554 It may also save flash memory if you decide to use this
3555 when your environment is "embedded" within U-Boot code,
3556 since then the remainder of the flash sector could be used
3557 for U-Boot code. It should be pointed out that this is
3558 STRONGLY DISCOURAGED from a robustness point of view:
3559 updating the environment in flash makes it always
3560 necessary to erase the WHOLE sector. If something goes
3561 wrong before the contents has been restored from a copy in
3562 RAM, your target system will be dead.
3564 - CONFIG_ENV_ADDR_REDUND
3565 CONFIG_ENV_SIZE_REDUND
3567 These settings describe a second storage area used to hold
3568 a redundant copy of the environment data, so that there is
3569 a valid backup copy in case there is a power failure during
3570 a "saveenv" operation.
3572 BE CAREFUL! Any changes to the flash layout, and some changes to the
3573 source code will make it necessary to adapt <board>/u-boot.lds*
3577 - CONFIG_ENV_IS_IN_NVRAM:
3579 Define this if you have some non-volatile memory device
3580 (NVRAM, battery buffered SRAM) which you want to use for the
3586 These two #defines are used to determine the memory area you
3587 want to use for environment. It is assumed that this memory
3588 can just be read and written to, without any special
3591 BE CAREFUL! The first access to the environment happens quite early
3592 in U-Boot initalization (when we try to get the setting of for the
3593 console baudrate). You *MUST* have mapped your NVRAM area then, or
3596 Please note that even with NVRAM we still use a copy of the
3597 environment in RAM: we could work on NVRAM directly, but we want to
3598 keep settings there always unmodified except somebody uses "saveenv"
3599 to save the current settings.
3602 - CONFIG_ENV_IS_IN_EEPROM:
3604 Use this if you have an EEPROM or similar serial access
3605 device and a driver for it.
3607 - CONFIG_ENV_OFFSET:
3610 These two #defines specify the offset and size of the
3611 environment area within the total memory of your EEPROM.
3613 - CONFIG_SYS_I2C_EEPROM_ADDR:
3614 If defined, specified the chip address of the EEPROM device.
3615 The default address is zero.
3617 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3618 If defined, the number of bits used to address bytes in a
3619 single page in the EEPROM device. A 64 byte page, for example
3620 would require six bits.
3622 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3623 If defined, the number of milliseconds to delay between
3624 page writes. The default is zero milliseconds.
3626 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3627 The length in bytes of the EEPROM memory array address. Note
3628 that this is NOT the chip address length!
3630 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3631 EEPROM chips that implement "address overflow" are ones
3632 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3633 address and the extra bits end up in the "chip address" bit
3634 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3637 Note that we consider the length of the address field to
3638 still be one byte because the extra address bits are hidden
3639 in the chip address.
3641 - CONFIG_SYS_EEPROM_SIZE:
3642 The size in bytes of the EEPROM device.
3644 - CONFIG_ENV_EEPROM_IS_ON_I2C
3645 define this, if you have I2C and SPI activated, and your
3646 EEPROM, which holds the environment, is on the I2C bus.
3648 - CONFIG_I2C_ENV_EEPROM_BUS
3649 if you have an Environment on an EEPROM reached over
3650 I2C muxes, you can define here, how to reach this
3651 EEPROM. For example:
3653 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3655 EEPROM which holds the environment, is reached over
3656 a pca9547 i2c mux with address 0x70, channel 3.
3658 - CONFIG_ENV_IS_IN_DATAFLASH:
3660 Define this if you have a DataFlash memory device which you
3661 want to use for the environment.
3663 - CONFIG_ENV_OFFSET:
3667 These three #defines specify the offset and size of the
3668 environment area within the total memory of your DataFlash placed
3669 at the specified address.
3671 - CONFIG_ENV_IS_IN_REMOTE:
3673 Define this if you have a remote memory space which you
3674 want to use for the local device's environment.
3679 These two #defines specify the address and size of the
3680 environment area within the remote memory space. The
3681 local device can get the environment from remote memory
3682 space by SRIO or PCIE links.
3684 BE CAREFUL! For some special cases, the local device can not use
3685 "saveenv" command. For example, the local device will get the
3686 environment stored in a remote NOR flash by SRIO or PCIE link,
3687 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3689 - CONFIG_ENV_IS_IN_NAND:
3691 Define this if you have a NAND device which you want to use
3692 for the environment.
3694 - CONFIG_ENV_OFFSET:
3697 These two #defines specify the offset and size of the environment
3698 area within the first NAND device. CONFIG_ENV_OFFSET must be
3699 aligned to an erase block boundary.
3701 - CONFIG_ENV_OFFSET_REDUND (optional):
3703 This setting describes a second storage area of CONFIG_ENV_SIZE
3704 size used to hold a redundant copy of the environment data, so
3705 that there is a valid backup copy in case there is a power failure
3706 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3707 aligned to an erase block boundary.
3709 - CONFIG_ENV_RANGE (optional):
3711 Specifies the length of the region in which the environment
3712 can be written. This should be a multiple of the NAND device's
3713 block size. Specifying a range with more erase blocks than
3714 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3715 the range to be avoided.
3717 - CONFIG_ENV_OFFSET_OOB (optional):
3719 Enables support for dynamically retrieving the offset of the
3720 environment from block zero's out-of-band data. The
3721 "nand env.oob" command can be used to record this offset.
3722 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3723 using CONFIG_ENV_OFFSET_OOB.
3725 - CONFIG_NAND_ENV_DST
3727 Defines address in RAM to which the nand_spl code should copy the
3728 environment. If redundant environment is used, it will be copied to
3729 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3731 - CONFIG_ENV_IS_IN_UBI:
3733 Define this if you have an UBI volume that you want to use for the
3734 environment. This has the benefit of wear-leveling the environment
3735 accesses, which is important on NAND.
3737 - CONFIG_ENV_UBI_PART:
3739 Define this to a string that is the mtd partition containing the UBI.
3741 - CONFIG_ENV_UBI_VOLUME:
3743 Define this to the name of the volume that you want to store the
3746 - CONFIG_ENV_UBI_VOLUME_REDUND:
3748 Define this to the name of another volume to store a second copy of
3749 the environment in. This will enable redundant environments in UBI.
3750 It is assumed that both volumes are in the same MTD partition.
3752 - CONFIG_UBI_SILENCE_MSG
3753 - CONFIG_UBIFS_SILENCE_MSG
3755 You will probably want to define these to avoid a really noisy system
3756 when storing the env in UBI.
3758 - CONFIG_ENV_IS_IN_MMC:
3760 Define this if you have an MMC device which you want to use for the
3763 - CONFIG_SYS_MMC_ENV_DEV:
3765 Specifies which MMC device the environment is stored in.
3767 - CONFIG_SYS_MMC_ENV_PART (optional):
3769 Specifies which MMC partition the environment is stored in. If not
3770 set, defaults to partition 0, the user area. Common values might be
3771 1 (first MMC boot partition), 2 (second MMC boot partition).
3773 - CONFIG_ENV_OFFSET:
3776 These two #defines specify the offset and size of the environment
3777 area within the specified MMC device.
3779 If offset is positive (the usual case), it is treated as relative to
3780 the start of the MMC partition. If offset is negative, it is treated
3781 as relative to the end of the MMC partition. This can be useful if
3782 your board may be fitted with different MMC devices, which have
3783 different sizes for the MMC partitions, and you always want the
3784 environment placed at the very end of the partition, to leave the
3785 maximum possible space before it, to store other data.
3787 These two values are in units of bytes, but must be aligned to an
3788 MMC sector boundary.
3790 - CONFIG_ENV_OFFSET_REDUND (optional):
3792 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3793 hold a redundant copy of the environment data. This provides a
3794 valid backup copy in case the other copy is corrupted, e.g. due
3795 to a power failure during a "saveenv" operation.
3797 This value may also be positive or negative; this is handled in the
3798 same way as CONFIG_ENV_OFFSET.
3800 This value is also in units of bytes, but must also be aligned to
3801 an MMC sector boundary.
3803 - CONFIG_ENV_SIZE_REDUND (optional):
3805 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3806 set. If this value is set, it must be set to the same value as
3809 - CONFIG_SYS_SPI_INIT_OFFSET
3811 Defines offset to the initial SPI buffer area in DPRAM. The
3812 area is used at an early stage (ROM part) if the environment
3813 is configured to reside in the SPI EEPROM: We need a 520 byte
3814 scratch DPRAM area. It is used between the two initialization
3815 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3816 to be a good choice since it makes it far enough from the
3817 start of the data area as well as from the stack pointer.
3819 Please note that the environment is read-only until the monitor
3820 has been relocated to RAM and a RAM copy of the environment has been
3821 created; also, when using EEPROM you will have to use getenv_f()
3822 until then to read environment variables.
3824 The environment is protected by a CRC32 checksum. Before the monitor
3825 is relocated into RAM, as a result of a bad CRC you will be working
3826 with the compiled-in default environment - *silently*!!! [This is
3827 necessary, because the first environment variable we need is the
3828 "baudrate" setting for the console - if we have a bad CRC, we don't
3829 have any device yet where we could complain.]
3831 Note: once the monitor has been relocated, then it will complain if
3832 the default environment is used; a new CRC is computed as soon as you
3833 use the "saveenv" command to store a valid environment.
3835 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3836 Echo the inverted Ethernet link state to the fault LED.
3838 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3839 also needs to be defined.
3841 - CONFIG_SYS_FAULT_MII_ADDR:
3842 MII address of the PHY to check for the Ethernet link state.
3844 - CONFIG_NS16550_MIN_FUNCTIONS:
3845 Define this if you desire to only have use of the NS16550_init
3846 and NS16550_putc functions for the serial driver located at
3847 drivers/serial/ns16550.c. This option is useful for saving
3848 space for already greatly restricted images, including but not
3849 limited to NAND_SPL configurations.
3851 - CONFIG_DISPLAY_BOARDINFO
3852 Display information about the board that U-Boot is running on
3853 when U-Boot starts up. The board function checkboard() is called
3856 - CONFIG_DISPLAY_BOARDINFO_LATE
3857 Similar to the previous option, but display this information
3858 later, once stdio is running and output goes to the LCD, if
3861 Low Level (hardware related) configuration options:
3862 ---------------------------------------------------
3864 - CONFIG_SYS_CACHELINE_SIZE:
3865 Cache Line Size of the CPU.
3867 - CONFIG_SYS_DEFAULT_IMMR:
3868 Default address of the IMMR after system reset.
3870 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3871 and RPXsuper) to be able to adjust the position of
3872 the IMMR register after a reset.
3874 - CONFIG_SYS_CCSRBAR_DEFAULT:
3875 Default (power-on reset) physical address of CCSR on Freescale
3878 - CONFIG_SYS_CCSRBAR:
3879 Virtual address of CCSR. On a 32-bit build, this is typically
3880 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3882 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3883 for cross-platform code that uses that macro instead.
3885 - CONFIG_SYS_CCSRBAR_PHYS:
3886 Physical address of CCSR. CCSR can be relocated to a new
3887 physical address, if desired. In this case, this macro should
3888 be set to that address. Otherwise, it should be set to the
3889 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3890 is typically relocated on 36-bit builds. It is recommended
3891 that this macro be defined via the _HIGH and _LOW macros:
3893 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3894 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3896 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3897 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3898 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3899 used in assembly code, so it must not contain typecasts or
3900 integer size suffixes (e.g. "ULL").
3902 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3903 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3904 used in assembly code, so it must not contain typecasts or
3905 integer size suffixes (e.g. "ULL").
3907 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3908 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3909 forced to a value that ensures that CCSR is not relocated.
3911 - Floppy Disk Support:
3912 CONFIG_SYS_FDC_DRIVE_NUMBER
3914 the default drive number (default value 0)
3916 CONFIG_SYS_ISA_IO_STRIDE
3918 defines the spacing between FDC chipset registers
3921 CONFIG_SYS_ISA_IO_OFFSET
3923 defines the offset of register from address. It
3924 depends on which part of the data bus is connected to
3925 the FDC chipset. (default value 0)
3927 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3928 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3931 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3932 fdc_hw_init() is called at the beginning of the FDC
3933 setup. fdc_hw_init() must be provided by the board
3934 source code. It is used to make hardware dependant
3938 Most IDE controllers were designed to be connected with PCI
3939 interface. Only few of them were designed for AHB interface.
3940 When software is doing ATA command and data transfer to
3941 IDE devices through IDE-AHB controller, some additional
3942 registers accessing to these kind of IDE-AHB controller
3945 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3946 DO NOT CHANGE unless you know exactly what you're
3947 doing! (11-4) [MPC8xx/82xx systems only]
3949 - CONFIG_SYS_INIT_RAM_ADDR:
3951 Start address of memory area that can be used for
3952 initial data and stack; please note that this must be
3953 writable memory that is working WITHOUT special
3954 initialization, i. e. you CANNOT use normal RAM which
3955 will become available only after programming the
3956 memory controller and running certain initialization
3959 U-Boot uses the following memory types:
3960 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3961 - MPC824X: data cache
3962 - PPC4xx: data cache
3964 - CONFIG_SYS_GBL_DATA_OFFSET:
3966 Offset of the initial data structure in the memory
3967 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3968 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3969 data is located at the end of the available space
3970 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3971 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3972 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3973 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3976 On the MPC824X (or other systems that use the data
3977 cache for initial memory) the address chosen for
3978 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3979 point to an otherwise UNUSED address space between
3980 the top of RAM and the start of the PCI space.
3982 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3984 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3986 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3988 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3990 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3992 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3994 - CONFIG_SYS_OR_TIMING_SDRAM:
3997 - CONFIG_SYS_MAMR_PTA:
3998 periodic timer for refresh
4000 - CONFIG_SYS_DER: Debug Event Register (37-47)
4002 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4003 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4004 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4005 CONFIG_SYS_BR1_PRELIM:
4006 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4008 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4009 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4010 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4011 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4013 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4014 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4015 Machine Mode Register and Memory Periodic Timer
4016 Prescaler definitions (SDRAM timing)
4018 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4019 enable I2C microcode relocation patch (MPC8xx);
4020 define relocation offset in DPRAM [DSP2]
4022 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4023 enable SMC microcode relocation patch (MPC8xx);
4024 define relocation offset in DPRAM [SMC1]
4026 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4027 enable SPI microcode relocation patch (MPC8xx);
4028 define relocation offset in DPRAM [SCC4]
4030 - CONFIG_SYS_USE_OSCCLK:
4031 Use OSCM clock mode on MBX8xx board. Be careful,
4032 wrong setting might damage your board. Read
4033 doc/README.MBX before setting this variable!
4035 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4036 Offset of the bootmode word in DPRAM used by post
4037 (Power On Self Tests). This definition overrides
4038 #define'd default value in commproc.h resp.
4041 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4042 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4043 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4044 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4045 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4046 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4047 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4048 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4049 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4051 - CONFIG_PCI_DISABLE_PCIE:
4052 Disable PCI-Express on systems where it is supported but not
4055 - CONFIG_PCI_ENUM_ONLY
4056 Only scan through and get the devices on the busses.
4057 Don't do any setup work, presumably because someone or
4058 something has already done it, and we don't need to do it
4059 a second time. Useful for platforms that are pre-booted
4060 by coreboot or similar.
4062 - CONFIG_PCI_INDIRECT_BRIDGE:
4063 Enable support for indirect PCI bridges.
4066 Chip has SRIO or not
4069 Board has SRIO 1 port available
4072 Board has SRIO 2 port available
4074 - CONFIG_SRIO_PCIE_BOOT_MASTER
4075 Board can support master function for Boot from SRIO and PCIE
4077 - CONFIG_SYS_SRIOn_MEM_VIRT:
4078 Virtual Address of SRIO port 'n' memory region
4080 - CONFIG_SYS_SRIOn_MEM_PHYS:
4081 Physical Address of SRIO port 'n' memory region
4083 - CONFIG_SYS_SRIOn_MEM_SIZE:
4084 Size of SRIO port 'n' memory region
4086 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4087 Defined to tell the NAND controller that the NAND chip is using
4089 Not all NAND drivers use this symbol.
4090 Example of drivers that use it:
4091 - drivers/mtd/nand/ndfc.c
4092 - drivers/mtd/nand/mxc_nand.c
4094 - CONFIG_SYS_NDFC_EBC0_CFG
4095 Sets the EBC0_CFG register for the NDFC. If not defined
4096 a default value will be used.
4099 Get DDR timing information from an I2C EEPROM. Common
4100 with pluggable memory modules such as SODIMMs
4103 I2C address of the SPD EEPROM
4105 - CONFIG_SYS_SPD_BUS_NUM
4106 If SPD EEPROM is on an I2C bus other than the first
4107 one, specify here. Note that the value must resolve
4108 to something your driver can deal with.
4110 - CONFIG_SYS_DDR_RAW_TIMING
4111 Get DDR timing information from other than SPD. Common with
4112 soldered DDR chips onboard without SPD. DDR raw timing
4113 parameters are extracted from datasheet and hard-coded into
4114 header files or board specific files.
4116 - CONFIG_FSL_DDR_INTERACTIVE
4117 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4119 - CONFIG_SYS_83XX_DDR_USES_CS0
4120 Only for 83xx systems. If specified, then DDR should
4121 be configured using CS0 and CS1 instead of CS2 and CS3.
4123 - CONFIG_ETHER_ON_FEC[12]
4124 Define to enable FEC[12] on a 8xx series processor.
4126 - CONFIG_FEC[12]_PHY
4127 Define to the hardcoded PHY address which corresponds
4128 to the given FEC; i. e.
4129 #define CONFIG_FEC1_PHY 4
4130 means that the PHY with address 4 is connected to FEC1
4132 When set to -1, means to probe for first available.
4134 - CONFIG_FEC[12]_PHY_NORXERR
4135 The PHY does not have a RXERR line (RMII only).
4136 (so program the FEC to ignore it).
4139 Enable RMII mode for all FECs.
4140 Note that this is a global option, we can't
4141 have one FEC in standard MII mode and another in RMII mode.
4143 - CONFIG_CRC32_VERIFY
4144 Add a verify option to the crc32 command.
4147 => crc32 -v <address> <count> <crc32>
4149 Where address/count indicate a memory area
4150 and crc32 is the correct crc32 which the
4154 Add the "loopw" memory command. This only takes effect if
4155 the memory commands are activated globally (CONFIG_CMD_MEM).
4158 Add the "mdc" and "mwc" memory commands. These are cyclic
4163 This command will print 4 bytes (10,11,12,13) each 500 ms.
4165 => mwc.l 100 12345678 10
4166 This command will write 12345678 to address 100 all 10 ms.
4168 This only takes effect if the memory commands are activated
4169 globally (CONFIG_CMD_MEM).
4171 - CONFIG_SKIP_LOWLEVEL_INIT
4172 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4173 low level initializations (like setting up the memory
4174 controller) are omitted and/or U-Boot does not
4175 relocate itself into RAM.
4177 Normally this variable MUST NOT be defined. The only
4178 exception is when U-Boot is loaded (to RAM) by some
4179 other boot loader or by a debugger which performs
4180 these initializations itself.
4183 Modifies the behaviour of start.S when compiling a loader
4184 that is executed before the actual U-Boot. E.g. when
4185 compiling a NAND SPL.
4187 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4188 Only for 85xx systems. If this variable is specified, the section
4189 .resetvec is not kept and the section .bootpg is placed in the
4190 previous 4k of the .text section.
4192 - CONFIG_ARCH_MAP_SYSMEM
4193 Generally U-Boot (and in particular the md command) uses
4194 effective address. It is therefore not necessary to regard
4195 U-Boot address as virtual addresses that need to be translated
4196 to physical addresses. However, sandbox requires this, since
4197 it maintains its own little RAM buffer which contains all
4198 addressable memory. This option causes some memory accesses
4199 to be mapped through map_sysmem() / unmap_sysmem().
4201 - CONFIG_USE_ARCH_MEMCPY
4202 CONFIG_USE_ARCH_MEMSET
4203 If these options are used a optimized version of memcpy/memset will
4204 be used if available. These functions may be faster under some
4205 conditions but may increase the binary size.
4207 - CONFIG_X86_RESET_VECTOR
4208 If defined, the x86 reset vector code is included. This is not
4209 needed when U-Boot is running from Coreboot.
4212 Defines the MPU clock speed (in MHz).
4214 NOTE : currently only supported on AM335x platforms.
4216 Freescale QE/FMAN Firmware Support:
4217 -----------------------------------
4219 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4220 loading of "firmware", which is encoded in the QE firmware binary format.
4221 This firmware often needs to be loaded during U-Boot booting, so macros
4222 are used to identify the storage device (NOR flash, SPI, etc) and the address
4225 - CONFIG_SYS_QE_FMAN_FW_ADDR
4226 The address in the storage device where the firmware is located. The
4227 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4230 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4231 The maximum possible size of the firmware. The firmware binary format
4232 has a field that specifies the actual size of the firmware, but it
4233 might not be possible to read any part of the firmware unless some
4234 local storage is allocated to hold the entire firmware first.
4236 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4237 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4238 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4239 virtual address in NOR flash.
4241 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4242 Specifies that QE/FMAN firmware is located in NAND flash.
4243 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4245 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4246 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4247 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4249 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4250 Specifies that QE/FMAN firmware is located on the primary SPI
4251 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4253 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4254 Specifies that QE/FMAN firmware is located in the remote (master)
4255 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4256 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4257 window->master inbound window->master LAW->the ucode address in
4258 master's memory space.
4260 Building the Software:
4261 ======================
4263 Building U-Boot has been tested in several native build environments
4264 and in many different cross environments. Of course we cannot support
4265 all possibly existing versions of cross development tools in all
4266 (potentially obsolete) versions. In case of tool chain problems we
4267 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4268 which is extensively used to build and test U-Boot.
4270 If you are not using a native environment, it is assumed that you
4271 have GNU cross compiling tools available in your path. In this case,
4272 you must set the environment variable CROSS_COMPILE in your shell.
4273 Note that no changes to the Makefile or any other source files are
4274 necessary. For example using the ELDK on a 4xx CPU, please enter:
4276 $ CROSS_COMPILE=ppc_4xx-
4277 $ export CROSS_COMPILE
4279 Note: If you wish to generate Windows versions of the utilities in
4280 the tools directory you can use the MinGW toolchain
4281 (http://www.mingw.org). Set your HOST tools to the MinGW
4282 toolchain and execute 'make tools'. For example:
4284 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4286 Binaries such as tools/mkimage.exe will be created which can
4287 be executed on computers running Windows.
4289 U-Boot is intended to be simple to build. After installing the
4290 sources you must configure U-Boot for one specific board type. This
4295 where "NAME_config" is the name of one of the existing configu-
4296 rations; see boards.cfg for supported names.
4298 Note: for some board special configuration names may exist; check if
4299 additional information is available from the board vendor; for
4300 instance, the TQM823L systems are available without (standard)
4301 or with LCD support. You can select such additional "features"
4302 when choosing the configuration, i. e.
4305 - will configure for a plain TQM823L, i. e. no LCD support
4307 make TQM823L_LCD_config
4308 - will configure for a TQM823L with U-Boot console on LCD
4313 Finally, type "make all", and you should get some working U-Boot
4314 images ready for download to / installation on your system:
4316 - "u-boot.bin" is a raw binary image
4317 - "u-boot" is an image in ELF binary format
4318 - "u-boot.srec" is in Motorola S-Record format
4320 By default the build is performed locally and the objects are saved
4321 in the source directory. One of the two methods can be used to change
4322 this behavior and build U-Boot to some external directory:
4324 1. Add O= to the make command line invocations:
4326 make O=/tmp/build distclean
4327 make O=/tmp/build NAME_config
4328 make O=/tmp/build all
4330 2. Set environment variable BUILD_DIR to point to the desired location:
4332 export BUILD_DIR=/tmp/build
4337 Note that the command line "O=" setting overrides the BUILD_DIR environment
4341 Please be aware that the Makefiles assume you are using GNU make, so
4342 for instance on NetBSD you might need to use "gmake" instead of
4346 If the system board that you have is not listed, then you will need
4347 to port U-Boot to your hardware platform. To do this, follow these
4350 1. Add a new configuration option for your board to the toplevel
4351 "boards.cfg" file, using the existing entries as examples.
4352 Follow the instructions there to keep the boards in order.
4353 2. Create a new directory to hold your board specific code. Add any
4354 files you need. In your board directory, you will need at least
4355 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4356 3. Create a new configuration file "include/configs/<board>.h" for
4358 3. If you're porting U-Boot to a new CPU, then also create a new
4359 directory to hold your CPU specific code. Add any files you need.
4360 4. Run "make <board>_config" with your new name.
4361 5. Type "make", and you should get a working "u-boot.srec" file
4362 to be installed on your target system.
4363 6. Debug and solve any problems that might arise.
4364 [Of course, this last step is much harder than it sounds.]
4367 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4368 ==============================================================
4370 If you have modified U-Boot sources (for instance added a new board
4371 or support for new devices, a new CPU, etc.) you are expected to
4372 provide feedback to the other developers. The feedback normally takes
4373 the form of a "patch", i. e. a context diff against a certain (latest
4374 official or latest in the git repository) version of U-Boot sources.
4376 But before you submit such a patch, please verify that your modifi-
4377 cation did not break existing code. At least make sure that *ALL* of
4378 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4379 just run the "MAKEALL" script, which will configure and build U-Boot
4380 for ALL supported system. Be warned, this will take a while. You can
4381 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4382 environment variable to the script, i. e. to use the ELDK cross tools
4385 CROSS_COMPILE=ppc_8xx- MAKEALL
4387 or to build on a native PowerPC system you can type
4389 CROSS_COMPILE=' ' MAKEALL
4391 When using the MAKEALL script, the default behaviour is to build
4392 U-Boot in the source directory. This location can be changed by
4393 setting the BUILD_DIR environment variable. Also, for each target
4394 built, the MAKEALL script saves two log files (<target>.ERR and
4395 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4396 location can be changed by setting the MAKEALL_LOGDIR environment
4397 variable. For example:
4399 export BUILD_DIR=/tmp/build
4400 export MAKEALL_LOGDIR=/tmp/log
4401 CROSS_COMPILE=ppc_8xx- MAKEALL
4403 With the above settings build objects are saved in the /tmp/build,
4404 log files are saved in the /tmp/log and the source tree remains clean
4405 during the whole build process.
4408 See also "U-Boot Porting Guide" below.
4411 Monitor Commands - Overview:
4412 ============================
4414 go - start application at address 'addr'
4415 run - run commands in an environment variable
4416 bootm - boot application image from memory
4417 bootp - boot image via network using BootP/TFTP protocol
4418 bootz - boot zImage from memory
4419 tftpboot- boot image via network using TFTP protocol
4420 and env variables "ipaddr" and "serverip"
4421 (and eventually "gatewayip")
4422 tftpput - upload a file via network using TFTP protocol
4423 rarpboot- boot image via network using RARP/TFTP protocol
4424 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4425 loads - load S-Record file over serial line
4426 loadb - load binary file over serial line (kermit mode)
4428 mm - memory modify (auto-incrementing)
4429 nm - memory modify (constant address)
4430 mw - memory write (fill)
4432 cmp - memory compare
4433 crc32 - checksum calculation
4434 i2c - I2C sub-system
4435 sspi - SPI utility commands
4436 base - print or set address offset
4437 printenv- print environment variables
4438 setenv - set environment variables
4439 saveenv - save environment variables to persistent storage
4440 protect - enable or disable FLASH write protection
4441 erase - erase FLASH memory
4442 flinfo - print FLASH memory information
4443 nand - NAND memory operations (see doc/README.nand)
4444 bdinfo - print Board Info structure
4445 iminfo - print header information for application image
4446 coninfo - print console devices and informations
4447 ide - IDE sub-system
4448 loop - infinite loop on address range
4449 loopw - infinite write loop on address range
4450 mtest - simple RAM test
4451 icache - enable or disable instruction cache
4452 dcache - enable or disable data cache
4453 reset - Perform RESET of the CPU
4454 echo - echo args to console
4455 version - print monitor version
4456 help - print online help
4457 ? - alias for 'help'
4460 Monitor Commands - Detailed Description:
4461 ========================================
4465 For now: just type "help <command>".
4468 Environment Variables:
4469 ======================
4471 U-Boot supports user configuration using Environment Variables which
4472 can be made persistent by saving to Flash memory.
4474 Environment Variables are set using "setenv", printed using
4475 "printenv", and saved to Flash using "saveenv". Using "setenv"
4476 without a value can be used to delete a variable from the
4477 environment. As long as you don't save the environment you are
4478 working with an in-memory copy. In case the Flash area containing the
4479 environment is erased by accident, a default environment is provided.
4481 Some configuration options can be set using Environment Variables.
4483 List of environment variables (most likely not complete):
4485 baudrate - see CONFIG_BAUDRATE
4487 bootdelay - see CONFIG_BOOTDELAY
4489 bootcmd - see CONFIG_BOOTCOMMAND
4491 bootargs - Boot arguments when booting an RTOS image
4493 bootfile - Name of the image to load with TFTP
4495 bootm_low - Memory range available for image processing in the bootm
4496 command can be restricted. This variable is given as
4497 a hexadecimal number and defines lowest address allowed
4498 for use by the bootm command. See also "bootm_size"
4499 environment variable. Address defined by "bootm_low" is
4500 also the base of the initial memory mapping for the Linux
4501 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4504 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4505 This variable is given as a hexadecimal number and it
4506 defines the size of the memory region starting at base
4507 address bootm_low that is accessible by the Linux kernel
4508 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4509 as the default value if it is defined, and bootm_size is
4512 bootm_size - Memory range available for image processing in the bootm
4513 command can be restricted. This variable is given as
4514 a hexadecimal number and defines the size of the region
4515 allowed for use by the bootm command. See also "bootm_low"
4516 environment variable.
4518 updatefile - Location of the software update file on a TFTP server, used
4519 by the automatic software update feature. Please refer to
4520 documentation in doc/README.update for more details.
4522 autoload - if set to "no" (any string beginning with 'n'),
4523 "bootp" will just load perform a lookup of the
4524 configuration from the BOOTP server, but not try to
4525 load any image using TFTP
4527 autostart - if set to "yes", an image loaded using the "bootp",
4528 "rarpboot", "tftpboot" or "diskboot" commands will
4529 be automatically started (by internally calling
4532 If set to "no", a standalone image passed to the
4533 "bootm" command will be copied to the load address
4534 (and eventually uncompressed), but NOT be started.
4535 This can be used to load and uncompress arbitrary
4538 fdt_high - if set this restricts the maximum address that the
4539 flattened device tree will be copied into upon boot.
4540 For example, if you have a system with 1 GB memory
4541 at physical address 0x10000000, while Linux kernel
4542 only recognizes the first 704 MB as low memory, you
4543 may need to set fdt_high as 0x3C000000 to have the
4544 device tree blob be copied to the maximum address
4545 of the 704 MB low memory, so that Linux kernel can
4546 access it during the boot procedure.
4548 If this is set to the special value 0xFFFFFFFF then
4549 the fdt will not be copied at all on boot. For this
4550 to work it must reside in writable memory, have
4551 sufficient padding on the end of it for u-boot to
4552 add the information it needs into it, and the memory
4553 must be accessible by the kernel.
4555 fdtcontroladdr- if set this is the address of the control flattened
4556 device tree used by U-Boot when CONFIG_OF_CONTROL is
4559 i2cfast - (PPC405GP|PPC405EP only)
4560 if set to 'y' configures Linux I2C driver for fast
4561 mode (400kHZ). This environment variable is used in
4562 initialization code. So, for changes to be effective
4563 it must be saved and board must be reset.
4565 initrd_high - restrict positioning of initrd images:
4566 If this variable is not set, initrd images will be
4567 copied to the highest possible address in RAM; this
4568 is usually what you want since it allows for
4569 maximum initrd size. If for some reason you want to
4570 make sure that the initrd image is loaded below the
4571 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4572 variable to a value of "no" or "off" or "0".
4573 Alternatively, you can set it to a maximum upper
4574 address to use (U-Boot will still check that it
4575 does not overwrite the U-Boot stack and data).
4577 For instance, when you have a system with 16 MB
4578 RAM, and want to reserve 4 MB from use by Linux,
4579 you can do this by adding "mem=12M" to the value of
4580 the "bootargs" variable. However, now you must make
4581 sure that the initrd image is placed in the first
4582 12 MB as well - this can be done with
4584 setenv initrd_high 00c00000
4586 If you set initrd_high to 0xFFFFFFFF, this is an
4587 indication to U-Boot that all addresses are legal
4588 for the Linux kernel, including addresses in flash
4589 memory. In this case U-Boot will NOT COPY the
4590 ramdisk at all. This may be useful to reduce the
4591 boot time on your system, but requires that this
4592 feature is supported by your Linux kernel.
4594 ipaddr - IP address; needed for tftpboot command
4596 loadaddr - Default load address for commands like "bootp",
4597 "rarpboot", "tftpboot", "loadb" or "diskboot"
4599 loads_echo - see CONFIG_LOADS_ECHO
4601 serverip - TFTP server IP address; needed for tftpboot command
4603 bootretry - see CONFIG_BOOT_RETRY_TIME
4605 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4607 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4609 ethprime - controls which interface is used first.
4611 ethact - controls which interface is currently active.
4612 For example you can do the following
4614 => setenv ethact FEC
4615 => ping 192.168.0.1 # traffic sent on FEC
4616 => setenv ethact SCC
4617 => ping 10.0.0.1 # traffic sent on SCC
4619 ethrotate - When set to "no" U-Boot does not go through all
4620 available network interfaces.
4621 It just stays at the currently selected interface.
4623 netretry - When set to "no" each network operation will
4624 either succeed or fail without retrying.
4625 When set to "once" the network operation will
4626 fail when all the available network interfaces
4627 are tried once without success.
4628 Useful on scripts which control the retry operation
4631 npe_ucode - set load address for the NPE microcode
4633 tftpsrcport - If this is set, the value is used for TFTP's
4636 tftpdstport - If this is set, the value is used for TFTP's UDP
4637 destination port instead of the Well Know Port 69.
4639 tftpblocksize - Block size to use for TFTP transfers; if not set,
4640 we use the TFTP server's default block size
4642 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4643 seconds, minimum value is 1000 = 1 second). Defines
4644 when a packet is considered to be lost so it has to
4645 be retransmitted. The default is 5000 = 5 seconds.
4646 Lowering this value may make downloads succeed
4647 faster in networks with high packet loss rates or
4648 with unreliable TFTP servers.
4650 vlan - When set to a value < 4095 the traffic over
4651 Ethernet is encapsulated/received over 802.1q
4654 The following image location variables contain the location of images
4655 used in booting. The "Image" column gives the role of the image and is
4656 not an environment variable name. The other columns are environment
4657 variable names. "File Name" gives the name of the file on a TFTP
4658 server, "RAM Address" gives the location in RAM the image will be
4659 loaded to, and "Flash Location" gives the image's address in NOR
4660 flash or offset in NAND flash.
4662 *Note* - these variables don't have to be defined for all boards, some
4663 boards currenlty use other variables for these purposes, and some
4664 boards use these variables for other purposes.
4666 Image File Name RAM Address Flash Location
4667 ----- --------- ----------- --------------
4668 u-boot u-boot u-boot_addr_r u-boot_addr
4669 Linux kernel bootfile kernel_addr_r kernel_addr
4670 device tree blob fdtfile fdt_addr_r fdt_addr
4671 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4673 The following environment variables may be used and automatically
4674 updated by the network boot commands ("bootp" and "rarpboot"),
4675 depending the information provided by your boot server:
4677 bootfile - see above
4678 dnsip - IP address of your Domain Name Server
4679 dnsip2 - IP address of your secondary Domain Name Server
4680 gatewayip - IP address of the Gateway (Router) to use
4681 hostname - Target hostname
4683 netmask - Subnet Mask
4684 rootpath - Pathname of the root filesystem on the NFS server
4685 serverip - see above
4688 There are two special Environment Variables:
4690 serial# - contains hardware identification information such
4691 as type string and/or serial number
4692 ethaddr - Ethernet address
4694 These variables can be set only once (usually during manufacturing of
4695 the board). U-Boot refuses to delete or overwrite these variables
4696 once they have been set once.
4699 Further special Environment Variables:
4701 ver - Contains the U-Boot version string as printed
4702 with the "version" command. This variable is
4703 readonly (see CONFIG_VERSION_VARIABLE).
4706 Please note that changes to some configuration parameters may take
4707 only effect after the next boot (yes, that's just like Windoze :-).
4710 Callback functions for environment variables:
4711 ---------------------------------------------
4713 For some environment variables, the behavior of u-boot needs to change
4714 when their values are changed. This functionailty allows functions to
4715 be associated with arbitrary variables. On creation, overwrite, or
4716 deletion, the callback will provide the opportunity for some side
4717 effect to happen or for the change to be rejected.
4719 The callbacks are named and associated with a function using the
4720 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4722 These callbacks are associated with variables in one of two ways. The
4723 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4724 in the board configuration to a string that defines a list of
4725 associations. The list must be in the following format:
4727 entry = variable_name[:callback_name]
4730 If the callback name is not specified, then the callback is deleted.
4731 Spaces are also allowed anywhere in the list.
4733 Callbacks can also be associated by defining the ".callbacks" variable
4734 with the same list format above. Any association in ".callbacks" will
4735 override any association in the static list. You can define
4736 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4737 ".callbacks" envirnoment variable in the default or embedded environment.
4740 Command Line Parsing:
4741 =====================
4743 There are two different command line parsers available with U-Boot:
4744 the old "simple" one, and the much more powerful "hush" shell:
4746 Old, simple command line parser:
4747 --------------------------------
4749 - supports environment variables (through setenv / saveenv commands)
4750 - several commands on one line, separated by ';'
4751 - variable substitution using "... ${name} ..." syntax
4752 - special characters ('$', ';') can be escaped by prefixing with '\',
4754 setenv bootcmd bootm \${address}
4755 - You can also escape text by enclosing in single apostrophes, for example:
4756 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4761 - similar to Bourne shell, with control structures like
4762 if...then...else...fi, for...do...done; while...do...done,
4763 until...do...done, ...
4764 - supports environment ("global") variables (through setenv / saveenv
4765 commands) and local shell variables (through standard shell syntax
4766 "name=value"); only environment variables can be used with "run"
4772 (1) If a command line (or an environment variable executed by a "run"
4773 command) contains several commands separated by semicolon, and
4774 one of these commands fails, then the remaining commands will be
4777 (2) If you execute several variables with one call to run (i. e.
4778 calling run with a list of variables as arguments), any failing
4779 command will cause "run" to terminate, i. e. the remaining
4780 variables are not executed.
4782 Note for Redundant Ethernet Interfaces:
4783 =======================================
4785 Some boards come with redundant Ethernet interfaces; U-Boot supports
4786 such configurations and is capable of automatic selection of a
4787 "working" interface when needed. MAC assignment works as follows:
4789 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4790 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4791 "eth1addr" (=>eth1), "eth2addr", ...
4793 If the network interface stores some valid MAC address (for instance
4794 in SROM), this is used as default address if there is NO correspon-
4795 ding setting in the environment; if the corresponding environment
4796 variable is set, this overrides the settings in the card; that means:
4798 o If the SROM has a valid MAC address, and there is no address in the
4799 environment, the SROM's address is used.
4801 o If there is no valid address in the SROM, and a definition in the
4802 environment exists, then the value from the environment variable is
4805 o If both the SROM and the environment contain a MAC address, and
4806 both addresses are the same, this MAC address is used.
4808 o If both the SROM and the environment contain a MAC address, and the
4809 addresses differ, the value from the environment is used and a
4812 o If neither SROM nor the environment contain a MAC address, an error
4815 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4816 will be programmed into hardware as part of the initialization process. This
4817 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4818 The naming convention is as follows:
4819 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4824 U-Boot is capable of booting (and performing other auxiliary operations on)
4825 images in two formats:
4827 New uImage format (FIT)
4828 -----------------------
4830 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4831 to Flattened Device Tree). It allows the use of images with multiple
4832 components (several kernels, ramdisks, etc.), with contents protected by
4833 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4839 Old image format is based on binary files which can be basically anything,
4840 preceded by a special header; see the definitions in include/image.h for
4841 details; basically, the header defines the following image properties:
4843 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4844 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4845 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4846 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4848 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4849 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4850 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4851 * Compression Type (uncompressed, gzip, bzip2)
4857 The header is marked by a special Magic Number, and both the header
4858 and the data portions of the image are secured against corruption by
4865 Although U-Boot should support any OS or standalone application
4866 easily, the main focus has always been on Linux during the design of
4869 U-Boot includes many features that so far have been part of some
4870 special "boot loader" code within the Linux kernel. Also, any
4871 "initrd" images to be used are no longer part of one big Linux image;
4872 instead, kernel and "initrd" are separate images. This implementation
4873 serves several purposes:
4875 - the same features can be used for other OS or standalone
4876 applications (for instance: using compressed images to reduce the
4877 Flash memory footprint)
4879 - it becomes much easier to port new Linux kernel versions because
4880 lots of low-level, hardware dependent stuff are done by U-Boot
4882 - the same Linux kernel image can now be used with different "initrd"
4883 images; of course this also means that different kernel images can
4884 be run with the same "initrd". This makes testing easier (you don't
4885 have to build a new "zImage.initrd" Linux image when you just
4886 change a file in your "initrd"). Also, a field-upgrade of the
4887 software is easier now.
4893 Porting Linux to U-Boot based systems:
4894 ---------------------------------------
4896 U-Boot cannot save you from doing all the necessary modifications to
4897 configure the Linux device drivers for use with your target hardware
4898 (no, we don't intend to provide a full virtual machine interface to
4901 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4903 Just make sure your machine specific header file (for instance
4904 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4905 Information structure as we define in include/asm-<arch>/u-boot.h,
4906 and make sure that your definition of IMAP_ADDR uses the same value
4907 as your U-Boot configuration in CONFIG_SYS_IMMR.
4910 Configuring the Linux kernel:
4911 -----------------------------
4913 No specific requirements for U-Boot. Make sure you have some root
4914 device (initial ramdisk, NFS) for your target system.
4917 Building a Linux Image:
4918 -----------------------
4920 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4921 not used. If you use recent kernel source, a new build target
4922 "uImage" will exist which automatically builds an image usable by
4923 U-Boot. Most older kernels also have support for a "pImage" target,
4924 which was introduced for our predecessor project PPCBoot and uses a
4925 100% compatible format.
4934 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4935 encapsulate a compressed Linux kernel image with header information,
4936 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4938 * build a standard "vmlinux" kernel image (in ELF binary format):
4940 * convert the kernel into a raw binary image:
4942 ${CROSS_COMPILE}-objcopy -O binary \
4943 -R .note -R .comment \
4944 -S vmlinux linux.bin
4946 * compress the binary image:
4950 * package compressed binary image for U-Boot:
4952 mkimage -A ppc -O linux -T kernel -C gzip \
4953 -a 0 -e 0 -n "Linux Kernel Image" \
4954 -d linux.bin.gz uImage
4957 The "mkimage" tool can also be used to create ramdisk images for use
4958 with U-Boot, either separated from the Linux kernel image, or
4959 combined into one file. "mkimage" encapsulates the images with a 64
4960 byte header containing information about target architecture,
4961 operating system, image type, compression method, entry points, time
4962 stamp, CRC32 checksums, etc.
4964 "mkimage" can be called in two ways: to verify existing images and
4965 print the header information, or to build new images.
4967 In the first form (with "-l" option) mkimage lists the information
4968 contained in the header of an existing U-Boot image; this includes
4969 checksum verification:
4971 tools/mkimage -l image
4972 -l ==> list image header information
4974 The second form (with "-d" option) is used to build a U-Boot image
4975 from a "data file" which is used as image payload:
4977 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4978 -n name -d data_file image
4979 -A ==> set architecture to 'arch'
4980 -O ==> set operating system to 'os'
4981 -T ==> set image type to 'type'
4982 -C ==> set compression type 'comp'
4983 -a ==> set load address to 'addr' (hex)
4984 -e ==> set entry point to 'ep' (hex)
4985 -n ==> set image name to 'name'
4986 -d ==> use image data from 'datafile'
4988 Right now, all Linux kernels for PowerPC systems use the same load
4989 address (0x00000000), but the entry point address depends on the
4992 - 2.2.x kernels have the entry point at 0x0000000C,
4993 - 2.3.x and later kernels have the entry point at 0x00000000.
4995 So a typical call to build a U-Boot image would read:
4997 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4998 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4999 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5000 > examples/uImage.TQM850L
5001 Image Name: 2.4.4 kernel for TQM850L
5002 Created: Wed Jul 19 02:34:59 2000
5003 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5004 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5005 Load Address: 0x00000000
5006 Entry Point: 0x00000000
5008 To verify the contents of the image (or check for corruption):
5010 -> tools/mkimage -l examples/uImage.TQM850L
5011 Image Name: 2.4.4 kernel for TQM850L
5012 Created: Wed Jul 19 02:34:59 2000
5013 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5014 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5015 Load Address: 0x00000000
5016 Entry Point: 0x00000000
5018 NOTE: for embedded systems where boot time is critical you can trade
5019 speed for memory and install an UNCOMPRESSED image instead: this
5020 needs more space in Flash, but boots much faster since it does not
5021 need to be uncompressed:
5023 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5024 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5025 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5026 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5027 > examples/uImage.TQM850L-uncompressed
5028 Image Name: 2.4.4 kernel for TQM850L
5029 Created: Wed Jul 19 02:34:59 2000
5030 Image Type: PowerPC Linux Kernel Image (uncompressed)
5031 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5032 Load Address: 0x00000000
5033 Entry Point: 0x00000000
5036 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5037 when your kernel is intended to use an initial ramdisk:
5039 -> tools/mkimage -n 'Simple Ramdisk Image' \
5040 > -A ppc -O linux -T ramdisk -C gzip \
5041 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5042 Image Name: Simple Ramdisk Image
5043 Created: Wed Jan 12 14:01:50 2000
5044 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5045 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5046 Load Address: 0x00000000
5047 Entry Point: 0x00000000
5050 Installing a Linux Image:
5051 -------------------------
5053 To downloading a U-Boot image over the serial (console) interface,
5054 you must convert the image to S-Record format:
5056 objcopy -I binary -O srec examples/image examples/image.srec
5058 The 'objcopy' does not understand the information in the U-Boot
5059 image header, so the resulting S-Record file will be relative to
5060 address 0x00000000. To load it to a given address, you need to
5061 specify the target address as 'offset' parameter with the 'loads'
5064 Example: install the image to address 0x40100000 (which on the
5065 TQM8xxL is in the first Flash bank):
5067 => erase 40100000 401FFFFF
5073 ## Ready for S-Record download ...
5074 ~>examples/image.srec
5075 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5077 15989 15990 15991 15992
5078 [file transfer complete]
5080 ## Start Addr = 0x00000000
5083 You can check the success of the download using the 'iminfo' command;
5084 this includes a checksum verification so you can be sure no data
5085 corruption happened:
5089 ## Checking Image at 40100000 ...
5090 Image Name: 2.2.13 for initrd on TQM850L
5091 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5092 Data Size: 335725 Bytes = 327 kB = 0 MB
5093 Load Address: 00000000
5094 Entry Point: 0000000c
5095 Verifying Checksum ... OK
5101 The "bootm" command is used to boot an application that is stored in
5102 memory (RAM or Flash). In case of a Linux kernel image, the contents
5103 of the "bootargs" environment variable is passed to the kernel as
5104 parameters. You can check and modify this variable using the
5105 "printenv" and "setenv" commands:
5108 => printenv bootargs
5109 bootargs=root=/dev/ram
5111 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5113 => printenv bootargs
5114 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5117 ## Booting Linux kernel at 40020000 ...
5118 Image Name: 2.2.13 for NFS on TQM850L
5119 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5120 Data Size: 381681 Bytes = 372 kB = 0 MB
5121 Load Address: 00000000
5122 Entry Point: 0000000c
5123 Verifying Checksum ... OK
5124 Uncompressing Kernel Image ... OK
5125 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
5126 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5127 time_init: decrementer frequency = 187500000/60
5128 Calibrating delay loop... 49.77 BogoMIPS
5129 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5132 If you want to boot a Linux kernel with initial RAM disk, you pass
5133 the memory addresses of both the kernel and the initrd image (PPBCOOT
5134 format!) to the "bootm" command:
5136 => imi 40100000 40200000
5138 ## Checking Image at 40100000 ...
5139 Image Name: 2.2.13 for initrd on TQM850L
5140 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5141 Data Size: 335725 Bytes = 327 kB = 0 MB
5142 Load Address: 00000000
5143 Entry Point: 0000000c
5144 Verifying Checksum ... OK
5146 ## Checking Image at 40200000 ...
5147 Image Name: Simple Ramdisk Image
5148 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5149 Data Size: 566530 Bytes = 553 kB = 0 MB
5150 Load Address: 00000000
5151 Entry Point: 00000000
5152 Verifying Checksum ... OK
5154 => bootm 40100000 40200000
5155 ## Booting Linux kernel at 40100000 ...
5156 Image Name: 2.2.13 for initrd on TQM850L
5157 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5158 Data Size: 335725 Bytes = 327 kB = 0 MB
5159 Load Address: 00000000
5160 Entry Point: 0000000c
5161 Verifying Checksum ... OK
5162 Uncompressing Kernel Image ... OK
5163 ## Loading RAMDisk Image at 40200000 ...
5164 Image Name: Simple Ramdisk Image
5165 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5166 Data Size: 566530 Bytes = 553 kB = 0 MB
5167 Load Address: 00000000
5168 Entry Point: 00000000
5169 Verifying Checksum ... OK
5170 Loading Ramdisk ... OK
5171 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
5172 Boot arguments: root=/dev/ram
5173 time_init: decrementer frequency = 187500000/60
5174 Calibrating delay loop... 49.77 BogoMIPS
5176 RAMDISK: Compressed image found at block 0
5177 VFS: Mounted root (ext2 filesystem).
5181 Boot Linux and pass a flat device tree:
5184 First, U-Boot must be compiled with the appropriate defines. See the section
5185 titled "Linux Kernel Interface" above for a more in depth explanation. The
5186 following is an example of how to start a kernel and pass an updated
5192 oft=oftrees/mpc8540ads.dtb
5193 => tftp $oftaddr $oft
5194 Speed: 1000, full duplex
5196 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5197 Filename 'oftrees/mpc8540ads.dtb'.
5198 Load address: 0x300000
5201 Bytes transferred = 4106 (100a hex)
5202 => tftp $loadaddr $bootfile
5203 Speed: 1000, full duplex
5205 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5207 Load address: 0x200000
5208 Loading:############
5210 Bytes transferred = 1029407 (fb51f hex)
5215 => bootm $loadaddr - $oftaddr
5216 ## Booting image at 00200000 ...
5217 Image Name: Linux-2.6.17-dirty
5218 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5219 Data Size: 1029343 Bytes = 1005.2 kB
5220 Load Address: 00000000
5221 Entry Point: 00000000
5222 Verifying Checksum ... OK
5223 Uncompressing Kernel Image ... OK
5224 Booting using flat device tree at 0x300000
5225 Using MPC85xx ADS machine description
5226 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5230 More About U-Boot Image Types:
5231 ------------------------------
5233 U-Boot supports the following image types:
5235 "Standalone Programs" are directly runnable in the environment
5236 provided by U-Boot; it is expected that (if they behave
5237 well) you can continue to work in U-Boot after return from
5238 the Standalone Program.
5239 "OS Kernel Images" are usually images of some Embedded OS which
5240 will take over control completely. Usually these programs
5241 will install their own set of exception handlers, device
5242 drivers, set up the MMU, etc. - this means, that you cannot
5243 expect to re-enter U-Boot except by resetting the CPU.
5244 "RAMDisk Images" are more or less just data blocks, and their
5245 parameters (address, size) are passed to an OS kernel that is
5247 "Multi-File Images" contain several images, typically an OS
5248 (Linux) kernel image and one or more data images like
5249 RAMDisks. This construct is useful for instance when you want
5250 to boot over the network using BOOTP etc., where the boot
5251 server provides just a single image file, but you want to get
5252 for instance an OS kernel and a RAMDisk image.
5254 "Multi-File Images" start with a list of image sizes, each
5255 image size (in bytes) specified by an "uint32_t" in network
5256 byte order. This list is terminated by an "(uint32_t)0".
5257 Immediately after the terminating 0 follow the images, one by
5258 one, all aligned on "uint32_t" boundaries (size rounded up to
5259 a multiple of 4 bytes).
5261 "Firmware Images" are binary images containing firmware (like
5262 U-Boot or FPGA images) which usually will be programmed to
5265 "Script files" are command sequences that will be executed by
5266 U-Boot's command interpreter; this feature is especially
5267 useful when you configure U-Boot to use a real shell (hush)
5268 as command interpreter.
5270 Booting the Linux zImage:
5271 -------------------------
5273 On some platforms, it's possible to boot Linux zImage. This is done
5274 using the "bootz" command. The syntax of "bootz" command is the same
5275 as the syntax of "bootm" command.
5277 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5278 kernel with raw initrd images. The syntax is slightly different, the
5279 address of the initrd must be augmented by it's size, in the following
5280 format: "<initrd addres>:<initrd size>".
5286 One of the features of U-Boot is that you can dynamically load and
5287 run "standalone" applications, which can use some resources of
5288 U-Boot like console I/O functions or interrupt services.
5290 Two simple examples are included with the sources:
5295 'examples/hello_world.c' contains a small "Hello World" Demo
5296 application; it is automatically compiled when you build U-Boot.
5297 It's configured to run at address 0x00040004, so you can play with it
5301 ## Ready for S-Record download ...
5302 ~>examples/hello_world.srec
5303 1 2 3 4 5 6 7 8 9 10 11 ...
5304 [file transfer complete]
5306 ## Start Addr = 0x00040004
5308 => go 40004 Hello World! This is a test.
5309 ## Starting application at 0x00040004 ...
5320 Hit any key to exit ...
5322 ## Application terminated, rc = 0x0
5324 Another example, which demonstrates how to register a CPM interrupt
5325 handler with the U-Boot code, can be found in 'examples/timer.c'.
5326 Here, a CPM timer is set up to generate an interrupt every second.
5327 The interrupt service routine is trivial, just printing a '.'
5328 character, but this is just a demo program. The application can be
5329 controlled by the following keys:
5331 ? - print current values og the CPM Timer registers
5332 b - enable interrupts and start timer
5333 e - stop timer and disable interrupts
5334 q - quit application
5337 ## Ready for S-Record download ...
5338 ~>examples/timer.srec
5339 1 2 3 4 5 6 7 8 9 10 11 ...
5340 [file transfer complete]
5342 ## Start Addr = 0x00040004
5345 ## Starting application at 0x00040004 ...
5348 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5351 [q, b, e, ?] Set interval 1000000 us
5354 [q, b, e, ?] ........
5355 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5358 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5361 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5364 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5366 [q, b, e, ?] ...Stopping timer
5368 [q, b, e, ?] ## Application terminated, rc = 0x0
5374 Over time, many people have reported problems when trying to use the
5375 "minicom" terminal emulation program for serial download. I (wd)
5376 consider minicom to be broken, and recommend not to use it. Under
5377 Unix, I recommend to use C-Kermit for general purpose use (and
5378 especially for kermit binary protocol download ("loadb" command), and
5379 use "cu" for S-Record download ("loads" command). See
5380 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5381 for help with kermit.
5384 Nevertheless, if you absolutely want to use it try adding this
5385 configuration to your "File transfer protocols" section:
5387 Name Program Name U/D FullScr IO-Red. Multi
5388 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5389 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5395 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5396 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5398 Building requires a cross environment; it is known to work on
5399 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5400 need gmake since the Makefiles are not compatible with BSD make).
5401 Note that the cross-powerpc package does not install include files;
5402 attempting to build U-Boot will fail because <machine/ansi.h> is
5403 missing. This file has to be installed and patched manually:
5405 # cd /usr/pkg/cross/powerpc-netbsd/include
5407 # ln -s powerpc machine
5408 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5409 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5411 Native builds *don't* work due to incompatibilities between native
5412 and U-Boot include files.
5414 Booting assumes that (the first part of) the image booted is a
5415 stage-2 loader which in turn loads and then invokes the kernel
5416 proper. Loader sources will eventually appear in the NetBSD source
5417 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5418 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5421 Implementation Internals:
5422 =========================
5424 The following is not intended to be a complete description of every
5425 implementation detail. However, it should help to understand the
5426 inner workings of U-Boot and make it easier to port it to custom
5430 Initial Stack, Global Data:
5431 ---------------------------
5433 The implementation of U-Boot is complicated by the fact that U-Boot
5434 starts running out of ROM (flash memory), usually without access to
5435 system RAM (because the memory controller is not initialized yet).
5436 This means that we don't have writable Data or BSS segments, and BSS
5437 is not initialized as zero. To be able to get a C environment working
5438 at all, we have to allocate at least a minimal stack. Implementation
5439 options for this are defined and restricted by the CPU used: Some CPU
5440 models provide on-chip memory (like the IMMR area on MPC8xx and
5441 MPC826x processors), on others (parts of) the data cache can be
5442 locked as (mis-) used as memory, etc.
5444 Chris Hallinan posted a good summary of these issues to the
5445 U-Boot mailing list:
5447 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5448 From: "Chris Hallinan" <clh@net1plus.com>
5449 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5452 Correct me if I'm wrong, folks, but the way I understand it
5453 is this: Using DCACHE as initial RAM for Stack, etc, does not
5454 require any physical RAM backing up the cache. The cleverness
5455 is that the cache is being used as a temporary supply of
5456 necessary storage before the SDRAM controller is setup. It's
5457 beyond the scope of this list to explain the details, but you
5458 can see how this works by studying the cache architecture and
5459 operation in the architecture and processor-specific manuals.
5461 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5462 is another option for the system designer to use as an
5463 initial stack/RAM area prior to SDRAM being available. Either
5464 option should work for you. Using CS 4 should be fine if your
5465 board designers haven't used it for something that would
5466 cause you grief during the initial boot! It is frequently not
5469 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5470 with your processor/board/system design. The default value
5471 you will find in any recent u-boot distribution in
5472 walnut.h should work for you. I'd set it to a value larger
5473 than your SDRAM module. If you have a 64MB SDRAM module, set
5474 it above 400_0000. Just make sure your board has no resources
5475 that are supposed to respond to that address! That code in
5476 start.S has been around a while and should work as is when
5477 you get the config right.
5482 It is essential to remember this, since it has some impact on the C
5483 code for the initialization procedures:
5485 * Initialized global data (data segment) is read-only. Do not attempt
5488 * Do not use any uninitialized global data (or implicitely initialized
5489 as zero data - BSS segment) at all - this is undefined, initiali-
5490 zation is performed later (when relocating to RAM).
5492 * Stack space is very limited. Avoid big data buffers or things like
5495 Having only the stack as writable memory limits means we cannot use
5496 normal global data to share information beween the code. But it
5497 turned out that the implementation of U-Boot can be greatly
5498 simplified by making a global data structure (gd_t) available to all
5499 functions. We could pass a pointer to this data as argument to _all_
5500 functions, but this would bloat the code. Instead we use a feature of
5501 the GCC compiler (Global Register Variables) to share the data: we
5502 place a pointer (gd) to the global data into a register which we
5503 reserve for this purpose.
5505 When choosing a register for such a purpose we are restricted by the
5506 relevant (E)ABI specifications for the current architecture, and by
5507 GCC's implementation.
5509 For PowerPC, the following registers have specific use:
5511 R2: reserved for system use
5512 R3-R4: parameter passing and return values
5513 R5-R10: parameter passing
5514 R13: small data area pointer
5518 (U-Boot also uses R12 as internal GOT pointer. r12
5519 is a volatile register so r12 needs to be reset when
5520 going back and forth between asm and C)
5522 ==> U-Boot will use R2 to hold a pointer to the global data
5524 Note: on PPC, we could use a static initializer (since the
5525 address of the global data structure is known at compile time),
5526 but it turned out that reserving a register results in somewhat
5527 smaller code - although the code savings are not that big (on
5528 average for all boards 752 bytes for the whole U-Boot image,
5529 624 text + 127 data).
5531 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5532 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5534 ==> U-Boot will use P3 to hold a pointer to the global data
5536 On ARM, the following registers are used:
5538 R0: function argument word/integer result
5539 R1-R3: function argument word
5541 R10: stack limit (used only if stack checking if enabled)
5542 R11: argument (frame) pointer
5543 R12: temporary workspace
5546 R15: program counter
5548 ==> U-Boot will use R8 to hold a pointer to the global data
5550 On Nios II, the ABI is documented here:
5551 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5553 ==> U-Boot will use gp to hold a pointer to the global data
5555 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5556 to access small data sections, so gp is free.
5558 On NDS32, the following registers are used:
5560 R0-R1: argument/return
5562 R15: temporary register for assembler
5563 R16: trampoline register
5564 R28: frame pointer (FP)
5565 R29: global pointer (GP)
5566 R30: link register (LP)
5567 R31: stack pointer (SP)
5568 PC: program counter (PC)
5570 ==> U-Boot will use R10 to hold a pointer to the global data
5572 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5573 or current versions of GCC may "optimize" the code too much.
5578 U-Boot runs in system state and uses physical addresses, i.e. the
5579 MMU is not used either for address mapping nor for memory protection.
5581 The available memory is mapped to fixed addresses using the memory
5582 controller. In this process, a contiguous block is formed for each
5583 memory type (Flash, SDRAM, SRAM), even when it consists of several
5584 physical memory banks.
5586 U-Boot is installed in the first 128 kB of the first Flash bank (on
5587 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5588 booting and sizing and initializing DRAM, the code relocates itself
5589 to the upper end of DRAM. Immediately below the U-Boot code some
5590 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5591 configuration setting]. Below that, a structure with global Board
5592 Info data is placed, followed by the stack (growing downward).
5594 Additionally, some exception handler code is copied to the low 8 kB
5595 of DRAM (0x00000000 ... 0x00001FFF).
5597 So a typical memory configuration with 16 MB of DRAM could look like
5600 0x0000 0000 Exception Vector code
5603 0x0000 2000 Free for Application Use
5609 0x00FB FF20 Monitor Stack (Growing downward)
5610 0x00FB FFAC Board Info Data and permanent copy of global data
5611 0x00FC 0000 Malloc Arena
5614 0x00FE 0000 RAM Copy of Monitor Code
5615 ... eventually: LCD or video framebuffer
5616 ... eventually: pRAM (Protected RAM - unchanged by reset)
5617 0x00FF FFFF [End of RAM]
5620 System Initialization:
5621 ----------------------
5623 In the reset configuration, U-Boot starts at the reset entry point
5624 (on most PowerPC systems at address 0x00000100). Because of the reset
5625 configuration for CS0# this is a mirror of the onboard Flash memory.
5626 To be able to re-map memory U-Boot then jumps to its link address.
5627 To be able to implement the initialization code in C, a (small!)
5628 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5629 which provide such a feature like MPC8xx or MPC8260), or in a locked
5630 part of the data cache. After that, U-Boot initializes the CPU core,
5631 the caches and the SIU.
5633 Next, all (potentially) available memory banks are mapped using a
5634 preliminary mapping. For example, we put them on 512 MB boundaries
5635 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5636 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5637 programmed for SDRAM access. Using the temporary configuration, a
5638 simple memory test is run that determines the size of the SDRAM
5641 When there is more than one SDRAM bank, and the banks are of
5642 different size, the largest is mapped first. For equal size, the first
5643 bank (CS2#) is mapped first. The first mapping is always for address
5644 0x00000000, with any additional banks following immediately to create
5645 contiguous memory starting from 0.
5647 Then, the monitor installs itself at the upper end of the SDRAM area
5648 and allocates memory for use by malloc() and for the global Board
5649 Info data; also, the exception vector code is copied to the low RAM
5650 pages, and the final stack is set up.
5652 Only after this relocation will you have a "normal" C environment;
5653 until that you are restricted in several ways, mostly because you are
5654 running from ROM, and because the code will have to be relocated to a
5658 U-Boot Porting Guide:
5659 ----------------------
5661 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5665 int main(int argc, char *argv[])
5667 sighandler_t no_more_time;
5669 signal(SIGALRM, no_more_time);
5670 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5672 if (available_money > available_manpower) {
5673 Pay consultant to port U-Boot;
5677 Download latest U-Boot source;
5679 Subscribe to u-boot mailing list;
5682 email("Hi, I am new to U-Boot, how do I get started?");
5685 Read the README file in the top level directory;
5686 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5687 Read applicable doc/*.README;
5688 Read the source, Luke;
5689 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5692 if (available_money > toLocalCurrency ($2500))
5695 Add a lot of aggravation and time;
5697 if (a similar board exists) { /* hopefully... */
5698 cp -a board/<similar> board/<myboard>
5699 cp include/configs/<similar>.h include/configs/<myboard>.h
5701 Create your own board support subdirectory;
5702 Create your own board include/configs/<myboard>.h file;
5704 Edit new board/<myboard> files
5705 Edit new include/configs/<myboard>.h
5710 Add / modify source code;
5714 email("Hi, I am having problems...");
5716 Send patch file to the U-Boot email list;
5717 if (reasonable critiques)
5718 Incorporate improvements from email list code review;
5720 Defend code as written;
5726 void no_more_time (int sig)
5735 All contributions to U-Boot should conform to the Linux kernel
5736 coding style; see the file "Documentation/CodingStyle" and the script
5737 "scripts/Lindent" in your Linux kernel source directory.
5739 Source files originating from a different project (for example the
5740 MTD subsystem) are generally exempt from these guidelines and are not
5741 reformated to ease subsequent migration to newer versions of those
5744 Please note that U-Boot is implemented in C (and to some small parts in
5745 Assembler); no C++ is used, so please do not use C++ style comments (//)
5748 Please also stick to the following formatting rules:
5749 - remove any trailing white space
5750 - use TAB characters for indentation and vertical alignment, not spaces
5751 - make sure NOT to use DOS '\r\n' line feeds
5752 - do not add more than 2 consecutive empty lines to source files
5753 - do not add trailing empty lines to source files
5755 Submissions which do not conform to the standards may be returned
5756 with a request to reformat the changes.
5762 Since the number of patches for U-Boot is growing, we need to
5763 establish some rules. Submissions which do not conform to these rules
5764 may be rejected, even when they contain important and valuable stuff.
5766 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5768 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5769 see http://lists.denx.de/mailman/listinfo/u-boot
5771 When you send a patch, please include the following information with
5774 * For bug fixes: a description of the bug and how your patch fixes
5775 this bug. Please try to include a way of demonstrating that the
5776 patch actually fixes something.
5778 * For new features: a description of the feature and your
5781 * A CHANGELOG entry as plaintext (separate from the patch)
5783 * For major contributions, your entry to the CREDITS file
5785 * When you add support for a new board, don't forget to add this
5786 board to the MAINTAINERS file, too.
5788 * If your patch adds new configuration options, don't forget to
5789 document these in the README file.
5791 * The patch itself. If you are using git (which is *strongly*
5792 recommended) you can easily generate the patch using the
5793 "git format-patch". If you then use "git send-email" to send it to
5794 the U-Boot mailing list, you will avoid most of the common problems
5795 with some other mail clients.
5797 If you cannot use git, use "diff -purN OLD NEW". If your version of
5798 diff does not support these options, then get the latest version of
5801 The current directory when running this command shall be the parent
5802 directory of the U-Boot source tree (i. e. please make sure that
5803 your patch includes sufficient directory information for the
5806 We prefer patches as plain text. MIME attachments are discouraged,
5807 and compressed attachments must not be used.
5809 * If one logical set of modifications affects or creates several
5810 files, all these changes shall be submitted in a SINGLE patch file.
5812 * Changesets that contain different, unrelated modifications shall be
5813 submitted as SEPARATE patches, one patch per changeset.
5818 * Before sending the patch, run the MAKEALL script on your patched
5819 source tree and make sure that no errors or warnings are reported
5820 for any of the boards.
5822 * Keep your modifications to the necessary minimum: A patch
5823 containing several unrelated changes or arbitrary reformats will be
5824 returned with a request to re-formatting / split it.
5826 * If you modify existing code, make sure that your new code does not
5827 add to the memory footprint of the code ;-) Small is beautiful!
5828 When adding new features, these should compile conditionally only
5829 (using #ifdef), and the resulting code with the new feature
5830 disabled must not need more memory than the old code without your
5833 * Remember that there is a size limit of 100 kB per message on the
5834 u-boot mailing list. Bigger patches will be moderated. If they are
5835 reasonable and not too big, they will be acknowledged. But patches
5836 bigger than the size limit should be avoided.
projects / oweals / u-boot.git / blob