2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
57 Note: There is no CHANGELOG file in the actual U-Boot source tree;
58 it can be created dynamically from the Git log using:
66 In case you have questions about, problems with or contributions for
67 U-Boot you should send a message to the U-Boot mailing list at
68 <u-boot@lists.denx.de>. There is also an archive of previous traffic
69 on the mailing list - please search the archive before asking FAQ's.
70 Please see http://lists.denx.de/pipermail/u-boot and
71 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
74 Where to get source code:
75 =========================
77 The U-Boot source code is maintained in the git repository at
78 git://www.denx.de/git/u-boot.git ; you can browse it online at
79 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
81 The "snapshot" links on this page allow you to download tarballs of
82 any version you might be interested in. Official releases are also
83 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
86 Pre-built (and tested) images are available from
87 ftp://ftp.denx.de/pub/u-boot/images/
93 - start from 8xxrom sources
94 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
96 - make it easier to add custom boards
97 - make it possible to add other [PowerPC] CPUs
98 - extend functions, especially:
99 * Provide extended interface to Linux boot loader
102 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
103 - create ARMBoot project (http://sourceforge.net/projects/armboot)
104 - add other CPU families (starting with ARM)
105 - create U-Boot project (http://sourceforge.net/projects/u-boot)
106 - current project page: see http://www.denx.de/wiki/U-Boot
112 The "official" name of this project is "Das U-Boot". The spelling
113 "U-Boot" shall be used in all written text (documentation, comments
114 in source files etc.). Example:
116 This is the README file for the U-Boot project.
118 File names etc. shall be based on the string "u-boot". Examples:
120 include/asm-ppc/u-boot.h
122 #include <asm/u-boot.h>
124 Variable names, preprocessor constants etc. shall be either based on
125 the string "u_boot" or on "U_BOOT". Example:
127 U_BOOT_VERSION u_boot_logo
128 IH_OS_U_BOOT u_boot_hush_start
134 Starting with the release in October 2008, the names of the releases
135 were changed from numerical release numbers without deeper meaning
136 into a time stamp based numbering. Regular releases are identified by
137 names consisting of the calendar year and month of the release date.
138 Additional fields (if present) indicate release candidates or bug fix
139 releases in "stable" maintenance trees.
142 U-Boot v2009.11 - Release November 2009
143 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
144 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
150 /arch Architecture specific files
151 /arm Files generic to ARM architecture
152 /cpu CPU specific files
153 /arm720t Files specific to ARM 720 CPUs
154 /arm920t Files specific to ARM 920 CPUs
155 /at91 Files specific to Atmel AT91RM9200 CPU
156 /imx Files specific to Freescale MC9328 i.MX CPUs
157 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
158 /arm925t Files specific to ARM 925 CPUs
159 /arm926ejs Files specific to ARM 926 CPUs
160 /arm1136 Files specific to ARM 1136 CPUs
161 /ixp Files specific to Intel XScale IXP CPUs
162 /pxa Files specific to Intel XScale PXA CPUs
163 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
164 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
165 /lib Architecture specific library files
166 /avr32 Files generic to AVR32 architecture
167 /cpu CPU specific files
168 /lib Architecture specific library files
169 /blackfin Files generic to Analog Devices Blackfin architecture
170 /cpu CPU specific files
171 /lib Architecture specific library files
172 /x86 Files generic to x86 architecture
173 /cpu CPU specific files
174 /lib Architecture specific library files
175 /m68k Files generic to m68k architecture
176 /cpu CPU specific files
177 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
178 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
179 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
180 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
181 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
182 /lib Architecture specific library files
183 /microblaze Files generic to microblaze architecture
184 /cpu CPU specific files
185 /lib Architecture specific library files
186 /mips Files generic to MIPS architecture
187 /cpu CPU specific files
188 /mips32 Files specific to MIPS32 CPUs
189 /xburst Files specific to Ingenic XBurst CPUs
190 /lib Architecture specific library files
191 /nds32 Files generic to NDS32 architecture
192 /cpu CPU specific files
193 /n1213 Files specific to Andes Technology N1213 CPUs
194 /lib Architecture specific library files
195 /nios2 Files generic to Altera NIOS2 architecture
196 /cpu CPU specific files
197 /lib Architecture specific library files
198 /powerpc Files generic to PowerPC architecture
199 /cpu CPU specific files
200 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
201 /mpc5xx Files specific to Freescale MPC5xx CPUs
202 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
203 /mpc8xx Files specific to Freescale MPC8xx CPUs
204 /mpc8220 Files specific to Freescale MPC8220 CPUs
205 /mpc824x Files specific to Freescale MPC824x CPUs
206 /mpc8260 Files specific to Freescale MPC8260 CPUs
207 /mpc85xx Files specific to Freescale MPC85xx CPUs
208 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
209 /lib Architecture specific library files
210 /sh Files generic to SH architecture
211 /cpu CPU specific files
212 /sh2 Files specific to sh2 CPUs
213 /sh3 Files specific to sh3 CPUs
214 /sh4 Files specific to sh4 CPUs
215 /lib Architecture specific library files
216 /sparc Files generic to SPARC architecture
217 /cpu CPU specific files
218 /leon2 Files specific to Gaisler LEON2 SPARC CPU
219 /leon3 Files specific to Gaisler LEON3 SPARC CPU
220 /lib Architecture specific library files
221 /api Machine/arch independent API for external apps
222 /board Board dependent files
223 /common Misc architecture independent functions
224 /disk Code for disk drive partition handling
225 /doc Documentation (don't expect too much)
226 /drivers Commonly used device drivers
227 /examples Example code for standalone applications, etc.
228 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
229 /include Header Files
230 /lib Files generic to all architectures
231 /libfdt Library files to support flattened device trees
232 /lzma Library files to support LZMA decompression
233 /lzo Library files to support LZO decompression
235 /post Power On Self Test
236 /rtc Real Time Clock drivers
237 /tools Tools to build S-Record or U-Boot images, etc.
239 Software Configuration:
240 =======================
242 Configuration is usually done using C preprocessor defines; the
243 rationale behind that is to avoid dead code whenever possible.
245 There are two classes of configuration variables:
247 * Configuration _OPTIONS_:
248 These are selectable by the user and have names beginning with
251 * Configuration _SETTINGS_:
252 These depend on the hardware etc. and should not be meddled with if
253 you don't know what you're doing; they have names beginning with
256 Later we will add a configuration tool - probably similar to or even
257 identical to what's used for the Linux kernel. Right now, we have to
258 do the configuration by hand, which means creating some symbolic
259 links and editing some configuration files. We use the TQM8xxL boards
263 Selection of Processor Architecture and Board Type:
264 ---------------------------------------------------
266 For all supported boards there are ready-to-use default
267 configurations available; just type "make <board_name>_config".
269 Example: For a TQM823L module type:
274 For the Cogent platform, you need to specify the CPU type as well;
275 e.g. "make cogent_mpc8xx_config". And also configure the cogent
276 directory according to the instructions in cogent/README.
279 Configuration Options:
280 ----------------------
282 Configuration depends on the combination of board and CPU type; all
283 such information is kept in a configuration file
284 "include/configs/<board_name>.h".
286 Example: For a TQM823L module, all configuration settings are in
287 "include/configs/TQM823L.h".
290 Many of the options are named exactly as the corresponding Linux
291 kernel configuration options. The intention is to make it easier to
292 build a config tool - later.
295 The following options need to be configured:
297 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
299 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
301 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
302 Define exactly one, e.g. CONFIG_ATSTK1002
304 - CPU Module Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
307 --- FIXME --- not tested yet:
308 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
309 CONFIG_CMA287_23, CONFIG_CMA287_50
311 - Motherboard Type: (if CONFIG_COGENT is defined)
312 Define exactly one of
313 CONFIG_CMA101, CONFIG_CMA102
315 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
316 Define one or more of
319 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
320 Define one or more of
321 CONFIG_LCD_HEARTBEAT - update a character position on
322 the LCD display every second with
325 - Board flavour: (if CONFIG_MPC8260ADS is defined)
328 CONFIG_SYS_8260ADS - original MPC8260ADS
329 CONFIG_SYS_8266ADS - MPC8266ADS
330 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
331 CONFIG_SYS_8272ADS - MPC8272ADS
333 - Marvell Family Member
334 CONFIG_SYS_MVFS - define it if you want to enable
335 multiple fs option at one time
336 for marvell soc family
338 - MPC824X Family Member (if CONFIG_MPC824X is defined)
339 Define exactly one of
340 CONFIG_MPC8240, CONFIG_MPC8245
342 - 8xx CPU Options: (if using an MPC8xx CPU)
343 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
344 get_gclk_freq() cannot work
345 e.g. if there is no 32KHz
346 reference PIT/RTC clock
347 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
350 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
351 CONFIG_SYS_8xx_CPUCLK_MIN
352 CONFIG_SYS_8xx_CPUCLK_MAX
353 CONFIG_8xx_CPUCLK_DEFAULT
354 See doc/README.MPC866
356 CONFIG_SYS_MEASURE_CPUCLK
358 Define this to measure the actual CPU clock instead
359 of relying on the correctness of the configured
360 values. Mostly useful for board bringup to make sure
361 the PLL is locked at the intended frequency. Note
362 that this requires a (stable) reference clock (32 kHz
363 RTC clock or CONFIG_SYS_8XX_XIN)
365 CONFIG_SYS_DELAYED_ICACHE
367 Define this option if you want to enable the
368 ICache only when Code runs from RAM.
373 Specifies that the core is a 64-bit PowerPC implementation (implements
374 the "64" category of the Power ISA). This is necessary for ePAPR
375 compliance, among other possible reasons.
377 CONFIG_SYS_FSL_TBCLK_DIV
379 Defines the core time base clock divider ratio compared to the
380 system clock. On most PQ3 devices this is 8, on newer QorIQ
381 devices it can be 16 or 32. The ratio varies from SoC to Soc.
383 CONFIG_SYS_FSL_PCIE_COMPAT
385 Defines the string to utilize when trying to match PCIe device
386 tree nodes for the given platform.
388 CONFIG_SYS_PPC_E500_DEBUG_TLB
390 Enables a temporary TLB entry to be used during boot to work
391 around limitations in e500v1 and e500v2 external debugger
392 support. This reduces the portions of the boot code where
393 breakpoints and single stepping do not work. The value of this
394 symbol should be set to the TLB1 entry to be used for this
397 CONFIG_SYS_FSL_ERRATUM_A004510
399 Enables a workaround for erratum A004510. If set,
400 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
401 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
403 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
404 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
406 Defines one or two SoC revisions (low 8 bits of SVR)
407 for which the A004510 workaround should be applied.
409 The rest of SVR is either not relevant to the decision
410 of whether the erratum is present (e.g. p2040 versus
411 p2041) or is implied by the build target, which controls
412 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
414 See Freescale App Note 4493 for more information about
417 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
419 This is the value to write into CCSR offset 0x18600
420 according to the A004510 workaround.
422 - Generic CPU options:
423 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
425 Defines the endianess of the CPU. Implementation of those
426 values is arch specific.
428 - Intel Monahans options:
429 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
431 Defines the Monahans run mode to oscillator
432 ratio. Valid values are 8, 16, 24, 31. The core
433 frequency is this value multiplied by 13 MHz.
435 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
437 Defines the Monahans turbo mode to oscillator
438 ratio. Valid values are 1 (default if undefined) and
439 2. The core frequency as calculated above is multiplied
443 CONFIG_SYS_INIT_SP_OFFSET
445 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
446 pointer. This is needed for the temporary stack before
449 CONFIG_SYS_MIPS_CACHE_MODE
451 Cache operation mode for the MIPS CPU.
452 See also arch/mips/include/asm/mipsregs.h.
454 CONF_CM_CACHABLE_NO_WA
457 CONF_CM_CACHABLE_NONCOHERENT
461 CONF_CM_CACHABLE_ACCELERATED
463 CONFIG_SYS_XWAY_EBU_BOOTCFG
465 Special option for Lantiq XWAY SoCs for booting from NOR flash.
466 See also arch/mips/cpu/mips32/start.S.
468 CONFIG_XWAY_SWAP_BYTES
470 Enable compilation of tools/xway-swap-bytes needed for Lantiq
471 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
472 be swapped if a flash programmer is used.
475 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
477 Select high exception vectors of the ARM core, e.g., do not
478 clear the V bit of the c1 register of CP15.
480 CONFIG_SYS_THUMB_BUILD
482 Use this flag to build U-Boot using the Thumb instruction
483 set for ARM architectures. Thumb instruction set provides
484 better code density. For ARM architectures that support
485 Thumb2 this flag will result in Thumb2 code generated by
488 CONFIG_ARM_ERRATA_716044
489 CONFIG_ARM_ERRATA_742230
490 CONFIG_ARM_ERRATA_743622
491 CONFIG_ARM_ERRATA_751472
493 If set, the workarounds for these ARM errata are applied early
494 during U-Boot startup. Note that these options force the
495 workarounds to be applied; no CPU-type/version detection
496 exists, unlike the similar options in the Linux kernel. Do not
497 set these options unless they apply!
502 The frequency of the timer returned by get_timer().
503 get_timer() must operate in milliseconds and this CONFIG
504 option must be set to 1000.
506 - Linux Kernel Interface:
509 U-Boot stores all clock information in Hz
510 internally. For binary compatibility with older Linux
511 kernels (which expect the clocks passed in the
512 bd_info data to be in MHz) the environment variable
513 "clocks_in_mhz" can be defined so that U-Boot
514 converts clock data to MHZ before passing it to the
516 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
517 "clocks_in_mhz=1" is automatically included in the
520 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
522 When transferring memsize parameter to linux, some versions
523 expect it to be in bytes, others in MB.
524 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
528 New kernel versions are expecting firmware settings to be
529 passed using flattened device trees (based on open firmware
533 * New libfdt-based support
534 * Adds the "fdt" command
535 * The bootm command automatically updates the fdt
537 OF_CPU - The proper name of the cpus node (only required for
538 MPC512X and MPC5xxx based boards).
539 OF_SOC - The proper name of the soc node (only required for
540 MPC512X and MPC5xxx based boards).
541 OF_TBCLK - The timebase frequency.
542 OF_STDOUT_PATH - The path to the console device
544 boards with QUICC Engines require OF_QE to set UCC MAC
547 CONFIG_OF_BOARD_SETUP
549 Board code has addition modification that it wants to make
550 to the flat device tree before handing it off to the kernel
554 This define fills in the correct boot CPU in the boot
555 param header, the default value is zero if undefined.
559 U-Boot can detect if an IDE device is present or not.
560 If not, and this new config option is activated, U-Boot
561 removes the ATA node from the DTS before booting Linux,
562 so the Linux IDE driver does not probe the device and
563 crash. This is needed for buggy hardware (uc101) where
564 no pull down resistor is connected to the signal IDE5V_DD7.
566 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
568 This setting is mandatory for all boards that have only one
569 machine type and must be used to specify the machine type
570 number as it appears in the ARM machine registry
571 (see http://www.arm.linux.org.uk/developer/machines/).
572 Only boards that have multiple machine types supported
573 in a single configuration file and the machine type is
574 runtime discoverable, do not have to use this setting.
576 - vxWorks boot parameters:
578 bootvx constructs a valid bootline using the following
579 environments variables: bootfile, ipaddr, serverip, hostname.
580 It loads the vxWorks image pointed bootfile.
582 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
583 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
584 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
585 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
587 CONFIG_SYS_VXWORKS_ADD_PARAMS
589 Add it at the end of the bootline. E.g "u=username pw=secret"
591 Note: If a "bootargs" environment is defined, it will overwride
592 the defaults discussed just above.
594 - Cache Configuration:
595 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
596 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
597 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
599 - Cache Configuration for ARM:
600 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
602 CONFIG_SYS_PL310_BASE - Physical base address of PL310
603 controller register space
608 Define this if you want support for Amba PrimeCell PL010 UARTs.
612 Define this if you want support for Amba PrimeCell PL011 UARTs.
616 If you have Amba PrimeCell PL011 UARTs, set this variable to
617 the clock speed of the UARTs.
621 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
622 define this to a list of base addresses for each (supported)
623 port. See e.g. include/configs/versatile.h
625 CONFIG_PL011_SERIAL_RLCR
627 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
628 have separate receive and transmit line control registers. Set
629 this variable to initialize the extra register.
631 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
633 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
634 boot loader that has already initialized the UART. Define this
635 variable to flush the UART at init time.
639 Depending on board, define exactly one serial port
640 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
641 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
642 console by defining CONFIG_8xx_CONS_NONE
644 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
645 port routines must be defined elsewhere
646 (i.e. serial_init(), serial_getc(), ...)
649 Enables console device for a color framebuffer. Needs following
650 defines (cf. smiLynxEM, i8042)
651 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
653 VIDEO_HW_RECTFILL graphic chip supports
656 VIDEO_HW_BITBLT graphic chip supports
657 bit-blit (cf. smiLynxEM)
658 VIDEO_VISIBLE_COLS visible pixel columns
660 VIDEO_VISIBLE_ROWS visible pixel rows
661 VIDEO_PIXEL_SIZE bytes per pixel
662 VIDEO_DATA_FORMAT graphic data format
663 (0-5, cf. cfb_console.c)
664 VIDEO_FB_ADRS framebuffer address
665 VIDEO_KBD_INIT_FCT keyboard int fct
666 (i.e. i8042_kbd_init())
667 VIDEO_TSTC_FCT test char fct
669 VIDEO_GETC_FCT get char fct
671 CONFIG_CONSOLE_CURSOR cursor drawing on/off
672 (requires blink timer
674 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
675 CONFIG_CONSOLE_TIME display time/date info in
677 (requires CONFIG_CMD_DATE)
678 CONFIG_VIDEO_LOGO display Linux logo in
680 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
681 linux_logo.h for logo.
682 Requires CONFIG_VIDEO_LOGO
683 CONFIG_CONSOLE_EXTRA_INFO
684 additional board info beside
687 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
688 a limited number of ANSI escape sequences (cursor control,
689 erase functions and limited graphics rendition control).
691 When CONFIG_CFB_CONSOLE is defined, video console is
692 default i/o. Serial console can be forced with
693 environment 'console=serial'.
695 When CONFIG_SILENT_CONSOLE is defined, all console
696 messages (by U-Boot and Linux!) can be silenced with
697 the "silent" environment variable. See
698 doc/README.silent for more information.
701 CONFIG_BAUDRATE - in bps
702 Select one of the baudrates listed in
703 CONFIG_SYS_BAUDRATE_TABLE, see below.
704 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
706 - Console Rx buffer length
707 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
708 the maximum receive buffer length for the SMC.
709 This option is actual only for 82xx and 8xx possible.
710 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
711 must be defined, to setup the maximum idle timeout for
714 - Pre-Console Buffer:
715 Prior to the console being initialised (i.e. serial UART
716 initialised etc) all console output is silently discarded.
717 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
718 buffer any console messages prior to the console being
719 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
720 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
721 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
722 bytes are output before the console is initialised, the
723 earlier bytes are discarded.
725 'Sane' compilers will generate smaller code if
726 CONFIG_PRE_CON_BUF_SZ is a power of 2
728 - Safe printf() functions
729 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
730 the printf() functions. These are defined in
731 include/vsprintf.h and include snprintf(), vsnprintf() and
732 so on. Code size increase is approximately 300-500 bytes.
733 If this option is not given then these functions will
734 silently discard their buffer size argument - this means
735 you are not getting any overflow checking in this case.
737 - Boot Delay: CONFIG_BOOTDELAY - in seconds
738 Delay before automatically booting the default image;
739 set to -1 to disable autoboot.
740 set to -2 to autoboot with no delay and not check for abort
741 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
743 See doc/README.autoboot for these options that
744 work with CONFIG_BOOTDELAY. None are required.
745 CONFIG_BOOT_RETRY_TIME
746 CONFIG_BOOT_RETRY_MIN
747 CONFIG_AUTOBOOT_KEYED
748 CONFIG_AUTOBOOT_PROMPT
749 CONFIG_AUTOBOOT_DELAY_STR
750 CONFIG_AUTOBOOT_STOP_STR
751 CONFIG_AUTOBOOT_DELAY_STR2
752 CONFIG_AUTOBOOT_STOP_STR2
753 CONFIG_ZERO_BOOTDELAY_CHECK
754 CONFIG_RESET_TO_RETRY
758 Only needed when CONFIG_BOOTDELAY is enabled;
759 define a command string that is automatically executed
760 when no character is read on the console interface
761 within "Boot Delay" after reset.
764 This can be used to pass arguments to the bootm
765 command. The value of CONFIG_BOOTARGS goes into the
766 environment value "bootargs".
768 CONFIG_RAMBOOT and CONFIG_NFSBOOT
769 The value of these goes into the environment as
770 "ramboot" and "nfsboot" respectively, and can be used
771 as a convenience, when switching between booting from
777 When this option is #defined, the existence of the
778 environment variable "preboot" will be checked
779 immediately before starting the CONFIG_BOOTDELAY
780 countdown and/or running the auto-boot command resp.
781 entering interactive mode.
783 This feature is especially useful when "preboot" is
784 automatically generated or modified. For an example
785 see the LWMON board specific code: here "preboot" is
786 modified when the user holds down a certain
787 combination of keys on the (special) keyboard when
790 - Serial Download Echo Mode:
792 If defined to 1, all characters received during a
793 serial download (using the "loads" command) are
794 echoed back. This might be needed by some terminal
795 emulations (like "cu"), but may as well just take
796 time on others. This setting #define's the initial
797 value of the "loads_echo" environment variable.
799 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
801 Select one of the baudrates listed in
802 CONFIG_SYS_BAUDRATE_TABLE, see below.
805 Monitor commands can be included or excluded
806 from the build by using the #include files
807 <config_cmd_all.h> and #undef'ing unwanted
808 commands, or using <config_cmd_default.h>
809 and augmenting with additional #define's
812 The default command configuration includes all commands
813 except those marked below with a "*".
815 CONFIG_CMD_ASKENV * ask for env variable
816 CONFIG_CMD_BDI bdinfo
817 CONFIG_CMD_BEDBUG * Include BedBug Debugger
818 CONFIG_CMD_BMP * BMP support
819 CONFIG_CMD_BSP * Board specific commands
820 CONFIG_CMD_BOOTD bootd
821 CONFIG_CMD_CACHE * icache, dcache
822 CONFIG_CMD_CONSOLE coninfo
823 CONFIG_CMD_CRC32 * crc32
824 CONFIG_CMD_DATE * support for RTC, date/time...
825 CONFIG_CMD_DHCP * DHCP support
826 CONFIG_CMD_DIAG * Diagnostics
827 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
828 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
829 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
830 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
831 CONFIG_CMD_DTT * Digital Therm and Thermostat
832 CONFIG_CMD_ECHO echo arguments
833 CONFIG_CMD_EDITENV edit env variable
834 CONFIG_CMD_EEPROM * EEPROM read/write support
835 CONFIG_CMD_ELF * bootelf, bootvx
836 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
837 CONFIG_CMD_ENV_FLAGS * display details about env flags
838 CONFIG_CMD_EXPORTENV * export the environment
839 CONFIG_CMD_EXT2 * ext2 command support
840 CONFIG_CMD_EXT4 * ext4 command support
841 CONFIG_CMD_SAVEENV saveenv
842 CONFIG_CMD_FDC * Floppy Disk Support
843 CONFIG_CMD_FAT * FAT command support
844 CONFIG_CMD_FDOS * Dos diskette Support
845 CONFIG_CMD_FLASH flinfo, erase, protect
846 CONFIG_CMD_FPGA FPGA device initialization support
847 CONFIG_CMD_FUSE Device fuse support
848 CONFIG_CMD_GETTIME * Get time since boot
849 CONFIG_CMD_GO * the 'go' command (exec code)
850 CONFIG_CMD_GREPENV * search environment
851 CONFIG_CMD_HASH * calculate hash / digest
852 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
853 CONFIG_CMD_I2C * I2C serial bus support
854 CONFIG_CMD_IDE * IDE harddisk support
855 CONFIG_CMD_IMI iminfo
856 CONFIG_CMD_IMLS List all images found in NOR flash
857 CONFIG_CMD_IMLS_NAND List all images found in NAND flash
858 CONFIG_CMD_IMMAP * IMMR dump support
859 CONFIG_CMD_IMPORTENV * import an environment
860 CONFIG_CMD_INI * import data from an ini file into the env
861 CONFIG_CMD_IRQ * irqinfo
862 CONFIG_CMD_ITEST Integer/string test of 2 values
863 CONFIG_CMD_JFFS2 * JFFS2 Support
864 CONFIG_CMD_KGDB * kgdb
865 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
866 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
868 CONFIG_CMD_LOADB loadb
869 CONFIG_CMD_LOADS loads
870 CONFIG_CMD_MD5SUM print md5 message digest
871 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
872 CONFIG_CMD_MEMINFO * Display detailed memory information
873 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
875 CONFIG_CMD_MEMTEST mtest
876 CONFIG_CMD_MISC Misc functions like sleep etc
877 CONFIG_CMD_MMC * MMC memory mapped support
878 CONFIG_CMD_MII * MII utility commands
879 CONFIG_CMD_MTDPARTS * MTD partition support
880 CONFIG_CMD_NAND * NAND support
881 CONFIG_CMD_NET bootp, tftpboot, rarpboot
882 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
883 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
884 CONFIG_CMD_PCI * pciinfo
885 CONFIG_CMD_PCMCIA * PCMCIA support
886 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
888 CONFIG_CMD_PORTIO * Port I/O
889 CONFIG_CMD_READ * Read raw data from partition
890 CONFIG_CMD_REGINFO * Register dump
891 CONFIG_CMD_RUN run command in env variable
892 CONFIG_CMD_SANDBOX * sb command to access sandbox features
893 CONFIG_CMD_SAVES * save S record dump
894 CONFIG_CMD_SCSI * SCSI Support
895 CONFIG_CMD_SDRAM * print SDRAM configuration information
896 (requires CONFIG_CMD_I2C)
897 CONFIG_CMD_SETGETDCR Support for DCR Register access
899 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
900 CONFIG_CMD_SHA1SUM print sha1 memory digest
901 (requires CONFIG_CMD_MEMORY)
902 CONFIG_CMD_SOURCE "source" command Support
903 CONFIG_CMD_SPI * SPI serial bus support
904 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
905 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
906 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
907 CONFIG_CMD_TIMER * access to the system tick timer
908 CONFIG_CMD_USB * USB support
909 CONFIG_CMD_CDP * Cisco Discover Protocol support
910 CONFIG_CMD_MFSL * Microblaze FSL support
913 EXAMPLE: If you want all functions except of network
914 support you can write:
916 #include "config_cmd_all.h"
917 #undef CONFIG_CMD_NET
920 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
922 Note: Don't enable the "icache" and "dcache" commands
923 (configuration option CONFIG_CMD_CACHE) unless you know
924 what you (and your U-Boot users) are doing. Data
925 cache cannot be enabled on systems like the 8xx or
926 8260 (where accesses to the IMMR region must be
927 uncached), and it cannot be disabled on all other
928 systems where we (mis-) use the data cache to hold an
929 initial stack and some data.
932 XXX - this list needs to get updated!
936 If this variable is defined, U-Boot will use a device tree
937 to configure its devices, instead of relying on statically
938 compiled #defines in the board file. This option is
939 experimental and only available on a few boards. The device
940 tree is available in the global data as gd->fdt_blob.
942 U-Boot needs to get its device tree from somewhere. This can
943 be done using one of the two options below:
946 If this variable is defined, U-Boot will embed a device tree
947 binary in its image. This device tree file should be in the
948 board directory and called <soc>-<board>.dts. The binary file
949 is then picked up in board_init_f() and made available through
950 the global data structure as gd->blob.
953 If this variable is defined, U-Boot will build a device tree
954 binary. It will be called u-boot.dtb. Architecture-specific
955 code will locate it at run-time. Generally this works by:
957 cat u-boot.bin u-boot.dtb >image.bin
959 and in fact, U-Boot does this for you, creating a file called
960 u-boot-dtb.bin which is useful in the common case. You can
961 still use the individual files if you need something more
966 If this variable is defined, it enables watchdog
967 support for the SoC. There must be support in the SoC
968 specific code for a watchdog. For the 8xx and 8260
969 CPUs, the SIU Watchdog feature is enabled in the SYPCR
970 register. When supported for a specific SoC is
971 available, then no further board specific code should
975 When using a watchdog circuitry external to the used
976 SoC, then define this variable and provide board
977 specific code for the "hw_watchdog_reset" function.
980 CONFIG_VERSION_VARIABLE
981 If this variable is defined, an environment variable
982 named "ver" is created by U-Boot showing the U-Boot
983 version as printed by the "version" command.
984 Any change to this variable will be reverted at the
989 When CONFIG_CMD_DATE is selected, the type of the RTC
990 has to be selected, too. Define exactly one of the
993 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
994 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
995 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
996 CONFIG_RTC_MC146818 - use MC146818 RTC
997 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
998 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
999 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1000 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1001 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1002 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1003 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1004 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1007 Note that if the RTC uses I2C, then the I2C interface
1008 must also be configured. See I2C Support, below.
1011 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1012 CONFIG_PCA953X_INFO - enable pca953x info command
1014 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1015 chip-ngpio pairs that tell the PCA953X driver the number of
1016 pins supported by a particular chip.
1018 Note that if the GPIO device uses I2C, then the I2C interface
1019 must also be configured. See I2C Support, below.
1021 - Timestamp Support:
1023 When CONFIG_TIMESTAMP is selected, the timestamp
1024 (date and time) of an image is printed by image
1025 commands like bootm or iminfo. This option is
1026 automatically enabled when you select CONFIG_CMD_DATE .
1028 - Partition Labels (disklabels) Supported:
1029 Zero or more of the following:
1030 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1031 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1032 Intel architecture, USB sticks, etc.
1033 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1034 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1035 bootloader. Note 2TB partition limit; see
1037 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1039 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1040 CONFIG_CMD_SCSI) you must configure support for at
1041 least one non-MTD partition type as well.
1044 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1045 board configurations files but used nowhere!
1047 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1048 be performed by calling the function
1049 ide_set_reset(int reset)
1050 which has to be defined in a board specific file
1055 Set this to enable ATAPI support.
1060 Set this to enable support for disks larger than 137GB
1061 Also look at CONFIG_SYS_64BIT_LBA.
1062 Whithout these , LBA48 support uses 32bit variables and will 'only'
1063 support disks up to 2.1TB.
1065 CONFIG_SYS_64BIT_LBA:
1066 When enabled, makes the IDE subsystem use 64bit sector addresses.
1070 At the moment only there is only support for the
1071 SYM53C8XX SCSI controller; define
1072 CONFIG_SCSI_SYM53C8XX to enable it.
1074 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1075 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1076 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1077 maximum numbers of LUNs, SCSI ID's and target
1079 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1081 The environment variable 'scsidevs' is set to the number of
1082 SCSI devices found during the last scan.
1084 - NETWORK Support (PCI):
1086 Support for Intel 8254x/8257x gigabit chips.
1089 Utility code for direct access to the SPI bus on Intel 8257x.
1090 This does not do anything useful unless you set at least one
1091 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1093 CONFIG_E1000_SPI_GENERIC
1094 Allow generic access to the SPI bus on the Intel 8257x, for
1095 example with the "sspi" command.
1098 Management command for E1000 devices. When used on devices
1099 with SPI support you can reprogram the EEPROM from U-Boot.
1101 CONFIG_E1000_FALLBACK_MAC
1102 default MAC for empty EEPROM after production.
1105 Support for Intel 82557/82559/82559ER chips.
1106 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1107 write routine for first time initialisation.
1110 Support for Digital 2114x chips.
1111 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1112 modem chip initialisation (KS8761/QS6611).
1115 Support for National dp83815 chips.
1118 Support for National dp8382[01] gigabit chips.
1120 - NETWORK Support (other):
1122 CONFIG_DRIVER_AT91EMAC
1123 Support for AT91RM9200 EMAC.
1126 Define this to use reduced MII inteface
1128 CONFIG_DRIVER_AT91EMAC_QUIET
1129 If this defined, the driver is quiet.
1130 The driver doen't show link status messages.
1132 CONFIG_CALXEDA_XGMAC
1133 Support for the Calxeda XGMAC device
1136 Support for SMSC's LAN91C96 chips.
1138 CONFIG_LAN91C96_BASE
1139 Define this to hold the physical address
1140 of the LAN91C96's I/O space
1142 CONFIG_LAN91C96_USE_32_BIT
1143 Define this to enable 32 bit addressing
1146 Support for SMSC's LAN91C111 chip
1148 CONFIG_SMC91111_BASE
1149 Define this to hold the physical address
1150 of the device (I/O space)
1152 CONFIG_SMC_USE_32_BIT
1153 Define this if data bus is 32 bits
1155 CONFIG_SMC_USE_IOFUNCS
1156 Define this to use i/o functions instead of macros
1157 (some hardware wont work with macros)
1159 CONFIG_DRIVER_TI_EMAC
1160 Support for davinci emac
1162 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1163 Define this if you have more then 3 PHYs.
1166 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1168 CONFIG_FTGMAC100_EGIGA
1169 Define this to use GE link update with gigabit PHY.
1170 Define this if FTGMAC100 is connected to gigabit PHY.
1171 If your system has 10/100 PHY only, it might not occur
1172 wrong behavior. Because PHY usually return timeout or
1173 useless data when polling gigabit status and gigabit
1174 control registers. This behavior won't affect the
1175 correctnessof 10/100 link speed update.
1178 Support for SMSC's LAN911x and LAN921x chips
1181 Define this to hold the physical address
1182 of the device (I/O space)
1184 CONFIG_SMC911X_32_BIT
1185 Define this if data bus is 32 bits
1187 CONFIG_SMC911X_16_BIT
1188 Define this if data bus is 16 bits. If your processor
1189 automatically converts one 32 bit word to two 16 bit
1190 words you may also try CONFIG_SMC911X_32_BIT.
1193 Support for Renesas on-chip Ethernet controller
1195 CONFIG_SH_ETHER_USE_PORT
1196 Define the number of ports to be used
1198 CONFIG_SH_ETHER_PHY_ADDR
1199 Define the ETH PHY's address
1201 CONFIG_SH_ETHER_CACHE_WRITEBACK
1202 If this option is set, the driver enables cache flush.
1205 CONFIG_GENERIC_LPC_TPM
1206 Support for generic parallel port TPM devices. Only one device
1207 per system is supported at this time.
1209 CONFIG_TPM_TIS_BASE_ADDRESS
1210 Base address where the generic TPM device is mapped
1211 to. Contemporary x86 systems usually map it at
1215 At the moment only the UHCI host controller is
1216 supported (PIP405, MIP405, MPC5200); define
1217 CONFIG_USB_UHCI to enable it.
1218 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1219 and define CONFIG_USB_STORAGE to enable the USB
1222 Supported are USB Keyboards and USB Floppy drives
1224 MPC5200 USB requires additional defines:
1226 for 528 MHz Clock: 0x0001bbbb
1230 for differential drivers: 0x00001000
1231 for single ended drivers: 0x00005000
1232 for differential drivers on PSC3: 0x00000100
1233 for single ended drivers on PSC3: 0x00004100
1234 CONFIG_SYS_USB_EVENT_POLL
1235 May be defined to allow interrupt polling
1236 instead of using asynchronous interrupts
1238 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1239 txfilltuning field in the EHCI controller on reset.
1242 Define the below if you wish to use the USB console.
1243 Once firmware is rebuilt from a serial console issue the
1244 command "setenv stdin usbtty; setenv stdout usbtty" and
1245 attach your USB cable. The Unix command "dmesg" should print
1246 it has found a new device. The environment variable usbtty
1247 can be set to gserial or cdc_acm to enable your device to
1248 appear to a USB host as a Linux gserial device or a
1249 Common Device Class Abstract Control Model serial device.
1250 If you select usbtty = gserial you should be able to enumerate
1252 # modprobe usbserial vendor=0xVendorID product=0xProductID
1253 else if using cdc_acm, simply setting the environment
1254 variable usbtty to be cdc_acm should suffice. The following
1255 might be defined in YourBoardName.h
1258 Define this to build a UDC device
1261 Define this to have a tty type of device available to
1262 talk to the UDC device
1265 Define this to enable the high speed support for usb
1266 device and usbtty. If this feature is enabled, a routine
1267 int is_usbd_high_speed(void)
1268 also needs to be defined by the driver to dynamically poll
1269 whether the enumeration has succeded at high speed or full
1272 CONFIG_SYS_CONSOLE_IS_IN_ENV
1273 Define this if you want stdin, stdout &/or stderr to
1277 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1278 Derive USB clock from external clock "blah"
1279 - CONFIG_SYS_USB_EXTC_CLK 0x02
1281 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1282 Derive USB clock from brgclk
1283 - CONFIG_SYS_USB_BRG_CLK 0x04
1285 If you have a USB-IF assigned VendorID then you may wish to
1286 define your own vendor specific values either in BoardName.h
1287 or directly in usbd_vendor_info.h. If you don't define
1288 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1289 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1290 should pretend to be a Linux device to it's target host.
1292 CONFIG_USBD_MANUFACTURER
1293 Define this string as the name of your company for
1294 - CONFIG_USBD_MANUFACTURER "my company"
1296 CONFIG_USBD_PRODUCT_NAME
1297 Define this string as the name of your product
1298 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1300 CONFIG_USBD_VENDORID
1301 Define this as your assigned Vendor ID from the USB
1302 Implementors Forum. This *must* be a genuine Vendor ID
1303 to avoid polluting the USB namespace.
1304 - CONFIG_USBD_VENDORID 0xFFFF
1306 CONFIG_USBD_PRODUCTID
1307 Define this as the unique Product ID
1309 - CONFIG_USBD_PRODUCTID 0xFFFF
1311 - ULPI Layer Support:
1312 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1313 the generic ULPI layer. The generic layer accesses the ULPI PHY
1314 via the platform viewport, so you need both the genric layer and
1315 the viewport enabled. Currently only Chipidea/ARC based
1316 viewport is supported.
1317 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1318 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1319 If your ULPI phy needs a different reference clock than the
1320 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1321 the appropriate value in Hz.
1324 The MMC controller on the Intel PXA is supported. To
1325 enable this define CONFIG_MMC. The MMC can be
1326 accessed from the boot prompt by mapping the device
1327 to physical memory similar to flash. Command line is
1328 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1329 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1332 Support for Renesas on-chip MMCIF controller
1334 CONFIG_SH_MMCIF_ADDR
1335 Define the base address of MMCIF registers
1338 Define the clock frequency for MMCIF
1340 - USB Device Firmware Update (DFU) class support:
1342 This enables the USB portion of the DFU USB class
1345 This enables the command "dfu" which is used to have
1346 U-Boot create a DFU class device via USB. This command
1347 requires that the "dfu_alt_info" environment variable be
1348 set and define the alt settings to expose to the host.
1351 This enables support for exposing (e)MMC devices via DFU.
1354 This enables support for exposing NAND devices via DFU.
1356 CONFIG_SYS_DFU_MAX_FILE_SIZE
1357 When updating files rather than the raw storage device,
1358 we use a static buffer to copy the file into and then write
1359 the buffer once we've been given the whole file. Define
1360 this to the maximum filesize (in bytes) for the buffer.
1361 Default is 4 MiB if undefined.
1363 - Journaling Flash filesystem support:
1364 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1365 CONFIG_JFFS2_NAND_DEV
1366 Define these for a default partition on a NAND device
1368 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1369 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1370 Define these for a default partition on a NOR device
1372 CONFIG_SYS_JFFS_CUSTOM_PART
1373 Define this to create an own partition. You have to provide a
1374 function struct part_info* jffs2_part_info(int part_num)
1376 If you define only one JFFS2 partition you may also want to
1377 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1378 to disable the command chpart. This is the default when you
1379 have not defined a custom partition
1381 - FAT(File Allocation Table) filesystem write function support:
1384 Define this to enable support for saving memory data as a
1385 file in FAT formatted partition.
1387 This will also enable the command "fatwrite" enabling the
1388 user to write files to FAT.
1390 CBFS (Coreboot Filesystem) support
1393 Define this to enable support for reading from a Coreboot
1394 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1400 Define this to enable standard (PC-Style) keyboard
1404 Standard PC keyboard driver with US (is default) and
1405 GERMAN key layout (switch via environment 'keymap=de') support.
1406 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1407 for cfb_console. Supports cursor blinking.
1412 Define this to enable video support (for output to
1415 CONFIG_VIDEO_CT69000
1417 Enable Chips & Technologies 69000 Video chip
1419 CONFIG_VIDEO_SMI_LYNXEM
1420 Enable Silicon Motion SMI 712/710/810 Video chip. The
1421 video output is selected via environment 'videoout'
1422 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1425 For the CT69000 and SMI_LYNXEM drivers, videomode is
1426 selected via environment 'videomode'. Two different ways
1428 - "videomode=num" 'num' is a standard LiLo mode numbers.
1429 Following standard modes are supported (* is default):
1431 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1432 -------------+---------------------------------------------
1433 8 bits | 0x301* 0x303 0x305 0x161 0x307
1434 15 bits | 0x310 0x313 0x316 0x162 0x319
1435 16 bits | 0x311 0x314 0x317 0x163 0x31A
1436 24 bits | 0x312 0x315 0x318 ? 0x31B
1437 -------------+---------------------------------------------
1438 (i.e. setenv videomode 317; saveenv; reset;)
1440 - "videomode=bootargs" all the video parameters are parsed
1441 from the bootargs. (See drivers/video/videomodes.c)
1444 CONFIG_VIDEO_SED13806
1445 Enable Epson SED13806 driver. This driver supports 8bpp
1446 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1447 or CONFIG_VIDEO_SED13806_16BPP
1450 Enable the Freescale DIU video driver. Reference boards for
1451 SOCs that have a DIU should define this macro to enable DIU
1452 support, and should also define these other macros:
1458 CONFIG_VIDEO_SW_CURSOR
1459 CONFIG_VGA_AS_SINGLE_DEVICE
1461 CONFIG_VIDEO_BMP_LOGO
1463 The DIU driver will look for the 'video-mode' environment
1464 variable, and if defined, enable the DIU as a console during
1465 boot. See the documentation file README.video for a
1466 description of this variable.
1470 Enable the VGA video / BIOS for x86. The alternative if you
1471 are using coreboot is to use the coreboot frame buffer
1478 Define this to enable a custom keyboard support.
1479 This simply calls drv_keyboard_init() which must be
1480 defined in your board-specific files.
1481 The only board using this so far is RBC823.
1483 - LCD Support: CONFIG_LCD
1485 Define this to enable LCD support (for output to LCD
1486 display); also select one of the supported displays
1487 by defining one of these:
1491 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1493 CONFIG_NEC_NL6448AC33:
1495 NEC NL6448AC33-18. Active, color, single scan.
1497 CONFIG_NEC_NL6448BC20
1499 NEC NL6448BC20-08. 6.5", 640x480.
1500 Active, color, single scan.
1502 CONFIG_NEC_NL6448BC33_54
1504 NEC NL6448BC33-54. 10.4", 640x480.
1505 Active, color, single scan.
1509 Sharp 320x240. Active, color, single scan.
1510 It isn't 16x9, and I am not sure what it is.
1512 CONFIG_SHARP_LQ64D341
1514 Sharp LQ64D341 display, 640x480.
1515 Active, color, single scan.
1519 HLD1045 display, 640x480.
1520 Active, color, single scan.
1524 Optrex CBL50840-2 NF-FW 99 22 M5
1526 Hitachi LMG6912RPFC-00T
1530 320x240. Black & white.
1532 Normally display is black on white background; define
1533 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1535 CONFIG_LCD_ALIGNMENT
1537 Normally the LCD is page-aligned (tyically 4KB). If this is
1538 defined then the LCD will be aligned to this value instead.
1539 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1540 here, since it is cheaper to change data cache settings on
1541 a per-section basis.
1543 CONFIG_CONSOLE_SCROLL_LINES
1545 When the console need to be scrolled, this is the number of
1546 lines to scroll by. It defaults to 1. Increasing this makes
1547 the console jump but can help speed up operation when scrolling
1552 Support drawing of RLE8-compressed bitmaps on the LCD.
1556 Enables an 'i2c edid' command which can read EDID
1557 information over I2C from an attached LCD display.
1559 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1561 If this option is set, the environment is checked for
1562 a variable "splashimage". If found, the usual display
1563 of logo, copyright and system information on the LCD
1564 is suppressed and the BMP image at the address
1565 specified in "splashimage" is loaded instead. The
1566 console is redirected to the "nulldev", too. This
1567 allows for a "silent" boot where a splash screen is
1568 loaded very quickly after power-on.
1570 CONFIG_SPLASHIMAGE_GUARD
1572 If this option is set, then U-Boot will prevent the environment
1573 variable "splashimage" from being set to a problematic address
1574 (see README.displaying-bmps and README.arm-unaligned-accesses).
1575 This option is useful for targets where, due to alignment
1576 restrictions, an improperly aligned BMP image will cause a data
1577 abort. If you think you will not have problems with unaligned
1578 accesses (for example because your toolchain prevents them)
1579 there is no need to set this option.
1581 CONFIG_SPLASH_SCREEN_ALIGN
1583 If this option is set the splash image can be freely positioned
1584 on the screen. Environment variable "splashpos" specifies the
1585 position as "x,y". If a positive number is given it is used as
1586 number of pixel from left/top. If a negative number is given it
1587 is used as number of pixel from right/bottom. You can also
1588 specify 'm' for centering the image.
1591 setenv splashpos m,m
1592 => image at center of screen
1594 setenv splashpos 30,20
1595 => image at x = 30 and y = 20
1597 setenv splashpos -10,m
1598 => vertically centered image
1599 at x = dspWidth - bmpWidth - 9
1601 CONFIG_SPLASH_SCREEN_PREPARE
1603 If this option is set then the board_splash_screen_prepare()
1604 function, which must be defined in your code, is called as part
1605 of the splash screen display sequence. It gives the board an
1606 opportunity to prepare the splash image data before it is
1607 processed and sent to the frame buffer by U-Boot.
1609 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1611 If this option is set, additionally to standard BMP
1612 images, gzipped BMP images can be displayed via the
1613 splashscreen support or the bmp command.
1615 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1617 If this option is set, 8-bit RLE compressed BMP images
1618 can be displayed via the splashscreen support or the
1621 - Do compresssing for memory range:
1624 If this option is set, it would use zlib deflate method
1625 to compress the specified memory at its best effort.
1627 - Compression support:
1630 If this option is set, support for bzip2 compressed
1631 images is included. If not, only uncompressed and gzip
1632 compressed images are supported.
1634 NOTE: the bzip2 algorithm requires a lot of RAM, so
1635 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1640 If this option is set, support for lzma compressed
1643 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1644 requires an amount of dynamic memory that is given by the
1647 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1649 Where lc and lp stand for, respectively, Literal context bits
1650 and Literal pos bits.
1652 This value is upper-bounded by 14MB in the worst case. Anyway,
1653 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1654 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1655 a very small buffer.
1657 Use the lzmainfo tool to determinate the lc and lp values and
1658 then calculate the amount of needed dynamic memory (ensuring
1659 the appropriate CONFIG_SYS_MALLOC_LEN value).
1664 The address of PHY on MII bus.
1666 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1668 The clock frequency of the MII bus
1672 If this option is set, support for speed/duplex
1673 detection of gigabit PHY is included.
1675 CONFIG_PHY_RESET_DELAY
1677 Some PHY like Intel LXT971A need extra delay after
1678 reset before any MII register access is possible.
1679 For such PHY, set this option to the usec delay
1680 required. (minimum 300usec for LXT971A)
1682 CONFIG_PHY_CMD_DELAY (ppc4xx)
1684 Some PHY like Intel LXT971A need extra delay after
1685 command issued before MII status register can be read
1695 Define a default value for Ethernet address to use
1696 for the respective Ethernet interface, in case this
1697 is not determined automatically.
1702 Define a default value for the IP address to use for
1703 the default Ethernet interface, in case this is not
1704 determined through e.g. bootp.
1705 (Environment variable "ipaddr")
1707 - Server IP address:
1710 Defines a default value for the IP address of a TFTP
1711 server to contact when using the "tftboot" command.
1712 (Environment variable "serverip")
1714 CONFIG_KEEP_SERVERADDR
1716 Keeps the server's MAC address, in the env 'serveraddr'
1717 for passing to bootargs (like Linux's netconsole option)
1719 - Gateway IP address:
1722 Defines a default value for the IP address of the
1723 default router where packets to other networks are
1725 (Environment variable "gatewayip")
1730 Defines a default value for the subnet mask (or
1731 routing prefix) which is used to determine if an IP
1732 address belongs to the local subnet or needs to be
1733 forwarded through a router.
1734 (Environment variable "netmask")
1736 - Multicast TFTP Mode:
1739 Defines whether you want to support multicast TFTP as per
1740 rfc-2090; for example to work with atftp. Lets lots of targets
1741 tftp down the same boot image concurrently. Note: the Ethernet
1742 driver in use must provide a function: mcast() to join/leave a
1745 - BOOTP Recovery Mode:
1746 CONFIG_BOOTP_RANDOM_DELAY
1748 If you have many targets in a network that try to
1749 boot using BOOTP, you may want to avoid that all
1750 systems send out BOOTP requests at precisely the same
1751 moment (which would happen for instance at recovery
1752 from a power failure, when all systems will try to
1753 boot, thus flooding the BOOTP server. Defining
1754 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1755 inserted before sending out BOOTP requests. The
1756 following delays are inserted then:
1758 1st BOOTP request: delay 0 ... 1 sec
1759 2nd BOOTP request: delay 0 ... 2 sec
1760 3rd BOOTP request: delay 0 ... 4 sec
1762 BOOTP requests: delay 0 ... 8 sec
1764 - DHCP Advanced Options:
1765 You can fine tune the DHCP functionality by defining
1766 CONFIG_BOOTP_* symbols:
1768 CONFIG_BOOTP_SUBNETMASK
1769 CONFIG_BOOTP_GATEWAY
1770 CONFIG_BOOTP_HOSTNAME
1771 CONFIG_BOOTP_NISDOMAIN
1772 CONFIG_BOOTP_BOOTPATH
1773 CONFIG_BOOTP_BOOTFILESIZE
1776 CONFIG_BOOTP_SEND_HOSTNAME
1777 CONFIG_BOOTP_NTPSERVER
1778 CONFIG_BOOTP_TIMEOFFSET
1779 CONFIG_BOOTP_VENDOREX
1780 CONFIG_BOOTP_MAY_FAIL
1782 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1783 environment variable, not the BOOTP server.
1785 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1786 after the configured retry count, the call will fail
1787 instead of starting over. This can be used to fail over
1788 to Link-local IP address configuration if the DHCP server
1791 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1792 serverip from a DHCP server, it is possible that more
1793 than one DNS serverip is offered to the client.
1794 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1795 serverip will be stored in the additional environment
1796 variable "dnsip2". The first DNS serverip is always
1797 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1800 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1801 to do a dynamic update of a DNS server. To do this, they
1802 need the hostname of the DHCP requester.
1803 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1804 of the "hostname" environment variable is passed as
1805 option 12 to the DHCP server.
1807 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1809 A 32bit value in microseconds for a delay between
1810 receiving a "DHCP Offer" and sending the "DHCP Request".
1811 This fixes a problem with certain DHCP servers that don't
1812 respond 100% of the time to a "DHCP request". E.g. On an
1813 AT91RM9200 processor running at 180MHz, this delay needed
1814 to be *at least* 15,000 usec before a Windows Server 2003
1815 DHCP server would reply 100% of the time. I recommend at
1816 least 50,000 usec to be safe. The alternative is to hope
1817 that one of the retries will be successful but note that
1818 the DHCP timeout and retry process takes a longer than
1821 - Link-local IP address negotiation:
1822 Negotiate with other link-local clients on the local network
1823 for an address that doesn't require explicit configuration.
1824 This is especially useful if a DHCP server cannot be guaranteed
1825 to exist in all environments that the device must operate.
1827 See doc/README.link-local for more information.
1830 CONFIG_CDP_DEVICE_ID
1832 The device id used in CDP trigger frames.
1834 CONFIG_CDP_DEVICE_ID_PREFIX
1836 A two character string which is prefixed to the MAC address
1841 A printf format string which contains the ascii name of
1842 the port. Normally is set to "eth%d" which sets
1843 eth0 for the first Ethernet, eth1 for the second etc.
1845 CONFIG_CDP_CAPABILITIES
1847 A 32bit integer which indicates the device capabilities;
1848 0x00000010 for a normal host which does not forwards.
1852 An ascii string containing the version of the software.
1856 An ascii string containing the name of the platform.
1860 A 32bit integer sent on the trigger.
1862 CONFIG_CDP_POWER_CONSUMPTION
1864 A 16bit integer containing the power consumption of the
1865 device in .1 of milliwatts.
1867 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1869 A byte containing the id of the VLAN.
1871 - Status LED: CONFIG_STATUS_LED
1873 Several configurations allow to display the current
1874 status using a LED. For instance, the LED will blink
1875 fast while running U-Boot code, stop blinking as
1876 soon as a reply to a BOOTP request was received, and
1877 start blinking slow once the Linux kernel is running
1878 (supported by a status LED driver in the Linux
1879 kernel). Defining CONFIG_STATUS_LED enables this
1882 - CAN Support: CONFIG_CAN_DRIVER
1884 Defining CONFIG_CAN_DRIVER enables CAN driver support
1885 on those systems that support this (optional)
1886 feature, like the TQM8xxL modules.
1888 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1890 These enable I2C serial bus commands. Defining either of
1891 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1892 include the appropriate I2C driver for the selected CPU.
1894 This will allow you to use i2c commands at the u-boot
1895 command line (as long as you set CONFIG_CMD_I2C in
1896 CONFIG_COMMANDS) and communicate with i2c based realtime
1897 clock chips. See common/cmd_i2c.c for a description of the
1898 command line interface.
1900 CONFIG_HARD_I2C selects a hardware I2C controller.
1902 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1903 bit-banging) driver instead of CPM or similar hardware
1906 There are several other quantities that must also be
1907 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1909 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1910 to be the frequency (in Hz) at which you wish your i2c bus
1911 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1912 the CPU's i2c node address).
1914 Now, the u-boot i2c code for the mpc8xx
1915 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1916 and so its address should therefore be cleared to 0 (See,
1917 eg, MPC823e User's Manual p.16-473). So, set
1918 CONFIG_SYS_I2C_SLAVE to 0.
1920 CONFIG_SYS_I2C_INIT_MPC5XXX
1922 When a board is reset during an i2c bus transfer
1923 chips might think that the current transfer is still
1924 in progress. Reset the slave devices by sending start
1925 commands until the slave device responds.
1927 That's all that's required for CONFIG_HARD_I2C.
1929 If you use the software i2c interface (CONFIG_SOFT_I2C)
1930 then the following macros need to be defined (examples are
1931 from include/configs/lwmon.h):
1935 (Optional). Any commands necessary to enable the I2C
1936 controller or configure ports.
1938 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1942 (Only for MPC8260 CPU). The I/O port to use (the code
1943 assumes both bits are on the same port). Valid values
1944 are 0..3 for ports A..D.
1948 The code necessary to make the I2C data line active
1949 (driven). If the data line is open collector, this
1952 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1956 The code necessary to make the I2C data line tri-stated
1957 (inactive). If the data line is open collector, this
1960 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1964 Code that returns true if the I2C data line is high,
1967 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1971 If <bit> is true, sets the I2C data line high. If it
1972 is false, it clears it (low).
1974 eg: #define I2C_SDA(bit) \
1975 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1976 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1980 If <bit> is true, sets the I2C clock line high. If it
1981 is false, it clears it (low).
1983 eg: #define I2C_SCL(bit) \
1984 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1985 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1989 This delay is invoked four times per clock cycle so this
1990 controls the rate of data transfer. The data rate thus
1991 is 1 / (I2C_DELAY * 4). Often defined to be something
1994 #define I2C_DELAY udelay(2)
1996 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1998 If your arch supports the generic GPIO framework (asm/gpio.h),
1999 then you may alternatively define the two GPIOs that are to be
2000 used as SCL / SDA. Any of the previous I2C_xxx macros will
2001 have GPIO-based defaults assigned to them as appropriate.
2003 You should define these to the GPIO value as given directly to
2004 the generic GPIO functions.
2006 CONFIG_SYS_I2C_INIT_BOARD
2008 When a board is reset during an i2c bus transfer
2009 chips might think that the current transfer is still
2010 in progress. On some boards it is possible to access
2011 the i2c SCLK line directly, either by using the
2012 processor pin as a GPIO or by having a second pin
2013 connected to the bus. If this option is defined a
2014 custom i2c_init_board() routine in boards/xxx/board.c
2015 is run early in the boot sequence.
2017 CONFIG_SYS_I2C_BOARD_LATE_INIT
2019 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2020 defined a custom i2c_board_late_init() routine in
2021 boards/xxx/board.c is run AFTER the operations in i2c_init()
2022 is completed. This callpoint can be used to unreset i2c bus
2023 using CPU i2c controller register accesses for CPUs whose i2c
2024 controller provide such a method. It is called at the end of
2025 i2c_init() to allow i2c_init operations to setup the i2c bus
2026 controller on the CPU (e.g. setting bus speed & slave address).
2028 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2030 This option enables configuration of bi_iic_fast[] flags
2031 in u-boot bd_info structure based on u-boot environment
2032 variable "i2cfast". (see also i2cfast)
2034 CONFIG_I2C_MULTI_BUS
2036 This option allows the use of multiple I2C buses, each of which
2037 must have a controller. At any point in time, only one bus is
2038 active. To switch to a different bus, use the 'i2c dev' command.
2039 Note that bus numbering is zero-based.
2041 CONFIG_SYS_I2C_NOPROBES
2043 This option specifies a list of I2C devices that will be skipped
2044 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2045 is set, specify a list of bus-device pairs. Otherwise, specify
2046 a 1D array of device addresses
2049 #undef CONFIG_I2C_MULTI_BUS
2050 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2052 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2054 #define CONFIG_I2C_MULTI_BUS
2055 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2057 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2059 CONFIG_SYS_SPD_BUS_NUM
2061 If defined, then this indicates the I2C bus number for DDR SPD.
2062 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2064 CONFIG_SYS_RTC_BUS_NUM
2066 If defined, then this indicates the I2C bus number for the RTC.
2067 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2069 CONFIG_SYS_DTT_BUS_NUM
2071 If defined, then this indicates the I2C bus number for the DTT.
2072 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2074 CONFIG_SYS_I2C_DTT_ADDR:
2076 If defined, specifies the I2C address of the DTT device.
2077 If not defined, then U-Boot uses predefined value for
2078 specified DTT device.
2082 Define this option if you want to use Freescale's I2C driver in
2083 drivers/i2c/fsl_i2c.c.
2087 Define this option if you have I2C devices reached over 1 .. n
2088 I2C Muxes like the pca9544a. This option addes a new I2C
2089 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
2090 new I2C Bus to the existing I2C Busses. If you select the
2091 new Bus with "i2c dev", u-bbot sends first the commandos for
2092 the muxes to activate this new "bus".
2094 CONFIG_I2C_MULTI_BUS must be also defined, to use this
2098 Adding a new I2C Bus reached over 2 pca9544a muxes
2099 The First mux with address 70 and channel 6
2100 The Second mux with address 71 and channel 4
2102 => i2c bus pca9544a:70:6:pca9544a:71:4
2104 Use the "i2c bus" command without parameter, to get a list
2105 of I2C Busses with muxes:
2108 Busses reached over muxes:
2110 reached over Mux(es):
2113 reached over Mux(es):
2118 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2119 u-boot first sends the command to the mux@70 to enable
2120 channel 6, and then the command to the mux@71 to enable
2123 After that, you can use the "normal" i2c commands as
2124 usual to communicate with your I2C devices behind
2127 This option is actually implemented for the bitbanging
2128 algorithm in common/soft_i2c.c and for the Hardware I2C
2129 Bus on the MPC8260. But it should be not so difficult
2130 to add this option to other architectures.
2132 CONFIG_SOFT_I2C_READ_REPEATED_START
2134 defining this will force the i2c_read() function in
2135 the soft_i2c driver to perform an I2C repeated start
2136 between writing the address pointer and reading the
2137 data. If this define is omitted the default behaviour
2138 of doing a stop-start sequence will be used. Most I2C
2139 devices can use either method, but some require one or
2142 - SPI Support: CONFIG_SPI
2144 Enables SPI driver (so far only tested with
2145 SPI EEPROM, also an instance works with Crystal A/D and
2146 D/As on the SACSng board)
2150 Enables the driver for SPI controller on SuperH. Currently
2151 only SH7757 is supported.
2155 Enables extended (16-bit) SPI EEPROM addressing.
2156 (symmetrical to CONFIG_I2C_X)
2160 Enables a software (bit-bang) SPI driver rather than
2161 using hardware support. This is a general purpose
2162 driver that only requires three general I/O port pins
2163 (two outputs, one input) to function. If this is
2164 defined, the board configuration must define several
2165 SPI configuration items (port pins to use, etc). For
2166 an example, see include/configs/sacsng.h.
2170 Enables a hardware SPI driver for general-purpose reads
2171 and writes. As with CONFIG_SOFT_SPI, the board configuration
2172 must define a list of chip-select function pointers.
2173 Currently supported on some MPC8xxx processors. For an
2174 example, see include/configs/mpc8349emds.h.
2178 Enables the driver for the SPI controllers on i.MX and MXC
2179 SoCs. Currently i.MX31/35/51 are supported.
2181 - FPGA Support: CONFIG_FPGA
2183 Enables FPGA subsystem.
2185 CONFIG_FPGA_<vendor>
2187 Enables support for specific chip vendors.
2190 CONFIG_FPGA_<family>
2192 Enables support for FPGA family.
2193 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2197 Specify the number of FPGA devices to support.
2199 CONFIG_SYS_FPGA_PROG_FEEDBACK
2201 Enable printing of hash marks during FPGA configuration.
2203 CONFIG_SYS_FPGA_CHECK_BUSY
2205 Enable checks on FPGA configuration interface busy
2206 status by the configuration function. This option
2207 will require a board or device specific function to
2212 If defined, a function that provides delays in the FPGA
2213 configuration driver.
2215 CONFIG_SYS_FPGA_CHECK_CTRLC
2216 Allow Control-C to interrupt FPGA configuration
2218 CONFIG_SYS_FPGA_CHECK_ERROR
2220 Check for configuration errors during FPGA bitfile
2221 loading. For example, abort during Virtex II
2222 configuration if the INIT_B line goes low (which
2223 indicated a CRC error).
2225 CONFIG_SYS_FPGA_WAIT_INIT
2227 Maximum time to wait for the INIT_B line to deassert
2228 after PROB_B has been deasserted during a Virtex II
2229 FPGA configuration sequence. The default time is 500
2232 CONFIG_SYS_FPGA_WAIT_BUSY
2234 Maximum time to wait for BUSY to deassert during
2235 Virtex II FPGA configuration. The default is 5 ms.
2237 CONFIG_SYS_FPGA_WAIT_CONFIG
2239 Time to wait after FPGA configuration. The default is
2242 - Configuration Management:
2245 If defined, this string will be added to the U-Boot
2246 version information (U_BOOT_VERSION)
2248 - Vendor Parameter Protection:
2250 U-Boot considers the values of the environment
2251 variables "serial#" (Board Serial Number) and
2252 "ethaddr" (Ethernet Address) to be parameters that
2253 are set once by the board vendor / manufacturer, and
2254 protects these variables from casual modification by
2255 the user. Once set, these variables are read-only,
2256 and write or delete attempts are rejected. You can
2257 change this behaviour:
2259 If CONFIG_ENV_OVERWRITE is #defined in your config
2260 file, the write protection for vendor parameters is
2261 completely disabled. Anybody can change or delete
2264 Alternatively, if you #define _both_ CONFIG_ETHADDR
2265 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2266 Ethernet address is installed in the environment,
2267 which can be changed exactly ONCE by the user. [The
2268 serial# is unaffected by this, i. e. it remains
2271 The same can be accomplished in a more flexible way
2272 for any variable by configuring the type of access
2273 to allow for those variables in the ".flags" variable
2274 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2279 Define this variable to enable the reservation of
2280 "protected RAM", i. e. RAM which is not overwritten
2281 by U-Boot. Define CONFIG_PRAM to hold the number of
2282 kB you want to reserve for pRAM. You can overwrite
2283 this default value by defining an environment
2284 variable "pram" to the number of kB you want to
2285 reserve. Note that the board info structure will
2286 still show the full amount of RAM. If pRAM is
2287 reserved, a new environment variable "mem" will
2288 automatically be defined to hold the amount of
2289 remaining RAM in a form that can be passed as boot
2290 argument to Linux, for instance like that:
2292 setenv bootargs ... mem=\${mem}
2295 This way you can tell Linux not to use this memory,
2296 either, which results in a memory region that will
2297 not be affected by reboots.
2299 *WARNING* If your board configuration uses automatic
2300 detection of the RAM size, you must make sure that
2301 this memory test is non-destructive. So far, the
2302 following board configurations are known to be
2305 IVMS8, IVML24, SPD8xx, TQM8xxL,
2306 HERMES, IP860, RPXlite, LWMON,
2309 - Access to physical memory region (> 4GB)
2310 Some basic support is provided for operations on memory not
2311 normally accessible to U-Boot - e.g. some architectures
2312 support access to more than 4GB of memory on 32-bit
2313 machines using physical address extension or similar.
2314 Define CONFIG_PHYSMEM to access this basic support, which
2315 currently only supports clearing the memory.
2320 Define this variable to stop the system in case of a
2321 fatal error, so that you have to reset it manually.
2322 This is probably NOT a good idea for an embedded
2323 system where you want the system to reboot
2324 automatically as fast as possible, but it may be
2325 useful during development since you can try to debug
2326 the conditions that lead to the situation.
2328 CONFIG_NET_RETRY_COUNT
2330 This variable defines the number of retries for
2331 network operations like ARP, RARP, TFTP, or BOOTP
2332 before giving up the operation. If not defined, a
2333 default value of 5 is used.
2337 Timeout waiting for an ARP reply in milliseconds.
2341 Timeout in milliseconds used in NFS protocol.
2342 If you encounter "ERROR: Cannot umount" in nfs command,
2343 try longer timeout such as
2344 #define CONFIG_NFS_TIMEOUT 10000UL
2346 - Command Interpreter:
2347 CONFIG_AUTO_COMPLETE
2349 Enable auto completion of commands using TAB.
2351 Note that this feature has NOT been implemented yet
2352 for the "hush" shell.
2355 CONFIG_SYS_HUSH_PARSER
2357 Define this variable to enable the "hush" shell (from
2358 Busybox) as command line interpreter, thus enabling
2359 powerful command line syntax like
2360 if...then...else...fi conditionals or `&&' and '||'
2361 constructs ("shell scripts").
2363 If undefined, you get the old, much simpler behaviour
2364 with a somewhat smaller memory footprint.
2367 CONFIG_SYS_PROMPT_HUSH_PS2
2369 This defines the secondary prompt string, which is
2370 printed when the command interpreter needs more input
2371 to complete a command. Usually "> ".
2375 In the current implementation, the local variables
2376 space and global environment variables space are
2377 separated. Local variables are those you define by
2378 simply typing `name=value'. To access a local
2379 variable later on, you have write `$name' or
2380 `${name}'; to execute the contents of a variable
2381 directly type `$name' at the command prompt.
2383 Global environment variables are those you use
2384 setenv/printenv to work with. To run a command stored
2385 in such a variable, you need to use the run command,
2386 and you must not use the '$' sign to access them.
2388 To store commands and special characters in a
2389 variable, please use double quotation marks
2390 surrounding the whole text of the variable, instead
2391 of the backslashes before semicolons and special
2394 - Commandline Editing and History:
2395 CONFIG_CMDLINE_EDITING
2397 Enable editing and History functions for interactive
2398 commandline input operations
2400 - Default Environment:
2401 CONFIG_EXTRA_ENV_SETTINGS
2403 Define this to contain any number of null terminated
2404 strings (variable = value pairs) that will be part of
2405 the default environment compiled into the boot image.
2407 For example, place something like this in your
2408 board's config file:
2410 #define CONFIG_EXTRA_ENV_SETTINGS \
2414 Warning: This method is based on knowledge about the
2415 internal format how the environment is stored by the
2416 U-Boot code. This is NOT an official, exported
2417 interface! Although it is unlikely that this format
2418 will change soon, there is no guarantee either.
2419 You better know what you are doing here.
2421 Note: overly (ab)use of the default environment is
2422 discouraged. Make sure to check other ways to preset
2423 the environment like the "source" command or the
2426 CONFIG_ENV_VARS_UBOOT_CONFIG
2428 Define this in order to add variables describing the
2429 U-Boot build configuration to the default environment.
2430 These will be named arch, cpu, board, vendor, and soc.
2432 Enabling this option will cause the following to be defined:
2440 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2442 Define this in order to add variables describing certain
2443 run-time determined information about the hardware to the
2444 environment. These will be named board_name, board_rev.
2446 CONFIG_DELAY_ENVIRONMENT
2448 Normally the environment is loaded when the board is
2449 intialised so that it is available to U-Boot. This inhibits
2450 that so that the environment is not available until
2451 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2452 this is instead controlled by the value of
2453 /config/load-environment.
2455 - DataFlash Support:
2456 CONFIG_HAS_DATAFLASH
2458 Defining this option enables DataFlash features and
2459 allows to read/write in Dataflash via the standard
2462 - Serial Flash support
2465 Defining this option enables SPI flash commands
2466 'sf probe/read/write/erase/update'.
2468 Usage requires an initial 'probe' to define the serial
2469 flash parameters, followed by read/write/erase/update
2472 The following defaults may be provided by the platform
2473 to handle the common case when only a single serial
2474 flash is present on the system.
2476 CONFIG_SF_DEFAULT_BUS Bus identifier
2477 CONFIG_SF_DEFAULT_CS Chip-select
2478 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2479 CONFIG_SF_DEFAULT_SPEED in Hz
2483 Define this option to include a destructive SPI flash
2486 - SystemACE Support:
2489 Adding this option adds support for Xilinx SystemACE
2490 chips attached via some sort of local bus. The address
2491 of the chip must also be defined in the
2492 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2494 #define CONFIG_SYSTEMACE
2495 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2497 When SystemACE support is added, the "ace" device type
2498 becomes available to the fat commands, i.e. fatls.
2500 - TFTP Fixed UDP Port:
2503 If this is defined, the environment variable tftpsrcp
2504 is used to supply the TFTP UDP source port value.
2505 If tftpsrcp isn't defined, the normal pseudo-random port
2506 number generator is used.
2508 Also, the environment variable tftpdstp is used to supply
2509 the TFTP UDP destination port value. If tftpdstp isn't
2510 defined, the normal port 69 is used.
2512 The purpose for tftpsrcp is to allow a TFTP server to
2513 blindly start the TFTP transfer using the pre-configured
2514 target IP address and UDP port. This has the effect of
2515 "punching through" the (Windows XP) firewall, allowing
2516 the remainder of the TFTP transfer to proceed normally.
2517 A better solution is to properly configure the firewall,
2518 but sometimes that is not allowed.
2523 This enables a generic 'hash' command which can produce
2524 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2528 Enable the hash verify command (hash -v). This adds to code
2531 CONFIG_SHA1 - support SHA1 hashing
2532 CONFIG_SHA256 - support SHA256 hashing
2534 Note: There is also a sha1sum command, which should perhaps
2535 be deprecated in favour of 'hash sha1'.
2537 - Show boot progress:
2538 CONFIG_SHOW_BOOT_PROGRESS
2540 Defining this option allows to add some board-
2541 specific code (calling a user-provided function
2542 "show_boot_progress(int)") that enables you to show
2543 the system's boot progress on some display (for
2544 example, some LED's) on your board. At the moment,
2545 the following checkpoints are implemented:
2547 - Detailed boot stage timing
2549 Define this option to get detailed timing of each stage
2550 of the boot process.
2552 CONFIG_BOOTSTAGE_USER_COUNT
2553 This is the number of available user bootstage records.
2554 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2555 a new ID will be allocated from this stash. If you exceed
2556 the limit, recording will stop.
2558 CONFIG_BOOTSTAGE_REPORT
2559 Define this to print a report before boot, similar to this:
2561 Timer summary in microseconds:
2564 3,575,678 3,575,678 board_init_f start
2565 3,575,695 17 arch_cpu_init A9
2566 3,575,777 82 arch_cpu_init done
2567 3,659,598 83,821 board_init_r start
2568 3,910,375 250,777 main_loop
2569 29,916,167 26,005,792 bootm_start
2570 30,361,327 445,160 start_kernel
2572 CONFIG_CMD_BOOTSTAGE
2573 Add a 'bootstage' command which supports printing a report
2574 and un/stashing of bootstage data.
2576 CONFIG_BOOTSTAGE_FDT
2577 Stash the bootstage information in the FDT. A root 'bootstage'
2578 node is created with each bootstage id as a child. Each child
2579 has a 'name' property and either 'mark' containing the
2580 mark time in microsecond, or 'accum' containing the
2581 accumulated time for that bootstage id in microseconds.
2586 name = "board_init_f";
2595 Code in the Linux kernel can find this in /proc/devicetree.
2597 Legacy uImage format:
2600 1 common/cmd_bootm.c before attempting to boot an image
2601 -1 common/cmd_bootm.c Image header has bad magic number
2602 2 common/cmd_bootm.c Image header has correct magic number
2603 -2 common/cmd_bootm.c Image header has bad checksum
2604 3 common/cmd_bootm.c Image header has correct checksum
2605 -3 common/cmd_bootm.c Image data has bad checksum
2606 4 common/cmd_bootm.c Image data has correct checksum
2607 -4 common/cmd_bootm.c Image is for unsupported architecture
2608 5 common/cmd_bootm.c Architecture check OK
2609 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2610 6 common/cmd_bootm.c Image Type check OK
2611 -6 common/cmd_bootm.c gunzip uncompression error
2612 -7 common/cmd_bootm.c Unimplemented compression type
2613 7 common/cmd_bootm.c Uncompression OK
2614 8 common/cmd_bootm.c No uncompress/copy overwrite error
2615 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2617 9 common/image.c Start initial ramdisk verification
2618 -10 common/image.c Ramdisk header has bad magic number
2619 -11 common/image.c Ramdisk header has bad checksum
2620 10 common/image.c Ramdisk header is OK
2621 -12 common/image.c Ramdisk data has bad checksum
2622 11 common/image.c Ramdisk data has correct checksum
2623 12 common/image.c Ramdisk verification complete, start loading
2624 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2625 13 common/image.c Start multifile image verification
2626 14 common/image.c No initial ramdisk, no multifile, continue.
2628 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2630 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2631 -31 post/post.c POST test failed, detected by post_output_backlog()
2632 -32 post/post.c POST test failed, detected by post_run_single()
2634 34 common/cmd_doc.c before loading a Image from a DOC device
2635 -35 common/cmd_doc.c Bad usage of "doc" command
2636 35 common/cmd_doc.c correct usage of "doc" command
2637 -36 common/cmd_doc.c No boot device
2638 36 common/cmd_doc.c correct boot device
2639 -37 common/cmd_doc.c Unknown Chip ID on boot device
2640 37 common/cmd_doc.c correct chip ID found, device available
2641 -38 common/cmd_doc.c Read Error on boot device
2642 38 common/cmd_doc.c reading Image header from DOC device OK
2643 -39 common/cmd_doc.c Image header has bad magic number
2644 39 common/cmd_doc.c Image header has correct magic number
2645 -40 common/cmd_doc.c Error reading Image from DOC device
2646 40 common/cmd_doc.c Image header has correct magic number
2647 41 common/cmd_ide.c before loading a Image from a IDE device
2648 -42 common/cmd_ide.c Bad usage of "ide" command
2649 42 common/cmd_ide.c correct usage of "ide" command
2650 -43 common/cmd_ide.c No boot device
2651 43 common/cmd_ide.c boot device found
2652 -44 common/cmd_ide.c Device not available
2653 44 common/cmd_ide.c Device available
2654 -45 common/cmd_ide.c wrong partition selected
2655 45 common/cmd_ide.c partition selected
2656 -46 common/cmd_ide.c Unknown partition table
2657 46 common/cmd_ide.c valid partition table found
2658 -47 common/cmd_ide.c Invalid partition type
2659 47 common/cmd_ide.c correct partition type
2660 -48 common/cmd_ide.c Error reading Image Header on boot device
2661 48 common/cmd_ide.c reading Image Header from IDE device OK
2662 -49 common/cmd_ide.c Image header has bad magic number
2663 49 common/cmd_ide.c Image header has correct magic number
2664 -50 common/cmd_ide.c Image header has bad checksum
2665 50 common/cmd_ide.c Image header has correct checksum
2666 -51 common/cmd_ide.c Error reading Image from IDE device
2667 51 common/cmd_ide.c reading Image from IDE device OK
2668 52 common/cmd_nand.c before loading a Image from a NAND device
2669 -53 common/cmd_nand.c Bad usage of "nand" command
2670 53 common/cmd_nand.c correct usage of "nand" command
2671 -54 common/cmd_nand.c No boot device
2672 54 common/cmd_nand.c boot device found
2673 -55 common/cmd_nand.c Unknown Chip ID on boot device
2674 55 common/cmd_nand.c correct chip ID found, device available
2675 -56 common/cmd_nand.c Error reading Image Header on boot device
2676 56 common/cmd_nand.c reading Image Header from NAND device OK
2677 -57 common/cmd_nand.c Image header has bad magic number
2678 57 common/cmd_nand.c Image header has correct magic number
2679 -58 common/cmd_nand.c Error reading Image from NAND device
2680 58 common/cmd_nand.c reading Image from NAND device OK
2682 -60 common/env_common.c Environment has a bad CRC, using default
2684 64 net/eth.c starting with Ethernet configuration.
2685 -64 net/eth.c no Ethernet found.
2686 65 net/eth.c Ethernet found.
2688 -80 common/cmd_net.c usage wrong
2689 80 common/cmd_net.c before calling NetLoop()
2690 -81 common/cmd_net.c some error in NetLoop() occurred
2691 81 common/cmd_net.c NetLoop() back without error
2692 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2693 82 common/cmd_net.c trying automatic boot
2694 83 common/cmd_net.c running "source" command
2695 -83 common/cmd_net.c some error in automatic boot or "source" command
2696 84 common/cmd_net.c end without errors
2701 100 common/cmd_bootm.c Kernel FIT Image has correct format
2702 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2703 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2704 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2705 102 common/cmd_bootm.c Kernel unit name specified
2706 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2707 103 common/cmd_bootm.c Found configuration node
2708 104 common/cmd_bootm.c Got kernel subimage node offset
2709 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2710 105 common/cmd_bootm.c Kernel subimage hash verification OK
2711 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2712 106 common/cmd_bootm.c Architecture check OK
2713 -106 common/cmd_bootm.c Kernel subimage has wrong type
2714 107 common/cmd_bootm.c Kernel subimage type OK
2715 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2716 108 common/cmd_bootm.c Got kernel subimage data/size
2717 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2718 -109 common/cmd_bootm.c Can't get kernel subimage type
2719 -110 common/cmd_bootm.c Can't get kernel subimage comp
2720 -111 common/cmd_bootm.c Can't get kernel subimage os
2721 -112 common/cmd_bootm.c Can't get kernel subimage load address
2722 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2724 120 common/image.c Start initial ramdisk verification
2725 -120 common/image.c Ramdisk FIT image has incorrect format
2726 121 common/image.c Ramdisk FIT image has correct format
2727 122 common/image.c No ramdisk subimage unit name, using configuration
2728 -122 common/image.c Can't get configuration for ramdisk subimage
2729 123 common/image.c Ramdisk unit name specified
2730 -124 common/image.c Can't get ramdisk subimage node offset
2731 125 common/image.c Got ramdisk subimage node offset
2732 -125 common/image.c Ramdisk subimage hash verification failed
2733 126 common/image.c Ramdisk subimage hash verification OK
2734 -126 common/image.c Ramdisk subimage for unsupported architecture
2735 127 common/image.c Architecture check OK
2736 -127 common/image.c Can't get ramdisk subimage data/size
2737 128 common/image.c Got ramdisk subimage data/size
2738 129 common/image.c Can't get ramdisk load address
2739 -129 common/image.c Got ramdisk load address
2741 -130 common/cmd_doc.c Incorrect FIT image format
2742 131 common/cmd_doc.c FIT image format OK
2744 -140 common/cmd_ide.c Incorrect FIT image format
2745 141 common/cmd_ide.c FIT image format OK
2747 -150 common/cmd_nand.c Incorrect FIT image format
2748 151 common/cmd_nand.c FIT image format OK
2750 - FIT image support:
2752 Enable support for the FIT uImage format.
2754 CONFIG_FIT_BEST_MATCH
2755 When no configuration is explicitly selected, default to the
2756 one whose fdt's compatibility field best matches that of
2757 U-Boot itself. A match is considered "best" if it matches the
2758 most specific compatibility entry of U-Boot's fdt's root node.
2759 The order of entries in the configuration's fdt is ignored.
2761 - Standalone program support:
2762 CONFIG_STANDALONE_LOAD_ADDR
2764 This option defines a board specific value for the
2765 address where standalone program gets loaded, thus
2766 overwriting the architecture dependent default
2769 - Frame Buffer Address:
2772 Define CONFIG_FB_ADDR if you want to use specific
2773 address for frame buffer. This is typically the case
2774 when using a graphics controller has separate video
2775 memory. U-Boot will then place the frame buffer at
2776 the given address instead of dynamically reserving it
2777 in system RAM by calling lcd_setmem(), which grabs
2778 the memory for the frame buffer depending on the
2779 configured panel size.
2781 Please see board_init_f function.
2783 - Automatic software updates via TFTP server
2785 CONFIG_UPDATE_TFTP_CNT_MAX
2786 CONFIG_UPDATE_TFTP_MSEC_MAX
2788 These options enable and control the auto-update feature;
2789 for a more detailed description refer to doc/README.update.
2791 - MTD Support (mtdparts command, UBI support)
2794 Adds the MTD device infrastructure from the Linux kernel.
2795 Needed for mtdparts command support.
2797 CONFIG_MTD_PARTITIONS
2799 Adds the MTD partitioning infrastructure from the Linux
2800 kernel. Needed for UBI support.
2805 Adds commands for interacting with MTD partitions formatted
2806 with the UBI flash translation layer
2808 Requires also defining CONFIG_RBTREE
2810 CONFIG_UBI_SILENCE_MSG
2812 Make the verbose messages from UBI stop printing. This leaves
2813 warnings and errors enabled.
2818 Adds commands for interacting with UBI volumes formatted as
2819 UBIFS. UBIFS is read-only in u-boot.
2821 Requires UBI support as well as CONFIG_LZO
2823 CONFIG_UBIFS_SILENCE_MSG
2825 Make the verbose messages from UBIFS stop printing. This leaves
2826 warnings and errors enabled.
2830 Enable building of SPL globally.
2833 LDSCRIPT for linking the SPL binary.
2835 CONFIG_SPL_MAX_FOOTPRINT
2836 Maximum size in memory allocated to the SPL, BSS included.
2837 When defined, the linker checks that the actual memory
2838 used by SPL from _start to __bss_end does not exceed it.
2839 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2840 must not be both defined at the same time.
2843 Maximum size of the SPL image (text, data, rodata, and
2844 linker lists sections), BSS excluded.
2845 When defined, the linker checks that the actual size does
2848 CONFIG_SPL_TEXT_BASE
2849 TEXT_BASE for linking the SPL binary.
2851 CONFIG_SPL_RELOC_TEXT_BASE
2852 Address to relocate to. If unspecified, this is equal to
2853 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2855 CONFIG_SPL_BSS_START_ADDR
2856 Link address for the BSS within the SPL binary.
2858 CONFIG_SPL_BSS_MAX_SIZE
2859 Maximum size in memory allocated to the SPL BSS.
2860 When defined, the linker checks that the actual memory used
2861 by SPL from __bss_start to __bss_end does not exceed it.
2862 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2863 must not be both defined at the same time.
2866 Adress of the start of the stack SPL will use
2868 CONFIG_SPL_RELOC_STACK
2869 Adress of the start of the stack SPL will use after
2870 relocation. If unspecified, this is equal to
2873 CONFIG_SYS_SPL_MALLOC_START
2874 Starting address of the malloc pool used in SPL.
2876 CONFIG_SYS_SPL_MALLOC_SIZE
2877 The size of the malloc pool used in SPL.
2879 CONFIG_SPL_FRAMEWORK
2880 Enable the SPL framework under common/. This framework
2881 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2882 NAND loading of the Linux Kernel.
2884 CONFIG_SPL_DISPLAY_PRINT
2885 For ARM, enable an optional function to print more information
2886 about the running system.
2888 CONFIG_SPL_INIT_MINIMAL
2889 Arch init code should be built for a very small image
2891 CONFIG_SPL_LIBCOMMON_SUPPORT
2892 Support for common/libcommon.o in SPL binary
2894 CONFIG_SPL_LIBDISK_SUPPORT
2895 Support for disk/libdisk.o in SPL binary
2897 CONFIG_SPL_I2C_SUPPORT
2898 Support for drivers/i2c/libi2c.o in SPL binary
2900 CONFIG_SPL_GPIO_SUPPORT
2901 Support for drivers/gpio/libgpio.o in SPL binary
2903 CONFIG_SPL_MMC_SUPPORT
2904 Support for drivers/mmc/libmmc.o in SPL binary
2906 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2907 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2908 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2909 Address, size and partition on the MMC to load U-Boot from
2910 when the MMC is being used in raw mode.
2912 CONFIG_SPL_FAT_SUPPORT
2913 Support for fs/fat/libfat.o in SPL binary
2915 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2916 Filename to read to load U-Boot when reading from FAT
2918 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2919 Set this for NAND SPL on PPC mpc83xx targets, so that
2920 start.S waits for the rest of the SPL to load before
2921 continuing (the hardware starts execution after just
2922 loading the first page rather than the full 4K).
2924 CONFIG_SPL_NAND_BASE
2925 Include nand_base.c in the SPL. Requires
2926 CONFIG_SPL_NAND_DRIVERS.
2928 CONFIG_SPL_NAND_DRIVERS
2929 SPL uses normal NAND drivers, not minimal drivers.
2932 Include standard software ECC in the SPL
2934 CONFIG_SPL_NAND_SIMPLE
2935 Support for NAND boot using simple NAND drivers that
2936 expose the cmd_ctrl() interface.
2938 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2939 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2940 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2941 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2942 CONFIG_SYS_NAND_ECCBYTES
2943 Defines the size and behavior of the NAND that SPL uses
2946 CONFIG_SYS_NAND_U_BOOT_OFFS
2947 Location in NAND to read U-Boot from
2949 CONFIG_SYS_NAND_U_BOOT_DST
2950 Location in memory to load U-Boot to
2952 CONFIG_SYS_NAND_U_BOOT_SIZE
2953 Size of image to load
2955 CONFIG_SYS_NAND_U_BOOT_START
2956 Entry point in loaded image to jump to
2958 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2959 Define this if you need to first read the OOB and then the
2960 data. This is used for example on davinci plattforms.
2962 CONFIG_SPL_OMAP3_ID_NAND
2963 Support for an OMAP3-specific set of functions to return the
2964 ID and MFR of the first attached NAND chip, if present.
2966 CONFIG_SPL_SERIAL_SUPPORT
2967 Support for drivers/serial/libserial.o in SPL binary
2969 CONFIG_SPL_SPI_FLASH_SUPPORT
2970 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2972 CONFIG_SPL_SPI_SUPPORT
2973 Support for drivers/spi/libspi.o in SPL binary
2975 CONFIG_SPL_RAM_DEVICE
2976 Support for running image already present in ram, in SPL binary
2978 CONFIG_SPL_LIBGENERIC_SUPPORT
2979 Support for lib/libgeneric.o in SPL binary
2982 Image offset to which the SPL should be padded before appending
2983 the SPL payload. By default, this is defined as
2984 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2985 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2986 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
2989 Final target image containing SPL and payload. Some SPLs
2990 use an arch-specific makefile fragment instead, for
2991 example if more than one image needs to be produced.
2996 [so far only for SMDK2400 boards]
2998 - Modem support enable:
2999 CONFIG_MODEM_SUPPORT
3001 - RTS/CTS Flow control enable:
3004 - Modem debug support:
3005 CONFIG_MODEM_SUPPORT_DEBUG
3007 Enables debugging stuff (char screen[1024], dbg())
3008 for modem support. Useful only with BDI2000.
3010 - Interrupt support (PPC):
3012 There are common interrupt_init() and timer_interrupt()
3013 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3014 for CPU specific initialization. interrupt_init_cpu()
3015 should set decrementer_count to appropriate value. If
3016 CPU resets decrementer automatically after interrupt
3017 (ppc4xx) it should set decrementer_count to zero.
3018 timer_interrupt() calls timer_interrupt_cpu() for CPU
3019 specific handling. If board has watchdog / status_led
3020 / other_activity_monitor it works automatically from
3021 general timer_interrupt().
3025 In the target system modem support is enabled when a
3026 specific key (key combination) is pressed during
3027 power-on. Otherwise U-Boot will boot normally
3028 (autoboot). The key_pressed() function is called from
3029 board_init(). Currently key_pressed() is a dummy
3030 function, returning 1 and thus enabling modem
3033 If there are no modem init strings in the
3034 environment, U-Boot proceed to autoboot; the
3035 previous output (banner, info printfs) will be
3038 See also: doc/README.Modem
3040 Board initialization settings:
3041 ------------------------------
3043 During Initialization u-boot calls a number of board specific functions
3044 to allow the preparation of board specific prerequisites, e.g. pin setup
3045 before drivers are initialized. To enable these callbacks the
3046 following configuration macros have to be defined. Currently this is
3047 architecture specific, so please check arch/your_architecture/lib/board.c
3048 typically in board_init_f() and board_init_r().
3050 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3051 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3052 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3053 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3055 Configuration Settings:
3056 -----------------------
3058 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3059 undefine this when you're short of memory.
3061 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3062 width of the commands listed in the 'help' command output.
3064 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3065 prompt for user input.
3067 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3069 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3071 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3073 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3074 the application (usually a Linux kernel) when it is
3077 - CONFIG_SYS_BAUDRATE_TABLE:
3078 List of legal baudrate settings for this board.
3080 - CONFIG_SYS_CONSOLE_INFO_QUIET
3081 Suppress display of console information at boot.
3083 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3084 If the board specific function
3085 extern int overwrite_console (void);
3086 returns 1, the stdin, stderr and stdout are switched to the
3087 serial port, else the settings in the environment are used.
3089 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3090 Enable the call to overwrite_console().
3092 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3093 Enable overwrite of previous console environment settings.
3095 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3096 Begin and End addresses of the area used by the
3099 - CONFIG_SYS_ALT_MEMTEST:
3100 Enable an alternate, more extensive memory test.
3102 - CONFIG_SYS_MEMTEST_SCRATCH:
3103 Scratch address used by the alternate memory test
3104 You only need to set this if address zero isn't writeable
3106 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3107 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3108 this specified memory area will get subtracted from the top
3109 (end) of RAM and won't get "touched" at all by U-Boot. By
3110 fixing up gd->ram_size the Linux kernel should gets passed
3111 the now "corrected" memory size and won't touch it either.
3112 This should work for arch/ppc and arch/powerpc. Only Linux
3113 board ports in arch/powerpc with bootwrapper support that
3114 recalculate the memory size from the SDRAM controller setup
3115 will have to get fixed in Linux additionally.
3117 This option can be used as a workaround for the 440EPx/GRx
3118 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3121 WARNING: Please make sure that this value is a multiple of
3122 the Linux page size (normally 4k). If this is not the case,
3123 then the end address of the Linux memory will be located at a
3124 non page size aligned address and this could cause major
3127 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3128 Enable temporary baudrate change while serial download
3130 - CONFIG_SYS_SDRAM_BASE:
3131 Physical start address of SDRAM. _Must_ be 0 here.
3133 - CONFIG_SYS_MBIO_BASE:
3134 Physical start address of Motherboard I/O (if using a
3137 - CONFIG_SYS_FLASH_BASE:
3138 Physical start address of Flash memory.
3140 - CONFIG_SYS_MONITOR_BASE:
3141 Physical start address of boot monitor code (set by
3142 make config files to be same as the text base address
3143 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3144 CONFIG_SYS_FLASH_BASE when booting from flash.
3146 - CONFIG_SYS_MONITOR_LEN:
3147 Size of memory reserved for monitor code, used to
3148 determine _at_compile_time_ (!) if the environment is
3149 embedded within the U-Boot image, or in a separate
3152 - CONFIG_SYS_MALLOC_LEN:
3153 Size of DRAM reserved for malloc() use.
3155 - CONFIG_SYS_BOOTM_LEN:
3156 Normally compressed uImages are limited to an
3157 uncompressed size of 8 MBytes. If this is not enough,
3158 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3159 to adjust this setting to your needs.
3161 - CONFIG_SYS_BOOTMAPSZ:
3162 Maximum size of memory mapped by the startup code of
3163 the Linux kernel; all data that must be processed by
3164 the Linux kernel (bd_info, boot arguments, FDT blob if
3165 used) must be put below this limit, unless "bootm_low"
3166 enviroment variable is defined and non-zero. In such case
3167 all data for the Linux kernel must be between "bootm_low"
3168 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3169 variable "bootm_mapsize" will override the value of
3170 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3171 then the value in "bootm_size" will be used instead.
3173 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3174 Enable initrd_high functionality. If defined then the
3175 initrd_high feature is enabled and the bootm ramdisk subcommand
3178 - CONFIG_SYS_BOOT_GET_CMDLINE:
3179 Enables allocating and saving kernel cmdline in space between
3180 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3182 - CONFIG_SYS_BOOT_GET_KBD:
3183 Enables allocating and saving a kernel copy of the bd_info in
3184 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3186 - CONFIG_SYS_MAX_FLASH_BANKS:
3187 Max number of Flash memory banks
3189 - CONFIG_SYS_MAX_FLASH_SECT:
3190 Max number of sectors on a Flash chip
3192 - CONFIG_SYS_FLASH_ERASE_TOUT:
3193 Timeout for Flash erase operations (in ms)
3195 - CONFIG_SYS_FLASH_WRITE_TOUT:
3196 Timeout for Flash write operations (in ms)
3198 - CONFIG_SYS_FLASH_LOCK_TOUT
3199 Timeout for Flash set sector lock bit operation (in ms)
3201 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3202 Timeout for Flash clear lock bits operation (in ms)
3204 - CONFIG_SYS_FLASH_PROTECTION
3205 If defined, hardware flash sectors protection is used
3206 instead of U-Boot software protection.
3208 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3210 Enable TFTP transfers directly to flash memory;
3211 without this option such a download has to be
3212 performed in two steps: (1) download to RAM, and (2)
3213 copy from RAM to flash.
3215 The two-step approach is usually more reliable, since
3216 you can check if the download worked before you erase
3217 the flash, but in some situations (when system RAM is
3218 too limited to allow for a temporary copy of the
3219 downloaded image) this option may be very useful.
3221 - CONFIG_SYS_FLASH_CFI:
3222 Define if the flash driver uses extra elements in the
3223 common flash structure for storing flash geometry.
3225 - CONFIG_FLASH_CFI_DRIVER
3226 This option also enables the building of the cfi_flash driver
3227 in the drivers directory
3229 - CONFIG_FLASH_CFI_MTD
3230 This option enables the building of the cfi_mtd driver
3231 in the drivers directory. The driver exports CFI flash
3234 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3235 Use buffered writes to flash.
3237 - CONFIG_FLASH_SPANSION_S29WS_N
3238 s29ws-n MirrorBit flash has non-standard addresses for buffered
3241 - CONFIG_SYS_FLASH_QUIET_TEST
3242 If this option is defined, the common CFI flash doesn't
3243 print it's warning upon not recognized FLASH banks. This
3244 is useful, if some of the configured banks are only
3245 optionally available.
3247 - CONFIG_FLASH_SHOW_PROGRESS
3248 If defined (must be an integer), print out countdown
3249 digits and dots. Recommended value: 45 (9..1) for 80
3250 column displays, 15 (3..1) for 40 column displays.
3252 - CONFIG_SYS_RX_ETH_BUFFER:
3253 Defines the number of Ethernet receive buffers. On some
3254 Ethernet controllers it is recommended to set this value
3255 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3256 buffers can be full shortly after enabling the interface
3257 on high Ethernet traffic.
3258 Defaults to 4 if not defined.
3260 - CONFIG_ENV_MAX_ENTRIES
3262 Maximum number of entries in the hash table that is used
3263 internally to store the environment settings. The default
3264 setting is supposed to be generous and should work in most
3265 cases. This setting can be used to tune behaviour; see
3266 lib/hashtable.c for details.
3268 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3269 - CONFIG_ENV_FLAGS_LIST_STATIC
3270 Enable validation of the values given to enviroment variables when
3271 calling env set. Variables can be restricted to only decimal,
3272 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3273 the variables can also be restricted to IP address or MAC address.
3275 The format of the list is:
3276 type_attribute = [s|d|x|b|i|m]
3277 access_atribute = [a|r|o|c]
3278 attributes = type_attribute[access_atribute]
3279 entry = variable_name[:attributes]
3282 The type attributes are:
3283 s - String (default)
3286 b - Boolean ([1yYtT|0nNfF])
3290 The access attributes are:
3296 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3297 Define this to a list (string) to define the ".flags"
3298 envirnoment variable in the default or embedded environment.
3300 - CONFIG_ENV_FLAGS_LIST_STATIC
3301 Define this to a list (string) to define validation that
3302 should be done if an entry is not found in the ".flags"
3303 environment variable. To override a setting in the static
3304 list, simply add an entry for the same variable name to the
3307 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3308 If defined, don't allow the -f switch to env set override variable
3311 - CONFIG_SYS_GENERIC_BOARD
3312 This selects the architecture-generic board system instead of the
3313 architecture-specific board files. It is intended to move boards
3314 to this new framework over time. Defining this will disable the
3315 arch/foo/lib/board.c file and use common/board_f.c and
3316 common/board_r.c instead. To use this option your architecture
3317 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3318 its config.mk file). If you find problems enabling this option on
3319 your board please report the problem and send patches!
3321 - CONFIG_SYS_SYM_OFFSETS
3322 This is set by architectures that use offsets for link symbols
3323 instead of absolute values. So bss_start is obtained using an
3324 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3325 directly. You should not need to touch this setting.
3328 The following definitions that deal with the placement and management
3329 of environment data (variable area); in general, we support the
3330 following configurations:
3332 - CONFIG_BUILD_ENVCRC:
3334 Builds up envcrc with the target environment so that external utils
3335 may easily extract it and embed it in final U-Boot images.
3337 - CONFIG_ENV_IS_IN_FLASH:
3339 Define this if the environment is in flash memory.
3341 a) The environment occupies one whole flash sector, which is
3342 "embedded" in the text segment with the U-Boot code. This
3343 happens usually with "bottom boot sector" or "top boot
3344 sector" type flash chips, which have several smaller
3345 sectors at the start or the end. For instance, such a
3346 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3347 such a case you would place the environment in one of the
3348 4 kB sectors - with U-Boot code before and after it. With
3349 "top boot sector" type flash chips, you would put the
3350 environment in one of the last sectors, leaving a gap
3351 between U-Boot and the environment.
3353 - CONFIG_ENV_OFFSET:
3355 Offset of environment data (variable area) to the
3356 beginning of flash memory; for instance, with bottom boot
3357 type flash chips the second sector can be used: the offset
3358 for this sector is given here.
3360 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3364 This is just another way to specify the start address of
3365 the flash sector containing the environment (instead of
3368 - CONFIG_ENV_SECT_SIZE:
3370 Size of the sector containing the environment.
3373 b) Sometimes flash chips have few, equal sized, BIG sectors.
3374 In such a case you don't want to spend a whole sector for
3379 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3380 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3381 of this flash sector for the environment. This saves
3382 memory for the RAM copy of the environment.
3384 It may also save flash memory if you decide to use this
3385 when your environment is "embedded" within U-Boot code,
3386 since then the remainder of the flash sector could be used
3387 for U-Boot code. It should be pointed out that this is
3388 STRONGLY DISCOURAGED from a robustness point of view:
3389 updating the environment in flash makes it always
3390 necessary to erase the WHOLE sector. If something goes
3391 wrong before the contents has been restored from a copy in
3392 RAM, your target system will be dead.
3394 - CONFIG_ENV_ADDR_REDUND
3395 CONFIG_ENV_SIZE_REDUND
3397 These settings describe a second storage area used to hold
3398 a redundant copy of the environment data, so that there is
3399 a valid backup copy in case there is a power failure during
3400 a "saveenv" operation.
3402 BE CAREFUL! Any changes to the flash layout, and some changes to the
3403 source code will make it necessary to adapt <board>/u-boot.lds*
3407 - CONFIG_ENV_IS_IN_NVRAM:
3409 Define this if you have some non-volatile memory device
3410 (NVRAM, battery buffered SRAM) which you want to use for the
3416 These two #defines are used to determine the memory area you
3417 want to use for environment. It is assumed that this memory
3418 can just be read and written to, without any special
3421 BE CAREFUL! The first access to the environment happens quite early
3422 in U-Boot initalization (when we try to get the setting of for the
3423 console baudrate). You *MUST* have mapped your NVRAM area then, or
3426 Please note that even with NVRAM we still use a copy of the
3427 environment in RAM: we could work on NVRAM directly, but we want to
3428 keep settings there always unmodified except somebody uses "saveenv"
3429 to save the current settings.
3432 - CONFIG_ENV_IS_IN_EEPROM:
3434 Use this if you have an EEPROM or similar serial access
3435 device and a driver for it.
3437 - CONFIG_ENV_OFFSET:
3440 These two #defines specify the offset and size of the
3441 environment area within the total memory of your EEPROM.
3443 - CONFIG_SYS_I2C_EEPROM_ADDR:
3444 If defined, specified the chip address of the EEPROM device.
3445 The default address is zero.
3447 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3448 If defined, the number of bits used to address bytes in a
3449 single page in the EEPROM device. A 64 byte page, for example
3450 would require six bits.
3452 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3453 If defined, the number of milliseconds to delay between
3454 page writes. The default is zero milliseconds.
3456 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3457 The length in bytes of the EEPROM memory array address. Note
3458 that this is NOT the chip address length!
3460 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3461 EEPROM chips that implement "address overflow" are ones
3462 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3463 address and the extra bits end up in the "chip address" bit
3464 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3467 Note that we consider the length of the address field to
3468 still be one byte because the extra address bits are hidden
3469 in the chip address.
3471 - CONFIG_SYS_EEPROM_SIZE:
3472 The size in bytes of the EEPROM device.
3474 - CONFIG_ENV_EEPROM_IS_ON_I2C
3475 define this, if you have I2C and SPI activated, and your
3476 EEPROM, which holds the environment, is on the I2C bus.
3478 - CONFIG_I2C_ENV_EEPROM_BUS
3479 if you have an Environment on an EEPROM reached over
3480 I2C muxes, you can define here, how to reach this
3481 EEPROM. For example:
3483 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3485 EEPROM which holds the environment, is reached over
3486 a pca9547 i2c mux with address 0x70, channel 3.
3488 - CONFIG_ENV_IS_IN_DATAFLASH:
3490 Define this if you have a DataFlash memory device which you
3491 want to use for the environment.
3493 - CONFIG_ENV_OFFSET:
3497 These three #defines specify the offset and size of the
3498 environment area within the total memory of your DataFlash placed
3499 at the specified address.
3501 - CONFIG_ENV_IS_IN_REMOTE:
3503 Define this if you have a remote memory space which you
3504 want to use for the local device's environment.
3509 These two #defines specify the address and size of the
3510 environment area within the remote memory space. The
3511 local device can get the environment from remote memory
3512 space by SRIO or PCIE links.
3514 BE CAREFUL! For some special cases, the local device can not use
3515 "saveenv" command. For example, the local device will get the
3516 environment stored in a remote NOR flash by SRIO or PCIE link,
3517 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3519 - CONFIG_ENV_IS_IN_NAND:
3521 Define this if you have a NAND device which you want to use
3522 for the environment.
3524 - CONFIG_ENV_OFFSET:
3527 These two #defines specify the offset and size of the environment
3528 area within the first NAND device. CONFIG_ENV_OFFSET must be
3529 aligned to an erase block boundary.
3531 - CONFIG_ENV_OFFSET_REDUND (optional):
3533 This setting describes a second storage area of CONFIG_ENV_SIZE
3534 size used to hold a redundant copy of the environment data, so
3535 that there is a valid backup copy in case there is a power failure
3536 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3537 aligned to an erase block boundary.
3539 - CONFIG_ENV_RANGE (optional):
3541 Specifies the length of the region in which the environment
3542 can be written. This should be a multiple of the NAND device's
3543 block size. Specifying a range with more erase blocks than
3544 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3545 the range to be avoided.
3547 - CONFIG_ENV_OFFSET_OOB (optional):
3549 Enables support for dynamically retrieving the offset of the
3550 environment from block zero's out-of-band data. The
3551 "nand env.oob" command can be used to record this offset.
3552 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3553 using CONFIG_ENV_OFFSET_OOB.
3555 - CONFIG_NAND_ENV_DST
3557 Defines address in RAM to which the nand_spl code should copy the
3558 environment. If redundant environment is used, it will be copied to
3559 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3561 - CONFIG_ENV_IS_IN_UBI:
3563 Define this if you have an UBI volume that you want to use for the
3564 environment. This has the benefit of wear-leveling the environment
3565 accesses, which is important on NAND.
3567 - CONFIG_ENV_UBI_PART:
3569 Define this to a string that is the mtd partition containing the UBI.
3571 - CONFIG_ENV_UBI_VOLUME:
3573 Define this to the name of the volume that you want to store the
3576 - CONFIG_ENV_UBI_VOLUME_REDUND:
3578 Define this to the name of another volume to store a second copy of
3579 the environment in. This will enable redundant environments in UBI.
3580 It is assumed that both volumes are in the same MTD partition.
3582 - CONFIG_UBI_SILENCE_MSG
3583 - CONFIG_UBIFS_SILENCE_MSG
3585 You will probably want to define these to avoid a really noisy system
3586 when storing the env in UBI.
3588 - CONFIG_SYS_SPI_INIT_OFFSET
3590 Defines offset to the initial SPI buffer area in DPRAM. The
3591 area is used at an early stage (ROM part) if the environment
3592 is configured to reside in the SPI EEPROM: We need a 520 byte
3593 scratch DPRAM area. It is used between the two initialization
3594 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3595 to be a good choice since it makes it far enough from the
3596 start of the data area as well as from the stack pointer.
3598 Please note that the environment is read-only until the monitor
3599 has been relocated to RAM and a RAM copy of the environment has been
3600 created; also, when using EEPROM you will have to use getenv_f()
3601 until then to read environment variables.
3603 The environment is protected by a CRC32 checksum. Before the monitor
3604 is relocated into RAM, as a result of a bad CRC you will be working
3605 with the compiled-in default environment - *silently*!!! [This is
3606 necessary, because the first environment variable we need is the
3607 "baudrate" setting for the console - if we have a bad CRC, we don't
3608 have any device yet where we could complain.]
3610 Note: once the monitor has been relocated, then it will complain if
3611 the default environment is used; a new CRC is computed as soon as you
3612 use the "saveenv" command to store a valid environment.
3614 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3615 Echo the inverted Ethernet link state to the fault LED.
3617 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3618 also needs to be defined.
3620 - CONFIG_SYS_FAULT_MII_ADDR:
3621 MII address of the PHY to check for the Ethernet link state.
3623 - CONFIG_NS16550_MIN_FUNCTIONS:
3624 Define this if you desire to only have use of the NS16550_init
3625 and NS16550_putc functions for the serial driver located at
3626 drivers/serial/ns16550.c. This option is useful for saving
3627 space for already greatly restricted images, including but not
3628 limited to NAND_SPL configurations.
3630 - CONFIG_DISPLAY_BOARDINFO
3631 Display information about the board that U-Boot is running on
3632 when U-Boot starts up. The board function checkboard() is called
3635 - CONFIG_DISPLAY_BOARDINFO_LATE
3636 Similar to the previous option, but display this information
3637 later, once stdio is running and output goes to the LCD, if
3640 Low Level (hardware related) configuration options:
3641 ---------------------------------------------------
3643 - CONFIG_SYS_CACHELINE_SIZE:
3644 Cache Line Size of the CPU.
3646 - CONFIG_SYS_DEFAULT_IMMR:
3647 Default address of the IMMR after system reset.
3649 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3650 and RPXsuper) to be able to adjust the position of
3651 the IMMR register after a reset.
3653 - CONFIG_SYS_CCSRBAR_DEFAULT:
3654 Default (power-on reset) physical address of CCSR on Freescale
3657 - CONFIG_SYS_CCSRBAR:
3658 Virtual address of CCSR. On a 32-bit build, this is typically
3659 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3661 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3662 for cross-platform code that uses that macro instead.
3664 - CONFIG_SYS_CCSRBAR_PHYS:
3665 Physical address of CCSR. CCSR can be relocated to a new
3666 physical address, if desired. In this case, this macro should
3667 be set to that address. Otherwise, it should be set to the
3668 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3669 is typically relocated on 36-bit builds. It is recommended
3670 that this macro be defined via the _HIGH and _LOW macros:
3672 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3673 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3675 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3676 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3677 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3678 used in assembly code, so it must not contain typecasts or
3679 integer size suffixes (e.g. "ULL").
3681 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3682 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3683 used in assembly code, so it must not contain typecasts or
3684 integer size suffixes (e.g. "ULL").
3686 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3687 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3688 forced to a value that ensures that CCSR is not relocated.
3690 - Floppy Disk Support:
3691 CONFIG_SYS_FDC_DRIVE_NUMBER
3693 the default drive number (default value 0)
3695 CONFIG_SYS_ISA_IO_STRIDE
3697 defines the spacing between FDC chipset registers
3700 CONFIG_SYS_ISA_IO_OFFSET
3702 defines the offset of register from address. It
3703 depends on which part of the data bus is connected to
3704 the FDC chipset. (default value 0)
3706 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3707 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3710 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3711 fdc_hw_init() is called at the beginning of the FDC
3712 setup. fdc_hw_init() must be provided by the board
3713 source code. It is used to make hardware dependant
3717 Most IDE controllers were designed to be connected with PCI
3718 interface. Only few of them were designed for AHB interface.
3719 When software is doing ATA command and data transfer to
3720 IDE devices through IDE-AHB controller, some additional
3721 registers accessing to these kind of IDE-AHB controller
3724 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3725 DO NOT CHANGE unless you know exactly what you're
3726 doing! (11-4) [MPC8xx/82xx systems only]
3728 - CONFIG_SYS_INIT_RAM_ADDR:
3730 Start address of memory area that can be used for
3731 initial data and stack; please note that this must be
3732 writable memory that is working WITHOUT special
3733 initialization, i. e. you CANNOT use normal RAM which
3734 will become available only after programming the
3735 memory controller and running certain initialization
3738 U-Boot uses the following memory types:
3739 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3740 - MPC824X: data cache
3741 - PPC4xx: data cache
3743 - CONFIG_SYS_GBL_DATA_OFFSET:
3745 Offset of the initial data structure in the memory
3746 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3747 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3748 data is located at the end of the available space
3749 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3750 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3751 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3752 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3755 On the MPC824X (or other systems that use the data
3756 cache for initial memory) the address chosen for
3757 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3758 point to an otherwise UNUSED address space between
3759 the top of RAM and the start of the PCI space.
3761 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3763 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3765 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3767 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3769 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3771 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3773 - CONFIG_SYS_OR_TIMING_SDRAM:
3776 - CONFIG_SYS_MAMR_PTA:
3777 periodic timer for refresh
3779 - CONFIG_SYS_DER: Debug Event Register (37-47)
3781 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3782 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3783 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3784 CONFIG_SYS_BR1_PRELIM:
3785 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3787 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3788 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3789 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3790 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3792 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3793 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3794 Machine Mode Register and Memory Periodic Timer
3795 Prescaler definitions (SDRAM timing)
3797 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3798 enable I2C microcode relocation patch (MPC8xx);
3799 define relocation offset in DPRAM [DSP2]
3801 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3802 enable SMC microcode relocation patch (MPC8xx);
3803 define relocation offset in DPRAM [SMC1]
3805 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3806 enable SPI microcode relocation patch (MPC8xx);
3807 define relocation offset in DPRAM [SCC4]
3809 - CONFIG_SYS_USE_OSCCLK:
3810 Use OSCM clock mode on MBX8xx board. Be careful,
3811 wrong setting might damage your board. Read
3812 doc/README.MBX before setting this variable!
3814 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3815 Offset of the bootmode word in DPRAM used by post
3816 (Power On Self Tests). This definition overrides
3817 #define'd default value in commproc.h resp.
3820 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3821 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3822 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3823 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3824 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3825 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3826 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3827 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3828 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3830 - CONFIG_PCI_DISABLE_PCIE:
3831 Disable PCI-Express on systems where it is supported but not
3834 - CONFIG_PCI_ENUM_ONLY
3835 Only scan through and get the devices on the busses.
3836 Don't do any setup work, presumably because someone or
3837 something has already done it, and we don't need to do it
3838 a second time. Useful for platforms that are pre-booted
3839 by coreboot or similar.
3842 Chip has SRIO or not
3845 Board has SRIO 1 port available
3848 Board has SRIO 2 port available
3850 - CONFIG_SYS_SRIOn_MEM_VIRT:
3851 Virtual Address of SRIO port 'n' memory region
3853 - CONFIG_SYS_SRIOn_MEM_PHYS:
3854 Physical Address of SRIO port 'n' memory region
3856 - CONFIG_SYS_SRIOn_MEM_SIZE:
3857 Size of SRIO port 'n' memory region
3859 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3860 Defined to tell the NAND controller that the NAND chip is using
3862 Not all NAND drivers use this symbol.
3863 Example of drivers that use it:
3864 - drivers/mtd/nand/ndfc.c
3865 - drivers/mtd/nand/mxc_nand.c
3867 - CONFIG_SYS_NDFC_EBC0_CFG
3868 Sets the EBC0_CFG register for the NDFC. If not defined
3869 a default value will be used.
3872 Get DDR timing information from an I2C EEPROM. Common
3873 with pluggable memory modules such as SODIMMs
3876 I2C address of the SPD EEPROM
3878 - CONFIG_SYS_SPD_BUS_NUM
3879 If SPD EEPROM is on an I2C bus other than the first
3880 one, specify here. Note that the value must resolve
3881 to something your driver can deal with.
3883 - CONFIG_SYS_DDR_RAW_TIMING
3884 Get DDR timing information from other than SPD. Common with
3885 soldered DDR chips onboard without SPD. DDR raw timing
3886 parameters are extracted from datasheet and hard-coded into
3887 header files or board specific files.
3889 - CONFIG_FSL_DDR_INTERACTIVE
3890 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3892 - CONFIG_SYS_83XX_DDR_USES_CS0
3893 Only for 83xx systems. If specified, then DDR should
3894 be configured using CS0 and CS1 instead of CS2 and CS3.
3896 - CONFIG_ETHER_ON_FEC[12]
3897 Define to enable FEC[12] on a 8xx series processor.
3899 - CONFIG_FEC[12]_PHY
3900 Define to the hardcoded PHY address which corresponds
3901 to the given FEC; i. e.
3902 #define CONFIG_FEC1_PHY 4
3903 means that the PHY with address 4 is connected to FEC1
3905 When set to -1, means to probe for first available.
3907 - CONFIG_FEC[12]_PHY_NORXERR
3908 The PHY does not have a RXERR line (RMII only).
3909 (so program the FEC to ignore it).
3912 Enable RMII mode for all FECs.
3913 Note that this is a global option, we can't
3914 have one FEC in standard MII mode and another in RMII mode.
3916 - CONFIG_CRC32_VERIFY
3917 Add a verify option to the crc32 command.
3920 => crc32 -v <address> <count> <crc32>
3922 Where address/count indicate a memory area
3923 and crc32 is the correct crc32 which the
3927 Add the "loopw" memory command. This only takes effect if
3928 the memory commands are activated globally (CONFIG_CMD_MEM).
3931 Add the "mdc" and "mwc" memory commands. These are cyclic
3936 This command will print 4 bytes (10,11,12,13) each 500 ms.
3938 => mwc.l 100 12345678 10
3939 This command will write 12345678 to address 100 all 10 ms.
3941 This only takes effect if the memory commands are activated
3942 globally (CONFIG_CMD_MEM).
3944 - CONFIG_SKIP_LOWLEVEL_INIT
3945 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3946 low level initializations (like setting up the memory
3947 controller) are omitted and/or U-Boot does not
3948 relocate itself into RAM.
3950 Normally this variable MUST NOT be defined. The only
3951 exception is when U-Boot is loaded (to RAM) by some
3952 other boot loader or by a debugger which performs
3953 these initializations itself.
3956 Modifies the behaviour of start.S when compiling a loader
3957 that is executed before the actual U-Boot. E.g. when
3958 compiling a NAND SPL.
3960 - CONFIG_ARCH_MAP_SYSMEM
3961 Generally U-Boot (and in particular the md command) uses
3962 effective address. It is therefore not necessary to regard
3963 U-Boot address as virtual addresses that need to be translated
3964 to physical addresses. However, sandbox requires this, since
3965 it maintains its own little RAM buffer which contains all
3966 addressable memory. This option causes some memory accesses
3967 to be mapped through map_sysmem() / unmap_sysmem().
3969 - CONFIG_USE_ARCH_MEMCPY
3970 CONFIG_USE_ARCH_MEMSET
3971 If these options are used a optimized version of memcpy/memset will
3972 be used if available. These functions may be faster under some
3973 conditions but may increase the binary size.
3975 - CONFIG_X86_RESET_VECTOR
3976 If defined, the x86 reset vector code is included. This is not
3977 needed when U-Boot is running from Coreboot.
3980 Defines the MPU clock speed (in MHz).
3982 NOTE : currently only supported on AM335x platforms.
3984 Freescale QE/FMAN Firmware Support:
3985 -----------------------------------
3987 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3988 loading of "firmware", which is encoded in the QE firmware binary format.
3989 This firmware often needs to be loaded during U-Boot booting, so macros
3990 are used to identify the storage device (NOR flash, SPI, etc) and the address
3993 - CONFIG_SYS_QE_FMAN_FW_ADDR
3994 The address in the storage device where the firmware is located. The
3995 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3998 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3999 The maximum possible size of the firmware. The firmware binary format
4000 has a field that specifies the actual size of the firmware, but it
4001 might not be possible to read any part of the firmware unless some
4002 local storage is allocated to hold the entire firmware first.
4004 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4005 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4006 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4007 virtual address in NOR flash.
4009 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4010 Specifies that QE/FMAN firmware is located in NAND flash.
4011 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4013 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4014 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4015 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4017 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4018 Specifies that QE/FMAN firmware is located on the primary SPI
4019 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4021 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4022 Specifies that QE/FMAN firmware is located in the remote (master)
4023 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4024 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4025 window->master inbound window->master LAW->the ucode address in
4026 master's memory space.
4028 Building the Software:
4029 ======================
4031 Building U-Boot has been tested in several native build environments
4032 and in many different cross environments. Of course we cannot support
4033 all possibly existing versions of cross development tools in all
4034 (potentially obsolete) versions. In case of tool chain problems we
4035 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4036 which is extensively used to build and test U-Boot.
4038 If you are not using a native environment, it is assumed that you
4039 have GNU cross compiling tools available in your path. In this case,
4040 you must set the environment variable CROSS_COMPILE in your shell.
4041 Note that no changes to the Makefile or any other source files are
4042 necessary. For example using the ELDK on a 4xx CPU, please enter:
4044 $ CROSS_COMPILE=ppc_4xx-
4045 $ export CROSS_COMPILE
4047 Note: If you wish to generate Windows versions of the utilities in
4048 the tools directory you can use the MinGW toolchain
4049 (http://www.mingw.org). Set your HOST tools to the MinGW
4050 toolchain and execute 'make tools'. For example:
4052 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4054 Binaries such as tools/mkimage.exe will be created which can
4055 be executed on computers running Windows.
4057 U-Boot is intended to be simple to build. After installing the
4058 sources you must configure U-Boot for one specific board type. This
4063 where "NAME_config" is the name of one of the existing configu-
4064 rations; see boards.cfg for supported names.
4066 Note: for some board special configuration names may exist; check if
4067 additional information is available from the board vendor; for
4068 instance, the TQM823L systems are available without (standard)
4069 or with LCD support. You can select such additional "features"
4070 when choosing the configuration, i. e.
4073 - will configure for a plain TQM823L, i. e. no LCD support
4075 make TQM823L_LCD_config
4076 - will configure for a TQM823L with U-Boot console on LCD
4081 Finally, type "make all", and you should get some working U-Boot
4082 images ready for download to / installation on your system:
4084 - "u-boot.bin" is a raw binary image
4085 - "u-boot" is an image in ELF binary format
4086 - "u-boot.srec" is in Motorola S-Record format
4088 By default the build is performed locally and the objects are saved
4089 in the source directory. One of the two methods can be used to change
4090 this behavior and build U-Boot to some external directory:
4092 1. Add O= to the make command line invocations:
4094 make O=/tmp/build distclean
4095 make O=/tmp/build NAME_config
4096 make O=/tmp/build all
4098 2. Set environment variable BUILD_DIR to point to the desired location:
4100 export BUILD_DIR=/tmp/build
4105 Note that the command line "O=" setting overrides the BUILD_DIR environment
4109 Please be aware that the Makefiles assume you are using GNU make, so
4110 for instance on NetBSD you might need to use "gmake" instead of
4114 If the system board that you have is not listed, then you will need
4115 to port U-Boot to your hardware platform. To do this, follow these
4118 1. Add a new configuration option for your board to the toplevel
4119 "boards.cfg" file, using the existing entries as examples.
4120 Follow the instructions there to keep the boards in order.
4121 2. Create a new directory to hold your board specific code. Add any
4122 files you need. In your board directory, you will need at least
4123 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4124 3. Create a new configuration file "include/configs/<board>.h" for
4126 3. If you're porting U-Boot to a new CPU, then also create a new
4127 directory to hold your CPU specific code. Add any files you need.
4128 4. Run "make <board>_config" with your new name.
4129 5. Type "make", and you should get a working "u-boot.srec" file
4130 to be installed on your target system.
4131 6. Debug and solve any problems that might arise.
4132 [Of course, this last step is much harder than it sounds.]
4135 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4136 ==============================================================
4138 If you have modified U-Boot sources (for instance added a new board
4139 or support for new devices, a new CPU, etc.) you are expected to
4140 provide feedback to the other developers. The feedback normally takes
4141 the form of a "patch", i. e. a context diff against a certain (latest
4142 official or latest in the git repository) version of U-Boot sources.
4144 But before you submit such a patch, please verify that your modifi-
4145 cation did not break existing code. At least make sure that *ALL* of
4146 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4147 just run the "MAKEALL" script, which will configure and build U-Boot
4148 for ALL supported system. Be warned, this will take a while. You can
4149 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4150 environment variable to the script, i. e. to use the ELDK cross tools
4153 CROSS_COMPILE=ppc_8xx- MAKEALL
4155 or to build on a native PowerPC system you can type
4157 CROSS_COMPILE=' ' MAKEALL
4159 When using the MAKEALL script, the default behaviour is to build
4160 U-Boot in the source directory. This location can be changed by
4161 setting the BUILD_DIR environment variable. Also, for each target
4162 built, the MAKEALL script saves two log files (<target>.ERR and
4163 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4164 location can be changed by setting the MAKEALL_LOGDIR environment
4165 variable. For example:
4167 export BUILD_DIR=/tmp/build
4168 export MAKEALL_LOGDIR=/tmp/log
4169 CROSS_COMPILE=ppc_8xx- MAKEALL
4171 With the above settings build objects are saved in the /tmp/build,
4172 log files are saved in the /tmp/log and the source tree remains clean
4173 during the whole build process.
4176 See also "U-Boot Porting Guide" below.
4179 Monitor Commands - Overview:
4180 ============================
4182 go - start application at address 'addr'
4183 run - run commands in an environment variable
4184 bootm - boot application image from memory
4185 bootp - boot image via network using BootP/TFTP protocol
4186 bootz - boot zImage from memory
4187 tftpboot- boot image via network using TFTP protocol
4188 and env variables "ipaddr" and "serverip"
4189 (and eventually "gatewayip")
4190 tftpput - upload a file via network using TFTP protocol
4191 rarpboot- boot image via network using RARP/TFTP protocol
4192 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4193 loads - load S-Record file over serial line
4194 loadb - load binary file over serial line (kermit mode)
4196 mm - memory modify (auto-incrementing)
4197 nm - memory modify (constant address)
4198 mw - memory write (fill)
4200 cmp - memory compare
4201 crc32 - checksum calculation
4202 i2c - I2C sub-system
4203 sspi - SPI utility commands
4204 base - print or set address offset
4205 printenv- print environment variables
4206 setenv - set environment variables
4207 saveenv - save environment variables to persistent storage
4208 protect - enable or disable FLASH write protection
4209 erase - erase FLASH memory
4210 flinfo - print FLASH memory information
4211 nand - NAND memory operations (see doc/README.nand)
4212 bdinfo - print Board Info structure
4213 iminfo - print header information for application image
4214 coninfo - print console devices and informations
4215 ide - IDE sub-system
4216 loop - infinite loop on address range
4217 loopw - infinite write loop on address range
4218 mtest - simple RAM test
4219 icache - enable or disable instruction cache
4220 dcache - enable or disable data cache
4221 reset - Perform RESET of the CPU
4222 echo - echo args to console
4223 version - print monitor version
4224 help - print online help
4225 ? - alias for 'help'
4228 Monitor Commands - Detailed Description:
4229 ========================================
4233 For now: just type "help <command>".
4236 Environment Variables:
4237 ======================
4239 U-Boot supports user configuration using Environment Variables which
4240 can be made persistent by saving to Flash memory.
4242 Environment Variables are set using "setenv", printed using
4243 "printenv", and saved to Flash using "saveenv". Using "setenv"
4244 without a value can be used to delete a variable from the
4245 environment. As long as you don't save the environment you are
4246 working with an in-memory copy. In case the Flash area containing the
4247 environment is erased by accident, a default environment is provided.
4249 Some configuration options can be set using Environment Variables.
4251 List of environment variables (most likely not complete):
4253 baudrate - see CONFIG_BAUDRATE
4255 bootdelay - see CONFIG_BOOTDELAY
4257 bootcmd - see CONFIG_BOOTCOMMAND
4259 bootargs - Boot arguments when booting an RTOS image
4261 bootfile - Name of the image to load with TFTP
4263 bootm_low - Memory range available for image processing in the bootm
4264 command can be restricted. This variable is given as
4265 a hexadecimal number and defines lowest address allowed
4266 for use by the bootm command. See also "bootm_size"
4267 environment variable. Address defined by "bootm_low" is
4268 also the base of the initial memory mapping for the Linux
4269 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4272 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4273 This variable is given as a hexadecimal number and it
4274 defines the size of the memory region starting at base
4275 address bootm_low that is accessible by the Linux kernel
4276 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4277 as the default value if it is defined, and bootm_size is
4280 bootm_size - Memory range available for image processing in the bootm
4281 command can be restricted. This variable is given as
4282 a hexadecimal number and defines the size of the region
4283 allowed for use by the bootm command. See also "bootm_low"
4284 environment variable.
4286 updatefile - Location of the software update file on a TFTP server, used
4287 by the automatic software update feature. Please refer to
4288 documentation in doc/README.update for more details.
4290 autoload - if set to "no" (any string beginning with 'n'),
4291 "bootp" will just load perform a lookup of the
4292 configuration from the BOOTP server, but not try to
4293 load any image using TFTP
4295 autostart - if set to "yes", an image loaded using the "bootp",
4296 "rarpboot", "tftpboot" or "diskboot" commands will
4297 be automatically started (by internally calling
4300 If set to "no", a standalone image passed to the
4301 "bootm" command will be copied to the load address
4302 (and eventually uncompressed), but NOT be started.
4303 This can be used to load and uncompress arbitrary
4306 fdt_high - if set this restricts the maximum address that the
4307 flattened device tree will be copied into upon boot.
4308 For example, if you have a system with 1 GB memory
4309 at physical address 0x10000000, while Linux kernel
4310 only recognizes the first 704 MB as low memory, you
4311 may need to set fdt_high as 0x3C000000 to have the
4312 device tree blob be copied to the maximum address
4313 of the 704 MB low memory, so that Linux kernel can
4314 access it during the boot procedure.
4316 If this is set to the special value 0xFFFFFFFF then
4317 the fdt will not be copied at all on boot. For this
4318 to work it must reside in writable memory, have
4319 sufficient padding on the end of it for u-boot to
4320 add the information it needs into it, and the memory
4321 must be accessible by the kernel.
4323 fdtcontroladdr- if set this is the address of the control flattened
4324 device tree used by U-Boot when CONFIG_OF_CONTROL is
4327 i2cfast - (PPC405GP|PPC405EP only)
4328 if set to 'y' configures Linux I2C driver for fast
4329 mode (400kHZ). This environment variable is used in
4330 initialization code. So, for changes to be effective
4331 it must be saved and board must be reset.
4333 initrd_high - restrict positioning of initrd images:
4334 If this variable is not set, initrd images will be
4335 copied to the highest possible address in RAM; this
4336 is usually what you want since it allows for
4337 maximum initrd size. If for some reason you want to
4338 make sure that the initrd image is loaded below the
4339 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4340 variable to a value of "no" or "off" or "0".
4341 Alternatively, you can set it to a maximum upper
4342 address to use (U-Boot will still check that it
4343 does not overwrite the U-Boot stack and data).
4345 For instance, when you have a system with 16 MB
4346 RAM, and want to reserve 4 MB from use by Linux,
4347 you can do this by adding "mem=12M" to the value of
4348 the "bootargs" variable. However, now you must make
4349 sure that the initrd image is placed in the first
4350 12 MB as well - this can be done with
4352 setenv initrd_high 00c00000
4354 If you set initrd_high to 0xFFFFFFFF, this is an
4355 indication to U-Boot that all addresses are legal
4356 for the Linux kernel, including addresses in flash
4357 memory. In this case U-Boot will NOT COPY the
4358 ramdisk at all. This may be useful to reduce the
4359 boot time on your system, but requires that this
4360 feature is supported by your Linux kernel.
4362 ipaddr - IP address; needed for tftpboot command
4364 loadaddr - Default load address for commands like "bootp",
4365 "rarpboot", "tftpboot", "loadb" or "diskboot"
4367 loads_echo - see CONFIG_LOADS_ECHO
4369 serverip - TFTP server IP address; needed for tftpboot command
4371 bootretry - see CONFIG_BOOT_RETRY_TIME
4373 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4375 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4377 ethprime - controls which interface is used first.
4379 ethact - controls which interface is currently active.
4380 For example you can do the following
4382 => setenv ethact FEC
4383 => ping 192.168.0.1 # traffic sent on FEC
4384 => setenv ethact SCC
4385 => ping 10.0.0.1 # traffic sent on SCC
4387 ethrotate - When set to "no" U-Boot does not go through all
4388 available network interfaces.
4389 It just stays at the currently selected interface.
4391 netretry - When set to "no" each network operation will
4392 either succeed or fail without retrying.
4393 When set to "once" the network operation will
4394 fail when all the available network interfaces
4395 are tried once without success.
4396 Useful on scripts which control the retry operation
4399 npe_ucode - set load address for the NPE microcode
4401 tftpsrcport - If this is set, the value is used for TFTP's
4404 tftpdstport - If this is set, the value is used for TFTP's UDP
4405 destination port instead of the Well Know Port 69.
4407 tftpblocksize - Block size to use for TFTP transfers; if not set,
4408 we use the TFTP server's default block size
4410 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4411 seconds, minimum value is 1000 = 1 second). Defines
4412 when a packet is considered to be lost so it has to
4413 be retransmitted. The default is 5000 = 5 seconds.
4414 Lowering this value may make downloads succeed
4415 faster in networks with high packet loss rates or
4416 with unreliable TFTP servers.
4418 vlan - When set to a value < 4095 the traffic over
4419 Ethernet is encapsulated/received over 802.1q
4422 The following image location variables contain the location of images
4423 used in booting. The "Image" column gives the role of the image and is
4424 not an environment variable name. The other columns are environment
4425 variable names. "File Name" gives the name of the file on a TFTP
4426 server, "RAM Address" gives the location in RAM the image will be
4427 loaded to, and "Flash Location" gives the image's address in NOR
4428 flash or offset in NAND flash.
4430 *Note* - these variables don't have to be defined for all boards, some
4431 boards currenlty use other variables for these purposes, and some
4432 boards use these variables for other purposes.
4434 Image File Name RAM Address Flash Location
4435 ----- --------- ----------- --------------
4436 u-boot u-boot u-boot_addr_r u-boot_addr
4437 Linux kernel bootfile kernel_addr_r kernel_addr
4438 device tree blob fdtfile fdt_addr_r fdt_addr
4439 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4441 The following environment variables may be used and automatically
4442 updated by the network boot commands ("bootp" and "rarpboot"),
4443 depending the information provided by your boot server:
4445 bootfile - see above
4446 dnsip - IP address of your Domain Name Server
4447 dnsip2 - IP address of your secondary Domain Name Server
4448 gatewayip - IP address of the Gateway (Router) to use
4449 hostname - Target hostname
4451 netmask - Subnet Mask
4452 rootpath - Pathname of the root filesystem on the NFS server
4453 serverip - see above
4456 There are two special Environment Variables:
4458 serial# - contains hardware identification information such
4459 as type string and/or serial number
4460 ethaddr - Ethernet address
4462 These variables can be set only once (usually during manufacturing of
4463 the board). U-Boot refuses to delete or overwrite these variables
4464 once they have been set once.
4467 Further special Environment Variables:
4469 ver - Contains the U-Boot version string as printed
4470 with the "version" command. This variable is
4471 readonly (see CONFIG_VERSION_VARIABLE).
4474 Please note that changes to some configuration parameters may take
4475 only effect after the next boot (yes, that's just like Windoze :-).
4478 Callback functions for environment variables:
4479 ---------------------------------------------
4481 For some environment variables, the behavior of u-boot needs to change
4482 when their values are changed. This functionailty allows functions to
4483 be associated with arbitrary variables. On creation, overwrite, or
4484 deletion, the callback will provide the opportunity for some side
4485 effect to happen or for the change to be rejected.
4487 The callbacks are named and associated with a function using the
4488 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4490 These callbacks are associated with variables in one of two ways. The
4491 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4492 in the board configuration to a string that defines a list of
4493 associations. The list must be in the following format:
4495 entry = variable_name[:callback_name]
4498 If the callback name is not specified, then the callback is deleted.
4499 Spaces are also allowed anywhere in the list.
4501 Callbacks can also be associated by defining the ".callbacks" variable
4502 with the same list format above. Any association in ".callbacks" will
4503 override any association in the static list. You can define
4504 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4505 ".callbacks" envirnoment variable in the default or embedded environment.
4508 Command Line Parsing:
4509 =====================
4511 There are two different command line parsers available with U-Boot:
4512 the old "simple" one, and the much more powerful "hush" shell:
4514 Old, simple command line parser:
4515 --------------------------------
4517 - supports environment variables (through setenv / saveenv commands)
4518 - several commands on one line, separated by ';'
4519 - variable substitution using "... ${name} ..." syntax
4520 - special characters ('$', ';') can be escaped by prefixing with '\',
4522 setenv bootcmd bootm \${address}
4523 - You can also escape text by enclosing in single apostrophes, for example:
4524 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4529 - similar to Bourne shell, with control structures like
4530 if...then...else...fi, for...do...done; while...do...done,
4531 until...do...done, ...
4532 - supports environment ("global") variables (through setenv / saveenv
4533 commands) and local shell variables (through standard shell syntax
4534 "name=value"); only environment variables can be used with "run"
4540 (1) If a command line (or an environment variable executed by a "run"
4541 command) contains several commands separated by semicolon, and
4542 one of these commands fails, then the remaining commands will be
4545 (2) If you execute several variables with one call to run (i. e.
4546 calling run with a list of variables as arguments), any failing
4547 command will cause "run" to terminate, i. e. the remaining
4548 variables are not executed.
4550 Note for Redundant Ethernet Interfaces:
4551 =======================================
4553 Some boards come with redundant Ethernet interfaces; U-Boot supports
4554 such configurations and is capable of automatic selection of a
4555 "working" interface when needed. MAC assignment works as follows:
4557 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4558 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4559 "eth1addr" (=>eth1), "eth2addr", ...
4561 If the network interface stores some valid MAC address (for instance
4562 in SROM), this is used as default address if there is NO correspon-
4563 ding setting in the environment; if the corresponding environment
4564 variable is set, this overrides the settings in the card; that means:
4566 o If the SROM has a valid MAC address, and there is no address in the
4567 environment, the SROM's address is used.
4569 o If there is no valid address in the SROM, and a definition in the
4570 environment exists, then the value from the environment variable is
4573 o If both the SROM and the environment contain a MAC address, and
4574 both addresses are the same, this MAC address is used.
4576 o If both the SROM and the environment contain a MAC address, and the
4577 addresses differ, the value from the environment is used and a
4580 o If neither SROM nor the environment contain a MAC address, an error
4583 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4584 will be programmed into hardware as part of the initialization process. This
4585 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4586 The naming convention is as follows:
4587 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4592 U-Boot is capable of booting (and performing other auxiliary operations on)
4593 images in two formats:
4595 New uImage format (FIT)
4596 -----------------------
4598 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4599 to Flattened Device Tree). It allows the use of images with multiple
4600 components (several kernels, ramdisks, etc.), with contents protected by
4601 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4607 Old image format is based on binary files which can be basically anything,
4608 preceded by a special header; see the definitions in include/image.h for
4609 details; basically, the header defines the following image properties:
4611 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4612 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4613 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4614 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4616 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4617 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4618 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4619 * Compression Type (uncompressed, gzip, bzip2)
4625 The header is marked by a special Magic Number, and both the header
4626 and the data portions of the image are secured against corruption by
4633 Although U-Boot should support any OS or standalone application
4634 easily, the main focus has always been on Linux during the design of
4637 U-Boot includes many features that so far have been part of some
4638 special "boot loader" code within the Linux kernel. Also, any
4639 "initrd" images to be used are no longer part of one big Linux image;
4640 instead, kernel and "initrd" are separate images. This implementation
4641 serves several purposes:
4643 - the same features can be used for other OS or standalone
4644 applications (for instance: using compressed images to reduce the
4645 Flash memory footprint)
4647 - it becomes much easier to port new Linux kernel versions because
4648 lots of low-level, hardware dependent stuff are done by U-Boot
4650 - the same Linux kernel image can now be used with different "initrd"
4651 images; of course this also means that different kernel images can
4652 be run with the same "initrd". This makes testing easier (you don't
4653 have to build a new "zImage.initrd" Linux image when you just
4654 change a file in your "initrd"). Also, a field-upgrade of the
4655 software is easier now.
4661 Porting Linux to U-Boot based systems:
4662 ---------------------------------------
4664 U-Boot cannot save you from doing all the necessary modifications to
4665 configure the Linux device drivers for use with your target hardware
4666 (no, we don't intend to provide a full virtual machine interface to
4669 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4671 Just make sure your machine specific header file (for instance
4672 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4673 Information structure as we define in include/asm-<arch>/u-boot.h,
4674 and make sure that your definition of IMAP_ADDR uses the same value
4675 as your U-Boot configuration in CONFIG_SYS_IMMR.
4678 Configuring the Linux kernel:
4679 -----------------------------
4681 No specific requirements for U-Boot. Make sure you have some root
4682 device (initial ramdisk, NFS) for your target system.
4685 Building a Linux Image:
4686 -----------------------
4688 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4689 not used. If you use recent kernel source, a new build target
4690 "uImage" will exist which automatically builds an image usable by
4691 U-Boot. Most older kernels also have support for a "pImage" target,
4692 which was introduced for our predecessor project PPCBoot and uses a
4693 100% compatible format.
4702 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4703 encapsulate a compressed Linux kernel image with header information,
4704 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4706 * build a standard "vmlinux" kernel image (in ELF binary format):
4708 * convert the kernel into a raw binary image:
4710 ${CROSS_COMPILE}-objcopy -O binary \
4711 -R .note -R .comment \
4712 -S vmlinux linux.bin
4714 * compress the binary image:
4718 * package compressed binary image for U-Boot:
4720 mkimage -A ppc -O linux -T kernel -C gzip \
4721 -a 0 -e 0 -n "Linux Kernel Image" \
4722 -d linux.bin.gz uImage
4725 The "mkimage" tool can also be used to create ramdisk images for use
4726 with U-Boot, either separated from the Linux kernel image, or
4727 combined into one file. "mkimage" encapsulates the images with a 64
4728 byte header containing information about target architecture,
4729 operating system, image type, compression method, entry points, time
4730 stamp, CRC32 checksums, etc.
4732 "mkimage" can be called in two ways: to verify existing images and
4733 print the header information, or to build new images.
4735 In the first form (with "-l" option) mkimage lists the information
4736 contained in the header of an existing U-Boot image; this includes
4737 checksum verification:
4739 tools/mkimage -l image
4740 -l ==> list image header information
4742 The second form (with "-d" option) is used to build a U-Boot image
4743 from a "data file" which is used as image payload:
4745 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4746 -n name -d data_file image
4747 -A ==> set architecture to 'arch'
4748 -O ==> set operating system to 'os'
4749 -T ==> set image type to 'type'
4750 -C ==> set compression type 'comp'
4751 -a ==> set load address to 'addr' (hex)
4752 -e ==> set entry point to 'ep' (hex)
4753 -n ==> set image name to 'name'
4754 -d ==> use image data from 'datafile'
4756 Right now, all Linux kernels for PowerPC systems use the same load
4757 address (0x00000000), but the entry point address depends on the
4760 - 2.2.x kernels have the entry point at 0x0000000C,
4761 - 2.3.x and later kernels have the entry point at 0x00000000.
4763 So a typical call to build a U-Boot image would read:
4765 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4766 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4767 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4768 > examples/uImage.TQM850L
4769 Image Name: 2.4.4 kernel for TQM850L
4770 Created: Wed Jul 19 02:34:59 2000
4771 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4772 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4773 Load Address: 0x00000000
4774 Entry Point: 0x00000000
4776 To verify the contents of the image (or check for corruption):
4778 -> tools/mkimage -l examples/uImage.TQM850L
4779 Image Name: 2.4.4 kernel for TQM850L
4780 Created: Wed Jul 19 02:34:59 2000
4781 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4782 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4783 Load Address: 0x00000000
4784 Entry Point: 0x00000000
4786 NOTE: for embedded systems where boot time is critical you can trade
4787 speed for memory and install an UNCOMPRESSED image instead: this
4788 needs more space in Flash, but boots much faster since it does not
4789 need to be uncompressed:
4791 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4792 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4793 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4794 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4795 > examples/uImage.TQM850L-uncompressed
4796 Image Name: 2.4.4 kernel for TQM850L
4797 Created: Wed Jul 19 02:34:59 2000
4798 Image Type: PowerPC Linux Kernel Image (uncompressed)
4799 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4800 Load Address: 0x00000000
4801 Entry Point: 0x00000000
4804 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4805 when your kernel is intended to use an initial ramdisk:
4807 -> tools/mkimage -n 'Simple Ramdisk Image' \
4808 > -A ppc -O linux -T ramdisk -C gzip \
4809 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4810 Image Name: Simple Ramdisk Image
4811 Created: Wed Jan 12 14:01:50 2000
4812 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4813 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4814 Load Address: 0x00000000
4815 Entry Point: 0x00000000
4818 Installing a Linux Image:
4819 -------------------------
4821 To downloading a U-Boot image over the serial (console) interface,
4822 you must convert the image to S-Record format:
4824 objcopy -I binary -O srec examples/image examples/image.srec
4826 The 'objcopy' does not understand the information in the U-Boot
4827 image header, so the resulting S-Record file will be relative to
4828 address 0x00000000. To load it to a given address, you need to
4829 specify the target address as 'offset' parameter with the 'loads'
4832 Example: install the image to address 0x40100000 (which on the
4833 TQM8xxL is in the first Flash bank):
4835 => erase 40100000 401FFFFF
4841 ## Ready for S-Record download ...
4842 ~>examples/image.srec
4843 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4845 15989 15990 15991 15992
4846 [file transfer complete]
4848 ## Start Addr = 0x00000000
4851 You can check the success of the download using the 'iminfo' command;
4852 this includes a checksum verification so you can be sure no data
4853 corruption happened:
4857 ## Checking Image at 40100000 ...
4858 Image Name: 2.2.13 for initrd on TQM850L
4859 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4860 Data Size: 335725 Bytes = 327 kB = 0 MB
4861 Load Address: 00000000
4862 Entry Point: 0000000c
4863 Verifying Checksum ... OK
4869 The "bootm" command is used to boot an application that is stored in
4870 memory (RAM or Flash). In case of a Linux kernel image, the contents
4871 of the "bootargs" environment variable is passed to the kernel as
4872 parameters. You can check and modify this variable using the
4873 "printenv" and "setenv" commands:
4876 => printenv bootargs
4877 bootargs=root=/dev/ram
4879 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4881 => printenv bootargs
4882 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4885 ## Booting Linux kernel at 40020000 ...
4886 Image Name: 2.2.13 for NFS on TQM850L
4887 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4888 Data Size: 381681 Bytes = 372 kB = 0 MB
4889 Load Address: 00000000
4890 Entry Point: 0000000c
4891 Verifying Checksum ... OK
4892 Uncompressing Kernel Image ... OK
4893 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
4894 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4895 time_init: decrementer frequency = 187500000/60
4896 Calibrating delay loop... 49.77 BogoMIPS
4897 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4900 If you want to boot a Linux kernel with initial RAM disk, you pass
4901 the memory addresses of both the kernel and the initrd image (PPBCOOT
4902 format!) to the "bootm" command:
4904 => imi 40100000 40200000
4906 ## Checking Image at 40100000 ...
4907 Image Name: 2.2.13 for initrd on TQM850L
4908 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4909 Data Size: 335725 Bytes = 327 kB = 0 MB
4910 Load Address: 00000000
4911 Entry Point: 0000000c
4912 Verifying Checksum ... OK
4914 ## Checking Image at 40200000 ...
4915 Image Name: Simple Ramdisk Image
4916 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4917 Data Size: 566530 Bytes = 553 kB = 0 MB
4918 Load Address: 00000000
4919 Entry Point: 00000000
4920 Verifying Checksum ... OK
4922 => bootm 40100000 40200000
4923 ## Booting Linux kernel at 40100000 ...
4924 Image Name: 2.2.13 for initrd on TQM850L
4925 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4926 Data Size: 335725 Bytes = 327 kB = 0 MB
4927 Load Address: 00000000
4928 Entry Point: 0000000c
4929 Verifying Checksum ... OK
4930 Uncompressing Kernel Image ... OK
4931 ## Loading RAMDisk Image at 40200000 ...
4932 Image Name: Simple Ramdisk Image
4933 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4934 Data Size: 566530 Bytes = 553 kB = 0 MB
4935 Load Address: 00000000
4936 Entry Point: 00000000
4937 Verifying Checksum ... OK
4938 Loading Ramdisk ... OK
4939 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
4940 Boot arguments: root=/dev/ram
4941 time_init: decrementer frequency = 187500000/60
4942 Calibrating delay loop... 49.77 BogoMIPS
4944 RAMDISK: Compressed image found at block 0
4945 VFS: Mounted root (ext2 filesystem).
4949 Boot Linux and pass a flat device tree:
4952 First, U-Boot must be compiled with the appropriate defines. See the section
4953 titled "Linux Kernel Interface" above for a more in depth explanation. The
4954 following is an example of how to start a kernel and pass an updated
4960 oft=oftrees/mpc8540ads.dtb
4961 => tftp $oftaddr $oft
4962 Speed: 1000, full duplex
4964 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4965 Filename 'oftrees/mpc8540ads.dtb'.
4966 Load address: 0x300000
4969 Bytes transferred = 4106 (100a hex)
4970 => tftp $loadaddr $bootfile
4971 Speed: 1000, full duplex
4973 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4975 Load address: 0x200000
4976 Loading:############
4978 Bytes transferred = 1029407 (fb51f hex)
4983 => bootm $loadaddr - $oftaddr
4984 ## Booting image at 00200000 ...
4985 Image Name: Linux-2.6.17-dirty
4986 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4987 Data Size: 1029343 Bytes = 1005.2 kB
4988 Load Address: 00000000
4989 Entry Point: 00000000
4990 Verifying Checksum ... OK
4991 Uncompressing Kernel Image ... OK
4992 Booting using flat device tree at 0x300000
4993 Using MPC85xx ADS machine description
4994 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4998 More About U-Boot Image Types:
4999 ------------------------------
5001 U-Boot supports the following image types:
5003 "Standalone Programs" are directly runnable in the environment
5004 provided by U-Boot; it is expected that (if they behave
5005 well) you can continue to work in U-Boot after return from
5006 the Standalone Program.
5007 "OS Kernel Images" are usually images of some Embedded OS which
5008 will take over control completely. Usually these programs
5009 will install their own set of exception handlers, device
5010 drivers, set up the MMU, etc. - this means, that you cannot
5011 expect to re-enter U-Boot except by resetting the CPU.
5012 "RAMDisk Images" are more or less just data blocks, and their
5013 parameters (address, size) are passed to an OS kernel that is
5015 "Multi-File Images" contain several images, typically an OS
5016 (Linux) kernel image and one or more data images like
5017 RAMDisks. This construct is useful for instance when you want
5018 to boot over the network using BOOTP etc., where the boot
5019 server provides just a single image file, but you want to get
5020 for instance an OS kernel and a RAMDisk image.
5022 "Multi-File Images" start with a list of image sizes, each
5023 image size (in bytes) specified by an "uint32_t" in network
5024 byte order. This list is terminated by an "(uint32_t)0".
5025 Immediately after the terminating 0 follow the images, one by
5026 one, all aligned on "uint32_t" boundaries (size rounded up to
5027 a multiple of 4 bytes).
5029 "Firmware Images" are binary images containing firmware (like
5030 U-Boot or FPGA images) which usually will be programmed to
5033 "Script files" are command sequences that will be executed by
5034 U-Boot's command interpreter; this feature is especially
5035 useful when you configure U-Boot to use a real shell (hush)
5036 as command interpreter.
5038 Booting the Linux zImage:
5039 -------------------------
5041 On some platforms, it's possible to boot Linux zImage. This is done
5042 using the "bootz" command. The syntax of "bootz" command is the same
5043 as the syntax of "bootm" command.
5045 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
5046 kernel with raw initrd images. The syntax is slightly different, the
5047 address of the initrd must be augmented by it's size, in the following
5048 format: "<initrd addres>:<initrd size>".
5054 One of the features of U-Boot is that you can dynamically load and
5055 run "standalone" applications, which can use some resources of
5056 U-Boot like console I/O functions or interrupt services.
5058 Two simple examples are included with the sources:
5063 'examples/hello_world.c' contains a small "Hello World" Demo
5064 application; it is automatically compiled when you build U-Boot.
5065 It's configured to run at address 0x00040004, so you can play with it
5069 ## Ready for S-Record download ...
5070 ~>examples/hello_world.srec
5071 1 2 3 4 5 6 7 8 9 10 11 ...
5072 [file transfer complete]
5074 ## Start Addr = 0x00040004
5076 => go 40004 Hello World! This is a test.
5077 ## Starting application at 0x00040004 ...
5088 Hit any key to exit ...
5090 ## Application terminated, rc = 0x0
5092 Another example, which demonstrates how to register a CPM interrupt
5093 handler with the U-Boot code, can be found in 'examples/timer.c'.
5094 Here, a CPM timer is set up to generate an interrupt every second.
5095 The interrupt service routine is trivial, just printing a '.'
5096 character, but this is just a demo program. The application can be
5097 controlled by the following keys:
5099 ? - print current values og the CPM Timer registers
5100 b - enable interrupts and start timer
5101 e - stop timer and disable interrupts
5102 q - quit application
5105 ## Ready for S-Record download ...
5106 ~>examples/timer.srec
5107 1 2 3 4 5 6 7 8 9 10 11 ...
5108 [file transfer complete]
5110 ## Start Addr = 0x00040004
5113 ## Starting application at 0x00040004 ...
5116 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5119 [q, b, e, ?] Set interval 1000000 us
5122 [q, b, e, ?] ........
5123 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5126 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5129 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5132 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5134 [q, b, e, ?] ...Stopping timer
5136 [q, b, e, ?] ## Application terminated, rc = 0x0
5142 Over time, many people have reported problems when trying to use the
5143 "minicom" terminal emulation program for serial download. I (wd)
5144 consider minicom to be broken, and recommend not to use it. Under
5145 Unix, I recommend to use C-Kermit for general purpose use (and
5146 especially for kermit binary protocol download ("loadb" command), and
5147 use "cu" for S-Record download ("loads" command). See
5148 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5149 for help with kermit.
5152 Nevertheless, if you absolutely want to use it try adding this
5153 configuration to your "File transfer protocols" section:
5155 Name Program Name U/D FullScr IO-Red. Multi
5156 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5157 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5163 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5164 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5166 Building requires a cross environment; it is known to work on
5167 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5168 need gmake since the Makefiles are not compatible with BSD make).
5169 Note that the cross-powerpc package does not install include files;
5170 attempting to build U-Boot will fail because <machine/ansi.h> is
5171 missing. This file has to be installed and patched manually:
5173 # cd /usr/pkg/cross/powerpc-netbsd/include
5175 # ln -s powerpc machine
5176 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5177 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5179 Native builds *don't* work due to incompatibilities between native
5180 and U-Boot include files.
5182 Booting assumes that (the first part of) the image booted is a
5183 stage-2 loader which in turn loads and then invokes the kernel
5184 proper. Loader sources will eventually appear in the NetBSD source
5185 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5186 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5189 Implementation Internals:
5190 =========================
5192 The following is not intended to be a complete description of every
5193 implementation detail. However, it should help to understand the
5194 inner workings of U-Boot and make it easier to port it to custom
5198 Initial Stack, Global Data:
5199 ---------------------------
5201 The implementation of U-Boot is complicated by the fact that U-Boot
5202 starts running out of ROM (flash memory), usually without access to
5203 system RAM (because the memory controller is not initialized yet).
5204 This means that we don't have writable Data or BSS segments, and BSS
5205 is not initialized as zero. To be able to get a C environment working
5206 at all, we have to allocate at least a minimal stack. Implementation
5207 options for this are defined and restricted by the CPU used: Some CPU
5208 models provide on-chip memory (like the IMMR area on MPC8xx and
5209 MPC826x processors), on others (parts of) the data cache can be
5210 locked as (mis-) used as memory, etc.
5212 Chris Hallinan posted a good summary of these issues to the
5213 U-Boot mailing list:
5215 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5216 From: "Chris Hallinan" <clh@net1plus.com>
5217 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5220 Correct me if I'm wrong, folks, but the way I understand it
5221 is this: Using DCACHE as initial RAM for Stack, etc, does not
5222 require any physical RAM backing up the cache. The cleverness
5223 is that the cache is being used as a temporary supply of
5224 necessary storage before the SDRAM controller is setup. It's
5225 beyond the scope of this list to explain the details, but you
5226 can see how this works by studying the cache architecture and
5227 operation in the architecture and processor-specific manuals.
5229 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5230 is another option for the system designer to use as an
5231 initial stack/RAM area prior to SDRAM being available. Either
5232 option should work for you. Using CS 4 should be fine if your
5233 board designers haven't used it for something that would
5234 cause you grief during the initial boot! It is frequently not
5237 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5238 with your processor/board/system design. The default value
5239 you will find in any recent u-boot distribution in
5240 walnut.h should work for you. I'd set it to a value larger
5241 than your SDRAM module. If you have a 64MB SDRAM module, set
5242 it above 400_0000. Just make sure your board has no resources
5243 that are supposed to respond to that address! That code in
5244 start.S has been around a while and should work as is when
5245 you get the config right.
5250 It is essential to remember this, since it has some impact on the C
5251 code for the initialization procedures:
5253 * Initialized global data (data segment) is read-only. Do not attempt
5256 * Do not use any uninitialized global data (or implicitely initialized
5257 as zero data - BSS segment) at all - this is undefined, initiali-
5258 zation is performed later (when relocating to RAM).
5260 * Stack space is very limited. Avoid big data buffers or things like
5263 Having only the stack as writable memory limits means we cannot use
5264 normal global data to share information beween the code. But it
5265 turned out that the implementation of U-Boot can be greatly
5266 simplified by making a global data structure (gd_t) available to all
5267 functions. We could pass a pointer to this data as argument to _all_
5268 functions, but this would bloat the code. Instead we use a feature of
5269 the GCC compiler (Global Register Variables) to share the data: we
5270 place a pointer (gd) to the global data into a register which we
5271 reserve for this purpose.
5273 When choosing a register for such a purpose we are restricted by the
5274 relevant (E)ABI specifications for the current architecture, and by
5275 GCC's implementation.
5277 For PowerPC, the following registers have specific use:
5279 R2: reserved for system use
5280 R3-R4: parameter passing and return values
5281 R5-R10: parameter passing
5282 R13: small data area pointer
5286 (U-Boot also uses R12 as internal GOT pointer. r12
5287 is a volatile register so r12 needs to be reset when
5288 going back and forth between asm and C)
5290 ==> U-Boot will use R2 to hold a pointer to the global data
5292 Note: on PPC, we could use a static initializer (since the
5293 address of the global data structure is known at compile time),
5294 but it turned out that reserving a register results in somewhat
5295 smaller code - although the code savings are not that big (on
5296 average for all boards 752 bytes for the whole U-Boot image,
5297 624 text + 127 data).
5299 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5300 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5302 ==> U-Boot will use P3 to hold a pointer to the global data
5304 On ARM, the following registers are used:
5306 R0: function argument word/integer result
5307 R1-R3: function argument word
5309 R10: stack limit (used only if stack checking if enabled)
5310 R11: argument (frame) pointer
5311 R12: temporary workspace
5314 R15: program counter
5316 ==> U-Boot will use R8 to hold a pointer to the global data
5318 On Nios II, the ABI is documented here:
5319 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5321 ==> U-Boot will use gp to hold a pointer to the global data
5323 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5324 to access small data sections, so gp is free.
5326 On NDS32, the following registers are used:
5328 R0-R1: argument/return
5330 R15: temporary register for assembler
5331 R16: trampoline register
5332 R28: frame pointer (FP)
5333 R29: global pointer (GP)
5334 R30: link register (LP)
5335 R31: stack pointer (SP)
5336 PC: program counter (PC)
5338 ==> U-Boot will use R10 to hold a pointer to the global data
5340 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5341 or current versions of GCC may "optimize" the code too much.
5346 U-Boot runs in system state and uses physical addresses, i.e. the
5347 MMU is not used either for address mapping nor for memory protection.
5349 The available memory is mapped to fixed addresses using the memory
5350 controller. In this process, a contiguous block is formed for each
5351 memory type (Flash, SDRAM, SRAM), even when it consists of several
5352 physical memory banks.
5354 U-Boot is installed in the first 128 kB of the first Flash bank (on
5355 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5356 booting and sizing and initializing DRAM, the code relocates itself
5357 to the upper end of DRAM. Immediately below the U-Boot code some
5358 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5359 configuration setting]. Below that, a structure with global Board
5360 Info data is placed, followed by the stack (growing downward).
5362 Additionally, some exception handler code is copied to the low 8 kB
5363 of DRAM (0x00000000 ... 0x00001FFF).
5365 So a typical memory configuration with 16 MB of DRAM could look like
5368 0x0000 0000 Exception Vector code
5371 0x0000 2000 Free for Application Use
5377 0x00FB FF20 Monitor Stack (Growing downward)
5378 0x00FB FFAC Board Info Data and permanent copy of global data
5379 0x00FC 0000 Malloc Arena
5382 0x00FE 0000 RAM Copy of Monitor Code
5383 ... eventually: LCD or video framebuffer
5384 ... eventually: pRAM (Protected RAM - unchanged by reset)
5385 0x00FF FFFF [End of RAM]
5388 System Initialization:
5389 ----------------------
5391 In the reset configuration, U-Boot starts at the reset entry point
5392 (on most PowerPC systems at address 0x00000100). Because of the reset
5393 configuration for CS0# this is a mirror of the onboard Flash memory.
5394 To be able to re-map memory U-Boot then jumps to its link address.
5395 To be able to implement the initialization code in C, a (small!)
5396 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5397 which provide such a feature like MPC8xx or MPC8260), or in a locked
5398 part of the data cache. After that, U-Boot initializes the CPU core,
5399 the caches and the SIU.
5401 Next, all (potentially) available memory banks are mapped using a
5402 preliminary mapping. For example, we put them on 512 MB boundaries
5403 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5404 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5405 programmed for SDRAM access. Using the temporary configuration, a
5406 simple memory test is run that determines the size of the SDRAM
5409 When there is more than one SDRAM bank, and the banks are of
5410 different size, the largest is mapped first. For equal size, the first
5411 bank (CS2#) is mapped first. The first mapping is always for address
5412 0x00000000, with any additional banks following immediately to create
5413 contiguous memory starting from 0.
5415 Then, the monitor installs itself at the upper end of the SDRAM area
5416 and allocates memory for use by malloc() and for the global Board
5417 Info data; also, the exception vector code is copied to the low RAM
5418 pages, and the final stack is set up.
5420 Only after this relocation will you have a "normal" C environment;
5421 until that you are restricted in several ways, mostly because you are
5422 running from ROM, and because the code will have to be relocated to a
5426 U-Boot Porting Guide:
5427 ----------------------
5429 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5433 int main(int argc, char *argv[])
5435 sighandler_t no_more_time;
5437 signal(SIGALRM, no_more_time);
5438 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5440 if (available_money > available_manpower) {
5441 Pay consultant to port U-Boot;
5445 Download latest U-Boot source;
5447 Subscribe to u-boot mailing list;
5450 email("Hi, I am new to U-Boot, how do I get started?");
5453 Read the README file in the top level directory;
5454 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5455 Read applicable doc/*.README;
5456 Read the source, Luke;
5457 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5460 if (available_money > toLocalCurrency ($2500))
5463 Add a lot of aggravation and time;
5465 if (a similar board exists) { /* hopefully... */
5466 cp -a board/<similar> board/<myboard>
5467 cp include/configs/<similar>.h include/configs/<myboard>.h
5469 Create your own board support subdirectory;
5470 Create your own board include/configs/<myboard>.h file;
5472 Edit new board/<myboard> files
5473 Edit new include/configs/<myboard>.h
5478 Add / modify source code;
5482 email("Hi, I am having problems...");
5484 Send patch file to the U-Boot email list;
5485 if (reasonable critiques)
5486 Incorporate improvements from email list code review;
5488 Defend code as written;
5494 void no_more_time (int sig)
5503 All contributions to U-Boot should conform to the Linux kernel
5504 coding style; see the file "Documentation/CodingStyle" and the script
5505 "scripts/Lindent" in your Linux kernel source directory.
5507 Source files originating from a different project (for example the
5508 MTD subsystem) are generally exempt from these guidelines and are not
5509 reformated to ease subsequent migration to newer versions of those
5512 Please note that U-Boot is implemented in C (and to some small parts in
5513 Assembler); no C++ is used, so please do not use C++ style comments (//)
5516 Please also stick to the following formatting rules:
5517 - remove any trailing white space
5518 - use TAB characters for indentation and vertical alignment, not spaces
5519 - make sure NOT to use DOS '\r\n' line feeds
5520 - do not add more than 2 consecutive empty lines to source files
5521 - do not add trailing empty lines to source files
5523 Submissions which do not conform to the standards may be returned
5524 with a request to reformat the changes.
5530 Since the number of patches for U-Boot is growing, we need to
5531 establish some rules. Submissions which do not conform to these rules
5532 may be rejected, even when they contain important and valuable stuff.
5534 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5536 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5537 see http://lists.denx.de/mailman/listinfo/u-boot
5539 When you send a patch, please include the following information with
5542 * For bug fixes: a description of the bug and how your patch fixes
5543 this bug. Please try to include a way of demonstrating that the
5544 patch actually fixes something.
5546 * For new features: a description of the feature and your
5549 * A CHANGELOG entry as plaintext (separate from the patch)
5551 * For major contributions, your entry to the CREDITS file
5553 * When you add support for a new board, don't forget to add this
5554 board to the MAINTAINERS file, too.
5556 * If your patch adds new configuration options, don't forget to
5557 document these in the README file.
5559 * The patch itself. If you are using git (which is *strongly*
5560 recommended) you can easily generate the patch using the
5561 "git format-patch". If you then use "git send-email" to send it to
5562 the U-Boot mailing list, you will avoid most of the common problems
5563 with some other mail clients.
5565 If you cannot use git, use "diff -purN OLD NEW". If your version of
5566 diff does not support these options, then get the latest version of
5569 The current directory when running this command shall be the parent
5570 directory of the U-Boot source tree (i. e. please make sure that
5571 your patch includes sufficient directory information for the
5574 We prefer patches as plain text. MIME attachments are discouraged,
5575 and compressed attachments must not be used.
5577 * If one logical set of modifications affects or creates several
5578 files, all these changes shall be submitted in a SINGLE patch file.
5580 * Changesets that contain different, unrelated modifications shall be
5581 submitted as SEPARATE patches, one patch per changeset.
5586 * Before sending the patch, run the MAKEALL script on your patched
5587 source tree and make sure that no errors or warnings are reported
5588 for any of the boards.
5590 * Keep your modifications to the necessary minimum: A patch
5591 containing several unrelated changes or arbitrary reformats will be
5592 returned with a request to re-formatting / split it.
5594 * If you modify existing code, make sure that your new code does not
5595 add to the memory footprint of the code ;-) Small is beautiful!
5596 When adding new features, these should compile conditionally only
5597 (using #ifdef), and the resulting code with the new feature
5598 disabled must not need more memory than the old code without your
5601 * Remember that there is a size limit of 100 kB per message on the
5602 u-boot mailing list. Bigger patches will be moderated. If they are
5603 reasonable and not too big, they will be acknowledged. But patches
5604 bigger than the size limit should be avoided.
projects / u-boot / blob