2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /ixp Files specific to Intel XScale IXP CPUs
145 /pxa Files specific to Intel XScale PXA CPUs
146 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
147 /lib Architecture specific library files
148 /avr32 Files generic to AVR32 architecture
149 /cpu CPU specific files
150 /lib Architecture specific library files
151 /blackfin Files generic to Analog Devices Blackfin architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /m68k Files generic to m68k architecture
155 /cpu CPU specific files
156 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 /lib Architecture specific library files
162 /microblaze Files generic to microblaze architecture
163 /cpu CPU specific files
164 /lib Architecture specific library files
165 /mips Files generic to MIPS architecture
166 /cpu CPU specific files
167 /mips32 Files specific to MIPS32 CPUs
168 /xburst Files specific to Ingenic XBurst CPUs
169 /lib Architecture specific library files
170 /nds32 Files generic to NDS32 architecture
171 /cpu CPU specific files
172 /n1213 Files specific to Andes Technology N1213 CPUs
173 /lib Architecture specific library files
174 /nios2 Files generic to Altera NIOS2 architecture
175 /cpu CPU specific files
176 /lib Architecture specific library files
177 /openrisc Files generic to OpenRISC architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /powerpc Files generic to PowerPC architecture
181 /cpu CPU specific files
182 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
183 /mpc5xx Files specific to Freescale MPC5xx CPUs
184 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
185 /mpc8xx Files specific to Freescale MPC8xx CPUs
186 /mpc824x Files specific to Freescale MPC824x CPUs
187 /mpc8260 Files specific to Freescale MPC8260 CPUs
188 /mpc85xx Files specific to Freescale MPC85xx CPUs
189 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
190 /lib Architecture specific library files
191 /sh Files generic to SH architecture
192 /cpu CPU specific files
193 /sh2 Files specific to sh2 CPUs
194 /sh3 Files specific to sh3 CPUs
195 /sh4 Files specific to sh4 CPUs
196 /lib Architecture specific library files
197 /sparc Files generic to SPARC architecture
198 /cpu CPU specific files
199 /leon2 Files specific to Gaisler LEON2 SPARC CPU
200 /leon3 Files specific to Gaisler LEON3 SPARC CPU
201 /lib Architecture specific library files
202 /x86 Files generic to x86 architecture
203 /cpu CPU specific files
204 /lib Architecture specific library files
205 /api Machine/arch independent API for external apps
206 /board Board dependent files
207 /common Misc architecture independent functions
208 /disk Code for disk drive partition handling
209 /doc Documentation (don't expect too much)
210 /drivers Commonly used device drivers
211 /dts Contains Makefile for building internal U-Boot fdt.
212 /examples Example code for standalone applications, etc.
213 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
214 /include Header Files
215 /lib Files generic to all architectures
216 /libfdt Library files to support flattened device trees
217 /lzma Library files to support LZMA decompression
218 /lzo Library files to support LZO decompression
220 /post Power On Self Test
221 /spl Secondary Program Loader framework
222 /tools Tools to build S-Record or U-Boot images, etc.
224 Software Configuration:
225 =======================
227 Configuration is usually done using C preprocessor defines; the
228 rationale behind that is to avoid dead code whenever possible.
230 There are two classes of configuration variables:
232 * Configuration _OPTIONS_:
233 These are selectable by the user and have names beginning with
236 * Configuration _SETTINGS_:
237 These depend on the hardware etc. and should not be meddled with if
238 you don't know what you're doing; they have names beginning with
241 Later we will add a configuration tool - probably similar to or even
242 identical to what's used for the Linux kernel. Right now, we have to
243 do the configuration by hand, which means creating some symbolic
244 links and editing some configuration files. We use the TQM8xxL boards
248 Selection of Processor Architecture and Board Type:
249 ---------------------------------------------------
251 For all supported boards there are ready-to-use default
252 configurations available; just type "make <board_name>_config".
254 Example: For a TQM823L module type:
259 For the Cogent platform, you need to specify the CPU type as well;
260 e.g. "make cogent_mpc8xx_config". And also configure the cogent
261 directory according to the instructions in cogent/README.
264 Configuration Options:
265 ----------------------
267 Configuration depends on the combination of board and CPU type; all
268 such information is kept in a configuration file
269 "include/configs/<board_name>.h".
271 Example: For a TQM823L module, all configuration settings are in
272 "include/configs/TQM823L.h".
275 Many of the options are named exactly as the corresponding Linux
276 kernel configuration options. The intention is to make it easier to
277 build a config tool - later.
280 The following options need to be configured:
282 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
284 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
286 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
287 Define exactly one, e.g. CONFIG_ATSTK1002
289 - CPU Module Type: (if CONFIG_COGENT is defined)
290 Define exactly one of
292 --- FIXME --- not tested yet:
293 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
294 CONFIG_CMA287_23, CONFIG_CMA287_50
296 - Motherboard Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
298 CONFIG_CMA101, CONFIG_CMA102
300 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
301 Define one or more of
304 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
305 Define one or more of
306 CONFIG_LCD_HEARTBEAT - update a character position on
307 the LCD display every second with
310 - Board flavour: (if CONFIG_MPC8260ADS is defined)
313 CONFIG_SYS_8260ADS - original MPC8260ADS
314 CONFIG_SYS_8266ADS - MPC8266ADS
315 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
316 CONFIG_SYS_8272ADS - MPC8272ADS
318 - Marvell Family Member
319 CONFIG_SYS_MVFS - define it if you want to enable
320 multiple fs option at one time
321 for marvell soc family
323 - MPC824X Family Member (if CONFIG_MPC824X is defined)
324 Define exactly one of
325 CONFIG_MPC8240, CONFIG_MPC8245
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 requred during NOR boot.
406 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
408 This is the value to write into CCSR offset 0x18600
409 according to the A004510 workaround.
411 CONFIG_SYS_FSL_DSP_DDR_ADDR
412 This value denotes start offset of DDR memory which is
413 connected exclusively to the DSP cores.
415 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
416 This value denotes start offset of M2 memory
417 which is directly connected to the DSP core.
419 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
420 This value denotes start offset of M3 memory which is directly
421 connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
424 This value denotes start offset of DSP CCSR space.
426 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
427 Single Source Clock is clocking mode present in some of FSL SoC's.
428 In this mode, a single differential clock is used to supply
429 clocks to the sysclock, ddrclock and usbclock.
431 - Generic CPU options:
432 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
434 Defines the endianess of the CPU. Implementation of those
435 values is arch specific.
438 Freescale DDR driver in use. This type of DDR controller is
439 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
442 CONFIG_SYS_FSL_DDR_ADDR
443 Freescale DDR memory-mapped register base.
445 CONFIG_SYS_FSL_DDR_EMU
446 Specify emulator support for DDR. Some DDR features such as
447 deskew training are not available.
449 CONFIG_SYS_FSL_DDRC_GEN1
450 Freescale DDR1 controller.
452 CONFIG_SYS_FSL_DDRC_GEN2
453 Freescale DDR2 controller.
455 CONFIG_SYS_FSL_DDRC_GEN3
456 Freescale DDR3 controller.
458 CONFIG_SYS_FSL_DDRC_ARM_GEN3
459 Freescale DDR3 controller for ARM-based SoCs.
462 Board config to use DDR1. It can be enabled for SoCs with
463 Freescale DDR1 or DDR2 controllers, depending on the board
467 Board config to use DDR2. It can be eanbeld for SoCs with
468 Freescale DDR2 or DDR3 controllers, depending on the board
472 Board config to use DDR3. It can be enabled for SoCs with
473 Freescale DDR3 controllers.
475 CONFIG_SYS_FSL_IFC_BE
476 Defines the IFC controller register space as Big Endian
478 CONFIG_SYS_FSL_IFC_LE
479 Defines the IFC controller register space as Little Endian
481 CONFIG_SYS_FSL_PBL_PBI
482 It enables addition of RCW (Power on reset configuration) in built image.
483 Please refer doc/README.pblimage for more details
485 CONFIG_SYS_FSL_PBL_RCW
486 It adds PBI(pre-boot instructions) commands in u-boot build image.
487 PBI commands can be used to configure SoC before it starts the execution.
488 Please refer doc/README.pblimage for more details
490 - Intel Monahans options:
491 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
493 Defines the Monahans run mode to oscillator
494 ratio. Valid values are 8, 16, 24, 31. The core
495 frequency is this value multiplied by 13 MHz.
497 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
499 Defines the Monahans turbo mode to oscillator
500 ratio. Valid values are 1 (default if undefined) and
501 2. The core frequency as calculated above is multiplied
505 CONFIG_SYS_INIT_SP_OFFSET
507 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
508 pointer. This is needed for the temporary stack before
511 CONFIG_SYS_MIPS_CACHE_MODE
513 Cache operation mode for the MIPS CPU.
514 See also arch/mips/include/asm/mipsregs.h.
516 CONF_CM_CACHABLE_NO_WA
519 CONF_CM_CACHABLE_NONCOHERENT
523 CONF_CM_CACHABLE_ACCELERATED
525 CONFIG_SYS_XWAY_EBU_BOOTCFG
527 Special option for Lantiq XWAY SoCs for booting from NOR flash.
528 See also arch/mips/cpu/mips32/start.S.
530 CONFIG_XWAY_SWAP_BYTES
532 Enable compilation of tools/xway-swap-bytes needed for Lantiq
533 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
534 be swapped if a flash programmer is used.
537 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
539 Select high exception vectors of the ARM core, e.g., do not
540 clear the V bit of the c1 register of CP15.
542 CONFIG_SYS_THUMB_BUILD
544 Use this flag to build U-Boot using the Thumb instruction
545 set for ARM architectures. Thumb instruction set provides
546 better code density. For ARM architectures that support
547 Thumb2 this flag will result in Thumb2 code generated by
550 CONFIG_ARM_ERRATA_716044
551 CONFIG_ARM_ERRATA_742230
552 CONFIG_ARM_ERRATA_743622
553 CONFIG_ARM_ERRATA_751472
555 If set, the workarounds for these ARM errata are applied early
556 during U-Boot startup. Note that these options force the
557 workarounds to be applied; no CPU-type/version detection
558 exists, unlike the similar options in the Linux kernel. Do not
559 set these options unless they apply!
564 The frequency of the timer returned by get_timer().
565 get_timer() must operate in milliseconds and this CONFIG
566 option must be set to 1000.
568 - Linux Kernel Interface:
571 U-Boot stores all clock information in Hz
572 internally. For binary compatibility with older Linux
573 kernels (which expect the clocks passed in the
574 bd_info data to be in MHz) the environment variable
575 "clocks_in_mhz" can be defined so that U-Boot
576 converts clock data to MHZ before passing it to the
578 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
579 "clocks_in_mhz=1" is automatically included in the
582 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
584 When transferring memsize parameter to linux, some versions
585 expect it to be in bytes, others in MB.
586 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
590 New kernel versions are expecting firmware settings to be
591 passed using flattened device trees (based on open firmware
595 * New libfdt-based support
596 * Adds the "fdt" command
597 * The bootm command automatically updates the fdt
599 OF_CPU - The proper name of the cpus node (only required for
600 MPC512X and MPC5xxx based boards).
601 OF_SOC - The proper name of the soc node (only required for
602 MPC512X and MPC5xxx based boards).
603 OF_TBCLK - The timebase frequency.
604 OF_STDOUT_PATH - The path to the console device
606 boards with QUICC Engines require OF_QE to set UCC MAC
609 CONFIG_OF_BOARD_SETUP
611 Board code has addition modification that it wants to make
612 to the flat device tree before handing it off to the kernel
616 This define fills in the correct boot CPU in the boot
617 param header, the default value is zero if undefined.
621 U-Boot can detect if an IDE device is present or not.
622 If not, and this new config option is activated, U-Boot
623 removes the ATA node from the DTS before booting Linux,
624 so the Linux IDE driver does not probe the device and
625 crash. This is needed for buggy hardware (uc101) where
626 no pull down resistor is connected to the signal IDE5V_DD7.
628 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
630 This setting is mandatory for all boards that have only one
631 machine type and must be used to specify the machine type
632 number as it appears in the ARM machine registry
633 (see http://www.arm.linux.org.uk/developer/machines/).
634 Only boards that have multiple machine types supported
635 in a single configuration file and the machine type is
636 runtime discoverable, do not have to use this setting.
638 - vxWorks boot parameters:
640 bootvx constructs a valid bootline using the following
641 environments variables: bootfile, ipaddr, serverip, hostname.
642 It loads the vxWorks image pointed bootfile.
644 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
645 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
646 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
647 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
649 CONFIG_SYS_VXWORKS_ADD_PARAMS
651 Add it at the end of the bootline. E.g "u=username pw=secret"
653 Note: If a "bootargs" environment is defined, it will overwride
654 the defaults discussed just above.
656 - Cache Configuration:
657 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
658 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
659 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
661 - Cache Configuration for ARM:
662 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
664 CONFIG_SYS_PL310_BASE - Physical base address of PL310
665 controller register space
670 Define this if you want support for Amba PrimeCell PL010 UARTs.
674 Define this if you want support for Amba PrimeCell PL011 UARTs.
678 If you have Amba PrimeCell PL011 UARTs, set this variable to
679 the clock speed of the UARTs.
683 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
684 define this to a list of base addresses for each (supported)
685 port. See e.g. include/configs/versatile.h
687 CONFIG_PL011_SERIAL_RLCR
689 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
690 have separate receive and transmit line control registers. Set
691 this variable to initialize the extra register.
693 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
695 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
696 boot loader that has already initialized the UART. Define this
697 variable to flush the UART at init time.
701 Depending on board, define exactly one serial port
702 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
703 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
704 console by defining CONFIG_8xx_CONS_NONE
706 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
707 port routines must be defined elsewhere
708 (i.e. serial_init(), serial_getc(), ...)
711 Enables console device for a color framebuffer. Needs following
712 defines (cf. smiLynxEM, i8042)
713 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
715 VIDEO_HW_RECTFILL graphic chip supports
718 VIDEO_HW_BITBLT graphic chip supports
719 bit-blit (cf. smiLynxEM)
720 VIDEO_VISIBLE_COLS visible pixel columns
722 VIDEO_VISIBLE_ROWS visible pixel rows
723 VIDEO_PIXEL_SIZE bytes per pixel
724 VIDEO_DATA_FORMAT graphic data format
725 (0-5, cf. cfb_console.c)
726 VIDEO_FB_ADRS framebuffer address
727 VIDEO_KBD_INIT_FCT keyboard int fct
728 (i.e. i8042_kbd_init())
729 VIDEO_TSTC_FCT test char fct
731 VIDEO_GETC_FCT get char fct
733 CONFIG_CONSOLE_CURSOR cursor drawing on/off
734 (requires blink timer
736 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
737 CONFIG_CONSOLE_TIME display time/date info in
739 (requires CONFIG_CMD_DATE)
740 CONFIG_VIDEO_LOGO display Linux logo in
742 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
743 linux_logo.h for logo.
744 Requires CONFIG_VIDEO_LOGO
745 CONFIG_CONSOLE_EXTRA_INFO
746 additional board info beside
749 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
750 a limited number of ANSI escape sequences (cursor control,
751 erase functions and limited graphics rendition control).
753 When CONFIG_CFB_CONSOLE is defined, video console is
754 default i/o. Serial console can be forced with
755 environment 'console=serial'.
757 When CONFIG_SILENT_CONSOLE is defined, all console
758 messages (by U-Boot and Linux!) can be silenced with
759 the "silent" environment variable. See
760 doc/README.silent for more information.
762 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
764 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
768 CONFIG_BAUDRATE - in bps
769 Select one of the baudrates listed in
770 CONFIG_SYS_BAUDRATE_TABLE, see below.
771 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
773 - Console Rx buffer length
774 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
775 the maximum receive buffer length for the SMC.
776 This option is actual only for 82xx and 8xx possible.
777 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
778 must be defined, to setup the maximum idle timeout for
781 - Pre-Console Buffer:
782 Prior to the console being initialised (i.e. serial UART
783 initialised etc) all console output is silently discarded.
784 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
785 buffer any console messages prior to the console being
786 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
787 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
788 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
789 bytes are output before the console is initialised, the
790 earlier bytes are discarded.
792 'Sane' compilers will generate smaller code if
793 CONFIG_PRE_CON_BUF_SZ is a power of 2
795 - Safe printf() functions
796 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
797 the printf() functions. These are defined in
798 include/vsprintf.h and include snprintf(), vsnprintf() and
799 so on. Code size increase is approximately 300-500 bytes.
800 If this option is not given then these functions will
801 silently discard their buffer size argument - this means
802 you are not getting any overflow checking in this case.
804 - Boot Delay: CONFIG_BOOTDELAY - in seconds
805 Delay before automatically booting the default image;
806 set to -1 to disable autoboot.
807 set to -2 to autoboot with no delay and not check for abort
808 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
810 See doc/README.autoboot for these options that
811 work with CONFIG_BOOTDELAY. None are required.
812 CONFIG_BOOT_RETRY_TIME
813 CONFIG_BOOT_RETRY_MIN
814 CONFIG_AUTOBOOT_KEYED
815 CONFIG_AUTOBOOT_PROMPT
816 CONFIG_AUTOBOOT_DELAY_STR
817 CONFIG_AUTOBOOT_STOP_STR
818 CONFIG_AUTOBOOT_DELAY_STR2
819 CONFIG_AUTOBOOT_STOP_STR2
820 CONFIG_ZERO_BOOTDELAY_CHECK
821 CONFIG_RESET_TO_RETRY
825 Only needed when CONFIG_BOOTDELAY is enabled;
826 define a command string that is automatically executed
827 when no character is read on the console interface
828 within "Boot Delay" after reset.
831 This can be used to pass arguments to the bootm
832 command. The value of CONFIG_BOOTARGS goes into the
833 environment value "bootargs".
835 CONFIG_RAMBOOT and CONFIG_NFSBOOT
836 The value of these goes into the environment as
837 "ramboot" and "nfsboot" respectively, and can be used
838 as a convenience, when switching between booting from
842 CONFIG_BOOTCOUNT_LIMIT
843 Implements a mechanism for detecting a repeating reboot
845 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
848 If no softreset save registers are found on the hardware
849 "bootcount" is stored in the environment. To prevent a
850 saveenv on all reboots, the environment variable
851 "upgrade_available" is used. If "upgrade_available" is
852 0, "bootcount" is always 0, if "upgrade_available" is
853 1 "bootcount" is incremented in the environment.
854 So the Userspace Applikation must set the "upgrade_available"
855 and "bootcount" variable to 0, if a boot was successfully.
860 When this option is #defined, the existence of the
861 environment variable "preboot" will be checked
862 immediately before starting the CONFIG_BOOTDELAY
863 countdown and/or running the auto-boot command resp.
864 entering interactive mode.
866 This feature is especially useful when "preboot" is
867 automatically generated or modified. For an example
868 see the LWMON board specific code: here "preboot" is
869 modified when the user holds down a certain
870 combination of keys on the (special) keyboard when
873 - Serial Download Echo Mode:
875 If defined to 1, all characters received during a
876 serial download (using the "loads" command) are
877 echoed back. This might be needed by some terminal
878 emulations (like "cu"), but may as well just take
879 time on others. This setting #define's the initial
880 value of the "loads_echo" environment variable.
882 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
884 Select one of the baudrates listed in
885 CONFIG_SYS_BAUDRATE_TABLE, see below.
888 Monitor commands can be included or excluded
889 from the build by using the #include files
890 <config_cmd_all.h> and #undef'ing unwanted
891 commands, or using <config_cmd_default.h>
892 and augmenting with additional #define's
895 The default command configuration includes all commands
896 except those marked below with a "*".
898 CONFIG_CMD_ASKENV * ask for env variable
899 CONFIG_CMD_BDI bdinfo
900 CONFIG_CMD_BEDBUG * Include BedBug Debugger
901 CONFIG_CMD_BMP * BMP support
902 CONFIG_CMD_BSP * Board specific commands
903 CONFIG_CMD_BOOTD bootd
904 CONFIG_CMD_CACHE * icache, dcache
905 CONFIG_CMD_CLK * clock command support
906 CONFIG_CMD_CONSOLE coninfo
907 CONFIG_CMD_CRC32 * crc32
908 CONFIG_CMD_DATE * support for RTC, date/time...
909 CONFIG_CMD_DHCP * DHCP support
910 CONFIG_CMD_DIAG * Diagnostics
911 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
912 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
913 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
914 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
915 CONFIG_CMD_DTT * Digital Therm and Thermostat
916 CONFIG_CMD_ECHO echo arguments
917 CONFIG_CMD_EDITENV edit env variable
918 CONFIG_CMD_EEPROM * EEPROM read/write support
919 CONFIG_CMD_ELF * bootelf, bootvx
920 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
921 CONFIG_CMD_ENV_FLAGS * display details about env flags
922 CONFIG_CMD_ENV_EXISTS * check existence of env variable
923 CONFIG_CMD_EXPORTENV * export the environment
924 CONFIG_CMD_EXT2 * ext2 command support
925 CONFIG_CMD_EXT4 * ext4 command support
926 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
927 that work for multiple fs types
928 CONFIG_CMD_SAVEENV saveenv
929 CONFIG_CMD_FDC * Floppy Disk Support
930 CONFIG_CMD_FAT * FAT command support
931 CONFIG_CMD_FDOS * Dos diskette Support
932 CONFIG_CMD_FLASH flinfo, erase, protect
933 CONFIG_CMD_FPGA FPGA device initialization support
934 CONFIG_CMD_FUSE * Device fuse support
935 CONFIG_CMD_GETTIME * Get time since boot
936 CONFIG_CMD_GO * the 'go' command (exec code)
937 CONFIG_CMD_GREPENV * search environment
938 CONFIG_CMD_HASH * calculate hash / digest
939 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
940 CONFIG_CMD_I2C * I2C serial bus support
941 CONFIG_CMD_IDE * IDE harddisk support
942 CONFIG_CMD_IMI iminfo
943 CONFIG_CMD_IMLS List all images found in NOR flash
944 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
945 CONFIG_CMD_IMMAP * IMMR dump support
946 CONFIG_CMD_IMPORTENV * import an environment
947 CONFIG_CMD_INI * import data from an ini file into the env
948 CONFIG_CMD_IRQ * irqinfo
949 CONFIG_CMD_ITEST Integer/string test of 2 values
950 CONFIG_CMD_JFFS2 * JFFS2 Support
951 CONFIG_CMD_KGDB * kgdb
952 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
953 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
955 CONFIG_CMD_LOADB loadb
956 CONFIG_CMD_LOADS loads
957 CONFIG_CMD_MD5SUM * print md5 message digest
958 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
959 CONFIG_CMD_MEMINFO * Display detailed memory information
960 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
962 CONFIG_CMD_MEMTEST * mtest
963 CONFIG_CMD_MISC Misc functions like sleep etc
964 CONFIG_CMD_MMC * MMC memory mapped support
965 CONFIG_CMD_MII * MII utility commands
966 CONFIG_CMD_MTDPARTS * MTD partition support
967 CONFIG_CMD_NAND * NAND support
968 CONFIG_CMD_NET bootp, tftpboot, rarpboot
969 CONFIG_CMD_NFS NFS support
970 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
971 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
972 CONFIG_CMD_PCI * pciinfo
973 CONFIG_CMD_PCMCIA * PCMCIA support
974 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
976 CONFIG_CMD_PORTIO * Port I/O
977 CONFIG_CMD_READ * Read raw data from partition
978 CONFIG_CMD_REGINFO * Register dump
979 CONFIG_CMD_RUN run command in env variable
980 CONFIG_CMD_SANDBOX * sb command to access sandbox features
981 CONFIG_CMD_SAVES * save S record dump
982 CONFIG_CMD_SCSI * SCSI Support
983 CONFIG_CMD_SDRAM * print SDRAM configuration information
984 (requires CONFIG_CMD_I2C)
985 CONFIG_CMD_SETGETDCR Support for DCR Register access
987 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
988 CONFIG_CMD_SHA1SUM * print sha1 memory digest
989 (requires CONFIG_CMD_MEMORY)
990 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
991 CONFIG_CMD_SOURCE "source" command Support
992 CONFIG_CMD_SPI * SPI serial bus support
993 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
994 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
995 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
996 CONFIG_CMD_TIMER * access to the system tick timer
997 CONFIG_CMD_USB * USB support
998 CONFIG_CMD_CDP * Cisco Discover Protocol support
999 CONFIG_CMD_MFSL * Microblaze FSL support
1000 CONFIG_CMD_XIMG Load part of Multi Image
1003 EXAMPLE: If you want all functions except of network
1004 support you can write:
1006 #include "config_cmd_all.h"
1007 #undef CONFIG_CMD_NET
1010 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1012 Note: Don't enable the "icache" and "dcache" commands
1013 (configuration option CONFIG_CMD_CACHE) unless you know
1014 what you (and your U-Boot users) are doing. Data
1015 cache cannot be enabled on systems like the 8xx or
1016 8260 (where accesses to the IMMR region must be
1017 uncached), and it cannot be disabled on all other
1018 systems where we (mis-) use the data cache to hold an
1019 initial stack and some data.
1022 XXX - this list needs to get updated!
1024 - Regular expression support:
1026 If this variable is defined, U-Boot is linked against
1027 the SLRE (Super Light Regular Expression) library,
1028 which adds regex support to some commands, as for
1029 example "env grep" and "setexpr".
1033 If this variable is defined, U-Boot will use a device tree
1034 to configure its devices, instead of relying on statically
1035 compiled #defines in the board file. This option is
1036 experimental and only available on a few boards. The device
1037 tree is available in the global data as gd->fdt_blob.
1039 U-Boot needs to get its device tree from somewhere. This can
1040 be done using one of the two options below:
1043 If this variable is defined, U-Boot will embed a device tree
1044 binary in its image. This device tree file should be in the
1045 board directory and called <soc>-<board>.dts. The binary file
1046 is then picked up in board_init_f() and made available through
1047 the global data structure as gd->blob.
1050 If this variable is defined, U-Boot will build a device tree
1051 binary. It will be called u-boot.dtb. Architecture-specific
1052 code will locate it at run-time. Generally this works by:
1054 cat u-boot.bin u-boot.dtb >image.bin
1056 and in fact, U-Boot does this for you, creating a file called
1057 u-boot-dtb.bin which is useful in the common case. You can
1058 still use the individual files if you need something more
1063 If this variable is defined, it enables watchdog
1064 support for the SoC. There must be support in the SoC
1065 specific code for a watchdog. For the 8xx and 8260
1066 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1067 register. When supported for a specific SoC is
1068 available, then no further board specific code should
1069 be needed to use it.
1072 When using a watchdog circuitry external to the used
1073 SoC, then define this variable and provide board
1074 specific code for the "hw_watchdog_reset" function.
1077 CONFIG_VERSION_VARIABLE
1078 If this variable is defined, an environment variable
1079 named "ver" is created by U-Boot showing the U-Boot
1080 version as printed by the "version" command.
1081 Any change to this variable will be reverted at the
1086 When CONFIG_CMD_DATE is selected, the type of the RTC
1087 has to be selected, too. Define exactly one of the
1090 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1091 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1092 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1093 CONFIG_RTC_MC146818 - use MC146818 RTC
1094 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1095 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1096 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1097 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1098 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1099 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1100 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1101 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1104 Note that if the RTC uses I2C, then the I2C interface
1105 must also be configured. See I2C Support, below.
1108 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1110 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1111 chip-ngpio pairs that tell the PCA953X driver the number of
1112 pins supported by a particular chip.
1114 Note that if the GPIO device uses I2C, then the I2C interface
1115 must also be configured. See I2C Support, below.
1117 - Timestamp Support:
1119 When CONFIG_TIMESTAMP is selected, the timestamp
1120 (date and time) of an image is printed by image
1121 commands like bootm or iminfo. This option is
1122 automatically enabled when you select CONFIG_CMD_DATE .
1124 - Partition Labels (disklabels) Supported:
1125 Zero or more of the following:
1126 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1127 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1128 Intel architecture, USB sticks, etc.
1129 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1130 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1131 bootloader. Note 2TB partition limit; see
1133 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1135 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1136 CONFIG_CMD_SCSI) you must configure support for at
1137 least one non-MTD partition type as well.
1140 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1141 board configurations files but used nowhere!
1143 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1144 be performed by calling the function
1145 ide_set_reset(int reset)
1146 which has to be defined in a board specific file
1151 Set this to enable ATAPI support.
1156 Set this to enable support for disks larger than 137GB
1157 Also look at CONFIG_SYS_64BIT_LBA.
1158 Whithout these , LBA48 support uses 32bit variables and will 'only'
1159 support disks up to 2.1TB.
1161 CONFIG_SYS_64BIT_LBA:
1162 When enabled, makes the IDE subsystem use 64bit sector addresses.
1166 At the moment only there is only support for the
1167 SYM53C8XX SCSI controller; define
1168 CONFIG_SCSI_SYM53C8XX to enable it.
1170 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1171 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1172 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1173 maximum numbers of LUNs, SCSI ID's and target
1175 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1177 The environment variable 'scsidevs' is set to the number of
1178 SCSI devices found during the last scan.
1180 - NETWORK Support (PCI):
1182 Support for Intel 8254x/8257x gigabit chips.
1185 Utility code for direct access to the SPI bus on Intel 8257x.
1186 This does not do anything useful unless you set at least one
1187 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1189 CONFIG_E1000_SPI_GENERIC
1190 Allow generic access to the SPI bus on the Intel 8257x, for
1191 example with the "sspi" command.
1194 Management command for E1000 devices. When used on devices
1195 with SPI support you can reprogram the EEPROM from U-Boot.
1197 CONFIG_E1000_FALLBACK_MAC
1198 default MAC for empty EEPROM after production.
1201 Support for Intel 82557/82559/82559ER chips.
1202 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1203 write routine for first time initialisation.
1206 Support for Digital 2114x chips.
1207 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1208 modem chip initialisation (KS8761/QS6611).
1211 Support for National dp83815 chips.
1214 Support for National dp8382[01] gigabit chips.
1216 - NETWORK Support (other):
1218 CONFIG_DRIVER_AT91EMAC
1219 Support for AT91RM9200 EMAC.
1222 Define this to use reduced MII inteface
1224 CONFIG_DRIVER_AT91EMAC_QUIET
1225 If this defined, the driver is quiet.
1226 The driver doen't show link status messages.
1228 CONFIG_CALXEDA_XGMAC
1229 Support for the Calxeda XGMAC device
1232 Support for SMSC's LAN91C96 chips.
1234 CONFIG_LAN91C96_BASE
1235 Define this to hold the physical address
1236 of the LAN91C96's I/O space
1238 CONFIG_LAN91C96_USE_32_BIT
1239 Define this to enable 32 bit addressing
1242 Support for SMSC's LAN91C111 chip
1244 CONFIG_SMC91111_BASE
1245 Define this to hold the physical address
1246 of the device (I/O space)
1248 CONFIG_SMC_USE_32_BIT
1249 Define this if data bus is 32 bits
1251 CONFIG_SMC_USE_IOFUNCS
1252 Define this to use i/o functions instead of macros
1253 (some hardware wont work with macros)
1255 CONFIG_DRIVER_TI_EMAC
1256 Support for davinci emac
1258 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1259 Define this if you have more then 3 PHYs.
1262 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1264 CONFIG_FTGMAC100_EGIGA
1265 Define this to use GE link update with gigabit PHY.
1266 Define this if FTGMAC100 is connected to gigabit PHY.
1267 If your system has 10/100 PHY only, it might not occur
1268 wrong behavior. Because PHY usually return timeout or
1269 useless data when polling gigabit status and gigabit
1270 control registers. This behavior won't affect the
1271 correctnessof 10/100 link speed update.
1274 Support for SMSC's LAN911x and LAN921x chips
1277 Define this to hold the physical address
1278 of the device (I/O space)
1280 CONFIG_SMC911X_32_BIT
1281 Define this if data bus is 32 bits
1283 CONFIG_SMC911X_16_BIT
1284 Define this if data bus is 16 bits. If your processor
1285 automatically converts one 32 bit word to two 16 bit
1286 words you may also try CONFIG_SMC911X_32_BIT.
1289 Support for Renesas on-chip Ethernet controller
1291 CONFIG_SH_ETHER_USE_PORT
1292 Define the number of ports to be used
1294 CONFIG_SH_ETHER_PHY_ADDR
1295 Define the ETH PHY's address
1297 CONFIG_SH_ETHER_CACHE_WRITEBACK
1298 If this option is set, the driver enables cache flush.
1302 Support TPM devices.
1305 Support for i2c bus TPM devices. Only one device
1306 per system is supported at this time.
1308 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1309 Define the the i2c bus number for the TPM device
1311 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1312 Define the TPM's address on the i2c bus
1314 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1315 Define the burst count bytes upper limit
1317 CONFIG_TPM_ATMEL_TWI
1318 Support for Atmel TWI TPM device. Requires I2C support.
1321 Support for generic parallel port TPM devices. Only one device
1322 per system is supported at this time.
1324 CONFIG_TPM_TIS_BASE_ADDRESS
1325 Base address where the generic TPM device is mapped
1326 to. Contemporary x86 systems usually map it at
1330 Add tpm monitor functions.
1331 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1332 provides monitor access to authorized functions.
1335 Define this to enable the TPM support library which provides
1336 functional interfaces to some TPM commands.
1337 Requires support for a TPM device.
1339 CONFIG_TPM_AUTH_SESSIONS
1340 Define this to enable authorized functions in the TPM library.
1341 Requires CONFIG_TPM and CONFIG_SHA1.
1344 At the moment only the UHCI host controller is
1345 supported (PIP405, MIP405, MPC5200); define
1346 CONFIG_USB_UHCI to enable it.
1347 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1348 and define CONFIG_USB_STORAGE to enable the USB
1351 Supported are USB Keyboards and USB Floppy drives
1353 MPC5200 USB requires additional defines:
1355 for 528 MHz Clock: 0x0001bbbb
1359 for differential drivers: 0x00001000
1360 for single ended drivers: 0x00005000
1361 for differential drivers on PSC3: 0x00000100
1362 for single ended drivers on PSC3: 0x00004100
1363 CONFIG_SYS_USB_EVENT_POLL
1364 May be defined to allow interrupt polling
1365 instead of using asynchronous interrupts
1367 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1368 txfilltuning field in the EHCI controller on reset.
1370 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1371 interval for usb hub power-on delay.(minimum 100msec)
1374 Define the below if you wish to use the USB console.
1375 Once firmware is rebuilt from a serial console issue the
1376 command "setenv stdin usbtty; setenv stdout usbtty" and
1377 attach your USB cable. The Unix command "dmesg" should print
1378 it has found a new device. The environment variable usbtty
1379 can be set to gserial or cdc_acm to enable your device to
1380 appear to a USB host as a Linux gserial device or a
1381 Common Device Class Abstract Control Model serial device.
1382 If you select usbtty = gserial you should be able to enumerate
1384 # modprobe usbserial vendor=0xVendorID product=0xProductID
1385 else if using cdc_acm, simply setting the environment
1386 variable usbtty to be cdc_acm should suffice. The following
1387 might be defined in YourBoardName.h
1390 Define this to build a UDC device
1393 Define this to have a tty type of device available to
1394 talk to the UDC device
1397 Define this to enable the high speed support for usb
1398 device and usbtty. If this feature is enabled, a routine
1399 int is_usbd_high_speed(void)
1400 also needs to be defined by the driver to dynamically poll
1401 whether the enumeration has succeded at high speed or full
1404 CONFIG_SYS_CONSOLE_IS_IN_ENV
1405 Define this if you want stdin, stdout &/or stderr to
1409 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1410 Derive USB clock from external clock "blah"
1411 - CONFIG_SYS_USB_EXTC_CLK 0x02
1413 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1414 Derive USB clock from brgclk
1415 - CONFIG_SYS_USB_BRG_CLK 0x04
1417 If you have a USB-IF assigned VendorID then you may wish to
1418 define your own vendor specific values either in BoardName.h
1419 or directly in usbd_vendor_info.h. If you don't define
1420 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1421 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1422 should pretend to be a Linux device to it's target host.
1424 CONFIG_USBD_MANUFACTURER
1425 Define this string as the name of your company for
1426 - CONFIG_USBD_MANUFACTURER "my company"
1428 CONFIG_USBD_PRODUCT_NAME
1429 Define this string as the name of your product
1430 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1432 CONFIG_USBD_VENDORID
1433 Define this as your assigned Vendor ID from the USB
1434 Implementors Forum. This *must* be a genuine Vendor ID
1435 to avoid polluting the USB namespace.
1436 - CONFIG_USBD_VENDORID 0xFFFF
1438 CONFIG_USBD_PRODUCTID
1439 Define this as the unique Product ID
1441 - CONFIG_USBD_PRODUCTID 0xFFFF
1443 Some USB device drivers may need to check USB cable attachment.
1444 In this case you can enable following config in BoardName.h:
1445 CONFIG_USB_CABLE_CHECK
1446 This enables function definition:
1447 - usb_cable_connected() in include/usb.h
1448 Implementation of this function is board-specific.
1450 - ULPI Layer Support:
1451 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1452 the generic ULPI layer. The generic layer accesses the ULPI PHY
1453 via the platform viewport, so you need both the genric layer and
1454 the viewport enabled. Currently only Chipidea/ARC based
1455 viewport is supported.
1456 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1457 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1458 If your ULPI phy needs a different reference clock than the
1459 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1460 the appropriate value in Hz.
1463 The MMC controller on the Intel PXA is supported. To
1464 enable this define CONFIG_MMC. The MMC can be
1465 accessed from the boot prompt by mapping the device
1466 to physical memory similar to flash. Command line is
1467 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1468 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1471 Support for Renesas on-chip MMCIF controller
1473 CONFIG_SH_MMCIF_ADDR
1474 Define the base address of MMCIF registers
1477 Define the clock frequency for MMCIF
1479 - USB Device Firmware Update (DFU) class support:
1481 This enables the USB portion of the DFU USB class
1484 This enables the command "dfu" which is used to have
1485 U-Boot create a DFU class device via USB. This command
1486 requires that the "dfu_alt_info" environment variable be
1487 set and define the alt settings to expose to the host.
1490 This enables support for exposing (e)MMC devices via DFU.
1493 This enables support for exposing NAND devices via DFU.
1496 This enables support for exposing RAM via DFU.
1497 Note: DFU spec refer to non-volatile memory usage, but
1498 allow usages beyond the scope of spec - here RAM usage,
1499 one that would help mostly the developer.
1501 CONFIG_SYS_DFU_DATA_BUF_SIZE
1502 Dfu transfer uses a buffer before writing data to the
1503 raw storage device. Make the size (in bytes) of this buffer
1504 configurable. The size of this buffer is also configurable
1505 through the "dfu_bufsiz" environment variable.
1507 CONFIG_SYS_DFU_MAX_FILE_SIZE
1508 When updating files rather than the raw storage device,
1509 we use a static buffer to copy the file into and then write
1510 the buffer once we've been given the whole file. Define
1511 this to the maximum filesize (in bytes) for the buffer.
1512 Default is 4 MiB if undefined.
1514 - Journaling Flash filesystem support:
1515 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1516 CONFIG_JFFS2_NAND_DEV
1517 Define these for a default partition on a NAND device
1519 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1520 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1521 Define these for a default partition on a NOR device
1523 CONFIG_SYS_JFFS_CUSTOM_PART
1524 Define this to create an own partition. You have to provide a
1525 function struct part_info* jffs2_part_info(int part_num)
1527 If you define only one JFFS2 partition you may also want to
1528 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1529 to disable the command chpart. This is the default when you
1530 have not defined a custom partition
1532 - FAT(File Allocation Table) filesystem write function support:
1535 Define this to enable support for saving memory data as a
1536 file in FAT formatted partition.
1538 This will also enable the command "fatwrite" enabling the
1539 user to write files to FAT.
1541 CBFS (Coreboot Filesystem) support
1544 Define this to enable support for reading from a Coreboot
1545 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1551 Define this to enable standard (PC-Style) keyboard
1555 Standard PC keyboard driver with US (is default) and
1556 GERMAN key layout (switch via environment 'keymap=de') support.
1557 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1558 for cfb_console. Supports cursor blinking.
1561 Enables a Chrome OS keyboard using the CROS_EC interface.
1562 This uses CROS_EC to communicate with a second microcontroller
1563 which provides key scans on request.
1568 Define this to enable video support (for output to
1571 CONFIG_VIDEO_CT69000
1573 Enable Chips & Technologies 69000 Video chip
1575 CONFIG_VIDEO_SMI_LYNXEM
1576 Enable Silicon Motion SMI 712/710/810 Video chip. The
1577 video output is selected via environment 'videoout'
1578 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1581 For the CT69000 and SMI_LYNXEM drivers, videomode is
1582 selected via environment 'videomode'. Two different ways
1584 - "videomode=num" 'num' is a standard LiLo mode numbers.
1585 Following standard modes are supported (* is default):
1587 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1588 -------------+---------------------------------------------
1589 8 bits | 0x301* 0x303 0x305 0x161 0x307
1590 15 bits | 0x310 0x313 0x316 0x162 0x319
1591 16 bits | 0x311 0x314 0x317 0x163 0x31A
1592 24 bits | 0x312 0x315 0x318 ? 0x31B
1593 -------------+---------------------------------------------
1594 (i.e. setenv videomode 317; saveenv; reset;)
1596 - "videomode=bootargs" all the video parameters are parsed
1597 from the bootargs. (See drivers/video/videomodes.c)
1600 CONFIG_VIDEO_SED13806
1601 Enable Epson SED13806 driver. This driver supports 8bpp
1602 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1603 or CONFIG_VIDEO_SED13806_16BPP
1606 Enable the Freescale DIU video driver. Reference boards for
1607 SOCs that have a DIU should define this macro to enable DIU
1608 support, and should also define these other macros:
1614 CONFIG_VIDEO_SW_CURSOR
1615 CONFIG_VGA_AS_SINGLE_DEVICE
1617 CONFIG_VIDEO_BMP_LOGO
1619 The DIU driver will look for the 'video-mode' environment
1620 variable, and if defined, enable the DIU as a console during
1621 boot. See the documentation file README.video for a
1622 description of this variable.
1626 Enable the VGA video / BIOS for x86. The alternative if you
1627 are using coreboot is to use the coreboot frame buffer
1634 Define this to enable a custom keyboard support.
1635 This simply calls drv_keyboard_init() which must be
1636 defined in your board-specific files.
1637 The only board using this so far is RBC823.
1639 - LCD Support: CONFIG_LCD
1641 Define this to enable LCD support (for output to LCD
1642 display); also select one of the supported displays
1643 by defining one of these:
1647 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1649 CONFIG_NEC_NL6448AC33:
1651 NEC NL6448AC33-18. Active, color, single scan.
1653 CONFIG_NEC_NL6448BC20
1655 NEC NL6448BC20-08. 6.5", 640x480.
1656 Active, color, single scan.
1658 CONFIG_NEC_NL6448BC33_54
1660 NEC NL6448BC33-54. 10.4", 640x480.
1661 Active, color, single scan.
1665 Sharp 320x240. Active, color, single scan.
1666 It isn't 16x9, and I am not sure what it is.
1668 CONFIG_SHARP_LQ64D341
1670 Sharp LQ64D341 display, 640x480.
1671 Active, color, single scan.
1675 HLD1045 display, 640x480.
1676 Active, color, single scan.
1680 Optrex CBL50840-2 NF-FW 99 22 M5
1682 Hitachi LMG6912RPFC-00T
1686 320x240. Black & white.
1688 Normally display is black on white background; define
1689 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1691 CONFIG_LCD_ALIGNMENT
1693 Normally the LCD is page-aligned (tyically 4KB). If this is
1694 defined then the LCD will be aligned to this value instead.
1695 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1696 here, since it is cheaper to change data cache settings on
1697 a per-section basis.
1699 CONFIG_CONSOLE_SCROLL_LINES
1701 When the console need to be scrolled, this is the number of
1702 lines to scroll by. It defaults to 1. Increasing this makes
1703 the console jump but can help speed up operation when scrolling
1708 Support drawing of RLE8-compressed bitmaps on the LCD.
1712 Enables an 'i2c edid' command which can read EDID
1713 information over I2C from an attached LCD display.
1715 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1717 If this option is set, the environment is checked for
1718 a variable "splashimage". If found, the usual display
1719 of logo, copyright and system information on the LCD
1720 is suppressed and the BMP image at the address
1721 specified in "splashimage" is loaded instead. The
1722 console is redirected to the "nulldev", too. This
1723 allows for a "silent" boot where a splash screen is
1724 loaded very quickly after power-on.
1726 CONFIG_SPLASHIMAGE_GUARD
1728 If this option is set, then U-Boot will prevent the environment
1729 variable "splashimage" from being set to a problematic address
1730 (see README.displaying-bmps and README.arm-unaligned-accesses).
1731 This option is useful for targets where, due to alignment
1732 restrictions, an improperly aligned BMP image will cause a data
1733 abort. If you think you will not have problems with unaligned
1734 accesses (for example because your toolchain prevents them)
1735 there is no need to set this option.
1737 CONFIG_SPLASH_SCREEN_ALIGN
1739 If this option is set the splash image can be freely positioned
1740 on the screen. Environment variable "splashpos" specifies the
1741 position as "x,y". If a positive number is given it is used as
1742 number of pixel from left/top. If a negative number is given it
1743 is used as number of pixel from right/bottom. You can also
1744 specify 'm' for centering the image.
1747 setenv splashpos m,m
1748 => image at center of screen
1750 setenv splashpos 30,20
1751 => image at x = 30 and y = 20
1753 setenv splashpos -10,m
1754 => vertically centered image
1755 at x = dspWidth - bmpWidth - 9
1757 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1759 If this option is set, additionally to standard BMP
1760 images, gzipped BMP images can be displayed via the
1761 splashscreen support or the bmp command.
1763 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1765 If this option is set, 8-bit RLE compressed BMP images
1766 can be displayed via the splashscreen support or the
1769 - Do compresssing for memory range:
1772 If this option is set, it would use zlib deflate method
1773 to compress the specified memory at its best effort.
1775 - Compression support:
1778 Enabled by default to support gzip compressed images.
1782 If this option is set, support for bzip2 compressed
1783 images is included. If not, only uncompressed and gzip
1784 compressed images are supported.
1786 NOTE: the bzip2 algorithm requires a lot of RAM, so
1787 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1792 If this option is set, support for lzma compressed
1795 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1796 requires an amount of dynamic memory that is given by the
1799 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1801 Where lc and lp stand for, respectively, Literal context bits
1802 and Literal pos bits.
1804 This value is upper-bounded by 14MB in the worst case. Anyway,
1805 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1806 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1807 a very small buffer.
1809 Use the lzmainfo tool to determinate the lc and lp values and
1810 then calculate the amount of needed dynamic memory (ensuring
1811 the appropriate CONFIG_SYS_MALLOC_LEN value).
1815 If this option is set, support for LZO compressed images
1821 The address of PHY on MII bus.
1823 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1825 The clock frequency of the MII bus
1829 If this option is set, support for speed/duplex
1830 detection of gigabit PHY is included.
1832 CONFIG_PHY_RESET_DELAY
1834 Some PHY like Intel LXT971A need extra delay after
1835 reset before any MII register access is possible.
1836 For such PHY, set this option to the usec delay
1837 required. (minimum 300usec for LXT971A)
1839 CONFIG_PHY_CMD_DELAY (ppc4xx)
1841 Some PHY like Intel LXT971A need extra delay after
1842 command issued before MII status register can be read
1852 Define a default value for Ethernet address to use
1853 for the respective Ethernet interface, in case this
1854 is not determined automatically.
1859 Define a default value for the IP address to use for
1860 the default Ethernet interface, in case this is not
1861 determined through e.g. bootp.
1862 (Environment variable "ipaddr")
1864 - Server IP address:
1867 Defines a default value for the IP address of a TFTP
1868 server to contact when using the "tftboot" command.
1869 (Environment variable "serverip")
1871 CONFIG_KEEP_SERVERADDR
1873 Keeps the server's MAC address, in the env 'serveraddr'
1874 for passing to bootargs (like Linux's netconsole option)
1876 - Gateway IP address:
1879 Defines a default value for the IP address of the
1880 default router where packets to other networks are
1882 (Environment variable "gatewayip")
1887 Defines a default value for the subnet mask (or
1888 routing prefix) which is used to determine if an IP
1889 address belongs to the local subnet or needs to be
1890 forwarded through a router.
1891 (Environment variable "netmask")
1893 - Multicast TFTP Mode:
1896 Defines whether you want to support multicast TFTP as per
1897 rfc-2090; for example to work with atftp. Lets lots of targets
1898 tftp down the same boot image concurrently. Note: the Ethernet
1899 driver in use must provide a function: mcast() to join/leave a
1902 - BOOTP Recovery Mode:
1903 CONFIG_BOOTP_RANDOM_DELAY
1905 If you have many targets in a network that try to
1906 boot using BOOTP, you may want to avoid that all
1907 systems send out BOOTP requests at precisely the same
1908 moment (which would happen for instance at recovery
1909 from a power failure, when all systems will try to
1910 boot, thus flooding the BOOTP server. Defining
1911 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1912 inserted before sending out BOOTP requests. The
1913 following delays are inserted then:
1915 1st BOOTP request: delay 0 ... 1 sec
1916 2nd BOOTP request: delay 0 ... 2 sec
1917 3rd BOOTP request: delay 0 ... 4 sec
1919 BOOTP requests: delay 0 ... 8 sec
1921 - DHCP Advanced Options:
1922 You can fine tune the DHCP functionality by defining
1923 CONFIG_BOOTP_* symbols:
1925 CONFIG_BOOTP_SUBNETMASK
1926 CONFIG_BOOTP_GATEWAY
1927 CONFIG_BOOTP_HOSTNAME
1928 CONFIG_BOOTP_NISDOMAIN
1929 CONFIG_BOOTP_BOOTPATH
1930 CONFIG_BOOTP_BOOTFILESIZE
1933 CONFIG_BOOTP_SEND_HOSTNAME
1934 CONFIG_BOOTP_NTPSERVER
1935 CONFIG_BOOTP_TIMEOFFSET
1936 CONFIG_BOOTP_VENDOREX
1937 CONFIG_BOOTP_MAY_FAIL
1939 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1940 environment variable, not the BOOTP server.
1942 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1943 after the configured retry count, the call will fail
1944 instead of starting over. This can be used to fail over
1945 to Link-local IP address configuration if the DHCP server
1948 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1949 serverip from a DHCP server, it is possible that more
1950 than one DNS serverip is offered to the client.
1951 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1952 serverip will be stored in the additional environment
1953 variable "dnsip2". The first DNS serverip is always
1954 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1957 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1958 to do a dynamic update of a DNS server. To do this, they
1959 need the hostname of the DHCP requester.
1960 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1961 of the "hostname" environment variable is passed as
1962 option 12 to the DHCP server.
1964 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1966 A 32bit value in microseconds for a delay between
1967 receiving a "DHCP Offer" and sending the "DHCP Request".
1968 This fixes a problem with certain DHCP servers that don't
1969 respond 100% of the time to a "DHCP request". E.g. On an
1970 AT91RM9200 processor running at 180MHz, this delay needed
1971 to be *at least* 15,000 usec before a Windows Server 2003
1972 DHCP server would reply 100% of the time. I recommend at
1973 least 50,000 usec to be safe. The alternative is to hope
1974 that one of the retries will be successful but note that
1975 the DHCP timeout and retry process takes a longer than
1978 - Link-local IP address negotiation:
1979 Negotiate with other link-local clients on the local network
1980 for an address that doesn't require explicit configuration.
1981 This is especially useful if a DHCP server cannot be guaranteed
1982 to exist in all environments that the device must operate.
1984 See doc/README.link-local for more information.
1987 CONFIG_CDP_DEVICE_ID
1989 The device id used in CDP trigger frames.
1991 CONFIG_CDP_DEVICE_ID_PREFIX
1993 A two character string which is prefixed to the MAC address
1998 A printf format string which contains the ascii name of
1999 the port. Normally is set to "eth%d" which sets
2000 eth0 for the first Ethernet, eth1 for the second etc.
2002 CONFIG_CDP_CAPABILITIES
2004 A 32bit integer which indicates the device capabilities;
2005 0x00000010 for a normal host which does not forwards.
2009 An ascii string containing the version of the software.
2013 An ascii string containing the name of the platform.
2017 A 32bit integer sent on the trigger.
2019 CONFIG_CDP_POWER_CONSUMPTION
2021 A 16bit integer containing the power consumption of the
2022 device in .1 of milliwatts.
2024 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2026 A byte containing the id of the VLAN.
2028 - Status LED: CONFIG_STATUS_LED
2030 Several configurations allow to display the current
2031 status using a LED. For instance, the LED will blink
2032 fast while running U-Boot code, stop blinking as
2033 soon as a reply to a BOOTP request was received, and
2034 start blinking slow once the Linux kernel is running
2035 (supported by a status LED driver in the Linux
2036 kernel). Defining CONFIG_STATUS_LED enables this
2042 The status LED can be connected to a GPIO pin.
2043 In such cases, the gpio_led driver can be used as a
2044 status LED backend implementation. Define CONFIG_GPIO_LED
2045 to include the gpio_led driver in the U-Boot binary.
2047 CONFIG_GPIO_LED_INVERTED_TABLE
2048 Some GPIO connected LEDs may have inverted polarity in which
2049 case the GPIO high value corresponds to LED off state and
2050 GPIO low value corresponds to LED on state.
2051 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2052 with a list of GPIO LEDs that have inverted polarity.
2054 - CAN Support: CONFIG_CAN_DRIVER
2056 Defining CONFIG_CAN_DRIVER enables CAN driver support
2057 on those systems that support this (optional)
2058 feature, like the TQM8xxL modules.
2060 - I2C Support: CONFIG_SYS_I2C
2062 This enable the NEW i2c subsystem, and will allow you to use
2063 i2c commands at the u-boot command line (as long as you set
2064 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2065 based realtime clock chips or other i2c devices. See
2066 common/cmd_i2c.c for a description of the command line
2069 ported i2c driver to the new framework:
2070 - drivers/i2c/soft_i2c.c:
2071 - activate first bus with CONFIG_SYS_I2C_SOFT define
2072 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2073 for defining speed and slave address
2074 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2075 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2076 for defining speed and slave address
2077 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2078 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2079 for defining speed and slave address
2080 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2081 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2082 for defining speed and slave address
2084 - drivers/i2c/fsl_i2c.c:
2085 - activate i2c driver with CONFIG_SYS_I2C_FSL
2086 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2087 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2088 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2090 - If your board supports a second fsl i2c bus, define
2091 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2092 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2093 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2096 - drivers/i2c/tegra_i2c.c:
2097 - activate this driver with CONFIG_SYS_I2C_TEGRA
2098 - This driver adds 4 i2c buses with a fix speed from
2099 100000 and the slave addr 0!
2101 - drivers/i2c/ppc4xx_i2c.c
2102 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2103 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2104 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2106 - drivers/i2c/i2c_mxc.c
2107 - activate this driver with CONFIG_SYS_I2C_MXC
2108 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2109 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2110 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2111 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2112 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2113 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2114 If thoses defines are not set, default value is 100000
2115 for speed, and 0 for slave.
2117 - drivers/i2c/rcar_i2c.c:
2118 - activate this driver with CONFIG_SYS_I2C_RCAR
2119 - This driver adds 4 i2c buses
2121 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2122 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2123 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2124 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2125 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2126 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2127 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2128 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2129 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2131 - drivers/i2c/sh_i2c.c:
2132 - activate this driver with CONFIG_SYS_I2C_SH
2133 - This driver adds from 2 to 5 i2c buses
2135 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2136 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2137 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2138 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2139 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2140 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2141 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2142 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2143 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2144 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2145 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2146 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2147 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2149 - drivers/i2c/omap24xx_i2c.c
2150 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2151 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2152 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2153 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2154 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2155 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2156 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2157 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2158 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2159 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2160 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2162 - drivers/i2c/zynq_i2c.c
2163 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2164 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2165 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2167 - drivers/i2c/s3c24x0_i2c.c:
2168 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2169 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2170 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2171 with a fix speed from 100000 and the slave addr 0!
2175 CONFIG_SYS_NUM_I2C_BUSES
2176 Hold the number of i2c busses you want to use. If you
2177 don't use/have i2c muxes on your i2c bus, this
2178 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2181 CONFIG_SYS_I2C_DIRECT_BUS
2182 define this, if you don't use i2c muxes on your hardware.
2183 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2186 CONFIG_SYS_I2C_MAX_HOPS
2187 define how many muxes are maximal consecutively connected
2188 on one i2c bus. If you not use i2c muxes, omit this
2191 CONFIG_SYS_I2C_BUSES
2192 hold a list of busses you want to use, only used if
2193 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2194 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2195 CONFIG_SYS_NUM_I2C_BUSES = 9:
2197 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2198 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2199 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2200 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2201 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2202 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2203 {1, {I2C_NULL_HOP}}, \
2204 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2205 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2209 bus 0 on adapter 0 without a mux
2210 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2211 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2212 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2213 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2214 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2215 bus 6 on adapter 1 without a mux
2216 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2217 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2219 If you do not have i2c muxes on your board, omit this define.
2221 - Legacy I2C Support: CONFIG_HARD_I2C
2223 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2224 provides the following compelling advantages:
2226 - more than one i2c adapter is usable
2227 - approved multibus support
2228 - better i2c mux support
2230 ** Please consider updating your I2C driver now. **
2232 These enable legacy I2C serial bus commands. Defining
2233 CONFIG_HARD_I2C will include the appropriate I2C driver
2234 for the selected CPU.
2236 This will allow you to use i2c commands at the u-boot
2237 command line (as long as you set CONFIG_CMD_I2C in
2238 CONFIG_COMMANDS) and communicate with i2c based realtime
2239 clock chips. See common/cmd_i2c.c for a description of the
2240 command line interface.
2242 CONFIG_HARD_I2C selects a hardware I2C controller.
2244 There are several other quantities that must also be
2245 defined when you define CONFIG_HARD_I2C.
2247 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2248 to be the frequency (in Hz) at which you wish your i2c bus
2249 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2250 the CPU's i2c node address).
2252 Now, the u-boot i2c code for the mpc8xx
2253 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2254 and so its address should therefore be cleared to 0 (See,
2255 eg, MPC823e User's Manual p.16-473). So, set
2256 CONFIG_SYS_I2C_SLAVE to 0.
2258 CONFIG_SYS_I2C_INIT_MPC5XXX
2260 When a board is reset during an i2c bus transfer
2261 chips might think that the current transfer is still
2262 in progress. Reset the slave devices by sending start
2263 commands until the slave device responds.
2265 That's all that's required for CONFIG_HARD_I2C.
2267 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2268 then the following macros need to be defined (examples are
2269 from include/configs/lwmon.h):
2273 (Optional). Any commands necessary to enable the I2C
2274 controller or configure ports.
2276 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2280 (Only for MPC8260 CPU). The I/O port to use (the code
2281 assumes both bits are on the same port). Valid values
2282 are 0..3 for ports A..D.
2286 The code necessary to make the I2C data line active
2287 (driven). If the data line is open collector, this
2290 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2294 The code necessary to make the I2C data line tri-stated
2295 (inactive). If the data line is open collector, this
2298 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2302 Code that returns true if the I2C data line is high,
2305 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2309 If <bit> is true, sets the I2C data line high. If it
2310 is false, it clears it (low).
2312 eg: #define I2C_SDA(bit) \
2313 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2314 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2318 If <bit> is true, sets the I2C clock line high. If it
2319 is false, it clears it (low).
2321 eg: #define I2C_SCL(bit) \
2322 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2323 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2327 This delay is invoked four times per clock cycle so this
2328 controls the rate of data transfer. The data rate thus
2329 is 1 / (I2C_DELAY * 4). Often defined to be something
2332 #define I2C_DELAY udelay(2)
2334 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2336 If your arch supports the generic GPIO framework (asm/gpio.h),
2337 then you may alternatively define the two GPIOs that are to be
2338 used as SCL / SDA. Any of the previous I2C_xxx macros will
2339 have GPIO-based defaults assigned to them as appropriate.
2341 You should define these to the GPIO value as given directly to
2342 the generic GPIO functions.
2344 CONFIG_SYS_I2C_INIT_BOARD
2346 When a board is reset during an i2c bus transfer
2347 chips might think that the current transfer is still
2348 in progress. On some boards it is possible to access
2349 the i2c SCLK line directly, either by using the
2350 processor pin as a GPIO or by having a second pin
2351 connected to the bus. If this option is defined a
2352 custom i2c_init_board() routine in boards/xxx/board.c
2353 is run early in the boot sequence.
2355 CONFIG_SYS_I2C_BOARD_LATE_INIT
2357 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2358 defined a custom i2c_board_late_init() routine in
2359 boards/xxx/board.c is run AFTER the operations in i2c_init()
2360 is completed. This callpoint can be used to unreset i2c bus
2361 using CPU i2c controller register accesses for CPUs whose i2c
2362 controller provide such a method. It is called at the end of
2363 i2c_init() to allow i2c_init operations to setup the i2c bus
2364 controller on the CPU (e.g. setting bus speed & slave address).
2366 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2368 This option enables configuration of bi_iic_fast[] flags
2369 in u-boot bd_info structure based on u-boot environment
2370 variable "i2cfast". (see also i2cfast)
2372 CONFIG_I2C_MULTI_BUS
2374 This option allows the use of multiple I2C buses, each of which
2375 must have a controller. At any point in time, only one bus is
2376 active. To switch to a different bus, use the 'i2c dev' command.
2377 Note that bus numbering is zero-based.
2379 CONFIG_SYS_I2C_NOPROBES
2381 This option specifies a list of I2C devices that will be skipped
2382 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2383 is set, specify a list of bus-device pairs. Otherwise, specify
2384 a 1D array of device addresses
2387 #undef CONFIG_I2C_MULTI_BUS
2388 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2390 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2392 #define CONFIG_I2C_MULTI_BUS
2393 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2395 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2397 CONFIG_SYS_SPD_BUS_NUM
2399 If defined, then this indicates the I2C bus number for DDR SPD.
2400 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2402 CONFIG_SYS_RTC_BUS_NUM
2404 If defined, then this indicates the I2C bus number for the RTC.
2405 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2407 CONFIG_SYS_DTT_BUS_NUM
2409 If defined, then this indicates the I2C bus number for the DTT.
2410 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2412 CONFIG_SYS_I2C_DTT_ADDR:
2414 If defined, specifies the I2C address of the DTT device.
2415 If not defined, then U-Boot uses predefined value for
2416 specified DTT device.
2418 CONFIG_SOFT_I2C_READ_REPEATED_START
2420 defining this will force the i2c_read() function in
2421 the soft_i2c driver to perform an I2C repeated start
2422 between writing the address pointer and reading the
2423 data. If this define is omitted the default behaviour
2424 of doing a stop-start sequence will be used. Most I2C
2425 devices can use either method, but some require one or
2428 - SPI Support: CONFIG_SPI
2430 Enables SPI driver (so far only tested with
2431 SPI EEPROM, also an instance works with Crystal A/D and
2432 D/As on the SACSng board)
2436 Enables the driver for SPI controller on SuperH. Currently
2437 only SH7757 is supported.
2441 Enables extended (16-bit) SPI EEPROM addressing.
2442 (symmetrical to CONFIG_I2C_X)
2446 Enables a software (bit-bang) SPI driver rather than
2447 using hardware support. This is a general purpose
2448 driver that only requires three general I/O port pins
2449 (two outputs, one input) to function. If this is
2450 defined, the board configuration must define several
2451 SPI configuration items (port pins to use, etc). For
2452 an example, see include/configs/sacsng.h.
2456 Enables a hardware SPI driver for general-purpose reads
2457 and writes. As with CONFIG_SOFT_SPI, the board configuration
2458 must define a list of chip-select function pointers.
2459 Currently supported on some MPC8xxx processors. For an
2460 example, see include/configs/mpc8349emds.h.
2464 Enables the driver for the SPI controllers on i.MX and MXC
2465 SoCs. Currently i.MX31/35/51 are supported.
2467 - FPGA Support: CONFIG_FPGA
2469 Enables FPGA subsystem.
2471 CONFIG_FPGA_<vendor>
2473 Enables support for specific chip vendors.
2476 CONFIG_FPGA_<family>
2478 Enables support for FPGA family.
2479 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2483 Specify the number of FPGA devices to support.
2485 CONFIG_SYS_FPGA_PROG_FEEDBACK
2487 Enable printing of hash marks during FPGA configuration.
2489 CONFIG_SYS_FPGA_CHECK_BUSY
2491 Enable checks on FPGA configuration interface busy
2492 status by the configuration function. This option
2493 will require a board or device specific function to
2498 If defined, a function that provides delays in the FPGA
2499 configuration driver.
2501 CONFIG_SYS_FPGA_CHECK_CTRLC
2502 Allow Control-C to interrupt FPGA configuration
2504 CONFIG_SYS_FPGA_CHECK_ERROR
2506 Check for configuration errors during FPGA bitfile
2507 loading. For example, abort during Virtex II
2508 configuration if the INIT_B line goes low (which
2509 indicated a CRC error).
2511 CONFIG_SYS_FPGA_WAIT_INIT
2513 Maximum time to wait for the INIT_B line to deassert
2514 after PROB_B has been deasserted during a Virtex II
2515 FPGA configuration sequence. The default time is 500
2518 CONFIG_SYS_FPGA_WAIT_BUSY
2520 Maximum time to wait for BUSY to deassert during
2521 Virtex II FPGA configuration. The default is 5 ms.
2523 CONFIG_SYS_FPGA_WAIT_CONFIG
2525 Time to wait after FPGA configuration. The default is
2528 - Configuration Management:
2531 If defined, this string will be added to the U-Boot
2532 version information (U_BOOT_VERSION)
2534 - Vendor Parameter Protection:
2536 U-Boot considers the values of the environment
2537 variables "serial#" (Board Serial Number) and
2538 "ethaddr" (Ethernet Address) to be parameters that
2539 are set once by the board vendor / manufacturer, and
2540 protects these variables from casual modification by
2541 the user. Once set, these variables are read-only,
2542 and write or delete attempts are rejected. You can
2543 change this behaviour:
2545 If CONFIG_ENV_OVERWRITE is #defined in your config
2546 file, the write protection for vendor parameters is
2547 completely disabled. Anybody can change or delete
2550 Alternatively, if you #define _both_ CONFIG_ETHADDR
2551 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2552 Ethernet address is installed in the environment,
2553 which can be changed exactly ONCE by the user. [The
2554 serial# is unaffected by this, i. e. it remains
2557 The same can be accomplished in a more flexible way
2558 for any variable by configuring the type of access
2559 to allow for those variables in the ".flags" variable
2560 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2565 Define this variable to enable the reservation of
2566 "protected RAM", i. e. RAM which is not overwritten
2567 by U-Boot. Define CONFIG_PRAM to hold the number of
2568 kB you want to reserve for pRAM. You can overwrite
2569 this default value by defining an environment
2570 variable "pram" to the number of kB you want to
2571 reserve. Note that the board info structure will
2572 still show the full amount of RAM. If pRAM is
2573 reserved, a new environment variable "mem" will
2574 automatically be defined to hold the amount of
2575 remaining RAM in a form that can be passed as boot
2576 argument to Linux, for instance like that:
2578 setenv bootargs ... mem=\${mem}
2581 This way you can tell Linux not to use this memory,
2582 either, which results in a memory region that will
2583 not be affected by reboots.
2585 *WARNING* If your board configuration uses automatic
2586 detection of the RAM size, you must make sure that
2587 this memory test is non-destructive. So far, the
2588 following board configurations are known to be
2591 IVMS8, IVML24, SPD8xx, TQM8xxL,
2592 HERMES, IP860, RPXlite, LWMON,
2595 - Access to physical memory region (> 4GB)
2596 Some basic support is provided for operations on memory not
2597 normally accessible to U-Boot - e.g. some architectures
2598 support access to more than 4GB of memory on 32-bit
2599 machines using physical address extension or similar.
2600 Define CONFIG_PHYSMEM to access this basic support, which
2601 currently only supports clearing the memory.
2606 Define this variable to stop the system in case of a
2607 fatal error, so that you have to reset it manually.
2608 This is probably NOT a good idea for an embedded
2609 system where you want the system to reboot
2610 automatically as fast as possible, but it may be
2611 useful during development since you can try to debug
2612 the conditions that lead to the situation.
2614 CONFIG_NET_RETRY_COUNT
2616 This variable defines the number of retries for
2617 network operations like ARP, RARP, TFTP, or BOOTP
2618 before giving up the operation. If not defined, a
2619 default value of 5 is used.
2623 Timeout waiting for an ARP reply in milliseconds.
2627 Timeout in milliseconds used in NFS protocol.
2628 If you encounter "ERROR: Cannot umount" in nfs command,
2629 try longer timeout such as
2630 #define CONFIG_NFS_TIMEOUT 10000UL
2632 - Command Interpreter:
2633 CONFIG_AUTO_COMPLETE
2635 Enable auto completion of commands using TAB.
2637 Note that this feature has NOT been implemented yet
2638 for the "hush" shell.
2641 CONFIG_SYS_HUSH_PARSER
2643 Define this variable to enable the "hush" shell (from
2644 Busybox) as command line interpreter, thus enabling
2645 powerful command line syntax like
2646 if...then...else...fi conditionals or `&&' and '||'
2647 constructs ("shell scripts").
2649 If undefined, you get the old, much simpler behaviour
2650 with a somewhat smaller memory footprint.
2653 CONFIG_SYS_PROMPT_HUSH_PS2
2655 This defines the secondary prompt string, which is
2656 printed when the command interpreter needs more input
2657 to complete a command. Usually "> ".
2661 In the current implementation, the local variables
2662 space and global environment variables space are
2663 separated. Local variables are those you define by
2664 simply typing `name=value'. To access a local
2665 variable later on, you have write `$name' or
2666 `${name}'; to execute the contents of a variable
2667 directly type `$name' at the command prompt.
2669 Global environment variables are those you use
2670 setenv/printenv to work with. To run a command stored
2671 in such a variable, you need to use the run command,
2672 and you must not use the '$' sign to access them.
2674 To store commands and special characters in a
2675 variable, please use double quotation marks
2676 surrounding the whole text of the variable, instead
2677 of the backslashes before semicolons and special
2680 - Commandline Editing and History:
2681 CONFIG_CMDLINE_EDITING
2683 Enable editing and History functions for interactive
2684 commandline input operations
2686 - Default Environment:
2687 CONFIG_EXTRA_ENV_SETTINGS
2689 Define this to contain any number of null terminated
2690 strings (variable = value pairs) that will be part of
2691 the default environment compiled into the boot image.
2693 For example, place something like this in your
2694 board's config file:
2696 #define CONFIG_EXTRA_ENV_SETTINGS \
2700 Warning: This method is based on knowledge about the
2701 internal format how the environment is stored by the
2702 U-Boot code. This is NOT an official, exported
2703 interface! Although it is unlikely that this format
2704 will change soon, there is no guarantee either.
2705 You better know what you are doing here.
2707 Note: overly (ab)use of the default environment is
2708 discouraged. Make sure to check other ways to preset
2709 the environment like the "source" command or the
2712 CONFIG_ENV_VARS_UBOOT_CONFIG
2714 Define this in order to add variables describing the
2715 U-Boot build configuration to the default environment.
2716 These will be named arch, cpu, board, vendor, and soc.
2718 Enabling this option will cause the following to be defined:
2726 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2728 Define this in order to add variables describing certain
2729 run-time determined information about the hardware to the
2730 environment. These will be named board_name, board_rev.
2732 CONFIG_DELAY_ENVIRONMENT
2734 Normally the environment is loaded when the board is
2735 intialised so that it is available to U-Boot. This inhibits
2736 that so that the environment is not available until
2737 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2738 this is instead controlled by the value of
2739 /config/load-environment.
2741 - DataFlash Support:
2742 CONFIG_HAS_DATAFLASH
2744 Defining this option enables DataFlash features and
2745 allows to read/write in Dataflash via the standard
2748 - Serial Flash support
2751 Defining this option enables SPI flash commands
2752 'sf probe/read/write/erase/update'.
2754 Usage requires an initial 'probe' to define the serial
2755 flash parameters, followed by read/write/erase/update
2758 The following defaults may be provided by the platform
2759 to handle the common case when only a single serial
2760 flash is present on the system.
2762 CONFIG_SF_DEFAULT_BUS Bus identifier
2763 CONFIG_SF_DEFAULT_CS Chip-select
2764 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2765 CONFIG_SF_DEFAULT_SPEED in Hz
2769 Define this option to include a destructive SPI flash
2772 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2774 Define this option to use the Bank addr/Extended addr
2775 support on SPI flashes which has size > 16Mbytes.
2777 CONFIG_SF_DUAL_FLASH Dual flash memories
2779 Define this option to use dual flash support where two flash
2780 memories can be connected with a given cs line.
2781 currently Xilinx Zynq qspi support these type of connections.
2783 - SystemACE Support:
2786 Adding this option adds support for Xilinx SystemACE
2787 chips attached via some sort of local bus. The address
2788 of the chip must also be defined in the
2789 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2791 #define CONFIG_SYSTEMACE
2792 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2794 When SystemACE support is added, the "ace" device type
2795 becomes available to the fat commands, i.e. fatls.
2797 - TFTP Fixed UDP Port:
2800 If this is defined, the environment variable tftpsrcp
2801 is used to supply the TFTP UDP source port value.
2802 If tftpsrcp isn't defined, the normal pseudo-random port
2803 number generator is used.
2805 Also, the environment variable tftpdstp is used to supply
2806 the TFTP UDP destination port value. If tftpdstp isn't
2807 defined, the normal port 69 is used.
2809 The purpose for tftpsrcp is to allow a TFTP server to
2810 blindly start the TFTP transfer using the pre-configured
2811 target IP address and UDP port. This has the effect of
2812 "punching through" the (Windows XP) firewall, allowing
2813 the remainder of the TFTP transfer to proceed normally.
2814 A better solution is to properly configure the firewall,
2815 but sometimes that is not allowed.
2820 This enables a generic 'hash' command which can produce
2821 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2825 Enable the hash verify command (hash -v). This adds to code
2828 CONFIG_SHA1 - support SHA1 hashing
2829 CONFIG_SHA256 - support SHA256 hashing
2831 Note: There is also a sha1sum command, which should perhaps
2832 be deprecated in favour of 'hash sha1'.
2834 - Freescale i.MX specific commands:
2835 CONFIG_CMD_HDMIDETECT
2836 This enables 'hdmidet' command which returns true if an
2837 HDMI monitor is detected. This command is i.MX 6 specific.
2840 This enables the 'bmode' (bootmode) command for forcing
2841 a boot from specific media.
2843 This is useful for forcing the ROM's usb downloader to
2844 activate upon a watchdog reset which is nice when iterating
2845 on U-Boot. Using the reset button or running bmode normal
2846 will set it back to normal. This command currently
2847 supports i.MX53 and i.MX6.
2852 This enables the RSA algorithm used for FIT image verification
2853 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2855 The signing part is build into mkimage regardless of this
2859 - Show boot progress:
2860 CONFIG_SHOW_BOOT_PROGRESS
2862 Defining this option allows to add some board-
2863 specific code (calling a user-provided function
2864 "show_boot_progress(int)") that enables you to show
2865 the system's boot progress on some display (for
2866 example, some LED's) on your board. At the moment,
2867 the following checkpoints are implemented:
2869 - Detailed boot stage timing
2871 Define this option to get detailed timing of each stage
2872 of the boot process.
2874 CONFIG_BOOTSTAGE_USER_COUNT
2875 This is the number of available user bootstage records.
2876 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2877 a new ID will be allocated from this stash. If you exceed
2878 the limit, recording will stop.
2880 CONFIG_BOOTSTAGE_REPORT
2881 Define this to print a report before boot, similar to this:
2883 Timer summary in microseconds:
2886 3,575,678 3,575,678 board_init_f start
2887 3,575,695 17 arch_cpu_init A9
2888 3,575,777 82 arch_cpu_init done
2889 3,659,598 83,821 board_init_r start
2890 3,910,375 250,777 main_loop
2891 29,916,167 26,005,792 bootm_start
2892 30,361,327 445,160 start_kernel
2894 CONFIG_CMD_BOOTSTAGE
2895 Add a 'bootstage' command which supports printing a report
2896 and un/stashing of bootstage data.
2898 CONFIG_BOOTSTAGE_FDT
2899 Stash the bootstage information in the FDT. A root 'bootstage'
2900 node is created with each bootstage id as a child. Each child
2901 has a 'name' property and either 'mark' containing the
2902 mark time in microsecond, or 'accum' containing the
2903 accumulated time for that bootstage id in microseconds.
2908 name = "board_init_f";
2917 Code in the Linux kernel can find this in /proc/devicetree.
2919 Legacy uImage format:
2922 1 common/cmd_bootm.c before attempting to boot an image
2923 -1 common/cmd_bootm.c Image header has bad magic number
2924 2 common/cmd_bootm.c Image header has correct magic number
2925 -2 common/cmd_bootm.c Image header has bad checksum
2926 3 common/cmd_bootm.c Image header has correct checksum
2927 -3 common/cmd_bootm.c Image data has bad checksum
2928 4 common/cmd_bootm.c Image data has correct checksum
2929 -4 common/cmd_bootm.c Image is for unsupported architecture
2930 5 common/cmd_bootm.c Architecture check OK
2931 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2932 6 common/cmd_bootm.c Image Type check OK
2933 -6 common/cmd_bootm.c gunzip uncompression error
2934 -7 common/cmd_bootm.c Unimplemented compression type
2935 7 common/cmd_bootm.c Uncompression OK
2936 8 common/cmd_bootm.c No uncompress/copy overwrite error
2937 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2939 9 common/image.c Start initial ramdisk verification
2940 -10 common/image.c Ramdisk header has bad magic number
2941 -11 common/image.c Ramdisk header has bad checksum
2942 10 common/image.c Ramdisk header is OK
2943 -12 common/image.c Ramdisk data has bad checksum
2944 11 common/image.c Ramdisk data has correct checksum
2945 12 common/image.c Ramdisk verification complete, start loading
2946 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2947 13 common/image.c Start multifile image verification
2948 14 common/image.c No initial ramdisk, no multifile, continue.
2950 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2952 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2953 -31 post/post.c POST test failed, detected by post_output_backlog()
2954 -32 post/post.c POST test failed, detected by post_run_single()
2956 34 common/cmd_doc.c before loading a Image from a DOC device
2957 -35 common/cmd_doc.c Bad usage of "doc" command
2958 35 common/cmd_doc.c correct usage of "doc" command
2959 -36 common/cmd_doc.c No boot device
2960 36 common/cmd_doc.c correct boot device
2961 -37 common/cmd_doc.c Unknown Chip ID on boot device
2962 37 common/cmd_doc.c correct chip ID found, device available
2963 -38 common/cmd_doc.c Read Error on boot device
2964 38 common/cmd_doc.c reading Image header from DOC device OK
2965 -39 common/cmd_doc.c Image header has bad magic number
2966 39 common/cmd_doc.c Image header has correct magic number
2967 -40 common/cmd_doc.c Error reading Image from DOC device
2968 40 common/cmd_doc.c Image header has correct magic number
2969 41 common/cmd_ide.c before loading a Image from a IDE device
2970 -42 common/cmd_ide.c Bad usage of "ide" command
2971 42 common/cmd_ide.c correct usage of "ide" command
2972 -43 common/cmd_ide.c No boot device
2973 43 common/cmd_ide.c boot device found
2974 -44 common/cmd_ide.c Device not available
2975 44 common/cmd_ide.c Device available
2976 -45 common/cmd_ide.c wrong partition selected
2977 45 common/cmd_ide.c partition selected
2978 -46 common/cmd_ide.c Unknown partition table
2979 46 common/cmd_ide.c valid partition table found
2980 -47 common/cmd_ide.c Invalid partition type
2981 47 common/cmd_ide.c correct partition type
2982 -48 common/cmd_ide.c Error reading Image Header on boot device
2983 48 common/cmd_ide.c reading Image Header from IDE device OK
2984 -49 common/cmd_ide.c Image header has bad magic number
2985 49 common/cmd_ide.c Image header has correct magic number
2986 -50 common/cmd_ide.c Image header has bad checksum
2987 50 common/cmd_ide.c Image header has correct checksum
2988 -51 common/cmd_ide.c Error reading Image from IDE device
2989 51 common/cmd_ide.c reading Image from IDE device OK
2990 52 common/cmd_nand.c before loading a Image from a NAND device
2991 -53 common/cmd_nand.c Bad usage of "nand" command
2992 53 common/cmd_nand.c correct usage of "nand" command
2993 -54 common/cmd_nand.c No boot device
2994 54 common/cmd_nand.c boot device found
2995 -55 common/cmd_nand.c Unknown Chip ID on boot device
2996 55 common/cmd_nand.c correct chip ID found, device available
2997 -56 common/cmd_nand.c Error reading Image Header on boot device
2998 56 common/cmd_nand.c reading Image Header from NAND device OK
2999 -57 common/cmd_nand.c Image header has bad magic number
3000 57 common/cmd_nand.c Image header has correct magic number
3001 -58 common/cmd_nand.c Error reading Image from NAND device
3002 58 common/cmd_nand.c reading Image from NAND device OK
3004 -60 common/env_common.c Environment has a bad CRC, using default
3006 64 net/eth.c starting with Ethernet configuration.
3007 -64 net/eth.c no Ethernet found.
3008 65 net/eth.c Ethernet found.
3010 -80 common/cmd_net.c usage wrong
3011 80 common/cmd_net.c before calling NetLoop()
3012 -81 common/cmd_net.c some error in NetLoop() occurred
3013 81 common/cmd_net.c NetLoop() back without error
3014 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3015 82 common/cmd_net.c trying automatic boot
3016 83 common/cmd_net.c running "source" command
3017 -83 common/cmd_net.c some error in automatic boot or "source" command
3018 84 common/cmd_net.c end without errors
3023 100 common/cmd_bootm.c Kernel FIT Image has correct format
3024 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3025 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3026 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3027 102 common/cmd_bootm.c Kernel unit name specified
3028 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3029 103 common/cmd_bootm.c Found configuration node
3030 104 common/cmd_bootm.c Got kernel subimage node offset
3031 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3032 105 common/cmd_bootm.c Kernel subimage hash verification OK
3033 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3034 106 common/cmd_bootm.c Architecture check OK
3035 -106 common/cmd_bootm.c Kernel subimage has wrong type
3036 107 common/cmd_bootm.c Kernel subimage type OK
3037 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3038 108 common/cmd_bootm.c Got kernel subimage data/size
3039 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3040 -109 common/cmd_bootm.c Can't get kernel subimage type
3041 -110 common/cmd_bootm.c Can't get kernel subimage comp
3042 -111 common/cmd_bootm.c Can't get kernel subimage os
3043 -112 common/cmd_bootm.c Can't get kernel subimage load address
3044 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3046 120 common/image.c Start initial ramdisk verification
3047 -120 common/image.c Ramdisk FIT image has incorrect format
3048 121 common/image.c Ramdisk FIT image has correct format
3049 122 common/image.c No ramdisk subimage unit name, using configuration
3050 -122 common/image.c Can't get configuration for ramdisk subimage
3051 123 common/image.c Ramdisk unit name specified
3052 -124 common/image.c Can't get ramdisk subimage node offset
3053 125 common/image.c Got ramdisk subimage node offset
3054 -125 common/image.c Ramdisk subimage hash verification failed
3055 126 common/image.c Ramdisk subimage hash verification OK
3056 -126 common/image.c Ramdisk subimage for unsupported architecture
3057 127 common/image.c Architecture check OK
3058 -127 common/image.c Can't get ramdisk subimage data/size
3059 128 common/image.c Got ramdisk subimage data/size
3060 129 common/image.c Can't get ramdisk load address
3061 -129 common/image.c Got ramdisk load address
3063 -130 common/cmd_doc.c Incorrect FIT image format
3064 131 common/cmd_doc.c FIT image format OK
3066 -140 common/cmd_ide.c Incorrect FIT image format
3067 141 common/cmd_ide.c FIT image format OK
3069 -150 common/cmd_nand.c Incorrect FIT image format
3070 151 common/cmd_nand.c FIT image format OK
3072 - FIT image support:
3074 Enable support for the FIT uImage format.
3076 CONFIG_FIT_BEST_MATCH
3077 When no configuration is explicitly selected, default to the
3078 one whose fdt's compatibility field best matches that of
3079 U-Boot itself. A match is considered "best" if it matches the
3080 most specific compatibility entry of U-Boot's fdt's root node.
3081 The order of entries in the configuration's fdt is ignored.
3083 CONFIG_FIT_SIGNATURE
3084 This option enables signature verification of FIT uImages,
3085 using a hash signed and verified using RSA. See
3086 doc/uImage.FIT/signature.txt for more details.
3088 - Standalone program support:
3089 CONFIG_STANDALONE_LOAD_ADDR
3091 This option defines a board specific value for the
3092 address where standalone program gets loaded, thus
3093 overwriting the architecture dependent default
3096 - Frame Buffer Address:
3099 Define CONFIG_FB_ADDR if you want to use specific
3100 address for frame buffer. This is typically the case
3101 when using a graphics controller has separate video
3102 memory. U-Boot will then place the frame buffer at
3103 the given address instead of dynamically reserving it
3104 in system RAM by calling lcd_setmem(), which grabs
3105 the memory for the frame buffer depending on the
3106 configured panel size.
3108 Please see board_init_f function.
3110 - Automatic software updates via TFTP server
3112 CONFIG_UPDATE_TFTP_CNT_MAX
3113 CONFIG_UPDATE_TFTP_MSEC_MAX
3115 These options enable and control the auto-update feature;
3116 for a more detailed description refer to doc/README.update.
3118 - MTD Support (mtdparts command, UBI support)
3121 Adds the MTD device infrastructure from the Linux kernel.
3122 Needed for mtdparts command support.
3124 CONFIG_MTD_PARTITIONS
3126 Adds the MTD partitioning infrastructure from the Linux
3127 kernel. Needed for UBI support.
3132 Adds commands for interacting with MTD partitions formatted
3133 with the UBI flash translation layer
3135 Requires also defining CONFIG_RBTREE
3137 CONFIG_UBI_SILENCE_MSG
3139 Make the verbose messages from UBI stop printing. This leaves
3140 warnings and errors enabled.
3145 Adds commands for interacting with UBI volumes formatted as
3146 UBIFS. UBIFS is read-only in u-boot.
3148 Requires UBI support as well as CONFIG_LZO
3150 CONFIG_UBIFS_SILENCE_MSG
3152 Make the verbose messages from UBIFS stop printing. This leaves
3153 warnings and errors enabled.
3157 Enable building of SPL globally.
3160 LDSCRIPT for linking the SPL binary.
3162 CONFIG_SPL_MAX_FOOTPRINT
3163 Maximum size in memory allocated to the SPL, BSS included.
3164 When defined, the linker checks that the actual memory
3165 used by SPL from _start to __bss_end does not exceed it.
3166 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3167 must not be both defined at the same time.
3170 Maximum size of the SPL image (text, data, rodata, and
3171 linker lists sections), BSS excluded.
3172 When defined, the linker checks that the actual size does
3175 CONFIG_SPL_TEXT_BASE
3176 TEXT_BASE for linking the SPL binary.
3178 CONFIG_SPL_RELOC_TEXT_BASE
3179 Address to relocate to. If unspecified, this is equal to
3180 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3182 CONFIG_SPL_BSS_START_ADDR
3183 Link address for the BSS within the SPL binary.
3185 CONFIG_SPL_BSS_MAX_SIZE
3186 Maximum size in memory allocated to the SPL BSS.
3187 When defined, the linker checks that the actual memory used
3188 by SPL from __bss_start to __bss_end does not exceed it.
3189 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3190 must not be both defined at the same time.
3193 Adress of the start of the stack SPL will use
3195 CONFIG_SPL_RELOC_STACK
3196 Adress of the start of the stack SPL will use after
3197 relocation. If unspecified, this is equal to
3200 CONFIG_SYS_SPL_MALLOC_START
3201 Starting address of the malloc pool used in SPL.
3203 CONFIG_SYS_SPL_MALLOC_SIZE
3204 The size of the malloc pool used in SPL.
3206 CONFIG_SPL_FRAMEWORK
3207 Enable the SPL framework under common/. This framework
3208 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3209 NAND loading of the Linux Kernel.
3211 CONFIG_SPL_DISPLAY_PRINT
3212 For ARM, enable an optional function to print more information
3213 about the running system.
3215 CONFIG_SPL_INIT_MINIMAL
3216 Arch init code should be built for a very small image
3218 CONFIG_SPL_LIBCOMMON_SUPPORT
3219 Support for common/libcommon.o in SPL binary
3221 CONFIG_SPL_LIBDISK_SUPPORT
3222 Support for disk/libdisk.o in SPL binary
3224 CONFIG_SPL_I2C_SUPPORT
3225 Support for drivers/i2c/libi2c.o in SPL binary
3227 CONFIG_SPL_GPIO_SUPPORT
3228 Support for drivers/gpio/libgpio.o in SPL binary
3230 CONFIG_SPL_MMC_SUPPORT
3231 Support for drivers/mmc/libmmc.o in SPL binary
3233 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3234 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3235 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3236 Address, size and partition on the MMC to load U-Boot from
3237 when the MMC is being used in raw mode.
3239 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3240 Sector to load kernel uImage from when MMC is being
3241 used in raw mode (for Falcon mode)
3243 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3244 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3245 Sector and number of sectors to load kernel argument
3246 parameters from when MMC is being used in raw mode
3249 CONFIG_SPL_FAT_SUPPORT
3250 Support for fs/fat/libfat.o in SPL binary
3252 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3253 Filename to read to load U-Boot when reading from FAT
3255 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3256 Filename to read to load kernel uImage when reading
3257 from FAT (for Falcon mode)
3259 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3260 Filename to read to load kernel argument parameters
3261 when reading from FAT (for Falcon mode)
3263 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3264 Set this for NAND SPL on PPC mpc83xx targets, so that
3265 start.S waits for the rest of the SPL to load before
3266 continuing (the hardware starts execution after just
3267 loading the first page rather than the full 4K).
3269 CONFIG_SPL_NAND_BASE
3270 Include nand_base.c in the SPL. Requires
3271 CONFIG_SPL_NAND_DRIVERS.
3273 CONFIG_SPL_NAND_DRIVERS
3274 SPL uses normal NAND drivers, not minimal drivers.
3277 Include standard software ECC in the SPL
3279 CONFIG_SPL_NAND_SIMPLE
3280 Support for NAND boot using simple NAND drivers that
3281 expose the cmd_ctrl() interface.
3283 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3284 Set for the SPL on PPC mpc8xxx targets, support for
3285 drivers/ddr/fsl/libddr.o in SPL binary.
3287 CONFIG_SPL_COMMON_INIT_DDR
3288 Set for common ddr init with serial presence detect in
3291 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3292 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3293 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3294 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3295 CONFIG_SYS_NAND_ECCBYTES
3296 Defines the size and behavior of the NAND that SPL uses
3299 CONFIG_SPL_NAND_BOOT
3300 Add support NAND boot
3302 CONFIG_SYS_NAND_U_BOOT_OFFS
3303 Location in NAND to read U-Boot from
3305 CONFIG_SYS_NAND_U_BOOT_DST
3306 Location in memory to load U-Boot to
3308 CONFIG_SYS_NAND_U_BOOT_SIZE
3309 Size of image to load
3311 CONFIG_SYS_NAND_U_BOOT_START
3312 Entry point in loaded image to jump to
3314 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3315 Define this if you need to first read the OOB and then the
3316 data. This is used for example on davinci plattforms.
3318 CONFIG_SPL_OMAP3_ID_NAND
3319 Support for an OMAP3-specific set of functions to return the
3320 ID and MFR of the first attached NAND chip, if present.
3322 CONFIG_SPL_SERIAL_SUPPORT
3323 Support for drivers/serial/libserial.o in SPL binary
3325 CONFIG_SPL_SPI_FLASH_SUPPORT
3326 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3328 CONFIG_SPL_SPI_SUPPORT
3329 Support for drivers/spi/libspi.o in SPL binary
3331 CONFIG_SPL_RAM_DEVICE
3332 Support for running image already present in ram, in SPL binary
3334 CONFIG_SPL_LIBGENERIC_SUPPORT
3335 Support for lib/libgeneric.o in SPL binary
3337 CONFIG_SPL_ENV_SUPPORT
3338 Support for the environment operating in SPL binary
3340 CONFIG_SPL_NET_SUPPORT
3341 Support for the net/libnet.o in SPL binary.
3342 It conflicts with SPL env from storage medium specified by
3343 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3346 Image offset to which the SPL should be padded before appending
3347 the SPL payload. By default, this is defined as
3348 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3349 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3350 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3353 Final target image containing SPL and payload. Some SPLs
3354 use an arch-specific makefile fragment instead, for
3355 example if more than one image needs to be produced.
3357 CONFIG_FIT_SPL_PRINT
3358 Printing information about a FIT image adds quite a bit of
3359 code to SPL. So this is normally disabled in SPL. Use this
3360 option to re-enable it. This will affect the output of the
3361 bootm command when booting a FIT image.
3365 Enable building of TPL globally.
3368 Image offset to which the TPL should be padded before appending
3369 the TPL payload. By default, this is defined as
3370 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3371 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3372 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3377 [so far only for SMDK2400 boards]
3379 - Modem support enable:
3380 CONFIG_MODEM_SUPPORT
3382 - RTS/CTS Flow control enable:
3385 - Modem debug support:
3386 CONFIG_MODEM_SUPPORT_DEBUG
3388 Enables debugging stuff (char screen[1024], dbg())
3389 for modem support. Useful only with BDI2000.
3391 - Interrupt support (PPC):
3393 There are common interrupt_init() and timer_interrupt()
3394 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3395 for CPU specific initialization. interrupt_init_cpu()
3396 should set decrementer_count to appropriate value. If
3397 CPU resets decrementer automatically after interrupt
3398 (ppc4xx) it should set decrementer_count to zero.
3399 timer_interrupt() calls timer_interrupt_cpu() for CPU
3400 specific handling. If board has watchdog / status_led
3401 / other_activity_monitor it works automatically from
3402 general timer_interrupt().
3406 In the target system modem support is enabled when a
3407 specific key (key combination) is pressed during
3408 power-on. Otherwise U-Boot will boot normally
3409 (autoboot). The key_pressed() function is called from
3410 board_init(). Currently key_pressed() is a dummy
3411 function, returning 1 and thus enabling modem
3414 If there are no modem init strings in the
3415 environment, U-Boot proceed to autoboot; the
3416 previous output (banner, info printfs) will be
3419 See also: doc/README.Modem
3421 Board initialization settings:
3422 ------------------------------
3424 During Initialization u-boot calls a number of board specific functions
3425 to allow the preparation of board specific prerequisites, e.g. pin setup
3426 before drivers are initialized. To enable these callbacks the
3427 following configuration macros have to be defined. Currently this is
3428 architecture specific, so please check arch/your_architecture/lib/board.c
3429 typically in board_init_f() and board_init_r().
3431 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3432 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3433 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3434 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3436 Configuration Settings:
3437 -----------------------
3439 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3440 undefine this when you're short of memory.
3442 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3443 width of the commands listed in the 'help' command output.
3445 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3446 prompt for user input.
3448 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3450 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3452 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3454 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3455 the application (usually a Linux kernel) when it is
3458 - CONFIG_SYS_BAUDRATE_TABLE:
3459 List of legal baudrate settings for this board.
3461 - CONFIG_SYS_CONSOLE_INFO_QUIET
3462 Suppress display of console information at boot.
3464 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3465 If the board specific function
3466 extern int overwrite_console (void);
3467 returns 1, the stdin, stderr and stdout are switched to the
3468 serial port, else the settings in the environment are used.
3470 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3471 Enable the call to overwrite_console().
3473 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3474 Enable overwrite of previous console environment settings.
3476 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3477 Begin and End addresses of the area used by the
3480 - CONFIG_SYS_ALT_MEMTEST:
3481 Enable an alternate, more extensive memory test.
3483 - CONFIG_SYS_MEMTEST_SCRATCH:
3484 Scratch address used by the alternate memory test
3485 You only need to set this if address zero isn't writeable
3487 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3488 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3489 this specified memory area will get subtracted from the top
3490 (end) of RAM and won't get "touched" at all by U-Boot. By
3491 fixing up gd->ram_size the Linux kernel should gets passed
3492 the now "corrected" memory size and won't touch it either.
3493 This should work for arch/ppc and arch/powerpc. Only Linux
3494 board ports in arch/powerpc with bootwrapper support that
3495 recalculate the memory size from the SDRAM controller setup
3496 will have to get fixed in Linux additionally.
3498 This option can be used as a workaround for the 440EPx/GRx
3499 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3502 WARNING: Please make sure that this value is a multiple of
3503 the Linux page size (normally 4k). If this is not the case,
3504 then the end address of the Linux memory will be located at a
3505 non page size aligned address and this could cause major
3508 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3509 Enable temporary baudrate change while serial download
3511 - CONFIG_SYS_SDRAM_BASE:
3512 Physical start address of SDRAM. _Must_ be 0 here.
3514 - CONFIG_SYS_MBIO_BASE:
3515 Physical start address of Motherboard I/O (if using a
3518 - CONFIG_SYS_FLASH_BASE:
3519 Physical start address of Flash memory.
3521 - CONFIG_SYS_MONITOR_BASE:
3522 Physical start address of boot monitor code (set by
3523 make config files to be same as the text base address
3524 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3525 CONFIG_SYS_FLASH_BASE when booting from flash.
3527 - CONFIG_SYS_MONITOR_LEN:
3528 Size of memory reserved for monitor code, used to
3529 determine _at_compile_time_ (!) if the environment is
3530 embedded within the U-Boot image, or in a separate
3533 - CONFIG_SYS_MALLOC_LEN:
3534 Size of DRAM reserved for malloc() use.
3536 - CONFIG_SYS_BOOTM_LEN:
3537 Normally compressed uImages are limited to an
3538 uncompressed size of 8 MBytes. If this is not enough,
3539 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3540 to adjust this setting to your needs.
3542 - CONFIG_SYS_BOOTMAPSZ:
3543 Maximum size of memory mapped by the startup code of
3544 the Linux kernel; all data that must be processed by
3545 the Linux kernel (bd_info, boot arguments, FDT blob if
3546 used) must be put below this limit, unless "bootm_low"
3547 environment variable is defined and non-zero. In such case
3548 all data for the Linux kernel must be between "bootm_low"
3549 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3550 variable "bootm_mapsize" will override the value of
3551 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3552 then the value in "bootm_size" will be used instead.
3554 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3555 Enable initrd_high functionality. If defined then the
3556 initrd_high feature is enabled and the bootm ramdisk subcommand
3559 - CONFIG_SYS_BOOT_GET_CMDLINE:
3560 Enables allocating and saving kernel cmdline in space between
3561 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3563 - CONFIG_SYS_BOOT_GET_KBD:
3564 Enables allocating and saving a kernel copy of the bd_info in
3565 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3567 - CONFIG_SYS_MAX_FLASH_BANKS:
3568 Max number of Flash memory banks
3570 - CONFIG_SYS_MAX_FLASH_SECT:
3571 Max number of sectors on a Flash chip
3573 - CONFIG_SYS_FLASH_ERASE_TOUT:
3574 Timeout for Flash erase operations (in ms)
3576 - CONFIG_SYS_FLASH_WRITE_TOUT:
3577 Timeout for Flash write operations (in ms)
3579 - CONFIG_SYS_FLASH_LOCK_TOUT
3580 Timeout for Flash set sector lock bit operation (in ms)
3582 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3583 Timeout for Flash clear lock bits operation (in ms)
3585 - CONFIG_SYS_FLASH_PROTECTION
3586 If defined, hardware flash sectors protection is used
3587 instead of U-Boot software protection.
3589 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3591 Enable TFTP transfers directly to flash memory;
3592 without this option such a download has to be
3593 performed in two steps: (1) download to RAM, and (2)
3594 copy from RAM to flash.
3596 The two-step approach is usually more reliable, since
3597 you can check if the download worked before you erase
3598 the flash, but in some situations (when system RAM is
3599 too limited to allow for a temporary copy of the
3600 downloaded image) this option may be very useful.
3602 - CONFIG_SYS_FLASH_CFI:
3603 Define if the flash driver uses extra elements in the
3604 common flash structure for storing flash geometry.
3606 - CONFIG_FLASH_CFI_DRIVER
3607 This option also enables the building of the cfi_flash driver
3608 in the drivers directory
3610 - CONFIG_FLASH_CFI_MTD
3611 This option enables the building of the cfi_mtd driver
3612 in the drivers directory. The driver exports CFI flash
3615 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3616 Use buffered writes to flash.
3618 - CONFIG_FLASH_SPANSION_S29WS_N
3619 s29ws-n MirrorBit flash has non-standard addresses for buffered
3622 - CONFIG_SYS_FLASH_QUIET_TEST
3623 If this option is defined, the common CFI flash doesn't
3624 print it's warning upon not recognized FLASH banks. This
3625 is useful, if some of the configured banks are only
3626 optionally available.
3628 - CONFIG_FLASH_SHOW_PROGRESS
3629 If defined (must be an integer), print out countdown
3630 digits and dots. Recommended value: 45 (9..1) for 80
3631 column displays, 15 (3..1) for 40 column displays.
3633 - CONFIG_FLASH_VERIFY
3634 If defined, the content of the flash (destination) is compared
3635 against the source after the write operation. An error message
3636 will be printed when the contents are not identical.
3637 Please note that this option is useless in nearly all cases,
3638 since such flash programming errors usually are detected earlier
3639 while unprotecting/erasing/programming. Please only enable
3640 this option if you really know what you are doing.
3642 - CONFIG_SYS_RX_ETH_BUFFER:
3643 Defines the number of Ethernet receive buffers. On some
3644 Ethernet controllers it is recommended to set this value
3645 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3646 buffers can be full shortly after enabling the interface
3647 on high Ethernet traffic.
3648 Defaults to 4 if not defined.
3650 - CONFIG_ENV_MAX_ENTRIES
3652 Maximum number of entries in the hash table that is used
3653 internally to store the environment settings. The default
3654 setting is supposed to be generous and should work in most
3655 cases. This setting can be used to tune behaviour; see
3656 lib/hashtable.c for details.
3658 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3659 - CONFIG_ENV_FLAGS_LIST_STATIC
3660 Enable validation of the values given to environment variables when
3661 calling env set. Variables can be restricted to only decimal,
3662 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3663 the variables can also be restricted to IP address or MAC address.
3665 The format of the list is:
3666 type_attribute = [s|d|x|b|i|m]
3667 access_atribute = [a|r|o|c]
3668 attributes = type_attribute[access_atribute]
3669 entry = variable_name[:attributes]
3672 The type attributes are:
3673 s - String (default)
3676 b - Boolean ([1yYtT|0nNfF])
3680 The access attributes are:
3686 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3687 Define this to a list (string) to define the ".flags"
3688 envirnoment variable in the default or embedded environment.
3690 - CONFIG_ENV_FLAGS_LIST_STATIC
3691 Define this to a list (string) to define validation that
3692 should be done if an entry is not found in the ".flags"
3693 environment variable. To override a setting in the static
3694 list, simply add an entry for the same variable name to the
3697 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3698 If defined, don't allow the -f switch to env set override variable
3701 - CONFIG_SYS_GENERIC_BOARD
3702 This selects the architecture-generic board system instead of the
3703 architecture-specific board files. It is intended to move boards
3704 to this new framework over time. Defining this will disable the
3705 arch/foo/lib/board.c file and use common/board_f.c and
3706 common/board_r.c instead. To use this option your architecture
3707 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3708 its config.mk file). If you find problems enabling this option on
3709 your board please report the problem and send patches!
3711 - CONFIG_SYS_SYM_OFFSETS
3712 This is set by architectures that use offsets for link symbols
3713 instead of absolute values. So bss_start is obtained using an
3714 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3715 directly. You should not need to touch this setting.
3717 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3718 This is set by OMAP boards for the max time that reset should
3719 be asserted. See doc/README.omap-reset-time for details on how
3720 the value can be calulated on a given board.
3722 The following definitions that deal with the placement and management
3723 of environment data (variable area); in general, we support the
3724 following configurations:
3726 - CONFIG_BUILD_ENVCRC:
3728 Builds up envcrc with the target environment so that external utils
3729 may easily extract it and embed it in final U-Boot images.
3731 - CONFIG_ENV_IS_IN_FLASH:
3733 Define this if the environment is in flash memory.
3735 a) The environment occupies one whole flash sector, which is
3736 "embedded" in the text segment with the U-Boot code. This
3737 happens usually with "bottom boot sector" or "top boot
3738 sector" type flash chips, which have several smaller
3739 sectors at the start or the end. For instance, such a
3740 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3741 such a case you would place the environment in one of the
3742 4 kB sectors - with U-Boot code before and after it. With
3743 "top boot sector" type flash chips, you would put the
3744 environment in one of the last sectors, leaving a gap
3745 between U-Boot and the environment.
3747 - CONFIG_ENV_OFFSET:
3749 Offset of environment data (variable area) to the
3750 beginning of flash memory; for instance, with bottom boot
3751 type flash chips the second sector can be used: the offset
3752 for this sector is given here.
3754 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3758 This is just another way to specify the start address of
3759 the flash sector containing the environment (instead of
3762 - CONFIG_ENV_SECT_SIZE:
3764 Size of the sector containing the environment.
3767 b) Sometimes flash chips have few, equal sized, BIG sectors.
3768 In such a case you don't want to spend a whole sector for
3773 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3774 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3775 of this flash sector for the environment. This saves
3776 memory for the RAM copy of the environment.
3778 It may also save flash memory if you decide to use this
3779 when your environment is "embedded" within U-Boot code,
3780 since then the remainder of the flash sector could be used
3781 for U-Boot code. It should be pointed out that this is
3782 STRONGLY DISCOURAGED from a robustness point of view:
3783 updating the environment in flash makes it always
3784 necessary to erase the WHOLE sector. If something goes
3785 wrong before the contents has been restored from a copy in
3786 RAM, your target system will be dead.
3788 - CONFIG_ENV_ADDR_REDUND
3789 CONFIG_ENV_SIZE_REDUND
3791 These settings describe a second storage area used to hold
3792 a redundant copy of the environment data, so that there is
3793 a valid backup copy in case there is a power failure during
3794 a "saveenv" operation.
3796 BE CAREFUL! Any changes to the flash layout, and some changes to the
3797 source code will make it necessary to adapt <board>/u-boot.lds*
3801 - CONFIG_ENV_IS_IN_NVRAM:
3803 Define this if you have some non-volatile memory device
3804 (NVRAM, battery buffered SRAM) which you want to use for the
3810 These two #defines are used to determine the memory area you
3811 want to use for environment. It is assumed that this memory
3812 can just be read and written to, without any special
3815 BE CAREFUL! The first access to the environment happens quite early
3816 in U-Boot initalization (when we try to get the setting of for the
3817 console baudrate). You *MUST* have mapped your NVRAM area then, or
3820 Please note that even with NVRAM we still use a copy of the
3821 environment in RAM: we could work on NVRAM directly, but we want to
3822 keep settings there always unmodified except somebody uses "saveenv"
3823 to save the current settings.
3826 - CONFIG_ENV_IS_IN_EEPROM:
3828 Use this if you have an EEPROM or similar serial access
3829 device and a driver for it.
3831 - CONFIG_ENV_OFFSET:
3834 These two #defines specify the offset and size of the
3835 environment area within the total memory of your EEPROM.
3837 - CONFIG_SYS_I2C_EEPROM_ADDR:
3838 If defined, specified the chip address of the EEPROM device.
3839 The default address is zero.
3841 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3842 If defined, the number of bits used to address bytes in a
3843 single page in the EEPROM device. A 64 byte page, for example
3844 would require six bits.
3846 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3847 If defined, the number of milliseconds to delay between
3848 page writes. The default is zero milliseconds.
3850 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3851 The length in bytes of the EEPROM memory array address. Note
3852 that this is NOT the chip address length!
3854 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3855 EEPROM chips that implement "address overflow" are ones
3856 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3857 address and the extra bits end up in the "chip address" bit
3858 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3861 Note that we consider the length of the address field to
3862 still be one byte because the extra address bits are hidden
3863 in the chip address.
3865 - CONFIG_SYS_EEPROM_SIZE:
3866 The size in bytes of the EEPROM device.
3868 - CONFIG_ENV_EEPROM_IS_ON_I2C
3869 define this, if you have I2C and SPI activated, and your
3870 EEPROM, which holds the environment, is on the I2C bus.
3872 - CONFIG_I2C_ENV_EEPROM_BUS
3873 if you have an Environment on an EEPROM reached over
3874 I2C muxes, you can define here, how to reach this
3875 EEPROM. For example:
3877 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3879 EEPROM which holds the environment, is reached over
3880 a pca9547 i2c mux with address 0x70, channel 3.
3882 - CONFIG_ENV_IS_IN_DATAFLASH:
3884 Define this if you have a DataFlash memory device which you
3885 want to use for the environment.
3887 - CONFIG_ENV_OFFSET:
3891 These three #defines specify the offset and size of the
3892 environment area within the total memory of your DataFlash placed
3893 at the specified address.
3895 - CONFIG_ENV_IS_IN_REMOTE:
3897 Define this if you have a remote memory space which you
3898 want to use for the local device's environment.
3903 These two #defines specify the address and size of the
3904 environment area within the remote memory space. The
3905 local device can get the environment from remote memory
3906 space by SRIO or PCIE links.
3908 BE CAREFUL! For some special cases, the local device can not use
3909 "saveenv" command. For example, the local device will get the
3910 environment stored in a remote NOR flash by SRIO or PCIE link,
3911 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3913 - CONFIG_ENV_IS_IN_NAND:
3915 Define this if you have a NAND device which you want to use
3916 for the environment.
3918 - CONFIG_ENV_OFFSET:
3921 These two #defines specify the offset and size of the environment
3922 area within the first NAND device. CONFIG_ENV_OFFSET must be
3923 aligned to an erase block boundary.
3925 - CONFIG_ENV_OFFSET_REDUND (optional):
3927 This setting describes a second storage area of CONFIG_ENV_SIZE
3928 size used to hold a redundant copy of the environment data, so
3929 that there is a valid backup copy in case there is a power failure
3930 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3931 aligned to an erase block boundary.
3933 - CONFIG_ENV_RANGE (optional):
3935 Specifies the length of the region in which the environment
3936 can be written. This should be a multiple of the NAND device's
3937 block size. Specifying a range with more erase blocks than
3938 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3939 the range to be avoided.
3941 - CONFIG_ENV_OFFSET_OOB (optional):
3943 Enables support for dynamically retrieving the offset of the
3944 environment from block zero's out-of-band data. The
3945 "nand env.oob" command can be used to record this offset.
3946 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3947 using CONFIG_ENV_OFFSET_OOB.
3949 - CONFIG_NAND_ENV_DST
3951 Defines address in RAM to which the nand_spl code should copy the
3952 environment. If redundant environment is used, it will be copied to
3953 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3955 - CONFIG_ENV_IS_IN_UBI:
3957 Define this if you have an UBI volume that you want to use for the
3958 environment. This has the benefit of wear-leveling the environment
3959 accesses, which is important on NAND.
3961 - CONFIG_ENV_UBI_PART:
3963 Define this to a string that is the mtd partition containing the UBI.
3965 - CONFIG_ENV_UBI_VOLUME:
3967 Define this to the name of the volume that you want to store the
3970 - CONFIG_ENV_UBI_VOLUME_REDUND:
3972 Define this to the name of another volume to store a second copy of
3973 the environment in. This will enable redundant environments in UBI.
3974 It is assumed that both volumes are in the same MTD partition.
3976 - CONFIG_UBI_SILENCE_MSG
3977 - CONFIG_UBIFS_SILENCE_MSG
3979 You will probably want to define these to avoid a really noisy system
3980 when storing the env in UBI.
3982 - CONFIG_ENV_IS_IN_MMC:
3984 Define this if you have an MMC device which you want to use for the
3987 - CONFIG_SYS_MMC_ENV_DEV:
3989 Specifies which MMC device the environment is stored in.
3991 - CONFIG_SYS_MMC_ENV_PART (optional):
3993 Specifies which MMC partition the environment is stored in. If not
3994 set, defaults to partition 0, the user area. Common values might be
3995 1 (first MMC boot partition), 2 (second MMC boot partition).
3997 - CONFIG_ENV_OFFSET:
4000 These two #defines specify the offset and size of the environment
4001 area within the specified MMC device.
4003 If offset is positive (the usual case), it is treated as relative to
4004 the start of the MMC partition. If offset is negative, it is treated
4005 as relative to the end of the MMC partition. This can be useful if
4006 your board may be fitted with different MMC devices, which have
4007 different sizes for the MMC partitions, and you always want the
4008 environment placed at the very end of the partition, to leave the
4009 maximum possible space before it, to store other data.
4011 These two values are in units of bytes, but must be aligned to an
4012 MMC sector boundary.
4014 - CONFIG_ENV_OFFSET_REDUND (optional):
4016 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4017 hold a redundant copy of the environment data. This provides a
4018 valid backup copy in case the other copy is corrupted, e.g. due
4019 to a power failure during a "saveenv" operation.
4021 This value may also be positive or negative; this is handled in the
4022 same way as CONFIG_ENV_OFFSET.
4024 This value is also in units of bytes, but must also be aligned to
4025 an MMC sector boundary.
4027 - CONFIG_ENV_SIZE_REDUND (optional):
4029 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4030 set. If this value is set, it must be set to the same value as
4033 - CONFIG_SYS_SPI_INIT_OFFSET
4035 Defines offset to the initial SPI buffer area in DPRAM. The
4036 area is used at an early stage (ROM part) if the environment
4037 is configured to reside in the SPI EEPROM: We need a 520 byte
4038 scratch DPRAM area. It is used between the two initialization
4039 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4040 to be a good choice since it makes it far enough from the
4041 start of the data area as well as from the stack pointer.
4043 Please note that the environment is read-only until the monitor
4044 has been relocated to RAM and a RAM copy of the environment has been
4045 created; also, when using EEPROM you will have to use getenv_f()
4046 until then to read environment variables.
4048 The environment is protected by a CRC32 checksum. Before the monitor
4049 is relocated into RAM, as a result of a bad CRC you will be working
4050 with the compiled-in default environment - *silently*!!! [This is
4051 necessary, because the first environment variable we need is the
4052 "baudrate" setting for the console - if we have a bad CRC, we don't
4053 have any device yet where we could complain.]
4055 Note: once the monitor has been relocated, then it will complain if
4056 the default environment is used; a new CRC is computed as soon as you
4057 use the "saveenv" command to store a valid environment.
4059 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4060 Echo the inverted Ethernet link state to the fault LED.
4062 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4063 also needs to be defined.
4065 - CONFIG_SYS_FAULT_MII_ADDR:
4066 MII address of the PHY to check for the Ethernet link state.
4068 - CONFIG_NS16550_MIN_FUNCTIONS:
4069 Define this if you desire to only have use of the NS16550_init
4070 and NS16550_putc functions for the serial driver located at
4071 drivers/serial/ns16550.c. This option is useful for saving
4072 space for already greatly restricted images, including but not
4073 limited to NAND_SPL configurations.
4075 - CONFIG_DISPLAY_BOARDINFO
4076 Display information about the board that U-Boot is running on
4077 when U-Boot starts up. The board function checkboard() is called
4080 - CONFIG_DISPLAY_BOARDINFO_LATE
4081 Similar to the previous option, but display this information
4082 later, once stdio is running and output goes to the LCD, if
4085 Low Level (hardware related) configuration options:
4086 ---------------------------------------------------
4088 - CONFIG_SYS_CACHELINE_SIZE:
4089 Cache Line Size of the CPU.
4091 - CONFIG_SYS_DEFAULT_IMMR:
4092 Default address of the IMMR after system reset.
4094 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4095 and RPXsuper) to be able to adjust the position of
4096 the IMMR register after a reset.
4098 - CONFIG_SYS_CCSRBAR_DEFAULT:
4099 Default (power-on reset) physical address of CCSR on Freescale
4102 - CONFIG_SYS_CCSRBAR:
4103 Virtual address of CCSR. On a 32-bit build, this is typically
4104 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4106 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4107 for cross-platform code that uses that macro instead.
4109 - CONFIG_SYS_CCSRBAR_PHYS:
4110 Physical address of CCSR. CCSR can be relocated to a new
4111 physical address, if desired. In this case, this macro should
4112 be set to that address. Otherwise, it should be set to the
4113 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4114 is typically relocated on 36-bit builds. It is recommended
4115 that this macro be defined via the _HIGH and _LOW macros:
4117 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4118 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4120 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4121 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4122 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4123 used in assembly code, so it must not contain typecasts or
4124 integer size suffixes (e.g. "ULL").
4126 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4127 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4128 used in assembly code, so it must not contain typecasts or
4129 integer size suffixes (e.g. "ULL").
4131 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4132 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4133 forced to a value that ensures that CCSR is not relocated.
4135 - Floppy Disk Support:
4136 CONFIG_SYS_FDC_DRIVE_NUMBER
4138 the default drive number (default value 0)
4140 CONFIG_SYS_ISA_IO_STRIDE
4142 defines the spacing between FDC chipset registers
4145 CONFIG_SYS_ISA_IO_OFFSET
4147 defines the offset of register from address. It
4148 depends on which part of the data bus is connected to
4149 the FDC chipset. (default value 0)
4151 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4152 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4155 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4156 fdc_hw_init() is called at the beginning of the FDC
4157 setup. fdc_hw_init() must be provided by the board
4158 source code. It is used to make hardware dependant
4162 Most IDE controllers were designed to be connected with PCI
4163 interface. Only few of them were designed for AHB interface.
4164 When software is doing ATA command and data transfer to
4165 IDE devices through IDE-AHB controller, some additional
4166 registers accessing to these kind of IDE-AHB controller
4169 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4170 DO NOT CHANGE unless you know exactly what you're
4171 doing! (11-4) [MPC8xx/82xx systems only]
4173 - CONFIG_SYS_INIT_RAM_ADDR:
4175 Start address of memory area that can be used for
4176 initial data and stack; please note that this must be
4177 writable memory that is working WITHOUT special
4178 initialization, i. e. you CANNOT use normal RAM which
4179 will become available only after programming the
4180 memory controller and running certain initialization
4183 U-Boot uses the following memory types:
4184 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4185 - MPC824X: data cache
4186 - PPC4xx: data cache
4188 - CONFIG_SYS_GBL_DATA_OFFSET:
4190 Offset of the initial data structure in the memory
4191 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4192 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4193 data is located at the end of the available space
4194 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4195 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4196 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4197 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4200 On the MPC824X (or other systems that use the data
4201 cache for initial memory) the address chosen for
4202 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4203 point to an otherwise UNUSED address space between
4204 the top of RAM and the start of the PCI space.
4206 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4208 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4210 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4212 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4214 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4216 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4218 - CONFIG_SYS_OR_TIMING_SDRAM:
4221 - CONFIG_SYS_MAMR_PTA:
4222 periodic timer for refresh
4224 - CONFIG_SYS_DER: Debug Event Register (37-47)
4226 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4227 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4228 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4229 CONFIG_SYS_BR1_PRELIM:
4230 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4232 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4233 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4234 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4235 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4237 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4238 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4239 Machine Mode Register and Memory Periodic Timer
4240 Prescaler definitions (SDRAM timing)
4242 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4243 enable I2C microcode relocation patch (MPC8xx);
4244 define relocation offset in DPRAM [DSP2]
4246 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4247 enable SMC microcode relocation patch (MPC8xx);
4248 define relocation offset in DPRAM [SMC1]
4250 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4251 enable SPI microcode relocation patch (MPC8xx);
4252 define relocation offset in DPRAM [SCC4]
4254 - CONFIG_SYS_USE_OSCCLK:
4255 Use OSCM clock mode on MBX8xx board. Be careful,
4256 wrong setting might damage your board. Read
4257 doc/README.MBX before setting this variable!
4259 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4260 Offset of the bootmode word in DPRAM used by post
4261 (Power On Self Tests). This definition overrides
4262 #define'd default value in commproc.h resp.
4265 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4266 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4267 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4268 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4269 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4270 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4271 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4272 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4273 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4275 - CONFIG_PCI_DISABLE_PCIE:
4276 Disable PCI-Express on systems where it is supported but not
4279 - CONFIG_PCI_ENUM_ONLY
4280 Only scan through and get the devices on the busses.
4281 Don't do any setup work, presumably because someone or
4282 something has already done it, and we don't need to do it
4283 a second time. Useful for platforms that are pre-booted
4284 by coreboot or similar.
4286 - CONFIG_PCI_INDIRECT_BRIDGE:
4287 Enable support for indirect PCI bridges.
4290 Chip has SRIO or not
4293 Board has SRIO 1 port available
4296 Board has SRIO 2 port available
4298 - CONFIG_SRIO_PCIE_BOOT_MASTER
4299 Board can support master function for Boot from SRIO and PCIE
4301 - CONFIG_SYS_SRIOn_MEM_VIRT:
4302 Virtual Address of SRIO port 'n' memory region
4304 - CONFIG_SYS_SRIOn_MEM_PHYS:
4305 Physical Address of SRIO port 'n' memory region
4307 - CONFIG_SYS_SRIOn_MEM_SIZE:
4308 Size of SRIO port 'n' memory region
4310 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4311 Defined to tell the NAND controller that the NAND chip is using
4313 Not all NAND drivers use this symbol.
4314 Example of drivers that use it:
4315 - drivers/mtd/nand/ndfc.c
4316 - drivers/mtd/nand/mxc_nand.c
4318 - CONFIG_SYS_NDFC_EBC0_CFG
4319 Sets the EBC0_CFG register for the NDFC. If not defined
4320 a default value will be used.
4323 Get DDR timing information from an I2C EEPROM. Common
4324 with pluggable memory modules such as SODIMMs
4327 I2C address of the SPD EEPROM
4329 - CONFIG_SYS_SPD_BUS_NUM
4330 If SPD EEPROM is on an I2C bus other than the first
4331 one, specify here. Note that the value must resolve
4332 to something your driver can deal with.
4334 - CONFIG_SYS_DDR_RAW_TIMING
4335 Get DDR timing information from other than SPD. Common with
4336 soldered DDR chips onboard without SPD. DDR raw timing
4337 parameters are extracted from datasheet and hard-coded into
4338 header files or board specific files.
4340 - CONFIG_FSL_DDR_INTERACTIVE
4341 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4343 - CONFIG_SYS_83XX_DDR_USES_CS0
4344 Only for 83xx systems. If specified, then DDR should
4345 be configured using CS0 and CS1 instead of CS2 and CS3.
4347 - CONFIG_ETHER_ON_FEC[12]
4348 Define to enable FEC[12] on a 8xx series processor.
4350 - CONFIG_FEC[12]_PHY
4351 Define to the hardcoded PHY address which corresponds
4352 to the given FEC; i. e.
4353 #define CONFIG_FEC1_PHY 4
4354 means that the PHY with address 4 is connected to FEC1
4356 When set to -1, means to probe for first available.
4358 - CONFIG_FEC[12]_PHY_NORXERR
4359 The PHY does not have a RXERR line (RMII only).
4360 (so program the FEC to ignore it).
4363 Enable RMII mode for all FECs.
4364 Note that this is a global option, we can't
4365 have one FEC in standard MII mode and another in RMII mode.
4367 - CONFIG_CRC32_VERIFY
4368 Add a verify option to the crc32 command.
4371 => crc32 -v <address> <count> <crc32>
4373 Where address/count indicate a memory area
4374 and crc32 is the correct crc32 which the
4378 Add the "loopw" memory command. This only takes effect if
4379 the memory commands are activated globally (CONFIG_CMD_MEM).
4382 Add the "mdc" and "mwc" memory commands. These are cyclic
4387 This command will print 4 bytes (10,11,12,13) each 500 ms.
4389 => mwc.l 100 12345678 10
4390 This command will write 12345678 to address 100 all 10 ms.
4392 This only takes effect if the memory commands are activated
4393 globally (CONFIG_CMD_MEM).
4395 - CONFIG_SKIP_LOWLEVEL_INIT
4396 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4397 low level initializations (like setting up the memory
4398 controller) are omitted and/or U-Boot does not
4399 relocate itself into RAM.
4401 Normally this variable MUST NOT be defined. The only
4402 exception is when U-Boot is loaded (to RAM) by some
4403 other boot loader or by a debugger which performs
4404 these initializations itself.
4407 Modifies the behaviour of start.S when compiling a loader
4408 that is executed before the actual U-Boot. E.g. when
4409 compiling a NAND SPL.
4412 Modifies the behaviour of start.S when compiling a loader
4413 that is executed after the SPL and before the actual U-Boot.
4414 It is loaded by the SPL.
4416 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4417 Only for 85xx systems. If this variable is specified, the section
4418 .resetvec is not kept and the section .bootpg is placed in the
4419 previous 4k of the .text section.
4421 - CONFIG_ARCH_MAP_SYSMEM
4422 Generally U-Boot (and in particular the md command) uses
4423 effective address. It is therefore not necessary to regard
4424 U-Boot address as virtual addresses that need to be translated
4425 to physical addresses. However, sandbox requires this, since
4426 it maintains its own little RAM buffer which contains all
4427 addressable memory. This option causes some memory accesses
4428 to be mapped through map_sysmem() / unmap_sysmem().
4430 - CONFIG_USE_ARCH_MEMCPY
4431 CONFIG_USE_ARCH_MEMSET
4432 If these options are used a optimized version of memcpy/memset will
4433 be used if available. These functions may be faster under some
4434 conditions but may increase the binary size.
4436 - CONFIG_X86_RESET_VECTOR
4437 If defined, the x86 reset vector code is included. This is not
4438 needed when U-Boot is running from Coreboot.
4441 Defines the MPU clock speed (in MHz).
4443 NOTE : currently only supported on AM335x platforms.
4445 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4446 Enables the RTC32K OSC on AM33xx based plattforms
4448 Freescale QE/FMAN Firmware Support:
4449 -----------------------------------
4451 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4452 loading of "firmware", which is encoded in the QE firmware binary format.
4453 This firmware often needs to be loaded during U-Boot booting, so macros
4454 are used to identify the storage device (NOR flash, SPI, etc) and the address
4457 - CONFIG_SYS_QE_FMAN_FW_ADDR
4458 The address in the storage device where the firmware is located. The
4459 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4462 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4463 The maximum possible size of the firmware. The firmware binary format
4464 has a field that specifies the actual size of the firmware, but it
4465 might not be possible to read any part of the firmware unless some
4466 local storage is allocated to hold the entire firmware first.
4468 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4469 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4470 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4471 virtual address in NOR flash.
4473 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4474 Specifies that QE/FMAN firmware is located in NAND flash.
4475 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4477 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4478 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4479 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4481 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4482 Specifies that QE/FMAN firmware is located on the primary SPI
4483 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4485 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4486 Specifies that QE/FMAN firmware is located in the remote (master)
4487 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4488 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4489 window->master inbound window->master LAW->the ucode address in
4490 master's memory space.
4492 Building the Software:
4493 ======================
4495 Building U-Boot has been tested in several native build environments
4496 and in many different cross environments. Of course we cannot support
4497 all possibly existing versions of cross development tools in all
4498 (potentially obsolete) versions. In case of tool chain problems we
4499 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4500 which is extensively used to build and test U-Boot.
4502 If you are not using a native environment, it is assumed that you
4503 have GNU cross compiling tools available in your path. In this case,
4504 you must set the environment variable CROSS_COMPILE in your shell.
4505 Note that no changes to the Makefile or any other source files are
4506 necessary. For example using the ELDK on a 4xx CPU, please enter:
4508 $ CROSS_COMPILE=ppc_4xx-
4509 $ export CROSS_COMPILE
4511 Note: If you wish to generate Windows versions of the utilities in
4512 the tools directory you can use the MinGW toolchain
4513 (http://www.mingw.org). Set your HOST tools to the MinGW
4514 toolchain and execute 'make tools'. For example:
4516 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4518 Binaries such as tools/mkimage.exe will be created which can
4519 be executed on computers running Windows.
4521 U-Boot is intended to be simple to build. After installing the
4522 sources you must configure U-Boot for one specific board type. This
4527 where "NAME_config" is the name of one of the existing configu-
4528 rations; see boards.cfg for supported names.
4530 Note: for some board special configuration names may exist; check if
4531 additional information is available from the board vendor; for
4532 instance, the TQM823L systems are available without (standard)
4533 or with LCD support. You can select such additional "features"
4534 when choosing the configuration, i. e.
4537 - will configure for a plain TQM823L, i. e. no LCD support
4539 make TQM823L_LCD_config
4540 - will configure for a TQM823L with U-Boot console on LCD
4545 Finally, type "make all", and you should get some working U-Boot
4546 images ready for download to / installation on your system:
4548 - "u-boot.bin" is a raw binary image
4549 - "u-boot" is an image in ELF binary format
4550 - "u-boot.srec" is in Motorola S-Record format
4552 By default the build is performed locally and the objects are saved
4553 in the source directory. One of the two methods can be used to change
4554 this behavior and build U-Boot to some external directory:
4556 1. Add O= to the make command line invocations:
4558 make O=/tmp/build distclean
4559 make O=/tmp/build NAME_config
4560 make O=/tmp/build all
4562 2. Set environment variable BUILD_DIR to point to the desired location:
4564 export BUILD_DIR=/tmp/build
4569 Note that the command line "O=" setting overrides the BUILD_DIR environment
4573 Please be aware that the Makefiles assume you are using GNU make, so
4574 for instance on NetBSD you might need to use "gmake" instead of
4578 If the system board that you have is not listed, then you will need
4579 to port U-Boot to your hardware platform. To do this, follow these
4582 1. Add a new configuration option for your board to the toplevel
4583 "boards.cfg" file, using the existing entries as examples.
4584 Follow the instructions there to keep the boards in order.
4585 2. Create a new directory to hold your board specific code. Add any
4586 files you need. In your board directory, you will need at least
4587 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4588 3. Create a new configuration file "include/configs/<board>.h" for
4590 3. If you're porting U-Boot to a new CPU, then also create a new
4591 directory to hold your CPU specific code. Add any files you need.
4592 4. Run "make <board>_config" with your new name.
4593 5. Type "make", and you should get a working "u-boot.srec" file
4594 to be installed on your target system.
4595 6. Debug and solve any problems that might arise.
4596 [Of course, this last step is much harder than it sounds.]
4599 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4600 ==============================================================
4602 If you have modified U-Boot sources (for instance added a new board
4603 or support for new devices, a new CPU, etc.) you are expected to
4604 provide feedback to the other developers. The feedback normally takes
4605 the form of a "patch", i. e. a context diff against a certain (latest
4606 official or latest in the git repository) version of U-Boot sources.
4608 But before you submit such a patch, please verify that your modifi-
4609 cation did not break existing code. At least make sure that *ALL* of
4610 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4611 just run the "MAKEALL" script, which will configure and build U-Boot
4612 for ALL supported system. Be warned, this will take a while. You can
4613 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4614 environment variable to the script, i. e. to use the ELDK cross tools
4617 CROSS_COMPILE=ppc_8xx- MAKEALL
4619 or to build on a native PowerPC system you can type
4621 CROSS_COMPILE=' ' MAKEALL
4623 When using the MAKEALL script, the default behaviour is to build
4624 U-Boot in the source directory. This location can be changed by
4625 setting the BUILD_DIR environment variable. Also, for each target
4626 built, the MAKEALL script saves two log files (<target>.ERR and
4627 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4628 location can be changed by setting the MAKEALL_LOGDIR environment
4629 variable. For example:
4631 export BUILD_DIR=/tmp/build
4632 export MAKEALL_LOGDIR=/tmp/log
4633 CROSS_COMPILE=ppc_8xx- MAKEALL
4635 With the above settings build objects are saved in the /tmp/build,
4636 log files are saved in the /tmp/log and the source tree remains clean
4637 during the whole build process.
4640 See also "U-Boot Porting Guide" below.
4643 Monitor Commands - Overview:
4644 ============================
4646 go - start application at address 'addr'
4647 run - run commands in an environment variable
4648 bootm - boot application image from memory
4649 bootp - boot image via network using BootP/TFTP protocol
4650 bootz - boot zImage from memory
4651 tftpboot- boot image via network using TFTP protocol
4652 and env variables "ipaddr" and "serverip"
4653 (and eventually "gatewayip")
4654 tftpput - upload a file via network using TFTP protocol
4655 rarpboot- boot image via network using RARP/TFTP protocol
4656 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4657 loads - load S-Record file over serial line
4658 loadb - load binary file over serial line (kermit mode)
4660 mm - memory modify (auto-incrementing)
4661 nm - memory modify (constant address)
4662 mw - memory write (fill)
4664 cmp - memory compare
4665 crc32 - checksum calculation
4666 i2c - I2C sub-system
4667 sspi - SPI utility commands
4668 base - print or set address offset
4669 printenv- print environment variables
4670 setenv - set environment variables
4671 saveenv - save environment variables to persistent storage
4672 protect - enable or disable FLASH write protection
4673 erase - erase FLASH memory
4674 flinfo - print FLASH memory information
4675 nand - NAND memory operations (see doc/README.nand)
4676 bdinfo - print Board Info structure
4677 iminfo - print header information for application image
4678 coninfo - print console devices and informations
4679 ide - IDE sub-system
4680 loop - infinite loop on address range
4681 loopw - infinite write loop on address range
4682 mtest - simple RAM test
4683 icache - enable or disable instruction cache
4684 dcache - enable or disable data cache
4685 reset - Perform RESET of the CPU
4686 echo - echo args to console
4687 version - print monitor version
4688 help - print online help
4689 ? - alias for 'help'
4692 Monitor Commands - Detailed Description:
4693 ========================================
4697 For now: just type "help <command>".
4700 Environment Variables:
4701 ======================
4703 U-Boot supports user configuration using Environment Variables which
4704 can be made persistent by saving to Flash memory.
4706 Environment Variables are set using "setenv", printed using
4707 "printenv", and saved to Flash using "saveenv". Using "setenv"
4708 without a value can be used to delete a variable from the
4709 environment. As long as you don't save the environment you are
4710 working with an in-memory copy. In case the Flash area containing the
4711 environment is erased by accident, a default environment is provided.
4713 Some configuration options can be set using Environment Variables.
4715 List of environment variables (most likely not complete):
4717 baudrate - see CONFIG_BAUDRATE
4719 bootdelay - see CONFIG_BOOTDELAY
4721 bootcmd - see CONFIG_BOOTCOMMAND
4723 bootargs - Boot arguments when booting an RTOS image
4725 bootfile - Name of the image to load with TFTP
4727 bootm_low - Memory range available for image processing in the bootm
4728 command can be restricted. This variable is given as
4729 a hexadecimal number and defines lowest address allowed
4730 for use by the bootm command. See also "bootm_size"
4731 environment variable. Address defined by "bootm_low" is
4732 also the base of the initial memory mapping for the Linux
4733 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4736 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4737 This variable is given as a hexadecimal number and it
4738 defines the size of the memory region starting at base
4739 address bootm_low that is accessible by the Linux kernel
4740 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4741 as the default value if it is defined, and bootm_size is
4744 bootm_size - Memory range available for image processing in the bootm
4745 command can be restricted. This variable is given as
4746 a hexadecimal number and defines the size of the region
4747 allowed for use by the bootm command. See also "bootm_low"
4748 environment variable.
4750 updatefile - Location of the software update file on a TFTP server, used
4751 by the automatic software update feature. Please refer to
4752 documentation in doc/README.update for more details.
4754 autoload - if set to "no" (any string beginning with 'n'),
4755 "bootp" will just load perform a lookup of the
4756 configuration from the BOOTP server, but not try to
4757 load any image using TFTP
4759 autostart - if set to "yes", an image loaded using the "bootp",
4760 "rarpboot", "tftpboot" or "diskboot" commands will
4761 be automatically started (by internally calling
4764 If set to "no", a standalone image passed to the
4765 "bootm" command will be copied to the load address
4766 (and eventually uncompressed), but NOT be started.
4767 This can be used to load and uncompress arbitrary
4770 fdt_high - if set this restricts the maximum address that the
4771 flattened device tree will be copied into upon boot.
4772 For example, if you have a system with 1 GB memory
4773 at physical address 0x10000000, while Linux kernel
4774 only recognizes the first 704 MB as low memory, you
4775 may need to set fdt_high as 0x3C000000 to have the
4776 device tree blob be copied to the maximum address
4777 of the 704 MB low memory, so that Linux kernel can
4778 access it during the boot procedure.
4780 If this is set to the special value 0xFFFFFFFF then
4781 the fdt will not be copied at all on boot. For this
4782 to work it must reside in writable memory, have
4783 sufficient padding on the end of it for u-boot to
4784 add the information it needs into it, and the memory
4785 must be accessible by the kernel.
4787 fdtcontroladdr- if set this is the address of the control flattened
4788 device tree used by U-Boot when CONFIG_OF_CONTROL is
4791 i2cfast - (PPC405GP|PPC405EP only)
4792 if set to 'y' configures Linux I2C driver for fast
4793 mode (400kHZ). This environment variable is used in
4794 initialization code. So, for changes to be effective
4795 it must be saved and board must be reset.
4797 initrd_high - restrict positioning of initrd images:
4798 If this variable is not set, initrd images will be
4799 copied to the highest possible address in RAM; this
4800 is usually what you want since it allows for
4801 maximum initrd size. If for some reason you want to
4802 make sure that the initrd image is loaded below the
4803 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4804 variable to a value of "no" or "off" or "0".
4805 Alternatively, you can set it to a maximum upper
4806 address to use (U-Boot will still check that it
4807 does not overwrite the U-Boot stack and data).
4809 For instance, when you have a system with 16 MB
4810 RAM, and want to reserve 4 MB from use by Linux,
4811 you can do this by adding "mem=12M" to the value of
4812 the "bootargs" variable. However, now you must make
4813 sure that the initrd image is placed in the first
4814 12 MB as well - this can be done with
4816 setenv initrd_high 00c00000
4818 If you set initrd_high to 0xFFFFFFFF, this is an
4819 indication to U-Boot that all addresses are legal
4820 for the Linux kernel, including addresses in flash
4821 memory. In this case U-Boot will NOT COPY the
4822 ramdisk at all. This may be useful to reduce the
4823 boot time on your system, but requires that this
4824 feature is supported by your Linux kernel.
4826 ipaddr - IP address; needed for tftpboot command
4828 loadaddr - Default load address for commands like "bootp",
4829 "rarpboot", "tftpboot", "loadb" or "diskboot"
4831 loads_echo - see CONFIG_LOADS_ECHO
4833 serverip - TFTP server IP address; needed for tftpboot command
4835 bootretry - see CONFIG_BOOT_RETRY_TIME
4837 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4839 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4841 ethprime - controls which interface is used first.
4843 ethact - controls which interface is currently active.
4844 For example you can do the following
4846 => setenv ethact FEC
4847 => ping 192.168.0.1 # traffic sent on FEC
4848 => setenv ethact SCC
4849 => ping 10.0.0.1 # traffic sent on SCC
4851 ethrotate - When set to "no" U-Boot does not go through all
4852 available network interfaces.
4853 It just stays at the currently selected interface.
4855 netretry - When set to "no" each network operation will
4856 either succeed or fail without retrying.
4857 When set to "once" the network operation will
4858 fail when all the available network interfaces
4859 are tried once without success.
4860 Useful on scripts which control the retry operation
4863 npe_ucode - set load address for the NPE microcode
4865 silent_linux - If set then linux will be told to boot silently, by
4866 changing the console to be empty. If "yes" it will be
4867 made silent. If "no" it will not be made silent. If
4868 unset, then it will be made silent if the U-Boot console
4871 tftpsrcport - If this is set, the value is used for TFTP's
4874 tftpdstport - If this is set, the value is used for TFTP's UDP
4875 destination port instead of the Well Know Port 69.
4877 tftpblocksize - Block size to use for TFTP transfers; if not set,
4878 we use the TFTP server's default block size
4880 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4881 seconds, minimum value is 1000 = 1 second). Defines
4882 when a packet is considered to be lost so it has to
4883 be retransmitted. The default is 5000 = 5 seconds.
4884 Lowering this value may make downloads succeed
4885 faster in networks with high packet loss rates or
4886 with unreliable TFTP servers.
4888 vlan - When set to a value < 4095 the traffic over
4889 Ethernet is encapsulated/received over 802.1q
4892 The following image location variables contain the location of images
4893 used in booting. The "Image" column gives the role of the image and is
4894 not an environment variable name. The other columns are environment
4895 variable names. "File Name" gives the name of the file on a TFTP
4896 server, "RAM Address" gives the location in RAM the image will be
4897 loaded to, and "Flash Location" gives the image's address in NOR
4898 flash or offset in NAND flash.
4900 *Note* - these variables don't have to be defined for all boards, some
4901 boards currenlty use other variables for these purposes, and some
4902 boards use these variables for other purposes.
4904 Image File Name RAM Address Flash Location
4905 ----- --------- ----------- --------------
4906 u-boot u-boot u-boot_addr_r u-boot_addr
4907 Linux kernel bootfile kernel_addr_r kernel_addr
4908 device tree blob fdtfile fdt_addr_r fdt_addr
4909 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4911 The following environment variables may be used and automatically
4912 updated by the network boot commands ("bootp" and "rarpboot"),
4913 depending the information provided by your boot server:
4915 bootfile - see above
4916 dnsip - IP address of your Domain Name Server
4917 dnsip2 - IP address of your secondary Domain Name Server
4918 gatewayip - IP address of the Gateway (Router) to use
4919 hostname - Target hostname
4921 netmask - Subnet Mask
4922 rootpath - Pathname of the root filesystem on the NFS server
4923 serverip - see above
4926 There are two special Environment Variables:
4928 serial# - contains hardware identification information such
4929 as type string and/or serial number
4930 ethaddr - Ethernet address
4932 These variables can be set only once (usually during manufacturing of
4933 the board). U-Boot refuses to delete or overwrite these variables
4934 once they have been set once.
4937 Further special Environment Variables:
4939 ver - Contains the U-Boot version string as printed
4940 with the "version" command. This variable is
4941 readonly (see CONFIG_VERSION_VARIABLE).
4944 Please note that changes to some configuration parameters may take
4945 only effect after the next boot (yes, that's just like Windoze :-).
4948 Callback functions for environment variables:
4949 ---------------------------------------------
4951 For some environment variables, the behavior of u-boot needs to change
4952 when their values are changed. This functionailty allows functions to
4953 be associated with arbitrary variables. On creation, overwrite, or
4954 deletion, the callback will provide the opportunity for some side
4955 effect to happen or for the change to be rejected.
4957 The callbacks are named and associated with a function using the
4958 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4960 These callbacks are associated with variables in one of two ways. The
4961 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4962 in the board configuration to a string that defines a list of
4963 associations. The list must be in the following format:
4965 entry = variable_name[:callback_name]
4968 If the callback name is not specified, then the callback is deleted.
4969 Spaces are also allowed anywhere in the list.
4971 Callbacks can also be associated by defining the ".callbacks" variable
4972 with the same list format above. Any association in ".callbacks" will
4973 override any association in the static list. You can define
4974 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4975 ".callbacks" envirnoment variable in the default or embedded environment.
4978 Command Line Parsing:
4979 =====================
4981 There are two different command line parsers available with U-Boot:
4982 the old "simple" one, and the much more powerful "hush" shell:
4984 Old, simple command line parser:
4985 --------------------------------
4987 - supports environment variables (through setenv / saveenv commands)
4988 - several commands on one line, separated by ';'
4989 - variable substitution using "... ${name} ..." syntax
4990 - special characters ('$', ';') can be escaped by prefixing with '\',
4992 setenv bootcmd bootm \${address}
4993 - You can also escape text by enclosing in single apostrophes, for example:
4994 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4999 - similar to Bourne shell, with control structures like
5000 if...then...else...fi, for...do...done; while...do...done,
5001 until...do...done, ...
5002 - supports environment ("global") variables (through setenv / saveenv
5003 commands) and local shell variables (through standard shell syntax
5004 "name=value"); only environment variables can be used with "run"
5010 (1) If a command line (or an environment variable executed by a "run"
5011 command) contains several commands separated by semicolon, and
5012 one of these commands fails, then the remaining commands will be
5015 (2) If you execute several variables with one call to run (i. e.
5016 calling run with a list of variables as arguments), any failing
5017 command will cause "run" to terminate, i. e. the remaining
5018 variables are not executed.
5020 Note for Redundant Ethernet Interfaces:
5021 =======================================
5023 Some boards come with redundant Ethernet interfaces; U-Boot supports
5024 such configurations and is capable of automatic selection of a
5025 "working" interface when needed. MAC assignment works as follows:
5027 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5028 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5029 "eth1addr" (=>eth1), "eth2addr", ...
5031 If the network interface stores some valid MAC address (for instance
5032 in SROM), this is used as default address if there is NO correspon-
5033 ding setting in the environment; if the corresponding environment
5034 variable is set, this overrides the settings in the card; that means:
5036 o If the SROM has a valid MAC address, and there is no address in the
5037 environment, the SROM's address is used.
5039 o If there is no valid address in the SROM, and a definition in the
5040 environment exists, then the value from the environment variable is
5043 o If both the SROM and the environment contain a MAC address, and
5044 both addresses are the same, this MAC address is used.
5046 o If both the SROM and the environment contain a MAC address, and the
5047 addresses differ, the value from the environment is used and a
5050 o If neither SROM nor the environment contain a MAC address, an error
5053 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5054 will be programmed into hardware as part of the initialization process. This
5055 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5056 The naming convention is as follows:
5057 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5062 U-Boot is capable of booting (and performing other auxiliary operations on)
5063 images in two formats:
5065 New uImage format (FIT)
5066 -----------------------
5068 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5069 to Flattened Device Tree). It allows the use of images with multiple
5070 components (several kernels, ramdisks, etc.), with contents protected by
5071 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5077 Old image format is based on binary files which can be basically anything,
5078 preceded by a special header; see the definitions in include/image.h for
5079 details; basically, the header defines the following image properties:
5081 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5082 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5083 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5084 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5086 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5087 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5088 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5089 * Compression Type (uncompressed, gzip, bzip2)
5095 The header is marked by a special Magic Number, and both the header
5096 and the data portions of the image are secured against corruption by
5103 Although U-Boot should support any OS or standalone application
5104 easily, the main focus has always been on Linux during the design of
5107 U-Boot includes many features that so far have been part of some
5108 special "boot loader" code within the Linux kernel. Also, any
5109 "initrd" images to be used are no longer part of one big Linux image;
5110 instead, kernel and "initrd" are separate images. This implementation
5111 serves several purposes:
5113 - the same features can be used for other OS or standalone
5114 applications (for instance: using compressed images to reduce the
5115 Flash memory footprint)
5117 - it becomes much easier to port new Linux kernel versions because
5118 lots of low-level, hardware dependent stuff are done by U-Boot
5120 - the same Linux kernel image can now be used with different "initrd"
5121 images; of course this also means that different kernel images can
5122 be run with the same "initrd". This makes testing easier (you don't
5123 have to build a new "zImage.initrd" Linux image when you just
5124 change a file in your "initrd"). Also, a field-upgrade of the
5125 software is easier now.
5131 Porting Linux to U-Boot based systems:
5132 ---------------------------------------
5134 U-Boot cannot save you from doing all the necessary modifications to
5135 configure the Linux device drivers for use with your target hardware
5136 (no, we don't intend to provide a full virtual machine interface to
5139 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5141 Just make sure your machine specific header file (for instance
5142 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5143 Information structure as we define in include/asm-<arch>/u-boot.h,
5144 and make sure that your definition of IMAP_ADDR uses the same value
5145 as your U-Boot configuration in CONFIG_SYS_IMMR.
5148 Configuring the Linux kernel:
5149 -----------------------------
5151 No specific requirements for U-Boot. Make sure you have some root
5152 device (initial ramdisk, NFS) for your target system.
5155 Building a Linux Image:
5156 -----------------------
5158 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5159 not used. If you use recent kernel source, a new build target
5160 "uImage" will exist which automatically builds an image usable by
5161 U-Boot. Most older kernels also have support for a "pImage" target,
5162 which was introduced for our predecessor project PPCBoot and uses a
5163 100% compatible format.
5172 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5173 encapsulate a compressed Linux kernel image with header information,
5174 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5176 * build a standard "vmlinux" kernel image (in ELF binary format):
5178 * convert the kernel into a raw binary image:
5180 ${CROSS_COMPILE}-objcopy -O binary \
5181 -R .note -R .comment \
5182 -S vmlinux linux.bin
5184 * compress the binary image:
5188 * package compressed binary image for U-Boot:
5190 mkimage -A ppc -O linux -T kernel -C gzip \
5191 -a 0 -e 0 -n "Linux Kernel Image" \
5192 -d linux.bin.gz uImage
5195 The "mkimage" tool can also be used to create ramdisk images for use
5196 with U-Boot, either separated from the Linux kernel image, or
5197 combined into one file. "mkimage" encapsulates the images with a 64
5198 byte header containing information about target architecture,
5199 operating system, image type, compression method, entry points, time
5200 stamp, CRC32 checksums, etc.
5202 "mkimage" can be called in two ways: to verify existing images and
5203 print the header information, or to build new images.
5205 In the first form (with "-l" option) mkimage lists the information
5206 contained in the header of an existing U-Boot image; this includes
5207 checksum verification:
5209 tools/mkimage -l image
5210 -l ==> list image header information
5212 The second form (with "-d" option) is used to build a U-Boot image
5213 from a "data file" which is used as image payload:
5215 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5216 -n name -d data_file image
5217 -A ==> set architecture to 'arch'
5218 -O ==> set operating system to 'os'
5219 -T ==> set image type to 'type'
5220 -C ==> set compression type 'comp'
5221 -a ==> set load address to 'addr' (hex)
5222 -e ==> set entry point to 'ep' (hex)
5223 -n ==> set image name to 'name'
5224 -d ==> use image data from 'datafile'
5226 Right now, all Linux kernels for PowerPC systems use the same load
5227 address (0x00000000), but the entry point address depends on the
5230 - 2.2.x kernels have the entry point at 0x0000000C,
5231 - 2.3.x and later kernels have the entry point at 0x00000000.
5233 So a typical call to build a U-Boot image would read:
5235 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5236 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5237 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5238 > examples/uImage.TQM850L
5239 Image Name: 2.4.4 kernel for TQM850L
5240 Created: Wed Jul 19 02:34:59 2000
5241 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5242 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5243 Load Address: 0x00000000
5244 Entry Point: 0x00000000
5246 To verify the contents of the image (or check for corruption):
5248 -> tools/mkimage -l examples/uImage.TQM850L
5249 Image Name: 2.4.4 kernel for TQM850L
5250 Created: Wed Jul 19 02:34:59 2000
5251 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5252 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5253 Load Address: 0x00000000
5254 Entry Point: 0x00000000
5256 NOTE: for embedded systems where boot time is critical you can trade
5257 speed for memory and install an UNCOMPRESSED image instead: this
5258 needs more space in Flash, but boots much faster since it does not
5259 need to be uncompressed:
5261 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5262 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5263 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5264 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5265 > examples/uImage.TQM850L-uncompressed
5266 Image Name: 2.4.4 kernel for TQM850L
5267 Created: Wed Jul 19 02:34:59 2000
5268 Image Type: PowerPC Linux Kernel Image (uncompressed)
5269 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5270 Load Address: 0x00000000
5271 Entry Point: 0x00000000
5274 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5275 when your kernel is intended to use an initial ramdisk:
5277 -> tools/mkimage -n 'Simple Ramdisk Image' \
5278 > -A ppc -O linux -T ramdisk -C gzip \
5279 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5280 Image Name: Simple Ramdisk Image
5281 Created: Wed Jan 12 14:01:50 2000
5282 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5283 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5284 Load Address: 0x00000000
5285 Entry Point: 0x00000000
5287 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5288 option performs the converse operation of the mkimage's second form (the "-d"
5289 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5292 tools/dumpimage -i image -p position data_file
5293 -i ==> extract from the 'image' a specific 'data_file', \
5294 indexed by 'position'
5297 Installing a Linux Image:
5298 -------------------------
5300 To downloading a U-Boot image over the serial (console) interface,
5301 you must convert the image to S-Record format:
5303 objcopy -I binary -O srec examples/image examples/image.srec
5305 The 'objcopy' does not understand the information in the U-Boot
5306 image header, so the resulting S-Record file will be relative to
5307 address 0x00000000. To load it to a given address, you need to
5308 specify the target address as 'offset' parameter with the 'loads'
5311 Example: install the image to address 0x40100000 (which on the
5312 TQM8xxL is in the first Flash bank):
5314 => erase 40100000 401FFFFF
5320 ## Ready for S-Record download ...
5321 ~>examples/image.srec
5322 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5324 15989 15990 15991 15992
5325 [file transfer complete]
5327 ## Start Addr = 0x00000000
5330 You can check the success of the download using the 'iminfo' command;
5331 this includes a checksum verification so you can be sure no data
5332 corruption happened:
5336 ## Checking Image at 40100000 ...
5337 Image Name: 2.2.13 for initrd on TQM850L
5338 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5339 Data Size: 335725 Bytes = 327 kB = 0 MB
5340 Load Address: 00000000
5341 Entry Point: 0000000c
5342 Verifying Checksum ... OK
5348 The "bootm" command is used to boot an application that is stored in
5349 memory (RAM or Flash). In case of a Linux kernel image, the contents
5350 of the "bootargs" environment variable is passed to the kernel as
5351 parameters. You can check and modify this variable using the
5352 "printenv" and "setenv" commands:
5355 => printenv bootargs
5356 bootargs=root=/dev/ram
5358 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5360 => printenv bootargs
5361 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5364 ## Booting Linux kernel at 40020000 ...
5365 Image Name: 2.2.13 for NFS on TQM850L
5366 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5367 Data Size: 381681 Bytes = 372 kB = 0 MB
5368 Load Address: 00000000
5369 Entry Point: 0000000c
5370 Verifying Checksum ... OK
5371 Uncompressing Kernel Image ... OK
5372 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
5373 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5374 time_init: decrementer frequency = 187500000/60
5375 Calibrating delay loop... 49.77 BogoMIPS
5376 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5379 If you want to boot a Linux kernel with initial RAM disk, you pass
5380 the memory addresses of both the kernel and the initrd image (PPBCOOT
5381 format!) to the "bootm" command:
5383 => imi 40100000 40200000
5385 ## Checking Image at 40100000 ...
5386 Image Name: 2.2.13 for initrd on TQM850L
5387 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5388 Data Size: 335725 Bytes = 327 kB = 0 MB
5389 Load Address: 00000000
5390 Entry Point: 0000000c
5391 Verifying Checksum ... OK
5393 ## Checking Image at 40200000 ...
5394 Image Name: Simple Ramdisk Image
5395 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5396 Data Size: 566530 Bytes = 553 kB = 0 MB
5397 Load Address: 00000000
5398 Entry Point: 00000000
5399 Verifying Checksum ... OK
5401 => bootm 40100000 40200000
5402 ## Booting Linux kernel at 40100000 ...
5403 Image Name: 2.2.13 for initrd on TQM850L
5404 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5405 Data Size: 335725 Bytes = 327 kB = 0 MB
5406 Load Address: 00000000
5407 Entry Point: 0000000c
5408 Verifying Checksum ... OK
5409 Uncompressing Kernel Image ... OK
5410 ## Loading RAMDisk Image at 40200000 ...
5411 Image Name: Simple Ramdisk Image
5412 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5413 Data Size: 566530 Bytes = 553 kB = 0 MB
5414 Load Address: 00000000
5415 Entry Point: 00000000
5416 Verifying Checksum ... OK
5417 Loading Ramdisk ... OK
5418 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
5419 Boot arguments: root=/dev/ram
5420 time_init: decrementer frequency = 187500000/60
5421 Calibrating delay loop... 49.77 BogoMIPS
5423 RAMDISK: Compressed image found at block 0
5424 VFS: Mounted root (ext2 filesystem).
5428 Boot Linux and pass a flat device tree:
5431 First, U-Boot must be compiled with the appropriate defines. See the section
5432 titled "Linux Kernel Interface" above for a more in depth explanation. The
5433 following is an example of how to start a kernel and pass an updated
5439 oft=oftrees/mpc8540ads.dtb
5440 => tftp $oftaddr $oft
5441 Speed: 1000, full duplex
5443 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5444 Filename 'oftrees/mpc8540ads.dtb'.
5445 Load address: 0x300000
5448 Bytes transferred = 4106 (100a hex)
5449 => tftp $loadaddr $bootfile
5450 Speed: 1000, full duplex
5452 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5454 Load address: 0x200000
5455 Loading:############
5457 Bytes transferred = 1029407 (fb51f hex)
5462 => bootm $loadaddr - $oftaddr
5463 ## Booting image at 00200000 ...
5464 Image Name: Linux-2.6.17-dirty
5465 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5466 Data Size: 1029343 Bytes = 1005.2 kB
5467 Load Address: 00000000
5468 Entry Point: 00000000
5469 Verifying Checksum ... OK
5470 Uncompressing Kernel Image ... OK
5471 Booting using flat device tree at 0x300000
5472 Using MPC85xx ADS machine description
5473 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5477 More About U-Boot Image Types:
5478 ------------------------------
5480 U-Boot supports the following image types:
5482 "Standalone Programs" are directly runnable in the environment
5483 provided by U-Boot; it is expected that (if they behave
5484 well) you can continue to work in U-Boot after return from
5485 the Standalone Program.
5486 "OS Kernel Images" are usually images of some Embedded OS which
5487 will take over control completely. Usually these programs
5488 will install their own set of exception handlers, device
5489 drivers, set up the MMU, etc. - this means, that you cannot
5490 expect to re-enter U-Boot except by resetting the CPU.
5491 "RAMDisk Images" are more or less just data blocks, and their
5492 parameters (address, size) are passed to an OS kernel that is
5494 "Multi-File Images" contain several images, typically an OS
5495 (Linux) kernel image and one or more data images like
5496 RAMDisks. This construct is useful for instance when you want
5497 to boot over the network using BOOTP etc., where the boot
5498 server provides just a single image file, but you want to get
5499 for instance an OS kernel and a RAMDisk image.
5501 "Multi-File Images" start with a list of image sizes, each
5502 image size (in bytes) specified by an "uint32_t" in network
5503 byte order. This list is terminated by an "(uint32_t)0".
5504 Immediately after the terminating 0 follow the images, one by
5505 one, all aligned on "uint32_t" boundaries (size rounded up to
5506 a multiple of 4 bytes).
5508 "Firmware Images" are binary images containing firmware (like
5509 U-Boot or FPGA images) which usually will be programmed to
5512 "Script files" are command sequences that will be executed by
5513 U-Boot's command interpreter; this feature is especially
5514 useful when you configure U-Boot to use a real shell (hush)
5515 as command interpreter.
5517 Booting the Linux zImage:
5518 -------------------------
5520 On some platforms, it's possible to boot Linux zImage. This is done
5521 using the "bootz" command. The syntax of "bootz" command is the same
5522 as the syntax of "bootm" command.
5524 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5525 kernel with raw initrd images. The syntax is slightly different, the
5526 address of the initrd must be augmented by it's size, in the following
5527 format: "<initrd addres>:<initrd size>".
5533 One of the features of U-Boot is that you can dynamically load and
5534 run "standalone" applications, which can use some resources of
5535 U-Boot like console I/O functions or interrupt services.
5537 Two simple examples are included with the sources:
5542 'examples/hello_world.c' contains a small "Hello World" Demo
5543 application; it is automatically compiled when you build U-Boot.
5544 It's configured to run at address 0x00040004, so you can play with it
5548 ## Ready for S-Record download ...
5549 ~>examples/hello_world.srec
5550 1 2 3 4 5 6 7 8 9 10 11 ...
5551 [file transfer complete]
5553 ## Start Addr = 0x00040004
5555 => go 40004 Hello World! This is a test.
5556 ## Starting application at 0x00040004 ...
5567 Hit any key to exit ...
5569 ## Application terminated, rc = 0x0
5571 Another example, which demonstrates how to register a CPM interrupt
5572 handler with the U-Boot code, can be found in 'examples/timer.c'.
5573 Here, a CPM timer is set up to generate an interrupt every second.
5574 The interrupt service routine is trivial, just printing a '.'
5575 character, but this is just a demo program. The application can be
5576 controlled by the following keys:
5578 ? - print current values og the CPM Timer registers
5579 b - enable interrupts and start timer
5580 e - stop timer and disable interrupts
5581 q - quit application
5584 ## Ready for S-Record download ...
5585 ~>examples/timer.srec
5586 1 2 3 4 5 6 7 8 9 10 11 ...
5587 [file transfer complete]
5589 ## Start Addr = 0x00040004
5592 ## Starting application at 0x00040004 ...
5595 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5598 [q, b, e, ?] Set interval 1000000 us
5601 [q, b, e, ?] ........
5602 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5605 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5608 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5611 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5613 [q, b, e, ?] ...Stopping timer
5615 [q, b, e, ?] ## Application terminated, rc = 0x0
5621 Over time, many people have reported problems when trying to use the
5622 "minicom" terminal emulation program for serial download. I (wd)
5623 consider minicom to be broken, and recommend not to use it. Under
5624 Unix, I recommend to use C-Kermit for general purpose use (and
5625 especially for kermit binary protocol download ("loadb" command), and
5626 use "cu" for S-Record download ("loads" command). See
5627 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5628 for help with kermit.
5631 Nevertheless, if you absolutely want to use it try adding this
5632 configuration to your "File transfer protocols" section:
5634 Name Program Name U/D FullScr IO-Red. Multi
5635 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5636 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5642 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5643 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5645 Building requires a cross environment; it is known to work on
5646 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5647 need gmake since the Makefiles are not compatible with BSD make).
5648 Note that the cross-powerpc package does not install include files;
5649 attempting to build U-Boot will fail because <machine/ansi.h> is
5650 missing. This file has to be installed and patched manually:
5652 # cd /usr/pkg/cross/powerpc-netbsd/include
5654 # ln -s powerpc machine
5655 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5656 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5658 Native builds *don't* work due to incompatibilities between native
5659 and U-Boot include files.
5661 Booting assumes that (the first part of) the image booted is a
5662 stage-2 loader which in turn loads and then invokes the kernel
5663 proper. Loader sources will eventually appear in the NetBSD source
5664 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5665 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5668 Implementation Internals:
5669 =========================
5671 The following is not intended to be a complete description of every
5672 implementation detail. However, it should help to understand the
5673 inner workings of U-Boot and make it easier to port it to custom
5677 Initial Stack, Global Data:
5678 ---------------------------
5680 The implementation of U-Boot is complicated by the fact that U-Boot
5681 starts running out of ROM (flash memory), usually without access to
5682 system RAM (because the memory controller is not initialized yet).
5683 This means that we don't have writable Data or BSS segments, and BSS
5684 is not initialized as zero. To be able to get a C environment working
5685 at all, we have to allocate at least a minimal stack. Implementation
5686 options for this are defined and restricted by the CPU used: Some CPU
5687 models provide on-chip memory (like the IMMR area on MPC8xx and
5688 MPC826x processors), on others (parts of) the data cache can be
5689 locked as (mis-) used as memory, etc.
5691 Chris Hallinan posted a good summary of these issues to the
5692 U-Boot mailing list:
5694 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5695 From: "Chris Hallinan" <clh@net1plus.com>
5696 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5699 Correct me if I'm wrong, folks, but the way I understand it
5700 is this: Using DCACHE as initial RAM for Stack, etc, does not
5701 require any physical RAM backing up the cache. The cleverness
5702 is that the cache is being used as a temporary supply of
5703 necessary storage before the SDRAM controller is setup. It's
5704 beyond the scope of this list to explain the details, but you
5705 can see how this works by studying the cache architecture and
5706 operation in the architecture and processor-specific manuals.
5708 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5709 is another option for the system designer to use as an
5710 initial stack/RAM area prior to SDRAM being available. Either
5711 option should work for you. Using CS 4 should be fine if your
5712 board designers haven't used it for something that would
5713 cause you grief during the initial boot! It is frequently not
5716 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5717 with your processor/board/system design. The default value
5718 you will find in any recent u-boot distribution in
5719 walnut.h should work for you. I'd set it to a value larger
5720 than your SDRAM module. If you have a 64MB SDRAM module, set
5721 it above 400_0000. Just make sure your board has no resources
5722 that are supposed to respond to that address! That code in
5723 start.S has been around a while and should work as is when
5724 you get the config right.
5729 It is essential to remember this, since it has some impact on the C
5730 code for the initialization procedures:
5732 * Initialized global data (data segment) is read-only. Do not attempt
5735 * Do not use any uninitialized global data (or implicitely initialized
5736 as zero data - BSS segment) at all - this is undefined, initiali-
5737 zation is performed later (when relocating to RAM).
5739 * Stack space is very limited. Avoid big data buffers or things like
5742 Having only the stack as writable memory limits means we cannot use
5743 normal global data to share information beween the code. But it
5744 turned out that the implementation of U-Boot can be greatly
5745 simplified by making a global data structure (gd_t) available to all
5746 functions. We could pass a pointer to this data as argument to _all_
5747 functions, but this would bloat the code. Instead we use a feature of
5748 the GCC compiler (Global Register Variables) to share the data: we
5749 place a pointer (gd) to the global data into a register which we
5750 reserve for this purpose.
5752 When choosing a register for such a purpose we are restricted by the
5753 relevant (E)ABI specifications for the current architecture, and by
5754 GCC's implementation.
5756 For PowerPC, the following registers have specific use:
5758 R2: reserved for system use
5759 R3-R4: parameter passing and return values
5760 R5-R10: parameter passing
5761 R13: small data area pointer
5765 (U-Boot also uses R12 as internal GOT pointer. r12
5766 is a volatile register so r12 needs to be reset when
5767 going back and forth between asm and C)
5769 ==> U-Boot will use R2 to hold a pointer to the global data
5771 Note: on PPC, we could use a static initializer (since the
5772 address of the global data structure is known at compile time),
5773 but it turned out that reserving a register results in somewhat
5774 smaller code - although the code savings are not that big (on
5775 average for all boards 752 bytes for the whole U-Boot image,
5776 624 text + 127 data).
5778 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5779 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5781 ==> U-Boot will use P3 to hold a pointer to the global data
5783 On ARM, the following registers are used:
5785 R0: function argument word/integer result
5786 R1-R3: function argument word
5787 R9: platform specific
5788 R10: stack limit (used only if stack checking is enabled)
5789 R11: argument (frame) pointer
5790 R12: temporary workspace
5793 R15: program counter
5795 ==> U-Boot will use R9 to hold a pointer to the global data
5797 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5799 On Nios II, the ABI is documented here:
5800 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5802 ==> U-Boot will use gp to hold a pointer to the global data
5804 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5805 to access small data sections, so gp is free.
5807 On NDS32, the following registers are used:
5809 R0-R1: argument/return
5811 R15: temporary register for assembler
5812 R16: trampoline register
5813 R28: frame pointer (FP)
5814 R29: global pointer (GP)
5815 R30: link register (LP)
5816 R31: stack pointer (SP)
5817 PC: program counter (PC)
5819 ==> U-Boot will use R10 to hold a pointer to the global data
5821 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5822 or current versions of GCC may "optimize" the code too much.
5827 U-Boot runs in system state and uses physical addresses, i.e. the
5828 MMU is not used either for address mapping nor for memory protection.
5830 The available memory is mapped to fixed addresses using the memory
5831 controller. In this process, a contiguous block is formed for each
5832 memory type (Flash, SDRAM, SRAM), even when it consists of several
5833 physical memory banks.
5835 U-Boot is installed in the first 128 kB of the first Flash bank (on
5836 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5837 booting and sizing and initializing DRAM, the code relocates itself
5838 to the upper end of DRAM. Immediately below the U-Boot code some
5839 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5840 configuration setting]. Below that, a structure with global Board
5841 Info data is placed, followed by the stack (growing downward).
5843 Additionally, some exception handler code is copied to the low 8 kB
5844 of DRAM (0x00000000 ... 0x00001FFF).
5846 So a typical memory configuration with 16 MB of DRAM could look like
5849 0x0000 0000 Exception Vector code
5852 0x0000 2000 Free for Application Use
5858 0x00FB FF20 Monitor Stack (Growing downward)
5859 0x00FB FFAC Board Info Data and permanent copy of global data
5860 0x00FC 0000 Malloc Arena
5863 0x00FE 0000 RAM Copy of Monitor Code
5864 ... eventually: LCD or video framebuffer
5865 ... eventually: pRAM (Protected RAM - unchanged by reset)
5866 0x00FF FFFF [End of RAM]
5869 System Initialization:
5870 ----------------------
5872 In the reset configuration, U-Boot starts at the reset entry point
5873 (on most PowerPC systems at address 0x00000100). Because of the reset
5874 configuration for CS0# this is a mirror of the onboard Flash memory.
5875 To be able to re-map memory U-Boot then jumps to its link address.
5876 To be able to implement the initialization code in C, a (small!)
5877 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5878 which provide such a feature like MPC8xx or MPC8260), or in a locked
5879 part of the data cache. After that, U-Boot initializes the CPU core,
5880 the caches and the SIU.
5882 Next, all (potentially) available memory banks are mapped using a
5883 preliminary mapping. For example, we put them on 512 MB boundaries
5884 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5885 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5886 programmed for SDRAM access. Using the temporary configuration, a
5887 simple memory test is run that determines the size of the SDRAM
5890 When there is more than one SDRAM bank, and the banks are of
5891 different size, the largest is mapped first. For equal size, the first
5892 bank (CS2#) is mapped first. The first mapping is always for address
5893 0x00000000, with any additional banks following immediately to create
5894 contiguous memory starting from 0.
5896 Then, the monitor installs itself at the upper end of the SDRAM area
5897 and allocates memory for use by malloc() and for the global Board
5898 Info data; also, the exception vector code is copied to the low RAM
5899 pages, and the final stack is set up.
5901 Only after this relocation will you have a "normal" C environment;
5902 until that you are restricted in several ways, mostly because you are
5903 running from ROM, and because the code will have to be relocated to a
5907 U-Boot Porting Guide:
5908 ----------------------
5910 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5914 int main(int argc, char *argv[])
5916 sighandler_t no_more_time;
5918 signal(SIGALRM, no_more_time);
5919 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5921 if (available_money > available_manpower) {
5922 Pay consultant to port U-Boot;
5926 Download latest U-Boot source;
5928 Subscribe to u-boot mailing list;
5931 email("Hi, I am new to U-Boot, how do I get started?");
5934 Read the README file in the top level directory;
5935 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5936 Read applicable doc/*.README;
5937 Read the source, Luke;
5938 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5941 if (available_money > toLocalCurrency ($2500))
5944 Add a lot of aggravation and time;
5946 if (a similar board exists) { /* hopefully... */
5947 cp -a board/<similar> board/<myboard>
5948 cp include/configs/<similar>.h include/configs/<myboard>.h
5950 Create your own board support subdirectory;
5951 Create your own board include/configs/<myboard>.h file;
5953 Edit new board/<myboard> files
5954 Edit new include/configs/<myboard>.h
5959 Add / modify source code;
5963 email("Hi, I am having problems...");
5965 Send patch file to the U-Boot email list;
5966 if (reasonable critiques)
5967 Incorporate improvements from email list code review;
5969 Defend code as written;
5975 void no_more_time (int sig)
5984 All contributions to U-Boot should conform to the Linux kernel
5985 coding style; see the file "Documentation/CodingStyle" and the script
5986 "scripts/Lindent" in your Linux kernel source directory.
5988 Source files originating from a different project (for example the
5989 MTD subsystem) are generally exempt from these guidelines and are not
5990 reformated to ease subsequent migration to newer versions of those
5993 Please note that U-Boot is implemented in C (and to some small parts in
5994 Assembler); no C++ is used, so please do not use C++ style comments (//)
5997 Please also stick to the following formatting rules:
5998 - remove any trailing white space
5999 - use TAB characters for indentation and vertical alignment, not spaces
6000 - make sure NOT to use DOS '\r\n' line feeds
6001 - do not add more than 2 consecutive empty lines to source files
6002 - do not add trailing empty lines to source files
6004 Submissions which do not conform to the standards may be returned
6005 with a request to reformat the changes.
6011 Since the number of patches for U-Boot is growing, we need to
6012 establish some rules. Submissions which do not conform to these rules
6013 may be rejected, even when they contain important and valuable stuff.
6015 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6017 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6018 see http://lists.denx.de/mailman/listinfo/u-boot
6020 When you send a patch, please include the following information with
6023 * For bug fixes: a description of the bug and how your patch fixes
6024 this bug. Please try to include a way of demonstrating that the
6025 patch actually fixes something.
6027 * For new features: a description of the feature and your
6030 * A CHANGELOG entry as plaintext (separate from the patch)
6032 * For major contributions, your entry to the CREDITS file
6034 * When you add support for a new board, don't forget to add a
6035 maintainer e-mail address to the boards.cfg file, too.
6037 * If your patch adds new configuration options, don't forget to
6038 document these in the README file.
6040 * The patch itself. If you are using git (which is *strongly*
6041 recommended) you can easily generate the patch using the
6042 "git format-patch". If you then use "git send-email" to send it to
6043 the U-Boot mailing list, you will avoid most of the common problems
6044 with some other mail clients.
6046 If you cannot use git, use "diff -purN OLD NEW". If your version of
6047 diff does not support these options, then get the latest version of
6050 The current directory when running this command shall be the parent
6051 directory of the U-Boot source tree (i. e. please make sure that
6052 your patch includes sufficient directory information for the
6055 We prefer patches as plain text. MIME attachments are discouraged,
6056 and compressed attachments must not be used.
6058 * If one logical set of modifications affects or creates several
6059 files, all these changes shall be submitted in a SINGLE patch file.
6061 * Changesets that contain different, unrelated modifications shall be
6062 submitted as SEPARATE patches, one patch per changeset.
6067 * Before sending the patch, run the MAKEALL script on your patched
6068 source tree and make sure that no errors or warnings are reported
6069 for any of the boards.
6071 * Keep your modifications to the necessary minimum: A patch
6072 containing several unrelated changes or arbitrary reformats will be
6073 returned with a request to re-formatting / split it.
6075 * If you modify existing code, make sure that your new code does not
6076 add to the memory footprint of the code ;-) Small is beautiful!
6077 When adding new features, these should compile conditionally only
6078 (using #ifdef), and the resulting code with the new feature
6079 disabled must not need more memory than the old code without your
6082 * Remember that there is a size limit of 100 kB per message on the
6083 u-boot mailing list. Bigger patches will be moderated. If they are
6084 reasonable and not too big, they will be acknowledged. But patches
6085 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob