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_SAVEENV saveenv
927 CONFIG_CMD_FDC * Floppy Disk Support
928 CONFIG_CMD_FAT * FAT command support
929 CONFIG_CMD_FDOS * Dos diskette Support
930 CONFIG_CMD_FLASH flinfo, erase, protect
931 CONFIG_CMD_FPGA FPGA device initialization support
932 CONFIG_CMD_FUSE * Device fuse support
933 CONFIG_CMD_GETTIME * Get time since boot
934 CONFIG_CMD_GO * the 'go' command (exec code)
935 CONFIG_CMD_GREPENV * search environment
936 CONFIG_CMD_HASH * calculate hash / digest
937 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
938 CONFIG_CMD_I2C * I2C serial bus support
939 CONFIG_CMD_IDE * IDE harddisk support
940 CONFIG_CMD_IMI iminfo
941 CONFIG_CMD_IMLS List all images found in NOR flash
942 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
943 CONFIG_CMD_IMMAP * IMMR dump support
944 CONFIG_CMD_IMPORTENV * import an environment
945 CONFIG_CMD_INI * import data from an ini file into the env
946 CONFIG_CMD_IRQ * irqinfo
947 CONFIG_CMD_ITEST Integer/string test of 2 values
948 CONFIG_CMD_JFFS2 * JFFS2 Support
949 CONFIG_CMD_KGDB * kgdb
950 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
951 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
953 CONFIG_CMD_LOADB loadb
954 CONFIG_CMD_LOADS loads
955 CONFIG_CMD_MD5SUM * print md5 message digest
956 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
957 CONFIG_CMD_MEMINFO * Display detailed memory information
958 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
960 CONFIG_CMD_MEMTEST * mtest
961 CONFIG_CMD_MISC Misc functions like sleep etc
962 CONFIG_CMD_MMC * MMC memory mapped support
963 CONFIG_CMD_MII * MII utility commands
964 CONFIG_CMD_MTDPARTS * MTD partition support
965 CONFIG_CMD_NAND * NAND support
966 CONFIG_CMD_NET bootp, tftpboot, rarpboot
967 CONFIG_CMD_NFS NFS support
968 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
969 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
970 CONFIG_CMD_PCI * pciinfo
971 CONFIG_CMD_PCMCIA * PCMCIA support
972 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
974 CONFIG_CMD_PORTIO * Port I/O
975 CONFIG_CMD_READ * Read raw data from partition
976 CONFIG_CMD_REGINFO * Register dump
977 CONFIG_CMD_RUN run command in env variable
978 CONFIG_CMD_SANDBOX * sb command to access sandbox features
979 CONFIG_CMD_SAVES * save S record dump
980 CONFIG_CMD_SCSI * SCSI Support
981 CONFIG_CMD_SDRAM * print SDRAM configuration information
982 (requires CONFIG_CMD_I2C)
983 CONFIG_CMD_SETGETDCR Support for DCR Register access
985 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
986 CONFIG_CMD_SHA1SUM * print sha1 memory digest
987 (requires CONFIG_CMD_MEMORY)
988 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
989 CONFIG_CMD_SOURCE "source" command Support
990 CONFIG_CMD_SPI * SPI serial bus support
991 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
992 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
993 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
994 CONFIG_CMD_TIMER * access to the system tick timer
995 CONFIG_CMD_USB * USB support
996 CONFIG_CMD_CDP * Cisco Discover Protocol support
997 CONFIG_CMD_MFSL * Microblaze FSL support
998 CONFIG_CMD_XIMG Load part of Multi Image
1001 EXAMPLE: If you want all functions except of network
1002 support you can write:
1004 #include "config_cmd_all.h"
1005 #undef CONFIG_CMD_NET
1008 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1010 Note: Don't enable the "icache" and "dcache" commands
1011 (configuration option CONFIG_CMD_CACHE) unless you know
1012 what you (and your U-Boot users) are doing. Data
1013 cache cannot be enabled on systems like the 8xx or
1014 8260 (where accesses to the IMMR region must be
1015 uncached), and it cannot be disabled on all other
1016 systems where we (mis-) use the data cache to hold an
1017 initial stack and some data.
1020 XXX - this list needs to get updated!
1022 - Regular expression support:
1024 If this variable is defined, U-Boot is linked against
1025 the SLRE (Super Light Regular Expression) library,
1026 which adds regex support to some commands, as for
1027 example "env grep" and "setexpr".
1031 If this variable is defined, U-Boot will use a device tree
1032 to configure its devices, instead of relying on statically
1033 compiled #defines in the board file. This option is
1034 experimental and only available on a few boards. The device
1035 tree is available in the global data as gd->fdt_blob.
1037 U-Boot needs to get its device tree from somewhere. This can
1038 be done using one of the two options below:
1041 If this variable is defined, U-Boot will embed a device tree
1042 binary in its image. This device tree file should be in the
1043 board directory and called <soc>-<board>.dts. The binary file
1044 is then picked up in board_init_f() and made available through
1045 the global data structure as gd->blob.
1048 If this variable is defined, U-Boot will build a device tree
1049 binary. It will be called u-boot.dtb. Architecture-specific
1050 code will locate it at run-time. Generally this works by:
1052 cat u-boot.bin u-boot.dtb >image.bin
1054 and in fact, U-Boot does this for you, creating a file called
1055 u-boot-dtb.bin which is useful in the common case. You can
1056 still use the individual files if you need something more
1061 If this variable is defined, it enables watchdog
1062 support for the SoC. There must be support in the SoC
1063 specific code for a watchdog. For the 8xx and 8260
1064 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1065 register. When supported for a specific SoC is
1066 available, then no further board specific code should
1067 be needed to use it.
1070 When using a watchdog circuitry external to the used
1071 SoC, then define this variable and provide board
1072 specific code for the "hw_watchdog_reset" function.
1075 CONFIG_VERSION_VARIABLE
1076 If this variable is defined, an environment variable
1077 named "ver" is created by U-Boot showing the U-Boot
1078 version as printed by the "version" command.
1079 Any change to this variable will be reverted at the
1084 When CONFIG_CMD_DATE is selected, the type of the RTC
1085 has to be selected, too. Define exactly one of the
1088 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1089 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1090 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1091 CONFIG_RTC_MC146818 - use MC146818 RTC
1092 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1093 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1094 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1095 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1096 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1097 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1098 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1099 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1102 Note that if the RTC uses I2C, then the I2C interface
1103 must also be configured. See I2C Support, below.
1106 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1108 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1109 chip-ngpio pairs that tell the PCA953X driver the number of
1110 pins supported by a particular chip.
1112 Note that if the GPIO device uses I2C, then the I2C interface
1113 must also be configured. See I2C Support, below.
1115 - Timestamp Support:
1117 When CONFIG_TIMESTAMP is selected, the timestamp
1118 (date and time) of an image is printed by image
1119 commands like bootm or iminfo. This option is
1120 automatically enabled when you select CONFIG_CMD_DATE .
1122 - Partition Labels (disklabels) Supported:
1123 Zero or more of the following:
1124 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1125 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1126 Intel architecture, USB sticks, etc.
1127 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1128 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1129 bootloader. Note 2TB partition limit; see
1131 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1133 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1134 CONFIG_CMD_SCSI) you must configure support for at
1135 least one non-MTD partition type as well.
1138 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1139 board configurations files but used nowhere!
1141 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1142 be performed by calling the function
1143 ide_set_reset(int reset)
1144 which has to be defined in a board specific file
1149 Set this to enable ATAPI support.
1154 Set this to enable support for disks larger than 137GB
1155 Also look at CONFIG_SYS_64BIT_LBA.
1156 Whithout these , LBA48 support uses 32bit variables and will 'only'
1157 support disks up to 2.1TB.
1159 CONFIG_SYS_64BIT_LBA:
1160 When enabled, makes the IDE subsystem use 64bit sector addresses.
1164 At the moment only there is only support for the
1165 SYM53C8XX SCSI controller; define
1166 CONFIG_SCSI_SYM53C8XX to enable it.
1168 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1169 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1170 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1171 maximum numbers of LUNs, SCSI ID's and target
1173 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1175 The environment variable 'scsidevs' is set to the number of
1176 SCSI devices found during the last scan.
1178 - NETWORK Support (PCI):
1180 Support for Intel 8254x/8257x gigabit chips.
1183 Utility code for direct access to the SPI bus on Intel 8257x.
1184 This does not do anything useful unless you set at least one
1185 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1187 CONFIG_E1000_SPI_GENERIC
1188 Allow generic access to the SPI bus on the Intel 8257x, for
1189 example with the "sspi" command.
1192 Management command for E1000 devices. When used on devices
1193 with SPI support you can reprogram the EEPROM from U-Boot.
1195 CONFIG_E1000_FALLBACK_MAC
1196 default MAC for empty EEPROM after production.
1199 Support for Intel 82557/82559/82559ER chips.
1200 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1201 write routine for first time initialisation.
1204 Support for Digital 2114x chips.
1205 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1206 modem chip initialisation (KS8761/QS6611).
1209 Support for National dp83815 chips.
1212 Support for National dp8382[01] gigabit chips.
1214 - NETWORK Support (other):
1216 CONFIG_DRIVER_AT91EMAC
1217 Support for AT91RM9200 EMAC.
1220 Define this to use reduced MII inteface
1222 CONFIG_DRIVER_AT91EMAC_QUIET
1223 If this defined, the driver is quiet.
1224 The driver doen't show link status messages.
1226 CONFIG_CALXEDA_XGMAC
1227 Support for the Calxeda XGMAC device
1230 Support for SMSC's LAN91C96 chips.
1232 CONFIG_LAN91C96_BASE
1233 Define this to hold the physical address
1234 of the LAN91C96's I/O space
1236 CONFIG_LAN91C96_USE_32_BIT
1237 Define this to enable 32 bit addressing
1240 Support for SMSC's LAN91C111 chip
1242 CONFIG_SMC91111_BASE
1243 Define this to hold the physical address
1244 of the device (I/O space)
1246 CONFIG_SMC_USE_32_BIT
1247 Define this if data bus is 32 bits
1249 CONFIG_SMC_USE_IOFUNCS
1250 Define this to use i/o functions instead of macros
1251 (some hardware wont work with macros)
1253 CONFIG_DRIVER_TI_EMAC
1254 Support for davinci emac
1256 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1257 Define this if you have more then 3 PHYs.
1260 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1262 CONFIG_FTGMAC100_EGIGA
1263 Define this to use GE link update with gigabit PHY.
1264 Define this if FTGMAC100 is connected to gigabit PHY.
1265 If your system has 10/100 PHY only, it might not occur
1266 wrong behavior. Because PHY usually return timeout or
1267 useless data when polling gigabit status and gigabit
1268 control registers. This behavior won't affect the
1269 correctnessof 10/100 link speed update.
1272 Support for SMSC's LAN911x and LAN921x chips
1275 Define this to hold the physical address
1276 of the device (I/O space)
1278 CONFIG_SMC911X_32_BIT
1279 Define this if data bus is 32 bits
1281 CONFIG_SMC911X_16_BIT
1282 Define this if data bus is 16 bits. If your processor
1283 automatically converts one 32 bit word to two 16 bit
1284 words you may also try CONFIG_SMC911X_32_BIT.
1287 Support for Renesas on-chip Ethernet controller
1289 CONFIG_SH_ETHER_USE_PORT
1290 Define the number of ports to be used
1292 CONFIG_SH_ETHER_PHY_ADDR
1293 Define the ETH PHY's address
1295 CONFIG_SH_ETHER_CACHE_WRITEBACK
1296 If this option is set, the driver enables cache flush.
1300 Support TPM devices.
1303 Support for i2c bus TPM devices. Only one device
1304 per system is supported at this time.
1306 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1307 Define the the i2c bus number for the TPM device
1309 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1310 Define the TPM's address on the i2c bus
1312 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1313 Define the burst count bytes upper limit
1315 CONFIG_TPM_ATMEL_TWI
1316 Support for Atmel TWI TPM device. Requires I2C support.
1319 Support for generic parallel port TPM devices. Only one device
1320 per system is supported at this time.
1322 CONFIG_TPM_TIS_BASE_ADDRESS
1323 Base address where the generic TPM device is mapped
1324 to. Contemporary x86 systems usually map it at
1328 Add tpm monitor functions.
1329 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1330 provides monitor access to authorized functions.
1333 Define this to enable the TPM support library which provides
1334 functional interfaces to some TPM commands.
1335 Requires support for a TPM device.
1337 CONFIG_TPM_AUTH_SESSIONS
1338 Define this to enable authorized functions in the TPM library.
1339 Requires CONFIG_TPM and CONFIG_SHA1.
1342 At the moment only the UHCI host controller is
1343 supported (PIP405, MIP405, MPC5200); define
1344 CONFIG_USB_UHCI to enable it.
1345 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1346 and define CONFIG_USB_STORAGE to enable the USB
1349 Supported are USB Keyboards and USB Floppy drives
1351 MPC5200 USB requires additional defines:
1353 for 528 MHz Clock: 0x0001bbbb
1357 for differential drivers: 0x00001000
1358 for single ended drivers: 0x00005000
1359 for differential drivers on PSC3: 0x00000100
1360 for single ended drivers on PSC3: 0x00004100
1361 CONFIG_SYS_USB_EVENT_POLL
1362 May be defined to allow interrupt polling
1363 instead of using asynchronous interrupts
1365 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1366 txfilltuning field in the EHCI controller on reset.
1368 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1369 interval for usb hub power-on delay.(minimum 100msec)
1372 Define the below if you wish to use the USB console.
1373 Once firmware is rebuilt from a serial console issue the
1374 command "setenv stdin usbtty; setenv stdout usbtty" and
1375 attach your USB cable. The Unix command "dmesg" should print
1376 it has found a new device. The environment variable usbtty
1377 can be set to gserial or cdc_acm to enable your device to
1378 appear to a USB host as a Linux gserial device or a
1379 Common Device Class Abstract Control Model serial device.
1380 If you select usbtty = gserial you should be able to enumerate
1382 # modprobe usbserial vendor=0xVendorID product=0xProductID
1383 else if using cdc_acm, simply setting the environment
1384 variable usbtty to be cdc_acm should suffice. The following
1385 might be defined in YourBoardName.h
1388 Define this to build a UDC device
1391 Define this to have a tty type of device available to
1392 talk to the UDC device
1395 Define this to enable the high speed support for usb
1396 device and usbtty. If this feature is enabled, a routine
1397 int is_usbd_high_speed(void)
1398 also needs to be defined by the driver to dynamically poll
1399 whether the enumeration has succeded at high speed or full
1402 CONFIG_SYS_CONSOLE_IS_IN_ENV
1403 Define this if you want stdin, stdout &/or stderr to
1407 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1408 Derive USB clock from external clock "blah"
1409 - CONFIG_SYS_USB_EXTC_CLK 0x02
1411 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1412 Derive USB clock from brgclk
1413 - CONFIG_SYS_USB_BRG_CLK 0x04
1415 If you have a USB-IF assigned VendorID then you may wish to
1416 define your own vendor specific values either in BoardName.h
1417 or directly in usbd_vendor_info.h. If you don't define
1418 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1419 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1420 should pretend to be a Linux device to it's target host.
1422 CONFIG_USBD_MANUFACTURER
1423 Define this string as the name of your company for
1424 - CONFIG_USBD_MANUFACTURER "my company"
1426 CONFIG_USBD_PRODUCT_NAME
1427 Define this string as the name of your product
1428 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1430 CONFIG_USBD_VENDORID
1431 Define this as your assigned Vendor ID from the USB
1432 Implementors Forum. This *must* be a genuine Vendor ID
1433 to avoid polluting the USB namespace.
1434 - CONFIG_USBD_VENDORID 0xFFFF
1436 CONFIG_USBD_PRODUCTID
1437 Define this as the unique Product ID
1439 - CONFIG_USBD_PRODUCTID 0xFFFF
1441 Some USB device drivers may need to check USB cable attachment.
1442 In this case you can enable following config in BoardName.h:
1443 CONFIG_USB_CABLE_CHECK
1444 This enables function definition:
1445 - usb_cable_connected() in include/usb.h
1446 Implementation of this function is board-specific.
1448 - ULPI Layer Support:
1449 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1450 the generic ULPI layer. The generic layer accesses the ULPI PHY
1451 via the platform viewport, so you need both the genric layer and
1452 the viewport enabled. Currently only Chipidea/ARC based
1453 viewport is supported.
1454 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1455 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1456 If your ULPI phy needs a different reference clock than the
1457 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1458 the appropriate value in Hz.
1461 The MMC controller on the Intel PXA is supported. To
1462 enable this define CONFIG_MMC. The MMC can be
1463 accessed from the boot prompt by mapping the device
1464 to physical memory similar to flash. Command line is
1465 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1466 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1469 Support for Renesas on-chip MMCIF controller
1471 CONFIG_SH_MMCIF_ADDR
1472 Define the base address of MMCIF registers
1475 Define the clock frequency for MMCIF
1477 - USB Device Firmware Update (DFU) class support:
1479 This enables the USB portion of the DFU USB class
1482 This enables the command "dfu" which is used to have
1483 U-Boot create a DFU class device via USB. This command
1484 requires that the "dfu_alt_info" environment variable be
1485 set and define the alt settings to expose to the host.
1488 This enables support for exposing (e)MMC devices via DFU.
1491 This enables support for exposing NAND devices via DFU.
1494 This enables support for exposing RAM via DFU.
1495 Note: DFU spec refer to non-volatile memory usage, but
1496 allow usages beyond the scope of spec - here RAM usage,
1497 one that would help mostly the developer.
1499 CONFIG_SYS_DFU_DATA_BUF_SIZE
1500 Dfu transfer uses a buffer before writing data to the
1501 raw storage device. Make the size (in bytes) of this buffer
1502 configurable. The size of this buffer is also configurable
1503 through the "dfu_bufsiz" environment variable.
1505 CONFIG_SYS_DFU_MAX_FILE_SIZE
1506 When updating files rather than the raw storage device,
1507 we use a static buffer to copy the file into and then write
1508 the buffer once we've been given the whole file. Define
1509 this to the maximum filesize (in bytes) for the buffer.
1510 Default is 4 MiB if undefined.
1512 - Journaling Flash filesystem support:
1513 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1514 CONFIG_JFFS2_NAND_DEV
1515 Define these for a default partition on a NAND device
1517 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1518 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1519 Define these for a default partition on a NOR device
1521 CONFIG_SYS_JFFS_CUSTOM_PART
1522 Define this to create an own partition. You have to provide a
1523 function struct part_info* jffs2_part_info(int part_num)
1525 If you define only one JFFS2 partition you may also want to
1526 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1527 to disable the command chpart. This is the default when you
1528 have not defined a custom partition
1530 - FAT(File Allocation Table) filesystem write function support:
1533 Define this to enable support for saving memory data as a
1534 file in FAT formatted partition.
1536 This will also enable the command "fatwrite" enabling the
1537 user to write files to FAT.
1539 CBFS (Coreboot Filesystem) support
1542 Define this to enable support for reading from a Coreboot
1543 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1549 Define this to enable standard (PC-Style) keyboard
1553 Standard PC keyboard driver with US (is default) and
1554 GERMAN key layout (switch via environment 'keymap=de') support.
1555 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1556 for cfb_console. Supports cursor blinking.
1559 Enables a Chrome OS keyboard using the CROS_EC interface.
1560 This uses CROS_EC to communicate with a second microcontroller
1561 which provides key scans on request.
1566 Define this to enable video support (for output to
1569 CONFIG_VIDEO_CT69000
1571 Enable Chips & Technologies 69000 Video chip
1573 CONFIG_VIDEO_SMI_LYNXEM
1574 Enable Silicon Motion SMI 712/710/810 Video chip. The
1575 video output is selected via environment 'videoout'
1576 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1579 For the CT69000 and SMI_LYNXEM drivers, videomode is
1580 selected via environment 'videomode'. Two different ways
1582 - "videomode=num" 'num' is a standard LiLo mode numbers.
1583 Following standard modes are supported (* is default):
1585 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1586 -------------+---------------------------------------------
1587 8 bits | 0x301* 0x303 0x305 0x161 0x307
1588 15 bits | 0x310 0x313 0x316 0x162 0x319
1589 16 bits | 0x311 0x314 0x317 0x163 0x31A
1590 24 bits | 0x312 0x315 0x318 ? 0x31B
1591 -------------+---------------------------------------------
1592 (i.e. setenv videomode 317; saveenv; reset;)
1594 - "videomode=bootargs" all the video parameters are parsed
1595 from the bootargs. (See drivers/video/videomodes.c)
1598 CONFIG_VIDEO_SED13806
1599 Enable Epson SED13806 driver. This driver supports 8bpp
1600 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1601 or CONFIG_VIDEO_SED13806_16BPP
1604 Enable the Freescale DIU video driver. Reference boards for
1605 SOCs that have a DIU should define this macro to enable DIU
1606 support, and should also define these other macros:
1612 CONFIG_VIDEO_SW_CURSOR
1613 CONFIG_VGA_AS_SINGLE_DEVICE
1615 CONFIG_VIDEO_BMP_LOGO
1617 The DIU driver will look for the 'video-mode' environment
1618 variable, and if defined, enable the DIU as a console during
1619 boot. See the documentation file README.video for a
1620 description of this variable.
1624 Enable the VGA video / BIOS for x86. The alternative if you
1625 are using coreboot is to use the coreboot frame buffer
1632 Define this to enable a custom keyboard support.
1633 This simply calls drv_keyboard_init() which must be
1634 defined in your board-specific files.
1635 The only board using this so far is RBC823.
1637 - LCD Support: CONFIG_LCD
1639 Define this to enable LCD support (for output to LCD
1640 display); also select one of the supported displays
1641 by defining one of these:
1645 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1647 CONFIG_NEC_NL6448AC33:
1649 NEC NL6448AC33-18. Active, color, single scan.
1651 CONFIG_NEC_NL6448BC20
1653 NEC NL6448BC20-08. 6.5", 640x480.
1654 Active, color, single scan.
1656 CONFIG_NEC_NL6448BC33_54
1658 NEC NL6448BC33-54. 10.4", 640x480.
1659 Active, color, single scan.
1663 Sharp 320x240. Active, color, single scan.
1664 It isn't 16x9, and I am not sure what it is.
1666 CONFIG_SHARP_LQ64D341
1668 Sharp LQ64D341 display, 640x480.
1669 Active, color, single scan.
1673 HLD1045 display, 640x480.
1674 Active, color, single scan.
1678 Optrex CBL50840-2 NF-FW 99 22 M5
1680 Hitachi LMG6912RPFC-00T
1684 320x240. Black & white.
1686 Normally display is black on white background; define
1687 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1689 CONFIG_LCD_ALIGNMENT
1691 Normally the LCD is page-aligned (tyically 4KB). If this is
1692 defined then the LCD will be aligned to this value instead.
1693 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1694 here, since it is cheaper to change data cache settings on
1695 a per-section basis.
1697 CONFIG_CONSOLE_SCROLL_LINES
1699 When the console need to be scrolled, this is the number of
1700 lines to scroll by. It defaults to 1. Increasing this makes
1701 the console jump but can help speed up operation when scrolling
1706 Support drawing of RLE8-compressed bitmaps on the LCD.
1710 Enables an 'i2c edid' command which can read EDID
1711 information over I2C from an attached LCD display.
1713 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1715 If this option is set, the environment is checked for
1716 a variable "splashimage". If found, the usual display
1717 of logo, copyright and system information on the LCD
1718 is suppressed and the BMP image at the address
1719 specified in "splashimage" is loaded instead. The
1720 console is redirected to the "nulldev", too. This
1721 allows for a "silent" boot where a splash screen is
1722 loaded very quickly after power-on.
1724 CONFIG_SPLASHIMAGE_GUARD
1726 If this option is set, then U-Boot will prevent the environment
1727 variable "splashimage" from being set to a problematic address
1728 (see README.displaying-bmps and README.arm-unaligned-accesses).
1729 This option is useful for targets where, due to alignment
1730 restrictions, an improperly aligned BMP image will cause a data
1731 abort. If you think you will not have problems with unaligned
1732 accesses (for example because your toolchain prevents them)
1733 there is no need to set this option.
1735 CONFIG_SPLASH_SCREEN_ALIGN
1737 If this option is set the splash image can be freely positioned
1738 on the screen. Environment variable "splashpos" specifies the
1739 position as "x,y". If a positive number is given it is used as
1740 number of pixel from left/top. If a negative number is given it
1741 is used as number of pixel from right/bottom. You can also
1742 specify 'm' for centering the image.
1745 setenv splashpos m,m
1746 => image at center of screen
1748 setenv splashpos 30,20
1749 => image at x = 30 and y = 20
1751 setenv splashpos -10,m
1752 => vertically centered image
1753 at x = dspWidth - bmpWidth - 9
1755 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1757 If this option is set, additionally to standard BMP
1758 images, gzipped BMP images can be displayed via the
1759 splashscreen support or the bmp command.
1761 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1763 If this option is set, 8-bit RLE compressed BMP images
1764 can be displayed via the splashscreen support or the
1767 - Do compresssing for memory range:
1770 If this option is set, it would use zlib deflate method
1771 to compress the specified memory at its best effort.
1773 - Compression support:
1776 Enabled by default to support gzip compressed images.
1780 If this option is set, support for bzip2 compressed
1781 images is included. If not, only uncompressed and gzip
1782 compressed images are supported.
1784 NOTE: the bzip2 algorithm requires a lot of RAM, so
1785 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1790 If this option is set, support for lzma compressed
1793 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1794 requires an amount of dynamic memory that is given by the
1797 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1799 Where lc and lp stand for, respectively, Literal context bits
1800 and Literal pos bits.
1802 This value is upper-bounded by 14MB in the worst case. Anyway,
1803 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1804 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1805 a very small buffer.
1807 Use the lzmainfo tool to determinate the lc and lp values and
1808 then calculate the amount of needed dynamic memory (ensuring
1809 the appropriate CONFIG_SYS_MALLOC_LEN value).
1813 If this option is set, support for LZO compressed images
1819 The address of PHY on MII bus.
1821 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1823 The clock frequency of the MII bus
1827 If this option is set, support for speed/duplex
1828 detection of gigabit PHY is included.
1830 CONFIG_PHY_RESET_DELAY
1832 Some PHY like Intel LXT971A need extra delay after
1833 reset before any MII register access is possible.
1834 For such PHY, set this option to the usec delay
1835 required. (minimum 300usec for LXT971A)
1837 CONFIG_PHY_CMD_DELAY (ppc4xx)
1839 Some PHY like Intel LXT971A need extra delay after
1840 command issued before MII status register can be read
1850 Define a default value for Ethernet address to use
1851 for the respective Ethernet interface, in case this
1852 is not determined automatically.
1857 Define a default value for the IP address to use for
1858 the default Ethernet interface, in case this is not
1859 determined through e.g. bootp.
1860 (Environment variable "ipaddr")
1862 - Server IP address:
1865 Defines a default value for the IP address of a TFTP
1866 server to contact when using the "tftboot" command.
1867 (Environment variable "serverip")
1869 CONFIG_KEEP_SERVERADDR
1871 Keeps the server's MAC address, in the env 'serveraddr'
1872 for passing to bootargs (like Linux's netconsole option)
1874 - Gateway IP address:
1877 Defines a default value for the IP address of the
1878 default router where packets to other networks are
1880 (Environment variable "gatewayip")
1885 Defines a default value for the subnet mask (or
1886 routing prefix) which is used to determine if an IP
1887 address belongs to the local subnet or needs to be
1888 forwarded through a router.
1889 (Environment variable "netmask")
1891 - Multicast TFTP Mode:
1894 Defines whether you want to support multicast TFTP as per
1895 rfc-2090; for example to work with atftp. Lets lots of targets
1896 tftp down the same boot image concurrently. Note: the Ethernet
1897 driver in use must provide a function: mcast() to join/leave a
1900 - BOOTP Recovery Mode:
1901 CONFIG_BOOTP_RANDOM_DELAY
1903 If you have many targets in a network that try to
1904 boot using BOOTP, you may want to avoid that all
1905 systems send out BOOTP requests at precisely the same
1906 moment (which would happen for instance at recovery
1907 from a power failure, when all systems will try to
1908 boot, thus flooding the BOOTP server. Defining
1909 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1910 inserted before sending out BOOTP requests. The
1911 following delays are inserted then:
1913 1st BOOTP request: delay 0 ... 1 sec
1914 2nd BOOTP request: delay 0 ... 2 sec
1915 3rd BOOTP request: delay 0 ... 4 sec
1917 BOOTP requests: delay 0 ... 8 sec
1919 - DHCP Advanced Options:
1920 You can fine tune the DHCP functionality by defining
1921 CONFIG_BOOTP_* symbols:
1923 CONFIG_BOOTP_SUBNETMASK
1924 CONFIG_BOOTP_GATEWAY
1925 CONFIG_BOOTP_HOSTNAME
1926 CONFIG_BOOTP_NISDOMAIN
1927 CONFIG_BOOTP_BOOTPATH
1928 CONFIG_BOOTP_BOOTFILESIZE
1931 CONFIG_BOOTP_SEND_HOSTNAME
1932 CONFIG_BOOTP_NTPSERVER
1933 CONFIG_BOOTP_TIMEOFFSET
1934 CONFIG_BOOTP_VENDOREX
1935 CONFIG_BOOTP_MAY_FAIL
1937 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1938 environment variable, not the BOOTP server.
1940 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1941 after the configured retry count, the call will fail
1942 instead of starting over. This can be used to fail over
1943 to Link-local IP address configuration if the DHCP server
1946 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1947 serverip from a DHCP server, it is possible that more
1948 than one DNS serverip is offered to the client.
1949 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1950 serverip will be stored in the additional environment
1951 variable "dnsip2". The first DNS serverip is always
1952 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1955 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1956 to do a dynamic update of a DNS server. To do this, they
1957 need the hostname of the DHCP requester.
1958 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1959 of the "hostname" environment variable is passed as
1960 option 12 to the DHCP server.
1962 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1964 A 32bit value in microseconds for a delay between
1965 receiving a "DHCP Offer" and sending the "DHCP Request".
1966 This fixes a problem with certain DHCP servers that don't
1967 respond 100% of the time to a "DHCP request". E.g. On an
1968 AT91RM9200 processor running at 180MHz, this delay needed
1969 to be *at least* 15,000 usec before a Windows Server 2003
1970 DHCP server would reply 100% of the time. I recommend at
1971 least 50,000 usec to be safe. The alternative is to hope
1972 that one of the retries will be successful but note that
1973 the DHCP timeout and retry process takes a longer than
1976 - Link-local IP address negotiation:
1977 Negotiate with other link-local clients on the local network
1978 for an address that doesn't require explicit configuration.
1979 This is especially useful if a DHCP server cannot be guaranteed
1980 to exist in all environments that the device must operate.
1982 See doc/README.link-local for more information.
1985 CONFIG_CDP_DEVICE_ID
1987 The device id used in CDP trigger frames.
1989 CONFIG_CDP_DEVICE_ID_PREFIX
1991 A two character string which is prefixed to the MAC address
1996 A printf format string which contains the ascii name of
1997 the port. Normally is set to "eth%d" which sets
1998 eth0 for the first Ethernet, eth1 for the second etc.
2000 CONFIG_CDP_CAPABILITIES
2002 A 32bit integer which indicates the device capabilities;
2003 0x00000010 for a normal host which does not forwards.
2007 An ascii string containing the version of the software.
2011 An ascii string containing the name of the platform.
2015 A 32bit integer sent on the trigger.
2017 CONFIG_CDP_POWER_CONSUMPTION
2019 A 16bit integer containing the power consumption of the
2020 device in .1 of milliwatts.
2022 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2024 A byte containing the id of the VLAN.
2026 - Status LED: CONFIG_STATUS_LED
2028 Several configurations allow to display the current
2029 status using a LED. For instance, the LED will blink
2030 fast while running U-Boot code, stop blinking as
2031 soon as a reply to a BOOTP request was received, and
2032 start blinking slow once the Linux kernel is running
2033 (supported by a status LED driver in the Linux
2034 kernel). Defining CONFIG_STATUS_LED enables this
2040 The status LED can be connected to a GPIO pin.
2041 In such cases, the gpio_led driver can be used as a
2042 status LED backend implementation. Define CONFIG_GPIO_LED
2043 to include the gpio_led driver in the U-Boot binary.
2045 CONFIG_GPIO_LED_INVERTED_TABLE
2046 Some GPIO connected LEDs may have inverted polarity in which
2047 case the GPIO high value corresponds to LED off state and
2048 GPIO low value corresponds to LED on state.
2049 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2050 with a list of GPIO LEDs that have inverted polarity.
2052 - CAN Support: CONFIG_CAN_DRIVER
2054 Defining CONFIG_CAN_DRIVER enables CAN driver support
2055 on those systems that support this (optional)
2056 feature, like the TQM8xxL modules.
2058 - I2C Support: CONFIG_SYS_I2C
2060 This enable the NEW i2c subsystem, and will allow you to use
2061 i2c commands at the u-boot command line (as long as you set
2062 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2063 based realtime clock chips or other i2c devices. See
2064 common/cmd_i2c.c for a description of the command line
2067 ported i2c driver to the new framework:
2068 - drivers/i2c/soft_i2c.c:
2069 - activate first bus with CONFIG_SYS_I2C_SOFT define
2070 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2071 for defining speed and slave address
2072 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2073 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2074 for defining speed and slave address
2075 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2076 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2077 for defining speed and slave address
2078 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2079 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2080 for defining speed and slave address
2082 - drivers/i2c/fsl_i2c.c:
2083 - activate i2c driver with CONFIG_SYS_I2C_FSL
2084 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2085 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2086 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2088 - If your board supports a second fsl i2c bus, define
2089 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2090 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2091 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2094 - drivers/i2c/tegra_i2c.c:
2095 - activate this driver with CONFIG_SYS_I2C_TEGRA
2096 - This driver adds 4 i2c buses with a fix speed from
2097 100000 and the slave addr 0!
2099 - drivers/i2c/ppc4xx_i2c.c
2100 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2101 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2102 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2104 - drivers/i2c/i2c_mxc.c
2105 - activate this driver with CONFIG_SYS_I2C_MXC
2106 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2107 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2108 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2109 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2110 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2111 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2112 If thoses defines are not set, default value is 100000
2113 for speed, and 0 for slave.
2115 - drivers/i2c/rcar_i2c.c:
2116 - activate this driver with CONFIG_SYS_I2C_RCAR
2117 - This driver adds 4 i2c buses
2119 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2120 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2121 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2122 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2123 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2124 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2125 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2126 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2127 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2129 - drivers/i2c/sh_i2c.c:
2130 - activate this driver with CONFIG_SYS_I2C_SH
2131 - This driver adds from 2 to 5 i2c buses
2133 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2134 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2135 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2136 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2137 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2138 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2139 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2140 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2141 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2142 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2143 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2144 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2145 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2147 - drivers/i2c/omap24xx_i2c.c
2148 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2149 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2150 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2151 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2152 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2153 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2154 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2155 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2156 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2157 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2158 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2160 - drivers/i2c/zynq_i2c.c
2161 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2162 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2163 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2165 - drivers/i2c/s3c24x0_i2c.c:
2166 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2167 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2168 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2169 with a fix speed from 100000 and the slave addr 0!
2173 CONFIG_SYS_NUM_I2C_BUSES
2174 Hold the number of i2c busses you want to use. If you
2175 don't use/have i2c muxes on your i2c bus, this
2176 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2179 CONFIG_SYS_I2C_DIRECT_BUS
2180 define this, if you don't use i2c muxes on your hardware.
2181 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2184 CONFIG_SYS_I2C_MAX_HOPS
2185 define how many muxes are maximal consecutively connected
2186 on one i2c bus. If you not use i2c muxes, omit this
2189 CONFIG_SYS_I2C_BUSES
2190 hold a list of busses you want to use, only used if
2191 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2192 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2193 CONFIG_SYS_NUM_I2C_BUSES = 9:
2195 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2196 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2197 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2198 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2199 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2200 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2201 {1, {I2C_NULL_HOP}}, \
2202 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2203 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2207 bus 0 on adapter 0 without a mux
2208 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2209 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2210 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2211 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2212 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2213 bus 6 on adapter 1 without a mux
2214 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2215 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2217 If you do not have i2c muxes on your board, omit this define.
2219 - Legacy I2C Support: CONFIG_HARD_I2C
2221 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2222 provides the following compelling advantages:
2224 - more than one i2c adapter is usable
2225 - approved multibus support
2226 - better i2c mux support
2228 ** Please consider updating your I2C driver now. **
2230 These enable legacy I2C serial bus commands. Defining
2231 CONFIG_HARD_I2C will include the appropriate I2C driver
2232 for the selected CPU.
2234 This will allow you to use i2c commands at the u-boot
2235 command line (as long as you set CONFIG_CMD_I2C in
2236 CONFIG_COMMANDS) and communicate with i2c based realtime
2237 clock chips. See common/cmd_i2c.c for a description of the
2238 command line interface.
2240 CONFIG_HARD_I2C selects a hardware I2C controller.
2242 There are several other quantities that must also be
2243 defined when you define CONFIG_HARD_I2C.
2245 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2246 to be the frequency (in Hz) at which you wish your i2c bus
2247 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2248 the CPU's i2c node address).
2250 Now, the u-boot i2c code for the mpc8xx
2251 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2252 and so its address should therefore be cleared to 0 (See,
2253 eg, MPC823e User's Manual p.16-473). So, set
2254 CONFIG_SYS_I2C_SLAVE to 0.
2256 CONFIG_SYS_I2C_INIT_MPC5XXX
2258 When a board is reset during an i2c bus transfer
2259 chips might think that the current transfer is still
2260 in progress. Reset the slave devices by sending start
2261 commands until the slave device responds.
2263 That's all that's required for CONFIG_HARD_I2C.
2265 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2266 then the following macros need to be defined (examples are
2267 from include/configs/lwmon.h):
2271 (Optional). Any commands necessary to enable the I2C
2272 controller or configure ports.
2274 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2278 (Only for MPC8260 CPU). The I/O port to use (the code
2279 assumes both bits are on the same port). Valid values
2280 are 0..3 for ports A..D.
2284 The code necessary to make the I2C data line active
2285 (driven). If the data line is open collector, this
2288 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2292 The code necessary to make the I2C data line tri-stated
2293 (inactive). If the data line is open collector, this
2296 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2300 Code that returns true if the I2C data line is high,
2303 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2307 If <bit> is true, sets the I2C data line high. If it
2308 is false, it clears it (low).
2310 eg: #define I2C_SDA(bit) \
2311 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2312 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2316 If <bit> is true, sets the I2C clock line high. If it
2317 is false, it clears it (low).
2319 eg: #define I2C_SCL(bit) \
2320 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2321 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2325 This delay is invoked four times per clock cycle so this
2326 controls the rate of data transfer. The data rate thus
2327 is 1 / (I2C_DELAY * 4). Often defined to be something
2330 #define I2C_DELAY udelay(2)
2332 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2334 If your arch supports the generic GPIO framework (asm/gpio.h),
2335 then you may alternatively define the two GPIOs that are to be
2336 used as SCL / SDA. Any of the previous I2C_xxx macros will
2337 have GPIO-based defaults assigned to them as appropriate.
2339 You should define these to the GPIO value as given directly to
2340 the generic GPIO functions.
2342 CONFIG_SYS_I2C_INIT_BOARD
2344 When a board is reset during an i2c bus transfer
2345 chips might think that the current transfer is still
2346 in progress. On some boards it is possible to access
2347 the i2c SCLK line directly, either by using the
2348 processor pin as a GPIO or by having a second pin
2349 connected to the bus. If this option is defined a
2350 custom i2c_init_board() routine in boards/xxx/board.c
2351 is run early in the boot sequence.
2353 CONFIG_SYS_I2C_BOARD_LATE_INIT
2355 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2356 defined a custom i2c_board_late_init() routine in
2357 boards/xxx/board.c is run AFTER the operations in i2c_init()
2358 is completed. This callpoint can be used to unreset i2c bus
2359 using CPU i2c controller register accesses for CPUs whose i2c
2360 controller provide such a method. It is called at the end of
2361 i2c_init() to allow i2c_init operations to setup the i2c bus
2362 controller on the CPU (e.g. setting bus speed & slave address).
2364 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2366 This option enables configuration of bi_iic_fast[] flags
2367 in u-boot bd_info structure based on u-boot environment
2368 variable "i2cfast". (see also i2cfast)
2370 CONFIG_I2C_MULTI_BUS
2372 This option allows the use of multiple I2C buses, each of which
2373 must have a controller. At any point in time, only one bus is
2374 active. To switch to a different bus, use the 'i2c dev' command.
2375 Note that bus numbering is zero-based.
2377 CONFIG_SYS_I2C_NOPROBES
2379 This option specifies a list of I2C devices that will be skipped
2380 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2381 is set, specify a list of bus-device pairs. Otherwise, specify
2382 a 1D array of device addresses
2385 #undef CONFIG_I2C_MULTI_BUS
2386 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2388 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2390 #define CONFIG_I2C_MULTI_BUS
2391 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2393 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2395 CONFIG_SYS_SPD_BUS_NUM
2397 If defined, then this indicates the I2C bus number for DDR SPD.
2398 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2400 CONFIG_SYS_RTC_BUS_NUM
2402 If defined, then this indicates the I2C bus number for the RTC.
2403 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2405 CONFIG_SYS_DTT_BUS_NUM
2407 If defined, then this indicates the I2C bus number for the DTT.
2408 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2410 CONFIG_SYS_I2C_DTT_ADDR:
2412 If defined, specifies the I2C address of the DTT device.
2413 If not defined, then U-Boot uses predefined value for
2414 specified DTT device.
2416 CONFIG_SOFT_I2C_READ_REPEATED_START
2418 defining this will force the i2c_read() function in
2419 the soft_i2c driver to perform an I2C repeated start
2420 between writing the address pointer and reading the
2421 data. If this define is omitted the default behaviour
2422 of doing a stop-start sequence will be used. Most I2C
2423 devices can use either method, but some require one or
2426 - SPI Support: CONFIG_SPI
2428 Enables SPI driver (so far only tested with
2429 SPI EEPROM, also an instance works with Crystal A/D and
2430 D/As on the SACSng board)
2434 Enables the driver for SPI controller on SuperH. Currently
2435 only SH7757 is supported.
2439 Enables extended (16-bit) SPI EEPROM addressing.
2440 (symmetrical to CONFIG_I2C_X)
2444 Enables a software (bit-bang) SPI driver rather than
2445 using hardware support. This is a general purpose
2446 driver that only requires three general I/O port pins
2447 (two outputs, one input) to function. If this is
2448 defined, the board configuration must define several
2449 SPI configuration items (port pins to use, etc). For
2450 an example, see include/configs/sacsng.h.
2454 Enables a hardware SPI driver for general-purpose reads
2455 and writes. As with CONFIG_SOFT_SPI, the board configuration
2456 must define a list of chip-select function pointers.
2457 Currently supported on some MPC8xxx processors. For an
2458 example, see include/configs/mpc8349emds.h.
2462 Enables the driver for the SPI controllers on i.MX and MXC
2463 SoCs. Currently i.MX31/35/51 are supported.
2465 - FPGA Support: CONFIG_FPGA
2467 Enables FPGA subsystem.
2469 CONFIG_FPGA_<vendor>
2471 Enables support for specific chip vendors.
2474 CONFIG_FPGA_<family>
2476 Enables support for FPGA family.
2477 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2481 Specify the number of FPGA devices to support.
2483 CONFIG_SYS_FPGA_PROG_FEEDBACK
2485 Enable printing of hash marks during FPGA configuration.
2487 CONFIG_SYS_FPGA_CHECK_BUSY
2489 Enable checks on FPGA configuration interface busy
2490 status by the configuration function. This option
2491 will require a board or device specific function to
2496 If defined, a function that provides delays in the FPGA
2497 configuration driver.
2499 CONFIG_SYS_FPGA_CHECK_CTRLC
2500 Allow Control-C to interrupt FPGA configuration
2502 CONFIG_SYS_FPGA_CHECK_ERROR
2504 Check for configuration errors during FPGA bitfile
2505 loading. For example, abort during Virtex II
2506 configuration if the INIT_B line goes low (which
2507 indicated a CRC error).
2509 CONFIG_SYS_FPGA_WAIT_INIT
2511 Maximum time to wait for the INIT_B line to deassert
2512 after PROB_B has been deasserted during a Virtex II
2513 FPGA configuration sequence. The default time is 500
2516 CONFIG_SYS_FPGA_WAIT_BUSY
2518 Maximum time to wait for BUSY to deassert during
2519 Virtex II FPGA configuration. The default is 5 ms.
2521 CONFIG_SYS_FPGA_WAIT_CONFIG
2523 Time to wait after FPGA configuration. The default is
2526 - Configuration Management:
2529 If defined, this string will be added to the U-Boot
2530 version information (U_BOOT_VERSION)
2532 - Vendor Parameter Protection:
2534 U-Boot considers the values of the environment
2535 variables "serial#" (Board Serial Number) and
2536 "ethaddr" (Ethernet Address) to be parameters that
2537 are set once by the board vendor / manufacturer, and
2538 protects these variables from casual modification by
2539 the user. Once set, these variables are read-only,
2540 and write or delete attempts are rejected. You can
2541 change this behaviour:
2543 If CONFIG_ENV_OVERWRITE is #defined in your config
2544 file, the write protection for vendor parameters is
2545 completely disabled. Anybody can change or delete
2548 Alternatively, if you #define _both_ CONFIG_ETHADDR
2549 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2550 Ethernet address is installed in the environment,
2551 which can be changed exactly ONCE by the user. [The
2552 serial# is unaffected by this, i. e. it remains
2555 The same can be accomplished in a more flexible way
2556 for any variable by configuring the type of access
2557 to allow for those variables in the ".flags" variable
2558 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2563 Define this variable to enable the reservation of
2564 "protected RAM", i. e. RAM which is not overwritten
2565 by U-Boot. Define CONFIG_PRAM to hold the number of
2566 kB you want to reserve for pRAM. You can overwrite
2567 this default value by defining an environment
2568 variable "pram" to the number of kB you want to
2569 reserve. Note that the board info structure will
2570 still show the full amount of RAM. If pRAM is
2571 reserved, a new environment variable "mem" will
2572 automatically be defined to hold the amount of
2573 remaining RAM in a form that can be passed as boot
2574 argument to Linux, for instance like that:
2576 setenv bootargs ... mem=\${mem}
2579 This way you can tell Linux not to use this memory,
2580 either, which results in a memory region that will
2581 not be affected by reboots.
2583 *WARNING* If your board configuration uses automatic
2584 detection of the RAM size, you must make sure that
2585 this memory test is non-destructive. So far, the
2586 following board configurations are known to be
2589 IVMS8, IVML24, SPD8xx, TQM8xxL,
2590 HERMES, IP860, RPXlite, LWMON,
2593 - Access to physical memory region (> 4GB)
2594 Some basic support is provided for operations on memory not
2595 normally accessible to U-Boot - e.g. some architectures
2596 support access to more than 4GB of memory on 32-bit
2597 machines using physical address extension or similar.
2598 Define CONFIG_PHYSMEM to access this basic support, which
2599 currently only supports clearing the memory.
2604 Define this variable to stop the system in case of a
2605 fatal error, so that you have to reset it manually.
2606 This is probably NOT a good idea for an embedded
2607 system where you want the system to reboot
2608 automatically as fast as possible, but it may be
2609 useful during development since you can try to debug
2610 the conditions that lead to the situation.
2612 CONFIG_NET_RETRY_COUNT
2614 This variable defines the number of retries for
2615 network operations like ARP, RARP, TFTP, or BOOTP
2616 before giving up the operation. If not defined, a
2617 default value of 5 is used.
2621 Timeout waiting for an ARP reply in milliseconds.
2625 Timeout in milliseconds used in NFS protocol.
2626 If you encounter "ERROR: Cannot umount" in nfs command,
2627 try longer timeout such as
2628 #define CONFIG_NFS_TIMEOUT 10000UL
2630 - Command Interpreter:
2631 CONFIG_AUTO_COMPLETE
2633 Enable auto completion of commands using TAB.
2635 Note that this feature has NOT been implemented yet
2636 for the "hush" shell.
2639 CONFIG_SYS_HUSH_PARSER
2641 Define this variable to enable the "hush" shell (from
2642 Busybox) as command line interpreter, thus enabling
2643 powerful command line syntax like
2644 if...then...else...fi conditionals or `&&' and '||'
2645 constructs ("shell scripts").
2647 If undefined, you get the old, much simpler behaviour
2648 with a somewhat smaller memory footprint.
2651 CONFIG_SYS_PROMPT_HUSH_PS2
2653 This defines the secondary prompt string, which is
2654 printed when the command interpreter needs more input
2655 to complete a command. Usually "> ".
2659 In the current implementation, the local variables
2660 space and global environment variables space are
2661 separated. Local variables are those you define by
2662 simply typing `name=value'. To access a local
2663 variable later on, you have write `$name' or
2664 `${name}'; to execute the contents of a variable
2665 directly type `$name' at the command prompt.
2667 Global environment variables are those you use
2668 setenv/printenv to work with. To run a command stored
2669 in such a variable, you need to use the run command,
2670 and you must not use the '$' sign to access them.
2672 To store commands and special characters in a
2673 variable, please use double quotation marks
2674 surrounding the whole text of the variable, instead
2675 of the backslashes before semicolons and special
2678 - Commandline Editing and History:
2679 CONFIG_CMDLINE_EDITING
2681 Enable editing and History functions for interactive
2682 commandline input operations
2684 - Default Environment:
2685 CONFIG_EXTRA_ENV_SETTINGS
2687 Define this to contain any number of null terminated
2688 strings (variable = value pairs) that will be part of
2689 the default environment compiled into the boot image.
2691 For example, place something like this in your
2692 board's config file:
2694 #define CONFIG_EXTRA_ENV_SETTINGS \
2698 Warning: This method is based on knowledge about the
2699 internal format how the environment is stored by the
2700 U-Boot code. This is NOT an official, exported
2701 interface! Although it is unlikely that this format
2702 will change soon, there is no guarantee either.
2703 You better know what you are doing here.
2705 Note: overly (ab)use of the default environment is
2706 discouraged. Make sure to check other ways to preset
2707 the environment like the "source" command or the
2710 CONFIG_ENV_VARS_UBOOT_CONFIG
2712 Define this in order to add variables describing the
2713 U-Boot build configuration to the default environment.
2714 These will be named arch, cpu, board, vendor, and soc.
2716 Enabling this option will cause the following to be defined:
2724 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2726 Define this in order to add variables describing certain
2727 run-time determined information about the hardware to the
2728 environment. These will be named board_name, board_rev.
2730 CONFIG_DELAY_ENVIRONMENT
2732 Normally the environment is loaded when the board is
2733 intialised so that it is available to U-Boot. This inhibits
2734 that so that the environment is not available until
2735 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2736 this is instead controlled by the value of
2737 /config/load-environment.
2739 - DataFlash Support:
2740 CONFIG_HAS_DATAFLASH
2742 Defining this option enables DataFlash features and
2743 allows to read/write in Dataflash via the standard
2746 - Serial Flash support
2749 Defining this option enables SPI flash commands
2750 'sf probe/read/write/erase/update'.
2752 Usage requires an initial 'probe' to define the serial
2753 flash parameters, followed by read/write/erase/update
2756 The following defaults may be provided by the platform
2757 to handle the common case when only a single serial
2758 flash is present on the system.
2760 CONFIG_SF_DEFAULT_BUS Bus identifier
2761 CONFIG_SF_DEFAULT_CS Chip-select
2762 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2763 CONFIG_SF_DEFAULT_SPEED in Hz
2767 Define this option to include a destructive SPI flash
2770 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2772 Define this option to use the Bank addr/Extended addr
2773 support on SPI flashes which has size > 16Mbytes.
2775 CONFIG_SF_DUAL_FLASH Dual flash memories
2777 Define this option to use dual flash support where two flash
2778 memories can be connected with a given cs line.
2779 currently Xilinx Zynq qspi support these type of connections.
2781 - SystemACE Support:
2784 Adding this option adds support for Xilinx SystemACE
2785 chips attached via some sort of local bus. The address
2786 of the chip must also be defined in the
2787 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2789 #define CONFIG_SYSTEMACE
2790 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2792 When SystemACE support is added, the "ace" device type
2793 becomes available to the fat commands, i.e. fatls.
2795 - TFTP Fixed UDP Port:
2798 If this is defined, the environment variable tftpsrcp
2799 is used to supply the TFTP UDP source port value.
2800 If tftpsrcp isn't defined, the normal pseudo-random port
2801 number generator is used.
2803 Also, the environment variable tftpdstp is used to supply
2804 the TFTP UDP destination port value. If tftpdstp isn't
2805 defined, the normal port 69 is used.
2807 The purpose for tftpsrcp is to allow a TFTP server to
2808 blindly start the TFTP transfer using the pre-configured
2809 target IP address and UDP port. This has the effect of
2810 "punching through" the (Windows XP) firewall, allowing
2811 the remainder of the TFTP transfer to proceed normally.
2812 A better solution is to properly configure the firewall,
2813 but sometimes that is not allowed.
2818 This enables a generic 'hash' command which can produce
2819 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2823 Enable the hash verify command (hash -v). This adds to code
2826 CONFIG_SHA1 - support SHA1 hashing
2827 CONFIG_SHA256 - support SHA256 hashing
2829 Note: There is also a sha1sum command, which should perhaps
2830 be deprecated in favour of 'hash sha1'.
2832 - Freescale i.MX specific commands:
2833 CONFIG_CMD_HDMIDETECT
2834 This enables 'hdmidet' command which returns true if an
2835 HDMI monitor is detected. This command is i.MX 6 specific.
2838 This enables the 'bmode' (bootmode) command for forcing
2839 a boot from specific media.
2841 This is useful for forcing the ROM's usb downloader to
2842 activate upon a watchdog reset which is nice when iterating
2843 on U-Boot. Using the reset button or running bmode normal
2844 will set it back to normal. This command currently
2845 supports i.MX53 and i.MX6.
2850 This enables the RSA algorithm used for FIT image verification
2851 in U-Boot. See doc/uImage/signature for more information.
2853 The signing part is build into mkimage regardless of this
2857 - Show boot progress:
2858 CONFIG_SHOW_BOOT_PROGRESS
2860 Defining this option allows to add some board-
2861 specific code (calling a user-provided function
2862 "show_boot_progress(int)") that enables you to show
2863 the system's boot progress on some display (for
2864 example, some LED's) on your board. At the moment,
2865 the following checkpoints are implemented:
2867 - Detailed boot stage timing
2869 Define this option to get detailed timing of each stage
2870 of the boot process.
2872 CONFIG_BOOTSTAGE_USER_COUNT
2873 This is the number of available user bootstage records.
2874 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2875 a new ID will be allocated from this stash. If you exceed
2876 the limit, recording will stop.
2878 CONFIG_BOOTSTAGE_REPORT
2879 Define this to print a report before boot, similar to this:
2881 Timer summary in microseconds:
2884 3,575,678 3,575,678 board_init_f start
2885 3,575,695 17 arch_cpu_init A9
2886 3,575,777 82 arch_cpu_init done
2887 3,659,598 83,821 board_init_r start
2888 3,910,375 250,777 main_loop
2889 29,916,167 26,005,792 bootm_start
2890 30,361,327 445,160 start_kernel
2892 CONFIG_CMD_BOOTSTAGE
2893 Add a 'bootstage' command which supports printing a report
2894 and un/stashing of bootstage data.
2896 CONFIG_BOOTSTAGE_FDT
2897 Stash the bootstage information in the FDT. A root 'bootstage'
2898 node is created with each bootstage id as a child. Each child
2899 has a 'name' property and either 'mark' containing the
2900 mark time in microsecond, or 'accum' containing the
2901 accumulated time for that bootstage id in microseconds.
2906 name = "board_init_f";
2915 Code in the Linux kernel can find this in /proc/devicetree.
2917 Legacy uImage format:
2920 1 common/cmd_bootm.c before attempting to boot an image
2921 -1 common/cmd_bootm.c Image header has bad magic number
2922 2 common/cmd_bootm.c Image header has correct magic number
2923 -2 common/cmd_bootm.c Image header has bad checksum
2924 3 common/cmd_bootm.c Image header has correct checksum
2925 -3 common/cmd_bootm.c Image data has bad checksum
2926 4 common/cmd_bootm.c Image data has correct checksum
2927 -4 common/cmd_bootm.c Image is for unsupported architecture
2928 5 common/cmd_bootm.c Architecture check OK
2929 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2930 6 common/cmd_bootm.c Image Type check OK
2931 -6 common/cmd_bootm.c gunzip uncompression error
2932 -7 common/cmd_bootm.c Unimplemented compression type
2933 7 common/cmd_bootm.c Uncompression OK
2934 8 common/cmd_bootm.c No uncompress/copy overwrite error
2935 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2937 9 common/image.c Start initial ramdisk verification
2938 -10 common/image.c Ramdisk header has bad magic number
2939 -11 common/image.c Ramdisk header has bad checksum
2940 10 common/image.c Ramdisk header is OK
2941 -12 common/image.c Ramdisk data has bad checksum
2942 11 common/image.c Ramdisk data has correct checksum
2943 12 common/image.c Ramdisk verification complete, start loading
2944 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2945 13 common/image.c Start multifile image verification
2946 14 common/image.c No initial ramdisk, no multifile, continue.
2948 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2950 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2951 -31 post/post.c POST test failed, detected by post_output_backlog()
2952 -32 post/post.c POST test failed, detected by post_run_single()
2954 34 common/cmd_doc.c before loading a Image from a DOC device
2955 -35 common/cmd_doc.c Bad usage of "doc" command
2956 35 common/cmd_doc.c correct usage of "doc" command
2957 -36 common/cmd_doc.c No boot device
2958 36 common/cmd_doc.c correct boot device
2959 -37 common/cmd_doc.c Unknown Chip ID on boot device
2960 37 common/cmd_doc.c correct chip ID found, device available
2961 -38 common/cmd_doc.c Read Error on boot device
2962 38 common/cmd_doc.c reading Image header from DOC device OK
2963 -39 common/cmd_doc.c Image header has bad magic number
2964 39 common/cmd_doc.c Image header has correct magic number
2965 -40 common/cmd_doc.c Error reading Image from DOC device
2966 40 common/cmd_doc.c Image header has correct magic number
2967 41 common/cmd_ide.c before loading a Image from a IDE device
2968 -42 common/cmd_ide.c Bad usage of "ide" command
2969 42 common/cmd_ide.c correct usage of "ide" command
2970 -43 common/cmd_ide.c No boot device
2971 43 common/cmd_ide.c boot device found
2972 -44 common/cmd_ide.c Device not available
2973 44 common/cmd_ide.c Device available
2974 -45 common/cmd_ide.c wrong partition selected
2975 45 common/cmd_ide.c partition selected
2976 -46 common/cmd_ide.c Unknown partition table
2977 46 common/cmd_ide.c valid partition table found
2978 -47 common/cmd_ide.c Invalid partition type
2979 47 common/cmd_ide.c correct partition type
2980 -48 common/cmd_ide.c Error reading Image Header on boot device
2981 48 common/cmd_ide.c reading Image Header from IDE device OK
2982 -49 common/cmd_ide.c Image header has bad magic number
2983 49 common/cmd_ide.c Image header has correct magic number
2984 -50 common/cmd_ide.c Image header has bad checksum
2985 50 common/cmd_ide.c Image header has correct checksum
2986 -51 common/cmd_ide.c Error reading Image from IDE device
2987 51 common/cmd_ide.c reading Image from IDE device OK
2988 52 common/cmd_nand.c before loading a Image from a NAND device
2989 -53 common/cmd_nand.c Bad usage of "nand" command
2990 53 common/cmd_nand.c correct usage of "nand" command
2991 -54 common/cmd_nand.c No boot device
2992 54 common/cmd_nand.c boot device found
2993 -55 common/cmd_nand.c Unknown Chip ID on boot device
2994 55 common/cmd_nand.c correct chip ID found, device available
2995 -56 common/cmd_nand.c Error reading Image Header on boot device
2996 56 common/cmd_nand.c reading Image Header from NAND device OK
2997 -57 common/cmd_nand.c Image header has bad magic number
2998 57 common/cmd_nand.c Image header has correct magic number
2999 -58 common/cmd_nand.c Error reading Image from NAND device
3000 58 common/cmd_nand.c reading Image from NAND device OK
3002 -60 common/env_common.c Environment has a bad CRC, using default
3004 64 net/eth.c starting with Ethernet configuration.
3005 -64 net/eth.c no Ethernet found.
3006 65 net/eth.c Ethernet found.
3008 -80 common/cmd_net.c usage wrong
3009 80 common/cmd_net.c before calling NetLoop()
3010 -81 common/cmd_net.c some error in NetLoop() occurred
3011 81 common/cmd_net.c NetLoop() back without error
3012 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3013 82 common/cmd_net.c trying automatic boot
3014 83 common/cmd_net.c running "source" command
3015 -83 common/cmd_net.c some error in automatic boot or "source" command
3016 84 common/cmd_net.c end without errors
3021 100 common/cmd_bootm.c Kernel FIT Image has correct format
3022 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3023 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3024 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3025 102 common/cmd_bootm.c Kernel unit name specified
3026 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3027 103 common/cmd_bootm.c Found configuration node
3028 104 common/cmd_bootm.c Got kernel subimage node offset
3029 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3030 105 common/cmd_bootm.c Kernel subimage hash verification OK
3031 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3032 106 common/cmd_bootm.c Architecture check OK
3033 -106 common/cmd_bootm.c Kernel subimage has wrong type
3034 107 common/cmd_bootm.c Kernel subimage type OK
3035 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3036 108 common/cmd_bootm.c Got kernel subimage data/size
3037 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3038 -109 common/cmd_bootm.c Can't get kernel subimage type
3039 -110 common/cmd_bootm.c Can't get kernel subimage comp
3040 -111 common/cmd_bootm.c Can't get kernel subimage os
3041 -112 common/cmd_bootm.c Can't get kernel subimage load address
3042 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3044 120 common/image.c Start initial ramdisk verification
3045 -120 common/image.c Ramdisk FIT image has incorrect format
3046 121 common/image.c Ramdisk FIT image has correct format
3047 122 common/image.c No ramdisk subimage unit name, using configuration
3048 -122 common/image.c Can't get configuration for ramdisk subimage
3049 123 common/image.c Ramdisk unit name specified
3050 -124 common/image.c Can't get ramdisk subimage node offset
3051 125 common/image.c Got ramdisk subimage node offset
3052 -125 common/image.c Ramdisk subimage hash verification failed
3053 126 common/image.c Ramdisk subimage hash verification OK
3054 -126 common/image.c Ramdisk subimage for unsupported architecture
3055 127 common/image.c Architecture check OK
3056 -127 common/image.c Can't get ramdisk subimage data/size
3057 128 common/image.c Got ramdisk subimage data/size
3058 129 common/image.c Can't get ramdisk load address
3059 -129 common/image.c Got ramdisk load address
3061 -130 common/cmd_doc.c Incorrect FIT image format
3062 131 common/cmd_doc.c FIT image format OK
3064 -140 common/cmd_ide.c Incorrect FIT image format
3065 141 common/cmd_ide.c FIT image format OK
3067 -150 common/cmd_nand.c Incorrect FIT image format
3068 151 common/cmd_nand.c FIT image format OK
3070 - FIT image support:
3072 Enable support for the FIT uImage format.
3074 CONFIG_FIT_BEST_MATCH
3075 When no configuration is explicitly selected, default to the
3076 one whose fdt's compatibility field best matches that of
3077 U-Boot itself. A match is considered "best" if it matches the
3078 most specific compatibility entry of U-Boot's fdt's root node.
3079 The order of entries in the configuration's fdt is ignored.
3081 CONFIG_FIT_SIGNATURE
3082 This option enables signature verification of FIT uImages,
3083 using a hash signed and verified using RSA. See
3084 doc/uImage.FIT/signature.txt for more details.
3086 - Standalone program support:
3087 CONFIG_STANDALONE_LOAD_ADDR
3089 This option defines a board specific value for the
3090 address where standalone program gets loaded, thus
3091 overwriting the architecture dependent default
3094 - Frame Buffer Address:
3097 Define CONFIG_FB_ADDR if you want to use specific
3098 address for frame buffer. This is typically the case
3099 when using a graphics controller has separate video
3100 memory. U-Boot will then place the frame buffer at
3101 the given address instead of dynamically reserving it
3102 in system RAM by calling lcd_setmem(), which grabs
3103 the memory for the frame buffer depending on the
3104 configured panel size.
3106 Please see board_init_f function.
3108 - Automatic software updates via TFTP server
3110 CONFIG_UPDATE_TFTP_CNT_MAX
3111 CONFIG_UPDATE_TFTP_MSEC_MAX
3113 These options enable and control the auto-update feature;
3114 for a more detailed description refer to doc/README.update.
3116 - MTD Support (mtdparts command, UBI support)
3119 Adds the MTD device infrastructure from the Linux kernel.
3120 Needed for mtdparts command support.
3122 CONFIG_MTD_PARTITIONS
3124 Adds the MTD partitioning infrastructure from the Linux
3125 kernel. Needed for UBI support.
3130 Adds commands for interacting with MTD partitions formatted
3131 with the UBI flash translation layer
3133 Requires also defining CONFIG_RBTREE
3135 CONFIG_UBI_SILENCE_MSG
3137 Make the verbose messages from UBI stop printing. This leaves
3138 warnings and errors enabled.
3143 Adds commands for interacting with UBI volumes formatted as
3144 UBIFS. UBIFS is read-only in u-boot.
3146 Requires UBI support as well as CONFIG_LZO
3148 CONFIG_UBIFS_SILENCE_MSG
3150 Make the verbose messages from UBIFS stop printing. This leaves
3151 warnings and errors enabled.
3155 Enable building of SPL globally.
3158 LDSCRIPT for linking the SPL binary.
3160 CONFIG_SPL_MAX_FOOTPRINT
3161 Maximum size in memory allocated to the SPL, BSS included.
3162 When defined, the linker checks that the actual memory
3163 used by SPL from _start to __bss_end does not exceed it.
3164 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3165 must not be both defined at the same time.
3168 Maximum size of the SPL image (text, data, rodata, and
3169 linker lists sections), BSS excluded.
3170 When defined, the linker checks that the actual size does
3173 CONFIG_SPL_TEXT_BASE
3174 TEXT_BASE for linking the SPL binary.
3176 CONFIG_SPL_RELOC_TEXT_BASE
3177 Address to relocate to. If unspecified, this is equal to
3178 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3180 CONFIG_SPL_BSS_START_ADDR
3181 Link address for the BSS within the SPL binary.
3183 CONFIG_SPL_BSS_MAX_SIZE
3184 Maximum size in memory allocated to the SPL BSS.
3185 When defined, the linker checks that the actual memory used
3186 by SPL from __bss_start to __bss_end does not exceed it.
3187 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3188 must not be both defined at the same time.
3191 Adress of the start of the stack SPL will use
3193 CONFIG_SPL_RELOC_STACK
3194 Adress of the start of the stack SPL will use after
3195 relocation. If unspecified, this is equal to
3198 CONFIG_SYS_SPL_MALLOC_START
3199 Starting address of the malloc pool used in SPL.
3201 CONFIG_SYS_SPL_MALLOC_SIZE
3202 The size of the malloc pool used in SPL.
3204 CONFIG_SPL_FRAMEWORK
3205 Enable the SPL framework under common/. This framework
3206 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3207 NAND loading of the Linux Kernel.
3209 CONFIG_SPL_DISPLAY_PRINT
3210 For ARM, enable an optional function to print more information
3211 about the running system.
3213 CONFIG_SPL_INIT_MINIMAL
3214 Arch init code should be built for a very small image
3216 CONFIG_SPL_LIBCOMMON_SUPPORT
3217 Support for common/libcommon.o in SPL binary
3219 CONFIG_SPL_LIBDISK_SUPPORT
3220 Support for disk/libdisk.o in SPL binary
3222 CONFIG_SPL_I2C_SUPPORT
3223 Support for drivers/i2c/libi2c.o in SPL binary
3225 CONFIG_SPL_GPIO_SUPPORT
3226 Support for drivers/gpio/libgpio.o in SPL binary
3228 CONFIG_SPL_MMC_SUPPORT
3229 Support for drivers/mmc/libmmc.o in SPL binary
3231 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3232 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3233 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3234 Address, size and partition on the MMC to load U-Boot from
3235 when the MMC is being used in raw mode.
3237 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3238 Sector to load kernel uImage from when MMC is being
3239 used in raw mode (for Falcon mode)
3241 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3242 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3243 Sector and number of sectors to load kernel argument
3244 parameters from when MMC is being used in raw mode
3247 CONFIG_SPL_FAT_SUPPORT
3248 Support for fs/fat/libfat.o in SPL binary
3250 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3251 Filename to read to load U-Boot when reading from FAT
3253 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3254 Filename to read to load kernel uImage when reading
3255 from FAT (for Falcon mode)
3257 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3258 Filename to read to load kernel argument parameters
3259 when reading from FAT (for Falcon mode)
3261 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3262 Set this for NAND SPL on PPC mpc83xx targets, so that
3263 start.S waits for the rest of the SPL to load before
3264 continuing (the hardware starts execution after just
3265 loading the first page rather than the full 4K).
3267 CONFIG_SPL_NAND_BASE
3268 Include nand_base.c in the SPL. Requires
3269 CONFIG_SPL_NAND_DRIVERS.
3271 CONFIG_SPL_NAND_DRIVERS
3272 SPL uses normal NAND drivers, not minimal drivers.
3275 Include standard software ECC in the SPL
3277 CONFIG_SPL_NAND_SIMPLE
3278 Support for NAND boot using simple NAND drivers that
3279 expose the cmd_ctrl() interface.
3281 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3282 Set for the SPL on PPC mpc8xxx targets, support for
3283 drivers/ddr/fsl/libddr.o in SPL binary.
3285 CONFIG_SPL_COMMON_INIT_DDR
3286 Set for common ddr init with serial presence detect in
3289 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3290 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3291 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3292 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3293 CONFIG_SYS_NAND_ECCBYTES
3294 Defines the size and behavior of the NAND that SPL uses
3297 CONFIG_SPL_NAND_BOOT
3298 Add support NAND boot
3300 CONFIG_SYS_NAND_U_BOOT_OFFS
3301 Location in NAND to read U-Boot from
3303 CONFIG_SYS_NAND_U_BOOT_DST
3304 Location in memory to load U-Boot to
3306 CONFIG_SYS_NAND_U_BOOT_SIZE
3307 Size of image to load
3309 CONFIG_SYS_NAND_U_BOOT_START
3310 Entry point in loaded image to jump to
3312 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3313 Define this if you need to first read the OOB and then the
3314 data. This is used for example on davinci plattforms.
3316 CONFIG_SPL_OMAP3_ID_NAND
3317 Support for an OMAP3-specific set of functions to return the
3318 ID and MFR of the first attached NAND chip, if present.
3320 CONFIG_SPL_SERIAL_SUPPORT
3321 Support for drivers/serial/libserial.o in SPL binary
3323 CONFIG_SPL_SPI_FLASH_SUPPORT
3324 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3326 CONFIG_SPL_SPI_SUPPORT
3327 Support for drivers/spi/libspi.o in SPL binary
3329 CONFIG_SPL_RAM_DEVICE
3330 Support for running image already present in ram, in SPL binary
3332 CONFIG_SPL_LIBGENERIC_SUPPORT
3333 Support for lib/libgeneric.o in SPL binary
3335 CONFIG_SPL_ENV_SUPPORT
3336 Support for the environment operating in SPL binary
3338 CONFIG_SPL_NET_SUPPORT
3339 Support for the net/libnet.o in SPL binary.
3340 It conflicts with SPL env from storage medium specified by
3341 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3344 Image offset to which the SPL should be padded before appending
3345 the SPL payload. By default, this is defined as
3346 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3347 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3348 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3351 Final target image containing SPL and payload. Some SPLs
3352 use an arch-specific makefile fragment instead, for
3353 example if more than one image needs to be produced.
3355 CONFIG_FIT_SPL_PRINT
3356 Printing information about a FIT image adds quite a bit of
3357 code to SPL. So this is normally disabled in SPL. Use this
3358 option to re-enable it. This will affect the output of the
3359 bootm command when booting a FIT image.
3363 Enable building of TPL globally.
3366 Image offset to which the TPL should be padded before appending
3367 the TPL payload. By default, this is defined as
3368 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3369 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3370 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3375 [so far only for SMDK2400 boards]
3377 - Modem support enable:
3378 CONFIG_MODEM_SUPPORT
3380 - RTS/CTS Flow control enable:
3383 - Modem debug support:
3384 CONFIG_MODEM_SUPPORT_DEBUG
3386 Enables debugging stuff (char screen[1024], dbg())
3387 for modem support. Useful only with BDI2000.
3389 - Interrupt support (PPC):
3391 There are common interrupt_init() and timer_interrupt()
3392 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3393 for CPU specific initialization. interrupt_init_cpu()
3394 should set decrementer_count to appropriate value. If
3395 CPU resets decrementer automatically after interrupt
3396 (ppc4xx) it should set decrementer_count to zero.
3397 timer_interrupt() calls timer_interrupt_cpu() for CPU
3398 specific handling. If board has watchdog / status_led
3399 / other_activity_monitor it works automatically from
3400 general timer_interrupt().
3404 In the target system modem support is enabled when a
3405 specific key (key combination) is pressed during
3406 power-on. Otherwise U-Boot will boot normally
3407 (autoboot). The key_pressed() function is called from
3408 board_init(). Currently key_pressed() is a dummy
3409 function, returning 1 and thus enabling modem
3412 If there are no modem init strings in the
3413 environment, U-Boot proceed to autoboot; the
3414 previous output (banner, info printfs) will be
3417 See also: doc/README.Modem
3419 Board initialization settings:
3420 ------------------------------
3422 During Initialization u-boot calls a number of board specific functions
3423 to allow the preparation of board specific prerequisites, e.g. pin setup
3424 before drivers are initialized. To enable these callbacks the
3425 following configuration macros have to be defined. Currently this is
3426 architecture specific, so please check arch/your_architecture/lib/board.c
3427 typically in board_init_f() and board_init_r().
3429 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3430 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3431 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3432 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3434 Configuration Settings:
3435 -----------------------
3437 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3438 undefine this when you're short of memory.
3440 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3441 width of the commands listed in the 'help' command output.
3443 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3444 prompt for user input.
3446 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3448 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3450 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3452 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3453 the application (usually a Linux kernel) when it is
3456 - CONFIG_SYS_BAUDRATE_TABLE:
3457 List of legal baudrate settings for this board.
3459 - CONFIG_SYS_CONSOLE_INFO_QUIET
3460 Suppress display of console information at boot.
3462 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3463 If the board specific function
3464 extern int overwrite_console (void);
3465 returns 1, the stdin, stderr and stdout are switched to the
3466 serial port, else the settings in the environment are used.
3468 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3469 Enable the call to overwrite_console().
3471 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3472 Enable overwrite of previous console environment settings.
3474 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3475 Begin and End addresses of the area used by the
3478 - CONFIG_SYS_ALT_MEMTEST:
3479 Enable an alternate, more extensive memory test.
3481 - CONFIG_SYS_MEMTEST_SCRATCH:
3482 Scratch address used by the alternate memory test
3483 You only need to set this if address zero isn't writeable
3485 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3486 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3487 this specified memory area will get subtracted from the top
3488 (end) of RAM and won't get "touched" at all by U-Boot. By
3489 fixing up gd->ram_size the Linux kernel should gets passed
3490 the now "corrected" memory size and won't touch it either.
3491 This should work for arch/ppc and arch/powerpc. Only Linux
3492 board ports in arch/powerpc with bootwrapper support that
3493 recalculate the memory size from the SDRAM controller setup
3494 will have to get fixed in Linux additionally.
3496 This option can be used as a workaround for the 440EPx/GRx
3497 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3500 WARNING: Please make sure that this value is a multiple of
3501 the Linux page size (normally 4k). If this is not the case,
3502 then the end address of the Linux memory will be located at a
3503 non page size aligned address and this could cause major
3506 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3507 Enable temporary baudrate change while serial download
3509 - CONFIG_SYS_SDRAM_BASE:
3510 Physical start address of SDRAM. _Must_ be 0 here.
3512 - CONFIG_SYS_MBIO_BASE:
3513 Physical start address of Motherboard I/O (if using a
3516 - CONFIG_SYS_FLASH_BASE:
3517 Physical start address of Flash memory.
3519 - CONFIG_SYS_MONITOR_BASE:
3520 Physical start address of boot monitor code (set by
3521 make config files to be same as the text base address
3522 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3523 CONFIG_SYS_FLASH_BASE when booting from flash.
3525 - CONFIG_SYS_MONITOR_LEN:
3526 Size of memory reserved for monitor code, used to
3527 determine _at_compile_time_ (!) if the environment is
3528 embedded within the U-Boot image, or in a separate
3531 - CONFIG_SYS_MALLOC_LEN:
3532 Size of DRAM reserved for malloc() use.
3534 - CONFIG_SYS_BOOTM_LEN:
3535 Normally compressed uImages are limited to an
3536 uncompressed size of 8 MBytes. If this is not enough,
3537 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3538 to adjust this setting to your needs.
3540 - CONFIG_SYS_BOOTMAPSZ:
3541 Maximum size of memory mapped by the startup code of
3542 the Linux kernel; all data that must be processed by
3543 the Linux kernel (bd_info, boot arguments, FDT blob if
3544 used) must be put below this limit, unless "bootm_low"
3545 environment variable is defined and non-zero. In such case
3546 all data for the Linux kernel must be between "bootm_low"
3547 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3548 variable "bootm_mapsize" will override the value of
3549 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3550 then the value in "bootm_size" will be used instead.
3552 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3553 Enable initrd_high functionality. If defined then the
3554 initrd_high feature is enabled and the bootm ramdisk subcommand
3557 - CONFIG_SYS_BOOT_GET_CMDLINE:
3558 Enables allocating and saving kernel cmdline in space between
3559 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3561 - CONFIG_SYS_BOOT_GET_KBD:
3562 Enables allocating and saving a kernel copy of the bd_info in
3563 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3565 - CONFIG_SYS_MAX_FLASH_BANKS:
3566 Max number of Flash memory banks
3568 - CONFIG_SYS_MAX_FLASH_SECT:
3569 Max number of sectors on a Flash chip
3571 - CONFIG_SYS_FLASH_ERASE_TOUT:
3572 Timeout for Flash erase operations (in ms)
3574 - CONFIG_SYS_FLASH_WRITE_TOUT:
3575 Timeout for Flash write operations (in ms)
3577 - CONFIG_SYS_FLASH_LOCK_TOUT
3578 Timeout for Flash set sector lock bit operation (in ms)
3580 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3581 Timeout for Flash clear lock bits operation (in ms)
3583 - CONFIG_SYS_FLASH_PROTECTION
3584 If defined, hardware flash sectors protection is used
3585 instead of U-Boot software protection.
3587 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3589 Enable TFTP transfers directly to flash memory;
3590 without this option such a download has to be
3591 performed in two steps: (1) download to RAM, and (2)
3592 copy from RAM to flash.
3594 The two-step approach is usually more reliable, since
3595 you can check if the download worked before you erase
3596 the flash, but in some situations (when system RAM is
3597 too limited to allow for a temporary copy of the
3598 downloaded image) this option may be very useful.
3600 - CONFIG_SYS_FLASH_CFI:
3601 Define if the flash driver uses extra elements in the
3602 common flash structure for storing flash geometry.
3604 - CONFIG_FLASH_CFI_DRIVER
3605 This option also enables the building of the cfi_flash driver
3606 in the drivers directory
3608 - CONFIG_FLASH_CFI_MTD
3609 This option enables the building of the cfi_mtd driver
3610 in the drivers directory. The driver exports CFI flash
3613 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3614 Use buffered writes to flash.
3616 - CONFIG_FLASH_SPANSION_S29WS_N
3617 s29ws-n MirrorBit flash has non-standard addresses for buffered
3620 - CONFIG_SYS_FLASH_QUIET_TEST
3621 If this option is defined, the common CFI flash doesn't
3622 print it's warning upon not recognized FLASH banks. This
3623 is useful, if some of the configured banks are only
3624 optionally available.
3626 - CONFIG_FLASH_SHOW_PROGRESS
3627 If defined (must be an integer), print out countdown
3628 digits and dots. Recommended value: 45 (9..1) for 80
3629 column displays, 15 (3..1) for 40 column displays.
3631 - CONFIG_FLASH_VERIFY
3632 If defined, the content of the flash (destination) is compared
3633 against the source after the write operation. An error message
3634 will be printed when the contents are not identical.
3635 Please note that this option is useless in nearly all cases,
3636 since such flash programming errors usually are detected earlier
3637 while unprotecting/erasing/programming. Please only enable
3638 this option if you really know what you are doing.
3640 - CONFIG_SYS_RX_ETH_BUFFER:
3641 Defines the number of Ethernet receive buffers. On some
3642 Ethernet controllers it is recommended to set this value
3643 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3644 buffers can be full shortly after enabling the interface
3645 on high Ethernet traffic.
3646 Defaults to 4 if not defined.
3648 - CONFIG_ENV_MAX_ENTRIES
3650 Maximum number of entries in the hash table that is used
3651 internally to store the environment settings. The default
3652 setting is supposed to be generous and should work in most
3653 cases. This setting can be used to tune behaviour; see
3654 lib/hashtable.c for details.
3656 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3657 - CONFIG_ENV_FLAGS_LIST_STATIC
3658 Enable validation of the values given to environment variables when
3659 calling env set. Variables can be restricted to only decimal,
3660 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3661 the variables can also be restricted to IP address or MAC address.
3663 The format of the list is:
3664 type_attribute = [s|d|x|b|i|m]
3665 access_atribute = [a|r|o|c]
3666 attributes = type_attribute[access_atribute]
3667 entry = variable_name[:attributes]
3670 The type attributes are:
3671 s - String (default)
3674 b - Boolean ([1yYtT|0nNfF])
3678 The access attributes are:
3684 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3685 Define this to a list (string) to define the ".flags"
3686 envirnoment variable in the default or embedded environment.
3688 - CONFIG_ENV_FLAGS_LIST_STATIC
3689 Define this to a list (string) to define validation that
3690 should be done if an entry is not found in the ".flags"
3691 environment variable. To override a setting in the static
3692 list, simply add an entry for the same variable name to the
3695 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3696 If defined, don't allow the -f switch to env set override variable
3699 - CONFIG_SYS_GENERIC_BOARD
3700 This selects the architecture-generic board system instead of the
3701 architecture-specific board files. It is intended to move boards
3702 to this new framework over time. Defining this will disable the
3703 arch/foo/lib/board.c file and use common/board_f.c and
3704 common/board_r.c instead. To use this option your architecture
3705 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3706 its config.mk file). If you find problems enabling this option on
3707 your board please report the problem and send patches!
3709 - CONFIG_SYS_SYM_OFFSETS
3710 This is set by architectures that use offsets for link symbols
3711 instead of absolute values. So bss_start is obtained using an
3712 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3713 directly. You should not need to touch this setting.
3715 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3716 This is set by OMAP boards for the max time that reset should
3717 be asserted. See doc/README.omap-reset-time for details on how
3718 the value can be calulated on a given board.
3720 The following definitions that deal with the placement and management
3721 of environment data (variable area); in general, we support the
3722 following configurations:
3724 - CONFIG_BUILD_ENVCRC:
3726 Builds up envcrc with the target environment so that external utils
3727 may easily extract it and embed it in final U-Boot images.
3729 - CONFIG_ENV_IS_IN_FLASH:
3731 Define this if the environment is in flash memory.
3733 a) The environment occupies one whole flash sector, which is
3734 "embedded" in the text segment with the U-Boot code. This
3735 happens usually with "bottom boot sector" or "top boot
3736 sector" type flash chips, which have several smaller
3737 sectors at the start or the end. For instance, such a
3738 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3739 such a case you would place the environment in one of the
3740 4 kB sectors - with U-Boot code before and after it. With
3741 "top boot sector" type flash chips, you would put the
3742 environment in one of the last sectors, leaving a gap
3743 between U-Boot and the environment.
3745 - CONFIG_ENV_OFFSET:
3747 Offset of environment data (variable area) to the
3748 beginning of flash memory; for instance, with bottom boot
3749 type flash chips the second sector can be used: the offset
3750 for this sector is given here.
3752 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3756 This is just another way to specify the start address of
3757 the flash sector containing the environment (instead of
3760 - CONFIG_ENV_SECT_SIZE:
3762 Size of the sector containing the environment.
3765 b) Sometimes flash chips have few, equal sized, BIG sectors.
3766 In such a case you don't want to spend a whole sector for
3771 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3772 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3773 of this flash sector for the environment. This saves
3774 memory for the RAM copy of the environment.
3776 It may also save flash memory if you decide to use this
3777 when your environment is "embedded" within U-Boot code,
3778 since then the remainder of the flash sector could be used
3779 for U-Boot code. It should be pointed out that this is
3780 STRONGLY DISCOURAGED from a robustness point of view:
3781 updating the environment in flash makes it always
3782 necessary to erase the WHOLE sector. If something goes
3783 wrong before the contents has been restored from a copy in
3784 RAM, your target system will be dead.
3786 - CONFIG_ENV_ADDR_REDUND
3787 CONFIG_ENV_SIZE_REDUND
3789 These settings describe a second storage area used to hold
3790 a redundant copy of the environment data, so that there is
3791 a valid backup copy in case there is a power failure during
3792 a "saveenv" operation.
3794 BE CAREFUL! Any changes to the flash layout, and some changes to the
3795 source code will make it necessary to adapt <board>/u-boot.lds*
3799 - CONFIG_ENV_IS_IN_NVRAM:
3801 Define this if you have some non-volatile memory device
3802 (NVRAM, battery buffered SRAM) which you want to use for the
3808 These two #defines are used to determine the memory area you
3809 want to use for environment. It is assumed that this memory
3810 can just be read and written to, without any special
3813 BE CAREFUL! The first access to the environment happens quite early
3814 in U-Boot initalization (when we try to get the setting of for the
3815 console baudrate). You *MUST* have mapped your NVRAM area then, or
3818 Please note that even with NVRAM we still use a copy of the
3819 environment in RAM: we could work on NVRAM directly, but we want to
3820 keep settings there always unmodified except somebody uses "saveenv"
3821 to save the current settings.
3824 - CONFIG_ENV_IS_IN_EEPROM:
3826 Use this if you have an EEPROM or similar serial access
3827 device and a driver for it.
3829 - CONFIG_ENV_OFFSET:
3832 These two #defines specify the offset and size of the
3833 environment area within the total memory of your EEPROM.
3835 - CONFIG_SYS_I2C_EEPROM_ADDR:
3836 If defined, specified the chip address of the EEPROM device.
3837 The default address is zero.
3839 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3840 If defined, the number of bits used to address bytes in a
3841 single page in the EEPROM device. A 64 byte page, for example
3842 would require six bits.
3844 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3845 If defined, the number of milliseconds to delay between
3846 page writes. The default is zero milliseconds.
3848 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3849 The length in bytes of the EEPROM memory array address. Note
3850 that this is NOT the chip address length!
3852 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3853 EEPROM chips that implement "address overflow" are ones
3854 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3855 address and the extra bits end up in the "chip address" bit
3856 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3859 Note that we consider the length of the address field to
3860 still be one byte because the extra address bits are hidden
3861 in the chip address.
3863 - CONFIG_SYS_EEPROM_SIZE:
3864 The size in bytes of the EEPROM device.
3866 - CONFIG_ENV_EEPROM_IS_ON_I2C
3867 define this, if you have I2C and SPI activated, and your
3868 EEPROM, which holds the environment, is on the I2C bus.
3870 - CONFIG_I2C_ENV_EEPROM_BUS
3871 if you have an Environment on an EEPROM reached over
3872 I2C muxes, you can define here, how to reach this
3873 EEPROM. For example:
3875 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3877 EEPROM which holds the environment, is reached over
3878 a pca9547 i2c mux with address 0x70, channel 3.
3880 - CONFIG_ENV_IS_IN_DATAFLASH:
3882 Define this if you have a DataFlash memory device which you
3883 want to use for the environment.
3885 - CONFIG_ENV_OFFSET:
3889 These three #defines specify the offset and size of the
3890 environment area within the total memory of your DataFlash placed
3891 at the specified address.
3893 - CONFIG_ENV_IS_IN_REMOTE:
3895 Define this if you have a remote memory space which you
3896 want to use for the local device's environment.
3901 These two #defines specify the address and size of the
3902 environment area within the remote memory space. The
3903 local device can get the environment from remote memory
3904 space by SRIO or PCIE links.
3906 BE CAREFUL! For some special cases, the local device can not use
3907 "saveenv" command. For example, the local device will get the
3908 environment stored in a remote NOR flash by SRIO or PCIE link,
3909 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3911 - CONFIG_ENV_IS_IN_NAND:
3913 Define this if you have a NAND device which you want to use
3914 for the environment.
3916 - CONFIG_ENV_OFFSET:
3919 These two #defines specify the offset and size of the environment
3920 area within the first NAND device. CONFIG_ENV_OFFSET must be
3921 aligned to an erase block boundary.
3923 - CONFIG_ENV_OFFSET_REDUND (optional):
3925 This setting describes a second storage area of CONFIG_ENV_SIZE
3926 size used to hold a redundant copy of the environment data, so
3927 that there is a valid backup copy in case there is a power failure
3928 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3929 aligned to an erase block boundary.
3931 - CONFIG_ENV_RANGE (optional):
3933 Specifies the length of the region in which the environment
3934 can be written. This should be a multiple of the NAND device's
3935 block size. Specifying a range with more erase blocks than
3936 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3937 the range to be avoided.
3939 - CONFIG_ENV_OFFSET_OOB (optional):
3941 Enables support for dynamically retrieving the offset of the
3942 environment from block zero's out-of-band data. The
3943 "nand env.oob" command can be used to record this offset.
3944 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3945 using CONFIG_ENV_OFFSET_OOB.
3947 - CONFIG_NAND_ENV_DST
3949 Defines address in RAM to which the nand_spl code should copy the
3950 environment. If redundant environment is used, it will be copied to
3951 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3953 - CONFIG_ENV_IS_IN_UBI:
3955 Define this if you have an UBI volume that you want to use for the
3956 environment. This has the benefit of wear-leveling the environment
3957 accesses, which is important on NAND.
3959 - CONFIG_ENV_UBI_PART:
3961 Define this to a string that is the mtd partition containing the UBI.
3963 - CONFIG_ENV_UBI_VOLUME:
3965 Define this to the name of the volume that you want to store the
3968 - CONFIG_ENV_UBI_VOLUME_REDUND:
3970 Define this to the name of another volume to store a second copy of
3971 the environment in. This will enable redundant environments in UBI.
3972 It is assumed that both volumes are in the same MTD partition.
3974 - CONFIG_UBI_SILENCE_MSG
3975 - CONFIG_UBIFS_SILENCE_MSG
3977 You will probably want to define these to avoid a really noisy system
3978 when storing the env in UBI.
3980 - CONFIG_ENV_IS_IN_MMC:
3982 Define this if you have an MMC device which you want to use for the
3985 - CONFIG_SYS_MMC_ENV_DEV:
3987 Specifies which MMC device the environment is stored in.
3989 - CONFIG_SYS_MMC_ENV_PART (optional):
3991 Specifies which MMC partition the environment is stored in. If not
3992 set, defaults to partition 0, the user area. Common values might be
3993 1 (first MMC boot partition), 2 (second MMC boot partition).
3995 - CONFIG_ENV_OFFSET:
3998 These two #defines specify the offset and size of the environment
3999 area within the specified MMC device.
4001 If offset is positive (the usual case), it is treated as relative to
4002 the start of the MMC partition. If offset is negative, it is treated
4003 as relative to the end of the MMC partition. This can be useful if
4004 your board may be fitted with different MMC devices, which have
4005 different sizes for the MMC partitions, and you always want the
4006 environment placed at the very end of the partition, to leave the
4007 maximum possible space before it, to store other data.
4009 These two values are in units of bytes, but must be aligned to an
4010 MMC sector boundary.
4012 - CONFIG_ENV_OFFSET_REDUND (optional):
4014 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4015 hold a redundant copy of the environment data. This provides a
4016 valid backup copy in case the other copy is corrupted, e.g. due
4017 to a power failure during a "saveenv" operation.
4019 This value may also be positive or negative; this is handled in the
4020 same way as CONFIG_ENV_OFFSET.
4022 This value is also in units of bytes, but must also be aligned to
4023 an MMC sector boundary.
4025 - CONFIG_ENV_SIZE_REDUND (optional):
4027 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4028 set. If this value is set, it must be set to the same value as
4031 - CONFIG_SYS_SPI_INIT_OFFSET
4033 Defines offset to the initial SPI buffer area in DPRAM. The
4034 area is used at an early stage (ROM part) if the environment
4035 is configured to reside in the SPI EEPROM: We need a 520 byte
4036 scratch DPRAM area. It is used between the two initialization
4037 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4038 to be a good choice since it makes it far enough from the
4039 start of the data area as well as from the stack pointer.
4041 Please note that the environment is read-only until the monitor
4042 has been relocated to RAM and a RAM copy of the environment has been
4043 created; also, when using EEPROM you will have to use getenv_f()
4044 until then to read environment variables.
4046 The environment is protected by a CRC32 checksum. Before the monitor
4047 is relocated into RAM, as a result of a bad CRC you will be working
4048 with the compiled-in default environment - *silently*!!! [This is
4049 necessary, because the first environment variable we need is the
4050 "baudrate" setting for the console - if we have a bad CRC, we don't
4051 have any device yet where we could complain.]
4053 Note: once the monitor has been relocated, then it will complain if
4054 the default environment is used; a new CRC is computed as soon as you
4055 use the "saveenv" command to store a valid environment.
4057 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4058 Echo the inverted Ethernet link state to the fault LED.
4060 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4061 also needs to be defined.
4063 - CONFIG_SYS_FAULT_MII_ADDR:
4064 MII address of the PHY to check for the Ethernet link state.
4066 - CONFIG_NS16550_MIN_FUNCTIONS:
4067 Define this if you desire to only have use of the NS16550_init
4068 and NS16550_putc functions for the serial driver located at
4069 drivers/serial/ns16550.c. This option is useful for saving
4070 space for already greatly restricted images, including but not
4071 limited to NAND_SPL configurations.
4073 - CONFIG_DISPLAY_BOARDINFO
4074 Display information about the board that U-Boot is running on
4075 when U-Boot starts up. The board function checkboard() is called
4078 - CONFIG_DISPLAY_BOARDINFO_LATE
4079 Similar to the previous option, but display this information
4080 later, once stdio is running and output goes to the LCD, if
4083 Low Level (hardware related) configuration options:
4084 ---------------------------------------------------
4086 - CONFIG_SYS_CACHELINE_SIZE:
4087 Cache Line Size of the CPU.
4089 - CONFIG_SYS_DEFAULT_IMMR:
4090 Default address of the IMMR after system reset.
4092 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4093 and RPXsuper) to be able to adjust the position of
4094 the IMMR register after a reset.
4096 - CONFIG_SYS_CCSRBAR_DEFAULT:
4097 Default (power-on reset) physical address of CCSR on Freescale
4100 - CONFIG_SYS_CCSRBAR:
4101 Virtual address of CCSR. On a 32-bit build, this is typically
4102 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4104 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4105 for cross-platform code that uses that macro instead.
4107 - CONFIG_SYS_CCSRBAR_PHYS:
4108 Physical address of CCSR. CCSR can be relocated to a new
4109 physical address, if desired. In this case, this macro should
4110 be set to that address. Otherwise, it should be set to the
4111 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4112 is typically relocated on 36-bit builds. It is recommended
4113 that this macro be defined via the _HIGH and _LOW macros:
4115 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4116 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4118 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4119 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4120 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4121 used in assembly code, so it must not contain typecasts or
4122 integer size suffixes (e.g. "ULL").
4124 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4125 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4126 used in assembly code, so it must not contain typecasts or
4127 integer size suffixes (e.g. "ULL").
4129 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4130 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4131 forced to a value that ensures that CCSR is not relocated.
4133 - Floppy Disk Support:
4134 CONFIG_SYS_FDC_DRIVE_NUMBER
4136 the default drive number (default value 0)
4138 CONFIG_SYS_ISA_IO_STRIDE
4140 defines the spacing between FDC chipset registers
4143 CONFIG_SYS_ISA_IO_OFFSET
4145 defines the offset of register from address. It
4146 depends on which part of the data bus is connected to
4147 the FDC chipset. (default value 0)
4149 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4150 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4153 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4154 fdc_hw_init() is called at the beginning of the FDC
4155 setup. fdc_hw_init() must be provided by the board
4156 source code. It is used to make hardware dependant
4160 Most IDE controllers were designed to be connected with PCI
4161 interface. Only few of them were designed for AHB interface.
4162 When software is doing ATA command and data transfer to
4163 IDE devices through IDE-AHB controller, some additional
4164 registers accessing to these kind of IDE-AHB controller
4167 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4168 DO NOT CHANGE unless you know exactly what you're
4169 doing! (11-4) [MPC8xx/82xx systems only]
4171 - CONFIG_SYS_INIT_RAM_ADDR:
4173 Start address of memory area that can be used for
4174 initial data and stack; please note that this must be
4175 writable memory that is working WITHOUT special
4176 initialization, i. e. you CANNOT use normal RAM which
4177 will become available only after programming the
4178 memory controller and running certain initialization
4181 U-Boot uses the following memory types:
4182 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4183 - MPC824X: data cache
4184 - PPC4xx: data cache
4186 - CONFIG_SYS_GBL_DATA_OFFSET:
4188 Offset of the initial data structure in the memory
4189 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4190 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4191 data is located at the end of the available space
4192 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4193 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4194 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4195 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4198 On the MPC824X (or other systems that use the data
4199 cache for initial memory) the address chosen for
4200 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4201 point to an otherwise UNUSED address space between
4202 the top of RAM and the start of the PCI space.
4204 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4206 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4208 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4210 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4212 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4214 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4216 - CONFIG_SYS_OR_TIMING_SDRAM:
4219 - CONFIG_SYS_MAMR_PTA:
4220 periodic timer for refresh
4222 - CONFIG_SYS_DER: Debug Event Register (37-47)
4224 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4225 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4226 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4227 CONFIG_SYS_BR1_PRELIM:
4228 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4230 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4231 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4232 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4233 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4235 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4236 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4237 Machine Mode Register and Memory Periodic Timer
4238 Prescaler definitions (SDRAM timing)
4240 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4241 enable I2C microcode relocation patch (MPC8xx);
4242 define relocation offset in DPRAM [DSP2]
4244 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4245 enable SMC microcode relocation patch (MPC8xx);
4246 define relocation offset in DPRAM [SMC1]
4248 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4249 enable SPI microcode relocation patch (MPC8xx);
4250 define relocation offset in DPRAM [SCC4]
4252 - CONFIG_SYS_USE_OSCCLK:
4253 Use OSCM clock mode on MBX8xx board. Be careful,
4254 wrong setting might damage your board. Read
4255 doc/README.MBX before setting this variable!
4257 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4258 Offset of the bootmode word in DPRAM used by post
4259 (Power On Self Tests). This definition overrides
4260 #define'd default value in commproc.h resp.
4263 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4264 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4265 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4266 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4267 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4268 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4269 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4270 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4271 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4273 - CONFIG_PCI_DISABLE_PCIE:
4274 Disable PCI-Express on systems where it is supported but not
4277 - CONFIG_PCI_ENUM_ONLY
4278 Only scan through and get the devices on the busses.
4279 Don't do any setup work, presumably because someone or
4280 something has already done it, and we don't need to do it
4281 a second time. Useful for platforms that are pre-booted
4282 by coreboot or similar.
4284 - CONFIG_PCI_INDIRECT_BRIDGE:
4285 Enable support for indirect PCI bridges.
4288 Chip has SRIO or not
4291 Board has SRIO 1 port available
4294 Board has SRIO 2 port available
4296 - CONFIG_SRIO_PCIE_BOOT_MASTER
4297 Board can support master function for Boot from SRIO and PCIE
4299 - CONFIG_SYS_SRIOn_MEM_VIRT:
4300 Virtual Address of SRIO port 'n' memory region
4302 - CONFIG_SYS_SRIOn_MEM_PHYS:
4303 Physical Address of SRIO port 'n' memory region
4305 - CONFIG_SYS_SRIOn_MEM_SIZE:
4306 Size of SRIO port 'n' memory region
4308 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4309 Defined to tell the NAND controller that the NAND chip is using
4311 Not all NAND drivers use this symbol.
4312 Example of drivers that use it:
4313 - drivers/mtd/nand/ndfc.c
4314 - drivers/mtd/nand/mxc_nand.c
4316 - CONFIG_SYS_NDFC_EBC0_CFG
4317 Sets the EBC0_CFG register for the NDFC. If not defined
4318 a default value will be used.
4321 Get DDR timing information from an I2C EEPROM. Common
4322 with pluggable memory modules such as SODIMMs
4325 I2C address of the SPD EEPROM
4327 - CONFIG_SYS_SPD_BUS_NUM
4328 If SPD EEPROM is on an I2C bus other than the first
4329 one, specify here. Note that the value must resolve
4330 to something your driver can deal with.
4332 - CONFIG_SYS_DDR_RAW_TIMING
4333 Get DDR timing information from other than SPD. Common with
4334 soldered DDR chips onboard without SPD. DDR raw timing
4335 parameters are extracted from datasheet and hard-coded into
4336 header files or board specific files.
4338 - CONFIG_FSL_DDR_INTERACTIVE
4339 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4341 - CONFIG_SYS_83XX_DDR_USES_CS0
4342 Only for 83xx systems. If specified, then DDR should
4343 be configured using CS0 and CS1 instead of CS2 and CS3.
4345 - CONFIG_ETHER_ON_FEC[12]
4346 Define to enable FEC[12] on a 8xx series processor.
4348 - CONFIG_FEC[12]_PHY
4349 Define to the hardcoded PHY address which corresponds
4350 to the given FEC; i. e.
4351 #define CONFIG_FEC1_PHY 4
4352 means that the PHY with address 4 is connected to FEC1
4354 When set to -1, means to probe for first available.
4356 - CONFIG_FEC[12]_PHY_NORXERR
4357 The PHY does not have a RXERR line (RMII only).
4358 (so program the FEC to ignore it).
4361 Enable RMII mode for all FECs.
4362 Note that this is a global option, we can't
4363 have one FEC in standard MII mode and another in RMII mode.
4365 - CONFIG_CRC32_VERIFY
4366 Add a verify option to the crc32 command.
4369 => crc32 -v <address> <count> <crc32>
4371 Where address/count indicate a memory area
4372 and crc32 is the correct crc32 which the
4376 Add the "loopw" memory command. This only takes effect if
4377 the memory commands are activated globally (CONFIG_CMD_MEM).
4380 Add the "mdc" and "mwc" memory commands. These are cyclic
4385 This command will print 4 bytes (10,11,12,13) each 500 ms.
4387 => mwc.l 100 12345678 10
4388 This command will write 12345678 to address 100 all 10 ms.
4390 This only takes effect if the memory commands are activated
4391 globally (CONFIG_CMD_MEM).
4393 - CONFIG_SKIP_LOWLEVEL_INIT
4394 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4395 low level initializations (like setting up the memory
4396 controller) are omitted and/or U-Boot does not
4397 relocate itself into RAM.
4399 Normally this variable MUST NOT be defined. The only
4400 exception is when U-Boot is loaded (to RAM) by some
4401 other boot loader or by a debugger which performs
4402 these initializations itself.
4405 Modifies the behaviour of start.S when compiling a loader
4406 that is executed before the actual U-Boot. E.g. when
4407 compiling a NAND SPL.
4410 Modifies the behaviour of start.S when compiling a loader
4411 that is executed after the SPL and before the actual U-Boot.
4412 It is loaded by the SPL.
4414 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4415 Only for 85xx systems. If this variable is specified, the section
4416 .resetvec is not kept and the section .bootpg is placed in the
4417 previous 4k of the .text section.
4419 - CONFIG_ARCH_MAP_SYSMEM
4420 Generally U-Boot (and in particular the md command) uses
4421 effective address. It is therefore not necessary to regard
4422 U-Boot address as virtual addresses that need to be translated
4423 to physical addresses. However, sandbox requires this, since
4424 it maintains its own little RAM buffer which contains all
4425 addressable memory. This option causes some memory accesses
4426 to be mapped through map_sysmem() / unmap_sysmem().
4428 - CONFIG_USE_ARCH_MEMCPY
4429 CONFIG_USE_ARCH_MEMSET
4430 If these options are used a optimized version of memcpy/memset will
4431 be used if available. These functions may be faster under some
4432 conditions but may increase the binary size.
4434 - CONFIG_X86_RESET_VECTOR
4435 If defined, the x86 reset vector code is included. This is not
4436 needed when U-Boot is running from Coreboot.
4439 Defines the MPU clock speed (in MHz).
4441 NOTE : currently only supported on AM335x platforms.
4443 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4444 Enables the RTC32K OSC on AM33xx based plattforms
4446 Freescale QE/FMAN Firmware Support:
4447 -----------------------------------
4449 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4450 loading of "firmware", which is encoded in the QE firmware binary format.
4451 This firmware often needs to be loaded during U-Boot booting, so macros
4452 are used to identify the storage device (NOR flash, SPI, etc) and the address
4455 - CONFIG_SYS_QE_FMAN_FW_ADDR
4456 The address in the storage device where the firmware is located. The
4457 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4460 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4461 The maximum possible size of the firmware. The firmware binary format
4462 has a field that specifies the actual size of the firmware, but it
4463 might not be possible to read any part of the firmware unless some
4464 local storage is allocated to hold the entire firmware first.
4466 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4467 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4468 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4469 virtual address in NOR flash.
4471 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4472 Specifies that QE/FMAN firmware is located in NAND flash.
4473 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4475 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4476 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4477 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4479 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4480 Specifies that QE/FMAN firmware is located on the primary SPI
4481 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4483 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4484 Specifies that QE/FMAN firmware is located in the remote (master)
4485 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4486 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4487 window->master inbound window->master LAW->the ucode address in
4488 master's memory space.
4490 Building the Software:
4491 ======================
4493 Building U-Boot has been tested in several native build environments
4494 and in many different cross environments. Of course we cannot support
4495 all possibly existing versions of cross development tools in all
4496 (potentially obsolete) versions. In case of tool chain problems we
4497 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4498 which is extensively used to build and test U-Boot.
4500 If you are not using a native environment, it is assumed that you
4501 have GNU cross compiling tools available in your path. In this case,
4502 you must set the environment variable CROSS_COMPILE in your shell.
4503 Note that no changes to the Makefile or any other source files are
4504 necessary. For example using the ELDK on a 4xx CPU, please enter:
4506 $ CROSS_COMPILE=ppc_4xx-
4507 $ export CROSS_COMPILE
4509 Note: If you wish to generate Windows versions of the utilities in
4510 the tools directory you can use the MinGW toolchain
4511 (http://www.mingw.org). Set your HOST tools to the MinGW
4512 toolchain and execute 'make tools'. For example:
4514 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4516 Binaries such as tools/mkimage.exe will be created which can
4517 be executed on computers running Windows.
4519 U-Boot is intended to be simple to build. After installing the
4520 sources you must configure U-Boot for one specific board type. This
4525 where "NAME_config" is the name of one of the existing configu-
4526 rations; see boards.cfg for supported names.
4528 Note: for some board special configuration names may exist; check if
4529 additional information is available from the board vendor; for
4530 instance, the TQM823L systems are available without (standard)
4531 or with LCD support. You can select such additional "features"
4532 when choosing the configuration, i. e.
4535 - will configure for a plain TQM823L, i. e. no LCD support
4537 make TQM823L_LCD_config
4538 - will configure for a TQM823L with U-Boot console on LCD
4543 Finally, type "make all", and you should get some working U-Boot
4544 images ready for download to / installation on your system:
4546 - "u-boot.bin" is a raw binary image
4547 - "u-boot" is an image in ELF binary format
4548 - "u-boot.srec" is in Motorola S-Record format
4550 By default the build is performed locally and the objects are saved
4551 in the source directory. One of the two methods can be used to change
4552 this behavior and build U-Boot to some external directory:
4554 1. Add O= to the make command line invocations:
4556 make O=/tmp/build distclean
4557 make O=/tmp/build NAME_config
4558 make O=/tmp/build all
4560 2. Set environment variable BUILD_DIR to point to the desired location:
4562 export BUILD_DIR=/tmp/build
4567 Note that the command line "O=" setting overrides the BUILD_DIR environment
4571 Please be aware that the Makefiles assume you are using GNU make, so
4572 for instance on NetBSD you might need to use "gmake" instead of
4576 If the system board that you have is not listed, then you will need
4577 to port U-Boot to your hardware platform. To do this, follow these
4580 1. Add a new configuration option for your board to the toplevel
4581 "boards.cfg" file, using the existing entries as examples.
4582 Follow the instructions there to keep the boards in order.
4583 2. Create a new directory to hold your board specific code. Add any
4584 files you need. In your board directory, you will need at least
4585 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4586 3. Create a new configuration file "include/configs/<board>.h" for
4588 3. If you're porting U-Boot to a new CPU, then also create a new
4589 directory to hold your CPU specific code. Add any files you need.
4590 4. Run "make <board>_config" with your new name.
4591 5. Type "make", and you should get a working "u-boot.srec" file
4592 to be installed on your target system.
4593 6. Debug and solve any problems that might arise.
4594 [Of course, this last step is much harder than it sounds.]
4597 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4598 ==============================================================
4600 If you have modified U-Boot sources (for instance added a new board
4601 or support for new devices, a new CPU, etc.) you are expected to
4602 provide feedback to the other developers. The feedback normally takes
4603 the form of a "patch", i. e. a context diff against a certain (latest
4604 official or latest in the git repository) version of U-Boot sources.
4606 But before you submit such a patch, please verify that your modifi-
4607 cation did not break existing code. At least make sure that *ALL* of
4608 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4609 just run the "MAKEALL" script, which will configure and build U-Boot
4610 for ALL supported system. Be warned, this will take a while. You can
4611 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4612 environment variable to the script, i. e. to use the ELDK cross tools
4615 CROSS_COMPILE=ppc_8xx- MAKEALL
4617 or to build on a native PowerPC system you can type
4619 CROSS_COMPILE=' ' MAKEALL
4621 When using the MAKEALL script, the default behaviour is to build
4622 U-Boot in the source directory. This location can be changed by
4623 setting the BUILD_DIR environment variable. Also, for each target
4624 built, the MAKEALL script saves two log files (<target>.ERR and
4625 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4626 location can be changed by setting the MAKEALL_LOGDIR environment
4627 variable. For example:
4629 export BUILD_DIR=/tmp/build
4630 export MAKEALL_LOGDIR=/tmp/log
4631 CROSS_COMPILE=ppc_8xx- MAKEALL
4633 With the above settings build objects are saved in the /tmp/build,
4634 log files are saved in the /tmp/log and the source tree remains clean
4635 during the whole build process.
4638 See also "U-Boot Porting Guide" below.
4641 Monitor Commands - Overview:
4642 ============================
4644 go - start application at address 'addr'
4645 run - run commands in an environment variable
4646 bootm - boot application image from memory
4647 bootp - boot image via network using BootP/TFTP protocol
4648 bootz - boot zImage from memory
4649 tftpboot- boot image via network using TFTP protocol
4650 and env variables "ipaddr" and "serverip"
4651 (and eventually "gatewayip")
4652 tftpput - upload a file via network using TFTP protocol
4653 rarpboot- boot image via network using RARP/TFTP protocol
4654 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4655 loads - load S-Record file over serial line
4656 loadb - load binary file over serial line (kermit mode)
4658 mm - memory modify (auto-incrementing)
4659 nm - memory modify (constant address)
4660 mw - memory write (fill)
4662 cmp - memory compare
4663 crc32 - checksum calculation
4664 i2c - I2C sub-system
4665 sspi - SPI utility commands
4666 base - print or set address offset
4667 printenv- print environment variables
4668 setenv - set environment variables
4669 saveenv - save environment variables to persistent storage
4670 protect - enable or disable FLASH write protection
4671 erase - erase FLASH memory
4672 flinfo - print FLASH memory information
4673 nand - NAND memory operations (see doc/README.nand)
4674 bdinfo - print Board Info structure
4675 iminfo - print header information for application image
4676 coninfo - print console devices and informations
4677 ide - IDE sub-system
4678 loop - infinite loop on address range
4679 loopw - infinite write loop on address range
4680 mtest - simple RAM test
4681 icache - enable or disable instruction cache
4682 dcache - enable or disable data cache
4683 reset - Perform RESET of the CPU
4684 echo - echo args to console
4685 version - print monitor version
4686 help - print online help
4687 ? - alias for 'help'
4690 Monitor Commands - Detailed Description:
4691 ========================================
4695 For now: just type "help <command>".
4698 Environment Variables:
4699 ======================
4701 U-Boot supports user configuration using Environment Variables which
4702 can be made persistent by saving to Flash memory.
4704 Environment Variables are set using "setenv", printed using
4705 "printenv", and saved to Flash using "saveenv". Using "setenv"
4706 without a value can be used to delete a variable from the
4707 environment. As long as you don't save the environment you are
4708 working with an in-memory copy. In case the Flash area containing the
4709 environment is erased by accident, a default environment is provided.
4711 Some configuration options can be set using Environment Variables.
4713 List of environment variables (most likely not complete):
4715 baudrate - see CONFIG_BAUDRATE
4717 bootdelay - see CONFIG_BOOTDELAY
4719 bootcmd - see CONFIG_BOOTCOMMAND
4721 bootargs - Boot arguments when booting an RTOS image
4723 bootfile - Name of the image to load with TFTP
4725 bootm_low - Memory range available for image processing in the bootm
4726 command can be restricted. This variable is given as
4727 a hexadecimal number and defines lowest address allowed
4728 for use by the bootm command. See also "bootm_size"
4729 environment variable. Address defined by "bootm_low" is
4730 also the base of the initial memory mapping for the Linux
4731 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4734 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4735 This variable is given as a hexadecimal number and it
4736 defines the size of the memory region starting at base
4737 address bootm_low that is accessible by the Linux kernel
4738 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4739 as the default value if it is defined, and bootm_size is
4742 bootm_size - Memory range available for image processing in the bootm
4743 command can be restricted. This variable is given as
4744 a hexadecimal number and defines the size of the region
4745 allowed for use by the bootm command. See also "bootm_low"
4746 environment variable.
4748 updatefile - Location of the software update file on a TFTP server, used
4749 by the automatic software update feature. Please refer to
4750 documentation in doc/README.update for more details.
4752 autoload - if set to "no" (any string beginning with 'n'),
4753 "bootp" will just load perform a lookup of the
4754 configuration from the BOOTP server, but not try to
4755 load any image using TFTP
4757 autostart - if set to "yes", an image loaded using the "bootp",
4758 "rarpboot", "tftpboot" or "diskboot" commands will
4759 be automatically started (by internally calling
4762 If set to "no", a standalone image passed to the
4763 "bootm" command will be copied to the load address
4764 (and eventually uncompressed), but NOT be started.
4765 This can be used to load and uncompress arbitrary
4768 fdt_high - if set this restricts the maximum address that the
4769 flattened device tree will be copied into upon boot.
4770 For example, if you have a system with 1 GB memory
4771 at physical address 0x10000000, while Linux kernel
4772 only recognizes the first 704 MB as low memory, you
4773 may need to set fdt_high as 0x3C000000 to have the
4774 device tree blob be copied to the maximum address
4775 of the 704 MB low memory, so that Linux kernel can
4776 access it during the boot procedure.
4778 If this is set to the special value 0xFFFFFFFF then
4779 the fdt will not be copied at all on boot. For this
4780 to work it must reside in writable memory, have
4781 sufficient padding on the end of it for u-boot to
4782 add the information it needs into it, and the memory
4783 must be accessible by the kernel.
4785 fdtcontroladdr- if set this is the address of the control flattened
4786 device tree used by U-Boot when CONFIG_OF_CONTROL is
4789 i2cfast - (PPC405GP|PPC405EP only)
4790 if set to 'y' configures Linux I2C driver for fast
4791 mode (400kHZ). This environment variable is used in
4792 initialization code. So, for changes to be effective
4793 it must be saved and board must be reset.
4795 initrd_high - restrict positioning of initrd images:
4796 If this variable is not set, initrd images will be
4797 copied to the highest possible address in RAM; this
4798 is usually what you want since it allows for
4799 maximum initrd size. If for some reason you want to
4800 make sure that the initrd image is loaded below the
4801 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4802 variable to a value of "no" or "off" or "0".
4803 Alternatively, you can set it to a maximum upper
4804 address to use (U-Boot will still check that it
4805 does not overwrite the U-Boot stack and data).
4807 For instance, when you have a system with 16 MB
4808 RAM, and want to reserve 4 MB from use by Linux,
4809 you can do this by adding "mem=12M" to the value of
4810 the "bootargs" variable. However, now you must make
4811 sure that the initrd image is placed in the first
4812 12 MB as well - this can be done with
4814 setenv initrd_high 00c00000
4816 If you set initrd_high to 0xFFFFFFFF, this is an
4817 indication to U-Boot that all addresses are legal
4818 for the Linux kernel, including addresses in flash
4819 memory. In this case U-Boot will NOT COPY the
4820 ramdisk at all. This may be useful to reduce the
4821 boot time on your system, but requires that this
4822 feature is supported by your Linux kernel.
4824 ipaddr - IP address; needed for tftpboot command
4826 loadaddr - Default load address for commands like "bootp",
4827 "rarpboot", "tftpboot", "loadb" or "diskboot"
4829 loads_echo - see CONFIG_LOADS_ECHO
4831 serverip - TFTP server IP address; needed for tftpboot command
4833 bootretry - see CONFIG_BOOT_RETRY_TIME
4835 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4837 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4839 ethprime - controls which interface is used first.
4841 ethact - controls which interface is currently active.
4842 For example you can do the following
4844 => setenv ethact FEC
4845 => ping 192.168.0.1 # traffic sent on FEC
4846 => setenv ethact SCC
4847 => ping 10.0.0.1 # traffic sent on SCC
4849 ethrotate - When set to "no" U-Boot does not go through all
4850 available network interfaces.
4851 It just stays at the currently selected interface.
4853 netretry - When set to "no" each network operation will
4854 either succeed or fail without retrying.
4855 When set to "once" the network operation will
4856 fail when all the available network interfaces
4857 are tried once without success.
4858 Useful on scripts which control the retry operation
4861 npe_ucode - set load address for the NPE microcode
4863 silent_linux - If set then linux will be told to boot silently, by
4864 changing the console to be empty. If "yes" it will be
4865 made silent. If "no" it will not be made silent. If
4866 unset, then it will be made silent if the U-Boot console
4869 tftpsrcport - If this is set, the value is used for TFTP's
4872 tftpdstport - If this is set, the value is used for TFTP's UDP
4873 destination port instead of the Well Know Port 69.
4875 tftpblocksize - Block size to use for TFTP transfers; if not set,
4876 we use the TFTP server's default block size
4878 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4879 seconds, minimum value is 1000 = 1 second). Defines
4880 when a packet is considered to be lost so it has to
4881 be retransmitted. The default is 5000 = 5 seconds.
4882 Lowering this value may make downloads succeed
4883 faster in networks with high packet loss rates or
4884 with unreliable TFTP servers.
4886 vlan - When set to a value < 4095 the traffic over
4887 Ethernet is encapsulated/received over 802.1q
4890 The following image location variables contain the location of images
4891 used in booting. The "Image" column gives the role of the image and is
4892 not an environment variable name. The other columns are environment
4893 variable names. "File Name" gives the name of the file on a TFTP
4894 server, "RAM Address" gives the location in RAM the image will be
4895 loaded to, and "Flash Location" gives the image's address in NOR
4896 flash or offset in NAND flash.
4898 *Note* - these variables don't have to be defined for all boards, some
4899 boards currenlty use other variables for these purposes, and some
4900 boards use these variables for other purposes.
4902 Image File Name RAM Address Flash Location
4903 ----- --------- ----------- --------------
4904 u-boot u-boot u-boot_addr_r u-boot_addr
4905 Linux kernel bootfile kernel_addr_r kernel_addr
4906 device tree blob fdtfile fdt_addr_r fdt_addr
4907 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4909 The following environment variables may be used and automatically
4910 updated by the network boot commands ("bootp" and "rarpboot"),
4911 depending the information provided by your boot server:
4913 bootfile - see above
4914 dnsip - IP address of your Domain Name Server
4915 dnsip2 - IP address of your secondary Domain Name Server
4916 gatewayip - IP address of the Gateway (Router) to use
4917 hostname - Target hostname
4919 netmask - Subnet Mask
4920 rootpath - Pathname of the root filesystem on the NFS server
4921 serverip - see above
4924 There are two special Environment Variables:
4926 serial# - contains hardware identification information such
4927 as type string and/or serial number
4928 ethaddr - Ethernet address
4930 These variables can be set only once (usually during manufacturing of
4931 the board). U-Boot refuses to delete or overwrite these variables
4932 once they have been set once.
4935 Further special Environment Variables:
4937 ver - Contains the U-Boot version string as printed
4938 with the "version" command. This variable is
4939 readonly (see CONFIG_VERSION_VARIABLE).
4942 Please note that changes to some configuration parameters may take
4943 only effect after the next boot (yes, that's just like Windoze :-).
4946 Callback functions for environment variables:
4947 ---------------------------------------------
4949 For some environment variables, the behavior of u-boot needs to change
4950 when their values are changed. This functionailty allows functions to
4951 be associated with arbitrary variables. On creation, overwrite, or
4952 deletion, the callback will provide the opportunity for some side
4953 effect to happen or for the change to be rejected.
4955 The callbacks are named and associated with a function using the
4956 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4958 These callbacks are associated with variables in one of two ways. The
4959 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4960 in the board configuration to a string that defines a list of
4961 associations. The list must be in the following format:
4963 entry = variable_name[:callback_name]
4966 If the callback name is not specified, then the callback is deleted.
4967 Spaces are also allowed anywhere in the list.
4969 Callbacks can also be associated by defining the ".callbacks" variable
4970 with the same list format above. Any association in ".callbacks" will
4971 override any association in the static list. You can define
4972 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4973 ".callbacks" envirnoment variable in the default or embedded environment.
4976 Command Line Parsing:
4977 =====================
4979 There are two different command line parsers available with U-Boot:
4980 the old "simple" one, and the much more powerful "hush" shell:
4982 Old, simple command line parser:
4983 --------------------------------
4985 - supports environment variables (through setenv / saveenv commands)
4986 - several commands on one line, separated by ';'
4987 - variable substitution using "... ${name} ..." syntax
4988 - special characters ('$', ';') can be escaped by prefixing with '\',
4990 setenv bootcmd bootm \${address}
4991 - You can also escape text by enclosing in single apostrophes, for example:
4992 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4997 - similar to Bourne shell, with control structures like
4998 if...then...else...fi, for...do...done; while...do...done,
4999 until...do...done, ...
5000 - supports environment ("global") variables (through setenv / saveenv
5001 commands) and local shell variables (through standard shell syntax
5002 "name=value"); only environment variables can be used with "run"
5008 (1) If a command line (or an environment variable executed by a "run"
5009 command) contains several commands separated by semicolon, and
5010 one of these commands fails, then the remaining commands will be
5013 (2) If you execute several variables with one call to run (i. e.
5014 calling run with a list of variables as arguments), any failing
5015 command will cause "run" to terminate, i. e. the remaining
5016 variables are not executed.
5018 Note for Redundant Ethernet Interfaces:
5019 =======================================
5021 Some boards come with redundant Ethernet interfaces; U-Boot supports
5022 such configurations and is capable of automatic selection of a
5023 "working" interface when needed. MAC assignment works as follows:
5025 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5026 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5027 "eth1addr" (=>eth1), "eth2addr", ...
5029 If the network interface stores some valid MAC address (for instance
5030 in SROM), this is used as default address if there is NO correspon-
5031 ding setting in the environment; if the corresponding environment
5032 variable is set, this overrides the settings in the card; that means:
5034 o If the SROM has a valid MAC address, and there is no address in the
5035 environment, the SROM's address is used.
5037 o If there is no valid address in the SROM, and a definition in the
5038 environment exists, then the value from the environment variable is
5041 o If both the SROM and the environment contain a MAC address, and
5042 both addresses are the same, this MAC address is used.
5044 o If both the SROM and the environment contain a MAC address, and the
5045 addresses differ, the value from the environment is used and a
5048 o If neither SROM nor the environment contain a MAC address, an error
5051 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5052 will be programmed into hardware as part of the initialization process. This
5053 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5054 The naming convention is as follows:
5055 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5060 U-Boot is capable of booting (and performing other auxiliary operations on)
5061 images in two formats:
5063 New uImage format (FIT)
5064 -----------------------
5066 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5067 to Flattened Device Tree). It allows the use of images with multiple
5068 components (several kernels, ramdisks, etc.), with contents protected by
5069 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5075 Old image format is based on binary files which can be basically anything,
5076 preceded by a special header; see the definitions in include/image.h for
5077 details; basically, the header defines the following image properties:
5079 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5080 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5081 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5082 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5084 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5085 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5086 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5087 * Compression Type (uncompressed, gzip, bzip2)
5093 The header is marked by a special Magic Number, and both the header
5094 and the data portions of the image are secured against corruption by
5101 Although U-Boot should support any OS or standalone application
5102 easily, the main focus has always been on Linux during the design of
5105 U-Boot includes many features that so far have been part of some
5106 special "boot loader" code within the Linux kernel. Also, any
5107 "initrd" images to be used are no longer part of one big Linux image;
5108 instead, kernel and "initrd" are separate images. This implementation
5109 serves several purposes:
5111 - the same features can be used for other OS or standalone
5112 applications (for instance: using compressed images to reduce the
5113 Flash memory footprint)
5115 - it becomes much easier to port new Linux kernel versions because
5116 lots of low-level, hardware dependent stuff are done by U-Boot
5118 - the same Linux kernel image can now be used with different "initrd"
5119 images; of course this also means that different kernel images can
5120 be run with the same "initrd". This makes testing easier (you don't
5121 have to build a new "zImage.initrd" Linux image when you just
5122 change a file in your "initrd"). Also, a field-upgrade of the
5123 software is easier now.
5129 Porting Linux to U-Boot based systems:
5130 ---------------------------------------
5132 U-Boot cannot save you from doing all the necessary modifications to
5133 configure the Linux device drivers for use with your target hardware
5134 (no, we don't intend to provide a full virtual machine interface to
5137 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5139 Just make sure your machine specific header file (for instance
5140 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5141 Information structure as we define in include/asm-<arch>/u-boot.h,
5142 and make sure that your definition of IMAP_ADDR uses the same value
5143 as your U-Boot configuration in CONFIG_SYS_IMMR.
5146 Configuring the Linux kernel:
5147 -----------------------------
5149 No specific requirements for U-Boot. Make sure you have some root
5150 device (initial ramdisk, NFS) for your target system.
5153 Building a Linux Image:
5154 -----------------------
5156 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5157 not used. If you use recent kernel source, a new build target
5158 "uImage" will exist which automatically builds an image usable by
5159 U-Boot. Most older kernels also have support for a "pImage" target,
5160 which was introduced for our predecessor project PPCBoot and uses a
5161 100% compatible format.
5170 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5171 encapsulate a compressed Linux kernel image with header information,
5172 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5174 * build a standard "vmlinux" kernel image (in ELF binary format):
5176 * convert the kernel into a raw binary image:
5178 ${CROSS_COMPILE}-objcopy -O binary \
5179 -R .note -R .comment \
5180 -S vmlinux linux.bin
5182 * compress the binary image:
5186 * package compressed binary image for U-Boot:
5188 mkimage -A ppc -O linux -T kernel -C gzip \
5189 -a 0 -e 0 -n "Linux Kernel Image" \
5190 -d linux.bin.gz uImage
5193 The "mkimage" tool can also be used to create ramdisk images for use
5194 with U-Boot, either separated from the Linux kernel image, or
5195 combined into one file. "mkimage" encapsulates the images with a 64
5196 byte header containing information about target architecture,
5197 operating system, image type, compression method, entry points, time
5198 stamp, CRC32 checksums, etc.
5200 "mkimage" can be called in two ways: to verify existing images and
5201 print the header information, or to build new images.
5203 In the first form (with "-l" option) mkimage lists the information
5204 contained in the header of an existing U-Boot image; this includes
5205 checksum verification:
5207 tools/mkimage -l image
5208 -l ==> list image header information
5210 The second form (with "-d" option) is used to build a U-Boot image
5211 from a "data file" which is used as image payload:
5213 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5214 -n name -d data_file image
5215 -A ==> set architecture to 'arch'
5216 -O ==> set operating system to 'os'
5217 -T ==> set image type to 'type'
5218 -C ==> set compression type 'comp'
5219 -a ==> set load address to 'addr' (hex)
5220 -e ==> set entry point to 'ep' (hex)
5221 -n ==> set image name to 'name'
5222 -d ==> use image data from 'datafile'
5224 Right now, all Linux kernels for PowerPC systems use the same load
5225 address (0x00000000), but the entry point address depends on the
5228 - 2.2.x kernels have the entry point at 0x0000000C,
5229 - 2.3.x and later kernels have the entry point at 0x00000000.
5231 So a typical call to build a U-Boot image would read:
5233 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5234 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5235 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5236 > examples/uImage.TQM850L
5237 Image Name: 2.4.4 kernel for TQM850L
5238 Created: Wed Jul 19 02:34:59 2000
5239 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5240 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5241 Load Address: 0x00000000
5242 Entry Point: 0x00000000
5244 To verify the contents of the image (or check for corruption):
5246 -> tools/mkimage -l examples/uImage.TQM850L
5247 Image Name: 2.4.4 kernel for TQM850L
5248 Created: Wed Jul 19 02:34:59 2000
5249 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5250 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5251 Load Address: 0x00000000
5252 Entry Point: 0x00000000
5254 NOTE: for embedded systems where boot time is critical you can trade
5255 speed for memory and install an UNCOMPRESSED image instead: this
5256 needs more space in Flash, but boots much faster since it does not
5257 need to be uncompressed:
5259 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5260 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5261 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5262 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5263 > examples/uImage.TQM850L-uncompressed
5264 Image Name: 2.4.4 kernel for TQM850L
5265 Created: Wed Jul 19 02:34:59 2000
5266 Image Type: PowerPC Linux Kernel Image (uncompressed)
5267 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5268 Load Address: 0x00000000
5269 Entry Point: 0x00000000
5272 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5273 when your kernel is intended to use an initial ramdisk:
5275 -> tools/mkimage -n 'Simple Ramdisk Image' \
5276 > -A ppc -O linux -T ramdisk -C gzip \
5277 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5278 Image Name: Simple Ramdisk Image
5279 Created: Wed Jan 12 14:01:50 2000
5280 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5281 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5282 Load Address: 0x00000000
5283 Entry Point: 0x00000000
5285 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5286 option performs the converse operation of the mkimage's second form (the "-d"
5287 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5290 tools/dumpimage -i image -p position data_file
5291 -i ==> extract from the 'image' a specific 'data_file', \
5292 indexed by 'position'
5295 Installing a Linux Image:
5296 -------------------------
5298 To downloading a U-Boot image over the serial (console) interface,
5299 you must convert the image to S-Record format:
5301 objcopy -I binary -O srec examples/image examples/image.srec
5303 The 'objcopy' does not understand the information in the U-Boot
5304 image header, so the resulting S-Record file will be relative to
5305 address 0x00000000. To load it to a given address, you need to
5306 specify the target address as 'offset' parameter with the 'loads'
5309 Example: install the image to address 0x40100000 (which on the
5310 TQM8xxL is in the first Flash bank):
5312 => erase 40100000 401FFFFF
5318 ## Ready for S-Record download ...
5319 ~>examples/image.srec
5320 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5322 15989 15990 15991 15992
5323 [file transfer complete]
5325 ## Start Addr = 0x00000000
5328 You can check the success of the download using the 'iminfo' command;
5329 this includes a checksum verification so you can be sure no data
5330 corruption happened:
5334 ## Checking Image at 40100000 ...
5335 Image Name: 2.2.13 for initrd on TQM850L
5336 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5337 Data Size: 335725 Bytes = 327 kB = 0 MB
5338 Load Address: 00000000
5339 Entry Point: 0000000c
5340 Verifying Checksum ... OK
5346 The "bootm" command is used to boot an application that is stored in
5347 memory (RAM or Flash). In case of a Linux kernel image, the contents
5348 of the "bootargs" environment variable is passed to the kernel as
5349 parameters. You can check and modify this variable using the
5350 "printenv" and "setenv" commands:
5353 => printenv bootargs
5354 bootargs=root=/dev/ram
5356 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5358 => printenv bootargs
5359 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5362 ## Booting Linux kernel at 40020000 ...
5363 Image Name: 2.2.13 for NFS on TQM850L
5364 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5365 Data Size: 381681 Bytes = 372 kB = 0 MB
5366 Load Address: 00000000
5367 Entry Point: 0000000c
5368 Verifying Checksum ... OK
5369 Uncompressing Kernel Image ... OK
5370 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
5371 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5372 time_init: decrementer frequency = 187500000/60
5373 Calibrating delay loop... 49.77 BogoMIPS
5374 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5377 If you want to boot a Linux kernel with initial RAM disk, you pass
5378 the memory addresses of both the kernel and the initrd image (PPBCOOT
5379 format!) to the "bootm" command:
5381 => imi 40100000 40200000
5383 ## Checking Image at 40100000 ...
5384 Image Name: 2.2.13 for initrd on TQM850L
5385 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5386 Data Size: 335725 Bytes = 327 kB = 0 MB
5387 Load Address: 00000000
5388 Entry Point: 0000000c
5389 Verifying Checksum ... OK
5391 ## Checking Image at 40200000 ...
5392 Image Name: Simple Ramdisk Image
5393 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5394 Data Size: 566530 Bytes = 553 kB = 0 MB
5395 Load Address: 00000000
5396 Entry Point: 00000000
5397 Verifying Checksum ... OK
5399 => bootm 40100000 40200000
5400 ## Booting Linux kernel at 40100000 ...
5401 Image Name: 2.2.13 for initrd on TQM850L
5402 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5403 Data Size: 335725 Bytes = 327 kB = 0 MB
5404 Load Address: 00000000
5405 Entry Point: 0000000c
5406 Verifying Checksum ... OK
5407 Uncompressing Kernel Image ... OK
5408 ## Loading RAMDisk Image at 40200000 ...
5409 Image Name: Simple Ramdisk Image
5410 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5411 Data Size: 566530 Bytes = 553 kB = 0 MB
5412 Load Address: 00000000
5413 Entry Point: 00000000
5414 Verifying Checksum ... OK
5415 Loading Ramdisk ... OK
5416 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
5417 Boot arguments: root=/dev/ram
5418 time_init: decrementer frequency = 187500000/60
5419 Calibrating delay loop... 49.77 BogoMIPS
5421 RAMDISK: Compressed image found at block 0
5422 VFS: Mounted root (ext2 filesystem).
5426 Boot Linux and pass a flat device tree:
5429 First, U-Boot must be compiled with the appropriate defines. See the section
5430 titled "Linux Kernel Interface" above for a more in depth explanation. The
5431 following is an example of how to start a kernel and pass an updated
5437 oft=oftrees/mpc8540ads.dtb
5438 => tftp $oftaddr $oft
5439 Speed: 1000, full duplex
5441 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5442 Filename 'oftrees/mpc8540ads.dtb'.
5443 Load address: 0x300000
5446 Bytes transferred = 4106 (100a hex)
5447 => tftp $loadaddr $bootfile
5448 Speed: 1000, full duplex
5450 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5452 Load address: 0x200000
5453 Loading:############
5455 Bytes transferred = 1029407 (fb51f hex)
5460 => bootm $loadaddr - $oftaddr
5461 ## Booting image at 00200000 ...
5462 Image Name: Linux-2.6.17-dirty
5463 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5464 Data Size: 1029343 Bytes = 1005.2 kB
5465 Load Address: 00000000
5466 Entry Point: 00000000
5467 Verifying Checksum ... OK
5468 Uncompressing Kernel Image ... OK
5469 Booting using flat device tree at 0x300000
5470 Using MPC85xx ADS machine description
5471 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5475 More About U-Boot Image Types:
5476 ------------------------------
5478 U-Boot supports the following image types:
5480 "Standalone Programs" are directly runnable in the environment
5481 provided by U-Boot; it is expected that (if they behave
5482 well) you can continue to work in U-Boot after return from
5483 the Standalone Program.
5484 "OS Kernel Images" are usually images of some Embedded OS which
5485 will take over control completely. Usually these programs
5486 will install their own set of exception handlers, device
5487 drivers, set up the MMU, etc. - this means, that you cannot
5488 expect to re-enter U-Boot except by resetting the CPU.
5489 "RAMDisk Images" are more or less just data blocks, and their
5490 parameters (address, size) are passed to an OS kernel that is
5492 "Multi-File Images" contain several images, typically an OS
5493 (Linux) kernel image and one or more data images like
5494 RAMDisks. This construct is useful for instance when you want
5495 to boot over the network using BOOTP etc., where the boot
5496 server provides just a single image file, but you want to get
5497 for instance an OS kernel and a RAMDisk image.
5499 "Multi-File Images" start with a list of image sizes, each
5500 image size (in bytes) specified by an "uint32_t" in network
5501 byte order. This list is terminated by an "(uint32_t)0".
5502 Immediately after the terminating 0 follow the images, one by
5503 one, all aligned on "uint32_t" boundaries (size rounded up to
5504 a multiple of 4 bytes).
5506 "Firmware Images" are binary images containing firmware (like
5507 U-Boot or FPGA images) which usually will be programmed to
5510 "Script files" are command sequences that will be executed by
5511 U-Boot's command interpreter; this feature is especially
5512 useful when you configure U-Boot to use a real shell (hush)
5513 as command interpreter.
5515 Booting the Linux zImage:
5516 -------------------------
5518 On some platforms, it's possible to boot Linux zImage. This is done
5519 using the "bootz" command. The syntax of "bootz" command is the same
5520 as the syntax of "bootm" command.
5522 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5523 kernel with raw initrd images. The syntax is slightly different, the
5524 address of the initrd must be augmented by it's size, in the following
5525 format: "<initrd addres>:<initrd size>".
5531 One of the features of U-Boot is that you can dynamically load and
5532 run "standalone" applications, which can use some resources of
5533 U-Boot like console I/O functions or interrupt services.
5535 Two simple examples are included with the sources:
5540 'examples/hello_world.c' contains a small "Hello World" Demo
5541 application; it is automatically compiled when you build U-Boot.
5542 It's configured to run at address 0x00040004, so you can play with it
5546 ## Ready for S-Record download ...
5547 ~>examples/hello_world.srec
5548 1 2 3 4 5 6 7 8 9 10 11 ...
5549 [file transfer complete]
5551 ## Start Addr = 0x00040004
5553 => go 40004 Hello World! This is a test.
5554 ## Starting application at 0x00040004 ...
5565 Hit any key to exit ...
5567 ## Application terminated, rc = 0x0
5569 Another example, which demonstrates how to register a CPM interrupt
5570 handler with the U-Boot code, can be found in 'examples/timer.c'.
5571 Here, a CPM timer is set up to generate an interrupt every second.
5572 The interrupt service routine is trivial, just printing a '.'
5573 character, but this is just a demo program. The application can be
5574 controlled by the following keys:
5576 ? - print current values og the CPM Timer registers
5577 b - enable interrupts and start timer
5578 e - stop timer and disable interrupts
5579 q - quit application
5582 ## Ready for S-Record download ...
5583 ~>examples/timer.srec
5584 1 2 3 4 5 6 7 8 9 10 11 ...
5585 [file transfer complete]
5587 ## Start Addr = 0x00040004
5590 ## Starting application at 0x00040004 ...
5593 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5596 [q, b, e, ?] Set interval 1000000 us
5599 [q, b, e, ?] ........
5600 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5603 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5606 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5609 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5611 [q, b, e, ?] ...Stopping timer
5613 [q, b, e, ?] ## Application terminated, rc = 0x0
5619 Over time, many people have reported problems when trying to use the
5620 "minicom" terminal emulation program for serial download. I (wd)
5621 consider minicom to be broken, and recommend not to use it. Under
5622 Unix, I recommend to use C-Kermit for general purpose use (and
5623 especially for kermit binary protocol download ("loadb" command), and
5624 use "cu" for S-Record download ("loads" command). See
5625 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5626 for help with kermit.
5629 Nevertheless, if you absolutely want to use it try adding this
5630 configuration to your "File transfer protocols" section:
5632 Name Program Name U/D FullScr IO-Red. Multi
5633 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5634 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5640 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5641 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5643 Building requires a cross environment; it is known to work on
5644 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5645 need gmake since the Makefiles are not compatible with BSD make).
5646 Note that the cross-powerpc package does not install include files;
5647 attempting to build U-Boot will fail because <machine/ansi.h> is
5648 missing. This file has to be installed and patched manually:
5650 # cd /usr/pkg/cross/powerpc-netbsd/include
5652 # ln -s powerpc machine
5653 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5654 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5656 Native builds *don't* work due to incompatibilities between native
5657 and U-Boot include files.
5659 Booting assumes that (the first part of) the image booted is a
5660 stage-2 loader which in turn loads and then invokes the kernel
5661 proper. Loader sources will eventually appear in the NetBSD source
5662 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5663 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5666 Implementation Internals:
5667 =========================
5669 The following is not intended to be a complete description of every
5670 implementation detail. However, it should help to understand the
5671 inner workings of U-Boot and make it easier to port it to custom
5675 Initial Stack, Global Data:
5676 ---------------------------
5678 The implementation of U-Boot is complicated by the fact that U-Boot
5679 starts running out of ROM (flash memory), usually without access to
5680 system RAM (because the memory controller is not initialized yet).
5681 This means that we don't have writable Data or BSS segments, and BSS
5682 is not initialized as zero. To be able to get a C environment working
5683 at all, we have to allocate at least a minimal stack. Implementation
5684 options for this are defined and restricted by the CPU used: Some CPU
5685 models provide on-chip memory (like the IMMR area on MPC8xx and
5686 MPC826x processors), on others (parts of) the data cache can be
5687 locked as (mis-) used as memory, etc.
5689 Chris Hallinan posted a good summary of these issues to the
5690 U-Boot mailing list:
5692 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5693 From: "Chris Hallinan" <clh@net1plus.com>
5694 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5697 Correct me if I'm wrong, folks, but the way I understand it
5698 is this: Using DCACHE as initial RAM for Stack, etc, does not
5699 require any physical RAM backing up the cache. The cleverness
5700 is that the cache is being used as a temporary supply of
5701 necessary storage before the SDRAM controller is setup. It's
5702 beyond the scope of this list to explain the details, but you
5703 can see how this works by studying the cache architecture and
5704 operation in the architecture and processor-specific manuals.
5706 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5707 is another option for the system designer to use as an
5708 initial stack/RAM area prior to SDRAM being available. Either
5709 option should work for you. Using CS 4 should be fine if your
5710 board designers haven't used it for something that would
5711 cause you grief during the initial boot! It is frequently not
5714 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5715 with your processor/board/system design. The default value
5716 you will find in any recent u-boot distribution in
5717 walnut.h should work for you. I'd set it to a value larger
5718 than your SDRAM module. If you have a 64MB SDRAM module, set
5719 it above 400_0000. Just make sure your board has no resources
5720 that are supposed to respond to that address! That code in
5721 start.S has been around a while and should work as is when
5722 you get the config right.
5727 It is essential to remember this, since it has some impact on the C
5728 code for the initialization procedures:
5730 * Initialized global data (data segment) is read-only. Do not attempt
5733 * Do not use any uninitialized global data (or implicitely initialized
5734 as zero data - BSS segment) at all - this is undefined, initiali-
5735 zation is performed later (when relocating to RAM).
5737 * Stack space is very limited. Avoid big data buffers or things like
5740 Having only the stack as writable memory limits means we cannot use
5741 normal global data to share information beween the code. But it
5742 turned out that the implementation of U-Boot can be greatly
5743 simplified by making a global data structure (gd_t) available to all
5744 functions. We could pass a pointer to this data as argument to _all_
5745 functions, but this would bloat the code. Instead we use a feature of
5746 the GCC compiler (Global Register Variables) to share the data: we
5747 place a pointer (gd) to the global data into a register which we
5748 reserve for this purpose.
5750 When choosing a register for such a purpose we are restricted by the
5751 relevant (E)ABI specifications for the current architecture, and by
5752 GCC's implementation.
5754 For PowerPC, the following registers have specific use:
5756 R2: reserved for system use
5757 R3-R4: parameter passing and return values
5758 R5-R10: parameter passing
5759 R13: small data area pointer
5763 (U-Boot also uses R12 as internal GOT pointer. r12
5764 is a volatile register so r12 needs to be reset when
5765 going back and forth between asm and C)
5767 ==> U-Boot will use R2 to hold a pointer to the global data
5769 Note: on PPC, we could use a static initializer (since the
5770 address of the global data structure is known at compile time),
5771 but it turned out that reserving a register results in somewhat
5772 smaller code - although the code savings are not that big (on
5773 average for all boards 752 bytes for the whole U-Boot image,
5774 624 text + 127 data).
5776 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5777 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5779 ==> U-Boot will use P3 to hold a pointer to the global data
5781 On ARM, the following registers are used:
5783 R0: function argument word/integer result
5784 R1-R3: function argument word
5785 R9: platform specific
5786 R10: stack limit (used only if stack checking is enabled)
5787 R11: argument (frame) pointer
5788 R12: temporary workspace
5791 R15: program counter
5793 ==> U-Boot will use R9 to hold a pointer to the global data
5795 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5797 On Nios II, the ABI is documented here:
5798 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5800 ==> U-Boot will use gp to hold a pointer to the global data
5802 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5803 to access small data sections, so gp is free.
5805 On NDS32, the following registers are used:
5807 R0-R1: argument/return
5809 R15: temporary register for assembler
5810 R16: trampoline register
5811 R28: frame pointer (FP)
5812 R29: global pointer (GP)
5813 R30: link register (LP)
5814 R31: stack pointer (SP)
5815 PC: program counter (PC)
5817 ==> U-Boot will use R10 to hold a pointer to the global data
5819 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5820 or current versions of GCC may "optimize" the code too much.
5825 U-Boot runs in system state and uses physical addresses, i.e. the
5826 MMU is not used either for address mapping nor for memory protection.
5828 The available memory is mapped to fixed addresses using the memory
5829 controller. In this process, a contiguous block is formed for each
5830 memory type (Flash, SDRAM, SRAM), even when it consists of several
5831 physical memory banks.
5833 U-Boot is installed in the first 128 kB of the first Flash bank (on
5834 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5835 booting and sizing and initializing DRAM, the code relocates itself
5836 to the upper end of DRAM. Immediately below the U-Boot code some
5837 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5838 configuration setting]. Below that, a structure with global Board
5839 Info data is placed, followed by the stack (growing downward).
5841 Additionally, some exception handler code is copied to the low 8 kB
5842 of DRAM (0x00000000 ... 0x00001FFF).
5844 So a typical memory configuration with 16 MB of DRAM could look like
5847 0x0000 0000 Exception Vector code
5850 0x0000 2000 Free for Application Use
5856 0x00FB FF20 Monitor Stack (Growing downward)
5857 0x00FB FFAC Board Info Data and permanent copy of global data
5858 0x00FC 0000 Malloc Arena
5861 0x00FE 0000 RAM Copy of Monitor Code
5862 ... eventually: LCD or video framebuffer
5863 ... eventually: pRAM (Protected RAM - unchanged by reset)
5864 0x00FF FFFF [End of RAM]
5867 System Initialization:
5868 ----------------------
5870 In the reset configuration, U-Boot starts at the reset entry point
5871 (on most PowerPC systems at address 0x00000100). Because of the reset
5872 configuration for CS0# this is a mirror of the onboard Flash memory.
5873 To be able to re-map memory U-Boot then jumps to its link address.
5874 To be able to implement the initialization code in C, a (small!)
5875 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5876 which provide such a feature like MPC8xx or MPC8260), or in a locked
5877 part of the data cache. After that, U-Boot initializes the CPU core,
5878 the caches and the SIU.
5880 Next, all (potentially) available memory banks are mapped using a
5881 preliminary mapping. For example, we put them on 512 MB boundaries
5882 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5883 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5884 programmed for SDRAM access. Using the temporary configuration, a
5885 simple memory test is run that determines the size of the SDRAM
5888 When there is more than one SDRAM bank, and the banks are of
5889 different size, the largest is mapped first. For equal size, the first
5890 bank (CS2#) is mapped first. The first mapping is always for address
5891 0x00000000, with any additional banks following immediately to create
5892 contiguous memory starting from 0.
5894 Then, the monitor installs itself at the upper end of the SDRAM area
5895 and allocates memory for use by malloc() and for the global Board
5896 Info data; also, the exception vector code is copied to the low RAM
5897 pages, and the final stack is set up.
5899 Only after this relocation will you have a "normal" C environment;
5900 until that you are restricted in several ways, mostly because you are
5901 running from ROM, and because the code will have to be relocated to a
5905 U-Boot Porting Guide:
5906 ----------------------
5908 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5912 int main(int argc, char *argv[])
5914 sighandler_t no_more_time;
5916 signal(SIGALRM, no_more_time);
5917 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5919 if (available_money > available_manpower) {
5920 Pay consultant to port U-Boot;
5924 Download latest U-Boot source;
5926 Subscribe to u-boot mailing list;
5929 email("Hi, I am new to U-Boot, how do I get started?");
5932 Read the README file in the top level directory;
5933 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5934 Read applicable doc/*.README;
5935 Read the source, Luke;
5936 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5939 if (available_money > toLocalCurrency ($2500))
5942 Add a lot of aggravation and time;
5944 if (a similar board exists) { /* hopefully... */
5945 cp -a board/<similar> board/<myboard>
5946 cp include/configs/<similar>.h include/configs/<myboard>.h
5948 Create your own board support subdirectory;
5949 Create your own board include/configs/<myboard>.h file;
5951 Edit new board/<myboard> files
5952 Edit new include/configs/<myboard>.h
5957 Add / modify source code;
5961 email("Hi, I am having problems...");
5963 Send patch file to the U-Boot email list;
5964 if (reasonable critiques)
5965 Incorporate improvements from email list code review;
5967 Defend code as written;
5973 void no_more_time (int sig)
5982 All contributions to U-Boot should conform to the Linux kernel
5983 coding style; see the file "Documentation/CodingStyle" and the script
5984 "scripts/Lindent" in your Linux kernel source directory.
5986 Source files originating from a different project (for example the
5987 MTD subsystem) are generally exempt from these guidelines and are not
5988 reformated to ease subsequent migration to newer versions of those
5991 Please note that U-Boot is implemented in C (and to some small parts in
5992 Assembler); no C++ is used, so please do not use C++ style comments (//)
5995 Please also stick to the following formatting rules:
5996 - remove any trailing white space
5997 - use TAB characters for indentation and vertical alignment, not spaces
5998 - make sure NOT to use DOS '\r\n' line feeds
5999 - do not add more than 2 consecutive empty lines to source files
6000 - do not add trailing empty lines to source files
6002 Submissions which do not conform to the standards may be returned
6003 with a request to reformat the changes.
6009 Since the number of patches for U-Boot is growing, we need to
6010 establish some rules. Submissions which do not conform to these rules
6011 may be rejected, even when they contain important and valuable stuff.
6013 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6015 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6016 see http://lists.denx.de/mailman/listinfo/u-boot
6018 When you send a patch, please include the following information with
6021 * For bug fixes: a description of the bug and how your patch fixes
6022 this bug. Please try to include a way of demonstrating that the
6023 patch actually fixes something.
6025 * For new features: a description of the feature and your
6028 * A CHANGELOG entry as plaintext (separate from the patch)
6030 * For major contributions, your entry to the CREDITS file
6032 * When you add support for a new board, don't forget to add a
6033 maintainer e-mail address to the boards.cfg file, too.
6035 * If your patch adds new configuration options, don't forget to
6036 document these in the README file.
6038 * The patch itself. If you are using git (which is *strongly*
6039 recommended) you can easily generate the patch using the
6040 "git format-patch". If you then use "git send-email" to send it to
6041 the U-Boot mailing list, you will avoid most of the common problems
6042 with some other mail clients.
6044 If you cannot use git, use "diff -purN OLD NEW". If your version of
6045 diff does not support these options, then get the latest version of
6048 The current directory when running this command shall be the parent
6049 directory of the U-Boot source tree (i. e. please make sure that
6050 your patch includes sufficient directory information for the
6053 We prefer patches as plain text. MIME attachments are discouraged,
6054 and compressed attachments must not be used.
6056 * If one logical set of modifications affects or creates several
6057 files, all these changes shall be submitted in a SINGLE patch file.
6059 * Changesets that contain different, unrelated modifications shall be
6060 submitted as SEPARATE patches, one patch per changeset.
6065 * Before sending the patch, run the MAKEALL script on your patched
6066 source tree and make sure that no errors or warnings are reported
6067 for any of the boards.
6069 * Keep your modifications to the necessary minimum: A patch
6070 containing several unrelated changes or arbitrary reformats will be
6071 returned with a request to re-formatting / split it.
6073 * If you modify existing code, make sure that your new code does not
6074 add to the memory footprint of the code ;-) Small is beautiful!
6075 When adding new features, these should compile conditionally only
6076 (using #ifdef), and the resulting code with the new feature
6077 disabled must not need more memory than the old code without your
6080 * Remember that there is a size limit of 100 kB per message on the
6081 u-boot mailing list. Bigger patches will be moderated. If they are
6082 reasonable and not too big, they will be acknowledged. But patches
6083 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob