2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /ixp Files specific to Intel XScale IXP CPUs
145 /pxa Files specific to Intel XScale PXA CPUs
146 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
147 /lib Architecture specific library files
148 /avr32 Files generic to AVR32 architecture
149 /cpu CPU specific files
150 /lib Architecture specific library files
151 /blackfin Files generic to Analog Devices Blackfin architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /m68k Files generic to m68k architecture
155 /cpu CPU specific files
156 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 /lib Architecture specific library files
162 /microblaze Files generic to microblaze architecture
163 /cpu CPU specific files
164 /lib Architecture specific library files
165 /mips Files generic to MIPS architecture
166 /cpu CPU specific files
167 /mips32 Files specific to MIPS32 CPUs
168 /xburst Files specific to Ingenic XBurst CPUs
169 /lib Architecture specific library files
170 /nds32 Files generic to NDS32 architecture
171 /cpu CPU specific files
172 /n1213 Files specific to Andes Technology N1213 CPUs
173 /lib Architecture specific library files
174 /nios2 Files generic to Altera NIOS2 architecture
175 /cpu CPU specific files
176 /lib Architecture specific library files
177 /openrisc Files generic to OpenRISC architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /powerpc Files generic to PowerPC architecture
181 /cpu CPU specific files
182 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
183 /mpc5xx Files specific to Freescale MPC5xx CPUs
184 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
185 /mpc8xx Files specific to Freescale MPC8xx CPUs
186 /mpc824x Files specific to Freescale MPC824x CPUs
187 /mpc8260 Files specific to Freescale MPC8260 CPUs
188 /mpc85xx Files specific to Freescale MPC85xx CPUs
189 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
190 /lib Architecture specific library files
191 /sh Files generic to SH architecture
192 /cpu CPU specific files
193 /sh2 Files specific to sh2 CPUs
194 /sh3 Files specific to sh3 CPUs
195 /sh4 Files specific to sh4 CPUs
196 /lib Architecture specific library files
197 /sparc Files generic to SPARC architecture
198 /cpu CPU specific files
199 /leon2 Files specific to Gaisler LEON2 SPARC CPU
200 /leon3 Files specific to Gaisler LEON3 SPARC CPU
201 /lib Architecture specific library files
202 /x86 Files generic to x86 architecture
203 /cpu CPU specific files
204 /lib Architecture specific library files
205 /api Machine/arch independent API for external apps
206 /board Board dependent files
207 /common Misc architecture independent functions
208 /disk Code for disk drive partition handling
209 /doc Documentation (don't expect too much)
210 /drivers Commonly used device drivers
211 /dts Contains Makefile for building internal U-Boot fdt.
212 /examples Example code for standalone applications, etc.
213 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
214 /include Header Files
215 /lib Files generic to all architectures
216 /libfdt Library files to support flattened device trees
217 /lzma Library files to support LZMA decompression
218 /lzo Library files to support LZO decompression
220 /post Power On Self Test
221 /spl Secondary Program Loader framework
222 /tools Tools to build S-Record or U-Boot images, etc.
224 Software Configuration:
225 =======================
227 Configuration is usually done using C preprocessor defines; the
228 rationale behind that is to avoid dead code whenever possible.
230 There are two classes of configuration variables:
232 * Configuration _OPTIONS_:
233 These are selectable by the user and have names beginning with
236 * Configuration _SETTINGS_:
237 These depend on the hardware etc. and should not be meddled with if
238 you don't know what you're doing; they have names beginning with
241 Later we will add a configuration tool - probably similar to or even
242 identical to what's used for the Linux kernel. Right now, we have to
243 do the configuration by hand, which means creating some symbolic
244 links and editing some configuration files. We use the TQM8xxL boards
248 Selection of Processor Architecture and Board Type:
249 ---------------------------------------------------
251 For all supported boards there are ready-to-use default
252 configurations available; just type "make <board_name>_config".
254 Example: For a TQM823L module type:
259 For the Cogent platform, you need to specify the CPU type as well;
260 e.g. "make cogent_mpc8xx_config". And also configure the cogent
261 directory according to the instructions in cogent/README.
264 Configuration Options:
265 ----------------------
267 Configuration depends on the combination of board and CPU type; all
268 such information is kept in a configuration file
269 "include/configs/<board_name>.h".
271 Example: For a TQM823L module, all configuration settings are in
272 "include/configs/TQM823L.h".
275 Many of the options are named exactly as the corresponding Linux
276 kernel configuration options. The intention is to make it easier to
277 build a config tool - later.
280 The following options need to be configured:
282 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
284 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
286 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
287 Define exactly one, e.g. CONFIG_ATSTK1002
289 - CPU Module Type: (if CONFIG_COGENT is defined)
290 Define exactly one of
292 --- FIXME --- not tested yet:
293 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
294 CONFIG_CMA287_23, CONFIG_CMA287_50
296 - Motherboard Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
298 CONFIG_CMA101, CONFIG_CMA102
300 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
301 Define one or more of
304 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
305 Define one or more of
306 CONFIG_LCD_HEARTBEAT - update a character position on
307 the LCD display every second with
310 - Board flavour: (if CONFIG_MPC8260ADS is defined)
313 CONFIG_SYS_8260ADS - original MPC8260ADS
314 CONFIG_SYS_8266ADS - MPC8266ADS
315 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
316 CONFIG_SYS_8272ADS - MPC8272ADS
318 - Marvell Family Member
319 CONFIG_SYS_MVFS - define it if you want to enable
320 multiple fs option at one time
321 for marvell soc family
323 - MPC824X Family Member (if CONFIG_MPC824X is defined)
324 Define exactly one of
325 CONFIG_MPC8240, CONFIG_MPC8245
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 requred during NOR boot.
406 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
408 This is the value to write into CCSR offset 0x18600
409 according to the A004510 workaround.
411 CONFIG_SYS_FSL_DSP_DDR_ADDR
412 This value denotes start offset of DDR memory which is
413 connected exclusively to the DSP cores.
415 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
416 This value denotes start offset of M2 memory
417 which is directly connected to the DSP core.
419 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
420 This value denotes start offset of M3 memory which is directly
421 connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
424 This value denotes start offset of DSP CCSR space.
426 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
427 Single Source Clock is clocking mode present in some of FSL SoC's.
428 In this mode, a single differential clock is used to supply
429 clocks to the sysclock, ddrclock and usbclock.
431 - Generic CPU options:
432 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
434 Defines the endianess of the CPU. Implementation of those
435 values is arch specific.
438 Freescale DDR driver in use. This type of DDR controller is
439 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
442 CONFIG_SYS_FSL_DDR_ADDR
443 Freescale DDR memory-mapped register base.
445 CONFIG_SYS_FSL_DDR_EMU
446 Specify emulator support for DDR. Some DDR features such as
447 deskew training are not available.
449 CONFIG_SYS_FSL_DDRC_GEN1
450 Freescale DDR1 controller.
452 CONFIG_SYS_FSL_DDRC_GEN2
453 Freescale DDR2 controller.
455 CONFIG_SYS_FSL_DDRC_GEN3
456 Freescale DDR3 controller.
458 CONFIG_SYS_FSL_DDRC_ARM_GEN3
459 Freescale DDR3 controller for ARM-based SoCs.
462 Board config to use DDR1. It can be enabled for SoCs with
463 Freescale DDR1 or DDR2 controllers, depending on the board
467 Board config to use DDR2. It can be eanbeld for SoCs with
468 Freescale DDR2 or DDR3 controllers, depending on the board
472 Board config to use DDR3. It can be enabled for SoCs with
473 Freescale DDR3 controllers.
475 CONFIG_SYS_FSL_IFC_BE
476 Defines the IFC controller register space as Big Endian
478 CONFIG_SYS_FSL_IFC_LE
479 Defines the IFC controller register space as Little Endian
481 CONFIG_SYS_FSL_PBL_PBI
482 It enables addition of RCW (Power on reset configuration) in built image.
483 Please refer doc/README.pblimage for more details
485 CONFIG_SYS_FSL_PBL_RCW
486 It adds PBI(pre-boot instructions) commands in u-boot build image.
487 PBI commands can be used to configure SoC before it starts the execution.
488 Please refer doc/README.pblimage for more details
490 - Intel Monahans options:
491 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
493 Defines the Monahans run mode to oscillator
494 ratio. Valid values are 8, 16, 24, 31. The core
495 frequency is this value multiplied by 13 MHz.
497 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
499 Defines the Monahans turbo mode to oscillator
500 ratio. Valid values are 1 (default if undefined) and
501 2. The core frequency as calculated above is multiplied
505 CONFIG_SYS_INIT_SP_OFFSET
507 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
508 pointer. This is needed for the temporary stack before
511 CONFIG_SYS_MIPS_CACHE_MODE
513 Cache operation mode for the MIPS CPU.
514 See also arch/mips/include/asm/mipsregs.h.
516 CONF_CM_CACHABLE_NO_WA
519 CONF_CM_CACHABLE_NONCOHERENT
523 CONF_CM_CACHABLE_ACCELERATED
525 CONFIG_SYS_XWAY_EBU_BOOTCFG
527 Special option for Lantiq XWAY SoCs for booting from NOR flash.
528 See also arch/mips/cpu/mips32/start.S.
530 CONFIG_XWAY_SWAP_BYTES
532 Enable compilation of tools/xway-swap-bytes needed for Lantiq
533 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
534 be swapped if a flash programmer is used.
537 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
539 Select high exception vectors of the ARM core, e.g., do not
540 clear the V bit of the c1 register of CP15.
542 CONFIG_SYS_THUMB_BUILD
544 Use this flag to build U-Boot using the Thumb instruction
545 set for ARM architectures. Thumb instruction set provides
546 better code density. For ARM architectures that support
547 Thumb2 this flag will result in Thumb2 code generated by
550 CONFIG_ARM_ERRATA_716044
551 CONFIG_ARM_ERRATA_742230
552 CONFIG_ARM_ERRATA_743622
553 CONFIG_ARM_ERRATA_751472
555 If set, the workarounds for these ARM errata are applied early
556 during U-Boot startup. Note that these options force the
557 workarounds to be applied; no CPU-type/version detection
558 exists, unlike the similar options in the Linux kernel. Do not
559 set these options unless they apply!
564 The frequency of the timer returned by get_timer().
565 get_timer() must operate in milliseconds and this CONFIG
566 option must be set to 1000.
568 - Linux Kernel Interface:
571 U-Boot stores all clock information in Hz
572 internally. For binary compatibility with older Linux
573 kernels (which expect the clocks passed in the
574 bd_info data to be in MHz) the environment variable
575 "clocks_in_mhz" can be defined so that U-Boot
576 converts clock data to MHZ before passing it to the
578 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
579 "clocks_in_mhz=1" is automatically included in the
582 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
584 When transferring memsize parameter to linux, some versions
585 expect it to be in bytes, others in MB.
586 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
590 New kernel versions are expecting firmware settings to be
591 passed using flattened device trees (based on open firmware
595 * New libfdt-based support
596 * Adds the "fdt" command
597 * The bootm command automatically updates the fdt
599 OF_CPU - The proper name of the cpus node (only required for
600 MPC512X and MPC5xxx based boards).
601 OF_SOC - The proper name of the soc node (only required for
602 MPC512X and MPC5xxx based boards).
603 OF_TBCLK - The timebase frequency.
604 OF_STDOUT_PATH - The path to the console device
606 boards with QUICC Engines require OF_QE to set UCC MAC
609 CONFIG_OF_BOARD_SETUP
611 Board code has addition modification that it wants to make
612 to the flat device tree before handing it off to the kernel
616 This define fills in the correct boot CPU in the boot
617 param header, the default value is zero if undefined.
621 U-Boot can detect if an IDE device is present or not.
622 If not, and this new config option is activated, U-Boot
623 removes the ATA node from the DTS before booting Linux,
624 so the Linux IDE driver does not probe the device and
625 crash. This is needed for buggy hardware (uc101) where
626 no pull down resistor is connected to the signal IDE5V_DD7.
628 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
630 This setting is mandatory for all boards that have only one
631 machine type and must be used to specify the machine type
632 number as it appears in the ARM machine registry
633 (see http://www.arm.linux.org.uk/developer/machines/).
634 Only boards that have multiple machine types supported
635 in a single configuration file and the machine type is
636 runtime discoverable, do not have to use this setting.
638 - vxWorks boot parameters:
640 bootvx constructs a valid bootline using the following
641 environments variables: bootfile, ipaddr, serverip, hostname.
642 It loads the vxWorks image pointed bootfile.
644 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
645 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
646 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
647 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
649 CONFIG_SYS_VXWORKS_ADD_PARAMS
651 Add it at the end of the bootline. E.g "u=username pw=secret"
653 Note: If a "bootargs" environment is defined, it will overwride
654 the defaults discussed just above.
656 - Cache Configuration:
657 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
658 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
659 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
661 - Cache Configuration for ARM:
662 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
664 CONFIG_SYS_PL310_BASE - Physical base address of PL310
665 controller register space
670 Define this if you want support for Amba PrimeCell PL010 UARTs.
674 Define this if you want support for Amba PrimeCell PL011 UARTs.
678 If you have Amba PrimeCell PL011 UARTs, set this variable to
679 the clock speed of the UARTs.
683 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
684 define this to a list of base addresses for each (supported)
685 port. See e.g. include/configs/versatile.h
687 CONFIG_PL011_SERIAL_RLCR
689 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
690 have separate receive and transmit line control registers. Set
691 this variable to initialize the extra register.
693 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
695 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
696 boot loader that has already initialized the UART. Define this
697 variable to flush the UART at init time.
701 Depending on board, define exactly one serial port
702 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
703 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
704 console by defining CONFIG_8xx_CONS_NONE
706 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
707 port routines must be defined elsewhere
708 (i.e. serial_init(), serial_getc(), ...)
711 Enables console device for a color framebuffer. Needs following
712 defines (cf. smiLynxEM, i8042)
713 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
715 VIDEO_HW_RECTFILL graphic chip supports
718 VIDEO_HW_BITBLT graphic chip supports
719 bit-blit (cf. smiLynxEM)
720 VIDEO_VISIBLE_COLS visible pixel columns
722 VIDEO_VISIBLE_ROWS visible pixel rows
723 VIDEO_PIXEL_SIZE bytes per pixel
724 VIDEO_DATA_FORMAT graphic data format
725 (0-5, cf. cfb_console.c)
726 VIDEO_FB_ADRS framebuffer address
727 VIDEO_KBD_INIT_FCT keyboard int fct
728 (i.e. i8042_kbd_init())
729 VIDEO_TSTC_FCT test char fct
731 VIDEO_GETC_FCT get char fct
733 CONFIG_CONSOLE_CURSOR cursor drawing on/off
734 (requires blink timer
736 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
737 CONFIG_CONSOLE_TIME display time/date info in
739 (requires CONFIG_CMD_DATE)
740 CONFIG_VIDEO_LOGO display Linux logo in
742 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
743 linux_logo.h for logo.
744 Requires CONFIG_VIDEO_LOGO
745 CONFIG_CONSOLE_EXTRA_INFO
746 additional board info beside
749 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
750 a limited number of ANSI escape sequences (cursor control,
751 erase functions and limited graphics rendition control).
753 When CONFIG_CFB_CONSOLE is defined, video console is
754 default i/o. Serial console can be forced with
755 environment 'console=serial'.
757 When CONFIG_SILENT_CONSOLE is defined, all console
758 messages (by U-Boot and Linux!) can be silenced with
759 the "silent" environment variable. See
760 doc/README.silent for more information.
762 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
764 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
768 CONFIG_BAUDRATE - in bps
769 Select one of the baudrates listed in
770 CONFIG_SYS_BAUDRATE_TABLE, see below.
771 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
773 - Console Rx buffer length
774 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
775 the maximum receive buffer length for the SMC.
776 This option is actual only for 82xx and 8xx possible.
777 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
778 must be defined, to setup the maximum idle timeout for
781 - Pre-Console Buffer:
782 Prior to the console being initialised (i.e. serial UART
783 initialised etc) all console output is silently discarded.
784 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
785 buffer any console messages prior to the console being
786 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
787 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
788 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
789 bytes are output before the console is initialised, the
790 earlier bytes are discarded.
792 'Sane' compilers will generate smaller code if
793 CONFIG_PRE_CON_BUF_SZ is a power of 2
795 - Safe printf() functions
796 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
797 the printf() functions. These are defined in
798 include/vsprintf.h and include snprintf(), vsnprintf() and
799 so on. Code size increase is approximately 300-500 bytes.
800 If this option is not given then these functions will
801 silently discard their buffer size argument - this means
802 you are not getting any overflow checking in this case.
804 - Boot Delay: CONFIG_BOOTDELAY - in seconds
805 Delay before automatically booting the default image;
806 set to -1 to disable autoboot.
807 set to -2 to autoboot with no delay and not check for abort
808 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
810 See doc/README.autoboot for these options that
811 work with CONFIG_BOOTDELAY. None are required.
812 CONFIG_BOOT_RETRY_TIME
813 CONFIG_BOOT_RETRY_MIN
814 CONFIG_AUTOBOOT_KEYED
815 CONFIG_AUTOBOOT_PROMPT
816 CONFIG_AUTOBOOT_DELAY_STR
817 CONFIG_AUTOBOOT_STOP_STR
818 CONFIG_AUTOBOOT_DELAY_STR2
819 CONFIG_AUTOBOOT_STOP_STR2
820 CONFIG_ZERO_BOOTDELAY_CHECK
821 CONFIG_RESET_TO_RETRY
825 Only needed when CONFIG_BOOTDELAY is enabled;
826 define a command string that is automatically executed
827 when no character is read on the console interface
828 within "Boot Delay" after reset.
831 This can be used to pass arguments to the bootm
832 command. The value of CONFIG_BOOTARGS goes into the
833 environment value "bootargs".
835 CONFIG_RAMBOOT and CONFIG_NFSBOOT
836 The value of these goes into the environment as
837 "ramboot" and "nfsboot" respectively, and can be used
838 as a convenience, when switching between booting from
842 CONFIG_BOOTCOUNT_LIMIT
843 Implements a mechanism for detecting a repeating reboot
845 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
848 If no softreset save registers are found on the hardware
849 "bootcount" is stored in the environment. To prevent a
850 saveenv on all reboots, the environment variable
851 "upgrade_available" is used. If "upgrade_available" is
852 0, "bootcount" is always 0, if "upgrade_available" is
853 1 "bootcount" is incremented in the environment.
854 So the Userspace Applikation must set the "upgrade_available"
855 and "bootcount" variable to 0, if a boot was successfully.
860 When this option is #defined, the existence of the
861 environment variable "preboot" will be checked
862 immediately before starting the CONFIG_BOOTDELAY
863 countdown and/or running the auto-boot command resp.
864 entering interactive mode.
866 This feature is especially useful when "preboot" is
867 automatically generated or modified. For an example
868 see the LWMON board specific code: here "preboot" is
869 modified when the user holds down a certain
870 combination of keys on the (special) keyboard when
873 - Serial Download Echo Mode:
875 If defined to 1, all characters received during a
876 serial download (using the "loads" command) are
877 echoed back. This might be needed by some terminal
878 emulations (like "cu"), but may as well just take
879 time on others. This setting #define's the initial
880 value of the "loads_echo" environment variable.
882 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
884 Select one of the baudrates listed in
885 CONFIG_SYS_BAUDRATE_TABLE, see below.
888 Monitor commands can be included or excluded
889 from the build by using the #include files
890 <config_cmd_all.h> and #undef'ing unwanted
891 commands, or using <config_cmd_default.h>
892 and augmenting with additional #define's
895 The default command configuration includes all commands
896 except those marked below with a "*".
898 CONFIG_CMD_ASKENV * ask for env variable
899 CONFIG_CMD_BDI bdinfo
900 CONFIG_CMD_BEDBUG * Include BedBug Debugger
901 CONFIG_CMD_BMP * BMP support
902 CONFIG_CMD_BSP * Board specific commands
903 CONFIG_CMD_BOOTD bootd
904 CONFIG_CMD_CACHE * icache, dcache
905 CONFIG_CMD_CLK * clock command support
906 CONFIG_CMD_CONSOLE coninfo
907 CONFIG_CMD_CRC32 * crc32
908 CONFIG_CMD_DATE * support for RTC, date/time...
909 CONFIG_CMD_DHCP * DHCP support
910 CONFIG_CMD_DIAG * Diagnostics
911 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
912 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
913 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
914 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
915 CONFIG_CMD_DTT * Digital Therm and Thermostat
916 CONFIG_CMD_ECHO echo arguments
917 CONFIG_CMD_EDITENV edit env variable
918 CONFIG_CMD_EEPROM * EEPROM read/write support
919 CONFIG_CMD_ELF * bootelf, bootvx
920 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
921 CONFIG_CMD_ENV_FLAGS * display details about env flags
922 CONFIG_CMD_ENV_EXISTS * check existence of env variable
923 CONFIG_CMD_EXPORTENV * export the environment
924 CONFIG_CMD_EXT2 * ext2 command support
925 CONFIG_CMD_EXT4 * ext4 command support
926 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
927 that work for multiple fs types
928 CONFIG_CMD_SAVEENV saveenv
929 CONFIG_CMD_FDC * Floppy Disk Support
930 CONFIG_CMD_FAT * FAT command support
931 CONFIG_CMD_FDOS * Dos diskette Support
932 CONFIG_CMD_FLASH flinfo, erase, protect
933 CONFIG_CMD_FPGA FPGA device initialization support
934 CONFIG_CMD_FUSE * Device fuse support
935 CONFIG_CMD_GETTIME * Get time since boot
936 CONFIG_CMD_GO * the 'go' command (exec code)
937 CONFIG_CMD_GREPENV * search environment
938 CONFIG_CMD_HASH * calculate hash / digest
939 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
940 CONFIG_CMD_I2C * I2C serial bus support
941 CONFIG_CMD_IDE * IDE harddisk support
942 CONFIG_CMD_IMI iminfo
943 CONFIG_CMD_IMLS List all images found in NOR flash
944 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
945 CONFIG_CMD_IMMAP * IMMR dump support
946 CONFIG_CMD_IMPORTENV * import an environment
947 CONFIG_CMD_INI * import data from an ini file into the env
948 CONFIG_CMD_IRQ * irqinfo
949 CONFIG_CMD_ITEST Integer/string test of 2 values
950 CONFIG_CMD_JFFS2 * JFFS2 Support
951 CONFIG_CMD_KGDB * kgdb
952 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
953 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
955 CONFIG_CMD_LOADB loadb
956 CONFIG_CMD_LOADS loads
957 CONFIG_CMD_MD5SUM * print md5 message digest
958 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
959 CONFIG_CMD_MEMINFO * Display detailed memory information
960 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
962 CONFIG_CMD_MEMTEST * mtest
963 CONFIG_CMD_MISC Misc functions like sleep etc
964 CONFIG_CMD_MMC * MMC memory mapped support
965 CONFIG_CMD_MII * MII utility commands
966 CONFIG_CMD_MTDPARTS * MTD partition support
967 CONFIG_CMD_NAND * NAND support
968 CONFIG_CMD_NET bootp, tftpboot, rarpboot
969 CONFIG_CMD_NFS NFS support
970 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
971 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
972 CONFIG_CMD_PCI * pciinfo
973 CONFIG_CMD_PCMCIA * PCMCIA support
974 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
976 CONFIG_CMD_PORTIO * Port I/O
977 CONFIG_CMD_READ * Read raw data from partition
978 CONFIG_CMD_REGINFO * Register dump
979 CONFIG_CMD_RUN run command in env variable
980 CONFIG_CMD_SANDBOX * sb command to access sandbox features
981 CONFIG_CMD_SAVES * save S record dump
982 CONFIG_CMD_SCSI * SCSI Support
983 CONFIG_CMD_SDRAM * print SDRAM configuration information
984 (requires CONFIG_CMD_I2C)
985 CONFIG_CMD_SETGETDCR Support for DCR Register access
987 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
988 CONFIG_CMD_SHA1SUM * print sha1 memory digest
989 (requires CONFIG_CMD_MEMORY)
990 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
991 CONFIG_CMD_SOURCE "source" command Support
992 CONFIG_CMD_SPI * SPI serial bus support
993 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
994 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
995 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
996 CONFIG_CMD_TIMER * access to the system tick timer
997 CONFIG_CMD_USB * USB support
998 CONFIG_CMD_CDP * Cisco Discover Protocol support
999 CONFIG_CMD_MFSL * Microblaze FSL support
1000 CONFIG_CMD_XIMG Load part of Multi Image
1003 EXAMPLE: If you want all functions except of network
1004 support you can write:
1006 #include "config_cmd_all.h"
1007 #undef CONFIG_CMD_NET
1010 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1012 Note: Don't enable the "icache" and "dcache" commands
1013 (configuration option CONFIG_CMD_CACHE) unless you know
1014 what you (and your U-Boot users) are doing. Data
1015 cache cannot be enabled on systems like the 8xx or
1016 8260 (where accesses to the IMMR region must be
1017 uncached), and it cannot be disabled on all other
1018 systems where we (mis-) use the data cache to hold an
1019 initial stack and some data.
1022 XXX - this list needs to get updated!
1024 - Regular expression support:
1026 If this variable is defined, U-Boot is linked against
1027 the SLRE (Super Light Regular Expression) library,
1028 which adds regex support to some commands, as for
1029 example "env grep" and "setexpr".
1033 If this variable is defined, U-Boot will use a device tree
1034 to configure its devices, instead of relying on statically
1035 compiled #defines in the board file. This option is
1036 experimental and only available on a few boards. The device
1037 tree is available in the global data as gd->fdt_blob.
1039 U-Boot needs to get its device tree from somewhere. This can
1040 be done using one of the two options below:
1043 If this variable is defined, U-Boot will embed a device tree
1044 binary in its image. This device tree file should be in the
1045 board directory and called <soc>-<board>.dts. The binary file
1046 is then picked up in board_init_f() and made available through
1047 the global data structure as gd->blob.
1050 If this variable is defined, U-Boot will build a device tree
1051 binary. It will be called u-boot.dtb. Architecture-specific
1052 code will locate it at run-time. Generally this works by:
1054 cat u-boot.bin u-boot.dtb >image.bin
1056 and in fact, U-Boot does this for you, creating a file called
1057 u-boot-dtb.bin which is useful in the common case. You can
1058 still use the individual files if you need something more
1063 If this variable is defined, it enables watchdog
1064 support for the SoC. There must be support in the SoC
1065 specific code for a watchdog. For the 8xx and 8260
1066 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1067 register. When supported for a specific SoC is
1068 available, then no further board specific code should
1069 be needed to use it.
1072 When using a watchdog circuitry external to the used
1073 SoC, then define this variable and provide board
1074 specific code for the "hw_watchdog_reset" function.
1077 CONFIG_VERSION_VARIABLE
1078 If this variable is defined, an environment variable
1079 named "ver" is created by U-Boot showing the U-Boot
1080 version as printed by the "version" command.
1081 Any change to this variable will be reverted at the
1086 When CONFIG_CMD_DATE is selected, the type of the RTC
1087 has to be selected, too. Define exactly one of the
1090 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1091 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1092 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1093 CONFIG_RTC_MC146818 - use MC146818 RTC
1094 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1095 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1096 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1097 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1098 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1099 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1100 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1101 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1104 Note that if the RTC uses I2C, then the I2C interface
1105 must also be configured. See I2C Support, below.
1108 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1110 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1111 chip-ngpio pairs that tell the PCA953X driver the number of
1112 pins supported by a particular chip.
1114 Note that if the GPIO device uses I2C, then the I2C interface
1115 must also be configured. See I2C Support, below.
1117 - Timestamp Support:
1119 When CONFIG_TIMESTAMP is selected, the timestamp
1120 (date and time) of an image is printed by image
1121 commands like bootm or iminfo. This option is
1122 automatically enabled when you select CONFIG_CMD_DATE .
1124 - Partition Labels (disklabels) Supported:
1125 Zero or more of the following:
1126 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1127 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1128 Intel architecture, USB sticks, etc.
1129 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1130 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1131 bootloader. Note 2TB partition limit; see
1133 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1135 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1136 CONFIG_CMD_SCSI) you must configure support for at
1137 least one non-MTD partition type as well.
1140 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1141 board configurations files but used nowhere!
1143 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1144 be performed by calling the function
1145 ide_set_reset(int reset)
1146 which has to be defined in a board specific file
1151 Set this to enable ATAPI support.
1156 Set this to enable support for disks larger than 137GB
1157 Also look at CONFIG_SYS_64BIT_LBA.
1158 Whithout these , LBA48 support uses 32bit variables and will 'only'
1159 support disks up to 2.1TB.
1161 CONFIG_SYS_64BIT_LBA:
1162 When enabled, makes the IDE subsystem use 64bit sector addresses.
1166 At the moment only there is only support for the
1167 SYM53C8XX SCSI controller; define
1168 CONFIG_SCSI_SYM53C8XX to enable it.
1170 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1171 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1172 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1173 maximum numbers of LUNs, SCSI ID's and target
1175 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1177 The environment variable 'scsidevs' is set to the number of
1178 SCSI devices found during the last scan.
1180 - NETWORK Support (PCI):
1182 Support for Intel 8254x/8257x gigabit chips.
1185 Utility code for direct access to the SPI bus on Intel 8257x.
1186 This does not do anything useful unless you set at least one
1187 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1189 CONFIG_E1000_SPI_GENERIC
1190 Allow generic access to the SPI bus on the Intel 8257x, for
1191 example with the "sspi" command.
1194 Management command for E1000 devices. When used on devices
1195 with SPI support you can reprogram the EEPROM from U-Boot.
1197 CONFIG_E1000_FALLBACK_MAC
1198 default MAC for empty EEPROM after production.
1201 Support for Intel 82557/82559/82559ER chips.
1202 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1203 write routine for first time initialisation.
1206 Support for Digital 2114x chips.
1207 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1208 modem chip initialisation (KS8761/QS6611).
1211 Support for National dp83815 chips.
1214 Support for National dp8382[01] gigabit chips.
1216 - NETWORK Support (other):
1218 CONFIG_DRIVER_AT91EMAC
1219 Support for AT91RM9200 EMAC.
1222 Define this to use reduced MII inteface
1224 CONFIG_DRIVER_AT91EMAC_QUIET
1225 If this defined, the driver is quiet.
1226 The driver doen't show link status messages.
1228 CONFIG_CALXEDA_XGMAC
1229 Support for the Calxeda XGMAC device
1232 Support for SMSC's LAN91C96 chips.
1234 CONFIG_LAN91C96_BASE
1235 Define this to hold the physical address
1236 of the LAN91C96's I/O space
1238 CONFIG_LAN91C96_USE_32_BIT
1239 Define this to enable 32 bit addressing
1242 Support for SMSC's LAN91C111 chip
1244 CONFIG_SMC91111_BASE
1245 Define this to hold the physical address
1246 of the device (I/O space)
1248 CONFIG_SMC_USE_32_BIT
1249 Define this if data bus is 32 bits
1251 CONFIG_SMC_USE_IOFUNCS
1252 Define this to use i/o functions instead of macros
1253 (some hardware wont work with macros)
1255 CONFIG_DRIVER_TI_EMAC
1256 Support for davinci emac
1258 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1259 Define this if you have more then 3 PHYs.
1262 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1264 CONFIG_FTGMAC100_EGIGA
1265 Define this to use GE link update with gigabit PHY.
1266 Define this if FTGMAC100 is connected to gigabit PHY.
1267 If your system has 10/100 PHY only, it might not occur
1268 wrong behavior. Because PHY usually return timeout or
1269 useless data when polling gigabit status and gigabit
1270 control registers. This behavior won't affect the
1271 correctnessof 10/100 link speed update.
1274 Support for SMSC's LAN911x and LAN921x chips
1277 Define this to hold the physical address
1278 of the device (I/O space)
1280 CONFIG_SMC911X_32_BIT
1281 Define this if data bus is 32 bits
1283 CONFIG_SMC911X_16_BIT
1284 Define this if data bus is 16 bits. If your processor
1285 automatically converts one 32 bit word to two 16 bit
1286 words you may also try CONFIG_SMC911X_32_BIT.
1289 Support for Renesas on-chip Ethernet controller
1291 CONFIG_SH_ETHER_USE_PORT
1292 Define the number of ports to be used
1294 CONFIG_SH_ETHER_PHY_ADDR
1295 Define the ETH PHY's address
1297 CONFIG_SH_ETHER_CACHE_WRITEBACK
1298 If this option is set, the driver enables cache flush.
1302 Support TPM devices.
1305 Support for i2c bus TPM devices. Only one device
1306 per system is supported at this time.
1308 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1309 Define the the i2c bus number for the TPM device
1311 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1312 Define the TPM's address on the i2c bus
1314 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1315 Define the burst count bytes upper limit
1317 CONFIG_TPM_ATMEL_TWI
1318 Support for Atmel TWI TPM device. Requires I2C support.
1321 Support for generic parallel port TPM devices. Only one device
1322 per system is supported at this time.
1324 CONFIG_TPM_TIS_BASE_ADDRESS
1325 Base address where the generic TPM device is mapped
1326 to. Contemporary x86 systems usually map it at
1330 Add tpm monitor functions.
1331 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1332 provides monitor access to authorized functions.
1335 Define this to enable the TPM support library which provides
1336 functional interfaces to some TPM commands.
1337 Requires support for a TPM device.
1339 CONFIG_TPM_AUTH_SESSIONS
1340 Define this to enable authorized functions in the TPM library.
1341 Requires CONFIG_TPM and CONFIG_SHA1.
1344 At the moment only the UHCI host controller is
1345 supported (PIP405, MIP405, MPC5200); define
1346 CONFIG_USB_UHCI to enable it.
1347 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1348 and define CONFIG_USB_STORAGE to enable the USB
1351 Supported are USB Keyboards and USB Floppy drives
1353 MPC5200 USB requires additional defines:
1355 for 528 MHz Clock: 0x0001bbbb
1359 for differential drivers: 0x00001000
1360 for single ended drivers: 0x00005000
1361 for differential drivers on PSC3: 0x00000100
1362 for single ended drivers on PSC3: 0x00004100
1363 CONFIG_SYS_USB_EVENT_POLL
1364 May be defined to allow interrupt polling
1365 instead of using asynchronous interrupts
1367 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1368 txfilltuning field in the EHCI controller on reset.
1370 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1371 interval for usb hub power-on delay.(minimum 100msec)
1374 Define the below if you wish to use the USB console.
1375 Once firmware is rebuilt from a serial console issue the
1376 command "setenv stdin usbtty; setenv stdout usbtty" and
1377 attach your USB cable. The Unix command "dmesg" should print
1378 it has found a new device. The environment variable usbtty
1379 can be set to gserial or cdc_acm to enable your device to
1380 appear to a USB host as a Linux gserial device or a
1381 Common Device Class Abstract Control Model serial device.
1382 If you select usbtty = gserial you should be able to enumerate
1384 # modprobe usbserial vendor=0xVendorID product=0xProductID
1385 else if using cdc_acm, simply setting the environment
1386 variable usbtty to be cdc_acm should suffice. The following
1387 might be defined in YourBoardName.h
1390 Define this to build a UDC device
1393 Define this to have a tty type of device available to
1394 talk to the UDC device
1397 Define this to enable the high speed support for usb
1398 device and usbtty. If this feature is enabled, a routine
1399 int is_usbd_high_speed(void)
1400 also needs to be defined by the driver to dynamically poll
1401 whether the enumeration has succeded at high speed or full
1404 CONFIG_SYS_CONSOLE_IS_IN_ENV
1405 Define this if you want stdin, stdout &/or stderr to
1409 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1410 Derive USB clock from external clock "blah"
1411 - CONFIG_SYS_USB_EXTC_CLK 0x02
1413 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1414 Derive USB clock from brgclk
1415 - CONFIG_SYS_USB_BRG_CLK 0x04
1417 If you have a USB-IF assigned VendorID then you may wish to
1418 define your own vendor specific values either in BoardName.h
1419 or directly in usbd_vendor_info.h. If you don't define
1420 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1421 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1422 should pretend to be a Linux device to it's target host.
1424 CONFIG_USBD_MANUFACTURER
1425 Define this string as the name of your company for
1426 - CONFIG_USBD_MANUFACTURER "my company"
1428 CONFIG_USBD_PRODUCT_NAME
1429 Define this string as the name of your product
1430 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1432 CONFIG_USBD_VENDORID
1433 Define this as your assigned Vendor ID from the USB
1434 Implementors Forum. This *must* be a genuine Vendor ID
1435 to avoid polluting the USB namespace.
1436 - CONFIG_USBD_VENDORID 0xFFFF
1438 CONFIG_USBD_PRODUCTID
1439 Define this as the unique Product ID
1441 - CONFIG_USBD_PRODUCTID 0xFFFF
1443 Some USB device drivers may need to check USB cable attachment.
1444 In this case you can enable following config in BoardName.h:
1445 CONFIG_USB_CABLE_CHECK
1446 This enables function definition:
1447 - usb_cable_connected() in include/usb.h
1448 Implementation of this function is board-specific.
1450 - ULPI Layer Support:
1451 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1452 the generic ULPI layer. The generic layer accesses the ULPI PHY
1453 via the platform viewport, so you need both the genric layer and
1454 the viewport enabled. Currently only Chipidea/ARC based
1455 viewport is supported.
1456 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1457 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1458 If your ULPI phy needs a different reference clock than the
1459 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1460 the appropriate value in Hz.
1463 The MMC controller on the Intel PXA is supported. To
1464 enable this define CONFIG_MMC. The MMC can be
1465 accessed from the boot prompt by mapping the device
1466 to physical memory similar to flash. Command line is
1467 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1468 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1471 Support for Renesas on-chip MMCIF controller
1473 CONFIG_SH_MMCIF_ADDR
1474 Define the base address of MMCIF registers
1477 Define the clock frequency for MMCIF
1479 - USB Device Firmware Update (DFU) class support:
1481 This enables the USB portion of the DFU USB class
1484 This enables the command "dfu" which is used to have
1485 U-Boot create a DFU class device via USB. This command
1486 requires that the "dfu_alt_info" environment variable be
1487 set and define the alt settings to expose to the host.
1490 This enables support for exposing (e)MMC devices via DFU.
1493 This enables support for exposing NAND devices via DFU.
1496 This enables support for exposing RAM via DFU.
1497 Note: DFU spec refer to non-volatile memory usage, but
1498 allow usages beyond the scope of spec - here RAM usage,
1499 one that would help mostly the developer.
1501 CONFIG_SYS_DFU_DATA_BUF_SIZE
1502 Dfu transfer uses a buffer before writing data to the
1503 raw storage device. Make the size (in bytes) of this buffer
1504 configurable. The size of this buffer is also configurable
1505 through the "dfu_bufsiz" environment variable.
1507 CONFIG_SYS_DFU_MAX_FILE_SIZE
1508 When updating files rather than the raw storage device,
1509 we use a static buffer to copy the file into and then write
1510 the buffer once we've been given the whole file. Define
1511 this to the maximum filesize (in bytes) for the buffer.
1512 Default is 4 MiB if undefined.
1514 - Journaling Flash filesystem support:
1515 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1516 CONFIG_JFFS2_NAND_DEV
1517 Define these for a default partition on a NAND device
1519 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1520 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1521 Define these for a default partition on a NOR device
1523 CONFIG_SYS_JFFS_CUSTOM_PART
1524 Define this to create an own partition. You have to provide a
1525 function struct part_info* jffs2_part_info(int part_num)
1527 If you define only one JFFS2 partition you may also want to
1528 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1529 to disable the command chpart. This is the default when you
1530 have not defined a custom partition
1532 - FAT(File Allocation Table) filesystem write function support:
1535 Define this to enable support for saving memory data as a
1536 file in FAT formatted partition.
1538 This will also enable the command "fatwrite" enabling the
1539 user to write files to FAT.
1541 CBFS (Coreboot Filesystem) support
1544 Define this to enable support for reading from a Coreboot
1545 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1551 Define this to enable standard (PC-Style) keyboard
1555 Standard PC keyboard driver with US (is default) and
1556 GERMAN key layout (switch via environment 'keymap=de') support.
1557 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1558 for cfb_console. Supports cursor blinking.
1561 Enables a Chrome OS keyboard using the CROS_EC interface.
1562 This uses CROS_EC to communicate with a second microcontroller
1563 which provides key scans on request.
1568 Define this to enable video support (for output to
1571 CONFIG_VIDEO_CT69000
1573 Enable Chips & Technologies 69000 Video chip
1575 CONFIG_VIDEO_SMI_LYNXEM
1576 Enable Silicon Motion SMI 712/710/810 Video chip. The
1577 video output is selected via environment 'videoout'
1578 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1581 For the CT69000 and SMI_LYNXEM drivers, videomode is
1582 selected via environment 'videomode'. Two different ways
1584 - "videomode=num" 'num' is a standard LiLo mode numbers.
1585 Following standard modes are supported (* is default):
1587 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1588 -------------+---------------------------------------------
1589 8 bits | 0x301* 0x303 0x305 0x161 0x307
1590 15 bits | 0x310 0x313 0x316 0x162 0x319
1591 16 bits | 0x311 0x314 0x317 0x163 0x31A
1592 24 bits | 0x312 0x315 0x318 ? 0x31B
1593 -------------+---------------------------------------------
1594 (i.e. setenv videomode 317; saveenv; reset;)
1596 - "videomode=bootargs" all the video parameters are parsed
1597 from the bootargs. (See drivers/video/videomodes.c)
1600 CONFIG_VIDEO_SED13806
1601 Enable Epson SED13806 driver. This driver supports 8bpp
1602 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1603 or CONFIG_VIDEO_SED13806_16BPP
1606 Enable the Freescale DIU video driver. Reference boards for
1607 SOCs that have a DIU should define this macro to enable DIU
1608 support, and should also define these other macros:
1614 CONFIG_VIDEO_SW_CURSOR
1615 CONFIG_VGA_AS_SINGLE_DEVICE
1617 CONFIG_VIDEO_BMP_LOGO
1619 The DIU driver will look for the 'video-mode' environment
1620 variable, and if defined, enable the DIU as a console during
1621 boot. See the documentation file README.video for a
1622 description of this variable.
1626 Enable the VGA video / BIOS for x86. The alternative if you
1627 are using coreboot is to use the coreboot frame buffer
1634 Define this to enable a custom keyboard support.
1635 This simply calls drv_keyboard_init() which must be
1636 defined in your board-specific files.
1637 The only board using this so far is RBC823.
1639 - LCD Support: CONFIG_LCD
1641 Define this to enable LCD support (for output to LCD
1642 display); also select one of the supported displays
1643 by defining one of these:
1647 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1649 CONFIG_NEC_NL6448AC33:
1651 NEC NL6448AC33-18. Active, color, single scan.
1653 CONFIG_NEC_NL6448BC20
1655 NEC NL6448BC20-08. 6.5", 640x480.
1656 Active, color, single scan.
1658 CONFIG_NEC_NL6448BC33_54
1660 NEC NL6448BC33-54. 10.4", 640x480.
1661 Active, color, single scan.
1665 Sharp 320x240. Active, color, single scan.
1666 It isn't 16x9, and I am not sure what it is.
1668 CONFIG_SHARP_LQ64D341
1670 Sharp LQ64D341 display, 640x480.
1671 Active, color, single scan.
1675 HLD1045 display, 640x480.
1676 Active, color, single scan.
1680 Optrex CBL50840-2 NF-FW 99 22 M5
1682 Hitachi LMG6912RPFC-00T
1686 320x240. Black & white.
1688 Normally display is black on white background; define
1689 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1691 CONFIG_LCD_ALIGNMENT
1693 Normally the LCD is page-aligned (tyically 4KB). If this is
1694 defined then the LCD will be aligned to this value instead.
1695 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1696 here, since it is cheaper to change data cache settings on
1697 a per-section basis.
1699 CONFIG_CONSOLE_SCROLL_LINES
1701 When the console need to be scrolled, this is the number of
1702 lines to scroll by. It defaults to 1. Increasing this makes
1703 the console jump but can help speed up operation when scrolling
1708 Support drawing of RLE8-compressed bitmaps on the LCD.
1712 Enables an 'i2c edid' command which can read EDID
1713 information over I2C from an attached LCD display.
1715 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1717 If this option is set, the environment is checked for
1718 a variable "splashimage". If found, the usual display
1719 of logo, copyright and system information on the LCD
1720 is suppressed and the BMP image at the address
1721 specified in "splashimage" is loaded instead. The
1722 console is redirected to the "nulldev", too. This
1723 allows for a "silent" boot where a splash screen is
1724 loaded very quickly after power-on.
1726 CONFIG_SPLASHIMAGE_GUARD
1728 If this option is set, then U-Boot will prevent the environment
1729 variable "splashimage" from being set to a problematic address
1730 (see README.displaying-bmps and README.arm-unaligned-accesses).
1731 This option is useful for targets where, due to alignment
1732 restrictions, an improperly aligned BMP image will cause a data
1733 abort. If you think you will not have problems with unaligned
1734 accesses (for example because your toolchain prevents them)
1735 there is no need to set this option.
1737 CONFIG_SPLASH_SCREEN_ALIGN
1739 If this option is set the splash image can be freely positioned
1740 on the screen. Environment variable "splashpos" specifies the
1741 position as "x,y". If a positive number is given it is used as
1742 number of pixel from left/top. If a negative number is given it
1743 is used as number of pixel from right/bottom. You can also
1744 specify 'm' for centering the image.
1747 setenv splashpos m,m
1748 => image at center of screen
1750 setenv splashpos 30,20
1751 => image at x = 30 and y = 20
1753 setenv splashpos -10,m
1754 => vertically centered image
1755 at x = dspWidth - bmpWidth - 9
1757 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1759 If this option is set, additionally to standard BMP
1760 images, gzipped BMP images can be displayed via the
1761 splashscreen support or the bmp command.
1763 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1765 If this option is set, 8-bit RLE compressed BMP images
1766 can be displayed via the splashscreen support or the
1769 - Do compresssing for memory range:
1772 If this option is set, it would use zlib deflate method
1773 to compress the specified memory at its best effort.
1775 - Compression support:
1778 Enabled by default to support gzip compressed images.
1782 If this option is set, support for bzip2 compressed
1783 images is included. If not, only uncompressed and gzip
1784 compressed images are supported.
1786 NOTE: the bzip2 algorithm requires a lot of RAM, so
1787 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1792 If this option is set, support for lzma compressed
1795 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1796 requires an amount of dynamic memory that is given by the
1799 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1801 Where lc and lp stand for, respectively, Literal context bits
1802 and Literal pos bits.
1804 This value is upper-bounded by 14MB in the worst case. Anyway,
1805 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1806 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1807 a very small buffer.
1809 Use the lzmainfo tool to determinate the lc and lp values and
1810 then calculate the amount of needed dynamic memory (ensuring
1811 the appropriate CONFIG_SYS_MALLOC_LEN value).
1815 If this option is set, support for LZO compressed images
1821 The address of PHY on MII bus.
1823 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1825 The clock frequency of the MII bus
1829 If this option is set, support for speed/duplex
1830 detection of gigabit PHY is included.
1832 CONFIG_PHY_RESET_DELAY
1834 Some PHY like Intel LXT971A need extra delay after
1835 reset before any MII register access is possible.
1836 For such PHY, set this option to the usec delay
1837 required. (minimum 300usec for LXT971A)
1839 CONFIG_PHY_CMD_DELAY (ppc4xx)
1841 Some PHY like Intel LXT971A need extra delay after
1842 command issued before MII status register can be read
1852 Define a default value for Ethernet address to use
1853 for the respective Ethernet interface, in case this
1854 is not determined automatically.
1859 Define a default value for the IP address to use for
1860 the default Ethernet interface, in case this is not
1861 determined through e.g. bootp.
1862 (Environment variable "ipaddr")
1864 - Server IP address:
1867 Defines a default value for the IP address of a TFTP
1868 server to contact when using the "tftboot" command.
1869 (Environment variable "serverip")
1871 CONFIG_KEEP_SERVERADDR
1873 Keeps the server's MAC address, in the env 'serveraddr'
1874 for passing to bootargs (like Linux's netconsole option)
1876 - Gateway IP address:
1879 Defines a default value for the IP address of the
1880 default router where packets to other networks are
1882 (Environment variable "gatewayip")
1887 Defines a default value for the subnet mask (or
1888 routing prefix) which is used to determine if an IP
1889 address belongs to the local subnet or needs to be
1890 forwarded through a router.
1891 (Environment variable "netmask")
1893 - Multicast TFTP Mode:
1896 Defines whether you want to support multicast TFTP as per
1897 rfc-2090; for example to work with atftp. Lets lots of targets
1898 tftp down the same boot image concurrently. Note: the Ethernet
1899 driver in use must provide a function: mcast() to join/leave a
1902 - BOOTP Recovery Mode:
1903 CONFIG_BOOTP_RANDOM_DELAY
1905 If you have many targets in a network that try to
1906 boot using BOOTP, you may want to avoid that all
1907 systems send out BOOTP requests at precisely the same
1908 moment (which would happen for instance at recovery
1909 from a power failure, when all systems will try to
1910 boot, thus flooding the BOOTP server. Defining
1911 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1912 inserted before sending out BOOTP requests. The
1913 following delays are inserted then:
1915 1st BOOTP request: delay 0 ... 1 sec
1916 2nd BOOTP request: delay 0 ... 2 sec
1917 3rd BOOTP request: delay 0 ... 4 sec
1919 BOOTP requests: delay 0 ... 8 sec
1921 - DHCP Advanced Options:
1922 You can fine tune the DHCP functionality by defining
1923 CONFIG_BOOTP_* symbols:
1925 CONFIG_BOOTP_SUBNETMASK
1926 CONFIG_BOOTP_GATEWAY
1927 CONFIG_BOOTP_HOSTNAME
1928 CONFIG_BOOTP_NISDOMAIN
1929 CONFIG_BOOTP_BOOTPATH
1930 CONFIG_BOOTP_BOOTFILESIZE
1933 CONFIG_BOOTP_SEND_HOSTNAME
1934 CONFIG_BOOTP_NTPSERVER
1935 CONFIG_BOOTP_TIMEOFFSET
1936 CONFIG_BOOTP_VENDOREX
1937 CONFIG_BOOTP_MAY_FAIL
1939 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1940 environment variable, not the BOOTP server.
1942 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1943 after the configured retry count, the call will fail
1944 instead of starting over. This can be used to fail over
1945 to Link-local IP address configuration if the DHCP server
1948 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1949 serverip from a DHCP server, it is possible that more
1950 than one DNS serverip is offered to the client.
1951 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1952 serverip will be stored in the additional environment
1953 variable "dnsip2". The first DNS serverip is always
1954 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1957 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1958 to do a dynamic update of a DNS server. To do this, they
1959 need the hostname of the DHCP requester.
1960 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1961 of the "hostname" environment variable is passed as
1962 option 12 to the DHCP server.
1964 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1966 A 32bit value in microseconds for a delay between
1967 receiving a "DHCP Offer" and sending the "DHCP Request".
1968 This fixes a problem with certain DHCP servers that don't
1969 respond 100% of the time to a "DHCP request". E.g. On an
1970 AT91RM9200 processor running at 180MHz, this delay needed
1971 to be *at least* 15,000 usec before a Windows Server 2003
1972 DHCP server would reply 100% of the time. I recommend at
1973 least 50,000 usec to be safe. The alternative is to hope
1974 that one of the retries will be successful but note that
1975 the DHCP timeout and retry process takes a longer than
1978 - Link-local IP address negotiation:
1979 Negotiate with other link-local clients on the local network
1980 for an address that doesn't require explicit configuration.
1981 This is especially useful if a DHCP server cannot be guaranteed
1982 to exist in all environments that the device must operate.
1984 See doc/README.link-local for more information.
1987 CONFIG_CDP_DEVICE_ID
1989 The device id used in CDP trigger frames.
1991 CONFIG_CDP_DEVICE_ID_PREFIX
1993 A two character string which is prefixed to the MAC address
1998 A printf format string which contains the ascii name of
1999 the port. Normally is set to "eth%d" which sets
2000 eth0 for the first Ethernet, eth1 for the second etc.
2002 CONFIG_CDP_CAPABILITIES
2004 A 32bit integer which indicates the device capabilities;
2005 0x00000010 for a normal host which does not forwards.
2009 An ascii string containing the version of the software.
2013 An ascii string containing the name of the platform.
2017 A 32bit integer sent on the trigger.
2019 CONFIG_CDP_POWER_CONSUMPTION
2021 A 16bit integer containing the power consumption of the
2022 device in .1 of milliwatts.
2024 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2026 A byte containing the id of the VLAN.
2028 - Status LED: CONFIG_STATUS_LED
2030 Several configurations allow to display the current
2031 status using a LED. For instance, the LED will blink
2032 fast while running U-Boot code, stop blinking as
2033 soon as a reply to a BOOTP request was received, and
2034 start blinking slow once the Linux kernel is running
2035 (supported by a status LED driver in the Linux
2036 kernel). Defining CONFIG_STATUS_LED enables this
2042 The status LED can be connected to a GPIO pin.
2043 In such cases, the gpio_led driver can be used as a
2044 status LED backend implementation. Define CONFIG_GPIO_LED
2045 to include the gpio_led driver in the U-Boot binary.
2047 CONFIG_GPIO_LED_INVERTED_TABLE
2048 Some GPIO connected LEDs may have inverted polarity in which
2049 case the GPIO high value corresponds to LED off state and
2050 GPIO low value corresponds to LED on state.
2051 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2052 with a list of GPIO LEDs that have inverted polarity.
2054 - CAN Support: CONFIG_CAN_DRIVER
2056 Defining CONFIG_CAN_DRIVER enables CAN driver support
2057 on those systems that support this (optional)
2058 feature, like the TQM8xxL modules.
2060 - I2C Support: CONFIG_SYS_I2C
2062 This enable the NEW i2c subsystem, and will allow you to use
2063 i2c commands at the u-boot command line (as long as you set
2064 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2065 based realtime clock chips or other i2c devices. See
2066 common/cmd_i2c.c for a description of the command line
2069 ported i2c driver to the new framework:
2070 - drivers/i2c/soft_i2c.c:
2071 - activate first bus with CONFIG_SYS_I2C_SOFT define
2072 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2073 for defining speed and slave address
2074 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2075 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2076 for defining speed and slave address
2077 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2078 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2079 for defining speed and slave address
2080 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2081 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2082 for defining speed and slave address
2084 - drivers/i2c/fsl_i2c.c:
2085 - activate i2c driver with CONFIG_SYS_I2C_FSL
2086 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2087 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2088 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2090 - If your board supports a second fsl i2c bus, define
2091 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2092 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2093 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2096 - drivers/i2c/tegra_i2c.c:
2097 - activate this driver with CONFIG_SYS_I2C_TEGRA
2098 - This driver adds 4 i2c buses with a fix speed from
2099 100000 and the slave addr 0!
2101 - drivers/i2c/ppc4xx_i2c.c
2102 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2103 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2104 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2106 - drivers/i2c/i2c_mxc.c
2107 - activate this driver with CONFIG_SYS_I2C_MXC
2108 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2109 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2110 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2111 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2112 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2113 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2114 If thoses defines are not set, default value is 100000
2115 for speed, and 0 for slave.
2117 - drivers/i2c/rcar_i2c.c:
2118 - activate this driver with CONFIG_SYS_I2C_RCAR
2119 - This driver adds 4 i2c buses
2121 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2122 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2123 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2124 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2125 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2126 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2127 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2128 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2129 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2131 - drivers/i2c/sh_i2c.c:
2132 - activate this driver with CONFIG_SYS_I2C_SH
2133 - This driver adds from 2 to 5 i2c buses
2135 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2136 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2137 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2138 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2139 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2140 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2141 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2142 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2143 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2144 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2145 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2146 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2147 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2149 - drivers/i2c/omap24xx_i2c.c
2150 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2151 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2152 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2153 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2154 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2155 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2156 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2157 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2158 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2159 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2160 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2162 - drivers/i2c/zynq_i2c.c
2163 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2164 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2165 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2167 - drivers/i2c/s3c24x0_i2c.c:
2168 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2169 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2170 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2171 with a fix speed from 100000 and the slave addr 0!
2175 CONFIG_SYS_NUM_I2C_BUSES
2176 Hold the number of i2c busses you want to use. If you
2177 don't use/have i2c muxes on your i2c bus, this
2178 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2181 CONFIG_SYS_I2C_DIRECT_BUS
2182 define this, if you don't use i2c muxes on your hardware.
2183 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2186 CONFIG_SYS_I2C_MAX_HOPS
2187 define how many muxes are maximal consecutively connected
2188 on one i2c bus. If you not use i2c muxes, omit this
2191 CONFIG_SYS_I2C_BUSES
2192 hold a list of busses you want to use, only used if
2193 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2194 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2195 CONFIG_SYS_NUM_I2C_BUSES = 9:
2197 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2198 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2199 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2200 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2201 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2202 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2203 {1, {I2C_NULL_HOP}}, \
2204 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2205 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2209 bus 0 on adapter 0 without a mux
2210 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2211 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2212 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2213 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2214 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2215 bus 6 on adapter 1 without a mux
2216 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2217 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2219 If you do not have i2c muxes on your board, omit this define.
2221 - Legacy I2C Support: CONFIG_HARD_I2C
2223 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2224 provides the following compelling advantages:
2226 - more than one i2c adapter is usable
2227 - approved multibus support
2228 - better i2c mux support
2230 ** Please consider updating your I2C driver now. **
2232 These enable legacy I2C serial bus commands. Defining
2233 CONFIG_HARD_I2C will include the appropriate I2C driver
2234 for the selected CPU.
2236 This will allow you to use i2c commands at the u-boot
2237 command line (as long as you set CONFIG_CMD_I2C in
2238 CONFIG_COMMANDS) and communicate with i2c based realtime
2239 clock chips. See common/cmd_i2c.c for a description of the
2240 command line interface.
2242 CONFIG_HARD_I2C selects a hardware I2C controller.
2244 There are several other quantities that must also be
2245 defined when you define CONFIG_HARD_I2C.
2247 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2248 to be the frequency (in Hz) at which you wish your i2c bus
2249 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2250 the CPU's i2c node address).
2252 Now, the u-boot i2c code for the mpc8xx
2253 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2254 and so its address should therefore be cleared to 0 (See,
2255 eg, MPC823e User's Manual p.16-473). So, set
2256 CONFIG_SYS_I2C_SLAVE to 0.
2258 CONFIG_SYS_I2C_INIT_MPC5XXX
2260 When a board is reset during an i2c bus transfer
2261 chips might think that the current transfer is still
2262 in progress. Reset the slave devices by sending start
2263 commands until the slave device responds.
2265 That's all that's required for CONFIG_HARD_I2C.
2267 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2268 then the following macros need to be defined (examples are
2269 from include/configs/lwmon.h):
2273 (Optional). Any commands necessary to enable the I2C
2274 controller or configure ports.
2276 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2280 (Only for MPC8260 CPU). The I/O port to use (the code
2281 assumes both bits are on the same port). Valid values
2282 are 0..3 for ports A..D.
2286 The code necessary to make the I2C data line active
2287 (driven). If the data line is open collector, this
2290 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2294 The code necessary to make the I2C data line tri-stated
2295 (inactive). If the data line is open collector, this
2298 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2302 Code that returns true if the I2C data line is high,
2305 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2309 If <bit> is true, sets the I2C data line high. If it
2310 is false, it clears it (low).
2312 eg: #define I2C_SDA(bit) \
2313 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2314 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2318 If <bit> is true, sets the I2C clock line high. If it
2319 is false, it clears it (low).
2321 eg: #define I2C_SCL(bit) \
2322 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2323 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2327 This delay is invoked four times per clock cycle so this
2328 controls the rate of data transfer. The data rate thus
2329 is 1 / (I2C_DELAY * 4). Often defined to be something
2332 #define I2C_DELAY udelay(2)
2334 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2336 If your arch supports the generic GPIO framework (asm/gpio.h),
2337 then you may alternatively define the two GPIOs that are to be
2338 used as SCL / SDA. Any of the previous I2C_xxx macros will
2339 have GPIO-based defaults assigned to them as appropriate.
2341 You should define these to the GPIO value as given directly to
2342 the generic GPIO functions.
2344 CONFIG_SYS_I2C_INIT_BOARD
2346 When a board is reset during an i2c bus transfer
2347 chips might think that the current transfer is still
2348 in progress. On some boards it is possible to access
2349 the i2c SCLK line directly, either by using the
2350 processor pin as a GPIO or by having a second pin
2351 connected to the bus. If this option is defined a
2352 custom i2c_init_board() routine in boards/xxx/board.c
2353 is run early in the boot sequence.
2355 CONFIG_SYS_I2C_BOARD_LATE_INIT
2357 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2358 defined a custom i2c_board_late_init() routine in
2359 boards/xxx/board.c is run AFTER the operations in i2c_init()
2360 is completed. This callpoint can be used to unreset i2c bus
2361 using CPU i2c controller register accesses for CPUs whose i2c
2362 controller provide such a method. It is called at the end of
2363 i2c_init() to allow i2c_init operations to setup the i2c bus
2364 controller on the CPU (e.g. setting bus speed & slave address).
2366 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2368 This option enables configuration of bi_iic_fast[] flags
2369 in u-boot bd_info structure based on u-boot environment
2370 variable "i2cfast". (see also i2cfast)
2372 CONFIG_I2C_MULTI_BUS
2374 This option allows the use of multiple I2C buses, each of which
2375 must have a controller. At any point in time, only one bus is
2376 active. To switch to a different bus, use the 'i2c dev' command.
2377 Note that bus numbering is zero-based.
2379 CONFIG_SYS_I2C_NOPROBES
2381 This option specifies a list of I2C devices that will be skipped
2382 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2383 is set, specify a list of bus-device pairs. Otherwise, specify
2384 a 1D array of device addresses
2387 #undef CONFIG_I2C_MULTI_BUS
2388 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2390 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2392 #define CONFIG_I2C_MULTI_BUS
2393 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2395 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2397 CONFIG_SYS_SPD_BUS_NUM
2399 If defined, then this indicates the I2C bus number for DDR SPD.
2400 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2402 CONFIG_SYS_RTC_BUS_NUM
2404 If defined, then this indicates the I2C bus number for the RTC.
2405 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2407 CONFIG_SYS_DTT_BUS_NUM
2409 If defined, then this indicates the I2C bus number for the DTT.
2410 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2412 CONFIG_SYS_I2C_DTT_ADDR:
2414 If defined, specifies the I2C address of the DTT device.
2415 If not defined, then U-Boot uses predefined value for
2416 specified DTT device.
2418 CONFIG_SOFT_I2C_READ_REPEATED_START
2420 defining this will force the i2c_read() function in
2421 the soft_i2c driver to perform an I2C repeated start
2422 between writing the address pointer and reading the
2423 data. If this define is omitted the default behaviour
2424 of doing a stop-start sequence will be used. Most I2C
2425 devices can use either method, but some require one or
2428 - SPI Support: CONFIG_SPI
2430 Enables SPI driver (so far only tested with
2431 SPI EEPROM, also an instance works with Crystal A/D and
2432 D/As on the SACSng board)
2436 Enables the driver for SPI controller on SuperH. Currently
2437 only SH7757 is supported.
2441 Enables extended (16-bit) SPI EEPROM addressing.
2442 (symmetrical to CONFIG_I2C_X)
2446 Enables a software (bit-bang) SPI driver rather than
2447 using hardware support. This is a general purpose
2448 driver that only requires three general I/O port pins
2449 (two outputs, one input) to function. If this is
2450 defined, the board configuration must define several
2451 SPI configuration items (port pins to use, etc). For
2452 an example, see include/configs/sacsng.h.
2456 Enables a hardware SPI driver for general-purpose reads
2457 and writes. As with CONFIG_SOFT_SPI, the board configuration
2458 must define a list of chip-select function pointers.
2459 Currently supported on some MPC8xxx processors. For an
2460 example, see include/configs/mpc8349emds.h.
2464 Enables the driver for the SPI controllers on i.MX and MXC
2465 SoCs. Currently i.MX31/35/51 are supported.
2467 - FPGA Support: CONFIG_FPGA
2469 Enables FPGA subsystem.
2471 CONFIG_FPGA_<vendor>
2473 Enables support for specific chip vendors.
2476 CONFIG_FPGA_<family>
2478 Enables support for FPGA family.
2479 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2483 Specify the number of FPGA devices to support.
2485 CONFIG_SYS_FPGA_PROG_FEEDBACK
2487 Enable printing of hash marks during FPGA configuration.
2489 CONFIG_SYS_FPGA_CHECK_BUSY
2491 Enable checks on FPGA configuration interface busy
2492 status by the configuration function. This option
2493 will require a board or device specific function to
2498 If defined, a function that provides delays in the FPGA
2499 configuration driver.
2501 CONFIG_SYS_FPGA_CHECK_CTRLC
2502 Allow Control-C to interrupt FPGA configuration
2504 CONFIG_SYS_FPGA_CHECK_ERROR
2506 Check for configuration errors during FPGA bitfile
2507 loading. For example, abort during Virtex II
2508 configuration if the INIT_B line goes low (which
2509 indicated a CRC error).
2511 CONFIG_SYS_FPGA_WAIT_INIT
2513 Maximum time to wait for the INIT_B line to deassert
2514 after PROB_B has been deasserted during a Virtex II
2515 FPGA configuration sequence. The default time is 500
2518 CONFIG_SYS_FPGA_WAIT_BUSY
2520 Maximum time to wait for BUSY to deassert during
2521 Virtex II FPGA configuration. The default is 5 ms.
2523 CONFIG_SYS_FPGA_WAIT_CONFIG
2525 Time to wait after FPGA configuration. The default is
2528 - Configuration Management:
2531 If defined, this string will be added to the U-Boot
2532 version information (U_BOOT_VERSION)
2534 - Vendor Parameter Protection:
2536 U-Boot considers the values of the environment
2537 variables "serial#" (Board Serial Number) and
2538 "ethaddr" (Ethernet Address) to be parameters that
2539 are set once by the board vendor / manufacturer, and
2540 protects these variables from casual modification by
2541 the user. Once set, these variables are read-only,
2542 and write or delete attempts are rejected. You can
2543 change this behaviour:
2545 If CONFIG_ENV_OVERWRITE is #defined in your config
2546 file, the write protection for vendor parameters is
2547 completely disabled. Anybody can change or delete
2550 Alternatively, if you #define _both_ CONFIG_ETHADDR
2551 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2552 Ethernet address is installed in the environment,
2553 which can be changed exactly ONCE by the user. [The
2554 serial# is unaffected by this, i. e. it remains
2557 The same can be accomplished in a more flexible way
2558 for any variable by configuring the type of access
2559 to allow for those variables in the ".flags" variable
2560 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2565 Define this variable to enable the reservation of
2566 "protected RAM", i. e. RAM which is not overwritten
2567 by U-Boot. Define CONFIG_PRAM to hold the number of
2568 kB you want to reserve for pRAM. You can overwrite
2569 this default value by defining an environment
2570 variable "pram" to the number of kB you want to
2571 reserve. Note that the board info structure will
2572 still show the full amount of RAM. If pRAM is
2573 reserved, a new environment variable "mem" will
2574 automatically be defined to hold the amount of
2575 remaining RAM in a form that can be passed as boot
2576 argument to Linux, for instance like that:
2578 setenv bootargs ... mem=\${mem}
2581 This way you can tell Linux not to use this memory,
2582 either, which results in a memory region that will
2583 not be affected by reboots.
2585 *WARNING* If your board configuration uses automatic
2586 detection of the RAM size, you must make sure that
2587 this memory test is non-destructive. So far, the
2588 following board configurations are known to be
2591 IVMS8, IVML24, SPD8xx, TQM8xxL,
2592 HERMES, IP860, RPXlite, LWMON,
2595 - Access to physical memory region (> 4GB)
2596 Some basic support is provided for operations on memory not
2597 normally accessible to U-Boot - e.g. some architectures
2598 support access to more than 4GB of memory on 32-bit
2599 machines using physical address extension or similar.
2600 Define CONFIG_PHYSMEM to access this basic support, which
2601 currently only supports clearing the memory.
2606 Define this variable to stop the system in case of a
2607 fatal error, so that you have to reset it manually.
2608 This is probably NOT a good idea for an embedded
2609 system where you want the system to reboot
2610 automatically as fast as possible, but it may be
2611 useful during development since you can try to debug
2612 the conditions that lead to the situation.
2614 CONFIG_NET_RETRY_COUNT
2616 This variable defines the number of retries for
2617 network operations like ARP, RARP, TFTP, or BOOTP
2618 before giving up the operation. If not defined, a
2619 default value of 5 is used.
2623 Timeout waiting for an ARP reply in milliseconds.
2627 Timeout in milliseconds used in NFS protocol.
2628 If you encounter "ERROR: Cannot umount" in nfs command,
2629 try longer timeout such as
2630 #define CONFIG_NFS_TIMEOUT 10000UL
2632 - Command Interpreter:
2633 CONFIG_AUTO_COMPLETE
2635 Enable auto completion of commands using TAB.
2637 Note that this feature has NOT been implemented yet
2638 for the "hush" shell.
2641 CONFIG_SYS_HUSH_PARSER
2643 Define this variable to enable the "hush" shell (from
2644 Busybox) as command line interpreter, thus enabling
2645 powerful command line syntax like
2646 if...then...else...fi conditionals or `&&' and '||'
2647 constructs ("shell scripts").
2649 If undefined, you get the old, much simpler behaviour
2650 with a somewhat smaller memory footprint.
2653 CONFIG_SYS_PROMPT_HUSH_PS2
2655 This defines the secondary prompt string, which is
2656 printed when the command interpreter needs more input
2657 to complete a command. Usually "> ".
2661 In the current implementation, the local variables
2662 space and global environment variables space are
2663 separated. Local variables are those you define by
2664 simply typing `name=value'. To access a local
2665 variable later on, you have write `$name' or
2666 `${name}'; to execute the contents of a variable
2667 directly type `$name' at the command prompt.
2669 Global environment variables are those you use
2670 setenv/printenv to work with. To run a command stored
2671 in such a variable, you need to use the run command,
2672 and you must not use the '$' sign to access them.
2674 To store commands and special characters in a
2675 variable, please use double quotation marks
2676 surrounding the whole text of the variable, instead
2677 of the backslashes before semicolons and special
2680 - Commandline Editing and History:
2681 CONFIG_CMDLINE_EDITING
2683 Enable editing and History functions for interactive
2684 commandline input operations
2686 - Default Environment:
2687 CONFIG_EXTRA_ENV_SETTINGS
2689 Define this to contain any number of null terminated
2690 strings (variable = value pairs) that will be part of
2691 the default environment compiled into the boot image.
2693 For example, place something like this in your
2694 board's config file:
2696 #define CONFIG_EXTRA_ENV_SETTINGS \
2700 Warning: This method is based on knowledge about the
2701 internal format how the environment is stored by the
2702 U-Boot code. This is NOT an official, exported
2703 interface! Although it is unlikely that this format
2704 will change soon, there is no guarantee either.
2705 You better know what you are doing here.
2707 Note: overly (ab)use of the default environment is
2708 discouraged. Make sure to check other ways to preset
2709 the environment like the "source" command or the
2712 CONFIG_ENV_VARS_UBOOT_CONFIG
2714 Define this in order to add variables describing the
2715 U-Boot build configuration to the default environment.
2716 These will be named arch, cpu, board, vendor, and soc.
2718 Enabling this option will cause the following to be defined:
2726 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2728 Define this in order to add variables describing certain
2729 run-time determined information about the hardware to the
2730 environment. These will be named board_name, board_rev.
2732 CONFIG_DELAY_ENVIRONMENT
2734 Normally the environment is loaded when the board is
2735 intialised so that it is available to U-Boot. This inhibits
2736 that so that the environment is not available until
2737 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2738 this is instead controlled by the value of
2739 /config/load-environment.
2741 - DataFlash Support:
2742 CONFIG_HAS_DATAFLASH
2744 Defining this option enables DataFlash features and
2745 allows to read/write in Dataflash via the standard
2748 - Serial Flash support
2751 Defining this option enables SPI flash commands
2752 'sf probe/read/write/erase/update'.
2754 Usage requires an initial 'probe' to define the serial
2755 flash parameters, followed by read/write/erase/update
2758 The following defaults may be provided by the platform
2759 to handle the common case when only a single serial
2760 flash is present on the system.
2762 CONFIG_SF_DEFAULT_BUS Bus identifier
2763 CONFIG_SF_DEFAULT_CS Chip-select
2764 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2765 CONFIG_SF_DEFAULT_SPEED in Hz
2769 Define this option to include a destructive SPI flash
2772 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2774 Define this option to use the Bank addr/Extended addr
2775 support on SPI flashes which has size > 16Mbytes.
2777 CONFIG_SF_DUAL_FLASH Dual flash memories
2779 Define this option to use dual flash support where two flash
2780 memories can be connected with a given cs line.
2781 currently Xilinx Zynq qspi support these type of connections.
2783 - SystemACE Support:
2786 Adding this option adds support for Xilinx SystemACE
2787 chips attached via some sort of local bus. The address
2788 of the chip must also be defined in the
2789 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2791 #define CONFIG_SYSTEMACE
2792 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2794 When SystemACE support is added, the "ace" device type
2795 becomes available to the fat commands, i.e. fatls.
2797 - TFTP Fixed UDP Port:
2800 If this is defined, the environment variable tftpsrcp
2801 is used to supply the TFTP UDP source port value.
2802 If tftpsrcp isn't defined, the normal pseudo-random port
2803 number generator is used.
2805 Also, the environment variable tftpdstp is used to supply
2806 the TFTP UDP destination port value. If tftpdstp isn't
2807 defined, the normal port 69 is used.
2809 The purpose for tftpsrcp is to allow a TFTP server to
2810 blindly start the TFTP transfer using the pre-configured
2811 target IP address and UDP port. This has the effect of
2812 "punching through" the (Windows XP) firewall, allowing
2813 the remainder of the TFTP transfer to proceed normally.
2814 A better solution is to properly configure the firewall,
2815 but sometimes that is not allowed.
2820 This enables a generic 'hash' command which can produce
2821 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2825 Enable the hash verify command (hash -v). This adds to code
2828 CONFIG_SHA1 - support SHA1 hashing
2829 CONFIG_SHA256 - support SHA256 hashing
2831 Note: There is also a sha1sum command, which should perhaps
2832 be deprecated in favour of 'hash sha1'.
2834 - Freescale i.MX specific commands:
2835 CONFIG_CMD_HDMIDETECT
2836 This enables 'hdmidet' command which returns true if an
2837 HDMI monitor is detected. This command is i.MX 6 specific.
2840 This enables the 'bmode' (bootmode) command for forcing
2841 a boot from specific media.
2843 This is useful for forcing the ROM's usb downloader to
2844 activate upon a watchdog reset which is nice when iterating
2845 on U-Boot. Using the reset button or running bmode normal
2846 will set it back to normal. This command currently
2847 supports i.MX53 and i.MX6.
2852 This enables the RSA algorithm used for FIT image verification
2853 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2855 The signing part is build into mkimage regardless of this
2858 - bootcount support:
2859 CONFIG_BOOTCOUNT_LIMIT
2861 This enables the bootcounter support, see:
2862 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2865 enable special bootcounter support on at91sam9xe based boards.
2867 enable special bootcounter support on blackfin based boards.
2869 enable special bootcounter support on da850 based boards.
2870 CONFIG_BOOTCOUNT_RAM
2871 enable support for the bootcounter in RAM
2872 CONFIG_BOOTCOUNT_I2C
2873 enable support for the bootcounter on an i2c (like RTC) device.
2874 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2875 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2877 CONFIG_BOOTCOUNT_ALEN = address len
2879 - Show boot progress:
2880 CONFIG_SHOW_BOOT_PROGRESS
2882 Defining this option allows to add some board-
2883 specific code (calling a user-provided function
2884 "show_boot_progress(int)") that enables you to show
2885 the system's boot progress on some display (for
2886 example, some LED's) on your board. At the moment,
2887 the following checkpoints are implemented:
2889 - Detailed boot stage timing
2891 Define this option to get detailed timing of each stage
2892 of the boot process.
2894 CONFIG_BOOTSTAGE_USER_COUNT
2895 This is the number of available user bootstage records.
2896 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2897 a new ID will be allocated from this stash. If you exceed
2898 the limit, recording will stop.
2900 CONFIG_BOOTSTAGE_REPORT
2901 Define this to print a report before boot, similar to this:
2903 Timer summary in microseconds:
2906 3,575,678 3,575,678 board_init_f start
2907 3,575,695 17 arch_cpu_init A9
2908 3,575,777 82 arch_cpu_init done
2909 3,659,598 83,821 board_init_r start
2910 3,910,375 250,777 main_loop
2911 29,916,167 26,005,792 bootm_start
2912 30,361,327 445,160 start_kernel
2914 CONFIG_CMD_BOOTSTAGE
2915 Add a 'bootstage' command which supports printing a report
2916 and un/stashing of bootstage data.
2918 CONFIG_BOOTSTAGE_FDT
2919 Stash the bootstage information in the FDT. A root 'bootstage'
2920 node is created with each bootstage id as a child. Each child
2921 has a 'name' property and either 'mark' containing the
2922 mark time in microsecond, or 'accum' containing the
2923 accumulated time for that bootstage id in microseconds.
2928 name = "board_init_f";
2937 Code in the Linux kernel can find this in /proc/devicetree.
2939 Legacy uImage format:
2942 1 common/cmd_bootm.c before attempting to boot an image
2943 -1 common/cmd_bootm.c Image header has bad magic number
2944 2 common/cmd_bootm.c Image header has correct magic number
2945 -2 common/cmd_bootm.c Image header has bad checksum
2946 3 common/cmd_bootm.c Image header has correct checksum
2947 -3 common/cmd_bootm.c Image data has bad checksum
2948 4 common/cmd_bootm.c Image data has correct checksum
2949 -4 common/cmd_bootm.c Image is for unsupported architecture
2950 5 common/cmd_bootm.c Architecture check OK
2951 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2952 6 common/cmd_bootm.c Image Type check OK
2953 -6 common/cmd_bootm.c gunzip uncompression error
2954 -7 common/cmd_bootm.c Unimplemented compression type
2955 7 common/cmd_bootm.c Uncompression OK
2956 8 common/cmd_bootm.c No uncompress/copy overwrite error
2957 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2959 9 common/image.c Start initial ramdisk verification
2960 -10 common/image.c Ramdisk header has bad magic number
2961 -11 common/image.c Ramdisk header has bad checksum
2962 10 common/image.c Ramdisk header is OK
2963 -12 common/image.c Ramdisk data has bad checksum
2964 11 common/image.c Ramdisk data has correct checksum
2965 12 common/image.c Ramdisk verification complete, start loading
2966 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2967 13 common/image.c Start multifile image verification
2968 14 common/image.c No initial ramdisk, no multifile, continue.
2970 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2972 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2973 -31 post/post.c POST test failed, detected by post_output_backlog()
2974 -32 post/post.c POST test failed, detected by post_run_single()
2976 34 common/cmd_doc.c before loading a Image from a DOC device
2977 -35 common/cmd_doc.c Bad usage of "doc" command
2978 35 common/cmd_doc.c correct usage of "doc" command
2979 -36 common/cmd_doc.c No boot device
2980 36 common/cmd_doc.c correct boot device
2981 -37 common/cmd_doc.c Unknown Chip ID on boot device
2982 37 common/cmd_doc.c correct chip ID found, device available
2983 -38 common/cmd_doc.c Read Error on boot device
2984 38 common/cmd_doc.c reading Image header from DOC device OK
2985 -39 common/cmd_doc.c Image header has bad magic number
2986 39 common/cmd_doc.c Image header has correct magic number
2987 -40 common/cmd_doc.c Error reading Image from DOC device
2988 40 common/cmd_doc.c Image header has correct magic number
2989 41 common/cmd_ide.c before loading a Image from a IDE device
2990 -42 common/cmd_ide.c Bad usage of "ide" command
2991 42 common/cmd_ide.c correct usage of "ide" command
2992 -43 common/cmd_ide.c No boot device
2993 43 common/cmd_ide.c boot device found
2994 -44 common/cmd_ide.c Device not available
2995 44 common/cmd_ide.c Device available
2996 -45 common/cmd_ide.c wrong partition selected
2997 45 common/cmd_ide.c partition selected
2998 -46 common/cmd_ide.c Unknown partition table
2999 46 common/cmd_ide.c valid partition table found
3000 -47 common/cmd_ide.c Invalid partition type
3001 47 common/cmd_ide.c correct partition type
3002 -48 common/cmd_ide.c Error reading Image Header on boot device
3003 48 common/cmd_ide.c reading Image Header from IDE device OK
3004 -49 common/cmd_ide.c Image header has bad magic number
3005 49 common/cmd_ide.c Image header has correct magic number
3006 -50 common/cmd_ide.c Image header has bad checksum
3007 50 common/cmd_ide.c Image header has correct checksum
3008 -51 common/cmd_ide.c Error reading Image from IDE device
3009 51 common/cmd_ide.c reading Image from IDE device OK
3010 52 common/cmd_nand.c before loading a Image from a NAND device
3011 -53 common/cmd_nand.c Bad usage of "nand" command
3012 53 common/cmd_nand.c correct usage of "nand" command
3013 -54 common/cmd_nand.c No boot device
3014 54 common/cmd_nand.c boot device found
3015 -55 common/cmd_nand.c Unknown Chip ID on boot device
3016 55 common/cmd_nand.c correct chip ID found, device available
3017 -56 common/cmd_nand.c Error reading Image Header on boot device
3018 56 common/cmd_nand.c reading Image Header from NAND device OK
3019 -57 common/cmd_nand.c Image header has bad magic number
3020 57 common/cmd_nand.c Image header has correct magic number
3021 -58 common/cmd_nand.c Error reading Image from NAND device
3022 58 common/cmd_nand.c reading Image from NAND device OK
3024 -60 common/env_common.c Environment has a bad CRC, using default
3026 64 net/eth.c starting with Ethernet configuration.
3027 -64 net/eth.c no Ethernet found.
3028 65 net/eth.c Ethernet found.
3030 -80 common/cmd_net.c usage wrong
3031 80 common/cmd_net.c before calling NetLoop()
3032 -81 common/cmd_net.c some error in NetLoop() occurred
3033 81 common/cmd_net.c NetLoop() back without error
3034 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3035 82 common/cmd_net.c trying automatic boot
3036 83 common/cmd_net.c running "source" command
3037 -83 common/cmd_net.c some error in automatic boot or "source" command
3038 84 common/cmd_net.c end without errors
3043 100 common/cmd_bootm.c Kernel FIT Image has correct format
3044 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3045 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3046 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3047 102 common/cmd_bootm.c Kernel unit name specified
3048 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3049 103 common/cmd_bootm.c Found configuration node
3050 104 common/cmd_bootm.c Got kernel subimage node offset
3051 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3052 105 common/cmd_bootm.c Kernel subimage hash verification OK
3053 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3054 106 common/cmd_bootm.c Architecture check OK
3055 -106 common/cmd_bootm.c Kernel subimage has wrong type
3056 107 common/cmd_bootm.c Kernel subimage type OK
3057 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3058 108 common/cmd_bootm.c Got kernel subimage data/size
3059 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3060 -109 common/cmd_bootm.c Can't get kernel subimage type
3061 -110 common/cmd_bootm.c Can't get kernel subimage comp
3062 -111 common/cmd_bootm.c Can't get kernel subimage os
3063 -112 common/cmd_bootm.c Can't get kernel subimage load address
3064 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3066 120 common/image.c Start initial ramdisk verification
3067 -120 common/image.c Ramdisk FIT image has incorrect format
3068 121 common/image.c Ramdisk FIT image has correct format
3069 122 common/image.c No ramdisk subimage unit name, using configuration
3070 -122 common/image.c Can't get configuration for ramdisk subimage
3071 123 common/image.c Ramdisk unit name specified
3072 -124 common/image.c Can't get ramdisk subimage node offset
3073 125 common/image.c Got ramdisk subimage node offset
3074 -125 common/image.c Ramdisk subimage hash verification failed
3075 126 common/image.c Ramdisk subimage hash verification OK
3076 -126 common/image.c Ramdisk subimage for unsupported architecture
3077 127 common/image.c Architecture check OK
3078 -127 common/image.c Can't get ramdisk subimage data/size
3079 128 common/image.c Got ramdisk subimage data/size
3080 129 common/image.c Can't get ramdisk load address
3081 -129 common/image.c Got ramdisk load address
3083 -130 common/cmd_doc.c Incorrect FIT image format
3084 131 common/cmd_doc.c FIT image format OK
3086 -140 common/cmd_ide.c Incorrect FIT image format
3087 141 common/cmd_ide.c FIT image format OK
3089 -150 common/cmd_nand.c Incorrect FIT image format
3090 151 common/cmd_nand.c FIT image format OK
3092 - FIT image support:
3094 Enable support for the FIT uImage format.
3096 CONFIG_FIT_BEST_MATCH
3097 When no configuration is explicitly selected, default to the
3098 one whose fdt's compatibility field best matches that of
3099 U-Boot itself. A match is considered "best" if it matches the
3100 most specific compatibility entry of U-Boot's fdt's root node.
3101 The order of entries in the configuration's fdt is ignored.
3103 CONFIG_FIT_SIGNATURE
3104 This option enables signature verification of FIT uImages,
3105 using a hash signed and verified using RSA. See
3106 doc/uImage.FIT/signature.txt for more details.
3108 - Standalone program support:
3109 CONFIG_STANDALONE_LOAD_ADDR
3111 This option defines a board specific value for the
3112 address where standalone program gets loaded, thus
3113 overwriting the architecture dependent default
3116 - Frame Buffer Address:
3119 Define CONFIG_FB_ADDR if you want to use specific
3120 address for frame buffer. This is typically the case
3121 when using a graphics controller has separate video
3122 memory. U-Boot will then place the frame buffer at
3123 the given address instead of dynamically reserving it
3124 in system RAM by calling lcd_setmem(), which grabs
3125 the memory for the frame buffer depending on the
3126 configured panel size.
3128 Please see board_init_f function.
3130 - Automatic software updates via TFTP server
3132 CONFIG_UPDATE_TFTP_CNT_MAX
3133 CONFIG_UPDATE_TFTP_MSEC_MAX
3135 These options enable and control the auto-update feature;
3136 for a more detailed description refer to doc/README.update.
3138 - MTD Support (mtdparts command, UBI support)
3141 Adds the MTD device infrastructure from the Linux kernel.
3142 Needed for mtdparts command support.
3144 CONFIG_MTD_PARTITIONS
3146 Adds the MTD partitioning infrastructure from the Linux
3147 kernel. Needed for UBI support.
3152 Adds commands for interacting with MTD partitions formatted
3153 with the UBI flash translation layer
3155 Requires also defining CONFIG_RBTREE
3157 CONFIG_UBI_SILENCE_MSG
3159 Make the verbose messages from UBI stop printing. This leaves
3160 warnings and errors enabled.
3165 Adds commands for interacting with UBI volumes formatted as
3166 UBIFS. UBIFS is read-only in u-boot.
3168 Requires UBI support as well as CONFIG_LZO
3170 CONFIG_UBIFS_SILENCE_MSG
3172 Make the verbose messages from UBIFS stop printing. This leaves
3173 warnings and errors enabled.
3177 Enable building of SPL globally.
3180 LDSCRIPT for linking the SPL binary.
3182 CONFIG_SPL_MAX_FOOTPRINT
3183 Maximum size in memory allocated to the SPL, BSS included.
3184 When defined, the linker checks that the actual memory
3185 used by SPL from _start to __bss_end does not exceed it.
3186 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3187 must not be both defined at the same time.
3190 Maximum size of the SPL image (text, data, rodata, and
3191 linker lists sections), BSS excluded.
3192 When defined, the linker checks that the actual size does
3195 CONFIG_SPL_TEXT_BASE
3196 TEXT_BASE for linking the SPL binary.
3198 CONFIG_SPL_RELOC_TEXT_BASE
3199 Address to relocate to. If unspecified, this is equal to
3200 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3202 CONFIG_SPL_BSS_START_ADDR
3203 Link address for the BSS within the SPL binary.
3205 CONFIG_SPL_BSS_MAX_SIZE
3206 Maximum size in memory allocated to the SPL BSS.
3207 When defined, the linker checks that the actual memory used
3208 by SPL from __bss_start to __bss_end does not exceed it.
3209 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3210 must not be both defined at the same time.
3213 Adress of the start of the stack SPL will use
3215 CONFIG_SPL_RELOC_STACK
3216 Adress of the start of the stack SPL will use after
3217 relocation. If unspecified, this is equal to
3220 CONFIG_SYS_SPL_MALLOC_START
3221 Starting address of the malloc pool used in SPL.
3223 CONFIG_SYS_SPL_MALLOC_SIZE
3224 The size of the malloc pool used in SPL.
3226 CONFIG_SPL_FRAMEWORK
3227 Enable the SPL framework under common/. This framework
3228 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3229 NAND loading of the Linux Kernel.
3231 CONFIG_SPL_DISPLAY_PRINT
3232 For ARM, enable an optional function to print more information
3233 about the running system.
3235 CONFIG_SPL_INIT_MINIMAL
3236 Arch init code should be built for a very small image
3238 CONFIG_SPL_LIBCOMMON_SUPPORT
3239 Support for common/libcommon.o in SPL binary
3241 CONFIG_SPL_LIBDISK_SUPPORT
3242 Support for disk/libdisk.o in SPL binary
3244 CONFIG_SPL_I2C_SUPPORT
3245 Support for drivers/i2c/libi2c.o in SPL binary
3247 CONFIG_SPL_GPIO_SUPPORT
3248 Support for drivers/gpio/libgpio.o in SPL binary
3250 CONFIG_SPL_MMC_SUPPORT
3251 Support for drivers/mmc/libmmc.o in SPL binary
3253 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3254 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3255 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3256 Address, size and partition on the MMC to load U-Boot from
3257 when the MMC is being used in raw mode.
3259 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3260 Sector to load kernel uImage from when MMC is being
3261 used in raw mode (for Falcon mode)
3263 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3264 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3265 Sector and number of sectors to load kernel argument
3266 parameters from when MMC is being used in raw mode
3269 CONFIG_SPL_FAT_SUPPORT
3270 Support for fs/fat/libfat.o in SPL binary
3272 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3273 Filename to read to load U-Boot when reading from FAT
3275 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3276 Filename to read to load kernel uImage when reading
3277 from FAT (for Falcon mode)
3279 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3280 Filename to read to load kernel argument parameters
3281 when reading from FAT (for Falcon mode)
3283 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3284 Set this for NAND SPL on PPC mpc83xx targets, so that
3285 start.S waits for the rest of the SPL to load before
3286 continuing (the hardware starts execution after just
3287 loading the first page rather than the full 4K).
3289 CONFIG_SPL_NAND_BASE
3290 Include nand_base.c in the SPL. Requires
3291 CONFIG_SPL_NAND_DRIVERS.
3293 CONFIG_SPL_NAND_DRIVERS
3294 SPL uses normal NAND drivers, not minimal drivers.
3297 Include standard software ECC in the SPL
3299 CONFIG_SPL_NAND_SIMPLE
3300 Support for NAND boot using simple NAND drivers that
3301 expose the cmd_ctrl() interface.
3303 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3304 Set for the SPL on PPC mpc8xxx targets, support for
3305 drivers/ddr/fsl/libddr.o in SPL binary.
3307 CONFIG_SPL_COMMON_INIT_DDR
3308 Set for common ddr init with serial presence detect in
3311 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3312 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3313 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3314 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3315 CONFIG_SYS_NAND_ECCBYTES
3316 Defines the size and behavior of the NAND that SPL uses
3319 CONFIG_SPL_NAND_BOOT
3320 Add support NAND boot
3322 CONFIG_SYS_NAND_U_BOOT_OFFS
3323 Location in NAND to read U-Boot from
3325 CONFIG_SYS_NAND_U_BOOT_DST
3326 Location in memory to load U-Boot to
3328 CONFIG_SYS_NAND_U_BOOT_SIZE
3329 Size of image to load
3331 CONFIG_SYS_NAND_U_BOOT_START
3332 Entry point in loaded image to jump to
3334 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3335 Define this if you need to first read the OOB and then the
3336 data. This is used for example on davinci plattforms.
3338 CONFIG_SPL_OMAP3_ID_NAND
3339 Support for an OMAP3-specific set of functions to return the
3340 ID and MFR of the first attached NAND chip, if present.
3342 CONFIG_SPL_SERIAL_SUPPORT
3343 Support for drivers/serial/libserial.o in SPL binary
3345 CONFIG_SPL_SPI_FLASH_SUPPORT
3346 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3348 CONFIG_SPL_SPI_SUPPORT
3349 Support for drivers/spi/libspi.o in SPL binary
3351 CONFIG_SPL_RAM_DEVICE
3352 Support for running image already present in ram, in SPL binary
3354 CONFIG_SPL_LIBGENERIC_SUPPORT
3355 Support for lib/libgeneric.o in SPL binary
3357 CONFIG_SPL_ENV_SUPPORT
3358 Support for the environment operating in SPL binary
3360 CONFIG_SPL_NET_SUPPORT
3361 Support for the net/libnet.o in SPL binary.
3362 It conflicts with SPL env from storage medium specified by
3363 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3366 Image offset to which the SPL should be padded before appending
3367 the SPL 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.
3373 Final target image containing SPL and payload. Some SPLs
3374 use an arch-specific makefile fragment instead, for
3375 example if more than one image needs to be produced.
3377 CONFIG_FIT_SPL_PRINT
3378 Printing information about a FIT image adds quite a bit of
3379 code to SPL. So this is normally disabled in SPL. Use this
3380 option to re-enable it. This will affect the output of the
3381 bootm command when booting a FIT image.
3385 Enable building of TPL globally.
3388 Image offset to which the TPL should be padded before appending
3389 the TPL payload. By default, this is defined as
3390 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3391 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3392 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3397 [so far only for SMDK2400 boards]
3399 - Modem support enable:
3400 CONFIG_MODEM_SUPPORT
3402 - RTS/CTS Flow control enable:
3405 - Modem debug support:
3406 CONFIG_MODEM_SUPPORT_DEBUG
3408 Enables debugging stuff (char screen[1024], dbg())
3409 for modem support. Useful only with BDI2000.
3411 - Interrupt support (PPC):
3413 There are common interrupt_init() and timer_interrupt()
3414 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3415 for CPU specific initialization. interrupt_init_cpu()
3416 should set decrementer_count to appropriate value. If
3417 CPU resets decrementer automatically after interrupt
3418 (ppc4xx) it should set decrementer_count to zero.
3419 timer_interrupt() calls timer_interrupt_cpu() for CPU
3420 specific handling. If board has watchdog / status_led
3421 / other_activity_monitor it works automatically from
3422 general timer_interrupt().
3426 In the target system modem support is enabled when a
3427 specific key (key combination) is pressed during
3428 power-on. Otherwise U-Boot will boot normally
3429 (autoboot). The key_pressed() function is called from
3430 board_init(). Currently key_pressed() is a dummy
3431 function, returning 1 and thus enabling modem
3434 If there are no modem init strings in the
3435 environment, U-Boot proceed to autoboot; the
3436 previous output (banner, info printfs) will be
3439 See also: doc/README.Modem
3441 Board initialization settings:
3442 ------------------------------
3444 During Initialization u-boot calls a number of board specific functions
3445 to allow the preparation of board specific prerequisites, e.g. pin setup
3446 before drivers are initialized. To enable these callbacks the
3447 following configuration macros have to be defined. Currently this is
3448 architecture specific, so please check arch/your_architecture/lib/board.c
3449 typically in board_init_f() and board_init_r().
3451 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3452 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3453 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3454 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3456 Configuration Settings:
3457 -----------------------
3459 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3460 undefine this when you're short of memory.
3462 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3463 width of the commands listed in the 'help' command output.
3465 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3466 prompt for user input.
3468 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3470 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3472 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3474 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3475 the application (usually a Linux kernel) when it is
3478 - CONFIG_SYS_BAUDRATE_TABLE:
3479 List of legal baudrate settings for this board.
3481 - CONFIG_SYS_CONSOLE_INFO_QUIET
3482 Suppress display of console information at boot.
3484 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3485 If the board specific function
3486 extern int overwrite_console (void);
3487 returns 1, the stdin, stderr and stdout are switched to the
3488 serial port, else the settings in the environment are used.
3490 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3491 Enable the call to overwrite_console().
3493 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3494 Enable overwrite of previous console environment settings.
3496 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3497 Begin and End addresses of the area used by the
3500 - CONFIG_SYS_ALT_MEMTEST:
3501 Enable an alternate, more extensive memory test.
3503 - CONFIG_SYS_MEMTEST_SCRATCH:
3504 Scratch address used by the alternate memory test
3505 You only need to set this if address zero isn't writeable
3507 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3508 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3509 this specified memory area will get subtracted from the top
3510 (end) of RAM and won't get "touched" at all by U-Boot. By
3511 fixing up gd->ram_size the Linux kernel should gets passed
3512 the now "corrected" memory size and won't touch it either.
3513 This should work for arch/ppc and arch/powerpc. Only Linux
3514 board ports in arch/powerpc with bootwrapper support that
3515 recalculate the memory size from the SDRAM controller setup
3516 will have to get fixed in Linux additionally.
3518 This option can be used as a workaround for the 440EPx/GRx
3519 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3522 WARNING: Please make sure that this value is a multiple of
3523 the Linux page size (normally 4k). If this is not the case,
3524 then the end address of the Linux memory will be located at a
3525 non page size aligned address and this could cause major
3528 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3529 Enable temporary baudrate change while serial download
3531 - CONFIG_SYS_SDRAM_BASE:
3532 Physical start address of SDRAM. _Must_ be 0 here.
3534 - CONFIG_SYS_MBIO_BASE:
3535 Physical start address of Motherboard I/O (if using a
3538 - CONFIG_SYS_FLASH_BASE:
3539 Physical start address of Flash memory.
3541 - CONFIG_SYS_MONITOR_BASE:
3542 Physical start address of boot monitor code (set by
3543 make config files to be same as the text base address
3544 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3545 CONFIG_SYS_FLASH_BASE when booting from flash.
3547 - CONFIG_SYS_MONITOR_LEN:
3548 Size of memory reserved for monitor code, used to
3549 determine _at_compile_time_ (!) if the environment is
3550 embedded within the U-Boot image, or in a separate
3553 - CONFIG_SYS_MALLOC_LEN:
3554 Size of DRAM reserved for malloc() use.
3556 - CONFIG_SYS_BOOTM_LEN:
3557 Normally compressed uImages are limited to an
3558 uncompressed size of 8 MBytes. If this is not enough,
3559 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3560 to adjust this setting to your needs.
3562 - CONFIG_SYS_BOOTMAPSZ:
3563 Maximum size of memory mapped by the startup code of
3564 the Linux kernel; all data that must be processed by
3565 the Linux kernel (bd_info, boot arguments, FDT blob if
3566 used) must be put below this limit, unless "bootm_low"
3567 environment variable is defined and non-zero. In such case
3568 all data for the Linux kernel must be between "bootm_low"
3569 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3570 variable "bootm_mapsize" will override the value of
3571 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3572 then the value in "bootm_size" will be used instead.
3574 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3575 Enable initrd_high functionality. If defined then the
3576 initrd_high feature is enabled and the bootm ramdisk subcommand
3579 - CONFIG_SYS_BOOT_GET_CMDLINE:
3580 Enables allocating and saving kernel cmdline in space between
3581 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3583 - CONFIG_SYS_BOOT_GET_KBD:
3584 Enables allocating and saving a kernel copy of the bd_info in
3585 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3587 - CONFIG_SYS_MAX_FLASH_BANKS:
3588 Max number of Flash memory banks
3590 - CONFIG_SYS_MAX_FLASH_SECT:
3591 Max number of sectors on a Flash chip
3593 - CONFIG_SYS_FLASH_ERASE_TOUT:
3594 Timeout for Flash erase operations (in ms)
3596 - CONFIG_SYS_FLASH_WRITE_TOUT:
3597 Timeout for Flash write operations (in ms)
3599 - CONFIG_SYS_FLASH_LOCK_TOUT
3600 Timeout for Flash set sector lock bit operation (in ms)
3602 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3603 Timeout for Flash clear lock bits operation (in ms)
3605 - CONFIG_SYS_FLASH_PROTECTION
3606 If defined, hardware flash sectors protection is used
3607 instead of U-Boot software protection.
3609 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3611 Enable TFTP transfers directly to flash memory;
3612 without this option such a download has to be
3613 performed in two steps: (1) download to RAM, and (2)
3614 copy from RAM to flash.
3616 The two-step approach is usually more reliable, since
3617 you can check if the download worked before you erase
3618 the flash, but in some situations (when system RAM is
3619 too limited to allow for a temporary copy of the
3620 downloaded image) this option may be very useful.
3622 - CONFIG_SYS_FLASH_CFI:
3623 Define if the flash driver uses extra elements in the
3624 common flash structure for storing flash geometry.
3626 - CONFIG_FLASH_CFI_DRIVER
3627 This option also enables the building of the cfi_flash driver
3628 in the drivers directory
3630 - CONFIG_FLASH_CFI_MTD
3631 This option enables the building of the cfi_mtd driver
3632 in the drivers directory. The driver exports CFI flash
3635 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3636 Use buffered writes to flash.
3638 - CONFIG_FLASH_SPANSION_S29WS_N
3639 s29ws-n MirrorBit flash has non-standard addresses for buffered
3642 - CONFIG_SYS_FLASH_QUIET_TEST
3643 If this option is defined, the common CFI flash doesn't
3644 print it's warning upon not recognized FLASH banks. This
3645 is useful, if some of the configured banks are only
3646 optionally available.
3648 - CONFIG_FLASH_SHOW_PROGRESS
3649 If defined (must be an integer), print out countdown
3650 digits and dots. Recommended value: 45 (9..1) for 80
3651 column displays, 15 (3..1) for 40 column displays.
3653 - CONFIG_FLASH_VERIFY
3654 If defined, the content of the flash (destination) is compared
3655 against the source after the write operation. An error message
3656 will be printed when the contents are not identical.
3657 Please note that this option is useless in nearly all cases,
3658 since such flash programming errors usually are detected earlier
3659 while unprotecting/erasing/programming. Please only enable
3660 this option if you really know what you are doing.
3662 - CONFIG_SYS_RX_ETH_BUFFER:
3663 Defines the number of Ethernet receive buffers. On some
3664 Ethernet controllers it is recommended to set this value
3665 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3666 buffers can be full shortly after enabling the interface
3667 on high Ethernet traffic.
3668 Defaults to 4 if not defined.
3670 - CONFIG_ENV_MAX_ENTRIES
3672 Maximum number of entries in the hash table that is used
3673 internally to store the environment settings. The default
3674 setting is supposed to be generous and should work in most
3675 cases. This setting can be used to tune behaviour; see
3676 lib/hashtable.c for details.
3678 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3679 - CONFIG_ENV_FLAGS_LIST_STATIC
3680 Enable validation of the values given to environment variables when
3681 calling env set. Variables can be restricted to only decimal,
3682 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3683 the variables can also be restricted to IP address or MAC address.
3685 The format of the list is:
3686 type_attribute = [s|d|x|b|i|m]
3687 access_atribute = [a|r|o|c]
3688 attributes = type_attribute[access_atribute]
3689 entry = variable_name[:attributes]
3692 The type attributes are:
3693 s - String (default)
3696 b - Boolean ([1yYtT|0nNfF])
3700 The access attributes are:
3706 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3707 Define this to a list (string) to define the ".flags"
3708 envirnoment variable in the default or embedded environment.
3710 - CONFIG_ENV_FLAGS_LIST_STATIC
3711 Define this to a list (string) to define validation that
3712 should be done if an entry is not found in the ".flags"
3713 environment variable. To override a setting in the static
3714 list, simply add an entry for the same variable name to the
3717 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3718 If defined, don't allow the -f switch to env set override variable
3721 - CONFIG_SYS_GENERIC_BOARD
3722 This selects the architecture-generic board system instead of the
3723 architecture-specific board files. It is intended to move boards
3724 to this new framework over time. Defining this will disable the
3725 arch/foo/lib/board.c file and use common/board_f.c and
3726 common/board_r.c instead. To use this option your architecture
3727 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3728 its config.mk file). If you find problems enabling this option on
3729 your board please report the problem and send patches!
3731 - CONFIG_SYS_SYM_OFFSETS
3732 This is set by architectures that use offsets for link symbols
3733 instead of absolute values. So bss_start is obtained using an
3734 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3735 directly. You should not need to touch this setting.
3737 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3738 This is set by OMAP boards for the max time that reset should
3739 be asserted. See doc/README.omap-reset-time for details on how
3740 the value can be calulated on a given board.
3742 The following definitions that deal with the placement and management
3743 of environment data (variable area); in general, we support the
3744 following configurations:
3746 - CONFIG_BUILD_ENVCRC:
3748 Builds up envcrc with the target environment so that external utils
3749 may easily extract it and embed it in final U-Boot images.
3751 - CONFIG_ENV_IS_IN_FLASH:
3753 Define this if the environment is in flash memory.
3755 a) The environment occupies one whole flash sector, which is
3756 "embedded" in the text segment with the U-Boot code. This
3757 happens usually with "bottom boot sector" or "top boot
3758 sector" type flash chips, which have several smaller
3759 sectors at the start or the end. For instance, such a
3760 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3761 such a case you would place the environment in one of the
3762 4 kB sectors - with U-Boot code before and after it. With
3763 "top boot sector" type flash chips, you would put the
3764 environment in one of the last sectors, leaving a gap
3765 between U-Boot and the environment.
3767 - CONFIG_ENV_OFFSET:
3769 Offset of environment data (variable area) to the
3770 beginning of flash memory; for instance, with bottom boot
3771 type flash chips the second sector can be used: the offset
3772 for this sector is given here.
3774 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3778 This is just another way to specify the start address of
3779 the flash sector containing the environment (instead of
3782 - CONFIG_ENV_SECT_SIZE:
3784 Size of the sector containing the environment.
3787 b) Sometimes flash chips have few, equal sized, BIG sectors.
3788 In such a case you don't want to spend a whole sector for
3793 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3794 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3795 of this flash sector for the environment. This saves
3796 memory for the RAM copy of the environment.
3798 It may also save flash memory if you decide to use this
3799 when your environment is "embedded" within U-Boot code,
3800 since then the remainder of the flash sector could be used
3801 for U-Boot code. It should be pointed out that this is
3802 STRONGLY DISCOURAGED from a robustness point of view:
3803 updating the environment in flash makes it always
3804 necessary to erase the WHOLE sector. If something goes
3805 wrong before the contents has been restored from a copy in
3806 RAM, your target system will be dead.
3808 - CONFIG_ENV_ADDR_REDUND
3809 CONFIG_ENV_SIZE_REDUND
3811 These settings describe a second storage area used to hold
3812 a redundant copy of the environment data, so that there is
3813 a valid backup copy in case there is a power failure during
3814 a "saveenv" operation.
3816 BE CAREFUL! Any changes to the flash layout, and some changes to the
3817 source code will make it necessary to adapt <board>/u-boot.lds*
3821 - CONFIG_ENV_IS_IN_NVRAM:
3823 Define this if you have some non-volatile memory device
3824 (NVRAM, battery buffered SRAM) which you want to use for the
3830 These two #defines are used to determine the memory area you
3831 want to use for environment. It is assumed that this memory
3832 can just be read and written to, without any special
3835 BE CAREFUL! The first access to the environment happens quite early
3836 in U-Boot initalization (when we try to get the setting of for the
3837 console baudrate). You *MUST* have mapped your NVRAM area then, or
3840 Please note that even with NVRAM we still use a copy of the
3841 environment in RAM: we could work on NVRAM directly, but we want to
3842 keep settings there always unmodified except somebody uses "saveenv"
3843 to save the current settings.
3846 - CONFIG_ENV_IS_IN_EEPROM:
3848 Use this if you have an EEPROM or similar serial access
3849 device and a driver for it.
3851 - CONFIG_ENV_OFFSET:
3854 These two #defines specify the offset and size of the
3855 environment area within the total memory of your EEPROM.
3857 - CONFIG_SYS_I2C_EEPROM_ADDR:
3858 If defined, specified the chip address of the EEPROM device.
3859 The default address is zero.
3861 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3862 If defined, the number of bits used to address bytes in a
3863 single page in the EEPROM device. A 64 byte page, for example
3864 would require six bits.
3866 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3867 If defined, the number of milliseconds to delay between
3868 page writes. The default is zero milliseconds.
3870 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3871 The length in bytes of the EEPROM memory array address. Note
3872 that this is NOT the chip address length!
3874 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3875 EEPROM chips that implement "address overflow" are ones
3876 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3877 address and the extra bits end up in the "chip address" bit
3878 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3881 Note that we consider the length of the address field to
3882 still be one byte because the extra address bits are hidden
3883 in the chip address.
3885 - CONFIG_SYS_EEPROM_SIZE:
3886 The size in bytes of the EEPROM device.
3888 - CONFIG_ENV_EEPROM_IS_ON_I2C
3889 define this, if you have I2C and SPI activated, and your
3890 EEPROM, which holds the environment, is on the I2C bus.
3892 - CONFIG_I2C_ENV_EEPROM_BUS
3893 if you have an Environment on an EEPROM reached over
3894 I2C muxes, you can define here, how to reach this
3895 EEPROM. For example:
3897 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3899 EEPROM which holds the environment, is reached over
3900 a pca9547 i2c mux with address 0x70, channel 3.
3902 - CONFIG_ENV_IS_IN_DATAFLASH:
3904 Define this if you have a DataFlash memory device which you
3905 want to use for the environment.
3907 - CONFIG_ENV_OFFSET:
3911 These three #defines specify the offset and size of the
3912 environment area within the total memory of your DataFlash placed
3913 at the specified address.
3915 - CONFIG_ENV_IS_IN_REMOTE:
3917 Define this if you have a remote memory space which you
3918 want to use for the local device's environment.
3923 These two #defines specify the address and size of the
3924 environment area within the remote memory space. The
3925 local device can get the environment from remote memory
3926 space by SRIO or PCIE links.
3928 BE CAREFUL! For some special cases, the local device can not use
3929 "saveenv" command. For example, the local device will get the
3930 environment stored in a remote NOR flash by SRIO or PCIE link,
3931 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3933 - CONFIG_ENV_IS_IN_NAND:
3935 Define this if you have a NAND device which you want to use
3936 for the environment.
3938 - CONFIG_ENV_OFFSET:
3941 These two #defines specify the offset and size of the environment
3942 area within the first NAND device. CONFIG_ENV_OFFSET must be
3943 aligned to an erase block boundary.
3945 - CONFIG_ENV_OFFSET_REDUND (optional):
3947 This setting describes a second storage area of CONFIG_ENV_SIZE
3948 size used to hold a redundant copy of the environment data, so
3949 that there is a valid backup copy in case there is a power failure
3950 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3951 aligned to an erase block boundary.
3953 - CONFIG_ENV_RANGE (optional):
3955 Specifies the length of the region in which the environment
3956 can be written. This should be a multiple of the NAND device's
3957 block size. Specifying a range with more erase blocks than
3958 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3959 the range to be avoided.
3961 - CONFIG_ENV_OFFSET_OOB (optional):
3963 Enables support for dynamically retrieving the offset of the
3964 environment from block zero's out-of-band data. The
3965 "nand env.oob" command can be used to record this offset.
3966 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3967 using CONFIG_ENV_OFFSET_OOB.
3969 - CONFIG_NAND_ENV_DST
3971 Defines address in RAM to which the nand_spl code should copy the
3972 environment. If redundant environment is used, it will be copied to
3973 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3975 - CONFIG_ENV_IS_IN_UBI:
3977 Define this if you have an UBI volume that you want to use for the
3978 environment. This has the benefit of wear-leveling the environment
3979 accesses, which is important on NAND.
3981 - CONFIG_ENV_UBI_PART:
3983 Define this to a string that is the mtd partition containing the UBI.
3985 - CONFIG_ENV_UBI_VOLUME:
3987 Define this to the name of the volume that you want to store the
3990 - CONFIG_ENV_UBI_VOLUME_REDUND:
3992 Define this to the name of another volume to store a second copy of
3993 the environment in. This will enable redundant environments in UBI.
3994 It is assumed that both volumes are in the same MTD partition.
3996 - CONFIG_UBI_SILENCE_MSG
3997 - CONFIG_UBIFS_SILENCE_MSG
3999 You will probably want to define these to avoid a really noisy system
4000 when storing the env in UBI.
4002 - CONFIG_ENV_IS_IN_MMC:
4004 Define this if you have an MMC device which you want to use for the
4007 - CONFIG_SYS_MMC_ENV_DEV:
4009 Specifies which MMC device the environment is stored in.
4011 - CONFIG_SYS_MMC_ENV_PART (optional):
4013 Specifies which MMC partition the environment is stored in. If not
4014 set, defaults to partition 0, the user area. Common values might be
4015 1 (first MMC boot partition), 2 (second MMC boot partition).
4017 - CONFIG_ENV_OFFSET:
4020 These two #defines specify the offset and size of the environment
4021 area within the specified MMC device.
4023 If offset is positive (the usual case), it is treated as relative to
4024 the start of the MMC partition. If offset is negative, it is treated
4025 as relative to the end of the MMC partition. This can be useful if
4026 your board may be fitted with different MMC devices, which have
4027 different sizes for the MMC partitions, and you always want the
4028 environment placed at the very end of the partition, to leave the
4029 maximum possible space before it, to store other data.
4031 These two values are in units of bytes, but must be aligned to an
4032 MMC sector boundary.
4034 - CONFIG_ENV_OFFSET_REDUND (optional):
4036 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4037 hold a redundant copy of the environment data. This provides a
4038 valid backup copy in case the other copy is corrupted, e.g. due
4039 to a power failure during a "saveenv" operation.
4041 This value may also be positive or negative; this is handled in the
4042 same way as CONFIG_ENV_OFFSET.
4044 This value is also in units of bytes, but must also be aligned to
4045 an MMC sector boundary.
4047 - CONFIG_ENV_SIZE_REDUND (optional):
4049 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4050 set. If this value is set, it must be set to the same value as
4053 - CONFIG_SYS_SPI_INIT_OFFSET
4055 Defines offset to the initial SPI buffer area in DPRAM. The
4056 area is used at an early stage (ROM part) if the environment
4057 is configured to reside in the SPI EEPROM: We need a 520 byte
4058 scratch DPRAM area. It is used between the two initialization
4059 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4060 to be a good choice since it makes it far enough from the
4061 start of the data area as well as from the stack pointer.
4063 Please note that the environment is read-only until the monitor
4064 has been relocated to RAM and a RAM copy of the environment has been
4065 created; also, when using EEPROM you will have to use getenv_f()
4066 until then to read environment variables.
4068 The environment is protected by a CRC32 checksum. Before the monitor
4069 is relocated into RAM, as a result of a bad CRC you will be working
4070 with the compiled-in default environment - *silently*!!! [This is
4071 necessary, because the first environment variable we need is the
4072 "baudrate" setting for the console - if we have a bad CRC, we don't
4073 have any device yet where we could complain.]
4075 Note: once the monitor has been relocated, then it will complain if
4076 the default environment is used; a new CRC is computed as soon as you
4077 use the "saveenv" command to store a valid environment.
4079 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4080 Echo the inverted Ethernet link state to the fault LED.
4082 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4083 also needs to be defined.
4085 - CONFIG_SYS_FAULT_MII_ADDR:
4086 MII address of the PHY to check for the Ethernet link state.
4088 - CONFIG_NS16550_MIN_FUNCTIONS:
4089 Define this if you desire to only have use of the NS16550_init
4090 and NS16550_putc functions for the serial driver located at
4091 drivers/serial/ns16550.c. This option is useful for saving
4092 space for already greatly restricted images, including but not
4093 limited to NAND_SPL configurations.
4095 - CONFIG_DISPLAY_BOARDINFO
4096 Display information about the board that U-Boot is running on
4097 when U-Boot starts up. The board function checkboard() is called
4100 - CONFIG_DISPLAY_BOARDINFO_LATE
4101 Similar to the previous option, but display this information
4102 later, once stdio is running and output goes to the LCD, if
4105 Low Level (hardware related) configuration options:
4106 ---------------------------------------------------
4108 - CONFIG_SYS_CACHELINE_SIZE:
4109 Cache Line Size of the CPU.
4111 - CONFIG_SYS_DEFAULT_IMMR:
4112 Default address of the IMMR after system reset.
4114 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4115 and RPXsuper) to be able to adjust the position of
4116 the IMMR register after a reset.
4118 - CONFIG_SYS_CCSRBAR_DEFAULT:
4119 Default (power-on reset) physical address of CCSR on Freescale
4122 - CONFIG_SYS_CCSRBAR:
4123 Virtual address of CCSR. On a 32-bit build, this is typically
4124 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4126 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4127 for cross-platform code that uses that macro instead.
4129 - CONFIG_SYS_CCSRBAR_PHYS:
4130 Physical address of CCSR. CCSR can be relocated to a new
4131 physical address, if desired. In this case, this macro should
4132 be set to that address. Otherwise, it should be set to the
4133 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4134 is typically relocated on 36-bit builds. It is recommended
4135 that this macro be defined via the _HIGH and _LOW macros:
4137 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4138 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4140 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4141 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4142 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4143 used in assembly code, so it must not contain typecasts or
4144 integer size suffixes (e.g. "ULL").
4146 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4147 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4148 used in assembly code, so it must not contain typecasts or
4149 integer size suffixes (e.g. "ULL").
4151 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4152 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4153 forced to a value that ensures that CCSR is not relocated.
4155 - Floppy Disk Support:
4156 CONFIG_SYS_FDC_DRIVE_NUMBER
4158 the default drive number (default value 0)
4160 CONFIG_SYS_ISA_IO_STRIDE
4162 defines the spacing between FDC chipset registers
4165 CONFIG_SYS_ISA_IO_OFFSET
4167 defines the offset of register from address. It
4168 depends on which part of the data bus is connected to
4169 the FDC chipset. (default value 0)
4171 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4172 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4175 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4176 fdc_hw_init() is called at the beginning of the FDC
4177 setup. fdc_hw_init() must be provided by the board
4178 source code. It is used to make hardware dependant
4182 Most IDE controllers were designed to be connected with PCI
4183 interface. Only few of them were designed for AHB interface.
4184 When software is doing ATA command and data transfer to
4185 IDE devices through IDE-AHB controller, some additional
4186 registers accessing to these kind of IDE-AHB controller
4189 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4190 DO NOT CHANGE unless you know exactly what you're
4191 doing! (11-4) [MPC8xx/82xx systems only]
4193 - CONFIG_SYS_INIT_RAM_ADDR:
4195 Start address of memory area that can be used for
4196 initial data and stack; please note that this must be
4197 writable memory that is working WITHOUT special
4198 initialization, i. e. you CANNOT use normal RAM which
4199 will become available only after programming the
4200 memory controller and running certain initialization
4203 U-Boot uses the following memory types:
4204 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4205 - MPC824X: data cache
4206 - PPC4xx: data cache
4208 - CONFIG_SYS_GBL_DATA_OFFSET:
4210 Offset of the initial data structure in the memory
4211 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4212 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4213 data is located at the end of the available space
4214 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4215 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4216 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4217 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4220 On the MPC824X (or other systems that use the data
4221 cache for initial memory) the address chosen for
4222 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4223 point to an otherwise UNUSED address space between
4224 the top of RAM and the start of the PCI space.
4226 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4228 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4230 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4232 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4234 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4236 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4238 - CONFIG_SYS_OR_TIMING_SDRAM:
4241 - CONFIG_SYS_MAMR_PTA:
4242 periodic timer for refresh
4244 - CONFIG_SYS_DER: Debug Event Register (37-47)
4246 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4247 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4248 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4249 CONFIG_SYS_BR1_PRELIM:
4250 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4252 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4253 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4254 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4255 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4257 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4258 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4259 Machine Mode Register and Memory Periodic Timer
4260 Prescaler definitions (SDRAM timing)
4262 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4263 enable I2C microcode relocation patch (MPC8xx);
4264 define relocation offset in DPRAM [DSP2]
4266 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4267 enable SMC microcode relocation patch (MPC8xx);
4268 define relocation offset in DPRAM [SMC1]
4270 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4271 enable SPI microcode relocation patch (MPC8xx);
4272 define relocation offset in DPRAM [SCC4]
4274 - CONFIG_SYS_USE_OSCCLK:
4275 Use OSCM clock mode on MBX8xx board. Be careful,
4276 wrong setting might damage your board. Read
4277 doc/README.MBX before setting this variable!
4279 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4280 Offset of the bootmode word in DPRAM used by post
4281 (Power On Self Tests). This definition overrides
4282 #define'd default value in commproc.h resp.
4285 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4286 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4287 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4288 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4289 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4290 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4291 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4292 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4293 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4295 - CONFIG_PCI_DISABLE_PCIE:
4296 Disable PCI-Express on systems where it is supported but not
4299 - CONFIG_PCI_ENUM_ONLY
4300 Only scan through and get the devices on the busses.
4301 Don't do any setup work, presumably because someone or
4302 something has already done it, and we don't need to do it
4303 a second time. Useful for platforms that are pre-booted
4304 by coreboot or similar.
4306 - CONFIG_PCI_INDIRECT_BRIDGE:
4307 Enable support for indirect PCI bridges.
4310 Chip has SRIO or not
4313 Board has SRIO 1 port available
4316 Board has SRIO 2 port available
4318 - CONFIG_SRIO_PCIE_BOOT_MASTER
4319 Board can support master function for Boot from SRIO and PCIE
4321 - CONFIG_SYS_SRIOn_MEM_VIRT:
4322 Virtual Address of SRIO port 'n' memory region
4324 - CONFIG_SYS_SRIOn_MEM_PHYS:
4325 Physical Address of SRIO port 'n' memory region
4327 - CONFIG_SYS_SRIOn_MEM_SIZE:
4328 Size of SRIO port 'n' memory region
4330 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4331 Defined to tell the NAND controller that the NAND chip is using
4333 Not all NAND drivers use this symbol.
4334 Example of drivers that use it:
4335 - drivers/mtd/nand/ndfc.c
4336 - drivers/mtd/nand/mxc_nand.c
4338 - CONFIG_SYS_NDFC_EBC0_CFG
4339 Sets the EBC0_CFG register for the NDFC. If not defined
4340 a default value will be used.
4343 Get DDR timing information from an I2C EEPROM. Common
4344 with pluggable memory modules such as SODIMMs
4347 I2C address of the SPD EEPROM
4349 - CONFIG_SYS_SPD_BUS_NUM
4350 If SPD EEPROM is on an I2C bus other than the first
4351 one, specify here. Note that the value must resolve
4352 to something your driver can deal with.
4354 - CONFIG_SYS_DDR_RAW_TIMING
4355 Get DDR timing information from other than SPD. Common with
4356 soldered DDR chips onboard without SPD. DDR raw timing
4357 parameters are extracted from datasheet and hard-coded into
4358 header files or board specific files.
4360 - CONFIG_FSL_DDR_INTERACTIVE
4361 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4363 - CONFIG_SYS_83XX_DDR_USES_CS0
4364 Only for 83xx systems. If specified, then DDR should
4365 be configured using CS0 and CS1 instead of CS2 and CS3.
4367 - CONFIG_ETHER_ON_FEC[12]
4368 Define to enable FEC[12] on a 8xx series processor.
4370 - CONFIG_FEC[12]_PHY
4371 Define to the hardcoded PHY address which corresponds
4372 to the given FEC; i. e.
4373 #define CONFIG_FEC1_PHY 4
4374 means that the PHY with address 4 is connected to FEC1
4376 When set to -1, means to probe for first available.
4378 - CONFIG_FEC[12]_PHY_NORXERR
4379 The PHY does not have a RXERR line (RMII only).
4380 (so program the FEC to ignore it).
4383 Enable RMII mode for all FECs.
4384 Note that this is a global option, we can't
4385 have one FEC in standard MII mode and another in RMII mode.
4387 - CONFIG_CRC32_VERIFY
4388 Add a verify option to the crc32 command.
4391 => crc32 -v <address> <count> <crc32>
4393 Where address/count indicate a memory area
4394 and crc32 is the correct crc32 which the
4398 Add the "loopw" memory command. This only takes effect if
4399 the memory commands are activated globally (CONFIG_CMD_MEM).
4402 Add the "mdc" and "mwc" memory commands. These are cyclic
4407 This command will print 4 bytes (10,11,12,13) each 500 ms.
4409 => mwc.l 100 12345678 10
4410 This command will write 12345678 to address 100 all 10 ms.
4412 This only takes effect if the memory commands are activated
4413 globally (CONFIG_CMD_MEM).
4415 - CONFIG_SKIP_LOWLEVEL_INIT
4416 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4417 low level initializations (like setting up the memory
4418 controller) are omitted and/or U-Boot does not
4419 relocate itself into RAM.
4421 Normally this variable MUST NOT be defined. The only
4422 exception is when U-Boot is loaded (to RAM) by some
4423 other boot loader or by a debugger which performs
4424 these initializations itself.
4427 Modifies the behaviour of start.S when compiling a loader
4428 that is executed before the actual U-Boot. E.g. when
4429 compiling a NAND SPL.
4432 Modifies the behaviour of start.S when compiling a loader
4433 that is executed after the SPL and before the actual U-Boot.
4434 It is loaded by the SPL.
4436 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4437 Only for 85xx systems. If this variable is specified, the section
4438 .resetvec is not kept and the section .bootpg is placed in the
4439 previous 4k of the .text section.
4441 - CONFIG_ARCH_MAP_SYSMEM
4442 Generally U-Boot (and in particular the md command) uses
4443 effective address. It is therefore not necessary to regard
4444 U-Boot address as virtual addresses that need to be translated
4445 to physical addresses. However, sandbox requires this, since
4446 it maintains its own little RAM buffer which contains all
4447 addressable memory. This option causes some memory accesses
4448 to be mapped through map_sysmem() / unmap_sysmem().
4450 - CONFIG_USE_ARCH_MEMCPY
4451 CONFIG_USE_ARCH_MEMSET
4452 If these options are used a optimized version of memcpy/memset will
4453 be used if available. These functions may be faster under some
4454 conditions but may increase the binary size.
4456 - CONFIG_X86_RESET_VECTOR
4457 If defined, the x86 reset vector code is included. This is not
4458 needed when U-Boot is running from Coreboot.
4461 Defines the MPU clock speed (in MHz).
4463 NOTE : currently only supported on AM335x platforms.
4465 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4466 Enables the RTC32K OSC on AM33xx based plattforms
4468 Freescale QE/FMAN Firmware Support:
4469 -----------------------------------
4471 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4472 loading of "firmware", which is encoded in the QE firmware binary format.
4473 This firmware often needs to be loaded during U-Boot booting, so macros
4474 are used to identify the storage device (NOR flash, SPI, etc) and the address
4477 - CONFIG_SYS_QE_FMAN_FW_ADDR
4478 The address in the storage device where the firmware is located. The
4479 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4482 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4483 The maximum possible size of the firmware. The firmware binary format
4484 has a field that specifies the actual size of the firmware, but it
4485 might not be possible to read any part of the firmware unless some
4486 local storage is allocated to hold the entire firmware first.
4488 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4489 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4490 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4491 virtual address in NOR flash.
4493 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4494 Specifies that QE/FMAN firmware is located in NAND flash.
4495 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4497 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4498 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4499 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4501 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4502 Specifies that QE/FMAN firmware is located on the primary SPI
4503 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4505 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4506 Specifies that QE/FMAN firmware is located in the remote (master)
4507 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4508 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4509 window->master inbound window->master LAW->the ucode address in
4510 master's memory space.
4512 Building the Software:
4513 ======================
4515 Building U-Boot has been tested in several native build environments
4516 and in many different cross environments. Of course we cannot support
4517 all possibly existing versions of cross development tools in all
4518 (potentially obsolete) versions. In case of tool chain problems we
4519 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4520 which is extensively used to build and test U-Boot.
4522 If you are not using a native environment, it is assumed that you
4523 have GNU cross compiling tools available in your path. In this case,
4524 you must set the environment variable CROSS_COMPILE in your shell.
4525 Note that no changes to the Makefile or any other source files are
4526 necessary. For example using the ELDK on a 4xx CPU, please enter:
4528 $ CROSS_COMPILE=ppc_4xx-
4529 $ export CROSS_COMPILE
4531 Note: If you wish to generate Windows versions of the utilities in
4532 the tools directory you can use the MinGW toolchain
4533 (http://www.mingw.org). Set your HOST tools to the MinGW
4534 toolchain and execute 'make tools'. For example:
4536 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4538 Binaries such as tools/mkimage.exe will be created which can
4539 be executed on computers running Windows.
4541 U-Boot is intended to be simple to build. After installing the
4542 sources you must configure U-Boot for one specific board type. This
4547 where "NAME_config" is the name of one of the existing configu-
4548 rations; see boards.cfg for supported names.
4550 Note: for some board special configuration names may exist; check if
4551 additional information is available from the board vendor; for
4552 instance, the TQM823L systems are available without (standard)
4553 or with LCD support. You can select such additional "features"
4554 when choosing the configuration, i. e.
4557 - will configure for a plain TQM823L, i. e. no LCD support
4559 make TQM823L_LCD_config
4560 - will configure for a TQM823L with U-Boot console on LCD
4565 Finally, type "make all", and you should get some working U-Boot
4566 images ready for download to / installation on your system:
4568 - "u-boot.bin" is a raw binary image
4569 - "u-boot" is an image in ELF binary format
4570 - "u-boot.srec" is in Motorola S-Record format
4572 By default the build is performed locally and the objects are saved
4573 in the source directory. One of the two methods can be used to change
4574 this behavior and build U-Boot to some external directory:
4576 1. Add O= to the make command line invocations:
4578 make O=/tmp/build distclean
4579 make O=/tmp/build NAME_config
4580 make O=/tmp/build all
4582 2. Set environment variable BUILD_DIR to point to the desired location:
4584 export BUILD_DIR=/tmp/build
4589 Note that the command line "O=" setting overrides the BUILD_DIR environment
4593 Please be aware that the Makefiles assume you are using GNU make, so
4594 for instance on NetBSD you might need to use "gmake" instead of
4598 If the system board that you have is not listed, then you will need
4599 to port U-Boot to your hardware platform. To do this, follow these
4602 1. Add a new configuration option for your board to the toplevel
4603 "boards.cfg" file, using the existing entries as examples.
4604 Follow the instructions there to keep the boards in order.
4605 2. Create a new directory to hold your board specific code. Add any
4606 files you need. In your board directory, you will need at least
4607 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4608 3. Create a new configuration file "include/configs/<board>.h" for
4610 3. If you're porting U-Boot to a new CPU, then also create a new
4611 directory to hold your CPU specific code. Add any files you need.
4612 4. Run "make <board>_config" with your new name.
4613 5. Type "make", and you should get a working "u-boot.srec" file
4614 to be installed on your target system.
4615 6. Debug and solve any problems that might arise.
4616 [Of course, this last step is much harder than it sounds.]
4619 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4620 ==============================================================
4622 If you have modified U-Boot sources (for instance added a new board
4623 or support for new devices, a new CPU, etc.) you are expected to
4624 provide feedback to the other developers. The feedback normally takes
4625 the form of a "patch", i. e. a context diff against a certain (latest
4626 official or latest in the git repository) version of U-Boot sources.
4628 But before you submit such a patch, please verify that your modifi-
4629 cation did not break existing code. At least make sure that *ALL* of
4630 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4631 just run the "MAKEALL" script, which will configure and build U-Boot
4632 for ALL supported system. Be warned, this will take a while. You can
4633 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4634 environment variable to the script, i. e. to use the ELDK cross tools
4637 CROSS_COMPILE=ppc_8xx- MAKEALL
4639 or to build on a native PowerPC system you can type
4641 CROSS_COMPILE=' ' MAKEALL
4643 When using the MAKEALL script, the default behaviour is to build
4644 U-Boot in the source directory. This location can be changed by
4645 setting the BUILD_DIR environment variable. Also, for each target
4646 built, the MAKEALL script saves two log files (<target>.ERR and
4647 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4648 location can be changed by setting the MAKEALL_LOGDIR environment
4649 variable. For example:
4651 export BUILD_DIR=/tmp/build
4652 export MAKEALL_LOGDIR=/tmp/log
4653 CROSS_COMPILE=ppc_8xx- MAKEALL
4655 With the above settings build objects are saved in the /tmp/build,
4656 log files are saved in the /tmp/log and the source tree remains clean
4657 during the whole build process.
4660 See also "U-Boot Porting Guide" below.
4663 Monitor Commands - Overview:
4664 ============================
4666 go - start application at address 'addr'
4667 run - run commands in an environment variable
4668 bootm - boot application image from memory
4669 bootp - boot image via network using BootP/TFTP protocol
4670 bootz - boot zImage from memory
4671 tftpboot- boot image via network using TFTP protocol
4672 and env variables "ipaddr" and "serverip"
4673 (and eventually "gatewayip")
4674 tftpput - upload a file via network using TFTP protocol
4675 rarpboot- boot image via network using RARP/TFTP protocol
4676 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4677 loads - load S-Record file over serial line
4678 loadb - load binary file over serial line (kermit mode)
4680 mm - memory modify (auto-incrementing)
4681 nm - memory modify (constant address)
4682 mw - memory write (fill)
4684 cmp - memory compare
4685 crc32 - checksum calculation
4686 i2c - I2C sub-system
4687 sspi - SPI utility commands
4688 base - print or set address offset
4689 printenv- print environment variables
4690 setenv - set environment variables
4691 saveenv - save environment variables to persistent storage
4692 protect - enable or disable FLASH write protection
4693 erase - erase FLASH memory
4694 flinfo - print FLASH memory information
4695 nand - NAND memory operations (see doc/README.nand)
4696 bdinfo - print Board Info structure
4697 iminfo - print header information for application image
4698 coninfo - print console devices and informations
4699 ide - IDE sub-system
4700 loop - infinite loop on address range
4701 loopw - infinite write loop on address range
4702 mtest - simple RAM test
4703 icache - enable or disable instruction cache
4704 dcache - enable or disable data cache
4705 reset - Perform RESET of the CPU
4706 echo - echo args to console
4707 version - print monitor version
4708 help - print online help
4709 ? - alias for 'help'
4712 Monitor Commands - Detailed Description:
4713 ========================================
4717 For now: just type "help <command>".
4720 Environment Variables:
4721 ======================
4723 U-Boot supports user configuration using Environment Variables which
4724 can be made persistent by saving to Flash memory.
4726 Environment Variables are set using "setenv", printed using
4727 "printenv", and saved to Flash using "saveenv". Using "setenv"
4728 without a value can be used to delete a variable from the
4729 environment. As long as you don't save the environment you are
4730 working with an in-memory copy. In case the Flash area containing the
4731 environment is erased by accident, a default environment is provided.
4733 Some configuration options can be set using Environment Variables.
4735 List of environment variables (most likely not complete):
4737 baudrate - see CONFIG_BAUDRATE
4739 bootdelay - see CONFIG_BOOTDELAY
4741 bootcmd - see CONFIG_BOOTCOMMAND
4743 bootargs - Boot arguments when booting an RTOS image
4745 bootfile - Name of the image to load with TFTP
4747 bootm_low - Memory range available for image processing in the bootm
4748 command can be restricted. This variable is given as
4749 a hexadecimal number and defines lowest address allowed
4750 for use by the bootm command. See also "bootm_size"
4751 environment variable. Address defined by "bootm_low" is
4752 also the base of the initial memory mapping for the Linux
4753 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4756 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4757 This variable is given as a hexadecimal number and it
4758 defines the size of the memory region starting at base
4759 address bootm_low that is accessible by the Linux kernel
4760 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4761 as the default value if it is defined, and bootm_size is
4764 bootm_size - Memory range available for image processing in the bootm
4765 command can be restricted. This variable is given as
4766 a hexadecimal number and defines the size of the region
4767 allowed for use by the bootm command. See also "bootm_low"
4768 environment variable.
4770 updatefile - Location of the software update file on a TFTP server, used
4771 by the automatic software update feature. Please refer to
4772 documentation in doc/README.update for more details.
4774 autoload - if set to "no" (any string beginning with 'n'),
4775 "bootp" will just load perform a lookup of the
4776 configuration from the BOOTP server, but not try to
4777 load any image using TFTP
4779 autostart - if set to "yes", an image loaded using the "bootp",
4780 "rarpboot", "tftpboot" or "diskboot" commands will
4781 be automatically started (by internally calling
4784 If set to "no", a standalone image passed to the
4785 "bootm" command will be copied to the load address
4786 (and eventually uncompressed), but NOT be started.
4787 This can be used to load and uncompress arbitrary
4790 fdt_high - if set this restricts the maximum address that the
4791 flattened device tree will be copied into upon boot.
4792 For example, if you have a system with 1 GB memory
4793 at physical address 0x10000000, while Linux kernel
4794 only recognizes the first 704 MB as low memory, you
4795 may need to set fdt_high as 0x3C000000 to have the
4796 device tree blob be copied to the maximum address
4797 of the 704 MB low memory, so that Linux kernel can
4798 access it during the boot procedure.
4800 If this is set to the special value 0xFFFFFFFF then
4801 the fdt will not be copied at all on boot. For this
4802 to work it must reside in writable memory, have
4803 sufficient padding on the end of it for u-boot to
4804 add the information it needs into it, and the memory
4805 must be accessible by the kernel.
4807 fdtcontroladdr- if set this is the address of the control flattened
4808 device tree used by U-Boot when CONFIG_OF_CONTROL is
4811 i2cfast - (PPC405GP|PPC405EP only)
4812 if set to 'y' configures Linux I2C driver for fast
4813 mode (400kHZ). This environment variable is used in
4814 initialization code. So, for changes to be effective
4815 it must be saved and board must be reset.
4817 initrd_high - restrict positioning of initrd images:
4818 If this variable is not set, initrd images will be
4819 copied to the highest possible address in RAM; this
4820 is usually what you want since it allows for
4821 maximum initrd size. If for some reason you want to
4822 make sure that the initrd image is loaded below the
4823 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4824 variable to a value of "no" or "off" or "0".
4825 Alternatively, you can set it to a maximum upper
4826 address to use (U-Boot will still check that it
4827 does not overwrite the U-Boot stack and data).
4829 For instance, when you have a system with 16 MB
4830 RAM, and want to reserve 4 MB from use by Linux,
4831 you can do this by adding "mem=12M" to the value of
4832 the "bootargs" variable. However, now you must make
4833 sure that the initrd image is placed in the first
4834 12 MB as well - this can be done with
4836 setenv initrd_high 00c00000
4838 If you set initrd_high to 0xFFFFFFFF, this is an
4839 indication to U-Boot that all addresses are legal
4840 for the Linux kernel, including addresses in flash
4841 memory. In this case U-Boot will NOT COPY the
4842 ramdisk at all. This may be useful to reduce the
4843 boot time on your system, but requires that this
4844 feature is supported by your Linux kernel.
4846 ipaddr - IP address; needed for tftpboot command
4848 loadaddr - Default load address for commands like "bootp",
4849 "rarpboot", "tftpboot", "loadb" or "diskboot"
4851 loads_echo - see CONFIG_LOADS_ECHO
4853 serverip - TFTP server IP address; needed for tftpboot command
4855 bootretry - see CONFIG_BOOT_RETRY_TIME
4857 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4859 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4861 ethprime - controls which interface is used first.
4863 ethact - controls which interface is currently active.
4864 For example you can do the following
4866 => setenv ethact FEC
4867 => ping 192.168.0.1 # traffic sent on FEC
4868 => setenv ethact SCC
4869 => ping 10.0.0.1 # traffic sent on SCC
4871 ethrotate - When set to "no" U-Boot does not go through all
4872 available network interfaces.
4873 It just stays at the currently selected interface.
4875 netretry - When set to "no" each network operation will
4876 either succeed or fail without retrying.
4877 When set to "once" the network operation will
4878 fail when all the available network interfaces
4879 are tried once without success.
4880 Useful on scripts which control the retry operation
4883 npe_ucode - set load address for the NPE microcode
4885 silent_linux - If set then linux will be told to boot silently, by
4886 changing the console to be empty. If "yes" it will be
4887 made silent. If "no" it will not be made silent. If
4888 unset, then it will be made silent if the U-Boot console
4891 tftpsrcport - If this is set, the value is used for TFTP's
4894 tftpdstport - If this is set, the value is used for TFTP's UDP
4895 destination port instead of the Well Know Port 69.
4897 tftpblocksize - Block size to use for TFTP transfers; if not set,
4898 we use the TFTP server's default block size
4900 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4901 seconds, minimum value is 1000 = 1 second). Defines
4902 when a packet is considered to be lost so it has to
4903 be retransmitted. The default is 5000 = 5 seconds.
4904 Lowering this value may make downloads succeed
4905 faster in networks with high packet loss rates or
4906 with unreliable TFTP servers.
4908 vlan - When set to a value < 4095 the traffic over
4909 Ethernet is encapsulated/received over 802.1q
4912 The following image location variables contain the location of images
4913 used in booting. The "Image" column gives the role of the image and is
4914 not an environment variable name. The other columns are environment
4915 variable names. "File Name" gives the name of the file on a TFTP
4916 server, "RAM Address" gives the location in RAM the image will be
4917 loaded to, and "Flash Location" gives the image's address in NOR
4918 flash or offset in NAND flash.
4920 *Note* - these variables don't have to be defined for all boards, some
4921 boards currenlty use other variables for these purposes, and some
4922 boards use these variables for other purposes.
4924 Image File Name RAM Address Flash Location
4925 ----- --------- ----------- --------------
4926 u-boot u-boot u-boot_addr_r u-boot_addr
4927 Linux kernel bootfile kernel_addr_r kernel_addr
4928 device tree blob fdtfile fdt_addr_r fdt_addr
4929 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4931 The following environment variables may be used and automatically
4932 updated by the network boot commands ("bootp" and "rarpboot"),
4933 depending the information provided by your boot server:
4935 bootfile - see above
4936 dnsip - IP address of your Domain Name Server
4937 dnsip2 - IP address of your secondary Domain Name Server
4938 gatewayip - IP address of the Gateway (Router) to use
4939 hostname - Target hostname
4941 netmask - Subnet Mask
4942 rootpath - Pathname of the root filesystem on the NFS server
4943 serverip - see above
4946 There are two special Environment Variables:
4948 serial# - contains hardware identification information such
4949 as type string and/or serial number
4950 ethaddr - Ethernet address
4952 These variables can be set only once (usually during manufacturing of
4953 the board). U-Boot refuses to delete or overwrite these variables
4954 once they have been set once.
4957 Further special Environment Variables:
4959 ver - Contains the U-Boot version string as printed
4960 with the "version" command. This variable is
4961 readonly (see CONFIG_VERSION_VARIABLE).
4964 Please note that changes to some configuration parameters may take
4965 only effect after the next boot (yes, that's just like Windoze :-).
4968 Callback functions for environment variables:
4969 ---------------------------------------------
4971 For some environment variables, the behavior of u-boot needs to change
4972 when their values are changed. This functionailty allows functions to
4973 be associated with arbitrary variables. On creation, overwrite, or
4974 deletion, the callback will provide the opportunity for some side
4975 effect to happen or for the change to be rejected.
4977 The callbacks are named and associated with a function using the
4978 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4980 These callbacks are associated with variables in one of two ways. The
4981 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4982 in the board configuration to a string that defines a list of
4983 associations. The list must be in the following format:
4985 entry = variable_name[:callback_name]
4988 If the callback name is not specified, then the callback is deleted.
4989 Spaces are also allowed anywhere in the list.
4991 Callbacks can also be associated by defining the ".callbacks" variable
4992 with the same list format above. Any association in ".callbacks" will
4993 override any association in the static list. You can define
4994 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4995 ".callbacks" envirnoment variable in the default or embedded environment.
4998 Command Line Parsing:
4999 =====================
5001 There are two different command line parsers available with U-Boot:
5002 the old "simple" one, and the much more powerful "hush" shell:
5004 Old, simple command line parser:
5005 --------------------------------
5007 - supports environment variables (through setenv / saveenv commands)
5008 - several commands on one line, separated by ';'
5009 - variable substitution using "... ${name} ..." syntax
5010 - special characters ('$', ';') can be escaped by prefixing with '\',
5012 setenv bootcmd bootm \${address}
5013 - You can also escape text by enclosing in single apostrophes, for example:
5014 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5019 - similar to Bourne shell, with control structures like
5020 if...then...else...fi, for...do...done; while...do...done,
5021 until...do...done, ...
5022 - supports environment ("global") variables (through setenv / saveenv
5023 commands) and local shell variables (through standard shell syntax
5024 "name=value"); only environment variables can be used with "run"
5030 (1) If a command line (or an environment variable executed by a "run"
5031 command) contains several commands separated by semicolon, and
5032 one of these commands fails, then the remaining commands will be
5035 (2) If you execute several variables with one call to run (i. e.
5036 calling run with a list of variables as arguments), any failing
5037 command will cause "run" to terminate, i. e. the remaining
5038 variables are not executed.
5040 Note for Redundant Ethernet Interfaces:
5041 =======================================
5043 Some boards come with redundant Ethernet interfaces; U-Boot supports
5044 such configurations and is capable of automatic selection of a
5045 "working" interface when needed. MAC assignment works as follows:
5047 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5048 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5049 "eth1addr" (=>eth1), "eth2addr", ...
5051 If the network interface stores some valid MAC address (for instance
5052 in SROM), this is used as default address if there is NO correspon-
5053 ding setting in the environment; if the corresponding environment
5054 variable is set, this overrides the settings in the card; that means:
5056 o If the SROM has a valid MAC address, and there is no address in the
5057 environment, the SROM's address is used.
5059 o If there is no valid address in the SROM, and a definition in the
5060 environment exists, then the value from the environment variable is
5063 o If both the SROM and the environment contain a MAC address, and
5064 both addresses are the same, this MAC address is used.
5066 o If both the SROM and the environment contain a MAC address, and the
5067 addresses differ, the value from the environment is used and a
5070 o If neither SROM nor the environment contain a MAC address, an error
5073 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5074 will be programmed into hardware as part of the initialization process. This
5075 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5076 The naming convention is as follows:
5077 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5082 U-Boot is capable of booting (and performing other auxiliary operations on)
5083 images in two formats:
5085 New uImage format (FIT)
5086 -----------------------
5088 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5089 to Flattened Device Tree). It allows the use of images with multiple
5090 components (several kernels, ramdisks, etc.), with contents protected by
5091 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5097 Old image format is based on binary files which can be basically anything,
5098 preceded by a special header; see the definitions in include/image.h for
5099 details; basically, the header defines the following image properties:
5101 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5102 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5103 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5104 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5106 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5107 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5108 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5109 * Compression Type (uncompressed, gzip, bzip2)
5115 The header is marked by a special Magic Number, and both the header
5116 and the data portions of the image are secured against corruption by
5123 Although U-Boot should support any OS or standalone application
5124 easily, the main focus has always been on Linux during the design of
5127 U-Boot includes many features that so far have been part of some
5128 special "boot loader" code within the Linux kernel. Also, any
5129 "initrd" images to be used are no longer part of one big Linux image;
5130 instead, kernel and "initrd" are separate images. This implementation
5131 serves several purposes:
5133 - the same features can be used for other OS or standalone
5134 applications (for instance: using compressed images to reduce the
5135 Flash memory footprint)
5137 - it becomes much easier to port new Linux kernel versions because
5138 lots of low-level, hardware dependent stuff are done by U-Boot
5140 - the same Linux kernel image can now be used with different "initrd"
5141 images; of course this also means that different kernel images can
5142 be run with the same "initrd". This makes testing easier (you don't
5143 have to build a new "zImage.initrd" Linux image when you just
5144 change a file in your "initrd"). Also, a field-upgrade of the
5145 software is easier now.
5151 Porting Linux to U-Boot based systems:
5152 ---------------------------------------
5154 U-Boot cannot save you from doing all the necessary modifications to
5155 configure the Linux device drivers for use with your target hardware
5156 (no, we don't intend to provide a full virtual machine interface to
5159 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5161 Just make sure your machine specific header file (for instance
5162 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5163 Information structure as we define in include/asm-<arch>/u-boot.h,
5164 and make sure that your definition of IMAP_ADDR uses the same value
5165 as your U-Boot configuration in CONFIG_SYS_IMMR.
5168 Configuring the Linux kernel:
5169 -----------------------------
5171 No specific requirements for U-Boot. Make sure you have some root
5172 device (initial ramdisk, NFS) for your target system.
5175 Building a Linux Image:
5176 -----------------------
5178 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5179 not used. If you use recent kernel source, a new build target
5180 "uImage" will exist which automatically builds an image usable by
5181 U-Boot. Most older kernels also have support for a "pImage" target,
5182 which was introduced for our predecessor project PPCBoot and uses a
5183 100% compatible format.
5192 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5193 encapsulate a compressed Linux kernel image with header information,
5194 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5196 * build a standard "vmlinux" kernel image (in ELF binary format):
5198 * convert the kernel into a raw binary image:
5200 ${CROSS_COMPILE}-objcopy -O binary \
5201 -R .note -R .comment \
5202 -S vmlinux linux.bin
5204 * compress the binary image:
5208 * package compressed binary image for U-Boot:
5210 mkimage -A ppc -O linux -T kernel -C gzip \
5211 -a 0 -e 0 -n "Linux Kernel Image" \
5212 -d linux.bin.gz uImage
5215 The "mkimage" tool can also be used to create ramdisk images for use
5216 with U-Boot, either separated from the Linux kernel image, or
5217 combined into one file. "mkimage" encapsulates the images with a 64
5218 byte header containing information about target architecture,
5219 operating system, image type, compression method, entry points, time
5220 stamp, CRC32 checksums, etc.
5222 "mkimage" can be called in two ways: to verify existing images and
5223 print the header information, or to build new images.
5225 In the first form (with "-l" option) mkimage lists the information
5226 contained in the header of an existing U-Boot image; this includes
5227 checksum verification:
5229 tools/mkimage -l image
5230 -l ==> list image header information
5232 The second form (with "-d" option) is used to build a U-Boot image
5233 from a "data file" which is used as image payload:
5235 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5236 -n name -d data_file image
5237 -A ==> set architecture to 'arch'
5238 -O ==> set operating system to 'os'
5239 -T ==> set image type to 'type'
5240 -C ==> set compression type 'comp'
5241 -a ==> set load address to 'addr' (hex)
5242 -e ==> set entry point to 'ep' (hex)
5243 -n ==> set image name to 'name'
5244 -d ==> use image data from 'datafile'
5246 Right now, all Linux kernels for PowerPC systems use the same load
5247 address (0x00000000), but the entry point address depends on the
5250 - 2.2.x kernels have the entry point at 0x0000000C,
5251 - 2.3.x and later kernels have the entry point at 0x00000000.
5253 So a typical call to build a U-Boot image would read:
5255 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5256 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5257 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5258 > examples/uImage.TQM850L
5259 Image Name: 2.4.4 kernel for TQM850L
5260 Created: Wed Jul 19 02:34:59 2000
5261 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5262 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5263 Load Address: 0x00000000
5264 Entry Point: 0x00000000
5266 To verify the contents of the image (or check for corruption):
5268 -> tools/mkimage -l examples/uImage.TQM850L
5269 Image Name: 2.4.4 kernel for TQM850L
5270 Created: Wed Jul 19 02:34:59 2000
5271 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5272 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5273 Load Address: 0x00000000
5274 Entry Point: 0x00000000
5276 NOTE: for embedded systems where boot time is critical you can trade
5277 speed for memory and install an UNCOMPRESSED image instead: this
5278 needs more space in Flash, but boots much faster since it does not
5279 need to be uncompressed:
5281 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5282 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5283 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5284 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5285 > examples/uImage.TQM850L-uncompressed
5286 Image Name: 2.4.4 kernel for TQM850L
5287 Created: Wed Jul 19 02:34:59 2000
5288 Image Type: PowerPC Linux Kernel Image (uncompressed)
5289 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5290 Load Address: 0x00000000
5291 Entry Point: 0x00000000
5294 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5295 when your kernel is intended to use an initial ramdisk:
5297 -> tools/mkimage -n 'Simple Ramdisk Image' \
5298 > -A ppc -O linux -T ramdisk -C gzip \
5299 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5300 Image Name: Simple Ramdisk Image
5301 Created: Wed Jan 12 14:01:50 2000
5302 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5303 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5304 Load Address: 0x00000000
5305 Entry Point: 0x00000000
5307 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5308 option performs the converse operation of the mkimage's second form (the "-d"
5309 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5312 tools/dumpimage -i image -p position data_file
5313 -i ==> extract from the 'image' a specific 'data_file', \
5314 indexed by 'position'
5317 Installing a Linux Image:
5318 -------------------------
5320 To downloading a U-Boot image over the serial (console) interface,
5321 you must convert the image to S-Record format:
5323 objcopy -I binary -O srec examples/image examples/image.srec
5325 The 'objcopy' does not understand the information in the U-Boot
5326 image header, so the resulting S-Record file will be relative to
5327 address 0x00000000. To load it to a given address, you need to
5328 specify the target address as 'offset' parameter with the 'loads'
5331 Example: install the image to address 0x40100000 (which on the
5332 TQM8xxL is in the first Flash bank):
5334 => erase 40100000 401FFFFF
5340 ## Ready for S-Record download ...
5341 ~>examples/image.srec
5342 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5344 15989 15990 15991 15992
5345 [file transfer complete]
5347 ## Start Addr = 0x00000000
5350 You can check the success of the download using the 'iminfo' command;
5351 this includes a checksum verification so you can be sure no data
5352 corruption happened:
5356 ## Checking Image at 40100000 ...
5357 Image Name: 2.2.13 for initrd on TQM850L
5358 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5359 Data Size: 335725 Bytes = 327 kB = 0 MB
5360 Load Address: 00000000
5361 Entry Point: 0000000c
5362 Verifying Checksum ... OK
5368 The "bootm" command is used to boot an application that is stored in
5369 memory (RAM or Flash). In case of a Linux kernel image, the contents
5370 of the "bootargs" environment variable is passed to the kernel as
5371 parameters. You can check and modify this variable using the
5372 "printenv" and "setenv" commands:
5375 => printenv bootargs
5376 bootargs=root=/dev/ram
5378 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5380 => printenv bootargs
5381 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5384 ## Booting Linux kernel at 40020000 ...
5385 Image Name: 2.2.13 for NFS on TQM850L
5386 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5387 Data Size: 381681 Bytes = 372 kB = 0 MB
5388 Load Address: 00000000
5389 Entry Point: 0000000c
5390 Verifying Checksum ... OK
5391 Uncompressing Kernel Image ... OK
5392 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
5393 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5394 time_init: decrementer frequency = 187500000/60
5395 Calibrating delay loop... 49.77 BogoMIPS
5396 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5399 If you want to boot a Linux kernel with initial RAM disk, you pass
5400 the memory addresses of both the kernel and the initrd image (PPBCOOT
5401 format!) to the "bootm" command:
5403 => imi 40100000 40200000
5405 ## Checking Image at 40100000 ...
5406 Image Name: 2.2.13 for initrd on TQM850L
5407 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5408 Data Size: 335725 Bytes = 327 kB = 0 MB
5409 Load Address: 00000000
5410 Entry Point: 0000000c
5411 Verifying Checksum ... OK
5413 ## Checking Image at 40200000 ...
5414 Image Name: Simple Ramdisk Image
5415 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5416 Data Size: 566530 Bytes = 553 kB = 0 MB
5417 Load Address: 00000000
5418 Entry Point: 00000000
5419 Verifying Checksum ... OK
5421 => bootm 40100000 40200000
5422 ## Booting Linux kernel at 40100000 ...
5423 Image Name: 2.2.13 for initrd on TQM850L
5424 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5425 Data Size: 335725 Bytes = 327 kB = 0 MB
5426 Load Address: 00000000
5427 Entry Point: 0000000c
5428 Verifying Checksum ... OK
5429 Uncompressing Kernel Image ... OK
5430 ## Loading RAMDisk Image at 40200000 ...
5431 Image Name: Simple Ramdisk Image
5432 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5433 Data Size: 566530 Bytes = 553 kB = 0 MB
5434 Load Address: 00000000
5435 Entry Point: 00000000
5436 Verifying Checksum ... OK
5437 Loading Ramdisk ... OK
5438 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
5439 Boot arguments: root=/dev/ram
5440 time_init: decrementer frequency = 187500000/60
5441 Calibrating delay loop... 49.77 BogoMIPS
5443 RAMDISK: Compressed image found at block 0
5444 VFS: Mounted root (ext2 filesystem).
5448 Boot Linux and pass a flat device tree:
5451 First, U-Boot must be compiled with the appropriate defines. See the section
5452 titled "Linux Kernel Interface" above for a more in depth explanation. The
5453 following is an example of how to start a kernel and pass an updated
5459 oft=oftrees/mpc8540ads.dtb
5460 => tftp $oftaddr $oft
5461 Speed: 1000, full duplex
5463 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5464 Filename 'oftrees/mpc8540ads.dtb'.
5465 Load address: 0x300000
5468 Bytes transferred = 4106 (100a hex)
5469 => tftp $loadaddr $bootfile
5470 Speed: 1000, full duplex
5472 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5474 Load address: 0x200000
5475 Loading:############
5477 Bytes transferred = 1029407 (fb51f hex)
5482 => bootm $loadaddr - $oftaddr
5483 ## Booting image at 00200000 ...
5484 Image Name: Linux-2.6.17-dirty
5485 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5486 Data Size: 1029343 Bytes = 1005.2 kB
5487 Load Address: 00000000
5488 Entry Point: 00000000
5489 Verifying Checksum ... OK
5490 Uncompressing Kernel Image ... OK
5491 Booting using flat device tree at 0x300000
5492 Using MPC85xx ADS machine description
5493 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5497 More About U-Boot Image Types:
5498 ------------------------------
5500 U-Boot supports the following image types:
5502 "Standalone Programs" are directly runnable in the environment
5503 provided by U-Boot; it is expected that (if they behave
5504 well) you can continue to work in U-Boot after return from
5505 the Standalone Program.
5506 "OS Kernel Images" are usually images of some Embedded OS which
5507 will take over control completely. Usually these programs
5508 will install their own set of exception handlers, device
5509 drivers, set up the MMU, etc. - this means, that you cannot
5510 expect to re-enter U-Boot except by resetting the CPU.
5511 "RAMDisk Images" are more or less just data blocks, and their
5512 parameters (address, size) are passed to an OS kernel that is
5514 "Multi-File Images" contain several images, typically an OS
5515 (Linux) kernel image and one or more data images like
5516 RAMDisks. This construct is useful for instance when you want
5517 to boot over the network using BOOTP etc., where the boot
5518 server provides just a single image file, but you want to get
5519 for instance an OS kernel and a RAMDisk image.
5521 "Multi-File Images" start with a list of image sizes, each
5522 image size (in bytes) specified by an "uint32_t" in network
5523 byte order. This list is terminated by an "(uint32_t)0".
5524 Immediately after the terminating 0 follow the images, one by
5525 one, all aligned on "uint32_t" boundaries (size rounded up to
5526 a multiple of 4 bytes).
5528 "Firmware Images" are binary images containing firmware (like
5529 U-Boot or FPGA images) which usually will be programmed to
5532 "Script files" are command sequences that will be executed by
5533 U-Boot's command interpreter; this feature is especially
5534 useful when you configure U-Boot to use a real shell (hush)
5535 as command interpreter.
5537 Booting the Linux zImage:
5538 -------------------------
5540 On some platforms, it's possible to boot Linux zImage. This is done
5541 using the "bootz" command. The syntax of "bootz" command is the same
5542 as the syntax of "bootm" command.
5544 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5545 kernel with raw initrd images. The syntax is slightly different, the
5546 address of the initrd must be augmented by it's size, in the following
5547 format: "<initrd addres>:<initrd size>".
5553 One of the features of U-Boot is that you can dynamically load and
5554 run "standalone" applications, which can use some resources of
5555 U-Boot like console I/O functions or interrupt services.
5557 Two simple examples are included with the sources:
5562 'examples/hello_world.c' contains a small "Hello World" Demo
5563 application; it is automatically compiled when you build U-Boot.
5564 It's configured to run at address 0x00040004, so you can play with it
5568 ## Ready for S-Record download ...
5569 ~>examples/hello_world.srec
5570 1 2 3 4 5 6 7 8 9 10 11 ...
5571 [file transfer complete]
5573 ## Start Addr = 0x00040004
5575 => go 40004 Hello World! This is a test.
5576 ## Starting application at 0x00040004 ...
5587 Hit any key to exit ...
5589 ## Application terminated, rc = 0x0
5591 Another example, which demonstrates how to register a CPM interrupt
5592 handler with the U-Boot code, can be found in 'examples/timer.c'.
5593 Here, a CPM timer is set up to generate an interrupt every second.
5594 The interrupt service routine is trivial, just printing a '.'
5595 character, but this is just a demo program. The application can be
5596 controlled by the following keys:
5598 ? - print current values og the CPM Timer registers
5599 b - enable interrupts and start timer
5600 e - stop timer and disable interrupts
5601 q - quit application
5604 ## Ready for S-Record download ...
5605 ~>examples/timer.srec
5606 1 2 3 4 5 6 7 8 9 10 11 ...
5607 [file transfer complete]
5609 ## Start Addr = 0x00040004
5612 ## Starting application at 0x00040004 ...
5615 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5618 [q, b, e, ?] Set interval 1000000 us
5621 [q, b, e, ?] ........
5622 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5625 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5628 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5631 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5633 [q, b, e, ?] ...Stopping timer
5635 [q, b, e, ?] ## Application terminated, rc = 0x0
5641 Over time, many people have reported problems when trying to use the
5642 "minicom" terminal emulation program for serial download. I (wd)
5643 consider minicom to be broken, and recommend not to use it. Under
5644 Unix, I recommend to use C-Kermit for general purpose use (and
5645 especially for kermit binary protocol download ("loadb" command), and
5646 use "cu" for S-Record download ("loads" command). See
5647 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5648 for help with kermit.
5651 Nevertheless, if you absolutely want to use it try adding this
5652 configuration to your "File transfer protocols" section:
5654 Name Program Name U/D FullScr IO-Red. Multi
5655 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5656 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5662 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5663 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5665 Building requires a cross environment; it is known to work on
5666 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5667 need gmake since the Makefiles are not compatible with BSD make).
5668 Note that the cross-powerpc package does not install include files;
5669 attempting to build U-Boot will fail because <machine/ansi.h> is
5670 missing. This file has to be installed and patched manually:
5672 # cd /usr/pkg/cross/powerpc-netbsd/include
5674 # ln -s powerpc machine
5675 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5676 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5678 Native builds *don't* work due to incompatibilities between native
5679 and U-Boot include files.
5681 Booting assumes that (the first part of) the image booted is a
5682 stage-2 loader which in turn loads and then invokes the kernel
5683 proper. Loader sources will eventually appear in the NetBSD source
5684 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5685 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5688 Implementation Internals:
5689 =========================
5691 The following is not intended to be a complete description of every
5692 implementation detail. However, it should help to understand the
5693 inner workings of U-Boot and make it easier to port it to custom
5697 Initial Stack, Global Data:
5698 ---------------------------
5700 The implementation of U-Boot is complicated by the fact that U-Boot
5701 starts running out of ROM (flash memory), usually without access to
5702 system RAM (because the memory controller is not initialized yet).
5703 This means that we don't have writable Data or BSS segments, and BSS
5704 is not initialized as zero. To be able to get a C environment working
5705 at all, we have to allocate at least a minimal stack. Implementation
5706 options for this are defined and restricted by the CPU used: Some CPU
5707 models provide on-chip memory (like the IMMR area on MPC8xx and
5708 MPC826x processors), on others (parts of) the data cache can be
5709 locked as (mis-) used as memory, etc.
5711 Chris Hallinan posted a good summary of these issues to the
5712 U-Boot mailing list:
5714 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5715 From: "Chris Hallinan" <clh@net1plus.com>
5716 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5719 Correct me if I'm wrong, folks, but the way I understand it
5720 is this: Using DCACHE as initial RAM for Stack, etc, does not
5721 require any physical RAM backing up the cache. The cleverness
5722 is that the cache is being used as a temporary supply of
5723 necessary storage before the SDRAM controller is setup. It's
5724 beyond the scope of this list to explain the details, but you
5725 can see how this works by studying the cache architecture and
5726 operation in the architecture and processor-specific manuals.
5728 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5729 is another option for the system designer to use as an
5730 initial stack/RAM area prior to SDRAM being available. Either
5731 option should work for you. Using CS 4 should be fine if your
5732 board designers haven't used it for something that would
5733 cause you grief during the initial boot! It is frequently not
5736 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5737 with your processor/board/system design. The default value
5738 you will find in any recent u-boot distribution in
5739 walnut.h should work for you. I'd set it to a value larger
5740 than your SDRAM module. If you have a 64MB SDRAM module, set
5741 it above 400_0000. Just make sure your board has no resources
5742 that are supposed to respond to that address! That code in
5743 start.S has been around a while and should work as is when
5744 you get the config right.
5749 It is essential to remember this, since it has some impact on the C
5750 code for the initialization procedures:
5752 * Initialized global data (data segment) is read-only. Do not attempt
5755 * Do not use any uninitialized global data (or implicitely initialized
5756 as zero data - BSS segment) at all - this is undefined, initiali-
5757 zation is performed later (when relocating to RAM).
5759 * Stack space is very limited. Avoid big data buffers or things like
5762 Having only the stack as writable memory limits means we cannot use
5763 normal global data to share information beween the code. But it
5764 turned out that the implementation of U-Boot can be greatly
5765 simplified by making a global data structure (gd_t) available to all
5766 functions. We could pass a pointer to this data as argument to _all_
5767 functions, but this would bloat the code. Instead we use a feature of
5768 the GCC compiler (Global Register Variables) to share the data: we
5769 place a pointer (gd) to the global data into a register which we
5770 reserve for this purpose.
5772 When choosing a register for such a purpose we are restricted by the
5773 relevant (E)ABI specifications for the current architecture, and by
5774 GCC's implementation.
5776 For PowerPC, the following registers have specific use:
5778 R2: reserved for system use
5779 R3-R4: parameter passing and return values
5780 R5-R10: parameter passing
5781 R13: small data area pointer
5785 (U-Boot also uses R12 as internal GOT pointer. r12
5786 is a volatile register so r12 needs to be reset when
5787 going back and forth between asm and C)
5789 ==> U-Boot will use R2 to hold a pointer to the global data
5791 Note: on PPC, we could use a static initializer (since the
5792 address of the global data structure is known at compile time),
5793 but it turned out that reserving a register results in somewhat
5794 smaller code - although the code savings are not that big (on
5795 average for all boards 752 bytes for the whole U-Boot image,
5796 624 text + 127 data).
5798 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5799 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5801 ==> U-Boot will use P3 to hold a pointer to the global data
5803 On ARM, the following registers are used:
5805 R0: function argument word/integer result
5806 R1-R3: function argument word
5807 R9: platform specific
5808 R10: stack limit (used only if stack checking is enabled)
5809 R11: argument (frame) pointer
5810 R12: temporary workspace
5813 R15: program counter
5815 ==> U-Boot will use R9 to hold a pointer to the global data
5817 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5819 On Nios II, the ABI is documented here:
5820 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5822 ==> U-Boot will use gp to hold a pointer to the global data
5824 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5825 to access small data sections, so gp is free.
5827 On NDS32, the following registers are used:
5829 R0-R1: argument/return
5831 R15: temporary register for assembler
5832 R16: trampoline register
5833 R28: frame pointer (FP)
5834 R29: global pointer (GP)
5835 R30: link register (LP)
5836 R31: stack pointer (SP)
5837 PC: program counter (PC)
5839 ==> U-Boot will use R10 to hold a pointer to the global data
5841 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5842 or current versions of GCC may "optimize" the code too much.
5847 U-Boot runs in system state and uses physical addresses, i.e. the
5848 MMU is not used either for address mapping nor for memory protection.
5850 The available memory is mapped to fixed addresses using the memory
5851 controller. In this process, a contiguous block is formed for each
5852 memory type (Flash, SDRAM, SRAM), even when it consists of several
5853 physical memory banks.
5855 U-Boot is installed in the first 128 kB of the first Flash bank (on
5856 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5857 booting and sizing and initializing DRAM, the code relocates itself
5858 to the upper end of DRAM. Immediately below the U-Boot code some
5859 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5860 configuration setting]. Below that, a structure with global Board
5861 Info data is placed, followed by the stack (growing downward).
5863 Additionally, some exception handler code is copied to the low 8 kB
5864 of DRAM (0x00000000 ... 0x00001FFF).
5866 So a typical memory configuration with 16 MB of DRAM could look like
5869 0x0000 0000 Exception Vector code
5872 0x0000 2000 Free for Application Use
5878 0x00FB FF20 Monitor Stack (Growing downward)
5879 0x00FB FFAC Board Info Data and permanent copy of global data
5880 0x00FC 0000 Malloc Arena
5883 0x00FE 0000 RAM Copy of Monitor Code
5884 ... eventually: LCD or video framebuffer
5885 ... eventually: pRAM (Protected RAM - unchanged by reset)
5886 0x00FF FFFF [End of RAM]
5889 System Initialization:
5890 ----------------------
5892 In the reset configuration, U-Boot starts at the reset entry point
5893 (on most PowerPC systems at address 0x00000100). Because of the reset
5894 configuration for CS0# this is a mirror of the onboard Flash memory.
5895 To be able to re-map memory U-Boot then jumps to its link address.
5896 To be able to implement the initialization code in C, a (small!)
5897 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5898 which provide such a feature like MPC8xx or MPC8260), or in a locked
5899 part of the data cache. After that, U-Boot initializes the CPU core,
5900 the caches and the SIU.
5902 Next, all (potentially) available memory banks are mapped using a
5903 preliminary mapping. For example, we put them on 512 MB boundaries
5904 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5905 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5906 programmed for SDRAM access. Using the temporary configuration, a
5907 simple memory test is run that determines the size of the SDRAM
5910 When there is more than one SDRAM bank, and the banks are of
5911 different size, the largest is mapped first. For equal size, the first
5912 bank (CS2#) is mapped first. The first mapping is always for address
5913 0x00000000, with any additional banks following immediately to create
5914 contiguous memory starting from 0.
5916 Then, the monitor installs itself at the upper end of the SDRAM area
5917 and allocates memory for use by malloc() and for the global Board
5918 Info data; also, the exception vector code is copied to the low RAM
5919 pages, and the final stack is set up.
5921 Only after this relocation will you have a "normal" C environment;
5922 until that you are restricted in several ways, mostly because you are
5923 running from ROM, and because the code will have to be relocated to a
5927 U-Boot Porting Guide:
5928 ----------------------
5930 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5934 int main(int argc, char *argv[])
5936 sighandler_t no_more_time;
5938 signal(SIGALRM, no_more_time);
5939 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5941 if (available_money > available_manpower) {
5942 Pay consultant to port U-Boot;
5946 Download latest U-Boot source;
5948 Subscribe to u-boot mailing list;
5951 email("Hi, I am new to U-Boot, how do I get started?");
5954 Read the README file in the top level directory;
5955 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5956 Read applicable doc/*.README;
5957 Read the source, Luke;
5958 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5961 if (available_money > toLocalCurrency ($2500))
5964 Add a lot of aggravation and time;
5966 if (a similar board exists) { /* hopefully... */
5967 cp -a board/<similar> board/<myboard>
5968 cp include/configs/<similar>.h include/configs/<myboard>.h
5970 Create your own board support subdirectory;
5971 Create your own board include/configs/<myboard>.h file;
5973 Edit new board/<myboard> files
5974 Edit new include/configs/<myboard>.h
5979 Add / modify source code;
5983 email("Hi, I am having problems...");
5985 Send patch file to the U-Boot email list;
5986 if (reasonable critiques)
5987 Incorporate improvements from email list code review;
5989 Defend code as written;
5995 void no_more_time (int sig)
6004 All contributions to U-Boot should conform to the Linux kernel
6005 coding style; see the file "Documentation/CodingStyle" and the script
6006 "scripts/Lindent" in your Linux kernel source directory.
6008 Source files originating from a different project (for example the
6009 MTD subsystem) are generally exempt from these guidelines and are not
6010 reformated to ease subsequent migration to newer versions of those
6013 Please note that U-Boot is implemented in C (and to some small parts in
6014 Assembler); no C++ is used, so please do not use C++ style comments (//)
6017 Please also stick to the following formatting rules:
6018 - remove any trailing white space
6019 - use TAB characters for indentation and vertical alignment, not spaces
6020 - make sure NOT to use DOS '\r\n' line feeds
6021 - do not add more than 2 consecutive empty lines to source files
6022 - do not add trailing empty lines to source files
6024 Submissions which do not conform to the standards may be returned
6025 with a request to reformat the changes.
6031 Since the number of patches for U-Boot is growing, we need to
6032 establish some rules. Submissions which do not conform to these rules
6033 may be rejected, even when they contain important and valuable stuff.
6035 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6037 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6038 see http://lists.denx.de/mailman/listinfo/u-boot
6040 When you send a patch, please include the following information with
6043 * For bug fixes: a description of the bug and how your patch fixes
6044 this bug. Please try to include a way of demonstrating that the
6045 patch actually fixes something.
6047 * For new features: a description of the feature and your
6050 * A CHANGELOG entry as plaintext (separate from the patch)
6052 * For major contributions, your entry to the CREDITS file
6054 * When you add support for a new board, don't forget to add a
6055 maintainer e-mail address to the boards.cfg file, too.
6057 * If your patch adds new configuration options, don't forget to
6058 document these in the README file.
6060 * The patch itself. If you are using git (which is *strongly*
6061 recommended) you can easily generate the patch using the
6062 "git format-patch". If you then use "git send-email" to send it to
6063 the U-Boot mailing list, you will avoid most of the common problems
6064 with some other mail clients.
6066 If you cannot use git, use "diff -purN OLD NEW". If your version of
6067 diff does not support these options, then get the latest version of
6070 The current directory when running this command shall be the parent
6071 directory of the U-Boot source tree (i. e. please make sure that
6072 your patch includes sufficient directory information for the
6075 We prefer patches as plain text. MIME attachments are discouraged,
6076 and compressed attachments must not be used.
6078 * If one logical set of modifications affects or creates several
6079 files, all these changes shall be submitted in a SINGLE patch file.
6081 * Changesets that contain different, unrelated modifications shall be
6082 submitted as SEPARATE patches, one patch per changeset.
6087 * Before sending the patch, run the MAKEALL script on your patched
6088 source tree and make sure that no errors or warnings are reported
6089 for any of the boards.
6091 * Keep your modifications to the necessary minimum: A patch
6092 containing several unrelated changes or arbitrary reformats will be
6093 returned with a request to re-formatting / split it.
6095 * If you modify existing code, make sure that your new code does not
6096 add to the memory footprint of the code ;-) Small is beautiful!
6097 When adding new features, these should compile conditionally only
6098 (using #ifdef), and the resulting code with the new feature
6099 disabled must not need more memory than the old code without your
6102 * Remember that there is a size limit of 100 kB per message on the
6103 u-boot mailing list. Bigger patches will be moderated. If they are
6104 reasonable and not too big, they will be acknowledged. But patches
6105 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob