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_DDR_EMU
427 Specify emulator support for DDR. Some DDR features such as
428 deskew training are not available.
430 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
436 - Intel Monahans options:
437 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
439 Defines the Monahans run mode to oscillator
440 ratio. Valid values are 8, 16, 24, 31. The core
441 frequency is this value multiplied by 13 MHz.
443 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
445 Defines the Monahans turbo mode to oscillator
446 ratio. Valid values are 1 (default if undefined) and
447 2. The core frequency as calculated above is multiplied
451 CONFIG_SYS_INIT_SP_OFFSET
453 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
454 pointer. This is needed for the temporary stack before
457 CONFIG_SYS_MIPS_CACHE_MODE
459 Cache operation mode for the MIPS CPU.
460 See also arch/mips/include/asm/mipsregs.h.
462 CONF_CM_CACHABLE_NO_WA
465 CONF_CM_CACHABLE_NONCOHERENT
469 CONF_CM_CACHABLE_ACCELERATED
471 CONFIG_SYS_XWAY_EBU_BOOTCFG
473 Special option for Lantiq XWAY SoCs for booting from NOR flash.
474 See also arch/mips/cpu/mips32/start.S.
476 CONFIG_XWAY_SWAP_BYTES
478 Enable compilation of tools/xway-swap-bytes needed for Lantiq
479 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
480 be swapped if a flash programmer is used.
483 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
485 Select high exception vectors of the ARM core, e.g., do not
486 clear the V bit of the c1 register of CP15.
488 CONFIG_SYS_THUMB_BUILD
490 Use this flag to build U-Boot using the Thumb instruction
491 set for ARM architectures. Thumb instruction set provides
492 better code density. For ARM architectures that support
493 Thumb2 this flag will result in Thumb2 code generated by
496 CONFIG_ARM_ERRATA_716044
497 CONFIG_ARM_ERRATA_742230
498 CONFIG_ARM_ERRATA_743622
499 CONFIG_ARM_ERRATA_751472
501 If set, the workarounds for these ARM errata are applied early
502 during U-Boot startup. Note that these options force the
503 workarounds to be applied; no CPU-type/version detection
504 exists, unlike the similar options in the Linux kernel. Do not
505 set these options unless they apply!
510 The frequency of the timer returned by get_timer().
511 get_timer() must operate in milliseconds and this CONFIG
512 option must be set to 1000.
514 - Linux Kernel Interface:
517 U-Boot stores all clock information in Hz
518 internally. For binary compatibility with older Linux
519 kernels (which expect the clocks passed in the
520 bd_info data to be in MHz) the environment variable
521 "clocks_in_mhz" can be defined so that U-Boot
522 converts clock data to MHZ before passing it to the
524 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
525 "clocks_in_mhz=1" is automatically included in the
528 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
530 When transferring memsize parameter to linux, some versions
531 expect it to be in bytes, others in MB.
532 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
536 New kernel versions are expecting firmware settings to be
537 passed using flattened device trees (based on open firmware
541 * New libfdt-based support
542 * Adds the "fdt" command
543 * The bootm command automatically updates the fdt
545 OF_CPU - The proper name of the cpus node (only required for
546 MPC512X and MPC5xxx based boards).
547 OF_SOC - The proper name of the soc node (only required for
548 MPC512X and MPC5xxx based boards).
549 OF_TBCLK - The timebase frequency.
550 OF_STDOUT_PATH - The path to the console device
552 boards with QUICC Engines require OF_QE to set UCC MAC
555 CONFIG_OF_BOARD_SETUP
557 Board code has addition modification that it wants to make
558 to the flat device tree before handing it off to the kernel
562 This define fills in the correct boot CPU in the boot
563 param header, the default value is zero if undefined.
567 U-Boot can detect if an IDE device is present or not.
568 If not, and this new config option is activated, U-Boot
569 removes the ATA node from the DTS before booting Linux,
570 so the Linux IDE driver does not probe the device and
571 crash. This is needed for buggy hardware (uc101) where
572 no pull down resistor is connected to the signal IDE5V_DD7.
574 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
576 This setting is mandatory for all boards that have only one
577 machine type and must be used to specify the machine type
578 number as it appears in the ARM machine registry
579 (see http://www.arm.linux.org.uk/developer/machines/).
580 Only boards that have multiple machine types supported
581 in a single configuration file and the machine type is
582 runtime discoverable, do not have to use this setting.
584 - vxWorks boot parameters:
586 bootvx constructs a valid bootline using the following
587 environments variables: bootfile, ipaddr, serverip, hostname.
588 It loads the vxWorks image pointed bootfile.
590 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
591 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
592 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
593 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
595 CONFIG_SYS_VXWORKS_ADD_PARAMS
597 Add it at the end of the bootline. E.g "u=username pw=secret"
599 Note: If a "bootargs" environment is defined, it will overwride
600 the defaults discussed just above.
602 - Cache Configuration:
603 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
604 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
605 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
607 - Cache Configuration for ARM:
608 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
610 CONFIG_SYS_PL310_BASE - Physical base address of PL310
611 controller register space
616 Define this if you want support for Amba PrimeCell PL010 UARTs.
620 Define this if you want support for Amba PrimeCell PL011 UARTs.
624 If you have Amba PrimeCell PL011 UARTs, set this variable to
625 the clock speed of the UARTs.
629 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
630 define this to a list of base addresses for each (supported)
631 port. See e.g. include/configs/versatile.h
633 CONFIG_PL011_SERIAL_RLCR
635 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
636 have separate receive and transmit line control registers. Set
637 this variable to initialize the extra register.
639 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
641 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
642 boot loader that has already initialized the UART. Define this
643 variable to flush the UART at init time.
647 Depending on board, define exactly one serial port
648 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
649 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
650 console by defining CONFIG_8xx_CONS_NONE
652 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
653 port routines must be defined elsewhere
654 (i.e. serial_init(), serial_getc(), ...)
657 Enables console device for a color framebuffer. Needs following
658 defines (cf. smiLynxEM, i8042)
659 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
661 VIDEO_HW_RECTFILL graphic chip supports
664 VIDEO_HW_BITBLT graphic chip supports
665 bit-blit (cf. smiLynxEM)
666 VIDEO_VISIBLE_COLS visible pixel columns
668 VIDEO_VISIBLE_ROWS visible pixel rows
669 VIDEO_PIXEL_SIZE bytes per pixel
670 VIDEO_DATA_FORMAT graphic data format
671 (0-5, cf. cfb_console.c)
672 VIDEO_FB_ADRS framebuffer address
673 VIDEO_KBD_INIT_FCT keyboard int fct
674 (i.e. i8042_kbd_init())
675 VIDEO_TSTC_FCT test char fct
677 VIDEO_GETC_FCT get char fct
679 CONFIG_CONSOLE_CURSOR cursor drawing on/off
680 (requires blink timer
682 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
683 CONFIG_CONSOLE_TIME display time/date info in
685 (requires CONFIG_CMD_DATE)
686 CONFIG_VIDEO_LOGO display Linux logo in
688 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
689 linux_logo.h for logo.
690 Requires CONFIG_VIDEO_LOGO
691 CONFIG_CONSOLE_EXTRA_INFO
692 additional board info beside
695 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
696 a limited number of ANSI escape sequences (cursor control,
697 erase functions and limited graphics rendition control).
699 When CONFIG_CFB_CONSOLE is defined, video console is
700 default i/o. Serial console can be forced with
701 environment 'console=serial'.
703 When CONFIG_SILENT_CONSOLE is defined, all console
704 messages (by U-Boot and Linux!) can be silenced with
705 the "silent" environment variable. See
706 doc/README.silent for more information.
709 CONFIG_BAUDRATE - in bps
710 Select one of the baudrates listed in
711 CONFIG_SYS_BAUDRATE_TABLE, see below.
712 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
714 - Console Rx buffer length
715 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
716 the maximum receive buffer length for the SMC.
717 This option is actual only for 82xx and 8xx possible.
718 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
719 must be defined, to setup the maximum idle timeout for
722 - Pre-Console Buffer:
723 Prior to the console being initialised (i.e. serial UART
724 initialised etc) all console output is silently discarded.
725 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
726 buffer any console messages prior to the console being
727 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
728 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
729 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
730 bytes are output before the console is initialised, the
731 earlier bytes are discarded.
733 'Sane' compilers will generate smaller code if
734 CONFIG_PRE_CON_BUF_SZ is a power of 2
736 - Safe printf() functions
737 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
738 the printf() functions. These are defined in
739 include/vsprintf.h and include snprintf(), vsnprintf() and
740 so on. Code size increase is approximately 300-500 bytes.
741 If this option is not given then these functions will
742 silently discard their buffer size argument - this means
743 you are not getting any overflow checking in this case.
745 - Boot Delay: CONFIG_BOOTDELAY - in seconds
746 Delay before automatically booting the default image;
747 set to -1 to disable autoboot.
748 set to -2 to autoboot with no delay and not check for abort
749 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
751 See doc/README.autoboot for these options that
752 work with CONFIG_BOOTDELAY. None are required.
753 CONFIG_BOOT_RETRY_TIME
754 CONFIG_BOOT_RETRY_MIN
755 CONFIG_AUTOBOOT_KEYED
756 CONFIG_AUTOBOOT_PROMPT
757 CONFIG_AUTOBOOT_DELAY_STR
758 CONFIG_AUTOBOOT_STOP_STR
759 CONFIG_AUTOBOOT_DELAY_STR2
760 CONFIG_AUTOBOOT_STOP_STR2
761 CONFIG_ZERO_BOOTDELAY_CHECK
762 CONFIG_RESET_TO_RETRY
766 Only needed when CONFIG_BOOTDELAY is enabled;
767 define a command string that is automatically executed
768 when no character is read on the console interface
769 within "Boot Delay" after reset.
772 This can be used to pass arguments to the bootm
773 command. The value of CONFIG_BOOTARGS goes into the
774 environment value "bootargs".
776 CONFIG_RAMBOOT and CONFIG_NFSBOOT
777 The value of these goes into the environment as
778 "ramboot" and "nfsboot" respectively, and can be used
779 as a convenience, when switching between booting from
785 When this option is #defined, the existence of the
786 environment variable "preboot" will be checked
787 immediately before starting the CONFIG_BOOTDELAY
788 countdown and/or running the auto-boot command resp.
789 entering interactive mode.
791 This feature is especially useful when "preboot" is
792 automatically generated or modified. For an example
793 see the LWMON board specific code: here "preboot" is
794 modified when the user holds down a certain
795 combination of keys on the (special) keyboard when
798 - Serial Download Echo Mode:
800 If defined to 1, all characters received during a
801 serial download (using the "loads" command) are
802 echoed back. This might be needed by some terminal
803 emulations (like "cu"), but may as well just take
804 time on others. This setting #define's the initial
805 value of the "loads_echo" environment variable.
807 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
809 Select one of the baudrates listed in
810 CONFIG_SYS_BAUDRATE_TABLE, see below.
813 Monitor commands can be included or excluded
814 from the build by using the #include files
815 <config_cmd_all.h> and #undef'ing unwanted
816 commands, or using <config_cmd_default.h>
817 and augmenting with additional #define's
820 The default command configuration includes all commands
821 except those marked below with a "*".
823 CONFIG_CMD_ASKENV * ask for env variable
824 CONFIG_CMD_BDI bdinfo
825 CONFIG_CMD_BEDBUG * Include BedBug Debugger
826 CONFIG_CMD_BMP * BMP support
827 CONFIG_CMD_BSP * Board specific commands
828 CONFIG_CMD_BOOTD bootd
829 CONFIG_CMD_CACHE * icache, dcache
830 CONFIG_CMD_CONSOLE coninfo
831 CONFIG_CMD_CRC32 * crc32
832 CONFIG_CMD_DATE * support for RTC, date/time...
833 CONFIG_CMD_DHCP * DHCP support
834 CONFIG_CMD_DIAG * Diagnostics
835 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
836 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
837 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
838 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
839 CONFIG_CMD_DTT * Digital Therm and Thermostat
840 CONFIG_CMD_ECHO echo arguments
841 CONFIG_CMD_EDITENV edit env variable
842 CONFIG_CMD_EEPROM * EEPROM read/write support
843 CONFIG_CMD_ELF * bootelf, bootvx
844 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
845 CONFIG_CMD_ENV_FLAGS * display details about env flags
846 CONFIG_CMD_EXPORTENV * export the environment
847 CONFIG_CMD_EXT2 * ext2 command support
848 CONFIG_CMD_EXT4 * ext4 command support
849 CONFIG_CMD_SAVEENV saveenv
850 CONFIG_CMD_FDC * Floppy Disk Support
851 CONFIG_CMD_FAT * FAT command support
852 CONFIG_CMD_FDOS * Dos diskette Support
853 CONFIG_CMD_FLASH flinfo, erase, protect
854 CONFIG_CMD_FPGA FPGA device initialization support
855 CONFIG_CMD_FUSE * Device fuse support
856 CONFIG_CMD_GETTIME * Get time since boot
857 CONFIG_CMD_GO * the 'go' command (exec code)
858 CONFIG_CMD_GREPENV * search environment
859 CONFIG_CMD_HASH * calculate hash / digest
860 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
861 CONFIG_CMD_I2C * I2C serial bus support
862 CONFIG_CMD_IDE * IDE harddisk support
863 CONFIG_CMD_IMI iminfo
864 CONFIG_CMD_IMLS List all images found in NOR flash
865 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
866 CONFIG_CMD_IMMAP * IMMR dump support
867 CONFIG_CMD_IMPORTENV * import an environment
868 CONFIG_CMD_INI * import data from an ini file into the env
869 CONFIG_CMD_IRQ * irqinfo
870 CONFIG_CMD_ITEST Integer/string test of 2 values
871 CONFIG_CMD_JFFS2 * JFFS2 Support
872 CONFIG_CMD_KGDB * kgdb
873 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
874 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
876 CONFIG_CMD_LOADB loadb
877 CONFIG_CMD_LOADS loads
878 CONFIG_CMD_MD5SUM * print md5 message digest
879 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
880 CONFIG_CMD_MEMINFO * Display detailed memory information
881 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
883 CONFIG_CMD_MEMTEST * mtest
884 CONFIG_CMD_MISC Misc functions like sleep etc
885 CONFIG_CMD_MMC * MMC memory mapped support
886 CONFIG_CMD_MII * MII utility commands
887 CONFIG_CMD_MTDPARTS * MTD partition support
888 CONFIG_CMD_NAND * NAND support
889 CONFIG_CMD_NET bootp, tftpboot, rarpboot
890 CONFIG_CMD_NFS NFS support
891 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
892 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
893 CONFIG_CMD_PCI * pciinfo
894 CONFIG_CMD_PCMCIA * PCMCIA support
895 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
897 CONFIG_CMD_PORTIO * Port I/O
898 CONFIG_CMD_READ * Read raw data from partition
899 CONFIG_CMD_REGINFO * Register dump
900 CONFIG_CMD_RUN run command in env variable
901 CONFIG_CMD_SANDBOX * sb command to access sandbox features
902 CONFIG_CMD_SAVES * save S record dump
903 CONFIG_CMD_SCSI * SCSI Support
904 CONFIG_CMD_SDRAM * print SDRAM configuration information
905 (requires CONFIG_CMD_I2C)
906 CONFIG_CMD_SETGETDCR Support for DCR Register access
908 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
909 CONFIG_CMD_SHA1SUM * print sha1 memory digest
910 (requires CONFIG_CMD_MEMORY)
911 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
912 CONFIG_CMD_SOURCE "source" command Support
913 CONFIG_CMD_SPI * SPI serial bus support
914 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
915 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
916 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
917 CONFIG_CMD_TIMER * access to the system tick timer
918 CONFIG_CMD_USB * USB support
919 CONFIG_CMD_CDP * Cisco Discover Protocol support
920 CONFIG_CMD_MFSL * Microblaze FSL support
921 CONFIG_CMD_XIMG Load part of Multi Image
924 EXAMPLE: If you want all functions except of network
925 support you can write:
927 #include "config_cmd_all.h"
928 #undef CONFIG_CMD_NET
931 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
933 Note: Don't enable the "icache" and "dcache" commands
934 (configuration option CONFIG_CMD_CACHE) unless you know
935 what you (and your U-Boot users) are doing. Data
936 cache cannot be enabled on systems like the 8xx or
937 8260 (where accesses to the IMMR region must be
938 uncached), and it cannot be disabled on all other
939 systems where we (mis-) use the data cache to hold an
940 initial stack and some data.
943 XXX - this list needs to get updated!
945 - Regular expression support:
947 If this variable is defined, U-Boot is linked against
948 the SLRE (Super Light Regular Expression) library,
949 which adds regex support to some commands, as for
950 example "env grep" and "setexpr".
954 If this variable is defined, U-Boot will use a device tree
955 to configure its devices, instead of relying on statically
956 compiled #defines in the board file. This option is
957 experimental and only available on a few boards. The device
958 tree is available in the global data as gd->fdt_blob.
960 U-Boot needs to get its device tree from somewhere. This can
961 be done using one of the two options below:
964 If this variable is defined, U-Boot will embed a device tree
965 binary in its image. This device tree file should be in the
966 board directory and called <soc>-<board>.dts. The binary file
967 is then picked up in board_init_f() and made available through
968 the global data structure as gd->blob.
971 If this variable is defined, U-Boot will build a device tree
972 binary. It will be called u-boot.dtb. Architecture-specific
973 code will locate it at run-time. Generally this works by:
975 cat u-boot.bin u-boot.dtb >image.bin
977 and in fact, U-Boot does this for you, creating a file called
978 u-boot-dtb.bin which is useful in the common case. You can
979 still use the individual files if you need something more
984 If this variable is defined, it enables watchdog
985 support for the SoC. There must be support in the SoC
986 specific code for a watchdog. For the 8xx and 8260
987 CPUs, the SIU Watchdog feature is enabled in the SYPCR
988 register. When supported for a specific SoC is
989 available, then no further board specific code should
993 When using a watchdog circuitry external to the used
994 SoC, then define this variable and provide board
995 specific code for the "hw_watchdog_reset" function.
998 CONFIG_VERSION_VARIABLE
999 If this variable is defined, an environment variable
1000 named "ver" is created by U-Boot showing the U-Boot
1001 version as printed by the "version" command.
1002 Any change to this variable will be reverted at the
1007 When CONFIG_CMD_DATE is selected, the type of the RTC
1008 has to be selected, too. Define exactly one of the
1011 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1012 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1013 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1014 CONFIG_RTC_MC146818 - use MC146818 RTC
1015 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1016 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1017 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1018 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1019 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1020 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1021 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1022 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1025 Note that if the RTC uses I2C, then the I2C interface
1026 must also be configured. See I2C Support, below.
1029 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1030 CONFIG_PCA953X_INFO - enable pca953x info command
1032 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1033 chip-ngpio pairs that tell the PCA953X driver the number of
1034 pins supported by a particular chip.
1036 Note that if the GPIO device uses I2C, then the I2C interface
1037 must also be configured. See I2C Support, below.
1039 - Timestamp Support:
1041 When CONFIG_TIMESTAMP is selected, the timestamp
1042 (date and time) of an image is printed by image
1043 commands like bootm or iminfo. This option is
1044 automatically enabled when you select CONFIG_CMD_DATE .
1046 - Partition Labels (disklabels) Supported:
1047 Zero or more of the following:
1048 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1049 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1050 Intel architecture, USB sticks, etc.
1051 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1052 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1053 bootloader. Note 2TB partition limit; see
1055 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1057 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1058 CONFIG_CMD_SCSI) you must configure support for at
1059 least one non-MTD partition type as well.
1062 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1063 board configurations files but used nowhere!
1065 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1066 be performed by calling the function
1067 ide_set_reset(int reset)
1068 which has to be defined in a board specific file
1073 Set this to enable ATAPI support.
1078 Set this to enable support for disks larger than 137GB
1079 Also look at CONFIG_SYS_64BIT_LBA.
1080 Whithout these , LBA48 support uses 32bit variables and will 'only'
1081 support disks up to 2.1TB.
1083 CONFIG_SYS_64BIT_LBA:
1084 When enabled, makes the IDE subsystem use 64bit sector addresses.
1088 At the moment only there is only support for the
1089 SYM53C8XX SCSI controller; define
1090 CONFIG_SCSI_SYM53C8XX to enable it.
1092 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1093 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1094 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1095 maximum numbers of LUNs, SCSI ID's and target
1097 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1099 The environment variable 'scsidevs' is set to the number of
1100 SCSI devices found during the last scan.
1102 - NETWORK Support (PCI):
1104 Support for Intel 8254x/8257x gigabit chips.
1107 Utility code for direct access to the SPI bus on Intel 8257x.
1108 This does not do anything useful unless you set at least one
1109 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1111 CONFIG_E1000_SPI_GENERIC
1112 Allow generic access to the SPI bus on the Intel 8257x, for
1113 example with the "sspi" command.
1116 Management command for E1000 devices. When used on devices
1117 with SPI support you can reprogram the EEPROM from U-Boot.
1119 CONFIG_E1000_FALLBACK_MAC
1120 default MAC for empty EEPROM after production.
1123 Support for Intel 82557/82559/82559ER chips.
1124 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1125 write routine for first time initialisation.
1128 Support for Digital 2114x chips.
1129 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1130 modem chip initialisation (KS8761/QS6611).
1133 Support for National dp83815 chips.
1136 Support for National dp8382[01] gigabit chips.
1138 - NETWORK Support (other):
1140 CONFIG_DRIVER_AT91EMAC
1141 Support for AT91RM9200 EMAC.
1144 Define this to use reduced MII inteface
1146 CONFIG_DRIVER_AT91EMAC_QUIET
1147 If this defined, the driver is quiet.
1148 The driver doen't show link status messages.
1150 CONFIG_CALXEDA_XGMAC
1151 Support for the Calxeda XGMAC device
1154 Support for SMSC's LAN91C96 chips.
1156 CONFIG_LAN91C96_BASE
1157 Define this to hold the physical address
1158 of the LAN91C96's I/O space
1160 CONFIG_LAN91C96_USE_32_BIT
1161 Define this to enable 32 bit addressing
1164 Support for SMSC's LAN91C111 chip
1166 CONFIG_SMC91111_BASE
1167 Define this to hold the physical address
1168 of the device (I/O space)
1170 CONFIG_SMC_USE_32_BIT
1171 Define this if data bus is 32 bits
1173 CONFIG_SMC_USE_IOFUNCS
1174 Define this to use i/o functions instead of macros
1175 (some hardware wont work with macros)
1177 CONFIG_DRIVER_TI_EMAC
1178 Support for davinci emac
1180 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1181 Define this if you have more then 3 PHYs.
1184 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1186 CONFIG_FTGMAC100_EGIGA
1187 Define this to use GE link update with gigabit PHY.
1188 Define this if FTGMAC100 is connected to gigabit PHY.
1189 If your system has 10/100 PHY only, it might not occur
1190 wrong behavior. Because PHY usually return timeout or
1191 useless data when polling gigabit status and gigabit
1192 control registers. This behavior won't affect the
1193 correctnessof 10/100 link speed update.
1196 Support for SMSC's LAN911x and LAN921x chips
1199 Define this to hold the physical address
1200 of the device (I/O space)
1202 CONFIG_SMC911X_32_BIT
1203 Define this if data bus is 32 bits
1205 CONFIG_SMC911X_16_BIT
1206 Define this if data bus is 16 bits. If your processor
1207 automatically converts one 32 bit word to two 16 bit
1208 words you may also try CONFIG_SMC911X_32_BIT.
1211 Support for Renesas on-chip Ethernet controller
1213 CONFIG_SH_ETHER_USE_PORT
1214 Define the number of ports to be used
1216 CONFIG_SH_ETHER_PHY_ADDR
1217 Define the ETH PHY's address
1219 CONFIG_SH_ETHER_CACHE_WRITEBACK
1220 If this option is set, the driver enables cache flush.
1224 Support TPM devices.
1227 Support for i2c bus TPM devices. Only one device
1228 per system is supported at this time.
1230 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1231 Define the the i2c bus number for the TPM device
1233 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1234 Define the TPM's address on the i2c bus
1236 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1237 Define the burst count bytes upper limit
1239 CONFIG_TPM_ATMEL_TWI
1240 Support for Atmel TWI TPM device. Requires I2C support.
1243 Support for generic parallel port TPM devices. Only one device
1244 per system is supported at this time.
1246 CONFIG_TPM_TIS_BASE_ADDRESS
1247 Base address where the generic TPM device is mapped
1248 to. Contemporary x86 systems usually map it at
1252 Add tpm monitor functions.
1253 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1254 provides monitor access to authorized functions.
1257 Define this to enable the TPM support library which provides
1258 functional interfaces to some TPM commands.
1259 Requires support for a TPM device.
1261 CONFIG_TPM_AUTH_SESSIONS
1262 Define this to enable authorized functions in the TPM library.
1263 Requires CONFIG_TPM and CONFIG_SHA1.
1266 At the moment only the UHCI host controller is
1267 supported (PIP405, MIP405, MPC5200); define
1268 CONFIG_USB_UHCI to enable it.
1269 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1270 and define CONFIG_USB_STORAGE to enable the USB
1273 Supported are USB Keyboards and USB Floppy drives
1275 MPC5200 USB requires additional defines:
1277 for 528 MHz Clock: 0x0001bbbb
1281 for differential drivers: 0x00001000
1282 for single ended drivers: 0x00005000
1283 for differential drivers on PSC3: 0x00000100
1284 for single ended drivers on PSC3: 0x00004100
1285 CONFIG_SYS_USB_EVENT_POLL
1286 May be defined to allow interrupt polling
1287 instead of using asynchronous interrupts
1289 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1290 txfilltuning field in the EHCI controller on reset.
1292 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1293 interval for usb hub power-on delay.(minimum 100msec)
1296 Define the below if you wish to use the USB console.
1297 Once firmware is rebuilt from a serial console issue the
1298 command "setenv stdin usbtty; setenv stdout usbtty" and
1299 attach your USB cable. The Unix command "dmesg" should print
1300 it has found a new device. The environment variable usbtty
1301 can be set to gserial or cdc_acm to enable your device to
1302 appear to a USB host as a Linux gserial device or a
1303 Common Device Class Abstract Control Model serial device.
1304 If you select usbtty = gserial you should be able to enumerate
1306 # modprobe usbserial vendor=0xVendorID product=0xProductID
1307 else if using cdc_acm, simply setting the environment
1308 variable usbtty to be cdc_acm should suffice. The following
1309 might be defined in YourBoardName.h
1312 Define this to build a UDC device
1315 Define this to have a tty type of device available to
1316 talk to the UDC device
1319 Define this to enable the high speed support for usb
1320 device and usbtty. If this feature is enabled, a routine
1321 int is_usbd_high_speed(void)
1322 also needs to be defined by the driver to dynamically poll
1323 whether the enumeration has succeded at high speed or full
1326 CONFIG_SYS_CONSOLE_IS_IN_ENV
1327 Define this if you want stdin, stdout &/or stderr to
1331 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1332 Derive USB clock from external clock "blah"
1333 - CONFIG_SYS_USB_EXTC_CLK 0x02
1335 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1336 Derive USB clock from brgclk
1337 - CONFIG_SYS_USB_BRG_CLK 0x04
1339 If you have a USB-IF assigned VendorID then you may wish to
1340 define your own vendor specific values either in BoardName.h
1341 or directly in usbd_vendor_info.h. If you don't define
1342 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1343 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1344 should pretend to be a Linux device to it's target host.
1346 CONFIG_USBD_MANUFACTURER
1347 Define this string as the name of your company for
1348 - CONFIG_USBD_MANUFACTURER "my company"
1350 CONFIG_USBD_PRODUCT_NAME
1351 Define this string as the name of your product
1352 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1354 CONFIG_USBD_VENDORID
1355 Define this as your assigned Vendor ID from the USB
1356 Implementors Forum. This *must* be a genuine Vendor ID
1357 to avoid polluting the USB namespace.
1358 - CONFIG_USBD_VENDORID 0xFFFF
1360 CONFIG_USBD_PRODUCTID
1361 Define this as the unique Product ID
1363 - CONFIG_USBD_PRODUCTID 0xFFFF
1365 - ULPI Layer Support:
1366 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1367 the generic ULPI layer. The generic layer accesses the ULPI PHY
1368 via the platform viewport, so you need both the genric layer and
1369 the viewport enabled. Currently only Chipidea/ARC based
1370 viewport is supported.
1371 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1372 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1373 If your ULPI phy needs a different reference clock than the
1374 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1375 the appropriate value in Hz.
1378 The MMC controller on the Intel PXA is supported. To
1379 enable this define CONFIG_MMC. The MMC can be
1380 accessed from the boot prompt by mapping the device
1381 to physical memory similar to flash. Command line is
1382 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1383 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1386 Support for Renesas on-chip MMCIF controller
1388 CONFIG_SH_MMCIF_ADDR
1389 Define the base address of MMCIF registers
1392 Define the clock frequency for MMCIF
1394 - USB Device Firmware Update (DFU) class support:
1396 This enables the USB portion of the DFU USB class
1399 This enables the command "dfu" which is used to have
1400 U-Boot create a DFU class device via USB. This command
1401 requires that the "dfu_alt_info" environment variable be
1402 set and define the alt settings to expose to the host.
1405 This enables support for exposing (e)MMC devices via DFU.
1408 This enables support for exposing NAND devices via DFU.
1411 This enables support for exposing RAM via DFU.
1412 Note: DFU spec refer to non-volatile memory usage, but
1413 allow usages beyond the scope of spec - here RAM usage,
1414 one that would help mostly the developer.
1416 CONFIG_SYS_DFU_DATA_BUF_SIZE
1417 Dfu transfer uses a buffer before writing data to the
1418 raw storage device. Make the size (in bytes) of this buffer
1419 configurable. The size of this buffer is also configurable
1420 through the "dfu_bufsiz" environment variable.
1422 CONFIG_SYS_DFU_MAX_FILE_SIZE
1423 When updating files rather than the raw storage device,
1424 we use a static buffer to copy the file into and then write
1425 the buffer once we've been given the whole file. Define
1426 this to the maximum filesize (in bytes) for the buffer.
1427 Default is 4 MiB if undefined.
1429 - Journaling Flash filesystem support:
1430 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1431 CONFIG_JFFS2_NAND_DEV
1432 Define these for a default partition on a NAND device
1434 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1435 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1436 Define these for a default partition on a NOR device
1438 CONFIG_SYS_JFFS_CUSTOM_PART
1439 Define this to create an own partition. You have to provide a
1440 function struct part_info* jffs2_part_info(int part_num)
1442 If you define only one JFFS2 partition you may also want to
1443 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1444 to disable the command chpart. This is the default when you
1445 have not defined a custom partition
1447 - FAT(File Allocation Table) filesystem write function support:
1450 Define this to enable support for saving memory data as a
1451 file in FAT formatted partition.
1453 This will also enable the command "fatwrite" enabling the
1454 user to write files to FAT.
1456 CBFS (Coreboot Filesystem) support
1459 Define this to enable support for reading from a Coreboot
1460 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1466 Define this to enable standard (PC-Style) keyboard
1470 Standard PC keyboard driver with US (is default) and
1471 GERMAN key layout (switch via environment 'keymap=de') support.
1472 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1473 for cfb_console. Supports cursor blinking.
1476 Enables a Chrome OS keyboard using the CROS_EC interface.
1477 This uses CROS_EC to communicate with a second microcontroller
1478 which provides key scans on request.
1483 Define this to enable video support (for output to
1486 CONFIG_VIDEO_CT69000
1488 Enable Chips & Technologies 69000 Video chip
1490 CONFIG_VIDEO_SMI_LYNXEM
1491 Enable Silicon Motion SMI 712/710/810 Video chip. The
1492 video output is selected via environment 'videoout'
1493 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1496 For the CT69000 and SMI_LYNXEM drivers, videomode is
1497 selected via environment 'videomode'. Two different ways
1499 - "videomode=num" 'num' is a standard LiLo mode numbers.
1500 Following standard modes are supported (* is default):
1502 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1503 -------------+---------------------------------------------
1504 8 bits | 0x301* 0x303 0x305 0x161 0x307
1505 15 bits | 0x310 0x313 0x316 0x162 0x319
1506 16 bits | 0x311 0x314 0x317 0x163 0x31A
1507 24 bits | 0x312 0x315 0x318 ? 0x31B
1508 -------------+---------------------------------------------
1509 (i.e. setenv videomode 317; saveenv; reset;)
1511 - "videomode=bootargs" all the video parameters are parsed
1512 from the bootargs. (See drivers/video/videomodes.c)
1515 CONFIG_VIDEO_SED13806
1516 Enable Epson SED13806 driver. This driver supports 8bpp
1517 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1518 or CONFIG_VIDEO_SED13806_16BPP
1521 Enable the Freescale DIU video driver. Reference boards for
1522 SOCs that have a DIU should define this macro to enable DIU
1523 support, and should also define these other macros:
1529 CONFIG_VIDEO_SW_CURSOR
1530 CONFIG_VGA_AS_SINGLE_DEVICE
1532 CONFIG_VIDEO_BMP_LOGO
1534 The DIU driver will look for the 'video-mode' environment
1535 variable, and if defined, enable the DIU as a console during
1536 boot. See the documentation file README.video for a
1537 description of this variable.
1541 Enable the VGA video / BIOS for x86. The alternative if you
1542 are using coreboot is to use the coreboot frame buffer
1549 Define this to enable a custom keyboard support.
1550 This simply calls drv_keyboard_init() which must be
1551 defined in your board-specific files.
1552 The only board using this so far is RBC823.
1554 - LCD Support: CONFIG_LCD
1556 Define this to enable LCD support (for output to LCD
1557 display); also select one of the supported displays
1558 by defining one of these:
1562 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1564 CONFIG_NEC_NL6448AC33:
1566 NEC NL6448AC33-18. Active, color, single scan.
1568 CONFIG_NEC_NL6448BC20
1570 NEC NL6448BC20-08. 6.5", 640x480.
1571 Active, color, single scan.
1573 CONFIG_NEC_NL6448BC33_54
1575 NEC NL6448BC33-54. 10.4", 640x480.
1576 Active, color, single scan.
1580 Sharp 320x240. Active, color, single scan.
1581 It isn't 16x9, and I am not sure what it is.
1583 CONFIG_SHARP_LQ64D341
1585 Sharp LQ64D341 display, 640x480.
1586 Active, color, single scan.
1590 HLD1045 display, 640x480.
1591 Active, color, single scan.
1595 Optrex CBL50840-2 NF-FW 99 22 M5
1597 Hitachi LMG6912RPFC-00T
1601 320x240. Black & white.
1603 Normally display is black on white background; define
1604 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1606 CONFIG_LCD_ALIGNMENT
1608 Normally the LCD is page-aligned (tyically 4KB). If this is
1609 defined then the LCD will be aligned to this value instead.
1610 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1611 here, since it is cheaper to change data cache settings on
1612 a per-section basis.
1614 CONFIG_CONSOLE_SCROLL_LINES
1616 When the console need to be scrolled, this is the number of
1617 lines to scroll by. It defaults to 1. Increasing this makes
1618 the console jump but can help speed up operation when scrolling
1623 Support drawing of RLE8-compressed bitmaps on the LCD.
1627 Enables an 'i2c edid' command which can read EDID
1628 information over I2C from an attached LCD display.
1630 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1632 If this option is set, the environment is checked for
1633 a variable "splashimage". If found, the usual display
1634 of logo, copyright and system information on the LCD
1635 is suppressed and the BMP image at the address
1636 specified in "splashimage" is loaded instead. The
1637 console is redirected to the "nulldev", too. This
1638 allows for a "silent" boot where a splash screen is
1639 loaded very quickly after power-on.
1641 CONFIG_SPLASHIMAGE_GUARD
1643 If this option is set, then U-Boot will prevent the environment
1644 variable "splashimage" from being set to a problematic address
1645 (see README.displaying-bmps and README.arm-unaligned-accesses).
1646 This option is useful for targets where, due to alignment
1647 restrictions, an improperly aligned BMP image will cause a data
1648 abort. If you think you will not have problems with unaligned
1649 accesses (for example because your toolchain prevents them)
1650 there is no need to set this option.
1652 CONFIG_SPLASH_SCREEN_ALIGN
1654 If this option is set the splash image can be freely positioned
1655 on the screen. Environment variable "splashpos" specifies the
1656 position as "x,y". If a positive number is given it is used as
1657 number of pixel from left/top. If a negative number is given it
1658 is used as number of pixel from right/bottom. You can also
1659 specify 'm' for centering the image.
1662 setenv splashpos m,m
1663 => image at center of screen
1665 setenv splashpos 30,20
1666 => image at x = 30 and y = 20
1668 setenv splashpos -10,m
1669 => vertically centered image
1670 at x = dspWidth - bmpWidth - 9
1672 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1674 If this option is set, additionally to standard BMP
1675 images, gzipped BMP images can be displayed via the
1676 splashscreen support or the bmp command.
1678 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1680 If this option is set, 8-bit RLE compressed BMP images
1681 can be displayed via the splashscreen support or the
1684 - Do compresssing for memory range:
1687 If this option is set, it would use zlib deflate method
1688 to compress the specified memory at its best effort.
1690 - Compression support:
1693 Enabled by default to support gzip compressed images.
1697 If this option is set, support for bzip2 compressed
1698 images is included. If not, only uncompressed and gzip
1699 compressed images are supported.
1701 NOTE: the bzip2 algorithm requires a lot of RAM, so
1702 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1707 If this option is set, support for lzma compressed
1710 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1711 requires an amount of dynamic memory that is given by the
1714 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1716 Where lc and lp stand for, respectively, Literal context bits
1717 and Literal pos bits.
1719 This value is upper-bounded by 14MB in the worst case. Anyway,
1720 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1721 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1722 a very small buffer.
1724 Use the lzmainfo tool to determinate the lc and lp values and
1725 then calculate the amount of needed dynamic memory (ensuring
1726 the appropriate CONFIG_SYS_MALLOC_LEN value).
1730 If this option is set, support for LZO compressed images
1736 The address of PHY on MII bus.
1738 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1740 The clock frequency of the MII bus
1744 If this option is set, support for speed/duplex
1745 detection of gigabit PHY is included.
1747 CONFIG_PHY_RESET_DELAY
1749 Some PHY like Intel LXT971A need extra delay after
1750 reset before any MII register access is possible.
1751 For such PHY, set this option to the usec delay
1752 required. (minimum 300usec for LXT971A)
1754 CONFIG_PHY_CMD_DELAY (ppc4xx)
1756 Some PHY like Intel LXT971A need extra delay after
1757 command issued before MII status register can be read
1767 Define a default value for Ethernet address to use
1768 for the respective Ethernet interface, in case this
1769 is not determined automatically.
1774 Define a default value for the IP address to use for
1775 the default Ethernet interface, in case this is not
1776 determined through e.g. bootp.
1777 (Environment variable "ipaddr")
1779 - Server IP address:
1782 Defines a default value for the IP address of a TFTP
1783 server to contact when using the "tftboot" command.
1784 (Environment variable "serverip")
1786 CONFIG_KEEP_SERVERADDR
1788 Keeps the server's MAC address, in the env 'serveraddr'
1789 for passing to bootargs (like Linux's netconsole option)
1791 - Gateway IP address:
1794 Defines a default value for the IP address of the
1795 default router where packets to other networks are
1797 (Environment variable "gatewayip")
1802 Defines a default value for the subnet mask (or
1803 routing prefix) which is used to determine if an IP
1804 address belongs to the local subnet or needs to be
1805 forwarded through a router.
1806 (Environment variable "netmask")
1808 - Multicast TFTP Mode:
1811 Defines whether you want to support multicast TFTP as per
1812 rfc-2090; for example to work with atftp. Lets lots of targets
1813 tftp down the same boot image concurrently. Note: the Ethernet
1814 driver in use must provide a function: mcast() to join/leave a
1817 - BOOTP Recovery Mode:
1818 CONFIG_BOOTP_RANDOM_DELAY
1820 If you have many targets in a network that try to
1821 boot using BOOTP, you may want to avoid that all
1822 systems send out BOOTP requests at precisely the same
1823 moment (which would happen for instance at recovery
1824 from a power failure, when all systems will try to
1825 boot, thus flooding the BOOTP server. Defining
1826 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1827 inserted before sending out BOOTP requests. The
1828 following delays are inserted then:
1830 1st BOOTP request: delay 0 ... 1 sec
1831 2nd BOOTP request: delay 0 ... 2 sec
1832 3rd BOOTP request: delay 0 ... 4 sec
1834 BOOTP requests: delay 0 ... 8 sec
1836 - DHCP Advanced Options:
1837 You can fine tune the DHCP functionality by defining
1838 CONFIG_BOOTP_* symbols:
1840 CONFIG_BOOTP_SUBNETMASK
1841 CONFIG_BOOTP_GATEWAY
1842 CONFIG_BOOTP_HOSTNAME
1843 CONFIG_BOOTP_NISDOMAIN
1844 CONFIG_BOOTP_BOOTPATH
1845 CONFIG_BOOTP_BOOTFILESIZE
1848 CONFIG_BOOTP_SEND_HOSTNAME
1849 CONFIG_BOOTP_NTPSERVER
1850 CONFIG_BOOTP_TIMEOFFSET
1851 CONFIG_BOOTP_VENDOREX
1852 CONFIG_BOOTP_MAY_FAIL
1854 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1855 environment variable, not the BOOTP server.
1857 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1858 after the configured retry count, the call will fail
1859 instead of starting over. This can be used to fail over
1860 to Link-local IP address configuration if the DHCP server
1863 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1864 serverip from a DHCP server, it is possible that more
1865 than one DNS serverip is offered to the client.
1866 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1867 serverip will be stored in the additional environment
1868 variable "dnsip2". The first DNS serverip is always
1869 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1872 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1873 to do a dynamic update of a DNS server. To do this, they
1874 need the hostname of the DHCP requester.
1875 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1876 of the "hostname" environment variable is passed as
1877 option 12 to the DHCP server.
1879 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1881 A 32bit value in microseconds for a delay between
1882 receiving a "DHCP Offer" and sending the "DHCP Request".
1883 This fixes a problem with certain DHCP servers that don't
1884 respond 100% of the time to a "DHCP request". E.g. On an
1885 AT91RM9200 processor running at 180MHz, this delay needed
1886 to be *at least* 15,000 usec before a Windows Server 2003
1887 DHCP server would reply 100% of the time. I recommend at
1888 least 50,000 usec to be safe. The alternative is to hope
1889 that one of the retries will be successful but note that
1890 the DHCP timeout and retry process takes a longer than
1893 - Link-local IP address negotiation:
1894 Negotiate with other link-local clients on the local network
1895 for an address that doesn't require explicit configuration.
1896 This is especially useful if a DHCP server cannot be guaranteed
1897 to exist in all environments that the device must operate.
1899 See doc/README.link-local for more information.
1902 CONFIG_CDP_DEVICE_ID
1904 The device id used in CDP trigger frames.
1906 CONFIG_CDP_DEVICE_ID_PREFIX
1908 A two character string which is prefixed to the MAC address
1913 A printf format string which contains the ascii name of
1914 the port. Normally is set to "eth%d" which sets
1915 eth0 for the first Ethernet, eth1 for the second etc.
1917 CONFIG_CDP_CAPABILITIES
1919 A 32bit integer which indicates the device capabilities;
1920 0x00000010 for a normal host which does not forwards.
1924 An ascii string containing the version of the software.
1928 An ascii string containing the name of the platform.
1932 A 32bit integer sent on the trigger.
1934 CONFIG_CDP_POWER_CONSUMPTION
1936 A 16bit integer containing the power consumption of the
1937 device in .1 of milliwatts.
1939 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1941 A byte containing the id of the VLAN.
1943 - Status LED: CONFIG_STATUS_LED
1945 Several configurations allow to display the current
1946 status using a LED. For instance, the LED will blink
1947 fast while running U-Boot code, stop blinking as
1948 soon as a reply to a BOOTP request was received, and
1949 start blinking slow once the Linux kernel is running
1950 (supported by a status LED driver in the Linux
1951 kernel). Defining CONFIG_STATUS_LED enables this
1954 - CAN Support: CONFIG_CAN_DRIVER
1956 Defining CONFIG_CAN_DRIVER enables CAN driver support
1957 on those systems that support this (optional)
1958 feature, like the TQM8xxL modules.
1960 - I2C Support: CONFIG_SYS_I2C
1962 This enable the NEW i2c subsystem, and will allow you to use
1963 i2c commands at the u-boot command line (as long as you set
1964 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1965 based realtime clock chips or other i2c devices. See
1966 common/cmd_i2c.c for a description of the command line
1969 ported i2c driver to the new framework:
1970 - drivers/i2c/soft_i2c.c:
1971 - activate first bus with CONFIG_SYS_I2C_SOFT define
1972 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1973 for defining speed and slave address
1974 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1975 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1976 for defining speed and slave address
1977 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1978 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1979 for defining speed and slave address
1980 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1981 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1982 for defining speed and slave address
1984 - drivers/i2c/fsl_i2c.c:
1985 - activate i2c driver with CONFIG_SYS_I2C_FSL
1986 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1987 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1988 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1990 - If your board supports a second fsl i2c bus, define
1991 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1992 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1993 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1996 - drivers/i2c/tegra_i2c.c:
1997 - activate this driver with CONFIG_SYS_I2C_TEGRA
1998 - This driver adds 4 i2c buses with a fix speed from
1999 100000 and the slave addr 0!
2001 - drivers/i2c/ppc4xx_i2c.c
2002 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2003 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2004 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2006 - drivers/i2c/i2c_mxc.c
2007 - activate this driver with CONFIG_SYS_I2C_MXC
2008 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2009 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2010 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2011 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2012 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2013 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2014 If thoses defines are not set, default value is 100000
2015 for speed, and 0 for slave.
2017 - drivers/i2c/rcar_i2c.c:
2018 - activate this driver with CONFIG_SYS_I2C_RCAR
2019 - This driver adds 4 i2c buses
2021 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2022 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2023 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2024 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2025 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2026 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2027 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2028 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2029 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2033 CONFIG_SYS_NUM_I2C_BUSES
2034 Hold the number of i2c busses you want to use. If you
2035 don't use/have i2c muxes on your i2c bus, this
2036 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2039 CONFIG_SYS_I2C_DIRECT_BUS
2040 define this, if you don't use i2c muxes on your hardware.
2041 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2044 CONFIG_SYS_I2C_MAX_HOPS
2045 define how many muxes are maximal consecutively connected
2046 on one i2c bus. If you not use i2c muxes, omit this
2049 CONFIG_SYS_I2C_BUSES
2050 hold a list of busses you want to use, only used if
2051 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2052 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2053 CONFIG_SYS_NUM_I2C_BUSES = 9:
2055 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2056 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2057 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2058 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2059 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2060 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2061 {1, {I2C_NULL_HOP}}, \
2062 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2063 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2067 bus 0 on adapter 0 without a mux
2068 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2069 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2070 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2071 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2072 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2073 bus 6 on adapter 1 without a mux
2074 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2075 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2077 If you do not have i2c muxes on your board, omit this define.
2079 - Legacy I2C Support: CONFIG_HARD_I2C
2081 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2082 provides the following compelling advantages:
2084 - more than one i2c adapter is usable
2085 - approved multibus support
2086 - better i2c mux support
2088 ** Please consider updating your I2C driver now. **
2090 These enable legacy I2C serial bus commands. Defining
2091 CONFIG_HARD_I2C will include the appropriate I2C driver
2092 for the selected CPU.
2094 This will allow you to use i2c commands at the u-boot
2095 command line (as long as you set CONFIG_CMD_I2C in
2096 CONFIG_COMMANDS) and communicate with i2c based realtime
2097 clock chips. See common/cmd_i2c.c for a description of the
2098 command line interface.
2100 CONFIG_HARD_I2C selects a hardware I2C controller.
2102 There are several other quantities that must also be
2103 defined when you define CONFIG_HARD_I2C.
2105 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2106 to be the frequency (in Hz) at which you wish your i2c bus
2107 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2108 the CPU's i2c node address).
2110 Now, the u-boot i2c code for the mpc8xx
2111 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2112 and so its address should therefore be cleared to 0 (See,
2113 eg, MPC823e User's Manual p.16-473). So, set
2114 CONFIG_SYS_I2C_SLAVE to 0.
2116 CONFIG_SYS_I2C_INIT_MPC5XXX
2118 When a board is reset during an i2c bus transfer
2119 chips might think that the current transfer is still
2120 in progress. Reset the slave devices by sending start
2121 commands until the slave device responds.
2123 That's all that's required for CONFIG_HARD_I2C.
2125 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2126 then the following macros need to be defined (examples are
2127 from include/configs/lwmon.h):
2131 (Optional). Any commands necessary to enable the I2C
2132 controller or configure ports.
2134 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2138 (Only for MPC8260 CPU). The I/O port to use (the code
2139 assumes both bits are on the same port). Valid values
2140 are 0..3 for ports A..D.
2144 The code necessary to make the I2C data line active
2145 (driven). If the data line is open collector, this
2148 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2152 The code necessary to make the I2C data line tri-stated
2153 (inactive). If the data line is open collector, this
2156 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2160 Code that returns true if the I2C data line is high,
2163 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2167 If <bit> is true, sets the I2C data line high. If it
2168 is false, it clears it (low).
2170 eg: #define I2C_SDA(bit) \
2171 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2172 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2176 If <bit> is true, sets the I2C clock line high. If it
2177 is false, it clears it (low).
2179 eg: #define I2C_SCL(bit) \
2180 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2181 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2185 This delay is invoked four times per clock cycle so this
2186 controls the rate of data transfer. The data rate thus
2187 is 1 / (I2C_DELAY * 4). Often defined to be something
2190 #define I2C_DELAY udelay(2)
2192 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2194 If your arch supports the generic GPIO framework (asm/gpio.h),
2195 then you may alternatively define the two GPIOs that are to be
2196 used as SCL / SDA. Any of the previous I2C_xxx macros will
2197 have GPIO-based defaults assigned to them as appropriate.
2199 You should define these to the GPIO value as given directly to
2200 the generic GPIO functions.
2202 CONFIG_SYS_I2C_INIT_BOARD
2204 When a board is reset during an i2c bus transfer
2205 chips might think that the current transfer is still
2206 in progress. On some boards it is possible to access
2207 the i2c SCLK line directly, either by using the
2208 processor pin as a GPIO or by having a second pin
2209 connected to the bus. If this option is defined a
2210 custom i2c_init_board() routine in boards/xxx/board.c
2211 is run early in the boot sequence.
2213 CONFIG_SYS_I2C_BOARD_LATE_INIT
2215 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2216 defined a custom i2c_board_late_init() routine in
2217 boards/xxx/board.c is run AFTER the operations in i2c_init()
2218 is completed. This callpoint can be used to unreset i2c bus
2219 using CPU i2c controller register accesses for CPUs whose i2c
2220 controller provide such a method. It is called at the end of
2221 i2c_init() to allow i2c_init operations to setup the i2c bus
2222 controller on the CPU (e.g. setting bus speed & slave address).
2224 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2226 This option enables configuration of bi_iic_fast[] flags
2227 in u-boot bd_info structure based on u-boot environment
2228 variable "i2cfast". (see also i2cfast)
2230 CONFIG_I2C_MULTI_BUS
2232 This option allows the use of multiple I2C buses, each of which
2233 must have a controller. At any point in time, only one bus is
2234 active. To switch to a different bus, use the 'i2c dev' command.
2235 Note that bus numbering is zero-based.
2237 CONFIG_SYS_I2C_NOPROBES
2239 This option specifies a list of I2C devices that will be skipped
2240 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2241 is set, specify a list of bus-device pairs. Otherwise, specify
2242 a 1D array of device addresses
2245 #undef CONFIG_I2C_MULTI_BUS
2246 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2248 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2250 #define CONFIG_I2C_MULTI_BUS
2251 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2253 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2255 CONFIG_SYS_SPD_BUS_NUM
2257 If defined, then this indicates the I2C bus number for DDR SPD.
2258 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2260 CONFIG_SYS_RTC_BUS_NUM
2262 If defined, then this indicates the I2C bus number for the RTC.
2263 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2265 CONFIG_SYS_DTT_BUS_NUM
2267 If defined, then this indicates the I2C bus number for the DTT.
2268 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2270 CONFIG_SYS_I2C_DTT_ADDR:
2272 If defined, specifies the I2C address of the DTT device.
2273 If not defined, then U-Boot uses predefined value for
2274 specified DTT device.
2276 CONFIG_SOFT_I2C_READ_REPEATED_START
2278 defining this will force the i2c_read() function in
2279 the soft_i2c driver to perform an I2C repeated start
2280 between writing the address pointer and reading the
2281 data. If this define is omitted the default behaviour
2282 of doing a stop-start sequence will be used. Most I2C
2283 devices can use either method, but some require one or
2286 - SPI Support: CONFIG_SPI
2288 Enables SPI driver (so far only tested with
2289 SPI EEPROM, also an instance works with Crystal A/D and
2290 D/As on the SACSng board)
2294 Enables the driver for SPI controller on SuperH. Currently
2295 only SH7757 is supported.
2299 Enables extended (16-bit) SPI EEPROM addressing.
2300 (symmetrical to CONFIG_I2C_X)
2304 Enables a software (bit-bang) SPI driver rather than
2305 using hardware support. This is a general purpose
2306 driver that only requires three general I/O port pins
2307 (two outputs, one input) to function. If this is
2308 defined, the board configuration must define several
2309 SPI configuration items (port pins to use, etc). For
2310 an example, see include/configs/sacsng.h.
2314 Enables a hardware SPI driver for general-purpose reads
2315 and writes. As with CONFIG_SOFT_SPI, the board configuration
2316 must define a list of chip-select function pointers.
2317 Currently supported on some MPC8xxx processors. For an
2318 example, see include/configs/mpc8349emds.h.
2322 Enables the driver for the SPI controllers on i.MX and MXC
2323 SoCs. Currently i.MX31/35/51 are supported.
2325 - FPGA Support: CONFIG_FPGA
2327 Enables FPGA subsystem.
2329 CONFIG_FPGA_<vendor>
2331 Enables support for specific chip vendors.
2334 CONFIG_FPGA_<family>
2336 Enables support for FPGA family.
2337 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2341 Specify the number of FPGA devices to support.
2343 CONFIG_SYS_FPGA_PROG_FEEDBACK
2345 Enable printing of hash marks during FPGA configuration.
2347 CONFIG_SYS_FPGA_CHECK_BUSY
2349 Enable checks on FPGA configuration interface busy
2350 status by the configuration function. This option
2351 will require a board or device specific function to
2356 If defined, a function that provides delays in the FPGA
2357 configuration driver.
2359 CONFIG_SYS_FPGA_CHECK_CTRLC
2360 Allow Control-C to interrupt FPGA configuration
2362 CONFIG_SYS_FPGA_CHECK_ERROR
2364 Check for configuration errors during FPGA bitfile
2365 loading. For example, abort during Virtex II
2366 configuration if the INIT_B line goes low (which
2367 indicated a CRC error).
2369 CONFIG_SYS_FPGA_WAIT_INIT
2371 Maximum time to wait for the INIT_B line to deassert
2372 after PROB_B has been deasserted during a Virtex II
2373 FPGA configuration sequence. The default time is 500
2376 CONFIG_SYS_FPGA_WAIT_BUSY
2378 Maximum time to wait for BUSY to deassert during
2379 Virtex II FPGA configuration. The default is 5 ms.
2381 CONFIG_SYS_FPGA_WAIT_CONFIG
2383 Time to wait after FPGA configuration. The default is
2386 - Configuration Management:
2389 If defined, this string will be added to the U-Boot
2390 version information (U_BOOT_VERSION)
2392 - Vendor Parameter Protection:
2394 U-Boot considers the values of the environment
2395 variables "serial#" (Board Serial Number) and
2396 "ethaddr" (Ethernet Address) to be parameters that
2397 are set once by the board vendor / manufacturer, and
2398 protects these variables from casual modification by
2399 the user. Once set, these variables are read-only,
2400 and write or delete attempts are rejected. You can
2401 change this behaviour:
2403 If CONFIG_ENV_OVERWRITE is #defined in your config
2404 file, the write protection for vendor parameters is
2405 completely disabled. Anybody can change or delete
2408 Alternatively, if you #define _both_ CONFIG_ETHADDR
2409 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2410 Ethernet address is installed in the environment,
2411 which can be changed exactly ONCE by the user. [The
2412 serial# is unaffected by this, i. e. it remains
2415 The same can be accomplished in a more flexible way
2416 for any variable by configuring the type of access
2417 to allow for those variables in the ".flags" variable
2418 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2423 Define this variable to enable the reservation of
2424 "protected RAM", i. e. RAM which is not overwritten
2425 by U-Boot. Define CONFIG_PRAM to hold the number of
2426 kB you want to reserve for pRAM. You can overwrite
2427 this default value by defining an environment
2428 variable "pram" to the number of kB you want to
2429 reserve. Note that the board info structure will
2430 still show the full amount of RAM. If pRAM is
2431 reserved, a new environment variable "mem" will
2432 automatically be defined to hold the amount of
2433 remaining RAM in a form that can be passed as boot
2434 argument to Linux, for instance like that:
2436 setenv bootargs ... mem=\${mem}
2439 This way you can tell Linux not to use this memory,
2440 either, which results in a memory region that will
2441 not be affected by reboots.
2443 *WARNING* If your board configuration uses automatic
2444 detection of the RAM size, you must make sure that
2445 this memory test is non-destructive. So far, the
2446 following board configurations are known to be
2449 IVMS8, IVML24, SPD8xx, TQM8xxL,
2450 HERMES, IP860, RPXlite, LWMON,
2453 - Access to physical memory region (> 4GB)
2454 Some basic support is provided for operations on memory not
2455 normally accessible to U-Boot - e.g. some architectures
2456 support access to more than 4GB of memory on 32-bit
2457 machines using physical address extension or similar.
2458 Define CONFIG_PHYSMEM to access this basic support, which
2459 currently only supports clearing the memory.
2464 Define this variable to stop the system in case of a
2465 fatal error, so that you have to reset it manually.
2466 This is probably NOT a good idea for an embedded
2467 system where you want the system to reboot
2468 automatically as fast as possible, but it may be
2469 useful during development since you can try to debug
2470 the conditions that lead to the situation.
2472 CONFIG_NET_RETRY_COUNT
2474 This variable defines the number of retries for
2475 network operations like ARP, RARP, TFTP, or BOOTP
2476 before giving up the operation. If not defined, a
2477 default value of 5 is used.
2481 Timeout waiting for an ARP reply in milliseconds.
2485 Timeout in milliseconds used in NFS protocol.
2486 If you encounter "ERROR: Cannot umount" in nfs command,
2487 try longer timeout such as
2488 #define CONFIG_NFS_TIMEOUT 10000UL
2490 - Command Interpreter:
2491 CONFIG_AUTO_COMPLETE
2493 Enable auto completion of commands using TAB.
2495 Note that this feature has NOT been implemented yet
2496 for the "hush" shell.
2499 CONFIG_SYS_HUSH_PARSER
2501 Define this variable to enable the "hush" shell (from
2502 Busybox) as command line interpreter, thus enabling
2503 powerful command line syntax like
2504 if...then...else...fi conditionals or `&&' and '||'
2505 constructs ("shell scripts").
2507 If undefined, you get the old, much simpler behaviour
2508 with a somewhat smaller memory footprint.
2511 CONFIG_SYS_PROMPT_HUSH_PS2
2513 This defines the secondary prompt string, which is
2514 printed when the command interpreter needs more input
2515 to complete a command. Usually "> ".
2519 In the current implementation, the local variables
2520 space and global environment variables space are
2521 separated. Local variables are those you define by
2522 simply typing `name=value'. To access a local
2523 variable later on, you have write `$name' or
2524 `${name}'; to execute the contents of a variable
2525 directly type `$name' at the command prompt.
2527 Global environment variables are those you use
2528 setenv/printenv to work with. To run a command stored
2529 in such a variable, you need to use the run command,
2530 and you must not use the '$' sign to access them.
2532 To store commands and special characters in a
2533 variable, please use double quotation marks
2534 surrounding the whole text of the variable, instead
2535 of the backslashes before semicolons and special
2538 - Commandline Editing and History:
2539 CONFIG_CMDLINE_EDITING
2541 Enable editing and History functions for interactive
2542 commandline input operations
2544 - Default Environment:
2545 CONFIG_EXTRA_ENV_SETTINGS
2547 Define this to contain any number of null terminated
2548 strings (variable = value pairs) that will be part of
2549 the default environment compiled into the boot image.
2551 For example, place something like this in your
2552 board's config file:
2554 #define CONFIG_EXTRA_ENV_SETTINGS \
2558 Warning: This method is based on knowledge about the
2559 internal format how the environment is stored by the
2560 U-Boot code. This is NOT an official, exported
2561 interface! Although it is unlikely that this format
2562 will change soon, there is no guarantee either.
2563 You better know what you are doing here.
2565 Note: overly (ab)use of the default environment is
2566 discouraged. Make sure to check other ways to preset
2567 the environment like the "source" command or the
2570 CONFIG_ENV_VARS_UBOOT_CONFIG
2572 Define this in order to add variables describing the
2573 U-Boot build configuration to the default environment.
2574 These will be named arch, cpu, board, vendor, and soc.
2576 Enabling this option will cause the following to be defined:
2584 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2586 Define this in order to add variables describing certain
2587 run-time determined information about the hardware to the
2588 environment. These will be named board_name, board_rev.
2590 CONFIG_DELAY_ENVIRONMENT
2592 Normally the environment is loaded when the board is
2593 intialised so that it is available to U-Boot. This inhibits
2594 that so that the environment is not available until
2595 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2596 this is instead controlled by the value of
2597 /config/load-environment.
2599 - DataFlash Support:
2600 CONFIG_HAS_DATAFLASH
2602 Defining this option enables DataFlash features and
2603 allows to read/write in Dataflash via the standard
2606 - Serial Flash support
2609 Defining this option enables SPI flash commands
2610 'sf probe/read/write/erase/update'.
2612 Usage requires an initial 'probe' to define the serial
2613 flash parameters, followed by read/write/erase/update
2616 The following defaults may be provided by the platform
2617 to handle the common case when only a single serial
2618 flash is present on the system.
2620 CONFIG_SF_DEFAULT_BUS Bus identifier
2621 CONFIG_SF_DEFAULT_CS Chip-select
2622 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2623 CONFIG_SF_DEFAULT_SPEED in Hz
2627 Define this option to include a destructive SPI flash
2630 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2632 Define this option to use the Bank addr/Extended addr
2633 support on SPI flashes which has size > 16Mbytes.
2635 - SystemACE Support:
2638 Adding this option adds support for Xilinx SystemACE
2639 chips attached via some sort of local bus. The address
2640 of the chip must also be defined in the
2641 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2643 #define CONFIG_SYSTEMACE
2644 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2646 When SystemACE support is added, the "ace" device type
2647 becomes available to the fat commands, i.e. fatls.
2649 - TFTP Fixed UDP Port:
2652 If this is defined, the environment variable tftpsrcp
2653 is used to supply the TFTP UDP source port value.
2654 If tftpsrcp isn't defined, the normal pseudo-random port
2655 number generator is used.
2657 Also, the environment variable tftpdstp is used to supply
2658 the TFTP UDP destination port value. If tftpdstp isn't
2659 defined, the normal port 69 is used.
2661 The purpose for tftpsrcp is to allow a TFTP server to
2662 blindly start the TFTP transfer using the pre-configured
2663 target IP address and UDP port. This has the effect of
2664 "punching through" the (Windows XP) firewall, allowing
2665 the remainder of the TFTP transfer to proceed normally.
2666 A better solution is to properly configure the firewall,
2667 but sometimes that is not allowed.
2672 This enables a generic 'hash' command which can produce
2673 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2677 Enable the hash verify command (hash -v). This adds to code
2680 CONFIG_SHA1 - support SHA1 hashing
2681 CONFIG_SHA256 - support SHA256 hashing
2683 Note: There is also a sha1sum command, which should perhaps
2684 be deprecated in favour of 'hash sha1'.
2686 - Freescale i.MX specific commands:
2687 CONFIG_CMD_HDMIDETECT
2688 This enables 'hdmidet' command which returns true if an
2689 HDMI monitor is detected. This command is i.MX 6 specific.
2692 This enables the 'bmode' (bootmode) command for forcing
2693 a boot from specific media.
2695 This is useful for forcing the ROM's usb downloader to
2696 activate upon a watchdog reset which is nice when iterating
2697 on U-Boot. Using the reset button or running bmode normal
2698 will set it back to normal. This command currently
2699 supports i.MX53 and i.MX6.
2704 This enables the RSA algorithm used for FIT image verification
2705 in U-Boot. See doc/uImage/signature for more information.
2707 The signing part is build into mkimage regardless of this
2711 - Show boot progress:
2712 CONFIG_SHOW_BOOT_PROGRESS
2714 Defining this option allows to add some board-
2715 specific code (calling a user-provided function
2716 "show_boot_progress(int)") that enables you to show
2717 the system's boot progress on some display (for
2718 example, some LED's) on your board. At the moment,
2719 the following checkpoints are implemented:
2721 - Detailed boot stage timing
2723 Define this option to get detailed timing of each stage
2724 of the boot process.
2726 CONFIG_BOOTSTAGE_USER_COUNT
2727 This is the number of available user bootstage records.
2728 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2729 a new ID will be allocated from this stash. If you exceed
2730 the limit, recording will stop.
2732 CONFIG_BOOTSTAGE_REPORT
2733 Define this to print a report before boot, similar to this:
2735 Timer summary in microseconds:
2738 3,575,678 3,575,678 board_init_f start
2739 3,575,695 17 arch_cpu_init A9
2740 3,575,777 82 arch_cpu_init done
2741 3,659,598 83,821 board_init_r start
2742 3,910,375 250,777 main_loop
2743 29,916,167 26,005,792 bootm_start
2744 30,361,327 445,160 start_kernel
2746 CONFIG_CMD_BOOTSTAGE
2747 Add a 'bootstage' command which supports printing a report
2748 and un/stashing of bootstage data.
2750 CONFIG_BOOTSTAGE_FDT
2751 Stash the bootstage information in the FDT. A root 'bootstage'
2752 node is created with each bootstage id as a child. Each child
2753 has a 'name' property and either 'mark' containing the
2754 mark time in microsecond, or 'accum' containing the
2755 accumulated time for that bootstage id in microseconds.
2760 name = "board_init_f";
2769 Code in the Linux kernel can find this in /proc/devicetree.
2771 Legacy uImage format:
2774 1 common/cmd_bootm.c before attempting to boot an image
2775 -1 common/cmd_bootm.c Image header has bad magic number
2776 2 common/cmd_bootm.c Image header has correct magic number
2777 -2 common/cmd_bootm.c Image header has bad checksum
2778 3 common/cmd_bootm.c Image header has correct checksum
2779 -3 common/cmd_bootm.c Image data has bad checksum
2780 4 common/cmd_bootm.c Image data has correct checksum
2781 -4 common/cmd_bootm.c Image is for unsupported architecture
2782 5 common/cmd_bootm.c Architecture check OK
2783 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2784 6 common/cmd_bootm.c Image Type check OK
2785 -6 common/cmd_bootm.c gunzip uncompression error
2786 -7 common/cmd_bootm.c Unimplemented compression type
2787 7 common/cmd_bootm.c Uncompression OK
2788 8 common/cmd_bootm.c No uncompress/copy overwrite error
2789 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2791 9 common/image.c Start initial ramdisk verification
2792 -10 common/image.c Ramdisk header has bad magic number
2793 -11 common/image.c Ramdisk header has bad checksum
2794 10 common/image.c Ramdisk header is OK
2795 -12 common/image.c Ramdisk data has bad checksum
2796 11 common/image.c Ramdisk data has correct checksum
2797 12 common/image.c Ramdisk verification complete, start loading
2798 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2799 13 common/image.c Start multifile image verification
2800 14 common/image.c No initial ramdisk, no multifile, continue.
2802 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2804 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2805 -31 post/post.c POST test failed, detected by post_output_backlog()
2806 -32 post/post.c POST test failed, detected by post_run_single()
2808 34 common/cmd_doc.c before loading a Image from a DOC device
2809 -35 common/cmd_doc.c Bad usage of "doc" command
2810 35 common/cmd_doc.c correct usage of "doc" command
2811 -36 common/cmd_doc.c No boot device
2812 36 common/cmd_doc.c correct boot device
2813 -37 common/cmd_doc.c Unknown Chip ID on boot device
2814 37 common/cmd_doc.c correct chip ID found, device available
2815 -38 common/cmd_doc.c Read Error on boot device
2816 38 common/cmd_doc.c reading Image header from DOC device OK
2817 -39 common/cmd_doc.c Image header has bad magic number
2818 39 common/cmd_doc.c Image header has correct magic number
2819 -40 common/cmd_doc.c Error reading Image from DOC device
2820 40 common/cmd_doc.c Image header has correct magic number
2821 41 common/cmd_ide.c before loading a Image from a IDE device
2822 -42 common/cmd_ide.c Bad usage of "ide" command
2823 42 common/cmd_ide.c correct usage of "ide" command
2824 -43 common/cmd_ide.c No boot device
2825 43 common/cmd_ide.c boot device found
2826 -44 common/cmd_ide.c Device not available
2827 44 common/cmd_ide.c Device available
2828 -45 common/cmd_ide.c wrong partition selected
2829 45 common/cmd_ide.c partition selected
2830 -46 common/cmd_ide.c Unknown partition table
2831 46 common/cmd_ide.c valid partition table found
2832 -47 common/cmd_ide.c Invalid partition type
2833 47 common/cmd_ide.c correct partition type
2834 -48 common/cmd_ide.c Error reading Image Header on boot device
2835 48 common/cmd_ide.c reading Image Header from IDE device OK
2836 -49 common/cmd_ide.c Image header has bad magic number
2837 49 common/cmd_ide.c Image header has correct magic number
2838 -50 common/cmd_ide.c Image header has bad checksum
2839 50 common/cmd_ide.c Image header has correct checksum
2840 -51 common/cmd_ide.c Error reading Image from IDE device
2841 51 common/cmd_ide.c reading Image from IDE device OK
2842 52 common/cmd_nand.c before loading a Image from a NAND device
2843 -53 common/cmd_nand.c Bad usage of "nand" command
2844 53 common/cmd_nand.c correct usage of "nand" command
2845 -54 common/cmd_nand.c No boot device
2846 54 common/cmd_nand.c boot device found
2847 -55 common/cmd_nand.c Unknown Chip ID on boot device
2848 55 common/cmd_nand.c correct chip ID found, device available
2849 -56 common/cmd_nand.c Error reading Image Header on boot device
2850 56 common/cmd_nand.c reading Image Header from NAND device OK
2851 -57 common/cmd_nand.c Image header has bad magic number
2852 57 common/cmd_nand.c Image header has correct magic number
2853 -58 common/cmd_nand.c Error reading Image from NAND device
2854 58 common/cmd_nand.c reading Image from NAND device OK
2856 -60 common/env_common.c Environment has a bad CRC, using default
2858 64 net/eth.c starting with Ethernet configuration.
2859 -64 net/eth.c no Ethernet found.
2860 65 net/eth.c Ethernet found.
2862 -80 common/cmd_net.c usage wrong
2863 80 common/cmd_net.c before calling NetLoop()
2864 -81 common/cmd_net.c some error in NetLoop() occurred
2865 81 common/cmd_net.c NetLoop() back without error
2866 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2867 82 common/cmd_net.c trying automatic boot
2868 83 common/cmd_net.c running "source" command
2869 -83 common/cmd_net.c some error in automatic boot or "source" command
2870 84 common/cmd_net.c end without errors
2875 100 common/cmd_bootm.c Kernel FIT Image has correct format
2876 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2877 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2878 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2879 102 common/cmd_bootm.c Kernel unit name specified
2880 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2881 103 common/cmd_bootm.c Found configuration node
2882 104 common/cmd_bootm.c Got kernel subimage node offset
2883 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2884 105 common/cmd_bootm.c Kernel subimage hash verification OK
2885 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2886 106 common/cmd_bootm.c Architecture check OK
2887 -106 common/cmd_bootm.c Kernel subimage has wrong type
2888 107 common/cmd_bootm.c Kernel subimage type OK
2889 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2890 108 common/cmd_bootm.c Got kernel subimage data/size
2891 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2892 -109 common/cmd_bootm.c Can't get kernel subimage type
2893 -110 common/cmd_bootm.c Can't get kernel subimage comp
2894 -111 common/cmd_bootm.c Can't get kernel subimage os
2895 -112 common/cmd_bootm.c Can't get kernel subimage load address
2896 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2898 120 common/image.c Start initial ramdisk verification
2899 -120 common/image.c Ramdisk FIT image has incorrect format
2900 121 common/image.c Ramdisk FIT image has correct format
2901 122 common/image.c No ramdisk subimage unit name, using configuration
2902 -122 common/image.c Can't get configuration for ramdisk subimage
2903 123 common/image.c Ramdisk unit name specified
2904 -124 common/image.c Can't get ramdisk subimage node offset
2905 125 common/image.c Got ramdisk subimage node offset
2906 -125 common/image.c Ramdisk subimage hash verification failed
2907 126 common/image.c Ramdisk subimage hash verification OK
2908 -126 common/image.c Ramdisk subimage for unsupported architecture
2909 127 common/image.c Architecture check OK
2910 -127 common/image.c Can't get ramdisk subimage data/size
2911 128 common/image.c Got ramdisk subimage data/size
2912 129 common/image.c Can't get ramdisk load address
2913 -129 common/image.c Got ramdisk load address
2915 -130 common/cmd_doc.c Incorrect FIT image format
2916 131 common/cmd_doc.c FIT image format OK
2918 -140 common/cmd_ide.c Incorrect FIT image format
2919 141 common/cmd_ide.c FIT image format OK
2921 -150 common/cmd_nand.c Incorrect FIT image format
2922 151 common/cmd_nand.c FIT image format OK
2924 - FIT image support:
2926 Enable support for the FIT uImage format.
2928 CONFIG_FIT_BEST_MATCH
2929 When no configuration is explicitly selected, default to the
2930 one whose fdt's compatibility field best matches that of
2931 U-Boot itself. A match is considered "best" if it matches the
2932 most specific compatibility entry of U-Boot's fdt's root node.
2933 The order of entries in the configuration's fdt is ignored.
2935 CONFIG_FIT_SIGNATURE
2936 This option enables signature verification of FIT uImages,
2937 using a hash signed and verified using RSA. See
2938 doc/uImage.FIT/signature.txt for more details.
2940 - Standalone program support:
2941 CONFIG_STANDALONE_LOAD_ADDR
2943 This option defines a board specific value for the
2944 address where standalone program gets loaded, thus
2945 overwriting the architecture dependent default
2948 - Frame Buffer Address:
2951 Define CONFIG_FB_ADDR if you want to use specific
2952 address for frame buffer. This is typically the case
2953 when using a graphics controller has separate video
2954 memory. U-Boot will then place the frame buffer at
2955 the given address instead of dynamically reserving it
2956 in system RAM by calling lcd_setmem(), which grabs
2957 the memory for the frame buffer depending on the
2958 configured panel size.
2960 Please see board_init_f function.
2962 - Automatic software updates via TFTP server
2964 CONFIG_UPDATE_TFTP_CNT_MAX
2965 CONFIG_UPDATE_TFTP_MSEC_MAX
2967 These options enable and control the auto-update feature;
2968 for a more detailed description refer to doc/README.update.
2970 - MTD Support (mtdparts command, UBI support)
2973 Adds the MTD device infrastructure from the Linux kernel.
2974 Needed for mtdparts command support.
2976 CONFIG_MTD_PARTITIONS
2978 Adds the MTD partitioning infrastructure from the Linux
2979 kernel. Needed for UBI support.
2984 Adds commands for interacting with MTD partitions formatted
2985 with the UBI flash translation layer
2987 Requires also defining CONFIG_RBTREE
2989 CONFIG_UBI_SILENCE_MSG
2991 Make the verbose messages from UBI stop printing. This leaves
2992 warnings and errors enabled.
2997 Adds commands for interacting with UBI volumes formatted as
2998 UBIFS. UBIFS is read-only in u-boot.
3000 Requires UBI support as well as CONFIG_LZO
3002 CONFIG_UBIFS_SILENCE_MSG
3004 Make the verbose messages from UBIFS stop printing. This leaves
3005 warnings and errors enabled.
3009 Enable building of SPL globally.
3012 LDSCRIPT for linking the SPL binary.
3014 CONFIG_SPL_MAX_FOOTPRINT
3015 Maximum size in memory allocated to the SPL, BSS included.
3016 When defined, the linker checks that the actual memory
3017 used by SPL from _start to __bss_end does not exceed it.
3018 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3019 must not be both defined at the same time.
3022 Maximum size of the SPL image (text, data, rodata, and
3023 linker lists sections), BSS excluded.
3024 When defined, the linker checks that the actual size does
3027 CONFIG_SPL_TEXT_BASE
3028 TEXT_BASE for linking the SPL binary.
3030 CONFIG_SPL_RELOC_TEXT_BASE
3031 Address to relocate to. If unspecified, this is equal to
3032 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3034 CONFIG_SPL_BSS_START_ADDR
3035 Link address for the BSS within the SPL binary.
3037 CONFIG_SPL_BSS_MAX_SIZE
3038 Maximum size in memory allocated to the SPL BSS.
3039 When defined, the linker checks that the actual memory used
3040 by SPL from __bss_start to __bss_end does not exceed it.
3041 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3042 must not be both defined at the same time.
3045 Adress of the start of the stack SPL will use
3047 CONFIG_SPL_RELOC_STACK
3048 Adress of the start of the stack SPL will use after
3049 relocation. If unspecified, this is equal to
3052 CONFIG_SYS_SPL_MALLOC_START
3053 Starting address of the malloc pool used in SPL.
3055 CONFIG_SYS_SPL_MALLOC_SIZE
3056 The size of the malloc pool used in SPL.
3058 CONFIG_SPL_FRAMEWORK
3059 Enable the SPL framework under common/. This framework
3060 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3061 NAND loading of the Linux Kernel.
3063 CONFIG_SPL_DISPLAY_PRINT
3064 For ARM, enable an optional function to print more information
3065 about the running system.
3067 CONFIG_SPL_INIT_MINIMAL
3068 Arch init code should be built for a very small image
3070 CONFIG_SPL_LIBCOMMON_SUPPORT
3071 Support for common/libcommon.o in SPL binary
3073 CONFIG_SPL_LIBDISK_SUPPORT
3074 Support for disk/libdisk.o in SPL binary
3076 CONFIG_SPL_I2C_SUPPORT
3077 Support for drivers/i2c/libi2c.o in SPL binary
3079 CONFIG_SPL_GPIO_SUPPORT
3080 Support for drivers/gpio/libgpio.o in SPL binary
3082 CONFIG_SPL_MMC_SUPPORT
3083 Support for drivers/mmc/libmmc.o in SPL binary
3085 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3086 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3087 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3088 Address, size and partition on the MMC to load U-Boot from
3089 when the MMC is being used in raw mode.
3091 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3092 Sector to load kernel uImage from when MMC is being
3093 used in raw mode (for Falcon mode)
3095 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3096 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3097 Sector and number of sectors to load kernel argument
3098 parameters from when MMC is being used in raw mode
3101 CONFIG_SPL_FAT_SUPPORT
3102 Support for fs/fat/libfat.o in SPL binary
3104 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3105 Filename to read to load U-Boot when reading from FAT
3107 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3108 Filename to read to load kernel uImage when reading
3109 from FAT (for Falcon mode)
3111 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3112 Filename to read to load kernel argument parameters
3113 when reading from FAT (for Falcon mode)
3115 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3116 Set this for NAND SPL on PPC mpc83xx targets, so that
3117 start.S waits for the rest of the SPL to load before
3118 continuing (the hardware starts execution after just
3119 loading the first page rather than the full 4K).
3121 CONFIG_SPL_NAND_BASE
3122 Include nand_base.c in the SPL. Requires
3123 CONFIG_SPL_NAND_DRIVERS.
3125 CONFIG_SPL_NAND_DRIVERS
3126 SPL uses normal NAND drivers, not minimal drivers.
3129 Include standard software ECC in the SPL
3131 CONFIG_SPL_NAND_SIMPLE
3132 Support for NAND boot using simple NAND drivers that
3133 expose the cmd_ctrl() interface.
3135 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3136 Set for the SPL on PPC mpc8xxx targets, support for
3137 arch/powerpc/cpu/mpc8xxx/ddr/libddr.o in SPL binary.
3139 CONFIG_SPL_COMMON_INIT_DDR
3140 Set for common ddr init with serial presence detect in
3143 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3144 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3145 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3146 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3147 CONFIG_SYS_NAND_ECCBYTES
3148 Defines the size and behavior of the NAND that SPL uses
3151 CONFIG_SYS_NAND_U_BOOT_OFFS
3152 Location in NAND to read U-Boot from
3154 CONFIG_SYS_NAND_U_BOOT_DST
3155 Location in memory to load U-Boot to
3157 CONFIG_SYS_NAND_U_BOOT_SIZE
3158 Size of image to load
3160 CONFIG_SYS_NAND_U_BOOT_START
3161 Entry point in loaded image to jump to
3163 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3164 Define this if you need to first read the OOB and then the
3165 data. This is used for example on davinci plattforms.
3167 CONFIG_SPL_OMAP3_ID_NAND
3168 Support for an OMAP3-specific set of functions to return the
3169 ID and MFR of the first attached NAND chip, if present.
3171 CONFIG_SPL_SERIAL_SUPPORT
3172 Support for drivers/serial/libserial.o in SPL binary
3174 CONFIG_SPL_SPI_FLASH_SUPPORT
3175 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3177 CONFIG_SPL_SPI_SUPPORT
3178 Support for drivers/spi/libspi.o in SPL binary
3180 CONFIG_SPL_RAM_DEVICE
3181 Support for running image already present in ram, in SPL binary
3183 CONFIG_SPL_LIBGENERIC_SUPPORT
3184 Support for lib/libgeneric.o in SPL binary
3186 CONFIG_SPL_ENV_SUPPORT
3187 Support for the environment operating in SPL binary
3189 CONFIG_SPL_NET_SUPPORT
3190 Support for the net/libnet.o in SPL binary.
3191 It conflicts with SPL env from storage medium specified by
3192 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3195 Image offset to which the SPL should be padded before appending
3196 the SPL payload. By default, this is defined as
3197 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3198 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3199 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3202 Final target image containing SPL and payload. Some SPLs
3203 use an arch-specific makefile fragment instead, for
3204 example if more than one image needs to be produced.
3206 CONFIG_FIT_SPL_PRINT
3207 Printing information about a FIT image adds quite a bit of
3208 code to SPL. So this is normally disabled in SPL. Use this
3209 option to re-enable it. This will affect the output of the
3210 bootm command when booting a FIT image.
3214 Enable building of TPL globally.
3217 Image offset to which the TPL should be padded before appending
3218 the TPL payload. By default, this is defined as
3219 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3220 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3221 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3226 [so far only for SMDK2400 boards]
3228 - Modem support enable:
3229 CONFIG_MODEM_SUPPORT
3231 - RTS/CTS Flow control enable:
3234 - Modem debug support:
3235 CONFIG_MODEM_SUPPORT_DEBUG
3237 Enables debugging stuff (char screen[1024], dbg())
3238 for modem support. Useful only with BDI2000.
3240 - Interrupt support (PPC):
3242 There are common interrupt_init() and timer_interrupt()
3243 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3244 for CPU specific initialization. interrupt_init_cpu()
3245 should set decrementer_count to appropriate value. If
3246 CPU resets decrementer automatically after interrupt
3247 (ppc4xx) it should set decrementer_count to zero.
3248 timer_interrupt() calls timer_interrupt_cpu() for CPU
3249 specific handling. If board has watchdog / status_led
3250 / other_activity_monitor it works automatically from
3251 general timer_interrupt().
3255 In the target system modem support is enabled when a
3256 specific key (key combination) is pressed during
3257 power-on. Otherwise U-Boot will boot normally
3258 (autoboot). The key_pressed() function is called from
3259 board_init(). Currently key_pressed() is a dummy
3260 function, returning 1 and thus enabling modem
3263 If there are no modem init strings in the
3264 environment, U-Boot proceed to autoboot; the
3265 previous output (banner, info printfs) will be
3268 See also: doc/README.Modem
3270 Board initialization settings:
3271 ------------------------------
3273 During Initialization u-boot calls a number of board specific functions
3274 to allow the preparation of board specific prerequisites, e.g. pin setup
3275 before drivers are initialized. To enable these callbacks the
3276 following configuration macros have to be defined. Currently this is
3277 architecture specific, so please check arch/your_architecture/lib/board.c
3278 typically in board_init_f() and board_init_r().
3280 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3281 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3282 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3283 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3285 Configuration Settings:
3286 -----------------------
3288 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3289 undefine this when you're short of memory.
3291 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3292 width of the commands listed in the 'help' command output.
3294 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3295 prompt for user input.
3297 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3299 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3301 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3303 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3304 the application (usually a Linux kernel) when it is
3307 - CONFIG_SYS_BAUDRATE_TABLE:
3308 List of legal baudrate settings for this board.
3310 - CONFIG_SYS_CONSOLE_INFO_QUIET
3311 Suppress display of console information at boot.
3313 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3314 If the board specific function
3315 extern int overwrite_console (void);
3316 returns 1, the stdin, stderr and stdout are switched to the
3317 serial port, else the settings in the environment are used.
3319 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3320 Enable the call to overwrite_console().
3322 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3323 Enable overwrite of previous console environment settings.
3325 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3326 Begin and End addresses of the area used by the
3329 - CONFIG_SYS_ALT_MEMTEST:
3330 Enable an alternate, more extensive memory test.
3332 - CONFIG_SYS_MEMTEST_SCRATCH:
3333 Scratch address used by the alternate memory test
3334 You only need to set this if address zero isn't writeable
3336 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3337 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3338 this specified memory area will get subtracted from the top
3339 (end) of RAM and won't get "touched" at all by U-Boot. By
3340 fixing up gd->ram_size the Linux kernel should gets passed
3341 the now "corrected" memory size and won't touch it either.
3342 This should work for arch/ppc and arch/powerpc. Only Linux
3343 board ports in arch/powerpc with bootwrapper support that
3344 recalculate the memory size from the SDRAM controller setup
3345 will have to get fixed in Linux additionally.
3347 This option can be used as a workaround for the 440EPx/GRx
3348 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3351 WARNING: Please make sure that this value is a multiple of
3352 the Linux page size (normally 4k). If this is not the case,
3353 then the end address of the Linux memory will be located at a
3354 non page size aligned address and this could cause major
3357 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3358 Enable temporary baudrate change while serial download
3360 - CONFIG_SYS_SDRAM_BASE:
3361 Physical start address of SDRAM. _Must_ be 0 here.
3363 - CONFIG_SYS_MBIO_BASE:
3364 Physical start address of Motherboard I/O (if using a
3367 - CONFIG_SYS_FLASH_BASE:
3368 Physical start address of Flash memory.
3370 - CONFIG_SYS_MONITOR_BASE:
3371 Physical start address of boot monitor code (set by
3372 make config files to be same as the text base address
3373 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3374 CONFIG_SYS_FLASH_BASE when booting from flash.
3376 - CONFIG_SYS_MONITOR_LEN:
3377 Size of memory reserved for monitor code, used to
3378 determine _at_compile_time_ (!) if the environment is
3379 embedded within the U-Boot image, or in a separate
3382 - CONFIG_SYS_MALLOC_LEN:
3383 Size of DRAM reserved for malloc() use.
3385 - CONFIG_SYS_BOOTM_LEN:
3386 Normally compressed uImages are limited to an
3387 uncompressed size of 8 MBytes. If this is not enough,
3388 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3389 to adjust this setting to your needs.
3391 - CONFIG_SYS_BOOTMAPSZ:
3392 Maximum size of memory mapped by the startup code of
3393 the Linux kernel; all data that must be processed by
3394 the Linux kernel (bd_info, boot arguments, FDT blob if
3395 used) must be put below this limit, unless "bootm_low"
3396 environment variable is defined and non-zero. In such case
3397 all data for the Linux kernel must be between "bootm_low"
3398 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3399 variable "bootm_mapsize" will override the value of
3400 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3401 then the value in "bootm_size" will be used instead.
3403 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3404 Enable initrd_high functionality. If defined then the
3405 initrd_high feature is enabled and the bootm ramdisk subcommand
3408 - CONFIG_SYS_BOOT_GET_CMDLINE:
3409 Enables allocating and saving kernel cmdline in space between
3410 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3412 - CONFIG_SYS_BOOT_GET_KBD:
3413 Enables allocating and saving a kernel copy of the bd_info in
3414 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3416 - CONFIG_SYS_MAX_FLASH_BANKS:
3417 Max number of Flash memory banks
3419 - CONFIG_SYS_MAX_FLASH_SECT:
3420 Max number of sectors on a Flash chip
3422 - CONFIG_SYS_FLASH_ERASE_TOUT:
3423 Timeout for Flash erase operations (in ms)
3425 - CONFIG_SYS_FLASH_WRITE_TOUT:
3426 Timeout for Flash write operations (in ms)
3428 - CONFIG_SYS_FLASH_LOCK_TOUT
3429 Timeout for Flash set sector lock bit operation (in ms)
3431 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3432 Timeout for Flash clear lock bits operation (in ms)
3434 - CONFIG_SYS_FLASH_PROTECTION
3435 If defined, hardware flash sectors protection is used
3436 instead of U-Boot software protection.
3438 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3440 Enable TFTP transfers directly to flash memory;
3441 without this option such a download has to be
3442 performed in two steps: (1) download to RAM, and (2)
3443 copy from RAM to flash.
3445 The two-step approach is usually more reliable, since
3446 you can check if the download worked before you erase
3447 the flash, but in some situations (when system RAM is
3448 too limited to allow for a temporary copy of the
3449 downloaded image) this option may be very useful.
3451 - CONFIG_SYS_FLASH_CFI:
3452 Define if the flash driver uses extra elements in the
3453 common flash structure for storing flash geometry.
3455 - CONFIG_FLASH_CFI_DRIVER
3456 This option also enables the building of the cfi_flash driver
3457 in the drivers directory
3459 - CONFIG_FLASH_CFI_MTD
3460 This option enables the building of the cfi_mtd driver
3461 in the drivers directory. The driver exports CFI flash
3464 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3465 Use buffered writes to flash.
3467 - CONFIG_FLASH_SPANSION_S29WS_N
3468 s29ws-n MirrorBit flash has non-standard addresses for buffered
3471 - CONFIG_SYS_FLASH_QUIET_TEST
3472 If this option is defined, the common CFI flash doesn't
3473 print it's warning upon not recognized FLASH banks. This
3474 is useful, if some of the configured banks are only
3475 optionally available.
3477 - CONFIG_FLASH_SHOW_PROGRESS
3478 If defined (must be an integer), print out countdown
3479 digits and dots. Recommended value: 45 (9..1) for 80
3480 column displays, 15 (3..1) for 40 column displays.
3482 - CONFIG_FLASH_VERIFY
3483 If defined, the content of the flash (destination) is compared
3484 against the source after the write operation. An error message
3485 will be printed when the contents are not identical.
3486 Please note that this option is useless in nearly all cases,
3487 since such flash programming errors usually are detected earlier
3488 while unprotecting/erasing/programming. Please only enable
3489 this option if you really know what you are doing.
3491 - CONFIG_SYS_RX_ETH_BUFFER:
3492 Defines the number of Ethernet receive buffers. On some
3493 Ethernet controllers it is recommended to set this value
3494 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3495 buffers can be full shortly after enabling the interface
3496 on high Ethernet traffic.
3497 Defaults to 4 if not defined.
3499 - CONFIG_ENV_MAX_ENTRIES
3501 Maximum number of entries in the hash table that is used
3502 internally to store the environment settings. The default
3503 setting is supposed to be generous and should work in most
3504 cases. This setting can be used to tune behaviour; see
3505 lib/hashtable.c for details.
3507 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3508 - CONFIG_ENV_FLAGS_LIST_STATIC
3509 Enable validation of the values given to environment variables when
3510 calling env set. Variables can be restricted to only decimal,
3511 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3512 the variables can also be restricted to IP address or MAC address.
3514 The format of the list is:
3515 type_attribute = [s|d|x|b|i|m]
3516 access_atribute = [a|r|o|c]
3517 attributes = type_attribute[access_atribute]
3518 entry = variable_name[:attributes]
3521 The type attributes are:
3522 s - String (default)
3525 b - Boolean ([1yYtT|0nNfF])
3529 The access attributes are:
3535 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3536 Define this to a list (string) to define the ".flags"
3537 envirnoment variable in the default or embedded environment.
3539 - CONFIG_ENV_FLAGS_LIST_STATIC
3540 Define this to a list (string) to define validation that
3541 should be done if an entry is not found in the ".flags"
3542 environment variable. To override a setting in the static
3543 list, simply add an entry for the same variable name to the
3546 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3547 If defined, don't allow the -f switch to env set override variable
3550 - CONFIG_SYS_GENERIC_BOARD
3551 This selects the architecture-generic board system instead of the
3552 architecture-specific board files. It is intended to move boards
3553 to this new framework over time. Defining this will disable the
3554 arch/foo/lib/board.c file and use common/board_f.c and
3555 common/board_r.c instead. To use this option your architecture
3556 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3557 its config.mk file). If you find problems enabling this option on
3558 your board please report the problem and send patches!
3560 - CONFIG_SYS_SYM_OFFSETS
3561 This is set by architectures that use offsets for link symbols
3562 instead of absolute values. So bss_start is obtained using an
3563 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3564 directly. You should not need to touch this setting.
3566 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3567 This is set by OMAP boards for the max time that reset should
3568 be asserted. See doc/README.omap-reset-time for details on how
3569 the value can be calulated on a given board.
3571 The following definitions that deal with the placement and management
3572 of environment data (variable area); in general, we support the
3573 following configurations:
3575 - CONFIG_BUILD_ENVCRC:
3577 Builds up envcrc with the target environment so that external utils
3578 may easily extract it and embed it in final U-Boot images.
3580 - CONFIG_ENV_IS_IN_FLASH:
3582 Define this if the environment is in flash memory.
3584 a) The environment occupies one whole flash sector, which is
3585 "embedded" in the text segment with the U-Boot code. This
3586 happens usually with "bottom boot sector" or "top boot
3587 sector" type flash chips, which have several smaller
3588 sectors at the start or the end. For instance, such a
3589 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3590 such a case you would place the environment in one of the
3591 4 kB sectors - with U-Boot code before and after it. With
3592 "top boot sector" type flash chips, you would put the
3593 environment in one of the last sectors, leaving a gap
3594 between U-Boot and the environment.
3596 - CONFIG_ENV_OFFSET:
3598 Offset of environment data (variable area) to the
3599 beginning of flash memory; for instance, with bottom boot
3600 type flash chips the second sector can be used: the offset
3601 for this sector is given here.
3603 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3607 This is just another way to specify the start address of
3608 the flash sector containing the environment (instead of
3611 - CONFIG_ENV_SECT_SIZE:
3613 Size of the sector containing the environment.
3616 b) Sometimes flash chips have few, equal sized, BIG sectors.
3617 In such a case you don't want to spend a whole sector for
3622 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3623 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3624 of this flash sector for the environment. This saves
3625 memory for the RAM copy of the environment.
3627 It may also save flash memory if you decide to use this
3628 when your environment is "embedded" within U-Boot code,
3629 since then the remainder of the flash sector could be used
3630 for U-Boot code. It should be pointed out that this is
3631 STRONGLY DISCOURAGED from a robustness point of view:
3632 updating the environment in flash makes it always
3633 necessary to erase the WHOLE sector. If something goes
3634 wrong before the contents has been restored from a copy in
3635 RAM, your target system will be dead.
3637 - CONFIG_ENV_ADDR_REDUND
3638 CONFIG_ENV_SIZE_REDUND
3640 These settings describe a second storage area used to hold
3641 a redundant copy of the environment data, so that there is
3642 a valid backup copy in case there is a power failure during
3643 a "saveenv" operation.
3645 BE CAREFUL! Any changes to the flash layout, and some changes to the
3646 source code will make it necessary to adapt <board>/u-boot.lds*
3650 - CONFIG_ENV_IS_IN_NVRAM:
3652 Define this if you have some non-volatile memory device
3653 (NVRAM, battery buffered SRAM) which you want to use for the
3659 These two #defines are used to determine the memory area you
3660 want to use for environment. It is assumed that this memory
3661 can just be read and written to, without any special
3664 BE CAREFUL! The first access to the environment happens quite early
3665 in U-Boot initalization (when we try to get the setting of for the
3666 console baudrate). You *MUST* have mapped your NVRAM area then, or
3669 Please note that even with NVRAM we still use a copy of the
3670 environment in RAM: we could work on NVRAM directly, but we want to
3671 keep settings there always unmodified except somebody uses "saveenv"
3672 to save the current settings.
3675 - CONFIG_ENV_IS_IN_EEPROM:
3677 Use this if you have an EEPROM or similar serial access
3678 device and a driver for it.
3680 - CONFIG_ENV_OFFSET:
3683 These two #defines specify the offset and size of the
3684 environment area within the total memory of your EEPROM.
3686 - CONFIG_SYS_I2C_EEPROM_ADDR:
3687 If defined, specified the chip address of the EEPROM device.
3688 The default address is zero.
3690 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3691 If defined, the number of bits used to address bytes in a
3692 single page in the EEPROM device. A 64 byte page, for example
3693 would require six bits.
3695 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3696 If defined, the number of milliseconds to delay between
3697 page writes. The default is zero milliseconds.
3699 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3700 The length in bytes of the EEPROM memory array address. Note
3701 that this is NOT the chip address length!
3703 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3704 EEPROM chips that implement "address overflow" are ones
3705 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3706 address and the extra bits end up in the "chip address" bit
3707 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3710 Note that we consider the length of the address field to
3711 still be one byte because the extra address bits are hidden
3712 in the chip address.
3714 - CONFIG_SYS_EEPROM_SIZE:
3715 The size in bytes of the EEPROM device.
3717 - CONFIG_ENV_EEPROM_IS_ON_I2C
3718 define this, if you have I2C and SPI activated, and your
3719 EEPROM, which holds the environment, is on the I2C bus.
3721 - CONFIG_I2C_ENV_EEPROM_BUS
3722 if you have an Environment on an EEPROM reached over
3723 I2C muxes, you can define here, how to reach this
3724 EEPROM. For example:
3726 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3728 EEPROM which holds the environment, is reached over
3729 a pca9547 i2c mux with address 0x70, channel 3.
3731 - CONFIG_ENV_IS_IN_DATAFLASH:
3733 Define this if you have a DataFlash memory device which you
3734 want to use for the environment.
3736 - CONFIG_ENV_OFFSET:
3740 These three #defines specify the offset and size of the
3741 environment area within the total memory of your DataFlash placed
3742 at the specified address.
3744 - CONFIG_ENV_IS_IN_REMOTE:
3746 Define this if you have a remote memory space which you
3747 want to use for the local device's environment.
3752 These two #defines specify the address and size of the
3753 environment area within the remote memory space. The
3754 local device can get the environment from remote memory
3755 space by SRIO or PCIE links.
3757 BE CAREFUL! For some special cases, the local device can not use
3758 "saveenv" command. For example, the local device will get the
3759 environment stored in a remote NOR flash by SRIO or PCIE link,
3760 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3762 - CONFIG_ENV_IS_IN_NAND:
3764 Define this if you have a NAND device which you want to use
3765 for the environment.
3767 - CONFIG_ENV_OFFSET:
3770 These two #defines specify the offset and size of the environment
3771 area within the first NAND device. CONFIG_ENV_OFFSET must be
3772 aligned to an erase block boundary.
3774 - CONFIG_ENV_OFFSET_REDUND (optional):
3776 This setting describes a second storage area of CONFIG_ENV_SIZE
3777 size used to hold a redundant copy of the environment data, so
3778 that there is a valid backup copy in case there is a power failure
3779 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3780 aligned to an erase block boundary.
3782 - CONFIG_ENV_RANGE (optional):
3784 Specifies the length of the region in which the environment
3785 can be written. This should be a multiple of the NAND device's
3786 block size. Specifying a range with more erase blocks than
3787 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3788 the range to be avoided.
3790 - CONFIG_ENV_OFFSET_OOB (optional):
3792 Enables support for dynamically retrieving the offset of the
3793 environment from block zero's out-of-band data. The
3794 "nand env.oob" command can be used to record this offset.
3795 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3796 using CONFIG_ENV_OFFSET_OOB.
3798 - CONFIG_NAND_ENV_DST
3800 Defines address in RAM to which the nand_spl code should copy the
3801 environment. If redundant environment is used, it will be copied to
3802 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3804 - CONFIG_ENV_IS_IN_UBI:
3806 Define this if you have an UBI volume that you want to use for the
3807 environment. This has the benefit of wear-leveling the environment
3808 accesses, which is important on NAND.
3810 - CONFIG_ENV_UBI_PART:
3812 Define this to a string that is the mtd partition containing the UBI.
3814 - CONFIG_ENV_UBI_VOLUME:
3816 Define this to the name of the volume that you want to store the
3819 - CONFIG_ENV_UBI_VOLUME_REDUND:
3821 Define this to the name of another volume to store a second copy of
3822 the environment in. This will enable redundant environments in UBI.
3823 It is assumed that both volumes are in the same MTD partition.
3825 - CONFIG_UBI_SILENCE_MSG
3826 - CONFIG_UBIFS_SILENCE_MSG
3828 You will probably want to define these to avoid a really noisy system
3829 when storing the env in UBI.
3831 - CONFIG_ENV_IS_IN_MMC:
3833 Define this if you have an MMC device which you want to use for the
3836 - CONFIG_SYS_MMC_ENV_DEV:
3838 Specifies which MMC device the environment is stored in.
3840 - CONFIG_SYS_MMC_ENV_PART (optional):
3842 Specifies which MMC partition the environment is stored in. If not
3843 set, defaults to partition 0, the user area. Common values might be
3844 1 (first MMC boot partition), 2 (second MMC boot partition).
3846 - CONFIG_ENV_OFFSET:
3849 These two #defines specify the offset and size of the environment
3850 area within the specified MMC device.
3852 If offset is positive (the usual case), it is treated as relative to
3853 the start of the MMC partition. If offset is negative, it is treated
3854 as relative to the end of the MMC partition. This can be useful if
3855 your board may be fitted with different MMC devices, which have
3856 different sizes for the MMC partitions, and you always want the
3857 environment placed at the very end of the partition, to leave the
3858 maximum possible space before it, to store other data.
3860 These two values are in units of bytes, but must be aligned to an
3861 MMC sector boundary.
3863 - CONFIG_ENV_OFFSET_REDUND (optional):
3865 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3866 hold a redundant copy of the environment data. This provides a
3867 valid backup copy in case the other copy is corrupted, e.g. due
3868 to a power failure during a "saveenv" operation.
3870 This value may also be positive or negative; this is handled in the
3871 same way as CONFIG_ENV_OFFSET.
3873 This value is also in units of bytes, but must also be aligned to
3874 an MMC sector boundary.
3876 - CONFIG_ENV_SIZE_REDUND (optional):
3878 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3879 set. If this value is set, it must be set to the same value as
3882 - CONFIG_SYS_SPI_INIT_OFFSET
3884 Defines offset to the initial SPI buffer area in DPRAM. The
3885 area is used at an early stage (ROM part) if the environment
3886 is configured to reside in the SPI EEPROM: We need a 520 byte
3887 scratch DPRAM area. It is used between the two initialization
3888 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3889 to be a good choice since it makes it far enough from the
3890 start of the data area as well as from the stack pointer.
3892 Please note that the environment is read-only until the monitor
3893 has been relocated to RAM and a RAM copy of the environment has been
3894 created; also, when using EEPROM you will have to use getenv_f()
3895 until then to read environment variables.
3897 The environment is protected by a CRC32 checksum. Before the monitor
3898 is relocated into RAM, as a result of a bad CRC you will be working
3899 with the compiled-in default environment - *silently*!!! [This is
3900 necessary, because the first environment variable we need is the
3901 "baudrate" setting for the console - if we have a bad CRC, we don't
3902 have any device yet where we could complain.]
3904 Note: once the monitor has been relocated, then it will complain if
3905 the default environment is used; a new CRC is computed as soon as you
3906 use the "saveenv" command to store a valid environment.
3908 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3909 Echo the inverted Ethernet link state to the fault LED.
3911 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3912 also needs to be defined.
3914 - CONFIG_SYS_FAULT_MII_ADDR:
3915 MII address of the PHY to check for the Ethernet link state.
3917 - CONFIG_NS16550_MIN_FUNCTIONS:
3918 Define this if you desire to only have use of the NS16550_init
3919 and NS16550_putc functions for the serial driver located at
3920 drivers/serial/ns16550.c. This option is useful for saving
3921 space for already greatly restricted images, including but not
3922 limited to NAND_SPL configurations.
3924 - CONFIG_DISPLAY_BOARDINFO
3925 Display information about the board that U-Boot is running on
3926 when U-Boot starts up. The board function checkboard() is called
3929 - CONFIG_DISPLAY_BOARDINFO_LATE
3930 Similar to the previous option, but display this information
3931 later, once stdio is running and output goes to the LCD, if
3934 Low Level (hardware related) configuration options:
3935 ---------------------------------------------------
3937 - CONFIG_SYS_CACHELINE_SIZE:
3938 Cache Line Size of the CPU.
3940 - CONFIG_SYS_DEFAULT_IMMR:
3941 Default address of the IMMR after system reset.
3943 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3944 and RPXsuper) to be able to adjust the position of
3945 the IMMR register after a reset.
3947 - CONFIG_SYS_CCSRBAR_DEFAULT:
3948 Default (power-on reset) physical address of CCSR on Freescale
3951 - CONFIG_SYS_CCSRBAR:
3952 Virtual address of CCSR. On a 32-bit build, this is typically
3953 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3955 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3956 for cross-platform code that uses that macro instead.
3958 - CONFIG_SYS_CCSRBAR_PHYS:
3959 Physical address of CCSR. CCSR can be relocated to a new
3960 physical address, if desired. In this case, this macro should
3961 be set to that address. Otherwise, it should be set to the
3962 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3963 is typically relocated on 36-bit builds. It is recommended
3964 that this macro be defined via the _HIGH and _LOW macros:
3966 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3967 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3969 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3970 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3971 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3972 used in assembly code, so it must not contain typecasts or
3973 integer size suffixes (e.g. "ULL").
3975 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3976 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3977 used in assembly code, so it must not contain typecasts or
3978 integer size suffixes (e.g. "ULL").
3980 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3981 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3982 forced to a value that ensures that CCSR is not relocated.
3984 - Floppy Disk Support:
3985 CONFIG_SYS_FDC_DRIVE_NUMBER
3987 the default drive number (default value 0)
3989 CONFIG_SYS_ISA_IO_STRIDE
3991 defines the spacing between FDC chipset registers
3994 CONFIG_SYS_ISA_IO_OFFSET
3996 defines the offset of register from address. It
3997 depends on which part of the data bus is connected to
3998 the FDC chipset. (default value 0)
4000 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4001 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4004 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4005 fdc_hw_init() is called at the beginning of the FDC
4006 setup. fdc_hw_init() must be provided by the board
4007 source code. It is used to make hardware dependant
4011 Most IDE controllers were designed to be connected with PCI
4012 interface. Only few of them were designed for AHB interface.
4013 When software is doing ATA command and data transfer to
4014 IDE devices through IDE-AHB controller, some additional
4015 registers accessing to these kind of IDE-AHB controller
4018 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4019 DO NOT CHANGE unless you know exactly what you're
4020 doing! (11-4) [MPC8xx/82xx systems only]
4022 - CONFIG_SYS_INIT_RAM_ADDR:
4024 Start address of memory area that can be used for
4025 initial data and stack; please note that this must be
4026 writable memory that is working WITHOUT special
4027 initialization, i. e. you CANNOT use normal RAM which
4028 will become available only after programming the
4029 memory controller and running certain initialization
4032 U-Boot uses the following memory types:
4033 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4034 - MPC824X: data cache
4035 - PPC4xx: data cache
4037 - CONFIG_SYS_GBL_DATA_OFFSET:
4039 Offset of the initial data structure in the memory
4040 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4041 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4042 data is located at the end of the available space
4043 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4044 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4045 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4046 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4049 On the MPC824X (or other systems that use the data
4050 cache for initial memory) the address chosen for
4051 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4052 point to an otherwise UNUSED address space between
4053 the top of RAM and the start of the PCI space.
4055 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4057 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4059 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4061 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4063 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4065 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4067 - CONFIG_SYS_OR_TIMING_SDRAM:
4070 - CONFIG_SYS_MAMR_PTA:
4071 periodic timer for refresh
4073 - CONFIG_SYS_DER: Debug Event Register (37-47)
4075 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4076 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4077 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4078 CONFIG_SYS_BR1_PRELIM:
4079 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4081 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4082 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4083 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4084 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4086 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4087 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4088 Machine Mode Register and Memory Periodic Timer
4089 Prescaler definitions (SDRAM timing)
4091 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4092 enable I2C microcode relocation patch (MPC8xx);
4093 define relocation offset in DPRAM [DSP2]
4095 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4096 enable SMC microcode relocation patch (MPC8xx);
4097 define relocation offset in DPRAM [SMC1]
4099 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4100 enable SPI microcode relocation patch (MPC8xx);
4101 define relocation offset in DPRAM [SCC4]
4103 - CONFIG_SYS_USE_OSCCLK:
4104 Use OSCM clock mode on MBX8xx board. Be careful,
4105 wrong setting might damage your board. Read
4106 doc/README.MBX before setting this variable!
4108 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4109 Offset of the bootmode word in DPRAM used by post
4110 (Power On Self Tests). This definition overrides
4111 #define'd default value in commproc.h resp.
4114 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4115 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4116 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4117 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4118 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4119 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4120 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4121 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4122 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4124 - CONFIG_PCI_DISABLE_PCIE:
4125 Disable PCI-Express on systems where it is supported but not
4128 - CONFIG_PCI_ENUM_ONLY
4129 Only scan through and get the devices on the busses.
4130 Don't do any setup work, presumably because someone or
4131 something has already done it, and we don't need to do it
4132 a second time. Useful for platforms that are pre-booted
4133 by coreboot or similar.
4135 - CONFIG_PCI_INDIRECT_BRIDGE:
4136 Enable support for indirect PCI bridges.
4139 Chip has SRIO or not
4142 Board has SRIO 1 port available
4145 Board has SRIO 2 port available
4147 - CONFIG_SRIO_PCIE_BOOT_MASTER
4148 Board can support master function for Boot from SRIO and PCIE
4150 - CONFIG_SYS_SRIOn_MEM_VIRT:
4151 Virtual Address of SRIO port 'n' memory region
4153 - CONFIG_SYS_SRIOn_MEM_PHYS:
4154 Physical Address of SRIO port 'n' memory region
4156 - CONFIG_SYS_SRIOn_MEM_SIZE:
4157 Size of SRIO port 'n' memory region
4159 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4160 Defined to tell the NAND controller that the NAND chip is using
4162 Not all NAND drivers use this symbol.
4163 Example of drivers that use it:
4164 - drivers/mtd/nand/ndfc.c
4165 - drivers/mtd/nand/mxc_nand.c
4167 - CONFIG_SYS_NDFC_EBC0_CFG
4168 Sets the EBC0_CFG register for the NDFC. If not defined
4169 a default value will be used.
4172 Get DDR timing information from an I2C EEPROM. Common
4173 with pluggable memory modules such as SODIMMs
4176 I2C address of the SPD EEPROM
4178 - CONFIG_SYS_SPD_BUS_NUM
4179 If SPD EEPROM is on an I2C bus other than the first
4180 one, specify here. Note that the value must resolve
4181 to something your driver can deal with.
4183 - CONFIG_SYS_DDR_RAW_TIMING
4184 Get DDR timing information from other than SPD. Common with
4185 soldered DDR chips onboard without SPD. DDR raw timing
4186 parameters are extracted from datasheet and hard-coded into
4187 header files or board specific files.
4189 - CONFIG_FSL_DDR_INTERACTIVE
4190 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4192 - CONFIG_SYS_83XX_DDR_USES_CS0
4193 Only for 83xx systems. If specified, then DDR should
4194 be configured using CS0 and CS1 instead of CS2 and CS3.
4196 - CONFIG_ETHER_ON_FEC[12]
4197 Define to enable FEC[12] on a 8xx series processor.
4199 - CONFIG_FEC[12]_PHY
4200 Define to the hardcoded PHY address which corresponds
4201 to the given FEC; i. e.
4202 #define CONFIG_FEC1_PHY 4
4203 means that the PHY with address 4 is connected to FEC1
4205 When set to -1, means to probe for first available.
4207 - CONFIG_FEC[12]_PHY_NORXERR
4208 The PHY does not have a RXERR line (RMII only).
4209 (so program the FEC to ignore it).
4212 Enable RMII mode for all FECs.
4213 Note that this is a global option, we can't
4214 have one FEC in standard MII mode and another in RMII mode.
4216 - CONFIG_CRC32_VERIFY
4217 Add a verify option to the crc32 command.
4220 => crc32 -v <address> <count> <crc32>
4222 Where address/count indicate a memory area
4223 and crc32 is the correct crc32 which the
4227 Add the "loopw" memory command. This only takes effect if
4228 the memory commands are activated globally (CONFIG_CMD_MEM).
4231 Add the "mdc" and "mwc" memory commands. These are cyclic
4236 This command will print 4 bytes (10,11,12,13) each 500 ms.
4238 => mwc.l 100 12345678 10
4239 This command will write 12345678 to address 100 all 10 ms.
4241 This only takes effect if the memory commands are activated
4242 globally (CONFIG_CMD_MEM).
4244 - CONFIG_SKIP_LOWLEVEL_INIT
4245 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4246 low level initializations (like setting up the memory
4247 controller) are omitted and/or U-Boot does not
4248 relocate itself into RAM.
4250 Normally this variable MUST NOT be defined. The only
4251 exception is when U-Boot is loaded (to RAM) by some
4252 other boot loader or by a debugger which performs
4253 these initializations itself.
4256 Modifies the behaviour of start.S when compiling a loader
4257 that is executed before the actual U-Boot. E.g. when
4258 compiling a NAND SPL.
4261 Modifies the behaviour of start.S when compiling a loader
4262 that is executed after the SPL and before the actual U-Boot.
4263 It is loaded by the SPL.
4265 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4266 Only for 85xx systems. If this variable is specified, the section
4267 .resetvec is not kept and the section .bootpg is placed in the
4268 previous 4k of the .text section.
4270 - CONFIG_ARCH_MAP_SYSMEM
4271 Generally U-Boot (and in particular the md command) uses
4272 effective address. It is therefore not necessary to regard
4273 U-Boot address as virtual addresses that need to be translated
4274 to physical addresses. However, sandbox requires this, since
4275 it maintains its own little RAM buffer which contains all
4276 addressable memory. This option causes some memory accesses
4277 to be mapped through map_sysmem() / unmap_sysmem().
4279 - CONFIG_USE_ARCH_MEMCPY
4280 CONFIG_USE_ARCH_MEMSET
4281 If these options are used a optimized version of memcpy/memset will
4282 be used if available. These functions may be faster under some
4283 conditions but may increase the binary size.
4285 - CONFIG_X86_RESET_VECTOR
4286 If defined, the x86 reset vector code is included. This is not
4287 needed when U-Boot is running from Coreboot.
4290 Defines the MPU clock speed (in MHz).
4292 NOTE : currently only supported on AM335x platforms.
4294 Freescale QE/FMAN Firmware Support:
4295 -----------------------------------
4297 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4298 loading of "firmware", which is encoded in the QE firmware binary format.
4299 This firmware often needs to be loaded during U-Boot booting, so macros
4300 are used to identify the storage device (NOR flash, SPI, etc) and the address
4303 - CONFIG_SYS_QE_FMAN_FW_ADDR
4304 The address in the storage device where the firmware is located. The
4305 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4308 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4309 The maximum possible size of the firmware. The firmware binary format
4310 has a field that specifies the actual size of the firmware, but it
4311 might not be possible to read any part of the firmware unless some
4312 local storage is allocated to hold the entire firmware first.
4314 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4315 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4316 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4317 virtual address in NOR flash.
4319 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4320 Specifies that QE/FMAN firmware is located in NAND flash.
4321 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4323 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4324 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4325 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4327 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4328 Specifies that QE/FMAN firmware is located on the primary SPI
4329 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4331 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4332 Specifies that QE/FMAN firmware is located in the remote (master)
4333 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4334 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4335 window->master inbound window->master LAW->the ucode address in
4336 master's memory space.
4338 Building the Software:
4339 ======================
4341 Building U-Boot has been tested in several native build environments
4342 and in many different cross environments. Of course we cannot support
4343 all possibly existing versions of cross development tools in all
4344 (potentially obsolete) versions. In case of tool chain problems we
4345 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4346 which is extensively used to build and test U-Boot.
4348 If you are not using a native environment, it is assumed that you
4349 have GNU cross compiling tools available in your path. In this case,
4350 you must set the environment variable CROSS_COMPILE in your shell.
4351 Note that no changes to the Makefile or any other source files are
4352 necessary. For example using the ELDK on a 4xx CPU, please enter:
4354 $ CROSS_COMPILE=ppc_4xx-
4355 $ export CROSS_COMPILE
4357 Note: If you wish to generate Windows versions of the utilities in
4358 the tools directory you can use the MinGW toolchain
4359 (http://www.mingw.org). Set your HOST tools to the MinGW
4360 toolchain and execute 'make tools'. For example:
4362 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4364 Binaries such as tools/mkimage.exe will be created which can
4365 be executed on computers running Windows.
4367 U-Boot is intended to be simple to build. After installing the
4368 sources you must configure U-Boot for one specific board type. This
4373 where "NAME_config" is the name of one of the existing configu-
4374 rations; see boards.cfg for supported names.
4376 Note: for some board special configuration names may exist; check if
4377 additional information is available from the board vendor; for
4378 instance, the TQM823L systems are available without (standard)
4379 or with LCD support. You can select such additional "features"
4380 when choosing the configuration, i. e.
4383 - will configure for a plain TQM823L, i. e. no LCD support
4385 make TQM823L_LCD_config
4386 - will configure for a TQM823L with U-Boot console on LCD
4391 Finally, type "make all", and you should get some working U-Boot
4392 images ready for download to / installation on your system:
4394 - "u-boot.bin" is a raw binary image
4395 - "u-boot" is an image in ELF binary format
4396 - "u-boot.srec" is in Motorola S-Record format
4398 By default the build is performed locally and the objects are saved
4399 in the source directory. One of the two methods can be used to change
4400 this behavior and build U-Boot to some external directory:
4402 1. Add O= to the make command line invocations:
4404 make O=/tmp/build distclean
4405 make O=/tmp/build NAME_config
4406 make O=/tmp/build all
4408 2. Set environment variable BUILD_DIR to point to the desired location:
4410 export BUILD_DIR=/tmp/build
4415 Note that the command line "O=" setting overrides the BUILD_DIR environment
4419 Please be aware that the Makefiles assume you are using GNU make, so
4420 for instance on NetBSD you might need to use "gmake" instead of
4424 If the system board that you have is not listed, then you will need
4425 to port U-Boot to your hardware platform. To do this, follow these
4428 1. Add a new configuration option for your board to the toplevel
4429 "boards.cfg" file, using the existing entries as examples.
4430 Follow the instructions there to keep the boards in order.
4431 2. Create a new directory to hold your board specific code. Add any
4432 files you need. In your board directory, you will need at least
4433 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4434 3. Create a new configuration file "include/configs/<board>.h" for
4436 3. If you're porting U-Boot to a new CPU, then also create a new
4437 directory to hold your CPU specific code. Add any files you need.
4438 4. Run "make <board>_config" with your new name.
4439 5. Type "make", and you should get a working "u-boot.srec" file
4440 to be installed on your target system.
4441 6. Debug and solve any problems that might arise.
4442 [Of course, this last step is much harder than it sounds.]
4445 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4446 ==============================================================
4448 If you have modified U-Boot sources (for instance added a new board
4449 or support for new devices, a new CPU, etc.) you are expected to
4450 provide feedback to the other developers. The feedback normally takes
4451 the form of a "patch", i. e. a context diff against a certain (latest
4452 official or latest in the git repository) version of U-Boot sources.
4454 But before you submit such a patch, please verify that your modifi-
4455 cation did not break existing code. At least make sure that *ALL* of
4456 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4457 just run the "MAKEALL" script, which will configure and build U-Boot
4458 for ALL supported system. Be warned, this will take a while. You can
4459 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4460 environment variable to the script, i. e. to use the ELDK cross tools
4463 CROSS_COMPILE=ppc_8xx- MAKEALL
4465 or to build on a native PowerPC system you can type
4467 CROSS_COMPILE=' ' MAKEALL
4469 When using the MAKEALL script, the default behaviour is to build
4470 U-Boot in the source directory. This location can be changed by
4471 setting the BUILD_DIR environment variable. Also, for each target
4472 built, the MAKEALL script saves two log files (<target>.ERR and
4473 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4474 location can be changed by setting the MAKEALL_LOGDIR environment
4475 variable. For example:
4477 export BUILD_DIR=/tmp/build
4478 export MAKEALL_LOGDIR=/tmp/log
4479 CROSS_COMPILE=ppc_8xx- MAKEALL
4481 With the above settings build objects are saved in the /tmp/build,
4482 log files are saved in the /tmp/log and the source tree remains clean
4483 during the whole build process.
4486 See also "U-Boot Porting Guide" below.
4489 Monitor Commands - Overview:
4490 ============================
4492 go - start application at address 'addr'
4493 run - run commands in an environment variable
4494 bootm - boot application image from memory
4495 bootp - boot image via network using BootP/TFTP protocol
4496 bootz - boot zImage from memory
4497 tftpboot- boot image via network using TFTP protocol
4498 and env variables "ipaddr" and "serverip"
4499 (and eventually "gatewayip")
4500 tftpput - upload a file via network using TFTP protocol
4501 rarpboot- boot image via network using RARP/TFTP protocol
4502 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4503 loads - load S-Record file over serial line
4504 loadb - load binary file over serial line (kermit mode)
4506 mm - memory modify (auto-incrementing)
4507 nm - memory modify (constant address)
4508 mw - memory write (fill)
4510 cmp - memory compare
4511 crc32 - checksum calculation
4512 i2c - I2C sub-system
4513 sspi - SPI utility commands
4514 base - print or set address offset
4515 printenv- print environment variables
4516 setenv - set environment variables
4517 saveenv - save environment variables to persistent storage
4518 protect - enable or disable FLASH write protection
4519 erase - erase FLASH memory
4520 flinfo - print FLASH memory information
4521 nand - NAND memory operations (see doc/README.nand)
4522 bdinfo - print Board Info structure
4523 iminfo - print header information for application image
4524 coninfo - print console devices and informations
4525 ide - IDE sub-system
4526 loop - infinite loop on address range
4527 loopw - infinite write loop on address range
4528 mtest - simple RAM test
4529 icache - enable or disable instruction cache
4530 dcache - enable or disable data cache
4531 reset - Perform RESET of the CPU
4532 echo - echo args to console
4533 version - print monitor version
4534 help - print online help
4535 ? - alias for 'help'
4538 Monitor Commands - Detailed Description:
4539 ========================================
4543 For now: just type "help <command>".
4546 Environment Variables:
4547 ======================
4549 U-Boot supports user configuration using Environment Variables which
4550 can be made persistent by saving to Flash memory.
4552 Environment Variables are set using "setenv", printed using
4553 "printenv", and saved to Flash using "saveenv". Using "setenv"
4554 without a value can be used to delete a variable from the
4555 environment. As long as you don't save the environment you are
4556 working with an in-memory copy. In case the Flash area containing the
4557 environment is erased by accident, a default environment is provided.
4559 Some configuration options can be set using Environment Variables.
4561 List of environment variables (most likely not complete):
4563 baudrate - see CONFIG_BAUDRATE
4565 bootdelay - see CONFIG_BOOTDELAY
4567 bootcmd - see CONFIG_BOOTCOMMAND
4569 bootargs - Boot arguments when booting an RTOS image
4571 bootfile - Name of the image to load with TFTP
4573 bootm_low - Memory range available for image processing in the bootm
4574 command can be restricted. This variable is given as
4575 a hexadecimal number and defines lowest address allowed
4576 for use by the bootm command. See also "bootm_size"
4577 environment variable. Address defined by "bootm_low" is
4578 also the base of the initial memory mapping for the Linux
4579 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4582 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4583 This variable is given as a hexadecimal number and it
4584 defines the size of the memory region starting at base
4585 address bootm_low that is accessible by the Linux kernel
4586 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4587 as the default value if it is defined, and bootm_size is
4590 bootm_size - Memory range available for image processing in the bootm
4591 command can be restricted. This variable is given as
4592 a hexadecimal number and defines the size of the region
4593 allowed for use by the bootm command. See also "bootm_low"
4594 environment variable.
4596 updatefile - Location of the software update file on a TFTP server, used
4597 by the automatic software update feature. Please refer to
4598 documentation in doc/README.update for more details.
4600 autoload - if set to "no" (any string beginning with 'n'),
4601 "bootp" will just load perform a lookup of the
4602 configuration from the BOOTP server, but not try to
4603 load any image using TFTP
4605 autostart - if set to "yes", an image loaded using the "bootp",
4606 "rarpboot", "tftpboot" or "diskboot" commands will
4607 be automatically started (by internally calling
4610 If set to "no", a standalone image passed to the
4611 "bootm" command will be copied to the load address
4612 (and eventually uncompressed), but NOT be started.
4613 This can be used to load and uncompress arbitrary
4616 fdt_high - if set this restricts the maximum address that the
4617 flattened device tree will be copied into upon boot.
4618 For example, if you have a system with 1 GB memory
4619 at physical address 0x10000000, while Linux kernel
4620 only recognizes the first 704 MB as low memory, you
4621 may need to set fdt_high as 0x3C000000 to have the
4622 device tree blob be copied to the maximum address
4623 of the 704 MB low memory, so that Linux kernel can
4624 access it during the boot procedure.
4626 If this is set to the special value 0xFFFFFFFF then
4627 the fdt will not be copied at all on boot. For this
4628 to work it must reside in writable memory, have
4629 sufficient padding on the end of it for u-boot to
4630 add the information it needs into it, and the memory
4631 must be accessible by the kernel.
4633 fdtcontroladdr- if set this is the address of the control flattened
4634 device tree used by U-Boot when CONFIG_OF_CONTROL is
4637 i2cfast - (PPC405GP|PPC405EP only)
4638 if set to 'y' configures Linux I2C driver for fast
4639 mode (400kHZ). This environment variable is used in
4640 initialization code. So, for changes to be effective
4641 it must be saved and board must be reset.
4643 initrd_high - restrict positioning of initrd images:
4644 If this variable is not set, initrd images will be
4645 copied to the highest possible address in RAM; this
4646 is usually what you want since it allows for
4647 maximum initrd size. If for some reason you want to
4648 make sure that the initrd image is loaded below the
4649 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4650 variable to a value of "no" or "off" or "0".
4651 Alternatively, you can set it to a maximum upper
4652 address to use (U-Boot will still check that it
4653 does not overwrite the U-Boot stack and data).
4655 For instance, when you have a system with 16 MB
4656 RAM, and want to reserve 4 MB from use by Linux,
4657 you can do this by adding "mem=12M" to the value of
4658 the "bootargs" variable. However, now you must make
4659 sure that the initrd image is placed in the first
4660 12 MB as well - this can be done with
4662 setenv initrd_high 00c00000
4664 If you set initrd_high to 0xFFFFFFFF, this is an
4665 indication to U-Boot that all addresses are legal
4666 for the Linux kernel, including addresses in flash
4667 memory. In this case U-Boot will NOT COPY the
4668 ramdisk at all. This may be useful to reduce the
4669 boot time on your system, but requires that this
4670 feature is supported by your Linux kernel.
4672 ipaddr - IP address; needed for tftpboot command
4674 loadaddr - Default load address for commands like "bootp",
4675 "rarpboot", "tftpboot", "loadb" or "diskboot"
4677 loads_echo - see CONFIG_LOADS_ECHO
4679 serverip - TFTP server IP address; needed for tftpboot command
4681 bootretry - see CONFIG_BOOT_RETRY_TIME
4683 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4685 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4687 ethprime - controls which interface is used first.
4689 ethact - controls which interface is currently active.
4690 For example you can do the following
4692 => setenv ethact FEC
4693 => ping 192.168.0.1 # traffic sent on FEC
4694 => setenv ethact SCC
4695 => ping 10.0.0.1 # traffic sent on SCC
4697 ethrotate - When set to "no" U-Boot does not go through all
4698 available network interfaces.
4699 It just stays at the currently selected interface.
4701 netretry - When set to "no" each network operation will
4702 either succeed or fail without retrying.
4703 When set to "once" the network operation will
4704 fail when all the available network interfaces
4705 are tried once without success.
4706 Useful on scripts which control the retry operation
4709 npe_ucode - set load address for the NPE microcode
4711 silent_linux - If set then linux will be told to boot silently, by
4712 changing the console to be empty. If "yes" it will be
4713 made silent. If "no" it will not be made silent. If
4714 unset, then it will be made silent if the U-Boot console
4717 tftpsrcport - If this is set, the value is used for TFTP's
4720 tftpdstport - If this is set, the value is used for TFTP's UDP
4721 destination port instead of the Well Know Port 69.
4723 tftpblocksize - Block size to use for TFTP transfers; if not set,
4724 we use the TFTP server's default block size
4726 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4727 seconds, minimum value is 1000 = 1 second). Defines
4728 when a packet is considered to be lost so it has to
4729 be retransmitted. The default is 5000 = 5 seconds.
4730 Lowering this value may make downloads succeed
4731 faster in networks with high packet loss rates or
4732 with unreliable TFTP servers.
4734 vlan - When set to a value < 4095 the traffic over
4735 Ethernet is encapsulated/received over 802.1q
4738 The following image location variables contain the location of images
4739 used in booting. The "Image" column gives the role of the image and is
4740 not an environment variable name. The other columns are environment
4741 variable names. "File Name" gives the name of the file on a TFTP
4742 server, "RAM Address" gives the location in RAM the image will be
4743 loaded to, and "Flash Location" gives the image's address in NOR
4744 flash or offset in NAND flash.
4746 *Note* - these variables don't have to be defined for all boards, some
4747 boards currenlty use other variables for these purposes, and some
4748 boards use these variables for other purposes.
4750 Image File Name RAM Address Flash Location
4751 ----- --------- ----------- --------------
4752 u-boot u-boot u-boot_addr_r u-boot_addr
4753 Linux kernel bootfile kernel_addr_r kernel_addr
4754 device tree blob fdtfile fdt_addr_r fdt_addr
4755 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4757 The following environment variables may be used and automatically
4758 updated by the network boot commands ("bootp" and "rarpboot"),
4759 depending the information provided by your boot server:
4761 bootfile - see above
4762 dnsip - IP address of your Domain Name Server
4763 dnsip2 - IP address of your secondary Domain Name Server
4764 gatewayip - IP address of the Gateway (Router) to use
4765 hostname - Target hostname
4767 netmask - Subnet Mask
4768 rootpath - Pathname of the root filesystem on the NFS server
4769 serverip - see above
4772 There are two special Environment Variables:
4774 serial# - contains hardware identification information such
4775 as type string and/or serial number
4776 ethaddr - Ethernet address
4778 These variables can be set only once (usually during manufacturing of
4779 the board). U-Boot refuses to delete or overwrite these variables
4780 once they have been set once.
4783 Further special Environment Variables:
4785 ver - Contains the U-Boot version string as printed
4786 with the "version" command. This variable is
4787 readonly (see CONFIG_VERSION_VARIABLE).
4790 Please note that changes to some configuration parameters may take
4791 only effect after the next boot (yes, that's just like Windoze :-).
4794 Callback functions for environment variables:
4795 ---------------------------------------------
4797 For some environment variables, the behavior of u-boot needs to change
4798 when their values are changed. This functionailty allows functions to
4799 be associated with arbitrary variables. On creation, overwrite, or
4800 deletion, the callback will provide the opportunity for some side
4801 effect to happen or for the change to be rejected.
4803 The callbacks are named and associated with a function using the
4804 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4806 These callbacks are associated with variables in one of two ways. The
4807 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4808 in the board configuration to a string that defines a list of
4809 associations. The list must be in the following format:
4811 entry = variable_name[:callback_name]
4814 If the callback name is not specified, then the callback is deleted.
4815 Spaces are also allowed anywhere in the list.
4817 Callbacks can also be associated by defining the ".callbacks" variable
4818 with the same list format above. Any association in ".callbacks" will
4819 override any association in the static list. You can define
4820 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4821 ".callbacks" envirnoment variable in the default or embedded environment.
4824 Command Line Parsing:
4825 =====================
4827 There are two different command line parsers available with U-Boot:
4828 the old "simple" one, and the much more powerful "hush" shell:
4830 Old, simple command line parser:
4831 --------------------------------
4833 - supports environment variables (through setenv / saveenv commands)
4834 - several commands on one line, separated by ';'
4835 - variable substitution using "... ${name} ..." syntax
4836 - special characters ('$', ';') can be escaped by prefixing with '\',
4838 setenv bootcmd bootm \${address}
4839 - You can also escape text by enclosing in single apostrophes, for example:
4840 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4845 - similar to Bourne shell, with control structures like
4846 if...then...else...fi, for...do...done; while...do...done,
4847 until...do...done, ...
4848 - supports environment ("global") variables (through setenv / saveenv
4849 commands) and local shell variables (through standard shell syntax
4850 "name=value"); only environment variables can be used with "run"
4856 (1) If a command line (or an environment variable executed by a "run"
4857 command) contains several commands separated by semicolon, and
4858 one of these commands fails, then the remaining commands will be
4861 (2) If you execute several variables with one call to run (i. e.
4862 calling run with a list of variables as arguments), any failing
4863 command will cause "run" to terminate, i. e. the remaining
4864 variables are not executed.
4866 Note for Redundant Ethernet Interfaces:
4867 =======================================
4869 Some boards come with redundant Ethernet interfaces; U-Boot supports
4870 such configurations and is capable of automatic selection of a
4871 "working" interface when needed. MAC assignment works as follows:
4873 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4874 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4875 "eth1addr" (=>eth1), "eth2addr", ...
4877 If the network interface stores some valid MAC address (for instance
4878 in SROM), this is used as default address if there is NO correspon-
4879 ding setting in the environment; if the corresponding environment
4880 variable is set, this overrides the settings in the card; that means:
4882 o If the SROM has a valid MAC address, and there is no address in the
4883 environment, the SROM's address is used.
4885 o If there is no valid address in the SROM, and a definition in the
4886 environment exists, then the value from the environment variable is
4889 o If both the SROM and the environment contain a MAC address, and
4890 both addresses are the same, this MAC address is used.
4892 o If both the SROM and the environment contain a MAC address, and the
4893 addresses differ, the value from the environment is used and a
4896 o If neither SROM nor the environment contain a MAC address, an error
4899 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4900 will be programmed into hardware as part of the initialization process. This
4901 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4902 The naming convention is as follows:
4903 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4908 U-Boot is capable of booting (and performing other auxiliary operations on)
4909 images in two formats:
4911 New uImage format (FIT)
4912 -----------------------
4914 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4915 to Flattened Device Tree). It allows the use of images with multiple
4916 components (several kernels, ramdisks, etc.), with contents protected by
4917 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4923 Old image format is based on binary files which can be basically anything,
4924 preceded by a special header; see the definitions in include/image.h for
4925 details; basically, the header defines the following image properties:
4927 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4928 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4929 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4930 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4932 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4933 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4934 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4935 * Compression Type (uncompressed, gzip, bzip2)
4941 The header is marked by a special Magic Number, and both the header
4942 and the data portions of the image are secured against corruption by
4949 Although U-Boot should support any OS or standalone application
4950 easily, the main focus has always been on Linux during the design of
4953 U-Boot includes many features that so far have been part of some
4954 special "boot loader" code within the Linux kernel. Also, any
4955 "initrd" images to be used are no longer part of one big Linux image;
4956 instead, kernel and "initrd" are separate images. This implementation
4957 serves several purposes:
4959 - the same features can be used for other OS or standalone
4960 applications (for instance: using compressed images to reduce the
4961 Flash memory footprint)
4963 - it becomes much easier to port new Linux kernel versions because
4964 lots of low-level, hardware dependent stuff are done by U-Boot
4966 - the same Linux kernel image can now be used with different "initrd"
4967 images; of course this also means that different kernel images can
4968 be run with the same "initrd". This makes testing easier (you don't
4969 have to build a new "zImage.initrd" Linux image when you just
4970 change a file in your "initrd"). Also, a field-upgrade of the
4971 software is easier now.
4977 Porting Linux to U-Boot based systems:
4978 ---------------------------------------
4980 U-Boot cannot save you from doing all the necessary modifications to
4981 configure the Linux device drivers for use with your target hardware
4982 (no, we don't intend to provide a full virtual machine interface to
4985 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4987 Just make sure your machine specific header file (for instance
4988 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4989 Information structure as we define in include/asm-<arch>/u-boot.h,
4990 and make sure that your definition of IMAP_ADDR uses the same value
4991 as your U-Boot configuration in CONFIG_SYS_IMMR.
4994 Configuring the Linux kernel:
4995 -----------------------------
4997 No specific requirements for U-Boot. Make sure you have some root
4998 device (initial ramdisk, NFS) for your target system.
5001 Building a Linux Image:
5002 -----------------------
5004 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5005 not used. If you use recent kernel source, a new build target
5006 "uImage" will exist which automatically builds an image usable by
5007 U-Boot. Most older kernels also have support for a "pImage" target,
5008 which was introduced for our predecessor project PPCBoot and uses a
5009 100% compatible format.
5018 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5019 encapsulate a compressed Linux kernel image with header information,
5020 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5022 * build a standard "vmlinux" kernel image (in ELF binary format):
5024 * convert the kernel into a raw binary image:
5026 ${CROSS_COMPILE}-objcopy -O binary \
5027 -R .note -R .comment \
5028 -S vmlinux linux.bin
5030 * compress the binary image:
5034 * package compressed binary image for U-Boot:
5036 mkimage -A ppc -O linux -T kernel -C gzip \
5037 -a 0 -e 0 -n "Linux Kernel Image" \
5038 -d linux.bin.gz uImage
5041 The "mkimage" tool can also be used to create ramdisk images for use
5042 with U-Boot, either separated from the Linux kernel image, or
5043 combined into one file. "mkimage" encapsulates the images with a 64
5044 byte header containing information about target architecture,
5045 operating system, image type, compression method, entry points, time
5046 stamp, CRC32 checksums, etc.
5048 "mkimage" can be called in two ways: to verify existing images and
5049 print the header information, or to build new images.
5051 In the first form (with "-l" option) mkimage lists the information
5052 contained in the header of an existing U-Boot image; this includes
5053 checksum verification:
5055 tools/mkimage -l image
5056 -l ==> list image header information
5058 The second form (with "-d" option) is used to build a U-Boot image
5059 from a "data file" which is used as image payload:
5061 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5062 -n name -d data_file image
5063 -A ==> set architecture to 'arch'
5064 -O ==> set operating system to 'os'
5065 -T ==> set image type to 'type'
5066 -C ==> set compression type 'comp'
5067 -a ==> set load address to 'addr' (hex)
5068 -e ==> set entry point to 'ep' (hex)
5069 -n ==> set image name to 'name'
5070 -d ==> use image data from 'datafile'
5072 Right now, all Linux kernels for PowerPC systems use the same load
5073 address (0x00000000), but the entry point address depends on the
5076 - 2.2.x kernels have the entry point at 0x0000000C,
5077 - 2.3.x and later kernels have the entry point at 0x00000000.
5079 So a typical call to build a U-Boot image would read:
5081 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5082 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5083 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5084 > examples/uImage.TQM850L
5085 Image Name: 2.4.4 kernel for TQM850L
5086 Created: Wed Jul 19 02:34:59 2000
5087 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5088 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5089 Load Address: 0x00000000
5090 Entry Point: 0x00000000
5092 To verify the contents of the image (or check for corruption):
5094 -> tools/mkimage -l examples/uImage.TQM850L
5095 Image Name: 2.4.4 kernel for TQM850L
5096 Created: Wed Jul 19 02:34:59 2000
5097 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5098 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5099 Load Address: 0x00000000
5100 Entry Point: 0x00000000
5102 NOTE: for embedded systems where boot time is critical you can trade
5103 speed for memory and install an UNCOMPRESSED image instead: this
5104 needs more space in Flash, but boots much faster since it does not
5105 need to be uncompressed:
5107 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5108 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5109 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5110 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5111 > examples/uImage.TQM850L-uncompressed
5112 Image Name: 2.4.4 kernel for TQM850L
5113 Created: Wed Jul 19 02:34:59 2000
5114 Image Type: PowerPC Linux Kernel Image (uncompressed)
5115 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5116 Load Address: 0x00000000
5117 Entry Point: 0x00000000
5120 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5121 when your kernel is intended to use an initial ramdisk:
5123 -> tools/mkimage -n 'Simple Ramdisk Image' \
5124 > -A ppc -O linux -T ramdisk -C gzip \
5125 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5126 Image Name: Simple Ramdisk Image
5127 Created: Wed Jan 12 14:01:50 2000
5128 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5129 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5130 Load Address: 0x00000000
5131 Entry Point: 0x00000000
5134 Installing a Linux Image:
5135 -------------------------
5137 To downloading a U-Boot image over the serial (console) interface,
5138 you must convert the image to S-Record format:
5140 objcopy -I binary -O srec examples/image examples/image.srec
5142 The 'objcopy' does not understand the information in the U-Boot
5143 image header, so the resulting S-Record file will be relative to
5144 address 0x00000000. To load it to a given address, you need to
5145 specify the target address as 'offset' parameter with the 'loads'
5148 Example: install the image to address 0x40100000 (which on the
5149 TQM8xxL is in the first Flash bank):
5151 => erase 40100000 401FFFFF
5157 ## Ready for S-Record download ...
5158 ~>examples/image.srec
5159 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5161 15989 15990 15991 15992
5162 [file transfer complete]
5164 ## Start Addr = 0x00000000
5167 You can check the success of the download using the 'iminfo' command;
5168 this includes a checksum verification so you can be sure no data
5169 corruption happened:
5173 ## Checking Image at 40100000 ...
5174 Image Name: 2.2.13 for initrd on TQM850L
5175 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5176 Data Size: 335725 Bytes = 327 kB = 0 MB
5177 Load Address: 00000000
5178 Entry Point: 0000000c
5179 Verifying Checksum ... OK
5185 The "bootm" command is used to boot an application that is stored in
5186 memory (RAM or Flash). In case of a Linux kernel image, the contents
5187 of the "bootargs" environment variable is passed to the kernel as
5188 parameters. You can check and modify this variable using the
5189 "printenv" and "setenv" commands:
5192 => printenv bootargs
5193 bootargs=root=/dev/ram
5195 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5197 => printenv bootargs
5198 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5201 ## Booting Linux kernel at 40020000 ...
5202 Image Name: 2.2.13 for NFS on TQM850L
5203 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5204 Data Size: 381681 Bytes = 372 kB = 0 MB
5205 Load Address: 00000000
5206 Entry Point: 0000000c
5207 Verifying Checksum ... OK
5208 Uncompressing Kernel Image ... OK
5209 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
5210 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5211 time_init: decrementer frequency = 187500000/60
5212 Calibrating delay loop... 49.77 BogoMIPS
5213 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5216 If you want to boot a Linux kernel with initial RAM disk, you pass
5217 the memory addresses of both the kernel and the initrd image (PPBCOOT
5218 format!) to the "bootm" command:
5220 => imi 40100000 40200000
5222 ## Checking Image at 40100000 ...
5223 Image Name: 2.2.13 for initrd on TQM850L
5224 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5225 Data Size: 335725 Bytes = 327 kB = 0 MB
5226 Load Address: 00000000
5227 Entry Point: 0000000c
5228 Verifying Checksum ... OK
5230 ## Checking Image at 40200000 ...
5231 Image Name: Simple Ramdisk Image
5232 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5233 Data Size: 566530 Bytes = 553 kB = 0 MB
5234 Load Address: 00000000
5235 Entry Point: 00000000
5236 Verifying Checksum ... OK
5238 => bootm 40100000 40200000
5239 ## Booting Linux kernel at 40100000 ...
5240 Image Name: 2.2.13 for initrd on TQM850L
5241 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5242 Data Size: 335725 Bytes = 327 kB = 0 MB
5243 Load Address: 00000000
5244 Entry Point: 0000000c
5245 Verifying Checksum ... OK
5246 Uncompressing Kernel Image ... OK
5247 ## Loading RAMDisk Image at 40200000 ...
5248 Image Name: Simple Ramdisk Image
5249 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5250 Data Size: 566530 Bytes = 553 kB = 0 MB
5251 Load Address: 00000000
5252 Entry Point: 00000000
5253 Verifying Checksum ... OK
5254 Loading Ramdisk ... OK
5255 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
5256 Boot arguments: root=/dev/ram
5257 time_init: decrementer frequency = 187500000/60
5258 Calibrating delay loop... 49.77 BogoMIPS
5260 RAMDISK: Compressed image found at block 0
5261 VFS: Mounted root (ext2 filesystem).
5265 Boot Linux and pass a flat device tree:
5268 First, U-Boot must be compiled with the appropriate defines. See the section
5269 titled "Linux Kernel Interface" above for a more in depth explanation. The
5270 following is an example of how to start a kernel and pass an updated
5276 oft=oftrees/mpc8540ads.dtb
5277 => tftp $oftaddr $oft
5278 Speed: 1000, full duplex
5280 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5281 Filename 'oftrees/mpc8540ads.dtb'.
5282 Load address: 0x300000
5285 Bytes transferred = 4106 (100a hex)
5286 => tftp $loadaddr $bootfile
5287 Speed: 1000, full duplex
5289 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5291 Load address: 0x200000
5292 Loading:############
5294 Bytes transferred = 1029407 (fb51f hex)
5299 => bootm $loadaddr - $oftaddr
5300 ## Booting image at 00200000 ...
5301 Image Name: Linux-2.6.17-dirty
5302 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5303 Data Size: 1029343 Bytes = 1005.2 kB
5304 Load Address: 00000000
5305 Entry Point: 00000000
5306 Verifying Checksum ... OK
5307 Uncompressing Kernel Image ... OK
5308 Booting using flat device tree at 0x300000
5309 Using MPC85xx ADS machine description
5310 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5314 More About U-Boot Image Types:
5315 ------------------------------
5317 U-Boot supports the following image types:
5319 "Standalone Programs" are directly runnable in the environment
5320 provided by U-Boot; it is expected that (if they behave
5321 well) you can continue to work in U-Boot after return from
5322 the Standalone Program.
5323 "OS Kernel Images" are usually images of some Embedded OS which
5324 will take over control completely. Usually these programs
5325 will install their own set of exception handlers, device
5326 drivers, set up the MMU, etc. - this means, that you cannot
5327 expect to re-enter U-Boot except by resetting the CPU.
5328 "RAMDisk Images" are more or less just data blocks, and their
5329 parameters (address, size) are passed to an OS kernel that is
5331 "Multi-File Images" contain several images, typically an OS
5332 (Linux) kernel image and one or more data images like
5333 RAMDisks. This construct is useful for instance when you want
5334 to boot over the network using BOOTP etc., where the boot
5335 server provides just a single image file, but you want to get
5336 for instance an OS kernel and a RAMDisk image.
5338 "Multi-File Images" start with a list of image sizes, each
5339 image size (in bytes) specified by an "uint32_t" in network
5340 byte order. This list is terminated by an "(uint32_t)0".
5341 Immediately after the terminating 0 follow the images, one by
5342 one, all aligned on "uint32_t" boundaries (size rounded up to
5343 a multiple of 4 bytes).
5345 "Firmware Images" are binary images containing firmware (like
5346 U-Boot or FPGA images) which usually will be programmed to
5349 "Script files" are command sequences that will be executed by
5350 U-Boot's command interpreter; this feature is especially
5351 useful when you configure U-Boot to use a real shell (hush)
5352 as command interpreter.
5354 Booting the Linux zImage:
5355 -------------------------
5357 On some platforms, it's possible to boot Linux zImage. This is done
5358 using the "bootz" command. The syntax of "bootz" command is the same
5359 as the syntax of "bootm" command.
5361 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5362 kernel with raw initrd images. The syntax is slightly different, the
5363 address of the initrd must be augmented by it's size, in the following
5364 format: "<initrd addres>:<initrd size>".
5370 One of the features of U-Boot is that you can dynamically load and
5371 run "standalone" applications, which can use some resources of
5372 U-Boot like console I/O functions or interrupt services.
5374 Two simple examples are included with the sources:
5379 'examples/hello_world.c' contains a small "Hello World" Demo
5380 application; it is automatically compiled when you build U-Boot.
5381 It's configured to run at address 0x00040004, so you can play with it
5385 ## Ready for S-Record download ...
5386 ~>examples/hello_world.srec
5387 1 2 3 4 5 6 7 8 9 10 11 ...
5388 [file transfer complete]
5390 ## Start Addr = 0x00040004
5392 => go 40004 Hello World! This is a test.
5393 ## Starting application at 0x00040004 ...
5404 Hit any key to exit ...
5406 ## Application terminated, rc = 0x0
5408 Another example, which demonstrates how to register a CPM interrupt
5409 handler with the U-Boot code, can be found in 'examples/timer.c'.
5410 Here, a CPM timer is set up to generate an interrupt every second.
5411 The interrupt service routine is trivial, just printing a '.'
5412 character, but this is just a demo program. The application can be
5413 controlled by the following keys:
5415 ? - print current values og the CPM Timer registers
5416 b - enable interrupts and start timer
5417 e - stop timer and disable interrupts
5418 q - quit application
5421 ## Ready for S-Record download ...
5422 ~>examples/timer.srec
5423 1 2 3 4 5 6 7 8 9 10 11 ...
5424 [file transfer complete]
5426 ## Start Addr = 0x00040004
5429 ## Starting application at 0x00040004 ...
5432 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5435 [q, b, e, ?] Set interval 1000000 us
5438 [q, b, e, ?] ........
5439 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5442 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5445 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5448 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5450 [q, b, e, ?] ...Stopping timer
5452 [q, b, e, ?] ## Application terminated, rc = 0x0
5458 Over time, many people have reported problems when trying to use the
5459 "minicom" terminal emulation program for serial download. I (wd)
5460 consider minicom to be broken, and recommend not to use it. Under
5461 Unix, I recommend to use C-Kermit for general purpose use (and
5462 especially for kermit binary protocol download ("loadb" command), and
5463 use "cu" for S-Record download ("loads" command). See
5464 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5465 for help with kermit.
5468 Nevertheless, if you absolutely want to use it try adding this
5469 configuration to your "File transfer protocols" section:
5471 Name Program Name U/D FullScr IO-Red. Multi
5472 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5473 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5479 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5480 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5482 Building requires a cross environment; it is known to work on
5483 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5484 need gmake since the Makefiles are not compatible with BSD make).
5485 Note that the cross-powerpc package does not install include files;
5486 attempting to build U-Boot will fail because <machine/ansi.h> is
5487 missing. This file has to be installed and patched manually:
5489 # cd /usr/pkg/cross/powerpc-netbsd/include
5491 # ln -s powerpc machine
5492 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5493 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5495 Native builds *don't* work due to incompatibilities between native
5496 and U-Boot include files.
5498 Booting assumes that (the first part of) the image booted is a
5499 stage-2 loader which in turn loads and then invokes the kernel
5500 proper. Loader sources will eventually appear in the NetBSD source
5501 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5502 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5505 Implementation Internals:
5506 =========================
5508 The following is not intended to be a complete description of every
5509 implementation detail. However, it should help to understand the
5510 inner workings of U-Boot and make it easier to port it to custom
5514 Initial Stack, Global Data:
5515 ---------------------------
5517 The implementation of U-Boot is complicated by the fact that U-Boot
5518 starts running out of ROM (flash memory), usually without access to
5519 system RAM (because the memory controller is not initialized yet).
5520 This means that we don't have writable Data or BSS segments, and BSS
5521 is not initialized as zero. To be able to get a C environment working
5522 at all, we have to allocate at least a minimal stack. Implementation
5523 options for this are defined and restricted by the CPU used: Some CPU
5524 models provide on-chip memory (like the IMMR area on MPC8xx and
5525 MPC826x processors), on others (parts of) the data cache can be
5526 locked as (mis-) used as memory, etc.
5528 Chris Hallinan posted a good summary of these issues to the
5529 U-Boot mailing list:
5531 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5532 From: "Chris Hallinan" <clh@net1plus.com>
5533 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5536 Correct me if I'm wrong, folks, but the way I understand it
5537 is this: Using DCACHE as initial RAM for Stack, etc, does not
5538 require any physical RAM backing up the cache. The cleverness
5539 is that the cache is being used as a temporary supply of
5540 necessary storage before the SDRAM controller is setup. It's
5541 beyond the scope of this list to explain the details, but you
5542 can see how this works by studying the cache architecture and
5543 operation in the architecture and processor-specific manuals.
5545 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5546 is another option for the system designer to use as an
5547 initial stack/RAM area prior to SDRAM being available. Either
5548 option should work for you. Using CS 4 should be fine if your
5549 board designers haven't used it for something that would
5550 cause you grief during the initial boot! It is frequently not
5553 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5554 with your processor/board/system design. The default value
5555 you will find in any recent u-boot distribution in
5556 walnut.h should work for you. I'd set it to a value larger
5557 than your SDRAM module. If you have a 64MB SDRAM module, set
5558 it above 400_0000. Just make sure your board has no resources
5559 that are supposed to respond to that address! That code in
5560 start.S has been around a while and should work as is when
5561 you get the config right.
5566 It is essential to remember this, since it has some impact on the C
5567 code for the initialization procedures:
5569 * Initialized global data (data segment) is read-only. Do not attempt
5572 * Do not use any uninitialized global data (or implicitely initialized
5573 as zero data - BSS segment) at all - this is undefined, initiali-
5574 zation is performed later (when relocating to RAM).
5576 * Stack space is very limited. Avoid big data buffers or things like
5579 Having only the stack as writable memory limits means we cannot use
5580 normal global data to share information beween the code. But it
5581 turned out that the implementation of U-Boot can be greatly
5582 simplified by making a global data structure (gd_t) available to all
5583 functions. We could pass a pointer to this data as argument to _all_
5584 functions, but this would bloat the code. Instead we use a feature of
5585 the GCC compiler (Global Register Variables) to share the data: we
5586 place a pointer (gd) to the global data into a register which we
5587 reserve for this purpose.
5589 When choosing a register for such a purpose we are restricted by the
5590 relevant (E)ABI specifications for the current architecture, and by
5591 GCC's implementation.
5593 For PowerPC, the following registers have specific use:
5595 R2: reserved for system use
5596 R3-R4: parameter passing and return values
5597 R5-R10: parameter passing
5598 R13: small data area pointer
5602 (U-Boot also uses R12 as internal GOT pointer. r12
5603 is a volatile register so r12 needs to be reset when
5604 going back and forth between asm and C)
5606 ==> U-Boot will use R2 to hold a pointer to the global data
5608 Note: on PPC, we could use a static initializer (since the
5609 address of the global data structure is known at compile time),
5610 but it turned out that reserving a register results in somewhat
5611 smaller code - although the code savings are not that big (on
5612 average for all boards 752 bytes for the whole U-Boot image,
5613 624 text + 127 data).
5615 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5616 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5618 ==> U-Boot will use P3 to hold a pointer to the global data
5620 On ARM, the following registers are used:
5622 R0: function argument word/integer result
5623 R1-R3: function argument word
5624 R9: platform specific
5625 R10: stack limit (used only if stack checking is enabled)
5626 R11: argument (frame) pointer
5627 R12: temporary workspace
5630 R15: program counter
5632 ==> U-Boot will use R9 to hold a pointer to the global data
5634 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5636 On Nios II, the ABI is documented here:
5637 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5639 ==> U-Boot will use gp to hold a pointer to the global data
5641 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5642 to access small data sections, so gp is free.
5644 On NDS32, the following registers are used:
5646 R0-R1: argument/return
5648 R15: temporary register for assembler
5649 R16: trampoline register
5650 R28: frame pointer (FP)
5651 R29: global pointer (GP)
5652 R30: link register (LP)
5653 R31: stack pointer (SP)
5654 PC: program counter (PC)
5656 ==> U-Boot will use R10 to hold a pointer to the global data
5658 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5659 or current versions of GCC may "optimize" the code too much.
5664 U-Boot runs in system state and uses physical addresses, i.e. the
5665 MMU is not used either for address mapping nor for memory protection.
5667 The available memory is mapped to fixed addresses using the memory
5668 controller. In this process, a contiguous block is formed for each
5669 memory type (Flash, SDRAM, SRAM), even when it consists of several
5670 physical memory banks.
5672 U-Boot is installed in the first 128 kB of the first Flash bank (on
5673 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5674 booting and sizing and initializing DRAM, the code relocates itself
5675 to the upper end of DRAM. Immediately below the U-Boot code some
5676 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5677 configuration setting]. Below that, a structure with global Board
5678 Info data is placed, followed by the stack (growing downward).
5680 Additionally, some exception handler code is copied to the low 8 kB
5681 of DRAM (0x00000000 ... 0x00001FFF).
5683 So a typical memory configuration with 16 MB of DRAM could look like
5686 0x0000 0000 Exception Vector code
5689 0x0000 2000 Free for Application Use
5695 0x00FB FF20 Monitor Stack (Growing downward)
5696 0x00FB FFAC Board Info Data and permanent copy of global data
5697 0x00FC 0000 Malloc Arena
5700 0x00FE 0000 RAM Copy of Monitor Code
5701 ... eventually: LCD or video framebuffer
5702 ... eventually: pRAM (Protected RAM - unchanged by reset)
5703 0x00FF FFFF [End of RAM]
5706 System Initialization:
5707 ----------------------
5709 In the reset configuration, U-Boot starts at the reset entry point
5710 (on most PowerPC systems at address 0x00000100). Because of the reset
5711 configuration for CS0# this is a mirror of the onboard Flash memory.
5712 To be able to re-map memory U-Boot then jumps to its link address.
5713 To be able to implement the initialization code in C, a (small!)
5714 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5715 which provide such a feature like MPC8xx or MPC8260), or in a locked
5716 part of the data cache. After that, U-Boot initializes the CPU core,
5717 the caches and the SIU.
5719 Next, all (potentially) available memory banks are mapped using a
5720 preliminary mapping. For example, we put them on 512 MB boundaries
5721 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5722 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5723 programmed for SDRAM access. Using the temporary configuration, a
5724 simple memory test is run that determines the size of the SDRAM
5727 When there is more than one SDRAM bank, and the banks are of
5728 different size, the largest is mapped first. For equal size, the first
5729 bank (CS2#) is mapped first. The first mapping is always for address
5730 0x00000000, with any additional banks following immediately to create
5731 contiguous memory starting from 0.
5733 Then, the monitor installs itself at the upper end of the SDRAM area
5734 and allocates memory for use by malloc() and for the global Board
5735 Info data; also, the exception vector code is copied to the low RAM
5736 pages, and the final stack is set up.
5738 Only after this relocation will you have a "normal" C environment;
5739 until that you are restricted in several ways, mostly because you are
5740 running from ROM, and because the code will have to be relocated to a
5744 U-Boot Porting Guide:
5745 ----------------------
5747 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5751 int main(int argc, char *argv[])
5753 sighandler_t no_more_time;
5755 signal(SIGALRM, no_more_time);
5756 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5758 if (available_money > available_manpower) {
5759 Pay consultant to port U-Boot;
5763 Download latest U-Boot source;
5765 Subscribe to u-boot mailing list;
5768 email("Hi, I am new to U-Boot, how do I get started?");
5771 Read the README file in the top level directory;
5772 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5773 Read applicable doc/*.README;
5774 Read the source, Luke;
5775 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5778 if (available_money > toLocalCurrency ($2500))
5781 Add a lot of aggravation and time;
5783 if (a similar board exists) { /* hopefully... */
5784 cp -a board/<similar> board/<myboard>
5785 cp include/configs/<similar>.h include/configs/<myboard>.h
5787 Create your own board support subdirectory;
5788 Create your own board include/configs/<myboard>.h file;
5790 Edit new board/<myboard> files
5791 Edit new include/configs/<myboard>.h
5796 Add / modify source code;
5800 email("Hi, I am having problems...");
5802 Send patch file to the U-Boot email list;
5803 if (reasonable critiques)
5804 Incorporate improvements from email list code review;
5806 Defend code as written;
5812 void no_more_time (int sig)
5821 All contributions to U-Boot should conform to the Linux kernel
5822 coding style; see the file "Documentation/CodingStyle" and the script
5823 "scripts/Lindent" in your Linux kernel source directory.
5825 Source files originating from a different project (for example the
5826 MTD subsystem) are generally exempt from these guidelines and are not
5827 reformated to ease subsequent migration to newer versions of those
5830 Please note that U-Boot is implemented in C (and to some small parts in
5831 Assembler); no C++ is used, so please do not use C++ style comments (//)
5834 Please also stick to the following formatting rules:
5835 - remove any trailing white space
5836 - use TAB characters for indentation and vertical alignment, not spaces
5837 - make sure NOT to use DOS '\r\n' line feeds
5838 - do not add more than 2 consecutive empty lines to source files
5839 - do not add trailing empty lines to source files
5841 Submissions which do not conform to the standards may be returned
5842 with a request to reformat the changes.
5848 Since the number of patches for U-Boot is growing, we need to
5849 establish some rules. Submissions which do not conform to these rules
5850 may be rejected, even when they contain important and valuable stuff.
5852 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5854 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5855 see http://lists.denx.de/mailman/listinfo/u-boot
5857 When you send a patch, please include the following information with
5860 * For bug fixes: a description of the bug and how your patch fixes
5861 this bug. Please try to include a way of demonstrating that the
5862 patch actually fixes something.
5864 * For new features: a description of the feature and your
5867 * A CHANGELOG entry as plaintext (separate from the patch)
5869 * For major contributions, your entry to the CREDITS file
5871 * When you add support for a new board, don't forget to add a
5872 maintainer e-mail address to the boards.cfg file, too.
5874 * If your patch adds new configuration options, don't forget to
5875 document these in the README file.
5877 * The patch itself. If you are using git (which is *strongly*
5878 recommended) you can easily generate the patch using the
5879 "git format-patch". If you then use "git send-email" to send it to
5880 the U-Boot mailing list, you will avoid most of the common problems
5881 with some other mail clients.
5883 If you cannot use git, use "diff -purN OLD NEW". If your version of
5884 diff does not support these options, then get the latest version of
5887 The current directory when running this command shall be the parent
5888 directory of the U-Boot source tree (i. e. please make sure that
5889 your patch includes sufficient directory information for the
5892 We prefer patches as plain text. MIME attachments are discouraged,
5893 and compressed attachments must not be used.
5895 * If one logical set of modifications affects or creates several
5896 files, all these changes shall be submitted in a SINGLE patch file.
5898 * Changesets that contain different, unrelated modifications shall be
5899 submitted as SEPARATE patches, one patch per changeset.
5904 * Before sending the patch, run the MAKEALL script on your patched
5905 source tree and make sure that no errors or warnings are reported
5906 for any of the boards.
5908 * Keep your modifications to the necessary minimum: A patch
5909 containing several unrelated changes or arbitrary reformats will be
5910 returned with a request to re-formatting / split it.
5912 * If you modify existing code, make sure that your new code does not
5913 add to the memory footprint of the code ;-) Small is beautiful!
5914 When adding new features, these should compile conditionally only
5915 (using #ifdef), and the resulting code with the new feature
5916 disabled must not need more memory than the old code without your
5919 * Remember that there is a size limit of 100 kB per message on the
5920 u-boot mailing list. Bigger patches will be moderated. If they are
5921 reasonable and not too big, they will be acknowledged. But patches
5922 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob