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.
708 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
710 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
714 CONFIG_BAUDRATE - in bps
715 Select one of the baudrates listed in
716 CONFIG_SYS_BAUDRATE_TABLE, see below.
717 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
719 - Console Rx buffer length
720 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
721 the maximum receive buffer length for the SMC.
722 This option is actual only for 82xx and 8xx possible.
723 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
724 must be defined, to setup the maximum idle timeout for
727 - Pre-Console Buffer:
728 Prior to the console being initialised (i.e. serial UART
729 initialised etc) all console output is silently discarded.
730 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
731 buffer any console messages prior to the console being
732 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
733 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
734 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
735 bytes are output before the console is initialised, the
736 earlier bytes are discarded.
738 'Sane' compilers will generate smaller code if
739 CONFIG_PRE_CON_BUF_SZ is a power of 2
741 - Safe printf() functions
742 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
743 the printf() functions. These are defined in
744 include/vsprintf.h and include snprintf(), vsnprintf() and
745 so on. Code size increase is approximately 300-500 bytes.
746 If this option is not given then these functions will
747 silently discard their buffer size argument - this means
748 you are not getting any overflow checking in this case.
750 - Boot Delay: CONFIG_BOOTDELAY - in seconds
751 Delay before automatically booting the default image;
752 set to -1 to disable autoboot.
753 set to -2 to autoboot with no delay and not check for abort
754 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
756 See doc/README.autoboot for these options that
757 work with CONFIG_BOOTDELAY. None are required.
758 CONFIG_BOOT_RETRY_TIME
759 CONFIG_BOOT_RETRY_MIN
760 CONFIG_AUTOBOOT_KEYED
761 CONFIG_AUTOBOOT_PROMPT
762 CONFIG_AUTOBOOT_DELAY_STR
763 CONFIG_AUTOBOOT_STOP_STR
764 CONFIG_AUTOBOOT_DELAY_STR2
765 CONFIG_AUTOBOOT_STOP_STR2
766 CONFIG_ZERO_BOOTDELAY_CHECK
767 CONFIG_RESET_TO_RETRY
771 Only needed when CONFIG_BOOTDELAY is enabled;
772 define a command string that is automatically executed
773 when no character is read on the console interface
774 within "Boot Delay" after reset.
777 This can be used to pass arguments to the bootm
778 command. The value of CONFIG_BOOTARGS goes into the
779 environment value "bootargs".
781 CONFIG_RAMBOOT and CONFIG_NFSBOOT
782 The value of these goes into the environment as
783 "ramboot" and "nfsboot" respectively, and can be used
784 as a convenience, when switching between booting from
790 When this option is #defined, the existence of the
791 environment variable "preboot" will be checked
792 immediately before starting the CONFIG_BOOTDELAY
793 countdown and/or running the auto-boot command resp.
794 entering interactive mode.
796 This feature is especially useful when "preboot" is
797 automatically generated or modified. For an example
798 see the LWMON board specific code: here "preboot" is
799 modified when the user holds down a certain
800 combination of keys on the (special) keyboard when
803 - Serial Download Echo Mode:
805 If defined to 1, all characters received during a
806 serial download (using the "loads" command) are
807 echoed back. This might be needed by some terminal
808 emulations (like "cu"), but may as well just take
809 time on others. This setting #define's the initial
810 value of the "loads_echo" environment variable.
812 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
814 Select one of the baudrates listed in
815 CONFIG_SYS_BAUDRATE_TABLE, see below.
818 Monitor commands can be included or excluded
819 from the build by using the #include files
820 <config_cmd_all.h> and #undef'ing unwanted
821 commands, or using <config_cmd_default.h>
822 and augmenting with additional #define's
825 The default command configuration includes all commands
826 except those marked below with a "*".
828 CONFIG_CMD_ASKENV * ask for env variable
829 CONFIG_CMD_BDI bdinfo
830 CONFIG_CMD_BEDBUG * Include BedBug Debugger
831 CONFIG_CMD_BMP * BMP support
832 CONFIG_CMD_BSP * Board specific commands
833 CONFIG_CMD_BOOTD bootd
834 CONFIG_CMD_CACHE * icache, dcache
835 CONFIG_CMD_CONSOLE coninfo
836 CONFIG_CMD_CRC32 * crc32
837 CONFIG_CMD_DATE * support for RTC, date/time...
838 CONFIG_CMD_DHCP * DHCP support
839 CONFIG_CMD_DIAG * Diagnostics
840 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
841 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
842 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
843 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
844 CONFIG_CMD_DTT * Digital Therm and Thermostat
845 CONFIG_CMD_ECHO echo arguments
846 CONFIG_CMD_EDITENV edit env variable
847 CONFIG_CMD_EEPROM * EEPROM read/write support
848 CONFIG_CMD_ELF * bootelf, bootvx
849 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
850 CONFIG_CMD_ENV_FLAGS * display details about env flags
851 CONFIG_CMD_ENV_EXISTS * check existence of env variable
852 CONFIG_CMD_EXPORTENV * export the environment
853 CONFIG_CMD_EXT2 * ext2 command support
854 CONFIG_CMD_EXT4 * ext4 command support
855 CONFIG_CMD_SAVEENV saveenv
856 CONFIG_CMD_FDC * Floppy Disk Support
857 CONFIG_CMD_FAT * FAT command support
858 CONFIG_CMD_FDOS * Dos diskette Support
859 CONFIG_CMD_FLASH flinfo, erase, protect
860 CONFIG_CMD_FPGA FPGA device initialization support
861 CONFIG_CMD_FUSE * Device fuse support
862 CONFIG_CMD_GETTIME * Get time since boot
863 CONFIG_CMD_GO * the 'go' command (exec code)
864 CONFIG_CMD_GREPENV * search environment
865 CONFIG_CMD_HASH * calculate hash / digest
866 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
867 CONFIG_CMD_I2C * I2C serial bus support
868 CONFIG_CMD_IDE * IDE harddisk support
869 CONFIG_CMD_IMI iminfo
870 CONFIG_CMD_IMLS List all images found in NOR flash
871 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
872 CONFIG_CMD_IMMAP * IMMR dump support
873 CONFIG_CMD_IMPORTENV * import an environment
874 CONFIG_CMD_INI * import data from an ini file into the env
875 CONFIG_CMD_IRQ * irqinfo
876 CONFIG_CMD_ITEST Integer/string test of 2 values
877 CONFIG_CMD_JFFS2 * JFFS2 Support
878 CONFIG_CMD_KGDB * kgdb
879 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
880 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
882 CONFIG_CMD_LOADB loadb
883 CONFIG_CMD_LOADS loads
884 CONFIG_CMD_MD5SUM * print md5 message digest
885 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
886 CONFIG_CMD_MEMINFO * Display detailed memory information
887 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
889 CONFIG_CMD_MEMTEST * mtest
890 CONFIG_CMD_MISC Misc functions like sleep etc
891 CONFIG_CMD_MMC * MMC memory mapped support
892 CONFIG_CMD_MII * MII utility commands
893 CONFIG_CMD_MTDPARTS * MTD partition support
894 CONFIG_CMD_NAND * NAND support
895 CONFIG_CMD_NET bootp, tftpboot, rarpboot
896 CONFIG_CMD_NFS NFS support
897 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
898 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
899 CONFIG_CMD_PCI * pciinfo
900 CONFIG_CMD_PCMCIA * PCMCIA support
901 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
903 CONFIG_CMD_PORTIO * Port I/O
904 CONFIG_CMD_READ * Read raw data from partition
905 CONFIG_CMD_REGINFO * Register dump
906 CONFIG_CMD_RUN run command in env variable
907 CONFIG_CMD_SANDBOX * sb command to access sandbox features
908 CONFIG_CMD_SAVES * save S record dump
909 CONFIG_CMD_SCSI * SCSI Support
910 CONFIG_CMD_SDRAM * print SDRAM configuration information
911 (requires CONFIG_CMD_I2C)
912 CONFIG_CMD_SETGETDCR Support for DCR Register access
914 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
915 CONFIG_CMD_SHA1SUM * print sha1 memory digest
916 (requires CONFIG_CMD_MEMORY)
917 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
918 CONFIG_CMD_SOURCE "source" command Support
919 CONFIG_CMD_SPI * SPI serial bus support
920 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
921 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
922 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
923 CONFIG_CMD_TIMER * access to the system tick timer
924 CONFIG_CMD_USB * USB support
925 CONFIG_CMD_CDP * Cisco Discover Protocol support
926 CONFIG_CMD_MFSL * Microblaze FSL support
927 CONFIG_CMD_XIMG Load part of Multi Image
930 EXAMPLE: If you want all functions except of network
931 support you can write:
933 #include "config_cmd_all.h"
934 #undef CONFIG_CMD_NET
937 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
939 Note: Don't enable the "icache" and "dcache" commands
940 (configuration option CONFIG_CMD_CACHE) unless you know
941 what you (and your U-Boot users) are doing. Data
942 cache cannot be enabled on systems like the 8xx or
943 8260 (where accesses to the IMMR region must be
944 uncached), and it cannot be disabled on all other
945 systems where we (mis-) use the data cache to hold an
946 initial stack and some data.
949 XXX - this list needs to get updated!
951 - Regular expression support:
953 If this variable is defined, U-Boot is linked against
954 the SLRE (Super Light Regular Expression) library,
955 which adds regex support to some commands, as for
956 example "env grep" and "setexpr".
960 If this variable is defined, U-Boot will use a device tree
961 to configure its devices, instead of relying on statically
962 compiled #defines in the board file. This option is
963 experimental and only available on a few boards. The device
964 tree is available in the global data as gd->fdt_blob.
966 U-Boot needs to get its device tree from somewhere. This can
967 be done using one of the two options below:
970 If this variable is defined, U-Boot will embed a device tree
971 binary in its image. This device tree file should be in the
972 board directory and called <soc>-<board>.dts. The binary file
973 is then picked up in board_init_f() and made available through
974 the global data structure as gd->blob.
977 If this variable is defined, U-Boot will build a device tree
978 binary. It will be called u-boot.dtb. Architecture-specific
979 code will locate it at run-time. Generally this works by:
981 cat u-boot.bin u-boot.dtb >image.bin
983 and in fact, U-Boot does this for you, creating a file called
984 u-boot-dtb.bin which is useful in the common case. You can
985 still use the individual files if you need something more
990 If this variable is defined, it enables watchdog
991 support for the SoC. There must be support in the SoC
992 specific code for a watchdog. For the 8xx and 8260
993 CPUs, the SIU Watchdog feature is enabled in the SYPCR
994 register. When supported for a specific SoC is
995 available, then no further board specific code should
999 When using a watchdog circuitry external to the used
1000 SoC, then define this variable and provide board
1001 specific code for the "hw_watchdog_reset" function.
1004 CONFIG_VERSION_VARIABLE
1005 If this variable is defined, an environment variable
1006 named "ver" is created by U-Boot showing the U-Boot
1007 version as printed by the "version" command.
1008 Any change to this variable will be reverted at the
1013 When CONFIG_CMD_DATE is selected, the type of the RTC
1014 has to be selected, too. Define exactly one of the
1017 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1018 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1019 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1020 CONFIG_RTC_MC146818 - use MC146818 RTC
1021 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1022 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1023 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1024 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1025 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1026 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1027 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1028 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1031 Note that if the RTC uses I2C, then the I2C interface
1032 must also be configured. See I2C Support, below.
1035 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1037 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1038 chip-ngpio pairs that tell the PCA953X driver the number of
1039 pins supported by a particular chip.
1041 Note that if the GPIO device uses I2C, then the I2C interface
1042 must also be configured. See I2C Support, below.
1044 - Timestamp Support:
1046 When CONFIG_TIMESTAMP is selected, the timestamp
1047 (date and time) of an image is printed by image
1048 commands like bootm or iminfo. This option is
1049 automatically enabled when you select CONFIG_CMD_DATE .
1051 - Partition Labels (disklabels) Supported:
1052 Zero or more of the following:
1053 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1054 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1055 Intel architecture, USB sticks, etc.
1056 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1057 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1058 bootloader. Note 2TB partition limit; see
1060 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1062 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1063 CONFIG_CMD_SCSI) you must configure support for at
1064 least one non-MTD partition type as well.
1067 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1068 board configurations files but used nowhere!
1070 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1071 be performed by calling the function
1072 ide_set_reset(int reset)
1073 which has to be defined in a board specific file
1078 Set this to enable ATAPI support.
1083 Set this to enable support for disks larger than 137GB
1084 Also look at CONFIG_SYS_64BIT_LBA.
1085 Whithout these , LBA48 support uses 32bit variables and will 'only'
1086 support disks up to 2.1TB.
1088 CONFIG_SYS_64BIT_LBA:
1089 When enabled, makes the IDE subsystem use 64bit sector addresses.
1093 At the moment only there is only support for the
1094 SYM53C8XX SCSI controller; define
1095 CONFIG_SCSI_SYM53C8XX to enable it.
1097 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1098 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1099 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1100 maximum numbers of LUNs, SCSI ID's and target
1102 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1104 The environment variable 'scsidevs' is set to the number of
1105 SCSI devices found during the last scan.
1107 - NETWORK Support (PCI):
1109 Support for Intel 8254x/8257x gigabit chips.
1112 Utility code for direct access to the SPI bus on Intel 8257x.
1113 This does not do anything useful unless you set at least one
1114 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1116 CONFIG_E1000_SPI_GENERIC
1117 Allow generic access to the SPI bus on the Intel 8257x, for
1118 example with the "sspi" command.
1121 Management command for E1000 devices. When used on devices
1122 with SPI support you can reprogram the EEPROM from U-Boot.
1124 CONFIG_E1000_FALLBACK_MAC
1125 default MAC for empty EEPROM after production.
1128 Support for Intel 82557/82559/82559ER chips.
1129 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1130 write routine for first time initialisation.
1133 Support for Digital 2114x chips.
1134 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1135 modem chip initialisation (KS8761/QS6611).
1138 Support for National dp83815 chips.
1141 Support for National dp8382[01] gigabit chips.
1143 - NETWORK Support (other):
1145 CONFIG_DRIVER_AT91EMAC
1146 Support for AT91RM9200 EMAC.
1149 Define this to use reduced MII inteface
1151 CONFIG_DRIVER_AT91EMAC_QUIET
1152 If this defined, the driver is quiet.
1153 The driver doen't show link status messages.
1155 CONFIG_CALXEDA_XGMAC
1156 Support for the Calxeda XGMAC device
1159 Support for SMSC's LAN91C96 chips.
1161 CONFIG_LAN91C96_BASE
1162 Define this to hold the physical address
1163 of the LAN91C96's I/O space
1165 CONFIG_LAN91C96_USE_32_BIT
1166 Define this to enable 32 bit addressing
1169 Support for SMSC's LAN91C111 chip
1171 CONFIG_SMC91111_BASE
1172 Define this to hold the physical address
1173 of the device (I/O space)
1175 CONFIG_SMC_USE_32_BIT
1176 Define this if data bus is 32 bits
1178 CONFIG_SMC_USE_IOFUNCS
1179 Define this to use i/o functions instead of macros
1180 (some hardware wont work with macros)
1182 CONFIG_DRIVER_TI_EMAC
1183 Support for davinci emac
1185 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1186 Define this if you have more then 3 PHYs.
1189 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1191 CONFIG_FTGMAC100_EGIGA
1192 Define this to use GE link update with gigabit PHY.
1193 Define this if FTGMAC100 is connected to gigabit PHY.
1194 If your system has 10/100 PHY only, it might not occur
1195 wrong behavior. Because PHY usually return timeout or
1196 useless data when polling gigabit status and gigabit
1197 control registers. This behavior won't affect the
1198 correctnessof 10/100 link speed update.
1201 Support for SMSC's LAN911x and LAN921x chips
1204 Define this to hold the physical address
1205 of the device (I/O space)
1207 CONFIG_SMC911X_32_BIT
1208 Define this if data bus is 32 bits
1210 CONFIG_SMC911X_16_BIT
1211 Define this if data bus is 16 bits. If your processor
1212 automatically converts one 32 bit word to two 16 bit
1213 words you may also try CONFIG_SMC911X_32_BIT.
1216 Support for Renesas on-chip Ethernet controller
1218 CONFIG_SH_ETHER_USE_PORT
1219 Define the number of ports to be used
1221 CONFIG_SH_ETHER_PHY_ADDR
1222 Define the ETH PHY's address
1224 CONFIG_SH_ETHER_CACHE_WRITEBACK
1225 If this option is set, the driver enables cache flush.
1229 Support TPM devices.
1232 Support for i2c bus TPM devices. Only one device
1233 per system is supported at this time.
1235 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1236 Define the the i2c bus number for the TPM device
1238 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1239 Define the TPM's address on the i2c bus
1241 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1242 Define the burst count bytes upper limit
1244 CONFIG_TPM_ATMEL_TWI
1245 Support for Atmel TWI TPM device. Requires I2C support.
1248 Support for generic parallel port TPM devices. Only one device
1249 per system is supported at this time.
1251 CONFIG_TPM_TIS_BASE_ADDRESS
1252 Base address where the generic TPM device is mapped
1253 to. Contemporary x86 systems usually map it at
1257 Add tpm monitor functions.
1258 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1259 provides monitor access to authorized functions.
1262 Define this to enable the TPM support library which provides
1263 functional interfaces to some TPM commands.
1264 Requires support for a TPM device.
1266 CONFIG_TPM_AUTH_SESSIONS
1267 Define this to enable authorized functions in the TPM library.
1268 Requires CONFIG_TPM and CONFIG_SHA1.
1271 At the moment only the UHCI host controller is
1272 supported (PIP405, MIP405, MPC5200); define
1273 CONFIG_USB_UHCI to enable it.
1274 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1275 and define CONFIG_USB_STORAGE to enable the USB
1278 Supported are USB Keyboards and USB Floppy drives
1280 MPC5200 USB requires additional defines:
1282 for 528 MHz Clock: 0x0001bbbb
1286 for differential drivers: 0x00001000
1287 for single ended drivers: 0x00005000
1288 for differential drivers on PSC3: 0x00000100
1289 for single ended drivers on PSC3: 0x00004100
1290 CONFIG_SYS_USB_EVENT_POLL
1291 May be defined to allow interrupt polling
1292 instead of using asynchronous interrupts
1294 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1295 txfilltuning field in the EHCI controller on reset.
1297 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1298 interval for usb hub power-on delay.(minimum 100msec)
1301 Define the below if you wish to use the USB console.
1302 Once firmware is rebuilt from a serial console issue the
1303 command "setenv stdin usbtty; setenv stdout usbtty" and
1304 attach your USB cable. The Unix command "dmesg" should print
1305 it has found a new device. The environment variable usbtty
1306 can be set to gserial or cdc_acm to enable your device to
1307 appear to a USB host as a Linux gserial device or a
1308 Common Device Class Abstract Control Model serial device.
1309 If you select usbtty = gserial you should be able to enumerate
1311 # modprobe usbserial vendor=0xVendorID product=0xProductID
1312 else if using cdc_acm, simply setting the environment
1313 variable usbtty to be cdc_acm should suffice. The following
1314 might be defined in YourBoardName.h
1317 Define this to build a UDC device
1320 Define this to have a tty type of device available to
1321 talk to the UDC device
1324 Define this to enable the high speed support for usb
1325 device and usbtty. If this feature is enabled, a routine
1326 int is_usbd_high_speed(void)
1327 also needs to be defined by the driver to dynamically poll
1328 whether the enumeration has succeded at high speed or full
1331 CONFIG_SYS_CONSOLE_IS_IN_ENV
1332 Define this if you want stdin, stdout &/or stderr to
1336 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1337 Derive USB clock from external clock "blah"
1338 - CONFIG_SYS_USB_EXTC_CLK 0x02
1340 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1341 Derive USB clock from brgclk
1342 - CONFIG_SYS_USB_BRG_CLK 0x04
1344 If you have a USB-IF assigned VendorID then you may wish to
1345 define your own vendor specific values either in BoardName.h
1346 or directly in usbd_vendor_info.h. If you don't define
1347 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1348 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1349 should pretend to be a Linux device to it's target host.
1351 CONFIG_USBD_MANUFACTURER
1352 Define this string as the name of your company for
1353 - CONFIG_USBD_MANUFACTURER "my company"
1355 CONFIG_USBD_PRODUCT_NAME
1356 Define this string as the name of your product
1357 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1359 CONFIG_USBD_VENDORID
1360 Define this as your assigned Vendor ID from the USB
1361 Implementors Forum. This *must* be a genuine Vendor ID
1362 to avoid polluting the USB namespace.
1363 - CONFIG_USBD_VENDORID 0xFFFF
1365 CONFIG_USBD_PRODUCTID
1366 Define this as the unique Product ID
1368 - CONFIG_USBD_PRODUCTID 0xFFFF
1370 Some USB device drivers may need to check USB cable attachment.
1371 In this case you can enable following config in BoardName.h:
1372 CONFIG_USB_CABLE_CHECK
1373 This enables function definition:
1374 - usb_cable_connected() in include/usb.h
1375 Implementation of this function is board-specific.
1377 - ULPI Layer Support:
1378 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1379 the generic ULPI layer. The generic layer accesses the ULPI PHY
1380 via the platform viewport, so you need both the genric layer and
1381 the viewport enabled. Currently only Chipidea/ARC based
1382 viewport is supported.
1383 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1384 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1385 If your ULPI phy needs a different reference clock than the
1386 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1387 the appropriate value in Hz.
1390 The MMC controller on the Intel PXA is supported. To
1391 enable this define CONFIG_MMC. The MMC can be
1392 accessed from the boot prompt by mapping the device
1393 to physical memory similar to flash. Command line is
1394 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1395 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1398 Support for Renesas on-chip MMCIF controller
1400 CONFIG_SH_MMCIF_ADDR
1401 Define the base address of MMCIF registers
1404 Define the clock frequency for MMCIF
1406 - USB Device Firmware Update (DFU) class support:
1408 This enables the USB portion of the DFU USB class
1411 This enables the command "dfu" which is used to have
1412 U-Boot create a DFU class device via USB. This command
1413 requires that the "dfu_alt_info" environment variable be
1414 set and define the alt settings to expose to the host.
1417 This enables support for exposing (e)MMC devices via DFU.
1420 This enables support for exposing NAND devices via DFU.
1423 This enables support for exposing RAM via DFU.
1424 Note: DFU spec refer to non-volatile memory usage, but
1425 allow usages beyond the scope of spec - here RAM usage,
1426 one that would help mostly the developer.
1428 CONFIG_SYS_DFU_DATA_BUF_SIZE
1429 Dfu transfer uses a buffer before writing data to the
1430 raw storage device. Make the size (in bytes) of this buffer
1431 configurable. The size of this buffer is also configurable
1432 through the "dfu_bufsiz" environment variable.
1434 CONFIG_SYS_DFU_MAX_FILE_SIZE
1435 When updating files rather than the raw storage device,
1436 we use a static buffer to copy the file into and then write
1437 the buffer once we've been given the whole file. Define
1438 this to the maximum filesize (in bytes) for the buffer.
1439 Default is 4 MiB if undefined.
1441 - Journaling Flash filesystem support:
1442 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1443 CONFIG_JFFS2_NAND_DEV
1444 Define these for a default partition on a NAND device
1446 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1447 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1448 Define these for a default partition on a NOR device
1450 CONFIG_SYS_JFFS_CUSTOM_PART
1451 Define this to create an own partition. You have to provide a
1452 function struct part_info* jffs2_part_info(int part_num)
1454 If you define only one JFFS2 partition you may also want to
1455 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1456 to disable the command chpart. This is the default when you
1457 have not defined a custom partition
1459 - FAT(File Allocation Table) filesystem write function support:
1462 Define this to enable support for saving memory data as a
1463 file in FAT formatted partition.
1465 This will also enable the command "fatwrite" enabling the
1466 user to write files to FAT.
1468 CBFS (Coreboot Filesystem) support
1471 Define this to enable support for reading from a Coreboot
1472 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1478 Define this to enable standard (PC-Style) keyboard
1482 Standard PC keyboard driver with US (is default) and
1483 GERMAN key layout (switch via environment 'keymap=de') support.
1484 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1485 for cfb_console. Supports cursor blinking.
1488 Enables a Chrome OS keyboard using the CROS_EC interface.
1489 This uses CROS_EC to communicate with a second microcontroller
1490 which provides key scans on request.
1495 Define this to enable video support (for output to
1498 CONFIG_VIDEO_CT69000
1500 Enable Chips & Technologies 69000 Video chip
1502 CONFIG_VIDEO_SMI_LYNXEM
1503 Enable Silicon Motion SMI 712/710/810 Video chip. The
1504 video output is selected via environment 'videoout'
1505 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1508 For the CT69000 and SMI_LYNXEM drivers, videomode is
1509 selected via environment 'videomode'. Two different ways
1511 - "videomode=num" 'num' is a standard LiLo mode numbers.
1512 Following standard modes are supported (* is default):
1514 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1515 -------------+---------------------------------------------
1516 8 bits | 0x301* 0x303 0x305 0x161 0x307
1517 15 bits | 0x310 0x313 0x316 0x162 0x319
1518 16 bits | 0x311 0x314 0x317 0x163 0x31A
1519 24 bits | 0x312 0x315 0x318 ? 0x31B
1520 -------------+---------------------------------------------
1521 (i.e. setenv videomode 317; saveenv; reset;)
1523 - "videomode=bootargs" all the video parameters are parsed
1524 from the bootargs. (See drivers/video/videomodes.c)
1527 CONFIG_VIDEO_SED13806
1528 Enable Epson SED13806 driver. This driver supports 8bpp
1529 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1530 or CONFIG_VIDEO_SED13806_16BPP
1533 Enable the Freescale DIU video driver. Reference boards for
1534 SOCs that have a DIU should define this macro to enable DIU
1535 support, and should also define these other macros:
1541 CONFIG_VIDEO_SW_CURSOR
1542 CONFIG_VGA_AS_SINGLE_DEVICE
1544 CONFIG_VIDEO_BMP_LOGO
1546 The DIU driver will look for the 'video-mode' environment
1547 variable, and if defined, enable the DIU as a console during
1548 boot. See the documentation file README.video for a
1549 description of this variable.
1553 Enable the VGA video / BIOS for x86. The alternative if you
1554 are using coreboot is to use the coreboot frame buffer
1561 Define this to enable a custom keyboard support.
1562 This simply calls drv_keyboard_init() which must be
1563 defined in your board-specific files.
1564 The only board using this so far is RBC823.
1566 - LCD Support: CONFIG_LCD
1568 Define this to enable LCD support (for output to LCD
1569 display); also select one of the supported displays
1570 by defining one of these:
1574 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1576 CONFIG_NEC_NL6448AC33:
1578 NEC NL6448AC33-18. Active, color, single scan.
1580 CONFIG_NEC_NL6448BC20
1582 NEC NL6448BC20-08. 6.5", 640x480.
1583 Active, color, single scan.
1585 CONFIG_NEC_NL6448BC33_54
1587 NEC NL6448BC33-54. 10.4", 640x480.
1588 Active, color, single scan.
1592 Sharp 320x240. Active, color, single scan.
1593 It isn't 16x9, and I am not sure what it is.
1595 CONFIG_SHARP_LQ64D341
1597 Sharp LQ64D341 display, 640x480.
1598 Active, color, single scan.
1602 HLD1045 display, 640x480.
1603 Active, color, single scan.
1607 Optrex CBL50840-2 NF-FW 99 22 M5
1609 Hitachi LMG6912RPFC-00T
1613 320x240. Black & white.
1615 Normally display is black on white background; define
1616 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1618 CONFIG_LCD_ALIGNMENT
1620 Normally the LCD is page-aligned (tyically 4KB). If this is
1621 defined then the LCD will be aligned to this value instead.
1622 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1623 here, since it is cheaper to change data cache settings on
1624 a per-section basis.
1626 CONFIG_CONSOLE_SCROLL_LINES
1628 When the console need to be scrolled, this is the number of
1629 lines to scroll by. It defaults to 1. Increasing this makes
1630 the console jump but can help speed up operation when scrolling
1635 Support drawing of RLE8-compressed bitmaps on the LCD.
1639 Enables an 'i2c edid' command which can read EDID
1640 information over I2C from an attached LCD display.
1642 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1644 If this option is set, the environment is checked for
1645 a variable "splashimage". If found, the usual display
1646 of logo, copyright and system information on the LCD
1647 is suppressed and the BMP image at the address
1648 specified in "splashimage" is loaded instead. The
1649 console is redirected to the "nulldev", too. This
1650 allows for a "silent" boot where a splash screen is
1651 loaded very quickly after power-on.
1653 CONFIG_SPLASHIMAGE_GUARD
1655 If this option is set, then U-Boot will prevent the environment
1656 variable "splashimage" from being set to a problematic address
1657 (see README.displaying-bmps and README.arm-unaligned-accesses).
1658 This option is useful for targets where, due to alignment
1659 restrictions, an improperly aligned BMP image will cause a data
1660 abort. If you think you will not have problems with unaligned
1661 accesses (for example because your toolchain prevents them)
1662 there is no need to set this option.
1664 CONFIG_SPLASH_SCREEN_ALIGN
1666 If this option is set the splash image can be freely positioned
1667 on the screen. Environment variable "splashpos" specifies the
1668 position as "x,y". If a positive number is given it is used as
1669 number of pixel from left/top. If a negative number is given it
1670 is used as number of pixel from right/bottom. You can also
1671 specify 'm' for centering the image.
1674 setenv splashpos m,m
1675 => image at center of screen
1677 setenv splashpos 30,20
1678 => image at x = 30 and y = 20
1680 setenv splashpos -10,m
1681 => vertically centered image
1682 at x = dspWidth - bmpWidth - 9
1684 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1686 If this option is set, additionally to standard BMP
1687 images, gzipped BMP images can be displayed via the
1688 splashscreen support or the bmp command.
1690 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1692 If this option is set, 8-bit RLE compressed BMP images
1693 can be displayed via the splashscreen support or the
1696 - Do compresssing for memory range:
1699 If this option is set, it would use zlib deflate method
1700 to compress the specified memory at its best effort.
1702 - Compression support:
1705 Enabled by default to support gzip compressed images.
1709 If this option is set, support for bzip2 compressed
1710 images is included. If not, only uncompressed and gzip
1711 compressed images are supported.
1713 NOTE: the bzip2 algorithm requires a lot of RAM, so
1714 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1719 If this option is set, support for lzma compressed
1722 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1723 requires an amount of dynamic memory that is given by the
1726 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1728 Where lc and lp stand for, respectively, Literal context bits
1729 and Literal pos bits.
1731 This value is upper-bounded by 14MB in the worst case. Anyway,
1732 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1733 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1734 a very small buffer.
1736 Use the lzmainfo tool to determinate the lc and lp values and
1737 then calculate the amount of needed dynamic memory (ensuring
1738 the appropriate CONFIG_SYS_MALLOC_LEN value).
1742 If this option is set, support for LZO compressed images
1748 The address of PHY on MII bus.
1750 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1752 The clock frequency of the MII bus
1756 If this option is set, support for speed/duplex
1757 detection of gigabit PHY is included.
1759 CONFIG_PHY_RESET_DELAY
1761 Some PHY like Intel LXT971A need extra delay after
1762 reset before any MII register access is possible.
1763 For such PHY, set this option to the usec delay
1764 required. (minimum 300usec for LXT971A)
1766 CONFIG_PHY_CMD_DELAY (ppc4xx)
1768 Some PHY like Intel LXT971A need extra delay after
1769 command issued before MII status register can be read
1779 Define a default value for Ethernet address to use
1780 for the respective Ethernet interface, in case this
1781 is not determined automatically.
1786 Define a default value for the IP address to use for
1787 the default Ethernet interface, in case this is not
1788 determined through e.g. bootp.
1789 (Environment variable "ipaddr")
1791 - Server IP address:
1794 Defines a default value for the IP address of a TFTP
1795 server to contact when using the "tftboot" command.
1796 (Environment variable "serverip")
1798 CONFIG_KEEP_SERVERADDR
1800 Keeps the server's MAC address, in the env 'serveraddr'
1801 for passing to bootargs (like Linux's netconsole option)
1803 - Gateway IP address:
1806 Defines a default value for the IP address of the
1807 default router where packets to other networks are
1809 (Environment variable "gatewayip")
1814 Defines a default value for the subnet mask (or
1815 routing prefix) which is used to determine if an IP
1816 address belongs to the local subnet or needs to be
1817 forwarded through a router.
1818 (Environment variable "netmask")
1820 - Multicast TFTP Mode:
1823 Defines whether you want to support multicast TFTP as per
1824 rfc-2090; for example to work with atftp. Lets lots of targets
1825 tftp down the same boot image concurrently. Note: the Ethernet
1826 driver in use must provide a function: mcast() to join/leave a
1829 - BOOTP Recovery Mode:
1830 CONFIG_BOOTP_RANDOM_DELAY
1832 If you have many targets in a network that try to
1833 boot using BOOTP, you may want to avoid that all
1834 systems send out BOOTP requests at precisely the same
1835 moment (which would happen for instance at recovery
1836 from a power failure, when all systems will try to
1837 boot, thus flooding the BOOTP server. Defining
1838 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1839 inserted before sending out BOOTP requests. The
1840 following delays are inserted then:
1842 1st BOOTP request: delay 0 ... 1 sec
1843 2nd BOOTP request: delay 0 ... 2 sec
1844 3rd BOOTP request: delay 0 ... 4 sec
1846 BOOTP requests: delay 0 ... 8 sec
1848 - DHCP Advanced Options:
1849 You can fine tune the DHCP functionality by defining
1850 CONFIG_BOOTP_* symbols:
1852 CONFIG_BOOTP_SUBNETMASK
1853 CONFIG_BOOTP_GATEWAY
1854 CONFIG_BOOTP_HOSTNAME
1855 CONFIG_BOOTP_NISDOMAIN
1856 CONFIG_BOOTP_BOOTPATH
1857 CONFIG_BOOTP_BOOTFILESIZE
1860 CONFIG_BOOTP_SEND_HOSTNAME
1861 CONFIG_BOOTP_NTPSERVER
1862 CONFIG_BOOTP_TIMEOFFSET
1863 CONFIG_BOOTP_VENDOREX
1864 CONFIG_BOOTP_MAY_FAIL
1866 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1867 environment variable, not the BOOTP server.
1869 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1870 after the configured retry count, the call will fail
1871 instead of starting over. This can be used to fail over
1872 to Link-local IP address configuration if the DHCP server
1875 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1876 serverip from a DHCP server, it is possible that more
1877 than one DNS serverip is offered to the client.
1878 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1879 serverip will be stored in the additional environment
1880 variable "dnsip2". The first DNS serverip is always
1881 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1884 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1885 to do a dynamic update of a DNS server. To do this, they
1886 need the hostname of the DHCP requester.
1887 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1888 of the "hostname" environment variable is passed as
1889 option 12 to the DHCP server.
1891 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1893 A 32bit value in microseconds for a delay between
1894 receiving a "DHCP Offer" and sending the "DHCP Request".
1895 This fixes a problem with certain DHCP servers that don't
1896 respond 100% of the time to a "DHCP request". E.g. On an
1897 AT91RM9200 processor running at 180MHz, this delay needed
1898 to be *at least* 15,000 usec before a Windows Server 2003
1899 DHCP server would reply 100% of the time. I recommend at
1900 least 50,000 usec to be safe. The alternative is to hope
1901 that one of the retries will be successful but note that
1902 the DHCP timeout and retry process takes a longer than
1905 - Link-local IP address negotiation:
1906 Negotiate with other link-local clients on the local network
1907 for an address that doesn't require explicit configuration.
1908 This is especially useful if a DHCP server cannot be guaranteed
1909 to exist in all environments that the device must operate.
1911 See doc/README.link-local for more information.
1914 CONFIG_CDP_DEVICE_ID
1916 The device id used in CDP trigger frames.
1918 CONFIG_CDP_DEVICE_ID_PREFIX
1920 A two character string which is prefixed to the MAC address
1925 A printf format string which contains the ascii name of
1926 the port. Normally is set to "eth%d" which sets
1927 eth0 for the first Ethernet, eth1 for the second etc.
1929 CONFIG_CDP_CAPABILITIES
1931 A 32bit integer which indicates the device capabilities;
1932 0x00000010 for a normal host which does not forwards.
1936 An ascii string containing the version of the software.
1940 An ascii string containing the name of the platform.
1944 A 32bit integer sent on the trigger.
1946 CONFIG_CDP_POWER_CONSUMPTION
1948 A 16bit integer containing the power consumption of the
1949 device in .1 of milliwatts.
1951 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1953 A byte containing the id of the VLAN.
1955 - Status LED: CONFIG_STATUS_LED
1957 Several configurations allow to display the current
1958 status using a LED. For instance, the LED will blink
1959 fast while running U-Boot code, stop blinking as
1960 soon as a reply to a BOOTP request was received, and
1961 start blinking slow once the Linux kernel is running
1962 (supported by a status LED driver in the Linux
1963 kernel). Defining CONFIG_STATUS_LED enables this
1966 - CAN Support: CONFIG_CAN_DRIVER
1968 Defining CONFIG_CAN_DRIVER enables CAN driver support
1969 on those systems that support this (optional)
1970 feature, like the TQM8xxL modules.
1972 - I2C Support: CONFIG_SYS_I2C
1974 This enable the NEW i2c subsystem, and will allow you to use
1975 i2c commands at the u-boot command line (as long as you set
1976 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1977 based realtime clock chips or other i2c devices. See
1978 common/cmd_i2c.c for a description of the command line
1981 ported i2c driver to the new framework:
1982 - drivers/i2c/soft_i2c.c:
1983 - activate first bus with CONFIG_SYS_I2C_SOFT define
1984 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1985 for defining speed and slave address
1986 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1987 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1988 for defining speed and slave address
1989 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1990 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1991 for defining speed and slave address
1992 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1993 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1994 for defining speed and slave address
1996 - drivers/i2c/fsl_i2c.c:
1997 - activate i2c driver with CONFIG_SYS_I2C_FSL
1998 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1999 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2000 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2002 - If your board supports a second fsl i2c bus, define
2003 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2004 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2005 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2008 - drivers/i2c/tegra_i2c.c:
2009 - activate this driver with CONFIG_SYS_I2C_TEGRA
2010 - This driver adds 4 i2c buses with a fix speed from
2011 100000 and the slave addr 0!
2013 - drivers/i2c/ppc4xx_i2c.c
2014 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2015 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2016 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2018 - drivers/i2c/i2c_mxc.c
2019 - activate this driver with CONFIG_SYS_I2C_MXC
2020 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2021 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2022 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2023 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2024 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2025 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2026 If thoses defines are not set, default value is 100000
2027 for speed, and 0 for slave.
2029 - drivers/i2c/rcar_i2c.c:
2030 - activate this driver with CONFIG_SYS_I2C_RCAR
2031 - This driver adds 4 i2c buses
2033 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2034 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2035 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2036 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2037 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2038 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2039 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2040 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2041 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2043 - drivers/i2c/sh_i2c.c:
2044 - activate this driver with CONFIG_SYS_I2C_SH
2045 - This driver adds from 2 to 5 i2c buses
2047 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2048 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2049 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2050 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2051 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2052 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2053 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2054 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2055 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2056 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2057 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2058 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2059 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2063 CONFIG_SYS_NUM_I2C_BUSES
2064 Hold the number of i2c busses you want to use. If you
2065 don't use/have i2c muxes on your i2c bus, this
2066 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2069 CONFIG_SYS_I2C_DIRECT_BUS
2070 define this, if you don't use i2c muxes on your hardware.
2071 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2074 CONFIG_SYS_I2C_MAX_HOPS
2075 define how many muxes are maximal consecutively connected
2076 on one i2c bus. If you not use i2c muxes, omit this
2079 CONFIG_SYS_I2C_BUSES
2080 hold a list of busses you want to use, only used if
2081 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2082 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2083 CONFIG_SYS_NUM_I2C_BUSES = 9:
2085 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2086 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2087 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2088 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2089 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2090 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2091 {1, {I2C_NULL_HOP}}, \
2092 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2093 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2097 bus 0 on adapter 0 without a mux
2098 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2099 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2100 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2101 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2102 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2103 bus 6 on adapter 1 without a mux
2104 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2105 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2107 If you do not have i2c muxes on your board, omit this define.
2109 - Legacy I2C Support: CONFIG_HARD_I2C
2111 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2112 provides the following compelling advantages:
2114 - more than one i2c adapter is usable
2115 - approved multibus support
2116 - better i2c mux support
2118 ** Please consider updating your I2C driver now. **
2120 These enable legacy I2C serial bus commands. Defining
2121 CONFIG_HARD_I2C will include the appropriate I2C driver
2122 for the selected CPU.
2124 This will allow you to use i2c commands at the u-boot
2125 command line (as long as you set CONFIG_CMD_I2C in
2126 CONFIG_COMMANDS) and communicate with i2c based realtime
2127 clock chips. See common/cmd_i2c.c for a description of the
2128 command line interface.
2130 CONFIG_HARD_I2C selects a hardware I2C controller.
2132 There are several other quantities that must also be
2133 defined when you define CONFIG_HARD_I2C.
2135 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2136 to be the frequency (in Hz) at which you wish your i2c bus
2137 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2138 the CPU's i2c node address).
2140 Now, the u-boot i2c code for the mpc8xx
2141 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2142 and so its address should therefore be cleared to 0 (See,
2143 eg, MPC823e User's Manual p.16-473). So, set
2144 CONFIG_SYS_I2C_SLAVE to 0.
2146 CONFIG_SYS_I2C_INIT_MPC5XXX
2148 When a board is reset during an i2c bus transfer
2149 chips might think that the current transfer is still
2150 in progress. Reset the slave devices by sending start
2151 commands until the slave device responds.
2153 That's all that's required for CONFIG_HARD_I2C.
2155 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2156 then the following macros need to be defined (examples are
2157 from include/configs/lwmon.h):
2161 (Optional). Any commands necessary to enable the I2C
2162 controller or configure ports.
2164 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2168 (Only for MPC8260 CPU). The I/O port to use (the code
2169 assumes both bits are on the same port). Valid values
2170 are 0..3 for ports A..D.
2174 The code necessary to make the I2C data line active
2175 (driven). If the data line is open collector, this
2178 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2182 The code necessary to make the I2C data line tri-stated
2183 (inactive). If the data line is open collector, this
2186 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2190 Code that returns true if the I2C data line is high,
2193 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2197 If <bit> is true, sets the I2C data line high. If it
2198 is false, it clears it (low).
2200 eg: #define I2C_SDA(bit) \
2201 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2202 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2206 If <bit> is true, sets the I2C clock line high. If it
2207 is false, it clears it (low).
2209 eg: #define I2C_SCL(bit) \
2210 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2211 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2215 This delay is invoked four times per clock cycle so this
2216 controls the rate of data transfer. The data rate thus
2217 is 1 / (I2C_DELAY * 4). Often defined to be something
2220 #define I2C_DELAY udelay(2)
2222 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2224 If your arch supports the generic GPIO framework (asm/gpio.h),
2225 then you may alternatively define the two GPIOs that are to be
2226 used as SCL / SDA. Any of the previous I2C_xxx macros will
2227 have GPIO-based defaults assigned to them as appropriate.
2229 You should define these to the GPIO value as given directly to
2230 the generic GPIO functions.
2232 CONFIG_SYS_I2C_INIT_BOARD
2234 When a board is reset during an i2c bus transfer
2235 chips might think that the current transfer is still
2236 in progress. On some boards it is possible to access
2237 the i2c SCLK line directly, either by using the
2238 processor pin as a GPIO or by having a second pin
2239 connected to the bus. If this option is defined a
2240 custom i2c_init_board() routine in boards/xxx/board.c
2241 is run early in the boot sequence.
2243 CONFIG_SYS_I2C_BOARD_LATE_INIT
2245 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2246 defined a custom i2c_board_late_init() routine in
2247 boards/xxx/board.c is run AFTER the operations in i2c_init()
2248 is completed. This callpoint can be used to unreset i2c bus
2249 using CPU i2c controller register accesses for CPUs whose i2c
2250 controller provide such a method. It is called at the end of
2251 i2c_init() to allow i2c_init operations to setup the i2c bus
2252 controller on the CPU (e.g. setting bus speed & slave address).
2254 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2256 This option enables configuration of bi_iic_fast[] flags
2257 in u-boot bd_info structure based on u-boot environment
2258 variable "i2cfast". (see also i2cfast)
2260 CONFIG_I2C_MULTI_BUS
2262 This option allows the use of multiple I2C buses, each of which
2263 must have a controller. At any point in time, only one bus is
2264 active. To switch to a different bus, use the 'i2c dev' command.
2265 Note that bus numbering is zero-based.
2267 CONFIG_SYS_I2C_NOPROBES
2269 This option specifies a list of I2C devices that will be skipped
2270 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2271 is set, specify a list of bus-device pairs. Otherwise, specify
2272 a 1D array of device addresses
2275 #undef CONFIG_I2C_MULTI_BUS
2276 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2278 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2280 #define CONFIG_I2C_MULTI_BUS
2281 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2283 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2285 CONFIG_SYS_SPD_BUS_NUM
2287 If defined, then this indicates the I2C bus number for DDR SPD.
2288 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2290 CONFIG_SYS_RTC_BUS_NUM
2292 If defined, then this indicates the I2C bus number for the RTC.
2293 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2295 CONFIG_SYS_DTT_BUS_NUM
2297 If defined, then this indicates the I2C bus number for the DTT.
2298 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2300 CONFIG_SYS_I2C_DTT_ADDR:
2302 If defined, specifies the I2C address of the DTT device.
2303 If not defined, then U-Boot uses predefined value for
2304 specified DTT device.
2306 CONFIG_SOFT_I2C_READ_REPEATED_START
2308 defining this will force the i2c_read() function in
2309 the soft_i2c driver to perform an I2C repeated start
2310 between writing the address pointer and reading the
2311 data. If this define is omitted the default behaviour
2312 of doing a stop-start sequence will be used. Most I2C
2313 devices can use either method, but some require one or
2316 - SPI Support: CONFIG_SPI
2318 Enables SPI driver (so far only tested with
2319 SPI EEPROM, also an instance works with Crystal A/D and
2320 D/As on the SACSng board)
2324 Enables the driver for SPI controller on SuperH. Currently
2325 only SH7757 is supported.
2329 Enables extended (16-bit) SPI EEPROM addressing.
2330 (symmetrical to CONFIG_I2C_X)
2334 Enables a software (bit-bang) SPI driver rather than
2335 using hardware support. This is a general purpose
2336 driver that only requires three general I/O port pins
2337 (two outputs, one input) to function. If this is
2338 defined, the board configuration must define several
2339 SPI configuration items (port pins to use, etc). For
2340 an example, see include/configs/sacsng.h.
2344 Enables a hardware SPI driver for general-purpose reads
2345 and writes. As with CONFIG_SOFT_SPI, the board configuration
2346 must define a list of chip-select function pointers.
2347 Currently supported on some MPC8xxx processors. For an
2348 example, see include/configs/mpc8349emds.h.
2352 Enables the driver for the SPI controllers on i.MX and MXC
2353 SoCs. Currently i.MX31/35/51 are supported.
2355 - FPGA Support: CONFIG_FPGA
2357 Enables FPGA subsystem.
2359 CONFIG_FPGA_<vendor>
2361 Enables support for specific chip vendors.
2364 CONFIG_FPGA_<family>
2366 Enables support for FPGA family.
2367 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2371 Specify the number of FPGA devices to support.
2373 CONFIG_SYS_FPGA_PROG_FEEDBACK
2375 Enable printing of hash marks during FPGA configuration.
2377 CONFIG_SYS_FPGA_CHECK_BUSY
2379 Enable checks on FPGA configuration interface busy
2380 status by the configuration function. This option
2381 will require a board or device specific function to
2386 If defined, a function that provides delays in the FPGA
2387 configuration driver.
2389 CONFIG_SYS_FPGA_CHECK_CTRLC
2390 Allow Control-C to interrupt FPGA configuration
2392 CONFIG_SYS_FPGA_CHECK_ERROR
2394 Check for configuration errors during FPGA bitfile
2395 loading. For example, abort during Virtex II
2396 configuration if the INIT_B line goes low (which
2397 indicated a CRC error).
2399 CONFIG_SYS_FPGA_WAIT_INIT
2401 Maximum time to wait for the INIT_B line to deassert
2402 after PROB_B has been deasserted during a Virtex II
2403 FPGA configuration sequence. The default time is 500
2406 CONFIG_SYS_FPGA_WAIT_BUSY
2408 Maximum time to wait for BUSY to deassert during
2409 Virtex II FPGA configuration. The default is 5 ms.
2411 CONFIG_SYS_FPGA_WAIT_CONFIG
2413 Time to wait after FPGA configuration. The default is
2416 - Configuration Management:
2419 If defined, this string will be added to the U-Boot
2420 version information (U_BOOT_VERSION)
2422 - Vendor Parameter Protection:
2424 U-Boot considers the values of the environment
2425 variables "serial#" (Board Serial Number) and
2426 "ethaddr" (Ethernet Address) to be parameters that
2427 are set once by the board vendor / manufacturer, and
2428 protects these variables from casual modification by
2429 the user. Once set, these variables are read-only,
2430 and write or delete attempts are rejected. You can
2431 change this behaviour:
2433 If CONFIG_ENV_OVERWRITE is #defined in your config
2434 file, the write protection for vendor parameters is
2435 completely disabled. Anybody can change or delete
2438 Alternatively, if you #define _both_ CONFIG_ETHADDR
2439 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2440 Ethernet address is installed in the environment,
2441 which can be changed exactly ONCE by the user. [The
2442 serial# is unaffected by this, i. e. it remains
2445 The same can be accomplished in a more flexible way
2446 for any variable by configuring the type of access
2447 to allow for those variables in the ".flags" variable
2448 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2453 Define this variable to enable the reservation of
2454 "protected RAM", i. e. RAM which is not overwritten
2455 by U-Boot. Define CONFIG_PRAM to hold the number of
2456 kB you want to reserve for pRAM. You can overwrite
2457 this default value by defining an environment
2458 variable "pram" to the number of kB you want to
2459 reserve. Note that the board info structure will
2460 still show the full amount of RAM. If pRAM is
2461 reserved, a new environment variable "mem" will
2462 automatically be defined to hold the amount of
2463 remaining RAM in a form that can be passed as boot
2464 argument to Linux, for instance like that:
2466 setenv bootargs ... mem=\${mem}
2469 This way you can tell Linux not to use this memory,
2470 either, which results in a memory region that will
2471 not be affected by reboots.
2473 *WARNING* If your board configuration uses automatic
2474 detection of the RAM size, you must make sure that
2475 this memory test is non-destructive. So far, the
2476 following board configurations are known to be
2479 IVMS8, IVML24, SPD8xx, TQM8xxL,
2480 HERMES, IP860, RPXlite, LWMON,
2483 - Access to physical memory region (> 4GB)
2484 Some basic support is provided for operations on memory not
2485 normally accessible to U-Boot - e.g. some architectures
2486 support access to more than 4GB of memory on 32-bit
2487 machines using physical address extension or similar.
2488 Define CONFIG_PHYSMEM to access this basic support, which
2489 currently only supports clearing the memory.
2494 Define this variable to stop the system in case of a
2495 fatal error, so that you have to reset it manually.
2496 This is probably NOT a good idea for an embedded
2497 system where you want the system to reboot
2498 automatically as fast as possible, but it may be
2499 useful during development since you can try to debug
2500 the conditions that lead to the situation.
2502 CONFIG_NET_RETRY_COUNT
2504 This variable defines the number of retries for
2505 network operations like ARP, RARP, TFTP, or BOOTP
2506 before giving up the operation. If not defined, a
2507 default value of 5 is used.
2511 Timeout waiting for an ARP reply in milliseconds.
2515 Timeout in milliseconds used in NFS protocol.
2516 If you encounter "ERROR: Cannot umount" in nfs command,
2517 try longer timeout such as
2518 #define CONFIG_NFS_TIMEOUT 10000UL
2520 - Command Interpreter:
2521 CONFIG_AUTO_COMPLETE
2523 Enable auto completion of commands using TAB.
2525 Note that this feature has NOT been implemented yet
2526 for the "hush" shell.
2529 CONFIG_SYS_HUSH_PARSER
2531 Define this variable to enable the "hush" shell (from
2532 Busybox) as command line interpreter, thus enabling
2533 powerful command line syntax like
2534 if...then...else...fi conditionals or `&&' and '||'
2535 constructs ("shell scripts").
2537 If undefined, you get the old, much simpler behaviour
2538 with a somewhat smaller memory footprint.
2541 CONFIG_SYS_PROMPT_HUSH_PS2
2543 This defines the secondary prompt string, which is
2544 printed when the command interpreter needs more input
2545 to complete a command. Usually "> ".
2549 In the current implementation, the local variables
2550 space and global environment variables space are
2551 separated. Local variables are those you define by
2552 simply typing `name=value'. To access a local
2553 variable later on, you have write `$name' or
2554 `${name}'; to execute the contents of a variable
2555 directly type `$name' at the command prompt.
2557 Global environment variables are those you use
2558 setenv/printenv to work with. To run a command stored
2559 in such a variable, you need to use the run command,
2560 and you must not use the '$' sign to access them.
2562 To store commands and special characters in a
2563 variable, please use double quotation marks
2564 surrounding the whole text of the variable, instead
2565 of the backslashes before semicolons and special
2568 - Commandline Editing and History:
2569 CONFIG_CMDLINE_EDITING
2571 Enable editing and History functions for interactive
2572 commandline input operations
2574 - Default Environment:
2575 CONFIG_EXTRA_ENV_SETTINGS
2577 Define this to contain any number of null terminated
2578 strings (variable = value pairs) that will be part of
2579 the default environment compiled into the boot image.
2581 For example, place something like this in your
2582 board's config file:
2584 #define CONFIG_EXTRA_ENV_SETTINGS \
2588 Warning: This method is based on knowledge about the
2589 internal format how the environment is stored by the
2590 U-Boot code. This is NOT an official, exported
2591 interface! Although it is unlikely that this format
2592 will change soon, there is no guarantee either.
2593 You better know what you are doing here.
2595 Note: overly (ab)use of the default environment is
2596 discouraged. Make sure to check other ways to preset
2597 the environment like the "source" command or the
2600 CONFIG_ENV_VARS_UBOOT_CONFIG
2602 Define this in order to add variables describing the
2603 U-Boot build configuration to the default environment.
2604 These will be named arch, cpu, board, vendor, and soc.
2606 Enabling this option will cause the following to be defined:
2614 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2616 Define this in order to add variables describing certain
2617 run-time determined information about the hardware to the
2618 environment. These will be named board_name, board_rev.
2620 CONFIG_DELAY_ENVIRONMENT
2622 Normally the environment is loaded when the board is
2623 intialised so that it is available to U-Boot. This inhibits
2624 that so that the environment is not available until
2625 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2626 this is instead controlled by the value of
2627 /config/load-environment.
2629 - DataFlash Support:
2630 CONFIG_HAS_DATAFLASH
2632 Defining this option enables DataFlash features and
2633 allows to read/write in Dataflash via the standard
2636 - Serial Flash support
2639 Defining this option enables SPI flash commands
2640 'sf probe/read/write/erase/update'.
2642 Usage requires an initial 'probe' to define the serial
2643 flash parameters, followed by read/write/erase/update
2646 The following defaults may be provided by the platform
2647 to handle the common case when only a single serial
2648 flash is present on the system.
2650 CONFIG_SF_DEFAULT_BUS Bus identifier
2651 CONFIG_SF_DEFAULT_CS Chip-select
2652 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2653 CONFIG_SF_DEFAULT_SPEED in Hz
2657 Define this option to include a destructive SPI flash
2660 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2662 Define this option to use the Bank addr/Extended addr
2663 support on SPI flashes which has size > 16Mbytes.
2665 - SystemACE Support:
2668 Adding this option adds support for Xilinx SystemACE
2669 chips attached via some sort of local bus. The address
2670 of the chip must also be defined in the
2671 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2673 #define CONFIG_SYSTEMACE
2674 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2676 When SystemACE support is added, the "ace" device type
2677 becomes available to the fat commands, i.e. fatls.
2679 - TFTP Fixed UDP Port:
2682 If this is defined, the environment variable tftpsrcp
2683 is used to supply the TFTP UDP source port value.
2684 If tftpsrcp isn't defined, the normal pseudo-random port
2685 number generator is used.
2687 Also, the environment variable tftpdstp is used to supply
2688 the TFTP UDP destination port value. If tftpdstp isn't
2689 defined, the normal port 69 is used.
2691 The purpose for tftpsrcp is to allow a TFTP server to
2692 blindly start the TFTP transfer using the pre-configured
2693 target IP address and UDP port. This has the effect of
2694 "punching through" the (Windows XP) firewall, allowing
2695 the remainder of the TFTP transfer to proceed normally.
2696 A better solution is to properly configure the firewall,
2697 but sometimes that is not allowed.
2702 This enables a generic 'hash' command which can produce
2703 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2707 Enable the hash verify command (hash -v). This adds to code
2710 CONFIG_SHA1 - support SHA1 hashing
2711 CONFIG_SHA256 - support SHA256 hashing
2713 Note: There is also a sha1sum command, which should perhaps
2714 be deprecated in favour of 'hash sha1'.
2716 - Freescale i.MX specific commands:
2717 CONFIG_CMD_HDMIDETECT
2718 This enables 'hdmidet' command which returns true if an
2719 HDMI monitor is detected. This command is i.MX 6 specific.
2722 This enables the 'bmode' (bootmode) command for forcing
2723 a boot from specific media.
2725 This is useful for forcing the ROM's usb downloader to
2726 activate upon a watchdog reset which is nice when iterating
2727 on U-Boot. Using the reset button or running bmode normal
2728 will set it back to normal. This command currently
2729 supports i.MX53 and i.MX6.
2734 This enables the RSA algorithm used for FIT image verification
2735 in U-Boot. See doc/uImage/signature for more information.
2737 The signing part is build into mkimage regardless of this
2741 - Show boot progress:
2742 CONFIG_SHOW_BOOT_PROGRESS
2744 Defining this option allows to add some board-
2745 specific code (calling a user-provided function
2746 "show_boot_progress(int)") that enables you to show
2747 the system's boot progress on some display (for
2748 example, some LED's) on your board. At the moment,
2749 the following checkpoints are implemented:
2751 - Detailed boot stage timing
2753 Define this option to get detailed timing of each stage
2754 of the boot process.
2756 CONFIG_BOOTSTAGE_USER_COUNT
2757 This is the number of available user bootstage records.
2758 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2759 a new ID will be allocated from this stash. If you exceed
2760 the limit, recording will stop.
2762 CONFIG_BOOTSTAGE_REPORT
2763 Define this to print a report before boot, similar to this:
2765 Timer summary in microseconds:
2768 3,575,678 3,575,678 board_init_f start
2769 3,575,695 17 arch_cpu_init A9
2770 3,575,777 82 arch_cpu_init done
2771 3,659,598 83,821 board_init_r start
2772 3,910,375 250,777 main_loop
2773 29,916,167 26,005,792 bootm_start
2774 30,361,327 445,160 start_kernel
2776 CONFIG_CMD_BOOTSTAGE
2777 Add a 'bootstage' command which supports printing a report
2778 and un/stashing of bootstage data.
2780 CONFIG_BOOTSTAGE_FDT
2781 Stash the bootstage information in the FDT. A root 'bootstage'
2782 node is created with each bootstage id as a child. Each child
2783 has a 'name' property and either 'mark' containing the
2784 mark time in microsecond, or 'accum' containing the
2785 accumulated time for that bootstage id in microseconds.
2790 name = "board_init_f";
2799 Code in the Linux kernel can find this in /proc/devicetree.
2801 Legacy uImage format:
2804 1 common/cmd_bootm.c before attempting to boot an image
2805 -1 common/cmd_bootm.c Image header has bad magic number
2806 2 common/cmd_bootm.c Image header has correct magic number
2807 -2 common/cmd_bootm.c Image header has bad checksum
2808 3 common/cmd_bootm.c Image header has correct checksum
2809 -3 common/cmd_bootm.c Image data has bad checksum
2810 4 common/cmd_bootm.c Image data has correct checksum
2811 -4 common/cmd_bootm.c Image is for unsupported architecture
2812 5 common/cmd_bootm.c Architecture check OK
2813 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2814 6 common/cmd_bootm.c Image Type check OK
2815 -6 common/cmd_bootm.c gunzip uncompression error
2816 -7 common/cmd_bootm.c Unimplemented compression type
2817 7 common/cmd_bootm.c Uncompression OK
2818 8 common/cmd_bootm.c No uncompress/copy overwrite error
2819 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2821 9 common/image.c Start initial ramdisk verification
2822 -10 common/image.c Ramdisk header has bad magic number
2823 -11 common/image.c Ramdisk header has bad checksum
2824 10 common/image.c Ramdisk header is OK
2825 -12 common/image.c Ramdisk data has bad checksum
2826 11 common/image.c Ramdisk data has correct checksum
2827 12 common/image.c Ramdisk verification complete, start loading
2828 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2829 13 common/image.c Start multifile image verification
2830 14 common/image.c No initial ramdisk, no multifile, continue.
2832 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2834 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2835 -31 post/post.c POST test failed, detected by post_output_backlog()
2836 -32 post/post.c POST test failed, detected by post_run_single()
2838 34 common/cmd_doc.c before loading a Image from a DOC device
2839 -35 common/cmd_doc.c Bad usage of "doc" command
2840 35 common/cmd_doc.c correct usage of "doc" command
2841 -36 common/cmd_doc.c No boot device
2842 36 common/cmd_doc.c correct boot device
2843 -37 common/cmd_doc.c Unknown Chip ID on boot device
2844 37 common/cmd_doc.c correct chip ID found, device available
2845 -38 common/cmd_doc.c Read Error on boot device
2846 38 common/cmd_doc.c reading Image header from DOC device OK
2847 -39 common/cmd_doc.c Image header has bad magic number
2848 39 common/cmd_doc.c Image header has correct magic number
2849 -40 common/cmd_doc.c Error reading Image from DOC device
2850 40 common/cmd_doc.c Image header has correct magic number
2851 41 common/cmd_ide.c before loading a Image from a IDE device
2852 -42 common/cmd_ide.c Bad usage of "ide" command
2853 42 common/cmd_ide.c correct usage of "ide" command
2854 -43 common/cmd_ide.c No boot device
2855 43 common/cmd_ide.c boot device found
2856 -44 common/cmd_ide.c Device not available
2857 44 common/cmd_ide.c Device available
2858 -45 common/cmd_ide.c wrong partition selected
2859 45 common/cmd_ide.c partition selected
2860 -46 common/cmd_ide.c Unknown partition table
2861 46 common/cmd_ide.c valid partition table found
2862 -47 common/cmd_ide.c Invalid partition type
2863 47 common/cmd_ide.c correct partition type
2864 -48 common/cmd_ide.c Error reading Image Header on boot device
2865 48 common/cmd_ide.c reading Image Header from IDE device OK
2866 -49 common/cmd_ide.c Image header has bad magic number
2867 49 common/cmd_ide.c Image header has correct magic number
2868 -50 common/cmd_ide.c Image header has bad checksum
2869 50 common/cmd_ide.c Image header has correct checksum
2870 -51 common/cmd_ide.c Error reading Image from IDE device
2871 51 common/cmd_ide.c reading Image from IDE device OK
2872 52 common/cmd_nand.c before loading a Image from a NAND device
2873 -53 common/cmd_nand.c Bad usage of "nand" command
2874 53 common/cmd_nand.c correct usage of "nand" command
2875 -54 common/cmd_nand.c No boot device
2876 54 common/cmd_nand.c boot device found
2877 -55 common/cmd_nand.c Unknown Chip ID on boot device
2878 55 common/cmd_nand.c correct chip ID found, device available
2879 -56 common/cmd_nand.c Error reading Image Header on boot device
2880 56 common/cmd_nand.c reading Image Header from NAND device OK
2881 -57 common/cmd_nand.c Image header has bad magic number
2882 57 common/cmd_nand.c Image header has correct magic number
2883 -58 common/cmd_nand.c Error reading Image from NAND device
2884 58 common/cmd_nand.c reading Image from NAND device OK
2886 -60 common/env_common.c Environment has a bad CRC, using default
2888 64 net/eth.c starting with Ethernet configuration.
2889 -64 net/eth.c no Ethernet found.
2890 65 net/eth.c Ethernet found.
2892 -80 common/cmd_net.c usage wrong
2893 80 common/cmd_net.c before calling NetLoop()
2894 -81 common/cmd_net.c some error in NetLoop() occurred
2895 81 common/cmd_net.c NetLoop() back without error
2896 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2897 82 common/cmd_net.c trying automatic boot
2898 83 common/cmd_net.c running "source" command
2899 -83 common/cmd_net.c some error in automatic boot or "source" command
2900 84 common/cmd_net.c end without errors
2905 100 common/cmd_bootm.c Kernel FIT Image has correct format
2906 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2907 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2908 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2909 102 common/cmd_bootm.c Kernel unit name specified
2910 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2911 103 common/cmd_bootm.c Found configuration node
2912 104 common/cmd_bootm.c Got kernel subimage node offset
2913 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2914 105 common/cmd_bootm.c Kernel subimage hash verification OK
2915 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2916 106 common/cmd_bootm.c Architecture check OK
2917 -106 common/cmd_bootm.c Kernel subimage has wrong type
2918 107 common/cmd_bootm.c Kernel subimage type OK
2919 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2920 108 common/cmd_bootm.c Got kernel subimage data/size
2921 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2922 -109 common/cmd_bootm.c Can't get kernel subimage type
2923 -110 common/cmd_bootm.c Can't get kernel subimage comp
2924 -111 common/cmd_bootm.c Can't get kernel subimage os
2925 -112 common/cmd_bootm.c Can't get kernel subimage load address
2926 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2928 120 common/image.c Start initial ramdisk verification
2929 -120 common/image.c Ramdisk FIT image has incorrect format
2930 121 common/image.c Ramdisk FIT image has correct format
2931 122 common/image.c No ramdisk subimage unit name, using configuration
2932 -122 common/image.c Can't get configuration for ramdisk subimage
2933 123 common/image.c Ramdisk unit name specified
2934 -124 common/image.c Can't get ramdisk subimage node offset
2935 125 common/image.c Got ramdisk subimage node offset
2936 -125 common/image.c Ramdisk subimage hash verification failed
2937 126 common/image.c Ramdisk subimage hash verification OK
2938 -126 common/image.c Ramdisk subimage for unsupported architecture
2939 127 common/image.c Architecture check OK
2940 -127 common/image.c Can't get ramdisk subimage data/size
2941 128 common/image.c Got ramdisk subimage data/size
2942 129 common/image.c Can't get ramdisk load address
2943 -129 common/image.c Got ramdisk load address
2945 -130 common/cmd_doc.c Incorrect FIT image format
2946 131 common/cmd_doc.c FIT image format OK
2948 -140 common/cmd_ide.c Incorrect FIT image format
2949 141 common/cmd_ide.c FIT image format OK
2951 -150 common/cmd_nand.c Incorrect FIT image format
2952 151 common/cmd_nand.c FIT image format OK
2954 - FIT image support:
2956 Enable support for the FIT uImage format.
2958 CONFIG_FIT_BEST_MATCH
2959 When no configuration is explicitly selected, default to the
2960 one whose fdt's compatibility field best matches that of
2961 U-Boot itself. A match is considered "best" if it matches the
2962 most specific compatibility entry of U-Boot's fdt's root node.
2963 The order of entries in the configuration's fdt is ignored.
2965 CONFIG_FIT_SIGNATURE
2966 This option enables signature verification of FIT uImages,
2967 using a hash signed and verified using RSA. See
2968 doc/uImage.FIT/signature.txt for more details.
2970 - Standalone program support:
2971 CONFIG_STANDALONE_LOAD_ADDR
2973 This option defines a board specific value for the
2974 address where standalone program gets loaded, thus
2975 overwriting the architecture dependent default
2978 - Frame Buffer Address:
2981 Define CONFIG_FB_ADDR if you want to use specific
2982 address for frame buffer. This is typically the case
2983 when using a graphics controller has separate video
2984 memory. U-Boot will then place the frame buffer at
2985 the given address instead of dynamically reserving it
2986 in system RAM by calling lcd_setmem(), which grabs
2987 the memory for the frame buffer depending on the
2988 configured panel size.
2990 Please see board_init_f function.
2992 - Automatic software updates via TFTP server
2994 CONFIG_UPDATE_TFTP_CNT_MAX
2995 CONFIG_UPDATE_TFTP_MSEC_MAX
2997 These options enable and control the auto-update feature;
2998 for a more detailed description refer to doc/README.update.
3000 - MTD Support (mtdparts command, UBI support)
3003 Adds the MTD device infrastructure from the Linux kernel.
3004 Needed for mtdparts command support.
3006 CONFIG_MTD_PARTITIONS
3008 Adds the MTD partitioning infrastructure from the Linux
3009 kernel. Needed for UBI support.
3014 Adds commands for interacting with MTD partitions formatted
3015 with the UBI flash translation layer
3017 Requires also defining CONFIG_RBTREE
3019 CONFIG_UBI_SILENCE_MSG
3021 Make the verbose messages from UBI stop printing. This leaves
3022 warnings and errors enabled.
3027 Adds commands for interacting with UBI volumes formatted as
3028 UBIFS. UBIFS is read-only in u-boot.
3030 Requires UBI support as well as CONFIG_LZO
3032 CONFIG_UBIFS_SILENCE_MSG
3034 Make the verbose messages from UBIFS stop printing. This leaves
3035 warnings and errors enabled.
3039 Enable building of SPL globally.
3042 LDSCRIPT for linking the SPL binary.
3044 CONFIG_SPL_MAX_FOOTPRINT
3045 Maximum size in memory allocated to the SPL, BSS included.
3046 When defined, the linker checks that the actual memory
3047 used by SPL from _start to __bss_end does not exceed it.
3048 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3049 must not be both defined at the same time.
3052 Maximum size of the SPL image (text, data, rodata, and
3053 linker lists sections), BSS excluded.
3054 When defined, the linker checks that the actual size does
3057 CONFIG_SPL_TEXT_BASE
3058 TEXT_BASE for linking the SPL binary.
3060 CONFIG_SPL_RELOC_TEXT_BASE
3061 Address to relocate to. If unspecified, this is equal to
3062 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3064 CONFIG_SPL_BSS_START_ADDR
3065 Link address for the BSS within the SPL binary.
3067 CONFIG_SPL_BSS_MAX_SIZE
3068 Maximum size in memory allocated to the SPL BSS.
3069 When defined, the linker checks that the actual memory used
3070 by SPL from __bss_start to __bss_end does not exceed it.
3071 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3072 must not be both defined at the same time.
3075 Adress of the start of the stack SPL will use
3077 CONFIG_SPL_RELOC_STACK
3078 Adress of the start of the stack SPL will use after
3079 relocation. If unspecified, this is equal to
3082 CONFIG_SYS_SPL_MALLOC_START
3083 Starting address of the malloc pool used in SPL.
3085 CONFIG_SYS_SPL_MALLOC_SIZE
3086 The size of the malloc pool used in SPL.
3088 CONFIG_SPL_FRAMEWORK
3089 Enable the SPL framework under common/. This framework
3090 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3091 NAND loading of the Linux Kernel.
3093 CONFIG_SPL_DISPLAY_PRINT
3094 For ARM, enable an optional function to print more information
3095 about the running system.
3097 CONFIG_SPL_INIT_MINIMAL
3098 Arch init code should be built for a very small image
3100 CONFIG_SPL_LIBCOMMON_SUPPORT
3101 Support for common/libcommon.o in SPL binary
3103 CONFIG_SPL_LIBDISK_SUPPORT
3104 Support for disk/libdisk.o in SPL binary
3106 CONFIG_SPL_I2C_SUPPORT
3107 Support for drivers/i2c/libi2c.o in SPL binary
3109 CONFIG_SPL_GPIO_SUPPORT
3110 Support for drivers/gpio/libgpio.o in SPL binary
3112 CONFIG_SPL_MMC_SUPPORT
3113 Support for drivers/mmc/libmmc.o in SPL binary
3115 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3116 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3117 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3118 Address, size and partition on the MMC to load U-Boot from
3119 when the MMC is being used in raw mode.
3121 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3122 Sector to load kernel uImage from when MMC is being
3123 used in raw mode (for Falcon mode)
3125 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3126 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3127 Sector and number of sectors to load kernel argument
3128 parameters from when MMC is being used in raw mode
3131 CONFIG_SPL_FAT_SUPPORT
3132 Support for fs/fat/libfat.o in SPL binary
3134 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3135 Filename to read to load U-Boot when reading from FAT
3137 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3138 Filename to read to load kernel uImage when reading
3139 from FAT (for Falcon mode)
3141 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3142 Filename to read to load kernel argument parameters
3143 when reading from FAT (for Falcon mode)
3145 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3146 Set this for NAND SPL on PPC mpc83xx targets, so that
3147 start.S waits for the rest of the SPL to load before
3148 continuing (the hardware starts execution after just
3149 loading the first page rather than the full 4K).
3151 CONFIG_SPL_NAND_BASE
3152 Include nand_base.c in the SPL. Requires
3153 CONFIG_SPL_NAND_DRIVERS.
3155 CONFIG_SPL_NAND_DRIVERS
3156 SPL uses normal NAND drivers, not minimal drivers.
3159 Include standard software ECC in the SPL
3161 CONFIG_SPL_NAND_SIMPLE
3162 Support for NAND boot using simple NAND drivers that
3163 expose the cmd_ctrl() interface.
3165 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3166 Set for the SPL on PPC mpc8xxx targets, support for
3167 arch/powerpc/cpu/mpc8xxx/ddr/libddr.o in SPL binary.
3169 CONFIG_SPL_COMMON_INIT_DDR
3170 Set for common ddr init with serial presence detect in
3173 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3174 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3175 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3176 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3177 CONFIG_SYS_NAND_ECCBYTES
3178 Defines the size and behavior of the NAND that SPL uses
3181 CONFIG_SYS_NAND_U_BOOT_OFFS
3182 Location in NAND to read U-Boot from
3184 CONFIG_SYS_NAND_U_BOOT_DST
3185 Location in memory to load U-Boot to
3187 CONFIG_SYS_NAND_U_BOOT_SIZE
3188 Size of image to load
3190 CONFIG_SYS_NAND_U_BOOT_START
3191 Entry point in loaded image to jump to
3193 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3194 Define this if you need to first read the OOB and then the
3195 data. This is used for example on davinci plattforms.
3197 CONFIG_SPL_OMAP3_ID_NAND
3198 Support for an OMAP3-specific set of functions to return the
3199 ID and MFR of the first attached NAND chip, if present.
3201 CONFIG_SPL_SERIAL_SUPPORT
3202 Support for drivers/serial/libserial.o in SPL binary
3204 CONFIG_SPL_SPI_FLASH_SUPPORT
3205 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3207 CONFIG_SPL_SPI_SUPPORT
3208 Support for drivers/spi/libspi.o in SPL binary
3210 CONFIG_SPL_RAM_DEVICE
3211 Support for running image already present in ram, in SPL binary
3213 CONFIG_SPL_LIBGENERIC_SUPPORT
3214 Support for lib/libgeneric.o in SPL binary
3216 CONFIG_SPL_ENV_SUPPORT
3217 Support for the environment operating in SPL binary
3219 CONFIG_SPL_NET_SUPPORT
3220 Support for the net/libnet.o in SPL binary.
3221 It conflicts with SPL env from storage medium specified by
3222 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3225 Image offset to which the SPL should be padded before appending
3226 the SPL payload. By default, this is defined as
3227 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3228 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3229 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3232 Final target image containing SPL and payload. Some SPLs
3233 use an arch-specific makefile fragment instead, for
3234 example if more than one image needs to be produced.
3236 CONFIG_FIT_SPL_PRINT
3237 Printing information about a FIT image adds quite a bit of
3238 code to SPL. So this is normally disabled in SPL. Use this
3239 option to re-enable it. This will affect the output of the
3240 bootm command when booting a FIT image.
3244 Enable building of TPL globally.
3247 Image offset to which the TPL should be padded before appending
3248 the TPL payload. By default, this is defined as
3249 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3250 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3251 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3256 [so far only for SMDK2400 boards]
3258 - Modem support enable:
3259 CONFIG_MODEM_SUPPORT
3261 - RTS/CTS Flow control enable:
3264 - Modem debug support:
3265 CONFIG_MODEM_SUPPORT_DEBUG
3267 Enables debugging stuff (char screen[1024], dbg())
3268 for modem support. Useful only with BDI2000.
3270 - Interrupt support (PPC):
3272 There are common interrupt_init() and timer_interrupt()
3273 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3274 for CPU specific initialization. interrupt_init_cpu()
3275 should set decrementer_count to appropriate value. If
3276 CPU resets decrementer automatically after interrupt
3277 (ppc4xx) it should set decrementer_count to zero.
3278 timer_interrupt() calls timer_interrupt_cpu() for CPU
3279 specific handling. If board has watchdog / status_led
3280 / other_activity_monitor it works automatically from
3281 general timer_interrupt().
3285 In the target system modem support is enabled when a
3286 specific key (key combination) is pressed during
3287 power-on. Otherwise U-Boot will boot normally
3288 (autoboot). The key_pressed() function is called from
3289 board_init(). Currently key_pressed() is a dummy
3290 function, returning 1 and thus enabling modem
3293 If there are no modem init strings in the
3294 environment, U-Boot proceed to autoboot; the
3295 previous output (banner, info printfs) will be
3298 See also: doc/README.Modem
3300 Board initialization settings:
3301 ------------------------------
3303 During Initialization u-boot calls a number of board specific functions
3304 to allow the preparation of board specific prerequisites, e.g. pin setup
3305 before drivers are initialized. To enable these callbacks the
3306 following configuration macros have to be defined. Currently this is
3307 architecture specific, so please check arch/your_architecture/lib/board.c
3308 typically in board_init_f() and board_init_r().
3310 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3311 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3312 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3313 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3315 Configuration Settings:
3316 -----------------------
3318 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3319 undefine this when you're short of memory.
3321 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3322 width of the commands listed in the 'help' command output.
3324 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3325 prompt for user input.
3327 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3329 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3331 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3333 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3334 the application (usually a Linux kernel) when it is
3337 - CONFIG_SYS_BAUDRATE_TABLE:
3338 List of legal baudrate settings for this board.
3340 - CONFIG_SYS_CONSOLE_INFO_QUIET
3341 Suppress display of console information at boot.
3343 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3344 If the board specific function
3345 extern int overwrite_console (void);
3346 returns 1, the stdin, stderr and stdout are switched to the
3347 serial port, else the settings in the environment are used.
3349 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3350 Enable the call to overwrite_console().
3352 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3353 Enable overwrite of previous console environment settings.
3355 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3356 Begin and End addresses of the area used by the
3359 - CONFIG_SYS_ALT_MEMTEST:
3360 Enable an alternate, more extensive memory test.
3362 - CONFIG_SYS_MEMTEST_SCRATCH:
3363 Scratch address used by the alternate memory test
3364 You only need to set this if address zero isn't writeable
3366 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3367 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3368 this specified memory area will get subtracted from the top
3369 (end) of RAM and won't get "touched" at all by U-Boot. By
3370 fixing up gd->ram_size the Linux kernel should gets passed
3371 the now "corrected" memory size and won't touch it either.
3372 This should work for arch/ppc and arch/powerpc. Only Linux
3373 board ports in arch/powerpc with bootwrapper support that
3374 recalculate the memory size from the SDRAM controller setup
3375 will have to get fixed in Linux additionally.
3377 This option can be used as a workaround for the 440EPx/GRx
3378 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3381 WARNING: Please make sure that this value is a multiple of
3382 the Linux page size (normally 4k). If this is not the case,
3383 then the end address of the Linux memory will be located at a
3384 non page size aligned address and this could cause major
3387 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3388 Enable temporary baudrate change while serial download
3390 - CONFIG_SYS_SDRAM_BASE:
3391 Physical start address of SDRAM. _Must_ be 0 here.
3393 - CONFIG_SYS_MBIO_BASE:
3394 Physical start address of Motherboard I/O (if using a
3397 - CONFIG_SYS_FLASH_BASE:
3398 Physical start address of Flash memory.
3400 - CONFIG_SYS_MONITOR_BASE:
3401 Physical start address of boot monitor code (set by
3402 make config files to be same as the text base address
3403 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3404 CONFIG_SYS_FLASH_BASE when booting from flash.
3406 - CONFIG_SYS_MONITOR_LEN:
3407 Size of memory reserved for monitor code, used to
3408 determine _at_compile_time_ (!) if the environment is
3409 embedded within the U-Boot image, or in a separate
3412 - CONFIG_SYS_MALLOC_LEN:
3413 Size of DRAM reserved for malloc() use.
3415 - CONFIG_SYS_BOOTM_LEN:
3416 Normally compressed uImages are limited to an
3417 uncompressed size of 8 MBytes. If this is not enough,
3418 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3419 to adjust this setting to your needs.
3421 - CONFIG_SYS_BOOTMAPSZ:
3422 Maximum size of memory mapped by the startup code of
3423 the Linux kernel; all data that must be processed by
3424 the Linux kernel (bd_info, boot arguments, FDT blob if
3425 used) must be put below this limit, unless "bootm_low"
3426 environment variable is defined and non-zero. In such case
3427 all data for the Linux kernel must be between "bootm_low"
3428 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3429 variable "bootm_mapsize" will override the value of
3430 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3431 then the value in "bootm_size" will be used instead.
3433 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3434 Enable initrd_high functionality. If defined then the
3435 initrd_high feature is enabled and the bootm ramdisk subcommand
3438 - CONFIG_SYS_BOOT_GET_CMDLINE:
3439 Enables allocating and saving kernel cmdline in space between
3440 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3442 - CONFIG_SYS_BOOT_GET_KBD:
3443 Enables allocating and saving a kernel copy of the bd_info in
3444 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3446 - CONFIG_SYS_MAX_FLASH_BANKS:
3447 Max number of Flash memory banks
3449 - CONFIG_SYS_MAX_FLASH_SECT:
3450 Max number of sectors on a Flash chip
3452 - CONFIG_SYS_FLASH_ERASE_TOUT:
3453 Timeout for Flash erase operations (in ms)
3455 - CONFIG_SYS_FLASH_WRITE_TOUT:
3456 Timeout for Flash write operations (in ms)
3458 - CONFIG_SYS_FLASH_LOCK_TOUT
3459 Timeout for Flash set sector lock bit operation (in ms)
3461 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3462 Timeout for Flash clear lock bits operation (in ms)
3464 - CONFIG_SYS_FLASH_PROTECTION
3465 If defined, hardware flash sectors protection is used
3466 instead of U-Boot software protection.
3468 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3470 Enable TFTP transfers directly to flash memory;
3471 without this option such a download has to be
3472 performed in two steps: (1) download to RAM, and (2)
3473 copy from RAM to flash.
3475 The two-step approach is usually more reliable, since
3476 you can check if the download worked before you erase
3477 the flash, but in some situations (when system RAM is
3478 too limited to allow for a temporary copy of the
3479 downloaded image) this option may be very useful.
3481 - CONFIG_SYS_FLASH_CFI:
3482 Define if the flash driver uses extra elements in the
3483 common flash structure for storing flash geometry.
3485 - CONFIG_FLASH_CFI_DRIVER
3486 This option also enables the building of the cfi_flash driver
3487 in the drivers directory
3489 - CONFIG_FLASH_CFI_MTD
3490 This option enables the building of the cfi_mtd driver
3491 in the drivers directory. The driver exports CFI flash
3494 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3495 Use buffered writes to flash.
3497 - CONFIG_FLASH_SPANSION_S29WS_N
3498 s29ws-n MirrorBit flash has non-standard addresses for buffered
3501 - CONFIG_SYS_FLASH_QUIET_TEST
3502 If this option is defined, the common CFI flash doesn't
3503 print it's warning upon not recognized FLASH banks. This
3504 is useful, if some of the configured banks are only
3505 optionally available.
3507 - CONFIG_FLASH_SHOW_PROGRESS
3508 If defined (must be an integer), print out countdown
3509 digits and dots. Recommended value: 45 (9..1) for 80
3510 column displays, 15 (3..1) for 40 column displays.
3512 - CONFIG_FLASH_VERIFY
3513 If defined, the content of the flash (destination) is compared
3514 against the source after the write operation. An error message
3515 will be printed when the contents are not identical.
3516 Please note that this option is useless in nearly all cases,
3517 since such flash programming errors usually are detected earlier
3518 while unprotecting/erasing/programming. Please only enable
3519 this option if you really know what you are doing.
3521 - CONFIG_SYS_RX_ETH_BUFFER:
3522 Defines the number of Ethernet receive buffers. On some
3523 Ethernet controllers it is recommended to set this value
3524 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3525 buffers can be full shortly after enabling the interface
3526 on high Ethernet traffic.
3527 Defaults to 4 if not defined.
3529 - CONFIG_ENV_MAX_ENTRIES
3531 Maximum number of entries in the hash table that is used
3532 internally to store the environment settings. The default
3533 setting is supposed to be generous and should work in most
3534 cases. This setting can be used to tune behaviour; see
3535 lib/hashtable.c for details.
3537 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3538 - CONFIG_ENV_FLAGS_LIST_STATIC
3539 Enable validation of the values given to environment variables when
3540 calling env set. Variables can be restricted to only decimal,
3541 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3542 the variables can also be restricted to IP address or MAC address.
3544 The format of the list is:
3545 type_attribute = [s|d|x|b|i|m]
3546 access_atribute = [a|r|o|c]
3547 attributes = type_attribute[access_atribute]
3548 entry = variable_name[:attributes]
3551 The type attributes are:
3552 s - String (default)
3555 b - Boolean ([1yYtT|0nNfF])
3559 The access attributes are:
3565 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3566 Define this to a list (string) to define the ".flags"
3567 envirnoment variable in the default or embedded environment.
3569 - CONFIG_ENV_FLAGS_LIST_STATIC
3570 Define this to a list (string) to define validation that
3571 should be done if an entry is not found in the ".flags"
3572 environment variable. To override a setting in the static
3573 list, simply add an entry for the same variable name to the
3576 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3577 If defined, don't allow the -f switch to env set override variable
3580 - CONFIG_SYS_GENERIC_BOARD
3581 This selects the architecture-generic board system instead of the
3582 architecture-specific board files. It is intended to move boards
3583 to this new framework over time. Defining this will disable the
3584 arch/foo/lib/board.c file and use common/board_f.c and
3585 common/board_r.c instead. To use this option your architecture
3586 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3587 its config.mk file). If you find problems enabling this option on
3588 your board please report the problem and send patches!
3590 - CONFIG_SYS_SYM_OFFSETS
3591 This is set by architectures that use offsets for link symbols
3592 instead of absolute values. So bss_start is obtained using an
3593 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3594 directly. You should not need to touch this setting.
3596 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3597 This is set by OMAP boards for the max time that reset should
3598 be asserted. See doc/README.omap-reset-time for details on how
3599 the value can be calulated on a given board.
3601 The following definitions that deal with the placement and management
3602 of environment data (variable area); in general, we support the
3603 following configurations:
3605 - CONFIG_BUILD_ENVCRC:
3607 Builds up envcrc with the target environment so that external utils
3608 may easily extract it and embed it in final U-Boot images.
3610 - CONFIG_ENV_IS_IN_FLASH:
3612 Define this if the environment is in flash memory.
3614 a) The environment occupies one whole flash sector, which is
3615 "embedded" in the text segment with the U-Boot code. This
3616 happens usually with "bottom boot sector" or "top boot
3617 sector" type flash chips, which have several smaller
3618 sectors at the start or the end. For instance, such a
3619 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3620 such a case you would place the environment in one of the
3621 4 kB sectors - with U-Boot code before and after it. With
3622 "top boot sector" type flash chips, you would put the
3623 environment in one of the last sectors, leaving a gap
3624 between U-Boot and the environment.
3626 - CONFIG_ENV_OFFSET:
3628 Offset of environment data (variable area) to the
3629 beginning of flash memory; for instance, with bottom boot
3630 type flash chips the second sector can be used: the offset
3631 for this sector is given here.
3633 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3637 This is just another way to specify the start address of
3638 the flash sector containing the environment (instead of
3641 - CONFIG_ENV_SECT_SIZE:
3643 Size of the sector containing the environment.
3646 b) Sometimes flash chips have few, equal sized, BIG sectors.
3647 In such a case you don't want to spend a whole sector for
3652 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3653 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3654 of this flash sector for the environment. This saves
3655 memory for the RAM copy of the environment.
3657 It may also save flash memory if you decide to use this
3658 when your environment is "embedded" within U-Boot code,
3659 since then the remainder of the flash sector could be used
3660 for U-Boot code. It should be pointed out that this is
3661 STRONGLY DISCOURAGED from a robustness point of view:
3662 updating the environment in flash makes it always
3663 necessary to erase the WHOLE sector. If something goes
3664 wrong before the contents has been restored from a copy in
3665 RAM, your target system will be dead.
3667 - CONFIG_ENV_ADDR_REDUND
3668 CONFIG_ENV_SIZE_REDUND
3670 These settings describe a second storage area used to hold
3671 a redundant copy of the environment data, so that there is
3672 a valid backup copy in case there is a power failure during
3673 a "saveenv" operation.
3675 BE CAREFUL! Any changes to the flash layout, and some changes to the
3676 source code will make it necessary to adapt <board>/u-boot.lds*
3680 - CONFIG_ENV_IS_IN_NVRAM:
3682 Define this if you have some non-volatile memory device
3683 (NVRAM, battery buffered SRAM) which you want to use for the
3689 These two #defines are used to determine the memory area you
3690 want to use for environment. It is assumed that this memory
3691 can just be read and written to, without any special
3694 BE CAREFUL! The first access to the environment happens quite early
3695 in U-Boot initalization (when we try to get the setting of for the
3696 console baudrate). You *MUST* have mapped your NVRAM area then, or
3699 Please note that even with NVRAM we still use a copy of the
3700 environment in RAM: we could work on NVRAM directly, but we want to
3701 keep settings there always unmodified except somebody uses "saveenv"
3702 to save the current settings.
3705 - CONFIG_ENV_IS_IN_EEPROM:
3707 Use this if you have an EEPROM or similar serial access
3708 device and a driver for it.
3710 - CONFIG_ENV_OFFSET:
3713 These two #defines specify the offset and size of the
3714 environment area within the total memory of your EEPROM.
3716 - CONFIG_SYS_I2C_EEPROM_ADDR:
3717 If defined, specified the chip address of the EEPROM device.
3718 The default address is zero.
3720 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3721 If defined, the number of bits used to address bytes in a
3722 single page in the EEPROM device. A 64 byte page, for example
3723 would require six bits.
3725 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3726 If defined, the number of milliseconds to delay between
3727 page writes. The default is zero milliseconds.
3729 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3730 The length in bytes of the EEPROM memory array address. Note
3731 that this is NOT the chip address length!
3733 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3734 EEPROM chips that implement "address overflow" are ones
3735 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3736 address and the extra bits end up in the "chip address" bit
3737 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3740 Note that we consider the length of the address field to
3741 still be one byte because the extra address bits are hidden
3742 in the chip address.
3744 - CONFIG_SYS_EEPROM_SIZE:
3745 The size in bytes of the EEPROM device.
3747 - CONFIG_ENV_EEPROM_IS_ON_I2C
3748 define this, if you have I2C and SPI activated, and your
3749 EEPROM, which holds the environment, is on the I2C bus.
3751 - CONFIG_I2C_ENV_EEPROM_BUS
3752 if you have an Environment on an EEPROM reached over
3753 I2C muxes, you can define here, how to reach this
3754 EEPROM. For example:
3756 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3758 EEPROM which holds the environment, is reached over
3759 a pca9547 i2c mux with address 0x70, channel 3.
3761 - CONFIG_ENV_IS_IN_DATAFLASH:
3763 Define this if you have a DataFlash memory device which you
3764 want to use for the environment.
3766 - CONFIG_ENV_OFFSET:
3770 These three #defines specify the offset and size of the
3771 environment area within the total memory of your DataFlash placed
3772 at the specified address.
3774 - CONFIG_ENV_IS_IN_REMOTE:
3776 Define this if you have a remote memory space which you
3777 want to use for the local device's environment.
3782 These two #defines specify the address and size of the
3783 environment area within the remote memory space. The
3784 local device can get the environment from remote memory
3785 space by SRIO or PCIE links.
3787 BE CAREFUL! For some special cases, the local device can not use
3788 "saveenv" command. For example, the local device will get the
3789 environment stored in a remote NOR flash by SRIO or PCIE link,
3790 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3792 - CONFIG_ENV_IS_IN_NAND:
3794 Define this if you have a NAND device which you want to use
3795 for the environment.
3797 - CONFIG_ENV_OFFSET:
3800 These two #defines specify the offset and size of the environment
3801 area within the first NAND device. CONFIG_ENV_OFFSET must be
3802 aligned to an erase block boundary.
3804 - CONFIG_ENV_OFFSET_REDUND (optional):
3806 This setting describes a second storage area of CONFIG_ENV_SIZE
3807 size used to hold a redundant copy of the environment data, so
3808 that there is a valid backup copy in case there is a power failure
3809 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3810 aligned to an erase block boundary.
3812 - CONFIG_ENV_RANGE (optional):
3814 Specifies the length of the region in which the environment
3815 can be written. This should be a multiple of the NAND device's
3816 block size. Specifying a range with more erase blocks than
3817 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3818 the range to be avoided.
3820 - CONFIG_ENV_OFFSET_OOB (optional):
3822 Enables support for dynamically retrieving the offset of the
3823 environment from block zero's out-of-band data. The
3824 "nand env.oob" command can be used to record this offset.
3825 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3826 using CONFIG_ENV_OFFSET_OOB.
3828 - CONFIG_NAND_ENV_DST
3830 Defines address in RAM to which the nand_spl code should copy the
3831 environment. If redundant environment is used, it will be copied to
3832 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3834 - CONFIG_ENV_IS_IN_UBI:
3836 Define this if you have an UBI volume that you want to use for the
3837 environment. This has the benefit of wear-leveling the environment
3838 accesses, which is important on NAND.
3840 - CONFIG_ENV_UBI_PART:
3842 Define this to a string that is the mtd partition containing the UBI.
3844 - CONFIG_ENV_UBI_VOLUME:
3846 Define this to the name of the volume that you want to store the
3849 - CONFIG_ENV_UBI_VOLUME_REDUND:
3851 Define this to the name of another volume to store a second copy of
3852 the environment in. This will enable redundant environments in UBI.
3853 It is assumed that both volumes are in the same MTD partition.
3855 - CONFIG_UBI_SILENCE_MSG
3856 - CONFIG_UBIFS_SILENCE_MSG
3858 You will probably want to define these to avoid a really noisy system
3859 when storing the env in UBI.
3861 - CONFIG_ENV_IS_IN_MMC:
3863 Define this if you have an MMC device which you want to use for the
3866 - CONFIG_SYS_MMC_ENV_DEV:
3868 Specifies which MMC device the environment is stored in.
3870 - CONFIG_SYS_MMC_ENV_PART (optional):
3872 Specifies which MMC partition the environment is stored in. If not
3873 set, defaults to partition 0, the user area. Common values might be
3874 1 (first MMC boot partition), 2 (second MMC boot partition).
3876 - CONFIG_ENV_OFFSET:
3879 These two #defines specify the offset and size of the environment
3880 area within the specified MMC device.
3882 If offset is positive (the usual case), it is treated as relative to
3883 the start of the MMC partition. If offset is negative, it is treated
3884 as relative to the end of the MMC partition. This can be useful if
3885 your board may be fitted with different MMC devices, which have
3886 different sizes for the MMC partitions, and you always want the
3887 environment placed at the very end of the partition, to leave the
3888 maximum possible space before it, to store other data.
3890 These two values are in units of bytes, but must be aligned to an
3891 MMC sector boundary.
3893 - CONFIG_ENV_OFFSET_REDUND (optional):
3895 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3896 hold a redundant copy of the environment data. This provides a
3897 valid backup copy in case the other copy is corrupted, e.g. due
3898 to a power failure during a "saveenv" operation.
3900 This value may also be positive or negative; this is handled in the
3901 same way as CONFIG_ENV_OFFSET.
3903 This value is also in units of bytes, but must also be aligned to
3904 an MMC sector boundary.
3906 - CONFIG_ENV_SIZE_REDUND (optional):
3908 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3909 set. If this value is set, it must be set to the same value as
3912 - CONFIG_SYS_SPI_INIT_OFFSET
3914 Defines offset to the initial SPI buffer area in DPRAM. The
3915 area is used at an early stage (ROM part) if the environment
3916 is configured to reside in the SPI EEPROM: We need a 520 byte
3917 scratch DPRAM area. It is used between the two initialization
3918 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3919 to be a good choice since it makes it far enough from the
3920 start of the data area as well as from the stack pointer.
3922 Please note that the environment is read-only until the monitor
3923 has been relocated to RAM and a RAM copy of the environment has been
3924 created; also, when using EEPROM you will have to use getenv_f()
3925 until then to read environment variables.
3927 The environment is protected by a CRC32 checksum. Before the monitor
3928 is relocated into RAM, as a result of a bad CRC you will be working
3929 with the compiled-in default environment - *silently*!!! [This is
3930 necessary, because the first environment variable we need is the
3931 "baudrate" setting for the console - if we have a bad CRC, we don't
3932 have any device yet where we could complain.]
3934 Note: once the monitor has been relocated, then it will complain if
3935 the default environment is used; a new CRC is computed as soon as you
3936 use the "saveenv" command to store a valid environment.
3938 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3939 Echo the inverted Ethernet link state to the fault LED.
3941 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3942 also needs to be defined.
3944 - CONFIG_SYS_FAULT_MII_ADDR:
3945 MII address of the PHY to check for the Ethernet link state.
3947 - CONFIG_NS16550_MIN_FUNCTIONS:
3948 Define this if you desire to only have use of the NS16550_init
3949 and NS16550_putc functions for the serial driver located at
3950 drivers/serial/ns16550.c. This option is useful for saving
3951 space for already greatly restricted images, including but not
3952 limited to NAND_SPL configurations.
3954 - CONFIG_DISPLAY_BOARDINFO
3955 Display information about the board that U-Boot is running on
3956 when U-Boot starts up. The board function checkboard() is called
3959 - CONFIG_DISPLAY_BOARDINFO_LATE
3960 Similar to the previous option, but display this information
3961 later, once stdio is running and output goes to the LCD, if
3964 Low Level (hardware related) configuration options:
3965 ---------------------------------------------------
3967 - CONFIG_SYS_CACHELINE_SIZE:
3968 Cache Line Size of the CPU.
3970 - CONFIG_SYS_DEFAULT_IMMR:
3971 Default address of the IMMR after system reset.
3973 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3974 and RPXsuper) to be able to adjust the position of
3975 the IMMR register after a reset.
3977 - CONFIG_SYS_CCSRBAR_DEFAULT:
3978 Default (power-on reset) physical address of CCSR on Freescale
3981 - CONFIG_SYS_CCSRBAR:
3982 Virtual address of CCSR. On a 32-bit build, this is typically
3983 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3985 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3986 for cross-platform code that uses that macro instead.
3988 - CONFIG_SYS_CCSRBAR_PHYS:
3989 Physical address of CCSR. CCSR can be relocated to a new
3990 physical address, if desired. In this case, this macro should
3991 be set to that address. Otherwise, it should be set to the
3992 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3993 is typically relocated on 36-bit builds. It is recommended
3994 that this macro be defined via the _HIGH and _LOW macros:
3996 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3997 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3999 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4000 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4001 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4002 used in assembly code, so it must not contain typecasts or
4003 integer size suffixes (e.g. "ULL").
4005 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4006 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4007 used in assembly code, so it must not contain typecasts or
4008 integer size suffixes (e.g. "ULL").
4010 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4011 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4012 forced to a value that ensures that CCSR is not relocated.
4014 - Floppy Disk Support:
4015 CONFIG_SYS_FDC_DRIVE_NUMBER
4017 the default drive number (default value 0)
4019 CONFIG_SYS_ISA_IO_STRIDE
4021 defines the spacing between FDC chipset registers
4024 CONFIG_SYS_ISA_IO_OFFSET
4026 defines the offset of register from address. It
4027 depends on which part of the data bus is connected to
4028 the FDC chipset. (default value 0)
4030 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4031 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4034 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4035 fdc_hw_init() is called at the beginning of the FDC
4036 setup. fdc_hw_init() must be provided by the board
4037 source code. It is used to make hardware dependant
4041 Most IDE controllers were designed to be connected with PCI
4042 interface. Only few of them were designed for AHB interface.
4043 When software is doing ATA command and data transfer to
4044 IDE devices through IDE-AHB controller, some additional
4045 registers accessing to these kind of IDE-AHB controller
4048 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4049 DO NOT CHANGE unless you know exactly what you're
4050 doing! (11-4) [MPC8xx/82xx systems only]
4052 - CONFIG_SYS_INIT_RAM_ADDR:
4054 Start address of memory area that can be used for
4055 initial data and stack; please note that this must be
4056 writable memory that is working WITHOUT special
4057 initialization, i. e. you CANNOT use normal RAM which
4058 will become available only after programming the
4059 memory controller and running certain initialization
4062 U-Boot uses the following memory types:
4063 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4064 - MPC824X: data cache
4065 - PPC4xx: data cache
4067 - CONFIG_SYS_GBL_DATA_OFFSET:
4069 Offset of the initial data structure in the memory
4070 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4071 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4072 data is located at the end of the available space
4073 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4074 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4075 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4076 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4079 On the MPC824X (or other systems that use the data
4080 cache for initial memory) the address chosen for
4081 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4082 point to an otherwise UNUSED address space between
4083 the top of RAM and the start of the PCI space.
4085 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4087 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4089 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4091 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4093 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4095 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4097 - CONFIG_SYS_OR_TIMING_SDRAM:
4100 - CONFIG_SYS_MAMR_PTA:
4101 periodic timer for refresh
4103 - CONFIG_SYS_DER: Debug Event Register (37-47)
4105 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4106 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4107 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4108 CONFIG_SYS_BR1_PRELIM:
4109 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4111 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4112 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4113 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4114 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4116 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4117 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4118 Machine Mode Register and Memory Periodic Timer
4119 Prescaler definitions (SDRAM timing)
4121 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4122 enable I2C microcode relocation patch (MPC8xx);
4123 define relocation offset in DPRAM [DSP2]
4125 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4126 enable SMC microcode relocation patch (MPC8xx);
4127 define relocation offset in DPRAM [SMC1]
4129 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4130 enable SPI microcode relocation patch (MPC8xx);
4131 define relocation offset in DPRAM [SCC4]
4133 - CONFIG_SYS_USE_OSCCLK:
4134 Use OSCM clock mode on MBX8xx board. Be careful,
4135 wrong setting might damage your board. Read
4136 doc/README.MBX before setting this variable!
4138 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4139 Offset of the bootmode word in DPRAM used by post
4140 (Power On Self Tests). This definition overrides
4141 #define'd default value in commproc.h resp.
4144 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4145 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4146 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4147 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4148 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4149 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4150 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4151 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4152 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4154 - CONFIG_PCI_DISABLE_PCIE:
4155 Disable PCI-Express on systems where it is supported but not
4158 - CONFIG_PCI_ENUM_ONLY
4159 Only scan through and get the devices on the busses.
4160 Don't do any setup work, presumably because someone or
4161 something has already done it, and we don't need to do it
4162 a second time. Useful for platforms that are pre-booted
4163 by coreboot or similar.
4165 - CONFIG_PCI_INDIRECT_BRIDGE:
4166 Enable support for indirect PCI bridges.
4169 Chip has SRIO or not
4172 Board has SRIO 1 port available
4175 Board has SRIO 2 port available
4177 - CONFIG_SRIO_PCIE_BOOT_MASTER
4178 Board can support master function for Boot from SRIO and PCIE
4180 - CONFIG_SYS_SRIOn_MEM_VIRT:
4181 Virtual Address of SRIO port 'n' memory region
4183 - CONFIG_SYS_SRIOn_MEM_PHYS:
4184 Physical Address of SRIO port 'n' memory region
4186 - CONFIG_SYS_SRIOn_MEM_SIZE:
4187 Size of SRIO port 'n' memory region
4189 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4190 Defined to tell the NAND controller that the NAND chip is using
4192 Not all NAND drivers use this symbol.
4193 Example of drivers that use it:
4194 - drivers/mtd/nand/ndfc.c
4195 - drivers/mtd/nand/mxc_nand.c
4197 - CONFIG_SYS_NDFC_EBC0_CFG
4198 Sets the EBC0_CFG register for the NDFC. If not defined
4199 a default value will be used.
4202 Get DDR timing information from an I2C EEPROM. Common
4203 with pluggable memory modules such as SODIMMs
4206 I2C address of the SPD EEPROM
4208 - CONFIG_SYS_SPD_BUS_NUM
4209 If SPD EEPROM is on an I2C bus other than the first
4210 one, specify here. Note that the value must resolve
4211 to something your driver can deal with.
4213 - CONFIG_SYS_DDR_RAW_TIMING
4214 Get DDR timing information from other than SPD. Common with
4215 soldered DDR chips onboard without SPD. DDR raw timing
4216 parameters are extracted from datasheet and hard-coded into
4217 header files or board specific files.
4219 - CONFIG_FSL_DDR_INTERACTIVE
4220 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4222 - CONFIG_SYS_83XX_DDR_USES_CS0
4223 Only for 83xx systems. If specified, then DDR should
4224 be configured using CS0 and CS1 instead of CS2 and CS3.
4226 - CONFIG_ETHER_ON_FEC[12]
4227 Define to enable FEC[12] on a 8xx series processor.
4229 - CONFIG_FEC[12]_PHY
4230 Define to the hardcoded PHY address which corresponds
4231 to the given FEC; i. e.
4232 #define CONFIG_FEC1_PHY 4
4233 means that the PHY with address 4 is connected to FEC1
4235 When set to -1, means to probe for first available.
4237 - CONFIG_FEC[12]_PHY_NORXERR
4238 The PHY does not have a RXERR line (RMII only).
4239 (so program the FEC to ignore it).
4242 Enable RMII mode for all FECs.
4243 Note that this is a global option, we can't
4244 have one FEC in standard MII mode and another in RMII mode.
4246 - CONFIG_CRC32_VERIFY
4247 Add a verify option to the crc32 command.
4250 => crc32 -v <address> <count> <crc32>
4252 Where address/count indicate a memory area
4253 and crc32 is the correct crc32 which the
4257 Add the "loopw" memory command. This only takes effect if
4258 the memory commands are activated globally (CONFIG_CMD_MEM).
4261 Add the "mdc" and "mwc" memory commands. These are cyclic
4266 This command will print 4 bytes (10,11,12,13) each 500 ms.
4268 => mwc.l 100 12345678 10
4269 This command will write 12345678 to address 100 all 10 ms.
4271 This only takes effect if the memory commands are activated
4272 globally (CONFIG_CMD_MEM).
4274 - CONFIG_SKIP_LOWLEVEL_INIT
4275 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4276 low level initializations (like setting up the memory
4277 controller) are omitted and/or U-Boot does not
4278 relocate itself into RAM.
4280 Normally this variable MUST NOT be defined. The only
4281 exception is when U-Boot is loaded (to RAM) by some
4282 other boot loader or by a debugger which performs
4283 these initializations itself.
4286 Modifies the behaviour of start.S when compiling a loader
4287 that is executed before the actual U-Boot. E.g. when
4288 compiling a NAND SPL.
4291 Modifies the behaviour of start.S when compiling a loader
4292 that is executed after the SPL and before the actual U-Boot.
4293 It is loaded by the SPL.
4295 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4296 Only for 85xx systems. If this variable is specified, the section
4297 .resetvec is not kept and the section .bootpg is placed in the
4298 previous 4k of the .text section.
4300 - CONFIG_ARCH_MAP_SYSMEM
4301 Generally U-Boot (and in particular the md command) uses
4302 effective address. It is therefore not necessary to regard
4303 U-Boot address as virtual addresses that need to be translated
4304 to physical addresses. However, sandbox requires this, since
4305 it maintains its own little RAM buffer which contains all
4306 addressable memory. This option causes some memory accesses
4307 to be mapped through map_sysmem() / unmap_sysmem().
4309 - CONFIG_USE_ARCH_MEMCPY
4310 CONFIG_USE_ARCH_MEMSET
4311 If these options are used a optimized version of memcpy/memset will
4312 be used if available. These functions may be faster under some
4313 conditions but may increase the binary size.
4315 - CONFIG_X86_RESET_VECTOR
4316 If defined, the x86 reset vector code is included. This is not
4317 needed when U-Boot is running from Coreboot.
4320 Defines the MPU clock speed (in MHz).
4322 NOTE : currently only supported on AM335x platforms.
4324 Freescale QE/FMAN Firmware Support:
4325 -----------------------------------
4327 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4328 loading of "firmware", which is encoded in the QE firmware binary format.
4329 This firmware often needs to be loaded during U-Boot booting, so macros
4330 are used to identify the storage device (NOR flash, SPI, etc) and the address
4333 - CONFIG_SYS_QE_FMAN_FW_ADDR
4334 The address in the storage device where the firmware is located. The
4335 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4338 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4339 The maximum possible size of the firmware. The firmware binary format
4340 has a field that specifies the actual size of the firmware, but it
4341 might not be possible to read any part of the firmware unless some
4342 local storage is allocated to hold the entire firmware first.
4344 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4345 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4346 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4347 virtual address in NOR flash.
4349 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4350 Specifies that QE/FMAN firmware is located in NAND flash.
4351 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4353 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4354 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4355 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4357 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4358 Specifies that QE/FMAN firmware is located on the primary SPI
4359 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4361 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4362 Specifies that QE/FMAN firmware is located in the remote (master)
4363 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4364 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4365 window->master inbound window->master LAW->the ucode address in
4366 master's memory space.
4368 Building the Software:
4369 ======================
4371 Building U-Boot has been tested in several native build environments
4372 and in many different cross environments. Of course we cannot support
4373 all possibly existing versions of cross development tools in all
4374 (potentially obsolete) versions. In case of tool chain problems we
4375 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4376 which is extensively used to build and test U-Boot.
4378 If you are not using a native environment, it is assumed that you
4379 have GNU cross compiling tools available in your path. In this case,
4380 you must set the environment variable CROSS_COMPILE in your shell.
4381 Note that no changes to the Makefile or any other source files are
4382 necessary. For example using the ELDK on a 4xx CPU, please enter:
4384 $ CROSS_COMPILE=ppc_4xx-
4385 $ export CROSS_COMPILE
4387 Note: If you wish to generate Windows versions of the utilities in
4388 the tools directory you can use the MinGW toolchain
4389 (http://www.mingw.org). Set your HOST tools to the MinGW
4390 toolchain and execute 'make tools'. For example:
4392 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4394 Binaries such as tools/mkimage.exe will be created which can
4395 be executed on computers running Windows.
4397 U-Boot is intended to be simple to build. After installing the
4398 sources you must configure U-Boot for one specific board type. This
4403 where "NAME_config" is the name of one of the existing configu-
4404 rations; see boards.cfg for supported names.
4406 Note: for some board special configuration names may exist; check if
4407 additional information is available from the board vendor; for
4408 instance, the TQM823L systems are available without (standard)
4409 or with LCD support. You can select such additional "features"
4410 when choosing the configuration, i. e.
4413 - will configure for a plain TQM823L, i. e. no LCD support
4415 make TQM823L_LCD_config
4416 - will configure for a TQM823L with U-Boot console on LCD
4421 Finally, type "make all", and you should get some working U-Boot
4422 images ready for download to / installation on your system:
4424 - "u-boot.bin" is a raw binary image
4425 - "u-boot" is an image in ELF binary format
4426 - "u-boot.srec" is in Motorola S-Record format
4428 By default the build is performed locally and the objects are saved
4429 in the source directory. One of the two methods can be used to change
4430 this behavior and build U-Boot to some external directory:
4432 1. Add O= to the make command line invocations:
4434 make O=/tmp/build distclean
4435 make O=/tmp/build NAME_config
4436 make O=/tmp/build all
4438 2. Set environment variable BUILD_DIR to point to the desired location:
4440 export BUILD_DIR=/tmp/build
4445 Note that the command line "O=" setting overrides the BUILD_DIR environment
4449 Please be aware that the Makefiles assume you are using GNU make, so
4450 for instance on NetBSD you might need to use "gmake" instead of
4454 If the system board that you have is not listed, then you will need
4455 to port U-Boot to your hardware platform. To do this, follow these
4458 1. Add a new configuration option for your board to the toplevel
4459 "boards.cfg" file, using the existing entries as examples.
4460 Follow the instructions there to keep the boards in order.
4461 2. Create a new directory to hold your board specific code. Add any
4462 files you need. In your board directory, you will need at least
4463 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4464 3. Create a new configuration file "include/configs/<board>.h" for
4466 3. If you're porting U-Boot to a new CPU, then also create a new
4467 directory to hold your CPU specific code. Add any files you need.
4468 4. Run "make <board>_config" with your new name.
4469 5. Type "make", and you should get a working "u-boot.srec" file
4470 to be installed on your target system.
4471 6. Debug and solve any problems that might arise.
4472 [Of course, this last step is much harder than it sounds.]
4475 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4476 ==============================================================
4478 If you have modified U-Boot sources (for instance added a new board
4479 or support for new devices, a new CPU, etc.) you are expected to
4480 provide feedback to the other developers. The feedback normally takes
4481 the form of a "patch", i. e. a context diff against a certain (latest
4482 official or latest in the git repository) version of U-Boot sources.
4484 But before you submit such a patch, please verify that your modifi-
4485 cation did not break existing code. At least make sure that *ALL* of
4486 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4487 just run the "MAKEALL" script, which will configure and build U-Boot
4488 for ALL supported system. Be warned, this will take a while. You can
4489 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4490 environment variable to the script, i. e. to use the ELDK cross tools
4493 CROSS_COMPILE=ppc_8xx- MAKEALL
4495 or to build on a native PowerPC system you can type
4497 CROSS_COMPILE=' ' MAKEALL
4499 When using the MAKEALL script, the default behaviour is to build
4500 U-Boot in the source directory. This location can be changed by
4501 setting the BUILD_DIR environment variable. Also, for each target
4502 built, the MAKEALL script saves two log files (<target>.ERR and
4503 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4504 location can be changed by setting the MAKEALL_LOGDIR environment
4505 variable. For example:
4507 export BUILD_DIR=/tmp/build
4508 export MAKEALL_LOGDIR=/tmp/log
4509 CROSS_COMPILE=ppc_8xx- MAKEALL
4511 With the above settings build objects are saved in the /tmp/build,
4512 log files are saved in the /tmp/log and the source tree remains clean
4513 during the whole build process.
4516 See also "U-Boot Porting Guide" below.
4519 Monitor Commands - Overview:
4520 ============================
4522 go - start application at address 'addr'
4523 run - run commands in an environment variable
4524 bootm - boot application image from memory
4525 bootp - boot image via network using BootP/TFTP protocol
4526 bootz - boot zImage from memory
4527 tftpboot- boot image via network using TFTP protocol
4528 and env variables "ipaddr" and "serverip"
4529 (and eventually "gatewayip")
4530 tftpput - upload a file via network using TFTP protocol
4531 rarpboot- boot image via network using RARP/TFTP protocol
4532 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4533 loads - load S-Record file over serial line
4534 loadb - load binary file over serial line (kermit mode)
4536 mm - memory modify (auto-incrementing)
4537 nm - memory modify (constant address)
4538 mw - memory write (fill)
4540 cmp - memory compare
4541 crc32 - checksum calculation
4542 i2c - I2C sub-system
4543 sspi - SPI utility commands
4544 base - print or set address offset
4545 printenv- print environment variables
4546 setenv - set environment variables
4547 saveenv - save environment variables to persistent storage
4548 protect - enable or disable FLASH write protection
4549 erase - erase FLASH memory
4550 flinfo - print FLASH memory information
4551 nand - NAND memory operations (see doc/README.nand)
4552 bdinfo - print Board Info structure
4553 iminfo - print header information for application image
4554 coninfo - print console devices and informations
4555 ide - IDE sub-system
4556 loop - infinite loop on address range
4557 loopw - infinite write loop on address range
4558 mtest - simple RAM test
4559 icache - enable or disable instruction cache
4560 dcache - enable or disable data cache
4561 reset - Perform RESET of the CPU
4562 echo - echo args to console
4563 version - print monitor version
4564 help - print online help
4565 ? - alias for 'help'
4568 Monitor Commands - Detailed Description:
4569 ========================================
4573 For now: just type "help <command>".
4576 Environment Variables:
4577 ======================
4579 U-Boot supports user configuration using Environment Variables which
4580 can be made persistent by saving to Flash memory.
4582 Environment Variables are set using "setenv", printed using
4583 "printenv", and saved to Flash using "saveenv". Using "setenv"
4584 without a value can be used to delete a variable from the
4585 environment. As long as you don't save the environment you are
4586 working with an in-memory copy. In case the Flash area containing the
4587 environment is erased by accident, a default environment is provided.
4589 Some configuration options can be set using Environment Variables.
4591 List of environment variables (most likely not complete):
4593 baudrate - see CONFIG_BAUDRATE
4595 bootdelay - see CONFIG_BOOTDELAY
4597 bootcmd - see CONFIG_BOOTCOMMAND
4599 bootargs - Boot arguments when booting an RTOS image
4601 bootfile - Name of the image to load with TFTP
4603 bootm_low - Memory range available for image processing in the bootm
4604 command can be restricted. This variable is given as
4605 a hexadecimal number and defines lowest address allowed
4606 for use by the bootm command. See also "bootm_size"
4607 environment variable. Address defined by "bootm_low" is
4608 also the base of the initial memory mapping for the Linux
4609 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4612 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4613 This variable is given as a hexadecimal number and it
4614 defines the size of the memory region starting at base
4615 address bootm_low that is accessible by the Linux kernel
4616 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4617 as the default value if it is defined, and bootm_size is
4620 bootm_size - Memory range available for image processing in the bootm
4621 command can be restricted. This variable is given as
4622 a hexadecimal number and defines the size of the region
4623 allowed for use by the bootm command. See also "bootm_low"
4624 environment variable.
4626 updatefile - Location of the software update file on a TFTP server, used
4627 by the automatic software update feature. Please refer to
4628 documentation in doc/README.update for more details.
4630 autoload - if set to "no" (any string beginning with 'n'),
4631 "bootp" will just load perform a lookup of the
4632 configuration from the BOOTP server, but not try to
4633 load any image using TFTP
4635 autostart - if set to "yes", an image loaded using the "bootp",
4636 "rarpboot", "tftpboot" or "diskboot" commands will
4637 be automatically started (by internally calling
4640 If set to "no", a standalone image passed to the
4641 "bootm" command will be copied to the load address
4642 (and eventually uncompressed), but NOT be started.
4643 This can be used to load and uncompress arbitrary
4646 fdt_high - if set this restricts the maximum address that the
4647 flattened device tree will be copied into upon boot.
4648 For example, if you have a system with 1 GB memory
4649 at physical address 0x10000000, while Linux kernel
4650 only recognizes the first 704 MB as low memory, you
4651 may need to set fdt_high as 0x3C000000 to have the
4652 device tree blob be copied to the maximum address
4653 of the 704 MB low memory, so that Linux kernel can
4654 access it during the boot procedure.
4656 If this is set to the special value 0xFFFFFFFF then
4657 the fdt will not be copied at all on boot. For this
4658 to work it must reside in writable memory, have
4659 sufficient padding on the end of it for u-boot to
4660 add the information it needs into it, and the memory
4661 must be accessible by the kernel.
4663 fdtcontroladdr- if set this is the address of the control flattened
4664 device tree used by U-Boot when CONFIG_OF_CONTROL is
4667 i2cfast - (PPC405GP|PPC405EP only)
4668 if set to 'y' configures Linux I2C driver for fast
4669 mode (400kHZ). This environment variable is used in
4670 initialization code. So, for changes to be effective
4671 it must be saved and board must be reset.
4673 initrd_high - restrict positioning of initrd images:
4674 If this variable is not set, initrd images will be
4675 copied to the highest possible address in RAM; this
4676 is usually what you want since it allows for
4677 maximum initrd size. If for some reason you want to
4678 make sure that the initrd image is loaded below the
4679 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4680 variable to a value of "no" or "off" or "0".
4681 Alternatively, you can set it to a maximum upper
4682 address to use (U-Boot will still check that it
4683 does not overwrite the U-Boot stack and data).
4685 For instance, when you have a system with 16 MB
4686 RAM, and want to reserve 4 MB from use by Linux,
4687 you can do this by adding "mem=12M" to the value of
4688 the "bootargs" variable. However, now you must make
4689 sure that the initrd image is placed in the first
4690 12 MB as well - this can be done with
4692 setenv initrd_high 00c00000
4694 If you set initrd_high to 0xFFFFFFFF, this is an
4695 indication to U-Boot that all addresses are legal
4696 for the Linux kernel, including addresses in flash
4697 memory. In this case U-Boot will NOT COPY the
4698 ramdisk at all. This may be useful to reduce the
4699 boot time on your system, but requires that this
4700 feature is supported by your Linux kernel.
4702 ipaddr - IP address; needed for tftpboot command
4704 loadaddr - Default load address for commands like "bootp",
4705 "rarpboot", "tftpboot", "loadb" or "diskboot"
4707 loads_echo - see CONFIG_LOADS_ECHO
4709 serverip - TFTP server IP address; needed for tftpboot command
4711 bootretry - see CONFIG_BOOT_RETRY_TIME
4713 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4715 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4717 ethprime - controls which interface is used first.
4719 ethact - controls which interface is currently active.
4720 For example you can do the following
4722 => setenv ethact FEC
4723 => ping 192.168.0.1 # traffic sent on FEC
4724 => setenv ethact SCC
4725 => ping 10.0.0.1 # traffic sent on SCC
4727 ethrotate - When set to "no" U-Boot does not go through all
4728 available network interfaces.
4729 It just stays at the currently selected interface.
4731 netretry - When set to "no" each network operation will
4732 either succeed or fail without retrying.
4733 When set to "once" the network operation will
4734 fail when all the available network interfaces
4735 are tried once without success.
4736 Useful on scripts which control the retry operation
4739 npe_ucode - set load address for the NPE microcode
4741 silent_linux - If set then linux will be told to boot silently, by
4742 changing the console to be empty. If "yes" it will be
4743 made silent. If "no" it will not be made silent. If
4744 unset, then it will be made silent if the U-Boot console
4747 tftpsrcport - If this is set, the value is used for TFTP's
4750 tftpdstport - If this is set, the value is used for TFTP's UDP
4751 destination port instead of the Well Know Port 69.
4753 tftpblocksize - Block size to use for TFTP transfers; if not set,
4754 we use the TFTP server's default block size
4756 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4757 seconds, minimum value is 1000 = 1 second). Defines
4758 when a packet is considered to be lost so it has to
4759 be retransmitted. The default is 5000 = 5 seconds.
4760 Lowering this value may make downloads succeed
4761 faster in networks with high packet loss rates or
4762 with unreliable TFTP servers.
4764 vlan - When set to a value < 4095 the traffic over
4765 Ethernet is encapsulated/received over 802.1q
4768 The following image location variables contain the location of images
4769 used in booting. The "Image" column gives the role of the image and is
4770 not an environment variable name. The other columns are environment
4771 variable names. "File Name" gives the name of the file on a TFTP
4772 server, "RAM Address" gives the location in RAM the image will be
4773 loaded to, and "Flash Location" gives the image's address in NOR
4774 flash or offset in NAND flash.
4776 *Note* - these variables don't have to be defined for all boards, some
4777 boards currenlty use other variables for these purposes, and some
4778 boards use these variables for other purposes.
4780 Image File Name RAM Address Flash Location
4781 ----- --------- ----------- --------------
4782 u-boot u-boot u-boot_addr_r u-boot_addr
4783 Linux kernel bootfile kernel_addr_r kernel_addr
4784 device tree blob fdtfile fdt_addr_r fdt_addr
4785 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4787 The following environment variables may be used and automatically
4788 updated by the network boot commands ("bootp" and "rarpboot"),
4789 depending the information provided by your boot server:
4791 bootfile - see above
4792 dnsip - IP address of your Domain Name Server
4793 dnsip2 - IP address of your secondary Domain Name Server
4794 gatewayip - IP address of the Gateway (Router) to use
4795 hostname - Target hostname
4797 netmask - Subnet Mask
4798 rootpath - Pathname of the root filesystem on the NFS server
4799 serverip - see above
4802 There are two special Environment Variables:
4804 serial# - contains hardware identification information such
4805 as type string and/or serial number
4806 ethaddr - Ethernet address
4808 These variables can be set only once (usually during manufacturing of
4809 the board). U-Boot refuses to delete or overwrite these variables
4810 once they have been set once.
4813 Further special Environment Variables:
4815 ver - Contains the U-Boot version string as printed
4816 with the "version" command. This variable is
4817 readonly (see CONFIG_VERSION_VARIABLE).
4820 Please note that changes to some configuration parameters may take
4821 only effect after the next boot (yes, that's just like Windoze :-).
4824 Callback functions for environment variables:
4825 ---------------------------------------------
4827 For some environment variables, the behavior of u-boot needs to change
4828 when their values are changed. This functionailty allows functions to
4829 be associated with arbitrary variables. On creation, overwrite, or
4830 deletion, the callback will provide the opportunity for some side
4831 effect to happen or for the change to be rejected.
4833 The callbacks are named and associated with a function using the
4834 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4836 These callbacks are associated with variables in one of two ways. The
4837 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4838 in the board configuration to a string that defines a list of
4839 associations. The list must be in the following format:
4841 entry = variable_name[:callback_name]
4844 If the callback name is not specified, then the callback is deleted.
4845 Spaces are also allowed anywhere in the list.
4847 Callbacks can also be associated by defining the ".callbacks" variable
4848 with the same list format above. Any association in ".callbacks" will
4849 override any association in the static list. You can define
4850 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4851 ".callbacks" envirnoment variable in the default or embedded environment.
4854 Command Line Parsing:
4855 =====================
4857 There are two different command line parsers available with U-Boot:
4858 the old "simple" one, and the much more powerful "hush" shell:
4860 Old, simple command line parser:
4861 --------------------------------
4863 - supports environment variables (through setenv / saveenv commands)
4864 - several commands on one line, separated by ';'
4865 - variable substitution using "... ${name} ..." syntax
4866 - special characters ('$', ';') can be escaped by prefixing with '\',
4868 setenv bootcmd bootm \${address}
4869 - You can also escape text by enclosing in single apostrophes, for example:
4870 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4875 - similar to Bourne shell, with control structures like
4876 if...then...else...fi, for...do...done; while...do...done,
4877 until...do...done, ...
4878 - supports environment ("global") variables (through setenv / saveenv
4879 commands) and local shell variables (through standard shell syntax
4880 "name=value"); only environment variables can be used with "run"
4886 (1) If a command line (or an environment variable executed by a "run"
4887 command) contains several commands separated by semicolon, and
4888 one of these commands fails, then the remaining commands will be
4891 (2) If you execute several variables with one call to run (i. e.
4892 calling run with a list of variables as arguments), any failing
4893 command will cause "run" to terminate, i. e. the remaining
4894 variables are not executed.
4896 Note for Redundant Ethernet Interfaces:
4897 =======================================
4899 Some boards come with redundant Ethernet interfaces; U-Boot supports
4900 such configurations and is capable of automatic selection of a
4901 "working" interface when needed. MAC assignment works as follows:
4903 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4904 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4905 "eth1addr" (=>eth1), "eth2addr", ...
4907 If the network interface stores some valid MAC address (for instance
4908 in SROM), this is used as default address if there is NO correspon-
4909 ding setting in the environment; if the corresponding environment
4910 variable is set, this overrides the settings in the card; that means:
4912 o If the SROM has a valid MAC address, and there is no address in the
4913 environment, the SROM's address is used.
4915 o If there is no valid address in the SROM, and a definition in the
4916 environment exists, then the value from the environment variable is
4919 o If both the SROM and the environment contain a MAC address, and
4920 both addresses are the same, this MAC address is used.
4922 o If both the SROM and the environment contain a MAC address, and the
4923 addresses differ, the value from the environment is used and a
4926 o If neither SROM nor the environment contain a MAC address, an error
4929 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4930 will be programmed into hardware as part of the initialization process. This
4931 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4932 The naming convention is as follows:
4933 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4938 U-Boot is capable of booting (and performing other auxiliary operations on)
4939 images in two formats:
4941 New uImage format (FIT)
4942 -----------------------
4944 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4945 to Flattened Device Tree). It allows the use of images with multiple
4946 components (several kernels, ramdisks, etc.), with contents protected by
4947 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4953 Old image format is based on binary files which can be basically anything,
4954 preceded by a special header; see the definitions in include/image.h for
4955 details; basically, the header defines the following image properties:
4957 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4958 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4959 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4960 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4962 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4963 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4964 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4965 * Compression Type (uncompressed, gzip, bzip2)
4971 The header is marked by a special Magic Number, and both the header
4972 and the data portions of the image are secured against corruption by
4979 Although U-Boot should support any OS or standalone application
4980 easily, the main focus has always been on Linux during the design of
4983 U-Boot includes many features that so far have been part of some
4984 special "boot loader" code within the Linux kernel. Also, any
4985 "initrd" images to be used are no longer part of one big Linux image;
4986 instead, kernel and "initrd" are separate images. This implementation
4987 serves several purposes:
4989 - the same features can be used for other OS or standalone
4990 applications (for instance: using compressed images to reduce the
4991 Flash memory footprint)
4993 - it becomes much easier to port new Linux kernel versions because
4994 lots of low-level, hardware dependent stuff are done by U-Boot
4996 - the same Linux kernel image can now be used with different "initrd"
4997 images; of course this also means that different kernel images can
4998 be run with the same "initrd". This makes testing easier (you don't
4999 have to build a new "zImage.initrd" Linux image when you just
5000 change a file in your "initrd"). Also, a field-upgrade of the
5001 software is easier now.
5007 Porting Linux to U-Boot based systems:
5008 ---------------------------------------
5010 U-Boot cannot save you from doing all the necessary modifications to
5011 configure the Linux device drivers for use with your target hardware
5012 (no, we don't intend to provide a full virtual machine interface to
5015 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5017 Just make sure your machine specific header file (for instance
5018 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5019 Information structure as we define in include/asm-<arch>/u-boot.h,
5020 and make sure that your definition of IMAP_ADDR uses the same value
5021 as your U-Boot configuration in CONFIG_SYS_IMMR.
5024 Configuring the Linux kernel:
5025 -----------------------------
5027 No specific requirements for U-Boot. Make sure you have some root
5028 device (initial ramdisk, NFS) for your target system.
5031 Building a Linux Image:
5032 -----------------------
5034 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5035 not used. If you use recent kernel source, a new build target
5036 "uImage" will exist which automatically builds an image usable by
5037 U-Boot. Most older kernels also have support for a "pImage" target,
5038 which was introduced for our predecessor project PPCBoot and uses a
5039 100% compatible format.
5048 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5049 encapsulate a compressed Linux kernel image with header information,
5050 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5052 * build a standard "vmlinux" kernel image (in ELF binary format):
5054 * convert the kernel into a raw binary image:
5056 ${CROSS_COMPILE}-objcopy -O binary \
5057 -R .note -R .comment \
5058 -S vmlinux linux.bin
5060 * compress the binary image:
5064 * package compressed binary image for U-Boot:
5066 mkimage -A ppc -O linux -T kernel -C gzip \
5067 -a 0 -e 0 -n "Linux Kernel Image" \
5068 -d linux.bin.gz uImage
5071 The "mkimage" tool can also be used to create ramdisk images for use
5072 with U-Boot, either separated from the Linux kernel image, or
5073 combined into one file. "mkimage" encapsulates the images with a 64
5074 byte header containing information about target architecture,
5075 operating system, image type, compression method, entry points, time
5076 stamp, CRC32 checksums, etc.
5078 "mkimage" can be called in two ways: to verify existing images and
5079 print the header information, or to build new images.
5081 In the first form (with "-l" option) mkimage lists the information
5082 contained in the header of an existing U-Boot image; this includes
5083 checksum verification:
5085 tools/mkimage -l image
5086 -l ==> list image header information
5088 The second form (with "-d" option) is used to build a U-Boot image
5089 from a "data file" which is used as image payload:
5091 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5092 -n name -d data_file image
5093 -A ==> set architecture to 'arch'
5094 -O ==> set operating system to 'os'
5095 -T ==> set image type to 'type'
5096 -C ==> set compression type 'comp'
5097 -a ==> set load address to 'addr' (hex)
5098 -e ==> set entry point to 'ep' (hex)
5099 -n ==> set image name to 'name'
5100 -d ==> use image data from 'datafile'
5102 Right now, all Linux kernels for PowerPC systems use the same load
5103 address (0x00000000), but the entry point address depends on the
5106 - 2.2.x kernels have the entry point at 0x0000000C,
5107 - 2.3.x and later kernels have the entry point at 0x00000000.
5109 So a typical call to build a U-Boot image would read:
5111 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5112 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5113 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5114 > examples/uImage.TQM850L
5115 Image Name: 2.4.4 kernel for TQM850L
5116 Created: Wed Jul 19 02:34:59 2000
5117 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5118 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5119 Load Address: 0x00000000
5120 Entry Point: 0x00000000
5122 To verify the contents of the image (or check for corruption):
5124 -> tools/mkimage -l examples/uImage.TQM850L
5125 Image Name: 2.4.4 kernel for TQM850L
5126 Created: Wed Jul 19 02:34:59 2000
5127 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5128 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5129 Load Address: 0x00000000
5130 Entry Point: 0x00000000
5132 NOTE: for embedded systems where boot time is critical you can trade
5133 speed for memory and install an UNCOMPRESSED image instead: this
5134 needs more space in Flash, but boots much faster since it does not
5135 need to be uncompressed:
5137 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5138 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5139 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5140 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5141 > examples/uImage.TQM850L-uncompressed
5142 Image Name: 2.4.4 kernel for TQM850L
5143 Created: Wed Jul 19 02:34:59 2000
5144 Image Type: PowerPC Linux Kernel Image (uncompressed)
5145 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5146 Load Address: 0x00000000
5147 Entry Point: 0x00000000
5150 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5151 when your kernel is intended to use an initial ramdisk:
5153 -> tools/mkimage -n 'Simple Ramdisk Image' \
5154 > -A ppc -O linux -T ramdisk -C gzip \
5155 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5156 Image Name: Simple Ramdisk Image
5157 Created: Wed Jan 12 14:01:50 2000
5158 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5159 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5160 Load Address: 0x00000000
5161 Entry Point: 0x00000000
5164 Installing a Linux Image:
5165 -------------------------
5167 To downloading a U-Boot image over the serial (console) interface,
5168 you must convert the image to S-Record format:
5170 objcopy -I binary -O srec examples/image examples/image.srec
5172 The 'objcopy' does not understand the information in the U-Boot
5173 image header, so the resulting S-Record file will be relative to
5174 address 0x00000000. To load it to a given address, you need to
5175 specify the target address as 'offset' parameter with the 'loads'
5178 Example: install the image to address 0x40100000 (which on the
5179 TQM8xxL is in the first Flash bank):
5181 => erase 40100000 401FFFFF
5187 ## Ready for S-Record download ...
5188 ~>examples/image.srec
5189 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5191 15989 15990 15991 15992
5192 [file transfer complete]
5194 ## Start Addr = 0x00000000
5197 You can check the success of the download using the 'iminfo' command;
5198 this includes a checksum verification so you can be sure no data
5199 corruption happened:
5203 ## Checking Image at 40100000 ...
5204 Image Name: 2.2.13 for initrd on TQM850L
5205 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5206 Data Size: 335725 Bytes = 327 kB = 0 MB
5207 Load Address: 00000000
5208 Entry Point: 0000000c
5209 Verifying Checksum ... OK
5215 The "bootm" command is used to boot an application that is stored in
5216 memory (RAM or Flash). In case of a Linux kernel image, the contents
5217 of the "bootargs" environment variable is passed to the kernel as
5218 parameters. You can check and modify this variable using the
5219 "printenv" and "setenv" commands:
5222 => printenv bootargs
5223 bootargs=root=/dev/ram
5225 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5227 => printenv bootargs
5228 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5231 ## Booting Linux kernel at 40020000 ...
5232 Image Name: 2.2.13 for NFS on TQM850L
5233 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5234 Data Size: 381681 Bytes = 372 kB = 0 MB
5235 Load Address: 00000000
5236 Entry Point: 0000000c
5237 Verifying Checksum ... OK
5238 Uncompressing Kernel Image ... OK
5239 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
5240 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5241 time_init: decrementer frequency = 187500000/60
5242 Calibrating delay loop... 49.77 BogoMIPS
5243 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5246 If you want to boot a Linux kernel with initial RAM disk, you pass
5247 the memory addresses of both the kernel and the initrd image (PPBCOOT
5248 format!) to the "bootm" command:
5250 => imi 40100000 40200000
5252 ## Checking Image at 40100000 ...
5253 Image Name: 2.2.13 for initrd on TQM850L
5254 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5255 Data Size: 335725 Bytes = 327 kB = 0 MB
5256 Load Address: 00000000
5257 Entry Point: 0000000c
5258 Verifying Checksum ... OK
5260 ## Checking Image at 40200000 ...
5261 Image Name: Simple Ramdisk Image
5262 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5263 Data Size: 566530 Bytes = 553 kB = 0 MB
5264 Load Address: 00000000
5265 Entry Point: 00000000
5266 Verifying Checksum ... OK
5268 => bootm 40100000 40200000
5269 ## Booting Linux kernel at 40100000 ...
5270 Image Name: 2.2.13 for initrd on TQM850L
5271 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5272 Data Size: 335725 Bytes = 327 kB = 0 MB
5273 Load Address: 00000000
5274 Entry Point: 0000000c
5275 Verifying Checksum ... OK
5276 Uncompressing Kernel Image ... OK
5277 ## Loading RAMDisk Image at 40200000 ...
5278 Image Name: Simple Ramdisk Image
5279 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5280 Data Size: 566530 Bytes = 553 kB = 0 MB
5281 Load Address: 00000000
5282 Entry Point: 00000000
5283 Verifying Checksum ... OK
5284 Loading Ramdisk ... OK
5285 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
5286 Boot arguments: root=/dev/ram
5287 time_init: decrementer frequency = 187500000/60
5288 Calibrating delay loop... 49.77 BogoMIPS
5290 RAMDISK: Compressed image found at block 0
5291 VFS: Mounted root (ext2 filesystem).
5295 Boot Linux and pass a flat device tree:
5298 First, U-Boot must be compiled with the appropriate defines. See the section
5299 titled "Linux Kernel Interface" above for a more in depth explanation. The
5300 following is an example of how to start a kernel and pass an updated
5306 oft=oftrees/mpc8540ads.dtb
5307 => tftp $oftaddr $oft
5308 Speed: 1000, full duplex
5310 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5311 Filename 'oftrees/mpc8540ads.dtb'.
5312 Load address: 0x300000
5315 Bytes transferred = 4106 (100a hex)
5316 => tftp $loadaddr $bootfile
5317 Speed: 1000, full duplex
5319 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5321 Load address: 0x200000
5322 Loading:############
5324 Bytes transferred = 1029407 (fb51f hex)
5329 => bootm $loadaddr - $oftaddr
5330 ## Booting image at 00200000 ...
5331 Image Name: Linux-2.6.17-dirty
5332 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5333 Data Size: 1029343 Bytes = 1005.2 kB
5334 Load Address: 00000000
5335 Entry Point: 00000000
5336 Verifying Checksum ... OK
5337 Uncompressing Kernel Image ... OK
5338 Booting using flat device tree at 0x300000
5339 Using MPC85xx ADS machine description
5340 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5344 More About U-Boot Image Types:
5345 ------------------------------
5347 U-Boot supports the following image types:
5349 "Standalone Programs" are directly runnable in the environment
5350 provided by U-Boot; it is expected that (if they behave
5351 well) you can continue to work in U-Boot after return from
5352 the Standalone Program.
5353 "OS Kernel Images" are usually images of some Embedded OS which
5354 will take over control completely. Usually these programs
5355 will install their own set of exception handlers, device
5356 drivers, set up the MMU, etc. - this means, that you cannot
5357 expect to re-enter U-Boot except by resetting the CPU.
5358 "RAMDisk Images" are more or less just data blocks, and their
5359 parameters (address, size) are passed to an OS kernel that is
5361 "Multi-File Images" contain several images, typically an OS
5362 (Linux) kernel image and one or more data images like
5363 RAMDisks. This construct is useful for instance when you want
5364 to boot over the network using BOOTP etc., where the boot
5365 server provides just a single image file, but you want to get
5366 for instance an OS kernel and a RAMDisk image.
5368 "Multi-File Images" start with a list of image sizes, each
5369 image size (in bytes) specified by an "uint32_t" in network
5370 byte order. This list is terminated by an "(uint32_t)0".
5371 Immediately after the terminating 0 follow the images, one by
5372 one, all aligned on "uint32_t" boundaries (size rounded up to
5373 a multiple of 4 bytes).
5375 "Firmware Images" are binary images containing firmware (like
5376 U-Boot or FPGA images) which usually will be programmed to
5379 "Script files" are command sequences that will be executed by
5380 U-Boot's command interpreter; this feature is especially
5381 useful when you configure U-Boot to use a real shell (hush)
5382 as command interpreter.
5384 Booting the Linux zImage:
5385 -------------------------
5387 On some platforms, it's possible to boot Linux zImage. This is done
5388 using the "bootz" command. The syntax of "bootz" command is the same
5389 as the syntax of "bootm" command.
5391 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5392 kernel with raw initrd images. The syntax is slightly different, the
5393 address of the initrd must be augmented by it's size, in the following
5394 format: "<initrd addres>:<initrd size>".
5400 One of the features of U-Boot is that you can dynamically load and
5401 run "standalone" applications, which can use some resources of
5402 U-Boot like console I/O functions or interrupt services.
5404 Two simple examples are included with the sources:
5409 'examples/hello_world.c' contains a small "Hello World" Demo
5410 application; it is automatically compiled when you build U-Boot.
5411 It's configured to run at address 0x00040004, so you can play with it
5415 ## Ready for S-Record download ...
5416 ~>examples/hello_world.srec
5417 1 2 3 4 5 6 7 8 9 10 11 ...
5418 [file transfer complete]
5420 ## Start Addr = 0x00040004
5422 => go 40004 Hello World! This is a test.
5423 ## Starting application at 0x00040004 ...
5434 Hit any key to exit ...
5436 ## Application terminated, rc = 0x0
5438 Another example, which demonstrates how to register a CPM interrupt
5439 handler with the U-Boot code, can be found in 'examples/timer.c'.
5440 Here, a CPM timer is set up to generate an interrupt every second.
5441 The interrupt service routine is trivial, just printing a '.'
5442 character, but this is just a demo program. The application can be
5443 controlled by the following keys:
5445 ? - print current values og the CPM Timer registers
5446 b - enable interrupts and start timer
5447 e - stop timer and disable interrupts
5448 q - quit application
5451 ## Ready for S-Record download ...
5452 ~>examples/timer.srec
5453 1 2 3 4 5 6 7 8 9 10 11 ...
5454 [file transfer complete]
5456 ## Start Addr = 0x00040004
5459 ## Starting application at 0x00040004 ...
5462 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5465 [q, b, e, ?] Set interval 1000000 us
5468 [q, b, e, ?] ........
5469 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5472 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5475 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5478 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5480 [q, b, e, ?] ...Stopping timer
5482 [q, b, e, ?] ## Application terminated, rc = 0x0
5488 Over time, many people have reported problems when trying to use the
5489 "minicom" terminal emulation program for serial download. I (wd)
5490 consider minicom to be broken, and recommend not to use it. Under
5491 Unix, I recommend to use C-Kermit for general purpose use (and
5492 especially for kermit binary protocol download ("loadb" command), and
5493 use "cu" for S-Record download ("loads" command). See
5494 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5495 for help with kermit.
5498 Nevertheless, if you absolutely want to use it try adding this
5499 configuration to your "File transfer protocols" section:
5501 Name Program Name U/D FullScr IO-Red. Multi
5502 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5503 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5509 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5510 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5512 Building requires a cross environment; it is known to work on
5513 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5514 need gmake since the Makefiles are not compatible with BSD make).
5515 Note that the cross-powerpc package does not install include files;
5516 attempting to build U-Boot will fail because <machine/ansi.h> is
5517 missing. This file has to be installed and patched manually:
5519 # cd /usr/pkg/cross/powerpc-netbsd/include
5521 # ln -s powerpc machine
5522 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5523 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5525 Native builds *don't* work due to incompatibilities between native
5526 and U-Boot include files.
5528 Booting assumes that (the first part of) the image booted is a
5529 stage-2 loader which in turn loads and then invokes the kernel
5530 proper. Loader sources will eventually appear in the NetBSD source
5531 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5532 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5535 Implementation Internals:
5536 =========================
5538 The following is not intended to be a complete description of every
5539 implementation detail. However, it should help to understand the
5540 inner workings of U-Boot and make it easier to port it to custom
5544 Initial Stack, Global Data:
5545 ---------------------------
5547 The implementation of U-Boot is complicated by the fact that U-Boot
5548 starts running out of ROM (flash memory), usually without access to
5549 system RAM (because the memory controller is not initialized yet).
5550 This means that we don't have writable Data or BSS segments, and BSS
5551 is not initialized as zero. To be able to get a C environment working
5552 at all, we have to allocate at least a minimal stack. Implementation
5553 options for this are defined and restricted by the CPU used: Some CPU
5554 models provide on-chip memory (like the IMMR area on MPC8xx and
5555 MPC826x processors), on others (parts of) the data cache can be
5556 locked as (mis-) used as memory, etc.
5558 Chris Hallinan posted a good summary of these issues to the
5559 U-Boot mailing list:
5561 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5562 From: "Chris Hallinan" <clh@net1plus.com>
5563 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5566 Correct me if I'm wrong, folks, but the way I understand it
5567 is this: Using DCACHE as initial RAM for Stack, etc, does not
5568 require any physical RAM backing up the cache. The cleverness
5569 is that the cache is being used as a temporary supply of
5570 necessary storage before the SDRAM controller is setup. It's
5571 beyond the scope of this list to explain the details, but you
5572 can see how this works by studying the cache architecture and
5573 operation in the architecture and processor-specific manuals.
5575 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5576 is another option for the system designer to use as an
5577 initial stack/RAM area prior to SDRAM being available. Either
5578 option should work for you. Using CS 4 should be fine if your
5579 board designers haven't used it for something that would
5580 cause you grief during the initial boot! It is frequently not
5583 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5584 with your processor/board/system design. The default value
5585 you will find in any recent u-boot distribution in
5586 walnut.h should work for you. I'd set it to a value larger
5587 than your SDRAM module. If you have a 64MB SDRAM module, set
5588 it above 400_0000. Just make sure your board has no resources
5589 that are supposed to respond to that address! That code in
5590 start.S has been around a while and should work as is when
5591 you get the config right.
5596 It is essential to remember this, since it has some impact on the C
5597 code for the initialization procedures:
5599 * Initialized global data (data segment) is read-only. Do not attempt
5602 * Do not use any uninitialized global data (or implicitely initialized
5603 as zero data - BSS segment) at all - this is undefined, initiali-
5604 zation is performed later (when relocating to RAM).
5606 * Stack space is very limited. Avoid big data buffers or things like
5609 Having only the stack as writable memory limits means we cannot use
5610 normal global data to share information beween the code. But it
5611 turned out that the implementation of U-Boot can be greatly
5612 simplified by making a global data structure (gd_t) available to all
5613 functions. We could pass a pointer to this data as argument to _all_
5614 functions, but this would bloat the code. Instead we use a feature of
5615 the GCC compiler (Global Register Variables) to share the data: we
5616 place a pointer (gd) to the global data into a register which we
5617 reserve for this purpose.
5619 When choosing a register for such a purpose we are restricted by the
5620 relevant (E)ABI specifications for the current architecture, and by
5621 GCC's implementation.
5623 For PowerPC, the following registers have specific use:
5625 R2: reserved for system use
5626 R3-R4: parameter passing and return values
5627 R5-R10: parameter passing
5628 R13: small data area pointer
5632 (U-Boot also uses R12 as internal GOT pointer. r12
5633 is a volatile register so r12 needs to be reset when
5634 going back and forth between asm and C)
5636 ==> U-Boot will use R2 to hold a pointer to the global data
5638 Note: on PPC, we could use a static initializer (since the
5639 address of the global data structure is known at compile time),
5640 but it turned out that reserving a register results in somewhat
5641 smaller code - although the code savings are not that big (on
5642 average for all boards 752 bytes for the whole U-Boot image,
5643 624 text + 127 data).
5645 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5646 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5648 ==> U-Boot will use P3 to hold a pointer to the global data
5650 On ARM, the following registers are used:
5652 R0: function argument word/integer result
5653 R1-R3: function argument word
5654 R9: platform specific
5655 R10: stack limit (used only if stack checking is enabled)
5656 R11: argument (frame) pointer
5657 R12: temporary workspace
5660 R15: program counter
5662 ==> U-Boot will use R9 to hold a pointer to the global data
5664 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5666 On Nios II, the ABI is documented here:
5667 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5669 ==> U-Boot will use gp to hold a pointer to the global data
5671 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5672 to access small data sections, so gp is free.
5674 On NDS32, the following registers are used:
5676 R0-R1: argument/return
5678 R15: temporary register for assembler
5679 R16: trampoline register
5680 R28: frame pointer (FP)
5681 R29: global pointer (GP)
5682 R30: link register (LP)
5683 R31: stack pointer (SP)
5684 PC: program counter (PC)
5686 ==> U-Boot will use R10 to hold a pointer to the global data
5688 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5689 or current versions of GCC may "optimize" the code too much.
5694 U-Boot runs in system state and uses physical addresses, i.e. the
5695 MMU is not used either for address mapping nor for memory protection.
5697 The available memory is mapped to fixed addresses using the memory
5698 controller. In this process, a contiguous block is formed for each
5699 memory type (Flash, SDRAM, SRAM), even when it consists of several
5700 physical memory banks.
5702 U-Boot is installed in the first 128 kB of the first Flash bank (on
5703 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5704 booting and sizing and initializing DRAM, the code relocates itself
5705 to the upper end of DRAM. Immediately below the U-Boot code some
5706 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5707 configuration setting]. Below that, a structure with global Board
5708 Info data is placed, followed by the stack (growing downward).
5710 Additionally, some exception handler code is copied to the low 8 kB
5711 of DRAM (0x00000000 ... 0x00001FFF).
5713 So a typical memory configuration with 16 MB of DRAM could look like
5716 0x0000 0000 Exception Vector code
5719 0x0000 2000 Free for Application Use
5725 0x00FB FF20 Monitor Stack (Growing downward)
5726 0x00FB FFAC Board Info Data and permanent copy of global data
5727 0x00FC 0000 Malloc Arena
5730 0x00FE 0000 RAM Copy of Monitor Code
5731 ... eventually: LCD or video framebuffer
5732 ... eventually: pRAM (Protected RAM - unchanged by reset)
5733 0x00FF FFFF [End of RAM]
5736 System Initialization:
5737 ----------------------
5739 In the reset configuration, U-Boot starts at the reset entry point
5740 (on most PowerPC systems at address 0x00000100). Because of the reset
5741 configuration for CS0# this is a mirror of the onboard Flash memory.
5742 To be able to re-map memory U-Boot then jumps to its link address.
5743 To be able to implement the initialization code in C, a (small!)
5744 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5745 which provide such a feature like MPC8xx or MPC8260), or in a locked
5746 part of the data cache. After that, U-Boot initializes the CPU core,
5747 the caches and the SIU.
5749 Next, all (potentially) available memory banks are mapped using a
5750 preliminary mapping. For example, we put them on 512 MB boundaries
5751 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5752 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5753 programmed for SDRAM access. Using the temporary configuration, a
5754 simple memory test is run that determines the size of the SDRAM
5757 When there is more than one SDRAM bank, and the banks are of
5758 different size, the largest is mapped first. For equal size, the first
5759 bank (CS2#) is mapped first. The first mapping is always for address
5760 0x00000000, with any additional banks following immediately to create
5761 contiguous memory starting from 0.
5763 Then, the monitor installs itself at the upper end of the SDRAM area
5764 and allocates memory for use by malloc() and for the global Board
5765 Info data; also, the exception vector code is copied to the low RAM
5766 pages, and the final stack is set up.
5768 Only after this relocation will you have a "normal" C environment;
5769 until that you are restricted in several ways, mostly because you are
5770 running from ROM, and because the code will have to be relocated to a
5774 U-Boot Porting Guide:
5775 ----------------------
5777 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5781 int main(int argc, char *argv[])
5783 sighandler_t no_more_time;
5785 signal(SIGALRM, no_more_time);
5786 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5788 if (available_money > available_manpower) {
5789 Pay consultant to port U-Boot;
5793 Download latest U-Boot source;
5795 Subscribe to u-boot mailing list;
5798 email("Hi, I am new to U-Boot, how do I get started?");
5801 Read the README file in the top level directory;
5802 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5803 Read applicable doc/*.README;
5804 Read the source, Luke;
5805 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5808 if (available_money > toLocalCurrency ($2500))
5811 Add a lot of aggravation and time;
5813 if (a similar board exists) { /* hopefully... */
5814 cp -a board/<similar> board/<myboard>
5815 cp include/configs/<similar>.h include/configs/<myboard>.h
5817 Create your own board support subdirectory;
5818 Create your own board include/configs/<myboard>.h file;
5820 Edit new board/<myboard> files
5821 Edit new include/configs/<myboard>.h
5826 Add / modify source code;
5830 email("Hi, I am having problems...");
5832 Send patch file to the U-Boot email list;
5833 if (reasonable critiques)
5834 Incorporate improvements from email list code review;
5836 Defend code as written;
5842 void no_more_time (int sig)
5851 All contributions to U-Boot should conform to the Linux kernel
5852 coding style; see the file "Documentation/CodingStyle" and the script
5853 "scripts/Lindent" in your Linux kernel source directory.
5855 Source files originating from a different project (for example the
5856 MTD subsystem) are generally exempt from these guidelines and are not
5857 reformated to ease subsequent migration to newer versions of those
5860 Please note that U-Boot is implemented in C (and to some small parts in
5861 Assembler); no C++ is used, so please do not use C++ style comments (//)
5864 Please also stick to the following formatting rules:
5865 - remove any trailing white space
5866 - use TAB characters for indentation and vertical alignment, not spaces
5867 - make sure NOT to use DOS '\r\n' line feeds
5868 - do not add more than 2 consecutive empty lines to source files
5869 - do not add trailing empty lines to source files
5871 Submissions which do not conform to the standards may be returned
5872 with a request to reformat the changes.
5878 Since the number of patches for U-Boot is growing, we need to
5879 establish some rules. Submissions which do not conform to these rules
5880 may be rejected, even when they contain important and valuable stuff.
5882 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5884 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5885 see http://lists.denx.de/mailman/listinfo/u-boot
5887 When you send a patch, please include the following information with
5890 * For bug fixes: a description of the bug and how your patch fixes
5891 this bug. Please try to include a way of demonstrating that the
5892 patch actually fixes something.
5894 * For new features: a description of the feature and your
5897 * A CHANGELOG entry as plaintext (separate from the patch)
5899 * For major contributions, your entry to the CREDITS file
5901 * When you add support for a new board, don't forget to add a
5902 maintainer e-mail address to the boards.cfg file, too.
5904 * If your patch adds new configuration options, don't forget to
5905 document these in the README file.
5907 * The patch itself. If you are using git (which is *strongly*
5908 recommended) you can easily generate the patch using the
5909 "git format-patch". If you then use "git send-email" to send it to
5910 the U-Boot mailing list, you will avoid most of the common problems
5911 with some other mail clients.
5913 If you cannot use git, use "diff -purN OLD NEW". If your version of
5914 diff does not support these options, then get the latest version of
5917 The current directory when running this command shall be the parent
5918 directory of the U-Boot source tree (i. e. please make sure that
5919 your patch includes sufficient directory information for the
5922 We prefer patches as plain text. MIME attachments are discouraged,
5923 and compressed attachments must not be used.
5925 * If one logical set of modifications affects or creates several
5926 files, all these changes shall be submitted in a SINGLE patch file.
5928 * Changesets that contain different, unrelated modifications shall be
5929 submitted as SEPARATE patches, one patch per changeset.
5934 * Before sending the patch, run the MAKEALL script on your patched
5935 source tree and make sure that no errors or warnings are reported
5936 for any of the boards.
5938 * Keep your modifications to the necessary minimum: A patch
5939 containing several unrelated changes or arbitrary reformats will be
5940 returned with a request to re-formatting / split it.
5942 * If you modify existing code, make sure that your new code does not
5943 add to the memory footprint of the code ;-) Small is beautiful!
5944 When adding new features, these should compile conditionally only
5945 (using #ifdef), and the resulting code with the new feature
5946 disabled must not need more memory than the old code without your
5949 * Remember that there is a size limit of 100 kB per message on the
5950 u-boot mailing list. Bigger patches will be moderated. If they are
5951 reasonable and not too big, they will be acknowledged. But patches
5952 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob