2 # (C) Copyright 2000 - 2013
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
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 - Generic CPU options:
427 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
429 Defines the endianess of the CPU. Implementation of those
430 values is arch specific.
433 Freescale DDR driver in use. This type of DDR controller is
434 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
437 CONFIG_SYS_FSL_DDR_ADDR
438 Freescale DDR memory-mapped register base.
440 CONFIG_SYS_FSL_DDR_EMU
441 Specify emulator support for DDR. Some DDR features such as
442 deskew training are not available.
444 CONFIG_SYS_FSL_DDRC_GEN1
445 Freescale DDR1 controller.
447 CONFIG_SYS_FSL_DDRC_GEN2
448 Freescale DDR2 controller.
450 CONFIG_SYS_FSL_DDRC_GEN3
451 Freescale DDR3 controller.
453 CONFIG_SYS_FSL_DDRC_ARM_GEN3
454 Freescale DDR3 controller for ARM-based SoCs.
457 Board config to use DDR1. It can be enabled for SoCs with
458 Freescale DDR1 or DDR2 controllers, depending on the board
462 Board config to use DDR2. It can be eanbeld for SoCs with
463 Freescale DDR2 or DDR3 controllers, depending on the board
467 Board config to use DDR3. It can be enabled for SoCs with
468 Freescale DDR3 controllers.
470 - Intel Monahans options:
471 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
473 Defines the Monahans run mode to oscillator
474 ratio. Valid values are 8, 16, 24, 31. The core
475 frequency is this value multiplied by 13 MHz.
477 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
479 Defines the Monahans turbo mode to oscillator
480 ratio. Valid values are 1 (default if undefined) and
481 2. The core frequency as calculated above is multiplied
485 CONFIG_SYS_INIT_SP_OFFSET
487 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
488 pointer. This is needed for the temporary stack before
491 CONFIG_SYS_MIPS_CACHE_MODE
493 Cache operation mode for the MIPS CPU.
494 See also arch/mips/include/asm/mipsregs.h.
496 CONF_CM_CACHABLE_NO_WA
499 CONF_CM_CACHABLE_NONCOHERENT
503 CONF_CM_CACHABLE_ACCELERATED
505 CONFIG_SYS_XWAY_EBU_BOOTCFG
507 Special option for Lantiq XWAY SoCs for booting from NOR flash.
508 See also arch/mips/cpu/mips32/start.S.
510 CONFIG_XWAY_SWAP_BYTES
512 Enable compilation of tools/xway-swap-bytes needed for Lantiq
513 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
514 be swapped if a flash programmer is used.
517 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
519 Select high exception vectors of the ARM core, e.g., do not
520 clear the V bit of the c1 register of CP15.
522 CONFIG_SYS_THUMB_BUILD
524 Use this flag to build U-Boot using the Thumb instruction
525 set for ARM architectures. Thumb instruction set provides
526 better code density. For ARM architectures that support
527 Thumb2 this flag will result in Thumb2 code generated by
530 CONFIG_ARM_ERRATA_716044
531 CONFIG_ARM_ERRATA_742230
532 CONFIG_ARM_ERRATA_743622
533 CONFIG_ARM_ERRATA_751472
535 If set, the workarounds for these ARM errata are applied early
536 during U-Boot startup. Note that these options force the
537 workarounds to be applied; no CPU-type/version detection
538 exists, unlike the similar options in the Linux kernel. Do not
539 set these options unless they apply!
544 The frequency of the timer returned by get_timer().
545 get_timer() must operate in milliseconds and this CONFIG
546 option must be set to 1000.
548 - Linux Kernel Interface:
551 U-Boot stores all clock information in Hz
552 internally. For binary compatibility with older Linux
553 kernels (which expect the clocks passed in the
554 bd_info data to be in MHz) the environment variable
555 "clocks_in_mhz" can be defined so that U-Boot
556 converts clock data to MHZ before passing it to the
558 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
559 "clocks_in_mhz=1" is automatically included in the
562 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
564 When transferring memsize parameter to linux, some versions
565 expect it to be in bytes, others in MB.
566 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
570 New kernel versions are expecting firmware settings to be
571 passed using flattened device trees (based on open firmware
575 * New libfdt-based support
576 * Adds the "fdt" command
577 * The bootm command automatically updates the fdt
579 OF_CPU - The proper name of the cpus node (only required for
580 MPC512X and MPC5xxx based boards).
581 OF_SOC - The proper name of the soc node (only required for
582 MPC512X and MPC5xxx based boards).
583 OF_TBCLK - The timebase frequency.
584 OF_STDOUT_PATH - The path to the console device
586 boards with QUICC Engines require OF_QE to set UCC MAC
589 CONFIG_OF_BOARD_SETUP
591 Board code has addition modification that it wants to make
592 to the flat device tree before handing it off to the kernel
596 This define fills in the correct boot CPU in the boot
597 param header, the default value is zero if undefined.
601 U-Boot can detect if an IDE device is present or not.
602 If not, and this new config option is activated, U-Boot
603 removes the ATA node from the DTS before booting Linux,
604 so the Linux IDE driver does not probe the device and
605 crash. This is needed for buggy hardware (uc101) where
606 no pull down resistor is connected to the signal IDE5V_DD7.
608 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
610 This setting is mandatory for all boards that have only one
611 machine type and must be used to specify the machine type
612 number as it appears in the ARM machine registry
613 (see http://www.arm.linux.org.uk/developer/machines/).
614 Only boards that have multiple machine types supported
615 in a single configuration file and the machine type is
616 runtime discoverable, do not have to use this setting.
618 - vxWorks boot parameters:
620 bootvx constructs a valid bootline using the following
621 environments variables: bootfile, ipaddr, serverip, hostname.
622 It loads the vxWorks image pointed bootfile.
624 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
625 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
626 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
627 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
629 CONFIG_SYS_VXWORKS_ADD_PARAMS
631 Add it at the end of the bootline. E.g "u=username pw=secret"
633 Note: If a "bootargs" environment is defined, it will overwride
634 the defaults discussed just above.
636 - Cache Configuration:
637 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
638 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
639 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
641 - Cache Configuration for ARM:
642 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
644 CONFIG_SYS_PL310_BASE - Physical base address of PL310
645 controller register space
650 Define this if you want support for Amba PrimeCell PL010 UARTs.
654 Define this if you want support for Amba PrimeCell PL011 UARTs.
658 If you have Amba PrimeCell PL011 UARTs, set this variable to
659 the clock speed of the UARTs.
663 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
664 define this to a list of base addresses for each (supported)
665 port. See e.g. include/configs/versatile.h
667 CONFIG_PL011_SERIAL_RLCR
669 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
670 have separate receive and transmit line control registers. Set
671 this variable to initialize the extra register.
673 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
675 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
676 boot loader that has already initialized the UART. Define this
677 variable to flush the UART at init time.
681 Depending on board, define exactly one serial port
682 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
683 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
684 console by defining CONFIG_8xx_CONS_NONE
686 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
687 port routines must be defined elsewhere
688 (i.e. serial_init(), serial_getc(), ...)
691 Enables console device for a color framebuffer. Needs following
692 defines (cf. smiLynxEM, i8042)
693 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
695 VIDEO_HW_RECTFILL graphic chip supports
698 VIDEO_HW_BITBLT graphic chip supports
699 bit-blit (cf. smiLynxEM)
700 VIDEO_VISIBLE_COLS visible pixel columns
702 VIDEO_VISIBLE_ROWS visible pixel rows
703 VIDEO_PIXEL_SIZE bytes per pixel
704 VIDEO_DATA_FORMAT graphic data format
705 (0-5, cf. cfb_console.c)
706 VIDEO_FB_ADRS framebuffer address
707 VIDEO_KBD_INIT_FCT keyboard int fct
708 (i.e. i8042_kbd_init())
709 VIDEO_TSTC_FCT test char fct
711 VIDEO_GETC_FCT get char fct
713 CONFIG_CONSOLE_CURSOR cursor drawing on/off
714 (requires blink timer
716 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
717 CONFIG_CONSOLE_TIME display time/date info in
719 (requires CONFIG_CMD_DATE)
720 CONFIG_VIDEO_LOGO display Linux logo in
722 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
723 linux_logo.h for logo.
724 Requires CONFIG_VIDEO_LOGO
725 CONFIG_CONSOLE_EXTRA_INFO
726 additional board info beside
729 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
730 a limited number of ANSI escape sequences (cursor control,
731 erase functions and limited graphics rendition control).
733 When CONFIG_CFB_CONSOLE is defined, video console is
734 default i/o. Serial console can be forced with
735 environment 'console=serial'.
737 When CONFIG_SILENT_CONSOLE is defined, all console
738 messages (by U-Boot and Linux!) can be silenced with
739 the "silent" environment variable. See
740 doc/README.silent for more information.
742 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
744 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
748 CONFIG_BAUDRATE - in bps
749 Select one of the baudrates listed in
750 CONFIG_SYS_BAUDRATE_TABLE, see below.
751 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
753 - Console Rx buffer length
754 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
755 the maximum receive buffer length for the SMC.
756 This option is actual only for 82xx and 8xx possible.
757 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
758 must be defined, to setup the maximum idle timeout for
761 - Pre-Console Buffer:
762 Prior to the console being initialised (i.e. serial UART
763 initialised etc) all console output is silently discarded.
764 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
765 buffer any console messages prior to the console being
766 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
767 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
768 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
769 bytes are output before the console is initialised, the
770 earlier bytes are discarded.
772 'Sane' compilers will generate smaller code if
773 CONFIG_PRE_CON_BUF_SZ is a power of 2
775 - Safe printf() functions
776 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
777 the printf() functions. These are defined in
778 include/vsprintf.h and include snprintf(), vsnprintf() and
779 so on. Code size increase is approximately 300-500 bytes.
780 If this option is not given then these functions will
781 silently discard their buffer size argument - this means
782 you are not getting any overflow checking in this case.
784 - Boot Delay: CONFIG_BOOTDELAY - in seconds
785 Delay before automatically booting the default image;
786 set to -1 to disable autoboot.
787 set to -2 to autoboot with no delay and not check for abort
788 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
790 See doc/README.autoboot for these options that
791 work with CONFIG_BOOTDELAY. None are required.
792 CONFIG_BOOT_RETRY_TIME
793 CONFIG_BOOT_RETRY_MIN
794 CONFIG_AUTOBOOT_KEYED
795 CONFIG_AUTOBOOT_PROMPT
796 CONFIG_AUTOBOOT_DELAY_STR
797 CONFIG_AUTOBOOT_STOP_STR
798 CONFIG_AUTOBOOT_DELAY_STR2
799 CONFIG_AUTOBOOT_STOP_STR2
800 CONFIG_ZERO_BOOTDELAY_CHECK
801 CONFIG_RESET_TO_RETRY
805 Only needed when CONFIG_BOOTDELAY is enabled;
806 define a command string that is automatically executed
807 when no character is read on the console interface
808 within "Boot Delay" after reset.
811 This can be used to pass arguments to the bootm
812 command. The value of CONFIG_BOOTARGS goes into the
813 environment value "bootargs".
815 CONFIG_RAMBOOT and CONFIG_NFSBOOT
816 The value of these goes into the environment as
817 "ramboot" and "nfsboot" respectively, and can be used
818 as a convenience, when switching between booting from
824 When this option is #defined, the existence of the
825 environment variable "preboot" will be checked
826 immediately before starting the CONFIG_BOOTDELAY
827 countdown and/or running the auto-boot command resp.
828 entering interactive mode.
830 This feature is especially useful when "preboot" is
831 automatically generated or modified. For an example
832 see the LWMON board specific code: here "preboot" is
833 modified when the user holds down a certain
834 combination of keys on the (special) keyboard when
837 - Serial Download Echo Mode:
839 If defined to 1, all characters received during a
840 serial download (using the "loads" command) are
841 echoed back. This might be needed by some terminal
842 emulations (like "cu"), but may as well just take
843 time on others. This setting #define's the initial
844 value of the "loads_echo" environment variable.
846 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
848 Select one of the baudrates listed in
849 CONFIG_SYS_BAUDRATE_TABLE, see below.
852 Monitor commands can be included or excluded
853 from the build by using the #include files
854 <config_cmd_all.h> and #undef'ing unwanted
855 commands, or using <config_cmd_default.h>
856 and augmenting with additional #define's
859 The default command configuration includes all commands
860 except those marked below with a "*".
862 CONFIG_CMD_ASKENV * ask for env variable
863 CONFIG_CMD_BDI bdinfo
864 CONFIG_CMD_BEDBUG * Include BedBug Debugger
865 CONFIG_CMD_BMP * BMP support
866 CONFIG_CMD_BSP * Board specific commands
867 CONFIG_CMD_BOOTD bootd
868 CONFIG_CMD_CACHE * icache, dcache
869 CONFIG_CMD_CONSOLE coninfo
870 CONFIG_CMD_CRC32 * crc32
871 CONFIG_CMD_DATE * support for RTC, date/time...
872 CONFIG_CMD_DHCP * DHCP support
873 CONFIG_CMD_DIAG * Diagnostics
874 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
875 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
876 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
877 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
878 CONFIG_CMD_DTT * Digital Therm and Thermostat
879 CONFIG_CMD_ECHO echo arguments
880 CONFIG_CMD_EDITENV edit env variable
881 CONFIG_CMD_EEPROM * EEPROM read/write support
882 CONFIG_CMD_ELF * bootelf, bootvx
883 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
884 CONFIG_CMD_ENV_FLAGS * display details about env flags
885 CONFIG_CMD_ENV_EXISTS * check existence of env variable
886 CONFIG_CMD_EXPORTENV * export the environment
887 CONFIG_CMD_EXT2 * ext2 command support
888 CONFIG_CMD_EXT4 * ext4 command support
889 CONFIG_CMD_SAVEENV saveenv
890 CONFIG_CMD_FDC * Floppy Disk Support
891 CONFIG_CMD_FAT * FAT command support
892 CONFIG_CMD_FDOS * Dos diskette Support
893 CONFIG_CMD_FLASH flinfo, erase, protect
894 CONFIG_CMD_FPGA FPGA device initialization support
895 CONFIG_CMD_FUSE * Device fuse support
896 CONFIG_CMD_GETTIME * Get time since boot
897 CONFIG_CMD_GO * the 'go' command (exec code)
898 CONFIG_CMD_GREPENV * search environment
899 CONFIG_CMD_HASH * calculate hash / digest
900 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
901 CONFIG_CMD_I2C * I2C serial bus support
902 CONFIG_CMD_IDE * IDE harddisk support
903 CONFIG_CMD_IMI iminfo
904 CONFIG_CMD_IMLS List all images found in NOR flash
905 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
906 CONFIG_CMD_IMMAP * IMMR dump support
907 CONFIG_CMD_IMPORTENV * import an environment
908 CONFIG_CMD_INI * import data from an ini file into the env
909 CONFIG_CMD_IRQ * irqinfo
910 CONFIG_CMD_ITEST Integer/string test of 2 values
911 CONFIG_CMD_JFFS2 * JFFS2 Support
912 CONFIG_CMD_KGDB * kgdb
913 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
914 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
916 CONFIG_CMD_LOADB loadb
917 CONFIG_CMD_LOADS loads
918 CONFIG_CMD_MD5SUM * print md5 message digest
919 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
920 CONFIG_CMD_MEMINFO * Display detailed memory information
921 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
923 CONFIG_CMD_MEMTEST * mtest
924 CONFIG_CMD_MISC Misc functions like sleep etc
925 CONFIG_CMD_MMC * MMC memory mapped support
926 CONFIG_CMD_MII * MII utility commands
927 CONFIG_CMD_MTDPARTS * MTD partition support
928 CONFIG_CMD_NAND * NAND support
929 CONFIG_CMD_NET bootp, tftpboot, rarpboot
930 CONFIG_CMD_NFS NFS support
931 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
932 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
933 CONFIG_CMD_PCI * pciinfo
934 CONFIG_CMD_PCMCIA * PCMCIA support
935 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
937 CONFIG_CMD_PORTIO * Port I/O
938 CONFIG_CMD_READ * Read raw data from partition
939 CONFIG_CMD_REGINFO * Register dump
940 CONFIG_CMD_RUN run command in env variable
941 CONFIG_CMD_SANDBOX * sb command to access sandbox features
942 CONFIG_CMD_SAVES * save S record dump
943 CONFIG_CMD_SCSI * SCSI Support
944 CONFIG_CMD_SDRAM * print SDRAM configuration information
945 (requires CONFIG_CMD_I2C)
946 CONFIG_CMD_SETGETDCR Support for DCR Register access
948 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
949 CONFIG_CMD_SHA1SUM * print sha1 memory digest
950 (requires CONFIG_CMD_MEMORY)
951 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
952 CONFIG_CMD_SOURCE "source" command Support
953 CONFIG_CMD_SPI * SPI serial bus support
954 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
955 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
956 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
957 CONFIG_CMD_TIMER * access to the system tick timer
958 CONFIG_CMD_USB * USB support
959 CONFIG_CMD_CDP * Cisco Discover Protocol support
960 CONFIG_CMD_MFSL * Microblaze FSL support
961 CONFIG_CMD_XIMG Load part of Multi Image
964 EXAMPLE: If you want all functions except of network
965 support you can write:
967 #include "config_cmd_all.h"
968 #undef CONFIG_CMD_NET
971 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
973 Note: Don't enable the "icache" and "dcache" commands
974 (configuration option CONFIG_CMD_CACHE) unless you know
975 what you (and your U-Boot users) are doing. Data
976 cache cannot be enabled on systems like the 8xx or
977 8260 (where accesses to the IMMR region must be
978 uncached), and it cannot be disabled on all other
979 systems where we (mis-) use the data cache to hold an
980 initial stack and some data.
983 XXX - this list needs to get updated!
985 - Regular expression support:
987 If this variable is defined, U-Boot is linked against
988 the SLRE (Super Light Regular Expression) library,
989 which adds regex support to some commands, as for
990 example "env grep" and "setexpr".
994 If this variable is defined, U-Boot will use a device tree
995 to configure its devices, instead of relying on statically
996 compiled #defines in the board file. This option is
997 experimental and only available on a few boards. The device
998 tree is available in the global data as gd->fdt_blob.
1000 U-Boot needs to get its device tree from somewhere. This can
1001 be done using one of the two options below:
1004 If this variable is defined, U-Boot will embed a device tree
1005 binary in its image. This device tree file should be in the
1006 board directory and called <soc>-<board>.dts. The binary file
1007 is then picked up in board_init_f() and made available through
1008 the global data structure as gd->blob.
1011 If this variable is defined, U-Boot will build a device tree
1012 binary. It will be called u-boot.dtb. Architecture-specific
1013 code will locate it at run-time. Generally this works by:
1015 cat u-boot.bin u-boot.dtb >image.bin
1017 and in fact, U-Boot does this for you, creating a file called
1018 u-boot-dtb.bin which is useful in the common case. You can
1019 still use the individual files if you need something more
1024 If this variable is defined, it enables watchdog
1025 support for the SoC. There must be support in the SoC
1026 specific code for a watchdog. For the 8xx and 8260
1027 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1028 register. When supported for a specific SoC is
1029 available, then no further board specific code should
1030 be needed to use it.
1033 When using a watchdog circuitry external to the used
1034 SoC, then define this variable and provide board
1035 specific code for the "hw_watchdog_reset" function.
1038 CONFIG_VERSION_VARIABLE
1039 If this variable is defined, an environment variable
1040 named "ver" is created by U-Boot showing the U-Boot
1041 version as printed by the "version" command.
1042 Any change to this variable will be reverted at the
1047 When CONFIG_CMD_DATE is selected, the type of the RTC
1048 has to be selected, too. Define exactly one of the
1051 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1052 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1053 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1054 CONFIG_RTC_MC146818 - use MC146818 RTC
1055 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1056 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1057 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1058 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1059 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1060 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1061 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1062 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1065 Note that if the RTC uses I2C, then the I2C interface
1066 must also be configured. See I2C Support, below.
1069 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1071 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1072 chip-ngpio pairs that tell the PCA953X driver the number of
1073 pins supported by a particular chip.
1075 Note that if the GPIO device uses I2C, then the I2C interface
1076 must also be configured. See I2C Support, below.
1078 - Timestamp Support:
1080 When CONFIG_TIMESTAMP is selected, the timestamp
1081 (date and time) of an image is printed by image
1082 commands like bootm or iminfo. This option is
1083 automatically enabled when you select CONFIG_CMD_DATE .
1085 - Partition Labels (disklabels) Supported:
1086 Zero or more of the following:
1087 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1088 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1089 Intel architecture, USB sticks, etc.
1090 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1091 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1092 bootloader. Note 2TB partition limit; see
1094 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1096 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1097 CONFIG_CMD_SCSI) you must configure support for at
1098 least one non-MTD partition type as well.
1101 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1102 board configurations files but used nowhere!
1104 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1105 be performed by calling the function
1106 ide_set_reset(int reset)
1107 which has to be defined in a board specific file
1112 Set this to enable ATAPI support.
1117 Set this to enable support for disks larger than 137GB
1118 Also look at CONFIG_SYS_64BIT_LBA.
1119 Whithout these , LBA48 support uses 32bit variables and will 'only'
1120 support disks up to 2.1TB.
1122 CONFIG_SYS_64BIT_LBA:
1123 When enabled, makes the IDE subsystem use 64bit sector addresses.
1127 At the moment only there is only support for the
1128 SYM53C8XX SCSI controller; define
1129 CONFIG_SCSI_SYM53C8XX to enable it.
1131 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1132 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1133 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1134 maximum numbers of LUNs, SCSI ID's and target
1136 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1138 The environment variable 'scsidevs' is set to the number of
1139 SCSI devices found during the last scan.
1141 - NETWORK Support (PCI):
1143 Support for Intel 8254x/8257x gigabit chips.
1146 Utility code for direct access to the SPI bus on Intel 8257x.
1147 This does not do anything useful unless you set at least one
1148 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1150 CONFIG_E1000_SPI_GENERIC
1151 Allow generic access to the SPI bus on the Intel 8257x, for
1152 example with the "sspi" command.
1155 Management command for E1000 devices. When used on devices
1156 with SPI support you can reprogram the EEPROM from U-Boot.
1158 CONFIG_E1000_FALLBACK_MAC
1159 default MAC for empty EEPROM after production.
1162 Support for Intel 82557/82559/82559ER chips.
1163 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1164 write routine for first time initialisation.
1167 Support for Digital 2114x chips.
1168 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1169 modem chip initialisation (KS8761/QS6611).
1172 Support for National dp83815 chips.
1175 Support for National dp8382[01] gigabit chips.
1177 - NETWORK Support (other):
1179 CONFIG_DRIVER_AT91EMAC
1180 Support for AT91RM9200 EMAC.
1183 Define this to use reduced MII inteface
1185 CONFIG_DRIVER_AT91EMAC_QUIET
1186 If this defined, the driver is quiet.
1187 The driver doen't show link status messages.
1189 CONFIG_CALXEDA_XGMAC
1190 Support for the Calxeda XGMAC device
1193 Support for SMSC's LAN91C96 chips.
1195 CONFIG_LAN91C96_BASE
1196 Define this to hold the physical address
1197 of the LAN91C96's I/O space
1199 CONFIG_LAN91C96_USE_32_BIT
1200 Define this to enable 32 bit addressing
1203 Support for SMSC's LAN91C111 chip
1205 CONFIG_SMC91111_BASE
1206 Define this to hold the physical address
1207 of the device (I/O space)
1209 CONFIG_SMC_USE_32_BIT
1210 Define this if data bus is 32 bits
1212 CONFIG_SMC_USE_IOFUNCS
1213 Define this to use i/o functions instead of macros
1214 (some hardware wont work with macros)
1216 CONFIG_DRIVER_TI_EMAC
1217 Support for davinci emac
1219 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1220 Define this if you have more then 3 PHYs.
1223 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1225 CONFIG_FTGMAC100_EGIGA
1226 Define this to use GE link update with gigabit PHY.
1227 Define this if FTGMAC100 is connected to gigabit PHY.
1228 If your system has 10/100 PHY only, it might not occur
1229 wrong behavior. Because PHY usually return timeout or
1230 useless data when polling gigabit status and gigabit
1231 control registers. This behavior won't affect the
1232 correctnessof 10/100 link speed update.
1235 Support for SMSC's LAN911x and LAN921x chips
1238 Define this to hold the physical address
1239 of the device (I/O space)
1241 CONFIG_SMC911X_32_BIT
1242 Define this if data bus is 32 bits
1244 CONFIG_SMC911X_16_BIT
1245 Define this if data bus is 16 bits. If your processor
1246 automatically converts one 32 bit word to two 16 bit
1247 words you may also try CONFIG_SMC911X_32_BIT.
1250 Support for Renesas on-chip Ethernet controller
1252 CONFIG_SH_ETHER_USE_PORT
1253 Define the number of ports to be used
1255 CONFIG_SH_ETHER_PHY_ADDR
1256 Define the ETH PHY's address
1258 CONFIG_SH_ETHER_CACHE_WRITEBACK
1259 If this option is set, the driver enables cache flush.
1263 Support TPM devices.
1266 Support for i2c bus TPM devices. Only one device
1267 per system is supported at this time.
1269 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1270 Define the the i2c bus number for the TPM device
1272 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1273 Define the TPM's address on the i2c bus
1275 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1276 Define the burst count bytes upper limit
1278 CONFIG_TPM_ATMEL_TWI
1279 Support for Atmel TWI TPM device. Requires I2C support.
1282 Support for generic parallel port TPM devices. Only one device
1283 per system is supported at this time.
1285 CONFIG_TPM_TIS_BASE_ADDRESS
1286 Base address where the generic TPM device is mapped
1287 to. Contemporary x86 systems usually map it at
1291 Add tpm monitor functions.
1292 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1293 provides monitor access to authorized functions.
1296 Define this to enable the TPM support library which provides
1297 functional interfaces to some TPM commands.
1298 Requires support for a TPM device.
1300 CONFIG_TPM_AUTH_SESSIONS
1301 Define this to enable authorized functions in the TPM library.
1302 Requires CONFIG_TPM and CONFIG_SHA1.
1305 At the moment only the UHCI host controller is
1306 supported (PIP405, MIP405, MPC5200); define
1307 CONFIG_USB_UHCI to enable it.
1308 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1309 and define CONFIG_USB_STORAGE to enable the USB
1312 Supported are USB Keyboards and USB Floppy drives
1314 MPC5200 USB requires additional defines:
1316 for 528 MHz Clock: 0x0001bbbb
1320 for differential drivers: 0x00001000
1321 for single ended drivers: 0x00005000
1322 for differential drivers on PSC3: 0x00000100
1323 for single ended drivers on PSC3: 0x00004100
1324 CONFIG_SYS_USB_EVENT_POLL
1325 May be defined to allow interrupt polling
1326 instead of using asynchronous interrupts
1328 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1329 txfilltuning field in the EHCI controller on reset.
1331 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1332 interval for usb hub power-on delay.(minimum 100msec)
1335 Define the below if you wish to use the USB console.
1336 Once firmware is rebuilt from a serial console issue the
1337 command "setenv stdin usbtty; setenv stdout usbtty" and
1338 attach your USB cable. The Unix command "dmesg" should print
1339 it has found a new device. The environment variable usbtty
1340 can be set to gserial or cdc_acm to enable your device to
1341 appear to a USB host as a Linux gserial device or a
1342 Common Device Class Abstract Control Model serial device.
1343 If you select usbtty = gserial you should be able to enumerate
1345 # modprobe usbserial vendor=0xVendorID product=0xProductID
1346 else if using cdc_acm, simply setting the environment
1347 variable usbtty to be cdc_acm should suffice. The following
1348 might be defined in YourBoardName.h
1351 Define this to build a UDC device
1354 Define this to have a tty type of device available to
1355 talk to the UDC device
1358 Define this to enable the high speed support for usb
1359 device and usbtty. If this feature is enabled, a routine
1360 int is_usbd_high_speed(void)
1361 also needs to be defined by the driver to dynamically poll
1362 whether the enumeration has succeded at high speed or full
1365 CONFIG_SYS_CONSOLE_IS_IN_ENV
1366 Define this if you want stdin, stdout &/or stderr to
1370 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1371 Derive USB clock from external clock "blah"
1372 - CONFIG_SYS_USB_EXTC_CLK 0x02
1374 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1375 Derive USB clock from brgclk
1376 - CONFIG_SYS_USB_BRG_CLK 0x04
1378 If you have a USB-IF assigned VendorID then you may wish to
1379 define your own vendor specific values either in BoardName.h
1380 or directly in usbd_vendor_info.h. If you don't define
1381 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1382 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1383 should pretend to be a Linux device to it's target host.
1385 CONFIG_USBD_MANUFACTURER
1386 Define this string as the name of your company for
1387 - CONFIG_USBD_MANUFACTURER "my company"
1389 CONFIG_USBD_PRODUCT_NAME
1390 Define this string as the name of your product
1391 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1393 CONFIG_USBD_VENDORID
1394 Define this as your assigned Vendor ID from the USB
1395 Implementors Forum. This *must* be a genuine Vendor ID
1396 to avoid polluting the USB namespace.
1397 - CONFIG_USBD_VENDORID 0xFFFF
1399 CONFIG_USBD_PRODUCTID
1400 Define this as the unique Product ID
1402 - CONFIG_USBD_PRODUCTID 0xFFFF
1404 Some USB device drivers may need to check USB cable attachment.
1405 In this case you can enable following config in BoardName.h:
1406 CONFIG_USB_CABLE_CHECK
1407 This enables function definition:
1408 - usb_cable_connected() in include/usb.h
1409 Implementation of this function is board-specific.
1411 - ULPI Layer Support:
1412 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1413 the generic ULPI layer. The generic layer accesses the ULPI PHY
1414 via the platform viewport, so you need both the genric layer and
1415 the viewport enabled. Currently only Chipidea/ARC based
1416 viewport is supported.
1417 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1418 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1419 If your ULPI phy needs a different reference clock than the
1420 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1421 the appropriate value in Hz.
1424 The MMC controller on the Intel PXA is supported. To
1425 enable this define CONFIG_MMC. The MMC can be
1426 accessed from the boot prompt by mapping the device
1427 to physical memory similar to flash. Command line is
1428 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1429 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1432 Support for Renesas on-chip MMCIF controller
1434 CONFIG_SH_MMCIF_ADDR
1435 Define the base address of MMCIF registers
1438 Define the clock frequency for MMCIF
1440 - USB Device Firmware Update (DFU) class support:
1442 This enables the USB portion of the DFU USB class
1445 This enables the command "dfu" which is used to have
1446 U-Boot create a DFU class device via USB. This command
1447 requires that the "dfu_alt_info" environment variable be
1448 set and define the alt settings to expose to the host.
1451 This enables support for exposing (e)MMC devices via DFU.
1454 This enables support for exposing NAND devices via DFU.
1457 This enables support for exposing RAM via DFU.
1458 Note: DFU spec refer to non-volatile memory usage, but
1459 allow usages beyond the scope of spec - here RAM usage,
1460 one that would help mostly the developer.
1462 CONFIG_SYS_DFU_DATA_BUF_SIZE
1463 Dfu transfer uses a buffer before writing data to the
1464 raw storage device. Make the size (in bytes) of this buffer
1465 configurable. The size of this buffer is also configurable
1466 through the "dfu_bufsiz" environment variable.
1468 CONFIG_SYS_DFU_MAX_FILE_SIZE
1469 When updating files rather than the raw storage device,
1470 we use a static buffer to copy the file into and then write
1471 the buffer once we've been given the whole file. Define
1472 this to the maximum filesize (in bytes) for the buffer.
1473 Default is 4 MiB if undefined.
1475 - Journaling Flash filesystem support:
1476 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1477 CONFIG_JFFS2_NAND_DEV
1478 Define these for a default partition on a NAND device
1480 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1481 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1482 Define these for a default partition on a NOR device
1484 CONFIG_SYS_JFFS_CUSTOM_PART
1485 Define this to create an own partition. You have to provide a
1486 function struct part_info* jffs2_part_info(int part_num)
1488 If you define only one JFFS2 partition you may also want to
1489 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1490 to disable the command chpart. This is the default when you
1491 have not defined a custom partition
1493 - FAT(File Allocation Table) filesystem write function support:
1496 Define this to enable support for saving memory data as a
1497 file in FAT formatted partition.
1499 This will also enable the command "fatwrite" enabling the
1500 user to write files to FAT.
1502 CBFS (Coreboot Filesystem) support
1505 Define this to enable support for reading from a Coreboot
1506 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1512 Define this to enable standard (PC-Style) keyboard
1516 Standard PC keyboard driver with US (is default) and
1517 GERMAN key layout (switch via environment 'keymap=de') support.
1518 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1519 for cfb_console. Supports cursor blinking.
1522 Enables a Chrome OS keyboard using the CROS_EC interface.
1523 This uses CROS_EC to communicate with a second microcontroller
1524 which provides key scans on request.
1529 Define this to enable video support (for output to
1532 CONFIG_VIDEO_CT69000
1534 Enable Chips & Technologies 69000 Video chip
1536 CONFIG_VIDEO_SMI_LYNXEM
1537 Enable Silicon Motion SMI 712/710/810 Video chip. The
1538 video output is selected via environment 'videoout'
1539 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1542 For the CT69000 and SMI_LYNXEM drivers, videomode is
1543 selected via environment 'videomode'. Two different ways
1545 - "videomode=num" 'num' is a standard LiLo mode numbers.
1546 Following standard modes are supported (* is default):
1548 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1549 -------------+---------------------------------------------
1550 8 bits | 0x301* 0x303 0x305 0x161 0x307
1551 15 bits | 0x310 0x313 0x316 0x162 0x319
1552 16 bits | 0x311 0x314 0x317 0x163 0x31A
1553 24 bits | 0x312 0x315 0x318 ? 0x31B
1554 -------------+---------------------------------------------
1555 (i.e. setenv videomode 317; saveenv; reset;)
1557 - "videomode=bootargs" all the video parameters are parsed
1558 from the bootargs. (See drivers/video/videomodes.c)
1561 CONFIG_VIDEO_SED13806
1562 Enable Epson SED13806 driver. This driver supports 8bpp
1563 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1564 or CONFIG_VIDEO_SED13806_16BPP
1567 Enable the Freescale DIU video driver. Reference boards for
1568 SOCs that have a DIU should define this macro to enable DIU
1569 support, and should also define these other macros:
1575 CONFIG_VIDEO_SW_CURSOR
1576 CONFIG_VGA_AS_SINGLE_DEVICE
1578 CONFIG_VIDEO_BMP_LOGO
1580 The DIU driver will look for the 'video-mode' environment
1581 variable, and if defined, enable the DIU as a console during
1582 boot. See the documentation file README.video for a
1583 description of this variable.
1587 Enable the VGA video / BIOS for x86. The alternative if you
1588 are using coreboot is to use the coreboot frame buffer
1595 Define this to enable a custom keyboard support.
1596 This simply calls drv_keyboard_init() which must be
1597 defined in your board-specific files.
1598 The only board using this so far is RBC823.
1600 - LCD Support: CONFIG_LCD
1602 Define this to enable LCD support (for output to LCD
1603 display); also select one of the supported displays
1604 by defining one of these:
1608 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1610 CONFIG_NEC_NL6448AC33:
1612 NEC NL6448AC33-18. Active, color, single scan.
1614 CONFIG_NEC_NL6448BC20
1616 NEC NL6448BC20-08. 6.5", 640x480.
1617 Active, color, single scan.
1619 CONFIG_NEC_NL6448BC33_54
1621 NEC NL6448BC33-54. 10.4", 640x480.
1622 Active, color, single scan.
1626 Sharp 320x240. Active, color, single scan.
1627 It isn't 16x9, and I am not sure what it is.
1629 CONFIG_SHARP_LQ64D341
1631 Sharp LQ64D341 display, 640x480.
1632 Active, color, single scan.
1636 HLD1045 display, 640x480.
1637 Active, color, single scan.
1641 Optrex CBL50840-2 NF-FW 99 22 M5
1643 Hitachi LMG6912RPFC-00T
1647 320x240. Black & white.
1649 Normally display is black on white background; define
1650 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1652 CONFIG_LCD_ALIGNMENT
1654 Normally the LCD is page-aligned (tyically 4KB). If this is
1655 defined then the LCD will be aligned to this value instead.
1656 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1657 here, since it is cheaper to change data cache settings on
1658 a per-section basis.
1660 CONFIG_CONSOLE_SCROLL_LINES
1662 When the console need to be scrolled, this is the number of
1663 lines to scroll by. It defaults to 1. Increasing this makes
1664 the console jump but can help speed up operation when scrolling
1669 Support drawing of RLE8-compressed bitmaps on the LCD.
1673 Enables an 'i2c edid' command which can read EDID
1674 information over I2C from an attached LCD display.
1676 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1678 If this option is set, the environment is checked for
1679 a variable "splashimage". If found, the usual display
1680 of logo, copyright and system information on the LCD
1681 is suppressed and the BMP image at the address
1682 specified in "splashimage" is loaded instead. The
1683 console is redirected to the "nulldev", too. This
1684 allows for a "silent" boot where a splash screen is
1685 loaded very quickly after power-on.
1687 CONFIG_SPLASHIMAGE_GUARD
1689 If this option is set, then U-Boot will prevent the environment
1690 variable "splashimage" from being set to a problematic address
1691 (see README.displaying-bmps and README.arm-unaligned-accesses).
1692 This option is useful for targets where, due to alignment
1693 restrictions, an improperly aligned BMP image will cause a data
1694 abort. If you think you will not have problems with unaligned
1695 accesses (for example because your toolchain prevents them)
1696 there is no need to set this option.
1698 CONFIG_SPLASH_SCREEN_ALIGN
1700 If this option is set the splash image can be freely positioned
1701 on the screen. Environment variable "splashpos" specifies the
1702 position as "x,y". If a positive number is given it is used as
1703 number of pixel from left/top. If a negative number is given it
1704 is used as number of pixel from right/bottom. You can also
1705 specify 'm' for centering the image.
1708 setenv splashpos m,m
1709 => image at center of screen
1711 setenv splashpos 30,20
1712 => image at x = 30 and y = 20
1714 setenv splashpos -10,m
1715 => vertically centered image
1716 at x = dspWidth - bmpWidth - 9
1718 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1720 If this option is set, additionally to standard BMP
1721 images, gzipped BMP images can be displayed via the
1722 splashscreen support or the bmp command.
1724 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1726 If this option is set, 8-bit RLE compressed BMP images
1727 can be displayed via the splashscreen support or the
1730 - Do compresssing for memory range:
1733 If this option is set, it would use zlib deflate method
1734 to compress the specified memory at its best effort.
1736 - Compression support:
1739 Enabled by default to support gzip compressed images.
1743 If this option is set, support for bzip2 compressed
1744 images is included. If not, only uncompressed and gzip
1745 compressed images are supported.
1747 NOTE: the bzip2 algorithm requires a lot of RAM, so
1748 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1753 If this option is set, support for lzma compressed
1756 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1757 requires an amount of dynamic memory that is given by the
1760 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1762 Where lc and lp stand for, respectively, Literal context bits
1763 and Literal pos bits.
1765 This value is upper-bounded by 14MB in the worst case. Anyway,
1766 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1767 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1768 a very small buffer.
1770 Use the lzmainfo tool to determinate the lc and lp values and
1771 then calculate the amount of needed dynamic memory (ensuring
1772 the appropriate CONFIG_SYS_MALLOC_LEN value).
1776 If this option is set, support for LZO compressed images
1782 The address of PHY on MII bus.
1784 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1786 The clock frequency of the MII bus
1790 If this option is set, support for speed/duplex
1791 detection of gigabit PHY is included.
1793 CONFIG_PHY_RESET_DELAY
1795 Some PHY like Intel LXT971A need extra delay after
1796 reset before any MII register access is possible.
1797 For such PHY, set this option to the usec delay
1798 required. (minimum 300usec for LXT971A)
1800 CONFIG_PHY_CMD_DELAY (ppc4xx)
1802 Some PHY like Intel LXT971A need extra delay after
1803 command issued before MII status register can be read
1813 Define a default value for Ethernet address to use
1814 for the respective Ethernet interface, in case this
1815 is not determined automatically.
1820 Define a default value for the IP address to use for
1821 the default Ethernet interface, in case this is not
1822 determined through e.g. bootp.
1823 (Environment variable "ipaddr")
1825 - Server IP address:
1828 Defines a default value for the IP address of a TFTP
1829 server to contact when using the "tftboot" command.
1830 (Environment variable "serverip")
1832 CONFIG_KEEP_SERVERADDR
1834 Keeps the server's MAC address, in the env 'serveraddr'
1835 for passing to bootargs (like Linux's netconsole option)
1837 - Gateway IP address:
1840 Defines a default value for the IP address of the
1841 default router where packets to other networks are
1843 (Environment variable "gatewayip")
1848 Defines a default value for the subnet mask (or
1849 routing prefix) which is used to determine if an IP
1850 address belongs to the local subnet or needs to be
1851 forwarded through a router.
1852 (Environment variable "netmask")
1854 - Multicast TFTP Mode:
1857 Defines whether you want to support multicast TFTP as per
1858 rfc-2090; for example to work with atftp. Lets lots of targets
1859 tftp down the same boot image concurrently. Note: the Ethernet
1860 driver in use must provide a function: mcast() to join/leave a
1863 - BOOTP Recovery Mode:
1864 CONFIG_BOOTP_RANDOM_DELAY
1866 If you have many targets in a network that try to
1867 boot using BOOTP, you may want to avoid that all
1868 systems send out BOOTP requests at precisely the same
1869 moment (which would happen for instance at recovery
1870 from a power failure, when all systems will try to
1871 boot, thus flooding the BOOTP server. Defining
1872 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1873 inserted before sending out BOOTP requests. The
1874 following delays are inserted then:
1876 1st BOOTP request: delay 0 ... 1 sec
1877 2nd BOOTP request: delay 0 ... 2 sec
1878 3rd BOOTP request: delay 0 ... 4 sec
1880 BOOTP requests: delay 0 ... 8 sec
1882 - DHCP Advanced Options:
1883 You can fine tune the DHCP functionality by defining
1884 CONFIG_BOOTP_* symbols:
1886 CONFIG_BOOTP_SUBNETMASK
1887 CONFIG_BOOTP_GATEWAY
1888 CONFIG_BOOTP_HOSTNAME
1889 CONFIG_BOOTP_NISDOMAIN
1890 CONFIG_BOOTP_BOOTPATH
1891 CONFIG_BOOTP_BOOTFILESIZE
1894 CONFIG_BOOTP_SEND_HOSTNAME
1895 CONFIG_BOOTP_NTPSERVER
1896 CONFIG_BOOTP_TIMEOFFSET
1897 CONFIG_BOOTP_VENDOREX
1898 CONFIG_BOOTP_MAY_FAIL
1900 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1901 environment variable, not the BOOTP server.
1903 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1904 after the configured retry count, the call will fail
1905 instead of starting over. This can be used to fail over
1906 to Link-local IP address configuration if the DHCP server
1909 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1910 serverip from a DHCP server, it is possible that more
1911 than one DNS serverip is offered to the client.
1912 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1913 serverip will be stored in the additional environment
1914 variable "dnsip2". The first DNS serverip is always
1915 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1918 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1919 to do a dynamic update of a DNS server. To do this, they
1920 need the hostname of the DHCP requester.
1921 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1922 of the "hostname" environment variable is passed as
1923 option 12 to the DHCP server.
1925 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1927 A 32bit value in microseconds for a delay between
1928 receiving a "DHCP Offer" and sending the "DHCP Request".
1929 This fixes a problem with certain DHCP servers that don't
1930 respond 100% of the time to a "DHCP request". E.g. On an
1931 AT91RM9200 processor running at 180MHz, this delay needed
1932 to be *at least* 15,000 usec before a Windows Server 2003
1933 DHCP server would reply 100% of the time. I recommend at
1934 least 50,000 usec to be safe. The alternative is to hope
1935 that one of the retries will be successful but note that
1936 the DHCP timeout and retry process takes a longer than
1939 - Link-local IP address negotiation:
1940 Negotiate with other link-local clients on the local network
1941 for an address that doesn't require explicit configuration.
1942 This is especially useful if a DHCP server cannot be guaranteed
1943 to exist in all environments that the device must operate.
1945 See doc/README.link-local for more information.
1948 CONFIG_CDP_DEVICE_ID
1950 The device id used in CDP trigger frames.
1952 CONFIG_CDP_DEVICE_ID_PREFIX
1954 A two character string which is prefixed to the MAC address
1959 A printf format string which contains the ascii name of
1960 the port. Normally is set to "eth%d" which sets
1961 eth0 for the first Ethernet, eth1 for the second etc.
1963 CONFIG_CDP_CAPABILITIES
1965 A 32bit integer which indicates the device capabilities;
1966 0x00000010 for a normal host which does not forwards.
1970 An ascii string containing the version of the software.
1974 An ascii string containing the name of the platform.
1978 A 32bit integer sent on the trigger.
1980 CONFIG_CDP_POWER_CONSUMPTION
1982 A 16bit integer containing the power consumption of the
1983 device in .1 of milliwatts.
1985 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1987 A byte containing the id of the VLAN.
1989 - Status LED: CONFIG_STATUS_LED
1991 Several configurations allow to display the current
1992 status using a LED. For instance, the LED will blink
1993 fast while running U-Boot code, stop blinking as
1994 soon as a reply to a BOOTP request was received, and
1995 start blinking slow once the Linux kernel is running
1996 (supported by a status LED driver in the Linux
1997 kernel). Defining CONFIG_STATUS_LED enables this
2003 The status LED can be connected to a GPIO pin.
2004 In such cases, the gpio_led driver can be used as a
2005 status LED backend implementation. Define CONFIG_GPIO_LED
2006 to include the gpio_led driver in the U-Boot binary.
2008 CONFIG_GPIO_LED_INVERTED_TABLE
2009 Some GPIO connected LEDs may have inverted polarity in which
2010 case the GPIO high value corresponds to LED off state and
2011 GPIO low value corresponds to LED on state.
2012 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2013 with a list of GPIO LEDs that have inverted polarity.
2015 - CAN Support: CONFIG_CAN_DRIVER
2017 Defining CONFIG_CAN_DRIVER enables CAN driver support
2018 on those systems that support this (optional)
2019 feature, like the TQM8xxL modules.
2021 - I2C Support: CONFIG_SYS_I2C
2023 This enable the NEW i2c subsystem, and will allow you to use
2024 i2c commands at the u-boot command line (as long as you set
2025 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2026 based realtime clock chips or other i2c devices. See
2027 common/cmd_i2c.c for a description of the command line
2030 ported i2c driver to the new framework:
2031 - drivers/i2c/soft_i2c.c:
2032 - activate first bus with CONFIG_SYS_I2C_SOFT define
2033 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2034 for defining speed and slave address
2035 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2036 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2037 for defining speed and slave address
2038 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2039 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2040 for defining speed and slave address
2041 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2042 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2043 for defining speed and slave address
2045 - drivers/i2c/fsl_i2c.c:
2046 - activate i2c driver with CONFIG_SYS_I2C_FSL
2047 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2048 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2049 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2051 - If your board supports a second fsl i2c bus, define
2052 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2053 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2054 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2057 - drivers/i2c/tegra_i2c.c:
2058 - activate this driver with CONFIG_SYS_I2C_TEGRA
2059 - This driver adds 4 i2c buses with a fix speed from
2060 100000 and the slave addr 0!
2062 - drivers/i2c/ppc4xx_i2c.c
2063 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2064 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2065 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2067 - drivers/i2c/i2c_mxc.c
2068 - activate this driver with CONFIG_SYS_I2C_MXC
2069 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2070 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2071 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2072 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2073 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2074 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2075 If thoses defines are not set, default value is 100000
2076 for speed, and 0 for slave.
2078 - drivers/i2c/rcar_i2c.c:
2079 - activate this driver with CONFIG_SYS_I2C_RCAR
2080 - This driver adds 4 i2c buses
2082 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2083 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2084 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2085 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2086 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2087 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2088 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2089 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2090 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2092 - drivers/i2c/sh_i2c.c:
2093 - activate this driver with CONFIG_SYS_I2C_SH
2094 - This driver adds from 2 to 5 i2c buses
2096 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2097 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2098 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2099 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2100 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2101 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2102 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2103 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2104 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2105 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2106 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2107 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2108 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2110 - drivers/i2c/omap24xx_i2c.c
2111 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2112 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2113 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2114 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2115 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2116 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2117 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2118 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2119 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2120 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2121 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2123 - drivers/i2c/zynq_i2c.c
2124 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2125 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2126 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2130 CONFIG_SYS_NUM_I2C_BUSES
2131 Hold the number of i2c busses you want to use. If you
2132 don't use/have i2c muxes on your i2c bus, this
2133 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2136 CONFIG_SYS_I2C_DIRECT_BUS
2137 define this, if you don't use i2c muxes on your hardware.
2138 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2141 CONFIG_SYS_I2C_MAX_HOPS
2142 define how many muxes are maximal consecutively connected
2143 on one i2c bus. If you not use i2c muxes, omit this
2146 CONFIG_SYS_I2C_BUSES
2147 hold a list of busses you want to use, only used if
2148 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2149 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2150 CONFIG_SYS_NUM_I2C_BUSES = 9:
2152 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2153 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2154 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2155 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2156 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2157 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2158 {1, {I2C_NULL_HOP}}, \
2159 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2160 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2164 bus 0 on adapter 0 without a mux
2165 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2166 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2167 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2168 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2169 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2170 bus 6 on adapter 1 without a mux
2171 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2172 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2174 If you do not have i2c muxes on your board, omit this define.
2176 - Legacy I2C Support: CONFIG_HARD_I2C
2178 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2179 provides the following compelling advantages:
2181 - more than one i2c adapter is usable
2182 - approved multibus support
2183 - better i2c mux support
2185 ** Please consider updating your I2C driver now. **
2187 These enable legacy I2C serial bus commands. Defining
2188 CONFIG_HARD_I2C will include the appropriate I2C driver
2189 for the selected CPU.
2191 This will allow you to use i2c commands at the u-boot
2192 command line (as long as you set CONFIG_CMD_I2C in
2193 CONFIG_COMMANDS) and communicate with i2c based realtime
2194 clock chips. See common/cmd_i2c.c for a description of the
2195 command line interface.
2197 CONFIG_HARD_I2C selects a hardware I2C controller.
2199 There are several other quantities that must also be
2200 defined when you define CONFIG_HARD_I2C.
2202 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2203 to be the frequency (in Hz) at which you wish your i2c bus
2204 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2205 the CPU's i2c node address).
2207 Now, the u-boot i2c code for the mpc8xx
2208 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2209 and so its address should therefore be cleared to 0 (See,
2210 eg, MPC823e User's Manual p.16-473). So, set
2211 CONFIG_SYS_I2C_SLAVE to 0.
2213 CONFIG_SYS_I2C_INIT_MPC5XXX
2215 When a board is reset during an i2c bus transfer
2216 chips might think that the current transfer is still
2217 in progress. Reset the slave devices by sending start
2218 commands until the slave device responds.
2220 That's all that's required for CONFIG_HARD_I2C.
2222 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2223 then the following macros need to be defined (examples are
2224 from include/configs/lwmon.h):
2228 (Optional). Any commands necessary to enable the I2C
2229 controller or configure ports.
2231 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2235 (Only for MPC8260 CPU). The I/O port to use (the code
2236 assumes both bits are on the same port). Valid values
2237 are 0..3 for ports A..D.
2241 The code necessary to make the I2C data line active
2242 (driven). If the data line is open collector, this
2245 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2249 The code necessary to make the I2C data line tri-stated
2250 (inactive). If the data line is open collector, this
2253 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2257 Code that returns true if the I2C data line is high,
2260 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2264 If <bit> is true, sets the I2C data line high. If it
2265 is false, it clears it (low).
2267 eg: #define I2C_SDA(bit) \
2268 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2269 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2273 If <bit> is true, sets the I2C clock line high. If it
2274 is false, it clears it (low).
2276 eg: #define I2C_SCL(bit) \
2277 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2278 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2282 This delay is invoked four times per clock cycle so this
2283 controls the rate of data transfer. The data rate thus
2284 is 1 / (I2C_DELAY * 4). Often defined to be something
2287 #define I2C_DELAY udelay(2)
2289 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2291 If your arch supports the generic GPIO framework (asm/gpio.h),
2292 then you may alternatively define the two GPIOs that are to be
2293 used as SCL / SDA. Any of the previous I2C_xxx macros will
2294 have GPIO-based defaults assigned to them as appropriate.
2296 You should define these to the GPIO value as given directly to
2297 the generic GPIO functions.
2299 CONFIG_SYS_I2C_INIT_BOARD
2301 When a board is reset during an i2c bus transfer
2302 chips might think that the current transfer is still
2303 in progress. On some boards it is possible to access
2304 the i2c SCLK line directly, either by using the
2305 processor pin as a GPIO or by having a second pin
2306 connected to the bus. If this option is defined a
2307 custom i2c_init_board() routine in boards/xxx/board.c
2308 is run early in the boot sequence.
2310 CONFIG_SYS_I2C_BOARD_LATE_INIT
2312 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2313 defined a custom i2c_board_late_init() routine in
2314 boards/xxx/board.c is run AFTER the operations in i2c_init()
2315 is completed. This callpoint can be used to unreset i2c bus
2316 using CPU i2c controller register accesses for CPUs whose i2c
2317 controller provide such a method. It is called at the end of
2318 i2c_init() to allow i2c_init operations to setup the i2c bus
2319 controller on the CPU (e.g. setting bus speed & slave address).
2321 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2323 This option enables configuration of bi_iic_fast[] flags
2324 in u-boot bd_info structure based on u-boot environment
2325 variable "i2cfast". (see also i2cfast)
2327 CONFIG_I2C_MULTI_BUS
2329 This option allows the use of multiple I2C buses, each of which
2330 must have a controller. At any point in time, only one bus is
2331 active. To switch to a different bus, use the 'i2c dev' command.
2332 Note that bus numbering is zero-based.
2334 CONFIG_SYS_I2C_NOPROBES
2336 This option specifies a list of I2C devices that will be skipped
2337 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2338 is set, specify a list of bus-device pairs. Otherwise, specify
2339 a 1D array of device addresses
2342 #undef CONFIG_I2C_MULTI_BUS
2343 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2345 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2347 #define CONFIG_I2C_MULTI_BUS
2348 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2350 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2352 CONFIG_SYS_SPD_BUS_NUM
2354 If defined, then this indicates the I2C bus number for DDR SPD.
2355 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2357 CONFIG_SYS_RTC_BUS_NUM
2359 If defined, then this indicates the I2C bus number for the RTC.
2360 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2362 CONFIG_SYS_DTT_BUS_NUM
2364 If defined, then this indicates the I2C bus number for the DTT.
2365 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2367 CONFIG_SYS_I2C_DTT_ADDR:
2369 If defined, specifies the I2C address of the DTT device.
2370 If not defined, then U-Boot uses predefined value for
2371 specified DTT device.
2373 CONFIG_SOFT_I2C_READ_REPEATED_START
2375 defining this will force the i2c_read() function in
2376 the soft_i2c driver to perform an I2C repeated start
2377 between writing the address pointer and reading the
2378 data. If this define is omitted the default behaviour
2379 of doing a stop-start sequence will be used. Most I2C
2380 devices can use either method, but some require one or
2383 - SPI Support: CONFIG_SPI
2385 Enables SPI driver (so far only tested with
2386 SPI EEPROM, also an instance works with Crystal A/D and
2387 D/As on the SACSng board)
2391 Enables the driver for SPI controller on SuperH. Currently
2392 only SH7757 is supported.
2396 Enables extended (16-bit) SPI EEPROM addressing.
2397 (symmetrical to CONFIG_I2C_X)
2401 Enables a software (bit-bang) SPI driver rather than
2402 using hardware support. This is a general purpose
2403 driver that only requires three general I/O port pins
2404 (two outputs, one input) to function. If this is
2405 defined, the board configuration must define several
2406 SPI configuration items (port pins to use, etc). For
2407 an example, see include/configs/sacsng.h.
2411 Enables a hardware SPI driver for general-purpose reads
2412 and writes. As with CONFIG_SOFT_SPI, the board configuration
2413 must define a list of chip-select function pointers.
2414 Currently supported on some MPC8xxx processors. For an
2415 example, see include/configs/mpc8349emds.h.
2419 Enables the driver for the SPI controllers on i.MX and MXC
2420 SoCs. Currently i.MX31/35/51 are supported.
2422 - FPGA Support: CONFIG_FPGA
2424 Enables FPGA subsystem.
2426 CONFIG_FPGA_<vendor>
2428 Enables support for specific chip vendors.
2431 CONFIG_FPGA_<family>
2433 Enables support for FPGA family.
2434 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2438 Specify the number of FPGA devices to support.
2440 CONFIG_SYS_FPGA_PROG_FEEDBACK
2442 Enable printing of hash marks during FPGA configuration.
2444 CONFIG_SYS_FPGA_CHECK_BUSY
2446 Enable checks on FPGA configuration interface busy
2447 status by the configuration function. This option
2448 will require a board or device specific function to
2453 If defined, a function that provides delays in the FPGA
2454 configuration driver.
2456 CONFIG_SYS_FPGA_CHECK_CTRLC
2457 Allow Control-C to interrupt FPGA configuration
2459 CONFIG_SYS_FPGA_CHECK_ERROR
2461 Check for configuration errors during FPGA bitfile
2462 loading. For example, abort during Virtex II
2463 configuration if the INIT_B line goes low (which
2464 indicated a CRC error).
2466 CONFIG_SYS_FPGA_WAIT_INIT
2468 Maximum time to wait for the INIT_B line to deassert
2469 after PROB_B has been deasserted during a Virtex II
2470 FPGA configuration sequence. The default time is 500
2473 CONFIG_SYS_FPGA_WAIT_BUSY
2475 Maximum time to wait for BUSY to deassert during
2476 Virtex II FPGA configuration. The default is 5 ms.
2478 CONFIG_SYS_FPGA_WAIT_CONFIG
2480 Time to wait after FPGA configuration. The default is
2483 - Configuration Management:
2486 If defined, this string will be added to the U-Boot
2487 version information (U_BOOT_VERSION)
2489 - Vendor Parameter Protection:
2491 U-Boot considers the values of the environment
2492 variables "serial#" (Board Serial Number) and
2493 "ethaddr" (Ethernet Address) to be parameters that
2494 are set once by the board vendor / manufacturer, and
2495 protects these variables from casual modification by
2496 the user. Once set, these variables are read-only,
2497 and write or delete attempts are rejected. You can
2498 change this behaviour:
2500 If CONFIG_ENV_OVERWRITE is #defined in your config
2501 file, the write protection for vendor parameters is
2502 completely disabled. Anybody can change or delete
2505 Alternatively, if you #define _both_ CONFIG_ETHADDR
2506 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2507 Ethernet address is installed in the environment,
2508 which can be changed exactly ONCE by the user. [The
2509 serial# is unaffected by this, i. e. it remains
2512 The same can be accomplished in a more flexible way
2513 for any variable by configuring the type of access
2514 to allow for those variables in the ".flags" variable
2515 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2520 Define this variable to enable the reservation of
2521 "protected RAM", i. e. RAM which is not overwritten
2522 by U-Boot. Define CONFIG_PRAM to hold the number of
2523 kB you want to reserve for pRAM. You can overwrite
2524 this default value by defining an environment
2525 variable "pram" to the number of kB you want to
2526 reserve. Note that the board info structure will
2527 still show the full amount of RAM. If pRAM is
2528 reserved, a new environment variable "mem" will
2529 automatically be defined to hold the amount of
2530 remaining RAM in a form that can be passed as boot
2531 argument to Linux, for instance like that:
2533 setenv bootargs ... mem=\${mem}
2536 This way you can tell Linux not to use this memory,
2537 either, which results in a memory region that will
2538 not be affected by reboots.
2540 *WARNING* If your board configuration uses automatic
2541 detection of the RAM size, you must make sure that
2542 this memory test is non-destructive. So far, the
2543 following board configurations are known to be
2546 IVMS8, IVML24, SPD8xx, TQM8xxL,
2547 HERMES, IP860, RPXlite, LWMON,
2550 - Access to physical memory region (> 4GB)
2551 Some basic support is provided for operations on memory not
2552 normally accessible to U-Boot - e.g. some architectures
2553 support access to more than 4GB of memory on 32-bit
2554 machines using physical address extension or similar.
2555 Define CONFIG_PHYSMEM to access this basic support, which
2556 currently only supports clearing the memory.
2561 Define this variable to stop the system in case of a
2562 fatal error, so that you have to reset it manually.
2563 This is probably NOT a good idea for an embedded
2564 system where you want the system to reboot
2565 automatically as fast as possible, but it may be
2566 useful during development since you can try to debug
2567 the conditions that lead to the situation.
2569 CONFIG_NET_RETRY_COUNT
2571 This variable defines the number of retries for
2572 network operations like ARP, RARP, TFTP, or BOOTP
2573 before giving up the operation. If not defined, a
2574 default value of 5 is used.
2578 Timeout waiting for an ARP reply in milliseconds.
2582 Timeout in milliseconds used in NFS protocol.
2583 If you encounter "ERROR: Cannot umount" in nfs command,
2584 try longer timeout such as
2585 #define CONFIG_NFS_TIMEOUT 10000UL
2587 - Command Interpreter:
2588 CONFIG_AUTO_COMPLETE
2590 Enable auto completion of commands using TAB.
2592 Note that this feature has NOT been implemented yet
2593 for the "hush" shell.
2596 CONFIG_SYS_HUSH_PARSER
2598 Define this variable to enable the "hush" shell (from
2599 Busybox) as command line interpreter, thus enabling
2600 powerful command line syntax like
2601 if...then...else...fi conditionals or `&&' and '||'
2602 constructs ("shell scripts").
2604 If undefined, you get the old, much simpler behaviour
2605 with a somewhat smaller memory footprint.
2608 CONFIG_SYS_PROMPT_HUSH_PS2
2610 This defines the secondary prompt string, which is
2611 printed when the command interpreter needs more input
2612 to complete a command. Usually "> ".
2616 In the current implementation, the local variables
2617 space and global environment variables space are
2618 separated. Local variables are those you define by
2619 simply typing `name=value'. To access a local
2620 variable later on, you have write `$name' or
2621 `${name}'; to execute the contents of a variable
2622 directly type `$name' at the command prompt.
2624 Global environment variables are those you use
2625 setenv/printenv to work with. To run a command stored
2626 in such a variable, you need to use the run command,
2627 and you must not use the '$' sign to access them.
2629 To store commands and special characters in a
2630 variable, please use double quotation marks
2631 surrounding the whole text of the variable, instead
2632 of the backslashes before semicolons and special
2635 - Commandline Editing and History:
2636 CONFIG_CMDLINE_EDITING
2638 Enable editing and History functions for interactive
2639 commandline input operations
2641 - Default Environment:
2642 CONFIG_EXTRA_ENV_SETTINGS
2644 Define this to contain any number of null terminated
2645 strings (variable = value pairs) that will be part of
2646 the default environment compiled into the boot image.
2648 For example, place something like this in your
2649 board's config file:
2651 #define CONFIG_EXTRA_ENV_SETTINGS \
2655 Warning: This method is based on knowledge about the
2656 internal format how the environment is stored by the
2657 U-Boot code. This is NOT an official, exported
2658 interface! Although it is unlikely that this format
2659 will change soon, there is no guarantee either.
2660 You better know what you are doing here.
2662 Note: overly (ab)use of the default environment is
2663 discouraged. Make sure to check other ways to preset
2664 the environment like the "source" command or the
2667 CONFIG_ENV_VARS_UBOOT_CONFIG
2669 Define this in order to add variables describing the
2670 U-Boot build configuration to the default environment.
2671 These will be named arch, cpu, board, vendor, and soc.
2673 Enabling this option will cause the following to be defined:
2681 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2683 Define this in order to add variables describing certain
2684 run-time determined information about the hardware to the
2685 environment. These will be named board_name, board_rev.
2687 CONFIG_DELAY_ENVIRONMENT
2689 Normally the environment is loaded when the board is
2690 intialised so that it is available to U-Boot. This inhibits
2691 that so that the environment is not available until
2692 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2693 this is instead controlled by the value of
2694 /config/load-environment.
2696 - DataFlash Support:
2697 CONFIG_HAS_DATAFLASH
2699 Defining this option enables DataFlash features and
2700 allows to read/write in Dataflash via the standard
2703 - Serial Flash support
2706 Defining this option enables SPI flash commands
2707 'sf probe/read/write/erase/update'.
2709 Usage requires an initial 'probe' to define the serial
2710 flash parameters, followed by read/write/erase/update
2713 The following defaults may be provided by the platform
2714 to handle the common case when only a single serial
2715 flash is present on the system.
2717 CONFIG_SF_DEFAULT_BUS Bus identifier
2718 CONFIG_SF_DEFAULT_CS Chip-select
2719 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2720 CONFIG_SF_DEFAULT_SPEED in Hz
2724 Define this option to include a destructive SPI flash
2727 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2729 Define this option to use the Bank addr/Extended addr
2730 support on SPI flashes which has size > 16Mbytes.
2732 - SystemACE Support:
2735 Adding this option adds support for Xilinx SystemACE
2736 chips attached via some sort of local bus. The address
2737 of the chip must also be defined in the
2738 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2740 #define CONFIG_SYSTEMACE
2741 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2743 When SystemACE support is added, the "ace" device type
2744 becomes available to the fat commands, i.e. fatls.
2746 - TFTP Fixed UDP Port:
2749 If this is defined, the environment variable tftpsrcp
2750 is used to supply the TFTP UDP source port value.
2751 If tftpsrcp isn't defined, the normal pseudo-random port
2752 number generator is used.
2754 Also, the environment variable tftpdstp is used to supply
2755 the TFTP UDP destination port value. If tftpdstp isn't
2756 defined, the normal port 69 is used.
2758 The purpose for tftpsrcp is to allow a TFTP server to
2759 blindly start the TFTP transfer using the pre-configured
2760 target IP address and UDP port. This has the effect of
2761 "punching through" the (Windows XP) firewall, allowing
2762 the remainder of the TFTP transfer to proceed normally.
2763 A better solution is to properly configure the firewall,
2764 but sometimes that is not allowed.
2769 This enables a generic 'hash' command which can produce
2770 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2774 Enable the hash verify command (hash -v). This adds to code
2777 CONFIG_SHA1 - support SHA1 hashing
2778 CONFIG_SHA256 - support SHA256 hashing
2780 Note: There is also a sha1sum command, which should perhaps
2781 be deprecated in favour of 'hash sha1'.
2783 - Freescale i.MX specific commands:
2784 CONFIG_CMD_HDMIDETECT
2785 This enables 'hdmidet' command which returns true if an
2786 HDMI monitor is detected. This command is i.MX 6 specific.
2789 This enables the 'bmode' (bootmode) command for forcing
2790 a boot from specific media.
2792 This is useful for forcing the ROM's usb downloader to
2793 activate upon a watchdog reset which is nice when iterating
2794 on U-Boot. Using the reset button or running bmode normal
2795 will set it back to normal. This command currently
2796 supports i.MX53 and i.MX6.
2801 This enables the RSA algorithm used for FIT image verification
2802 in U-Boot. See doc/uImage/signature for more information.
2804 The signing part is build into mkimage regardless of this
2808 - Show boot progress:
2809 CONFIG_SHOW_BOOT_PROGRESS
2811 Defining this option allows to add some board-
2812 specific code (calling a user-provided function
2813 "show_boot_progress(int)") that enables you to show
2814 the system's boot progress on some display (for
2815 example, some LED's) on your board. At the moment,
2816 the following checkpoints are implemented:
2818 - Detailed boot stage timing
2820 Define this option to get detailed timing of each stage
2821 of the boot process.
2823 CONFIG_BOOTSTAGE_USER_COUNT
2824 This is the number of available user bootstage records.
2825 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2826 a new ID will be allocated from this stash. If you exceed
2827 the limit, recording will stop.
2829 CONFIG_BOOTSTAGE_REPORT
2830 Define this to print a report before boot, similar to this:
2832 Timer summary in microseconds:
2835 3,575,678 3,575,678 board_init_f start
2836 3,575,695 17 arch_cpu_init A9
2837 3,575,777 82 arch_cpu_init done
2838 3,659,598 83,821 board_init_r start
2839 3,910,375 250,777 main_loop
2840 29,916,167 26,005,792 bootm_start
2841 30,361,327 445,160 start_kernel
2843 CONFIG_CMD_BOOTSTAGE
2844 Add a 'bootstage' command which supports printing a report
2845 and un/stashing of bootstage data.
2847 CONFIG_BOOTSTAGE_FDT
2848 Stash the bootstage information in the FDT. A root 'bootstage'
2849 node is created with each bootstage id as a child. Each child
2850 has a 'name' property and either 'mark' containing the
2851 mark time in microsecond, or 'accum' containing the
2852 accumulated time for that bootstage id in microseconds.
2857 name = "board_init_f";
2866 Code in the Linux kernel can find this in /proc/devicetree.
2868 Legacy uImage format:
2871 1 common/cmd_bootm.c before attempting to boot an image
2872 -1 common/cmd_bootm.c Image header has bad magic number
2873 2 common/cmd_bootm.c Image header has correct magic number
2874 -2 common/cmd_bootm.c Image header has bad checksum
2875 3 common/cmd_bootm.c Image header has correct checksum
2876 -3 common/cmd_bootm.c Image data has bad checksum
2877 4 common/cmd_bootm.c Image data has correct checksum
2878 -4 common/cmd_bootm.c Image is for unsupported architecture
2879 5 common/cmd_bootm.c Architecture check OK
2880 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2881 6 common/cmd_bootm.c Image Type check OK
2882 -6 common/cmd_bootm.c gunzip uncompression error
2883 -7 common/cmd_bootm.c Unimplemented compression type
2884 7 common/cmd_bootm.c Uncompression OK
2885 8 common/cmd_bootm.c No uncompress/copy overwrite error
2886 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2888 9 common/image.c Start initial ramdisk verification
2889 -10 common/image.c Ramdisk header has bad magic number
2890 -11 common/image.c Ramdisk header has bad checksum
2891 10 common/image.c Ramdisk header is OK
2892 -12 common/image.c Ramdisk data has bad checksum
2893 11 common/image.c Ramdisk data has correct checksum
2894 12 common/image.c Ramdisk verification complete, start loading
2895 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2896 13 common/image.c Start multifile image verification
2897 14 common/image.c No initial ramdisk, no multifile, continue.
2899 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2901 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2902 -31 post/post.c POST test failed, detected by post_output_backlog()
2903 -32 post/post.c POST test failed, detected by post_run_single()
2905 34 common/cmd_doc.c before loading a Image from a DOC device
2906 -35 common/cmd_doc.c Bad usage of "doc" command
2907 35 common/cmd_doc.c correct usage of "doc" command
2908 -36 common/cmd_doc.c No boot device
2909 36 common/cmd_doc.c correct boot device
2910 -37 common/cmd_doc.c Unknown Chip ID on boot device
2911 37 common/cmd_doc.c correct chip ID found, device available
2912 -38 common/cmd_doc.c Read Error on boot device
2913 38 common/cmd_doc.c reading Image header from DOC device OK
2914 -39 common/cmd_doc.c Image header has bad magic number
2915 39 common/cmd_doc.c Image header has correct magic number
2916 -40 common/cmd_doc.c Error reading Image from DOC device
2917 40 common/cmd_doc.c Image header has correct magic number
2918 41 common/cmd_ide.c before loading a Image from a IDE device
2919 -42 common/cmd_ide.c Bad usage of "ide" command
2920 42 common/cmd_ide.c correct usage of "ide" command
2921 -43 common/cmd_ide.c No boot device
2922 43 common/cmd_ide.c boot device found
2923 -44 common/cmd_ide.c Device not available
2924 44 common/cmd_ide.c Device available
2925 -45 common/cmd_ide.c wrong partition selected
2926 45 common/cmd_ide.c partition selected
2927 -46 common/cmd_ide.c Unknown partition table
2928 46 common/cmd_ide.c valid partition table found
2929 -47 common/cmd_ide.c Invalid partition type
2930 47 common/cmd_ide.c correct partition type
2931 -48 common/cmd_ide.c Error reading Image Header on boot device
2932 48 common/cmd_ide.c reading Image Header from IDE device OK
2933 -49 common/cmd_ide.c Image header has bad magic number
2934 49 common/cmd_ide.c Image header has correct magic number
2935 -50 common/cmd_ide.c Image header has bad checksum
2936 50 common/cmd_ide.c Image header has correct checksum
2937 -51 common/cmd_ide.c Error reading Image from IDE device
2938 51 common/cmd_ide.c reading Image from IDE device OK
2939 52 common/cmd_nand.c before loading a Image from a NAND device
2940 -53 common/cmd_nand.c Bad usage of "nand" command
2941 53 common/cmd_nand.c correct usage of "nand" command
2942 -54 common/cmd_nand.c No boot device
2943 54 common/cmd_nand.c boot device found
2944 -55 common/cmd_nand.c Unknown Chip ID on boot device
2945 55 common/cmd_nand.c correct chip ID found, device available
2946 -56 common/cmd_nand.c Error reading Image Header on boot device
2947 56 common/cmd_nand.c reading Image Header from NAND device OK
2948 -57 common/cmd_nand.c Image header has bad magic number
2949 57 common/cmd_nand.c Image header has correct magic number
2950 -58 common/cmd_nand.c Error reading Image from NAND device
2951 58 common/cmd_nand.c reading Image from NAND device OK
2953 -60 common/env_common.c Environment has a bad CRC, using default
2955 64 net/eth.c starting with Ethernet configuration.
2956 -64 net/eth.c no Ethernet found.
2957 65 net/eth.c Ethernet found.
2959 -80 common/cmd_net.c usage wrong
2960 80 common/cmd_net.c before calling NetLoop()
2961 -81 common/cmd_net.c some error in NetLoop() occurred
2962 81 common/cmd_net.c NetLoop() back without error
2963 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2964 82 common/cmd_net.c trying automatic boot
2965 83 common/cmd_net.c running "source" command
2966 -83 common/cmd_net.c some error in automatic boot or "source" command
2967 84 common/cmd_net.c end without errors
2972 100 common/cmd_bootm.c Kernel FIT Image has correct format
2973 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2974 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2975 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2976 102 common/cmd_bootm.c Kernel unit name specified
2977 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2978 103 common/cmd_bootm.c Found configuration node
2979 104 common/cmd_bootm.c Got kernel subimage node offset
2980 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2981 105 common/cmd_bootm.c Kernel subimage hash verification OK
2982 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2983 106 common/cmd_bootm.c Architecture check OK
2984 -106 common/cmd_bootm.c Kernel subimage has wrong type
2985 107 common/cmd_bootm.c Kernel subimage type OK
2986 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2987 108 common/cmd_bootm.c Got kernel subimage data/size
2988 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2989 -109 common/cmd_bootm.c Can't get kernel subimage type
2990 -110 common/cmd_bootm.c Can't get kernel subimage comp
2991 -111 common/cmd_bootm.c Can't get kernel subimage os
2992 -112 common/cmd_bootm.c Can't get kernel subimage load address
2993 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2995 120 common/image.c Start initial ramdisk verification
2996 -120 common/image.c Ramdisk FIT image has incorrect format
2997 121 common/image.c Ramdisk FIT image has correct format
2998 122 common/image.c No ramdisk subimage unit name, using configuration
2999 -122 common/image.c Can't get configuration for ramdisk subimage
3000 123 common/image.c Ramdisk unit name specified
3001 -124 common/image.c Can't get ramdisk subimage node offset
3002 125 common/image.c Got ramdisk subimage node offset
3003 -125 common/image.c Ramdisk subimage hash verification failed
3004 126 common/image.c Ramdisk subimage hash verification OK
3005 -126 common/image.c Ramdisk subimage for unsupported architecture
3006 127 common/image.c Architecture check OK
3007 -127 common/image.c Can't get ramdisk subimage data/size
3008 128 common/image.c Got ramdisk subimage data/size
3009 129 common/image.c Can't get ramdisk load address
3010 -129 common/image.c Got ramdisk load address
3012 -130 common/cmd_doc.c Incorrect FIT image format
3013 131 common/cmd_doc.c FIT image format OK
3015 -140 common/cmd_ide.c Incorrect FIT image format
3016 141 common/cmd_ide.c FIT image format OK
3018 -150 common/cmd_nand.c Incorrect FIT image format
3019 151 common/cmd_nand.c FIT image format OK
3021 - FIT image support:
3023 Enable support for the FIT uImage format.
3025 CONFIG_FIT_BEST_MATCH
3026 When no configuration is explicitly selected, default to the
3027 one whose fdt's compatibility field best matches that of
3028 U-Boot itself. A match is considered "best" if it matches the
3029 most specific compatibility entry of U-Boot's fdt's root node.
3030 The order of entries in the configuration's fdt is ignored.
3032 CONFIG_FIT_SIGNATURE
3033 This option enables signature verification of FIT uImages,
3034 using a hash signed and verified using RSA. See
3035 doc/uImage.FIT/signature.txt for more details.
3037 - Standalone program support:
3038 CONFIG_STANDALONE_LOAD_ADDR
3040 This option defines a board specific value for the
3041 address where standalone program gets loaded, thus
3042 overwriting the architecture dependent default
3045 - Frame Buffer Address:
3048 Define CONFIG_FB_ADDR if you want to use specific
3049 address for frame buffer. This is typically the case
3050 when using a graphics controller has separate video
3051 memory. U-Boot will then place the frame buffer at
3052 the given address instead of dynamically reserving it
3053 in system RAM by calling lcd_setmem(), which grabs
3054 the memory for the frame buffer depending on the
3055 configured panel size.
3057 Please see board_init_f function.
3059 - Automatic software updates via TFTP server
3061 CONFIG_UPDATE_TFTP_CNT_MAX
3062 CONFIG_UPDATE_TFTP_MSEC_MAX
3064 These options enable and control the auto-update feature;
3065 for a more detailed description refer to doc/README.update.
3067 - MTD Support (mtdparts command, UBI support)
3070 Adds the MTD device infrastructure from the Linux kernel.
3071 Needed for mtdparts command support.
3073 CONFIG_MTD_PARTITIONS
3075 Adds the MTD partitioning infrastructure from the Linux
3076 kernel. Needed for UBI support.
3081 Adds commands for interacting with MTD partitions formatted
3082 with the UBI flash translation layer
3084 Requires also defining CONFIG_RBTREE
3086 CONFIG_UBI_SILENCE_MSG
3088 Make the verbose messages from UBI stop printing. This leaves
3089 warnings and errors enabled.
3094 Adds commands for interacting with UBI volumes formatted as
3095 UBIFS. UBIFS is read-only in u-boot.
3097 Requires UBI support as well as CONFIG_LZO
3099 CONFIG_UBIFS_SILENCE_MSG
3101 Make the verbose messages from UBIFS stop printing. This leaves
3102 warnings and errors enabled.
3106 Enable building of SPL globally.
3109 LDSCRIPT for linking the SPL binary.
3111 CONFIG_SPL_MAX_FOOTPRINT
3112 Maximum size in memory allocated to the SPL, BSS included.
3113 When defined, the linker checks that the actual memory
3114 used by SPL from _start to __bss_end does not exceed it.
3115 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3116 must not be both defined at the same time.
3119 Maximum size of the SPL image (text, data, rodata, and
3120 linker lists sections), BSS excluded.
3121 When defined, the linker checks that the actual size does
3124 CONFIG_SPL_TEXT_BASE
3125 TEXT_BASE for linking the SPL binary.
3127 CONFIG_SPL_RELOC_TEXT_BASE
3128 Address to relocate to. If unspecified, this is equal to
3129 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3131 CONFIG_SPL_BSS_START_ADDR
3132 Link address for the BSS within the SPL binary.
3134 CONFIG_SPL_BSS_MAX_SIZE
3135 Maximum size in memory allocated to the SPL BSS.
3136 When defined, the linker checks that the actual memory used
3137 by SPL from __bss_start to __bss_end does not exceed it.
3138 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3139 must not be both defined at the same time.
3142 Adress of the start of the stack SPL will use
3144 CONFIG_SPL_RELOC_STACK
3145 Adress of the start of the stack SPL will use after
3146 relocation. If unspecified, this is equal to
3149 CONFIG_SYS_SPL_MALLOC_START
3150 Starting address of the malloc pool used in SPL.
3152 CONFIG_SYS_SPL_MALLOC_SIZE
3153 The size of the malloc pool used in SPL.
3155 CONFIG_SPL_FRAMEWORK
3156 Enable the SPL framework under common/. This framework
3157 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3158 NAND loading of the Linux Kernel.
3160 CONFIG_SPL_DISPLAY_PRINT
3161 For ARM, enable an optional function to print more information
3162 about the running system.
3164 CONFIG_SPL_INIT_MINIMAL
3165 Arch init code should be built for a very small image
3167 CONFIG_SPL_LIBCOMMON_SUPPORT
3168 Support for common/libcommon.o in SPL binary
3170 CONFIG_SPL_LIBDISK_SUPPORT
3171 Support for disk/libdisk.o in SPL binary
3173 CONFIG_SPL_I2C_SUPPORT
3174 Support for drivers/i2c/libi2c.o in SPL binary
3176 CONFIG_SPL_GPIO_SUPPORT
3177 Support for drivers/gpio/libgpio.o in SPL binary
3179 CONFIG_SPL_MMC_SUPPORT
3180 Support for drivers/mmc/libmmc.o in SPL binary
3182 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3183 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3184 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3185 Address, size and partition on the MMC to load U-Boot from
3186 when the MMC is being used in raw mode.
3188 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3189 Sector to load kernel uImage from when MMC is being
3190 used in raw mode (for Falcon mode)
3192 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3193 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3194 Sector and number of sectors to load kernel argument
3195 parameters from when MMC is being used in raw mode
3198 CONFIG_SPL_FAT_SUPPORT
3199 Support for fs/fat/libfat.o in SPL binary
3201 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3202 Filename to read to load U-Boot when reading from FAT
3204 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3205 Filename to read to load kernel uImage when reading
3206 from FAT (for Falcon mode)
3208 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3209 Filename to read to load kernel argument parameters
3210 when reading from FAT (for Falcon mode)
3212 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3213 Set this for NAND SPL on PPC mpc83xx targets, so that
3214 start.S waits for the rest of the SPL to load before
3215 continuing (the hardware starts execution after just
3216 loading the first page rather than the full 4K).
3218 CONFIG_SPL_NAND_BASE
3219 Include nand_base.c in the SPL. Requires
3220 CONFIG_SPL_NAND_DRIVERS.
3222 CONFIG_SPL_NAND_DRIVERS
3223 SPL uses normal NAND drivers, not minimal drivers.
3226 Include standard software ECC in the SPL
3228 CONFIG_SPL_NAND_SIMPLE
3229 Support for NAND boot using simple NAND drivers that
3230 expose the cmd_ctrl() interface.
3232 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3233 Set for the SPL on PPC mpc8xxx targets, support for
3234 drivers/ddr/fsl/libddr.o in SPL binary.
3236 CONFIG_SPL_COMMON_INIT_DDR
3237 Set for common ddr init with serial presence detect in
3240 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3241 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3242 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3243 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3244 CONFIG_SYS_NAND_ECCBYTES
3245 Defines the size and behavior of the NAND that SPL uses
3248 CONFIG_SYS_NAND_U_BOOT_OFFS
3249 Location in NAND to read U-Boot from
3251 CONFIG_SYS_NAND_U_BOOT_DST
3252 Location in memory to load U-Boot to
3254 CONFIG_SYS_NAND_U_BOOT_SIZE
3255 Size of image to load
3257 CONFIG_SYS_NAND_U_BOOT_START
3258 Entry point in loaded image to jump to
3260 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3261 Define this if you need to first read the OOB and then the
3262 data. This is used for example on davinci plattforms.
3264 CONFIG_SPL_OMAP3_ID_NAND
3265 Support for an OMAP3-specific set of functions to return the
3266 ID and MFR of the first attached NAND chip, if present.
3268 CONFIG_SPL_SERIAL_SUPPORT
3269 Support for drivers/serial/libserial.o in SPL binary
3271 CONFIG_SPL_SPI_FLASH_SUPPORT
3272 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3274 CONFIG_SPL_SPI_SUPPORT
3275 Support for drivers/spi/libspi.o in SPL binary
3277 CONFIG_SPL_RAM_DEVICE
3278 Support for running image already present in ram, in SPL binary
3280 CONFIG_SPL_LIBGENERIC_SUPPORT
3281 Support for lib/libgeneric.o in SPL binary
3283 CONFIG_SPL_ENV_SUPPORT
3284 Support for the environment operating in SPL binary
3286 CONFIG_SPL_NET_SUPPORT
3287 Support for the net/libnet.o in SPL binary.
3288 It conflicts with SPL env from storage medium specified by
3289 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3292 Image offset to which the SPL should be padded before appending
3293 the SPL payload. By default, this is defined as
3294 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3295 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3296 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3299 Final target image containing SPL and payload. Some SPLs
3300 use an arch-specific makefile fragment instead, for
3301 example if more than one image needs to be produced.
3303 CONFIG_FIT_SPL_PRINT
3304 Printing information about a FIT image adds quite a bit of
3305 code to SPL. So this is normally disabled in SPL. Use this
3306 option to re-enable it. This will affect the output of the
3307 bootm command when booting a FIT image.
3311 Enable building of TPL globally.
3314 Image offset to which the TPL should be padded before appending
3315 the TPL payload. By default, this is defined as
3316 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3317 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3318 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3323 [so far only for SMDK2400 boards]
3325 - Modem support enable:
3326 CONFIG_MODEM_SUPPORT
3328 - RTS/CTS Flow control enable:
3331 - Modem debug support:
3332 CONFIG_MODEM_SUPPORT_DEBUG
3334 Enables debugging stuff (char screen[1024], dbg())
3335 for modem support. Useful only with BDI2000.
3337 - Interrupt support (PPC):
3339 There are common interrupt_init() and timer_interrupt()
3340 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3341 for CPU specific initialization. interrupt_init_cpu()
3342 should set decrementer_count to appropriate value. If
3343 CPU resets decrementer automatically after interrupt
3344 (ppc4xx) it should set decrementer_count to zero.
3345 timer_interrupt() calls timer_interrupt_cpu() for CPU
3346 specific handling. If board has watchdog / status_led
3347 / other_activity_monitor it works automatically from
3348 general timer_interrupt().
3352 In the target system modem support is enabled when a
3353 specific key (key combination) is pressed during
3354 power-on. Otherwise U-Boot will boot normally
3355 (autoboot). The key_pressed() function is called from
3356 board_init(). Currently key_pressed() is a dummy
3357 function, returning 1 and thus enabling modem
3360 If there are no modem init strings in the
3361 environment, U-Boot proceed to autoboot; the
3362 previous output (banner, info printfs) will be
3365 See also: doc/README.Modem
3367 Board initialization settings:
3368 ------------------------------
3370 During Initialization u-boot calls a number of board specific functions
3371 to allow the preparation of board specific prerequisites, e.g. pin setup
3372 before drivers are initialized. To enable these callbacks the
3373 following configuration macros have to be defined. Currently this is
3374 architecture specific, so please check arch/your_architecture/lib/board.c
3375 typically in board_init_f() and board_init_r().
3377 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3378 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3379 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3380 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3382 Configuration Settings:
3383 -----------------------
3385 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3386 undefine this when you're short of memory.
3388 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3389 width of the commands listed in the 'help' command output.
3391 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3392 prompt for user input.
3394 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3396 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3398 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3400 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3401 the application (usually a Linux kernel) when it is
3404 - CONFIG_SYS_BAUDRATE_TABLE:
3405 List of legal baudrate settings for this board.
3407 - CONFIG_SYS_CONSOLE_INFO_QUIET
3408 Suppress display of console information at boot.
3410 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3411 If the board specific function
3412 extern int overwrite_console (void);
3413 returns 1, the stdin, stderr and stdout are switched to the
3414 serial port, else the settings in the environment are used.
3416 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3417 Enable the call to overwrite_console().
3419 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3420 Enable overwrite of previous console environment settings.
3422 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3423 Begin and End addresses of the area used by the
3426 - CONFIG_SYS_ALT_MEMTEST:
3427 Enable an alternate, more extensive memory test.
3429 - CONFIG_SYS_MEMTEST_SCRATCH:
3430 Scratch address used by the alternate memory test
3431 You only need to set this if address zero isn't writeable
3433 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3434 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3435 this specified memory area will get subtracted from the top
3436 (end) of RAM and won't get "touched" at all by U-Boot. By
3437 fixing up gd->ram_size the Linux kernel should gets passed
3438 the now "corrected" memory size and won't touch it either.
3439 This should work for arch/ppc and arch/powerpc. Only Linux
3440 board ports in arch/powerpc with bootwrapper support that
3441 recalculate the memory size from the SDRAM controller setup
3442 will have to get fixed in Linux additionally.
3444 This option can be used as a workaround for the 440EPx/GRx
3445 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3448 WARNING: Please make sure that this value is a multiple of
3449 the Linux page size (normally 4k). If this is not the case,
3450 then the end address of the Linux memory will be located at a
3451 non page size aligned address and this could cause major
3454 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3455 Enable temporary baudrate change while serial download
3457 - CONFIG_SYS_SDRAM_BASE:
3458 Physical start address of SDRAM. _Must_ be 0 here.
3460 - CONFIG_SYS_MBIO_BASE:
3461 Physical start address of Motherboard I/O (if using a
3464 - CONFIG_SYS_FLASH_BASE:
3465 Physical start address of Flash memory.
3467 - CONFIG_SYS_MONITOR_BASE:
3468 Physical start address of boot monitor code (set by
3469 make config files to be same as the text base address
3470 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3471 CONFIG_SYS_FLASH_BASE when booting from flash.
3473 - CONFIG_SYS_MONITOR_LEN:
3474 Size of memory reserved for monitor code, used to
3475 determine _at_compile_time_ (!) if the environment is
3476 embedded within the U-Boot image, or in a separate
3479 - CONFIG_SYS_MALLOC_LEN:
3480 Size of DRAM reserved for malloc() use.
3482 - CONFIG_SYS_BOOTM_LEN:
3483 Normally compressed uImages are limited to an
3484 uncompressed size of 8 MBytes. If this is not enough,
3485 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3486 to adjust this setting to your needs.
3488 - CONFIG_SYS_BOOTMAPSZ:
3489 Maximum size of memory mapped by the startup code of
3490 the Linux kernel; all data that must be processed by
3491 the Linux kernel (bd_info, boot arguments, FDT blob if
3492 used) must be put below this limit, unless "bootm_low"
3493 environment variable is defined and non-zero. In such case
3494 all data for the Linux kernel must be between "bootm_low"
3495 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3496 variable "bootm_mapsize" will override the value of
3497 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3498 then the value in "bootm_size" will be used instead.
3500 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3501 Enable initrd_high functionality. If defined then the
3502 initrd_high feature is enabled and the bootm ramdisk subcommand
3505 - CONFIG_SYS_BOOT_GET_CMDLINE:
3506 Enables allocating and saving kernel cmdline in space between
3507 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3509 - CONFIG_SYS_BOOT_GET_KBD:
3510 Enables allocating and saving a kernel copy of the bd_info in
3511 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3513 - CONFIG_SYS_MAX_FLASH_BANKS:
3514 Max number of Flash memory banks
3516 - CONFIG_SYS_MAX_FLASH_SECT:
3517 Max number of sectors on a Flash chip
3519 - CONFIG_SYS_FLASH_ERASE_TOUT:
3520 Timeout for Flash erase operations (in ms)
3522 - CONFIG_SYS_FLASH_WRITE_TOUT:
3523 Timeout for Flash write operations (in ms)
3525 - CONFIG_SYS_FLASH_LOCK_TOUT
3526 Timeout for Flash set sector lock bit operation (in ms)
3528 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3529 Timeout for Flash clear lock bits operation (in ms)
3531 - CONFIG_SYS_FLASH_PROTECTION
3532 If defined, hardware flash sectors protection is used
3533 instead of U-Boot software protection.
3535 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3537 Enable TFTP transfers directly to flash memory;
3538 without this option such a download has to be
3539 performed in two steps: (1) download to RAM, and (2)
3540 copy from RAM to flash.
3542 The two-step approach is usually more reliable, since
3543 you can check if the download worked before you erase
3544 the flash, but in some situations (when system RAM is
3545 too limited to allow for a temporary copy of the
3546 downloaded image) this option may be very useful.
3548 - CONFIG_SYS_FLASH_CFI:
3549 Define if the flash driver uses extra elements in the
3550 common flash structure for storing flash geometry.
3552 - CONFIG_FLASH_CFI_DRIVER
3553 This option also enables the building of the cfi_flash driver
3554 in the drivers directory
3556 - CONFIG_FLASH_CFI_MTD
3557 This option enables the building of the cfi_mtd driver
3558 in the drivers directory. The driver exports CFI flash
3561 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3562 Use buffered writes to flash.
3564 - CONFIG_FLASH_SPANSION_S29WS_N
3565 s29ws-n MirrorBit flash has non-standard addresses for buffered
3568 - CONFIG_SYS_FLASH_QUIET_TEST
3569 If this option is defined, the common CFI flash doesn't
3570 print it's warning upon not recognized FLASH banks. This
3571 is useful, if some of the configured banks are only
3572 optionally available.
3574 - CONFIG_FLASH_SHOW_PROGRESS
3575 If defined (must be an integer), print out countdown
3576 digits and dots. Recommended value: 45 (9..1) for 80
3577 column displays, 15 (3..1) for 40 column displays.
3579 - CONFIG_FLASH_VERIFY
3580 If defined, the content of the flash (destination) is compared
3581 against the source after the write operation. An error message
3582 will be printed when the contents are not identical.
3583 Please note that this option is useless in nearly all cases,
3584 since such flash programming errors usually are detected earlier
3585 while unprotecting/erasing/programming. Please only enable
3586 this option if you really know what you are doing.
3588 - CONFIG_SYS_RX_ETH_BUFFER:
3589 Defines the number of Ethernet receive buffers. On some
3590 Ethernet controllers it is recommended to set this value
3591 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3592 buffers can be full shortly after enabling the interface
3593 on high Ethernet traffic.
3594 Defaults to 4 if not defined.
3596 - CONFIG_ENV_MAX_ENTRIES
3598 Maximum number of entries in the hash table that is used
3599 internally to store the environment settings. The default
3600 setting is supposed to be generous and should work in most
3601 cases. This setting can be used to tune behaviour; see
3602 lib/hashtable.c for details.
3604 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3605 - CONFIG_ENV_FLAGS_LIST_STATIC
3606 Enable validation of the values given to environment variables when
3607 calling env set. Variables can be restricted to only decimal,
3608 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3609 the variables can also be restricted to IP address or MAC address.
3611 The format of the list is:
3612 type_attribute = [s|d|x|b|i|m]
3613 access_atribute = [a|r|o|c]
3614 attributes = type_attribute[access_atribute]
3615 entry = variable_name[:attributes]
3618 The type attributes are:
3619 s - String (default)
3622 b - Boolean ([1yYtT|0nNfF])
3626 The access attributes are:
3632 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3633 Define this to a list (string) to define the ".flags"
3634 envirnoment variable in the default or embedded environment.
3636 - CONFIG_ENV_FLAGS_LIST_STATIC
3637 Define this to a list (string) to define validation that
3638 should be done if an entry is not found in the ".flags"
3639 environment variable. To override a setting in the static
3640 list, simply add an entry for the same variable name to the
3643 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3644 If defined, don't allow the -f switch to env set override variable
3647 - CONFIG_SYS_GENERIC_BOARD
3648 This selects the architecture-generic board system instead of the
3649 architecture-specific board files. It is intended to move boards
3650 to this new framework over time. Defining this will disable the
3651 arch/foo/lib/board.c file and use common/board_f.c and
3652 common/board_r.c instead. To use this option your architecture
3653 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3654 its config.mk file). If you find problems enabling this option on
3655 your board please report the problem and send patches!
3657 - CONFIG_SYS_SYM_OFFSETS
3658 This is set by architectures that use offsets for link symbols
3659 instead of absolute values. So bss_start is obtained using an
3660 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3661 directly. You should not need to touch this setting.
3663 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3664 This is set by OMAP boards for the max time that reset should
3665 be asserted. See doc/README.omap-reset-time for details on how
3666 the value can be calulated on a given board.
3668 The following definitions that deal with the placement and management
3669 of environment data (variable area); in general, we support the
3670 following configurations:
3672 - CONFIG_BUILD_ENVCRC:
3674 Builds up envcrc with the target environment so that external utils
3675 may easily extract it and embed it in final U-Boot images.
3677 - CONFIG_ENV_IS_IN_FLASH:
3679 Define this if the environment is in flash memory.
3681 a) The environment occupies one whole flash sector, which is
3682 "embedded" in the text segment with the U-Boot code. This
3683 happens usually with "bottom boot sector" or "top boot
3684 sector" type flash chips, which have several smaller
3685 sectors at the start or the end. For instance, such a
3686 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3687 such a case you would place the environment in one of the
3688 4 kB sectors - with U-Boot code before and after it. With
3689 "top boot sector" type flash chips, you would put the
3690 environment in one of the last sectors, leaving a gap
3691 between U-Boot and the environment.
3693 - CONFIG_ENV_OFFSET:
3695 Offset of environment data (variable area) to the
3696 beginning of flash memory; for instance, with bottom boot
3697 type flash chips the second sector can be used: the offset
3698 for this sector is given here.
3700 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3704 This is just another way to specify the start address of
3705 the flash sector containing the environment (instead of
3708 - CONFIG_ENV_SECT_SIZE:
3710 Size of the sector containing the environment.
3713 b) Sometimes flash chips have few, equal sized, BIG sectors.
3714 In such a case you don't want to spend a whole sector for
3719 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3720 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3721 of this flash sector for the environment. This saves
3722 memory for the RAM copy of the environment.
3724 It may also save flash memory if you decide to use this
3725 when your environment is "embedded" within U-Boot code,
3726 since then the remainder of the flash sector could be used
3727 for U-Boot code. It should be pointed out that this is
3728 STRONGLY DISCOURAGED from a robustness point of view:
3729 updating the environment in flash makes it always
3730 necessary to erase the WHOLE sector. If something goes
3731 wrong before the contents has been restored from a copy in
3732 RAM, your target system will be dead.
3734 - CONFIG_ENV_ADDR_REDUND
3735 CONFIG_ENV_SIZE_REDUND
3737 These settings describe a second storage area used to hold
3738 a redundant copy of the environment data, so that there is
3739 a valid backup copy in case there is a power failure during
3740 a "saveenv" operation.
3742 BE CAREFUL! Any changes to the flash layout, and some changes to the
3743 source code will make it necessary to adapt <board>/u-boot.lds*
3747 - CONFIG_ENV_IS_IN_NVRAM:
3749 Define this if you have some non-volatile memory device
3750 (NVRAM, battery buffered SRAM) which you want to use for the
3756 These two #defines are used to determine the memory area you
3757 want to use for environment. It is assumed that this memory
3758 can just be read and written to, without any special
3761 BE CAREFUL! The first access to the environment happens quite early
3762 in U-Boot initalization (when we try to get the setting of for the
3763 console baudrate). You *MUST* have mapped your NVRAM area then, or
3766 Please note that even with NVRAM we still use a copy of the
3767 environment in RAM: we could work on NVRAM directly, but we want to
3768 keep settings there always unmodified except somebody uses "saveenv"
3769 to save the current settings.
3772 - CONFIG_ENV_IS_IN_EEPROM:
3774 Use this if you have an EEPROM or similar serial access
3775 device and a driver for it.
3777 - CONFIG_ENV_OFFSET:
3780 These two #defines specify the offset and size of the
3781 environment area within the total memory of your EEPROM.
3783 - CONFIG_SYS_I2C_EEPROM_ADDR:
3784 If defined, specified the chip address of the EEPROM device.
3785 The default address is zero.
3787 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3788 If defined, the number of bits used to address bytes in a
3789 single page in the EEPROM device. A 64 byte page, for example
3790 would require six bits.
3792 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3793 If defined, the number of milliseconds to delay between
3794 page writes. The default is zero milliseconds.
3796 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3797 The length in bytes of the EEPROM memory array address. Note
3798 that this is NOT the chip address length!
3800 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3801 EEPROM chips that implement "address overflow" are ones
3802 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3803 address and the extra bits end up in the "chip address" bit
3804 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3807 Note that we consider the length of the address field to
3808 still be one byte because the extra address bits are hidden
3809 in the chip address.
3811 - CONFIG_SYS_EEPROM_SIZE:
3812 The size in bytes of the EEPROM device.
3814 - CONFIG_ENV_EEPROM_IS_ON_I2C
3815 define this, if you have I2C and SPI activated, and your
3816 EEPROM, which holds the environment, is on the I2C bus.
3818 - CONFIG_I2C_ENV_EEPROM_BUS
3819 if you have an Environment on an EEPROM reached over
3820 I2C muxes, you can define here, how to reach this
3821 EEPROM. For example:
3823 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3825 EEPROM which holds the environment, is reached over
3826 a pca9547 i2c mux with address 0x70, channel 3.
3828 - CONFIG_ENV_IS_IN_DATAFLASH:
3830 Define this if you have a DataFlash memory device which you
3831 want to use for the environment.
3833 - CONFIG_ENV_OFFSET:
3837 These three #defines specify the offset and size of the
3838 environment area within the total memory of your DataFlash placed
3839 at the specified address.
3841 - CONFIG_ENV_IS_IN_REMOTE:
3843 Define this if you have a remote memory space which you
3844 want to use for the local device's environment.
3849 These two #defines specify the address and size of the
3850 environment area within the remote memory space. The
3851 local device can get the environment from remote memory
3852 space by SRIO or PCIE links.
3854 BE CAREFUL! For some special cases, the local device can not use
3855 "saveenv" command. For example, the local device will get the
3856 environment stored in a remote NOR flash by SRIO or PCIE link,
3857 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3859 - CONFIG_ENV_IS_IN_NAND:
3861 Define this if you have a NAND device which you want to use
3862 for the environment.
3864 - CONFIG_ENV_OFFSET:
3867 These two #defines specify the offset and size of the environment
3868 area within the first NAND device. CONFIG_ENV_OFFSET must be
3869 aligned to an erase block boundary.
3871 - CONFIG_ENV_OFFSET_REDUND (optional):
3873 This setting describes a second storage area of CONFIG_ENV_SIZE
3874 size used to hold a redundant copy of the environment data, so
3875 that there is a valid backup copy in case there is a power failure
3876 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3877 aligned to an erase block boundary.
3879 - CONFIG_ENV_RANGE (optional):
3881 Specifies the length of the region in which the environment
3882 can be written. This should be a multiple of the NAND device's
3883 block size. Specifying a range with more erase blocks than
3884 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3885 the range to be avoided.
3887 - CONFIG_ENV_OFFSET_OOB (optional):
3889 Enables support for dynamically retrieving the offset of the
3890 environment from block zero's out-of-band data. The
3891 "nand env.oob" command can be used to record this offset.
3892 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3893 using CONFIG_ENV_OFFSET_OOB.
3895 - CONFIG_NAND_ENV_DST
3897 Defines address in RAM to which the nand_spl code should copy the
3898 environment. If redundant environment is used, it will be copied to
3899 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3901 - CONFIG_ENV_IS_IN_UBI:
3903 Define this if you have an UBI volume that you want to use for the
3904 environment. This has the benefit of wear-leveling the environment
3905 accesses, which is important on NAND.
3907 - CONFIG_ENV_UBI_PART:
3909 Define this to a string that is the mtd partition containing the UBI.
3911 - CONFIG_ENV_UBI_VOLUME:
3913 Define this to the name of the volume that you want to store the
3916 - CONFIG_ENV_UBI_VOLUME_REDUND:
3918 Define this to the name of another volume to store a second copy of
3919 the environment in. This will enable redundant environments in UBI.
3920 It is assumed that both volumes are in the same MTD partition.
3922 - CONFIG_UBI_SILENCE_MSG
3923 - CONFIG_UBIFS_SILENCE_MSG
3925 You will probably want to define these to avoid a really noisy system
3926 when storing the env in UBI.
3928 - CONFIG_ENV_IS_IN_MMC:
3930 Define this if you have an MMC device which you want to use for the
3933 - CONFIG_SYS_MMC_ENV_DEV:
3935 Specifies which MMC device the environment is stored in.
3937 - CONFIG_SYS_MMC_ENV_PART (optional):
3939 Specifies which MMC partition the environment is stored in. If not
3940 set, defaults to partition 0, the user area. Common values might be
3941 1 (first MMC boot partition), 2 (second MMC boot partition).
3943 - CONFIG_ENV_OFFSET:
3946 These two #defines specify the offset and size of the environment
3947 area within the specified MMC device.
3949 If offset is positive (the usual case), it is treated as relative to
3950 the start of the MMC partition. If offset is negative, it is treated
3951 as relative to the end of the MMC partition. This can be useful if
3952 your board may be fitted with different MMC devices, which have
3953 different sizes for the MMC partitions, and you always want the
3954 environment placed at the very end of the partition, to leave the
3955 maximum possible space before it, to store other data.
3957 These two values are in units of bytes, but must be aligned to an
3958 MMC sector boundary.
3960 - CONFIG_ENV_OFFSET_REDUND (optional):
3962 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3963 hold a redundant copy of the environment data. This provides a
3964 valid backup copy in case the other copy is corrupted, e.g. due
3965 to a power failure during a "saveenv" operation.
3967 This value may also be positive or negative; this is handled in the
3968 same way as CONFIG_ENV_OFFSET.
3970 This value is also in units of bytes, but must also be aligned to
3971 an MMC sector boundary.
3973 - CONFIG_ENV_SIZE_REDUND (optional):
3975 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3976 set. If this value is set, it must be set to the same value as
3979 - CONFIG_SYS_SPI_INIT_OFFSET
3981 Defines offset to the initial SPI buffer area in DPRAM. The
3982 area is used at an early stage (ROM part) if the environment
3983 is configured to reside in the SPI EEPROM: We need a 520 byte
3984 scratch DPRAM area. It is used between the two initialization
3985 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3986 to be a good choice since it makes it far enough from the
3987 start of the data area as well as from the stack pointer.
3989 Please note that the environment is read-only until the monitor
3990 has been relocated to RAM and a RAM copy of the environment has been
3991 created; also, when using EEPROM you will have to use getenv_f()
3992 until then to read environment variables.
3994 The environment is protected by a CRC32 checksum. Before the monitor
3995 is relocated into RAM, as a result of a bad CRC you will be working
3996 with the compiled-in default environment - *silently*!!! [This is
3997 necessary, because the first environment variable we need is the
3998 "baudrate" setting for the console - if we have a bad CRC, we don't
3999 have any device yet where we could complain.]
4001 Note: once the monitor has been relocated, then it will complain if
4002 the default environment is used; a new CRC is computed as soon as you
4003 use the "saveenv" command to store a valid environment.
4005 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4006 Echo the inverted Ethernet link state to the fault LED.
4008 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4009 also needs to be defined.
4011 - CONFIG_SYS_FAULT_MII_ADDR:
4012 MII address of the PHY to check for the Ethernet link state.
4014 - CONFIG_NS16550_MIN_FUNCTIONS:
4015 Define this if you desire to only have use of the NS16550_init
4016 and NS16550_putc functions for the serial driver located at
4017 drivers/serial/ns16550.c. This option is useful for saving
4018 space for already greatly restricted images, including but not
4019 limited to NAND_SPL configurations.
4021 - CONFIG_DISPLAY_BOARDINFO
4022 Display information about the board that U-Boot is running on
4023 when U-Boot starts up. The board function checkboard() is called
4026 - CONFIG_DISPLAY_BOARDINFO_LATE
4027 Similar to the previous option, but display this information
4028 later, once stdio is running and output goes to the LCD, if
4031 Low Level (hardware related) configuration options:
4032 ---------------------------------------------------
4034 - CONFIG_SYS_CACHELINE_SIZE:
4035 Cache Line Size of the CPU.
4037 - CONFIG_SYS_DEFAULT_IMMR:
4038 Default address of the IMMR after system reset.
4040 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4041 and RPXsuper) to be able to adjust the position of
4042 the IMMR register after a reset.
4044 - CONFIG_SYS_CCSRBAR_DEFAULT:
4045 Default (power-on reset) physical address of CCSR on Freescale
4048 - CONFIG_SYS_CCSRBAR:
4049 Virtual address of CCSR. On a 32-bit build, this is typically
4050 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4052 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4053 for cross-platform code that uses that macro instead.
4055 - CONFIG_SYS_CCSRBAR_PHYS:
4056 Physical address of CCSR. CCSR can be relocated to a new
4057 physical address, if desired. In this case, this macro should
4058 be set to that address. Otherwise, it should be set to the
4059 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4060 is typically relocated on 36-bit builds. It is recommended
4061 that this macro be defined via the _HIGH and _LOW macros:
4063 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4064 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4066 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4067 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4068 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4069 used in assembly code, so it must not contain typecasts or
4070 integer size suffixes (e.g. "ULL").
4072 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4073 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4074 used in assembly code, so it must not contain typecasts or
4075 integer size suffixes (e.g. "ULL").
4077 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4078 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4079 forced to a value that ensures that CCSR is not relocated.
4081 - Floppy Disk Support:
4082 CONFIG_SYS_FDC_DRIVE_NUMBER
4084 the default drive number (default value 0)
4086 CONFIG_SYS_ISA_IO_STRIDE
4088 defines the spacing between FDC chipset registers
4091 CONFIG_SYS_ISA_IO_OFFSET
4093 defines the offset of register from address. It
4094 depends on which part of the data bus is connected to
4095 the FDC chipset. (default value 0)
4097 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4098 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4101 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4102 fdc_hw_init() is called at the beginning of the FDC
4103 setup. fdc_hw_init() must be provided by the board
4104 source code. It is used to make hardware dependant
4108 Most IDE controllers were designed to be connected with PCI
4109 interface. Only few of them were designed for AHB interface.
4110 When software is doing ATA command and data transfer to
4111 IDE devices through IDE-AHB controller, some additional
4112 registers accessing to these kind of IDE-AHB controller
4115 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4116 DO NOT CHANGE unless you know exactly what you're
4117 doing! (11-4) [MPC8xx/82xx systems only]
4119 - CONFIG_SYS_INIT_RAM_ADDR:
4121 Start address of memory area that can be used for
4122 initial data and stack; please note that this must be
4123 writable memory that is working WITHOUT special
4124 initialization, i. e. you CANNOT use normal RAM which
4125 will become available only after programming the
4126 memory controller and running certain initialization
4129 U-Boot uses the following memory types:
4130 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4131 - MPC824X: data cache
4132 - PPC4xx: data cache
4134 - CONFIG_SYS_GBL_DATA_OFFSET:
4136 Offset of the initial data structure in the memory
4137 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4138 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4139 data is located at the end of the available space
4140 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4141 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4142 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4143 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4146 On the MPC824X (or other systems that use the data
4147 cache for initial memory) the address chosen for
4148 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4149 point to an otherwise UNUSED address space between
4150 the top of RAM and the start of the PCI space.
4152 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4154 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4156 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4158 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4160 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4162 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4164 - CONFIG_SYS_OR_TIMING_SDRAM:
4167 - CONFIG_SYS_MAMR_PTA:
4168 periodic timer for refresh
4170 - CONFIG_SYS_DER: Debug Event Register (37-47)
4172 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4173 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4174 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4175 CONFIG_SYS_BR1_PRELIM:
4176 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4178 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4179 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4180 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4181 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4183 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4184 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4185 Machine Mode Register and Memory Periodic Timer
4186 Prescaler definitions (SDRAM timing)
4188 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4189 enable I2C microcode relocation patch (MPC8xx);
4190 define relocation offset in DPRAM [DSP2]
4192 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4193 enable SMC microcode relocation patch (MPC8xx);
4194 define relocation offset in DPRAM [SMC1]
4196 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4197 enable SPI microcode relocation patch (MPC8xx);
4198 define relocation offset in DPRAM [SCC4]
4200 - CONFIG_SYS_USE_OSCCLK:
4201 Use OSCM clock mode on MBX8xx board. Be careful,
4202 wrong setting might damage your board. Read
4203 doc/README.MBX before setting this variable!
4205 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4206 Offset of the bootmode word in DPRAM used by post
4207 (Power On Self Tests). This definition overrides
4208 #define'd default value in commproc.h resp.
4211 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4212 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4213 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4214 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4215 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4216 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4217 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4218 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4219 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4221 - CONFIG_PCI_DISABLE_PCIE:
4222 Disable PCI-Express on systems where it is supported but not
4225 - CONFIG_PCI_ENUM_ONLY
4226 Only scan through and get the devices on the busses.
4227 Don't do any setup work, presumably because someone or
4228 something has already done it, and we don't need to do it
4229 a second time. Useful for platforms that are pre-booted
4230 by coreboot or similar.
4232 - CONFIG_PCI_INDIRECT_BRIDGE:
4233 Enable support for indirect PCI bridges.
4236 Chip has SRIO or not
4239 Board has SRIO 1 port available
4242 Board has SRIO 2 port available
4244 - CONFIG_SRIO_PCIE_BOOT_MASTER
4245 Board can support master function for Boot from SRIO and PCIE
4247 - CONFIG_SYS_SRIOn_MEM_VIRT:
4248 Virtual Address of SRIO port 'n' memory region
4250 - CONFIG_SYS_SRIOn_MEM_PHYS:
4251 Physical Address of SRIO port 'n' memory region
4253 - CONFIG_SYS_SRIOn_MEM_SIZE:
4254 Size of SRIO port 'n' memory region
4256 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4257 Defined to tell the NAND controller that the NAND chip is using
4259 Not all NAND drivers use this symbol.
4260 Example of drivers that use it:
4261 - drivers/mtd/nand/ndfc.c
4262 - drivers/mtd/nand/mxc_nand.c
4264 - CONFIG_SYS_NDFC_EBC0_CFG
4265 Sets the EBC0_CFG register for the NDFC. If not defined
4266 a default value will be used.
4269 Get DDR timing information from an I2C EEPROM. Common
4270 with pluggable memory modules such as SODIMMs
4273 I2C address of the SPD EEPROM
4275 - CONFIG_SYS_SPD_BUS_NUM
4276 If SPD EEPROM is on an I2C bus other than the first
4277 one, specify here. Note that the value must resolve
4278 to something your driver can deal with.
4280 - CONFIG_SYS_DDR_RAW_TIMING
4281 Get DDR timing information from other than SPD. Common with
4282 soldered DDR chips onboard without SPD. DDR raw timing
4283 parameters are extracted from datasheet and hard-coded into
4284 header files or board specific files.
4286 - CONFIG_FSL_DDR_INTERACTIVE
4287 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4289 - CONFIG_SYS_83XX_DDR_USES_CS0
4290 Only for 83xx systems. If specified, then DDR should
4291 be configured using CS0 and CS1 instead of CS2 and CS3.
4293 - CONFIG_ETHER_ON_FEC[12]
4294 Define to enable FEC[12] on a 8xx series processor.
4296 - CONFIG_FEC[12]_PHY
4297 Define to the hardcoded PHY address which corresponds
4298 to the given FEC; i. e.
4299 #define CONFIG_FEC1_PHY 4
4300 means that the PHY with address 4 is connected to FEC1
4302 When set to -1, means to probe for first available.
4304 - CONFIG_FEC[12]_PHY_NORXERR
4305 The PHY does not have a RXERR line (RMII only).
4306 (so program the FEC to ignore it).
4309 Enable RMII mode for all FECs.
4310 Note that this is a global option, we can't
4311 have one FEC in standard MII mode and another in RMII mode.
4313 - CONFIG_CRC32_VERIFY
4314 Add a verify option to the crc32 command.
4317 => crc32 -v <address> <count> <crc32>
4319 Where address/count indicate a memory area
4320 and crc32 is the correct crc32 which the
4324 Add the "loopw" memory command. This only takes effect if
4325 the memory commands are activated globally (CONFIG_CMD_MEM).
4328 Add the "mdc" and "mwc" memory commands. These are cyclic
4333 This command will print 4 bytes (10,11,12,13) each 500 ms.
4335 => mwc.l 100 12345678 10
4336 This command will write 12345678 to address 100 all 10 ms.
4338 This only takes effect if the memory commands are activated
4339 globally (CONFIG_CMD_MEM).
4341 - CONFIG_SKIP_LOWLEVEL_INIT
4342 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4343 low level initializations (like setting up the memory
4344 controller) are omitted and/or U-Boot does not
4345 relocate itself into RAM.
4347 Normally this variable MUST NOT be defined. The only
4348 exception is when U-Boot is loaded (to RAM) by some
4349 other boot loader or by a debugger which performs
4350 these initializations itself.
4353 Modifies the behaviour of start.S when compiling a loader
4354 that is executed before the actual U-Boot. E.g. when
4355 compiling a NAND SPL.
4358 Modifies the behaviour of start.S when compiling a loader
4359 that is executed after the SPL and before the actual U-Boot.
4360 It is loaded by the SPL.
4362 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4363 Only for 85xx systems. If this variable is specified, the section
4364 .resetvec is not kept and the section .bootpg is placed in the
4365 previous 4k of the .text section.
4367 - CONFIG_ARCH_MAP_SYSMEM
4368 Generally U-Boot (and in particular the md command) uses
4369 effective address. It is therefore not necessary to regard
4370 U-Boot address as virtual addresses that need to be translated
4371 to physical addresses. However, sandbox requires this, since
4372 it maintains its own little RAM buffer which contains all
4373 addressable memory. This option causes some memory accesses
4374 to be mapped through map_sysmem() / unmap_sysmem().
4376 - CONFIG_USE_ARCH_MEMCPY
4377 CONFIG_USE_ARCH_MEMSET
4378 If these options are used a optimized version of memcpy/memset will
4379 be used if available. These functions may be faster under some
4380 conditions but may increase the binary size.
4382 - CONFIG_X86_RESET_VECTOR
4383 If defined, the x86 reset vector code is included. This is not
4384 needed when U-Boot is running from Coreboot.
4387 Defines the MPU clock speed (in MHz).
4389 NOTE : currently only supported on AM335x platforms.
4391 Freescale QE/FMAN Firmware Support:
4392 -----------------------------------
4394 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4395 loading of "firmware", which is encoded in the QE firmware binary format.
4396 This firmware often needs to be loaded during U-Boot booting, so macros
4397 are used to identify the storage device (NOR flash, SPI, etc) and the address
4400 - CONFIG_SYS_QE_FMAN_FW_ADDR
4401 The address in the storage device where the firmware is located. The
4402 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4405 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4406 The maximum possible size of the firmware. The firmware binary format
4407 has a field that specifies the actual size of the firmware, but it
4408 might not be possible to read any part of the firmware unless some
4409 local storage is allocated to hold the entire firmware first.
4411 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4412 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4413 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4414 virtual address in NOR flash.
4416 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4417 Specifies that QE/FMAN firmware is located in NAND flash.
4418 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4420 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4421 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4422 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4424 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4425 Specifies that QE/FMAN firmware is located on the primary SPI
4426 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4428 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4429 Specifies that QE/FMAN firmware is located in the remote (master)
4430 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4431 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4432 window->master inbound window->master LAW->the ucode address in
4433 master's memory space.
4435 Building the Software:
4436 ======================
4438 Building U-Boot has been tested in several native build environments
4439 and in many different cross environments. Of course we cannot support
4440 all possibly existing versions of cross development tools in all
4441 (potentially obsolete) versions. In case of tool chain problems we
4442 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4443 which is extensively used to build and test U-Boot.
4445 If you are not using a native environment, it is assumed that you
4446 have GNU cross compiling tools available in your path. In this case,
4447 you must set the environment variable CROSS_COMPILE in your shell.
4448 Note that no changes to the Makefile or any other source files are
4449 necessary. For example using the ELDK on a 4xx CPU, please enter:
4451 $ CROSS_COMPILE=ppc_4xx-
4452 $ export CROSS_COMPILE
4454 Note: If you wish to generate Windows versions of the utilities in
4455 the tools directory you can use the MinGW toolchain
4456 (http://www.mingw.org). Set your HOST tools to the MinGW
4457 toolchain and execute 'make tools'. For example:
4459 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4461 Binaries such as tools/mkimage.exe will be created which can
4462 be executed on computers running Windows.
4464 U-Boot is intended to be simple to build. After installing the
4465 sources you must configure U-Boot for one specific board type. This
4470 where "NAME_config" is the name of one of the existing configu-
4471 rations; see boards.cfg for supported names.
4473 Note: for some board special configuration names may exist; check if
4474 additional information is available from the board vendor; for
4475 instance, the TQM823L systems are available without (standard)
4476 or with LCD support. You can select such additional "features"
4477 when choosing the configuration, i. e.
4480 - will configure for a plain TQM823L, i. e. no LCD support
4482 make TQM823L_LCD_config
4483 - will configure for a TQM823L with U-Boot console on LCD
4488 Finally, type "make all", and you should get some working U-Boot
4489 images ready for download to / installation on your system:
4491 - "u-boot.bin" is a raw binary image
4492 - "u-boot" is an image in ELF binary format
4493 - "u-boot.srec" is in Motorola S-Record format
4495 By default the build is performed locally and the objects are saved
4496 in the source directory. One of the two methods can be used to change
4497 this behavior and build U-Boot to some external directory:
4499 1. Add O= to the make command line invocations:
4501 make O=/tmp/build distclean
4502 make O=/tmp/build NAME_config
4503 make O=/tmp/build all
4505 2. Set environment variable BUILD_DIR to point to the desired location:
4507 export BUILD_DIR=/tmp/build
4512 Note that the command line "O=" setting overrides the BUILD_DIR environment
4516 Please be aware that the Makefiles assume you are using GNU make, so
4517 for instance on NetBSD you might need to use "gmake" instead of
4521 If the system board that you have is not listed, then you will need
4522 to port U-Boot to your hardware platform. To do this, follow these
4525 1. Add a new configuration option for your board to the toplevel
4526 "boards.cfg" file, using the existing entries as examples.
4527 Follow the instructions there to keep the boards in order.
4528 2. Create a new directory to hold your board specific code. Add any
4529 files you need. In your board directory, you will need at least
4530 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4531 3. Create a new configuration file "include/configs/<board>.h" for
4533 3. If you're porting U-Boot to a new CPU, then also create a new
4534 directory to hold your CPU specific code. Add any files you need.
4535 4. Run "make <board>_config" with your new name.
4536 5. Type "make", and you should get a working "u-boot.srec" file
4537 to be installed on your target system.
4538 6. Debug and solve any problems that might arise.
4539 [Of course, this last step is much harder than it sounds.]
4542 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4543 ==============================================================
4545 If you have modified U-Boot sources (for instance added a new board
4546 or support for new devices, a new CPU, etc.) you are expected to
4547 provide feedback to the other developers. The feedback normally takes
4548 the form of a "patch", i. e. a context diff against a certain (latest
4549 official or latest in the git repository) version of U-Boot sources.
4551 But before you submit such a patch, please verify that your modifi-
4552 cation did not break existing code. At least make sure that *ALL* of
4553 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4554 just run the "MAKEALL" script, which will configure and build U-Boot
4555 for ALL supported system. Be warned, this will take a while. You can
4556 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4557 environment variable to the script, i. e. to use the ELDK cross tools
4560 CROSS_COMPILE=ppc_8xx- MAKEALL
4562 or to build on a native PowerPC system you can type
4564 CROSS_COMPILE=' ' MAKEALL
4566 When using the MAKEALL script, the default behaviour is to build
4567 U-Boot in the source directory. This location can be changed by
4568 setting the BUILD_DIR environment variable. Also, for each target
4569 built, the MAKEALL script saves two log files (<target>.ERR and
4570 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4571 location can be changed by setting the MAKEALL_LOGDIR environment
4572 variable. For example:
4574 export BUILD_DIR=/tmp/build
4575 export MAKEALL_LOGDIR=/tmp/log
4576 CROSS_COMPILE=ppc_8xx- MAKEALL
4578 With the above settings build objects are saved in the /tmp/build,
4579 log files are saved in the /tmp/log and the source tree remains clean
4580 during the whole build process.
4583 See also "U-Boot Porting Guide" below.
4586 Monitor Commands - Overview:
4587 ============================
4589 go - start application at address 'addr'
4590 run - run commands in an environment variable
4591 bootm - boot application image from memory
4592 bootp - boot image via network using BootP/TFTP protocol
4593 bootz - boot zImage from memory
4594 tftpboot- boot image via network using TFTP protocol
4595 and env variables "ipaddr" and "serverip"
4596 (and eventually "gatewayip")
4597 tftpput - upload a file via network using TFTP protocol
4598 rarpboot- boot image via network using RARP/TFTP protocol
4599 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4600 loads - load S-Record file over serial line
4601 loadb - load binary file over serial line (kermit mode)
4603 mm - memory modify (auto-incrementing)
4604 nm - memory modify (constant address)
4605 mw - memory write (fill)
4607 cmp - memory compare
4608 crc32 - checksum calculation
4609 i2c - I2C sub-system
4610 sspi - SPI utility commands
4611 base - print or set address offset
4612 printenv- print environment variables
4613 setenv - set environment variables
4614 saveenv - save environment variables to persistent storage
4615 protect - enable or disable FLASH write protection
4616 erase - erase FLASH memory
4617 flinfo - print FLASH memory information
4618 nand - NAND memory operations (see doc/README.nand)
4619 bdinfo - print Board Info structure
4620 iminfo - print header information for application image
4621 coninfo - print console devices and informations
4622 ide - IDE sub-system
4623 loop - infinite loop on address range
4624 loopw - infinite write loop on address range
4625 mtest - simple RAM test
4626 icache - enable or disable instruction cache
4627 dcache - enable or disable data cache
4628 reset - Perform RESET of the CPU
4629 echo - echo args to console
4630 version - print monitor version
4631 help - print online help
4632 ? - alias for 'help'
4635 Monitor Commands - Detailed Description:
4636 ========================================
4640 For now: just type "help <command>".
4643 Environment Variables:
4644 ======================
4646 U-Boot supports user configuration using Environment Variables which
4647 can be made persistent by saving to Flash memory.
4649 Environment Variables are set using "setenv", printed using
4650 "printenv", and saved to Flash using "saveenv". Using "setenv"
4651 without a value can be used to delete a variable from the
4652 environment. As long as you don't save the environment you are
4653 working with an in-memory copy. In case the Flash area containing the
4654 environment is erased by accident, a default environment is provided.
4656 Some configuration options can be set using Environment Variables.
4658 List of environment variables (most likely not complete):
4660 baudrate - see CONFIG_BAUDRATE
4662 bootdelay - see CONFIG_BOOTDELAY
4664 bootcmd - see CONFIG_BOOTCOMMAND
4666 bootargs - Boot arguments when booting an RTOS image
4668 bootfile - Name of the image to load with TFTP
4670 bootm_low - Memory range available for image processing in the bootm
4671 command can be restricted. This variable is given as
4672 a hexadecimal number and defines lowest address allowed
4673 for use by the bootm command. See also "bootm_size"
4674 environment variable. Address defined by "bootm_low" is
4675 also the base of the initial memory mapping for the Linux
4676 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4679 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4680 This variable is given as a hexadecimal number and it
4681 defines the size of the memory region starting at base
4682 address bootm_low that is accessible by the Linux kernel
4683 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4684 as the default value if it is defined, and bootm_size is
4687 bootm_size - Memory range available for image processing in the bootm
4688 command can be restricted. This variable is given as
4689 a hexadecimal number and defines the size of the region
4690 allowed for use by the bootm command. See also "bootm_low"
4691 environment variable.
4693 updatefile - Location of the software update file on a TFTP server, used
4694 by the automatic software update feature. Please refer to
4695 documentation in doc/README.update for more details.
4697 autoload - if set to "no" (any string beginning with 'n'),
4698 "bootp" will just load perform a lookup of the
4699 configuration from the BOOTP server, but not try to
4700 load any image using TFTP
4702 autostart - if set to "yes", an image loaded using the "bootp",
4703 "rarpboot", "tftpboot" or "diskboot" commands will
4704 be automatically started (by internally calling
4707 If set to "no", a standalone image passed to the
4708 "bootm" command will be copied to the load address
4709 (and eventually uncompressed), but NOT be started.
4710 This can be used to load and uncompress arbitrary
4713 fdt_high - if set this restricts the maximum address that the
4714 flattened device tree will be copied into upon boot.
4715 For example, if you have a system with 1 GB memory
4716 at physical address 0x10000000, while Linux kernel
4717 only recognizes the first 704 MB as low memory, you
4718 may need to set fdt_high as 0x3C000000 to have the
4719 device tree blob be copied to the maximum address
4720 of the 704 MB low memory, so that Linux kernel can
4721 access it during the boot procedure.
4723 If this is set to the special value 0xFFFFFFFF then
4724 the fdt will not be copied at all on boot. For this
4725 to work it must reside in writable memory, have
4726 sufficient padding on the end of it for u-boot to
4727 add the information it needs into it, and the memory
4728 must be accessible by the kernel.
4730 fdtcontroladdr- if set this is the address of the control flattened
4731 device tree used by U-Boot when CONFIG_OF_CONTROL is
4734 i2cfast - (PPC405GP|PPC405EP only)
4735 if set to 'y' configures Linux I2C driver for fast
4736 mode (400kHZ). This environment variable is used in
4737 initialization code. So, for changes to be effective
4738 it must be saved and board must be reset.
4740 initrd_high - restrict positioning of initrd images:
4741 If this variable is not set, initrd images will be
4742 copied to the highest possible address in RAM; this
4743 is usually what you want since it allows for
4744 maximum initrd size. If for some reason you want to
4745 make sure that the initrd image is loaded below the
4746 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4747 variable to a value of "no" or "off" or "0".
4748 Alternatively, you can set it to a maximum upper
4749 address to use (U-Boot will still check that it
4750 does not overwrite the U-Boot stack and data).
4752 For instance, when you have a system with 16 MB
4753 RAM, and want to reserve 4 MB from use by Linux,
4754 you can do this by adding "mem=12M" to the value of
4755 the "bootargs" variable. However, now you must make
4756 sure that the initrd image is placed in the first
4757 12 MB as well - this can be done with
4759 setenv initrd_high 00c00000
4761 If you set initrd_high to 0xFFFFFFFF, this is an
4762 indication to U-Boot that all addresses are legal
4763 for the Linux kernel, including addresses in flash
4764 memory. In this case U-Boot will NOT COPY the
4765 ramdisk at all. This may be useful to reduce the
4766 boot time on your system, but requires that this
4767 feature is supported by your Linux kernel.
4769 ipaddr - IP address; needed for tftpboot command
4771 loadaddr - Default load address for commands like "bootp",
4772 "rarpboot", "tftpboot", "loadb" or "diskboot"
4774 loads_echo - see CONFIG_LOADS_ECHO
4776 serverip - TFTP server IP address; needed for tftpboot command
4778 bootretry - see CONFIG_BOOT_RETRY_TIME
4780 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4782 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4784 ethprime - controls which interface is used first.
4786 ethact - controls which interface is currently active.
4787 For example you can do the following
4789 => setenv ethact FEC
4790 => ping 192.168.0.1 # traffic sent on FEC
4791 => setenv ethact SCC
4792 => ping 10.0.0.1 # traffic sent on SCC
4794 ethrotate - When set to "no" U-Boot does not go through all
4795 available network interfaces.
4796 It just stays at the currently selected interface.
4798 netretry - When set to "no" each network operation will
4799 either succeed or fail without retrying.
4800 When set to "once" the network operation will
4801 fail when all the available network interfaces
4802 are tried once without success.
4803 Useful on scripts which control the retry operation
4806 npe_ucode - set load address for the NPE microcode
4808 silent_linux - If set then linux will be told to boot silently, by
4809 changing the console to be empty. If "yes" it will be
4810 made silent. If "no" it will not be made silent. If
4811 unset, then it will be made silent if the U-Boot console
4814 tftpsrcport - If this is set, the value is used for TFTP's
4817 tftpdstport - If this is set, the value is used for TFTP's UDP
4818 destination port instead of the Well Know Port 69.
4820 tftpblocksize - Block size to use for TFTP transfers; if not set,
4821 we use the TFTP server's default block size
4823 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4824 seconds, minimum value is 1000 = 1 second). Defines
4825 when a packet is considered to be lost so it has to
4826 be retransmitted. The default is 5000 = 5 seconds.
4827 Lowering this value may make downloads succeed
4828 faster in networks with high packet loss rates or
4829 with unreliable TFTP servers.
4831 vlan - When set to a value < 4095 the traffic over
4832 Ethernet is encapsulated/received over 802.1q
4835 The following image location variables contain the location of images
4836 used in booting. The "Image" column gives the role of the image and is
4837 not an environment variable name. The other columns are environment
4838 variable names. "File Name" gives the name of the file on a TFTP
4839 server, "RAM Address" gives the location in RAM the image will be
4840 loaded to, and "Flash Location" gives the image's address in NOR
4841 flash or offset in NAND flash.
4843 *Note* - these variables don't have to be defined for all boards, some
4844 boards currenlty use other variables for these purposes, and some
4845 boards use these variables for other purposes.
4847 Image File Name RAM Address Flash Location
4848 ----- --------- ----------- --------------
4849 u-boot u-boot u-boot_addr_r u-boot_addr
4850 Linux kernel bootfile kernel_addr_r kernel_addr
4851 device tree blob fdtfile fdt_addr_r fdt_addr
4852 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4854 The following environment variables may be used and automatically
4855 updated by the network boot commands ("bootp" and "rarpboot"),
4856 depending the information provided by your boot server:
4858 bootfile - see above
4859 dnsip - IP address of your Domain Name Server
4860 dnsip2 - IP address of your secondary Domain Name Server
4861 gatewayip - IP address of the Gateway (Router) to use
4862 hostname - Target hostname
4864 netmask - Subnet Mask
4865 rootpath - Pathname of the root filesystem on the NFS server
4866 serverip - see above
4869 There are two special Environment Variables:
4871 serial# - contains hardware identification information such
4872 as type string and/or serial number
4873 ethaddr - Ethernet address
4875 These variables can be set only once (usually during manufacturing of
4876 the board). U-Boot refuses to delete or overwrite these variables
4877 once they have been set once.
4880 Further special Environment Variables:
4882 ver - Contains the U-Boot version string as printed
4883 with the "version" command. This variable is
4884 readonly (see CONFIG_VERSION_VARIABLE).
4887 Please note that changes to some configuration parameters may take
4888 only effect after the next boot (yes, that's just like Windoze :-).
4891 Callback functions for environment variables:
4892 ---------------------------------------------
4894 For some environment variables, the behavior of u-boot needs to change
4895 when their values are changed. This functionailty allows functions to
4896 be associated with arbitrary variables. On creation, overwrite, or
4897 deletion, the callback will provide the opportunity for some side
4898 effect to happen or for the change to be rejected.
4900 The callbacks are named and associated with a function using the
4901 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4903 These callbacks are associated with variables in one of two ways. The
4904 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4905 in the board configuration to a string that defines a list of
4906 associations. The list must be in the following format:
4908 entry = variable_name[:callback_name]
4911 If the callback name is not specified, then the callback is deleted.
4912 Spaces are also allowed anywhere in the list.
4914 Callbacks can also be associated by defining the ".callbacks" variable
4915 with the same list format above. Any association in ".callbacks" will
4916 override any association in the static list. You can define
4917 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4918 ".callbacks" envirnoment variable in the default or embedded environment.
4921 Command Line Parsing:
4922 =====================
4924 There are two different command line parsers available with U-Boot:
4925 the old "simple" one, and the much more powerful "hush" shell:
4927 Old, simple command line parser:
4928 --------------------------------
4930 - supports environment variables (through setenv / saveenv commands)
4931 - several commands on one line, separated by ';'
4932 - variable substitution using "... ${name} ..." syntax
4933 - special characters ('$', ';') can be escaped by prefixing with '\',
4935 setenv bootcmd bootm \${address}
4936 - You can also escape text by enclosing in single apostrophes, for example:
4937 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4942 - similar to Bourne shell, with control structures like
4943 if...then...else...fi, for...do...done; while...do...done,
4944 until...do...done, ...
4945 - supports environment ("global") variables (through setenv / saveenv
4946 commands) and local shell variables (through standard shell syntax
4947 "name=value"); only environment variables can be used with "run"
4953 (1) If a command line (or an environment variable executed by a "run"
4954 command) contains several commands separated by semicolon, and
4955 one of these commands fails, then the remaining commands will be
4958 (2) If you execute several variables with one call to run (i. e.
4959 calling run with a list of variables as arguments), any failing
4960 command will cause "run" to terminate, i. e. the remaining
4961 variables are not executed.
4963 Note for Redundant Ethernet Interfaces:
4964 =======================================
4966 Some boards come with redundant Ethernet interfaces; U-Boot supports
4967 such configurations and is capable of automatic selection of a
4968 "working" interface when needed. MAC assignment works as follows:
4970 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4971 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4972 "eth1addr" (=>eth1), "eth2addr", ...
4974 If the network interface stores some valid MAC address (for instance
4975 in SROM), this is used as default address if there is NO correspon-
4976 ding setting in the environment; if the corresponding environment
4977 variable is set, this overrides the settings in the card; that means:
4979 o If the SROM has a valid MAC address, and there is no address in the
4980 environment, the SROM's address is used.
4982 o If there is no valid address in the SROM, and a definition in the
4983 environment exists, then the value from the environment variable is
4986 o If both the SROM and the environment contain a MAC address, and
4987 both addresses are the same, this MAC address is used.
4989 o If both the SROM and the environment contain a MAC address, and the
4990 addresses differ, the value from the environment is used and a
4993 o If neither SROM nor the environment contain a MAC address, an error
4996 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4997 will be programmed into hardware as part of the initialization process. This
4998 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4999 The naming convention is as follows:
5000 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5005 U-Boot is capable of booting (and performing other auxiliary operations on)
5006 images in two formats:
5008 New uImage format (FIT)
5009 -----------------------
5011 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5012 to Flattened Device Tree). It allows the use of images with multiple
5013 components (several kernels, ramdisks, etc.), with contents protected by
5014 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5020 Old image format is based on binary files which can be basically anything,
5021 preceded by a special header; see the definitions in include/image.h for
5022 details; basically, the header defines the following image properties:
5024 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5025 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5026 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5027 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5029 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5030 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5031 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5032 * Compression Type (uncompressed, gzip, bzip2)
5038 The header is marked by a special Magic Number, and both the header
5039 and the data portions of the image are secured against corruption by
5046 Although U-Boot should support any OS or standalone application
5047 easily, the main focus has always been on Linux during the design of
5050 U-Boot includes many features that so far have been part of some
5051 special "boot loader" code within the Linux kernel. Also, any
5052 "initrd" images to be used are no longer part of one big Linux image;
5053 instead, kernel and "initrd" are separate images. This implementation
5054 serves several purposes:
5056 - the same features can be used for other OS or standalone
5057 applications (for instance: using compressed images to reduce the
5058 Flash memory footprint)
5060 - it becomes much easier to port new Linux kernel versions because
5061 lots of low-level, hardware dependent stuff are done by U-Boot
5063 - the same Linux kernel image can now be used with different "initrd"
5064 images; of course this also means that different kernel images can
5065 be run with the same "initrd". This makes testing easier (you don't
5066 have to build a new "zImage.initrd" Linux image when you just
5067 change a file in your "initrd"). Also, a field-upgrade of the
5068 software is easier now.
5074 Porting Linux to U-Boot based systems:
5075 ---------------------------------------
5077 U-Boot cannot save you from doing all the necessary modifications to
5078 configure the Linux device drivers for use with your target hardware
5079 (no, we don't intend to provide a full virtual machine interface to
5082 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5084 Just make sure your machine specific header file (for instance
5085 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5086 Information structure as we define in include/asm-<arch>/u-boot.h,
5087 and make sure that your definition of IMAP_ADDR uses the same value
5088 as your U-Boot configuration in CONFIG_SYS_IMMR.
5091 Configuring the Linux kernel:
5092 -----------------------------
5094 No specific requirements for U-Boot. Make sure you have some root
5095 device (initial ramdisk, NFS) for your target system.
5098 Building a Linux Image:
5099 -----------------------
5101 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5102 not used. If you use recent kernel source, a new build target
5103 "uImage" will exist which automatically builds an image usable by
5104 U-Boot. Most older kernels also have support for a "pImage" target,
5105 which was introduced for our predecessor project PPCBoot and uses a
5106 100% compatible format.
5115 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5116 encapsulate a compressed Linux kernel image with header information,
5117 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5119 * build a standard "vmlinux" kernel image (in ELF binary format):
5121 * convert the kernel into a raw binary image:
5123 ${CROSS_COMPILE}-objcopy -O binary \
5124 -R .note -R .comment \
5125 -S vmlinux linux.bin
5127 * compress the binary image:
5131 * package compressed binary image for U-Boot:
5133 mkimage -A ppc -O linux -T kernel -C gzip \
5134 -a 0 -e 0 -n "Linux Kernel Image" \
5135 -d linux.bin.gz uImage
5138 The "mkimage" tool can also be used to create ramdisk images for use
5139 with U-Boot, either separated from the Linux kernel image, or
5140 combined into one file. "mkimage" encapsulates the images with a 64
5141 byte header containing information about target architecture,
5142 operating system, image type, compression method, entry points, time
5143 stamp, CRC32 checksums, etc.
5145 "mkimage" can be called in two ways: to verify existing images and
5146 print the header information, or to build new images.
5148 In the first form (with "-l" option) mkimage lists the information
5149 contained in the header of an existing U-Boot image; this includes
5150 checksum verification:
5152 tools/mkimage -l image
5153 -l ==> list image header information
5155 The second form (with "-d" option) is used to build a U-Boot image
5156 from a "data file" which is used as image payload:
5158 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5159 -n name -d data_file image
5160 -A ==> set architecture to 'arch'
5161 -O ==> set operating system to 'os'
5162 -T ==> set image type to 'type'
5163 -C ==> set compression type 'comp'
5164 -a ==> set load address to 'addr' (hex)
5165 -e ==> set entry point to 'ep' (hex)
5166 -n ==> set image name to 'name'
5167 -d ==> use image data from 'datafile'
5169 Right now, all Linux kernels for PowerPC systems use the same load
5170 address (0x00000000), but the entry point address depends on the
5173 - 2.2.x kernels have the entry point at 0x0000000C,
5174 - 2.3.x and later kernels have the entry point at 0x00000000.
5176 So a typical call to build a U-Boot image would read:
5178 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5179 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5180 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5181 > examples/uImage.TQM850L
5182 Image Name: 2.4.4 kernel for TQM850L
5183 Created: Wed Jul 19 02:34:59 2000
5184 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5185 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5186 Load Address: 0x00000000
5187 Entry Point: 0x00000000
5189 To verify the contents of the image (or check for corruption):
5191 -> tools/mkimage -l examples/uImage.TQM850L
5192 Image Name: 2.4.4 kernel for TQM850L
5193 Created: Wed Jul 19 02:34:59 2000
5194 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5195 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5196 Load Address: 0x00000000
5197 Entry Point: 0x00000000
5199 NOTE: for embedded systems where boot time is critical you can trade
5200 speed for memory and install an UNCOMPRESSED image instead: this
5201 needs more space in Flash, but boots much faster since it does not
5202 need to be uncompressed:
5204 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5205 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5206 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5207 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5208 > examples/uImage.TQM850L-uncompressed
5209 Image Name: 2.4.4 kernel for TQM850L
5210 Created: Wed Jul 19 02:34:59 2000
5211 Image Type: PowerPC Linux Kernel Image (uncompressed)
5212 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5213 Load Address: 0x00000000
5214 Entry Point: 0x00000000
5217 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5218 when your kernel is intended to use an initial ramdisk:
5220 -> tools/mkimage -n 'Simple Ramdisk Image' \
5221 > -A ppc -O linux -T ramdisk -C gzip \
5222 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5223 Image Name: Simple Ramdisk Image
5224 Created: Wed Jan 12 14:01:50 2000
5225 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5226 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5227 Load Address: 0x00000000
5228 Entry Point: 0x00000000
5231 Installing a Linux Image:
5232 -------------------------
5234 To downloading a U-Boot image over the serial (console) interface,
5235 you must convert the image to S-Record format:
5237 objcopy -I binary -O srec examples/image examples/image.srec
5239 The 'objcopy' does not understand the information in the U-Boot
5240 image header, so the resulting S-Record file will be relative to
5241 address 0x00000000. To load it to a given address, you need to
5242 specify the target address as 'offset' parameter with the 'loads'
5245 Example: install the image to address 0x40100000 (which on the
5246 TQM8xxL is in the first Flash bank):
5248 => erase 40100000 401FFFFF
5254 ## Ready for S-Record download ...
5255 ~>examples/image.srec
5256 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5258 15989 15990 15991 15992
5259 [file transfer complete]
5261 ## Start Addr = 0x00000000
5264 You can check the success of the download using the 'iminfo' command;
5265 this includes a checksum verification so you can be sure no data
5266 corruption happened:
5270 ## Checking Image at 40100000 ...
5271 Image Name: 2.2.13 for initrd on TQM850L
5272 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5273 Data Size: 335725 Bytes = 327 kB = 0 MB
5274 Load Address: 00000000
5275 Entry Point: 0000000c
5276 Verifying Checksum ... OK
5282 The "bootm" command is used to boot an application that is stored in
5283 memory (RAM or Flash). In case of a Linux kernel image, the contents
5284 of the "bootargs" environment variable is passed to the kernel as
5285 parameters. You can check and modify this variable using the
5286 "printenv" and "setenv" commands:
5289 => printenv bootargs
5290 bootargs=root=/dev/ram
5292 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5294 => printenv bootargs
5295 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5298 ## Booting Linux kernel at 40020000 ...
5299 Image Name: 2.2.13 for NFS on TQM850L
5300 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5301 Data Size: 381681 Bytes = 372 kB = 0 MB
5302 Load Address: 00000000
5303 Entry Point: 0000000c
5304 Verifying Checksum ... OK
5305 Uncompressing Kernel Image ... OK
5306 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5307 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5308 time_init: decrementer frequency = 187500000/60
5309 Calibrating delay loop... 49.77 BogoMIPS
5310 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5313 If you want to boot a Linux kernel with initial RAM disk, you pass
5314 the memory addresses of both the kernel and the initrd image (PPBCOOT
5315 format!) to the "bootm" command:
5317 => imi 40100000 40200000
5319 ## Checking Image at 40100000 ...
5320 Image Name: 2.2.13 for initrd on TQM850L
5321 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5322 Data Size: 335725 Bytes = 327 kB = 0 MB
5323 Load Address: 00000000
5324 Entry Point: 0000000c
5325 Verifying Checksum ... OK
5327 ## Checking Image at 40200000 ...
5328 Image Name: Simple Ramdisk Image
5329 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5330 Data Size: 566530 Bytes = 553 kB = 0 MB
5331 Load Address: 00000000
5332 Entry Point: 00000000
5333 Verifying Checksum ... OK
5335 => bootm 40100000 40200000
5336 ## Booting Linux kernel at 40100000 ...
5337 Image Name: 2.2.13 for initrd on TQM850L
5338 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5339 Data Size: 335725 Bytes = 327 kB = 0 MB
5340 Load Address: 00000000
5341 Entry Point: 0000000c
5342 Verifying Checksum ... OK
5343 Uncompressing Kernel Image ... OK
5344 ## Loading RAMDisk Image at 40200000 ...
5345 Image Name: Simple Ramdisk Image
5346 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5347 Data Size: 566530 Bytes = 553 kB = 0 MB
5348 Load Address: 00000000
5349 Entry Point: 00000000
5350 Verifying Checksum ... OK
5351 Loading Ramdisk ... OK
5352 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5353 Boot arguments: root=/dev/ram
5354 time_init: decrementer frequency = 187500000/60
5355 Calibrating delay loop... 49.77 BogoMIPS
5357 RAMDISK: Compressed image found at block 0
5358 VFS: Mounted root (ext2 filesystem).
5362 Boot Linux and pass a flat device tree:
5365 First, U-Boot must be compiled with the appropriate defines. See the section
5366 titled "Linux Kernel Interface" above for a more in depth explanation. The
5367 following is an example of how to start a kernel and pass an updated
5373 oft=oftrees/mpc8540ads.dtb
5374 => tftp $oftaddr $oft
5375 Speed: 1000, full duplex
5377 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5378 Filename 'oftrees/mpc8540ads.dtb'.
5379 Load address: 0x300000
5382 Bytes transferred = 4106 (100a hex)
5383 => tftp $loadaddr $bootfile
5384 Speed: 1000, full duplex
5386 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5388 Load address: 0x200000
5389 Loading:############
5391 Bytes transferred = 1029407 (fb51f hex)
5396 => bootm $loadaddr - $oftaddr
5397 ## Booting image at 00200000 ...
5398 Image Name: Linux-2.6.17-dirty
5399 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5400 Data Size: 1029343 Bytes = 1005.2 kB
5401 Load Address: 00000000
5402 Entry Point: 00000000
5403 Verifying Checksum ... OK
5404 Uncompressing Kernel Image ... OK
5405 Booting using flat device tree at 0x300000
5406 Using MPC85xx ADS machine description
5407 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5411 More About U-Boot Image Types:
5412 ------------------------------
5414 U-Boot supports the following image types:
5416 "Standalone Programs" are directly runnable in the environment
5417 provided by U-Boot; it is expected that (if they behave
5418 well) you can continue to work in U-Boot after return from
5419 the Standalone Program.
5420 "OS Kernel Images" are usually images of some Embedded OS which
5421 will take over control completely. Usually these programs
5422 will install their own set of exception handlers, device
5423 drivers, set up the MMU, etc. - this means, that you cannot
5424 expect to re-enter U-Boot except by resetting the CPU.
5425 "RAMDisk Images" are more or less just data blocks, and their
5426 parameters (address, size) are passed to an OS kernel that is
5428 "Multi-File Images" contain several images, typically an OS
5429 (Linux) kernel image and one or more data images like
5430 RAMDisks. This construct is useful for instance when you want
5431 to boot over the network using BOOTP etc., where the boot
5432 server provides just a single image file, but you want to get
5433 for instance an OS kernel and a RAMDisk image.
5435 "Multi-File Images" start with a list of image sizes, each
5436 image size (in bytes) specified by an "uint32_t" in network
5437 byte order. This list is terminated by an "(uint32_t)0".
5438 Immediately after the terminating 0 follow the images, one by
5439 one, all aligned on "uint32_t" boundaries (size rounded up to
5440 a multiple of 4 bytes).
5442 "Firmware Images" are binary images containing firmware (like
5443 U-Boot or FPGA images) which usually will be programmed to
5446 "Script files" are command sequences that will be executed by
5447 U-Boot's command interpreter; this feature is especially
5448 useful when you configure U-Boot to use a real shell (hush)
5449 as command interpreter.
5451 Booting the Linux zImage:
5452 -------------------------
5454 On some platforms, it's possible to boot Linux zImage. This is done
5455 using the "bootz" command. The syntax of "bootz" command is the same
5456 as the syntax of "bootm" command.
5458 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5459 kernel with raw initrd images. The syntax is slightly different, the
5460 address of the initrd must be augmented by it's size, in the following
5461 format: "<initrd addres>:<initrd size>".
5467 One of the features of U-Boot is that you can dynamically load and
5468 run "standalone" applications, which can use some resources of
5469 U-Boot like console I/O functions or interrupt services.
5471 Two simple examples are included with the sources:
5476 'examples/hello_world.c' contains a small "Hello World" Demo
5477 application; it is automatically compiled when you build U-Boot.
5478 It's configured to run at address 0x00040004, so you can play with it
5482 ## Ready for S-Record download ...
5483 ~>examples/hello_world.srec
5484 1 2 3 4 5 6 7 8 9 10 11 ...
5485 [file transfer complete]
5487 ## Start Addr = 0x00040004
5489 => go 40004 Hello World! This is a test.
5490 ## Starting application at 0x00040004 ...
5501 Hit any key to exit ...
5503 ## Application terminated, rc = 0x0
5505 Another example, which demonstrates how to register a CPM interrupt
5506 handler with the U-Boot code, can be found in 'examples/timer.c'.
5507 Here, a CPM timer is set up to generate an interrupt every second.
5508 The interrupt service routine is trivial, just printing a '.'
5509 character, but this is just a demo program. The application can be
5510 controlled by the following keys:
5512 ? - print current values og the CPM Timer registers
5513 b - enable interrupts and start timer
5514 e - stop timer and disable interrupts
5515 q - quit application
5518 ## Ready for S-Record download ...
5519 ~>examples/timer.srec
5520 1 2 3 4 5 6 7 8 9 10 11 ...
5521 [file transfer complete]
5523 ## Start Addr = 0x00040004
5526 ## Starting application at 0x00040004 ...
5529 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5532 [q, b, e, ?] Set interval 1000000 us
5535 [q, b, e, ?] ........
5536 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5539 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5542 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5545 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5547 [q, b, e, ?] ...Stopping timer
5549 [q, b, e, ?] ## Application terminated, rc = 0x0
5555 Over time, many people have reported problems when trying to use the
5556 "minicom" terminal emulation program for serial download. I (wd)
5557 consider minicom to be broken, and recommend not to use it. Under
5558 Unix, I recommend to use C-Kermit for general purpose use (and
5559 especially for kermit binary protocol download ("loadb" command), and
5560 use "cu" for S-Record download ("loads" command). See
5561 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5562 for help with kermit.
5565 Nevertheless, if you absolutely want to use it try adding this
5566 configuration to your "File transfer protocols" section:
5568 Name Program Name U/D FullScr IO-Red. Multi
5569 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5570 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5576 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5577 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5579 Building requires a cross environment; it is known to work on
5580 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5581 need gmake since the Makefiles are not compatible with BSD make).
5582 Note that the cross-powerpc package does not install include files;
5583 attempting to build U-Boot will fail because <machine/ansi.h> is
5584 missing. This file has to be installed and patched manually:
5586 # cd /usr/pkg/cross/powerpc-netbsd/include
5588 # ln -s powerpc machine
5589 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5590 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5592 Native builds *don't* work due to incompatibilities between native
5593 and U-Boot include files.
5595 Booting assumes that (the first part of) the image booted is a
5596 stage-2 loader which in turn loads and then invokes the kernel
5597 proper. Loader sources will eventually appear in the NetBSD source
5598 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5599 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5602 Implementation Internals:
5603 =========================
5605 The following is not intended to be a complete description of every
5606 implementation detail. However, it should help to understand the
5607 inner workings of U-Boot and make it easier to port it to custom
5611 Initial Stack, Global Data:
5612 ---------------------------
5614 The implementation of U-Boot is complicated by the fact that U-Boot
5615 starts running out of ROM (flash memory), usually without access to
5616 system RAM (because the memory controller is not initialized yet).
5617 This means that we don't have writable Data or BSS segments, and BSS
5618 is not initialized as zero. To be able to get a C environment working
5619 at all, we have to allocate at least a minimal stack. Implementation
5620 options for this are defined and restricted by the CPU used: Some CPU
5621 models provide on-chip memory (like the IMMR area on MPC8xx and
5622 MPC826x processors), on others (parts of) the data cache can be
5623 locked as (mis-) used as memory, etc.
5625 Chris Hallinan posted a good summary of these issues to the
5626 U-Boot mailing list:
5628 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5630 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5633 Correct me if I'm wrong, folks, but the way I understand it
5634 is this: Using DCACHE as initial RAM for Stack, etc, does not
5635 require any physical RAM backing up the cache. The cleverness
5636 is that the cache is being used as a temporary supply of
5637 necessary storage before the SDRAM controller is setup. It's
5638 beyond the scope of this list to explain the details, but you
5639 can see how this works by studying the cache architecture and
5640 operation in the architecture and processor-specific manuals.
5642 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5643 is another option for the system designer to use as an
5644 initial stack/RAM area prior to SDRAM being available. Either
5645 option should work for you. Using CS 4 should be fine if your
5646 board designers haven't used it for something that would
5647 cause you grief during the initial boot! It is frequently not
5650 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5651 with your processor/board/system design. The default value
5652 you will find in any recent u-boot distribution in
5653 walnut.h should work for you. I'd set it to a value larger
5654 than your SDRAM module. If you have a 64MB SDRAM module, set
5655 it above 400_0000. Just make sure your board has no resources
5656 that are supposed to respond to that address! That code in
5657 start.S has been around a while and should work as is when
5658 you get the config right.
5663 It is essential to remember this, since it has some impact on the C
5664 code for the initialization procedures:
5666 * Initialized global data (data segment) is read-only. Do not attempt
5669 * Do not use any uninitialized global data (or implicitely initialized
5670 as zero data - BSS segment) at all - this is undefined, initiali-
5671 zation is performed later (when relocating to RAM).
5673 * Stack space is very limited. Avoid big data buffers or things like
5676 Having only the stack as writable memory limits means we cannot use
5677 normal global data to share information beween the code. But it
5678 turned out that the implementation of U-Boot can be greatly
5679 simplified by making a global data structure (gd_t) available to all
5680 functions. We could pass a pointer to this data as argument to _all_
5681 functions, but this would bloat the code. Instead we use a feature of
5682 the GCC compiler (Global Register Variables) to share the data: we
5683 place a pointer (gd) to the global data into a register which we
5684 reserve for this purpose.
5686 When choosing a register for such a purpose we are restricted by the
5687 relevant (E)ABI specifications for the current architecture, and by
5688 GCC's implementation.
5690 For PowerPC, the following registers have specific use:
5692 R2: reserved for system use
5693 R3-R4: parameter passing and return values
5694 R5-R10: parameter passing
5695 R13: small data area pointer
5699 (U-Boot also uses R12 as internal GOT pointer. r12
5700 is a volatile register so r12 needs to be reset when
5701 going back and forth between asm and C)
5703 ==> U-Boot will use R2 to hold a pointer to the global data
5705 Note: on PPC, we could use a static initializer (since the
5706 address of the global data structure is known at compile time),
5707 but it turned out that reserving a register results in somewhat
5708 smaller code - although the code savings are not that big (on
5709 average for all boards 752 bytes for the whole U-Boot image,
5710 624 text + 127 data).
5712 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5713 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5715 ==> U-Boot will use P3 to hold a pointer to the global data
5717 On ARM, the following registers are used:
5719 R0: function argument word/integer result
5720 R1-R3: function argument word
5721 R9: platform specific
5722 R10: stack limit (used only if stack checking is enabled)
5723 R11: argument (frame) pointer
5724 R12: temporary workspace
5727 R15: program counter
5729 ==> U-Boot will use R9 to hold a pointer to the global data
5731 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5733 On Nios II, the ABI is documented here:
5734 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5736 ==> U-Boot will use gp to hold a pointer to the global data
5738 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5739 to access small data sections, so gp is free.
5741 On NDS32, the following registers are used:
5743 R0-R1: argument/return
5745 R15: temporary register for assembler
5746 R16: trampoline register
5747 R28: frame pointer (FP)
5748 R29: global pointer (GP)
5749 R30: link register (LP)
5750 R31: stack pointer (SP)
5751 PC: program counter (PC)
5753 ==> U-Boot will use R10 to hold a pointer to the global data
5755 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5756 or current versions of GCC may "optimize" the code too much.
5761 U-Boot runs in system state and uses physical addresses, i.e. the
5762 MMU is not used either for address mapping nor for memory protection.
5764 The available memory is mapped to fixed addresses using the memory
5765 controller. In this process, a contiguous block is formed for each
5766 memory type (Flash, SDRAM, SRAM), even when it consists of several
5767 physical memory banks.
5769 U-Boot is installed in the first 128 kB of the first Flash bank (on
5770 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5771 booting and sizing and initializing DRAM, the code relocates itself
5772 to the upper end of DRAM. Immediately below the U-Boot code some
5773 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5774 configuration setting]. Below that, a structure with global Board
5775 Info data is placed, followed by the stack (growing downward).
5777 Additionally, some exception handler code is copied to the low 8 kB
5778 of DRAM (0x00000000 ... 0x00001FFF).
5780 So a typical memory configuration with 16 MB of DRAM could look like
5783 0x0000 0000 Exception Vector code
5786 0x0000 2000 Free for Application Use
5792 0x00FB FF20 Monitor Stack (Growing downward)
5793 0x00FB FFAC Board Info Data and permanent copy of global data
5794 0x00FC 0000 Malloc Arena
5797 0x00FE 0000 RAM Copy of Monitor Code
5798 ... eventually: LCD or video framebuffer
5799 ... eventually: pRAM (Protected RAM - unchanged by reset)
5800 0x00FF FFFF [End of RAM]
5803 System Initialization:
5804 ----------------------
5806 In the reset configuration, U-Boot starts at the reset entry point
5807 (on most PowerPC systems at address 0x00000100). Because of the reset
5808 configuration for CS0# this is a mirror of the onboard Flash memory.
5809 To be able to re-map memory U-Boot then jumps to its link address.
5810 To be able to implement the initialization code in C, a (small!)
5811 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5812 which provide such a feature like MPC8xx or MPC8260), or in a locked
5813 part of the data cache. After that, U-Boot initializes the CPU core,
5814 the caches and the SIU.
5816 Next, all (potentially) available memory banks are mapped using a
5817 preliminary mapping. For example, we put them on 512 MB boundaries
5818 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5819 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5820 programmed for SDRAM access. Using the temporary configuration, a
5821 simple memory test is run that determines the size of the SDRAM
5824 When there is more than one SDRAM bank, and the banks are of
5825 different size, the largest is mapped first. For equal size, the first
5826 bank (CS2#) is mapped first. The first mapping is always for address
5827 0x00000000, with any additional banks following immediately to create
5828 contiguous memory starting from 0.
5830 Then, the monitor installs itself at the upper end of the SDRAM area
5831 and allocates memory for use by malloc() and for the global Board
5832 Info data; also, the exception vector code is copied to the low RAM
5833 pages, and the final stack is set up.
5835 Only after this relocation will you have a "normal" C environment;
5836 until that you are restricted in several ways, mostly because you are
5837 running from ROM, and because the code will have to be relocated to a
5841 U-Boot Porting Guide:
5842 ----------------------
5844 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5848 int main(int argc, char *argv[])
5850 sighandler_t no_more_time;
5852 signal(SIGALRM, no_more_time);
5853 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5855 if (available_money > available_manpower) {
5856 Pay consultant to port U-Boot;
5860 Download latest U-Boot source;
5862 Subscribe to u-boot mailing list;
5865 email("Hi, I am new to U-Boot, how do I get started?");
5868 Read the README file in the top level directory;
5869 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5870 Read applicable doc/*.README;
5871 Read the source, Luke;
5872 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5875 if (available_money > toLocalCurrency ($2500))
5878 Add a lot of aggravation and time;
5880 if (a similar board exists) { /* hopefully... */
5881 cp -a board/<similar> board/<myboard>
5882 cp include/configs/<similar>.h include/configs/<myboard>.h
5884 Create your own board support subdirectory;
5885 Create your own board include/configs/<myboard>.h file;
5887 Edit new board/<myboard> files
5888 Edit new include/configs/<myboard>.h
5893 Add / modify source code;
5897 email("Hi, I am having problems...");
5899 Send patch file to the U-Boot email list;
5900 if (reasonable critiques)
5901 Incorporate improvements from email list code review;
5903 Defend code as written;
5909 void no_more_time (int sig)
5918 All contributions to U-Boot should conform to the Linux kernel
5919 coding style; see the file "Documentation/CodingStyle" and the script
5920 "scripts/Lindent" in your Linux kernel source directory.
5922 Source files originating from a different project (for example the
5923 MTD subsystem) are generally exempt from these guidelines and are not
5924 reformated to ease subsequent migration to newer versions of those
5927 Please note that U-Boot is implemented in C (and to some small parts in
5928 Assembler); no C++ is used, so please do not use C++ style comments (//)
5931 Please also stick to the following formatting rules:
5932 - remove any trailing white space
5933 - use TAB characters for indentation and vertical alignment, not spaces
5934 - make sure NOT to use DOS '\r\n' line feeds
5935 - do not add more than 2 consecutive empty lines to source files
5936 - do not add trailing empty lines to source files
5938 Submissions which do not conform to the standards may be returned
5939 with a request to reformat the changes.
5945 Since the number of patches for U-Boot is growing, we need to
5946 establish some rules. Submissions which do not conform to these rules
5947 may be rejected, even when they contain important and valuable stuff.
5949 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5952 see http://lists.denx.de/mailman/listinfo/u-boot
5954 When you send a patch, please include the following information with
5957 * For bug fixes: a description of the bug and how your patch fixes
5958 this bug. Please try to include a way of demonstrating that the
5959 patch actually fixes something.
5961 * For new features: a description of the feature and your
5964 * A CHANGELOG entry as plaintext (separate from the patch)
5966 * For major contributions, your entry to the CREDITS file
5968 * When you add support for a new board, don't forget to add a
5969 maintainer e-mail address to the boards.cfg file, too.
5971 * If your patch adds new configuration options, don't forget to
5972 document these in the README file.
5974 * The patch itself. If you are using git (which is *strongly*
5975 recommended) you can easily generate the patch using the
5976 "git format-patch". If you then use "git send-email" to send it to
5977 the U-Boot mailing list, you will avoid most of the common problems
5978 with some other mail clients.
5980 If you cannot use git, use "diff -purN OLD NEW". If your version of
5981 diff does not support these options, then get the latest version of
5984 The current directory when running this command shall be the parent
5985 directory of the U-Boot source tree (i. e. please make sure that
5986 your patch includes sufficient directory information for the
5989 We prefer patches as plain text. MIME attachments are discouraged,
5990 and compressed attachments must not be used.
5992 * If one logical set of modifications affects or creates several
5993 files, all these changes shall be submitted in a SINGLE patch file.
5995 * Changesets that contain different, unrelated modifications shall be
5996 submitted as SEPARATE patches, one patch per changeset.
6001 * Before sending the patch, run the MAKEALL script on your patched
6002 source tree and make sure that no errors or warnings are reported
6003 for any of the boards.
6005 * Keep your modifications to the necessary minimum: A patch
6006 containing several unrelated changes or arbitrary reformats will be
6007 returned with a request to re-formatting / split it.
6009 * If you modify existing code, make sure that your new code does not
6010 add to the memory footprint of the code ;-) Small is beautiful!
6011 When adding new features, these should compile conditionally only
6012 (using #ifdef), and the resulting code with the new feature
6013 disabled must not need more memory than the old code without your
6016 * Remember that there is a size limit of 100 kB per message on the
6017 u-boot mailing list. Bigger patches will be moderated. If they are
6018 reasonable and not too big, they will be acknowledged. But patches
6019 bigger than the size limit should be avoided.
projects / u-boot.git / blob