2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /ixp Files specific to Intel XScale IXP CPUs
145 /pxa Files specific to Intel XScale PXA CPUs
146 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
147 /lib Architecture specific library files
148 /avr32 Files generic to AVR32 architecture
149 /cpu CPU specific files
150 /lib Architecture specific library files
151 /blackfin Files generic to Analog Devices Blackfin architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /m68k Files generic to m68k architecture
155 /cpu CPU specific files
156 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 /lib Architecture specific library files
162 /microblaze Files generic to microblaze architecture
163 /cpu CPU specific files
164 /lib Architecture specific library files
165 /mips Files generic to MIPS architecture
166 /cpu CPU specific files
167 /mips32 Files specific to MIPS32 CPUs
168 /xburst Files specific to Ingenic XBurst CPUs
169 /lib Architecture specific library files
170 /nds32 Files generic to NDS32 architecture
171 /cpu CPU specific files
172 /n1213 Files specific to Andes Technology N1213 CPUs
173 /lib Architecture specific library files
174 /nios2 Files generic to Altera NIOS2 architecture
175 /cpu CPU specific files
176 /lib Architecture specific library files
177 /openrisc Files generic to OpenRISC architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /powerpc Files generic to PowerPC architecture
181 /cpu CPU specific files
182 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
183 /mpc5xx Files specific to Freescale MPC5xx CPUs
184 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
185 /mpc8xx Files specific to Freescale MPC8xx CPUs
186 /mpc824x Files specific to Freescale MPC824x CPUs
187 /mpc8260 Files specific to Freescale MPC8260 CPUs
188 /mpc85xx Files specific to Freescale MPC85xx CPUs
189 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
190 /lib Architecture specific library files
191 /sh Files generic to SH architecture
192 /cpu CPU specific files
193 /sh2 Files specific to sh2 CPUs
194 /sh3 Files specific to sh3 CPUs
195 /sh4 Files specific to sh4 CPUs
196 /lib Architecture specific library files
197 /sparc Files generic to SPARC architecture
198 /cpu CPU specific files
199 /leon2 Files specific to Gaisler LEON2 SPARC CPU
200 /leon3 Files specific to Gaisler LEON3 SPARC CPU
201 /lib Architecture specific library files
202 /x86 Files generic to x86 architecture
203 /cpu CPU specific files
204 /lib Architecture specific library files
205 /api Machine/arch independent API for external apps
206 /board Board dependent files
207 /common Misc architecture independent functions
208 /disk Code for disk drive partition handling
209 /doc Documentation (don't expect too much)
210 /drivers Commonly used device drivers
211 /dts Contains Makefile for building internal U-Boot fdt.
212 /examples Example code for standalone applications, etc.
213 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
214 /include Header Files
215 /lib Files generic to all architectures
216 /libfdt Library files to support flattened device trees
217 /lzma Library files to support LZMA decompression
218 /lzo Library files to support LZO decompression
220 /post Power On Self Test
221 /spl Secondary Program Loader framework
222 /tools Tools to build S-Record or U-Boot images, etc.
224 Software Configuration:
225 =======================
227 Configuration is usually done using C preprocessor defines; the
228 rationale behind that is to avoid dead code whenever possible.
230 There are two classes of configuration variables:
232 * Configuration _OPTIONS_:
233 These are selectable by the user and have names beginning with
236 * Configuration _SETTINGS_:
237 These depend on the hardware etc. and should not be meddled with if
238 you don't know what you're doing; they have names beginning with
241 Later we will add a configuration tool - probably similar to or even
242 identical to what's used for the Linux kernel. Right now, we have to
243 do the configuration by hand, which means creating some symbolic
244 links and editing some configuration files. We use the TQM8xxL boards
248 Selection of Processor Architecture and Board Type:
249 ---------------------------------------------------
251 For all supported boards there are ready-to-use default
252 configurations available; just type "make <board_name>_config".
254 Example: For a TQM823L module type:
259 For the Cogent platform, you need to specify the CPU type as well;
260 e.g. "make cogent_mpc8xx_config". And also configure the cogent
261 directory according to the instructions in cogent/README.
264 Configuration Options:
265 ----------------------
267 Configuration depends on the combination of board and CPU type; all
268 such information is kept in a configuration file
269 "include/configs/<board_name>.h".
271 Example: For a TQM823L module, all configuration settings are in
272 "include/configs/TQM823L.h".
275 Many of the options are named exactly as the corresponding Linux
276 kernel configuration options. The intention is to make it easier to
277 build a config tool - later.
280 The following options need to be configured:
282 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
284 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
286 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
287 Define exactly one, e.g. CONFIG_ATSTK1002
289 - CPU Module Type: (if CONFIG_COGENT is defined)
290 Define exactly one of
292 --- FIXME --- not tested yet:
293 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
294 CONFIG_CMA287_23, CONFIG_CMA287_50
296 - Motherboard Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
298 CONFIG_CMA101, CONFIG_CMA102
300 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
301 Define one or more of
304 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
305 Define one or more of
306 CONFIG_LCD_HEARTBEAT - update a character position on
307 the LCD display every second with
310 - Board flavour: (if CONFIG_MPC8260ADS is defined)
313 CONFIG_SYS_8260ADS - original MPC8260ADS
314 CONFIG_SYS_8266ADS - MPC8266ADS
315 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
316 CONFIG_SYS_8272ADS - MPC8272ADS
318 - Marvell Family Member
319 CONFIG_SYS_MVFS - define it if you want to enable
320 multiple fs option at one time
321 for marvell soc family
323 - MPC824X Family Member (if CONFIG_MPC824X is defined)
324 Define exactly one of
325 CONFIG_MPC8240, CONFIG_MPC8245
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 requred during NOR boot.
406 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
408 This is the value to write into CCSR offset 0x18600
409 according to the A004510 workaround.
411 CONFIG_SYS_FSL_DSP_DDR_ADDR
412 This value denotes start offset of DDR memory which is
413 connected exclusively to the DSP cores.
415 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
416 This value denotes start offset of M2 memory
417 which is directly connected to the DSP core.
419 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
420 This value denotes start offset of M3 memory which is directly
421 connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
424 This value denotes start offset of DSP CCSR space.
426 - 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
822 CONFIG_BOOTCOUNT_LIMIT
823 Implements a mechanism for detecting a repeating reboot
825 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
828 If no softreset save registers are found on the hardware
829 "bootcount" is stored in the environment. To prevent a
830 saveenv on all reboots, the environment variable
831 "upgrade_available" is used. If "upgrade_available" is
832 0, "bootcount" is always 0, if "upgrade_available" is
833 1 "bootcount" is incremented in the environment.
834 So the Userspace Applikation must set the "upgrade_available"
835 and "bootcount" variable to 0, if a boot was successfully.
840 When this option is #defined, the existence of the
841 environment variable "preboot" will be checked
842 immediately before starting the CONFIG_BOOTDELAY
843 countdown and/or running the auto-boot command resp.
844 entering interactive mode.
846 This feature is especially useful when "preboot" is
847 automatically generated or modified. For an example
848 see the LWMON board specific code: here "preboot" is
849 modified when the user holds down a certain
850 combination of keys on the (special) keyboard when
853 - Serial Download Echo Mode:
855 If defined to 1, all characters received during a
856 serial download (using the "loads" command) are
857 echoed back. This might be needed by some terminal
858 emulations (like "cu"), but may as well just take
859 time on others. This setting #define's the initial
860 value of the "loads_echo" environment variable.
862 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
864 Select one of the baudrates listed in
865 CONFIG_SYS_BAUDRATE_TABLE, see below.
868 Monitor commands can be included or excluded
869 from the build by using the #include files
870 <config_cmd_all.h> and #undef'ing unwanted
871 commands, or using <config_cmd_default.h>
872 and augmenting with additional #define's
875 The default command configuration includes all commands
876 except those marked below with a "*".
878 CONFIG_CMD_ASKENV * ask for env variable
879 CONFIG_CMD_BDI bdinfo
880 CONFIG_CMD_BEDBUG * Include BedBug Debugger
881 CONFIG_CMD_BMP * BMP support
882 CONFIG_CMD_BSP * Board specific commands
883 CONFIG_CMD_BOOTD bootd
884 CONFIG_CMD_CACHE * icache, dcache
885 CONFIG_CMD_CONSOLE coninfo
886 CONFIG_CMD_CRC32 * crc32
887 CONFIG_CMD_DATE * support for RTC, date/time...
888 CONFIG_CMD_DHCP * DHCP support
889 CONFIG_CMD_DIAG * Diagnostics
890 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
891 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
892 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
893 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
894 CONFIG_CMD_DTT * Digital Therm and Thermostat
895 CONFIG_CMD_ECHO echo arguments
896 CONFIG_CMD_EDITENV edit env variable
897 CONFIG_CMD_EEPROM * EEPROM read/write support
898 CONFIG_CMD_ELF * bootelf, bootvx
899 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
900 CONFIG_CMD_ENV_FLAGS * display details about env flags
901 CONFIG_CMD_ENV_EXISTS * check existence of env variable
902 CONFIG_CMD_EXPORTENV * export the environment
903 CONFIG_CMD_EXT2 * ext2 command support
904 CONFIG_CMD_EXT4 * ext4 command support
905 CONFIG_CMD_SAVEENV saveenv
906 CONFIG_CMD_FDC * Floppy Disk Support
907 CONFIG_CMD_FAT * FAT command support
908 CONFIG_CMD_FDOS * Dos diskette Support
909 CONFIG_CMD_FLASH flinfo, erase, protect
910 CONFIG_CMD_FPGA FPGA device initialization support
911 CONFIG_CMD_FUSE * Device fuse support
912 CONFIG_CMD_GETTIME * Get time since boot
913 CONFIG_CMD_GO * the 'go' command (exec code)
914 CONFIG_CMD_GREPENV * search environment
915 CONFIG_CMD_HASH * calculate hash / digest
916 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
917 CONFIG_CMD_I2C * I2C serial bus support
918 CONFIG_CMD_IDE * IDE harddisk support
919 CONFIG_CMD_IMI iminfo
920 CONFIG_CMD_IMLS List all images found in NOR flash
921 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
922 CONFIG_CMD_IMMAP * IMMR dump support
923 CONFIG_CMD_IMPORTENV * import an environment
924 CONFIG_CMD_INI * import data from an ini file into the env
925 CONFIG_CMD_IRQ * irqinfo
926 CONFIG_CMD_ITEST Integer/string test of 2 values
927 CONFIG_CMD_JFFS2 * JFFS2 Support
928 CONFIG_CMD_KGDB * kgdb
929 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
930 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
932 CONFIG_CMD_LOADB loadb
933 CONFIG_CMD_LOADS loads
934 CONFIG_CMD_MD5SUM * print md5 message digest
935 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
936 CONFIG_CMD_MEMINFO * Display detailed memory information
937 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
939 CONFIG_CMD_MEMTEST * mtest
940 CONFIG_CMD_MISC Misc functions like sleep etc
941 CONFIG_CMD_MMC * MMC memory mapped support
942 CONFIG_CMD_MII * MII utility commands
943 CONFIG_CMD_MTDPARTS * MTD partition support
944 CONFIG_CMD_NAND * NAND support
945 CONFIG_CMD_NET bootp, tftpboot, rarpboot
946 CONFIG_CMD_NFS NFS support
947 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
948 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
949 CONFIG_CMD_PCI * pciinfo
950 CONFIG_CMD_PCMCIA * PCMCIA support
951 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
953 CONFIG_CMD_PORTIO * Port I/O
954 CONFIG_CMD_READ * Read raw data from partition
955 CONFIG_CMD_REGINFO * Register dump
956 CONFIG_CMD_RUN run command in env variable
957 CONFIG_CMD_SANDBOX * sb command to access sandbox features
958 CONFIG_CMD_SAVES * save S record dump
959 CONFIG_CMD_SCSI * SCSI Support
960 CONFIG_CMD_SDRAM * print SDRAM configuration information
961 (requires CONFIG_CMD_I2C)
962 CONFIG_CMD_SETGETDCR Support for DCR Register access
964 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
965 CONFIG_CMD_SHA1SUM * print sha1 memory digest
966 (requires CONFIG_CMD_MEMORY)
967 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
968 CONFIG_CMD_SOURCE "source" command Support
969 CONFIG_CMD_SPI * SPI serial bus support
970 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
971 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
972 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
973 CONFIG_CMD_TIMER * access to the system tick timer
974 CONFIG_CMD_USB * USB support
975 CONFIG_CMD_CDP * Cisco Discover Protocol support
976 CONFIG_CMD_MFSL * Microblaze FSL support
977 CONFIG_CMD_XIMG Load part of Multi Image
980 EXAMPLE: If you want all functions except of network
981 support you can write:
983 #include "config_cmd_all.h"
984 #undef CONFIG_CMD_NET
987 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
989 Note: Don't enable the "icache" and "dcache" commands
990 (configuration option CONFIG_CMD_CACHE) unless you know
991 what you (and your U-Boot users) are doing. Data
992 cache cannot be enabled on systems like the 8xx or
993 8260 (where accesses to the IMMR region must be
994 uncached), and it cannot be disabled on all other
995 systems where we (mis-) use the data cache to hold an
996 initial stack and some data.
999 XXX - this list needs to get updated!
1001 - Regular expression support:
1003 If this variable is defined, U-Boot is linked against
1004 the SLRE (Super Light Regular Expression) library,
1005 which adds regex support to some commands, as for
1006 example "env grep" and "setexpr".
1010 If this variable is defined, U-Boot will use a device tree
1011 to configure its devices, instead of relying on statically
1012 compiled #defines in the board file. This option is
1013 experimental and only available on a few boards. The device
1014 tree is available in the global data as gd->fdt_blob.
1016 U-Boot needs to get its device tree from somewhere. This can
1017 be done using one of the two options below:
1020 If this variable is defined, U-Boot will embed a device tree
1021 binary in its image. This device tree file should be in the
1022 board directory and called <soc>-<board>.dts. The binary file
1023 is then picked up in board_init_f() and made available through
1024 the global data structure as gd->blob.
1027 If this variable is defined, U-Boot will build a device tree
1028 binary. It will be called u-boot.dtb. Architecture-specific
1029 code will locate it at run-time. Generally this works by:
1031 cat u-boot.bin u-boot.dtb >image.bin
1033 and in fact, U-Boot does this for you, creating a file called
1034 u-boot-dtb.bin which is useful in the common case. You can
1035 still use the individual files if you need something more
1040 If this variable is defined, it enables watchdog
1041 support for the SoC. There must be support in the SoC
1042 specific code for a watchdog. For the 8xx and 8260
1043 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1044 register. When supported for a specific SoC is
1045 available, then no further board specific code should
1046 be needed to use it.
1049 When using a watchdog circuitry external to the used
1050 SoC, then define this variable and provide board
1051 specific code for the "hw_watchdog_reset" function.
1054 CONFIG_VERSION_VARIABLE
1055 If this variable is defined, an environment variable
1056 named "ver" is created by U-Boot showing the U-Boot
1057 version as printed by the "version" command.
1058 Any change to this variable will be reverted at the
1063 When CONFIG_CMD_DATE is selected, the type of the RTC
1064 has to be selected, too. Define exactly one of the
1067 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1068 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1069 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1070 CONFIG_RTC_MC146818 - use MC146818 RTC
1071 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1072 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1073 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1074 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1075 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1076 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1077 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1078 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1081 Note that if the RTC uses I2C, then the I2C interface
1082 must also be configured. See I2C Support, below.
1085 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1087 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1088 chip-ngpio pairs that tell the PCA953X driver the number of
1089 pins supported by a particular chip.
1091 Note that if the GPIO device uses I2C, then the I2C interface
1092 must also be configured. See I2C Support, below.
1094 - Timestamp Support:
1096 When CONFIG_TIMESTAMP is selected, the timestamp
1097 (date and time) of an image is printed by image
1098 commands like bootm or iminfo. This option is
1099 automatically enabled when you select CONFIG_CMD_DATE .
1101 - Partition Labels (disklabels) Supported:
1102 Zero or more of the following:
1103 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1104 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1105 Intel architecture, USB sticks, etc.
1106 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1107 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1108 bootloader. Note 2TB partition limit; see
1110 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1112 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1113 CONFIG_CMD_SCSI) you must configure support for at
1114 least one non-MTD partition type as well.
1117 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1118 board configurations files but used nowhere!
1120 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1121 be performed by calling the function
1122 ide_set_reset(int reset)
1123 which has to be defined in a board specific file
1128 Set this to enable ATAPI support.
1133 Set this to enable support for disks larger than 137GB
1134 Also look at CONFIG_SYS_64BIT_LBA.
1135 Whithout these , LBA48 support uses 32bit variables and will 'only'
1136 support disks up to 2.1TB.
1138 CONFIG_SYS_64BIT_LBA:
1139 When enabled, makes the IDE subsystem use 64bit sector addresses.
1143 At the moment only there is only support for the
1144 SYM53C8XX SCSI controller; define
1145 CONFIG_SCSI_SYM53C8XX to enable it.
1147 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1148 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1149 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1150 maximum numbers of LUNs, SCSI ID's and target
1152 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1154 The environment variable 'scsidevs' is set to the number of
1155 SCSI devices found during the last scan.
1157 - NETWORK Support (PCI):
1159 Support for Intel 8254x/8257x gigabit chips.
1162 Utility code for direct access to the SPI bus on Intel 8257x.
1163 This does not do anything useful unless you set at least one
1164 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1166 CONFIG_E1000_SPI_GENERIC
1167 Allow generic access to the SPI bus on the Intel 8257x, for
1168 example with the "sspi" command.
1171 Management command for E1000 devices. When used on devices
1172 with SPI support you can reprogram the EEPROM from U-Boot.
1174 CONFIG_E1000_FALLBACK_MAC
1175 default MAC for empty EEPROM after production.
1178 Support for Intel 82557/82559/82559ER chips.
1179 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1180 write routine for first time initialisation.
1183 Support for Digital 2114x chips.
1184 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1185 modem chip initialisation (KS8761/QS6611).
1188 Support for National dp83815 chips.
1191 Support for National dp8382[01] gigabit chips.
1193 - NETWORK Support (other):
1195 CONFIG_DRIVER_AT91EMAC
1196 Support for AT91RM9200 EMAC.
1199 Define this to use reduced MII inteface
1201 CONFIG_DRIVER_AT91EMAC_QUIET
1202 If this defined, the driver is quiet.
1203 The driver doen't show link status messages.
1205 CONFIG_CALXEDA_XGMAC
1206 Support for the Calxeda XGMAC device
1209 Support for SMSC's LAN91C96 chips.
1211 CONFIG_LAN91C96_BASE
1212 Define this to hold the physical address
1213 of the LAN91C96's I/O space
1215 CONFIG_LAN91C96_USE_32_BIT
1216 Define this to enable 32 bit addressing
1219 Support for SMSC's LAN91C111 chip
1221 CONFIG_SMC91111_BASE
1222 Define this to hold the physical address
1223 of the device (I/O space)
1225 CONFIG_SMC_USE_32_BIT
1226 Define this if data bus is 32 bits
1228 CONFIG_SMC_USE_IOFUNCS
1229 Define this to use i/o functions instead of macros
1230 (some hardware wont work with macros)
1232 CONFIG_DRIVER_TI_EMAC
1233 Support for davinci emac
1235 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1236 Define this if you have more then 3 PHYs.
1239 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1241 CONFIG_FTGMAC100_EGIGA
1242 Define this to use GE link update with gigabit PHY.
1243 Define this if FTGMAC100 is connected to gigabit PHY.
1244 If your system has 10/100 PHY only, it might not occur
1245 wrong behavior. Because PHY usually return timeout or
1246 useless data when polling gigabit status and gigabit
1247 control registers. This behavior won't affect the
1248 correctnessof 10/100 link speed update.
1251 Support for SMSC's LAN911x and LAN921x chips
1254 Define this to hold the physical address
1255 of the device (I/O space)
1257 CONFIG_SMC911X_32_BIT
1258 Define this if data bus is 32 bits
1260 CONFIG_SMC911X_16_BIT
1261 Define this if data bus is 16 bits. If your processor
1262 automatically converts one 32 bit word to two 16 bit
1263 words you may also try CONFIG_SMC911X_32_BIT.
1266 Support for Renesas on-chip Ethernet controller
1268 CONFIG_SH_ETHER_USE_PORT
1269 Define the number of ports to be used
1271 CONFIG_SH_ETHER_PHY_ADDR
1272 Define the ETH PHY's address
1274 CONFIG_SH_ETHER_CACHE_WRITEBACK
1275 If this option is set, the driver enables cache flush.
1279 Support TPM devices.
1282 Support for i2c bus TPM devices. Only one device
1283 per system is supported at this time.
1285 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1286 Define the the i2c bus number for the TPM device
1288 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1289 Define the TPM's address on the i2c bus
1291 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1292 Define the burst count bytes upper limit
1294 CONFIG_TPM_ATMEL_TWI
1295 Support for Atmel TWI TPM device. Requires I2C support.
1298 Support for generic parallel port TPM devices. Only one device
1299 per system is supported at this time.
1301 CONFIG_TPM_TIS_BASE_ADDRESS
1302 Base address where the generic TPM device is mapped
1303 to. Contemporary x86 systems usually map it at
1307 Add tpm monitor functions.
1308 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1309 provides monitor access to authorized functions.
1312 Define this to enable the TPM support library which provides
1313 functional interfaces to some TPM commands.
1314 Requires support for a TPM device.
1316 CONFIG_TPM_AUTH_SESSIONS
1317 Define this to enable authorized functions in the TPM library.
1318 Requires CONFIG_TPM and CONFIG_SHA1.
1321 At the moment only the UHCI host controller is
1322 supported (PIP405, MIP405, MPC5200); define
1323 CONFIG_USB_UHCI to enable it.
1324 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1325 and define CONFIG_USB_STORAGE to enable the USB
1328 Supported are USB Keyboards and USB Floppy drives
1330 MPC5200 USB requires additional defines:
1332 for 528 MHz Clock: 0x0001bbbb
1336 for differential drivers: 0x00001000
1337 for single ended drivers: 0x00005000
1338 for differential drivers on PSC3: 0x00000100
1339 for single ended drivers on PSC3: 0x00004100
1340 CONFIG_SYS_USB_EVENT_POLL
1341 May be defined to allow interrupt polling
1342 instead of using asynchronous interrupts
1344 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1345 txfilltuning field in the EHCI controller on reset.
1347 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1348 interval for usb hub power-on delay.(minimum 100msec)
1351 Define the below if you wish to use the USB console.
1352 Once firmware is rebuilt from a serial console issue the
1353 command "setenv stdin usbtty; setenv stdout usbtty" and
1354 attach your USB cable. The Unix command "dmesg" should print
1355 it has found a new device. The environment variable usbtty
1356 can be set to gserial or cdc_acm to enable your device to
1357 appear to a USB host as a Linux gserial device or a
1358 Common Device Class Abstract Control Model serial device.
1359 If you select usbtty = gserial you should be able to enumerate
1361 # modprobe usbserial vendor=0xVendorID product=0xProductID
1362 else if using cdc_acm, simply setting the environment
1363 variable usbtty to be cdc_acm should suffice. The following
1364 might be defined in YourBoardName.h
1367 Define this to build a UDC device
1370 Define this to have a tty type of device available to
1371 talk to the UDC device
1374 Define this to enable the high speed support for usb
1375 device and usbtty. If this feature is enabled, a routine
1376 int is_usbd_high_speed(void)
1377 also needs to be defined by the driver to dynamically poll
1378 whether the enumeration has succeded at high speed or full
1381 CONFIG_SYS_CONSOLE_IS_IN_ENV
1382 Define this if you want stdin, stdout &/or stderr to
1386 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1387 Derive USB clock from external clock "blah"
1388 - CONFIG_SYS_USB_EXTC_CLK 0x02
1390 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1391 Derive USB clock from brgclk
1392 - CONFIG_SYS_USB_BRG_CLK 0x04
1394 If you have a USB-IF assigned VendorID then you may wish to
1395 define your own vendor specific values either in BoardName.h
1396 or directly in usbd_vendor_info.h. If you don't define
1397 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1398 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1399 should pretend to be a Linux device to it's target host.
1401 CONFIG_USBD_MANUFACTURER
1402 Define this string as the name of your company for
1403 - CONFIG_USBD_MANUFACTURER "my company"
1405 CONFIG_USBD_PRODUCT_NAME
1406 Define this string as the name of your product
1407 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1409 CONFIG_USBD_VENDORID
1410 Define this as your assigned Vendor ID from the USB
1411 Implementors Forum. This *must* be a genuine Vendor ID
1412 to avoid polluting the USB namespace.
1413 - CONFIG_USBD_VENDORID 0xFFFF
1415 CONFIG_USBD_PRODUCTID
1416 Define this as the unique Product ID
1418 - CONFIG_USBD_PRODUCTID 0xFFFF
1420 Some USB device drivers may need to check USB cable attachment.
1421 In this case you can enable following config in BoardName.h:
1422 CONFIG_USB_CABLE_CHECK
1423 This enables function definition:
1424 - usb_cable_connected() in include/usb.h
1425 Implementation of this function is board-specific.
1427 - ULPI Layer Support:
1428 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1429 the generic ULPI layer. The generic layer accesses the ULPI PHY
1430 via the platform viewport, so you need both the genric layer and
1431 the viewport enabled. Currently only Chipidea/ARC based
1432 viewport is supported.
1433 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1434 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1435 If your ULPI phy needs a different reference clock than the
1436 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1437 the appropriate value in Hz.
1440 The MMC controller on the Intel PXA is supported. To
1441 enable this define CONFIG_MMC. The MMC can be
1442 accessed from the boot prompt by mapping the device
1443 to physical memory similar to flash. Command line is
1444 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1445 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1448 Support for Renesas on-chip MMCIF controller
1450 CONFIG_SH_MMCIF_ADDR
1451 Define the base address of MMCIF registers
1454 Define the clock frequency for MMCIF
1456 - USB Device Firmware Update (DFU) class support:
1458 This enables the USB portion of the DFU USB class
1461 This enables the command "dfu" which is used to have
1462 U-Boot create a DFU class device via USB. This command
1463 requires that the "dfu_alt_info" environment variable be
1464 set and define the alt settings to expose to the host.
1467 This enables support for exposing (e)MMC devices via DFU.
1470 This enables support for exposing NAND devices via DFU.
1473 This enables support for exposing RAM via DFU.
1474 Note: DFU spec refer to non-volatile memory usage, but
1475 allow usages beyond the scope of spec - here RAM usage,
1476 one that would help mostly the developer.
1478 CONFIG_SYS_DFU_DATA_BUF_SIZE
1479 Dfu transfer uses a buffer before writing data to the
1480 raw storage device. Make the size (in bytes) of this buffer
1481 configurable. The size of this buffer is also configurable
1482 through the "dfu_bufsiz" environment variable.
1484 CONFIG_SYS_DFU_MAX_FILE_SIZE
1485 When updating files rather than the raw storage device,
1486 we use a static buffer to copy the file into and then write
1487 the buffer once we've been given the whole file. Define
1488 this to the maximum filesize (in bytes) for the buffer.
1489 Default is 4 MiB if undefined.
1491 - Journaling Flash filesystem support:
1492 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1493 CONFIG_JFFS2_NAND_DEV
1494 Define these for a default partition on a NAND device
1496 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1497 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1498 Define these for a default partition on a NOR device
1500 CONFIG_SYS_JFFS_CUSTOM_PART
1501 Define this to create an own partition. You have to provide a
1502 function struct part_info* jffs2_part_info(int part_num)
1504 If you define only one JFFS2 partition you may also want to
1505 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1506 to disable the command chpart. This is the default when you
1507 have not defined a custom partition
1509 - FAT(File Allocation Table) filesystem write function support:
1512 Define this to enable support for saving memory data as a
1513 file in FAT formatted partition.
1515 This will also enable the command "fatwrite" enabling the
1516 user to write files to FAT.
1518 CBFS (Coreboot Filesystem) support
1521 Define this to enable support for reading from a Coreboot
1522 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1528 Define this to enable standard (PC-Style) keyboard
1532 Standard PC keyboard driver with US (is default) and
1533 GERMAN key layout (switch via environment 'keymap=de') support.
1534 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1535 for cfb_console. Supports cursor blinking.
1538 Enables a Chrome OS keyboard using the CROS_EC interface.
1539 This uses CROS_EC to communicate with a second microcontroller
1540 which provides key scans on request.
1545 Define this to enable video support (for output to
1548 CONFIG_VIDEO_CT69000
1550 Enable Chips & Technologies 69000 Video chip
1552 CONFIG_VIDEO_SMI_LYNXEM
1553 Enable Silicon Motion SMI 712/710/810 Video chip. The
1554 video output is selected via environment 'videoout'
1555 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1558 For the CT69000 and SMI_LYNXEM drivers, videomode is
1559 selected via environment 'videomode'. Two different ways
1561 - "videomode=num" 'num' is a standard LiLo mode numbers.
1562 Following standard modes are supported (* is default):
1564 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1565 -------------+---------------------------------------------
1566 8 bits | 0x301* 0x303 0x305 0x161 0x307
1567 15 bits | 0x310 0x313 0x316 0x162 0x319
1568 16 bits | 0x311 0x314 0x317 0x163 0x31A
1569 24 bits | 0x312 0x315 0x318 ? 0x31B
1570 -------------+---------------------------------------------
1571 (i.e. setenv videomode 317; saveenv; reset;)
1573 - "videomode=bootargs" all the video parameters are parsed
1574 from the bootargs. (See drivers/video/videomodes.c)
1577 CONFIG_VIDEO_SED13806
1578 Enable Epson SED13806 driver. This driver supports 8bpp
1579 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1580 or CONFIG_VIDEO_SED13806_16BPP
1583 Enable the Freescale DIU video driver. Reference boards for
1584 SOCs that have a DIU should define this macro to enable DIU
1585 support, and should also define these other macros:
1591 CONFIG_VIDEO_SW_CURSOR
1592 CONFIG_VGA_AS_SINGLE_DEVICE
1594 CONFIG_VIDEO_BMP_LOGO
1596 The DIU driver will look for the 'video-mode' environment
1597 variable, and if defined, enable the DIU as a console during
1598 boot. See the documentation file README.video for a
1599 description of this variable.
1603 Enable the VGA video / BIOS for x86. The alternative if you
1604 are using coreboot is to use the coreboot frame buffer
1611 Define this to enable a custom keyboard support.
1612 This simply calls drv_keyboard_init() which must be
1613 defined in your board-specific files.
1614 The only board using this so far is RBC823.
1616 - LCD Support: CONFIG_LCD
1618 Define this to enable LCD support (for output to LCD
1619 display); also select one of the supported displays
1620 by defining one of these:
1624 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1626 CONFIG_NEC_NL6448AC33:
1628 NEC NL6448AC33-18. Active, color, single scan.
1630 CONFIG_NEC_NL6448BC20
1632 NEC NL6448BC20-08. 6.5", 640x480.
1633 Active, color, single scan.
1635 CONFIG_NEC_NL6448BC33_54
1637 NEC NL6448BC33-54. 10.4", 640x480.
1638 Active, color, single scan.
1642 Sharp 320x240. Active, color, single scan.
1643 It isn't 16x9, and I am not sure what it is.
1645 CONFIG_SHARP_LQ64D341
1647 Sharp LQ64D341 display, 640x480.
1648 Active, color, single scan.
1652 HLD1045 display, 640x480.
1653 Active, color, single scan.
1657 Optrex CBL50840-2 NF-FW 99 22 M5
1659 Hitachi LMG6912RPFC-00T
1663 320x240. Black & white.
1665 Normally display is black on white background; define
1666 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1668 CONFIG_LCD_ALIGNMENT
1670 Normally the LCD is page-aligned (tyically 4KB). If this is
1671 defined then the LCD will be aligned to this value instead.
1672 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1673 here, since it is cheaper to change data cache settings on
1674 a per-section basis.
1676 CONFIG_CONSOLE_SCROLL_LINES
1678 When the console need to be scrolled, this is the number of
1679 lines to scroll by. It defaults to 1. Increasing this makes
1680 the console jump but can help speed up operation when scrolling
1685 Support drawing of RLE8-compressed bitmaps on the LCD.
1689 Enables an 'i2c edid' command which can read EDID
1690 information over I2C from an attached LCD display.
1692 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1694 If this option is set, the environment is checked for
1695 a variable "splashimage". If found, the usual display
1696 of logo, copyright and system information on the LCD
1697 is suppressed and the BMP image at the address
1698 specified in "splashimage" is loaded instead. The
1699 console is redirected to the "nulldev", too. This
1700 allows for a "silent" boot where a splash screen is
1701 loaded very quickly after power-on.
1703 CONFIG_SPLASHIMAGE_GUARD
1705 If this option is set, then U-Boot will prevent the environment
1706 variable "splashimage" from being set to a problematic address
1707 (see README.displaying-bmps and README.arm-unaligned-accesses).
1708 This option is useful for targets where, due to alignment
1709 restrictions, an improperly aligned BMP image will cause a data
1710 abort. If you think you will not have problems with unaligned
1711 accesses (for example because your toolchain prevents them)
1712 there is no need to set this option.
1714 CONFIG_SPLASH_SCREEN_ALIGN
1716 If this option is set the splash image can be freely positioned
1717 on the screen. Environment variable "splashpos" specifies the
1718 position as "x,y". If a positive number is given it is used as
1719 number of pixel from left/top. If a negative number is given it
1720 is used as number of pixel from right/bottom. You can also
1721 specify 'm' for centering the image.
1724 setenv splashpos m,m
1725 => image at center of screen
1727 setenv splashpos 30,20
1728 => image at x = 30 and y = 20
1730 setenv splashpos -10,m
1731 => vertically centered image
1732 at x = dspWidth - bmpWidth - 9
1734 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1736 If this option is set, additionally to standard BMP
1737 images, gzipped BMP images can be displayed via the
1738 splashscreen support or the bmp command.
1740 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1742 If this option is set, 8-bit RLE compressed BMP images
1743 can be displayed via the splashscreen support or the
1746 - Do compresssing for memory range:
1749 If this option is set, it would use zlib deflate method
1750 to compress the specified memory at its best effort.
1752 - Compression support:
1755 Enabled by default to support gzip compressed images.
1759 If this option is set, support for bzip2 compressed
1760 images is included. If not, only uncompressed and gzip
1761 compressed images are supported.
1763 NOTE: the bzip2 algorithm requires a lot of RAM, so
1764 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1769 If this option is set, support for lzma compressed
1772 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1773 requires an amount of dynamic memory that is given by the
1776 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1778 Where lc and lp stand for, respectively, Literal context bits
1779 and Literal pos bits.
1781 This value is upper-bounded by 14MB in the worst case. Anyway,
1782 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1783 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1784 a very small buffer.
1786 Use the lzmainfo tool to determinate the lc and lp values and
1787 then calculate the amount of needed dynamic memory (ensuring
1788 the appropriate CONFIG_SYS_MALLOC_LEN value).
1792 If this option is set, support for LZO compressed images
1798 The address of PHY on MII bus.
1800 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1802 The clock frequency of the MII bus
1806 If this option is set, support for speed/duplex
1807 detection of gigabit PHY is included.
1809 CONFIG_PHY_RESET_DELAY
1811 Some PHY like Intel LXT971A need extra delay after
1812 reset before any MII register access is possible.
1813 For such PHY, set this option to the usec delay
1814 required. (minimum 300usec for LXT971A)
1816 CONFIG_PHY_CMD_DELAY (ppc4xx)
1818 Some PHY like Intel LXT971A need extra delay after
1819 command issued before MII status register can be read
1829 Define a default value for Ethernet address to use
1830 for the respective Ethernet interface, in case this
1831 is not determined automatically.
1836 Define a default value for the IP address to use for
1837 the default Ethernet interface, in case this is not
1838 determined through e.g. bootp.
1839 (Environment variable "ipaddr")
1841 - Server IP address:
1844 Defines a default value for the IP address of a TFTP
1845 server to contact when using the "tftboot" command.
1846 (Environment variable "serverip")
1848 CONFIG_KEEP_SERVERADDR
1850 Keeps the server's MAC address, in the env 'serveraddr'
1851 for passing to bootargs (like Linux's netconsole option)
1853 - Gateway IP address:
1856 Defines a default value for the IP address of the
1857 default router where packets to other networks are
1859 (Environment variable "gatewayip")
1864 Defines a default value for the subnet mask (or
1865 routing prefix) which is used to determine if an IP
1866 address belongs to the local subnet or needs to be
1867 forwarded through a router.
1868 (Environment variable "netmask")
1870 - Multicast TFTP Mode:
1873 Defines whether you want to support multicast TFTP as per
1874 rfc-2090; for example to work with atftp. Lets lots of targets
1875 tftp down the same boot image concurrently. Note: the Ethernet
1876 driver in use must provide a function: mcast() to join/leave a
1879 - BOOTP Recovery Mode:
1880 CONFIG_BOOTP_RANDOM_DELAY
1882 If you have many targets in a network that try to
1883 boot using BOOTP, you may want to avoid that all
1884 systems send out BOOTP requests at precisely the same
1885 moment (which would happen for instance at recovery
1886 from a power failure, when all systems will try to
1887 boot, thus flooding the BOOTP server. Defining
1888 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1889 inserted before sending out BOOTP requests. The
1890 following delays are inserted then:
1892 1st BOOTP request: delay 0 ... 1 sec
1893 2nd BOOTP request: delay 0 ... 2 sec
1894 3rd BOOTP request: delay 0 ... 4 sec
1896 BOOTP requests: delay 0 ... 8 sec
1898 - DHCP Advanced Options:
1899 You can fine tune the DHCP functionality by defining
1900 CONFIG_BOOTP_* symbols:
1902 CONFIG_BOOTP_SUBNETMASK
1903 CONFIG_BOOTP_GATEWAY
1904 CONFIG_BOOTP_HOSTNAME
1905 CONFIG_BOOTP_NISDOMAIN
1906 CONFIG_BOOTP_BOOTPATH
1907 CONFIG_BOOTP_BOOTFILESIZE
1910 CONFIG_BOOTP_SEND_HOSTNAME
1911 CONFIG_BOOTP_NTPSERVER
1912 CONFIG_BOOTP_TIMEOFFSET
1913 CONFIG_BOOTP_VENDOREX
1914 CONFIG_BOOTP_MAY_FAIL
1916 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1917 environment variable, not the BOOTP server.
1919 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1920 after the configured retry count, the call will fail
1921 instead of starting over. This can be used to fail over
1922 to Link-local IP address configuration if the DHCP server
1925 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1926 serverip from a DHCP server, it is possible that more
1927 than one DNS serverip is offered to the client.
1928 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1929 serverip will be stored in the additional environment
1930 variable "dnsip2". The first DNS serverip is always
1931 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1934 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1935 to do a dynamic update of a DNS server. To do this, they
1936 need the hostname of the DHCP requester.
1937 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1938 of the "hostname" environment variable is passed as
1939 option 12 to the DHCP server.
1941 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1943 A 32bit value in microseconds for a delay between
1944 receiving a "DHCP Offer" and sending the "DHCP Request".
1945 This fixes a problem with certain DHCP servers that don't
1946 respond 100% of the time to a "DHCP request". E.g. On an
1947 AT91RM9200 processor running at 180MHz, this delay needed
1948 to be *at least* 15,000 usec before a Windows Server 2003
1949 DHCP server would reply 100% of the time. I recommend at
1950 least 50,000 usec to be safe. The alternative is to hope
1951 that one of the retries will be successful but note that
1952 the DHCP timeout and retry process takes a longer than
1955 - Link-local IP address negotiation:
1956 Negotiate with other link-local clients on the local network
1957 for an address that doesn't require explicit configuration.
1958 This is especially useful if a DHCP server cannot be guaranteed
1959 to exist in all environments that the device must operate.
1961 See doc/README.link-local for more information.
1964 CONFIG_CDP_DEVICE_ID
1966 The device id used in CDP trigger frames.
1968 CONFIG_CDP_DEVICE_ID_PREFIX
1970 A two character string which is prefixed to the MAC address
1975 A printf format string which contains the ascii name of
1976 the port. Normally is set to "eth%d" which sets
1977 eth0 for the first Ethernet, eth1 for the second etc.
1979 CONFIG_CDP_CAPABILITIES
1981 A 32bit integer which indicates the device capabilities;
1982 0x00000010 for a normal host which does not forwards.
1986 An ascii string containing the version of the software.
1990 An ascii string containing the name of the platform.
1994 A 32bit integer sent on the trigger.
1996 CONFIG_CDP_POWER_CONSUMPTION
1998 A 16bit integer containing the power consumption of the
1999 device in .1 of milliwatts.
2001 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2003 A byte containing the id of the VLAN.
2005 - Status LED: CONFIG_STATUS_LED
2007 Several configurations allow to display the current
2008 status using a LED. For instance, the LED will blink
2009 fast while running U-Boot code, stop blinking as
2010 soon as a reply to a BOOTP request was received, and
2011 start blinking slow once the Linux kernel is running
2012 (supported by a status LED driver in the Linux
2013 kernel). Defining CONFIG_STATUS_LED enables this
2019 The status LED can be connected to a GPIO pin.
2020 In such cases, the gpio_led driver can be used as a
2021 status LED backend implementation. Define CONFIG_GPIO_LED
2022 to include the gpio_led driver in the U-Boot binary.
2024 CONFIG_GPIO_LED_INVERTED_TABLE
2025 Some GPIO connected LEDs may have inverted polarity in which
2026 case the GPIO high value corresponds to LED off state and
2027 GPIO low value corresponds to LED on state.
2028 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2029 with a list of GPIO LEDs that have inverted polarity.
2031 - CAN Support: CONFIG_CAN_DRIVER
2033 Defining CONFIG_CAN_DRIVER enables CAN driver support
2034 on those systems that support this (optional)
2035 feature, like the TQM8xxL modules.
2037 - I2C Support: CONFIG_SYS_I2C
2039 This enable the NEW i2c subsystem, and will allow you to use
2040 i2c commands at the u-boot command line (as long as you set
2041 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2042 based realtime clock chips or other i2c devices. See
2043 common/cmd_i2c.c for a description of the command line
2046 ported i2c driver to the new framework:
2047 - drivers/i2c/soft_i2c.c:
2048 - activate first bus with CONFIG_SYS_I2C_SOFT define
2049 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2050 for defining speed and slave address
2051 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2052 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2053 for defining speed and slave address
2054 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2055 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2056 for defining speed and slave address
2057 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2058 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2059 for defining speed and slave address
2061 - drivers/i2c/fsl_i2c.c:
2062 - activate i2c driver with CONFIG_SYS_I2C_FSL
2063 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2064 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2065 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2067 - If your board supports a second fsl i2c bus, define
2068 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2069 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2070 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2073 - drivers/i2c/tegra_i2c.c:
2074 - activate this driver with CONFIG_SYS_I2C_TEGRA
2075 - This driver adds 4 i2c buses with a fix speed from
2076 100000 and the slave addr 0!
2078 - drivers/i2c/ppc4xx_i2c.c
2079 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2080 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2081 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2083 - drivers/i2c/i2c_mxc.c
2084 - activate this driver with CONFIG_SYS_I2C_MXC
2085 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2086 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2087 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2088 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2089 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2090 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2091 If thoses defines are not set, default value is 100000
2092 for speed, and 0 for slave.
2094 - drivers/i2c/rcar_i2c.c:
2095 - activate this driver with CONFIG_SYS_I2C_RCAR
2096 - This driver adds 4 i2c buses
2098 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2099 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2100 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2101 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2102 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2103 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2104 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2105 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2106 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2108 - drivers/i2c/sh_i2c.c:
2109 - activate this driver with CONFIG_SYS_I2C_SH
2110 - This driver adds from 2 to 5 i2c buses
2112 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2113 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2114 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2115 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2116 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2117 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2118 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2119 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2120 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2121 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2122 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2123 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2124 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2126 - drivers/i2c/omap24xx_i2c.c
2127 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2128 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2129 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2130 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2131 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2132 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2133 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2134 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2135 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2136 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2137 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2139 - drivers/i2c/zynq_i2c.c
2140 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2141 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2142 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2146 CONFIG_SYS_NUM_I2C_BUSES
2147 Hold the number of i2c busses you want to use. If you
2148 don't use/have i2c muxes on your i2c bus, this
2149 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2152 CONFIG_SYS_I2C_DIRECT_BUS
2153 define this, if you don't use i2c muxes on your hardware.
2154 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2157 CONFIG_SYS_I2C_MAX_HOPS
2158 define how many muxes are maximal consecutively connected
2159 on one i2c bus. If you not use i2c muxes, omit this
2162 CONFIG_SYS_I2C_BUSES
2163 hold a list of busses you want to use, only used if
2164 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2165 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2166 CONFIG_SYS_NUM_I2C_BUSES = 9:
2168 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2169 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2170 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2171 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2172 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2173 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2174 {1, {I2C_NULL_HOP}}, \
2175 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2176 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2180 bus 0 on adapter 0 without a mux
2181 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2182 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2183 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2184 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2185 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2186 bus 6 on adapter 1 without a mux
2187 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2188 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2190 If you do not have i2c muxes on your board, omit this define.
2192 - Legacy I2C Support: CONFIG_HARD_I2C
2194 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2195 provides the following compelling advantages:
2197 - more than one i2c adapter is usable
2198 - approved multibus support
2199 - better i2c mux support
2201 ** Please consider updating your I2C driver now. **
2203 These enable legacy I2C serial bus commands. Defining
2204 CONFIG_HARD_I2C will include the appropriate I2C driver
2205 for the selected CPU.
2207 This will allow you to use i2c commands at the u-boot
2208 command line (as long as you set CONFIG_CMD_I2C in
2209 CONFIG_COMMANDS) and communicate with i2c based realtime
2210 clock chips. See common/cmd_i2c.c for a description of the
2211 command line interface.
2213 CONFIG_HARD_I2C selects a hardware I2C controller.
2215 There are several other quantities that must also be
2216 defined when you define CONFIG_HARD_I2C.
2218 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2219 to be the frequency (in Hz) at which you wish your i2c bus
2220 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2221 the CPU's i2c node address).
2223 Now, the u-boot i2c code for the mpc8xx
2224 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2225 and so its address should therefore be cleared to 0 (See,
2226 eg, MPC823e User's Manual p.16-473). So, set
2227 CONFIG_SYS_I2C_SLAVE to 0.
2229 CONFIG_SYS_I2C_INIT_MPC5XXX
2231 When a board is reset during an i2c bus transfer
2232 chips might think that the current transfer is still
2233 in progress. Reset the slave devices by sending start
2234 commands until the slave device responds.
2236 That's all that's required for CONFIG_HARD_I2C.
2238 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2239 then the following macros need to be defined (examples are
2240 from include/configs/lwmon.h):
2244 (Optional). Any commands necessary to enable the I2C
2245 controller or configure ports.
2247 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2251 (Only for MPC8260 CPU). The I/O port to use (the code
2252 assumes both bits are on the same port). Valid values
2253 are 0..3 for ports A..D.
2257 The code necessary to make the I2C data line active
2258 (driven). If the data line is open collector, this
2261 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2265 The code necessary to make the I2C data line tri-stated
2266 (inactive). If the data line is open collector, this
2269 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2273 Code that returns true if the I2C data line is high,
2276 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2280 If <bit> is true, sets the I2C data line high. If it
2281 is false, it clears it (low).
2283 eg: #define I2C_SDA(bit) \
2284 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2285 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2289 If <bit> is true, sets the I2C clock line high. If it
2290 is false, it clears it (low).
2292 eg: #define I2C_SCL(bit) \
2293 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2294 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2298 This delay is invoked four times per clock cycle so this
2299 controls the rate of data transfer. The data rate thus
2300 is 1 / (I2C_DELAY * 4). Often defined to be something
2303 #define I2C_DELAY udelay(2)
2305 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2307 If your arch supports the generic GPIO framework (asm/gpio.h),
2308 then you may alternatively define the two GPIOs that are to be
2309 used as SCL / SDA. Any of the previous I2C_xxx macros will
2310 have GPIO-based defaults assigned to them as appropriate.
2312 You should define these to the GPIO value as given directly to
2313 the generic GPIO functions.
2315 CONFIG_SYS_I2C_INIT_BOARD
2317 When a board is reset during an i2c bus transfer
2318 chips might think that the current transfer is still
2319 in progress. On some boards it is possible to access
2320 the i2c SCLK line directly, either by using the
2321 processor pin as a GPIO or by having a second pin
2322 connected to the bus. If this option is defined a
2323 custom i2c_init_board() routine in boards/xxx/board.c
2324 is run early in the boot sequence.
2326 CONFIG_SYS_I2C_BOARD_LATE_INIT
2328 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2329 defined a custom i2c_board_late_init() routine in
2330 boards/xxx/board.c is run AFTER the operations in i2c_init()
2331 is completed. This callpoint can be used to unreset i2c bus
2332 using CPU i2c controller register accesses for CPUs whose i2c
2333 controller provide such a method. It is called at the end of
2334 i2c_init() to allow i2c_init operations to setup the i2c bus
2335 controller on the CPU (e.g. setting bus speed & slave address).
2337 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2339 This option enables configuration of bi_iic_fast[] flags
2340 in u-boot bd_info structure based on u-boot environment
2341 variable "i2cfast". (see also i2cfast)
2343 CONFIG_I2C_MULTI_BUS
2345 This option allows the use of multiple I2C buses, each of which
2346 must have a controller. At any point in time, only one bus is
2347 active. To switch to a different bus, use the 'i2c dev' command.
2348 Note that bus numbering is zero-based.
2350 CONFIG_SYS_I2C_NOPROBES
2352 This option specifies a list of I2C devices that will be skipped
2353 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2354 is set, specify a list of bus-device pairs. Otherwise, specify
2355 a 1D array of device addresses
2358 #undef CONFIG_I2C_MULTI_BUS
2359 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2361 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2363 #define CONFIG_I2C_MULTI_BUS
2364 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2366 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2368 CONFIG_SYS_SPD_BUS_NUM
2370 If defined, then this indicates the I2C bus number for DDR SPD.
2371 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2373 CONFIG_SYS_RTC_BUS_NUM
2375 If defined, then this indicates the I2C bus number for the RTC.
2376 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2378 CONFIG_SYS_DTT_BUS_NUM
2380 If defined, then this indicates the I2C bus number for the DTT.
2381 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2383 CONFIG_SYS_I2C_DTT_ADDR:
2385 If defined, specifies the I2C address of the DTT device.
2386 If not defined, then U-Boot uses predefined value for
2387 specified DTT device.
2389 CONFIG_SOFT_I2C_READ_REPEATED_START
2391 defining this will force the i2c_read() function in
2392 the soft_i2c driver to perform an I2C repeated start
2393 between writing the address pointer and reading the
2394 data. If this define is omitted the default behaviour
2395 of doing a stop-start sequence will be used. Most I2C
2396 devices can use either method, but some require one or
2399 - SPI Support: CONFIG_SPI
2401 Enables SPI driver (so far only tested with
2402 SPI EEPROM, also an instance works with Crystal A/D and
2403 D/As on the SACSng board)
2407 Enables the driver for SPI controller on SuperH. Currently
2408 only SH7757 is supported.
2412 Enables extended (16-bit) SPI EEPROM addressing.
2413 (symmetrical to CONFIG_I2C_X)
2417 Enables a software (bit-bang) SPI driver rather than
2418 using hardware support. This is a general purpose
2419 driver that only requires three general I/O port pins
2420 (two outputs, one input) to function. If this is
2421 defined, the board configuration must define several
2422 SPI configuration items (port pins to use, etc). For
2423 an example, see include/configs/sacsng.h.
2427 Enables a hardware SPI driver for general-purpose reads
2428 and writes. As with CONFIG_SOFT_SPI, the board configuration
2429 must define a list of chip-select function pointers.
2430 Currently supported on some MPC8xxx processors. For an
2431 example, see include/configs/mpc8349emds.h.
2435 Enables the driver for the SPI controllers on i.MX and MXC
2436 SoCs. Currently i.MX31/35/51 are supported.
2438 - FPGA Support: CONFIG_FPGA
2440 Enables FPGA subsystem.
2442 CONFIG_FPGA_<vendor>
2444 Enables support for specific chip vendors.
2447 CONFIG_FPGA_<family>
2449 Enables support for FPGA family.
2450 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2454 Specify the number of FPGA devices to support.
2456 CONFIG_SYS_FPGA_PROG_FEEDBACK
2458 Enable printing of hash marks during FPGA configuration.
2460 CONFIG_SYS_FPGA_CHECK_BUSY
2462 Enable checks on FPGA configuration interface busy
2463 status by the configuration function. This option
2464 will require a board or device specific function to
2469 If defined, a function that provides delays in the FPGA
2470 configuration driver.
2472 CONFIG_SYS_FPGA_CHECK_CTRLC
2473 Allow Control-C to interrupt FPGA configuration
2475 CONFIG_SYS_FPGA_CHECK_ERROR
2477 Check for configuration errors during FPGA bitfile
2478 loading. For example, abort during Virtex II
2479 configuration if the INIT_B line goes low (which
2480 indicated a CRC error).
2482 CONFIG_SYS_FPGA_WAIT_INIT
2484 Maximum time to wait for the INIT_B line to deassert
2485 after PROB_B has been deasserted during a Virtex II
2486 FPGA configuration sequence. The default time is 500
2489 CONFIG_SYS_FPGA_WAIT_BUSY
2491 Maximum time to wait for BUSY to deassert during
2492 Virtex II FPGA configuration. The default is 5 ms.
2494 CONFIG_SYS_FPGA_WAIT_CONFIG
2496 Time to wait after FPGA configuration. The default is
2499 - Configuration Management:
2502 If defined, this string will be added to the U-Boot
2503 version information (U_BOOT_VERSION)
2505 - Vendor Parameter Protection:
2507 U-Boot considers the values of the environment
2508 variables "serial#" (Board Serial Number) and
2509 "ethaddr" (Ethernet Address) to be parameters that
2510 are set once by the board vendor / manufacturer, and
2511 protects these variables from casual modification by
2512 the user. Once set, these variables are read-only,
2513 and write or delete attempts are rejected. You can
2514 change this behaviour:
2516 If CONFIG_ENV_OVERWRITE is #defined in your config
2517 file, the write protection for vendor parameters is
2518 completely disabled. Anybody can change or delete
2521 Alternatively, if you #define _both_ CONFIG_ETHADDR
2522 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2523 Ethernet address is installed in the environment,
2524 which can be changed exactly ONCE by the user. [The
2525 serial# is unaffected by this, i. e. it remains
2528 The same can be accomplished in a more flexible way
2529 for any variable by configuring the type of access
2530 to allow for those variables in the ".flags" variable
2531 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2536 Define this variable to enable the reservation of
2537 "protected RAM", i. e. RAM which is not overwritten
2538 by U-Boot. Define CONFIG_PRAM to hold the number of
2539 kB you want to reserve for pRAM. You can overwrite
2540 this default value by defining an environment
2541 variable "pram" to the number of kB you want to
2542 reserve. Note that the board info structure will
2543 still show the full amount of RAM. If pRAM is
2544 reserved, a new environment variable "mem" will
2545 automatically be defined to hold the amount of
2546 remaining RAM in a form that can be passed as boot
2547 argument to Linux, for instance like that:
2549 setenv bootargs ... mem=\${mem}
2552 This way you can tell Linux not to use this memory,
2553 either, which results in a memory region that will
2554 not be affected by reboots.
2556 *WARNING* If your board configuration uses automatic
2557 detection of the RAM size, you must make sure that
2558 this memory test is non-destructive. So far, the
2559 following board configurations are known to be
2562 IVMS8, IVML24, SPD8xx, TQM8xxL,
2563 HERMES, IP860, RPXlite, LWMON,
2566 - Access to physical memory region (> 4GB)
2567 Some basic support is provided for operations on memory not
2568 normally accessible to U-Boot - e.g. some architectures
2569 support access to more than 4GB of memory on 32-bit
2570 machines using physical address extension or similar.
2571 Define CONFIG_PHYSMEM to access this basic support, which
2572 currently only supports clearing the memory.
2577 Define this variable to stop the system in case of a
2578 fatal error, so that you have to reset it manually.
2579 This is probably NOT a good idea for an embedded
2580 system where you want the system to reboot
2581 automatically as fast as possible, but it may be
2582 useful during development since you can try to debug
2583 the conditions that lead to the situation.
2585 CONFIG_NET_RETRY_COUNT
2587 This variable defines the number of retries for
2588 network operations like ARP, RARP, TFTP, or BOOTP
2589 before giving up the operation. If not defined, a
2590 default value of 5 is used.
2594 Timeout waiting for an ARP reply in milliseconds.
2598 Timeout in milliseconds used in NFS protocol.
2599 If you encounter "ERROR: Cannot umount" in nfs command,
2600 try longer timeout such as
2601 #define CONFIG_NFS_TIMEOUT 10000UL
2603 - Command Interpreter:
2604 CONFIG_AUTO_COMPLETE
2606 Enable auto completion of commands using TAB.
2608 Note that this feature has NOT been implemented yet
2609 for the "hush" shell.
2612 CONFIG_SYS_HUSH_PARSER
2614 Define this variable to enable the "hush" shell (from
2615 Busybox) as command line interpreter, thus enabling
2616 powerful command line syntax like
2617 if...then...else...fi conditionals or `&&' and '||'
2618 constructs ("shell scripts").
2620 If undefined, you get the old, much simpler behaviour
2621 with a somewhat smaller memory footprint.
2624 CONFIG_SYS_PROMPT_HUSH_PS2
2626 This defines the secondary prompt string, which is
2627 printed when the command interpreter needs more input
2628 to complete a command. Usually "> ".
2632 In the current implementation, the local variables
2633 space and global environment variables space are
2634 separated. Local variables are those you define by
2635 simply typing `name=value'. To access a local
2636 variable later on, you have write `$name' or
2637 `${name}'; to execute the contents of a variable
2638 directly type `$name' at the command prompt.
2640 Global environment variables are those you use
2641 setenv/printenv to work with. To run a command stored
2642 in such a variable, you need to use the run command,
2643 and you must not use the '$' sign to access them.
2645 To store commands and special characters in a
2646 variable, please use double quotation marks
2647 surrounding the whole text of the variable, instead
2648 of the backslashes before semicolons and special
2651 - Commandline Editing and History:
2652 CONFIG_CMDLINE_EDITING
2654 Enable editing and History functions for interactive
2655 commandline input operations
2657 - Default Environment:
2658 CONFIG_EXTRA_ENV_SETTINGS
2660 Define this to contain any number of null terminated
2661 strings (variable = value pairs) that will be part of
2662 the default environment compiled into the boot image.
2664 For example, place something like this in your
2665 board's config file:
2667 #define CONFIG_EXTRA_ENV_SETTINGS \
2671 Warning: This method is based on knowledge about the
2672 internal format how the environment is stored by the
2673 U-Boot code. This is NOT an official, exported
2674 interface! Although it is unlikely that this format
2675 will change soon, there is no guarantee either.
2676 You better know what you are doing here.
2678 Note: overly (ab)use of the default environment is
2679 discouraged. Make sure to check other ways to preset
2680 the environment like the "source" command or the
2683 CONFIG_ENV_VARS_UBOOT_CONFIG
2685 Define this in order to add variables describing the
2686 U-Boot build configuration to the default environment.
2687 These will be named arch, cpu, board, vendor, and soc.
2689 Enabling this option will cause the following to be defined:
2697 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2699 Define this in order to add variables describing certain
2700 run-time determined information about the hardware to the
2701 environment. These will be named board_name, board_rev.
2703 CONFIG_DELAY_ENVIRONMENT
2705 Normally the environment is loaded when the board is
2706 intialised so that it is available to U-Boot. This inhibits
2707 that so that the environment is not available until
2708 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2709 this is instead controlled by the value of
2710 /config/load-environment.
2712 - DataFlash Support:
2713 CONFIG_HAS_DATAFLASH
2715 Defining this option enables DataFlash features and
2716 allows to read/write in Dataflash via the standard
2719 - Serial Flash support
2722 Defining this option enables SPI flash commands
2723 'sf probe/read/write/erase/update'.
2725 Usage requires an initial 'probe' to define the serial
2726 flash parameters, followed by read/write/erase/update
2729 The following defaults may be provided by the platform
2730 to handle the common case when only a single serial
2731 flash is present on the system.
2733 CONFIG_SF_DEFAULT_BUS Bus identifier
2734 CONFIG_SF_DEFAULT_CS Chip-select
2735 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2736 CONFIG_SF_DEFAULT_SPEED in Hz
2740 Define this option to include a destructive SPI flash
2743 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2745 Define this option to use the Bank addr/Extended addr
2746 support on SPI flashes which has size > 16Mbytes.
2748 - SystemACE Support:
2751 Adding this option adds support for Xilinx SystemACE
2752 chips attached via some sort of local bus. The address
2753 of the chip must also be defined in the
2754 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2756 #define CONFIG_SYSTEMACE
2757 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2759 When SystemACE support is added, the "ace" device type
2760 becomes available to the fat commands, i.e. fatls.
2762 - TFTP Fixed UDP Port:
2765 If this is defined, the environment variable tftpsrcp
2766 is used to supply the TFTP UDP source port value.
2767 If tftpsrcp isn't defined, the normal pseudo-random port
2768 number generator is used.
2770 Also, the environment variable tftpdstp is used to supply
2771 the TFTP UDP destination port value. If tftpdstp isn't
2772 defined, the normal port 69 is used.
2774 The purpose for tftpsrcp is to allow a TFTP server to
2775 blindly start the TFTP transfer using the pre-configured
2776 target IP address and UDP port. This has the effect of
2777 "punching through" the (Windows XP) firewall, allowing
2778 the remainder of the TFTP transfer to proceed normally.
2779 A better solution is to properly configure the firewall,
2780 but sometimes that is not allowed.
2785 This enables a generic 'hash' command which can produce
2786 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2790 Enable the hash verify command (hash -v). This adds to code
2793 CONFIG_SHA1 - support SHA1 hashing
2794 CONFIG_SHA256 - support SHA256 hashing
2796 Note: There is also a sha1sum command, which should perhaps
2797 be deprecated in favour of 'hash sha1'.
2799 - Freescale i.MX specific commands:
2800 CONFIG_CMD_HDMIDETECT
2801 This enables 'hdmidet' command which returns true if an
2802 HDMI monitor is detected. This command is i.MX 6 specific.
2805 This enables the 'bmode' (bootmode) command for forcing
2806 a boot from specific media.
2808 This is useful for forcing the ROM's usb downloader to
2809 activate upon a watchdog reset which is nice when iterating
2810 on U-Boot. Using the reset button or running bmode normal
2811 will set it back to normal. This command currently
2812 supports i.MX53 and i.MX6.
2817 This enables the RSA algorithm used for FIT image verification
2818 in U-Boot. See doc/uImage/signature for more information.
2820 The signing part is build into mkimage regardless of this
2824 - Show boot progress:
2825 CONFIG_SHOW_BOOT_PROGRESS
2827 Defining this option allows to add some board-
2828 specific code (calling a user-provided function
2829 "show_boot_progress(int)") that enables you to show
2830 the system's boot progress on some display (for
2831 example, some LED's) on your board. At the moment,
2832 the following checkpoints are implemented:
2834 - Detailed boot stage timing
2836 Define this option to get detailed timing of each stage
2837 of the boot process.
2839 CONFIG_BOOTSTAGE_USER_COUNT
2840 This is the number of available user bootstage records.
2841 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2842 a new ID will be allocated from this stash. If you exceed
2843 the limit, recording will stop.
2845 CONFIG_BOOTSTAGE_REPORT
2846 Define this to print a report before boot, similar to this:
2848 Timer summary in microseconds:
2851 3,575,678 3,575,678 board_init_f start
2852 3,575,695 17 arch_cpu_init A9
2853 3,575,777 82 arch_cpu_init done
2854 3,659,598 83,821 board_init_r start
2855 3,910,375 250,777 main_loop
2856 29,916,167 26,005,792 bootm_start
2857 30,361,327 445,160 start_kernel
2859 CONFIG_CMD_BOOTSTAGE
2860 Add a 'bootstage' command which supports printing a report
2861 and un/stashing of bootstage data.
2863 CONFIG_BOOTSTAGE_FDT
2864 Stash the bootstage information in the FDT. A root 'bootstage'
2865 node is created with each bootstage id as a child. Each child
2866 has a 'name' property and either 'mark' containing the
2867 mark time in microsecond, or 'accum' containing the
2868 accumulated time for that bootstage id in microseconds.
2873 name = "board_init_f";
2882 Code in the Linux kernel can find this in /proc/devicetree.
2884 Legacy uImage format:
2887 1 common/cmd_bootm.c before attempting to boot an image
2888 -1 common/cmd_bootm.c Image header has bad magic number
2889 2 common/cmd_bootm.c Image header has correct magic number
2890 -2 common/cmd_bootm.c Image header has bad checksum
2891 3 common/cmd_bootm.c Image header has correct checksum
2892 -3 common/cmd_bootm.c Image data has bad checksum
2893 4 common/cmd_bootm.c Image data has correct checksum
2894 -4 common/cmd_bootm.c Image is for unsupported architecture
2895 5 common/cmd_bootm.c Architecture check OK
2896 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2897 6 common/cmd_bootm.c Image Type check OK
2898 -6 common/cmd_bootm.c gunzip uncompression error
2899 -7 common/cmd_bootm.c Unimplemented compression type
2900 7 common/cmd_bootm.c Uncompression OK
2901 8 common/cmd_bootm.c No uncompress/copy overwrite error
2902 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2904 9 common/image.c Start initial ramdisk verification
2905 -10 common/image.c Ramdisk header has bad magic number
2906 -11 common/image.c Ramdisk header has bad checksum
2907 10 common/image.c Ramdisk header is OK
2908 -12 common/image.c Ramdisk data has bad checksum
2909 11 common/image.c Ramdisk data has correct checksum
2910 12 common/image.c Ramdisk verification complete, start loading
2911 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2912 13 common/image.c Start multifile image verification
2913 14 common/image.c No initial ramdisk, no multifile, continue.
2915 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2917 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2918 -31 post/post.c POST test failed, detected by post_output_backlog()
2919 -32 post/post.c POST test failed, detected by post_run_single()
2921 34 common/cmd_doc.c before loading a Image from a DOC device
2922 -35 common/cmd_doc.c Bad usage of "doc" command
2923 35 common/cmd_doc.c correct usage of "doc" command
2924 -36 common/cmd_doc.c No boot device
2925 36 common/cmd_doc.c correct boot device
2926 -37 common/cmd_doc.c Unknown Chip ID on boot device
2927 37 common/cmd_doc.c correct chip ID found, device available
2928 -38 common/cmd_doc.c Read Error on boot device
2929 38 common/cmd_doc.c reading Image header from DOC device OK
2930 -39 common/cmd_doc.c Image header has bad magic number
2931 39 common/cmd_doc.c Image header has correct magic number
2932 -40 common/cmd_doc.c Error reading Image from DOC device
2933 40 common/cmd_doc.c Image header has correct magic number
2934 41 common/cmd_ide.c before loading a Image from a IDE device
2935 -42 common/cmd_ide.c Bad usage of "ide" command
2936 42 common/cmd_ide.c correct usage of "ide" command
2937 -43 common/cmd_ide.c No boot device
2938 43 common/cmd_ide.c boot device found
2939 -44 common/cmd_ide.c Device not available
2940 44 common/cmd_ide.c Device available
2941 -45 common/cmd_ide.c wrong partition selected
2942 45 common/cmd_ide.c partition selected
2943 -46 common/cmd_ide.c Unknown partition table
2944 46 common/cmd_ide.c valid partition table found
2945 -47 common/cmd_ide.c Invalid partition type
2946 47 common/cmd_ide.c correct partition type
2947 -48 common/cmd_ide.c Error reading Image Header on boot device
2948 48 common/cmd_ide.c reading Image Header from IDE device OK
2949 -49 common/cmd_ide.c Image header has bad magic number
2950 49 common/cmd_ide.c Image header has correct magic number
2951 -50 common/cmd_ide.c Image header has bad checksum
2952 50 common/cmd_ide.c Image header has correct checksum
2953 -51 common/cmd_ide.c Error reading Image from IDE device
2954 51 common/cmd_ide.c reading Image from IDE device OK
2955 52 common/cmd_nand.c before loading a Image from a NAND device
2956 -53 common/cmd_nand.c Bad usage of "nand" command
2957 53 common/cmd_nand.c correct usage of "nand" command
2958 -54 common/cmd_nand.c No boot device
2959 54 common/cmd_nand.c boot device found
2960 -55 common/cmd_nand.c Unknown Chip ID on boot device
2961 55 common/cmd_nand.c correct chip ID found, device available
2962 -56 common/cmd_nand.c Error reading Image Header on boot device
2963 56 common/cmd_nand.c reading Image Header from NAND device OK
2964 -57 common/cmd_nand.c Image header has bad magic number
2965 57 common/cmd_nand.c Image header has correct magic number
2966 -58 common/cmd_nand.c Error reading Image from NAND device
2967 58 common/cmd_nand.c reading Image from NAND device OK
2969 -60 common/env_common.c Environment has a bad CRC, using default
2971 64 net/eth.c starting with Ethernet configuration.
2972 -64 net/eth.c no Ethernet found.
2973 65 net/eth.c Ethernet found.
2975 -80 common/cmd_net.c usage wrong
2976 80 common/cmd_net.c before calling NetLoop()
2977 -81 common/cmd_net.c some error in NetLoop() occurred
2978 81 common/cmd_net.c NetLoop() back without error
2979 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2980 82 common/cmd_net.c trying automatic boot
2981 83 common/cmd_net.c running "source" command
2982 -83 common/cmd_net.c some error in automatic boot or "source" command
2983 84 common/cmd_net.c end without errors
2988 100 common/cmd_bootm.c Kernel FIT Image has correct format
2989 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2990 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2991 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2992 102 common/cmd_bootm.c Kernel unit name specified
2993 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2994 103 common/cmd_bootm.c Found configuration node
2995 104 common/cmd_bootm.c Got kernel subimage node offset
2996 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2997 105 common/cmd_bootm.c Kernel subimage hash verification OK
2998 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2999 106 common/cmd_bootm.c Architecture check OK
3000 -106 common/cmd_bootm.c Kernel subimage has wrong type
3001 107 common/cmd_bootm.c Kernel subimage type OK
3002 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3003 108 common/cmd_bootm.c Got kernel subimage data/size
3004 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3005 -109 common/cmd_bootm.c Can't get kernel subimage type
3006 -110 common/cmd_bootm.c Can't get kernel subimage comp
3007 -111 common/cmd_bootm.c Can't get kernel subimage os
3008 -112 common/cmd_bootm.c Can't get kernel subimage load address
3009 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3011 120 common/image.c Start initial ramdisk verification
3012 -120 common/image.c Ramdisk FIT image has incorrect format
3013 121 common/image.c Ramdisk FIT image has correct format
3014 122 common/image.c No ramdisk subimage unit name, using configuration
3015 -122 common/image.c Can't get configuration for ramdisk subimage
3016 123 common/image.c Ramdisk unit name specified
3017 -124 common/image.c Can't get ramdisk subimage node offset
3018 125 common/image.c Got ramdisk subimage node offset
3019 -125 common/image.c Ramdisk subimage hash verification failed
3020 126 common/image.c Ramdisk subimage hash verification OK
3021 -126 common/image.c Ramdisk subimage for unsupported architecture
3022 127 common/image.c Architecture check OK
3023 -127 common/image.c Can't get ramdisk subimage data/size
3024 128 common/image.c Got ramdisk subimage data/size
3025 129 common/image.c Can't get ramdisk load address
3026 -129 common/image.c Got ramdisk load address
3028 -130 common/cmd_doc.c Incorrect FIT image format
3029 131 common/cmd_doc.c FIT image format OK
3031 -140 common/cmd_ide.c Incorrect FIT image format
3032 141 common/cmd_ide.c FIT image format OK
3034 -150 common/cmd_nand.c Incorrect FIT image format
3035 151 common/cmd_nand.c FIT image format OK
3037 - FIT image support:
3039 Enable support for the FIT uImage format.
3041 CONFIG_FIT_BEST_MATCH
3042 When no configuration is explicitly selected, default to the
3043 one whose fdt's compatibility field best matches that of
3044 U-Boot itself. A match is considered "best" if it matches the
3045 most specific compatibility entry of U-Boot's fdt's root node.
3046 The order of entries in the configuration's fdt is ignored.
3048 CONFIG_FIT_SIGNATURE
3049 This option enables signature verification of FIT uImages,
3050 using a hash signed and verified using RSA. See
3051 doc/uImage.FIT/signature.txt for more details.
3053 - Standalone program support:
3054 CONFIG_STANDALONE_LOAD_ADDR
3056 This option defines a board specific value for the
3057 address where standalone program gets loaded, thus
3058 overwriting the architecture dependent default
3061 - Frame Buffer Address:
3064 Define CONFIG_FB_ADDR if you want to use specific
3065 address for frame buffer. This is typically the case
3066 when using a graphics controller has separate video
3067 memory. U-Boot will then place the frame buffer at
3068 the given address instead of dynamically reserving it
3069 in system RAM by calling lcd_setmem(), which grabs
3070 the memory for the frame buffer depending on the
3071 configured panel size.
3073 Please see board_init_f function.
3075 - Automatic software updates via TFTP server
3077 CONFIG_UPDATE_TFTP_CNT_MAX
3078 CONFIG_UPDATE_TFTP_MSEC_MAX
3080 These options enable and control the auto-update feature;
3081 for a more detailed description refer to doc/README.update.
3083 - MTD Support (mtdparts command, UBI support)
3086 Adds the MTD device infrastructure from the Linux kernel.
3087 Needed for mtdparts command support.
3089 CONFIG_MTD_PARTITIONS
3091 Adds the MTD partitioning infrastructure from the Linux
3092 kernel. Needed for UBI support.
3097 Adds commands for interacting with MTD partitions formatted
3098 with the UBI flash translation layer
3100 Requires also defining CONFIG_RBTREE
3102 CONFIG_UBI_SILENCE_MSG
3104 Make the verbose messages from UBI stop printing. This leaves
3105 warnings and errors enabled.
3110 Adds commands for interacting with UBI volumes formatted as
3111 UBIFS. UBIFS is read-only in u-boot.
3113 Requires UBI support as well as CONFIG_LZO
3115 CONFIG_UBIFS_SILENCE_MSG
3117 Make the verbose messages from UBIFS stop printing. This leaves
3118 warnings and errors enabled.
3122 Enable building of SPL globally.
3125 LDSCRIPT for linking the SPL binary.
3127 CONFIG_SPL_MAX_FOOTPRINT
3128 Maximum size in memory allocated to the SPL, BSS included.
3129 When defined, the linker checks that the actual memory
3130 used by SPL from _start to __bss_end does not exceed it.
3131 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3132 must not be both defined at the same time.
3135 Maximum size of the SPL image (text, data, rodata, and
3136 linker lists sections), BSS excluded.
3137 When defined, the linker checks that the actual size does
3140 CONFIG_SPL_TEXT_BASE
3141 TEXT_BASE for linking the SPL binary.
3143 CONFIG_SPL_RELOC_TEXT_BASE
3144 Address to relocate to. If unspecified, this is equal to
3145 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3147 CONFIG_SPL_BSS_START_ADDR
3148 Link address for the BSS within the SPL binary.
3150 CONFIG_SPL_BSS_MAX_SIZE
3151 Maximum size in memory allocated to the SPL BSS.
3152 When defined, the linker checks that the actual memory used
3153 by SPL from __bss_start to __bss_end does not exceed it.
3154 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3155 must not be both defined at the same time.
3158 Adress of the start of the stack SPL will use
3160 CONFIG_SPL_RELOC_STACK
3161 Adress of the start of the stack SPL will use after
3162 relocation. If unspecified, this is equal to
3165 CONFIG_SYS_SPL_MALLOC_START
3166 Starting address of the malloc pool used in SPL.
3168 CONFIG_SYS_SPL_MALLOC_SIZE
3169 The size of the malloc pool used in SPL.
3171 CONFIG_SPL_FRAMEWORK
3172 Enable the SPL framework under common/. This framework
3173 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3174 NAND loading of the Linux Kernel.
3176 CONFIG_SPL_DISPLAY_PRINT
3177 For ARM, enable an optional function to print more information
3178 about the running system.
3180 CONFIG_SPL_INIT_MINIMAL
3181 Arch init code should be built for a very small image
3183 CONFIG_SPL_LIBCOMMON_SUPPORT
3184 Support for common/libcommon.o in SPL binary
3186 CONFIG_SPL_LIBDISK_SUPPORT
3187 Support for disk/libdisk.o in SPL binary
3189 CONFIG_SPL_I2C_SUPPORT
3190 Support for drivers/i2c/libi2c.o in SPL binary
3192 CONFIG_SPL_GPIO_SUPPORT
3193 Support for drivers/gpio/libgpio.o in SPL binary
3195 CONFIG_SPL_MMC_SUPPORT
3196 Support for drivers/mmc/libmmc.o in SPL binary
3198 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3199 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3200 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3201 Address, size and partition on the MMC to load U-Boot from
3202 when the MMC is being used in raw mode.
3204 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3205 Sector to load kernel uImage from when MMC is being
3206 used in raw mode (for Falcon mode)
3208 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3209 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3210 Sector and number of sectors to load kernel argument
3211 parameters from when MMC is being used in raw mode
3214 CONFIG_SPL_FAT_SUPPORT
3215 Support for fs/fat/libfat.o in SPL binary
3217 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3218 Filename to read to load U-Boot when reading from FAT
3220 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3221 Filename to read to load kernel uImage when reading
3222 from FAT (for Falcon mode)
3224 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3225 Filename to read to load kernel argument parameters
3226 when reading from FAT (for Falcon mode)
3228 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3229 Set this for NAND SPL on PPC mpc83xx targets, so that
3230 start.S waits for the rest of the SPL to load before
3231 continuing (the hardware starts execution after just
3232 loading the first page rather than the full 4K).
3234 CONFIG_SPL_NAND_BASE
3235 Include nand_base.c in the SPL. Requires
3236 CONFIG_SPL_NAND_DRIVERS.
3238 CONFIG_SPL_NAND_DRIVERS
3239 SPL uses normal NAND drivers, not minimal drivers.
3242 Include standard software ECC in the SPL
3244 CONFIG_SPL_NAND_SIMPLE
3245 Support for NAND boot using simple NAND drivers that
3246 expose the cmd_ctrl() interface.
3248 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3249 Set for the SPL on PPC mpc8xxx targets, support for
3250 drivers/ddr/fsl/libddr.o in SPL binary.
3252 CONFIG_SPL_COMMON_INIT_DDR
3253 Set for common ddr init with serial presence detect in
3256 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3257 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3258 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3259 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3260 CONFIG_SYS_NAND_ECCBYTES
3261 Defines the size and behavior of the NAND that SPL uses
3264 CONFIG_SYS_NAND_U_BOOT_OFFS
3265 Location in NAND to read U-Boot from
3267 CONFIG_SYS_NAND_U_BOOT_DST
3268 Location in memory to load U-Boot to
3270 CONFIG_SYS_NAND_U_BOOT_SIZE
3271 Size of image to load
3273 CONFIG_SYS_NAND_U_BOOT_START
3274 Entry point in loaded image to jump to
3276 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3277 Define this if you need to first read the OOB and then the
3278 data. This is used for example on davinci plattforms.
3280 CONFIG_SPL_OMAP3_ID_NAND
3281 Support for an OMAP3-specific set of functions to return the
3282 ID and MFR of the first attached NAND chip, if present.
3284 CONFIG_SPL_SERIAL_SUPPORT
3285 Support for drivers/serial/libserial.o in SPL binary
3287 CONFIG_SPL_SPI_FLASH_SUPPORT
3288 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3290 CONFIG_SPL_SPI_SUPPORT
3291 Support for drivers/spi/libspi.o in SPL binary
3293 CONFIG_SPL_RAM_DEVICE
3294 Support for running image already present in ram, in SPL binary
3296 CONFIG_SPL_LIBGENERIC_SUPPORT
3297 Support for lib/libgeneric.o in SPL binary
3299 CONFIG_SPL_ENV_SUPPORT
3300 Support for the environment operating in SPL binary
3302 CONFIG_SPL_NET_SUPPORT
3303 Support for the net/libnet.o in SPL binary.
3304 It conflicts with SPL env from storage medium specified by
3305 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3308 Image offset to which the SPL should be padded before appending
3309 the SPL payload. By default, this is defined as
3310 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3311 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3312 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3315 Final target image containing SPL and payload. Some SPLs
3316 use an arch-specific makefile fragment instead, for
3317 example if more than one image needs to be produced.
3319 CONFIG_FIT_SPL_PRINT
3320 Printing information about a FIT image adds quite a bit of
3321 code to SPL. So this is normally disabled in SPL. Use this
3322 option to re-enable it. This will affect the output of the
3323 bootm command when booting a FIT image.
3327 Enable building of TPL globally.
3330 Image offset to which the TPL should be padded before appending
3331 the TPL payload. By default, this is defined as
3332 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3333 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3334 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3339 [so far only for SMDK2400 boards]
3341 - Modem support enable:
3342 CONFIG_MODEM_SUPPORT
3344 - RTS/CTS Flow control enable:
3347 - Modem debug support:
3348 CONFIG_MODEM_SUPPORT_DEBUG
3350 Enables debugging stuff (char screen[1024], dbg())
3351 for modem support. Useful only with BDI2000.
3353 - Interrupt support (PPC):
3355 There are common interrupt_init() and timer_interrupt()
3356 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3357 for CPU specific initialization. interrupt_init_cpu()
3358 should set decrementer_count to appropriate value. If
3359 CPU resets decrementer automatically after interrupt
3360 (ppc4xx) it should set decrementer_count to zero.
3361 timer_interrupt() calls timer_interrupt_cpu() for CPU
3362 specific handling. If board has watchdog / status_led
3363 / other_activity_monitor it works automatically from
3364 general timer_interrupt().
3368 In the target system modem support is enabled when a
3369 specific key (key combination) is pressed during
3370 power-on. Otherwise U-Boot will boot normally
3371 (autoboot). The key_pressed() function is called from
3372 board_init(). Currently key_pressed() is a dummy
3373 function, returning 1 and thus enabling modem
3376 If there are no modem init strings in the
3377 environment, U-Boot proceed to autoboot; the
3378 previous output (banner, info printfs) will be
3381 See also: doc/README.Modem
3383 Board initialization settings:
3384 ------------------------------
3386 During Initialization u-boot calls a number of board specific functions
3387 to allow the preparation of board specific prerequisites, e.g. pin setup
3388 before drivers are initialized. To enable these callbacks the
3389 following configuration macros have to be defined. Currently this is
3390 architecture specific, so please check arch/your_architecture/lib/board.c
3391 typically in board_init_f() and board_init_r().
3393 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3394 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3395 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3396 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3398 Configuration Settings:
3399 -----------------------
3401 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3402 undefine this when you're short of memory.
3404 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3405 width of the commands listed in the 'help' command output.
3407 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3408 prompt for user input.
3410 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3412 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3414 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3416 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3417 the application (usually a Linux kernel) when it is
3420 - CONFIG_SYS_BAUDRATE_TABLE:
3421 List of legal baudrate settings for this board.
3423 - CONFIG_SYS_CONSOLE_INFO_QUIET
3424 Suppress display of console information at boot.
3426 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3427 If the board specific function
3428 extern int overwrite_console (void);
3429 returns 1, the stdin, stderr and stdout are switched to the
3430 serial port, else the settings in the environment are used.
3432 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3433 Enable the call to overwrite_console().
3435 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3436 Enable overwrite of previous console environment settings.
3438 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3439 Begin and End addresses of the area used by the
3442 - CONFIG_SYS_ALT_MEMTEST:
3443 Enable an alternate, more extensive memory test.
3445 - CONFIG_SYS_MEMTEST_SCRATCH:
3446 Scratch address used by the alternate memory test
3447 You only need to set this if address zero isn't writeable
3449 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3450 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3451 this specified memory area will get subtracted from the top
3452 (end) of RAM and won't get "touched" at all by U-Boot. By
3453 fixing up gd->ram_size the Linux kernel should gets passed
3454 the now "corrected" memory size and won't touch it either.
3455 This should work for arch/ppc and arch/powerpc. Only Linux
3456 board ports in arch/powerpc with bootwrapper support that
3457 recalculate the memory size from the SDRAM controller setup
3458 will have to get fixed in Linux additionally.
3460 This option can be used as a workaround for the 440EPx/GRx
3461 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3464 WARNING: Please make sure that this value is a multiple of
3465 the Linux page size (normally 4k). If this is not the case,
3466 then the end address of the Linux memory will be located at a
3467 non page size aligned address and this could cause major
3470 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3471 Enable temporary baudrate change while serial download
3473 - CONFIG_SYS_SDRAM_BASE:
3474 Physical start address of SDRAM. _Must_ be 0 here.
3476 - CONFIG_SYS_MBIO_BASE:
3477 Physical start address of Motherboard I/O (if using a
3480 - CONFIG_SYS_FLASH_BASE:
3481 Physical start address of Flash memory.
3483 - CONFIG_SYS_MONITOR_BASE:
3484 Physical start address of boot monitor code (set by
3485 make config files to be same as the text base address
3486 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3487 CONFIG_SYS_FLASH_BASE when booting from flash.
3489 - CONFIG_SYS_MONITOR_LEN:
3490 Size of memory reserved for monitor code, used to
3491 determine _at_compile_time_ (!) if the environment is
3492 embedded within the U-Boot image, or in a separate
3495 - CONFIG_SYS_MALLOC_LEN:
3496 Size of DRAM reserved for malloc() use.
3498 - CONFIG_SYS_BOOTM_LEN:
3499 Normally compressed uImages are limited to an
3500 uncompressed size of 8 MBytes. If this is not enough,
3501 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3502 to adjust this setting to your needs.
3504 - CONFIG_SYS_BOOTMAPSZ:
3505 Maximum size of memory mapped by the startup code of
3506 the Linux kernel; all data that must be processed by
3507 the Linux kernel (bd_info, boot arguments, FDT blob if
3508 used) must be put below this limit, unless "bootm_low"
3509 environment variable is defined and non-zero. In such case
3510 all data for the Linux kernel must be between "bootm_low"
3511 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3512 variable "bootm_mapsize" will override the value of
3513 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3514 then the value in "bootm_size" will be used instead.
3516 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3517 Enable initrd_high functionality. If defined then the
3518 initrd_high feature is enabled and the bootm ramdisk subcommand
3521 - CONFIG_SYS_BOOT_GET_CMDLINE:
3522 Enables allocating and saving kernel cmdline in space between
3523 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3525 - CONFIG_SYS_BOOT_GET_KBD:
3526 Enables allocating and saving a kernel copy of the bd_info in
3527 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3529 - CONFIG_SYS_MAX_FLASH_BANKS:
3530 Max number of Flash memory banks
3532 - CONFIG_SYS_MAX_FLASH_SECT:
3533 Max number of sectors on a Flash chip
3535 - CONFIG_SYS_FLASH_ERASE_TOUT:
3536 Timeout for Flash erase operations (in ms)
3538 - CONFIG_SYS_FLASH_WRITE_TOUT:
3539 Timeout for Flash write operations (in ms)
3541 - CONFIG_SYS_FLASH_LOCK_TOUT
3542 Timeout for Flash set sector lock bit operation (in ms)
3544 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3545 Timeout for Flash clear lock bits operation (in ms)
3547 - CONFIG_SYS_FLASH_PROTECTION
3548 If defined, hardware flash sectors protection is used
3549 instead of U-Boot software protection.
3551 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3553 Enable TFTP transfers directly to flash memory;
3554 without this option such a download has to be
3555 performed in two steps: (1) download to RAM, and (2)
3556 copy from RAM to flash.
3558 The two-step approach is usually more reliable, since
3559 you can check if the download worked before you erase
3560 the flash, but in some situations (when system RAM is
3561 too limited to allow for a temporary copy of the
3562 downloaded image) this option may be very useful.
3564 - CONFIG_SYS_FLASH_CFI:
3565 Define if the flash driver uses extra elements in the
3566 common flash structure for storing flash geometry.
3568 - CONFIG_FLASH_CFI_DRIVER
3569 This option also enables the building of the cfi_flash driver
3570 in the drivers directory
3572 - CONFIG_FLASH_CFI_MTD
3573 This option enables the building of the cfi_mtd driver
3574 in the drivers directory. The driver exports CFI flash
3577 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3578 Use buffered writes to flash.
3580 - CONFIG_FLASH_SPANSION_S29WS_N
3581 s29ws-n MirrorBit flash has non-standard addresses for buffered
3584 - CONFIG_SYS_FLASH_QUIET_TEST
3585 If this option is defined, the common CFI flash doesn't
3586 print it's warning upon not recognized FLASH banks. This
3587 is useful, if some of the configured banks are only
3588 optionally available.
3590 - CONFIG_FLASH_SHOW_PROGRESS
3591 If defined (must be an integer), print out countdown
3592 digits and dots. Recommended value: 45 (9..1) for 80
3593 column displays, 15 (3..1) for 40 column displays.
3595 - CONFIG_FLASH_VERIFY
3596 If defined, the content of the flash (destination) is compared
3597 against the source after the write operation. An error message
3598 will be printed when the contents are not identical.
3599 Please note that this option is useless in nearly all cases,
3600 since such flash programming errors usually are detected earlier
3601 while unprotecting/erasing/programming. Please only enable
3602 this option if you really know what you are doing.
3604 - CONFIG_SYS_RX_ETH_BUFFER:
3605 Defines the number of Ethernet receive buffers. On some
3606 Ethernet controllers it is recommended to set this value
3607 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3608 buffers can be full shortly after enabling the interface
3609 on high Ethernet traffic.
3610 Defaults to 4 if not defined.
3612 - CONFIG_ENV_MAX_ENTRIES
3614 Maximum number of entries in the hash table that is used
3615 internally to store the environment settings. The default
3616 setting is supposed to be generous and should work in most
3617 cases. This setting can be used to tune behaviour; see
3618 lib/hashtable.c for details.
3620 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3621 - CONFIG_ENV_FLAGS_LIST_STATIC
3622 Enable validation of the values given to environment variables when
3623 calling env set. Variables can be restricted to only decimal,
3624 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3625 the variables can also be restricted to IP address or MAC address.
3627 The format of the list is:
3628 type_attribute = [s|d|x|b|i|m]
3629 access_atribute = [a|r|o|c]
3630 attributes = type_attribute[access_atribute]
3631 entry = variable_name[:attributes]
3634 The type attributes are:
3635 s - String (default)
3638 b - Boolean ([1yYtT|0nNfF])
3642 The access attributes are:
3648 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3649 Define this to a list (string) to define the ".flags"
3650 envirnoment variable in the default or embedded environment.
3652 - CONFIG_ENV_FLAGS_LIST_STATIC
3653 Define this to a list (string) to define validation that
3654 should be done if an entry is not found in the ".flags"
3655 environment variable. To override a setting in the static
3656 list, simply add an entry for the same variable name to the
3659 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3660 If defined, don't allow the -f switch to env set override variable
3663 - CONFIG_SYS_GENERIC_BOARD
3664 This selects the architecture-generic board system instead of the
3665 architecture-specific board files. It is intended to move boards
3666 to this new framework over time. Defining this will disable the
3667 arch/foo/lib/board.c file and use common/board_f.c and
3668 common/board_r.c instead. To use this option your architecture
3669 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3670 its config.mk file). If you find problems enabling this option on
3671 your board please report the problem and send patches!
3673 - CONFIG_SYS_SYM_OFFSETS
3674 This is set by architectures that use offsets for link symbols
3675 instead of absolute values. So bss_start is obtained using an
3676 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3677 directly. You should not need to touch this setting.
3679 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3680 This is set by OMAP boards for the max time that reset should
3681 be asserted. See doc/README.omap-reset-time for details on how
3682 the value can be calulated on a given board.
3684 The following definitions that deal with the placement and management
3685 of environment data (variable area); in general, we support the
3686 following configurations:
3688 - CONFIG_BUILD_ENVCRC:
3690 Builds up envcrc with the target environment so that external utils
3691 may easily extract it and embed it in final U-Boot images.
3693 - CONFIG_ENV_IS_IN_FLASH:
3695 Define this if the environment is in flash memory.
3697 a) The environment occupies one whole flash sector, which is
3698 "embedded" in the text segment with the U-Boot code. This
3699 happens usually with "bottom boot sector" or "top boot
3700 sector" type flash chips, which have several smaller
3701 sectors at the start or the end. For instance, such a
3702 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3703 such a case you would place the environment in one of the
3704 4 kB sectors - with U-Boot code before and after it. With
3705 "top boot sector" type flash chips, you would put the
3706 environment in one of the last sectors, leaving a gap
3707 between U-Boot and the environment.
3709 - CONFIG_ENV_OFFSET:
3711 Offset of environment data (variable area) to the
3712 beginning of flash memory; for instance, with bottom boot
3713 type flash chips the second sector can be used: the offset
3714 for this sector is given here.
3716 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3720 This is just another way to specify the start address of
3721 the flash sector containing the environment (instead of
3724 - CONFIG_ENV_SECT_SIZE:
3726 Size of the sector containing the environment.
3729 b) Sometimes flash chips have few, equal sized, BIG sectors.
3730 In such a case you don't want to spend a whole sector for
3735 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3736 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3737 of this flash sector for the environment. This saves
3738 memory for the RAM copy of the environment.
3740 It may also save flash memory if you decide to use this
3741 when your environment is "embedded" within U-Boot code,
3742 since then the remainder of the flash sector could be used
3743 for U-Boot code. It should be pointed out that this is
3744 STRONGLY DISCOURAGED from a robustness point of view:
3745 updating the environment in flash makes it always
3746 necessary to erase the WHOLE sector. If something goes
3747 wrong before the contents has been restored from a copy in
3748 RAM, your target system will be dead.
3750 - CONFIG_ENV_ADDR_REDUND
3751 CONFIG_ENV_SIZE_REDUND
3753 These settings describe a second storage area used to hold
3754 a redundant copy of the environment data, so that there is
3755 a valid backup copy in case there is a power failure during
3756 a "saveenv" operation.
3758 BE CAREFUL! Any changes to the flash layout, and some changes to the
3759 source code will make it necessary to adapt <board>/u-boot.lds*
3763 - CONFIG_ENV_IS_IN_NVRAM:
3765 Define this if you have some non-volatile memory device
3766 (NVRAM, battery buffered SRAM) which you want to use for the
3772 These two #defines are used to determine the memory area you
3773 want to use for environment. It is assumed that this memory
3774 can just be read and written to, without any special
3777 BE CAREFUL! The first access to the environment happens quite early
3778 in U-Boot initalization (when we try to get the setting of for the
3779 console baudrate). You *MUST* have mapped your NVRAM area then, or
3782 Please note that even with NVRAM we still use a copy of the
3783 environment in RAM: we could work on NVRAM directly, but we want to
3784 keep settings there always unmodified except somebody uses "saveenv"
3785 to save the current settings.
3788 - CONFIG_ENV_IS_IN_EEPROM:
3790 Use this if you have an EEPROM or similar serial access
3791 device and a driver for it.
3793 - CONFIG_ENV_OFFSET:
3796 These two #defines specify the offset and size of the
3797 environment area within the total memory of your EEPROM.
3799 - CONFIG_SYS_I2C_EEPROM_ADDR:
3800 If defined, specified the chip address of the EEPROM device.
3801 The default address is zero.
3803 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3804 If defined, the number of bits used to address bytes in a
3805 single page in the EEPROM device. A 64 byte page, for example
3806 would require six bits.
3808 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3809 If defined, the number of milliseconds to delay between
3810 page writes. The default is zero milliseconds.
3812 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3813 The length in bytes of the EEPROM memory array address. Note
3814 that this is NOT the chip address length!
3816 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3817 EEPROM chips that implement "address overflow" are ones
3818 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3819 address and the extra bits end up in the "chip address" bit
3820 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3823 Note that we consider the length of the address field to
3824 still be one byte because the extra address bits are hidden
3825 in the chip address.
3827 - CONFIG_SYS_EEPROM_SIZE:
3828 The size in bytes of the EEPROM device.
3830 - CONFIG_ENV_EEPROM_IS_ON_I2C
3831 define this, if you have I2C and SPI activated, and your
3832 EEPROM, which holds the environment, is on the I2C bus.
3834 - CONFIG_I2C_ENV_EEPROM_BUS
3835 if you have an Environment on an EEPROM reached over
3836 I2C muxes, you can define here, how to reach this
3837 EEPROM. For example:
3839 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3841 EEPROM which holds the environment, is reached over
3842 a pca9547 i2c mux with address 0x70, channel 3.
3844 - CONFIG_ENV_IS_IN_DATAFLASH:
3846 Define this if you have a DataFlash memory device which you
3847 want to use for the environment.
3849 - CONFIG_ENV_OFFSET:
3853 These three #defines specify the offset and size of the
3854 environment area within the total memory of your DataFlash placed
3855 at the specified address.
3857 - CONFIG_ENV_IS_IN_REMOTE:
3859 Define this if you have a remote memory space which you
3860 want to use for the local device's environment.
3865 These two #defines specify the address and size of the
3866 environment area within the remote memory space. The
3867 local device can get the environment from remote memory
3868 space by SRIO or PCIE links.
3870 BE CAREFUL! For some special cases, the local device can not use
3871 "saveenv" command. For example, the local device will get the
3872 environment stored in a remote NOR flash by SRIO or PCIE link,
3873 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3875 - CONFIG_ENV_IS_IN_NAND:
3877 Define this if you have a NAND device which you want to use
3878 for the environment.
3880 - CONFIG_ENV_OFFSET:
3883 These two #defines specify the offset and size of the environment
3884 area within the first NAND device. CONFIG_ENV_OFFSET must be
3885 aligned to an erase block boundary.
3887 - CONFIG_ENV_OFFSET_REDUND (optional):
3889 This setting describes a second storage area of CONFIG_ENV_SIZE
3890 size used to hold a redundant copy of the environment data, so
3891 that there is a valid backup copy in case there is a power failure
3892 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3893 aligned to an erase block boundary.
3895 - CONFIG_ENV_RANGE (optional):
3897 Specifies the length of the region in which the environment
3898 can be written. This should be a multiple of the NAND device's
3899 block size. Specifying a range with more erase blocks than
3900 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3901 the range to be avoided.
3903 - CONFIG_ENV_OFFSET_OOB (optional):
3905 Enables support for dynamically retrieving the offset of the
3906 environment from block zero's out-of-band data. The
3907 "nand env.oob" command can be used to record this offset.
3908 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3909 using CONFIG_ENV_OFFSET_OOB.
3911 - CONFIG_NAND_ENV_DST
3913 Defines address in RAM to which the nand_spl code should copy the
3914 environment. If redundant environment is used, it will be copied to
3915 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3917 - CONFIG_ENV_IS_IN_UBI:
3919 Define this if you have an UBI volume that you want to use for the
3920 environment. This has the benefit of wear-leveling the environment
3921 accesses, which is important on NAND.
3923 - CONFIG_ENV_UBI_PART:
3925 Define this to a string that is the mtd partition containing the UBI.
3927 - CONFIG_ENV_UBI_VOLUME:
3929 Define this to the name of the volume that you want to store the
3932 - CONFIG_ENV_UBI_VOLUME_REDUND:
3934 Define this to the name of another volume to store a second copy of
3935 the environment in. This will enable redundant environments in UBI.
3936 It is assumed that both volumes are in the same MTD partition.
3938 - CONFIG_UBI_SILENCE_MSG
3939 - CONFIG_UBIFS_SILENCE_MSG
3941 You will probably want to define these to avoid a really noisy system
3942 when storing the env in UBI.
3944 - CONFIG_ENV_IS_IN_MMC:
3946 Define this if you have an MMC device which you want to use for the
3949 - CONFIG_SYS_MMC_ENV_DEV:
3951 Specifies which MMC device the environment is stored in.
3953 - CONFIG_SYS_MMC_ENV_PART (optional):
3955 Specifies which MMC partition the environment is stored in. If not
3956 set, defaults to partition 0, the user area. Common values might be
3957 1 (first MMC boot partition), 2 (second MMC boot partition).
3959 - CONFIG_ENV_OFFSET:
3962 These two #defines specify the offset and size of the environment
3963 area within the specified MMC device.
3965 If offset is positive (the usual case), it is treated as relative to
3966 the start of the MMC partition. If offset is negative, it is treated
3967 as relative to the end of the MMC partition. This can be useful if
3968 your board may be fitted with different MMC devices, which have
3969 different sizes for the MMC partitions, and you always want the
3970 environment placed at the very end of the partition, to leave the
3971 maximum possible space before it, to store other data.
3973 These two values are in units of bytes, but must be aligned to an
3974 MMC sector boundary.
3976 - CONFIG_ENV_OFFSET_REDUND (optional):
3978 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3979 hold a redundant copy of the environment data. This provides a
3980 valid backup copy in case the other copy is corrupted, e.g. due
3981 to a power failure during a "saveenv" operation.
3983 This value may also be positive or negative; this is handled in the
3984 same way as CONFIG_ENV_OFFSET.
3986 This value is also in units of bytes, but must also be aligned to
3987 an MMC sector boundary.
3989 - CONFIG_ENV_SIZE_REDUND (optional):
3991 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3992 set. If this value is set, it must be set to the same value as
3995 - CONFIG_SYS_SPI_INIT_OFFSET
3997 Defines offset to the initial SPI buffer area in DPRAM. The
3998 area is used at an early stage (ROM part) if the environment
3999 is configured to reside in the SPI EEPROM: We need a 520 byte
4000 scratch DPRAM area. It is used between the two initialization
4001 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4002 to be a good choice since it makes it far enough from the
4003 start of the data area as well as from the stack pointer.
4005 Please note that the environment is read-only until the monitor
4006 has been relocated to RAM and a RAM copy of the environment has been
4007 created; also, when using EEPROM you will have to use getenv_f()
4008 until then to read environment variables.
4010 The environment is protected by a CRC32 checksum. Before the monitor
4011 is relocated into RAM, as a result of a bad CRC you will be working
4012 with the compiled-in default environment - *silently*!!! [This is
4013 necessary, because the first environment variable we need is the
4014 "baudrate" setting for the console - if we have a bad CRC, we don't
4015 have any device yet where we could complain.]
4017 Note: once the monitor has been relocated, then it will complain if
4018 the default environment is used; a new CRC is computed as soon as you
4019 use the "saveenv" command to store a valid environment.
4021 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4022 Echo the inverted Ethernet link state to the fault LED.
4024 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4025 also needs to be defined.
4027 - CONFIG_SYS_FAULT_MII_ADDR:
4028 MII address of the PHY to check for the Ethernet link state.
4030 - CONFIG_NS16550_MIN_FUNCTIONS:
4031 Define this if you desire to only have use of the NS16550_init
4032 and NS16550_putc functions for the serial driver located at
4033 drivers/serial/ns16550.c. This option is useful for saving
4034 space for already greatly restricted images, including but not
4035 limited to NAND_SPL configurations.
4037 - CONFIG_DISPLAY_BOARDINFO
4038 Display information about the board that U-Boot is running on
4039 when U-Boot starts up. The board function checkboard() is called
4042 - CONFIG_DISPLAY_BOARDINFO_LATE
4043 Similar to the previous option, but display this information
4044 later, once stdio is running and output goes to the LCD, if
4047 Low Level (hardware related) configuration options:
4048 ---------------------------------------------------
4050 - CONFIG_SYS_CACHELINE_SIZE:
4051 Cache Line Size of the CPU.
4053 - CONFIG_SYS_DEFAULT_IMMR:
4054 Default address of the IMMR after system reset.
4056 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4057 and RPXsuper) to be able to adjust the position of
4058 the IMMR register after a reset.
4060 - CONFIG_SYS_CCSRBAR_DEFAULT:
4061 Default (power-on reset) physical address of CCSR on Freescale
4064 - CONFIG_SYS_CCSRBAR:
4065 Virtual address of CCSR. On a 32-bit build, this is typically
4066 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4068 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4069 for cross-platform code that uses that macro instead.
4071 - CONFIG_SYS_CCSRBAR_PHYS:
4072 Physical address of CCSR. CCSR can be relocated to a new
4073 physical address, if desired. In this case, this macro should
4074 be set to that address. Otherwise, it should be set to the
4075 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4076 is typically relocated on 36-bit builds. It is recommended
4077 that this macro be defined via the _HIGH and _LOW macros:
4079 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4080 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4082 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4083 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4084 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4085 used in assembly code, so it must not contain typecasts or
4086 integer size suffixes (e.g. "ULL").
4088 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4089 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4090 used in assembly code, so it must not contain typecasts or
4091 integer size suffixes (e.g. "ULL").
4093 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4094 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4095 forced to a value that ensures that CCSR is not relocated.
4097 - Floppy Disk Support:
4098 CONFIG_SYS_FDC_DRIVE_NUMBER
4100 the default drive number (default value 0)
4102 CONFIG_SYS_ISA_IO_STRIDE
4104 defines the spacing between FDC chipset registers
4107 CONFIG_SYS_ISA_IO_OFFSET
4109 defines the offset of register from address. It
4110 depends on which part of the data bus is connected to
4111 the FDC chipset. (default value 0)
4113 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4114 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4117 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4118 fdc_hw_init() is called at the beginning of the FDC
4119 setup. fdc_hw_init() must be provided by the board
4120 source code. It is used to make hardware dependant
4124 Most IDE controllers were designed to be connected with PCI
4125 interface. Only few of them were designed for AHB interface.
4126 When software is doing ATA command and data transfer to
4127 IDE devices through IDE-AHB controller, some additional
4128 registers accessing to these kind of IDE-AHB controller
4131 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4132 DO NOT CHANGE unless you know exactly what you're
4133 doing! (11-4) [MPC8xx/82xx systems only]
4135 - CONFIG_SYS_INIT_RAM_ADDR:
4137 Start address of memory area that can be used for
4138 initial data and stack; please note that this must be
4139 writable memory that is working WITHOUT special
4140 initialization, i. e. you CANNOT use normal RAM which
4141 will become available only after programming the
4142 memory controller and running certain initialization
4145 U-Boot uses the following memory types:
4146 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4147 - MPC824X: data cache
4148 - PPC4xx: data cache
4150 - CONFIG_SYS_GBL_DATA_OFFSET:
4152 Offset of the initial data structure in the memory
4153 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4154 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4155 data is located at the end of the available space
4156 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4157 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4158 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4159 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4162 On the MPC824X (or other systems that use the data
4163 cache for initial memory) the address chosen for
4164 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4165 point to an otherwise UNUSED address space between
4166 the top of RAM and the start of the PCI space.
4168 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4170 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4172 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4174 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4176 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4178 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4180 - CONFIG_SYS_OR_TIMING_SDRAM:
4183 - CONFIG_SYS_MAMR_PTA:
4184 periodic timer for refresh
4186 - CONFIG_SYS_DER: Debug Event Register (37-47)
4188 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4189 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4190 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4191 CONFIG_SYS_BR1_PRELIM:
4192 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4194 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4195 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4196 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4197 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4199 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4200 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4201 Machine Mode Register and Memory Periodic Timer
4202 Prescaler definitions (SDRAM timing)
4204 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4205 enable I2C microcode relocation patch (MPC8xx);
4206 define relocation offset in DPRAM [DSP2]
4208 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4209 enable SMC microcode relocation patch (MPC8xx);
4210 define relocation offset in DPRAM [SMC1]
4212 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4213 enable SPI microcode relocation patch (MPC8xx);
4214 define relocation offset in DPRAM [SCC4]
4216 - CONFIG_SYS_USE_OSCCLK:
4217 Use OSCM clock mode on MBX8xx board. Be careful,
4218 wrong setting might damage your board. Read
4219 doc/README.MBX before setting this variable!
4221 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4222 Offset of the bootmode word in DPRAM used by post
4223 (Power On Self Tests). This definition overrides
4224 #define'd default value in commproc.h resp.
4227 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4228 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4229 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4230 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4231 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4232 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4233 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4234 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4235 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4237 - CONFIG_PCI_DISABLE_PCIE:
4238 Disable PCI-Express on systems where it is supported but not
4241 - CONFIG_PCI_ENUM_ONLY
4242 Only scan through and get the devices on the busses.
4243 Don't do any setup work, presumably because someone or
4244 something has already done it, and we don't need to do it
4245 a second time. Useful for platforms that are pre-booted
4246 by coreboot or similar.
4248 - CONFIG_PCI_INDIRECT_BRIDGE:
4249 Enable support for indirect PCI bridges.
4252 Chip has SRIO or not
4255 Board has SRIO 1 port available
4258 Board has SRIO 2 port available
4260 - CONFIG_SRIO_PCIE_BOOT_MASTER
4261 Board can support master function for Boot from SRIO and PCIE
4263 - CONFIG_SYS_SRIOn_MEM_VIRT:
4264 Virtual Address of SRIO port 'n' memory region
4266 - CONFIG_SYS_SRIOn_MEM_PHYS:
4267 Physical Address of SRIO port 'n' memory region
4269 - CONFIG_SYS_SRIOn_MEM_SIZE:
4270 Size of SRIO port 'n' memory region
4272 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4273 Defined to tell the NAND controller that the NAND chip is using
4275 Not all NAND drivers use this symbol.
4276 Example of drivers that use it:
4277 - drivers/mtd/nand/ndfc.c
4278 - drivers/mtd/nand/mxc_nand.c
4280 - CONFIG_SYS_NDFC_EBC0_CFG
4281 Sets the EBC0_CFG register for the NDFC. If not defined
4282 a default value will be used.
4285 Get DDR timing information from an I2C EEPROM. Common
4286 with pluggable memory modules such as SODIMMs
4289 I2C address of the SPD EEPROM
4291 - CONFIG_SYS_SPD_BUS_NUM
4292 If SPD EEPROM is on an I2C bus other than the first
4293 one, specify here. Note that the value must resolve
4294 to something your driver can deal with.
4296 - CONFIG_SYS_DDR_RAW_TIMING
4297 Get DDR timing information from other than SPD. Common with
4298 soldered DDR chips onboard without SPD. DDR raw timing
4299 parameters are extracted from datasheet and hard-coded into
4300 header files or board specific files.
4302 - CONFIG_FSL_DDR_INTERACTIVE
4303 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4305 - CONFIG_SYS_83XX_DDR_USES_CS0
4306 Only for 83xx systems. If specified, then DDR should
4307 be configured using CS0 and CS1 instead of CS2 and CS3.
4309 - CONFIG_ETHER_ON_FEC[12]
4310 Define to enable FEC[12] on a 8xx series processor.
4312 - CONFIG_FEC[12]_PHY
4313 Define to the hardcoded PHY address which corresponds
4314 to the given FEC; i. e.
4315 #define CONFIG_FEC1_PHY 4
4316 means that the PHY with address 4 is connected to FEC1
4318 When set to -1, means to probe for first available.
4320 - CONFIG_FEC[12]_PHY_NORXERR
4321 The PHY does not have a RXERR line (RMII only).
4322 (so program the FEC to ignore it).
4325 Enable RMII mode for all FECs.
4326 Note that this is a global option, we can't
4327 have one FEC in standard MII mode and another in RMII mode.
4329 - CONFIG_CRC32_VERIFY
4330 Add a verify option to the crc32 command.
4333 => crc32 -v <address> <count> <crc32>
4335 Where address/count indicate a memory area
4336 and crc32 is the correct crc32 which the
4340 Add the "loopw" memory command. This only takes effect if
4341 the memory commands are activated globally (CONFIG_CMD_MEM).
4344 Add the "mdc" and "mwc" memory commands. These are cyclic
4349 This command will print 4 bytes (10,11,12,13) each 500 ms.
4351 => mwc.l 100 12345678 10
4352 This command will write 12345678 to address 100 all 10 ms.
4354 This only takes effect if the memory commands are activated
4355 globally (CONFIG_CMD_MEM).
4357 - CONFIG_SKIP_LOWLEVEL_INIT
4358 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4359 low level initializations (like setting up the memory
4360 controller) are omitted and/or U-Boot does not
4361 relocate itself into RAM.
4363 Normally this variable MUST NOT be defined. The only
4364 exception is when U-Boot is loaded (to RAM) by some
4365 other boot loader or by a debugger which performs
4366 these initializations itself.
4369 Modifies the behaviour of start.S when compiling a loader
4370 that is executed before the actual U-Boot. E.g. when
4371 compiling a NAND SPL.
4374 Modifies the behaviour of start.S when compiling a loader
4375 that is executed after the SPL and before the actual U-Boot.
4376 It is loaded by the SPL.
4378 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4379 Only for 85xx systems. If this variable is specified, the section
4380 .resetvec is not kept and the section .bootpg is placed in the
4381 previous 4k of the .text section.
4383 - CONFIG_ARCH_MAP_SYSMEM
4384 Generally U-Boot (and in particular the md command) uses
4385 effective address. It is therefore not necessary to regard
4386 U-Boot address as virtual addresses that need to be translated
4387 to physical addresses. However, sandbox requires this, since
4388 it maintains its own little RAM buffer which contains all
4389 addressable memory. This option causes some memory accesses
4390 to be mapped through map_sysmem() / unmap_sysmem().
4392 - CONFIG_USE_ARCH_MEMCPY
4393 CONFIG_USE_ARCH_MEMSET
4394 If these options are used a optimized version of memcpy/memset will
4395 be used if available. These functions may be faster under some
4396 conditions but may increase the binary size.
4398 - CONFIG_X86_RESET_VECTOR
4399 If defined, the x86 reset vector code is included. This is not
4400 needed when U-Boot is running from Coreboot.
4403 Defines the MPU clock speed (in MHz).
4405 NOTE : currently only supported on AM335x platforms.
4407 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4408 Enables the RTC32K OSC on AM33xx based plattforms
4410 Freescale QE/FMAN Firmware Support:
4411 -----------------------------------
4413 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4414 loading of "firmware", which is encoded in the QE firmware binary format.
4415 This firmware often needs to be loaded during U-Boot booting, so macros
4416 are used to identify the storage device (NOR flash, SPI, etc) and the address
4419 - CONFIG_SYS_QE_FMAN_FW_ADDR
4420 The address in the storage device where the firmware is located. The
4421 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4424 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4425 The maximum possible size of the firmware. The firmware binary format
4426 has a field that specifies the actual size of the firmware, but it
4427 might not be possible to read any part of the firmware unless some
4428 local storage is allocated to hold the entire firmware first.
4430 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4431 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4432 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4433 virtual address in NOR flash.
4435 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4436 Specifies that QE/FMAN firmware is located in NAND flash.
4437 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4439 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4440 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4441 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4443 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4444 Specifies that QE/FMAN firmware is located on the primary SPI
4445 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4447 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4448 Specifies that QE/FMAN firmware is located in the remote (master)
4449 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4450 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4451 window->master inbound window->master LAW->the ucode address in
4452 master's memory space.
4454 Building the Software:
4455 ======================
4457 Building U-Boot has been tested in several native build environments
4458 and in many different cross environments. Of course we cannot support
4459 all possibly existing versions of cross development tools in all
4460 (potentially obsolete) versions. In case of tool chain problems we
4461 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4462 which is extensively used to build and test U-Boot.
4464 If you are not using a native environment, it is assumed that you
4465 have GNU cross compiling tools available in your path. In this case,
4466 you must set the environment variable CROSS_COMPILE in your shell.
4467 Note that no changes to the Makefile or any other source files are
4468 necessary. For example using the ELDK on a 4xx CPU, please enter:
4470 $ CROSS_COMPILE=ppc_4xx-
4471 $ export CROSS_COMPILE
4473 Note: If you wish to generate Windows versions of the utilities in
4474 the tools directory you can use the MinGW toolchain
4475 (http://www.mingw.org). Set your HOST tools to the MinGW
4476 toolchain and execute 'make tools'. For example:
4478 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4480 Binaries such as tools/mkimage.exe will be created which can
4481 be executed on computers running Windows.
4483 U-Boot is intended to be simple to build. After installing the
4484 sources you must configure U-Boot for one specific board type. This
4489 where "NAME_config" is the name of one of the existing configu-
4490 rations; see boards.cfg for supported names.
4492 Note: for some board special configuration names may exist; check if
4493 additional information is available from the board vendor; for
4494 instance, the TQM823L systems are available without (standard)
4495 or with LCD support. You can select such additional "features"
4496 when choosing the configuration, i. e.
4499 - will configure for a plain TQM823L, i. e. no LCD support
4501 make TQM823L_LCD_config
4502 - will configure for a TQM823L with U-Boot console on LCD
4507 Finally, type "make all", and you should get some working U-Boot
4508 images ready for download to / installation on your system:
4510 - "u-boot.bin" is a raw binary image
4511 - "u-boot" is an image in ELF binary format
4512 - "u-boot.srec" is in Motorola S-Record format
4514 By default the build is performed locally and the objects are saved
4515 in the source directory. One of the two methods can be used to change
4516 this behavior and build U-Boot to some external directory:
4518 1. Add O= to the make command line invocations:
4520 make O=/tmp/build distclean
4521 make O=/tmp/build NAME_config
4522 make O=/tmp/build all
4524 2. Set environment variable BUILD_DIR to point to the desired location:
4526 export BUILD_DIR=/tmp/build
4531 Note that the command line "O=" setting overrides the BUILD_DIR environment
4535 Please be aware that the Makefiles assume you are using GNU make, so
4536 for instance on NetBSD you might need to use "gmake" instead of
4540 If the system board that you have is not listed, then you will need
4541 to port U-Boot to your hardware platform. To do this, follow these
4544 1. Add a new configuration option for your board to the toplevel
4545 "boards.cfg" file, using the existing entries as examples.
4546 Follow the instructions there to keep the boards in order.
4547 2. Create a new directory to hold your board specific code. Add any
4548 files you need. In your board directory, you will need at least
4549 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4550 3. Create a new configuration file "include/configs/<board>.h" for
4552 3. If you're porting U-Boot to a new CPU, then also create a new
4553 directory to hold your CPU specific code. Add any files you need.
4554 4. Run "make <board>_config" with your new name.
4555 5. Type "make", and you should get a working "u-boot.srec" file
4556 to be installed on your target system.
4557 6. Debug and solve any problems that might arise.
4558 [Of course, this last step is much harder than it sounds.]
4561 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4562 ==============================================================
4564 If you have modified U-Boot sources (for instance added a new board
4565 or support for new devices, a new CPU, etc.) you are expected to
4566 provide feedback to the other developers. The feedback normally takes
4567 the form of a "patch", i. e. a context diff against a certain (latest
4568 official or latest in the git repository) version of U-Boot sources.
4570 But before you submit such a patch, please verify that your modifi-
4571 cation did not break existing code. At least make sure that *ALL* of
4572 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4573 just run the "MAKEALL" script, which will configure and build U-Boot
4574 for ALL supported system. Be warned, this will take a while. You can
4575 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4576 environment variable to the script, i. e. to use the ELDK cross tools
4579 CROSS_COMPILE=ppc_8xx- MAKEALL
4581 or to build on a native PowerPC system you can type
4583 CROSS_COMPILE=' ' MAKEALL
4585 When using the MAKEALL script, the default behaviour is to build
4586 U-Boot in the source directory. This location can be changed by
4587 setting the BUILD_DIR environment variable. Also, for each target
4588 built, the MAKEALL script saves two log files (<target>.ERR and
4589 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4590 location can be changed by setting the MAKEALL_LOGDIR environment
4591 variable. For example:
4593 export BUILD_DIR=/tmp/build
4594 export MAKEALL_LOGDIR=/tmp/log
4595 CROSS_COMPILE=ppc_8xx- MAKEALL
4597 With the above settings build objects are saved in the /tmp/build,
4598 log files are saved in the /tmp/log and the source tree remains clean
4599 during the whole build process.
4602 See also "U-Boot Porting Guide" below.
4605 Monitor Commands - Overview:
4606 ============================
4608 go - start application at address 'addr'
4609 run - run commands in an environment variable
4610 bootm - boot application image from memory
4611 bootp - boot image via network using BootP/TFTP protocol
4612 bootz - boot zImage from memory
4613 tftpboot- boot image via network using TFTP protocol
4614 and env variables "ipaddr" and "serverip"
4615 (and eventually "gatewayip")
4616 tftpput - upload a file via network using TFTP protocol
4617 rarpboot- boot image via network using RARP/TFTP protocol
4618 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4619 loads - load S-Record file over serial line
4620 loadb - load binary file over serial line (kermit mode)
4622 mm - memory modify (auto-incrementing)
4623 nm - memory modify (constant address)
4624 mw - memory write (fill)
4626 cmp - memory compare
4627 crc32 - checksum calculation
4628 i2c - I2C sub-system
4629 sspi - SPI utility commands
4630 base - print or set address offset
4631 printenv- print environment variables
4632 setenv - set environment variables
4633 saveenv - save environment variables to persistent storage
4634 protect - enable or disable FLASH write protection
4635 erase - erase FLASH memory
4636 flinfo - print FLASH memory information
4637 nand - NAND memory operations (see doc/README.nand)
4638 bdinfo - print Board Info structure
4639 iminfo - print header information for application image
4640 coninfo - print console devices and informations
4641 ide - IDE sub-system
4642 loop - infinite loop on address range
4643 loopw - infinite write loop on address range
4644 mtest - simple RAM test
4645 icache - enable or disable instruction cache
4646 dcache - enable or disable data cache
4647 reset - Perform RESET of the CPU
4648 echo - echo args to console
4649 version - print monitor version
4650 help - print online help
4651 ? - alias for 'help'
4654 Monitor Commands - Detailed Description:
4655 ========================================
4659 For now: just type "help <command>".
4662 Environment Variables:
4663 ======================
4665 U-Boot supports user configuration using Environment Variables which
4666 can be made persistent by saving to Flash memory.
4668 Environment Variables are set using "setenv", printed using
4669 "printenv", and saved to Flash using "saveenv". Using "setenv"
4670 without a value can be used to delete a variable from the
4671 environment. As long as you don't save the environment you are
4672 working with an in-memory copy. In case the Flash area containing the
4673 environment is erased by accident, a default environment is provided.
4675 Some configuration options can be set using Environment Variables.
4677 List of environment variables (most likely not complete):
4679 baudrate - see CONFIG_BAUDRATE
4681 bootdelay - see CONFIG_BOOTDELAY
4683 bootcmd - see CONFIG_BOOTCOMMAND
4685 bootargs - Boot arguments when booting an RTOS image
4687 bootfile - Name of the image to load with TFTP
4689 bootm_low - Memory range available for image processing in the bootm
4690 command can be restricted. This variable is given as
4691 a hexadecimal number and defines lowest address allowed
4692 for use by the bootm command. See also "bootm_size"
4693 environment variable. Address defined by "bootm_low" is
4694 also the base of the initial memory mapping for the Linux
4695 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4698 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4699 This variable is given as a hexadecimal number and it
4700 defines the size of the memory region starting at base
4701 address bootm_low that is accessible by the Linux kernel
4702 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4703 as the default value if it is defined, and bootm_size is
4706 bootm_size - Memory range available for image processing in the bootm
4707 command can be restricted. This variable is given as
4708 a hexadecimal number and defines the size of the region
4709 allowed for use by the bootm command. See also "bootm_low"
4710 environment variable.
4712 updatefile - Location of the software update file on a TFTP server, used
4713 by the automatic software update feature. Please refer to
4714 documentation in doc/README.update for more details.
4716 autoload - if set to "no" (any string beginning with 'n'),
4717 "bootp" will just load perform a lookup of the
4718 configuration from the BOOTP server, but not try to
4719 load any image using TFTP
4721 autostart - if set to "yes", an image loaded using the "bootp",
4722 "rarpboot", "tftpboot" or "diskboot" commands will
4723 be automatically started (by internally calling
4726 If set to "no", a standalone image passed to the
4727 "bootm" command will be copied to the load address
4728 (and eventually uncompressed), but NOT be started.
4729 This can be used to load and uncompress arbitrary
4732 fdt_high - if set this restricts the maximum address that the
4733 flattened device tree will be copied into upon boot.
4734 For example, if you have a system with 1 GB memory
4735 at physical address 0x10000000, while Linux kernel
4736 only recognizes the first 704 MB as low memory, you
4737 may need to set fdt_high as 0x3C000000 to have the
4738 device tree blob be copied to the maximum address
4739 of the 704 MB low memory, so that Linux kernel can
4740 access it during the boot procedure.
4742 If this is set to the special value 0xFFFFFFFF then
4743 the fdt will not be copied at all on boot. For this
4744 to work it must reside in writable memory, have
4745 sufficient padding on the end of it for u-boot to
4746 add the information it needs into it, and the memory
4747 must be accessible by the kernel.
4749 fdtcontroladdr- if set this is the address of the control flattened
4750 device tree used by U-Boot when CONFIG_OF_CONTROL is
4753 i2cfast - (PPC405GP|PPC405EP only)
4754 if set to 'y' configures Linux I2C driver for fast
4755 mode (400kHZ). This environment variable is used in
4756 initialization code. So, for changes to be effective
4757 it must be saved and board must be reset.
4759 initrd_high - restrict positioning of initrd images:
4760 If this variable is not set, initrd images will be
4761 copied to the highest possible address in RAM; this
4762 is usually what you want since it allows for
4763 maximum initrd size. If for some reason you want to
4764 make sure that the initrd image is loaded below the
4765 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4766 variable to a value of "no" or "off" or "0".
4767 Alternatively, you can set it to a maximum upper
4768 address to use (U-Boot will still check that it
4769 does not overwrite the U-Boot stack and data).
4771 For instance, when you have a system with 16 MB
4772 RAM, and want to reserve 4 MB from use by Linux,
4773 you can do this by adding "mem=12M" to the value of
4774 the "bootargs" variable. However, now you must make
4775 sure that the initrd image is placed in the first
4776 12 MB as well - this can be done with
4778 setenv initrd_high 00c00000
4780 If you set initrd_high to 0xFFFFFFFF, this is an
4781 indication to U-Boot that all addresses are legal
4782 for the Linux kernel, including addresses in flash
4783 memory. In this case U-Boot will NOT COPY the
4784 ramdisk at all. This may be useful to reduce the
4785 boot time on your system, but requires that this
4786 feature is supported by your Linux kernel.
4788 ipaddr - IP address; needed for tftpboot command
4790 loadaddr - Default load address for commands like "bootp",
4791 "rarpboot", "tftpboot", "loadb" or "diskboot"
4793 loads_echo - see CONFIG_LOADS_ECHO
4795 serverip - TFTP server IP address; needed for tftpboot command
4797 bootretry - see CONFIG_BOOT_RETRY_TIME
4799 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4801 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4803 ethprime - controls which interface is used first.
4805 ethact - controls which interface is currently active.
4806 For example you can do the following
4808 => setenv ethact FEC
4809 => ping 192.168.0.1 # traffic sent on FEC
4810 => setenv ethact SCC
4811 => ping 10.0.0.1 # traffic sent on SCC
4813 ethrotate - When set to "no" U-Boot does not go through all
4814 available network interfaces.
4815 It just stays at the currently selected interface.
4817 netretry - When set to "no" each network operation will
4818 either succeed or fail without retrying.
4819 When set to "once" the network operation will
4820 fail when all the available network interfaces
4821 are tried once without success.
4822 Useful on scripts which control the retry operation
4825 npe_ucode - set load address for the NPE microcode
4827 silent_linux - If set then linux will be told to boot silently, by
4828 changing the console to be empty. If "yes" it will be
4829 made silent. If "no" it will not be made silent. If
4830 unset, then it will be made silent if the U-Boot console
4833 tftpsrcport - If this is set, the value is used for TFTP's
4836 tftpdstport - If this is set, the value is used for TFTP's UDP
4837 destination port instead of the Well Know Port 69.
4839 tftpblocksize - Block size to use for TFTP transfers; if not set,
4840 we use the TFTP server's default block size
4842 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4843 seconds, minimum value is 1000 = 1 second). Defines
4844 when a packet is considered to be lost so it has to
4845 be retransmitted. The default is 5000 = 5 seconds.
4846 Lowering this value may make downloads succeed
4847 faster in networks with high packet loss rates or
4848 with unreliable TFTP servers.
4850 vlan - When set to a value < 4095 the traffic over
4851 Ethernet is encapsulated/received over 802.1q
4854 The following image location variables contain the location of images
4855 used in booting. The "Image" column gives the role of the image and is
4856 not an environment variable name. The other columns are environment
4857 variable names. "File Name" gives the name of the file on a TFTP
4858 server, "RAM Address" gives the location in RAM the image will be
4859 loaded to, and "Flash Location" gives the image's address in NOR
4860 flash or offset in NAND flash.
4862 *Note* - these variables don't have to be defined for all boards, some
4863 boards currenlty use other variables for these purposes, and some
4864 boards use these variables for other purposes.
4866 Image File Name RAM Address Flash Location
4867 ----- --------- ----------- --------------
4868 u-boot u-boot u-boot_addr_r u-boot_addr
4869 Linux kernel bootfile kernel_addr_r kernel_addr
4870 device tree blob fdtfile fdt_addr_r fdt_addr
4871 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4873 The following environment variables may be used and automatically
4874 updated by the network boot commands ("bootp" and "rarpboot"),
4875 depending the information provided by your boot server:
4877 bootfile - see above
4878 dnsip - IP address of your Domain Name Server
4879 dnsip2 - IP address of your secondary Domain Name Server
4880 gatewayip - IP address of the Gateway (Router) to use
4881 hostname - Target hostname
4883 netmask - Subnet Mask
4884 rootpath - Pathname of the root filesystem on the NFS server
4885 serverip - see above
4888 There are two special Environment Variables:
4890 serial# - contains hardware identification information such
4891 as type string and/or serial number
4892 ethaddr - Ethernet address
4894 These variables can be set only once (usually during manufacturing of
4895 the board). U-Boot refuses to delete or overwrite these variables
4896 once they have been set once.
4899 Further special Environment Variables:
4901 ver - Contains the U-Boot version string as printed
4902 with the "version" command. This variable is
4903 readonly (see CONFIG_VERSION_VARIABLE).
4906 Please note that changes to some configuration parameters may take
4907 only effect after the next boot (yes, that's just like Windoze :-).
4910 Callback functions for environment variables:
4911 ---------------------------------------------
4913 For some environment variables, the behavior of u-boot needs to change
4914 when their values are changed. This functionailty allows functions to
4915 be associated with arbitrary variables. On creation, overwrite, or
4916 deletion, the callback will provide the opportunity for some side
4917 effect to happen or for the change to be rejected.
4919 The callbacks are named and associated with a function using the
4920 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4922 These callbacks are associated with variables in one of two ways. The
4923 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4924 in the board configuration to a string that defines a list of
4925 associations. The list must be in the following format:
4927 entry = variable_name[:callback_name]
4930 If the callback name is not specified, then the callback is deleted.
4931 Spaces are also allowed anywhere in the list.
4933 Callbacks can also be associated by defining the ".callbacks" variable
4934 with the same list format above. Any association in ".callbacks" will
4935 override any association in the static list. You can define
4936 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4937 ".callbacks" envirnoment variable in the default or embedded environment.
4940 Command Line Parsing:
4941 =====================
4943 There are two different command line parsers available with U-Boot:
4944 the old "simple" one, and the much more powerful "hush" shell:
4946 Old, simple command line parser:
4947 --------------------------------
4949 - supports environment variables (through setenv / saveenv commands)
4950 - several commands on one line, separated by ';'
4951 - variable substitution using "... ${name} ..." syntax
4952 - special characters ('$', ';') can be escaped by prefixing with '\',
4954 setenv bootcmd bootm \${address}
4955 - You can also escape text by enclosing in single apostrophes, for example:
4956 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4961 - similar to Bourne shell, with control structures like
4962 if...then...else...fi, for...do...done; while...do...done,
4963 until...do...done, ...
4964 - supports environment ("global") variables (through setenv / saveenv
4965 commands) and local shell variables (through standard shell syntax
4966 "name=value"); only environment variables can be used with "run"
4972 (1) If a command line (or an environment variable executed by a "run"
4973 command) contains several commands separated by semicolon, and
4974 one of these commands fails, then the remaining commands will be
4977 (2) If you execute several variables with one call to run (i. e.
4978 calling run with a list of variables as arguments), any failing
4979 command will cause "run" to terminate, i. e. the remaining
4980 variables are not executed.
4982 Note for Redundant Ethernet Interfaces:
4983 =======================================
4985 Some boards come with redundant Ethernet interfaces; U-Boot supports
4986 such configurations and is capable of automatic selection of a
4987 "working" interface when needed. MAC assignment works as follows:
4989 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4990 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4991 "eth1addr" (=>eth1), "eth2addr", ...
4993 If the network interface stores some valid MAC address (for instance
4994 in SROM), this is used as default address if there is NO correspon-
4995 ding setting in the environment; if the corresponding environment
4996 variable is set, this overrides the settings in the card; that means:
4998 o If the SROM has a valid MAC address, and there is no address in the
4999 environment, the SROM's address is used.
5001 o If there is no valid address in the SROM, and a definition in the
5002 environment exists, then the value from the environment variable is
5005 o If both the SROM and the environment contain a MAC address, and
5006 both addresses are the same, this MAC address is used.
5008 o If both the SROM and the environment contain a MAC address, and the
5009 addresses differ, the value from the environment is used and a
5012 o If neither SROM nor the environment contain a MAC address, an error
5015 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5016 will be programmed into hardware as part of the initialization process. This
5017 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5018 The naming convention is as follows:
5019 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5024 U-Boot is capable of booting (and performing other auxiliary operations on)
5025 images in two formats:
5027 New uImage format (FIT)
5028 -----------------------
5030 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5031 to Flattened Device Tree). It allows the use of images with multiple
5032 components (several kernels, ramdisks, etc.), with contents protected by
5033 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5039 Old image format is based on binary files which can be basically anything,
5040 preceded by a special header; see the definitions in include/image.h for
5041 details; basically, the header defines the following image properties:
5043 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5044 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5045 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5046 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5048 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5049 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5050 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5051 * Compression Type (uncompressed, gzip, bzip2)
5057 The header is marked by a special Magic Number, and both the header
5058 and the data portions of the image are secured against corruption by
5065 Although U-Boot should support any OS or standalone application
5066 easily, the main focus has always been on Linux during the design of
5069 U-Boot includes many features that so far have been part of some
5070 special "boot loader" code within the Linux kernel. Also, any
5071 "initrd" images to be used are no longer part of one big Linux image;
5072 instead, kernel and "initrd" are separate images. This implementation
5073 serves several purposes:
5075 - the same features can be used for other OS or standalone
5076 applications (for instance: using compressed images to reduce the
5077 Flash memory footprint)
5079 - it becomes much easier to port new Linux kernel versions because
5080 lots of low-level, hardware dependent stuff are done by U-Boot
5082 - the same Linux kernel image can now be used with different "initrd"
5083 images; of course this also means that different kernel images can
5084 be run with the same "initrd". This makes testing easier (you don't
5085 have to build a new "zImage.initrd" Linux image when you just
5086 change a file in your "initrd"). Also, a field-upgrade of the
5087 software is easier now.
5093 Porting Linux to U-Boot based systems:
5094 ---------------------------------------
5096 U-Boot cannot save you from doing all the necessary modifications to
5097 configure the Linux device drivers for use with your target hardware
5098 (no, we don't intend to provide a full virtual machine interface to
5101 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5103 Just make sure your machine specific header file (for instance
5104 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5105 Information structure as we define in include/asm-<arch>/u-boot.h,
5106 and make sure that your definition of IMAP_ADDR uses the same value
5107 as your U-Boot configuration in CONFIG_SYS_IMMR.
5110 Configuring the Linux kernel:
5111 -----------------------------
5113 No specific requirements for U-Boot. Make sure you have some root
5114 device (initial ramdisk, NFS) for your target system.
5117 Building a Linux Image:
5118 -----------------------
5120 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5121 not used. If you use recent kernel source, a new build target
5122 "uImage" will exist which automatically builds an image usable by
5123 U-Boot. Most older kernels also have support for a "pImage" target,
5124 which was introduced for our predecessor project PPCBoot and uses a
5125 100% compatible format.
5134 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5135 encapsulate a compressed Linux kernel image with header information,
5136 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5138 * build a standard "vmlinux" kernel image (in ELF binary format):
5140 * convert the kernel into a raw binary image:
5142 ${CROSS_COMPILE}-objcopy -O binary \
5143 -R .note -R .comment \
5144 -S vmlinux linux.bin
5146 * compress the binary image:
5150 * package compressed binary image for U-Boot:
5152 mkimage -A ppc -O linux -T kernel -C gzip \
5153 -a 0 -e 0 -n "Linux Kernel Image" \
5154 -d linux.bin.gz uImage
5157 The "mkimage" tool can also be used to create ramdisk images for use
5158 with U-Boot, either separated from the Linux kernel image, or
5159 combined into one file. "mkimage" encapsulates the images with a 64
5160 byte header containing information about target architecture,
5161 operating system, image type, compression method, entry points, time
5162 stamp, CRC32 checksums, etc.
5164 "mkimage" can be called in two ways: to verify existing images and
5165 print the header information, or to build new images.
5167 In the first form (with "-l" option) mkimage lists the information
5168 contained in the header of an existing U-Boot image; this includes
5169 checksum verification:
5171 tools/mkimage -l image
5172 -l ==> list image header information
5174 The second form (with "-d" option) is used to build a U-Boot image
5175 from a "data file" which is used as image payload:
5177 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5178 -n name -d data_file image
5179 -A ==> set architecture to 'arch'
5180 -O ==> set operating system to 'os'
5181 -T ==> set image type to 'type'
5182 -C ==> set compression type 'comp'
5183 -a ==> set load address to 'addr' (hex)
5184 -e ==> set entry point to 'ep' (hex)
5185 -n ==> set image name to 'name'
5186 -d ==> use image data from 'datafile'
5188 Right now, all Linux kernels for PowerPC systems use the same load
5189 address (0x00000000), but the entry point address depends on the
5192 - 2.2.x kernels have the entry point at 0x0000000C,
5193 - 2.3.x and later kernels have the entry point at 0x00000000.
5195 So a typical call to build a U-Boot image would read:
5197 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5198 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5199 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5200 > examples/uImage.TQM850L
5201 Image Name: 2.4.4 kernel for TQM850L
5202 Created: Wed Jul 19 02:34:59 2000
5203 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5204 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5205 Load Address: 0x00000000
5206 Entry Point: 0x00000000
5208 To verify the contents of the image (or check for corruption):
5210 -> tools/mkimage -l examples/uImage.TQM850L
5211 Image Name: 2.4.4 kernel for TQM850L
5212 Created: Wed Jul 19 02:34:59 2000
5213 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5214 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5215 Load Address: 0x00000000
5216 Entry Point: 0x00000000
5218 NOTE: for embedded systems where boot time is critical you can trade
5219 speed for memory and install an UNCOMPRESSED image instead: this
5220 needs more space in Flash, but boots much faster since it does not
5221 need to be uncompressed:
5223 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5224 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5225 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5226 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5227 > examples/uImage.TQM850L-uncompressed
5228 Image Name: 2.4.4 kernel for TQM850L
5229 Created: Wed Jul 19 02:34:59 2000
5230 Image Type: PowerPC Linux Kernel Image (uncompressed)
5231 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5232 Load Address: 0x00000000
5233 Entry Point: 0x00000000
5236 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5237 when your kernel is intended to use an initial ramdisk:
5239 -> tools/mkimage -n 'Simple Ramdisk Image' \
5240 > -A ppc -O linux -T ramdisk -C gzip \
5241 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5242 Image Name: Simple Ramdisk Image
5243 Created: Wed Jan 12 14:01:50 2000
5244 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5245 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5246 Load Address: 0x00000000
5247 Entry Point: 0x00000000
5250 Installing a Linux Image:
5251 -------------------------
5253 To downloading a U-Boot image over the serial (console) interface,
5254 you must convert the image to S-Record format:
5256 objcopy -I binary -O srec examples/image examples/image.srec
5258 The 'objcopy' does not understand the information in the U-Boot
5259 image header, so the resulting S-Record file will be relative to
5260 address 0x00000000. To load it to a given address, you need to
5261 specify the target address as 'offset' parameter with the 'loads'
5264 Example: install the image to address 0x40100000 (which on the
5265 TQM8xxL is in the first Flash bank):
5267 => erase 40100000 401FFFFF
5273 ## Ready for S-Record download ...
5274 ~>examples/image.srec
5275 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5277 15989 15990 15991 15992
5278 [file transfer complete]
5280 ## Start Addr = 0x00000000
5283 You can check the success of the download using the 'iminfo' command;
5284 this includes a checksum verification so you can be sure no data
5285 corruption happened:
5289 ## Checking Image at 40100000 ...
5290 Image Name: 2.2.13 for initrd on TQM850L
5291 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5292 Data Size: 335725 Bytes = 327 kB = 0 MB
5293 Load Address: 00000000
5294 Entry Point: 0000000c
5295 Verifying Checksum ... OK
5301 The "bootm" command is used to boot an application that is stored in
5302 memory (RAM or Flash). In case of a Linux kernel image, the contents
5303 of the "bootargs" environment variable is passed to the kernel as
5304 parameters. You can check and modify this variable using the
5305 "printenv" and "setenv" commands:
5308 => printenv bootargs
5309 bootargs=root=/dev/ram
5311 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5313 => printenv bootargs
5314 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5317 ## Booting Linux kernel at 40020000 ...
5318 Image Name: 2.2.13 for NFS on TQM850L
5319 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5320 Data Size: 381681 Bytes = 372 kB = 0 MB
5321 Load Address: 00000000
5322 Entry Point: 0000000c
5323 Verifying Checksum ... OK
5324 Uncompressing Kernel Image ... OK
5325 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5326 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5327 time_init: decrementer frequency = 187500000/60
5328 Calibrating delay loop... 49.77 BogoMIPS
5329 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5332 If you want to boot a Linux kernel with initial RAM disk, you pass
5333 the memory addresses of both the kernel and the initrd image (PPBCOOT
5334 format!) to the "bootm" command:
5336 => imi 40100000 40200000
5338 ## Checking Image at 40100000 ...
5339 Image Name: 2.2.13 for initrd on TQM850L
5340 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5341 Data Size: 335725 Bytes = 327 kB = 0 MB
5342 Load Address: 00000000
5343 Entry Point: 0000000c
5344 Verifying Checksum ... OK
5346 ## Checking Image at 40200000 ...
5347 Image Name: Simple Ramdisk Image
5348 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5349 Data Size: 566530 Bytes = 553 kB = 0 MB
5350 Load Address: 00000000
5351 Entry Point: 00000000
5352 Verifying Checksum ... OK
5354 => bootm 40100000 40200000
5355 ## Booting Linux kernel at 40100000 ...
5356 Image Name: 2.2.13 for initrd on TQM850L
5357 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5358 Data Size: 335725 Bytes = 327 kB = 0 MB
5359 Load Address: 00000000
5360 Entry Point: 0000000c
5361 Verifying Checksum ... OK
5362 Uncompressing Kernel Image ... OK
5363 ## Loading RAMDisk Image at 40200000 ...
5364 Image Name: Simple Ramdisk Image
5365 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5366 Data Size: 566530 Bytes = 553 kB = 0 MB
5367 Load Address: 00000000
5368 Entry Point: 00000000
5369 Verifying Checksum ... OK
5370 Loading Ramdisk ... OK
5371 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5372 Boot arguments: root=/dev/ram
5373 time_init: decrementer frequency = 187500000/60
5374 Calibrating delay loop... 49.77 BogoMIPS
5376 RAMDISK: Compressed image found at block 0
5377 VFS: Mounted root (ext2 filesystem).
5381 Boot Linux and pass a flat device tree:
5384 First, U-Boot must be compiled with the appropriate defines. See the section
5385 titled "Linux Kernel Interface" above for a more in depth explanation. The
5386 following is an example of how to start a kernel and pass an updated
5392 oft=oftrees/mpc8540ads.dtb
5393 => tftp $oftaddr $oft
5394 Speed: 1000, full duplex
5396 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5397 Filename 'oftrees/mpc8540ads.dtb'.
5398 Load address: 0x300000
5401 Bytes transferred = 4106 (100a hex)
5402 => tftp $loadaddr $bootfile
5403 Speed: 1000, full duplex
5405 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5407 Load address: 0x200000
5408 Loading:############
5410 Bytes transferred = 1029407 (fb51f hex)
5415 => bootm $loadaddr - $oftaddr
5416 ## Booting image at 00200000 ...
5417 Image Name: Linux-2.6.17-dirty
5418 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5419 Data Size: 1029343 Bytes = 1005.2 kB
5420 Load Address: 00000000
5421 Entry Point: 00000000
5422 Verifying Checksum ... OK
5423 Uncompressing Kernel Image ... OK
5424 Booting using flat device tree at 0x300000
5425 Using MPC85xx ADS machine description
5426 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5430 More About U-Boot Image Types:
5431 ------------------------------
5433 U-Boot supports the following image types:
5435 "Standalone Programs" are directly runnable in the environment
5436 provided by U-Boot; it is expected that (if they behave
5437 well) you can continue to work in U-Boot after return from
5438 the Standalone Program.
5439 "OS Kernel Images" are usually images of some Embedded OS which
5440 will take over control completely. Usually these programs
5441 will install their own set of exception handlers, device
5442 drivers, set up the MMU, etc. - this means, that you cannot
5443 expect to re-enter U-Boot except by resetting the CPU.
5444 "RAMDisk Images" are more or less just data blocks, and their
5445 parameters (address, size) are passed to an OS kernel that is
5447 "Multi-File Images" contain several images, typically an OS
5448 (Linux) kernel image and one or more data images like
5449 RAMDisks. This construct is useful for instance when you want
5450 to boot over the network using BOOTP etc., where the boot
5451 server provides just a single image file, but you want to get
5452 for instance an OS kernel and a RAMDisk image.
5454 "Multi-File Images" start with a list of image sizes, each
5455 image size (in bytes) specified by an "uint32_t" in network
5456 byte order. This list is terminated by an "(uint32_t)0".
5457 Immediately after the terminating 0 follow the images, one by
5458 one, all aligned on "uint32_t" boundaries (size rounded up to
5459 a multiple of 4 bytes).
5461 "Firmware Images" are binary images containing firmware (like
5462 U-Boot or FPGA images) which usually will be programmed to
5465 "Script files" are command sequences that will be executed by
5466 U-Boot's command interpreter; this feature is especially
5467 useful when you configure U-Boot to use a real shell (hush)
5468 as command interpreter.
5470 Booting the Linux zImage:
5471 -------------------------
5473 On some platforms, it's possible to boot Linux zImage. This is done
5474 using the "bootz" command. The syntax of "bootz" command is the same
5475 as the syntax of "bootm" command.
5477 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5478 kernel with raw initrd images. The syntax is slightly different, the
5479 address of the initrd must be augmented by it's size, in the following
5480 format: "<initrd addres>:<initrd size>".
5486 One of the features of U-Boot is that you can dynamically load and
5487 run "standalone" applications, which can use some resources of
5488 U-Boot like console I/O functions or interrupt services.
5490 Two simple examples are included with the sources:
5495 'examples/hello_world.c' contains a small "Hello World" Demo
5496 application; it is automatically compiled when you build U-Boot.
5497 It's configured to run at address 0x00040004, so you can play with it
5501 ## Ready for S-Record download ...
5502 ~>examples/hello_world.srec
5503 1 2 3 4 5 6 7 8 9 10 11 ...
5504 [file transfer complete]
5506 ## Start Addr = 0x00040004
5508 => go 40004 Hello World! This is a test.
5509 ## Starting application at 0x00040004 ...
5520 Hit any key to exit ...
5522 ## Application terminated, rc = 0x0
5524 Another example, which demonstrates how to register a CPM interrupt
5525 handler with the U-Boot code, can be found in 'examples/timer.c'.
5526 Here, a CPM timer is set up to generate an interrupt every second.
5527 The interrupt service routine is trivial, just printing a '.'
5528 character, but this is just a demo program. The application can be
5529 controlled by the following keys:
5531 ? - print current values og the CPM Timer registers
5532 b - enable interrupts and start timer
5533 e - stop timer and disable interrupts
5534 q - quit application
5537 ## Ready for S-Record download ...
5538 ~>examples/timer.srec
5539 1 2 3 4 5 6 7 8 9 10 11 ...
5540 [file transfer complete]
5542 ## Start Addr = 0x00040004
5545 ## Starting application at 0x00040004 ...
5548 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5551 [q, b, e, ?] Set interval 1000000 us
5554 [q, b, e, ?] ........
5555 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5558 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5561 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5564 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5566 [q, b, e, ?] ...Stopping timer
5568 [q, b, e, ?] ## Application terminated, rc = 0x0
5574 Over time, many people have reported problems when trying to use the
5575 "minicom" terminal emulation program for serial download. I (wd)
5576 consider minicom to be broken, and recommend not to use it. Under
5577 Unix, I recommend to use C-Kermit for general purpose use (and
5578 especially for kermit binary protocol download ("loadb" command), and
5579 use "cu" for S-Record download ("loads" command). See
5580 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5581 for help with kermit.
5584 Nevertheless, if you absolutely want to use it try adding this
5585 configuration to your "File transfer protocols" section:
5587 Name Program Name U/D FullScr IO-Red. Multi
5588 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5589 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5595 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5596 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5598 Building requires a cross environment; it is known to work on
5599 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5600 need gmake since the Makefiles are not compatible with BSD make).
5601 Note that the cross-powerpc package does not install include files;
5602 attempting to build U-Boot will fail because <machine/ansi.h> is
5603 missing. This file has to be installed and patched manually:
5605 # cd /usr/pkg/cross/powerpc-netbsd/include
5607 # ln -s powerpc machine
5608 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5609 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5611 Native builds *don't* work due to incompatibilities between native
5612 and U-Boot include files.
5614 Booting assumes that (the first part of) the image booted is a
5615 stage-2 loader which in turn loads and then invokes the kernel
5616 proper. Loader sources will eventually appear in the NetBSD source
5617 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5618 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5621 Implementation Internals:
5622 =========================
5624 The following is not intended to be a complete description of every
5625 implementation detail. However, it should help to understand the
5626 inner workings of U-Boot and make it easier to port it to custom
5630 Initial Stack, Global Data:
5631 ---------------------------
5633 The implementation of U-Boot is complicated by the fact that U-Boot
5634 starts running out of ROM (flash memory), usually without access to
5635 system RAM (because the memory controller is not initialized yet).
5636 This means that we don't have writable Data or BSS segments, and BSS
5637 is not initialized as zero. To be able to get a C environment working
5638 at all, we have to allocate at least a minimal stack. Implementation
5639 options for this are defined and restricted by the CPU used: Some CPU
5640 models provide on-chip memory (like the IMMR area on MPC8xx and
5641 MPC826x processors), on others (parts of) the data cache can be
5642 locked as (mis-) used as memory, etc.
5644 Chris Hallinan posted a good summary of these issues to the
5645 U-Boot mailing list:
5647 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5648 From: "Chris Hallinan" <clh@net1plus.com>
5649 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5652 Correct me if I'm wrong, folks, but the way I understand it
5653 is this: Using DCACHE as initial RAM for Stack, etc, does not
5654 require any physical RAM backing up the cache. The cleverness
5655 is that the cache is being used as a temporary supply of
5656 necessary storage before the SDRAM controller is setup. It's
5657 beyond the scope of this list to explain the details, but you
5658 can see how this works by studying the cache architecture and
5659 operation in the architecture and processor-specific manuals.
5661 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5662 is another option for the system designer to use as an
5663 initial stack/RAM area prior to SDRAM being available. Either
5664 option should work for you. Using CS 4 should be fine if your
5665 board designers haven't used it for something that would
5666 cause you grief during the initial boot! It is frequently not
5669 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5670 with your processor/board/system design. The default value
5671 you will find in any recent u-boot distribution in
5672 walnut.h should work for you. I'd set it to a value larger
5673 than your SDRAM module. If you have a 64MB SDRAM module, set
5674 it above 400_0000. Just make sure your board has no resources
5675 that are supposed to respond to that address! That code in
5676 start.S has been around a while and should work as is when
5677 you get the config right.
5682 It is essential to remember this, since it has some impact on the C
5683 code for the initialization procedures:
5685 * Initialized global data (data segment) is read-only. Do not attempt
5688 * Do not use any uninitialized global data (or implicitely initialized
5689 as zero data - BSS segment) at all - this is undefined, initiali-
5690 zation is performed later (when relocating to RAM).
5692 * Stack space is very limited. Avoid big data buffers or things like
5695 Having only the stack as writable memory limits means we cannot use
5696 normal global data to share information beween the code. But it
5697 turned out that the implementation of U-Boot can be greatly
5698 simplified by making a global data structure (gd_t) available to all
5699 functions. We could pass a pointer to this data as argument to _all_
5700 functions, but this would bloat the code. Instead we use a feature of
5701 the GCC compiler (Global Register Variables) to share the data: we
5702 place a pointer (gd) to the global data into a register which we
5703 reserve for this purpose.
5705 When choosing a register for such a purpose we are restricted by the
5706 relevant (E)ABI specifications for the current architecture, and by
5707 GCC's implementation.
5709 For PowerPC, the following registers have specific use:
5711 R2: reserved for system use
5712 R3-R4: parameter passing and return values
5713 R5-R10: parameter passing
5714 R13: small data area pointer
5718 (U-Boot also uses R12 as internal GOT pointer. r12
5719 is a volatile register so r12 needs to be reset when
5720 going back and forth between asm and C)
5722 ==> U-Boot will use R2 to hold a pointer to the global data
5724 Note: on PPC, we could use a static initializer (since the
5725 address of the global data structure is known at compile time),
5726 but it turned out that reserving a register results in somewhat
5727 smaller code - although the code savings are not that big (on
5728 average for all boards 752 bytes for the whole U-Boot image,
5729 624 text + 127 data).
5731 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5732 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5734 ==> U-Boot will use P3 to hold a pointer to the global data
5736 On ARM, the following registers are used:
5738 R0: function argument word/integer result
5739 R1-R3: function argument word
5740 R9: platform specific
5741 R10: stack limit (used only if stack checking is enabled)
5742 R11: argument (frame) pointer
5743 R12: temporary workspace
5746 R15: program counter
5748 ==> U-Boot will use R9 to hold a pointer to the global data
5750 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5752 On Nios II, the ABI is documented here:
5753 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5755 ==> U-Boot will use gp to hold a pointer to the global data
5757 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5758 to access small data sections, so gp is free.
5760 On NDS32, the following registers are used:
5762 R0-R1: argument/return
5764 R15: temporary register for assembler
5765 R16: trampoline register
5766 R28: frame pointer (FP)
5767 R29: global pointer (GP)
5768 R30: link register (LP)
5769 R31: stack pointer (SP)
5770 PC: program counter (PC)
5772 ==> U-Boot will use R10 to hold a pointer to the global data
5774 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5775 or current versions of GCC may "optimize" the code too much.
5780 U-Boot runs in system state and uses physical addresses, i.e. the
5781 MMU is not used either for address mapping nor for memory protection.
5783 The available memory is mapped to fixed addresses using the memory
5784 controller. In this process, a contiguous block is formed for each
5785 memory type (Flash, SDRAM, SRAM), even when it consists of several
5786 physical memory banks.
5788 U-Boot is installed in the first 128 kB of the first Flash bank (on
5789 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5790 booting and sizing and initializing DRAM, the code relocates itself
5791 to the upper end of DRAM. Immediately below the U-Boot code some
5792 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5793 configuration setting]. Below that, a structure with global Board
5794 Info data is placed, followed by the stack (growing downward).
5796 Additionally, some exception handler code is copied to the low 8 kB
5797 of DRAM (0x00000000 ... 0x00001FFF).
5799 So a typical memory configuration with 16 MB of DRAM could look like
5802 0x0000 0000 Exception Vector code
5805 0x0000 2000 Free for Application Use
5811 0x00FB FF20 Monitor Stack (Growing downward)
5812 0x00FB FFAC Board Info Data and permanent copy of global data
5813 0x00FC 0000 Malloc Arena
5816 0x00FE 0000 RAM Copy of Monitor Code
5817 ... eventually: LCD or video framebuffer
5818 ... eventually: pRAM (Protected RAM - unchanged by reset)
5819 0x00FF FFFF [End of RAM]
5822 System Initialization:
5823 ----------------------
5825 In the reset configuration, U-Boot starts at the reset entry point
5826 (on most PowerPC systems at address 0x00000100). Because of the reset
5827 configuration for CS0# this is a mirror of the onboard Flash memory.
5828 To be able to re-map memory U-Boot then jumps to its link address.
5829 To be able to implement the initialization code in C, a (small!)
5830 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5831 which provide such a feature like MPC8xx or MPC8260), or in a locked
5832 part of the data cache. After that, U-Boot initializes the CPU core,
5833 the caches and the SIU.
5835 Next, all (potentially) available memory banks are mapped using a
5836 preliminary mapping. For example, we put them on 512 MB boundaries
5837 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5838 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5839 programmed for SDRAM access. Using the temporary configuration, a
5840 simple memory test is run that determines the size of the SDRAM
5843 When there is more than one SDRAM bank, and the banks are of
5844 different size, the largest is mapped first. For equal size, the first
5845 bank (CS2#) is mapped first. The first mapping is always for address
5846 0x00000000, with any additional banks following immediately to create
5847 contiguous memory starting from 0.
5849 Then, the monitor installs itself at the upper end of the SDRAM area
5850 and allocates memory for use by malloc() and for the global Board
5851 Info data; also, the exception vector code is copied to the low RAM
5852 pages, and the final stack is set up.
5854 Only after this relocation will you have a "normal" C environment;
5855 until that you are restricted in several ways, mostly because you are
5856 running from ROM, and because the code will have to be relocated to a
5860 U-Boot Porting Guide:
5861 ----------------------
5863 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5867 int main(int argc, char *argv[])
5869 sighandler_t no_more_time;
5871 signal(SIGALRM, no_more_time);
5872 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5874 if (available_money > available_manpower) {
5875 Pay consultant to port U-Boot;
5879 Download latest U-Boot source;
5881 Subscribe to u-boot mailing list;
5884 email("Hi, I am new to U-Boot, how do I get started?");
5887 Read the README file in the top level directory;
5888 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5889 Read applicable doc/*.README;
5890 Read the source, Luke;
5891 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5894 if (available_money > toLocalCurrency ($2500))
5897 Add a lot of aggravation and time;
5899 if (a similar board exists) { /* hopefully... */
5900 cp -a board/<similar> board/<myboard>
5901 cp include/configs/<similar>.h include/configs/<myboard>.h
5903 Create your own board support subdirectory;
5904 Create your own board include/configs/<myboard>.h file;
5906 Edit new board/<myboard> files
5907 Edit new include/configs/<myboard>.h
5912 Add / modify source code;
5916 email("Hi, I am having problems...");
5918 Send patch file to the U-Boot email list;
5919 if (reasonable critiques)
5920 Incorporate improvements from email list code review;
5922 Defend code as written;
5928 void no_more_time (int sig)
5937 All contributions to U-Boot should conform to the Linux kernel
5938 coding style; see the file "Documentation/CodingStyle" and the script
5939 "scripts/Lindent" in your Linux kernel source directory.
5941 Source files originating from a different project (for example the
5942 MTD subsystem) are generally exempt from these guidelines and are not
5943 reformated to ease subsequent migration to newer versions of those
5946 Please note that U-Boot is implemented in C (and to some small parts in
5947 Assembler); no C++ is used, so please do not use C++ style comments (//)
5950 Please also stick to the following formatting rules:
5951 - remove any trailing white space
5952 - use TAB characters for indentation and vertical alignment, not spaces
5953 - make sure NOT to use DOS '\r\n' line feeds
5954 - do not add more than 2 consecutive empty lines to source files
5955 - do not add trailing empty lines to source files
5957 Submissions which do not conform to the standards may be returned
5958 with a request to reformat the changes.
5964 Since the number of patches for U-Boot is growing, we need to
5965 establish some rules. Submissions which do not conform to these rules
5966 may be rejected, even when they contain important and valuable stuff.
5968 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5970 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5971 see http://lists.denx.de/mailman/listinfo/u-boot
5973 When you send a patch, please include the following information with
5976 * For bug fixes: a description of the bug and how your patch fixes
5977 this bug. Please try to include a way of demonstrating that the
5978 patch actually fixes something.
5980 * For new features: a description of the feature and your
5983 * A CHANGELOG entry as plaintext (separate from the patch)
5985 * For major contributions, your entry to the CREDITS file
5987 * When you add support for a new board, don't forget to add a
5988 maintainer e-mail address to the boards.cfg file, too.
5990 * If your patch adds new configuration options, don't forget to
5991 document these in the README file.
5993 * The patch itself. If you are using git (which is *strongly*
5994 recommended) you can easily generate the patch using the
5995 "git format-patch". If you then use "git send-email" to send it to
5996 the U-Boot mailing list, you will avoid most of the common problems
5997 with some other mail clients.
5999 If you cannot use git, use "diff -purN OLD NEW". If your version of
6000 diff does not support these options, then get the latest version of
6003 The current directory when running this command shall be the parent
6004 directory of the U-Boot source tree (i. e. please make sure that
6005 your patch includes sufficient directory information for the
6008 We prefer patches as plain text. MIME attachments are discouraged,
6009 and compressed attachments must not be used.
6011 * If one logical set of modifications affects or creates several
6012 files, all these changes shall be submitted in a SINGLE patch file.
6014 * Changesets that contain different, unrelated modifications shall be
6015 submitted as SEPARATE patches, one patch per changeset.
6020 * Before sending the patch, run the MAKEALL script on your patched
6021 source tree and make sure that no errors or warnings are reported
6022 for any of the boards.
6024 * Keep your modifications to the necessary minimum: A patch
6025 containing several unrelated changes or arbitrary reformats will be
6026 returned with a request to re-formatting / split it.
6028 * If you modify existing code, make sure that your new code does not
6029 add to the memory footprint of the code ;-) Small is beautiful!
6030 When adding new features, these should compile conditionally only
6031 (using #ifdef), and the resulting code with the new feature
6032 disabled must not need more memory than the old code without your
6035 * Remember that there is a size limit of 100 kB per message on the
6036 u-boot mailing list. Bigger patches will be moderated. If they are
6037 reasonable and not too big, they will be acknowledged. But patches
6038 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob