2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /ixp Files specific to Intel XScale IXP CPUs
145 /pxa Files specific to Intel XScale PXA CPUs
146 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
147 /lib Architecture specific library files
148 /avr32 Files generic to AVR32 architecture
149 /cpu CPU specific files
150 /lib Architecture specific library files
151 /blackfin Files generic to Analog Devices Blackfin architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /m68k Files generic to m68k architecture
155 /cpu CPU specific files
156 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 /lib Architecture specific library files
162 /microblaze Files generic to microblaze architecture
163 /cpu CPU specific files
164 /lib Architecture specific library files
165 /mips Files generic to MIPS architecture
166 /cpu CPU specific files
167 /mips32 Files specific to MIPS32 CPUs
168 /xburst Files specific to Ingenic XBurst CPUs
169 /lib Architecture specific library files
170 /nds32 Files generic to NDS32 architecture
171 /cpu CPU specific files
172 /n1213 Files specific to Andes Technology N1213 CPUs
173 /lib Architecture specific library files
174 /nios2 Files generic to Altera NIOS2 architecture
175 /cpu CPU specific files
176 /lib Architecture specific library files
177 /openrisc Files generic to OpenRISC architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /powerpc Files generic to PowerPC architecture
181 /cpu CPU specific files
182 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
183 /mpc5xx Files specific to Freescale MPC5xx CPUs
184 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
185 /mpc8xx Files specific to Freescale MPC8xx CPUs
186 /mpc824x Files specific to Freescale MPC824x CPUs
187 /mpc8260 Files specific to Freescale MPC8260 CPUs
188 /mpc85xx Files specific to Freescale MPC85xx CPUs
189 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
190 /lib Architecture specific library files
191 /sh Files generic to SH architecture
192 /cpu CPU specific files
193 /sh2 Files specific to sh2 CPUs
194 /sh3 Files specific to sh3 CPUs
195 /sh4 Files specific to sh4 CPUs
196 /lib Architecture specific library files
197 /sparc Files generic to SPARC architecture
198 /cpu CPU specific files
199 /leon2 Files specific to Gaisler LEON2 SPARC CPU
200 /leon3 Files specific to Gaisler LEON3 SPARC CPU
201 /lib Architecture specific library files
202 /x86 Files generic to x86 architecture
203 /cpu CPU specific files
204 /lib Architecture specific library files
205 /api Machine/arch independent API for external apps
206 /board Board dependent files
207 /common Misc architecture independent functions
208 /disk Code for disk drive partition handling
209 /doc Documentation (don't expect too much)
210 /drivers Commonly used device drivers
211 /dts Contains Makefile for building internal U-Boot fdt.
212 /examples Example code for standalone applications, etc.
213 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
214 /include Header Files
215 /lib Files generic to all architectures
216 /libfdt Library files to support flattened device trees
217 /lzma Library files to support LZMA decompression
218 /lzo Library files to support LZO decompression
220 /post Power On Self Test
221 /spl Secondary Program Loader framework
222 /tools Tools to build S-Record or U-Boot images, etc.
224 Software Configuration:
225 =======================
227 Configuration is usually done using C preprocessor defines; the
228 rationale behind that is to avoid dead code whenever possible.
230 There are two classes of configuration variables:
232 * Configuration _OPTIONS_:
233 These are selectable by the user and have names beginning with
236 * Configuration _SETTINGS_:
237 These depend on the hardware etc. and should not be meddled with if
238 you don't know what you're doing; they have names beginning with
241 Later we will add a configuration tool - probably similar to or even
242 identical to what's used for the Linux kernel. Right now, we have to
243 do the configuration by hand, which means creating some symbolic
244 links and editing some configuration files. We use the TQM8xxL boards
248 Selection of Processor Architecture and Board Type:
249 ---------------------------------------------------
251 For all supported boards there are ready-to-use default
252 configurations available; just type "make <board_name>_config".
254 Example: For a TQM823L module type:
259 For the Cogent platform, you need to specify the CPU type as well;
260 e.g. "make cogent_mpc8xx_config". And also configure the cogent
261 directory according to the instructions in cogent/README.
264 Configuration Options:
265 ----------------------
267 Configuration depends on the combination of board and CPU type; all
268 such information is kept in a configuration file
269 "include/configs/<board_name>.h".
271 Example: For a TQM823L module, all configuration settings are in
272 "include/configs/TQM823L.h".
275 Many of the options are named exactly as the corresponding Linux
276 kernel configuration options. The intention is to make it easier to
277 build a config tool - later.
280 The following options need to be configured:
282 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
284 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
286 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
287 Define exactly one, e.g. CONFIG_ATSTK1002
289 - CPU Module Type: (if CONFIG_COGENT is defined)
290 Define exactly one of
292 --- FIXME --- not tested yet:
293 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
294 CONFIG_CMA287_23, CONFIG_CMA287_50
296 - Motherboard Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
298 CONFIG_CMA101, CONFIG_CMA102
300 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
301 Define one or more of
304 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
305 Define one or more of
306 CONFIG_LCD_HEARTBEAT - update a character position on
307 the LCD display every second with
310 - Board flavour: (if CONFIG_MPC8260ADS is defined)
313 CONFIG_SYS_8260ADS - original MPC8260ADS
314 CONFIG_SYS_8266ADS - MPC8266ADS
315 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
316 CONFIG_SYS_8272ADS - MPC8272ADS
318 - Marvell Family Member
319 CONFIG_SYS_MVFS - define it if you want to enable
320 multiple fs option at one time
321 for marvell soc family
323 - MPC824X Family Member (if CONFIG_MPC824X is defined)
324 Define exactly one of
325 CONFIG_MPC8240, CONFIG_MPC8245
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 requred during NOR boot.
406 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
408 This is the value to write into CCSR offset 0x18600
409 according to the A004510 workaround.
411 CONFIG_SYS_FSL_DSP_DDR_ADDR
412 This value denotes start offset of DDR memory which is
413 connected exclusively to the DSP cores.
415 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
416 This value denotes start offset of M2 memory
417 which is directly connected to the DSP core.
419 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
420 This value denotes start offset of M3 memory which is directly
421 connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
424 This value denotes start offset of DSP CCSR space.
426 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
427 Single Source Clock is clocking mode present in some of FSL SoC's.
428 In this mode, a single differential clock is used to supply
429 clocks to the sysclock, ddrclock and usbclock.
431 - Generic CPU options:
432 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
434 Defines the endianess of the CPU. Implementation of those
435 values is arch specific.
438 Freescale DDR driver in use. This type of DDR controller is
439 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
442 CONFIG_SYS_FSL_DDR_ADDR
443 Freescale DDR memory-mapped register base.
445 CONFIG_SYS_FSL_DDR_EMU
446 Specify emulator support for DDR. Some DDR features such as
447 deskew training are not available.
449 CONFIG_SYS_FSL_DDRC_GEN1
450 Freescale DDR1 controller.
452 CONFIG_SYS_FSL_DDRC_GEN2
453 Freescale DDR2 controller.
455 CONFIG_SYS_FSL_DDRC_GEN3
456 Freescale DDR3 controller.
458 CONFIG_SYS_FSL_DDRC_ARM_GEN3
459 Freescale DDR3 controller for ARM-based SoCs.
462 Board config to use DDR1. It can be enabled for SoCs with
463 Freescale DDR1 or DDR2 controllers, depending on the board
467 Board config to use DDR2. It can be eanbeld for SoCs with
468 Freescale DDR2 or DDR3 controllers, depending on the board
472 Board config to use DDR3. It can be enabled for SoCs with
473 Freescale DDR3 controllers.
475 - Intel Monahans options:
476 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
478 Defines the Monahans run mode to oscillator
479 ratio. Valid values are 8, 16, 24, 31. The core
480 frequency is this value multiplied by 13 MHz.
482 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
484 Defines the Monahans turbo mode to oscillator
485 ratio. Valid values are 1 (default if undefined) and
486 2. The core frequency as calculated above is multiplied
490 CONFIG_SYS_INIT_SP_OFFSET
492 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
493 pointer. This is needed for the temporary stack before
496 CONFIG_SYS_MIPS_CACHE_MODE
498 Cache operation mode for the MIPS CPU.
499 See also arch/mips/include/asm/mipsregs.h.
501 CONF_CM_CACHABLE_NO_WA
504 CONF_CM_CACHABLE_NONCOHERENT
508 CONF_CM_CACHABLE_ACCELERATED
510 CONFIG_SYS_XWAY_EBU_BOOTCFG
512 Special option for Lantiq XWAY SoCs for booting from NOR flash.
513 See also arch/mips/cpu/mips32/start.S.
515 CONFIG_XWAY_SWAP_BYTES
517 Enable compilation of tools/xway-swap-bytes needed for Lantiq
518 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
519 be swapped if a flash programmer is used.
522 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
524 Select high exception vectors of the ARM core, e.g., do not
525 clear the V bit of the c1 register of CP15.
527 CONFIG_SYS_THUMB_BUILD
529 Use this flag to build U-Boot using the Thumb instruction
530 set for ARM architectures. Thumb instruction set provides
531 better code density. For ARM architectures that support
532 Thumb2 this flag will result in Thumb2 code generated by
535 CONFIG_ARM_ERRATA_716044
536 CONFIG_ARM_ERRATA_742230
537 CONFIG_ARM_ERRATA_743622
538 CONFIG_ARM_ERRATA_751472
540 If set, the workarounds for these ARM errata are applied early
541 during U-Boot startup. Note that these options force the
542 workarounds to be applied; no CPU-type/version detection
543 exists, unlike the similar options in the Linux kernel. Do not
544 set these options unless they apply!
549 The frequency of the timer returned by get_timer().
550 get_timer() must operate in milliseconds and this CONFIG
551 option must be set to 1000.
553 - Linux Kernel Interface:
556 U-Boot stores all clock information in Hz
557 internally. For binary compatibility with older Linux
558 kernels (which expect the clocks passed in the
559 bd_info data to be in MHz) the environment variable
560 "clocks_in_mhz" can be defined so that U-Boot
561 converts clock data to MHZ before passing it to the
563 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
564 "clocks_in_mhz=1" is automatically included in the
567 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
569 When transferring memsize parameter to linux, some versions
570 expect it to be in bytes, others in MB.
571 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
575 New kernel versions are expecting firmware settings to be
576 passed using flattened device trees (based on open firmware
580 * New libfdt-based support
581 * Adds the "fdt" command
582 * The bootm command automatically updates the fdt
584 OF_CPU - The proper name of the cpus node (only required for
585 MPC512X and MPC5xxx based boards).
586 OF_SOC - The proper name of the soc node (only required for
587 MPC512X and MPC5xxx based boards).
588 OF_TBCLK - The timebase frequency.
589 OF_STDOUT_PATH - The path to the console device
591 boards with QUICC Engines require OF_QE to set UCC MAC
594 CONFIG_OF_BOARD_SETUP
596 Board code has addition modification that it wants to make
597 to the flat device tree before handing it off to the kernel
601 This define fills in the correct boot CPU in the boot
602 param header, the default value is zero if undefined.
606 U-Boot can detect if an IDE device is present or not.
607 If not, and this new config option is activated, U-Boot
608 removes the ATA node from the DTS before booting Linux,
609 so the Linux IDE driver does not probe the device and
610 crash. This is needed for buggy hardware (uc101) where
611 no pull down resistor is connected to the signal IDE5V_DD7.
613 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
615 This setting is mandatory for all boards that have only one
616 machine type and must be used to specify the machine type
617 number as it appears in the ARM machine registry
618 (see http://www.arm.linux.org.uk/developer/machines/).
619 Only boards that have multiple machine types supported
620 in a single configuration file and the machine type is
621 runtime discoverable, do not have to use this setting.
623 - vxWorks boot parameters:
625 bootvx constructs a valid bootline using the following
626 environments variables: bootfile, ipaddr, serverip, hostname.
627 It loads the vxWorks image pointed bootfile.
629 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
630 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
631 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
632 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
634 CONFIG_SYS_VXWORKS_ADD_PARAMS
636 Add it at the end of the bootline. E.g "u=username pw=secret"
638 Note: If a "bootargs" environment is defined, it will overwride
639 the defaults discussed just above.
641 - Cache Configuration:
642 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
643 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
644 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
646 - Cache Configuration for ARM:
647 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
649 CONFIG_SYS_PL310_BASE - Physical base address of PL310
650 controller register space
655 Define this if you want support for Amba PrimeCell PL010 UARTs.
659 Define this if you want support for Amba PrimeCell PL011 UARTs.
663 If you have Amba PrimeCell PL011 UARTs, set this variable to
664 the clock speed of the UARTs.
668 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
669 define this to a list of base addresses for each (supported)
670 port. See e.g. include/configs/versatile.h
672 CONFIG_PL011_SERIAL_RLCR
674 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
675 have separate receive and transmit line control registers. Set
676 this variable to initialize the extra register.
678 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
680 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
681 boot loader that has already initialized the UART. Define this
682 variable to flush the UART at init time.
686 Depending on board, define exactly one serial port
687 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
688 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
689 console by defining CONFIG_8xx_CONS_NONE
691 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
692 port routines must be defined elsewhere
693 (i.e. serial_init(), serial_getc(), ...)
696 Enables console device for a color framebuffer. Needs following
697 defines (cf. smiLynxEM, i8042)
698 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
700 VIDEO_HW_RECTFILL graphic chip supports
703 VIDEO_HW_BITBLT graphic chip supports
704 bit-blit (cf. smiLynxEM)
705 VIDEO_VISIBLE_COLS visible pixel columns
707 VIDEO_VISIBLE_ROWS visible pixel rows
708 VIDEO_PIXEL_SIZE bytes per pixel
709 VIDEO_DATA_FORMAT graphic data format
710 (0-5, cf. cfb_console.c)
711 VIDEO_FB_ADRS framebuffer address
712 VIDEO_KBD_INIT_FCT keyboard int fct
713 (i.e. i8042_kbd_init())
714 VIDEO_TSTC_FCT test char fct
716 VIDEO_GETC_FCT get char fct
718 CONFIG_CONSOLE_CURSOR cursor drawing on/off
719 (requires blink timer
721 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
722 CONFIG_CONSOLE_TIME display time/date info in
724 (requires CONFIG_CMD_DATE)
725 CONFIG_VIDEO_LOGO display Linux logo in
727 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
728 linux_logo.h for logo.
729 Requires CONFIG_VIDEO_LOGO
730 CONFIG_CONSOLE_EXTRA_INFO
731 additional board info beside
734 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
735 a limited number of ANSI escape sequences (cursor control,
736 erase functions and limited graphics rendition control).
738 When CONFIG_CFB_CONSOLE is defined, video console is
739 default i/o. Serial console can be forced with
740 environment 'console=serial'.
742 When CONFIG_SILENT_CONSOLE is defined, all console
743 messages (by U-Boot and Linux!) can be silenced with
744 the "silent" environment variable. See
745 doc/README.silent for more information.
747 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
749 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
753 CONFIG_BAUDRATE - in bps
754 Select one of the baudrates listed in
755 CONFIG_SYS_BAUDRATE_TABLE, see below.
756 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
758 - Console Rx buffer length
759 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
760 the maximum receive buffer length for the SMC.
761 This option is actual only for 82xx and 8xx possible.
762 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
763 must be defined, to setup the maximum idle timeout for
766 - Pre-Console Buffer:
767 Prior to the console being initialised (i.e. serial UART
768 initialised etc) all console output is silently discarded.
769 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
770 buffer any console messages prior to the console being
771 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
772 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
773 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
774 bytes are output before the console is initialised, the
775 earlier bytes are discarded.
777 'Sane' compilers will generate smaller code if
778 CONFIG_PRE_CON_BUF_SZ is a power of 2
780 - Safe printf() functions
781 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
782 the printf() functions. These are defined in
783 include/vsprintf.h and include snprintf(), vsnprintf() and
784 so on. Code size increase is approximately 300-500 bytes.
785 If this option is not given then these functions will
786 silently discard their buffer size argument - this means
787 you are not getting any overflow checking in this case.
789 - Boot Delay: CONFIG_BOOTDELAY - in seconds
790 Delay before automatically booting the default image;
791 set to -1 to disable autoboot.
792 set to -2 to autoboot with no delay and not check for abort
793 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
795 See doc/README.autoboot for these options that
796 work with CONFIG_BOOTDELAY. None are required.
797 CONFIG_BOOT_RETRY_TIME
798 CONFIG_BOOT_RETRY_MIN
799 CONFIG_AUTOBOOT_KEYED
800 CONFIG_AUTOBOOT_PROMPT
801 CONFIG_AUTOBOOT_DELAY_STR
802 CONFIG_AUTOBOOT_STOP_STR
803 CONFIG_AUTOBOOT_DELAY_STR2
804 CONFIG_AUTOBOOT_STOP_STR2
805 CONFIG_ZERO_BOOTDELAY_CHECK
806 CONFIG_RESET_TO_RETRY
810 Only needed when CONFIG_BOOTDELAY is enabled;
811 define a command string that is automatically executed
812 when no character is read on the console interface
813 within "Boot Delay" after reset.
816 This can be used to pass arguments to the bootm
817 command. The value of CONFIG_BOOTARGS goes into the
818 environment value "bootargs".
820 CONFIG_RAMBOOT and CONFIG_NFSBOOT
821 The value of these goes into the environment as
822 "ramboot" and "nfsboot" respectively, and can be used
823 as a convenience, when switching between booting from
827 CONFIG_BOOTCOUNT_LIMIT
828 Implements a mechanism for detecting a repeating reboot
830 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
833 If no softreset save registers are found on the hardware
834 "bootcount" is stored in the environment. To prevent a
835 saveenv on all reboots, the environment variable
836 "upgrade_available" is used. If "upgrade_available" is
837 0, "bootcount" is always 0, if "upgrade_available" is
838 1 "bootcount" is incremented in the environment.
839 So the Userspace Applikation must set the "upgrade_available"
840 and "bootcount" variable to 0, if a boot was successfully.
845 When this option is #defined, the existence of the
846 environment variable "preboot" will be checked
847 immediately before starting the CONFIG_BOOTDELAY
848 countdown and/or running the auto-boot command resp.
849 entering interactive mode.
851 This feature is especially useful when "preboot" is
852 automatically generated or modified. For an example
853 see the LWMON board specific code: here "preboot" is
854 modified when the user holds down a certain
855 combination of keys on the (special) keyboard when
858 - Serial Download Echo Mode:
860 If defined to 1, all characters received during a
861 serial download (using the "loads" command) are
862 echoed back. This might be needed by some terminal
863 emulations (like "cu"), but may as well just take
864 time on others. This setting #define's the initial
865 value of the "loads_echo" environment variable.
867 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
869 Select one of the baudrates listed in
870 CONFIG_SYS_BAUDRATE_TABLE, see below.
873 Monitor commands can be included or excluded
874 from the build by using the #include files
875 <config_cmd_all.h> and #undef'ing unwanted
876 commands, or using <config_cmd_default.h>
877 and augmenting with additional #define's
880 The default command configuration includes all commands
881 except those marked below with a "*".
883 CONFIG_CMD_ASKENV * ask for env variable
884 CONFIG_CMD_BDI bdinfo
885 CONFIG_CMD_BEDBUG * Include BedBug Debugger
886 CONFIG_CMD_BMP * BMP support
887 CONFIG_CMD_BSP * Board specific commands
888 CONFIG_CMD_BOOTD bootd
889 CONFIG_CMD_CACHE * icache, dcache
890 CONFIG_CMD_CONSOLE coninfo
891 CONFIG_CMD_CRC32 * crc32
892 CONFIG_CMD_DATE * support for RTC, date/time...
893 CONFIG_CMD_DHCP * DHCP support
894 CONFIG_CMD_DIAG * Diagnostics
895 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
896 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
897 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
898 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
899 CONFIG_CMD_DTT * Digital Therm and Thermostat
900 CONFIG_CMD_ECHO echo arguments
901 CONFIG_CMD_EDITENV edit env variable
902 CONFIG_CMD_EEPROM * EEPROM read/write support
903 CONFIG_CMD_ELF * bootelf, bootvx
904 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
905 CONFIG_CMD_ENV_FLAGS * display details about env flags
906 CONFIG_CMD_ENV_EXISTS * check existence of env variable
907 CONFIG_CMD_EXPORTENV * export the environment
908 CONFIG_CMD_EXT2 * ext2 command support
909 CONFIG_CMD_EXT4 * ext4 command support
910 CONFIG_CMD_SAVEENV saveenv
911 CONFIG_CMD_FDC * Floppy Disk Support
912 CONFIG_CMD_FAT * FAT command support
913 CONFIG_CMD_FDOS * Dos diskette Support
914 CONFIG_CMD_FLASH flinfo, erase, protect
915 CONFIG_CMD_FPGA FPGA device initialization support
916 CONFIG_CMD_FUSE * Device fuse support
917 CONFIG_CMD_GETTIME * Get time since boot
918 CONFIG_CMD_GO * the 'go' command (exec code)
919 CONFIG_CMD_GREPENV * search environment
920 CONFIG_CMD_HASH * calculate hash / digest
921 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
922 CONFIG_CMD_I2C * I2C serial bus support
923 CONFIG_CMD_IDE * IDE harddisk support
924 CONFIG_CMD_IMI iminfo
925 CONFIG_CMD_IMLS List all images found in NOR flash
926 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
927 CONFIG_CMD_IMMAP * IMMR dump support
928 CONFIG_CMD_IMPORTENV * import an environment
929 CONFIG_CMD_INI * import data from an ini file into the env
930 CONFIG_CMD_IRQ * irqinfo
931 CONFIG_CMD_ITEST Integer/string test of 2 values
932 CONFIG_CMD_JFFS2 * JFFS2 Support
933 CONFIG_CMD_KGDB * kgdb
934 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
935 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
937 CONFIG_CMD_LOADB loadb
938 CONFIG_CMD_LOADS loads
939 CONFIG_CMD_MD5SUM * print md5 message digest
940 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
941 CONFIG_CMD_MEMINFO * Display detailed memory information
942 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
944 CONFIG_CMD_MEMTEST * mtest
945 CONFIG_CMD_MISC Misc functions like sleep etc
946 CONFIG_CMD_MMC * MMC memory mapped support
947 CONFIG_CMD_MII * MII utility commands
948 CONFIG_CMD_MTDPARTS * MTD partition support
949 CONFIG_CMD_NAND * NAND support
950 CONFIG_CMD_NET bootp, tftpboot, rarpboot
951 CONFIG_CMD_NFS NFS support
952 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
953 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
954 CONFIG_CMD_PCI * pciinfo
955 CONFIG_CMD_PCMCIA * PCMCIA support
956 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
958 CONFIG_CMD_PORTIO * Port I/O
959 CONFIG_CMD_READ * Read raw data from partition
960 CONFIG_CMD_REGINFO * Register dump
961 CONFIG_CMD_RUN run command in env variable
962 CONFIG_CMD_SANDBOX * sb command to access sandbox features
963 CONFIG_CMD_SAVES * save S record dump
964 CONFIG_CMD_SCSI * SCSI Support
965 CONFIG_CMD_SDRAM * print SDRAM configuration information
966 (requires CONFIG_CMD_I2C)
967 CONFIG_CMD_SETGETDCR Support for DCR Register access
969 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
970 CONFIG_CMD_SHA1SUM * print sha1 memory digest
971 (requires CONFIG_CMD_MEMORY)
972 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
973 CONFIG_CMD_SOURCE "source" command Support
974 CONFIG_CMD_SPI * SPI serial bus support
975 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
976 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
977 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
978 CONFIG_CMD_TIMER * access to the system tick timer
979 CONFIG_CMD_USB * USB support
980 CONFIG_CMD_CDP * Cisco Discover Protocol support
981 CONFIG_CMD_MFSL * Microblaze FSL support
982 CONFIG_CMD_XIMG Load part of Multi Image
985 EXAMPLE: If you want all functions except of network
986 support you can write:
988 #include "config_cmd_all.h"
989 #undef CONFIG_CMD_NET
992 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
994 Note: Don't enable the "icache" and "dcache" commands
995 (configuration option CONFIG_CMD_CACHE) unless you know
996 what you (and your U-Boot users) are doing. Data
997 cache cannot be enabled on systems like the 8xx or
998 8260 (where accesses to the IMMR region must be
999 uncached), and it cannot be disabled on all other
1000 systems where we (mis-) use the data cache to hold an
1001 initial stack and some data.
1004 XXX - this list needs to get updated!
1006 - Regular expression support:
1008 If this variable is defined, U-Boot is linked against
1009 the SLRE (Super Light Regular Expression) library,
1010 which adds regex support to some commands, as for
1011 example "env grep" and "setexpr".
1015 If this variable is defined, U-Boot will use a device tree
1016 to configure its devices, instead of relying on statically
1017 compiled #defines in the board file. This option is
1018 experimental and only available on a few boards. The device
1019 tree is available in the global data as gd->fdt_blob.
1021 U-Boot needs to get its device tree from somewhere. This can
1022 be done using one of the two options below:
1025 If this variable is defined, U-Boot will embed a device tree
1026 binary in its image. This device tree file should be in the
1027 board directory and called <soc>-<board>.dts. The binary file
1028 is then picked up in board_init_f() and made available through
1029 the global data structure as gd->blob.
1032 If this variable is defined, U-Boot will build a device tree
1033 binary. It will be called u-boot.dtb. Architecture-specific
1034 code will locate it at run-time. Generally this works by:
1036 cat u-boot.bin u-boot.dtb >image.bin
1038 and in fact, U-Boot does this for you, creating a file called
1039 u-boot-dtb.bin which is useful in the common case. You can
1040 still use the individual files if you need something more
1045 If this variable is defined, it enables watchdog
1046 support for the SoC. There must be support in the SoC
1047 specific code for a watchdog. For the 8xx and 8260
1048 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1049 register. When supported for a specific SoC is
1050 available, then no further board specific code should
1051 be needed to use it.
1054 When using a watchdog circuitry external to the used
1055 SoC, then define this variable and provide board
1056 specific code for the "hw_watchdog_reset" function.
1059 CONFIG_VERSION_VARIABLE
1060 If this variable is defined, an environment variable
1061 named "ver" is created by U-Boot showing the U-Boot
1062 version as printed by the "version" command.
1063 Any change to this variable will be reverted at the
1068 When CONFIG_CMD_DATE is selected, the type of the RTC
1069 has to be selected, too. Define exactly one of the
1072 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1073 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1074 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1075 CONFIG_RTC_MC146818 - use MC146818 RTC
1076 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1077 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1078 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1079 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1080 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1081 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1082 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1083 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1086 Note that if the RTC uses I2C, then the I2C interface
1087 must also be configured. See I2C Support, below.
1090 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1092 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1093 chip-ngpio pairs that tell the PCA953X driver the number of
1094 pins supported by a particular chip.
1096 Note that if the GPIO device uses I2C, then the I2C interface
1097 must also be configured. See I2C Support, below.
1099 - Timestamp Support:
1101 When CONFIG_TIMESTAMP is selected, the timestamp
1102 (date and time) of an image is printed by image
1103 commands like bootm or iminfo. This option is
1104 automatically enabled when you select CONFIG_CMD_DATE .
1106 - Partition Labels (disklabels) Supported:
1107 Zero or more of the following:
1108 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1109 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1110 Intel architecture, USB sticks, etc.
1111 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1112 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1113 bootloader. Note 2TB partition limit; see
1115 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1117 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1118 CONFIG_CMD_SCSI) you must configure support for at
1119 least one non-MTD partition type as well.
1122 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1123 board configurations files but used nowhere!
1125 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1126 be performed by calling the function
1127 ide_set_reset(int reset)
1128 which has to be defined in a board specific file
1133 Set this to enable ATAPI support.
1138 Set this to enable support for disks larger than 137GB
1139 Also look at CONFIG_SYS_64BIT_LBA.
1140 Whithout these , LBA48 support uses 32bit variables and will 'only'
1141 support disks up to 2.1TB.
1143 CONFIG_SYS_64BIT_LBA:
1144 When enabled, makes the IDE subsystem use 64bit sector addresses.
1148 At the moment only there is only support for the
1149 SYM53C8XX SCSI controller; define
1150 CONFIG_SCSI_SYM53C8XX to enable it.
1152 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1153 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1154 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1155 maximum numbers of LUNs, SCSI ID's and target
1157 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1159 The environment variable 'scsidevs' is set to the number of
1160 SCSI devices found during the last scan.
1162 - NETWORK Support (PCI):
1164 Support for Intel 8254x/8257x gigabit chips.
1167 Utility code for direct access to the SPI bus on Intel 8257x.
1168 This does not do anything useful unless you set at least one
1169 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1171 CONFIG_E1000_SPI_GENERIC
1172 Allow generic access to the SPI bus on the Intel 8257x, for
1173 example with the "sspi" command.
1176 Management command for E1000 devices. When used on devices
1177 with SPI support you can reprogram the EEPROM from U-Boot.
1179 CONFIG_E1000_FALLBACK_MAC
1180 default MAC for empty EEPROM after production.
1183 Support for Intel 82557/82559/82559ER chips.
1184 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1185 write routine for first time initialisation.
1188 Support for Digital 2114x chips.
1189 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1190 modem chip initialisation (KS8761/QS6611).
1193 Support for National dp83815 chips.
1196 Support for National dp8382[01] gigabit chips.
1198 - NETWORK Support (other):
1200 CONFIG_DRIVER_AT91EMAC
1201 Support for AT91RM9200 EMAC.
1204 Define this to use reduced MII inteface
1206 CONFIG_DRIVER_AT91EMAC_QUIET
1207 If this defined, the driver is quiet.
1208 The driver doen't show link status messages.
1210 CONFIG_CALXEDA_XGMAC
1211 Support for the Calxeda XGMAC device
1214 Support for SMSC's LAN91C96 chips.
1216 CONFIG_LAN91C96_BASE
1217 Define this to hold the physical address
1218 of the LAN91C96's I/O space
1220 CONFIG_LAN91C96_USE_32_BIT
1221 Define this to enable 32 bit addressing
1224 Support for SMSC's LAN91C111 chip
1226 CONFIG_SMC91111_BASE
1227 Define this to hold the physical address
1228 of the device (I/O space)
1230 CONFIG_SMC_USE_32_BIT
1231 Define this if data bus is 32 bits
1233 CONFIG_SMC_USE_IOFUNCS
1234 Define this to use i/o functions instead of macros
1235 (some hardware wont work with macros)
1237 CONFIG_DRIVER_TI_EMAC
1238 Support for davinci emac
1240 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1241 Define this if you have more then 3 PHYs.
1244 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1246 CONFIG_FTGMAC100_EGIGA
1247 Define this to use GE link update with gigabit PHY.
1248 Define this if FTGMAC100 is connected to gigabit PHY.
1249 If your system has 10/100 PHY only, it might not occur
1250 wrong behavior. Because PHY usually return timeout or
1251 useless data when polling gigabit status and gigabit
1252 control registers. This behavior won't affect the
1253 correctnessof 10/100 link speed update.
1256 Support for SMSC's LAN911x and LAN921x chips
1259 Define this to hold the physical address
1260 of the device (I/O space)
1262 CONFIG_SMC911X_32_BIT
1263 Define this if data bus is 32 bits
1265 CONFIG_SMC911X_16_BIT
1266 Define this if data bus is 16 bits. If your processor
1267 automatically converts one 32 bit word to two 16 bit
1268 words you may also try CONFIG_SMC911X_32_BIT.
1271 Support for Renesas on-chip Ethernet controller
1273 CONFIG_SH_ETHER_USE_PORT
1274 Define the number of ports to be used
1276 CONFIG_SH_ETHER_PHY_ADDR
1277 Define the ETH PHY's address
1279 CONFIG_SH_ETHER_CACHE_WRITEBACK
1280 If this option is set, the driver enables cache flush.
1284 Support TPM devices.
1287 Support for i2c bus TPM devices. Only one device
1288 per system is supported at this time.
1290 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1291 Define the the i2c bus number for the TPM device
1293 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1294 Define the TPM's address on the i2c bus
1296 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1297 Define the burst count bytes upper limit
1299 CONFIG_TPM_ATMEL_TWI
1300 Support for Atmel TWI TPM device. Requires I2C support.
1303 Support for generic parallel port TPM devices. Only one device
1304 per system is supported at this time.
1306 CONFIG_TPM_TIS_BASE_ADDRESS
1307 Base address where the generic TPM device is mapped
1308 to. Contemporary x86 systems usually map it at
1312 Add tpm monitor functions.
1313 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1314 provides monitor access to authorized functions.
1317 Define this to enable the TPM support library which provides
1318 functional interfaces to some TPM commands.
1319 Requires support for a TPM device.
1321 CONFIG_TPM_AUTH_SESSIONS
1322 Define this to enable authorized functions in the TPM library.
1323 Requires CONFIG_TPM and CONFIG_SHA1.
1326 At the moment only the UHCI host controller is
1327 supported (PIP405, MIP405, MPC5200); define
1328 CONFIG_USB_UHCI to enable it.
1329 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1330 and define CONFIG_USB_STORAGE to enable the USB
1333 Supported are USB Keyboards and USB Floppy drives
1335 MPC5200 USB requires additional defines:
1337 for 528 MHz Clock: 0x0001bbbb
1341 for differential drivers: 0x00001000
1342 for single ended drivers: 0x00005000
1343 for differential drivers on PSC3: 0x00000100
1344 for single ended drivers on PSC3: 0x00004100
1345 CONFIG_SYS_USB_EVENT_POLL
1346 May be defined to allow interrupt polling
1347 instead of using asynchronous interrupts
1349 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1350 txfilltuning field in the EHCI controller on reset.
1352 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1353 interval for usb hub power-on delay.(minimum 100msec)
1356 Define the below if you wish to use the USB console.
1357 Once firmware is rebuilt from a serial console issue the
1358 command "setenv stdin usbtty; setenv stdout usbtty" and
1359 attach your USB cable. The Unix command "dmesg" should print
1360 it has found a new device. The environment variable usbtty
1361 can be set to gserial or cdc_acm to enable your device to
1362 appear to a USB host as a Linux gserial device or a
1363 Common Device Class Abstract Control Model serial device.
1364 If you select usbtty = gserial you should be able to enumerate
1366 # modprobe usbserial vendor=0xVendorID product=0xProductID
1367 else if using cdc_acm, simply setting the environment
1368 variable usbtty to be cdc_acm should suffice. The following
1369 might be defined in YourBoardName.h
1372 Define this to build a UDC device
1375 Define this to have a tty type of device available to
1376 talk to the UDC device
1379 Define this to enable the high speed support for usb
1380 device and usbtty. If this feature is enabled, a routine
1381 int is_usbd_high_speed(void)
1382 also needs to be defined by the driver to dynamically poll
1383 whether the enumeration has succeded at high speed or full
1386 CONFIG_SYS_CONSOLE_IS_IN_ENV
1387 Define this if you want stdin, stdout &/or stderr to
1391 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1392 Derive USB clock from external clock "blah"
1393 - CONFIG_SYS_USB_EXTC_CLK 0x02
1395 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1396 Derive USB clock from brgclk
1397 - CONFIG_SYS_USB_BRG_CLK 0x04
1399 If you have a USB-IF assigned VendorID then you may wish to
1400 define your own vendor specific values either in BoardName.h
1401 or directly in usbd_vendor_info.h. If you don't define
1402 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1403 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1404 should pretend to be a Linux device to it's target host.
1406 CONFIG_USBD_MANUFACTURER
1407 Define this string as the name of your company for
1408 - CONFIG_USBD_MANUFACTURER "my company"
1410 CONFIG_USBD_PRODUCT_NAME
1411 Define this string as the name of your product
1412 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1414 CONFIG_USBD_VENDORID
1415 Define this as your assigned Vendor ID from the USB
1416 Implementors Forum. This *must* be a genuine Vendor ID
1417 to avoid polluting the USB namespace.
1418 - CONFIG_USBD_VENDORID 0xFFFF
1420 CONFIG_USBD_PRODUCTID
1421 Define this as the unique Product ID
1423 - CONFIG_USBD_PRODUCTID 0xFFFF
1425 Some USB device drivers may need to check USB cable attachment.
1426 In this case you can enable following config in BoardName.h:
1427 CONFIG_USB_CABLE_CHECK
1428 This enables function definition:
1429 - usb_cable_connected() in include/usb.h
1430 Implementation of this function is board-specific.
1432 - ULPI Layer Support:
1433 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1434 the generic ULPI layer. The generic layer accesses the ULPI PHY
1435 via the platform viewport, so you need both the genric layer and
1436 the viewport enabled. Currently only Chipidea/ARC based
1437 viewport is supported.
1438 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1439 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1440 If your ULPI phy needs a different reference clock than the
1441 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1442 the appropriate value in Hz.
1445 The MMC controller on the Intel PXA is supported. To
1446 enable this define CONFIG_MMC. The MMC can be
1447 accessed from the boot prompt by mapping the device
1448 to physical memory similar to flash. Command line is
1449 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1450 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1453 Support for Renesas on-chip MMCIF controller
1455 CONFIG_SH_MMCIF_ADDR
1456 Define the base address of MMCIF registers
1459 Define the clock frequency for MMCIF
1461 - USB Device Firmware Update (DFU) class support:
1463 This enables the USB portion of the DFU USB class
1466 This enables the command "dfu" which is used to have
1467 U-Boot create a DFU class device via USB. This command
1468 requires that the "dfu_alt_info" environment variable be
1469 set and define the alt settings to expose to the host.
1472 This enables support for exposing (e)MMC devices via DFU.
1475 This enables support for exposing NAND devices via DFU.
1478 This enables support for exposing RAM via DFU.
1479 Note: DFU spec refer to non-volatile memory usage, but
1480 allow usages beyond the scope of spec - here RAM usage,
1481 one that would help mostly the developer.
1483 CONFIG_SYS_DFU_DATA_BUF_SIZE
1484 Dfu transfer uses a buffer before writing data to the
1485 raw storage device. Make the size (in bytes) of this buffer
1486 configurable. The size of this buffer is also configurable
1487 through the "dfu_bufsiz" environment variable.
1489 CONFIG_SYS_DFU_MAX_FILE_SIZE
1490 When updating files rather than the raw storage device,
1491 we use a static buffer to copy the file into and then write
1492 the buffer once we've been given the whole file. Define
1493 this to the maximum filesize (in bytes) for the buffer.
1494 Default is 4 MiB if undefined.
1496 - Journaling Flash filesystem support:
1497 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1498 CONFIG_JFFS2_NAND_DEV
1499 Define these for a default partition on a NAND device
1501 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1502 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1503 Define these for a default partition on a NOR device
1505 CONFIG_SYS_JFFS_CUSTOM_PART
1506 Define this to create an own partition. You have to provide a
1507 function struct part_info* jffs2_part_info(int part_num)
1509 If you define only one JFFS2 partition you may also want to
1510 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1511 to disable the command chpart. This is the default when you
1512 have not defined a custom partition
1514 - FAT(File Allocation Table) filesystem write function support:
1517 Define this to enable support for saving memory data as a
1518 file in FAT formatted partition.
1520 This will also enable the command "fatwrite" enabling the
1521 user to write files to FAT.
1523 CBFS (Coreboot Filesystem) support
1526 Define this to enable support for reading from a Coreboot
1527 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1533 Define this to enable standard (PC-Style) keyboard
1537 Standard PC keyboard driver with US (is default) and
1538 GERMAN key layout (switch via environment 'keymap=de') support.
1539 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1540 for cfb_console. Supports cursor blinking.
1543 Enables a Chrome OS keyboard using the CROS_EC interface.
1544 This uses CROS_EC to communicate with a second microcontroller
1545 which provides key scans on request.
1550 Define this to enable video support (for output to
1553 CONFIG_VIDEO_CT69000
1555 Enable Chips & Technologies 69000 Video chip
1557 CONFIG_VIDEO_SMI_LYNXEM
1558 Enable Silicon Motion SMI 712/710/810 Video chip. The
1559 video output is selected via environment 'videoout'
1560 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1563 For the CT69000 and SMI_LYNXEM drivers, videomode is
1564 selected via environment 'videomode'. Two different ways
1566 - "videomode=num" 'num' is a standard LiLo mode numbers.
1567 Following standard modes are supported (* is default):
1569 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1570 -------------+---------------------------------------------
1571 8 bits | 0x301* 0x303 0x305 0x161 0x307
1572 15 bits | 0x310 0x313 0x316 0x162 0x319
1573 16 bits | 0x311 0x314 0x317 0x163 0x31A
1574 24 bits | 0x312 0x315 0x318 ? 0x31B
1575 -------------+---------------------------------------------
1576 (i.e. setenv videomode 317; saveenv; reset;)
1578 - "videomode=bootargs" all the video parameters are parsed
1579 from the bootargs. (See drivers/video/videomodes.c)
1582 CONFIG_VIDEO_SED13806
1583 Enable Epson SED13806 driver. This driver supports 8bpp
1584 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1585 or CONFIG_VIDEO_SED13806_16BPP
1588 Enable the Freescale DIU video driver. Reference boards for
1589 SOCs that have a DIU should define this macro to enable DIU
1590 support, and should also define these other macros:
1596 CONFIG_VIDEO_SW_CURSOR
1597 CONFIG_VGA_AS_SINGLE_DEVICE
1599 CONFIG_VIDEO_BMP_LOGO
1601 The DIU driver will look for the 'video-mode' environment
1602 variable, and if defined, enable the DIU as a console during
1603 boot. See the documentation file README.video for a
1604 description of this variable.
1608 Enable the VGA video / BIOS for x86. The alternative if you
1609 are using coreboot is to use the coreboot frame buffer
1616 Define this to enable a custom keyboard support.
1617 This simply calls drv_keyboard_init() which must be
1618 defined in your board-specific files.
1619 The only board using this so far is RBC823.
1621 - LCD Support: CONFIG_LCD
1623 Define this to enable LCD support (for output to LCD
1624 display); also select one of the supported displays
1625 by defining one of these:
1629 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1631 CONFIG_NEC_NL6448AC33:
1633 NEC NL6448AC33-18. Active, color, single scan.
1635 CONFIG_NEC_NL6448BC20
1637 NEC NL6448BC20-08. 6.5", 640x480.
1638 Active, color, single scan.
1640 CONFIG_NEC_NL6448BC33_54
1642 NEC NL6448BC33-54. 10.4", 640x480.
1643 Active, color, single scan.
1647 Sharp 320x240. Active, color, single scan.
1648 It isn't 16x9, and I am not sure what it is.
1650 CONFIG_SHARP_LQ64D341
1652 Sharp LQ64D341 display, 640x480.
1653 Active, color, single scan.
1657 HLD1045 display, 640x480.
1658 Active, color, single scan.
1662 Optrex CBL50840-2 NF-FW 99 22 M5
1664 Hitachi LMG6912RPFC-00T
1668 320x240. Black & white.
1670 Normally display is black on white background; define
1671 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1673 CONFIG_LCD_ALIGNMENT
1675 Normally the LCD is page-aligned (tyically 4KB). If this is
1676 defined then the LCD will be aligned to this value instead.
1677 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1678 here, since it is cheaper to change data cache settings on
1679 a per-section basis.
1681 CONFIG_CONSOLE_SCROLL_LINES
1683 When the console need to be scrolled, this is the number of
1684 lines to scroll by. It defaults to 1. Increasing this makes
1685 the console jump but can help speed up operation when scrolling
1690 Support drawing of RLE8-compressed bitmaps on the LCD.
1694 Enables an 'i2c edid' command which can read EDID
1695 information over I2C from an attached LCD display.
1697 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1699 If this option is set, the environment is checked for
1700 a variable "splashimage". If found, the usual display
1701 of logo, copyright and system information on the LCD
1702 is suppressed and the BMP image at the address
1703 specified in "splashimage" is loaded instead. The
1704 console is redirected to the "nulldev", too. This
1705 allows for a "silent" boot where a splash screen is
1706 loaded very quickly after power-on.
1708 CONFIG_SPLASHIMAGE_GUARD
1710 If this option is set, then U-Boot will prevent the environment
1711 variable "splashimage" from being set to a problematic address
1712 (see README.displaying-bmps and README.arm-unaligned-accesses).
1713 This option is useful for targets where, due to alignment
1714 restrictions, an improperly aligned BMP image will cause a data
1715 abort. If you think you will not have problems with unaligned
1716 accesses (for example because your toolchain prevents them)
1717 there is no need to set this option.
1719 CONFIG_SPLASH_SCREEN_ALIGN
1721 If this option is set the splash image can be freely positioned
1722 on the screen. Environment variable "splashpos" specifies the
1723 position as "x,y". If a positive number is given it is used as
1724 number of pixel from left/top. If a negative number is given it
1725 is used as number of pixel from right/bottom. You can also
1726 specify 'm' for centering the image.
1729 setenv splashpos m,m
1730 => image at center of screen
1732 setenv splashpos 30,20
1733 => image at x = 30 and y = 20
1735 setenv splashpos -10,m
1736 => vertically centered image
1737 at x = dspWidth - bmpWidth - 9
1739 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1741 If this option is set, additionally to standard BMP
1742 images, gzipped BMP images can be displayed via the
1743 splashscreen support or the bmp command.
1745 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1747 If this option is set, 8-bit RLE compressed BMP images
1748 can be displayed via the splashscreen support or the
1751 - Do compresssing for memory range:
1754 If this option is set, it would use zlib deflate method
1755 to compress the specified memory at its best effort.
1757 - Compression support:
1760 Enabled by default to support gzip compressed images.
1764 If this option is set, support for bzip2 compressed
1765 images is included. If not, only uncompressed and gzip
1766 compressed images are supported.
1768 NOTE: the bzip2 algorithm requires a lot of RAM, so
1769 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1774 If this option is set, support for lzma compressed
1777 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1778 requires an amount of dynamic memory that is given by the
1781 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1783 Where lc and lp stand for, respectively, Literal context bits
1784 and Literal pos bits.
1786 This value is upper-bounded by 14MB in the worst case. Anyway,
1787 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1788 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1789 a very small buffer.
1791 Use the lzmainfo tool to determinate the lc and lp values and
1792 then calculate the amount of needed dynamic memory (ensuring
1793 the appropriate CONFIG_SYS_MALLOC_LEN value).
1797 If this option is set, support for LZO compressed images
1803 The address of PHY on MII bus.
1805 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1807 The clock frequency of the MII bus
1811 If this option is set, support for speed/duplex
1812 detection of gigabit PHY is included.
1814 CONFIG_PHY_RESET_DELAY
1816 Some PHY like Intel LXT971A need extra delay after
1817 reset before any MII register access is possible.
1818 For such PHY, set this option to the usec delay
1819 required. (minimum 300usec for LXT971A)
1821 CONFIG_PHY_CMD_DELAY (ppc4xx)
1823 Some PHY like Intel LXT971A need extra delay after
1824 command issued before MII status register can be read
1834 Define a default value for Ethernet address to use
1835 for the respective Ethernet interface, in case this
1836 is not determined automatically.
1841 Define a default value for the IP address to use for
1842 the default Ethernet interface, in case this is not
1843 determined through e.g. bootp.
1844 (Environment variable "ipaddr")
1846 - Server IP address:
1849 Defines a default value for the IP address of a TFTP
1850 server to contact when using the "tftboot" command.
1851 (Environment variable "serverip")
1853 CONFIG_KEEP_SERVERADDR
1855 Keeps the server's MAC address, in the env 'serveraddr'
1856 for passing to bootargs (like Linux's netconsole option)
1858 - Gateway IP address:
1861 Defines a default value for the IP address of the
1862 default router where packets to other networks are
1864 (Environment variable "gatewayip")
1869 Defines a default value for the subnet mask (or
1870 routing prefix) which is used to determine if an IP
1871 address belongs to the local subnet or needs to be
1872 forwarded through a router.
1873 (Environment variable "netmask")
1875 - Multicast TFTP Mode:
1878 Defines whether you want to support multicast TFTP as per
1879 rfc-2090; for example to work with atftp. Lets lots of targets
1880 tftp down the same boot image concurrently. Note: the Ethernet
1881 driver in use must provide a function: mcast() to join/leave a
1884 - BOOTP Recovery Mode:
1885 CONFIG_BOOTP_RANDOM_DELAY
1887 If you have many targets in a network that try to
1888 boot using BOOTP, you may want to avoid that all
1889 systems send out BOOTP requests at precisely the same
1890 moment (which would happen for instance at recovery
1891 from a power failure, when all systems will try to
1892 boot, thus flooding the BOOTP server. Defining
1893 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1894 inserted before sending out BOOTP requests. The
1895 following delays are inserted then:
1897 1st BOOTP request: delay 0 ... 1 sec
1898 2nd BOOTP request: delay 0 ... 2 sec
1899 3rd BOOTP request: delay 0 ... 4 sec
1901 BOOTP requests: delay 0 ... 8 sec
1903 - DHCP Advanced Options:
1904 You can fine tune the DHCP functionality by defining
1905 CONFIG_BOOTP_* symbols:
1907 CONFIG_BOOTP_SUBNETMASK
1908 CONFIG_BOOTP_GATEWAY
1909 CONFIG_BOOTP_HOSTNAME
1910 CONFIG_BOOTP_NISDOMAIN
1911 CONFIG_BOOTP_BOOTPATH
1912 CONFIG_BOOTP_BOOTFILESIZE
1915 CONFIG_BOOTP_SEND_HOSTNAME
1916 CONFIG_BOOTP_NTPSERVER
1917 CONFIG_BOOTP_TIMEOFFSET
1918 CONFIG_BOOTP_VENDOREX
1919 CONFIG_BOOTP_MAY_FAIL
1921 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1922 environment variable, not the BOOTP server.
1924 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1925 after the configured retry count, the call will fail
1926 instead of starting over. This can be used to fail over
1927 to Link-local IP address configuration if the DHCP server
1930 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1931 serverip from a DHCP server, it is possible that more
1932 than one DNS serverip is offered to the client.
1933 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1934 serverip will be stored in the additional environment
1935 variable "dnsip2". The first DNS serverip is always
1936 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1939 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1940 to do a dynamic update of a DNS server. To do this, they
1941 need the hostname of the DHCP requester.
1942 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1943 of the "hostname" environment variable is passed as
1944 option 12 to the DHCP server.
1946 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1948 A 32bit value in microseconds for a delay between
1949 receiving a "DHCP Offer" and sending the "DHCP Request".
1950 This fixes a problem with certain DHCP servers that don't
1951 respond 100% of the time to a "DHCP request". E.g. On an
1952 AT91RM9200 processor running at 180MHz, this delay needed
1953 to be *at least* 15,000 usec before a Windows Server 2003
1954 DHCP server would reply 100% of the time. I recommend at
1955 least 50,000 usec to be safe. The alternative is to hope
1956 that one of the retries will be successful but note that
1957 the DHCP timeout and retry process takes a longer than
1960 - Link-local IP address negotiation:
1961 Negotiate with other link-local clients on the local network
1962 for an address that doesn't require explicit configuration.
1963 This is especially useful if a DHCP server cannot be guaranteed
1964 to exist in all environments that the device must operate.
1966 See doc/README.link-local for more information.
1969 CONFIG_CDP_DEVICE_ID
1971 The device id used in CDP trigger frames.
1973 CONFIG_CDP_DEVICE_ID_PREFIX
1975 A two character string which is prefixed to the MAC address
1980 A printf format string which contains the ascii name of
1981 the port. Normally is set to "eth%d" which sets
1982 eth0 for the first Ethernet, eth1 for the second etc.
1984 CONFIG_CDP_CAPABILITIES
1986 A 32bit integer which indicates the device capabilities;
1987 0x00000010 for a normal host which does not forwards.
1991 An ascii string containing the version of the software.
1995 An ascii string containing the name of the platform.
1999 A 32bit integer sent on the trigger.
2001 CONFIG_CDP_POWER_CONSUMPTION
2003 A 16bit integer containing the power consumption of the
2004 device in .1 of milliwatts.
2006 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2008 A byte containing the id of the VLAN.
2010 - Status LED: CONFIG_STATUS_LED
2012 Several configurations allow to display the current
2013 status using a LED. For instance, the LED will blink
2014 fast while running U-Boot code, stop blinking as
2015 soon as a reply to a BOOTP request was received, and
2016 start blinking slow once the Linux kernel is running
2017 (supported by a status LED driver in the Linux
2018 kernel). Defining CONFIG_STATUS_LED enables this
2024 The status LED can be connected to a GPIO pin.
2025 In such cases, the gpio_led driver can be used as a
2026 status LED backend implementation. Define CONFIG_GPIO_LED
2027 to include the gpio_led driver in the U-Boot binary.
2029 CONFIG_GPIO_LED_INVERTED_TABLE
2030 Some GPIO connected LEDs may have inverted polarity in which
2031 case the GPIO high value corresponds to LED off state and
2032 GPIO low value corresponds to LED on state.
2033 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2034 with a list of GPIO LEDs that have inverted polarity.
2036 - CAN Support: CONFIG_CAN_DRIVER
2038 Defining CONFIG_CAN_DRIVER enables CAN driver support
2039 on those systems that support this (optional)
2040 feature, like the TQM8xxL modules.
2042 - I2C Support: CONFIG_SYS_I2C
2044 This enable the NEW i2c subsystem, and will allow you to use
2045 i2c commands at the u-boot command line (as long as you set
2046 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2047 based realtime clock chips or other i2c devices. See
2048 common/cmd_i2c.c for a description of the command line
2051 ported i2c driver to the new framework:
2052 - drivers/i2c/soft_i2c.c:
2053 - activate first bus with CONFIG_SYS_I2C_SOFT define
2054 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2055 for defining speed and slave address
2056 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2057 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2058 for defining speed and slave address
2059 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2060 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2061 for defining speed and slave address
2062 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2063 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2064 for defining speed and slave address
2066 - drivers/i2c/fsl_i2c.c:
2067 - activate i2c driver with CONFIG_SYS_I2C_FSL
2068 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2069 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2070 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2072 - If your board supports a second fsl i2c bus, define
2073 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2074 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2075 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2078 - drivers/i2c/tegra_i2c.c:
2079 - activate this driver with CONFIG_SYS_I2C_TEGRA
2080 - This driver adds 4 i2c buses with a fix speed from
2081 100000 and the slave addr 0!
2083 - drivers/i2c/ppc4xx_i2c.c
2084 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2085 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2086 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2088 - drivers/i2c/i2c_mxc.c
2089 - activate this driver with CONFIG_SYS_I2C_MXC
2090 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2091 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2092 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2093 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2094 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2095 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2096 If thoses defines are not set, default value is 100000
2097 for speed, and 0 for slave.
2099 - drivers/i2c/rcar_i2c.c:
2100 - activate this driver with CONFIG_SYS_I2C_RCAR
2101 - This driver adds 4 i2c buses
2103 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2104 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2105 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2106 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2107 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2108 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2109 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2110 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2111 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2113 - drivers/i2c/sh_i2c.c:
2114 - activate this driver with CONFIG_SYS_I2C_SH
2115 - This driver adds from 2 to 5 i2c buses
2117 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2118 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2119 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2120 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2121 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2122 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2123 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2124 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2125 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2126 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2127 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2128 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2129 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2131 - drivers/i2c/omap24xx_i2c.c
2132 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2133 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2134 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2135 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2136 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2137 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2138 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2139 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2140 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2141 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2142 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2144 - drivers/i2c/zynq_i2c.c
2145 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2146 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2147 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2149 - drivers/i2c/s3c24x0_i2c.c:
2150 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2151 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2152 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2153 with a fix speed from 100000 and the slave addr 0!
2157 CONFIG_SYS_NUM_I2C_BUSES
2158 Hold the number of i2c busses you want to use. If you
2159 don't use/have i2c muxes on your i2c bus, this
2160 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2163 CONFIG_SYS_I2C_DIRECT_BUS
2164 define this, if you don't use i2c muxes on your hardware.
2165 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2168 CONFIG_SYS_I2C_MAX_HOPS
2169 define how many muxes are maximal consecutively connected
2170 on one i2c bus. If you not use i2c muxes, omit this
2173 CONFIG_SYS_I2C_BUSES
2174 hold a list of busses you want to use, only used if
2175 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2176 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2177 CONFIG_SYS_NUM_I2C_BUSES = 9:
2179 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2180 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2181 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2182 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2183 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2184 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2185 {1, {I2C_NULL_HOP}}, \
2186 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2187 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2191 bus 0 on adapter 0 without a mux
2192 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2193 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2194 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2195 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2196 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2197 bus 6 on adapter 1 without a mux
2198 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2199 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2201 If you do not have i2c muxes on your board, omit this define.
2203 - Legacy I2C Support: CONFIG_HARD_I2C
2205 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2206 provides the following compelling advantages:
2208 - more than one i2c adapter is usable
2209 - approved multibus support
2210 - better i2c mux support
2212 ** Please consider updating your I2C driver now. **
2214 These enable legacy I2C serial bus commands. Defining
2215 CONFIG_HARD_I2C will include the appropriate I2C driver
2216 for the selected CPU.
2218 This will allow you to use i2c commands at the u-boot
2219 command line (as long as you set CONFIG_CMD_I2C in
2220 CONFIG_COMMANDS) and communicate with i2c based realtime
2221 clock chips. See common/cmd_i2c.c for a description of the
2222 command line interface.
2224 CONFIG_HARD_I2C selects a hardware I2C controller.
2226 There are several other quantities that must also be
2227 defined when you define CONFIG_HARD_I2C.
2229 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2230 to be the frequency (in Hz) at which you wish your i2c bus
2231 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2232 the CPU's i2c node address).
2234 Now, the u-boot i2c code for the mpc8xx
2235 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2236 and so its address should therefore be cleared to 0 (See,
2237 eg, MPC823e User's Manual p.16-473). So, set
2238 CONFIG_SYS_I2C_SLAVE to 0.
2240 CONFIG_SYS_I2C_INIT_MPC5XXX
2242 When a board is reset during an i2c bus transfer
2243 chips might think that the current transfer is still
2244 in progress. Reset the slave devices by sending start
2245 commands until the slave device responds.
2247 That's all that's required for CONFIG_HARD_I2C.
2249 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2250 then the following macros need to be defined (examples are
2251 from include/configs/lwmon.h):
2255 (Optional). Any commands necessary to enable the I2C
2256 controller or configure ports.
2258 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2262 (Only for MPC8260 CPU). The I/O port to use (the code
2263 assumes both bits are on the same port). Valid values
2264 are 0..3 for ports A..D.
2268 The code necessary to make the I2C data line active
2269 (driven). If the data line is open collector, this
2272 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2276 The code necessary to make the I2C data line tri-stated
2277 (inactive). If the data line is open collector, this
2280 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2284 Code that returns true if the I2C data line is high,
2287 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2291 If <bit> is true, sets the I2C data line high. If it
2292 is false, it clears it (low).
2294 eg: #define I2C_SDA(bit) \
2295 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2296 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2300 If <bit> is true, sets the I2C clock line high. If it
2301 is false, it clears it (low).
2303 eg: #define I2C_SCL(bit) \
2304 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2305 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2309 This delay is invoked four times per clock cycle so this
2310 controls the rate of data transfer. The data rate thus
2311 is 1 / (I2C_DELAY * 4). Often defined to be something
2314 #define I2C_DELAY udelay(2)
2316 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2318 If your arch supports the generic GPIO framework (asm/gpio.h),
2319 then you may alternatively define the two GPIOs that are to be
2320 used as SCL / SDA. Any of the previous I2C_xxx macros will
2321 have GPIO-based defaults assigned to them as appropriate.
2323 You should define these to the GPIO value as given directly to
2324 the generic GPIO functions.
2326 CONFIG_SYS_I2C_INIT_BOARD
2328 When a board is reset during an i2c bus transfer
2329 chips might think that the current transfer is still
2330 in progress. On some boards it is possible to access
2331 the i2c SCLK line directly, either by using the
2332 processor pin as a GPIO or by having a second pin
2333 connected to the bus. If this option is defined a
2334 custom i2c_init_board() routine in boards/xxx/board.c
2335 is run early in the boot sequence.
2337 CONFIG_SYS_I2C_BOARD_LATE_INIT
2339 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2340 defined a custom i2c_board_late_init() routine in
2341 boards/xxx/board.c is run AFTER the operations in i2c_init()
2342 is completed. This callpoint can be used to unreset i2c bus
2343 using CPU i2c controller register accesses for CPUs whose i2c
2344 controller provide such a method. It is called at the end of
2345 i2c_init() to allow i2c_init operations to setup the i2c bus
2346 controller on the CPU (e.g. setting bus speed & slave address).
2348 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2350 This option enables configuration of bi_iic_fast[] flags
2351 in u-boot bd_info structure based on u-boot environment
2352 variable "i2cfast". (see also i2cfast)
2354 CONFIG_I2C_MULTI_BUS
2356 This option allows the use of multiple I2C buses, each of which
2357 must have a controller. At any point in time, only one bus is
2358 active. To switch to a different bus, use the 'i2c dev' command.
2359 Note that bus numbering is zero-based.
2361 CONFIG_SYS_I2C_NOPROBES
2363 This option specifies a list of I2C devices that will be skipped
2364 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2365 is set, specify a list of bus-device pairs. Otherwise, specify
2366 a 1D array of device addresses
2369 #undef CONFIG_I2C_MULTI_BUS
2370 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2372 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2374 #define CONFIG_I2C_MULTI_BUS
2375 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2377 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2379 CONFIG_SYS_SPD_BUS_NUM
2381 If defined, then this indicates the I2C bus number for DDR SPD.
2382 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2384 CONFIG_SYS_RTC_BUS_NUM
2386 If defined, then this indicates the I2C bus number for the RTC.
2387 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2389 CONFIG_SYS_DTT_BUS_NUM
2391 If defined, then this indicates the I2C bus number for the DTT.
2392 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2394 CONFIG_SYS_I2C_DTT_ADDR:
2396 If defined, specifies the I2C address of the DTT device.
2397 If not defined, then U-Boot uses predefined value for
2398 specified DTT device.
2400 CONFIG_SOFT_I2C_READ_REPEATED_START
2402 defining this will force the i2c_read() function in
2403 the soft_i2c driver to perform an I2C repeated start
2404 between writing the address pointer and reading the
2405 data. If this define is omitted the default behaviour
2406 of doing a stop-start sequence will be used. Most I2C
2407 devices can use either method, but some require one or
2410 - SPI Support: CONFIG_SPI
2412 Enables SPI driver (so far only tested with
2413 SPI EEPROM, also an instance works with Crystal A/D and
2414 D/As on the SACSng board)
2418 Enables the driver for SPI controller on SuperH. Currently
2419 only SH7757 is supported.
2423 Enables extended (16-bit) SPI EEPROM addressing.
2424 (symmetrical to CONFIG_I2C_X)
2428 Enables a software (bit-bang) SPI driver rather than
2429 using hardware support. This is a general purpose
2430 driver that only requires three general I/O port pins
2431 (two outputs, one input) to function. If this is
2432 defined, the board configuration must define several
2433 SPI configuration items (port pins to use, etc). For
2434 an example, see include/configs/sacsng.h.
2438 Enables a hardware SPI driver for general-purpose reads
2439 and writes. As with CONFIG_SOFT_SPI, the board configuration
2440 must define a list of chip-select function pointers.
2441 Currently supported on some MPC8xxx processors. For an
2442 example, see include/configs/mpc8349emds.h.
2446 Enables the driver for the SPI controllers on i.MX and MXC
2447 SoCs. Currently i.MX31/35/51 are supported.
2449 - FPGA Support: CONFIG_FPGA
2451 Enables FPGA subsystem.
2453 CONFIG_FPGA_<vendor>
2455 Enables support for specific chip vendors.
2458 CONFIG_FPGA_<family>
2460 Enables support for FPGA family.
2461 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2465 Specify the number of FPGA devices to support.
2467 CONFIG_SYS_FPGA_PROG_FEEDBACK
2469 Enable printing of hash marks during FPGA configuration.
2471 CONFIG_SYS_FPGA_CHECK_BUSY
2473 Enable checks on FPGA configuration interface busy
2474 status by the configuration function. This option
2475 will require a board or device specific function to
2480 If defined, a function that provides delays in the FPGA
2481 configuration driver.
2483 CONFIG_SYS_FPGA_CHECK_CTRLC
2484 Allow Control-C to interrupt FPGA configuration
2486 CONFIG_SYS_FPGA_CHECK_ERROR
2488 Check for configuration errors during FPGA bitfile
2489 loading. For example, abort during Virtex II
2490 configuration if the INIT_B line goes low (which
2491 indicated a CRC error).
2493 CONFIG_SYS_FPGA_WAIT_INIT
2495 Maximum time to wait for the INIT_B line to deassert
2496 after PROB_B has been deasserted during a Virtex II
2497 FPGA configuration sequence. The default time is 500
2500 CONFIG_SYS_FPGA_WAIT_BUSY
2502 Maximum time to wait for BUSY to deassert during
2503 Virtex II FPGA configuration. The default is 5 ms.
2505 CONFIG_SYS_FPGA_WAIT_CONFIG
2507 Time to wait after FPGA configuration. The default is
2510 - Configuration Management:
2513 If defined, this string will be added to the U-Boot
2514 version information (U_BOOT_VERSION)
2516 - Vendor Parameter Protection:
2518 U-Boot considers the values of the environment
2519 variables "serial#" (Board Serial Number) and
2520 "ethaddr" (Ethernet Address) to be parameters that
2521 are set once by the board vendor / manufacturer, and
2522 protects these variables from casual modification by
2523 the user. Once set, these variables are read-only,
2524 and write or delete attempts are rejected. You can
2525 change this behaviour:
2527 If CONFIG_ENV_OVERWRITE is #defined in your config
2528 file, the write protection for vendor parameters is
2529 completely disabled. Anybody can change or delete
2532 Alternatively, if you #define _both_ CONFIG_ETHADDR
2533 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2534 Ethernet address is installed in the environment,
2535 which can be changed exactly ONCE by the user. [The
2536 serial# is unaffected by this, i. e. it remains
2539 The same can be accomplished in a more flexible way
2540 for any variable by configuring the type of access
2541 to allow for those variables in the ".flags" variable
2542 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2547 Define this variable to enable the reservation of
2548 "protected RAM", i. e. RAM which is not overwritten
2549 by U-Boot. Define CONFIG_PRAM to hold the number of
2550 kB you want to reserve for pRAM. You can overwrite
2551 this default value by defining an environment
2552 variable "pram" to the number of kB you want to
2553 reserve. Note that the board info structure will
2554 still show the full amount of RAM. If pRAM is
2555 reserved, a new environment variable "mem" will
2556 automatically be defined to hold the amount of
2557 remaining RAM in a form that can be passed as boot
2558 argument to Linux, for instance like that:
2560 setenv bootargs ... mem=\${mem}
2563 This way you can tell Linux not to use this memory,
2564 either, which results in a memory region that will
2565 not be affected by reboots.
2567 *WARNING* If your board configuration uses automatic
2568 detection of the RAM size, you must make sure that
2569 this memory test is non-destructive. So far, the
2570 following board configurations are known to be
2573 IVMS8, IVML24, SPD8xx, TQM8xxL,
2574 HERMES, IP860, RPXlite, LWMON,
2577 - Access to physical memory region (> 4GB)
2578 Some basic support is provided for operations on memory not
2579 normally accessible to U-Boot - e.g. some architectures
2580 support access to more than 4GB of memory on 32-bit
2581 machines using physical address extension or similar.
2582 Define CONFIG_PHYSMEM to access this basic support, which
2583 currently only supports clearing the memory.
2588 Define this variable to stop the system in case of a
2589 fatal error, so that you have to reset it manually.
2590 This is probably NOT a good idea for an embedded
2591 system where you want the system to reboot
2592 automatically as fast as possible, but it may be
2593 useful during development since you can try to debug
2594 the conditions that lead to the situation.
2596 CONFIG_NET_RETRY_COUNT
2598 This variable defines the number of retries for
2599 network operations like ARP, RARP, TFTP, or BOOTP
2600 before giving up the operation. If not defined, a
2601 default value of 5 is used.
2605 Timeout waiting for an ARP reply in milliseconds.
2609 Timeout in milliseconds used in NFS protocol.
2610 If you encounter "ERROR: Cannot umount" in nfs command,
2611 try longer timeout such as
2612 #define CONFIG_NFS_TIMEOUT 10000UL
2614 - Command Interpreter:
2615 CONFIG_AUTO_COMPLETE
2617 Enable auto completion of commands using TAB.
2619 Note that this feature has NOT been implemented yet
2620 for the "hush" shell.
2623 CONFIG_SYS_HUSH_PARSER
2625 Define this variable to enable the "hush" shell (from
2626 Busybox) as command line interpreter, thus enabling
2627 powerful command line syntax like
2628 if...then...else...fi conditionals or `&&' and '||'
2629 constructs ("shell scripts").
2631 If undefined, you get the old, much simpler behaviour
2632 with a somewhat smaller memory footprint.
2635 CONFIG_SYS_PROMPT_HUSH_PS2
2637 This defines the secondary prompt string, which is
2638 printed when the command interpreter needs more input
2639 to complete a command. Usually "> ".
2643 In the current implementation, the local variables
2644 space and global environment variables space are
2645 separated. Local variables are those you define by
2646 simply typing `name=value'. To access a local
2647 variable later on, you have write `$name' or
2648 `${name}'; to execute the contents of a variable
2649 directly type `$name' at the command prompt.
2651 Global environment variables are those you use
2652 setenv/printenv to work with. To run a command stored
2653 in such a variable, you need to use the run command,
2654 and you must not use the '$' sign to access them.
2656 To store commands and special characters in a
2657 variable, please use double quotation marks
2658 surrounding the whole text of the variable, instead
2659 of the backslashes before semicolons and special
2662 - Commandline Editing and History:
2663 CONFIG_CMDLINE_EDITING
2665 Enable editing and History functions for interactive
2666 commandline input operations
2668 - Default Environment:
2669 CONFIG_EXTRA_ENV_SETTINGS
2671 Define this to contain any number of null terminated
2672 strings (variable = value pairs) that will be part of
2673 the default environment compiled into the boot image.
2675 For example, place something like this in your
2676 board's config file:
2678 #define CONFIG_EXTRA_ENV_SETTINGS \
2682 Warning: This method is based on knowledge about the
2683 internal format how the environment is stored by the
2684 U-Boot code. This is NOT an official, exported
2685 interface! Although it is unlikely that this format
2686 will change soon, there is no guarantee either.
2687 You better know what you are doing here.
2689 Note: overly (ab)use of the default environment is
2690 discouraged. Make sure to check other ways to preset
2691 the environment like the "source" command or the
2694 CONFIG_ENV_VARS_UBOOT_CONFIG
2696 Define this in order to add variables describing the
2697 U-Boot build configuration to the default environment.
2698 These will be named arch, cpu, board, vendor, and soc.
2700 Enabling this option will cause the following to be defined:
2708 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2710 Define this in order to add variables describing certain
2711 run-time determined information about the hardware to the
2712 environment. These will be named board_name, board_rev.
2714 CONFIG_DELAY_ENVIRONMENT
2716 Normally the environment is loaded when the board is
2717 intialised so that it is available to U-Boot. This inhibits
2718 that so that the environment is not available until
2719 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2720 this is instead controlled by the value of
2721 /config/load-environment.
2723 - DataFlash Support:
2724 CONFIG_HAS_DATAFLASH
2726 Defining this option enables DataFlash features and
2727 allows to read/write in Dataflash via the standard
2730 - Serial Flash support
2733 Defining this option enables SPI flash commands
2734 'sf probe/read/write/erase/update'.
2736 Usage requires an initial 'probe' to define the serial
2737 flash parameters, followed by read/write/erase/update
2740 The following defaults may be provided by the platform
2741 to handle the common case when only a single serial
2742 flash is present on the system.
2744 CONFIG_SF_DEFAULT_BUS Bus identifier
2745 CONFIG_SF_DEFAULT_CS Chip-select
2746 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2747 CONFIG_SF_DEFAULT_SPEED in Hz
2751 Define this option to include a destructive SPI flash
2754 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2756 Define this option to use the Bank addr/Extended addr
2757 support on SPI flashes which has size > 16Mbytes.
2759 - SystemACE Support:
2762 Adding this option adds support for Xilinx SystemACE
2763 chips attached via some sort of local bus. The address
2764 of the chip must also be defined in the
2765 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2767 #define CONFIG_SYSTEMACE
2768 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2770 When SystemACE support is added, the "ace" device type
2771 becomes available to the fat commands, i.e. fatls.
2773 - TFTP Fixed UDP Port:
2776 If this is defined, the environment variable tftpsrcp
2777 is used to supply the TFTP UDP source port value.
2778 If tftpsrcp isn't defined, the normal pseudo-random port
2779 number generator is used.
2781 Also, the environment variable tftpdstp is used to supply
2782 the TFTP UDP destination port value. If tftpdstp isn't
2783 defined, the normal port 69 is used.
2785 The purpose for tftpsrcp is to allow a TFTP server to
2786 blindly start the TFTP transfer using the pre-configured
2787 target IP address and UDP port. This has the effect of
2788 "punching through" the (Windows XP) firewall, allowing
2789 the remainder of the TFTP transfer to proceed normally.
2790 A better solution is to properly configure the firewall,
2791 but sometimes that is not allowed.
2796 This enables a generic 'hash' command which can produce
2797 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2801 Enable the hash verify command (hash -v). This adds to code
2804 CONFIG_SHA1 - support SHA1 hashing
2805 CONFIG_SHA256 - support SHA256 hashing
2807 Note: There is also a sha1sum command, which should perhaps
2808 be deprecated in favour of 'hash sha1'.
2810 - Freescale i.MX specific commands:
2811 CONFIG_CMD_HDMIDETECT
2812 This enables 'hdmidet' command which returns true if an
2813 HDMI monitor is detected. This command is i.MX 6 specific.
2816 This enables the 'bmode' (bootmode) command for forcing
2817 a boot from specific media.
2819 This is useful for forcing the ROM's usb downloader to
2820 activate upon a watchdog reset which is nice when iterating
2821 on U-Boot. Using the reset button or running bmode normal
2822 will set it back to normal. This command currently
2823 supports i.MX53 and i.MX6.
2828 This enables the RSA algorithm used for FIT image verification
2829 in U-Boot. See doc/uImage/signature for more information.
2831 The signing part is build into mkimage regardless of this
2835 - Show boot progress:
2836 CONFIG_SHOW_BOOT_PROGRESS
2838 Defining this option allows to add some board-
2839 specific code (calling a user-provided function
2840 "show_boot_progress(int)") that enables you to show
2841 the system's boot progress on some display (for
2842 example, some LED's) on your board. At the moment,
2843 the following checkpoints are implemented:
2845 - Detailed boot stage timing
2847 Define this option to get detailed timing of each stage
2848 of the boot process.
2850 CONFIG_BOOTSTAGE_USER_COUNT
2851 This is the number of available user bootstage records.
2852 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2853 a new ID will be allocated from this stash. If you exceed
2854 the limit, recording will stop.
2856 CONFIG_BOOTSTAGE_REPORT
2857 Define this to print a report before boot, similar to this:
2859 Timer summary in microseconds:
2862 3,575,678 3,575,678 board_init_f start
2863 3,575,695 17 arch_cpu_init A9
2864 3,575,777 82 arch_cpu_init done
2865 3,659,598 83,821 board_init_r start
2866 3,910,375 250,777 main_loop
2867 29,916,167 26,005,792 bootm_start
2868 30,361,327 445,160 start_kernel
2870 CONFIG_CMD_BOOTSTAGE
2871 Add a 'bootstage' command which supports printing a report
2872 and un/stashing of bootstage data.
2874 CONFIG_BOOTSTAGE_FDT
2875 Stash the bootstage information in the FDT. A root 'bootstage'
2876 node is created with each bootstage id as a child. Each child
2877 has a 'name' property and either 'mark' containing the
2878 mark time in microsecond, or 'accum' containing the
2879 accumulated time for that bootstage id in microseconds.
2884 name = "board_init_f";
2893 Code in the Linux kernel can find this in /proc/devicetree.
2895 Legacy uImage format:
2898 1 common/cmd_bootm.c before attempting to boot an image
2899 -1 common/cmd_bootm.c Image header has bad magic number
2900 2 common/cmd_bootm.c Image header has correct magic number
2901 -2 common/cmd_bootm.c Image header has bad checksum
2902 3 common/cmd_bootm.c Image header has correct checksum
2903 -3 common/cmd_bootm.c Image data has bad checksum
2904 4 common/cmd_bootm.c Image data has correct checksum
2905 -4 common/cmd_bootm.c Image is for unsupported architecture
2906 5 common/cmd_bootm.c Architecture check OK
2907 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2908 6 common/cmd_bootm.c Image Type check OK
2909 -6 common/cmd_bootm.c gunzip uncompression error
2910 -7 common/cmd_bootm.c Unimplemented compression type
2911 7 common/cmd_bootm.c Uncompression OK
2912 8 common/cmd_bootm.c No uncompress/copy overwrite error
2913 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2915 9 common/image.c Start initial ramdisk verification
2916 -10 common/image.c Ramdisk header has bad magic number
2917 -11 common/image.c Ramdisk header has bad checksum
2918 10 common/image.c Ramdisk header is OK
2919 -12 common/image.c Ramdisk data has bad checksum
2920 11 common/image.c Ramdisk data has correct checksum
2921 12 common/image.c Ramdisk verification complete, start loading
2922 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2923 13 common/image.c Start multifile image verification
2924 14 common/image.c No initial ramdisk, no multifile, continue.
2926 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2928 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2929 -31 post/post.c POST test failed, detected by post_output_backlog()
2930 -32 post/post.c POST test failed, detected by post_run_single()
2932 34 common/cmd_doc.c before loading a Image from a DOC device
2933 -35 common/cmd_doc.c Bad usage of "doc" command
2934 35 common/cmd_doc.c correct usage of "doc" command
2935 -36 common/cmd_doc.c No boot device
2936 36 common/cmd_doc.c correct boot device
2937 -37 common/cmd_doc.c Unknown Chip ID on boot device
2938 37 common/cmd_doc.c correct chip ID found, device available
2939 -38 common/cmd_doc.c Read Error on boot device
2940 38 common/cmd_doc.c reading Image header from DOC device OK
2941 -39 common/cmd_doc.c Image header has bad magic number
2942 39 common/cmd_doc.c Image header has correct magic number
2943 -40 common/cmd_doc.c Error reading Image from DOC device
2944 40 common/cmd_doc.c Image header has correct magic number
2945 41 common/cmd_ide.c before loading a Image from a IDE device
2946 -42 common/cmd_ide.c Bad usage of "ide" command
2947 42 common/cmd_ide.c correct usage of "ide" command
2948 -43 common/cmd_ide.c No boot device
2949 43 common/cmd_ide.c boot device found
2950 -44 common/cmd_ide.c Device not available
2951 44 common/cmd_ide.c Device available
2952 -45 common/cmd_ide.c wrong partition selected
2953 45 common/cmd_ide.c partition selected
2954 -46 common/cmd_ide.c Unknown partition table
2955 46 common/cmd_ide.c valid partition table found
2956 -47 common/cmd_ide.c Invalid partition type
2957 47 common/cmd_ide.c correct partition type
2958 -48 common/cmd_ide.c Error reading Image Header on boot device
2959 48 common/cmd_ide.c reading Image Header from IDE device OK
2960 -49 common/cmd_ide.c Image header has bad magic number
2961 49 common/cmd_ide.c Image header has correct magic number
2962 -50 common/cmd_ide.c Image header has bad checksum
2963 50 common/cmd_ide.c Image header has correct checksum
2964 -51 common/cmd_ide.c Error reading Image from IDE device
2965 51 common/cmd_ide.c reading Image from IDE device OK
2966 52 common/cmd_nand.c before loading a Image from a NAND device
2967 -53 common/cmd_nand.c Bad usage of "nand" command
2968 53 common/cmd_nand.c correct usage of "nand" command
2969 -54 common/cmd_nand.c No boot device
2970 54 common/cmd_nand.c boot device found
2971 -55 common/cmd_nand.c Unknown Chip ID on boot device
2972 55 common/cmd_nand.c correct chip ID found, device available
2973 -56 common/cmd_nand.c Error reading Image Header on boot device
2974 56 common/cmd_nand.c reading Image Header from NAND device OK
2975 -57 common/cmd_nand.c Image header has bad magic number
2976 57 common/cmd_nand.c Image header has correct magic number
2977 -58 common/cmd_nand.c Error reading Image from NAND device
2978 58 common/cmd_nand.c reading Image from NAND device OK
2980 -60 common/env_common.c Environment has a bad CRC, using default
2982 64 net/eth.c starting with Ethernet configuration.
2983 -64 net/eth.c no Ethernet found.
2984 65 net/eth.c Ethernet found.
2986 -80 common/cmd_net.c usage wrong
2987 80 common/cmd_net.c before calling NetLoop()
2988 -81 common/cmd_net.c some error in NetLoop() occurred
2989 81 common/cmd_net.c NetLoop() back without error
2990 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2991 82 common/cmd_net.c trying automatic boot
2992 83 common/cmd_net.c running "source" command
2993 -83 common/cmd_net.c some error in automatic boot or "source" command
2994 84 common/cmd_net.c end without errors
2999 100 common/cmd_bootm.c Kernel FIT Image has correct format
3000 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3001 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3002 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3003 102 common/cmd_bootm.c Kernel unit name specified
3004 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3005 103 common/cmd_bootm.c Found configuration node
3006 104 common/cmd_bootm.c Got kernel subimage node offset
3007 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3008 105 common/cmd_bootm.c Kernel subimage hash verification OK
3009 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3010 106 common/cmd_bootm.c Architecture check OK
3011 -106 common/cmd_bootm.c Kernel subimage has wrong type
3012 107 common/cmd_bootm.c Kernel subimage type OK
3013 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3014 108 common/cmd_bootm.c Got kernel subimage data/size
3015 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3016 -109 common/cmd_bootm.c Can't get kernel subimage type
3017 -110 common/cmd_bootm.c Can't get kernel subimage comp
3018 -111 common/cmd_bootm.c Can't get kernel subimage os
3019 -112 common/cmd_bootm.c Can't get kernel subimage load address
3020 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3022 120 common/image.c Start initial ramdisk verification
3023 -120 common/image.c Ramdisk FIT image has incorrect format
3024 121 common/image.c Ramdisk FIT image has correct format
3025 122 common/image.c No ramdisk subimage unit name, using configuration
3026 -122 common/image.c Can't get configuration for ramdisk subimage
3027 123 common/image.c Ramdisk unit name specified
3028 -124 common/image.c Can't get ramdisk subimage node offset
3029 125 common/image.c Got ramdisk subimage node offset
3030 -125 common/image.c Ramdisk subimage hash verification failed
3031 126 common/image.c Ramdisk subimage hash verification OK
3032 -126 common/image.c Ramdisk subimage for unsupported architecture
3033 127 common/image.c Architecture check OK
3034 -127 common/image.c Can't get ramdisk subimage data/size
3035 128 common/image.c Got ramdisk subimage data/size
3036 129 common/image.c Can't get ramdisk load address
3037 -129 common/image.c Got ramdisk load address
3039 -130 common/cmd_doc.c Incorrect FIT image format
3040 131 common/cmd_doc.c FIT image format OK
3042 -140 common/cmd_ide.c Incorrect FIT image format
3043 141 common/cmd_ide.c FIT image format OK
3045 -150 common/cmd_nand.c Incorrect FIT image format
3046 151 common/cmd_nand.c FIT image format OK
3048 - FIT image support:
3050 Enable support for the FIT uImage format.
3052 CONFIG_FIT_BEST_MATCH
3053 When no configuration is explicitly selected, default to the
3054 one whose fdt's compatibility field best matches that of
3055 U-Boot itself. A match is considered "best" if it matches the
3056 most specific compatibility entry of U-Boot's fdt's root node.
3057 The order of entries in the configuration's fdt is ignored.
3059 CONFIG_FIT_SIGNATURE
3060 This option enables signature verification of FIT uImages,
3061 using a hash signed and verified using RSA. See
3062 doc/uImage.FIT/signature.txt for more details.
3064 - Standalone program support:
3065 CONFIG_STANDALONE_LOAD_ADDR
3067 This option defines a board specific value for the
3068 address where standalone program gets loaded, thus
3069 overwriting the architecture dependent default
3072 - Frame Buffer Address:
3075 Define CONFIG_FB_ADDR if you want to use specific
3076 address for frame buffer. This is typically the case
3077 when using a graphics controller has separate video
3078 memory. U-Boot will then place the frame buffer at
3079 the given address instead of dynamically reserving it
3080 in system RAM by calling lcd_setmem(), which grabs
3081 the memory for the frame buffer depending on the
3082 configured panel size.
3084 Please see board_init_f function.
3086 - Automatic software updates via TFTP server
3088 CONFIG_UPDATE_TFTP_CNT_MAX
3089 CONFIG_UPDATE_TFTP_MSEC_MAX
3091 These options enable and control the auto-update feature;
3092 for a more detailed description refer to doc/README.update.
3094 - MTD Support (mtdparts command, UBI support)
3097 Adds the MTD device infrastructure from the Linux kernel.
3098 Needed for mtdparts command support.
3100 CONFIG_MTD_PARTITIONS
3102 Adds the MTD partitioning infrastructure from the Linux
3103 kernel. Needed for UBI support.
3108 Adds commands for interacting with MTD partitions formatted
3109 with the UBI flash translation layer
3111 Requires also defining CONFIG_RBTREE
3113 CONFIG_UBI_SILENCE_MSG
3115 Make the verbose messages from UBI stop printing. This leaves
3116 warnings and errors enabled.
3121 Adds commands for interacting with UBI volumes formatted as
3122 UBIFS. UBIFS is read-only in u-boot.
3124 Requires UBI support as well as CONFIG_LZO
3126 CONFIG_UBIFS_SILENCE_MSG
3128 Make the verbose messages from UBIFS stop printing. This leaves
3129 warnings and errors enabled.
3133 Enable building of SPL globally.
3136 LDSCRIPT for linking the SPL binary.
3138 CONFIG_SPL_MAX_FOOTPRINT
3139 Maximum size in memory allocated to the SPL, BSS included.
3140 When defined, the linker checks that the actual memory
3141 used by SPL from _start to __bss_end does not exceed it.
3142 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3143 must not be both defined at the same time.
3146 Maximum size of the SPL image (text, data, rodata, and
3147 linker lists sections), BSS excluded.
3148 When defined, the linker checks that the actual size does
3151 CONFIG_SPL_TEXT_BASE
3152 TEXT_BASE for linking the SPL binary.
3154 CONFIG_SPL_RELOC_TEXT_BASE
3155 Address to relocate to. If unspecified, this is equal to
3156 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3158 CONFIG_SPL_BSS_START_ADDR
3159 Link address for the BSS within the SPL binary.
3161 CONFIG_SPL_BSS_MAX_SIZE
3162 Maximum size in memory allocated to the SPL BSS.
3163 When defined, the linker checks that the actual memory used
3164 by SPL from __bss_start to __bss_end does not exceed it.
3165 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3166 must not be both defined at the same time.
3169 Adress of the start of the stack SPL will use
3171 CONFIG_SPL_RELOC_STACK
3172 Adress of the start of the stack SPL will use after
3173 relocation. If unspecified, this is equal to
3176 CONFIG_SYS_SPL_MALLOC_START
3177 Starting address of the malloc pool used in SPL.
3179 CONFIG_SYS_SPL_MALLOC_SIZE
3180 The size of the malloc pool used in SPL.
3182 CONFIG_SPL_FRAMEWORK
3183 Enable the SPL framework under common/. This framework
3184 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3185 NAND loading of the Linux Kernel.
3187 CONFIG_SPL_DISPLAY_PRINT
3188 For ARM, enable an optional function to print more information
3189 about the running system.
3191 CONFIG_SPL_INIT_MINIMAL
3192 Arch init code should be built for a very small image
3194 CONFIG_SPL_LIBCOMMON_SUPPORT
3195 Support for common/libcommon.o in SPL binary
3197 CONFIG_SPL_LIBDISK_SUPPORT
3198 Support for disk/libdisk.o in SPL binary
3200 CONFIG_SPL_I2C_SUPPORT
3201 Support for drivers/i2c/libi2c.o in SPL binary
3203 CONFIG_SPL_GPIO_SUPPORT
3204 Support for drivers/gpio/libgpio.o in SPL binary
3206 CONFIG_SPL_MMC_SUPPORT
3207 Support for drivers/mmc/libmmc.o in SPL binary
3209 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3210 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3211 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3212 Address, size and partition on the MMC to load U-Boot from
3213 when the MMC is being used in raw mode.
3215 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3216 Sector to load kernel uImage from when MMC is being
3217 used in raw mode (for Falcon mode)
3219 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3220 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3221 Sector and number of sectors to load kernel argument
3222 parameters from when MMC is being used in raw mode
3225 CONFIG_SPL_FAT_SUPPORT
3226 Support for fs/fat/libfat.o in SPL binary
3228 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3229 Filename to read to load U-Boot when reading from FAT
3231 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3232 Filename to read to load kernel uImage when reading
3233 from FAT (for Falcon mode)
3235 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3236 Filename to read to load kernel argument parameters
3237 when reading from FAT (for Falcon mode)
3239 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3240 Set this for NAND SPL on PPC mpc83xx targets, so that
3241 start.S waits for the rest of the SPL to load before
3242 continuing (the hardware starts execution after just
3243 loading the first page rather than the full 4K).
3245 CONFIG_SPL_NAND_BASE
3246 Include nand_base.c in the SPL. Requires
3247 CONFIG_SPL_NAND_DRIVERS.
3249 CONFIG_SPL_NAND_DRIVERS
3250 SPL uses normal NAND drivers, not minimal drivers.
3253 Include standard software ECC in the SPL
3255 CONFIG_SPL_NAND_SIMPLE
3256 Support for NAND boot using simple NAND drivers that
3257 expose the cmd_ctrl() interface.
3259 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3260 Set for the SPL on PPC mpc8xxx targets, support for
3261 drivers/ddr/fsl/libddr.o in SPL binary.
3263 CONFIG_SPL_COMMON_INIT_DDR
3264 Set for common ddr init with serial presence detect in
3267 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3268 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3269 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3270 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3271 CONFIG_SYS_NAND_ECCBYTES
3272 Defines the size and behavior of the NAND that SPL uses
3275 CONFIG_SPL_NAND_BOOT
3276 Add support NAND boot
3278 CONFIG_SYS_NAND_U_BOOT_OFFS
3279 Location in NAND to read U-Boot from
3281 CONFIG_SYS_NAND_U_BOOT_DST
3282 Location in memory to load U-Boot to
3284 CONFIG_SYS_NAND_U_BOOT_SIZE
3285 Size of image to load
3287 CONFIG_SYS_NAND_U_BOOT_START
3288 Entry point in loaded image to jump to
3290 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3291 Define this if you need to first read the OOB and then the
3292 data. This is used for example on davinci plattforms.
3294 CONFIG_SPL_OMAP3_ID_NAND
3295 Support for an OMAP3-specific set of functions to return the
3296 ID and MFR of the first attached NAND chip, if present.
3298 CONFIG_SPL_SERIAL_SUPPORT
3299 Support for drivers/serial/libserial.o in SPL binary
3301 CONFIG_SPL_SPI_FLASH_SUPPORT
3302 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3304 CONFIG_SPL_SPI_SUPPORT
3305 Support for drivers/spi/libspi.o in SPL binary
3307 CONFIG_SPL_RAM_DEVICE
3308 Support for running image already present in ram, in SPL binary
3310 CONFIG_SPL_LIBGENERIC_SUPPORT
3311 Support for lib/libgeneric.o in SPL binary
3313 CONFIG_SPL_ENV_SUPPORT
3314 Support for the environment operating in SPL binary
3316 CONFIG_SPL_NET_SUPPORT
3317 Support for the net/libnet.o in SPL binary.
3318 It conflicts with SPL env from storage medium specified by
3319 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3322 Image offset to which the SPL should be padded before appending
3323 the SPL payload. By default, this is defined as
3324 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3325 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3326 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3329 Final target image containing SPL and payload. Some SPLs
3330 use an arch-specific makefile fragment instead, for
3331 example if more than one image needs to be produced.
3333 CONFIG_FIT_SPL_PRINT
3334 Printing information about a FIT image adds quite a bit of
3335 code to SPL. So this is normally disabled in SPL. Use this
3336 option to re-enable it. This will affect the output of the
3337 bootm command when booting a FIT image.
3341 Enable building of TPL globally.
3344 Image offset to which the TPL should be padded before appending
3345 the TPL payload. By default, this is defined as
3346 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3347 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3348 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3353 [so far only for SMDK2400 boards]
3355 - Modem support enable:
3356 CONFIG_MODEM_SUPPORT
3358 - RTS/CTS Flow control enable:
3361 - Modem debug support:
3362 CONFIG_MODEM_SUPPORT_DEBUG
3364 Enables debugging stuff (char screen[1024], dbg())
3365 for modem support. Useful only with BDI2000.
3367 - Interrupt support (PPC):
3369 There are common interrupt_init() and timer_interrupt()
3370 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3371 for CPU specific initialization. interrupt_init_cpu()
3372 should set decrementer_count to appropriate value. If
3373 CPU resets decrementer automatically after interrupt
3374 (ppc4xx) it should set decrementer_count to zero.
3375 timer_interrupt() calls timer_interrupt_cpu() for CPU
3376 specific handling. If board has watchdog / status_led
3377 / other_activity_monitor it works automatically from
3378 general timer_interrupt().
3382 In the target system modem support is enabled when a
3383 specific key (key combination) is pressed during
3384 power-on. Otherwise U-Boot will boot normally
3385 (autoboot). The key_pressed() function is called from
3386 board_init(). Currently key_pressed() is a dummy
3387 function, returning 1 and thus enabling modem
3390 If there are no modem init strings in the
3391 environment, U-Boot proceed to autoboot; the
3392 previous output (banner, info printfs) will be
3395 See also: doc/README.Modem
3397 Board initialization settings:
3398 ------------------------------
3400 During Initialization u-boot calls a number of board specific functions
3401 to allow the preparation of board specific prerequisites, e.g. pin setup
3402 before drivers are initialized. To enable these callbacks the
3403 following configuration macros have to be defined. Currently this is
3404 architecture specific, so please check arch/your_architecture/lib/board.c
3405 typically in board_init_f() and board_init_r().
3407 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3408 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3409 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3410 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3412 Configuration Settings:
3413 -----------------------
3415 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3416 undefine this when you're short of memory.
3418 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3419 width of the commands listed in the 'help' command output.
3421 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3422 prompt for user input.
3424 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3426 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3428 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3430 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3431 the application (usually a Linux kernel) when it is
3434 - CONFIG_SYS_BAUDRATE_TABLE:
3435 List of legal baudrate settings for this board.
3437 - CONFIG_SYS_CONSOLE_INFO_QUIET
3438 Suppress display of console information at boot.
3440 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3441 If the board specific function
3442 extern int overwrite_console (void);
3443 returns 1, the stdin, stderr and stdout are switched to the
3444 serial port, else the settings in the environment are used.
3446 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3447 Enable the call to overwrite_console().
3449 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3450 Enable overwrite of previous console environment settings.
3452 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3453 Begin and End addresses of the area used by the
3456 - CONFIG_SYS_ALT_MEMTEST:
3457 Enable an alternate, more extensive memory test.
3459 - CONFIG_SYS_MEMTEST_SCRATCH:
3460 Scratch address used by the alternate memory test
3461 You only need to set this if address zero isn't writeable
3463 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3464 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3465 this specified memory area will get subtracted from the top
3466 (end) of RAM and won't get "touched" at all by U-Boot. By
3467 fixing up gd->ram_size the Linux kernel should gets passed
3468 the now "corrected" memory size and won't touch it either.
3469 This should work for arch/ppc and arch/powerpc. Only Linux
3470 board ports in arch/powerpc with bootwrapper support that
3471 recalculate the memory size from the SDRAM controller setup
3472 will have to get fixed in Linux additionally.
3474 This option can be used as a workaround for the 440EPx/GRx
3475 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3478 WARNING: Please make sure that this value is a multiple of
3479 the Linux page size (normally 4k). If this is not the case,
3480 then the end address of the Linux memory will be located at a
3481 non page size aligned address and this could cause major
3484 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3485 Enable temporary baudrate change while serial download
3487 - CONFIG_SYS_SDRAM_BASE:
3488 Physical start address of SDRAM. _Must_ be 0 here.
3490 - CONFIG_SYS_MBIO_BASE:
3491 Physical start address of Motherboard I/O (if using a
3494 - CONFIG_SYS_FLASH_BASE:
3495 Physical start address of Flash memory.
3497 - CONFIG_SYS_MONITOR_BASE:
3498 Physical start address of boot monitor code (set by
3499 make config files to be same as the text base address
3500 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3501 CONFIG_SYS_FLASH_BASE when booting from flash.
3503 - CONFIG_SYS_MONITOR_LEN:
3504 Size of memory reserved for monitor code, used to
3505 determine _at_compile_time_ (!) if the environment is
3506 embedded within the U-Boot image, or in a separate
3509 - CONFIG_SYS_MALLOC_LEN:
3510 Size of DRAM reserved for malloc() use.
3512 - CONFIG_SYS_BOOTM_LEN:
3513 Normally compressed uImages are limited to an
3514 uncompressed size of 8 MBytes. If this is not enough,
3515 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3516 to adjust this setting to your needs.
3518 - CONFIG_SYS_BOOTMAPSZ:
3519 Maximum size of memory mapped by the startup code of
3520 the Linux kernel; all data that must be processed by
3521 the Linux kernel (bd_info, boot arguments, FDT blob if
3522 used) must be put below this limit, unless "bootm_low"
3523 environment variable is defined and non-zero. In such case
3524 all data for the Linux kernel must be between "bootm_low"
3525 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3526 variable "bootm_mapsize" will override the value of
3527 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3528 then the value in "bootm_size" will be used instead.
3530 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3531 Enable initrd_high functionality. If defined then the
3532 initrd_high feature is enabled and the bootm ramdisk subcommand
3535 - CONFIG_SYS_BOOT_GET_CMDLINE:
3536 Enables allocating and saving kernel cmdline in space between
3537 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3539 - CONFIG_SYS_BOOT_GET_KBD:
3540 Enables allocating and saving a kernel copy of the bd_info in
3541 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3543 - CONFIG_SYS_MAX_FLASH_BANKS:
3544 Max number of Flash memory banks
3546 - CONFIG_SYS_MAX_FLASH_SECT:
3547 Max number of sectors on a Flash chip
3549 - CONFIG_SYS_FLASH_ERASE_TOUT:
3550 Timeout for Flash erase operations (in ms)
3552 - CONFIG_SYS_FLASH_WRITE_TOUT:
3553 Timeout for Flash write operations (in ms)
3555 - CONFIG_SYS_FLASH_LOCK_TOUT
3556 Timeout for Flash set sector lock bit operation (in ms)
3558 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3559 Timeout for Flash clear lock bits operation (in ms)
3561 - CONFIG_SYS_FLASH_PROTECTION
3562 If defined, hardware flash sectors protection is used
3563 instead of U-Boot software protection.
3565 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3567 Enable TFTP transfers directly to flash memory;
3568 without this option such a download has to be
3569 performed in two steps: (1) download to RAM, and (2)
3570 copy from RAM to flash.
3572 The two-step approach is usually more reliable, since
3573 you can check if the download worked before you erase
3574 the flash, but in some situations (when system RAM is
3575 too limited to allow for a temporary copy of the
3576 downloaded image) this option may be very useful.
3578 - CONFIG_SYS_FLASH_CFI:
3579 Define if the flash driver uses extra elements in the
3580 common flash structure for storing flash geometry.
3582 - CONFIG_FLASH_CFI_DRIVER
3583 This option also enables the building of the cfi_flash driver
3584 in the drivers directory
3586 - CONFIG_FLASH_CFI_MTD
3587 This option enables the building of the cfi_mtd driver
3588 in the drivers directory. The driver exports CFI flash
3591 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3592 Use buffered writes to flash.
3594 - CONFIG_FLASH_SPANSION_S29WS_N
3595 s29ws-n MirrorBit flash has non-standard addresses for buffered
3598 - CONFIG_SYS_FLASH_QUIET_TEST
3599 If this option is defined, the common CFI flash doesn't
3600 print it's warning upon not recognized FLASH banks. This
3601 is useful, if some of the configured banks are only
3602 optionally available.
3604 - CONFIG_FLASH_SHOW_PROGRESS
3605 If defined (must be an integer), print out countdown
3606 digits and dots. Recommended value: 45 (9..1) for 80
3607 column displays, 15 (3..1) for 40 column displays.
3609 - CONFIG_FLASH_VERIFY
3610 If defined, the content of the flash (destination) is compared
3611 against the source after the write operation. An error message
3612 will be printed when the contents are not identical.
3613 Please note that this option is useless in nearly all cases,
3614 since such flash programming errors usually are detected earlier
3615 while unprotecting/erasing/programming. Please only enable
3616 this option if you really know what you are doing.
3618 - CONFIG_SYS_RX_ETH_BUFFER:
3619 Defines the number of Ethernet receive buffers. On some
3620 Ethernet controllers it is recommended to set this value
3621 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3622 buffers can be full shortly after enabling the interface
3623 on high Ethernet traffic.
3624 Defaults to 4 if not defined.
3626 - CONFIG_ENV_MAX_ENTRIES
3628 Maximum number of entries in the hash table that is used
3629 internally to store the environment settings. The default
3630 setting is supposed to be generous and should work in most
3631 cases. This setting can be used to tune behaviour; see
3632 lib/hashtable.c for details.
3634 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3635 - CONFIG_ENV_FLAGS_LIST_STATIC
3636 Enable validation of the values given to environment variables when
3637 calling env set. Variables can be restricted to only decimal,
3638 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3639 the variables can also be restricted to IP address or MAC address.
3641 The format of the list is:
3642 type_attribute = [s|d|x|b|i|m]
3643 access_atribute = [a|r|o|c]
3644 attributes = type_attribute[access_atribute]
3645 entry = variable_name[:attributes]
3648 The type attributes are:
3649 s - String (default)
3652 b - Boolean ([1yYtT|0nNfF])
3656 The access attributes are:
3662 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3663 Define this to a list (string) to define the ".flags"
3664 envirnoment variable in the default or embedded environment.
3666 - CONFIG_ENV_FLAGS_LIST_STATIC
3667 Define this to a list (string) to define validation that
3668 should be done if an entry is not found in the ".flags"
3669 environment variable. To override a setting in the static
3670 list, simply add an entry for the same variable name to the
3673 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3674 If defined, don't allow the -f switch to env set override variable
3677 - CONFIG_SYS_GENERIC_BOARD
3678 This selects the architecture-generic board system instead of the
3679 architecture-specific board files. It is intended to move boards
3680 to this new framework over time. Defining this will disable the
3681 arch/foo/lib/board.c file and use common/board_f.c and
3682 common/board_r.c instead. To use this option your architecture
3683 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3684 its config.mk file). If you find problems enabling this option on
3685 your board please report the problem and send patches!
3687 - CONFIG_SYS_SYM_OFFSETS
3688 This is set by architectures that use offsets for link symbols
3689 instead of absolute values. So bss_start is obtained using an
3690 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3691 directly. You should not need to touch this setting.
3693 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3694 This is set by OMAP boards for the max time that reset should
3695 be asserted. See doc/README.omap-reset-time for details on how
3696 the value can be calulated on a given board.
3698 The following definitions that deal with the placement and management
3699 of environment data (variable area); in general, we support the
3700 following configurations:
3702 - CONFIG_BUILD_ENVCRC:
3704 Builds up envcrc with the target environment so that external utils
3705 may easily extract it and embed it in final U-Boot images.
3707 - CONFIG_ENV_IS_IN_FLASH:
3709 Define this if the environment is in flash memory.
3711 a) The environment occupies one whole flash sector, which is
3712 "embedded" in the text segment with the U-Boot code. This
3713 happens usually with "bottom boot sector" or "top boot
3714 sector" type flash chips, which have several smaller
3715 sectors at the start or the end. For instance, such a
3716 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3717 such a case you would place the environment in one of the
3718 4 kB sectors - with U-Boot code before and after it. With
3719 "top boot sector" type flash chips, you would put the
3720 environment in one of the last sectors, leaving a gap
3721 between U-Boot and the environment.
3723 - CONFIG_ENV_OFFSET:
3725 Offset of environment data (variable area) to the
3726 beginning of flash memory; for instance, with bottom boot
3727 type flash chips the second sector can be used: the offset
3728 for this sector is given here.
3730 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3734 This is just another way to specify the start address of
3735 the flash sector containing the environment (instead of
3738 - CONFIG_ENV_SECT_SIZE:
3740 Size of the sector containing the environment.
3743 b) Sometimes flash chips have few, equal sized, BIG sectors.
3744 In such a case you don't want to spend a whole sector for
3749 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3750 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3751 of this flash sector for the environment. This saves
3752 memory for the RAM copy of the environment.
3754 It may also save flash memory if you decide to use this
3755 when your environment is "embedded" within U-Boot code,
3756 since then the remainder of the flash sector could be used
3757 for U-Boot code. It should be pointed out that this is
3758 STRONGLY DISCOURAGED from a robustness point of view:
3759 updating the environment in flash makes it always
3760 necessary to erase the WHOLE sector. If something goes
3761 wrong before the contents has been restored from a copy in
3762 RAM, your target system will be dead.
3764 - CONFIG_ENV_ADDR_REDUND
3765 CONFIG_ENV_SIZE_REDUND
3767 These settings describe a second storage area used to hold
3768 a redundant copy of the environment data, so that there is
3769 a valid backup copy in case there is a power failure during
3770 a "saveenv" operation.
3772 BE CAREFUL! Any changes to the flash layout, and some changes to the
3773 source code will make it necessary to adapt <board>/u-boot.lds*
3777 - CONFIG_ENV_IS_IN_NVRAM:
3779 Define this if you have some non-volatile memory device
3780 (NVRAM, battery buffered SRAM) which you want to use for the
3786 These two #defines are used to determine the memory area you
3787 want to use for environment. It is assumed that this memory
3788 can just be read and written to, without any special
3791 BE CAREFUL! The first access to the environment happens quite early
3792 in U-Boot initalization (when we try to get the setting of for the
3793 console baudrate). You *MUST* have mapped your NVRAM area then, or
3796 Please note that even with NVRAM we still use a copy of the
3797 environment in RAM: we could work on NVRAM directly, but we want to
3798 keep settings there always unmodified except somebody uses "saveenv"
3799 to save the current settings.
3802 - CONFIG_ENV_IS_IN_EEPROM:
3804 Use this if you have an EEPROM or similar serial access
3805 device and a driver for it.
3807 - CONFIG_ENV_OFFSET:
3810 These two #defines specify the offset and size of the
3811 environment area within the total memory of your EEPROM.
3813 - CONFIG_SYS_I2C_EEPROM_ADDR:
3814 If defined, specified the chip address of the EEPROM device.
3815 The default address is zero.
3817 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3818 If defined, the number of bits used to address bytes in a
3819 single page in the EEPROM device. A 64 byte page, for example
3820 would require six bits.
3822 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3823 If defined, the number of milliseconds to delay between
3824 page writes. The default is zero milliseconds.
3826 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3827 The length in bytes of the EEPROM memory array address. Note
3828 that this is NOT the chip address length!
3830 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3831 EEPROM chips that implement "address overflow" are ones
3832 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3833 address and the extra bits end up in the "chip address" bit
3834 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3837 Note that we consider the length of the address field to
3838 still be one byte because the extra address bits are hidden
3839 in the chip address.
3841 - CONFIG_SYS_EEPROM_SIZE:
3842 The size in bytes of the EEPROM device.
3844 - CONFIG_ENV_EEPROM_IS_ON_I2C
3845 define this, if you have I2C and SPI activated, and your
3846 EEPROM, which holds the environment, is on the I2C bus.
3848 - CONFIG_I2C_ENV_EEPROM_BUS
3849 if you have an Environment on an EEPROM reached over
3850 I2C muxes, you can define here, how to reach this
3851 EEPROM. For example:
3853 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3855 EEPROM which holds the environment, is reached over
3856 a pca9547 i2c mux with address 0x70, channel 3.
3858 - CONFIG_ENV_IS_IN_DATAFLASH:
3860 Define this if you have a DataFlash memory device which you
3861 want to use for the environment.
3863 - CONFIG_ENV_OFFSET:
3867 These three #defines specify the offset and size of the
3868 environment area within the total memory of your DataFlash placed
3869 at the specified address.
3871 - CONFIG_ENV_IS_IN_REMOTE:
3873 Define this if you have a remote memory space which you
3874 want to use for the local device's environment.
3879 These two #defines specify the address and size of the
3880 environment area within the remote memory space. The
3881 local device can get the environment from remote memory
3882 space by SRIO or PCIE links.
3884 BE CAREFUL! For some special cases, the local device can not use
3885 "saveenv" command. For example, the local device will get the
3886 environment stored in a remote NOR flash by SRIO or PCIE link,
3887 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3889 - CONFIG_ENV_IS_IN_NAND:
3891 Define this if you have a NAND device which you want to use
3892 for the environment.
3894 - CONFIG_ENV_OFFSET:
3897 These two #defines specify the offset and size of the environment
3898 area within the first NAND device. CONFIG_ENV_OFFSET must be
3899 aligned to an erase block boundary.
3901 - CONFIG_ENV_OFFSET_REDUND (optional):
3903 This setting describes a second storage area of CONFIG_ENV_SIZE
3904 size used to hold a redundant copy of the environment data, so
3905 that there is a valid backup copy in case there is a power failure
3906 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3907 aligned to an erase block boundary.
3909 - CONFIG_ENV_RANGE (optional):
3911 Specifies the length of the region in which the environment
3912 can be written. This should be a multiple of the NAND device's
3913 block size. Specifying a range with more erase blocks than
3914 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3915 the range to be avoided.
3917 - CONFIG_ENV_OFFSET_OOB (optional):
3919 Enables support for dynamically retrieving the offset of the
3920 environment from block zero's out-of-band data. The
3921 "nand env.oob" command can be used to record this offset.
3922 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3923 using CONFIG_ENV_OFFSET_OOB.
3925 - CONFIG_NAND_ENV_DST
3927 Defines address in RAM to which the nand_spl code should copy the
3928 environment. If redundant environment is used, it will be copied to
3929 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3931 - CONFIG_ENV_IS_IN_UBI:
3933 Define this if you have an UBI volume that you want to use for the
3934 environment. This has the benefit of wear-leveling the environment
3935 accesses, which is important on NAND.
3937 - CONFIG_ENV_UBI_PART:
3939 Define this to a string that is the mtd partition containing the UBI.
3941 - CONFIG_ENV_UBI_VOLUME:
3943 Define this to the name of the volume that you want to store the
3946 - CONFIG_ENV_UBI_VOLUME_REDUND:
3948 Define this to the name of another volume to store a second copy of
3949 the environment in. This will enable redundant environments in UBI.
3950 It is assumed that both volumes are in the same MTD partition.
3952 - CONFIG_UBI_SILENCE_MSG
3953 - CONFIG_UBIFS_SILENCE_MSG
3955 You will probably want to define these to avoid a really noisy system
3956 when storing the env in UBI.
3958 - CONFIG_ENV_IS_IN_MMC:
3960 Define this if you have an MMC device which you want to use for the
3963 - CONFIG_SYS_MMC_ENV_DEV:
3965 Specifies which MMC device the environment is stored in.
3967 - CONFIG_SYS_MMC_ENV_PART (optional):
3969 Specifies which MMC partition the environment is stored in. If not
3970 set, defaults to partition 0, the user area. Common values might be
3971 1 (first MMC boot partition), 2 (second MMC boot partition).
3973 - CONFIG_ENV_OFFSET:
3976 These two #defines specify the offset and size of the environment
3977 area within the specified MMC device.
3979 If offset is positive (the usual case), it is treated as relative to
3980 the start of the MMC partition. If offset is negative, it is treated
3981 as relative to the end of the MMC partition. This can be useful if
3982 your board may be fitted with different MMC devices, which have
3983 different sizes for the MMC partitions, and you always want the
3984 environment placed at the very end of the partition, to leave the
3985 maximum possible space before it, to store other data.
3987 These two values are in units of bytes, but must be aligned to an
3988 MMC sector boundary.
3990 - CONFIG_ENV_OFFSET_REDUND (optional):
3992 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3993 hold a redundant copy of the environment data. This provides a
3994 valid backup copy in case the other copy is corrupted, e.g. due
3995 to a power failure during a "saveenv" operation.
3997 This value may also be positive or negative; this is handled in the
3998 same way as CONFIG_ENV_OFFSET.
4000 This value is also in units of bytes, but must also be aligned to
4001 an MMC sector boundary.
4003 - CONFIG_ENV_SIZE_REDUND (optional):
4005 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4006 set. If this value is set, it must be set to the same value as
4009 - CONFIG_SYS_SPI_INIT_OFFSET
4011 Defines offset to the initial SPI buffer area in DPRAM. The
4012 area is used at an early stage (ROM part) if the environment
4013 is configured to reside in the SPI EEPROM: We need a 520 byte
4014 scratch DPRAM area. It is used between the two initialization
4015 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4016 to be a good choice since it makes it far enough from the
4017 start of the data area as well as from the stack pointer.
4019 Please note that the environment is read-only until the monitor
4020 has been relocated to RAM and a RAM copy of the environment has been
4021 created; also, when using EEPROM you will have to use getenv_f()
4022 until then to read environment variables.
4024 The environment is protected by a CRC32 checksum. Before the monitor
4025 is relocated into RAM, as a result of a bad CRC you will be working
4026 with the compiled-in default environment - *silently*!!! [This is
4027 necessary, because the first environment variable we need is the
4028 "baudrate" setting for the console - if we have a bad CRC, we don't
4029 have any device yet where we could complain.]
4031 Note: once the monitor has been relocated, then it will complain if
4032 the default environment is used; a new CRC is computed as soon as you
4033 use the "saveenv" command to store a valid environment.
4035 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4036 Echo the inverted Ethernet link state to the fault LED.
4038 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4039 also needs to be defined.
4041 - CONFIG_SYS_FAULT_MII_ADDR:
4042 MII address of the PHY to check for the Ethernet link state.
4044 - CONFIG_NS16550_MIN_FUNCTIONS:
4045 Define this if you desire to only have use of the NS16550_init
4046 and NS16550_putc functions for the serial driver located at
4047 drivers/serial/ns16550.c. This option is useful for saving
4048 space for already greatly restricted images, including but not
4049 limited to NAND_SPL configurations.
4051 - CONFIG_DISPLAY_BOARDINFO
4052 Display information about the board that U-Boot is running on
4053 when U-Boot starts up. The board function checkboard() is called
4056 - CONFIG_DISPLAY_BOARDINFO_LATE
4057 Similar to the previous option, but display this information
4058 later, once stdio is running and output goes to the LCD, if
4061 Low Level (hardware related) configuration options:
4062 ---------------------------------------------------
4064 - CONFIG_SYS_CACHELINE_SIZE:
4065 Cache Line Size of the CPU.
4067 - CONFIG_SYS_DEFAULT_IMMR:
4068 Default address of the IMMR after system reset.
4070 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4071 and RPXsuper) to be able to adjust the position of
4072 the IMMR register after a reset.
4074 - CONFIG_SYS_CCSRBAR_DEFAULT:
4075 Default (power-on reset) physical address of CCSR on Freescale
4078 - CONFIG_SYS_CCSRBAR:
4079 Virtual address of CCSR. On a 32-bit build, this is typically
4080 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4082 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4083 for cross-platform code that uses that macro instead.
4085 - CONFIG_SYS_CCSRBAR_PHYS:
4086 Physical address of CCSR. CCSR can be relocated to a new
4087 physical address, if desired. In this case, this macro should
4088 be set to that address. Otherwise, it should be set to the
4089 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4090 is typically relocated on 36-bit builds. It is recommended
4091 that this macro be defined via the _HIGH and _LOW macros:
4093 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4094 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4096 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4097 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4098 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4099 used in assembly code, so it must not contain typecasts or
4100 integer size suffixes (e.g. "ULL").
4102 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4103 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4104 used in assembly code, so it must not contain typecasts or
4105 integer size suffixes (e.g. "ULL").
4107 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4108 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4109 forced to a value that ensures that CCSR is not relocated.
4111 - Floppy Disk Support:
4112 CONFIG_SYS_FDC_DRIVE_NUMBER
4114 the default drive number (default value 0)
4116 CONFIG_SYS_ISA_IO_STRIDE
4118 defines the spacing between FDC chipset registers
4121 CONFIG_SYS_ISA_IO_OFFSET
4123 defines the offset of register from address. It
4124 depends on which part of the data bus is connected to
4125 the FDC chipset. (default value 0)
4127 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4128 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4131 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4132 fdc_hw_init() is called at the beginning of the FDC
4133 setup. fdc_hw_init() must be provided by the board
4134 source code. It is used to make hardware dependant
4138 Most IDE controllers were designed to be connected with PCI
4139 interface. Only few of them were designed for AHB interface.
4140 When software is doing ATA command and data transfer to
4141 IDE devices through IDE-AHB controller, some additional
4142 registers accessing to these kind of IDE-AHB controller
4145 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4146 DO NOT CHANGE unless you know exactly what you're
4147 doing! (11-4) [MPC8xx/82xx systems only]
4149 - CONFIG_SYS_INIT_RAM_ADDR:
4151 Start address of memory area that can be used for
4152 initial data and stack; please note that this must be
4153 writable memory that is working WITHOUT special
4154 initialization, i. e. you CANNOT use normal RAM which
4155 will become available only after programming the
4156 memory controller and running certain initialization
4159 U-Boot uses the following memory types:
4160 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4161 - MPC824X: data cache
4162 - PPC4xx: data cache
4164 - CONFIG_SYS_GBL_DATA_OFFSET:
4166 Offset of the initial data structure in the memory
4167 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4168 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4169 data is located at the end of the available space
4170 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4171 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4172 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4173 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4176 On the MPC824X (or other systems that use the data
4177 cache for initial memory) the address chosen for
4178 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4179 point to an otherwise UNUSED address space between
4180 the top of RAM and the start of the PCI space.
4182 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4184 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4186 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4188 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4190 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4192 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4194 - CONFIG_SYS_OR_TIMING_SDRAM:
4197 - CONFIG_SYS_MAMR_PTA:
4198 periodic timer for refresh
4200 - CONFIG_SYS_DER: Debug Event Register (37-47)
4202 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4203 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4204 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4205 CONFIG_SYS_BR1_PRELIM:
4206 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4208 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4209 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4210 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4211 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4213 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4214 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4215 Machine Mode Register and Memory Periodic Timer
4216 Prescaler definitions (SDRAM timing)
4218 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4219 enable I2C microcode relocation patch (MPC8xx);
4220 define relocation offset in DPRAM [DSP2]
4222 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4223 enable SMC microcode relocation patch (MPC8xx);
4224 define relocation offset in DPRAM [SMC1]
4226 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4227 enable SPI microcode relocation patch (MPC8xx);
4228 define relocation offset in DPRAM [SCC4]
4230 - CONFIG_SYS_USE_OSCCLK:
4231 Use OSCM clock mode on MBX8xx board. Be careful,
4232 wrong setting might damage your board. Read
4233 doc/README.MBX before setting this variable!
4235 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4236 Offset of the bootmode word in DPRAM used by post
4237 (Power On Self Tests). This definition overrides
4238 #define'd default value in commproc.h resp.
4241 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4242 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4243 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4244 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4245 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4246 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4247 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4248 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4249 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4251 - CONFIG_PCI_DISABLE_PCIE:
4252 Disable PCI-Express on systems where it is supported but not
4255 - CONFIG_PCI_ENUM_ONLY
4256 Only scan through and get the devices on the busses.
4257 Don't do any setup work, presumably because someone or
4258 something has already done it, and we don't need to do it
4259 a second time. Useful for platforms that are pre-booted
4260 by coreboot or similar.
4262 - CONFIG_PCI_INDIRECT_BRIDGE:
4263 Enable support for indirect PCI bridges.
4266 Chip has SRIO or not
4269 Board has SRIO 1 port available
4272 Board has SRIO 2 port available
4274 - CONFIG_SRIO_PCIE_BOOT_MASTER
4275 Board can support master function for Boot from SRIO and PCIE
4277 - CONFIG_SYS_SRIOn_MEM_VIRT:
4278 Virtual Address of SRIO port 'n' memory region
4280 - CONFIG_SYS_SRIOn_MEM_PHYS:
4281 Physical Address of SRIO port 'n' memory region
4283 - CONFIG_SYS_SRIOn_MEM_SIZE:
4284 Size of SRIO port 'n' memory region
4286 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4287 Defined to tell the NAND controller that the NAND chip is using
4289 Not all NAND drivers use this symbol.
4290 Example of drivers that use it:
4291 - drivers/mtd/nand/ndfc.c
4292 - drivers/mtd/nand/mxc_nand.c
4294 - CONFIG_SYS_NDFC_EBC0_CFG
4295 Sets the EBC0_CFG register for the NDFC. If not defined
4296 a default value will be used.
4299 Get DDR timing information from an I2C EEPROM. Common
4300 with pluggable memory modules such as SODIMMs
4303 I2C address of the SPD EEPROM
4305 - CONFIG_SYS_SPD_BUS_NUM
4306 If SPD EEPROM is on an I2C bus other than the first
4307 one, specify here. Note that the value must resolve
4308 to something your driver can deal with.
4310 - CONFIG_SYS_DDR_RAW_TIMING
4311 Get DDR timing information from other than SPD. Common with
4312 soldered DDR chips onboard without SPD. DDR raw timing
4313 parameters are extracted from datasheet and hard-coded into
4314 header files or board specific files.
4316 - CONFIG_FSL_DDR_INTERACTIVE
4317 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4319 - CONFIG_SYS_83XX_DDR_USES_CS0
4320 Only for 83xx systems. If specified, then DDR should
4321 be configured using CS0 and CS1 instead of CS2 and CS3.
4323 - CONFIG_ETHER_ON_FEC[12]
4324 Define to enable FEC[12] on a 8xx series processor.
4326 - CONFIG_FEC[12]_PHY
4327 Define to the hardcoded PHY address which corresponds
4328 to the given FEC; i. e.
4329 #define CONFIG_FEC1_PHY 4
4330 means that the PHY with address 4 is connected to FEC1
4332 When set to -1, means to probe for first available.
4334 - CONFIG_FEC[12]_PHY_NORXERR
4335 The PHY does not have a RXERR line (RMII only).
4336 (so program the FEC to ignore it).
4339 Enable RMII mode for all FECs.
4340 Note that this is a global option, we can't
4341 have one FEC in standard MII mode and another in RMII mode.
4343 - CONFIG_CRC32_VERIFY
4344 Add a verify option to the crc32 command.
4347 => crc32 -v <address> <count> <crc32>
4349 Where address/count indicate a memory area
4350 and crc32 is the correct crc32 which the
4354 Add the "loopw" memory command. This only takes effect if
4355 the memory commands are activated globally (CONFIG_CMD_MEM).
4358 Add the "mdc" and "mwc" memory commands. These are cyclic
4363 This command will print 4 bytes (10,11,12,13) each 500 ms.
4365 => mwc.l 100 12345678 10
4366 This command will write 12345678 to address 100 all 10 ms.
4368 This only takes effect if the memory commands are activated
4369 globally (CONFIG_CMD_MEM).
4371 - CONFIG_SKIP_LOWLEVEL_INIT
4372 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4373 low level initializations (like setting up the memory
4374 controller) are omitted and/or U-Boot does not
4375 relocate itself into RAM.
4377 Normally this variable MUST NOT be defined. The only
4378 exception is when U-Boot is loaded (to RAM) by some
4379 other boot loader or by a debugger which performs
4380 these initializations itself.
4383 Modifies the behaviour of start.S when compiling a loader
4384 that is executed before the actual U-Boot. E.g. when
4385 compiling a NAND SPL.
4388 Modifies the behaviour of start.S when compiling a loader
4389 that is executed after the SPL and before the actual U-Boot.
4390 It is loaded by the SPL.
4392 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4393 Only for 85xx systems. If this variable is specified, the section
4394 .resetvec is not kept and the section .bootpg is placed in the
4395 previous 4k of the .text section.
4397 - CONFIG_ARCH_MAP_SYSMEM
4398 Generally U-Boot (and in particular the md command) uses
4399 effective address. It is therefore not necessary to regard
4400 U-Boot address as virtual addresses that need to be translated
4401 to physical addresses. However, sandbox requires this, since
4402 it maintains its own little RAM buffer which contains all
4403 addressable memory. This option causes some memory accesses
4404 to be mapped through map_sysmem() / unmap_sysmem().
4406 - CONFIG_USE_ARCH_MEMCPY
4407 CONFIG_USE_ARCH_MEMSET
4408 If these options are used a optimized version of memcpy/memset will
4409 be used if available. These functions may be faster under some
4410 conditions but may increase the binary size.
4412 - CONFIG_X86_RESET_VECTOR
4413 If defined, the x86 reset vector code is included. This is not
4414 needed when U-Boot is running from Coreboot.
4417 Defines the MPU clock speed (in MHz).
4419 NOTE : currently only supported on AM335x platforms.
4421 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4422 Enables the RTC32K OSC on AM33xx based plattforms
4424 Freescale QE/FMAN Firmware Support:
4425 -----------------------------------
4427 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4428 loading of "firmware", which is encoded in the QE firmware binary format.
4429 This firmware often needs to be loaded during U-Boot booting, so macros
4430 are used to identify the storage device (NOR flash, SPI, etc) and the address
4433 - CONFIG_SYS_QE_FMAN_FW_ADDR
4434 The address in the storage device where the firmware is located. The
4435 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4438 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4439 The maximum possible size of the firmware. The firmware binary format
4440 has a field that specifies the actual size of the firmware, but it
4441 might not be possible to read any part of the firmware unless some
4442 local storage is allocated to hold the entire firmware first.
4444 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4445 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4446 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4447 virtual address in NOR flash.
4449 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4450 Specifies that QE/FMAN firmware is located in NAND flash.
4451 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4453 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4454 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4455 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4457 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4458 Specifies that QE/FMAN firmware is located on the primary SPI
4459 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4461 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4462 Specifies that QE/FMAN firmware is located in the remote (master)
4463 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4464 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4465 window->master inbound window->master LAW->the ucode address in
4466 master's memory space.
4468 Building the Software:
4469 ======================
4471 Building U-Boot has been tested in several native build environments
4472 and in many different cross environments. Of course we cannot support
4473 all possibly existing versions of cross development tools in all
4474 (potentially obsolete) versions. In case of tool chain problems we
4475 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4476 which is extensively used to build and test U-Boot.
4478 If you are not using a native environment, it is assumed that you
4479 have GNU cross compiling tools available in your path. In this case,
4480 you must set the environment variable CROSS_COMPILE in your shell.
4481 Note that no changes to the Makefile or any other source files are
4482 necessary. For example using the ELDK on a 4xx CPU, please enter:
4484 $ CROSS_COMPILE=ppc_4xx-
4485 $ export CROSS_COMPILE
4487 Note: If you wish to generate Windows versions of the utilities in
4488 the tools directory you can use the MinGW toolchain
4489 (http://www.mingw.org). Set your HOST tools to the MinGW
4490 toolchain and execute 'make tools'. For example:
4492 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4494 Binaries such as tools/mkimage.exe will be created which can
4495 be executed on computers running Windows.
4497 U-Boot is intended to be simple to build. After installing the
4498 sources you must configure U-Boot for one specific board type. This
4503 where "NAME_config" is the name of one of the existing configu-
4504 rations; see boards.cfg for supported names.
4506 Note: for some board special configuration names may exist; check if
4507 additional information is available from the board vendor; for
4508 instance, the TQM823L systems are available without (standard)
4509 or with LCD support. You can select such additional "features"
4510 when choosing the configuration, i. e.
4513 - will configure for a plain TQM823L, i. e. no LCD support
4515 make TQM823L_LCD_config
4516 - will configure for a TQM823L with U-Boot console on LCD
4521 Finally, type "make all", and you should get some working U-Boot
4522 images ready for download to / installation on your system:
4524 - "u-boot.bin" is a raw binary image
4525 - "u-boot" is an image in ELF binary format
4526 - "u-boot.srec" is in Motorola S-Record format
4528 By default the build is performed locally and the objects are saved
4529 in the source directory. One of the two methods can be used to change
4530 this behavior and build U-Boot to some external directory:
4532 1. Add O= to the make command line invocations:
4534 make O=/tmp/build distclean
4535 make O=/tmp/build NAME_config
4536 make O=/tmp/build all
4538 2. Set environment variable BUILD_DIR to point to the desired location:
4540 export BUILD_DIR=/tmp/build
4545 Note that the command line "O=" setting overrides the BUILD_DIR environment
4549 Please be aware that the Makefiles assume you are using GNU make, so
4550 for instance on NetBSD you might need to use "gmake" instead of
4554 If the system board that you have is not listed, then you will need
4555 to port U-Boot to your hardware platform. To do this, follow these
4558 1. Add a new configuration option for your board to the toplevel
4559 "boards.cfg" file, using the existing entries as examples.
4560 Follow the instructions there to keep the boards in order.
4561 2. Create a new directory to hold your board specific code. Add any
4562 files you need. In your board directory, you will need at least
4563 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4564 3. Create a new configuration file "include/configs/<board>.h" for
4566 3. If you're porting U-Boot to a new CPU, then also create a new
4567 directory to hold your CPU specific code. Add any files you need.
4568 4. Run "make <board>_config" with your new name.
4569 5. Type "make", and you should get a working "u-boot.srec" file
4570 to be installed on your target system.
4571 6. Debug and solve any problems that might arise.
4572 [Of course, this last step is much harder than it sounds.]
4575 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4576 ==============================================================
4578 If you have modified U-Boot sources (for instance added a new board
4579 or support for new devices, a new CPU, etc.) you are expected to
4580 provide feedback to the other developers. The feedback normally takes
4581 the form of a "patch", i. e. a context diff against a certain (latest
4582 official or latest in the git repository) version of U-Boot sources.
4584 But before you submit such a patch, please verify that your modifi-
4585 cation did not break existing code. At least make sure that *ALL* of
4586 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4587 just run the "MAKEALL" script, which will configure and build U-Boot
4588 for ALL supported system. Be warned, this will take a while. You can
4589 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4590 environment variable to the script, i. e. to use the ELDK cross tools
4593 CROSS_COMPILE=ppc_8xx- MAKEALL
4595 or to build on a native PowerPC system you can type
4597 CROSS_COMPILE=' ' MAKEALL
4599 When using the MAKEALL script, the default behaviour is to build
4600 U-Boot in the source directory. This location can be changed by
4601 setting the BUILD_DIR environment variable. Also, for each target
4602 built, the MAKEALL script saves two log files (<target>.ERR and
4603 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4604 location can be changed by setting the MAKEALL_LOGDIR environment
4605 variable. For example:
4607 export BUILD_DIR=/tmp/build
4608 export MAKEALL_LOGDIR=/tmp/log
4609 CROSS_COMPILE=ppc_8xx- MAKEALL
4611 With the above settings build objects are saved in the /tmp/build,
4612 log files are saved in the /tmp/log and the source tree remains clean
4613 during the whole build process.
4616 See also "U-Boot Porting Guide" below.
4619 Monitor Commands - Overview:
4620 ============================
4622 go - start application at address 'addr'
4623 run - run commands in an environment variable
4624 bootm - boot application image from memory
4625 bootp - boot image via network using BootP/TFTP protocol
4626 bootz - boot zImage from memory
4627 tftpboot- boot image via network using TFTP protocol
4628 and env variables "ipaddr" and "serverip"
4629 (and eventually "gatewayip")
4630 tftpput - upload a file via network using TFTP protocol
4631 rarpboot- boot image via network using RARP/TFTP protocol
4632 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4633 loads - load S-Record file over serial line
4634 loadb - load binary file over serial line (kermit mode)
4636 mm - memory modify (auto-incrementing)
4637 nm - memory modify (constant address)
4638 mw - memory write (fill)
4640 cmp - memory compare
4641 crc32 - checksum calculation
4642 i2c - I2C sub-system
4643 sspi - SPI utility commands
4644 base - print or set address offset
4645 printenv- print environment variables
4646 setenv - set environment variables
4647 saveenv - save environment variables to persistent storage
4648 protect - enable or disable FLASH write protection
4649 erase - erase FLASH memory
4650 flinfo - print FLASH memory information
4651 nand - NAND memory operations (see doc/README.nand)
4652 bdinfo - print Board Info structure
4653 iminfo - print header information for application image
4654 coninfo - print console devices and informations
4655 ide - IDE sub-system
4656 loop - infinite loop on address range
4657 loopw - infinite write loop on address range
4658 mtest - simple RAM test
4659 icache - enable or disable instruction cache
4660 dcache - enable or disable data cache
4661 reset - Perform RESET of the CPU
4662 echo - echo args to console
4663 version - print monitor version
4664 help - print online help
4665 ? - alias for 'help'
4668 Monitor Commands - Detailed Description:
4669 ========================================
4673 For now: just type "help <command>".
4676 Environment Variables:
4677 ======================
4679 U-Boot supports user configuration using Environment Variables which
4680 can be made persistent by saving to Flash memory.
4682 Environment Variables are set using "setenv", printed using
4683 "printenv", and saved to Flash using "saveenv". Using "setenv"
4684 without a value can be used to delete a variable from the
4685 environment. As long as you don't save the environment you are
4686 working with an in-memory copy. In case the Flash area containing the
4687 environment is erased by accident, a default environment is provided.
4689 Some configuration options can be set using Environment Variables.
4691 List of environment variables (most likely not complete):
4693 baudrate - see CONFIG_BAUDRATE
4695 bootdelay - see CONFIG_BOOTDELAY
4697 bootcmd - see CONFIG_BOOTCOMMAND
4699 bootargs - Boot arguments when booting an RTOS image
4701 bootfile - Name of the image to load with TFTP
4703 bootm_low - Memory range available for image processing in the bootm
4704 command can be restricted. This variable is given as
4705 a hexadecimal number and defines lowest address allowed
4706 for use by the bootm command. See also "bootm_size"
4707 environment variable. Address defined by "bootm_low" is
4708 also the base of the initial memory mapping for the Linux
4709 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4712 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4713 This variable is given as a hexadecimal number and it
4714 defines the size of the memory region starting at base
4715 address bootm_low that is accessible by the Linux kernel
4716 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4717 as the default value if it is defined, and bootm_size is
4720 bootm_size - Memory range available for image processing in the bootm
4721 command can be restricted. This variable is given as
4722 a hexadecimal number and defines the size of the region
4723 allowed for use by the bootm command. See also "bootm_low"
4724 environment variable.
4726 updatefile - Location of the software update file on a TFTP server, used
4727 by the automatic software update feature. Please refer to
4728 documentation in doc/README.update for more details.
4730 autoload - if set to "no" (any string beginning with 'n'),
4731 "bootp" will just load perform a lookup of the
4732 configuration from the BOOTP server, but not try to
4733 load any image using TFTP
4735 autostart - if set to "yes", an image loaded using the "bootp",
4736 "rarpboot", "tftpboot" or "diskboot" commands will
4737 be automatically started (by internally calling
4740 If set to "no", a standalone image passed to the
4741 "bootm" command will be copied to the load address
4742 (and eventually uncompressed), but NOT be started.
4743 This can be used to load and uncompress arbitrary
4746 fdt_high - if set this restricts the maximum address that the
4747 flattened device tree will be copied into upon boot.
4748 For example, if you have a system with 1 GB memory
4749 at physical address 0x10000000, while Linux kernel
4750 only recognizes the first 704 MB as low memory, you
4751 may need to set fdt_high as 0x3C000000 to have the
4752 device tree blob be copied to the maximum address
4753 of the 704 MB low memory, so that Linux kernel can
4754 access it during the boot procedure.
4756 If this is set to the special value 0xFFFFFFFF then
4757 the fdt will not be copied at all on boot. For this
4758 to work it must reside in writable memory, have
4759 sufficient padding on the end of it for u-boot to
4760 add the information it needs into it, and the memory
4761 must be accessible by the kernel.
4763 fdtcontroladdr- if set this is the address of the control flattened
4764 device tree used by U-Boot when CONFIG_OF_CONTROL is
4767 i2cfast - (PPC405GP|PPC405EP only)
4768 if set to 'y' configures Linux I2C driver for fast
4769 mode (400kHZ). This environment variable is used in
4770 initialization code. So, for changes to be effective
4771 it must be saved and board must be reset.
4773 initrd_high - restrict positioning of initrd images:
4774 If this variable is not set, initrd images will be
4775 copied to the highest possible address in RAM; this
4776 is usually what you want since it allows for
4777 maximum initrd size. If for some reason you want to
4778 make sure that the initrd image is loaded below the
4779 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4780 variable to a value of "no" or "off" or "0".
4781 Alternatively, you can set it to a maximum upper
4782 address to use (U-Boot will still check that it
4783 does not overwrite the U-Boot stack and data).
4785 For instance, when you have a system with 16 MB
4786 RAM, and want to reserve 4 MB from use by Linux,
4787 you can do this by adding "mem=12M" to the value of
4788 the "bootargs" variable. However, now you must make
4789 sure that the initrd image is placed in the first
4790 12 MB as well - this can be done with
4792 setenv initrd_high 00c00000
4794 If you set initrd_high to 0xFFFFFFFF, this is an
4795 indication to U-Boot that all addresses are legal
4796 for the Linux kernel, including addresses in flash
4797 memory. In this case U-Boot will NOT COPY the
4798 ramdisk at all. This may be useful to reduce the
4799 boot time on your system, but requires that this
4800 feature is supported by your Linux kernel.
4802 ipaddr - IP address; needed for tftpboot command
4804 loadaddr - Default load address for commands like "bootp",
4805 "rarpboot", "tftpboot", "loadb" or "diskboot"
4807 loads_echo - see CONFIG_LOADS_ECHO
4809 serverip - TFTP server IP address; needed for tftpboot command
4811 bootretry - see CONFIG_BOOT_RETRY_TIME
4813 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4815 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4817 ethprime - controls which interface is used first.
4819 ethact - controls which interface is currently active.
4820 For example you can do the following
4822 => setenv ethact FEC
4823 => ping 192.168.0.1 # traffic sent on FEC
4824 => setenv ethact SCC
4825 => ping 10.0.0.1 # traffic sent on SCC
4827 ethrotate - When set to "no" U-Boot does not go through all
4828 available network interfaces.
4829 It just stays at the currently selected interface.
4831 netretry - When set to "no" each network operation will
4832 either succeed or fail without retrying.
4833 When set to "once" the network operation will
4834 fail when all the available network interfaces
4835 are tried once without success.
4836 Useful on scripts which control the retry operation
4839 npe_ucode - set load address for the NPE microcode
4841 silent_linux - If set then linux will be told to boot silently, by
4842 changing the console to be empty. If "yes" it will be
4843 made silent. If "no" it will not be made silent. If
4844 unset, then it will be made silent if the U-Boot console
4847 tftpsrcport - If this is set, the value is used for TFTP's
4850 tftpdstport - If this is set, the value is used for TFTP's UDP
4851 destination port instead of the Well Know Port 69.
4853 tftpblocksize - Block size to use for TFTP transfers; if not set,
4854 we use the TFTP server's default block size
4856 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4857 seconds, minimum value is 1000 = 1 second). Defines
4858 when a packet is considered to be lost so it has to
4859 be retransmitted. The default is 5000 = 5 seconds.
4860 Lowering this value may make downloads succeed
4861 faster in networks with high packet loss rates or
4862 with unreliable TFTP servers.
4864 vlan - When set to a value < 4095 the traffic over
4865 Ethernet is encapsulated/received over 802.1q
4868 The following image location variables contain the location of images
4869 used in booting. The "Image" column gives the role of the image and is
4870 not an environment variable name. The other columns are environment
4871 variable names. "File Name" gives the name of the file on a TFTP
4872 server, "RAM Address" gives the location in RAM the image will be
4873 loaded to, and "Flash Location" gives the image's address in NOR
4874 flash or offset in NAND flash.
4876 *Note* - these variables don't have to be defined for all boards, some
4877 boards currenlty use other variables for these purposes, and some
4878 boards use these variables for other purposes.
4880 Image File Name RAM Address Flash Location
4881 ----- --------- ----------- --------------
4882 u-boot u-boot u-boot_addr_r u-boot_addr
4883 Linux kernel bootfile kernel_addr_r kernel_addr
4884 device tree blob fdtfile fdt_addr_r fdt_addr
4885 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4887 The following environment variables may be used and automatically
4888 updated by the network boot commands ("bootp" and "rarpboot"),
4889 depending the information provided by your boot server:
4891 bootfile - see above
4892 dnsip - IP address of your Domain Name Server
4893 dnsip2 - IP address of your secondary Domain Name Server
4894 gatewayip - IP address of the Gateway (Router) to use
4895 hostname - Target hostname
4897 netmask - Subnet Mask
4898 rootpath - Pathname of the root filesystem on the NFS server
4899 serverip - see above
4902 There are two special Environment Variables:
4904 serial# - contains hardware identification information such
4905 as type string and/or serial number
4906 ethaddr - Ethernet address
4908 These variables can be set only once (usually during manufacturing of
4909 the board). U-Boot refuses to delete or overwrite these variables
4910 once they have been set once.
4913 Further special Environment Variables:
4915 ver - Contains the U-Boot version string as printed
4916 with the "version" command. This variable is
4917 readonly (see CONFIG_VERSION_VARIABLE).
4920 Please note that changes to some configuration parameters may take
4921 only effect after the next boot (yes, that's just like Windoze :-).
4924 Callback functions for environment variables:
4925 ---------------------------------------------
4927 For some environment variables, the behavior of u-boot needs to change
4928 when their values are changed. This functionailty allows functions to
4929 be associated with arbitrary variables. On creation, overwrite, or
4930 deletion, the callback will provide the opportunity for some side
4931 effect to happen or for the change to be rejected.
4933 The callbacks are named and associated with a function using the
4934 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4936 These callbacks are associated with variables in one of two ways. The
4937 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4938 in the board configuration to a string that defines a list of
4939 associations. The list must be in the following format:
4941 entry = variable_name[:callback_name]
4944 If the callback name is not specified, then the callback is deleted.
4945 Spaces are also allowed anywhere in the list.
4947 Callbacks can also be associated by defining the ".callbacks" variable
4948 with the same list format above. Any association in ".callbacks" will
4949 override any association in the static list. You can define
4950 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4951 ".callbacks" envirnoment variable in the default or embedded environment.
4954 Command Line Parsing:
4955 =====================
4957 There are two different command line parsers available with U-Boot:
4958 the old "simple" one, and the much more powerful "hush" shell:
4960 Old, simple command line parser:
4961 --------------------------------
4963 - supports environment variables (through setenv / saveenv commands)
4964 - several commands on one line, separated by ';'
4965 - variable substitution using "... ${name} ..." syntax
4966 - special characters ('$', ';') can be escaped by prefixing with '\',
4968 setenv bootcmd bootm \${address}
4969 - You can also escape text by enclosing in single apostrophes, for example:
4970 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4975 - similar to Bourne shell, with control structures like
4976 if...then...else...fi, for...do...done; while...do...done,
4977 until...do...done, ...
4978 - supports environment ("global") variables (through setenv / saveenv
4979 commands) and local shell variables (through standard shell syntax
4980 "name=value"); only environment variables can be used with "run"
4986 (1) If a command line (or an environment variable executed by a "run"
4987 command) contains several commands separated by semicolon, and
4988 one of these commands fails, then the remaining commands will be
4991 (2) If you execute several variables with one call to run (i. e.
4992 calling run with a list of variables as arguments), any failing
4993 command will cause "run" to terminate, i. e. the remaining
4994 variables are not executed.
4996 Note for Redundant Ethernet Interfaces:
4997 =======================================
4999 Some boards come with redundant Ethernet interfaces; U-Boot supports
5000 such configurations and is capable of automatic selection of a
5001 "working" interface when needed. MAC assignment works as follows:
5003 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5004 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5005 "eth1addr" (=>eth1), "eth2addr", ...
5007 If the network interface stores some valid MAC address (for instance
5008 in SROM), this is used as default address if there is NO correspon-
5009 ding setting in the environment; if the corresponding environment
5010 variable is set, this overrides the settings in the card; that means:
5012 o If the SROM has a valid MAC address, and there is no address in the
5013 environment, the SROM's address is used.
5015 o If there is no valid address in the SROM, and a definition in the
5016 environment exists, then the value from the environment variable is
5019 o If both the SROM and the environment contain a MAC address, and
5020 both addresses are the same, this MAC address is used.
5022 o If both the SROM and the environment contain a MAC address, and the
5023 addresses differ, the value from the environment is used and a
5026 o If neither SROM nor the environment contain a MAC address, an error
5029 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5030 will be programmed into hardware as part of the initialization process. This
5031 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5032 The naming convention is as follows:
5033 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5038 U-Boot is capable of booting (and performing other auxiliary operations on)
5039 images in two formats:
5041 New uImage format (FIT)
5042 -----------------------
5044 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5045 to Flattened Device Tree). It allows the use of images with multiple
5046 components (several kernels, ramdisks, etc.), with contents protected by
5047 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5053 Old image format is based on binary files which can be basically anything,
5054 preceded by a special header; see the definitions in include/image.h for
5055 details; basically, the header defines the following image properties:
5057 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5058 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5059 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5060 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5062 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5063 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5064 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5065 * Compression Type (uncompressed, gzip, bzip2)
5071 The header is marked by a special Magic Number, and both the header
5072 and the data portions of the image are secured against corruption by
5079 Although U-Boot should support any OS or standalone application
5080 easily, the main focus has always been on Linux during the design of
5083 U-Boot includes many features that so far have been part of some
5084 special "boot loader" code within the Linux kernel. Also, any
5085 "initrd" images to be used are no longer part of one big Linux image;
5086 instead, kernel and "initrd" are separate images. This implementation
5087 serves several purposes:
5089 - the same features can be used for other OS or standalone
5090 applications (for instance: using compressed images to reduce the
5091 Flash memory footprint)
5093 - it becomes much easier to port new Linux kernel versions because
5094 lots of low-level, hardware dependent stuff are done by U-Boot
5096 - the same Linux kernel image can now be used with different "initrd"
5097 images; of course this also means that different kernel images can
5098 be run with the same "initrd". This makes testing easier (you don't
5099 have to build a new "zImage.initrd" Linux image when you just
5100 change a file in your "initrd"). Also, a field-upgrade of the
5101 software is easier now.
5107 Porting Linux to U-Boot based systems:
5108 ---------------------------------------
5110 U-Boot cannot save you from doing all the necessary modifications to
5111 configure the Linux device drivers for use with your target hardware
5112 (no, we don't intend to provide a full virtual machine interface to
5115 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5117 Just make sure your machine specific header file (for instance
5118 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5119 Information structure as we define in include/asm-<arch>/u-boot.h,
5120 and make sure that your definition of IMAP_ADDR uses the same value
5121 as your U-Boot configuration in CONFIG_SYS_IMMR.
5124 Configuring the Linux kernel:
5125 -----------------------------
5127 No specific requirements for U-Boot. Make sure you have some root
5128 device (initial ramdisk, NFS) for your target system.
5131 Building a Linux Image:
5132 -----------------------
5134 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5135 not used. If you use recent kernel source, a new build target
5136 "uImage" will exist which automatically builds an image usable by
5137 U-Boot. Most older kernels also have support for a "pImage" target,
5138 which was introduced for our predecessor project PPCBoot and uses a
5139 100% compatible format.
5148 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5149 encapsulate a compressed Linux kernel image with header information,
5150 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5152 * build a standard "vmlinux" kernel image (in ELF binary format):
5154 * convert the kernel into a raw binary image:
5156 ${CROSS_COMPILE}-objcopy -O binary \
5157 -R .note -R .comment \
5158 -S vmlinux linux.bin
5160 * compress the binary image:
5164 * package compressed binary image for U-Boot:
5166 mkimage -A ppc -O linux -T kernel -C gzip \
5167 -a 0 -e 0 -n "Linux Kernel Image" \
5168 -d linux.bin.gz uImage
5171 The "mkimage" tool can also be used to create ramdisk images for use
5172 with U-Boot, either separated from the Linux kernel image, or
5173 combined into one file. "mkimage" encapsulates the images with a 64
5174 byte header containing information about target architecture,
5175 operating system, image type, compression method, entry points, time
5176 stamp, CRC32 checksums, etc.
5178 "mkimage" can be called in two ways: to verify existing images and
5179 print the header information, or to build new images.
5181 In the first form (with "-l" option) mkimage lists the information
5182 contained in the header of an existing U-Boot image; this includes
5183 checksum verification:
5185 tools/mkimage -l image
5186 -l ==> list image header information
5188 The second form (with "-d" option) is used to build a U-Boot image
5189 from a "data file" which is used as image payload:
5191 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5192 -n name -d data_file image
5193 -A ==> set architecture to 'arch'
5194 -O ==> set operating system to 'os'
5195 -T ==> set image type to 'type'
5196 -C ==> set compression type 'comp'
5197 -a ==> set load address to 'addr' (hex)
5198 -e ==> set entry point to 'ep' (hex)
5199 -n ==> set image name to 'name'
5200 -d ==> use image data from 'datafile'
5202 Right now, all Linux kernels for PowerPC systems use the same load
5203 address (0x00000000), but the entry point address depends on the
5206 - 2.2.x kernels have the entry point at 0x0000000C,
5207 - 2.3.x and later kernels have the entry point at 0x00000000.
5209 So a typical call to build a U-Boot image would read:
5211 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5212 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5213 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5214 > examples/uImage.TQM850L
5215 Image Name: 2.4.4 kernel for TQM850L
5216 Created: Wed Jul 19 02:34:59 2000
5217 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5218 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5219 Load Address: 0x00000000
5220 Entry Point: 0x00000000
5222 To verify the contents of the image (or check for corruption):
5224 -> tools/mkimage -l examples/uImage.TQM850L
5225 Image Name: 2.4.4 kernel for TQM850L
5226 Created: Wed Jul 19 02:34:59 2000
5227 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5228 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5229 Load Address: 0x00000000
5230 Entry Point: 0x00000000
5232 NOTE: for embedded systems where boot time is critical you can trade
5233 speed for memory and install an UNCOMPRESSED image instead: this
5234 needs more space in Flash, but boots much faster since it does not
5235 need to be uncompressed:
5237 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5238 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5239 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5240 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5241 > examples/uImage.TQM850L-uncompressed
5242 Image Name: 2.4.4 kernel for TQM850L
5243 Created: Wed Jul 19 02:34:59 2000
5244 Image Type: PowerPC Linux Kernel Image (uncompressed)
5245 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5246 Load Address: 0x00000000
5247 Entry Point: 0x00000000
5250 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5251 when your kernel is intended to use an initial ramdisk:
5253 -> tools/mkimage -n 'Simple Ramdisk Image' \
5254 > -A ppc -O linux -T ramdisk -C gzip \
5255 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5256 Image Name: Simple Ramdisk Image
5257 Created: Wed Jan 12 14:01:50 2000
5258 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5259 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5260 Load Address: 0x00000000
5261 Entry Point: 0x00000000
5263 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5264 option performs the converse operation of the mkimage's second form (the "-d"
5265 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5268 tools/dumpimage -i image -p position data_file
5269 -i ==> extract from the 'image' a specific 'data_file', \
5270 indexed by 'position'
5273 Installing a Linux Image:
5274 -------------------------
5276 To downloading a U-Boot image over the serial (console) interface,
5277 you must convert the image to S-Record format:
5279 objcopy -I binary -O srec examples/image examples/image.srec
5281 The 'objcopy' does not understand the information in the U-Boot
5282 image header, so the resulting S-Record file will be relative to
5283 address 0x00000000. To load it to a given address, you need to
5284 specify the target address as 'offset' parameter with the 'loads'
5287 Example: install the image to address 0x40100000 (which on the
5288 TQM8xxL is in the first Flash bank):
5290 => erase 40100000 401FFFFF
5296 ## Ready for S-Record download ...
5297 ~>examples/image.srec
5298 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5300 15989 15990 15991 15992
5301 [file transfer complete]
5303 ## Start Addr = 0x00000000
5306 You can check the success of the download using the 'iminfo' command;
5307 this includes a checksum verification so you can be sure no data
5308 corruption happened:
5312 ## Checking Image at 40100000 ...
5313 Image Name: 2.2.13 for initrd on TQM850L
5314 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5315 Data Size: 335725 Bytes = 327 kB = 0 MB
5316 Load Address: 00000000
5317 Entry Point: 0000000c
5318 Verifying Checksum ... OK
5324 The "bootm" command is used to boot an application that is stored in
5325 memory (RAM or Flash). In case of a Linux kernel image, the contents
5326 of the "bootargs" environment variable is passed to the kernel as
5327 parameters. You can check and modify this variable using the
5328 "printenv" and "setenv" commands:
5331 => printenv bootargs
5332 bootargs=root=/dev/ram
5334 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5336 => printenv bootargs
5337 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5340 ## Booting Linux kernel at 40020000 ...
5341 Image Name: 2.2.13 for NFS on TQM850L
5342 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5343 Data Size: 381681 Bytes = 372 kB = 0 MB
5344 Load Address: 00000000
5345 Entry Point: 0000000c
5346 Verifying Checksum ... OK
5347 Uncompressing Kernel Image ... OK
5348 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
5349 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5350 time_init: decrementer frequency = 187500000/60
5351 Calibrating delay loop... 49.77 BogoMIPS
5352 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5355 If you want to boot a Linux kernel with initial RAM disk, you pass
5356 the memory addresses of both the kernel and the initrd image (PPBCOOT
5357 format!) to the "bootm" command:
5359 => imi 40100000 40200000
5361 ## Checking Image at 40100000 ...
5362 Image Name: 2.2.13 for initrd on TQM850L
5363 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5364 Data Size: 335725 Bytes = 327 kB = 0 MB
5365 Load Address: 00000000
5366 Entry Point: 0000000c
5367 Verifying Checksum ... OK
5369 ## Checking Image at 40200000 ...
5370 Image Name: Simple Ramdisk Image
5371 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5372 Data Size: 566530 Bytes = 553 kB = 0 MB
5373 Load Address: 00000000
5374 Entry Point: 00000000
5375 Verifying Checksum ... OK
5377 => bootm 40100000 40200000
5378 ## Booting Linux kernel at 40100000 ...
5379 Image Name: 2.2.13 for initrd on TQM850L
5380 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5381 Data Size: 335725 Bytes = 327 kB = 0 MB
5382 Load Address: 00000000
5383 Entry Point: 0000000c
5384 Verifying Checksum ... OK
5385 Uncompressing Kernel Image ... OK
5386 ## Loading RAMDisk Image at 40200000 ...
5387 Image Name: Simple Ramdisk Image
5388 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5389 Data Size: 566530 Bytes = 553 kB = 0 MB
5390 Load Address: 00000000
5391 Entry Point: 00000000
5392 Verifying Checksum ... OK
5393 Loading Ramdisk ... OK
5394 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
5395 Boot arguments: root=/dev/ram
5396 time_init: decrementer frequency = 187500000/60
5397 Calibrating delay loop... 49.77 BogoMIPS
5399 RAMDISK: Compressed image found at block 0
5400 VFS: Mounted root (ext2 filesystem).
5404 Boot Linux and pass a flat device tree:
5407 First, U-Boot must be compiled with the appropriate defines. See the section
5408 titled "Linux Kernel Interface" above for a more in depth explanation. The
5409 following is an example of how to start a kernel and pass an updated
5415 oft=oftrees/mpc8540ads.dtb
5416 => tftp $oftaddr $oft
5417 Speed: 1000, full duplex
5419 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5420 Filename 'oftrees/mpc8540ads.dtb'.
5421 Load address: 0x300000
5424 Bytes transferred = 4106 (100a hex)
5425 => tftp $loadaddr $bootfile
5426 Speed: 1000, full duplex
5428 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5430 Load address: 0x200000
5431 Loading:############
5433 Bytes transferred = 1029407 (fb51f hex)
5438 => bootm $loadaddr - $oftaddr
5439 ## Booting image at 00200000 ...
5440 Image Name: Linux-2.6.17-dirty
5441 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5442 Data Size: 1029343 Bytes = 1005.2 kB
5443 Load Address: 00000000
5444 Entry Point: 00000000
5445 Verifying Checksum ... OK
5446 Uncompressing Kernel Image ... OK
5447 Booting using flat device tree at 0x300000
5448 Using MPC85xx ADS machine description
5449 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5453 More About U-Boot Image Types:
5454 ------------------------------
5456 U-Boot supports the following image types:
5458 "Standalone Programs" are directly runnable in the environment
5459 provided by U-Boot; it is expected that (if they behave
5460 well) you can continue to work in U-Boot after return from
5461 the Standalone Program.
5462 "OS Kernel Images" are usually images of some Embedded OS which
5463 will take over control completely. Usually these programs
5464 will install their own set of exception handlers, device
5465 drivers, set up the MMU, etc. - this means, that you cannot
5466 expect to re-enter U-Boot except by resetting the CPU.
5467 "RAMDisk Images" are more or less just data blocks, and their
5468 parameters (address, size) are passed to an OS kernel that is
5470 "Multi-File Images" contain several images, typically an OS
5471 (Linux) kernel image and one or more data images like
5472 RAMDisks. This construct is useful for instance when you want
5473 to boot over the network using BOOTP etc., where the boot
5474 server provides just a single image file, but you want to get
5475 for instance an OS kernel and a RAMDisk image.
5477 "Multi-File Images" start with a list of image sizes, each
5478 image size (in bytes) specified by an "uint32_t" in network
5479 byte order. This list is terminated by an "(uint32_t)0".
5480 Immediately after the terminating 0 follow the images, one by
5481 one, all aligned on "uint32_t" boundaries (size rounded up to
5482 a multiple of 4 bytes).
5484 "Firmware Images" are binary images containing firmware (like
5485 U-Boot or FPGA images) which usually will be programmed to
5488 "Script files" are command sequences that will be executed by
5489 U-Boot's command interpreter; this feature is especially
5490 useful when you configure U-Boot to use a real shell (hush)
5491 as command interpreter.
5493 Booting the Linux zImage:
5494 -------------------------
5496 On some platforms, it's possible to boot Linux zImage. This is done
5497 using the "bootz" command. The syntax of "bootz" command is the same
5498 as the syntax of "bootm" command.
5500 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5501 kernel with raw initrd images. The syntax is slightly different, the
5502 address of the initrd must be augmented by it's size, in the following
5503 format: "<initrd addres>:<initrd size>".
5509 One of the features of U-Boot is that you can dynamically load and
5510 run "standalone" applications, which can use some resources of
5511 U-Boot like console I/O functions or interrupt services.
5513 Two simple examples are included with the sources:
5518 'examples/hello_world.c' contains a small "Hello World" Demo
5519 application; it is automatically compiled when you build U-Boot.
5520 It's configured to run at address 0x00040004, so you can play with it
5524 ## Ready for S-Record download ...
5525 ~>examples/hello_world.srec
5526 1 2 3 4 5 6 7 8 9 10 11 ...
5527 [file transfer complete]
5529 ## Start Addr = 0x00040004
5531 => go 40004 Hello World! This is a test.
5532 ## Starting application at 0x00040004 ...
5543 Hit any key to exit ...
5545 ## Application terminated, rc = 0x0
5547 Another example, which demonstrates how to register a CPM interrupt
5548 handler with the U-Boot code, can be found in 'examples/timer.c'.
5549 Here, a CPM timer is set up to generate an interrupt every second.
5550 The interrupt service routine is trivial, just printing a '.'
5551 character, but this is just a demo program. The application can be
5552 controlled by the following keys:
5554 ? - print current values og the CPM Timer registers
5555 b - enable interrupts and start timer
5556 e - stop timer and disable interrupts
5557 q - quit application
5560 ## Ready for S-Record download ...
5561 ~>examples/timer.srec
5562 1 2 3 4 5 6 7 8 9 10 11 ...
5563 [file transfer complete]
5565 ## Start Addr = 0x00040004
5568 ## Starting application at 0x00040004 ...
5571 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5574 [q, b, e, ?] Set interval 1000000 us
5577 [q, b, e, ?] ........
5578 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5581 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5584 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5587 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5589 [q, b, e, ?] ...Stopping timer
5591 [q, b, e, ?] ## Application terminated, rc = 0x0
5597 Over time, many people have reported problems when trying to use the
5598 "minicom" terminal emulation program for serial download. I (wd)
5599 consider minicom to be broken, and recommend not to use it. Under
5600 Unix, I recommend to use C-Kermit for general purpose use (and
5601 especially for kermit binary protocol download ("loadb" command), and
5602 use "cu" for S-Record download ("loads" command). See
5603 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5604 for help with kermit.
5607 Nevertheless, if you absolutely want to use it try adding this
5608 configuration to your "File transfer protocols" section:
5610 Name Program Name U/D FullScr IO-Red. Multi
5611 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5612 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5618 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5619 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5621 Building requires a cross environment; it is known to work on
5622 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5623 need gmake since the Makefiles are not compatible with BSD make).
5624 Note that the cross-powerpc package does not install include files;
5625 attempting to build U-Boot will fail because <machine/ansi.h> is
5626 missing. This file has to be installed and patched manually:
5628 # cd /usr/pkg/cross/powerpc-netbsd/include
5630 # ln -s powerpc machine
5631 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5632 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5634 Native builds *don't* work due to incompatibilities between native
5635 and U-Boot include files.
5637 Booting assumes that (the first part of) the image booted is a
5638 stage-2 loader which in turn loads and then invokes the kernel
5639 proper. Loader sources will eventually appear in the NetBSD source
5640 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5641 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5644 Implementation Internals:
5645 =========================
5647 The following is not intended to be a complete description of every
5648 implementation detail. However, it should help to understand the
5649 inner workings of U-Boot and make it easier to port it to custom
5653 Initial Stack, Global Data:
5654 ---------------------------
5656 The implementation of U-Boot is complicated by the fact that U-Boot
5657 starts running out of ROM (flash memory), usually without access to
5658 system RAM (because the memory controller is not initialized yet).
5659 This means that we don't have writable Data or BSS segments, and BSS
5660 is not initialized as zero. To be able to get a C environment working
5661 at all, we have to allocate at least a minimal stack. Implementation
5662 options for this are defined and restricted by the CPU used: Some CPU
5663 models provide on-chip memory (like the IMMR area on MPC8xx and
5664 MPC826x processors), on others (parts of) the data cache can be
5665 locked as (mis-) used as memory, etc.
5667 Chris Hallinan posted a good summary of these issues to the
5668 U-Boot mailing list:
5670 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5671 From: "Chris Hallinan" <clh@net1plus.com>
5672 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5675 Correct me if I'm wrong, folks, but the way I understand it
5676 is this: Using DCACHE as initial RAM for Stack, etc, does not
5677 require any physical RAM backing up the cache. The cleverness
5678 is that the cache is being used as a temporary supply of
5679 necessary storage before the SDRAM controller is setup. It's
5680 beyond the scope of this list to explain the details, but you
5681 can see how this works by studying the cache architecture and
5682 operation in the architecture and processor-specific manuals.
5684 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5685 is another option for the system designer to use as an
5686 initial stack/RAM area prior to SDRAM being available. Either
5687 option should work for you. Using CS 4 should be fine if your
5688 board designers haven't used it for something that would
5689 cause you grief during the initial boot! It is frequently not
5692 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5693 with your processor/board/system design. The default value
5694 you will find in any recent u-boot distribution in
5695 walnut.h should work for you. I'd set it to a value larger
5696 than your SDRAM module. If you have a 64MB SDRAM module, set
5697 it above 400_0000. Just make sure your board has no resources
5698 that are supposed to respond to that address! That code in
5699 start.S has been around a while and should work as is when
5700 you get the config right.
5705 It is essential to remember this, since it has some impact on the C
5706 code for the initialization procedures:
5708 * Initialized global data (data segment) is read-only. Do not attempt
5711 * Do not use any uninitialized global data (or implicitely initialized
5712 as zero data - BSS segment) at all - this is undefined, initiali-
5713 zation is performed later (when relocating to RAM).
5715 * Stack space is very limited. Avoid big data buffers or things like
5718 Having only the stack as writable memory limits means we cannot use
5719 normal global data to share information beween the code. But it
5720 turned out that the implementation of U-Boot can be greatly
5721 simplified by making a global data structure (gd_t) available to all
5722 functions. We could pass a pointer to this data as argument to _all_
5723 functions, but this would bloat the code. Instead we use a feature of
5724 the GCC compiler (Global Register Variables) to share the data: we
5725 place a pointer (gd) to the global data into a register which we
5726 reserve for this purpose.
5728 When choosing a register for such a purpose we are restricted by the
5729 relevant (E)ABI specifications for the current architecture, and by
5730 GCC's implementation.
5732 For PowerPC, the following registers have specific use:
5734 R2: reserved for system use
5735 R3-R4: parameter passing and return values
5736 R5-R10: parameter passing
5737 R13: small data area pointer
5741 (U-Boot also uses R12 as internal GOT pointer. r12
5742 is a volatile register so r12 needs to be reset when
5743 going back and forth between asm and C)
5745 ==> U-Boot will use R2 to hold a pointer to the global data
5747 Note: on PPC, we could use a static initializer (since the
5748 address of the global data structure is known at compile time),
5749 but it turned out that reserving a register results in somewhat
5750 smaller code - although the code savings are not that big (on
5751 average for all boards 752 bytes for the whole U-Boot image,
5752 624 text + 127 data).
5754 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5755 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5757 ==> U-Boot will use P3 to hold a pointer to the global data
5759 On ARM, the following registers are used:
5761 R0: function argument word/integer result
5762 R1-R3: function argument word
5763 R9: platform specific
5764 R10: stack limit (used only if stack checking is enabled)
5765 R11: argument (frame) pointer
5766 R12: temporary workspace
5769 R15: program counter
5771 ==> U-Boot will use R9 to hold a pointer to the global data
5773 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5775 On Nios II, the ABI is documented here:
5776 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5778 ==> U-Boot will use gp to hold a pointer to the global data
5780 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5781 to access small data sections, so gp is free.
5783 On NDS32, the following registers are used:
5785 R0-R1: argument/return
5787 R15: temporary register for assembler
5788 R16: trampoline register
5789 R28: frame pointer (FP)
5790 R29: global pointer (GP)
5791 R30: link register (LP)
5792 R31: stack pointer (SP)
5793 PC: program counter (PC)
5795 ==> U-Boot will use R10 to hold a pointer to the global data
5797 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5798 or current versions of GCC may "optimize" the code too much.
5803 U-Boot runs in system state and uses physical addresses, i.e. the
5804 MMU is not used either for address mapping nor for memory protection.
5806 The available memory is mapped to fixed addresses using the memory
5807 controller. In this process, a contiguous block is formed for each
5808 memory type (Flash, SDRAM, SRAM), even when it consists of several
5809 physical memory banks.
5811 U-Boot is installed in the first 128 kB of the first Flash bank (on
5812 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5813 booting and sizing and initializing DRAM, the code relocates itself
5814 to the upper end of DRAM. Immediately below the U-Boot code some
5815 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5816 configuration setting]. Below that, a structure with global Board
5817 Info data is placed, followed by the stack (growing downward).
5819 Additionally, some exception handler code is copied to the low 8 kB
5820 of DRAM (0x00000000 ... 0x00001FFF).
5822 So a typical memory configuration with 16 MB of DRAM could look like
5825 0x0000 0000 Exception Vector code
5828 0x0000 2000 Free for Application Use
5834 0x00FB FF20 Monitor Stack (Growing downward)
5835 0x00FB FFAC Board Info Data and permanent copy of global data
5836 0x00FC 0000 Malloc Arena
5839 0x00FE 0000 RAM Copy of Monitor Code
5840 ... eventually: LCD or video framebuffer
5841 ... eventually: pRAM (Protected RAM - unchanged by reset)
5842 0x00FF FFFF [End of RAM]
5845 System Initialization:
5846 ----------------------
5848 In the reset configuration, U-Boot starts at the reset entry point
5849 (on most PowerPC systems at address 0x00000100). Because of the reset
5850 configuration for CS0# this is a mirror of the onboard Flash memory.
5851 To be able to re-map memory U-Boot then jumps to its link address.
5852 To be able to implement the initialization code in C, a (small!)
5853 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5854 which provide such a feature like MPC8xx or MPC8260), or in a locked
5855 part of the data cache. After that, U-Boot initializes the CPU core,
5856 the caches and the SIU.
5858 Next, all (potentially) available memory banks are mapped using a
5859 preliminary mapping. For example, we put them on 512 MB boundaries
5860 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5861 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5862 programmed for SDRAM access. Using the temporary configuration, a
5863 simple memory test is run that determines the size of the SDRAM
5866 When there is more than one SDRAM bank, and the banks are of
5867 different size, the largest is mapped first. For equal size, the first
5868 bank (CS2#) is mapped first. The first mapping is always for address
5869 0x00000000, with any additional banks following immediately to create
5870 contiguous memory starting from 0.
5872 Then, the monitor installs itself at the upper end of the SDRAM area
5873 and allocates memory for use by malloc() and for the global Board
5874 Info data; also, the exception vector code is copied to the low RAM
5875 pages, and the final stack is set up.
5877 Only after this relocation will you have a "normal" C environment;
5878 until that you are restricted in several ways, mostly because you are
5879 running from ROM, and because the code will have to be relocated to a
5883 U-Boot Porting Guide:
5884 ----------------------
5886 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5890 int main(int argc, char *argv[])
5892 sighandler_t no_more_time;
5894 signal(SIGALRM, no_more_time);
5895 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5897 if (available_money > available_manpower) {
5898 Pay consultant to port U-Boot;
5902 Download latest U-Boot source;
5904 Subscribe to u-boot mailing list;
5907 email("Hi, I am new to U-Boot, how do I get started?");
5910 Read the README file in the top level directory;
5911 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5912 Read applicable doc/*.README;
5913 Read the source, Luke;
5914 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5917 if (available_money > toLocalCurrency ($2500))
5920 Add a lot of aggravation and time;
5922 if (a similar board exists) { /* hopefully... */
5923 cp -a board/<similar> board/<myboard>
5924 cp include/configs/<similar>.h include/configs/<myboard>.h
5926 Create your own board support subdirectory;
5927 Create your own board include/configs/<myboard>.h file;
5929 Edit new board/<myboard> files
5930 Edit new include/configs/<myboard>.h
5935 Add / modify source code;
5939 email("Hi, I am having problems...");
5941 Send patch file to the U-Boot email list;
5942 if (reasonable critiques)
5943 Incorporate improvements from email list code review;
5945 Defend code as written;
5951 void no_more_time (int sig)
5960 All contributions to U-Boot should conform to the Linux kernel
5961 coding style; see the file "Documentation/CodingStyle" and the script
5962 "scripts/Lindent" in your Linux kernel source directory.
5964 Source files originating from a different project (for example the
5965 MTD subsystem) are generally exempt from these guidelines and are not
5966 reformated to ease subsequent migration to newer versions of those
5969 Please note that U-Boot is implemented in C (and to some small parts in
5970 Assembler); no C++ is used, so please do not use C++ style comments (//)
5973 Please also stick to the following formatting rules:
5974 - remove any trailing white space
5975 - use TAB characters for indentation and vertical alignment, not spaces
5976 - make sure NOT to use DOS '\r\n' line feeds
5977 - do not add more than 2 consecutive empty lines to source files
5978 - do not add trailing empty lines to source files
5980 Submissions which do not conform to the standards may be returned
5981 with a request to reformat the changes.
5987 Since the number of patches for U-Boot is growing, we need to
5988 establish some rules. Submissions which do not conform to these rules
5989 may be rejected, even when they contain important and valuable stuff.
5991 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5993 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5994 see http://lists.denx.de/mailman/listinfo/u-boot
5996 When you send a patch, please include the following information with
5999 * For bug fixes: a description of the bug and how your patch fixes
6000 this bug. Please try to include a way of demonstrating that the
6001 patch actually fixes something.
6003 * For new features: a description of the feature and your
6006 * A CHANGELOG entry as plaintext (separate from the patch)
6008 * For major contributions, your entry to the CREDITS file
6010 * When you add support for a new board, don't forget to add a
6011 maintainer e-mail address to the boards.cfg file, too.
6013 * If your patch adds new configuration options, don't forget to
6014 document these in the README file.
6016 * The patch itself. If you are using git (which is *strongly*
6017 recommended) you can easily generate the patch using the
6018 "git format-patch". If you then use "git send-email" to send it to
6019 the U-Boot mailing list, you will avoid most of the common problems
6020 with some other mail clients.
6022 If you cannot use git, use "diff -purN OLD NEW". If your version of
6023 diff does not support these options, then get the latest version of
6026 The current directory when running this command shall be the parent
6027 directory of the U-Boot source tree (i. e. please make sure that
6028 your patch includes sufficient directory information for the
6031 We prefer patches as plain text. MIME attachments are discouraged,
6032 and compressed attachments must not be used.
6034 * If one logical set of modifications affects or creates several
6035 files, all these changes shall be submitted in a SINGLE patch file.
6037 * Changesets that contain different, unrelated modifications shall be
6038 submitted as SEPARATE patches, one patch per changeset.
6043 * Before sending the patch, run the MAKEALL script on your patched
6044 source tree and make sure that no errors or warnings are reported
6045 for any of the boards.
6047 * Keep your modifications to the necessary minimum: A patch
6048 containing several unrelated changes or arbitrary reformats will be
6049 returned with a request to re-formatting / split it.
6051 * If you modify existing code, make sure that your new code does not
6052 add to the memory footprint of the code ;-) Small is beautiful!
6053 When adding new features, these should compile conditionally only
6054 (using #ifdef), and the resulting code with the new feature
6055 disabled must not need more memory than the old code without your
6058 * Remember that there is a size limit of 100 kB per message on the
6059 u-boot mailing list. Bigger patches will be moderated. If they are
6060 reasonable and not too big, they will be acknowledged. But patches
6061 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob