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 /pxa Files specific to Intel XScale PXA CPUs
145 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 /lib Architecture specific library files
147 /avr32 Files generic to AVR32 architecture
148 /cpu CPU specific files
149 /lib Architecture specific library files
150 /blackfin Files generic to Analog Devices Blackfin architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /m68k Files generic to m68k architecture
154 /cpu CPU specific files
155 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
156 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
157 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
158 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
159 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
160 /lib Architecture specific library files
161 /microblaze Files generic to microblaze architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /mips Files generic to MIPS architecture
165 /cpu CPU specific files
166 /mips32 Files specific to MIPS32 CPUs
167 /xburst Files specific to Ingenic XBurst CPUs
168 /lib Architecture specific library files
169 /nds32 Files generic to NDS32 architecture
170 /cpu CPU specific files
171 /n1213 Files specific to Andes Technology N1213 CPUs
172 /lib Architecture specific library files
173 /nios2 Files generic to Altera NIOS2 architecture
174 /cpu CPU specific files
175 /lib Architecture specific library files
176 /openrisc Files generic to OpenRISC architecture
177 /cpu CPU specific files
178 /lib Architecture specific library files
179 /powerpc Files generic to PowerPC architecture
180 /cpu CPU specific files
181 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
182 /mpc5xx Files specific to Freescale MPC5xx CPUs
183 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
184 /mpc8xx Files specific to Freescale MPC8xx CPUs
185 /mpc824x Files specific to Freescale MPC824x CPUs
186 /mpc8260 Files specific to Freescale MPC8260 CPUs
187 /mpc85xx Files specific to Freescale MPC85xx CPUs
188 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
189 /lib Architecture specific library files
190 /sh Files generic to SH architecture
191 /cpu CPU specific files
192 /sh2 Files specific to sh2 CPUs
193 /sh3 Files specific to sh3 CPUs
194 /sh4 Files specific to sh4 CPUs
195 /lib Architecture specific library files
196 /sparc Files generic to SPARC architecture
197 /cpu CPU specific files
198 /leon2 Files specific to Gaisler LEON2 SPARC CPU
199 /leon3 Files specific to Gaisler LEON3 SPARC CPU
200 /lib Architecture specific library files
201 /x86 Files generic to x86 architecture
202 /cpu CPU specific files
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /dts Contains Makefile for building internal U-Boot fdt.
211 /examples Example code for standalone applications, etc.
212 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
213 /include Header Files
214 /lib Files generic to all architectures
215 /libfdt Library files to support flattened device trees
216 /lzma Library files to support LZMA decompression
217 /lzo Library files to support LZO decompression
219 /post Power On Self Test
220 /spl Secondary Program Loader framework
221 /tools Tools to build S-Record or U-Boot images, etc.
223 Software Configuration:
224 =======================
226 Configuration is usually done using C preprocessor defines; the
227 rationale behind that is to avoid dead code whenever possible.
229 There are two classes of configuration variables:
231 * Configuration _OPTIONS_:
232 These are selectable by the user and have names beginning with
235 * Configuration _SETTINGS_:
236 These depend on the hardware etc. and should not be meddled with if
237 you don't know what you're doing; they have names beginning with
240 Later we will add a configuration tool - probably similar to or even
241 identical to what's used for the Linux kernel. Right now, we have to
242 do the configuration by hand, which means creating some symbolic
243 links and editing some configuration files. We use the TQM8xxL boards
247 Selection of Processor Architecture and Board Type:
248 ---------------------------------------------------
250 For all supported boards there are ready-to-use default
251 configurations available; just type "make <board_name>_config".
253 Example: For a TQM823L module type:
258 For the Cogent platform, you need to specify the CPU type as well;
259 e.g. "make cogent_mpc8xx_config". And also configure the cogent
260 directory according to the instructions in cogent/README.
263 Configuration Options:
264 ----------------------
266 Configuration depends on the combination of board and CPU type; all
267 such information is kept in a configuration file
268 "include/configs/<board_name>.h".
270 Example: For a TQM823L module, all configuration settings are in
271 "include/configs/TQM823L.h".
274 Many of the options are named exactly as the corresponding Linux
275 kernel configuration options. The intention is to make it easier to
276 build a config tool - later.
279 The following options need to be configured:
281 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
283 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
285 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
286 Define exactly one, e.g. CONFIG_ATSTK1002
288 - CPU Module Type: (if CONFIG_COGENT is defined)
289 Define exactly one of
291 --- FIXME --- not tested yet:
292 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
293 CONFIG_CMA287_23, CONFIG_CMA287_50
295 - Motherboard Type: (if CONFIG_COGENT is defined)
296 Define exactly one of
297 CONFIG_CMA101, CONFIG_CMA102
299 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
300 Define one or more of
303 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
304 Define one or more of
305 CONFIG_LCD_HEARTBEAT - update a character position on
306 the LCD display every second with
309 - Board flavour: (if CONFIG_MPC8260ADS is defined)
312 CONFIG_SYS_8260ADS - original MPC8260ADS
313 CONFIG_SYS_8266ADS - MPC8266ADS
314 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
315 CONFIG_SYS_8272ADS - MPC8272ADS
317 - Marvell Family Member
318 CONFIG_SYS_MVFS - define it if you want to enable
319 multiple fs option at one time
320 for marvell soc family
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
357 Specifies that the core is a 64-bit PowerPC implementation (implements
358 the "64" category of the Power ISA). This is necessary for ePAPR
359 compliance, among other possible reasons.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 CONFIG_SYS_PPC_E500_DEBUG_TLB
374 Enables a temporary TLB entry to be used during boot to work
375 around limitations in e500v1 and e500v2 external debugger
376 support. This reduces the portions of the boot code where
377 breakpoints and single stepping do not work. The value of this
378 symbol should be set to the TLB1 entry to be used for this
381 CONFIG_SYS_FSL_ERRATUM_A004510
383 Enables a workaround for erratum A004510. If set,
384 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
390 Defines one or two SoC revisions (low 8 bits of SVR)
391 for which the A004510 workaround should be applied.
393 The rest of SVR is either not relevant to the decision
394 of whether the erratum is present (e.g. p2040 versus
395 p2041) or is implied by the build target, which controls
396 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
398 See Freescale App Note 4493 for more information about
401 CONFIG_A003399_NOR_WORKAROUND
402 Enables a workaround for IFC erratum A003399. It is only
403 requred during NOR boot.
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
437 Freescale DDR driver in use. This type of DDR controller is
438 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
441 CONFIG_SYS_FSL_DDR_ADDR
442 Freescale DDR memory-mapped register base.
444 CONFIG_SYS_FSL_DDR_EMU
445 Specify emulator support for DDR. Some DDR features such as
446 deskew training are not available.
448 CONFIG_SYS_FSL_DDRC_GEN1
449 Freescale DDR1 controller.
451 CONFIG_SYS_FSL_DDRC_GEN2
452 Freescale DDR2 controller.
454 CONFIG_SYS_FSL_DDRC_GEN3
455 Freescale DDR3 controller.
457 CONFIG_SYS_FSL_DDRC_ARM_GEN3
458 Freescale DDR3 controller for ARM-based SoCs.
461 Board config to use DDR1. It can be enabled for SoCs with
462 Freescale DDR1 or DDR2 controllers, depending on the board
466 Board config to use DDR2. It can be eanbeld for SoCs with
467 Freescale DDR2 or DDR3 controllers, depending on the board
471 Board config to use DDR3. It can be enabled for SoCs with
472 Freescale DDR3 controllers.
474 CONFIG_SYS_FSL_IFC_BE
475 Defines the IFC controller register space as Big Endian
477 CONFIG_SYS_FSL_IFC_LE
478 Defines the IFC controller register space as Little Endian
480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
489 - Intel Monahans options:
490 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
492 Defines the Monahans run mode to oscillator
493 ratio. Valid values are 8, 16, 24, 31. The core
494 frequency is this value multiplied by 13 MHz.
496 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
498 Defines the Monahans turbo mode to oscillator
499 ratio. Valid values are 1 (default if undefined) and
500 2. The core frequency as calculated above is multiplied
504 CONFIG_SYS_INIT_SP_OFFSET
506 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
507 pointer. This is needed for the temporary stack before
510 CONFIG_SYS_MIPS_CACHE_MODE
512 Cache operation mode for the MIPS CPU.
513 See also arch/mips/include/asm/mipsregs.h.
515 CONF_CM_CACHABLE_NO_WA
518 CONF_CM_CACHABLE_NONCOHERENT
522 CONF_CM_CACHABLE_ACCELERATED
524 CONFIG_SYS_XWAY_EBU_BOOTCFG
526 Special option for Lantiq XWAY SoCs for booting from NOR flash.
527 See also arch/mips/cpu/mips32/start.S.
529 CONFIG_XWAY_SWAP_BYTES
531 Enable compilation of tools/xway-swap-bytes needed for Lantiq
532 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
533 be swapped if a flash programmer is used.
536 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
538 Select high exception vectors of the ARM core, e.g., do not
539 clear the V bit of the c1 register of CP15.
541 CONFIG_SYS_THUMB_BUILD
543 Use this flag to build U-Boot using the Thumb instruction
544 set for ARM architectures. Thumb instruction set provides
545 better code density. For ARM architectures that support
546 Thumb2 this flag will result in Thumb2 code generated by
549 CONFIG_ARM_ERRATA_716044
550 CONFIG_ARM_ERRATA_742230
551 CONFIG_ARM_ERRATA_743622
552 CONFIG_ARM_ERRATA_751472
554 If set, the workarounds for these ARM errata are applied early
555 during U-Boot startup. Note that these options force the
556 workarounds to be applied; no CPU-type/version detection
557 exists, unlike the similar options in the Linux kernel. Do not
558 set these options unless they apply!
563 The frequency of the timer returned by get_timer().
564 get_timer() must operate in milliseconds and this CONFIG
565 option must be set to 1000.
567 - Linux Kernel Interface:
570 U-Boot stores all clock information in Hz
571 internally. For binary compatibility with older Linux
572 kernels (which expect the clocks passed in the
573 bd_info data to be in MHz) the environment variable
574 "clocks_in_mhz" can be defined so that U-Boot
575 converts clock data to MHZ before passing it to the
577 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
578 "clocks_in_mhz=1" is automatically included in the
581 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
583 When transferring memsize parameter to linux, some versions
584 expect it to be in bytes, others in MB.
585 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
589 New kernel versions are expecting firmware settings to be
590 passed using flattened device trees (based on open firmware
594 * New libfdt-based support
595 * Adds the "fdt" command
596 * The bootm command automatically updates the fdt
598 OF_CPU - The proper name of the cpus node (only required for
599 MPC512X and MPC5xxx based boards).
600 OF_SOC - The proper name of the soc node (only required for
601 MPC512X and MPC5xxx based boards).
602 OF_TBCLK - The timebase frequency.
603 OF_STDOUT_PATH - The path to the console device
605 boards with QUICC Engines require OF_QE to set UCC MAC
608 CONFIG_OF_BOARD_SETUP
610 Board code has addition modification that it wants to make
611 to the flat device tree before handing it off to the kernel
615 This define fills in the correct boot CPU in the boot
616 param header, the default value is zero if undefined.
620 U-Boot can detect if an IDE device is present or not.
621 If not, and this new config option is activated, U-Boot
622 removes the ATA node from the DTS before booting Linux,
623 so the Linux IDE driver does not probe the device and
624 crash. This is needed for buggy hardware (uc101) where
625 no pull down resistor is connected to the signal IDE5V_DD7.
627 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
629 This setting is mandatory for all boards that have only one
630 machine type and must be used to specify the machine type
631 number as it appears in the ARM machine registry
632 (see http://www.arm.linux.org.uk/developer/machines/).
633 Only boards that have multiple machine types supported
634 in a single configuration file and the machine type is
635 runtime discoverable, do not have to use this setting.
637 - vxWorks boot parameters:
639 bootvx constructs a valid bootline using the following
640 environments variables: bootfile, ipaddr, serverip, hostname.
641 It loads the vxWorks image pointed bootfile.
643 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
644 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
645 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
646 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
648 CONFIG_SYS_VXWORKS_ADD_PARAMS
650 Add it at the end of the bootline. E.g "u=username pw=secret"
652 Note: If a "bootargs" environment is defined, it will overwride
653 the defaults discussed just above.
655 - Cache Configuration:
656 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
657 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
658 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
660 - Cache Configuration for ARM:
661 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
663 CONFIG_SYS_PL310_BASE - Physical base address of PL310
664 controller register space
669 Define this if you want support for Amba PrimeCell PL010 UARTs.
673 Define this if you want support for Amba PrimeCell PL011 UARTs.
677 If you have Amba PrimeCell PL011 UARTs, set this variable to
678 the clock speed of the UARTs.
682 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
683 define this to a list of base addresses for each (supported)
684 port. See e.g. include/configs/versatile.h
686 CONFIG_PL011_SERIAL_RLCR
688 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
689 have separate receive and transmit line control registers. Set
690 this variable to initialize the extra register.
692 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
694 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
695 boot loader that has already initialized the UART. Define this
696 variable to flush the UART at init time.
700 Depending on board, define exactly one serial port
701 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
702 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
703 console by defining CONFIG_8xx_CONS_NONE
705 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
706 port routines must be defined elsewhere
707 (i.e. serial_init(), serial_getc(), ...)
710 Enables console device for a color framebuffer. Needs following
711 defines (cf. smiLynxEM, i8042)
712 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
714 VIDEO_HW_RECTFILL graphic chip supports
717 VIDEO_HW_BITBLT graphic chip supports
718 bit-blit (cf. smiLynxEM)
719 VIDEO_VISIBLE_COLS visible pixel columns
721 VIDEO_VISIBLE_ROWS visible pixel rows
722 VIDEO_PIXEL_SIZE bytes per pixel
723 VIDEO_DATA_FORMAT graphic data format
724 (0-5, cf. cfb_console.c)
725 VIDEO_FB_ADRS framebuffer address
726 VIDEO_KBD_INIT_FCT keyboard int fct
727 (i.e. i8042_kbd_init())
728 VIDEO_TSTC_FCT test char fct
730 VIDEO_GETC_FCT get char fct
732 CONFIG_CONSOLE_CURSOR cursor drawing on/off
733 (requires blink timer
735 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
736 CONFIG_CONSOLE_TIME display time/date info in
738 (requires CONFIG_CMD_DATE)
739 CONFIG_VIDEO_LOGO display Linux logo in
741 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
742 linux_logo.h for logo.
743 Requires CONFIG_VIDEO_LOGO
744 CONFIG_CONSOLE_EXTRA_INFO
745 additional board info beside
748 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
749 a limited number of ANSI escape sequences (cursor control,
750 erase functions and limited graphics rendition control).
752 When CONFIG_CFB_CONSOLE is defined, video console is
753 default i/o. Serial console can be forced with
754 environment 'console=serial'.
756 When CONFIG_SILENT_CONSOLE is defined, all console
757 messages (by U-Boot and Linux!) can be silenced with
758 the "silent" environment variable. See
759 doc/README.silent for more information.
761 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
763 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
767 CONFIG_BAUDRATE - in bps
768 Select one of the baudrates listed in
769 CONFIG_SYS_BAUDRATE_TABLE, see below.
770 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
772 - Console Rx buffer length
773 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
774 the maximum receive buffer length for the SMC.
775 This option is actual only for 82xx and 8xx possible.
776 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
777 must be defined, to setup the maximum idle timeout for
780 - Pre-Console Buffer:
781 Prior to the console being initialised (i.e. serial UART
782 initialised etc) all console output is silently discarded.
783 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
784 buffer any console messages prior to the console being
785 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
786 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
787 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
788 bytes are output before the console is initialised, the
789 earlier bytes are discarded.
791 'Sane' compilers will generate smaller code if
792 CONFIG_PRE_CON_BUF_SZ is a power of 2
794 - Safe printf() functions
795 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
796 the printf() functions. These are defined in
797 include/vsprintf.h and include snprintf(), vsnprintf() and
798 so on. Code size increase is approximately 300-500 bytes.
799 If this option is not given then these functions will
800 silently discard their buffer size argument - this means
801 you are not getting any overflow checking in this case.
803 - Boot Delay: CONFIG_BOOTDELAY - in seconds
804 Delay before automatically booting the default image;
805 set to -1 to disable autoboot.
806 set to -2 to autoboot with no delay and not check for abort
807 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
809 See doc/README.autoboot for these options that
810 work with CONFIG_BOOTDELAY. None are required.
811 CONFIG_BOOT_RETRY_TIME
812 CONFIG_BOOT_RETRY_MIN
813 CONFIG_AUTOBOOT_KEYED
814 CONFIG_AUTOBOOT_PROMPT
815 CONFIG_AUTOBOOT_DELAY_STR
816 CONFIG_AUTOBOOT_STOP_STR
817 CONFIG_AUTOBOOT_DELAY_STR2
818 CONFIG_AUTOBOOT_STOP_STR2
819 CONFIG_ZERO_BOOTDELAY_CHECK
820 CONFIG_RESET_TO_RETRY
824 Only needed when CONFIG_BOOTDELAY is enabled;
825 define a command string that is automatically executed
826 when no character is read on the console interface
827 within "Boot Delay" after reset.
830 This can be used to pass arguments to the bootm
831 command. The value of CONFIG_BOOTARGS goes into the
832 environment value "bootargs".
834 CONFIG_RAMBOOT and CONFIG_NFSBOOT
835 The value of these goes into the environment as
836 "ramboot" and "nfsboot" respectively, and can be used
837 as a convenience, when switching between booting from
841 CONFIG_BOOTCOUNT_LIMIT
842 Implements a mechanism for detecting a repeating reboot
844 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
847 If no softreset save registers are found on the hardware
848 "bootcount" is stored in the environment. To prevent a
849 saveenv on all reboots, the environment variable
850 "upgrade_available" is used. If "upgrade_available" is
851 0, "bootcount" is always 0, if "upgrade_available" is
852 1 "bootcount" is incremented in the environment.
853 So the Userspace Applikation must set the "upgrade_available"
854 and "bootcount" variable to 0, if a boot was successfully.
859 When this option is #defined, the existence of the
860 environment variable "preboot" will be checked
861 immediately before starting the CONFIG_BOOTDELAY
862 countdown and/or running the auto-boot command resp.
863 entering interactive mode.
865 This feature is especially useful when "preboot" is
866 automatically generated or modified. For an example
867 see the LWMON board specific code: here "preboot" is
868 modified when the user holds down a certain
869 combination of keys on the (special) keyboard when
872 - Serial Download Echo Mode:
874 If defined to 1, all characters received during a
875 serial download (using the "loads" command) are
876 echoed back. This might be needed by some terminal
877 emulations (like "cu"), but may as well just take
878 time on others. This setting #define's the initial
879 value of the "loads_echo" environment variable.
881 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
883 Select one of the baudrates listed in
884 CONFIG_SYS_BAUDRATE_TABLE, see below.
887 Monitor commands can be included or excluded
888 from the build by using the #include files
889 <config_cmd_all.h> and #undef'ing unwanted
890 commands, or using <config_cmd_default.h>
891 and augmenting with additional #define's
894 The default command configuration includes all commands
895 except those marked below with a "*".
897 CONFIG_CMD_ASKENV * ask for env variable
898 CONFIG_CMD_BDI bdinfo
899 CONFIG_CMD_BEDBUG * Include BedBug Debugger
900 CONFIG_CMD_BMP * BMP support
901 CONFIG_CMD_BSP * Board specific commands
902 CONFIG_CMD_BOOTD bootd
903 CONFIG_CMD_CACHE * icache, dcache
904 CONFIG_CMD_CLK * clock command support
905 CONFIG_CMD_CONSOLE coninfo
906 CONFIG_CMD_CRC32 * crc32
907 CONFIG_CMD_DATE * support for RTC, date/time...
908 CONFIG_CMD_DHCP * DHCP support
909 CONFIG_CMD_DIAG * Diagnostics
910 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
911 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
912 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
913 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
914 CONFIG_CMD_DTT * Digital Therm and Thermostat
915 CONFIG_CMD_ECHO echo arguments
916 CONFIG_CMD_EDITENV edit env variable
917 CONFIG_CMD_EEPROM * EEPROM read/write support
918 CONFIG_CMD_ELF * bootelf, bootvx
919 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
920 CONFIG_CMD_ENV_FLAGS * display details about env flags
921 CONFIG_CMD_ENV_EXISTS * check existence of env variable
922 CONFIG_CMD_EXPORTENV * export the environment
923 CONFIG_CMD_EXT2 * ext2 command support
924 CONFIG_CMD_EXT4 * ext4 command support
925 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
926 that work for multiple fs types
927 CONFIG_CMD_SAVEENV saveenv
928 CONFIG_CMD_FDC * Floppy Disk Support
929 CONFIG_CMD_FAT * FAT command support
930 CONFIG_CMD_FDOS * Dos diskette Support
931 CONFIG_CMD_FLASH flinfo, erase, protect
932 CONFIG_CMD_FPGA FPGA device initialization support
933 CONFIG_CMD_FUSE * Device fuse support
934 CONFIG_CMD_GETTIME * Get time since boot
935 CONFIG_CMD_GO * the 'go' command (exec code)
936 CONFIG_CMD_GREPENV * search environment
937 CONFIG_CMD_HASH * calculate hash / digest
938 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
939 CONFIG_CMD_I2C * I2C serial bus support
940 CONFIG_CMD_IDE * IDE harddisk support
941 CONFIG_CMD_IMI iminfo
942 CONFIG_CMD_IMLS List all images found in NOR flash
943 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
944 CONFIG_CMD_IMMAP * IMMR dump support
945 CONFIG_CMD_IMPORTENV * import an environment
946 CONFIG_CMD_INI * import data from an ini file into the env
947 CONFIG_CMD_IRQ * irqinfo
948 CONFIG_CMD_ITEST Integer/string test of 2 values
949 CONFIG_CMD_JFFS2 * JFFS2 Support
950 CONFIG_CMD_KGDB * kgdb
951 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
952 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
954 CONFIG_CMD_LOADB loadb
955 CONFIG_CMD_LOADS loads
956 CONFIG_CMD_MD5SUM * print md5 message digest
957 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
958 CONFIG_CMD_MEMINFO * Display detailed memory information
959 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
961 CONFIG_CMD_MEMTEST * mtest
962 CONFIG_CMD_MISC Misc functions like sleep etc
963 CONFIG_CMD_MMC * MMC memory mapped support
964 CONFIG_CMD_MII * MII utility commands
965 CONFIG_CMD_MTDPARTS * MTD partition support
966 CONFIG_CMD_NAND * NAND support
967 CONFIG_CMD_NET bootp, tftpboot, rarpboot
968 CONFIG_CMD_NFS NFS support
969 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
970 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
971 CONFIG_CMD_PCI * pciinfo
972 CONFIG_CMD_PCMCIA * PCMCIA support
973 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
975 CONFIG_CMD_PORTIO * Port I/O
976 CONFIG_CMD_READ * Read raw data from partition
977 CONFIG_CMD_REGINFO * Register dump
978 CONFIG_CMD_RUN run command in env variable
979 CONFIG_CMD_SANDBOX * sb command to access sandbox features
980 CONFIG_CMD_SAVES * save S record dump
981 CONFIG_CMD_SCSI * SCSI Support
982 CONFIG_CMD_SDRAM * print SDRAM configuration information
983 (requires CONFIG_CMD_I2C)
984 CONFIG_CMD_SETGETDCR Support for DCR Register access
986 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
987 CONFIG_CMD_SHA1SUM * print sha1 memory digest
988 (requires CONFIG_CMD_MEMORY)
989 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
990 CONFIG_CMD_SOURCE "source" command Support
991 CONFIG_CMD_SPI * SPI serial bus support
992 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
993 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
994 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
995 CONFIG_CMD_TIMER * access to the system tick timer
996 CONFIG_CMD_USB * USB support
997 CONFIG_CMD_CDP * Cisco Discover Protocol support
998 CONFIG_CMD_MFSL * Microblaze FSL support
999 CONFIG_CMD_XIMG Load part of Multi Image
1002 EXAMPLE: If you want all functions except of network
1003 support you can write:
1005 #include "config_cmd_all.h"
1006 #undef CONFIG_CMD_NET
1009 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1011 Note: Don't enable the "icache" and "dcache" commands
1012 (configuration option CONFIG_CMD_CACHE) unless you know
1013 what you (and your U-Boot users) are doing. Data
1014 cache cannot be enabled on systems like the 8xx or
1015 8260 (where accesses to the IMMR region must be
1016 uncached), and it cannot be disabled on all other
1017 systems where we (mis-) use the data cache to hold an
1018 initial stack and some data.
1021 XXX - this list needs to get updated!
1023 - Regular expression support:
1025 If this variable is defined, U-Boot is linked against
1026 the SLRE (Super Light Regular Expression) library,
1027 which adds regex support to some commands, as for
1028 example "env grep" and "setexpr".
1032 If this variable is defined, U-Boot will use a device tree
1033 to configure its devices, instead of relying on statically
1034 compiled #defines in the board file. This option is
1035 experimental and only available on a few boards. The device
1036 tree is available in the global data as gd->fdt_blob.
1038 U-Boot needs to get its device tree from somewhere. This can
1039 be done using one of the two options below:
1042 If this variable is defined, U-Boot will embed a device tree
1043 binary in its image. This device tree file should be in the
1044 board directory and called <soc>-<board>.dts. The binary file
1045 is then picked up in board_init_f() and made available through
1046 the global data structure as gd->blob.
1049 If this variable is defined, U-Boot will build a device tree
1050 binary. It will be called u-boot.dtb. Architecture-specific
1051 code will locate it at run-time. Generally this works by:
1053 cat u-boot.bin u-boot.dtb >image.bin
1055 and in fact, U-Boot does this for you, creating a file called
1056 u-boot-dtb.bin which is useful in the common case. You can
1057 still use the individual files if you need something more
1062 If this variable is defined, it enables watchdog
1063 support for the SoC. There must be support in the SoC
1064 specific code for a watchdog. For the 8xx and 8260
1065 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1066 register. When supported for a specific SoC is
1067 available, then no further board specific code should
1068 be needed to use it.
1071 When using a watchdog circuitry external to the used
1072 SoC, then define this variable and provide board
1073 specific code for the "hw_watchdog_reset" function.
1076 CONFIG_VERSION_VARIABLE
1077 If this variable is defined, an environment variable
1078 named "ver" is created by U-Boot showing the U-Boot
1079 version as printed by the "version" command.
1080 Any change to this variable will be reverted at the
1085 When CONFIG_CMD_DATE is selected, the type of the RTC
1086 has to be selected, too. Define exactly one of the
1089 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1090 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1091 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1092 CONFIG_RTC_MC146818 - use MC146818 RTC
1093 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1094 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1095 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1096 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1097 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1098 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1099 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1100 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1103 Note that if the RTC uses I2C, then the I2C interface
1104 must also be configured. See I2C Support, below.
1107 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1109 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1110 chip-ngpio pairs that tell the PCA953X driver the number of
1111 pins supported by a particular chip.
1113 Note that if the GPIO device uses I2C, then the I2C interface
1114 must also be configured. See I2C Support, below.
1116 - Timestamp Support:
1118 When CONFIG_TIMESTAMP is selected, the timestamp
1119 (date and time) of an image is printed by image
1120 commands like bootm or iminfo. This option is
1121 automatically enabled when you select CONFIG_CMD_DATE .
1123 - Partition Labels (disklabels) Supported:
1124 Zero or more of the following:
1125 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1126 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1127 Intel architecture, USB sticks, etc.
1128 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1129 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1130 bootloader. Note 2TB partition limit; see
1132 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1134 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1135 CONFIG_CMD_SCSI) you must configure support for at
1136 least one non-MTD partition type as well.
1139 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1140 board configurations files but used nowhere!
1142 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1143 be performed by calling the function
1144 ide_set_reset(int reset)
1145 which has to be defined in a board specific file
1150 Set this to enable ATAPI support.
1155 Set this to enable support for disks larger than 137GB
1156 Also look at CONFIG_SYS_64BIT_LBA.
1157 Whithout these , LBA48 support uses 32bit variables and will 'only'
1158 support disks up to 2.1TB.
1160 CONFIG_SYS_64BIT_LBA:
1161 When enabled, makes the IDE subsystem use 64bit sector addresses.
1165 At the moment only there is only support for the
1166 SYM53C8XX SCSI controller; define
1167 CONFIG_SCSI_SYM53C8XX to enable it.
1169 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1170 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1171 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1172 maximum numbers of LUNs, SCSI ID's and target
1174 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1176 The environment variable 'scsidevs' is set to the number of
1177 SCSI devices found during the last scan.
1179 - NETWORK Support (PCI):
1181 Support for Intel 8254x/8257x gigabit chips.
1184 Utility code for direct access to the SPI bus on Intel 8257x.
1185 This does not do anything useful unless you set at least one
1186 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1188 CONFIG_E1000_SPI_GENERIC
1189 Allow generic access to the SPI bus on the Intel 8257x, for
1190 example with the "sspi" command.
1193 Management command for E1000 devices. When used on devices
1194 with SPI support you can reprogram the EEPROM from U-Boot.
1196 CONFIG_E1000_FALLBACK_MAC
1197 default MAC for empty EEPROM after production.
1200 Support for Intel 82557/82559/82559ER chips.
1201 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1202 write routine for first time initialisation.
1205 Support for Digital 2114x chips.
1206 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1207 modem chip initialisation (KS8761/QS6611).
1210 Support for National dp83815 chips.
1213 Support for National dp8382[01] gigabit chips.
1215 - NETWORK Support (other):
1217 CONFIG_DRIVER_AT91EMAC
1218 Support for AT91RM9200 EMAC.
1221 Define this to use reduced MII inteface
1223 CONFIG_DRIVER_AT91EMAC_QUIET
1224 If this defined, the driver is quiet.
1225 The driver doen't show link status messages.
1227 CONFIG_CALXEDA_XGMAC
1228 Support for the Calxeda XGMAC device
1231 Support for SMSC's LAN91C96 chips.
1233 CONFIG_LAN91C96_BASE
1234 Define this to hold the physical address
1235 of the LAN91C96's I/O space
1237 CONFIG_LAN91C96_USE_32_BIT
1238 Define this to enable 32 bit addressing
1241 Support for SMSC's LAN91C111 chip
1243 CONFIG_SMC91111_BASE
1244 Define this to hold the physical address
1245 of the device (I/O space)
1247 CONFIG_SMC_USE_32_BIT
1248 Define this if data bus is 32 bits
1250 CONFIG_SMC_USE_IOFUNCS
1251 Define this to use i/o functions instead of macros
1252 (some hardware wont work with macros)
1254 CONFIG_DRIVER_TI_EMAC
1255 Support for davinci emac
1257 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1258 Define this if you have more then 3 PHYs.
1261 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1263 CONFIG_FTGMAC100_EGIGA
1264 Define this to use GE link update with gigabit PHY.
1265 Define this if FTGMAC100 is connected to gigabit PHY.
1266 If your system has 10/100 PHY only, it might not occur
1267 wrong behavior. Because PHY usually return timeout or
1268 useless data when polling gigabit status and gigabit
1269 control registers. This behavior won't affect the
1270 correctnessof 10/100 link speed update.
1273 Support for SMSC's LAN911x and LAN921x chips
1276 Define this to hold the physical address
1277 of the device (I/O space)
1279 CONFIG_SMC911X_32_BIT
1280 Define this if data bus is 32 bits
1282 CONFIG_SMC911X_16_BIT
1283 Define this if data bus is 16 bits. If your processor
1284 automatically converts one 32 bit word to two 16 bit
1285 words you may also try CONFIG_SMC911X_32_BIT.
1288 Support for Renesas on-chip Ethernet controller
1290 CONFIG_SH_ETHER_USE_PORT
1291 Define the number of ports to be used
1293 CONFIG_SH_ETHER_PHY_ADDR
1294 Define the ETH PHY's address
1296 CONFIG_SH_ETHER_CACHE_WRITEBACK
1297 If this option is set, the driver enables cache flush.
1301 Support TPM devices.
1304 Support for i2c bus TPM devices. Only one device
1305 per system is supported at this time.
1307 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1308 Define the the i2c bus number for the TPM device
1310 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1311 Define the TPM's address on the i2c bus
1313 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1314 Define the burst count bytes upper limit
1316 CONFIG_TPM_ATMEL_TWI
1317 Support for Atmel TWI TPM device. Requires I2C support.
1320 Support for generic parallel port TPM devices. Only one device
1321 per system is supported at this time.
1323 CONFIG_TPM_TIS_BASE_ADDRESS
1324 Base address where the generic TPM device is mapped
1325 to. Contemporary x86 systems usually map it at
1329 Add tpm monitor functions.
1330 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1331 provides monitor access to authorized functions.
1334 Define this to enable the TPM support library which provides
1335 functional interfaces to some TPM commands.
1336 Requires support for a TPM device.
1338 CONFIG_TPM_AUTH_SESSIONS
1339 Define this to enable authorized functions in the TPM library.
1340 Requires CONFIG_TPM and CONFIG_SHA1.
1343 At the moment only the UHCI host controller is
1344 supported (PIP405, MIP405, MPC5200); define
1345 CONFIG_USB_UHCI to enable it.
1346 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1347 and define CONFIG_USB_STORAGE to enable the USB
1350 Supported are USB Keyboards and USB Floppy drives
1352 MPC5200 USB requires additional defines:
1354 for 528 MHz Clock: 0x0001bbbb
1358 for differential drivers: 0x00001000
1359 for single ended drivers: 0x00005000
1360 for differential drivers on PSC3: 0x00000100
1361 for single ended drivers on PSC3: 0x00004100
1362 CONFIG_SYS_USB_EVENT_POLL
1363 May be defined to allow interrupt polling
1364 instead of using asynchronous interrupts
1366 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1367 txfilltuning field in the EHCI controller on reset.
1369 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1370 interval for usb hub power-on delay.(minimum 100msec)
1373 Define the below if you wish to use the USB console.
1374 Once firmware is rebuilt from a serial console issue the
1375 command "setenv stdin usbtty; setenv stdout usbtty" and
1376 attach your USB cable. The Unix command "dmesg" should print
1377 it has found a new device. The environment variable usbtty
1378 can be set to gserial or cdc_acm to enable your device to
1379 appear to a USB host as a Linux gserial device or a
1380 Common Device Class Abstract Control Model serial device.
1381 If you select usbtty = gserial you should be able to enumerate
1383 # modprobe usbserial vendor=0xVendorID product=0xProductID
1384 else if using cdc_acm, simply setting the environment
1385 variable usbtty to be cdc_acm should suffice. The following
1386 might be defined in YourBoardName.h
1389 Define this to build a UDC device
1392 Define this to have a tty type of device available to
1393 talk to the UDC device
1396 Define this to enable the high speed support for usb
1397 device and usbtty. If this feature is enabled, a routine
1398 int is_usbd_high_speed(void)
1399 also needs to be defined by the driver to dynamically poll
1400 whether the enumeration has succeded at high speed or full
1403 CONFIG_SYS_CONSOLE_IS_IN_ENV
1404 Define this if you want stdin, stdout &/or stderr to
1408 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1409 Derive USB clock from external clock "blah"
1410 - CONFIG_SYS_USB_EXTC_CLK 0x02
1412 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1413 Derive USB clock from brgclk
1414 - CONFIG_SYS_USB_BRG_CLK 0x04
1416 If you have a USB-IF assigned VendorID then you may wish to
1417 define your own vendor specific values either in BoardName.h
1418 or directly in usbd_vendor_info.h. If you don't define
1419 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1420 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1421 should pretend to be a Linux device to it's target host.
1423 CONFIG_USBD_MANUFACTURER
1424 Define this string as the name of your company for
1425 - CONFIG_USBD_MANUFACTURER "my company"
1427 CONFIG_USBD_PRODUCT_NAME
1428 Define this string as the name of your product
1429 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1431 CONFIG_USBD_VENDORID
1432 Define this as your assigned Vendor ID from the USB
1433 Implementors Forum. This *must* be a genuine Vendor ID
1434 to avoid polluting the USB namespace.
1435 - CONFIG_USBD_VENDORID 0xFFFF
1437 CONFIG_USBD_PRODUCTID
1438 Define this as the unique Product ID
1440 - CONFIG_USBD_PRODUCTID 0xFFFF
1442 Some USB device drivers may need to check USB cable attachment.
1443 In this case you can enable following config in BoardName.h:
1444 CONFIG_USB_CABLE_CHECK
1445 This enables function definition:
1446 - usb_cable_connected() in include/usb.h
1447 Implementation of this function is board-specific.
1449 - ULPI Layer Support:
1450 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1451 the generic ULPI layer. The generic layer accesses the ULPI PHY
1452 via the platform viewport, so you need both the genric layer and
1453 the viewport enabled. Currently only Chipidea/ARC based
1454 viewport is supported.
1455 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1456 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1457 If your ULPI phy needs a different reference clock than the
1458 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1459 the appropriate value in Hz.
1462 The MMC controller on the Intel PXA is supported. To
1463 enable this define CONFIG_MMC. The MMC can be
1464 accessed from the boot prompt by mapping the device
1465 to physical memory similar to flash. Command line is
1466 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1467 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1470 Support for Renesas on-chip MMCIF controller
1472 CONFIG_SH_MMCIF_ADDR
1473 Define the base address of MMCIF registers
1476 Define the clock frequency for MMCIF
1478 - USB Device Firmware Update (DFU) class support:
1480 This enables the USB portion of the DFU USB class
1483 This enables the command "dfu" which is used to have
1484 U-Boot create a DFU class device via USB. This command
1485 requires that the "dfu_alt_info" environment variable be
1486 set and define the alt settings to expose to the host.
1489 This enables support for exposing (e)MMC devices via DFU.
1492 This enables support for exposing NAND devices via DFU.
1495 This enables support for exposing RAM via DFU.
1496 Note: DFU spec refer to non-volatile memory usage, but
1497 allow usages beyond the scope of spec - here RAM usage,
1498 one that would help mostly the developer.
1500 CONFIG_SYS_DFU_DATA_BUF_SIZE
1501 Dfu transfer uses a buffer before writing data to the
1502 raw storage device. Make the size (in bytes) of this buffer
1503 configurable. The size of this buffer is also configurable
1504 through the "dfu_bufsiz" environment variable.
1506 CONFIG_SYS_DFU_MAX_FILE_SIZE
1507 When updating files rather than the raw storage device,
1508 we use a static buffer to copy the file into and then write
1509 the buffer once we've been given the whole file. Define
1510 this to the maximum filesize (in bytes) for the buffer.
1511 Default is 4 MiB if undefined.
1513 - Journaling Flash filesystem support:
1514 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1515 CONFIG_JFFS2_NAND_DEV
1516 Define these for a default partition on a NAND device
1518 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1519 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1520 Define these for a default partition on a NOR device
1522 CONFIG_SYS_JFFS_CUSTOM_PART
1523 Define this to create an own partition. You have to provide a
1524 function struct part_info* jffs2_part_info(int part_num)
1526 If you define only one JFFS2 partition you may also want to
1527 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1528 to disable the command chpart. This is the default when you
1529 have not defined a custom partition
1531 - FAT(File Allocation Table) filesystem write function support:
1534 Define this to enable support for saving memory data as a
1535 file in FAT formatted partition.
1537 This will also enable the command "fatwrite" enabling the
1538 user to write files to FAT.
1540 CBFS (Coreboot Filesystem) support
1543 Define this to enable support for reading from a Coreboot
1544 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1550 Define this to enable standard (PC-Style) keyboard
1554 Standard PC keyboard driver with US (is default) and
1555 GERMAN key layout (switch via environment 'keymap=de') support.
1556 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1557 for cfb_console. Supports cursor blinking.
1560 Enables a Chrome OS keyboard using the CROS_EC interface.
1561 This uses CROS_EC to communicate with a second microcontroller
1562 which provides key scans on request.
1567 Define this to enable video support (for output to
1570 CONFIG_VIDEO_CT69000
1572 Enable Chips & Technologies 69000 Video chip
1574 CONFIG_VIDEO_SMI_LYNXEM
1575 Enable Silicon Motion SMI 712/710/810 Video chip. The
1576 video output is selected via environment 'videoout'
1577 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1580 For the CT69000 and SMI_LYNXEM drivers, videomode is
1581 selected via environment 'videomode'. Two different ways
1583 - "videomode=num" 'num' is a standard LiLo mode numbers.
1584 Following standard modes are supported (* is default):
1586 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1587 -------------+---------------------------------------------
1588 8 bits | 0x301* 0x303 0x305 0x161 0x307
1589 15 bits | 0x310 0x313 0x316 0x162 0x319
1590 16 bits | 0x311 0x314 0x317 0x163 0x31A
1591 24 bits | 0x312 0x315 0x318 ? 0x31B
1592 -------------+---------------------------------------------
1593 (i.e. setenv videomode 317; saveenv; reset;)
1595 - "videomode=bootargs" all the video parameters are parsed
1596 from the bootargs. (See drivers/video/videomodes.c)
1599 CONFIG_VIDEO_SED13806
1600 Enable Epson SED13806 driver. This driver supports 8bpp
1601 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1602 or CONFIG_VIDEO_SED13806_16BPP
1605 Enable the Freescale DIU video driver. Reference boards for
1606 SOCs that have a DIU should define this macro to enable DIU
1607 support, and should also define these other macros:
1613 CONFIG_VIDEO_SW_CURSOR
1614 CONFIG_VGA_AS_SINGLE_DEVICE
1616 CONFIG_VIDEO_BMP_LOGO
1618 The DIU driver will look for the 'video-mode' environment
1619 variable, and if defined, enable the DIU as a console during
1620 boot. See the documentation file README.video for a
1621 description of this variable.
1625 Enable the VGA video / BIOS for x86. The alternative if you
1626 are using coreboot is to use the coreboot frame buffer
1633 Define this to enable a custom keyboard support.
1634 This simply calls drv_keyboard_init() which must be
1635 defined in your board-specific files.
1636 The only board using this so far is RBC823.
1638 - LCD Support: CONFIG_LCD
1640 Define this to enable LCD support (for output to LCD
1641 display); also select one of the supported displays
1642 by defining one of these:
1646 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1648 CONFIG_NEC_NL6448AC33:
1650 NEC NL6448AC33-18. Active, color, single scan.
1652 CONFIG_NEC_NL6448BC20
1654 NEC NL6448BC20-08. 6.5", 640x480.
1655 Active, color, single scan.
1657 CONFIG_NEC_NL6448BC33_54
1659 NEC NL6448BC33-54. 10.4", 640x480.
1660 Active, color, single scan.
1664 Sharp 320x240. Active, color, single scan.
1665 It isn't 16x9, and I am not sure what it is.
1667 CONFIG_SHARP_LQ64D341
1669 Sharp LQ64D341 display, 640x480.
1670 Active, color, single scan.
1674 HLD1045 display, 640x480.
1675 Active, color, single scan.
1679 Optrex CBL50840-2 NF-FW 99 22 M5
1681 Hitachi LMG6912RPFC-00T
1685 320x240. Black & white.
1687 Normally display is black on white background; define
1688 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1690 CONFIG_LCD_ALIGNMENT
1692 Normally the LCD is page-aligned (tyically 4KB). If this is
1693 defined then the LCD will be aligned to this value instead.
1694 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1695 here, since it is cheaper to change data cache settings on
1696 a per-section basis.
1698 CONFIG_CONSOLE_SCROLL_LINES
1700 When the console need to be scrolled, this is the number of
1701 lines to scroll by. It defaults to 1. Increasing this makes
1702 the console jump but can help speed up operation when scrolling
1707 Support drawing of RLE8-compressed bitmaps on the LCD.
1711 Enables an 'i2c edid' command which can read EDID
1712 information over I2C from an attached LCD display.
1714 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1716 If this option is set, the environment is checked for
1717 a variable "splashimage". If found, the usual display
1718 of logo, copyright and system information on the LCD
1719 is suppressed and the BMP image at the address
1720 specified in "splashimage" is loaded instead. The
1721 console is redirected to the "nulldev", too. This
1722 allows for a "silent" boot where a splash screen is
1723 loaded very quickly after power-on.
1725 CONFIG_SPLASHIMAGE_GUARD
1727 If this option is set, then U-Boot will prevent the environment
1728 variable "splashimage" from being set to a problematic address
1729 (see README.displaying-bmps and README.arm-unaligned-accesses).
1730 This option is useful for targets where, due to alignment
1731 restrictions, an improperly aligned BMP image will cause a data
1732 abort. If you think you will not have problems with unaligned
1733 accesses (for example because your toolchain prevents them)
1734 there is no need to set this option.
1736 CONFIG_SPLASH_SCREEN_ALIGN
1738 If this option is set the splash image can be freely positioned
1739 on the screen. Environment variable "splashpos" specifies the
1740 position as "x,y". If a positive number is given it is used as
1741 number of pixel from left/top. If a negative number is given it
1742 is used as number of pixel from right/bottom. You can also
1743 specify 'm' for centering the image.
1746 setenv splashpos m,m
1747 => image at center of screen
1749 setenv splashpos 30,20
1750 => image at x = 30 and y = 20
1752 setenv splashpos -10,m
1753 => vertically centered image
1754 at x = dspWidth - bmpWidth - 9
1756 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1758 If this option is set, additionally to standard BMP
1759 images, gzipped BMP images can be displayed via the
1760 splashscreen support or the bmp command.
1762 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1764 If this option is set, 8-bit RLE compressed BMP images
1765 can be displayed via the splashscreen support or the
1768 - Do compresssing for memory range:
1771 If this option is set, it would use zlib deflate method
1772 to compress the specified memory at its best effort.
1774 - Compression support:
1777 Enabled by default to support gzip compressed images.
1781 If this option is set, support for bzip2 compressed
1782 images is included. If not, only uncompressed and gzip
1783 compressed images are supported.
1785 NOTE: the bzip2 algorithm requires a lot of RAM, so
1786 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1791 If this option is set, support for lzma compressed
1794 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1795 requires an amount of dynamic memory that is given by the
1798 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1800 Where lc and lp stand for, respectively, Literal context bits
1801 and Literal pos bits.
1803 This value is upper-bounded by 14MB in the worst case. Anyway,
1804 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1805 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1806 a very small buffer.
1808 Use the lzmainfo tool to determinate the lc and lp values and
1809 then calculate the amount of needed dynamic memory (ensuring
1810 the appropriate CONFIG_SYS_MALLOC_LEN value).
1814 If this option is set, support for LZO compressed images
1820 The address of PHY on MII bus.
1822 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1824 The clock frequency of the MII bus
1828 If this option is set, support for speed/duplex
1829 detection of gigabit PHY is included.
1831 CONFIG_PHY_RESET_DELAY
1833 Some PHY like Intel LXT971A need extra delay after
1834 reset before any MII register access is possible.
1835 For such PHY, set this option to the usec delay
1836 required. (minimum 300usec for LXT971A)
1838 CONFIG_PHY_CMD_DELAY (ppc4xx)
1840 Some PHY like Intel LXT971A need extra delay after
1841 command issued before MII status register can be read
1851 Define a default value for Ethernet address to use
1852 for the respective Ethernet interface, in case this
1853 is not determined automatically.
1858 Define a default value for the IP address to use for
1859 the default Ethernet interface, in case this is not
1860 determined through e.g. bootp.
1861 (Environment variable "ipaddr")
1863 - Server IP address:
1866 Defines a default value for the IP address of a TFTP
1867 server to contact when using the "tftboot" command.
1868 (Environment variable "serverip")
1870 CONFIG_KEEP_SERVERADDR
1872 Keeps the server's MAC address, in the env 'serveraddr'
1873 for passing to bootargs (like Linux's netconsole option)
1875 - Gateway IP address:
1878 Defines a default value for the IP address of the
1879 default router where packets to other networks are
1881 (Environment variable "gatewayip")
1886 Defines a default value for the subnet mask (or
1887 routing prefix) which is used to determine if an IP
1888 address belongs to the local subnet or needs to be
1889 forwarded through a router.
1890 (Environment variable "netmask")
1892 - Multicast TFTP Mode:
1895 Defines whether you want to support multicast TFTP as per
1896 rfc-2090; for example to work with atftp. Lets lots of targets
1897 tftp down the same boot image concurrently. Note: the Ethernet
1898 driver in use must provide a function: mcast() to join/leave a
1901 - BOOTP Recovery Mode:
1902 CONFIG_BOOTP_RANDOM_DELAY
1904 If you have many targets in a network that try to
1905 boot using BOOTP, you may want to avoid that all
1906 systems send out BOOTP requests at precisely the same
1907 moment (which would happen for instance at recovery
1908 from a power failure, when all systems will try to
1909 boot, thus flooding the BOOTP server. Defining
1910 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1911 inserted before sending out BOOTP requests. The
1912 following delays are inserted then:
1914 1st BOOTP request: delay 0 ... 1 sec
1915 2nd BOOTP request: delay 0 ... 2 sec
1916 3rd BOOTP request: delay 0 ... 4 sec
1918 BOOTP requests: delay 0 ... 8 sec
1920 - DHCP Advanced Options:
1921 You can fine tune the DHCP functionality by defining
1922 CONFIG_BOOTP_* symbols:
1924 CONFIG_BOOTP_SUBNETMASK
1925 CONFIG_BOOTP_GATEWAY
1926 CONFIG_BOOTP_HOSTNAME
1927 CONFIG_BOOTP_NISDOMAIN
1928 CONFIG_BOOTP_BOOTPATH
1929 CONFIG_BOOTP_BOOTFILESIZE
1932 CONFIG_BOOTP_SEND_HOSTNAME
1933 CONFIG_BOOTP_NTPSERVER
1934 CONFIG_BOOTP_TIMEOFFSET
1935 CONFIG_BOOTP_VENDOREX
1936 CONFIG_BOOTP_MAY_FAIL
1938 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1939 environment variable, not the BOOTP server.
1941 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1942 after the configured retry count, the call will fail
1943 instead of starting over. This can be used to fail over
1944 to Link-local IP address configuration if the DHCP server
1947 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1948 serverip from a DHCP server, it is possible that more
1949 than one DNS serverip is offered to the client.
1950 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1951 serverip will be stored in the additional environment
1952 variable "dnsip2". The first DNS serverip is always
1953 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1956 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1957 to do a dynamic update of a DNS server. To do this, they
1958 need the hostname of the DHCP requester.
1959 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1960 of the "hostname" environment variable is passed as
1961 option 12 to the DHCP server.
1963 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1965 A 32bit value in microseconds for a delay between
1966 receiving a "DHCP Offer" and sending the "DHCP Request".
1967 This fixes a problem with certain DHCP servers that don't
1968 respond 100% of the time to a "DHCP request". E.g. On an
1969 AT91RM9200 processor running at 180MHz, this delay needed
1970 to be *at least* 15,000 usec before a Windows Server 2003
1971 DHCP server would reply 100% of the time. I recommend at
1972 least 50,000 usec to be safe. The alternative is to hope
1973 that one of the retries will be successful but note that
1974 the DHCP timeout and retry process takes a longer than
1977 - Link-local IP address negotiation:
1978 Negotiate with other link-local clients on the local network
1979 for an address that doesn't require explicit configuration.
1980 This is especially useful if a DHCP server cannot be guaranteed
1981 to exist in all environments that the device must operate.
1983 See doc/README.link-local for more information.
1986 CONFIG_CDP_DEVICE_ID
1988 The device id used in CDP trigger frames.
1990 CONFIG_CDP_DEVICE_ID_PREFIX
1992 A two character string which is prefixed to the MAC address
1997 A printf format string which contains the ascii name of
1998 the port. Normally is set to "eth%d" which sets
1999 eth0 for the first Ethernet, eth1 for the second etc.
2001 CONFIG_CDP_CAPABILITIES
2003 A 32bit integer which indicates the device capabilities;
2004 0x00000010 for a normal host which does not forwards.
2008 An ascii string containing the version of the software.
2012 An ascii string containing the name of the platform.
2016 A 32bit integer sent on the trigger.
2018 CONFIG_CDP_POWER_CONSUMPTION
2020 A 16bit integer containing the power consumption of the
2021 device in .1 of milliwatts.
2023 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2025 A byte containing the id of the VLAN.
2027 - Status LED: CONFIG_STATUS_LED
2029 Several configurations allow to display the current
2030 status using a LED. For instance, the LED will blink
2031 fast while running U-Boot code, stop blinking as
2032 soon as a reply to a BOOTP request was received, and
2033 start blinking slow once the Linux kernel is running
2034 (supported by a status LED driver in the Linux
2035 kernel). Defining CONFIG_STATUS_LED enables this
2041 The status LED can be connected to a GPIO pin.
2042 In such cases, the gpio_led driver can be used as a
2043 status LED backend implementation. Define CONFIG_GPIO_LED
2044 to include the gpio_led driver in the U-Boot binary.
2046 CONFIG_GPIO_LED_INVERTED_TABLE
2047 Some GPIO connected LEDs may have inverted polarity in which
2048 case the GPIO high value corresponds to LED off state and
2049 GPIO low value corresponds to LED on state.
2050 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2051 with a list of GPIO LEDs that have inverted polarity.
2053 - CAN Support: CONFIG_CAN_DRIVER
2055 Defining CONFIG_CAN_DRIVER enables CAN driver support
2056 on those systems that support this (optional)
2057 feature, like the TQM8xxL modules.
2059 - I2C Support: CONFIG_SYS_I2C
2061 This enable the NEW i2c subsystem, and will allow you to use
2062 i2c commands at the u-boot command line (as long as you set
2063 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2064 based realtime clock chips or other i2c devices. See
2065 common/cmd_i2c.c for a description of the command line
2068 ported i2c driver to the new framework:
2069 - drivers/i2c/soft_i2c.c:
2070 - activate first bus with CONFIG_SYS_I2C_SOFT define
2071 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2072 for defining speed and slave address
2073 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2074 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2075 for defining speed and slave address
2076 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2077 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2078 for defining speed and slave address
2079 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2080 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2081 for defining speed and slave address
2083 - drivers/i2c/fsl_i2c.c:
2084 - activate i2c driver with CONFIG_SYS_I2C_FSL
2085 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2086 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2087 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2089 - If your board supports a second fsl i2c bus, define
2090 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2091 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2092 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2095 - drivers/i2c/tegra_i2c.c:
2096 - activate this driver with CONFIG_SYS_I2C_TEGRA
2097 - This driver adds 4 i2c buses with a fix speed from
2098 100000 and the slave addr 0!
2100 - drivers/i2c/ppc4xx_i2c.c
2101 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2102 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2103 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2105 - drivers/i2c/i2c_mxc.c
2106 - activate this driver with CONFIG_SYS_I2C_MXC
2107 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2108 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2109 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2110 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2111 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2112 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2113 If thoses defines are not set, default value is 100000
2114 for speed, and 0 for slave.
2116 - drivers/i2c/rcar_i2c.c:
2117 - activate this driver with CONFIG_SYS_I2C_RCAR
2118 - This driver adds 4 i2c buses
2120 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2121 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2122 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2123 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2124 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2125 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2126 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2127 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2128 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2130 - drivers/i2c/sh_i2c.c:
2131 - activate this driver with CONFIG_SYS_I2C_SH
2132 - This driver adds from 2 to 5 i2c buses
2134 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2135 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2136 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2137 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2138 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2139 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2140 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2141 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2142 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2143 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2144 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2145 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2146 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2148 - drivers/i2c/omap24xx_i2c.c
2149 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2150 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2151 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2152 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2153 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2154 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2155 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2156 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2157 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2158 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2159 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2161 - drivers/i2c/zynq_i2c.c
2162 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2163 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2164 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2166 - drivers/i2c/s3c24x0_i2c.c:
2167 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2168 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2169 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2170 with a fix speed from 100000 and the slave addr 0!
2174 CONFIG_SYS_NUM_I2C_BUSES
2175 Hold the number of i2c busses you want to use. If you
2176 don't use/have i2c muxes on your i2c bus, this
2177 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2180 CONFIG_SYS_I2C_DIRECT_BUS
2181 define this, if you don't use i2c muxes on your hardware.
2182 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2185 CONFIG_SYS_I2C_MAX_HOPS
2186 define how many muxes are maximal consecutively connected
2187 on one i2c bus. If you not use i2c muxes, omit this
2190 CONFIG_SYS_I2C_BUSES
2191 hold a list of busses you want to use, only used if
2192 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2193 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2194 CONFIG_SYS_NUM_I2C_BUSES = 9:
2196 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2197 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2198 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2199 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2200 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2201 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2202 {1, {I2C_NULL_HOP}}, \
2203 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2204 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2208 bus 0 on adapter 0 without a mux
2209 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2210 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2211 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2212 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2213 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2214 bus 6 on adapter 1 without a mux
2215 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2216 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2218 If you do not have i2c muxes on your board, omit this define.
2220 - Legacy I2C Support: CONFIG_HARD_I2C
2222 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2223 provides the following compelling advantages:
2225 - more than one i2c adapter is usable
2226 - approved multibus support
2227 - better i2c mux support
2229 ** Please consider updating your I2C driver now. **
2231 These enable legacy I2C serial bus commands. Defining
2232 CONFIG_HARD_I2C will include the appropriate I2C driver
2233 for the selected CPU.
2235 This will allow you to use i2c commands at the u-boot
2236 command line (as long as you set CONFIG_CMD_I2C in
2237 CONFIG_COMMANDS) and communicate with i2c based realtime
2238 clock chips. See common/cmd_i2c.c for a description of the
2239 command line interface.
2241 CONFIG_HARD_I2C selects a hardware I2C controller.
2243 There are several other quantities that must also be
2244 defined when you define CONFIG_HARD_I2C.
2246 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2247 to be the frequency (in Hz) at which you wish your i2c bus
2248 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2249 the CPU's i2c node address).
2251 Now, the u-boot i2c code for the mpc8xx
2252 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2253 and so its address should therefore be cleared to 0 (See,
2254 eg, MPC823e User's Manual p.16-473). So, set
2255 CONFIG_SYS_I2C_SLAVE to 0.
2257 CONFIG_SYS_I2C_INIT_MPC5XXX
2259 When a board is reset during an i2c bus transfer
2260 chips might think that the current transfer is still
2261 in progress. Reset the slave devices by sending start
2262 commands until the slave device responds.
2264 That's all that's required for CONFIG_HARD_I2C.
2266 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2267 then the following macros need to be defined (examples are
2268 from include/configs/lwmon.h):
2272 (Optional). Any commands necessary to enable the I2C
2273 controller or configure ports.
2275 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2279 (Only for MPC8260 CPU). The I/O port to use (the code
2280 assumes both bits are on the same port). Valid values
2281 are 0..3 for ports A..D.
2285 The code necessary to make the I2C data line active
2286 (driven). If the data line is open collector, this
2289 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2293 The code necessary to make the I2C data line tri-stated
2294 (inactive). If the data line is open collector, this
2297 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2301 Code that returns true if the I2C data line is high,
2304 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2308 If <bit> is true, sets the I2C data line high. If it
2309 is false, it clears it (low).
2311 eg: #define I2C_SDA(bit) \
2312 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2313 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2317 If <bit> is true, sets the I2C clock line high. If it
2318 is false, it clears it (low).
2320 eg: #define I2C_SCL(bit) \
2321 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2322 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2326 This delay is invoked four times per clock cycle so this
2327 controls the rate of data transfer. The data rate thus
2328 is 1 / (I2C_DELAY * 4). Often defined to be something
2331 #define I2C_DELAY udelay(2)
2333 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2335 If your arch supports the generic GPIO framework (asm/gpio.h),
2336 then you may alternatively define the two GPIOs that are to be
2337 used as SCL / SDA. Any of the previous I2C_xxx macros will
2338 have GPIO-based defaults assigned to them as appropriate.
2340 You should define these to the GPIO value as given directly to
2341 the generic GPIO functions.
2343 CONFIG_SYS_I2C_INIT_BOARD
2345 When a board is reset during an i2c bus transfer
2346 chips might think that the current transfer is still
2347 in progress. On some boards it is possible to access
2348 the i2c SCLK line directly, either by using the
2349 processor pin as a GPIO or by having a second pin
2350 connected to the bus. If this option is defined a
2351 custom i2c_init_board() routine in boards/xxx/board.c
2352 is run early in the boot sequence.
2354 CONFIG_SYS_I2C_BOARD_LATE_INIT
2356 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2357 defined a custom i2c_board_late_init() routine in
2358 boards/xxx/board.c is run AFTER the operations in i2c_init()
2359 is completed. This callpoint can be used to unreset i2c bus
2360 using CPU i2c controller register accesses for CPUs whose i2c
2361 controller provide such a method. It is called at the end of
2362 i2c_init() to allow i2c_init operations to setup the i2c bus
2363 controller on the CPU (e.g. setting bus speed & slave address).
2365 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2367 This option enables configuration of bi_iic_fast[] flags
2368 in u-boot bd_info structure based on u-boot environment
2369 variable "i2cfast". (see also i2cfast)
2371 CONFIG_I2C_MULTI_BUS
2373 This option allows the use of multiple I2C buses, each of which
2374 must have a controller. At any point in time, only one bus is
2375 active. To switch to a different bus, use the 'i2c dev' command.
2376 Note that bus numbering is zero-based.
2378 CONFIG_SYS_I2C_NOPROBES
2380 This option specifies a list of I2C devices that will be skipped
2381 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2382 is set, specify a list of bus-device pairs. Otherwise, specify
2383 a 1D array of device addresses
2386 #undef CONFIG_I2C_MULTI_BUS
2387 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2389 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2391 #define CONFIG_I2C_MULTI_BUS
2392 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2394 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2396 CONFIG_SYS_SPD_BUS_NUM
2398 If defined, then this indicates the I2C bus number for DDR SPD.
2399 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2401 CONFIG_SYS_RTC_BUS_NUM
2403 If defined, then this indicates the I2C bus number for the RTC.
2404 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2406 CONFIG_SYS_DTT_BUS_NUM
2408 If defined, then this indicates the I2C bus number for the DTT.
2409 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2411 CONFIG_SYS_I2C_DTT_ADDR:
2413 If defined, specifies the I2C address of the DTT device.
2414 If not defined, then U-Boot uses predefined value for
2415 specified DTT device.
2417 CONFIG_SOFT_I2C_READ_REPEATED_START
2419 defining this will force the i2c_read() function in
2420 the soft_i2c driver to perform an I2C repeated start
2421 between writing the address pointer and reading the
2422 data. If this define is omitted the default behaviour
2423 of doing a stop-start sequence will be used. Most I2C
2424 devices can use either method, but some require one or
2427 - SPI Support: CONFIG_SPI
2429 Enables SPI driver (so far only tested with
2430 SPI EEPROM, also an instance works with Crystal A/D and
2431 D/As on the SACSng board)
2435 Enables the driver for SPI controller on SuperH. Currently
2436 only SH7757 is supported.
2440 Enables extended (16-bit) SPI EEPROM addressing.
2441 (symmetrical to CONFIG_I2C_X)
2445 Enables a software (bit-bang) SPI driver rather than
2446 using hardware support. This is a general purpose
2447 driver that only requires three general I/O port pins
2448 (two outputs, one input) to function. If this is
2449 defined, the board configuration must define several
2450 SPI configuration items (port pins to use, etc). For
2451 an example, see include/configs/sacsng.h.
2455 Enables a hardware SPI driver for general-purpose reads
2456 and writes. As with CONFIG_SOFT_SPI, the board configuration
2457 must define a list of chip-select function pointers.
2458 Currently supported on some MPC8xxx processors. For an
2459 example, see include/configs/mpc8349emds.h.
2463 Enables the driver for the SPI controllers on i.MX and MXC
2464 SoCs. Currently i.MX31/35/51 are supported.
2466 - FPGA Support: CONFIG_FPGA
2468 Enables FPGA subsystem.
2470 CONFIG_FPGA_<vendor>
2472 Enables support for specific chip vendors.
2475 CONFIG_FPGA_<family>
2477 Enables support for FPGA family.
2478 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2482 Specify the number of FPGA devices to support.
2484 CONFIG_SYS_FPGA_PROG_FEEDBACK
2486 Enable printing of hash marks during FPGA configuration.
2488 CONFIG_SYS_FPGA_CHECK_BUSY
2490 Enable checks on FPGA configuration interface busy
2491 status by the configuration function. This option
2492 will require a board or device specific function to
2497 If defined, a function that provides delays in the FPGA
2498 configuration driver.
2500 CONFIG_SYS_FPGA_CHECK_CTRLC
2501 Allow Control-C to interrupt FPGA configuration
2503 CONFIG_SYS_FPGA_CHECK_ERROR
2505 Check for configuration errors during FPGA bitfile
2506 loading. For example, abort during Virtex II
2507 configuration if the INIT_B line goes low (which
2508 indicated a CRC error).
2510 CONFIG_SYS_FPGA_WAIT_INIT
2512 Maximum time to wait for the INIT_B line to deassert
2513 after PROB_B has been deasserted during a Virtex II
2514 FPGA configuration sequence. The default time is 500
2517 CONFIG_SYS_FPGA_WAIT_BUSY
2519 Maximum time to wait for BUSY to deassert during
2520 Virtex II FPGA configuration. The default is 5 ms.
2522 CONFIG_SYS_FPGA_WAIT_CONFIG
2524 Time to wait after FPGA configuration. The default is
2527 - Configuration Management:
2530 If defined, this string will be added to the U-Boot
2531 version information (U_BOOT_VERSION)
2533 - Vendor Parameter Protection:
2535 U-Boot considers the values of the environment
2536 variables "serial#" (Board Serial Number) and
2537 "ethaddr" (Ethernet Address) to be parameters that
2538 are set once by the board vendor / manufacturer, and
2539 protects these variables from casual modification by
2540 the user. Once set, these variables are read-only,
2541 and write or delete attempts are rejected. You can
2542 change this behaviour:
2544 If CONFIG_ENV_OVERWRITE is #defined in your config
2545 file, the write protection for vendor parameters is
2546 completely disabled. Anybody can change or delete
2549 Alternatively, if you #define _both_ CONFIG_ETHADDR
2550 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2551 Ethernet address is installed in the environment,
2552 which can be changed exactly ONCE by the user. [The
2553 serial# is unaffected by this, i. e. it remains
2556 The same can be accomplished in a more flexible way
2557 for any variable by configuring the type of access
2558 to allow for those variables in the ".flags" variable
2559 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2564 Define this variable to enable the reservation of
2565 "protected RAM", i. e. RAM which is not overwritten
2566 by U-Boot. Define CONFIG_PRAM to hold the number of
2567 kB you want to reserve for pRAM. You can overwrite
2568 this default value by defining an environment
2569 variable "pram" to the number of kB you want to
2570 reserve. Note that the board info structure will
2571 still show the full amount of RAM. If pRAM is
2572 reserved, a new environment variable "mem" will
2573 automatically be defined to hold the amount of
2574 remaining RAM in a form that can be passed as boot
2575 argument to Linux, for instance like that:
2577 setenv bootargs ... mem=\${mem}
2580 This way you can tell Linux not to use this memory,
2581 either, which results in a memory region that will
2582 not be affected by reboots.
2584 *WARNING* If your board configuration uses automatic
2585 detection of the RAM size, you must make sure that
2586 this memory test is non-destructive. So far, the
2587 following board configurations are known to be
2590 IVMS8, IVML24, SPD8xx, TQM8xxL,
2591 HERMES, IP860, RPXlite, LWMON,
2594 - Access to physical memory region (> 4GB)
2595 Some basic support is provided for operations on memory not
2596 normally accessible to U-Boot - e.g. some architectures
2597 support access to more than 4GB of memory on 32-bit
2598 machines using physical address extension or similar.
2599 Define CONFIG_PHYSMEM to access this basic support, which
2600 currently only supports clearing the memory.
2605 Define this variable to stop the system in case of a
2606 fatal error, so that you have to reset it manually.
2607 This is probably NOT a good idea for an embedded
2608 system where you want the system to reboot
2609 automatically as fast as possible, but it may be
2610 useful during development since you can try to debug
2611 the conditions that lead to the situation.
2613 CONFIG_NET_RETRY_COUNT
2615 This variable defines the number of retries for
2616 network operations like ARP, RARP, TFTP, or BOOTP
2617 before giving up the operation. If not defined, a
2618 default value of 5 is used.
2622 Timeout waiting for an ARP reply in milliseconds.
2626 Timeout in milliseconds used in NFS protocol.
2627 If you encounter "ERROR: Cannot umount" in nfs command,
2628 try longer timeout such as
2629 #define CONFIG_NFS_TIMEOUT 10000UL
2631 - Command Interpreter:
2632 CONFIG_AUTO_COMPLETE
2634 Enable auto completion of commands using TAB.
2636 Note that this feature has NOT been implemented yet
2637 for the "hush" shell.
2640 CONFIG_SYS_HUSH_PARSER
2642 Define this variable to enable the "hush" shell (from
2643 Busybox) as command line interpreter, thus enabling
2644 powerful command line syntax like
2645 if...then...else...fi conditionals or `&&' and '||'
2646 constructs ("shell scripts").
2648 If undefined, you get the old, much simpler behaviour
2649 with a somewhat smaller memory footprint.
2652 CONFIG_SYS_PROMPT_HUSH_PS2
2654 This defines the secondary prompt string, which is
2655 printed when the command interpreter needs more input
2656 to complete a command. Usually "> ".
2660 In the current implementation, the local variables
2661 space and global environment variables space are
2662 separated. Local variables are those you define by
2663 simply typing `name=value'. To access a local
2664 variable later on, you have write `$name' or
2665 `${name}'; to execute the contents of a variable
2666 directly type `$name' at the command prompt.
2668 Global environment variables are those you use
2669 setenv/printenv to work with. To run a command stored
2670 in such a variable, you need to use the run command,
2671 and you must not use the '$' sign to access them.
2673 To store commands and special characters in a
2674 variable, please use double quotation marks
2675 surrounding the whole text of the variable, instead
2676 of the backslashes before semicolons and special
2679 - Commandline Editing and History:
2680 CONFIG_CMDLINE_EDITING
2682 Enable editing and History functions for interactive
2683 commandline input operations
2685 - Default Environment:
2686 CONFIG_EXTRA_ENV_SETTINGS
2688 Define this to contain any number of null terminated
2689 strings (variable = value pairs) that will be part of
2690 the default environment compiled into the boot image.
2692 For example, place something like this in your
2693 board's config file:
2695 #define CONFIG_EXTRA_ENV_SETTINGS \
2699 Warning: This method is based on knowledge about the
2700 internal format how the environment is stored by the
2701 U-Boot code. This is NOT an official, exported
2702 interface! Although it is unlikely that this format
2703 will change soon, there is no guarantee either.
2704 You better know what you are doing here.
2706 Note: overly (ab)use of the default environment is
2707 discouraged. Make sure to check other ways to preset
2708 the environment like the "source" command or the
2711 CONFIG_ENV_VARS_UBOOT_CONFIG
2713 Define this in order to add variables describing the
2714 U-Boot build configuration to the default environment.
2715 These will be named arch, cpu, board, vendor, and soc.
2717 Enabling this option will cause the following to be defined:
2725 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2727 Define this in order to add variables describing certain
2728 run-time determined information about the hardware to the
2729 environment. These will be named board_name, board_rev.
2731 CONFIG_DELAY_ENVIRONMENT
2733 Normally the environment is loaded when the board is
2734 intialised so that it is available to U-Boot. This inhibits
2735 that so that the environment is not available until
2736 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2737 this is instead controlled by the value of
2738 /config/load-environment.
2740 - DataFlash Support:
2741 CONFIG_HAS_DATAFLASH
2743 Defining this option enables DataFlash features and
2744 allows to read/write in Dataflash via the standard
2747 - Serial Flash support
2750 Defining this option enables SPI flash commands
2751 'sf probe/read/write/erase/update'.
2753 Usage requires an initial 'probe' to define the serial
2754 flash parameters, followed by read/write/erase/update
2757 The following defaults may be provided by the platform
2758 to handle the common case when only a single serial
2759 flash is present on the system.
2761 CONFIG_SF_DEFAULT_BUS Bus identifier
2762 CONFIG_SF_DEFAULT_CS Chip-select
2763 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2764 CONFIG_SF_DEFAULT_SPEED in Hz
2768 Define this option to include a destructive SPI flash
2771 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2773 Define this option to use the Bank addr/Extended addr
2774 support on SPI flashes which has size > 16Mbytes.
2776 CONFIG_SF_DUAL_FLASH Dual flash memories
2778 Define this option to use dual flash support where two flash
2779 memories can be connected with a given cs line.
2780 currently Xilinx Zynq qspi support these type of connections.
2782 - SystemACE Support:
2785 Adding this option adds support for Xilinx SystemACE
2786 chips attached via some sort of local bus. The address
2787 of the chip must also be defined in the
2788 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2790 #define CONFIG_SYSTEMACE
2791 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2793 When SystemACE support is added, the "ace" device type
2794 becomes available to the fat commands, i.e. fatls.
2796 - TFTP Fixed UDP Port:
2799 If this is defined, the environment variable tftpsrcp
2800 is used to supply the TFTP UDP source port value.
2801 If tftpsrcp isn't defined, the normal pseudo-random port
2802 number generator is used.
2804 Also, the environment variable tftpdstp is used to supply
2805 the TFTP UDP destination port value. If tftpdstp isn't
2806 defined, the normal port 69 is used.
2808 The purpose for tftpsrcp is to allow a TFTP server to
2809 blindly start the TFTP transfer using the pre-configured
2810 target IP address and UDP port. This has the effect of
2811 "punching through" the (Windows XP) firewall, allowing
2812 the remainder of the TFTP transfer to proceed normally.
2813 A better solution is to properly configure the firewall,
2814 but sometimes that is not allowed.
2819 This enables a generic 'hash' command which can produce
2820 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2824 Enable the hash verify command (hash -v). This adds to code
2827 CONFIG_SHA1 - support SHA1 hashing
2828 CONFIG_SHA256 - support SHA256 hashing
2830 Note: There is also a sha1sum command, which should perhaps
2831 be deprecated in favour of 'hash sha1'.
2833 - Freescale i.MX specific commands:
2834 CONFIG_CMD_HDMIDETECT
2835 This enables 'hdmidet' command which returns true if an
2836 HDMI monitor is detected. This command is i.MX 6 specific.
2839 This enables the 'bmode' (bootmode) command for forcing
2840 a boot from specific media.
2842 This is useful for forcing the ROM's usb downloader to
2843 activate upon a watchdog reset which is nice when iterating
2844 on U-Boot. Using the reset button or running bmode normal
2845 will set it back to normal. This command currently
2846 supports i.MX53 and i.MX6.
2851 This enables the RSA algorithm used for FIT image verification
2852 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2854 The signing part is build into mkimage regardless of this
2858 - Show boot progress:
2859 CONFIG_SHOW_BOOT_PROGRESS
2861 Defining this option allows to add some board-
2862 specific code (calling a user-provided function
2863 "show_boot_progress(int)") that enables you to show
2864 the system's boot progress on some display (for
2865 example, some LED's) on your board. At the moment,
2866 the following checkpoints are implemented:
2868 - Detailed boot stage timing
2870 Define this option to get detailed timing of each stage
2871 of the boot process.
2873 CONFIG_BOOTSTAGE_USER_COUNT
2874 This is the number of available user bootstage records.
2875 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2876 a new ID will be allocated from this stash. If you exceed
2877 the limit, recording will stop.
2879 CONFIG_BOOTSTAGE_REPORT
2880 Define this to print a report before boot, similar to this:
2882 Timer summary in microseconds:
2885 3,575,678 3,575,678 board_init_f start
2886 3,575,695 17 arch_cpu_init A9
2887 3,575,777 82 arch_cpu_init done
2888 3,659,598 83,821 board_init_r start
2889 3,910,375 250,777 main_loop
2890 29,916,167 26,005,792 bootm_start
2891 30,361,327 445,160 start_kernel
2893 CONFIG_CMD_BOOTSTAGE
2894 Add a 'bootstage' command which supports printing a report
2895 and un/stashing of bootstage data.
2897 CONFIG_BOOTSTAGE_FDT
2898 Stash the bootstage information in the FDT. A root 'bootstage'
2899 node is created with each bootstage id as a child. Each child
2900 has a 'name' property and either 'mark' containing the
2901 mark time in microsecond, or 'accum' containing the
2902 accumulated time for that bootstage id in microseconds.
2907 name = "board_init_f";
2916 Code in the Linux kernel can find this in /proc/devicetree.
2918 Legacy uImage format:
2921 1 common/cmd_bootm.c before attempting to boot an image
2922 -1 common/cmd_bootm.c Image header has bad magic number
2923 2 common/cmd_bootm.c Image header has correct magic number
2924 -2 common/cmd_bootm.c Image header has bad checksum
2925 3 common/cmd_bootm.c Image header has correct checksum
2926 -3 common/cmd_bootm.c Image data has bad checksum
2927 4 common/cmd_bootm.c Image data has correct checksum
2928 -4 common/cmd_bootm.c Image is for unsupported architecture
2929 5 common/cmd_bootm.c Architecture check OK
2930 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2931 6 common/cmd_bootm.c Image Type check OK
2932 -6 common/cmd_bootm.c gunzip uncompression error
2933 -7 common/cmd_bootm.c Unimplemented compression type
2934 7 common/cmd_bootm.c Uncompression OK
2935 8 common/cmd_bootm.c No uncompress/copy overwrite error
2936 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2938 9 common/image.c Start initial ramdisk verification
2939 -10 common/image.c Ramdisk header has bad magic number
2940 -11 common/image.c Ramdisk header has bad checksum
2941 10 common/image.c Ramdisk header is OK
2942 -12 common/image.c Ramdisk data has bad checksum
2943 11 common/image.c Ramdisk data has correct checksum
2944 12 common/image.c Ramdisk verification complete, start loading
2945 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2946 13 common/image.c Start multifile image verification
2947 14 common/image.c No initial ramdisk, no multifile, continue.
2949 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2951 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2952 -31 post/post.c POST test failed, detected by post_output_backlog()
2953 -32 post/post.c POST test failed, detected by post_run_single()
2955 34 common/cmd_doc.c before loading a Image from a DOC device
2956 -35 common/cmd_doc.c Bad usage of "doc" command
2957 35 common/cmd_doc.c correct usage of "doc" command
2958 -36 common/cmd_doc.c No boot device
2959 36 common/cmd_doc.c correct boot device
2960 -37 common/cmd_doc.c Unknown Chip ID on boot device
2961 37 common/cmd_doc.c correct chip ID found, device available
2962 -38 common/cmd_doc.c Read Error on boot device
2963 38 common/cmd_doc.c reading Image header from DOC device OK
2964 -39 common/cmd_doc.c Image header has bad magic number
2965 39 common/cmd_doc.c Image header has correct magic number
2966 -40 common/cmd_doc.c Error reading Image from DOC device
2967 40 common/cmd_doc.c Image header has correct magic number
2968 41 common/cmd_ide.c before loading a Image from a IDE device
2969 -42 common/cmd_ide.c Bad usage of "ide" command
2970 42 common/cmd_ide.c correct usage of "ide" command
2971 -43 common/cmd_ide.c No boot device
2972 43 common/cmd_ide.c boot device found
2973 -44 common/cmd_ide.c Device not available
2974 44 common/cmd_ide.c Device available
2975 -45 common/cmd_ide.c wrong partition selected
2976 45 common/cmd_ide.c partition selected
2977 -46 common/cmd_ide.c Unknown partition table
2978 46 common/cmd_ide.c valid partition table found
2979 -47 common/cmd_ide.c Invalid partition type
2980 47 common/cmd_ide.c correct partition type
2981 -48 common/cmd_ide.c Error reading Image Header on boot device
2982 48 common/cmd_ide.c reading Image Header from IDE device OK
2983 -49 common/cmd_ide.c Image header has bad magic number
2984 49 common/cmd_ide.c Image header has correct magic number
2985 -50 common/cmd_ide.c Image header has bad checksum
2986 50 common/cmd_ide.c Image header has correct checksum
2987 -51 common/cmd_ide.c Error reading Image from IDE device
2988 51 common/cmd_ide.c reading Image from IDE device OK
2989 52 common/cmd_nand.c before loading a Image from a NAND device
2990 -53 common/cmd_nand.c Bad usage of "nand" command
2991 53 common/cmd_nand.c correct usage of "nand" command
2992 -54 common/cmd_nand.c No boot device
2993 54 common/cmd_nand.c boot device found
2994 -55 common/cmd_nand.c Unknown Chip ID on boot device
2995 55 common/cmd_nand.c correct chip ID found, device available
2996 -56 common/cmd_nand.c Error reading Image Header on boot device
2997 56 common/cmd_nand.c reading Image Header from NAND device OK
2998 -57 common/cmd_nand.c Image header has bad magic number
2999 57 common/cmd_nand.c Image header has correct magic number
3000 -58 common/cmd_nand.c Error reading Image from NAND device
3001 58 common/cmd_nand.c reading Image from NAND device OK
3003 -60 common/env_common.c Environment has a bad CRC, using default
3005 64 net/eth.c starting with Ethernet configuration.
3006 -64 net/eth.c no Ethernet found.
3007 65 net/eth.c Ethernet found.
3009 -80 common/cmd_net.c usage wrong
3010 80 common/cmd_net.c before calling NetLoop()
3011 -81 common/cmd_net.c some error in NetLoop() occurred
3012 81 common/cmd_net.c NetLoop() back without error
3013 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3014 82 common/cmd_net.c trying automatic boot
3015 83 common/cmd_net.c running "source" command
3016 -83 common/cmd_net.c some error in automatic boot or "source" command
3017 84 common/cmd_net.c end without errors
3022 100 common/cmd_bootm.c Kernel FIT Image has correct format
3023 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3024 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3025 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3026 102 common/cmd_bootm.c Kernel unit name specified
3027 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3028 103 common/cmd_bootm.c Found configuration node
3029 104 common/cmd_bootm.c Got kernel subimage node offset
3030 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3031 105 common/cmd_bootm.c Kernel subimage hash verification OK
3032 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3033 106 common/cmd_bootm.c Architecture check OK
3034 -106 common/cmd_bootm.c Kernel subimage has wrong type
3035 107 common/cmd_bootm.c Kernel subimage type OK
3036 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3037 108 common/cmd_bootm.c Got kernel subimage data/size
3038 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3039 -109 common/cmd_bootm.c Can't get kernel subimage type
3040 -110 common/cmd_bootm.c Can't get kernel subimage comp
3041 -111 common/cmd_bootm.c Can't get kernel subimage os
3042 -112 common/cmd_bootm.c Can't get kernel subimage load address
3043 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3045 120 common/image.c Start initial ramdisk verification
3046 -120 common/image.c Ramdisk FIT image has incorrect format
3047 121 common/image.c Ramdisk FIT image has correct format
3048 122 common/image.c No ramdisk subimage unit name, using configuration
3049 -122 common/image.c Can't get configuration for ramdisk subimage
3050 123 common/image.c Ramdisk unit name specified
3051 -124 common/image.c Can't get ramdisk subimage node offset
3052 125 common/image.c Got ramdisk subimage node offset
3053 -125 common/image.c Ramdisk subimage hash verification failed
3054 126 common/image.c Ramdisk subimage hash verification OK
3055 -126 common/image.c Ramdisk subimage for unsupported architecture
3056 127 common/image.c Architecture check OK
3057 -127 common/image.c Can't get ramdisk subimage data/size
3058 128 common/image.c Got ramdisk subimage data/size
3059 129 common/image.c Can't get ramdisk load address
3060 -129 common/image.c Got ramdisk load address
3062 -130 common/cmd_doc.c Incorrect FIT image format
3063 131 common/cmd_doc.c FIT image format OK
3065 -140 common/cmd_ide.c Incorrect FIT image format
3066 141 common/cmd_ide.c FIT image format OK
3068 -150 common/cmd_nand.c Incorrect FIT image format
3069 151 common/cmd_nand.c FIT image format OK
3071 - FIT image support:
3073 Enable support for the FIT uImage format.
3075 CONFIG_FIT_BEST_MATCH
3076 When no configuration is explicitly selected, default to the
3077 one whose fdt's compatibility field best matches that of
3078 U-Boot itself. A match is considered "best" if it matches the
3079 most specific compatibility entry of U-Boot's fdt's root node.
3080 The order of entries in the configuration's fdt is ignored.
3082 CONFIG_FIT_SIGNATURE
3083 This option enables signature verification of FIT uImages,
3084 using a hash signed and verified using RSA. See
3085 doc/uImage.FIT/signature.txt for more details.
3087 - Standalone program support:
3088 CONFIG_STANDALONE_LOAD_ADDR
3090 This option defines a board specific value for the
3091 address where standalone program gets loaded, thus
3092 overwriting the architecture dependent default
3095 - Frame Buffer Address:
3098 Define CONFIG_FB_ADDR if you want to use specific
3099 address for frame buffer. This is typically the case
3100 when using a graphics controller has separate video
3101 memory. U-Boot will then place the frame buffer at
3102 the given address instead of dynamically reserving it
3103 in system RAM by calling lcd_setmem(), which grabs
3104 the memory for the frame buffer depending on the
3105 configured panel size.
3107 Please see board_init_f function.
3109 - Automatic software updates via TFTP server
3111 CONFIG_UPDATE_TFTP_CNT_MAX
3112 CONFIG_UPDATE_TFTP_MSEC_MAX
3114 These options enable and control the auto-update feature;
3115 for a more detailed description refer to doc/README.update.
3117 - MTD Support (mtdparts command, UBI support)
3120 Adds the MTD device infrastructure from the Linux kernel.
3121 Needed for mtdparts command support.
3123 CONFIG_MTD_PARTITIONS
3125 Adds the MTD partitioning infrastructure from the Linux
3126 kernel. Needed for UBI support.
3131 Adds commands for interacting with MTD partitions formatted
3132 with the UBI flash translation layer
3134 Requires also defining CONFIG_RBTREE
3136 CONFIG_UBI_SILENCE_MSG
3138 Make the verbose messages from UBI stop printing. This leaves
3139 warnings and errors enabled.
3144 Adds commands for interacting with UBI volumes formatted as
3145 UBIFS. UBIFS is read-only in u-boot.
3147 Requires UBI support as well as CONFIG_LZO
3149 CONFIG_UBIFS_SILENCE_MSG
3151 Make the verbose messages from UBIFS stop printing. This leaves
3152 warnings and errors enabled.
3156 Enable building of SPL globally.
3159 LDSCRIPT for linking the SPL binary.
3161 CONFIG_SPL_MAX_FOOTPRINT
3162 Maximum size in memory allocated to the SPL, BSS included.
3163 When defined, the linker checks that the actual memory
3164 used by SPL from _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 Maximum size of the SPL image (text, data, rodata, and
3170 linker lists sections), BSS excluded.
3171 When defined, the linker checks that the actual size does
3174 CONFIG_SPL_TEXT_BASE
3175 TEXT_BASE for linking the SPL binary.
3177 CONFIG_SPL_RELOC_TEXT_BASE
3178 Address to relocate to. If unspecified, this is equal to
3179 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3181 CONFIG_SPL_BSS_START_ADDR
3182 Link address for the BSS within the SPL binary.
3184 CONFIG_SPL_BSS_MAX_SIZE
3185 Maximum size in memory allocated to the SPL BSS.
3186 When defined, the linker checks that the actual memory used
3187 by SPL from __bss_start to __bss_end does not exceed it.
3188 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3189 must not be both defined at the same time.
3192 Adress of the start of the stack SPL will use
3194 CONFIG_SPL_RELOC_STACK
3195 Adress of the start of the stack SPL will use after
3196 relocation. If unspecified, this is equal to
3199 CONFIG_SYS_SPL_MALLOC_START
3200 Starting address of the malloc pool used in SPL.
3202 CONFIG_SYS_SPL_MALLOC_SIZE
3203 The size of the malloc pool used in SPL.
3205 CONFIG_SPL_FRAMEWORK
3206 Enable the SPL framework under common/. This framework
3207 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3208 NAND loading of the Linux Kernel.
3210 CONFIG_SPL_DISPLAY_PRINT
3211 For ARM, enable an optional function to print more information
3212 about the running system.
3214 CONFIG_SPL_INIT_MINIMAL
3215 Arch init code should be built for a very small image
3217 CONFIG_SPL_LIBCOMMON_SUPPORT
3218 Support for common/libcommon.o in SPL binary
3220 CONFIG_SPL_LIBDISK_SUPPORT
3221 Support for disk/libdisk.o in SPL binary
3223 CONFIG_SPL_I2C_SUPPORT
3224 Support for drivers/i2c/libi2c.o in SPL binary
3226 CONFIG_SPL_GPIO_SUPPORT
3227 Support for drivers/gpio/libgpio.o in SPL binary
3229 CONFIG_SPL_MMC_SUPPORT
3230 Support for drivers/mmc/libmmc.o in SPL binary
3232 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3233 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3234 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3235 Address, size and partition on the MMC to load U-Boot from
3236 when the MMC is being used in raw mode.
3238 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3239 Sector to load kernel uImage from when MMC is being
3240 used in raw mode (for Falcon mode)
3242 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3243 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3244 Sector and number of sectors to load kernel argument
3245 parameters from when MMC is being used in raw mode
3248 CONFIG_SPL_FAT_SUPPORT
3249 Support for fs/fat/libfat.o in SPL binary
3251 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3252 Filename to read to load U-Boot when reading from FAT
3254 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3255 Filename to read to load kernel uImage when reading
3256 from FAT (for Falcon mode)
3258 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3259 Filename to read to load kernel argument parameters
3260 when reading from FAT (for Falcon mode)
3262 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3263 Set this for NAND SPL on PPC mpc83xx targets, so that
3264 start.S waits for the rest of the SPL to load before
3265 continuing (the hardware starts execution after just
3266 loading the first page rather than the full 4K).
3268 CONFIG_SPL_NAND_BASE
3269 Include nand_base.c in the SPL. Requires
3270 CONFIG_SPL_NAND_DRIVERS.
3272 CONFIG_SPL_NAND_DRIVERS
3273 SPL uses normal NAND drivers, not minimal drivers.
3276 Include standard software ECC in the SPL
3278 CONFIG_SPL_NAND_SIMPLE
3279 Support for NAND boot using simple NAND drivers that
3280 expose the cmd_ctrl() interface.
3282 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3283 Set for the SPL on PPC mpc8xxx targets, support for
3284 drivers/ddr/fsl/libddr.o in SPL binary.
3286 CONFIG_SPL_COMMON_INIT_DDR
3287 Set for common ddr init with serial presence detect in
3290 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3291 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3292 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3293 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3294 CONFIG_SYS_NAND_ECCBYTES
3295 Defines the size and behavior of the NAND that SPL uses
3298 CONFIG_SPL_NAND_BOOT
3299 Add support NAND boot
3301 CONFIG_SYS_NAND_U_BOOT_OFFS
3302 Location in NAND to read U-Boot from
3304 CONFIG_SYS_NAND_U_BOOT_DST
3305 Location in memory to load U-Boot to
3307 CONFIG_SYS_NAND_U_BOOT_SIZE
3308 Size of image to load
3310 CONFIG_SYS_NAND_U_BOOT_START
3311 Entry point in loaded image to jump to
3313 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3314 Define this if you need to first read the OOB and then the
3315 data. This is used for example on davinci plattforms.
3317 CONFIG_SPL_OMAP3_ID_NAND
3318 Support for an OMAP3-specific set of functions to return the
3319 ID and MFR of the first attached NAND chip, if present.
3321 CONFIG_SPL_SERIAL_SUPPORT
3322 Support for drivers/serial/libserial.o in SPL binary
3324 CONFIG_SPL_SPI_FLASH_SUPPORT
3325 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3327 CONFIG_SPL_SPI_SUPPORT
3328 Support for drivers/spi/libspi.o in SPL binary
3330 CONFIG_SPL_RAM_DEVICE
3331 Support for running image already present in ram, in SPL binary
3333 CONFIG_SPL_LIBGENERIC_SUPPORT
3334 Support for lib/libgeneric.o in SPL binary
3336 CONFIG_SPL_ENV_SUPPORT
3337 Support for the environment operating in SPL binary
3339 CONFIG_SPL_NET_SUPPORT
3340 Support for the net/libnet.o in SPL binary.
3341 It conflicts with SPL env from storage medium specified by
3342 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3345 Image offset to which the SPL should be padded before appending
3346 the SPL payload. By default, this is defined as
3347 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3348 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3349 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3352 Final target image containing SPL and payload. Some SPLs
3353 use an arch-specific makefile fragment instead, for
3354 example if more than one image needs to be produced.
3356 CONFIG_FIT_SPL_PRINT
3357 Printing information about a FIT image adds quite a bit of
3358 code to SPL. So this is normally disabled in SPL. Use this
3359 option to re-enable it. This will affect the output of the
3360 bootm command when booting a FIT image.
3364 Enable building of TPL globally.
3367 Image offset to which the TPL should be padded before appending
3368 the TPL payload. By default, this is defined as
3369 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3370 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3371 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3376 [so far only for SMDK2400 boards]
3378 - Modem support enable:
3379 CONFIG_MODEM_SUPPORT
3381 - RTS/CTS Flow control enable:
3384 - Modem debug support:
3385 CONFIG_MODEM_SUPPORT_DEBUG
3387 Enables debugging stuff (char screen[1024], dbg())
3388 for modem support. Useful only with BDI2000.
3390 - Interrupt support (PPC):
3392 There are common interrupt_init() and timer_interrupt()
3393 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3394 for CPU specific initialization. interrupt_init_cpu()
3395 should set decrementer_count to appropriate value. If
3396 CPU resets decrementer automatically after interrupt
3397 (ppc4xx) it should set decrementer_count to zero.
3398 timer_interrupt() calls timer_interrupt_cpu() for CPU
3399 specific handling. If board has watchdog / status_led
3400 / other_activity_monitor it works automatically from
3401 general timer_interrupt().
3405 In the target system modem support is enabled when a
3406 specific key (key combination) is pressed during
3407 power-on. Otherwise U-Boot will boot normally
3408 (autoboot). The key_pressed() function is called from
3409 board_init(). Currently key_pressed() is a dummy
3410 function, returning 1 and thus enabling modem
3413 If there are no modem init strings in the
3414 environment, U-Boot proceed to autoboot; the
3415 previous output (banner, info printfs) will be
3418 See also: doc/README.Modem
3420 Board initialization settings:
3421 ------------------------------
3423 During Initialization u-boot calls a number of board specific functions
3424 to allow the preparation of board specific prerequisites, e.g. pin setup
3425 before drivers are initialized. To enable these callbacks the
3426 following configuration macros have to be defined. Currently this is
3427 architecture specific, so please check arch/your_architecture/lib/board.c
3428 typically in board_init_f() and board_init_r().
3430 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3431 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3432 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3433 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3435 Configuration Settings:
3436 -----------------------
3438 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3439 undefine this when you're short of memory.
3441 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3442 width of the commands listed in the 'help' command output.
3444 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3445 prompt for user input.
3447 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3449 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3451 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3453 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3454 the application (usually a Linux kernel) when it is
3457 - CONFIG_SYS_BAUDRATE_TABLE:
3458 List of legal baudrate settings for this board.
3460 - CONFIG_SYS_CONSOLE_INFO_QUIET
3461 Suppress display of console information at boot.
3463 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3464 If the board specific function
3465 extern int overwrite_console (void);
3466 returns 1, the stdin, stderr and stdout are switched to the
3467 serial port, else the settings in the environment are used.
3469 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3470 Enable the call to overwrite_console().
3472 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3473 Enable overwrite of previous console environment settings.
3475 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3476 Begin and End addresses of the area used by the
3479 - CONFIG_SYS_ALT_MEMTEST:
3480 Enable an alternate, more extensive memory test.
3482 - CONFIG_SYS_MEMTEST_SCRATCH:
3483 Scratch address used by the alternate memory test
3484 You only need to set this if address zero isn't writeable
3486 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3487 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3488 this specified memory area will get subtracted from the top
3489 (end) of RAM and won't get "touched" at all by U-Boot. By
3490 fixing up gd->ram_size the Linux kernel should gets passed
3491 the now "corrected" memory size and won't touch it either.
3492 This should work for arch/ppc and arch/powerpc. Only Linux
3493 board ports in arch/powerpc with bootwrapper support that
3494 recalculate the memory size from the SDRAM controller setup
3495 will have to get fixed in Linux additionally.
3497 This option can be used as a workaround for the 440EPx/GRx
3498 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3501 WARNING: Please make sure that this value is a multiple of
3502 the Linux page size (normally 4k). If this is not the case,
3503 then the end address of the Linux memory will be located at a
3504 non page size aligned address and this could cause major
3507 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3508 Enable temporary baudrate change while serial download
3510 - CONFIG_SYS_SDRAM_BASE:
3511 Physical start address of SDRAM. _Must_ be 0 here.
3513 - CONFIG_SYS_MBIO_BASE:
3514 Physical start address of Motherboard I/O (if using a
3517 - CONFIG_SYS_FLASH_BASE:
3518 Physical start address of Flash memory.
3520 - CONFIG_SYS_MONITOR_BASE:
3521 Physical start address of boot monitor code (set by
3522 make config files to be same as the text base address
3523 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3524 CONFIG_SYS_FLASH_BASE when booting from flash.
3526 - CONFIG_SYS_MONITOR_LEN:
3527 Size of memory reserved for monitor code, used to
3528 determine _at_compile_time_ (!) if the environment is
3529 embedded within the U-Boot image, or in a separate
3532 - CONFIG_SYS_MALLOC_LEN:
3533 Size of DRAM reserved for malloc() use.
3535 - CONFIG_SYS_BOOTM_LEN:
3536 Normally compressed uImages are limited to an
3537 uncompressed size of 8 MBytes. If this is not enough,
3538 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3539 to adjust this setting to your needs.
3541 - CONFIG_SYS_BOOTMAPSZ:
3542 Maximum size of memory mapped by the startup code of
3543 the Linux kernel; all data that must be processed by
3544 the Linux kernel (bd_info, boot arguments, FDT blob if
3545 used) must be put below this limit, unless "bootm_low"
3546 environment variable is defined and non-zero. In such case
3547 all data for the Linux kernel must be between "bootm_low"
3548 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3549 variable "bootm_mapsize" will override the value of
3550 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3551 then the value in "bootm_size" will be used instead.
3553 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3554 Enable initrd_high functionality. If defined then the
3555 initrd_high feature is enabled and the bootm ramdisk subcommand
3558 - CONFIG_SYS_BOOT_GET_CMDLINE:
3559 Enables allocating and saving kernel cmdline in space between
3560 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3562 - CONFIG_SYS_BOOT_GET_KBD:
3563 Enables allocating and saving a kernel copy of the bd_info in
3564 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3566 - CONFIG_SYS_MAX_FLASH_BANKS:
3567 Max number of Flash memory banks
3569 - CONFIG_SYS_MAX_FLASH_SECT:
3570 Max number of sectors on a Flash chip
3572 - CONFIG_SYS_FLASH_ERASE_TOUT:
3573 Timeout for Flash erase operations (in ms)
3575 - CONFIG_SYS_FLASH_WRITE_TOUT:
3576 Timeout for Flash write operations (in ms)
3578 - CONFIG_SYS_FLASH_LOCK_TOUT
3579 Timeout for Flash set sector lock bit operation (in ms)
3581 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3582 Timeout for Flash clear lock bits operation (in ms)
3584 - CONFIG_SYS_FLASH_PROTECTION
3585 If defined, hardware flash sectors protection is used
3586 instead of U-Boot software protection.
3588 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3590 Enable TFTP transfers directly to flash memory;
3591 without this option such a download has to be
3592 performed in two steps: (1) download to RAM, and (2)
3593 copy from RAM to flash.
3595 The two-step approach is usually more reliable, since
3596 you can check if the download worked before you erase
3597 the flash, but in some situations (when system RAM is
3598 too limited to allow for a temporary copy of the
3599 downloaded image) this option may be very useful.
3601 - CONFIG_SYS_FLASH_CFI:
3602 Define if the flash driver uses extra elements in the
3603 common flash structure for storing flash geometry.
3605 - CONFIG_FLASH_CFI_DRIVER
3606 This option also enables the building of the cfi_flash driver
3607 in the drivers directory
3609 - CONFIG_FLASH_CFI_MTD
3610 This option enables the building of the cfi_mtd driver
3611 in the drivers directory. The driver exports CFI flash
3614 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3615 Use buffered writes to flash.
3617 - CONFIG_FLASH_SPANSION_S29WS_N
3618 s29ws-n MirrorBit flash has non-standard addresses for buffered
3621 - CONFIG_SYS_FLASH_QUIET_TEST
3622 If this option is defined, the common CFI flash doesn't
3623 print it's warning upon not recognized FLASH banks. This
3624 is useful, if some of the configured banks are only
3625 optionally available.
3627 - CONFIG_FLASH_SHOW_PROGRESS
3628 If defined (must be an integer), print out countdown
3629 digits and dots. Recommended value: 45 (9..1) for 80
3630 column displays, 15 (3..1) for 40 column displays.
3632 - CONFIG_FLASH_VERIFY
3633 If defined, the content of the flash (destination) is compared
3634 against the source after the write operation. An error message
3635 will be printed when the contents are not identical.
3636 Please note that this option is useless in nearly all cases,
3637 since such flash programming errors usually are detected earlier
3638 while unprotecting/erasing/programming. Please only enable
3639 this option if you really know what you are doing.
3641 - CONFIG_SYS_RX_ETH_BUFFER:
3642 Defines the number of Ethernet receive buffers. On some
3643 Ethernet controllers it is recommended to set this value
3644 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3645 buffers can be full shortly after enabling the interface
3646 on high Ethernet traffic.
3647 Defaults to 4 if not defined.
3649 - CONFIG_ENV_MAX_ENTRIES
3651 Maximum number of entries in the hash table that is used
3652 internally to store the environment settings. The default
3653 setting is supposed to be generous and should work in most
3654 cases. This setting can be used to tune behaviour; see
3655 lib/hashtable.c for details.
3657 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3658 - CONFIG_ENV_FLAGS_LIST_STATIC
3659 Enable validation of the values given to environment variables when
3660 calling env set. Variables can be restricted to only decimal,
3661 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3662 the variables can also be restricted to IP address or MAC address.
3664 The format of the list is:
3665 type_attribute = [s|d|x|b|i|m]
3666 access_atribute = [a|r|o|c]
3667 attributes = type_attribute[access_atribute]
3668 entry = variable_name[:attributes]
3671 The type attributes are:
3672 s - String (default)
3675 b - Boolean ([1yYtT|0nNfF])
3679 The access attributes are:
3685 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3686 Define this to a list (string) to define the ".flags"
3687 envirnoment variable in the default or embedded environment.
3689 - CONFIG_ENV_FLAGS_LIST_STATIC
3690 Define this to a list (string) to define validation that
3691 should be done if an entry is not found in the ".flags"
3692 environment variable. To override a setting in the static
3693 list, simply add an entry for the same variable name to the
3696 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3697 If defined, don't allow the -f switch to env set override variable
3700 - CONFIG_SYS_GENERIC_BOARD
3701 This selects the architecture-generic board system instead of the
3702 architecture-specific board files. It is intended to move boards
3703 to this new framework over time. Defining this will disable the
3704 arch/foo/lib/board.c file and use common/board_f.c and
3705 common/board_r.c instead. To use this option your architecture
3706 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3707 its config.mk file). If you find problems enabling this option on
3708 your board please report the problem and send patches!
3710 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3711 This is set by OMAP boards for the max time that reset should
3712 be asserted. See doc/README.omap-reset-time for details on how
3713 the value can be calulated on a given board.
3715 The following definitions that deal with the placement and management
3716 of environment data (variable area); in general, we support the
3717 following configurations:
3719 - CONFIG_BUILD_ENVCRC:
3721 Builds up envcrc with the target environment so that external utils
3722 may easily extract it and embed it in final U-Boot images.
3724 - CONFIG_ENV_IS_IN_FLASH:
3726 Define this if the environment is in flash memory.
3728 a) The environment occupies one whole flash sector, which is
3729 "embedded" in the text segment with the U-Boot code. This
3730 happens usually with "bottom boot sector" or "top boot
3731 sector" type flash chips, which have several smaller
3732 sectors at the start or the end. For instance, such a
3733 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3734 such a case you would place the environment in one of the
3735 4 kB sectors - with U-Boot code before and after it. With
3736 "top boot sector" type flash chips, you would put the
3737 environment in one of the last sectors, leaving a gap
3738 between U-Boot and the environment.
3740 - CONFIG_ENV_OFFSET:
3742 Offset of environment data (variable area) to the
3743 beginning of flash memory; for instance, with bottom boot
3744 type flash chips the second sector can be used: the offset
3745 for this sector is given here.
3747 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3751 This is just another way to specify the start address of
3752 the flash sector containing the environment (instead of
3755 - CONFIG_ENV_SECT_SIZE:
3757 Size of the sector containing the environment.
3760 b) Sometimes flash chips have few, equal sized, BIG sectors.
3761 In such a case you don't want to spend a whole sector for
3766 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3767 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3768 of this flash sector for the environment. This saves
3769 memory for the RAM copy of the environment.
3771 It may also save flash memory if you decide to use this
3772 when your environment is "embedded" within U-Boot code,
3773 since then the remainder of the flash sector could be used
3774 for U-Boot code. It should be pointed out that this is
3775 STRONGLY DISCOURAGED from a robustness point of view:
3776 updating the environment in flash makes it always
3777 necessary to erase the WHOLE sector. If something goes
3778 wrong before the contents has been restored from a copy in
3779 RAM, your target system will be dead.
3781 - CONFIG_ENV_ADDR_REDUND
3782 CONFIG_ENV_SIZE_REDUND
3784 These settings describe a second storage area used to hold
3785 a redundant copy of the environment data, so that there is
3786 a valid backup copy in case there is a power failure during
3787 a "saveenv" operation.
3789 BE CAREFUL! Any changes to the flash layout, and some changes to the
3790 source code will make it necessary to adapt <board>/u-boot.lds*
3794 - CONFIG_ENV_IS_IN_NVRAM:
3796 Define this if you have some non-volatile memory device
3797 (NVRAM, battery buffered SRAM) which you want to use for the
3803 These two #defines are used to determine the memory area you
3804 want to use for environment. It is assumed that this memory
3805 can just be read and written to, without any special
3808 BE CAREFUL! The first access to the environment happens quite early
3809 in U-Boot initalization (when we try to get the setting of for the
3810 console baudrate). You *MUST* have mapped your NVRAM area then, or
3813 Please note that even with NVRAM we still use a copy of the
3814 environment in RAM: we could work on NVRAM directly, but we want to
3815 keep settings there always unmodified except somebody uses "saveenv"
3816 to save the current settings.
3819 - CONFIG_ENV_IS_IN_EEPROM:
3821 Use this if you have an EEPROM or similar serial access
3822 device and a driver for it.
3824 - CONFIG_ENV_OFFSET:
3827 These two #defines specify the offset and size of the
3828 environment area within the total memory of your EEPROM.
3830 - CONFIG_SYS_I2C_EEPROM_ADDR:
3831 If defined, specified the chip address of the EEPROM device.
3832 The default address is zero.
3834 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3835 If defined, the number of bits used to address bytes in a
3836 single page in the EEPROM device. A 64 byte page, for example
3837 would require six bits.
3839 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3840 If defined, the number of milliseconds to delay between
3841 page writes. The default is zero milliseconds.
3843 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3844 The length in bytes of the EEPROM memory array address. Note
3845 that this is NOT the chip address length!
3847 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3848 EEPROM chips that implement "address overflow" are ones
3849 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3850 address and the extra bits end up in the "chip address" bit
3851 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3854 Note that we consider the length of the address field to
3855 still be one byte because the extra address bits are hidden
3856 in the chip address.
3858 - CONFIG_SYS_EEPROM_SIZE:
3859 The size in bytes of the EEPROM device.
3861 - CONFIG_ENV_EEPROM_IS_ON_I2C
3862 define this, if you have I2C and SPI activated, and your
3863 EEPROM, which holds the environment, is on the I2C bus.
3865 - CONFIG_I2C_ENV_EEPROM_BUS
3866 if you have an Environment on an EEPROM reached over
3867 I2C muxes, you can define here, how to reach this
3868 EEPROM. For example:
3870 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3872 EEPROM which holds the environment, is reached over
3873 a pca9547 i2c mux with address 0x70, channel 3.
3875 - CONFIG_ENV_IS_IN_DATAFLASH:
3877 Define this if you have a DataFlash memory device which you
3878 want to use for the environment.
3880 - CONFIG_ENV_OFFSET:
3884 These three #defines specify the offset and size of the
3885 environment area within the total memory of your DataFlash placed
3886 at the specified address.
3888 - CONFIG_ENV_IS_IN_REMOTE:
3890 Define this if you have a remote memory space which you
3891 want to use for the local device's environment.
3896 These two #defines specify the address and size of the
3897 environment area within the remote memory space. The
3898 local device can get the environment from remote memory
3899 space by SRIO or PCIE links.
3901 BE CAREFUL! For some special cases, the local device can not use
3902 "saveenv" command. For example, the local device will get the
3903 environment stored in a remote NOR flash by SRIO or PCIE link,
3904 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3906 - CONFIG_ENV_IS_IN_NAND:
3908 Define this if you have a NAND device which you want to use
3909 for the environment.
3911 - CONFIG_ENV_OFFSET:
3914 These two #defines specify the offset and size of the environment
3915 area within the first NAND device. CONFIG_ENV_OFFSET must be
3916 aligned to an erase block boundary.
3918 - CONFIG_ENV_OFFSET_REDUND (optional):
3920 This setting describes a second storage area of CONFIG_ENV_SIZE
3921 size used to hold a redundant copy of the environment data, so
3922 that there is a valid backup copy in case there is a power failure
3923 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3924 aligned to an erase block boundary.
3926 - CONFIG_ENV_RANGE (optional):
3928 Specifies the length of the region in which the environment
3929 can be written. This should be a multiple of the NAND device's
3930 block size. Specifying a range with more erase blocks than
3931 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3932 the range to be avoided.
3934 - CONFIG_ENV_OFFSET_OOB (optional):
3936 Enables support for dynamically retrieving the offset of the
3937 environment from block zero's out-of-band data. The
3938 "nand env.oob" command can be used to record this offset.
3939 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3940 using CONFIG_ENV_OFFSET_OOB.
3942 - CONFIG_NAND_ENV_DST
3944 Defines address in RAM to which the nand_spl code should copy the
3945 environment. If redundant environment is used, it will be copied to
3946 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3948 - CONFIG_ENV_IS_IN_UBI:
3950 Define this if you have an UBI volume that you want to use for the
3951 environment. This has the benefit of wear-leveling the environment
3952 accesses, which is important on NAND.
3954 - CONFIG_ENV_UBI_PART:
3956 Define this to a string that is the mtd partition containing the UBI.
3958 - CONFIG_ENV_UBI_VOLUME:
3960 Define this to the name of the volume that you want to store the
3963 - CONFIG_ENV_UBI_VOLUME_REDUND:
3965 Define this to the name of another volume to store a second copy of
3966 the environment in. This will enable redundant environments in UBI.
3967 It is assumed that both volumes are in the same MTD partition.
3969 - CONFIG_UBI_SILENCE_MSG
3970 - CONFIG_UBIFS_SILENCE_MSG
3972 You will probably want to define these to avoid a really noisy system
3973 when storing the env in UBI.
3975 - CONFIG_ENV_IS_IN_MMC:
3977 Define this if you have an MMC device which you want to use for the
3980 - CONFIG_SYS_MMC_ENV_DEV:
3982 Specifies which MMC device the environment is stored in.
3984 - CONFIG_SYS_MMC_ENV_PART (optional):
3986 Specifies which MMC partition the environment is stored in. If not
3987 set, defaults to partition 0, the user area. Common values might be
3988 1 (first MMC boot partition), 2 (second MMC boot partition).
3990 - CONFIG_ENV_OFFSET:
3993 These two #defines specify the offset and size of the environment
3994 area within the specified MMC device.
3996 If offset is positive (the usual case), it is treated as relative to
3997 the start of the MMC partition. If offset is negative, it is treated
3998 as relative to the end of the MMC partition. This can be useful if
3999 your board may be fitted with different MMC devices, which have
4000 different sizes for the MMC partitions, and you always want the
4001 environment placed at the very end of the partition, to leave the
4002 maximum possible space before it, to store other data.
4004 These two values are in units of bytes, but must be aligned to an
4005 MMC sector boundary.
4007 - CONFIG_ENV_OFFSET_REDUND (optional):
4009 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4010 hold a redundant copy of the environment data. This provides a
4011 valid backup copy in case the other copy is corrupted, e.g. due
4012 to a power failure during a "saveenv" operation.
4014 This value may also be positive or negative; this is handled in the
4015 same way as CONFIG_ENV_OFFSET.
4017 This value is also in units of bytes, but must also be aligned to
4018 an MMC sector boundary.
4020 - CONFIG_ENV_SIZE_REDUND (optional):
4022 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4023 set. If this value is set, it must be set to the same value as
4026 - CONFIG_SYS_SPI_INIT_OFFSET
4028 Defines offset to the initial SPI buffer area in DPRAM. The
4029 area is used at an early stage (ROM part) if the environment
4030 is configured to reside in the SPI EEPROM: We need a 520 byte
4031 scratch DPRAM area. It is used between the two initialization
4032 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4033 to be a good choice since it makes it far enough from the
4034 start of the data area as well as from the stack pointer.
4036 Please note that the environment is read-only until the monitor
4037 has been relocated to RAM and a RAM copy of the environment has been
4038 created; also, when using EEPROM you will have to use getenv_f()
4039 until then to read environment variables.
4041 The environment is protected by a CRC32 checksum. Before the monitor
4042 is relocated into RAM, as a result of a bad CRC you will be working
4043 with the compiled-in default environment - *silently*!!! [This is
4044 necessary, because the first environment variable we need is the
4045 "baudrate" setting for the console - if we have a bad CRC, we don't
4046 have any device yet where we could complain.]
4048 Note: once the monitor has been relocated, then it will complain if
4049 the default environment is used; a new CRC is computed as soon as you
4050 use the "saveenv" command to store a valid environment.
4052 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4053 Echo the inverted Ethernet link state to the fault LED.
4055 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4056 also needs to be defined.
4058 - CONFIG_SYS_FAULT_MII_ADDR:
4059 MII address of the PHY to check for the Ethernet link state.
4061 - CONFIG_NS16550_MIN_FUNCTIONS:
4062 Define this if you desire to only have use of the NS16550_init
4063 and NS16550_putc functions for the serial driver located at
4064 drivers/serial/ns16550.c. This option is useful for saving
4065 space for already greatly restricted images, including but not
4066 limited to NAND_SPL configurations.
4068 - CONFIG_DISPLAY_BOARDINFO
4069 Display information about the board that U-Boot is running on
4070 when U-Boot starts up. The board function checkboard() is called
4073 - CONFIG_DISPLAY_BOARDINFO_LATE
4074 Similar to the previous option, but display this information
4075 later, once stdio is running and output goes to the LCD, if
4078 Low Level (hardware related) configuration options:
4079 ---------------------------------------------------
4081 - CONFIG_SYS_CACHELINE_SIZE:
4082 Cache Line Size of the CPU.
4084 - CONFIG_SYS_DEFAULT_IMMR:
4085 Default address of the IMMR after system reset.
4087 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4088 and RPXsuper) to be able to adjust the position of
4089 the IMMR register after a reset.
4091 - CONFIG_SYS_CCSRBAR_DEFAULT:
4092 Default (power-on reset) physical address of CCSR on Freescale
4095 - CONFIG_SYS_CCSRBAR:
4096 Virtual address of CCSR. On a 32-bit build, this is typically
4097 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4099 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4100 for cross-platform code that uses that macro instead.
4102 - CONFIG_SYS_CCSRBAR_PHYS:
4103 Physical address of CCSR. CCSR can be relocated to a new
4104 physical address, if desired. In this case, this macro should
4105 be set to that address. Otherwise, it should be set to the
4106 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4107 is typically relocated on 36-bit builds. It is recommended
4108 that this macro be defined via the _HIGH and _LOW macros:
4110 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4111 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4113 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4114 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4115 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4116 used in assembly code, so it must not contain typecasts or
4117 integer size suffixes (e.g. "ULL").
4119 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4120 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4121 used in assembly code, so it must not contain typecasts or
4122 integer size suffixes (e.g. "ULL").
4124 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4125 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4126 forced to a value that ensures that CCSR is not relocated.
4128 - Floppy Disk Support:
4129 CONFIG_SYS_FDC_DRIVE_NUMBER
4131 the default drive number (default value 0)
4133 CONFIG_SYS_ISA_IO_STRIDE
4135 defines the spacing between FDC chipset registers
4138 CONFIG_SYS_ISA_IO_OFFSET
4140 defines the offset of register from address. It
4141 depends on which part of the data bus is connected to
4142 the FDC chipset. (default value 0)
4144 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4145 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4148 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4149 fdc_hw_init() is called at the beginning of the FDC
4150 setup. fdc_hw_init() must be provided by the board
4151 source code. It is used to make hardware dependant
4155 Most IDE controllers were designed to be connected with PCI
4156 interface. Only few of them were designed for AHB interface.
4157 When software is doing ATA command and data transfer to
4158 IDE devices through IDE-AHB controller, some additional
4159 registers accessing to these kind of IDE-AHB controller
4162 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4163 DO NOT CHANGE unless you know exactly what you're
4164 doing! (11-4) [MPC8xx/82xx systems only]
4166 - CONFIG_SYS_INIT_RAM_ADDR:
4168 Start address of memory area that can be used for
4169 initial data and stack; please note that this must be
4170 writable memory that is working WITHOUT special
4171 initialization, i. e. you CANNOT use normal RAM which
4172 will become available only after programming the
4173 memory controller and running certain initialization
4176 U-Boot uses the following memory types:
4177 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4178 - MPC824X: data cache
4179 - PPC4xx: data cache
4181 - CONFIG_SYS_GBL_DATA_OFFSET:
4183 Offset of the initial data structure in the memory
4184 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4185 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4186 data is located at the end of the available space
4187 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4188 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4189 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4190 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4193 On the MPC824X (or other systems that use the data
4194 cache for initial memory) the address chosen for
4195 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4196 point to an otherwise UNUSED address space between
4197 the top of RAM and the start of the PCI space.
4199 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4201 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4203 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4205 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4207 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4209 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4211 - CONFIG_SYS_OR_TIMING_SDRAM:
4214 - CONFIG_SYS_MAMR_PTA:
4215 periodic timer for refresh
4217 - CONFIG_SYS_DER: Debug Event Register (37-47)
4219 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4220 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4221 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4222 CONFIG_SYS_BR1_PRELIM:
4223 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4225 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4226 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4227 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4228 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4230 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4231 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4232 Machine Mode Register and Memory Periodic Timer
4233 Prescaler definitions (SDRAM timing)
4235 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4236 enable I2C microcode relocation patch (MPC8xx);
4237 define relocation offset in DPRAM [DSP2]
4239 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4240 enable SMC microcode relocation patch (MPC8xx);
4241 define relocation offset in DPRAM [SMC1]
4243 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4244 enable SPI microcode relocation patch (MPC8xx);
4245 define relocation offset in DPRAM [SCC4]
4247 - CONFIG_SYS_USE_OSCCLK:
4248 Use OSCM clock mode on MBX8xx board. Be careful,
4249 wrong setting might damage your board. Read
4250 doc/README.MBX before setting this variable!
4252 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4253 Offset of the bootmode word in DPRAM used by post
4254 (Power On Self Tests). This definition overrides
4255 #define'd default value in commproc.h resp.
4258 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4259 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4260 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4261 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4262 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4263 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4264 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4265 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4266 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4268 - CONFIG_PCI_DISABLE_PCIE:
4269 Disable PCI-Express on systems where it is supported but not
4272 - CONFIG_PCI_ENUM_ONLY
4273 Only scan through and get the devices on the busses.
4274 Don't do any setup work, presumably because someone or
4275 something has already done it, and we don't need to do it
4276 a second time. Useful for platforms that are pre-booted
4277 by coreboot or similar.
4279 - CONFIG_PCI_INDIRECT_BRIDGE:
4280 Enable support for indirect PCI bridges.
4283 Chip has SRIO or not
4286 Board has SRIO 1 port available
4289 Board has SRIO 2 port available
4291 - CONFIG_SRIO_PCIE_BOOT_MASTER
4292 Board can support master function for Boot from SRIO and PCIE
4294 - CONFIG_SYS_SRIOn_MEM_VIRT:
4295 Virtual Address of SRIO port 'n' memory region
4297 - CONFIG_SYS_SRIOn_MEM_PHYS:
4298 Physical Address of SRIO port 'n' memory region
4300 - CONFIG_SYS_SRIOn_MEM_SIZE:
4301 Size of SRIO port 'n' memory region
4303 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4304 Defined to tell the NAND controller that the NAND chip is using
4306 Not all NAND drivers use this symbol.
4307 Example of drivers that use it:
4308 - drivers/mtd/nand/ndfc.c
4309 - drivers/mtd/nand/mxc_nand.c
4311 - CONFIG_SYS_NDFC_EBC0_CFG
4312 Sets the EBC0_CFG register for the NDFC. If not defined
4313 a default value will be used.
4316 Get DDR timing information from an I2C EEPROM. Common
4317 with pluggable memory modules such as SODIMMs
4320 I2C address of the SPD EEPROM
4322 - CONFIG_SYS_SPD_BUS_NUM
4323 If SPD EEPROM is on an I2C bus other than the first
4324 one, specify here. Note that the value must resolve
4325 to something your driver can deal with.
4327 - CONFIG_SYS_DDR_RAW_TIMING
4328 Get DDR timing information from other than SPD. Common with
4329 soldered DDR chips onboard without SPD. DDR raw timing
4330 parameters are extracted from datasheet and hard-coded into
4331 header files or board specific files.
4333 - CONFIG_FSL_DDR_INTERACTIVE
4334 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4336 - CONFIG_SYS_83XX_DDR_USES_CS0
4337 Only for 83xx systems. If specified, then DDR should
4338 be configured using CS0 and CS1 instead of CS2 and CS3.
4340 - CONFIG_ETHER_ON_FEC[12]
4341 Define to enable FEC[12] on a 8xx series processor.
4343 - CONFIG_FEC[12]_PHY
4344 Define to the hardcoded PHY address which corresponds
4345 to the given FEC; i. e.
4346 #define CONFIG_FEC1_PHY 4
4347 means that the PHY with address 4 is connected to FEC1
4349 When set to -1, means to probe for first available.
4351 - CONFIG_FEC[12]_PHY_NORXERR
4352 The PHY does not have a RXERR line (RMII only).
4353 (so program the FEC to ignore it).
4356 Enable RMII mode for all FECs.
4357 Note that this is a global option, we can't
4358 have one FEC in standard MII mode and another in RMII mode.
4360 - CONFIG_CRC32_VERIFY
4361 Add a verify option to the crc32 command.
4364 => crc32 -v <address> <count> <crc32>
4366 Where address/count indicate a memory area
4367 and crc32 is the correct crc32 which the
4371 Add the "loopw" memory command. This only takes effect if
4372 the memory commands are activated globally (CONFIG_CMD_MEM).
4375 Add the "mdc" and "mwc" memory commands. These are cyclic
4380 This command will print 4 bytes (10,11,12,13) each 500 ms.
4382 => mwc.l 100 12345678 10
4383 This command will write 12345678 to address 100 all 10 ms.
4385 This only takes effect if the memory commands are activated
4386 globally (CONFIG_CMD_MEM).
4388 - CONFIG_SKIP_LOWLEVEL_INIT
4389 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4390 low level initializations (like setting up the memory
4391 controller) are omitted and/or U-Boot does not
4392 relocate itself into RAM.
4394 Normally this variable MUST NOT be defined. The only
4395 exception is when U-Boot is loaded (to RAM) by some
4396 other boot loader or by a debugger which performs
4397 these initializations itself.
4400 Modifies the behaviour of start.S when compiling a loader
4401 that is executed before the actual U-Boot. E.g. when
4402 compiling a NAND SPL.
4405 Modifies the behaviour of start.S when compiling a loader
4406 that is executed after the SPL and before the actual U-Boot.
4407 It is loaded by the SPL.
4409 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4410 Only for 85xx systems. If this variable is specified, the section
4411 .resetvec is not kept and the section .bootpg is placed in the
4412 previous 4k of the .text section.
4414 - CONFIG_ARCH_MAP_SYSMEM
4415 Generally U-Boot (and in particular the md command) uses
4416 effective address. It is therefore not necessary to regard
4417 U-Boot address as virtual addresses that need to be translated
4418 to physical addresses. However, sandbox requires this, since
4419 it maintains its own little RAM buffer which contains all
4420 addressable memory. This option causes some memory accesses
4421 to be mapped through map_sysmem() / unmap_sysmem().
4423 - CONFIG_USE_ARCH_MEMCPY
4424 CONFIG_USE_ARCH_MEMSET
4425 If these options are used a optimized version of memcpy/memset will
4426 be used if available. These functions may be faster under some
4427 conditions but may increase the binary size.
4429 - CONFIG_X86_RESET_VECTOR
4430 If defined, the x86 reset vector code is included. This is not
4431 needed when U-Boot is running from Coreboot.
4434 Defines the MPU clock speed (in MHz).
4436 NOTE : currently only supported on AM335x platforms.
4438 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4439 Enables the RTC32K OSC on AM33xx based plattforms
4441 Freescale QE/FMAN Firmware Support:
4442 -----------------------------------
4444 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4445 loading of "firmware", which is encoded in the QE firmware binary format.
4446 This firmware often needs to be loaded during U-Boot booting, so macros
4447 are used to identify the storage device (NOR flash, SPI, etc) and the address
4450 - CONFIG_SYS_QE_FMAN_FW_ADDR
4451 The address in the storage device where the firmware is located. The
4452 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4455 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4456 The maximum possible size of the firmware. The firmware binary format
4457 has a field that specifies the actual size of the firmware, but it
4458 might not be possible to read any part of the firmware unless some
4459 local storage is allocated to hold the entire firmware first.
4461 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4462 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4463 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4464 virtual address in NOR flash.
4466 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4467 Specifies that QE/FMAN firmware is located in NAND flash.
4468 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4470 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4471 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4472 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4474 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4475 Specifies that QE/FMAN firmware is located on the primary SPI
4476 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4478 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4479 Specifies that QE/FMAN firmware is located in the remote (master)
4480 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4481 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4482 window->master inbound window->master LAW->the ucode address in
4483 master's memory space.
4485 Building the Software:
4486 ======================
4488 Building U-Boot has been tested in several native build environments
4489 and in many different cross environments. Of course we cannot support
4490 all possibly existing versions of cross development tools in all
4491 (potentially obsolete) versions. In case of tool chain problems we
4492 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4493 which is extensively used to build and test U-Boot.
4495 If you are not using a native environment, it is assumed that you
4496 have GNU cross compiling tools available in your path. In this case,
4497 you must set the environment variable CROSS_COMPILE in your shell.
4498 Note that no changes to the Makefile or any other source files are
4499 necessary. For example using the ELDK on a 4xx CPU, please enter:
4501 $ CROSS_COMPILE=ppc_4xx-
4502 $ export CROSS_COMPILE
4504 Note: If you wish to generate Windows versions of the utilities in
4505 the tools directory you can use the MinGW toolchain
4506 (http://www.mingw.org). Set your HOST tools to the MinGW
4507 toolchain and execute 'make tools'. For example:
4509 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4511 Binaries such as tools/mkimage.exe will be created which can
4512 be executed on computers running Windows.
4514 U-Boot is intended to be simple to build. After installing the
4515 sources you must configure U-Boot for one specific board type. This
4520 where "NAME_config" is the name of one of the existing configu-
4521 rations; see boards.cfg for supported names.
4523 Note: for some board special configuration names may exist; check if
4524 additional information is available from the board vendor; for
4525 instance, the TQM823L systems are available without (standard)
4526 or with LCD support. You can select such additional "features"
4527 when choosing the configuration, i. e.
4530 - will configure for a plain TQM823L, i. e. no LCD support
4532 make TQM823L_LCD_config
4533 - will configure for a TQM823L with U-Boot console on LCD
4538 Finally, type "make all", and you should get some working U-Boot
4539 images ready for download to / installation on your system:
4541 - "u-boot.bin" is a raw binary image
4542 - "u-boot" is an image in ELF binary format
4543 - "u-boot.srec" is in Motorola S-Record format
4545 By default the build is performed locally and the objects are saved
4546 in the source directory. One of the two methods can be used to change
4547 this behavior and build U-Boot to some external directory:
4549 1. Add O= to the make command line invocations:
4551 make O=/tmp/build distclean
4552 make O=/tmp/build NAME_config
4553 make O=/tmp/build all
4555 2. Set environment variable BUILD_DIR to point to the desired location:
4557 export BUILD_DIR=/tmp/build
4562 Note that the command line "O=" setting overrides the BUILD_DIR environment
4566 Please be aware that the Makefiles assume you are using GNU make, so
4567 for instance on NetBSD you might need to use "gmake" instead of
4571 If the system board that you have is not listed, then you will need
4572 to port U-Boot to your hardware platform. To do this, follow these
4575 1. Add a new configuration option for your board to the toplevel
4576 "boards.cfg" file, using the existing entries as examples.
4577 Follow the instructions there to keep the boards in order.
4578 2. Create a new directory to hold your board specific code. Add any
4579 files you need. In your board directory, you will need at least
4580 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4581 3. Create a new configuration file "include/configs/<board>.h" for
4583 3. If you're porting U-Boot to a new CPU, then also create a new
4584 directory to hold your CPU specific code. Add any files you need.
4585 4. Run "make <board>_config" with your new name.
4586 5. Type "make", and you should get a working "u-boot.srec" file
4587 to be installed on your target system.
4588 6. Debug and solve any problems that might arise.
4589 [Of course, this last step is much harder than it sounds.]
4592 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4593 ==============================================================
4595 If you have modified U-Boot sources (for instance added a new board
4596 or support for new devices, a new CPU, etc.) you are expected to
4597 provide feedback to the other developers. The feedback normally takes
4598 the form of a "patch", i. e. a context diff against a certain (latest
4599 official or latest in the git repository) version of U-Boot sources.
4601 But before you submit such a patch, please verify that your modifi-
4602 cation did not break existing code. At least make sure that *ALL* of
4603 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4604 just run the "MAKEALL" script, which will configure and build U-Boot
4605 for ALL supported system. Be warned, this will take a while. You can
4606 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4607 environment variable to the script, i. e. to use the ELDK cross tools
4610 CROSS_COMPILE=ppc_8xx- MAKEALL
4612 or to build on a native PowerPC system you can type
4614 CROSS_COMPILE=' ' MAKEALL
4616 When using the MAKEALL script, the default behaviour is to build
4617 U-Boot in the source directory. This location can be changed by
4618 setting the BUILD_DIR environment variable. Also, for each target
4619 built, the MAKEALL script saves two log files (<target>.ERR and
4620 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4621 location can be changed by setting the MAKEALL_LOGDIR environment
4622 variable. For example:
4624 export BUILD_DIR=/tmp/build
4625 export MAKEALL_LOGDIR=/tmp/log
4626 CROSS_COMPILE=ppc_8xx- MAKEALL
4628 With the above settings build objects are saved in the /tmp/build,
4629 log files are saved in the /tmp/log and the source tree remains clean
4630 during the whole build process.
4633 See also "U-Boot Porting Guide" below.
4636 Monitor Commands - Overview:
4637 ============================
4639 go - start application at address 'addr'
4640 run - run commands in an environment variable
4641 bootm - boot application image from memory
4642 bootp - boot image via network using BootP/TFTP protocol
4643 bootz - boot zImage from memory
4644 tftpboot- boot image via network using TFTP protocol
4645 and env variables "ipaddr" and "serverip"
4646 (and eventually "gatewayip")
4647 tftpput - upload a file via network using TFTP protocol
4648 rarpboot- boot image via network using RARP/TFTP protocol
4649 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4650 loads - load S-Record file over serial line
4651 loadb - load binary file over serial line (kermit mode)
4653 mm - memory modify (auto-incrementing)
4654 nm - memory modify (constant address)
4655 mw - memory write (fill)
4657 cmp - memory compare
4658 crc32 - checksum calculation
4659 i2c - I2C sub-system
4660 sspi - SPI utility commands
4661 base - print or set address offset
4662 printenv- print environment variables
4663 setenv - set environment variables
4664 saveenv - save environment variables to persistent storage
4665 protect - enable or disable FLASH write protection
4666 erase - erase FLASH memory
4667 flinfo - print FLASH memory information
4668 nand - NAND memory operations (see doc/README.nand)
4669 bdinfo - print Board Info structure
4670 iminfo - print header information for application image
4671 coninfo - print console devices and informations
4672 ide - IDE sub-system
4673 loop - infinite loop on address range
4674 loopw - infinite write loop on address range
4675 mtest - simple RAM test
4676 icache - enable or disable instruction cache
4677 dcache - enable or disable data cache
4678 reset - Perform RESET of the CPU
4679 echo - echo args to console
4680 version - print monitor version
4681 help - print online help
4682 ? - alias for 'help'
4685 Monitor Commands - Detailed Description:
4686 ========================================
4690 For now: just type "help <command>".
4693 Environment Variables:
4694 ======================
4696 U-Boot supports user configuration using Environment Variables which
4697 can be made persistent by saving to Flash memory.
4699 Environment Variables are set using "setenv", printed using
4700 "printenv", and saved to Flash using "saveenv". Using "setenv"
4701 without a value can be used to delete a variable from the
4702 environment. As long as you don't save the environment you are
4703 working with an in-memory copy. In case the Flash area containing the
4704 environment is erased by accident, a default environment is provided.
4706 Some configuration options can be set using Environment Variables.
4708 List of environment variables (most likely not complete):
4710 baudrate - see CONFIG_BAUDRATE
4712 bootdelay - see CONFIG_BOOTDELAY
4714 bootcmd - see CONFIG_BOOTCOMMAND
4716 bootargs - Boot arguments when booting an RTOS image
4718 bootfile - Name of the image to load with TFTP
4720 bootm_low - 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 lowest address allowed
4723 for use by the bootm command. See also "bootm_size"
4724 environment variable. Address defined by "bootm_low" is
4725 also the base of the initial memory mapping for the Linux
4726 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4729 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4730 This variable is given as a hexadecimal number and it
4731 defines the size of the memory region starting at base
4732 address bootm_low that is accessible by the Linux kernel
4733 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4734 as the default value if it is defined, and bootm_size is
4737 bootm_size - Memory range available for image processing in the bootm
4738 command can be restricted. This variable is given as
4739 a hexadecimal number and defines the size of the region
4740 allowed for use by the bootm command. See also "bootm_low"
4741 environment variable.
4743 updatefile - Location of the software update file on a TFTP server, used
4744 by the automatic software update feature. Please refer to
4745 documentation in doc/README.update for more details.
4747 autoload - if set to "no" (any string beginning with 'n'),
4748 "bootp" will just load perform a lookup of the
4749 configuration from the BOOTP server, but not try to
4750 load any image using TFTP
4752 autostart - if set to "yes", an image loaded using the "bootp",
4753 "rarpboot", "tftpboot" or "diskboot" commands will
4754 be automatically started (by internally calling
4757 If set to "no", a standalone image passed to the
4758 "bootm" command will be copied to the load address
4759 (and eventually uncompressed), but NOT be started.
4760 This can be used to load and uncompress arbitrary
4763 fdt_high - if set this restricts the maximum address that the
4764 flattened device tree will be copied into upon boot.
4765 For example, if you have a system with 1 GB memory
4766 at physical address 0x10000000, while Linux kernel
4767 only recognizes the first 704 MB as low memory, you
4768 may need to set fdt_high as 0x3C000000 to have the
4769 device tree blob be copied to the maximum address
4770 of the 704 MB low memory, so that Linux kernel can
4771 access it during the boot procedure.
4773 If this is set to the special value 0xFFFFFFFF then
4774 the fdt will not be copied at all on boot. For this
4775 to work it must reside in writable memory, have
4776 sufficient padding on the end of it for u-boot to
4777 add the information it needs into it, and the memory
4778 must be accessible by the kernel.
4780 fdtcontroladdr- if set this is the address of the control flattened
4781 device tree used by U-Boot when CONFIG_OF_CONTROL is
4784 i2cfast - (PPC405GP|PPC405EP only)
4785 if set to 'y' configures Linux I2C driver for fast
4786 mode (400kHZ). This environment variable is used in
4787 initialization code. So, for changes to be effective
4788 it must be saved and board must be reset.
4790 initrd_high - restrict positioning of initrd images:
4791 If this variable is not set, initrd images will be
4792 copied to the highest possible address in RAM; this
4793 is usually what you want since it allows for
4794 maximum initrd size. If for some reason you want to
4795 make sure that the initrd image is loaded below the
4796 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4797 variable to a value of "no" or "off" or "0".
4798 Alternatively, you can set it to a maximum upper
4799 address to use (U-Boot will still check that it
4800 does not overwrite the U-Boot stack and data).
4802 For instance, when you have a system with 16 MB
4803 RAM, and want to reserve 4 MB from use by Linux,
4804 you can do this by adding "mem=12M" to the value of
4805 the "bootargs" variable. However, now you must make
4806 sure that the initrd image is placed in the first
4807 12 MB as well - this can be done with
4809 setenv initrd_high 00c00000
4811 If you set initrd_high to 0xFFFFFFFF, this is an
4812 indication to U-Boot that all addresses are legal
4813 for the Linux kernel, including addresses in flash
4814 memory. In this case U-Boot will NOT COPY the
4815 ramdisk at all. This may be useful to reduce the
4816 boot time on your system, but requires that this
4817 feature is supported by your Linux kernel.
4819 ipaddr - IP address; needed for tftpboot command
4821 loadaddr - Default load address for commands like "bootp",
4822 "rarpboot", "tftpboot", "loadb" or "diskboot"
4824 loads_echo - see CONFIG_LOADS_ECHO
4826 serverip - TFTP server IP address; needed for tftpboot command
4828 bootretry - see CONFIG_BOOT_RETRY_TIME
4830 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4832 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4834 ethprime - controls which interface is used first.
4836 ethact - controls which interface is currently active.
4837 For example you can do the following
4839 => setenv ethact FEC
4840 => ping 192.168.0.1 # traffic sent on FEC
4841 => setenv ethact SCC
4842 => ping 10.0.0.1 # traffic sent on SCC
4844 ethrotate - When set to "no" U-Boot does not go through all
4845 available network interfaces.
4846 It just stays at the currently selected interface.
4848 netretry - When set to "no" each network operation will
4849 either succeed or fail without retrying.
4850 When set to "once" the network operation will
4851 fail when all the available network interfaces
4852 are tried once without success.
4853 Useful on scripts which control the retry operation
4856 npe_ucode - set load address for the NPE microcode
4858 silent_linux - If set then linux will be told to boot silently, by
4859 changing the console to be empty. If "yes" it will be
4860 made silent. If "no" it will not be made silent. If
4861 unset, then it will be made silent if the U-Boot console
4864 tftpsrcport - If this is set, the value is used for TFTP's
4867 tftpdstport - If this is set, the value is used for TFTP's UDP
4868 destination port instead of the Well Know Port 69.
4870 tftpblocksize - Block size to use for TFTP transfers; if not set,
4871 we use the TFTP server's default block size
4873 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4874 seconds, minimum value is 1000 = 1 second). Defines
4875 when a packet is considered to be lost so it has to
4876 be retransmitted. The default is 5000 = 5 seconds.
4877 Lowering this value may make downloads succeed
4878 faster in networks with high packet loss rates or
4879 with unreliable TFTP servers.
4881 vlan - When set to a value < 4095 the traffic over
4882 Ethernet is encapsulated/received over 802.1q
4885 The following image location variables contain the location of images
4886 used in booting. The "Image" column gives the role of the image and is
4887 not an environment variable name. The other columns are environment
4888 variable names. "File Name" gives the name of the file on a TFTP
4889 server, "RAM Address" gives the location in RAM the image will be
4890 loaded to, and "Flash Location" gives the image's address in NOR
4891 flash or offset in NAND flash.
4893 *Note* - these variables don't have to be defined for all boards, some
4894 boards currenlty use other variables for these purposes, and some
4895 boards use these variables for other purposes.
4897 Image File Name RAM Address Flash Location
4898 ----- --------- ----------- --------------
4899 u-boot u-boot u-boot_addr_r u-boot_addr
4900 Linux kernel bootfile kernel_addr_r kernel_addr
4901 device tree blob fdtfile fdt_addr_r fdt_addr
4902 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4904 The following environment variables may be used and automatically
4905 updated by the network boot commands ("bootp" and "rarpboot"),
4906 depending the information provided by your boot server:
4908 bootfile - see above
4909 dnsip - IP address of your Domain Name Server
4910 dnsip2 - IP address of your secondary Domain Name Server
4911 gatewayip - IP address of the Gateway (Router) to use
4912 hostname - Target hostname
4914 netmask - Subnet Mask
4915 rootpath - Pathname of the root filesystem on the NFS server
4916 serverip - see above
4919 There are two special Environment Variables:
4921 serial# - contains hardware identification information such
4922 as type string and/or serial number
4923 ethaddr - Ethernet address
4925 These variables can be set only once (usually during manufacturing of
4926 the board). U-Boot refuses to delete or overwrite these variables
4927 once they have been set once.
4930 Further special Environment Variables:
4932 ver - Contains the U-Boot version string as printed
4933 with the "version" command. This variable is
4934 readonly (see CONFIG_VERSION_VARIABLE).
4937 Please note that changes to some configuration parameters may take
4938 only effect after the next boot (yes, that's just like Windoze :-).
4941 Callback functions for environment variables:
4942 ---------------------------------------------
4944 For some environment variables, the behavior of u-boot needs to change
4945 when their values are changed. This functionailty allows functions to
4946 be associated with arbitrary variables. On creation, overwrite, or
4947 deletion, the callback will provide the opportunity for some side
4948 effect to happen or for the change to be rejected.
4950 The callbacks are named and associated with a function using the
4951 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4953 These callbacks are associated with variables in one of two ways. The
4954 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4955 in the board configuration to a string that defines a list of
4956 associations. The list must be in the following format:
4958 entry = variable_name[:callback_name]
4961 If the callback name is not specified, then the callback is deleted.
4962 Spaces are also allowed anywhere in the list.
4964 Callbacks can also be associated by defining the ".callbacks" variable
4965 with the same list format above. Any association in ".callbacks" will
4966 override any association in the static list. You can define
4967 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4968 ".callbacks" envirnoment variable in the default or embedded environment.
4971 Command Line Parsing:
4972 =====================
4974 There are two different command line parsers available with U-Boot:
4975 the old "simple" one, and the much more powerful "hush" shell:
4977 Old, simple command line parser:
4978 --------------------------------
4980 - supports environment variables (through setenv / saveenv commands)
4981 - several commands on one line, separated by ';'
4982 - variable substitution using "... ${name} ..." syntax
4983 - special characters ('$', ';') can be escaped by prefixing with '\',
4985 setenv bootcmd bootm \${address}
4986 - You can also escape text by enclosing in single apostrophes, for example:
4987 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4992 - similar to Bourne shell, with control structures like
4993 if...then...else...fi, for...do...done; while...do...done,
4994 until...do...done, ...
4995 - supports environment ("global") variables (through setenv / saveenv
4996 commands) and local shell variables (through standard shell syntax
4997 "name=value"); only environment variables can be used with "run"
5003 (1) If a command line (or an environment variable executed by a "run"
5004 command) contains several commands separated by semicolon, and
5005 one of these commands fails, then the remaining commands will be
5008 (2) If you execute several variables with one call to run (i. e.
5009 calling run with a list of variables as arguments), any failing
5010 command will cause "run" to terminate, i. e. the remaining
5011 variables are not executed.
5013 Note for Redundant Ethernet Interfaces:
5014 =======================================
5016 Some boards come with redundant Ethernet interfaces; U-Boot supports
5017 such configurations and is capable of automatic selection of a
5018 "working" interface when needed. MAC assignment works as follows:
5020 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5021 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5022 "eth1addr" (=>eth1), "eth2addr", ...
5024 If the network interface stores some valid MAC address (for instance
5025 in SROM), this is used as default address if there is NO correspon-
5026 ding setting in the environment; if the corresponding environment
5027 variable is set, this overrides the settings in the card; that means:
5029 o If the SROM has a valid MAC address, and there is no address in the
5030 environment, the SROM's address is used.
5032 o If there is no valid address in the SROM, and a definition in the
5033 environment exists, then the value from the environment variable is
5036 o If both the SROM and the environment contain a MAC address, and
5037 both addresses are the same, this MAC address is used.
5039 o If both the SROM and the environment contain a MAC address, and the
5040 addresses differ, the value from the environment is used and a
5043 o If neither SROM nor the environment contain a MAC address, an error
5046 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5047 will be programmed into hardware as part of the initialization process. This
5048 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5049 The naming convention is as follows:
5050 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5055 U-Boot is capable of booting (and performing other auxiliary operations on)
5056 images in two formats:
5058 New uImage format (FIT)
5059 -----------------------
5061 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5062 to Flattened Device Tree). It allows the use of images with multiple
5063 components (several kernels, ramdisks, etc.), with contents protected by
5064 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5070 Old image format is based on binary files which can be basically anything,
5071 preceded by a special header; see the definitions in include/image.h for
5072 details; basically, the header defines the following image properties:
5074 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5075 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5076 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5077 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5079 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5080 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5081 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5082 * Compression Type (uncompressed, gzip, bzip2)
5088 The header is marked by a special Magic Number, and both the header
5089 and the data portions of the image are secured against corruption by
5096 Although U-Boot should support any OS or standalone application
5097 easily, the main focus has always been on Linux during the design of
5100 U-Boot includes many features that so far have been part of some
5101 special "boot loader" code within the Linux kernel. Also, any
5102 "initrd" images to be used are no longer part of one big Linux image;
5103 instead, kernel and "initrd" are separate images. This implementation
5104 serves several purposes:
5106 - the same features can be used for other OS or standalone
5107 applications (for instance: using compressed images to reduce the
5108 Flash memory footprint)
5110 - it becomes much easier to port new Linux kernel versions because
5111 lots of low-level, hardware dependent stuff are done by U-Boot
5113 - the same Linux kernel image can now be used with different "initrd"
5114 images; of course this also means that different kernel images can
5115 be run with the same "initrd". This makes testing easier (you don't
5116 have to build a new "zImage.initrd" Linux image when you just
5117 change a file in your "initrd"). Also, a field-upgrade of the
5118 software is easier now.
5124 Porting Linux to U-Boot based systems:
5125 ---------------------------------------
5127 U-Boot cannot save you from doing all the necessary modifications to
5128 configure the Linux device drivers for use with your target hardware
5129 (no, we don't intend to provide a full virtual machine interface to
5132 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5134 Just make sure your machine specific header file (for instance
5135 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5136 Information structure as we define in include/asm-<arch>/u-boot.h,
5137 and make sure that your definition of IMAP_ADDR uses the same value
5138 as your U-Boot configuration in CONFIG_SYS_IMMR.
5141 Configuring the Linux kernel:
5142 -----------------------------
5144 No specific requirements for U-Boot. Make sure you have some root
5145 device (initial ramdisk, NFS) for your target system.
5148 Building a Linux Image:
5149 -----------------------
5151 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5152 not used. If you use recent kernel source, a new build target
5153 "uImage" will exist which automatically builds an image usable by
5154 U-Boot. Most older kernels also have support for a "pImage" target,
5155 which was introduced for our predecessor project PPCBoot and uses a
5156 100% compatible format.
5165 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5166 encapsulate a compressed Linux kernel image with header information,
5167 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5169 * build a standard "vmlinux" kernel image (in ELF binary format):
5171 * convert the kernel into a raw binary image:
5173 ${CROSS_COMPILE}-objcopy -O binary \
5174 -R .note -R .comment \
5175 -S vmlinux linux.bin
5177 * compress the binary image:
5181 * package compressed binary image for U-Boot:
5183 mkimage -A ppc -O linux -T kernel -C gzip \
5184 -a 0 -e 0 -n "Linux Kernel Image" \
5185 -d linux.bin.gz uImage
5188 The "mkimage" tool can also be used to create ramdisk images for use
5189 with U-Boot, either separated from the Linux kernel image, or
5190 combined into one file. "mkimage" encapsulates the images with a 64
5191 byte header containing information about target architecture,
5192 operating system, image type, compression method, entry points, time
5193 stamp, CRC32 checksums, etc.
5195 "mkimage" can be called in two ways: to verify existing images and
5196 print the header information, or to build new images.
5198 In the first form (with "-l" option) mkimage lists the information
5199 contained in the header of an existing U-Boot image; this includes
5200 checksum verification:
5202 tools/mkimage -l image
5203 -l ==> list image header information
5205 The second form (with "-d" option) is used to build a U-Boot image
5206 from a "data file" which is used as image payload:
5208 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5209 -n name -d data_file image
5210 -A ==> set architecture to 'arch'
5211 -O ==> set operating system to 'os'
5212 -T ==> set image type to 'type'
5213 -C ==> set compression type 'comp'
5214 -a ==> set load address to 'addr' (hex)
5215 -e ==> set entry point to 'ep' (hex)
5216 -n ==> set image name to 'name'
5217 -d ==> use image data from 'datafile'
5219 Right now, all Linux kernels for PowerPC systems use the same load
5220 address (0x00000000), but the entry point address depends on the
5223 - 2.2.x kernels have the entry point at 0x0000000C,
5224 - 2.3.x and later kernels have the entry point at 0x00000000.
5226 So a typical call to build a U-Boot image would read:
5228 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5229 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5230 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5231 > examples/uImage.TQM850L
5232 Image Name: 2.4.4 kernel for TQM850L
5233 Created: Wed Jul 19 02:34:59 2000
5234 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5235 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5236 Load Address: 0x00000000
5237 Entry Point: 0x00000000
5239 To verify the contents of the image (or check for corruption):
5241 -> tools/mkimage -l examples/uImage.TQM850L
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 (gzip compressed)
5245 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5246 Load Address: 0x00000000
5247 Entry Point: 0x00000000
5249 NOTE: for embedded systems where boot time is critical you can trade
5250 speed for memory and install an UNCOMPRESSED image instead: this
5251 needs more space in Flash, but boots much faster since it does not
5252 need to be uncompressed:
5254 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5255 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5256 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5257 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5258 > examples/uImage.TQM850L-uncompressed
5259 Image Name: 2.4.4 kernel for TQM850L
5260 Created: Wed Jul 19 02:34:59 2000
5261 Image Type: PowerPC Linux Kernel Image (uncompressed)
5262 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5263 Load Address: 0x00000000
5264 Entry Point: 0x00000000
5267 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5268 when your kernel is intended to use an initial ramdisk:
5270 -> tools/mkimage -n 'Simple Ramdisk Image' \
5271 > -A ppc -O linux -T ramdisk -C gzip \
5272 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5273 Image Name: Simple Ramdisk Image
5274 Created: Wed Jan 12 14:01:50 2000
5275 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5276 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5277 Load Address: 0x00000000
5278 Entry Point: 0x00000000
5280 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5281 option performs the converse operation of the mkimage's second form (the "-d"
5282 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5285 tools/dumpimage -i image -p position data_file
5286 -i ==> extract from the 'image' a specific 'data_file', \
5287 indexed by 'position'
5290 Installing a Linux Image:
5291 -------------------------
5293 To downloading a U-Boot image over the serial (console) interface,
5294 you must convert the image to S-Record format:
5296 objcopy -I binary -O srec examples/image examples/image.srec
5298 The 'objcopy' does not understand the information in the U-Boot
5299 image header, so the resulting S-Record file will be relative to
5300 address 0x00000000. To load it to a given address, you need to
5301 specify the target address as 'offset' parameter with the 'loads'
5304 Example: install the image to address 0x40100000 (which on the
5305 TQM8xxL is in the first Flash bank):
5307 => erase 40100000 401FFFFF
5313 ## Ready for S-Record download ...
5314 ~>examples/image.srec
5315 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5317 15989 15990 15991 15992
5318 [file transfer complete]
5320 ## Start Addr = 0x00000000
5323 You can check the success of the download using the 'iminfo' command;
5324 this includes a checksum verification so you can be sure no data
5325 corruption happened:
5329 ## Checking Image at 40100000 ...
5330 Image Name: 2.2.13 for initrd on TQM850L
5331 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5332 Data Size: 335725 Bytes = 327 kB = 0 MB
5333 Load Address: 00000000
5334 Entry Point: 0000000c
5335 Verifying Checksum ... OK
5341 The "bootm" command is used to boot an application that is stored in
5342 memory (RAM or Flash). In case of a Linux kernel image, the contents
5343 of the "bootargs" environment variable is passed to the kernel as
5344 parameters. You can check and modify this variable using the
5345 "printenv" and "setenv" commands:
5348 => printenv bootargs
5349 bootargs=root=/dev/ram
5351 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5353 => printenv bootargs
5354 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5357 ## Booting Linux kernel at 40020000 ...
5358 Image Name: 2.2.13 for NFS on TQM850L
5359 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5360 Data Size: 381681 Bytes = 372 kB = 0 MB
5361 Load Address: 00000000
5362 Entry Point: 0000000c
5363 Verifying Checksum ... OK
5364 Uncompressing Kernel Image ... OK
5365 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
5366 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5367 time_init: decrementer frequency = 187500000/60
5368 Calibrating delay loop... 49.77 BogoMIPS
5369 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5372 If you want to boot a Linux kernel with initial RAM disk, you pass
5373 the memory addresses of both the kernel and the initrd image (PPBCOOT
5374 format!) to the "bootm" command:
5376 => imi 40100000 40200000
5378 ## Checking Image 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
5386 ## Checking 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
5394 => bootm 40100000 40200000
5395 ## Booting Linux kernel at 40100000 ...
5396 Image Name: 2.2.13 for initrd on TQM850L
5397 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5398 Data Size: 335725 Bytes = 327 kB = 0 MB
5399 Load Address: 00000000
5400 Entry Point: 0000000c
5401 Verifying Checksum ... OK
5402 Uncompressing Kernel Image ... OK
5403 ## Loading RAMDisk Image at 40200000 ...
5404 Image Name: Simple Ramdisk Image
5405 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5406 Data Size: 566530 Bytes = 553 kB = 0 MB
5407 Load Address: 00000000
5408 Entry Point: 00000000
5409 Verifying Checksum ... OK
5410 Loading Ramdisk ... OK
5411 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
5412 Boot arguments: root=/dev/ram
5413 time_init: decrementer frequency = 187500000/60
5414 Calibrating delay loop... 49.77 BogoMIPS
5416 RAMDISK: Compressed image found at block 0
5417 VFS: Mounted root (ext2 filesystem).
5421 Boot Linux and pass a flat device tree:
5424 First, U-Boot must be compiled with the appropriate defines. See the section
5425 titled "Linux Kernel Interface" above for a more in depth explanation. The
5426 following is an example of how to start a kernel and pass an updated
5432 oft=oftrees/mpc8540ads.dtb
5433 => tftp $oftaddr $oft
5434 Speed: 1000, full duplex
5436 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5437 Filename 'oftrees/mpc8540ads.dtb'.
5438 Load address: 0x300000
5441 Bytes transferred = 4106 (100a hex)
5442 => tftp $loadaddr $bootfile
5443 Speed: 1000, full duplex
5445 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5447 Load address: 0x200000
5448 Loading:############
5450 Bytes transferred = 1029407 (fb51f hex)
5455 => bootm $loadaddr - $oftaddr
5456 ## Booting image at 00200000 ...
5457 Image Name: Linux-2.6.17-dirty
5458 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5459 Data Size: 1029343 Bytes = 1005.2 kB
5460 Load Address: 00000000
5461 Entry Point: 00000000
5462 Verifying Checksum ... OK
5463 Uncompressing Kernel Image ... OK
5464 Booting using flat device tree at 0x300000
5465 Using MPC85xx ADS machine description
5466 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5470 More About U-Boot Image Types:
5471 ------------------------------
5473 U-Boot supports the following image types:
5475 "Standalone Programs" are directly runnable in the environment
5476 provided by U-Boot; it is expected that (if they behave
5477 well) you can continue to work in U-Boot after return from
5478 the Standalone Program.
5479 "OS Kernel Images" are usually images of some Embedded OS which
5480 will take over control completely. Usually these programs
5481 will install their own set of exception handlers, device
5482 drivers, set up the MMU, etc. - this means, that you cannot
5483 expect to re-enter U-Boot except by resetting the CPU.
5484 "RAMDisk Images" are more or less just data blocks, and their
5485 parameters (address, size) are passed to an OS kernel that is
5487 "Multi-File Images" contain several images, typically an OS
5488 (Linux) kernel image and one or more data images like
5489 RAMDisks. This construct is useful for instance when you want
5490 to boot over the network using BOOTP etc., where the boot
5491 server provides just a single image file, but you want to get
5492 for instance an OS kernel and a RAMDisk image.
5494 "Multi-File Images" start with a list of image sizes, each
5495 image size (in bytes) specified by an "uint32_t" in network
5496 byte order. This list is terminated by an "(uint32_t)0".
5497 Immediately after the terminating 0 follow the images, one by
5498 one, all aligned on "uint32_t" boundaries (size rounded up to
5499 a multiple of 4 bytes).
5501 "Firmware Images" are binary images containing firmware (like
5502 U-Boot or FPGA images) which usually will be programmed to
5505 "Script files" are command sequences that will be executed by
5506 U-Boot's command interpreter; this feature is especially
5507 useful when you configure U-Boot to use a real shell (hush)
5508 as command interpreter.
5510 Booting the Linux zImage:
5511 -------------------------
5513 On some platforms, it's possible to boot Linux zImage. This is done
5514 using the "bootz" command. The syntax of "bootz" command is the same
5515 as the syntax of "bootm" command.
5517 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5518 kernel with raw initrd images. The syntax is slightly different, the
5519 address of the initrd must be augmented by it's size, in the following
5520 format: "<initrd addres>:<initrd size>".
5526 One of the features of U-Boot is that you can dynamically load and
5527 run "standalone" applications, which can use some resources of
5528 U-Boot like console I/O functions or interrupt services.
5530 Two simple examples are included with the sources:
5535 'examples/hello_world.c' contains a small "Hello World" Demo
5536 application; it is automatically compiled when you build U-Boot.
5537 It's configured to run at address 0x00040004, so you can play with it
5541 ## Ready for S-Record download ...
5542 ~>examples/hello_world.srec
5543 1 2 3 4 5 6 7 8 9 10 11 ...
5544 [file transfer complete]
5546 ## Start Addr = 0x00040004
5548 => go 40004 Hello World! This is a test.
5549 ## Starting application at 0x00040004 ...
5560 Hit any key to exit ...
5562 ## Application terminated, rc = 0x0
5564 Another example, which demonstrates how to register a CPM interrupt
5565 handler with the U-Boot code, can be found in 'examples/timer.c'.
5566 Here, a CPM timer is set up to generate an interrupt every second.
5567 The interrupt service routine is trivial, just printing a '.'
5568 character, but this is just a demo program. The application can be
5569 controlled by the following keys:
5571 ? - print current values og the CPM Timer registers
5572 b - enable interrupts and start timer
5573 e - stop timer and disable interrupts
5574 q - quit application
5577 ## Ready for S-Record download ...
5578 ~>examples/timer.srec
5579 1 2 3 4 5 6 7 8 9 10 11 ...
5580 [file transfer complete]
5582 ## Start Addr = 0x00040004
5585 ## Starting application at 0x00040004 ...
5588 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5591 [q, b, e, ?] Set interval 1000000 us
5594 [q, b, e, ?] ........
5595 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5598 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5601 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5604 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5606 [q, b, e, ?] ...Stopping timer
5608 [q, b, e, ?] ## Application terminated, rc = 0x0
5614 Over time, many people have reported problems when trying to use the
5615 "minicom" terminal emulation program for serial download. I (wd)
5616 consider minicom to be broken, and recommend not to use it. Under
5617 Unix, I recommend to use C-Kermit for general purpose use (and
5618 especially for kermit binary protocol download ("loadb" command), and
5619 use "cu" for S-Record download ("loads" command). See
5620 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5621 for help with kermit.
5624 Nevertheless, if you absolutely want to use it try adding this
5625 configuration to your "File transfer protocols" section:
5627 Name Program Name U/D FullScr IO-Red. Multi
5628 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5629 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5635 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5636 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5638 Building requires a cross environment; it is known to work on
5639 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5640 need gmake since the Makefiles are not compatible with BSD make).
5641 Note that the cross-powerpc package does not install include files;
5642 attempting to build U-Boot will fail because <machine/ansi.h> is
5643 missing. This file has to be installed and patched manually:
5645 # cd /usr/pkg/cross/powerpc-netbsd/include
5647 # ln -s powerpc machine
5648 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5649 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5651 Native builds *don't* work due to incompatibilities between native
5652 and U-Boot include files.
5654 Booting assumes that (the first part of) the image booted is a
5655 stage-2 loader which in turn loads and then invokes the kernel
5656 proper. Loader sources will eventually appear in the NetBSD source
5657 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5658 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5661 Implementation Internals:
5662 =========================
5664 The following is not intended to be a complete description of every
5665 implementation detail. However, it should help to understand the
5666 inner workings of U-Boot and make it easier to port it to custom
5670 Initial Stack, Global Data:
5671 ---------------------------
5673 The implementation of U-Boot is complicated by the fact that U-Boot
5674 starts running out of ROM (flash memory), usually without access to
5675 system RAM (because the memory controller is not initialized yet).
5676 This means that we don't have writable Data or BSS segments, and BSS
5677 is not initialized as zero. To be able to get a C environment working
5678 at all, we have to allocate at least a minimal stack. Implementation
5679 options for this are defined and restricted by the CPU used: Some CPU
5680 models provide on-chip memory (like the IMMR area on MPC8xx and
5681 MPC826x processors), on others (parts of) the data cache can be
5682 locked as (mis-) used as memory, etc.
5684 Chris Hallinan posted a good summary of these issues to the
5685 U-Boot mailing list:
5687 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5688 From: "Chris Hallinan" <clh@net1plus.com>
5689 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5692 Correct me if I'm wrong, folks, but the way I understand it
5693 is this: Using DCACHE as initial RAM for Stack, etc, does not
5694 require any physical RAM backing up the cache. The cleverness
5695 is that the cache is being used as a temporary supply of
5696 necessary storage before the SDRAM controller is setup. It's
5697 beyond the scope of this list to explain the details, but you
5698 can see how this works by studying the cache architecture and
5699 operation in the architecture and processor-specific manuals.
5701 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5702 is another option for the system designer to use as an
5703 initial stack/RAM area prior to SDRAM being available. Either
5704 option should work for you. Using CS 4 should be fine if your
5705 board designers haven't used it for something that would
5706 cause you grief during the initial boot! It is frequently not
5709 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5710 with your processor/board/system design. The default value
5711 you will find in any recent u-boot distribution in
5712 walnut.h should work for you. I'd set it to a value larger
5713 than your SDRAM module. If you have a 64MB SDRAM module, set
5714 it above 400_0000. Just make sure your board has no resources
5715 that are supposed to respond to that address! That code in
5716 start.S has been around a while and should work as is when
5717 you get the config right.
5722 It is essential to remember this, since it has some impact on the C
5723 code for the initialization procedures:
5725 * Initialized global data (data segment) is read-only. Do not attempt
5728 * Do not use any uninitialized global data (or implicitely initialized
5729 as zero data - BSS segment) at all - this is undefined, initiali-
5730 zation is performed later (when relocating to RAM).
5732 * Stack space is very limited. Avoid big data buffers or things like
5735 Having only the stack as writable memory limits means we cannot use
5736 normal global data to share information beween the code. But it
5737 turned out that the implementation of U-Boot can be greatly
5738 simplified by making a global data structure (gd_t) available to all
5739 functions. We could pass a pointer to this data as argument to _all_
5740 functions, but this would bloat the code. Instead we use a feature of
5741 the GCC compiler (Global Register Variables) to share the data: we
5742 place a pointer (gd) to the global data into a register which we
5743 reserve for this purpose.
5745 When choosing a register for such a purpose we are restricted by the
5746 relevant (E)ABI specifications for the current architecture, and by
5747 GCC's implementation.
5749 For PowerPC, the following registers have specific use:
5751 R2: reserved for system use
5752 R3-R4: parameter passing and return values
5753 R5-R10: parameter passing
5754 R13: small data area pointer
5758 (U-Boot also uses R12 as internal GOT pointer. r12
5759 is a volatile register so r12 needs to be reset when
5760 going back and forth between asm and C)
5762 ==> U-Boot will use R2 to hold a pointer to the global data
5764 Note: on PPC, we could use a static initializer (since the
5765 address of the global data structure is known at compile time),
5766 but it turned out that reserving a register results in somewhat
5767 smaller code - although the code savings are not that big (on
5768 average for all boards 752 bytes for the whole U-Boot image,
5769 624 text + 127 data).
5771 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5772 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5774 ==> U-Boot will use P3 to hold a pointer to the global data
5776 On ARM, the following registers are used:
5778 R0: function argument word/integer result
5779 R1-R3: function argument word
5780 R9: platform specific
5781 R10: stack limit (used only if stack checking is enabled)
5782 R11: argument (frame) pointer
5783 R12: temporary workspace
5786 R15: program counter
5788 ==> U-Boot will use R9 to hold a pointer to the global data
5790 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5792 On Nios II, the ABI is documented here:
5793 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5795 ==> U-Boot will use gp to hold a pointer to the global data
5797 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5798 to access small data sections, so gp is free.
5800 On NDS32, the following registers are used:
5802 R0-R1: argument/return
5804 R15: temporary register for assembler
5805 R16: trampoline register
5806 R28: frame pointer (FP)
5807 R29: global pointer (GP)
5808 R30: link register (LP)
5809 R31: stack pointer (SP)
5810 PC: program counter (PC)
5812 ==> U-Boot will use R10 to hold a pointer to the global data
5814 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5815 or current versions of GCC may "optimize" the code too much.
5820 U-Boot runs in system state and uses physical addresses, i.e. the
5821 MMU is not used either for address mapping nor for memory protection.
5823 The available memory is mapped to fixed addresses using the memory
5824 controller. In this process, a contiguous block is formed for each
5825 memory type (Flash, SDRAM, SRAM), even when it consists of several
5826 physical memory banks.
5828 U-Boot is installed in the first 128 kB of the first Flash bank (on
5829 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5830 booting and sizing and initializing DRAM, the code relocates itself
5831 to the upper end of DRAM. Immediately below the U-Boot code some
5832 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5833 configuration setting]. Below that, a structure with global Board
5834 Info data is placed, followed by the stack (growing downward).
5836 Additionally, some exception handler code is copied to the low 8 kB
5837 of DRAM (0x00000000 ... 0x00001FFF).
5839 So a typical memory configuration with 16 MB of DRAM could look like
5842 0x0000 0000 Exception Vector code
5845 0x0000 2000 Free for Application Use
5851 0x00FB FF20 Monitor Stack (Growing downward)
5852 0x00FB FFAC Board Info Data and permanent copy of global data
5853 0x00FC 0000 Malloc Arena
5856 0x00FE 0000 RAM Copy of Monitor Code
5857 ... eventually: LCD or video framebuffer
5858 ... eventually: pRAM (Protected RAM - unchanged by reset)
5859 0x00FF FFFF [End of RAM]
5862 System Initialization:
5863 ----------------------
5865 In the reset configuration, U-Boot starts at the reset entry point
5866 (on most PowerPC systems at address 0x00000100). Because of the reset
5867 configuration for CS0# this is a mirror of the onboard Flash memory.
5868 To be able to re-map memory U-Boot then jumps to its link address.
5869 To be able to implement the initialization code in C, a (small!)
5870 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5871 which provide such a feature like MPC8xx or MPC8260), or in a locked
5872 part of the data cache. After that, U-Boot initializes the CPU core,
5873 the caches and the SIU.
5875 Next, all (potentially) available memory banks are mapped using a
5876 preliminary mapping. For example, we put them on 512 MB boundaries
5877 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5878 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5879 programmed for SDRAM access. Using the temporary configuration, a
5880 simple memory test is run that determines the size of the SDRAM
5883 When there is more than one SDRAM bank, and the banks are of
5884 different size, the largest is mapped first. For equal size, the first
5885 bank (CS2#) is mapped first. The first mapping is always for address
5886 0x00000000, with any additional banks following immediately to create
5887 contiguous memory starting from 0.
5889 Then, the monitor installs itself at the upper end of the SDRAM area
5890 and allocates memory for use by malloc() and for the global Board
5891 Info data; also, the exception vector code is copied to the low RAM
5892 pages, and the final stack is set up.
5894 Only after this relocation will you have a "normal" C environment;
5895 until that you are restricted in several ways, mostly because you are
5896 running from ROM, and because the code will have to be relocated to a
5900 U-Boot Porting Guide:
5901 ----------------------
5903 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5907 int main(int argc, char *argv[])
5909 sighandler_t no_more_time;
5911 signal(SIGALRM, no_more_time);
5912 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5914 if (available_money > available_manpower) {
5915 Pay consultant to port U-Boot;
5919 Download latest U-Boot source;
5921 Subscribe to u-boot mailing list;
5924 email("Hi, I am new to U-Boot, how do I get started?");
5927 Read the README file in the top level directory;
5928 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5929 Read applicable doc/*.README;
5930 Read the source, Luke;
5931 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5934 if (available_money > toLocalCurrency ($2500))
5937 Add a lot of aggravation and time;
5939 if (a similar board exists) { /* hopefully... */
5940 cp -a board/<similar> board/<myboard>
5941 cp include/configs/<similar>.h include/configs/<myboard>.h
5943 Create your own board support subdirectory;
5944 Create your own board include/configs/<myboard>.h file;
5946 Edit new board/<myboard> files
5947 Edit new include/configs/<myboard>.h
5952 Add / modify source code;
5956 email("Hi, I am having problems...");
5958 Send patch file to the U-Boot email list;
5959 if (reasonable critiques)
5960 Incorporate improvements from email list code review;
5962 Defend code as written;
5968 void no_more_time (int sig)
5977 All contributions to U-Boot should conform to the Linux kernel
5978 coding style; see the file "Documentation/CodingStyle" and the script
5979 "scripts/Lindent" in your Linux kernel source directory.
5981 Source files originating from a different project (for example the
5982 MTD subsystem) are generally exempt from these guidelines and are not
5983 reformated to ease subsequent migration to newer versions of those
5986 Please note that U-Boot is implemented in C (and to some small parts in
5987 Assembler); no C++ is used, so please do not use C++ style comments (//)
5990 Please also stick to the following formatting rules:
5991 - remove any trailing white space
5992 - use TAB characters for indentation and vertical alignment, not spaces
5993 - make sure NOT to use DOS '\r\n' line feeds
5994 - do not add more than 2 consecutive empty lines to source files
5995 - do not add trailing empty lines to source files
5997 Submissions which do not conform to the standards may be returned
5998 with a request to reformat the changes.
6004 Since the number of patches for U-Boot is growing, we need to
6005 establish some rules. Submissions which do not conform to these rules
6006 may be rejected, even when they contain important and valuable stuff.
6008 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6010 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6011 see http://lists.denx.de/mailman/listinfo/u-boot
6013 When you send a patch, please include the following information with
6016 * For bug fixes: a description of the bug and how your patch fixes
6017 this bug. Please try to include a way of demonstrating that the
6018 patch actually fixes something.
6020 * For new features: a description of the feature and your
6023 * A CHANGELOG entry as plaintext (separate from the patch)
6025 * For major contributions, your entry to the CREDITS file
6027 * When you add support for a new board, don't forget to add a
6028 maintainer e-mail address to the boards.cfg file, too.
6030 * If your patch adds new configuration options, don't forget to
6031 document these in the README file.
6033 * The patch itself. If you are using git (which is *strongly*
6034 recommended) you can easily generate the patch using the
6035 "git format-patch". If you then use "git send-email" to send it to
6036 the U-Boot mailing list, you will avoid most of the common problems
6037 with some other mail clients.
6039 If you cannot use git, use "diff -purN OLD NEW". If your version of
6040 diff does not support these options, then get the latest version of
6043 The current directory when running this command shall be the parent
6044 directory of the U-Boot source tree (i. e. please make sure that
6045 your patch includes sufficient directory information for the
6048 We prefer patches as plain text. MIME attachments are discouraged,
6049 and compressed attachments must not be used.
6051 * If one logical set of modifications affects or creates several
6052 files, all these changes shall be submitted in a SINGLE patch file.
6054 * Changesets that contain different, unrelated modifications shall be
6055 submitted as SEPARATE patches, one patch per changeset.
6060 * Before sending the patch, run the MAKEALL script on your patched
6061 source tree and make sure that no errors or warnings are reported
6062 for any of the boards.
6064 * Keep your modifications to the necessary minimum: A patch
6065 containing several unrelated changes or arbitrary reformats will be
6066 returned with a request to re-formatting / split it.
6068 * If you modify existing code, make sure that your new code does not
6069 add to the memory footprint of the code ;-) Small is beautiful!
6070 When adding new features, these should compile conditionally only
6071 (using #ifdef), and the resulting code with the new feature
6072 disabled must not need more memory than the old code without your
6075 * Remember that there is a size limit of 100 kB per message on the
6076 u-boot mailing list. Bigger patches will be moderated. If they are
6077 reasonable and not too big, they will be acknowledged. But patches
6078 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob