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_SAVEENV saveenv
926 CONFIG_CMD_FDC * Floppy Disk Support
927 CONFIG_CMD_FAT * FAT command support
928 CONFIG_CMD_FDOS * Dos diskette Support
929 CONFIG_CMD_FLASH flinfo, erase, protect
930 CONFIG_CMD_FPGA FPGA device initialization support
931 CONFIG_CMD_FUSE * Device fuse support
932 CONFIG_CMD_GETTIME * Get time since boot
933 CONFIG_CMD_GO * the 'go' command (exec code)
934 CONFIG_CMD_GREPENV * search environment
935 CONFIG_CMD_HASH * calculate hash / digest
936 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
937 CONFIG_CMD_I2C * I2C serial bus support
938 CONFIG_CMD_IDE * IDE harddisk support
939 CONFIG_CMD_IMI iminfo
940 CONFIG_CMD_IMLS List all images found in NOR flash
941 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
942 CONFIG_CMD_IMMAP * IMMR dump support
943 CONFIG_CMD_IMPORTENV * import an environment
944 CONFIG_CMD_INI * import data from an ini file into the env
945 CONFIG_CMD_IRQ * irqinfo
946 CONFIG_CMD_ITEST Integer/string test of 2 values
947 CONFIG_CMD_JFFS2 * JFFS2 Support
948 CONFIG_CMD_KGDB * kgdb
949 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
950 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
952 CONFIG_CMD_LOADB loadb
953 CONFIG_CMD_LOADS loads
954 CONFIG_CMD_MD5SUM * print md5 message digest
955 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
956 CONFIG_CMD_MEMINFO * Display detailed memory information
957 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
959 CONFIG_CMD_MEMTEST * mtest
960 CONFIG_CMD_MISC Misc functions like sleep etc
961 CONFIG_CMD_MMC * MMC memory mapped support
962 CONFIG_CMD_MII * MII utility commands
963 CONFIG_CMD_MTDPARTS * MTD partition support
964 CONFIG_CMD_NAND * NAND support
965 CONFIG_CMD_NET bootp, tftpboot, rarpboot
966 CONFIG_CMD_NFS NFS support
967 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
968 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
969 CONFIG_CMD_PCI * pciinfo
970 CONFIG_CMD_PCMCIA * PCMCIA support
971 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
973 CONFIG_CMD_PORTIO * Port I/O
974 CONFIG_CMD_READ * Read raw data from partition
975 CONFIG_CMD_REGINFO * Register dump
976 CONFIG_CMD_RUN run command in env variable
977 CONFIG_CMD_SANDBOX * sb command to access sandbox features
978 CONFIG_CMD_SAVES * save S record dump
979 CONFIG_CMD_SCSI * SCSI Support
980 CONFIG_CMD_SDRAM * print SDRAM configuration information
981 (requires CONFIG_CMD_I2C)
982 CONFIG_CMD_SETGETDCR Support for DCR Register access
984 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
985 CONFIG_CMD_SHA1SUM * print sha1 memory digest
986 (requires CONFIG_CMD_MEMORY)
987 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
988 CONFIG_CMD_SOURCE "source" command Support
989 CONFIG_CMD_SPI * SPI serial bus support
990 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
991 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
992 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
993 CONFIG_CMD_TIMER * access to the system tick timer
994 CONFIG_CMD_USB * USB support
995 CONFIG_CMD_CDP * Cisco Discover Protocol support
996 CONFIG_CMD_MFSL * Microblaze FSL support
997 CONFIG_CMD_XIMG Load part of Multi Image
1000 EXAMPLE: If you want all functions except of network
1001 support you can write:
1003 #include "config_cmd_all.h"
1004 #undef CONFIG_CMD_NET
1007 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1009 Note: Don't enable the "icache" and "dcache" commands
1010 (configuration option CONFIG_CMD_CACHE) unless you know
1011 what you (and your U-Boot users) are doing. Data
1012 cache cannot be enabled on systems like the 8xx or
1013 8260 (where accesses to the IMMR region must be
1014 uncached), and it cannot be disabled on all other
1015 systems where we (mis-) use the data cache to hold an
1016 initial stack and some data.
1019 XXX - this list needs to get updated!
1021 - Regular expression support:
1023 If this variable is defined, U-Boot is linked against
1024 the SLRE (Super Light Regular Expression) library,
1025 which adds regex support to some commands, as for
1026 example "env grep" and "setexpr".
1030 If this variable is defined, U-Boot will use a device tree
1031 to configure its devices, instead of relying on statically
1032 compiled #defines in the board file. This option is
1033 experimental and only available on a few boards. The device
1034 tree is available in the global data as gd->fdt_blob.
1036 U-Boot needs to get its device tree from somewhere. This can
1037 be done using one of the two options below:
1040 If this variable is defined, U-Boot will embed a device tree
1041 binary in its image. This device tree file should be in the
1042 board directory and called <soc>-<board>.dts. The binary file
1043 is then picked up in board_init_f() and made available through
1044 the global data structure as gd->blob.
1047 If this variable is defined, U-Boot will build a device tree
1048 binary. It will be called u-boot.dtb. Architecture-specific
1049 code will locate it at run-time. Generally this works by:
1051 cat u-boot.bin u-boot.dtb >image.bin
1053 and in fact, U-Boot does this for you, creating a file called
1054 u-boot-dtb.bin which is useful in the common case. You can
1055 still use the individual files if you need something more
1060 If this variable is defined, it enables watchdog
1061 support for the SoC. There must be support in the SoC
1062 specific code for a watchdog. For the 8xx and 8260
1063 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1064 register. When supported for a specific SoC is
1065 available, then no further board specific code should
1066 be needed to use it.
1069 When using a watchdog circuitry external to the used
1070 SoC, then define this variable and provide board
1071 specific code for the "hw_watchdog_reset" function.
1074 CONFIG_VERSION_VARIABLE
1075 If this variable is defined, an environment variable
1076 named "ver" is created by U-Boot showing the U-Boot
1077 version as printed by the "version" command.
1078 Any change to this variable will be reverted at the
1083 When CONFIG_CMD_DATE is selected, the type of the RTC
1084 has to be selected, too. Define exactly one of the
1087 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1088 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1089 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1090 CONFIG_RTC_MC146818 - use MC146818 RTC
1091 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1092 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1093 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1094 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1095 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1096 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1097 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1098 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1101 Note that if the RTC uses I2C, then the I2C interface
1102 must also be configured. See I2C Support, below.
1105 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1107 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1108 chip-ngpio pairs that tell the PCA953X driver the number of
1109 pins supported by a particular chip.
1111 Note that if the GPIO device uses I2C, then the I2C interface
1112 must also be configured. See I2C Support, below.
1114 - Timestamp Support:
1116 When CONFIG_TIMESTAMP is selected, the timestamp
1117 (date and time) of an image is printed by image
1118 commands like bootm or iminfo. This option is
1119 automatically enabled when you select CONFIG_CMD_DATE .
1121 - Partition Labels (disklabels) Supported:
1122 Zero or more of the following:
1123 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1124 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1125 Intel architecture, USB sticks, etc.
1126 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1127 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1128 bootloader. Note 2TB partition limit; see
1130 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1132 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1133 CONFIG_CMD_SCSI) you must configure support for at
1134 least one non-MTD partition type as well.
1137 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1138 board configurations files but used nowhere!
1140 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1141 be performed by calling the function
1142 ide_set_reset(int reset)
1143 which has to be defined in a board specific file
1148 Set this to enable ATAPI support.
1153 Set this to enable support for disks larger than 137GB
1154 Also look at CONFIG_SYS_64BIT_LBA.
1155 Whithout these , LBA48 support uses 32bit variables and will 'only'
1156 support disks up to 2.1TB.
1158 CONFIG_SYS_64BIT_LBA:
1159 When enabled, makes the IDE subsystem use 64bit sector addresses.
1163 At the moment only there is only support for the
1164 SYM53C8XX SCSI controller; define
1165 CONFIG_SCSI_SYM53C8XX to enable it.
1167 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1168 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1169 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1170 maximum numbers of LUNs, SCSI ID's and target
1172 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1174 The environment variable 'scsidevs' is set to the number of
1175 SCSI devices found during the last scan.
1177 - NETWORK Support (PCI):
1179 Support for Intel 8254x/8257x gigabit chips.
1182 Utility code for direct access to the SPI bus on Intel 8257x.
1183 This does not do anything useful unless you set at least one
1184 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1186 CONFIG_E1000_SPI_GENERIC
1187 Allow generic access to the SPI bus on the Intel 8257x, for
1188 example with the "sspi" command.
1191 Management command for E1000 devices. When used on devices
1192 with SPI support you can reprogram the EEPROM from U-Boot.
1194 CONFIG_E1000_FALLBACK_MAC
1195 default MAC for empty EEPROM after production.
1198 Support for Intel 82557/82559/82559ER chips.
1199 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1200 write routine for first time initialisation.
1203 Support for Digital 2114x chips.
1204 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1205 modem chip initialisation (KS8761/QS6611).
1208 Support for National dp83815 chips.
1211 Support for National dp8382[01] gigabit chips.
1213 - NETWORK Support (other):
1215 CONFIG_DRIVER_AT91EMAC
1216 Support for AT91RM9200 EMAC.
1219 Define this to use reduced MII inteface
1221 CONFIG_DRIVER_AT91EMAC_QUIET
1222 If this defined, the driver is quiet.
1223 The driver doen't show link status messages.
1225 CONFIG_CALXEDA_XGMAC
1226 Support for the Calxeda XGMAC device
1229 Support for SMSC's LAN91C96 chips.
1231 CONFIG_LAN91C96_BASE
1232 Define this to hold the physical address
1233 of the LAN91C96's I/O space
1235 CONFIG_LAN91C96_USE_32_BIT
1236 Define this to enable 32 bit addressing
1239 Support for SMSC's LAN91C111 chip
1241 CONFIG_SMC91111_BASE
1242 Define this to hold the physical address
1243 of the device (I/O space)
1245 CONFIG_SMC_USE_32_BIT
1246 Define this if data bus is 32 bits
1248 CONFIG_SMC_USE_IOFUNCS
1249 Define this to use i/o functions instead of macros
1250 (some hardware wont work with macros)
1252 CONFIG_DRIVER_TI_EMAC
1253 Support for davinci emac
1255 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1256 Define this if you have more then 3 PHYs.
1259 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1261 CONFIG_FTGMAC100_EGIGA
1262 Define this to use GE link update with gigabit PHY.
1263 Define this if FTGMAC100 is connected to gigabit PHY.
1264 If your system has 10/100 PHY only, it might not occur
1265 wrong behavior. Because PHY usually return timeout or
1266 useless data when polling gigabit status and gigabit
1267 control registers. This behavior won't affect the
1268 correctnessof 10/100 link speed update.
1271 Support for SMSC's LAN911x and LAN921x chips
1274 Define this to hold the physical address
1275 of the device (I/O space)
1277 CONFIG_SMC911X_32_BIT
1278 Define this if data bus is 32 bits
1280 CONFIG_SMC911X_16_BIT
1281 Define this if data bus is 16 bits. If your processor
1282 automatically converts one 32 bit word to two 16 bit
1283 words you may also try CONFIG_SMC911X_32_BIT.
1286 Support for Renesas on-chip Ethernet controller
1288 CONFIG_SH_ETHER_USE_PORT
1289 Define the number of ports to be used
1291 CONFIG_SH_ETHER_PHY_ADDR
1292 Define the ETH PHY's address
1294 CONFIG_SH_ETHER_CACHE_WRITEBACK
1295 If this option is set, the driver enables cache flush.
1299 Support TPM devices.
1302 Support for i2c bus TPM devices. Only one device
1303 per system is supported at this time.
1305 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1306 Define the the i2c bus number for the TPM device
1308 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1309 Define the TPM's address on the i2c bus
1311 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1312 Define the burst count bytes upper limit
1314 CONFIG_TPM_ATMEL_TWI
1315 Support for Atmel TWI TPM device. Requires I2C support.
1318 Support for generic parallel port TPM devices. Only one device
1319 per system is supported at this time.
1321 CONFIG_TPM_TIS_BASE_ADDRESS
1322 Base address where the generic TPM device is mapped
1323 to. Contemporary x86 systems usually map it at
1327 Add tpm monitor functions.
1328 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1329 provides monitor access to authorized functions.
1332 Define this to enable the TPM support library which provides
1333 functional interfaces to some TPM commands.
1334 Requires support for a TPM device.
1336 CONFIG_TPM_AUTH_SESSIONS
1337 Define this to enable authorized functions in the TPM library.
1338 Requires CONFIG_TPM and CONFIG_SHA1.
1341 At the moment only the UHCI host controller is
1342 supported (PIP405, MIP405, MPC5200); define
1343 CONFIG_USB_UHCI to enable it.
1344 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1345 and define CONFIG_USB_STORAGE to enable the USB
1348 Supported are USB Keyboards and USB Floppy drives
1350 MPC5200 USB requires additional defines:
1352 for 528 MHz Clock: 0x0001bbbb
1356 for differential drivers: 0x00001000
1357 for single ended drivers: 0x00005000
1358 for differential drivers on PSC3: 0x00000100
1359 for single ended drivers on PSC3: 0x00004100
1360 CONFIG_SYS_USB_EVENT_POLL
1361 May be defined to allow interrupt polling
1362 instead of using asynchronous interrupts
1364 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1365 txfilltuning field in the EHCI controller on reset.
1367 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1368 interval for usb hub power-on delay.(minimum 100msec)
1371 Define the below if you wish to use the USB console.
1372 Once firmware is rebuilt from a serial console issue the
1373 command "setenv stdin usbtty; setenv stdout usbtty" and
1374 attach your USB cable. The Unix command "dmesg" should print
1375 it has found a new device. The environment variable usbtty
1376 can be set to gserial or cdc_acm to enable your device to
1377 appear to a USB host as a Linux gserial device or a
1378 Common Device Class Abstract Control Model serial device.
1379 If you select usbtty = gserial you should be able to enumerate
1381 # modprobe usbserial vendor=0xVendorID product=0xProductID
1382 else if using cdc_acm, simply setting the environment
1383 variable usbtty to be cdc_acm should suffice. The following
1384 might be defined in YourBoardName.h
1387 Define this to build a UDC device
1390 Define this to have a tty type of device available to
1391 talk to the UDC device
1394 Define this to enable the high speed support for usb
1395 device and usbtty. If this feature is enabled, a routine
1396 int is_usbd_high_speed(void)
1397 also needs to be defined by the driver to dynamically poll
1398 whether the enumeration has succeded at high speed or full
1401 CONFIG_SYS_CONSOLE_IS_IN_ENV
1402 Define this if you want stdin, stdout &/or stderr to
1406 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1407 Derive USB clock from external clock "blah"
1408 - CONFIG_SYS_USB_EXTC_CLK 0x02
1410 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1411 Derive USB clock from brgclk
1412 - CONFIG_SYS_USB_BRG_CLK 0x04
1414 If you have a USB-IF assigned VendorID then you may wish to
1415 define your own vendor specific values either in BoardName.h
1416 or directly in usbd_vendor_info.h. If you don't define
1417 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1418 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1419 should pretend to be a Linux device to it's target host.
1421 CONFIG_USBD_MANUFACTURER
1422 Define this string as the name of your company for
1423 - CONFIG_USBD_MANUFACTURER "my company"
1425 CONFIG_USBD_PRODUCT_NAME
1426 Define this string as the name of your product
1427 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1429 CONFIG_USBD_VENDORID
1430 Define this as your assigned Vendor ID from the USB
1431 Implementors Forum. This *must* be a genuine Vendor ID
1432 to avoid polluting the USB namespace.
1433 - CONFIG_USBD_VENDORID 0xFFFF
1435 CONFIG_USBD_PRODUCTID
1436 Define this as the unique Product ID
1438 - CONFIG_USBD_PRODUCTID 0xFFFF
1440 Some USB device drivers may need to check USB cable attachment.
1441 In this case you can enable following config in BoardName.h:
1442 CONFIG_USB_CABLE_CHECK
1443 This enables function definition:
1444 - usb_cable_connected() in include/usb.h
1445 Implementation of this function is board-specific.
1447 - ULPI Layer Support:
1448 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1449 the generic ULPI layer. The generic layer accesses the ULPI PHY
1450 via the platform viewport, so you need both the genric layer and
1451 the viewport enabled. Currently only Chipidea/ARC based
1452 viewport is supported.
1453 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1454 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1455 If your ULPI phy needs a different reference clock than the
1456 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1457 the appropriate value in Hz.
1460 The MMC controller on the Intel PXA is supported. To
1461 enable this define CONFIG_MMC. The MMC can be
1462 accessed from the boot prompt by mapping the device
1463 to physical memory similar to flash. Command line is
1464 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1465 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1468 Support for Renesas on-chip MMCIF controller
1470 CONFIG_SH_MMCIF_ADDR
1471 Define the base address of MMCIF registers
1474 Define the clock frequency for MMCIF
1476 - USB Device Firmware Update (DFU) class support:
1478 This enables the USB portion of the DFU USB class
1481 This enables the command "dfu" which is used to have
1482 U-Boot create a DFU class device via USB. This command
1483 requires that the "dfu_alt_info" environment variable be
1484 set and define the alt settings to expose to the host.
1487 This enables support for exposing (e)MMC devices via DFU.
1490 This enables support for exposing NAND devices via DFU.
1493 This enables support for exposing RAM via DFU.
1494 Note: DFU spec refer to non-volatile memory usage, but
1495 allow usages beyond the scope of spec - here RAM usage,
1496 one that would help mostly the developer.
1498 CONFIG_SYS_DFU_DATA_BUF_SIZE
1499 Dfu transfer uses a buffer before writing data to the
1500 raw storage device. Make the size (in bytes) of this buffer
1501 configurable. The size of this buffer is also configurable
1502 through the "dfu_bufsiz" environment variable.
1504 CONFIG_SYS_DFU_MAX_FILE_SIZE
1505 When updating files rather than the raw storage device,
1506 we use a static buffer to copy the file into and then write
1507 the buffer once we've been given the whole file. Define
1508 this to the maximum filesize (in bytes) for the buffer.
1509 Default is 4 MiB if undefined.
1511 - Journaling Flash filesystem support:
1512 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1513 CONFIG_JFFS2_NAND_DEV
1514 Define these for a default partition on a NAND device
1516 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1517 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1518 Define these for a default partition on a NOR device
1520 CONFIG_SYS_JFFS_CUSTOM_PART
1521 Define this to create an own partition. You have to provide a
1522 function struct part_info* jffs2_part_info(int part_num)
1524 If you define only one JFFS2 partition you may also want to
1525 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1526 to disable the command chpart. This is the default when you
1527 have not defined a custom partition
1529 - FAT(File Allocation Table) filesystem write function support:
1532 Define this to enable support for saving memory data as a
1533 file in FAT formatted partition.
1535 This will also enable the command "fatwrite" enabling the
1536 user to write files to FAT.
1538 CBFS (Coreboot Filesystem) support
1541 Define this to enable support for reading from a Coreboot
1542 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1548 Define this to enable standard (PC-Style) keyboard
1552 Standard PC keyboard driver with US (is default) and
1553 GERMAN key layout (switch via environment 'keymap=de') support.
1554 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1555 for cfb_console. Supports cursor blinking.
1558 Enables a Chrome OS keyboard using the CROS_EC interface.
1559 This uses CROS_EC to communicate with a second microcontroller
1560 which provides key scans on request.
1565 Define this to enable video support (for output to
1568 CONFIG_VIDEO_CT69000
1570 Enable Chips & Technologies 69000 Video chip
1572 CONFIG_VIDEO_SMI_LYNXEM
1573 Enable Silicon Motion SMI 712/710/810 Video chip. The
1574 video output is selected via environment 'videoout'
1575 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1578 For the CT69000 and SMI_LYNXEM drivers, videomode is
1579 selected via environment 'videomode'. Two different ways
1581 - "videomode=num" 'num' is a standard LiLo mode numbers.
1582 Following standard modes are supported (* is default):
1584 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1585 -------------+---------------------------------------------
1586 8 bits | 0x301* 0x303 0x305 0x161 0x307
1587 15 bits | 0x310 0x313 0x316 0x162 0x319
1588 16 bits | 0x311 0x314 0x317 0x163 0x31A
1589 24 bits | 0x312 0x315 0x318 ? 0x31B
1590 -------------+---------------------------------------------
1591 (i.e. setenv videomode 317; saveenv; reset;)
1593 - "videomode=bootargs" all the video parameters are parsed
1594 from the bootargs. (See drivers/video/videomodes.c)
1597 CONFIG_VIDEO_SED13806
1598 Enable Epson SED13806 driver. This driver supports 8bpp
1599 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1600 or CONFIG_VIDEO_SED13806_16BPP
1603 Enable the Freescale DIU video driver. Reference boards for
1604 SOCs that have a DIU should define this macro to enable DIU
1605 support, and should also define these other macros:
1611 CONFIG_VIDEO_SW_CURSOR
1612 CONFIG_VGA_AS_SINGLE_DEVICE
1614 CONFIG_VIDEO_BMP_LOGO
1616 The DIU driver will look for the 'video-mode' environment
1617 variable, and if defined, enable the DIU as a console during
1618 boot. See the documentation file README.video for a
1619 description of this variable.
1623 Enable the VGA video / BIOS for x86. The alternative if you
1624 are using coreboot is to use the coreboot frame buffer
1631 Define this to enable a custom keyboard support.
1632 This simply calls drv_keyboard_init() which must be
1633 defined in your board-specific files.
1634 The only board using this so far is RBC823.
1636 - LCD Support: CONFIG_LCD
1638 Define this to enable LCD support (for output to LCD
1639 display); also select one of the supported displays
1640 by defining one of these:
1644 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1646 CONFIG_NEC_NL6448AC33:
1648 NEC NL6448AC33-18. Active, color, single scan.
1650 CONFIG_NEC_NL6448BC20
1652 NEC NL6448BC20-08. 6.5", 640x480.
1653 Active, color, single scan.
1655 CONFIG_NEC_NL6448BC33_54
1657 NEC NL6448BC33-54. 10.4", 640x480.
1658 Active, color, single scan.
1662 Sharp 320x240. Active, color, single scan.
1663 It isn't 16x9, and I am not sure what it is.
1665 CONFIG_SHARP_LQ64D341
1667 Sharp LQ64D341 display, 640x480.
1668 Active, color, single scan.
1672 HLD1045 display, 640x480.
1673 Active, color, single scan.
1677 Optrex CBL50840-2 NF-FW 99 22 M5
1679 Hitachi LMG6912RPFC-00T
1683 320x240. Black & white.
1685 Normally display is black on white background; define
1686 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1688 CONFIG_LCD_ALIGNMENT
1690 Normally the LCD is page-aligned (tyically 4KB). If this is
1691 defined then the LCD will be aligned to this value instead.
1692 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1693 here, since it is cheaper to change data cache settings on
1694 a per-section basis.
1696 CONFIG_CONSOLE_SCROLL_LINES
1698 When the console need to be scrolled, this is the number of
1699 lines to scroll by. It defaults to 1. Increasing this makes
1700 the console jump but can help speed up operation when scrolling
1705 Support drawing of RLE8-compressed bitmaps on the LCD.
1709 Enables an 'i2c edid' command which can read EDID
1710 information over I2C from an attached LCD display.
1712 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1714 If this option is set, the environment is checked for
1715 a variable "splashimage". If found, the usual display
1716 of logo, copyright and system information on the LCD
1717 is suppressed and the BMP image at the address
1718 specified in "splashimage" is loaded instead. The
1719 console is redirected to the "nulldev", too. This
1720 allows for a "silent" boot where a splash screen is
1721 loaded very quickly after power-on.
1723 CONFIG_SPLASHIMAGE_GUARD
1725 If this option is set, then U-Boot will prevent the environment
1726 variable "splashimage" from being set to a problematic address
1727 (see README.displaying-bmps and README.arm-unaligned-accesses).
1728 This option is useful for targets where, due to alignment
1729 restrictions, an improperly aligned BMP image will cause a data
1730 abort. If you think you will not have problems with unaligned
1731 accesses (for example because your toolchain prevents them)
1732 there is no need to set this option.
1734 CONFIG_SPLASH_SCREEN_ALIGN
1736 If this option is set the splash image can be freely positioned
1737 on the screen. Environment variable "splashpos" specifies the
1738 position as "x,y". If a positive number is given it is used as
1739 number of pixel from left/top. If a negative number is given it
1740 is used as number of pixel from right/bottom. You can also
1741 specify 'm' for centering the image.
1744 setenv splashpos m,m
1745 => image at center of screen
1747 setenv splashpos 30,20
1748 => image at x = 30 and y = 20
1750 setenv splashpos -10,m
1751 => vertically centered image
1752 at x = dspWidth - bmpWidth - 9
1754 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1756 If this option is set, additionally to standard BMP
1757 images, gzipped BMP images can be displayed via the
1758 splashscreen support or the bmp command.
1760 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1762 If this option is set, 8-bit RLE compressed BMP images
1763 can be displayed via the splashscreen support or the
1766 - Do compresssing for memory range:
1769 If this option is set, it would use zlib deflate method
1770 to compress the specified memory at its best effort.
1772 - Compression support:
1775 Enabled by default to support gzip compressed images.
1779 If this option is set, support for bzip2 compressed
1780 images is included. If not, only uncompressed and gzip
1781 compressed images are supported.
1783 NOTE: the bzip2 algorithm requires a lot of RAM, so
1784 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1789 If this option is set, support for lzma compressed
1792 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1793 requires an amount of dynamic memory that is given by the
1796 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1798 Where lc and lp stand for, respectively, Literal context bits
1799 and Literal pos bits.
1801 This value is upper-bounded by 14MB in the worst case. Anyway,
1802 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1803 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1804 a very small buffer.
1806 Use the lzmainfo tool to determinate the lc and lp values and
1807 then calculate the amount of needed dynamic memory (ensuring
1808 the appropriate CONFIG_SYS_MALLOC_LEN value).
1812 If this option is set, support for LZO compressed images
1818 The address of PHY on MII bus.
1820 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1822 The clock frequency of the MII bus
1826 If this option is set, support for speed/duplex
1827 detection of gigabit PHY is included.
1829 CONFIG_PHY_RESET_DELAY
1831 Some PHY like Intel LXT971A need extra delay after
1832 reset before any MII register access is possible.
1833 For such PHY, set this option to the usec delay
1834 required. (minimum 300usec for LXT971A)
1836 CONFIG_PHY_CMD_DELAY (ppc4xx)
1838 Some PHY like Intel LXT971A need extra delay after
1839 command issued before MII status register can be read
1849 Define a default value for Ethernet address to use
1850 for the respective Ethernet interface, in case this
1851 is not determined automatically.
1856 Define a default value for the IP address to use for
1857 the default Ethernet interface, in case this is not
1858 determined through e.g. bootp.
1859 (Environment variable "ipaddr")
1861 - Server IP address:
1864 Defines a default value for the IP address of a TFTP
1865 server to contact when using the "tftboot" command.
1866 (Environment variable "serverip")
1868 CONFIG_KEEP_SERVERADDR
1870 Keeps the server's MAC address, in the env 'serveraddr'
1871 for passing to bootargs (like Linux's netconsole option)
1873 - Gateway IP address:
1876 Defines a default value for the IP address of the
1877 default router where packets to other networks are
1879 (Environment variable "gatewayip")
1884 Defines a default value for the subnet mask (or
1885 routing prefix) which is used to determine if an IP
1886 address belongs to the local subnet or needs to be
1887 forwarded through a router.
1888 (Environment variable "netmask")
1890 - Multicast TFTP Mode:
1893 Defines whether you want to support multicast TFTP as per
1894 rfc-2090; for example to work with atftp. Lets lots of targets
1895 tftp down the same boot image concurrently. Note: the Ethernet
1896 driver in use must provide a function: mcast() to join/leave a
1899 - BOOTP Recovery Mode:
1900 CONFIG_BOOTP_RANDOM_DELAY
1902 If you have many targets in a network that try to
1903 boot using BOOTP, you may want to avoid that all
1904 systems send out BOOTP requests at precisely the same
1905 moment (which would happen for instance at recovery
1906 from a power failure, when all systems will try to
1907 boot, thus flooding the BOOTP server. Defining
1908 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1909 inserted before sending out BOOTP requests. The
1910 following delays are inserted then:
1912 1st BOOTP request: delay 0 ... 1 sec
1913 2nd BOOTP request: delay 0 ... 2 sec
1914 3rd BOOTP request: delay 0 ... 4 sec
1916 BOOTP requests: delay 0 ... 8 sec
1918 - DHCP Advanced Options:
1919 You can fine tune the DHCP functionality by defining
1920 CONFIG_BOOTP_* symbols:
1922 CONFIG_BOOTP_SUBNETMASK
1923 CONFIG_BOOTP_GATEWAY
1924 CONFIG_BOOTP_HOSTNAME
1925 CONFIG_BOOTP_NISDOMAIN
1926 CONFIG_BOOTP_BOOTPATH
1927 CONFIG_BOOTP_BOOTFILESIZE
1930 CONFIG_BOOTP_SEND_HOSTNAME
1931 CONFIG_BOOTP_NTPSERVER
1932 CONFIG_BOOTP_TIMEOFFSET
1933 CONFIG_BOOTP_VENDOREX
1934 CONFIG_BOOTP_MAY_FAIL
1936 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1937 environment variable, not the BOOTP server.
1939 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1940 after the configured retry count, the call will fail
1941 instead of starting over. This can be used to fail over
1942 to Link-local IP address configuration if the DHCP server
1945 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1946 serverip from a DHCP server, it is possible that more
1947 than one DNS serverip is offered to the client.
1948 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1949 serverip will be stored in the additional environment
1950 variable "dnsip2". The first DNS serverip is always
1951 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1954 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1955 to do a dynamic update of a DNS server. To do this, they
1956 need the hostname of the DHCP requester.
1957 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1958 of the "hostname" environment variable is passed as
1959 option 12 to the DHCP server.
1961 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1963 A 32bit value in microseconds for a delay between
1964 receiving a "DHCP Offer" and sending the "DHCP Request".
1965 This fixes a problem with certain DHCP servers that don't
1966 respond 100% of the time to a "DHCP request". E.g. On an
1967 AT91RM9200 processor running at 180MHz, this delay needed
1968 to be *at least* 15,000 usec before a Windows Server 2003
1969 DHCP server would reply 100% of the time. I recommend at
1970 least 50,000 usec to be safe. The alternative is to hope
1971 that one of the retries will be successful but note that
1972 the DHCP timeout and retry process takes a longer than
1975 - Link-local IP address negotiation:
1976 Negotiate with other link-local clients on the local network
1977 for an address that doesn't require explicit configuration.
1978 This is especially useful if a DHCP server cannot be guaranteed
1979 to exist in all environments that the device must operate.
1981 See doc/README.link-local for more information.
1984 CONFIG_CDP_DEVICE_ID
1986 The device id used in CDP trigger frames.
1988 CONFIG_CDP_DEVICE_ID_PREFIX
1990 A two character string which is prefixed to the MAC address
1995 A printf format string which contains the ascii name of
1996 the port. Normally is set to "eth%d" which sets
1997 eth0 for the first Ethernet, eth1 for the second etc.
1999 CONFIG_CDP_CAPABILITIES
2001 A 32bit integer which indicates the device capabilities;
2002 0x00000010 for a normal host which does not forwards.
2006 An ascii string containing the version of the software.
2010 An ascii string containing the name of the platform.
2014 A 32bit integer sent on the trigger.
2016 CONFIG_CDP_POWER_CONSUMPTION
2018 A 16bit integer containing the power consumption of the
2019 device in .1 of milliwatts.
2021 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2023 A byte containing the id of the VLAN.
2025 - Status LED: CONFIG_STATUS_LED
2027 Several configurations allow to display the current
2028 status using a LED. For instance, the LED will blink
2029 fast while running U-Boot code, stop blinking as
2030 soon as a reply to a BOOTP request was received, and
2031 start blinking slow once the Linux kernel is running
2032 (supported by a status LED driver in the Linux
2033 kernel). Defining CONFIG_STATUS_LED enables this
2039 The status LED can be connected to a GPIO pin.
2040 In such cases, the gpio_led driver can be used as a
2041 status LED backend implementation. Define CONFIG_GPIO_LED
2042 to include the gpio_led driver in the U-Boot binary.
2044 CONFIG_GPIO_LED_INVERTED_TABLE
2045 Some GPIO connected LEDs may have inverted polarity in which
2046 case the GPIO high value corresponds to LED off state and
2047 GPIO low value corresponds to LED on state.
2048 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2049 with a list of GPIO LEDs that have inverted polarity.
2051 - CAN Support: CONFIG_CAN_DRIVER
2053 Defining CONFIG_CAN_DRIVER enables CAN driver support
2054 on those systems that support this (optional)
2055 feature, like the TQM8xxL modules.
2057 - I2C Support: CONFIG_SYS_I2C
2059 This enable the NEW i2c subsystem, and will allow you to use
2060 i2c commands at the u-boot command line (as long as you set
2061 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2062 based realtime clock chips or other i2c devices. See
2063 common/cmd_i2c.c for a description of the command line
2066 ported i2c driver to the new framework:
2067 - drivers/i2c/soft_i2c.c:
2068 - activate first bus with CONFIG_SYS_I2C_SOFT define
2069 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2070 for defining speed and slave address
2071 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2072 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2073 for defining speed and slave address
2074 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2075 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2076 for defining speed and slave address
2077 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2078 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2079 for defining speed and slave address
2081 - drivers/i2c/fsl_i2c.c:
2082 - activate i2c driver with CONFIG_SYS_I2C_FSL
2083 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2084 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2085 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2087 - If your board supports a second fsl i2c bus, define
2088 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2089 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2090 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2093 - drivers/i2c/tegra_i2c.c:
2094 - activate this driver with CONFIG_SYS_I2C_TEGRA
2095 - This driver adds 4 i2c buses with a fix speed from
2096 100000 and the slave addr 0!
2098 - drivers/i2c/ppc4xx_i2c.c
2099 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2100 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2101 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2103 - drivers/i2c/i2c_mxc.c
2104 - activate this driver with CONFIG_SYS_I2C_MXC
2105 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2106 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2107 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2108 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2109 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2110 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2111 If thoses defines are not set, default value is 100000
2112 for speed, and 0 for slave.
2114 - drivers/i2c/rcar_i2c.c:
2115 - activate this driver with CONFIG_SYS_I2C_RCAR
2116 - This driver adds 4 i2c buses
2118 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2119 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2120 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2121 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2122 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2123 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2124 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2125 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2126 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2128 - drivers/i2c/sh_i2c.c:
2129 - activate this driver with CONFIG_SYS_I2C_SH
2130 - This driver adds from 2 to 5 i2c buses
2132 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2133 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2134 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2135 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2136 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2137 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2138 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2139 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2140 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2141 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2142 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2143 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2144 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2146 - drivers/i2c/omap24xx_i2c.c
2147 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2148 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2149 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2150 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2151 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2152 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2153 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2154 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2155 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2156 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2157 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2159 - drivers/i2c/zynq_i2c.c
2160 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2161 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2162 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2164 - drivers/i2c/s3c24x0_i2c.c:
2165 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2166 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2167 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2168 with a fix speed from 100000 and the slave addr 0!
2172 CONFIG_SYS_NUM_I2C_BUSES
2173 Hold the number of i2c busses you want to use. If you
2174 don't use/have i2c muxes on your i2c bus, this
2175 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2178 CONFIG_SYS_I2C_DIRECT_BUS
2179 define this, if you don't use i2c muxes on your hardware.
2180 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2183 CONFIG_SYS_I2C_MAX_HOPS
2184 define how many muxes are maximal consecutively connected
2185 on one i2c bus. If you not use i2c muxes, omit this
2188 CONFIG_SYS_I2C_BUSES
2189 hold a list of busses you want to use, only used if
2190 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2191 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2192 CONFIG_SYS_NUM_I2C_BUSES = 9:
2194 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2195 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2196 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2197 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2198 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2199 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2200 {1, {I2C_NULL_HOP}}, \
2201 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2202 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2206 bus 0 on adapter 0 without a mux
2207 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2208 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2209 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2210 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2211 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2212 bus 6 on adapter 1 without a mux
2213 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2214 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2216 If you do not have i2c muxes on your board, omit this define.
2218 - Legacy I2C Support: CONFIG_HARD_I2C
2220 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2221 provides the following compelling advantages:
2223 - more than one i2c adapter is usable
2224 - approved multibus support
2225 - better i2c mux support
2227 ** Please consider updating your I2C driver now. **
2229 These enable legacy I2C serial bus commands. Defining
2230 CONFIG_HARD_I2C will include the appropriate I2C driver
2231 for the selected CPU.
2233 This will allow you to use i2c commands at the u-boot
2234 command line (as long as you set CONFIG_CMD_I2C in
2235 CONFIG_COMMANDS) and communicate with i2c based realtime
2236 clock chips. See common/cmd_i2c.c for a description of the
2237 command line interface.
2239 CONFIG_HARD_I2C selects a hardware I2C controller.
2241 There are several other quantities that must also be
2242 defined when you define CONFIG_HARD_I2C.
2244 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2245 to be the frequency (in Hz) at which you wish your i2c bus
2246 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2247 the CPU's i2c node address).
2249 Now, the u-boot i2c code for the mpc8xx
2250 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2251 and so its address should therefore be cleared to 0 (See,
2252 eg, MPC823e User's Manual p.16-473). So, set
2253 CONFIG_SYS_I2C_SLAVE to 0.
2255 CONFIG_SYS_I2C_INIT_MPC5XXX
2257 When a board is reset during an i2c bus transfer
2258 chips might think that the current transfer is still
2259 in progress. Reset the slave devices by sending start
2260 commands until the slave device responds.
2262 That's all that's required for CONFIG_HARD_I2C.
2264 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2265 then the following macros need to be defined (examples are
2266 from include/configs/lwmon.h):
2270 (Optional). Any commands necessary to enable the I2C
2271 controller or configure ports.
2273 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2277 (Only for MPC8260 CPU). The I/O port to use (the code
2278 assumes both bits are on the same port). Valid values
2279 are 0..3 for ports A..D.
2283 The code necessary to make the I2C data line active
2284 (driven). If the data line is open collector, this
2287 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2291 The code necessary to make the I2C data line tri-stated
2292 (inactive). If the data line is open collector, this
2295 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2299 Code that returns true if the I2C data line is high,
2302 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2306 If <bit> is true, sets the I2C data line high. If it
2307 is false, it clears it (low).
2309 eg: #define I2C_SDA(bit) \
2310 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2311 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2315 If <bit> is true, sets the I2C clock line high. If it
2316 is false, it clears it (low).
2318 eg: #define I2C_SCL(bit) \
2319 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2320 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2324 This delay is invoked four times per clock cycle so this
2325 controls the rate of data transfer. The data rate thus
2326 is 1 / (I2C_DELAY * 4). Often defined to be something
2329 #define I2C_DELAY udelay(2)
2331 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2333 If your arch supports the generic GPIO framework (asm/gpio.h),
2334 then you may alternatively define the two GPIOs that are to be
2335 used as SCL / SDA. Any of the previous I2C_xxx macros will
2336 have GPIO-based defaults assigned to them as appropriate.
2338 You should define these to the GPIO value as given directly to
2339 the generic GPIO functions.
2341 CONFIG_SYS_I2C_INIT_BOARD
2343 When a board is reset during an i2c bus transfer
2344 chips might think that the current transfer is still
2345 in progress. On some boards it is possible to access
2346 the i2c SCLK line directly, either by using the
2347 processor pin as a GPIO or by having a second pin
2348 connected to the bus. If this option is defined a
2349 custom i2c_init_board() routine in boards/xxx/board.c
2350 is run early in the boot sequence.
2352 CONFIG_SYS_I2C_BOARD_LATE_INIT
2354 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2355 defined a custom i2c_board_late_init() routine in
2356 boards/xxx/board.c is run AFTER the operations in i2c_init()
2357 is completed. This callpoint can be used to unreset i2c bus
2358 using CPU i2c controller register accesses for CPUs whose i2c
2359 controller provide such a method. It is called at the end of
2360 i2c_init() to allow i2c_init operations to setup the i2c bus
2361 controller on the CPU (e.g. setting bus speed & slave address).
2363 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2365 This option enables configuration of bi_iic_fast[] flags
2366 in u-boot bd_info structure based on u-boot environment
2367 variable "i2cfast". (see also i2cfast)
2369 CONFIG_I2C_MULTI_BUS
2371 This option allows the use of multiple I2C buses, each of which
2372 must have a controller. At any point in time, only one bus is
2373 active. To switch to a different bus, use the 'i2c dev' command.
2374 Note that bus numbering is zero-based.
2376 CONFIG_SYS_I2C_NOPROBES
2378 This option specifies a list of I2C devices that will be skipped
2379 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2380 is set, specify a list of bus-device pairs. Otherwise, specify
2381 a 1D array of device addresses
2384 #undef CONFIG_I2C_MULTI_BUS
2385 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2387 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2389 #define CONFIG_I2C_MULTI_BUS
2390 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2392 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2394 CONFIG_SYS_SPD_BUS_NUM
2396 If defined, then this indicates the I2C bus number for DDR SPD.
2397 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2399 CONFIG_SYS_RTC_BUS_NUM
2401 If defined, then this indicates the I2C bus number for the RTC.
2402 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2404 CONFIG_SYS_DTT_BUS_NUM
2406 If defined, then this indicates the I2C bus number for the DTT.
2407 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2409 CONFIG_SYS_I2C_DTT_ADDR:
2411 If defined, specifies the I2C address of the DTT device.
2412 If not defined, then U-Boot uses predefined value for
2413 specified DTT device.
2415 CONFIG_SOFT_I2C_READ_REPEATED_START
2417 defining this will force the i2c_read() function in
2418 the soft_i2c driver to perform an I2C repeated start
2419 between writing the address pointer and reading the
2420 data. If this define is omitted the default behaviour
2421 of doing a stop-start sequence will be used. Most I2C
2422 devices can use either method, but some require one or
2425 - SPI Support: CONFIG_SPI
2427 Enables SPI driver (so far only tested with
2428 SPI EEPROM, also an instance works with Crystal A/D and
2429 D/As on the SACSng board)
2433 Enables the driver for SPI controller on SuperH. Currently
2434 only SH7757 is supported.
2438 Enables extended (16-bit) SPI EEPROM addressing.
2439 (symmetrical to CONFIG_I2C_X)
2443 Enables a software (bit-bang) SPI driver rather than
2444 using hardware support. This is a general purpose
2445 driver that only requires three general I/O port pins
2446 (two outputs, one input) to function. If this is
2447 defined, the board configuration must define several
2448 SPI configuration items (port pins to use, etc). For
2449 an example, see include/configs/sacsng.h.
2453 Enables a hardware SPI driver for general-purpose reads
2454 and writes. As with CONFIG_SOFT_SPI, the board configuration
2455 must define a list of chip-select function pointers.
2456 Currently supported on some MPC8xxx processors. For an
2457 example, see include/configs/mpc8349emds.h.
2461 Enables the driver for the SPI controllers on i.MX and MXC
2462 SoCs. Currently i.MX31/35/51 are supported.
2464 - FPGA Support: CONFIG_FPGA
2466 Enables FPGA subsystem.
2468 CONFIG_FPGA_<vendor>
2470 Enables support for specific chip vendors.
2473 CONFIG_FPGA_<family>
2475 Enables support for FPGA family.
2476 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2480 Specify the number of FPGA devices to support.
2482 CONFIG_SYS_FPGA_PROG_FEEDBACK
2484 Enable printing of hash marks during FPGA configuration.
2486 CONFIG_SYS_FPGA_CHECK_BUSY
2488 Enable checks on FPGA configuration interface busy
2489 status by the configuration function. This option
2490 will require a board or device specific function to
2495 If defined, a function that provides delays in the FPGA
2496 configuration driver.
2498 CONFIG_SYS_FPGA_CHECK_CTRLC
2499 Allow Control-C to interrupt FPGA configuration
2501 CONFIG_SYS_FPGA_CHECK_ERROR
2503 Check for configuration errors during FPGA bitfile
2504 loading. For example, abort during Virtex II
2505 configuration if the INIT_B line goes low (which
2506 indicated a CRC error).
2508 CONFIG_SYS_FPGA_WAIT_INIT
2510 Maximum time to wait for the INIT_B line to deassert
2511 after PROB_B has been deasserted during a Virtex II
2512 FPGA configuration sequence. The default time is 500
2515 CONFIG_SYS_FPGA_WAIT_BUSY
2517 Maximum time to wait for BUSY to deassert during
2518 Virtex II FPGA configuration. The default is 5 ms.
2520 CONFIG_SYS_FPGA_WAIT_CONFIG
2522 Time to wait after FPGA configuration. The default is
2525 - Configuration Management:
2528 If defined, this string will be added to the U-Boot
2529 version information (U_BOOT_VERSION)
2531 - Vendor Parameter Protection:
2533 U-Boot considers the values of the environment
2534 variables "serial#" (Board Serial Number) and
2535 "ethaddr" (Ethernet Address) to be parameters that
2536 are set once by the board vendor / manufacturer, and
2537 protects these variables from casual modification by
2538 the user. Once set, these variables are read-only,
2539 and write or delete attempts are rejected. You can
2540 change this behaviour:
2542 If CONFIG_ENV_OVERWRITE is #defined in your config
2543 file, the write protection for vendor parameters is
2544 completely disabled. Anybody can change or delete
2547 Alternatively, if you #define _both_ CONFIG_ETHADDR
2548 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2549 Ethernet address is installed in the environment,
2550 which can be changed exactly ONCE by the user. [The
2551 serial# is unaffected by this, i. e. it remains
2554 The same can be accomplished in a more flexible way
2555 for any variable by configuring the type of access
2556 to allow for those variables in the ".flags" variable
2557 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2562 Define this variable to enable the reservation of
2563 "protected RAM", i. e. RAM which is not overwritten
2564 by U-Boot. Define CONFIG_PRAM to hold the number of
2565 kB you want to reserve for pRAM. You can overwrite
2566 this default value by defining an environment
2567 variable "pram" to the number of kB you want to
2568 reserve. Note that the board info structure will
2569 still show the full amount of RAM. If pRAM is
2570 reserved, a new environment variable "mem" will
2571 automatically be defined to hold the amount of
2572 remaining RAM in a form that can be passed as boot
2573 argument to Linux, for instance like that:
2575 setenv bootargs ... mem=\${mem}
2578 This way you can tell Linux not to use this memory,
2579 either, which results in a memory region that will
2580 not be affected by reboots.
2582 *WARNING* If your board configuration uses automatic
2583 detection of the RAM size, you must make sure that
2584 this memory test is non-destructive. So far, the
2585 following board configurations are known to be
2588 IVMS8, IVML24, SPD8xx, TQM8xxL,
2589 HERMES, IP860, RPXlite, LWMON,
2592 - Access to physical memory region (> 4GB)
2593 Some basic support is provided for operations on memory not
2594 normally accessible to U-Boot - e.g. some architectures
2595 support access to more than 4GB of memory on 32-bit
2596 machines using physical address extension or similar.
2597 Define CONFIG_PHYSMEM to access this basic support, which
2598 currently only supports clearing the memory.
2603 Define this variable to stop the system in case of a
2604 fatal error, so that you have to reset it manually.
2605 This is probably NOT a good idea for an embedded
2606 system where you want the system to reboot
2607 automatically as fast as possible, but it may be
2608 useful during development since you can try to debug
2609 the conditions that lead to the situation.
2611 CONFIG_NET_RETRY_COUNT
2613 This variable defines the number of retries for
2614 network operations like ARP, RARP, TFTP, or BOOTP
2615 before giving up the operation. If not defined, a
2616 default value of 5 is used.
2620 Timeout waiting for an ARP reply in milliseconds.
2624 Timeout in milliseconds used in NFS protocol.
2625 If you encounter "ERROR: Cannot umount" in nfs command,
2626 try longer timeout such as
2627 #define CONFIG_NFS_TIMEOUT 10000UL
2629 - Command Interpreter:
2630 CONFIG_AUTO_COMPLETE
2632 Enable auto completion of commands using TAB.
2634 Note that this feature has NOT been implemented yet
2635 for the "hush" shell.
2638 CONFIG_SYS_HUSH_PARSER
2640 Define this variable to enable the "hush" shell (from
2641 Busybox) as command line interpreter, thus enabling
2642 powerful command line syntax like
2643 if...then...else...fi conditionals or `&&' and '||'
2644 constructs ("shell scripts").
2646 If undefined, you get the old, much simpler behaviour
2647 with a somewhat smaller memory footprint.
2650 CONFIG_SYS_PROMPT_HUSH_PS2
2652 This defines the secondary prompt string, which is
2653 printed when the command interpreter needs more input
2654 to complete a command. Usually "> ".
2658 In the current implementation, the local variables
2659 space and global environment variables space are
2660 separated. Local variables are those you define by
2661 simply typing `name=value'. To access a local
2662 variable later on, you have write `$name' or
2663 `${name}'; to execute the contents of a variable
2664 directly type `$name' at the command prompt.
2666 Global environment variables are those you use
2667 setenv/printenv to work with. To run a command stored
2668 in such a variable, you need to use the run command,
2669 and you must not use the '$' sign to access them.
2671 To store commands and special characters in a
2672 variable, please use double quotation marks
2673 surrounding the whole text of the variable, instead
2674 of the backslashes before semicolons and special
2677 - Commandline Editing and History:
2678 CONFIG_CMDLINE_EDITING
2680 Enable editing and History functions for interactive
2681 commandline input operations
2683 - Default Environment:
2684 CONFIG_EXTRA_ENV_SETTINGS
2686 Define this to contain any number of null terminated
2687 strings (variable = value pairs) that will be part of
2688 the default environment compiled into the boot image.
2690 For example, place something like this in your
2691 board's config file:
2693 #define CONFIG_EXTRA_ENV_SETTINGS \
2697 Warning: This method is based on knowledge about the
2698 internal format how the environment is stored by the
2699 U-Boot code. This is NOT an official, exported
2700 interface! Although it is unlikely that this format
2701 will change soon, there is no guarantee either.
2702 You better know what you are doing here.
2704 Note: overly (ab)use of the default environment is
2705 discouraged. Make sure to check other ways to preset
2706 the environment like the "source" command or the
2709 CONFIG_ENV_VARS_UBOOT_CONFIG
2711 Define this in order to add variables describing the
2712 U-Boot build configuration to the default environment.
2713 These will be named arch, cpu, board, vendor, and soc.
2715 Enabling this option will cause the following to be defined:
2723 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2725 Define this in order to add variables describing certain
2726 run-time determined information about the hardware to the
2727 environment. These will be named board_name, board_rev.
2729 CONFIG_DELAY_ENVIRONMENT
2731 Normally the environment is loaded when the board is
2732 intialised so that it is available to U-Boot. This inhibits
2733 that so that the environment is not available until
2734 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2735 this is instead controlled by the value of
2736 /config/load-environment.
2738 - DataFlash Support:
2739 CONFIG_HAS_DATAFLASH
2741 Defining this option enables DataFlash features and
2742 allows to read/write in Dataflash via the standard
2745 - Serial Flash support
2748 Defining this option enables SPI flash commands
2749 'sf probe/read/write/erase/update'.
2751 Usage requires an initial 'probe' to define the serial
2752 flash parameters, followed by read/write/erase/update
2755 The following defaults may be provided by the platform
2756 to handle the common case when only a single serial
2757 flash is present on the system.
2759 CONFIG_SF_DEFAULT_BUS Bus identifier
2760 CONFIG_SF_DEFAULT_CS Chip-select
2761 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2762 CONFIG_SF_DEFAULT_SPEED in Hz
2766 Define this option to include a destructive SPI flash
2769 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2771 Define this option to use the Bank addr/Extended addr
2772 support on SPI flashes which has size > 16Mbytes.
2774 CONFIG_SF_DUAL_FLASH Dual flash memories
2776 Define this option to use dual flash support where two flash
2777 memories can be connected with a given cs line.
2778 currently Xilinx Zynq qspi support these type of connections.
2780 - SystemACE Support:
2783 Adding this option adds support for Xilinx SystemACE
2784 chips attached via some sort of local bus. The address
2785 of the chip must also be defined in the
2786 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2788 #define CONFIG_SYSTEMACE
2789 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2791 When SystemACE support is added, the "ace" device type
2792 becomes available to the fat commands, i.e. fatls.
2794 - TFTP Fixed UDP Port:
2797 If this is defined, the environment variable tftpsrcp
2798 is used to supply the TFTP UDP source port value.
2799 If tftpsrcp isn't defined, the normal pseudo-random port
2800 number generator is used.
2802 Also, the environment variable tftpdstp is used to supply
2803 the TFTP UDP destination port value. If tftpdstp isn't
2804 defined, the normal port 69 is used.
2806 The purpose for tftpsrcp is to allow a TFTP server to
2807 blindly start the TFTP transfer using the pre-configured
2808 target IP address and UDP port. This has the effect of
2809 "punching through" the (Windows XP) firewall, allowing
2810 the remainder of the TFTP transfer to proceed normally.
2811 A better solution is to properly configure the firewall,
2812 but sometimes that is not allowed.
2817 This enables a generic 'hash' command which can produce
2818 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2822 Enable the hash verify command (hash -v). This adds to code
2825 CONFIG_SHA1 - support SHA1 hashing
2826 CONFIG_SHA256 - support SHA256 hashing
2828 Note: There is also a sha1sum command, which should perhaps
2829 be deprecated in favour of 'hash sha1'.
2831 - Freescale i.MX specific commands:
2832 CONFIG_CMD_HDMIDETECT
2833 This enables 'hdmidet' command which returns true if an
2834 HDMI monitor is detected. This command is i.MX 6 specific.
2837 This enables the 'bmode' (bootmode) command for forcing
2838 a boot from specific media.
2840 This is useful for forcing the ROM's usb downloader to
2841 activate upon a watchdog reset which is nice when iterating
2842 on U-Boot. Using the reset button or running bmode normal
2843 will set it back to normal. This command currently
2844 supports i.MX53 and i.MX6.
2849 This enables the RSA algorithm used for FIT image verification
2850 in U-Boot. See doc/uImage/signature for more information.
2852 The signing part is build into mkimage regardless of this
2856 - Show boot progress:
2857 CONFIG_SHOW_BOOT_PROGRESS
2859 Defining this option allows to add some board-
2860 specific code (calling a user-provided function
2861 "show_boot_progress(int)") that enables you to show
2862 the system's boot progress on some display (for
2863 example, some LED's) on your board. At the moment,
2864 the following checkpoints are implemented:
2866 - Detailed boot stage timing
2868 Define this option to get detailed timing of each stage
2869 of the boot process.
2871 CONFIG_BOOTSTAGE_USER_COUNT
2872 This is the number of available user bootstage records.
2873 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2874 a new ID will be allocated from this stash. If you exceed
2875 the limit, recording will stop.
2877 CONFIG_BOOTSTAGE_REPORT
2878 Define this to print a report before boot, similar to this:
2880 Timer summary in microseconds:
2883 3,575,678 3,575,678 board_init_f start
2884 3,575,695 17 arch_cpu_init A9
2885 3,575,777 82 arch_cpu_init done
2886 3,659,598 83,821 board_init_r start
2887 3,910,375 250,777 main_loop
2888 29,916,167 26,005,792 bootm_start
2889 30,361,327 445,160 start_kernel
2891 CONFIG_CMD_BOOTSTAGE
2892 Add a 'bootstage' command which supports printing a report
2893 and un/stashing of bootstage data.
2895 CONFIG_BOOTSTAGE_FDT
2896 Stash the bootstage information in the FDT. A root 'bootstage'
2897 node is created with each bootstage id as a child. Each child
2898 has a 'name' property and either 'mark' containing the
2899 mark time in microsecond, or 'accum' containing the
2900 accumulated time for that bootstage id in microseconds.
2905 name = "board_init_f";
2914 Code in the Linux kernel can find this in /proc/devicetree.
2916 Legacy uImage format:
2919 1 common/cmd_bootm.c before attempting to boot an image
2920 -1 common/cmd_bootm.c Image header has bad magic number
2921 2 common/cmd_bootm.c Image header has correct magic number
2922 -2 common/cmd_bootm.c Image header has bad checksum
2923 3 common/cmd_bootm.c Image header has correct checksum
2924 -3 common/cmd_bootm.c Image data has bad checksum
2925 4 common/cmd_bootm.c Image data has correct checksum
2926 -4 common/cmd_bootm.c Image is for unsupported architecture
2927 5 common/cmd_bootm.c Architecture check OK
2928 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2929 6 common/cmd_bootm.c Image Type check OK
2930 -6 common/cmd_bootm.c gunzip uncompression error
2931 -7 common/cmd_bootm.c Unimplemented compression type
2932 7 common/cmd_bootm.c Uncompression OK
2933 8 common/cmd_bootm.c No uncompress/copy overwrite error
2934 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2936 9 common/image.c Start initial ramdisk verification
2937 -10 common/image.c Ramdisk header has bad magic number
2938 -11 common/image.c Ramdisk header has bad checksum
2939 10 common/image.c Ramdisk header is OK
2940 -12 common/image.c Ramdisk data has bad checksum
2941 11 common/image.c Ramdisk data has correct checksum
2942 12 common/image.c Ramdisk verification complete, start loading
2943 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2944 13 common/image.c Start multifile image verification
2945 14 common/image.c No initial ramdisk, no multifile, continue.
2947 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2949 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2950 -31 post/post.c POST test failed, detected by post_output_backlog()
2951 -32 post/post.c POST test failed, detected by post_run_single()
2953 34 common/cmd_doc.c before loading a Image from a DOC device
2954 -35 common/cmd_doc.c Bad usage of "doc" command
2955 35 common/cmd_doc.c correct usage of "doc" command
2956 -36 common/cmd_doc.c No boot device
2957 36 common/cmd_doc.c correct boot device
2958 -37 common/cmd_doc.c Unknown Chip ID on boot device
2959 37 common/cmd_doc.c correct chip ID found, device available
2960 -38 common/cmd_doc.c Read Error on boot device
2961 38 common/cmd_doc.c reading Image header from DOC device OK
2962 -39 common/cmd_doc.c Image header has bad magic number
2963 39 common/cmd_doc.c Image header has correct magic number
2964 -40 common/cmd_doc.c Error reading Image from DOC device
2965 40 common/cmd_doc.c Image header has correct magic number
2966 41 common/cmd_ide.c before loading a Image from a IDE device
2967 -42 common/cmd_ide.c Bad usage of "ide" command
2968 42 common/cmd_ide.c correct usage of "ide" command
2969 -43 common/cmd_ide.c No boot device
2970 43 common/cmd_ide.c boot device found
2971 -44 common/cmd_ide.c Device not available
2972 44 common/cmd_ide.c Device available
2973 -45 common/cmd_ide.c wrong partition selected
2974 45 common/cmd_ide.c partition selected
2975 -46 common/cmd_ide.c Unknown partition table
2976 46 common/cmd_ide.c valid partition table found
2977 -47 common/cmd_ide.c Invalid partition type
2978 47 common/cmd_ide.c correct partition type
2979 -48 common/cmd_ide.c Error reading Image Header on boot device
2980 48 common/cmd_ide.c reading Image Header from IDE device OK
2981 -49 common/cmd_ide.c Image header has bad magic number
2982 49 common/cmd_ide.c Image header has correct magic number
2983 -50 common/cmd_ide.c Image header has bad checksum
2984 50 common/cmd_ide.c Image header has correct checksum
2985 -51 common/cmd_ide.c Error reading Image from IDE device
2986 51 common/cmd_ide.c reading Image from IDE device OK
2987 52 common/cmd_nand.c before loading a Image from a NAND device
2988 -53 common/cmd_nand.c Bad usage of "nand" command
2989 53 common/cmd_nand.c correct usage of "nand" command
2990 -54 common/cmd_nand.c No boot device
2991 54 common/cmd_nand.c boot device found
2992 -55 common/cmd_nand.c Unknown Chip ID on boot device
2993 55 common/cmd_nand.c correct chip ID found, device available
2994 -56 common/cmd_nand.c Error reading Image Header on boot device
2995 56 common/cmd_nand.c reading Image Header from NAND device OK
2996 -57 common/cmd_nand.c Image header has bad magic number
2997 57 common/cmd_nand.c Image header has correct magic number
2998 -58 common/cmd_nand.c Error reading Image from NAND device
2999 58 common/cmd_nand.c reading Image from NAND device OK
3001 -60 common/env_common.c Environment has a bad CRC, using default
3003 64 net/eth.c starting with Ethernet configuration.
3004 -64 net/eth.c no Ethernet found.
3005 65 net/eth.c Ethernet found.
3007 -80 common/cmd_net.c usage wrong
3008 80 common/cmd_net.c before calling NetLoop()
3009 -81 common/cmd_net.c some error in NetLoop() occurred
3010 81 common/cmd_net.c NetLoop() back without error
3011 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3012 82 common/cmd_net.c trying automatic boot
3013 83 common/cmd_net.c running "source" command
3014 -83 common/cmd_net.c some error in automatic boot or "source" command
3015 84 common/cmd_net.c end without errors
3020 100 common/cmd_bootm.c Kernel FIT Image has correct format
3021 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3022 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3023 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3024 102 common/cmd_bootm.c Kernel unit name specified
3025 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3026 103 common/cmd_bootm.c Found configuration node
3027 104 common/cmd_bootm.c Got kernel subimage node offset
3028 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3029 105 common/cmd_bootm.c Kernel subimage hash verification OK
3030 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3031 106 common/cmd_bootm.c Architecture check OK
3032 -106 common/cmd_bootm.c Kernel subimage has wrong type
3033 107 common/cmd_bootm.c Kernel subimage type OK
3034 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3035 108 common/cmd_bootm.c Got kernel subimage data/size
3036 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3037 -109 common/cmd_bootm.c Can't get kernel subimage type
3038 -110 common/cmd_bootm.c Can't get kernel subimage comp
3039 -111 common/cmd_bootm.c Can't get kernel subimage os
3040 -112 common/cmd_bootm.c Can't get kernel subimage load address
3041 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3043 120 common/image.c Start initial ramdisk verification
3044 -120 common/image.c Ramdisk FIT image has incorrect format
3045 121 common/image.c Ramdisk FIT image has correct format
3046 122 common/image.c No ramdisk subimage unit name, using configuration
3047 -122 common/image.c Can't get configuration for ramdisk subimage
3048 123 common/image.c Ramdisk unit name specified
3049 -124 common/image.c Can't get ramdisk subimage node offset
3050 125 common/image.c Got ramdisk subimage node offset
3051 -125 common/image.c Ramdisk subimage hash verification failed
3052 126 common/image.c Ramdisk subimage hash verification OK
3053 -126 common/image.c Ramdisk subimage for unsupported architecture
3054 127 common/image.c Architecture check OK
3055 -127 common/image.c Can't get ramdisk subimage data/size
3056 128 common/image.c Got ramdisk subimage data/size
3057 129 common/image.c Can't get ramdisk load address
3058 -129 common/image.c Got ramdisk load address
3060 -130 common/cmd_doc.c Incorrect FIT image format
3061 131 common/cmd_doc.c FIT image format OK
3063 -140 common/cmd_ide.c Incorrect FIT image format
3064 141 common/cmd_ide.c FIT image format OK
3066 -150 common/cmd_nand.c Incorrect FIT image format
3067 151 common/cmd_nand.c FIT image format OK
3069 - FIT image support:
3071 Enable support for the FIT uImage format.
3073 CONFIG_FIT_BEST_MATCH
3074 When no configuration is explicitly selected, default to the
3075 one whose fdt's compatibility field best matches that of
3076 U-Boot itself. A match is considered "best" if it matches the
3077 most specific compatibility entry of U-Boot's fdt's root node.
3078 The order of entries in the configuration's fdt is ignored.
3080 CONFIG_FIT_SIGNATURE
3081 This option enables signature verification of FIT uImages,
3082 using a hash signed and verified using RSA. See
3083 doc/uImage.FIT/signature.txt for more details.
3085 - Standalone program support:
3086 CONFIG_STANDALONE_LOAD_ADDR
3088 This option defines a board specific value for the
3089 address where standalone program gets loaded, thus
3090 overwriting the architecture dependent default
3093 - Frame Buffer Address:
3096 Define CONFIG_FB_ADDR if you want to use specific
3097 address for frame buffer. This is typically the case
3098 when using a graphics controller has separate video
3099 memory. U-Boot will then place the frame buffer at
3100 the given address instead of dynamically reserving it
3101 in system RAM by calling lcd_setmem(), which grabs
3102 the memory for the frame buffer depending on the
3103 configured panel size.
3105 Please see board_init_f function.
3107 - Automatic software updates via TFTP server
3109 CONFIG_UPDATE_TFTP_CNT_MAX
3110 CONFIG_UPDATE_TFTP_MSEC_MAX
3112 These options enable and control the auto-update feature;
3113 for a more detailed description refer to doc/README.update.
3115 - MTD Support (mtdparts command, UBI support)
3118 Adds the MTD device infrastructure from the Linux kernel.
3119 Needed for mtdparts command support.
3121 CONFIG_MTD_PARTITIONS
3123 Adds the MTD partitioning infrastructure from the Linux
3124 kernel. Needed for UBI support.
3129 Adds commands for interacting with MTD partitions formatted
3130 with the UBI flash translation layer
3132 Requires also defining CONFIG_RBTREE
3134 CONFIG_UBI_SILENCE_MSG
3136 Make the verbose messages from UBI stop printing. This leaves
3137 warnings and errors enabled.
3142 Adds commands for interacting with UBI volumes formatted as
3143 UBIFS. UBIFS is read-only in u-boot.
3145 Requires UBI support as well as CONFIG_LZO
3147 CONFIG_UBIFS_SILENCE_MSG
3149 Make the verbose messages from UBIFS stop printing. This leaves
3150 warnings and errors enabled.
3154 Enable building of SPL globally.
3157 LDSCRIPT for linking the SPL binary.
3159 CONFIG_SPL_MAX_FOOTPRINT
3160 Maximum size in memory allocated to the SPL, BSS included.
3161 When defined, the linker checks that the actual memory
3162 used by SPL from _start to __bss_end does not exceed it.
3163 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3164 must not be both defined at the same time.
3167 Maximum size of the SPL image (text, data, rodata, and
3168 linker lists sections), BSS excluded.
3169 When defined, the linker checks that the actual size does
3172 CONFIG_SPL_TEXT_BASE
3173 TEXT_BASE for linking the SPL binary.
3175 CONFIG_SPL_RELOC_TEXT_BASE
3176 Address to relocate to. If unspecified, this is equal to
3177 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3179 CONFIG_SPL_BSS_START_ADDR
3180 Link address for the BSS within the SPL binary.
3182 CONFIG_SPL_BSS_MAX_SIZE
3183 Maximum size in memory allocated to the SPL BSS.
3184 When defined, the linker checks that the actual memory used
3185 by SPL from __bss_start to __bss_end does not exceed it.
3186 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3187 must not be both defined at the same time.
3190 Adress of the start of the stack SPL will use
3192 CONFIG_SPL_RELOC_STACK
3193 Adress of the start of the stack SPL will use after
3194 relocation. If unspecified, this is equal to
3197 CONFIG_SYS_SPL_MALLOC_START
3198 Starting address of the malloc pool used in SPL.
3200 CONFIG_SYS_SPL_MALLOC_SIZE
3201 The size of the malloc pool used in SPL.
3203 CONFIG_SPL_FRAMEWORK
3204 Enable the SPL framework under common/. This framework
3205 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3206 NAND loading of the Linux Kernel.
3208 CONFIG_SPL_DISPLAY_PRINT
3209 For ARM, enable an optional function to print more information
3210 about the running system.
3212 CONFIG_SPL_INIT_MINIMAL
3213 Arch init code should be built for a very small image
3215 CONFIG_SPL_LIBCOMMON_SUPPORT
3216 Support for common/libcommon.o in SPL binary
3218 CONFIG_SPL_LIBDISK_SUPPORT
3219 Support for disk/libdisk.o in SPL binary
3221 CONFIG_SPL_I2C_SUPPORT
3222 Support for drivers/i2c/libi2c.o in SPL binary
3224 CONFIG_SPL_GPIO_SUPPORT
3225 Support for drivers/gpio/libgpio.o in SPL binary
3227 CONFIG_SPL_MMC_SUPPORT
3228 Support for drivers/mmc/libmmc.o in SPL binary
3230 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3231 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3232 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3233 Address, size and partition on the MMC to load U-Boot from
3234 when the MMC is being used in raw mode.
3236 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3237 Sector to load kernel uImage from when MMC is being
3238 used in raw mode (for Falcon mode)
3240 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3241 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3242 Sector and number of sectors to load kernel argument
3243 parameters from when MMC is being used in raw mode
3246 CONFIG_SPL_FAT_SUPPORT
3247 Support for fs/fat/libfat.o in SPL binary
3249 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3250 Filename to read to load U-Boot when reading from FAT
3252 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3253 Filename to read to load kernel uImage when reading
3254 from FAT (for Falcon mode)
3256 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3257 Filename to read to load kernel argument parameters
3258 when reading from FAT (for Falcon mode)
3260 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3261 Set this for NAND SPL on PPC mpc83xx targets, so that
3262 start.S waits for the rest of the SPL to load before
3263 continuing (the hardware starts execution after just
3264 loading the first page rather than the full 4K).
3266 CONFIG_SPL_NAND_BASE
3267 Include nand_base.c in the SPL. Requires
3268 CONFIG_SPL_NAND_DRIVERS.
3270 CONFIG_SPL_NAND_DRIVERS
3271 SPL uses normal NAND drivers, not minimal drivers.
3274 Include standard software ECC in the SPL
3276 CONFIG_SPL_NAND_SIMPLE
3277 Support for NAND boot using simple NAND drivers that
3278 expose the cmd_ctrl() interface.
3280 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3281 Set for the SPL on PPC mpc8xxx targets, support for
3282 drivers/ddr/fsl/libddr.o in SPL binary.
3284 CONFIG_SPL_COMMON_INIT_DDR
3285 Set for common ddr init with serial presence detect in
3288 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3289 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3290 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3291 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3292 CONFIG_SYS_NAND_ECCBYTES
3293 Defines the size and behavior of the NAND that SPL uses
3296 CONFIG_SPL_NAND_BOOT
3297 Add support NAND boot
3299 CONFIG_SYS_NAND_U_BOOT_OFFS
3300 Location in NAND to read U-Boot from
3302 CONFIG_SYS_NAND_U_BOOT_DST
3303 Location in memory to load U-Boot to
3305 CONFIG_SYS_NAND_U_BOOT_SIZE
3306 Size of image to load
3308 CONFIG_SYS_NAND_U_BOOT_START
3309 Entry point in loaded image to jump to
3311 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3312 Define this if you need to first read the OOB and then the
3313 data. This is used for example on davinci plattforms.
3315 CONFIG_SPL_OMAP3_ID_NAND
3316 Support for an OMAP3-specific set of functions to return the
3317 ID and MFR of the first attached NAND chip, if present.
3319 CONFIG_SPL_SERIAL_SUPPORT
3320 Support for drivers/serial/libserial.o in SPL binary
3322 CONFIG_SPL_SPI_FLASH_SUPPORT
3323 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3325 CONFIG_SPL_SPI_SUPPORT
3326 Support for drivers/spi/libspi.o in SPL binary
3328 CONFIG_SPL_RAM_DEVICE
3329 Support for running image already present in ram, in SPL binary
3331 CONFIG_SPL_LIBGENERIC_SUPPORT
3332 Support for lib/libgeneric.o in SPL binary
3334 CONFIG_SPL_ENV_SUPPORT
3335 Support for the environment operating in SPL binary
3337 CONFIG_SPL_NET_SUPPORT
3338 Support for the net/libnet.o in SPL binary.
3339 It conflicts with SPL env from storage medium specified by
3340 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3343 Image offset to which the SPL should be padded before appending
3344 the SPL payload. By default, this is defined as
3345 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3346 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3347 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3350 Final target image containing SPL and payload. Some SPLs
3351 use an arch-specific makefile fragment instead, for
3352 example if more than one image needs to be produced.
3354 CONFIG_FIT_SPL_PRINT
3355 Printing information about a FIT image adds quite a bit of
3356 code to SPL. So this is normally disabled in SPL. Use this
3357 option to re-enable it. This will affect the output of the
3358 bootm command when booting a FIT image.
3362 Enable building of TPL globally.
3365 Image offset to which the TPL should be padded before appending
3366 the TPL payload. By default, this is defined as
3367 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3368 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3369 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3374 [so far only for SMDK2400 boards]
3376 - Modem support enable:
3377 CONFIG_MODEM_SUPPORT
3379 - RTS/CTS Flow control enable:
3382 - Modem debug support:
3383 CONFIG_MODEM_SUPPORT_DEBUG
3385 Enables debugging stuff (char screen[1024], dbg())
3386 for modem support. Useful only with BDI2000.
3388 - Interrupt support (PPC):
3390 There are common interrupt_init() and timer_interrupt()
3391 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3392 for CPU specific initialization. interrupt_init_cpu()
3393 should set decrementer_count to appropriate value. If
3394 CPU resets decrementer automatically after interrupt
3395 (ppc4xx) it should set decrementer_count to zero.
3396 timer_interrupt() calls timer_interrupt_cpu() for CPU
3397 specific handling. If board has watchdog / status_led
3398 / other_activity_monitor it works automatically from
3399 general timer_interrupt().
3403 In the target system modem support is enabled when a
3404 specific key (key combination) is pressed during
3405 power-on. Otherwise U-Boot will boot normally
3406 (autoboot). The key_pressed() function is called from
3407 board_init(). Currently key_pressed() is a dummy
3408 function, returning 1 and thus enabling modem
3411 If there are no modem init strings in the
3412 environment, U-Boot proceed to autoboot; the
3413 previous output (banner, info printfs) will be
3416 See also: doc/README.Modem
3418 Board initialization settings:
3419 ------------------------------
3421 During Initialization u-boot calls a number of board specific functions
3422 to allow the preparation of board specific prerequisites, e.g. pin setup
3423 before drivers are initialized. To enable these callbacks the
3424 following configuration macros have to be defined. Currently this is
3425 architecture specific, so please check arch/your_architecture/lib/board.c
3426 typically in board_init_f() and board_init_r().
3428 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3429 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3430 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3431 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3433 Configuration Settings:
3434 -----------------------
3436 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3437 undefine this when you're short of memory.
3439 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3440 width of the commands listed in the 'help' command output.
3442 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3443 prompt for user input.
3445 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3447 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3449 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3451 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3452 the application (usually a Linux kernel) when it is
3455 - CONFIG_SYS_BAUDRATE_TABLE:
3456 List of legal baudrate settings for this board.
3458 - CONFIG_SYS_CONSOLE_INFO_QUIET
3459 Suppress display of console information at boot.
3461 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3462 If the board specific function
3463 extern int overwrite_console (void);
3464 returns 1, the stdin, stderr and stdout are switched to the
3465 serial port, else the settings in the environment are used.
3467 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3468 Enable the call to overwrite_console().
3470 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3471 Enable overwrite of previous console environment settings.
3473 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3474 Begin and End addresses of the area used by the
3477 - CONFIG_SYS_ALT_MEMTEST:
3478 Enable an alternate, more extensive memory test.
3480 - CONFIG_SYS_MEMTEST_SCRATCH:
3481 Scratch address used by the alternate memory test
3482 You only need to set this if address zero isn't writeable
3484 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3485 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3486 this specified memory area will get subtracted from the top
3487 (end) of RAM and won't get "touched" at all by U-Boot. By
3488 fixing up gd->ram_size the Linux kernel should gets passed
3489 the now "corrected" memory size and won't touch it either.
3490 This should work for arch/ppc and arch/powerpc. Only Linux
3491 board ports in arch/powerpc with bootwrapper support that
3492 recalculate the memory size from the SDRAM controller setup
3493 will have to get fixed in Linux additionally.
3495 This option can be used as a workaround for the 440EPx/GRx
3496 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3499 WARNING: Please make sure that this value is a multiple of
3500 the Linux page size (normally 4k). If this is not the case,
3501 then the end address of the Linux memory will be located at a
3502 non page size aligned address and this could cause major
3505 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3506 Enable temporary baudrate change while serial download
3508 - CONFIG_SYS_SDRAM_BASE:
3509 Physical start address of SDRAM. _Must_ be 0 here.
3511 - CONFIG_SYS_MBIO_BASE:
3512 Physical start address of Motherboard I/O (if using a
3515 - CONFIG_SYS_FLASH_BASE:
3516 Physical start address of Flash memory.
3518 - CONFIG_SYS_MONITOR_BASE:
3519 Physical start address of boot monitor code (set by
3520 make config files to be same as the text base address
3521 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3522 CONFIG_SYS_FLASH_BASE when booting from flash.
3524 - CONFIG_SYS_MONITOR_LEN:
3525 Size of memory reserved for monitor code, used to
3526 determine _at_compile_time_ (!) if the environment is
3527 embedded within the U-Boot image, or in a separate
3530 - CONFIG_SYS_MALLOC_LEN:
3531 Size of DRAM reserved for malloc() use.
3533 - CONFIG_SYS_BOOTM_LEN:
3534 Normally compressed uImages are limited to an
3535 uncompressed size of 8 MBytes. If this is not enough,
3536 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3537 to adjust this setting to your needs.
3539 - CONFIG_SYS_BOOTMAPSZ:
3540 Maximum size of memory mapped by the startup code of
3541 the Linux kernel; all data that must be processed by
3542 the Linux kernel (bd_info, boot arguments, FDT blob if
3543 used) must be put below this limit, unless "bootm_low"
3544 environment variable is defined and non-zero. In such case
3545 all data for the Linux kernel must be between "bootm_low"
3546 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3547 variable "bootm_mapsize" will override the value of
3548 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3549 then the value in "bootm_size" will be used instead.
3551 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3552 Enable initrd_high functionality. If defined then the
3553 initrd_high feature is enabled and the bootm ramdisk subcommand
3556 - CONFIG_SYS_BOOT_GET_CMDLINE:
3557 Enables allocating and saving kernel cmdline in space between
3558 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3560 - CONFIG_SYS_BOOT_GET_KBD:
3561 Enables allocating and saving a kernel copy of the bd_info in
3562 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3564 - CONFIG_SYS_MAX_FLASH_BANKS:
3565 Max number of Flash memory banks
3567 - CONFIG_SYS_MAX_FLASH_SECT:
3568 Max number of sectors on a Flash chip
3570 - CONFIG_SYS_FLASH_ERASE_TOUT:
3571 Timeout for Flash erase operations (in ms)
3573 - CONFIG_SYS_FLASH_WRITE_TOUT:
3574 Timeout for Flash write operations (in ms)
3576 - CONFIG_SYS_FLASH_LOCK_TOUT
3577 Timeout for Flash set sector lock bit operation (in ms)
3579 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3580 Timeout for Flash clear lock bits operation (in ms)
3582 - CONFIG_SYS_FLASH_PROTECTION
3583 If defined, hardware flash sectors protection is used
3584 instead of U-Boot software protection.
3586 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3588 Enable TFTP transfers directly to flash memory;
3589 without this option such a download has to be
3590 performed in two steps: (1) download to RAM, and (2)
3591 copy from RAM to flash.
3593 The two-step approach is usually more reliable, since
3594 you can check if the download worked before you erase
3595 the flash, but in some situations (when system RAM is
3596 too limited to allow for a temporary copy of the
3597 downloaded image) this option may be very useful.
3599 - CONFIG_SYS_FLASH_CFI:
3600 Define if the flash driver uses extra elements in the
3601 common flash structure for storing flash geometry.
3603 - CONFIG_FLASH_CFI_DRIVER
3604 This option also enables the building of the cfi_flash driver
3605 in the drivers directory
3607 - CONFIG_FLASH_CFI_MTD
3608 This option enables the building of the cfi_mtd driver
3609 in the drivers directory. The driver exports CFI flash
3612 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3613 Use buffered writes to flash.
3615 - CONFIG_FLASH_SPANSION_S29WS_N
3616 s29ws-n MirrorBit flash has non-standard addresses for buffered
3619 - CONFIG_SYS_FLASH_QUIET_TEST
3620 If this option is defined, the common CFI flash doesn't
3621 print it's warning upon not recognized FLASH banks. This
3622 is useful, if some of the configured banks are only
3623 optionally available.
3625 - CONFIG_FLASH_SHOW_PROGRESS
3626 If defined (must be an integer), print out countdown
3627 digits and dots. Recommended value: 45 (9..1) for 80
3628 column displays, 15 (3..1) for 40 column displays.
3630 - CONFIG_FLASH_VERIFY
3631 If defined, the content of the flash (destination) is compared
3632 against the source after the write operation. An error message
3633 will be printed when the contents are not identical.
3634 Please note that this option is useless in nearly all cases,
3635 since such flash programming errors usually are detected earlier
3636 while unprotecting/erasing/programming. Please only enable
3637 this option if you really know what you are doing.
3639 - CONFIG_SYS_RX_ETH_BUFFER:
3640 Defines the number of Ethernet receive buffers. On some
3641 Ethernet controllers it is recommended to set this value
3642 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3643 buffers can be full shortly after enabling the interface
3644 on high Ethernet traffic.
3645 Defaults to 4 if not defined.
3647 - CONFIG_ENV_MAX_ENTRIES
3649 Maximum number of entries in the hash table that is used
3650 internally to store the environment settings. The default
3651 setting is supposed to be generous and should work in most
3652 cases. This setting can be used to tune behaviour; see
3653 lib/hashtable.c for details.
3655 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3656 - CONFIG_ENV_FLAGS_LIST_STATIC
3657 Enable validation of the values given to environment variables when
3658 calling env set. Variables can be restricted to only decimal,
3659 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3660 the variables can also be restricted to IP address or MAC address.
3662 The format of the list is:
3663 type_attribute = [s|d|x|b|i|m]
3664 access_atribute = [a|r|o|c]
3665 attributes = type_attribute[access_atribute]
3666 entry = variable_name[:attributes]
3669 The type attributes are:
3670 s - String (default)
3673 b - Boolean ([1yYtT|0nNfF])
3677 The access attributes are:
3683 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3684 Define this to a list (string) to define the ".flags"
3685 envirnoment variable in the default or embedded environment.
3687 - CONFIG_ENV_FLAGS_LIST_STATIC
3688 Define this to a list (string) to define validation that
3689 should be done if an entry is not found in the ".flags"
3690 environment variable. To override a setting in the static
3691 list, simply add an entry for the same variable name to the
3694 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3695 If defined, don't allow the -f switch to env set override variable
3698 - CONFIG_SYS_GENERIC_BOARD
3699 This selects the architecture-generic board system instead of the
3700 architecture-specific board files. It is intended to move boards
3701 to this new framework over time. Defining this will disable the
3702 arch/foo/lib/board.c file and use common/board_f.c and
3703 common/board_r.c instead. To use this option your architecture
3704 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3705 its config.mk file). If you find problems enabling this option on
3706 your board please report the problem and send patches!
3708 - CONFIG_SYS_SYM_OFFSETS
3709 This is set by architectures that use offsets for link symbols
3710 instead of absolute values. So bss_start is obtained using an
3711 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3712 directly. You should not need to touch this setting.
3714 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3715 This is set by OMAP boards for the max time that reset should
3716 be asserted. See doc/README.omap-reset-time for details on how
3717 the value can be calulated on a given board.
3719 The following definitions that deal with the placement and management
3720 of environment data (variable area); in general, we support the
3721 following configurations:
3723 - CONFIG_BUILD_ENVCRC:
3725 Builds up envcrc with the target environment so that external utils
3726 may easily extract it and embed it in final U-Boot images.
3728 - CONFIG_ENV_IS_IN_FLASH:
3730 Define this if the environment is in flash memory.
3732 a) The environment occupies one whole flash sector, which is
3733 "embedded" in the text segment with the U-Boot code. This
3734 happens usually with "bottom boot sector" or "top boot
3735 sector" type flash chips, which have several smaller
3736 sectors at the start or the end. For instance, such a
3737 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3738 such a case you would place the environment in one of the
3739 4 kB sectors - with U-Boot code before and after it. With
3740 "top boot sector" type flash chips, you would put the
3741 environment in one of the last sectors, leaving a gap
3742 between U-Boot and the environment.
3744 - CONFIG_ENV_OFFSET:
3746 Offset of environment data (variable area) to the
3747 beginning of flash memory; for instance, with bottom boot
3748 type flash chips the second sector can be used: the offset
3749 for this sector is given here.
3751 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3755 This is just another way to specify the start address of
3756 the flash sector containing the environment (instead of
3759 - CONFIG_ENV_SECT_SIZE:
3761 Size of the sector containing the environment.
3764 b) Sometimes flash chips have few, equal sized, BIG sectors.
3765 In such a case you don't want to spend a whole sector for
3770 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3771 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3772 of this flash sector for the environment. This saves
3773 memory for the RAM copy of the environment.
3775 It may also save flash memory if you decide to use this
3776 when your environment is "embedded" within U-Boot code,
3777 since then the remainder of the flash sector could be used
3778 for U-Boot code. It should be pointed out that this is
3779 STRONGLY DISCOURAGED from a robustness point of view:
3780 updating the environment in flash makes it always
3781 necessary to erase the WHOLE sector. If something goes
3782 wrong before the contents has been restored from a copy in
3783 RAM, your target system will be dead.
3785 - CONFIG_ENV_ADDR_REDUND
3786 CONFIG_ENV_SIZE_REDUND
3788 These settings describe a second storage area used to hold
3789 a redundant copy of the environment data, so that there is
3790 a valid backup copy in case there is a power failure during
3791 a "saveenv" operation.
3793 BE CAREFUL! Any changes to the flash layout, and some changes to the
3794 source code will make it necessary to adapt <board>/u-boot.lds*
3798 - CONFIG_ENV_IS_IN_NVRAM:
3800 Define this if you have some non-volatile memory device
3801 (NVRAM, battery buffered SRAM) which you want to use for the
3807 These two #defines are used to determine the memory area you
3808 want to use for environment. It is assumed that this memory
3809 can just be read and written to, without any special
3812 BE CAREFUL! The first access to the environment happens quite early
3813 in U-Boot initalization (when we try to get the setting of for the
3814 console baudrate). You *MUST* have mapped your NVRAM area then, or
3817 Please note that even with NVRAM we still use a copy of the
3818 environment in RAM: we could work on NVRAM directly, but we want to
3819 keep settings there always unmodified except somebody uses "saveenv"
3820 to save the current settings.
3823 - CONFIG_ENV_IS_IN_EEPROM:
3825 Use this if you have an EEPROM or similar serial access
3826 device and a driver for it.
3828 - CONFIG_ENV_OFFSET:
3831 These two #defines specify the offset and size of the
3832 environment area within the total memory of your EEPROM.
3834 - CONFIG_SYS_I2C_EEPROM_ADDR:
3835 If defined, specified the chip address of the EEPROM device.
3836 The default address is zero.
3838 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3839 If defined, the number of bits used to address bytes in a
3840 single page in the EEPROM device. A 64 byte page, for example
3841 would require six bits.
3843 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3844 If defined, the number of milliseconds to delay between
3845 page writes. The default is zero milliseconds.
3847 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3848 The length in bytes of the EEPROM memory array address. Note
3849 that this is NOT the chip address length!
3851 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3852 EEPROM chips that implement "address overflow" are ones
3853 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3854 address and the extra bits end up in the "chip address" bit
3855 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3858 Note that we consider the length of the address field to
3859 still be one byte because the extra address bits are hidden
3860 in the chip address.
3862 - CONFIG_SYS_EEPROM_SIZE:
3863 The size in bytes of the EEPROM device.
3865 - CONFIG_ENV_EEPROM_IS_ON_I2C
3866 define this, if you have I2C and SPI activated, and your
3867 EEPROM, which holds the environment, is on the I2C bus.
3869 - CONFIG_I2C_ENV_EEPROM_BUS
3870 if you have an Environment on an EEPROM reached over
3871 I2C muxes, you can define here, how to reach this
3872 EEPROM. For example:
3874 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3876 EEPROM which holds the environment, is reached over
3877 a pca9547 i2c mux with address 0x70, channel 3.
3879 - CONFIG_ENV_IS_IN_DATAFLASH:
3881 Define this if you have a DataFlash memory device which you
3882 want to use for the environment.
3884 - CONFIG_ENV_OFFSET:
3888 These three #defines specify the offset and size of the
3889 environment area within the total memory of your DataFlash placed
3890 at the specified address.
3892 - CONFIG_ENV_IS_IN_REMOTE:
3894 Define this if you have a remote memory space which you
3895 want to use for the local device's environment.
3900 These two #defines specify the address and size of the
3901 environment area within the remote memory space. The
3902 local device can get the environment from remote memory
3903 space by SRIO or PCIE links.
3905 BE CAREFUL! For some special cases, the local device can not use
3906 "saveenv" command. For example, the local device will get the
3907 environment stored in a remote NOR flash by SRIO or PCIE link,
3908 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3910 - CONFIG_ENV_IS_IN_NAND:
3912 Define this if you have a NAND device which you want to use
3913 for the environment.
3915 - CONFIG_ENV_OFFSET:
3918 These two #defines specify the offset and size of the environment
3919 area within the first NAND device. CONFIG_ENV_OFFSET must be
3920 aligned to an erase block boundary.
3922 - CONFIG_ENV_OFFSET_REDUND (optional):
3924 This setting describes a second storage area of CONFIG_ENV_SIZE
3925 size used to hold a redundant copy of the environment data, so
3926 that there is a valid backup copy in case there is a power failure
3927 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3928 aligned to an erase block boundary.
3930 - CONFIG_ENV_RANGE (optional):
3932 Specifies the length of the region in which the environment
3933 can be written. This should be a multiple of the NAND device's
3934 block size. Specifying a range with more erase blocks than
3935 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3936 the range to be avoided.
3938 - CONFIG_ENV_OFFSET_OOB (optional):
3940 Enables support for dynamically retrieving the offset of the
3941 environment from block zero's out-of-band data. The
3942 "nand env.oob" command can be used to record this offset.
3943 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3944 using CONFIG_ENV_OFFSET_OOB.
3946 - CONFIG_NAND_ENV_DST
3948 Defines address in RAM to which the nand_spl code should copy the
3949 environment. If redundant environment is used, it will be copied to
3950 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3952 - CONFIG_ENV_IS_IN_UBI:
3954 Define this if you have an UBI volume that you want to use for the
3955 environment. This has the benefit of wear-leveling the environment
3956 accesses, which is important on NAND.
3958 - CONFIG_ENV_UBI_PART:
3960 Define this to a string that is the mtd partition containing the UBI.
3962 - CONFIG_ENV_UBI_VOLUME:
3964 Define this to the name of the volume that you want to store the
3967 - CONFIG_ENV_UBI_VOLUME_REDUND:
3969 Define this to the name of another volume to store a second copy of
3970 the environment in. This will enable redundant environments in UBI.
3971 It is assumed that both volumes are in the same MTD partition.
3973 - CONFIG_UBI_SILENCE_MSG
3974 - CONFIG_UBIFS_SILENCE_MSG
3976 You will probably want to define these to avoid a really noisy system
3977 when storing the env in UBI.
3979 - CONFIG_ENV_IS_IN_MMC:
3981 Define this if you have an MMC device which you want to use for the
3984 - CONFIG_SYS_MMC_ENV_DEV:
3986 Specifies which MMC device the environment is stored in.
3988 - CONFIG_SYS_MMC_ENV_PART (optional):
3990 Specifies which MMC partition the environment is stored in. If not
3991 set, defaults to partition 0, the user area. Common values might be
3992 1 (first MMC boot partition), 2 (second MMC boot partition).
3994 - CONFIG_ENV_OFFSET:
3997 These two #defines specify the offset and size of the environment
3998 area within the specified MMC device.
4000 If offset is positive (the usual case), it is treated as relative to
4001 the start of the MMC partition. If offset is negative, it is treated
4002 as relative to the end of the MMC partition. This can be useful if
4003 your board may be fitted with different MMC devices, which have
4004 different sizes for the MMC partitions, and you always want the
4005 environment placed at the very end of the partition, to leave the
4006 maximum possible space before it, to store other data.
4008 These two values are in units of bytes, but must be aligned to an
4009 MMC sector boundary.
4011 - CONFIG_ENV_OFFSET_REDUND (optional):
4013 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4014 hold a redundant copy of the environment data. This provides a
4015 valid backup copy in case the other copy is corrupted, e.g. due
4016 to a power failure during a "saveenv" operation.
4018 This value may also be positive or negative; this is handled in the
4019 same way as CONFIG_ENV_OFFSET.
4021 This value is also in units of bytes, but must also be aligned to
4022 an MMC sector boundary.
4024 - CONFIG_ENV_SIZE_REDUND (optional):
4026 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4027 set. If this value is set, it must be set to the same value as
4030 - CONFIG_SYS_SPI_INIT_OFFSET
4032 Defines offset to the initial SPI buffer area in DPRAM. The
4033 area is used at an early stage (ROM part) if the environment
4034 is configured to reside in the SPI EEPROM: We need a 520 byte
4035 scratch DPRAM area. It is used between the two initialization
4036 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4037 to be a good choice since it makes it far enough from the
4038 start of the data area as well as from the stack pointer.
4040 Please note that the environment is read-only until the monitor
4041 has been relocated to RAM and a RAM copy of the environment has been
4042 created; also, when using EEPROM you will have to use getenv_f()
4043 until then to read environment variables.
4045 The environment is protected by a CRC32 checksum. Before the monitor
4046 is relocated into RAM, as a result of a bad CRC you will be working
4047 with the compiled-in default environment - *silently*!!! [This is
4048 necessary, because the first environment variable we need is the
4049 "baudrate" setting for the console - if we have a bad CRC, we don't
4050 have any device yet where we could complain.]
4052 Note: once the monitor has been relocated, then it will complain if
4053 the default environment is used; a new CRC is computed as soon as you
4054 use the "saveenv" command to store a valid environment.
4056 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4057 Echo the inverted Ethernet link state to the fault LED.
4059 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4060 also needs to be defined.
4062 - CONFIG_SYS_FAULT_MII_ADDR:
4063 MII address of the PHY to check for the Ethernet link state.
4065 - CONFIG_NS16550_MIN_FUNCTIONS:
4066 Define this if you desire to only have use of the NS16550_init
4067 and NS16550_putc functions for the serial driver located at
4068 drivers/serial/ns16550.c. This option is useful for saving
4069 space for already greatly restricted images, including but not
4070 limited to NAND_SPL configurations.
4072 - CONFIG_DISPLAY_BOARDINFO
4073 Display information about the board that U-Boot is running on
4074 when U-Boot starts up. The board function checkboard() is called
4077 - CONFIG_DISPLAY_BOARDINFO_LATE
4078 Similar to the previous option, but display this information
4079 later, once stdio is running and output goes to the LCD, if
4082 Low Level (hardware related) configuration options:
4083 ---------------------------------------------------
4085 - CONFIG_SYS_CACHELINE_SIZE:
4086 Cache Line Size of the CPU.
4088 - CONFIG_SYS_DEFAULT_IMMR:
4089 Default address of the IMMR after system reset.
4091 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4092 and RPXsuper) to be able to adjust the position of
4093 the IMMR register after a reset.
4095 - CONFIG_SYS_CCSRBAR_DEFAULT:
4096 Default (power-on reset) physical address of CCSR on Freescale
4099 - CONFIG_SYS_CCSRBAR:
4100 Virtual address of CCSR. On a 32-bit build, this is typically
4101 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4103 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4104 for cross-platform code that uses that macro instead.
4106 - CONFIG_SYS_CCSRBAR_PHYS:
4107 Physical address of CCSR. CCSR can be relocated to a new
4108 physical address, if desired. In this case, this macro should
4109 be set to that address. Otherwise, it should be set to the
4110 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4111 is typically relocated on 36-bit builds. It is recommended
4112 that this macro be defined via the _HIGH and _LOW macros:
4114 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4115 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4117 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4118 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4119 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4120 used in assembly code, so it must not contain typecasts or
4121 integer size suffixes (e.g. "ULL").
4123 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4124 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4125 used in assembly code, so it must not contain typecasts or
4126 integer size suffixes (e.g. "ULL").
4128 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4129 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4130 forced to a value that ensures that CCSR is not relocated.
4132 - Floppy Disk Support:
4133 CONFIG_SYS_FDC_DRIVE_NUMBER
4135 the default drive number (default value 0)
4137 CONFIG_SYS_ISA_IO_STRIDE
4139 defines the spacing between FDC chipset registers
4142 CONFIG_SYS_ISA_IO_OFFSET
4144 defines the offset of register from address. It
4145 depends on which part of the data bus is connected to
4146 the FDC chipset. (default value 0)
4148 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4149 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4152 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4153 fdc_hw_init() is called at the beginning of the FDC
4154 setup. fdc_hw_init() must be provided by the board
4155 source code. It is used to make hardware dependant
4159 Most IDE controllers were designed to be connected with PCI
4160 interface. Only few of them were designed for AHB interface.
4161 When software is doing ATA command and data transfer to
4162 IDE devices through IDE-AHB controller, some additional
4163 registers accessing to these kind of IDE-AHB controller
4166 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4167 DO NOT CHANGE unless you know exactly what you're
4168 doing! (11-4) [MPC8xx/82xx systems only]
4170 - CONFIG_SYS_INIT_RAM_ADDR:
4172 Start address of memory area that can be used for
4173 initial data and stack; please note that this must be
4174 writable memory that is working WITHOUT special
4175 initialization, i. e. you CANNOT use normal RAM which
4176 will become available only after programming the
4177 memory controller and running certain initialization
4180 U-Boot uses the following memory types:
4181 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4182 - MPC824X: data cache
4183 - PPC4xx: data cache
4185 - CONFIG_SYS_GBL_DATA_OFFSET:
4187 Offset of the initial data structure in the memory
4188 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4189 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4190 data is located at the end of the available space
4191 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4192 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4193 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4194 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4197 On the MPC824X (or other systems that use the data
4198 cache for initial memory) the address chosen for
4199 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4200 point to an otherwise UNUSED address space between
4201 the top of RAM and the start of the PCI space.
4203 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4205 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4207 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4209 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4211 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4213 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4215 - CONFIG_SYS_OR_TIMING_SDRAM:
4218 - CONFIG_SYS_MAMR_PTA:
4219 periodic timer for refresh
4221 - CONFIG_SYS_DER: Debug Event Register (37-47)
4223 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4224 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4225 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4226 CONFIG_SYS_BR1_PRELIM:
4227 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4229 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4230 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4231 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4232 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4234 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4235 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4236 Machine Mode Register and Memory Periodic Timer
4237 Prescaler definitions (SDRAM timing)
4239 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4240 enable I2C microcode relocation patch (MPC8xx);
4241 define relocation offset in DPRAM [DSP2]
4243 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4244 enable SMC microcode relocation patch (MPC8xx);
4245 define relocation offset in DPRAM [SMC1]
4247 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4248 enable SPI microcode relocation patch (MPC8xx);
4249 define relocation offset in DPRAM [SCC4]
4251 - CONFIG_SYS_USE_OSCCLK:
4252 Use OSCM clock mode on MBX8xx board. Be careful,
4253 wrong setting might damage your board. Read
4254 doc/README.MBX before setting this variable!
4256 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4257 Offset of the bootmode word in DPRAM used by post
4258 (Power On Self Tests). This definition overrides
4259 #define'd default value in commproc.h resp.
4262 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4263 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4264 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4265 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4266 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4267 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4268 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4269 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4270 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4272 - CONFIG_PCI_DISABLE_PCIE:
4273 Disable PCI-Express on systems where it is supported but not
4276 - CONFIG_PCI_ENUM_ONLY
4277 Only scan through and get the devices on the busses.
4278 Don't do any setup work, presumably because someone or
4279 something has already done it, and we don't need to do it
4280 a second time. Useful for platforms that are pre-booted
4281 by coreboot or similar.
4283 - CONFIG_PCI_INDIRECT_BRIDGE:
4284 Enable support for indirect PCI bridges.
4287 Chip has SRIO or not
4290 Board has SRIO 1 port available
4293 Board has SRIO 2 port available
4295 - CONFIG_SRIO_PCIE_BOOT_MASTER
4296 Board can support master function for Boot from SRIO and PCIE
4298 - CONFIG_SYS_SRIOn_MEM_VIRT:
4299 Virtual Address of SRIO port 'n' memory region
4301 - CONFIG_SYS_SRIOn_MEM_PHYS:
4302 Physical Address of SRIO port 'n' memory region
4304 - CONFIG_SYS_SRIOn_MEM_SIZE:
4305 Size of SRIO port 'n' memory region
4307 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4308 Defined to tell the NAND controller that the NAND chip is using
4310 Not all NAND drivers use this symbol.
4311 Example of drivers that use it:
4312 - drivers/mtd/nand/ndfc.c
4313 - drivers/mtd/nand/mxc_nand.c
4315 - CONFIG_SYS_NDFC_EBC0_CFG
4316 Sets the EBC0_CFG register for the NDFC. If not defined
4317 a default value will be used.
4320 Get DDR timing information from an I2C EEPROM. Common
4321 with pluggable memory modules such as SODIMMs
4324 I2C address of the SPD EEPROM
4326 - CONFIG_SYS_SPD_BUS_NUM
4327 If SPD EEPROM is on an I2C bus other than the first
4328 one, specify here. Note that the value must resolve
4329 to something your driver can deal with.
4331 - CONFIG_SYS_DDR_RAW_TIMING
4332 Get DDR timing information from other than SPD. Common with
4333 soldered DDR chips onboard without SPD. DDR raw timing
4334 parameters are extracted from datasheet and hard-coded into
4335 header files or board specific files.
4337 - CONFIG_FSL_DDR_INTERACTIVE
4338 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4340 - CONFIG_SYS_83XX_DDR_USES_CS0
4341 Only for 83xx systems. If specified, then DDR should
4342 be configured using CS0 and CS1 instead of CS2 and CS3.
4344 - CONFIG_ETHER_ON_FEC[12]
4345 Define to enable FEC[12] on a 8xx series processor.
4347 - CONFIG_FEC[12]_PHY
4348 Define to the hardcoded PHY address which corresponds
4349 to the given FEC; i. e.
4350 #define CONFIG_FEC1_PHY 4
4351 means that the PHY with address 4 is connected to FEC1
4353 When set to -1, means to probe for first available.
4355 - CONFIG_FEC[12]_PHY_NORXERR
4356 The PHY does not have a RXERR line (RMII only).
4357 (so program the FEC to ignore it).
4360 Enable RMII mode for all FECs.
4361 Note that this is a global option, we can't
4362 have one FEC in standard MII mode and another in RMII mode.
4364 - CONFIG_CRC32_VERIFY
4365 Add a verify option to the crc32 command.
4368 => crc32 -v <address> <count> <crc32>
4370 Where address/count indicate a memory area
4371 and crc32 is the correct crc32 which the
4375 Add the "loopw" memory command. This only takes effect if
4376 the memory commands are activated globally (CONFIG_CMD_MEM).
4379 Add the "mdc" and "mwc" memory commands. These are cyclic
4384 This command will print 4 bytes (10,11,12,13) each 500 ms.
4386 => mwc.l 100 12345678 10
4387 This command will write 12345678 to address 100 all 10 ms.
4389 This only takes effect if the memory commands are activated
4390 globally (CONFIG_CMD_MEM).
4392 - CONFIG_SKIP_LOWLEVEL_INIT
4393 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4394 low level initializations (like setting up the memory
4395 controller) are omitted and/or U-Boot does not
4396 relocate itself into RAM.
4398 Normally this variable MUST NOT be defined. The only
4399 exception is when U-Boot is loaded (to RAM) by some
4400 other boot loader or by a debugger which performs
4401 these initializations itself.
4404 Modifies the behaviour of start.S when compiling a loader
4405 that is executed before the actual U-Boot. E.g. when
4406 compiling a NAND SPL.
4409 Modifies the behaviour of start.S when compiling a loader
4410 that is executed after the SPL and before the actual U-Boot.
4411 It is loaded by the SPL.
4413 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4414 Only for 85xx systems. If this variable is specified, the section
4415 .resetvec is not kept and the section .bootpg is placed in the
4416 previous 4k of the .text section.
4418 - CONFIG_ARCH_MAP_SYSMEM
4419 Generally U-Boot (and in particular the md command) uses
4420 effective address. It is therefore not necessary to regard
4421 U-Boot address as virtual addresses that need to be translated
4422 to physical addresses. However, sandbox requires this, since
4423 it maintains its own little RAM buffer which contains all
4424 addressable memory. This option causes some memory accesses
4425 to be mapped through map_sysmem() / unmap_sysmem().
4427 - CONFIG_USE_ARCH_MEMCPY
4428 CONFIG_USE_ARCH_MEMSET
4429 If these options are used a optimized version of memcpy/memset will
4430 be used if available. These functions may be faster under some
4431 conditions but may increase the binary size.
4433 - CONFIG_X86_RESET_VECTOR
4434 If defined, the x86 reset vector code is included. This is not
4435 needed when U-Boot is running from Coreboot.
4438 Defines the MPU clock speed (in MHz).
4440 NOTE : currently only supported on AM335x platforms.
4442 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4443 Enables the RTC32K OSC on AM33xx based plattforms
4445 Freescale QE/FMAN Firmware Support:
4446 -----------------------------------
4448 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4449 loading of "firmware", which is encoded in the QE firmware binary format.
4450 This firmware often needs to be loaded during U-Boot booting, so macros
4451 are used to identify the storage device (NOR flash, SPI, etc) and the address
4454 - CONFIG_SYS_QE_FMAN_FW_ADDR
4455 The address in the storage device where the firmware is located. The
4456 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4459 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4460 The maximum possible size of the firmware. The firmware binary format
4461 has a field that specifies the actual size of the firmware, but it
4462 might not be possible to read any part of the firmware unless some
4463 local storage is allocated to hold the entire firmware first.
4465 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4466 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4467 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4468 virtual address in NOR flash.
4470 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4471 Specifies that QE/FMAN firmware is located in NAND flash.
4472 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4474 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4475 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4476 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4478 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4479 Specifies that QE/FMAN firmware is located on the primary SPI
4480 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4482 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4483 Specifies that QE/FMAN firmware is located in the remote (master)
4484 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4485 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4486 window->master inbound window->master LAW->the ucode address in
4487 master's memory space.
4489 Building the Software:
4490 ======================
4492 Building U-Boot has been tested in several native build environments
4493 and in many different cross environments. Of course we cannot support
4494 all possibly existing versions of cross development tools in all
4495 (potentially obsolete) versions. In case of tool chain problems we
4496 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4497 which is extensively used to build and test U-Boot.
4499 If you are not using a native environment, it is assumed that you
4500 have GNU cross compiling tools available in your path. In this case,
4501 you must set the environment variable CROSS_COMPILE in your shell.
4502 Note that no changes to the Makefile or any other source files are
4503 necessary. For example using the ELDK on a 4xx CPU, please enter:
4505 $ CROSS_COMPILE=ppc_4xx-
4506 $ export CROSS_COMPILE
4508 Note: If you wish to generate Windows versions of the utilities in
4509 the tools directory you can use the MinGW toolchain
4510 (http://www.mingw.org). Set your HOST tools to the MinGW
4511 toolchain and execute 'make tools'. For example:
4513 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4515 Binaries such as tools/mkimage.exe will be created which can
4516 be executed on computers running Windows.
4518 U-Boot is intended to be simple to build. After installing the
4519 sources you must configure U-Boot for one specific board type. This
4524 where "NAME_config" is the name of one of the existing configu-
4525 rations; see boards.cfg for supported names.
4527 Note: for some board special configuration names may exist; check if
4528 additional information is available from the board vendor; for
4529 instance, the TQM823L systems are available without (standard)
4530 or with LCD support. You can select such additional "features"
4531 when choosing the configuration, i. e.
4534 - will configure for a plain TQM823L, i. e. no LCD support
4536 make TQM823L_LCD_config
4537 - will configure for a TQM823L with U-Boot console on LCD
4542 Finally, type "make all", and you should get some working U-Boot
4543 images ready for download to / installation on your system:
4545 - "u-boot.bin" is a raw binary image
4546 - "u-boot" is an image in ELF binary format
4547 - "u-boot.srec" is in Motorola S-Record format
4549 By default the build is performed locally and the objects are saved
4550 in the source directory. One of the two methods can be used to change
4551 this behavior and build U-Boot to some external directory:
4553 1. Add O= to the make command line invocations:
4555 make O=/tmp/build distclean
4556 make O=/tmp/build NAME_config
4557 make O=/tmp/build all
4559 2. Set environment variable BUILD_DIR to point to the desired location:
4561 export BUILD_DIR=/tmp/build
4566 Note that the command line "O=" setting overrides the BUILD_DIR environment
4570 Please be aware that the Makefiles assume you are using GNU make, so
4571 for instance on NetBSD you might need to use "gmake" instead of
4575 If the system board that you have is not listed, then you will need
4576 to port U-Boot to your hardware platform. To do this, follow these
4579 1. Add a new configuration option for your board to the toplevel
4580 "boards.cfg" file, using the existing entries as examples.
4581 Follow the instructions there to keep the boards in order.
4582 2. Create a new directory to hold your board specific code. Add any
4583 files you need. In your board directory, you will need at least
4584 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4585 3. Create a new configuration file "include/configs/<board>.h" for
4587 3. If you're porting U-Boot to a new CPU, then also create a new
4588 directory to hold your CPU specific code. Add any files you need.
4589 4. Run "make <board>_config" with your new name.
4590 5. Type "make", and you should get a working "u-boot.srec" file
4591 to be installed on your target system.
4592 6. Debug and solve any problems that might arise.
4593 [Of course, this last step is much harder than it sounds.]
4596 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4597 ==============================================================
4599 If you have modified U-Boot sources (for instance added a new board
4600 or support for new devices, a new CPU, etc.) you are expected to
4601 provide feedback to the other developers. The feedback normally takes
4602 the form of a "patch", i. e. a context diff against a certain (latest
4603 official or latest in the git repository) version of U-Boot sources.
4605 But before you submit such a patch, please verify that your modifi-
4606 cation did not break existing code. At least make sure that *ALL* of
4607 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4608 just run the "MAKEALL" script, which will configure and build U-Boot
4609 for ALL supported system. Be warned, this will take a while. You can
4610 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4611 environment variable to the script, i. e. to use the ELDK cross tools
4614 CROSS_COMPILE=ppc_8xx- MAKEALL
4616 or to build on a native PowerPC system you can type
4618 CROSS_COMPILE=' ' MAKEALL
4620 When using the MAKEALL script, the default behaviour is to build
4621 U-Boot in the source directory. This location can be changed by
4622 setting the BUILD_DIR environment variable. Also, for each target
4623 built, the MAKEALL script saves two log files (<target>.ERR and
4624 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4625 location can be changed by setting the MAKEALL_LOGDIR environment
4626 variable. For example:
4628 export BUILD_DIR=/tmp/build
4629 export MAKEALL_LOGDIR=/tmp/log
4630 CROSS_COMPILE=ppc_8xx- MAKEALL
4632 With the above settings build objects are saved in the /tmp/build,
4633 log files are saved in the /tmp/log and the source tree remains clean
4634 during the whole build process.
4637 See also "U-Boot Porting Guide" below.
4640 Monitor Commands - Overview:
4641 ============================
4643 go - start application at address 'addr'
4644 run - run commands in an environment variable
4645 bootm - boot application image from memory
4646 bootp - boot image via network using BootP/TFTP protocol
4647 bootz - boot zImage from memory
4648 tftpboot- boot image via network using TFTP protocol
4649 and env variables "ipaddr" and "serverip"
4650 (and eventually "gatewayip")
4651 tftpput - upload a file via network using TFTP protocol
4652 rarpboot- boot image via network using RARP/TFTP protocol
4653 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4654 loads - load S-Record file over serial line
4655 loadb - load binary file over serial line (kermit mode)
4657 mm - memory modify (auto-incrementing)
4658 nm - memory modify (constant address)
4659 mw - memory write (fill)
4661 cmp - memory compare
4662 crc32 - checksum calculation
4663 i2c - I2C sub-system
4664 sspi - SPI utility commands
4665 base - print or set address offset
4666 printenv- print environment variables
4667 setenv - set environment variables
4668 saveenv - save environment variables to persistent storage
4669 protect - enable or disable FLASH write protection
4670 erase - erase FLASH memory
4671 flinfo - print FLASH memory information
4672 nand - NAND memory operations (see doc/README.nand)
4673 bdinfo - print Board Info structure
4674 iminfo - print header information for application image
4675 coninfo - print console devices and informations
4676 ide - IDE sub-system
4677 loop - infinite loop on address range
4678 loopw - infinite write loop on address range
4679 mtest - simple RAM test
4680 icache - enable or disable instruction cache
4681 dcache - enable or disable data cache
4682 reset - Perform RESET of the CPU
4683 echo - echo args to console
4684 version - print monitor version
4685 help - print online help
4686 ? - alias for 'help'
4689 Monitor Commands - Detailed Description:
4690 ========================================
4694 For now: just type "help <command>".
4697 Environment Variables:
4698 ======================
4700 U-Boot supports user configuration using Environment Variables which
4701 can be made persistent by saving to Flash memory.
4703 Environment Variables are set using "setenv", printed using
4704 "printenv", and saved to Flash using "saveenv". Using "setenv"
4705 without a value can be used to delete a variable from the
4706 environment. As long as you don't save the environment you are
4707 working with an in-memory copy. In case the Flash area containing the
4708 environment is erased by accident, a default environment is provided.
4710 Some configuration options can be set using Environment Variables.
4712 List of environment variables (most likely not complete):
4714 baudrate - see CONFIG_BAUDRATE
4716 bootdelay - see CONFIG_BOOTDELAY
4718 bootcmd - see CONFIG_BOOTCOMMAND
4720 bootargs - Boot arguments when booting an RTOS image
4722 bootfile - Name of the image to load with TFTP
4724 bootm_low - Memory range available for image processing in the bootm
4725 command can be restricted. This variable is given as
4726 a hexadecimal number and defines lowest address allowed
4727 for use by the bootm command. See also "bootm_size"
4728 environment variable. Address defined by "bootm_low" is
4729 also the base of the initial memory mapping for the Linux
4730 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4733 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4734 This variable is given as a hexadecimal number and it
4735 defines the size of the memory region starting at base
4736 address bootm_low that is accessible by the Linux kernel
4737 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4738 as the default value if it is defined, and bootm_size is
4741 bootm_size - Memory range available for image processing in the bootm
4742 command can be restricted. This variable is given as
4743 a hexadecimal number and defines the size of the region
4744 allowed for use by the bootm command. See also "bootm_low"
4745 environment variable.
4747 updatefile - Location of the software update file on a TFTP server, used
4748 by the automatic software update feature. Please refer to
4749 documentation in doc/README.update for more details.
4751 autoload - if set to "no" (any string beginning with 'n'),
4752 "bootp" will just load perform a lookup of the
4753 configuration from the BOOTP server, but not try to
4754 load any image using TFTP
4756 autostart - if set to "yes", an image loaded using the "bootp",
4757 "rarpboot", "tftpboot" or "diskboot" commands will
4758 be automatically started (by internally calling
4761 If set to "no", a standalone image passed to the
4762 "bootm" command will be copied to the load address
4763 (and eventually uncompressed), but NOT be started.
4764 This can be used to load and uncompress arbitrary
4767 fdt_high - if set this restricts the maximum address that the
4768 flattened device tree will be copied into upon boot.
4769 For example, if you have a system with 1 GB memory
4770 at physical address 0x10000000, while Linux kernel
4771 only recognizes the first 704 MB as low memory, you
4772 may need to set fdt_high as 0x3C000000 to have the
4773 device tree blob be copied to the maximum address
4774 of the 704 MB low memory, so that Linux kernel can
4775 access it during the boot procedure.
4777 If this is set to the special value 0xFFFFFFFF then
4778 the fdt will not be copied at all on boot. For this
4779 to work it must reside in writable memory, have
4780 sufficient padding on the end of it for u-boot to
4781 add the information it needs into it, and the memory
4782 must be accessible by the kernel.
4784 fdtcontroladdr- if set this is the address of the control flattened
4785 device tree used by U-Boot when CONFIG_OF_CONTROL is
4788 i2cfast - (PPC405GP|PPC405EP only)
4789 if set to 'y' configures Linux I2C driver for fast
4790 mode (400kHZ). This environment variable is used in
4791 initialization code. So, for changes to be effective
4792 it must be saved and board must be reset.
4794 initrd_high - restrict positioning of initrd images:
4795 If this variable is not set, initrd images will be
4796 copied to the highest possible address in RAM; this
4797 is usually what you want since it allows for
4798 maximum initrd size. If for some reason you want to
4799 make sure that the initrd image is loaded below the
4800 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4801 variable to a value of "no" or "off" or "0".
4802 Alternatively, you can set it to a maximum upper
4803 address to use (U-Boot will still check that it
4804 does not overwrite the U-Boot stack and data).
4806 For instance, when you have a system with 16 MB
4807 RAM, and want to reserve 4 MB from use by Linux,
4808 you can do this by adding "mem=12M" to the value of
4809 the "bootargs" variable. However, now you must make
4810 sure that the initrd image is placed in the first
4811 12 MB as well - this can be done with
4813 setenv initrd_high 00c00000
4815 If you set initrd_high to 0xFFFFFFFF, this is an
4816 indication to U-Boot that all addresses are legal
4817 for the Linux kernel, including addresses in flash
4818 memory. In this case U-Boot will NOT COPY the
4819 ramdisk at all. This may be useful to reduce the
4820 boot time on your system, but requires that this
4821 feature is supported by your Linux kernel.
4823 ipaddr - IP address; needed for tftpboot command
4825 loadaddr - Default load address for commands like "bootp",
4826 "rarpboot", "tftpboot", "loadb" or "diskboot"
4828 loads_echo - see CONFIG_LOADS_ECHO
4830 serverip - TFTP server IP address; needed for tftpboot command
4832 bootretry - see CONFIG_BOOT_RETRY_TIME
4834 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4836 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4838 ethprime - controls which interface is used first.
4840 ethact - controls which interface is currently active.
4841 For example you can do the following
4843 => setenv ethact FEC
4844 => ping 192.168.0.1 # traffic sent on FEC
4845 => setenv ethact SCC
4846 => ping 10.0.0.1 # traffic sent on SCC
4848 ethrotate - When set to "no" U-Boot does not go through all
4849 available network interfaces.
4850 It just stays at the currently selected interface.
4852 netretry - When set to "no" each network operation will
4853 either succeed or fail without retrying.
4854 When set to "once" the network operation will
4855 fail when all the available network interfaces
4856 are tried once without success.
4857 Useful on scripts which control the retry operation
4860 npe_ucode - set load address for the NPE microcode
4862 silent_linux - If set then linux will be told to boot silently, by
4863 changing the console to be empty. If "yes" it will be
4864 made silent. If "no" it will not be made silent. If
4865 unset, then it will be made silent if the U-Boot console
4868 tftpsrcport - If this is set, the value is used for TFTP's
4871 tftpdstport - If this is set, the value is used for TFTP's UDP
4872 destination port instead of the Well Know Port 69.
4874 tftpblocksize - Block size to use for TFTP transfers; if not set,
4875 we use the TFTP server's default block size
4877 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4878 seconds, minimum value is 1000 = 1 second). Defines
4879 when a packet is considered to be lost so it has to
4880 be retransmitted. The default is 5000 = 5 seconds.
4881 Lowering this value may make downloads succeed
4882 faster in networks with high packet loss rates or
4883 with unreliable TFTP servers.
4885 vlan - When set to a value < 4095 the traffic over
4886 Ethernet is encapsulated/received over 802.1q
4889 The following image location variables contain the location of images
4890 used in booting. The "Image" column gives the role of the image and is
4891 not an environment variable name. The other columns are environment
4892 variable names. "File Name" gives the name of the file on a TFTP
4893 server, "RAM Address" gives the location in RAM the image will be
4894 loaded to, and "Flash Location" gives the image's address in NOR
4895 flash or offset in NAND flash.
4897 *Note* - these variables don't have to be defined for all boards, some
4898 boards currenlty use other variables for these purposes, and some
4899 boards use these variables for other purposes.
4901 Image File Name RAM Address Flash Location
4902 ----- --------- ----------- --------------
4903 u-boot u-boot u-boot_addr_r u-boot_addr
4904 Linux kernel bootfile kernel_addr_r kernel_addr
4905 device tree blob fdtfile fdt_addr_r fdt_addr
4906 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4908 The following environment variables may be used and automatically
4909 updated by the network boot commands ("bootp" and "rarpboot"),
4910 depending the information provided by your boot server:
4912 bootfile - see above
4913 dnsip - IP address of your Domain Name Server
4914 dnsip2 - IP address of your secondary Domain Name Server
4915 gatewayip - IP address of the Gateway (Router) to use
4916 hostname - Target hostname
4918 netmask - Subnet Mask
4919 rootpath - Pathname of the root filesystem on the NFS server
4920 serverip - see above
4923 There are two special Environment Variables:
4925 serial# - contains hardware identification information such
4926 as type string and/or serial number
4927 ethaddr - Ethernet address
4929 These variables can be set only once (usually during manufacturing of
4930 the board). U-Boot refuses to delete or overwrite these variables
4931 once they have been set once.
4934 Further special Environment Variables:
4936 ver - Contains the U-Boot version string as printed
4937 with the "version" command. This variable is
4938 readonly (see CONFIG_VERSION_VARIABLE).
4941 Please note that changes to some configuration parameters may take
4942 only effect after the next boot (yes, that's just like Windoze :-).
4945 Callback functions for environment variables:
4946 ---------------------------------------------
4948 For some environment variables, the behavior of u-boot needs to change
4949 when their values are changed. This functionailty allows functions to
4950 be associated with arbitrary variables. On creation, overwrite, or
4951 deletion, the callback will provide the opportunity for some side
4952 effect to happen or for the change to be rejected.
4954 The callbacks are named and associated with a function using the
4955 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4957 These callbacks are associated with variables in one of two ways. The
4958 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4959 in the board configuration to a string that defines a list of
4960 associations. The list must be in the following format:
4962 entry = variable_name[:callback_name]
4965 If the callback name is not specified, then the callback is deleted.
4966 Spaces are also allowed anywhere in the list.
4968 Callbacks can also be associated by defining the ".callbacks" variable
4969 with the same list format above. Any association in ".callbacks" will
4970 override any association in the static list. You can define
4971 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4972 ".callbacks" envirnoment variable in the default or embedded environment.
4975 Command Line Parsing:
4976 =====================
4978 There are two different command line parsers available with U-Boot:
4979 the old "simple" one, and the much more powerful "hush" shell:
4981 Old, simple command line parser:
4982 --------------------------------
4984 - supports environment variables (through setenv / saveenv commands)
4985 - several commands on one line, separated by ';'
4986 - variable substitution using "... ${name} ..." syntax
4987 - special characters ('$', ';') can be escaped by prefixing with '\',
4989 setenv bootcmd bootm \${address}
4990 - You can also escape text by enclosing in single apostrophes, for example:
4991 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4996 - similar to Bourne shell, with control structures like
4997 if...then...else...fi, for...do...done; while...do...done,
4998 until...do...done, ...
4999 - supports environment ("global") variables (through setenv / saveenv
5000 commands) and local shell variables (through standard shell syntax
5001 "name=value"); only environment variables can be used with "run"
5007 (1) If a command line (or an environment variable executed by a "run"
5008 command) contains several commands separated by semicolon, and
5009 one of these commands fails, then the remaining commands will be
5012 (2) If you execute several variables with one call to run (i. e.
5013 calling run with a list of variables as arguments), any failing
5014 command will cause "run" to terminate, i. e. the remaining
5015 variables are not executed.
5017 Note for Redundant Ethernet Interfaces:
5018 =======================================
5020 Some boards come with redundant Ethernet interfaces; U-Boot supports
5021 such configurations and is capable of automatic selection of a
5022 "working" interface when needed. MAC assignment works as follows:
5024 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5025 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5026 "eth1addr" (=>eth1), "eth2addr", ...
5028 If the network interface stores some valid MAC address (for instance
5029 in SROM), this is used as default address if there is NO correspon-
5030 ding setting in the environment; if the corresponding environment
5031 variable is set, this overrides the settings in the card; that means:
5033 o If the SROM has a valid MAC address, and there is no address in the
5034 environment, the SROM's address is used.
5036 o If there is no valid address in the SROM, and a definition in the
5037 environment exists, then the value from the environment variable is
5040 o If both the SROM and the environment contain a MAC address, and
5041 both addresses are the same, this MAC address is used.
5043 o If both the SROM and the environment contain a MAC address, and the
5044 addresses differ, the value from the environment is used and a
5047 o If neither SROM nor the environment contain a MAC address, an error
5050 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5051 will be programmed into hardware as part of the initialization process. This
5052 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5053 The naming convention is as follows:
5054 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5059 U-Boot is capable of booting (and performing other auxiliary operations on)
5060 images in two formats:
5062 New uImage format (FIT)
5063 -----------------------
5065 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5066 to Flattened Device Tree). It allows the use of images with multiple
5067 components (several kernels, ramdisks, etc.), with contents protected by
5068 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5074 Old image format is based on binary files which can be basically anything,
5075 preceded by a special header; see the definitions in include/image.h for
5076 details; basically, the header defines the following image properties:
5078 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5079 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5080 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5081 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5083 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5084 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5085 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5086 * Compression Type (uncompressed, gzip, bzip2)
5092 The header is marked by a special Magic Number, and both the header
5093 and the data portions of the image are secured against corruption by
5100 Although U-Boot should support any OS or standalone application
5101 easily, the main focus has always been on Linux during the design of
5104 U-Boot includes many features that so far have been part of some
5105 special "boot loader" code within the Linux kernel. Also, any
5106 "initrd" images to be used are no longer part of one big Linux image;
5107 instead, kernel and "initrd" are separate images. This implementation
5108 serves several purposes:
5110 - the same features can be used for other OS or standalone
5111 applications (for instance: using compressed images to reduce the
5112 Flash memory footprint)
5114 - it becomes much easier to port new Linux kernel versions because
5115 lots of low-level, hardware dependent stuff are done by U-Boot
5117 - the same Linux kernel image can now be used with different "initrd"
5118 images; of course this also means that different kernel images can
5119 be run with the same "initrd". This makes testing easier (you don't
5120 have to build a new "zImage.initrd" Linux image when you just
5121 change a file in your "initrd"). Also, a field-upgrade of the
5122 software is easier now.
5128 Porting Linux to U-Boot based systems:
5129 ---------------------------------------
5131 U-Boot cannot save you from doing all the necessary modifications to
5132 configure the Linux device drivers for use with your target hardware
5133 (no, we don't intend to provide a full virtual machine interface to
5136 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5138 Just make sure your machine specific header file (for instance
5139 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5140 Information structure as we define in include/asm-<arch>/u-boot.h,
5141 and make sure that your definition of IMAP_ADDR uses the same value
5142 as your U-Boot configuration in CONFIG_SYS_IMMR.
5145 Configuring the Linux kernel:
5146 -----------------------------
5148 No specific requirements for U-Boot. Make sure you have some root
5149 device (initial ramdisk, NFS) for your target system.
5152 Building a Linux Image:
5153 -----------------------
5155 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5156 not used. If you use recent kernel source, a new build target
5157 "uImage" will exist which automatically builds an image usable by
5158 U-Boot. Most older kernels also have support for a "pImage" target,
5159 which was introduced for our predecessor project PPCBoot and uses a
5160 100% compatible format.
5169 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5170 encapsulate a compressed Linux kernel image with header information,
5171 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5173 * build a standard "vmlinux" kernel image (in ELF binary format):
5175 * convert the kernel into a raw binary image:
5177 ${CROSS_COMPILE}-objcopy -O binary \
5178 -R .note -R .comment \
5179 -S vmlinux linux.bin
5181 * compress the binary image:
5185 * package compressed binary image for U-Boot:
5187 mkimage -A ppc -O linux -T kernel -C gzip \
5188 -a 0 -e 0 -n "Linux Kernel Image" \
5189 -d linux.bin.gz uImage
5192 The "mkimage" tool can also be used to create ramdisk images for use
5193 with U-Boot, either separated from the Linux kernel image, or
5194 combined into one file. "mkimage" encapsulates the images with a 64
5195 byte header containing information about target architecture,
5196 operating system, image type, compression method, entry points, time
5197 stamp, CRC32 checksums, etc.
5199 "mkimage" can be called in two ways: to verify existing images and
5200 print the header information, or to build new images.
5202 In the first form (with "-l" option) mkimage lists the information
5203 contained in the header of an existing U-Boot image; this includes
5204 checksum verification:
5206 tools/mkimage -l image
5207 -l ==> list image header information
5209 The second form (with "-d" option) is used to build a U-Boot image
5210 from a "data file" which is used as image payload:
5212 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5213 -n name -d data_file image
5214 -A ==> set architecture to 'arch'
5215 -O ==> set operating system to 'os'
5216 -T ==> set image type to 'type'
5217 -C ==> set compression type 'comp'
5218 -a ==> set load address to 'addr' (hex)
5219 -e ==> set entry point to 'ep' (hex)
5220 -n ==> set image name to 'name'
5221 -d ==> use image data from 'datafile'
5223 Right now, all Linux kernels for PowerPC systems use the same load
5224 address (0x00000000), but the entry point address depends on the
5227 - 2.2.x kernels have the entry point at 0x0000000C,
5228 - 2.3.x and later kernels have the entry point at 0x00000000.
5230 So a typical call to build a U-Boot image would read:
5232 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5233 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5234 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5235 > examples/uImage.TQM850L
5236 Image Name: 2.4.4 kernel for TQM850L
5237 Created: Wed Jul 19 02:34:59 2000
5238 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5239 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5240 Load Address: 0x00000000
5241 Entry Point: 0x00000000
5243 To verify the contents of the image (or check for corruption):
5245 -> tools/mkimage -l examples/uImage.TQM850L
5246 Image Name: 2.4.4 kernel for TQM850L
5247 Created: Wed Jul 19 02:34:59 2000
5248 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5249 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5250 Load Address: 0x00000000
5251 Entry Point: 0x00000000
5253 NOTE: for embedded systems where boot time is critical you can trade
5254 speed for memory and install an UNCOMPRESSED image instead: this
5255 needs more space in Flash, but boots much faster since it does not
5256 need to be uncompressed:
5258 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5259 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5260 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5261 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5262 > examples/uImage.TQM850L-uncompressed
5263 Image Name: 2.4.4 kernel for TQM850L
5264 Created: Wed Jul 19 02:34:59 2000
5265 Image Type: PowerPC Linux Kernel Image (uncompressed)
5266 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5267 Load Address: 0x00000000
5268 Entry Point: 0x00000000
5271 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5272 when your kernel is intended to use an initial ramdisk:
5274 -> tools/mkimage -n 'Simple Ramdisk Image' \
5275 > -A ppc -O linux -T ramdisk -C gzip \
5276 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5277 Image Name: Simple Ramdisk Image
5278 Created: Wed Jan 12 14:01:50 2000
5279 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5280 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5281 Load Address: 0x00000000
5282 Entry Point: 0x00000000
5284 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5285 option performs the converse operation of the mkimage's second form (the "-d"
5286 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5289 tools/dumpimage -i image -p position data_file
5290 -i ==> extract from the 'image' a specific 'data_file', \
5291 indexed by 'position'
5294 Installing a Linux Image:
5295 -------------------------
5297 To downloading a U-Boot image over the serial (console) interface,
5298 you must convert the image to S-Record format:
5300 objcopy -I binary -O srec examples/image examples/image.srec
5302 The 'objcopy' does not understand the information in the U-Boot
5303 image header, so the resulting S-Record file will be relative to
5304 address 0x00000000. To load it to a given address, you need to
5305 specify the target address as 'offset' parameter with the 'loads'
5308 Example: install the image to address 0x40100000 (which on the
5309 TQM8xxL is in the first Flash bank):
5311 => erase 40100000 401FFFFF
5317 ## Ready for S-Record download ...
5318 ~>examples/image.srec
5319 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5321 15989 15990 15991 15992
5322 [file transfer complete]
5324 ## Start Addr = 0x00000000
5327 You can check the success of the download using the 'iminfo' command;
5328 this includes a checksum verification so you can be sure no data
5329 corruption happened:
5333 ## Checking Image at 40100000 ...
5334 Image Name: 2.2.13 for initrd on TQM850L
5335 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5336 Data Size: 335725 Bytes = 327 kB = 0 MB
5337 Load Address: 00000000
5338 Entry Point: 0000000c
5339 Verifying Checksum ... OK
5345 The "bootm" command is used to boot an application that is stored in
5346 memory (RAM or Flash). In case of a Linux kernel image, the contents
5347 of the "bootargs" environment variable is passed to the kernel as
5348 parameters. You can check and modify this variable using the
5349 "printenv" and "setenv" commands:
5352 => printenv bootargs
5353 bootargs=root=/dev/ram
5355 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5357 => printenv bootargs
5358 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5361 ## Booting Linux kernel at 40020000 ...
5362 Image Name: 2.2.13 for NFS on TQM850L
5363 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5364 Data Size: 381681 Bytes = 372 kB = 0 MB
5365 Load Address: 00000000
5366 Entry Point: 0000000c
5367 Verifying Checksum ... OK
5368 Uncompressing Kernel Image ... OK
5369 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
5370 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5371 time_init: decrementer frequency = 187500000/60
5372 Calibrating delay loop... 49.77 BogoMIPS
5373 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5376 If you want to boot a Linux kernel with initial RAM disk, you pass
5377 the memory addresses of both the kernel and the initrd image (PPBCOOT
5378 format!) to the "bootm" command:
5380 => imi 40100000 40200000
5382 ## Checking Image at 40100000 ...
5383 Image Name: 2.2.13 for initrd on TQM850L
5384 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5385 Data Size: 335725 Bytes = 327 kB = 0 MB
5386 Load Address: 00000000
5387 Entry Point: 0000000c
5388 Verifying Checksum ... OK
5390 ## Checking Image at 40200000 ...
5391 Image Name: Simple Ramdisk Image
5392 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5393 Data Size: 566530 Bytes = 553 kB = 0 MB
5394 Load Address: 00000000
5395 Entry Point: 00000000
5396 Verifying Checksum ... OK
5398 => bootm 40100000 40200000
5399 ## Booting Linux kernel at 40100000 ...
5400 Image Name: 2.2.13 for initrd on TQM850L
5401 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5402 Data Size: 335725 Bytes = 327 kB = 0 MB
5403 Load Address: 00000000
5404 Entry Point: 0000000c
5405 Verifying Checksum ... OK
5406 Uncompressing Kernel Image ... OK
5407 ## Loading RAMDisk Image at 40200000 ...
5408 Image Name: Simple Ramdisk Image
5409 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5410 Data Size: 566530 Bytes = 553 kB = 0 MB
5411 Load Address: 00000000
5412 Entry Point: 00000000
5413 Verifying Checksum ... OK
5414 Loading Ramdisk ... OK
5415 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
5416 Boot arguments: root=/dev/ram
5417 time_init: decrementer frequency = 187500000/60
5418 Calibrating delay loop... 49.77 BogoMIPS
5420 RAMDISK: Compressed image found at block 0
5421 VFS: Mounted root (ext2 filesystem).
5425 Boot Linux and pass a flat device tree:
5428 First, U-Boot must be compiled with the appropriate defines. See the section
5429 titled "Linux Kernel Interface" above for a more in depth explanation. The
5430 following is an example of how to start a kernel and pass an updated
5436 oft=oftrees/mpc8540ads.dtb
5437 => tftp $oftaddr $oft
5438 Speed: 1000, full duplex
5440 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5441 Filename 'oftrees/mpc8540ads.dtb'.
5442 Load address: 0x300000
5445 Bytes transferred = 4106 (100a hex)
5446 => tftp $loadaddr $bootfile
5447 Speed: 1000, full duplex
5449 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5451 Load address: 0x200000
5452 Loading:############
5454 Bytes transferred = 1029407 (fb51f hex)
5459 => bootm $loadaddr - $oftaddr
5460 ## Booting image at 00200000 ...
5461 Image Name: Linux-2.6.17-dirty
5462 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5463 Data Size: 1029343 Bytes = 1005.2 kB
5464 Load Address: 00000000
5465 Entry Point: 00000000
5466 Verifying Checksum ... OK
5467 Uncompressing Kernel Image ... OK
5468 Booting using flat device tree at 0x300000
5469 Using MPC85xx ADS machine description
5470 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5474 More About U-Boot Image Types:
5475 ------------------------------
5477 U-Boot supports the following image types:
5479 "Standalone Programs" are directly runnable in the environment
5480 provided by U-Boot; it is expected that (if they behave
5481 well) you can continue to work in U-Boot after return from
5482 the Standalone Program.
5483 "OS Kernel Images" are usually images of some Embedded OS which
5484 will take over control completely. Usually these programs
5485 will install their own set of exception handlers, device
5486 drivers, set up the MMU, etc. - this means, that you cannot
5487 expect to re-enter U-Boot except by resetting the CPU.
5488 "RAMDisk Images" are more or less just data blocks, and their
5489 parameters (address, size) are passed to an OS kernel that is
5491 "Multi-File Images" contain several images, typically an OS
5492 (Linux) kernel image and one or more data images like
5493 RAMDisks. This construct is useful for instance when you want
5494 to boot over the network using BOOTP etc., where the boot
5495 server provides just a single image file, but you want to get
5496 for instance an OS kernel and a RAMDisk image.
5498 "Multi-File Images" start with a list of image sizes, each
5499 image size (in bytes) specified by an "uint32_t" in network
5500 byte order. This list is terminated by an "(uint32_t)0".
5501 Immediately after the terminating 0 follow the images, one by
5502 one, all aligned on "uint32_t" boundaries (size rounded up to
5503 a multiple of 4 bytes).
5505 "Firmware Images" are binary images containing firmware (like
5506 U-Boot or FPGA images) which usually will be programmed to
5509 "Script files" are command sequences that will be executed by
5510 U-Boot's command interpreter; this feature is especially
5511 useful when you configure U-Boot to use a real shell (hush)
5512 as command interpreter.
5514 Booting the Linux zImage:
5515 -------------------------
5517 On some platforms, it's possible to boot Linux zImage. This is done
5518 using the "bootz" command. The syntax of "bootz" command is the same
5519 as the syntax of "bootm" command.
5521 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5522 kernel with raw initrd images. The syntax is slightly different, the
5523 address of the initrd must be augmented by it's size, in the following
5524 format: "<initrd addres>:<initrd size>".
5530 One of the features of U-Boot is that you can dynamically load and
5531 run "standalone" applications, which can use some resources of
5532 U-Boot like console I/O functions or interrupt services.
5534 Two simple examples are included with the sources:
5539 'examples/hello_world.c' contains a small "Hello World" Demo
5540 application; it is automatically compiled when you build U-Boot.
5541 It's configured to run at address 0x00040004, so you can play with it
5545 ## Ready for S-Record download ...
5546 ~>examples/hello_world.srec
5547 1 2 3 4 5 6 7 8 9 10 11 ...
5548 [file transfer complete]
5550 ## Start Addr = 0x00040004
5552 => go 40004 Hello World! This is a test.
5553 ## Starting application at 0x00040004 ...
5564 Hit any key to exit ...
5566 ## Application terminated, rc = 0x0
5568 Another example, which demonstrates how to register a CPM interrupt
5569 handler with the U-Boot code, can be found in 'examples/timer.c'.
5570 Here, a CPM timer is set up to generate an interrupt every second.
5571 The interrupt service routine is trivial, just printing a '.'
5572 character, but this is just a demo program. The application can be
5573 controlled by the following keys:
5575 ? - print current values og the CPM Timer registers
5576 b - enable interrupts and start timer
5577 e - stop timer and disable interrupts
5578 q - quit application
5581 ## Ready for S-Record download ...
5582 ~>examples/timer.srec
5583 1 2 3 4 5 6 7 8 9 10 11 ...
5584 [file transfer complete]
5586 ## Start Addr = 0x00040004
5589 ## Starting application at 0x00040004 ...
5592 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5595 [q, b, e, ?] Set interval 1000000 us
5598 [q, b, e, ?] ........
5599 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5602 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5605 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5608 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5610 [q, b, e, ?] ...Stopping timer
5612 [q, b, e, ?] ## Application terminated, rc = 0x0
5618 Over time, many people have reported problems when trying to use the
5619 "minicom" terminal emulation program for serial download. I (wd)
5620 consider minicom to be broken, and recommend not to use it. Under
5621 Unix, I recommend to use C-Kermit for general purpose use (and
5622 especially for kermit binary protocol download ("loadb" command), and
5623 use "cu" for S-Record download ("loads" command). See
5624 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5625 for help with kermit.
5628 Nevertheless, if you absolutely want to use it try adding this
5629 configuration to your "File transfer protocols" section:
5631 Name Program Name U/D FullScr IO-Red. Multi
5632 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5633 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5639 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5640 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5642 Building requires a cross environment; it is known to work on
5643 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5644 need gmake since the Makefiles are not compatible with BSD make).
5645 Note that the cross-powerpc package does not install include files;
5646 attempting to build U-Boot will fail because <machine/ansi.h> is
5647 missing. This file has to be installed and patched manually:
5649 # cd /usr/pkg/cross/powerpc-netbsd/include
5651 # ln -s powerpc machine
5652 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5653 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5655 Native builds *don't* work due to incompatibilities between native
5656 and U-Boot include files.
5658 Booting assumes that (the first part of) the image booted is a
5659 stage-2 loader which in turn loads and then invokes the kernel
5660 proper. Loader sources will eventually appear in the NetBSD source
5661 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5662 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5665 Implementation Internals:
5666 =========================
5668 The following is not intended to be a complete description of every
5669 implementation detail. However, it should help to understand the
5670 inner workings of U-Boot and make it easier to port it to custom
5674 Initial Stack, Global Data:
5675 ---------------------------
5677 The implementation of U-Boot is complicated by the fact that U-Boot
5678 starts running out of ROM (flash memory), usually without access to
5679 system RAM (because the memory controller is not initialized yet).
5680 This means that we don't have writable Data or BSS segments, and BSS
5681 is not initialized as zero. To be able to get a C environment working
5682 at all, we have to allocate at least a minimal stack. Implementation
5683 options for this are defined and restricted by the CPU used: Some CPU
5684 models provide on-chip memory (like the IMMR area on MPC8xx and
5685 MPC826x processors), on others (parts of) the data cache can be
5686 locked as (mis-) used as memory, etc.
5688 Chris Hallinan posted a good summary of these issues to the
5689 U-Boot mailing list:
5691 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5692 From: "Chris Hallinan" <clh@net1plus.com>
5693 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5696 Correct me if I'm wrong, folks, but the way I understand it
5697 is this: Using DCACHE as initial RAM for Stack, etc, does not
5698 require any physical RAM backing up the cache. The cleverness
5699 is that the cache is being used as a temporary supply of
5700 necessary storage before the SDRAM controller is setup. It's
5701 beyond the scope of this list to explain the details, but you
5702 can see how this works by studying the cache architecture and
5703 operation in the architecture and processor-specific manuals.
5705 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5706 is another option for the system designer to use as an
5707 initial stack/RAM area prior to SDRAM being available. Either
5708 option should work for you. Using CS 4 should be fine if your
5709 board designers haven't used it for something that would
5710 cause you grief during the initial boot! It is frequently not
5713 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5714 with your processor/board/system design. The default value
5715 you will find in any recent u-boot distribution in
5716 walnut.h should work for you. I'd set it to a value larger
5717 than your SDRAM module. If you have a 64MB SDRAM module, set
5718 it above 400_0000. Just make sure your board has no resources
5719 that are supposed to respond to that address! That code in
5720 start.S has been around a while and should work as is when
5721 you get the config right.
5726 It is essential to remember this, since it has some impact on the C
5727 code for the initialization procedures:
5729 * Initialized global data (data segment) is read-only. Do not attempt
5732 * Do not use any uninitialized global data (or implicitely initialized
5733 as zero data - BSS segment) at all - this is undefined, initiali-
5734 zation is performed later (when relocating to RAM).
5736 * Stack space is very limited. Avoid big data buffers or things like
5739 Having only the stack as writable memory limits means we cannot use
5740 normal global data to share information beween the code. But it
5741 turned out that the implementation of U-Boot can be greatly
5742 simplified by making a global data structure (gd_t) available to all
5743 functions. We could pass a pointer to this data as argument to _all_
5744 functions, but this would bloat the code. Instead we use a feature of
5745 the GCC compiler (Global Register Variables) to share the data: we
5746 place a pointer (gd) to the global data into a register which we
5747 reserve for this purpose.
5749 When choosing a register for such a purpose we are restricted by the
5750 relevant (E)ABI specifications for the current architecture, and by
5751 GCC's implementation.
5753 For PowerPC, the following registers have specific use:
5755 R2: reserved for system use
5756 R3-R4: parameter passing and return values
5757 R5-R10: parameter passing
5758 R13: small data area pointer
5762 (U-Boot also uses R12 as internal GOT pointer. r12
5763 is a volatile register so r12 needs to be reset when
5764 going back and forth between asm and C)
5766 ==> U-Boot will use R2 to hold a pointer to the global data
5768 Note: on PPC, we could use a static initializer (since the
5769 address of the global data structure is known at compile time),
5770 but it turned out that reserving a register results in somewhat
5771 smaller code - although the code savings are not that big (on
5772 average for all boards 752 bytes for the whole U-Boot image,
5773 624 text + 127 data).
5775 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5776 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5778 ==> U-Boot will use P3 to hold a pointer to the global data
5780 On ARM, the following registers are used:
5782 R0: function argument word/integer result
5783 R1-R3: function argument word
5784 R9: platform specific
5785 R10: stack limit (used only if stack checking is enabled)
5786 R11: argument (frame) pointer
5787 R12: temporary workspace
5790 R15: program counter
5792 ==> U-Boot will use R9 to hold a pointer to the global data
5794 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5796 On Nios II, the ABI is documented here:
5797 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5799 ==> U-Boot will use gp to hold a pointer to the global data
5801 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5802 to access small data sections, so gp is free.
5804 On NDS32, the following registers are used:
5806 R0-R1: argument/return
5808 R15: temporary register for assembler
5809 R16: trampoline register
5810 R28: frame pointer (FP)
5811 R29: global pointer (GP)
5812 R30: link register (LP)
5813 R31: stack pointer (SP)
5814 PC: program counter (PC)
5816 ==> U-Boot will use R10 to hold a pointer to the global data
5818 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5819 or current versions of GCC may "optimize" the code too much.
5824 U-Boot runs in system state and uses physical addresses, i.e. the
5825 MMU is not used either for address mapping nor for memory protection.
5827 The available memory is mapped to fixed addresses using the memory
5828 controller. In this process, a contiguous block is formed for each
5829 memory type (Flash, SDRAM, SRAM), even when it consists of several
5830 physical memory banks.
5832 U-Boot is installed in the first 128 kB of the first Flash bank (on
5833 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5834 booting and sizing and initializing DRAM, the code relocates itself
5835 to the upper end of DRAM. Immediately below the U-Boot code some
5836 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5837 configuration setting]. Below that, a structure with global Board
5838 Info data is placed, followed by the stack (growing downward).
5840 Additionally, some exception handler code is copied to the low 8 kB
5841 of DRAM (0x00000000 ... 0x00001FFF).
5843 So a typical memory configuration with 16 MB of DRAM could look like
5846 0x0000 0000 Exception Vector code
5849 0x0000 2000 Free for Application Use
5855 0x00FB FF20 Monitor Stack (Growing downward)
5856 0x00FB FFAC Board Info Data and permanent copy of global data
5857 0x00FC 0000 Malloc Arena
5860 0x00FE 0000 RAM Copy of Monitor Code
5861 ... eventually: LCD or video framebuffer
5862 ... eventually: pRAM (Protected RAM - unchanged by reset)
5863 0x00FF FFFF [End of RAM]
5866 System Initialization:
5867 ----------------------
5869 In the reset configuration, U-Boot starts at the reset entry point
5870 (on most PowerPC systems at address 0x00000100). Because of the reset
5871 configuration for CS0# this is a mirror of the onboard Flash memory.
5872 To be able to re-map memory U-Boot then jumps to its link address.
5873 To be able to implement the initialization code in C, a (small!)
5874 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5875 which provide such a feature like MPC8xx or MPC8260), or in a locked
5876 part of the data cache. After that, U-Boot initializes the CPU core,
5877 the caches and the SIU.
5879 Next, all (potentially) available memory banks are mapped using a
5880 preliminary mapping. For example, we put them on 512 MB boundaries
5881 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5882 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5883 programmed for SDRAM access. Using the temporary configuration, a
5884 simple memory test is run that determines the size of the SDRAM
5887 When there is more than one SDRAM bank, and the banks are of
5888 different size, the largest is mapped first. For equal size, the first
5889 bank (CS2#) is mapped first. The first mapping is always for address
5890 0x00000000, with any additional banks following immediately to create
5891 contiguous memory starting from 0.
5893 Then, the monitor installs itself at the upper end of the SDRAM area
5894 and allocates memory for use by malloc() and for the global Board
5895 Info data; also, the exception vector code is copied to the low RAM
5896 pages, and the final stack is set up.
5898 Only after this relocation will you have a "normal" C environment;
5899 until that you are restricted in several ways, mostly because you are
5900 running from ROM, and because the code will have to be relocated to a
5904 U-Boot Porting Guide:
5905 ----------------------
5907 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5911 int main(int argc, char *argv[])
5913 sighandler_t no_more_time;
5915 signal(SIGALRM, no_more_time);
5916 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5918 if (available_money > available_manpower) {
5919 Pay consultant to port U-Boot;
5923 Download latest U-Boot source;
5925 Subscribe to u-boot mailing list;
5928 email("Hi, I am new to U-Boot, how do I get started?");
5931 Read the README file in the top level directory;
5932 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5933 Read applicable doc/*.README;
5934 Read the source, Luke;
5935 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5938 if (available_money > toLocalCurrency ($2500))
5941 Add a lot of aggravation and time;
5943 if (a similar board exists) { /* hopefully... */
5944 cp -a board/<similar> board/<myboard>
5945 cp include/configs/<similar>.h include/configs/<myboard>.h
5947 Create your own board support subdirectory;
5948 Create your own board include/configs/<myboard>.h file;
5950 Edit new board/<myboard> files
5951 Edit new include/configs/<myboard>.h
5956 Add / modify source code;
5960 email("Hi, I am having problems...");
5962 Send patch file to the U-Boot email list;
5963 if (reasonable critiques)
5964 Incorporate improvements from email list code review;
5966 Defend code as written;
5972 void no_more_time (int sig)
5981 All contributions to U-Boot should conform to the Linux kernel
5982 coding style; see the file "Documentation/CodingStyle" and the script
5983 "scripts/Lindent" in your Linux kernel source directory.
5985 Source files originating from a different project (for example the
5986 MTD subsystem) are generally exempt from these guidelines and are not
5987 reformated to ease subsequent migration to newer versions of those
5990 Please note that U-Boot is implemented in C (and to some small parts in
5991 Assembler); no C++ is used, so please do not use C++ style comments (//)
5994 Please also stick to the following formatting rules:
5995 - remove any trailing white space
5996 - use TAB characters for indentation and vertical alignment, not spaces
5997 - make sure NOT to use DOS '\r\n' line feeds
5998 - do not add more than 2 consecutive empty lines to source files
5999 - do not add trailing empty lines to source files
6001 Submissions which do not conform to the standards may be returned
6002 with a request to reformat the changes.
6008 Since the number of patches for U-Boot is growing, we need to
6009 establish some rules. Submissions which do not conform to these rules
6010 may be rejected, even when they contain important and valuable stuff.
6012 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6014 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6015 see http://lists.denx.de/mailman/listinfo/u-boot
6017 When you send a patch, please include the following information with
6020 * For bug fixes: a description of the bug and how your patch fixes
6021 this bug. Please try to include a way of demonstrating that the
6022 patch actually fixes something.
6024 * For new features: a description of the feature and your
6027 * A CHANGELOG entry as plaintext (separate from the patch)
6029 * For major contributions, your entry to the CREDITS file
6031 * When you add support for a new board, don't forget to add a
6032 maintainer e-mail address to the boards.cfg file, too.
6034 * If your patch adds new configuration options, don't forget to
6035 document these in the README file.
6037 * The patch itself. If you are using git (which is *strongly*
6038 recommended) you can easily generate the patch using the
6039 "git format-patch". If you then use "git send-email" to send it to
6040 the U-Boot mailing list, you will avoid most of the common problems
6041 with some other mail clients.
6043 If you cannot use git, use "diff -purN OLD NEW". If your version of
6044 diff does not support these options, then get the latest version of
6047 The current directory when running this command shall be the parent
6048 directory of the U-Boot source tree (i. e. please make sure that
6049 your patch includes sufficient directory information for the
6052 We prefer patches as plain text. MIME attachments are discouraged,
6053 and compressed attachments must not be used.
6055 * If one logical set of modifications affects or creates several
6056 files, all these changes shall be submitted in a SINGLE patch file.
6058 * Changesets that contain different, unrelated modifications shall be
6059 submitted as SEPARATE patches, one patch per changeset.
6064 * Before sending the patch, run the MAKEALL script on your patched
6065 source tree and make sure that no errors or warnings are reported
6066 for any of the boards.
6068 * Keep your modifications to the necessary minimum: A patch
6069 containing several unrelated changes or arbitrary reformats will be
6070 returned with a request to re-formatting / split it.
6072 * If you modify existing code, make sure that your new code does not
6073 add to the memory footprint of the code ;-) Small is beautiful!
6074 When adding new features, these should compile conditionally only
6075 (using #ifdef), and the resulting code with the new feature
6076 disabled must not need more memory than the old code without your
6079 * Remember that there is a size limit of 100 kB per message on the
6080 u-boot mailing list. Bigger patches will be moderated. If they are
6081 reasonable and not too big, they will be acknowledged. But patches
6082 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob