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 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /mpc5xx Files specific to Freescale MPC5xx CPUs
186 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
187 /mpc8xx Files specific to Freescale MPC8xx CPUs
188 /mpc8260 Files specific to Freescale MPC8260 CPUs
189 /mpc85xx Files specific to Freescale MPC85xx CPUs
190 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
191 /lib Architecture specific library files
192 /sh Files generic to SH architecture
193 /cpu CPU specific files
194 /sh2 Files specific to sh2 CPUs
195 /sh3 Files specific to sh3 CPUs
196 /sh4 Files specific to sh4 CPUs
197 /lib Architecture specific library files
198 /sparc Files generic to SPARC architecture
199 /cpu CPU specific files
200 /leon2 Files specific to Gaisler LEON2 SPARC CPU
201 /leon3 Files specific to Gaisler LEON3 SPARC CPU
202 /lib Architecture specific library files
203 /x86 Files generic to x86 architecture
204 /cpu CPU specific files
205 /lib Architecture specific library files
206 /api Machine/arch independent API for external apps
207 /board Board dependent files
208 /common Misc architecture independent functions
209 /disk Code for disk drive partition handling
210 /doc Documentation (don't expect too much)
211 /drivers Commonly used device drivers
212 /dts Contains Makefile for building internal U-Boot fdt.
213 /examples Example code for standalone applications, etc.
214 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
215 /include Header Files
216 /lib Files generic to all architectures
217 /libfdt Library files to support flattened device trees
218 /lzma Library files to support LZMA decompression
219 /lzo Library files to support LZO decompression
221 /post Power On Self Test
222 /spl Secondary Program Loader framework
223 /tools Tools to build S-Record or U-Boot images, etc.
225 Software Configuration:
226 =======================
228 Configuration is usually done using C preprocessor defines; the
229 rationale behind that is to avoid dead code whenever possible.
231 There are two classes of configuration variables:
233 * Configuration _OPTIONS_:
234 These are selectable by the user and have names beginning with
237 * Configuration _SETTINGS_:
238 These depend on the hardware etc. and should not be meddled with if
239 you don't know what you're doing; they have names beginning with
242 Later we will add a configuration tool - probably similar to or even
243 identical to what's used for the Linux kernel. Right now, we have to
244 do the configuration by hand, which means creating some symbolic
245 links and editing some configuration files. We use the TQM8xxL boards
249 Selection of Processor Architecture and Board Type:
250 ---------------------------------------------------
252 For all supported boards there are ready-to-use default
253 configurations available; just type "make <board_name>_defconfig".
255 Example: For a TQM823L module type:
258 make TQM823L_defconfig
260 For the Cogent platform, you need to specify the CPU type as well;
261 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
262 directory according to the instructions in cogent/README.
268 U-Boot can be built natively to run on a Linux host using the 'sandbox'
269 board. This allows feature development which is not board- or architecture-
270 specific to be undertaken on a native platform. The sandbox is also used to
271 run some of U-Boot's tests.
273 See board/sandbox/README.sandbox for more details.
276 Configuration Options:
277 ----------------------
279 Configuration depends on the combination of board and CPU type; all
280 such information is kept in a configuration file
281 "include/configs/<board_name>.h".
283 Example: For a TQM823L module, all configuration settings are in
284 "include/configs/TQM823L.h".
287 Many of the options are named exactly as the corresponding Linux
288 kernel configuration options. The intention is to make it easier to
289 build a config tool - later.
292 The following options need to be configured:
294 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
296 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
298 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
299 Define exactly one, e.g. CONFIG_ATSTK1002
301 - CPU Module Type: (if CONFIG_COGENT is defined)
302 Define exactly one of
304 --- FIXME --- not tested yet:
305 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
306 CONFIG_CMA287_23, CONFIG_CMA287_50
308 - Motherboard Type: (if CONFIG_COGENT is defined)
309 Define exactly one of
310 CONFIG_CMA101, CONFIG_CMA102
312 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
313 Define one or more of
316 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
317 Define one or more of
318 CONFIG_LCD_HEARTBEAT - update a character position on
319 the LCD display every second with
322 - Marvell Family Member
323 CONFIG_SYS_MVFS - define it if you want to enable
324 multiple fs option at one time
325 for marvell soc family
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 required during NOR boot.
406 CONFIG_A008044_WORKAROUND
407 Enables a workaround for T1040/T1042 erratum A008044. It is only
408 required during NAND boot and valid for Rev 1.0 SoC revision
410 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
412 This is the value to write into CCSR offset 0x18600
413 according to the A004510 workaround.
415 CONFIG_SYS_FSL_DSP_DDR_ADDR
416 This value denotes start offset of DDR memory which is
417 connected exclusively to the DSP cores.
419 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
420 This value denotes start offset of M2 memory
421 which is directly connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
424 This value denotes start offset of M3 memory which is directly
425 connected to the DSP core.
427 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
428 This value denotes start offset of DSP CCSR space.
430 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
431 Single Source Clock is clocking mode present in some of FSL SoC's.
432 In this mode, a single differential clock is used to supply
433 clocks to the sysclock, ddrclock and usbclock.
435 CONFIG_SYS_CPC_REINIT_F
436 This CONFIG is defined when the CPC is configured as SRAM at the
437 time of U-boot entry and is required to be re-initialized.
440 Indicates this SoC supports deep sleep feature. If deep sleep is
441 supported, core will start to execute uboot when wakes up.
443 - Generic CPU options:
444 CONFIG_SYS_GENERIC_GLOBAL_DATA
445 Defines global data is initialized in generic board board_init_f().
446 If this macro is defined, global data is created and cleared in
447 generic board board_init_f(). Without this macro, architecture/board
448 should initialize global data before calling board_init_f().
450 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
452 Defines the endianess of the CPU. Implementation of those
453 values is arch specific.
456 Freescale DDR driver in use. This type of DDR controller is
457 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
460 CONFIG_SYS_FSL_DDR_ADDR
461 Freescale DDR memory-mapped register base.
463 CONFIG_SYS_FSL_DDR_EMU
464 Specify emulator support for DDR. Some DDR features such as
465 deskew training are not available.
467 CONFIG_SYS_FSL_DDRC_GEN1
468 Freescale DDR1 controller.
470 CONFIG_SYS_FSL_DDRC_GEN2
471 Freescale DDR2 controller.
473 CONFIG_SYS_FSL_DDRC_GEN3
474 Freescale DDR3 controller.
476 CONFIG_SYS_FSL_DDRC_GEN4
477 Freescale DDR4 controller.
479 CONFIG_SYS_FSL_DDRC_ARM_GEN3
480 Freescale DDR3 controller for ARM-based SoCs.
483 Board config to use DDR1. It can be enabled for SoCs with
484 Freescale DDR1 or DDR2 controllers, depending on the board
488 Board config to use DDR2. It can be eanbeld for SoCs with
489 Freescale DDR2 or DDR3 controllers, depending on the board
493 Board config to use DDR3. It can be enabled for SoCs with
494 Freescale DDR3 or DDR3L controllers.
497 Board config to use DDR3L. It can be enabled for SoCs with
501 Board config to use DDR4. It can be enabled for SoCs with
504 CONFIG_SYS_FSL_IFC_BE
505 Defines the IFC controller register space as Big Endian
507 CONFIG_SYS_FSL_IFC_LE
508 Defines the IFC controller register space as Little Endian
510 CONFIG_SYS_FSL_PBL_PBI
511 It enables addition of RCW (Power on reset configuration) in built image.
512 Please refer doc/README.pblimage for more details
514 CONFIG_SYS_FSL_PBL_RCW
515 It adds PBI(pre-boot instructions) commands in u-boot build image.
516 PBI commands can be used to configure SoC before it starts the execution.
517 Please refer doc/README.pblimage for more details
520 It adds a target to create boot binary having SPL binary in PBI format
521 concatenated with u-boot binary.
523 CONFIG_SYS_FSL_DDR_BE
524 Defines the DDR controller register space as Big Endian
526 CONFIG_SYS_FSL_DDR_LE
527 Defines the DDR controller register space as Little Endian
529 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
530 Physical address from the view of DDR controllers. It is the
531 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
532 it could be different for ARM SoCs.
534 CONFIG_SYS_FSL_DDR_INTLV_256B
535 DDR controller interleaving on 256-byte. This is a special
536 interleaving mode, handled by Dickens for Freescale layerscape
539 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
540 Number of controllers used as main memory.
542 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
543 Number of controllers used for other than main memory.
545 CONFIG_SYS_FSL_SEC_BE
546 Defines the SEC controller register space as Big Endian
548 CONFIG_SYS_FSL_SEC_LE
549 Defines the SEC controller register space as Little Endian
551 - Intel Monahans options:
552 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
554 Defines the Monahans run mode to oscillator
555 ratio. Valid values are 8, 16, 24, 31. The core
556 frequency is this value multiplied by 13 MHz.
558 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
560 Defines the Monahans turbo mode to oscillator
561 ratio. Valid values are 1 (default if undefined) and
562 2. The core frequency as calculated above is multiplied
566 CONFIG_SYS_INIT_SP_OFFSET
568 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
569 pointer. This is needed for the temporary stack before
572 CONFIG_SYS_MIPS_CACHE_MODE
574 Cache operation mode for the MIPS CPU.
575 See also arch/mips/include/asm/mipsregs.h.
577 CONF_CM_CACHABLE_NO_WA
580 CONF_CM_CACHABLE_NONCOHERENT
584 CONF_CM_CACHABLE_ACCELERATED
586 CONFIG_SYS_XWAY_EBU_BOOTCFG
588 Special option for Lantiq XWAY SoCs for booting from NOR flash.
589 See also arch/mips/cpu/mips32/start.S.
591 CONFIG_XWAY_SWAP_BYTES
593 Enable compilation of tools/xway-swap-bytes needed for Lantiq
594 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
595 be swapped if a flash programmer is used.
598 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
600 Select high exception vectors of the ARM core, e.g., do not
601 clear the V bit of the c1 register of CP15.
603 CONFIG_SYS_THUMB_BUILD
605 Use this flag to build U-Boot using the Thumb instruction
606 set for ARM architectures. Thumb instruction set provides
607 better code density. For ARM architectures that support
608 Thumb2 this flag will result in Thumb2 code generated by
611 CONFIG_ARM_ERRATA_716044
612 CONFIG_ARM_ERRATA_742230
613 CONFIG_ARM_ERRATA_743622
614 CONFIG_ARM_ERRATA_751472
615 CONFIG_ARM_ERRATA_794072
616 CONFIG_ARM_ERRATA_761320
618 If set, the workarounds for these ARM errata are applied early
619 during U-Boot startup. Note that these options force the
620 workarounds to be applied; no CPU-type/version detection
621 exists, unlike the similar options in the Linux kernel. Do not
622 set these options unless they apply!
625 Driver model is a new framework for devices in U-Boot
626 introduced in early 2014. U-Boot is being progressively
627 moved over to this. It offers a consistent device structure,
628 supports grouping devices into classes and has built-in
629 handling of platform data and device tree.
631 To enable transition to driver model in a relatively
632 painful fashion, each subsystem can be independently
633 switched between the legacy/ad-hoc approach and the new
634 driver model using the options below. Also, many uclass
635 interfaces include compatibility features which may be
636 removed once the conversion of that subsystem is complete.
637 As a result, the API provided by the subsystem may in fact
638 not change with driver model.
640 See doc/driver-model/README.txt for more information.
644 Enable driver model. This brings in the core support,
645 including scanning of platform data on start-up. If
646 CONFIG_OF_CONTROL is enabled, the device tree will be
647 scanned also when available.
651 Enable driver model test commands. These allow you to print
652 out the driver model tree and the uclasses.
656 Enable some demo devices and the 'demo' command. These are
657 really only useful for playing around while trying to
658 understand driver model in sandbox.
662 Enable driver model in SPL. You will need to provide a
663 suitable malloc() implementation. If you are not using the
664 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
665 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
666 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
667 In most cases driver model will only allocate a few uclasses
668 and devices in SPL, so 1KB should be enable. See
669 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
674 Enable driver model for serial. This replaces
675 drivers/serial/serial.c with the serial uclass, which
676 implements serial_putc() etc. The uclass interface is
677 defined in include/serial.h.
681 Enable driver model for GPIO access. The standard GPIO
682 interface (gpio_get_value(), etc.) is then implemented by
683 the GPIO uclass. Drivers provide methods to query the
684 particular GPIOs that they provide. The uclass interface
685 is defined in include/asm-generic/gpio.h.
689 Enable driver model for SPI. The SPI slave interface
690 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
691 the SPI uclass. Drivers provide methods to access the SPI
692 buses that they control. The uclass interface is defined in
693 include/spi.h. The existing spi_slave structure is attached
694 as 'parent data' to every slave on each bus. Slaves
695 typically use driver-private data instead of extending the
700 Enable driver model for SPI flash. This SPI flash interface
701 (spi_flash_probe(), spi_flash_write(), etc.) is then
702 implemented by the SPI flash uclass. There is one standard
703 SPI flash driver which knows how to probe most chips
704 supported by U-Boot. The uclass interface is defined in
705 include/spi_flash.h, but is currently fully compatible
706 with the old interface to avoid confusion and duplication
707 during the transition parent. SPI and SPI flash must be
708 enabled together (it is not possible to use driver model
709 for one and not the other).
713 Enable driver model for the Chrome OS EC interface. This
714 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
715 but otherwise makes few changes. Since cros_ec also supports
716 I2C and LPC (which don't support driver model yet), a full
717 conversion is not yet possible.
720 ** Code size options: The following options are enabled by
721 default except in SPL. Enable them explicitly to get these
726 Enable the dm_warn() function. This can use up quite a bit
727 of space for its strings.
731 Enable registering a serial device with the stdio library.
733 CONFIG_DM_DEVICE_REMOVE
735 Enable removing of devices.
738 - Linux Kernel Interface:
741 U-Boot stores all clock information in Hz
742 internally. For binary compatibility with older Linux
743 kernels (which expect the clocks passed in the
744 bd_info data to be in MHz) the environment variable
745 "clocks_in_mhz" can be defined so that U-Boot
746 converts clock data to MHZ before passing it to the
748 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
749 "clocks_in_mhz=1" is automatically included in the
752 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
754 When transferring memsize parameter to Linux, some versions
755 expect it to be in bytes, others in MB.
756 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
760 New kernel versions are expecting firmware settings to be
761 passed using flattened device trees (based on open firmware
765 * New libfdt-based support
766 * Adds the "fdt" command
767 * The bootm command automatically updates the fdt
769 OF_CPU - The proper name of the cpus node (only required for
770 MPC512X and MPC5xxx based boards).
771 OF_SOC - The proper name of the soc node (only required for
772 MPC512X and MPC5xxx based boards).
773 OF_TBCLK - The timebase frequency.
774 OF_STDOUT_PATH - The path to the console device
776 boards with QUICC Engines require OF_QE to set UCC MAC
779 CONFIG_OF_BOARD_SETUP
781 Board code has addition modification that it wants to make
782 to the flat device tree before handing it off to the kernel
784 CONFIG_OF_SYSTEM_SETUP
786 Other code has addition modification that it wants to make
787 to the flat device tree before handing it off to the kernel.
788 This causes ft_system_setup() to be called before booting
793 This define fills in the correct boot CPU in the boot
794 param header, the default value is zero if undefined.
798 U-Boot can detect if an IDE device is present or not.
799 If not, and this new config option is activated, U-Boot
800 removes the ATA node from the DTS before booting Linux,
801 so the Linux IDE driver does not probe the device and
802 crash. This is needed for buggy hardware (uc101) where
803 no pull down resistor is connected to the signal IDE5V_DD7.
805 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
807 This setting is mandatory for all boards that have only one
808 machine type and must be used to specify the machine type
809 number as it appears in the ARM machine registry
810 (see http://www.arm.linux.org.uk/developer/machines/).
811 Only boards that have multiple machine types supported
812 in a single configuration file and the machine type is
813 runtime discoverable, do not have to use this setting.
815 - vxWorks boot parameters:
817 bootvx constructs a valid bootline using the following
818 environments variables: bootfile, ipaddr, serverip, hostname.
819 It loads the vxWorks image pointed bootfile.
821 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
822 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
823 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
824 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
826 CONFIG_SYS_VXWORKS_ADD_PARAMS
828 Add it at the end of the bootline. E.g "u=username pw=secret"
830 Note: If a "bootargs" environment is defined, it will overwride
831 the defaults discussed just above.
833 - Cache Configuration:
834 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
835 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
836 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
838 - Cache Configuration for ARM:
839 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
841 CONFIG_SYS_PL310_BASE - Physical base address of PL310
842 controller register space
847 Define this if you want support for Amba PrimeCell PL010 UARTs.
851 Define this if you want support for Amba PrimeCell PL011 UARTs.
855 If you have Amba PrimeCell PL011 UARTs, set this variable to
856 the clock speed of the UARTs.
860 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
861 define this to a list of base addresses for each (supported)
862 port. See e.g. include/configs/versatile.h
864 CONFIG_PL011_SERIAL_RLCR
866 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
867 have separate receive and transmit line control registers. Set
868 this variable to initialize the extra register.
870 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
872 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
873 boot loader that has already initialized the UART. Define this
874 variable to flush the UART at init time.
876 CONFIG_SERIAL_HW_FLOW_CONTROL
878 Define this variable to enable hw flow control in serial driver.
879 Current user of this option is drivers/serial/nsl16550.c driver
882 Depending on board, define exactly one serial port
883 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
884 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
885 console by defining CONFIG_8xx_CONS_NONE
887 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
888 port routines must be defined elsewhere
889 (i.e. serial_init(), serial_getc(), ...)
892 Enables console device for a color framebuffer. Needs following
893 defines (cf. smiLynxEM, i8042)
894 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
896 VIDEO_HW_RECTFILL graphic chip supports
899 VIDEO_HW_BITBLT graphic chip supports
900 bit-blit (cf. smiLynxEM)
901 VIDEO_VISIBLE_COLS visible pixel columns
903 VIDEO_VISIBLE_ROWS visible pixel rows
904 VIDEO_PIXEL_SIZE bytes per pixel
905 VIDEO_DATA_FORMAT graphic data format
906 (0-5, cf. cfb_console.c)
907 VIDEO_FB_ADRS framebuffer address
908 VIDEO_KBD_INIT_FCT keyboard int fct
909 (i.e. i8042_kbd_init())
910 VIDEO_TSTC_FCT test char fct
912 VIDEO_GETC_FCT get char fct
914 CONFIG_CONSOLE_CURSOR cursor drawing on/off
915 (requires blink timer
917 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
918 CONFIG_CONSOLE_TIME display time/date info in
920 (requires CONFIG_CMD_DATE)
921 CONFIG_VIDEO_LOGO display Linux logo in
923 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
924 linux_logo.h for logo.
925 Requires CONFIG_VIDEO_LOGO
926 CONFIG_CONSOLE_EXTRA_INFO
927 additional board info beside
930 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
931 a limited number of ANSI escape sequences (cursor control,
932 erase functions and limited graphics rendition control).
934 When CONFIG_CFB_CONSOLE is defined, video console is
935 default i/o. Serial console can be forced with
936 environment 'console=serial'.
938 When CONFIG_SILENT_CONSOLE is defined, all console
939 messages (by U-Boot and Linux!) can be silenced with
940 the "silent" environment variable. See
941 doc/README.silent for more information.
943 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
945 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
949 CONFIG_BAUDRATE - in bps
950 Select one of the baudrates listed in
951 CONFIG_SYS_BAUDRATE_TABLE, see below.
952 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
954 - Console Rx buffer length
955 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
956 the maximum receive buffer length for the SMC.
957 This option is actual only for 82xx and 8xx possible.
958 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
959 must be defined, to setup the maximum idle timeout for
962 - Pre-Console Buffer:
963 Prior to the console being initialised (i.e. serial UART
964 initialised etc) all console output is silently discarded.
965 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
966 buffer any console messages prior to the console being
967 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
968 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
969 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
970 bytes are output before the console is initialised, the
971 earlier bytes are discarded.
973 'Sane' compilers will generate smaller code if
974 CONFIG_PRE_CON_BUF_SZ is a power of 2
976 - Safe printf() functions
977 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
978 the printf() functions. These are defined in
979 include/vsprintf.h and include snprintf(), vsnprintf() and
980 so on. Code size increase is approximately 300-500 bytes.
981 If this option is not given then these functions will
982 silently discard their buffer size argument - this means
983 you are not getting any overflow checking in this case.
985 - Boot Delay: CONFIG_BOOTDELAY - in seconds
986 Delay before automatically booting the default image;
987 set to -1 to disable autoboot.
988 set to -2 to autoboot with no delay and not check for abort
989 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
991 See doc/README.autoboot for these options that
992 work with CONFIG_BOOTDELAY. None are required.
993 CONFIG_BOOT_RETRY_TIME
994 CONFIG_BOOT_RETRY_MIN
995 CONFIG_AUTOBOOT_KEYED
996 CONFIG_AUTOBOOT_PROMPT
997 CONFIG_AUTOBOOT_DELAY_STR
998 CONFIG_AUTOBOOT_STOP_STR
999 CONFIG_AUTOBOOT_DELAY_STR2
1000 CONFIG_AUTOBOOT_STOP_STR2
1001 CONFIG_ZERO_BOOTDELAY_CHECK
1002 CONFIG_RESET_TO_RETRY
1006 Only needed when CONFIG_BOOTDELAY is enabled;
1007 define a command string that is automatically executed
1008 when no character is read on the console interface
1009 within "Boot Delay" after reset.
1012 This can be used to pass arguments to the bootm
1013 command. The value of CONFIG_BOOTARGS goes into the
1014 environment value "bootargs".
1016 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1017 The value of these goes into the environment as
1018 "ramboot" and "nfsboot" respectively, and can be used
1019 as a convenience, when switching between booting from
1023 CONFIG_BOOTCOUNT_LIMIT
1024 Implements a mechanism for detecting a repeating reboot
1026 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1028 CONFIG_BOOTCOUNT_ENV
1029 If no softreset save registers are found on the hardware
1030 "bootcount" is stored in the environment. To prevent a
1031 saveenv on all reboots, the environment variable
1032 "upgrade_available" is used. If "upgrade_available" is
1033 0, "bootcount" is always 0, if "upgrade_available" is
1034 1 "bootcount" is incremented in the environment.
1035 So the Userspace Applikation must set the "upgrade_available"
1036 and "bootcount" variable to 0, if a boot was successfully.
1038 - Pre-Boot Commands:
1041 When this option is #defined, the existence of the
1042 environment variable "preboot" will be checked
1043 immediately before starting the CONFIG_BOOTDELAY
1044 countdown and/or running the auto-boot command resp.
1045 entering interactive mode.
1047 This feature is especially useful when "preboot" is
1048 automatically generated or modified. For an example
1049 see the LWMON board specific code: here "preboot" is
1050 modified when the user holds down a certain
1051 combination of keys on the (special) keyboard when
1054 - Serial Download Echo Mode:
1056 If defined to 1, all characters received during a
1057 serial download (using the "loads" command) are
1058 echoed back. This might be needed by some terminal
1059 emulations (like "cu"), but may as well just take
1060 time on others. This setting #define's the initial
1061 value of the "loads_echo" environment variable.
1063 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1064 CONFIG_KGDB_BAUDRATE
1065 Select one of the baudrates listed in
1066 CONFIG_SYS_BAUDRATE_TABLE, see below.
1068 - Monitor Functions:
1069 Monitor commands can be included or excluded
1070 from the build by using the #include files
1071 <config_cmd_all.h> and #undef'ing unwanted
1072 commands, or using <config_cmd_default.h>
1073 and augmenting with additional #define's
1074 for wanted commands.
1076 The default command configuration includes all commands
1077 except those marked below with a "*".
1079 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1080 CONFIG_CMD_ASKENV * ask for env variable
1081 CONFIG_CMD_BDI bdinfo
1082 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1083 CONFIG_CMD_BMP * BMP support
1084 CONFIG_CMD_BSP * Board specific commands
1085 CONFIG_CMD_BOOTD bootd
1086 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1087 CONFIG_CMD_CACHE * icache, dcache
1088 CONFIG_CMD_CLK * clock command support
1089 CONFIG_CMD_CONSOLE coninfo
1090 CONFIG_CMD_CRC32 * crc32
1091 CONFIG_CMD_DATE * support for RTC, date/time...
1092 CONFIG_CMD_DHCP * DHCP support
1093 CONFIG_CMD_DIAG * Diagnostics
1094 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1095 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1096 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1097 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1098 CONFIG_CMD_DTT * Digital Therm and Thermostat
1099 CONFIG_CMD_ECHO echo arguments
1100 CONFIG_CMD_EDITENV edit env variable
1101 CONFIG_CMD_EEPROM * EEPROM read/write support
1102 CONFIG_CMD_ELF * bootelf, bootvx
1103 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1104 CONFIG_CMD_ENV_FLAGS * display details about env flags
1105 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1106 CONFIG_CMD_EXPORTENV * export the environment
1107 CONFIG_CMD_EXT2 * ext2 command support
1108 CONFIG_CMD_EXT4 * ext4 command support
1109 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1110 that work for multiple fs types
1111 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1112 CONFIG_CMD_SAVEENV saveenv
1113 CONFIG_CMD_FDC * Floppy Disk Support
1114 CONFIG_CMD_FAT * FAT command support
1115 CONFIG_CMD_FLASH flinfo, erase, protect
1116 CONFIG_CMD_FPGA FPGA device initialization support
1117 CONFIG_CMD_FUSE * Device fuse support
1118 CONFIG_CMD_GETTIME * Get time since boot
1119 CONFIG_CMD_GO * the 'go' command (exec code)
1120 CONFIG_CMD_GREPENV * search environment
1121 CONFIG_CMD_HASH * calculate hash / digest
1122 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1123 CONFIG_CMD_I2C * I2C serial bus support
1124 CONFIG_CMD_IDE * IDE harddisk support
1125 CONFIG_CMD_IMI iminfo
1126 CONFIG_CMD_IMLS List all images found in NOR flash
1127 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1128 CONFIG_CMD_IMMAP * IMMR dump support
1129 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1130 CONFIG_CMD_IMPORTENV * import an environment
1131 CONFIG_CMD_INI * import data from an ini file into the env
1132 CONFIG_CMD_IRQ * irqinfo
1133 CONFIG_CMD_ITEST Integer/string test of 2 values
1134 CONFIG_CMD_JFFS2 * JFFS2 Support
1135 CONFIG_CMD_KGDB * kgdb
1136 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1137 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1139 CONFIG_CMD_LOADB loadb
1140 CONFIG_CMD_LOADS loads
1141 CONFIG_CMD_MD5SUM * print md5 message digest
1142 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1143 CONFIG_CMD_MEMINFO * Display detailed memory information
1144 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1146 CONFIG_CMD_MEMTEST * mtest
1147 CONFIG_CMD_MISC Misc functions like sleep etc
1148 CONFIG_CMD_MMC * MMC memory mapped support
1149 CONFIG_CMD_MII * MII utility commands
1150 CONFIG_CMD_MTDPARTS * MTD partition support
1151 CONFIG_CMD_NAND * NAND support
1152 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1153 CONFIG_CMD_NFS NFS support
1154 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1155 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1156 CONFIG_CMD_PCI * pciinfo
1157 CONFIG_CMD_PCMCIA * PCMCIA support
1158 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1160 CONFIG_CMD_PORTIO * Port I/O
1161 CONFIG_CMD_READ * Read raw data from partition
1162 CONFIG_CMD_REGINFO * Register dump
1163 CONFIG_CMD_RUN run command in env variable
1164 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1165 CONFIG_CMD_SAVES * save S record dump
1166 CONFIG_CMD_SCSI * SCSI Support
1167 CONFIG_CMD_SDRAM * print SDRAM configuration information
1168 (requires CONFIG_CMD_I2C)
1169 CONFIG_CMD_SETGETDCR Support for DCR Register access
1171 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1172 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1173 (requires CONFIG_CMD_MEMORY)
1174 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1175 CONFIG_CMD_SOURCE "source" command Support
1176 CONFIG_CMD_SPI * SPI serial bus support
1177 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1178 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1179 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1180 CONFIG_CMD_TIMER * access to the system tick timer
1181 CONFIG_CMD_USB * USB support
1182 CONFIG_CMD_CDP * Cisco Discover Protocol support
1183 CONFIG_CMD_MFSL * Microblaze FSL support
1184 CONFIG_CMD_XIMG Load part of Multi Image
1185 CONFIG_CMD_UUID * Generate random UUID or GUID string
1187 EXAMPLE: If you want all functions except of network
1188 support you can write:
1190 #include "config_cmd_all.h"
1191 #undef CONFIG_CMD_NET
1194 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1196 Note: Don't enable the "icache" and "dcache" commands
1197 (configuration option CONFIG_CMD_CACHE) unless you know
1198 what you (and your U-Boot users) are doing. Data
1199 cache cannot be enabled on systems like the 8xx or
1200 8260 (where accesses to the IMMR region must be
1201 uncached), and it cannot be disabled on all other
1202 systems where we (mis-) use the data cache to hold an
1203 initial stack and some data.
1206 XXX - this list needs to get updated!
1208 - Regular expression support:
1210 If this variable is defined, U-Boot is linked against
1211 the SLRE (Super Light Regular Expression) library,
1212 which adds regex support to some commands, as for
1213 example "env grep" and "setexpr".
1217 If this variable is defined, U-Boot will use a device tree
1218 to configure its devices, instead of relying on statically
1219 compiled #defines in the board file. This option is
1220 experimental and only available on a few boards. The device
1221 tree is available in the global data as gd->fdt_blob.
1223 U-Boot needs to get its device tree from somewhere. This can
1224 be done using one of the two options below:
1227 If this variable is defined, U-Boot will embed a device tree
1228 binary in its image. This device tree file should be in the
1229 board directory and called <soc>-<board>.dts. The binary file
1230 is then picked up in board_init_f() and made available through
1231 the global data structure as gd->blob.
1234 If this variable is defined, U-Boot will build a device tree
1235 binary. It will be called u-boot.dtb. Architecture-specific
1236 code will locate it at run-time. Generally this works by:
1238 cat u-boot.bin u-boot.dtb >image.bin
1240 and in fact, U-Boot does this for you, creating a file called
1241 u-boot-dtb.bin which is useful in the common case. You can
1242 still use the individual files if you need something more
1247 If this variable is defined, it enables watchdog
1248 support for the SoC. There must be support in the SoC
1249 specific code for a watchdog. For the 8xx and 8260
1250 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1251 register. When supported for a specific SoC is
1252 available, then no further board specific code should
1253 be needed to use it.
1256 When using a watchdog circuitry external to the used
1257 SoC, then define this variable and provide board
1258 specific code for the "hw_watchdog_reset" function.
1260 CONFIG_AT91_HW_WDT_TIMEOUT
1261 specify the timeout in seconds. default 2 seconds.
1264 CONFIG_VERSION_VARIABLE
1265 If this variable is defined, an environment variable
1266 named "ver" is created by U-Boot showing the U-Boot
1267 version as printed by the "version" command.
1268 Any change to this variable will be reverted at the
1273 When CONFIG_CMD_DATE is selected, the type of the RTC
1274 has to be selected, too. Define exactly one of the
1277 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1278 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1279 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1280 CONFIG_RTC_MC146818 - use MC146818 RTC
1281 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1282 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1283 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1284 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1285 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1286 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1287 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1288 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1289 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1292 Note that if the RTC uses I2C, then the I2C interface
1293 must also be configured. See I2C Support, below.
1296 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1298 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1299 chip-ngpio pairs that tell the PCA953X driver the number of
1300 pins supported by a particular chip.
1302 Note that if the GPIO device uses I2C, then the I2C interface
1303 must also be configured. See I2C Support, below.
1306 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1307 accesses and can checksum them or write a list of them out
1308 to memory. See the 'iotrace' command for details. This is
1309 useful for testing device drivers since it can confirm that
1310 the driver behaves the same way before and after a code
1311 change. Currently this is supported on sandbox and arm. To
1312 add support for your architecture, add '#include <iotrace.h>'
1313 to the bottom of arch/<arch>/include/asm/io.h and test.
1315 Example output from the 'iotrace stats' command is below.
1316 Note that if the trace buffer is exhausted, the checksum will
1317 still continue to operate.
1320 Start: 10000000 (buffer start address)
1321 Size: 00010000 (buffer size)
1322 Offset: 00000120 (current buffer offset)
1323 Output: 10000120 (start + offset)
1324 Count: 00000018 (number of trace records)
1325 CRC32: 9526fb66 (CRC32 of all trace records)
1327 - Timestamp Support:
1329 When CONFIG_TIMESTAMP is selected, the timestamp
1330 (date and time) of an image is printed by image
1331 commands like bootm or iminfo. This option is
1332 automatically enabled when you select CONFIG_CMD_DATE .
1334 - Partition Labels (disklabels) Supported:
1335 Zero or more of the following:
1336 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1337 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1338 Intel architecture, USB sticks, etc.
1339 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1340 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1341 bootloader. Note 2TB partition limit; see
1343 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1345 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1346 CONFIG_CMD_SCSI) you must configure support for at
1347 least one non-MTD partition type as well.
1350 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1351 board configurations files but used nowhere!
1353 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1354 be performed by calling the function
1355 ide_set_reset(int reset)
1356 which has to be defined in a board specific file
1361 Set this to enable ATAPI support.
1366 Set this to enable support for disks larger than 137GB
1367 Also look at CONFIG_SYS_64BIT_LBA.
1368 Whithout these , LBA48 support uses 32bit variables and will 'only'
1369 support disks up to 2.1TB.
1371 CONFIG_SYS_64BIT_LBA:
1372 When enabled, makes the IDE subsystem use 64bit sector addresses.
1376 At the moment only there is only support for the
1377 SYM53C8XX SCSI controller; define
1378 CONFIG_SCSI_SYM53C8XX to enable it.
1380 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1381 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1382 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1383 maximum numbers of LUNs, SCSI ID's and target
1385 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1387 The environment variable 'scsidevs' is set to the number of
1388 SCSI devices found during the last scan.
1390 - NETWORK Support (PCI):
1392 Support for Intel 8254x/8257x gigabit chips.
1395 Utility code for direct access to the SPI bus on Intel 8257x.
1396 This does not do anything useful unless you set at least one
1397 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1399 CONFIG_E1000_SPI_GENERIC
1400 Allow generic access to the SPI bus on the Intel 8257x, for
1401 example with the "sspi" command.
1404 Management command for E1000 devices. When used on devices
1405 with SPI support you can reprogram the EEPROM from U-Boot.
1407 CONFIG_E1000_FALLBACK_MAC
1408 default MAC for empty EEPROM after production.
1411 Support for Intel 82557/82559/82559ER chips.
1412 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1413 write routine for first time initialisation.
1416 Support for Digital 2114x chips.
1417 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1418 modem chip initialisation (KS8761/QS6611).
1421 Support for National dp83815 chips.
1424 Support for National dp8382[01] gigabit chips.
1426 - NETWORK Support (other):
1428 CONFIG_DRIVER_AT91EMAC
1429 Support for AT91RM9200 EMAC.
1432 Define this to use reduced MII inteface
1434 CONFIG_DRIVER_AT91EMAC_QUIET
1435 If this defined, the driver is quiet.
1436 The driver doen't show link status messages.
1438 CONFIG_CALXEDA_XGMAC
1439 Support for the Calxeda XGMAC device
1442 Support for SMSC's LAN91C96 chips.
1444 CONFIG_LAN91C96_BASE
1445 Define this to hold the physical address
1446 of the LAN91C96's I/O space
1448 CONFIG_LAN91C96_USE_32_BIT
1449 Define this to enable 32 bit addressing
1452 Support for SMSC's LAN91C111 chip
1454 CONFIG_SMC91111_BASE
1455 Define this to hold the physical address
1456 of the device (I/O space)
1458 CONFIG_SMC_USE_32_BIT
1459 Define this if data bus is 32 bits
1461 CONFIG_SMC_USE_IOFUNCS
1462 Define this to use i/o functions instead of macros
1463 (some hardware wont work with macros)
1465 CONFIG_DRIVER_TI_EMAC
1466 Support for davinci emac
1468 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1469 Define this if you have more then 3 PHYs.
1472 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1474 CONFIG_FTGMAC100_EGIGA
1475 Define this to use GE link update with gigabit PHY.
1476 Define this if FTGMAC100 is connected to gigabit PHY.
1477 If your system has 10/100 PHY only, it might not occur
1478 wrong behavior. Because PHY usually return timeout or
1479 useless data when polling gigabit status and gigabit
1480 control registers. This behavior won't affect the
1481 correctnessof 10/100 link speed update.
1484 Support for SMSC's LAN911x and LAN921x chips
1487 Define this to hold the physical address
1488 of the device (I/O space)
1490 CONFIG_SMC911X_32_BIT
1491 Define this if data bus is 32 bits
1493 CONFIG_SMC911X_16_BIT
1494 Define this if data bus is 16 bits. If your processor
1495 automatically converts one 32 bit word to two 16 bit
1496 words you may also try CONFIG_SMC911X_32_BIT.
1499 Support for Renesas on-chip Ethernet controller
1501 CONFIG_SH_ETHER_USE_PORT
1502 Define the number of ports to be used
1504 CONFIG_SH_ETHER_PHY_ADDR
1505 Define the ETH PHY's address
1507 CONFIG_SH_ETHER_CACHE_WRITEBACK
1508 If this option is set, the driver enables cache flush.
1512 Support for PWM modul on the imx6.
1516 Support TPM devices.
1519 Support for i2c bus TPM devices. Only one device
1520 per system is supported at this time.
1522 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1523 Define the the i2c bus number for the TPM device
1525 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1526 Define the TPM's address on the i2c bus
1528 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1529 Define the burst count bytes upper limit
1531 CONFIG_TPM_ATMEL_TWI
1532 Support for Atmel TWI TPM device. Requires I2C support.
1535 Support for generic parallel port TPM devices. Only one device
1536 per system is supported at this time.
1538 CONFIG_TPM_TIS_BASE_ADDRESS
1539 Base address where the generic TPM device is mapped
1540 to. Contemporary x86 systems usually map it at
1544 Add tpm monitor functions.
1545 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1546 provides monitor access to authorized functions.
1549 Define this to enable the TPM support library which provides
1550 functional interfaces to some TPM commands.
1551 Requires support for a TPM device.
1553 CONFIG_TPM_AUTH_SESSIONS
1554 Define this to enable authorized functions in the TPM library.
1555 Requires CONFIG_TPM and CONFIG_SHA1.
1558 At the moment only the UHCI host controller is
1559 supported (PIP405, MIP405, MPC5200); define
1560 CONFIG_USB_UHCI to enable it.
1561 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1562 and define CONFIG_USB_STORAGE to enable the USB
1565 Supported are USB Keyboards and USB Floppy drives
1567 MPC5200 USB requires additional defines:
1569 for 528 MHz Clock: 0x0001bbbb
1573 for differential drivers: 0x00001000
1574 for single ended drivers: 0x00005000
1575 for differential drivers on PSC3: 0x00000100
1576 for single ended drivers on PSC3: 0x00004100
1577 CONFIG_SYS_USB_EVENT_POLL
1578 May be defined to allow interrupt polling
1579 instead of using asynchronous interrupts
1581 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1582 txfilltuning field in the EHCI controller on reset.
1584 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1585 HW module registers.
1588 Define the below if you wish to use the USB console.
1589 Once firmware is rebuilt from a serial console issue the
1590 command "setenv stdin usbtty; setenv stdout usbtty" and
1591 attach your USB cable. The Unix command "dmesg" should print
1592 it has found a new device. The environment variable usbtty
1593 can be set to gserial or cdc_acm to enable your device to
1594 appear to a USB host as a Linux gserial device or a
1595 Common Device Class Abstract Control Model serial device.
1596 If you select usbtty = gserial you should be able to enumerate
1598 # modprobe usbserial vendor=0xVendorID product=0xProductID
1599 else if using cdc_acm, simply setting the environment
1600 variable usbtty to be cdc_acm should suffice. The following
1601 might be defined in YourBoardName.h
1604 Define this to build a UDC device
1607 Define this to have a tty type of device available to
1608 talk to the UDC device
1611 Define this to enable the high speed support for usb
1612 device and usbtty. If this feature is enabled, a routine
1613 int is_usbd_high_speed(void)
1614 also needs to be defined by the driver to dynamically poll
1615 whether the enumeration has succeded at high speed or full
1618 CONFIG_SYS_CONSOLE_IS_IN_ENV
1619 Define this if you want stdin, stdout &/or stderr to
1623 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1624 Derive USB clock from external clock "blah"
1625 - CONFIG_SYS_USB_EXTC_CLK 0x02
1627 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1628 Derive USB clock from brgclk
1629 - CONFIG_SYS_USB_BRG_CLK 0x04
1631 If you have a USB-IF assigned VendorID then you may wish to
1632 define your own vendor specific values either in BoardName.h
1633 or directly in usbd_vendor_info.h. If you don't define
1634 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1635 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1636 should pretend to be a Linux device to it's target host.
1638 CONFIG_USBD_MANUFACTURER
1639 Define this string as the name of your company for
1640 - CONFIG_USBD_MANUFACTURER "my company"
1642 CONFIG_USBD_PRODUCT_NAME
1643 Define this string as the name of your product
1644 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1646 CONFIG_USBD_VENDORID
1647 Define this as your assigned Vendor ID from the USB
1648 Implementors Forum. This *must* be a genuine Vendor ID
1649 to avoid polluting the USB namespace.
1650 - CONFIG_USBD_VENDORID 0xFFFF
1652 CONFIG_USBD_PRODUCTID
1653 Define this as the unique Product ID
1655 - CONFIG_USBD_PRODUCTID 0xFFFF
1657 - ULPI Layer Support:
1658 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1659 the generic ULPI layer. The generic layer accesses the ULPI PHY
1660 via the platform viewport, so you need both the genric layer and
1661 the viewport enabled. Currently only Chipidea/ARC based
1662 viewport is supported.
1663 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1664 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1665 If your ULPI phy needs a different reference clock than the
1666 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1667 the appropriate value in Hz.
1670 The MMC controller on the Intel PXA is supported. To
1671 enable this define CONFIG_MMC. The MMC can be
1672 accessed from the boot prompt by mapping the device
1673 to physical memory similar to flash. Command line is
1674 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1675 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1678 Support for Renesas on-chip MMCIF controller
1680 CONFIG_SH_MMCIF_ADDR
1681 Define the base address of MMCIF registers
1684 Define the clock frequency for MMCIF
1687 Enable the generic MMC driver
1689 CONFIG_SUPPORT_EMMC_BOOT
1690 Enable some additional features of the eMMC boot partitions.
1692 CONFIG_SUPPORT_EMMC_RPMB
1693 Enable the commands for reading, writing and programming the
1694 key for the Replay Protection Memory Block partition in eMMC.
1696 - USB Device Firmware Update (DFU) class support:
1698 This enables the USB portion of the DFU USB class
1701 This enables the command "dfu" which is used to have
1702 U-Boot create a DFU class device via USB. This command
1703 requires that the "dfu_alt_info" environment variable be
1704 set and define the alt settings to expose to the host.
1707 This enables support for exposing (e)MMC devices via DFU.
1710 This enables support for exposing NAND devices via DFU.
1713 This enables support for exposing RAM via DFU.
1714 Note: DFU spec refer to non-volatile memory usage, but
1715 allow usages beyond the scope of spec - here RAM usage,
1716 one that would help mostly the developer.
1718 CONFIG_SYS_DFU_DATA_BUF_SIZE
1719 Dfu transfer uses a buffer before writing data to the
1720 raw storage device. Make the size (in bytes) of this buffer
1721 configurable. The size of this buffer is also configurable
1722 through the "dfu_bufsiz" environment variable.
1724 CONFIG_SYS_DFU_MAX_FILE_SIZE
1725 When updating files rather than the raw storage device,
1726 we use a static buffer to copy the file into and then write
1727 the buffer once we've been given the whole file. Define
1728 this to the maximum filesize (in bytes) for the buffer.
1729 Default is 4 MiB if undefined.
1731 DFU_DEFAULT_POLL_TIMEOUT
1732 Poll timeout [ms], is the timeout a device can send to the
1733 host. The host must wait for this timeout before sending
1734 a subsequent DFU_GET_STATUS request to the device.
1736 DFU_MANIFEST_POLL_TIMEOUT
1737 Poll timeout [ms], which the device sends to the host when
1738 entering dfuMANIFEST state. Host waits this timeout, before
1739 sending again an USB request to the device.
1741 - USB Device Android Fastboot support:
1743 This enables the command "fastboot" which enables the Android
1744 fastboot mode for the platform's USB device. Fastboot is a USB
1745 protocol for downloading images, flashing and device control
1746 used on Android devices.
1747 See doc/README.android-fastboot for more information.
1749 CONFIG_ANDROID_BOOT_IMAGE
1750 This enables support for booting images which use the Android
1751 image format header.
1753 CONFIG_USB_FASTBOOT_BUF_ADDR
1754 The fastboot protocol requires a large memory buffer for
1755 downloads. Define this to the starting RAM address to use for
1758 CONFIG_USB_FASTBOOT_BUF_SIZE
1759 The fastboot protocol requires a large memory buffer for
1760 downloads. This buffer should be as large as possible for a
1761 platform. Define this to the size available RAM for fastboot.
1763 CONFIG_FASTBOOT_FLASH
1764 The fastboot protocol includes a "flash" command for writing
1765 the downloaded image to a non-volatile storage device. Define
1766 this to enable the "fastboot flash" command.
1768 CONFIG_FASTBOOT_FLASH_MMC_DEV
1769 The fastboot "flash" command requires additional information
1770 regarding the non-volatile storage device. Define this to
1771 the eMMC device that fastboot should use to store the image.
1773 CONFIG_FASTBOOT_GPT_NAME
1774 The fastboot "flash" command supports writing the downloaded
1775 image to the Protective MBR and the Primary GUID Partition
1776 Table. (Additionally, this downloaded image is post-processed
1777 to generate and write the Backup GUID Partition Table.)
1778 This occurs when the specified "partition name" on the
1779 "fastboot flash" command line matches this value.
1780 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1782 - Journaling Flash filesystem support:
1783 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1784 CONFIG_JFFS2_NAND_DEV
1785 Define these for a default partition on a NAND device
1787 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1788 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1789 Define these for a default partition on a NOR device
1791 CONFIG_SYS_JFFS_CUSTOM_PART
1792 Define this to create an own partition. You have to provide a
1793 function struct part_info* jffs2_part_info(int part_num)
1795 If you define only one JFFS2 partition you may also want to
1796 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1797 to disable the command chpart. This is the default when you
1798 have not defined a custom partition
1800 - FAT(File Allocation Table) filesystem write function support:
1803 Define this to enable support for saving memory data as a
1804 file in FAT formatted partition.
1806 This will also enable the command "fatwrite" enabling the
1807 user to write files to FAT.
1809 CBFS (Coreboot Filesystem) support
1812 Define this to enable support for reading from a Coreboot
1813 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1816 - FAT(File Allocation Table) filesystem cluster size:
1817 CONFIG_FS_FAT_MAX_CLUSTSIZE
1819 Define the max cluster size for fat operations else
1820 a default value of 65536 will be defined.
1825 Define this to enable standard (PC-Style) keyboard
1829 Standard PC keyboard driver with US (is default) and
1830 GERMAN key layout (switch via environment 'keymap=de') support.
1831 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1832 for cfb_console. Supports cursor blinking.
1835 Enables a Chrome OS keyboard using the CROS_EC interface.
1836 This uses CROS_EC to communicate with a second microcontroller
1837 which provides key scans on request.
1842 Define this to enable video support (for output to
1845 CONFIG_VIDEO_CT69000
1847 Enable Chips & Technologies 69000 Video chip
1849 CONFIG_VIDEO_SMI_LYNXEM
1850 Enable Silicon Motion SMI 712/710/810 Video chip. The
1851 video output is selected via environment 'videoout'
1852 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1855 For the CT69000 and SMI_LYNXEM drivers, videomode is
1856 selected via environment 'videomode'. Two different ways
1858 - "videomode=num" 'num' is a standard LiLo mode numbers.
1859 Following standard modes are supported (* is default):
1861 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1862 -------------+---------------------------------------------
1863 8 bits | 0x301* 0x303 0x305 0x161 0x307
1864 15 bits | 0x310 0x313 0x316 0x162 0x319
1865 16 bits | 0x311 0x314 0x317 0x163 0x31A
1866 24 bits | 0x312 0x315 0x318 ? 0x31B
1867 -------------+---------------------------------------------
1868 (i.e. setenv videomode 317; saveenv; reset;)
1870 - "videomode=bootargs" all the video parameters are parsed
1871 from the bootargs. (See drivers/video/videomodes.c)
1874 CONFIG_VIDEO_SED13806
1875 Enable Epson SED13806 driver. This driver supports 8bpp
1876 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1877 or CONFIG_VIDEO_SED13806_16BPP
1880 Enable the Freescale DIU video driver. Reference boards for
1881 SOCs that have a DIU should define this macro to enable DIU
1882 support, and should also define these other macros:
1888 CONFIG_VIDEO_SW_CURSOR
1889 CONFIG_VGA_AS_SINGLE_DEVICE
1891 CONFIG_VIDEO_BMP_LOGO
1893 The DIU driver will look for the 'video-mode' environment
1894 variable, and if defined, enable the DIU as a console during
1895 boot. See the documentation file README.video for a
1896 description of this variable.
1900 Enable the VGA video / BIOS for x86. The alternative if you
1901 are using coreboot is to use the coreboot frame buffer
1908 Define this to enable a custom keyboard support.
1909 This simply calls drv_keyboard_init() which must be
1910 defined in your board-specific files.
1911 The only board using this so far is RBC823.
1913 - LCD Support: CONFIG_LCD
1915 Define this to enable LCD support (for output to LCD
1916 display); also select one of the supported displays
1917 by defining one of these:
1921 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1923 CONFIG_NEC_NL6448AC33:
1925 NEC NL6448AC33-18. Active, color, single scan.
1927 CONFIG_NEC_NL6448BC20
1929 NEC NL6448BC20-08. 6.5", 640x480.
1930 Active, color, single scan.
1932 CONFIG_NEC_NL6448BC33_54
1934 NEC NL6448BC33-54. 10.4", 640x480.
1935 Active, color, single scan.
1939 Sharp 320x240. Active, color, single scan.
1940 It isn't 16x9, and I am not sure what it is.
1942 CONFIG_SHARP_LQ64D341
1944 Sharp LQ64D341 display, 640x480.
1945 Active, color, single scan.
1949 HLD1045 display, 640x480.
1950 Active, color, single scan.
1954 Optrex CBL50840-2 NF-FW 99 22 M5
1956 Hitachi LMG6912RPFC-00T
1960 320x240. Black & white.
1962 Normally display is black on white background; define
1963 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1965 CONFIG_LCD_ALIGNMENT
1967 Normally the LCD is page-aligned (typically 4KB). If this is
1968 defined then the LCD will be aligned to this value instead.
1969 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1970 here, since it is cheaper to change data cache settings on
1971 a per-section basis.
1973 CONFIG_CONSOLE_SCROLL_LINES
1975 When the console need to be scrolled, this is the number of
1976 lines to scroll by. It defaults to 1. Increasing this makes
1977 the console jump but can help speed up operation when scrolling
1982 Support drawing of RLE8-compressed bitmaps on the LCD.
1986 Enables an 'i2c edid' command which can read EDID
1987 information over I2C from an attached LCD display.
1989 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1991 If this option is set, the environment is checked for
1992 a variable "splashimage". If found, the usual display
1993 of logo, copyright and system information on the LCD
1994 is suppressed and the BMP image at the address
1995 specified in "splashimage" is loaded instead. The
1996 console is redirected to the "nulldev", too. This
1997 allows for a "silent" boot where a splash screen is
1998 loaded very quickly after power-on.
2000 CONFIG_SPLASHIMAGE_GUARD
2002 If this option is set, then U-Boot will prevent the environment
2003 variable "splashimage" from being set to a problematic address
2004 (see README.displaying-bmps).
2005 This option is useful for targets where, due to alignment
2006 restrictions, an improperly aligned BMP image will cause a data
2007 abort. If you think you will not have problems with unaligned
2008 accesses (for example because your toolchain prevents them)
2009 there is no need to set this option.
2011 CONFIG_SPLASH_SCREEN_ALIGN
2013 If this option is set the splash image can be freely positioned
2014 on the screen. Environment variable "splashpos" specifies the
2015 position as "x,y". If a positive number is given it is used as
2016 number of pixel from left/top. If a negative number is given it
2017 is used as number of pixel from right/bottom. You can also
2018 specify 'm' for centering the image.
2021 setenv splashpos m,m
2022 => image at center of screen
2024 setenv splashpos 30,20
2025 => image at x = 30 and y = 20
2027 setenv splashpos -10,m
2028 => vertically centered image
2029 at x = dspWidth - bmpWidth - 9
2031 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2033 If this option is set, additionally to standard BMP
2034 images, gzipped BMP images can be displayed via the
2035 splashscreen support or the bmp command.
2037 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2039 If this option is set, 8-bit RLE compressed BMP images
2040 can be displayed via the splashscreen support or the
2043 - Do compressing for memory range:
2046 If this option is set, it would use zlib deflate method
2047 to compress the specified memory at its best effort.
2049 - Compression support:
2052 Enabled by default to support gzip compressed images.
2056 If this option is set, support for bzip2 compressed
2057 images is included. If not, only uncompressed and gzip
2058 compressed images are supported.
2060 NOTE: the bzip2 algorithm requires a lot of RAM, so
2061 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2066 If this option is set, support for lzma compressed
2069 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2070 requires an amount of dynamic memory that is given by the
2073 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2075 Where lc and lp stand for, respectively, Literal context bits
2076 and Literal pos bits.
2078 This value is upper-bounded by 14MB in the worst case. Anyway,
2079 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2080 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2081 a very small buffer.
2083 Use the lzmainfo tool to determinate the lc and lp values and
2084 then calculate the amount of needed dynamic memory (ensuring
2085 the appropriate CONFIG_SYS_MALLOC_LEN value).
2089 If this option is set, support for LZO compressed images
2095 The address of PHY on MII bus.
2097 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2099 The clock frequency of the MII bus
2103 If this option is set, support for speed/duplex
2104 detection of gigabit PHY is included.
2106 CONFIG_PHY_RESET_DELAY
2108 Some PHY like Intel LXT971A need extra delay after
2109 reset before any MII register access is possible.
2110 For such PHY, set this option to the usec delay
2111 required. (minimum 300usec for LXT971A)
2113 CONFIG_PHY_CMD_DELAY (ppc4xx)
2115 Some PHY like Intel LXT971A need extra delay after
2116 command issued before MII status register can be read
2126 Define a default value for Ethernet address to use
2127 for the respective Ethernet interface, in case this
2128 is not determined automatically.
2133 Define a default value for the IP address to use for
2134 the default Ethernet interface, in case this is not
2135 determined through e.g. bootp.
2136 (Environment variable "ipaddr")
2138 - Server IP address:
2141 Defines a default value for the IP address of a TFTP
2142 server to contact when using the "tftboot" command.
2143 (Environment variable "serverip")
2145 CONFIG_KEEP_SERVERADDR
2147 Keeps the server's MAC address, in the env 'serveraddr'
2148 for passing to bootargs (like Linux's netconsole option)
2150 - Gateway IP address:
2153 Defines a default value for the IP address of the
2154 default router where packets to other networks are
2156 (Environment variable "gatewayip")
2161 Defines a default value for the subnet mask (or
2162 routing prefix) which is used to determine if an IP
2163 address belongs to the local subnet or needs to be
2164 forwarded through a router.
2165 (Environment variable "netmask")
2167 - Multicast TFTP Mode:
2170 Defines whether you want to support multicast TFTP as per
2171 rfc-2090; for example to work with atftp. Lets lots of targets
2172 tftp down the same boot image concurrently. Note: the Ethernet
2173 driver in use must provide a function: mcast() to join/leave a
2176 - BOOTP Recovery Mode:
2177 CONFIG_BOOTP_RANDOM_DELAY
2179 If you have many targets in a network that try to
2180 boot using BOOTP, you may want to avoid that all
2181 systems send out BOOTP requests at precisely the same
2182 moment (which would happen for instance at recovery
2183 from a power failure, when all systems will try to
2184 boot, thus flooding the BOOTP server. Defining
2185 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2186 inserted before sending out BOOTP requests. The
2187 following delays are inserted then:
2189 1st BOOTP request: delay 0 ... 1 sec
2190 2nd BOOTP request: delay 0 ... 2 sec
2191 3rd BOOTP request: delay 0 ... 4 sec
2193 BOOTP requests: delay 0 ... 8 sec
2195 CONFIG_BOOTP_ID_CACHE_SIZE
2197 BOOTP packets are uniquely identified using a 32-bit ID. The
2198 server will copy the ID from client requests to responses and
2199 U-Boot will use this to determine if it is the destination of
2200 an incoming response. Some servers will check that addresses
2201 aren't in use before handing them out (usually using an ARP
2202 ping) and therefore take up to a few hundred milliseconds to
2203 respond. Network congestion may also influence the time it
2204 takes for a response to make it back to the client. If that
2205 time is too long, U-Boot will retransmit requests. In order
2206 to allow earlier responses to still be accepted after these
2207 retransmissions, U-Boot's BOOTP client keeps a small cache of
2208 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2209 cache. The default is to keep IDs for up to four outstanding
2210 requests. Increasing this will allow U-Boot to accept offers
2211 from a BOOTP client in networks with unusually high latency.
2213 - BOOTP Random transaction ID:
2214 CONFIG_BOOTP_RANDOM_ID
2216 The standard algorithm to generate a DHCP/BOOTP transaction ID
2217 by using the MAC address and the current time stamp may not
2218 quite unlikely produce duplicate transaction IDs from different
2219 clients in the same network. This option creates a transaction
2220 ID using the rand() function. Provided that the RNG has been
2221 seeded well, this should guarantee unique transaction IDs
2224 - DHCP Advanced Options:
2225 You can fine tune the DHCP functionality by defining
2226 CONFIG_BOOTP_* symbols:
2228 CONFIG_BOOTP_SUBNETMASK
2229 CONFIG_BOOTP_GATEWAY
2230 CONFIG_BOOTP_HOSTNAME
2231 CONFIG_BOOTP_NISDOMAIN
2232 CONFIG_BOOTP_BOOTPATH
2233 CONFIG_BOOTP_BOOTFILESIZE
2236 CONFIG_BOOTP_SEND_HOSTNAME
2237 CONFIG_BOOTP_NTPSERVER
2238 CONFIG_BOOTP_TIMEOFFSET
2239 CONFIG_BOOTP_VENDOREX
2240 CONFIG_BOOTP_MAY_FAIL
2242 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2243 environment variable, not the BOOTP server.
2245 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2246 after the configured retry count, the call will fail
2247 instead of starting over. This can be used to fail over
2248 to Link-local IP address configuration if the DHCP server
2251 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2252 serverip from a DHCP server, it is possible that more
2253 than one DNS serverip is offered to the client.
2254 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2255 serverip will be stored in the additional environment
2256 variable "dnsip2". The first DNS serverip is always
2257 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2260 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2261 to do a dynamic update of a DNS server. To do this, they
2262 need the hostname of the DHCP requester.
2263 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2264 of the "hostname" environment variable is passed as
2265 option 12 to the DHCP server.
2267 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2269 A 32bit value in microseconds for a delay between
2270 receiving a "DHCP Offer" and sending the "DHCP Request".
2271 This fixes a problem with certain DHCP servers that don't
2272 respond 100% of the time to a "DHCP request". E.g. On an
2273 AT91RM9200 processor running at 180MHz, this delay needed
2274 to be *at least* 15,000 usec before a Windows Server 2003
2275 DHCP server would reply 100% of the time. I recommend at
2276 least 50,000 usec to be safe. The alternative is to hope
2277 that one of the retries will be successful but note that
2278 the DHCP timeout and retry process takes a longer than
2281 - Link-local IP address negotiation:
2282 Negotiate with other link-local clients on the local network
2283 for an address that doesn't require explicit configuration.
2284 This is especially useful if a DHCP server cannot be guaranteed
2285 to exist in all environments that the device must operate.
2287 See doc/README.link-local for more information.
2290 CONFIG_CDP_DEVICE_ID
2292 The device id used in CDP trigger frames.
2294 CONFIG_CDP_DEVICE_ID_PREFIX
2296 A two character string which is prefixed to the MAC address
2301 A printf format string which contains the ascii name of
2302 the port. Normally is set to "eth%d" which sets
2303 eth0 for the first Ethernet, eth1 for the second etc.
2305 CONFIG_CDP_CAPABILITIES
2307 A 32bit integer which indicates the device capabilities;
2308 0x00000010 for a normal host which does not forwards.
2312 An ascii string containing the version of the software.
2316 An ascii string containing the name of the platform.
2320 A 32bit integer sent on the trigger.
2322 CONFIG_CDP_POWER_CONSUMPTION
2324 A 16bit integer containing the power consumption of the
2325 device in .1 of milliwatts.
2327 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2329 A byte containing the id of the VLAN.
2331 - Status LED: CONFIG_STATUS_LED
2333 Several configurations allow to display the current
2334 status using a LED. For instance, the LED will blink
2335 fast while running U-Boot code, stop blinking as
2336 soon as a reply to a BOOTP request was received, and
2337 start blinking slow once the Linux kernel is running
2338 (supported by a status LED driver in the Linux
2339 kernel). Defining CONFIG_STATUS_LED enables this
2345 The status LED can be connected to a GPIO pin.
2346 In such cases, the gpio_led driver can be used as a
2347 status LED backend implementation. Define CONFIG_GPIO_LED
2348 to include the gpio_led driver in the U-Boot binary.
2350 CONFIG_GPIO_LED_INVERTED_TABLE
2351 Some GPIO connected LEDs may have inverted polarity in which
2352 case the GPIO high value corresponds to LED off state and
2353 GPIO low value corresponds to LED on state.
2354 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2355 with a list of GPIO LEDs that have inverted polarity.
2357 - CAN Support: CONFIG_CAN_DRIVER
2359 Defining CONFIG_CAN_DRIVER enables CAN driver support
2360 on those systems that support this (optional)
2361 feature, like the TQM8xxL modules.
2363 - I2C Support: CONFIG_SYS_I2C
2365 This enable the NEW i2c subsystem, and will allow you to use
2366 i2c commands at the u-boot command line (as long as you set
2367 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2368 based realtime clock chips or other i2c devices. See
2369 common/cmd_i2c.c for a description of the command line
2372 ported i2c driver to the new framework:
2373 - drivers/i2c/soft_i2c.c:
2374 - activate first bus with CONFIG_SYS_I2C_SOFT define
2375 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2376 for defining speed and slave address
2377 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2378 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2379 for defining speed and slave address
2380 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2381 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2382 for defining speed and slave address
2383 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2384 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2385 for defining speed and slave address
2387 - drivers/i2c/fsl_i2c.c:
2388 - activate i2c driver with CONFIG_SYS_I2C_FSL
2389 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2390 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2391 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2393 - If your board supports a second fsl i2c bus, define
2394 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2395 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2396 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2399 - drivers/i2c/tegra_i2c.c:
2400 - activate this driver with CONFIG_SYS_I2C_TEGRA
2401 - This driver adds 4 i2c buses with a fix speed from
2402 100000 and the slave addr 0!
2404 - drivers/i2c/ppc4xx_i2c.c
2405 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2406 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2407 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2409 - drivers/i2c/i2c_mxc.c
2410 - activate this driver with CONFIG_SYS_I2C_MXC
2411 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2412 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2413 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2414 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2415 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2416 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2417 If those defines are not set, default value is 100000
2418 for speed, and 0 for slave.
2420 - drivers/i2c/rcar_i2c.c:
2421 - activate this driver with CONFIG_SYS_I2C_RCAR
2422 - This driver adds 4 i2c buses
2424 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2425 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2426 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2427 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2428 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2429 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2430 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2431 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2432 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2434 - drivers/i2c/sh_i2c.c:
2435 - activate this driver with CONFIG_SYS_I2C_SH
2436 - This driver adds from 2 to 5 i2c buses
2438 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2439 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2440 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2441 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2442 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2443 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2444 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2445 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2446 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2447 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2448 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2449 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2450 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2452 - drivers/i2c/omap24xx_i2c.c
2453 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2454 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2455 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2456 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2457 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2458 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2459 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2460 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2461 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2462 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2463 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2465 - drivers/i2c/zynq_i2c.c
2466 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2467 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2468 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2470 - drivers/i2c/s3c24x0_i2c.c:
2471 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2472 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2473 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2474 with a fix speed from 100000 and the slave addr 0!
2476 - drivers/i2c/ihs_i2c.c
2477 - activate this driver with CONFIG_SYS_I2C_IHS
2478 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2479 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2480 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2481 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2482 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2483 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2484 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2485 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2486 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2487 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2488 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2489 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2493 CONFIG_SYS_NUM_I2C_BUSES
2494 Hold the number of i2c buses you want to use. If you
2495 don't use/have i2c muxes on your i2c bus, this
2496 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2499 CONFIG_SYS_I2C_DIRECT_BUS
2500 define this, if you don't use i2c muxes on your hardware.
2501 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2504 CONFIG_SYS_I2C_MAX_HOPS
2505 define how many muxes are maximal consecutively connected
2506 on one i2c bus. If you not use i2c muxes, omit this
2509 CONFIG_SYS_I2C_BUSES
2510 hold a list of buses you want to use, only used if
2511 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2512 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2513 CONFIG_SYS_NUM_I2C_BUSES = 9:
2515 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2516 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2517 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2518 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2519 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2520 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2521 {1, {I2C_NULL_HOP}}, \
2522 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2523 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2527 bus 0 on adapter 0 without a mux
2528 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2529 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2530 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2531 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2532 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2533 bus 6 on adapter 1 without a mux
2534 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2535 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2537 If you do not have i2c muxes on your board, omit this define.
2539 - Legacy I2C Support: CONFIG_HARD_I2C
2541 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2542 provides the following compelling advantages:
2544 - more than one i2c adapter is usable
2545 - approved multibus support
2546 - better i2c mux support
2548 ** Please consider updating your I2C driver now. **
2550 These enable legacy I2C serial bus commands. Defining
2551 CONFIG_HARD_I2C will include the appropriate I2C driver
2552 for the selected CPU.
2554 This will allow you to use i2c commands at the u-boot
2555 command line (as long as you set CONFIG_CMD_I2C in
2556 CONFIG_COMMANDS) and communicate with i2c based realtime
2557 clock chips. See common/cmd_i2c.c for a description of the
2558 command line interface.
2560 CONFIG_HARD_I2C selects a hardware I2C controller.
2562 There are several other quantities that must also be
2563 defined when you define CONFIG_HARD_I2C.
2565 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2566 to be the frequency (in Hz) at which you wish your i2c bus
2567 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2568 the CPU's i2c node address).
2570 Now, the u-boot i2c code for the mpc8xx
2571 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2572 and so its address should therefore be cleared to 0 (See,
2573 eg, MPC823e User's Manual p.16-473). So, set
2574 CONFIG_SYS_I2C_SLAVE to 0.
2576 CONFIG_SYS_I2C_INIT_MPC5XXX
2578 When a board is reset during an i2c bus transfer
2579 chips might think that the current transfer is still
2580 in progress. Reset the slave devices by sending start
2581 commands until the slave device responds.
2583 That's all that's required for CONFIG_HARD_I2C.
2585 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2586 then the following macros need to be defined (examples are
2587 from include/configs/lwmon.h):
2591 (Optional). Any commands necessary to enable the I2C
2592 controller or configure ports.
2594 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2598 (Only for MPC8260 CPU). The I/O port to use (the code
2599 assumes both bits are on the same port). Valid values
2600 are 0..3 for ports A..D.
2604 The code necessary to make the I2C data line active
2605 (driven). If the data line is open collector, this
2608 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2612 The code necessary to make the I2C data line tri-stated
2613 (inactive). If the data line is open collector, this
2616 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2620 Code that returns true if the I2C data line is high,
2623 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2627 If <bit> is true, sets the I2C data line high. If it
2628 is false, it clears it (low).
2630 eg: #define I2C_SDA(bit) \
2631 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2632 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2636 If <bit> is true, sets the I2C clock line high. If it
2637 is false, it clears it (low).
2639 eg: #define I2C_SCL(bit) \
2640 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2641 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2645 This delay is invoked four times per clock cycle so this
2646 controls the rate of data transfer. The data rate thus
2647 is 1 / (I2C_DELAY * 4). Often defined to be something
2650 #define I2C_DELAY udelay(2)
2652 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2654 If your arch supports the generic GPIO framework (asm/gpio.h),
2655 then you may alternatively define the two GPIOs that are to be
2656 used as SCL / SDA. Any of the previous I2C_xxx macros will
2657 have GPIO-based defaults assigned to them as appropriate.
2659 You should define these to the GPIO value as given directly to
2660 the generic GPIO functions.
2662 CONFIG_SYS_I2C_INIT_BOARD
2664 When a board is reset during an i2c bus transfer
2665 chips might think that the current transfer is still
2666 in progress. On some boards it is possible to access
2667 the i2c SCLK line directly, either by using the
2668 processor pin as a GPIO or by having a second pin
2669 connected to the bus. If this option is defined a
2670 custom i2c_init_board() routine in boards/xxx/board.c
2671 is run early in the boot sequence.
2673 CONFIG_SYS_I2C_BOARD_LATE_INIT
2675 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2676 defined a custom i2c_board_late_init() routine in
2677 boards/xxx/board.c is run AFTER the operations in i2c_init()
2678 is completed. This callpoint can be used to unreset i2c bus
2679 using CPU i2c controller register accesses for CPUs whose i2c
2680 controller provide such a method. It is called at the end of
2681 i2c_init() to allow i2c_init operations to setup the i2c bus
2682 controller on the CPU (e.g. setting bus speed & slave address).
2684 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2686 This option enables configuration of bi_iic_fast[] flags
2687 in u-boot bd_info structure based on u-boot environment
2688 variable "i2cfast". (see also i2cfast)
2690 CONFIG_I2C_MULTI_BUS
2692 This option allows the use of multiple I2C buses, each of which
2693 must have a controller. At any point in time, only one bus is
2694 active. To switch to a different bus, use the 'i2c dev' command.
2695 Note that bus numbering is zero-based.
2697 CONFIG_SYS_I2C_NOPROBES
2699 This option specifies a list of I2C devices that will be skipped
2700 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2701 is set, specify a list of bus-device pairs. Otherwise, specify
2702 a 1D array of device addresses
2705 #undef CONFIG_I2C_MULTI_BUS
2706 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2708 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2710 #define CONFIG_I2C_MULTI_BUS
2711 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2713 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2715 CONFIG_SYS_SPD_BUS_NUM
2717 If defined, then this indicates the I2C bus number for DDR SPD.
2718 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2720 CONFIG_SYS_RTC_BUS_NUM
2722 If defined, then this indicates the I2C bus number for the RTC.
2723 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2725 CONFIG_SYS_DTT_BUS_NUM
2727 If defined, then this indicates the I2C bus number for the DTT.
2728 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2730 CONFIG_SYS_I2C_DTT_ADDR:
2732 If defined, specifies the I2C address of the DTT device.
2733 If not defined, then U-Boot uses predefined value for
2734 specified DTT device.
2736 CONFIG_SOFT_I2C_READ_REPEATED_START
2738 defining this will force the i2c_read() function in
2739 the soft_i2c driver to perform an I2C repeated start
2740 between writing the address pointer and reading the
2741 data. If this define is omitted the default behaviour
2742 of doing a stop-start sequence will be used. Most I2C
2743 devices can use either method, but some require one or
2746 - SPI Support: CONFIG_SPI
2748 Enables SPI driver (so far only tested with
2749 SPI EEPROM, also an instance works with Crystal A/D and
2750 D/As on the SACSng board)
2754 Enables the driver for SPI controller on SuperH. Currently
2755 only SH7757 is supported.
2759 Enables extended (16-bit) SPI EEPROM addressing.
2760 (symmetrical to CONFIG_I2C_X)
2764 Enables a software (bit-bang) SPI driver rather than
2765 using hardware support. This is a general purpose
2766 driver that only requires three general I/O port pins
2767 (two outputs, one input) to function. If this is
2768 defined, the board configuration must define several
2769 SPI configuration items (port pins to use, etc). For
2770 an example, see include/configs/sacsng.h.
2774 Enables a hardware SPI driver for general-purpose reads
2775 and writes. As with CONFIG_SOFT_SPI, the board configuration
2776 must define a list of chip-select function pointers.
2777 Currently supported on some MPC8xxx processors. For an
2778 example, see include/configs/mpc8349emds.h.
2782 Enables the driver for the SPI controllers on i.MX and MXC
2783 SoCs. Currently i.MX31/35/51 are supported.
2785 CONFIG_SYS_SPI_MXC_WAIT
2786 Timeout for waiting until spi transfer completed.
2787 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2789 - FPGA Support: CONFIG_FPGA
2791 Enables FPGA subsystem.
2793 CONFIG_FPGA_<vendor>
2795 Enables support for specific chip vendors.
2798 CONFIG_FPGA_<family>
2800 Enables support for FPGA family.
2801 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2805 Specify the number of FPGA devices to support.
2807 CONFIG_CMD_FPGA_LOADMK
2809 Enable support for fpga loadmk command
2811 CONFIG_CMD_FPGA_LOADP
2813 Enable support for fpga loadp command - load partial bitstream
2815 CONFIG_CMD_FPGA_LOADBP
2817 Enable support for fpga loadbp command - load partial bitstream
2820 CONFIG_SYS_FPGA_PROG_FEEDBACK
2822 Enable printing of hash marks during FPGA configuration.
2824 CONFIG_SYS_FPGA_CHECK_BUSY
2826 Enable checks on FPGA configuration interface busy
2827 status by the configuration function. This option
2828 will require a board or device specific function to
2833 If defined, a function that provides delays in the FPGA
2834 configuration driver.
2836 CONFIG_SYS_FPGA_CHECK_CTRLC
2837 Allow Control-C to interrupt FPGA configuration
2839 CONFIG_SYS_FPGA_CHECK_ERROR
2841 Check for configuration errors during FPGA bitfile
2842 loading. For example, abort during Virtex II
2843 configuration if the INIT_B line goes low (which
2844 indicated a CRC error).
2846 CONFIG_SYS_FPGA_WAIT_INIT
2848 Maximum time to wait for the INIT_B line to de-assert
2849 after PROB_B has been de-asserted during a Virtex II
2850 FPGA configuration sequence. The default time is 500
2853 CONFIG_SYS_FPGA_WAIT_BUSY
2855 Maximum time to wait for BUSY to de-assert during
2856 Virtex II FPGA configuration. The default is 5 ms.
2858 CONFIG_SYS_FPGA_WAIT_CONFIG
2860 Time to wait after FPGA configuration. The default is
2863 - Configuration Management:
2866 Some SoCs need special image types (e.g. U-Boot binary
2867 with a special header) as build targets. By defining
2868 CONFIG_BUILD_TARGET in the SoC / board header, this
2869 special image will be automatically built upon calling
2874 If defined, this string will be added to the U-Boot
2875 version information (U_BOOT_VERSION)
2877 - Vendor Parameter Protection:
2879 U-Boot considers the values of the environment
2880 variables "serial#" (Board Serial Number) and
2881 "ethaddr" (Ethernet Address) to be parameters that
2882 are set once by the board vendor / manufacturer, and
2883 protects these variables from casual modification by
2884 the user. Once set, these variables are read-only,
2885 and write or delete attempts are rejected. You can
2886 change this behaviour:
2888 If CONFIG_ENV_OVERWRITE is #defined in your config
2889 file, the write protection for vendor parameters is
2890 completely disabled. Anybody can change or delete
2893 Alternatively, if you #define _both_ CONFIG_ETHADDR
2894 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2895 Ethernet address is installed in the environment,
2896 which can be changed exactly ONCE by the user. [The
2897 serial# is unaffected by this, i. e. it remains
2900 The same can be accomplished in a more flexible way
2901 for any variable by configuring the type of access
2902 to allow for those variables in the ".flags" variable
2903 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2908 Define this variable to enable the reservation of
2909 "protected RAM", i. e. RAM which is not overwritten
2910 by U-Boot. Define CONFIG_PRAM to hold the number of
2911 kB you want to reserve for pRAM. You can overwrite
2912 this default value by defining an environment
2913 variable "pram" to the number of kB you want to
2914 reserve. Note that the board info structure will
2915 still show the full amount of RAM. If pRAM is
2916 reserved, a new environment variable "mem" will
2917 automatically be defined to hold the amount of
2918 remaining RAM in a form that can be passed as boot
2919 argument to Linux, for instance like that:
2921 setenv bootargs ... mem=\${mem}
2924 This way you can tell Linux not to use this memory,
2925 either, which results in a memory region that will
2926 not be affected by reboots.
2928 *WARNING* If your board configuration uses automatic
2929 detection of the RAM size, you must make sure that
2930 this memory test is non-destructive. So far, the
2931 following board configurations are known to be
2934 IVMS8, IVML24, SPD8xx, TQM8xxL,
2935 HERMES, IP860, RPXlite, LWMON,
2938 - Access to physical memory region (> 4GB)
2939 Some basic support is provided for operations on memory not
2940 normally accessible to U-Boot - e.g. some architectures
2941 support access to more than 4GB of memory on 32-bit
2942 machines using physical address extension or similar.
2943 Define CONFIG_PHYSMEM to access this basic support, which
2944 currently only supports clearing the memory.
2949 Define this variable to stop the system in case of a
2950 fatal error, so that you have to reset it manually.
2951 This is probably NOT a good idea for an embedded
2952 system where you want the system to reboot
2953 automatically as fast as possible, but it may be
2954 useful during development since you can try to debug
2955 the conditions that lead to the situation.
2957 CONFIG_NET_RETRY_COUNT
2959 This variable defines the number of retries for
2960 network operations like ARP, RARP, TFTP, or BOOTP
2961 before giving up the operation. If not defined, a
2962 default value of 5 is used.
2966 Timeout waiting for an ARP reply in milliseconds.
2970 Timeout in milliseconds used in NFS protocol.
2971 If you encounter "ERROR: Cannot umount" in nfs command,
2972 try longer timeout such as
2973 #define CONFIG_NFS_TIMEOUT 10000UL
2975 - Command Interpreter:
2976 CONFIG_AUTO_COMPLETE
2978 Enable auto completion of commands using TAB.
2980 CONFIG_SYS_PROMPT_HUSH_PS2
2982 This defines the secondary prompt string, which is
2983 printed when the command interpreter needs more input
2984 to complete a command. Usually "> ".
2988 In the current implementation, the local variables
2989 space and global environment variables space are
2990 separated. Local variables are those you define by
2991 simply typing `name=value'. To access a local
2992 variable later on, you have write `$name' or
2993 `${name}'; to execute the contents of a variable
2994 directly type `$name' at the command prompt.
2996 Global environment variables are those you use
2997 setenv/printenv to work with. To run a command stored
2998 in such a variable, you need to use the run command,
2999 and you must not use the '$' sign to access them.
3001 To store commands and special characters in a
3002 variable, please use double quotation marks
3003 surrounding the whole text of the variable, instead
3004 of the backslashes before semicolons and special
3007 - Command Line Editing and History:
3008 CONFIG_CMDLINE_EDITING
3010 Enable editing and History functions for interactive
3011 command line input operations
3013 - Default Environment:
3014 CONFIG_EXTRA_ENV_SETTINGS
3016 Define this to contain any number of null terminated
3017 strings (variable = value pairs) that will be part of
3018 the default environment compiled into the boot image.
3020 For example, place something like this in your
3021 board's config file:
3023 #define CONFIG_EXTRA_ENV_SETTINGS \
3027 Warning: This method is based on knowledge about the
3028 internal format how the environment is stored by the
3029 U-Boot code. This is NOT an official, exported
3030 interface! Although it is unlikely that this format
3031 will change soon, there is no guarantee either.
3032 You better know what you are doing here.
3034 Note: overly (ab)use of the default environment is
3035 discouraged. Make sure to check other ways to preset
3036 the environment like the "source" command or the
3039 CONFIG_ENV_VARS_UBOOT_CONFIG
3041 Define this in order to add variables describing the
3042 U-Boot build configuration to the default environment.
3043 These will be named arch, cpu, board, vendor, and soc.
3045 Enabling this option will cause the following to be defined:
3053 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3055 Define this in order to add variables describing certain
3056 run-time determined information about the hardware to the
3057 environment. These will be named board_name, board_rev.
3059 CONFIG_DELAY_ENVIRONMENT
3061 Normally the environment is loaded when the board is
3062 initialised so that it is available to U-Boot. This inhibits
3063 that so that the environment is not available until
3064 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3065 this is instead controlled by the value of
3066 /config/load-environment.
3068 - DataFlash Support:
3069 CONFIG_HAS_DATAFLASH
3071 Defining this option enables DataFlash features and
3072 allows to read/write in Dataflash via the standard
3075 - Serial Flash support
3078 Defining this option enables SPI flash commands
3079 'sf probe/read/write/erase/update'.
3081 Usage requires an initial 'probe' to define the serial
3082 flash parameters, followed by read/write/erase/update
3085 The following defaults may be provided by the platform
3086 to handle the common case when only a single serial
3087 flash is present on the system.
3089 CONFIG_SF_DEFAULT_BUS Bus identifier
3090 CONFIG_SF_DEFAULT_CS Chip-select
3091 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3092 CONFIG_SF_DEFAULT_SPEED in Hz
3096 Define this option to include a destructive SPI flash
3099 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3101 Define this option to use the Bank addr/Extended addr
3102 support on SPI flashes which has size > 16Mbytes.
3104 CONFIG_SF_DUAL_FLASH Dual flash memories
3106 Define this option to use dual flash support where two flash
3107 memories can be connected with a given cs line.
3108 Currently Xilinx Zynq qspi supports these type of connections.
3110 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3111 enable the W#/Vpp signal to disable writing to the status
3112 register on ST MICRON flashes like the N25Q128.
3113 The status register write enable/disable bit, combined with
3114 the W#/VPP signal provides hardware data protection for the
3115 device as follows: When the enable/disable bit is set to 1,
3116 and the W#/VPP signal is driven LOW, the status register
3117 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3118 operation will not execute. The only way to exit this
3119 hardware-protected mode is to drive W#/VPP HIGH.
3121 - SystemACE Support:
3124 Adding this option adds support for Xilinx SystemACE
3125 chips attached via some sort of local bus. The address
3126 of the chip must also be defined in the
3127 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3129 #define CONFIG_SYSTEMACE
3130 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3132 When SystemACE support is added, the "ace" device type
3133 becomes available to the fat commands, i.e. fatls.
3135 - TFTP Fixed UDP Port:
3138 If this is defined, the environment variable tftpsrcp
3139 is used to supply the TFTP UDP source port value.
3140 If tftpsrcp isn't defined, the normal pseudo-random port
3141 number generator is used.
3143 Also, the environment variable tftpdstp is used to supply
3144 the TFTP UDP destination port value. If tftpdstp isn't
3145 defined, the normal port 69 is used.
3147 The purpose for tftpsrcp is to allow a TFTP server to
3148 blindly start the TFTP transfer using the pre-configured
3149 target IP address and UDP port. This has the effect of
3150 "punching through" the (Windows XP) firewall, allowing
3151 the remainder of the TFTP transfer to proceed normally.
3152 A better solution is to properly configure the firewall,
3153 but sometimes that is not allowed.
3158 This enables a generic 'hash' command which can produce
3159 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3163 Enable the hash verify command (hash -v). This adds to code
3166 CONFIG_SHA1 - support SHA1 hashing
3167 CONFIG_SHA256 - support SHA256 hashing
3169 Note: There is also a sha1sum command, which should perhaps
3170 be deprecated in favour of 'hash sha1'.
3172 - Freescale i.MX specific commands:
3173 CONFIG_CMD_HDMIDETECT
3174 This enables 'hdmidet' command which returns true if an
3175 HDMI monitor is detected. This command is i.MX 6 specific.
3178 This enables the 'bmode' (bootmode) command for forcing
3179 a boot from specific media.
3181 This is useful for forcing the ROM's usb downloader to
3182 activate upon a watchdog reset which is nice when iterating
3183 on U-Boot. Using the reset button or running bmode normal
3184 will set it back to normal. This command currently
3185 supports i.MX53 and i.MX6.
3190 This enables the RSA algorithm used for FIT image verification
3191 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3193 The Modular Exponentiation algorithm in RSA is implemented using
3194 driver model. So CONFIG_DM needs to be enabled by default for this
3195 library to function.
3197 The signing part is build into mkimage regardless of this
3198 option. The software based modular exponentiation is built into
3199 mkimage irrespective of this option.
3201 - bootcount support:
3202 CONFIG_BOOTCOUNT_LIMIT
3204 This enables the bootcounter support, see:
3205 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3208 enable special bootcounter support on at91sam9xe based boards.
3210 enable special bootcounter support on blackfin based boards.
3212 enable special bootcounter support on da850 based boards.
3213 CONFIG_BOOTCOUNT_RAM
3214 enable support for the bootcounter in RAM
3215 CONFIG_BOOTCOUNT_I2C
3216 enable support for the bootcounter on an i2c (like RTC) device.
3217 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3218 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3220 CONFIG_BOOTCOUNT_ALEN = address len
3222 - Show boot progress:
3223 CONFIG_SHOW_BOOT_PROGRESS
3225 Defining this option allows to add some board-
3226 specific code (calling a user-provided function
3227 "show_boot_progress(int)") that enables you to show
3228 the system's boot progress on some display (for
3229 example, some LED's) on your board. At the moment,
3230 the following checkpoints are implemented:
3232 - Detailed boot stage timing
3234 Define this option to get detailed timing of each stage
3235 of the boot process.
3237 CONFIG_BOOTSTAGE_USER_COUNT
3238 This is the number of available user bootstage records.
3239 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3240 a new ID will be allocated from this stash. If you exceed
3241 the limit, recording will stop.
3243 CONFIG_BOOTSTAGE_REPORT
3244 Define this to print a report before boot, similar to this:
3246 Timer summary in microseconds:
3249 3,575,678 3,575,678 board_init_f start
3250 3,575,695 17 arch_cpu_init A9
3251 3,575,777 82 arch_cpu_init done
3252 3,659,598 83,821 board_init_r start
3253 3,910,375 250,777 main_loop
3254 29,916,167 26,005,792 bootm_start
3255 30,361,327 445,160 start_kernel
3257 CONFIG_CMD_BOOTSTAGE
3258 Add a 'bootstage' command which supports printing a report
3259 and un/stashing of bootstage data.
3261 CONFIG_BOOTSTAGE_FDT
3262 Stash the bootstage information in the FDT. A root 'bootstage'
3263 node is created with each bootstage id as a child. Each child
3264 has a 'name' property and either 'mark' containing the
3265 mark time in microsecond, or 'accum' containing the
3266 accumulated time for that bootstage id in microseconds.
3271 name = "board_init_f";
3280 Code in the Linux kernel can find this in /proc/devicetree.
3282 Legacy uImage format:
3285 1 common/cmd_bootm.c before attempting to boot an image
3286 -1 common/cmd_bootm.c Image header has bad magic number
3287 2 common/cmd_bootm.c Image header has correct magic number
3288 -2 common/cmd_bootm.c Image header has bad checksum
3289 3 common/cmd_bootm.c Image header has correct checksum
3290 -3 common/cmd_bootm.c Image data has bad checksum
3291 4 common/cmd_bootm.c Image data has correct checksum
3292 -4 common/cmd_bootm.c Image is for unsupported architecture
3293 5 common/cmd_bootm.c Architecture check OK
3294 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3295 6 common/cmd_bootm.c Image Type check OK
3296 -6 common/cmd_bootm.c gunzip uncompression error
3297 -7 common/cmd_bootm.c Unimplemented compression type
3298 7 common/cmd_bootm.c Uncompression OK
3299 8 common/cmd_bootm.c No uncompress/copy overwrite error
3300 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3302 9 common/image.c Start initial ramdisk verification
3303 -10 common/image.c Ramdisk header has bad magic number
3304 -11 common/image.c Ramdisk header has bad checksum
3305 10 common/image.c Ramdisk header is OK
3306 -12 common/image.c Ramdisk data has bad checksum
3307 11 common/image.c Ramdisk data has correct checksum
3308 12 common/image.c Ramdisk verification complete, start loading
3309 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3310 13 common/image.c Start multifile image verification
3311 14 common/image.c No initial ramdisk, no multifile, continue.
3313 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3315 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3316 -31 post/post.c POST test failed, detected by post_output_backlog()
3317 -32 post/post.c POST test failed, detected by post_run_single()
3319 34 common/cmd_doc.c before loading a Image from a DOC device
3320 -35 common/cmd_doc.c Bad usage of "doc" command
3321 35 common/cmd_doc.c correct usage of "doc" command
3322 -36 common/cmd_doc.c No boot device
3323 36 common/cmd_doc.c correct boot device
3324 -37 common/cmd_doc.c Unknown Chip ID on boot device
3325 37 common/cmd_doc.c correct chip ID found, device available
3326 -38 common/cmd_doc.c Read Error on boot device
3327 38 common/cmd_doc.c reading Image header from DOC device OK
3328 -39 common/cmd_doc.c Image header has bad magic number
3329 39 common/cmd_doc.c Image header has correct magic number
3330 -40 common/cmd_doc.c Error reading Image from DOC device
3331 40 common/cmd_doc.c Image header has correct magic number
3332 41 common/cmd_ide.c before loading a Image from a IDE device
3333 -42 common/cmd_ide.c Bad usage of "ide" command
3334 42 common/cmd_ide.c correct usage of "ide" command
3335 -43 common/cmd_ide.c No boot device
3336 43 common/cmd_ide.c boot device found
3337 -44 common/cmd_ide.c Device not available
3338 44 common/cmd_ide.c Device available
3339 -45 common/cmd_ide.c wrong partition selected
3340 45 common/cmd_ide.c partition selected
3341 -46 common/cmd_ide.c Unknown partition table
3342 46 common/cmd_ide.c valid partition table found
3343 -47 common/cmd_ide.c Invalid partition type
3344 47 common/cmd_ide.c correct partition type
3345 -48 common/cmd_ide.c Error reading Image Header on boot device
3346 48 common/cmd_ide.c reading Image Header from IDE device OK
3347 -49 common/cmd_ide.c Image header has bad magic number
3348 49 common/cmd_ide.c Image header has correct magic number
3349 -50 common/cmd_ide.c Image header has bad checksum
3350 50 common/cmd_ide.c Image header has correct checksum
3351 -51 common/cmd_ide.c Error reading Image from IDE device
3352 51 common/cmd_ide.c reading Image from IDE device OK
3353 52 common/cmd_nand.c before loading a Image from a NAND device
3354 -53 common/cmd_nand.c Bad usage of "nand" command
3355 53 common/cmd_nand.c correct usage of "nand" command
3356 -54 common/cmd_nand.c No boot device
3357 54 common/cmd_nand.c boot device found
3358 -55 common/cmd_nand.c Unknown Chip ID on boot device
3359 55 common/cmd_nand.c correct chip ID found, device available
3360 -56 common/cmd_nand.c Error reading Image Header on boot device
3361 56 common/cmd_nand.c reading Image Header from NAND device OK
3362 -57 common/cmd_nand.c Image header has bad magic number
3363 57 common/cmd_nand.c Image header has correct magic number
3364 -58 common/cmd_nand.c Error reading Image from NAND device
3365 58 common/cmd_nand.c reading Image from NAND device OK
3367 -60 common/env_common.c Environment has a bad CRC, using default
3369 64 net/eth.c starting with Ethernet configuration.
3370 -64 net/eth.c no Ethernet found.
3371 65 net/eth.c Ethernet found.
3373 -80 common/cmd_net.c usage wrong
3374 80 common/cmd_net.c before calling NetLoop()
3375 -81 common/cmd_net.c some error in NetLoop() occurred
3376 81 common/cmd_net.c NetLoop() back without error
3377 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3378 82 common/cmd_net.c trying automatic boot
3379 83 common/cmd_net.c running "source" command
3380 -83 common/cmd_net.c some error in automatic boot or "source" command
3381 84 common/cmd_net.c end without errors
3386 100 common/cmd_bootm.c Kernel FIT Image has correct format
3387 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3388 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3389 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3390 102 common/cmd_bootm.c Kernel unit name specified
3391 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3392 103 common/cmd_bootm.c Found configuration node
3393 104 common/cmd_bootm.c Got kernel subimage node offset
3394 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3395 105 common/cmd_bootm.c Kernel subimage hash verification OK
3396 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3397 106 common/cmd_bootm.c Architecture check OK
3398 -106 common/cmd_bootm.c Kernel subimage has wrong type
3399 107 common/cmd_bootm.c Kernel subimage type OK
3400 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3401 108 common/cmd_bootm.c Got kernel subimage data/size
3402 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3403 -109 common/cmd_bootm.c Can't get kernel subimage type
3404 -110 common/cmd_bootm.c Can't get kernel subimage comp
3405 -111 common/cmd_bootm.c Can't get kernel subimage os
3406 -112 common/cmd_bootm.c Can't get kernel subimage load address
3407 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3409 120 common/image.c Start initial ramdisk verification
3410 -120 common/image.c Ramdisk FIT image has incorrect format
3411 121 common/image.c Ramdisk FIT image has correct format
3412 122 common/image.c No ramdisk subimage unit name, using configuration
3413 -122 common/image.c Can't get configuration for ramdisk subimage
3414 123 common/image.c Ramdisk unit name specified
3415 -124 common/image.c Can't get ramdisk subimage node offset
3416 125 common/image.c Got ramdisk subimage node offset
3417 -125 common/image.c Ramdisk subimage hash verification failed
3418 126 common/image.c Ramdisk subimage hash verification OK
3419 -126 common/image.c Ramdisk subimage for unsupported architecture
3420 127 common/image.c Architecture check OK
3421 -127 common/image.c Can't get ramdisk subimage data/size
3422 128 common/image.c Got ramdisk subimage data/size
3423 129 common/image.c Can't get ramdisk load address
3424 -129 common/image.c Got ramdisk load address
3426 -130 common/cmd_doc.c Incorrect FIT image format
3427 131 common/cmd_doc.c FIT image format OK
3429 -140 common/cmd_ide.c Incorrect FIT image format
3430 141 common/cmd_ide.c FIT image format OK
3432 -150 common/cmd_nand.c Incorrect FIT image format
3433 151 common/cmd_nand.c FIT image format OK
3435 - legacy image format:
3436 CONFIG_IMAGE_FORMAT_LEGACY
3437 enables the legacy image format support in U-Boot.
3440 enabled if CONFIG_FIT_SIGNATURE is not defined.
3442 CONFIG_DISABLE_IMAGE_LEGACY
3443 disable the legacy image format
3445 This define is introduced, as the legacy image format is
3446 enabled per default for backward compatibility.
3448 - FIT image support:
3450 Enable support for the FIT uImage format.
3452 CONFIG_FIT_BEST_MATCH
3453 When no configuration is explicitly selected, default to the
3454 one whose fdt's compatibility field best matches that of
3455 U-Boot itself. A match is considered "best" if it matches the
3456 most specific compatibility entry of U-Boot's fdt's root node.
3457 The order of entries in the configuration's fdt is ignored.
3459 CONFIG_FIT_SIGNATURE
3460 This option enables signature verification of FIT uImages,
3461 using a hash signed and verified using RSA. See
3462 doc/uImage.FIT/signature.txt for more details.
3464 WARNING: When relying on signed FIT images with required
3465 signature check the legacy image format is default
3466 disabled. If a board need legacy image format support
3467 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3469 CONFIG_FIT_DISABLE_SHA256
3470 Supporting SHA256 hashes has quite an impact on binary size.
3471 For constrained systems sha256 hash support can be disabled
3474 - Standalone program support:
3475 CONFIG_STANDALONE_LOAD_ADDR
3477 This option defines a board specific value for the
3478 address where standalone program gets loaded, thus
3479 overwriting the architecture dependent default
3482 - Frame Buffer Address:
3485 Define CONFIG_FB_ADDR if you want to use specific
3486 address for frame buffer. This is typically the case
3487 when using a graphics controller has separate video
3488 memory. U-Boot will then place the frame buffer at
3489 the given address instead of dynamically reserving it
3490 in system RAM by calling lcd_setmem(), which grabs
3491 the memory for the frame buffer depending on the
3492 configured panel size.
3494 Please see board_init_f function.
3496 - Automatic software updates via TFTP server
3498 CONFIG_UPDATE_TFTP_CNT_MAX
3499 CONFIG_UPDATE_TFTP_MSEC_MAX
3501 These options enable and control the auto-update feature;
3502 for a more detailed description refer to doc/README.update.
3504 - MTD Support (mtdparts command, UBI support)
3507 Adds the MTD device infrastructure from the Linux kernel.
3508 Needed for mtdparts command support.
3510 CONFIG_MTD_PARTITIONS
3512 Adds the MTD partitioning infrastructure from the Linux
3513 kernel. Needed for UBI support.
3515 CONFIG_MTD_NAND_VERIFY_WRITE
3516 verify if the written data is correct reread.
3521 Adds commands for interacting with MTD partitions formatted
3522 with the UBI flash translation layer
3524 Requires also defining CONFIG_RBTREE
3526 CONFIG_UBI_SILENCE_MSG
3528 Make the verbose messages from UBI stop printing. This leaves
3529 warnings and errors enabled.
3532 CONFIG_MTD_UBI_WL_THRESHOLD
3533 This parameter defines the maximum difference between the highest
3534 erase counter value and the lowest erase counter value of eraseblocks
3535 of UBI devices. When this threshold is exceeded, UBI starts performing
3536 wear leveling by means of moving data from eraseblock with low erase
3537 counter to eraseblocks with high erase counter.
3539 The default value should be OK for SLC NAND flashes, NOR flashes and
3540 other flashes which have eraseblock life-cycle 100000 or more.
3541 However, in case of MLC NAND flashes which typically have eraseblock
3542 life-cycle less than 10000, the threshold should be lessened (e.g.,
3543 to 128 or 256, although it does not have to be power of 2).
3547 CONFIG_MTD_UBI_BEB_LIMIT
3548 This option specifies the maximum bad physical eraseblocks UBI
3549 expects on the MTD device (per 1024 eraseblocks). If the
3550 underlying flash does not admit of bad eraseblocks (e.g. NOR
3551 flash), this value is ignored.
3553 NAND datasheets often specify the minimum and maximum NVM
3554 (Number of Valid Blocks) for the flashes' endurance lifetime.
3555 The maximum expected bad eraseblocks per 1024 eraseblocks
3556 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3557 which gives 20 for most NANDs (MaxNVB is basically the total
3558 count of eraseblocks on the chip).
3560 To put it differently, if this value is 20, UBI will try to
3561 reserve about 1.9% of physical eraseblocks for bad blocks
3562 handling. And that will be 1.9% of eraseblocks on the entire
3563 NAND chip, not just the MTD partition UBI attaches. This means
3564 that if you have, say, a NAND flash chip admits maximum 40 bad
3565 eraseblocks, and it is split on two MTD partitions of the same
3566 size, UBI will reserve 40 eraseblocks when attaching a
3571 CONFIG_MTD_UBI_FASTMAP
3572 Fastmap is a mechanism which allows attaching an UBI device
3573 in nearly constant time. Instead of scanning the whole MTD device it
3574 only has to locate a checkpoint (called fastmap) on the device.
3575 The on-flash fastmap contains all information needed to attach
3576 the device. Using fastmap makes only sense on large devices where
3577 attaching by scanning takes long. UBI will not automatically install
3578 a fastmap on old images, but you can set the UBI parameter
3579 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3580 that fastmap-enabled images are still usable with UBI implementations
3581 without fastmap support. On typical flash devices the whole fastmap
3582 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3584 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3585 Set this parameter to enable fastmap automatically on images
3592 Adds commands for interacting with UBI volumes formatted as
3593 UBIFS. UBIFS is read-only in u-boot.
3595 Requires UBI support as well as CONFIG_LZO
3597 CONFIG_UBIFS_SILENCE_MSG
3599 Make the verbose messages from UBIFS stop printing. This leaves
3600 warnings and errors enabled.
3604 Enable building of SPL globally.
3607 LDSCRIPT for linking the SPL binary.
3609 CONFIG_SPL_MAX_FOOTPRINT
3610 Maximum size in memory allocated to the SPL, BSS included.
3611 When defined, the linker checks that the actual memory
3612 used by SPL from _start to __bss_end does not exceed it.
3613 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3614 must not be both defined at the same time.
3617 Maximum size of the SPL image (text, data, rodata, and
3618 linker lists sections), BSS excluded.
3619 When defined, the linker checks that the actual size does
3622 CONFIG_SPL_TEXT_BASE
3623 TEXT_BASE for linking the SPL binary.
3625 CONFIG_SPL_RELOC_TEXT_BASE
3626 Address to relocate to. If unspecified, this is equal to
3627 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3629 CONFIG_SPL_BSS_START_ADDR
3630 Link address for the BSS within the SPL binary.
3632 CONFIG_SPL_BSS_MAX_SIZE
3633 Maximum size in memory allocated to the SPL BSS.
3634 When defined, the linker checks that the actual memory used
3635 by SPL from __bss_start to __bss_end does not exceed it.
3636 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3637 must not be both defined at the same time.
3640 Adress of the start of the stack SPL will use
3642 CONFIG_SPL_RELOC_STACK
3643 Adress of the start of the stack SPL will use after
3644 relocation. If unspecified, this is equal to
3647 CONFIG_SYS_SPL_MALLOC_START
3648 Starting address of the malloc pool used in SPL.
3650 CONFIG_SYS_SPL_MALLOC_SIZE
3651 The size of the malloc pool used in SPL.
3653 CONFIG_SPL_FRAMEWORK
3654 Enable the SPL framework under common/. This framework
3655 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3656 NAND loading of the Linux Kernel.
3659 Enable booting directly to an OS from SPL.
3660 See also: doc/README.falcon
3662 CONFIG_SPL_DISPLAY_PRINT
3663 For ARM, enable an optional function to print more information
3664 about the running system.
3666 CONFIG_SPL_INIT_MINIMAL
3667 Arch init code should be built for a very small image
3669 CONFIG_SPL_LIBCOMMON_SUPPORT
3670 Support for common/libcommon.o in SPL binary
3672 CONFIG_SPL_LIBDISK_SUPPORT
3673 Support for disk/libdisk.o in SPL binary
3675 CONFIG_SPL_I2C_SUPPORT
3676 Support for drivers/i2c/libi2c.o in SPL binary
3678 CONFIG_SPL_GPIO_SUPPORT
3679 Support for drivers/gpio/libgpio.o in SPL binary
3681 CONFIG_SPL_MMC_SUPPORT
3682 Support for drivers/mmc/libmmc.o in SPL binary
3684 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3685 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3686 Address and partition on the MMC to load U-Boot from
3687 when the MMC is being used in raw mode.
3689 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3690 Partition on the MMC to load U-Boot from when the MMC is being
3693 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3694 Sector to load kernel uImage from when MMC is being
3695 used in raw mode (for Falcon mode)
3697 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3698 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3699 Sector and number of sectors to load kernel argument
3700 parameters from when MMC is being used in raw mode
3703 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3704 Partition on the MMC to load U-Boot from when the MMC is being
3707 CONFIG_SPL_FAT_SUPPORT
3708 Support for fs/fat/libfat.o in SPL binary
3710 CONFIG_SPL_EXT_SUPPORT
3711 Support for EXT filesystem in SPL binary
3713 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3714 Filename to read to load U-Boot when reading from filesystem
3716 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3717 Filename to read to load kernel uImage when reading
3718 from filesystem (for Falcon mode)
3720 CONFIG_SPL_FS_LOAD_ARGS_NAME
3721 Filename to read to load kernel argument parameters
3722 when reading from filesystem (for Falcon mode)
3724 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3725 Set this for NAND SPL on PPC mpc83xx targets, so that
3726 start.S waits for the rest of the SPL to load before
3727 continuing (the hardware starts execution after just
3728 loading the first page rather than the full 4K).
3730 CONFIG_SPL_SKIP_RELOCATE
3731 Avoid SPL relocation
3733 CONFIG_SPL_NAND_BASE
3734 Include nand_base.c in the SPL. Requires
3735 CONFIG_SPL_NAND_DRIVERS.
3737 CONFIG_SPL_NAND_DRIVERS
3738 SPL uses normal NAND drivers, not minimal drivers.
3741 Include standard software ECC in the SPL
3743 CONFIG_SPL_NAND_SIMPLE
3744 Support for NAND boot using simple NAND drivers that
3745 expose the cmd_ctrl() interface.
3747 CONFIG_SPL_MTD_SUPPORT
3748 Support for the MTD subsystem within SPL. Useful for
3749 environment on NAND support within SPL.
3751 CONFIG_SPL_NAND_RAW_ONLY
3752 Support to boot only raw u-boot.bin images. Use this only
3753 if you need to save space.
3755 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3756 Set for the SPL on PPC mpc8xxx targets, support for
3757 drivers/ddr/fsl/libddr.o in SPL binary.
3759 CONFIG_SPL_COMMON_INIT_DDR
3760 Set for common ddr init with serial presence detect in
3763 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3764 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3765 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3766 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3767 CONFIG_SYS_NAND_ECCBYTES
3768 Defines the size and behavior of the NAND that SPL uses
3771 CONFIG_SPL_NAND_BOOT
3772 Add support NAND boot
3774 CONFIG_SYS_NAND_U_BOOT_OFFS
3775 Location in NAND to read U-Boot from
3777 CONFIG_SYS_NAND_U_BOOT_DST
3778 Location in memory to load U-Boot to
3780 CONFIG_SYS_NAND_U_BOOT_SIZE
3781 Size of image to load
3783 CONFIG_SYS_NAND_U_BOOT_START
3784 Entry point in loaded image to jump to
3786 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3787 Define this if you need to first read the OOB and then the
3788 data. This is used, for example, on davinci platforms.
3790 CONFIG_SPL_OMAP3_ID_NAND
3791 Support for an OMAP3-specific set of functions to return the
3792 ID and MFR of the first attached NAND chip, if present.
3794 CONFIG_SPL_SERIAL_SUPPORT
3795 Support for drivers/serial/libserial.o in SPL binary
3797 CONFIG_SPL_SPI_FLASH_SUPPORT
3798 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3800 CONFIG_SPL_SPI_SUPPORT
3801 Support for drivers/spi/libspi.o in SPL binary
3803 CONFIG_SPL_RAM_DEVICE
3804 Support for running image already present in ram, in SPL binary
3806 CONFIG_SPL_LIBGENERIC_SUPPORT
3807 Support for lib/libgeneric.o in SPL binary
3809 CONFIG_SPL_ENV_SUPPORT
3810 Support for the environment operating in SPL binary
3812 CONFIG_SPL_NET_SUPPORT
3813 Support for the net/libnet.o in SPL binary.
3814 It conflicts with SPL env from storage medium specified by
3815 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3818 Image offset to which the SPL should be padded before appending
3819 the SPL payload. By default, this is defined as
3820 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3821 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3822 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3825 Final target image containing SPL and payload. Some SPLs
3826 use an arch-specific makefile fragment instead, for
3827 example if more than one image needs to be produced.
3829 CONFIG_FIT_SPL_PRINT
3830 Printing information about a FIT image adds quite a bit of
3831 code to SPL. So this is normally disabled in SPL. Use this
3832 option to re-enable it. This will affect the output of the
3833 bootm command when booting a FIT image.
3837 Enable building of TPL globally.
3840 Image offset to which the TPL should be padded before appending
3841 the TPL payload. By default, this is defined as
3842 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3843 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3844 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3849 [so far only for SMDK2400 boards]
3851 - Modem support enable:
3852 CONFIG_MODEM_SUPPORT
3854 - RTS/CTS Flow control enable:
3857 - Modem debug support:
3858 CONFIG_MODEM_SUPPORT_DEBUG
3860 Enables debugging stuff (char screen[1024], dbg())
3861 for modem support. Useful only with BDI2000.
3863 - Interrupt support (PPC):
3865 There are common interrupt_init() and timer_interrupt()
3866 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3867 for CPU specific initialization. interrupt_init_cpu()
3868 should set decrementer_count to appropriate value. If
3869 CPU resets decrementer automatically after interrupt
3870 (ppc4xx) it should set decrementer_count to zero.
3871 timer_interrupt() calls timer_interrupt_cpu() for CPU
3872 specific handling. If board has watchdog / status_led
3873 / other_activity_monitor it works automatically from
3874 general timer_interrupt().
3878 In the target system modem support is enabled when a
3879 specific key (key combination) is pressed during
3880 power-on. Otherwise U-Boot will boot normally
3881 (autoboot). The key_pressed() function is called from
3882 board_init(). Currently key_pressed() is a dummy
3883 function, returning 1 and thus enabling modem
3886 If there are no modem init strings in the
3887 environment, U-Boot proceed to autoboot; the
3888 previous output (banner, info printfs) will be
3891 See also: doc/README.Modem
3893 Board initialization settings:
3894 ------------------------------
3896 During Initialization u-boot calls a number of board specific functions
3897 to allow the preparation of board specific prerequisites, e.g. pin setup
3898 before drivers are initialized. To enable these callbacks the
3899 following configuration macros have to be defined. Currently this is
3900 architecture specific, so please check arch/your_architecture/lib/board.c
3901 typically in board_init_f() and board_init_r().
3903 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3904 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3905 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3906 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3908 Configuration Settings:
3909 -----------------------
3911 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3912 Optionally it can be defined to support 64-bit memory commands.
3914 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3915 undefine this when you're short of memory.
3917 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3918 width of the commands listed in the 'help' command output.
3920 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3921 prompt for user input.
3923 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3925 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3927 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3929 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3930 the application (usually a Linux kernel) when it is
3933 - CONFIG_SYS_BAUDRATE_TABLE:
3934 List of legal baudrate settings for this board.
3936 - CONFIG_SYS_CONSOLE_INFO_QUIET
3937 Suppress display of console information at boot.
3939 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3940 If the board specific function
3941 extern int overwrite_console (void);
3942 returns 1, the stdin, stderr and stdout are switched to the
3943 serial port, else the settings in the environment are used.
3945 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3946 Enable the call to overwrite_console().
3948 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3949 Enable overwrite of previous console environment settings.
3951 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3952 Begin and End addresses of the area used by the
3955 - CONFIG_SYS_ALT_MEMTEST:
3956 Enable an alternate, more extensive memory test.
3958 - CONFIG_SYS_MEMTEST_SCRATCH:
3959 Scratch address used by the alternate memory test
3960 You only need to set this if address zero isn't writeable
3962 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3963 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3964 this specified memory area will get subtracted from the top
3965 (end) of RAM and won't get "touched" at all by U-Boot. By
3966 fixing up gd->ram_size the Linux kernel should gets passed
3967 the now "corrected" memory size and won't touch it either.
3968 This should work for arch/ppc and arch/powerpc. Only Linux
3969 board ports in arch/powerpc with bootwrapper support that
3970 recalculate the memory size from the SDRAM controller setup
3971 will have to get fixed in Linux additionally.
3973 This option can be used as a workaround for the 440EPx/GRx
3974 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3977 WARNING: Please make sure that this value is a multiple of
3978 the Linux page size (normally 4k). If this is not the case,
3979 then the end address of the Linux memory will be located at a
3980 non page size aligned address and this could cause major
3983 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3984 Enable temporary baudrate change while serial download
3986 - CONFIG_SYS_SDRAM_BASE:
3987 Physical start address of SDRAM. _Must_ be 0 here.
3989 - CONFIG_SYS_MBIO_BASE:
3990 Physical start address of Motherboard I/O (if using a
3993 - CONFIG_SYS_FLASH_BASE:
3994 Physical start address of Flash memory.
3996 - CONFIG_SYS_MONITOR_BASE:
3997 Physical start address of boot monitor code (set by
3998 make config files to be same as the text base address
3999 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
4000 CONFIG_SYS_FLASH_BASE when booting from flash.
4002 - CONFIG_SYS_MONITOR_LEN:
4003 Size of memory reserved for monitor code, used to
4004 determine _at_compile_time_ (!) if the environment is
4005 embedded within the U-Boot image, or in a separate
4008 - CONFIG_SYS_MALLOC_LEN:
4009 Size of DRAM reserved for malloc() use.
4011 - CONFIG_SYS_MALLOC_F_LEN
4012 Size of the malloc() pool for use before relocation. If
4013 this is defined, then a very simple malloc() implementation
4014 will become available before relocation. The address is just
4015 below the global data, and the stack is moved down to make
4018 This feature allocates regions with increasing addresses
4019 within the region. calloc() is supported, but realloc()
4020 is not available. free() is supported but does nothing.
4021 The memory will be freed (or in fact just forgotten) when
4022 U-Boot relocates itself.
4024 Pre-relocation malloc() is only supported on ARM and sandbox
4025 at present but is fairly easy to enable for other archs.
4027 - CONFIG_SYS_MALLOC_SIMPLE
4028 Provides a simple and small malloc() and calloc() for those
4029 boards which do not use the full malloc in SPL (which is
4030 enabled with CONFIG_SYS_SPL_MALLOC_START).
4032 - CONFIG_SYS_NONCACHED_MEMORY:
4033 Size of non-cached memory area. This area of memory will be
4034 typically located right below the malloc() area and mapped
4035 uncached in the MMU. This is useful for drivers that would
4036 otherwise require a lot of explicit cache maintenance. For
4037 some drivers it's also impossible to properly maintain the
4038 cache. For example if the regions that need to be flushed
4039 are not a multiple of the cache-line size, *and* padding
4040 cannot be allocated between the regions to align them (i.e.
4041 if the HW requires a contiguous array of regions, and the
4042 size of each region is not cache-aligned), then a flush of
4043 one region may result in overwriting data that hardware has
4044 written to another region in the same cache-line. This can
4045 happen for example in network drivers where descriptors for
4046 buffers are typically smaller than the CPU cache-line (e.g.
4047 16 bytes vs. 32 or 64 bytes).
4049 Non-cached memory is only supported on 32-bit ARM at present.
4051 - CONFIG_SYS_BOOTM_LEN:
4052 Normally compressed uImages are limited to an
4053 uncompressed size of 8 MBytes. If this is not enough,
4054 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4055 to adjust this setting to your needs.
4057 - CONFIG_SYS_BOOTMAPSZ:
4058 Maximum size of memory mapped by the startup code of
4059 the Linux kernel; all data that must be processed by
4060 the Linux kernel (bd_info, boot arguments, FDT blob if
4061 used) must be put below this limit, unless "bootm_low"
4062 environment variable is defined and non-zero. In such case
4063 all data for the Linux kernel must be between "bootm_low"
4064 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4065 variable "bootm_mapsize" will override the value of
4066 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4067 then the value in "bootm_size" will be used instead.
4069 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4070 Enable initrd_high functionality. If defined then the
4071 initrd_high feature is enabled and the bootm ramdisk subcommand
4074 - CONFIG_SYS_BOOT_GET_CMDLINE:
4075 Enables allocating and saving kernel cmdline in space between
4076 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4078 - CONFIG_SYS_BOOT_GET_KBD:
4079 Enables allocating and saving a kernel copy of the bd_info in
4080 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4082 - CONFIG_SYS_MAX_FLASH_BANKS:
4083 Max number of Flash memory banks
4085 - CONFIG_SYS_MAX_FLASH_SECT:
4086 Max number of sectors on a Flash chip
4088 - CONFIG_SYS_FLASH_ERASE_TOUT:
4089 Timeout for Flash erase operations (in ms)
4091 - CONFIG_SYS_FLASH_WRITE_TOUT:
4092 Timeout for Flash write operations (in ms)
4094 - CONFIG_SYS_FLASH_LOCK_TOUT
4095 Timeout for Flash set sector lock bit operation (in ms)
4097 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4098 Timeout for Flash clear lock bits operation (in ms)
4100 - CONFIG_SYS_FLASH_PROTECTION
4101 If defined, hardware flash sectors protection is used
4102 instead of U-Boot software protection.
4104 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4106 Enable TFTP transfers directly to flash memory;
4107 without this option such a download has to be
4108 performed in two steps: (1) download to RAM, and (2)
4109 copy from RAM to flash.
4111 The two-step approach is usually more reliable, since
4112 you can check if the download worked before you erase
4113 the flash, but in some situations (when system RAM is
4114 too limited to allow for a temporary copy of the
4115 downloaded image) this option may be very useful.
4117 - CONFIG_SYS_FLASH_CFI:
4118 Define if the flash driver uses extra elements in the
4119 common flash structure for storing flash geometry.
4121 - CONFIG_FLASH_CFI_DRIVER
4122 This option also enables the building of the cfi_flash driver
4123 in the drivers directory
4125 - CONFIG_FLASH_CFI_MTD
4126 This option enables the building of the cfi_mtd driver
4127 in the drivers directory. The driver exports CFI flash
4130 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4131 Use buffered writes to flash.
4133 - CONFIG_FLASH_SPANSION_S29WS_N
4134 s29ws-n MirrorBit flash has non-standard addresses for buffered
4137 - CONFIG_SYS_FLASH_QUIET_TEST
4138 If this option is defined, the common CFI flash doesn't
4139 print it's warning upon not recognized FLASH banks. This
4140 is useful, if some of the configured banks are only
4141 optionally available.
4143 - CONFIG_FLASH_SHOW_PROGRESS
4144 If defined (must be an integer), print out countdown
4145 digits and dots. Recommended value: 45 (9..1) for 80
4146 column displays, 15 (3..1) for 40 column displays.
4148 - CONFIG_FLASH_VERIFY
4149 If defined, the content of the flash (destination) is compared
4150 against the source after the write operation. An error message
4151 will be printed when the contents are not identical.
4152 Please note that this option is useless in nearly all cases,
4153 since such flash programming errors usually are detected earlier
4154 while unprotecting/erasing/programming. Please only enable
4155 this option if you really know what you are doing.
4157 - CONFIG_SYS_RX_ETH_BUFFER:
4158 Defines the number of Ethernet receive buffers. On some
4159 Ethernet controllers it is recommended to set this value
4160 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4161 buffers can be full shortly after enabling the interface
4162 on high Ethernet traffic.
4163 Defaults to 4 if not defined.
4165 - CONFIG_ENV_MAX_ENTRIES
4167 Maximum number of entries in the hash table that is used
4168 internally to store the environment settings. The default
4169 setting is supposed to be generous and should work in most
4170 cases. This setting can be used to tune behaviour; see
4171 lib/hashtable.c for details.
4173 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4174 - CONFIG_ENV_FLAGS_LIST_STATIC
4175 Enable validation of the values given to environment variables when
4176 calling env set. Variables can be restricted to only decimal,
4177 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4178 the variables can also be restricted to IP address or MAC address.
4180 The format of the list is:
4181 type_attribute = [s|d|x|b|i|m]
4182 access_attribute = [a|r|o|c]
4183 attributes = type_attribute[access_attribute]
4184 entry = variable_name[:attributes]
4187 The type attributes are:
4188 s - String (default)
4191 b - Boolean ([1yYtT|0nNfF])
4195 The access attributes are:
4201 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4202 Define this to a list (string) to define the ".flags"
4203 environment variable in the default or embedded environment.
4205 - CONFIG_ENV_FLAGS_LIST_STATIC
4206 Define this to a list (string) to define validation that
4207 should be done if an entry is not found in the ".flags"
4208 environment variable. To override a setting in the static
4209 list, simply add an entry for the same variable name to the
4212 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4213 If defined, don't allow the -f switch to env set override variable
4216 - CONFIG_SYS_GENERIC_BOARD
4217 This selects the architecture-generic board system instead of the
4218 architecture-specific board files. It is intended to move boards
4219 to this new framework over time. Defining this will disable the
4220 arch/foo/lib/board.c file and use common/board_f.c and
4221 common/board_r.c instead. To use this option your architecture
4222 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4223 its config.mk file). If you find problems enabling this option on
4224 your board please report the problem and send patches!
4226 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4227 This is set by OMAP boards for the max time that reset should
4228 be asserted. See doc/README.omap-reset-time for details on how
4229 the value can be calculated on a given board.
4232 If stdint.h is available with your toolchain you can define this
4233 option to enable it. You can provide option 'USE_STDINT=1' when
4234 building U-Boot to enable this.
4236 The following definitions that deal with the placement and management
4237 of environment data (variable area); in general, we support the
4238 following configurations:
4240 - CONFIG_BUILD_ENVCRC:
4242 Builds up envcrc with the target environment so that external utils
4243 may easily extract it and embed it in final U-Boot images.
4245 - CONFIG_ENV_IS_IN_FLASH:
4247 Define this if the environment is in flash memory.
4249 a) The environment occupies one whole flash sector, which is
4250 "embedded" in the text segment with the U-Boot code. This
4251 happens usually with "bottom boot sector" or "top boot
4252 sector" type flash chips, which have several smaller
4253 sectors at the start or the end. For instance, such a
4254 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4255 such a case you would place the environment in one of the
4256 4 kB sectors - with U-Boot code before and after it. With
4257 "top boot sector" type flash chips, you would put the
4258 environment in one of the last sectors, leaving a gap
4259 between U-Boot and the environment.
4261 - CONFIG_ENV_OFFSET:
4263 Offset of environment data (variable area) to the
4264 beginning of flash memory; for instance, with bottom boot
4265 type flash chips the second sector can be used: the offset
4266 for this sector is given here.
4268 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4272 This is just another way to specify the start address of
4273 the flash sector containing the environment (instead of
4276 - CONFIG_ENV_SECT_SIZE:
4278 Size of the sector containing the environment.
4281 b) Sometimes flash chips have few, equal sized, BIG sectors.
4282 In such a case you don't want to spend a whole sector for
4287 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4288 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4289 of this flash sector for the environment. This saves
4290 memory for the RAM copy of the environment.
4292 It may also save flash memory if you decide to use this
4293 when your environment is "embedded" within U-Boot code,
4294 since then the remainder of the flash sector could be used
4295 for U-Boot code. It should be pointed out that this is
4296 STRONGLY DISCOURAGED from a robustness point of view:
4297 updating the environment in flash makes it always
4298 necessary to erase the WHOLE sector. If something goes
4299 wrong before the contents has been restored from a copy in
4300 RAM, your target system will be dead.
4302 - CONFIG_ENV_ADDR_REDUND
4303 CONFIG_ENV_SIZE_REDUND
4305 These settings describe a second storage area used to hold
4306 a redundant copy of the environment data, so that there is
4307 a valid backup copy in case there is a power failure during
4308 a "saveenv" operation.
4310 BE CAREFUL! Any changes to the flash layout, and some changes to the
4311 source code will make it necessary to adapt <board>/u-boot.lds*
4315 - CONFIG_ENV_IS_IN_NVRAM:
4317 Define this if you have some non-volatile memory device
4318 (NVRAM, battery buffered SRAM) which you want to use for the
4324 These two #defines are used to determine the memory area you
4325 want to use for environment. It is assumed that this memory
4326 can just be read and written to, without any special
4329 BE CAREFUL! The first access to the environment happens quite early
4330 in U-Boot initialization (when we try to get the setting of for the
4331 console baudrate). You *MUST* have mapped your NVRAM area then, or
4334 Please note that even with NVRAM we still use a copy of the
4335 environment in RAM: we could work on NVRAM directly, but we want to
4336 keep settings there always unmodified except somebody uses "saveenv"
4337 to save the current settings.
4340 - CONFIG_ENV_IS_IN_EEPROM:
4342 Use this if you have an EEPROM or similar serial access
4343 device and a driver for it.
4345 - CONFIG_ENV_OFFSET:
4348 These two #defines specify the offset and size of the
4349 environment area within the total memory of your EEPROM.
4351 - CONFIG_SYS_I2C_EEPROM_ADDR:
4352 If defined, specified the chip address of the EEPROM device.
4353 The default address is zero.
4355 - CONFIG_SYS_I2C_EEPROM_BUS:
4356 If defined, specified the i2c bus of the EEPROM device.
4358 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4359 If defined, the number of bits used to address bytes in a
4360 single page in the EEPROM device. A 64 byte page, for example
4361 would require six bits.
4363 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4364 If defined, the number of milliseconds to delay between
4365 page writes. The default is zero milliseconds.
4367 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4368 The length in bytes of the EEPROM memory array address. Note
4369 that this is NOT the chip address length!
4371 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4372 EEPROM chips that implement "address overflow" are ones
4373 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4374 address and the extra bits end up in the "chip address" bit
4375 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4378 Note that we consider the length of the address field to
4379 still be one byte because the extra address bits are hidden
4380 in the chip address.
4382 - CONFIG_SYS_EEPROM_SIZE:
4383 The size in bytes of the EEPROM device.
4385 - CONFIG_ENV_EEPROM_IS_ON_I2C
4386 define this, if you have I2C and SPI activated, and your
4387 EEPROM, which holds the environment, is on the I2C bus.
4389 - CONFIG_I2C_ENV_EEPROM_BUS
4390 if you have an Environment on an EEPROM reached over
4391 I2C muxes, you can define here, how to reach this
4392 EEPROM. For example:
4394 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4396 EEPROM which holds the environment, is reached over
4397 a pca9547 i2c mux with address 0x70, channel 3.
4399 - CONFIG_ENV_IS_IN_DATAFLASH:
4401 Define this if you have a DataFlash memory device which you
4402 want to use for the environment.
4404 - CONFIG_ENV_OFFSET:
4408 These three #defines specify the offset and size of the
4409 environment area within the total memory of your DataFlash placed
4410 at the specified address.
4412 - CONFIG_ENV_IS_IN_SPI_FLASH:
4414 Define this if you have a SPI Flash memory device which you
4415 want to use for the environment.
4417 - CONFIG_ENV_OFFSET:
4420 These two #defines specify the offset and size of the
4421 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4422 aligned to an erase sector boundary.
4424 - CONFIG_ENV_SECT_SIZE:
4426 Define the SPI flash's sector size.
4428 - CONFIG_ENV_OFFSET_REDUND (optional):
4430 This setting describes a second storage area of CONFIG_ENV_SIZE
4431 size used to hold a redundant copy of the environment data, so
4432 that there is a valid backup copy in case there is a power failure
4433 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4434 aligned to an erase sector boundary.
4436 - CONFIG_ENV_SPI_BUS (optional):
4437 - CONFIG_ENV_SPI_CS (optional):
4439 Define the SPI bus and chip select. If not defined they will be 0.
4441 - CONFIG_ENV_SPI_MAX_HZ (optional):
4443 Define the SPI max work clock. If not defined then use 1MHz.
4445 - CONFIG_ENV_SPI_MODE (optional):
4447 Define the SPI work mode. If not defined then use SPI_MODE_3.
4449 - CONFIG_ENV_IS_IN_REMOTE:
4451 Define this if you have a remote memory space which you
4452 want to use for the local device's environment.
4457 These two #defines specify the address and size of the
4458 environment area within the remote memory space. The
4459 local device can get the environment from remote memory
4460 space by SRIO or PCIE links.
4462 BE CAREFUL! For some special cases, the local device can not use
4463 "saveenv" command. For example, the local device will get the
4464 environment stored in a remote NOR flash by SRIO or PCIE link,
4465 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4467 - CONFIG_ENV_IS_IN_NAND:
4469 Define this if you have a NAND device which you want to use
4470 for the environment.
4472 - CONFIG_ENV_OFFSET:
4475 These two #defines specify the offset and size of the environment
4476 area within the first NAND device. CONFIG_ENV_OFFSET must be
4477 aligned to an erase block boundary.
4479 - CONFIG_ENV_OFFSET_REDUND (optional):
4481 This setting describes a second storage area of CONFIG_ENV_SIZE
4482 size used to hold a redundant copy of the environment data, so
4483 that there is a valid backup copy in case there is a power failure
4484 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4485 aligned to an erase block boundary.
4487 - CONFIG_ENV_RANGE (optional):
4489 Specifies the length of the region in which the environment
4490 can be written. This should be a multiple of the NAND device's
4491 block size. Specifying a range with more erase blocks than
4492 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4493 the range to be avoided.
4495 - CONFIG_ENV_OFFSET_OOB (optional):
4497 Enables support for dynamically retrieving the offset of the
4498 environment from block zero's out-of-band data. The
4499 "nand env.oob" command can be used to record this offset.
4500 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4501 using CONFIG_ENV_OFFSET_OOB.
4503 - CONFIG_NAND_ENV_DST
4505 Defines address in RAM to which the nand_spl code should copy the
4506 environment. If redundant environment is used, it will be copied to
4507 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4509 - CONFIG_ENV_IS_IN_UBI:
4511 Define this if you have an UBI volume that you want to use for the
4512 environment. This has the benefit of wear-leveling the environment
4513 accesses, which is important on NAND.
4515 - CONFIG_ENV_UBI_PART:
4517 Define this to a string that is the mtd partition containing the UBI.
4519 - CONFIG_ENV_UBI_VOLUME:
4521 Define this to the name of the volume that you want to store the
4524 - CONFIG_ENV_UBI_VOLUME_REDUND:
4526 Define this to the name of another volume to store a second copy of
4527 the environment in. This will enable redundant environments in UBI.
4528 It is assumed that both volumes are in the same MTD partition.
4530 - CONFIG_UBI_SILENCE_MSG
4531 - CONFIG_UBIFS_SILENCE_MSG
4533 You will probably want to define these to avoid a really noisy system
4534 when storing the env in UBI.
4536 - CONFIG_ENV_IS_IN_FAT:
4537 Define this if you want to use the FAT file system for the environment.
4539 - FAT_ENV_INTERFACE:
4541 Define this to a string that is the name of the block device.
4543 - FAT_ENV_DEV_AND_PART:
4545 Define this to a string to specify the partition of the device. It can
4548 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4549 - "D:P": device D partition P. Error occurs if device D has no
4552 - "D" or "D:": device D partition 1 if device D has partition
4553 table, or the whole device D if has no partition
4555 - "D:auto": first partition in device D with bootable flag set.
4556 If none, first valid partition in device D. If no
4557 partition table then means device D.
4561 It's a string of the FAT file name. This file use to store the
4565 This should be defined. Otherwise it cannot save the environment file.
4567 - CONFIG_ENV_IS_IN_MMC:
4569 Define this if you have an MMC device which you want to use for the
4572 - CONFIG_SYS_MMC_ENV_DEV:
4574 Specifies which MMC device the environment is stored in.
4576 - CONFIG_SYS_MMC_ENV_PART (optional):
4578 Specifies which MMC partition the environment is stored in. If not
4579 set, defaults to partition 0, the user area. Common values might be
4580 1 (first MMC boot partition), 2 (second MMC boot partition).
4582 - CONFIG_ENV_OFFSET:
4585 These two #defines specify the offset and size of the environment
4586 area within the specified MMC device.
4588 If offset is positive (the usual case), it is treated as relative to
4589 the start of the MMC partition. If offset is negative, it is treated
4590 as relative to the end of the MMC partition. This can be useful if
4591 your board may be fitted with different MMC devices, which have
4592 different sizes for the MMC partitions, and you always want the
4593 environment placed at the very end of the partition, to leave the
4594 maximum possible space before it, to store other data.
4596 These two values are in units of bytes, but must be aligned to an
4597 MMC sector boundary.
4599 - CONFIG_ENV_OFFSET_REDUND (optional):
4601 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4602 hold a redundant copy of the environment data. This provides a
4603 valid backup copy in case the other copy is corrupted, e.g. due
4604 to a power failure during a "saveenv" operation.
4606 This value may also be positive or negative; this is handled in the
4607 same way as CONFIG_ENV_OFFSET.
4609 This value is also in units of bytes, but must also be aligned to
4610 an MMC sector boundary.
4612 - CONFIG_ENV_SIZE_REDUND (optional):
4614 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4615 set. If this value is set, it must be set to the same value as
4618 - CONFIG_SYS_SPI_INIT_OFFSET
4620 Defines offset to the initial SPI buffer area in DPRAM. The
4621 area is used at an early stage (ROM part) if the environment
4622 is configured to reside in the SPI EEPROM: We need a 520 byte
4623 scratch DPRAM area. It is used between the two initialization
4624 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4625 to be a good choice since it makes it far enough from the
4626 start of the data area as well as from the stack pointer.
4628 Please note that the environment is read-only until the monitor
4629 has been relocated to RAM and a RAM copy of the environment has been
4630 created; also, when using EEPROM you will have to use getenv_f()
4631 until then to read environment variables.
4633 The environment is protected by a CRC32 checksum. Before the monitor
4634 is relocated into RAM, as a result of a bad CRC you will be working
4635 with the compiled-in default environment - *silently*!!! [This is
4636 necessary, because the first environment variable we need is the
4637 "baudrate" setting for the console - if we have a bad CRC, we don't
4638 have any device yet where we could complain.]
4640 Note: once the monitor has been relocated, then it will complain if
4641 the default environment is used; a new CRC is computed as soon as you
4642 use the "saveenv" command to store a valid environment.
4644 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4645 Echo the inverted Ethernet link state to the fault LED.
4647 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4648 also needs to be defined.
4650 - CONFIG_SYS_FAULT_MII_ADDR:
4651 MII address of the PHY to check for the Ethernet link state.
4653 - CONFIG_NS16550_MIN_FUNCTIONS:
4654 Define this if you desire to only have use of the NS16550_init
4655 and NS16550_putc functions for the serial driver located at
4656 drivers/serial/ns16550.c. This option is useful for saving
4657 space for already greatly restricted images, including but not
4658 limited to NAND_SPL configurations.
4660 - CONFIG_DISPLAY_BOARDINFO
4661 Display information about the board that U-Boot is running on
4662 when U-Boot starts up. The board function checkboard() is called
4665 - CONFIG_DISPLAY_BOARDINFO_LATE
4666 Similar to the previous option, but display this information
4667 later, once stdio is running and output goes to the LCD, if
4670 - CONFIG_BOARD_SIZE_LIMIT:
4671 Maximum size of the U-Boot image. When defined, the
4672 build system checks that the actual size does not
4675 Low Level (hardware related) configuration options:
4676 ---------------------------------------------------
4678 - CONFIG_SYS_CACHELINE_SIZE:
4679 Cache Line Size of the CPU.
4681 - CONFIG_SYS_DEFAULT_IMMR:
4682 Default address of the IMMR after system reset.
4684 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4685 and RPXsuper) to be able to adjust the position of
4686 the IMMR register after a reset.
4688 - CONFIG_SYS_CCSRBAR_DEFAULT:
4689 Default (power-on reset) physical address of CCSR on Freescale
4692 - CONFIG_SYS_CCSRBAR:
4693 Virtual address of CCSR. On a 32-bit build, this is typically
4694 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4696 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4697 for cross-platform code that uses that macro instead.
4699 - CONFIG_SYS_CCSRBAR_PHYS:
4700 Physical address of CCSR. CCSR can be relocated to a new
4701 physical address, if desired. In this case, this macro should
4702 be set to that address. Otherwise, it should be set to the
4703 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4704 is typically relocated on 36-bit builds. It is recommended
4705 that this macro be defined via the _HIGH and _LOW macros:
4707 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4708 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4710 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4711 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4712 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4713 used in assembly code, so it must not contain typecasts or
4714 integer size suffixes (e.g. "ULL").
4716 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4717 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4718 used in assembly code, so it must not contain typecasts or
4719 integer size suffixes (e.g. "ULL").
4721 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4722 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4723 forced to a value that ensures that CCSR is not relocated.
4725 - Floppy Disk Support:
4726 CONFIG_SYS_FDC_DRIVE_NUMBER
4728 the default drive number (default value 0)
4730 CONFIG_SYS_ISA_IO_STRIDE
4732 defines the spacing between FDC chipset registers
4735 CONFIG_SYS_ISA_IO_OFFSET
4737 defines the offset of register from address. It
4738 depends on which part of the data bus is connected to
4739 the FDC chipset. (default value 0)
4741 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4742 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4745 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4746 fdc_hw_init() is called at the beginning of the FDC
4747 setup. fdc_hw_init() must be provided by the board
4748 source code. It is used to make hardware-dependent
4752 Most IDE controllers were designed to be connected with PCI
4753 interface. Only few of them were designed for AHB interface.
4754 When software is doing ATA command and data transfer to
4755 IDE devices through IDE-AHB controller, some additional
4756 registers accessing to these kind of IDE-AHB controller
4759 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4760 DO NOT CHANGE unless you know exactly what you're
4761 doing! (11-4) [MPC8xx/82xx systems only]
4763 - CONFIG_SYS_INIT_RAM_ADDR:
4765 Start address of memory area that can be used for
4766 initial data and stack; please note that this must be
4767 writable memory that is working WITHOUT special
4768 initialization, i. e. you CANNOT use normal RAM which
4769 will become available only after programming the
4770 memory controller and running certain initialization
4773 U-Boot uses the following memory types:
4774 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4775 - MPC824X: data cache
4776 - PPC4xx: data cache
4778 - CONFIG_SYS_GBL_DATA_OFFSET:
4780 Offset of the initial data structure in the memory
4781 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4782 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4783 data is located at the end of the available space
4784 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4785 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4786 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4787 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4790 On the MPC824X (or other systems that use the data
4791 cache for initial memory) the address chosen for
4792 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4793 point to an otherwise UNUSED address space between
4794 the top of RAM and the start of the PCI space.
4796 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4798 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4800 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4802 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4804 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4806 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4808 - CONFIG_SYS_OR_TIMING_SDRAM:
4811 - CONFIG_SYS_MAMR_PTA:
4812 periodic timer for refresh
4814 - CONFIG_SYS_DER: Debug Event Register (37-47)
4816 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4817 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4818 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4819 CONFIG_SYS_BR1_PRELIM:
4820 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4822 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4823 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4824 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4825 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4827 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4828 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4829 Machine Mode Register and Memory Periodic Timer
4830 Prescaler definitions (SDRAM timing)
4832 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4833 enable I2C microcode relocation patch (MPC8xx);
4834 define relocation offset in DPRAM [DSP2]
4836 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4837 enable SMC microcode relocation patch (MPC8xx);
4838 define relocation offset in DPRAM [SMC1]
4840 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4841 enable SPI microcode relocation patch (MPC8xx);
4842 define relocation offset in DPRAM [SCC4]
4844 - CONFIG_SYS_USE_OSCCLK:
4845 Use OSCM clock mode on MBX8xx board. Be careful,
4846 wrong setting might damage your board. Read
4847 doc/README.MBX before setting this variable!
4849 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4850 Offset of the bootmode word in DPRAM used by post
4851 (Power On Self Tests). This definition overrides
4852 #define'd default value in commproc.h resp.
4855 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4856 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4857 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4858 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4859 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4860 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4861 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4862 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4863 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4865 - CONFIG_PCI_DISABLE_PCIE:
4866 Disable PCI-Express on systems where it is supported but not
4869 - CONFIG_PCI_ENUM_ONLY
4870 Only scan through and get the devices on the buses.
4871 Don't do any setup work, presumably because someone or
4872 something has already done it, and we don't need to do it
4873 a second time. Useful for platforms that are pre-booted
4874 by coreboot or similar.
4876 - CONFIG_PCI_INDIRECT_BRIDGE:
4877 Enable support for indirect PCI bridges.
4880 Chip has SRIO or not
4883 Board has SRIO 1 port available
4886 Board has SRIO 2 port available
4888 - CONFIG_SRIO_PCIE_BOOT_MASTER
4889 Board can support master function for Boot from SRIO and PCIE
4891 - CONFIG_SYS_SRIOn_MEM_VIRT:
4892 Virtual Address of SRIO port 'n' memory region
4894 - CONFIG_SYS_SRIOn_MEM_PHYS:
4895 Physical Address of SRIO port 'n' memory region
4897 - CONFIG_SYS_SRIOn_MEM_SIZE:
4898 Size of SRIO port 'n' memory region
4900 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4901 Defined to tell the NAND controller that the NAND chip is using
4903 Not all NAND drivers use this symbol.
4904 Example of drivers that use it:
4905 - drivers/mtd/nand/ndfc.c
4906 - drivers/mtd/nand/mxc_nand.c
4908 - CONFIG_SYS_NDFC_EBC0_CFG
4909 Sets the EBC0_CFG register for the NDFC. If not defined
4910 a default value will be used.
4913 Get DDR timing information from an I2C EEPROM. Common
4914 with pluggable memory modules such as SODIMMs
4917 I2C address of the SPD EEPROM
4919 - CONFIG_SYS_SPD_BUS_NUM
4920 If SPD EEPROM is on an I2C bus other than the first
4921 one, specify here. Note that the value must resolve
4922 to something your driver can deal with.
4924 - CONFIG_SYS_DDR_RAW_TIMING
4925 Get DDR timing information from other than SPD. Common with
4926 soldered DDR chips onboard without SPD. DDR raw timing
4927 parameters are extracted from datasheet and hard-coded into
4928 header files or board specific files.
4930 - CONFIG_FSL_DDR_INTERACTIVE
4931 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4933 - CONFIG_SYS_83XX_DDR_USES_CS0
4934 Only for 83xx systems. If specified, then DDR should
4935 be configured using CS0 and CS1 instead of CS2 and CS3.
4937 - CONFIG_ETHER_ON_FEC[12]
4938 Define to enable FEC[12] on a 8xx series processor.
4940 - CONFIG_FEC[12]_PHY
4941 Define to the hardcoded PHY address which corresponds
4942 to the given FEC; i. e.
4943 #define CONFIG_FEC1_PHY 4
4944 means that the PHY with address 4 is connected to FEC1
4946 When set to -1, means to probe for first available.
4948 - CONFIG_FEC[12]_PHY_NORXERR
4949 The PHY does not have a RXERR line (RMII only).
4950 (so program the FEC to ignore it).
4953 Enable RMII mode for all FECs.
4954 Note that this is a global option, we can't
4955 have one FEC in standard MII mode and another in RMII mode.
4957 - CONFIG_CRC32_VERIFY
4958 Add a verify option to the crc32 command.
4961 => crc32 -v <address> <count> <crc32>
4963 Where address/count indicate a memory area
4964 and crc32 is the correct crc32 which the
4968 Add the "loopw" memory command. This only takes effect if
4969 the memory commands are activated globally (CONFIG_CMD_MEM).
4972 Add the "mdc" and "mwc" memory commands. These are cyclic
4977 This command will print 4 bytes (10,11,12,13) each 500 ms.
4979 => mwc.l 100 12345678 10
4980 This command will write 12345678 to address 100 all 10 ms.
4982 This only takes effect if the memory commands are activated
4983 globally (CONFIG_CMD_MEM).
4985 - CONFIG_SKIP_LOWLEVEL_INIT
4986 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4987 low level initializations (like setting up the memory
4988 controller) are omitted and/or U-Boot does not
4989 relocate itself into RAM.
4991 Normally this variable MUST NOT be defined. The only
4992 exception is when U-Boot is loaded (to RAM) by some
4993 other boot loader or by a debugger which performs
4994 these initializations itself.
4997 Modifies the behaviour of start.S when compiling a loader
4998 that is executed before the actual U-Boot. E.g. when
4999 compiling a NAND SPL.
5002 Modifies the behaviour of start.S when compiling a loader
5003 that is executed after the SPL and before the actual U-Boot.
5004 It is loaded by the SPL.
5006 - CONFIG_SYS_MPC85XX_NO_RESETVEC
5007 Only for 85xx systems. If this variable is specified, the section
5008 .resetvec is not kept and the section .bootpg is placed in the
5009 previous 4k of the .text section.
5011 - CONFIG_ARCH_MAP_SYSMEM
5012 Generally U-Boot (and in particular the md command) uses
5013 effective address. It is therefore not necessary to regard
5014 U-Boot address as virtual addresses that need to be translated
5015 to physical addresses. However, sandbox requires this, since
5016 it maintains its own little RAM buffer which contains all
5017 addressable memory. This option causes some memory accesses
5018 to be mapped through map_sysmem() / unmap_sysmem().
5020 - CONFIG_USE_ARCH_MEMCPY
5021 CONFIG_USE_ARCH_MEMSET
5022 If these options are used a optimized version of memcpy/memset will
5023 be used if available. These functions may be faster under some
5024 conditions but may increase the binary size.
5026 - CONFIG_X86_RESET_VECTOR
5027 If defined, the x86 reset vector code is included. This is not
5028 needed when U-Boot is running from Coreboot.
5031 Defines the MPU clock speed (in MHz).
5033 NOTE : currently only supported on AM335x platforms.
5035 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5036 Enables the RTC32K OSC on AM33xx based plattforms
5038 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5039 Option to disable subpage write in NAND driver
5040 driver that uses this:
5041 drivers/mtd/nand/davinci_nand.c
5043 Freescale QE/FMAN Firmware Support:
5044 -----------------------------------
5046 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5047 loading of "firmware", which is encoded in the QE firmware binary format.
5048 This firmware often needs to be loaded during U-Boot booting, so macros
5049 are used to identify the storage device (NOR flash, SPI, etc) and the address
5052 - CONFIG_SYS_FMAN_FW_ADDR
5053 The address in the storage device where the FMAN microcode is located. The
5054 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5057 - CONFIG_SYS_QE_FW_ADDR
5058 The address in the storage device where the QE microcode is located. The
5059 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5062 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5063 The maximum possible size of the firmware. The firmware binary format
5064 has a field that specifies the actual size of the firmware, but it
5065 might not be possible to read any part of the firmware unless some
5066 local storage is allocated to hold the entire firmware first.
5068 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5069 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5070 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5071 virtual address in NOR flash.
5073 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5074 Specifies that QE/FMAN firmware is located in NAND flash.
5075 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5077 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5078 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5079 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5081 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5082 Specifies that QE/FMAN firmware is located on the primary SPI
5083 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5085 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5086 Specifies that QE/FMAN firmware is located in the remote (master)
5087 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5088 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5089 window->master inbound window->master LAW->the ucode address in
5090 master's memory space.
5092 Freescale Layerscape Management Complex Firmware Support:
5093 ---------------------------------------------------------
5094 The Freescale Layerscape Management Complex (MC) supports the loading of
5096 This firmware often needs to be loaded during U-Boot booting, so macros
5097 are used to identify the storage device (NOR flash, SPI, etc) and the address
5100 - CONFIG_FSL_MC_ENET
5101 Enable the MC driver for Layerscape SoCs.
5103 - CONFIG_SYS_LS_MC_FW_ADDR
5104 The address in the storage device where the firmware is located. The
5105 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5108 - CONFIG_SYS_LS_MC_FW_LENGTH
5109 The maximum possible size of the firmware. The firmware binary format
5110 has a field that specifies the actual size of the firmware, but it
5111 might not be possible to read any part of the firmware unless some
5112 local storage is allocated to hold the entire firmware first.
5114 - CONFIG_SYS_LS_MC_FW_IN_NOR
5115 Specifies that MC firmware is located in NOR flash, mapped as
5116 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5117 virtual address in NOR flash.
5119 Building the Software:
5120 ======================
5122 Building U-Boot has been tested in several native build environments
5123 and in many different cross environments. Of course we cannot support
5124 all possibly existing versions of cross development tools in all
5125 (potentially obsolete) versions. In case of tool chain problems we
5126 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5127 which is extensively used to build and test U-Boot.
5129 If you are not using a native environment, it is assumed that you
5130 have GNU cross compiling tools available in your path. In this case,
5131 you must set the environment variable CROSS_COMPILE in your shell.
5132 Note that no changes to the Makefile or any other source files are
5133 necessary. For example using the ELDK on a 4xx CPU, please enter:
5135 $ CROSS_COMPILE=ppc_4xx-
5136 $ export CROSS_COMPILE
5138 Note: If you wish to generate Windows versions of the utilities in
5139 the tools directory you can use the MinGW toolchain
5140 (http://www.mingw.org). Set your HOST tools to the MinGW
5141 toolchain and execute 'make tools'. For example:
5143 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5145 Binaries such as tools/mkimage.exe will be created which can
5146 be executed on computers running Windows.
5148 U-Boot is intended to be simple to build. After installing the
5149 sources you must configure U-Boot for one specific board type. This
5154 where "NAME_defconfig" is the name of one of the existing configu-
5155 rations; see boards.cfg for supported names.
5157 Note: for some board special configuration names may exist; check if
5158 additional information is available from the board vendor; for
5159 instance, the TQM823L systems are available without (standard)
5160 or with LCD support. You can select such additional "features"
5161 when choosing the configuration, i. e.
5163 make TQM823L_defconfig
5164 - will configure for a plain TQM823L, i. e. no LCD support
5166 make TQM823L_LCD_defconfig
5167 - will configure for a TQM823L with U-Boot console on LCD
5172 Finally, type "make all", and you should get some working U-Boot
5173 images ready for download to / installation on your system:
5175 - "u-boot.bin" is a raw binary image
5176 - "u-boot" is an image in ELF binary format
5177 - "u-boot.srec" is in Motorola S-Record format
5179 By default the build is performed locally and the objects are saved
5180 in the source directory. One of the two methods can be used to change
5181 this behavior and build U-Boot to some external directory:
5183 1. Add O= to the make command line invocations:
5185 make O=/tmp/build distclean
5186 make O=/tmp/build NAME_defconfig
5187 make O=/tmp/build all
5189 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5191 export KBUILD_OUTPUT=/tmp/build
5196 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5200 Please be aware that the Makefiles assume you are using GNU make, so
5201 for instance on NetBSD you might need to use "gmake" instead of
5205 If the system board that you have is not listed, then you will need
5206 to port U-Boot to your hardware platform. To do this, follow these
5209 1. Add a new configuration option for your board to the toplevel
5210 "boards.cfg" file, using the existing entries as examples.
5211 Follow the instructions there to keep the boards in order.
5212 2. Create a new directory to hold your board specific code. Add any
5213 files you need. In your board directory, you will need at least
5214 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5215 3. Create a new configuration file "include/configs/<board>.h" for
5217 3. If you're porting U-Boot to a new CPU, then also create a new
5218 directory to hold your CPU specific code. Add any files you need.
5219 4. Run "make <board>_defconfig" with your new name.
5220 5. Type "make", and you should get a working "u-boot.srec" file
5221 to be installed on your target system.
5222 6. Debug and solve any problems that might arise.
5223 [Of course, this last step is much harder than it sounds.]
5226 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5227 ==============================================================
5229 If you have modified U-Boot sources (for instance added a new board
5230 or support for new devices, a new CPU, etc.) you are expected to
5231 provide feedback to the other developers. The feedback normally takes
5232 the form of a "patch", i. e. a context diff against a certain (latest
5233 official or latest in the git repository) version of U-Boot sources.
5235 But before you submit such a patch, please verify that your modifi-
5236 cation did not break existing code. At least make sure that *ALL* of
5237 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5238 just run the "MAKEALL" script, which will configure and build U-Boot
5239 for ALL supported system. Be warned, this will take a while. You can
5240 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5241 environment variable to the script, i. e. to use the ELDK cross tools
5244 CROSS_COMPILE=ppc_8xx- MAKEALL
5246 or to build on a native PowerPC system you can type
5248 CROSS_COMPILE=' ' MAKEALL
5250 When using the MAKEALL script, the default behaviour is to build
5251 U-Boot in the source directory. This location can be changed by
5252 setting the BUILD_DIR environment variable. Also, for each target
5253 built, the MAKEALL script saves two log files (<target>.ERR and
5254 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5255 location can be changed by setting the MAKEALL_LOGDIR environment
5256 variable. For example:
5258 export BUILD_DIR=/tmp/build
5259 export MAKEALL_LOGDIR=/tmp/log
5260 CROSS_COMPILE=ppc_8xx- MAKEALL
5262 With the above settings build objects are saved in the /tmp/build,
5263 log files are saved in the /tmp/log and the source tree remains clean
5264 during the whole build process.
5267 See also "U-Boot Porting Guide" below.
5270 Monitor Commands - Overview:
5271 ============================
5273 go - start application at address 'addr'
5274 run - run commands in an environment variable
5275 bootm - boot application image from memory
5276 bootp - boot image via network using BootP/TFTP protocol
5277 bootz - boot zImage from memory
5278 tftpboot- boot image via network using TFTP protocol
5279 and env variables "ipaddr" and "serverip"
5280 (and eventually "gatewayip")
5281 tftpput - upload a file via network using TFTP protocol
5282 rarpboot- boot image via network using RARP/TFTP protocol
5283 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5284 loads - load S-Record file over serial line
5285 loadb - load binary file over serial line (kermit mode)
5287 mm - memory modify (auto-incrementing)
5288 nm - memory modify (constant address)
5289 mw - memory write (fill)
5291 cmp - memory compare
5292 crc32 - checksum calculation
5293 i2c - I2C sub-system
5294 sspi - SPI utility commands
5295 base - print or set address offset
5296 printenv- print environment variables
5297 setenv - set environment variables
5298 saveenv - save environment variables to persistent storage
5299 protect - enable or disable FLASH write protection
5300 erase - erase FLASH memory
5301 flinfo - print FLASH memory information
5302 nand - NAND memory operations (see doc/README.nand)
5303 bdinfo - print Board Info structure
5304 iminfo - print header information for application image
5305 coninfo - print console devices and informations
5306 ide - IDE sub-system
5307 loop - infinite loop on address range
5308 loopw - infinite write loop on address range
5309 mtest - simple RAM test
5310 icache - enable or disable instruction cache
5311 dcache - enable or disable data cache
5312 reset - Perform RESET of the CPU
5313 echo - echo args to console
5314 version - print monitor version
5315 help - print online help
5316 ? - alias for 'help'
5319 Monitor Commands - Detailed Description:
5320 ========================================
5324 For now: just type "help <command>".
5327 Environment Variables:
5328 ======================
5330 U-Boot supports user configuration using Environment Variables which
5331 can be made persistent by saving to Flash memory.
5333 Environment Variables are set using "setenv", printed using
5334 "printenv", and saved to Flash using "saveenv". Using "setenv"
5335 without a value can be used to delete a variable from the
5336 environment. As long as you don't save the environment you are
5337 working with an in-memory copy. In case the Flash area containing the
5338 environment is erased by accident, a default environment is provided.
5340 Some configuration options can be set using Environment Variables.
5342 List of environment variables (most likely not complete):
5344 baudrate - see CONFIG_BAUDRATE
5346 bootdelay - see CONFIG_BOOTDELAY
5348 bootcmd - see CONFIG_BOOTCOMMAND
5350 bootargs - Boot arguments when booting an RTOS image
5352 bootfile - Name of the image to load with TFTP
5354 bootm_low - Memory range available for image processing in the bootm
5355 command can be restricted. This variable is given as
5356 a hexadecimal number and defines lowest address allowed
5357 for use by the bootm command. See also "bootm_size"
5358 environment variable. Address defined by "bootm_low" is
5359 also the base of the initial memory mapping for the Linux
5360 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5363 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5364 This variable is given as a hexadecimal number and it
5365 defines the size of the memory region starting at base
5366 address bootm_low that is accessible by the Linux kernel
5367 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5368 as the default value if it is defined, and bootm_size is
5371 bootm_size - Memory range available for image processing in the bootm
5372 command can be restricted. This variable is given as
5373 a hexadecimal number and defines the size of the region
5374 allowed for use by the bootm command. See also "bootm_low"
5375 environment variable.
5377 updatefile - Location of the software update file on a TFTP server, used
5378 by the automatic software update feature. Please refer to
5379 documentation in doc/README.update for more details.
5381 autoload - if set to "no" (any string beginning with 'n'),
5382 "bootp" will just load perform a lookup of the
5383 configuration from the BOOTP server, but not try to
5384 load any image using TFTP
5386 autostart - if set to "yes", an image loaded using the "bootp",
5387 "rarpboot", "tftpboot" or "diskboot" commands will
5388 be automatically started (by internally calling
5391 If set to "no", a standalone image passed to the
5392 "bootm" command will be copied to the load address
5393 (and eventually uncompressed), but NOT be started.
5394 This can be used to load and uncompress arbitrary
5397 fdt_high - if set this restricts the maximum address that the
5398 flattened device tree will be copied into upon boot.
5399 For example, if you have a system with 1 GB memory
5400 at physical address 0x10000000, while Linux kernel
5401 only recognizes the first 704 MB as low memory, you
5402 may need to set fdt_high as 0x3C000000 to have the
5403 device tree blob be copied to the maximum address
5404 of the 704 MB low memory, so that Linux kernel can
5405 access it during the boot procedure.
5407 If this is set to the special value 0xFFFFFFFF then
5408 the fdt will not be copied at all on boot. For this
5409 to work it must reside in writable memory, have
5410 sufficient padding on the end of it for u-boot to
5411 add the information it needs into it, and the memory
5412 must be accessible by the kernel.
5414 fdtcontroladdr- if set this is the address of the control flattened
5415 device tree used by U-Boot when CONFIG_OF_CONTROL is
5418 i2cfast - (PPC405GP|PPC405EP only)
5419 if set to 'y' configures Linux I2C driver for fast
5420 mode (400kHZ). This environment variable is used in
5421 initialization code. So, for changes to be effective
5422 it must be saved and board must be reset.
5424 initrd_high - restrict positioning of initrd images:
5425 If this variable is not set, initrd images will be
5426 copied to the highest possible address in RAM; this
5427 is usually what you want since it allows for
5428 maximum initrd size. If for some reason you want to
5429 make sure that the initrd image is loaded below the
5430 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5431 variable to a value of "no" or "off" or "0".
5432 Alternatively, you can set it to a maximum upper
5433 address to use (U-Boot will still check that it
5434 does not overwrite the U-Boot stack and data).
5436 For instance, when you have a system with 16 MB
5437 RAM, and want to reserve 4 MB from use by Linux,
5438 you can do this by adding "mem=12M" to the value of
5439 the "bootargs" variable. However, now you must make
5440 sure that the initrd image is placed in the first
5441 12 MB as well - this can be done with
5443 setenv initrd_high 00c00000
5445 If you set initrd_high to 0xFFFFFFFF, this is an
5446 indication to U-Boot that all addresses are legal
5447 for the Linux kernel, including addresses in flash
5448 memory. In this case U-Boot will NOT COPY the
5449 ramdisk at all. This may be useful to reduce the
5450 boot time on your system, but requires that this
5451 feature is supported by your Linux kernel.
5453 ipaddr - IP address; needed for tftpboot command
5455 loadaddr - Default load address for commands like "bootp",
5456 "rarpboot", "tftpboot", "loadb" or "diskboot"
5458 loads_echo - see CONFIG_LOADS_ECHO
5460 serverip - TFTP server IP address; needed for tftpboot command
5462 bootretry - see CONFIG_BOOT_RETRY_TIME
5464 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5466 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5468 ethprime - controls which interface is used first.
5470 ethact - controls which interface is currently active.
5471 For example you can do the following
5473 => setenv ethact FEC
5474 => ping 192.168.0.1 # traffic sent on FEC
5475 => setenv ethact SCC
5476 => ping 10.0.0.1 # traffic sent on SCC
5478 ethrotate - When set to "no" U-Boot does not go through all
5479 available network interfaces.
5480 It just stays at the currently selected interface.
5482 netretry - When set to "no" each network operation will
5483 either succeed or fail without retrying.
5484 When set to "once" the network operation will
5485 fail when all the available network interfaces
5486 are tried once without success.
5487 Useful on scripts which control the retry operation
5490 npe_ucode - set load address for the NPE microcode
5492 silent_linux - If set then Linux will be told to boot silently, by
5493 changing the console to be empty. If "yes" it will be
5494 made silent. If "no" it will not be made silent. If
5495 unset, then it will be made silent if the U-Boot console
5498 tftpsrcport - If this is set, the value is used for TFTP's
5501 tftpdstport - If this is set, the value is used for TFTP's UDP
5502 destination port instead of the Well Know Port 69.
5504 tftpblocksize - Block size to use for TFTP transfers; if not set,
5505 we use the TFTP server's default block size
5507 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5508 seconds, minimum value is 1000 = 1 second). Defines
5509 when a packet is considered to be lost so it has to
5510 be retransmitted. The default is 5000 = 5 seconds.
5511 Lowering this value may make downloads succeed
5512 faster in networks with high packet loss rates or
5513 with unreliable TFTP servers.
5515 vlan - When set to a value < 4095 the traffic over
5516 Ethernet is encapsulated/received over 802.1q
5519 The following image location variables contain the location of images
5520 used in booting. The "Image" column gives the role of the image and is
5521 not an environment variable name. The other columns are environment
5522 variable names. "File Name" gives the name of the file on a TFTP
5523 server, "RAM Address" gives the location in RAM the image will be
5524 loaded to, and "Flash Location" gives the image's address in NOR
5525 flash or offset in NAND flash.
5527 *Note* - these variables don't have to be defined for all boards, some
5528 boards currenlty use other variables for these purposes, and some
5529 boards use these variables for other purposes.
5531 Image File Name RAM Address Flash Location
5532 ----- --------- ----------- --------------
5533 u-boot u-boot u-boot_addr_r u-boot_addr
5534 Linux kernel bootfile kernel_addr_r kernel_addr
5535 device tree blob fdtfile fdt_addr_r fdt_addr
5536 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5538 The following environment variables may be used and automatically
5539 updated by the network boot commands ("bootp" and "rarpboot"),
5540 depending the information provided by your boot server:
5542 bootfile - see above
5543 dnsip - IP address of your Domain Name Server
5544 dnsip2 - IP address of your secondary Domain Name Server
5545 gatewayip - IP address of the Gateway (Router) to use
5546 hostname - Target hostname
5548 netmask - Subnet Mask
5549 rootpath - Pathname of the root filesystem on the NFS server
5550 serverip - see above
5553 There are two special Environment Variables:
5555 serial# - contains hardware identification information such
5556 as type string and/or serial number
5557 ethaddr - Ethernet address
5559 These variables can be set only once (usually during manufacturing of
5560 the board). U-Boot refuses to delete or overwrite these variables
5561 once they have been set once.
5564 Further special Environment Variables:
5566 ver - Contains the U-Boot version string as printed
5567 with the "version" command. This variable is
5568 readonly (see CONFIG_VERSION_VARIABLE).
5571 Please note that changes to some configuration parameters may take
5572 only effect after the next boot (yes, that's just like Windoze :-).
5575 Callback functions for environment variables:
5576 ---------------------------------------------
5578 For some environment variables, the behavior of u-boot needs to change
5579 when their values are changed. This functionality allows functions to
5580 be associated with arbitrary variables. On creation, overwrite, or
5581 deletion, the callback will provide the opportunity for some side
5582 effect to happen or for the change to be rejected.
5584 The callbacks are named and associated with a function using the
5585 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5587 These callbacks are associated with variables in one of two ways. The
5588 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5589 in the board configuration to a string that defines a list of
5590 associations. The list must be in the following format:
5592 entry = variable_name[:callback_name]
5595 If the callback name is not specified, then the callback is deleted.
5596 Spaces are also allowed anywhere in the list.
5598 Callbacks can also be associated by defining the ".callbacks" variable
5599 with the same list format above. Any association in ".callbacks" will
5600 override any association in the static list. You can define
5601 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5602 ".callbacks" environment variable in the default or embedded environment.
5605 Command Line Parsing:
5606 =====================
5608 There are two different command line parsers available with U-Boot:
5609 the old "simple" one, and the much more powerful "hush" shell:
5611 Old, simple command line parser:
5612 --------------------------------
5614 - supports environment variables (through setenv / saveenv commands)
5615 - several commands on one line, separated by ';'
5616 - variable substitution using "... ${name} ..." syntax
5617 - special characters ('$', ';') can be escaped by prefixing with '\',
5619 setenv bootcmd bootm \${address}
5620 - You can also escape text by enclosing in single apostrophes, for example:
5621 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5626 - similar to Bourne shell, with control structures like
5627 if...then...else...fi, for...do...done; while...do...done,
5628 until...do...done, ...
5629 - supports environment ("global") variables (through setenv / saveenv
5630 commands) and local shell variables (through standard shell syntax
5631 "name=value"); only environment variables can be used with "run"
5637 (1) If a command line (or an environment variable executed by a "run"
5638 command) contains several commands separated by semicolon, and
5639 one of these commands fails, then the remaining commands will be
5642 (2) If you execute several variables with one call to run (i. e.
5643 calling run with a list of variables as arguments), any failing
5644 command will cause "run" to terminate, i. e. the remaining
5645 variables are not executed.
5647 Note for Redundant Ethernet Interfaces:
5648 =======================================
5650 Some boards come with redundant Ethernet interfaces; U-Boot supports
5651 such configurations and is capable of automatic selection of a
5652 "working" interface when needed. MAC assignment works as follows:
5654 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5655 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5656 "eth1addr" (=>eth1), "eth2addr", ...
5658 If the network interface stores some valid MAC address (for instance
5659 in SROM), this is used as default address if there is NO correspon-
5660 ding setting in the environment; if the corresponding environment
5661 variable is set, this overrides the settings in the card; that means:
5663 o If the SROM has a valid MAC address, and there is no address in the
5664 environment, the SROM's address is used.
5666 o If there is no valid address in the SROM, and a definition in the
5667 environment exists, then the value from the environment variable is
5670 o If both the SROM and the environment contain a MAC address, and
5671 both addresses are the same, this MAC address is used.
5673 o If both the SROM and the environment contain a MAC address, and the
5674 addresses differ, the value from the environment is used and a
5677 o If neither SROM nor the environment contain a MAC address, an error
5680 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5681 will be programmed into hardware as part of the initialization process. This
5682 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5683 The naming convention is as follows:
5684 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5689 U-Boot is capable of booting (and performing other auxiliary operations on)
5690 images in two formats:
5692 New uImage format (FIT)
5693 -----------------------
5695 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5696 to Flattened Device Tree). It allows the use of images with multiple
5697 components (several kernels, ramdisks, etc.), with contents protected by
5698 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5704 Old image format is based on binary files which can be basically anything,
5705 preceded by a special header; see the definitions in include/image.h for
5706 details; basically, the header defines the following image properties:
5708 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5709 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5710 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5711 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5713 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5714 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5715 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5716 * Compression Type (uncompressed, gzip, bzip2)
5722 The header is marked by a special Magic Number, and both the header
5723 and the data portions of the image are secured against corruption by
5730 Although U-Boot should support any OS or standalone application
5731 easily, the main focus has always been on Linux during the design of
5734 U-Boot includes many features that so far have been part of some
5735 special "boot loader" code within the Linux kernel. Also, any
5736 "initrd" images to be used are no longer part of one big Linux image;
5737 instead, kernel and "initrd" are separate images. This implementation
5738 serves several purposes:
5740 - the same features can be used for other OS or standalone
5741 applications (for instance: using compressed images to reduce the
5742 Flash memory footprint)
5744 - it becomes much easier to port new Linux kernel versions because
5745 lots of low-level, hardware dependent stuff are done by U-Boot
5747 - the same Linux kernel image can now be used with different "initrd"
5748 images; of course this also means that different kernel images can
5749 be run with the same "initrd". This makes testing easier (you don't
5750 have to build a new "zImage.initrd" Linux image when you just
5751 change a file in your "initrd"). Also, a field-upgrade of the
5752 software is easier now.
5758 Porting Linux to U-Boot based systems:
5759 ---------------------------------------
5761 U-Boot cannot save you from doing all the necessary modifications to
5762 configure the Linux device drivers for use with your target hardware
5763 (no, we don't intend to provide a full virtual machine interface to
5766 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5768 Just make sure your machine specific header file (for instance
5769 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5770 Information structure as we define in include/asm-<arch>/u-boot.h,
5771 and make sure that your definition of IMAP_ADDR uses the same value
5772 as your U-Boot configuration in CONFIG_SYS_IMMR.
5774 Note that U-Boot now has a driver model, a unified model for drivers.
5775 If you are adding a new driver, plumb it into driver model. If there
5776 is no uclass available, you are encouraged to create one. See
5780 Configuring the Linux kernel:
5781 -----------------------------
5783 No specific requirements for U-Boot. Make sure you have some root
5784 device (initial ramdisk, NFS) for your target system.
5787 Building a Linux Image:
5788 -----------------------
5790 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5791 not used. If you use recent kernel source, a new build target
5792 "uImage" will exist which automatically builds an image usable by
5793 U-Boot. Most older kernels also have support for a "pImage" target,
5794 which was introduced for our predecessor project PPCBoot and uses a
5795 100% compatible format.
5799 make TQM850L_defconfig
5804 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5805 encapsulate a compressed Linux kernel image with header information,
5806 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5808 * build a standard "vmlinux" kernel image (in ELF binary format):
5810 * convert the kernel into a raw binary image:
5812 ${CROSS_COMPILE}-objcopy -O binary \
5813 -R .note -R .comment \
5814 -S vmlinux linux.bin
5816 * compress the binary image:
5820 * package compressed binary image for U-Boot:
5822 mkimage -A ppc -O linux -T kernel -C gzip \
5823 -a 0 -e 0 -n "Linux Kernel Image" \
5824 -d linux.bin.gz uImage
5827 The "mkimage" tool can also be used to create ramdisk images for use
5828 with U-Boot, either separated from the Linux kernel image, or
5829 combined into one file. "mkimage" encapsulates the images with a 64
5830 byte header containing information about target architecture,
5831 operating system, image type, compression method, entry points, time
5832 stamp, CRC32 checksums, etc.
5834 "mkimage" can be called in two ways: to verify existing images and
5835 print the header information, or to build new images.
5837 In the first form (with "-l" option) mkimage lists the information
5838 contained in the header of an existing U-Boot image; this includes
5839 checksum verification:
5841 tools/mkimage -l image
5842 -l ==> list image header information
5844 The second form (with "-d" option) is used to build a U-Boot image
5845 from a "data file" which is used as image payload:
5847 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5848 -n name -d data_file image
5849 -A ==> set architecture to 'arch'
5850 -O ==> set operating system to 'os'
5851 -T ==> set image type to 'type'
5852 -C ==> set compression type 'comp'
5853 -a ==> set load address to 'addr' (hex)
5854 -e ==> set entry point to 'ep' (hex)
5855 -n ==> set image name to 'name'
5856 -d ==> use image data from 'datafile'
5858 Right now, all Linux kernels for PowerPC systems use the same load
5859 address (0x00000000), but the entry point address depends on the
5862 - 2.2.x kernels have the entry point at 0x0000000C,
5863 - 2.3.x and later kernels have the entry point at 0x00000000.
5865 So a typical call to build a U-Boot image would read:
5867 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5868 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5869 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5870 > examples/uImage.TQM850L
5871 Image Name: 2.4.4 kernel for TQM850L
5872 Created: Wed Jul 19 02:34:59 2000
5873 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5874 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5875 Load Address: 0x00000000
5876 Entry Point: 0x00000000
5878 To verify the contents of the image (or check for corruption):
5880 -> tools/mkimage -l examples/uImage.TQM850L
5881 Image Name: 2.4.4 kernel for TQM850L
5882 Created: Wed Jul 19 02:34:59 2000
5883 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5884 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5885 Load Address: 0x00000000
5886 Entry Point: 0x00000000
5888 NOTE: for embedded systems where boot time is critical you can trade
5889 speed for memory and install an UNCOMPRESSED image instead: this
5890 needs more space in Flash, but boots much faster since it does not
5891 need to be uncompressed:
5893 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5894 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5895 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5896 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5897 > examples/uImage.TQM850L-uncompressed
5898 Image Name: 2.4.4 kernel for TQM850L
5899 Created: Wed Jul 19 02:34:59 2000
5900 Image Type: PowerPC Linux Kernel Image (uncompressed)
5901 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5902 Load Address: 0x00000000
5903 Entry Point: 0x00000000
5906 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5907 when your kernel is intended to use an initial ramdisk:
5909 -> tools/mkimage -n 'Simple Ramdisk Image' \
5910 > -A ppc -O linux -T ramdisk -C gzip \
5911 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5912 Image Name: Simple Ramdisk Image
5913 Created: Wed Jan 12 14:01:50 2000
5914 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5915 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5916 Load Address: 0x00000000
5917 Entry Point: 0x00000000
5919 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5920 option performs the converse operation of the mkimage's second form (the "-d"
5921 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5924 tools/dumpimage -i image -T type -p position data_file
5925 -i ==> extract from the 'image' a specific 'data_file'
5926 -T ==> set image type to 'type'
5927 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5930 Installing a Linux Image:
5931 -------------------------
5933 To downloading a U-Boot image over the serial (console) interface,
5934 you must convert the image to S-Record format:
5936 objcopy -I binary -O srec examples/image examples/image.srec
5938 The 'objcopy' does not understand the information in the U-Boot
5939 image header, so the resulting S-Record file will be relative to
5940 address 0x00000000. To load it to a given address, you need to
5941 specify the target address as 'offset' parameter with the 'loads'
5944 Example: install the image to address 0x40100000 (which on the
5945 TQM8xxL is in the first Flash bank):
5947 => erase 40100000 401FFFFF
5953 ## Ready for S-Record download ...
5954 ~>examples/image.srec
5955 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5957 15989 15990 15991 15992
5958 [file transfer complete]
5960 ## Start Addr = 0x00000000
5963 You can check the success of the download using the 'iminfo' command;
5964 this includes a checksum verification so you can be sure no data
5965 corruption happened:
5969 ## Checking Image at 40100000 ...
5970 Image Name: 2.2.13 for initrd on TQM850L
5971 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5972 Data Size: 335725 Bytes = 327 kB = 0 MB
5973 Load Address: 00000000
5974 Entry Point: 0000000c
5975 Verifying Checksum ... OK
5981 The "bootm" command is used to boot an application that is stored in
5982 memory (RAM or Flash). In case of a Linux kernel image, the contents
5983 of the "bootargs" environment variable is passed to the kernel as
5984 parameters. You can check and modify this variable using the
5985 "printenv" and "setenv" commands:
5988 => printenv bootargs
5989 bootargs=root=/dev/ram
5991 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5993 => printenv bootargs
5994 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5997 ## Booting Linux kernel at 40020000 ...
5998 Image Name: 2.2.13 for NFS on TQM850L
5999 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6000 Data Size: 381681 Bytes = 372 kB = 0 MB
6001 Load Address: 00000000
6002 Entry Point: 0000000c
6003 Verifying Checksum ... OK
6004 Uncompressing Kernel Image ... OK
6005 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
6006 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
6007 time_init: decrementer frequency = 187500000/60
6008 Calibrating delay loop... 49.77 BogoMIPS
6009 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6012 If you want to boot a Linux kernel with initial RAM disk, you pass
6013 the memory addresses of both the kernel and the initrd image (PPBCOOT
6014 format!) to the "bootm" command:
6016 => imi 40100000 40200000
6018 ## Checking Image at 40100000 ...
6019 Image Name: 2.2.13 for initrd on TQM850L
6020 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6021 Data Size: 335725 Bytes = 327 kB = 0 MB
6022 Load Address: 00000000
6023 Entry Point: 0000000c
6024 Verifying Checksum ... OK
6026 ## Checking Image at 40200000 ...
6027 Image Name: Simple Ramdisk Image
6028 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6029 Data Size: 566530 Bytes = 553 kB = 0 MB
6030 Load Address: 00000000
6031 Entry Point: 00000000
6032 Verifying Checksum ... OK
6034 => bootm 40100000 40200000
6035 ## Booting Linux kernel at 40100000 ...
6036 Image Name: 2.2.13 for initrd on TQM850L
6037 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6038 Data Size: 335725 Bytes = 327 kB = 0 MB
6039 Load Address: 00000000
6040 Entry Point: 0000000c
6041 Verifying Checksum ... OK
6042 Uncompressing Kernel Image ... OK
6043 ## Loading RAMDisk Image at 40200000 ...
6044 Image Name: Simple Ramdisk Image
6045 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6046 Data Size: 566530 Bytes = 553 kB = 0 MB
6047 Load Address: 00000000
6048 Entry Point: 00000000
6049 Verifying Checksum ... OK
6050 Loading Ramdisk ... OK
6051 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
6052 Boot arguments: root=/dev/ram
6053 time_init: decrementer frequency = 187500000/60
6054 Calibrating delay loop... 49.77 BogoMIPS
6056 RAMDISK: Compressed image found at block 0
6057 VFS: Mounted root (ext2 filesystem).
6061 Boot Linux and pass a flat device tree:
6064 First, U-Boot must be compiled with the appropriate defines. See the section
6065 titled "Linux Kernel Interface" above for a more in depth explanation. The
6066 following is an example of how to start a kernel and pass an updated
6072 oft=oftrees/mpc8540ads.dtb
6073 => tftp $oftaddr $oft
6074 Speed: 1000, full duplex
6076 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6077 Filename 'oftrees/mpc8540ads.dtb'.
6078 Load address: 0x300000
6081 Bytes transferred = 4106 (100a hex)
6082 => tftp $loadaddr $bootfile
6083 Speed: 1000, full duplex
6085 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6087 Load address: 0x200000
6088 Loading:############
6090 Bytes transferred = 1029407 (fb51f hex)
6095 => bootm $loadaddr - $oftaddr
6096 ## Booting image at 00200000 ...
6097 Image Name: Linux-2.6.17-dirty
6098 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6099 Data Size: 1029343 Bytes = 1005.2 kB
6100 Load Address: 00000000
6101 Entry Point: 00000000
6102 Verifying Checksum ... OK
6103 Uncompressing Kernel Image ... OK
6104 Booting using flat device tree at 0x300000
6105 Using MPC85xx ADS machine description
6106 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6110 More About U-Boot Image Types:
6111 ------------------------------
6113 U-Boot supports the following image types:
6115 "Standalone Programs" are directly runnable in the environment
6116 provided by U-Boot; it is expected that (if they behave
6117 well) you can continue to work in U-Boot after return from
6118 the Standalone Program.
6119 "OS Kernel Images" are usually images of some Embedded OS which
6120 will take over control completely. Usually these programs
6121 will install their own set of exception handlers, device
6122 drivers, set up the MMU, etc. - this means, that you cannot
6123 expect to re-enter U-Boot except by resetting the CPU.
6124 "RAMDisk Images" are more or less just data blocks, and their
6125 parameters (address, size) are passed to an OS kernel that is
6127 "Multi-File Images" contain several images, typically an OS
6128 (Linux) kernel image and one or more data images like
6129 RAMDisks. This construct is useful for instance when you want
6130 to boot over the network using BOOTP etc., where the boot
6131 server provides just a single image file, but you want to get
6132 for instance an OS kernel and a RAMDisk image.
6134 "Multi-File Images" start with a list of image sizes, each
6135 image size (in bytes) specified by an "uint32_t" in network
6136 byte order. This list is terminated by an "(uint32_t)0".
6137 Immediately after the terminating 0 follow the images, one by
6138 one, all aligned on "uint32_t" boundaries (size rounded up to
6139 a multiple of 4 bytes).
6141 "Firmware Images" are binary images containing firmware (like
6142 U-Boot or FPGA images) which usually will be programmed to
6145 "Script files" are command sequences that will be executed by
6146 U-Boot's command interpreter; this feature is especially
6147 useful when you configure U-Boot to use a real shell (hush)
6148 as command interpreter.
6150 Booting the Linux zImage:
6151 -------------------------
6153 On some platforms, it's possible to boot Linux zImage. This is done
6154 using the "bootz" command. The syntax of "bootz" command is the same
6155 as the syntax of "bootm" command.
6157 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6158 kernel with raw initrd images. The syntax is slightly different, the
6159 address of the initrd must be augmented by it's size, in the following
6160 format: "<initrd addres>:<initrd size>".
6166 One of the features of U-Boot is that you can dynamically load and
6167 run "standalone" applications, which can use some resources of
6168 U-Boot like console I/O functions or interrupt services.
6170 Two simple examples are included with the sources:
6175 'examples/hello_world.c' contains a small "Hello World" Demo
6176 application; it is automatically compiled when you build U-Boot.
6177 It's configured to run at address 0x00040004, so you can play with it
6181 ## Ready for S-Record download ...
6182 ~>examples/hello_world.srec
6183 1 2 3 4 5 6 7 8 9 10 11 ...
6184 [file transfer complete]
6186 ## Start Addr = 0x00040004
6188 => go 40004 Hello World! This is a test.
6189 ## Starting application at 0x00040004 ...
6200 Hit any key to exit ...
6202 ## Application terminated, rc = 0x0
6204 Another example, which demonstrates how to register a CPM interrupt
6205 handler with the U-Boot code, can be found in 'examples/timer.c'.
6206 Here, a CPM timer is set up to generate an interrupt every second.
6207 The interrupt service routine is trivial, just printing a '.'
6208 character, but this is just a demo program. The application can be
6209 controlled by the following keys:
6211 ? - print current values og the CPM Timer registers
6212 b - enable interrupts and start timer
6213 e - stop timer and disable interrupts
6214 q - quit application
6217 ## Ready for S-Record download ...
6218 ~>examples/timer.srec
6219 1 2 3 4 5 6 7 8 9 10 11 ...
6220 [file transfer complete]
6222 ## Start Addr = 0x00040004
6225 ## Starting application at 0x00040004 ...
6228 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6231 [q, b, e, ?] Set interval 1000000 us
6234 [q, b, e, ?] ........
6235 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6238 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6241 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6244 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6246 [q, b, e, ?] ...Stopping timer
6248 [q, b, e, ?] ## Application terminated, rc = 0x0
6254 Over time, many people have reported problems when trying to use the
6255 "minicom" terminal emulation program for serial download. I (wd)
6256 consider minicom to be broken, and recommend not to use it. Under
6257 Unix, I recommend to use C-Kermit for general purpose use (and
6258 especially for kermit binary protocol download ("loadb" command), and
6259 use "cu" for S-Record download ("loads" command). See
6260 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6261 for help with kermit.
6264 Nevertheless, if you absolutely want to use it try adding this
6265 configuration to your "File transfer protocols" section:
6267 Name Program Name U/D FullScr IO-Red. Multi
6268 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6269 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6275 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6276 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6278 Building requires a cross environment; it is known to work on
6279 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6280 need gmake since the Makefiles are not compatible with BSD make).
6281 Note that the cross-powerpc package does not install include files;
6282 attempting to build U-Boot will fail because <machine/ansi.h> is
6283 missing. This file has to be installed and patched manually:
6285 # cd /usr/pkg/cross/powerpc-netbsd/include
6287 # ln -s powerpc machine
6288 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6289 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6291 Native builds *don't* work due to incompatibilities between native
6292 and U-Boot include files.
6294 Booting assumes that (the first part of) the image booted is a
6295 stage-2 loader which in turn loads and then invokes the kernel
6296 proper. Loader sources will eventually appear in the NetBSD source
6297 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6298 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6301 Implementation Internals:
6302 =========================
6304 The following is not intended to be a complete description of every
6305 implementation detail. However, it should help to understand the
6306 inner workings of U-Boot and make it easier to port it to custom
6310 Initial Stack, Global Data:
6311 ---------------------------
6313 The implementation of U-Boot is complicated by the fact that U-Boot
6314 starts running out of ROM (flash memory), usually without access to
6315 system RAM (because the memory controller is not initialized yet).
6316 This means that we don't have writable Data or BSS segments, and BSS
6317 is not initialized as zero. To be able to get a C environment working
6318 at all, we have to allocate at least a minimal stack. Implementation
6319 options for this are defined and restricted by the CPU used: Some CPU
6320 models provide on-chip memory (like the IMMR area on MPC8xx and
6321 MPC826x processors), on others (parts of) the data cache can be
6322 locked as (mis-) used as memory, etc.
6324 Chris Hallinan posted a good summary of these issues to the
6325 U-Boot mailing list:
6327 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6328 From: "Chris Hallinan" <clh@net1plus.com>
6329 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6332 Correct me if I'm wrong, folks, but the way I understand it
6333 is this: Using DCACHE as initial RAM for Stack, etc, does not
6334 require any physical RAM backing up the cache. The cleverness
6335 is that the cache is being used as a temporary supply of
6336 necessary storage before the SDRAM controller is setup. It's
6337 beyond the scope of this list to explain the details, but you
6338 can see how this works by studying the cache architecture and
6339 operation in the architecture and processor-specific manuals.
6341 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6342 is another option for the system designer to use as an
6343 initial stack/RAM area prior to SDRAM being available. Either
6344 option should work for you. Using CS 4 should be fine if your
6345 board designers haven't used it for something that would
6346 cause you grief during the initial boot! It is frequently not
6349 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6350 with your processor/board/system design. The default value
6351 you will find in any recent u-boot distribution in
6352 walnut.h should work for you. I'd set it to a value larger
6353 than your SDRAM module. If you have a 64MB SDRAM module, set
6354 it above 400_0000. Just make sure your board has no resources
6355 that are supposed to respond to that address! That code in
6356 start.S has been around a while and should work as is when
6357 you get the config right.
6362 It is essential to remember this, since it has some impact on the C
6363 code for the initialization procedures:
6365 * Initialized global data (data segment) is read-only. Do not attempt
6368 * Do not use any uninitialized global data (or implicitly initialized
6369 as zero data - BSS segment) at all - this is undefined, initiali-
6370 zation is performed later (when relocating to RAM).
6372 * Stack space is very limited. Avoid big data buffers or things like
6375 Having only the stack as writable memory limits means we cannot use
6376 normal global data to share information between the code. But it
6377 turned out that the implementation of U-Boot can be greatly
6378 simplified by making a global data structure (gd_t) available to all
6379 functions. We could pass a pointer to this data as argument to _all_
6380 functions, but this would bloat the code. Instead we use a feature of
6381 the GCC compiler (Global Register Variables) to share the data: we
6382 place a pointer (gd) to the global data into a register which we
6383 reserve for this purpose.
6385 When choosing a register for such a purpose we are restricted by the
6386 relevant (E)ABI specifications for the current architecture, and by
6387 GCC's implementation.
6389 For PowerPC, the following registers have specific use:
6391 R2: reserved for system use
6392 R3-R4: parameter passing and return values
6393 R5-R10: parameter passing
6394 R13: small data area pointer
6398 (U-Boot also uses R12 as internal GOT pointer. r12
6399 is a volatile register so r12 needs to be reset when
6400 going back and forth between asm and C)
6402 ==> U-Boot will use R2 to hold a pointer to the global data
6404 Note: on PPC, we could use a static initializer (since the
6405 address of the global data structure is known at compile time),
6406 but it turned out that reserving a register results in somewhat
6407 smaller code - although the code savings are not that big (on
6408 average for all boards 752 bytes for the whole U-Boot image,
6409 624 text + 127 data).
6411 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6412 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6414 ==> U-Boot will use P3 to hold a pointer to the global data
6416 On ARM, the following registers are used:
6418 R0: function argument word/integer result
6419 R1-R3: function argument word
6420 R9: platform specific
6421 R10: stack limit (used only if stack checking is enabled)
6422 R11: argument (frame) pointer
6423 R12: temporary workspace
6426 R15: program counter
6428 ==> U-Boot will use R9 to hold a pointer to the global data
6430 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6432 On Nios II, the ABI is documented here:
6433 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6435 ==> U-Boot will use gp to hold a pointer to the global data
6437 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6438 to access small data sections, so gp is free.
6440 On NDS32, the following registers are used:
6442 R0-R1: argument/return
6444 R15: temporary register for assembler
6445 R16: trampoline register
6446 R28: frame pointer (FP)
6447 R29: global pointer (GP)
6448 R30: link register (LP)
6449 R31: stack pointer (SP)
6450 PC: program counter (PC)
6452 ==> U-Boot will use R10 to hold a pointer to the global data
6454 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6455 or current versions of GCC may "optimize" the code too much.
6460 U-Boot runs in system state and uses physical addresses, i.e. the
6461 MMU is not used either for address mapping nor for memory protection.
6463 The available memory is mapped to fixed addresses using the memory
6464 controller. In this process, a contiguous block is formed for each
6465 memory type (Flash, SDRAM, SRAM), even when it consists of several
6466 physical memory banks.
6468 U-Boot is installed in the first 128 kB of the first Flash bank (on
6469 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6470 booting and sizing and initializing DRAM, the code relocates itself
6471 to the upper end of DRAM. Immediately below the U-Boot code some
6472 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6473 configuration setting]. Below that, a structure with global Board
6474 Info data is placed, followed by the stack (growing downward).
6476 Additionally, some exception handler code is copied to the low 8 kB
6477 of DRAM (0x00000000 ... 0x00001FFF).
6479 So a typical memory configuration with 16 MB of DRAM could look like
6482 0x0000 0000 Exception Vector code
6485 0x0000 2000 Free for Application Use
6491 0x00FB FF20 Monitor Stack (Growing downward)
6492 0x00FB FFAC Board Info Data and permanent copy of global data
6493 0x00FC 0000 Malloc Arena
6496 0x00FE 0000 RAM Copy of Monitor Code
6497 ... eventually: LCD or video framebuffer
6498 ... eventually: pRAM (Protected RAM - unchanged by reset)
6499 0x00FF FFFF [End of RAM]
6502 System Initialization:
6503 ----------------------
6505 In the reset configuration, U-Boot starts at the reset entry point
6506 (on most PowerPC systems at address 0x00000100). Because of the reset
6507 configuration for CS0# this is a mirror of the on board Flash memory.
6508 To be able to re-map memory U-Boot then jumps to its link address.
6509 To be able to implement the initialization code in C, a (small!)
6510 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6511 which provide such a feature like MPC8xx or MPC8260), or in a locked
6512 part of the data cache. After that, U-Boot initializes the CPU core,
6513 the caches and the SIU.
6515 Next, all (potentially) available memory banks are mapped using a
6516 preliminary mapping. For example, we put them on 512 MB boundaries
6517 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6518 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6519 programmed for SDRAM access. Using the temporary configuration, a
6520 simple memory test is run that determines the size of the SDRAM
6523 When there is more than one SDRAM bank, and the banks are of
6524 different size, the largest is mapped first. For equal size, the first
6525 bank (CS2#) is mapped first. The first mapping is always for address
6526 0x00000000, with any additional banks following immediately to create
6527 contiguous memory starting from 0.
6529 Then, the monitor installs itself at the upper end of the SDRAM area
6530 and allocates memory for use by malloc() and for the global Board
6531 Info data; also, the exception vector code is copied to the low RAM
6532 pages, and the final stack is set up.
6534 Only after this relocation will you have a "normal" C environment;
6535 until that you are restricted in several ways, mostly because you are
6536 running from ROM, and because the code will have to be relocated to a
6540 U-Boot Porting Guide:
6541 ----------------------
6543 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6547 int main(int argc, char *argv[])
6549 sighandler_t no_more_time;
6551 signal(SIGALRM, no_more_time);
6552 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6554 if (available_money > available_manpower) {
6555 Pay consultant to port U-Boot;
6559 Download latest U-Boot source;
6561 Subscribe to u-boot mailing list;
6564 email("Hi, I am new to U-Boot, how do I get started?");
6567 Read the README file in the top level directory;
6568 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6569 Read applicable doc/*.README;
6570 Read the source, Luke;
6571 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6574 if (available_money > toLocalCurrency ($2500))
6577 Add a lot of aggravation and time;
6579 if (a similar board exists) { /* hopefully... */
6580 cp -a board/<similar> board/<myboard>
6581 cp include/configs/<similar>.h include/configs/<myboard>.h
6583 Create your own board support subdirectory;
6584 Create your own board include/configs/<myboard>.h file;
6586 Edit new board/<myboard> files
6587 Edit new include/configs/<myboard>.h
6592 Add / modify source code;
6596 email("Hi, I am having problems...");
6598 Send patch file to the U-Boot email list;
6599 if (reasonable critiques)
6600 Incorporate improvements from email list code review;
6602 Defend code as written;
6608 void no_more_time (int sig)
6617 All contributions to U-Boot should conform to the Linux kernel
6618 coding style; see the file "Documentation/CodingStyle" and the script
6619 "scripts/Lindent" in your Linux kernel source directory.
6621 Source files originating from a different project (for example the
6622 MTD subsystem) are generally exempt from these guidelines and are not
6623 reformatted to ease subsequent migration to newer versions of those
6626 Please note that U-Boot is implemented in C (and to some small parts in
6627 Assembler); no C++ is used, so please do not use C++ style comments (//)
6630 Please also stick to the following formatting rules:
6631 - remove any trailing white space
6632 - use TAB characters for indentation and vertical alignment, not spaces
6633 - make sure NOT to use DOS '\r\n' line feeds
6634 - do not add more than 2 consecutive empty lines to source files
6635 - do not add trailing empty lines to source files
6637 Submissions which do not conform to the standards may be returned
6638 with a request to reformat the changes.
6644 Since the number of patches for U-Boot is growing, we need to
6645 establish some rules. Submissions which do not conform to these rules
6646 may be rejected, even when they contain important and valuable stuff.
6648 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6650 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6651 see http://lists.denx.de/mailman/listinfo/u-boot
6653 When you send a patch, please include the following information with
6656 * For bug fixes: a description of the bug and how your patch fixes
6657 this bug. Please try to include a way of demonstrating that the
6658 patch actually fixes something.
6660 * For new features: a description of the feature and your
6663 * A CHANGELOG entry as plaintext (separate from the patch)
6665 * For major contributions, your entry to the CREDITS file
6667 * When you add support for a new board, don't forget to add a
6668 maintainer e-mail address to the boards.cfg file, too.
6670 * If your patch adds new configuration options, don't forget to
6671 document these in the README file.
6673 * The patch itself. If you are using git (which is *strongly*
6674 recommended) you can easily generate the patch using the
6675 "git format-patch". If you then use "git send-email" to send it to
6676 the U-Boot mailing list, you will avoid most of the common problems
6677 with some other mail clients.
6679 If you cannot use git, use "diff -purN OLD NEW". If your version of
6680 diff does not support these options, then get the latest version of
6683 The current directory when running this command shall be the parent
6684 directory of the U-Boot source tree (i. e. please make sure that
6685 your patch includes sufficient directory information for the
6688 We prefer patches as plain text. MIME attachments are discouraged,
6689 and compressed attachments must not be used.
6691 * If one logical set of modifications affects or creates several
6692 files, all these changes shall be submitted in a SINGLE patch file.
6694 * Changesets that contain different, unrelated modifications shall be
6695 submitted as SEPARATE patches, one patch per changeset.
6700 * Before sending the patch, run the MAKEALL script on your patched
6701 source tree and make sure that no errors or warnings are reported
6702 for any of the boards.
6704 * Keep your modifications to the necessary minimum: A patch
6705 containing several unrelated changes or arbitrary reformats will be
6706 returned with a request to re-formatting / split it.
6708 * If you modify existing code, make sure that your new code does not
6709 add to the memory footprint of the code ;-) Small is beautiful!
6710 When adding new features, these should compile conditionally only
6711 (using #ifdef), and the resulting code with the new feature
6712 disabled must not need more memory than the old code without your
6715 * Remember that there is a size limit of 100 kB per message on the
6716 u-boot mailing list. Bigger patches will be moderated. If they are
6717 reasonable and not too big, they will be acknowledged. But patches
6718 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob