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.
1261 CONFIG_VERSION_VARIABLE
1262 If this variable is defined, an environment variable
1263 named "ver" is created by U-Boot showing the U-Boot
1264 version as printed by the "version" command.
1265 Any change to this variable will be reverted at the
1270 When CONFIG_CMD_DATE is selected, the type of the RTC
1271 has to be selected, too. Define exactly one of the
1274 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1275 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1276 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1277 CONFIG_RTC_MC146818 - use MC146818 RTC
1278 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1279 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1280 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1281 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1282 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1283 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1284 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1285 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1286 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1289 Note that if the RTC uses I2C, then the I2C interface
1290 must also be configured. See I2C Support, below.
1293 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1295 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1296 chip-ngpio pairs that tell the PCA953X driver the number of
1297 pins supported by a particular chip.
1299 Note that if the GPIO device uses I2C, then the I2C interface
1300 must also be configured. See I2C Support, below.
1303 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1304 accesses and can checksum them or write a list of them out
1305 to memory. See the 'iotrace' command for details. This is
1306 useful for testing device drivers since it can confirm that
1307 the driver behaves the same way before and after a code
1308 change. Currently this is supported on sandbox and arm. To
1309 add support for your architecture, add '#include <iotrace.h>'
1310 to the bottom of arch/<arch>/include/asm/io.h and test.
1312 Example output from the 'iotrace stats' command is below.
1313 Note that if the trace buffer is exhausted, the checksum will
1314 still continue to operate.
1317 Start: 10000000 (buffer start address)
1318 Size: 00010000 (buffer size)
1319 Offset: 00000120 (current buffer offset)
1320 Output: 10000120 (start + offset)
1321 Count: 00000018 (number of trace records)
1322 CRC32: 9526fb66 (CRC32 of all trace records)
1324 - Timestamp Support:
1326 When CONFIG_TIMESTAMP is selected, the timestamp
1327 (date and time) of an image is printed by image
1328 commands like bootm or iminfo. This option is
1329 automatically enabled when you select CONFIG_CMD_DATE .
1331 - Partition Labels (disklabels) Supported:
1332 Zero or more of the following:
1333 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1334 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1335 Intel architecture, USB sticks, etc.
1336 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1337 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1338 bootloader. Note 2TB partition limit; see
1340 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1342 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1343 CONFIG_CMD_SCSI) you must configure support for at
1344 least one non-MTD partition type as well.
1347 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1348 board configurations files but used nowhere!
1350 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1351 be performed by calling the function
1352 ide_set_reset(int reset)
1353 which has to be defined in a board specific file
1358 Set this to enable ATAPI support.
1363 Set this to enable support for disks larger than 137GB
1364 Also look at CONFIG_SYS_64BIT_LBA.
1365 Whithout these , LBA48 support uses 32bit variables and will 'only'
1366 support disks up to 2.1TB.
1368 CONFIG_SYS_64BIT_LBA:
1369 When enabled, makes the IDE subsystem use 64bit sector addresses.
1373 At the moment only there is only support for the
1374 SYM53C8XX SCSI controller; define
1375 CONFIG_SCSI_SYM53C8XX to enable it.
1377 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1378 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1379 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1380 maximum numbers of LUNs, SCSI ID's and target
1382 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1384 The environment variable 'scsidevs' is set to the number of
1385 SCSI devices found during the last scan.
1387 - NETWORK Support (PCI):
1389 Support for Intel 8254x/8257x gigabit chips.
1392 Utility code for direct access to the SPI bus on Intel 8257x.
1393 This does not do anything useful unless you set at least one
1394 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1396 CONFIG_E1000_SPI_GENERIC
1397 Allow generic access to the SPI bus on the Intel 8257x, for
1398 example with the "sspi" command.
1401 Management command for E1000 devices. When used on devices
1402 with SPI support you can reprogram the EEPROM from U-Boot.
1404 CONFIG_E1000_FALLBACK_MAC
1405 default MAC for empty EEPROM after production.
1408 Support for Intel 82557/82559/82559ER chips.
1409 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1410 write routine for first time initialisation.
1413 Support for Digital 2114x chips.
1414 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1415 modem chip initialisation (KS8761/QS6611).
1418 Support for National dp83815 chips.
1421 Support for National dp8382[01] gigabit chips.
1423 - NETWORK Support (other):
1425 CONFIG_DRIVER_AT91EMAC
1426 Support for AT91RM9200 EMAC.
1429 Define this to use reduced MII inteface
1431 CONFIG_DRIVER_AT91EMAC_QUIET
1432 If this defined, the driver is quiet.
1433 The driver doen't show link status messages.
1435 CONFIG_CALXEDA_XGMAC
1436 Support for the Calxeda XGMAC device
1439 Support for SMSC's LAN91C96 chips.
1441 CONFIG_LAN91C96_BASE
1442 Define this to hold the physical address
1443 of the LAN91C96's I/O space
1445 CONFIG_LAN91C96_USE_32_BIT
1446 Define this to enable 32 bit addressing
1449 Support for SMSC's LAN91C111 chip
1451 CONFIG_SMC91111_BASE
1452 Define this to hold the physical address
1453 of the device (I/O space)
1455 CONFIG_SMC_USE_32_BIT
1456 Define this if data bus is 32 bits
1458 CONFIG_SMC_USE_IOFUNCS
1459 Define this to use i/o functions instead of macros
1460 (some hardware wont work with macros)
1462 CONFIG_DRIVER_TI_EMAC
1463 Support for davinci emac
1465 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1466 Define this if you have more then 3 PHYs.
1469 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1471 CONFIG_FTGMAC100_EGIGA
1472 Define this to use GE link update with gigabit PHY.
1473 Define this if FTGMAC100 is connected to gigabit PHY.
1474 If your system has 10/100 PHY only, it might not occur
1475 wrong behavior. Because PHY usually return timeout or
1476 useless data when polling gigabit status and gigabit
1477 control registers. This behavior won't affect the
1478 correctnessof 10/100 link speed update.
1481 Support for SMSC's LAN911x and LAN921x chips
1484 Define this to hold the physical address
1485 of the device (I/O space)
1487 CONFIG_SMC911X_32_BIT
1488 Define this if data bus is 32 bits
1490 CONFIG_SMC911X_16_BIT
1491 Define this if data bus is 16 bits. If your processor
1492 automatically converts one 32 bit word to two 16 bit
1493 words you may also try CONFIG_SMC911X_32_BIT.
1496 Support for Renesas on-chip Ethernet controller
1498 CONFIG_SH_ETHER_USE_PORT
1499 Define the number of ports to be used
1501 CONFIG_SH_ETHER_PHY_ADDR
1502 Define the ETH PHY's address
1504 CONFIG_SH_ETHER_CACHE_WRITEBACK
1505 If this option is set, the driver enables cache flush.
1509 Support for PWM modul on the imx6.
1513 Support TPM devices.
1516 Support for i2c bus TPM devices. Only one device
1517 per system is supported at this time.
1519 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1520 Define the the i2c bus number for the TPM device
1522 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1523 Define the TPM's address on the i2c bus
1525 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1526 Define the burst count bytes upper limit
1528 CONFIG_TPM_ATMEL_TWI
1529 Support for Atmel TWI TPM device. Requires I2C support.
1532 Support for generic parallel port TPM devices. Only one device
1533 per system is supported at this time.
1535 CONFIG_TPM_TIS_BASE_ADDRESS
1536 Base address where the generic TPM device is mapped
1537 to. Contemporary x86 systems usually map it at
1541 Add tpm monitor functions.
1542 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1543 provides monitor access to authorized functions.
1546 Define this to enable the TPM support library which provides
1547 functional interfaces to some TPM commands.
1548 Requires support for a TPM device.
1550 CONFIG_TPM_AUTH_SESSIONS
1551 Define this to enable authorized functions in the TPM library.
1552 Requires CONFIG_TPM and CONFIG_SHA1.
1555 At the moment only the UHCI host controller is
1556 supported (PIP405, MIP405, MPC5200); define
1557 CONFIG_USB_UHCI to enable it.
1558 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1559 and define CONFIG_USB_STORAGE to enable the USB
1562 Supported are USB Keyboards and USB Floppy drives
1564 MPC5200 USB requires additional defines:
1566 for 528 MHz Clock: 0x0001bbbb
1570 for differential drivers: 0x00001000
1571 for single ended drivers: 0x00005000
1572 for differential drivers on PSC3: 0x00000100
1573 for single ended drivers on PSC3: 0x00004100
1574 CONFIG_SYS_USB_EVENT_POLL
1575 May be defined to allow interrupt polling
1576 instead of using asynchronous interrupts
1578 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1579 txfilltuning field in the EHCI controller on reset.
1581 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1582 HW module registers.
1585 Define the below if you wish to use the USB console.
1586 Once firmware is rebuilt from a serial console issue the
1587 command "setenv stdin usbtty; setenv stdout usbtty" and
1588 attach your USB cable. The Unix command "dmesg" should print
1589 it has found a new device. The environment variable usbtty
1590 can be set to gserial or cdc_acm to enable your device to
1591 appear to a USB host as a Linux gserial device or a
1592 Common Device Class Abstract Control Model serial device.
1593 If you select usbtty = gserial you should be able to enumerate
1595 # modprobe usbserial vendor=0xVendorID product=0xProductID
1596 else if using cdc_acm, simply setting the environment
1597 variable usbtty to be cdc_acm should suffice. The following
1598 might be defined in YourBoardName.h
1601 Define this to build a UDC device
1604 Define this to have a tty type of device available to
1605 talk to the UDC device
1608 Define this to enable the high speed support for usb
1609 device and usbtty. If this feature is enabled, a routine
1610 int is_usbd_high_speed(void)
1611 also needs to be defined by the driver to dynamically poll
1612 whether the enumeration has succeded at high speed or full
1615 CONFIG_SYS_CONSOLE_IS_IN_ENV
1616 Define this if you want stdin, stdout &/or stderr to
1620 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1621 Derive USB clock from external clock "blah"
1622 - CONFIG_SYS_USB_EXTC_CLK 0x02
1624 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1625 Derive USB clock from brgclk
1626 - CONFIG_SYS_USB_BRG_CLK 0x04
1628 If you have a USB-IF assigned VendorID then you may wish to
1629 define your own vendor specific values either in BoardName.h
1630 or directly in usbd_vendor_info.h. If you don't define
1631 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1632 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1633 should pretend to be a Linux device to it's target host.
1635 CONFIG_USBD_MANUFACTURER
1636 Define this string as the name of your company for
1637 - CONFIG_USBD_MANUFACTURER "my company"
1639 CONFIG_USBD_PRODUCT_NAME
1640 Define this string as the name of your product
1641 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1643 CONFIG_USBD_VENDORID
1644 Define this as your assigned Vendor ID from the USB
1645 Implementors Forum. This *must* be a genuine Vendor ID
1646 to avoid polluting the USB namespace.
1647 - CONFIG_USBD_VENDORID 0xFFFF
1649 CONFIG_USBD_PRODUCTID
1650 Define this as the unique Product ID
1652 - CONFIG_USBD_PRODUCTID 0xFFFF
1654 - ULPI Layer Support:
1655 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1656 the generic ULPI layer. The generic layer accesses the ULPI PHY
1657 via the platform viewport, so you need both the genric layer and
1658 the viewport enabled. Currently only Chipidea/ARC based
1659 viewport is supported.
1660 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1661 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1662 If your ULPI phy needs a different reference clock than the
1663 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1664 the appropriate value in Hz.
1667 The MMC controller on the Intel PXA is supported. To
1668 enable this define CONFIG_MMC. The MMC can be
1669 accessed from the boot prompt by mapping the device
1670 to physical memory similar to flash. Command line is
1671 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1672 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1675 Support for Renesas on-chip MMCIF controller
1677 CONFIG_SH_MMCIF_ADDR
1678 Define the base address of MMCIF registers
1681 Define the clock frequency for MMCIF
1684 Enable the generic MMC driver
1686 CONFIG_SUPPORT_EMMC_BOOT
1687 Enable some additional features of the eMMC boot partitions.
1689 CONFIG_SUPPORT_EMMC_RPMB
1690 Enable the commands for reading, writing and programming the
1691 key for the Replay Protection Memory Block partition in eMMC.
1693 - USB Device Firmware Update (DFU) class support:
1695 This enables the USB portion of the DFU USB class
1698 This enables the command "dfu" which is used to have
1699 U-Boot create a DFU class device via USB. This command
1700 requires that the "dfu_alt_info" environment variable be
1701 set and define the alt settings to expose to the host.
1704 This enables support for exposing (e)MMC devices via DFU.
1707 This enables support for exposing NAND devices via DFU.
1710 This enables support for exposing RAM via DFU.
1711 Note: DFU spec refer to non-volatile memory usage, but
1712 allow usages beyond the scope of spec - here RAM usage,
1713 one that would help mostly the developer.
1715 CONFIG_SYS_DFU_DATA_BUF_SIZE
1716 Dfu transfer uses a buffer before writing data to the
1717 raw storage device. Make the size (in bytes) of this buffer
1718 configurable. The size of this buffer is also configurable
1719 through the "dfu_bufsiz" environment variable.
1721 CONFIG_SYS_DFU_MAX_FILE_SIZE
1722 When updating files rather than the raw storage device,
1723 we use a static buffer to copy the file into and then write
1724 the buffer once we've been given the whole file. Define
1725 this to the maximum filesize (in bytes) for the buffer.
1726 Default is 4 MiB if undefined.
1728 DFU_DEFAULT_POLL_TIMEOUT
1729 Poll timeout [ms], is the timeout a device can send to the
1730 host. The host must wait for this timeout before sending
1731 a subsequent DFU_GET_STATUS request to the device.
1733 DFU_MANIFEST_POLL_TIMEOUT
1734 Poll timeout [ms], which the device sends to the host when
1735 entering dfuMANIFEST state. Host waits this timeout, before
1736 sending again an USB request to the device.
1738 - USB Device Android Fastboot support:
1740 This enables the command "fastboot" which enables the Android
1741 fastboot mode for the platform's USB device. Fastboot is a USB
1742 protocol for downloading images, flashing and device control
1743 used on Android devices.
1744 See doc/README.android-fastboot for more information.
1746 CONFIG_ANDROID_BOOT_IMAGE
1747 This enables support for booting images which use the Android
1748 image format header.
1750 CONFIG_USB_FASTBOOT_BUF_ADDR
1751 The fastboot protocol requires a large memory buffer for
1752 downloads. Define this to the starting RAM address to use for
1755 CONFIG_USB_FASTBOOT_BUF_SIZE
1756 The fastboot protocol requires a large memory buffer for
1757 downloads. This buffer should be as large as possible for a
1758 platform. Define this to the size available RAM for fastboot.
1760 CONFIG_FASTBOOT_FLASH
1761 The fastboot protocol includes a "flash" command for writing
1762 the downloaded image to a non-volatile storage device. Define
1763 this to enable the "fastboot flash" command.
1765 CONFIG_FASTBOOT_FLASH_MMC_DEV
1766 The fastboot "flash" command requires additional information
1767 regarding the non-volatile storage device. Define this to
1768 the eMMC device that fastboot should use to store the image.
1770 CONFIG_FASTBOOT_GPT_NAME
1771 The fastboot "flash" command supports writing the downloaded
1772 image to the Protective MBR and the Primary GUID Partition
1773 Table. (Additionally, this downloaded image is post-processed
1774 to generate and write the Backup GUID Partition Table.)
1775 This occurs when the specified "partition name" on the
1776 "fastboot flash" command line matches this value.
1777 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1779 - Journaling Flash filesystem support:
1780 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1781 CONFIG_JFFS2_NAND_DEV
1782 Define these for a default partition on a NAND device
1784 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1785 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1786 Define these for a default partition on a NOR device
1788 CONFIG_SYS_JFFS_CUSTOM_PART
1789 Define this to create an own partition. You have to provide a
1790 function struct part_info* jffs2_part_info(int part_num)
1792 If you define only one JFFS2 partition you may also want to
1793 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1794 to disable the command chpart. This is the default when you
1795 have not defined a custom partition
1797 - FAT(File Allocation Table) filesystem write function support:
1800 Define this to enable support for saving memory data as a
1801 file in FAT formatted partition.
1803 This will also enable the command "fatwrite" enabling the
1804 user to write files to FAT.
1806 CBFS (Coreboot Filesystem) support
1809 Define this to enable support for reading from a Coreboot
1810 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1813 - FAT(File Allocation Table) filesystem cluster size:
1814 CONFIG_FS_FAT_MAX_CLUSTSIZE
1816 Define the max cluster size for fat operations else
1817 a default value of 65536 will be defined.
1822 Define this to enable standard (PC-Style) keyboard
1826 Standard PC keyboard driver with US (is default) and
1827 GERMAN key layout (switch via environment 'keymap=de') support.
1828 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1829 for cfb_console. Supports cursor blinking.
1832 Enables a Chrome OS keyboard using the CROS_EC interface.
1833 This uses CROS_EC to communicate with a second microcontroller
1834 which provides key scans on request.
1839 Define this to enable video support (for output to
1842 CONFIG_VIDEO_CT69000
1844 Enable Chips & Technologies 69000 Video chip
1846 CONFIG_VIDEO_SMI_LYNXEM
1847 Enable Silicon Motion SMI 712/710/810 Video chip. The
1848 video output is selected via environment 'videoout'
1849 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1852 For the CT69000 and SMI_LYNXEM drivers, videomode is
1853 selected via environment 'videomode'. Two different ways
1855 - "videomode=num" 'num' is a standard LiLo mode numbers.
1856 Following standard modes are supported (* is default):
1858 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1859 -------------+---------------------------------------------
1860 8 bits | 0x301* 0x303 0x305 0x161 0x307
1861 15 bits | 0x310 0x313 0x316 0x162 0x319
1862 16 bits | 0x311 0x314 0x317 0x163 0x31A
1863 24 bits | 0x312 0x315 0x318 ? 0x31B
1864 -------------+---------------------------------------------
1865 (i.e. setenv videomode 317; saveenv; reset;)
1867 - "videomode=bootargs" all the video parameters are parsed
1868 from the bootargs. (See drivers/video/videomodes.c)
1871 CONFIG_VIDEO_SED13806
1872 Enable Epson SED13806 driver. This driver supports 8bpp
1873 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1874 or CONFIG_VIDEO_SED13806_16BPP
1877 Enable the Freescale DIU video driver. Reference boards for
1878 SOCs that have a DIU should define this macro to enable DIU
1879 support, and should also define these other macros:
1885 CONFIG_VIDEO_SW_CURSOR
1886 CONFIG_VGA_AS_SINGLE_DEVICE
1888 CONFIG_VIDEO_BMP_LOGO
1890 The DIU driver will look for the 'video-mode' environment
1891 variable, and if defined, enable the DIU as a console during
1892 boot. See the documentation file README.video for a
1893 description of this variable.
1897 Enable the VGA video / BIOS for x86. The alternative if you
1898 are using coreboot is to use the coreboot frame buffer
1905 Define this to enable a custom keyboard support.
1906 This simply calls drv_keyboard_init() which must be
1907 defined in your board-specific files.
1908 The only board using this so far is RBC823.
1910 - LCD Support: CONFIG_LCD
1912 Define this to enable LCD support (for output to LCD
1913 display); also select one of the supported displays
1914 by defining one of these:
1918 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1920 CONFIG_NEC_NL6448AC33:
1922 NEC NL6448AC33-18. Active, color, single scan.
1924 CONFIG_NEC_NL6448BC20
1926 NEC NL6448BC20-08. 6.5", 640x480.
1927 Active, color, single scan.
1929 CONFIG_NEC_NL6448BC33_54
1931 NEC NL6448BC33-54. 10.4", 640x480.
1932 Active, color, single scan.
1936 Sharp 320x240. Active, color, single scan.
1937 It isn't 16x9, and I am not sure what it is.
1939 CONFIG_SHARP_LQ64D341
1941 Sharp LQ64D341 display, 640x480.
1942 Active, color, single scan.
1946 HLD1045 display, 640x480.
1947 Active, color, single scan.
1951 Optrex CBL50840-2 NF-FW 99 22 M5
1953 Hitachi LMG6912RPFC-00T
1957 320x240. Black & white.
1959 Normally display is black on white background; define
1960 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1962 CONFIG_LCD_ALIGNMENT
1964 Normally the LCD is page-aligned (typically 4KB). If this is
1965 defined then the LCD will be aligned to this value instead.
1966 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1967 here, since it is cheaper to change data cache settings on
1968 a per-section basis.
1970 CONFIG_CONSOLE_SCROLL_LINES
1972 When the console need to be scrolled, this is the number of
1973 lines to scroll by. It defaults to 1. Increasing this makes
1974 the console jump but can help speed up operation when scrolling
1979 Support drawing of RLE8-compressed bitmaps on the LCD.
1983 Enables an 'i2c edid' command which can read EDID
1984 information over I2C from an attached LCD display.
1986 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1988 If this option is set, the environment is checked for
1989 a variable "splashimage". If found, the usual display
1990 of logo, copyright and system information on the LCD
1991 is suppressed and the BMP image at the address
1992 specified in "splashimage" is loaded instead. The
1993 console is redirected to the "nulldev", too. This
1994 allows for a "silent" boot where a splash screen is
1995 loaded very quickly after power-on.
1997 CONFIG_SPLASHIMAGE_GUARD
1999 If this option is set, then U-Boot will prevent the environment
2000 variable "splashimage" from being set to a problematic address
2001 (see README.displaying-bmps).
2002 This option is useful for targets where, due to alignment
2003 restrictions, an improperly aligned BMP image will cause a data
2004 abort. If you think you will not have problems with unaligned
2005 accesses (for example because your toolchain prevents them)
2006 there is no need to set this option.
2008 CONFIG_SPLASH_SCREEN_ALIGN
2010 If this option is set the splash image can be freely positioned
2011 on the screen. Environment variable "splashpos" specifies the
2012 position as "x,y". If a positive number is given it is used as
2013 number of pixel from left/top. If a negative number is given it
2014 is used as number of pixel from right/bottom. You can also
2015 specify 'm' for centering the image.
2018 setenv splashpos m,m
2019 => image at center of screen
2021 setenv splashpos 30,20
2022 => image at x = 30 and y = 20
2024 setenv splashpos -10,m
2025 => vertically centered image
2026 at x = dspWidth - bmpWidth - 9
2028 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2030 If this option is set, additionally to standard BMP
2031 images, gzipped BMP images can be displayed via the
2032 splashscreen support or the bmp command.
2034 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2036 If this option is set, 8-bit RLE compressed BMP images
2037 can be displayed via the splashscreen support or the
2040 - Do compressing for memory range:
2043 If this option is set, it would use zlib deflate method
2044 to compress the specified memory at its best effort.
2046 - Compression support:
2049 Enabled by default to support gzip compressed images.
2053 If this option is set, support for bzip2 compressed
2054 images is included. If not, only uncompressed and gzip
2055 compressed images are supported.
2057 NOTE: the bzip2 algorithm requires a lot of RAM, so
2058 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2063 If this option is set, support for lzma compressed
2066 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2067 requires an amount of dynamic memory that is given by the
2070 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2072 Where lc and lp stand for, respectively, Literal context bits
2073 and Literal pos bits.
2075 This value is upper-bounded by 14MB in the worst case. Anyway,
2076 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2077 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2078 a very small buffer.
2080 Use the lzmainfo tool to determinate the lc and lp values and
2081 then calculate the amount of needed dynamic memory (ensuring
2082 the appropriate CONFIG_SYS_MALLOC_LEN value).
2086 If this option is set, support for LZO compressed images
2092 The address of PHY on MII bus.
2094 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2096 The clock frequency of the MII bus
2100 If this option is set, support for speed/duplex
2101 detection of gigabit PHY is included.
2103 CONFIG_PHY_RESET_DELAY
2105 Some PHY like Intel LXT971A need extra delay after
2106 reset before any MII register access is possible.
2107 For such PHY, set this option to the usec delay
2108 required. (minimum 300usec for LXT971A)
2110 CONFIG_PHY_CMD_DELAY (ppc4xx)
2112 Some PHY like Intel LXT971A need extra delay after
2113 command issued before MII status register can be read
2123 Define a default value for Ethernet address to use
2124 for the respective Ethernet interface, in case this
2125 is not determined automatically.
2130 Define a default value for the IP address to use for
2131 the default Ethernet interface, in case this is not
2132 determined through e.g. bootp.
2133 (Environment variable "ipaddr")
2135 - Server IP address:
2138 Defines a default value for the IP address of a TFTP
2139 server to contact when using the "tftboot" command.
2140 (Environment variable "serverip")
2142 CONFIG_KEEP_SERVERADDR
2144 Keeps the server's MAC address, in the env 'serveraddr'
2145 for passing to bootargs (like Linux's netconsole option)
2147 - Gateway IP address:
2150 Defines a default value for the IP address of the
2151 default router where packets to other networks are
2153 (Environment variable "gatewayip")
2158 Defines a default value for the subnet mask (or
2159 routing prefix) which is used to determine if an IP
2160 address belongs to the local subnet or needs to be
2161 forwarded through a router.
2162 (Environment variable "netmask")
2164 - Multicast TFTP Mode:
2167 Defines whether you want to support multicast TFTP as per
2168 rfc-2090; for example to work with atftp. Lets lots of targets
2169 tftp down the same boot image concurrently. Note: the Ethernet
2170 driver in use must provide a function: mcast() to join/leave a
2173 - BOOTP Recovery Mode:
2174 CONFIG_BOOTP_RANDOM_DELAY
2176 If you have many targets in a network that try to
2177 boot using BOOTP, you may want to avoid that all
2178 systems send out BOOTP requests at precisely the same
2179 moment (which would happen for instance at recovery
2180 from a power failure, when all systems will try to
2181 boot, thus flooding the BOOTP server. Defining
2182 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2183 inserted before sending out BOOTP requests. The
2184 following delays are inserted then:
2186 1st BOOTP request: delay 0 ... 1 sec
2187 2nd BOOTP request: delay 0 ... 2 sec
2188 3rd BOOTP request: delay 0 ... 4 sec
2190 BOOTP requests: delay 0 ... 8 sec
2192 CONFIG_BOOTP_ID_CACHE_SIZE
2194 BOOTP packets are uniquely identified using a 32-bit ID. The
2195 server will copy the ID from client requests to responses and
2196 U-Boot will use this to determine if it is the destination of
2197 an incoming response. Some servers will check that addresses
2198 aren't in use before handing them out (usually using an ARP
2199 ping) and therefore take up to a few hundred milliseconds to
2200 respond. Network congestion may also influence the time it
2201 takes for a response to make it back to the client. If that
2202 time is too long, U-Boot will retransmit requests. In order
2203 to allow earlier responses to still be accepted after these
2204 retransmissions, U-Boot's BOOTP client keeps a small cache of
2205 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2206 cache. The default is to keep IDs for up to four outstanding
2207 requests. Increasing this will allow U-Boot to accept offers
2208 from a BOOTP client in networks with unusually high latency.
2210 - DHCP Advanced Options:
2211 You can fine tune the DHCP functionality by defining
2212 CONFIG_BOOTP_* symbols:
2214 CONFIG_BOOTP_SUBNETMASK
2215 CONFIG_BOOTP_GATEWAY
2216 CONFIG_BOOTP_HOSTNAME
2217 CONFIG_BOOTP_NISDOMAIN
2218 CONFIG_BOOTP_BOOTPATH
2219 CONFIG_BOOTP_BOOTFILESIZE
2222 CONFIG_BOOTP_SEND_HOSTNAME
2223 CONFIG_BOOTP_NTPSERVER
2224 CONFIG_BOOTP_TIMEOFFSET
2225 CONFIG_BOOTP_VENDOREX
2226 CONFIG_BOOTP_MAY_FAIL
2228 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2229 environment variable, not the BOOTP server.
2231 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2232 after the configured retry count, the call will fail
2233 instead of starting over. This can be used to fail over
2234 to Link-local IP address configuration if the DHCP server
2237 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2238 serverip from a DHCP server, it is possible that more
2239 than one DNS serverip is offered to the client.
2240 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2241 serverip will be stored in the additional environment
2242 variable "dnsip2". The first DNS serverip is always
2243 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2246 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2247 to do a dynamic update of a DNS server. To do this, they
2248 need the hostname of the DHCP requester.
2249 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2250 of the "hostname" environment variable is passed as
2251 option 12 to the DHCP server.
2253 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2255 A 32bit value in microseconds for a delay between
2256 receiving a "DHCP Offer" and sending the "DHCP Request".
2257 This fixes a problem with certain DHCP servers that don't
2258 respond 100% of the time to a "DHCP request". E.g. On an
2259 AT91RM9200 processor running at 180MHz, this delay needed
2260 to be *at least* 15,000 usec before a Windows Server 2003
2261 DHCP server would reply 100% of the time. I recommend at
2262 least 50,000 usec to be safe. The alternative is to hope
2263 that one of the retries will be successful but note that
2264 the DHCP timeout and retry process takes a longer than
2267 - Link-local IP address negotiation:
2268 Negotiate with other link-local clients on the local network
2269 for an address that doesn't require explicit configuration.
2270 This is especially useful if a DHCP server cannot be guaranteed
2271 to exist in all environments that the device must operate.
2273 See doc/README.link-local for more information.
2276 CONFIG_CDP_DEVICE_ID
2278 The device id used in CDP trigger frames.
2280 CONFIG_CDP_DEVICE_ID_PREFIX
2282 A two character string which is prefixed to the MAC address
2287 A printf format string which contains the ascii name of
2288 the port. Normally is set to "eth%d" which sets
2289 eth0 for the first Ethernet, eth1 for the second etc.
2291 CONFIG_CDP_CAPABILITIES
2293 A 32bit integer which indicates the device capabilities;
2294 0x00000010 for a normal host which does not forwards.
2298 An ascii string containing the version of the software.
2302 An ascii string containing the name of the platform.
2306 A 32bit integer sent on the trigger.
2308 CONFIG_CDP_POWER_CONSUMPTION
2310 A 16bit integer containing the power consumption of the
2311 device in .1 of milliwatts.
2313 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2315 A byte containing the id of the VLAN.
2317 - Status LED: CONFIG_STATUS_LED
2319 Several configurations allow to display the current
2320 status using a LED. For instance, the LED will blink
2321 fast while running U-Boot code, stop blinking as
2322 soon as a reply to a BOOTP request was received, and
2323 start blinking slow once the Linux kernel is running
2324 (supported by a status LED driver in the Linux
2325 kernel). Defining CONFIG_STATUS_LED enables this
2331 The status LED can be connected to a GPIO pin.
2332 In such cases, the gpio_led driver can be used as a
2333 status LED backend implementation. Define CONFIG_GPIO_LED
2334 to include the gpio_led driver in the U-Boot binary.
2336 CONFIG_GPIO_LED_INVERTED_TABLE
2337 Some GPIO connected LEDs may have inverted polarity in which
2338 case the GPIO high value corresponds to LED off state and
2339 GPIO low value corresponds to LED on state.
2340 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2341 with a list of GPIO LEDs that have inverted polarity.
2343 - CAN Support: CONFIG_CAN_DRIVER
2345 Defining CONFIG_CAN_DRIVER enables CAN driver support
2346 on those systems that support this (optional)
2347 feature, like the TQM8xxL modules.
2349 - I2C Support: CONFIG_SYS_I2C
2351 This enable the NEW i2c subsystem, and will allow you to use
2352 i2c commands at the u-boot command line (as long as you set
2353 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2354 based realtime clock chips or other i2c devices. See
2355 common/cmd_i2c.c for a description of the command line
2358 ported i2c driver to the new framework:
2359 - drivers/i2c/soft_i2c.c:
2360 - activate first bus with CONFIG_SYS_I2C_SOFT define
2361 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2362 for defining speed and slave address
2363 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2364 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2365 for defining speed and slave address
2366 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2367 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2368 for defining speed and slave address
2369 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2370 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2371 for defining speed and slave address
2373 - drivers/i2c/fsl_i2c.c:
2374 - activate i2c driver with CONFIG_SYS_I2C_FSL
2375 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2376 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2377 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2379 - If your board supports a second fsl i2c bus, define
2380 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2381 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2382 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2385 - drivers/i2c/tegra_i2c.c:
2386 - activate this driver with CONFIG_SYS_I2C_TEGRA
2387 - This driver adds 4 i2c buses with a fix speed from
2388 100000 and the slave addr 0!
2390 - drivers/i2c/ppc4xx_i2c.c
2391 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2392 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2393 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2395 - drivers/i2c/i2c_mxc.c
2396 - activate this driver with CONFIG_SYS_I2C_MXC
2397 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2398 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2399 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2400 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2401 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2402 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2403 If those defines are not set, default value is 100000
2404 for speed, and 0 for slave.
2406 - drivers/i2c/rcar_i2c.c:
2407 - activate this driver with CONFIG_SYS_I2C_RCAR
2408 - This driver adds 4 i2c buses
2410 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2411 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2412 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2413 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2414 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2415 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2416 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2417 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2418 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2420 - drivers/i2c/sh_i2c.c:
2421 - activate this driver with CONFIG_SYS_I2C_SH
2422 - This driver adds from 2 to 5 i2c buses
2424 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2425 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2426 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2427 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2428 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2429 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2430 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2431 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2432 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2433 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2434 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2435 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2436 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2438 - drivers/i2c/omap24xx_i2c.c
2439 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2440 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2441 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2442 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2443 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2444 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2445 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2446 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2447 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2448 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2449 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2451 - drivers/i2c/zynq_i2c.c
2452 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2453 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2454 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2456 - drivers/i2c/s3c24x0_i2c.c:
2457 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2458 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2459 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2460 with a fix speed from 100000 and the slave addr 0!
2462 - drivers/i2c/ihs_i2c.c
2463 - activate this driver with CONFIG_SYS_I2C_IHS
2464 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2465 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2466 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2467 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2468 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2469 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2470 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2471 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2472 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2473 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2474 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2475 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2479 CONFIG_SYS_NUM_I2C_BUSES
2480 Hold the number of i2c buses you want to use. If you
2481 don't use/have i2c muxes on your i2c bus, this
2482 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2485 CONFIG_SYS_I2C_DIRECT_BUS
2486 define this, if you don't use i2c muxes on your hardware.
2487 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2490 CONFIG_SYS_I2C_MAX_HOPS
2491 define how many muxes are maximal consecutively connected
2492 on one i2c bus. If you not use i2c muxes, omit this
2495 CONFIG_SYS_I2C_BUSES
2496 hold a list of buses you want to use, only used if
2497 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2498 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2499 CONFIG_SYS_NUM_I2C_BUSES = 9:
2501 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2502 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2503 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2504 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2505 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2506 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2507 {1, {I2C_NULL_HOP}}, \
2508 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2509 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2513 bus 0 on adapter 0 without a mux
2514 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2515 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2516 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2517 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2518 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2519 bus 6 on adapter 1 without a mux
2520 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2521 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2523 If you do not have i2c muxes on your board, omit this define.
2525 - Legacy I2C Support: CONFIG_HARD_I2C
2527 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2528 provides the following compelling advantages:
2530 - more than one i2c adapter is usable
2531 - approved multibus support
2532 - better i2c mux support
2534 ** Please consider updating your I2C driver now. **
2536 These enable legacy I2C serial bus commands. Defining
2537 CONFIG_HARD_I2C will include the appropriate I2C driver
2538 for the selected CPU.
2540 This will allow you to use i2c commands at the u-boot
2541 command line (as long as you set CONFIG_CMD_I2C in
2542 CONFIG_COMMANDS) and communicate with i2c based realtime
2543 clock chips. See common/cmd_i2c.c for a description of the
2544 command line interface.
2546 CONFIG_HARD_I2C selects a hardware I2C controller.
2548 There are several other quantities that must also be
2549 defined when you define CONFIG_HARD_I2C.
2551 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2552 to be the frequency (in Hz) at which you wish your i2c bus
2553 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2554 the CPU's i2c node address).
2556 Now, the u-boot i2c code for the mpc8xx
2557 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2558 and so its address should therefore be cleared to 0 (See,
2559 eg, MPC823e User's Manual p.16-473). So, set
2560 CONFIG_SYS_I2C_SLAVE to 0.
2562 CONFIG_SYS_I2C_INIT_MPC5XXX
2564 When a board is reset during an i2c bus transfer
2565 chips might think that the current transfer is still
2566 in progress. Reset the slave devices by sending start
2567 commands until the slave device responds.
2569 That's all that's required for CONFIG_HARD_I2C.
2571 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2572 then the following macros need to be defined (examples are
2573 from include/configs/lwmon.h):
2577 (Optional). Any commands necessary to enable the I2C
2578 controller or configure ports.
2580 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2584 (Only for MPC8260 CPU). The I/O port to use (the code
2585 assumes both bits are on the same port). Valid values
2586 are 0..3 for ports A..D.
2590 The code necessary to make the I2C data line active
2591 (driven). If the data line is open collector, this
2594 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2598 The code necessary to make the I2C data line tri-stated
2599 (inactive). If the data line is open collector, this
2602 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2606 Code that returns true if the I2C data line is high,
2609 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2613 If <bit> is true, sets the I2C data line high. If it
2614 is false, it clears it (low).
2616 eg: #define I2C_SDA(bit) \
2617 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2618 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2622 If <bit> is true, sets the I2C clock line high. If it
2623 is false, it clears it (low).
2625 eg: #define I2C_SCL(bit) \
2626 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2627 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2631 This delay is invoked four times per clock cycle so this
2632 controls the rate of data transfer. The data rate thus
2633 is 1 / (I2C_DELAY * 4). Often defined to be something
2636 #define I2C_DELAY udelay(2)
2638 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2640 If your arch supports the generic GPIO framework (asm/gpio.h),
2641 then you may alternatively define the two GPIOs that are to be
2642 used as SCL / SDA. Any of the previous I2C_xxx macros will
2643 have GPIO-based defaults assigned to them as appropriate.
2645 You should define these to the GPIO value as given directly to
2646 the generic GPIO functions.
2648 CONFIG_SYS_I2C_INIT_BOARD
2650 When a board is reset during an i2c bus transfer
2651 chips might think that the current transfer is still
2652 in progress. On some boards it is possible to access
2653 the i2c SCLK line directly, either by using the
2654 processor pin as a GPIO or by having a second pin
2655 connected to the bus. If this option is defined a
2656 custom i2c_init_board() routine in boards/xxx/board.c
2657 is run early in the boot sequence.
2659 CONFIG_SYS_I2C_BOARD_LATE_INIT
2661 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2662 defined a custom i2c_board_late_init() routine in
2663 boards/xxx/board.c is run AFTER the operations in i2c_init()
2664 is completed. This callpoint can be used to unreset i2c bus
2665 using CPU i2c controller register accesses for CPUs whose i2c
2666 controller provide such a method. It is called at the end of
2667 i2c_init() to allow i2c_init operations to setup the i2c bus
2668 controller on the CPU (e.g. setting bus speed & slave address).
2670 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2672 This option enables configuration of bi_iic_fast[] flags
2673 in u-boot bd_info structure based on u-boot environment
2674 variable "i2cfast". (see also i2cfast)
2676 CONFIG_I2C_MULTI_BUS
2678 This option allows the use of multiple I2C buses, each of which
2679 must have a controller. At any point in time, only one bus is
2680 active. To switch to a different bus, use the 'i2c dev' command.
2681 Note that bus numbering is zero-based.
2683 CONFIG_SYS_I2C_NOPROBES
2685 This option specifies a list of I2C devices that will be skipped
2686 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2687 is set, specify a list of bus-device pairs. Otherwise, specify
2688 a 1D array of device addresses
2691 #undef CONFIG_I2C_MULTI_BUS
2692 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2694 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2696 #define CONFIG_I2C_MULTI_BUS
2697 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2699 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2701 CONFIG_SYS_SPD_BUS_NUM
2703 If defined, then this indicates the I2C bus number for DDR SPD.
2704 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2706 CONFIG_SYS_RTC_BUS_NUM
2708 If defined, then this indicates the I2C bus number for the RTC.
2709 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2711 CONFIG_SYS_DTT_BUS_NUM
2713 If defined, then this indicates the I2C bus number for the DTT.
2714 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2716 CONFIG_SYS_I2C_DTT_ADDR:
2718 If defined, specifies the I2C address of the DTT device.
2719 If not defined, then U-Boot uses predefined value for
2720 specified DTT device.
2722 CONFIG_SOFT_I2C_READ_REPEATED_START
2724 defining this will force the i2c_read() function in
2725 the soft_i2c driver to perform an I2C repeated start
2726 between writing the address pointer and reading the
2727 data. If this define is omitted the default behaviour
2728 of doing a stop-start sequence will be used. Most I2C
2729 devices can use either method, but some require one or
2732 - SPI Support: CONFIG_SPI
2734 Enables SPI driver (so far only tested with
2735 SPI EEPROM, also an instance works with Crystal A/D and
2736 D/As on the SACSng board)
2740 Enables the driver for SPI controller on SuperH. Currently
2741 only SH7757 is supported.
2745 Enables extended (16-bit) SPI EEPROM addressing.
2746 (symmetrical to CONFIG_I2C_X)
2750 Enables a software (bit-bang) SPI driver rather than
2751 using hardware support. This is a general purpose
2752 driver that only requires three general I/O port pins
2753 (two outputs, one input) to function. If this is
2754 defined, the board configuration must define several
2755 SPI configuration items (port pins to use, etc). For
2756 an example, see include/configs/sacsng.h.
2760 Enables a hardware SPI driver for general-purpose reads
2761 and writes. As with CONFIG_SOFT_SPI, the board configuration
2762 must define a list of chip-select function pointers.
2763 Currently supported on some MPC8xxx processors. For an
2764 example, see include/configs/mpc8349emds.h.
2768 Enables the driver for the SPI controllers on i.MX and MXC
2769 SoCs. Currently i.MX31/35/51 are supported.
2771 CONFIG_SYS_SPI_MXC_WAIT
2772 Timeout for waiting until spi transfer completed.
2773 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2775 - FPGA Support: CONFIG_FPGA
2777 Enables FPGA subsystem.
2779 CONFIG_FPGA_<vendor>
2781 Enables support for specific chip vendors.
2784 CONFIG_FPGA_<family>
2786 Enables support for FPGA family.
2787 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2791 Specify the number of FPGA devices to support.
2793 CONFIG_CMD_FPGA_LOADMK
2795 Enable support for fpga loadmk command
2797 CONFIG_CMD_FPGA_LOADP
2799 Enable support for fpga loadp command - load partial bitstream
2801 CONFIG_CMD_FPGA_LOADBP
2803 Enable support for fpga loadbp command - load partial bitstream
2806 CONFIG_SYS_FPGA_PROG_FEEDBACK
2808 Enable printing of hash marks during FPGA configuration.
2810 CONFIG_SYS_FPGA_CHECK_BUSY
2812 Enable checks on FPGA configuration interface busy
2813 status by the configuration function. This option
2814 will require a board or device specific function to
2819 If defined, a function that provides delays in the FPGA
2820 configuration driver.
2822 CONFIG_SYS_FPGA_CHECK_CTRLC
2823 Allow Control-C to interrupt FPGA configuration
2825 CONFIG_SYS_FPGA_CHECK_ERROR
2827 Check for configuration errors during FPGA bitfile
2828 loading. For example, abort during Virtex II
2829 configuration if the INIT_B line goes low (which
2830 indicated a CRC error).
2832 CONFIG_SYS_FPGA_WAIT_INIT
2834 Maximum time to wait for the INIT_B line to de-assert
2835 after PROB_B has been de-asserted during a Virtex II
2836 FPGA configuration sequence. The default time is 500
2839 CONFIG_SYS_FPGA_WAIT_BUSY
2841 Maximum time to wait for BUSY to de-assert during
2842 Virtex II FPGA configuration. The default is 5 ms.
2844 CONFIG_SYS_FPGA_WAIT_CONFIG
2846 Time to wait after FPGA configuration. The default is
2849 - Configuration Management:
2852 Some SoCs need special image types (e.g. U-Boot binary
2853 with a special header) as build targets. By defining
2854 CONFIG_BUILD_TARGET in the SoC / board header, this
2855 special image will be automatically built upon calling
2860 If defined, this string will be added to the U-Boot
2861 version information (U_BOOT_VERSION)
2863 - Vendor Parameter Protection:
2865 U-Boot considers the values of the environment
2866 variables "serial#" (Board Serial Number) and
2867 "ethaddr" (Ethernet Address) to be parameters that
2868 are set once by the board vendor / manufacturer, and
2869 protects these variables from casual modification by
2870 the user. Once set, these variables are read-only,
2871 and write or delete attempts are rejected. You can
2872 change this behaviour:
2874 If CONFIG_ENV_OVERWRITE is #defined in your config
2875 file, the write protection for vendor parameters is
2876 completely disabled. Anybody can change or delete
2879 Alternatively, if you #define _both_ CONFIG_ETHADDR
2880 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2881 Ethernet address is installed in the environment,
2882 which can be changed exactly ONCE by the user. [The
2883 serial# is unaffected by this, i. e. it remains
2886 The same can be accomplished in a more flexible way
2887 for any variable by configuring the type of access
2888 to allow for those variables in the ".flags" variable
2889 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2894 Define this variable to enable the reservation of
2895 "protected RAM", i. e. RAM which is not overwritten
2896 by U-Boot. Define CONFIG_PRAM to hold the number of
2897 kB you want to reserve for pRAM. You can overwrite
2898 this default value by defining an environment
2899 variable "pram" to the number of kB you want to
2900 reserve. Note that the board info structure will
2901 still show the full amount of RAM. If pRAM is
2902 reserved, a new environment variable "mem" will
2903 automatically be defined to hold the amount of
2904 remaining RAM in a form that can be passed as boot
2905 argument to Linux, for instance like that:
2907 setenv bootargs ... mem=\${mem}
2910 This way you can tell Linux not to use this memory,
2911 either, which results in a memory region that will
2912 not be affected by reboots.
2914 *WARNING* If your board configuration uses automatic
2915 detection of the RAM size, you must make sure that
2916 this memory test is non-destructive. So far, the
2917 following board configurations are known to be
2920 IVMS8, IVML24, SPD8xx, TQM8xxL,
2921 HERMES, IP860, RPXlite, LWMON,
2924 - Access to physical memory region (> 4GB)
2925 Some basic support is provided for operations on memory not
2926 normally accessible to U-Boot - e.g. some architectures
2927 support access to more than 4GB of memory on 32-bit
2928 machines using physical address extension or similar.
2929 Define CONFIG_PHYSMEM to access this basic support, which
2930 currently only supports clearing the memory.
2935 Define this variable to stop the system in case of a
2936 fatal error, so that you have to reset it manually.
2937 This is probably NOT a good idea for an embedded
2938 system where you want the system to reboot
2939 automatically as fast as possible, but it may be
2940 useful during development since you can try to debug
2941 the conditions that lead to the situation.
2943 CONFIG_NET_RETRY_COUNT
2945 This variable defines the number of retries for
2946 network operations like ARP, RARP, TFTP, or BOOTP
2947 before giving up the operation. If not defined, a
2948 default value of 5 is used.
2952 Timeout waiting for an ARP reply in milliseconds.
2956 Timeout in milliseconds used in NFS protocol.
2957 If you encounter "ERROR: Cannot umount" in nfs command,
2958 try longer timeout such as
2959 #define CONFIG_NFS_TIMEOUT 10000UL
2961 - Command Interpreter:
2962 CONFIG_AUTO_COMPLETE
2964 Enable auto completion of commands using TAB.
2966 CONFIG_SYS_PROMPT_HUSH_PS2
2968 This defines the secondary prompt string, which is
2969 printed when the command interpreter needs more input
2970 to complete a command. Usually "> ".
2974 In the current implementation, the local variables
2975 space and global environment variables space are
2976 separated. Local variables are those you define by
2977 simply typing `name=value'. To access a local
2978 variable later on, you have write `$name' or
2979 `${name}'; to execute the contents of a variable
2980 directly type `$name' at the command prompt.
2982 Global environment variables are those you use
2983 setenv/printenv to work with. To run a command stored
2984 in such a variable, you need to use the run command,
2985 and you must not use the '$' sign to access them.
2987 To store commands and special characters in a
2988 variable, please use double quotation marks
2989 surrounding the whole text of the variable, instead
2990 of the backslashes before semicolons and special
2993 - Command Line Editing and History:
2994 CONFIG_CMDLINE_EDITING
2996 Enable editing and History functions for interactive
2997 command line input operations
2999 - Default Environment:
3000 CONFIG_EXTRA_ENV_SETTINGS
3002 Define this to contain any number of null terminated
3003 strings (variable = value pairs) that will be part of
3004 the default environment compiled into the boot image.
3006 For example, place something like this in your
3007 board's config file:
3009 #define CONFIG_EXTRA_ENV_SETTINGS \
3013 Warning: This method is based on knowledge about the
3014 internal format how the environment is stored by the
3015 U-Boot code. This is NOT an official, exported
3016 interface! Although it is unlikely that this format
3017 will change soon, there is no guarantee either.
3018 You better know what you are doing here.
3020 Note: overly (ab)use of the default environment is
3021 discouraged. Make sure to check other ways to preset
3022 the environment like the "source" command or the
3025 CONFIG_ENV_VARS_UBOOT_CONFIG
3027 Define this in order to add variables describing the
3028 U-Boot build configuration to the default environment.
3029 These will be named arch, cpu, board, vendor, and soc.
3031 Enabling this option will cause the following to be defined:
3039 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3041 Define this in order to add variables describing certain
3042 run-time determined information about the hardware to the
3043 environment. These will be named board_name, board_rev.
3045 CONFIG_DELAY_ENVIRONMENT
3047 Normally the environment is loaded when the board is
3048 initialised so that it is available to U-Boot. This inhibits
3049 that so that the environment is not available until
3050 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3051 this is instead controlled by the value of
3052 /config/load-environment.
3054 - DataFlash Support:
3055 CONFIG_HAS_DATAFLASH
3057 Defining this option enables DataFlash features and
3058 allows to read/write in Dataflash via the standard
3061 - Serial Flash support
3064 Defining this option enables SPI flash commands
3065 'sf probe/read/write/erase/update'.
3067 Usage requires an initial 'probe' to define the serial
3068 flash parameters, followed by read/write/erase/update
3071 The following defaults may be provided by the platform
3072 to handle the common case when only a single serial
3073 flash is present on the system.
3075 CONFIG_SF_DEFAULT_BUS Bus identifier
3076 CONFIG_SF_DEFAULT_CS Chip-select
3077 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3078 CONFIG_SF_DEFAULT_SPEED in Hz
3082 Define this option to include a destructive SPI flash
3085 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3087 Define this option to use the Bank addr/Extended addr
3088 support on SPI flashes which has size > 16Mbytes.
3090 CONFIG_SF_DUAL_FLASH Dual flash memories
3092 Define this option to use dual flash support where two flash
3093 memories can be connected with a given cs line.
3094 Currently Xilinx Zynq qspi supports these type of connections.
3096 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3097 enable the W#/Vpp signal to disable writing to the status
3098 register on ST MICRON flashes like the N25Q128.
3099 The status register write enable/disable bit, combined with
3100 the W#/VPP signal provides hardware data protection for the
3101 device as follows: When the enable/disable bit is set to 1,
3102 and the W#/VPP signal is driven LOW, the status register
3103 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3104 operation will not execute. The only way to exit this
3105 hardware-protected mode is to drive W#/VPP HIGH.
3107 - SystemACE Support:
3110 Adding this option adds support for Xilinx SystemACE
3111 chips attached via some sort of local bus. The address
3112 of the chip must also be defined in the
3113 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3115 #define CONFIG_SYSTEMACE
3116 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3118 When SystemACE support is added, the "ace" device type
3119 becomes available to the fat commands, i.e. fatls.
3121 - TFTP Fixed UDP Port:
3124 If this is defined, the environment variable tftpsrcp
3125 is used to supply the TFTP UDP source port value.
3126 If tftpsrcp isn't defined, the normal pseudo-random port
3127 number generator is used.
3129 Also, the environment variable tftpdstp is used to supply
3130 the TFTP UDP destination port value. If tftpdstp isn't
3131 defined, the normal port 69 is used.
3133 The purpose for tftpsrcp is to allow a TFTP server to
3134 blindly start the TFTP transfer using the pre-configured
3135 target IP address and UDP port. This has the effect of
3136 "punching through" the (Windows XP) firewall, allowing
3137 the remainder of the TFTP transfer to proceed normally.
3138 A better solution is to properly configure the firewall,
3139 but sometimes that is not allowed.
3144 This enables a generic 'hash' command which can produce
3145 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3149 Enable the hash verify command (hash -v). This adds to code
3152 CONFIG_SHA1 - support SHA1 hashing
3153 CONFIG_SHA256 - support SHA256 hashing
3155 Note: There is also a sha1sum command, which should perhaps
3156 be deprecated in favour of 'hash sha1'.
3158 - Freescale i.MX specific commands:
3159 CONFIG_CMD_HDMIDETECT
3160 This enables 'hdmidet' command which returns true if an
3161 HDMI monitor is detected. This command is i.MX 6 specific.
3164 This enables the 'bmode' (bootmode) command for forcing
3165 a boot from specific media.
3167 This is useful for forcing the ROM's usb downloader to
3168 activate upon a watchdog reset which is nice when iterating
3169 on U-Boot. Using the reset button or running bmode normal
3170 will set it back to normal. This command currently
3171 supports i.MX53 and i.MX6.
3176 This enables the RSA algorithm used for FIT image verification
3177 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3179 The Modular Exponentiation algorithm in RSA is implemented using
3180 driver model. So CONFIG_DM needs to be enabled by default for this
3181 library to function.
3183 The signing part is build into mkimage regardless of this
3184 option. The software based modular exponentiation is built into
3185 mkimage irrespective of this option.
3187 - bootcount support:
3188 CONFIG_BOOTCOUNT_LIMIT
3190 This enables the bootcounter support, see:
3191 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3194 enable special bootcounter support on at91sam9xe based boards.
3196 enable special bootcounter support on blackfin based boards.
3198 enable special bootcounter support on da850 based boards.
3199 CONFIG_BOOTCOUNT_RAM
3200 enable support for the bootcounter in RAM
3201 CONFIG_BOOTCOUNT_I2C
3202 enable support for the bootcounter on an i2c (like RTC) device.
3203 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3204 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3206 CONFIG_BOOTCOUNT_ALEN = address len
3208 - Show boot progress:
3209 CONFIG_SHOW_BOOT_PROGRESS
3211 Defining this option allows to add some board-
3212 specific code (calling a user-provided function
3213 "show_boot_progress(int)") that enables you to show
3214 the system's boot progress on some display (for
3215 example, some LED's) on your board. At the moment,
3216 the following checkpoints are implemented:
3218 - Detailed boot stage timing
3220 Define this option to get detailed timing of each stage
3221 of the boot process.
3223 CONFIG_BOOTSTAGE_USER_COUNT
3224 This is the number of available user bootstage records.
3225 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3226 a new ID will be allocated from this stash. If you exceed
3227 the limit, recording will stop.
3229 CONFIG_BOOTSTAGE_REPORT
3230 Define this to print a report before boot, similar to this:
3232 Timer summary in microseconds:
3235 3,575,678 3,575,678 board_init_f start
3236 3,575,695 17 arch_cpu_init A9
3237 3,575,777 82 arch_cpu_init done
3238 3,659,598 83,821 board_init_r start
3239 3,910,375 250,777 main_loop
3240 29,916,167 26,005,792 bootm_start
3241 30,361,327 445,160 start_kernel
3243 CONFIG_CMD_BOOTSTAGE
3244 Add a 'bootstage' command which supports printing a report
3245 and un/stashing of bootstage data.
3247 CONFIG_BOOTSTAGE_FDT
3248 Stash the bootstage information in the FDT. A root 'bootstage'
3249 node is created with each bootstage id as a child. Each child
3250 has a 'name' property and either 'mark' containing the
3251 mark time in microsecond, or 'accum' containing the
3252 accumulated time for that bootstage id in microseconds.
3257 name = "board_init_f";
3266 Code in the Linux kernel can find this in /proc/devicetree.
3268 Legacy uImage format:
3271 1 common/cmd_bootm.c before attempting to boot an image
3272 -1 common/cmd_bootm.c Image header has bad magic number
3273 2 common/cmd_bootm.c Image header has correct magic number
3274 -2 common/cmd_bootm.c Image header has bad checksum
3275 3 common/cmd_bootm.c Image header has correct checksum
3276 -3 common/cmd_bootm.c Image data has bad checksum
3277 4 common/cmd_bootm.c Image data has correct checksum
3278 -4 common/cmd_bootm.c Image is for unsupported architecture
3279 5 common/cmd_bootm.c Architecture check OK
3280 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3281 6 common/cmd_bootm.c Image Type check OK
3282 -6 common/cmd_bootm.c gunzip uncompression error
3283 -7 common/cmd_bootm.c Unimplemented compression type
3284 7 common/cmd_bootm.c Uncompression OK
3285 8 common/cmd_bootm.c No uncompress/copy overwrite error
3286 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3288 9 common/image.c Start initial ramdisk verification
3289 -10 common/image.c Ramdisk header has bad magic number
3290 -11 common/image.c Ramdisk header has bad checksum
3291 10 common/image.c Ramdisk header is OK
3292 -12 common/image.c Ramdisk data has bad checksum
3293 11 common/image.c Ramdisk data has correct checksum
3294 12 common/image.c Ramdisk verification complete, start loading
3295 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3296 13 common/image.c Start multifile image verification
3297 14 common/image.c No initial ramdisk, no multifile, continue.
3299 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3301 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3302 -31 post/post.c POST test failed, detected by post_output_backlog()
3303 -32 post/post.c POST test failed, detected by post_run_single()
3305 34 common/cmd_doc.c before loading a Image from a DOC device
3306 -35 common/cmd_doc.c Bad usage of "doc" command
3307 35 common/cmd_doc.c correct usage of "doc" command
3308 -36 common/cmd_doc.c No boot device
3309 36 common/cmd_doc.c correct boot device
3310 -37 common/cmd_doc.c Unknown Chip ID on boot device
3311 37 common/cmd_doc.c correct chip ID found, device available
3312 -38 common/cmd_doc.c Read Error on boot device
3313 38 common/cmd_doc.c reading Image header from DOC device OK
3314 -39 common/cmd_doc.c Image header has bad magic number
3315 39 common/cmd_doc.c Image header has correct magic number
3316 -40 common/cmd_doc.c Error reading Image from DOC device
3317 40 common/cmd_doc.c Image header has correct magic number
3318 41 common/cmd_ide.c before loading a Image from a IDE device
3319 -42 common/cmd_ide.c Bad usage of "ide" command
3320 42 common/cmd_ide.c correct usage of "ide" command
3321 -43 common/cmd_ide.c No boot device
3322 43 common/cmd_ide.c boot device found
3323 -44 common/cmd_ide.c Device not available
3324 44 common/cmd_ide.c Device available
3325 -45 common/cmd_ide.c wrong partition selected
3326 45 common/cmd_ide.c partition selected
3327 -46 common/cmd_ide.c Unknown partition table
3328 46 common/cmd_ide.c valid partition table found
3329 -47 common/cmd_ide.c Invalid partition type
3330 47 common/cmd_ide.c correct partition type
3331 -48 common/cmd_ide.c Error reading Image Header on boot device
3332 48 common/cmd_ide.c reading Image Header from IDE device OK
3333 -49 common/cmd_ide.c Image header has bad magic number
3334 49 common/cmd_ide.c Image header has correct magic number
3335 -50 common/cmd_ide.c Image header has bad checksum
3336 50 common/cmd_ide.c Image header has correct checksum
3337 -51 common/cmd_ide.c Error reading Image from IDE device
3338 51 common/cmd_ide.c reading Image from IDE device OK
3339 52 common/cmd_nand.c before loading a Image from a NAND device
3340 -53 common/cmd_nand.c Bad usage of "nand" command
3341 53 common/cmd_nand.c correct usage of "nand" command
3342 -54 common/cmd_nand.c No boot device
3343 54 common/cmd_nand.c boot device found
3344 -55 common/cmd_nand.c Unknown Chip ID on boot device
3345 55 common/cmd_nand.c correct chip ID found, device available
3346 -56 common/cmd_nand.c Error reading Image Header on boot device
3347 56 common/cmd_nand.c reading Image Header from NAND device OK
3348 -57 common/cmd_nand.c Image header has bad magic number
3349 57 common/cmd_nand.c Image header has correct magic number
3350 -58 common/cmd_nand.c Error reading Image from NAND device
3351 58 common/cmd_nand.c reading Image from NAND device OK
3353 -60 common/env_common.c Environment has a bad CRC, using default
3355 64 net/eth.c starting with Ethernet configuration.
3356 -64 net/eth.c no Ethernet found.
3357 65 net/eth.c Ethernet found.
3359 -80 common/cmd_net.c usage wrong
3360 80 common/cmd_net.c before calling NetLoop()
3361 -81 common/cmd_net.c some error in NetLoop() occurred
3362 81 common/cmd_net.c NetLoop() back without error
3363 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3364 82 common/cmd_net.c trying automatic boot
3365 83 common/cmd_net.c running "source" command
3366 -83 common/cmd_net.c some error in automatic boot or "source" command
3367 84 common/cmd_net.c end without errors
3372 100 common/cmd_bootm.c Kernel FIT Image has correct format
3373 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3374 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3375 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3376 102 common/cmd_bootm.c Kernel unit name specified
3377 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3378 103 common/cmd_bootm.c Found configuration node
3379 104 common/cmd_bootm.c Got kernel subimage node offset
3380 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3381 105 common/cmd_bootm.c Kernel subimage hash verification OK
3382 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3383 106 common/cmd_bootm.c Architecture check OK
3384 -106 common/cmd_bootm.c Kernel subimage has wrong type
3385 107 common/cmd_bootm.c Kernel subimage type OK
3386 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3387 108 common/cmd_bootm.c Got kernel subimage data/size
3388 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3389 -109 common/cmd_bootm.c Can't get kernel subimage type
3390 -110 common/cmd_bootm.c Can't get kernel subimage comp
3391 -111 common/cmd_bootm.c Can't get kernel subimage os
3392 -112 common/cmd_bootm.c Can't get kernel subimage load address
3393 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3395 120 common/image.c Start initial ramdisk verification
3396 -120 common/image.c Ramdisk FIT image has incorrect format
3397 121 common/image.c Ramdisk FIT image has correct format
3398 122 common/image.c No ramdisk subimage unit name, using configuration
3399 -122 common/image.c Can't get configuration for ramdisk subimage
3400 123 common/image.c Ramdisk unit name specified
3401 -124 common/image.c Can't get ramdisk subimage node offset
3402 125 common/image.c Got ramdisk subimage node offset
3403 -125 common/image.c Ramdisk subimage hash verification failed
3404 126 common/image.c Ramdisk subimage hash verification OK
3405 -126 common/image.c Ramdisk subimage for unsupported architecture
3406 127 common/image.c Architecture check OK
3407 -127 common/image.c Can't get ramdisk subimage data/size
3408 128 common/image.c Got ramdisk subimage data/size
3409 129 common/image.c Can't get ramdisk load address
3410 -129 common/image.c Got ramdisk load address
3412 -130 common/cmd_doc.c Incorrect FIT image format
3413 131 common/cmd_doc.c FIT image format OK
3415 -140 common/cmd_ide.c Incorrect FIT image format
3416 141 common/cmd_ide.c FIT image format OK
3418 -150 common/cmd_nand.c Incorrect FIT image format
3419 151 common/cmd_nand.c FIT image format OK
3421 - legacy image format:
3422 CONFIG_IMAGE_FORMAT_LEGACY
3423 enables the legacy image format support in U-Boot.
3426 enabled if CONFIG_FIT_SIGNATURE is not defined.
3428 CONFIG_DISABLE_IMAGE_LEGACY
3429 disable the legacy image format
3431 This define is introduced, as the legacy image format is
3432 enabled per default for backward compatibility.
3434 - FIT image support:
3436 Enable support for the FIT uImage format.
3438 CONFIG_FIT_BEST_MATCH
3439 When no configuration is explicitly selected, default to the
3440 one whose fdt's compatibility field best matches that of
3441 U-Boot itself. A match is considered "best" if it matches the
3442 most specific compatibility entry of U-Boot's fdt's root node.
3443 The order of entries in the configuration's fdt is ignored.
3445 CONFIG_FIT_SIGNATURE
3446 This option enables signature verification of FIT uImages,
3447 using a hash signed and verified using RSA. See
3448 doc/uImage.FIT/signature.txt for more details.
3450 WARNING: When relying on signed FIT images with required
3451 signature check the legacy image format is default
3452 disabled. If a board need legacy image format support
3453 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3455 CONFIG_FIT_DISABLE_SHA256
3456 Supporting SHA256 hashes has quite an impact on binary size.
3457 For constrained systems sha256 hash support can be disabled
3460 - Standalone program support:
3461 CONFIG_STANDALONE_LOAD_ADDR
3463 This option defines a board specific value for the
3464 address where standalone program gets loaded, thus
3465 overwriting the architecture dependent default
3468 - Frame Buffer Address:
3471 Define CONFIG_FB_ADDR if you want to use specific
3472 address for frame buffer. This is typically the case
3473 when using a graphics controller has separate video
3474 memory. U-Boot will then place the frame buffer at
3475 the given address instead of dynamically reserving it
3476 in system RAM by calling lcd_setmem(), which grabs
3477 the memory for the frame buffer depending on the
3478 configured panel size.
3480 Please see board_init_f function.
3482 - Automatic software updates via TFTP server
3484 CONFIG_UPDATE_TFTP_CNT_MAX
3485 CONFIG_UPDATE_TFTP_MSEC_MAX
3487 These options enable and control the auto-update feature;
3488 for a more detailed description refer to doc/README.update.
3490 - MTD Support (mtdparts command, UBI support)
3493 Adds the MTD device infrastructure from the Linux kernel.
3494 Needed for mtdparts command support.
3496 CONFIG_MTD_PARTITIONS
3498 Adds the MTD partitioning infrastructure from the Linux
3499 kernel. Needed for UBI support.
3501 CONFIG_MTD_NAND_VERIFY_WRITE
3502 verify if the written data is correct reread.
3507 Adds commands for interacting with MTD partitions formatted
3508 with the UBI flash translation layer
3510 Requires also defining CONFIG_RBTREE
3512 CONFIG_UBI_SILENCE_MSG
3514 Make the verbose messages from UBI stop printing. This leaves
3515 warnings and errors enabled.
3518 CONFIG_MTD_UBI_WL_THRESHOLD
3519 This parameter defines the maximum difference between the highest
3520 erase counter value and the lowest erase counter value of eraseblocks
3521 of UBI devices. When this threshold is exceeded, UBI starts performing
3522 wear leveling by means of moving data from eraseblock with low erase
3523 counter to eraseblocks with high erase counter.
3525 The default value should be OK for SLC NAND flashes, NOR flashes and
3526 other flashes which have eraseblock life-cycle 100000 or more.
3527 However, in case of MLC NAND flashes which typically have eraseblock
3528 life-cycle less than 10000, the threshold should be lessened (e.g.,
3529 to 128 or 256, although it does not have to be power of 2).
3533 CONFIG_MTD_UBI_BEB_LIMIT
3534 This option specifies the maximum bad physical eraseblocks UBI
3535 expects on the MTD device (per 1024 eraseblocks). If the
3536 underlying flash does not admit of bad eraseblocks (e.g. NOR
3537 flash), this value is ignored.
3539 NAND datasheets often specify the minimum and maximum NVM
3540 (Number of Valid Blocks) for the flashes' endurance lifetime.
3541 The maximum expected bad eraseblocks per 1024 eraseblocks
3542 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3543 which gives 20 for most NANDs (MaxNVB is basically the total
3544 count of eraseblocks on the chip).
3546 To put it differently, if this value is 20, UBI will try to
3547 reserve about 1.9% of physical eraseblocks for bad blocks
3548 handling. And that will be 1.9% of eraseblocks on the entire
3549 NAND chip, not just the MTD partition UBI attaches. This means
3550 that if you have, say, a NAND flash chip admits maximum 40 bad
3551 eraseblocks, and it is split on two MTD partitions of the same
3552 size, UBI will reserve 40 eraseblocks when attaching a
3557 CONFIG_MTD_UBI_FASTMAP
3558 Fastmap is a mechanism which allows attaching an UBI device
3559 in nearly constant time. Instead of scanning the whole MTD device it
3560 only has to locate a checkpoint (called fastmap) on the device.
3561 The on-flash fastmap contains all information needed to attach
3562 the device. Using fastmap makes only sense on large devices where
3563 attaching by scanning takes long. UBI will not automatically install
3564 a fastmap on old images, but you can set the UBI parameter
3565 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3566 that fastmap-enabled images are still usable with UBI implementations
3567 without fastmap support. On typical flash devices the whole fastmap
3568 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3570 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3571 Set this parameter to enable fastmap automatically on images
3578 Adds commands for interacting with UBI volumes formatted as
3579 UBIFS. UBIFS is read-only in u-boot.
3581 Requires UBI support as well as CONFIG_LZO
3583 CONFIG_UBIFS_SILENCE_MSG
3585 Make the verbose messages from UBIFS stop printing. This leaves
3586 warnings and errors enabled.
3590 Enable building of SPL globally.
3593 LDSCRIPT for linking the SPL binary.
3595 CONFIG_SPL_MAX_FOOTPRINT
3596 Maximum size in memory allocated to the SPL, BSS included.
3597 When defined, the linker checks that the actual memory
3598 used by SPL from _start to __bss_end does not exceed it.
3599 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3600 must not be both defined at the same time.
3603 Maximum size of the SPL image (text, data, rodata, and
3604 linker lists sections), BSS excluded.
3605 When defined, the linker checks that the actual size does
3608 CONFIG_SPL_TEXT_BASE
3609 TEXT_BASE for linking the SPL binary.
3611 CONFIG_SPL_RELOC_TEXT_BASE
3612 Address to relocate to. If unspecified, this is equal to
3613 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3615 CONFIG_SPL_BSS_START_ADDR
3616 Link address for the BSS within the SPL binary.
3618 CONFIG_SPL_BSS_MAX_SIZE
3619 Maximum size in memory allocated to the SPL BSS.
3620 When defined, the linker checks that the actual memory used
3621 by SPL from __bss_start to __bss_end does not exceed it.
3622 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3623 must not be both defined at the same time.
3626 Adress of the start of the stack SPL will use
3628 CONFIG_SPL_RELOC_STACK
3629 Adress of the start of the stack SPL will use after
3630 relocation. If unspecified, this is equal to
3633 CONFIG_SYS_SPL_MALLOC_START
3634 Starting address of the malloc pool used in SPL.
3636 CONFIG_SYS_SPL_MALLOC_SIZE
3637 The size of the malloc pool used in SPL.
3639 CONFIG_SPL_FRAMEWORK
3640 Enable the SPL framework under common/. This framework
3641 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3642 NAND loading of the Linux Kernel.
3645 Enable booting directly to an OS from SPL.
3646 See also: doc/README.falcon
3648 CONFIG_SPL_DISPLAY_PRINT
3649 For ARM, enable an optional function to print more information
3650 about the running system.
3652 CONFIG_SPL_INIT_MINIMAL
3653 Arch init code should be built for a very small image
3655 CONFIG_SPL_LIBCOMMON_SUPPORT
3656 Support for common/libcommon.o in SPL binary
3658 CONFIG_SPL_LIBDISK_SUPPORT
3659 Support for disk/libdisk.o in SPL binary
3661 CONFIG_SPL_I2C_SUPPORT
3662 Support for drivers/i2c/libi2c.o in SPL binary
3664 CONFIG_SPL_GPIO_SUPPORT
3665 Support for drivers/gpio/libgpio.o in SPL binary
3667 CONFIG_SPL_MMC_SUPPORT
3668 Support for drivers/mmc/libmmc.o in SPL binary
3670 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3671 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3672 Address and partition on the MMC to load U-Boot from
3673 when the MMC is being used in raw mode.
3675 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3676 Partition on the MMC to load U-Boot from when the MMC is being
3679 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3680 Sector to load kernel uImage from when MMC is being
3681 used in raw mode (for Falcon mode)
3683 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3684 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3685 Sector and number of sectors to load kernel argument
3686 parameters from when MMC is being used in raw mode
3689 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3690 Partition on the MMC to load U-Boot from when the MMC is being
3693 CONFIG_SPL_FAT_SUPPORT
3694 Support for fs/fat/libfat.o in SPL binary
3696 CONFIG_SPL_EXT_SUPPORT
3697 Support for EXT filesystem in SPL binary
3699 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3700 Filename to read to load U-Boot when reading from filesystem
3702 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3703 Filename to read to load kernel uImage when reading
3704 from filesystem (for Falcon mode)
3706 CONFIG_SPL_FS_LOAD_ARGS_NAME
3707 Filename to read to load kernel argument parameters
3708 when reading from filesystem (for Falcon mode)
3710 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3711 Set this for NAND SPL on PPC mpc83xx targets, so that
3712 start.S waits for the rest of the SPL to load before
3713 continuing (the hardware starts execution after just
3714 loading the first page rather than the full 4K).
3716 CONFIG_SPL_SKIP_RELOCATE
3717 Avoid SPL relocation
3719 CONFIG_SPL_NAND_BASE
3720 Include nand_base.c in the SPL. Requires
3721 CONFIG_SPL_NAND_DRIVERS.
3723 CONFIG_SPL_NAND_DRIVERS
3724 SPL uses normal NAND drivers, not minimal drivers.
3727 Include standard software ECC in the SPL
3729 CONFIG_SPL_NAND_SIMPLE
3730 Support for NAND boot using simple NAND drivers that
3731 expose the cmd_ctrl() interface.
3733 CONFIG_SPL_MTD_SUPPORT
3734 Support for the MTD subsystem within SPL. Useful for
3735 environment on NAND support within SPL.
3737 CONFIG_SPL_NAND_RAW_ONLY
3738 Support to boot only raw u-boot.bin images. Use this only
3739 if you need to save space.
3741 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3742 Set for the SPL on PPC mpc8xxx targets, support for
3743 drivers/ddr/fsl/libddr.o in SPL binary.
3745 CONFIG_SPL_COMMON_INIT_DDR
3746 Set for common ddr init with serial presence detect in
3749 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3750 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3751 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3752 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3753 CONFIG_SYS_NAND_ECCBYTES
3754 Defines the size and behavior of the NAND that SPL uses
3757 CONFIG_SPL_NAND_BOOT
3758 Add support NAND boot
3760 CONFIG_SYS_NAND_U_BOOT_OFFS
3761 Location in NAND to read U-Boot from
3763 CONFIG_SYS_NAND_U_BOOT_DST
3764 Location in memory to load U-Boot to
3766 CONFIG_SYS_NAND_U_BOOT_SIZE
3767 Size of image to load
3769 CONFIG_SYS_NAND_U_BOOT_START
3770 Entry point in loaded image to jump to
3772 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3773 Define this if you need to first read the OOB and then the
3774 data. This is used, for example, on davinci platforms.
3776 CONFIG_SPL_OMAP3_ID_NAND
3777 Support for an OMAP3-specific set of functions to return the
3778 ID and MFR of the first attached NAND chip, if present.
3780 CONFIG_SPL_SERIAL_SUPPORT
3781 Support for drivers/serial/libserial.o in SPL binary
3783 CONFIG_SPL_SPI_FLASH_SUPPORT
3784 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3786 CONFIG_SPL_SPI_SUPPORT
3787 Support for drivers/spi/libspi.o in SPL binary
3789 CONFIG_SPL_RAM_DEVICE
3790 Support for running image already present in ram, in SPL binary
3792 CONFIG_SPL_LIBGENERIC_SUPPORT
3793 Support for lib/libgeneric.o in SPL binary
3795 CONFIG_SPL_ENV_SUPPORT
3796 Support for the environment operating in SPL binary
3798 CONFIG_SPL_NET_SUPPORT
3799 Support for the net/libnet.o in SPL binary.
3800 It conflicts with SPL env from storage medium specified by
3801 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3804 Image offset to which the SPL should be padded before appending
3805 the SPL payload. By default, this is defined as
3806 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3807 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3808 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3811 Final target image containing SPL and payload. Some SPLs
3812 use an arch-specific makefile fragment instead, for
3813 example if more than one image needs to be produced.
3815 CONFIG_FIT_SPL_PRINT
3816 Printing information about a FIT image adds quite a bit of
3817 code to SPL. So this is normally disabled in SPL. Use this
3818 option to re-enable it. This will affect the output of the
3819 bootm command when booting a FIT image.
3823 Enable building of TPL globally.
3826 Image offset to which the TPL should be padded before appending
3827 the TPL payload. By default, this is defined as
3828 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3829 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3830 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3835 [so far only for SMDK2400 boards]
3837 - Modem support enable:
3838 CONFIG_MODEM_SUPPORT
3840 - RTS/CTS Flow control enable:
3843 - Modem debug support:
3844 CONFIG_MODEM_SUPPORT_DEBUG
3846 Enables debugging stuff (char screen[1024], dbg())
3847 for modem support. Useful only with BDI2000.
3849 - Interrupt support (PPC):
3851 There are common interrupt_init() and timer_interrupt()
3852 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3853 for CPU specific initialization. interrupt_init_cpu()
3854 should set decrementer_count to appropriate value. If
3855 CPU resets decrementer automatically after interrupt
3856 (ppc4xx) it should set decrementer_count to zero.
3857 timer_interrupt() calls timer_interrupt_cpu() for CPU
3858 specific handling. If board has watchdog / status_led
3859 / other_activity_monitor it works automatically from
3860 general timer_interrupt().
3864 In the target system modem support is enabled when a
3865 specific key (key combination) is pressed during
3866 power-on. Otherwise U-Boot will boot normally
3867 (autoboot). The key_pressed() function is called from
3868 board_init(). Currently key_pressed() is a dummy
3869 function, returning 1 and thus enabling modem
3872 If there are no modem init strings in the
3873 environment, U-Boot proceed to autoboot; the
3874 previous output (banner, info printfs) will be
3877 See also: doc/README.Modem
3879 Board initialization settings:
3880 ------------------------------
3882 During Initialization u-boot calls a number of board specific functions
3883 to allow the preparation of board specific prerequisites, e.g. pin setup
3884 before drivers are initialized. To enable these callbacks the
3885 following configuration macros have to be defined. Currently this is
3886 architecture specific, so please check arch/your_architecture/lib/board.c
3887 typically in board_init_f() and board_init_r().
3889 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3890 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3891 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3892 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3894 Configuration Settings:
3895 -----------------------
3897 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3898 Optionally it can be defined to support 64-bit memory commands.
3900 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3901 undefine this when you're short of memory.
3903 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3904 width of the commands listed in the 'help' command output.
3906 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3907 prompt for user input.
3909 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3911 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3913 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3915 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3916 the application (usually a Linux kernel) when it is
3919 - CONFIG_SYS_BAUDRATE_TABLE:
3920 List of legal baudrate settings for this board.
3922 - CONFIG_SYS_CONSOLE_INFO_QUIET
3923 Suppress display of console information at boot.
3925 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3926 If the board specific function
3927 extern int overwrite_console (void);
3928 returns 1, the stdin, stderr and stdout are switched to the
3929 serial port, else the settings in the environment are used.
3931 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3932 Enable the call to overwrite_console().
3934 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3935 Enable overwrite of previous console environment settings.
3937 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3938 Begin and End addresses of the area used by the
3941 - CONFIG_SYS_ALT_MEMTEST:
3942 Enable an alternate, more extensive memory test.
3944 - CONFIG_SYS_MEMTEST_SCRATCH:
3945 Scratch address used by the alternate memory test
3946 You only need to set this if address zero isn't writeable
3948 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3949 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3950 this specified memory area will get subtracted from the top
3951 (end) of RAM and won't get "touched" at all by U-Boot. By
3952 fixing up gd->ram_size the Linux kernel should gets passed
3953 the now "corrected" memory size and won't touch it either.
3954 This should work for arch/ppc and arch/powerpc. Only Linux
3955 board ports in arch/powerpc with bootwrapper support that
3956 recalculate the memory size from the SDRAM controller setup
3957 will have to get fixed in Linux additionally.
3959 This option can be used as a workaround for the 440EPx/GRx
3960 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3963 WARNING: Please make sure that this value is a multiple of
3964 the Linux page size (normally 4k). If this is not the case,
3965 then the end address of the Linux memory will be located at a
3966 non page size aligned address and this could cause major
3969 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3970 Enable temporary baudrate change while serial download
3972 - CONFIG_SYS_SDRAM_BASE:
3973 Physical start address of SDRAM. _Must_ be 0 here.
3975 - CONFIG_SYS_MBIO_BASE:
3976 Physical start address of Motherboard I/O (if using a
3979 - CONFIG_SYS_FLASH_BASE:
3980 Physical start address of Flash memory.
3982 - CONFIG_SYS_MONITOR_BASE:
3983 Physical start address of boot monitor code (set by
3984 make config files to be same as the text base address
3985 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3986 CONFIG_SYS_FLASH_BASE when booting from flash.
3988 - CONFIG_SYS_MONITOR_LEN:
3989 Size of memory reserved for monitor code, used to
3990 determine _at_compile_time_ (!) if the environment is
3991 embedded within the U-Boot image, or in a separate
3994 - CONFIG_SYS_MALLOC_LEN:
3995 Size of DRAM reserved for malloc() use.
3997 - CONFIG_SYS_MALLOC_F_LEN
3998 Size of the malloc() pool for use before relocation. If
3999 this is defined, then a very simple malloc() implementation
4000 will become available before relocation. The address is just
4001 below the global data, and the stack is moved down to make
4004 This feature allocates regions with increasing addresses
4005 within the region. calloc() is supported, but realloc()
4006 is not available. free() is supported but does nothing.
4007 The memory will be freed (or in fact just forgotten) when
4008 U-Boot relocates itself.
4010 Pre-relocation malloc() is only supported on ARM and sandbox
4011 at present but is fairly easy to enable for other archs.
4013 - CONFIG_SYS_MALLOC_SIMPLE
4014 Provides a simple and small malloc() and calloc() for those
4015 boards which do not use the full malloc in SPL (which is
4016 enabled with CONFIG_SYS_SPL_MALLOC_START).
4018 - CONFIG_SYS_NONCACHED_MEMORY:
4019 Size of non-cached memory area. This area of memory will be
4020 typically located right below the malloc() area and mapped
4021 uncached in the MMU. This is useful for drivers that would
4022 otherwise require a lot of explicit cache maintenance. For
4023 some drivers it's also impossible to properly maintain the
4024 cache. For example if the regions that need to be flushed
4025 are not a multiple of the cache-line size, *and* padding
4026 cannot be allocated between the regions to align them (i.e.
4027 if the HW requires a contiguous array of regions, and the
4028 size of each region is not cache-aligned), then a flush of
4029 one region may result in overwriting data that hardware has
4030 written to another region in the same cache-line. This can
4031 happen for example in network drivers where descriptors for
4032 buffers are typically smaller than the CPU cache-line (e.g.
4033 16 bytes vs. 32 or 64 bytes).
4035 Non-cached memory is only supported on 32-bit ARM at present.
4037 - CONFIG_SYS_BOOTM_LEN:
4038 Normally compressed uImages are limited to an
4039 uncompressed size of 8 MBytes. If this is not enough,
4040 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4041 to adjust this setting to your needs.
4043 - CONFIG_SYS_BOOTMAPSZ:
4044 Maximum size of memory mapped by the startup code of
4045 the Linux kernel; all data that must be processed by
4046 the Linux kernel (bd_info, boot arguments, FDT blob if
4047 used) must be put below this limit, unless "bootm_low"
4048 environment variable is defined and non-zero. In such case
4049 all data for the Linux kernel must be between "bootm_low"
4050 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4051 variable "bootm_mapsize" will override the value of
4052 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4053 then the value in "bootm_size" will be used instead.
4055 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4056 Enable initrd_high functionality. If defined then the
4057 initrd_high feature is enabled and the bootm ramdisk subcommand
4060 - CONFIG_SYS_BOOT_GET_CMDLINE:
4061 Enables allocating and saving kernel cmdline in space between
4062 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4064 - CONFIG_SYS_BOOT_GET_KBD:
4065 Enables allocating and saving a kernel copy of the bd_info in
4066 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4068 - CONFIG_SYS_MAX_FLASH_BANKS:
4069 Max number of Flash memory banks
4071 - CONFIG_SYS_MAX_FLASH_SECT:
4072 Max number of sectors on a Flash chip
4074 - CONFIG_SYS_FLASH_ERASE_TOUT:
4075 Timeout for Flash erase operations (in ms)
4077 - CONFIG_SYS_FLASH_WRITE_TOUT:
4078 Timeout for Flash write operations (in ms)
4080 - CONFIG_SYS_FLASH_LOCK_TOUT
4081 Timeout for Flash set sector lock bit operation (in ms)
4083 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4084 Timeout for Flash clear lock bits operation (in ms)
4086 - CONFIG_SYS_FLASH_PROTECTION
4087 If defined, hardware flash sectors protection is used
4088 instead of U-Boot software protection.
4090 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4092 Enable TFTP transfers directly to flash memory;
4093 without this option such a download has to be
4094 performed in two steps: (1) download to RAM, and (2)
4095 copy from RAM to flash.
4097 The two-step approach is usually more reliable, since
4098 you can check if the download worked before you erase
4099 the flash, but in some situations (when system RAM is
4100 too limited to allow for a temporary copy of the
4101 downloaded image) this option may be very useful.
4103 - CONFIG_SYS_FLASH_CFI:
4104 Define if the flash driver uses extra elements in the
4105 common flash structure for storing flash geometry.
4107 - CONFIG_FLASH_CFI_DRIVER
4108 This option also enables the building of the cfi_flash driver
4109 in the drivers directory
4111 - CONFIG_FLASH_CFI_MTD
4112 This option enables the building of the cfi_mtd driver
4113 in the drivers directory. The driver exports CFI flash
4116 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4117 Use buffered writes to flash.
4119 - CONFIG_FLASH_SPANSION_S29WS_N
4120 s29ws-n MirrorBit flash has non-standard addresses for buffered
4123 - CONFIG_SYS_FLASH_QUIET_TEST
4124 If this option is defined, the common CFI flash doesn't
4125 print it's warning upon not recognized FLASH banks. This
4126 is useful, if some of the configured banks are only
4127 optionally available.
4129 - CONFIG_FLASH_SHOW_PROGRESS
4130 If defined (must be an integer), print out countdown
4131 digits and dots. Recommended value: 45 (9..1) for 80
4132 column displays, 15 (3..1) for 40 column displays.
4134 - CONFIG_FLASH_VERIFY
4135 If defined, the content of the flash (destination) is compared
4136 against the source after the write operation. An error message
4137 will be printed when the contents are not identical.
4138 Please note that this option is useless in nearly all cases,
4139 since such flash programming errors usually are detected earlier
4140 while unprotecting/erasing/programming. Please only enable
4141 this option if you really know what you are doing.
4143 - CONFIG_SYS_RX_ETH_BUFFER:
4144 Defines the number of Ethernet receive buffers. On some
4145 Ethernet controllers it is recommended to set this value
4146 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4147 buffers can be full shortly after enabling the interface
4148 on high Ethernet traffic.
4149 Defaults to 4 if not defined.
4151 - CONFIG_ENV_MAX_ENTRIES
4153 Maximum number of entries in the hash table that is used
4154 internally to store the environment settings. The default
4155 setting is supposed to be generous and should work in most
4156 cases. This setting can be used to tune behaviour; see
4157 lib/hashtable.c for details.
4159 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4160 - CONFIG_ENV_FLAGS_LIST_STATIC
4161 Enable validation of the values given to environment variables when
4162 calling env set. Variables can be restricted to only decimal,
4163 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4164 the variables can also be restricted to IP address or MAC address.
4166 The format of the list is:
4167 type_attribute = [s|d|x|b|i|m]
4168 access_attribute = [a|r|o|c]
4169 attributes = type_attribute[access_attribute]
4170 entry = variable_name[:attributes]
4173 The type attributes are:
4174 s - String (default)
4177 b - Boolean ([1yYtT|0nNfF])
4181 The access attributes are:
4187 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4188 Define this to a list (string) to define the ".flags"
4189 environment variable in the default or embedded environment.
4191 - CONFIG_ENV_FLAGS_LIST_STATIC
4192 Define this to a list (string) to define validation that
4193 should be done if an entry is not found in the ".flags"
4194 environment variable. To override a setting in the static
4195 list, simply add an entry for the same variable name to the
4198 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4199 If defined, don't allow the -f switch to env set override variable
4202 - CONFIG_SYS_GENERIC_BOARD
4203 This selects the architecture-generic board system instead of the
4204 architecture-specific board files. It is intended to move boards
4205 to this new framework over time. Defining this will disable the
4206 arch/foo/lib/board.c file and use common/board_f.c and
4207 common/board_r.c instead. To use this option your architecture
4208 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4209 its config.mk file). If you find problems enabling this option on
4210 your board please report the problem and send patches!
4212 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4213 This is set by OMAP boards for the max time that reset should
4214 be asserted. See doc/README.omap-reset-time for details on how
4215 the value can be calculated on a given board.
4218 If stdint.h is available with your toolchain you can define this
4219 option to enable it. You can provide option 'USE_STDINT=1' when
4220 building U-Boot to enable this.
4222 The following definitions that deal with the placement and management
4223 of environment data (variable area); in general, we support the
4224 following configurations:
4226 - CONFIG_BUILD_ENVCRC:
4228 Builds up envcrc with the target environment so that external utils
4229 may easily extract it and embed it in final U-Boot images.
4231 - CONFIG_ENV_IS_IN_FLASH:
4233 Define this if the environment is in flash memory.
4235 a) The environment occupies one whole flash sector, which is
4236 "embedded" in the text segment with the U-Boot code. This
4237 happens usually with "bottom boot sector" or "top boot
4238 sector" type flash chips, which have several smaller
4239 sectors at the start or the end. For instance, such a
4240 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4241 such a case you would place the environment in one of the
4242 4 kB sectors - with U-Boot code before and after it. With
4243 "top boot sector" type flash chips, you would put the
4244 environment in one of the last sectors, leaving a gap
4245 between U-Boot and the environment.
4247 - CONFIG_ENV_OFFSET:
4249 Offset of environment data (variable area) to the
4250 beginning of flash memory; for instance, with bottom boot
4251 type flash chips the second sector can be used: the offset
4252 for this sector is given here.
4254 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4258 This is just another way to specify the start address of
4259 the flash sector containing the environment (instead of
4262 - CONFIG_ENV_SECT_SIZE:
4264 Size of the sector containing the environment.
4267 b) Sometimes flash chips have few, equal sized, BIG sectors.
4268 In such a case you don't want to spend a whole sector for
4273 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4274 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4275 of this flash sector for the environment. This saves
4276 memory for the RAM copy of the environment.
4278 It may also save flash memory if you decide to use this
4279 when your environment is "embedded" within U-Boot code,
4280 since then the remainder of the flash sector could be used
4281 for U-Boot code. It should be pointed out that this is
4282 STRONGLY DISCOURAGED from a robustness point of view:
4283 updating the environment in flash makes it always
4284 necessary to erase the WHOLE sector. If something goes
4285 wrong before the contents has been restored from a copy in
4286 RAM, your target system will be dead.
4288 - CONFIG_ENV_ADDR_REDUND
4289 CONFIG_ENV_SIZE_REDUND
4291 These settings describe a second storage area used to hold
4292 a redundant copy of the environment data, so that there is
4293 a valid backup copy in case there is a power failure during
4294 a "saveenv" operation.
4296 BE CAREFUL! Any changes to the flash layout, and some changes to the
4297 source code will make it necessary to adapt <board>/u-boot.lds*
4301 - CONFIG_ENV_IS_IN_NVRAM:
4303 Define this if you have some non-volatile memory device
4304 (NVRAM, battery buffered SRAM) which you want to use for the
4310 These two #defines are used to determine the memory area you
4311 want to use for environment. It is assumed that this memory
4312 can just be read and written to, without any special
4315 BE CAREFUL! The first access to the environment happens quite early
4316 in U-Boot initialization (when we try to get the setting of for the
4317 console baudrate). You *MUST* have mapped your NVRAM area then, or
4320 Please note that even with NVRAM we still use a copy of the
4321 environment in RAM: we could work on NVRAM directly, but we want to
4322 keep settings there always unmodified except somebody uses "saveenv"
4323 to save the current settings.
4326 - CONFIG_ENV_IS_IN_EEPROM:
4328 Use this if you have an EEPROM or similar serial access
4329 device and a driver for it.
4331 - CONFIG_ENV_OFFSET:
4334 These two #defines specify the offset and size of the
4335 environment area within the total memory of your EEPROM.
4337 - CONFIG_SYS_I2C_EEPROM_ADDR:
4338 If defined, specified the chip address of the EEPROM device.
4339 The default address is zero.
4341 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4342 If defined, the number of bits used to address bytes in a
4343 single page in the EEPROM device. A 64 byte page, for example
4344 would require six bits.
4346 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4347 If defined, the number of milliseconds to delay between
4348 page writes. The default is zero milliseconds.
4350 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4351 The length in bytes of the EEPROM memory array address. Note
4352 that this is NOT the chip address length!
4354 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4355 EEPROM chips that implement "address overflow" are ones
4356 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4357 address and the extra bits end up in the "chip address" bit
4358 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4361 Note that we consider the length of the address field to
4362 still be one byte because the extra address bits are hidden
4363 in the chip address.
4365 - CONFIG_SYS_EEPROM_SIZE:
4366 The size in bytes of the EEPROM device.
4368 - CONFIG_ENV_EEPROM_IS_ON_I2C
4369 define this, if you have I2C and SPI activated, and your
4370 EEPROM, which holds the environment, is on the I2C bus.
4372 - CONFIG_I2C_ENV_EEPROM_BUS
4373 if you have an Environment on an EEPROM reached over
4374 I2C muxes, you can define here, how to reach this
4375 EEPROM. For example:
4377 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4379 EEPROM which holds the environment, is reached over
4380 a pca9547 i2c mux with address 0x70, channel 3.
4382 - CONFIG_ENV_IS_IN_DATAFLASH:
4384 Define this if you have a DataFlash memory device which you
4385 want to use for the environment.
4387 - CONFIG_ENV_OFFSET:
4391 These three #defines specify the offset and size of the
4392 environment area within the total memory of your DataFlash placed
4393 at the specified address.
4395 - CONFIG_ENV_IS_IN_SPI_FLASH:
4397 Define this if you have a SPI Flash memory device which you
4398 want to use for the environment.
4400 - CONFIG_ENV_OFFSET:
4403 These two #defines specify the offset and size of the
4404 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4405 aligned to an erase sector boundary.
4407 - CONFIG_ENV_SECT_SIZE:
4409 Define the SPI flash's sector size.
4411 - CONFIG_ENV_OFFSET_REDUND (optional):
4413 This setting describes a second storage area of CONFIG_ENV_SIZE
4414 size used to hold a redundant copy of the environment data, so
4415 that there is a valid backup copy in case there is a power failure
4416 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4417 aligned to an erase sector boundary.
4419 - CONFIG_ENV_SPI_BUS (optional):
4420 - CONFIG_ENV_SPI_CS (optional):
4422 Define the SPI bus and chip select. If not defined they will be 0.
4424 - CONFIG_ENV_SPI_MAX_HZ (optional):
4426 Define the SPI max work clock. If not defined then use 1MHz.
4428 - CONFIG_ENV_SPI_MODE (optional):
4430 Define the SPI work mode. If not defined then use SPI_MODE_3.
4432 - CONFIG_ENV_IS_IN_REMOTE:
4434 Define this if you have a remote memory space which you
4435 want to use for the local device's environment.
4440 These two #defines specify the address and size of the
4441 environment area within the remote memory space. The
4442 local device can get the environment from remote memory
4443 space by SRIO or PCIE links.
4445 BE CAREFUL! For some special cases, the local device can not use
4446 "saveenv" command. For example, the local device will get the
4447 environment stored in a remote NOR flash by SRIO or PCIE link,
4448 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4450 - CONFIG_ENV_IS_IN_NAND:
4452 Define this if you have a NAND device which you want to use
4453 for the environment.
4455 - CONFIG_ENV_OFFSET:
4458 These two #defines specify the offset and size of the environment
4459 area within the first NAND device. CONFIG_ENV_OFFSET must be
4460 aligned to an erase block boundary.
4462 - CONFIG_ENV_OFFSET_REDUND (optional):
4464 This setting describes a second storage area of CONFIG_ENV_SIZE
4465 size used to hold a redundant copy of the environment data, so
4466 that there is a valid backup copy in case there is a power failure
4467 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4468 aligned to an erase block boundary.
4470 - CONFIG_ENV_RANGE (optional):
4472 Specifies the length of the region in which the environment
4473 can be written. This should be a multiple of the NAND device's
4474 block size. Specifying a range with more erase blocks than
4475 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4476 the range to be avoided.
4478 - CONFIG_ENV_OFFSET_OOB (optional):
4480 Enables support for dynamically retrieving the offset of the
4481 environment from block zero's out-of-band data. The
4482 "nand env.oob" command can be used to record this offset.
4483 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4484 using CONFIG_ENV_OFFSET_OOB.
4486 - CONFIG_NAND_ENV_DST
4488 Defines address in RAM to which the nand_spl code should copy the
4489 environment. If redundant environment is used, it will be copied to
4490 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4492 - CONFIG_ENV_IS_IN_UBI:
4494 Define this if you have an UBI volume that you want to use for the
4495 environment. This has the benefit of wear-leveling the environment
4496 accesses, which is important on NAND.
4498 - CONFIG_ENV_UBI_PART:
4500 Define this to a string that is the mtd partition containing the UBI.
4502 - CONFIG_ENV_UBI_VOLUME:
4504 Define this to the name of the volume that you want to store the
4507 - CONFIG_ENV_UBI_VOLUME_REDUND:
4509 Define this to the name of another volume to store a second copy of
4510 the environment in. This will enable redundant environments in UBI.
4511 It is assumed that both volumes are in the same MTD partition.
4513 - CONFIG_UBI_SILENCE_MSG
4514 - CONFIG_UBIFS_SILENCE_MSG
4516 You will probably want to define these to avoid a really noisy system
4517 when storing the env in UBI.
4519 - CONFIG_ENV_IS_IN_FAT:
4520 Define this if you want to use the FAT file system for the environment.
4522 - FAT_ENV_INTERFACE:
4524 Define this to a string that is the name of the block device.
4526 - FAT_ENV_DEV_AND_PART:
4528 Define this to a string to specify the partition of the device. It can
4531 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4532 - "D:P": device D partition P. Error occurs if device D has no
4535 - "D" or "D:": device D partition 1 if device D has partition
4536 table, or the whole device D if has no partition
4538 - "D:auto": first partition in device D with bootable flag set.
4539 If none, first valid partition in device D. If no
4540 partition table then means device D.
4544 It's a string of the FAT file name. This file use to store the
4548 This should be defined. Otherwise it cannot save the environment file.
4550 - CONFIG_ENV_IS_IN_MMC:
4552 Define this if you have an MMC device which you want to use for the
4555 - CONFIG_SYS_MMC_ENV_DEV:
4557 Specifies which MMC device the environment is stored in.
4559 - CONFIG_SYS_MMC_ENV_PART (optional):
4561 Specifies which MMC partition the environment is stored in. If not
4562 set, defaults to partition 0, the user area. Common values might be
4563 1 (first MMC boot partition), 2 (second MMC boot partition).
4565 - CONFIG_ENV_OFFSET:
4568 These two #defines specify the offset and size of the environment
4569 area within the specified MMC device.
4571 If offset is positive (the usual case), it is treated as relative to
4572 the start of the MMC partition. If offset is negative, it is treated
4573 as relative to the end of the MMC partition. This can be useful if
4574 your board may be fitted with different MMC devices, which have
4575 different sizes for the MMC partitions, and you always want the
4576 environment placed at the very end of the partition, to leave the
4577 maximum possible space before it, to store other data.
4579 These two values are in units of bytes, but must be aligned to an
4580 MMC sector boundary.
4582 - CONFIG_ENV_OFFSET_REDUND (optional):
4584 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4585 hold a redundant copy of the environment data. This provides a
4586 valid backup copy in case the other copy is corrupted, e.g. due
4587 to a power failure during a "saveenv" operation.
4589 This value may also be positive or negative; this is handled in the
4590 same way as CONFIG_ENV_OFFSET.
4592 This value is also in units of bytes, but must also be aligned to
4593 an MMC sector boundary.
4595 - CONFIG_ENV_SIZE_REDUND (optional):
4597 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4598 set. If this value is set, it must be set to the same value as
4601 - CONFIG_SYS_SPI_INIT_OFFSET
4603 Defines offset to the initial SPI buffer area in DPRAM. The
4604 area is used at an early stage (ROM part) if the environment
4605 is configured to reside in the SPI EEPROM: We need a 520 byte
4606 scratch DPRAM area. It is used between the two initialization
4607 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4608 to be a good choice since it makes it far enough from the
4609 start of the data area as well as from the stack pointer.
4611 Please note that the environment is read-only until the monitor
4612 has been relocated to RAM and a RAM copy of the environment has been
4613 created; also, when using EEPROM you will have to use getenv_f()
4614 until then to read environment variables.
4616 The environment is protected by a CRC32 checksum. Before the monitor
4617 is relocated into RAM, as a result of a bad CRC you will be working
4618 with the compiled-in default environment - *silently*!!! [This is
4619 necessary, because the first environment variable we need is the
4620 "baudrate" setting for the console - if we have a bad CRC, we don't
4621 have any device yet where we could complain.]
4623 Note: once the monitor has been relocated, then it will complain if
4624 the default environment is used; a new CRC is computed as soon as you
4625 use the "saveenv" command to store a valid environment.
4627 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4628 Echo the inverted Ethernet link state to the fault LED.
4630 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4631 also needs to be defined.
4633 - CONFIG_SYS_FAULT_MII_ADDR:
4634 MII address of the PHY to check for the Ethernet link state.
4636 - CONFIG_NS16550_MIN_FUNCTIONS:
4637 Define this if you desire to only have use of the NS16550_init
4638 and NS16550_putc functions for the serial driver located at
4639 drivers/serial/ns16550.c. This option is useful for saving
4640 space for already greatly restricted images, including but not
4641 limited to NAND_SPL configurations.
4643 - CONFIG_DISPLAY_BOARDINFO
4644 Display information about the board that U-Boot is running on
4645 when U-Boot starts up. The board function checkboard() is called
4648 - CONFIG_DISPLAY_BOARDINFO_LATE
4649 Similar to the previous option, but display this information
4650 later, once stdio is running and output goes to the LCD, if
4653 - CONFIG_BOARD_SIZE_LIMIT:
4654 Maximum size of the U-Boot image. When defined, the
4655 build system checks that the actual size does not
4658 Low Level (hardware related) configuration options:
4659 ---------------------------------------------------
4661 - CONFIG_SYS_CACHELINE_SIZE:
4662 Cache Line Size of the CPU.
4664 - CONFIG_SYS_DEFAULT_IMMR:
4665 Default address of the IMMR after system reset.
4667 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4668 and RPXsuper) to be able to adjust the position of
4669 the IMMR register after a reset.
4671 - CONFIG_SYS_CCSRBAR_DEFAULT:
4672 Default (power-on reset) physical address of CCSR on Freescale
4675 - CONFIG_SYS_CCSRBAR:
4676 Virtual address of CCSR. On a 32-bit build, this is typically
4677 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4679 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4680 for cross-platform code that uses that macro instead.
4682 - CONFIG_SYS_CCSRBAR_PHYS:
4683 Physical address of CCSR. CCSR can be relocated to a new
4684 physical address, if desired. In this case, this macro should
4685 be set to that address. Otherwise, it should be set to the
4686 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4687 is typically relocated on 36-bit builds. It is recommended
4688 that this macro be defined via the _HIGH and _LOW macros:
4690 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4691 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4693 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4694 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4695 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4696 used in assembly code, so it must not contain typecasts or
4697 integer size suffixes (e.g. "ULL").
4699 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4700 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4701 used in assembly code, so it must not contain typecasts or
4702 integer size suffixes (e.g. "ULL").
4704 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4705 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4706 forced to a value that ensures that CCSR is not relocated.
4708 - Floppy Disk Support:
4709 CONFIG_SYS_FDC_DRIVE_NUMBER
4711 the default drive number (default value 0)
4713 CONFIG_SYS_ISA_IO_STRIDE
4715 defines the spacing between FDC chipset registers
4718 CONFIG_SYS_ISA_IO_OFFSET
4720 defines the offset of register from address. It
4721 depends on which part of the data bus is connected to
4722 the FDC chipset. (default value 0)
4724 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4725 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4728 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4729 fdc_hw_init() is called at the beginning of the FDC
4730 setup. fdc_hw_init() must be provided by the board
4731 source code. It is used to make hardware-dependent
4735 Most IDE controllers were designed to be connected with PCI
4736 interface. Only few of them were designed for AHB interface.
4737 When software is doing ATA command and data transfer to
4738 IDE devices through IDE-AHB controller, some additional
4739 registers accessing to these kind of IDE-AHB controller
4742 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4743 DO NOT CHANGE unless you know exactly what you're
4744 doing! (11-4) [MPC8xx/82xx systems only]
4746 - CONFIG_SYS_INIT_RAM_ADDR:
4748 Start address of memory area that can be used for
4749 initial data and stack; please note that this must be
4750 writable memory that is working WITHOUT special
4751 initialization, i. e. you CANNOT use normal RAM which
4752 will become available only after programming the
4753 memory controller and running certain initialization
4756 U-Boot uses the following memory types:
4757 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4758 - MPC824X: data cache
4759 - PPC4xx: data cache
4761 - CONFIG_SYS_GBL_DATA_OFFSET:
4763 Offset of the initial data structure in the memory
4764 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4765 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4766 data is located at the end of the available space
4767 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4768 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4769 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4770 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4773 On the MPC824X (or other systems that use the data
4774 cache for initial memory) the address chosen for
4775 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4776 point to an otherwise UNUSED address space between
4777 the top of RAM and the start of the PCI space.
4779 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4781 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4783 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4785 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4787 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4789 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4791 - CONFIG_SYS_OR_TIMING_SDRAM:
4794 - CONFIG_SYS_MAMR_PTA:
4795 periodic timer for refresh
4797 - CONFIG_SYS_DER: Debug Event Register (37-47)
4799 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4800 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4801 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4802 CONFIG_SYS_BR1_PRELIM:
4803 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4805 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4806 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4807 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4808 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4810 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4811 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4812 Machine Mode Register and Memory Periodic Timer
4813 Prescaler definitions (SDRAM timing)
4815 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4816 enable I2C microcode relocation patch (MPC8xx);
4817 define relocation offset in DPRAM [DSP2]
4819 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4820 enable SMC microcode relocation patch (MPC8xx);
4821 define relocation offset in DPRAM [SMC1]
4823 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4824 enable SPI microcode relocation patch (MPC8xx);
4825 define relocation offset in DPRAM [SCC4]
4827 - CONFIG_SYS_USE_OSCCLK:
4828 Use OSCM clock mode on MBX8xx board. Be careful,
4829 wrong setting might damage your board. Read
4830 doc/README.MBX before setting this variable!
4832 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4833 Offset of the bootmode word in DPRAM used by post
4834 (Power On Self Tests). This definition overrides
4835 #define'd default value in commproc.h resp.
4838 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4839 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4840 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4841 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4842 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4843 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4844 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4845 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4846 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4848 - CONFIG_PCI_DISABLE_PCIE:
4849 Disable PCI-Express on systems where it is supported but not
4852 - CONFIG_PCI_ENUM_ONLY
4853 Only scan through and get the devices on the buses.
4854 Don't do any setup work, presumably because someone or
4855 something has already done it, and we don't need to do it
4856 a second time. Useful for platforms that are pre-booted
4857 by coreboot or similar.
4859 - CONFIG_PCI_INDIRECT_BRIDGE:
4860 Enable support for indirect PCI bridges.
4863 Chip has SRIO or not
4866 Board has SRIO 1 port available
4869 Board has SRIO 2 port available
4871 - CONFIG_SRIO_PCIE_BOOT_MASTER
4872 Board can support master function for Boot from SRIO and PCIE
4874 - CONFIG_SYS_SRIOn_MEM_VIRT:
4875 Virtual Address of SRIO port 'n' memory region
4877 - CONFIG_SYS_SRIOn_MEM_PHYS:
4878 Physical Address of SRIO port 'n' memory region
4880 - CONFIG_SYS_SRIOn_MEM_SIZE:
4881 Size of SRIO port 'n' memory region
4883 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4884 Defined to tell the NAND controller that the NAND chip is using
4886 Not all NAND drivers use this symbol.
4887 Example of drivers that use it:
4888 - drivers/mtd/nand/ndfc.c
4889 - drivers/mtd/nand/mxc_nand.c
4891 - CONFIG_SYS_NDFC_EBC0_CFG
4892 Sets the EBC0_CFG register for the NDFC. If not defined
4893 a default value will be used.
4896 Get DDR timing information from an I2C EEPROM. Common
4897 with pluggable memory modules such as SODIMMs
4900 I2C address of the SPD EEPROM
4902 - CONFIG_SYS_SPD_BUS_NUM
4903 If SPD EEPROM is on an I2C bus other than the first
4904 one, specify here. Note that the value must resolve
4905 to something your driver can deal with.
4907 - CONFIG_SYS_DDR_RAW_TIMING
4908 Get DDR timing information from other than SPD. Common with
4909 soldered DDR chips onboard without SPD. DDR raw timing
4910 parameters are extracted from datasheet and hard-coded into
4911 header files or board specific files.
4913 - CONFIG_FSL_DDR_INTERACTIVE
4914 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4916 - CONFIG_SYS_83XX_DDR_USES_CS0
4917 Only for 83xx systems. If specified, then DDR should
4918 be configured using CS0 and CS1 instead of CS2 and CS3.
4920 - CONFIG_ETHER_ON_FEC[12]
4921 Define to enable FEC[12] on a 8xx series processor.
4923 - CONFIG_FEC[12]_PHY
4924 Define to the hardcoded PHY address which corresponds
4925 to the given FEC; i. e.
4926 #define CONFIG_FEC1_PHY 4
4927 means that the PHY with address 4 is connected to FEC1
4929 When set to -1, means to probe for first available.
4931 - CONFIG_FEC[12]_PHY_NORXERR
4932 The PHY does not have a RXERR line (RMII only).
4933 (so program the FEC to ignore it).
4936 Enable RMII mode for all FECs.
4937 Note that this is a global option, we can't
4938 have one FEC in standard MII mode and another in RMII mode.
4940 - CONFIG_CRC32_VERIFY
4941 Add a verify option to the crc32 command.
4944 => crc32 -v <address> <count> <crc32>
4946 Where address/count indicate a memory area
4947 and crc32 is the correct crc32 which the
4951 Add the "loopw" memory command. This only takes effect if
4952 the memory commands are activated globally (CONFIG_CMD_MEM).
4955 Add the "mdc" and "mwc" memory commands. These are cyclic
4960 This command will print 4 bytes (10,11,12,13) each 500 ms.
4962 => mwc.l 100 12345678 10
4963 This command will write 12345678 to address 100 all 10 ms.
4965 This only takes effect if the memory commands are activated
4966 globally (CONFIG_CMD_MEM).
4968 - CONFIG_SKIP_LOWLEVEL_INIT
4969 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4970 low level initializations (like setting up the memory
4971 controller) are omitted and/or U-Boot does not
4972 relocate itself into RAM.
4974 Normally this variable MUST NOT be defined. The only
4975 exception is when U-Boot is loaded (to RAM) by some
4976 other boot loader or by a debugger which performs
4977 these initializations itself.
4980 Modifies the behaviour of start.S when compiling a loader
4981 that is executed before the actual U-Boot. E.g. when
4982 compiling a NAND SPL.
4985 Modifies the behaviour of start.S when compiling a loader
4986 that is executed after the SPL and before the actual U-Boot.
4987 It is loaded by the SPL.
4989 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4990 Only for 85xx systems. If this variable is specified, the section
4991 .resetvec is not kept and the section .bootpg is placed in the
4992 previous 4k of the .text section.
4994 - CONFIG_ARCH_MAP_SYSMEM
4995 Generally U-Boot (and in particular the md command) uses
4996 effective address. It is therefore not necessary to regard
4997 U-Boot address as virtual addresses that need to be translated
4998 to physical addresses. However, sandbox requires this, since
4999 it maintains its own little RAM buffer which contains all
5000 addressable memory. This option causes some memory accesses
5001 to be mapped through map_sysmem() / unmap_sysmem().
5003 - CONFIG_USE_ARCH_MEMCPY
5004 CONFIG_USE_ARCH_MEMSET
5005 If these options are used a optimized version of memcpy/memset will
5006 be used if available. These functions may be faster under some
5007 conditions but may increase the binary size.
5009 - CONFIG_X86_RESET_VECTOR
5010 If defined, the x86 reset vector code is included. This is not
5011 needed when U-Boot is running from Coreboot.
5014 Defines the MPU clock speed (in MHz).
5016 NOTE : currently only supported on AM335x platforms.
5018 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5019 Enables the RTC32K OSC on AM33xx based plattforms
5021 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5022 Option to disable subpage write in NAND driver
5023 driver that uses this:
5024 drivers/mtd/nand/davinci_nand.c
5026 Freescale QE/FMAN Firmware Support:
5027 -----------------------------------
5029 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5030 loading of "firmware", which is encoded in the QE firmware binary format.
5031 This firmware often needs to be loaded during U-Boot booting, so macros
5032 are used to identify the storage device (NOR flash, SPI, etc) and the address
5035 - CONFIG_SYS_FMAN_FW_ADDR
5036 The address in the storage device where the FMAN microcode is located. The
5037 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5040 - CONFIG_SYS_QE_FW_ADDR
5041 The address in the storage device where the QE microcode is located. The
5042 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5045 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5046 The maximum possible size of the firmware. The firmware binary format
5047 has a field that specifies the actual size of the firmware, but it
5048 might not be possible to read any part of the firmware unless some
5049 local storage is allocated to hold the entire firmware first.
5051 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5052 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5053 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5054 virtual address in NOR flash.
5056 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5057 Specifies that QE/FMAN firmware is located in NAND flash.
5058 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5060 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5061 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5062 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5064 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5065 Specifies that QE/FMAN firmware is located on the primary SPI
5066 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5068 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5069 Specifies that QE/FMAN firmware is located in the remote (master)
5070 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5071 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5072 window->master inbound window->master LAW->the ucode address in
5073 master's memory space.
5075 Freescale Layerscape Management Complex Firmware Support:
5076 ---------------------------------------------------------
5077 The Freescale Layerscape Management Complex (MC) supports the loading of
5079 This firmware often needs to be loaded during U-Boot booting, so macros
5080 are used to identify the storage device (NOR flash, SPI, etc) and the address
5083 - CONFIG_FSL_MC_ENET
5084 Enable the MC driver for Layerscape SoCs.
5086 - CONFIG_SYS_LS_MC_FW_ADDR
5087 The address in the storage device where the firmware is located. The
5088 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5091 - CONFIG_SYS_LS_MC_FW_LENGTH
5092 The maximum possible size of the firmware. The firmware binary format
5093 has a field that specifies the actual size of the firmware, but it
5094 might not be possible to read any part of the firmware unless some
5095 local storage is allocated to hold the entire firmware first.
5097 - CONFIG_SYS_LS_MC_FW_IN_NOR
5098 Specifies that MC firmware is located in NOR flash, mapped as
5099 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5100 virtual address in NOR flash.
5102 Building the Software:
5103 ======================
5105 Building U-Boot has been tested in several native build environments
5106 and in many different cross environments. Of course we cannot support
5107 all possibly existing versions of cross development tools in all
5108 (potentially obsolete) versions. In case of tool chain problems we
5109 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5110 which is extensively used to build and test U-Boot.
5112 If you are not using a native environment, it is assumed that you
5113 have GNU cross compiling tools available in your path. In this case,
5114 you must set the environment variable CROSS_COMPILE in your shell.
5115 Note that no changes to the Makefile or any other source files are
5116 necessary. For example using the ELDK on a 4xx CPU, please enter:
5118 $ CROSS_COMPILE=ppc_4xx-
5119 $ export CROSS_COMPILE
5121 Note: If you wish to generate Windows versions of the utilities in
5122 the tools directory you can use the MinGW toolchain
5123 (http://www.mingw.org). Set your HOST tools to the MinGW
5124 toolchain and execute 'make tools'. For example:
5126 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5128 Binaries such as tools/mkimage.exe will be created which can
5129 be executed on computers running Windows.
5131 U-Boot is intended to be simple to build. After installing the
5132 sources you must configure U-Boot for one specific board type. This
5137 where "NAME_defconfig" is the name of one of the existing configu-
5138 rations; see boards.cfg for supported names.
5140 Note: for some board special configuration names may exist; check if
5141 additional information is available from the board vendor; for
5142 instance, the TQM823L systems are available without (standard)
5143 or with LCD support. You can select such additional "features"
5144 when choosing the configuration, i. e.
5146 make TQM823L_defconfig
5147 - will configure for a plain TQM823L, i. e. no LCD support
5149 make TQM823L_LCD_defconfig
5150 - will configure for a TQM823L with U-Boot console on LCD
5155 Finally, type "make all", and you should get some working U-Boot
5156 images ready for download to / installation on your system:
5158 - "u-boot.bin" is a raw binary image
5159 - "u-boot" is an image in ELF binary format
5160 - "u-boot.srec" is in Motorola S-Record format
5162 By default the build is performed locally and the objects are saved
5163 in the source directory. One of the two methods can be used to change
5164 this behavior and build U-Boot to some external directory:
5166 1. Add O= to the make command line invocations:
5168 make O=/tmp/build distclean
5169 make O=/tmp/build NAME_defconfig
5170 make O=/tmp/build all
5172 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5174 export KBUILD_OUTPUT=/tmp/build
5179 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5183 Please be aware that the Makefiles assume you are using GNU make, so
5184 for instance on NetBSD you might need to use "gmake" instead of
5188 If the system board that you have is not listed, then you will need
5189 to port U-Boot to your hardware platform. To do this, follow these
5192 1. Add a new configuration option for your board to the toplevel
5193 "boards.cfg" file, using the existing entries as examples.
5194 Follow the instructions there to keep the boards in order.
5195 2. Create a new directory to hold your board specific code. Add any
5196 files you need. In your board directory, you will need at least
5197 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5198 3. Create a new configuration file "include/configs/<board>.h" for
5200 3. If you're porting U-Boot to a new CPU, then also create a new
5201 directory to hold your CPU specific code. Add any files you need.
5202 4. Run "make <board>_defconfig" with your new name.
5203 5. Type "make", and you should get a working "u-boot.srec" file
5204 to be installed on your target system.
5205 6. Debug and solve any problems that might arise.
5206 [Of course, this last step is much harder than it sounds.]
5209 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5210 ==============================================================
5212 If you have modified U-Boot sources (for instance added a new board
5213 or support for new devices, a new CPU, etc.) you are expected to
5214 provide feedback to the other developers. The feedback normally takes
5215 the form of a "patch", i. e. a context diff against a certain (latest
5216 official or latest in the git repository) version of U-Boot sources.
5218 But before you submit such a patch, please verify that your modifi-
5219 cation did not break existing code. At least make sure that *ALL* of
5220 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5221 just run the "MAKEALL" script, which will configure and build U-Boot
5222 for ALL supported system. Be warned, this will take a while. You can
5223 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5224 environment variable to the script, i. e. to use the ELDK cross tools
5227 CROSS_COMPILE=ppc_8xx- MAKEALL
5229 or to build on a native PowerPC system you can type
5231 CROSS_COMPILE=' ' MAKEALL
5233 When using the MAKEALL script, the default behaviour is to build
5234 U-Boot in the source directory. This location can be changed by
5235 setting the BUILD_DIR environment variable. Also, for each target
5236 built, the MAKEALL script saves two log files (<target>.ERR and
5237 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5238 location can be changed by setting the MAKEALL_LOGDIR environment
5239 variable. For example:
5241 export BUILD_DIR=/tmp/build
5242 export MAKEALL_LOGDIR=/tmp/log
5243 CROSS_COMPILE=ppc_8xx- MAKEALL
5245 With the above settings build objects are saved in the /tmp/build,
5246 log files are saved in the /tmp/log and the source tree remains clean
5247 during the whole build process.
5250 See also "U-Boot Porting Guide" below.
5253 Monitor Commands - Overview:
5254 ============================
5256 go - start application at address 'addr'
5257 run - run commands in an environment variable
5258 bootm - boot application image from memory
5259 bootp - boot image via network using BootP/TFTP protocol
5260 bootz - boot zImage from memory
5261 tftpboot- boot image via network using TFTP protocol
5262 and env variables "ipaddr" and "serverip"
5263 (and eventually "gatewayip")
5264 tftpput - upload a file via network using TFTP protocol
5265 rarpboot- boot image via network using RARP/TFTP protocol
5266 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5267 loads - load S-Record file over serial line
5268 loadb - load binary file over serial line (kermit mode)
5270 mm - memory modify (auto-incrementing)
5271 nm - memory modify (constant address)
5272 mw - memory write (fill)
5274 cmp - memory compare
5275 crc32 - checksum calculation
5276 i2c - I2C sub-system
5277 sspi - SPI utility commands
5278 base - print or set address offset
5279 printenv- print environment variables
5280 setenv - set environment variables
5281 saveenv - save environment variables to persistent storage
5282 protect - enable or disable FLASH write protection
5283 erase - erase FLASH memory
5284 flinfo - print FLASH memory information
5285 nand - NAND memory operations (see doc/README.nand)
5286 bdinfo - print Board Info structure
5287 iminfo - print header information for application image
5288 coninfo - print console devices and informations
5289 ide - IDE sub-system
5290 loop - infinite loop on address range
5291 loopw - infinite write loop on address range
5292 mtest - simple RAM test
5293 icache - enable or disable instruction cache
5294 dcache - enable or disable data cache
5295 reset - Perform RESET of the CPU
5296 echo - echo args to console
5297 version - print monitor version
5298 help - print online help
5299 ? - alias for 'help'
5302 Monitor Commands - Detailed Description:
5303 ========================================
5307 For now: just type "help <command>".
5310 Environment Variables:
5311 ======================
5313 U-Boot supports user configuration using Environment Variables which
5314 can be made persistent by saving to Flash memory.
5316 Environment Variables are set using "setenv", printed using
5317 "printenv", and saved to Flash using "saveenv". Using "setenv"
5318 without a value can be used to delete a variable from the
5319 environment. As long as you don't save the environment you are
5320 working with an in-memory copy. In case the Flash area containing the
5321 environment is erased by accident, a default environment is provided.
5323 Some configuration options can be set using Environment Variables.
5325 List of environment variables (most likely not complete):
5327 baudrate - see CONFIG_BAUDRATE
5329 bootdelay - see CONFIG_BOOTDELAY
5331 bootcmd - see CONFIG_BOOTCOMMAND
5333 bootargs - Boot arguments when booting an RTOS image
5335 bootfile - Name of the image to load with TFTP
5337 bootm_low - Memory range available for image processing in the bootm
5338 command can be restricted. This variable is given as
5339 a hexadecimal number and defines lowest address allowed
5340 for use by the bootm command. See also "bootm_size"
5341 environment variable. Address defined by "bootm_low" is
5342 also the base of the initial memory mapping for the Linux
5343 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5346 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5347 This variable is given as a hexadecimal number and it
5348 defines the size of the memory region starting at base
5349 address bootm_low that is accessible by the Linux kernel
5350 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5351 as the default value if it is defined, and bootm_size is
5354 bootm_size - 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 the size of the region
5357 allowed for use by the bootm command. See also "bootm_low"
5358 environment variable.
5360 updatefile - Location of the software update file on a TFTP server, used
5361 by the automatic software update feature. Please refer to
5362 documentation in doc/README.update for more details.
5364 autoload - if set to "no" (any string beginning with 'n'),
5365 "bootp" will just load perform a lookup of the
5366 configuration from the BOOTP server, but not try to
5367 load any image using TFTP
5369 autostart - if set to "yes", an image loaded using the "bootp",
5370 "rarpboot", "tftpboot" or "diskboot" commands will
5371 be automatically started (by internally calling
5374 If set to "no", a standalone image passed to the
5375 "bootm" command will be copied to the load address
5376 (and eventually uncompressed), but NOT be started.
5377 This can be used to load and uncompress arbitrary
5380 fdt_high - if set this restricts the maximum address that the
5381 flattened device tree will be copied into upon boot.
5382 For example, if you have a system with 1 GB memory
5383 at physical address 0x10000000, while Linux kernel
5384 only recognizes the first 704 MB as low memory, you
5385 may need to set fdt_high as 0x3C000000 to have the
5386 device tree blob be copied to the maximum address
5387 of the 704 MB low memory, so that Linux kernel can
5388 access it during the boot procedure.
5390 If this is set to the special value 0xFFFFFFFF then
5391 the fdt will not be copied at all on boot. For this
5392 to work it must reside in writable memory, have
5393 sufficient padding on the end of it for u-boot to
5394 add the information it needs into it, and the memory
5395 must be accessible by the kernel.
5397 fdtcontroladdr- if set this is the address of the control flattened
5398 device tree used by U-Boot when CONFIG_OF_CONTROL is
5401 i2cfast - (PPC405GP|PPC405EP only)
5402 if set to 'y' configures Linux I2C driver for fast
5403 mode (400kHZ). This environment variable is used in
5404 initialization code. So, for changes to be effective
5405 it must be saved and board must be reset.
5407 initrd_high - restrict positioning of initrd images:
5408 If this variable is not set, initrd images will be
5409 copied to the highest possible address in RAM; this
5410 is usually what you want since it allows for
5411 maximum initrd size. If for some reason you want to
5412 make sure that the initrd image is loaded below the
5413 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5414 variable to a value of "no" or "off" or "0".
5415 Alternatively, you can set it to a maximum upper
5416 address to use (U-Boot will still check that it
5417 does not overwrite the U-Boot stack and data).
5419 For instance, when you have a system with 16 MB
5420 RAM, and want to reserve 4 MB from use by Linux,
5421 you can do this by adding "mem=12M" to the value of
5422 the "bootargs" variable. However, now you must make
5423 sure that the initrd image is placed in the first
5424 12 MB as well - this can be done with
5426 setenv initrd_high 00c00000
5428 If you set initrd_high to 0xFFFFFFFF, this is an
5429 indication to U-Boot that all addresses are legal
5430 for the Linux kernel, including addresses in flash
5431 memory. In this case U-Boot will NOT COPY the
5432 ramdisk at all. This may be useful to reduce the
5433 boot time on your system, but requires that this
5434 feature is supported by your Linux kernel.
5436 ipaddr - IP address; needed for tftpboot command
5438 loadaddr - Default load address for commands like "bootp",
5439 "rarpboot", "tftpboot", "loadb" or "diskboot"
5441 loads_echo - see CONFIG_LOADS_ECHO
5443 serverip - TFTP server IP address; needed for tftpboot command
5445 bootretry - see CONFIG_BOOT_RETRY_TIME
5447 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5449 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5451 ethprime - controls which interface is used first.
5453 ethact - controls which interface is currently active.
5454 For example you can do the following
5456 => setenv ethact FEC
5457 => ping 192.168.0.1 # traffic sent on FEC
5458 => setenv ethact SCC
5459 => ping 10.0.0.1 # traffic sent on SCC
5461 ethrotate - When set to "no" U-Boot does not go through all
5462 available network interfaces.
5463 It just stays at the currently selected interface.
5465 netretry - When set to "no" each network operation will
5466 either succeed or fail without retrying.
5467 When set to "once" the network operation will
5468 fail when all the available network interfaces
5469 are tried once without success.
5470 Useful on scripts which control the retry operation
5473 npe_ucode - set load address for the NPE microcode
5475 silent_linux - If set then Linux will be told to boot silently, by
5476 changing the console to be empty. If "yes" it will be
5477 made silent. If "no" it will not be made silent. If
5478 unset, then it will be made silent if the U-Boot console
5481 tftpsrcport - If this is set, the value is used for TFTP's
5484 tftpdstport - If this is set, the value is used for TFTP's UDP
5485 destination port instead of the Well Know Port 69.
5487 tftpblocksize - Block size to use for TFTP transfers; if not set,
5488 we use the TFTP server's default block size
5490 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5491 seconds, minimum value is 1000 = 1 second). Defines
5492 when a packet is considered to be lost so it has to
5493 be retransmitted. The default is 5000 = 5 seconds.
5494 Lowering this value may make downloads succeed
5495 faster in networks with high packet loss rates or
5496 with unreliable TFTP servers.
5498 vlan - When set to a value < 4095 the traffic over
5499 Ethernet is encapsulated/received over 802.1q
5502 The following image location variables contain the location of images
5503 used in booting. The "Image" column gives the role of the image and is
5504 not an environment variable name. The other columns are environment
5505 variable names. "File Name" gives the name of the file on a TFTP
5506 server, "RAM Address" gives the location in RAM the image will be
5507 loaded to, and "Flash Location" gives the image's address in NOR
5508 flash or offset in NAND flash.
5510 *Note* - these variables don't have to be defined for all boards, some
5511 boards currenlty use other variables for these purposes, and some
5512 boards use these variables for other purposes.
5514 Image File Name RAM Address Flash Location
5515 ----- --------- ----------- --------------
5516 u-boot u-boot u-boot_addr_r u-boot_addr
5517 Linux kernel bootfile kernel_addr_r kernel_addr
5518 device tree blob fdtfile fdt_addr_r fdt_addr
5519 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5521 The following environment variables may be used and automatically
5522 updated by the network boot commands ("bootp" and "rarpboot"),
5523 depending the information provided by your boot server:
5525 bootfile - see above
5526 dnsip - IP address of your Domain Name Server
5527 dnsip2 - IP address of your secondary Domain Name Server
5528 gatewayip - IP address of the Gateway (Router) to use
5529 hostname - Target hostname
5531 netmask - Subnet Mask
5532 rootpath - Pathname of the root filesystem on the NFS server
5533 serverip - see above
5536 There are two special Environment Variables:
5538 serial# - contains hardware identification information such
5539 as type string and/or serial number
5540 ethaddr - Ethernet address
5542 These variables can be set only once (usually during manufacturing of
5543 the board). U-Boot refuses to delete or overwrite these variables
5544 once they have been set once.
5547 Further special Environment Variables:
5549 ver - Contains the U-Boot version string as printed
5550 with the "version" command. This variable is
5551 readonly (see CONFIG_VERSION_VARIABLE).
5554 Please note that changes to some configuration parameters may take
5555 only effect after the next boot (yes, that's just like Windoze :-).
5558 Callback functions for environment variables:
5559 ---------------------------------------------
5561 For some environment variables, the behavior of u-boot needs to change
5562 when their values are changed. This functionality allows functions to
5563 be associated with arbitrary variables. On creation, overwrite, or
5564 deletion, the callback will provide the opportunity for some side
5565 effect to happen or for the change to be rejected.
5567 The callbacks are named and associated with a function using the
5568 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5570 These callbacks are associated with variables in one of two ways. The
5571 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5572 in the board configuration to a string that defines a list of
5573 associations. The list must be in the following format:
5575 entry = variable_name[:callback_name]
5578 If the callback name is not specified, then the callback is deleted.
5579 Spaces are also allowed anywhere in the list.
5581 Callbacks can also be associated by defining the ".callbacks" variable
5582 with the same list format above. Any association in ".callbacks" will
5583 override any association in the static list. You can define
5584 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5585 ".callbacks" environment variable in the default or embedded environment.
5588 Command Line Parsing:
5589 =====================
5591 There are two different command line parsers available with U-Boot:
5592 the old "simple" one, and the much more powerful "hush" shell:
5594 Old, simple command line parser:
5595 --------------------------------
5597 - supports environment variables (through setenv / saveenv commands)
5598 - several commands on one line, separated by ';'
5599 - variable substitution using "... ${name} ..." syntax
5600 - special characters ('$', ';') can be escaped by prefixing with '\',
5602 setenv bootcmd bootm \${address}
5603 - You can also escape text by enclosing in single apostrophes, for example:
5604 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5609 - similar to Bourne shell, with control structures like
5610 if...then...else...fi, for...do...done; while...do...done,
5611 until...do...done, ...
5612 - supports environment ("global") variables (through setenv / saveenv
5613 commands) and local shell variables (through standard shell syntax
5614 "name=value"); only environment variables can be used with "run"
5620 (1) If a command line (or an environment variable executed by a "run"
5621 command) contains several commands separated by semicolon, and
5622 one of these commands fails, then the remaining commands will be
5625 (2) If you execute several variables with one call to run (i. e.
5626 calling run with a list of variables as arguments), any failing
5627 command will cause "run" to terminate, i. e. the remaining
5628 variables are not executed.
5630 Note for Redundant Ethernet Interfaces:
5631 =======================================
5633 Some boards come with redundant Ethernet interfaces; U-Boot supports
5634 such configurations and is capable of automatic selection of a
5635 "working" interface when needed. MAC assignment works as follows:
5637 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5638 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5639 "eth1addr" (=>eth1), "eth2addr", ...
5641 If the network interface stores some valid MAC address (for instance
5642 in SROM), this is used as default address if there is NO correspon-
5643 ding setting in the environment; if the corresponding environment
5644 variable is set, this overrides the settings in the card; that means:
5646 o If the SROM has a valid MAC address, and there is no address in the
5647 environment, the SROM's address is used.
5649 o If there is no valid address in the SROM, and a definition in the
5650 environment exists, then the value from the environment variable is
5653 o If both the SROM and the environment contain a MAC address, and
5654 both addresses are the same, this MAC address is used.
5656 o If both the SROM and the environment contain a MAC address, and the
5657 addresses differ, the value from the environment is used and a
5660 o If neither SROM nor the environment contain a MAC address, an error
5663 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5664 will be programmed into hardware as part of the initialization process. This
5665 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5666 The naming convention is as follows:
5667 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5672 U-Boot is capable of booting (and performing other auxiliary operations on)
5673 images in two formats:
5675 New uImage format (FIT)
5676 -----------------------
5678 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5679 to Flattened Device Tree). It allows the use of images with multiple
5680 components (several kernels, ramdisks, etc.), with contents protected by
5681 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5687 Old image format is based on binary files which can be basically anything,
5688 preceded by a special header; see the definitions in include/image.h for
5689 details; basically, the header defines the following image properties:
5691 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5692 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5693 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5694 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5696 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5697 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5698 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5699 * Compression Type (uncompressed, gzip, bzip2)
5705 The header is marked by a special Magic Number, and both the header
5706 and the data portions of the image are secured against corruption by
5713 Although U-Boot should support any OS or standalone application
5714 easily, the main focus has always been on Linux during the design of
5717 U-Boot includes many features that so far have been part of some
5718 special "boot loader" code within the Linux kernel. Also, any
5719 "initrd" images to be used are no longer part of one big Linux image;
5720 instead, kernel and "initrd" are separate images. This implementation
5721 serves several purposes:
5723 - the same features can be used for other OS or standalone
5724 applications (for instance: using compressed images to reduce the
5725 Flash memory footprint)
5727 - it becomes much easier to port new Linux kernel versions because
5728 lots of low-level, hardware dependent stuff are done by U-Boot
5730 - the same Linux kernel image can now be used with different "initrd"
5731 images; of course this also means that different kernel images can
5732 be run with the same "initrd". This makes testing easier (you don't
5733 have to build a new "zImage.initrd" Linux image when you just
5734 change a file in your "initrd"). Also, a field-upgrade of the
5735 software is easier now.
5741 Porting Linux to U-Boot based systems:
5742 ---------------------------------------
5744 U-Boot cannot save you from doing all the necessary modifications to
5745 configure the Linux device drivers for use with your target hardware
5746 (no, we don't intend to provide a full virtual machine interface to
5749 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5751 Just make sure your machine specific header file (for instance
5752 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5753 Information structure as we define in include/asm-<arch>/u-boot.h,
5754 and make sure that your definition of IMAP_ADDR uses the same value
5755 as your U-Boot configuration in CONFIG_SYS_IMMR.
5757 Note that U-Boot now has a driver model, a unified model for drivers.
5758 If you are adding a new driver, plumb it into driver model. If there
5759 is no uclass available, you are encouraged to create one. See
5763 Configuring the Linux kernel:
5764 -----------------------------
5766 No specific requirements for U-Boot. Make sure you have some root
5767 device (initial ramdisk, NFS) for your target system.
5770 Building a Linux Image:
5771 -----------------------
5773 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5774 not used. If you use recent kernel source, a new build target
5775 "uImage" will exist which automatically builds an image usable by
5776 U-Boot. Most older kernels also have support for a "pImage" target,
5777 which was introduced for our predecessor project PPCBoot and uses a
5778 100% compatible format.
5782 make TQM850L_defconfig
5787 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5788 encapsulate a compressed Linux kernel image with header information,
5789 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5791 * build a standard "vmlinux" kernel image (in ELF binary format):
5793 * convert the kernel into a raw binary image:
5795 ${CROSS_COMPILE}-objcopy -O binary \
5796 -R .note -R .comment \
5797 -S vmlinux linux.bin
5799 * compress the binary image:
5803 * package compressed binary image for U-Boot:
5805 mkimage -A ppc -O linux -T kernel -C gzip \
5806 -a 0 -e 0 -n "Linux Kernel Image" \
5807 -d linux.bin.gz uImage
5810 The "mkimage" tool can also be used to create ramdisk images for use
5811 with U-Boot, either separated from the Linux kernel image, or
5812 combined into one file. "mkimage" encapsulates the images with a 64
5813 byte header containing information about target architecture,
5814 operating system, image type, compression method, entry points, time
5815 stamp, CRC32 checksums, etc.
5817 "mkimage" can be called in two ways: to verify existing images and
5818 print the header information, or to build new images.
5820 In the first form (with "-l" option) mkimage lists the information
5821 contained in the header of an existing U-Boot image; this includes
5822 checksum verification:
5824 tools/mkimage -l image
5825 -l ==> list image header information
5827 The second form (with "-d" option) is used to build a U-Boot image
5828 from a "data file" which is used as image payload:
5830 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5831 -n name -d data_file image
5832 -A ==> set architecture to 'arch'
5833 -O ==> set operating system to 'os'
5834 -T ==> set image type to 'type'
5835 -C ==> set compression type 'comp'
5836 -a ==> set load address to 'addr' (hex)
5837 -e ==> set entry point to 'ep' (hex)
5838 -n ==> set image name to 'name'
5839 -d ==> use image data from 'datafile'
5841 Right now, all Linux kernels for PowerPC systems use the same load
5842 address (0x00000000), but the entry point address depends on the
5845 - 2.2.x kernels have the entry point at 0x0000000C,
5846 - 2.3.x and later kernels have the entry point at 0x00000000.
5848 So a typical call to build a U-Boot image would read:
5850 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5851 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5852 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5853 > examples/uImage.TQM850L
5854 Image Name: 2.4.4 kernel for TQM850L
5855 Created: Wed Jul 19 02:34:59 2000
5856 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5857 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5858 Load Address: 0x00000000
5859 Entry Point: 0x00000000
5861 To verify the contents of the image (or check for corruption):
5863 -> tools/mkimage -l examples/uImage.TQM850L
5864 Image Name: 2.4.4 kernel for TQM850L
5865 Created: Wed Jul 19 02:34:59 2000
5866 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5867 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5868 Load Address: 0x00000000
5869 Entry Point: 0x00000000
5871 NOTE: for embedded systems where boot time is critical you can trade
5872 speed for memory and install an UNCOMPRESSED image instead: this
5873 needs more space in Flash, but boots much faster since it does not
5874 need to be uncompressed:
5876 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5877 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5878 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5879 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5880 > examples/uImage.TQM850L-uncompressed
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 (uncompressed)
5884 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5885 Load Address: 0x00000000
5886 Entry Point: 0x00000000
5889 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5890 when your kernel is intended to use an initial ramdisk:
5892 -> tools/mkimage -n 'Simple Ramdisk Image' \
5893 > -A ppc -O linux -T ramdisk -C gzip \
5894 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5895 Image Name: Simple Ramdisk Image
5896 Created: Wed Jan 12 14:01:50 2000
5897 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5898 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5899 Load Address: 0x00000000
5900 Entry Point: 0x00000000
5902 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5903 option performs the converse operation of the mkimage's second form (the "-d"
5904 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5907 tools/dumpimage -i image -T type -p position data_file
5908 -i ==> extract from the 'image' a specific 'data_file'
5909 -T ==> set image type to 'type'
5910 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5913 Installing a Linux Image:
5914 -------------------------
5916 To downloading a U-Boot image over the serial (console) interface,
5917 you must convert the image to S-Record format:
5919 objcopy -I binary -O srec examples/image examples/image.srec
5921 The 'objcopy' does not understand the information in the U-Boot
5922 image header, so the resulting S-Record file will be relative to
5923 address 0x00000000. To load it to a given address, you need to
5924 specify the target address as 'offset' parameter with the 'loads'
5927 Example: install the image to address 0x40100000 (which on the
5928 TQM8xxL is in the first Flash bank):
5930 => erase 40100000 401FFFFF
5936 ## Ready for S-Record download ...
5937 ~>examples/image.srec
5938 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5940 15989 15990 15991 15992
5941 [file transfer complete]
5943 ## Start Addr = 0x00000000
5946 You can check the success of the download using the 'iminfo' command;
5947 this includes a checksum verification so you can be sure no data
5948 corruption happened:
5952 ## Checking Image at 40100000 ...
5953 Image Name: 2.2.13 for initrd on TQM850L
5954 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5955 Data Size: 335725 Bytes = 327 kB = 0 MB
5956 Load Address: 00000000
5957 Entry Point: 0000000c
5958 Verifying Checksum ... OK
5964 The "bootm" command is used to boot an application that is stored in
5965 memory (RAM or Flash). In case of a Linux kernel image, the contents
5966 of the "bootargs" environment variable is passed to the kernel as
5967 parameters. You can check and modify this variable using the
5968 "printenv" and "setenv" commands:
5971 => printenv bootargs
5972 bootargs=root=/dev/ram
5974 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5976 => printenv bootargs
5977 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5980 ## Booting Linux kernel at 40020000 ...
5981 Image Name: 2.2.13 for NFS on TQM850L
5982 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5983 Data Size: 381681 Bytes = 372 kB = 0 MB
5984 Load Address: 00000000
5985 Entry Point: 0000000c
5986 Verifying Checksum ... OK
5987 Uncompressing Kernel Image ... OK
5988 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
5989 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5990 time_init: decrementer frequency = 187500000/60
5991 Calibrating delay loop... 49.77 BogoMIPS
5992 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5995 If you want to boot a Linux kernel with initial RAM disk, you pass
5996 the memory addresses of both the kernel and the initrd image (PPBCOOT
5997 format!) to the "bootm" command:
5999 => imi 40100000 40200000
6001 ## Checking Image at 40100000 ...
6002 Image Name: 2.2.13 for initrd on TQM850L
6003 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6004 Data Size: 335725 Bytes = 327 kB = 0 MB
6005 Load Address: 00000000
6006 Entry Point: 0000000c
6007 Verifying Checksum ... OK
6009 ## Checking Image at 40200000 ...
6010 Image Name: Simple Ramdisk Image
6011 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6012 Data Size: 566530 Bytes = 553 kB = 0 MB
6013 Load Address: 00000000
6014 Entry Point: 00000000
6015 Verifying Checksum ... OK
6017 => bootm 40100000 40200000
6018 ## Booting Linux kernel 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
6025 Uncompressing Kernel Image ... OK
6026 ## Loading RAMDisk 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
6033 Loading Ramdisk ... OK
6034 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
6035 Boot arguments: root=/dev/ram
6036 time_init: decrementer frequency = 187500000/60
6037 Calibrating delay loop... 49.77 BogoMIPS
6039 RAMDISK: Compressed image found at block 0
6040 VFS: Mounted root (ext2 filesystem).
6044 Boot Linux and pass a flat device tree:
6047 First, U-Boot must be compiled with the appropriate defines. See the section
6048 titled "Linux Kernel Interface" above for a more in depth explanation. The
6049 following is an example of how to start a kernel and pass an updated
6055 oft=oftrees/mpc8540ads.dtb
6056 => tftp $oftaddr $oft
6057 Speed: 1000, full duplex
6059 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6060 Filename 'oftrees/mpc8540ads.dtb'.
6061 Load address: 0x300000
6064 Bytes transferred = 4106 (100a hex)
6065 => tftp $loadaddr $bootfile
6066 Speed: 1000, full duplex
6068 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6070 Load address: 0x200000
6071 Loading:############
6073 Bytes transferred = 1029407 (fb51f hex)
6078 => bootm $loadaddr - $oftaddr
6079 ## Booting image at 00200000 ...
6080 Image Name: Linux-2.6.17-dirty
6081 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6082 Data Size: 1029343 Bytes = 1005.2 kB
6083 Load Address: 00000000
6084 Entry Point: 00000000
6085 Verifying Checksum ... OK
6086 Uncompressing Kernel Image ... OK
6087 Booting using flat device tree at 0x300000
6088 Using MPC85xx ADS machine description
6089 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6093 More About U-Boot Image Types:
6094 ------------------------------
6096 U-Boot supports the following image types:
6098 "Standalone Programs" are directly runnable in the environment
6099 provided by U-Boot; it is expected that (if they behave
6100 well) you can continue to work in U-Boot after return from
6101 the Standalone Program.
6102 "OS Kernel Images" are usually images of some Embedded OS which
6103 will take over control completely. Usually these programs
6104 will install their own set of exception handlers, device
6105 drivers, set up the MMU, etc. - this means, that you cannot
6106 expect to re-enter U-Boot except by resetting the CPU.
6107 "RAMDisk Images" are more or less just data blocks, and their
6108 parameters (address, size) are passed to an OS kernel that is
6110 "Multi-File Images" contain several images, typically an OS
6111 (Linux) kernel image and one or more data images like
6112 RAMDisks. This construct is useful for instance when you want
6113 to boot over the network using BOOTP etc., where the boot
6114 server provides just a single image file, but you want to get
6115 for instance an OS kernel and a RAMDisk image.
6117 "Multi-File Images" start with a list of image sizes, each
6118 image size (in bytes) specified by an "uint32_t" in network
6119 byte order. This list is terminated by an "(uint32_t)0".
6120 Immediately after the terminating 0 follow the images, one by
6121 one, all aligned on "uint32_t" boundaries (size rounded up to
6122 a multiple of 4 bytes).
6124 "Firmware Images" are binary images containing firmware (like
6125 U-Boot or FPGA images) which usually will be programmed to
6128 "Script files" are command sequences that will be executed by
6129 U-Boot's command interpreter; this feature is especially
6130 useful when you configure U-Boot to use a real shell (hush)
6131 as command interpreter.
6133 Booting the Linux zImage:
6134 -------------------------
6136 On some platforms, it's possible to boot Linux zImage. This is done
6137 using the "bootz" command. The syntax of "bootz" command is the same
6138 as the syntax of "bootm" command.
6140 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6141 kernel with raw initrd images. The syntax is slightly different, the
6142 address of the initrd must be augmented by it's size, in the following
6143 format: "<initrd addres>:<initrd size>".
6149 One of the features of U-Boot is that you can dynamically load and
6150 run "standalone" applications, which can use some resources of
6151 U-Boot like console I/O functions or interrupt services.
6153 Two simple examples are included with the sources:
6158 'examples/hello_world.c' contains a small "Hello World" Demo
6159 application; it is automatically compiled when you build U-Boot.
6160 It's configured to run at address 0x00040004, so you can play with it
6164 ## Ready for S-Record download ...
6165 ~>examples/hello_world.srec
6166 1 2 3 4 5 6 7 8 9 10 11 ...
6167 [file transfer complete]
6169 ## Start Addr = 0x00040004
6171 => go 40004 Hello World! This is a test.
6172 ## Starting application at 0x00040004 ...
6183 Hit any key to exit ...
6185 ## Application terminated, rc = 0x0
6187 Another example, which demonstrates how to register a CPM interrupt
6188 handler with the U-Boot code, can be found in 'examples/timer.c'.
6189 Here, a CPM timer is set up to generate an interrupt every second.
6190 The interrupt service routine is trivial, just printing a '.'
6191 character, but this is just a demo program. The application can be
6192 controlled by the following keys:
6194 ? - print current values og the CPM Timer registers
6195 b - enable interrupts and start timer
6196 e - stop timer and disable interrupts
6197 q - quit application
6200 ## Ready for S-Record download ...
6201 ~>examples/timer.srec
6202 1 2 3 4 5 6 7 8 9 10 11 ...
6203 [file transfer complete]
6205 ## Start Addr = 0x00040004
6208 ## Starting application at 0x00040004 ...
6211 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6214 [q, b, e, ?] Set interval 1000000 us
6217 [q, b, e, ?] ........
6218 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6221 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6224 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6227 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6229 [q, b, e, ?] ...Stopping timer
6231 [q, b, e, ?] ## Application terminated, rc = 0x0
6237 Over time, many people have reported problems when trying to use the
6238 "minicom" terminal emulation program for serial download. I (wd)
6239 consider minicom to be broken, and recommend not to use it. Under
6240 Unix, I recommend to use C-Kermit for general purpose use (and
6241 especially for kermit binary protocol download ("loadb" command), and
6242 use "cu" for S-Record download ("loads" command). See
6243 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6244 for help with kermit.
6247 Nevertheless, if you absolutely want to use it try adding this
6248 configuration to your "File transfer protocols" section:
6250 Name Program Name U/D FullScr IO-Red. Multi
6251 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6252 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6258 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6259 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6261 Building requires a cross environment; it is known to work on
6262 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6263 need gmake since the Makefiles are not compatible with BSD make).
6264 Note that the cross-powerpc package does not install include files;
6265 attempting to build U-Boot will fail because <machine/ansi.h> is
6266 missing. This file has to be installed and patched manually:
6268 # cd /usr/pkg/cross/powerpc-netbsd/include
6270 # ln -s powerpc machine
6271 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6272 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6274 Native builds *don't* work due to incompatibilities between native
6275 and U-Boot include files.
6277 Booting assumes that (the first part of) the image booted is a
6278 stage-2 loader which in turn loads and then invokes the kernel
6279 proper. Loader sources will eventually appear in the NetBSD source
6280 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6281 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6284 Implementation Internals:
6285 =========================
6287 The following is not intended to be a complete description of every
6288 implementation detail. However, it should help to understand the
6289 inner workings of U-Boot and make it easier to port it to custom
6293 Initial Stack, Global Data:
6294 ---------------------------
6296 The implementation of U-Boot is complicated by the fact that U-Boot
6297 starts running out of ROM (flash memory), usually without access to
6298 system RAM (because the memory controller is not initialized yet).
6299 This means that we don't have writable Data or BSS segments, and BSS
6300 is not initialized as zero. To be able to get a C environment working
6301 at all, we have to allocate at least a minimal stack. Implementation
6302 options for this are defined and restricted by the CPU used: Some CPU
6303 models provide on-chip memory (like the IMMR area on MPC8xx and
6304 MPC826x processors), on others (parts of) the data cache can be
6305 locked as (mis-) used as memory, etc.
6307 Chris Hallinan posted a good summary of these issues to the
6308 U-Boot mailing list:
6310 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6311 From: "Chris Hallinan" <clh@net1plus.com>
6312 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6315 Correct me if I'm wrong, folks, but the way I understand it
6316 is this: Using DCACHE as initial RAM for Stack, etc, does not
6317 require any physical RAM backing up the cache. The cleverness
6318 is that the cache is being used as a temporary supply of
6319 necessary storage before the SDRAM controller is setup. It's
6320 beyond the scope of this list to explain the details, but you
6321 can see how this works by studying the cache architecture and
6322 operation in the architecture and processor-specific manuals.
6324 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6325 is another option for the system designer to use as an
6326 initial stack/RAM area prior to SDRAM being available. Either
6327 option should work for you. Using CS 4 should be fine if your
6328 board designers haven't used it for something that would
6329 cause you grief during the initial boot! It is frequently not
6332 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6333 with your processor/board/system design. The default value
6334 you will find in any recent u-boot distribution in
6335 walnut.h should work for you. I'd set it to a value larger
6336 than your SDRAM module. If you have a 64MB SDRAM module, set
6337 it above 400_0000. Just make sure your board has no resources
6338 that are supposed to respond to that address! That code in
6339 start.S has been around a while and should work as is when
6340 you get the config right.
6345 It is essential to remember this, since it has some impact on the C
6346 code for the initialization procedures:
6348 * Initialized global data (data segment) is read-only. Do not attempt
6351 * Do not use any uninitialized global data (or implicitly initialized
6352 as zero data - BSS segment) at all - this is undefined, initiali-
6353 zation is performed later (when relocating to RAM).
6355 * Stack space is very limited. Avoid big data buffers or things like
6358 Having only the stack as writable memory limits means we cannot use
6359 normal global data to share information between the code. But it
6360 turned out that the implementation of U-Boot can be greatly
6361 simplified by making a global data structure (gd_t) available to all
6362 functions. We could pass a pointer to this data as argument to _all_
6363 functions, but this would bloat the code. Instead we use a feature of
6364 the GCC compiler (Global Register Variables) to share the data: we
6365 place a pointer (gd) to the global data into a register which we
6366 reserve for this purpose.
6368 When choosing a register for such a purpose we are restricted by the
6369 relevant (E)ABI specifications for the current architecture, and by
6370 GCC's implementation.
6372 For PowerPC, the following registers have specific use:
6374 R2: reserved for system use
6375 R3-R4: parameter passing and return values
6376 R5-R10: parameter passing
6377 R13: small data area pointer
6381 (U-Boot also uses R12 as internal GOT pointer. r12
6382 is a volatile register so r12 needs to be reset when
6383 going back and forth between asm and C)
6385 ==> U-Boot will use R2 to hold a pointer to the global data
6387 Note: on PPC, we could use a static initializer (since the
6388 address of the global data structure is known at compile time),
6389 but it turned out that reserving a register results in somewhat
6390 smaller code - although the code savings are not that big (on
6391 average for all boards 752 bytes for the whole U-Boot image,
6392 624 text + 127 data).
6394 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6395 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6397 ==> U-Boot will use P3 to hold a pointer to the global data
6399 On ARM, the following registers are used:
6401 R0: function argument word/integer result
6402 R1-R3: function argument word
6403 R9: platform specific
6404 R10: stack limit (used only if stack checking is enabled)
6405 R11: argument (frame) pointer
6406 R12: temporary workspace
6409 R15: program counter
6411 ==> U-Boot will use R9 to hold a pointer to the global data
6413 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6415 On Nios II, the ABI is documented here:
6416 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6418 ==> U-Boot will use gp to hold a pointer to the global data
6420 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6421 to access small data sections, so gp is free.
6423 On NDS32, the following registers are used:
6425 R0-R1: argument/return
6427 R15: temporary register for assembler
6428 R16: trampoline register
6429 R28: frame pointer (FP)
6430 R29: global pointer (GP)
6431 R30: link register (LP)
6432 R31: stack pointer (SP)
6433 PC: program counter (PC)
6435 ==> U-Boot will use R10 to hold a pointer to the global data
6437 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6438 or current versions of GCC may "optimize" the code too much.
6443 U-Boot runs in system state and uses physical addresses, i.e. the
6444 MMU is not used either for address mapping nor for memory protection.
6446 The available memory is mapped to fixed addresses using the memory
6447 controller. In this process, a contiguous block is formed for each
6448 memory type (Flash, SDRAM, SRAM), even when it consists of several
6449 physical memory banks.
6451 U-Boot is installed in the first 128 kB of the first Flash bank (on
6452 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6453 booting and sizing and initializing DRAM, the code relocates itself
6454 to the upper end of DRAM. Immediately below the U-Boot code some
6455 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6456 configuration setting]. Below that, a structure with global Board
6457 Info data is placed, followed by the stack (growing downward).
6459 Additionally, some exception handler code is copied to the low 8 kB
6460 of DRAM (0x00000000 ... 0x00001FFF).
6462 So a typical memory configuration with 16 MB of DRAM could look like
6465 0x0000 0000 Exception Vector code
6468 0x0000 2000 Free for Application Use
6474 0x00FB FF20 Monitor Stack (Growing downward)
6475 0x00FB FFAC Board Info Data and permanent copy of global data
6476 0x00FC 0000 Malloc Arena
6479 0x00FE 0000 RAM Copy of Monitor Code
6480 ... eventually: LCD or video framebuffer
6481 ... eventually: pRAM (Protected RAM - unchanged by reset)
6482 0x00FF FFFF [End of RAM]
6485 System Initialization:
6486 ----------------------
6488 In the reset configuration, U-Boot starts at the reset entry point
6489 (on most PowerPC systems at address 0x00000100). Because of the reset
6490 configuration for CS0# this is a mirror of the on board Flash memory.
6491 To be able to re-map memory U-Boot then jumps to its link address.
6492 To be able to implement the initialization code in C, a (small!)
6493 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6494 which provide such a feature like MPC8xx or MPC8260), or in a locked
6495 part of the data cache. After that, U-Boot initializes the CPU core,
6496 the caches and the SIU.
6498 Next, all (potentially) available memory banks are mapped using a
6499 preliminary mapping. For example, we put them on 512 MB boundaries
6500 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6501 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6502 programmed for SDRAM access. Using the temporary configuration, a
6503 simple memory test is run that determines the size of the SDRAM
6506 When there is more than one SDRAM bank, and the banks are of
6507 different size, the largest is mapped first. For equal size, the first
6508 bank (CS2#) is mapped first. The first mapping is always for address
6509 0x00000000, with any additional banks following immediately to create
6510 contiguous memory starting from 0.
6512 Then, the monitor installs itself at the upper end of the SDRAM area
6513 and allocates memory for use by malloc() and for the global Board
6514 Info data; also, the exception vector code is copied to the low RAM
6515 pages, and the final stack is set up.
6517 Only after this relocation will you have a "normal" C environment;
6518 until that you are restricted in several ways, mostly because you are
6519 running from ROM, and because the code will have to be relocated to a
6523 U-Boot Porting Guide:
6524 ----------------------
6526 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6530 int main(int argc, char *argv[])
6532 sighandler_t no_more_time;
6534 signal(SIGALRM, no_more_time);
6535 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6537 if (available_money > available_manpower) {
6538 Pay consultant to port U-Boot;
6542 Download latest U-Boot source;
6544 Subscribe to u-boot mailing list;
6547 email("Hi, I am new to U-Boot, how do I get started?");
6550 Read the README file in the top level directory;
6551 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6552 Read applicable doc/*.README;
6553 Read the source, Luke;
6554 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6557 if (available_money > toLocalCurrency ($2500))
6560 Add a lot of aggravation and time;
6562 if (a similar board exists) { /* hopefully... */
6563 cp -a board/<similar> board/<myboard>
6564 cp include/configs/<similar>.h include/configs/<myboard>.h
6566 Create your own board support subdirectory;
6567 Create your own board include/configs/<myboard>.h file;
6569 Edit new board/<myboard> files
6570 Edit new include/configs/<myboard>.h
6575 Add / modify source code;
6579 email("Hi, I am having problems...");
6581 Send patch file to the U-Boot email list;
6582 if (reasonable critiques)
6583 Incorporate improvements from email list code review;
6585 Defend code as written;
6591 void no_more_time (int sig)
6600 All contributions to U-Boot should conform to the Linux kernel
6601 coding style; see the file "Documentation/CodingStyle" and the script
6602 "scripts/Lindent" in your Linux kernel source directory.
6604 Source files originating from a different project (for example the
6605 MTD subsystem) are generally exempt from these guidelines and are not
6606 reformatted to ease subsequent migration to newer versions of those
6609 Please note that U-Boot is implemented in C (and to some small parts in
6610 Assembler); no C++ is used, so please do not use C++ style comments (//)
6613 Please also stick to the following formatting rules:
6614 - remove any trailing white space
6615 - use TAB characters for indentation and vertical alignment, not spaces
6616 - make sure NOT to use DOS '\r\n' line feeds
6617 - do not add more than 2 consecutive empty lines to source files
6618 - do not add trailing empty lines to source files
6620 Submissions which do not conform to the standards may be returned
6621 with a request to reformat the changes.
6627 Since the number of patches for U-Boot is growing, we need to
6628 establish some rules. Submissions which do not conform to these rules
6629 may be rejected, even when they contain important and valuable stuff.
6631 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6633 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6634 see http://lists.denx.de/mailman/listinfo/u-boot
6636 When you send a patch, please include the following information with
6639 * For bug fixes: a description of the bug and how your patch fixes
6640 this bug. Please try to include a way of demonstrating that the
6641 patch actually fixes something.
6643 * For new features: a description of the feature and your
6646 * A CHANGELOG entry as plaintext (separate from the patch)
6648 * For major contributions, your entry to the CREDITS file
6650 * When you add support for a new board, don't forget to add a
6651 maintainer e-mail address to the boards.cfg file, too.
6653 * If your patch adds new configuration options, don't forget to
6654 document these in the README file.
6656 * The patch itself. If you are using git (which is *strongly*
6657 recommended) you can easily generate the patch using the
6658 "git format-patch". If you then use "git send-email" to send it to
6659 the U-Boot mailing list, you will avoid most of the common problems
6660 with some other mail clients.
6662 If you cannot use git, use "diff -purN OLD NEW". If your version of
6663 diff does not support these options, then get the latest version of
6666 The current directory when running this command shall be the parent
6667 directory of the U-Boot source tree (i. e. please make sure that
6668 your patch includes sufficient directory information for the
6671 We prefer patches as plain text. MIME attachments are discouraged,
6672 and compressed attachments must not be used.
6674 * If one logical set of modifications affects or creates several
6675 files, all these changes shall be submitted in a SINGLE patch file.
6677 * Changesets that contain different, unrelated modifications shall be
6678 submitted as SEPARATE patches, one patch per changeset.
6683 * Before sending the patch, run the MAKEALL script on your patched
6684 source tree and make sure that no errors or warnings are reported
6685 for any of the boards.
6687 * Keep your modifications to the necessary minimum: A patch
6688 containing several unrelated changes or arbitrary reformats will be
6689 returned with a request to re-formatting / split it.
6691 * If you modify existing code, make sure that your new code does not
6692 add to the memory footprint of the code ;-) Small is beautiful!
6693 When adding new features, these should compile conditionally only
6694 (using #ifdef), and the resulting code with the new feature
6695 disabled must not need more memory than the old code without your
6698 * Remember that there is a size limit of 100 kB per message on the
6699 u-boot mailing list. Bigger patches will be moderated. If they are
6700 reasonable and not too big, they will be acknowledged. But patches
6701 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob