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 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc8260 Files specific to Freescale MPC8260 CPUs
190 /mpc85xx Files specific to Freescale MPC85xx CPUs
191 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
192 /lib Architecture specific library files
193 /sh Files generic to SH architecture
194 /cpu CPU specific files
195 /sh2 Files specific to sh2 CPUs
196 /sh3 Files specific to sh3 CPUs
197 /sh4 Files specific to sh4 CPUs
198 /lib Architecture specific library files
199 /sparc Files generic to SPARC architecture
200 /cpu CPU specific files
201 /leon2 Files specific to Gaisler LEON2 SPARC CPU
202 /leon3 Files specific to Gaisler LEON3 SPARC CPU
203 /lib Architecture specific library files
204 /x86 Files generic to x86 architecture
205 /cpu CPU specific files
206 /lib Architecture specific library files
207 /api Machine/arch independent API for external apps
208 /board Board dependent files
209 /common Misc architecture independent functions
210 /disk Code for disk drive partition handling
211 /doc Documentation (don't expect too much)
212 /drivers Commonly used device drivers
213 /dts Contains Makefile for building internal U-Boot fdt.
214 /examples Example code for standalone applications, etc.
215 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
216 /include Header Files
217 /lib Files generic to all architectures
218 /libfdt Library files to support flattened device trees
219 /lzma Library files to support LZMA decompression
220 /lzo Library files to support LZO decompression
222 /post Power On Self Test
223 /spl Secondary Program Loader framework
224 /tools Tools to build S-Record or U-Boot images, etc.
226 Software Configuration:
227 =======================
229 Configuration is usually done using C preprocessor defines; the
230 rationale behind that is to avoid dead code whenever possible.
232 There are two classes of configuration variables:
234 * Configuration _OPTIONS_:
235 These are selectable by the user and have names beginning with
238 * Configuration _SETTINGS_:
239 These depend on the hardware etc. and should not be meddled with if
240 you don't know what you're doing; they have names beginning with
243 Later we will add a configuration tool - probably similar to or even
244 identical to what's used for the Linux kernel. Right now, we have to
245 do the configuration by hand, which means creating some symbolic
246 links and editing some configuration files. We use the TQM8xxL boards
250 Selection of Processor Architecture and Board Type:
251 ---------------------------------------------------
253 For all supported boards there are ready-to-use default
254 configurations available; just type "make <board_name>_defconfig".
256 Example: For a TQM823L module type:
259 make TQM823L_defconfig
261 For the Cogent platform, you need to specify the CPU type as well;
262 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
263 directory according to the instructions in cogent/README.
269 U-Boot can be built natively to run on a Linux host using the 'sandbox'
270 board. This allows feature development which is not board- or architecture-
271 specific to be undertaken on a native platform. The sandbox is also used to
272 run some of U-Boot's tests.
274 See board/sandbox/README.sandbox for more details.
277 Configuration Options:
278 ----------------------
280 Configuration depends on the combination of board and CPU type; all
281 such information is kept in a configuration file
282 "include/configs/<board_name>.h".
284 Example: For a TQM823L module, all configuration settings are in
285 "include/configs/TQM823L.h".
288 Many of the options are named exactly as the corresponding Linux
289 kernel configuration options. The intention is to make it easier to
290 build a config tool - later.
293 The following options need to be configured:
295 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
297 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
299 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
300 Define exactly one, e.g. CONFIG_ATSTK1002
302 - CPU Module Type: (if CONFIG_COGENT is defined)
303 Define exactly one of
305 --- FIXME --- not tested yet:
306 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
307 CONFIG_CMA287_23, CONFIG_CMA287_50
309 - Motherboard Type: (if CONFIG_COGENT is defined)
310 Define exactly one of
311 CONFIG_CMA101, CONFIG_CMA102
313 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
314 Define one or more of
317 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
318 Define one or more of
319 CONFIG_LCD_HEARTBEAT - update a character position on
320 the LCD display every second with
323 - Marvell Family Member
324 CONFIG_SYS_MVFS - define it if you want to enable
325 multiple fs option at one time
326 for marvell soc family
328 - 8xx CPU Options: (if using an MPC8xx CPU)
329 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
330 get_gclk_freq() cannot work
331 e.g. if there is no 32KHz
332 reference PIT/RTC clock
333 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
336 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
337 CONFIG_SYS_8xx_CPUCLK_MIN
338 CONFIG_SYS_8xx_CPUCLK_MAX
339 CONFIG_8xx_CPUCLK_DEFAULT
340 See doc/README.MPC866
342 CONFIG_SYS_MEASURE_CPUCLK
344 Define this to measure the actual CPU clock instead
345 of relying on the correctness of the configured
346 values. Mostly useful for board bringup to make sure
347 the PLL is locked at the intended frequency. Note
348 that this requires a (stable) reference clock (32 kHz
349 RTC clock or CONFIG_SYS_8XX_XIN)
351 CONFIG_SYS_DELAYED_ICACHE
353 Define this option if you want to enable the
354 ICache only when Code runs from RAM.
359 Specifies that the core is a 64-bit PowerPC implementation (implements
360 the "64" category of the Power ISA). This is necessary for ePAPR
361 compliance, among other possible reasons.
363 CONFIG_SYS_FSL_TBCLK_DIV
365 Defines the core time base clock divider ratio compared to the
366 system clock. On most PQ3 devices this is 8, on newer QorIQ
367 devices it can be 16 or 32. The ratio varies from SoC to Soc.
369 CONFIG_SYS_FSL_PCIE_COMPAT
371 Defines the string to utilize when trying to match PCIe device
372 tree nodes for the given platform.
374 CONFIG_SYS_PPC_E500_DEBUG_TLB
376 Enables a temporary TLB entry to be used during boot to work
377 around limitations in e500v1 and e500v2 external debugger
378 support. This reduces the portions of the boot code where
379 breakpoints and single stepping do not work. The value of this
380 symbol should be set to the TLB1 entry to be used for this
383 CONFIG_SYS_FSL_ERRATUM_A004510
385 Enables a workaround for erratum A004510. If set,
386 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
390 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
392 Defines one or two SoC revisions (low 8 bits of SVR)
393 for which the A004510 workaround should be applied.
395 The rest of SVR is either not relevant to the decision
396 of whether the erratum is present (e.g. p2040 versus
397 p2041) or is implied by the build target, which controls
398 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
400 See Freescale App Note 4493 for more information about
403 CONFIG_A003399_NOR_WORKAROUND
404 Enables a workaround for IFC erratum A003399. It is only
405 required during NOR boot.
407 CONFIG_A008044_WORKAROUND
408 Enables a workaround for T1040/T1042 erratum A008044. It is only
409 required during NAND boot and valid for Rev 1.0 SoC revision
411 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
413 This is the value to write into CCSR offset 0x18600
414 according to the A004510 workaround.
416 CONFIG_SYS_FSL_DSP_DDR_ADDR
417 This value denotes start offset of DDR memory which is
418 connected exclusively to the DSP cores.
420 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
421 This value denotes start offset of M2 memory
422 which is directly connected to the DSP core.
424 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
425 This value denotes start offset of M3 memory which is directly
426 connected to the DSP core.
428 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
429 This value denotes start offset of DSP CCSR space.
431 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
432 Single Source Clock is clocking mode present in some of FSL SoC's.
433 In this mode, a single differential clock is used to supply
434 clocks to the sysclock, ddrclock and usbclock.
436 CONFIG_SYS_CPC_REINIT_F
437 This CONFIG is defined when the CPC is configured as SRAM at the
438 time of U-boot entry and is required to be re-initialized.
441 Indicates this SoC supports deep sleep feature. If deep sleep is
442 supported, core will start to execute uboot when wakes up.
444 - Generic CPU options:
445 CONFIG_SYS_GENERIC_GLOBAL_DATA
446 Defines global data is initialized in generic board board_init_f().
447 If this macro is defined, global data is created and cleared in
448 generic board board_init_f(). Without this macro, architecture/board
449 should initialize global data before calling board_init_f().
451 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
453 Defines the endianess of the CPU. Implementation of those
454 values is arch specific.
457 Freescale DDR driver in use. This type of DDR controller is
458 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
461 CONFIG_SYS_FSL_DDR_ADDR
462 Freescale DDR memory-mapped register base.
464 CONFIG_SYS_FSL_DDR_EMU
465 Specify emulator support for DDR. Some DDR features such as
466 deskew training are not available.
468 CONFIG_SYS_FSL_DDRC_GEN1
469 Freescale DDR1 controller.
471 CONFIG_SYS_FSL_DDRC_GEN2
472 Freescale DDR2 controller.
474 CONFIG_SYS_FSL_DDRC_GEN3
475 Freescale DDR3 controller.
477 CONFIG_SYS_FSL_DDRC_GEN4
478 Freescale DDR4 controller.
480 CONFIG_SYS_FSL_DDRC_ARM_GEN3
481 Freescale DDR3 controller for ARM-based SoCs.
484 Board config to use DDR1. It can be enabled for SoCs with
485 Freescale DDR1 or DDR2 controllers, depending on the board
489 Board config to use DDR2. It can be eanbeld for SoCs with
490 Freescale DDR2 or DDR3 controllers, depending on the board
494 Board config to use DDR3. It can be enabled for SoCs with
495 Freescale DDR3 or DDR3L controllers.
498 Board config to use DDR3L. It can be enabled for SoCs with
502 Board config to use DDR4. It can be enabled for SoCs with
505 CONFIG_SYS_FSL_IFC_BE
506 Defines the IFC controller register space as Big Endian
508 CONFIG_SYS_FSL_IFC_LE
509 Defines the IFC controller register space as Little Endian
511 CONFIG_SYS_FSL_PBL_PBI
512 It enables addition of RCW (Power on reset configuration) in built image.
513 Please refer doc/README.pblimage for more details
515 CONFIG_SYS_FSL_PBL_RCW
516 It adds PBI(pre-boot instructions) commands in u-boot build image.
517 PBI commands can be used to configure SoC before it starts the execution.
518 Please refer doc/README.pblimage for more details
521 It adds a target to create boot binary having SPL binary in PBI format
522 concatenated with u-boot binary.
524 CONFIG_SYS_FSL_DDR_BE
525 Defines the DDR controller register space as Big Endian
527 CONFIG_SYS_FSL_DDR_LE
528 Defines the DDR controller register space as Little Endian
530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
531 Physical address from the view of DDR controllers. It is the
532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
533 it could be different for ARM SoCs.
535 CONFIG_SYS_FSL_DDR_INTLV_256B
536 DDR controller interleaving on 256-byte. This is a special
537 interleaving mode, handled by Dickens for Freescale layerscape
540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
541 Number of controllers used as main memory.
543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
544 Number of controllers used for other than main memory.
546 CONFIG_SYS_FSL_SEC_BE
547 Defines the SEC controller register space as Big Endian
549 CONFIG_SYS_FSL_SEC_LE
550 Defines the SEC controller register space as Little Endian
552 - Intel Monahans options:
553 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
555 Defines the Monahans run mode to oscillator
556 ratio. Valid values are 8, 16, 24, 31. The core
557 frequency is this value multiplied by 13 MHz.
559 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
561 Defines the Monahans turbo mode to oscillator
562 ratio. Valid values are 1 (default if undefined) and
563 2. The core frequency as calculated above is multiplied
567 CONFIG_SYS_INIT_SP_OFFSET
569 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
570 pointer. This is needed for the temporary stack before
573 CONFIG_SYS_MIPS_CACHE_MODE
575 Cache operation mode for the MIPS CPU.
576 See also arch/mips/include/asm/mipsregs.h.
578 CONF_CM_CACHABLE_NO_WA
581 CONF_CM_CACHABLE_NONCOHERENT
585 CONF_CM_CACHABLE_ACCELERATED
587 CONFIG_SYS_XWAY_EBU_BOOTCFG
589 Special option for Lantiq XWAY SoCs for booting from NOR flash.
590 See also arch/mips/cpu/mips32/start.S.
592 CONFIG_XWAY_SWAP_BYTES
594 Enable compilation of tools/xway-swap-bytes needed for Lantiq
595 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
596 be swapped if a flash programmer is used.
599 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
601 Select high exception vectors of the ARM core, e.g., do not
602 clear the V bit of the c1 register of CP15.
604 CONFIG_SYS_THUMB_BUILD
606 Use this flag to build U-Boot using the Thumb instruction
607 set for ARM architectures. Thumb instruction set provides
608 better code density. For ARM architectures that support
609 Thumb2 this flag will result in Thumb2 code generated by
612 CONFIG_ARM_ERRATA_716044
613 CONFIG_ARM_ERRATA_742230
614 CONFIG_ARM_ERRATA_743622
615 CONFIG_ARM_ERRATA_751472
616 CONFIG_ARM_ERRATA_794072
617 CONFIG_ARM_ERRATA_761320
619 If set, the workarounds for these ARM errata are applied early
620 during U-Boot startup. Note that these options force the
621 workarounds to be applied; no CPU-type/version detection
622 exists, unlike the similar options in the Linux kernel. Do not
623 set these options unless they apply!
626 Driver model is a new framework for devices in U-Boot
627 introduced in early 2014. U-Boot is being progressively
628 moved over to this. It offers a consistent device structure,
629 supports grouping devices into classes and has built-in
630 handling of platform data and device tree.
632 To enable transition to driver model in a relatively
633 painful fashion, each subsystem can be independently
634 switched between the legacy/ad-hoc approach and the new
635 driver model using the options below. Also, many uclass
636 interfaces include compatibility features which may be
637 removed once the conversion of that subsystem is complete.
638 As a result, the API provided by the subsystem may in fact
639 not change with driver model.
641 See doc/driver-model/README.txt for more information.
645 Enable driver model. This brings in the core support,
646 including scanning of platform data on start-up. If
647 CONFIG_OF_CONTROL is enabled, the device tree will be
648 scanned also when available.
652 Enable driver model test commands. These allow you to print
653 out the driver model tree and the uclasses.
657 Enable some demo devices and the 'demo' command. These are
658 really only useful for playing around while trying to
659 understand driver model in sandbox.
663 Enable driver model in SPL. You will need to provide a
664 suitable malloc() implementation. If you are not using the
665 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
666 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
667 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
668 In most cases driver model will only allocate a few uclasses
669 and devices in SPL, so 1KB should be enable. See
670 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
675 Enable driver model for serial. This replaces
676 drivers/serial/serial.c with the serial uclass, which
677 implements serial_putc() etc. The uclass interface is
678 defined in include/serial.h.
682 Enable driver model for GPIO access. The standard GPIO
683 interface (gpio_get_value(), etc.) is then implemented by
684 the GPIO uclass. Drivers provide methods to query the
685 particular GPIOs that they provide. The uclass interface
686 is defined in include/asm-generic/gpio.h.
690 Enable driver model for SPI. The SPI slave interface
691 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
692 the SPI uclass. Drivers provide methods to access the SPI
693 buses that they control. The uclass interface is defined in
694 include/spi.h. The existing spi_slave structure is attached
695 as 'parent data' to every slave on each bus. Slaves
696 typically use driver-private data instead of extending the
701 Enable driver model for SPI flash. This SPI flash interface
702 (spi_flash_probe(), spi_flash_write(), etc.) is then
703 implemented by the SPI flash uclass. There is one standard
704 SPI flash driver which knows how to probe most chips
705 supported by U-Boot. The uclass interface is defined in
706 include/spi_flash.h, but is currently fully compatible
707 with the old interface to avoid confusion and duplication
708 during the transition parent. SPI and SPI flash must be
709 enabled together (it is not possible to use driver model
710 for one and not the other).
714 Enable driver model for the Chrome OS EC interface. This
715 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
716 but otherwise makes few changes. Since cros_ec also supports
717 I2C and LPC (which don't support driver model yet), a full
718 conversion is not yet possible.
721 ** Code size options: The following options are enabled by
722 default except in SPL. Enable them explicitly to get these
727 Enable the dm_warn() function. This can use up quite a bit
728 of space for its strings.
732 Enable registering a serial device with the stdio library.
734 CONFIG_DM_DEVICE_REMOVE
736 Enable removing of devices.
739 - Linux Kernel Interface:
742 U-Boot stores all clock information in Hz
743 internally. For binary compatibility with older Linux
744 kernels (which expect the clocks passed in the
745 bd_info data to be in MHz) the environment variable
746 "clocks_in_mhz" can be defined so that U-Boot
747 converts clock data to MHZ before passing it to the
749 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
750 "clocks_in_mhz=1" is automatically included in the
753 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
755 When transferring memsize parameter to Linux, some versions
756 expect it to be in bytes, others in MB.
757 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
761 New kernel versions are expecting firmware settings to be
762 passed using flattened device trees (based on open firmware
766 * New libfdt-based support
767 * Adds the "fdt" command
768 * The bootm command automatically updates the fdt
770 OF_CPU - The proper name of the cpus node (only required for
771 MPC512X and MPC5xxx based boards).
772 OF_SOC - The proper name of the soc node (only required for
773 MPC512X and MPC5xxx based boards).
774 OF_TBCLK - The timebase frequency.
775 OF_STDOUT_PATH - The path to the console device
777 boards with QUICC Engines require OF_QE to set UCC MAC
780 CONFIG_OF_BOARD_SETUP
782 Board code has addition modification that it wants to make
783 to the flat device tree before handing it off to the kernel
785 CONFIG_OF_SYSTEM_SETUP
787 Other code has addition modification that it wants to make
788 to the flat device tree before handing it off to the kernel.
789 This causes ft_system_setup() to be called before booting
794 This define fills in the correct boot CPU in the boot
795 param header, the default value is zero if undefined.
799 U-Boot can detect if an IDE device is present or not.
800 If not, and this new config option is activated, U-Boot
801 removes the ATA node from the DTS before booting Linux,
802 so the Linux IDE driver does not probe the device and
803 crash. This is needed for buggy hardware (uc101) where
804 no pull down resistor is connected to the signal IDE5V_DD7.
806 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
808 This setting is mandatory for all boards that have only one
809 machine type and must be used to specify the machine type
810 number as it appears in the ARM machine registry
811 (see http://www.arm.linux.org.uk/developer/machines/).
812 Only boards that have multiple machine types supported
813 in a single configuration file and the machine type is
814 runtime discoverable, do not have to use this setting.
816 - vxWorks boot parameters:
818 bootvx constructs a valid bootline using the following
819 environments variables: bootfile, ipaddr, serverip, hostname.
820 It loads the vxWorks image pointed bootfile.
822 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
823 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
824 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
825 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
827 CONFIG_SYS_VXWORKS_ADD_PARAMS
829 Add it at the end of the bootline. E.g "u=username pw=secret"
831 Note: If a "bootargs" environment is defined, it will overwride
832 the defaults discussed just above.
834 - Cache Configuration:
835 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
836 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
837 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
839 - Cache Configuration for ARM:
840 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
842 CONFIG_SYS_PL310_BASE - Physical base address of PL310
843 controller register space
848 Define this if you want support for Amba PrimeCell PL010 UARTs.
852 Define this if you want support for Amba PrimeCell PL011 UARTs.
856 If you have Amba PrimeCell PL011 UARTs, set this variable to
857 the clock speed of the UARTs.
861 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
862 define this to a list of base addresses for each (supported)
863 port. See e.g. include/configs/versatile.h
865 CONFIG_PL011_SERIAL_RLCR
867 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
868 have separate receive and transmit line control registers. Set
869 this variable to initialize the extra register.
871 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
873 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
874 boot loader that has already initialized the UART. Define this
875 variable to flush the UART at init time.
877 CONFIG_SERIAL_HW_FLOW_CONTROL
879 Define this variable to enable hw flow control in serial driver.
880 Current user of this option is drivers/serial/nsl16550.c driver
883 Depending on board, define exactly one serial port
884 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
885 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
886 console by defining CONFIG_8xx_CONS_NONE
888 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
889 port routines must be defined elsewhere
890 (i.e. serial_init(), serial_getc(), ...)
893 Enables console device for a color framebuffer. Needs following
894 defines (cf. smiLynxEM, i8042)
895 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
897 VIDEO_HW_RECTFILL graphic chip supports
900 VIDEO_HW_BITBLT graphic chip supports
901 bit-blit (cf. smiLynxEM)
902 VIDEO_VISIBLE_COLS visible pixel columns
904 VIDEO_VISIBLE_ROWS visible pixel rows
905 VIDEO_PIXEL_SIZE bytes per pixel
906 VIDEO_DATA_FORMAT graphic data format
907 (0-5, cf. cfb_console.c)
908 VIDEO_FB_ADRS framebuffer address
909 VIDEO_KBD_INIT_FCT keyboard int fct
910 (i.e. i8042_kbd_init())
911 VIDEO_TSTC_FCT test char fct
913 VIDEO_GETC_FCT get char fct
915 CONFIG_CONSOLE_CURSOR cursor drawing on/off
916 (requires blink timer
918 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
919 CONFIG_CONSOLE_TIME display time/date info in
921 (requires CONFIG_CMD_DATE)
922 CONFIG_VIDEO_LOGO display Linux logo in
924 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
925 linux_logo.h for logo.
926 Requires CONFIG_VIDEO_LOGO
927 CONFIG_CONSOLE_EXTRA_INFO
928 additional board info beside
931 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
932 a limited number of ANSI escape sequences (cursor control,
933 erase functions and limited graphics rendition control).
935 When CONFIG_CFB_CONSOLE is defined, video console is
936 default i/o. Serial console can be forced with
937 environment 'console=serial'.
939 When CONFIG_SILENT_CONSOLE is defined, all console
940 messages (by U-Boot and Linux!) can be silenced with
941 the "silent" environment variable. See
942 doc/README.silent for more information.
944 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
946 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
950 CONFIG_BAUDRATE - in bps
951 Select one of the baudrates listed in
952 CONFIG_SYS_BAUDRATE_TABLE, see below.
953 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
955 - Console Rx buffer length
956 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
957 the maximum receive buffer length for the SMC.
958 This option is actual only for 82xx and 8xx possible.
959 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
960 must be defined, to setup the maximum idle timeout for
963 - Pre-Console Buffer:
964 Prior to the console being initialised (i.e. serial UART
965 initialised etc) all console output is silently discarded.
966 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
967 buffer any console messages prior to the console being
968 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
969 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
970 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
971 bytes are output before the console is initialised, the
972 earlier bytes are discarded.
974 'Sane' compilers will generate smaller code if
975 CONFIG_PRE_CON_BUF_SZ is a power of 2
977 - Safe printf() functions
978 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
979 the printf() functions. These are defined in
980 include/vsprintf.h and include snprintf(), vsnprintf() and
981 so on. Code size increase is approximately 300-500 bytes.
982 If this option is not given then these functions will
983 silently discard their buffer size argument - this means
984 you are not getting any overflow checking in this case.
986 - Boot Delay: CONFIG_BOOTDELAY - in seconds
987 Delay before automatically booting the default image;
988 set to -1 to disable autoboot.
989 set to -2 to autoboot with no delay and not check for abort
990 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
992 See doc/README.autoboot for these options that
993 work with CONFIG_BOOTDELAY. None are required.
994 CONFIG_BOOT_RETRY_TIME
995 CONFIG_BOOT_RETRY_MIN
996 CONFIG_AUTOBOOT_KEYED
997 CONFIG_AUTOBOOT_PROMPT
998 CONFIG_AUTOBOOT_DELAY_STR
999 CONFIG_AUTOBOOT_STOP_STR
1000 CONFIG_AUTOBOOT_DELAY_STR2
1001 CONFIG_AUTOBOOT_STOP_STR2
1002 CONFIG_ZERO_BOOTDELAY_CHECK
1003 CONFIG_RESET_TO_RETRY
1007 Only needed when CONFIG_BOOTDELAY is enabled;
1008 define a command string that is automatically executed
1009 when no character is read on the console interface
1010 within "Boot Delay" after reset.
1013 This can be used to pass arguments to the bootm
1014 command. The value of CONFIG_BOOTARGS goes into the
1015 environment value "bootargs".
1017 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1018 The value of these goes into the environment as
1019 "ramboot" and "nfsboot" respectively, and can be used
1020 as a convenience, when switching between booting from
1024 CONFIG_BOOTCOUNT_LIMIT
1025 Implements a mechanism for detecting a repeating reboot
1027 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1029 CONFIG_BOOTCOUNT_ENV
1030 If no softreset save registers are found on the hardware
1031 "bootcount" is stored in the environment. To prevent a
1032 saveenv on all reboots, the environment variable
1033 "upgrade_available" is used. If "upgrade_available" is
1034 0, "bootcount" is always 0, if "upgrade_available" is
1035 1 "bootcount" is incremented in the environment.
1036 So the Userspace Applikation must set the "upgrade_available"
1037 and "bootcount" variable to 0, if a boot was successfully.
1039 - Pre-Boot Commands:
1042 When this option is #defined, the existence of the
1043 environment variable "preboot" will be checked
1044 immediately before starting the CONFIG_BOOTDELAY
1045 countdown and/or running the auto-boot command resp.
1046 entering interactive mode.
1048 This feature is especially useful when "preboot" is
1049 automatically generated or modified. For an example
1050 see the LWMON board specific code: here "preboot" is
1051 modified when the user holds down a certain
1052 combination of keys on the (special) keyboard when
1055 - Serial Download Echo Mode:
1057 If defined to 1, all characters received during a
1058 serial download (using the "loads" command) are
1059 echoed back. This might be needed by some terminal
1060 emulations (like "cu"), but may as well just take
1061 time on others. This setting #define's the initial
1062 value of the "loads_echo" environment variable.
1064 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1065 CONFIG_KGDB_BAUDRATE
1066 Select one of the baudrates listed in
1067 CONFIG_SYS_BAUDRATE_TABLE, see below.
1069 - Monitor Functions:
1070 Monitor commands can be included or excluded
1071 from the build by using the #include files
1072 <config_cmd_all.h> and #undef'ing unwanted
1073 commands, or using <config_cmd_default.h>
1074 and augmenting with additional #define's
1075 for wanted commands.
1077 The default command configuration includes all commands
1078 except those marked below with a "*".
1080 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1081 CONFIG_CMD_ASKENV * ask for env variable
1082 CONFIG_CMD_BDI bdinfo
1083 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1084 CONFIG_CMD_BMP * BMP support
1085 CONFIG_CMD_BSP * Board specific commands
1086 CONFIG_CMD_BOOTD bootd
1087 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1088 CONFIG_CMD_CACHE * icache, dcache
1089 CONFIG_CMD_CLK * clock command support
1090 CONFIG_CMD_CONSOLE coninfo
1091 CONFIG_CMD_CRC32 * crc32
1092 CONFIG_CMD_DATE * support for RTC, date/time...
1093 CONFIG_CMD_DHCP * DHCP support
1094 CONFIG_CMD_DIAG * Diagnostics
1095 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1096 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1097 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1098 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1099 CONFIG_CMD_DTT * Digital Therm and Thermostat
1100 CONFIG_CMD_ECHO echo arguments
1101 CONFIG_CMD_EDITENV edit env variable
1102 CONFIG_CMD_EEPROM * EEPROM read/write support
1103 CONFIG_CMD_ELF * bootelf, bootvx
1104 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1105 CONFIG_CMD_ENV_FLAGS * display details about env flags
1106 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1107 CONFIG_CMD_EXPORTENV * export the environment
1108 CONFIG_CMD_EXT2 * ext2 command support
1109 CONFIG_CMD_EXT4 * ext4 command support
1110 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1111 that work for multiple fs types
1112 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1113 CONFIG_CMD_SAVEENV saveenv
1114 CONFIG_CMD_FDC * Floppy Disk Support
1115 CONFIG_CMD_FAT * FAT command support
1116 CONFIG_CMD_FLASH flinfo, erase, protect
1117 CONFIG_CMD_FPGA FPGA device initialization support
1118 CONFIG_CMD_FUSE * Device fuse support
1119 CONFIG_CMD_GETTIME * Get time since boot
1120 CONFIG_CMD_GO * the 'go' command (exec code)
1121 CONFIG_CMD_GREPENV * search environment
1122 CONFIG_CMD_HASH * calculate hash / digest
1123 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1124 CONFIG_CMD_I2C * I2C serial bus support
1125 CONFIG_CMD_IDE * IDE harddisk support
1126 CONFIG_CMD_IMI iminfo
1127 CONFIG_CMD_IMLS List all images found in NOR flash
1128 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1129 CONFIG_CMD_IMMAP * IMMR dump support
1130 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1131 CONFIG_CMD_IMPORTENV * import an environment
1132 CONFIG_CMD_INI * import data from an ini file into the env
1133 CONFIG_CMD_IRQ * irqinfo
1134 CONFIG_CMD_ITEST Integer/string test of 2 values
1135 CONFIG_CMD_JFFS2 * JFFS2 Support
1136 CONFIG_CMD_KGDB * kgdb
1137 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1138 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1140 CONFIG_CMD_LOADB loadb
1141 CONFIG_CMD_LOADS loads
1142 CONFIG_CMD_MD5SUM * print md5 message digest
1143 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1144 CONFIG_CMD_MEMINFO * Display detailed memory information
1145 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1147 CONFIG_CMD_MEMTEST * mtest
1148 CONFIG_CMD_MISC Misc functions like sleep etc
1149 CONFIG_CMD_MMC * MMC memory mapped support
1150 CONFIG_CMD_MII * MII utility commands
1151 CONFIG_CMD_MTDPARTS * MTD partition support
1152 CONFIG_CMD_NAND * NAND support
1153 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1154 CONFIG_CMD_NFS NFS support
1155 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1156 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1157 CONFIG_CMD_PCI * pciinfo
1158 CONFIG_CMD_PCMCIA * PCMCIA support
1159 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1161 CONFIG_CMD_PORTIO * Port I/O
1162 CONFIG_CMD_READ * Read raw data from partition
1163 CONFIG_CMD_REGINFO * Register dump
1164 CONFIG_CMD_RUN run command in env variable
1165 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1166 CONFIG_CMD_SAVES * save S record dump
1167 CONFIG_CMD_SCSI * SCSI Support
1168 CONFIG_CMD_SDRAM * print SDRAM configuration information
1169 (requires CONFIG_CMD_I2C)
1170 CONFIG_CMD_SETGETDCR Support for DCR Register access
1172 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1173 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1174 (requires CONFIG_CMD_MEMORY)
1175 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1176 CONFIG_CMD_SOURCE "source" command Support
1177 CONFIG_CMD_SPI * SPI serial bus support
1178 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1179 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1180 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1181 CONFIG_CMD_TIMER * access to the system tick timer
1182 CONFIG_CMD_USB * USB support
1183 CONFIG_CMD_CDP * Cisco Discover Protocol support
1184 CONFIG_CMD_MFSL * Microblaze FSL support
1185 CONFIG_CMD_XIMG Load part of Multi Image
1186 CONFIG_CMD_UUID * Generate random UUID or GUID string
1188 EXAMPLE: If you want all functions except of network
1189 support you can write:
1191 #include "config_cmd_all.h"
1192 #undef CONFIG_CMD_NET
1195 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1197 Note: Don't enable the "icache" and "dcache" commands
1198 (configuration option CONFIG_CMD_CACHE) unless you know
1199 what you (and your U-Boot users) are doing. Data
1200 cache cannot be enabled on systems like the 8xx or
1201 8260 (where accesses to the IMMR region must be
1202 uncached), and it cannot be disabled on all other
1203 systems where we (mis-) use the data cache to hold an
1204 initial stack and some data.
1207 XXX - this list needs to get updated!
1209 - Regular expression support:
1211 If this variable is defined, U-Boot is linked against
1212 the SLRE (Super Light Regular Expression) library,
1213 which adds regex support to some commands, as for
1214 example "env grep" and "setexpr".
1218 If this variable is defined, U-Boot will use a device tree
1219 to configure its devices, instead of relying on statically
1220 compiled #defines in the board file. This option is
1221 experimental and only available on a few boards. The device
1222 tree is available in the global data as gd->fdt_blob.
1224 U-Boot needs to get its device tree from somewhere. This can
1225 be done using one of the two options below:
1228 If this variable is defined, U-Boot will embed a device tree
1229 binary in its image. This device tree file should be in the
1230 board directory and called <soc>-<board>.dts. The binary file
1231 is then picked up in board_init_f() and made available through
1232 the global data structure as gd->blob.
1235 If this variable is defined, U-Boot will build a device tree
1236 binary. It will be called u-boot.dtb. Architecture-specific
1237 code will locate it at run-time. Generally this works by:
1239 cat u-boot.bin u-boot.dtb >image.bin
1241 and in fact, U-Boot does this for you, creating a file called
1242 u-boot-dtb.bin which is useful in the common case. You can
1243 still use the individual files if you need something more
1248 If this variable is defined, it enables watchdog
1249 support for the SoC. There must be support in the SoC
1250 specific code for a watchdog. For the 8xx and 8260
1251 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1252 register. When supported for a specific SoC is
1253 available, then no further board specific code should
1254 be needed to use it.
1257 When using a watchdog circuitry external to the used
1258 SoC, then define this variable and provide board
1259 specific code for the "hw_watchdog_reset" function.
1262 CONFIG_VERSION_VARIABLE
1263 If this variable is defined, an environment variable
1264 named "ver" is created by U-Boot showing the U-Boot
1265 version as printed by the "version" command.
1266 Any change to this variable will be reverted at the
1271 When CONFIG_CMD_DATE is selected, the type of the RTC
1272 has to be selected, too. Define exactly one of the
1275 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1276 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1277 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1278 CONFIG_RTC_MC146818 - use MC146818 RTC
1279 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1280 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1281 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1282 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1283 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1284 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1285 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1286 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1287 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1290 Note that if the RTC uses I2C, then the I2C interface
1291 must also be configured. See I2C Support, below.
1294 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1296 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1297 chip-ngpio pairs that tell the PCA953X driver the number of
1298 pins supported by a particular chip.
1300 Note that if the GPIO device uses I2C, then the I2C interface
1301 must also be configured. See I2C Support, below.
1304 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1305 accesses and can checksum them or write a list of them out
1306 to memory. See the 'iotrace' command for details. This is
1307 useful for testing device drivers since it can confirm that
1308 the driver behaves the same way before and after a code
1309 change. Currently this is supported on sandbox and arm. To
1310 add support for your architecture, add '#include <iotrace.h>'
1311 to the bottom of arch/<arch>/include/asm/io.h and test.
1313 Example output from the 'iotrace stats' command is below.
1314 Note that if the trace buffer is exhausted, the checksum will
1315 still continue to operate.
1318 Start: 10000000 (buffer start address)
1319 Size: 00010000 (buffer size)
1320 Offset: 00000120 (current buffer offset)
1321 Output: 10000120 (start + offset)
1322 Count: 00000018 (number of trace records)
1323 CRC32: 9526fb66 (CRC32 of all trace records)
1325 - Timestamp Support:
1327 When CONFIG_TIMESTAMP is selected, the timestamp
1328 (date and time) of an image is printed by image
1329 commands like bootm or iminfo. This option is
1330 automatically enabled when you select CONFIG_CMD_DATE .
1332 - Partition Labels (disklabels) Supported:
1333 Zero or more of the following:
1334 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1335 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1336 Intel architecture, USB sticks, etc.
1337 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1338 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1339 bootloader. Note 2TB partition limit; see
1341 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1343 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1344 CONFIG_CMD_SCSI) you must configure support for at
1345 least one non-MTD partition type as well.
1348 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1349 board configurations files but used nowhere!
1351 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1352 be performed by calling the function
1353 ide_set_reset(int reset)
1354 which has to be defined in a board specific file
1359 Set this to enable ATAPI support.
1364 Set this to enable support for disks larger than 137GB
1365 Also look at CONFIG_SYS_64BIT_LBA.
1366 Whithout these , LBA48 support uses 32bit variables and will 'only'
1367 support disks up to 2.1TB.
1369 CONFIG_SYS_64BIT_LBA:
1370 When enabled, makes the IDE subsystem use 64bit sector addresses.
1374 At the moment only there is only support for the
1375 SYM53C8XX SCSI controller; define
1376 CONFIG_SCSI_SYM53C8XX to enable it.
1378 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1379 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1380 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1381 maximum numbers of LUNs, SCSI ID's and target
1383 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1385 The environment variable 'scsidevs' is set to the number of
1386 SCSI devices found during the last scan.
1388 - NETWORK Support (PCI):
1390 Support for Intel 8254x/8257x gigabit chips.
1393 Utility code for direct access to the SPI bus on Intel 8257x.
1394 This does not do anything useful unless you set at least one
1395 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1397 CONFIG_E1000_SPI_GENERIC
1398 Allow generic access to the SPI bus on the Intel 8257x, for
1399 example with the "sspi" command.
1402 Management command for E1000 devices. When used on devices
1403 with SPI support you can reprogram the EEPROM from U-Boot.
1405 CONFIG_E1000_FALLBACK_MAC
1406 default MAC for empty EEPROM after production.
1409 Support for Intel 82557/82559/82559ER chips.
1410 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1411 write routine for first time initialisation.
1414 Support for Digital 2114x chips.
1415 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1416 modem chip initialisation (KS8761/QS6611).
1419 Support for National dp83815 chips.
1422 Support for National dp8382[01] gigabit chips.
1424 - NETWORK Support (other):
1426 CONFIG_DRIVER_AT91EMAC
1427 Support for AT91RM9200 EMAC.
1430 Define this to use reduced MII inteface
1432 CONFIG_DRIVER_AT91EMAC_QUIET
1433 If this defined, the driver is quiet.
1434 The driver doen't show link status messages.
1436 CONFIG_CALXEDA_XGMAC
1437 Support for the Calxeda XGMAC device
1440 Support for SMSC's LAN91C96 chips.
1442 CONFIG_LAN91C96_BASE
1443 Define this to hold the physical address
1444 of the LAN91C96's I/O space
1446 CONFIG_LAN91C96_USE_32_BIT
1447 Define this to enable 32 bit addressing
1450 Support for SMSC's LAN91C111 chip
1452 CONFIG_SMC91111_BASE
1453 Define this to hold the physical address
1454 of the device (I/O space)
1456 CONFIG_SMC_USE_32_BIT
1457 Define this if data bus is 32 bits
1459 CONFIG_SMC_USE_IOFUNCS
1460 Define this to use i/o functions instead of macros
1461 (some hardware wont work with macros)
1463 CONFIG_DRIVER_TI_EMAC
1464 Support for davinci emac
1466 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1467 Define this if you have more then 3 PHYs.
1470 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1472 CONFIG_FTGMAC100_EGIGA
1473 Define this to use GE link update with gigabit PHY.
1474 Define this if FTGMAC100 is connected to gigabit PHY.
1475 If your system has 10/100 PHY only, it might not occur
1476 wrong behavior. Because PHY usually return timeout or
1477 useless data when polling gigabit status and gigabit
1478 control registers. This behavior won't affect the
1479 correctnessof 10/100 link speed update.
1482 Support for SMSC's LAN911x and LAN921x chips
1485 Define this to hold the physical address
1486 of the device (I/O space)
1488 CONFIG_SMC911X_32_BIT
1489 Define this if data bus is 32 bits
1491 CONFIG_SMC911X_16_BIT
1492 Define this if data bus is 16 bits. If your processor
1493 automatically converts one 32 bit word to two 16 bit
1494 words you may also try CONFIG_SMC911X_32_BIT.
1497 Support for Renesas on-chip Ethernet controller
1499 CONFIG_SH_ETHER_USE_PORT
1500 Define the number of ports to be used
1502 CONFIG_SH_ETHER_PHY_ADDR
1503 Define the ETH PHY's address
1505 CONFIG_SH_ETHER_CACHE_WRITEBACK
1506 If this option is set, the driver enables cache flush.
1510 Support for PWM modul on the imx6.
1514 Support TPM devices.
1517 Support for i2c bus TPM devices. Only one device
1518 per system is supported at this time.
1520 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1521 Define the the i2c bus number for the TPM device
1523 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1524 Define the TPM's address on the i2c bus
1526 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1527 Define the burst count bytes upper limit
1529 CONFIG_TPM_ATMEL_TWI
1530 Support for Atmel TWI TPM device. Requires I2C support.
1533 Support for generic parallel port TPM devices. Only one device
1534 per system is supported at this time.
1536 CONFIG_TPM_TIS_BASE_ADDRESS
1537 Base address where the generic TPM device is mapped
1538 to. Contemporary x86 systems usually map it at
1542 Add tpm monitor functions.
1543 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1544 provides monitor access to authorized functions.
1547 Define this to enable the TPM support library which provides
1548 functional interfaces to some TPM commands.
1549 Requires support for a TPM device.
1551 CONFIG_TPM_AUTH_SESSIONS
1552 Define this to enable authorized functions in the TPM library.
1553 Requires CONFIG_TPM and CONFIG_SHA1.
1556 At the moment only the UHCI host controller is
1557 supported (PIP405, MIP405, MPC5200); define
1558 CONFIG_USB_UHCI to enable it.
1559 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1560 and define CONFIG_USB_STORAGE to enable the USB
1563 Supported are USB Keyboards and USB Floppy drives
1565 MPC5200 USB requires additional defines:
1567 for 528 MHz Clock: 0x0001bbbb
1571 for differential drivers: 0x00001000
1572 for single ended drivers: 0x00005000
1573 for differential drivers on PSC3: 0x00000100
1574 for single ended drivers on PSC3: 0x00004100
1575 CONFIG_SYS_USB_EVENT_POLL
1576 May be defined to allow interrupt polling
1577 instead of using asynchronous interrupts
1579 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1580 txfilltuning field in the EHCI controller on reset.
1582 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1583 HW module registers.
1586 Define the below if you wish to use the USB console.
1587 Once firmware is rebuilt from a serial console issue the
1588 command "setenv stdin usbtty; setenv stdout usbtty" and
1589 attach your USB cable. The Unix command "dmesg" should print
1590 it has found a new device. The environment variable usbtty
1591 can be set to gserial or cdc_acm to enable your device to
1592 appear to a USB host as a Linux gserial device or a
1593 Common Device Class Abstract Control Model serial device.
1594 If you select usbtty = gserial you should be able to enumerate
1596 # modprobe usbserial vendor=0xVendorID product=0xProductID
1597 else if using cdc_acm, simply setting the environment
1598 variable usbtty to be cdc_acm should suffice. The following
1599 might be defined in YourBoardName.h
1602 Define this to build a UDC device
1605 Define this to have a tty type of device available to
1606 talk to the UDC device
1609 Define this to enable the high speed support for usb
1610 device and usbtty. If this feature is enabled, a routine
1611 int is_usbd_high_speed(void)
1612 also needs to be defined by the driver to dynamically poll
1613 whether the enumeration has succeded at high speed or full
1616 CONFIG_SYS_CONSOLE_IS_IN_ENV
1617 Define this if you want stdin, stdout &/or stderr to
1621 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1622 Derive USB clock from external clock "blah"
1623 - CONFIG_SYS_USB_EXTC_CLK 0x02
1625 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1626 Derive USB clock from brgclk
1627 - CONFIG_SYS_USB_BRG_CLK 0x04
1629 If you have a USB-IF assigned VendorID then you may wish to
1630 define your own vendor specific values either in BoardName.h
1631 or directly in usbd_vendor_info.h. If you don't define
1632 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1633 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1634 should pretend to be a Linux device to it's target host.
1636 CONFIG_USBD_MANUFACTURER
1637 Define this string as the name of your company for
1638 - CONFIG_USBD_MANUFACTURER "my company"
1640 CONFIG_USBD_PRODUCT_NAME
1641 Define this string as the name of your product
1642 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1644 CONFIG_USBD_VENDORID
1645 Define this as your assigned Vendor ID from the USB
1646 Implementors Forum. This *must* be a genuine Vendor ID
1647 to avoid polluting the USB namespace.
1648 - CONFIG_USBD_VENDORID 0xFFFF
1650 CONFIG_USBD_PRODUCTID
1651 Define this as the unique Product ID
1653 - CONFIG_USBD_PRODUCTID 0xFFFF
1655 - ULPI Layer Support:
1656 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1657 the generic ULPI layer. The generic layer accesses the ULPI PHY
1658 via the platform viewport, so you need both the genric layer and
1659 the viewport enabled. Currently only Chipidea/ARC based
1660 viewport is supported.
1661 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1662 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1663 If your ULPI phy needs a different reference clock than the
1664 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1665 the appropriate value in Hz.
1668 The MMC controller on the Intel PXA is supported. To
1669 enable this define CONFIG_MMC. The MMC can be
1670 accessed from the boot prompt by mapping the device
1671 to physical memory similar to flash. Command line is
1672 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1673 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1676 Support for Renesas on-chip MMCIF controller
1678 CONFIG_SH_MMCIF_ADDR
1679 Define the base address of MMCIF registers
1682 Define the clock frequency for MMCIF
1685 Enable the generic MMC driver
1687 CONFIG_SUPPORT_EMMC_BOOT
1688 Enable some additional features of the eMMC boot partitions.
1690 CONFIG_SUPPORT_EMMC_RPMB
1691 Enable the commands for reading, writing and programming the
1692 key for the Replay Protection Memory Block partition in eMMC.
1694 - USB Device Firmware Update (DFU) class support:
1696 This enables the USB portion of the DFU USB class
1699 This enables the command "dfu" which is used to have
1700 U-Boot create a DFU class device via USB. This command
1701 requires that the "dfu_alt_info" environment variable be
1702 set and define the alt settings to expose to the host.
1705 This enables support for exposing (e)MMC devices via DFU.
1708 This enables support for exposing NAND devices via DFU.
1711 This enables support for exposing RAM via DFU.
1712 Note: DFU spec refer to non-volatile memory usage, but
1713 allow usages beyond the scope of spec - here RAM usage,
1714 one that would help mostly the developer.
1716 CONFIG_SYS_DFU_DATA_BUF_SIZE
1717 Dfu transfer uses a buffer before writing data to the
1718 raw storage device. Make the size (in bytes) of this buffer
1719 configurable. The size of this buffer is also configurable
1720 through the "dfu_bufsiz" environment variable.
1722 CONFIG_SYS_DFU_MAX_FILE_SIZE
1723 When updating files rather than the raw storage device,
1724 we use a static buffer to copy the file into and then write
1725 the buffer once we've been given the whole file. Define
1726 this to the maximum filesize (in bytes) for the buffer.
1727 Default is 4 MiB if undefined.
1729 DFU_DEFAULT_POLL_TIMEOUT
1730 Poll timeout [ms], is the timeout a device can send to the
1731 host. The host must wait for this timeout before sending
1732 a subsequent DFU_GET_STATUS request to the device.
1734 DFU_MANIFEST_POLL_TIMEOUT
1735 Poll timeout [ms], which the device sends to the host when
1736 entering dfuMANIFEST state. Host waits this timeout, before
1737 sending again an USB request to the device.
1739 - USB Device Android Fastboot support:
1741 This enables the command "fastboot" which enables the Android
1742 fastboot mode for the platform's USB device. Fastboot is a USB
1743 protocol for downloading images, flashing and device control
1744 used on Android devices.
1745 See doc/README.android-fastboot for more information.
1747 CONFIG_ANDROID_BOOT_IMAGE
1748 This enables support for booting images which use the Android
1749 image format header.
1751 CONFIG_USB_FASTBOOT_BUF_ADDR
1752 The fastboot protocol requires a large memory buffer for
1753 downloads. Define this to the starting RAM address to use for
1756 CONFIG_USB_FASTBOOT_BUF_SIZE
1757 The fastboot protocol requires a large memory buffer for
1758 downloads. This buffer should be as large as possible for a
1759 platform. Define this to the size available RAM for fastboot.
1761 CONFIG_FASTBOOT_FLASH
1762 The fastboot protocol includes a "flash" command for writing
1763 the downloaded image to a non-volatile storage device. Define
1764 this to enable the "fastboot flash" command.
1766 CONFIG_FASTBOOT_FLASH_MMC_DEV
1767 The fastboot "flash" command requires additional information
1768 regarding the non-volatile storage device. Define this to
1769 the eMMC device that fastboot should use to store the image.
1771 CONFIG_FASTBOOT_GPT_NAME
1772 The fastboot "flash" command supports writing the downloaded
1773 image to the Protective MBR and the Primary GUID Partition
1774 Table. (Additionally, this downloaded image is post-processed
1775 to generate and write the Backup GUID Partition Table.)
1776 This occurs when the specified "partition name" on the
1777 "fastboot flash" command line matches this value.
1778 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1780 - Journaling Flash filesystem support:
1781 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1782 CONFIG_JFFS2_NAND_DEV
1783 Define these for a default partition on a NAND device
1785 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1786 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1787 Define these for a default partition on a NOR device
1789 CONFIG_SYS_JFFS_CUSTOM_PART
1790 Define this to create an own partition. You have to provide a
1791 function struct part_info* jffs2_part_info(int part_num)
1793 If you define only one JFFS2 partition you may also want to
1794 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1795 to disable the command chpart. This is the default when you
1796 have not defined a custom partition
1798 - FAT(File Allocation Table) filesystem write function support:
1801 Define this to enable support for saving memory data as a
1802 file in FAT formatted partition.
1804 This will also enable the command "fatwrite" enabling the
1805 user to write files to FAT.
1807 CBFS (Coreboot Filesystem) support
1810 Define this to enable support for reading from a Coreboot
1811 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1814 - FAT(File Allocation Table) filesystem cluster size:
1815 CONFIG_FS_FAT_MAX_CLUSTSIZE
1817 Define the max cluster size for fat operations else
1818 a default value of 65536 will be defined.
1823 Define this to enable standard (PC-Style) keyboard
1827 Standard PC keyboard driver with US (is default) and
1828 GERMAN key layout (switch via environment 'keymap=de') support.
1829 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1830 for cfb_console. Supports cursor blinking.
1833 Enables a Chrome OS keyboard using the CROS_EC interface.
1834 This uses CROS_EC to communicate with a second microcontroller
1835 which provides key scans on request.
1840 Define this to enable video support (for output to
1843 CONFIG_VIDEO_CT69000
1845 Enable Chips & Technologies 69000 Video chip
1847 CONFIG_VIDEO_SMI_LYNXEM
1848 Enable Silicon Motion SMI 712/710/810 Video chip. The
1849 video output is selected via environment 'videoout'
1850 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1853 For the CT69000 and SMI_LYNXEM drivers, videomode is
1854 selected via environment 'videomode'. Two different ways
1856 - "videomode=num" 'num' is a standard LiLo mode numbers.
1857 Following standard modes are supported (* is default):
1859 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1860 -------------+---------------------------------------------
1861 8 bits | 0x301* 0x303 0x305 0x161 0x307
1862 15 bits | 0x310 0x313 0x316 0x162 0x319
1863 16 bits | 0x311 0x314 0x317 0x163 0x31A
1864 24 bits | 0x312 0x315 0x318 ? 0x31B
1865 -------------+---------------------------------------------
1866 (i.e. setenv videomode 317; saveenv; reset;)
1868 - "videomode=bootargs" all the video parameters are parsed
1869 from the bootargs. (See drivers/video/videomodes.c)
1872 CONFIG_VIDEO_SED13806
1873 Enable Epson SED13806 driver. This driver supports 8bpp
1874 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1875 or CONFIG_VIDEO_SED13806_16BPP
1878 Enable the Freescale DIU video driver. Reference boards for
1879 SOCs that have a DIU should define this macro to enable DIU
1880 support, and should also define these other macros:
1886 CONFIG_VIDEO_SW_CURSOR
1887 CONFIG_VGA_AS_SINGLE_DEVICE
1889 CONFIG_VIDEO_BMP_LOGO
1891 The DIU driver will look for the 'video-mode' environment
1892 variable, and if defined, enable the DIU as a console during
1893 boot. See the documentation file README.video for a
1894 description of this variable.
1898 Enable the VGA video / BIOS for x86. The alternative if you
1899 are using coreboot is to use the coreboot frame buffer
1906 Define this to enable a custom keyboard support.
1907 This simply calls drv_keyboard_init() which must be
1908 defined in your board-specific files.
1909 The only board using this so far is RBC823.
1911 - LCD Support: CONFIG_LCD
1913 Define this to enable LCD support (for output to LCD
1914 display); also select one of the supported displays
1915 by defining one of these:
1919 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1921 CONFIG_NEC_NL6448AC33:
1923 NEC NL6448AC33-18. Active, color, single scan.
1925 CONFIG_NEC_NL6448BC20
1927 NEC NL6448BC20-08. 6.5", 640x480.
1928 Active, color, single scan.
1930 CONFIG_NEC_NL6448BC33_54
1932 NEC NL6448BC33-54. 10.4", 640x480.
1933 Active, color, single scan.
1937 Sharp 320x240. Active, color, single scan.
1938 It isn't 16x9, and I am not sure what it is.
1940 CONFIG_SHARP_LQ64D341
1942 Sharp LQ64D341 display, 640x480.
1943 Active, color, single scan.
1947 HLD1045 display, 640x480.
1948 Active, color, single scan.
1952 Optrex CBL50840-2 NF-FW 99 22 M5
1954 Hitachi LMG6912RPFC-00T
1958 320x240. Black & white.
1960 Normally display is black on white background; define
1961 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1963 CONFIG_LCD_ALIGNMENT
1965 Normally the LCD is page-aligned (typically 4KB). If this is
1966 defined then the LCD will be aligned to this value instead.
1967 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1968 here, since it is cheaper to change data cache settings on
1969 a per-section basis.
1971 CONFIG_CONSOLE_SCROLL_LINES
1973 When the console need to be scrolled, this is the number of
1974 lines to scroll by. It defaults to 1. Increasing this makes
1975 the console jump but can help speed up operation when scrolling
1980 Support drawing of RLE8-compressed bitmaps on the LCD.
1984 Enables an 'i2c edid' command which can read EDID
1985 information over I2C from an attached LCD display.
1987 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1989 If this option is set, the environment is checked for
1990 a variable "splashimage". If found, the usual display
1991 of logo, copyright and system information on the LCD
1992 is suppressed and the BMP image at the address
1993 specified in "splashimage" is loaded instead. The
1994 console is redirected to the "nulldev", too. This
1995 allows for a "silent" boot where a splash screen is
1996 loaded very quickly after power-on.
1998 CONFIG_SPLASHIMAGE_GUARD
2000 If this option is set, then U-Boot will prevent the environment
2001 variable "splashimage" from being set to a problematic address
2002 (see README.displaying-bmps).
2003 This option is useful for targets where, due to alignment
2004 restrictions, an improperly aligned BMP image will cause a data
2005 abort. If you think you will not have problems with unaligned
2006 accesses (for example because your toolchain prevents them)
2007 there is no need to set this option.
2009 CONFIG_SPLASH_SCREEN_ALIGN
2011 If this option is set the splash image can be freely positioned
2012 on the screen. Environment variable "splashpos" specifies the
2013 position as "x,y". If a positive number is given it is used as
2014 number of pixel from left/top. If a negative number is given it
2015 is used as number of pixel from right/bottom. You can also
2016 specify 'm' for centering the image.
2019 setenv splashpos m,m
2020 => image at center of screen
2022 setenv splashpos 30,20
2023 => image at x = 30 and y = 20
2025 setenv splashpos -10,m
2026 => vertically centered image
2027 at x = dspWidth - bmpWidth - 9
2029 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2031 If this option is set, additionally to standard BMP
2032 images, gzipped BMP images can be displayed via the
2033 splashscreen support or the bmp command.
2035 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2037 If this option is set, 8-bit RLE compressed BMP images
2038 can be displayed via the splashscreen support or the
2041 - Do compressing for memory range:
2044 If this option is set, it would use zlib deflate method
2045 to compress the specified memory at its best effort.
2047 - Compression support:
2050 Enabled by default to support gzip compressed images.
2054 If this option is set, support for bzip2 compressed
2055 images is included. If not, only uncompressed and gzip
2056 compressed images are supported.
2058 NOTE: the bzip2 algorithm requires a lot of RAM, so
2059 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2064 If this option is set, support for lzma compressed
2067 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2068 requires an amount of dynamic memory that is given by the
2071 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2073 Where lc and lp stand for, respectively, Literal context bits
2074 and Literal pos bits.
2076 This value is upper-bounded by 14MB in the worst case. Anyway,
2077 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2078 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2079 a very small buffer.
2081 Use the lzmainfo tool to determinate the lc and lp values and
2082 then calculate the amount of needed dynamic memory (ensuring
2083 the appropriate CONFIG_SYS_MALLOC_LEN value).
2087 If this option is set, support for LZO compressed images
2093 The address of PHY on MII bus.
2095 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2097 The clock frequency of the MII bus
2101 If this option is set, support for speed/duplex
2102 detection of gigabit PHY is included.
2104 CONFIG_PHY_RESET_DELAY
2106 Some PHY like Intel LXT971A need extra delay after
2107 reset before any MII register access is possible.
2108 For such PHY, set this option to the usec delay
2109 required. (minimum 300usec for LXT971A)
2111 CONFIG_PHY_CMD_DELAY (ppc4xx)
2113 Some PHY like Intel LXT971A need extra delay after
2114 command issued before MII status register can be read
2124 Define a default value for Ethernet address to use
2125 for the respective Ethernet interface, in case this
2126 is not determined automatically.
2131 Define a default value for the IP address to use for
2132 the default Ethernet interface, in case this is not
2133 determined through e.g. bootp.
2134 (Environment variable "ipaddr")
2136 - Server IP address:
2139 Defines a default value for the IP address of a TFTP
2140 server to contact when using the "tftboot" command.
2141 (Environment variable "serverip")
2143 CONFIG_KEEP_SERVERADDR
2145 Keeps the server's MAC address, in the env 'serveraddr'
2146 for passing to bootargs (like Linux's netconsole option)
2148 - Gateway IP address:
2151 Defines a default value for the IP address of the
2152 default router where packets to other networks are
2154 (Environment variable "gatewayip")
2159 Defines a default value for the subnet mask (or
2160 routing prefix) which is used to determine if an IP
2161 address belongs to the local subnet or needs to be
2162 forwarded through a router.
2163 (Environment variable "netmask")
2165 - Multicast TFTP Mode:
2168 Defines whether you want to support multicast TFTP as per
2169 rfc-2090; for example to work with atftp. Lets lots of targets
2170 tftp down the same boot image concurrently. Note: the Ethernet
2171 driver in use must provide a function: mcast() to join/leave a
2174 - BOOTP Recovery Mode:
2175 CONFIG_BOOTP_RANDOM_DELAY
2177 If you have many targets in a network that try to
2178 boot using BOOTP, you may want to avoid that all
2179 systems send out BOOTP requests at precisely the same
2180 moment (which would happen for instance at recovery
2181 from a power failure, when all systems will try to
2182 boot, thus flooding the BOOTP server. Defining
2183 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2184 inserted before sending out BOOTP requests. The
2185 following delays are inserted then:
2187 1st BOOTP request: delay 0 ... 1 sec
2188 2nd BOOTP request: delay 0 ... 2 sec
2189 3rd BOOTP request: delay 0 ... 4 sec
2191 BOOTP requests: delay 0 ... 8 sec
2193 CONFIG_BOOTP_ID_CACHE_SIZE
2195 BOOTP packets are uniquely identified using a 32-bit ID. The
2196 server will copy the ID from client requests to responses and
2197 U-Boot will use this to determine if it is the destination of
2198 an incoming response. Some servers will check that addresses
2199 aren't in use before handing them out (usually using an ARP
2200 ping) and therefore take up to a few hundred milliseconds to
2201 respond. Network congestion may also influence the time it
2202 takes for a response to make it back to the client. If that
2203 time is too long, U-Boot will retransmit requests. In order
2204 to allow earlier responses to still be accepted after these
2205 retransmissions, U-Boot's BOOTP client keeps a small cache of
2206 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2207 cache. The default is to keep IDs for up to four outstanding
2208 requests. Increasing this will allow U-Boot to accept offers
2209 from a BOOTP client in networks with unusually high latency.
2211 - BOOTP Random transaction ID:
2212 CONFIG_BOOTP_RANDOM_ID
2214 The standard algorithm to generate a DHCP/BOOTP transaction ID
2215 by using the MAC address and the current time stamp may not
2216 quite unlikely produce duplicate transaction IDs from different
2217 clients in the same network. This option creates a transaction
2218 ID using the rand() function. Provided that the RNG has been
2219 seeded well, this should guarantee unique transaction IDs
2222 - DHCP Advanced Options:
2223 You can fine tune the DHCP functionality by defining
2224 CONFIG_BOOTP_* symbols:
2226 CONFIG_BOOTP_SUBNETMASK
2227 CONFIG_BOOTP_GATEWAY
2228 CONFIG_BOOTP_HOSTNAME
2229 CONFIG_BOOTP_NISDOMAIN
2230 CONFIG_BOOTP_BOOTPATH
2231 CONFIG_BOOTP_BOOTFILESIZE
2234 CONFIG_BOOTP_SEND_HOSTNAME
2235 CONFIG_BOOTP_NTPSERVER
2236 CONFIG_BOOTP_TIMEOFFSET
2237 CONFIG_BOOTP_VENDOREX
2238 CONFIG_BOOTP_MAY_FAIL
2240 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2241 environment variable, not the BOOTP server.
2243 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2244 after the configured retry count, the call will fail
2245 instead of starting over. This can be used to fail over
2246 to Link-local IP address configuration if the DHCP server
2249 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2250 serverip from a DHCP server, it is possible that more
2251 than one DNS serverip is offered to the client.
2252 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2253 serverip will be stored in the additional environment
2254 variable "dnsip2". The first DNS serverip is always
2255 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2258 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2259 to do a dynamic update of a DNS server. To do this, they
2260 need the hostname of the DHCP requester.
2261 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2262 of the "hostname" environment variable is passed as
2263 option 12 to the DHCP server.
2265 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2267 A 32bit value in microseconds for a delay between
2268 receiving a "DHCP Offer" and sending the "DHCP Request".
2269 This fixes a problem with certain DHCP servers that don't
2270 respond 100% of the time to a "DHCP request". E.g. On an
2271 AT91RM9200 processor running at 180MHz, this delay needed
2272 to be *at least* 15,000 usec before a Windows Server 2003
2273 DHCP server would reply 100% of the time. I recommend at
2274 least 50,000 usec to be safe. The alternative is to hope
2275 that one of the retries will be successful but note that
2276 the DHCP timeout and retry process takes a longer than
2279 - Link-local IP address negotiation:
2280 Negotiate with other link-local clients on the local network
2281 for an address that doesn't require explicit configuration.
2282 This is especially useful if a DHCP server cannot be guaranteed
2283 to exist in all environments that the device must operate.
2285 See doc/README.link-local for more information.
2288 CONFIG_CDP_DEVICE_ID
2290 The device id used in CDP trigger frames.
2292 CONFIG_CDP_DEVICE_ID_PREFIX
2294 A two character string which is prefixed to the MAC address
2299 A printf format string which contains the ascii name of
2300 the port. Normally is set to "eth%d" which sets
2301 eth0 for the first Ethernet, eth1 for the second etc.
2303 CONFIG_CDP_CAPABILITIES
2305 A 32bit integer which indicates the device capabilities;
2306 0x00000010 for a normal host which does not forwards.
2310 An ascii string containing the version of the software.
2314 An ascii string containing the name of the platform.
2318 A 32bit integer sent on the trigger.
2320 CONFIG_CDP_POWER_CONSUMPTION
2322 A 16bit integer containing the power consumption of the
2323 device in .1 of milliwatts.
2325 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2327 A byte containing the id of the VLAN.
2329 - Status LED: CONFIG_STATUS_LED
2331 Several configurations allow to display the current
2332 status using a LED. For instance, the LED will blink
2333 fast while running U-Boot code, stop blinking as
2334 soon as a reply to a BOOTP request was received, and
2335 start blinking slow once the Linux kernel is running
2336 (supported by a status LED driver in the Linux
2337 kernel). Defining CONFIG_STATUS_LED enables this
2343 The status LED can be connected to a GPIO pin.
2344 In such cases, the gpio_led driver can be used as a
2345 status LED backend implementation. Define CONFIG_GPIO_LED
2346 to include the gpio_led driver in the U-Boot binary.
2348 CONFIG_GPIO_LED_INVERTED_TABLE
2349 Some GPIO connected LEDs may have inverted polarity in which
2350 case the GPIO high value corresponds to LED off state and
2351 GPIO low value corresponds to LED on state.
2352 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2353 with a list of GPIO LEDs that have inverted polarity.
2355 - CAN Support: CONFIG_CAN_DRIVER
2357 Defining CONFIG_CAN_DRIVER enables CAN driver support
2358 on those systems that support this (optional)
2359 feature, like the TQM8xxL modules.
2361 - I2C Support: CONFIG_SYS_I2C
2363 This enable the NEW i2c subsystem, and will allow you to use
2364 i2c commands at the u-boot command line (as long as you set
2365 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2366 based realtime clock chips or other i2c devices. See
2367 common/cmd_i2c.c for a description of the command line
2370 ported i2c driver to the new framework:
2371 - drivers/i2c/soft_i2c.c:
2372 - activate first bus with CONFIG_SYS_I2C_SOFT define
2373 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2374 for defining speed and slave address
2375 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2376 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2377 for defining speed and slave address
2378 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2379 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2380 for defining speed and slave address
2381 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2382 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2383 for defining speed and slave address
2385 - drivers/i2c/fsl_i2c.c:
2386 - activate i2c driver with CONFIG_SYS_I2C_FSL
2387 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2388 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2389 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2391 - If your board supports a second fsl i2c bus, define
2392 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2393 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2394 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2397 - drivers/i2c/tegra_i2c.c:
2398 - activate this driver with CONFIG_SYS_I2C_TEGRA
2399 - This driver adds 4 i2c buses with a fix speed from
2400 100000 and the slave addr 0!
2402 - drivers/i2c/ppc4xx_i2c.c
2403 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2404 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2405 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2407 - drivers/i2c/i2c_mxc.c
2408 - activate this driver with CONFIG_SYS_I2C_MXC
2409 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2410 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2411 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2412 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2413 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2414 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2415 If those defines are not set, default value is 100000
2416 for speed, and 0 for slave.
2418 - drivers/i2c/rcar_i2c.c:
2419 - activate this driver with CONFIG_SYS_I2C_RCAR
2420 - This driver adds 4 i2c buses
2422 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2423 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2424 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2425 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2426 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2427 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2428 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2429 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2430 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2432 - drivers/i2c/sh_i2c.c:
2433 - activate this driver with CONFIG_SYS_I2C_SH
2434 - This driver adds from 2 to 5 i2c buses
2436 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2437 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2438 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2439 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2440 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2441 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2442 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2443 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2444 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2445 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2446 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2447 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2448 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2450 - drivers/i2c/omap24xx_i2c.c
2451 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2452 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2453 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2454 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2455 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2456 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2457 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2458 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2459 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2460 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2461 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2463 - drivers/i2c/zynq_i2c.c
2464 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2465 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2466 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2468 - drivers/i2c/s3c24x0_i2c.c:
2469 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2470 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2471 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2472 with a fix speed from 100000 and the slave addr 0!
2474 - drivers/i2c/ihs_i2c.c
2475 - activate this driver with CONFIG_SYS_I2C_IHS
2476 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2477 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2478 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2479 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2480 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2481 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2482 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2483 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2484 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2485 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2486 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2487 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2491 CONFIG_SYS_NUM_I2C_BUSES
2492 Hold the number of i2c buses you want to use. If you
2493 don't use/have i2c muxes on your i2c bus, this
2494 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2497 CONFIG_SYS_I2C_DIRECT_BUS
2498 define this, if you don't use i2c muxes on your hardware.
2499 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2502 CONFIG_SYS_I2C_MAX_HOPS
2503 define how many muxes are maximal consecutively connected
2504 on one i2c bus. If you not use i2c muxes, omit this
2507 CONFIG_SYS_I2C_BUSES
2508 hold a list of buses you want to use, only used if
2509 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2510 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2511 CONFIG_SYS_NUM_I2C_BUSES = 9:
2513 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2514 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2515 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2516 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2517 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2518 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2519 {1, {I2C_NULL_HOP}}, \
2520 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2521 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2525 bus 0 on adapter 0 without a mux
2526 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2527 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2528 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2529 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2530 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2531 bus 6 on adapter 1 without a mux
2532 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2533 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2535 If you do not have i2c muxes on your board, omit this define.
2537 - Legacy I2C Support: CONFIG_HARD_I2C
2539 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2540 provides the following compelling advantages:
2542 - more than one i2c adapter is usable
2543 - approved multibus support
2544 - better i2c mux support
2546 ** Please consider updating your I2C driver now. **
2548 These enable legacy I2C serial bus commands. Defining
2549 CONFIG_HARD_I2C will include the appropriate I2C driver
2550 for the selected CPU.
2552 This will allow you to use i2c commands at the u-boot
2553 command line (as long as you set CONFIG_CMD_I2C in
2554 CONFIG_COMMANDS) and communicate with i2c based realtime
2555 clock chips. See common/cmd_i2c.c for a description of the
2556 command line interface.
2558 CONFIG_HARD_I2C selects a hardware I2C controller.
2560 There are several other quantities that must also be
2561 defined when you define CONFIG_HARD_I2C.
2563 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2564 to be the frequency (in Hz) at which you wish your i2c bus
2565 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2566 the CPU's i2c node address).
2568 Now, the u-boot i2c code for the mpc8xx
2569 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2570 and so its address should therefore be cleared to 0 (See,
2571 eg, MPC823e User's Manual p.16-473). So, set
2572 CONFIG_SYS_I2C_SLAVE to 0.
2574 CONFIG_SYS_I2C_INIT_MPC5XXX
2576 When a board is reset during an i2c bus transfer
2577 chips might think that the current transfer is still
2578 in progress. Reset the slave devices by sending start
2579 commands until the slave device responds.
2581 That's all that's required for CONFIG_HARD_I2C.
2583 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2584 then the following macros need to be defined (examples are
2585 from include/configs/lwmon.h):
2589 (Optional). Any commands necessary to enable the I2C
2590 controller or configure ports.
2592 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2596 (Only for MPC8260 CPU). The I/O port to use (the code
2597 assumes both bits are on the same port). Valid values
2598 are 0..3 for ports A..D.
2602 The code necessary to make the I2C data line active
2603 (driven). If the data line is open collector, this
2606 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2610 The code necessary to make the I2C data line tri-stated
2611 (inactive). If the data line is open collector, this
2614 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2618 Code that returns true if the I2C data line is high,
2621 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2625 If <bit> is true, sets the I2C data line high. If it
2626 is false, it clears it (low).
2628 eg: #define I2C_SDA(bit) \
2629 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2630 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2634 If <bit> is true, sets the I2C clock line high. If it
2635 is false, it clears it (low).
2637 eg: #define I2C_SCL(bit) \
2638 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2639 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2643 This delay is invoked four times per clock cycle so this
2644 controls the rate of data transfer. The data rate thus
2645 is 1 / (I2C_DELAY * 4). Often defined to be something
2648 #define I2C_DELAY udelay(2)
2650 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2652 If your arch supports the generic GPIO framework (asm/gpio.h),
2653 then you may alternatively define the two GPIOs that are to be
2654 used as SCL / SDA. Any of the previous I2C_xxx macros will
2655 have GPIO-based defaults assigned to them as appropriate.
2657 You should define these to the GPIO value as given directly to
2658 the generic GPIO functions.
2660 CONFIG_SYS_I2C_INIT_BOARD
2662 When a board is reset during an i2c bus transfer
2663 chips might think that the current transfer is still
2664 in progress. On some boards it is possible to access
2665 the i2c SCLK line directly, either by using the
2666 processor pin as a GPIO or by having a second pin
2667 connected to the bus. If this option is defined a
2668 custom i2c_init_board() routine in boards/xxx/board.c
2669 is run early in the boot sequence.
2671 CONFIG_SYS_I2C_BOARD_LATE_INIT
2673 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2674 defined a custom i2c_board_late_init() routine in
2675 boards/xxx/board.c is run AFTER the operations in i2c_init()
2676 is completed. This callpoint can be used to unreset i2c bus
2677 using CPU i2c controller register accesses for CPUs whose i2c
2678 controller provide such a method. It is called at the end of
2679 i2c_init() to allow i2c_init operations to setup the i2c bus
2680 controller on the CPU (e.g. setting bus speed & slave address).
2682 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2684 This option enables configuration of bi_iic_fast[] flags
2685 in u-boot bd_info structure based on u-boot environment
2686 variable "i2cfast". (see also i2cfast)
2688 CONFIG_I2C_MULTI_BUS
2690 This option allows the use of multiple I2C buses, each of which
2691 must have a controller. At any point in time, only one bus is
2692 active. To switch to a different bus, use the 'i2c dev' command.
2693 Note that bus numbering is zero-based.
2695 CONFIG_SYS_I2C_NOPROBES
2697 This option specifies a list of I2C devices that will be skipped
2698 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2699 is set, specify a list of bus-device pairs. Otherwise, specify
2700 a 1D array of device addresses
2703 #undef CONFIG_I2C_MULTI_BUS
2704 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2706 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2708 #define CONFIG_I2C_MULTI_BUS
2709 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2711 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2713 CONFIG_SYS_SPD_BUS_NUM
2715 If defined, then this indicates the I2C bus number for DDR SPD.
2716 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2718 CONFIG_SYS_RTC_BUS_NUM
2720 If defined, then this indicates the I2C bus number for the RTC.
2721 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2723 CONFIG_SYS_DTT_BUS_NUM
2725 If defined, then this indicates the I2C bus number for the DTT.
2726 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2728 CONFIG_SYS_I2C_DTT_ADDR:
2730 If defined, specifies the I2C address of the DTT device.
2731 If not defined, then U-Boot uses predefined value for
2732 specified DTT device.
2734 CONFIG_SOFT_I2C_READ_REPEATED_START
2736 defining this will force the i2c_read() function in
2737 the soft_i2c driver to perform an I2C repeated start
2738 between writing the address pointer and reading the
2739 data. If this define is omitted the default behaviour
2740 of doing a stop-start sequence will be used. Most I2C
2741 devices can use either method, but some require one or
2744 - SPI Support: CONFIG_SPI
2746 Enables SPI driver (so far only tested with
2747 SPI EEPROM, also an instance works with Crystal A/D and
2748 D/As on the SACSng board)
2752 Enables the driver for SPI controller on SuperH. Currently
2753 only SH7757 is supported.
2757 Enables extended (16-bit) SPI EEPROM addressing.
2758 (symmetrical to CONFIG_I2C_X)
2762 Enables a software (bit-bang) SPI driver rather than
2763 using hardware support. This is a general purpose
2764 driver that only requires three general I/O port pins
2765 (two outputs, one input) to function. If this is
2766 defined, the board configuration must define several
2767 SPI configuration items (port pins to use, etc). For
2768 an example, see include/configs/sacsng.h.
2772 Enables a hardware SPI driver for general-purpose reads
2773 and writes. As with CONFIG_SOFT_SPI, the board configuration
2774 must define a list of chip-select function pointers.
2775 Currently supported on some MPC8xxx processors. For an
2776 example, see include/configs/mpc8349emds.h.
2780 Enables the driver for the SPI controllers on i.MX and MXC
2781 SoCs. Currently i.MX31/35/51 are supported.
2783 CONFIG_SYS_SPI_MXC_WAIT
2784 Timeout for waiting until spi transfer completed.
2785 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2787 - FPGA Support: CONFIG_FPGA
2789 Enables FPGA subsystem.
2791 CONFIG_FPGA_<vendor>
2793 Enables support for specific chip vendors.
2796 CONFIG_FPGA_<family>
2798 Enables support for FPGA family.
2799 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2803 Specify the number of FPGA devices to support.
2805 CONFIG_CMD_FPGA_LOADMK
2807 Enable support for fpga loadmk command
2809 CONFIG_CMD_FPGA_LOADP
2811 Enable support for fpga loadp command - load partial bitstream
2813 CONFIG_CMD_FPGA_LOADBP
2815 Enable support for fpga loadbp command - load partial bitstream
2818 CONFIG_SYS_FPGA_PROG_FEEDBACK
2820 Enable printing of hash marks during FPGA configuration.
2822 CONFIG_SYS_FPGA_CHECK_BUSY
2824 Enable checks on FPGA configuration interface busy
2825 status by the configuration function. This option
2826 will require a board or device specific function to
2831 If defined, a function that provides delays in the FPGA
2832 configuration driver.
2834 CONFIG_SYS_FPGA_CHECK_CTRLC
2835 Allow Control-C to interrupt FPGA configuration
2837 CONFIG_SYS_FPGA_CHECK_ERROR
2839 Check for configuration errors during FPGA bitfile
2840 loading. For example, abort during Virtex II
2841 configuration if the INIT_B line goes low (which
2842 indicated a CRC error).
2844 CONFIG_SYS_FPGA_WAIT_INIT
2846 Maximum time to wait for the INIT_B line to de-assert
2847 after PROB_B has been de-asserted during a Virtex II
2848 FPGA configuration sequence. The default time is 500
2851 CONFIG_SYS_FPGA_WAIT_BUSY
2853 Maximum time to wait for BUSY to de-assert during
2854 Virtex II FPGA configuration. The default is 5 ms.
2856 CONFIG_SYS_FPGA_WAIT_CONFIG
2858 Time to wait after FPGA configuration. The default is
2861 - Configuration Management:
2864 Some SoCs need special image types (e.g. U-Boot binary
2865 with a special header) as build targets. By defining
2866 CONFIG_BUILD_TARGET in the SoC / board header, this
2867 special image will be automatically built upon calling
2872 If defined, this string will be added to the U-Boot
2873 version information (U_BOOT_VERSION)
2875 - Vendor Parameter Protection:
2877 U-Boot considers the values of the environment
2878 variables "serial#" (Board Serial Number) and
2879 "ethaddr" (Ethernet Address) to be parameters that
2880 are set once by the board vendor / manufacturer, and
2881 protects these variables from casual modification by
2882 the user. Once set, these variables are read-only,
2883 and write or delete attempts are rejected. You can
2884 change this behaviour:
2886 If CONFIG_ENV_OVERWRITE is #defined in your config
2887 file, the write protection for vendor parameters is
2888 completely disabled. Anybody can change or delete
2891 Alternatively, if you #define _both_ CONFIG_ETHADDR
2892 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2893 Ethernet address is installed in the environment,
2894 which can be changed exactly ONCE by the user. [The
2895 serial# is unaffected by this, i. e. it remains
2898 The same can be accomplished in a more flexible way
2899 for any variable by configuring the type of access
2900 to allow for those variables in the ".flags" variable
2901 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2906 Define this variable to enable the reservation of
2907 "protected RAM", i. e. RAM which is not overwritten
2908 by U-Boot. Define CONFIG_PRAM to hold the number of
2909 kB you want to reserve for pRAM. You can overwrite
2910 this default value by defining an environment
2911 variable "pram" to the number of kB you want to
2912 reserve. Note that the board info structure will
2913 still show the full amount of RAM. If pRAM is
2914 reserved, a new environment variable "mem" will
2915 automatically be defined to hold the amount of
2916 remaining RAM in a form that can be passed as boot
2917 argument to Linux, for instance like that:
2919 setenv bootargs ... mem=\${mem}
2922 This way you can tell Linux not to use this memory,
2923 either, which results in a memory region that will
2924 not be affected by reboots.
2926 *WARNING* If your board configuration uses automatic
2927 detection of the RAM size, you must make sure that
2928 this memory test is non-destructive. So far, the
2929 following board configurations are known to be
2932 IVMS8, IVML24, SPD8xx, TQM8xxL,
2933 HERMES, IP860, RPXlite, LWMON,
2936 - Access to physical memory region (> 4GB)
2937 Some basic support is provided for operations on memory not
2938 normally accessible to U-Boot - e.g. some architectures
2939 support access to more than 4GB of memory on 32-bit
2940 machines using physical address extension or similar.
2941 Define CONFIG_PHYSMEM to access this basic support, which
2942 currently only supports clearing the memory.
2947 Define this variable to stop the system in case of a
2948 fatal error, so that you have to reset it manually.
2949 This is probably NOT a good idea for an embedded
2950 system where you want the system to reboot
2951 automatically as fast as possible, but it may be
2952 useful during development since you can try to debug
2953 the conditions that lead to the situation.
2955 CONFIG_NET_RETRY_COUNT
2957 This variable defines the number of retries for
2958 network operations like ARP, RARP, TFTP, or BOOTP
2959 before giving up the operation. If not defined, a
2960 default value of 5 is used.
2964 Timeout waiting for an ARP reply in milliseconds.
2968 Timeout in milliseconds used in NFS protocol.
2969 If you encounter "ERROR: Cannot umount" in nfs command,
2970 try longer timeout such as
2971 #define CONFIG_NFS_TIMEOUT 10000UL
2973 - Command Interpreter:
2974 CONFIG_AUTO_COMPLETE
2976 Enable auto completion of commands using TAB.
2978 CONFIG_SYS_PROMPT_HUSH_PS2
2980 This defines the secondary prompt string, which is
2981 printed when the command interpreter needs more input
2982 to complete a command. Usually "> ".
2986 In the current implementation, the local variables
2987 space and global environment variables space are
2988 separated. Local variables are those you define by
2989 simply typing `name=value'. To access a local
2990 variable later on, you have write `$name' or
2991 `${name}'; to execute the contents of a variable
2992 directly type `$name' at the command prompt.
2994 Global environment variables are those you use
2995 setenv/printenv to work with. To run a command stored
2996 in such a variable, you need to use the run command,
2997 and you must not use the '$' sign to access them.
2999 To store commands and special characters in a
3000 variable, please use double quotation marks
3001 surrounding the whole text of the variable, instead
3002 of the backslashes before semicolons and special
3005 - Command Line Editing and History:
3006 CONFIG_CMDLINE_EDITING
3008 Enable editing and History functions for interactive
3009 command line input operations
3011 - Default Environment:
3012 CONFIG_EXTRA_ENV_SETTINGS
3014 Define this to contain any number of null terminated
3015 strings (variable = value pairs) that will be part of
3016 the default environment compiled into the boot image.
3018 For example, place something like this in your
3019 board's config file:
3021 #define CONFIG_EXTRA_ENV_SETTINGS \
3025 Warning: This method is based on knowledge about the
3026 internal format how the environment is stored by the
3027 U-Boot code. This is NOT an official, exported
3028 interface! Although it is unlikely that this format
3029 will change soon, there is no guarantee either.
3030 You better know what you are doing here.
3032 Note: overly (ab)use of the default environment is
3033 discouraged. Make sure to check other ways to preset
3034 the environment like the "source" command or the
3037 CONFIG_ENV_VARS_UBOOT_CONFIG
3039 Define this in order to add variables describing the
3040 U-Boot build configuration to the default environment.
3041 These will be named arch, cpu, board, vendor, and soc.
3043 Enabling this option will cause the following to be defined:
3051 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3053 Define this in order to add variables describing certain
3054 run-time determined information about the hardware to the
3055 environment. These will be named board_name, board_rev.
3057 CONFIG_DELAY_ENVIRONMENT
3059 Normally the environment is loaded when the board is
3060 initialised so that it is available to U-Boot. This inhibits
3061 that so that the environment is not available until
3062 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3063 this is instead controlled by the value of
3064 /config/load-environment.
3066 - DataFlash Support:
3067 CONFIG_HAS_DATAFLASH
3069 Defining this option enables DataFlash features and
3070 allows to read/write in Dataflash via the standard
3073 - Serial Flash support
3076 Defining this option enables SPI flash commands
3077 'sf probe/read/write/erase/update'.
3079 Usage requires an initial 'probe' to define the serial
3080 flash parameters, followed by read/write/erase/update
3083 The following defaults may be provided by the platform
3084 to handle the common case when only a single serial
3085 flash is present on the system.
3087 CONFIG_SF_DEFAULT_BUS Bus identifier
3088 CONFIG_SF_DEFAULT_CS Chip-select
3089 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3090 CONFIG_SF_DEFAULT_SPEED in Hz
3094 Define this option to include a destructive SPI flash
3097 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3099 Define this option to use the Bank addr/Extended addr
3100 support on SPI flashes which has size > 16Mbytes.
3102 CONFIG_SF_DUAL_FLASH Dual flash memories
3104 Define this option to use dual flash support where two flash
3105 memories can be connected with a given cs line.
3106 Currently Xilinx Zynq qspi supports these type of connections.
3108 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3109 enable the W#/Vpp signal to disable writing to the status
3110 register on ST MICRON flashes like the N25Q128.
3111 The status register write enable/disable bit, combined with
3112 the W#/VPP signal provides hardware data protection for the
3113 device as follows: When the enable/disable bit is set to 1,
3114 and the W#/VPP signal is driven LOW, the status register
3115 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3116 operation will not execute. The only way to exit this
3117 hardware-protected mode is to drive W#/VPP HIGH.
3119 - SystemACE Support:
3122 Adding this option adds support for Xilinx SystemACE
3123 chips attached via some sort of local bus. The address
3124 of the chip must also be defined in the
3125 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3127 #define CONFIG_SYSTEMACE
3128 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3130 When SystemACE support is added, the "ace" device type
3131 becomes available to the fat commands, i.e. fatls.
3133 - TFTP Fixed UDP Port:
3136 If this is defined, the environment variable tftpsrcp
3137 is used to supply the TFTP UDP source port value.
3138 If tftpsrcp isn't defined, the normal pseudo-random port
3139 number generator is used.
3141 Also, the environment variable tftpdstp is used to supply
3142 the TFTP UDP destination port value. If tftpdstp isn't
3143 defined, the normal port 69 is used.
3145 The purpose for tftpsrcp is to allow a TFTP server to
3146 blindly start the TFTP transfer using the pre-configured
3147 target IP address and UDP port. This has the effect of
3148 "punching through" the (Windows XP) firewall, allowing
3149 the remainder of the TFTP transfer to proceed normally.
3150 A better solution is to properly configure the firewall,
3151 but sometimes that is not allowed.
3156 This enables a generic 'hash' command which can produce
3157 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3161 Enable the hash verify command (hash -v). This adds to code
3164 CONFIG_SHA1 - support SHA1 hashing
3165 CONFIG_SHA256 - support SHA256 hashing
3167 Note: There is also a sha1sum command, which should perhaps
3168 be deprecated in favour of 'hash sha1'.
3170 - Freescale i.MX specific commands:
3171 CONFIG_CMD_HDMIDETECT
3172 This enables 'hdmidet' command which returns true if an
3173 HDMI monitor is detected. This command is i.MX 6 specific.
3176 This enables the 'bmode' (bootmode) command for forcing
3177 a boot from specific media.
3179 This is useful for forcing the ROM's usb downloader to
3180 activate upon a watchdog reset which is nice when iterating
3181 on U-Boot. Using the reset button or running bmode normal
3182 will set it back to normal. This command currently
3183 supports i.MX53 and i.MX6.
3188 This enables the RSA algorithm used for FIT image verification
3189 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3191 The signing part is build into mkimage regardless of this
3194 - bootcount support:
3195 CONFIG_BOOTCOUNT_LIMIT
3197 This enables the bootcounter support, see:
3198 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3201 enable special bootcounter support on at91sam9xe based boards.
3203 enable special bootcounter support on blackfin based boards.
3205 enable special bootcounter support on da850 based boards.
3206 CONFIG_BOOTCOUNT_RAM
3207 enable support for the bootcounter in RAM
3208 CONFIG_BOOTCOUNT_I2C
3209 enable support for the bootcounter on an i2c (like RTC) device.
3210 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3211 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3213 CONFIG_BOOTCOUNT_ALEN = address len
3215 - Show boot progress:
3216 CONFIG_SHOW_BOOT_PROGRESS
3218 Defining this option allows to add some board-
3219 specific code (calling a user-provided function
3220 "show_boot_progress(int)") that enables you to show
3221 the system's boot progress on some display (for
3222 example, some LED's) on your board. At the moment,
3223 the following checkpoints are implemented:
3225 - Detailed boot stage timing
3227 Define this option to get detailed timing of each stage
3228 of the boot process.
3230 CONFIG_BOOTSTAGE_USER_COUNT
3231 This is the number of available user bootstage records.
3232 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3233 a new ID will be allocated from this stash. If you exceed
3234 the limit, recording will stop.
3236 CONFIG_BOOTSTAGE_REPORT
3237 Define this to print a report before boot, similar to this:
3239 Timer summary in microseconds:
3242 3,575,678 3,575,678 board_init_f start
3243 3,575,695 17 arch_cpu_init A9
3244 3,575,777 82 arch_cpu_init done
3245 3,659,598 83,821 board_init_r start
3246 3,910,375 250,777 main_loop
3247 29,916,167 26,005,792 bootm_start
3248 30,361,327 445,160 start_kernel
3250 CONFIG_CMD_BOOTSTAGE
3251 Add a 'bootstage' command which supports printing a report
3252 and un/stashing of bootstage data.
3254 CONFIG_BOOTSTAGE_FDT
3255 Stash the bootstage information in the FDT. A root 'bootstage'
3256 node is created with each bootstage id as a child. Each child
3257 has a 'name' property and either 'mark' containing the
3258 mark time in microsecond, or 'accum' containing the
3259 accumulated time for that bootstage id in microseconds.
3264 name = "board_init_f";
3273 Code in the Linux kernel can find this in /proc/devicetree.
3275 Legacy uImage format:
3278 1 common/cmd_bootm.c before attempting to boot an image
3279 -1 common/cmd_bootm.c Image header has bad magic number
3280 2 common/cmd_bootm.c Image header has correct magic number
3281 -2 common/cmd_bootm.c Image header has bad checksum
3282 3 common/cmd_bootm.c Image header has correct checksum
3283 -3 common/cmd_bootm.c Image data has bad checksum
3284 4 common/cmd_bootm.c Image data has correct checksum
3285 -4 common/cmd_bootm.c Image is for unsupported architecture
3286 5 common/cmd_bootm.c Architecture check OK
3287 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3288 6 common/cmd_bootm.c Image Type check OK
3289 -6 common/cmd_bootm.c gunzip uncompression error
3290 -7 common/cmd_bootm.c Unimplemented compression type
3291 7 common/cmd_bootm.c Uncompression OK
3292 8 common/cmd_bootm.c No uncompress/copy overwrite error
3293 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3295 9 common/image.c Start initial ramdisk verification
3296 -10 common/image.c Ramdisk header has bad magic number
3297 -11 common/image.c Ramdisk header has bad checksum
3298 10 common/image.c Ramdisk header is OK
3299 -12 common/image.c Ramdisk data has bad checksum
3300 11 common/image.c Ramdisk data has correct checksum
3301 12 common/image.c Ramdisk verification complete, start loading
3302 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3303 13 common/image.c Start multifile image verification
3304 14 common/image.c No initial ramdisk, no multifile, continue.
3306 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3308 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3309 -31 post/post.c POST test failed, detected by post_output_backlog()
3310 -32 post/post.c POST test failed, detected by post_run_single()
3312 34 common/cmd_doc.c before loading a Image from a DOC device
3313 -35 common/cmd_doc.c Bad usage of "doc" command
3314 35 common/cmd_doc.c correct usage of "doc" command
3315 -36 common/cmd_doc.c No boot device
3316 36 common/cmd_doc.c correct boot device
3317 -37 common/cmd_doc.c Unknown Chip ID on boot device
3318 37 common/cmd_doc.c correct chip ID found, device available
3319 -38 common/cmd_doc.c Read Error on boot device
3320 38 common/cmd_doc.c reading Image header from DOC device OK
3321 -39 common/cmd_doc.c Image header has bad magic number
3322 39 common/cmd_doc.c Image header has correct magic number
3323 -40 common/cmd_doc.c Error reading Image from DOC device
3324 40 common/cmd_doc.c Image header has correct magic number
3325 41 common/cmd_ide.c before loading a Image from a IDE device
3326 -42 common/cmd_ide.c Bad usage of "ide" command
3327 42 common/cmd_ide.c correct usage of "ide" command
3328 -43 common/cmd_ide.c No boot device
3329 43 common/cmd_ide.c boot device found
3330 -44 common/cmd_ide.c Device not available
3331 44 common/cmd_ide.c Device available
3332 -45 common/cmd_ide.c wrong partition selected
3333 45 common/cmd_ide.c partition selected
3334 -46 common/cmd_ide.c Unknown partition table
3335 46 common/cmd_ide.c valid partition table found
3336 -47 common/cmd_ide.c Invalid partition type
3337 47 common/cmd_ide.c correct partition type
3338 -48 common/cmd_ide.c Error reading Image Header on boot device
3339 48 common/cmd_ide.c reading Image Header from IDE device OK
3340 -49 common/cmd_ide.c Image header has bad magic number
3341 49 common/cmd_ide.c Image header has correct magic number
3342 -50 common/cmd_ide.c Image header has bad checksum
3343 50 common/cmd_ide.c Image header has correct checksum
3344 -51 common/cmd_ide.c Error reading Image from IDE device
3345 51 common/cmd_ide.c reading Image from IDE device OK
3346 52 common/cmd_nand.c before loading a Image from a NAND device
3347 -53 common/cmd_nand.c Bad usage of "nand" command
3348 53 common/cmd_nand.c correct usage of "nand" command
3349 -54 common/cmd_nand.c No boot device
3350 54 common/cmd_nand.c boot device found
3351 -55 common/cmd_nand.c Unknown Chip ID on boot device
3352 55 common/cmd_nand.c correct chip ID found, device available
3353 -56 common/cmd_nand.c Error reading Image Header on boot device
3354 56 common/cmd_nand.c reading Image Header from NAND device OK
3355 -57 common/cmd_nand.c Image header has bad magic number
3356 57 common/cmd_nand.c Image header has correct magic number
3357 -58 common/cmd_nand.c Error reading Image from NAND device
3358 58 common/cmd_nand.c reading Image from NAND device OK
3360 -60 common/env_common.c Environment has a bad CRC, using default
3362 64 net/eth.c starting with Ethernet configuration.
3363 -64 net/eth.c no Ethernet found.
3364 65 net/eth.c Ethernet found.
3366 -80 common/cmd_net.c usage wrong
3367 80 common/cmd_net.c before calling NetLoop()
3368 -81 common/cmd_net.c some error in NetLoop() occurred
3369 81 common/cmd_net.c NetLoop() back without error
3370 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3371 82 common/cmd_net.c trying automatic boot
3372 83 common/cmd_net.c running "source" command
3373 -83 common/cmd_net.c some error in automatic boot or "source" command
3374 84 common/cmd_net.c end without errors
3379 100 common/cmd_bootm.c Kernel FIT Image has correct format
3380 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3381 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3382 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3383 102 common/cmd_bootm.c Kernel unit name specified
3384 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3385 103 common/cmd_bootm.c Found configuration node
3386 104 common/cmd_bootm.c Got kernel subimage node offset
3387 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3388 105 common/cmd_bootm.c Kernel subimage hash verification OK
3389 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3390 106 common/cmd_bootm.c Architecture check OK
3391 -106 common/cmd_bootm.c Kernel subimage has wrong type
3392 107 common/cmd_bootm.c Kernel subimage type OK
3393 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3394 108 common/cmd_bootm.c Got kernel subimage data/size
3395 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3396 -109 common/cmd_bootm.c Can't get kernel subimage type
3397 -110 common/cmd_bootm.c Can't get kernel subimage comp
3398 -111 common/cmd_bootm.c Can't get kernel subimage os
3399 -112 common/cmd_bootm.c Can't get kernel subimage load address
3400 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3402 120 common/image.c Start initial ramdisk verification
3403 -120 common/image.c Ramdisk FIT image has incorrect format
3404 121 common/image.c Ramdisk FIT image has correct format
3405 122 common/image.c No ramdisk subimage unit name, using configuration
3406 -122 common/image.c Can't get configuration for ramdisk subimage
3407 123 common/image.c Ramdisk unit name specified
3408 -124 common/image.c Can't get ramdisk subimage node offset
3409 125 common/image.c Got ramdisk subimage node offset
3410 -125 common/image.c Ramdisk subimage hash verification failed
3411 126 common/image.c Ramdisk subimage hash verification OK
3412 -126 common/image.c Ramdisk subimage for unsupported architecture
3413 127 common/image.c Architecture check OK
3414 -127 common/image.c Can't get ramdisk subimage data/size
3415 128 common/image.c Got ramdisk subimage data/size
3416 129 common/image.c Can't get ramdisk load address
3417 -129 common/image.c Got ramdisk load address
3419 -130 common/cmd_doc.c Incorrect FIT image format
3420 131 common/cmd_doc.c FIT image format OK
3422 -140 common/cmd_ide.c Incorrect FIT image format
3423 141 common/cmd_ide.c FIT image format OK
3425 -150 common/cmd_nand.c Incorrect FIT image format
3426 151 common/cmd_nand.c FIT image format OK
3428 - legacy image format:
3429 CONFIG_IMAGE_FORMAT_LEGACY
3430 enables the legacy image format support in U-Boot.
3433 enabled if CONFIG_FIT_SIGNATURE is not defined.
3435 CONFIG_DISABLE_IMAGE_LEGACY
3436 disable the legacy image format
3438 This define is introduced, as the legacy image format is
3439 enabled per default for backward compatibility.
3441 - FIT image support:
3443 Enable support for the FIT uImage format.
3445 CONFIG_FIT_BEST_MATCH
3446 When no configuration is explicitly selected, default to the
3447 one whose fdt's compatibility field best matches that of
3448 U-Boot itself. A match is considered "best" if it matches the
3449 most specific compatibility entry of U-Boot's fdt's root node.
3450 The order of entries in the configuration's fdt is ignored.
3452 CONFIG_FIT_SIGNATURE
3453 This option enables signature verification of FIT uImages,
3454 using a hash signed and verified using RSA. See
3455 doc/uImage.FIT/signature.txt for more details.
3457 WARNING: When relying on signed FIT images with required
3458 signature check the legacy image format is default
3459 disabled. If a board need legacy image format support
3460 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3462 CONFIG_FIT_DISABLE_SHA256
3463 Supporting SHA256 hashes has quite an impact on binary size.
3464 For constrained systems sha256 hash support can be disabled
3467 - Standalone program support:
3468 CONFIG_STANDALONE_LOAD_ADDR
3470 This option defines a board specific value for the
3471 address where standalone program gets loaded, thus
3472 overwriting the architecture dependent default
3475 - Frame Buffer Address:
3478 Define CONFIG_FB_ADDR if you want to use specific
3479 address for frame buffer. This is typically the case
3480 when using a graphics controller has separate video
3481 memory. U-Boot will then place the frame buffer at
3482 the given address instead of dynamically reserving it
3483 in system RAM by calling lcd_setmem(), which grabs
3484 the memory for the frame buffer depending on the
3485 configured panel size.
3487 Please see board_init_f function.
3489 - Automatic software updates via TFTP server
3491 CONFIG_UPDATE_TFTP_CNT_MAX
3492 CONFIG_UPDATE_TFTP_MSEC_MAX
3494 These options enable and control the auto-update feature;
3495 for a more detailed description refer to doc/README.update.
3497 - MTD Support (mtdparts command, UBI support)
3500 Adds the MTD device infrastructure from the Linux kernel.
3501 Needed for mtdparts command support.
3503 CONFIG_MTD_PARTITIONS
3505 Adds the MTD partitioning infrastructure from the Linux
3506 kernel. Needed for UBI support.
3508 CONFIG_MTD_NAND_VERIFY_WRITE
3509 verify if the written data is correct reread.
3514 Adds commands for interacting with MTD partitions formatted
3515 with the UBI flash translation layer
3517 Requires also defining CONFIG_RBTREE
3519 CONFIG_UBI_SILENCE_MSG
3521 Make the verbose messages from UBI stop printing. This leaves
3522 warnings and errors enabled.
3525 CONFIG_MTD_UBI_WL_THRESHOLD
3526 This parameter defines the maximum difference between the highest
3527 erase counter value and the lowest erase counter value of eraseblocks
3528 of UBI devices. When this threshold is exceeded, UBI starts performing
3529 wear leveling by means of moving data from eraseblock with low erase
3530 counter to eraseblocks with high erase counter.
3532 The default value should be OK for SLC NAND flashes, NOR flashes and
3533 other flashes which have eraseblock life-cycle 100000 or more.
3534 However, in case of MLC NAND flashes which typically have eraseblock
3535 life-cycle less than 10000, the threshold should be lessened (e.g.,
3536 to 128 or 256, although it does not have to be power of 2).
3540 CONFIG_MTD_UBI_BEB_LIMIT
3541 This option specifies the maximum bad physical eraseblocks UBI
3542 expects on the MTD device (per 1024 eraseblocks). If the
3543 underlying flash does not admit of bad eraseblocks (e.g. NOR
3544 flash), this value is ignored.
3546 NAND datasheets often specify the minimum and maximum NVM
3547 (Number of Valid Blocks) for the flashes' endurance lifetime.
3548 The maximum expected bad eraseblocks per 1024 eraseblocks
3549 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3550 which gives 20 for most NANDs (MaxNVB is basically the total
3551 count of eraseblocks on the chip).
3553 To put it differently, if this value is 20, UBI will try to
3554 reserve about 1.9% of physical eraseblocks for bad blocks
3555 handling. And that will be 1.9% of eraseblocks on the entire
3556 NAND chip, not just the MTD partition UBI attaches. This means
3557 that if you have, say, a NAND flash chip admits maximum 40 bad
3558 eraseblocks, and it is split on two MTD partitions of the same
3559 size, UBI will reserve 40 eraseblocks when attaching a
3564 CONFIG_MTD_UBI_FASTMAP
3565 Fastmap is a mechanism which allows attaching an UBI device
3566 in nearly constant time. Instead of scanning the whole MTD device it
3567 only has to locate a checkpoint (called fastmap) on the device.
3568 The on-flash fastmap contains all information needed to attach
3569 the device. Using fastmap makes only sense on large devices where
3570 attaching by scanning takes long. UBI will not automatically install
3571 a fastmap on old images, but you can set the UBI parameter
3572 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3573 that fastmap-enabled images are still usable with UBI implementations
3574 without fastmap support. On typical flash devices the whole fastmap
3575 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3577 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3578 Set this parameter to enable fastmap automatically on images
3585 Adds commands for interacting with UBI volumes formatted as
3586 UBIFS. UBIFS is read-only in u-boot.
3588 Requires UBI support as well as CONFIG_LZO
3590 CONFIG_UBIFS_SILENCE_MSG
3592 Make the verbose messages from UBIFS stop printing. This leaves
3593 warnings and errors enabled.
3597 Enable building of SPL globally.
3600 LDSCRIPT for linking the SPL binary.
3602 CONFIG_SPL_MAX_FOOTPRINT
3603 Maximum size in memory allocated to the SPL, BSS included.
3604 When defined, the linker checks that the actual memory
3605 used by SPL from _start to __bss_end does not exceed it.
3606 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3607 must not be both defined at the same time.
3610 Maximum size of the SPL image (text, data, rodata, and
3611 linker lists sections), BSS excluded.
3612 When defined, the linker checks that the actual size does
3615 CONFIG_SPL_TEXT_BASE
3616 TEXT_BASE for linking the SPL binary.
3618 CONFIG_SPL_RELOC_TEXT_BASE
3619 Address to relocate to. If unspecified, this is equal to
3620 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3622 CONFIG_SPL_BSS_START_ADDR
3623 Link address for the BSS within the SPL binary.
3625 CONFIG_SPL_BSS_MAX_SIZE
3626 Maximum size in memory allocated to the SPL BSS.
3627 When defined, the linker checks that the actual memory used
3628 by SPL from __bss_start to __bss_end does not exceed it.
3629 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3630 must not be both defined at the same time.
3633 Adress of the start of the stack SPL will use
3635 CONFIG_SPL_RELOC_STACK
3636 Adress of the start of the stack SPL will use after
3637 relocation. If unspecified, this is equal to
3640 CONFIG_SYS_SPL_MALLOC_START
3641 Starting address of the malloc pool used in SPL.
3643 CONFIG_SYS_SPL_MALLOC_SIZE
3644 The size of the malloc pool used in SPL.
3646 CONFIG_SPL_FRAMEWORK
3647 Enable the SPL framework under common/. This framework
3648 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3649 NAND loading of the Linux Kernel.
3652 Enable booting directly to an OS from SPL.
3653 See also: doc/README.falcon
3655 CONFIG_SPL_DISPLAY_PRINT
3656 For ARM, enable an optional function to print more information
3657 about the running system.
3659 CONFIG_SPL_INIT_MINIMAL
3660 Arch init code should be built for a very small image
3662 CONFIG_SPL_LIBCOMMON_SUPPORT
3663 Support for common/libcommon.o in SPL binary
3665 CONFIG_SPL_LIBDISK_SUPPORT
3666 Support for disk/libdisk.o in SPL binary
3668 CONFIG_SPL_I2C_SUPPORT
3669 Support for drivers/i2c/libi2c.o in SPL binary
3671 CONFIG_SPL_GPIO_SUPPORT
3672 Support for drivers/gpio/libgpio.o in SPL binary
3674 CONFIG_SPL_MMC_SUPPORT
3675 Support for drivers/mmc/libmmc.o in SPL binary
3677 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3678 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3679 Address and partition on the MMC to load U-Boot from
3680 when the MMC is being used in raw mode.
3682 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3683 Partition on the MMC to load U-Boot from when the MMC is being
3686 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3687 Sector to load kernel uImage from when MMC is being
3688 used in raw mode (for Falcon mode)
3690 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3691 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3692 Sector and number of sectors to load kernel argument
3693 parameters from when MMC is being used in raw mode
3696 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3697 Partition on the MMC to load U-Boot from when the MMC is being
3700 CONFIG_SPL_FAT_SUPPORT
3701 Support for fs/fat/libfat.o in SPL binary
3703 CONFIG_SPL_EXT_SUPPORT
3704 Support for EXT filesystem in SPL binary
3706 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3707 Filename to read to load U-Boot when reading from filesystem
3709 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3710 Filename to read to load kernel uImage when reading
3711 from filesystem (for Falcon mode)
3713 CONFIG_SPL_FS_LOAD_ARGS_NAME
3714 Filename to read to load kernel argument parameters
3715 when reading from filesystem (for Falcon mode)
3717 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3718 Set this for NAND SPL on PPC mpc83xx targets, so that
3719 start.S waits for the rest of the SPL to load before
3720 continuing (the hardware starts execution after just
3721 loading the first page rather than the full 4K).
3723 CONFIG_SPL_SKIP_RELOCATE
3724 Avoid SPL relocation
3726 CONFIG_SPL_NAND_BASE
3727 Include nand_base.c in the SPL. Requires
3728 CONFIG_SPL_NAND_DRIVERS.
3730 CONFIG_SPL_NAND_DRIVERS
3731 SPL uses normal NAND drivers, not minimal drivers.
3734 Include standard software ECC in the SPL
3736 CONFIG_SPL_NAND_SIMPLE
3737 Support for NAND boot using simple NAND drivers that
3738 expose the cmd_ctrl() interface.
3740 CONFIG_SPL_MTD_SUPPORT
3741 Support for the MTD subsystem within SPL. Useful for
3742 environment on NAND support within SPL.
3744 CONFIG_SPL_NAND_RAW_ONLY
3745 Support to boot only raw u-boot.bin images. Use this only
3746 if you need to save space.
3748 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3749 Set for the SPL on PPC mpc8xxx targets, support for
3750 drivers/ddr/fsl/libddr.o in SPL binary.
3752 CONFIG_SPL_COMMON_INIT_DDR
3753 Set for common ddr init with serial presence detect in
3756 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3757 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3758 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3759 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3760 CONFIG_SYS_NAND_ECCBYTES
3761 Defines the size and behavior of the NAND that SPL uses
3764 CONFIG_SPL_NAND_BOOT
3765 Add support NAND boot
3767 CONFIG_SYS_NAND_U_BOOT_OFFS
3768 Location in NAND to read U-Boot from
3770 CONFIG_SYS_NAND_U_BOOT_DST
3771 Location in memory to load U-Boot to
3773 CONFIG_SYS_NAND_U_BOOT_SIZE
3774 Size of image to load
3776 CONFIG_SYS_NAND_U_BOOT_START
3777 Entry point in loaded image to jump to
3779 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3780 Define this if you need to first read the OOB and then the
3781 data. This is used, for example, on davinci platforms.
3783 CONFIG_SPL_OMAP3_ID_NAND
3784 Support for an OMAP3-specific set of functions to return the
3785 ID and MFR of the first attached NAND chip, if present.
3787 CONFIG_SPL_SERIAL_SUPPORT
3788 Support for drivers/serial/libserial.o in SPL binary
3790 CONFIG_SPL_SPI_FLASH_SUPPORT
3791 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3793 CONFIG_SPL_SPI_SUPPORT
3794 Support for drivers/spi/libspi.o in SPL binary
3796 CONFIG_SPL_RAM_DEVICE
3797 Support for running image already present in ram, in SPL binary
3799 CONFIG_SPL_LIBGENERIC_SUPPORT
3800 Support for lib/libgeneric.o in SPL binary
3802 CONFIG_SPL_ENV_SUPPORT
3803 Support for the environment operating in SPL binary
3805 CONFIG_SPL_NET_SUPPORT
3806 Support for the net/libnet.o in SPL binary.
3807 It conflicts with SPL env from storage medium specified by
3808 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3811 Image offset to which the SPL should be padded before appending
3812 the SPL payload. By default, this is defined as
3813 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3814 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3815 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3818 Final target image containing SPL and payload. Some SPLs
3819 use an arch-specific makefile fragment instead, for
3820 example if more than one image needs to be produced.
3822 CONFIG_FIT_SPL_PRINT
3823 Printing information about a FIT image adds quite a bit of
3824 code to SPL. So this is normally disabled in SPL. Use this
3825 option to re-enable it. This will affect the output of the
3826 bootm command when booting a FIT image.
3830 Enable building of TPL globally.
3833 Image offset to which the TPL should be padded before appending
3834 the TPL payload. By default, this is defined as
3835 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3836 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3837 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3842 [so far only for SMDK2400 boards]
3844 - Modem support enable:
3845 CONFIG_MODEM_SUPPORT
3847 - RTS/CTS Flow control enable:
3850 - Modem debug support:
3851 CONFIG_MODEM_SUPPORT_DEBUG
3853 Enables debugging stuff (char screen[1024], dbg())
3854 for modem support. Useful only with BDI2000.
3856 - Interrupt support (PPC):
3858 There are common interrupt_init() and timer_interrupt()
3859 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3860 for CPU specific initialization. interrupt_init_cpu()
3861 should set decrementer_count to appropriate value. If
3862 CPU resets decrementer automatically after interrupt
3863 (ppc4xx) it should set decrementer_count to zero.
3864 timer_interrupt() calls timer_interrupt_cpu() for CPU
3865 specific handling. If board has watchdog / status_led
3866 / other_activity_monitor it works automatically from
3867 general timer_interrupt().
3871 In the target system modem support is enabled when a
3872 specific key (key combination) is pressed during
3873 power-on. Otherwise U-Boot will boot normally
3874 (autoboot). The key_pressed() function is called from
3875 board_init(). Currently key_pressed() is a dummy
3876 function, returning 1 and thus enabling modem
3879 If there are no modem init strings in the
3880 environment, U-Boot proceed to autoboot; the
3881 previous output (banner, info printfs) will be
3884 See also: doc/README.Modem
3886 Board initialization settings:
3887 ------------------------------
3889 During Initialization u-boot calls a number of board specific functions
3890 to allow the preparation of board specific prerequisites, e.g. pin setup
3891 before drivers are initialized. To enable these callbacks the
3892 following configuration macros have to be defined. Currently this is
3893 architecture specific, so please check arch/your_architecture/lib/board.c
3894 typically in board_init_f() and board_init_r().
3896 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3897 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3898 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3899 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3901 Configuration Settings:
3902 -----------------------
3904 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3905 Optionally it can be defined to support 64-bit memory commands.
3907 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3908 undefine this when you're short of memory.
3910 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3911 width of the commands listed in the 'help' command output.
3913 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3914 prompt for user input.
3916 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3918 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3920 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3922 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3923 the application (usually a Linux kernel) when it is
3926 - CONFIG_SYS_BAUDRATE_TABLE:
3927 List of legal baudrate settings for this board.
3929 - CONFIG_SYS_CONSOLE_INFO_QUIET
3930 Suppress display of console information at boot.
3932 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3933 If the board specific function
3934 extern int overwrite_console (void);
3935 returns 1, the stdin, stderr and stdout are switched to the
3936 serial port, else the settings in the environment are used.
3938 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3939 Enable the call to overwrite_console().
3941 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3942 Enable overwrite of previous console environment settings.
3944 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3945 Begin and End addresses of the area used by the
3948 - CONFIG_SYS_ALT_MEMTEST:
3949 Enable an alternate, more extensive memory test.
3951 - CONFIG_SYS_MEMTEST_SCRATCH:
3952 Scratch address used by the alternate memory test
3953 You only need to set this if address zero isn't writeable
3955 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3956 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3957 this specified memory area will get subtracted from the top
3958 (end) of RAM and won't get "touched" at all by U-Boot. By
3959 fixing up gd->ram_size the Linux kernel should gets passed
3960 the now "corrected" memory size and won't touch it either.
3961 This should work for arch/ppc and arch/powerpc. Only Linux
3962 board ports in arch/powerpc with bootwrapper support that
3963 recalculate the memory size from the SDRAM controller setup
3964 will have to get fixed in Linux additionally.
3966 This option can be used as a workaround for the 440EPx/GRx
3967 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3970 WARNING: Please make sure that this value is a multiple of
3971 the Linux page size (normally 4k). If this is not the case,
3972 then the end address of the Linux memory will be located at a
3973 non page size aligned address and this could cause major
3976 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3977 Enable temporary baudrate change while serial download
3979 - CONFIG_SYS_SDRAM_BASE:
3980 Physical start address of SDRAM. _Must_ be 0 here.
3982 - CONFIG_SYS_MBIO_BASE:
3983 Physical start address of Motherboard I/O (if using a
3986 - CONFIG_SYS_FLASH_BASE:
3987 Physical start address of Flash memory.
3989 - CONFIG_SYS_MONITOR_BASE:
3990 Physical start address of boot monitor code (set by
3991 make config files to be same as the text base address
3992 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3993 CONFIG_SYS_FLASH_BASE when booting from flash.
3995 - CONFIG_SYS_MONITOR_LEN:
3996 Size of memory reserved for monitor code, used to
3997 determine _at_compile_time_ (!) if the environment is
3998 embedded within the U-Boot image, or in a separate
4001 - CONFIG_SYS_MALLOC_LEN:
4002 Size of DRAM reserved for malloc() use.
4004 - CONFIG_SYS_MALLOC_F_LEN
4005 Size of the malloc() pool for use before relocation. If
4006 this is defined, then a very simple malloc() implementation
4007 will become available before relocation. The address is just
4008 below the global data, and the stack is moved down to make
4011 This feature allocates regions with increasing addresses
4012 within the region. calloc() is supported, but realloc()
4013 is not available. free() is supported but does nothing.
4014 The memory will be freed (or in fact just forgotten) when
4015 U-Boot relocates itself.
4017 Pre-relocation malloc() is only supported on ARM and sandbox
4018 at present but is fairly easy to enable for other archs.
4020 - CONFIG_SYS_MALLOC_SIMPLE
4021 Provides a simple and small malloc() and calloc() for those
4022 boards which do not use the full malloc in SPL (which is
4023 enabled with CONFIG_SYS_SPL_MALLOC_START).
4025 - CONFIG_SYS_NONCACHED_MEMORY:
4026 Size of non-cached memory area. This area of memory will be
4027 typically located right below the malloc() area and mapped
4028 uncached in the MMU. This is useful for drivers that would
4029 otherwise require a lot of explicit cache maintenance. For
4030 some drivers it's also impossible to properly maintain the
4031 cache. For example if the regions that need to be flushed
4032 are not a multiple of the cache-line size, *and* padding
4033 cannot be allocated between the regions to align them (i.e.
4034 if the HW requires a contiguous array of regions, and the
4035 size of each region is not cache-aligned), then a flush of
4036 one region may result in overwriting data that hardware has
4037 written to another region in the same cache-line. This can
4038 happen for example in network drivers where descriptors for
4039 buffers are typically smaller than the CPU cache-line (e.g.
4040 16 bytes vs. 32 or 64 bytes).
4042 Non-cached memory is only supported on 32-bit ARM at present.
4044 - CONFIG_SYS_BOOTM_LEN:
4045 Normally compressed uImages are limited to an
4046 uncompressed size of 8 MBytes. If this is not enough,
4047 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4048 to adjust this setting to your needs.
4050 - CONFIG_SYS_BOOTMAPSZ:
4051 Maximum size of memory mapped by the startup code of
4052 the Linux kernel; all data that must be processed by
4053 the Linux kernel (bd_info, boot arguments, FDT blob if
4054 used) must be put below this limit, unless "bootm_low"
4055 environment variable is defined and non-zero. In such case
4056 all data for the Linux kernel must be between "bootm_low"
4057 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4058 variable "bootm_mapsize" will override the value of
4059 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4060 then the value in "bootm_size" will be used instead.
4062 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4063 Enable initrd_high functionality. If defined then the
4064 initrd_high feature is enabled and the bootm ramdisk subcommand
4067 - CONFIG_SYS_BOOT_GET_CMDLINE:
4068 Enables allocating and saving kernel cmdline in space between
4069 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4071 - CONFIG_SYS_BOOT_GET_KBD:
4072 Enables allocating and saving a kernel copy of the bd_info in
4073 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4075 - CONFIG_SYS_MAX_FLASH_BANKS:
4076 Max number of Flash memory banks
4078 - CONFIG_SYS_MAX_FLASH_SECT:
4079 Max number of sectors on a Flash chip
4081 - CONFIG_SYS_FLASH_ERASE_TOUT:
4082 Timeout for Flash erase operations (in ms)
4084 - CONFIG_SYS_FLASH_WRITE_TOUT:
4085 Timeout for Flash write operations (in ms)
4087 - CONFIG_SYS_FLASH_LOCK_TOUT
4088 Timeout for Flash set sector lock bit operation (in ms)
4090 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4091 Timeout for Flash clear lock bits operation (in ms)
4093 - CONFIG_SYS_FLASH_PROTECTION
4094 If defined, hardware flash sectors protection is used
4095 instead of U-Boot software protection.
4097 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4099 Enable TFTP transfers directly to flash memory;
4100 without this option such a download has to be
4101 performed in two steps: (1) download to RAM, and (2)
4102 copy from RAM to flash.
4104 The two-step approach is usually more reliable, since
4105 you can check if the download worked before you erase
4106 the flash, but in some situations (when system RAM is
4107 too limited to allow for a temporary copy of the
4108 downloaded image) this option may be very useful.
4110 - CONFIG_SYS_FLASH_CFI:
4111 Define if the flash driver uses extra elements in the
4112 common flash structure for storing flash geometry.
4114 - CONFIG_FLASH_CFI_DRIVER
4115 This option also enables the building of the cfi_flash driver
4116 in the drivers directory
4118 - CONFIG_FLASH_CFI_MTD
4119 This option enables the building of the cfi_mtd driver
4120 in the drivers directory. The driver exports CFI flash
4123 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4124 Use buffered writes to flash.
4126 - CONFIG_FLASH_SPANSION_S29WS_N
4127 s29ws-n MirrorBit flash has non-standard addresses for buffered
4130 - CONFIG_SYS_FLASH_QUIET_TEST
4131 If this option is defined, the common CFI flash doesn't
4132 print it's warning upon not recognized FLASH banks. This
4133 is useful, if some of the configured banks are only
4134 optionally available.
4136 - CONFIG_FLASH_SHOW_PROGRESS
4137 If defined (must be an integer), print out countdown
4138 digits and dots. Recommended value: 45 (9..1) for 80
4139 column displays, 15 (3..1) for 40 column displays.
4141 - CONFIG_FLASH_VERIFY
4142 If defined, the content of the flash (destination) is compared
4143 against the source after the write operation. An error message
4144 will be printed when the contents are not identical.
4145 Please note that this option is useless in nearly all cases,
4146 since such flash programming errors usually are detected earlier
4147 while unprotecting/erasing/programming. Please only enable
4148 this option if you really know what you are doing.
4150 - CONFIG_SYS_RX_ETH_BUFFER:
4151 Defines the number of Ethernet receive buffers. On some
4152 Ethernet controllers it is recommended to set this value
4153 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4154 buffers can be full shortly after enabling the interface
4155 on high Ethernet traffic.
4156 Defaults to 4 if not defined.
4158 - CONFIG_ENV_MAX_ENTRIES
4160 Maximum number of entries in the hash table that is used
4161 internally to store the environment settings. The default
4162 setting is supposed to be generous and should work in most
4163 cases. This setting can be used to tune behaviour; see
4164 lib/hashtable.c for details.
4166 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4167 - CONFIG_ENV_FLAGS_LIST_STATIC
4168 Enable validation of the values given to environment variables when
4169 calling env set. Variables can be restricted to only decimal,
4170 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4171 the variables can also be restricted to IP address or MAC address.
4173 The format of the list is:
4174 type_attribute = [s|d|x|b|i|m]
4175 access_attribute = [a|r|o|c]
4176 attributes = type_attribute[access_attribute]
4177 entry = variable_name[:attributes]
4180 The type attributes are:
4181 s - String (default)
4184 b - Boolean ([1yYtT|0nNfF])
4188 The access attributes are:
4194 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4195 Define this to a list (string) to define the ".flags"
4196 environment variable in the default or embedded environment.
4198 - CONFIG_ENV_FLAGS_LIST_STATIC
4199 Define this to a list (string) to define validation that
4200 should be done if an entry is not found in the ".flags"
4201 environment variable. To override a setting in the static
4202 list, simply add an entry for the same variable name to the
4205 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4206 If defined, don't allow the -f switch to env set override variable
4209 - CONFIG_SYS_GENERIC_BOARD
4210 This selects the architecture-generic board system instead of the
4211 architecture-specific board files. It is intended to move boards
4212 to this new framework over time. Defining this will disable the
4213 arch/foo/lib/board.c file and use common/board_f.c and
4214 common/board_r.c instead. To use this option your architecture
4215 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4216 its config.mk file). If you find problems enabling this option on
4217 your board please report the problem and send patches!
4219 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4220 This is set by OMAP boards for the max time that reset should
4221 be asserted. See doc/README.omap-reset-time for details on how
4222 the value can be calculated on a given board.
4225 If stdint.h is available with your toolchain you can define this
4226 option to enable it. You can provide option 'USE_STDINT=1' when
4227 building U-Boot to enable this.
4229 The following definitions that deal with the placement and management
4230 of environment data (variable area); in general, we support the
4231 following configurations:
4233 - CONFIG_BUILD_ENVCRC:
4235 Builds up envcrc with the target environment so that external utils
4236 may easily extract it and embed it in final U-Boot images.
4238 - CONFIG_ENV_IS_IN_FLASH:
4240 Define this if the environment is in flash memory.
4242 a) The environment occupies one whole flash sector, which is
4243 "embedded" in the text segment with the U-Boot code. This
4244 happens usually with "bottom boot sector" or "top boot
4245 sector" type flash chips, which have several smaller
4246 sectors at the start or the end. For instance, such a
4247 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4248 such a case you would place the environment in one of the
4249 4 kB sectors - with U-Boot code before and after it. With
4250 "top boot sector" type flash chips, you would put the
4251 environment in one of the last sectors, leaving a gap
4252 between U-Boot and the environment.
4254 - CONFIG_ENV_OFFSET:
4256 Offset of environment data (variable area) to the
4257 beginning of flash memory; for instance, with bottom boot
4258 type flash chips the second sector can be used: the offset
4259 for this sector is given here.
4261 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4265 This is just another way to specify the start address of
4266 the flash sector containing the environment (instead of
4269 - CONFIG_ENV_SECT_SIZE:
4271 Size of the sector containing the environment.
4274 b) Sometimes flash chips have few, equal sized, BIG sectors.
4275 In such a case you don't want to spend a whole sector for
4280 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4281 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4282 of this flash sector for the environment. This saves
4283 memory for the RAM copy of the environment.
4285 It may also save flash memory if you decide to use this
4286 when your environment is "embedded" within U-Boot code,
4287 since then the remainder of the flash sector could be used
4288 for U-Boot code. It should be pointed out that this is
4289 STRONGLY DISCOURAGED from a robustness point of view:
4290 updating the environment in flash makes it always
4291 necessary to erase the WHOLE sector. If something goes
4292 wrong before the contents has been restored from a copy in
4293 RAM, your target system will be dead.
4295 - CONFIG_ENV_ADDR_REDUND
4296 CONFIG_ENV_SIZE_REDUND
4298 These settings describe a second storage area used to hold
4299 a redundant copy of the environment data, so that there is
4300 a valid backup copy in case there is a power failure during
4301 a "saveenv" operation.
4303 BE CAREFUL! Any changes to the flash layout, and some changes to the
4304 source code will make it necessary to adapt <board>/u-boot.lds*
4308 - CONFIG_ENV_IS_IN_NVRAM:
4310 Define this if you have some non-volatile memory device
4311 (NVRAM, battery buffered SRAM) which you want to use for the
4317 These two #defines are used to determine the memory area you
4318 want to use for environment. It is assumed that this memory
4319 can just be read and written to, without any special
4322 BE CAREFUL! The first access to the environment happens quite early
4323 in U-Boot initialization (when we try to get the setting of for the
4324 console baudrate). You *MUST* have mapped your NVRAM area then, or
4327 Please note that even with NVRAM we still use a copy of the
4328 environment in RAM: we could work on NVRAM directly, but we want to
4329 keep settings there always unmodified except somebody uses "saveenv"
4330 to save the current settings.
4333 - CONFIG_ENV_IS_IN_EEPROM:
4335 Use this if you have an EEPROM or similar serial access
4336 device and a driver for it.
4338 - CONFIG_ENV_OFFSET:
4341 These two #defines specify the offset and size of the
4342 environment area within the total memory of your EEPROM.
4344 - CONFIG_SYS_I2C_EEPROM_ADDR:
4345 If defined, specified the chip address of the EEPROM device.
4346 The default address is zero.
4348 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4349 If defined, the number of bits used to address bytes in a
4350 single page in the EEPROM device. A 64 byte page, for example
4351 would require six bits.
4353 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4354 If defined, the number of milliseconds to delay between
4355 page writes. The default is zero milliseconds.
4357 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4358 The length in bytes of the EEPROM memory array address. Note
4359 that this is NOT the chip address length!
4361 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4362 EEPROM chips that implement "address overflow" are ones
4363 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4364 address and the extra bits end up in the "chip address" bit
4365 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4368 Note that we consider the length of the address field to
4369 still be one byte because the extra address bits are hidden
4370 in the chip address.
4372 - CONFIG_SYS_EEPROM_SIZE:
4373 The size in bytes of the EEPROM device.
4375 - CONFIG_ENV_EEPROM_IS_ON_I2C
4376 define this, if you have I2C and SPI activated, and your
4377 EEPROM, which holds the environment, is on the I2C bus.
4379 - CONFIG_I2C_ENV_EEPROM_BUS
4380 if you have an Environment on an EEPROM reached over
4381 I2C muxes, you can define here, how to reach this
4382 EEPROM. For example:
4384 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4386 EEPROM which holds the environment, is reached over
4387 a pca9547 i2c mux with address 0x70, channel 3.
4389 - CONFIG_ENV_IS_IN_DATAFLASH:
4391 Define this if you have a DataFlash memory device which you
4392 want to use for the environment.
4394 - CONFIG_ENV_OFFSET:
4398 These three #defines specify the offset and size of the
4399 environment area within the total memory of your DataFlash placed
4400 at the specified address.
4402 - CONFIG_ENV_IS_IN_SPI_FLASH:
4404 Define this if you have a SPI Flash memory device which you
4405 want to use for the environment.
4407 - CONFIG_ENV_OFFSET:
4410 These two #defines specify the offset and size of the
4411 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4412 aligned to an erase sector boundary.
4414 - CONFIG_ENV_SECT_SIZE:
4416 Define the SPI flash's sector size.
4418 - CONFIG_ENV_OFFSET_REDUND (optional):
4420 This setting describes a second storage area of CONFIG_ENV_SIZE
4421 size used to hold a redundant copy of the environment data, so
4422 that there is a valid backup copy in case there is a power failure
4423 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4424 aligned to an erase sector boundary.
4426 - CONFIG_ENV_SPI_BUS (optional):
4427 - CONFIG_ENV_SPI_CS (optional):
4429 Define the SPI bus and chip select. If not defined they will be 0.
4431 - CONFIG_ENV_SPI_MAX_HZ (optional):
4433 Define the SPI max work clock. If not defined then use 1MHz.
4435 - CONFIG_ENV_SPI_MODE (optional):
4437 Define the SPI work mode. If not defined then use SPI_MODE_3.
4439 - CONFIG_ENV_IS_IN_REMOTE:
4441 Define this if you have a remote memory space which you
4442 want to use for the local device's environment.
4447 These two #defines specify the address and size of the
4448 environment area within the remote memory space. The
4449 local device can get the environment from remote memory
4450 space by SRIO or PCIE links.
4452 BE CAREFUL! For some special cases, the local device can not use
4453 "saveenv" command. For example, the local device will get the
4454 environment stored in a remote NOR flash by SRIO or PCIE link,
4455 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4457 - CONFIG_ENV_IS_IN_NAND:
4459 Define this if you have a NAND device which you want to use
4460 for the environment.
4462 - CONFIG_ENV_OFFSET:
4465 These two #defines specify the offset and size of the environment
4466 area within the first NAND device. CONFIG_ENV_OFFSET must be
4467 aligned to an erase block boundary.
4469 - CONFIG_ENV_OFFSET_REDUND (optional):
4471 This setting describes a second storage area of CONFIG_ENV_SIZE
4472 size used to hold a redundant copy of the environment data, so
4473 that there is a valid backup copy in case there is a power failure
4474 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4475 aligned to an erase block boundary.
4477 - CONFIG_ENV_RANGE (optional):
4479 Specifies the length of the region in which the environment
4480 can be written. This should be a multiple of the NAND device's
4481 block size. Specifying a range with more erase blocks than
4482 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4483 the range to be avoided.
4485 - CONFIG_ENV_OFFSET_OOB (optional):
4487 Enables support for dynamically retrieving the offset of the
4488 environment from block zero's out-of-band data. The
4489 "nand env.oob" command can be used to record this offset.
4490 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4491 using CONFIG_ENV_OFFSET_OOB.
4493 - CONFIG_NAND_ENV_DST
4495 Defines address in RAM to which the nand_spl code should copy the
4496 environment. If redundant environment is used, it will be copied to
4497 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4499 - CONFIG_ENV_IS_IN_UBI:
4501 Define this if you have an UBI volume that you want to use for the
4502 environment. This has the benefit of wear-leveling the environment
4503 accesses, which is important on NAND.
4505 - CONFIG_ENV_UBI_PART:
4507 Define this to a string that is the mtd partition containing the UBI.
4509 - CONFIG_ENV_UBI_VOLUME:
4511 Define this to the name of the volume that you want to store the
4514 - CONFIG_ENV_UBI_VOLUME_REDUND:
4516 Define this to the name of another volume to store a second copy of
4517 the environment in. This will enable redundant environments in UBI.
4518 It is assumed that both volumes are in the same MTD partition.
4520 - CONFIG_UBI_SILENCE_MSG
4521 - CONFIG_UBIFS_SILENCE_MSG
4523 You will probably want to define these to avoid a really noisy system
4524 when storing the env in UBI.
4526 - CONFIG_ENV_IS_IN_FAT:
4527 Define this if you want to use the FAT file system for the environment.
4529 - FAT_ENV_INTERFACE:
4531 Define this to a string that is the name of the block device.
4533 - FAT_ENV_DEV_AND_PART:
4535 Define this to a string to specify the partition of the device. It can
4538 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4539 - "D:P": device D partition P. Error occurs if device D has no
4542 - "D" or "D:": device D partition 1 if device D has partition
4543 table, or the whole device D if has no partition
4545 - "D:auto": first partition in device D with bootable flag set.
4546 If none, first valid partition in device D. If no
4547 partition table then means device D.
4551 It's a string of the FAT file name. This file use to store the
4555 This should be defined. Otherwise it cannot save the environment file.
4557 - CONFIG_ENV_IS_IN_MMC:
4559 Define this if you have an MMC device which you want to use for the
4562 - CONFIG_SYS_MMC_ENV_DEV:
4564 Specifies which MMC device the environment is stored in.
4566 - CONFIG_SYS_MMC_ENV_PART (optional):
4568 Specifies which MMC partition the environment is stored in. If not
4569 set, defaults to partition 0, the user area. Common values might be
4570 1 (first MMC boot partition), 2 (second MMC boot partition).
4572 - CONFIG_ENV_OFFSET:
4575 These two #defines specify the offset and size of the environment
4576 area within the specified MMC device.
4578 If offset is positive (the usual case), it is treated as relative to
4579 the start of the MMC partition. If offset is negative, it is treated
4580 as relative to the end of the MMC partition. This can be useful if
4581 your board may be fitted with different MMC devices, which have
4582 different sizes for the MMC partitions, and you always want the
4583 environment placed at the very end of the partition, to leave the
4584 maximum possible space before it, to store other data.
4586 These two values are in units of bytes, but must be aligned to an
4587 MMC sector boundary.
4589 - CONFIG_ENV_OFFSET_REDUND (optional):
4591 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4592 hold a redundant copy of the environment data. This provides a
4593 valid backup copy in case the other copy is corrupted, e.g. due
4594 to a power failure during a "saveenv" operation.
4596 This value may also be positive or negative; this is handled in the
4597 same way as CONFIG_ENV_OFFSET.
4599 This value is also in units of bytes, but must also be aligned to
4600 an MMC sector boundary.
4602 - CONFIG_ENV_SIZE_REDUND (optional):
4604 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4605 set. If this value is set, it must be set to the same value as
4608 - CONFIG_SYS_SPI_INIT_OFFSET
4610 Defines offset to the initial SPI buffer area in DPRAM. The
4611 area is used at an early stage (ROM part) if the environment
4612 is configured to reside in the SPI EEPROM: We need a 520 byte
4613 scratch DPRAM area. It is used between the two initialization
4614 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4615 to be a good choice since it makes it far enough from the
4616 start of the data area as well as from the stack pointer.
4618 Please note that the environment is read-only until the monitor
4619 has been relocated to RAM and a RAM copy of the environment has been
4620 created; also, when using EEPROM you will have to use getenv_f()
4621 until then to read environment variables.
4623 The environment is protected by a CRC32 checksum. Before the monitor
4624 is relocated into RAM, as a result of a bad CRC you will be working
4625 with the compiled-in default environment - *silently*!!! [This is
4626 necessary, because the first environment variable we need is the
4627 "baudrate" setting for the console - if we have a bad CRC, we don't
4628 have any device yet where we could complain.]
4630 Note: once the monitor has been relocated, then it will complain if
4631 the default environment is used; a new CRC is computed as soon as you
4632 use the "saveenv" command to store a valid environment.
4634 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4635 Echo the inverted Ethernet link state to the fault LED.
4637 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4638 also needs to be defined.
4640 - CONFIG_SYS_FAULT_MII_ADDR:
4641 MII address of the PHY to check for the Ethernet link state.
4643 - CONFIG_NS16550_MIN_FUNCTIONS:
4644 Define this if you desire to only have use of the NS16550_init
4645 and NS16550_putc functions for the serial driver located at
4646 drivers/serial/ns16550.c. This option is useful for saving
4647 space for already greatly restricted images, including but not
4648 limited to NAND_SPL configurations.
4650 - CONFIG_DISPLAY_BOARDINFO
4651 Display information about the board that U-Boot is running on
4652 when U-Boot starts up. The board function checkboard() is called
4655 - CONFIG_DISPLAY_BOARDINFO_LATE
4656 Similar to the previous option, but display this information
4657 later, once stdio is running and output goes to the LCD, if
4660 - CONFIG_BOARD_SIZE_LIMIT:
4661 Maximum size of the U-Boot image. When defined, the
4662 build system checks that the actual size does not
4665 Low Level (hardware related) configuration options:
4666 ---------------------------------------------------
4668 - CONFIG_SYS_CACHELINE_SIZE:
4669 Cache Line Size of the CPU.
4671 - CONFIG_SYS_DEFAULT_IMMR:
4672 Default address of the IMMR after system reset.
4674 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4675 and RPXsuper) to be able to adjust the position of
4676 the IMMR register after a reset.
4678 - CONFIG_SYS_CCSRBAR_DEFAULT:
4679 Default (power-on reset) physical address of CCSR on Freescale
4682 - CONFIG_SYS_CCSRBAR:
4683 Virtual address of CCSR. On a 32-bit build, this is typically
4684 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4686 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4687 for cross-platform code that uses that macro instead.
4689 - CONFIG_SYS_CCSRBAR_PHYS:
4690 Physical address of CCSR. CCSR can be relocated to a new
4691 physical address, if desired. In this case, this macro should
4692 be set to that address. Otherwise, it should be set to the
4693 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4694 is typically relocated on 36-bit builds. It is recommended
4695 that this macro be defined via the _HIGH and _LOW macros:
4697 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4698 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4700 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4701 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4702 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4703 used in assembly code, so it must not contain typecasts or
4704 integer size suffixes (e.g. "ULL").
4706 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4707 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4708 used in assembly code, so it must not contain typecasts or
4709 integer size suffixes (e.g. "ULL").
4711 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4712 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4713 forced to a value that ensures that CCSR is not relocated.
4715 - Floppy Disk Support:
4716 CONFIG_SYS_FDC_DRIVE_NUMBER
4718 the default drive number (default value 0)
4720 CONFIG_SYS_ISA_IO_STRIDE
4722 defines the spacing between FDC chipset registers
4725 CONFIG_SYS_ISA_IO_OFFSET
4727 defines the offset of register from address. It
4728 depends on which part of the data bus is connected to
4729 the FDC chipset. (default value 0)
4731 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4732 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4735 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4736 fdc_hw_init() is called at the beginning of the FDC
4737 setup. fdc_hw_init() must be provided by the board
4738 source code. It is used to make hardware-dependent
4742 Most IDE controllers were designed to be connected with PCI
4743 interface. Only few of them were designed for AHB interface.
4744 When software is doing ATA command and data transfer to
4745 IDE devices through IDE-AHB controller, some additional
4746 registers accessing to these kind of IDE-AHB controller
4749 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4750 DO NOT CHANGE unless you know exactly what you're
4751 doing! (11-4) [MPC8xx/82xx systems only]
4753 - CONFIG_SYS_INIT_RAM_ADDR:
4755 Start address of memory area that can be used for
4756 initial data and stack; please note that this must be
4757 writable memory that is working WITHOUT special
4758 initialization, i. e. you CANNOT use normal RAM which
4759 will become available only after programming the
4760 memory controller and running certain initialization
4763 U-Boot uses the following memory types:
4764 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4765 - MPC824X: data cache
4766 - PPC4xx: data cache
4768 - CONFIG_SYS_GBL_DATA_OFFSET:
4770 Offset of the initial data structure in the memory
4771 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4772 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4773 data is located at the end of the available space
4774 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4775 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4776 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4777 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4780 On the MPC824X (or other systems that use the data
4781 cache for initial memory) the address chosen for
4782 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4783 point to an otherwise UNUSED address space between
4784 the top of RAM and the start of the PCI space.
4786 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4788 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4790 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4792 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4794 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4796 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4798 - CONFIG_SYS_OR_TIMING_SDRAM:
4801 - CONFIG_SYS_MAMR_PTA:
4802 periodic timer for refresh
4804 - CONFIG_SYS_DER: Debug Event Register (37-47)
4806 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4807 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4808 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4809 CONFIG_SYS_BR1_PRELIM:
4810 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4812 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4813 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4814 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4815 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4817 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4818 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4819 Machine Mode Register and Memory Periodic Timer
4820 Prescaler definitions (SDRAM timing)
4822 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4823 enable I2C microcode relocation patch (MPC8xx);
4824 define relocation offset in DPRAM [DSP2]
4826 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4827 enable SMC microcode relocation patch (MPC8xx);
4828 define relocation offset in DPRAM [SMC1]
4830 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4831 enable SPI microcode relocation patch (MPC8xx);
4832 define relocation offset in DPRAM [SCC4]
4834 - CONFIG_SYS_USE_OSCCLK:
4835 Use OSCM clock mode on MBX8xx board. Be careful,
4836 wrong setting might damage your board. Read
4837 doc/README.MBX before setting this variable!
4839 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4840 Offset of the bootmode word in DPRAM used by post
4841 (Power On Self Tests). This definition overrides
4842 #define'd default value in commproc.h resp.
4845 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4846 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4847 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4848 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4849 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4850 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4851 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4852 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4853 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4855 - CONFIG_PCI_DISABLE_PCIE:
4856 Disable PCI-Express on systems where it is supported but not
4859 - CONFIG_PCI_ENUM_ONLY
4860 Only scan through and get the devices on the buses.
4861 Don't do any setup work, presumably because someone or
4862 something has already done it, and we don't need to do it
4863 a second time. Useful for platforms that are pre-booted
4864 by coreboot or similar.
4866 - CONFIG_PCI_INDIRECT_BRIDGE:
4867 Enable support for indirect PCI bridges.
4870 Chip has SRIO or not
4873 Board has SRIO 1 port available
4876 Board has SRIO 2 port available
4878 - CONFIG_SRIO_PCIE_BOOT_MASTER
4879 Board can support master function for Boot from SRIO and PCIE
4881 - CONFIG_SYS_SRIOn_MEM_VIRT:
4882 Virtual Address of SRIO port 'n' memory region
4884 - CONFIG_SYS_SRIOn_MEM_PHYS:
4885 Physical Address of SRIO port 'n' memory region
4887 - CONFIG_SYS_SRIOn_MEM_SIZE:
4888 Size of SRIO port 'n' memory region
4890 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4891 Defined to tell the NAND controller that the NAND chip is using
4893 Not all NAND drivers use this symbol.
4894 Example of drivers that use it:
4895 - drivers/mtd/nand/ndfc.c
4896 - drivers/mtd/nand/mxc_nand.c
4898 - CONFIG_SYS_NDFC_EBC0_CFG
4899 Sets the EBC0_CFG register for the NDFC. If not defined
4900 a default value will be used.
4903 Get DDR timing information from an I2C EEPROM. Common
4904 with pluggable memory modules such as SODIMMs
4907 I2C address of the SPD EEPROM
4909 - CONFIG_SYS_SPD_BUS_NUM
4910 If SPD EEPROM is on an I2C bus other than the first
4911 one, specify here. Note that the value must resolve
4912 to something your driver can deal with.
4914 - CONFIG_SYS_DDR_RAW_TIMING
4915 Get DDR timing information from other than SPD. Common with
4916 soldered DDR chips onboard without SPD. DDR raw timing
4917 parameters are extracted from datasheet and hard-coded into
4918 header files or board specific files.
4920 - CONFIG_FSL_DDR_INTERACTIVE
4921 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4923 - CONFIG_SYS_83XX_DDR_USES_CS0
4924 Only for 83xx systems. If specified, then DDR should
4925 be configured using CS0 and CS1 instead of CS2 and CS3.
4927 - CONFIG_ETHER_ON_FEC[12]
4928 Define to enable FEC[12] on a 8xx series processor.
4930 - CONFIG_FEC[12]_PHY
4931 Define to the hardcoded PHY address which corresponds
4932 to the given FEC; i. e.
4933 #define CONFIG_FEC1_PHY 4
4934 means that the PHY with address 4 is connected to FEC1
4936 When set to -1, means to probe for first available.
4938 - CONFIG_FEC[12]_PHY_NORXERR
4939 The PHY does not have a RXERR line (RMII only).
4940 (so program the FEC to ignore it).
4943 Enable RMII mode for all FECs.
4944 Note that this is a global option, we can't
4945 have one FEC in standard MII mode and another in RMII mode.
4947 - CONFIG_CRC32_VERIFY
4948 Add a verify option to the crc32 command.
4951 => crc32 -v <address> <count> <crc32>
4953 Where address/count indicate a memory area
4954 and crc32 is the correct crc32 which the
4958 Add the "loopw" memory command. This only takes effect if
4959 the memory commands are activated globally (CONFIG_CMD_MEM).
4962 Add the "mdc" and "mwc" memory commands. These are cyclic
4967 This command will print 4 bytes (10,11,12,13) each 500 ms.
4969 => mwc.l 100 12345678 10
4970 This command will write 12345678 to address 100 all 10 ms.
4972 This only takes effect if the memory commands are activated
4973 globally (CONFIG_CMD_MEM).
4975 - CONFIG_SKIP_LOWLEVEL_INIT
4976 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4977 low level initializations (like setting up the memory
4978 controller) are omitted and/or U-Boot does not
4979 relocate itself into RAM.
4981 Normally this variable MUST NOT be defined. The only
4982 exception is when U-Boot is loaded (to RAM) by some
4983 other boot loader or by a debugger which performs
4984 these initializations itself.
4987 Modifies the behaviour of start.S when compiling a loader
4988 that is executed before the actual U-Boot. E.g. when
4989 compiling a NAND SPL.
4992 Modifies the behaviour of start.S when compiling a loader
4993 that is executed after the SPL and before the actual U-Boot.
4994 It is loaded by the SPL.
4996 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4997 Only for 85xx systems. If this variable is specified, the section
4998 .resetvec is not kept and the section .bootpg is placed in the
4999 previous 4k of the .text section.
5001 - CONFIG_ARCH_MAP_SYSMEM
5002 Generally U-Boot (and in particular the md command) uses
5003 effective address. It is therefore not necessary to regard
5004 U-Boot address as virtual addresses that need to be translated
5005 to physical addresses. However, sandbox requires this, since
5006 it maintains its own little RAM buffer which contains all
5007 addressable memory. This option causes some memory accesses
5008 to be mapped through map_sysmem() / unmap_sysmem().
5010 - CONFIG_USE_ARCH_MEMCPY
5011 CONFIG_USE_ARCH_MEMSET
5012 If these options are used a optimized version of memcpy/memset will
5013 be used if available. These functions may be faster under some
5014 conditions but may increase the binary size.
5016 - CONFIG_X86_RESET_VECTOR
5017 If defined, the x86 reset vector code is included. This is not
5018 needed when U-Boot is running from Coreboot.
5021 Defines the MPU clock speed (in MHz).
5023 NOTE : currently only supported on AM335x platforms.
5025 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5026 Enables the RTC32K OSC on AM33xx based plattforms
5028 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5029 Option to disable subpage write in NAND driver
5030 driver that uses this:
5031 drivers/mtd/nand/davinci_nand.c
5033 Freescale QE/FMAN Firmware Support:
5034 -----------------------------------
5036 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5037 loading of "firmware", which is encoded in the QE firmware binary format.
5038 This firmware often needs to be loaded during U-Boot booting, so macros
5039 are used to identify the storage device (NOR flash, SPI, etc) and the address
5042 - CONFIG_SYS_FMAN_FW_ADDR
5043 The address in the storage device where the FMAN microcode is located. The
5044 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5047 - CONFIG_SYS_QE_FW_ADDR
5048 The address in the storage device where the QE microcode is located. The
5049 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5052 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5053 The maximum possible size of the firmware. The firmware binary format
5054 has a field that specifies the actual size of the firmware, but it
5055 might not be possible to read any part of the firmware unless some
5056 local storage is allocated to hold the entire firmware first.
5058 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5059 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5060 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5061 virtual address in NOR flash.
5063 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5064 Specifies that QE/FMAN firmware is located in NAND flash.
5065 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5067 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5068 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5069 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5071 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5072 Specifies that QE/FMAN firmware is located on the primary SPI
5073 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5075 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5076 Specifies that QE/FMAN firmware is located in the remote (master)
5077 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5078 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5079 window->master inbound window->master LAW->the ucode address in
5080 master's memory space.
5082 Freescale Layerscape Management Complex Firmware Support:
5083 ---------------------------------------------------------
5084 The Freescale Layerscape Management Complex (MC) supports the loading of
5086 This firmware often needs to be loaded during U-Boot booting, so macros
5087 are used to identify the storage device (NOR flash, SPI, etc) and the address
5090 - CONFIG_FSL_MC_ENET
5091 Enable the MC driver for Layerscape SoCs.
5093 - CONFIG_SYS_LS_MC_FW_ADDR
5094 The address in the storage device where the firmware is located. The
5095 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5098 - CONFIG_SYS_LS_MC_FW_LENGTH
5099 The maximum possible size of the firmware. The firmware binary format
5100 has a field that specifies the actual size of the firmware, but it
5101 might not be possible to read any part of the firmware unless some
5102 local storage is allocated to hold the entire firmware first.
5104 - CONFIG_SYS_LS_MC_FW_IN_NOR
5105 Specifies that MC firmware is located in NOR flash, mapped as
5106 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5107 virtual address in NOR flash.
5109 Building the Software:
5110 ======================
5112 Building U-Boot has been tested in several native build environments
5113 and in many different cross environments. Of course we cannot support
5114 all possibly existing versions of cross development tools in all
5115 (potentially obsolete) versions. In case of tool chain problems we
5116 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5117 which is extensively used to build and test U-Boot.
5119 If you are not using a native environment, it is assumed that you
5120 have GNU cross compiling tools available in your path. In this case,
5121 you must set the environment variable CROSS_COMPILE in your shell.
5122 Note that no changes to the Makefile or any other source files are
5123 necessary. For example using the ELDK on a 4xx CPU, please enter:
5125 $ CROSS_COMPILE=ppc_4xx-
5126 $ export CROSS_COMPILE
5128 Note: If you wish to generate Windows versions of the utilities in
5129 the tools directory you can use the MinGW toolchain
5130 (http://www.mingw.org). Set your HOST tools to the MinGW
5131 toolchain and execute 'make tools'. For example:
5133 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5135 Binaries such as tools/mkimage.exe will be created which can
5136 be executed on computers running Windows.
5138 U-Boot is intended to be simple to build. After installing the
5139 sources you must configure U-Boot for one specific board type. This
5144 where "NAME_defconfig" is the name of one of the existing configu-
5145 rations; see boards.cfg for supported names.
5147 Note: for some board special configuration names may exist; check if
5148 additional information is available from the board vendor; for
5149 instance, the TQM823L systems are available without (standard)
5150 or with LCD support. You can select such additional "features"
5151 when choosing the configuration, i. e.
5153 make TQM823L_defconfig
5154 - will configure for a plain TQM823L, i. e. no LCD support
5156 make TQM823L_LCD_defconfig
5157 - will configure for a TQM823L with U-Boot console on LCD
5162 Finally, type "make all", and you should get some working U-Boot
5163 images ready for download to / installation on your system:
5165 - "u-boot.bin" is a raw binary image
5166 - "u-boot" is an image in ELF binary format
5167 - "u-boot.srec" is in Motorola S-Record format
5169 By default the build is performed locally and the objects are saved
5170 in the source directory. One of the two methods can be used to change
5171 this behavior and build U-Boot to some external directory:
5173 1. Add O= to the make command line invocations:
5175 make O=/tmp/build distclean
5176 make O=/tmp/build NAME_defconfig
5177 make O=/tmp/build all
5179 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5181 export KBUILD_OUTPUT=/tmp/build
5186 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5190 Please be aware that the Makefiles assume you are using GNU make, so
5191 for instance on NetBSD you might need to use "gmake" instead of
5195 If the system board that you have is not listed, then you will need
5196 to port U-Boot to your hardware platform. To do this, follow these
5199 1. Add a new configuration option for your board to the toplevel
5200 "boards.cfg" file, using the existing entries as examples.
5201 Follow the instructions there to keep the boards in order.
5202 2. Create a new directory to hold your board specific code. Add any
5203 files you need. In your board directory, you will need at least
5204 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5205 3. Create a new configuration file "include/configs/<board>.h" for
5207 3. If you're porting U-Boot to a new CPU, then also create a new
5208 directory to hold your CPU specific code. Add any files you need.
5209 4. Run "make <board>_defconfig" with your new name.
5210 5. Type "make", and you should get a working "u-boot.srec" file
5211 to be installed on your target system.
5212 6. Debug and solve any problems that might arise.
5213 [Of course, this last step is much harder than it sounds.]
5216 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5217 ==============================================================
5219 If you have modified U-Boot sources (for instance added a new board
5220 or support for new devices, a new CPU, etc.) you are expected to
5221 provide feedback to the other developers. The feedback normally takes
5222 the form of a "patch", i. e. a context diff against a certain (latest
5223 official or latest in the git repository) version of U-Boot sources.
5225 But before you submit such a patch, please verify that your modifi-
5226 cation did not break existing code. At least make sure that *ALL* of
5227 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5228 just run the "MAKEALL" script, which will configure and build U-Boot
5229 for ALL supported system. Be warned, this will take a while. You can
5230 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5231 environment variable to the script, i. e. to use the ELDK cross tools
5234 CROSS_COMPILE=ppc_8xx- MAKEALL
5236 or to build on a native PowerPC system you can type
5238 CROSS_COMPILE=' ' MAKEALL
5240 When using the MAKEALL script, the default behaviour is to build
5241 U-Boot in the source directory. This location can be changed by
5242 setting the BUILD_DIR environment variable. Also, for each target
5243 built, the MAKEALL script saves two log files (<target>.ERR and
5244 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5245 location can be changed by setting the MAKEALL_LOGDIR environment
5246 variable. For example:
5248 export BUILD_DIR=/tmp/build
5249 export MAKEALL_LOGDIR=/tmp/log
5250 CROSS_COMPILE=ppc_8xx- MAKEALL
5252 With the above settings build objects are saved in the /tmp/build,
5253 log files are saved in the /tmp/log and the source tree remains clean
5254 during the whole build process.
5257 See also "U-Boot Porting Guide" below.
5260 Monitor Commands - Overview:
5261 ============================
5263 go - start application at address 'addr'
5264 run - run commands in an environment variable
5265 bootm - boot application image from memory
5266 bootp - boot image via network using BootP/TFTP protocol
5267 bootz - boot zImage from memory
5268 tftpboot- boot image via network using TFTP protocol
5269 and env variables "ipaddr" and "serverip"
5270 (and eventually "gatewayip")
5271 tftpput - upload a file via network using TFTP protocol
5272 rarpboot- boot image via network using RARP/TFTP protocol
5273 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5274 loads - load S-Record file over serial line
5275 loadb - load binary file over serial line (kermit mode)
5277 mm - memory modify (auto-incrementing)
5278 nm - memory modify (constant address)
5279 mw - memory write (fill)
5281 cmp - memory compare
5282 crc32 - checksum calculation
5283 i2c - I2C sub-system
5284 sspi - SPI utility commands
5285 base - print or set address offset
5286 printenv- print environment variables
5287 setenv - set environment variables
5288 saveenv - save environment variables to persistent storage
5289 protect - enable or disable FLASH write protection
5290 erase - erase FLASH memory
5291 flinfo - print FLASH memory information
5292 nand - NAND memory operations (see doc/README.nand)
5293 bdinfo - print Board Info structure
5294 iminfo - print header information for application image
5295 coninfo - print console devices and informations
5296 ide - IDE sub-system
5297 loop - infinite loop on address range
5298 loopw - infinite write loop on address range
5299 mtest - simple RAM test
5300 icache - enable or disable instruction cache
5301 dcache - enable or disable data cache
5302 reset - Perform RESET of the CPU
5303 echo - echo args to console
5304 version - print monitor version
5305 help - print online help
5306 ? - alias for 'help'
5309 Monitor Commands - Detailed Description:
5310 ========================================
5314 For now: just type "help <command>".
5317 Environment Variables:
5318 ======================
5320 U-Boot supports user configuration using Environment Variables which
5321 can be made persistent by saving to Flash memory.
5323 Environment Variables are set using "setenv", printed using
5324 "printenv", and saved to Flash using "saveenv". Using "setenv"
5325 without a value can be used to delete a variable from the
5326 environment. As long as you don't save the environment you are
5327 working with an in-memory copy. In case the Flash area containing the
5328 environment is erased by accident, a default environment is provided.
5330 Some configuration options can be set using Environment Variables.
5332 List of environment variables (most likely not complete):
5334 baudrate - see CONFIG_BAUDRATE
5336 bootdelay - see CONFIG_BOOTDELAY
5338 bootcmd - see CONFIG_BOOTCOMMAND
5340 bootargs - Boot arguments when booting an RTOS image
5342 bootfile - Name of the image to load with TFTP
5344 bootm_low - Memory range available for image processing in the bootm
5345 command can be restricted. This variable is given as
5346 a hexadecimal number and defines lowest address allowed
5347 for use by the bootm command. See also "bootm_size"
5348 environment variable. Address defined by "bootm_low" is
5349 also the base of the initial memory mapping for the Linux
5350 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5353 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5354 This variable is given as a hexadecimal number and it
5355 defines the size of the memory region starting at base
5356 address bootm_low that is accessible by the Linux kernel
5357 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5358 as the default value if it is defined, and bootm_size is
5361 bootm_size - Memory range available for image processing in the bootm
5362 command can be restricted. This variable is given as
5363 a hexadecimal number and defines the size of the region
5364 allowed for use by the bootm command. See also "bootm_low"
5365 environment variable.
5367 updatefile - Location of the software update file on a TFTP server, used
5368 by the automatic software update feature. Please refer to
5369 documentation in doc/README.update for more details.
5371 autoload - if set to "no" (any string beginning with 'n'),
5372 "bootp" will just load perform a lookup of the
5373 configuration from the BOOTP server, but not try to
5374 load any image using TFTP
5376 autostart - if set to "yes", an image loaded using the "bootp",
5377 "rarpboot", "tftpboot" or "diskboot" commands will
5378 be automatically started (by internally calling
5381 If set to "no", a standalone image passed to the
5382 "bootm" command will be copied to the load address
5383 (and eventually uncompressed), but NOT be started.
5384 This can be used to load and uncompress arbitrary
5387 fdt_high - if set this restricts the maximum address that the
5388 flattened device tree will be copied into upon boot.
5389 For example, if you have a system with 1 GB memory
5390 at physical address 0x10000000, while Linux kernel
5391 only recognizes the first 704 MB as low memory, you
5392 may need to set fdt_high as 0x3C000000 to have the
5393 device tree blob be copied to the maximum address
5394 of the 704 MB low memory, so that Linux kernel can
5395 access it during the boot procedure.
5397 If this is set to the special value 0xFFFFFFFF then
5398 the fdt will not be copied at all on boot. For this
5399 to work it must reside in writable memory, have
5400 sufficient padding on the end of it for u-boot to
5401 add the information it needs into it, and the memory
5402 must be accessible by the kernel.
5404 fdtcontroladdr- if set this is the address of the control flattened
5405 device tree used by U-Boot when CONFIG_OF_CONTROL is
5408 i2cfast - (PPC405GP|PPC405EP only)
5409 if set to 'y' configures Linux I2C driver for fast
5410 mode (400kHZ). This environment variable is used in
5411 initialization code. So, for changes to be effective
5412 it must be saved and board must be reset.
5414 initrd_high - restrict positioning of initrd images:
5415 If this variable is not set, initrd images will be
5416 copied to the highest possible address in RAM; this
5417 is usually what you want since it allows for
5418 maximum initrd size. If for some reason you want to
5419 make sure that the initrd image is loaded below the
5420 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5421 variable to a value of "no" or "off" or "0".
5422 Alternatively, you can set it to a maximum upper
5423 address to use (U-Boot will still check that it
5424 does not overwrite the U-Boot stack and data).
5426 For instance, when you have a system with 16 MB
5427 RAM, and want to reserve 4 MB from use by Linux,
5428 you can do this by adding "mem=12M" to the value of
5429 the "bootargs" variable. However, now you must make
5430 sure that the initrd image is placed in the first
5431 12 MB as well - this can be done with
5433 setenv initrd_high 00c00000
5435 If you set initrd_high to 0xFFFFFFFF, this is an
5436 indication to U-Boot that all addresses are legal
5437 for the Linux kernel, including addresses in flash
5438 memory. In this case U-Boot will NOT COPY the
5439 ramdisk at all. This may be useful to reduce the
5440 boot time on your system, but requires that this
5441 feature is supported by your Linux kernel.
5443 ipaddr - IP address; needed for tftpboot command
5445 loadaddr - Default load address for commands like "bootp",
5446 "rarpboot", "tftpboot", "loadb" or "diskboot"
5448 loads_echo - see CONFIG_LOADS_ECHO
5450 serverip - TFTP server IP address; needed for tftpboot command
5452 bootretry - see CONFIG_BOOT_RETRY_TIME
5454 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5456 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5458 ethprime - controls which interface is used first.
5460 ethact - controls which interface is currently active.
5461 For example you can do the following
5463 => setenv ethact FEC
5464 => ping 192.168.0.1 # traffic sent on FEC
5465 => setenv ethact SCC
5466 => ping 10.0.0.1 # traffic sent on SCC
5468 ethrotate - When set to "no" U-Boot does not go through all
5469 available network interfaces.
5470 It just stays at the currently selected interface.
5472 netretry - When set to "no" each network operation will
5473 either succeed or fail without retrying.
5474 When set to "once" the network operation will
5475 fail when all the available network interfaces
5476 are tried once without success.
5477 Useful on scripts which control the retry operation
5480 npe_ucode - set load address for the NPE microcode
5482 silent_linux - If set then Linux will be told to boot silently, by
5483 changing the console to be empty. If "yes" it will be
5484 made silent. If "no" it will not be made silent. If
5485 unset, then it will be made silent if the U-Boot console
5488 tftpsrcport - If this is set, the value is used for TFTP's
5491 tftpdstport - If this is set, the value is used for TFTP's UDP
5492 destination port instead of the Well Know Port 69.
5494 tftpblocksize - Block size to use for TFTP transfers; if not set,
5495 we use the TFTP server's default block size
5497 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5498 seconds, minimum value is 1000 = 1 second). Defines
5499 when a packet is considered to be lost so it has to
5500 be retransmitted. The default is 5000 = 5 seconds.
5501 Lowering this value may make downloads succeed
5502 faster in networks with high packet loss rates or
5503 with unreliable TFTP servers.
5505 vlan - When set to a value < 4095 the traffic over
5506 Ethernet is encapsulated/received over 802.1q
5509 The following image location variables contain the location of images
5510 used in booting. The "Image" column gives the role of the image and is
5511 not an environment variable name. The other columns are environment
5512 variable names. "File Name" gives the name of the file on a TFTP
5513 server, "RAM Address" gives the location in RAM the image will be
5514 loaded to, and "Flash Location" gives the image's address in NOR
5515 flash or offset in NAND flash.
5517 *Note* - these variables don't have to be defined for all boards, some
5518 boards currenlty use other variables for these purposes, and some
5519 boards use these variables for other purposes.
5521 Image File Name RAM Address Flash Location
5522 ----- --------- ----------- --------------
5523 u-boot u-boot u-boot_addr_r u-boot_addr
5524 Linux kernel bootfile kernel_addr_r kernel_addr
5525 device tree blob fdtfile fdt_addr_r fdt_addr
5526 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5528 The following environment variables may be used and automatically
5529 updated by the network boot commands ("bootp" and "rarpboot"),
5530 depending the information provided by your boot server:
5532 bootfile - see above
5533 dnsip - IP address of your Domain Name Server
5534 dnsip2 - IP address of your secondary Domain Name Server
5535 gatewayip - IP address of the Gateway (Router) to use
5536 hostname - Target hostname
5538 netmask - Subnet Mask
5539 rootpath - Pathname of the root filesystem on the NFS server
5540 serverip - see above
5543 There are two special Environment Variables:
5545 serial# - contains hardware identification information such
5546 as type string and/or serial number
5547 ethaddr - Ethernet address
5549 These variables can be set only once (usually during manufacturing of
5550 the board). U-Boot refuses to delete or overwrite these variables
5551 once they have been set once.
5554 Further special Environment Variables:
5556 ver - Contains the U-Boot version string as printed
5557 with the "version" command. This variable is
5558 readonly (see CONFIG_VERSION_VARIABLE).
5561 Please note that changes to some configuration parameters may take
5562 only effect after the next boot (yes, that's just like Windoze :-).
5565 Callback functions for environment variables:
5566 ---------------------------------------------
5568 For some environment variables, the behavior of u-boot needs to change
5569 when their values are changed. This functionality allows functions to
5570 be associated with arbitrary variables. On creation, overwrite, or
5571 deletion, the callback will provide the opportunity for some side
5572 effect to happen or for the change to be rejected.
5574 The callbacks are named and associated with a function using the
5575 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5577 These callbacks are associated with variables in one of two ways. The
5578 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5579 in the board configuration to a string that defines a list of
5580 associations. The list must be in the following format:
5582 entry = variable_name[:callback_name]
5585 If the callback name is not specified, then the callback is deleted.
5586 Spaces are also allowed anywhere in the list.
5588 Callbacks can also be associated by defining the ".callbacks" variable
5589 with the same list format above. Any association in ".callbacks" will
5590 override any association in the static list. You can define
5591 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5592 ".callbacks" environment variable in the default or embedded environment.
5595 Command Line Parsing:
5596 =====================
5598 There are two different command line parsers available with U-Boot:
5599 the old "simple" one, and the much more powerful "hush" shell:
5601 Old, simple command line parser:
5602 --------------------------------
5604 - supports environment variables (through setenv / saveenv commands)
5605 - several commands on one line, separated by ';'
5606 - variable substitution using "... ${name} ..." syntax
5607 - special characters ('$', ';') can be escaped by prefixing with '\',
5609 setenv bootcmd bootm \${address}
5610 - You can also escape text by enclosing in single apostrophes, for example:
5611 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5616 - similar to Bourne shell, with control structures like
5617 if...then...else...fi, for...do...done; while...do...done,
5618 until...do...done, ...
5619 - supports environment ("global") variables (through setenv / saveenv
5620 commands) and local shell variables (through standard shell syntax
5621 "name=value"); only environment variables can be used with "run"
5627 (1) If a command line (or an environment variable executed by a "run"
5628 command) contains several commands separated by semicolon, and
5629 one of these commands fails, then the remaining commands will be
5632 (2) If you execute several variables with one call to run (i. e.
5633 calling run with a list of variables as arguments), any failing
5634 command will cause "run" to terminate, i. e. the remaining
5635 variables are not executed.
5637 Note for Redundant Ethernet Interfaces:
5638 =======================================
5640 Some boards come with redundant Ethernet interfaces; U-Boot supports
5641 such configurations and is capable of automatic selection of a
5642 "working" interface when needed. MAC assignment works as follows:
5644 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5645 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5646 "eth1addr" (=>eth1), "eth2addr", ...
5648 If the network interface stores some valid MAC address (for instance
5649 in SROM), this is used as default address if there is NO correspon-
5650 ding setting in the environment; if the corresponding environment
5651 variable is set, this overrides the settings in the card; that means:
5653 o If the SROM has a valid MAC address, and there is no address in the
5654 environment, the SROM's address is used.
5656 o If there is no valid address in the SROM, and a definition in the
5657 environment exists, then the value from the environment variable is
5660 o If both the SROM and the environment contain a MAC address, and
5661 both addresses are the same, this MAC address is used.
5663 o If both the SROM and the environment contain a MAC address, and the
5664 addresses differ, the value from the environment is used and a
5667 o If neither SROM nor the environment contain a MAC address, an error
5670 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5671 will be programmed into hardware as part of the initialization process. This
5672 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5673 The naming convention is as follows:
5674 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5679 U-Boot is capable of booting (and performing other auxiliary operations on)
5680 images in two formats:
5682 New uImage format (FIT)
5683 -----------------------
5685 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5686 to Flattened Device Tree). It allows the use of images with multiple
5687 components (several kernels, ramdisks, etc.), with contents protected by
5688 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5694 Old image format is based on binary files which can be basically anything,
5695 preceded by a special header; see the definitions in include/image.h for
5696 details; basically, the header defines the following image properties:
5698 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5699 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5700 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5701 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5703 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5704 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5705 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5706 * Compression Type (uncompressed, gzip, bzip2)
5712 The header is marked by a special Magic Number, and both the header
5713 and the data portions of the image are secured against corruption by
5720 Although U-Boot should support any OS or standalone application
5721 easily, the main focus has always been on Linux during the design of
5724 U-Boot includes many features that so far have been part of some
5725 special "boot loader" code within the Linux kernel. Also, any
5726 "initrd" images to be used are no longer part of one big Linux image;
5727 instead, kernel and "initrd" are separate images. This implementation
5728 serves several purposes:
5730 - the same features can be used for other OS or standalone
5731 applications (for instance: using compressed images to reduce the
5732 Flash memory footprint)
5734 - it becomes much easier to port new Linux kernel versions because
5735 lots of low-level, hardware dependent stuff are done by U-Boot
5737 - the same Linux kernel image can now be used with different "initrd"
5738 images; of course this also means that different kernel images can
5739 be run with the same "initrd". This makes testing easier (you don't
5740 have to build a new "zImage.initrd" Linux image when you just
5741 change a file in your "initrd"). Also, a field-upgrade of the
5742 software is easier now.
5748 Porting Linux to U-Boot based systems:
5749 ---------------------------------------
5751 U-Boot cannot save you from doing all the necessary modifications to
5752 configure the Linux device drivers for use with your target hardware
5753 (no, we don't intend to provide a full virtual machine interface to
5756 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5758 Just make sure your machine specific header file (for instance
5759 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5760 Information structure as we define in include/asm-<arch>/u-boot.h,
5761 and make sure that your definition of IMAP_ADDR uses the same value
5762 as your U-Boot configuration in CONFIG_SYS_IMMR.
5764 Note that U-Boot now has a driver model, a unified model for drivers.
5765 If you are adding a new driver, plumb it into driver model. If there
5766 is no uclass available, you are encouraged to create one. See
5770 Configuring the Linux kernel:
5771 -----------------------------
5773 No specific requirements for U-Boot. Make sure you have some root
5774 device (initial ramdisk, NFS) for your target system.
5777 Building a Linux Image:
5778 -----------------------
5780 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5781 not used. If you use recent kernel source, a new build target
5782 "uImage" will exist which automatically builds an image usable by
5783 U-Boot. Most older kernels also have support for a "pImage" target,
5784 which was introduced for our predecessor project PPCBoot and uses a
5785 100% compatible format.
5789 make TQM850L_defconfig
5794 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5795 encapsulate a compressed Linux kernel image with header information,
5796 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5798 * build a standard "vmlinux" kernel image (in ELF binary format):
5800 * convert the kernel into a raw binary image:
5802 ${CROSS_COMPILE}-objcopy -O binary \
5803 -R .note -R .comment \
5804 -S vmlinux linux.bin
5806 * compress the binary image:
5810 * package compressed binary image for U-Boot:
5812 mkimage -A ppc -O linux -T kernel -C gzip \
5813 -a 0 -e 0 -n "Linux Kernel Image" \
5814 -d linux.bin.gz uImage
5817 The "mkimage" tool can also be used to create ramdisk images for use
5818 with U-Boot, either separated from the Linux kernel image, or
5819 combined into one file. "mkimage" encapsulates the images with a 64
5820 byte header containing information about target architecture,
5821 operating system, image type, compression method, entry points, time
5822 stamp, CRC32 checksums, etc.
5824 "mkimage" can be called in two ways: to verify existing images and
5825 print the header information, or to build new images.
5827 In the first form (with "-l" option) mkimage lists the information
5828 contained in the header of an existing U-Boot image; this includes
5829 checksum verification:
5831 tools/mkimage -l image
5832 -l ==> list image header information
5834 The second form (with "-d" option) is used to build a U-Boot image
5835 from a "data file" which is used as image payload:
5837 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5838 -n name -d data_file image
5839 -A ==> set architecture to 'arch'
5840 -O ==> set operating system to 'os'
5841 -T ==> set image type to 'type'
5842 -C ==> set compression type 'comp'
5843 -a ==> set load address to 'addr' (hex)
5844 -e ==> set entry point to 'ep' (hex)
5845 -n ==> set image name to 'name'
5846 -d ==> use image data from 'datafile'
5848 Right now, all Linux kernels for PowerPC systems use the same load
5849 address (0x00000000), but the entry point address depends on the
5852 - 2.2.x kernels have the entry point at 0x0000000C,
5853 - 2.3.x and later kernels have the entry point at 0x00000000.
5855 So a typical call to build a U-Boot image would read:
5857 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5858 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5859 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5860 > examples/uImage.TQM850L
5861 Image Name: 2.4.4 kernel for TQM850L
5862 Created: Wed Jul 19 02:34:59 2000
5863 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5864 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5865 Load Address: 0x00000000
5866 Entry Point: 0x00000000
5868 To verify the contents of the image (or check for corruption):
5870 -> tools/mkimage -l examples/uImage.TQM850L
5871 Image Name: 2.4.4 kernel for TQM850L
5872 Created: Wed Jul 19 02:34:59 2000
5873 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5874 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5875 Load Address: 0x00000000
5876 Entry Point: 0x00000000
5878 NOTE: for embedded systems where boot time is critical you can trade
5879 speed for memory and install an UNCOMPRESSED image instead: this
5880 needs more space in Flash, but boots much faster since it does not
5881 need to be uncompressed:
5883 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5884 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5885 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5886 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5887 > examples/uImage.TQM850L-uncompressed
5888 Image Name: 2.4.4 kernel for TQM850L
5889 Created: Wed Jul 19 02:34:59 2000
5890 Image Type: PowerPC Linux Kernel Image (uncompressed)
5891 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5892 Load Address: 0x00000000
5893 Entry Point: 0x00000000
5896 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5897 when your kernel is intended to use an initial ramdisk:
5899 -> tools/mkimage -n 'Simple Ramdisk Image' \
5900 > -A ppc -O linux -T ramdisk -C gzip \
5901 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5902 Image Name: Simple Ramdisk Image
5903 Created: Wed Jan 12 14:01:50 2000
5904 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5905 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5906 Load Address: 0x00000000
5907 Entry Point: 0x00000000
5909 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5910 option performs the converse operation of the mkimage's second form (the "-d"
5911 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5914 tools/dumpimage -i image -p position data_file
5915 -i ==> extract from the 'image' a specific 'data_file', \
5916 indexed by 'position'
5919 Installing a Linux Image:
5920 -------------------------
5922 To downloading a U-Boot image over the serial (console) interface,
5923 you must convert the image to S-Record format:
5925 objcopy -I binary -O srec examples/image examples/image.srec
5927 The 'objcopy' does not understand the information in the U-Boot
5928 image header, so the resulting S-Record file will be relative to
5929 address 0x00000000. To load it to a given address, you need to
5930 specify the target address as 'offset' parameter with the 'loads'
5933 Example: install the image to address 0x40100000 (which on the
5934 TQM8xxL is in the first Flash bank):
5936 => erase 40100000 401FFFFF
5942 ## Ready for S-Record download ...
5943 ~>examples/image.srec
5944 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5946 15989 15990 15991 15992
5947 [file transfer complete]
5949 ## Start Addr = 0x00000000
5952 You can check the success of the download using the 'iminfo' command;
5953 this includes a checksum verification so you can be sure no data
5954 corruption happened:
5958 ## Checking Image at 40100000 ...
5959 Image Name: 2.2.13 for initrd on TQM850L
5960 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5961 Data Size: 335725 Bytes = 327 kB = 0 MB
5962 Load Address: 00000000
5963 Entry Point: 0000000c
5964 Verifying Checksum ... OK
5970 The "bootm" command is used to boot an application that is stored in
5971 memory (RAM or Flash). In case of a Linux kernel image, the contents
5972 of the "bootargs" environment variable is passed to the kernel as
5973 parameters. You can check and modify this variable using the
5974 "printenv" and "setenv" commands:
5977 => printenv bootargs
5978 bootargs=root=/dev/ram
5980 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5982 => printenv bootargs
5983 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5986 ## Booting Linux kernel at 40020000 ...
5987 Image Name: 2.2.13 for NFS on TQM850L
5988 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5989 Data Size: 381681 Bytes = 372 kB = 0 MB
5990 Load Address: 00000000
5991 Entry Point: 0000000c
5992 Verifying Checksum ... OK
5993 Uncompressing Kernel Image ... OK
5994 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
5995 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5996 time_init: decrementer frequency = 187500000/60
5997 Calibrating delay loop... 49.77 BogoMIPS
5998 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
6001 If you want to boot a Linux kernel with initial RAM disk, you pass
6002 the memory addresses of both the kernel and the initrd image (PPBCOOT
6003 format!) to the "bootm" command:
6005 => imi 40100000 40200000
6007 ## Checking Image at 40100000 ...
6008 Image Name: 2.2.13 for initrd on TQM850L
6009 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6010 Data Size: 335725 Bytes = 327 kB = 0 MB
6011 Load Address: 00000000
6012 Entry Point: 0000000c
6013 Verifying Checksum ... OK
6015 ## Checking Image at 40200000 ...
6016 Image Name: Simple Ramdisk Image
6017 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6018 Data Size: 566530 Bytes = 553 kB = 0 MB
6019 Load Address: 00000000
6020 Entry Point: 00000000
6021 Verifying Checksum ... OK
6023 => bootm 40100000 40200000
6024 ## Booting Linux kernel at 40100000 ...
6025 Image Name: 2.2.13 for initrd on TQM850L
6026 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6027 Data Size: 335725 Bytes = 327 kB = 0 MB
6028 Load Address: 00000000
6029 Entry Point: 0000000c
6030 Verifying Checksum ... OK
6031 Uncompressing Kernel Image ... OK
6032 ## Loading RAMDisk Image at 40200000 ...
6033 Image Name: Simple Ramdisk Image
6034 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6035 Data Size: 566530 Bytes = 553 kB = 0 MB
6036 Load Address: 00000000
6037 Entry Point: 00000000
6038 Verifying Checksum ... OK
6039 Loading Ramdisk ... OK
6040 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
6041 Boot arguments: root=/dev/ram
6042 time_init: decrementer frequency = 187500000/60
6043 Calibrating delay loop... 49.77 BogoMIPS
6045 RAMDISK: Compressed image found at block 0
6046 VFS: Mounted root (ext2 filesystem).
6050 Boot Linux and pass a flat device tree:
6053 First, U-Boot must be compiled with the appropriate defines. See the section
6054 titled "Linux Kernel Interface" above for a more in depth explanation. The
6055 following is an example of how to start a kernel and pass an updated
6061 oft=oftrees/mpc8540ads.dtb
6062 => tftp $oftaddr $oft
6063 Speed: 1000, full duplex
6065 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6066 Filename 'oftrees/mpc8540ads.dtb'.
6067 Load address: 0x300000
6070 Bytes transferred = 4106 (100a hex)
6071 => tftp $loadaddr $bootfile
6072 Speed: 1000, full duplex
6074 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6076 Load address: 0x200000
6077 Loading:############
6079 Bytes transferred = 1029407 (fb51f hex)
6084 => bootm $loadaddr - $oftaddr
6085 ## Booting image at 00200000 ...
6086 Image Name: Linux-2.6.17-dirty
6087 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6088 Data Size: 1029343 Bytes = 1005.2 kB
6089 Load Address: 00000000
6090 Entry Point: 00000000
6091 Verifying Checksum ... OK
6092 Uncompressing Kernel Image ... OK
6093 Booting using flat device tree at 0x300000
6094 Using MPC85xx ADS machine description
6095 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6099 More About U-Boot Image Types:
6100 ------------------------------
6102 U-Boot supports the following image types:
6104 "Standalone Programs" are directly runnable in the environment
6105 provided by U-Boot; it is expected that (if they behave
6106 well) you can continue to work in U-Boot after return from
6107 the Standalone Program.
6108 "OS Kernel Images" are usually images of some Embedded OS which
6109 will take over control completely. Usually these programs
6110 will install their own set of exception handlers, device
6111 drivers, set up the MMU, etc. - this means, that you cannot
6112 expect to re-enter U-Boot except by resetting the CPU.
6113 "RAMDisk Images" are more or less just data blocks, and their
6114 parameters (address, size) are passed to an OS kernel that is
6116 "Multi-File Images" contain several images, typically an OS
6117 (Linux) kernel image and one or more data images like
6118 RAMDisks. This construct is useful for instance when you want
6119 to boot over the network using BOOTP etc., where the boot
6120 server provides just a single image file, but you want to get
6121 for instance an OS kernel and a RAMDisk image.
6123 "Multi-File Images" start with a list of image sizes, each
6124 image size (in bytes) specified by an "uint32_t" in network
6125 byte order. This list is terminated by an "(uint32_t)0".
6126 Immediately after the terminating 0 follow the images, one by
6127 one, all aligned on "uint32_t" boundaries (size rounded up to
6128 a multiple of 4 bytes).
6130 "Firmware Images" are binary images containing firmware (like
6131 U-Boot or FPGA images) which usually will be programmed to
6134 "Script files" are command sequences that will be executed by
6135 U-Boot's command interpreter; this feature is especially
6136 useful when you configure U-Boot to use a real shell (hush)
6137 as command interpreter.
6139 Booting the Linux zImage:
6140 -------------------------
6142 On some platforms, it's possible to boot Linux zImage. This is done
6143 using the "bootz" command. The syntax of "bootz" command is the same
6144 as the syntax of "bootm" command.
6146 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6147 kernel with raw initrd images. The syntax is slightly different, the
6148 address of the initrd must be augmented by it's size, in the following
6149 format: "<initrd addres>:<initrd size>".
6155 One of the features of U-Boot is that you can dynamically load and
6156 run "standalone" applications, which can use some resources of
6157 U-Boot like console I/O functions or interrupt services.
6159 Two simple examples are included with the sources:
6164 'examples/hello_world.c' contains a small "Hello World" Demo
6165 application; it is automatically compiled when you build U-Boot.
6166 It's configured to run at address 0x00040004, so you can play with it
6170 ## Ready for S-Record download ...
6171 ~>examples/hello_world.srec
6172 1 2 3 4 5 6 7 8 9 10 11 ...
6173 [file transfer complete]
6175 ## Start Addr = 0x00040004
6177 => go 40004 Hello World! This is a test.
6178 ## Starting application at 0x00040004 ...
6189 Hit any key to exit ...
6191 ## Application terminated, rc = 0x0
6193 Another example, which demonstrates how to register a CPM interrupt
6194 handler with the U-Boot code, can be found in 'examples/timer.c'.
6195 Here, a CPM timer is set up to generate an interrupt every second.
6196 The interrupt service routine is trivial, just printing a '.'
6197 character, but this is just a demo program. The application can be
6198 controlled by the following keys:
6200 ? - print current values og the CPM Timer registers
6201 b - enable interrupts and start timer
6202 e - stop timer and disable interrupts
6203 q - quit application
6206 ## Ready for S-Record download ...
6207 ~>examples/timer.srec
6208 1 2 3 4 5 6 7 8 9 10 11 ...
6209 [file transfer complete]
6211 ## Start Addr = 0x00040004
6214 ## Starting application at 0x00040004 ...
6217 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6220 [q, b, e, ?] Set interval 1000000 us
6223 [q, b, e, ?] ........
6224 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6227 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6230 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6233 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6235 [q, b, e, ?] ...Stopping timer
6237 [q, b, e, ?] ## Application terminated, rc = 0x0
6243 Over time, many people have reported problems when trying to use the
6244 "minicom" terminal emulation program for serial download. I (wd)
6245 consider minicom to be broken, and recommend not to use it. Under
6246 Unix, I recommend to use C-Kermit for general purpose use (and
6247 especially for kermit binary protocol download ("loadb" command), and
6248 use "cu" for S-Record download ("loads" command). See
6249 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6250 for help with kermit.
6253 Nevertheless, if you absolutely want to use it try adding this
6254 configuration to your "File transfer protocols" section:
6256 Name Program Name U/D FullScr IO-Red. Multi
6257 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6258 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6264 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6265 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6267 Building requires a cross environment; it is known to work on
6268 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6269 need gmake since the Makefiles are not compatible with BSD make).
6270 Note that the cross-powerpc package does not install include files;
6271 attempting to build U-Boot will fail because <machine/ansi.h> is
6272 missing. This file has to be installed and patched manually:
6274 # cd /usr/pkg/cross/powerpc-netbsd/include
6276 # ln -s powerpc machine
6277 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6278 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6280 Native builds *don't* work due to incompatibilities between native
6281 and U-Boot include files.
6283 Booting assumes that (the first part of) the image booted is a
6284 stage-2 loader which in turn loads and then invokes the kernel
6285 proper. Loader sources will eventually appear in the NetBSD source
6286 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6287 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6290 Implementation Internals:
6291 =========================
6293 The following is not intended to be a complete description of every
6294 implementation detail. However, it should help to understand the
6295 inner workings of U-Boot and make it easier to port it to custom
6299 Initial Stack, Global Data:
6300 ---------------------------
6302 The implementation of U-Boot is complicated by the fact that U-Boot
6303 starts running out of ROM (flash memory), usually without access to
6304 system RAM (because the memory controller is not initialized yet).
6305 This means that we don't have writable Data or BSS segments, and BSS
6306 is not initialized as zero. To be able to get a C environment working
6307 at all, we have to allocate at least a minimal stack. Implementation
6308 options for this are defined and restricted by the CPU used: Some CPU
6309 models provide on-chip memory (like the IMMR area on MPC8xx and
6310 MPC826x processors), on others (parts of) the data cache can be
6311 locked as (mis-) used as memory, etc.
6313 Chris Hallinan posted a good summary of these issues to the
6314 U-Boot mailing list:
6316 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6317 From: "Chris Hallinan" <clh@net1plus.com>
6318 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6321 Correct me if I'm wrong, folks, but the way I understand it
6322 is this: Using DCACHE as initial RAM for Stack, etc, does not
6323 require any physical RAM backing up the cache. The cleverness
6324 is that the cache is being used as a temporary supply of
6325 necessary storage before the SDRAM controller is setup. It's
6326 beyond the scope of this list to explain the details, but you
6327 can see how this works by studying the cache architecture and
6328 operation in the architecture and processor-specific manuals.
6330 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6331 is another option for the system designer to use as an
6332 initial stack/RAM area prior to SDRAM being available. Either
6333 option should work for you. Using CS 4 should be fine if your
6334 board designers haven't used it for something that would
6335 cause you grief during the initial boot! It is frequently not
6338 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6339 with your processor/board/system design. The default value
6340 you will find in any recent u-boot distribution in
6341 walnut.h should work for you. I'd set it to a value larger
6342 than your SDRAM module. If you have a 64MB SDRAM module, set
6343 it above 400_0000. Just make sure your board has no resources
6344 that are supposed to respond to that address! That code in
6345 start.S has been around a while and should work as is when
6346 you get the config right.
6351 It is essential to remember this, since it has some impact on the C
6352 code for the initialization procedures:
6354 * Initialized global data (data segment) is read-only. Do not attempt
6357 * Do not use any uninitialized global data (or implicitly initialized
6358 as zero data - BSS segment) at all - this is undefined, initiali-
6359 zation is performed later (when relocating to RAM).
6361 * Stack space is very limited. Avoid big data buffers or things like
6364 Having only the stack as writable memory limits means we cannot use
6365 normal global data to share information between the code. But it
6366 turned out that the implementation of U-Boot can be greatly
6367 simplified by making a global data structure (gd_t) available to all
6368 functions. We could pass a pointer to this data as argument to _all_
6369 functions, but this would bloat the code. Instead we use a feature of
6370 the GCC compiler (Global Register Variables) to share the data: we
6371 place a pointer (gd) to the global data into a register which we
6372 reserve for this purpose.
6374 When choosing a register for such a purpose we are restricted by the
6375 relevant (E)ABI specifications for the current architecture, and by
6376 GCC's implementation.
6378 For PowerPC, the following registers have specific use:
6380 R2: reserved for system use
6381 R3-R4: parameter passing and return values
6382 R5-R10: parameter passing
6383 R13: small data area pointer
6387 (U-Boot also uses R12 as internal GOT pointer. r12
6388 is a volatile register so r12 needs to be reset when
6389 going back and forth between asm and C)
6391 ==> U-Boot will use R2 to hold a pointer to the global data
6393 Note: on PPC, we could use a static initializer (since the
6394 address of the global data structure is known at compile time),
6395 but it turned out that reserving a register results in somewhat
6396 smaller code - although the code savings are not that big (on
6397 average for all boards 752 bytes for the whole U-Boot image,
6398 624 text + 127 data).
6400 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6401 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6403 ==> U-Boot will use P3 to hold a pointer to the global data
6405 On ARM, the following registers are used:
6407 R0: function argument word/integer result
6408 R1-R3: function argument word
6409 R9: platform specific
6410 R10: stack limit (used only if stack checking is enabled)
6411 R11: argument (frame) pointer
6412 R12: temporary workspace
6415 R15: program counter
6417 ==> U-Boot will use R9 to hold a pointer to the global data
6419 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6421 On Nios II, the ABI is documented here:
6422 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6424 ==> U-Boot will use gp to hold a pointer to the global data
6426 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6427 to access small data sections, so gp is free.
6429 On NDS32, the following registers are used:
6431 R0-R1: argument/return
6433 R15: temporary register for assembler
6434 R16: trampoline register
6435 R28: frame pointer (FP)
6436 R29: global pointer (GP)
6437 R30: link register (LP)
6438 R31: stack pointer (SP)
6439 PC: program counter (PC)
6441 ==> U-Boot will use R10 to hold a pointer to the global data
6443 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6444 or current versions of GCC may "optimize" the code too much.
6449 U-Boot runs in system state and uses physical addresses, i.e. the
6450 MMU is not used either for address mapping nor for memory protection.
6452 The available memory is mapped to fixed addresses using the memory
6453 controller. In this process, a contiguous block is formed for each
6454 memory type (Flash, SDRAM, SRAM), even when it consists of several
6455 physical memory banks.
6457 U-Boot is installed in the first 128 kB of the first Flash bank (on
6458 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6459 booting and sizing and initializing DRAM, the code relocates itself
6460 to the upper end of DRAM. Immediately below the U-Boot code some
6461 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6462 configuration setting]. Below that, a structure with global Board
6463 Info data is placed, followed by the stack (growing downward).
6465 Additionally, some exception handler code is copied to the low 8 kB
6466 of DRAM (0x00000000 ... 0x00001FFF).
6468 So a typical memory configuration with 16 MB of DRAM could look like
6471 0x0000 0000 Exception Vector code
6474 0x0000 2000 Free for Application Use
6480 0x00FB FF20 Monitor Stack (Growing downward)
6481 0x00FB FFAC Board Info Data and permanent copy of global data
6482 0x00FC 0000 Malloc Arena
6485 0x00FE 0000 RAM Copy of Monitor Code
6486 ... eventually: LCD or video framebuffer
6487 ... eventually: pRAM (Protected RAM - unchanged by reset)
6488 0x00FF FFFF [End of RAM]
6491 System Initialization:
6492 ----------------------
6494 In the reset configuration, U-Boot starts at the reset entry point
6495 (on most PowerPC systems at address 0x00000100). Because of the reset
6496 configuration for CS0# this is a mirror of the on board Flash memory.
6497 To be able to re-map memory U-Boot then jumps to its link address.
6498 To be able to implement the initialization code in C, a (small!)
6499 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6500 which provide such a feature like MPC8xx or MPC8260), or in a locked
6501 part of the data cache. After that, U-Boot initializes the CPU core,
6502 the caches and the SIU.
6504 Next, all (potentially) available memory banks are mapped using a
6505 preliminary mapping. For example, we put them on 512 MB boundaries
6506 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6507 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6508 programmed for SDRAM access. Using the temporary configuration, a
6509 simple memory test is run that determines the size of the SDRAM
6512 When there is more than one SDRAM bank, and the banks are of
6513 different size, the largest is mapped first. For equal size, the first
6514 bank (CS2#) is mapped first. The first mapping is always for address
6515 0x00000000, with any additional banks following immediately to create
6516 contiguous memory starting from 0.
6518 Then, the monitor installs itself at the upper end of the SDRAM area
6519 and allocates memory for use by malloc() and for the global Board
6520 Info data; also, the exception vector code is copied to the low RAM
6521 pages, and the final stack is set up.
6523 Only after this relocation will you have a "normal" C environment;
6524 until that you are restricted in several ways, mostly because you are
6525 running from ROM, and because the code will have to be relocated to a
6529 U-Boot Porting Guide:
6530 ----------------------
6532 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6536 int main(int argc, char *argv[])
6538 sighandler_t no_more_time;
6540 signal(SIGALRM, no_more_time);
6541 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6543 if (available_money > available_manpower) {
6544 Pay consultant to port U-Boot;
6548 Download latest U-Boot source;
6550 Subscribe to u-boot mailing list;
6553 email("Hi, I am new to U-Boot, how do I get started?");
6556 Read the README file in the top level directory;
6557 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6558 Read applicable doc/*.README;
6559 Read the source, Luke;
6560 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6563 if (available_money > toLocalCurrency ($2500))
6566 Add a lot of aggravation and time;
6568 if (a similar board exists) { /* hopefully... */
6569 cp -a board/<similar> board/<myboard>
6570 cp include/configs/<similar>.h include/configs/<myboard>.h
6572 Create your own board support subdirectory;
6573 Create your own board include/configs/<myboard>.h file;
6575 Edit new board/<myboard> files
6576 Edit new include/configs/<myboard>.h
6581 Add / modify source code;
6585 email("Hi, I am having problems...");
6587 Send patch file to the U-Boot email list;
6588 if (reasonable critiques)
6589 Incorporate improvements from email list code review;
6591 Defend code as written;
6597 void no_more_time (int sig)
6606 All contributions to U-Boot should conform to the Linux kernel
6607 coding style; see the file "Documentation/CodingStyle" and the script
6608 "scripts/Lindent" in your Linux kernel source directory.
6610 Source files originating from a different project (for example the
6611 MTD subsystem) are generally exempt from these guidelines and are not
6612 reformatted to ease subsequent migration to newer versions of those
6615 Please note that U-Boot is implemented in C (and to some small parts in
6616 Assembler); no C++ is used, so please do not use C++ style comments (//)
6619 Please also stick to the following formatting rules:
6620 - remove any trailing white space
6621 - use TAB characters for indentation and vertical alignment, not spaces
6622 - make sure NOT to use DOS '\r\n' line feeds
6623 - do not add more than 2 consecutive empty lines to source files
6624 - do not add trailing empty lines to source files
6626 Submissions which do not conform to the standards may be returned
6627 with a request to reformat the changes.
6633 Since the number of patches for U-Boot is growing, we need to
6634 establish some rules. Submissions which do not conform to these rules
6635 may be rejected, even when they contain important and valuable stuff.
6637 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6639 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6640 see http://lists.denx.de/mailman/listinfo/u-boot
6642 When you send a patch, please include the following information with
6645 * For bug fixes: a description of the bug and how your patch fixes
6646 this bug. Please try to include a way of demonstrating that the
6647 patch actually fixes something.
6649 * For new features: a description of the feature and your
6652 * A CHANGELOG entry as plaintext (separate from the patch)
6654 * For major contributions, your entry to the CREDITS file
6656 * When you add support for a new board, don't forget to add a
6657 maintainer e-mail address to the boards.cfg file, too.
6659 * If your patch adds new configuration options, don't forget to
6660 document these in the README file.
6662 * The patch itself. If you are using git (which is *strongly*
6663 recommended) you can easily generate the patch using the
6664 "git format-patch". If you then use "git send-email" to send it to
6665 the U-Boot mailing list, you will avoid most of the common problems
6666 with some other mail clients.
6668 If you cannot use git, use "diff -purN OLD NEW". If your version of
6669 diff does not support these options, then get the latest version of
6672 The current directory when running this command shall be the parent
6673 directory of the U-Boot source tree (i. e. please make sure that
6674 your patch includes sufficient directory information for the
6677 We prefer patches as plain text. MIME attachments are discouraged,
6678 and compressed attachments must not be used.
6680 * If one logical set of modifications affects or creates several
6681 files, all these changes shall be submitted in a SINGLE patch file.
6683 * Changesets that contain different, unrelated modifications shall be
6684 submitted as SEPARATE patches, one patch per changeset.
6689 * Before sending the patch, run the MAKEALL script on your patched
6690 source tree and make sure that no errors or warnings are reported
6691 for any of the boards.
6693 * Keep your modifications to the necessary minimum: A patch
6694 containing several unrelated changes or arbitrary reformats will be
6695 returned with a request to re-formatting / split it.
6697 * If you modify existing code, make sure that your new code does not
6698 add to the memory footprint of the code ;-) Small is beautiful!
6699 When adding new features, these should compile conditionally only
6700 (using #ifdef), and the resulting code with the new feature
6701 disabled must not need more memory than the old code without your
6704 * Remember that there is a size limit of 100 kB per message on the
6705 u-boot mailing list. Bigger patches will be moderated. If they are
6706 reasonable and not too big, they will be acknowledged. But patches
6707 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob