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 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
542 Number of controllers used as main memory.
544 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
545 Number of controllers used for other than main memory.
547 CONFIG_SYS_FSL_SEC_BE
548 Defines the SEC controller register space as Big Endian
550 CONFIG_SYS_FSL_SEC_LE
551 Defines the SEC controller register space as Little Endian
553 - Intel Monahans options:
554 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
556 Defines the Monahans run mode to oscillator
557 ratio. Valid values are 8, 16, 24, 31. The core
558 frequency is this value multiplied by 13 MHz.
560 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
562 Defines the Monahans turbo mode to oscillator
563 ratio. Valid values are 1 (default if undefined) and
564 2. The core frequency as calculated above is multiplied
568 CONFIG_SYS_INIT_SP_OFFSET
570 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
571 pointer. This is needed for the temporary stack before
574 CONFIG_SYS_MIPS_CACHE_MODE
576 Cache operation mode for the MIPS CPU.
577 See also arch/mips/include/asm/mipsregs.h.
579 CONF_CM_CACHABLE_NO_WA
582 CONF_CM_CACHABLE_NONCOHERENT
586 CONF_CM_CACHABLE_ACCELERATED
588 CONFIG_SYS_XWAY_EBU_BOOTCFG
590 Special option for Lantiq XWAY SoCs for booting from NOR flash.
591 See also arch/mips/cpu/mips32/start.S.
593 CONFIG_XWAY_SWAP_BYTES
595 Enable compilation of tools/xway-swap-bytes needed for Lantiq
596 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
597 be swapped if a flash programmer is used.
600 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
602 Select high exception vectors of the ARM core, e.g., do not
603 clear the V bit of the c1 register of CP15.
605 CONFIG_SYS_THUMB_BUILD
607 Use this flag to build U-Boot using the Thumb instruction
608 set for ARM architectures. Thumb instruction set provides
609 better code density. For ARM architectures that support
610 Thumb2 this flag will result in Thumb2 code generated by
613 CONFIG_ARM_ERRATA_716044
614 CONFIG_ARM_ERRATA_742230
615 CONFIG_ARM_ERRATA_743622
616 CONFIG_ARM_ERRATA_751472
617 CONFIG_ARM_ERRATA_794072
618 CONFIG_ARM_ERRATA_761320
620 If set, the workarounds for these ARM errata are applied early
621 during U-Boot startup. Note that these options force the
622 workarounds to be applied; no CPU-type/version detection
623 exists, unlike the similar options in the Linux kernel. Do not
624 set these options unless they apply!
627 Driver model is a new framework for devices in U-Boot
628 introduced in early 2014. U-Boot is being progressively
629 moved over to this. It offers a consistent device structure,
630 supports grouping devices into classes and has built-in
631 handling of platform data and device tree.
633 To enable transition to driver model in a relatively
634 painful fashion, each subsystem can be independently
635 switched between the legacy/ad-hoc approach and the new
636 driver model using the options below. Also, many uclass
637 interfaces include compatibility features which may be
638 removed once the conversion of that subsystem is complete.
639 As a result, the API provided by the subsystem may in fact
640 not change with driver model.
642 See doc/driver-model/README.txt for more information.
646 Enable driver model. This brings in the core support,
647 including scanning of platform data on start-up. If
648 CONFIG_OF_CONTROL is enabled, the device tree will be
649 scanned also when available.
653 Enable driver model test commands. These allow you to print
654 out the driver model tree and the uclasses.
658 Enable some demo devices and the 'demo' command. These are
659 really only useful for playing around while trying to
660 understand driver model in sandbox.
664 Enable driver model in SPL. You will need to provide a
665 suitable malloc() implementation. If you are not using the
666 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
667 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
668 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
669 In most cases driver model will only allocate a few uclasses
670 and devices in SPL, so 1KB should be enable. See
671 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
676 Enable driver model for serial. This replaces
677 drivers/serial/serial.c with the serial uclass, which
678 implements serial_putc() etc. The uclass interface is
679 defined in include/serial.h.
683 Enable driver model for GPIO access. The standard GPIO
684 interface (gpio_get_value(), etc.) is then implemented by
685 the GPIO uclass. Drivers provide methods to query the
686 particular GPIOs that they provide. The uclass interface
687 is defined in include/asm-generic/gpio.h.
691 Enable driver model for SPI. The SPI slave interface
692 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
693 the SPI uclass. Drivers provide methods to access the SPI
694 buses that they control. The uclass interface is defined in
695 include/spi.h. The existing spi_slave structure is attached
696 as 'parent data' to every slave on each bus. Slaves
697 typically use driver-private data instead of extending the
702 Enable driver model for SPI flash. This SPI flash interface
703 (spi_flash_probe(), spi_flash_write(), etc.) is then
704 implemented by the SPI flash uclass. There is one standard
705 SPI flash driver which knows how to probe most chips
706 supported by U-Boot. The uclass interface is defined in
707 include/spi_flash.h, but is currently fully compatible
708 with the old interface to avoid confusion and duplication
709 during the transition parent. SPI and SPI flash must be
710 enabled together (it is not possible to use driver model
711 for one and not the other).
715 Enable driver model for the Chrome OS EC interface. This
716 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
717 but otherwise makes few changes. Since cros_ec also supports
718 I2C and LPC (which don't support driver model yet), a full
719 conversion is not yet possible.
722 ** Code size options: The following options are enabled by
723 default except in SPL. Enable them explicitly to get these
728 Enable the dm_warn() function. This can use up quite a bit
729 of space for its strings.
733 Enable registering a serial device with the stdio library.
735 CONFIG_DM_DEVICE_REMOVE
737 Enable removing of devices.
740 - Linux Kernel Interface:
743 U-Boot stores all clock information in Hz
744 internally. For binary compatibility with older Linux
745 kernels (which expect the clocks passed in the
746 bd_info data to be in MHz) the environment variable
747 "clocks_in_mhz" can be defined so that U-Boot
748 converts clock data to MHZ before passing it to the
750 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
751 "clocks_in_mhz=1" is automatically included in the
754 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
756 When transferring memsize parameter to linux, some versions
757 expect it to be in bytes, others in MB.
758 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
762 New kernel versions are expecting firmware settings to be
763 passed using flattened device trees (based on open firmware
767 * New libfdt-based support
768 * Adds the "fdt" command
769 * The bootm command automatically updates the fdt
771 OF_CPU - The proper name of the cpus node (only required for
772 MPC512X and MPC5xxx based boards).
773 OF_SOC - The proper name of the soc node (only required for
774 MPC512X and MPC5xxx based boards).
775 OF_TBCLK - The timebase frequency.
776 OF_STDOUT_PATH - The path to the console device
778 boards with QUICC Engines require OF_QE to set UCC MAC
781 CONFIG_OF_BOARD_SETUP
783 Board code has addition modification that it wants to make
784 to the flat device tree before handing it off to the kernel
788 This define fills in the correct boot CPU in the boot
789 param header, the default value is zero if undefined.
793 U-Boot can detect if an IDE device is present or not.
794 If not, and this new config option is activated, U-Boot
795 removes the ATA node from the DTS before booting Linux,
796 so the Linux IDE driver does not probe the device and
797 crash. This is needed for buggy hardware (uc101) where
798 no pull down resistor is connected to the signal IDE5V_DD7.
800 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
802 This setting is mandatory for all boards that have only one
803 machine type and must be used to specify the machine type
804 number as it appears in the ARM machine registry
805 (see http://www.arm.linux.org.uk/developer/machines/).
806 Only boards that have multiple machine types supported
807 in a single configuration file and the machine type is
808 runtime discoverable, do not have to use this setting.
810 - vxWorks boot parameters:
812 bootvx constructs a valid bootline using the following
813 environments variables: bootfile, ipaddr, serverip, hostname.
814 It loads the vxWorks image pointed bootfile.
816 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
817 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
818 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
819 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
821 CONFIG_SYS_VXWORKS_ADD_PARAMS
823 Add it at the end of the bootline. E.g "u=username pw=secret"
825 Note: If a "bootargs" environment is defined, it will overwride
826 the defaults discussed just above.
828 - Cache Configuration:
829 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
830 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
831 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
833 - Cache Configuration for ARM:
834 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
836 CONFIG_SYS_PL310_BASE - Physical base address of PL310
837 controller register space
842 Define this if you want support for Amba PrimeCell PL010 UARTs.
846 Define this if you want support for Amba PrimeCell PL011 UARTs.
850 If you have Amba PrimeCell PL011 UARTs, set this variable to
851 the clock speed of the UARTs.
855 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
856 define this to a list of base addresses for each (supported)
857 port. See e.g. include/configs/versatile.h
859 CONFIG_PL011_SERIAL_RLCR
861 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
862 have separate receive and transmit line control registers. Set
863 this variable to initialize the extra register.
865 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
867 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
868 boot loader that has already initialized the UART. Define this
869 variable to flush the UART at init time.
871 CONFIG_SERIAL_HW_FLOW_CONTROL
873 Define this variable to enable hw flow control in serial driver.
874 Current user of this option is drivers/serial/nsl16550.c driver
877 Depending on board, define exactly one serial port
878 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
879 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
880 console by defining CONFIG_8xx_CONS_NONE
882 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
883 port routines must be defined elsewhere
884 (i.e. serial_init(), serial_getc(), ...)
887 Enables console device for a color framebuffer. Needs following
888 defines (cf. smiLynxEM, i8042)
889 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
891 VIDEO_HW_RECTFILL graphic chip supports
894 VIDEO_HW_BITBLT graphic chip supports
895 bit-blit (cf. smiLynxEM)
896 VIDEO_VISIBLE_COLS visible pixel columns
898 VIDEO_VISIBLE_ROWS visible pixel rows
899 VIDEO_PIXEL_SIZE bytes per pixel
900 VIDEO_DATA_FORMAT graphic data format
901 (0-5, cf. cfb_console.c)
902 VIDEO_FB_ADRS framebuffer address
903 VIDEO_KBD_INIT_FCT keyboard int fct
904 (i.e. i8042_kbd_init())
905 VIDEO_TSTC_FCT test char fct
907 VIDEO_GETC_FCT get char fct
909 CONFIG_CONSOLE_CURSOR cursor drawing on/off
910 (requires blink timer
912 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
913 CONFIG_CONSOLE_TIME display time/date info in
915 (requires CONFIG_CMD_DATE)
916 CONFIG_VIDEO_LOGO display Linux logo in
918 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
919 linux_logo.h for logo.
920 Requires CONFIG_VIDEO_LOGO
921 CONFIG_CONSOLE_EXTRA_INFO
922 additional board info beside
925 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
926 a limited number of ANSI escape sequences (cursor control,
927 erase functions and limited graphics rendition control).
929 When CONFIG_CFB_CONSOLE is defined, video console is
930 default i/o. Serial console can be forced with
931 environment 'console=serial'.
933 When CONFIG_SILENT_CONSOLE is defined, all console
934 messages (by U-Boot and Linux!) can be silenced with
935 the "silent" environment variable. See
936 doc/README.silent for more information.
938 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
940 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
944 CONFIG_BAUDRATE - in bps
945 Select one of the baudrates listed in
946 CONFIG_SYS_BAUDRATE_TABLE, see below.
947 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
949 - Console Rx buffer length
950 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
951 the maximum receive buffer length for the SMC.
952 This option is actual only for 82xx and 8xx possible.
953 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
954 must be defined, to setup the maximum idle timeout for
957 - Pre-Console Buffer:
958 Prior to the console being initialised (i.e. serial UART
959 initialised etc) all console output is silently discarded.
960 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
961 buffer any console messages prior to the console being
962 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
963 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
964 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
965 bytes are output before the console is initialised, the
966 earlier bytes are discarded.
968 'Sane' compilers will generate smaller code if
969 CONFIG_PRE_CON_BUF_SZ is a power of 2
971 - Safe printf() functions
972 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
973 the printf() functions. These are defined in
974 include/vsprintf.h and include snprintf(), vsnprintf() and
975 so on. Code size increase is approximately 300-500 bytes.
976 If this option is not given then these functions will
977 silently discard their buffer size argument - this means
978 you are not getting any overflow checking in this case.
980 - Boot Delay: CONFIG_BOOTDELAY - in seconds
981 Delay before automatically booting the default image;
982 set to -1 to disable autoboot.
983 set to -2 to autoboot with no delay and not check for abort
984 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
986 See doc/README.autoboot for these options that
987 work with CONFIG_BOOTDELAY. None are required.
988 CONFIG_BOOT_RETRY_TIME
989 CONFIG_BOOT_RETRY_MIN
990 CONFIG_AUTOBOOT_KEYED
991 CONFIG_AUTOBOOT_PROMPT
992 CONFIG_AUTOBOOT_DELAY_STR
993 CONFIG_AUTOBOOT_STOP_STR
994 CONFIG_AUTOBOOT_DELAY_STR2
995 CONFIG_AUTOBOOT_STOP_STR2
996 CONFIG_ZERO_BOOTDELAY_CHECK
997 CONFIG_RESET_TO_RETRY
1001 Only needed when CONFIG_BOOTDELAY is enabled;
1002 define a command string that is automatically executed
1003 when no character is read on the console interface
1004 within "Boot Delay" after reset.
1007 This can be used to pass arguments to the bootm
1008 command. The value of CONFIG_BOOTARGS goes into the
1009 environment value "bootargs".
1011 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1012 The value of these goes into the environment as
1013 "ramboot" and "nfsboot" respectively, and can be used
1014 as a convenience, when switching between booting from
1018 CONFIG_BOOTCOUNT_LIMIT
1019 Implements a mechanism for detecting a repeating reboot
1021 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1023 CONFIG_BOOTCOUNT_ENV
1024 If no softreset save registers are found on the hardware
1025 "bootcount" is stored in the environment. To prevent a
1026 saveenv on all reboots, the environment variable
1027 "upgrade_available" is used. If "upgrade_available" is
1028 0, "bootcount" is always 0, if "upgrade_available" is
1029 1 "bootcount" is incremented in the environment.
1030 So the Userspace Applikation must set the "upgrade_available"
1031 and "bootcount" variable to 0, if a boot was successfully.
1033 - Pre-Boot Commands:
1036 When this option is #defined, the existence of the
1037 environment variable "preboot" will be checked
1038 immediately before starting the CONFIG_BOOTDELAY
1039 countdown and/or running the auto-boot command resp.
1040 entering interactive mode.
1042 This feature is especially useful when "preboot" is
1043 automatically generated or modified. For an example
1044 see the LWMON board specific code: here "preboot" is
1045 modified when the user holds down a certain
1046 combination of keys on the (special) keyboard when
1049 - Serial Download Echo Mode:
1051 If defined to 1, all characters received during a
1052 serial download (using the "loads" command) are
1053 echoed back. This might be needed by some terminal
1054 emulations (like "cu"), but may as well just take
1055 time on others. This setting #define's the initial
1056 value of the "loads_echo" environment variable.
1058 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1059 CONFIG_KGDB_BAUDRATE
1060 Select one of the baudrates listed in
1061 CONFIG_SYS_BAUDRATE_TABLE, see below.
1063 - Monitor Functions:
1064 Monitor commands can be included or excluded
1065 from the build by using the #include files
1066 <config_cmd_all.h> and #undef'ing unwanted
1067 commands, or using <config_cmd_default.h>
1068 and augmenting with additional #define's
1069 for wanted commands.
1071 The default command configuration includes all commands
1072 except those marked below with a "*".
1074 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1075 CONFIG_CMD_ASKENV * ask for env variable
1076 CONFIG_CMD_BDI bdinfo
1077 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1078 CONFIG_CMD_BMP * BMP support
1079 CONFIG_CMD_BSP * Board specific commands
1080 CONFIG_CMD_BOOTD bootd
1081 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1082 CONFIG_CMD_CACHE * icache, dcache
1083 CONFIG_CMD_CLK * clock command support
1084 CONFIG_CMD_CONSOLE coninfo
1085 CONFIG_CMD_CRC32 * crc32
1086 CONFIG_CMD_DATE * support for RTC, date/time...
1087 CONFIG_CMD_DHCP * DHCP support
1088 CONFIG_CMD_DIAG * Diagnostics
1089 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1090 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1091 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1092 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1093 CONFIG_CMD_DTT * Digital Therm and Thermostat
1094 CONFIG_CMD_ECHO echo arguments
1095 CONFIG_CMD_EDITENV edit env variable
1096 CONFIG_CMD_EEPROM * EEPROM read/write support
1097 CONFIG_CMD_ELF * bootelf, bootvx
1098 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1099 CONFIG_CMD_ENV_FLAGS * display details about env flags
1100 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1101 CONFIG_CMD_EXPORTENV * export the environment
1102 CONFIG_CMD_EXT2 * ext2 command support
1103 CONFIG_CMD_EXT4 * ext4 command support
1104 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1105 that work for multiple fs types
1106 CONFIG_CMD_SAVEENV saveenv
1107 CONFIG_CMD_FDC * Floppy Disk Support
1108 CONFIG_CMD_FAT * FAT command support
1109 CONFIG_CMD_FLASH flinfo, erase, protect
1110 CONFIG_CMD_FPGA FPGA device initialization support
1111 CONFIG_CMD_FUSE * Device fuse support
1112 CONFIG_CMD_GETTIME * Get time since boot
1113 CONFIG_CMD_GO * the 'go' command (exec code)
1114 CONFIG_CMD_GREPENV * search environment
1115 CONFIG_CMD_HASH * calculate hash / digest
1116 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1117 CONFIG_CMD_I2C * I2C serial bus support
1118 CONFIG_CMD_IDE * IDE harddisk support
1119 CONFIG_CMD_IMI iminfo
1120 CONFIG_CMD_IMLS List all images found in NOR flash
1121 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1122 CONFIG_CMD_IMMAP * IMMR dump support
1123 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1124 CONFIG_CMD_IMPORTENV * import an environment
1125 CONFIG_CMD_INI * import data from an ini file into the env
1126 CONFIG_CMD_IRQ * irqinfo
1127 CONFIG_CMD_ITEST Integer/string test of 2 values
1128 CONFIG_CMD_JFFS2 * JFFS2 Support
1129 CONFIG_CMD_KGDB * kgdb
1130 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1131 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1133 CONFIG_CMD_LOADB loadb
1134 CONFIG_CMD_LOADS loads
1135 CONFIG_CMD_MD5SUM * print md5 message digest
1136 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1137 CONFIG_CMD_MEMINFO * Display detailed memory information
1138 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1140 CONFIG_CMD_MEMTEST * mtest
1141 CONFIG_CMD_MISC Misc functions like sleep etc
1142 CONFIG_CMD_MMC * MMC memory mapped support
1143 CONFIG_CMD_MII * MII utility commands
1144 CONFIG_CMD_MTDPARTS * MTD partition support
1145 CONFIG_CMD_NAND * NAND support
1146 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1147 CONFIG_CMD_NFS NFS support
1148 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1149 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1150 CONFIG_CMD_PCI * pciinfo
1151 CONFIG_CMD_PCMCIA * PCMCIA support
1152 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1154 CONFIG_CMD_PORTIO * Port I/O
1155 CONFIG_CMD_READ * Read raw data from partition
1156 CONFIG_CMD_REGINFO * Register dump
1157 CONFIG_CMD_RUN run command in env variable
1158 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1159 CONFIG_CMD_SAVES * save S record dump
1160 CONFIG_CMD_SCSI * SCSI Support
1161 CONFIG_CMD_SDRAM * print SDRAM configuration information
1162 (requires CONFIG_CMD_I2C)
1163 CONFIG_CMD_SETGETDCR Support for DCR Register access
1165 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1166 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1167 (requires CONFIG_CMD_MEMORY)
1168 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1169 CONFIG_CMD_SOURCE "source" command Support
1170 CONFIG_CMD_SPI * SPI serial bus support
1171 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1172 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1173 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1174 CONFIG_CMD_TIMER * access to the system tick timer
1175 CONFIG_CMD_USB * USB support
1176 CONFIG_CMD_CDP * Cisco Discover Protocol support
1177 CONFIG_CMD_MFSL * Microblaze FSL support
1178 CONFIG_CMD_XIMG Load part of Multi Image
1179 CONFIG_CMD_UUID * Generate random UUID or GUID string
1181 EXAMPLE: If you want all functions except of network
1182 support you can write:
1184 #include "config_cmd_all.h"
1185 #undef CONFIG_CMD_NET
1188 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1190 Note: Don't enable the "icache" and "dcache" commands
1191 (configuration option CONFIG_CMD_CACHE) unless you know
1192 what you (and your U-Boot users) are doing. Data
1193 cache cannot be enabled on systems like the 8xx or
1194 8260 (where accesses to the IMMR region must be
1195 uncached), and it cannot be disabled on all other
1196 systems where we (mis-) use the data cache to hold an
1197 initial stack and some data.
1200 XXX - this list needs to get updated!
1202 - Regular expression support:
1204 If this variable is defined, U-Boot is linked against
1205 the SLRE (Super Light Regular Expression) library,
1206 which adds regex support to some commands, as for
1207 example "env grep" and "setexpr".
1211 If this variable is defined, U-Boot will use a device tree
1212 to configure its devices, instead of relying on statically
1213 compiled #defines in the board file. This option is
1214 experimental and only available on a few boards. The device
1215 tree is available in the global data as gd->fdt_blob.
1217 U-Boot needs to get its device tree from somewhere. This can
1218 be done using one of the two options below:
1221 If this variable is defined, U-Boot will embed a device tree
1222 binary in its image. This device tree file should be in the
1223 board directory and called <soc>-<board>.dts. The binary file
1224 is then picked up in board_init_f() and made available through
1225 the global data structure as gd->blob.
1228 If this variable is defined, U-Boot will build a device tree
1229 binary. It will be called u-boot.dtb. Architecture-specific
1230 code will locate it at run-time. Generally this works by:
1232 cat u-boot.bin u-boot.dtb >image.bin
1234 and in fact, U-Boot does this for you, creating a file called
1235 u-boot-dtb.bin which is useful in the common case. You can
1236 still use the individual files if you need something more
1241 If this variable is defined, it enables watchdog
1242 support for the SoC. There must be support in the SoC
1243 specific code for a watchdog. For the 8xx and 8260
1244 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1245 register. When supported for a specific SoC is
1246 available, then no further board specific code should
1247 be needed to use it.
1250 When using a watchdog circuitry external to the used
1251 SoC, then define this variable and provide board
1252 specific code for the "hw_watchdog_reset" function.
1255 CONFIG_VERSION_VARIABLE
1256 If this variable is defined, an environment variable
1257 named "ver" is created by U-Boot showing the U-Boot
1258 version as printed by the "version" command.
1259 Any change to this variable will be reverted at the
1264 When CONFIG_CMD_DATE is selected, the type of the RTC
1265 has to be selected, too. Define exactly one of the
1268 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1269 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1270 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1271 CONFIG_RTC_MC146818 - use MC146818 RTC
1272 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1273 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1274 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1275 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1276 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1277 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1278 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1279 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1280 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1283 Note that if the RTC uses I2C, then the I2C interface
1284 must also be configured. See I2C Support, below.
1287 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1289 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1290 chip-ngpio pairs that tell the PCA953X driver the number of
1291 pins supported by a particular chip.
1293 Note that if the GPIO device uses I2C, then the I2C interface
1294 must also be configured. See I2C Support, below.
1297 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1298 accesses and can checksum them or write a list of them out
1299 to memory. See the 'iotrace' command for details. This is
1300 useful for testing device drivers since it can confirm that
1301 the driver behaves the same way before and after a code
1302 change. Currently this is supported on sandbox and arm. To
1303 add support for your architecture, add '#include <iotrace.h>'
1304 to the bottom of arch/<arch>/include/asm/io.h and test.
1306 Example output from the 'iotrace stats' command is below.
1307 Note that if the trace buffer is exhausted, the checksum will
1308 still continue to operate.
1311 Start: 10000000 (buffer start address)
1312 Size: 00010000 (buffer size)
1313 Offset: 00000120 (current buffer offset)
1314 Output: 10000120 (start + offset)
1315 Count: 00000018 (number of trace records)
1316 CRC32: 9526fb66 (CRC32 of all trace records)
1318 - Timestamp Support:
1320 When CONFIG_TIMESTAMP is selected, the timestamp
1321 (date and time) of an image is printed by image
1322 commands like bootm or iminfo. This option is
1323 automatically enabled when you select CONFIG_CMD_DATE .
1325 - Partition Labels (disklabels) Supported:
1326 Zero or more of the following:
1327 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1328 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1329 Intel architecture, USB sticks, etc.
1330 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1331 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1332 bootloader. Note 2TB partition limit; see
1334 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1336 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1337 CONFIG_CMD_SCSI) you must configure support for at
1338 least one non-MTD partition type as well.
1341 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1342 board configurations files but used nowhere!
1344 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1345 be performed by calling the function
1346 ide_set_reset(int reset)
1347 which has to be defined in a board specific file
1352 Set this to enable ATAPI support.
1357 Set this to enable support for disks larger than 137GB
1358 Also look at CONFIG_SYS_64BIT_LBA.
1359 Whithout these , LBA48 support uses 32bit variables and will 'only'
1360 support disks up to 2.1TB.
1362 CONFIG_SYS_64BIT_LBA:
1363 When enabled, makes the IDE subsystem use 64bit sector addresses.
1367 At the moment only there is only support for the
1368 SYM53C8XX SCSI controller; define
1369 CONFIG_SCSI_SYM53C8XX to enable it.
1371 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1372 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1373 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1374 maximum numbers of LUNs, SCSI ID's and target
1376 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1378 The environment variable 'scsidevs' is set to the number of
1379 SCSI devices found during the last scan.
1381 - NETWORK Support (PCI):
1383 Support for Intel 8254x/8257x gigabit chips.
1386 Utility code for direct access to the SPI bus on Intel 8257x.
1387 This does not do anything useful unless you set at least one
1388 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1390 CONFIG_E1000_SPI_GENERIC
1391 Allow generic access to the SPI bus on the Intel 8257x, for
1392 example with the "sspi" command.
1395 Management command for E1000 devices. When used on devices
1396 with SPI support you can reprogram the EEPROM from U-Boot.
1398 CONFIG_E1000_FALLBACK_MAC
1399 default MAC for empty EEPROM after production.
1402 Support for Intel 82557/82559/82559ER chips.
1403 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1404 write routine for first time initialisation.
1407 Support for Digital 2114x chips.
1408 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1409 modem chip initialisation (KS8761/QS6611).
1412 Support for National dp83815 chips.
1415 Support for National dp8382[01] gigabit chips.
1417 - NETWORK Support (other):
1419 CONFIG_DRIVER_AT91EMAC
1420 Support for AT91RM9200 EMAC.
1423 Define this to use reduced MII inteface
1425 CONFIG_DRIVER_AT91EMAC_QUIET
1426 If this defined, the driver is quiet.
1427 The driver doen't show link status messages.
1429 CONFIG_CALXEDA_XGMAC
1430 Support for the Calxeda XGMAC device
1433 Support for SMSC's LAN91C96 chips.
1435 CONFIG_LAN91C96_BASE
1436 Define this to hold the physical address
1437 of the LAN91C96's I/O space
1439 CONFIG_LAN91C96_USE_32_BIT
1440 Define this to enable 32 bit addressing
1443 Support for SMSC's LAN91C111 chip
1445 CONFIG_SMC91111_BASE
1446 Define this to hold the physical address
1447 of the device (I/O space)
1449 CONFIG_SMC_USE_32_BIT
1450 Define this if data bus is 32 bits
1452 CONFIG_SMC_USE_IOFUNCS
1453 Define this to use i/o functions instead of macros
1454 (some hardware wont work with macros)
1456 CONFIG_DRIVER_TI_EMAC
1457 Support for davinci emac
1459 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1460 Define this if you have more then 3 PHYs.
1463 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1465 CONFIG_FTGMAC100_EGIGA
1466 Define this to use GE link update with gigabit PHY.
1467 Define this if FTGMAC100 is connected to gigabit PHY.
1468 If your system has 10/100 PHY only, it might not occur
1469 wrong behavior. Because PHY usually return timeout or
1470 useless data when polling gigabit status and gigabit
1471 control registers. This behavior won't affect the
1472 correctnessof 10/100 link speed update.
1475 Support for SMSC's LAN911x and LAN921x chips
1478 Define this to hold the physical address
1479 of the device (I/O space)
1481 CONFIG_SMC911X_32_BIT
1482 Define this if data bus is 32 bits
1484 CONFIG_SMC911X_16_BIT
1485 Define this if data bus is 16 bits. If your processor
1486 automatically converts one 32 bit word to two 16 bit
1487 words you may also try CONFIG_SMC911X_32_BIT.
1490 Support for Renesas on-chip Ethernet controller
1492 CONFIG_SH_ETHER_USE_PORT
1493 Define the number of ports to be used
1495 CONFIG_SH_ETHER_PHY_ADDR
1496 Define the ETH PHY's address
1498 CONFIG_SH_ETHER_CACHE_WRITEBACK
1499 If this option is set, the driver enables cache flush.
1503 Support for PWM modul on the imx6.
1507 Support TPM devices.
1510 Support for i2c bus TPM devices. Only one device
1511 per system is supported at this time.
1513 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1514 Define the the i2c bus number for the TPM device
1516 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1517 Define the TPM's address on the i2c bus
1519 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1520 Define the burst count bytes upper limit
1522 CONFIG_TPM_ATMEL_TWI
1523 Support for Atmel TWI TPM device. Requires I2C support.
1526 Support for generic parallel port TPM devices. Only one device
1527 per system is supported at this time.
1529 CONFIG_TPM_TIS_BASE_ADDRESS
1530 Base address where the generic TPM device is mapped
1531 to. Contemporary x86 systems usually map it at
1535 Add tpm monitor functions.
1536 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1537 provides monitor access to authorized functions.
1540 Define this to enable the TPM support library which provides
1541 functional interfaces to some TPM commands.
1542 Requires support for a TPM device.
1544 CONFIG_TPM_AUTH_SESSIONS
1545 Define this to enable authorized functions in the TPM library.
1546 Requires CONFIG_TPM and CONFIG_SHA1.
1549 At the moment only the UHCI host controller is
1550 supported (PIP405, MIP405, MPC5200); define
1551 CONFIG_USB_UHCI to enable it.
1552 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1553 and define CONFIG_USB_STORAGE to enable the USB
1556 Supported are USB Keyboards and USB Floppy drives
1558 MPC5200 USB requires additional defines:
1560 for 528 MHz Clock: 0x0001bbbb
1564 for differential drivers: 0x00001000
1565 for single ended drivers: 0x00005000
1566 for differential drivers on PSC3: 0x00000100
1567 for single ended drivers on PSC3: 0x00004100
1568 CONFIG_SYS_USB_EVENT_POLL
1569 May be defined to allow interrupt polling
1570 instead of using asynchronous interrupts
1572 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1573 txfilltuning field in the EHCI controller on reset.
1575 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1576 HW module registers.
1579 Define the below if you wish to use the USB console.
1580 Once firmware is rebuilt from a serial console issue the
1581 command "setenv stdin usbtty; setenv stdout usbtty" and
1582 attach your USB cable. The Unix command "dmesg" should print
1583 it has found a new device. The environment variable usbtty
1584 can be set to gserial or cdc_acm to enable your device to
1585 appear to a USB host as a Linux gserial device or a
1586 Common Device Class Abstract Control Model serial device.
1587 If you select usbtty = gserial you should be able to enumerate
1589 # modprobe usbserial vendor=0xVendorID product=0xProductID
1590 else if using cdc_acm, simply setting the environment
1591 variable usbtty to be cdc_acm should suffice. The following
1592 might be defined in YourBoardName.h
1595 Define this to build a UDC device
1598 Define this to have a tty type of device available to
1599 talk to the UDC device
1602 Define this to enable the high speed support for usb
1603 device and usbtty. If this feature is enabled, a routine
1604 int is_usbd_high_speed(void)
1605 also needs to be defined by the driver to dynamically poll
1606 whether the enumeration has succeded at high speed or full
1609 CONFIG_SYS_CONSOLE_IS_IN_ENV
1610 Define this if you want stdin, stdout &/or stderr to
1614 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1615 Derive USB clock from external clock "blah"
1616 - CONFIG_SYS_USB_EXTC_CLK 0x02
1618 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1619 Derive USB clock from brgclk
1620 - CONFIG_SYS_USB_BRG_CLK 0x04
1622 If you have a USB-IF assigned VendorID then you may wish to
1623 define your own vendor specific values either in BoardName.h
1624 or directly in usbd_vendor_info.h. If you don't define
1625 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1626 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1627 should pretend to be a Linux device to it's target host.
1629 CONFIG_USBD_MANUFACTURER
1630 Define this string as the name of your company for
1631 - CONFIG_USBD_MANUFACTURER "my company"
1633 CONFIG_USBD_PRODUCT_NAME
1634 Define this string as the name of your product
1635 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1637 CONFIG_USBD_VENDORID
1638 Define this as your assigned Vendor ID from the USB
1639 Implementors Forum. This *must* be a genuine Vendor ID
1640 to avoid polluting the USB namespace.
1641 - CONFIG_USBD_VENDORID 0xFFFF
1643 CONFIG_USBD_PRODUCTID
1644 Define this as the unique Product ID
1646 - CONFIG_USBD_PRODUCTID 0xFFFF
1648 - ULPI Layer Support:
1649 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1650 the generic ULPI layer. The generic layer accesses the ULPI PHY
1651 via the platform viewport, so you need both the genric layer and
1652 the viewport enabled. Currently only Chipidea/ARC based
1653 viewport is supported.
1654 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1655 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1656 If your ULPI phy needs a different reference clock than the
1657 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1658 the appropriate value in Hz.
1661 The MMC controller on the Intel PXA is supported. To
1662 enable this define CONFIG_MMC. The MMC can be
1663 accessed from the boot prompt by mapping the device
1664 to physical memory similar to flash. Command line is
1665 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1666 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1669 Support for Renesas on-chip MMCIF controller
1671 CONFIG_SH_MMCIF_ADDR
1672 Define the base address of MMCIF registers
1675 Define the clock frequency for MMCIF
1678 Enable the generic MMC driver
1680 CONFIG_SUPPORT_EMMC_BOOT
1681 Enable some additional features of the eMMC boot partitions.
1683 CONFIG_SUPPORT_EMMC_RPMB
1684 Enable the commands for reading, writing and programming the
1685 key for the Replay Protection Memory Block partition in eMMC.
1687 - USB Device Firmware Update (DFU) class support:
1689 This enables the USB portion of the DFU USB class
1692 This enables the command "dfu" which is used to have
1693 U-Boot create a DFU class device via USB. This command
1694 requires that the "dfu_alt_info" environment variable be
1695 set and define the alt settings to expose to the host.
1698 This enables support for exposing (e)MMC devices via DFU.
1701 This enables support for exposing NAND devices via DFU.
1704 This enables support for exposing RAM via DFU.
1705 Note: DFU spec refer to non-volatile memory usage, but
1706 allow usages beyond the scope of spec - here RAM usage,
1707 one that would help mostly the developer.
1709 CONFIG_SYS_DFU_DATA_BUF_SIZE
1710 Dfu transfer uses a buffer before writing data to the
1711 raw storage device. Make the size (in bytes) of this buffer
1712 configurable. The size of this buffer is also configurable
1713 through the "dfu_bufsiz" environment variable.
1715 CONFIG_SYS_DFU_MAX_FILE_SIZE
1716 When updating files rather than the raw storage device,
1717 we use a static buffer to copy the file into and then write
1718 the buffer once we've been given the whole file. Define
1719 this to the maximum filesize (in bytes) for the buffer.
1720 Default is 4 MiB if undefined.
1722 DFU_DEFAULT_POLL_TIMEOUT
1723 Poll timeout [ms], is the timeout a device can send to the
1724 host. The host must wait for this timeout before sending
1725 a subsequent DFU_GET_STATUS request to the device.
1727 DFU_MANIFEST_POLL_TIMEOUT
1728 Poll timeout [ms], which the device sends to the host when
1729 entering dfuMANIFEST state. Host waits this timeout, before
1730 sending again an USB request to the device.
1732 - USB Device Android Fastboot support:
1734 This enables the command "fastboot" which enables the Android
1735 fastboot mode for the platform's USB device. Fastboot is a USB
1736 protocol for downloading images, flashing and device control
1737 used on Android devices.
1738 See doc/README.android-fastboot for more information.
1740 CONFIG_ANDROID_BOOT_IMAGE
1741 This enables support for booting images which use the Android
1742 image format header.
1744 CONFIG_USB_FASTBOOT_BUF_ADDR
1745 The fastboot protocol requires a large memory buffer for
1746 downloads. Define this to the starting RAM address to use for
1749 CONFIG_USB_FASTBOOT_BUF_SIZE
1750 The fastboot protocol requires a large memory buffer for
1751 downloads. This buffer should be as large as possible for a
1752 platform. Define this to the size available RAM for fastboot.
1754 CONFIG_FASTBOOT_FLASH
1755 The fastboot protocol includes a "flash" command for writing
1756 the downloaded image to a non-volatile storage device. Define
1757 this to enable the "fastboot flash" command.
1759 CONFIG_FASTBOOT_FLASH_MMC_DEV
1760 The fastboot "flash" command requires additional information
1761 regarding the non-volatile storage device. Define this to
1762 the eMMC device that fastboot should use to store the image.
1764 - Journaling Flash filesystem support:
1765 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1766 CONFIG_JFFS2_NAND_DEV
1767 Define these for a default partition on a NAND device
1769 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1770 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1771 Define these for a default partition on a NOR device
1773 CONFIG_SYS_JFFS_CUSTOM_PART
1774 Define this to create an own partition. You have to provide a
1775 function struct part_info* jffs2_part_info(int part_num)
1777 If you define only one JFFS2 partition you may also want to
1778 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1779 to disable the command chpart. This is the default when you
1780 have not defined a custom partition
1782 - FAT(File Allocation Table) filesystem write function support:
1785 Define this to enable support for saving memory data as a
1786 file in FAT formatted partition.
1788 This will also enable the command "fatwrite" enabling the
1789 user to write files to FAT.
1791 CBFS (Coreboot Filesystem) support
1794 Define this to enable support for reading from a Coreboot
1795 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1798 - FAT(File Allocation Table) filesystem cluster size:
1799 CONFIG_FS_FAT_MAX_CLUSTSIZE
1801 Define the max cluster size for fat operations else
1802 a default value of 65536 will be defined.
1807 Define this to enable standard (PC-Style) keyboard
1811 Standard PC keyboard driver with US (is default) and
1812 GERMAN key layout (switch via environment 'keymap=de') support.
1813 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1814 for cfb_console. Supports cursor blinking.
1817 Enables a Chrome OS keyboard using the CROS_EC interface.
1818 This uses CROS_EC to communicate with a second microcontroller
1819 which provides key scans on request.
1824 Define this to enable video support (for output to
1827 CONFIG_VIDEO_CT69000
1829 Enable Chips & Technologies 69000 Video chip
1831 CONFIG_VIDEO_SMI_LYNXEM
1832 Enable Silicon Motion SMI 712/710/810 Video chip. The
1833 video output is selected via environment 'videoout'
1834 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1837 For the CT69000 and SMI_LYNXEM drivers, videomode is
1838 selected via environment 'videomode'. Two different ways
1840 - "videomode=num" 'num' is a standard LiLo mode numbers.
1841 Following standard modes are supported (* is default):
1843 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1844 -------------+---------------------------------------------
1845 8 bits | 0x301* 0x303 0x305 0x161 0x307
1846 15 bits | 0x310 0x313 0x316 0x162 0x319
1847 16 bits | 0x311 0x314 0x317 0x163 0x31A
1848 24 bits | 0x312 0x315 0x318 ? 0x31B
1849 -------------+---------------------------------------------
1850 (i.e. setenv videomode 317; saveenv; reset;)
1852 - "videomode=bootargs" all the video parameters are parsed
1853 from the bootargs. (See drivers/video/videomodes.c)
1856 CONFIG_VIDEO_SED13806
1857 Enable Epson SED13806 driver. This driver supports 8bpp
1858 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1859 or CONFIG_VIDEO_SED13806_16BPP
1862 Enable the Freescale DIU video driver. Reference boards for
1863 SOCs that have a DIU should define this macro to enable DIU
1864 support, and should also define these other macros:
1870 CONFIG_VIDEO_SW_CURSOR
1871 CONFIG_VGA_AS_SINGLE_DEVICE
1873 CONFIG_VIDEO_BMP_LOGO
1875 The DIU driver will look for the 'video-mode' environment
1876 variable, and if defined, enable the DIU as a console during
1877 boot. See the documentation file README.video for a
1878 description of this variable.
1882 Enable the VGA video / BIOS for x86. The alternative if you
1883 are using coreboot is to use the coreboot frame buffer
1890 Define this to enable a custom keyboard support.
1891 This simply calls drv_keyboard_init() which must be
1892 defined in your board-specific files.
1893 The only board using this so far is RBC823.
1895 - LCD Support: CONFIG_LCD
1897 Define this to enable LCD support (for output to LCD
1898 display); also select one of the supported displays
1899 by defining one of these:
1903 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1905 CONFIG_NEC_NL6448AC33:
1907 NEC NL6448AC33-18. Active, color, single scan.
1909 CONFIG_NEC_NL6448BC20
1911 NEC NL6448BC20-08. 6.5", 640x480.
1912 Active, color, single scan.
1914 CONFIG_NEC_NL6448BC33_54
1916 NEC NL6448BC33-54. 10.4", 640x480.
1917 Active, color, single scan.
1921 Sharp 320x240. Active, color, single scan.
1922 It isn't 16x9, and I am not sure what it is.
1924 CONFIG_SHARP_LQ64D341
1926 Sharp LQ64D341 display, 640x480.
1927 Active, color, single scan.
1931 HLD1045 display, 640x480.
1932 Active, color, single scan.
1936 Optrex CBL50840-2 NF-FW 99 22 M5
1938 Hitachi LMG6912RPFC-00T
1942 320x240. Black & white.
1944 Normally display is black on white background; define
1945 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1947 CONFIG_LCD_ALIGNMENT
1949 Normally the LCD is page-aligned (tyically 4KB). If this is
1950 defined then the LCD will be aligned to this value instead.
1951 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1952 here, since it is cheaper to change data cache settings on
1953 a per-section basis.
1955 CONFIG_CONSOLE_SCROLL_LINES
1957 When the console need to be scrolled, this is the number of
1958 lines to scroll by. It defaults to 1. Increasing this makes
1959 the console jump but can help speed up operation when scrolling
1964 Support drawing of RLE8-compressed bitmaps on the LCD.
1968 Enables an 'i2c edid' command which can read EDID
1969 information over I2C from an attached LCD display.
1971 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1973 If this option is set, the environment is checked for
1974 a variable "splashimage". If found, the usual display
1975 of logo, copyright and system information on the LCD
1976 is suppressed and the BMP image at the address
1977 specified in "splashimage" is loaded instead. The
1978 console is redirected to the "nulldev", too. This
1979 allows for a "silent" boot where a splash screen is
1980 loaded very quickly after power-on.
1982 CONFIG_SPLASHIMAGE_GUARD
1984 If this option is set, then U-Boot will prevent the environment
1985 variable "splashimage" from being set to a problematic address
1986 (see README.displaying-bmps).
1987 This option is useful for targets where, due to alignment
1988 restrictions, an improperly aligned BMP image will cause a data
1989 abort. If you think you will not have problems with unaligned
1990 accesses (for example because your toolchain prevents them)
1991 there is no need to set this option.
1993 CONFIG_SPLASH_SCREEN_ALIGN
1995 If this option is set the splash image can be freely positioned
1996 on the screen. Environment variable "splashpos" specifies the
1997 position as "x,y". If a positive number is given it is used as
1998 number of pixel from left/top. If a negative number is given it
1999 is used as number of pixel from right/bottom. You can also
2000 specify 'm' for centering the image.
2003 setenv splashpos m,m
2004 => image at center of screen
2006 setenv splashpos 30,20
2007 => image at x = 30 and y = 20
2009 setenv splashpos -10,m
2010 => vertically centered image
2011 at x = dspWidth - bmpWidth - 9
2013 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2015 If this option is set, additionally to standard BMP
2016 images, gzipped BMP images can be displayed via the
2017 splashscreen support or the bmp command.
2019 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2021 If this option is set, 8-bit RLE compressed BMP images
2022 can be displayed via the splashscreen support or the
2025 - Do compresssing for memory range:
2028 If this option is set, it would use zlib deflate method
2029 to compress the specified memory at its best effort.
2031 - Compression support:
2034 Enabled by default to support gzip compressed images.
2038 If this option is set, support for bzip2 compressed
2039 images is included. If not, only uncompressed and gzip
2040 compressed images are supported.
2042 NOTE: the bzip2 algorithm requires a lot of RAM, so
2043 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2048 If this option is set, support for lzma compressed
2051 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2052 requires an amount of dynamic memory that is given by the
2055 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2057 Where lc and lp stand for, respectively, Literal context bits
2058 and Literal pos bits.
2060 This value is upper-bounded by 14MB in the worst case. Anyway,
2061 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2062 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2063 a very small buffer.
2065 Use the lzmainfo tool to determinate the lc and lp values and
2066 then calculate the amount of needed dynamic memory (ensuring
2067 the appropriate CONFIG_SYS_MALLOC_LEN value).
2071 If this option is set, support for LZO compressed images
2077 The address of PHY on MII bus.
2079 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2081 The clock frequency of the MII bus
2085 If this option is set, support for speed/duplex
2086 detection of gigabit PHY is included.
2088 CONFIG_PHY_RESET_DELAY
2090 Some PHY like Intel LXT971A need extra delay after
2091 reset before any MII register access is possible.
2092 For such PHY, set this option to the usec delay
2093 required. (minimum 300usec for LXT971A)
2095 CONFIG_PHY_CMD_DELAY (ppc4xx)
2097 Some PHY like Intel LXT971A need extra delay after
2098 command issued before MII status register can be read
2108 Define a default value for Ethernet address to use
2109 for the respective Ethernet interface, in case this
2110 is not determined automatically.
2115 Define a default value for the IP address to use for
2116 the default Ethernet interface, in case this is not
2117 determined through e.g. bootp.
2118 (Environment variable "ipaddr")
2120 - Server IP address:
2123 Defines a default value for the IP address of a TFTP
2124 server to contact when using the "tftboot" command.
2125 (Environment variable "serverip")
2127 CONFIG_KEEP_SERVERADDR
2129 Keeps the server's MAC address, in the env 'serveraddr'
2130 for passing to bootargs (like Linux's netconsole option)
2132 - Gateway IP address:
2135 Defines a default value for the IP address of the
2136 default router where packets to other networks are
2138 (Environment variable "gatewayip")
2143 Defines a default value for the subnet mask (or
2144 routing prefix) which is used to determine if an IP
2145 address belongs to the local subnet or needs to be
2146 forwarded through a router.
2147 (Environment variable "netmask")
2149 - Multicast TFTP Mode:
2152 Defines whether you want to support multicast TFTP as per
2153 rfc-2090; for example to work with atftp. Lets lots of targets
2154 tftp down the same boot image concurrently. Note: the Ethernet
2155 driver in use must provide a function: mcast() to join/leave a
2158 - BOOTP Recovery Mode:
2159 CONFIG_BOOTP_RANDOM_DELAY
2161 If you have many targets in a network that try to
2162 boot using BOOTP, you may want to avoid that all
2163 systems send out BOOTP requests at precisely the same
2164 moment (which would happen for instance at recovery
2165 from a power failure, when all systems will try to
2166 boot, thus flooding the BOOTP server. Defining
2167 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2168 inserted before sending out BOOTP requests. The
2169 following delays are inserted then:
2171 1st BOOTP request: delay 0 ... 1 sec
2172 2nd BOOTP request: delay 0 ... 2 sec
2173 3rd BOOTP request: delay 0 ... 4 sec
2175 BOOTP requests: delay 0 ... 8 sec
2177 CONFIG_BOOTP_ID_CACHE_SIZE
2179 BOOTP packets are uniquely identified using a 32-bit ID. The
2180 server will copy the ID from client requests to responses and
2181 U-Boot will use this to determine if it is the destination of
2182 an incoming response. Some servers will check that addresses
2183 aren't in use before handing them out (usually using an ARP
2184 ping) and therefore take up to a few hundred milliseconds to
2185 respond. Network congestion may also influence the time it
2186 takes for a response to make it back to the client. If that
2187 time is too long, U-Boot will retransmit requests. In order
2188 to allow earlier responses to still be accepted after these
2189 retransmissions, U-Boot's BOOTP client keeps a small cache of
2190 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2191 cache. The default is to keep IDs for up to four outstanding
2192 requests. Increasing this will allow U-Boot to accept offers
2193 from a BOOTP client in networks with unusually high latency.
2195 - DHCP Advanced Options:
2196 You can fine tune the DHCP functionality by defining
2197 CONFIG_BOOTP_* symbols:
2199 CONFIG_BOOTP_SUBNETMASK
2200 CONFIG_BOOTP_GATEWAY
2201 CONFIG_BOOTP_HOSTNAME
2202 CONFIG_BOOTP_NISDOMAIN
2203 CONFIG_BOOTP_BOOTPATH
2204 CONFIG_BOOTP_BOOTFILESIZE
2207 CONFIG_BOOTP_SEND_HOSTNAME
2208 CONFIG_BOOTP_NTPSERVER
2209 CONFIG_BOOTP_TIMEOFFSET
2210 CONFIG_BOOTP_VENDOREX
2211 CONFIG_BOOTP_MAY_FAIL
2213 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2214 environment variable, not the BOOTP server.
2216 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2217 after the configured retry count, the call will fail
2218 instead of starting over. This can be used to fail over
2219 to Link-local IP address configuration if the DHCP server
2222 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2223 serverip from a DHCP server, it is possible that more
2224 than one DNS serverip is offered to the client.
2225 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2226 serverip will be stored in the additional environment
2227 variable "dnsip2". The first DNS serverip is always
2228 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2231 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2232 to do a dynamic update of a DNS server. To do this, they
2233 need the hostname of the DHCP requester.
2234 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2235 of the "hostname" environment variable is passed as
2236 option 12 to the DHCP server.
2238 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2240 A 32bit value in microseconds for a delay between
2241 receiving a "DHCP Offer" and sending the "DHCP Request".
2242 This fixes a problem with certain DHCP servers that don't
2243 respond 100% of the time to a "DHCP request". E.g. On an
2244 AT91RM9200 processor running at 180MHz, this delay needed
2245 to be *at least* 15,000 usec before a Windows Server 2003
2246 DHCP server would reply 100% of the time. I recommend at
2247 least 50,000 usec to be safe. The alternative is to hope
2248 that one of the retries will be successful but note that
2249 the DHCP timeout and retry process takes a longer than
2252 - Link-local IP address negotiation:
2253 Negotiate with other link-local clients on the local network
2254 for an address that doesn't require explicit configuration.
2255 This is especially useful if a DHCP server cannot be guaranteed
2256 to exist in all environments that the device must operate.
2258 See doc/README.link-local for more information.
2261 CONFIG_CDP_DEVICE_ID
2263 The device id used in CDP trigger frames.
2265 CONFIG_CDP_DEVICE_ID_PREFIX
2267 A two character string which is prefixed to the MAC address
2272 A printf format string which contains the ascii name of
2273 the port. Normally is set to "eth%d" which sets
2274 eth0 for the first Ethernet, eth1 for the second etc.
2276 CONFIG_CDP_CAPABILITIES
2278 A 32bit integer which indicates the device capabilities;
2279 0x00000010 for a normal host which does not forwards.
2283 An ascii string containing the version of the software.
2287 An ascii string containing the name of the platform.
2291 A 32bit integer sent on the trigger.
2293 CONFIG_CDP_POWER_CONSUMPTION
2295 A 16bit integer containing the power consumption of the
2296 device in .1 of milliwatts.
2298 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2300 A byte containing the id of the VLAN.
2302 - Status LED: CONFIG_STATUS_LED
2304 Several configurations allow to display the current
2305 status using a LED. For instance, the LED will blink
2306 fast while running U-Boot code, stop blinking as
2307 soon as a reply to a BOOTP request was received, and
2308 start blinking slow once the Linux kernel is running
2309 (supported by a status LED driver in the Linux
2310 kernel). Defining CONFIG_STATUS_LED enables this
2316 The status LED can be connected to a GPIO pin.
2317 In such cases, the gpio_led driver can be used as a
2318 status LED backend implementation. Define CONFIG_GPIO_LED
2319 to include the gpio_led driver in the U-Boot binary.
2321 CONFIG_GPIO_LED_INVERTED_TABLE
2322 Some GPIO connected LEDs may have inverted polarity in which
2323 case the GPIO high value corresponds to LED off state and
2324 GPIO low value corresponds to LED on state.
2325 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2326 with a list of GPIO LEDs that have inverted polarity.
2328 - CAN Support: CONFIG_CAN_DRIVER
2330 Defining CONFIG_CAN_DRIVER enables CAN driver support
2331 on those systems that support this (optional)
2332 feature, like the TQM8xxL modules.
2334 - I2C Support: CONFIG_SYS_I2C
2336 This enable the NEW i2c subsystem, and will allow you to use
2337 i2c commands at the u-boot command line (as long as you set
2338 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2339 based realtime clock chips or other i2c devices. See
2340 common/cmd_i2c.c for a description of the command line
2343 ported i2c driver to the new framework:
2344 - drivers/i2c/soft_i2c.c:
2345 - activate first bus with CONFIG_SYS_I2C_SOFT define
2346 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2347 for defining speed and slave address
2348 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2349 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2350 for defining speed and slave address
2351 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2352 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2353 for defining speed and slave address
2354 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2355 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2356 for defining speed and slave address
2358 - drivers/i2c/fsl_i2c.c:
2359 - activate i2c driver with CONFIG_SYS_I2C_FSL
2360 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2361 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2362 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2364 - If your board supports a second fsl i2c bus, define
2365 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2366 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2367 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2370 - drivers/i2c/tegra_i2c.c:
2371 - activate this driver with CONFIG_SYS_I2C_TEGRA
2372 - This driver adds 4 i2c buses with a fix speed from
2373 100000 and the slave addr 0!
2375 - drivers/i2c/ppc4xx_i2c.c
2376 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2377 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2378 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2380 - drivers/i2c/i2c_mxc.c
2381 - activate this driver with CONFIG_SYS_I2C_MXC
2382 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2383 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2384 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2385 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2386 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2387 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2388 If thoses defines are not set, default value is 100000
2389 for speed, and 0 for slave.
2391 - drivers/i2c/rcar_i2c.c:
2392 - activate this driver with CONFIG_SYS_I2C_RCAR
2393 - This driver adds 4 i2c buses
2395 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2396 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2397 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2398 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2399 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2400 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2401 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2402 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2403 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2405 - drivers/i2c/sh_i2c.c:
2406 - activate this driver with CONFIG_SYS_I2C_SH
2407 - This driver adds from 2 to 5 i2c buses
2409 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2410 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2411 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2412 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2413 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2414 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2415 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2416 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2417 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2418 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2419 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2420 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2421 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2423 - drivers/i2c/omap24xx_i2c.c
2424 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2425 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2426 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2427 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2428 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2429 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2430 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2431 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2432 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2433 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2434 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2436 - drivers/i2c/zynq_i2c.c
2437 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2438 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2439 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2441 - drivers/i2c/s3c24x0_i2c.c:
2442 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2443 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2444 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2445 with a fix speed from 100000 and the slave addr 0!
2447 - drivers/i2c/ihs_i2c.c
2448 - activate this driver with CONFIG_SYS_I2C_IHS
2449 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2450 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2451 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2452 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2453 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2454 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2455 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2456 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2457 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2458 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2459 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2460 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2464 CONFIG_SYS_NUM_I2C_BUSES
2465 Hold the number of i2c busses you want to use. If you
2466 don't use/have i2c muxes on your i2c bus, this
2467 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2470 CONFIG_SYS_I2C_DIRECT_BUS
2471 define this, if you don't use i2c muxes on your hardware.
2472 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2475 CONFIG_SYS_I2C_MAX_HOPS
2476 define how many muxes are maximal consecutively connected
2477 on one i2c bus. If you not use i2c muxes, omit this
2480 CONFIG_SYS_I2C_BUSES
2481 hold a list of busses you want to use, only used if
2482 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2483 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2484 CONFIG_SYS_NUM_I2C_BUSES = 9:
2486 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2487 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2488 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2489 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2490 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2491 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2492 {1, {I2C_NULL_HOP}}, \
2493 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2494 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2498 bus 0 on adapter 0 without a mux
2499 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2500 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2501 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2502 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2503 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2504 bus 6 on adapter 1 without a mux
2505 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2506 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2508 If you do not have i2c muxes on your board, omit this define.
2510 - Legacy I2C Support: CONFIG_HARD_I2C
2512 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2513 provides the following compelling advantages:
2515 - more than one i2c adapter is usable
2516 - approved multibus support
2517 - better i2c mux support
2519 ** Please consider updating your I2C driver now. **
2521 These enable legacy I2C serial bus commands. Defining
2522 CONFIG_HARD_I2C will include the appropriate I2C driver
2523 for the selected CPU.
2525 This will allow you to use i2c commands at the u-boot
2526 command line (as long as you set CONFIG_CMD_I2C in
2527 CONFIG_COMMANDS) and communicate with i2c based realtime
2528 clock chips. See common/cmd_i2c.c for a description of the
2529 command line interface.
2531 CONFIG_HARD_I2C selects a hardware I2C controller.
2533 There are several other quantities that must also be
2534 defined when you define CONFIG_HARD_I2C.
2536 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2537 to be the frequency (in Hz) at which you wish your i2c bus
2538 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2539 the CPU's i2c node address).
2541 Now, the u-boot i2c code for the mpc8xx
2542 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2543 and so its address should therefore be cleared to 0 (See,
2544 eg, MPC823e User's Manual p.16-473). So, set
2545 CONFIG_SYS_I2C_SLAVE to 0.
2547 CONFIG_SYS_I2C_INIT_MPC5XXX
2549 When a board is reset during an i2c bus transfer
2550 chips might think that the current transfer is still
2551 in progress. Reset the slave devices by sending start
2552 commands until the slave device responds.
2554 That's all that's required for CONFIG_HARD_I2C.
2556 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2557 then the following macros need to be defined (examples are
2558 from include/configs/lwmon.h):
2562 (Optional). Any commands necessary to enable the I2C
2563 controller or configure ports.
2565 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2569 (Only for MPC8260 CPU). The I/O port to use (the code
2570 assumes both bits are on the same port). Valid values
2571 are 0..3 for ports A..D.
2575 The code necessary to make the I2C data line active
2576 (driven). If the data line is open collector, this
2579 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2583 The code necessary to make the I2C data line tri-stated
2584 (inactive). If the data line is open collector, this
2587 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2591 Code that returns true if the I2C data line is high,
2594 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2598 If <bit> is true, sets the I2C data line high. If it
2599 is false, it clears it (low).
2601 eg: #define I2C_SDA(bit) \
2602 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2603 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2607 If <bit> is true, sets the I2C clock line high. If it
2608 is false, it clears it (low).
2610 eg: #define I2C_SCL(bit) \
2611 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2612 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2616 This delay is invoked four times per clock cycle so this
2617 controls the rate of data transfer. The data rate thus
2618 is 1 / (I2C_DELAY * 4). Often defined to be something
2621 #define I2C_DELAY udelay(2)
2623 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2625 If your arch supports the generic GPIO framework (asm/gpio.h),
2626 then you may alternatively define the two GPIOs that are to be
2627 used as SCL / SDA. Any of the previous I2C_xxx macros will
2628 have GPIO-based defaults assigned to them as appropriate.
2630 You should define these to the GPIO value as given directly to
2631 the generic GPIO functions.
2633 CONFIG_SYS_I2C_INIT_BOARD
2635 When a board is reset during an i2c bus transfer
2636 chips might think that the current transfer is still
2637 in progress. On some boards it is possible to access
2638 the i2c SCLK line directly, either by using the
2639 processor pin as a GPIO or by having a second pin
2640 connected to the bus. If this option is defined a
2641 custom i2c_init_board() routine in boards/xxx/board.c
2642 is run early in the boot sequence.
2644 CONFIG_SYS_I2C_BOARD_LATE_INIT
2646 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2647 defined a custom i2c_board_late_init() routine in
2648 boards/xxx/board.c is run AFTER the operations in i2c_init()
2649 is completed. This callpoint can be used to unreset i2c bus
2650 using CPU i2c controller register accesses for CPUs whose i2c
2651 controller provide such a method. It is called at the end of
2652 i2c_init() to allow i2c_init operations to setup the i2c bus
2653 controller on the CPU (e.g. setting bus speed & slave address).
2655 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2657 This option enables configuration of bi_iic_fast[] flags
2658 in u-boot bd_info structure based on u-boot environment
2659 variable "i2cfast". (see also i2cfast)
2661 CONFIG_I2C_MULTI_BUS
2663 This option allows the use of multiple I2C buses, each of which
2664 must have a controller. At any point in time, only one bus is
2665 active. To switch to a different bus, use the 'i2c dev' command.
2666 Note that bus numbering is zero-based.
2668 CONFIG_SYS_I2C_NOPROBES
2670 This option specifies a list of I2C devices that will be skipped
2671 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2672 is set, specify a list of bus-device pairs. Otherwise, specify
2673 a 1D array of device addresses
2676 #undef CONFIG_I2C_MULTI_BUS
2677 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2679 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2681 #define CONFIG_I2C_MULTI_BUS
2682 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2684 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2686 CONFIG_SYS_SPD_BUS_NUM
2688 If defined, then this indicates the I2C bus number for DDR SPD.
2689 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2691 CONFIG_SYS_RTC_BUS_NUM
2693 If defined, then this indicates the I2C bus number for the RTC.
2694 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2696 CONFIG_SYS_DTT_BUS_NUM
2698 If defined, then this indicates the I2C bus number for the DTT.
2699 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2701 CONFIG_SYS_I2C_DTT_ADDR:
2703 If defined, specifies the I2C address of the DTT device.
2704 If not defined, then U-Boot uses predefined value for
2705 specified DTT device.
2707 CONFIG_SOFT_I2C_READ_REPEATED_START
2709 defining this will force the i2c_read() function in
2710 the soft_i2c driver to perform an I2C repeated start
2711 between writing the address pointer and reading the
2712 data. If this define is omitted the default behaviour
2713 of doing a stop-start sequence will be used. Most I2C
2714 devices can use either method, but some require one or
2717 - SPI Support: CONFIG_SPI
2719 Enables SPI driver (so far only tested with
2720 SPI EEPROM, also an instance works with Crystal A/D and
2721 D/As on the SACSng board)
2725 Enables the driver for SPI controller on SuperH. Currently
2726 only SH7757 is supported.
2730 Enables extended (16-bit) SPI EEPROM addressing.
2731 (symmetrical to CONFIG_I2C_X)
2735 Enables a software (bit-bang) SPI driver rather than
2736 using hardware support. This is a general purpose
2737 driver that only requires three general I/O port pins
2738 (two outputs, one input) to function. If this is
2739 defined, the board configuration must define several
2740 SPI configuration items (port pins to use, etc). For
2741 an example, see include/configs/sacsng.h.
2745 Enables a hardware SPI driver for general-purpose reads
2746 and writes. As with CONFIG_SOFT_SPI, the board configuration
2747 must define a list of chip-select function pointers.
2748 Currently supported on some MPC8xxx processors. For an
2749 example, see include/configs/mpc8349emds.h.
2753 Enables the driver for the SPI controllers on i.MX and MXC
2754 SoCs. Currently i.MX31/35/51 are supported.
2756 CONFIG_SYS_SPI_MXC_WAIT
2757 Timeout for waiting until spi transfer completed.
2758 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2760 - FPGA Support: CONFIG_FPGA
2762 Enables FPGA subsystem.
2764 CONFIG_FPGA_<vendor>
2766 Enables support for specific chip vendors.
2769 CONFIG_FPGA_<family>
2771 Enables support for FPGA family.
2772 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2776 Specify the number of FPGA devices to support.
2778 CONFIG_CMD_FPGA_LOADMK
2780 Enable support for fpga loadmk command
2782 CONFIG_CMD_FPGA_LOADP
2784 Enable support for fpga loadp command - load partial bitstream
2786 CONFIG_CMD_FPGA_LOADBP
2788 Enable support for fpga loadbp command - load partial bitstream
2791 CONFIG_SYS_FPGA_PROG_FEEDBACK
2793 Enable printing of hash marks during FPGA configuration.
2795 CONFIG_SYS_FPGA_CHECK_BUSY
2797 Enable checks on FPGA configuration interface busy
2798 status by the configuration function. This option
2799 will require a board or device specific function to
2804 If defined, a function that provides delays in the FPGA
2805 configuration driver.
2807 CONFIG_SYS_FPGA_CHECK_CTRLC
2808 Allow Control-C to interrupt FPGA configuration
2810 CONFIG_SYS_FPGA_CHECK_ERROR
2812 Check for configuration errors during FPGA bitfile
2813 loading. For example, abort during Virtex II
2814 configuration if the INIT_B line goes low (which
2815 indicated a CRC error).
2817 CONFIG_SYS_FPGA_WAIT_INIT
2819 Maximum time to wait for the INIT_B line to deassert
2820 after PROB_B has been deasserted during a Virtex II
2821 FPGA configuration sequence. The default time is 500
2824 CONFIG_SYS_FPGA_WAIT_BUSY
2826 Maximum time to wait for BUSY to deassert during
2827 Virtex II FPGA configuration. The default is 5 ms.
2829 CONFIG_SYS_FPGA_WAIT_CONFIG
2831 Time to wait after FPGA configuration. The default is
2834 - Configuration Management:
2837 Some SoCs need special image types (e.g. U-Boot binary
2838 with a special header) as build targets. By defining
2839 CONFIG_BUILD_TARGET in the SoC / board header, this
2840 special image will be automatically built upon calling
2845 If defined, this string will be added to the U-Boot
2846 version information (U_BOOT_VERSION)
2848 - Vendor Parameter Protection:
2850 U-Boot considers the values of the environment
2851 variables "serial#" (Board Serial Number) and
2852 "ethaddr" (Ethernet Address) to be parameters that
2853 are set once by the board vendor / manufacturer, and
2854 protects these variables from casual modification by
2855 the user. Once set, these variables are read-only,
2856 and write or delete attempts are rejected. You can
2857 change this behaviour:
2859 If CONFIG_ENV_OVERWRITE is #defined in your config
2860 file, the write protection for vendor parameters is
2861 completely disabled. Anybody can change or delete
2864 Alternatively, if you #define _both_ CONFIG_ETHADDR
2865 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2866 Ethernet address is installed in the environment,
2867 which can be changed exactly ONCE by the user. [The
2868 serial# is unaffected by this, i. e. it remains
2871 The same can be accomplished in a more flexible way
2872 for any variable by configuring the type of access
2873 to allow for those variables in the ".flags" variable
2874 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2879 Define this variable to enable the reservation of
2880 "protected RAM", i. e. RAM which is not overwritten
2881 by U-Boot. Define CONFIG_PRAM to hold the number of
2882 kB you want to reserve for pRAM. You can overwrite
2883 this default value by defining an environment
2884 variable "pram" to the number of kB you want to
2885 reserve. Note that the board info structure will
2886 still show the full amount of RAM. If pRAM is
2887 reserved, a new environment variable "mem" will
2888 automatically be defined to hold the amount of
2889 remaining RAM in a form that can be passed as boot
2890 argument to Linux, for instance like that:
2892 setenv bootargs ... mem=\${mem}
2895 This way you can tell Linux not to use this memory,
2896 either, which results in a memory region that will
2897 not be affected by reboots.
2899 *WARNING* If your board configuration uses automatic
2900 detection of the RAM size, you must make sure that
2901 this memory test is non-destructive. So far, the
2902 following board configurations are known to be
2905 IVMS8, IVML24, SPD8xx, TQM8xxL,
2906 HERMES, IP860, RPXlite, LWMON,
2909 - Access to physical memory region (> 4GB)
2910 Some basic support is provided for operations on memory not
2911 normally accessible to U-Boot - e.g. some architectures
2912 support access to more than 4GB of memory on 32-bit
2913 machines using physical address extension or similar.
2914 Define CONFIG_PHYSMEM to access this basic support, which
2915 currently only supports clearing the memory.
2920 Define this variable to stop the system in case of a
2921 fatal error, so that you have to reset it manually.
2922 This is probably NOT a good idea for an embedded
2923 system where you want the system to reboot
2924 automatically as fast as possible, but it may be
2925 useful during development since you can try to debug
2926 the conditions that lead to the situation.
2928 CONFIG_NET_RETRY_COUNT
2930 This variable defines the number of retries for
2931 network operations like ARP, RARP, TFTP, or BOOTP
2932 before giving up the operation. If not defined, a
2933 default value of 5 is used.
2937 Timeout waiting for an ARP reply in milliseconds.
2941 Timeout in milliseconds used in NFS protocol.
2942 If you encounter "ERROR: Cannot umount" in nfs command,
2943 try longer timeout such as
2944 #define CONFIG_NFS_TIMEOUT 10000UL
2946 - Command Interpreter:
2947 CONFIG_AUTO_COMPLETE
2949 Enable auto completion of commands using TAB.
2951 CONFIG_SYS_HUSH_PARSER
2953 Define this variable to enable the "hush" shell (from
2954 Busybox) as command line interpreter, thus enabling
2955 powerful command line syntax like
2956 if...then...else...fi conditionals or `&&' and '||'
2957 constructs ("shell scripts").
2959 If undefined, you get the old, much simpler behaviour
2960 with a somewhat smaller memory footprint.
2963 CONFIG_SYS_PROMPT_HUSH_PS2
2965 This defines the secondary prompt string, which is
2966 printed when the command interpreter needs more input
2967 to complete a command. Usually "> ".
2971 In the current implementation, the local variables
2972 space and global environment variables space are
2973 separated. Local variables are those you define by
2974 simply typing `name=value'. To access a local
2975 variable later on, you have write `$name' or
2976 `${name}'; to execute the contents of a variable
2977 directly type `$name' at the command prompt.
2979 Global environment variables are those you use
2980 setenv/printenv to work with. To run a command stored
2981 in such a variable, you need to use the run command,
2982 and you must not use the '$' sign to access them.
2984 To store commands and special characters in a
2985 variable, please use double quotation marks
2986 surrounding the whole text of the variable, instead
2987 of the backslashes before semicolons and special
2990 - Commandline Editing and History:
2991 CONFIG_CMDLINE_EDITING
2993 Enable editing and History functions for interactive
2994 commandline input operations
2996 - Default Environment:
2997 CONFIG_EXTRA_ENV_SETTINGS
2999 Define this to contain any number of null terminated
3000 strings (variable = value pairs) that will be part of
3001 the default environment compiled into the boot image.
3003 For example, place something like this in your
3004 board's config file:
3006 #define CONFIG_EXTRA_ENV_SETTINGS \
3010 Warning: This method is based on knowledge about the
3011 internal format how the environment is stored by the
3012 U-Boot code. This is NOT an official, exported
3013 interface! Although it is unlikely that this format
3014 will change soon, there is no guarantee either.
3015 You better know what you are doing here.
3017 Note: overly (ab)use of the default environment is
3018 discouraged. Make sure to check other ways to preset
3019 the environment like the "source" command or the
3022 CONFIG_ENV_VARS_UBOOT_CONFIG
3024 Define this in order to add variables describing the
3025 U-Boot build configuration to the default environment.
3026 These will be named arch, cpu, board, vendor, and soc.
3028 Enabling this option will cause the following to be defined:
3036 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3038 Define this in order to add variables describing certain
3039 run-time determined information about the hardware to the
3040 environment. These will be named board_name, board_rev.
3042 CONFIG_DELAY_ENVIRONMENT
3044 Normally the environment is loaded when the board is
3045 intialised so that it is available to U-Boot. This inhibits
3046 that so that the environment is not available until
3047 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3048 this is instead controlled by the value of
3049 /config/load-environment.
3051 - DataFlash Support:
3052 CONFIG_HAS_DATAFLASH
3054 Defining this option enables DataFlash features and
3055 allows to read/write in Dataflash via the standard
3058 - Serial Flash support
3061 Defining this option enables SPI flash commands
3062 'sf probe/read/write/erase/update'.
3064 Usage requires an initial 'probe' to define the serial
3065 flash parameters, followed by read/write/erase/update
3068 The following defaults may be provided by the platform
3069 to handle the common case when only a single serial
3070 flash is present on the system.
3072 CONFIG_SF_DEFAULT_BUS Bus identifier
3073 CONFIG_SF_DEFAULT_CS Chip-select
3074 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3075 CONFIG_SF_DEFAULT_SPEED in Hz
3079 Define this option to include a destructive SPI flash
3082 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3084 Define this option to use the Bank addr/Extended addr
3085 support on SPI flashes which has size > 16Mbytes.
3087 CONFIG_SF_DUAL_FLASH Dual flash memories
3089 Define this option to use dual flash support where two flash
3090 memories can be connected with a given cs line.
3091 currently Xilinx Zynq qspi support these type of connections.
3093 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3094 enable the W#/Vpp signal to disable writing to the status
3095 register on ST MICRON flashes like the N25Q128.
3096 The status register write enable/disable bit, combined with
3097 the W#/VPP signal provides hardware data protection for the
3098 device as follows: When the enable/disable bit is set to 1,
3099 and the W#/VPP signal is driven LOW, the status register
3100 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3101 operation will not execute. The only way to exit this
3102 hardware-protected mode is to drive W#/VPP HIGH.
3104 - SystemACE Support:
3107 Adding this option adds support for Xilinx SystemACE
3108 chips attached via some sort of local bus. The address
3109 of the chip must also be defined in the
3110 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3112 #define CONFIG_SYSTEMACE
3113 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3115 When SystemACE support is added, the "ace" device type
3116 becomes available to the fat commands, i.e. fatls.
3118 - TFTP Fixed UDP Port:
3121 If this is defined, the environment variable tftpsrcp
3122 is used to supply the TFTP UDP source port value.
3123 If tftpsrcp isn't defined, the normal pseudo-random port
3124 number generator is used.
3126 Also, the environment variable tftpdstp is used to supply
3127 the TFTP UDP destination port value. If tftpdstp isn't
3128 defined, the normal port 69 is used.
3130 The purpose for tftpsrcp is to allow a TFTP server to
3131 blindly start the TFTP transfer using the pre-configured
3132 target IP address and UDP port. This has the effect of
3133 "punching through" the (Windows XP) firewall, allowing
3134 the remainder of the TFTP transfer to proceed normally.
3135 A better solution is to properly configure the firewall,
3136 but sometimes that is not allowed.
3141 This enables a generic 'hash' command which can produce
3142 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3146 Enable the hash verify command (hash -v). This adds to code
3149 CONFIG_SHA1 - support SHA1 hashing
3150 CONFIG_SHA256 - support SHA256 hashing
3152 Note: There is also a sha1sum command, which should perhaps
3153 be deprecated in favour of 'hash sha1'.
3155 - Freescale i.MX specific commands:
3156 CONFIG_CMD_HDMIDETECT
3157 This enables 'hdmidet' command which returns true if an
3158 HDMI monitor is detected. This command is i.MX 6 specific.
3161 This enables the 'bmode' (bootmode) command for forcing
3162 a boot from specific media.
3164 This is useful for forcing the ROM's usb downloader to
3165 activate upon a watchdog reset which is nice when iterating
3166 on U-Boot. Using the reset button or running bmode normal
3167 will set it back to normal. This command currently
3168 supports i.MX53 and i.MX6.
3173 This enables the RSA algorithm used for FIT image verification
3174 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3176 The signing part is build into mkimage regardless of this
3179 - bootcount support:
3180 CONFIG_BOOTCOUNT_LIMIT
3182 This enables the bootcounter support, see:
3183 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3186 enable special bootcounter support on at91sam9xe based boards.
3188 enable special bootcounter support on blackfin based boards.
3190 enable special bootcounter support on da850 based boards.
3191 CONFIG_BOOTCOUNT_RAM
3192 enable support for the bootcounter in RAM
3193 CONFIG_BOOTCOUNT_I2C
3194 enable support for the bootcounter on an i2c (like RTC) device.
3195 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3196 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3198 CONFIG_BOOTCOUNT_ALEN = address len
3200 - Show boot progress:
3201 CONFIG_SHOW_BOOT_PROGRESS
3203 Defining this option allows to add some board-
3204 specific code (calling a user-provided function
3205 "show_boot_progress(int)") that enables you to show
3206 the system's boot progress on some display (for
3207 example, some LED's) on your board. At the moment,
3208 the following checkpoints are implemented:
3210 - Detailed boot stage timing
3212 Define this option to get detailed timing of each stage
3213 of the boot process.
3215 CONFIG_BOOTSTAGE_USER_COUNT
3216 This is the number of available user bootstage records.
3217 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3218 a new ID will be allocated from this stash. If you exceed
3219 the limit, recording will stop.
3221 CONFIG_BOOTSTAGE_REPORT
3222 Define this to print a report before boot, similar to this:
3224 Timer summary in microseconds:
3227 3,575,678 3,575,678 board_init_f start
3228 3,575,695 17 arch_cpu_init A9
3229 3,575,777 82 arch_cpu_init done
3230 3,659,598 83,821 board_init_r start
3231 3,910,375 250,777 main_loop
3232 29,916,167 26,005,792 bootm_start
3233 30,361,327 445,160 start_kernel
3235 CONFIG_CMD_BOOTSTAGE
3236 Add a 'bootstage' command which supports printing a report
3237 and un/stashing of bootstage data.
3239 CONFIG_BOOTSTAGE_FDT
3240 Stash the bootstage information in the FDT. A root 'bootstage'
3241 node is created with each bootstage id as a child. Each child
3242 has a 'name' property and either 'mark' containing the
3243 mark time in microsecond, or 'accum' containing the
3244 accumulated time for that bootstage id in microseconds.
3249 name = "board_init_f";
3258 Code in the Linux kernel can find this in /proc/devicetree.
3260 Legacy uImage format:
3263 1 common/cmd_bootm.c before attempting to boot an image
3264 -1 common/cmd_bootm.c Image header has bad magic number
3265 2 common/cmd_bootm.c Image header has correct magic number
3266 -2 common/cmd_bootm.c Image header has bad checksum
3267 3 common/cmd_bootm.c Image header has correct checksum
3268 -3 common/cmd_bootm.c Image data has bad checksum
3269 4 common/cmd_bootm.c Image data has correct checksum
3270 -4 common/cmd_bootm.c Image is for unsupported architecture
3271 5 common/cmd_bootm.c Architecture check OK
3272 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3273 6 common/cmd_bootm.c Image Type check OK
3274 -6 common/cmd_bootm.c gunzip uncompression error
3275 -7 common/cmd_bootm.c Unimplemented compression type
3276 7 common/cmd_bootm.c Uncompression OK
3277 8 common/cmd_bootm.c No uncompress/copy overwrite error
3278 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3280 9 common/image.c Start initial ramdisk verification
3281 -10 common/image.c Ramdisk header has bad magic number
3282 -11 common/image.c Ramdisk header has bad checksum
3283 10 common/image.c Ramdisk header is OK
3284 -12 common/image.c Ramdisk data has bad checksum
3285 11 common/image.c Ramdisk data has correct checksum
3286 12 common/image.c Ramdisk verification complete, start loading
3287 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3288 13 common/image.c Start multifile image verification
3289 14 common/image.c No initial ramdisk, no multifile, continue.
3291 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3293 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3294 -31 post/post.c POST test failed, detected by post_output_backlog()
3295 -32 post/post.c POST test failed, detected by post_run_single()
3297 34 common/cmd_doc.c before loading a Image from a DOC device
3298 -35 common/cmd_doc.c Bad usage of "doc" command
3299 35 common/cmd_doc.c correct usage of "doc" command
3300 -36 common/cmd_doc.c No boot device
3301 36 common/cmd_doc.c correct boot device
3302 -37 common/cmd_doc.c Unknown Chip ID on boot device
3303 37 common/cmd_doc.c correct chip ID found, device available
3304 -38 common/cmd_doc.c Read Error on boot device
3305 38 common/cmd_doc.c reading Image header from DOC device OK
3306 -39 common/cmd_doc.c Image header has bad magic number
3307 39 common/cmd_doc.c Image header has correct magic number
3308 -40 common/cmd_doc.c Error reading Image from DOC device
3309 40 common/cmd_doc.c Image header has correct magic number
3310 41 common/cmd_ide.c before loading a Image from a IDE device
3311 -42 common/cmd_ide.c Bad usage of "ide" command
3312 42 common/cmd_ide.c correct usage of "ide" command
3313 -43 common/cmd_ide.c No boot device
3314 43 common/cmd_ide.c boot device found
3315 -44 common/cmd_ide.c Device not available
3316 44 common/cmd_ide.c Device available
3317 -45 common/cmd_ide.c wrong partition selected
3318 45 common/cmd_ide.c partition selected
3319 -46 common/cmd_ide.c Unknown partition table
3320 46 common/cmd_ide.c valid partition table found
3321 -47 common/cmd_ide.c Invalid partition type
3322 47 common/cmd_ide.c correct partition type
3323 -48 common/cmd_ide.c Error reading Image Header on boot device
3324 48 common/cmd_ide.c reading Image Header from IDE device OK
3325 -49 common/cmd_ide.c Image header has bad magic number
3326 49 common/cmd_ide.c Image header has correct magic number
3327 -50 common/cmd_ide.c Image header has bad checksum
3328 50 common/cmd_ide.c Image header has correct checksum
3329 -51 common/cmd_ide.c Error reading Image from IDE device
3330 51 common/cmd_ide.c reading Image from IDE device OK
3331 52 common/cmd_nand.c before loading a Image from a NAND device
3332 -53 common/cmd_nand.c Bad usage of "nand" command
3333 53 common/cmd_nand.c correct usage of "nand" command
3334 -54 common/cmd_nand.c No boot device
3335 54 common/cmd_nand.c boot device found
3336 -55 common/cmd_nand.c Unknown Chip ID on boot device
3337 55 common/cmd_nand.c correct chip ID found, device available
3338 -56 common/cmd_nand.c Error reading Image Header on boot device
3339 56 common/cmd_nand.c reading Image Header from NAND device OK
3340 -57 common/cmd_nand.c Image header has bad magic number
3341 57 common/cmd_nand.c Image header has correct magic number
3342 -58 common/cmd_nand.c Error reading Image from NAND device
3343 58 common/cmd_nand.c reading Image from NAND device OK
3345 -60 common/env_common.c Environment has a bad CRC, using default
3347 64 net/eth.c starting with Ethernet configuration.
3348 -64 net/eth.c no Ethernet found.
3349 65 net/eth.c Ethernet found.
3351 -80 common/cmd_net.c usage wrong
3352 80 common/cmd_net.c before calling NetLoop()
3353 -81 common/cmd_net.c some error in NetLoop() occurred
3354 81 common/cmd_net.c NetLoop() back without error
3355 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3356 82 common/cmd_net.c trying automatic boot
3357 83 common/cmd_net.c running "source" command
3358 -83 common/cmd_net.c some error in automatic boot or "source" command
3359 84 common/cmd_net.c end without errors
3364 100 common/cmd_bootm.c Kernel FIT Image has correct format
3365 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3366 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3367 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3368 102 common/cmd_bootm.c Kernel unit name specified
3369 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3370 103 common/cmd_bootm.c Found configuration node
3371 104 common/cmd_bootm.c Got kernel subimage node offset
3372 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3373 105 common/cmd_bootm.c Kernel subimage hash verification OK
3374 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3375 106 common/cmd_bootm.c Architecture check OK
3376 -106 common/cmd_bootm.c Kernel subimage has wrong type
3377 107 common/cmd_bootm.c Kernel subimage type OK
3378 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3379 108 common/cmd_bootm.c Got kernel subimage data/size
3380 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3381 -109 common/cmd_bootm.c Can't get kernel subimage type
3382 -110 common/cmd_bootm.c Can't get kernel subimage comp
3383 -111 common/cmd_bootm.c Can't get kernel subimage os
3384 -112 common/cmd_bootm.c Can't get kernel subimage load address
3385 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3387 120 common/image.c Start initial ramdisk verification
3388 -120 common/image.c Ramdisk FIT image has incorrect format
3389 121 common/image.c Ramdisk FIT image has correct format
3390 122 common/image.c No ramdisk subimage unit name, using configuration
3391 -122 common/image.c Can't get configuration for ramdisk subimage
3392 123 common/image.c Ramdisk unit name specified
3393 -124 common/image.c Can't get ramdisk subimage node offset
3394 125 common/image.c Got ramdisk subimage node offset
3395 -125 common/image.c Ramdisk subimage hash verification failed
3396 126 common/image.c Ramdisk subimage hash verification OK
3397 -126 common/image.c Ramdisk subimage for unsupported architecture
3398 127 common/image.c Architecture check OK
3399 -127 common/image.c Can't get ramdisk subimage data/size
3400 128 common/image.c Got ramdisk subimage data/size
3401 129 common/image.c Can't get ramdisk load address
3402 -129 common/image.c Got ramdisk load address
3404 -130 common/cmd_doc.c Incorrect FIT image format
3405 131 common/cmd_doc.c FIT image format OK
3407 -140 common/cmd_ide.c Incorrect FIT image format
3408 141 common/cmd_ide.c FIT image format OK
3410 -150 common/cmd_nand.c Incorrect FIT image format
3411 151 common/cmd_nand.c FIT image format OK
3413 - legacy image format:
3414 CONFIG_IMAGE_FORMAT_LEGACY
3415 enables the legacy image format support in U-Boot.
3418 enabled if CONFIG_FIT_SIGNATURE is not defined.
3420 CONFIG_DISABLE_IMAGE_LEGACY
3421 disable the legacy image format
3423 This define is introduced, as the legacy image format is
3424 enabled per default for backward compatibility.
3426 - FIT image support:
3428 Enable support for the FIT uImage format.
3430 CONFIG_FIT_BEST_MATCH
3431 When no configuration is explicitly selected, default to the
3432 one whose fdt's compatibility field best matches that of
3433 U-Boot itself. A match is considered "best" if it matches the
3434 most specific compatibility entry of U-Boot's fdt's root node.
3435 The order of entries in the configuration's fdt is ignored.
3437 CONFIG_FIT_SIGNATURE
3438 This option enables signature verification of FIT uImages,
3439 using a hash signed and verified using RSA. See
3440 doc/uImage.FIT/signature.txt for more details.
3442 WARNING: When relying on signed FIT images with required
3443 signature check the legacy image format is default
3444 disabled. If a board need legacy image format support
3445 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3447 CONFIG_FIT_DISABLE_SHA256
3448 Supporting SHA256 hashes has quite an impact on binary size.
3449 For constrained systems sha256 hash support can be disabled
3452 - Standalone program support:
3453 CONFIG_STANDALONE_LOAD_ADDR
3455 This option defines a board specific value for the
3456 address where standalone program gets loaded, thus
3457 overwriting the architecture dependent default
3460 - Frame Buffer Address:
3463 Define CONFIG_FB_ADDR if you want to use specific
3464 address for frame buffer. This is typically the case
3465 when using a graphics controller has separate video
3466 memory. U-Boot will then place the frame buffer at
3467 the given address instead of dynamically reserving it
3468 in system RAM by calling lcd_setmem(), which grabs
3469 the memory for the frame buffer depending on the
3470 configured panel size.
3472 Please see board_init_f function.
3474 - Automatic software updates via TFTP server
3476 CONFIG_UPDATE_TFTP_CNT_MAX
3477 CONFIG_UPDATE_TFTP_MSEC_MAX
3479 These options enable and control the auto-update feature;
3480 for a more detailed description refer to doc/README.update.
3482 - MTD Support (mtdparts command, UBI support)
3485 Adds the MTD device infrastructure from the Linux kernel.
3486 Needed for mtdparts command support.
3488 CONFIG_MTD_PARTITIONS
3490 Adds the MTD partitioning infrastructure from the Linux
3491 kernel. Needed for UBI support.
3493 CONFIG_MTD_NAND_VERIFY_WRITE
3494 verify if the written data is correct reread.
3499 Adds commands for interacting with MTD partitions formatted
3500 with the UBI flash translation layer
3502 Requires also defining CONFIG_RBTREE
3504 CONFIG_UBI_SILENCE_MSG
3506 Make the verbose messages from UBI stop printing. This leaves
3507 warnings and errors enabled.
3510 CONFIG_MTD_UBI_WL_THRESHOLD
3511 This parameter defines the maximum difference between the highest
3512 erase counter value and the lowest erase counter value of eraseblocks
3513 of UBI devices. When this threshold is exceeded, UBI starts performing
3514 wear leveling by means of moving data from eraseblock with low erase
3515 counter to eraseblocks with high erase counter.
3517 The default value should be OK for SLC NAND flashes, NOR flashes and
3518 other flashes which have eraseblock life-cycle 100000 or more.
3519 However, in case of MLC NAND flashes which typically have eraseblock
3520 life-cycle less than 10000, the threshold should be lessened (e.g.,
3521 to 128 or 256, although it does not have to be power of 2).
3525 CONFIG_MTD_UBI_BEB_LIMIT
3526 This option specifies the maximum bad physical eraseblocks UBI
3527 expects on the MTD device (per 1024 eraseblocks). If the
3528 underlying flash does not admit of bad eraseblocks (e.g. NOR
3529 flash), this value is ignored.
3531 NAND datasheets often specify the minimum and maximum NVM
3532 (Number of Valid Blocks) for the flashes' endurance lifetime.
3533 The maximum expected bad eraseblocks per 1024 eraseblocks
3534 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3535 which gives 20 for most NANDs (MaxNVB is basically the total
3536 count of eraseblocks on the chip).
3538 To put it differently, if this value is 20, UBI will try to
3539 reserve about 1.9% of physical eraseblocks for bad blocks
3540 handling. And that will be 1.9% of eraseblocks on the entire
3541 NAND chip, not just the MTD partition UBI attaches. This means
3542 that if you have, say, a NAND flash chip admits maximum 40 bad
3543 eraseblocks, and it is split on two MTD partitions of the same
3544 size, UBI will reserve 40 eraseblocks when attaching a
3549 CONFIG_MTD_UBI_FASTMAP
3550 Fastmap is a mechanism which allows attaching an UBI device
3551 in nearly constant time. Instead of scanning the whole MTD device it
3552 only has to locate a checkpoint (called fastmap) on the device.
3553 The on-flash fastmap contains all information needed to attach
3554 the device. Using fastmap makes only sense on large devices where
3555 attaching by scanning takes long. UBI will not automatically install
3556 a fastmap on old images, but you can set the UBI parameter
3557 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3558 that fastmap-enabled images are still usable with UBI implementations
3559 without fastmap support. On typical flash devices the whole fastmap
3560 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3562 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3563 Set this parameter to enable fastmap automatically on images
3570 Adds commands for interacting with UBI volumes formatted as
3571 UBIFS. UBIFS is read-only in u-boot.
3573 Requires UBI support as well as CONFIG_LZO
3575 CONFIG_UBIFS_SILENCE_MSG
3577 Make the verbose messages from UBIFS stop printing. This leaves
3578 warnings and errors enabled.
3582 Enable building of SPL globally.
3585 LDSCRIPT for linking the SPL binary.
3587 CONFIG_SPL_MAX_FOOTPRINT
3588 Maximum size in memory allocated to the SPL, BSS included.
3589 When defined, the linker checks that the actual memory
3590 used by SPL from _start to __bss_end does not exceed it.
3591 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3592 must not be both defined at the same time.
3595 Maximum size of the SPL image (text, data, rodata, and
3596 linker lists sections), BSS excluded.
3597 When defined, the linker checks that the actual size does
3600 CONFIG_SPL_TEXT_BASE
3601 TEXT_BASE for linking the SPL binary.
3603 CONFIG_SPL_RELOC_TEXT_BASE
3604 Address to relocate to. If unspecified, this is equal to
3605 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3607 CONFIG_SPL_BSS_START_ADDR
3608 Link address for the BSS within the SPL binary.
3610 CONFIG_SPL_BSS_MAX_SIZE
3611 Maximum size in memory allocated to the SPL BSS.
3612 When defined, the linker checks that the actual memory used
3613 by SPL from __bss_start to __bss_end does not exceed it.
3614 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3615 must not be both defined at the same time.
3618 Adress of the start of the stack SPL will use
3620 CONFIG_SPL_RELOC_STACK
3621 Adress of the start of the stack SPL will use after
3622 relocation. If unspecified, this is equal to
3625 CONFIG_SYS_SPL_MALLOC_START
3626 Starting address of the malloc pool used in SPL.
3628 CONFIG_SYS_SPL_MALLOC_SIZE
3629 The size of the malloc pool used in SPL.
3631 CONFIG_SPL_FRAMEWORK
3632 Enable the SPL framework under common/. This framework
3633 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3634 NAND loading of the Linux Kernel.
3637 Enable booting directly to an OS from SPL.
3638 See also: doc/README.falcon
3640 CONFIG_SPL_DISPLAY_PRINT
3641 For ARM, enable an optional function to print more information
3642 about the running system.
3644 CONFIG_SPL_INIT_MINIMAL
3645 Arch init code should be built for a very small image
3647 CONFIG_SPL_LIBCOMMON_SUPPORT
3648 Support for common/libcommon.o in SPL binary
3650 CONFIG_SPL_LIBDISK_SUPPORT
3651 Support for disk/libdisk.o in SPL binary
3653 CONFIG_SPL_I2C_SUPPORT
3654 Support for drivers/i2c/libi2c.o in SPL binary
3656 CONFIG_SPL_GPIO_SUPPORT
3657 Support for drivers/gpio/libgpio.o in SPL binary
3659 CONFIG_SPL_MMC_SUPPORT
3660 Support for drivers/mmc/libmmc.o in SPL binary
3662 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3663 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3664 CONFIG_SYS_MMC_SD_FS_BOOT_PARTITION
3665 Address, size and partition on the MMC to load U-Boot from
3666 when the MMC is being used in raw mode.
3668 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3669 Sector to load kernel uImage from when MMC is being
3670 used in raw mode (for Falcon mode)
3672 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3673 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3674 Sector and number of sectors to load kernel argument
3675 parameters from when MMC is being used in raw mode
3678 CONFIG_SPL_FAT_SUPPORT
3679 Support for fs/fat/libfat.o in SPL binary
3681 CONFIG_SPL_EXT_SUPPORT
3682 Support for EXT filesystem in SPL binary
3684 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3685 Filename to read to load U-Boot when reading from filesystem
3687 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3688 Filename to read to load kernel uImage when reading
3689 from filesystem (for Falcon mode)
3691 CONFIG_SPL_FS_LOAD_ARGS_NAME
3692 Filename to read to load kernel argument parameters
3693 when reading from filesystem (for Falcon mode)
3695 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3696 Set this for NAND SPL on PPC mpc83xx targets, so that
3697 start.S waits for the rest of the SPL to load before
3698 continuing (the hardware starts execution after just
3699 loading the first page rather than the full 4K).
3701 CONFIG_SPL_SKIP_RELOCATE
3702 Avoid SPL relocation
3704 CONFIG_SPL_NAND_BASE
3705 Include nand_base.c in the SPL. Requires
3706 CONFIG_SPL_NAND_DRIVERS.
3708 CONFIG_SPL_NAND_DRIVERS
3709 SPL uses normal NAND drivers, not minimal drivers.
3712 Include standard software ECC in the SPL
3714 CONFIG_SPL_NAND_SIMPLE
3715 Support for NAND boot using simple NAND drivers that
3716 expose the cmd_ctrl() interface.
3718 CONFIG_SPL_MTD_SUPPORT
3719 Support for the MTD subsystem within SPL. Useful for
3720 environment on NAND support within SPL.
3722 CONFIG_SPL_NAND_RAW_ONLY
3723 Support to boot only raw u-boot.bin images. Use this only
3724 if you need to save space.
3726 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3727 Set for the SPL on PPC mpc8xxx targets, support for
3728 drivers/ddr/fsl/libddr.o in SPL binary.
3730 CONFIG_SPL_COMMON_INIT_DDR
3731 Set for common ddr init with serial presence detect in
3734 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3735 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3736 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3737 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3738 CONFIG_SYS_NAND_ECCBYTES
3739 Defines the size and behavior of the NAND that SPL uses
3742 CONFIG_SPL_NAND_BOOT
3743 Add support NAND boot
3745 CONFIG_SYS_NAND_U_BOOT_OFFS
3746 Location in NAND to read U-Boot from
3748 CONFIG_SYS_NAND_U_BOOT_DST
3749 Location in memory to load U-Boot to
3751 CONFIG_SYS_NAND_U_BOOT_SIZE
3752 Size of image to load
3754 CONFIG_SYS_NAND_U_BOOT_START
3755 Entry point in loaded image to jump to
3757 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3758 Define this if you need to first read the OOB and then the
3759 data. This is used for example on davinci plattforms.
3761 CONFIG_SPL_OMAP3_ID_NAND
3762 Support for an OMAP3-specific set of functions to return the
3763 ID and MFR of the first attached NAND chip, if present.
3765 CONFIG_SPL_SERIAL_SUPPORT
3766 Support for drivers/serial/libserial.o in SPL binary
3768 CONFIG_SPL_SPI_FLASH_SUPPORT
3769 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3771 CONFIG_SPL_SPI_SUPPORT
3772 Support for drivers/spi/libspi.o in SPL binary
3774 CONFIG_SPL_RAM_DEVICE
3775 Support for running image already present in ram, in SPL binary
3777 CONFIG_SPL_LIBGENERIC_SUPPORT
3778 Support for lib/libgeneric.o in SPL binary
3780 CONFIG_SPL_ENV_SUPPORT
3781 Support for the environment operating in SPL binary
3783 CONFIG_SPL_NET_SUPPORT
3784 Support for the net/libnet.o in SPL binary.
3785 It conflicts with SPL env from storage medium specified by
3786 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3789 Image offset to which the SPL should be padded before appending
3790 the SPL payload. By default, this is defined as
3791 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3792 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3793 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3796 Final target image containing SPL and payload. Some SPLs
3797 use an arch-specific makefile fragment instead, for
3798 example if more than one image needs to be produced.
3800 CONFIG_FIT_SPL_PRINT
3801 Printing information about a FIT image adds quite a bit of
3802 code to SPL. So this is normally disabled in SPL. Use this
3803 option to re-enable it. This will affect the output of the
3804 bootm command when booting a FIT image.
3808 Enable building of TPL globally.
3811 Image offset to which the TPL should be padded before appending
3812 the TPL 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.
3820 [so far only for SMDK2400 boards]
3822 - Modem support enable:
3823 CONFIG_MODEM_SUPPORT
3825 - RTS/CTS Flow control enable:
3828 - Modem debug support:
3829 CONFIG_MODEM_SUPPORT_DEBUG
3831 Enables debugging stuff (char screen[1024], dbg())
3832 for modem support. Useful only with BDI2000.
3834 - Interrupt support (PPC):
3836 There are common interrupt_init() and timer_interrupt()
3837 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3838 for CPU specific initialization. interrupt_init_cpu()
3839 should set decrementer_count to appropriate value. If
3840 CPU resets decrementer automatically after interrupt
3841 (ppc4xx) it should set decrementer_count to zero.
3842 timer_interrupt() calls timer_interrupt_cpu() for CPU
3843 specific handling. If board has watchdog / status_led
3844 / other_activity_monitor it works automatically from
3845 general timer_interrupt().
3849 In the target system modem support is enabled when a
3850 specific key (key combination) is pressed during
3851 power-on. Otherwise U-Boot will boot normally
3852 (autoboot). The key_pressed() function is called from
3853 board_init(). Currently key_pressed() is a dummy
3854 function, returning 1 and thus enabling modem
3857 If there are no modem init strings in the
3858 environment, U-Boot proceed to autoboot; the
3859 previous output (banner, info printfs) will be
3862 See also: doc/README.Modem
3864 Board initialization settings:
3865 ------------------------------
3867 During Initialization u-boot calls a number of board specific functions
3868 to allow the preparation of board specific prerequisites, e.g. pin setup
3869 before drivers are initialized. To enable these callbacks the
3870 following configuration macros have to be defined. Currently this is
3871 architecture specific, so please check arch/your_architecture/lib/board.c
3872 typically in board_init_f() and board_init_r().
3874 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3875 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3876 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3877 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3879 Configuration Settings:
3880 -----------------------
3882 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3883 Optionally it can be defined to support 64-bit memory commands.
3885 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3886 undefine this when you're short of memory.
3888 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3889 width of the commands listed in the 'help' command output.
3891 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3892 prompt for user input.
3894 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3896 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3898 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3900 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3901 the application (usually a Linux kernel) when it is
3904 - CONFIG_SYS_BAUDRATE_TABLE:
3905 List of legal baudrate settings for this board.
3907 - CONFIG_SYS_CONSOLE_INFO_QUIET
3908 Suppress display of console information at boot.
3910 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3911 If the board specific function
3912 extern int overwrite_console (void);
3913 returns 1, the stdin, stderr and stdout are switched to the
3914 serial port, else the settings in the environment are used.
3916 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3917 Enable the call to overwrite_console().
3919 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3920 Enable overwrite of previous console environment settings.
3922 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3923 Begin and End addresses of the area used by the
3926 - CONFIG_SYS_ALT_MEMTEST:
3927 Enable an alternate, more extensive memory test.
3929 - CONFIG_SYS_MEMTEST_SCRATCH:
3930 Scratch address used by the alternate memory test
3931 You only need to set this if address zero isn't writeable
3933 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3934 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3935 this specified memory area will get subtracted from the top
3936 (end) of RAM and won't get "touched" at all by U-Boot. By
3937 fixing up gd->ram_size the Linux kernel should gets passed
3938 the now "corrected" memory size and won't touch it either.
3939 This should work for arch/ppc and arch/powerpc. Only Linux
3940 board ports in arch/powerpc with bootwrapper support that
3941 recalculate the memory size from the SDRAM controller setup
3942 will have to get fixed in Linux additionally.
3944 This option can be used as a workaround for the 440EPx/GRx
3945 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3948 WARNING: Please make sure that this value is a multiple of
3949 the Linux page size (normally 4k). If this is not the case,
3950 then the end address of the Linux memory will be located at a
3951 non page size aligned address and this could cause major
3954 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3955 Enable temporary baudrate change while serial download
3957 - CONFIG_SYS_SDRAM_BASE:
3958 Physical start address of SDRAM. _Must_ be 0 here.
3960 - CONFIG_SYS_MBIO_BASE:
3961 Physical start address of Motherboard I/O (if using a
3964 - CONFIG_SYS_FLASH_BASE:
3965 Physical start address of Flash memory.
3967 - CONFIG_SYS_MONITOR_BASE:
3968 Physical start address of boot monitor code (set by
3969 make config files to be same as the text base address
3970 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3971 CONFIG_SYS_FLASH_BASE when booting from flash.
3973 - CONFIG_SYS_MONITOR_LEN:
3974 Size of memory reserved for monitor code, used to
3975 determine _at_compile_time_ (!) if the environment is
3976 embedded within the U-Boot image, or in a separate
3979 - CONFIG_SYS_MALLOC_LEN:
3980 Size of DRAM reserved for malloc() use.
3982 - CONFIG_SYS_MALLOC_F_LEN
3983 Size of the malloc() pool for use before relocation. If
3984 this is defined, then a very simple malloc() implementation
3985 will become available before relocation. The address is just
3986 below the global data, and the stack is moved down to make
3989 This feature allocates regions with increasing addresses
3990 within the region. calloc() is supported, but realloc()
3991 is not available. free() is supported but does nothing.
3992 The memory will be freed (or in fact just forgotton) when
3993 U-Boot relocates itself.
3995 Pre-relocation malloc() is only supported on ARM and sandbox
3996 at present but is fairly easy to enable for other archs.
3998 - CONFIG_SYS_MALLOC_SIMPLE
3999 Provides a simple and small malloc() and calloc() for those
4000 boards which do not use the full malloc in SPL (which is
4001 enabled with CONFIG_SYS_SPL_MALLOC_START).
4003 - CONFIG_SYS_BOOTM_LEN:
4004 Normally compressed uImages are limited to an
4005 uncompressed size of 8 MBytes. If this is not enough,
4006 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4007 to adjust this setting to your needs.
4009 - CONFIG_SYS_BOOTMAPSZ:
4010 Maximum size of memory mapped by the startup code of
4011 the Linux kernel; all data that must be processed by
4012 the Linux kernel (bd_info, boot arguments, FDT blob if
4013 used) must be put below this limit, unless "bootm_low"
4014 environment variable is defined and non-zero. In such case
4015 all data for the Linux kernel must be between "bootm_low"
4016 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4017 variable "bootm_mapsize" will override the value of
4018 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4019 then the value in "bootm_size" will be used instead.
4021 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4022 Enable initrd_high functionality. If defined then the
4023 initrd_high feature is enabled and the bootm ramdisk subcommand
4026 - CONFIG_SYS_BOOT_GET_CMDLINE:
4027 Enables allocating and saving kernel cmdline in space between
4028 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4030 - CONFIG_SYS_BOOT_GET_KBD:
4031 Enables allocating and saving a kernel copy of the bd_info in
4032 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4034 - CONFIG_SYS_MAX_FLASH_BANKS:
4035 Max number of Flash memory banks
4037 - CONFIG_SYS_MAX_FLASH_SECT:
4038 Max number of sectors on a Flash chip
4040 - CONFIG_SYS_FLASH_ERASE_TOUT:
4041 Timeout for Flash erase operations (in ms)
4043 - CONFIG_SYS_FLASH_WRITE_TOUT:
4044 Timeout for Flash write operations (in ms)
4046 - CONFIG_SYS_FLASH_LOCK_TOUT
4047 Timeout for Flash set sector lock bit operation (in ms)
4049 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4050 Timeout for Flash clear lock bits operation (in ms)
4052 - CONFIG_SYS_FLASH_PROTECTION
4053 If defined, hardware flash sectors protection is used
4054 instead of U-Boot software protection.
4056 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4058 Enable TFTP transfers directly to flash memory;
4059 without this option such a download has to be
4060 performed in two steps: (1) download to RAM, and (2)
4061 copy from RAM to flash.
4063 The two-step approach is usually more reliable, since
4064 you can check if the download worked before you erase
4065 the flash, but in some situations (when system RAM is
4066 too limited to allow for a temporary copy of the
4067 downloaded image) this option may be very useful.
4069 - CONFIG_SYS_FLASH_CFI:
4070 Define if the flash driver uses extra elements in the
4071 common flash structure for storing flash geometry.
4073 - CONFIG_FLASH_CFI_DRIVER
4074 This option also enables the building of the cfi_flash driver
4075 in the drivers directory
4077 - CONFIG_FLASH_CFI_MTD
4078 This option enables the building of the cfi_mtd driver
4079 in the drivers directory. The driver exports CFI flash
4082 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4083 Use buffered writes to flash.
4085 - CONFIG_FLASH_SPANSION_S29WS_N
4086 s29ws-n MirrorBit flash has non-standard addresses for buffered
4089 - CONFIG_SYS_FLASH_QUIET_TEST
4090 If this option is defined, the common CFI flash doesn't
4091 print it's warning upon not recognized FLASH banks. This
4092 is useful, if some of the configured banks are only
4093 optionally available.
4095 - CONFIG_FLASH_SHOW_PROGRESS
4096 If defined (must be an integer), print out countdown
4097 digits and dots. Recommended value: 45 (9..1) for 80
4098 column displays, 15 (3..1) for 40 column displays.
4100 - CONFIG_FLASH_VERIFY
4101 If defined, the content of the flash (destination) is compared
4102 against the source after the write operation. An error message
4103 will be printed when the contents are not identical.
4104 Please note that this option is useless in nearly all cases,
4105 since such flash programming errors usually are detected earlier
4106 while unprotecting/erasing/programming. Please only enable
4107 this option if you really know what you are doing.
4109 - CONFIG_SYS_RX_ETH_BUFFER:
4110 Defines the number of Ethernet receive buffers. On some
4111 Ethernet controllers it is recommended to set this value
4112 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4113 buffers can be full shortly after enabling the interface
4114 on high Ethernet traffic.
4115 Defaults to 4 if not defined.
4117 - CONFIG_ENV_MAX_ENTRIES
4119 Maximum number of entries in the hash table that is used
4120 internally to store the environment settings. The default
4121 setting is supposed to be generous and should work in most
4122 cases. This setting can be used to tune behaviour; see
4123 lib/hashtable.c for details.
4125 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4126 - CONFIG_ENV_FLAGS_LIST_STATIC
4127 Enable validation of the values given to environment variables when
4128 calling env set. Variables can be restricted to only decimal,
4129 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4130 the variables can also be restricted to IP address or MAC address.
4132 The format of the list is:
4133 type_attribute = [s|d|x|b|i|m]
4134 access_atribute = [a|r|o|c]
4135 attributes = type_attribute[access_atribute]
4136 entry = variable_name[:attributes]
4139 The type attributes are:
4140 s - String (default)
4143 b - Boolean ([1yYtT|0nNfF])
4147 The access attributes are:
4153 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4154 Define this to a list (string) to define the ".flags"
4155 envirnoment variable in the default or embedded environment.
4157 - CONFIG_ENV_FLAGS_LIST_STATIC
4158 Define this to a list (string) to define validation that
4159 should be done if an entry is not found in the ".flags"
4160 environment variable. To override a setting in the static
4161 list, simply add an entry for the same variable name to the
4164 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4165 If defined, don't allow the -f switch to env set override variable
4168 - CONFIG_SYS_GENERIC_BOARD
4169 This selects the architecture-generic board system instead of the
4170 architecture-specific board files. It is intended to move boards
4171 to this new framework over time. Defining this will disable the
4172 arch/foo/lib/board.c file and use common/board_f.c and
4173 common/board_r.c instead. To use this option your architecture
4174 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4175 its config.mk file). If you find problems enabling this option on
4176 your board please report the problem and send patches!
4178 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4179 This is set by OMAP boards for the max time that reset should
4180 be asserted. See doc/README.omap-reset-time for details on how
4181 the value can be calulated on a given board.
4184 If stdint.h is available with your toolchain you can define this
4185 option to enable it. You can provide option 'USE_STDINT=1' when
4186 building U-Boot to enable this.
4188 The following definitions that deal with the placement and management
4189 of environment data (variable area); in general, we support the
4190 following configurations:
4192 - CONFIG_BUILD_ENVCRC:
4194 Builds up envcrc with the target environment so that external utils
4195 may easily extract it and embed it in final U-Boot images.
4197 - CONFIG_ENV_IS_IN_FLASH:
4199 Define this if the environment is in flash memory.
4201 a) The environment occupies one whole flash sector, which is
4202 "embedded" in the text segment with the U-Boot code. This
4203 happens usually with "bottom boot sector" or "top boot
4204 sector" type flash chips, which have several smaller
4205 sectors at the start or the end. For instance, such a
4206 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4207 such a case you would place the environment in one of the
4208 4 kB sectors - with U-Boot code before and after it. With
4209 "top boot sector" type flash chips, you would put the
4210 environment in one of the last sectors, leaving a gap
4211 between U-Boot and the environment.
4213 - CONFIG_ENV_OFFSET:
4215 Offset of environment data (variable area) to the
4216 beginning of flash memory; for instance, with bottom boot
4217 type flash chips the second sector can be used: the offset
4218 for this sector is given here.
4220 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4224 This is just another way to specify the start address of
4225 the flash sector containing the environment (instead of
4228 - CONFIG_ENV_SECT_SIZE:
4230 Size of the sector containing the environment.
4233 b) Sometimes flash chips have few, equal sized, BIG sectors.
4234 In such a case you don't want to spend a whole sector for
4239 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4240 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4241 of this flash sector for the environment. This saves
4242 memory for the RAM copy of the environment.
4244 It may also save flash memory if you decide to use this
4245 when your environment is "embedded" within U-Boot code,
4246 since then the remainder of the flash sector could be used
4247 for U-Boot code. It should be pointed out that this is
4248 STRONGLY DISCOURAGED from a robustness point of view:
4249 updating the environment in flash makes it always
4250 necessary to erase the WHOLE sector. If something goes
4251 wrong before the contents has been restored from a copy in
4252 RAM, your target system will be dead.
4254 - CONFIG_ENV_ADDR_REDUND
4255 CONFIG_ENV_SIZE_REDUND
4257 These settings describe a second storage area used to hold
4258 a redundant copy of the environment data, so that there is
4259 a valid backup copy in case there is a power failure during
4260 a "saveenv" operation.
4262 BE CAREFUL! Any changes to the flash layout, and some changes to the
4263 source code will make it necessary to adapt <board>/u-boot.lds*
4267 - CONFIG_ENV_IS_IN_NVRAM:
4269 Define this if you have some non-volatile memory device
4270 (NVRAM, battery buffered SRAM) which you want to use for the
4276 These two #defines are used to determine the memory area you
4277 want to use for environment. It is assumed that this memory
4278 can just be read and written to, without any special
4281 BE CAREFUL! The first access to the environment happens quite early
4282 in U-Boot initalization (when we try to get the setting of for the
4283 console baudrate). You *MUST* have mapped your NVRAM area then, or
4286 Please note that even with NVRAM we still use a copy of the
4287 environment in RAM: we could work on NVRAM directly, but we want to
4288 keep settings there always unmodified except somebody uses "saveenv"
4289 to save the current settings.
4292 - CONFIG_ENV_IS_IN_EEPROM:
4294 Use this if you have an EEPROM or similar serial access
4295 device and a driver for it.
4297 - CONFIG_ENV_OFFSET:
4300 These two #defines specify the offset and size of the
4301 environment area within the total memory of your EEPROM.
4303 - CONFIG_SYS_I2C_EEPROM_ADDR:
4304 If defined, specified the chip address of the EEPROM device.
4305 The default address is zero.
4307 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4308 If defined, the number of bits used to address bytes in a
4309 single page in the EEPROM device. A 64 byte page, for example
4310 would require six bits.
4312 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4313 If defined, the number of milliseconds to delay between
4314 page writes. The default is zero milliseconds.
4316 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4317 The length in bytes of the EEPROM memory array address. Note
4318 that this is NOT the chip address length!
4320 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4321 EEPROM chips that implement "address overflow" are ones
4322 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4323 address and the extra bits end up in the "chip address" bit
4324 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4327 Note that we consider the length of the address field to
4328 still be one byte because the extra address bits are hidden
4329 in the chip address.
4331 - CONFIG_SYS_EEPROM_SIZE:
4332 The size in bytes of the EEPROM device.
4334 - CONFIG_ENV_EEPROM_IS_ON_I2C
4335 define this, if you have I2C and SPI activated, and your
4336 EEPROM, which holds the environment, is on the I2C bus.
4338 - CONFIG_I2C_ENV_EEPROM_BUS
4339 if you have an Environment on an EEPROM reached over
4340 I2C muxes, you can define here, how to reach this
4341 EEPROM. For example:
4343 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4345 EEPROM which holds the environment, is reached over
4346 a pca9547 i2c mux with address 0x70, channel 3.
4348 - CONFIG_ENV_IS_IN_DATAFLASH:
4350 Define this if you have a DataFlash memory device which you
4351 want to use for the environment.
4353 - CONFIG_ENV_OFFSET:
4357 These three #defines specify the offset and size of the
4358 environment area within the total memory of your DataFlash placed
4359 at the specified address.
4361 - CONFIG_ENV_IS_IN_SPI_FLASH:
4363 Define this if you have a SPI Flash memory device which you
4364 want to use for the environment.
4366 - CONFIG_ENV_OFFSET:
4369 These two #defines specify the offset and size of the
4370 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4371 aligned to an erase sector boundary.
4373 - CONFIG_ENV_SECT_SIZE:
4375 Define the SPI flash's sector size.
4377 - CONFIG_ENV_OFFSET_REDUND (optional):
4379 This setting describes a second storage area of CONFIG_ENV_SIZE
4380 size used to hold a redundant copy of the environment data, so
4381 that there is a valid backup copy in case there is a power failure
4382 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4383 aligned to an erase sector boundary.
4385 - CONFIG_ENV_SPI_BUS (optional):
4386 - CONFIG_ENV_SPI_CS (optional):
4388 Define the SPI bus and chip select. If not defined they will be 0.
4390 - CONFIG_ENV_SPI_MAX_HZ (optional):
4392 Define the SPI max work clock. If not defined then use 1MHz.
4394 - CONFIG_ENV_SPI_MODE (optional):
4396 Define the SPI work mode. If not defined then use SPI_MODE_3.
4398 - CONFIG_ENV_IS_IN_REMOTE:
4400 Define this if you have a remote memory space which you
4401 want to use for the local device's environment.
4406 These two #defines specify the address and size of the
4407 environment area within the remote memory space. The
4408 local device can get the environment from remote memory
4409 space by SRIO or PCIE links.
4411 BE CAREFUL! For some special cases, the local device can not use
4412 "saveenv" command. For example, the local device will get the
4413 environment stored in a remote NOR flash by SRIO or PCIE link,
4414 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4416 - CONFIG_ENV_IS_IN_NAND:
4418 Define this if you have a NAND device which you want to use
4419 for the environment.
4421 - CONFIG_ENV_OFFSET:
4424 These two #defines specify the offset and size of the environment
4425 area within the first NAND device. CONFIG_ENV_OFFSET must be
4426 aligned to an erase block boundary.
4428 - CONFIG_ENV_OFFSET_REDUND (optional):
4430 This setting describes a second storage area of CONFIG_ENV_SIZE
4431 size used to hold a redundant copy of the environment data, so
4432 that there is a valid backup copy in case there is a power failure
4433 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4434 aligned to an erase block boundary.
4436 - CONFIG_ENV_RANGE (optional):
4438 Specifies the length of the region in which the environment
4439 can be written. This should be a multiple of the NAND device's
4440 block size. Specifying a range with more erase blocks than
4441 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4442 the range to be avoided.
4444 - CONFIG_ENV_OFFSET_OOB (optional):
4446 Enables support for dynamically retrieving the offset of the
4447 environment from block zero's out-of-band data. The
4448 "nand env.oob" command can be used to record this offset.
4449 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4450 using CONFIG_ENV_OFFSET_OOB.
4452 - CONFIG_NAND_ENV_DST
4454 Defines address in RAM to which the nand_spl code should copy the
4455 environment. If redundant environment is used, it will be copied to
4456 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4458 - CONFIG_ENV_IS_IN_UBI:
4460 Define this if you have an UBI volume that you want to use for the
4461 environment. This has the benefit of wear-leveling the environment
4462 accesses, which is important on NAND.
4464 - CONFIG_ENV_UBI_PART:
4466 Define this to a string that is the mtd partition containing the UBI.
4468 - CONFIG_ENV_UBI_VOLUME:
4470 Define this to the name of the volume that you want to store the
4473 - CONFIG_ENV_UBI_VOLUME_REDUND:
4475 Define this to the name of another volume to store a second copy of
4476 the environment in. This will enable redundant environments in UBI.
4477 It is assumed that both volumes are in the same MTD partition.
4479 - CONFIG_UBI_SILENCE_MSG
4480 - CONFIG_UBIFS_SILENCE_MSG
4482 You will probably want to define these to avoid a really noisy system
4483 when storing the env in UBI.
4485 - CONFIG_ENV_IS_IN_FAT:
4486 Define this if you want to use the FAT file system for the environment.
4488 - FAT_ENV_INTERFACE:
4490 Define this to a string that is the name of the block device.
4492 - FAT_ENV_DEV_AND_PART:
4494 Define this to a string to specify the partition of the device. It can
4497 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4498 - "D:P": device D partition P. Error occurs if device D has no
4501 - "D" or "D:": device D partition 1 if device D has partition
4502 table, or the whole device D if has no partition
4504 - "D:auto": first partition in device D with bootable flag set.
4505 If none, first valid paratition in device D. If no
4506 partition table then means device D.
4510 It's a string of the FAT file name. This file use to store the
4514 This should be defined. Otherwise it cannot save the envrionment file.
4516 - CONFIG_ENV_IS_IN_MMC:
4518 Define this if you have an MMC device which you want to use for the
4521 - CONFIG_SYS_MMC_ENV_DEV:
4523 Specifies which MMC device the environment is stored in.
4525 - CONFIG_SYS_MMC_ENV_PART (optional):
4527 Specifies which MMC partition the environment is stored in. If not
4528 set, defaults to partition 0, the user area. Common values might be
4529 1 (first MMC boot partition), 2 (second MMC boot partition).
4531 - CONFIG_ENV_OFFSET:
4534 These two #defines specify the offset and size of the environment
4535 area within the specified MMC device.
4537 If offset is positive (the usual case), it is treated as relative to
4538 the start of the MMC partition. If offset is negative, it is treated
4539 as relative to the end of the MMC partition. This can be useful if
4540 your board may be fitted with different MMC devices, which have
4541 different sizes for the MMC partitions, and you always want the
4542 environment placed at the very end of the partition, to leave the
4543 maximum possible space before it, to store other data.
4545 These two values are in units of bytes, but must be aligned to an
4546 MMC sector boundary.
4548 - CONFIG_ENV_OFFSET_REDUND (optional):
4550 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4551 hold a redundant copy of the environment data. This provides a
4552 valid backup copy in case the other copy is corrupted, e.g. due
4553 to a power failure during a "saveenv" operation.
4555 This value may also be positive or negative; this is handled in the
4556 same way as CONFIG_ENV_OFFSET.
4558 This value is also in units of bytes, but must also be aligned to
4559 an MMC sector boundary.
4561 - CONFIG_ENV_SIZE_REDUND (optional):
4563 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4564 set. If this value is set, it must be set to the same value as
4567 - CONFIG_SYS_SPI_INIT_OFFSET
4569 Defines offset to the initial SPI buffer area in DPRAM. The
4570 area is used at an early stage (ROM part) if the environment
4571 is configured to reside in the SPI EEPROM: We need a 520 byte
4572 scratch DPRAM area. It is used between the two initialization
4573 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4574 to be a good choice since it makes it far enough from the
4575 start of the data area as well as from the stack pointer.
4577 Please note that the environment is read-only until the monitor
4578 has been relocated to RAM and a RAM copy of the environment has been
4579 created; also, when using EEPROM you will have to use getenv_f()
4580 until then to read environment variables.
4582 The environment is protected by a CRC32 checksum. Before the monitor
4583 is relocated into RAM, as a result of a bad CRC you will be working
4584 with the compiled-in default environment - *silently*!!! [This is
4585 necessary, because the first environment variable we need is the
4586 "baudrate" setting for the console - if we have a bad CRC, we don't
4587 have any device yet where we could complain.]
4589 Note: once the monitor has been relocated, then it will complain if
4590 the default environment is used; a new CRC is computed as soon as you
4591 use the "saveenv" command to store a valid environment.
4593 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4594 Echo the inverted Ethernet link state to the fault LED.
4596 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4597 also needs to be defined.
4599 - CONFIG_SYS_FAULT_MII_ADDR:
4600 MII address of the PHY to check for the Ethernet link state.
4602 - CONFIG_NS16550_MIN_FUNCTIONS:
4603 Define this if you desire to only have use of the NS16550_init
4604 and NS16550_putc functions for the serial driver located at
4605 drivers/serial/ns16550.c. This option is useful for saving
4606 space for already greatly restricted images, including but not
4607 limited to NAND_SPL configurations.
4609 - CONFIG_DISPLAY_BOARDINFO
4610 Display information about the board that U-Boot is running on
4611 when U-Boot starts up. The board function checkboard() is called
4614 - CONFIG_DISPLAY_BOARDINFO_LATE
4615 Similar to the previous option, but display this information
4616 later, once stdio is running and output goes to the LCD, if
4619 - CONFIG_BOARD_SIZE_LIMIT:
4620 Maximum size of the U-Boot image. When defined, the
4621 build system checks that the actual size does not
4624 Low Level (hardware related) configuration options:
4625 ---------------------------------------------------
4627 - CONFIG_SYS_CACHELINE_SIZE:
4628 Cache Line Size of the CPU.
4630 - CONFIG_SYS_DEFAULT_IMMR:
4631 Default address of the IMMR after system reset.
4633 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4634 and RPXsuper) to be able to adjust the position of
4635 the IMMR register after a reset.
4637 - CONFIG_SYS_CCSRBAR_DEFAULT:
4638 Default (power-on reset) physical address of CCSR on Freescale
4641 - CONFIG_SYS_CCSRBAR:
4642 Virtual address of CCSR. On a 32-bit build, this is typically
4643 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4645 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4646 for cross-platform code that uses that macro instead.
4648 - CONFIG_SYS_CCSRBAR_PHYS:
4649 Physical address of CCSR. CCSR can be relocated to a new
4650 physical address, if desired. In this case, this macro should
4651 be set to that address. Otherwise, it should be set to the
4652 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4653 is typically relocated on 36-bit builds. It is recommended
4654 that this macro be defined via the _HIGH and _LOW macros:
4656 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4657 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4659 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4660 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4661 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4662 used in assembly code, so it must not contain typecasts or
4663 integer size suffixes (e.g. "ULL").
4665 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4666 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4667 used in assembly code, so it must not contain typecasts or
4668 integer size suffixes (e.g. "ULL").
4670 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4671 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4672 forced to a value that ensures that CCSR is not relocated.
4674 - Floppy Disk Support:
4675 CONFIG_SYS_FDC_DRIVE_NUMBER
4677 the default drive number (default value 0)
4679 CONFIG_SYS_ISA_IO_STRIDE
4681 defines the spacing between FDC chipset registers
4684 CONFIG_SYS_ISA_IO_OFFSET
4686 defines the offset of register from address. It
4687 depends on which part of the data bus is connected to
4688 the FDC chipset. (default value 0)
4690 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4691 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4694 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4695 fdc_hw_init() is called at the beginning of the FDC
4696 setup. fdc_hw_init() must be provided by the board
4697 source code. It is used to make hardware dependant
4701 Most IDE controllers were designed to be connected with PCI
4702 interface. Only few of them were designed for AHB interface.
4703 When software is doing ATA command and data transfer to
4704 IDE devices through IDE-AHB controller, some additional
4705 registers accessing to these kind of IDE-AHB controller
4708 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4709 DO NOT CHANGE unless you know exactly what you're
4710 doing! (11-4) [MPC8xx/82xx systems only]
4712 - CONFIG_SYS_INIT_RAM_ADDR:
4714 Start address of memory area that can be used for
4715 initial data and stack; please note that this must be
4716 writable memory that is working WITHOUT special
4717 initialization, i. e. you CANNOT use normal RAM which
4718 will become available only after programming the
4719 memory controller and running certain initialization
4722 U-Boot uses the following memory types:
4723 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4724 - MPC824X: data cache
4725 - PPC4xx: data cache
4727 - CONFIG_SYS_GBL_DATA_OFFSET:
4729 Offset of the initial data structure in the memory
4730 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4731 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4732 data is located at the end of the available space
4733 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4734 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4735 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4736 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4739 On the MPC824X (or other systems that use the data
4740 cache for initial memory) the address chosen for
4741 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4742 point to an otherwise UNUSED address space between
4743 the top of RAM and the start of the PCI space.
4745 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4747 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4749 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4751 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4753 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4755 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4757 - CONFIG_SYS_OR_TIMING_SDRAM:
4760 - CONFIG_SYS_MAMR_PTA:
4761 periodic timer for refresh
4763 - CONFIG_SYS_DER: Debug Event Register (37-47)
4765 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4766 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4767 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4768 CONFIG_SYS_BR1_PRELIM:
4769 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4771 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4772 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4773 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4774 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4776 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4777 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4778 Machine Mode Register and Memory Periodic Timer
4779 Prescaler definitions (SDRAM timing)
4781 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4782 enable I2C microcode relocation patch (MPC8xx);
4783 define relocation offset in DPRAM [DSP2]
4785 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4786 enable SMC microcode relocation patch (MPC8xx);
4787 define relocation offset in DPRAM [SMC1]
4789 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4790 enable SPI microcode relocation patch (MPC8xx);
4791 define relocation offset in DPRAM [SCC4]
4793 - CONFIG_SYS_USE_OSCCLK:
4794 Use OSCM clock mode on MBX8xx board. Be careful,
4795 wrong setting might damage your board. Read
4796 doc/README.MBX before setting this variable!
4798 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4799 Offset of the bootmode word in DPRAM used by post
4800 (Power On Self Tests). This definition overrides
4801 #define'd default value in commproc.h resp.
4804 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4805 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4806 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4807 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4808 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4809 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4810 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4811 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4812 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4814 - CONFIG_PCI_DISABLE_PCIE:
4815 Disable PCI-Express on systems where it is supported but not
4818 - CONFIG_PCI_ENUM_ONLY
4819 Only scan through and get the devices on the busses.
4820 Don't do any setup work, presumably because someone or
4821 something has already done it, and we don't need to do it
4822 a second time. Useful for platforms that are pre-booted
4823 by coreboot or similar.
4825 - CONFIG_PCI_INDIRECT_BRIDGE:
4826 Enable support for indirect PCI bridges.
4829 Chip has SRIO or not
4832 Board has SRIO 1 port available
4835 Board has SRIO 2 port available
4837 - CONFIG_SRIO_PCIE_BOOT_MASTER
4838 Board can support master function for Boot from SRIO and PCIE
4840 - CONFIG_SYS_SRIOn_MEM_VIRT:
4841 Virtual Address of SRIO port 'n' memory region
4843 - CONFIG_SYS_SRIOn_MEM_PHYS:
4844 Physical Address of SRIO port 'n' memory region
4846 - CONFIG_SYS_SRIOn_MEM_SIZE:
4847 Size of SRIO port 'n' memory region
4849 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4850 Defined to tell the NAND controller that the NAND chip is using
4852 Not all NAND drivers use this symbol.
4853 Example of drivers that use it:
4854 - drivers/mtd/nand/ndfc.c
4855 - drivers/mtd/nand/mxc_nand.c
4857 - CONFIG_SYS_NDFC_EBC0_CFG
4858 Sets the EBC0_CFG register for the NDFC. If not defined
4859 a default value will be used.
4862 Get DDR timing information from an I2C EEPROM. Common
4863 with pluggable memory modules such as SODIMMs
4866 I2C address of the SPD EEPROM
4868 - CONFIG_SYS_SPD_BUS_NUM
4869 If SPD EEPROM is on an I2C bus other than the first
4870 one, specify here. Note that the value must resolve
4871 to something your driver can deal with.
4873 - CONFIG_SYS_DDR_RAW_TIMING
4874 Get DDR timing information from other than SPD. Common with
4875 soldered DDR chips onboard without SPD. DDR raw timing
4876 parameters are extracted from datasheet and hard-coded into
4877 header files or board specific files.
4879 - CONFIG_FSL_DDR_INTERACTIVE
4880 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4882 - CONFIG_SYS_83XX_DDR_USES_CS0
4883 Only for 83xx systems. If specified, then DDR should
4884 be configured using CS0 and CS1 instead of CS2 and CS3.
4886 - CONFIG_ETHER_ON_FEC[12]
4887 Define to enable FEC[12] on a 8xx series processor.
4889 - CONFIG_FEC[12]_PHY
4890 Define to the hardcoded PHY address which corresponds
4891 to the given FEC; i. e.
4892 #define CONFIG_FEC1_PHY 4
4893 means that the PHY with address 4 is connected to FEC1
4895 When set to -1, means to probe for first available.
4897 - CONFIG_FEC[12]_PHY_NORXERR
4898 The PHY does not have a RXERR line (RMII only).
4899 (so program the FEC to ignore it).
4902 Enable RMII mode for all FECs.
4903 Note that this is a global option, we can't
4904 have one FEC in standard MII mode and another in RMII mode.
4906 - CONFIG_CRC32_VERIFY
4907 Add a verify option to the crc32 command.
4910 => crc32 -v <address> <count> <crc32>
4912 Where address/count indicate a memory area
4913 and crc32 is the correct crc32 which the
4917 Add the "loopw" memory command. This only takes effect if
4918 the memory commands are activated globally (CONFIG_CMD_MEM).
4921 Add the "mdc" and "mwc" memory commands. These are cyclic
4926 This command will print 4 bytes (10,11,12,13) each 500 ms.
4928 => mwc.l 100 12345678 10
4929 This command will write 12345678 to address 100 all 10 ms.
4931 This only takes effect if the memory commands are activated
4932 globally (CONFIG_CMD_MEM).
4934 - CONFIG_SKIP_LOWLEVEL_INIT
4935 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4936 low level initializations (like setting up the memory
4937 controller) are omitted and/or U-Boot does not
4938 relocate itself into RAM.
4940 Normally this variable MUST NOT be defined. The only
4941 exception is when U-Boot is loaded (to RAM) by some
4942 other boot loader or by a debugger which performs
4943 these initializations itself.
4946 Modifies the behaviour of start.S when compiling a loader
4947 that is executed before the actual U-Boot. E.g. when
4948 compiling a NAND SPL.
4951 Modifies the behaviour of start.S when compiling a loader
4952 that is executed after the SPL and before the actual U-Boot.
4953 It is loaded by the SPL.
4955 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4956 Only for 85xx systems. If this variable is specified, the section
4957 .resetvec is not kept and the section .bootpg is placed in the
4958 previous 4k of the .text section.
4960 - CONFIG_ARCH_MAP_SYSMEM
4961 Generally U-Boot (and in particular the md command) uses
4962 effective address. It is therefore not necessary to regard
4963 U-Boot address as virtual addresses that need to be translated
4964 to physical addresses. However, sandbox requires this, since
4965 it maintains its own little RAM buffer which contains all
4966 addressable memory. This option causes some memory accesses
4967 to be mapped through map_sysmem() / unmap_sysmem().
4969 - CONFIG_USE_ARCH_MEMCPY
4970 CONFIG_USE_ARCH_MEMSET
4971 If these options are used a optimized version of memcpy/memset will
4972 be used if available. These functions may be faster under some
4973 conditions but may increase the binary size.
4975 - CONFIG_X86_RESET_VECTOR
4976 If defined, the x86 reset vector code is included. This is not
4977 needed when U-Boot is running from Coreboot.
4980 Defines the MPU clock speed (in MHz).
4982 NOTE : currently only supported on AM335x platforms.
4984 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4985 Enables the RTC32K OSC on AM33xx based plattforms
4987 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4988 Option to disable subpage write in NAND driver
4989 driver that uses this:
4990 drivers/mtd/nand/davinci_nand.c
4992 Freescale QE/FMAN Firmware Support:
4993 -----------------------------------
4995 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4996 loading of "firmware", which is encoded in the QE firmware binary format.
4997 This firmware often needs to be loaded during U-Boot booting, so macros
4998 are used to identify the storage device (NOR flash, SPI, etc) and the address
5001 - CONFIG_SYS_FMAN_FW_ADDR
5002 The address in the storage device where the FMAN microcode is located. The
5003 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5006 - CONFIG_SYS_QE_FW_ADDR
5007 The address in the storage device where the QE microcode is located. The
5008 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5011 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5012 The maximum possible size of the firmware. The firmware binary format
5013 has a field that specifies the actual size of the firmware, but it
5014 might not be possible to read any part of the firmware unless some
5015 local storage is allocated to hold the entire firmware first.
5017 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5018 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5019 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5020 virtual address in NOR flash.
5022 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5023 Specifies that QE/FMAN firmware is located in NAND flash.
5024 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5026 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5027 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5028 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5030 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5031 Specifies that QE/FMAN firmware is located on the primary SPI
5032 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5034 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5035 Specifies that QE/FMAN firmware is located in the remote (master)
5036 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5037 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5038 window->master inbound window->master LAW->the ucode address in
5039 master's memory space.
5041 Freescale Layerscape Management Complex Firmware Support:
5042 ---------------------------------------------------------
5043 The Freescale Layerscape Management Complex (MC) supports the loading of
5045 This firmware often needs to be loaded during U-Boot booting, so macros
5046 are used to identify the storage device (NOR flash, SPI, etc) and the address
5049 - CONFIG_FSL_MC_ENET
5050 Enable the MC driver for Layerscape SoCs.
5052 - CONFIG_SYS_LS_MC_FW_ADDR
5053 The address in the storage device where the firmware is located. The
5054 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5057 - CONFIG_SYS_LS_MC_FW_LENGTH
5058 The maximum possible size of the firmware. The firmware binary format
5059 has a field that specifies the actual size of the firmware, but it
5060 might not be possible to read any part of the firmware unless some
5061 local storage is allocated to hold the entire firmware first.
5063 - CONFIG_SYS_LS_MC_FW_IN_NOR
5064 Specifies that MC firmware is located in NOR flash, mapped as
5065 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5066 virtual address in NOR flash.
5068 Building the Software:
5069 ======================
5071 Building U-Boot has been tested in several native build environments
5072 and in many different cross environments. Of course we cannot support
5073 all possibly existing versions of cross development tools in all
5074 (potentially obsolete) versions. In case of tool chain problems we
5075 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5076 which is extensively used to build and test U-Boot.
5078 If you are not using a native environment, it is assumed that you
5079 have GNU cross compiling tools available in your path. In this case,
5080 you must set the environment variable CROSS_COMPILE in your shell.
5081 Note that no changes to the Makefile or any other source files are
5082 necessary. For example using the ELDK on a 4xx CPU, please enter:
5084 $ CROSS_COMPILE=ppc_4xx-
5085 $ export CROSS_COMPILE
5087 Note: If you wish to generate Windows versions of the utilities in
5088 the tools directory you can use the MinGW toolchain
5089 (http://www.mingw.org). Set your HOST tools to the MinGW
5090 toolchain and execute 'make tools'. For example:
5092 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5094 Binaries such as tools/mkimage.exe will be created which can
5095 be executed on computers running Windows.
5097 U-Boot is intended to be simple to build. After installing the
5098 sources you must configure U-Boot for one specific board type. This
5103 where "NAME_defconfig" is the name of one of the existing configu-
5104 rations; see boards.cfg for supported names.
5106 Note: for some board special configuration names may exist; check if
5107 additional information is available from the board vendor; for
5108 instance, the TQM823L systems are available without (standard)
5109 or with LCD support. You can select such additional "features"
5110 when choosing the configuration, i. e.
5112 make TQM823L_defconfig
5113 - will configure for a plain TQM823L, i. e. no LCD support
5115 make TQM823L_LCD_defconfig
5116 - will configure for a TQM823L with U-Boot console on LCD
5121 Finally, type "make all", and you should get some working U-Boot
5122 images ready for download to / installation on your system:
5124 - "u-boot.bin" is a raw binary image
5125 - "u-boot" is an image in ELF binary format
5126 - "u-boot.srec" is in Motorola S-Record format
5128 By default the build is performed locally and the objects are saved
5129 in the source directory. One of the two methods can be used to change
5130 this behavior and build U-Boot to some external directory:
5132 1. Add O= to the make command line invocations:
5134 make O=/tmp/build distclean
5135 make O=/tmp/build NAME_defconfig
5136 make O=/tmp/build all
5138 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5140 export KBUILD_OUTPUT=/tmp/build
5145 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5149 Please be aware that the Makefiles assume you are using GNU make, so
5150 for instance on NetBSD you might need to use "gmake" instead of
5154 If the system board that you have is not listed, then you will need
5155 to port U-Boot to your hardware platform. To do this, follow these
5158 1. Add a new configuration option for your board to the toplevel
5159 "boards.cfg" file, using the existing entries as examples.
5160 Follow the instructions there to keep the boards in order.
5161 2. Create a new directory to hold your board specific code. Add any
5162 files you need. In your board directory, you will need at least
5163 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5164 3. Create a new configuration file "include/configs/<board>.h" for
5166 3. If you're porting U-Boot to a new CPU, then also create a new
5167 directory to hold your CPU specific code. Add any files you need.
5168 4. Run "make <board>_defconfig" with your new name.
5169 5. Type "make", and you should get a working "u-boot.srec" file
5170 to be installed on your target system.
5171 6. Debug and solve any problems that might arise.
5172 [Of course, this last step is much harder than it sounds.]
5175 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5176 ==============================================================
5178 If you have modified U-Boot sources (for instance added a new board
5179 or support for new devices, a new CPU, etc.) you are expected to
5180 provide feedback to the other developers. The feedback normally takes
5181 the form of a "patch", i. e. a context diff against a certain (latest
5182 official or latest in the git repository) version of U-Boot sources.
5184 But before you submit such a patch, please verify that your modifi-
5185 cation did not break existing code. At least make sure that *ALL* of
5186 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5187 just run the "MAKEALL" script, which will configure and build U-Boot
5188 for ALL supported system. Be warned, this will take a while. You can
5189 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5190 environment variable to the script, i. e. to use the ELDK cross tools
5193 CROSS_COMPILE=ppc_8xx- MAKEALL
5195 or to build on a native PowerPC system you can type
5197 CROSS_COMPILE=' ' MAKEALL
5199 When using the MAKEALL script, the default behaviour is to build
5200 U-Boot in the source directory. This location can be changed by
5201 setting the BUILD_DIR environment variable. Also, for each target
5202 built, the MAKEALL script saves two log files (<target>.ERR and
5203 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5204 location can be changed by setting the MAKEALL_LOGDIR environment
5205 variable. For example:
5207 export BUILD_DIR=/tmp/build
5208 export MAKEALL_LOGDIR=/tmp/log
5209 CROSS_COMPILE=ppc_8xx- MAKEALL
5211 With the above settings build objects are saved in the /tmp/build,
5212 log files are saved in the /tmp/log and the source tree remains clean
5213 during the whole build process.
5216 See also "U-Boot Porting Guide" below.
5219 Monitor Commands - Overview:
5220 ============================
5222 go - start application at address 'addr'
5223 run - run commands in an environment variable
5224 bootm - boot application image from memory
5225 bootp - boot image via network using BootP/TFTP protocol
5226 bootz - boot zImage from memory
5227 tftpboot- boot image via network using TFTP protocol
5228 and env variables "ipaddr" and "serverip"
5229 (and eventually "gatewayip")
5230 tftpput - upload a file via network using TFTP protocol
5231 rarpboot- boot image via network using RARP/TFTP protocol
5232 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5233 loads - load S-Record file over serial line
5234 loadb - load binary file over serial line (kermit mode)
5236 mm - memory modify (auto-incrementing)
5237 nm - memory modify (constant address)
5238 mw - memory write (fill)
5240 cmp - memory compare
5241 crc32 - checksum calculation
5242 i2c - I2C sub-system
5243 sspi - SPI utility commands
5244 base - print or set address offset
5245 printenv- print environment variables
5246 setenv - set environment variables
5247 saveenv - save environment variables to persistent storage
5248 protect - enable or disable FLASH write protection
5249 erase - erase FLASH memory
5250 flinfo - print FLASH memory information
5251 nand - NAND memory operations (see doc/README.nand)
5252 bdinfo - print Board Info structure
5253 iminfo - print header information for application image
5254 coninfo - print console devices and informations
5255 ide - IDE sub-system
5256 loop - infinite loop on address range
5257 loopw - infinite write loop on address range
5258 mtest - simple RAM test
5259 icache - enable or disable instruction cache
5260 dcache - enable or disable data cache
5261 reset - Perform RESET of the CPU
5262 echo - echo args to console
5263 version - print monitor version
5264 help - print online help
5265 ? - alias for 'help'
5268 Monitor Commands - Detailed Description:
5269 ========================================
5273 For now: just type "help <command>".
5276 Environment Variables:
5277 ======================
5279 U-Boot supports user configuration using Environment Variables which
5280 can be made persistent by saving to Flash memory.
5282 Environment Variables are set using "setenv", printed using
5283 "printenv", and saved to Flash using "saveenv". Using "setenv"
5284 without a value can be used to delete a variable from the
5285 environment. As long as you don't save the environment you are
5286 working with an in-memory copy. In case the Flash area containing the
5287 environment is erased by accident, a default environment is provided.
5289 Some configuration options can be set using Environment Variables.
5291 List of environment variables (most likely not complete):
5293 baudrate - see CONFIG_BAUDRATE
5295 bootdelay - see CONFIG_BOOTDELAY
5297 bootcmd - see CONFIG_BOOTCOMMAND
5299 bootargs - Boot arguments when booting an RTOS image
5301 bootfile - Name of the image to load with TFTP
5303 bootm_low - Memory range available for image processing in the bootm
5304 command can be restricted. This variable is given as
5305 a hexadecimal number and defines lowest address allowed
5306 for use by the bootm command. See also "bootm_size"
5307 environment variable. Address defined by "bootm_low" is
5308 also the base of the initial memory mapping for the Linux
5309 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5312 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5313 This variable is given as a hexadecimal number and it
5314 defines the size of the memory region starting at base
5315 address bootm_low that is accessible by the Linux kernel
5316 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5317 as the default value if it is defined, and bootm_size is
5320 bootm_size - Memory range available for image processing in the bootm
5321 command can be restricted. This variable is given as
5322 a hexadecimal number and defines the size of the region
5323 allowed for use by the bootm command. See also "bootm_low"
5324 environment variable.
5326 updatefile - Location of the software update file on a TFTP server, used
5327 by the automatic software update feature. Please refer to
5328 documentation in doc/README.update for more details.
5330 autoload - if set to "no" (any string beginning with 'n'),
5331 "bootp" will just load perform a lookup of the
5332 configuration from the BOOTP server, but not try to
5333 load any image using TFTP
5335 autostart - if set to "yes", an image loaded using the "bootp",
5336 "rarpboot", "tftpboot" or "diskboot" commands will
5337 be automatically started (by internally calling
5340 If set to "no", a standalone image passed to the
5341 "bootm" command will be copied to the load address
5342 (and eventually uncompressed), but NOT be started.
5343 This can be used to load and uncompress arbitrary
5346 fdt_high - if set this restricts the maximum address that the
5347 flattened device tree will be copied into upon boot.
5348 For example, if you have a system with 1 GB memory
5349 at physical address 0x10000000, while Linux kernel
5350 only recognizes the first 704 MB as low memory, you
5351 may need to set fdt_high as 0x3C000000 to have the
5352 device tree blob be copied to the maximum address
5353 of the 704 MB low memory, so that Linux kernel can
5354 access it during the boot procedure.
5356 If this is set to the special value 0xFFFFFFFF then
5357 the fdt will not be copied at all on boot. For this
5358 to work it must reside in writable memory, have
5359 sufficient padding on the end of it for u-boot to
5360 add the information it needs into it, and the memory
5361 must be accessible by the kernel.
5363 fdtcontroladdr- if set this is the address of the control flattened
5364 device tree used by U-Boot when CONFIG_OF_CONTROL is
5367 i2cfast - (PPC405GP|PPC405EP only)
5368 if set to 'y' configures Linux I2C driver for fast
5369 mode (400kHZ). This environment variable is used in
5370 initialization code. So, for changes to be effective
5371 it must be saved and board must be reset.
5373 initrd_high - restrict positioning of initrd images:
5374 If this variable is not set, initrd images will be
5375 copied to the highest possible address in RAM; this
5376 is usually what you want since it allows for
5377 maximum initrd size. If for some reason you want to
5378 make sure that the initrd image is loaded below the
5379 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5380 variable to a value of "no" or "off" or "0".
5381 Alternatively, you can set it to a maximum upper
5382 address to use (U-Boot will still check that it
5383 does not overwrite the U-Boot stack and data).
5385 For instance, when you have a system with 16 MB
5386 RAM, and want to reserve 4 MB from use by Linux,
5387 you can do this by adding "mem=12M" to the value of
5388 the "bootargs" variable. However, now you must make
5389 sure that the initrd image is placed in the first
5390 12 MB as well - this can be done with
5392 setenv initrd_high 00c00000
5394 If you set initrd_high to 0xFFFFFFFF, this is an
5395 indication to U-Boot that all addresses are legal
5396 for the Linux kernel, including addresses in flash
5397 memory. In this case U-Boot will NOT COPY the
5398 ramdisk at all. This may be useful to reduce the
5399 boot time on your system, but requires that this
5400 feature is supported by your Linux kernel.
5402 ipaddr - IP address; needed for tftpboot command
5404 loadaddr - Default load address for commands like "bootp",
5405 "rarpboot", "tftpboot", "loadb" or "diskboot"
5407 loads_echo - see CONFIG_LOADS_ECHO
5409 serverip - TFTP server IP address; needed for tftpboot command
5411 bootretry - see CONFIG_BOOT_RETRY_TIME
5413 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5415 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5417 ethprime - controls which interface is used first.
5419 ethact - controls which interface is currently active.
5420 For example you can do the following
5422 => setenv ethact FEC
5423 => ping 192.168.0.1 # traffic sent on FEC
5424 => setenv ethact SCC
5425 => ping 10.0.0.1 # traffic sent on SCC
5427 ethrotate - When set to "no" U-Boot does not go through all
5428 available network interfaces.
5429 It just stays at the currently selected interface.
5431 netretry - When set to "no" each network operation will
5432 either succeed or fail without retrying.
5433 When set to "once" the network operation will
5434 fail when all the available network interfaces
5435 are tried once without success.
5436 Useful on scripts which control the retry operation
5439 npe_ucode - set load address for the NPE microcode
5441 silent_linux - If set then linux will be told to boot silently, by
5442 changing the console to be empty. If "yes" it will be
5443 made silent. If "no" it will not be made silent. If
5444 unset, then it will be made silent if the U-Boot console
5447 tftpsrcport - If this is set, the value is used for TFTP's
5450 tftpdstport - If this is set, the value is used for TFTP's UDP
5451 destination port instead of the Well Know Port 69.
5453 tftpblocksize - Block size to use for TFTP transfers; if not set,
5454 we use the TFTP server's default block size
5456 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5457 seconds, minimum value is 1000 = 1 second). Defines
5458 when a packet is considered to be lost so it has to
5459 be retransmitted. The default is 5000 = 5 seconds.
5460 Lowering this value may make downloads succeed
5461 faster in networks with high packet loss rates or
5462 with unreliable TFTP servers.
5464 vlan - When set to a value < 4095 the traffic over
5465 Ethernet is encapsulated/received over 802.1q
5468 The following image location variables contain the location of images
5469 used in booting. The "Image" column gives the role of the image and is
5470 not an environment variable name. The other columns are environment
5471 variable names. "File Name" gives the name of the file on a TFTP
5472 server, "RAM Address" gives the location in RAM the image will be
5473 loaded to, and "Flash Location" gives the image's address in NOR
5474 flash or offset in NAND flash.
5476 *Note* - these variables don't have to be defined for all boards, some
5477 boards currenlty use other variables for these purposes, and some
5478 boards use these variables for other purposes.
5480 Image File Name RAM Address Flash Location
5481 ----- --------- ----------- --------------
5482 u-boot u-boot u-boot_addr_r u-boot_addr
5483 Linux kernel bootfile kernel_addr_r kernel_addr
5484 device tree blob fdtfile fdt_addr_r fdt_addr
5485 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5487 The following environment variables may be used and automatically
5488 updated by the network boot commands ("bootp" and "rarpboot"),
5489 depending the information provided by your boot server:
5491 bootfile - see above
5492 dnsip - IP address of your Domain Name Server
5493 dnsip2 - IP address of your secondary Domain Name Server
5494 gatewayip - IP address of the Gateway (Router) to use
5495 hostname - Target hostname
5497 netmask - Subnet Mask
5498 rootpath - Pathname of the root filesystem on the NFS server
5499 serverip - see above
5502 There are two special Environment Variables:
5504 serial# - contains hardware identification information such
5505 as type string and/or serial number
5506 ethaddr - Ethernet address
5508 These variables can be set only once (usually during manufacturing of
5509 the board). U-Boot refuses to delete or overwrite these variables
5510 once they have been set once.
5513 Further special Environment Variables:
5515 ver - Contains the U-Boot version string as printed
5516 with the "version" command. This variable is
5517 readonly (see CONFIG_VERSION_VARIABLE).
5520 Please note that changes to some configuration parameters may take
5521 only effect after the next boot (yes, that's just like Windoze :-).
5524 Callback functions for environment variables:
5525 ---------------------------------------------
5527 For some environment variables, the behavior of u-boot needs to change
5528 when their values are changed. This functionailty allows functions to
5529 be associated with arbitrary variables. On creation, overwrite, or
5530 deletion, the callback will provide the opportunity for some side
5531 effect to happen or for the change to be rejected.
5533 The callbacks are named and associated with a function using the
5534 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5536 These callbacks are associated with variables in one of two ways. The
5537 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5538 in the board configuration to a string that defines a list of
5539 associations. The list must be in the following format:
5541 entry = variable_name[:callback_name]
5544 If the callback name is not specified, then the callback is deleted.
5545 Spaces are also allowed anywhere in the list.
5547 Callbacks can also be associated by defining the ".callbacks" variable
5548 with the same list format above. Any association in ".callbacks" will
5549 override any association in the static list. You can define
5550 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5551 ".callbacks" envirnoment variable in the default or embedded environment.
5554 Command Line Parsing:
5555 =====================
5557 There are two different command line parsers available with U-Boot:
5558 the old "simple" one, and the much more powerful "hush" shell:
5560 Old, simple command line parser:
5561 --------------------------------
5563 - supports environment variables (through setenv / saveenv commands)
5564 - several commands on one line, separated by ';'
5565 - variable substitution using "... ${name} ..." syntax
5566 - special characters ('$', ';') can be escaped by prefixing with '\',
5568 setenv bootcmd bootm \${address}
5569 - You can also escape text by enclosing in single apostrophes, for example:
5570 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5575 - similar to Bourne shell, with control structures like
5576 if...then...else...fi, for...do...done; while...do...done,
5577 until...do...done, ...
5578 - supports environment ("global") variables (through setenv / saveenv
5579 commands) and local shell variables (through standard shell syntax
5580 "name=value"); only environment variables can be used with "run"
5586 (1) If a command line (or an environment variable executed by a "run"
5587 command) contains several commands separated by semicolon, and
5588 one of these commands fails, then the remaining commands will be
5591 (2) If you execute several variables with one call to run (i. e.
5592 calling run with a list of variables as arguments), any failing
5593 command will cause "run" to terminate, i. e. the remaining
5594 variables are not executed.
5596 Note for Redundant Ethernet Interfaces:
5597 =======================================
5599 Some boards come with redundant Ethernet interfaces; U-Boot supports
5600 such configurations and is capable of automatic selection of a
5601 "working" interface when needed. MAC assignment works as follows:
5603 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5604 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5605 "eth1addr" (=>eth1), "eth2addr", ...
5607 If the network interface stores some valid MAC address (for instance
5608 in SROM), this is used as default address if there is NO correspon-
5609 ding setting in the environment; if the corresponding environment
5610 variable is set, this overrides the settings in the card; that means:
5612 o If the SROM has a valid MAC address, and there is no address in the
5613 environment, the SROM's address is used.
5615 o If there is no valid address in the SROM, and a definition in the
5616 environment exists, then the value from the environment variable is
5619 o If both the SROM and the environment contain a MAC address, and
5620 both addresses are the same, this MAC address is used.
5622 o If both the SROM and the environment contain a MAC address, and the
5623 addresses differ, the value from the environment is used and a
5626 o If neither SROM nor the environment contain a MAC address, an error
5629 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5630 will be programmed into hardware as part of the initialization process. This
5631 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5632 The naming convention is as follows:
5633 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5638 U-Boot is capable of booting (and performing other auxiliary operations on)
5639 images in two formats:
5641 New uImage format (FIT)
5642 -----------------------
5644 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5645 to Flattened Device Tree). It allows the use of images with multiple
5646 components (several kernels, ramdisks, etc.), with contents protected by
5647 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5653 Old image format is based on binary files which can be basically anything,
5654 preceded by a special header; see the definitions in include/image.h for
5655 details; basically, the header defines the following image properties:
5657 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5658 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5659 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5660 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5662 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5663 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5664 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5665 * Compression Type (uncompressed, gzip, bzip2)
5671 The header is marked by a special Magic Number, and both the header
5672 and the data portions of the image are secured against corruption by
5679 Although U-Boot should support any OS or standalone application
5680 easily, the main focus has always been on Linux during the design of
5683 U-Boot includes many features that so far have been part of some
5684 special "boot loader" code within the Linux kernel. Also, any
5685 "initrd" images to be used are no longer part of one big Linux image;
5686 instead, kernel and "initrd" are separate images. This implementation
5687 serves several purposes:
5689 - the same features can be used for other OS or standalone
5690 applications (for instance: using compressed images to reduce the
5691 Flash memory footprint)
5693 - it becomes much easier to port new Linux kernel versions because
5694 lots of low-level, hardware dependent stuff are done by U-Boot
5696 - the same Linux kernel image can now be used with different "initrd"
5697 images; of course this also means that different kernel images can
5698 be run with the same "initrd". This makes testing easier (you don't
5699 have to build a new "zImage.initrd" Linux image when you just
5700 change a file in your "initrd"). Also, a field-upgrade of the
5701 software is easier now.
5707 Porting Linux to U-Boot based systems:
5708 ---------------------------------------
5710 U-Boot cannot save you from doing all the necessary modifications to
5711 configure the Linux device drivers for use with your target hardware
5712 (no, we don't intend to provide a full virtual machine interface to
5715 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5717 Just make sure your machine specific header file (for instance
5718 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5719 Information structure as we define in include/asm-<arch>/u-boot.h,
5720 and make sure that your definition of IMAP_ADDR uses the same value
5721 as your U-Boot configuration in CONFIG_SYS_IMMR.
5723 Note that U-Boot now has a driver model, a unified model for drivers.
5724 If you are adding a new driver, plumb it into driver model. If there
5725 is no uclass available, you are encouraged to create one. See
5729 Configuring the Linux kernel:
5730 -----------------------------
5732 No specific requirements for U-Boot. Make sure you have some root
5733 device (initial ramdisk, NFS) for your target system.
5736 Building a Linux Image:
5737 -----------------------
5739 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5740 not used. If you use recent kernel source, a new build target
5741 "uImage" will exist which automatically builds an image usable by
5742 U-Boot. Most older kernels also have support for a "pImage" target,
5743 which was introduced for our predecessor project PPCBoot and uses a
5744 100% compatible format.
5748 make TQM850L_defconfig
5753 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5754 encapsulate a compressed Linux kernel image with header information,
5755 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5757 * build a standard "vmlinux" kernel image (in ELF binary format):
5759 * convert the kernel into a raw binary image:
5761 ${CROSS_COMPILE}-objcopy -O binary \
5762 -R .note -R .comment \
5763 -S vmlinux linux.bin
5765 * compress the binary image:
5769 * package compressed binary image for U-Boot:
5771 mkimage -A ppc -O linux -T kernel -C gzip \
5772 -a 0 -e 0 -n "Linux Kernel Image" \
5773 -d linux.bin.gz uImage
5776 The "mkimage" tool can also be used to create ramdisk images for use
5777 with U-Boot, either separated from the Linux kernel image, or
5778 combined into one file. "mkimage" encapsulates the images with a 64
5779 byte header containing information about target architecture,
5780 operating system, image type, compression method, entry points, time
5781 stamp, CRC32 checksums, etc.
5783 "mkimage" can be called in two ways: to verify existing images and
5784 print the header information, or to build new images.
5786 In the first form (with "-l" option) mkimage lists the information
5787 contained in the header of an existing U-Boot image; this includes
5788 checksum verification:
5790 tools/mkimage -l image
5791 -l ==> list image header information
5793 The second form (with "-d" option) is used to build a U-Boot image
5794 from a "data file" which is used as image payload:
5796 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5797 -n name -d data_file image
5798 -A ==> set architecture to 'arch'
5799 -O ==> set operating system to 'os'
5800 -T ==> set image type to 'type'
5801 -C ==> set compression type 'comp'
5802 -a ==> set load address to 'addr' (hex)
5803 -e ==> set entry point to 'ep' (hex)
5804 -n ==> set image name to 'name'
5805 -d ==> use image data from 'datafile'
5807 Right now, all Linux kernels for PowerPC systems use the same load
5808 address (0x00000000), but the entry point address depends on the
5811 - 2.2.x kernels have the entry point at 0x0000000C,
5812 - 2.3.x and later kernels have the entry point at 0x00000000.
5814 So a typical call to build a U-Boot image would read:
5816 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5817 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5818 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5819 > examples/uImage.TQM850L
5820 Image Name: 2.4.4 kernel for TQM850L
5821 Created: Wed Jul 19 02:34:59 2000
5822 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5823 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5824 Load Address: 0x00000000
5825 Entry Point: 0x00000000
5827 To verify the contents of the image (or check for corruption):
5829 -> tools/mkimage -l examples/uImage.TQM850L
5830 Image Name: 2.4.4 kernel for TQM850L
5831 Created: Wed Jul 19 02:34:59 2000
5832 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5833 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5834 Load Address: 0x00000000
5835 Entry Point: 0x00000000
5837 NOTE: for embedded systems where boot time is critical you can trade
5838 speed for memory and install an UNCOMPRESSED image instead: this
5839 needs more space in Flash, but boots much faster since it does not
5840 need to be uncompressed:
5842 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5843 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5844 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5845 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5846 > examples/uImage.TQM850L-uncompressed
5847 Image Name: 2.4.4 kernel for TQM850L
5848 Created: Wed Jul 19 02:34:59 2000
5849 Image Type: PowerPC Linux Kernel Image (uncompressed)
5850 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5851 Load Address: 0x00000000
5852 Entry Point: 0x00000000
5855 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5856 when your kernel is intended to use an initial ramdisk:
5858 -> tools/mkimage -n 'Simple Ramdisk Image' \
5859 > -A ppc -O linux -T ramdisk -C gzip \
5860 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5861 Image Name: Simple Ramdisk Image
5862 Created: Wed Jan 12 14:01:50 2000
5863 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5864 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5865 Load Address: 0x00000000
5866 Entry Point: 0x00000000
5868 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5869 option performs the converse operation of the mkimage's second form (the "-d"
5870 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5873 tools/dumpimage -i image -p position data_file
5874 -i ==> extract from the 'image' a specific 'data_file', \
5875 indexed by 'position'
5878 Installing a Linux Image:
5879 -------------------------
5881 To downloading a U-Boot image over the serial (console) interface,
5882 you must convert the image to S-Record format:
5884 objcopy -I binary -O srec examples/image examples/image.srec
5886 The 'objcopy' does not understand the information in the U-Boot
5887 image header, so the resulting S-Record file will be relative to
5888 address 0x00000000. To load it to a given address, you need to
5889 specify the target address as 'offset' parameter with the 'loads'
5892 Example: install the image to address 0x40100000 (which on the
5893 TQM8xxL is in the first Flash bank):
5895 => erase 40100000 401FFFFF
5901 ## Ready for S-Record download ...
5902 ~>examples/image.srec
5903 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5905 15989 15990 15991 15992
5906 [file transfer complete]
5908 ## Start Addr = 0x00000000
5911 You can check the success of the download using the 'iminfo' command;
5912 this includes a checksum verification so you can be sure no data
5913 corruption happened:
5917 ## Checking Image at 40100000 ...
5918 Image Name: 2.2.13 for initrd on TQM850L
5919 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5920 Data Size: 335725 Bytes = 327 kB = 0 MB
5921 Load Address: 00000000
5922 Entry Point: 0000000c
5923 Verifying Checksum ... OK
5929 The "bootm" command is used to boot an application that is stored in
5930 memory (RAM or Flash). In case of a Linux kernel image, the contents
5931 of the "bootargs" environment variable is passed to the kernel as
5932 parameters. You can check and modify this variable using the
5933 "printenv" and "setenv" commands:
5936 => printenv bootargs
5937 bootargs=root=/dev/ram
5939 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5941 => printenv bootargs
5942 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5945 ## Booting Linux kernel at 40020000 ...
5946 Image Name: 2.2.13 for NFS on TQM850L
5947 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5948 Data Size: 381681 Bytes = 372 kB = 0 MB
5949 Load Address: 00000000
5950 Entry Point: 0000000c
5951 Verifying Checksum ... OK
5952 Uncompressing Kernel Image ... OK
5953 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
5954 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5955 time_init: decrementer frequency = 187500000/60
5956 Calibrating delay loop... 49.77 BogoMIPS
5957 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5960 If you want to boot a Linux kernel with initial RAM disk, you pass
5961 the memory addresses of both the kernel and the initrd image (PPBCOOT
5962 format!) to the "bootm" command:
5964 => imi 40100000 40200000
5966 ## Checking Image at 40100000 ...
5967 Image Name: 2.2.13 for initrd on TQM850L
5968 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5969 Data Size: 335725 Bytes = 327 kB = 0 MB
5970 Load Address: 00000000
5971 Entry Point: 0000000c
5972 Verifying Checksum ... OK
5974 ## Checking Image at 40200000 ...
5975 Image Name: Simple Ramdisk Image
5976 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5977 Data Size: 566530 Bytes = 553 kB = 0 MB
5978 Load Address: 00000000
5979 Entry Point: 00000000
5980 Verifying Checksum ... OK
5982 => bootm 40100000 40200000
5983 ## Booting Linux kernel at 40100000 ...
5984 Image Name: 2.2.13 for initrd on TQM850L
5985 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5986 Data Size: 335725 Bytes = 327 kB = 0 MB
5987 Load Address: 00000000
5988 Entry Point: 0000000c
5989 Verifying Checksum ... OK
5990 Uncompressing Kernel Image ... OK
5991 ## Loading RAMDisk Image at 40200000 ...
5992 Image Name: Simple Ramdisk Image
5993 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5994 Data Size: 566530 Bytes = 553 kB = 0 MB
5995 Load Address: 00000000
5996 Entry Point: 00000000
5997 Verifying Checksum ... OK
5998 Loading Ramdisk ... OK
5999 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
6000 Boot arguments: root=/dev/ram
6001 time_init: decrementer frequency = 187500000/60
6002 Calibrating delay loop... 49.77 BogoMIPS
6004 RAMDISK: Compressed image found at block 0
6005 VFS: Mounted root (ext2 filesystem).
6009 Boot Linux and pass a flat device tree:
6012 First, U-Boot must be compiled with the appropriate defines. See the section
6013 titled "Linux Kernel Interface" above for a more in depth explanation. The
6014 following is an example of how to start a kernel and pass an updated
6020 oft=oftrees/mpc8540ads.dtb
6021 => tftp $oftaddr $oft
6022 Speed: 1000, full duplex
6024 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6025 Filename 'oftrees/mpc8540ads.dtb'.
6026 Load address: 0x300000
6029 Bytes transferred = 4106 (100a hex)
6030 => tftp $loadaddr $bootfile
6031 Speed: 1000, full duplex
6033 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6035 Load address: 0x200000
6036 Loading:############
6038 Bytes transferred = 1029407 (fb51f hex)
6043 => bootm $loadaddr - $oftaddr
6044 ## Booting image at 00200000 ...
6045 Image Name: Linux-2.6.17-dirty
6046 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6047 Data Size: 1029343 Bytes = 1005.2 kB
6048 Load Address: 00000000
6049 Entry Point: 00000000
6050 Verifying Checksum ... OK
6051 Uncompressing Kernel Image ... OK
6052 Booting using flat device tree at 0x300000
6053 Using MPC85xx ADS machine description
6054 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6058 More About U-Boot Image Types:
6059 ------------------------------
6061 U-Boot supports the following image types:
6063 "Standalone Programs" are directly runnable in the environment
6064 provided by U-Boot; it is expected that (if they behave
6065 well) you can continue to work in U-Boot after return from
6066 the Standalone Program.
6067 "OS Kernel Images" are usually images of some Embedded OS which
6068 will take over control completely. Usually these programs
6069 will install their own set of exception handlers, device
6070 drivers, set up the MMU, etc. - this means, that you cannot
6071 expect to re-enter U-Boot except by resetting the CPU.
6072 "RAMDisk Images" are more or less just data blocks, and their
6073 parameters (address, size) are passed to an OS kernel that is
6075 "Multi-File Images" contain several images, typically an OS
6076 (Linux) kernel image and one or more data images like
6077 RAMDisks. This construct is useful for instance when you want
6078 to boot over the network using BOOTP etc., where the boot
6079 server provides just a single image file, but you want to get
6080 for instance an OS kernel and a RAMDisk image.
6082 "Multi-File Images" start with a list of image sizes, each
6083 image size (in bytes) specified by an "uint32_t" in network
6084 byte order. This list is terminated by an "(uint32_t)0".
6085 Immediately after the terminating 0 follow the images, one by
6086 one, all aligned on "uint32_t" boundaries (size rounded up to
6087 a multiple of 4 bytes).
6089 "Firmware Images" are binary images containing firmware (like
6090 U-Boot or FPGA images) which usually will be programmed to
6093 "Script files" are command sequences that will be executed by
6094 U-Boot's command interpreter; this feature is especially
6095 useful when you configure U-Boot to use a real shell (hush)
6096 as command interpreter.
6098 Booting the Linux zImage:
6099 -------------------------
6101 On some platforms, it's possible to boot Linux zImage. This is done
6102 using the "bootz" command. The syntax of "bootz" command is the same
6103 as the syntax of "bootm" command.
6105 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6106 kernel with raw initrd images. The syntax is slightly different, the
6107 address of the initrd must be augmented by it's size, in the following
6108 format: "<initrd addres>:<initrd size>".
6114 One of the features of U-Boot is that you can dynamically load and
6115 run "standalone" applications, which can use some resources of
6116 U-Boot like console I/O functions or interrupt services.
6118 Two simple examples are included with the sources:
6123 'examples/hello_world.c' contains a small "Hello World" Demo
6124 application; it is automatically compiled when you build U-Boot.
6125 It's configured to run at address 0x00040004, so you can play with it
6129 ## Ready for S-Record download ...
6130 ~>examples/hello_world.srec
6131 1 2 3 4 5 6 7 8 9 10 11 ...
6132 [file transfer complete]
6134 ## Start Addr = 0x00040004
6136 => go 40004 Hello World! This is a test.
6137 ## Starting application at 0x00040004 ...
6148 Hit any key to exit ...
6150 ## Application terminated, rc = 0x0
6152 Another example, which demonstrates how to register a CPM interrupt
6153 handler with the U-Boot code, can be found in 'examples/timer.c'.
6154 Here, a CPM timer is set up to generate an interrupt every second.
6155 The interrupt service routine is trivial, just printing a '.'
6156 character, but this is just a demo program. The application can be
6157 controlled by the following keys:
6159 ? - print current values og the CPM Timer registers
6160 b - enable interrupts and start timer
6161 e - stop timer and disable interrupts
6162 q - quit application
6165 ## Ready for S-Record download ...
6166 ~>examples/timer.srec
6167 1 2 3 4 5 6 7 8 9 10 11 ...
6168 [file transfer complete]
6170 ## Start Addr = 0x00040004
6173 ## Starting application at 0x00040004 ...
6176 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6179 [q, b, e, ?] Set interval 1000000 us
6182 [q, b, e, ?] ........
6183 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6186 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6189 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6192 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6194 [q, b, e, ?] ...Stopping timer
6196 [q, b, e, ?] ## Application terminated, rc = 0x0
6202 Over time, many people have reported problems when trying to use the
6203 "minicom" terminal emulation program for serial download. I (wd)
6204 consider minicom to be broken, and recommend not to use it. Under
6205 Unix, I recommend to use C-Kermit for general purpose use (and
6206 especially for kermit binary protocol download ("loadb" command), and
6207 use "cu" for S-Record download ("loads" command). See
6208 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6209 for help with kermit.
6212 Nevertheless, if you absolutely want to use it try adding this
6213 configuration to your "File transfer protocols" section:
6215 Name Program Name U/D FullScr IO-Red. Multi
6216 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6217 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6223 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6224 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6226 Building requires a cross environment; it is known to work on
6227 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6228 need gmake since the Makefiles are not compatible with BSD make).
6229 Note that the cross-powerpc package does not install include files;
6230 attempting to build U-Boot will fail because <machine/ansi.h> is
6231 missing. This file has to be installed and patched manually:
6233 # cd /usr/pkg/cross/powerpc-netbsd/include
6235 # ln -s powerpc machine
6236 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6237 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6239 Native builds *don't* work due to incompatibilities between native
6240 and U-Boot include files.
6242 Booting assumes that (the first part of) the image booted is a
6243 stage-2 loader which in turn loads and then invokes the kernel
6244 proper. Loader sources will eventually appear in the NetBSD source
6245 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6246 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6249 Implementation Internals:
6250 =========================
6252 The following is not intended to be a complete description of every
6253 implementation detail. However, it should help to understand the
6254 inner workings of U-Boot and make it easier to port it to custom
6258 Initial Stack, Global Data:
6259 ---------------------------
6261 The implementation of U-Boot is complicated by the fact that U-Boot
6262 starts running out of ROM (flash memory), usually without access to
6263 system RAM (because the memory controller is not initialized yet).
6264 This means that we don't have writable Data or BSS segments, and BSS
6265 is not initialized as zero. To be able to get a C environment working
6266 at all, we have to allocate at least a minimal stack. Implementation
6267 options for this are defined and restricted by the CPU used: Some CPU
6268 models provide on-chip memory (like the IMMR area on MPC8xx and
6269 MPC826x processors), on others (parts of) the data cache can be
6270 locked as (mis-) used as memory, etc.
6272 Chris Hallinan posted a good summary of these issues to the
6273 U-Boot mailing list:
6275 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6276 From: "Chris Hallinan" <clh@net1plus.com>
6277 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6280 Correct me if I'm wrong, folks, but the way I understand it
6281 is this: Using DCACHE as initial RAM for Stack, etc, does not
6282 require any physical RAM backing up the cache. The cleverness
6283 is that the cache is being used as a temporary supply of
6284 necessary storage before the SDRAM controller is setup. It's
6285 beyond the scope of this list to explain the details, but you
6286 can see how this works by studying the cache architecture and
6287 operation in the architecture and processor-specific manuals.
6289 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6290 is another option for the system designer to use as an
6291 initial stack/RAM area prior to SDRAM being available. Either
6292 option should work for you. Using CS 4 should be fine if your
6293 board designers haven't used it for something that would
6294 cause you grief during the initial boot! It is frequently not
6297 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6298 with your processor/board/system design. The default value
6299 you will find in any recent u-boot distribution in
6300 walnut.h should work for you. I'd set it to a value larger
6301 than your SDRAM module. If you have a 64MB SDRAM module, set
6302 it above 400_0000. Just make sure your board has no resources
6303 that are supposed to respond to that address! That code in
6304 start.S has been around a while and should work as is when
6305 you get the config right.
6310 It is essential to remember this, since it has some impact on the C
6311 code for the initialization procedures:
6313 * Initialized global data (data segment) is read-only. Do not attempt
6316 * Do not use any uninitialized global data (or implicitely initialized
6317 as zero data - BSS segment) at all - this is undefined, initiali-
6318 zation is performed later (when relocating to RAM).
6320 * Stack space is very limited. Avoid big data buffers or things like
6323 Having only the stack as writable memory limits means we cannot use
6324 normal global data to share information beween the code. But it
6325 turned out that the implementation of U-Boot can be greatly
6326 simplified by making a global data structure (gd_t) available to all
6327 functions. We could pass a pointer to this data as argument to _all_
6328 functions, but this would bloat the code. Instead we use a feature of
6329 the GCC compiler (Global Register Variables) to share the data: we
6330 place a pointer (gd) to the global data into a register which we
6331 reserve for this purpose.
6333 When choosing a register for such a purpose we are restricted by the
6334 relevant (E)ABI specifications for the current architecture, and by
6335 GCC's implementation.
6337 For PowerPC, the following registers have specific use:
6339 R2: reserved for system use
6340 R3-R4: parameter passing and return values
6341 R5-R10: parameter passing
6342 R13: small data area pointer
6346 (U-Boot also uses R12 as internal GOT pointer. r12
6347 is a volatile register so r12 needs to be reset when
6348 going back and forth between asm and C)
6350 ==> U-Boot will use R2 to hold a pointer to the global data
6352 Note: on PPC, we could use a static initializer (since the
6353 address of the global data structure is known at compile time),
6354 but it turned out that reserving a register results in somewhat
6355 smaller code - although the code savings are not that big (on
6356 average for all boards 752 bytes for the whole U-Boot image,
6357 624 text + 127 data).
6359 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6360 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6362 ==> U-Boot will use P3 to hold a pointer to the global data
6364 On ARM, the following registers are used:
6366 R0: function argument word/integer result
6367 R1-R3: function argument word
6368 R9: platform specific
6369 R10: stack limit (used only if stack checking is enabled)
6370 R11: argument (frame) pointer
6371 R12: temporary workspace
6374 R15: program counter
6376 ==> U-Boot will use R9 to hold a pointer to the global data
6378 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6380 On Nios II, the ABI is documented here:
6381 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6383 ==> U-Boot will use gp to hold a pointer to the global data
6385 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6386 to access small data sections, so gp is free.
6388 On NDS32, the following registers are used:
6390 R0-R1: argument/return
6392 R15: temporary register for assembler
6393 R16: trampoline register
6394 R28: frame pointer (FP)
6395 R29: global pointer (GP)
6396 R30: link register (LP)
6397 R31: stack pointer (SP)
6398 PC: program counter (PC)
6400 ==> U-Boot will use R10 to hold a pointer to the global data
6402 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6403 or current versions of GCC may "optimize" the code too much.
6408 U-Boot runs in system state and uses physical addresses, i.e. the
6409 MMU is not used either for address mapping nor for memory protection.
6411 The available memory is mapped to fixed addresses using the memory
6412 controller. In this process, a contiguous block is formed for each
6413 memory type (Flash, SDRAM, SRAM), even when it consists of several
6414 physical memory banks.
6416 U-Boot is installed in the first 128 kB of the first Flash bank (on
6417 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6418 booting and sizing and initializing DRAM, the code relocates itself
6419 to the upper end of DRAM. Immediately below the U-Boot code some
6420 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6421 configuration setting]. Below that, a structure with global Board
6422 Info data is placed, followed by the stack (growing downward).
6424 Additionally, some exception handler code is copied to the low 8 kB
6425 of DRAM (0x00000000 ... 0x00001FFF).
6427 So a typical memory configuration with 16 MB of DRAM could look like
6430 0x0000 0000 Exception Vector code
6433 0x0000 2000 Free for Application Use
6439 0x00FB FF20 Monitor Stack (Growing downward)
6440 0x00FB FFAC Board Info Data and permanent copy of global data
6441 0x00FC 0000 Malloc Arena
6444 0x00FE 0000 RAM Copy of Monitor Code
6445 ... eventually: LCD or video framebuffer
6446 ... eventually: pRAM (Protected RAM - unchanged by reset)
6447 0x00FF FFFF [End of RAM]
6450 System Initialization:
6451 ----------------------
6453 In the reset configuration, U-Boot starts at the reset entry point
6454 (on most PowerPC systems at address 0x00000100). Because of the reset
6455 configuration for CS0# this is a mirror of the onboard Flash memory.
6456 To be able to re-map memory U-Boot then jumps to its link address.
6457 To be able to implement the initialization code in C, a (small!)
6458 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6459 which provide such a feature like MPC8xx or MPC8260), or in a locked
6460 part of the data cache. After that, U-Boot initializes the CPU core,
6461 the caches and the SIU.
6463 Next, all (potentially) available memory banks are mapped using a
6464 preliminary mapping. For example, we put them on 512 MB boundaries
6465 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6466 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6467 programmed for SDRAM access. Using the temporary configuration, a
6468 simple memory test is run that determines the size of the SDRAM
6471 When there is more than one SDRAM bank, and the banks are of
6472 different size, the largest is mapped first. For equal size, the first
6473 bank (CS2#) is mapped first. The first mapping is always for address
6474 0x00000000, with any additional banks following immediately to create
6475 contiguous memory starting from 0.
6477 Then, the monitor installs itself at the upper end of the SDRAM area
6478 and allocates memory for use by malloc() and for the global Board
6479 Info data; also, the exception vector code is copied to the low RAM
6480 pages, and the final stack is set up.
6482 Only after this relocation will you have a "normal" C environment;
6483 until that you are restricted in several ways, mostly because you are
6484 running from ROM, and because the code will have to be relocated to a
6488 U-Boot Porting Guide:
6489 ----------------------
6491 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6495 int main(int argc, char *argv[])
6497 sighandler_t no_more_time;
6499 signal(SIGALRM, no_more_time);
6500 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6502 if (available_money > available_manpower) {
6503 Pay consultant to port U-Boot;
6507 Download latest U-Boot source;
6509 Subscribe to u-boot mailing list;
6512 email("Hi, I am new to U-Boot, how do I get started?");
6515 Read the README file in the top level directory;
6516 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6517 Read applicable doc/*.README;
6518 Read the source, Luke;
6519 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6522 if (available_money > toLocalCurrency ($2500))
6525 Add a lot of aggravation and time;
6527 if (a similar board exists) { /* hopefully... */
6528 cp -a board/<similar> board/<myboard>
6529 cp include/configs/<similar>.h include/configs/<myboard>.h
6531 Create your own board support subdirectory;
6532 Create your own board include/configs/<myboard>.h file;
6534 Edit new board/<myboard> files
6535 Edit new include/configs/<myboard>.h
6540 Add / modify source code;
6544 email("Hi, I am having problems...");
6546 Send patch file to the U-Boot email list;
6547 if (reasonable critiques)
6548 Incorporate improvements from email list code review;
6550 Defend code as written;
6556 void no_more_time (int sig)
6565 All contributions to U-Boot should conform to the Linux kernel
6566 coding style; see the file "Documentation/CodingStyle" and the script
6567 "scripts/Lindent" in your Linux kernel source directory.
6569 Source files originating from a different project (for example the
6570 MTD subsystem) are generally exempt from these guidelines and are not
6571 reformated to ease subsequent migration to newer versions of those
6574 Please note that U-Boot is implemented in C (and to some small parts in
6575 Assembler); no C++ is used, so please do not use C++ style comments (//)
6578 Please also stick to the following formatting rules:
6579 - remove any trailing white space
6580 - use TAB characters for indentation and vertical alignment, not spaces
6581 - make sure NOT to use DOS '\r\n' line feeds
6582 - do not add more than 2 consecutive empty lines to source files
6583 - do not add trailing empty lines to source files
6585 Submissions which do not conform to the standards may be returned
6586 with a request to reformat the changes.
6592 Since the number of patches for U-Boot is growing, we need to
6593 establish some rules. Submissions which do not conform to these rules
6594 may be rejected, even when they contain important and valuable stuff.
6596 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6598 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6599 see http://lists.denx.de/mailman/listinfo/u-boot
6601 When you send a patch, please include the following information with
6604 * For bug fixes: a description of the bug and how your patch fixes
6605 this bug. Please try to include a way of demonstrating that the
6606 patch actually fixes something.
6608 * For new features: a description of the feature and your
6611 * A CHANGELOG entry as plaintext (separate from the patch)
6613 * For major contributions, your entry to the CREDITS file
6615 * When you add support for a new board, don't forget to add a
6616 maintainer e-mail address to the boards.cfg file, too.
6618 * If your patch adds new configuration options, don't forget to
6619 document these in the README file.
6621 * The patch itself. If you are using git (which is *strongly*
6622 recommended) you can easily generate the patch using the
6623 "git format-patch". If you then use "git send-email" to send it to
6624 the U-Boot mailing list, you will avoid most of the common problems
6625 with some other mail clients.
6627 If you cannot use git, use "diff -purN OLD NEW". If your version of
6628 diff does not support these options, then get the latest version of
6631 The current directory when running this command shall be the parent
6632 directory of the U-Boot source tree (i. e. please make sure that
6633 your patch includes sufficient directory information for the
6636 We prefer patches as plain text. MIME attachments are discouraged,
6637 and compressed attachments must not be used.
6639 * If one logical set of modifications affects or creates several
6640 files, all these changes shall be submitted in a SINGLE patch file.
6642 * Changesets that contain different, unrelated modifications shall be
6643 submitted as SEPARATE patches, one patch per changeset.
6648 * Before sending the patch, run the MAKEALL script on your patched
6649 source tree and make sure that no errors or warnings are reported
6650 for any of the boards.
6652 * Keep your modifications to the necessary minimum: A patch
6653 containing several unrelated changes or arbitrary reformats will be
6654 returned with a request to re-formatting / split it.
6656 * If you modify existing code, make sure that your new code does not
6657 add to the memory footprint of the code ;-) Small is beautiful!
6658 When adding new features, these should compile conditionally only
6659 (using #ifdef), and the resulting code with the new feature
6660 disabled must not need more memory than the old code without your
6663 * Remember that there is a size limit of 100 kB per message on the
6664 u-boot mailing list. Bigger patches will be moderated. If they are
6665 reasonable and not too big, they will be acknowledged. But patches
6666 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob