2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc8260 Files specific to Freescale MPC8260 CPUs
190 /mpc85xx Files specific to Freescale MPC85xx CPUs
191 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
192 /lib Architecture specific library files
193 /sh Files generic to SH architecture
194 /cpu CPU specific files
195 /sh2 Files specific to sh2 CPUs
196 /sh3 Files specific to sh3 CPUs
197 /sh4 Files specific to sh4 CPUs
198 /lib Architecture specific library files
199 /sparc Files generic to SPARC architecture
200 /cpu CPU specific files
201 /leon2 Files specific to Gaisler LEON2 SPARC CPU
202 /leon3 Files specific to Gaisler LEON3 SPARC CPU
203 /lib Architecture specific library files
204 /x86 Files generic to x86 architecture
205 /cpu CPU specific files
206 /lib Architecture specific library files
207 /api Machine/arch independent API for external apps
208 /board Board dependent files
209 /common Misc architecture independent functions
210 /disk Code for disk drive partition handling
211 /doc Documentation (don't expect too much)
212 /drivers Commonly used device drivers
213 /dts Contains Makefile for building internal U-Boot fdt.
214 /examples Example code for standalone applications, etc.
215 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
216 /include Header Files
217 /lib Files generic to all architectures
218 /libfdt Library files to support flattened device trees
219 /lzma Library files to support LZMA decompression
220 /lzo Library files to support LZO decompression
222 /post Power On Self Test
223 /spl Secondary Program Loader framework
224 /tools Tools to build S-Record or U-Boot images, etc.
226 Software Configuration:
227 =======================
229 Configuration is usually done using C preprocessor defines; the
230 rationale behind that is to avoid dead code whenever possible.
232 There are two classes of configuration variables:
234 * Configuration _OPTIONS_:
235 These are selectable by the user and have names beginning with
238 * Configuration _SETTINGS_:
239 These depend on the hardware etc. and should not be meddled with if
240 you don't know what you're doing; they have names beginning with
243 Later we will add a configuration tool - probably similar to or even
244 identical to what's used for the Linux kernel. Right now, we have to
245 do the configuration by hand, which means creating some symbolic
246 links and editing some configuration files. We use the TQM8xxL boards
250 Selection of Processor Architecture and Board Type:
251 ---------------------------------------------------
253 For all supported boards there are ready-to-use default
254 configurations available; just type "make <board_name>_defconfig".
256 Example: For a TQM823L module type:
259 make TQM823L_defconfig
261 For the Cogent platform, you need to specify the CPU type as well;
262 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
263 directory according to the instructions in cogent/README.
269 U-Boot can be built natively to run on a Linux host using the 'sandbox'
270 board. This allows feature development which is not board- or architecture-
271 specific to be undertaken on a native platform. The sandbox is also used to
272 run some of U-Boot's tests.
274 See board/sandbox/README.sandbox for more details.
277 Configuration Options:
278 ----------------------
280 Configuration depends on the combination of board and CPU type; all
281 such information is kept in a configuration file
282 "include/configs/<board_name>.h".
284 Example: For a TQM823L module, all configuration settings are in
285 "include/configs/TQM823L.h".
288 Many of the options are named exactly as the corresponding Linux
289 kernel configuration options. The intention is to make it easier to
290 build a config tool - later.
293 The following options need to be configured:
295 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
297 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
299 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
300 Define exactly one, e.g. CONFIG_ATSTK1002
302 - CPU Module Type: (if CONFIG_COGENT is defined)
303 Define exactly one of
305 --- FIXME --- not tested yet:
306 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
307 CONFIG_CMA287_23, CONFIG_CMA287_50
309 - Motherboard Type: (if CONFIG_COGENT is defined)
310 Define exactly one of
311 CONFIG_CMA101, CONFIG_CMA102
313 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
314 Define one or more of
317 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
318 Define one or more of
319 CONFIG_LCD_HEARTBEAT - update a character position on
320 the LCD display every second with
323 - Marvell Family Member
324 CONFIG_SYS_MVFS - define it if you want to enable
325 multiple fs option at one time
326 for marvell soc family
328 - 8xx CPU Options: (if using an MPC8xx CPU)
329 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
330 get_gclk_freq() cannot work
331 e.g. if there is no 32KHz
332 reference PIT/RTC clock
333 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
336 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
337 CONFIG_SYS_8xx_CPUCLK_MIN
338 CONFIG_SYS_8xx_CPUCLK_MAX
339 CONFIG_8xx_CPUCLK_DEFAULT
340 See doc/README.MPC866
342 CONFIG_SYS_MEASURE_CPUCLK
344 Define this to measure the actual CPU clock instead
345 of relying on the correctness of the configured
346 values. Mostly useful for board bringup to make sure
347 the PLL is locked at the intended frequency. Note
348 that this requires a (stable) reference clock (32 kHz
349 RTC clock or CONFIG_SYS_8XX_XIN)
351 CONFIG_SYS_DELAYED_ICACHE
353 Define this option if you want to enable the
354 ICache only when Code runs from RAM.
359 Specifies that the core is a 64-bit PowerPC implementation (implements
360 the "64" category of the Power ISA). This is necessary for ePAPR
361 compliance, among other possible reasons.
363 CONFIG_SYS_FSL_TBCLK_DIV
365 Defines the core time base clock divider ratio compared to the
366 system clock. On most PQ3 devices this is 8, on newer QorIQ
367 devices it can be 16 or 32. The ratio varies from SoC to Soc.
369 CONFIG_SYS_FSL_PCIE_COMPAT
371 Defines the string to utilize when trying to match PCIe device
372 tree nodes for the given platform.
374 CONFIG_SYS_PPC_E500_DEBUG_TLB
376 Enables a temporary TLB entry to be used during boot to work
377 around limitations in e500v1 and e500v2 external debugger
378 support. This reduces the portions of the boot code where
379 breakpoints and single stepping do not work. The value of this
380 symbol should be set to the TLB1 entry to be used for this
383 CONFIG_SYS_FSL_ERRATUM_A004510
385 Enables a workaround for erratum A004510. If set,
386 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
387 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
390 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
392 Defines one or two SoC revisions (low 8 bits of SVR)
393 for which the A004510 workaround should be applied.
395 The rest of SVR is either not relevant to the decision
396 of whether the erratum is present (e.g. p2040 versus
397 p2041) or is implied by the build target, which controls
398 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
400 See Freescale App Note 4493 for more information about
403 CONFIG_A003399_NOR_WORKAROUND
404 Enables a workaround for IFC erratum A003399. It is only
405 required during NOR boot.
407 CONFIG_A008044_WORKAROUND
408 Enables a workaround for T1040/T1042 erratum A008044. It is only
409 required during NAND boot and valid for Rev 1.0 SoC revision
411 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
413 This is the value to write into CCSR offset 0x18600
414 according to the A004510 workaround.
416 CONFIG_SYS_FSL_DSP_DDR_ADDR
417 This value denotes start offset of DDR memory which is
418 connected exclusively to the DSP cores.
420 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
421 This value denotes start offset of M2 memory
422 which is directly connected to the DSP core.
424 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
425 This value denotes start offset of M3 memory which is directly
426 connected to the DSP core.
428 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
429 This value denotes start offset of DSP CCSR space.
431 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
432 Single Source Clock is clocking mode present in some of FSL SoC's.
433 In this mode, a single differential clock is used to supply
434 clocks to the sysclock, ddrclock and usbclock.
436 CONFIG_SYS_CPC_REINIT_F
437 This CONFIG is defined when the CPC is configured as SRAM at the
438 time of U-boot entry and is required to be re-initialized.
441 Indicates this SoC supports deep sleep feature. If deep sleep is
442 supported, core will start to execute uboot when wakes up.
444 - Generic CPU options:
445 CONFIG_SYS_GENERIC_GLOBAL_DATA
446 Defines global data is initialized in generic board board_init_f().
447 If this macro is defined, global data is created and cleared in
448 generic board board_init_f(). Without this macro, architecture/board
449 should initialize global data before calling board_init_f().
451 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
453 Defines the endianess of the CPU. Implementation of those
454 values is arch specific.
457 Freescale DDR driver in use. This type of DDR controller is
458 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
461 CONFIG_SYS_FSL_DDR_ADDR
462 Freescale DDR memory-mapped register base.
464 CONFIG_SYS_FSL_DDR_EMU
465 Specify emulator support for DDR. Some DDR features such as
466 deskew training are not available.
468 CONFIG_SYS_FSL_DDRC_GEN1
469 Freescale DDR1 controller.
471 CONFIG_SYS_FSL_DDRC_GEN2
472 Freescale DDR2 controller.
474 CONFIG_SYS_FSL_DDRC_GEN3
475 Freescale DDR3 controller.
477 CONFIG_SYS_FSL_DDRC_GEN4
478 Freescale DDR4 controller.
480 CONFIG_SYS_FSL_DDRC_ARM_GEN3
481 Freescale DDR3 controller for ARM-based SoCs.
484 Board config to use DDR1. It can be enabled for SoCs with
485 Freescale DDR1 or DDR2 controllers, depending on the board
489 Board config to use DDR2. It can be eanbeld for SoCs with
490 Freescale DDR2 or DDR3 controllers, depending on the board
494 Board config to use DDR3. It can be enabled for SoCs with
495 Freescale DDR3 or DDR3L controllers.
498 Board config to use DDR3L. It can be enabled for SoCs with
502 Board config to use DDR4. It can be enabled for SoCs with
505 CONFIG_SYS_FSL_IFC_BE
506 Defines the IFC controller register space as Big Endian
508 CONFIG_SYS_FSL_IFC_LE
509 Defines the IFC controller register space as Little Endian
511 CONFIG_SYS_FSL_PBL_PBI
512 It enables addition of RCW (Power on reset configuration) in built image.
513 Please refer doc/README.pblimage for more details
515 CONFIG_SYS_FSL_PBL_RCW
516 It adds PBI(pre-boot instructions) commands in u-boot build image.
517 PBI commands can be used to configure SoC before it starts the execution.
518 Please refer doc/README.pblimage for more details
521 It adds a target to create boot binary having SPL binary in PBI format
522 concatenated with u-boot binary.
524 CONFIG_SYS_FSL_DDR_BE
525 Defines the DDR controller register space as Big Endian
527 CONFIG_SYS_FSL_DDR_LE
528 Defines the DDR controller register space as Little Endian
530 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
531 Physical address from the view of DDR controllers. It is the
532 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
533 it could be different for ARM SoCs.
535 CONFIG_SYS_FSL_DDR_INTLV_256B
536 DDR controller interleaving on 256-byte. This is a special
537 interleaving mode, handled by Dickens for Freescale layerscape
540 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
541 Number of controllers used as main memory.
543 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
544 Number of controllers used for other than main memory.
546 CONFIG_SYS_FSL_SEC_BE
547 Defines the SEC controller register space as Big Endian
549 CONFIG_SYS_FSL_SEC_LE
550 Defines the SEC controller register space as Little Endian
552 - Intel Monahans options:
553 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
555 Defines the Monahans run mode to oscillator
556 ratio. Valid values are 8, 16, 24, 31. The core
557 frequency is this value multiplied by 13 MHz.
559 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
561 Defines the Monahans turbo mode to oscillator
562 ratio. Valid values are 1 (default if undefined) and
563 2. The core frequency as calculated above is multiplied
567 CONFIG_SYS_INIT_SP_OFFSET
569 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
570 pointer. This is needed for the temporary stack before
573 CONFIG_SYS_MIPS_CACHE_MODE
575 Cache operation mode for the MIPS CPU.
576 See also arch/mips/include/asm/mipsregs.h.
578 CONF_CM_CACHABLE_NO_WA
581 CONF_CM_CACHABLE_NONCOHERENT
585 CONF_CM_CACHABLE_ACCELERATED
587 CONFIG_SYS_XWAY_EBU_BOOTCFG
589 Special option for Lantiq XWAY SoCs for booting from NOR flash.
590 See also arch/mips/cpu/mips32/start.S.
592 CONFIG_XWAY_SWAP_BYTES
594 Enable compilation of tools/xway-swap-bytes needed for Lantiq
595 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
596 be swapped if a flash programmer is used.
599 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
601 Select high exception vectors of the ARM core, e.g., do not
602 clear the V bit of the c1 register of CP15.
604 CONFIG_SYS_THUMB_BUILD
606 Use this flag to build U-Boot using the Thumb instruction
607 set for ARM architectures. Thumb instruction set provides
608 better code density. For ARM architectures that support
609 Thumb2 this flag will result in Thumb2 code generated by
612 CONFIG_ARM_ERRATA_716044
613 CONFIG_ARM_ERRATA_742230
614 CONFIG_ARM_ERRATA_743622
615 CONFIG_ARM_ERRATA_751472
616 CONFIG_ARM_ERRATA_794072
617 CONFIG_ARM_ERRATA_761320
619 If set, the workarounds for these ARM errata are applied early
620 during U-Boot startup. Note that these options force the
621 workarounds to be applied; no CPU-type/version detection
622 exists, unlike the similar options in the Linux kernel. Do not
623 set these options unless they apply!
626 Driver model is a new framework for devices in U-Boot
627 introduced in early 2014. U-Boot is being progressively
628 moved over to this. It offers a consistent device structure,
629 supports grouping devices into classes and has built-in
630 handling of platform data and device tree.
632 To enable transition to driver model in a relatively
633 painful fashion, each subsystem can be independently
634 switched between the legacy/ad-hoc approach and the new
635 driver model using the options below. Also, many uclass
636 interfaces include compatibility features which may be
637 removed once the conversion of that subsystem is complete.
638 As a result, the API provided by the subsystem may in fact
639 not change with driver model.
641 See doc/driver-model/README.txt for more information.
645 Enable driver model. This brings in the core support,
646 including scanning of platform data on start-up. If
647 CONFIG_OF_CONTROL is enabled, the device tree will be
648 scanned also when available.
652 Enable driver model test commands. These allow you to print
653 out the driver model tree and the uclasses.
657 Enable some demo devices and the 'demo' command. These are
658 really only useful for playing around while trying to
659 understand driver model in sandbox.
663 Enable driver model in SPL. You will need to provide a
664 suitable malloc() implementation. If you are not using the
665 full malloc() enabled by CONFIG_SYS_SPL_MALLOC_START,
666 consider using CONFIG_SYS_MALLOC_SIMPLE. In that case you
667 must provide CONFIG_SYS_MALLOC_F_LEN to set the size.
668 In most cases driver model will only allocate a few uclasses
669 and devices in SPL, so 1KB should be enable. See
670 CONFIG_SYS_MALLOC_F_LEN for more details on how to enable
675 Enable driver model for serial. This replaces
676 drivers/serial/serial.c with the serial uclass, which
677 implements serial_putc() etc. The uclass interface is
678 defined in include/serial.h.
682 Enable driver model for GPIO access. The standard GPIO
683 interface (gpio_get_value(), etc.) is then implemented by
684 the GPIO uclass. Drivers provide methods to query the
685 particular GPIOs that they provide. The uclass interface
686 is defined in include/asm-generic/gpio.h.
690 Enable driver model for SPI. The SPI slave interface
691 (spi_setup_slave(), spi_xfer(), etc.) is then implemented by
692 the SPI uclass. Drivers provide methods to access the SPI
693 buses that they control. The uclass interface is defined in
694 include/spi.h. The existing spi_slave structure is attached
695 as 'parent data' to every slave on each bus. Slaves
696 typically use driver-private data instead of extending the
701 Enable driver model for SPI flash. This SPI flash interface
702 (spi_flash_probe(), spi_flash_write(), etc.) is then
703 implemented by the SPI flash uclass. There is one standard
704 SPI flash driver which knows how to probe most chips
705 supported by U-Boot. The uclass interface is defined in
706 include/spi_flash.h, but is currently fully compatible
707 with the old interface to avoid confusion and duplication
708 during the transition parent. SPI and SPI flash must be
709 enabled together (it is not possible to use driver model
710 for one and not the other).
714 Enable driver model for the Chrome OS EC interface. This
715 allows the cros_ec SPI driver to operate with CONFIG_DM_SPI
716 but otherwise makes few changes. Since cros_ec also supports
717 I2C and LPC (which don't support driver model yet), a full
718 conversion is not yet possible.
721 ** Code size options: The following options are enabled by
722 default except in SPL. Enable them explicitly to get these
727 Enable the dm_warn() function. This can use up quite a bit
728 of space for its strings.
732 Enable registering a serial device with the stdio library.
734 CONFIG_DM_DEVICE_REMOVE
736 Enable removing of devices.
739 - Linux Kernel Interface:
742 U-Boot stores all clock information in Hz
743 internally. For binary compatibility with older Linux
744 kernels (which expect the clocks passed in the
745 bd_info data to be in MHz) the environment variable
746 "clocks_in_mhz" can be defined so that U-Boot
747 converts clock data to MHZ before passing it to the
749 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
750 "clocks_in_mhz=1" is automatically included in the
753 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
755 When transferring memsize parameter to Linux, some versions
756 expect it to be in bytes, others in MB.
757 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
761 New kernel versions are expecting firmware settings to be
762 passed using flattened device trees (based on open firmware
766 * New libfdt-based support
767 * Adds the "fdt" command
768 * The bootm command automatically updates the fdt
770 OF_CPU - The proper name of the cpus node (only required for
771 MPC512X and MPC5xxx based boards).
772 OF_SOC - The proper name of the soc node (only required for
773 MPC512X and MPC5xxx based boards).
774 OF_TBCLK - The timebase frequency.
775 OF_STDOUT_PATH - The path to the console device
777 boards with QUICC Engines require OF_QE to set UCC MAC
780 CONFIG_OF_BOARD_SETUP
782 Board code has addition modification that it wants to make
783 to the flat device tree before handing it off to the kernel
785 CONFIG_OF_SYSTEM_SETUP
787 Other code has addition modification that it wants to make
788 to the flat device tree before handing it off to the kernel.
789 This causes ft_system_setup() to be called before booting
794 This define fills in the correct boot CPU in the boot
795 param header, the default value is zero if undefined.
799 U-Boot can detect if an IDE device is present or not.
800 If not, and this new config option is activated, U-Boot
801 removes the ATA node from the DTS before booting Linux,
802 so the Linux IDE driver does not probe the device and
803 crash. This is needed for buggy hardware (uc101) where
804 no pull down resistor is connected to the signal IDE5V_DD7.
806 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
808 This setting is mandatory for all boards that have only one
809 machine type and must be used to specify the machine type
810 number as it appears in the ARM machine registry
811 (see http://www.arm.linux.org.uk/developer/machines/).
812 Only boards that have multiple machine types supported
813 in a single configuration file and the machine type is
814 runtime discoverable, do not have to use this setting.
816 - vxWorks boot parameters:
818 bootvx constructs a valid bootline using the following
819 environments variables: bootfile, ipaddr, serverip, hostname.
820 It loads the vxWorks image pointed bootfile.
822 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
823 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
824 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
825 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
827 CONFIG_SYS_VXWORKS_ADD_PARAMS
829 Add it at the end of the bootline. E.g "u=username pw=secret"
831 Note: If a "bootargs" environment is defined, it will overwride
832 the defaults discussed just above.
834 - Cache Configuration:
835 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
836 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
837 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
839 - Cache Configuration for ARM:
840 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
842 CONFIG_SYS_PL310_BASE - Physical base address of PL310
843 controller register space
848 Define this if you want support for Amba PrimeCell PL010 UARTs.
852 Define this if you want support for Amba PrimeCell PL011 UARTs.
856 If you have Amba PrimeCell PL011 UARTs, set this variable to
857 the clock speed of the UARTs.
861 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
862 define this to a list of base addresses for each (supported)
863 port. See e.g. include/configs/versatile.h
865 CONFIG_PL011_SERIAL_RLCR
867 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
868 have separate receive and transmit line control registers. Set
869 this variable to initialize the extra register.
871 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
873 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
874 boot loader that has already initialized the UART. Define this
875 variable to flush the UART at init time.
877 CONFIG_SERIAL_HW_FLOW_CONTROL
879 Define this variable to enable hw flow control in serial driver.
880 Current user of this option is drivers/serial/nsl16550.c driver
883 Depending on board, define exactly one serial port
884 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
885 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
886 console by defining CONFIG_8xx_CONS_NONE
888 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
889 port routines must be defined elsewhere
890 (i.e. serial_init(), serial_getc(), ...)
893 Enables console device for a color framebuffer. Needs following
894 defines (cf. smiLynxEM, i8042)
895 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
897 VIDEO_HW_RECTFILL graphic chip supports
900 VIDEO_HW_BITBLT graphic chip supports
901 bit-blit (cf. smiLynxEM)
902 VIDEO_VISIBLE_COLS visible pixel columns
904 VIDEO_VISIBLE_ROWS visible pixel rows
905 VIDEO_PIXEL_SIZE bytes per pixel
906 VIDEO_DATA_FORMAT graphic data format
907 (0-5, cf. cfb_console.c)
908 VIDEO_FB_ADRS framebuffer address
909 VIDEO_KBD_INIT_FCT keyboard int fct
910 (i.e. i8042_kbd_init())
911 VIDEO_TSTC_FCT test char fct
913 VIDEO_GETC_FCT get char fct
915 CONFIG_CONSOLE_CURSOR cursor drawing on/off
916 (requires blink timer
918 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
919 CONFIG_CONSOLE_TIME display time/date info in
921 (requires CONFIG_CMD_DATE)
922 CONFIG_VIDEO_LOGO display Linux logo in
924 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
925 linux_logo.h for logo.
926 Requires CONFIG_VIDEO_LOGO
927 CONFIG_CONSOLE_EXTRA_INFO
928 additional board info beside
931 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
932 a limited number of ANSI escape sequences (cursor control,
933 erase functions and limited graphics rendition control).
935 When CONFIG_CFB_CONSOLE is defined, video console is
936 default i/o. Serial console can be forced with
937 environment 'console=serial'.
939 When CONFIG_SILENT_CONSOLE is defined, all console
940 messages (by U-Boot and Linux!) can be silenced with
941 the "silent" environment variable. See
942 doc/README.silent for more information.
944 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
946 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
950 CONFIG_BAUDRATE - in bps
951 Select one of the baudrates listed in
952 CONFIG_SYS_BAUDRATE_TABLE, see below.
953 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
955 - Console Rx buffer length
956 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
957 the maximum receive buffer length for the SMC.
958 This option is actual only for 82xx and 8xx possible.
959 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
960 must be defined, to setup the maximum idle timeout for
963 - Pre-Console Buffer:
964 Prior to the console being initialised (i.e. serial UART
965 initialised etc) all console output is silently discarded.
966 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
967 buffer any console messages prior to the console being
968 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
969 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
970 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
971 bytes are output before the console is initialised, the
972 earlier bytes are discarded.
974 'Sane' compilers will generate smaller code if
975 CONFIG_PRE_CON_BUF_SZ is a power of 2
977 - Safe printf() functions
978 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
979 the printf() functions. These are defined in
980 include/vsprintf.h and include snprintf(), vsnprintf() and
981 so on. Code size increase is approximately 300-500 bytes.
982 If this option is not given then these functions will
983 silently discard their buffer size argument - this means
984 you are not getting any overflow checking in this case.
986 - Boot Delay: CONFIG_BOOTDELAY - in seconds
987 Delay before automatically booting the default image;
988 set to -1 to disable autoboot.
989 set to -2 to autoboot with no delay and not check for abort
990 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
992 See doc/README.autoboot for these options that
993 work with CONFIG_BOOTDELAY. None are required.
994 CONFIG_BOOT_RETRY_TIME
995 CONFIG_BOOT_RETRY_MIN
996 CONFIG_AUTOBOOT_KEYED
997 CONFIG_AUTOBOOT_PROMPT
998 CONFIG_AUTOBOOT_DELAY_STR
999 CONFIG_AUTOBOOT_STOP_STR
1000 CONFIG_AUTOBOOT_DELAY_STR2
1001 CONFIG_AUTOBOOT_STOP_STR2
1002 CONFIG_ZERO_BOOTDELAY_CHECK
1003 CONFIG_RESET_TO_RETRY
1007 Only needed when CONFIG_BOOTDELAY is enabled;
1008 define a command string that is automatically executed
1009 when no character is read on the console interface
1010 within "Boot Delay" after reset.
1013 This can be used to pass arguments to the bootm
1014 command. The value of CONFIG_BOOTARGS goes into the
1015 environment value "bootargs".
1017 CONFIG_RAMBOOT and CONFIG_NFSBOOT
1018 The value of these goes into the environment as
1019 "ramboot" and "nfsboot" respectively, and can be used
1020 as a convenience, when switching between booting from
1024 CONFIG_BOOTCOUNT_LIMIT
1025 Implements a mechanism for detecting a repeating reboot
1027 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
1029 CONFIG_BOOTCOUNT_ENV
1030 If no softreset save registers are found on the hardware
1031 "bootcount" is stored in the environment. To prevent a
1032 saveenv on all reboots, the environment variable
1033 "upgrade_available" is used. If "upgrade_available" is
1034 0, "bootcount" is always 0, if "upgrade_available" is
1035 1 "bootcount" is incremented in the environment.
1036 So the Userspace Applikation must set the "upgrade_available"
1037 and "bootcount" variable to 0, if a boot was successfully.
1039 - Pre-Boot Commands:
1042 When this option is #defined, the existence of the
1043 environment variable "preboot" will be checked
1044 immediately before starting the CONFIG_BOOTDELAY
1045 countdown and/or running the auto-boot command resp.
1046 entering interactive mode.
1048 This feature is especially useful when "preboot" is
1049 automatically generated or modified. For an example
1050 see the LWMON board specific code: here "preboot" is
1051 modified when the user holds down a certain
1052 combination of keys on the (special) keyboard when
1055 - Serial Download Echo Mode:
1057 If defined to 1, all characters received during a
1058 serial download (using the "loads" command) are
1059 echoed back. This might be needed by some terminal
1060 emulations (like "cu"), but may as well just take
1061 time on others. This setting #define's the initial
1062 value of the "loads_echo" environment variable.
1064 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
1065 CONFIG_KGDB_BAUDRATE
1066 Select one of the baudrates listed in
1067 CONFIG_SYS_BAUDRATE_TABLE, see below.
1069 - Monitor Functions:
1070 Monitor commands can be included or excluded
1071 from the build by using the #include files
1072 <config_cmd_all.h> and #undef'ing unwanted
1073 commands, or using <config_cmd_default.h>
1074 and augmenting with additional #define's
1075 for wanted commands.
1077 The default command configuration includes all commands
1078 except those marked below with a "*".
1080 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
1081 CONFIG_CMD_ASKENV * ask for env variable
1082 CONFIG_CMD_BDI bdinfo
1083 CONFIG_CMD_BEDBUG * Include BedBug Debugger
1084 CONFIG_CMD_BMP * BMP support
1085 CONFIG_CMD_BSP * Board specific commands
1086 CONFIG_CMD_BOOTD bootd
1087 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
1088 CONFIG_CMD_CACHE * icache, dcache
1089 CONFIG_CMD_CLK * clock command support
1090 CONFIG_CMD_CONSOLE coninfo
1091 CONFIG_CMD_CRC32 * crc32
1092 CONFIG_CMD_DATE * support for RTC, date/time...
1093 CONFIG_CMD_DHCP * DHCP support
1094 CONFIG_CMD_DIAG * Diagnostics
1095 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
1096 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1097 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1098 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1099 CONFIG_CMD_DTT * Digital Therm and Thermostat
1100 CONFIG_CMD_ECHO echo arguments
1101 CONFIG_CMD_EDITENV edit env variable
1102 CONFIG_CMD_EEPROM * EEPROM read/write support
1103 CONFIG_CMD_ELF * bootelf, bootvx
1104 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1105 CONFIG_CMD_ENV_FLAGS * display details about env flags
1106 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1107 CONFIG_CMD_EXPORTENV * export the environment
1108 CONFIG_CMD_EXT2 * ext2 command support
1109 CONFIG_CMD_EXT4 * ext4 command support
1110 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1111 that work for multiple fs types
1112 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1113 CONFIG_CMD_SAVEENV saveenv
1114 CONFIG_CMD_FDC * Floppy Disk Support
1115 CONFIG_CMD_FAT * FAT command support
1116 CONFIG_CMD_FLASH flinfo, erase, protect
1117 CONFIG_CMD_FPGA FPGA device initialization support
1118 CONFIG_CMD_FUSE * Device fuse support
1119 CONFIG_CMD_GETTIME * Get time since boot
1120 CONFIG_CMD_GO * the 'go' command (exec code)
1121 CONFIG_CMD_GREPENV * search environment
1122 CONFIG_CMD_HASH * calculate hash / digest
1123 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
1124 CONFIG_CMD_I2C * I2C serial bus support
1125 CONFIG_CMD_IDE * IDE harddisk support
1126 CONFIG_CMD_IMI iminfo
1127 CONFIG_CMD_IMLS List all images found in NOR flash
1128 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1129 CONFIG_CMD_IMMAP * IMMR dump support
1130 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1131 CONFIG_CMD_IMPORTENV * import an environment
1132 CONFIG_CMD_INI * import data from an ini file into the env
1133 CONFIG_CMD_IRQ * irqinfo
1134 CONFIG_CMD_ITEST Integer/string test of 2 values
1135 CONFIG_CMD_JFFS2 * JFFS2 Support
1136 CONFIG_CMD_KGDB * kgdb
1137 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1138 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1140 CONFIG_CMD_LOADB loadb
1141 CONFIG_CMD_LOADS loads
1142 CONFIG_CMD_MD5SUM * print md5 message digest
1143 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1144 CONFIG_CMD_MEMINFO * Display detailed memory information
1145 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1147 CONFIG_CMD_MEMTEST * mtest
1148 CONFIG_CMD_MISC Misc functions like sleep etc
1149 CONFIG_CMD_MMC * MMC memory mapped support
1150 CONFIG_CMD_MII * MII utility commands
1151 CONFIG_CMD_MTDPARTS * MTD partition support
1152 CONFIG_CMD_NAND * NAND support
1153 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1154 CONFIG_CMD_NFS NFS support
1155 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1156 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1157 CONFIG_CMD_PCI * pciinfo
1158 CONFIG_CMD_PCMCIA * PCMCIA support
1159 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1161 CONFIG_CMD_PORTIO * Port I/O
1162 CONFIG_CMD_READ * Read raw data from partition
1163 CONFIG_CMD_REGINFO * Register dump
1164 CONFIG_CMD_RUN run command in env variable
1165 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1166 CONFIG_CMD_SAVES * save S record dump
1167 CONFIG_CMD_SCSI * SCSI Support
1168 CONFIG_CMD_SDRAM * print SDRAM configuration information
1169 (requires CONFIG_CMD_I2C)
1170 CONFIG_CMD_SETGETDCR Support for DCR Register access
1172 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1173 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1174 (requires CONFIG_CMD_MEMORY)
1175 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1176 CONFIG_CMD_SOURCE "source" command Support
1177 CONFIG_CMD_SPI * SPI serial bus support
1178 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1179 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1180 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1181 CONFIG_CMD_TIMER * access to the system tick timer
1182 CONFIG_CMD_USB * USB support
1183 CONFIG_CMD_CDP * Cisco Discover Protocol support
1184 CONFIG_CMD_MFSL * Microblaze FSL support
1185 CONFIG_CMD_XIMG Load part of Multi Image
1186 CONFIG_CMD_UUID * Generate random UUID or GUID string
1188 EXAMPLE: If you want all functions except of network
1189 support you can write:
1191 #include "config_cmd_all.h"
1192 #undef CONFIG_CMD_NET
1195 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1197 Note: Don't enable the "icache" and "dcache" commands
1198 (configuration option CONFIG_CMD_CACHE) unless you know
1199 what you (and your U-Boot users) are doing. Data
1200 cache cannot be enabled on systems like the 8xx or
1201 8260 (where accesses to the IMMR region must be
1202 uncached), and it cannot be disabled on all other
1203 systems where we (mis-) use the data cache to hold an
1204 initial stack and some data.
1207 XXX - this list needs to get updated!
1209 - Regular expression support:
1211 If this variable is defined, U-Boot is linked against
1212 the SLRE (Super Light Regular Expression) library,
1213 which adds regex support to some commands, as for
1214 example "env grep" and "setexpr".
1218 If this variable is defined, U-Boot will use a device tree
1219 to configure its devices, instead of relying on statically
1220 compiled #defines in the board file. This option is
1221 experimental and only available on a few boards. The device
1222 tree is available in the global data as gd->fdt_blob.
1224 U-Boot needs to get its device tree from somewhere. This can
1225 be done using one of the two options below:
1228 If this variable is defined, U-Boot will embed a device tree
1229 binary in its image. This device tree file should be in the
1230 board directory and called <soc>-<board>.dts. The binary file
1231 is then picked up in board_init_f() and made available through
1232 the global data structure as gd->blob.
1235 If this variable is defined, U-Boot will build a device tree
1236 binary. It will be called u-boot.dtb. Architecture-specific
1237 code will locate it at run-time. Generally this works by:
1239 cat u-boot.bin u-boot.dtb >image.bin
1241 and in fact, U-Boot does this for you, creating a file called
1242 u-boot-dtb.bin which is useful in the common case. You can
1243 still use the individual files if you need something more
1248 If this variable is defined, it enables watchdog
1249 support for the SoC. There must be support in the SoC
1250 specific code for a watchdog. For the 8xx and 8260
1251 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1252 register. When supported for a specific SoC is
1253 available, then no further board specific code should
1254 be needed to use it.
1257 When using a watchdog circuitry external to the used
1258 SoC, then define this variable and provide board
1259 specific code for the "hw_watchdog_reset" function.
1262 CONFIG_VERSION_VARIABLE
1263 If this variable is defined, an environment variable
1264 named "ver" is created by U-Boot showing the U-Boot
1265 version as printed by the "version" command.
1266 Any change to this variable will be reverted at the
1271 When CONFIG_CMD_DATE is selected, the type of the RTC
1272 has to be selected, too. Define exactly one of the
1275 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1276 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1277 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1278 CONFIG_RTC_MC146818 - use MC146818 RTC
1279 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1280 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1281 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1282 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1283 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1284 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1285 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1286 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1287 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1290 Note that if the RTC uses I2C, then the I2C interface
1291 must also be configured. See I2C Support, below.
1294 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1296 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1297 chip-ngpio pairs that tell the PCA953X driver the number of
1298 pins supported by a particular chip.
1300 Note that if the GPIO device uses I2C, then the I2C interface
1301 must also be configured. See I2C Support, below.
1304 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1305 accesses and can checksum them or write a list of them out
1306 to memory. See the 'iotrace' command for details. This is
1307 useful for testing device drivers since it can confirm that
1308 the driver behaves the same way before and after a code
1309 change. Currently this is supported on sandbox and arm. To
1310 add support for your architecture, add '#include <iotrace.h>'
1311 to the bottom of arch/<arch>/include/asm/io.h and test.
1313 Example output from the 'iotrace stats' command is below.
1314 Note that if the trace buffer is exhausted, the checksum will
1315 still continue to operate.
1318 Start: 10000000 (buffer start address)
1319 Size: 00010000 (buffer size)
1320 Offset: 00000120 (current buffer offset)
1321 Output: 10000120 (start + offset)
1322 Count: 00000018 (number of trace records)
1323 CRC32: 9526fb66 (CRC32 of all trace records)
1325 - Timestamp Support:
1327 When CONFIG_TIMESTAMP is selected, the timestamp
1328 (date and time) of an image is printed by image
1329 commands like bootm or iminfo. This option is
1330 automatically enabled when you select CONFIG_CMD_DATE .
1332 - Partition Labels (disklabels) Supported:
1333 Zero or more of the following:
1334 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1335 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1336 Intel architecture, USB sticks, etc.
1337 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1338 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1339 bootloader. Note 2TB partition limit; see
1341 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1343 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1344 CONFIG_CMD_SCSI) you must configure support for at
1345 least one non-MTD partition type as well.
1348 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1349 board configurations files but used nowhere!
1351 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1352 be performed by calling the function
1353 ide_set_reset(int reset)
1354 which has to be defined in a board specific file
1359 Set this to enable ATAPI support.
1364 Set this to enable support for disks larger than 137GB
1365 Also look at CONFIG_SYS_64BIT_LBA.
1366 Whithout these , LBA48 support uses 32bit variables and will 'only'
1367 support disks up to 2.1TB.
1369 CONFIG_SYS_64BIT_LBA:
1370 When enabled, makes the IDE subsystem use 64bit sector addresses.
1374 At the moment only there is only support for the
1375 SYM53C8XX SCSI controller; define
1376 CONFIG_SCSI_SYM53C8XX to enable it.
1378 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1379 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1380 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1381 maximum numbers of LUNs, SCSI ID's and target
1383 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1385 The environment variable 'scsidevs' is set to the number of
1386 SCSI devices found during the last scan.
1388 - NETWORK Support (PCI):
1390 Support for Intel 8254x/8257x gigabit chips.
1393 Utility code for direct access to the SPI bus on Intel 8257x.
1394 This does not do anything useful unless you set at least one
1395 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1397 CONFIG_E1000_SPI_GENERIC
1398 Allow generic access to the SPI bus on the Intel 8257x, for
1399 example with the "sspi" command.
1402 Management command for E1000 devices. When used on devices
1403 with SPI support you can reprogram the EEPROM from U-Boot.
1405 CONFIG_E1000_FALLBACK_MAC
1406 default MAC for empty EEPROM after production.
1409 Support for Intel 82557/82559/82559ER chips.
1410 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1411 write routine for first time initialisation.
1414 Support for Digital 2114x chips.
1415 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1416 modem chip initialisation (KS8761/QS6611).
1419 Support for National dp83815 chips.
1422 Support for National dp8382[01] gigabit chips.
1424 - NETWORK Support (other):
1426 CONFIG_DRIVER_AT91EMAC
1427 Support for AT91RM9200 EMAC.
1430 Define this to use reduced MII inteface
1432 CONFIG_DRIVER_AT91EMAC_QUIET
1433 If this defined, the driver is quiet.
1434 The driver doen't show link status messages.
1436 CONFIG_CALXEDA_XGMAC
1437 Support for the Calxeda XGMAC device
1440 Support for SMSC's LAN91C96 chips.
1442 CONFIG_LAN91C96_BASE
1443 Define this to hold the physical address
1444 of the LAN91C96's I/O space
1446 CONFIG_LAN91C96_USE_32_BIT
1447 Define this to enable 32 bit addressing
1450 Support for SMSC's LAN91C111 chip
1452 CONFIG_SMC91111_BASE
1453 Define this to hold the physical address
1454 of the device (I/O space)
1456 CONFIG_SMC_USE_32_BIT
1457 Define this if data bus is 32 bits
1459 CONFIG_SMC_USE_IOFUNCS
1460 Define this to use i/o functions instead of macros
1461 (some hardware wont work with macros)
1463 CONFIG_DRIVER_TI_EMAC
1464 Support for davinci emac
1466 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1467 Define this if you have more then 3 PHYs.
1470 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1472 CONFIG_FTGMAC100_EGIGA
1473 Define this to use GE link update with gigabit PHY.
1474 Define this if FTGMAC100 is connected to gigabit PHY.
1475 If your system has 10/100 PHY only, it might not occur
1476 wrong behavior. Because PHY usually return timeout or
1477 useless data when polling gigabit status and gigabit
1478 control registers. This behavior won't affect the
1479 correctnessof 10/100 link speed update.
1482 Support for SMSC's LAN911x and LAN921x chips
1485 Define this to hold the physical address
1486 of the device (I/O space)
1488 CONFIG_SMC911X_32_BIT
1489 Define this if data bus is 32 bits
1491 CONFIG_SMC911X_16_BIT
1492 Define this if data bus is 16 bits. If your processor
1493 automatically converts one 32 bit word to two 16 bit
1494 words you may also try CONFIG_SMC911X_32_BIT.
1497 Support for Renesas on-chip Ethernet controller
1499 CONFIG_SH_ETHER_USE_PORT
1500 Define the number of ports to be used
1502 CONFIG_SH_ETHER_PHY_ADDR
1503 Define the ETH PHY's address
1505 CONFIG_SH_ETHER_CACHE_WRITEBACK
1506 If this option is set, the driver enables cache flush.
1510 Support for PWM modul on the imx6.
1514 Support TPM devices.
1517 Support for i2c bus TPM devices. Only one device
1518 per system is supported at this time.
1520 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1521 Define the the i2c bus number for the TPM device
1523 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1524 Define the TPM's address on the i2c bus
1526 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1527 Define the burst count bytes upper limit
1529 CONFIG_TPM_ATMEL_TWI
1530 Support for Atmel TWI TPM device. Requires I2C support.
1533 Support for generic parallel port TPM devices. Only one device
1534 per system is supported at this time.
1536 CONFIG_TPM_TIS_BASE_ADDRESS
1537 Base address where the generic TPM device is mapped
1538 to. Contemporary x86 systems usually map it at
1542 Add tpm monitor functions.
1543 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1544 provides monitor access to authorized functions.
1547 Define this to enable the TPM support library which provides
1548 functional interfaces to some TPM commands.
1549 Requires support for a TPM device.
1551 CONFIG_TPM_AUTH_SESSIONS
1552 Define this to enable authorized functions in the TPM library.
1553 Requires CONFIG_TPM and CONFIG_SHA1.
1556 At the moment only the UHCI host controller is
1557 supported (PIP405, MIP405, MPC5200); define
1558 CONFIG_USB_UHCI to enable it.
1559 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1560 and define CONFIG_USB_STORAGE to enable the USB
1563 Supported are USB Keyboards and USB Floppy drives
1565 MPC5200 USB requires additional defines:
1567 for 528 MHz Clock: 0x0001bbbb
1571 for differential drivers: 0x00001000
1572 for single ended drivers: 0x00005000
1573 for differential drivers on PSC3: 0x00000100
1574 for single ended drivers on PSC3: 0x00004100
1575 CONFIG_SYS_USB_EVENT_POLL
1576 May be defined to allow interrupt polling
1577 instead of using asynchronous interrupts
1579 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1580 txfilltuning field in the EHCI controller on reset.
1582 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1583 HW module registers.
1586 Define the below if you wish to use the USB console.
1587 Once firmware is rebuilt from a serial console issue the
1588 command "setenv stdin usbtty; setenv stdout usbtty" and
1589 attach your USB cable. The Unix command "dmesg" should print
1590 it has found a new device. The environment variable usbtty
1591 can be set to gserial or cdc_acm to enable your device to
1592 appear to a USB host as a Linux gserial device or a
1593 Common Device Class Abstract Control Model serial device.
1594 If you select usbtty = gserial you should be able to enumerate
1596 # modprobe usbserial vendor=0xVendorID product=0xProductID
1597 else if using cdc_acm, simply setting the environment
1598 variable usbtty to be cdc_acm should suffice. The following
1599 might be defined in YourBoardName.h
1602 Define this to build a UDC device
1605 Define this to have a tty type of device available to
1606 talk to the UDC device
1609 Define this to enable the high speed support for usb
1610 device and usbtty. If this feature is enabled, a routine
1611 int is_usbd_high_speed(void)
1612 also needs to be defined by the driver to dynamically poll
1613 whether the enumeration has succeded at high speed or full
1616 CONFIG_SYS_CONSOLE_IS_IN_ENV
1617 Define this if you want stdin, stdout &/or stderr to
1621 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1622 Derive USB clock from external clock "blah"
1623 - CONFIG_SYS_USB_EXTC_CLK 0x02
1625 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1626 Derive USB clock from brgclk
1627 - CONFIG_SYS_USB_BRG_CLK 0x04
1629 If you have a USB-IF assigned VendorID then you may wish to
1630 define your own vendor specific values either in BoardName.h
1631 or directly in usbd_vendor_info.h. If you don't define
1632 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1633 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1634 should pretend to be a Linux device to it's target host.
1636 CONFIG_USBD_MANUFACTURER
1637 Define this string as the name of your company for
1638 - CONFIG_USBD_MANUFACTURER "my company"
1640 CONFIG_USBD_PRODUCT_NAME
1641 Define this string as the name of your product
1642 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1644 CONFIG_USBD_VENDORID
1645 Define this as your assigned Vendor ID from the USB
1646 Implementors Forum. This *must* be a genuine Vendor ID
1647 to avoid polluting the USB namespace.
1648 - CONFIG_USBD_VENDORID 0xFFFF
1650 CONFIG_USBD_PRODUCTID
1651 Define this as the unique Product ID
1653 - CONFIG_USBD_PRODUCTID 0xFFFF
1655 - ULPI Layer Support:
1656 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1657 the generic ULPI layer. The generic layer accesses the ULPI PHY
1658 via the platform viewport, so you need both the genric layer and
1659 the viewport enabled. Currently only Chipidea/ARC based
1660 viewport is supported.
1661 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1662 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1663 If your ULPI phy needs a different reference clock than the
1664 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1665 the appropriate value in Hz.
1668 The MMC controller on the Intel PXA is supported. To
1669 enable this define CONFIG_MMC. The MMC can be
1670 accessed from the boot prompt by mapping the device
1671 to physical memory similar to flash. Command line is
1672 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1673 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1676 Support for Renesas on-chip MMCIF controller
1678 CONFIG_SH_MMCIF_ADDR
1679 Define the base address of MMCIF registers
1682 Define the clock frequency for MMCIF
1685 Enable the generic MMC driver
1687 CONFIG_SUPPORT_EMMC_BOOT
1688 Enable some additional features of the eMMC boot partitions.
1690 CONFIG_SUPPORT_EMMC_RPMB
1691 Enable the commands for reading, writing and programming the
1692 key for the Replay Protection Memory Block partition in eMMC.
1694 - USB Device Firmware Update (DFU) class support:
1696 This enables the USB portion of the DFU USB class
1699 This enables the command "dfu" which is used to have
1700 U-Boot create a DFU class device via USB. This command
1701 requires that the "dfu_alt_info" environment variable be
1702 set and define the alt settings to expose to the host.
1705 This enables support for exposing (e)MMC devices via DFU.
1708 This enables support for exposing NAND devices via DFU.
1711 This enables support for exposing RAM via DFU.
1712 Note: DFU spec refer to non-volatile memory usage, but
1713 allow usages beyond the scope of spec - here RAM usage,
1714 one that would help mostly the developer.
1716 CONFIG_SYS_DFU_DATA_BUF_SIZE
1717 Dfu transfer uses a buffer before writing data to the
1718 raw storage device. Make the size (in bytes) of this buffer
1719 configurable. The size of this buffer is also configurable
1720 through the "dfu_bufsiz" environment variable.
1722 CONFIG_SYS_DFU_MAX_FILE_SIZE
1723 When updating files rather than the raw storage device,
1724 we use a static buffer to copy the file into and then write
1725 the buffer once we've been given the whole file. Define
1726 this to the maximum filesize (in bytes) for the buffer.
1727 Default is 4 MiB if undefined.
1729 DFU_DEFAULT_POLL_TIMEOUT
1730 Poll timeout [ms], is the timeout a device can send to the
1731 host. The host must wait for this timeout before sending
1732 a subsequent DFU_GET_STATUS request to the device.
1734 DFU_MANIFEST_POLL_TIMEOUT
1735 Poll timeout [ms], which the device sends to the host when
1736 entering dfuMANIFEST state. Host waits this timeout, before
1737 sending again an USB request to the device.
1739 - USB Device Android Fastboot support:
1741 This enables the command "fastboot" which enables the Android
1742 fastboot mode for the platform's USB device. Fastboot is a USB
1743 protocol for downloading images, flashing and device control
1744 used on Android devices.
1745 See doc/README.android-fastboot for more information.
1747 CONFIG_ANDROID_BOOT_IMAGE
1748 This enables support for booting images which use the Android
1749 image format header.
1751 CONFIG_USB_FASTBOOT_BUF_ADDR
1752 The fastboot protocol requires a large memory buffer for
1753 downloads. Define this to the starting RAM address to use for
1756 CONFIG_USB_FASTBOOT_BUF_SIZE
1757 The fastboot protocol requires a large memory buffer for
1758 downloads. This buffer should be as large as possible for a
1759 platform. Define this to the size available RAM for fastboot.
1761 CONFIG_FASTBOOT_FLASH
1762 The fastboot protocol includes a "flash" command for writing
1763 the downloaded image to a non-volatile storage device. Define
1764 this to enable the "fastboot flash" command.
1766 CONFIG_FASTBOOT_FLASH_MMC_DEV
1767 The fastboot "flash" command requires additional information
1768 regarding the non-volatile storage device. Define this to
1769 the eMMC device that fastboot should use to store the image.
1771 CONFIG_FASTBOOT_GPT_NAME
1772 The fastboot "flash" command supports writing the downloaded
1773 image to the Protective MBR and the Primary GUID Partition
1774 Table. (Additionally, this downloaded image is post-processed
1775 to generate and write the Backup GUID Partition Table.)
1776 This occurs when the specified "partition name" on the
1777 "fastboot flash" command line matches this value.
1778 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1780 - Journaling Flash filesystem support:
1781 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1782 CONFIG_JFFS2_NAND_DEV
1783 Define these for a default partition on a NAND device
1785 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1786 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1787 Define these for a default partition on a NOR device
1789 CONFIG_SYS_JFFS_CUSTOM_PART
1790 Define this to create an own partition. You have to provide a
1791 function struct part_info* jffs2_part_info(int part_num)
1793 If you define only one JFFS2 partition you may also want to
1794 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1795 to disable the command chpart. This is the default when you
1796 have not defined a custom partition
1798 - FAT(File Allocation Table) filesystem write function support:
1801 Define this to enable support for saving memory data as a
1802 file in FAT formatted partition.
1804 This will also enable the command "fatwrite" enabling the
1805 user to write files to FAT.
1807 CBFS (Coreboot Filesystem) support
1810 Define this to enable support for reading from a Coreboot
1811 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1814 - FAT(File Allocation Table) filesystem cluster size:
1815 CONFIG_FS_FAT_MAX_CLUSTSIZE
1817 Define the max cluster size for fat operations else
1818 a default value of 65536 will be defined.
1823 Define this to enable standard (PC-Style) keyboard
1827 Standard PC keyboard driver with US (is default) and
1828 GERMAN key layout (switch via environment 'keymap=de') support.
1829 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1830 for cfb_console. Supports cursor blinking.
1833 Enables a Chrome OS keyboard using the CROS_EC interface.
1834 This uses CROS_EC to communicate with a second microcontroller
1835 which provides key scans on request.
1840 Define this to enable video support (for output to
1843 CONFIG_VIDEO_CT69000
1845 Enable Chips & Technologies 69000 Video chip
1847 CONFIG_VIDEO_SMI_LYNXEM
1848 Enable Silicon Motion SMI 712/710/810 Video chip. The
1849 video output is selected via environment 'videoout'
1850 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1853 For the CT69000 and SMI_LYNXEM drivers, videomode is
1854 selected via environment 'videomode'. Two different ways
1856 - "videomode=num" 'num' is a standard LiLo mode numbers.
1857 Following standard modes are supported (* is default):
1859 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1860 -------------+---------------------------------------------
1861 8 bits | 0x301* 0x303 0x305 0x161 0x307
1862 15 bits | 0x310 0x313 0x316 0x162 0x319
1863 16 bits | 0x311 0x314 0x317 0x163 0x31A
1864 24 bits | 0x312 0x315 0x318 ? 0x31B
1865 -------------+---------------------------------------------
1866 (i.e. setenv videomode 317; saveenv; reset;)
1868 - "videomode=bootargs" all the video parameters are parsed
1869 from the bootargs. (See drivers/video/videomodes.c)
1872 CONFIG_VIDEO_SED13806
1873 Enable Epson SED13806 driver. This driver supports 8bpp
1874 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1875 or CONFIG_VIDEO_SED13806_16BPP
1878 Enable the Freescale DIU video driver. Reference boards for
1879 SOCs that have a DIU should define this macro to enable DIU
1880 support, and should also define these other macros:
1886 CONFIG_VIDEO_SW_CURSOR
1887 CONFIG_VGA_AS_SINGLE_DEVICE
1889 CONFIG_VIDEO_BMP_LOGO
1891 The DIU driver will look for the 'video-mode' environment
1892 variable, and if defined, enable the DIU as a console during
1893 boot. See the documentation file README.video for a
1894 description of this variable.
1898 Enable the VGA video / BIOS for x86. The alternative if you
1899 are using coreboot is to use the coreboot frame buffer
1906 Define this to enable a custom keyboard support.
1907 This simply calls drv_keyboard_init() which must be
1908 defined in your board-specific files.
1909 The only board using this so far is RBC823.
1911 - LCD Support: CONFIG_LCD
1913 Define this to enable LCD support (for output to LCD
1914 display); also select one of the supported displays
1915 by defining one of these:
1919 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1921 CONFIG_NEC_NL6448AC33:
1923 NEC NL6448AC33-18. Active, color, single scan.
1925 CONFIG_NEC_NL6448BC20
1927 NEC NL6448BC20-08. 6.5", 640x480.
1928 Active, color, single scan.
1930 CONFIG_NEC_NL6448BC33_54
1932 NEC NL6448BC33-54. 10.4", 640x480.
1933 Active, color, single scan.
1937 Sharp 320x240. Active, color, single scan.
1938 It isn't 16x9, and I am not sure what it is.
1940 CONFIG_SHARP_LQ64D341
1942 Sharp LQ64D341 display, 640x480.
1943 Active, color, single scan.
1947 HLD1045 display, 640x480.
1948 Active, color, single scan.
1952 Optrex CBL50840-2 NF-FW 99 22 M5
1954 Hitachi LMG6912RPFC-00T
1958 320x240. Black & white.
1960 Normally display is black on white background; define
1961 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1963 CONFIG_LCD_ALIGNMENT
1965 Normally the LCD is page-aligned (typically 4KB). If this is
1966 defined then the LCD will be aligned to this value instead.
1967 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1968 here, since it is cheaper to change data cache settings on
1969 a per-section basis.
1971 CONFIG_CONSOLE_SCROLL_LINES
1973 When the console need to be scrolled, this is the number of
1974 lines to scroll by. It defaults to 1. Increasing this makes
1975 the console jump but can help speed up operation when scrolling
1980 Support drawing of RLE8-compressed bitmaps on the LCD.
1984 Enables an 'i2c edid' command which can read EDID
1985 information over I2C from an attached LCD display.
1987 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1989 If this option is set, the environment is checked for
1990 a variable "splashimage". If found, the usual display
1991 of logo, copyright and system information on the LCD
1992 is suppressed and the BMP image at the address
1993 specified in "splashimage" is loaded instead. The
1994 console is redirected to the "nulldev", too. This
1995 allows for a "silent" boot where a splash screen is
1996 loaded very quickly after power-on.
1998 CONFIG_SPLASHIMAGE_GUARD
2000 If this option is set, then U-Boot will prevent the environment
2001 variable "splashimage" from being set to a problematic address
2002 (see README.displaying-bmps).
2003 This option is useful for targets where, due to alignment
2004 restrictions, an improperly aligned BMP image will cause a data
2005 abort. If you think you will not have problems with unaligned
2006 accesses (for example because your toolchain prevents them)
2007 there is no need to set this option.
2009 CONFIG_SPLASH_SCREEN_ALIGN
2011 If this option is set the splash image can be freely positioned
2012 on the screen. Environment variable "splashpos" specifies the
2013 position as "x,y". If a positive number is given it is used as
2014 number of pixel from left/top. If a negative number is given it
2015 is used as number of pixel from right/bottom. You can also
2016 specify 'm' for centering the image.
2019 setenv splashpos m,m
2020 => image at center of screen
2022 setenv splashpos 30,20
2023 => image at x = 30 and y = 20
2025 setenv splashpos -10,m
2026 => vertically centered image
2027 at x = dspWidth - bmpWidth - 9
2029 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
2031 If this option is set, additionally to standard BMP
2032 images, gzipped BMP images can be displayed via the
2033 splashscreen support or the bmp command.
2035 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
2037 If this option is set, 8-bit RLE compressed BMP images
2038 can be displayed via the splashscreen support or the
2041 - Do compressing for memory range:
2044 If this option is set, it would use zlib deflate method
2045 to compress the specified memory at its best effort.
2047 - Compression support:
2050 Enabled by default to support gzip compressed images.
2054 If this option is set, support for bzip2 compressed
2055 images is included. If not, only uncompressed and gzip
2056 compressed images are supported.
2058 NOTE: the bzip2 algorithm requires a lot of RAM, so
2059 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
2064 If this option is set, support for lzma compressed
2067 Note: The LZMA algorithm adds between 2 and 4KB of code and it
2068 requires an amount of dynamic memory that is given by the
2071 (1846 + 768 << (lc + lp)) * sizeof(uint16)
2073 Where lc and lp stand for, respectively, Literal context bits
2074 and Literal pos bits.
2076 This value is upper-bounded by 14MB in the worst case. Anyway,
2077 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
2078 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
2079 a very small buffer.
2081 Use the lzmainfo tool to determinate the lc and lp values and
2082 then calculate the amount of needed dynamic memory (ensuring
2083 the appropriate CONFIG_SYS_MALLOC_LEN value).
2087 If this option is set, support for LZO compressed images
2093 The address of PHY on MII bus.
2095 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2097 The clock frequency of the MII bus
2101 If this option is set, support for speed/duplex
2102 detection of gigabit PHY is included.
2104 CONFIG_PHY_RESET_DELAY
2106 Some PHY like Intel LXT971A need extra delay after
2107 reset before any MII register access is possible.
2108 For such PHY, set this option to the usec delay
2109 required. (minimum 300usec for LXT971A)
2111 CONFIG_PHY_CMD_DELAY (ppc4xx)
2113 Some PHY like Intel LXT971A need extra delay after
2114 command issued before MII status register can be read
2124 Define a default value for Ethernet address to use
2125 for the respective Ethernet interface, in case this
2126 is not determined automatically.
2131 Define a default value for the IP address to use for
2132 the default Ethernet interface, in case this is not
2133 determined through e.g. bootp.
2134 (Environment variable "ipaddr")
2136 - Server IP address:
2139 Defines a default value for the IP address of a TFTP
2140 server to contact when using the "tftboot" command.
2141 (Environment variable "serverip")
2143 CONFIG_KEEP_SERVERADDR
2145 Keeps the server's MAC address, in the env 'serveraddr'
2146 for passing to bootargs (like Linux's netconsole option)
2148 - Gateway IP address:
2151 Defines a default value for the IP address of the
2152 default router where packets to other networks are
2154 (Environment variable "gatewayip")
2159 Defines a default value for the subnet mask (or
2160 routing prefix) which is used to determine if an IP
2161 address belongs to the local subnet or needs to be
2162 forwarded through a router.
2163 (Environment variable "netmask")
2165 - Multicast TFTP Mode:
2168 Defines whether you want to support multicast TFTP as per
2169 rfc-2090; for example to work with atftp. Lets lots of targets
2170 tftp down the same boot image concurrently. Note: the Ethernet
2171 driver in use must provide a function: mcast() to join/leave a
2174 - BOOTP Recovery Mode:
2175 CONFIG_BOOTP_RANDOM_DELAY
2177 If you have many targets in a network that try to
2178 boot using BOOTP, you may want to avoid that all
2179 systems send out BOOTP requests at precisely the same
2180 moment (which would happen for instance at recovery
2181 from a power failure, when all systems will try to
2182 boot, thus flooding the BOOTP server. Defining
2183 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2184 inserted before sending out BOOTP requests. The
2185 following delays are inserted then:
2187 1st BOOTP request: delay 0 ... 1 sec
2188 2nd BOOTP request: delay 0 ... 2 sec
2189 3rd BOOTP request: delay 0 ... 4 sec
2191 BOOTP requests: delay 0 ... 8 sec
2193 CONFIG_BOOTP_ID_CACHE_SIZE
2195 BOOTP packets are uniquely identified using a 32-bit ID. The
2196 server will copy the ID from client requests to responses and
2197 U-Boot will use this to determine if it is the destination of
2198 an incoming response. Some servers will check that addresses
2199 aren't in use before handing them out (usually using an ARP
2200 ping) and therefore take up to a few hundred milliseconds to
2201 respond. Network congestion may also influence the time it
2202 takes for a response to make it back to the client. If that
2203 time is too long, U-Boot will retransmit requests. In order
2204 to allow earlier responses to still be accepted after these
2205 retransmissions, U-Boot's BOOTP client keeps a small cache of
2206 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2207 cache. The default is to keep IDs for up to four outstanding
2208 requests. Increasing this will allow U-Boot to accept offers
2209 from a BOOTP client in networks with unusually high latency.
2211 - DHCP Advanced Options:
2212 You can fine tune the DHCP functionality by defining
2213 CONFIG_BOOTP_* symbols:
2215 CONFIG_BOOTP_SUBNETMASK
2216 CONFIG_BOOTP_GATEWAY
2217 CONFIG_BOOTP_HOSTNAME
2218 CONFIG_BOOTP_NISDOMAIN
2219 CONFIG_BOOTP_BOOTPATH
2220 CONFIG_BOOTP_BOOTFILESIZE
2223 CONFIG_BOOTP_SEND_HOSTNAME
2224 CONFIG_BOOTP_NTPSERVER
2225 CONFIG_BOOTP_TIMEOFFSET
2226 CONFIG_BOOTP_VENDOREX
2227 CONFIG_BOOTP_MAY_FAIL
2229 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2230 environment variable, not the BOOTP server.
2232 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2233 after the configured retry count, the call will fail
2234 instead of starting over. This can be used to fail over
2235 to Link-local IP address configuration if the DHCP server
2238 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2239 serverip from a DHCP server, it is possible that more
2240 than one DNS serverip is offered to the client.
2241 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2242 serverip will be stored in the additional environment
2243 variable "dnsip2". The first DNS serverip is always
2244 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2247 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2248 to do a dynamic update of a DNS server. To do this, they
2249 need the hostname of the DHCP requester.
2250 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2251 of the "hostname" environment variable is passed as
2252 option 12 to the DHCP server.
2254 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2256 A 32bit value in microseconds for a delay between
2257 receiving a "DHCP Offer" and sending the "DHCP Request".
2258 This fixes a problem with certain DHCP servers that don't
2259 respond 100% of the time to a "DHCP request". E.g. On an
2260 AT91RM9200 processor running at 180MHz, this delay needed
2261 to be *at least* 15,000 usec before a Windows Server 2003
2262 DHCP server would reply 100% of the time. I recommend at
2263 least 50,000 usec to be safe. The alternative is to hope
2264 that one of the retries will be successful but note that
2265 the DHCP timeout and retry process takes a longer than
2268 - Link-local IP address negotiation:
2269 Negotiate with other link-local clients on the local network
2270 for an address that doesn't require explicit configuration.
2271 This is especially useful if a DHCP server cannot be guaranteed
2272 to exist in all environments that the device must operate.
2274 See doc/README.link-local for more information.
2277 CONFIG_CDP_DEVICE_ID
2279 The device id used in CDP trigger frames.
2281 CONFIG_CDP_DEVICE_ID_PREFIX
2283 A two character string which is prefixed to the MAC address
2288 A printf format string which contains the ascii name of
2289 the port. Normally is set to "eth%d" which sets
2290 eth0 for the first Ethernet, eth1 for the second etc.
2292 CONFIG_CDP_CAPABILITIES
2294 A 32bit integer which indicates the device capabilities;
2295 0x00000010 for a normal host which does not forwards.
2299 An ascii string containing the version of the software.
2303 An ascii string containing the name of the platform.
2307 A 32bit integer sent on the trigger.
2309 CONFIG_CDP_POWER_CONSUMPTION
2311 A 16bit integer containing the power consumption of the
2312 device in .1 of milliwatts.
2314 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2316 A byte containing the id of the VLAN.
2318 - Status LED: CONFIG_STATUS_LED
2320 Several configurations allow to display the current
2321 status using a LED. For instance, the LED will blink
2322 fast while running U-Boot code, stop blinking as
2323 soon as a reply to a BOOTP request was received, and
2324 start blinking slow once the Linux kernel is running
2325 (supported by a status LED driver in the Linux
2326 kernel). Defining CONFIG_STATUS_LED enables this
2332 The status LED can be connected to a GPIO pin.
2333 In such cases, the gpio_led driver can be used as a
2334 status LED backend implementation. Define CONFIG_GPIO_LED
2335 to include the gpio_led driver in the U-Boot binary.
2337 CONFIG_GPIO_LED_INVERTED_TABLE
2338 Some GPIO connected LEDs may have inverted polarity in which
2339 case the GPIO high value corresponds to LED off state and
2340 GPIO low value corresponds to LED on state.
2341 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2342 with a list of GPIO LEDs that have inverted polarity.
2344 - CAN Support: CONFIG_CAN_DRIVER
2346 Defining CONFIG_CAN_DRIVER enables CAN driver support
2347 on those systems that support this (optional)
2348 feature, like the TQM8xxL modules.
2350 - I2C Support: CONFIG_SYS_I2C
2352 This enable the NEW i2c subsystem, and will allow you to use
2353 i2c commands at the u-boot command line (as long as you set
2354 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2355 based realtime clock chips or other i2c devices. See
2356 common/cmd_i2c.c for a description of the command line
2359 ported i2c driver to the new framework:
2360 - drivers/i2c/soft_i2c.c:
2361 - activate first bus with CONFIG_SYS_I2C_SOFT define
2362 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2363 for defining speed and slave address
2364 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2365 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2366 for defining speed and slave address
2367 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2368 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2369 for defining speed and slave address
2370 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2371 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2372 for defining speed and slave address
2374 - drivers/i2c/fsl_i2c.c:
2375 - activate i2c driver with CONFIG_SYS_I2C_FSL
2376 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2377 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2378 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2380 - If your board supports a second fsl i2c bus, define
2381 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2382 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2383 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2386 - drivers/i2c/tegra_i2c.c:
2387 - activate this driver with CONFIG_SYS_I2C_TEGRA
2388 - This driver adds 4 i2c buses with a fix speed from
2389 100000 and the slave addr 0!
2391 - drivers/i2c/ppc4xx_i2c.c
2392 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2393 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2394 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2396 - drivers/i2c/i2c_mxc.c
2397 - activate this driver with CONFIG_SYS_I2C_MXC
2398 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2399 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2400 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2401 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2402 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2403 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2404 If those defines are not set, default value is 100000
2405 for speed, and 0 for slave.
2407 - drivers/i2c/rcar_i2c.c:
2408 - activate this driver with CONFIG_SYS_I2C_RCAR
2409 - This driver adds 4 i2c buses
2411 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2412 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2413 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2414 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2415 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2416 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2417 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2418 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2419 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2421 - drivers/i2c/sh_i2c.c:
2422 - activate this driver with CONFIG_SYS_I2C_SH
2423 - This driver adds from 2 to 5 i2c buses
2425 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2426 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2427 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2428 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2429 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2430 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2431 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2432 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2433 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2434 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2435 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2436 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2437 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2439 - drivers/i2c/omap24xx_i2c.c
2440 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2441 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2442 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2443 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2444 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2445 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2446 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2447 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2448 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2449 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2450 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2452 - drivers/i2c/zynq_i2c.c
2453 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2454 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2455 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2457 - drivers/i2c/s3c24x0_i2c.c:
2458 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2459 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2460 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2461 with a fix speed from 100000 and the slave addr 0!
2463 - drivers/i2c/ihs_i2c.c
2464 - activate this driver with CONFIG_SYS_I2C_IHS
2465 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2466 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2467 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2468 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2469 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2470 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2471 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2472 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2473 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2474 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2475 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2476 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2480 CONFIG_SYS_NUM_I2C_BUSES
2481 Hold the number of i2c buses you want to use. If you
2482 don't use/have i2c muxes on your i2c bus, this
2483 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2486 CONFIG_SYS_I2C_DIRECT_BUS
2487 define this, if you don't use i2c muxes on your hardware.
2488 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2491 CONFIG_SYS_I2C_MAX_HOPS
2492 define how many muxes are maximal consecutively connected
2493 on one i2c bus. If you not use i2c muxes, omit this
2496 CONFIG_SYS_I2C_BUSES
2497 hold a list of buses you want to use, only used if
2498 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2499 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2500 CONFIG_SYS_NUM_I2C_BUSES = 9:
2502 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2503 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2504 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2505 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2506 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2507 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2508 {1, {I2C_NULL_HOP}}, \
2509 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2510 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2514 bus 0 on adapter 0 without a mux
2515 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2516 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2517 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2518 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2519 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2520 bus 6 on adapter 1 without a mux
2521 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2522 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2524 If you do not have i2c muxes on your board, omit this define.
2526 - Legacy I2C Support: CONFIG_HARD_I2C
2528 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2529 provides the following compelling advantages:
2531 - more than one i2c adapter is usable
2532 - approved multibus support
2533 - better i2c mux support
2535 ** Please consider updating your I2C driver now. **
2537 These enable legacy I2C serial bus commands. Defining
2538 CONFIG_HARD_I2C will include the appropriate I2C driver
2539 for the selected CPU.
2541 This will allow you to use i2c commands at the u-boot
2542 command line (as long as you set CONFIG_CMD_I2C in
2543 CONFIG_COMMANDS) and communicate with i2c based realtime
2544 clock chips. See common/cmd_i2c.c for a description of the
2545 command line interface.
2547 CONFIG_HARD_I2C selects a hardware I2C controller.
2549 There are several other quantities that must also be
2550 defined when you define CONFIG_HARD_I2C.
2552 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2553 to be the frequency (in Hz) at which you wish your i2c bus
2554 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2555 the CPU's i2c node address).
2557 Now, the u-boot i2c code for the mpc8xx
2558 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2559 and so its address should therefore be cleared to 0 (See,
2560 eg, MPC823e User's Manual p.16-473). So, set
2561 CONFIG_SYS_I2C_SLAVE to 0.
2563 CONFIG_SYS_I2C_INIT_MPC5XXX
2565 When a board is reset during an i2c bus transfer
2566 chips might think that the current transfer is still
2567 in progress. Reset the slave devices by sending start
2568 commands until the slave device responds.
2570 That's all that's required for CONFIG_HARD_I2C.
2572 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2573 then the following macros need to be defined (examples are
2574 from include/configs/lwmon.h):
2578 (Optional). Any commands necessary to enable the I2C
2579 controller or configure ports.
2581 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2585 (Only for MPC8260 CPU). The I/O port to use (the code
2586 assumes both bits are on the same port). Valid values
2587 are 0..3 for ports A..D.
2591 The code necessary to make the I2C data line active
2592 (driven). If the data line is open collector, this
2595 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2599 The code necessary to make the I2C data line tri-stated
2600 (inactive). If the data line is open collector, this
2603 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2607 Code that returns true if the I2C data line is high,
2610 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2614 If <bit> is true, sets the I2C data line high. If it
2615 is false, it clears it (low).
2617 eg: #define I2C_SDA(bit) \
2618 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2619 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2623 If <bit> is true, sets the I2C clock line high. If it
2624 is false, it clears it (low).
2626 eg: #define I2C_SCL(bit) \
2627 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2628 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2632 This delay is invoked four times per clock cycle so this
2633 controls the rate of data transfer. The data rate thus
2634 is 1 / (I2C_DELAY * 4). Often defined to be something
2637 #define I2C_DELAY udelay(2)
2639 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2641 If your arch supports the generic GPIO framework (asm/gpio.h),
2642 then you may alternatively define the two GPIOs that are to be
2643 used as SCL / SDA. Any of the previous I2C_xxx macros will
2644 have GPIO-based defaults assigned to them as appropriate.
2646 You should define these to the GPIO value as given directly to
2647 the generic GPIO functions.
2649 CONFIG_SYS_I2C_INIT_BOARD
2651 When a board is reset during an i2c bus transfer
2652 chips might think that the current transfer is still
2653 in progress. On some boards it is possible to access
2654 the i2c SCLK line directly, either by using the
2655 processor pin as a GPIO or by having a second pin
2656 connected to the bus. If this option is defined a
2657 custom i2c_init_board() routine in boards/xxx/board.c
2658 is run early in the boot sequence.
2660 CONFIG_SYS_I2C_BOARD_LATE_INIT
2662 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2663 defined a custom i2c_board_late_init() routine in
2664 boards/xxx/board.c is run AFTER the operations in i2c_init()
2665 is completed. This callpoint can be used to unreset i2c bus
2666 using CPU i2c controller register accesses for CPUs whose i2c
2667 controller provide such a method. It is called at the end of
2668 i2c_init() to allow i2c_init operations to setup the i2c bus
2669 controller on the CPU (e.g. setting bus speed & slave address).
2671 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2673 This option enables configuration of bi_iic_fast[] flags
2674 in u-boot bd_info structure based on u-boot environment
2675 variable "i2cfast". (see also i2cfast)
2677 CONFIG_I2C_MULTI_BUS
2679 This option allows the use of multiple I2C buses, each of which
2680 must have a controller. At any point in time, only one bus is
2681 active. To switch to a different bus, use the 'i2c dev' command.
2682 Note that bus numbering is zero-based.
2684 CONFIG_SYS_I2C_NOPROBES
2686 This option specifies a list of I2C devices that will be skipped
2687 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2688 is set, specify a list of bus-device pairs. Otherwise, specify
2689 a 1D array of device addresses
2692 #undef CONFIG_I2C_MULTI_BUS
2693 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2695 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2697 #define CONFIG_I2C_MULTI_BUS
2698 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2700 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2702 CONFIG_SYS_SPD_BUS_NUM
2704 If defined, then this indicates the I2C bus number for DDR SPD.
2705 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2707 CONFIG_SYS_RTC_BUS_NUM
2709 If defined, then this indicates the I2C bus number for the RTC.
2710 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2712 CONFIG_SYS_DTT_BUS_NUM
2714 If defined, then this indicates the I2C bus number for the DTT.
2715 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2717 CONFIG_SYS_I2C_DTT_ADDR:
2719 If defined, specifies the I2C address of the DTT device.
2720 If not defined, then U-Boot uses predefined value for
2721 specified DTT device.
2723 CONFIG_SOFT_I2C_READ_REPEATED_START
2725 defining this will force the i2c_read() function in
2726 the soft_i2c driver to perform an I2C repeated start
2727 between writing the address pointer and reading the
2728 data. If this define is omitted the default behaviour
2729 of doing a stop-start sequence will be used. Most I2C
2730 devices can use either method, but some require one or
2733 - SPI Support: CONFIG_SPI
2735 Enables SPI driver (so far only tested with
2736 SPI EEPROM, also an instance works with Crystal A/D and
2737 D/As on the SACSng board)
2741 Enables the driver for SPI controller on SuperH. Currently
2742 only SH7757 is supported.
2746 Enables extended (16-bit) SPI EEPROM addressing.
2747 (symmetrical to CONFIG_I2C_X)
2751 Enables a software (bit-bang) SPI driver rather than
2752 using hardware support. This is a general purpose
2753 driver that only requires three general I/O port pins
2754 (two outputs, one input) to function. If this is
2755 defined, the board configuration must define several
2756 SPI configuration items (port pins to use, etc). For
2757 an example, see include/configs/sacsng.h.
2761 Enables a hardware SPI driver for general-purpose reads
2762 and writes. As with CONFIG_SOFT_SPI, the board configuration
2763 must define a list of chip-select function pointers.
2764 Currently supported on some MPC8xxx processors. For an
2765 example, see include/configs/mpc8349emds.h.
2769 Enables the driver for the SPI controllers on i.MX and MXC
2770 SoCs. Currently i.MX31/35/51 are supported.
2772 CONFIG_SYS_SPI_MXC_WAIT
2773 Timeout for waiting until spi transfer completed.
2774 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2776 - FPGA Support: CONFIG_FPGA
2778 Enables FPGA subsystem.
2780 CONFIG_FPGA_<vendor>
2782 Enables support for specific chip vendors.
2785 CONFIG_FPGA_<family>
2787 Enables support for FPGA family.
2788 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2792 Specify the number of FPGA devices to support.
2794 CONFIG_CMD_FPGA_LOADMK
2796 Enable support for fpga loadmk command
2798 CONFIG_CMD_FPGA_LOADP
2800 Enable support for fpga loadp command - load partial bitstream
2802 CONFIG_CMD_FPGA_LOADBP
2804 Enable support for fpga loadbp command - load partial bitstream
2807 CONFIG_SYS_FPGA_PROG_FEEDBACK
2809 Enable printing of hash marks during FPGA configuration.
2811 CONFIG_SYS_FPGA_CHECK_BUSY
2813 Enable checks on FPGA configuration interface busy
2814 status by the configuration function. This option
2815 will require a board or device specific function to
2820 If defined, a function that provides delays in the FPGA
2821 configuration driver.
2823 CONFIG_SYS_FPGA_CHECK_CTRLC
2824 Allow Control-C to interrupt FPGA configuration
2826 CONFIG_SYS_FPGA_CHECK_ERROR
2828 Check for configuration errors during FPGA bitfile
2829 loading. For example, abort during Virtex II
2830 configuration if the INIT_B line goes low (which
2831 indicated a CRC error).
2833 CONFIG_SYS_FPGA_WAIT_INIT
2835 Maximum time to wait for the INIT_B line to de-assert
2836 after PROB_B has been de-asserted during a Virtex II
2837 FPGA configuration sequence. The default time is 500
2840 CONFIG_SYS_FPGA_WAIT_BUSY
2842 Maximum time to wait for BUSY to de-assert during
2843 Virtex II FPGA configuration. The default is 5 ms.
2845 CONFIG_SYS_FPGA_WAIT_CONFIG
2847 Time to wait after FPGA configuration. The default is
2850 - Configuration Management:
2853 Some SoCs need special image types (e.g. U-Boot binary
2854 with a special header) as build targets. By defining
2855 CONFIG_BUILD_TARGET in the SoC / board header, this
2856 special image will be automatically built upon calling
2861 If defined, this string will be added to the U-Boot
2862 version information (U_BOOT_VERSION)
2864 - Vendor Parameter Protection:
2866 U-Boot considers the values of the environment
2867 variables "serial#" (Board Serial Number) and
2868 "ethaddr" (Ethernet Address) to be parameters that
2869 are set once by the board vendor / manufacturer, and
2870 protects these variables from casual modification by
2871 the user. Once set, these variables are read-only,
2872 and write or delete attempts are rejected. You can
2873 change this behaviour:
2875 If CONFIG_ENV_OVERWRITE is #defined in your config
2876 file, the write protection for vendor parameters is
2877 completely disabled. Anybody can change or delete
2880 Alternatively, if you #define _both_ CONFIG_ETHADDR
2881 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2882 Ethernet address is installed in the environment,
2883 which can be changed exactly ONCE by the user. [The
2884 serial# is unaffected by this, i. e. it remains
2887 The same can be accomplished in a more flexible way
2888 for any variable by configuring the type of access
2889 to allow for those variables in the ".flags" variable
2890 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2895 Define this variable to enable the reservation of
2896 "protected RAM", i. e. RAM which is not overwritten
2897 by U-Boot. Define CONFIG_PRAM to hold the number of
2898 kB you want to reserve for pRAM. You can overwrite
2899 this default value by defining an environment
2900 variable "pram" to the number of kB you want to
2901 reserve. Note that the board info structure will
2902 still show the full amount of RAM. If pRAM is
2903 reserved, a new environment variable "mem" will
2904 automatically be defined to hold the amount of
2905 remaining RAM in a form that can be passed as boot
2906 argument to Linux, for instance like that:
2908 setenv bootargs ... mem=\${mem}
2911 This way you can tell Linux not to use this memory,
2912 either, which results in a memory region that will
2913 not be affected by reboots.
2915 *WARNING* If your board configuration uses automatic
2916 detection of the RAM size, you must make sure that
2917 this memory test is non-destructive. So far, the
2918 following board configurations are known to be
2921 IVMS8, IVML24, SPD8xx, TQM8xxL,
2922 HERMES, IP860, RPXlite, LWMON,
2925 - Access to physical memory region (> 4GB)
2926 Some basic support is provided for operations on memory not
2927 normally accessible to U-Boot - e.g. some architectures
2928 support access to more than 4GB of memory on 32-bit
2929 machines using physical address extension or similar.
2930 Define CONFIG_PHYSMEM to access this basic support, which
2931 currently only supports clearing the memory.
2936 Define this variable to stop the system in case of a
2937 fatal error, so that you have to reset it manually.
2938 This is probably NOT a good idea for an embedded
2939 system where you want the system to reboot
2940 automatically as fast as possible, but it may be
2941 useful during development since you can try to debug
2942 the conditions that lead to the situation.
2944 CONFIG_NET_RETRY_COUNT
2946 This variable defines the number of retries for
2947 network operations like ARP, RARP, TFTP, or BOOTP
2948 before giving up the operation. If not defined, a
2949 default value of 5 is used.
2953 Timeout waiting for an ARP reply in milliseconds.
2957 Timeout in milliseconds used in NFS protocol.
2958 If you encounter "ERROR: Cannot umount" in nfs command,
2959 try longer timeout such as
2960 #define CONFIG_NFS_TIMEOUT 10000UL
2962 - Command Interpreter:
2963 CONFIG_AUTO_COMPLETE
2965 Enable auto completion of commands using TAB.
2967 CONFIG_SYS_PROMPT_HUSH_PS2
2969 This defines the secondary prompt string, which is
2970 printed when the command interpreter needs more input
2971 to complete a command. Usually "> ".
2975 In the current implementation, the local variables
2976 space and global environment variables space are
2977 separated. Local variables are those you define by
2978 simply typing `name=value'. To access a local
2979 variable later on, you have write `$name' or
2980 `${name}'; to execute the contents of a variable
2981 directly type `$name' at the command prompt.
2983 Global environment variables are those you use
2984 setenv/printenv to work with. To run a command stored
2985 in such a variable, you need to use the run command,
2986 and you must not use the '$' sign to access them.
2988 To store commands and special characters in a
2989 variable, please use double quotation marks
2990 surrounding the whole text of the variable, instead
2991 of the backslashes before semicolons and special
2994 - Command Line Editing and History:
2995 CONFIG_CMDLINE_EDITING
2997 Enable editing and History functions for interactive
2998 command line input operations
3000 - Default Environment:
3001 CONFIG_EXTRA_ENV_SETTINGS
3003 Define this to contain any number of null terminated
3004 strings (variable = value pairs) that will be part of
3005 the default environment compiled into the boot image.
3007 For example, place something like this in your
3008 board's config file:
3010 #define CONFIG_EXTRA_ENV_SETTINGS \
3014 Warning: This method is based on knowledge about the
3015 internal format how the environment is stored by the
3016 U-Boot code. This is NOT an official, exported
3017 interface! Although it is unlikely that this format
3018 will change soon, there is no guarantee either.
3019 You better know what you are doing here.
3021 Note: overly (ab)use of the default environment is
3022 discouraged. Make sure to check other ways to preset
3023 the environment like the "source" command or the
3026 CONFIG_ENV_VARS_UBOOT_CONFIG
3028 Define this in order to add variables describing the
3029 U-Boot build configuration to the default environment.
3030 These will be named arch, cpu, board, vendor, and soc.
3032 Enabling this option will cause the following to be defined:
3040 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
3042 Define this in order to add variables describing certain
3043 run-time determined information about the hardware to the
3044 environment. These will be named board_name, board_rev.
3046 CONFIG_DELAY_ENVIRONMENT
3048 Normally the environment is loaded when the board is
3049 initialised so that it is available to U-Boot. This inhibits
3050 that so that the environment is not available until
3051 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
3052 this is instead controlled by the value of
3053 /config/load-environment.
3055 - DataFlash Support:
3056 CONFIG_HAS_DATAFLASH
3058 Defining this option enables DataFlash features and
3059 allows to read/write in Dataflash via the standard
3062 - Serial Flash support
3065 Defining this option enables SPI flash commands
3066 'sf probe/read/write/erase/update'.
3068 Usage requires an initial 'probe' to define the serial
3069 flash parameters, followed by read/write/erase/update
3072 The following defaults may be provided by the platform
3073 to handle the common case when only a single serial
3074 flash is present on the system.
3076 CONFIG_SF_DEFAULT_BUS Bus identifier
3077 CONFIG_SF_DEFAULT_CS Chip-select
3078 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3079 CONFIG_SF_DEFAULT_SPEED in Hz
3083 Define this option to include a destructive SPI flash
3086 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
3088 Define this option to use the Bank addr/Extended addr
3089 support on SPI flashes which has size > 16Mbytes.
3091 CONFIG_SF_DUAL_FLASH Dual flash memories
3093 Define this option to use dual flash support where two flash
3094 memories can be connected with a given cs line.
3095 Currently Xilinx Zynq qspi supports these type of connections.
3097 CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
3098 enable the W#/Vpp signal to disable writing to the status
3099 register on ST MICRON flashes like the N25Q128.
3100 The status register write enable/disable bit, combined with
3101 the W#/VPP signal provides hardware data protection for the
3102 device as follows: When the enable/disable bit is set to 1,
3103 and the W#/VPP signal is driven LOW, the status register
3104 nonvolatile bits become read-only and the WRITE STATUS REGISTER
3105 operation will not execute. The only way to exit this
3106 hardware-protected mode is to drive W#/VPP HIGH.
3108 - SystemACE Support:
3111 Adding this option adds support for Xilinx SystemACE
3112 chips attached via some sort of local bus. The address
3113 of the chip must also be defined in the
3114 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3116 #define CONFIG_SYSTEMACE
3117 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3119 When SystemACE support is added, the "ace" device type
3120 becomes available to the fat commands, i.e. fatls.
3122 - TFTP Fixed UDP Port:
3125 If this is defined, the environment variable tftpsrcp
3126 is used to supply the TFTP UDP source port value.
3127 If tftpsrcp isn't defined, the normal pseudo-random port
3128 number generator is used.
3130 Also, the environment variable tftpdstp is used to supply
3131 the TFTP UDP destination port value. If tftpdstp isn't
3132 defined, the normal port 69 is used.
3134 The purpose for tftpsrcp is to allow a TFTP server to
3135 blindly start the TFTP transfer using the pre-configured
3136 target IP address and UDP port. This has the effect of
3137 "punching through" the (Windows XP) firewall, allowing
3138 the remainder of the TFTP transfer to proceed normally.
3139 A better solution is to properly configure the firewall,
3140 but sometimes that is not allowed.
3145 This enables a generic 'hash' command which can produce
3146 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3150 Enable the hash verify command (hash -v). This adds to code
3153 CONFIG_SHA1 - support SHA1 hashing
3154 CONFIG_SHA256 - support SHA256 hashing
3156 Note: There is also a sha1sum command, which should perhaps
3157 be deprecated in favour of 'hash sha1'.
3159 - Freescale i.MX specific commands:
3160 CONFIG_CMD_HDMIDETECT
3161 This enables 'hdmidet' command which returns true if an
3162 HDMI monitor is detected. This command is i.MX 6 specific.
3165 This enables the 'bmode' (bootmode) command for forcing
3166 a boot from specific media.
3168 This is useful for forcing the ROM's usb downloader to
3169 activate upon a watchdog reset which is nice when iterating
3170 on U-Boot. Using the reset button or running bmode normal
3171 will set it back to normal. This command currently
3172 supports i.MX53 and i.MX6.
3177 This enables the RSA algorithm used for FIT image verification
3178 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3180 The signing part is build into mkimage regardless of this
3183 - bootcount support:
3184 CONFIG_BOOTCOUNT_LIMIT
3186 This enables the bootcounter support, see:
3187 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3190 enable special bootcounter support on at91sam9xe based boards.
3192 enable special bootcounter support on blackfin based boards.
3194 enable special bootcounter support on da850 based boards.
3195 CONFIG_BOOTCOUNT_RAM
3196 enable support for the bootcounter in RAM
3197 CONFIG_BOOTCOUNT_I2C
3198 enable support for the bootcounter on an i2c (like RTC) device.
3199 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3200 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3202 CONFIG_BOOTCOUNT_ALEN = address len
3204 - Show boot progress:
3205 CONFIG_SHOW_BOOT_PROGRESS
3207 Defining this option allows to add some board-
3208 specific code (calling a user-provided function
3209 "show_boot_progress(int)") that enables you to show
3210 the system's boot progress on some display (for
3211 example, some LED's) on your board. At the moment,
3212 the following checkpoints are implemented:
3214 - Detailed boot stage timing
3216 Define this option to get detailed timing of each stage
3217 of the boot process.
3219 CONFIG_BOOTSTAGE_USER_COUNT
3220 This is the number of available user bootstage records.
3221 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3222 a new ID will be allocated from this stash. If you exceed
3223 the limit, recording will stop.
3225 CONFIG_BOOTSTAGE_REPORT
3226 Define this to print a report before boot, similar to this:
3228 Timer summary in microseconds:
3231 3,575,678 3,575,678 board_init_f start
3232 3,575,695 17 arch_cpu_init A9
3233 3,575,777 82 arch_cpu_init done
3234 3,659,598 83,821 board_init_r start
3235 3,910,375 250,777 main_loop
3236 29,916,167 26,005,792 bootm_start
3237 30,361,327 445,160 start_kernel
3239 CONFIG_CMD_BOOTSTAGE
3240 Add a 'bootstage' command which supports printing a report
3241 and un/stashing of bootstage data.
3243 CONFIG_BOOTSTAGE_FDT
3244 Stash the bootstage information in the FDT. A root 'bootstage'
3245 node is created with each bootstage id as a child. Each child
3246 has a 'name' property and either 'mark' containing the
3247 mark time in microsecond, or 'accum' containing the
3248 accumulated time for that bootstage id in microseconds.
3253 name = "board_init_f";
3262 Code in the Linux kernel can find this in /proc/devicetree.
3264 Legacy uImage format:
3267 1 common/cmd_bootm.c before attempting to boot an image
3268 -1 common/cmd_bootm.c Image header has bad magic number
3269 2 common/cmd_bootm.c Image header has correct magic number
3270 -2 common/cmd_bootm.c Image header has bad checksum
3271 3 common/cmd_bootm.c Image header has correct checksum
3272 -3 common/cmd_bootm.c Image data has bad checksum
3273 4 common/cmd_bootm.c Image data has correct checksum
3274 -4 common/cmd_bootm.c Image is for unsupported architecture
3275 5 common/cmd_bootm.c Architecture check OK
3276 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3277 6 common/cmd_bootm.c Image Type check OK
3278 -6 common/cmd_bootm.c gunzip uncompression error
3279 -7 common/cmd_bootm.c Unimplemented compression type
3280 7 common/cmd_bootm.c Uncompression OK
3281 8 common/cmd_bootm.c No uncompress/copy overwrite error
3282 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3284 9 common/image.c Start initial ramdisk verification
3285 -10 common/image.c Ramdisk header has bad magic number
3286 -11 common/image.c Ramdisk header has bad checksum
3287 10 common/image.c Ramdisk header is OK
3288 -12 common/image.c Ramdisk data has bad checksum
3289 11 common/image.c Ramdisk data has correct checksum
3290 12 common/image.c Ramdisk verification complete, start loading
3291 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3292 13 common/image.c Start multifile image verification
3293 14 common/image.c No initial ramdisk, no multifile, continue.
3295 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3297 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3298 -31 post/post.c POST test failed, detected by post_output_backlog()
3299 -32 post/post.c POST test failed, detected by post_run_single()
3301 34 common/cmd_doc.c before loading a Image from a DOC device
3302 -35 common/cmd_doc.c Bad usage of "doc" command
3303 35 common/cmd_doc.c correct usage of "doc" command
3304 -36 common/cmd_doc.c No boot device
3305 36 common/cmd_doc.c correct boot device
3306 -37 common/cmd_doc.c Unknown Chip ID on boot device
3307 37 common/cmd_doc.c correct chip ID found, device available
3308 -38 common/cmd_doc.c Read Error on boot device
3309 38 common/cmd_doc.c reading Image header from DOC device OK
3310 -39 common/cmd_doc.c Image header has bad magic number
3311 39 common/cmd_doc.c Image header has correct magic number
3312 -40 common/cmd_doc.c Error reading Image from DOC device
3313 40 common/cmd_doc.c Image header has correct magic number
3314 41 common/cmd_ide.c before loading a Image from a IDE device
3315 -42 common/cmd_ide.c Bad usage of "ide" command
3316 42 common/cmd_ide.c correct usage of "ide" command
3317 -43 common/cmd_ide.c No boot device
3318 43 common/cmd_ide.c boot device found
3319 -44 common/cmd_ide.c Device not available
3320 44 common/cmd_ide.c Device available
3321 -45 common/cmd_ide.c wrong partition selected
3322 45 common/cmd_ide.c partition selected
3323 -46 common/cmd_ide.c Unknown partition table
3324 46 common/cmd_ide.c valid partition table found
3325 -47 common/cmd_ide.c Invalid partition type
3326 47 common/cmd_ide.c correct partition type
3327 -48 common/cmd_ide.c Error reading Image Header on boot device
3328 48 common/cmd_ide.c reading Image Header from IDE device OK
3329 -49 common/cmd_ide.c Image header has bad magic number
3330 49 common/cmd_ide.c Image header has correct magic number
3331 -50 common/cmd_ide.c Image header has bad checksum
3332 50 common/cmd_ide.c Image header has correct checksum
3333 -51 common/cmd_ide.c Error reading Image from IDE device
3334 51 common/cmd_ide.c reading Image from IDE device OK
3335 52 common/cmd_nand.c before loading a Image from a NAND device
3336 -53 common/cmd_nand.c Bad usage of "nand" command
3337 53 common/cmd_nand.c correct usage of "nand" command
3338 -54 common/cmd_nand.c No boot device
3339 54 common/cmd_nand.c boot device found
3340 -55 common/cmd_nand.c Unknown Chip ID on boot device
3341 55 common/cmd_nand.c correct chip ID found, device available
3342 -56 common/cmd_nand.c Error reading Image Header on boot device
3343 56 common/cmd_nand.c reading Image Header from NAND device OK
3344 -57 common/cmd_nand.c Image header has bad magic number
3345 57 common/cmd_nand.c Image header has correct magic number
3346 -58 common/cmd_nand.c Error reading Image from NAND device
3347 58 common/cmd_nand.c reading Image from NAND device OK
3349 -60 common/env_common.c Environment has a bad CRC, using default
3351 64 net/eth.c starting with Ethernet configuration.
3352 -64 net/eth.c no Ethernet found.
3353 65 net/eth.c Ethernet found.
3355 -80 common/cmd_net.c usage wrong
3356 80 common/cmd_net.c before calling NetLoop()
3357 -81 common/cmd_net.c some error in NetLoop() occurred
3358 81 common/cmd_net.c NetLoop() back without error
3359 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3360 82 common/cmd_net.c trying automatic boot
3361 83 common/cmd_net.c running "source" command
3362 -83 common/cmd_net.c some error in automatic boot or "source" command
3363 84 common/cmd_net.c end without errors
3368 100 common/cmd_bootm.c Kernel FIT Image has correct format
3369 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3370 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3371 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3372 102 common/cmd_bootm.c Kernel unit name specified
3373 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3374 103 common/cmd_bootm.c Found configuration node
3375 104 common/cmd_bootm.c Got kernel subimage node offset
3376 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3377 105 common/cmd_bootm.c Kernel subimage hash verification OK
3378 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3379 106 common/cmd_bootm.c Architecture check OK
3380 -106 common/cmd_bootm.c Kernel subimage has wrong type
3381 107 common/cmd_bootm.c Kernel subimage type OK
3382 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3383 108 common/cmd_bootm.c Got kernel subimage data/size
3384 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3385 -109 common/cmd_bootm.c Can't get kernel subimage type
3386 -110 common/cmd_bootm.c Can't get kernel subimage comp
3387 -111 common/cmd_bootm.c Can't get kernel subimage os
3388 -112 common/cmd_bootm.c Can't get kernel subimage load address
3389 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3391 120 common/image.c Start initial ramdisk verification
3392 -120 common/image.c Ramdisk FIT image has incorrect format
3393 121 common/image.c Ramdisk FIT image has correct format
3394 122 common/image.c No ramdisk subimage unit name, using configuration
3395 -122 common/image.c Can't get configuration for ramdisk subimage
3396 123 common/image.c Ramdisk unit name specified
3397 -124 common/image.c Can't get ramdisk subimage node offset
3398 125 common/image.c Got ramdisk subimage node offset
3399 -125 common/image.c Ramdisk subimage hash verification failed
3400 126 common/image.c Ramdisk subimage hash verification OK
3401 -126 common/image.c Ramdisk subimage for unsupported architecture
3402 127 common/image.c Architecture check OK
3403 -127 common/image.c Can't get ramdisk subimage data/size
3404 128 common/image.c Got ramdisk subimage data/size
3405 129 common/image.c Can't get ramdisk load address
3406 -129 common/image.c Got ramdisk load address
3408 -130 common/cmd_doc.c Incorrect FIT image format
3409 131 common/cmd_doc.c FIT image format OK
3411 -140 common/cmd_ide.c Incorrect FIT image format
3412 141 common/cmd_ide.c FIT image format OK
3414 -150 common/cmd_nand.c Incorrect FIT image format
3415 151 common/cmd_nand.c FIT image format OK
3417 - legacy image format:
3418 CONFIG_IMAGE_FORMAT_LEGACY
3419 enables the legacy image format support in U-Boot.
3422 enabled if CONFIG_FIT_SIGNATURE is not defined.
3424 CONFIG_DISABLE_IMAGE_LEGACY
3425 disable the legacy image format
3427 This define is introduced, as the legacy image format is
3428 enabled per default for backward compatibility.
3430 - FIT image support:
3432 Enable support for the FIT uImage format.
3434 CONFIG_FIT_BEST_MATCH
3435 When no configuration is explicitly selected, default to the
3436 one whose fdt's compatibility field best matches that of
3437 U-Boot itself. A match is considered "best" if it matches the
3438 most specific compatibility entry of U-Boot's fdt's root node.
3439 The order of entries in the configuration's fdt is ignored.
3441 CONFIG_FIT_SIGNATURE
3442 This option enables signature verification of FIT uImages,
3443 using a hash signed and verified using RSA. See
3444 doc/uImage.FIT/signature.txt for more details.
3446 WARNING: When relying on signed FIT images with required
3447 signature check the legacy image format is default
3448 disabled. If a board need legacy image format support
3449 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3451 CONFIG_FIT_DISABLE_SHA256
3452 Supporting SHA256 hashes has quite an impact on binary size.
3453 For constrained systems sha256 hash support can be disabled
3456 - Standalone program support:
3457 CONFIG_STANDALONE_LOAD_ADDR
3459 This option defines a board specific value for the
3460 address where standalone program gets loaded, thus
3461 overwriting the architecture dependent default
3464 - Frame Buffer Address:
3467 Define CONFIG_FB_ADDR if you want to use specific
3468 address for frame buffer. This is typically the case
3469 when using a graphics controller has separate video
3470 memory. U-Boot will then place the frame buffer at
3471 the given address instead of dynamically reserving it
3472 in system RAM by calling lcd_setmem(), which grabs
3473 the memory for the frame buffer depending on the
3474 configured panel size.
3476 Please see board_init_f function.
3478 - Automatic software updates via TFTP server
3480 CONFIG_UPDATE_TFTP_CNT_MAX
3481 CONFIG_UPDATE_TFTP_MSEC_MAX
3483 These options enable and control the auto-update feature;
3484 for a more detailed description refer to doc/README.update.
3486 - MTD Support (mtdparts command, UBI support)
3489 Adds the MTD device infrastructure from the Linux kernel.
3490 Needed for mtdparts command support.
3492 CONFIG_MTD_PARTITIONS
3494 Adds the MTD partitioning infrastructure from the Linux
3495 kernel. Needed for UBI support.
3497 CONFIG_MTD_NAND_VERIFY_WRITE
3498 verify if the written data is correct reread.
3503 Adds commands for interacting with MTD partitions formatted
3504 with the UBI flash translation layer
3506 Requires also defining CONFIG_RBTREE
3508 CONFIG_UBI_SILENCE_MSG
3510 Make the verbose messages from UBI stop printing. This leaves
3511 warnings and errors enabled.
3514 CONFIG_MTD_UBI_WL_THRESHOLD
3515 This parameter defines the maximum difference between the highest
3516 erase counter value and the lowest erase counter value of eraseblocks
3517 of UBI devices. When this threshold is exceeded, UBI starts performing
3518 wear leveling by means of moving data from eraseblock with low erase
3519 counter to eraseblocks with high erase counter.
3521 The default value should be OK for SLC NAND flashes, NOR flashes and
3522 other flashes which have eraseblock life-cycle 100000 or more.
3523 However, in case of MLC NAND flashes which typically have eraseblock
3524 life-cycle less than 10000, the threshold should be lessened (e.g.,
3525 to 128 or 256, although it does not have to be power of 2).
3529 CONFIG_MTD_UBI_BEB_LIMIT
3530 This option specifies the maximum bad physical eraseblocks UBI
3531 expects on the MTD device (per 1024 eraseblocks). If the
3532 underlying flash does not admit of bad eraseblocks (e.g. NOR
3533 flash), this value is ignored.
3535 NAND datasheets often specify the minimum and maximum NVM
3536 (Number of Valid Blocks) for the flashes' endurance lifetime.
3537 The maximum expected bad eraseblocks per 1024 eraseblocks
3538 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3539 which gives 20 for most NANDs (MaxNVB is basically the total
3540 count of eraseblocks on the chip).
3542 To put it differently, if this value is 20, UBI will try to
3543 reserve about 1.9% of physical eraseblocks for bad blocks
3544 handling. And that will be 1.9% of eraseblocks on the entire
3545 NAND chip, not just the MTD partition UBI attaches. This means
3546 that if you have, say, a NAND flash chip admits maximum 40 bad
3547 eraseblocks, and it is split on two MTD partitions of the same
3548 size, UBI will reserve 40 eraseblocks when attaching a
3553 CONFIG_MTD_UBI_FASTMAP
3554 Fastmap is a mechanism which allows attaching an UBI device
3555 in nearly constant time. Instead of scanning the whole MTD device it
3556 only has to locate a checkpoint (called fastmap) on the device.
3557 The on-flash fastmap contains all information needed to attach
3558 the device. Using fastmap makes only sense on large devices where
3559 attaching by scanning takes long. UBI will not automatically install
3560 a fastmap on old images, but you can set the UBI parameter
3561 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3562 that fastmap-enabled images are still usable with UBI implementations
3563 without fastmap support. On typical flash devices the whole fastmap
3564 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3566 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3567 Set this parameter to enable fastmap automatically on images
3574 Adds commands for interacting with UBI volumes formatted as
3575 UBIFS. UBIFS is read-only in u-boot.
3577 Requires UBI support as well as CONFIG_LZO
3579 CONFIG_UBIFS_SILENCE_MSG
3581 Make the verbose messages from UBIFS stop printing. This leaves
3582 warnings and errors enabled.
3586 Enable building of SPL globally.
3589 LDSCRIPT for linking the SPL binary.
3591 CONFIG_SPL_MAX_FOOTPRINT
3592 Maximum size in memory allocated to the SPL, BSS included.
3593 When defined, the linker checks that the actual memory
3594 used by SPL from _start to __bss_end does not exceed it.
3595 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3596 must not be both defined at the same time.
3599 Maximum size of the SPL image (text, data, rodata, and
3600 linker lists sections), BSS excluded.
3601 When defined, the linker checks that the actual size does
3604 CONFIG_SPL_TEXT_BASE
3605 TEXT_BASE for linking the SPL binary.
3607 CONFIG_SPL_RELOC_TEXT_BASE
3608 Address to relocate to. If unspecified, this is equal to
3609 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3611 CONFIG_SPL_BSS_START_ADDR
3612 Link address for the BSS within the SPL binary.
3614 CONFIG_SPL_BSS_MAX_SIZE
3615 Maximum size in memory allocated to the SPL BSS.
3616 When defined, the linker checks that the actual memory used
3617 by SPL from __bss_start to __bss_end does not exceed it.
3618 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3619 must not be both defined at the same time.
3622 Adress of the start of the stack SPL will use
3624 CONFIG_SPL_RELOC_STACK
3625 Adress of the start of the stack SPL will use after
3626 relocation. If unspecified, this is equal to
3629 CONFIG_SYS_SPL_MALLOC_START
3630 Starting address of the malloc pool used in SPL.
3632 CONFIG_SYS_SPL_MALLOC_SIZE
3633 The size of the malloc pool used in SPL.
3635 CONFIG_SPL_FRAMEWORK
3636 Enable the SPL framework under common/. This framework
3637 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3638 NAND loading of the Linux Kernel.
3641 Enable booting directly to an OS from SPL.
3642 See also: doc/README.falcon
3644 CONFIG_SPL_DISPLAY_PRINT
3645 For ARM, enable an optional function to print more information
3646 about the running system.
3648 CONFIG_SPL_INIT_MINIMAL
3649 Arch init code should be built for a very small image
3651 CONFIG_SPL_LIBCOMMON_SUPPORT
3652 Support for common/libcommon.o in SPL binary
3654 CONFIG_SPL_LIBDISK_SUPPORT
3655 Support for disk/libdisk.o in SPL binary
3657 CONFIG_SPL_I2C_SUPPORT
3658 Support for drivers/i2c/libi2c.o in SPL binary
3660 CONFIG_SPL_GPIO_SUPPORT
3661 Support for drivers/gpio/libgpio.o in SPL binary
3663 CONFIG_SPL_MMC_SUPPORT
3664 Support for drivers/mmc/libmmc.o in SPL binary
3666 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3667 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3668 Address and partition on the MMC to load U-Boot from
3669 when the MMC is being used in raw mode.
3671 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3672 Partition on the MMC to load U-Boot from when the MMC is being
3675 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3676 Sector to load kernel uImage from when MMC is being
3677 used in raw mode (for Falcon mode)
3679 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3680 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3681 Sector and number of sectors to load kernel argument
3682 parameters from when MMC is being used in raw mode
3685 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3686 Partition on the MMC to load U-Boot from when the MMC is being
3689 CONFIG_SPL_FAT_SUPPORT
3690 Support for fs/fat/libfat.o in SPL binary
3692 CONFIG_SPL_EXT_SUPPORT
3693 Support for EXT filesystem in SPL binary
3695 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3696 Filename to read to load U-Boot when reading from filesystem
3698 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3699 Filename to read to load kernel uImage when reading
3700 from filesystem (for Falcon mode)
3702 CONFIG_SPL_FS_LOAD_ARGS_NAME
3703 Filename to read to load kernel argument parameters
3704 when reading from filesystem (for Falcon mode)
3706 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3707 Set this for NAND SPL on PPC mpc83xx targets, so that
3708 start.S waits for the rest of the SPL to load before
3709 continuing (the hardware starts execution after just
3710 loading the first page rather than the full 4K).
3712 CONFIG_SPL_SKIP_RELOCATE
3713 Avoid SPL relocation
3715 CONFIG_SPL_NAND_BASE
3716 Include nand_base.c in the SPL. Requires
3717 CONFIG_SPL_NAND_DRIVERS.
3719 CONFIG_SPL_NAND_DRIVERS
3720 SPL uses normal NAND drivers, not minimal drivers.
3723 Include standard software ECC in the SPL
3725 CONFIG_SPL_NAND_SIMPLE
3726 Support for NAND boot using simple NAND drivers that
3727 expose the cmd_ctrl() interface.
3729 CONFIG_SPL_MTD_SUPPORT
3730 Support for the MTD subsystem within SPL. Useful for
3731 environment on NAND support within SPL.
3733 CONFIG_SPL_NAND_RAW_ONLY
3734 Support to boot only raw u-boot.bin images. Use this only
3735 if you need to save space.
3737 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3738 Set for the SPL on PPC mpc8xxx targets, support for
3739 drivers/ddr/fsl/libddr.o in SPL binary.
3741 CONFIG_SPL_COMMON_INIT_DDR
3742 Set for common ddr init with serial presence detect in
3745 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3746 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3747 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3748 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3749 CONFIG_SYS_NAND_ECCBYTES
3750 Defines the size and behavior of the NAND that SPL uses
3753 CONFIG_SPL_NAND_BOOT
3754 Add support NAND boot
3756 CONFIG_SYS_NAND_U_BOOT_OFFS
3757 Location in NAND to read U-Boot from
3759 CONFIG_SYS_NAND_U_BOOT_DST
3760 Location in memory to load U-Boot to
3762 CONFIG_SYS_NAND_U_BOOT_SIZE
3763 Size of image to load
3765 CONFIG_SYS_NAND_U_BOOT_START
3766 Entry point in loaded image to jump to
3768 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3769 Define this if you need to first read the OOB and then the
3770 data. This is used, for example, on davinci platforms.
3772 CONFIG_SPL_OMAP3_ID_NAND
3773 Support for an OMAP3-specific set of functions to return the
3774 ID and MFR of the first attached NAND chip, if present.
3776 CONFIG_SPL_SERIAL_SUPPORT
3777 Support for drivers/serial/libserial.o in SPL binary
3779 CONFIG_SPL_SPI_FLASH_SUPPORT
3780 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3782 CONFIG_SPL_SPI_SUPPORT
3783 Support for drivers/spi/libspi.o in SPL binary
3785 CONFIG_SPL_RAM_DEVICE
3786 Support for running image already present in ram, in SPL binary
3788 CONFIG_SPL_LIBGENERIC_SUPPORT
3789 Support for lib/libgeneric.o in SPL binary
3791 CONFIG_SPL_ENV_SUPPORT
3792 Support for the environment operating in SPL binary
3794 CONFIG_SPL_NET_SUPPORT
3795 Support for the net/libnet.o in SPL binary.
3796 It conflicts with SPL env from storage medium specified by
3797 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3800 Image offset to which the SPL should be padded before appending
3801 the SPL payload. By default, this is defined as
3802 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3803 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3804 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3807 Final target image containing SPL and payload. Some SPLs
3808 use an arch-specific makefile fragment instead, for
3809 example if more than one image needs to be produced.
3811 CONFIG_FIT_SPL_PRINT
3812 Printing information about a FIT image adds quite a bit of
3813 code to SPL. So this is normally disabled in SPL. Use this
3814 option to re-enable it. This will affect the output of the
3815 bootm command when booting a FIT image.
3819 Enable building of TPL globally.
3822 Image offset to which the TPL should be padded before appending
3823 the TPL payload. By default, this is defined as
3824 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3825 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3826 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3831 [so far only for SMDK2400 boards]
3833 - Modem support enable:
3834 CONFIG_MODEM_SUPPORT
3836 - RTS/CTS Flow control enable:
3839 - Modem debug support:
3840 CONFIG_MODEM_SUPPORT_DEBUG
3842 Enables debugging stuff (char screen[1024], dbg())
3843 for modem support. Useful only with BDI2000.
3845 - Interrupt support (PPC):
3847 There are common interrupt_init() and timer_interrupt()
3848 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3849 for CPU specific initialization. interrupt_init_cpu()
3850 should set decrementer_count to appropriate value. If
3851 CPU resets decrementer automatically after interrupt
3852 (ppc4xx) it should set decrementer_count to zero.
3853 timer_interrupt() calls timer_interrupt_cpu() for CPU
3854 specific handling. If board has watchdog / status_led
3855 / other_activity_monitor it works automatically from
3856 general timer_interrupt().
3860 In the target system modem support is enabled when a
3861 specific key (key combination) is pressed during
3862 power-on. Otherwise U-Boot will boot normally
3863 (autoboot). The key_pressed() function is called from
3864 board_init(). Currently key_pressed() is a dummy
3865 function, returning 1 and thus enabling modem
3868 If there are no modem init strings in the
3869 environment, U-Boot proceed to autoboot; the
3870 previous output (banner, info printfs) will be
3873 See also: doc/README.Modem
3875 Board initialization settings:
3876 ------------------------------
3878 During Initialization u-boot calls a number of board specific functions
3879 to allow the preparation of board specific prerequisites, e.g. pin setup
3880 before drivers are initialized. To enable these callbacks the
3881 following configuration macros have to be defined. Currently this is
3882 architecture specific, so please check arch/your_architecture/lib/board.c
3883 typically in board_init_f() and board_init_r().
3885 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3886 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3887 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3888 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3890 Configuration Settings:
3891 -----------------------
3893 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3894 Optionally it can be defined to support 64-bit memory commands.
3896 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3897 undefine this when you're short of memory.
3899 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3900 width of the commands listed in the 'help' command output.
3902 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3903 prompt for user input.
3905 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3907 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3909 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3911 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3912 the application (usually a Linux kernel) when it is
3915 - CONFIG_SYS_BAUDRATE_TABLE:
3916 List of legal baudrate settings for this board.
3918 - CONFIG_SYS_CONSOLE_INFO_QUIET
3919 Suppress display of console information at boot.
3921 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3922 If the board specific function
3923 extern int overwrite_console (void);
3924 returns 1, the stdin, stderr and stdout are switched to the
3925 serial port, else the settings in the environment are used.
3927 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3928 Enable the call to overwrite_console().
3930 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3931 Enable overwrite of previous console environment settings.
3933 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3934 Begin and End addresses of the area used by the
3937 - CONFIG_SYS_ALT_MEMTEST:
3938 Enable an alternate, more extensive memory test.
3940 - CONFIG_SYS_MEMTEST_SCRATCH:
3941 Scratch address used by the alternate memory test
3942 You only need to set this if address zero isn't writeable
3944 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3945 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3946 this specified memory area will get subtracted from the top
3947 (end) of RAM and won't get "touched" at all by U-Boot. By
3948 fixing up gd->ram_size the Linux kernel should gets passed
3949 the now "corrected" memory size and won't touch it either.
3950 This should work for arch/ppc and arch/powerpc. Only Linux
3951 board ports in arch/powerpc with bootwrapper support that
3952 recalculate the memory size from the SDRAM controller setup
3953 will have to get fixed in Linux additionally.
3955 This option can be used as a workaround for the 440EPx/GRx
3956 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3959 WARNING: Please make sure that this value is a multiple of
3960 the Linux page size (normally 4k). If this is not the case,
3961 then the end address of the Linux memory will be located at a
3962 non page size aligned address and this could cause major
3965 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3966 Enable temporary baudrate change while serial download
3968 - CONFIG_SYS_SDRAM_BASE:
3969 Physical start address of SDRAM. _Must_ be 0 here.
3971 - CONFIG_SYS_MBIO_BASE:
3972 Physical start address of Motherboard I/O (if using a
3975 - CONFIG_SYS_FLASH_BASE:
3976 Physical start address of Flash memory.
3978 - CONFIG_SYS_MONITOR_BASE:
3979 Physical start address of boot monitor code (set by
3980 make config files to be same as the text base address
3981 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3982 CONFIG_SYS_FLASH_BASE when booting from flash.
3984 - CONFIG_SYS_MONITOR_LEN:
3985 Size of memory reserved for monitor code, used to
3986 determine _at_compile_time_ (!) if the environment is
3987 embedded within the U-Boot image, or in a separate
3990 - CONFIG_SYS_MALLOC_LEN:
3991 Size of DRAM reserved for malloc() use.
3993 - CONFIG_SYS_MALLOC_F_LEN
3994 Size of the malloc() pool for use before relocation. If
3995 this is defined, then a very simple malloc() implementation
3996 will become available before relocation. The address is just
3997 below the global data, and the stack is moved down to make
4000 This feature allocates regions with increasing addresses
4001 within the region. calloc() is supported, but realloc()
4002 is not available. free() is supported but does nothing.
4003 The memory will be freed (or in fact just forgotten) when
4004 U-Boot relocates itself.
4006 Pre-relocation malloc() is only supported on ARM and sandbox
4007 at present but is fairly easy to enable for other archs.
4009 - CONFIG_SYS_MALLOC_SIMPLE
4010 Provides a simple and small malloc() and calloc() for those
4011 boards which do not use the full malloc in SPL (which is
4012 enabled with CONFIG_SYS_SPL_MALLOC_START).
4014 - CONFIG_SYS_NONCACHED_MEMORY:
4015 Size of non-cached memory area. This area of memory will be
4016 typically located right below the malloc() area and mapped
4017 uncached in the MMU. This is useful for drivers that would
4018 otherwise require a lot of explicit cache maintenance. For
4019 some drivers it's also impossible to properly maintain the
4020 cache. For example if the regions that need to be flushed
4021 are not a multiple of the cache-line size, *and* padding
4022 cannot be allocated between the regions to align them (i.e.
4023 if the HW requires a contiguous array of regions, and the
4024 size of each region is not cache-aligned), then a flush of
4025 one region may result in overwriting data that hardware has
4026 written to another region in the same cache-line. This can
4027 happen for example in network drivers where descriptors for
4028 buffers are typically smaller than the CPU cache-line (e.g.
4029 16 bytes vs. 32 or 64 bytes).
4031 Non-cached memory is only supported on 32-bit ARM at present.
4033 - CONFIG_SYS_BOOTM_LEN:
4034 Normally compressed uImages are limited to an
4035 uncompressed size of 8 MBytes. If this is not enough,
4036 you can define CONFIG_SYS_BOOTM_LEN in your board config file
4037 to adjust this setting to your needs.
4039 - CONFIG_SYS_BOOTMAPSZ:
4040 Maximum size of memory mapped by the startup code of
4041 the Linux kernel; all data that must be processed by
4042 the Linux kernel (bd_info, boot arguments, FDT blob if
4043 used) must be put below this limit, unless "bootm_low"
4044 environment variable is defined and non-zero. In such case
4045 all data for the Linux kernel must be between "bootm_low"
4046 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
4047 variable "bootm_mapsize" will override the value of
4048 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
4049 then the value in "bootm_size" will be used instead.
4051 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
4052 Enable initrd_high functionality. If defined then the
4053 initrd_high feature is enabled and the bootm ramdisk subcommand
4056 - CONFIG_SYS_BOOT_GET_CMDLINE:
4057 Enables allocating and saving kernel cmdline in space between
4058 "bootm_low" and "bootm_low" + BOOTMAPSZ.
4060 - CONFIG_SYS_BOOT_GET_KBD:
4061 Enables allocating and saving a kernel copy of the bd_info in
4062 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
4064 - CONFIG_SYS_MAX_FLASH_BANKS:
4065 Max number of Flash memory banks
4067 - CONFIG_SYS_MAX_FLASH_SECT:
4068 Max number of sectors on a Flash chip
4070 - CONFIG_SYS_FLASH_ERASE_TOUT:
4071 Timeout for Flash erase operations (in ms)
4073 - CONFIG_SYS_FLASH_WRITE_TOUT:
4074 Timeout for Flash write operations (in ms)
4076 - CONFIG_SYS_FLASH_LOCK_TOUT
4077 Timeout for Flash set sector lock bit operation (in ms)
4079 - CONFIG_SYS_FLASH_UNLOCK_TOUT
4080 Timeout for Flash clear lock bits operation (in ms)
4082 - CONFIG_SYS_FLASH_PROTECTION
4083 If defined, hardware flash sectors protection is used
4084 instead of U-Boot software protection.
4086 - CONFIG_SYS_DIRECT_FLASH_TFTP:
4088 Enable TFTP transfers directly to flash memory;
4089 without this option such a download has to be
4090 performed in two steps: (1) download to RAM, and (2)
4091 copy from RAM to flash.
4093 The two-step approach is usually more reliable, since
4094 you can check if the download worked before you erase
4095 the flash, but in some situations (when system RAM is
4096 too limited to allow for a temporary copy of the
4097 downloaded image) this option may be very useful.
4099 - CONFIG_SYS_FLASH_CFI:
4100 Define if the flash driver uses extra elements in the
4101 common flash structure for storing flash geometry.
4103 - CONFIG_FLASH_CFI_DRIVER
4104 This option also enables the building of the cfi_flash driver
4105 in the drivers directory
4107 - CONFIG_FLASH_CFI_MTD
4108 This option enables the building of the cfi_mtd driver
4109 in the drivers directory. The driver exports CFI flash
4112 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
4113 Use buffered writes to flash.
4115 - CONFIG_FLASH_SPANSION_S29WS_N
4116 s29ws-n MirrorBit flash has non-standard addresses for buffered
4119 - CONFIG_SYS_FLASH_QUIET_TEST
4120 If this option is defined, the common CFI flash doesn't
4121 print it's warning upon not recognized FLASH banks. This
4122 is useful, if some of the configured banks are only
4123 optionally available.
4125 - CONFIG_FLASH_SHOW_PROGRESS
4126 If defined (must be an integer), print out countdown
4127 digits and dots. Recommended value: 45 (9..1) for 80
4128 column displays, 15 (3..1) for 40 column displays.
4130 - CONFIG_FLASH_VERIFY
4131 If defined, the content of the flash (destination) is compared
4132 against the source after the write operation. An error message
4133 will be printed when the contents are not identical.
4134 Please note that this option is useless in nearly all cases,
4135 since such flash programming errors usually are detected earlier
4136 while unprotecting/erasing/programming. Please only enable
4137 this option if you really know what you are doing.
4139 - CONFIG_SYS_RX_ETH_BUFFER:
4140 Defines the number of Ethernet receive buffers. On some
4141 Ethernet controllers it is recommended to set this value
4142 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4143 buffers can be full shortly after enabling the interface
4144 on high Ethernet traffic.
4145 Defaults to 4 if not defined.
4147 - CONFIG_ENV_MAX_ENTRIES
4149 Maximum number of entries in the hash table that is used
4150 internally to store the environment settings. The default
4151 setting is supposed to be generous and should work in most
4152 cases. This setting can be used to tune behaviour; see
4153 lib/hashtable.c for details.
4155 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4156 - CONFIG_ENV_FLAGS_LIST_STATIC
4157 Enable validation of the values given to environment variables when
4158 calling env set. Variables can be restricted to only decimal,
4159 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4160 the variables can also be restricted to IP address or MAC address.
4162 The format of the list is:
4163 type_attribute = [s|d|x|b|i|m]
4164 access_attribute = [a|r|o|c]
4165 attributes = type_attribute[access_attribute]
4166 entry = variable_name[:attributes]
4169 The type attributes are:
4170 s - String (default)
4173 b - Boolean ([1yYtT|0nNfF])
4177 The access attributes are:
4183 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4184 Define this to a list (string) to define the ".flags"
4185 environment variable in the default or embedded environment.
4187 - CONFIG_ENV_FLAGS_LIST_STATIC
4188 Define this to a list (string) to define validation that
4189 should be done if an entry is not found in the ".flags"
4190 environment variable. To override a setting in the static
4191 list, simply add an entry for the same variable name to the
4194 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4195 If defined, don't allow the -f switch to env set override variable
4198 - CONFIG_SYS_GENERIC_BOARD
4199 This selects the architecture-generic board system instead of the
4200 architecture-specific board files. It is intended to move boards
4201 to this new framework over time. Defining this will disable the
4202 arch/foo/lib/board.c file and use common/board_f.c and
4203 common/board_r.c instead. To use this option your architecture
4204 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
4205 its config.mk file). If you find problems enabling this option on
4206 your board please report the problem and send patches!
4208 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4209 This is set by OMAP boards for the max time that reset should
4210 be asserted. See doc/README.omap-reset-time for details on how
4211 the value can be calculated on a given board.
4214 If stdint.h is available with your toolchain you can define this
4215 option to enable it. You can provide option 'USE_STDINT=1' when
4216 building U-Boot to enable this.
4218 The following definitions that deal with the placement and management
4219 of environment data (variable area); in general, we support the
4220 following configurations:
4222 - CONFIG_BUILD_ENVCRC:
4224 Builds up envcrc with the target environment so that external utils
4225 may easily extract it and embed it in final U-Boot images.
4227 - CONFIG_ENV_IS_IN_FLASH:
4229 Define this if the environment is in flash memory.
4231 a) The environment occupies one whole flash sector, which is
4232 "embedded" in the text segment with the U-Boot code. This
4233 happens usually with "bottom boot sector" or "top boot
4234 sector" type flash chips, which have several smaller
4235 sectors at the start or the end. For instance, such a
4236 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4237 such a case you would place the environment in one of the
4238 4 kB sectors - with U-Boot code before and after it. With
4239 "top boot sector" type flash chips, you would put the
4240 environment in one of the last sectors, leaving a gap
4241 between U-Boot and the environment.
4243 - CONFIG_ENV_OFFSET:
4245 Offset of environment data (variable area) to the
4246 beginning of flash memory; for instance, with bottom boot
4247 type flash chips the second sector can be used: the offset
4248 for this sector is given here.
4250 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4254 This is just another way to specify the start address of
4255 the flash sector containing the environment (instead of
4258 - CONFIG_ENV_SECT_SIZE:
4260 Size of the sector containing the environment.
4263 b) Sometimes flash chips have few, equal sized, BIG sectors.
4264 In such a case you don't want to spend a whole sector for
4269 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4270 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4271 of this flash sector for the environment. This saves
4272 memory for the RAM copy of the environment.
4274 It may also save flash memory if you decide to use this
4275 when your environment is "embedded" within U-Boot code,
4276 since then the remainder of the flash sector could be used
4277 for U-Boot code. It should be pointed out that this is
4278 STRONGLY DISCOURAGED from a robustness point of view:
4279 updating the environment in flash makes it always
4280 necessary to erase the WHOLE sector. If something goes
4281 wrong before the contents has been restored from a copy in
4282 RAM, your target system will be dead.
4284 - CONFIG_ENV_ADDR_REDUND
4285 CONFIG_ENV_SIZE_REDUND
4287 These settings describe a second storage area used to hold
4288 a redundant copy of the environment data, so that there is
4289 a valid backup copy in case there is a power failure during
4290 a "saveenv" operation.
4292 BE CAREFUL! Any changes to the flash layout, and some changes to the
4293 source code will make it necessary to adapt <board>/u-boot.lds*
4297 - CONFIG_ENV_IS_IN_NVRAM:
4299 Define this if you have some non-volatile memory device
4300 (NVRAM, battery buffered SRAM) which you want to use for the
4306 These two #defines are used to determine the memory area you
4307 want to use for environment. It is assumed that this memory
4308 can just be read and written to, without any special
4311 BE CAREFUL! The first access to the environment happens quite early
4312 in U-Boot initialization (when we try to get the setting of for the
4313 console baudrate). You *MUST* have mapped your NVRAM area then, or
4316 Please note that even with NVRAM we still use a copy of the
4317 environment in RAM: we could work on NVRAM directly, but we want to
4318 keep settings there always unmodified except somebody uses "saveenv"
4319 to save the current settings.
4322 - CONFIG_ENV_IS_IN_EEPROM:
4324 Use this if you have an EEPROM or similar serial access
4325 device and a driver for it.
4327 - CONFIG_ENV_OFFSET:
4330 These two #defines specify the offset and size of the
4331 environment area within the total memory of your EEPROM.
4333 - CONFIG_SYS_I2C_EEPROM_ADDR:
4334 If defined, specified the chip address of the EEPROM device.
4335 The default address is zero.
4337 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4338 If defined, the number of bits used to address bytes in a
4339 single page in the EEPROM device. A 64 byte page, for example
4340 would require six bits.
4342 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4343 If defined, the number of milliseconds to delay between
4344 page writes. The default is zero milliseconds.
4346 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4347 The length in bytes of the EEPROM memory array address. Note
4348 that this is NOT the chip address length!
4350 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4351 EEPROM chips that implement "address overflow" are ones
4352 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4353 address and the extra bits end up in the "chip address" bit
4354 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4357 Note that we consider the length of the address field to
4358 still be one byte because the extra address bits are hidden
4359 in the chip address.
4361 - CONFIG_SYS_EEPROM_SIZE:
4362 The size in bytes of the EEPROM device.
4364 - CONFIG_ENV_EEPROM_IS_ON_I2C
4365 define this, if you have I2C and SPI activated, and your
4366 EEPROM, which holds the environment, is on the I2C bus.
4368 - CONFIG_I2C_ENV_EEPROM_BUS
4369 if you have an Environment on an EEPROM reached over
4370 I2C muxes, you can define here, how to reach this
4371 EEPROM. For example:
4373 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4375 EEPROM which holds the environment, is reached over
4376 a pca9547 i2c mux with address 0x70, channel 3.
4378 - CONFIG_ENV_IS_IN_DATAFLASH:
4380 Define this if you have a DataFlash memory device which you
4381 want to use for the environment.
4383 - CONFIG_ENV_OFFSET:
4387 These three #defines specify the offset and size of the
4388 environment area within the total memory of your DataFlash placed
4389 at the specified address.
4391 - CONFIG_ENV_IS_IN_SPI_FLASH:
4393 Define this if you have a SPI Flash memory device which you
4394 want to use for the environment.
4396 - CONFIG_ENV_OFFSET:
4399 These two #defines specify the offset and size of the
4400 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4401 aligned to an erase sector boundary.
4403 - CONFIG_ENV_SECT_SIZE:
4405 Define the SPI flash's sector size.
4407 - CONFIG_ENV_OFFSET_REDUND (optional):
4409 This setting describes a second storage area of CONFIG_ENV_SIZE
4410 size used to hold a redundant copy of the environment data, so
4411 that there is a valid backup copy in case there is a power failure
4412 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4413 aligned to an erase sector boundary.
4415 - CONFIG_ENV_SPI_BUS (optional):
4416 - CONFIG_ENV_SPI_CS (optional):
4418 Define the SPI bus and chip select. If not defined they will be 0.
4420 - CONFIG_ENV_SPI_MAX_HZ (optional):
4422 Define the SPI max work clock. If not defined then use 1MHz.
4424 - CONFIG_ENV_SPI_MODE (optional):
4426 Define the SPI work mode. If not defined then use SPI_MODE_3.
4428 - CONFIG_ENV_IS_IN_REMOTE:
4430 Define this if you have a remote memory space which you
4431 want to use for the local device's environment.
4436 These two #defines specify the address and size of the
4437 environment area within the remote memory space. The
4438 local device can get the environment from remote memory
4439 space by SRIO or PCIE links.
4441 BE CAREFUL! For some special cases, the local device can not use
4442 "saveenv" command. For example, the local device will get the
4443 environment stored in a remote NOR flash by SRIO or PCIE link,
4444 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4446 - CONFIG_ENV_IS_IN_NAND:
4448 Define this if you have a NAND device which you want to use
4449 for the environment.
4451 - CONFIG_ENV_OFFSET:
4454 These two #defines specify the offset and size of the environment
4455 area within the first NAND device. CONFIG_ENV_OFFSET must be
4456 aligned to an erase block boundary.
4458 - CONFIG_ENV_OFFSET_REDUND (optional):
4460 This setting describes a second storage area of CONFIG_ENV_SIZE
4461 size used to hold a redundant copy of the environment data, so
4462 that there is a valid backup copy in case there is a power failure
4463 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4464 aligned to an erase block boundary.
4466 - CONFIG_ENV_RANGE (optional):
4468 Specifies the length of the region in which the environment
4469 can be written. This should be a multiple of the NAND device's
4470 block size. Specifying a range with more erase blocks than
4471 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4472 the range to be avoided.
4474 - CONFIG_ENV_OFFSET_OOB (optional):
4476 Enables support for dynamically retrieving the offset of the
4477 environment from block zero's out-of-band data. The
4478 "nand env.oob" command can be used to record this offset.
4479 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4480 using CONFIG_ENV_OFFSET_OOB.
4482 - CONFIG_NAND_ENV_DST
4484 Defines address in RAM to which the nand_spl code should copy the
4485 environment. If redundant environment is used, it will be copied to
4486 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4488 - CONFIG_ENV_IS_IN_UBI:
4490 Define this if you have an UBI volume that you want to use for the
4491 environment. This has the benefit of wear-leveling the environment
4492 accesses, which is important on NAND.
4494 - CONFIG_ENV_UBI_PART:
4496 Define this to a string that is the mtd partition containing the UBI.
4498 - CONFIG_ENV_UBI_VOLUME:
4500 Define this to the name of the volume that you want to store the
4503 - CONFIG_ENV_UBI_VOLUME_REDUND:
4505 Define this to the name of another volume to store a second copy of
4506 the environment in. This will enable redundant environments in UBI.
4507 It is assumed that both volumes are in the same MTD partition.
4509 - CONFIG_UBI_SILENCE_MSG
4510 - CONFIG_UBIFS_SILENCE_MSG
4512 You will probably want to define these to avoid a really noisy system
4513 when storing the env in UBI.
4515 - CONFIG_ENV_IS_IN_FAT:
4516 Define this if you want to use the FAT file system for the environment.
4518 - FAT_ENV_INTERFACE:
4520 Define this to a string that is the name of the block device.
4522 - FAT_ENV_DEV_AND_PART:
4524 Define this to a string to specify the partition of the device. It can
4527 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4528 - "D:P": device D partition P. Error occurs if device D has no
4531 - "D" or "D:": device D partition 1 if device D has partition
4532 table, or the whole device D if has no partition
4534 - "D:auto": first partition in device D with bootable flag set.
4535 If none, first valid partition in device D. If no
4536 partition table then means device D.
4540 It's a string of the FAT file name. This file use to store the
4544 This should be defined. Otherwise it cannot save the environment file.
4546 - CONFIG_ENV_IS_IN_MMC:
4548 Define this if you have an MMC device which you want to use for the
4551 - CONFIG_SYS_MMC_ENV_DEV:
4553 Specifies which MMC device the environment is stored in.
4555 - CONFIG_SYS_MMC_ENV_PART (optional):
4557 Specifies which MMC partition the environment is stored in. If not
4558 set, defaults to partition 0, the user area. Common values might be
4559 1 (first MMC boot partition), 2 (second MMC boot partition).
4561 - CONFIG_ENV_OFFSET:
4564 These two #defines specify the offset and size of the environment
4565 area within the specified MMC device.
4567 If offset is positive (the usual case), it is treated as relative to
4568 the start of the MMC partition. If offset is negative, it is treated
4569 as relative to the end of the MMC partition. This can be useful if
4570 your board may be fitted with different MMC devices, which have
4571 different sizes for the MMC partitions, and you always want the
4572 environment placed at the very end of the partition, to leave the
4573 maximum possible space before it, to store other data.
4575 These two values are in units of bytes, but must be aligned to an
4576 MMC sector boundary.
4578 - CONFIG_ENV_OFFSET_REDUND (optional):
4580 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4581 hold a redundant copy of the environment data. This provides a
4582 valid backup copy in case the other copy is corrupted, e.g. due
4583 to a power failure during a "saveenv" operation.
4585 This value may also be positive or negative; this is handled in the
4586 same way as CONFIG_ENV_OFFSET.
4588 This value is also in units of bytes, but must also be aligned to
4589 an MMC sector boundary.
4591 - CONFIG_ENV_SIZE_REDUND (optional):
4593 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4594 set. If this value is set, it must be set to the same value as
4597 - CONFIG_SYS_SPI_INIT_OFFSET
4599 Defines offset to the initial SPI buffer area in DPRAM. The
4600 area is used at an early stage (ROM part) if the environment
4601 is configured to reside in the SPI EEPROM: We need a 520 byte
4602 scratch DPRAM area. It is used between the two initialization
4603 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4604 to be a good choice since it makes it far enough from the
4605 start of the data area as well as from the stack pointer.
4607 Please note that the environment is read-only until the monitor
4608 has been relocated to RAM and a RAM copy of the environment has been
4609 created; also, when using EEPROM you will have to use getenv_f()
4610 until then to read environment variables.
4612 The environment is protected by a CRC32 checksum. Before the monitor
4613 is relocated into RAM, as a result of a bad CRC you will be working
4614 with the compiled-in default environment - *silently*!!! [This is
4615 necessary, because the first environment variable we need is the
4616 "baudrate" setting for the console - if we have a bad CRC, we don't
4617 have any device yet where we could complain.]
4619 Note: once the monitor has been relocated, then it will complain if
4620 the default environment is used; a new CRC is computed as soon as you
4621 use the "saveenv" command to store a valid environment.
4623 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4624 Echo the inverted Ethernet link state to the fault LED.
4626 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4627 also needs to be defined.
4629 - CONFIG_SYS_FAULT_MII_ADDR:
4630 MII address of the PHY to check for the Ethernet link state.
4632 - CONFIG_NS16550_MIN_FUNCTIONS:
4633 Define this if you desire to only have use of the NS16550_init
4634 and NS16550_putc functions for the serial driver located at
4635 drivers/serial/ns16550.c. This option is useful for saving
4636 space for already greatly restricted images, including but not
4637 limited to NAND_SPL configurations.
4639 - CONFIG_DISPLAY_BOARDINFO
4640 Display information about the board that U-Boot is running on
4641 when U-Boot starts up. The board function checkboard() is called
4644 - CONFIG_DISPLAY_BOARDINFO_LATE
4645 Similar to the previous option, but display this information
4646 later, once stdio is running and output goes to the LCD, if
4649 - CONFIG_BOARD_SIZE_LIMIT:
4650 Maximum size of the U-Boot image. When defined, the
4651 build system checks that the actual size does not
4654 Low Level (hardware related) configuration options:
4655 ---------------------------------------------------
4657 - CONFIG_SYS_CACHELINE_SIZE:
4658 Cache Line Size of the CPU.
4660 - CONFIG_SYS_DEFAULT_IMMR:
4661 Default address of the IMMR after system reset.
4663 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4664 and RPXsuper) to be able to adjust the position of
4665 the IMMR register after a reset.
4667 - CONFIG_SYS_CCSRBAR_DEFAULT:
4668 Default (power-on reset) physical address of CCSR on Freescale
4671 - CONFIG_SYS_CCSRBAR:
4672 Virtual address of CCSR. On a 32-bit build, this is typically
4673 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4675 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4676 for cross-platform code that uses that macro instead.
4678 - CONFIG_SYS_CCSRBAR_PHYS:
4679 Physical address of CCSR. CCSR can be relocated to a new
4680 physical address, if desired. In this case, this macro should
4681 be set to that address. Otherwise, it should be set to the
4682 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4683 is typically relocated on 36-bit builds. It is recommended
4684 that this macro be defined via the _HIGH and _LOW macros:
4686 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4687 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4689 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4690 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4691 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4692 used in assembly code, so it must not contain typecasts or
4693 integer size suffixes (e.g. "ULL").
4695 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4696 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4697 used in assembly code, so it must not contain typecasts or
4698 integer size suffixes (e.g. "ULL").
4700 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4701 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4702 forced to a value that ensures that CCSR is not relocated.
4704 - Floppy Disk Support:
4705 CONFIG_SYS_FDC_DRIVE_NUMBER
4707 the default drive number (default value 0)
4709 CONFIG_SYS_ISA_IO_STRIDE
4711 defines the spacing between FDC chipset registers
4714 CONFIG_SYS_ISA_IO_OFFSET
4716 defines the offset of register from address. It
4717 depends on which part of the data bus is connected to
4718 the FDC chipset. (default value 0)
4720 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4721 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4724 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4725 fdc_hw_init() is called at the beginning of the FDC
4726 setup. fdc_hw_init() must be provided by the board
4727 source code. It is used to make hardware-dependent
4731 Most IDE controllers were designed to be connected with PCI
4732 interface. Only few of them were designed for AHB interface.
4733 When software is doing ATA command and data transfer to
4734 IDE devices through IDE-AHB controller, some additional
4735 registers accessing to these kind of IDE-AHB controller
4738 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4739 DO NOT CHANGE unless you know exactly what you're
4740 doing! (11-4) [MPC8xx/82xx systems only]
4742 - CONFIG_SYS_INIT_RAM_ADDR:
4744 Start address of memory area that can be used for
4745 initial data and stack; please note that this must be
4746 writable memory that is working WITHOUT special
4747 initialization, i. e. you CANNOT use normal RAM which
4748 will become available only after programming the
4749 memory controller and running certain initialization
4752 U-Boot uses the following memory types:
4753 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4754 - MPC824X: data cache
4755 - PPC4xx: data cache
4757 - CONFIG_SYS_GBL_DATA_OFFSET:
4759 Offset of the initial data structure in the memory
4760 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4761 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4762 data is located at the end of the available space
4763 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4764 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4765 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4766 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4769 On the MPC824X (or other systems that use the data
4770 cache for initial memory) the address chosen for
4771 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4772 point to an otherwise UNUSED address space between
4773 the top of RAM and the start of the PCI space.
4775 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4777 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4779 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4781 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4783 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4785 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4787 - CONFIG_SYS_OR_TIMING_SDRAM:
4790 - CONFIG_SYS_MAMR_PTA:
4791 periodic timer for refresh
4793 - CONFIG_SYS_DER: Debug Event Register (37-47)
4795 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4796 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4797 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4798 CONFIG_SYS_BR1_PRELIM:
4799 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4801 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4802 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4803 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4804 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4806 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4807 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4808 Machine Mode Register and Memory Periodic Timer
4809 Prescaler definitions (SDRAM timing)
4811 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4812 enable I2C microcode relocation patch (MPC8xx);
4813 define relocation offset in DPRAM [DSP2]
4815 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4816 enable SMC microcode relocation patch (MPC8xx);
4817 define relocation offset in DPRAM [SMC1]
4819 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4820 enable SPI microcode relocation patch (MPC8xx);
4821 define relocation offset in DPRAM [SCC4]
4823 - CONFIG_SYS_USE_OSCCLK:
4824 Use OSCM clock mode on MBX8xx board. Be careful,
4825 wrong setting might damage your board. Read
4826 doc/README.MBX before setting this variable!
4828 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4829 Offset of the bootmode word in DPRAM used by post
4830 (Power On Self Tests). This definition overrides
4831 #define'd default value in commproc.h resp.
4834 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4835 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4836 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4837 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4838 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4839 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4840 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4841 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4842 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4844 - CONFIG_PCI_DISABLE_PCIE:
4845 Disable PCI-Express on systems where it is supported but not
4848 - CONFIG_PCI_ENUM_ONLY
4849 Only scan through and get the devices on the buses.
4850 Don't do any setup work, presumably because someone or
4851 something has already done it, and we don't need to do it
4852 a second time. Useful for platforms that are pre-booted
4853 by coreboot or similar.
4855 - CONFIG_PCI_INDIRECT_BRIDGE:
4856 Enable support for indirect PCI bridges.
4859 Chip has SRIO or not
4862 Board has SRIO 1 port available
4865 Board has SRIO 2 port available
4867 - CONFIG_SRIO_PCIE_BOOT_MASTER
4868 Board can support master function for Boot from SRIO and PCIE
4870 - CONFIG_SYS_SRIOn_MEM_VIRT:
4871 Virtual Address of SRIO port 'n' memory region
4873 - CONFIG_SYS_SRIOn_MEM_PHYS:
4874 Physical Address of SRIO port 'n' memory region
4876 - CONFIG_SYS_SRIOn_MEM_SIZE:
4877 Size of SRIO port 'n' memory region
4879 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4880 Defined to tell the NAND controller that the NAND chip is using
4882 Not all NAND drivers use this symbol.
4883 Example of drivers that use it:
4884 - drivers/mtd/nand/ndfc.c
4885 - drivers/mtd/nand/mxc_nand.c
4887 - CONFIG_SYS_NDFC_EBC0_CFG
4888 Sets the EBC0_CFG register for the NDFC. If not defined
4889 a default value will be used.
4892 Get DDR timing information from an I2C EEPROM. Common
4893 with pluggable memory modules such as SODIMMs
4896 I2C address of the SPD EEPROM
4898 - CONFIG_SYS_SPD_BUS_NUM
4899 If SPD EEPROM is on an I2C bus other than the first
4900 one, specify here. Note that the value must resolve
4901 to something your driver can deal with.
4903 - CONFIG_SYS_DDR_RAW_TIMING
4904 Get DDR timing information from other than SPD. Common with
4905 soldered DDR chips onboard without SPD. DDR raw timing
4906 parameters are extracted from datasheet and hard-coded into
4907 header files or board specific files.
4909 - CONFIG_FSL_DDR_INTERACTIVE
4910 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4912 - CONFIG_SYS_83XX_DDR_USES_CS0
4913 Only for 83xx systems. If specified, then DDR should
4914 be configured using CS0 and CS1 instead of CS2 and CS3.
4916 - CONFIG_ETHER_ON_FEC[12]
4917 Define to enable FEC[12] on a 8xx series processor.
4919 - CONFIG_FEC[12]_PHY
4920 Define to the hardcoded PHY address which corresponds
4921 to the given FEC; i. e.
4922 #define CONFIG_FEC1_PHY 4
4923 means that the PHY with address 4 is connected to FEC1
4925 When set to -1, means to probe for first available.
4927 - CONFIG_FEC[12]_PHY_NORXERR
4928 The PHY does not have a RXERR line (RMII only).
4929 (so program the FEC to ignore it).
4932 Enable RMII mode for all FECs.
4933 Note that this is a global option, we can't
4934 have one FEC in standard MII mode and another in RMII mode.
4936 - CONFIG_CRC32_VERIFY
4937 Add a verify option to the crc32 command.
4940 => crc32 -v <address> <count> <crc32>
4942 Where address/count indicate a memory area
4943 and crc32 is the correct crc32 which the
4947 Add the "loopw" memory command. This only takes effect if
4948 the memory commands are activated globally (CONFIG_CMD_MEM).
4951 Add the "mdc" and "mwc" memory commands. These are cyclic
4956 This command will print 4 bytes (10,11,12,13) each 500 ms.
4958 => mwc.l 100 12345678 10
4959 This command will write 12345678 to address 100 all 10 ms.
4961 This only takes effect if the memory commands are activated
4962 globally (CONFIG_CMD_MEM).
4964 - CONFIG_SKIP_LOWLEVEL_INIT
4965 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4966 low level initializations (like setting up the memory
4967 controller) are omitted and/or U-Boot does not
4968 relocate itself into RAM.
4970 Normally this variable MUST NOT be defined. The only
4971 exception is when U-Boot is loaded (to RAM) by some
4972 other boot loader or by a debugger which performs
4973 these initializations itself.
4976 Modifies the behaviour of start.S when compiling a loader
4977 that is executed before the actual U-Boot. E.g. when
4978 compiling a NAND SPL.
4981 Modifies the behaviour of start.S when compiling a loader
4982 that is executed after the SPL and before the actual U-Boot.
4983 It is loaded by the SPL.
4985 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4986 Only for 85xx systems. If this variable is specified, the section
4987 .resetvec is not kept and the section .bootpg is placed in the
4988 previous 4k of the .text section.
4990 - CONFIG_ARCH_MAP_SYSMEM
4991 Generally U-Boot (and in particular the md command) uses
4992 effective address. It is therefore not necessary to regard
4993 U-Boot address as virtual addresses that need to be translated
4994 to physical addresses. However, sandbox requires this, since
4995 it maintains its own little RAM buffer which contains all
4996 addressable memory. This option causes some memory accesses
4997 to be mapped through map_sysmem() / unmap_sysmem().
4999 - CONFIG_USE_ARCH_MEMCPY
5000 CONFIG_USE_ARCH_MEMSET
5001 If these options are used a optimized version of memcpy/memset will
5002 be used if available. These functions may be faster under some
5003 conditions but may increase the binary size.
5005 - CONFIG_X86_RESET_VECTOR
5006 If defined, the x86 reset vector code is included. This is not
5007 needed when U-Boot is running from Coreboot.
5010 Defines the MPU clock speed (in MHz).
5012 NOTE : currently only supported on AM335x platforms.
5014 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
5015 Enables the RTC32K OSC on AM33xx based plattforms
5017 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
5018 Option to disable subpage write in NAND driver
5019 driver that uses this:
5020 drivers/mtd/nand/davinci_nand.c
5022 Freescale QE/FMAN Firmware Support:
5023 -----------------------------------
5025 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
5026 loading of "firmware", which is encoded in the QE firmware binary format.
5027 This firmware often needs to be loaded during U-Boot booting, so macros
5028 are used to identify the storage device (NOR flash, SPI, etc) and the address
5031 - CONFIG_SYS_FMAN_FW_ADDR
5032 The address in the storage device where the FMAN microcode is located. The
5033 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5036 - CONFIG_SYS_QE_FW_ADDR
5037 The address in the storage device where the QE microcode is located. The
5038 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
5041 - CONFIG_SYS_QE_FMAN_FW_LENGTH
5042 The maximum possible size of the firmware. The firmware binary format
5043 has a field that specifies the actual size of the firmware, but it
5044 might not be possible to read any part of the firmware unless some
5045 local storage is allocated to hold the entire firmware first.
5047 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
5048 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
5049 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
5050 virtual address in NOR flash.
5052 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
5053 Specifies that QE/FMAN firmware is located in NAND flash.
5054 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
5056 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
5057 Specifies that QE/FMAN firmware is located on the primary SD/MMC
5058 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5060 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
5061 Specifies that QE/FMAN firmware is located on the primary SPI
5062 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
5064 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
5065 Specifies that QE/FMAN firmware is located in the remote (master)
5066 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
5067 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
5068 window->master inbound window->master LAW->the ucode address in
5069 master's memory space.
5071 Freescale Layerscape Management Complex Firmware Support:
5072 ---------------------------------------------------------
5073 The Freescale Layerscape Management Complex (MC) supports the loading of
5075 This firmware often needs to be loaded during U-Boot booting, so macros
5076 are used to identify the storage device (NOR flash, SPI, etc) and the address
5079 - CONFIG_FSL_MC_ENET
5080 Enable the MC driver for Layerscape SoCs.
5082 - CONFIG_SYS_LS_MC_FW_ADDR
5083 The address in the storage device where the firmware is located. The
5084 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
5087 - CONFIG_SYS_LS_MC_FW_LENGTH
5088 The maximum possible size of the firmware. The firmware binary format
5089 has a field that specifies the actual size of the firmware, but it
5090 might not be possible to read any part of the firmware unless some
5091 local storage is allocated to hold the entire firmware first.
5093 - CONFIG_SYS_LS_MC_FW_IN_NOR
5094 Specifies that MC firmware is located in NOR flash, mapped as
5095 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
5096 virtual address in NOR flash.
5098 Building the Software:
5099 ======================
5101 Building U-Boot has been tested in several native build environments
5102 and in many different cross environments. Of course we cannot support
5103 all possibly existing versions of cross development tools in all
5104 (potentially obsolete) versions. In case of tool chain problems we
5105 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5106 which is extensively used to build and test U-Boot.
5108 If you are not using a native environment, it is assumed that you
5109 have GNU cross compiling tools available in your path. In this case,
5110 you must set the environment variable CROSS_COMPILE in your shell.
5111 Note that no changes to the Makefile or any other source files are
5112 necessary. For example using the ELDK on a 4xx CPU, please enter:
5114 $ CROSS_COMPILE=ppc_4xx-
5115 $ export CROSS_COMPILE
5117 Note: If you wish to generate Windows versions of the utilities in
5118 the tools directory you can use the MinGW toolchain
5119 (http://www.mingw.org). Set your HOST tools to the MinGW
5120 toolchain and execute 'make tools'. For example:
5122 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5124 Binaries such as tools/mkimage.exe will be created which can
5125 be executed on computers running Windows.
5127 U-Boot is intended to be simple to build. After installing the
5128 sources you must configure U-Boot for one specific board type. This
5133 where "NAME_defconfig" is the name of one of the existing configu-
5134 rations; see boards.cfg for supported names.
5136 Note: for some board special configuration names may exist; check if
5137 additional information is available from the board vendor; for
5138 instance, the TQM823L systems are available without (standard)
5139 or with LCD support. You can select such additional "features"
5140 when choosing the configuration, i. e.
5142 make TQM823L_defconfig
5143 - will configure for a plain TQM823L, i. e. no LCD support
5145 make TQM823L_LCD_defconfig
5146 - will configure for a TQM823L with U-Boot console on LCD
5151 Finally, type "make all", and you should get some working U-Boot
5152 images ready for download to / installation on your system:
5154 - "u-boot.bin" is a raw binary image
5155 - "u-boot" is an image in ELF binary format
5156 - "u-boot.srec" is in Motorola S-Record format
5158 By default the build is performed locally and the objects are saved
5159 in the source directory. One of the two methods can be used to change
5160 this behavior and build U-Boot to some external directory:
5162 1. Add O= to the make command line invocations:
5164 make O=/tmp/build distclean
5165 make O=/tmp/build NAME_defconfig
5166 make O=/tmp/build all
5168 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5170 export KBUILD_OUTPUT=/tmp/build
5175 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5179 Please be aware that the Makefiles assume you are using GNU make, so
5180 for instance on NetBSD you might need to use "gmake" instead of
5184 If the system board that you have is not listed, then you will need
5185 to port U-Boot to your hardware platform. To do this, follow these
5188 1. Add a new configuration option for your board to the toplevel
5189 "boards.cfg" file, using the existing entries as examples.
5190 Follow the instructions there to keep the boards in order.
5191 2. Create a new directory to hold your board specific code. Add any
5192 files you need. In your board directory, you will need at least
5193 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
5194 3. Create a new configuration file "include/configs/<board>.h" for
5196 3. If you're porting U-Boot to a new CPU, then also create a new
5197 directory to hold your CPU specific code. Add any files you need.
5198 4. Run "make <board>_defconfig" with your new name.
5199 5. Type "make", and you should get a working "u-boot.srec" file
5200 to be installed on your target system.
5201 6. Debug and solve any problems that might arise.
5202 [Of course, this last step is much harder than it sounds.]
5205 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5206 ==============================================================
5208 If you have modified U-Boot sources (for instance added a new board
5209 or support for new devices, a new CPU, etc.) you are expected to
5210 provide feedback to the other developers. The feedback normally takes
5211 the form of a "patch", i. e. a context diff against a certain (latest
5212 official or latest in the git repository) version of U-Boot sources.
5214 But before you submit such a patch, please verify that your modifi-
5215 cation did not break existing code. At least make sure that *ALL* of
5216 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5217 just run the "MAKEALL" script, which will configure and build U-Boot
5218 for ALL supported system. Be warned, this will take a while. You can
5219 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5220 environment variable to the script, i. e. to use the ELDK cross tools
5223 CROSS_COMPILE=ppc_8xx- MAKEALL
5225 or to build on a native PowerPC system you can type
5227 CROSS_COMPILE=' ' MAKEALL
5229 When using the MAKEALL script, the default behaviour is to build
5230 U-Boot in the source directory. This location can be changed by
5231 setting the BUILD_DIR environment variable. Also, for each target
5232 built, the MAKEALL script saves two log files (<target>.ERR and
5233 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5234 location can be changed by setting the MAKEALL_LOGDIR environment
5235 variable. For example:
5237 export BUILD_DIR=/tmp/build
5238 export MAKEALL_LOGDIR=/tmp/log
5239 CROSS_COMPILE=ppc_8xx- MAKEALL
5241 With the above settings build objects are saved in the /tmp/build,
5242 log files are saved in the /tmp/log and the source tree remains clean
5243 during the whole build process.
5246 See also "U-Boot Porting Guide" below.
5249 Monitor Commands - Overview:
5250 ============================
5252 go - start application at address 'addr'
5253 run - run commands in an environment variable
5254 bootm - boot application image from memory
5255 bootp - boot image via network using BootP/TFTP protocol
5256 bootz - boot zImage from memory
5257 tftpboot- boot image via network using TFTP protocol
5258 and env variables "ipaddr" and "serverip"
5259 (and eventually "gatewayip")
5260 tftpput - upload a file via network using TFTP protocol
5261 rarpboot- boot image via network using RARP/TFTP protocol
5262 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5263 loads - load S-Record file over serial line
5264 loadb - load binary file over serial line (kermit mode)
5266 mm - memory modify (auto-incrementing)
5267 nm - memory modify (constant address)
5268 mw - memory write (fill)
5270 cmp - memory compare
5271 crc32 - checksum calculation
5272 i2c - I2C sub-system
5273 sspi - SPI utility commands
5274 base - print or set address offset
5275 printenv- print environment variables
5276 setenv - set environment variables
5277 saveenv - save environment variables to persistent storage
5278 protect - enable or disable FLASH write protection
5279 erase - erase FLASH memory
5280 flinfo - print FLASH memory information
5281 nand - NAND memory operations (see doc/README.nand)
5282 bdinfo - print Board Info structure
5283 iminfo - print header information for application image
5284 coninfo - print console devices and informations
5285 ide - IDE sub-system
5286 loop - infinite loop on address range
5287 loopw - infinite write loop on address range
5288 mtest - simple RAM test
5289 icache - enable or disable instruction cache
5290 dcache - enable or disable data cache
5291 reset - Perform RESET of the CPU
5292 echo - echo args to console
5293 version - print monitor version
5294 help - print online help
5295 ? - alias for 'help'
5298 Monitor Commands - Detailed Description:
5299 ========================================
5303 For now: just type "help <command>".
5306 Environment Variables:
5307 ======================
5309 U-Boot supports user configuration using Environment Variables which
5310 can be made persistent by saving to Flash memory.
5312 Environment Variables are set using "setenv", printed using
5313 "printenv", and saved to Flash using "saveenv". Using "setenv"
5314 without a value can be used to delete a variable from the
5315 environment. As long as you don't save the environment you are
5316 working with an in-memory copy. In case the Flash area containing the
5317 environment is erased by accident, a default environment is provided.
5319 Some configuration options can be set using Environment Variables.
5321 List of environment variables (most likely not complete):
5323 baudrate - see CONFIG_BAUDRATE
5325 bootdelay - see CONFIG_BOOTDELAY
5327 bootcmd - see CONFIG_BOOTCOMMAND
5329 bootargs - Boot arguments when booting an RTOS image
5331 bootfile - Name of the image to load with TFTP
5333 bootm_low - Memory range available for image processing in the bootm
5334 command can be restricted. This variable is given as
5335 a hexadecimal number and defines lowest address allowed
5336 for use by the bootm command. See also "bootm_size"
5337 environment variable. Address defined by "bootm_low" is
5338 also the base of the initial memory mapping for the Linux
5339 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5342 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5343 This variable is given as a hexadecimal number and it
5344 defines the size of the memory region starting at base
5345 address bootm_low that is accessible by the Linux kernel
5346 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5347 as the default value if it is defined, and bootm_size is
5350 bootm_size - Memory range available for image processing in the bootm
5351 command can be restricted. This variable is given as
5352 a hexadecimal number and defines the size of the region
5353 allowed for use by the bootm command. See also "bootm_low"
5354 environment variable.
5356 updatefile - Location of the software update file on a TFTP server, used
5357 by the automatic software update feature. Please refer to
5358 documentation in doc/README.update for more details.
5360 autoload - if set to "no" (any string beginning with 'n'),
5361 "bootp" will just load perform a lookup of the
5362 configuration from the BOOTP server, but not try to
5363 load any image using TFTP
5365 autostart - if set to "yes", an image loaded using the "bootp",
5366 "rarpboot", "tftpboot" or "diskboot" commands will
5367 be automatically started (by internally calling
5370 If set to "no", a standalone image passed to the
5371 "bootm" command will be copied to the load address
5372 (and eventually uncompressed), but NOT be started.
5373 This can be used to load and uncompress arbitrary
5376 fdt_high - if set this restricts the maximum address that the
5377 flattened device tree will be copied into upon boot.
5378 For example, if you have a system with 1 GB memory
5379 at physical address 0x10000000, while Linux kernel
5380 only recognizes the first 704 MB as low memory, you
5381 may need to set fdt_high as 0x3C000000 to have the
5382 device tree blob be copied to the maximum address
5383 of the 704 MB low memory, so that Linux kernel can
5384 access it during the boot procedure.
5386 If this is set to the special value 0xFFFFFFFF then
5387 the fdt will not be copied at all on boot. For this
5388 to work it must reside in writable memory, have
5389 sufficient padding on the end of it for u-boot to
5390 add the information it needs into it, and the memory
5391 must be accessible by the kernel.
5393 fdtcontroladdr- if set this is the address of the control flattened
5394 device tree used by U-Boot when CONFIG_OF_CONTROL is
5397 i2cfast - (PPC405GP|PPC405EP only)
5398 if set to 'y' configures Linux I2C driver for fast
5399 mode (400kHZ). This environment variable is used in
5400 initialization code. So, for changes to be effective
5401 it must be saved and board must be reset.
5403 initrd_high - restrict positioning of initrd images:
5404 If this variable is not set, initrd images will be
5405 copied to the highest possible address in RAM; this
5406 is usually what you want since it allows for
5407 maximum initrd size. If for some reason you want to
5408 make sure that the initrd image is loaded below the
5409 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5410 variable to a value of "no" or "off" or "0".
5411 Alternatively, you can set it to a maximum upper
5412 address to use (U-Boot will still check that it
5413 does not overwrite the U-Boot stack and data).
5415 For instance, when you have a system with 16 MB
5416 RAM, and want to reserve 4 MB from use by Linux,
5417 you can do this by adding "mem=12M" to the value of
5418 the "bootargs" variable. However, now you must make
5419 sure that the initrd image is placed in the first
5420 12 MB as well - this can be done with
5422 setenv initrd_high 00c00000
5424 If you set initrd_high to 0xFFFFFFFF, this is an
5425 indication to U-Boot that all addresses are legal
5426 for the Linux kernel, including addresses in flash
5427 memory. In this case U-Boot will NOT COPY the
5428 ramdisk at all. This may be useful to reduce the
5429 boot time on your system, but requires that this
5430 feature is supported by your Linux kernel.
5432 ipaddr - IP address; needed for tftpboot command
5434 loadaddr - Default load address for commands like "bootp",
5435 "rarpboot", "tftpboot", "loadb" or "diskboot"
5437 loads_echo - see CONFIG_LOADS_ECHO
5439 serverip - TFTP server IP address; needed for tftpboot command
5441 bootretry - see CONFIG_BOOT_RETRY_TIME
5443 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5445 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5447 ethprime - controls which interface is used first.
5449 ethact - controls which interface is currently active.
5450 For example you can do the following
5452 => setenv ethact FEC
5453 => ping 192.168.0.1 # traffic sent on FEC
5454 => setenv ethact SCC
5455 => ping 10.0.0.1 # traffic sent on SCC
5457 ethrotate - When set to "no" U-Boot does not go through all
5458 available network interfaces.
5459 It just stays at the currently selected interface.
5461 netretry - When set to "no" each network operation will
5462 either succeed or fail without retrying.
5463 When set to "once" the network operation will
5464 fail when all the available network interfaces
5465 are tried once without success.
5466 Useful on scripts which control the retry operation
5469 npe_ucode - set load address for the NPE microcode
5471 silent_linux - If set then Linux will be told to boot silently, by
5472 changing the console to be empty. If "yes" it will be
5473 made silent. If "no" it will not be made silent. If
5474 unset, then it will be made silent if the U-Boot console
5477 tftpsrcport - If this is set, the value is used for TFTP's
5480 tftpdstport - If this is set, the value is used for TFTP's UDP
5481 destination port instead of the Well Know Port 69.
5483 tftpblocksize - Block size to use for TFTP transfers; if not set,
5484 we use the TFTP server's default block size
5486 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5487 seconds, minimum value is 1000 = 1 second). Defines
5488 when a packet is considered to be lost so it has to
5489 be retransmitted. The default is 5000 = 5 seconds.
5490 Lowering this value may make downloads succeed
5491 faster in networks with high packet loss rates or
5492 with unreliable TFTP servers.
5494 vlan - When set to a value < 4095 the traffic over
5495 Ethernet is encapsulated/received over 802.1q
5498 The following image location variables contain the location of images
5499 used in booting. The "Image" column gives the role of the image and is
5500 not an environment variable name. The other columns are environment
5501 variable names. "File Name" gives the name of the file on a TFTP
5502 server, "RAM Address" gives the location in RAM the image will be
5503 loaded to, and "Flash Location" gives the image's address in NOR
5504 flash or offset in NAND flash.
5506 *Note* - these variables don't have to be defined for all boards, some
5507 boards currenlty use other variables for these purposes, and some
5508 boards use these variables for other purposes.
5510 Image File Name RAM Address Flash Location
5511 ----- --------- ----------- --------------
5512 u-boot u-boot u-boot_addr_r u-boot_addr
5513 Linux kernel bootfile kernel_addr_r kernel_addr
5514 device tree blob fdtfile fdt_addr_r fdt_addr
5515 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5517 The following environment variables may be used and automatically
5518 updated by the network boot commands ("bootp" and "rarpboot"),
5519 depending the information provided by your boot server:
5521 bootfile - see above
5522 dnsip - IP address of your Domain Name Server
5523 dnsip2 - IP address of your secondary Domain Name Server
5524 gatewayip - IP address of the Gateway (Router) to use
5525 hostname - Target hostname
5527 netmask - Subnet Mask
5528 rootpath - Pathname of the root filesystem on the NFS server
5529 serverip - see above
5532 There are two special Environment Variables:
5534 serial# - contains hardware identification information such
5535 as type string and/or serial number
5536 ethaddr - Ethernet address
5538 These variables can be set only once (usually during manufacturing of
5539 the board). U-Boot refuses to delete or overwrite these variables
5540 once they have been set once.
5543 Further special Environment Variables:
5545 ver - Contains the U-Boot version string as printed
5546 with the "version" command. This variable is
5547 readonly (see CONFIG_VERSION_VARIABLE).
5550 Please note that changes to some configuration parameters may take
5551 only effect after the next boot (yes, that's just like Windoze :-).
5554 Callback functions for environment variables:
5555 ---------------------------------------------
5557 For some environment variables, the behavior of u-boot needs to change
5558 when their values are changed. This functionality allows functions to
5559 be associated with arbitrary variables. On creation, overwrite, or
5560 deletion, the callback will provide the opportunity for some side
5561 effect to happen or for the change to be rejected.
5563 The callbacks are named and associated with a function using the
5564 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5566 These callbacks are associated with variables in one of two ways. The
5567 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5568 in the board configuration to a string that defines a list of
5569 associations. The list must be in the following format:
5571 entry = variable_name[:callback_name]
5574 If the callback name is not specified, then the callback is deleted.
5575 Spaces are also allowed anywhere in the list.
5577 Callbacks can also be associated by defining the ".callbacks" variable
5578 with the same list format above. Any association in ".callbacks" will
5579 override any association in the static list. You can define
5580 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5581 ".callbacks" environment variable in the default or embedded environment.
5584 Command Line Parsing:
5585 =====================
5587 There are two different command line parsers available with U-Boot:
5588 the old "simple" one, and the much more powerful "hush" shell:
5590 Old, simple command line parser:
5591 --------------------------------
5593 - supports environment variables (through setenv / saveenv commands)
5594 - several commands on one line, separated by ';'
5595 - variable substitution using "... ${name} ..." syntax
5596 - special characters ('$', ';') can be escaped by prefixing with '\',
5598 setenv bootcmd bootm \${address}
5599 - You can also escape text by enclosing in single apostrophes, for example:
5600 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5605 - similar to Bourne shell, with control structures like
5606 if...then...else...fi, for...do...done; while...do...done,
5607 until...do...done, ...
5608 - supports environment ("global") variables (through setenv / saveenv
5609 commands) and local shell variables (through standard shell syntax
5610 "name=value"); only environment variables can be used with "run"
5616 (1) If a command line (or an environment variable executed by a "run"
5617 command) contains several commands separated by semicolon, and
5618 one of these commands fails, then the remaining commands will be
5621 (2) If you execute several variables with one call to run (i. e.
5622 calling run with a list of variables as arguments), any failing
5623 command will cause "run" to terminate, i. e. the remaining
5624 variables are not executed.
5626 Note for Redundant Ethernet Interfaces:
5627 =======================================
5629 Some boards come with redundant Ethernet interfaces; U-Boot supports
5630 such configurations and is capable of automatic selection of a
5631 "working" interface when needed. MAC assignment works as follows:
5633 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5634 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5635 "eth1addr" (=>eth1), "eth2addr", ...
5637 If the network interface stores some valid MAC address (for instance
5638 in SROM), this is used as default address if there is NO correspon-
5639 ding setting in the environment; if the corresponding environment
5640 variable is set, this overrides the settings in the card; that means:
5642 o If the SROM has a valid MAC address, and there is no address in the
5643 environment, the SROM's address is used.
5645 o If there is no valid address in the SROM, and a definition in the
5646 environment exists, then the value from the environment variable is
5649 o If both the SROM and the environment contain a MAC address, and
5650 both addresses are the same, this MAC address is used.
5652 o If both the SROM and the environment contain a MAC address, and the
5653 addresses differ, the value from the environment is used and a
5656 o If neither SROM nor the environment contain a MAC address, an error
5659 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5660 will be programmed into hardware as part of the initialization process. This
5661 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5662 The naming convention is as follows:
5663 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5668 U-Boot is capable of booting (and performing other auxiliary operations on)
5669 images in two formats:
5671 New uImage format (FIT)
5672 -----------------------
5674 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5675 to Flattened Device Tree). It allows the use of images with multiple
5676 components (several kernels, ramdisks, etc.), with contents protected by
5677 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5683 Old image format is based on binary files which can be basically anything,
5684 preceded by a special header; see the definitions in include/image.h for
5685 details; basically, the header defines the following image properties:
5687 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5688 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5689 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5690 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5692 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5693 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5694 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5695 * Compression Type (uncompressed, gzip, bzip2)
5701 The header is marked by a special Magic Number, and both the header
5702 and the data portions of the image are secured against corruption by
5709 Although U-Boot should support any OS or standalone application
5710 easily, the main focus has always been on Linux during the design of
5713 U-Boot includes many features that so far have been part of some
5714 special "boot loader" code within the Linux kernel. Also, any
5715 "initrd" images to be used are no longer part of one big Linux image;
5716 instead, kernel and "initrd" are separate images. This implementation
5717 serves several purposes:
5719 - the same features can be used for other OS or standalone
5720 applications (for instance: using compressed images to reduce the
5721 Flash memory footprint)
5723 - it becomes much easier to port new Linux kernel versions because
5724 lots of low-level, hardware dependent stuff are done by U-Boot
5726 - the same Linux kernel image can now be used with different "initrd"
5727 images; of course this also means that different kernel images can
5728 be run with the same "initrd". This makes testing easier (you don't
5729 have to build a new "zImage.initrd" Linux image when you just
5730 change a file in your "initrd"). Also, a field-upgrade of the
5731 software is easier now.
5737 Porting Linux to U-Boot based systems:
5738 ---------------------------------------
5740 U-Boot cannot save you from doing all the necessary modifications to
5741 configure the Linux device drivers for use with your target hardware
5742 (no, we don't intend to provide a full virtual machine interface to
5745 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5747 Just make sure your machine specific header file (for instance
5748 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5749 Information structure as we define in include/asm-<arch>/u-boot.h,
5750 and make sure that your definition of IMAP_ADDR uses the same value
5751 as your U-Boot configuration in CONFIG_SYS_IMMR.
5753 Note that U-Boot now has a driver model, a unified model for drivers.
5754 If you are adding a new driver, plumb it into driver model. If there
5755 is no uclass available, you are encouraged to create one. See
5759 Configuring the Linux kernel:
5760 -----------------------------
5762 No specific requirements for U-Boot. Make sure you have some root
5763 device (initial ramdisk, NFS) for your target system.
5766 Building a Linux Image:
5767 -----------------------
5769 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5770 not used. If you use recent kernel source, a new build target
5771 "uImage" will exist which automatically builds an image usable by
5772 U-Boot. Most older kernels also have support for a "pImage" target,
5773 which was introduced for our predecessor project PPCBoot and uses a
5774 100% compatible format.
5778 make TQM850L_defconfig
5783 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5784 encapsulate a compressed Linux kernel image with header information,
5785 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5787 * build a standard "vmlinux" kernel image (in ELF binary format):
5789 * convert the kernel into a raw binary image:
5791 ${CROSS_COMPILE}-objcopy -O binary \
5792 -R .note -R .comment \
5793 -S vmlinux linux.bin
5795 * compress the binary image:
5799 * package compressed binary image for U-Boot:
5801 mkimage -A ppc -O linux -T kernel -C gzip \
5802 -a 0 -e 0 -n "Linux Kernel Image" \
5803 -d linux.bin.gz uImage
5806 The "mkimage" tool can also be used to create ramdisk images for use
5807 with U-Boot, either separated from the Linux kernel image, or
5808 combined into one file. "mkimage" encapsulates the images with a 64
5809 byte header containing information about target architecture,
5810 operating system, image type, compression method, entry points, time
5811 stamp, CRC32 checksums, etc.
5813 "mkimage" can be called in two ways: to verify existing images and
5814 print the header information, or to build new images.
5816 In the first form (with "-l" option) mkimage lists the information
5817 contained in the header of an existing U-Boot image; this includes
5818 checksum verification:
5820 tools/mkimage -l image
5821 -l ==> list image header information
5823 The second form (with "-d" option) is used to build a U-Boot image
5824 from a "data file" which is used as image payload:
5826 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5827 -n name -d data_file image
5828 -A ==> set architecture to 'arch'
5829 -O ==> set operating system to 'os'
5830 -T ==> set image type to 'type'
5831 -C ==> set compression type 'comp'
5832 -a ==> set load address to 'addr' (hex)
5833 -e ==> set entry point to 'ep' (hex)
5834 -n ==> set image name to 'name'
5835 -d ==> use image data from 'datafile'
5837 Right now, all Linux kernels for PowerPC systems use the same load
5838 address (0x00000000), but the entry point address depends on the
5841 - 2.2.x kernels have the entry point at 0x0000000C,
5842 - 2.3.x and later kernels have the entry point at 0x00000000.
5844 So a typical call to build a U-Boot image would read:
5846 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5847 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5848 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5849 > examples/uImage.TQM850L
5850 Image Name: 2.4.4 kernel for TQM850L
5851 Created: Wed Jul 19 02:34:59 2000
5852 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5853 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5854 Load Address: 0x00000000
5855 Entry Point: 0x00000000
5857 To verify the contents of the image (or check for corruption):
5859 -> tools/mkimage -l examples/uImage.TQM850L
5860 Image Name: 2.4.4 kernel for TQM850L
5861 Created: Wed Jul 19 02:34:59 2000
5862 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5863 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5864 Load Address: 0x00000000
5865 Entry Point: 0x00000000
5867 NOTE: for embedded systems where boot time is critical you can trade
5868 speed for memory and install an UNCOMPRESSED image instead: this
5869 needs more space in Flash, but boots much faster since it does not
5870 need to be uncompressed:
5872 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5873 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5874 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5875 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5876 > examples/uImage.TQM850L-uncompressed
5877 Image Name: 2.4.4 kernel for TQM850L
5878 Created: Wed Jul 19 02:34:59 2000
5879 Image Type: PowerPC Linux Kernel Image (uncompressed)
5880 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5881 Load Address: 0x00000000
5882 Entry Point: 0x00000000
5885 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5886 when your kernel is intended to use an initial ramdisk:
5888 -> tools/mkimage -n 'Simple Ramdisk Image' \
5889 > -A ppc -O linux -T ramdisk -C gzip \
5890 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5891 Image Name: Simple Ramdisk Image
5892 Created: Wed Jan 12 14:01:50 2000
5893 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5894 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5895 Load Address: 0x00000000
5896 Entry Point: 0x00000000
5898 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5899 option performs the converse operation of the mkimage's second form (the "-d"
5900 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5903 tools/dumpimage -i image -p position data_file
5904 -i ==> extract from the 'image' a specific 'data_file', \
5905 indexed by 'position'
5908 Installing a Linux Image:
5909 -------------------------
5911 To downloading a U-Boot image over the serial (console) interface,
5912 you must convert the image to S-Record format:
5914 objcopy -I binary -O srec examples/image examples/image.srec
5916 The 'objcopy' does not understand the information in the U-Boot
5917 image header, so the resulting S-Record file will be relative to
5918 address 0x00000000. To load it to a given address, you need to
5919 specify the target address as 'offset' parameter with the 'loads'
5922 Example: install the image to address 0x40100000 (which on the
5923 TQM8xxL is in the first Flash bank):
5925 => erase 40100000 401FFFFF
5931 ## Ready for S-Record download ...
5932 ~>examples/image.srec
5933 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5935 15989 15990 15991 15992
5936 [file transfer complete]
5938 ## Start Addr = 0x00000000
5941 You can check the success of the download using the 'iminfo' command;
5942 this includes a checksum verification so you can be sure no data
5943 corruption happened:
5947 ## Checking Image at 40100000 ...
5948 Image Name: 2.2.13 for initrd on TQM850L
5949 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5950 Data Size: 335725 Bytes = 327 kB = 0 MB
5951 Load Address: 00000000
5952 Entry Point: 0000000c
5953 Verifying Checksum ... OK
5959 The "bootm" command is used to boot an application that is stored in
5960 memory (RAM or Flash). In case of a Linux kernel image, the contents
5961 of the "bootargs" environment variable is passed to the kernel as
5962 parameters. You can check and modify this variable using the
5963 "printenv" and "setenv" commands:
5966 => printenv bootargs
5967 bootargs=root=/dev/ram
5969 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5971 => printenv bootargs
5972 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5975 ## Booting Linux kernel at 40020000 ...
5976 Image Name: 2.2.13 for NFS on TQM850L
5977 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5978 Data Size: 381681 Bytes = 372 kB = 0 MB
5979 Load Address: 00000000
5980 Entry Point: 0000000c
5981 Verifying Checksum ... OK
5982 Uncompressing Kernel Image ... OK
5983 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
5984 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5985 time_init: decrementer frequency = 187500000/60
5986 Calibrating delay loop... 49.77 BogoMIPS
5987 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5990 If you want to boot a Linux kernel with initial RAM disk, you pass
5991 the memory addresses of both the kernel and the initrd image (PPBCOOT
5992 format!) to the "bootm" command:
5994 => imi 40100000 40200000
5996 ## Checking Image at 40100000 ...
5997 Image Name: 2.2.13 for initrd on TQM850L
5998 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5999 Data Size: 335725 Bytes = 327 kB = 0 MB
6000 Load Address: 00000000
6001 Entry Point: 0000000c
6002 Verifying Checksum ... OK
6004 ## Checking Image at 40200000 ...
6005 Image Name: Simple Ramdisk Image
6006 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6007 Data Size: 566530 Bytes = 553 kB = 0 MB
6008 Load Address: 00000000
6009 Entry Point: 00000000
6010 Verifying Checksum ... OK
6012 => bootm 40100000 40200000
6013 ## Booting Linux kernel at 40100000 ...
6014 Image Name: 2.2.13 for initrd on TQM850L
6015 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6016 Data Size: 335725 Bytes = 327 kB = 0 MB
6017 Load Address: 00000000
6018 Entry Point: 0000000c
6019 Verifying Checksum ... OK
6020 Uncompressing Kernel Image ... OK
6021 ## Loading RAMDisk Image at 40200000 ...
6022 Image Name: Simple Ramdisk Image
6023 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
6024 Data Size: 566530 Bytes = 553 kB = 0 MB
6025 Load Address: 00000000
6026 Entry Point: 00000000
6027 Verifying Checksum ... OK
6028 Loading Ramdisk ... OK
6029 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
6030 Boot arguments: root=/dev/ram
6031 time_init: decrementer frequency = 187500000/60
6032 Calibrating delay loop... 49.77 BogoMIPS
6034 RAMDISK: Compressed image found at block 0
6035 VFS: Mounted root (ext2 filesystem).
6039 Boot Linux and pass a flat device tree:
6042 First, U-Boot must be compiled with the appropriate defines. See the section
6043 titled "Linux Kernel Interface" above for a more in depth explanation. The
6044 following is an example of how to start a kernel and pass an updated
6050 oft=oftrees/mpc8540ads.dtb
6051 => tftp $oftaddr $oft
6052 Speed: 1000, full duplex
6054 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
6055 Filename 'oftrees/mpc8540ads.dtb'.
6056 Load address: 0x300000
6059 Bytes transferred = 4106 (100a hex)
6060 => tftp $loadaddr $bootfile
6061 Speed: 1000, full duplex
6063 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6065 Load address: 0x200000
6066 Loading:############
6068 Bytes transferred = 1029407 (fb51f hex)
6073 => bootm $loadaddr - $oftaddr
6074 ## Booting image at 00200000 ...
6075 Image Name: Linux-2.6.17-dirty
6076 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6077 Data Size: 1029343 Bytes = 1005.2 kB
6078 Load Address: 00000000
6079 Entry Point: 00000000
6080 Verifying Checksum ... OK
6081 Uncompressing Kernel Image ... OK
6082 Booting using flat device tree at 0x300000
6083 Using MPC85xx ADS machine description
6084 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6088 More About U-Boot Image Types:
6089 ------------------------------
6091 U-Boot supports the following image types:
6093 "Standalone Programs" are directly runnable in the environment
6094 provided by U-Boot; it is expected that (if they behave
6095 well) you can continue to work in U-Boot after return from
6096 the Standalone Program.
6097 "OS Kernel Images" are usually images of some Embedded OS which
6098 will take over control completely. Usually these programs
6099 will install their own set of exception handlers, device
6100 drivers, set up the MMU, etc. - this means, that you cannot
6101 expect to re-enter U-Boot except by resetting the CPU.
6102 "RAMDisk Images" are more or less just data blocks, and their
6103 parameters (address, size) are passed to an OS kernel that is
6105 "Multi-File Images" contain several images, typically an OS
6106 (Linux) kernel image and one or more data images like
6107 RAMDisks. This construct is useful for instance when you want
6108 to boot over the network using BOOTP etc., where the boot
6109 server provides just a single image file, but you want to get
6110 for instance an OS kernel and a RAMDisk image.
6112 "Multi-File Images" start with a list of image sizes, each
6113 image size (in bytes) specified by an "uint32_t" in network
6114 byte order. This list is terminated by an "(uint32_t)0".
6115 Immediately after the terminating 0 follow the images, one by
6116 one, all aligned on "uint32_t" boundaries (size rounded up to
6117 a multiple of 4 bytes).
6119 "Firmware Images" are binary images containing firmware (like
6120 U-Boot or FPGA images) which usually will be programmed to
6123 "Script files" are command sequences that will be executed by
6124 U-Boot's command interpreter; this feature is especially
6125 useful when you configure U-Boot to use a real shell (hush)
6126 as command interpreter.
6128 Booting the Linux zImage:
6129 -------------------------
6131 On some platforms, it's possible to boot Linux zImage. This is done
6132 using the "bootz" command. The syntax of "bootz" command is the same
6133 as the syntax of "bootm" command.
6135 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6136 kernel with raw initrd images. The syntax is slightly different, the
6137 address of the initrd must be augmented by it's size, in the following
6138 format: "<initrd addres>:<initrd size>".
6144 One of the features of U-Boot is that you can dynamically load and
6145 run "standalone" applications, which can use some resources of
6146 U-Boot like console I/O functions or interrupt services.
6148 Two simple examples are included with the sources:
6153 'examples/hello_world.c' contains a small "Hello World" Demo
6154 application; it is automatically compiled when you build U-Boot.
6155 It's configured to run at address 0x00040004, so you can play with it
6159 ## Ready for S-Record download ...
6160 ~>examples/hello_world.srec
6161 1 2 3 4 5 6 7 8 9 10 11 ...
6162 [file transfer complete]
6164 ## Start Addr = 0x00040004
6166 => go 40004 Hello World! This is a test.
6167 ## Starting application at 0x00040004 ...
6178 Hit any key to exit ...
6180 ## Application terminated, rc = 0x0
6182 Another example, which demonstrates how to register a CPM interrupt
6183 handler with the U-Boot code, can be found in 'examples/timer.c'.
6184 Here, a CPM timer is set up to generate an interrupt every second.
6185 The interrupt service routine is trivial, just printing a '.'
6186 character, but this is just a demo program. The application can be
6187 controlled by the following keys:
6189 ? - print current values og the CPM Timer registers
6190 b - enable interrupts and start timer
6191 e - stop timer and disable interrupts
6192 q - quit application
6195 ## Ready for S-Record download ...
6196 ~>examples/timer.srec
6197 1 2 3 4 5 6 7 8 9 10 11 ...
6198 [file transfer complete]
6200 ## Start Addr = 0x00040004
6203 ## Starting application at 0x00040004 ...
6206 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6209 [q, b, e, ?] Set interval 1000000 us
6212 [q, b, e, ?] ........
6213 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6216 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6219 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6222 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6224 [q, b, e, ?] ...Stopping timer
6226 [q, b, e, ?] ## Application terminated, rc = 0x0
6232 Over time, many people have reported problems when trying to use the
6233 "minicom" terminal emulation program for serial download. I (wd)
6234 consider minicom to be broken, and recommend not to use it. Under
6235 Unix, I recommend to use C-Kermit for general purpose use (and
6236 especially for kermit binary protocol download ("loadb" command), and
6237 use "cu" for S-Record download ("loads" command). See
6238 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6239 for help with kermit.
6242 Nevertheless, if you absolutely want to use it try adding this
6243 configuration to your "File transfer protocols" section:
6245 Name Program Name U/D FullScr IO-Red. Multi
6246 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6247 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6253 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6254 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6256 Building requires a cross environment; it is known to work on
6257 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6258 need gmake since the Makefiles are not compatible with BSD make).
6259 Note that the cross-powerpc package does not install include files;
6260 attempting to build U-Boot will fail because <machine/ansi.h> is
6261 missing. This file has to be installed and patched manually:
6263 # cd /usr/pkg/cross/powerpc-netbsd/include
6265 # ln -s powerpc machine
6266 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6267 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6269 Native builds *don't* work due to incompatibilities between native
6270 and U-Boot include files.
6272 Booting assumes that (the first part of) the image booted is a
6273 stage-2 loader which in turn loads and then invokes the kernel
6274 proper. Loader sources will eventually appear in the NetBSD source
6275 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6276 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6279 Implementation Internals:
6280 =========================
6282 The following is not intended to be a complete description of every
6283 implementation detail. However, it should help to understand the
6284 inner workings of U-Boot and make it easier to port it to custom
6288 Initial Stack, Global Data:
6289 ---------------------------
6291 The implementation of U-Boot is complicated by the fact that U-Boot
6292 starts running out of ROM (flash memory), usually without access to
6293 system RAM (because the memory controller is not initialized yet).
6294 This means that we don't have writable Data or BSS segments, and BSS
6295 is not initialized as zero. To be able to get a C environment working
6296 at all, we have to allocate at least a minimal stack. Implementation
6297 options for this are defined and restricted by the CPU used: Some CPU
6298 models provide on-chip memory (like the IMMR area on MPC8xx and
6299 MPC826x processors), on others (parts of) the data cache can be
6300 locked as (mis-) used as memory, etc.
6302 Chris Hallinan posted a good summary of these issues to the
6303 U-Boot mailing list:
6305 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6306 From: "Chris Hallinan" <clh@net1plus.com>
6307 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6310 Correct me if I'm wrong, folks, but the way I understand it
6311 is this: Using DCACHE as initial RAM for Stack, etc, does not
6312 require any physical RAM backing up the cache. The cleverness
6313 is that the cache is being used as a temporary supply of
6314 necessary storage before the SDRAM controller is setup. It's
6315 beyond the scope of this list to explain the details, but you
6316 can see how this works by studying the cache architecture and
6317 operation in the architecture and processor-specific manuals.
6319 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6320 is another option for the system designer to use as an
6321 initial stack/RAM area prior to SDRAM being available. Either
6322 option should work for you. Using CS 4 should be fine if your
6323 board designers haven't used it for something that would
6324 cause you grief during the initial boot! It is frequently not
6327 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6328 with your processor/board/system design. The default value
6329 you will find in any recent u-boot distribution in
6330 walnut.h should work for you. I'd set it to a value larger
6331 than your SDRAM module. If you have a 64MB SDRAM module, set
6332 it above 400_0000. Just make sure your board has no resources
6333 that are supposed to respond to that address! That code in
6334 start.S has been around a while and should work as is when
6335 you get the config right.
6340 It is essential to remember this, since it has some impact on the C
6341 code for the initialization procedures:
6343 * Initialized global data (data segment) is read-only. Do not attempt
6346 * Do not use any uninitialized global data (or implicitly initialized
6347 as zero data - BSS segment) at all - this is undefined, initiali-
6348 zation is performed later (when relocating to RAM).
6350 * Stack space is very limited. Avoid big data buffers or things like
6353 Having only the stack as writable memory limits means we cannot use
6354 normal global data to share information between the code. But it
6355 turned out that the implementation of U-Boot can be greatly
6356 simplified by making a global data structure (gd_t) available to all
6357 functions. We could pass a pointer to this data as argument to _all_
6358 functions, but this would bloat the code. Instead we use a feature of
6359 the GCC compiler (Global Register Variables) to share the data: we
6360 place a pointer (gd) to the global data into a register which we
6361 reserve for this purpose.
6363 When choosing a register for such a purpose we are restricted by the
6364 relevant (E)ABI specifications for the current architecture, and by
6365 GCC's implementation.
6367 For PowerPC, the following registers have specific use:
6369 R2: reserved for system use
6370 R3-R4: parameter passing and return values
6371 R5-R10: parameter passing
6372 R13: small data area pointer
6376 (U-Boot also uses R12 as internal GOT pointer. r12
6377 is a volatile register so r12 needs to be reset when
6378 going back and forth between asm and C)
6380 ==> U-Boot will use R2 to hold a pointer to the global data
6382 Note: on PPC, we could use a static initializer (since the
6383 address of the global data structure is known at compile time),
6384 but it turned out that reserving a register results in somewhat
6385 smaller code - although the code savings are not that big (on
6386 average for all boards 752 bytes for the whole U-Boot image,
6387 624 text + 127 data).
6389 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6390 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6392 ==> U-Boot will use P3 to hold a pointer to the global data
6394 On ARM, the following registers are used:
6396 R0: function argument word/integer result
6397 R1-R3: function argument word
6398 R9: platform specific
6399 R10: stack limit (used only if stack checking is enabled)
6400 R11: argument (frame) pointer
6401 R12: temporary workspace
6404 R15: program counter
6406 ==> U-Boot will use R9 to hold a pointer to the global data
6408 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6410 On Nios II, the ABI is documented here:
6411 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6413 ==> U-Boot will use gp to hold a pointer to the global data
6415 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6416 to access small data sections, so gp is free.
6418 On NDS32, the following registers are used:
6420 R0-R1: argument/return
6422 R15: temporary register for assembler
6423 R16: trampoline register
6424 R28: frame pointer (FP)
6425 R29: global pointer (GP)
6426 R30: link register (LP)
6427 R31: stack pointer (SP)
6428 PC: program counter (PC)
6430 ==> U-Boot will use R10 to hold a pointer to the global data
6432 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6433 or current versions of GCC may "optimize" the code too much.
6438 U-Boot runs in system state and uses physical addresses, i.e. the
6439 MMU is not used either for address mapping nor for memory protection.
6441 The available memory is mapped to fixed addresses using the memory
6442 controller. In this process, a contiguous block is formed for each
6443 memory type (Flash, SDRAM, SRAM), even when it consists of several
6444 physical memory banks.
6446 U-Boot is installed in the first 128 kB of the first Flash bank (on
6447 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6448 booting and sizing and initializing DRAM, the code relocates itself
6449 to the upper end of DRAM. Immediately below the U-Boot code some
6450 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6451 configuration setting]. Below that, a structure with global Board
6452 Info data is placed, followed by the stack (growing downward).
6454 Additionally, some exception handler code is copied to the low 8 kB
6455 of DRAM (0x00000000 ... 0x00001FFF).
6457 So a typical memory configuration with 16 MB of DRAM could look like
6460 0x0000 0000 Exception Vector code
6463 0x0000 2000 Free for Application Use
6469 0x00FB FF20 Monitor Stack (Growing downward)
6470 0x00FB FFAC Board Info Data and permanent copy of global data
6471 0x00FC 0000 Malloc Arena
6474 0x00FE 0000 RAM Copy of Monitor Code
6475 ... eventually: LCD or video framebuffer
6476 ... eventually: pRAM (Protected RAM - unchanged by reset)
6477 0x00FF FFFF [End of RAM]
6480 System Initialization:
6481 ----------------------
6483 In the reset configuration, U-Boot starts at the reset entry point
6484 (on most PowerPC systems at address 0x00000100). Because of the reset
6485 configuration for CS0# this is a mirror of the on board Flash memory.
6486 To be able to re-map memory U-Boot then jumps to its link address.
6487 To be able to implement the initialization code in C, a (small!)
6488 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6489 which provide such a feature like MPC8xx or MPC8260), or in a locked
6490 part of the data cache. After that, U-Boot initializes the CPU core,
6491 the caches and the SIU.
6493 Next, all (potentially) available memory banks are mapped using a
6494 preliminary mapping. For example, we put them on 512 MB boundaries
6495 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6496 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6497 programmed for SDRAM access. Using the temporary configuration, a
6498 simple memory test is run that determines the size of the SDRAM
6501 When there is more than one SDRAM bank, and the banks are of
6502 different size, the largest is mapped first. For equal size, the first
6503 bank (CS2#) is mapped first. The first mapping is always for address
6504 0x00000000, with any additional banks following immediately to create
6505 contiguous memory starting from 0.
6507 Then, the monitor installs itself at the upper end of the SDRAM area
6508 and allocates memory for use by malloc() and for the global Board
6509 Info data; also, the exception vector code is copied to the low RAM
6510 pages, and the final stack is set up.
6512 Only after this relocation will you have a "normal" C environment;
6513 until that you are restricted in several ways, mostly because you are
6514 running from ROM, and because the code will have to be relocated to a
6518 U-Boot Porting Guide:
6519 ----------------------
6521 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6525 int main(int argc, char *argv[])
6527 sighandler_t no_more_time;
6529 signal(SIGALRM, no_more_time);
6530 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6532 if (available_money > available_manpower) {
6533 Pay consultant to port U-Boot;
6537 Download latest U-Boot source;
6539 Subscribe to u-boot mailing list;
6542 email("Hi, I am new to U-Boot, how do I get started?");
6545 Read the README file in the top level directory;
6546 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6547 Read applicable doc/*.README;
6548 Read the source, Luke;
6549 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6552 if (available_money > toLocalCurrency ($2500))
6555 Add a lot of aggravation and time;
6557 if (a similar board exists) { /* hopefully... */
6558 cp -a board/<similar> board/<myboard>
6559 cp include/configs/<similar>.h include/configs/<myboard>.h
6561 Create your own board support subdirectory;
6562 Create your own board include/configs/<myboard>.h file;
6564 Edit new board/<myboard> files
6565 Edit new include/configs/<myboard>.h
6570 Add / modify source code;
6574 email("Hi, I am having problems...");
6576 Send patch file to the U-Boot email list;
6577 if (reasonable critiques)
6578 Incorporate improvements from email list code review;
6580 Defend code as written;
6586 void no_more_time (int sig)
6595 All contributions to U-Boot should conform to the Linux kernel
6596 coding style; see the file "Documentation/CodingStyle" and the script
6597 "scripts/Lindent" in your Linux kernel source directory.
6599 Source files originating from a different project (for example the
6600 MTD subsystem) are generally exempt from these guidelines and are not
6601 reformatted to ease subsequent migration to newer versions of those
6604 Please note that U-Boot is implemented in C (and to some small parts in
6605 Assembler); no C++ is used, so please do not use C++ style comments (//)
6608 Please also stick to the following formatting rules:
6609 - remove any trailing white space
6610 - use TAB characters for indentation and vertical alignment, not spaces
6611 - make sure NOT to use DOS '\r\n' line feeds
6612 - do not add more than 2 consecutive empty lines to source files
6613 - do not add trailing empty lines to source files
6615 Submissions which do not conform to the standards may be returned
6616 with a request to reformat the changes.
6622 Since the number of patches for U-Boot is growing, we need to
6623 establish some rules. Submissions which do not conform to these rules
6624 may be rejected, even when they contain important and valuable stuff.
6626 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6628 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6629 see http://lists.denx.de/mailman/listinfo/u-boot
6631 When you send a patch, please include the following information with
6634 * For bug fixes: a description of the bug and how your patch fixes
6635 this bug. Please try to include a way of demonstrating that the
6636 patch actually fixes something.
6638 * For new features: a description of the feature and your
6641 * A CHANGELOG entry as plaintext (separate from the patch)
6643 * For major contributions, your entry to the CREDITS file
6645 * When you add support for a new board, don't forget to add a
6646 maintainer e-mail address to the boards.cfg file, too.
6648 * If your patch adds new configuration options, don't forget to
6649 document these in the README file.
6651 * The patch itself. If you are using git (which is *strongly*
6652 recommended) you can easily generate the patch using the
6653 "git format-patch". If you then use "git send-email" to send it to
6654 the U-Boot mailing list, you will avoid most of the common problems
6655 with some other mail clients.
6657 If you cannot use git, use "diff -purN OLD NEW". If your version of
6658 diff does not support these options, then get the latest version of
6661 The current directory when running this command shall be the parent
6662 directory of the U-Boot source tree (i. e. please make sure that
6663 your patch includes sufficient directory information for the
6666 We prefer patches as plain text. MIME attachments are discouraged,
6667 and compressed attachments must not be used.
6669 * If one logical set of modifications affects or creates several
6670 files, all these changes shall be submitted in a SINGLE patch file.
6672 * Changesets that contain different, unrelated modifications shall be
6673 submitted as SEPARATE patches, one patch per changeset.
6678 * Before sending the patch, run the MAKEALL script on your patched
6679 source tree and make sure that no errors or warnings are reported
6680 for any of the boards.
6682 * Keep your modifications to the necessary minimum: A patch
6683 containing several unrelated changes or arbitrary reformats will be
6684 returned with a request to re-formatting / split it.
6686 * If you modify existing code, make sure that your new code does not
6687 add to the memory footprint of the code ;-) Small is beautiful!
6688 When adding new features, these should compile conditionally only
6689 (using #ifdef), and the resulting code with the new feature
6690 disabled must not need more memory than the old code without your
6693 * Remember that there is a size limit of 100 kB per message on the
6694 u-boot mailing list. Bigger patches will be moderated. If they are
6695 reasonable and not too big, they will be acknowledged. But patches
6696 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob