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 file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
52 In case you have questions about, problems with or contributions for
53 U-Boot, you should send a message to the U-Boot mailing list at
54 <u-boot@lists.denx.de>. There is also an archive of previous traffic
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
60 Where to get source code:
61 =========================
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
82 - make it easier to add custom boards
83 - make it possible to add other [PowerPC] CPUs
84 - extend functions, especially:
85 * Provide extended interface to Linux boot loader
88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
89 - create ARMBoot project (http://sourceforge.net/projects/armboot)
90 - add other CPU families (starting with ARM)
91 - create U-Boot project (http://sourceforge.net/projects/u-boot)
92 - current project page: see http://www.denx.de/wiki/U-Boot
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
102 This is the README file for the U-Boot project.
104 File names etc. shall be based on the string "u-boot". Examples:
106 include/asm-ppc/u-boot.h
108 #include <asm/u-boot.h>
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
128 U-Boot v2009.11 - Release November 2009
129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
130 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /blackfin Files generic to Analog Devices Blackfin architecture
141 /m68k Files generic to m68k architecture
142 /microblaze Files generic to microblaze architecture
143 /mips Files generic to MIPS architecture
144 /nds32 Files generic to NDS32 architecture
145 /nios2 Files generic to Altera NIOS2 architecture
146 /openrisc Files generic to OpenRISC architecture
147 /powerpc Files generic to PowerPC architecture
148 /sandbox Files generic to HW-independent "sandbox"
149 /sh Files generic to SH architecture
150 /sparc Files generic to SPARC architecture
151 /x86 Files generic to x86 architecture
152 /api Machine/arch independent API for external apps
153 /board Board dependent files
154 /common Misc architecture independent functions
155 /configs Board default configuration files
156 /disk Code for disk drive partition handling
157 /doc Documentation (don't expect too much)
158 /drivers Commonly used device drivers
159 /dts Contains Makefile for building internal U-Boot fdt.
160 /examples Example code for standalone applications, etc.
161 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
162 /include Header Files
163 /lib Library routines generic to all architectures
164 /Licenses Various license files
166 /post Power On Self Test
167 /scripts Various build scripts and Makefiles
168 /test Various unit test files
169 /tools Tools to build S-Record or U-Boot images, etc.
171 Software Configuration:
172 =======================
174 Configuration is usually done using C preprocessor defines; the
175 rationale behind that is to avoid dead code whenever possible.
177 There are two classes of configuration variables:
179 * Configuration _OPTIONS_:
180 These are selectable by the user and have names beginning with
183 * Configuration _SETTINGS_:
184 These depend on the hardware etc. and should not be meddled with if
185 you don't know what you're doing; they have names beginning with
188 Previously, all configuration was done by hand, which involved creating
189 symbolic links and editing configuration files manually. More recently,
190 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
191 allowing you to use the "make menuconfig" command to configure your
195 Selection of Processor Architecture and Board Type:
196 ---------------------------------------------------
198 For all supported boards there are ready-to-use default
199 configurations available; just type "make <board_name>_defconfig".
201 Example: For a TQM823L module type:
204 make TQM823L_defconfig
206 Note: If you're looking for the default configuration file for a board
207 you're sure used to be there but is now missing, check the file
208 doc/README.scrapyard for a list of no longer supported boards.
213 U-Boot can be built natively to run on a Linux host using the 'sandbox'
214 board. This allows feature development which is not board- or architecture-
215 specific to be undertaken on a native platform. The sandbox is also used to
216 run some of U-Boot's tests.
218 See board/sandbox/README.sandbox for more details.
221 Board Initialisation Flow:
222 --------------------------
224 This is the intended start-up flow for boards. This should apply for both
225 SPL and U-Boot proper (i.e. they both follow the same rules).
227 Note: "SPL" stands for "Secondary Program Loader," which is explained in
228 more detail later in this file.
230 At present, SPL mostly uses a separate code path, but the function names
231 and roles of each function are the same. Some boards or architectures
232 may not conform to this. At least most ARM boards which use
233 CONFIG_SPL_FRAMEWORK conform to this.
235 Execution typically starts with an architecture-specific (and possibly
236 CPU-specific) start.S file, such as:
238 - arch/arm/cpu/armv7/start.S
239 - arch/powerpc/cpu/mpc83xx/start.S
240 - arch/mips/cpu/start.S
242 and so on. From there, three functions are called; the purpose and
243 limitations of each of these functions are described below.
246 - purpose: essential init to permit execution to reach board_init_f()
247 - no global_data or BSS
248 - there is no stack (ARMv7 may have one but it will soon be removed)
249 - must not set up SDRAM or use console
250 - must only do the bare minimum to allow execution to continue to
252 - this is almost never needed
253 - return normally from this function
256 - purpose: set up the machine ready for running board_init_r():
257 i.e. SDRAM and serial UART
258 - global_data is available
260 - BSS is not available, so you cannot use global/static variables,
261 only stack variables and global_data
263 Non-SPL-specific notes:
264 - dram_init() is called to set up DRAM. If already done in SPL this
268 - you can override the entire board_init_f() function with your own
270 - preloader_console_init() can be called here in extremis
271 - should set up SDRAM, and anything needed to make the UART work
272 - these is no need to clear BSS, it will be done by crt0.S
273 - must return normally from this function (don't call board_init_r()
276 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
277 this point the stack and global_data are relocated to below
278 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
282 - purpose: main execution, common code
283 - global_data is available
285 - BSS is available, all static/global variables can be used
286 - execution eventually continues to main_loop()
288 Non-SPL-specific notes:
289 - U-Boot is relocated to the top of memory and is now running from
293 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
294 CONFIG_SPL_STACK_R_ADDR points into SDRAM
295 - preloader_console_init() can be called here - typically this is
296 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
297 spl_board_init() function containing this call
298 - loads U-Boot or (in falcon mode) Linux
302 Configuration Options:
303 ----------------------
305 Configuration depends on the combination of board and CPU type; all
306 such information is kept in a configuration file
307 "include/configs/<board_name>.h".
309 Example: For a TQM823L module, all configuration settings are in
310 "include/configs/TQM823L.h".
313 Many of the options are named exactly as the corresponding Linux
314 kernel configuration options. The intention is to make it easier to
315 build a config tool - later.
318 The following options need to be configured:
320 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
322 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
324 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
325 Define exactly one, e.g. CONFIG_ATSTK1002
327 - CPU Module Type: (if CONFIG_COGENT is defined)
328 Define exactly one of
330 --- FIXME --- not tested yet:
331 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
332 CONFIG_CMA287_23, CONFIG_CMA287_50
334 - Motherboard Type: (if CONFIG_COGENT is defined)
335 Define exactly one of
336 CONFIG_CMA101, CONFIG_CMA102
338 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
339 Define one or more of
342 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
343 Define one or more of
344 CONFIG_LCD_HEARTBEAT - update a character position on
345 the LCD display every second with
348 - Marvell Family Member
349 CONFIG_SYS_MVFS - define it if you want to enable
350 multiple fs option at one time
351 for marvell soc family
353 - 8xx CPU Options: (if using an MPC8xx CPU)
354 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
355 get_gclk_freq() cannot work
356 e.g. if there is no 32KHz
357 reference PIT/RTC clock
358 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
361 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
362 CONFIG_SYS_8xx_CPUCLK_MIN
363 CONFIG_SYS_8xx_CPUCLK_MAX
364 CONFIG_8xx_CPUCLK_DEFAULT
365 See doc/README.MPC866
367 CONFIG_SYS_MEASURE_CPUCLK
369 Define this to measure the actual CPU clock instead
370 of relying on the correctness of the configured
371 values. Mostly useful for board bringup to make sure
372 the PLL is locked at the intended frequency. Note
373 that this requires a (stable) reference clock (32 kHz
374 RTC clock or CONFIG_SYS_8XX_XIN)
376 CONFIG_SYS_DELAYED_ICACHE
378 Define this option if you want to enable the
379 ICache only when Code runs from RAM.
384 Specifies that the core is a 64-bit PowerPC implementation (implements
385 the "64" category of the Power ISA). This is necessary for ePAPR
386 compliance, among other possible reasons.
388 CONFIG_SYS_FSL_TBCLK_DIV
390 Defines the core time base clock divider ratio compared to the
391 system clock. On most PQ3 devices this is 8, on newer QorIQ
392 devices it can be 16 or 32. The ratio varies from SoC to Soc.
394 CONFIG_SYS_FSL_PCIE_COMPAT
396 Defines the string to utilize when trying to match PCIe device
397 tree nodes for the given platform.
399 CONFIG_SYS_PPC_E500_DEBUG_TLB
401 Enables a temporary TLB entry to be used during boot to work
402 around limitations in e500v1 and e500v2 external debugger
403 support. This reduces the portions of the boot code where
404 breakpoints and single stepping do not work. The value of this
405 symbol should be set to the TLB1 entry to be used for this
408 CONFIG_SYS_FSL_ERRATUM_A004510
410 Enables a workaround for erratum A004510. If set,
411 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
414 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
415 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
417 Defines one or two SoC revisions (low 8 bits of SVR)
418 for which the A004510 workaround should be applied.
420 The rest of SVR is either not relevant to the decision
421 of whether the erratum is present (e.g. p2040 versus
422 p2041) or is implied by the build target, which controls
423 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
425 See Freescale App Note 4493 for more information about
428 CONFIG_A003399_NOR_WORKAROUND
429 Enables a workaround for IFC erratum A003399. It is only
430 required during NOR boot.
432 CONFIG_A008044_WORKAROUND
433 Enables a workaround for T1040/T1042 erratum A008044. It is only
434 required during NAND boot and valid for Rev 1.0 SoC revision
436 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
438 This is the value to write into CCSR offset 0x18600
439 according to the A004510 workaround.
441 CONFIG_SYS_FSL_DSP_DDR_ADDR
442 This value denotes start offset of DDR memory which is
443 connected exclusively to the DSP cores.
445 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
446 This value denotes start offset of M2 memory
447 which is directly connected to the DSP core.
449 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
450 This value denotes start offset of M3 memory which is directly
451 connected to the DSP core.
453 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
454 This value denotes start offset of DSP CCSR space.
456 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
457 Single Source Clock is clocking mode present in some of FSL SoC's.
458 In this mode, a single differential clock is used to supply
459 clocks to the sysclock, ddrclock and usbclock.
461 CONFIG_SYS_CPC_REINIT_F
462 This CONFIG is defined when the CPC is configured as SRAM at the
463 time of U-Boot entry and is required to be re-initialized.
466 Indicates this SoC supports deep sleep feature. If deep sleep is
467 supported, core will start to execute uboot when wakes up.
469 - Generic CPU options:
470 CONFIG_SYS_GENERIC_GLOBAL_DATA
471 Defines global data is initialized in generic board board_init_f().
472 If this macro is defined, global data is created and cleared in
473 generic board board_init_f(). Without this macro, architecture/board
474 should initialize global data before calling board_init_f().
476 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
478 Defines the endianess of the CPU. Implementation of those
479 values is arch specific.
482 Freescale DDR driver in use. This type of DDR controller is
483 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
486 CONFIG_SYS_FSL_DDR_ADDR
487 Freescale DDR memory-mapped register base.
489 CONFIG_SYS_FSL_DDR_EMU
490 Specify emulator support for DDR. Some DDR features such as
491 deskew training are not available.
493 CONFIG_SYS_FSL_DDRC_GEN1
494 Freescale DDR1 controller.
496 CONFIG_SYS_FSL_DDRC_GEN2
497 Freescale DDR2 controller.
499 CONFIG_SYS_FSL_DDRC_GEN3
500 Freescale DDR3 controller.
502 CONFIG_SYS_FSL_DDRC_GEN4
503 Freescale DDR4 controller.
505 CONFIG_SYS_FSL_DDRC_ARM_GEN3
506 Freescale DDR3 controller for ARM-based SoCs.
509 Board config to use DDR1. It can be enabled for SoCs with
510 Freescale DDR1 or DDR2 controllers, depending on the board
514 Board config to use DDR2. It can be enabled for SoCs with
515 Freescale DDR2 or DDR3 controllers, depending on the board
519 Board config to use DDR3. It can be enabled for SoCs with
520 Freescale DDR3 or DDR3L controllers.
523 Board config to use DDR3L. It can be enabled for SoCs with
527 Board config to use DDR4. It can be enabled for SoCs with
530 CONFIG_SYS_FSL_IFC_BE
531 Defines the IFC controller register space as Big Endian
533 CONFIG_SYS_FSL_IFC_LE
534 Defines the IFC controller register space as Little Endian
536 CONFIG_SYS_FSL_PBL_PBI
537 It enables addition of RCW (Power on reset configuration) in built image.
538 Please refer doc/README.pblimage for more details
540 CONFIG_SYS_FSL_PBL_RCW
541 It adds PBI(pre-boot instructions) commands in u-boot build image.
542 PBI commands can be used to configure SoC before it starts the execution.
543 Please refer doc/README.pblimage for more details
546 It adds a target to create boot binary having SPL binary in PBI format
547 concatenated with u-boot binary.
549 CONFIG_SYS_FSL_DDR_BE
550 Defines the DDR controller register space as Big Endian
552 CONFIG_SYS_FSL_DDR_LE
553 Defines the DDR controller register space as Little Endian
555 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
556 Physical address from the view of DDR controllers. It is the
557 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
558 it could be different for ARM SoCs.
560 CONFIG_SYS_FSL_DDR_INTLV_256B
561 DDR controller interleaving on 256-byte. This is a special
562 interleaving mode, handled by Dickens for Freescale layerscape
565 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
566 Number of controllers used as main memory.
568 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
569 Number of controllers used for other than main memory.
571 CONFIG_SYS_FSL_HAS_DP_DDR
572 Defines the SoC has DP-DDR used for DPAA.
574 CONFIG_SYS_FSL_SEC_BE
575 Defines the SEC controller register space as Big Endian
577 CONFIG_SYS_FSL_SEC_LE
578 Defines the SEC controller register space as Little Endian
580 - Intel Monahans options:
581 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
583 Defines the Monahans run mode to oscillator
584 ratio. Valid values are 8, 16, 24, 31. The core
585 frequency is this value multiplied by 13 MHz.
587 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
589 Defines the Monahans turbo mode to oscillator
590 ratio. Valid values are 1 (default if undefined) and
591 2. The core frequency as calculated above is multiplied
595 CONFIG_SYS_INIT_SP_OFFSET
597 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
598 pointer. This is needed for the temporary stack before
601 CONFIG_SYS_MIPS_CACHE_MODE
603 Cache operation mode for the MIPS CPU.
604 See also arch/mips/include/asm/mipsregs.h.
606 CONF_CM_CACHABLE_NO_WA
609 CONF_CM_CACHABLE_NONCOHERENT
613 CONF_CM_CACHABLE_ACCELERATED
615 CONFIG_SYS_XWAY_EBU_BOOTCFG
617 Special option for Lantiq XWAY SoCs for booting from NOR flash.
618 See also arch/mips/cpu/mips32/start.S.
620 CONFIG_XWAY_SWAP_BYTES
622 Enable compilation of tools/xway-swap-bytes needed for Lantiq
623 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
624 be swapped if a flash programmer is used.
627 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
629 Select high exception vectors of the ARM core, e.g., do not
630 clear the V bit of the c1 register of CP15.
632 CONFIG_SYS_THUMB_BUILD
634 Use this flag to build U-Boot using the Thumb instruction
635 set for ARM architectures. Thumb instruction set provides
636 better code density. For ARM architectures that support
637 Thumb2 this flag will result in Thumb2 code generated by
640 CONFIG_ARM_ERRATA_716044
641 CONFIG_ARM_ERRATA_742230
642 CONFIG_ARM_ERRATA_743622
643 CONFIG_ARM_ERRATA_751472
644 CONFIG_ARM_ERRATA_761320
645 CONFIG_ARM_ERRATA_773022
646 CONFIG_ARM_ERRATA_774769
647 CONFIG_ARM_ERRATA_794072
649 If set, the workarounds for these ARM errata are applied early
650 during U-Boot startup. Note that these options force the
651 workarounds to be applied; no CPU-type/version detection
652 exists, unlike the similar options in the Linux kernel. Do not
653 set these options unless they apply!
656 Generic timer clock source frequency.
658 COUNTER_FREQUENCY_REAL
659 Generic timer clock source frequency if the real clock is
660 different from COUNTER_FREQUENCY, and can only be determined
663 NOTE: The following can be machine specific errata. These
664 do have ability to provide rudimentary version and machine
665 specific checks, but expect no product checks.
666 CONFIG_ARM_ERRATA_430973
667 CONFIG_ARM_ERRATA_454179
668 CONFIG_ARM_ERRATA_621766
669 CONFIG_ARM_ERRATA_798870
670 CONFIG_ARM_ERRATA_801819
673 CONFIG_TEGRA_SUPPORT_NON_SECURE
675 Support executing U-Boot in non-secure (NS) mode. Certain
676 impossible actions will be skipped if the CPU is in NS mode,
677 such as ARM architectural timer initialization.
679 - Linux Kernel Interface:
682 U-Boot stores all clock information in Hz
683 internally. For binary compatibility with older Linux
684 kernels (which expect the clocks passed in the
685 bd_info data to be in MHz) the environment variable
686 "clocks_in_mhz" can be defined so that U-Boot
687 converts clock data to MHZ before passing it to the
689 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
690 "clocks_in_mhz=1" is automatically included in the
693 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
695 When transferring memsize parameter to Linux, some versions
696 expect it to be in bytes, others in MB.
697 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
701 New kernel versions are expecting firmware settings to be
702 passed using flattened device trees (based on open firmware
706 * New libfdt-based support
707 * Adds the "fdt" command
708 * The bootm command automatically updates the fdt
710 OF_CPU - The proper name of the cpus node (only required for
711 MPC512X and MPC5xxx based boards).
712 OF_SOC - The proper name of the soc node (only required for
713 MPC512X and MPC5xxx based boards).
714 OF_TBCLK - The timebase frequency.
715 OF_STDOUT_PATH - The path to the console device
717 boards with QUICC Engines require OF_QE to set UCC MAC
720 CONFIG_OF_BOARD_SETUP
722 Board code has addition modification that it wants to make
723 to the flat device tree before handing it off to the kernel
725 CONFIG_OF_SYSTEM_SETUP
727 Other code has addition modification that it wants to make
728 to the flat device tree before handing it off to the kernel.
729 This causes ft_system_setup() to be called before booting
734 This define fills in the correct boot CPU in the boot
735 param header, the default value is zero if undefined.
739 U-Boot can detect if an IDE device is present or not.
740 If not, and this new config option is activated, U-Boot
741 removes the ATA node from the DTS before booting Linux,
742 so the Linux IDE driver does not probe the device and
743 crash. This is needed for buggy hardware (uc101) where
744 no pull down resistor is connected to the signal IDE5V_DD7.
746 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
748 This setting is mandatory for all boards that have only one
749 machine type and must be used to specify the machine type
750 number as it appears in the ARM machine registry
751 (see http://www.arm.linux.org.uk/developer/machines/).
752 Only boards that have multiple machine types supported
753 in a single configuration file and the machine type is
754 runtime discoverable, do not have to use this setting.
756 - vxWorks boot parameters:
758 bootvx constructs a valid bootline using the following
759 environments variables: bootdev, bootfile, ipaddr, netmask,
760 serverip, gatewayip, hostname, othbootargs.
761 It loads the vxWorks image pointed bootfile.
763 Note: If a "bootargs" environment is defined, it will overwride
764 the defaults discussed just above.
766 - Cache Configuration:
767 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
768 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
769 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
771 - Cache Configuration for ARM:
772 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
774 CONFIG_SYS_PL310_BASE - Physical base address of PL310
775 controller register space
780 Define this if you want support for Amba PrimeCell PL010 UARTs.
784 Define this if you want support for Amba PrimeCell PL011 UARTs.
788 If you have Amba PrimeCell PL011 UARTs, set this variable to
789 the clock speed of the UARTs.
793 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
794 define this to a list of base addresses for each (supported)
795 port. See e.g. include/configs/versatile.h
797 CONFIG_SERIAL_HW_FLOW_CONTROL
799 Define this variable to enable hw flow control in serial driver.
800 Current user of this option is drivers/serial/nsl16550.c driver
803 Depending on board, define exactly one serial port
804 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
805 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
806 console by defining CONFIG_8xx_CONS_NONE
808 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
809 port routines must be defined elsewhere
810 (i.e. serial_init(), serial_getc(), ...)
813 Enables console device for a color framebuffer. Needs following
814 defines (cf. smiLynxEM, i8042)
815 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
817 VIDEO_HW_RECTFILL graphic chip supports
820 VIDEO_HW_BITBLT graphic chip supports
821 bit-blit (cf. smiLynxEM)
822 VIDEO_VISIBLE_COLS visible pixel columns
824 VIDEO_VISIBLE_ROWS visible pixel rows
825 VIDEO_PIXEL_SIZE bytes per pixel
826 VIDEO_DATA_FORMAT graphic data format
827 (0-5, cf. cfb_console.c)
828 VIDEO_FB_ADRS framebuffer address
829 VIDEO_KBD_INIT_FCT keyboard int fct
830 (i.e. rx51_kp_init())
831 VIDEO_TSTC_FCT test char fct
833 VIDEO_GETC_FCT get char fct
835 CONFIG_VIDEO_LOGO display Linux logo in
837 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
838 linux_logo.h for logo.
839 Requires CONFIG_VIDEO_LOGO
840 CONFIG_CONSOLE_EXTRA_INFO
841 additional board info beside
843 CONFIG_HIDE_LOGO_VERSION
844 do not display bootloader
847 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
848 a limited number of ANSI escape sequences (cursor control,
849 erase functions and limited graphics rendition control).
851 When CONFIG_CFB_CONSOLE is defined, video console is
852 default i/o. Serial console can be forced with
853 environment 'console=serial'.
855 When CONFIG_SILENT_CONSOLE is defined, all console
856 messages (by U-Boot and Linux!) can be silenced with
857 the "silent" environment variable. See
858 doc/README.silent for more information.
860 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
862 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
866 CONFIG_BAUDRATE - in bps
867 Select one of the baudrates listed in
868 CONFIG_SYS_BAUDRATE_TABLE, see below.
869 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
871 - Console Rx buffer length
872 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
873 the maximum receive buffer length for the SMC.
874 This option is actual only for 82xx and 8xx possible.
875 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
876 must be defined, to setup the maximum idle timeout for
879 - Pre-Console Buffer:
880 Prior to the console being initialised (i.e. serial UART
881 initialised etc) all console output is silently discarded.
882 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
883 buffer any console messages prior to the console being
884 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
885 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
886 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
887 bytes are output before the console is initialised, the
888 earlier bytes are discarded.
890 Note that when printing the buffer a copy is made on the
891 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
893 'Sane' compilers will generate smaller code if
894 CONFIG_PRE_CON_BUF_SZ is a power of 2
898 Only needed when CONFIG_BOOTDELAY is enabled;
899 define a command string that is automatically executed
900 when no character is read on the console interface
901 within "Boot Delay" after reset.
904 This can be used to pass arguments to the bootm
905 command. The value of CONFIG_BOOTARGS goes into the
906 environment value "bootargs".
908 CONFIG_RAMBOOT and CONFIG_NFSBOOT
909 The value of these goes into the environment as
910 "ramboot" and "nfsboot" respectively, and can be used
911 as a convenience, when switching between booting from
915 CONFIG_BOOTCOUNT_LIMIT
916 Implements a mechanism for detecting a repeating reboot
918 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
921 If no softreset save registers are found on the hardware
922 "bootcount" is stored in the environment. To prevent a
923 saveenv on all reboots, the environment variable
924 "upgrade_available" is used. If "upgrade_available" is
925 0, "bootcount" is always 0, if "upgrade_available" is
926 1 "bootcount" is incremented in the environment.
927 So the Userspace Applikation must set the "upgrade_available"
928 and "bootcount" variable to 0, if a boot was successfully.
933 When this option is #defined, the existence of the
934 environment variable "preboot" will be checked
935 immediately before starting the CONFIG_BOOTDELAY
936 countdown and/or running the auto-boot command resp.
937 entering interactive mode.
939 This feature is especially useful when "preboot" is
940 automatically generated or modified. For an example
941 see the LWMON board specific code: here "preboot" is
942 modified when the user holds down a certain
943 combination of keys on the (special) keyboard when
946 - Serial Download Echo Mode:
948 If defined to 1, all characters received during a
949 serial download (using the "loads" command) are
950 echoed back. This might be needed by some terminal
951 emulations (like "cu"), but may as well just take
952 time on others. This setting #define's the initial
953 value of the "loads_echo" environment variable.
955 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
957 Select one of the baudrates listed in
958 CONFIG_SYS_BAUDRATE_TABLE, see below.
961 Monitor commands can be included or excluded
962 from the build by using the #include files
963 <config_cmd_all.h> and #undef'ing unwanted
964 commands, or adding #define's for wanted commands.
966 The default command configuration includes all commands
967 except those marked below with a "*".
969 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
970 CONFIG_CMD_ASKENV * ask for env variable
971 CONFIG_CMD_BDI bdinfo
972 CONFIG_CMD_BEDBUG * Include BedBug Debugger
973 CONFIG_CMD_BMP * BMP support
974 CONFIG_CMD_BSP * Board specific commands
975 CONFIG_CMD_BOOTD bootd
976 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
977 CONFIG_CMD_CACHE * icache, dcache
978 CONFIG_CMD_CLK * clock command support
979 CONFIG_CMD_CONSOLE coninfo
980 CONFIG_CMD_CRC32 * crc32
981 CONFIG_CMD_DATE * support for RTC, date/time...
982 CONFIG_CMD_DHCP * DHCP support
983 CONFIG_CMD_DIAG * Diagnostics
984 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
985 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
986 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
987 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
988 CONFIG_CMD_DTT * Digital Therm and Thermostat
989 CONFIG_CMD_ECHO echo arguments
990 CONFIG_CMD_EDITENV edit env variable
991 CONFIG_CMD_EEPROM * EEPROM read/write support
992 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
993 CONFIG_CMD_ELF * bootelf, bootvx
994 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
995 CONFIG_CMD_ENV_FLAGS * display details about env flags
996 CONFIG_CMD_ENV_EXISTS * check existence of env variable
997 CONFIG_CMD_EXPORTENV * export the environment
998 CONFIG_CMD_EXT2 * ext2 command support
999 CONFIG_CMD_EXT4 * ext4 command support
1000 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1001 that work for multiple fs types
1002 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1003 CONFIG_CMD_SAVEENV saveenv
1004 CONFIG_CMD_FDC * Floppy Disk Support
1005 CONFIG_CMD_FAT * FAT command support
1006 CONFIG_CMD_FLASH flinfo, erase, protect
1007 CONFIG_CMD_FPGA FPGA device initialization support
1008 CONFIG_CMD_FUSE * Device fuse support
1009 CONFIG_CMD_GETTIME * Get time since boot
1010 CONFIG_CMD_GO * the 'go' command (exec code)
1011 CONFIG_CMD_GREPENV * search environment
1012 CONFIG_CMD_HASH * calculate hash / digest
1013 CONFIG_CMD_I2C * I2C serial bus support
1014 CONFIG_CMD_IDE * IDE harddisk support
1015 CONFIG_CMD_IMI iminfo
1016 CONFIG_CMD_IMLS List all images found in NOR flash
1017 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1018 CONFIG_CMD_IMMAP * IMMR dump support
1019 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1020 CONFIG_CMD_IMPORTENV * import an environment
1021 CONFIG_CMD_INI * import data from an ini file into the env
1022 CONFIG_CMD_IRQ * irqinfo
1023 CONFIG_CMD_ITEST Integer/string test of 2 values
1024 CONFIG_CMD_JFFS2 * JFFS2 Support
1025 CONFIG_CMD_KGDB * kgdb
1026 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1027 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1029 CONFIG_CMD_LOADB loadb
1030 CONFIG_CMD_LOADS loads
1031 CONFIG_CMD_MD5SUM * print md5 message digest
1032 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1033 CONFIG_CMD_MEMINFO * Display detailed memory information
1034 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1036 CONFIG_CMD_MEMTEST * mtest
1037 CONFIG_CMD_MISC Misc functions like sleep etc
1038 CONFIG_CMD_MMC * MMC memory mapped support
1039 CONFIG_CMD_MII * MII utility commands
1040 CONFIG_CMD_MTDPARTS * MTD partition support
1041 CONFIG_CMD_NAND * NAND support
1042 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1043 CONFIG_CMD_NFS NFS support
1044 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1045 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1046 CONFIG_CMD_PCI * pciinfo
1047 CONFIG_CMD_PCMCIA * PCMCIA support
1048 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1050 CONFIG_CMD_PORTIO * Port I/O
1051 CONFIG_CMD_READ * Read raw data from partition
1052 CONFIG_CMD_REGINFO * Register dump
1053 CONFIG_CMD_RUN run command in env variable
1054 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1055 CONFIG_CMD_SAVES * save S record dump
1056 CONFIG_SCSI * SCSI Support
1057 CONFIG_CMD_SDRAM * print SDRAM configuration information
1058 (requires CONFIG_CMD_I2C)
1059 CONFIG_CMD_SETGETDCR Support for DCR Register access
1061 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1062 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1063 (requires CONFIG_CMD_MEMORY)
1064 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1065 CONFIG_CMD_SOURCE "source" command Support
1066 CONFIG_CMD_SPI * SPI serial bus support
1067 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1068 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1069 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1070 CONFIG_CMD_TIMER * access to the system tick timer
1071 CONFIG_CMD_USB * USB support
1072 CONFIG_CMD_CDP * Cisco Discover Protocol support
1073 CONFIG_CMD_MFSL * Microblaze FSL support
1074 CONFIG_CMD_XIMG Load part of Multi Image
1075 CONFIG_CMD_UUID * Generate random UUID or GUID string
1077 EXAMPLE: If you want all functions except of network
1078 support you can write:
1080 #include "config_cmd_all.h"
1081 #undef CONFIG_CMD_NET
1084 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1086 Note: Don't enable the "icache" and "dcache" commands
1087 (configuration option CONFIG_CMD_CACHE) unless you know
1088 what you (and your U-Boot users) are doing. Data
1089 cache cannot be enabled on systems like the 8xx or
1090 8260 (where accesses to the IMMR region must be
1091 uncached), and it cannot be disabled on all other
1092 systems where we (mis-) use the data cache to hold an
1093 initial stack and some data.
1096 XXX - this list needs to get updated!
1098 - Removal of commands
1099 If no commands are needed to boot, you can disable
1100 CONFIG_CMDLINE to remove them. In this case, the command line
1101 will not be available, and when U-Boot wants to execute the
1102 boot command (on start-up) it will call board_run_command()
1103 instead. This can reduce image size significantly for very
1104 simple boot procedures.
1106 - Regular expression support:
1108 If this variable is defined, U-Boot is linked against
1109 the SLRE (Super Light Regular Expression) library,
1110 which adds regex support to some commands, as for
1111 example "env grep" and "setexpr".
1115 If this variable is defined, U-Boot will use a device tree
1116 to configure its devices, instead of relying on statically
1117 compiled #defines in the board file. This option is
1118 experimental and only available on a few boards. The device
1119 tree is available in the global data as gd->fdt_blob.
1121 U-Boot needs to get its device tree from somewhere. This can
1122 be done using one of the two options below:
1125 If this variable is defined, U-Boot will embed a device tree
1126 binary in its image. This device tree file should be in the
1127 board directory and called <soc>-<board>.dts. The binary file
1128 is then picked up in board_init_f() and made available through
1129 the global data structure as gd->blob.
1132 If this variable is defined, U-Boot will build a device tree
1133 binary. It will be called u-boot.dtb. Architecture-specific
1134 code will locate it at run-time. Generally this works by:
1136 cat u-boot.bin u-boot.dtb >image.bin
1138 and in fact, U-Boot does this for you, creating a file called
1139 u-boot-dtb.bin which is useful in the common case. You can
1140 still use the individual files if you need something more
1145 If this variable is defined, it enables watchdog
1146 support for the SoC. There must be support in the SoC
1147 specific code for a watchdog. For the 8xx and 8260
1148 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1149 register. When supported for a specific SoC is
1150 available, then no further board specific code should
1151 be needed to use it.
1154 When using a watchdog circuitry external to the used
1155 SoC, then define this variable and provide board
1156 specific code for the "hw_watchdog_reset" function.
1158 CONFIG_AT91_HW_WDT_TIMEOUT
1159 specify the timeout in seconds. default 2 seconds.
1162 CONFIG_VERSION_VARIABLE
1163 If this variable is defined, an environment variable
1164 named "ver" is created by U-Boot showing the U-Boot
1165 version as printed by the "version" command.
1166 Any change to this variable will be reverted at the
1171 When CONFIG_CMD_DATE is selected, the type of the RTC
1172 has to be selected, too. Define exactly one of the
1175 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1176 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1177 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1178 CONFIG_RTC_MC146818 - use MC146818 RTC
1179 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1180 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1181 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1182 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1183 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1184 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1185 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1186 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1187 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1190 Note that if the RTC uses I2C, then the I2C interface
1191 must also be configured. See I2C Support, below.
1194 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1196 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1197 chip-ngpio pairs that tell the PCA953X driver the number of
1198 pins supported by a particular chip.
1200 Note that if the GPIO device uses I2C, then the I2C interface
1201 must also be configured. See I2C Support, below.
1204 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1205 accesses and can checksum them or write a list of them out
1206 to memory. See the 'iotrace' command for details. This is
1207 useful for testing device drivers since it can confirm that
1208 the driver behaves the same way before and after a code
1209 change. Currently this is supported on sandbox and arm. To
1210 add support for your architecture, add '#include <iotrace.h>'
1211 to the bottom of arch/<arch>/include/asm/io.h and test.
1213 Example output from the 'iotrace stats' command is below.
1214 Note that if the trace buffer is exhausted, the checksum will
1215 still continue to operate.
1218 Start: 10000000 (buffer start address)
1219 Size: 00010000 (buffer size)
1220 Offset: 00000120 (current buffer offset)
1221 Output: 10000120 (start + offset)
1222 Count: 00000018 (number of trace records)
1223 CRC32: 9526fb66 (CRC32 of all trace records)
1225 - Timestamp Support:
1227 When CONFIG_TIMESTAMP is selected, the timestamp
1228 (date and time) of an image is printed by image
1229 commands like bootm or iminfo. This option is
1230 automatically enabled when you select CONFIG_CMD_DATE .
1232 - Partition Labels (disklabels) Supported:
1233 Zero or more of the following:
1234 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1235 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1236 Intel architecture, USB sticks, etc.
1237 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1238 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1239 bootloader. Note 2TB partition limit; see
1241 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1243 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1244 CONFIG_SCSI) you must configure support for at
1245 least one non-MTD partition type as well.
1248 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1249 board configurations files but used nowhere!
1251 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1252 be performed by calling the function
1253 ide_set_reset(int reset)
1254 which has to be defined in a board specific file
1259 Set this to enable ATAPI support.
1264 Set this to enable support for disks larger than 137GB
1265 Also look at CONFIG_SYS_64BIT_LBA.
1266 Whithout these , LBA48 support uses 32bit variables and will 'only'
1267 support disks up to 2.1TB.
1269 CONFIG_SYS_64BIT_LBA:
1270 When enabled, makes the IDE subsystem use 64bit sector addresses.
1274 At the moment only there is only support for the
1275 SYM53C8XX SCSI controller; define
1276 CONFIG_SCSI_SYM53C8XX to enable it.
1278 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1279 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1280 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1281 maximum numbers of LUNs, SCSI ID's and target
1283 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1285 The environment variable 'scsidevs' is set to the number of
1286 SCSI devices found during the last scan.
1288 - NETWORK Support (PCI):
1290 Support for Intel 8254x/8257x gigabit chips.
1293 Utility code for direct access to the SPI bus on Intel 8257x.
1294 This does not do anything useful unless you set at least one
1295 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1297 CONFIG_E1000_SPI_GENERIC
1298 Allow generic access to the SPI bus on the Intel 8257x, for
1299 example with the "sspi" command.
1302 Management command for E1000 devices. When used on devices
1303 with SPI support you can reprogram the EEPROM from U-Boot.
1306 Support for Intel 82557/82559/82559ER chips.
1307 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1308 write routine for first time initialisation.
1311 Support for Digital 2114x chips.
1312 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1313 modem chip initialisation (KS8761/QS6611).
1316 Support for National dp83815 chips.
1319 Support for National dp8382[01] gigabit chips.
1321 - NETWORK Support (other):
1323 CONFIG_DRIVER_AT91EMAC
1324 Support for AT91RM9200 EMAC.
1327 Define this to use reduced MII inteface
1329 CONFIG_DRIVER_AT91EMAC_QUIET
1330 If this defined, the driver is quiet.
1331 The driver doen't show link status messages.
1333 CONFIG_CALXEDA_XGMAC
1334 Support for the Calxeda XGMAC device
1337 Support for SMSC's LAN91C96 chips.
1339 CONFIG_LAN91C96_BASE
1340 Define this to hold the physical address
1341 of the LAN91C96's I/O space
1343 CONFIG_LAN91C96_USE_32_BIT
1344 Define this to enable 32 bit addressing
1347 Support for SMSC's LAN91C111 chip
1349 CONFIG_SMC91111_BASE
1350 Define this to hold the physical address
1351 of the device (I/O space)
1353 CONFIG_SMC_USE_32_BIT
1354 Define this if data bus is 32 bits
1356 CONFIG_SMC_USE_IOFUNCS
1357 Define this to use i/o functions instead of macros
1358 (some hardware wont work with macros)
1360 CONFIG_DRIVER_TI_EMAC
1361 Support for davinci emac
1363 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1364 Define this if you have more then 3 PHYs.
1367 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1369 CONFIG_FTGMAC100_EGIGA
1370 Define this to use GE link update with gigabit PHY.
1371 Define this if FTGMAC100 is connected to gigabit PHY.
1372 If your system has 10/100 PHY only, it might not occur
1373 wrong behavior. Because PHY usually return timeout or
1374 useless data when polling gigabit status and gigabit
1375 control registers. This behavior won't affect the
1376 correctnessof 10/100 link speed update.
1379 Support for SMSC's LAN911x and LAN921x chips
1382 Define this to hold the physical address
1383 of the device (I/O space)
1385 CONFIG_SMC911X_32_BIT
1386 Define this if data bus is 32 bits
1388 CONFIG_SMC911X_16_BIT
1389 Define this if data bus is 16 bits. If your processor
1390 automatically converts one 32 bit word to two 16 bit
1391 words you may also try CONFIG_SMC911X_32_BIT.
1394 Support for Renesas on-chip Ethernet controller
1396 CONFIG_SH_ETHER_USE_PORT
1397 Define the number of ports to be used
1399 CONFIG_SH_ETHER_PHY_ADDR
1400 Define the ETH PHY's address
1402 CONFIG_SH_ETHER_CACHE_WRITEBACK
1403 If this option is set, the driver enables cache flush.
1407 Support for PWM modul on the imx6.
1411 Support TPM devices.
1413 CONFIG_TPM_TIS_INFINEON
1414 Support for Infineon i2c bus TPM devices. Only one device
1415 per system is supported at this time.
1417 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1418 Define the burst count bytes upper limit
1421 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1423 CONFIG_TPM_ST33ZP24_I2C
1424 Support for STMicroelectronics ST33ZP24 I2C devices.
1425 Requires TPM_ST33ZP24 and I2C.
1427 CONFIG_TPM_ST33ZP24_SPI
1428 Support for STMicroelectronics ST33ZP24 SPI devices.
1429 Requires TPM_ST33ZP24 and SPI.
1431 CONFIG_TPM_ATMEL_TWI
1432 Support for Atmel TWI TPM device. Requires I2C support.
1435 Support for generic parallel port TPM devices. Only one device
1436 per system is supported at this time.
1438 CONFIG_TPM_TIS_BASE_ADDRESS
1439 Base address where the generic TPM device is mapped
1440 to. Contemporary x86 systems usually map it at
1444 Add tpm monitor functions.
1445 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1446 provides monitor access to authorized functions.
1449 Define this to enable the TPM support library which provides
1450 functional interfaces to some TPM commands.
1451 Requires support for a TPM device.
1453 CONFIG_TPM_AUTH_SESSIONS
1454 Define this to enable authorized functions in the TPM library.
1455 Requires CONFIG_TPM and CONFIG_SHA1.
1458 At the moment only the UHCI host controller is
1459 supported (PIP405, MIP405, MPC5200); define
1460 CONFIG_USB_UHCI to enable it.
1461 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1462 and define CONFIG_USB_STORAGE to enable the USB
1465 Supported are USB Keyboards and USB Floppy drives
1467 MPC5200 USB requires additional defines:
1469 for 528 MHz Clock: 0x0001bbbb
1473 for differential drivers: 0x00001000
1474 for single ended drivers: 0x00005000
1475 for differential drivers on PSC3: 0x00000100
1476 for single ended drivers on PSC3: 0x00004100
1477 CONFIG_SYS_USB_EVENT_POLL
1478 May be defined to allow interrupt polling
1479 instead of using asynchronous interrupts
1481 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1482 txfilltuning field in the EHCI controller on reset.
1484 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1485 HW module registers.
1488 Define the below if you wish to use the USB console.
1489 Once firmware is rebuilt from a serial console issue the
1490 command "setenv stdin usbtty; setenv stdout usbtty" and
1491 attach your USB cable. The Unix command "dmesg" should print
1492 it has found a new device. The environment variable usbtty
1493 can be set to gserial or cdc_acm to enable your device to
1494 appear to a USB host as a Linux gserial device or a
1495 Common Device Class Abstract Control Model serial device.
1496 If you select usbtty = gserial you should be able to enumerate
1498 # modprobe usbserial vendor=0xVendorID product=0xProductID
1499 else if using cdc_acm, simply setting the environment
1500 variable usbtty to be cdc_acm should suffice. The following
1501 might be defined in YourBoardName.h
1504 Define this to build a UDC device
1507 Define this to have a tty type of device available to
1508 talk to the UDC device
1511 Define this to enable the high speed support for usb
1512 device and usbtty. If this feature is enabled, a routine
1513 int is_usbd_high_speed(void)
1514 also needs to be defined by the driver to dynamically poll
1515 whether the enumeration has succeded at high speed or full
1518 CONFIG_SYS_CONSOLE_IS_IN_ENV
1519 Define this if you want stdin, stdout &/or stderr to
1523 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1524 Derive USB clock from external clock "blah"
1525 - CONFIG_SYS_USB_EXTC_CLK 0x02
1527 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1528 Derive USB clock from brgclk
1529 - CONFIG_SYS_USB_BRG_CLK 0x04
1531 If you have a USB-IF assigned VendorID then you may wish to
1532 define your own vendor specific values either in BoardName.h
1533 or directly in usbd_vendor_info.h. If you don't define
1534 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1535 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1536 should pretend to be a Linux device to it's target host.
1538 CONFIG_USBD_MANUFACTURER
1539 Define this string as the name of your company for
1540 - CONFIG_USBD_MANUFACTURER "my company"
1542 CONFIG_USBD_PRODUCT_NAME
1543 Define this string as the name of your product
1544 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1546 CONFIG_USBD_VENDORID
1547 Define this as your assigned Vendor ID from the USB
1548 Implementors Forum. This *must* be a genuine Vendor ID
1549 to avoid polluting the USB namespace.
1550 - CONFIG_USBD_VENDORID 0xFFFF
1552 CONFIG_USBD_PRODUCTID
1553 Define this as the unique Product ID
1555 - CONFIG_USBD_PRODUCTID 0xFFFF
1557 - ULPI Layer Support:
1558 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1559 the generic ULPI layer. The generic layer accesses the ULPI PHY
1560 via the platform viewport, so you need both the genric layer and
1561 the viewport enabled. Currently only Chipidea/ARC based
1562 viewport is supported.
1563 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1564 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1565 If your ULPI phy needs a different reference clock than the
1566 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1567 the appropriate value in Hz.
1570 The MMC controller on the Intel PXA is supported. To
1571 enable this define CONFIG_MMC. The MMC can be
1572 accessed from the boot prompt by mapping the device
1573 to physical memory similar to flash. Command line is
1574 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1575 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1578 Support for Renesas on-chip MMCIF controller
1580 CONFIG_SH_MMCIF_ADDR
1581 Define the base address of MMCIF registers
1584 Define the clock frequency for MMCIF
1587 Enable the generic MMC driver
1589 CONFIG_SUPPORT_EMMC_BOOT
1590 Enable some additional features of the eMMC boot partitions.
1592 CONFIG_SUPPORT_EMMC_RPMB
1593 Enable the commands for reading, writing and programming the
1594 key for the Replay Protection Memory Block partition in eMMC.
1596 - USB Device Firmware Update (DFU) class support:
1597 CONFIG_USB_FUNCTION_DFU
1598 This enables the USB portion of the DFU USB class
1601 This enables the command "dfu" which is used to have
1602 U-Boot create a DFU class device via USB. This command
1603 requires that the "dfu_alt_info" environment variable be
1604 set and define the alt settings to expose to the host.
1607 This enables support for exposing (e)MMC devices via DFU.
1610 This enables support for exposing NAND devices via DFU.
1613 This enables support for exposing RAM via DFU.
1614 Note: DFU spec refer to non-volatile memory usage, but
1615 allow usages beyond the scope of spec - here RAM usage,
1616 one that would help mostly the developer.
1618 CONFIG_SYS_DFU_DATA_BUF_SIZE
1619 Dfu transfer uses a buffer before writing data to the
1620 raw storage device. Make the size (in bytes) of this buffer
1621 configurable. The size of this buffer is also configurable
1622 through the "dfu_bufsiz" environment variable.
1624 CONFIG_SYS_DFU_MAX_FILE_SIZE
1625 When updating files rather than the raw storage device,
1626 we use a static buffer to copy the file into and then write
1627 the buffer once we've been given the whole file. Define
1628 this to the maximum filesize (in bytes) for the buffer.
1629 Default is 4 MiB if undefined.
1631 DFU_DEFAULT_POLL_TIMEOUT
1632 Poll timeout [ms], is the timeout a device can send to the
1633 host. The host must wait for this timeout before sending
1634 a subsequent DFU_GET_STATUS request to the device.
1636 DFU_MANIFEST_POLL_TIMEOUT
1637 Poll timeout [ms], which the device sends to the host when
1638 entering dfuMANIFEST state. Host waits this timeout, before
1639 sending again an USB request to the device.
1641 - USB Device Android Fastboot support:
1642 CONFIG_USB_FUNCTION_FASTBOOT
1643 This enables the USB part of the fastboot gadget
1646 This enables the command "fastboot" which enables the Android
1647 fastboot mode for the platform's USB device. Fastboot is a USB
1648 protocol for downloading images, flashing and device control
1649 used on Android devices.
1650 See doc/README.android-fastboot for more information.
1652 CONFIG_ANDROID_BOOT_IMAGE
1653 This enables support for booting images which use the Android
1654 image format header.
1656 CONFIG_FASTBOOT_BUF_ADDR
1657 The fastboot protocol requires a large memory buffer for
1658 downloads. Define this to the starting RAM address to use for
1661 CONFIG_FASTBOOT_BUF_SIZE
1662 The fastboot protocol requires a large memory buffer for
1663 downloads. This buffer should be as large as possible for a
1664 platform. Define this to the size available RAM for fastboot.
1666 CONFIG_FASTBOOT_FLASH
1667 The fastboot protocol includes a "flash" command for writing
1668 the downloaded image to a non-volatile storage device. Define
1669 this to enable the "fastboot flash" command.
1671 CONFIG_FASTBOOT_FLASH_MMC_DEV
1672 The fastboot "flash" command requires additional information
1673 regarding the non-volatile storage device. Define this to
1674 the eMMC device that fastboot should use to store the image.
1676 CONFIG_FASTBOOT_GPT_NAME
1677 The fastboot "flash" command supports writing the downloaded
1678 image to the Protective MBR and the Primary GUID Partition
1679 Table. (Additionally, this downloaded image is post-processed
1680 to generate and write the Backup GUID Partition Table.)
1681 This occurs when the specified "partition name" on the
1682 "fastboot flash" command line matches this value.
1683 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1685 - Journaling Flash filesystem support:
1686 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1687 CONFIG_JFFS2_NAND_DEV
1688 Define these for a default partition on a NAND device
1690 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1691 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1692 Define these for a default partition on a NOR device
1694 CONFIG_SYS_JFFS_CUSTOM_PART
1695 Define this to create an own partition. You have to provide a
1696 function struct part_info* jffs2_part_info(int part_num)
1698 If you define only one JFFS2 partition you may also want to
1699 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1700 to disable the command chpart. This is the default when you
1701 have not defined a custom partition
1703 - FAT(File Allocation Table) filesystem write function support:
1706 Define this to enable support for saving memory data as a
1707 file in FAT formatted partition.
1709 This will also enable the command "fatwrite" enabling the
1710 user to write files to FAT.
1712 CBFS (Coreboot Filesystem) support
1715 Define this to enable support for reading from a Coreboot
1716 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1719 - FAT(File Allocation Table) filesystem cluster size:
1720 CONFIG_FS_FAT_MAX_CLUSTSIZE
1722 Define the max cluster size for fat operations else
1723 a default value of 65536 will be defined.
1726 See Kconfig help for available keyboard drivers.
1730 Define this to enable a custom keyboard support.
1731 This simply calls drv_keyboard_init() which must be
1732 defined in your board-specific files. This option is deprecated
1733 and is only used by novena. For new boards, use driver model
1739 Define this to enable video support (for output to
1742 CONFIG_VIDEO_CT69000
1744 Enable Chips & Technologies 69000 Video chip
1746 CONFIG_VIDEO_SMI_LYNXEM
1747 Enable Silicon Motion SMI 712/710/810 Video chip. The
1748 video output is selected via environment 'videoout'
1749 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1752 For the CT69000 and SMI_LYNXEM drivers, videomode is
1753 selected via environment 'videomode'. Two different ways
1755 - "videomode=num" 'num' is a standard LiLo mode numbers.
1756 Following standard modes are supported (* is default):
1758 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1759 -------------+---------------------------------------------
1760 8 bits | 0x301* 0x303 0x305 0x161 0x307
1761 15 bits | 0x310 0x313 0x316 0x162 0x319
1762 16 bits | 0x311 0x314 0x317 0x163 0x31A
1763 24 bits | 0x312 0x315 0x318 ? 0x31B
1764 -------------+---------------------------------------------
1765 (i.e. setenv videomode 317; saveenv; reset;)
1767 - "videomode=bootargs" all the video parameters are parsed
1768 from the bootargs. (See drivers/video/videomodes.c)
1771 CONFIG_VIDEO_SED13806
1772 Enable Epson SED13806 driver. This driver supports 8bpp
1773 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1774 or CONFIG_VIDEO_SED13806_16BPP
1777 Enable the Freescale DIU video driver. Reference boards for
1778 SOCs that have a DIU should define this macro to enable DIU
1779 support, and should also define these other macros:
1785 CONFIG_VIDEO_SW_CURSOR
1786 CONFIG_VGA_AS_SINGLE_DEVICE
1788 CONFIG_VIDEO_BMP_LOGO
1790 The DIU driver will look for the 'video-mode' environment
1791 variable, and if defined, enable the DIU as a console during
1792 boot. See the documentation file doc/README.video for a
1793 description of this variable.
1795 - LCD Support: CONFIG_LCD
1797 Define this to enable LCD support (for output to LCD
1798 display); also select one of the supported displays
1799 by defining one of these:
1803 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1805 CONFIG_NEC_NL6448AC33:
1807 NEC NL6448AC33-18. Active, color, single scan.
1809 CONFIG_NEC_NL6448BC20
1811 NEC NL6448BC20-08. 6.5", 640x480.
1812 Active, color, single scan.
1814 CONFIG_NEC_NL6448BC33_54
1816 NEC NL6448BC33-54. 10.4", 640x480.
1817 Active, color, single scan.
1821 Sharp 320x240. Active, color, single scan.
1822 It isn't 16x9, and I am not sure what it is.
1824 CONFIG_SHARP_LQ64D341
1826 Sharp LQ64D341 display, 640x480.
1827 Active, color, single scan.
1831 HLD1045 display, 640x480.
1832 Active, color, single scan.
1836 Optrex CBL50840-2 NF-FW 99 22 M5
1838 Hitachi LMG6912RPFC-00T
1842 320x240. Black & white.
1844 Normally display is black on white background; define
1845 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1847 CONFIG_LCD_ALIGNMENT
1849 Normally the LCD is page-aligned (typically 4KB). If this is
1850 defined then the LCD will be aligned to this value instead.
1851 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1852 here, since it is cheaper to change data cache settings on
1853 a per-section basis.
1855 CONFIG_CONSOLE_SCROLL_LINES
1857 When the console need to be scrolled, this is the number of
1858 lines to scroll by. It defaults to 1. Increasing this makes
1859 the console jump but can help speed up operation when scrolling
1864 Sometimes, for example if the display is mounted in portrait
1865 mode or even if it's mounted landscape but rotated by 180degree,
1866 we need to rotate our content of the display relative to the
1867 framebuffer, so that user can read the messages which are
1869 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1870 initialized with a given rotation from "vl_rot" out of
1871 "vidinfo_t" which is provided by the board specific code.
1872 The value for vl_rot is coded as following (matching to
1873 fbcon=rotate:<n> linux-kernel commandline):
1874 0 = no rotation respectively 0 degree
1875 1 = 90 degree rotation
1876 2 = 180 degree rotation
1877 3 = 270 degree rotation
1879 If CONFIG_LCD_ROTATION is not defined, the console will be
1880 initialized with 0degree rotation.
1884 Support drawing of RLE8-compressed bitmaps on the LCD.
1888 Enables an 'i2c edid' command which can read EDID
1889 information over I2C from an attached LCD display.
1891 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1893 If this option is set, the environment is checked for
1894 a variable "splashimage". If found, the usual display
1895 of logo, copyright and system information on the LCD
1896 is suppressed and the BMP image at the address
1897 specified in "splashimage" is loaded instead. The
1898 console is redirected to the "nulldev", too. This
1899 allows for a "silent" boot where a splash screen is
1900 loaded very quickly after power-on.
1902 CONFIG_SPLASHIMAGE_GUARD
1904 If this option is set, then U-Boot will prevent the environment
1905 variable "splashimage" from being set to a problematic address
1906 (see doc/README.displaying-bmps).
1907 This option is useful for targets where, due to alignment
1908 restrictions, an improperly aligned BMP image will cause a data
1909 abort. If you think you will not have problems with unaligned
1910 accesses (for example because your toolchain prevents them)
1911 there is no need to set this option.
1913 CONFIG_SPLASH_SCREEN_ALIGN
1915 If this option is set the splash image can be freely positioned
1916 on the screen. Environment variable "splashpos" specifies the
1917 position as "x,y". If a positive number is given it is used as
1918 number of pixel from left/top. If a negative number is given it
1919 is used as number of pixel from right/bottom. You can also
1920 specify 'm' for centering the image.
1923 setenv splashpos m,m
1924 => image at center of screen
1926 setenv splashpos 30,20
1927 => image at x = 30 and y = 20
1929 setenv splashpos -10,m
1930 => vertically centered image
1931 at x = dspWidth - bmpWidth - 9
1933 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1935 If this option is set, additionally to standard BMP
1936 images, gzipped BMP images can be displayed via the
1937 splashscreen support or the bmp command.
1939 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1941 If this option is set, 8-bit RLE compressed BMP images
1942 can be displayed via the splashscreen support or the
1945 - Do compressing for memory range:
1948 If this option is set, it would use zlib deflate method
1949 to compress the specified memory at its best effort.
1951 - Compression support:
1954 Enabled by default to support gzip compressed images.
1958 If this option is set, support for bzip2 compressed
1959 images is included. If not, only uncompressed and gzip
1960 compressed images are supported.
1962 NOTE: the bzip2 algorithm requires a lot of RAM, so
1963 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1968 If this option is set, support for lzma compressed
1971 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1972 requires an amount of dynamic memory that is given by the
1975 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1977 Where lc and lp stand for, respectively, Literal context bits
1978 and Literal pos bits.
1980 This value is upper-bounded by 14MB in the worst case. Anyway,
1981 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1982 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1983 a very small buffer.
1985 Use the lzmainfo tool to determinate the lc and lp values and
1986 then calculate the amount of needed dynamic memory (ensuring
1987 the appropriate CONFIG_SYS_MALLOC_LEN value).
1991 If this option is set, support for LZO compressed images
1997 The address of PHY on MII bus.
1999 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2001 The clock frequency of the MII bus
2005 If this option is set, support for speed/duplex
2006 detection of gigabit PHY is included.
2008 CONFIG_PHY_RESET_DELAY
2010 Some PHY like Intel LXT971A need extra delay after
2011 reset before any MII register access is possible.
2012 For such PHY, set this option to the usec delay
2013 required. (minimum 300usec for LXT971A)
2015 CONFIG_PHY_CMD_DELAY (ppc4xx)
2017 Some PHY like Intel LXT971A need extra delay after
2018 command issued before MII status register can be read
2023 Define a default value for the IP address to use for
2024 the default Ethernet interface, in case this is not
2025 determined through e.g. bootp.
2026 (Environment variable "ipaddr")
2028 - Server IP address:
2031 Defines a default value for the IP address of a TFTP
2032 server to contact when using the "tftboot" command.
2033 (Environment variable "serverip")
2035 CONFIG_KEEP_SERVERADDR
2037 Keeps the server's MAC address, in the env 'serveraddr'
2038 for passing to bootargs (like Linux's netconsole option)
2040 - Gateway IP address:
2043 Defines a default value for the IP address of the
2044 default router where packets to other networks are
2046 (Environment variable "gatewayip")
2051 Defines a default value for the subnet mask (or
2052 routing prefix) which is used to determine if an IP
2053 address belongs to the local subnet or needs to be
2054 forwarded through a router.
2055 (Environment variable "netmask")
2057 - Multicast TFTP Mode:
2060 Defines whether you want to support multicast TFTP as per
2061 rfc-2090; for example to work with atftp. Lets lots of targets
2062 tftp down the same boot image concurrently. Note: the Ethernet
2063 driver in use must provide a function: mcast() to join/leave a
2066 - BOOTP Recovery Mode:
2067 CONFIG_BOOTP_RANDOM_DELAY
2069 If you have many targets in a network that try to
2070 boot using BOOTP, you may want to avoid that all
2071 systems send out BOOTP requests at precisely the same
2072 moment (which would happen for instance at recovery
2073 from a power failure, when all systems will try to
2074 boot, thus flooding the BOOTP server. Defining
2075 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2076 inserted before sending out BOOTP requests. The
2077 following delays are inserted then:
2079 1st BOOTP request: delay 0 ... 1 sec
2080 2nd BOOTP request: delay 0 ... 2 sec
2081 3rd BOOTP request: delay 0 ... 4 sec
2083 BOOTP requests: delay 0 ... 8 sec
2085 CONFIG_BOOTP_ID_CACHE_SIZE
2087 BOOTP packets are uniquely identified using a 32-bit ID. The
2088 server will copy the ID from client requests to responses and
2089 U-Boot will use this to determine if it is the destination of
2090 an incoming response. Some servers will check that addresses
2091 aren't in use before handing them out (usually using an ARP
2092 ping) and therefore take up to a few hundred milliseconds to
2093 respond. Network congestion may also influence the time it
2094 takes for a response to make it back to the client. If that
2095 time is too long, U-Boot will retransmit requests. In order
2096 to allow earlier responses to still be accepted after these
2097 retransmissions, U-Boot's BOOTP client keeps a small cache of
2098 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2099 cache. The default is to keep IDs for up to four outstanding
2100 requests. Increasing this will allow U-Boot to accept offers
2101 from a BOOTP client in networks with unusually high latency.
2103 - DHCP Advanced Options:
2104 You can fine tune the DHCP functionality by defining
2105 CONFIG_BOOTP_* symbols:
2107 CONFIG_BOOTP_SUBNETMASK
2108 CONFIG_BOOTP_GATEWAY
2109 CONFIG_BOOTP_HOSTNAME
2110 CONFIG_BOOTP_NISDOMAIN
2111 CONFIG_BOOTP_BOOTPATH
2112 CONFIG_BOOTP_BOOTFILESIZE
2115 CONFIG_BOOTP_SEND_HOSTNAME
2116 CONFIG_BOOTP_NTPSERVER
2117 CONFIG_BOOTP_TIMEOFFSET
2118 CONFIG_BOOTP_VENDOREX
2119 CONFIG_BOOTP_MAY_FAIL
2121 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2122 environment variable, not the BOOTP server.
2124 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2125 after the configured retry count, the call will fail
2126 instead of starting over. This can be used to fail over
2127 to Link-local IP address configuration if the DHCP server
2130 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2131 serverip from a DHCP server, it is possible that more
2132 than one DNS serverip is offered to the client.
2133 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2134 serverip will be stored in the additional environment
2135 variable "dnsip2". The first DNS serverip is always
2136 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2139 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2140 to do a dynamic update of a DNS server. To do this, they
2141 need the hostname of the DHCP requester.
2142 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2143 of the "hostname" environment variable is passed as
2144 option 12 to the DHCP server.
2146 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2148 A 32bit value in microseconds for a delay between
2149 receiving a "DHCP Offer" and sending the "DHCP Request".
2150 This fixes a problem with certain DHCP servers that don't
2151 respond 100% of the time to a "DHCP request". E.g. On an
2152 AT91RM9200 processor running at 180MHz, this delay needed
2153 to be *at least* 15,000 usec before a Windows Server 2003
2154 DHCP server would reply 100% of the time. I recommend at
2155 least 50,000 usec to be safe. The alternative is to hope
2156 that one of the retries will be successful but note that
2157 the DHCP timeout and retry process takes a longer than
2160 - Link-local IP address negotiation:
2161 Negotiate with other link-local clients on the local network
2162 for an address that doesn't require explicit configuration.
2163 This is especially useful if a DHCP server cannot be guaranteed
2164 to exist in all environments that the device must operate.
2166 See doc/README.link-local for more information.
2169 CONFIG_CDP_DEVICE_ID
2171 The device id used in CDP trigger frames.
2173 CONFIG_CDP_DEVICE_ID_PREFIX
2175 A two character string which is prefixed to the MAC address
2180 A printf format string which contains the ascii name of
2181 the port. Normally is set to "eth%d" which sets
2182 eth0 for the first Ethernet, eth1 for the second etc.
2184 CONFIG_CDP_CAPABILITIES
2186 A 32bit integer which indicates the device capabilities;
2187 0x00000010 for a normal host which does not forwards.
2191 An ascii string containing the version of the software.
2195 An ascii string containing the name of the platform.
2199 A 32bit integer sent on the trigger.
2201 CONFIG_CDP_POWER_CONSUMPTION
2203 A 16bit integer containing the power consumption of the
2204 device in .1 of milliwatts.
2206 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2208 A byte containing the id of the VLAN.
2210 - Status LED: CONFIG_STATUS_LED
2212 Several configurations allow to display the current
2213 status using a LED. For instance, the LED will blink
2214 fast while running U-Boot code, stop blinking as
2215 soon as a reply to a BOOTP request was received, and
2216 start blinking slow once the Linux kernel is running
2217 (supported by a status LED driver in the Linux
2218 kernel). Defining CONFIG_STATUS_LED enables this
2224 The status LED can be connected to a GPIO pin.
2225 In such cases, the gpio_led driver can be used as a
2226 status LED backend implementation. Define CONFIG_GPIO_LED
2227 to include the gpio_led driver in the U-Boot binary.
2229 CONFIG_GPIO_LED_INVERTED_TABLE
2230 Some GPIO connected LEDs may have inverted polarity in which
2231 case the GPIO high value corresponds to LED off state and
2232 GPIO low value corresponds to LED on state.
2233 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2234 with a list of GPIO LEDs that have inverted polarity.
2236 - CAN Support: CONFIG_CAN_DRIVER
2238 Defining CONFIG_CAN_DRIVER enables CAN driver support
2239 on those systems that support this (optional)
2240 feature, like the TQM8xxL modules.
2242 - I2C Support: CONFIG_SYS_I2C
2244 This enable the NEW i2c subsystem, and will allow you to use
2245 i2c commands at the u-boot command line (as long as you set
2246 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2247 based realtime clock chips or other i2c devices. See
2248 common/cmd_i2c.c for a description of the command line
2251 ported i2c driver to the new framework:
2252 - drivers/i2c/soft_i2c.c:
2253 - activate first bus with CONFIG_SYS_I2C_SOFT define
2254 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2255 for defining speed and slave address
2256 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2257 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2258 for defining speed and slave address
2259 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2260 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2261 for defining speed and slave address
2262 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2263 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2264 for defining speed and slave address
2266 - drivers/i2c/fsl_i2c.c:
2267 - activate i2c driver with CONFIG_SYS_I2C_FSL
2268 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2269 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2270 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2272 - If your board supports a second fsl i2c bus, define
2273 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2274 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2275 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2278 - drivers/i2c/tegra_i2c.c:
2279 - activate this driver with CONFIG_SYS_I2C_TEGRA
2280 - This driver adds 4 i2c buses with a fix speed from
2281 100000 and the slave addr 0!
2283 - drivers/i2c/ppc4xx_i2c.c
2284 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2285 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2286 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2288 - drivers/i2c/i2c_mxc.c
2289 - activate this driver with CONFIG_SYS_I2C_MXC
2290 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2291 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2292 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2293 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2294 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2295 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2296 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2297 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2298 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2299 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2300 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2301 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2302 If those defines are not set, default value is 100000
2303 for speed, and 0 for slave.
2305 - drivers/i2c/rcar_i2c.c:
2306 - activate this driver with CONFIG_SYS_I2C_RCAR
2307 - This driver adds 4 i2c buses
2309 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2310 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2311 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2312 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2313 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2314 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2315 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2316 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2317 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2319 - drivers/i2c/sh_i2c.c:
2320 - activate this driver with CONFIG_SYS_I2C_SH
2321 - This driver adds from 2 to 5 i2c buses
2323 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2324 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2325 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2326 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2327 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2328 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2329 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2330 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2331 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2332 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2333 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2334 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2335 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2337 - drivers/i2c/omap24xx_i2c.c
2338 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2339 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2340 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2341 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2342 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2343 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2344 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2345 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2346 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2347 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2348 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2350 - drivers/i2c/zynq_i2c.c
2351 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2352 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2353 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2355 - drivers/i2c/s3c24x0_i2c.c:
2356 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2357 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2358 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2359 with a fix speed from 100000 and the slave addr 0!
2361 - drivers/i2c/ihs_i2c.c
2362 - activate this driver with CONFIG_SYS_I2C_IHS
2363 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2364 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2365 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2366 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2367 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2368 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2369 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2370 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2371 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2372 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2373 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2374 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2375 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2376 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2377 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2378 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2379 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2380 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2381 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2382 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2383 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2387 CONFIG_SYS_NUM_I2C_BUSES
2388 Hold the number of i2c buses you want to use. If you
2389 don't use/have i2c muxes on your i2c bus, this
2390 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2393 CONFIG_SYS_I2C_DIRECT_BUS
2394 define this, if you don't use i2c muxes on your hardware.
2395 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2398 CONFIG_SYS_I2C_MAX_HOPS
2399 define how many muxes are maximal consecutively connected
2400 on one i2c bus. If you not use i2c muxes, omit this
2403 CONFIG_SYS_I2C_BUSES
2404 hold a list of buses you want to use, only used if
2405 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2406 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2407 CONFIG_SYS_NUM_I2C_BUSES = 9:
2409 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2410 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2411 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2412 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2413 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2414 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2415 {1, {I2C_NULL_HOP}}, \
2416 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2417 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2421 bus 0 on adapter 0 without a mux
2422 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2423 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2424 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2425 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2426 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2427 bus 6 on adapter 1 without a mux
2428 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2429 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2431 If you do not have i2c muxes on your board, omit this define.
2433 - Legacy I2C Support: CONFIG_HARD_I2C
2435 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2436 provides the following compelling advantages:
2438 - more than one i2c adapter is usable
2439 - approved multibus support
2440 - better i2c mux support
2442 ** Please consider updating your I2C driver now. **
2444 These enable legacy I2C serial bus commands. Defining
2445 CONFIG_HARD_I2C will include the appropriate I2C driver
2446 for the selected CPU.
2448 This will allow you to use i2c commands at the u-boot
2449 command line (as long as you set CONFIG_CMD_I2C in
2450 CONFIG_COMMANDS) and communicate with i2c based realtime
2451 clock chips. See common/cmd_i2c.c for a description of the
2452 command line interface.
2454 CONFIG_HARD_I2C selects a hardware I2C controller.
2456 There are several other quantities that must also be
2457 defined when you define CONFIG_HARD_I2C.
2459 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2460 to be the frequency (in Hz) at which you wish your i2c bus
2461 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2462 the CPU's i2c node address).
2464 Now, the u-boot i2c code for the mpc8xx
2465 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2466 and so its address should therefore be cleared to 0 (See,
2467 eg, MPC823e User's Manual p.16-473). So, set
2468 CONFIG_SYS_I2C_SLAVE to 0.
2470 CONFIG_SYS_I2C_INIT_MPC5XXX
2472 When a board is reset during an i2c bus transfer
2473 chips might think that the current transfer is still
2474 in progress. Reset the slave devices by sending start
2475 commands until the slave device responds.
2477 That's all that's required for CONFIG_HARD_I2C.
2479 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2480 then the following macros need to be defined (examples are
2481 from include/configs/lwmon.h):
2485 (Optional). Any commands necessary to enable the I2C
2486 controller or configure ports.
2488 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2492 (Only for MPC8260 CPU). The I/O port to use (the code
2493 assumes both bits are on the same port). Valid values
2494 are 0..3 for ports A..D.
2498 The code necessary to make the I2C data line active
2499 (driven). If the data line is open collector, this
2502 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2506 The code necessary to make the I2C data line tri-stated
2507 (inactive). If the data line is open collector, this
2510 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2514 Code that returns true if the I2C data line is high,
2517 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2521 If <bit> is true, sets the I2C data line high. If it
2522 is false, it clears it (low).
2524 eg: #define I2C_SDA(bit) \
2525 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2526 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2530 If <bit> is true, sets the I2C clock line high. If it
2531 is false, it clears it (low).
2533 eg: #define I2C_SCL(bit) \
2534 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2535 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2539 This delay is invoked four times per clock cycle so this
2540 controls the rate of data transfer. The data rate thus
2541 is 1 / (I2C_DELAY * 4). Often defined to be something
2544 #define I2C_DELAY udelay(2)
2546 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2548 If your arch supports the generic GPIO framework (asm/gpio.h),
2549 then you may alternatively define the two GPIOs that are to be
2550 used as SCL / SDA. Any of the previous I2C_xxx macros will
2551 have GPIO-based defaults assigned to them as appropriate.
2553 You should define these to the GPIO value as given directly to
2554 the generic GPIO functions.
2556 CONFIG_SYS_I2C_INIT_BOARD
2558 When a board is reset during an i2c bus transfer
2559 chips might think that the current transfer is still
2560 in progress. On some boards it is possible to access
2561 the i2c SCLK line directly, either by using the
2562 processor pin as a GPIO or by having a second pin
2563 connected to the bus. If this option is defined a
2564 custom i2c_init_board() routine in boards/xxx/board.c
2565 is run early in the boot sequence.
2567 CONFIG_SYS_I2C_BOARD_LATE_INIT
2569 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2570 defined a custom i2c_board_late_init() routine in
2571 boards/xxx/board.c is run AFTER the operations in i2c_init()
2572 is completed. This callpoint can be used to unreset i2c bus
2573 using CPU i2c controller register accesses for CPUs whose i2c
2574 controller provide such a method. It is called at the end of
2575 i2c_init() to allow i2c_init operations to setup the i2c bus
2576 controller on the CPU (e.g. setting bus speed & slave address).
2578 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2580 This option enables configuration of bi_iic_fast[] flags
2581 in u-boot bd_info structure based on u-boot environment
2582 variable "i2cfast". (see also i2cfast)
2584 CONFIG_I2C_MULTI_BUS
2586 This option allows the use of multiple I2C buses, each of which
2587 must have a controller. At any point in time, only one bus is
2588 active. To switch to a different bus, use the 'i2c dev' command.
2589 Note that bus numbering is zero-based.
2591 CONFIG_SYS_I2C_NOPROBES
2593 This option specifies a list of I2C devices that will be skipped
2594 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2595 is set, specify a list of bus-device pairs. Otherwise, specify
2596 a 1D array of device addresses
2599 #undef CONFIG_I2C_MULTI_BUS
2600 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2602 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2604 #define CONFIG_I2C_MULTI_BUS
2605 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2607 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2609 CONFIG_SYS_SPD_BUS_NUM
2611 If defined, then this indicates the I2C bus number for DDR SPD.
2612 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2614 CONFIG_SYS_RTC_BUS_NUM
2616 If defined, then this indicates the I2C bus number for the RTC.
2617 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2619 CONFIG_SYS_DTT_BUS_NUM
2621 If defined, then this indicates the I2C bus number for the DTT.
2622 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2624 CONFIG_SYS_I2C_DTT_ADDR:
2626 If defined, specifies the I2C address of the DTT device.
2627 If not defined, then U-Boot uses predefined value for
2628 specified DTT device.
2630 CONFIG_SOFT_I2C_READ_REPEATED_START
2632 defining this will force the i2c_read() function in
2633 the soft_i2c driver to perform an I2C repeated start
2634 between writing the address pointer and reading the
2635 data. If this define is omitted the default behaviour
2636 of doing a stop-start sequence will be used. Most I2C
2637 devices can use either method, but some require one or
2640 - SPI Support: CONFIG_SPI
2642 Enables SPI driver (so far only tested with
2643 SPI EEPROM, also an instance works with Crystal A/D and
2644 D/As on the SACSng board)
2648 Enables the driver for SPI controller on SuperH. Currently
2649 only SH7757 is supported.
2653 Enables a software (bit-bang) SPI driver rather than
2654 using hardware support. This is a general purpose
2655 driver that only requires three general I/O port pins
2656 (two outputs, one input) to function. If this is
2657 defined, the board configuration must define several
2658 SPI configuration items (port pins to use, etc). For
2659 an example, see include/configs/sacsng.h.
2663 Enables a hardware SPI driver for general-purpose reads
2664 and writes. As with CONFIG_SOFT_SPI, the board configuration
2665 must define a list of chip-select function pointers.
2666 Currently supported on some MPC8xxx processors. For an
2667 example, see include/configs/mpc8349emds.h.
2671 Enables the driver for the SPI controllers on i.MX and MXC
2672 SoCs. Currently i.MX31/35/51 are supported.
2674 CONFIG_SYS_SPI_MXC_WAIT
2675 Timeout for waiting until spi transfer completed.
2676 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2678 - FPGA Support: CONFIG_FPGA
2680 Enables FPGA subsystem.
2682 CONFIG_FPGA_<vendor>
2684 Enables support for specific chip vendors.
2687 CONFIG_FPGA_<family>
2689 Enables support for FPGA family.
2690 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2694 Specify the number of FPGA devices to support.
2696 CONFIG_CMD_FPGA_LOADMK
2698 Enable support for fpga loadmk command
2700 CONFIG_CMD_FPGA_LOADP
2702 Enable support for fpga loadp command - load partial bitstream
2704 CONFIG_CMD_FPGA_LOADBP
2706 Enable support for fpga loadbp command - load partial bitstream
2709 CONFIG_SYS_FPGA_PROG_FEEDBACK
2711 Enable printing of hash marks during FPGA configuration.
2713 CONFIG_SYS_FPGA_CHECK_BUSY
2715 Enable checks on FPGA configuration interface busy
2716 status by the configuration function. This option
2717 will require a board or device specific function to
2722 If defined, a function that provides delays in the FPGA
2723 configuration driver.
2725 CONFIG_SYS_FPGA_CHECK_CTRLC
2726 Allow Control-C to interrupt FPGA configuration
2728 CONFIG_SYS_FPGA_CHECK_ERROR
2730 Check for configuration errors during FPGA bitfile
2731 loading. For example, abort during Virtex II
2732 configuration if the INIT_B line goes low (which
2733 indicated a CRC error).
2735 CONFIG_SYS_FPGA_WAIT_INIT
2737 Maximum time to wait for the INIT_B line to de-assert
2738 after PROB_B has been de-asserted during a Virtex II
2739 FPGA configuration sequence. The default time is 500
2742 CONFIG_SYS_FPGA_WAIT_BUSY
2744 Maximum time to wait for BUSY to de-assert during
2745 Virtex II FPGA configuration. The default is 5 ms.
2747 CONFIG_SYS_FPGA_WAIT_CONFIG
2749 Time to wait after FPGA configuration. The default is
2752 - Configuration Management:
2755 Some SoCs need special image types (e.g. U-Boot binary
2756 with a special header) as build targets. By defining
2757 CONFIG_BUILD_TARGET in the SoC / board header, this
2758 special image will be automatically built upon calling
2763 If defined, this string will be added to the U-Boot
2764 version information (U_BOOT_VERSION)
2766 - Vendor Parameter Protection:
2768 U-Boot considers the values of the environment
2769 variables "serial#" (Board Serial Number) and
2770 "ethaddr" (Ethernet Address) to be parameters that
2771 are set once by the board vendor / manufacturer, and
2772 protects these variables from casual modification by
2773 the user. Once set, these variables are read-only,
2774 and write or delete attempts are rejected. You can
2775 change this behaviour:
2777 If CONFIG_ENV_OVERWRITE is #defined in your config
2778 file, the write protection for vendor parameters is
2779 completely disabled. Anybody can change or delete
2782 Alternatively, if you define _both_ an ethaddr in the
2783 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2784 Ethernet address is installed in the environment,
2785 which can be changed exactly ONCE by the user. [The
2786 serial# is unaffected by this, i. e. it remains
2789 The same can be accomplished in a more flexible way
2790 for any variable by configuring the type of access
2791 to allow for those variables in the ".flags" variable
2792 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2797 Define this variable to enable the reservation of
2798 "protected RAM", i. e. RAM which is not overwritten
2799 by U-Boot. Define CONFIG_PRAM to hold the number of
2800 kB you want to reserve for pRAM. You can overwrite
2801 this default value by defining an environment
2802 variable "pram" to the number of kB you want to
2803 reserve. Note that the board info structure will
2804 still show the full amount of RAM. If pRAM is
2805 reserved, a new environment variable "mem" will
2806 automatically be defined to hold the amount of
2807 remaining RAM in a form that can be passed as boot
2808 argument to Linux, for instance like that:
2810 setenv bootargs ... mem=\${mem}
2813 This way you can tell Linux not to use this memory,
2814 either, which results in a memory region that will
2815 not be affected by reboots.
2817 *WARNING* If your board configuration uses automatic
2818 detection of the RAM size, you must make sure that
2819 this memory test is non-destructive. So far, the
2820 following board configurations are known to be
2823 IVMS8, IVML24, SPD8xx, TQM8xxL,
2824 HERMES, IP860, RPXlite, LWMON,
2827 - Access to physical memory region (> 4GB)
2828 Some basic support is provided for operations on memory not
2829 normally accessible to U-Boot - e.g. some architectures
2830 support access to more than 4GB of memory on 32-bit
2831 machines using physical address extension or similar.
2832 Define CONFIG_PHYSMEM to access this basic support, which
2833 currently only supports clearing the memory.
2838 Define this variable to stop the system in case of a
2839 fatal error, so that you have to reset it manually.
2840 This is probably NOT a good idea for an embedded
2841 system where you want the system to reboot
2842 automatically as fast as possible, but it may be
2843 useful during development since you can try to debug
2844 the conditions that lead to the situation.
2846 CONFIG_NET_RETRY_COUNT
2848 This variable defines the number of retries for
2849 network operations like ARP, RARP, TFTP, or BOOTP
2850 before giving up the operation. If not defined, a
2851 default value of 5 is used.
2855 Timeout waiting for an ARP reply in milliseconds.
2859 Timeout in milliseconds used in NFS protocol.
2860 If you encounter "ERROR: Cannot umount" in nfs command,
2861 try longer timeout such as
2862 #define CONFIG_NFS_TIMEOUT 10000UL
2864 - Command Interpreter:
2865 CONFIG_AUTO_COMPLETE
2867 Enable auto completion of commands using TAB.
2869 CONFIG_SYS_PROMPT_HUSH_PS2
2871 This defines the secondary prompt string, which is
2872 printed when the command interpreter needs more input
2873 to complete a command. Usually "> ".
2877 In the current implementation, the local variables
2878 space and global environment variables space are
2879 separated. Local variables are those you define by
2880 simply typing `name=value'. To access a local
2881 variable later on, you have write `$name' or
2882 `${name}'; to execute the contents of a variable
2883 directly type `$name' at the command prompt.
2885 Global environment variables are those you use
2886 setenv/printenv to work with. To run a command stored
2887 in such a variable, you need to use the run command,
2888 and you must not use the '$' sign to access them.
2890 To store commands and special characters in a
2891 variable, please use double quotation marks
2892 surrounding the whole text of the variable, instead
2893 of the backslashes before semicolons and special
2896 - Command Line Editing and History:
2897 CONFIG_CMDLINE_EDITING
2899 Enable editing and History functions for interactive
2900 command line input operations
2902 - Command Line PS1/PS2 support:
2903 CONFIG_CMDLINE_PS_SUPPORT
2905 Enable support for changing the command prompt string
2906 at run-time. Only static string is supported so far.
2907 The string is obtained from environment variables PS1
2910 - Default Environment:
2911 CONFIG_EXTRA_ENV_SETTINGS
2913 Define this to contain any number of null terminated
2914 strings (variable = value pairs) that will be part of
2915 the default environment compiled into the boot image.
2917 For example, place something like this in your
2918 board's config file:
2920 #define CONFIG_EXTRA_ENV_SETTINGS \
2924 Warning: This method is based on knowledge about the
2925 internal format how the environment is stored by the
2926 U-Boot code. This is NOT an official, exported
2927 interface! Although it is unlikely that this format
2928 will change soon, there is no guarantee either.
2929 You better know what you are doing here.
2931 Note: overly (ab)use of the default environment is
2932 discouraged. Make sure to check other ways to preset
2933 the environment like the "source" command or the
2936 CONFIG_ENV_VARS_UBOOT_CONFIG
2938 Define this in order to add variables describing the
2939 U-Boot build configuration to the default environment.
2940 These will be named arch, cpu, board, vendor, and soc.
2942 Enabling this option will cause the following to be defined:
2950 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2952 Define this in order to add variables describing certain
2953 run-time determined information about the hardware to the
2954 environment. These will be named board_name, board_rev.
2956 CONFIG_DELAY_ENVIRONMENT
2958 Normally the environment is loaded when the board is
2959 initialised so that it is available to U-Boot. This inhibits
2960 that so that the environment is not available until
2961 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2962 this is instead controlled by the value of
2963 /config/load-environment.
2965 - Parallel Flash support:
2968 Traditionally U-Boot was run on systems with parallel NOR
2969 flash. This option is used to disable support for parallel NOR
2970 flash. This option should be defined if the board does not have
2973 If this option is not defined one of the generic flash drivers
2974 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2975 selected or the board must provide an implementation of the
2976 flash API (see include/flash.h).
2978 - DataFlash Support:
2979 CONFIG_HAS_DATAFLASH
2981 Defining this option enables DataFlash features and
2982 allows to read/write in Dataflash via the standard
2985 - Serial Flash support
2988 Defining this option enables SPI flash commands
2989 'sf probe/read/write/erase/update'.
2991 Usage requires an initial 'probe' to define the serial
2992 flash parameters, followed by read/write/erase/update
2995 The following defaults may be provided by the platform
2996 to handle the common case when only a single serial
2997 flash is present on the system.
2999 CONFIG_SF_DEFAULT_BUS Bus identifier
3000 CONFIG_SF_DEFAULT_CS Chip-select
3001 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3002 CONFIG_SF_DEFAULT_SPEED in Hz
3006 Define this option to include a destructive SPI flash
3009 CONFIG_SF_DUAL_FLASH Dual flash memories
3011 Define this option to use dual flash support where two flash
3012 memories can be connected with a given cs line.
3013 Currently Xilinx Zynq qspi supports these type of connections.
3015 - SystemACE Support:
3018 Adding this option adds support for Xilinx SystemACE
3019 chips attached via some sort of local bus. The address
3020 of the chip must also be defined in the
3021 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3023 #define CONFIG_SYSTEMACE
3024 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3026 When SystemACE support is added, the "ace" device type
3027 becomes available to the fat commands, i.e. fatls.
3029 - TFTP Fixed UDP Port:
3032 If this is defined, the environment variable tftpsrcp
3033 is used to supply the TFTP UDP source port value.
3034 If tftpsrcp isn't defined, the normal pseudo-random port
3035 number generator is used.
3037 Also, the environment variable tftpdstp is used to supply
3038 the TFTP UDP destination port value. If tftpdstp isn't
3039 defined, the normal port 69 is used.
3041 The purpose for tftpsrcp is to allow a TFTP server to
3042 blindly start the TFTP transfer using the pre-configured
3043 target IP address and UDP port. This has the effect of
3044 "punching through" the (Windows XP) firewall, allowing
3045 the remainder of the TFTP transfer to proceed normally.
3046 A better solution is to properly configure the firewall,
3047 but sometimes that is not allowed.
3052 This enables a generic 'hash' command which can produce
3053 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3057 Enable the hash verify command (hash -v). This adds to code
3060 CONFIG_SHA1 - This option enables support of hashing using SHA1
3061 algorithm. The hash is calculated in software.
3062 CONFIG_SHA256 - This option enables support of hashing using
3063 SHA256 algorithm. The hash is calculated in software.
3064 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3065 for SHA1/SHA256 hashing.
3066 This affects the 'hash' command and also the
3067 hash_lookup_algo() function.
3068 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3069 hardware-acceleration for SHA1/SHA256 progressive hashing.
3070 Data can be streamed in a block at a time and the hashing
3071 is performed in hardware.
3073 Note: There is also a sha1sum command, which should perhaps
3074 be deprecated in favour of 'hash sha1'.
3076 - Freescale i.MX specific commands:
3077 CONFIG_CMD_HDMIDETECT
3078 This enables 'hdmidet' command which returns true if an
3079 HDMI monitor is detected. This command is i.MX 6 specific.
3082 This enables the 'bmode' (bootmode) command for forcing
3083 a boot from specific media.
3085 This is useful for forcing the ROM's usb downloader to
3086 activate upon a watchdog reset which is nice when iterating
3087 on U-Boot. Using the reset button or running bmode normal
3088 will set it back to normal. This command currently
3089 supports i.MX53 and i.MX6.
3091 - bootcount support:
3092 CONFIG_BOOTCOUNT_LIMIT
3094 This enables the bootcounter support, see:
3095 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3098 enable special bootcounter support on at91sam9xe based boards.
3100 enable special bootcounter support on blackfin based boards.
3102 enable special bootcounter support on da850 based boards.
3103 CONFIG_BOOTCOUNT_RAM
3104 enable support for the bootcounter in RAM
3105 CONFIG_BOOTCOUNT_I2C
3106 enable support for the bootcounter on an i2c (like RTC) device.
3107 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3108 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3110 CONFIG_BOOTCOUNT_ALEN = address len
3112 - Show boot progress:
3113 CONFIG_SHOW_BOOT_PROGRESS
3115 Defining this option allows to add some board-
3116 specific code (calling a user-provided function
3117 "show_boot_progress(int)") that enables you to show
3118 the system's boot progress on some display (for
3119 example, some LED's) on your board. At the moment,
3120 the following checkpoints are implemented:
3123 Legacy uImage format:
3126 1 common/cmd_bootm.c before attempting to boot an image
3127 -1 common/cmd_bootm.c Image header has bad magic number
3128 2 common/cmd_bootm.c Image header has correct magic number
3129 -2 common/cmd_bootm.c Image header has bad checksum
3130 3 common/cmd_bootm.c Image header has correct checksum
3131 -3 common/cmd_bootm.c Image data has bad checksum
3132 4 common/cmd_bootm.c Image data has correct checksum
3133 -4 common/cmd_bootm.c Image is for unsupported architecture
3134 5 common/cmd_bootm.c Architecture check OK
3135 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3136 6 common/cmd_bootm.c Image Type check OK
3137 -6 common/cmd_bootm.c gunzip uncompression error
3138 -7 common/cmd_bootm.c Unimplemented compression type
3139 7 common/cmd_bootm.c Uncompression OK
3140 8 common/cmd_bootm.c No uncompress/copy overwrite error
3141 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3143 9 common/image.c Start initial ramdisk verification
3144 -10 common/image.c Ramdisk header has bad magic number
3145 -11 common/image.c Ramdisk header has bad checksum
3146 10 common/image.c Ramdisk header is OK
3147 -12 common/image.c Ramdisk data has bad checksum
3148 11 common/image.c Ramdisk data has correct checksum
3149 12 common/image.c Ramdisk verification complete, start loading
3150 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3151 13 common/image.c Start multifile image verification
3152 14 common/image.c No initial ramdisk, no multifile, continue.
3154 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3156 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3157 -31 post/post.c POST test failed, detected by post_output_backlog()
3158 -32 post/post.c POST test failed, detected by post_run_single()
3160 34 common/cmd_doc.c before loading a Image from a DOC device
3161 -35 common/cmd_doc.c Bad usage of "doc" command
3162 35 common/cmd_doc.c correct usage of "doc" command
3163 -36 common/cmd_doc.c No boot device
3164 36 common/cmd_doc.c correct boot device
3165 -37 common/cmd_doc.c Unknown Chip ID on boot device
3166 37 common/cmd_doc.c correct chip ID found, device available
3167 -38 common/cmd_doc.c Read Error on boot device
3168 38 common/cmd_doc.c reading Image header from DOC device OK
3169 -39 common/cmd_doc.c Image header has bad magic number
3170 39 common/cmd_doc.c Image header has correct magic number
3171 -40 common/cmd_doc.c Error reading Image from DOC device
3172 40 common/cmd_doc.c Image header has correct magic number
3173 41 common/cmd_ide.c before loading a Image from a IDE device
3174 -42 common/cmd_ide.c Bad usage of "ide" command
3175 42 common/cmd_ide.c correct usage of "ide" command
3176 -43 common/cmd_ide.c No boot device
3177 43 common/cmd_ide.c boot device found
3178 -44 common/cmd_ide.c Device not available
3179 44 common/cmd_ide.c Device available
3180 -45 common/cmd_ide.c wrong partition selected
3181 45 common/cmd_ide.c partition selected
3182 -46 common/cmd_ide.c Unknown partition table
3183 46 common/cmd_ide.c valid partition table found
3184 -47 common/cmd_ide.c Invalid partition type
3185 47 common/cmd_ide.c correct partition type
3186 -48 common/cmd_ide.c Error reading Image Header on boot device
3187 48 common/cmd_ide.c reading Image Header from IDE device OK
3188 -49 common/cmd_ide.c Image header has bad magic number
3189 49 common/cmd_ide.c Image header has correct magic number
3190 -50 common/cmd_ide.c Image header has bad checksum
3191 50 common/cmd_ide.c Image header has correct checksum
3192 -51 common/cmd_ide.c Error reading Image from IDE device
3193 51 common/cmd_ide.c reading Image from IDE device OK
3194 52 common/cmd_nand.c before loading a Image from a NAND device
3195 -53 common/cmd_nand.c Bad usage of "nand" command
3196 53 common/cmd_nand.c correct usage of "nand" command
3197 -54 common/cmd_nand.c No boot device
3198 54 common/cmd_nand.c boot device found
3199 -55 common/cmd_nand.c Unknown Chip ID on boot device
3200 55 common/cmd_nand.c correct chip ID found, device available
3201 -56 common/cmd_nand.c Error reading Image Header on boot device
3202 56 common/cmd_nand.c reading Image Header from NAND device OK
3203 -57 common/cmd_nand.c Image header has bad magic number
3204 57 common/cmd_nand.c Image header has correct magic number
3205 -58 common/cmd_nand.c Error reading Image from NAND device
3206 58 common/cmd_nand.c reading Image from NAND device OK
3208 -60 common/env_common.c Environment has a bad CRC, using default
3210 64 net/eth.c starting with Ethernet configuration.
3211 -64 net/eth.c no Ethernet found.
3212 65 net/eth.c Ethernet found.
3214 -80 common/cmd_net.c usage wrong
3215 80 common/cmd_net.c before calling net_loop()
3216 -81 common/cmd_net.c some error in net_loop() occurred
3217 81 common/cmd_net.c net_loop() back without error
3218 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3219 82 common/cmd_net.c trying automatic boot
3220 83 common/cmd_net.c running "source" command
3221 -83 common/cmd_net.c some error in automatic boot or "source" command
3222 84 common/cmd_net.c end without errors
3227 100 common/cmd_bootm.c Kernel FIT Image has correct format
3228 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3229 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3230 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3231 102 common/cmd_bootm.c Kernel unit name specified
3232 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3233 103 common/cmd_bootm.c Found configuration node
3234 104 common/cmd_bootm.c Got kernel subimage node offset
3235 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3236 105 common/cmd_bootm.c Kernel subimage hash verification OK
3237 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3238 106 common/cmd_bootm.c Architecture check OK
3239 -106 common/cmd_bootm.c Kernel subimage has wrong type
3240 107 common/cmd_bootm.c Kernel subimage type OK
3241 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3242 108 common/cmd_bootm.c Got kernel subimage data/size
3243 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3244 -109 common/cmd_bootm.c Can't get kernel subimage type
3245 -110 common/cmd_bootm.c Can't get kernel subimage comp
3246 -111 common/cmd_bootm.c Can't get kernel subimage os
3247 -112 common/cmd_bootm.c Can't get kernel subimage load address
3248 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3250 120 common/image.c Start initial ramdisk verification
3251 -120 common/image.c Ramdisk FIT image has incorrect format
3252 121 common/image.c Ramdisk FIT image has correct format
3253 122 common/image.c No ramdisk subimage unit name, using configuration
3254 -122 common/image.c Can't get configuration for ramdisk subimage
3255 123 common/image.c Ramdisk unit name specified
3256 -124 common/image.c Can't get ramdisk subimage node offset
3257 125 common/image.c Got ramdisk subimage node offset
3258 -125 common/image.c Ramdisk subimage hash verification failed
3259 126 common/image.c Ramdisk subimage hash verification OK
3260 -126 common/image.c Ramdisk subimage for unsupported architecture
3261 127 common/image.c Architecture check OK
3262 -127 common/image.c Can't get ramdisk subimage data/size
3263 128 common/image.c Got ramdisk subimage data/size
3264 129 common/image.c Can't get ramdisk load address
3265 -129 common/image.c Got ramdisk load address
3267 -130 common/cmd_doc.c Incorrect FIT image format
3268 131 common/cmd_doc.c FIT image format OK
3270 -140 common/cmd_ide.c Incorrect FIT image format
3271 141 common/cmd_ide.c FIT image format OK
3273 -150 common/cmd_nand.c Incorrect FIT image format
3274 151 common/cmd_nand.c FIT image format OK
3276 - legacy image format:
3277 CONFIG_IMAGE_FORMAT_LEGACY
3278 enables the legacy image format support in U-Boot.
3281 enabled if CONFIG_FIT_SIGNATURE is not defined.
3283 CONFIG_DISABLE_IMAGE_LEGACY
3284 disable the legacy image format
3286 This define is introduced, as the legacy image format is
3287 enabled per default for backward compatibility.
3289 - FIT image support:
3290 CONFIG_FIT_DISABLE_SHA256
3291 Supporting SHA256 hashes has quite an impact on binary size.
3292 For constrained systems sha256 hash support can be disabled
3295 TODO(sjg@chromium.org): Adjust this option to be positive,
3296 and move it to Kconfig
3298 - Standalone program support:
3299 CONFIG_STANDALONE_LOAD_ADDR
3301 This option defines a board specific value for the
3302 address where standalone program gets loaded, thus
3303 overwriting the architecture dependent default
3306 - Frame Buffer Address:
3309 Define CONFIG_FB_ADDR if you want to use specific
3310 address for frame buffer. This is typically the case
3311 when using a graphics controller has separate video
3312 memory. U-Boot will then place the frame buffer at
3313 the given address instead of dynamically reserving it
3314 in system RAM by calling lcd_setmem(), which grabs
3315 the memory for the frame buffer depending on the
3316 configured panel size.
3318 Please see board_init_f function.
3320 - Automatic software updates via TFTP server
3322 CONFIG_UPDATE_TFTP_CNT_MAX
3323 CONFIG_UPDATE_TFTP_MSEC_MAX
3325 These options enable and control the auto-update feature;
3326 for a more detailed description refer to doc/README.update.
3328 - MTD Support (mtdparts command, UBI support)
3331 Adds the MTD device infrastructure from the Linux kernel.
3332 Needed for mtdparts command support.
3334 CONFIG_MTD_PARTITIONS
3336 Adds the MTD partitioning infrastructure from the Linux
3337 kernel. Needed for UBI support.
3342 Adds commands for interacting with MTD partitions formatted
3343 with the UBI flash translation layer
3345 Requires also defining CONFIG_RBTREE
3347 CONFIG_UBI_SILENCE_MSG
3349 Make the verbose messages from UBI stop printing. This leaves
3350 warnings and errors enabled.
3353 CONFIG_MTD_UBI_WL_THRESHOLD
3354 This parameter defines the maximum difference between the highest
3355 erase counter value and the lowest erase counter value of eraseblocks
3356 of UBI devices. When this threshold is exceeded, UBI starts performing
3357 wear leveling by means of moving data from eraseblock with low erase
3358 counter to eraseblocks with high erase counter.
3360 The default value should be OK for SLC NAND flashes, NOR flashes and
3361 other flashes which have eraseblock life-cycle 100000 or more.
3362 However, in case of MLC NAND flashes which typically have eraseblock
3363 life-cycle less than 10000, the threshold should be lessened (e.g.,
3364 to 128 or 256, although it does not have to be power of 2).
3368 CONFIG_MTD_UBI_BEB_LIMIT
3369 This option specifies the maximum bad physical eraseblocks UBI
3370 expects on the MTD device (per 1024 eraseblocks). If the
3371 underlying flash does not admit of bad eraseblocks (e.g. NOR
3372 flash), this value is ignored.
3374 NAND datasheets often specify the minimum and maximum NVM
3375 (Number of Valid Blocks) for the flashes' endurance lifetime.
3376 The maximum expected bad eraseblocks per 1024 eraseblocks
3377 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3378 which gives 20 for most NANDs (MaxNVB is basically the total
3379 count of eraseblocks on the chip).
3381 To put it differently, if this value is 20, UBI will try to
3382 reserve about 1.9% of physical eraseblocks for bad blocks
3383 handling. And that will be 1.9% of eraseblocks on the entire
3384 NAND chip, not just the MTD partition UBI attaches. This means
3385 that if you have, say, a NAND flash chip admits maximum 40 bad
3386 eraseblocks, and it is split on two MTD partitions of the same
3387 size, UBI will reserve 40 eraseblocks when attaching a
3392 CONFIG_MTD_UBI_FASTMAP
3393 Fastmap is a mechanism which allows attaching an UBI device
3394 in nearly constant time. Instead of scanning the whole MTD device it
3395 only has to locate a checkpoint (called fastmap) on the device.
3396 The on-flash fastmap contains all information needed to attach
3397 the device. Using fastmap makes only sense on large devices where
3398 attaching by scanning takes long. UBI will not automatically install
3399 a fastmap on old images, but you can set the UBI parameter
3400 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3401 that fastmap-enabled images are still usable with UBI implementations
3402 without fastmap support. On typical flash devices the whole fastmap
3403 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3405 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3406 Set this parameter to enable fastmap automatically on images
3410 CONFIG_MTD_UBI_FM_DEBUG
3411 Enable UBI fastmap debug
3417 Adds commands for interacting with UBI volumes formatted as
3418 UBIFS. UBIFS is read-only in u-boot.
3420 Requires UBI support as well as CONFIG_LZO
3422 CONFIG_UBIFS_SILENCE_MSG
3424 Make the verbose messages from UBIFS stop printing. This leaves
3425 warnings and errors enabled.
3429 Enable building of SPL globally.
3432 LDSCRIPT for linking the SPL binary.
3434 CONFIG_SPL_MAX_FOOTPRINT
3435 Maximum size in memory allocated to the SPL, BSS included.
3436 When defined, the linker checks that the actual memory
3437 used by SPL from _start to __bss_end does not exceed it.
3438 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3439 must not be both defined at the same time.
3442 Maximum size of the SPL image (text, data, rodata, and
3443 linker lists sections), BSS excluded.
3444 When defined, the linker checks that the actual size does
3447 CONFIG_SPL_TEXT_BASE
3448 TEXT_BASE for linking the SPL binary.
3450 CONFIG_SPL_RELOC_TEXT_BASE
3451 Address to relocate to. If unspecified, this is equal to
3452 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3454 CONFIG_SPL_BSS_START_ADDR
3455 Link address for the BSS within the SPL binary.
3457 CONFIG_SPL_BSS_MAX_SIZE
3458 Maximum size in memory allocated to the SPL BSS.
3459 When defined, the linker checks that the actual memory used
3460 by SPL from __bss_start to __bss_end does not exceed it.
3461 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3462 must not be both defined at the same time.
3465 Adress of the start of the stack SPL will use
3467 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3468 When defined, SPL will panic() if the image it has
3469 loaded does not have a signature.
3470 Defining this is useful when code which loads images
3471 in SPL cannot guarantee that absolutely all read errors
3473 An example is the LPC32XX MLC NAND driver, which will
3474 consider that a completely unreadable NAND block is bad,
3475 and thus should be skipped silently.
3477 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3478 When defined, SPL will proceed to another boot method
3479 if the image it has loaded does not have a signature.
3481 CONFIG_SPL_RELOC_STACK
3482 Adress of the start of the stack SPL will use after
3483 relocation. If unspecified, this is equal to
3486 CONFIG_SYS_SPL_MALLOC_START
3487 Starting address of the malloc pool used in SPL.
3488 When this option is set the full malloc is used in SPL and
3489 it is set up by spl_init() and before that, the simple malloc()
3490 can be used if CONFIG_SYS_MALLOC_F is defined.
3492 CONFIG_SYS_SPL_MALLOC_SIZE
3493 The size of the malloc pool used in SPL.
3495 CONFIG_SPL_FRAMEWORK
3496 Enable the SPL framework under common/. This framework
3497 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3498 NAND loading of the Linux Kernel.
3501 Enable booting directly to an OS from SPL.
3502 See also: doc/README.falcon
3504 CONFIG_SPL_DISPLAY_PRINT
3505 For ARM, enable an optional function to print more information
3506 about the running system.
3508 CONFIG_SPL_INIT_MINIMAL
3509 Arch init code should be built for a very small image
3511 CONFIG_SPL_LIBCOMMON_SUPPORT
3512 Support for common/libcommon.o in SPL binary
3514 CONFIG_SPL_LIBDISK_SUPPORT
3515 Support for disk/libdisk.o in SPL binary
3517 CONFIG_SPL_I2C_SUPPORT
3518 Support for drivers/i2c/libi2c.o in SPL binary
3520 CONFIG_SPL_GPIO_SUPPORT
3521 Support for drivers/gpio/libgpio.o in SPL binary
3523 CONFIG_SPL_MMC_SUPPORT
3524 Support for drivers/mmc/libmmc.o in SPL binary
3526 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3527 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3528 Address and partition on the MMC to load U-Boot from
3529 when the MMC is being used in raw mode.
3531 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3532 Partition on the MMC to load U-Boot from when the MMC is being
3535 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3536 Sector to load kernel uImage from when MMC is being
3537 used in raw mode (for Falcon mode)
3539 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3540 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3541 Sector and number of sectors to load kernel argument
3542 parameters from when MMC is being used in raw mode
3545 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3546 Partition on the MMC to load U-Boot from when the MMC is being
3549 CONFIG_SPL_FAT_SUPPORT
3550 Support for fs/fat/libfat.o in SPL binary
3552 CONFIG_SPL_EXT_SUPPORT
3553 Support for EXT filesystem in SPL binary
3555 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3556 Filename to read to load U-Boot when reading from filesystem
3558 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3559 Filename to read to load kernel uImage when reading
3560 from filesystem (for Falcon mode)
3562 CONFIG_SPL_FS_LOAD_ARGS_NAME
3563 Filename to read to load kernel argument parameters
3564 when reading from filesystem (for Falcon mode)
3566 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3567 Set this for NAND SPL on PPC mpc83xx targets, so that
3568 start.S waits for the rest of the SPL to load before
3569 continuing (the hardware starts execution after just
3570 loading the first page rather than the full 4K).
3572 CONFIG_SPL_SKIP_RELOCATE
3573 Avoid SPL relocation
3575 CONFIG_SPL_NAND_BASE
3576 Include nand_base.c in the SPL. Requires
3577 CONFIG_SPL_NAND_DRIVERS.
3579 CONFIG_SPL_NAND_DRIVERS
3580 SPL uses normal NAND drivers, not minimal drivers.
3583 Include standard software ECC in the SPL
3585 CONFIG_SPL_NAND_SIMPLE
3586 Support for NAND boot using simple NAND drivers that
3587 expose the cmd_ctrl() interface.
3590 Support for a lightweight UBI (fastmap) scanner and
3593 CONFIG_SPL_MTD_SUPPORT
3594 Support for the MTD subsystem within SPL. Useful for
3595 environment on NAND support within SPL.
3597 CONFIG_SPL_NAND_RAW_ONLY
3598 Support to boot only raw u-boot.bin images. Use this only
3599 if you need to save space.
3601 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3602 Set for the SPL on PPC mpc8xxx targets, support for
3603 drivers/ddr/fsl/libddr.o in SPL binary.
3605 CONFIG_SPL_COMMON_INIT_DDR
3606 Set for common ddr init with serial presence detect in
3609 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3610 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3611 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3612 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3613 CONFIG_SYS_NAND_ECCBYTES
3614 Defines the size and behavior of the NAND that SPL uses
3617 CONFIG_SPL_NAND_BOOT
3618 Add support NAND boot
3620 CONFIG_SYS_NAND_U_BOOT_OFFS
3621 Location in NAND to read U-Boot from
3623 CONFIG_SYS_NAND_U_BOOT_DST
3624 Location in memory to load U-Boot to
3626 CONFIG_SYS_NAND_U_BOOT_SIZE
3627 Size of image to load
3629 CONFIG_SYS_NAND_U_BOOT_START
3630 Entry point in loaded image to jump to
3632 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3633 Define this if you need to first read the OOB and then the
3634 data. This is used, for example, on davinci platforms.
3636 CONFIG_SPL_OMAP3_ID_NAND
3637 Support for an OMAP3-specific set of functions to return the
3638 ID and MFR of the first attached NAND chip, if present.
3640 CONFIG_SPL_SERIAL_SUPPORT
3641 Support for drivers/serial/libserial.o in SPL binary
3643 CONFIG_SPL_SPI_FLASH_SUPPORT
3644 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3646 CONFIG_SPL_SPI_SUPPORT
3647 Support for drivers/spi/libspi.o in SPL binary
3649 CONFIG_SPL_RAM_DEVICE
3650 Support for running image already present in ram, in SPL binary
3652 CONFIG_SPL_LIBGENERIC_SUPPORT
3653 Support for lib/libgeneric.o in SPL binary
3655 CONFIG_SPL_ENV_SUPPORT
3656 Support for the environment operating in SPL binary
3658 CONFIG_SPL_NET_SUPPORT
3659 Support for the net/libnet.o in SPL binary.
3660 It conflicts with SPL env from storage medium specified by
3661 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3664 Image offset to which the SPL should be padded before appending
3665 the SPL payload. By default, this is defined as
3666 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3667 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3668 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3671 Final target image containing SPL and payload. Some SPLs
3672 use an arch-specific makefile fragment instead, for
3673 example if more than one image needs to be produced.
3675 CONFIG_FIT_SPL_PRINT
3676 Printing information about a FIT image adds quite a bit of
3677 code to SPL. So this is normally disabled in SPL. Use this
3678 option to re-enable it. This will affect the output of the
3679 bootm command when booting a FIT image.
3683 Enable building of TPL globally.
3686 Image offset to which the TPL should be padded before appending
3687 the TPL payload. By default, this is defined as
3688 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3689 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3690 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3692 - Interrupt support (PPC):
3694 There are common interrupt_init() and timer_interrupt()
3695 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3696 for CPU specific initialization. interrupt_init_cpu()
3697 should set decrementer_count to appropriate value. If
3698 CPU resets decrementer automatically after interrupt
3699 (ppc4xx) it should set decrementer_count to zero.
3700 timer_interrupt() calls timer_interrupt_cpu() for CPU
3701 specific handling. If board has watchdog / status_led
3702 / other_activity_monitor it works automatically from
3703 general timer_interrupt().
3706 Board initialization settings:
3707 ------------------------------
3709 During Initialization u-boot calls a number of board specific functions
3710 to allow the preparation of board specific prerequisites, e.g. pin setup
3711 before drivers are initialized. To enable these callbacks the
3712 following configuration macros have to be defined. Currently this is
3713 architecture specific, so please check arch/your_architecture/lib/board.c
3714 typically in board_init_f() and board_init_r().
3716 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3717 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3718 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3719 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3721 Configuration Settings:
3722 -----------------------
3724 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3725 Optionally it can be defined to support 64-bit memory commands.
3727 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3728 undefine this when you're short of memory.
3730 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3731 width of the commands listed in the 'help' command output.
3733 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3734 prompt for user input.
3736 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3738 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3740 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3742 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3743 the application (usually a Linux kernel) when it is
3746 - CONFIG_SYS_BAUDRATE_TABLE:
3747 List of legal baudrate settings for this board.
3749 - CONFIG_SYS_CONSOLE_INFO_QUIET
3750 Suppress display of console information at boot.
3752 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3753 If the board specific function
3754 extern int overwrite_console (void);
3755 returns 1, the stdin, stderr and stdout are switched to the
3756 serial port, else the settings in the environment are used.
3758 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3759 Enable the call to overwrite_console().
3761 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3762 Enable overwrite of previous console environment settings.
3764 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3765 Begin and End addresses of the area used by the
3768 - CONFIG_SYS_ALT_MEMTEST:
3769 Enable an alternate, more extensive memory test.
3771 - CONFIG_SYS_MEMTEST_SCRATCH:
3772 Scratch address used by the alternate memory test
3773 You only need to set this if address zero isn't writeable
3775 - CONFIG_SYS_MEM_RESERVE_SECURE
3776 Only implemented for ARMv8 for now.
3777 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3778 is substracted from total RAM and won't be reported to OS.
3779 This memory can be used as secure memory. A variable
3780 gd->arch.secure_ram is used to track the location. In systems
3781 the RAM base is not zero, or RAM is divided into banks,
3782 this variable needs to be recalcuated to get the address.
3784 - CONFIG_SYS_MEM_TOP_HIDE:
3785 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3786 this specified memory area will get subtracted from the top
3787 (end) of RAM and won't get "touched" at all by U-Boot. By
3788 fixing up gd->ram_size the Linux kernel should gets passed
3789 the now "corrected" memory size and won't touch it either.
3790 This should work for arch/ppc and arch/powerpc. Only Linux
3791 board ports in arch/powerpc with bootwrapper support that
3792 recalculate the memory size from the SDRAM controller setup
3793 will have to get fixed in Linux additionally.
3795 This option can be used as a workaround for the 440EPx/GRx
3796 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3799 WARNING: Please make sure that this value is a multiple of
3800 the Linux page size (normally 4k). If this is not the case,
3801 then the end address of the Linux memory will be located at a
3802 non page size aligned address and this could cause major
3805 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3806 Enable temporary baudrate change while serial download
3808 - CONFIG_SYS_SDRAM_BASE:
3809 Physical start address of SDRAM. _Must_ be 0 here.
3811 - CONFIG_SYS_MBIO_BASE:
3812 Physical start address of Motherboard I/O (if using a
3815 - CONFIG_SYS_FLASH_BASE:
3816 Physical start address of Flash memory.
3818 - CONFIG_SYS_MONITOR_BASE:
3819 Physical start address of boot monitor code (set by
3820 make config files to be same as the text base address
3821 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3822 CONFIG_SYS_FLASH_BASE when booting from flash.
3824 - CONFIG_SYS_MONITOR_LEN:
3825 Size of memory reserved for monitor code, used to
3826 determine _at_compile_time_ (!) if the environment is
3827 embedded within the U-Boot image, or in a separate
3830 - CONFIG_SYS_MALLOC_LEN:
3831 Size of DRAM reserved for malloc() use.
3833 - CONFIG_SYS_MALLOC_F_LEN
3834 Size of the malloc() pool for use before relocation. If
3835 this is defined, then a very simple malloc() implementation
3836 will become available before relocation. The address is just
3837 below the global data, and the stack is moved down to make
3840 This feature allocates regions with increasing addresses
3841 within the region. calloc() is supported, but realloc()
3842 is not available. free() is supported but does nothing.
3843 The memory will be freed (or in fact just forgotten) when
3844 U-Boot relocates itself.
3846 - CONFIG_SYS_MALLOC_SIMPLE
3847 Provides a simple and small malloc() and calloc() for those
3848 boards which do not use the full malloc in SPL (which is
3849 enabled with CONFIG_SYS_SPL_MALLOC_START).
3851 - CONFIG_SYS_NONCACHED_MEMORY:
3852 Size of non-cached memory area. This area of memory will be
3853 typically located right below the malloc() area and mapped
3854 uncached in the MMU. This is useful for drivers that would
3855 otherwise require a lot of explicit cache maintenance. For
3856 some drivers it's also impossible to properly maintain the
3857 cache. For example if the regions that need to be flushed
3858 are not a multiple of the cache-line size, *and* padding
3859 cannot be allocated between the regions to align them (i.e.
3860 if the HW requires a contiguous array of regions, and the
3861 size of each region is not cache-aligned), then a flush of
3862 one region may result in overwriting data that hardware has
3863 written to another region in the same cache-line. This can
3864 happen for example in network drivers where descriptors for
3865 buffers are typically smaller than the CPU cache-line (e.g.
3866 16 bytes vs. 32 or 64 bytes).
3868 Non-cached memory is only supported on 32-bit ARM at present.
3870 - CONFIG_SYS_BOOTM_LEN:
3871 Normally compressed uImages are limited to an
3872 uncompressed size of 8 MBytes. If this is not enough,
3873 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3874 to adjust this setting to your needs.
3876 - CONFIG_SYS_BOOTMAPSZ:
3877 Maximum size of memory mapped by the startup code of
3878 the Linux kernel; all data that must be processed by
3879 the Linux kernel (bd_info, boot arguments, FDT blob if
3880 used) must be put below this limit, unless "bootm_low"
3881 environment variable is defined and non-zero. In such case
3882 all data for the Linux kernel must be between "bootm_low"
3883 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3884 variable "bootm_mapsize" will override the value of
3885 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3886 then the value in "bootm_size" will be used instead.
3888 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3889 Enable initrd_high functionality. If defined then the
3890 initrd_high feature is enabled and the bootm ramdisk subcommand
3893 - CONFIG_SYS_BOOT_GET_CMDLINE:
3894 Enables allocating and saving kernel cmdline in space between
3895 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3897 - CONFIG_SYS_BOOT_GET_KBD:
3898 Enables allocating and saving a kernel copy of the bd_info in
3899 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3901 - CONFIG_SYS_MAX_FLASH_BANKS:
3902 Max number of Flash memory banks
3904 - CONFIG_SYS_MAX_FLASH_SECT:
3905 Max number of sectors on a Flash chip
3907 - CONFIG_SYS_FLASH_ERASE_TOUT:
3908 Timeout for Flash erase operations (in ms)
3910 - CONFIG_SYS_FLASH_WRITE_TOUT:
3911 Timeout for Flash write operations (in ms)
3913 - CONFIG_SYS_FLASH_LOCK_TOUT
3914 Timeout for Flash set sector lock bit operation (in ms)
3916 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3917 Timeout for Flash clear lock bits operation (in ms)
3919 - CONFIG_SYS_FLASH_PROTECTION
3920 If defined, hardware flash sectors protection is used
3921 instead of U-Boot software protection.
3923 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3925 Enable TFTP transfers directly to flash memory;
3926 without this option such a download has to be
3927 performed in two steps: (1) download to RAM, and (2)
3928 copy from RAM to flash.
3930 The two-step approach is usually more reliable, since
3931 you can check if the download worked before you erase
3932 the flash, but in some situations (when system RAM is
3933 too limited to allow for a temporary copy of the
3934 downloaded image) this option may be very useful.
3936 - CONFIG_SYS_FLASH_CFI:
3937 Define if the flash driver uses extra elements in the
3938 common flash structure for storing flash geometry.
3940 - CONFIG_FLASH_CFI_DRIVER
3941 This option also enables the building of the cfi_flash driver
3942 in the drivers directory
3944 - CONFIG_FLASH_CFI_MTD
3945 This option enables the building of the cfi_mtd driver
3946 in the drivers directory. The driver exports CFI flash
3949 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3950 Use buffered writes to flash.
3952 - CONFIG_FLASH_SPANSION_S29WS_N
3953 s29ws-n MirrorBit flash has non-standard addresses for buffered
3956 - CONFIG_SYS_FLASH_QUIET_TEST
3957 If this option is defined, the common CFI flash doesn't
3958 print it's warning upon not recognized FLASH banks. This
3959 is useful, if some of the configured banks are only
3960 optionally available.
3962 - CONFIG_FLASH_SHOW_PROGRESS
3963 If defined (must be an integer), print out countdown
3964 digits and dots. Recommended value: 45 (9..1) for 80
3965 column displays, 15 (3..1) for 40 column displays.
3967 - CONFIG_FLASH_VERIFY
3968 If defined, the content of the flash (destination) is compared
3969 against the source after the write operation. An error message
3970 will be printed when the contents are not identical.
3971 Please note that this option is useless in nearly all cases,
3972 since such flash programming errors usually are detected earlier
3973 while unprotecting/erasing/programming. Please only enable
3974 this option if you really know what you are doing.
3976 - CONFIG_SYS_RX_ETH_BUFFER:
3977 Defines the number of Ethernet receive buffers. On some
3978 Ethernet controllers it is recommended to set this value
3979 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3980 buffers can be full shortly after enabling the interface
3981 on high Ethernet traffic.
3982 Defaults to 4 if not defined.
3984 - CONFIG_ENV_MAX_ENTRIES
3986 Maximum number of entries in the hash table that is used
3987 internally to store the environment settings. The default
3988 setting is supposed to be generous and should work in most
3989 cases. This setting can be used to tune behaviour; see
3990 lib/hashtable.c for details.
3992 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3993 - CONFIG_ENV_FLAGS_LIST_STATIC
3994 Enable validation of the values given to environment variables when
3995 calling env set. Variables can be restricted to only decimal,
3996 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3997 the variables can also be restricted to IP address or MAC address.
3999 The format of the list is:
4000 type_attribute = [s|d|x|b|i|m]
4001 access_attribute = [a|r|o|c]
4002 attributes = type_attribute[access_attribute]
4003 entry = variable_name[:attributes]
4006 The type attributes are:
4007 s - String (default)
4010 b - Boolean ([1yYtT|0nNfF])
4014 The access attributes are:
4020 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4021 Define this to a list (string) to define the ".flags"
4022 environment variable in the default or embedded environment.
4024 - CONFIG_ENV_FLAGS_LIST_STATIC
4025 Define this to a list (string) to define validation that
4026 should be done if an entry is not found in the ".flags"
4027 environment variable. To override a setting in the static
4028 list, simply add an entry for the same variable name to the
4031 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4032 regular expression. This allows multiple variables to define the same
4033 flags without explicitly listing them for each variable.
4035 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4036 If defined, don't allow the -f switch to env set override variable
4039 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4040 This is set by OMAP boards for the max time that reset should
4041 be asserted. See doc/README.omap-reset-time for details on how
4042 the value can be calculated on a given board.
4045 If stdint.h is available with your toolchain you can define this
4046 option to enable it. You can provide option 'USE_STDINT=1' when
4047 building U-Boot to enable this.
4049 The following definitions that deal with the placement and management
4050 of environment data (variable area); in general, we support the
4051 following configurations:
4053 - CONFIG_BUILD_ENVCRC:
4055 Builds up envcrc with the target environment so that external utils
4056 may easily extract it and embed it in final U-Boot images.
4058 - CONFIG_ENV_IS_IN_FLASH:
4060 Define this if the environment is in flash memory.
4062 a) The environment occupies one whole flash sector, which is
4063 "embedded" in the text segment with the U-Boot code. This
4064 happens usually with "bottom boot sector" or "top boot
4065 sector" type flash chips, which have several smaller
4066 sectors at the start or the end. For instance, such a
4067 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4068 such a case you would place the environment in one of the
4069 4 kB sectors - with U-Boot code before and after it. With
4070 "top boot sector" type flash chips, you would put the
4071 environment in one of the last sectors, leaving a gap
4072 between U-Boot and the environment.
4074 - CONFIG_ENV_OFFSET:
4076 Offset of environment data (variable area) to the
4077 beginning of flash memory; for instance, with bottom boot
4078 type flash chips the second sector can be used: the offset
4079 for this sector is given here.
4081 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4085 This is just another way to specify the start address of
4086 the flash sector containing the environment (instead of
4089 - CONFIG_ENV_SECT_SIZE:
4091 Size of the sector containing the environment.
4094 b) Sometimes flash chips have few, equal sized, BIG sectors.
4095 In such a case you don't want to spend a whole sector for
4100 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4101 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4102 of this flash sector for the environment. This saves
4103 memory for the RAM copy of the environment.
4105 It may also save flash memory if you decide to use this
4106 when your environment is "embedded" within U-Boot code,
4107 since then the remainder of the flash sector could be used
4108 for U-Boot code. It should be pointed out that this is
4109 STRONGLY DISCOURAGED from a robustness point of view:
4110 updating the environment in flash makes it always
4111 necessary to erase the WHOLE sector. If something goes
4112 wrong before the contents has been restored from a copy in
4113 RAM, your target system will be dead.
4115 - CONFIG_ENV_ADDR_REDUND
4116 CONFIG_ENV_SIZE_REDUND
4118 These settings describe a second storage area used to hold
4119 a redundant copy of the environment data, so that there is
4120 a valid backup copy in case there is a power failure during
4121 a "saveenv" operation.
4123 BE CAREFUL! Any changes to the flash layout, and some changes to the
4124 source code will make it necessary to adapt <board>/u-boot.lds*
4128 - CONFIG_ENV_IS_IN_NVRAM:
4130 Define this if you have some non-volatile memory device
4131 (NVRAM, battery buffered SRAM) which you want to use for the
4137 These two #defines are used to determine the memory area you
4138 want to use for environment. It is assumed that this memory
4139 can just be read and written to, without any special
4142 BE CAREFUL! The first access to the environment happens quite early
4143 in U-Boot initialization (when we try to get the setting of for the
4144 console baudrate). You *MUST* have mapped your NVRAM area then, or
4147 Please note that even with NVRAM we still use a copy of the
4148 environment in RAM: we could work on NVRAM directly, but we want to
4149 keep settings there always unmodified except somebody uses "saveenv"
4150 to save the current settings.
4153 - CONFIG_ENV_IS_IN_EEPROM:
4155 Use this if you have an EEPROM or similar serial access
4156 device and a driver for it.
4158 - CONFIG_ENV_OFFSET:
4161 These two #defines specify the offset and size of the
4162 environment area within the total memory of your EEPROM.
4164 - CONFIG_SYS_I2C_EEPROM_ADDR:
4165 If defined, specified the chip address of the EEPROM device.
4166 The default address is zero.
4168 - CONFIG_SYS_I2C_EEPROM_BUS:
4169 If defined, specified the i2c bus of the EEPROM device.
4171 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4172 If defined, the number of bits used to address bytes in a
4173 single page in the EEPROM device. A 64 byte page, for example
4174 would require six bits.
4176 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4177 If defined, the number of milliseconds to delay between
4178 page writes. The default is zero milliseconds.
4180 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4181 The length in bytes of the EEPROM memory array address. Note
4182 that this is NOT the chip address length!
4184 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4185 EEPROM chips that implement "address overflow" are ones
4186 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4187 address and the extra bits end up in the "chip address" bit
4188 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4191 Note that we consider the length of the address field to
4192 still be one byte because the extra address bits are hidden
4193 in the chip address.
4195 - CONFIG_SYS_EEPROM_SIZE:
4196 The size in bytes of the EEPROM device.
4198 - CONFIG_ENV_EEPROM_IS_ON_I2C
4199 define this, if you have I2C and SPI activated, and your
4200 EEPROM, which holds the environment, is on the I2C bus.
4202 - CONFIG_I2C_ENV_EEPROM_BUS
4203 if you have an Environment on an EEPROM reached over
4204 I2C muxes, you can define here, how to reach this
4205 EEPROM. For example:
4207 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4209 EEPROM which holds the environment, is reached over
4210 a pca9547 i2c mux with address 0x70, channel 3.
4212 - CONFIG_ENV_IS_IN_DATAFLASH:
4214 Define this if you have a DataFlash memory device which you
4215 want to use for the environment.
4217 - CONFIG_ENV_OFFSET:
4221 These three #defines specify the offset and size of the
4222 environment area within the total memory of your DataFlash placed
4223 at the specified address.
4225 - CONFIG_ENV_IS_IN_SPI_FLASH:
4227 Define this if you have a SPI Flash memory device which you
4228 want to use for the environment.
4230 - CONFIG_ENV_OFFSET:
4233 These two #defines specify the offset and size of the
4234 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4235 aligned to an erase sector boundary.
4237 - CONFIG_ENV_SECT_SIZE:
4239 Define the SPI flash's sector size.
4241 - CONFIG_ENV_OFFSET_REDUND (optional):
4243 This setting describes a second storage area of CONFIG_ENV_SIZE
4244 size used to hold a redundant copy of the environment data, so
4245 that there is a valid backup copy in case there is a power failure
4246 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4247 aligned to an erase sector boundary.
4249 - CONFIG_ENV_SPI_BUS (optional):
4250 - CONFIG_ENV_SPI_CS (optional):
4252 Define the SPI bus and chip select. If not defined they will be 0.
4254 - CONFIG_ENV_SPI_MAX_HZ (optional):
4256 Define the SPI max work clock. If not defined then use 1MHz.
4258 - CONFIG_ENV_SPI_MODE (optional):
4260 Define the SPI work mode. If not defined then use SPI_MODE_3.
4262 - CONFIG_ENV_IS_IN_REMOTE:
4264 Define this if you have a remote memory space which you
4265 want to use for the local device's environment.
4270 These two #defines specify the address and size of the
4271 environment area within the remote memory space. The
4272 local device can get the environment from remote memory
4273 space by SRIO or PCIE links.
4275 BE CAREFUL! For some special cases, the local device can not use
4276 "saveenv" command. For example, the local device will get the
4277 environment stored in a remote NOR flash by SRIO or PCIE link,
4278 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4280 - CONFIG_ENV_IS_IN_NAND:
4282 Define this if you have a NAND device which you want to use
4283 for the environment.
4285 - CONFIG_ENV_OFFSET:
4288 These two #defines specify the offset and size of the environment
4289 area within the first NAND device. CONFIG_ENV_OFFSET must be
4290 aligned to an erase block boundary.
4292 - CONFIG_ENV_OFFSET_REDUND (optional):
4294 This setting describes a second storage area of CONFIG_ENV_SIZE
4295 size used to hold a redundant copy of the environment data, so
4296 that there is a valid backup copy in case there is a power failure
4297 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4298 aligned to an erase block boundary.
4300 - CONFIG_ENV_RANGE (optional):
4302 Specifies the length of the region in which the environment
4303 can be written. This should be a multiple of the NAND device's
4304 block size. Specifying a range with more erase blocks than
4305 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4306 the range to be avoided.
4308 - CONFIG_ENV_OFFSET_OOB (optional):
4310 Enables support for dynamically retrieving the offset of the
4311 environment from block zero's out-of-band data. The
4312 "nand env.oob" command can be used to record this offset.
4313 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4314 using CONFIG_ENV_OFFSET_OOB.
4316 - CONFIG_NAND_ENV_DST
4318 Defines address in RAM to which the nand_spl code should copy the
4319 environment. If redundant environment is used, it will be copied to
4320 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4322 - CONFIG_ENV_IS_IN_UBI:
4324 Define this if you have an UBI volume that you want to use for the
4325 environment. This has the benefit of wear-leveling the environment
4326 accesses, which is important on NAND.
4328 - CONFIG_ENV_UBI_PART:
4330 Define this to a string that is the mtd partition containing the UBI.
4332 - CONFIG_ENV_UBI_VOLUME:
4334 Define this to the name of the volume that you want to store the
4337 - CONFIG_ENV_UBI_VOLUME_REDUND:
4339 Define this to the name of another volume to store a second copy of
4340 the environment in. This will enable redundant environments in UBI.
4341 It is assumed that both volumes are in the same MTD partition.
4343 - CONFIG_UBI_SILENCE_MSG
4344 - CONFIG_UBIFS_SILENCE_MSG
4346 You will probably want to define these to avoid a really noisy system
4347 when storing the env in UBI.
4349 - CONFIG_ENV_IS_IN_FAT:
4350 Define this if you want to use the FAT file system for the environment.
4352 - FAT_ENV_INTERFACE:
4354 Define this to a string that is the name of the block device.
4356 - FAT_ENV_DEV_AND_PART:
4358 Define this to a string to specify the partition of the device. It can
4361 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4362 - "D:P": device D partition P. Error occurs if device D has no
4365 - "D" or "D:": device D partition 1 if device D has partition
4366 table, or the whole device D if has no partition
4368 - "D:auto": first partition in device D with bootable flag set.
4369 If none, first valid partition in device D. If no
4370 partition table then means device D.
4374 It's a string of the FAT file name. This file use to store the
4378 This should be defined. Otherwise it cannot save the environment file.
4380 - CONFIG_ENV_IS_IN_MMC:
4382 Define this if you have an MMC device which you want to use for the
4385 - CONFIG_SYS_MMC_ENV_DEV:
4387 Specifies which MMC device the environment is stored in.
4389 - CONFIG_SYS_MMC_ENV_PART (optional):
4391 Specifies which MMC partition the environment is stored in. If not
4392 set, defaults to partition 0, the user area. Common values might be
4393 1 (first MMC boot partition), 2 (second MMC boot partition).
4395 - CONFIG_ENV_OFFSET:
4398 These two #defines specify the offset and size of the environment
4399 area within the specified MMC device.
4401 If offset is positive (the usual case), it is treated as relative to
4402 the start of the MMC partition. If offset is negative, it is treated
4403 as relative to the end of the MMC partition. This can be useful if
4404 your board may be fitted with different MMC devices, which have
4405 different sizes for the MMC partitions, and you always want the
4406 environment placed at the very end of the partition, to leave the
4407 maximum possible space before it, to store other data.
4409 These two values are in units of bytes, but must be aligned to an
4410 MMC sector boundary.
4412 - CONFIG_ENV_OFFSET_REDUND (optional):
4414 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4415 hold a redundant copy of the environment data. This provides a
4416 valid backup copy in case the other copy is corrupted, e.g. due
4417 to a power failure during a "saveenv" operation.
4419 This value may also be positive or negative; this is handled in the
4420 same way as CONFIG_ENV_OFFSET.
4422 This value is also in units of bytes, but must also be aligned to
4423 an MMC sector boundary.
4425 - CONFIG_ENV_SIZE_REDUND (optional):
4427 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4428 set. If this value is set, it must be set to the same value as
4431 - CONFIG_SYS_SPI_INIT_OFFSET
4433 Defines offset to the initial SPI buffer area in DPRAM. The
4434 area is used at an early stage (ROM part) if the environment
4435 is configured to reside in the SPI EEPROM: We need a 520 byte
4436 scratch DPRAM area. It is used between the two initialization
4437 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4438 to be a good choice since it makes it far enough from the
4439 start of the data area as well as from the stack pointer.
4441 Please note that the environment is read-only until the monitor
4442 has been relocated to RAM and a RAM copy of the environment has been
4443 created; also, when using EEPROM you will have to use getenv_f()
4444 until then to read environment variables.
4446 The environment is protected by a CRC32 checksum. Before the monitor
4447 is relocated into RAM, as a result of a bad CRC you will be working
4448 with the compiled-in default environment - *silently*!!! [This is
4449 necessary, because the first environment variable we need is the
4450 "baudrate" setting for the console - if we have a bad CRC, we don't
4451 have any device yet where we could complain.]
4453 Note: once the monitor has been relocated, then it will complain if
4454 the default environment is used; a new CRC is computed as soon as you
4455 use the "saveenv" command to store a valid environment.
4457 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4458 Echo the inverted Ethernet link state to the fault LED.
4460 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4461 also needs to be defined.
4463 - CONFIG_SYS_FAULT_MII_ADDR:
4464 MII address of the PHY to check for the Ethernet link state.
4466 - CONFIG_NS16550_MIN_FUNCTIONS:
4467 Define this if you desire to only have use of the NS16550_init
4468 and NS16550_putc functions for the serial driver located at
4469 drivers/serial/ns16550.c. This option is useful for saving
4470 space for already greatly restricted images, including but not
4471 limited to NAND_SPL configurations.
4473 - CONFIG_DISPLAY_BOARDINFO
4474 Display information about the board that U-Boot is running on
4475 when U-Boot starts up. The board function checkboard() is called
4478 - CONFIG_DISPLAY_BOARDINFO_LATE
4479 Similar to the previous option, but display this information
4480 later, once stdio is running and output goes to the LCD, if
4483 - CONFIG_BOARD_SIZE_LIMIT:
4484 Maximum size of the U-Boot image. When defined, the
4485 build system checks that the actual size does not
4488 Low Level (hardware related) configuration options:
4489 ---------------------------------------------------
4491 - CONFIG_SYS_CACHELINE_SIZE:
4492 Cache Line Size of the CPU.
4494 - CONFIG_SYS_DEFAULT_IMMR:
4495 Default address of the IMMR after system reset.
4497 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4498 and RPXsuper) to be able to adjust the position of
4499 the IMMR register after a reset.
4501 - CONFIG_SYS_CCSRBAR_DEFAULT:
4502 Default (power-on reset) physical address of CCSR on Freescale
4505 - CONFIG_SYS_CCSRBAR:
4506 Virtual address of CCSR. On a 32-bit build, this is typically
4507 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4509 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4510 for cross-platform code that uses that macro instead.
4512 - CONFIG_SYS_CCSRBAR_PHYS:
4513 Physical address of CCSR. CCSR can be relocated to a new
4514 physical address, if desired. In this case, this macro should
4515 be set to that address. Otherwise, it should be set to the
4516 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4517 is typically relocated on 36-bit builds. It is recommended
4518 that this macro be defined via the _HIGH and _LOW macros:
4520 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4521 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4523 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4524 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4525 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4526 used in assembly code, so it must not contain typecasts or
4527 integer size suffixes (e.g. "ULL").
4529 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4530 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4531 used in assembly code, so it must not contain typecasts or
4532 integer size suffixes (e.g. "ULL").
4534 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4535 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4536 forced to a value that ensures that CCSR is not relocated.
4538 - Floppy Disk Support:
4539 CONFIG_SYS_FDC_DRIVE_NUMBER
4541 the default drive number (default value 0)
4543 CONFIG_SYS_ISA_IO_STRIDE
4545 defines the spacing between FDC chipset registers
4548 CONFIG_SYS_ISA_IO_OFFSET
4550 defines the offset of register from address. It
4551 depends on which part of the data bus is connected to
4552 the FDC chipset. (default value 0)
4554 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4555 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4558 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4559 fdc_hw_init() is called at the beginning of the FDC
4560 setup. fdc_hw_init() must be provided by the board
4561 source code. It is used to make hardware-dependent
4565 Most IDE controllers were designed to be connected with PCI
4566 interface. Only few of them were designed for AHB interface.
4567 When software is doing ATA command and data transfer to
4568 IDE devices through IDE-AHB controller, some additional
4569 registers accessing to these kind of IDE-AHB controller
4572 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4573 DO NOT CHANGE unless you know exactly what you're
4574 doing! (11-4) [MPC8xx/82xx systems only]
4576 - CONFIG_SYS_INIT_RAM_ADDR:
4578 Start address of memory area that can be used for
4579 initial data and stack; please note that this must be
4580 writable memory that is working WITHOUT special
4581 initialization, i. e. you CANNOT use normal RAM which
4582 will become available only after programming the
4583 memory controller and running certain initialization
4586 U-Boot uses the following memory types:
4587 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4588 - MPC824X: data cache
4589 - PPC4xx: data cache
4591 - CONFIG_SYS_GBL_DATA_OFFSET:
4593 Offset of the initial data structure in the memory
4594 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4595 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4596 data is located at the end of the available space
4597 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4598 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4599 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4600 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4603 On the MPC824X (or other systems that use the data
4604 cache for initial memory) the address chosen for
4605 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4606 point to an otherwise UNUSED address space between
4607 the top of RAM and the start of the PCI space.
4609 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4611 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4613 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4615 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4617 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4619 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4621 - CONFIG_SYS_OR_TIMING_SDRAM:
4624 - CONFIG_SYS_MAMR_PTA:
4625 periodic timer for refresh
4627 - CONFIG_SYS_DER: Debug Event Register (37-47)
4629 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4630 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4631 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4632 CONFIG_SYS_BR1_PRELIM:
4633 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4635 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4636 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4637 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4638 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4640 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4641 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4642 Machine Mode Register and Memory Periodic Timer
4643 Prescaler definitions (SDRAM timing)
4645 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4646 enable I2C microcode relocation patch (MPC8xx);
4647 define relocation offset in DPRAM [DSP2]
4649 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4650 enable SMC microcode relocation patch (MPC8xx);
4651 define relocation offset in DPRAM [SMC1]
4653 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4654 enable SPI microcode relocation patch (MPC8xx);
4655 define relocation offset in DPRAM [SCC4]
4657 - CONFIG_SYS_USE_OSCCLK:
4658 Use OSCM clock mode on MBX8xx board. Be careful,
4659 wrong setting might damage your board. Read
4660 doc/README.MBX before setting this variable!
4662 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4663 Offset of the bootmode word in DPRAM used by post
4664 (Power On Self Tests). This definition overrides
4665 #define'd default value in commproc.h resp.
4668 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4669 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4670 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4671 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4672 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4673 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4674 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4675 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4676 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4678 - CONFIG_PCI_DISABLE_PCIE:
4679 Disable PCI-Express on systems where it is supported but not
4682 - CONFIG_PCI_ENUM_ONLY
4683 Only scan through and get the devices on the buses.
4684 Don't do any setup work, presumably because someone or
4685 something has already done it, and we don't need to do it
4686 a second time. Useful for platforms that are pre-booted
4687 by coreboot or similar.
4689 - CONFIG_PCI_INDIRECT_BRIDGE:
4690 Enable support for indirect PCI bridges.
4693 Chip has SRIO or not
4696 Board has SRIO 1 port available
4699 Board has SRIO 2 port available
4701 - CONFIG_SRIO_PCIE_BOOT_MASTER
4702 Board can support master function for Boot from SRIO and PCIE
4704 - CONFIG_SYS_SRIOn_MEM_VIRT:
4705 Virtual Address of SRIO port 'n' memory region
4707 - CONFIG_SYS_SRIOn_MEM_PHYS:
4708 Physical Address of SRIO port 'n' memory region
4710 - CONFIG_SYS_SRIOn_MEM_SIZE:
4711 Size of SRIO port 'n' memory region
4713 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4714 Defined to tell the NAND controller that the NAND chip is using
4716 Not all NAND drivers use this symbol.
4717 Example of drivers that use it:
4718 - drivers/mtd/nand/ndfc.c
4719 - drivers/mtd/nand/mxc_nand.c
4721 - CONFIG_SYS_NDFC_EBC0_CFG
4722 Sets the EBC0_CFG register for the NDFC. If not defined
4723 a default value will be used.
4726 Get DDR timing information from an I2C EEPROM. Common
4727 with pluggable memory modules such as SODIMMs
4730 I2C address of the SPD EEPROM
4732 - CONFIG_SYS_SPD_BUS_NUM
4733 If SPD EEPROM is on an I2C bus other than the first
4734 one, specify here. Note that the value must resolve
4735 to something your driver can deal with.
4737 - CONFIG_SYS_DDR_RAW_TIMING
4738 Get DDR timing information from other than SPD. Common with
4739 soldered DDR chips onboard without SPD. DDR raw timing
4740 parameters are extracted from datasheet and hard-coded into
4741 header files or board specific files.
4743 - CONFIG_FSL_DDR_INTERACTIVE
4744 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4746 - CONFIG_FSL_DDR_SYNC_REFRESH
4747 Enable sync of refresh for multiple controllers.
4749 - CONFIG_FSL_DDR_BIST
4750 Enable built-in memory test for Freescale DDR controllers.
4752 - CONFIG_SYS_83XX_DDR_USES_CS0
4753 Only for 83xx systems. If specified, then DDR should
4754 be configured using CS0 and CS1 instead of CS2 and CS3.
4756 - CONFIG_ETHER_ON_FEC[12]
4757 Define to enable FEC[12] on a 8xx series processor.
4759 - CONFIG_FEC[12]_PHY
4760 Define to the hardcoded PHY address which corresponds
4761 to the given FEC; i. e.
4762 #define CONFIG_FEC1_PHY 4
4763 means that the PHY with address 4 is connected to FEC1
4765 When set to -1, means to probe for first available.
4767 - CONFIG_FEC[12]_PHY_NORXERR
4768 The PHY does not have a RXERR line (RMII only).
4769 (so program the FEC to ignore it).
4772 Enable RMII mode for all FECs.
4773 Note that this is a global option, we can't
4774 have one FEC in standard MII mode and another in RMII mode.
4776 - CONFIG_CRC32_VERIFY
4777 Add a verify option to the crc32 command.
4780 => crc32 -v <address> <count> <crc32>
4782 Where address/count indicate a memory area
4783 and crc32 is the correct crc32 which the
4787 Add the "loopw" memory command. This only takes effect if
4788 the memory commands are activated globally (CONFIG_CMD_MEM).
4791 Add the "mdc" and "mwc" memory commands. These are cyclic
4796 This command will print 4 bytes (10,11,12,13) each 500 ms.
4798 => mwc.l 100 12345678 10
4799 This command will write 12345678 to address 100 all 10 ms.
4801 This only takes effect if the memory commands are activated
4802 globally (CONFIG_CMD_MEM).
4804 - CONFIG_SKIP_LOWLEVEL_INIT
4805 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4806 low level initializations (like setting up the memory
4807 controller) are omitted and/or U-Boot does not
4808 relocate itself into RAM.
4810 Normally this variable MUST NOT be defined. The only
4811 exception is when U-Boot is loaded (to RAM) by some
4812 other boot loader or by a debugger which performs
4813 these initializations itself.
4815 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4816 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4817 to be skipped. The normal CP15 init (such as enabling the
4818 instruction cache) is still performed.
4821 Modifies the behaviour of start.S when compiling a loader
4822 that is executed before the actual U-Boot. E.g. when
4823 compiling a NAND SPL.
4826 Modifies the behaviour of start.S when compiling a loader
4827 that is executed after the SPL and before the actual U-Boot.
4828 It is loaded by the SPL.
4830 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4831 Only for 85xx systems. If this variable is specified, the section
4832 .resetvec is not kept and the section .bootpg is placed in the
4833 previous 4k of the .text section.
4835 - CONFIG_ARCH_MAP_SYSMEM
4836 Generally U-Boot (and in particular the md command) uses
4837 effective address. It is therefore not necessary to regard
4838 U-Boot address as virtual addresses that need to be translated
4839 to physical addresses. However, sandbox requires this, since
4840 it maintains its own little RAM buffer which contains all
4841 addressable memory. This option causes some memory accesses
4842 to be mapped through map_sysmem() / unmap_sysmem().
4844 - CONFIG_USE_ARCH_MEMCPY
4845 CONFIG_USE_ARCH_MEMSET
4846 If these options are used a optimized version of memcpy/memset will
4847 be used if available. These functions may be faster under some
4848 conditions but may increase the binary size.
4850 - CONFIG_X86_RESET_VECTOR
4851 If defined, the x86 reset vector code is included. This is not
4852 needed when U-Boot is running from Coreboot.
4855 Defines the MPU clock speed (in MHz).
4857 NOTE : currently only supported on AM335x platforms.
4859 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4860 Enables the RTC32K OSC on AM33xx based plattforms
4862 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4863 Option to disable subpage write in NAND driver
4864 driver that uses this:
4865 drivers/mtd/nand/davinci_nand.c
4867 Freescale QE/FMAN Firmware Support:
4868 -----------------------------------
4870 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4871 loading of "firmware", which is encoded in the QE firmware binary format.
4872 This firmware often needs to be loaded during U-Boot booting, so macros
4873 are used to identify the storage device (NOR flash, SPI, etc) and the address
4876 - CONFIG_SYS_FMAN_FW_ADDR
4877 The address in the storage device where the FMAN microcode is located. The
4878 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4881 - CONFIG_SYS_QE_FW_ADDR
4882 The address in the storage device where the QE microcode is located. The
4883 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4886 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4887 The maximum possible size of the firmware. The firmware binary format
4888 has a field that specifies the actual size of the firmware, but it
4889 might not be possible to read any part of the firmware unless some
4890 local storage is allocated to hold the entire firmware first.
4892 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4893 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4894 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4895 virtual address in NOR flash.
4897 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4898 Specifies that QE/FMAN firmware is located in NAND flash.
4899 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4901 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4902 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4903 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4905 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4906 Specifies that QE/FMAN firmware is located on the primary SPI
4907 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4909 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4910 Specifies that QE/FMAN firmware is located in the remote (master)
4911 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4912 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4913 window->master inbound window->master LAW->the ucode address in
4914 master's memory space.
4916 Freescale Layerscape Management Complex Firmware Support:
4917 ---------------------------------------------------------
4918 The Freescale Layerscape Management Complex (MC) supports the loading of
4920 This firmware often needs to be loaded during U-Boot booting, so macros
4921 are used to identify the storage device (NOR flash, SPI, etc) and the address
4924 - CONFIG_FSL_MC_ENET
4925 Enable the MC driver for Layerscape SoCs.
4927 - CONFIG_SYS_LS_MC_FW_ADDR
4928 The address in the storage device where the firmware is located. The
4929 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4932 - CONFIG_SYS_LS_MC_FW_LENGTH
4933 The maximum possible size of the firmware. The firmware binary format
4934 has a field that specifies the actual size of the firmware, but it
4935 might not be possible to read any part of the firmware unless some
4936 local storage is allocated to hold the entire firmware first.
4938 - CONFIG_SYS_LS_MC_FW_IN_NOR
4939 Specifies that MC firmware is located in NOR flash, mapped as
4940 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4941 virtual address in NOR flash.
4943 Freescale Layerscape Debug Server Support:
4944 -------------------------------------------
4945 The Freescale Layerscape Debug Server Support supports the loading of
4946 "Debug Server firmware" and triggering SP boot-rom.
4947 This firmware often needs to be loaded during U-Boot booting.
4949 - CONFIG_FSL_DEBUG_SERVER
4950 Enable the Debug Server for Layerscape SoCs.
4952 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
4953 Define minimum DDR size required for debug server image
4955 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4956 Define alignment of reserved memory MC requires
4961 In order to achieve reproducible builds, timestamps used in the U-Boot build
4962 process have to be set to a fixed value.
4964 This is done using the SOURCE_DATE_EPOCH environment variable.
4965 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4966 option for U-Boot or an environment variable in U-Boot.
4968 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4970 Building the Software:
4971 ======================
4973 Building U-Boot has been tested in several native build environments
4974 and in many different cross environments. Of course we cannot support
4975 all possibly existing versions of cross development tools in all
4976 (potentially obsolete) versions. In case of tool chain problems we
4977 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4978 which is extensively used to build and test U-Boot.
4980 If you are not using a native environment, it is assumed that you
4981 have GNU cross compiling tools available in your path. In this case,
4982 you must set the environment variable CROSS_COMPILE in your shell.
4983 Note that no changes to the Makefile or any other source files are
4984 necessary. For example using the ELDK on a 4xx CPU, please enter:
4986 $ CROSS_COMPILE=ppc_4xx-
4987 $ export CROSS_COMPILE
4989 Note: If you wish to generate Windows versions of the utilities in
4990 the tools directory you can use the MinGW toolchain
4991 (http://www.mingw.org). Set your HOST tools to the MinGW
4992 toolchain and execute 'make tools'. For example:
4994 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4996 Binaries such as tools/mkimage.exe will be created which can
4997 be executed on computers running Windows.
4999 U-Boot is intended to be simple to build. After installing the
5000 sources you must configure U-Boot for one specific board type. This
5005 where "NAME_defconfig" is the name of one of the existing configu-
5006 rations; see boards.cfg for supported names.
5008 Note: for some board special configuration names may exist; check if
5009 additional information is available from the board vendor; for
5010 instance, the TQM823L systems are available without (standard)
5011 or with LCD support. You can select such additional "features"
5012 when choosing the configuration, i. e.
5014 make TQM823L_defconfig
5015 - will configure for a plain TQM823L, i. e. no LCD support
5017 make TQM823L_LCD_defconfig
5018 - will configure for a TQM823L with U-Boot console on LCD
5023 Finally, type "make all", and you should get some working U-Boot
5024 images ready for download to / installation on your system:
5026 - "u-boot.bin" is a raw binary image
5027 - "u-boot" is an image in ELF binary format
5028 - "u-boot.srec" is in Motorola S-Record format
5030 By default the build is performed locally and the objects are saved
5031 in the source directory. One of the two methods can be used to change
5032 this behavior and build U-Boot to some external directory:
5034 1. Add O= to the make command line invocations:
5036 make O=/tmp/build distclean
5037 make O=/tmp/build NAME_defconfig
5038 make O=/tmp/build all
5040 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5042 export KBUILD_OUTPUT=/tmp/build
5047 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5051 Please be aware that the Makefiles assume you are using GNU make, so
5052 for instance on NetBSD you might need to use "gmake" instead of
5056 If the system board that you have is not listed, then you will need
5057 to port U-Boot to your hardware platform. To do this, follow these
5060 1. Create a new directory to hold your board specific code. Add any
5061 files you need. In your board directory, you will need at least
5062 the "Makefile" and a "<board>.c".
5063 2. Create a new configuration file "include/configs/<board>.h" for
5065 3. If you're porting U-Boot to a new CPU, then also create a new
5066 directory to hold your CPU specific code. Add any files you need.
5067 4. Run "make <board>_defconfig" with your new name.
5068 5. Type "make", and you should get a working "u-boot.srec" file
5069 to be installed on your target system.
5070 6. Debug and solve any problems that might arise.
5071 [Of course, this last step is much harder than it sounds.]
5074 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5075 ==============================================================
5077 If you have modified U-Boot sources (for instance added a new board
5078 or support for new devices, a new CPU, etc.) you are expected to
5079 provide feedback to the other developers. The feedback normally takes
5080 the form of a "patch", i. e. a context diff against a certain (latest
5081 official or latest in the git repository) version of U-Boot sources.
5083 But before you submit such a patch, please verify that your modifi-
5084 cation did not break existing code. At least make sure that *ALL* of
5085 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5086 just run the buildman script (tools/buildman/buildman), which will
5087 configure and build U-Boot for ALL supported system. Be warned, this
5088 will take a while. Please see the buildman README, or run 'buildman -H'
5092 See also "U-Boot Porting Guide" below.
5095 Monitor Commands - Overview:
5096 ============================
5098 go - start application at address 'addr'
5099 run - run commands in an environment variable
5100 bootm - boot application image from memory
5101 bootp - boot image via network using BootP/TFTP protocol
5102 bootz - boot zImage from memory
5103 tftpboot- boot image via network using TFTP protocol
5104 and env variables "ipaddr" and "serverip"
5105 (and eventually "gatewayip")
5106 tftpput - upload a file via network using TFTP protocol
5107 rarpboot- boot image via network using RARP/TFTP protocol
5108 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5109 loads - load S-Record file over serial line
5110 loadb - load binary file over serial line (kermit mode)
5112 mm - memory modify (auto-incrementing)
5113 nm - memory modify (constant address)
5114 mw - memory write (fill)
5116 cmp - memory compare
5117 crc32 - checksum calculation
5118 i2c - I2C sub-system
5119 sspi - SPI utility commands
5120 base - print or set address offset
5121 printenv- print environment variables
5122 setenv - set environment variables
5123 saveenv - save environment variables to persistent storage
5124 protect - enable or disable FLASH write protection
5125 erase - erase FLASH memory
5126 flinfo - print FLASH memory information
5127 nand - NAND memory operations (see doc/README.nand)
5128 bdinfo - print Board Info structure
5129 iminfo - print header information for application image
5130 coninfo - print console devices and informations
5131 ide - IDE sub-system
5132 loop - infinite loop on address range
5133 loopw - infinite write loop on address range
5134 mtest - simple RAM test
5135 icache - enable or disable instruction cache
5136 dcache - enable or disable data cache
5137 reset - Perform RESET of the CPU
5138 echo - echo args to console
5139 version - print monitor version
5140 help - print online help
5141 ? - alias for 'help'
5144 Monitor Commands - Detailed Description:
5145 ========================================
5149 For now: just type "help <command>".
5152 Environment Variables:
5153 ======================
5155 U-Boot supports user configuration using Environment Variables which
5156 can be made persistent by saving to Flash memory.
5158 Environment Variables are set using "setenv", printed using
5159 "printenv", and saved to Flash using "saveenv". Using "setenv"
5160 without a value can be used to delete a variable from the
5161 environment. As long as you don't save the environment you are
5162 working with an in-memory copy. In case the Flash area containing the
5163 environment is erased by accident, a default environment is provided.
5165 Some configuration options can be set using Environment Variables.
5167 List of environment variables (most likely not complete):
5169 baudrate - see CONFIG_BAUDRATE
5171 bootdelay - see CONFIG_BOOTDELAY
5173 bootcmd - see CONFIG_BOOTCOMMAND
5175 bootargs - Boot arguments when booting an RTOS image
5177 bootfile - Name of the image to load with TFTP
5179 bootm_low - Memory range available for image processing in the bootm
5180 command can be restricted. This variable is given as
5181 a hexadecimal number and defines lowest address allowed
5182 for use by the bootm command. See also "bootm_size"
5183 environment variable. Address defined by "bootm_low" is
5184 also the base of the initial memory mapping for the Linux
5185 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5188 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5189 This variable is given as a hexadecimal number and it
5190 defines the size of the memory region starting at base
5191 address bootm_low that is accessible by the Linux kernel
5192 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5193 as the default value if it is defined, and bootm_size is
5196 bootm_size - Memory range available for image processing in the bootm
5197 command can be restricted. This variable is given as
5198 a hexadecimal number and defines the size of the region
5199 allowed for use by the bootm command. See also "bootm_low"
5200 environment variable.
5202 updatefile - Location of the software update file on a TFTP server, used
5203 by the automatic software update feature. Please refer to
5204 documentation in doc/README.update for more details.
5206 autoload - if set to "no" (any string beginning with 'n'),
5207 "bootp" will just load perform a lookup of the
5208 configuration from the BOOTP server, but not try to
5209 load any image using TFTP
5211 autostart - if set to "yes", an image loaded using the "bootp",
5212 "rarpboot", "tftpboot" or "diskboot" commands will
5213 be automatically started (by internally calling
5216 If set to "no", a standalone image passed to the
5217 "bootm" command will be copied to the load address
5218 (and eventually uncompressed), but NOT be started.
5219 This can be used to load and uncompress arbitrary
5222 fdt_high - if set this restricts the maximum address that the
5223 flattened device tree will be copied into upon boot.
5224 For example, if you have a system with 1 GB memory
5225 at physical address 0x10000000, while Linux kernel
5226 only recognizes the first 704 MB as low memory, you
5227 may need to set fdt_high as 0x3C000000 to have the
5228 device tree blob be copied to the maximum address
5229 of the 704 MB low memory, so that Linux kernel can
5230 access it during the boot procedure.
5232 If this is set to the special value 0xFFFFFFFF then
5233 the fdt will not be copied at all on boot. For this
5234 to work it must reside in writable memory, have
5235 sufficient padding on the end of it for u-boot to
5236 add the information it needs into it, and the memory
5237 must be accessible by the kernel.
5239 fdtcontroladdr- if set this is the address of the control flattened
5240 device tree used by U-Boot when CONFIG_OF_CONTROL is
5243 i2cfast - (PPC405GP|PPC405EP only)
5244 if set to 'y' configures Linux I2C driver for fast
5245 mode (400kHZ). This environment variable is used in
5246 initialization code. So, for changes to be effective
5247 it must be saved and board must be reset.
5249 initrd_high - restrict positioning of initrd images:
5250 If this variable is not set, initrd images will be
5251 copied to the highest possible address in RAM; this
5252 is usually what you want since it allows for
5253 maximum initrd size. If for some reason you want to
5254 make sure that the initrd image is loaded below the
5255 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5256 variable to a value of "no" or "off" or "0".
5257 Alternatively, you can set it to a maximum upper
5258 address to use (U-Boot will still check that it
5259 does not overwrite the U-Boot stack and data).
5261 For instance, when you have a system with 16 MB
5262 RAM, and want to reserve 4 MB from use by Linux,
5263 you can do this by adding "mem=12M" to the value of
5264 the "bootargs" variable. However, now you must make
5265 sure that the initrd image is placed in the first
5266 12 MB as well - this can be done with
5268 setenv initrd_high 00c00000
5270 If you set initrd_high to 0xFFFFFFFF, this is an
5271 indication to U-Boot that all addresses are legal
5272 for the Linux kernel, including addresses in flash
5273 memory. In this case U-Boot will NOT COPY the
5274 ramdisk at all. This may be useful to reduce the
5275 boot time on your system, but requires that this
5276 feature is supported by your Linux kernel.
5278 ipaddr - IP address; needed for tftpboot command
5280 loadaddr - Default load address for commands like "bootp",
5281 "rarpboot", "tftpboot", "loadb" or "diskboot"
5283 loads_echo - see CONFIG_LOADS_ECHO
5285 serverip - TFTP server IP address; needed for tftpboot command
5287 bootretry - see CONFIG_BOOT_RETRY_TIME
5289 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5291 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5293 ethprime - controls which interface is used first.
5295 ethact - controls which interface is currently active.
5296 For example you can do the following
5298 => setenv ethact FEC
5299 => ping 192.168.0.1 # traffic sent on FEC
5300 => setenv ethact SCC
5301 => ping 10.0.0.1 # traffic sent on SCC
5303 ethrotate - When set to "no" U-Boot does not go through all
5304 available network interfaces.
5305 It just stays at the currently selected interface.
5307 netretry - When set to "no" each network operation will
5308 either succeed or fail without retrying.
5309 When set to "once" the network operation will
5310 fail when all the available network interfaces
5311 are tried once without success.
5312 Useful on scripts which control the retry operation
5315 npe_ucode - set load address for the NPE microcode
5317 silent_linux - If set then Linux will be told to boot silently, by
5318 changing the console to be empty. If "yes" it will be
5319 made silent. If "no" it will not be made silent. If
5320 unset, then it will be made silent if the U-Boot console
5323 tftpsrcp - If this is set, the value is used for TFTP's
5326 tftpdstp - If this is set, the value is used for TFTP's UDP
5327 destination port instead of the Well Know Port 69.
5329 tftpblocksize - Block size to use for TFTP transfers; if not set,
5330 we use the TFTP server's default block size
5332 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5333 seconds, minimum value is 1000 = 1 second). Defines
5334 when a packet is considered to be lost so it has to
5335 be retransmitted. The default is 5000 = 5 seconds.
5336 Lowering this value may make downloads succeed
5337 faster in networks with high packet loss rates or
5338 with unreliable TFTP servers.
5340 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5341 unit, minimum value = 0). Defines how many timeouts
5342 can happen during a single file transfer before that
5343 transfer is aborted. The default is 10, and 0 means
5344 'no timeouts allowed'. Increasing this value may help
5345 downloads succeed with high packet loss rates, or with
5346 unreliable TFTP servers or client hardware.
5348 vlan - When set to a value < 4095 the traffic over
5349 Ethernet is encapsulated/received over 802.1q
5352 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5353 Unsigned value, in milliseconds. If not set, the period will
5354 be either the default (28000), or a value based on
5355 CONFIG_NET_RETRY_COUNT, if defined. This value has
5356 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5358 The following image location variables contain the location of images
5359 used in booting. The "Image" column gives the role of the image and is
5360 not an environment variable name. The other columns are environment
5361 variable names. "File Name" gives the name of the file on a TFTP
5362 server, "RAM Address" gives the location in RAM the image will be
5363 loaded to, and "Flash Location" gives the image's address in NOR
5364 flash or offset in NAND flash.
5366 *Note* - these variables don't have to be defined for all boards, some
5367 boards currently use other variables for these purposes, and some
5368 boards use these variables for other purposes.
5370 Image File Name RAM Address Flash Location
5371 ----- --------- ----------- --------------
5372 u-boot u-boot u-boot_addr_r u-boot_addr
5373 Linux kernel bootfile kernel_addr_r kernel_addr
5374 device tree blob fdtfile fdt_addr_r fdt_addr
5375 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5377 The following environment variables may be used and automatically
5378 updated by the network boot commands ("bootp" and "rarpboot"),
5379 depending the information provided by your boot server:
5381 bootfile - see above
5382 dnsip - IP address of your Domain Name Server
5383 dnsip2 - IP address of your secondary Domain Name Server
5384 gatewayip - IP address of the Gateway (Router) to use
5385 hostname - Target hostname
5387 netmask - Subnet Mask
5388 rootpath - Pathname of the root filesystem on the NFS server
5389 serverip - see above
5392 There are two special Environment Variables:
5394 serial# - contains hardware identification information such
5395 as type string and/or serial number
5396 ethaddr - Ethernet address
5398 These variables can be set only once (usually during manufacturing of
5399 the board). U-Boot refuses to delete or overwrite these variables
5400 once they have been set once.
5403 Further special Environment Variables:
5405 ver - Contains the U-Boot version string as printed
5406 with the "version" command. This variable is
5407 readonly (see CONFIG_VERSION_VARIABLE).
5410 Please note that changes to some configuration parameters may take
5411 only effect after the next boot (yes, that's just like Windoze :-).
5414 Callback functions for environment variables:
5415 ---------------------------------------------
5417 For some environment variables, the behavior of u-boot needs to change
5418 when their values are changed. This functionality allows functions to
5419 be associated with arbitrary variables. On creation, overwrite, or
5420 deletion, the callback will provide the opportunity for some side
5421 effect to happen or for the change to be rejected.
5423 The callbacks are named and associated with a function using the
5424 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5426 These callbacks are associated with variables in one of two ways. The
5427 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5428 in the board configuration to a string that defines a list of
5429 associations. The list must be in the following format:
5431 entry = variable_name[:callback_name]
5434 If the callback name is not specified, then the callback is deleted.
5435 Spaces are also allowed anywhere in the list.
5437 Callbacks can also be associated by defining the ".callbacks" variable
5438 with the same list format above. Any association in ".callbacks" will
5439 override any association in the static list. You can define
5440 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5441 ".callbacks" environment variable in the default or embedded environment.
5443 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5444 regular expression. This allows multiple variables to be connected to
5445 the same callback without explicitly listing them all out.
5448 Command Line Parsing:
5449 =====================
5451 There are two different command line parsers available with U-Boot:
5452 the old "simple" one, and the much more powerful "hush" shell:
5454 Old, simple command line parser:
5455 --------------------------------
5457 - supports environment variables (through setenv / saveenv commands)
5458 - several commands on one line, separated by ';'
5459 - variable substitution using "... ${name} ..." syntax
5460 - special characters ('$', ';') can be escaped by prefixing with '\',
5462 setenv bootcmd bootm \${address}
5463 - You can also escape text by enclosing in single apostrophes, for example:
5464 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5469 - similar to Bourne shell, with control structures like
5470 if...then...else...fi, for...do...done; while...do...done,
5471 until...do...done, ...
5472 - supports environment ("global") variables (through setenv / saveenv
5473 commands) and local shell variables (through standard shell syntax
5474 "name=value"); only environment variables can be used with "run"
5480 (1) If a command line (or an environment variable executed by a "run"
5481 command) contains several commands separated by semicolon, and
5482 one of these commands fails, then the remaining commands will be
5485 (2) If you execute several variables with one call to run (i. e.
5486 calling run with a list of variables as arguments), any failing
5487 command will cause "run" to terminate, i. e. the remaining
5488 variables are not executed.
5490 Note for Redundant Ethernet Interfaces:
5491 =======================================
5493 Some boards come with redundant Ethernet interfaces; U-Boot supports
5494 such configurations and is capable of automatic selection of a
5495 "working" interface when needed. MAC assignment works as follows:
5497 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5498 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5499 "eth1addr" (=>eth1), "eth2addr", ...
5501 If the network interface stores some valid MAC address (for instance
5502 in SROM), this is used as default address if there is NO correspon-
5503 ding setting in the environment; if the corresponding environment
5504 variable is set, this overrides the settings in the card; that means:
5506 o If the SROM has a valid MAC address, and there is no address in the
5507 environment, the SROM's address is used.
5509 o If there is no valid address in the SROM, and a definition in the
5510 environment exists, then the value from the environment variable is
5513 o If both the SROM and the environment contain a MAC address, and
5514 both addresses are the same, this MAC address is used.
5516 o If both the SROM and the environment contain a MAC address, and the
5517 addresses differ, the value from the environment is used and a
5520 o If neither SROM nor the environment contain a MAC address, an error
5521 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5522 a random, locally-assigned MAC is used.
5524 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5525 will be programmed into hardware as part of the initialization process. This
5526 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5527 The naming convention is as follows:
5528 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5533 U-Boot is capable of booting (and performing other auxiliary operations on)
5534 images in two formats:
5536 New uImage format (FIT)
5537 -----------------------
5539 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5540 to Flattened Device Tree). It allows the use of images with multiple
5541 components (several kernels, ramdisks, etc.), with contents protected by
5542 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5548 Old image format is based on binary files which can be basically anything,
5549 preceded by a special header; see the definitions in include/image.h for
5550 details; basically, the header defines the following image properties:
5552 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5553 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5554 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5555 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5557 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5558 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5559 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5560 * Compression Type (uncompressed, gzip, bzip2)
5566 The header is marked by a special Magic Number, and both the header
5567 and the data portions of the image are secured against corruption by
5574 Although U-Boot should support any OS or standalone application
5575 easily, the main focus has always been on Linux during the design of
5578 U-Boot includes many features that so far have been part of some
5579 special "boot loader" code within the Linux kernel. Also, any
5580 "initrd" images to be used are no longer part of one big Linux image;
5581 instead, kernel and "initrd" are separate images. This implementation
5582 serves several purposes:
5584 - the same features can be used for other OS or standalone
5585 applications (for instance: using compressed images to reduce the
5586 Flash memory footprint)
5588 - it becomes much easier to port new Linux kernel versions because
5589 lots of low-level, hardware dependent stuff are done by U-Boot
5591 - the same Linux kernel image can now be used with different "initrd"
5592 images; of course this also means that different kernel images can
5593 be run with the same "initrd". This makes testing easier (you don't
5594 have to build a new "zImage.initrd" Linux image when you just
5595 change a file in your "initrd"). Also, a field-upgrade of the
5596 software is easier now.
5602 Porting Linux to U-Boot based systems:
5603 ---------------------------------------
5605 U-Boot cannot save you from doing all the necessary modifications to
5606 configure the Linux device drivers for use with your target hardware
5607 (no, we don't intend to provide a full virtual machine interface to
5610 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5612 Just make sure your machine specific header file (for instance
5613 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5614 Information structure as we define in include/asm-<arch>/u-boot.h,
5615 and make sure that your definition of IMAP_ADDR uses the same value
5616 as your U-Boot configuration in CONFIG_SYS_IMMR.
5618 Note that U-Boot now has a driver model, a unified model for drivers.
5619 If you are adding a new driver, plumb it into driver model. If there
5620 is no uclass available, you are encouraged to create one. See
5624 Configuring the Linux kernel:
5625 -----------------------------
5627 No specific requirements for U-Boot. Make sure you have some root
5628 device (initial ramdisk, NFS) for your target system.
5631 Building a Linux Image:
5632 -----------------------
5634 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5635 not used. If you use recent kernel source, a new build target
5636 "uImage" will exist which automatically builds an image usable by
5637 U-Boot. Most older kernels also have support for a "pImage" target,
5638 which was introduced for our predecessor project PPCBoot and uses a
5639 100% compatible format.
5643 make TQM850L_defconfig
5648 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5649 encapsulate a compressed Linux kernel image with header information,
5650 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5652 * build a standard "vmlinux" kernel image (in ELF binary format):
5654 * convert the kernel into a raw binary image:
5656 ${CROSS_COMPILE}-objcopy -O binary \
5657 -R .note -R .comment \
5658 -S vmlinux linux.bin
5660 * compress the binary image:
5664 * package compressed binary image for U-Boot:
5666 mkimage -A ppc -O linux -T kernel -C gzip \
5667 -a 0 -e 0 -n "Linux Kernel Image" \
5668 -d linux.bin.gz uImage
5671 The "mkimage" tool can also be used to create ramdisk images for use
5672 with U-Boot, either separated from the Linux kernel image, or
5673 combined into one file. "mkimage" encapsulates the images with a 64
5674 byte header containing information about target architecture,
5675 operating system, image type, compression method, entry points, time
5676 stamp, CRC32 checksums, etc.
5678 "mkimage" can be called in two ways: to verify existing images and
5679 print the header information, or to build new images.
5681 In the first form (with "-l" option) mkimage lists the information
5682 contained in the header of an existing U-Boot image; this includes
5683 checksum verification:
5685 tools/mkimage -l image
5686 -l ==> list image header information
5688 The second form (with "-d" option) is used to build a U-Boot image
5689 from a "data file" which is used as image payload:
5691 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5692 -n name -d data_file image
5693 -A ==> set architecture to 'arch'
5694 -O ==> set operating system to 'os'
5695 -T ==> set image type to 'type'
5696 -C ==> set compression type 'comp'
5697 -a ==> set load address to 'addr' (hex)
5698 -e ==> set entry point to 'ep' (hex)
5699 -n ==> set image name to 'name'
5700 -d ==> use image data from 'datafile'
5702 Right now, all Linux kernels for PowerPC systems use the same load
5703 address (0x00000000), but the entry point address depends on the
5706 - 2.2.x kernels have the entry point at 0x0000000C,
5707 - 2.3.x and later kernels have the entry point at 0x00000000.
5709 So a typical call to build a U-Boot image would read:
5711 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5712 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5713 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5714 > examples/uImage.TQM850L
5715 Image Name: 2.4.4 kernel for TQM850L
5716 Created: Wed Jul 19 02:34:59 2000
5717 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5718 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5719 Load Address: 0x00000000
5720 Entry Point: 0x00000000
5722 To verify the contents of the image (or check for corruption):
5724 -> tools/mkimage -l examples/uImage.TQM850L
5725 Image Name: 2.4.4 kernel for TQM850L
5726 Created: Wed Jul 19 02:34:59 2000
5727 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5728 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5729 Load Address: 0x00000000
5730 Entry Point: 0x00000000
5732 NOTE: for embedded systems where boot time is critical you can trade
5733 speed for memory and install an UNCOMPRESSED image instead: this
5734 needs more space in Flash, but boots much faster since it does not
5735 need to be uncompressed:
5737 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5738 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5739 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5740 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5741 > examples/uImage.TQM850L-uncompressed
5742 Image Name: 2.4.4 kernel for TQM850L
5743 Created: Wed Jul 19 02:34:59 2000
5744 Image Type: PowerPC Linux Kernel Image (uncompressed)
5745 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5746 Load Address: 0x00000000
5747 Entry Point: 0x00000000
5750 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5751 when your kernel is intended to use an initial ramdisk:
5753 -> tools/mkimage -n 'Simple Ramdisk Image' \
5754 > -A ppc -O linux -T ramdisk -C gzip \
5755 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5756 Image Name: Simple Ramdisk Image
5757 Created: Wed Jan 12 14:01:50 2000
5758 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5759 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5760 Load Address: 0x00000000
5761 Entry Point: 0x00000000
5763 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5764 option performs the converse operation of the mkimage's second form (the "-d"
5765 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5768 tools/dumpimage -i image -T type -p position data_file
5769 -i ==> extract from the 'image' a specific 'data_file'
5770 -T ==> set image type to 'type'
5771 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5774 Installing a Linux Image:
5775 -------------------------
5777 To downloading a U-Boot image over the serial (console) interface,
5778 you must convert the image to S-Record format:
5780 objcopy -I binary -O srec examples/image examples/image.srec
5782 The 'objcopy' does not understand the information in the U-Boot
5783 image header, so the resulting S-Record file will be relative to
5784 address 0x00000000. To load it to a given address, you need to
5785 specify the target address as 'offset' parameter with the 'loads'
5788 Example: install the image to address 0x40100000 (which on the
5789 TQM8xxL is in the first Flash bank):
5791 => erase 40100000 401FFFFF
5797 ## Ready for S-Record download ...
5798 ~>examples/image.srec
5799 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5801 15989 15990 15991 15992
5802 [file transfer complete]
5804 ## Start Addr = 0x00000000
5807 You can check the success of the download using the 'iminfo' command;
5808 this includes a checksum verification so you can be sure no data
5809 corruption happened:
5813 ## Checking Image at 40100000 ...
5814 Image Name: 2.2.13 for initrd on TQM850L
5815 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5816 Data Size: 335725 Bytes = 327 kB = 0 MB
5817 Load Address: 00000000
5818 Entry Point: 0000000c
5819 Verifying Checksum ... OK
5825 The "bootm" command is used to boot an application that is stored in
5826 memory (RAM or Flash). In case of a Linux kernel image, the contents
5827 of the "bootargs" environment variable is passed to the kernel as
5828 parameters. You can check and modify this variable using the
5829 "printenv" and "setenv" commands:
5832 => printenv bootargs
5833 bootargs=root=/dev/ram
5835 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5837 => printenv bootargs
5838 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5841 ## Booting Linux kernel at 40020000 ...
5842 Image Name: 2.2.13 for NFS on TQM850L
5843 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5844 Data Size: 381681 Bytes = 372 kB = 0 MB
5845 Load Address: 00000000
5846 Entry Point: 0000000c
5847 Verifying Checksum ... OK
5848 Uncompressing Kernel Image ... OK
5849 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
5850 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5851 time_init: decrementer frequency = 187500000/60
5852 Calibrating delay loop... 49.77 BogoMIPS
5853 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5856 If you want to boot a Linux kernel with initial RAM disk, you pass
5857 the memory addresses of both the kernel and the initrd image (PPBCOOT
5858 format!) to the "bootm" command:
5860 => imi 40100000 40200000
5862 ## Checking Image at 40100000 ...
5863 Image Name: 2.2.13 for initrd on TQM850L
5864 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5865 Data Size: 335725 Bytes = 327 kB = 0 MB
5866 Load Address: 00000000
5867 Entry Point: 0000000c
5868 Verifying Checksum ... OK
5870 ## Checking Image at 40200000 ...
5871 Image Name: Simple Ramdisk Image
5872 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5873 Data Size: 566530 Bytes = 553 kB = 0 MB
5874 Load Address: 00000000
5875 Entry Point: 00000000
5876 Verifying Checksum ... OK
5878 => bootm 40100000 40200000
5879 ## Booting Linux kernel at 40100000 ...
5880 Image Name: 2.2.13 for initrd on TQM850L
5881 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5882 Data Size: 335725 Bytes = 327 kB = 0 MB
5883 Load Address: 00000000
5884 Entry Point: 0000000c
5885 Verifying Checksum ... OK
5886 Uncompressing Kernel Image ... OK
5887 ## Loading RAMDisk Image at 40200000 ...
5888 Image Name: Simple Ramdisk Image
5889 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5890 Data Size: 566530 Bytes = 553 kB = 0 MB
5891 Load Address: 00000000
5892 Entry Point: 00000000
5893 Verifying Checksum ... OK
5894 Loading Ramdisk ... OK
5895 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
5896 Boot arguments: root=/dev/ram
5897 time_init: decrementer frequency = 187500000/60
5898 Calibrating delay loop... 49.77 BogoMIPS
5900 RAMDISK: Compressed image found at block 0
5901 VFS: Mounted root (ext2 filesystem).
5905 Boot Linux and pass a flat device tree:
5908 First, U-Boot must be compiled with the appropriate defines. See the section
5909 titled "Linux Kernel Interface" above for a more in depth explanation. The
5910 following is an example of how to start a kernel and pass an updated
5916 oft=oftrees/mpc8540ads.dtb
5917 => tftp $oftaddr $oft
5918 Speed: 1000, full duplex
5920 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5921 Filename 'oftrees/mpc8540ads.dtb'.
5922 Load address: 0x300000
5925 Bytes transferred = 4106 (100a hex)
5926 => tftp $loadaddr $bootfile
5927 Speed: 1000, full duplex
5929 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5931 Load address: 0x200000
5932 Loading:############
5934 Bytes transferred = 1029407 (fb51f hex)
5939 => bootm $loadaddr - $oftaddr
5940 ## Booting image at 00200000 ...
5941 Image Name: Linux-2.6.17-dirty
5942 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5943 Data Size: 1029343 Bytes = 1005.2 kB
5944 Load Address: 00000000
5945 Entry Point: 00000000
5946 Verifying Checksum ... OK
5947 Uncompressing Kernel Image ... OK
5948 Booting using flat device tree at 0x300000
5949 Using MPC85xx ADS machine description
5950 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5954 More About U-Boot Image Types:
5955 ------------------------------
5957 U-Boot supports the following image types:
5959 "Standalone Programs" are directly runnable in the environment
5960 provided by U-Boot; it is expected that (if they behave
5961 well) you can continue to work in U-Boot after return from
5962 the Standalone Program.
5963 "OS Kernel Images" are usually images of some Embedded OS which
5964 will take over control completely. Usually these programs
5965 will install their own set of exception handlers, device
5966 drivers, set up the MMU, etc. - this means, that you cannot
5967 expect to re-enter U-Boot except by resetting the CPU.
5968 "RAMDisk Images" are more or less just data blocks, and their
5969 parameters (address, size) are passed to an OS kernel that is
5971 "Multi-File Images" contain several images, typically an OS
5972 (Linux) kernel image and one or more data images like
5973 RAMDisks. This construct is useful for instance when you want
5974 to boot over the network using BOOTP etc., where the boot
5975 server provides just a single image file, but you want to get
5976 for instance an OS kernel and a RAMDisk image.
5978 "Multi-File Images" start with a list of image sizes, each
5979 image size (in bytes) specified by an "uint32_t" in network
5980 byte order. This list is terminated by an "(uint32_t)0".
5981 Immediately after the terminating 0 follow the images, one by
5982 one, all aligned on "uint32_t" boundaries (size rounded up to
5983 a multiple of 4 bytes).
5985 "Firmware Images" are binary images containing firmware (like
5986 U-Boot or FPGA images) which usually will be programmed to
5989 "Script files" are command sequences that will be executed by
5990 U-Boot's command interpreter; this feature is especially
5991 useful when you configure U-Boot to use a real shell (hush)
5992 as command interpreter.
5994 Booting the Linux zImage:
5995 -------------------------
5997 On some platforms, it's possible to boot Linux zImage. This is done
5998 using the "bootz" command. The syntax of "bootz" command is the same
5999 as the syntax of "bootm" command.
6001 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6002 kernel with raw initrd images. The syntax is slightly different, the
6003 address of the initrd must be augmented by it's size, in the following
6004 format: "<initrd addres>:<initrd size>".
6010 One of the features of U-Boot is that you can dynamically load and
6011 run "standalone" applications, which can use some resources of
6012 U-Boot like console I/O functions or interrupt services.
6014 Two simple examples are included with the sources:
6019 'examples/hello_world.c' contains a small "Hello World" Demo
6020 application; it is automatically compiled when you build U-Boot.
6021 It's configured to run at address 0x00040004, so you can play with it
6025 ## Ready for S-Record download ...
6026 ~>examples/hello_world.srec
6027 1 2 3 4 5 6 7 8 9 10 11 ...
6028 [file transfer complete]
6030 ## Start Addr = 0x00040004
6032 => go 40004 Hello World! This is a test.
6033 ## Starting application at 0x00040004 ...
6044 Hit any key to exit ...
6046 ## Application terminated, rc = 0x0
6048 Another example, which demonstrates how to register a CPM interrupt
6049 handler with the U-Boot code, can be found in 'examples/timer.c'.
6050 Here, a CPM timer is set up to generate an interrupt every second.
6051 The interrupt service routine is trivial, just printing a '.'
6052 character, but this is just a demo program. The application can be
6053 controlled by the following keys:
6055 ? - print current values og the CPM Timer registers
6056 b - enable interrupts and start timer
6057 e - stop timer and disable interrupts
6058 q - quit application
6061 ## Ready for S-Record download ...
6062 ~>examples/timer.srec
6063 1 2 3 4 5 6 7 8 9 10 11 ...
6064 [file transfer complete]
6066 ## Start Addr = 0x00040004
6069 ## Starting application at 0x00040004 ...
6072 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6075 [q, b, e, ?] Set interval 1000000 us
6078 [q, b, e, ?] ........
6079 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6082 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6085 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6088 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6090 [q, b, e, ?] ...Stopping timer
6092 [q, b, e, ?] ## Application terminated, rc = 0x0
6098 Over time, many people have reported problems when trying to use the
6099 "minicom" terminal emulation program for serial download. I (wd)
6100 consider minicom to be broken, and recommend not to use it. Under
6101 Unix, I recommend to use C-Kermit for general purpose use (and
6102 especially for kermit binary protocol download ("loadb" command), and
6103 use "cu" for S-Record download ("loads" command). See
6104 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6105 for help with kermit.
6108 Nevertheless, if you absolutely want to use it try adding this
6109 configuration to your "File transfer protocols" section:
6111 Name Program Name U/D FullScr IO-Red. Multi
6112 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6113 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6119 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6120 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6122 Building requires a cross environment; it is known to work on
6123 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6124 need gmake since the Makefiles are not compatible with BSD make).
6125 Note that the cross-powerpc package does not install include files;
6126 attempting to build U-Boot will fail because <machine/ansi.h> is
6127 missing. This file has to be installed and patched manually:
6129 # cd /usr/pkg/cross/powerpc-netbsd/include
6131 # ln -s powerpc machine
6132 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6133 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6135 Native builds *don't* work due to incompatibilities between native
6136 and U-Boot include files.
6138 Booting assumes that (the first part of) the image booted is a
6139 stage-2 loader which in turn loads and then invokes the kernel
6140 proper. Loader sources will eventually appear in the NetBSD source
6141 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6142 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6145 Implementation Internals:
6146 =========================
6148 The following is not intended to be a complete description of every
6149 implementation detail. However, it should help to understand the
6150 inner workings of U-Boot and make it easier to port it to custom
6154 Initial Stack, Global Data:
6155 ---------------------------
6157 The implementation of U-Boot is complicated by the fact that U-Boot
6158 starts running out of ROM (flash memory), usually without access to
6159 system RAM (because the memory controller is not initialized yet).
6160 This means that we don't have writable Data or BSS segments, and BSS
6161 is not initialized as zero. To be able to get a C environment working
6162 at all, we have to allocate at least a minimal stack. Implementation
6163 options for this are defined and restricted by the CPU used: Some CPU
6164 models provide on-chip memory (like the IMMR area on MPC8xx and
6165 MPC826x processors), on others (parts of) the data cache can be
6166 locked as (mis-) used as memory, etc.
6168 Chris Hallinan posted a good summary of these issues to the
6169 U-Boot mailing list:
6171 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6172 From: "Chris Hallinan" <clh@net1plus.com>
6173 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6176 Correct me if I'm wrong, folks, but the way I understand it
6177 is this: Using DCACHE as initial RAM for Stack, etc, does not
6178 require any physical RAM backing up the cache. The cleverness
6179 is that the cache is being used as a temporary supply of
6180 necessary storage before the SDRAM controller is setup. It's
6181 beyond the scope of this list to explain the details, but you
6182 can see how this works by studying the cache architecture and
6183 operation in the architecture and processor-specific manuals.
6185 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6186 is another option for the system designer to use as an
6187 initial stack/RAM area prior to SDRAM being available. Either
6188 option should work for you. Using CS 4 should be fine if your
6189 board designers haven't used it for something that would
6190 cause you grief during the initial boot! It is frequently not
6193 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6194 with your processor/board/system design. The default value
6195 you will find in any recent u-boot distribution in
6196 walnut.h should work for you. I'd set it to a value larger
6197 than your SDRAM module. If you have a 64MB SDRAM module, set
6198 it above 400_0000. Just make sure your board has no resources
6199 that are supposed to respond to that address! That code in
6200 start.S has been around a while and should work as is when
6201 you get the config right.
6206 It is essential to remember this, since it has some impact on the C
6207 code for the initialization procedures:
6209 * Initialized global data (data segment) is read-only. Do not attempt
6212 * Do not use any uninitialized global data (or implicitly initialized
6213 as zero data - BSS segment) at all - this is undefined, initiali-
6214 zation is performed later (when relocating to RAM).
6216 * Stack space is very limited. Avoid big data buffers or things like
6219 Having only the stack as writable memory limits means we cannot use
6220 normal global data to share information between the code. But it
6221 turned out that the implementation of U-Boot can be greatly
6222 simplified by making a global data structure (gd_t) available to all
6223 functions. We could pass a pointer to this data as argument to _all_
6224 functions, but this would bloat the code. Instead we use a feature of
6225 the GCC compiler (Global Register Variables) to share the data: we
6226 place a pointer (gd) to the global data into a register which we
6227 reserve for this purpose.
6229 When choosing a register for such a purpose we are restricted by the
6230 relevant (E)ABI specifications for the current architecture, and by
6231 GCC's implementation.
6233 For PowerPC, the following registers have specific use:
6235 R2: reserved for system use
6236 R3-R4: parameter passing and return values
6237 R5-R10: parameter passing
6238 R13: small data area pointer
6242 (U-Boot also uses R12 as internal GOT pointer. r12
6243 is a volatile register so r12 needs to be reset when
6244 going back and forth between asm and C)
6246 ==> U-Boot will use R2 to hold a pointer to the global data
6248 Note: on PPC, we could use a static initializer (since the
6249 address of the global data structure is known at compile time),
6250 but it turned out that reserving a register results in somewhat
6251 smaller code - although the code savings are not that big (on
6252 average for all boards 752 bytes for the whole U-Boot image,
6253 624 text + 127 data).
6255 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6256 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6258 ==> U-Boot will use P3 to hold a pointer to the global data
6260 On ARM, the following registers are used:
6262 R0: function argument word/integer result
6263 R1-R3: function argument word
6264 R9: platform specific
6265 R10: stack limit (used only if stack checking is enabled)
6266 R11: argument (frame) pointer
6267 R12: temporary workspace
6270 R15: program counter
6272 ==> U-Boot will use R9 to hold a pointer to the global data
6274 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6276 On Nios II, the ABI is documented here:
6277 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6279 ==> U-Boot will use gp to hold a pointer to the global data
6281 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6282 to access small data sections, so gp is free.
6284 On NDS32, the following registers are used:
6286 R0-R1: argument/return
6288 R15: temporary register for assembler
6289 R16: trampoline register
6290 R28: frame pointer (FP)
6291 R29: global pointer (GP)
6292 R30: link register (LP)
6293 R31: stack pointer (SP)
6294 PC: program counter (PC)
6296 ==> U-Boot will use R10 to hold a pointer to the global data
6298 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6299 or current versions of GCC may "optimize" the code too much.
6304 U-Boot runs in system state and uses physical addresses, i.e. the
6305 MMU is not used either for address mapping nor for memory protection.
6307 The available memory is mapped to fixed addresses using the memory
6308 controller. In this process, a contiguous block is formed for each
6309 memory type (Flash, SDRAM, SRAM), even when it consists of several
6310 physical memory banks.
6312 U-Boot is installed in the first 128 kB of the first Flash bank (on
6313 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6314 booting and sizing and initializing DRAM, the code relocates itself
6315 to the upper end of DRAM. Immediately below the U-Boot code some
6316 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6317 configuration setting]. Below that, a structure with global Board
6318 Info data is placed, followed by the stack (growing downward).
6320 Additionally, some exception handler code is copied to the low 8 kB
6321 of DRAM (0x00000000 ... 0x00001FFF).
6323 So a typical memory configuration with 16 MB of DRAM could look like
6326 0x0000 0000 Exception Vector code
6329 0x0000 2000 Free for Application Use
6335 0x00FB FF20 Monitor Stack (Growing downward)
6336 0x00FB FFAC Board Info Data and permanent copy of global data
6337 0x00FC 0000 Malloc Arena
6340 0x00FE 0000 RAM Copy of Monitor Code
6341 ... eventually: LCD or video framebuffer
6342 ... eventually: pRAM (Protected RAM - unchanged by reset)
6343 0x00FF FFFF [End of RAM]
6346 System Initialization:
6347 ----------------------
6349 In the reset configuration, U-Boot starts at the reset entry point
6350 (on most PowerPC systems at address 0x00000100). Because of the reset
6351 configuration for CS0# this is a mirror of the on board Flash memory.
6352 To be able to re-map memory U-Boot then jumps to its link address.
6353 To be able to implement the initialization code in C, a (small!)
6354 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6355 which provide such a feature like MPC8xx or MPC8260), or in a locked
6356 part of the data cache. After that, U-Boot initializes the CPU core,
6357 the caches and the SIU.
6359 Next, all (potentially) available memory banks are mapped using a
6360 preliminary mapping. For example, we put them on 512 MB boundaries
6361 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6362 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6363 programmed for SDRAM access. Using the temporary configuration, a
6364 simple memory test is run that determines the size of the SDRAM
6367 When there is more than one SDRAM bank, and the banks are of
6368 different size, the largest is mapped first. For equal size, the first
6369 bank (CS2#) is mapped first. The first mapping is always for address
6370 0x00000000, with any additional banks following immediately to create
6371 contiguous memory starting from 0.
6373 Then, the monitor installs itself at the upper end of the SDRAM area
6374 and allocates memory for use by malloc() and for the global Board
6375 Info data; also, the exception vector code is copied to the low RAM
6376 pages, and the final stack is set up.
6378 Only after this relocation will you have a "normal" C environment;
6379 until that you are restricted in several ways, mostly because you are
6380 running from ROM, and because the code will have to be relocated to a
6384 U-Boot Porting Guide:
6385 ----------------------
6387 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6391 int main(int argc, char *argv[])
6393 sighandler_t no_more_time;
6395 signal(SIGALRM, no_more_time);
6396 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6398 if (available_money > available_manpower) {
6399 Pay consultant to port U-Boot;
6403 Download latest U-Boot source;
6405 Subscribe to u-boot mailing list;
6408 email("Hi, I am new to U-Boot, how do I get started?");
6411 Read the README file in the top level directory;
6412 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6413 Read applicable doc/*.README;
6414 Read the source, Luke;
6415 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6418 if (available_money > toLocalCurrency ($2500))
6421 Add a lot of aggravation and time;
6423 if (a similar board exists) { /* hopefully... */
6424 cp -a board/<similar> board/<myboard>
6425 cp include/configs/<similar>.h include/configs/<myboard>.h
6427 Create your own board support subdirectory;
6428 Create your own board include/configs/<myboard>.h file;
6430 Edit new board/<myboard> files
6431 Edit new include/configs/<myboard>.h
6436 Add / modify source code;
6440 email("Hi, I am having problems...");
6442 Send patch file to the U-Boot email list;
6443 if (reasonable critiques)
6444 Incorporate improvements from email list code review;
6446 Defend code as written;
6452 void no_more_time (int sig)
6461 All contributions to U-Boot should conform to the Linux kernel
6462 coding style; see the file "Documentation/CodingStyle" and the script
6463 "scripts/Lindent" in your Linux kernel source directory.
6465 Source files originating from a different project (for example the
6466 MTD subsystem) are generally exempt from these guidelines and are not
6467 reformatted to ease subsequent migration to newer versions of those
6470 Please note that U-Boot is implemented in C (and to some small parts in
6471 Assembler); no C++ is used, so please do not use C++ style comments (//)
6474 Please also stick to the following formatting rules:
6475 - remove any trailing white space
6476 - use TAB characters for indentation and vertical alignment, not spaces
6477 - make sure NOT to use DOS '\r\n' line feeds
6478 - do not add more than 2 consecutive empty lines to source files
6479 - do not add trailing empty lines to source files
6481 Submissions which do not conform to the standards may be returned
6482 with a request to reformat the changes.
6488 Since the number of patches for U-Boot is growing, we need to
6489 establish some rules. Submissions which do not conform to these rules
6490 may be rejected, even when they contain important and valuable stuff.
6492 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6494 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6495 see http://lists.denx.de/mailman/listinfo/u-boot
6497 When you send a patch, please include the following information with
6500 * For bug fixes: a description of the bug and how your patch fixes
6501 this bug. Please try to include a way of demonstrating that the
6502 patch actually fixes something.
6504 * For new features: a description of the feature and your
6507 * A CHANGELOG entry as plaintext (separate from the patch)
6509 * For major contributions, add a MAINTAINERS file with your
6510 information and associated file and directory references.
6512 * When you add support for a new board, don't forget to add a
6513 maintainer e-mail address to the boards.cfg file, too.
6515 * If your patch adds new configuration options, don't forget to
6516 document these in the README file.
6518 * The patch itself. If you are using git (which is *strongly*
6519 recommended) you can easily generate the patch using the
6520 "git format-patch". If you then use "git send-email" to send it to
6521 the U-Boot mailing list, you will avoid most of the common problems
6522 with some other mail clients.
6524 If you cannot use git, use "diff -purN OLD NEW". If your version of
6525 diff does not support these options, then get the latest version of
6528 The current directory when running this command shall be the parent
6529 directory of the U-Boot source tree (i. e. please make sure that
6530 your patch includes sufficient directory information for the
6533 We prefer patches as plain text. MIME attachments are discouraged,
6534 and compressed attachments must not be used.
6536 * If one logical set of modifications affects or creates several
6537 files, all these changes shall be submitted in a SINGLE patch file.
6539 * Changesets that contain different, unrelated modifications shall be
6540 submitted as SEPARATE patches, one patch per changeset.
6545 * Before sending the patch, run the buildman script on your patched
6546 source tree and make sure that no errors or warnings are reported
6547 for any of the boards.
6549 * Keep your modifications to the necessary minimum: A patch
6550 containing several unrelated changes or arbitrary reformats will be
6551 returned with a request to re-formatting / split it.
6553 * If you modify existing code, make sure that your new code does not
6554 add to the memory footprint of the code ;-) Small is beautiful!
6555 When adding new features, these should compile conditionally only
6556 (using #ifdef), and the resulting code with the new feature
6557 disabled must not need more memory than the old code without your
6560 * Remember that there is a size limit of 100 kB per message on the
6561 u-boot mailing list. Bigger patches will be moderated. If they are
6562 reasonable and not too big, they will be acknowledged. But patches
6563 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob