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 eanbeld 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
844 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
845 a limited number of ANSI escape sequences (cursor control,
846 erase functions and limited graphics rendition control).
848 When CONFIG_CFB_CONSOLE is defined, video console is
849 default i/o. Serial console can be forced with
850 environment 'console=serial'.
852 When CONFIG_SILENT_CONSOLE is defined, all console
853 messages (by U-Boot and Linux!) can be silenced with
854 the "silent" environment variable. See
855 doc/README.silent for more information.
857 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
859 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
863 CONFIG_BAUDRATE - in bps
864 Select one of the baudrates listed in
865 CONFIG_SYS_BAUDRATE_TABLE, see below.
866 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
868 - Console Rx buffer length
869 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
870 the maximum receive buffer length for the SMC.
871 This option is actual only for 82xx and 8xx possible.
872 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
873 must be defined, to setup the maximum idle timeout for
876 - Pre-Console Buffer:
877 Prior to the console being initialised (i.e. serial UART
878 initialised etc) all console output is silently discarded.
879 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
880 buffer any console messages prior to the console being
881 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
882 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
883 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
884 bytes are output before the console is initialised, the
885 earlier bytes are discarded.
887 Note that when printing the buffer a copy is made on the
888 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
890 'Sane' compilers will generate smaller code if
891 CONFIG_PRE_CON_BUF_SZ is a power of 2
893 - Boot Delay: CONFIG_BOOTDELAY - in seconds
894 Delay before automatically booting the default image;
895 set to -1 to disable autoboot.
896 set to -2 to autoboot with no delay and not check for abort
897 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
899 See doc/README.autoboot for these options that
900 work with CONFIG_BOOTDELAY. None are required.
901 CONFIG_BOOT_RETRY_TIME
902 CONFIG_BOOT_RETRY_MIN
903 CONFIG_AUTOBOOT_KEYED
904 CONFIG_AUTOBOOT_PROMPT
905 CONFIG_AUTOBOOT_DELAY_STR
906 CONFIG_AUTOBOOT_STOP_STR
907 CONFIG_ZERO_BOOTDELAY_CHECK
908 CONFIG_RESET_TO_RETRY
912 Only needed when CONFIG_BOOTDELAY is enabled;
913 define a command string that is automatically executed
914 when no character is read on the console interface
915 within "Boot Delay" after reset.
918 This can be used to pass arguments to the bootm
919 command. The value of CONFIG_BOOTARGS goes into the
920 environment value "bootargs".
922 CONFIG_RAMBOOT and CONFIG_NFSBOOT
923 The value of these goes into the environment as
924 "ramboot" and "nfsboot" respectively, and can be used
925 as a convenience, when switching between booting from
929 CONFIG_BOOTCOUNT_LIMIT
930 Implements a mechanism for detecting a repeating reboot
932 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
935 If no softreset save registers are found on the hardware
936 "bootcount" is stored in the environment. To prevent a
937 saveenv on all reboots, the environment variable
938 "upgrade_available" is used. If "upgrade_available" is
939 0, "bootcount" is always 0, if "upgrade_available" is
940 1 "bootcount" is incremented in the environment.
941 So the Userspace Applikation must set the "upgrade_available"
942 and "bootcount" variable to 0, if a boot was successfully.
947 When this option is #defined, the existence of the
948 environment variable "preboot" will be checked
949 immediately before starting the CONFIG_BOOTDELAY
950 countdown and/or running the auto-boot command resp.
951 entering interactive mode.
953 This feature is especially useful when "preboot" is
954 automatically generated or modified. For an example
955 see the LWMON board specific code: here "preboot" is
956 modified when the user holds down a certain
957 combination of keys on the (special) keyboard when
960 - Serial Download Echo Mode:
962 If defined to 1, all characters received during a
963 serial download (using the "loads" command) are
964 echoed back. This might be needed by some terminal
965 emulations (like "cu"), but may as well just take
966 time on others. This setting #define's the initial
967 value of the "loads_echo" environment variable.
969 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
971 Select one of the baudrates listed in
972 CONFIG_SYS_BAUDRATE_TABLE, see below.
975 Monitor commands can be included or excluded
976 from the build by using the #include files
977 <config_cmd_all.h> and #undef'ing unwanted
978 commands, or adding #define's for wanted commands.
980 The default command configuration includes all commands
981 except those marked below with a "*".
983 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
984 CONFIG_CMD_ASKENV * ask for env variable
985 CONFIG_CMD_BDI bdinfo
986 CONFIG_CMD_BEDBUG * Include BedBug Debugger
987 CONFIG_CMD_BMP * BMP support
988 CONFIG_CMD_BSP * Board specific commands
989 CONFIG_CMD_BOOTD bootd
990 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
991 CONFIG_CMD_CACHE * icache, dcache
992 CONFIG_CMD_CLK * clock command support
993 CONFIG_CMD_CONSOLE coninfo
994 CONFIG_CMD_CRC32 * crc32
995 CONFIG_CMD_DATE * support for RTC, date/time...
996 CONFIG_CMD_DHCP * DHCP support
997 CONFIG_CMD_DIAG * Diagnostics
998 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
999 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1000 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1001 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1002 CONFIG_CMD_DTT * Digital Therm and Thermostat
1003 CONFIG_CMD_ECHO echo arguments
1004 CONFIG_CMD_EDITENV edit env variable
1005 CONFIG_CMD_EEPROM * EEPROM read/write support
1006 CONFIG_CMD_ELF * bootelf, bootvx
1007 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1008 CONFIG_CMD_ENV_FLAGS * display details about env flags
1009 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1010 CONFIG_CMD_EXPORTENV * export the environment
1011 CONFIG_CMD_EXT2 * ext2 command support
1012 CONFIG_CMD_EXT4 * ext4 command support
1013 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1014 that work for multiple fs types
1015 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1016 CONFIG_CMD_SAVEENV saveenv
1017 CONFIG_CMD_FDC * Floppy Disk Support
1018 CONFIG_CMD_FAT * FAT command support
1019 CONFIG_CMD_FLASH flinfo, erase, protect
1020 CONFIG_CMD_FPGA FPGA device initialization support
1021 CONFIG_CMD_FUSE * Device fuse support
1022 CONFIG_CMD_GETTIME * Get time since boot
1023 CONFIG_CMD_GO * the 'go' command (exec code)
1024 CONFIG_CMD_GREPENV * search environment
1025 CONFIG_CMD_HASH * calculate hash / digest
1026 CONFIG_CMD_I2C * I2C serial bus support
1027 CONFIG_CMD_IDE * IDE harddisk support
1028 CONFIG_CMD_IMI iminfo
1029 CONFIG_CMD_IMLS List all images found in NOR flash
1030 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1031 CONFIG_CMD_IMMAP * IMMR dump support
1032 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1033 CONFIG_CMD_IMPORTENV * import an environment
1034 CONFIG_CMD_INI * import data from an ini file into the env
1035 CONFIG_CMD_IRQ * irqinfo
1036 CONFIG_CMD_ITEST Integer/string test of 2 values
1037 CONFIG_CMD_JFFS2 * JFFS2 Support
1038 CONFIG_CMD_KGDB * kgdb
1039 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1040 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1042 CONFIG_CMD_LOADB loadb
1043 CONFIG_CMD_LOADS loads
1044 CONFIG_CMD_MD5SUM * print md5 message digest
1045 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1046 CONFIG_CMD_MEMINFO * Display detailed memory information
1047 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1049 CONFIG_CMD_MEMTEST * mtest
1050 CONFIG_CMD_MISC Misc functions like sleep etc
1051 CONFIG_CMD_MMC * MMC memory mapped support
1052 CONFIG_CMD_MII * MII utility commands
1053 CONFIG_CMD_MTDPARTS * MTD partition support
1054 CONFIG_CMD_NAND * NAND support
1055 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1056 CONFIG_CMD_NFS NFS support
1057 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1058 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1059 CONFIG_CMD_PCI * pciinfo
1060 CONFIG_CMD_PCMCIA * PCMCIA support
1061 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1063 CONFIG_CMD_PORTIO * Port I/O
1064 CONFIG_CMD_READ * Read raw data from partition
1065 CONFIG_CMD_REGINFO * Register dump
1066 CONFIG_CMD_RUN run command in env variable
1067 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1068 CONFIG_CMD_SAVES * save S record dump
1069 CONFIG_SCSI * SCSI Support
1070 CONFIG_CMD_SDRAM * print SDRAM configuration information
1071 (requires CONFIG_CMD_I2C)
1072 CONFIG_CMD_SETGETDCR Support for DCR Register access
1074 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1075 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1076 (requires CONFIG_CMD_MEMORY)
1077 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1078 CONFIG_CMD_SOURCE "source" command Support
1079 CONFIG_CMD_SPI * SPI serial bus support
1080 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1081 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1082 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1083 CONFIG_CMD_TIMER * access to the system tick timer
1084 CONFIG_CMD_USB * USB support
1085 CONFIG_CMD_CDP * Cisco Discover Protocol support
1086 CONFIG_CMD_MFSL * Microblaze FSL support
1087 CONFIG_CMD_XIMG Load part of Multi Image
1088 CONFIG_CMD_UUID * Generate random UUID or GUID string
1090 EXAMPLE: If you want all functions except of network
1091 support you can write:
1093 #include "config_cmd_all.h"
1094 #undef CONFIG_CMD_NET
1097 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1099 Note: Don't enable the "icache" and "dcache" commands
1100 (configuration option CONFIG_CMD_CACHE) unless you know
1101 what you (and your U-Boot users) are doing. Data
1102 cache cannot be enabled on systems like the 8xx or
1103 8260 (where accesses to the IMMR region must be
1104 uncached), and it cannot be disabled on all other
1105 systems where we (mis-) use the data cache to hold an
1106 initial stack and some data.
1109 XXX - this list needs to get updated!
1111 - Removal of commands
1112 If no commands are needed to boot, you can disable
1113 CONFIG_CMDLINE to remove them. In this case, the command line
1114 will not be available, and when U-Boot wants to execute the
1115 boot command (on start-up) it will call board_run_command()
1116 instead. This can reduce image size significantly for very
1117 simple boot procedures.
1119 - Regular expression support:
1121 If this variable is defined, U-Boot is linked against
1122 the SLRE (Super Light Regular Expression) library,
1123 which adds regex support to some commands, as for
1124 example "env grep" and "setexpr".
1128 If this variable is defined, U-Boot will use a device tree
1129 to configure its devices, instead of relying on statically
1130 compiled #defines in the board file. This option is
1131 experimental and only available on a few boards. The device
1132 tree is available in the global data as gd->fdt_blob.
1134 U-Boot needs to get its device tree from somewhere. This can
1135 be done using one of the two options below:
1138 If this variable is defined, U-Boot will embed a device tree
1139 binary in its image. This device tree file should be in the
1140 board directory and called <soc>-<board>.dts. The binary file
1141 is then picked up in board_init_f() and made available through
1142 the global data structure as gd->blob.
1145 If this variable is defined, U-Boot will build a device tree
1146 binary. It will be called u-boot.dtb. Architecture-specific
1147 code will locate it at run-time. Generally this works by:
1149 cat u-boot.bin u-boot.dtb >image.bin
1151 and in fact, U-Boot does this for you, creating a file called
1152 u-boot-dtb.bin which is useful in the common case. You can
1153 still use the individual files if you need something more
1158 If this variable is defined, it enables watchdog
1159 support for the SoC. There must be support in the SoC
1160 specific code for a watchdog. For the 8xx and 8260
1161 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1162 register. When supported for a specific SoC is
1163 available, then no further board specific code should
1164 be needed to use it.
1167 When using a watchdog circuitry external to the used
1168 SoC, then define this variable and provide board
1169 specific code for the "hw_watchdog_reset" function.
1171 CONFIG_AT91_HW_WDT_TIMEOUT
1172 specify the timeout in seconds. default 2 seconds.
1175 CONFIG_VERSION_VARIABLE
1176 If this variable is defined, an environment variable
1177 named "ver" is created by U-Boot showing the U-Boot
1178 version as printed by the "version" command.
1179 Any change to this variable will be reverted at the
1184 When CONFIG_CMD_DATE is selected, the type of the RTC
1185 has to be selected, too. Define exactly one of the
1188 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1189 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1190 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1191 CONFIG_RTC_MC146818 - use MC146818 RTC
1192 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1193 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1194 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1195 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1196 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1197 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1198 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1199 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1200 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1203 Note that if the RTC uses I2C, then the I2C interface
1204 must also be configured. See I2C Support, below.
1207 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1209 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1210 chip-ngpio pairs that tell the PCA953X driver the number of
1211 pins supported by a particular chip.
1213 Note that if the GPIO device uses I2C, then the I2C interface
1214 must also be configured. See I2C Support, below.
1217 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1218 accesses and can checksum them or write a list of them out
1219 to memory. See the 'iotrace' command for details. This is
1220 useful for testing device drivers since it can confirm that
1221 the driver behaves the same way before and after a code
1222 change. Currently this is supported on sandbox and arm. To
1223 add support for your architecture, add '#include <iotrace.h>'
1224 to the bottom of arch/<arch>/include/asm/io.h and test.
1226 Example output from the 'iotrace stats' command is below.
1227 Note that if the trace buffer is exhausted, the checksum will
1228 still continue to operate.
1231 Start: 10000000 (buffer start address)
1232 Size: 00010000 (buffer size)
1233 Offset: 00000120 (current buffer offset)
1234 Output: 10000120 (start + offset)
1235 Count: 00000018 (number of trace records)
1236 CRC32: 9526fb66 (CRC32 of all trace records)
1238 - Timestamp Support:
1240 When CONFIG_TIMESTAMP is selected, the timestamp
1241 (date and time) of an image is printed by image
1242 commands like bootm or iminfo. This option is
1243 automatically enabled when you select CONFIG_CMD_DATE .
1245 - Partition Labels (disklabels) Supported:
1246 Zero or more of the following:
1247 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1248 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1249 Intel architecture, USB sticks, etc.
1250 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1251 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1252 bootloader. Note 2TB partition limit; see
1254 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1256 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1257 CONFIG_SCSI) you must configure support for at
1258 least one non-MTD partition type as well.
1261 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1262 board configurations files but used nowhere!
1264 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1265 be performed by calling the function
1266 ide_set_reset(int reset)
1267 which has to be defined in a board specific file
1272 Set this to enable ATAPI support.
1277 Set this to enable support for disks larger than 137GB
1278 Also look at CONFIG_SYS_64BIT_LBA.
1279 Whithout these , LBA48 support uses 32bit variables and will 'only'
1280 support disks up to 2.1TB.
1282 CONFIG_SYS_64BIT_LBA:
1283 When enabled, makes the IDE subsystem use 64bit sector addresses.
1287 At the moment only there is only support for the
1288 SYM53C8XX SCSI controller; define
1289 CONFIG_SCSI_SYM53C8XX to enable it.
1291 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1292 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1293 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1294 maximum numbers of LUNs, SCSI ID's and target
1296 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1298 The environment variable 'scsidevs' is set to the number of
1299 SCSI devices found during the last scan.
1301 - NETWORK Support (PCI):
1303 Support for Intel 8254x/8257x gigabit chips.
1306 Utility code for direct access to the SPI bus on Intel 8257x.
1307 This does not do anything useful unless you set at least one
1308 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1310 CONFIG_E1000_SPI_GENERIC
1311 Allow generic access to the SPI bus on the Intel 8257x, for
1312 example with the "sspi" command.
1315 Management command for E1000 devices. When used on devices
1316 with SPI support you can reprogram the EEPROM from U-Boot.
1319 Support for Intel 82557/82559/82559ER chips.
1320 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1321 write routine for first time initialisation.
1324 Support for Digital 2114x chips.
1325 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1326 modem chip initialisation (KS8761/QS6611).
1329 Support for National dp83815 chips.
1332 Support for National dp8382[01] gigabit chips.
1334 - NETWORK Support (other):
1336 CONFIG_DRIVER_AT91EMAC
1337 Support for AT91RM9200 EMAC.
1340 Define this to use reduced MII inteface
1342 CONFIG_DRIVER_AT91EMAC_QUIET
1343 If this defined, the driver is quiet.
1344 The driver doen't show link status messages.
1346 CONFIG_CALXEDA_XGMAC
1347 Support for the Calxeda XGMAC device
1350 Support for SMSC's LAN91C96 chips.
1352 CONFIG_LAN91C96_BASE
1353 Define this to hold the physical address
1354 of the LAN91C96's I/O space
1356 CONFIG_LAN91C96_USE_32_BIT
1357 Define this to enable 32 bit addressing
1360 Support for SMSC's LAN91C111 chip
1362 CONFIG_SMC91111_BASE
1363 Define this to hold the physical address
1364 of the device (I/O space)
1366 CONFIG_SMC_USE_32_BIT
1367 Define this if data bus is 32 bits
1369 CONFIG_SMC_USE_IOFUNCS
1370 Define this to use i/o functions instead of macros
1371 (some hardware wont work with macros)
1373 CONFIG_DRIVER_TI_EMAC
1374 Support for davinci emac
1376 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1377 Define this if you have more then 3 PHYs.
1380 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1382 CONFIG_FTGMAC100_EGIGA
1383 Define this to use GE link update with gigabit PHY.
1384 Define this if FTGMAC100 is connected to gigabit PHY.
1385 If your system has 10/100 PHY only, it might not occur
1386 wrong behavior. Because PHY usually return timeout or
1387 useless data when polling gigabit status and gigabit
1388 control registers. This behavior won't affect the
1389 correctnessof 10/100 link speed update.
1392 Support for SMSC's LAN911x and LAN921x chips
1395 Define this to hold the physical address
1396 of the device (I/O space)
1398 CONFIG_SMC911X_32_BIT
1399 Define this if data bus is 32 bits
1401 CONFIG_SMC911X_16_BIT
1402 Define this if data bus is 16 bits. If your processor
1403 automatically converts one 32 bit word to two 16 bit
1404 words you may also try CONFIG_SMC911X_32_BIT.
1407 Support for Renesas on-chip Ethernet controller
1409 CONFIG_SH_ETHER_USE_PORT
1410 Define the number of ports to be used
1412 CONFIG_SH_ETHER_PHY_ADDR
1413 Define the ETH PHY's address
1415 CONFIG_SH_ETHER_CACHE_WRITEBACK
1416 If this option is set, the driver enables cache flush.
1420 Support for PWM modul on the imx6.
1424 Support TPM devices.
1426 CONFIG_TPM_TIS_INFINEON
1427 Support for Infineon i2c bus TPM devices. Only one device
1428 per system is supported at this time.
1430 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1431 Define the burst count bytes upper limit
1434 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1436 CONFIG_TPM_ST33ZP24_I2C
1437 Support for STMicroelectronics ST33ZP24 I2C devices.
1438 Requires TPM_ST33ZP24 and I2C.
1440 CONFIG_TPM_ST33ZP24_SPI
1441 Support for STMicroelectronics ST33ZP24 SPI devices.
1442 Requires TPM_ST33ZP24 and SPI.
1444 CONFIG_TPM_ATMEL_TWI
1445 Support for Atmel TWI TPM device. Requires I2C support.
1448 Support for generic parallel port TPM devices. Only one device
1449 per system is supported at this time.
1451 CONFIG_TPM_TIS_BASE_ADDRESS
1452 Base address where the generic TPM device is mapped
1453 to. Contemporary x86 systems usually map it at
1457 Add tpm monitor functions.
1458 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1459 provides monitor access to authorized functions.
1462 Define this to enable the TPM support library which provides
1463 functional interfaces to some TPM commands.
1464 Requires support for a TPM device.
1466 CONFIG_TPM_AUTH_SESSIONS
1467 Define this to enable authorized functions in the TPM library.
1468 Requires CONFIG_TPM and CONFIG_SHA1.
1471 At the moment only the UHCI host controller is
1472 supported (PIP405, MIP405, MPC5200); define
1473 CONFIG_USB_UHCI to enable it.
1474 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1475 and define CONFIG_USB_STORAGE to enable the USB
1478 Supported are USB Keyboards and USB Floppy drives
1480 MPC5200 USB requires additional defines:
1482 for 528 MHz Clock: 0x0001bbbb
1486 for differential drivers: 0x00001000
1487 for single ended drivers: 0x00005000
1488 for differential drivers on PSC3: 0x00000100
1489 for single ended drivers on PSC3: 0x00004100
1490 CONFIG_SYS_USB_EVENT_POLL
1491 May be defined to allow interrupt polling
1492 instead of using asynchronous interrupts
1494 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1495 txfilltuning field in the EHCI controller on reset.
1497 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1498 HW module registers.
1501 Define the below if you wish to use the USB console.
1502 Once firmware is rebuilt from a serial console issue the
1503 command "setenv stdin usbtty; setenv stdout usbtty" and
1504 attach your USB cable. The Unix command "dmesg" should print
1505 it has found a new device. The environment variable usbtty
1506 can be set to gserial or cdc_acm to enable your device to
1507 appear to a USB host as a Linux gserial device or a
1508 Common Device Class Abstract Control Model serial device.
1509 If you select usbtty = gserial you should be able to enumerate
1511 # modprobe usbserial vendor=0xVendorID product=0xProductID
1512 else if using cdc_acm, simply setting the environment
1513 variable usbtty to be cdc_acm should suffice. The following
1514 might be defined in YourBoardName.h
1517 Define this to build a UDC device
1520 Define this to have a tty type of device available to
1521 talk to the UDC device
1524 Define this to enable the high speed support for usb
1525 device and usbtty. If this feature is enabled, a routine
1526 int is_usbd_high_speed(void)
1527 also needs to be defined by the driver to dynamically poll
1528 whether the enumeration has succeded at high speed or full
1531 CONFIG_SYS_CONSOLE_IS_IN_ENV
1532 Define this if you want stdin, stdout &/or stderr to
1536 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1537 Derive USB clock from external clock "blah"
1538 - CONFIG_SYS_USB_EXTC_CLK 0x02
1540 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1541 Derive USB clock from brgclk
1542 - CONFIG_SYS_USB_BRG_CLK 0x04
1544 If you have a USB-IF assigned VendorID then you may wish to
1545 define your own vendor specific values either in BoardName.h
1546 or directly in usbd_vendor_info.h. If you don't define
1547 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1548 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1549 should pretend to be a Linux device to it's target host.
1551 CONFIG_USBD_MANUFACTURER
1552 Define this string as the name of your company for
1553 - CONFIG_USBD_MANUFACTURER "my company"
1555 CONFIG_USBD_PRODUCT_NAME
1556 Define this string as the name of your product
1557 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1559 CONFIG_USBD_VENDORID
1560 Define this as your assigned Vendor ID from the USB
1561 Implementors Forum. This *must* be a genuine Vendor ID
1562 to avoid polluting the USB namespace.
1563 - CONFIG_USBD_VENDORID 0xFFFF
1565 CONFIG_USBD_PRODUCTID
1566 Define this as the unique Product ID
1568 - CONFIG_USBD_PRODUCTID 0xFFFF
1570 - ULPI Layer Support:
1571 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1572 the generic ULPI layer. The generic layer accesses the ULPI PHY
1573 via the platform viewport, so you need both the genric layer and
1574 the viewport enabled. Currently only Chipidea/ARC based
1575 viewport is supported.
1576 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1577 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1578 If your ULPI phy needs a different reference clock than the
1579 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1580 the appropriate value in Hz.
1583 The MMC controller on the Intel PXA is supported. To
1584 enable this define CONFIG_MMC. The MMC can be
1585 accessed from the boot prompt by mapping the device
1586 to physical memory similar to flash. Command line is
1587 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1588 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1591 Support for Renesas on-chip MMCIF controller
1593 CONFIG_SH_MMCIF_ADDR
1594 Define the base address of MMCIF registers
1597 Define the clock frequency for MMCIF
1600 Enable the generic MMC driver
1602 CONFIG_SUPPORT_EMMC_BOOT
1603 Enable some additional features of the eMMC boot partitions.
1605 CONFIG_SUPPORT_EMMC_RPMB
1606 Enable the commands for reading, writing and programming the
1607 key for the Replay Protection Memory Block partition in eMMC.
1609 - USB Device Firmware Update (DFU) class support:
1610 CONFIG_USB_FUNCTION_DFU
1611 This enables the USB portion of the DFU USB class
1614 This enables the command "dfu" which is used to have
1615 U-Boot create a DFU class device via USB. This command
1616 requires that the "dfu_alt_info" environment variable be
1617 set and define the alt settings to expose to the host.
1620 This enables support for exposing (e)MMC devices via DFU.
1623 This enables support for exposing NAND devices via DFU.
1626 This enables support for exposing RAM via DFU.
1627 Note: DFU spec refer to non-volatile memory usage, but
1628 allow usages beyond the scope of spec - here RAM usage,
1629 one that would help mostly the developer.
1631 CONFIG_SYS_DFU_DATA_BUF_SIZE
1632 Dfu transfer uses a buffer before writing data to the
1633 raw storage device. Make the size (in bytes) of this buffer
1634 configurable. The size of this buffer is also configurable
1635 through the "dfu_bufsiz" environment variable.
1637 CONFIG_SYS_DFU_MAX_FILE_SIZE
1638 When updating files rather than the raw storage device,
1639 we use a static buffer to copy the file into and then write
1640 the buffer once we've been given the whole file. Define
1641 this to the maximum filesize (in bytes) for the buffer.
1642 Default is 4 MiB if undefined.
1644 DFU_DEFAULT_POLL_TIMEOUT
1645 Poll timeout [ms], is the timeout a device can send to the
1646 host. The host must wait for this timeout before sending
1647 a subsequent DFU_GET_STATUS request to the device.
1649 DFU_MANIFEST_POLL_TIMEOUT
1650 Poll timeout [ms], which the device sends to the host when
1651 entering dfuMANIFEST state. Host waits this timeout, before
1652 sending again an USB request to the device.
1654 - USB Device Android Fastboot support:
1655 CONFIG_USB_FUNCTION_FASTBOOT
1656 This enables the USB part of the fastboot gadget
1659 This enables the command "fastboot" which enables the Android
1660 fastboot mode for the platform's USB device. Fastboot is a USB
1661 protocol for downloading images, flashing and device control
1662 used on Android devices.
1663 See doc/README.android-fastboot for more information.
1665 CONFIG_ANDROID_BOOT_IMAGE
1666 This enables support for booting images which use the Android
1667 image format header.
1669 CONFIG_FASTBOOT_BUF_ADDR
1670 The fastboot protocol requires a large memory buffer for
1671 downloads. Define this to the starting RAM address to use for
1674 CONFIG_FASTBOOT_BUF_SIZE
1675 The fastboot protocol requires a large memory buffer for
1676 downloads. This buffer should be as large as possible for a
1677 platform. Define this to the size available RAM for fastboot.
1679 CONFIG_FASTBOOT_FLASH
1680 The fastboot protocol includes a "flash" command for writing
1681 the downloaded image to a non-volatile storage device. Define
1682 this to enable the "fastboot flash" command.
1684 CONFIG_FASTBOOT_FLASH_MMC_DEV
1685 The fastboot "flash" command requires additional information
1686 regarding the non-volatile storage device. Define this to
1687 the eMMC device that fastboot should use to store the image.
1689 CONFIG_FASTBOOT_GPT_NAME
1690 The fastboot "flash" command supports writing the downloaded
1691 image to the Protective MBR and the Primary GUID Partition
1692 Table. (Additionally, this downloaded image is post-processed
1693 to generate and write the Backup GUID Partition Table.)
1694 This occurs when the specified "partition name" on the
1695 "fastboot flash" command line matches this value.
1696 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1698 - Journaling Flash filesystem support:
1699 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1700 CONFIG_JFFS2_NAND_DEV
1701 Define these for a default partition on a NAND device
1703 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1704 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1705 Define these for a default partition on a NOR device
1707 CONFIG_SYS_JFFS_CUSTOM_PART
1708 Define this to create an own partition. You have to provide a
1709 function struct part_info* jffs2_part_info(int part_num)
1711 If you define only one JFFS2 partition you may also want to
1712 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1713 to disable the command chpart. This is the default when you
1714 have not defined a custom partition
1716 - FAT(File Allocation Table) filesystem write function support:
1719 Define this to enable support for saving memory data as a
1720 file in FAT formatted partition.
1722 This will also enable the command "fatwrite" enabling the
1723 user to write files to FAT.
1725 CBFS (Coreboot Filesystem) support
1728 Define this to enable support for reading from a Coreboot
1729 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1732 - FAT(File Allocation Table) filesystem cluster size:
1733 CONFIG_FS_FAT_MAX_CLUSTSIZE
1735 Define the max cluster size for fat operations else
1736 a default value of 65536 will be defined.
1739 See Kconfig help for available keyboard drivers.
1743 Define this to enable a custom keyboard support.
1744 This simply calls drv_keyboard_init() which must be
1745 defined in your board-specific files. This option is deprecated
1746 and is only used by novena. For new boards, use driver model
1752 Define this to enable video support (for output to
1755 CONFIG_VIDEO_CT69000
1757 Enable Chips & Technologies 69000 Video chip
1759 CONFIG_VIDEO_SMI_LYNXEM
1760 Enable Silicon Motion SMI 712/710/810 Video chip. The
1761 video output is selected via environment 'videoout'
1762 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1765 For the CT69000 and SMI_LYNXEM drivers, videomode is
1766 selected via environment 'videomode'. Two different ways
1768 - "videomode=num" 'num' is a standard LiLo mode numbers.
1769 Following standard modes are supported (* is default):
1771 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1772 -------------+---------------------------------------------
1773 8 bits | 0x301* 0x303 0x305 0x161 0x307
1774 15 bits | 0x310 0x313 0x316 0x162 0x319
1775 16 bits | 0x311 0x314 0x317 0x163 0x31A
1776 24 bits | 0x312 0x315 0x318 ? 0x31B
1777 -------------+---------------------------------------------
1778 (i.e. setenv videomode 317; saveenv; reset;)
1780 - "videomode=bootargs" all the video parameters are parsed
1781 from the bootargs. (See drivers/video/videomodes.c)
1784 CONFIG_VIDEO_SED13806
1785 Enable Epson SED13806 driver. This driver supports 8bpp
1786 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1787 or CONFIG_VIDEO_SED13806_16BPP
1790 Enable the Freescale DIU video driver. Reference boards for
1791 SOCs that have a DIU should define this macro to enable DIU
1792 support, and should also define these other macros:
1798 CONFIG_VIDEO_SW_CURSOR
1799 CONFIG_VGA_AS_SINGLE_DEVICE
1801 CONFIG_VIDEO_BMP_LOGO
1803 The DIU driver will look for the 'video-mode' environment
1804 variable, and if defined, enable the DIU as a console during
1805 boot. See the documentation file doc/README.video for a
1806 description of this variable.
1808 - LCD Support: CONFIG_LCD
1810 Define this to enable LCD support (for output to LCD
1811 display); also select one of the supported displays
1812 by defining one of these:
1816 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1818 CONFIG_NEC_NL6448AC33:
1820 NEC NL6448AC33-18. Active, color, single scan.
1822 CONFIG_NEC_NL6448BC20
1824 NEC NL6448BC20-08. 6.5", 640x480.
1825 Active, color, single scan.
1827 CONFIG_NEC_NL6448BC33_54
1829 NEC NL6448BC33-54. 10.4", 640x480.
1830 Active, color, single scan.
1834 Sharp 320x240. Active, color, single scan.
1835 It isn't 16x9, and I am not sure what it is.
1837 CONFIG_SHARP_LQ64D341
1839 Sharp LQ64D341 display, 640x480.
1840 Active, color, single scan.
1844 HLD1045 display, 640x480.
1845 Active, color, single scan.
1849 Optrex CBL50840-2 NF-FW 99 22 M5
1851 Hitachi LMG6912RPFC-00T
1855 320x240. Black & white.
1857 Normally display is black on white background; define
1858 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1860 CONFIG_LCD_ALIGNMENT
1862 Normally the LCD is page-aligned (typically 4KB). If this is
1863 defined then the LCD will be aligned to this value instead.
1864 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1865 here, since it is cheaper to change data cache settings on
1866 a per-section basis.
1868 CONFIG_CONSOLE_SCROLL_LINES
1870 When the console need to be scrolled, this is the number of
1871 lines to scroll by. It defaults to 1. Increasing this makes
1872 the console jump but can help speed up operation when scrolling
1877 Sometimes, for example if the display is mounted in portrait
1878 mode or even if it's mounted landscape but rotated by 180degree,
1879 we need to rotate our content of the display relative to the
1880 framebuffer, so that user can read the messages which are
1882 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1883 initialized with a given rotation from "vl_rot" out of
1884 "vidinfo_t" which is provided by the board specific code.
1885 The value for vl_rot is coded as following (matching to
1886 fbcon=rotate:<n> linux-kernel commandline):
1887 0 = no rotation respectively 0 degree
1888 1 = 90 degree rotation
1889 2 = 180 degree rotation
1890 3 = 270 degree rotation
1892 If CONFIG_LCD_ROTATION is not defined, the console will be
1893 initialized with 0degree rotation.
1897 Support drawing of RLE8-compressed bitmaps on the LCD.
1901 Enables an 'i2c edid' command which can read EDID
1902 information over I2C from an attached LCD display.
1904 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1906 If this option is set, the environment is checked for
1907 a variable "splashimage". If found, the usual display
1908 of logo, copyright and system information on the LCD
1909 is suppressed and the BMP image at the address
1910 specified in "splashimage" is loaded instead. The
1911 console is redirected to the "nulldev", too. This
1912 allows for a "silent" boot where a splash screen is
1913 loaded very quickly after power-on.
1915 CONFIG_SPLASHIMAGE_GUARD
1917 If this option is set, then U-Boot will prevent the environment
1918 variable "splashimage" from being set to a problematic address
1919 (see doc/README.displaying-bmps).
1920 This option is useful for targets where, due to alignment
1921 restrictions, an improperly aligned BMP image will cause a data
1922 abort. If you think you will not have problems with unaligned
1923 accesses (for example because your toolchain prevents them)
1924 there is no need to set this option.
1926 CONFIG_SPLASH_SCREEN_ALIGN
1928 If this option is set the splash image can be freely positioned
1929 on the screen. Environment variable "splashpos" specifies the
1930 position as "x,y". If a positive number is given it is used as
1931 number of pixel from left/top. If a negative number is given it
1932 is used as number of pixel from right/bottom. You can also
1933 specify 'm' for centering the image.
1936 setenv splashpos m,m
1937 => image at center of screen
1939 setenv splashpos 30,20
1940 => image at x = 30 and y = 20
1942 setenv splashpos -10,m
1943 => vertically centered image
1944 at x = dspWidth - bmpWidth - 9
1946 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1948 If this option is set, additionally to standard BMP
1949 images, gzipped BMP images can be displayed via the
1950 splashscreen support or the bmp command.
1952 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1954 If this option is set, 8-bit RLE compressed BMP images
1955 can be displayed via the splashscreen support or the
1958 - Do compressing for memory range:
1961 If this option is set, it would use zlib deflate method
1962 to compress the specified memory at its best effort.
1964 - Compression support:
1967 Enabled by default to support gzip compressed images.
1971 If this option is set, support for bzip2 compressed
1972 images is included. If not, only uncompressed and gzip
1973 compressed images are supported.
1975 NOTE: the bzip2 algorithm requires a lot of RAM, so
1976 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1981 If this option is set, support for lzma compressed
1984 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1985 requires an amount of dynamic memory that is given by the
1988 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1990 Where lc and lp stand for, respectively, Literal context bits
1991 and Literal pos bits.
1993 This value is upper-bounded by 14MB in the worst case. Anyway,
1994 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1995 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1996 a very small buffer.
1998 Use the lzmainfo tool to determinate the lc and lp values and
1999 then calculate the amount of needed dynamic memory (ensuring
2000 the appropriate CONFIG_SYS_MALLOC_LEN value).
2004 If this option is set, support for LZO compressed images
2010 The address of PHY on MII bus.
2012 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2014 The clock frequency of the MII bus
2018 If this option is set, support for speed/duplex
2019 detection of gigabit PHY is included.
2021 CONFIG_PHY_RESET_DELAY
2023 Some PHY like Intel LXT971A need extra delay after
2024 reset before any MII register access is possible.
2025 For such PHY, set this option to the usec delay
2026 required. (minimum 300usec for LXT971A)
2028 CONFIG_PHY_CMD_DELAY (ppc4xx)
2030 Some PHY like Intel LXT971A need extra delay after
2031 command issued before MII status register can be read
2036 Define a default value for the IP address to use for
2037 the default Ethernet interface, in case this is not
2038 determined through e.g. bootp.
2039 (Environment variable "ipaddr")
2041 - Server IP address:
2044 Defines a default value for the IP address of a TFTP
2045 server to contact when using the "tftboot" command.
2046 (Environment variable "serverip")
2048 CONFIG_KEEP_SERVERADDR
2050 Keeps the server's MAC address, in the env 'serveraddr'
2051 for passing to bootargs (like Linux's netconsole option)
2053 - Gateway IP address:
2056 Defines a default value for the IP address of the
2057 default router where packets to other networks are
2059 (Environment variable "gatewayip")
2064 Defines a default value for the subnet mask (or
2065 routing prefix) which is used to determine if an IP
2066 address belongs to the local subnet or needs to be
2067 forwarded through a router.
2068 (Environment variable "netmask")
2070 - Multicast TFTP Mode:
2073 Defines whether you want to support multicast TFTP as per
2074 rfc-2090; for example to work with atftp. Lets lots of targets
2075 tftp down the same boot image concurrently. Note: the Ethernet
2076 driver in use must provide a function: mcast() to join/leave a
2079 - BOOTP Recovery Mode:
2080 CONFIG_BOOTP_RANDOM_DELAY
2082 If you have many targets in a network that try to
2083 boot using BOOTP, you may want to avoid that all
2084 systems send out BOOTP requests at precisely the same
2085 moment (which would happen for instance at recovery
2086 from a power failure, when all systems will try to
2087 boot, thus flooding the BOOTP server. Defining
2088 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2089 inserted before sending out BOOTP requests. The
2090 following delays are inserted then:
2092 1st BOOTP request: delay 0 ... 1 sec
2093 2nd BOOTP request: delay 0 ... 2 sec
2094 3rd BOOTP request: delay 0 ... 4 sec
2096 BOOTP requests: delay 0 ... 8 sec
2098 CONFIG_BOOTP_ID_CACHE_SIZE
2100 BOOTP packets are uniquely identified using a 32-bit ID. The
2101 server will copy the ID from client requests to responses and
2102 U-Boot will use this to determine if it is the destination of
2103 an incoming response. Some servers will check that addresses
2104 aren't in use before handing them out (usually using an ARP
2105 ping) and therefore take up to a few hundred milliseconds to
2106 respond. Network congestion may also influence the time it
2107 takes for a response to make it back to the client. If that
2108 time is too long, U-Boot will retransmit requests. In order
2109 to allow earlier responses to still be accepted after these
2110 retransmissions, U-Boot's BOOTP client keeps a small cache of
2111 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2112 cache. The default is to keep IDs for up to four outstanding
2113 requests. Increasing this will allow U-Boot to accept offers
2114 from a BOOTP client in networks with unusually high latency.
2116 - DHCP Advanced Options:
2117 You can fine tune the DHCP functionality by defining
2118 CONFIG_BOOTP_* symbols:
2120 CONFIG_BOOTP_SUBNETMASK
2121 CONFIG_BOOTP_GATEWAY
2122 CONFIG_BOOTP_HOSTNAME
2123 CONFIG_BOOTP_NISDOMAIN
2124 CONFIG_BOOTP_BOOTPATH
2125 CONFIG_BOOTP_BOOTFILESIZE
2128 CONFIG_BOOTP_SEND_HOSTNAME
2129 CONFIG_BOOTP_NTPSERVER
2130 CONFIG_BOOTP_TIMEOFFSET
2131 CONFIG_BOOTP_VENDOREX
2132 CONFIG_BOOTP_MAY_FAIL
2134 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2135 environment variable, not the BOOTP server.
2137 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2138 after the configured retry count, the call will fail
2139 instead of starting over. This can be used to fail over
2140 to Link-local IP address configuration if the DHCP server
2143 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2144 serverip from a DHCP server, it is possible that more
2145 than one DNS serverip is offered to the client.
2146 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2147 serverip will be stored in the additional environment
2148 variable "dnsip2". The first DNS serverip is always
2149 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2152 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2153 to do a dynamic update of a DNS server. To do this, they
2154 need the hostname of the DHCP requester.
2155 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2156 of the "hostname" environment variable is passed as
2157 option 12 to the DHCP server.
2159 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2161 A 32bit value in microseconds for a delay between
2162 receiving a "DHCP Offer" and sending the "DHCP Request".
2163 This fixes a problem with certain DHCP servers that don't
2164 respond 100% of the time to a "DHCP request". E.g. On an
2165 AT91RM9200 processor running at 180MHz, this delay needed
2166 to be *at least* 15,000 usec before a Windows Server 2003
2167 DHCP server would reply 100% of the time. I recommend at
2168 least 50,000 usec to be safe. The alternative is to hope
2169 that one of the retries will be successful but note that
2170 the DHCP timeout and retry process takes a longer than
2173 - Link-local IP address negotiation:
2174 Negotiate with other link-local clients on the local network
2175 for an address that doesn't require explicit configuration.
2176 This is especially useful if a DHCP server cannot be guaranteed
2177 to exist in all environments that the device must operate.
2179 See doc/README.link-local for more information.
2182 CONFIG_CDP_DEVICE_ID
2184 The device id used in CDP trigger frames.
2186 CONFIG_CDP_DEVICE_ID_PREFIX
2188 A two character string which is prefixed to the MAC address
2193 A printf format string which contains the ascii name of
2194 the port. Normally is set to "eth%d" which sets
2195 eth0 for the first Ethernet, eth1 for the second etc.
2197 CONFIG_CDP_CAPABILITIES
2199 A 32bit integer which indicates the device capabilities;
2200 0x00000010 for a normal host which does not forwards.
2204 An ascii string containing the version of the software.
2208 An ascii string containing the name of the platform.
2212 A 32bit integer sent on the trigger.
2214 CONFIG_CDP_POWER_CONSUMPTION
2216 A 16bit integer containing the power consumption of the
2217 device in .1 of milliwatts.
2219 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2221 A byte containing the id of the VLAN.
2223 - Status LED: CONFIG_STATUS_LED
2225 Several configurations allow to display the current
2226 status using a LED. For instance, the LED will blink
2227 fast while running U-Boot code, stop blinking as
2228 soon as a reply to a BOOTP request was received, and
2229 start blinking slow once the Linux kernel is running
2230 (supported by a status LED driver in the Linux
2231 kernel). Defining CONFIG_STATUS_LED enables this
2237 The status LED can be connected to a GPIO pin.
2238 In such cases, the gpio_led driver can be used as a
2239 status LED backend implementation. Define CONFIG_GPIO_LED
2240 to include the gpio_led driver in the U-Boot binary.
2242 CONFIG_GPIO_LED_INVERTED_TABLE
2243 Some GPIO connected LEDs may have inverted polarity in which
2244 case the GPIO high value corresponds to LED off state and
2245 GPIO low value corresponds to LED on state.
2246 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2247 with a list of GPIO LEDs that have inverted polarity.
2249 - CAN Support: CONFIG_CAN_DRIVER
2251 Defining CONFIG_CAN_DRIVER enables CAN driver support
2252 on those systems that support this (optional)
2253 feature, like the TQM8xxL modules.
2255 - I2C Support: CONFIG_SYS_I2C
2257 This enable the NEW i2c subsystem, and will allow you to use
2258 i2c commands at the u-boot command line (as long as you set
2259 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2260 based realtime clock chips or other i2c devices. See
2261 common/cmd_i2c.c for a description of the command line
2264 ported i2c driver to the new framework:
2265 - drivers/i2c/soft_i2c.c:
2266 - activate first bus with CONFIG_SYS_I2C_SOFT define
2267 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2268 for defining speed and slave address
2269 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2270 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2271 for defining speed and slave address
2272 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2273 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2274 for defining speed and slave address
2275 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2276 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2277 for defining speed and slave address
2279 - drivers/i2c/fsl_i2c.c:
2280 - activate i2c driver with CONFIG_SYS_I2C_FSL
2281 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2282 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2283 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2285 - If your board supports a second fsl i2c bus, define
2286 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2287 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2288 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2291 - drivers/i2c/tegra_i2c.c:
2292 - activate this driver with CONFIG_SYS_I2C_TEGRA
2293 - This driver adds 4 i2c buses with a fix speed from
2294 100000 and the slave addr 0!
2296 - drivers/i2c/ppc4xx_i2c.c
2297 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2298 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2299 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2301 - drivers/i2c/i2c_mxc.c
2302 - activate this driver with CONFIG_SYS_I2C_MXC
2303 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2304 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2305 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2306 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2307 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2308 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2309 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2310 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2311 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2312 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2313 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2314 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2315 If those defines are not set, default value is 100000
2316 for speed, and 0 for slave.
2318 - drivers/i2c/rcar_i2c.c:
2319 - activate this driver with CONFIG_SYS_I2C_RCAR
2320 - This driver adds 4 i2c buses
2322 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2323 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2324 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2325 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2326 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2327 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2328 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2329 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2330 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2332 - drivers/i2c/sh_i2c.c:
2333 - activate this driver with CONFIG_SYS_I2C_SH
2334 - This driver adds from 2 to 5 i2c buses
2336 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2337 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2338 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2339 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2340 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2341 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2342 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2343 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2344 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2345 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2346 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2347 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2348 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2350 - drivers/i2c/omap24xx_i2c.c
2351 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2352 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2353 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2354 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2355 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2356 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2357 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2358 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2359 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2360 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2361 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2363 - drivers/i2c/zynq_i2c.c
2364 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2365 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2366 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2368 - drivers/i2c/s3c24x0_i2c.c:
2369 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2370 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2371 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2372 with a fix speed from 100000 and the slave addr 0!
2374 - drivers/i2c/ihs_i2c.c
2375 - activate this driver with CONFIG_SYS_I2C_IHS
2376 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2377 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2378 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2379 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2380 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2381 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2382 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2383 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2384 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2385 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2386 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2387 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2388 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2389 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2390 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2391 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2392 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2393 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2394 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2395 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2396 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2400 CONFIG_SYS_NUM_I2C_BUSES
2401 Hold the number of i2c buses you want to use. If you
2402 don't use/have i2c muxes on your i2c bus, this
2403 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2406 CONFIG_SYS_I2C_DIRECT_BUS
2407 define this, if you don't use i2c muxes on your hardware.
2408 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2411 CONFIG_SYS_I2C_MAX_HOPS
2412 define how many muxes are maximal consecutively connected
2413 on one i2c bus. If you not use i2c muxes, omit this
2416 CONFIG_SYS_I2C_BUSES
2417 hold a list of buses you want to use, only used if
2418 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2419 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2420 CONFIG_SYS_NUM_I2C_BUSES = 9:
2422 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2423 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2424 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2425 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2426 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2427 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2428 {1, {I2C_NULL_HOP}}, \
2429 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2430 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2434 bus 0 on adapter 0 without a mux
2435 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2436 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2437 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2438 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2439 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2440 bus 6 on adapter 1 without a mux
2441 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2442 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2444 If you do not have i2c muxes on your board, omit this define.
2446 - Legacy I2C Support: CONFIG_HARD_I2C
2448 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2449 provides the following compelling advantages:
2451 - more than one i2c adapter is usable
2452 - approved multibus support
2453 - better i2c mux support
2455 ** Please consider updating your I2C driver now. **
2457 These enable legacy I2C serial bus commands. Defining
2458 CONFIG_HARD_I2C will include the appropriate I2C driver
2459 for the selected CPU.
2461 This will allow you to use i2c commands at the u-boot
2462 command line (as long as you set CONFIG_CMD_I2C in
2463 CONFIG_COMMANDS) and communicate with i2c based realtime
2464 clock chips. See common/cmd_i2c.c for a description of the
2465 command line interface.
2467 CONFIG_HARD_I2C selects a hardware I2C controller.
2469 There are several other quantities that must also be
2470 defined when you define CONFIG_HARD_I2C.
2472 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2473 to be the frequency (in Hz) at which you wish your i2c bus
2474 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2475 the CPU's i2c node address).
2477 Now, the u-boot i2c code for the mpc8xx
2478 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2479 and so its address should therefore be cleared to 0 (See,
2480 eg, MPC823e User's Manual p.16-473). So, set
2481 CONFIG_SYS_I2C_SLAVE to 0.
2483 CONFIG_SYS_I2C_INIT_MPC5XXX
2485 When a board is reset during an i2c bus transfer
2486 chips might think that the current transfer is still
2487 in progress. Reset the slave devices by sending start
2488 commands until the slave device responds.
2490 That's all that's required for CONFIG_HARD_I2C.
2492 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2493 then the following macros need to be defined (examples are
2494 from include/configs/lwmon.h):
2498 (Optional). Any commands necessary to enable the I2C
2499 controller or configure ports.
2501 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2505 (Only for MPC8260 CPU). The I/O port to use (the code
2506 assumes both bits are on the same port). Valid values
2507 are 0..3 for ports A..D.
2511 The code necessary to make the I2C data line active
2512 (driven). If the data line is open collector, this
2515 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2519 The code necessary to make the I2C data line tri-stated
2520 (inactive). If the data line is open collector, this
2523 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2527 Code that returns true if the I2C data line is high,
2530 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2534 If <bit> is true, sets the I2C data line high. If it
2535 is false, it clears it (low).
2537 eg: #define I2C_SDA(bit) \
2538 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2539 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2543 If <bit> is true, sets the I2C clock line high. If it
2544 is false, it clears it (low).
2546 eg: #define I2C_SCL(bit) \
2547 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2548 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2552 This delay is invoked four times per clock cycle so this
2553 controls the rate of data transfer. The data rate thus
2554 is 1 / (I2C_DELAY * 4). Often defined to be something
2557 #define I2C_DELAY udelay(2)
2559 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2561 If your arch supports the generic GPIO framework (asm/gpio.h),
2562 then you may alternatively define the two GPIOs that are to be
2563 used as SCL / SDA. Any of the previous I2C_xxx macros will
2564 have GPIO-based defaults assigned to them as appropriate.
2566 You should define these to the GPIO value as given directly to
2567 the generic GPIO functions.
2569 CONFIG_SYS_I2C_INIT_BOARD
2571 When a board is reset during an i2c bus transfer
2572 chips might think that the current transfer is still
2573 in progress. On some boards it is possible to access
2574 the i2c SCLK line directly, either by using the
2575 processor pin as a GPIO or by having a second pin
2576 connected to the bus. If this option is defined a
2577 custom i2c_init_board() routine in boards/xxx/board.c
2578 is run early in the boot sequence.
2580 CONFIG_SYS_I2C_BOARD_LATE_INIT
2582 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2583 defined a custom i2c_board_late_init() routine in
2584 boards/xxx/board.c is run AFTER the operations in i2c_init()
2585 is completed. This callpoint can be used to unreset i2c bus
2586 using CPU i2c controller register accesses for CPUs whose i2c
2587 controller provide such a method. It is called at the end of
2588 i2c_init() to allow i2c_init operations to setup the i2c bus
2589 controller on the CPU (e.g. setting bus speed & slave address).
2591 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2593 This option enables configuration of bi_iic_fast[] flags
2594 in u-boot bd_info structure based on u-boot environment
2595 variable "i2cfast". (see also i2cfast)
2597 CONFIG_I2C_MULTI_BUS
2599 This option allows the use of multiple I2C buses, each of which
2600 must have a controller. At any point in time, only one bus is
2601 active. To switch to a different bus, use the 'i2c dev' command.
2602 Note that bus numbering is zero-based.
2604 CONFIG_SYS_I2C_NOPROBES
2606 This option specifies a list of I2C devices that will be skipped
2607 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2608 is set, specify a list of bus-device pairs. Otherwise, specify
2609 a 1D array of device addresses
2612 #undef CONFIG_I2C_MULTI_BUS
2613 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2615 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2617 #define CONFIG_I2C_MULTI_BUS
2618 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2620 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2622 CONFIG_SYS_SPD_BUS_NUM
2624 If defined, then this indicates the I2C bus number for DDR SPD.
2625 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2627 CONFIG_SYS_RTC_BUS_NUM
2629 If defined, then this indicates the I2C bus number for the RTC.
2630 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2632 CONFIG_SYS_DTT_BUS_NUM
2634 If defined, then this indicates the I2C bus number for the DTT.
2635 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2637 CONFIG_SYS_I2C_DTT_ADDR:
2639 If defined, specifies the I2C address of the DTT device.
2640 If not defined, then U-Boot uses predefined value for
2641 specified DTT device.
2643 CONFIG_SOFT_I2C_READ_REPEATED_START
2645 defining this will force the i2c_read() function in
2646 the soft_i2c driver to perform an I2C repeated start
2647 between writing the address pointer and reading the
2648 data. If this define is omitted the default behaviour
2649 of doing a stop-start sequence will be used. Most I2C
2650 devices can use either method, but some require one or
2653 - SPI Support: CONFIG_SPI
2655 Enables SPI driver (so far only tested with
2656 SPI EEPROM, also an instance works with Crystal A/D and
2657 D/As on the SACSng board)
2661 Enables the driver for SPI controller on SuperH. Currently
2662 only SH7757 is supported.
2666 Enables a software (bit-bang) SPI driver rather than
2667 using hardware support. This is a general purpose
2668 driver that only requires three general I/O port pins
2669 (two outputs, one input) to function. If this is
2670 defined, the board configuration must define several
2671 SPI configuration items (port pins to use, etc). For
2672 an example, see include/configs/sacsng.h.
2676 Enables a hardware SPI driver for general-purpose reads
2677 and writes. As with CONFIG_SOFT_SPI, the board configuration
2678 must define a list of chip-select function pointers.
2679 Currently supported on some MPC8xxx processors. For an
2680 example, see include/configs/mpc8349emds.h.
2684 Enables the driver for the SPI controllers on i.MX and MXC
2685 SoCs. Currently i.MX31/35/51 are supported.
2687 CONFIG_SYS_SPI_MXC_WAIT
2688 Timeout for waiting until spi transfer completed.
2689 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2691 - FPGA Support: CONFIG_FPGA
2693 Enables FPGA subsystem.
2695 CONFIG_FPGA_<vendor>
2697 Enables support for specific chip vendors.
2700 CONFIG_FPGA_<family>
2702 Enables support for FPGA family.
2703 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2707 Specify the number of FPGA devices to support.
2709 CONFIG_CMD_FPGA_LOADMK
2711 Enable support for fpga loadmk command
2713 CONFIG_CMD_FPGA_LOADP
2715 Enable support for fpga loadp command - load partial bitstream
2717 CONFIG_CMD_FPGA_LOADBP
2719 Enable support for fpga loadbp command - load partial bitstream
2722 CONFIG_SYS_FPGA_PROG_FEEDBACK
2724 Enable printing of hash marks during FPGA configuration.
2726 CONFIG_SYS_FPGA_CHECK_BUSY
2728 Enable checks on FPGA configuration interface busy
2729 status by the configuration function. This option
2730 will require a board or device specific function to
2735 If defined, a function that provides delays in the FPGA
2736 configuration driver.
2738 CONFIG_SYS_FPGA_CHECK_CTRLC
2739 Allow Control-C to interrupt FPGA configuration
2741 CONFIG_SYS_FPGA_CHECK_ERROR
2743 Check for configuration errors during FPGA bitfile
2744 loading. For example, abort during Virtex II
2745 configuration if the INIT_B line goes low (which
2746 indicated a CRC error).
2748 CONFIG_SYS_FPGA_WAIT_INIT
2750 Maximum time to wait for the INIT_B line to de-assert
2751 after PROB_B has been de-asserted during a Virtex II
2752 FPGA configuration sequence. The default time is 500
2755 CONFIG_SYS_FPGA_WAIT_BUSY
2757 Maximum time to wait for BUSY to de-assert during
2758 Virtex II FPGA configuration. The default is 5 ms.
2760 CONFIG_SYS_FPGA_WAIT_CONFIG
2762 Time to wait after FPGA configuration. The default is
2765 - Configuration Management:
2768 Some SoCs need special image types (e.g. U-Boot binary
2769 with a special header) as build targets. By defining
2770 CONFIG_BUILD_TARGET in the SoC / board header, this
2771 special image will be automatically built upon calling
2776 If defined, this string will be added to the U-Boot
2777 version information (U_BOOT_VERSION)
2779 - Vendor Parameter Protection:
2781 U-Boot considers the values of the environment
2782 variables "serial#" (Board Serial Number) and
2783 "ethaddr" (Ethernet Address) to be parameters that
2784 are set once by the board vendor / manufacturer, and
2785 protects these variables from casual modification by
2786 the user. Once set, these variables are read-only,
2787 and write or delete attempts are rejected. You can
2788 change this behaviour:
2790 If CONFIG_ENV_OVERWRITE is #defined in your config
2791 file, the write protection for vendor parameters is
2792 completely disabled. Anybody can change or delete
2795 Alternatively, if you define _both_ an ethaddr in the
2796 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2797 Ethernet address is installed in the environment,
2798 which can be changed exactly ONCE by the user. [The
2799 serial# is unaffected by this, i. e. it remains
2802 The same can be accomplished in a more flexible way
2803 for any variable by configuring the type of access
2804 to allow for those variables in the ".flags" variable
2805 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2810 Define this variable to enable the reservation of
2811 "protected RAM", i. e. RAM which is not overwritten
2812 by U-Boot. Define CONFIG_PRAM to hold the number of
2813 kB you want to reserve for pRAM. You can overwrite
2814 this default value by defining an environment
2815 variable "pram" to the number of kB you want to
2816 reserve. Note that the board info structure will
2817 still show the full amount of RAM. If pRAM is
2818 reserved, a new environment variable "mem" will
2819 automatically be defined to hold the amount of
2820 remaining RAM in a form that can be passed as boot
2821 argument to Linux, for instance like that:
2823 setenv bootargs ... mem=\${mem}
2826 This way you can tell Linux not to use this memory,
2827 either, which results in a memory region that will
2828 not be affected by reboots.
2830 *WARNING* If your board configuration uses automatic
2831 detection of the RAM size, you must make sure that
2832 this memory test is non-destructive. So far, the
2833 following board configurations are known to be
2836 IVMS8, IVML24, SPD8xx, TQM8xxL,
2837 HERMES, IP860, RPXlite, LWMON,
2840 - Access to physical memory region (> 4GB)
2841 Some basic support is provided for operations on memory not
2842 normally accessible to U-Boot - e.g. some architectures
2843 support access to more than 4GB of memory on 32-bit
2844 machines using physical address extension or similar.
2845 Define CONFIG_PHYSMEM to access this basic support, which
2846 currently only supports clearing the memory.
2851 Define this variable to stop the system in case of a
2852 fatal error, so that you have to reset it manually.
2853 This is probably NOT a good idea for an embedded
2854 system where you want the system to reboot
2855 automatically as fast as possible, but it may be
2856 useful during development since you can try to debug
2857 the conditions that lead to the situation.
2859 CONFIG_NET_RETRY_COUNT
2861 This variable defines the number of retries for
2862 network operations like ARP, RARP, TFTP, or BOOTP
2863 before giving up the operation. If not defined, a
2864 default value of 5 is used.
2868 Timeout waiting for an ARP reply in milliseconds.
2872 Timeout in milliseconds used in NFS protocol.
2873 If you encounter "ERROR: Cannot umount" in nfs command,
2874 try longer timeout such as
2875 #define CONFIG_NFS_TIMEOUT 10000UL
2877 - Command Interpreter:
2878 CONFIG_AUTO_COMPLETE
2880 Enable auto completion of commands using TAB.
2882 CONFIG_SYS_PROMPT_HUSH_PS2
2884 This defines the secondary prompt string, which is
2885 printed when the command interpreter needs more input
2886 to complete a command. Usually "> ".
2890 In the current implementation, the local variables
2891 space and global environment variables space are
2892 separated. Local variables are those you define by
2893 simply typing `name=value'. To access a local
2894 variable later on, you have write `$name' or
2895 `${name}'; to execute the contents of a variable
2896 directly type `$name' at the command prompt.
2898 Global environment variables are those you use
2899 setenv/printenv to work with. To run a command stored
2900 in such a variable, you need to use the run command,
2901 and you must not use the '$' sign to access them.
2903 To store commands and special characters in a
2904 variable, please use double quotation marks
2905 surrounding the whole text of the variable, instead
2906 of the backslashes before semicolons and special
2909 - Command Line Editing and History:
2910 CONFIG_CMDLINE_EDITING
2912 Enable editing and History functions for interactive
2913 command line input operations
2915 - Command Line PS1/PS2 support:
2916 CONFIG_CMDLINE_PS_SUPPORT
2918 Enable support for changing the command prompt string
2919 at run-time. Only static string is supported so far.
2920 The string is obtained from environment variables PS1
2923 - Default Environment:
2924 CONFIG_EXTRA_ENV_SETTINGS
2926 Define this to contain any number of null terminated
2927 strings (variable = value pairs) that will be part of
2928 the default environment compiled into the boot image.
2930 For example, place something like this in your
2931 board's config file:
2933 #define CONFIG_EXTRA_ENV_SETTINGS \
2937 Warning: This method is based on knowledge about the
2938 internal format how the environment is stored by the
2939 U-Boot code. This is NOT an official, exported
2940 interface! Although it is unlikely that this format
2941 will change soon, there is no guarantee either.
2942 You better know what you are doing here.
2944 Note: overly (ab)use of the default environment is
2945 discouraged. Make sure to check other ways to preset
2946 the environment like the "source" command or the
2949 CONFIG_ENV_VARS_UBOOT_CONFIG
2951 Define this in order to add variables describing the
2952 U-Boot build configuration to the default environment.
2953 These will be named arch, cpu, board, vendor, and soc.
2955 Enabling this option will cause the following to be defined:
2963 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2965 Define this in order to add variables describing certain
2966 run-time determined information about the hardware to the
2967 environment. These will be named board_name, board_rev.
2969 CONFIG_DELAY_ENVIRONMENT
2971 Normally the environment is loaded when the board is
2972 initialised so that it is available to U-Boot. This inhibits
2973 that so that the environment is not available until
2974 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2975 this is instead controlled by the value of
2976 /config/load-environment.
2978 - Parallel Flash support:
2981 Traditionally U-Boot was run on systems with parallel NOR
2982 flash. This option is used to disable support for parallel NOR
2983 flash. This option should be defined if the board does not have
2986 If this option is not defined one of the generic flash drivers
2987 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2988 selected or the board must provide an implementation of the
2989 flash API (see include/flash.h).
2991 - DataFlash Support:
2992 CONFIG_HAS_DATAFLASH
2994 Defining this option enables DataFlash features and
2995 allows to read/write in Dataflash via the standard
2998 - Serial Flash support
3001 Defining this option enables SPI flash commands
3002 'sf probe/read/write/erase/update'.
3004 Usage requires an initial 'probe' to define the serial
3005 flash parameters, followed by read/write/erase/update
3008 The following defaults may be provided by the platform
3009 to handle the common case when only a single serial
3010 flash is present on the system.
3012 CONFIG_SF_DEFAULT_BUS Bus identifier
3013 CONFIG_SF_DEFAULT_CS Chip-select
3014 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3015 CONFIG_SF_DEFAULT_SPEED in Hz
3019 Define this option to include a destructive SPI flash
3022 CONFIG_SF_DUAL_FLASH Dual flash memories
3024 Define this option to use dual flash support where two flash
3025 memories can be connected with a given cs line.
3026 Currently Xilinx Zynq qspi supports these type of connections.
3028 - SystemACE Support:
3031 Adding this option adds support for Xilinx SystemACE
3032 chips attached via some sort of local bus. The address
3033 of the chip must also be defined in the
3034 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3036 #define CONFIG_SYSTEMACE
3037 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3039 When SystemACE support is added, the "ace" device type
3040 becomes available to the fat commands, i.e. fatls.
3042 - TFTP Fixed UDP Port:
3045 If this is defined, the environment variable tftpsrcp
3046 is used to supply the TFTP UDP source port value.
3047 If tftpsrcp isn't defined, the normal pseudo-random port
3048 number generator is used.
3050 Also, the environment variable tftpdstp is used to supply
3051 the TFTP UDP destination port value. If tftpdstp isn't
3052 defined, the normal port 69 is used.
3054 The purpose for tftpsrcp is to allow a TFTP server to
3055 blindly start the TFTP transfer using the pre-configured
3056 target IP address and UDP port. This has the effect of
3057 "punching through" the (Windows XP) firewall, allowing
3058 the remainder of the TFTP transfer to proceed normally.
3059 A better solution is to properly configure the firewall,
3060 but sometimes that is not allowed.
3065 This enables a generic 'hash' command which can produce
3066 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3070 Enable the hash verify command (hash -v). This adds to code
3073 CONFIG_SHA1 - This option enables support of hashing using SHA1
3074 algorithm. The hash is calculated in software.
3075 CONFIG_SHA256 - This option enables support of hashing using
3076 SHA256 algorithm. The hash is calculated in software.
3077 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3078 for SHA1/SHA256 hashing.
3079 This affects the 'hash' command and also the
3080 hash_lookup_algo() function.
3081 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3082 hardware-acceleration for SHA1/SHA256 progressive hashing.
3083 Data can be streamed in a block at a time and the hashing
3084 is performed in hardware.
3086 Note: There is also a sha1sum command, which should perhaps
3087 be deprecated in favour of 'hash sha1'.
3089 - Freescale i.MX specific commands:
3090 CONFIG_CMD_HDMIDETECT
3091 This enables 'hdmidet' command which returns true if an
3092 HDMI monitor is detected. This command is i.MX 6 specific.
3095 This enables the 'bmode' (bootmode) command for forcing
3096 a boot from specific media.
3098 This is useful for forcing the ROM's usb downloader to
3099 activate upon a watchdog reset which is nice when iterating
3100 on U-Boot. Using the reset button or running bmode normal
3101 will set it back to normal. This command currently
3102 supports i.MX53 and i.MX6.
3104 - bootcount support:
3105 CONFIG_BOOTCOUNT_LIMIT
3107 This enables the bootcounter support, see:
3108 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3111 enable special bootcounter support on at91sam9xe based boards.
3113 enable special bootcounter support on blackfin based boards.
3115 enable special bootcounter support on da850 based boards.
3116 CONFIG_BOOTCOUNT_RAM
3117 enable support for the bootcounter in RAM
3118 CONFIG_BOOTCOUNT_I2C
3119 enable support for the bootcounter on an i2c (like RTC) device.
3120 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3121 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3123 CONFIG_BOOTCOUNT_ALEN = address len
3125 - Show boot progress:
3126 CONFIG_SHOW_BOOT_PROGRESS
3128 Defining this option allows to add some board-
3129 specific code (calling a user-provided function
3130 "show_boot_progress(int)") that enables you to show
3131 the system's boot progress on some display (for
3132 example, some LED's) on your board. At the moment,
3133 the following checkpoints are implemented:
3136 Legacy uImage format:
3139 1 common/cmd_bootm.c before attempting to boot an image
3140 -1 common/cmd_bootm.c Image header has bad magic number
3141 2 common/cmd_bootm.c Image header has correct magic number
3142 -2 common/cmd_bootm.c Image header has bad checksum
3143 3 common/cmd_bootm.c Image header has correct checksum
3144 -3 common/cmd_bootm.c Image data has bad checksum
3145 4 common/cmd_bootm.c Image data has correct checksum
3146 -4 common/cmd_bootm.c Image is for unsupported architecture
3147 5 common/cmd_bootm.c Architecture check OK
3148 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3149 6 common/cmd_bootm.c Image Type check OK
3150 -6 common/cmd_bootm.c gunzip uncompression error
3151 -7 common/cmd_bootm.c Unimplemented compression type
3152 7 common/cmd_bootm.c Uncompression OK
3153 8 common/cmd_bootm.c No uncompress/copy overwrite error
3154 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3156 9 common/image.c Start initial ramdisk verification
3157 -10 common/image.c Ramdisk header has bad magic number
3158 -11 common/image.c Ramdisk header has bad checksum
3159 10 common/image.c Ramdisk header is OK
3160 -12 common/image.c Ramdisk data has bad checksum
3161 11 common/image.c Ramdisk data has correct checksum
3162 12 common/image.c Ramdisk verification complete, start loading
3163 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3164 13 common/image.c Start multifile image verification
3165 14 common/image.c No initial ramdisk, no multifile, continue.
3167 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3169 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3170 -31 post/post.c POST test failed, detected by post_output_backlog()
3171 -32 post/post.c POST test failed, detected by post_run_single()
3173 34 common/cmd_doc.c before loading a Image from a DOC device
3174 -35 common/cmd_doc.c Bad usage of "doc" command
3175 35 common/cmd_doc.c correct usage of "doc" command
3176 -36 common/cmd_doc.c No boot device
3177 36 common/cmd_doc.c correct boot device
3178 -37 common/cmd_doc.c Unknown Chip ID on boot device
3179 37 common/cmd_doc.c correct chip ID found, device available
3180 -38 common/cmd_doc.c Read Error on boot device
3181 38 common/cmd_doc.c reading Image header from DOC device OK
3182 -39 common/cmd_doc.c Image header has bad magic number
3183 39 common/cmd_doc.c Image header has correct magic number
3184 -40 common/cmd_doc.c Error reading Image from DOC device
3185 40 common/cmd_doc.c Image header has correct magic number
3186 41 common/cmd_ide.c before loading a Image from a IDE device
3187 -42 common/cmd_ide.c Bad usage of "ide" command
3188 42 common/cmd_ide.c correct usage of "ide" command
3189 -43 common/cmd_ide.c No boot device
3190 43 common/cmd_ide.c boot device found
3191 -44 common/cmd_ide.c Device not available
3192 44 common/cmd_ide.c Device available
3193 -45 common/cmd_ide.c wrong partition selected
3194 45 common/cmd_ide.c partition selected
3195 -46 common/cmd_ide.c Unknown partition table
3196 46 common/cmd_ide.c valid partition table found
3197 -47 common/cmd_ide.c Invalid partition type
3198 47 common/cmd_ide.c correct partition type
3199 -48 common/cmd_ide.c Error reading Image Header on boot device
3200 48 common/cmd_ide.c reading Image Header from IDE device OK
3201 -49 common/cmd_ide.c Image header has bad magic number
3202 49 common/cmd_ide.c Image header has correct magic number
3203 -50 common/cmd_ide.c Image header has bad checksum
3204 50 common/cmd_ide.c Image header has correct checksum
3205 -51 common/cmd_ide.c Error reading Image from IDE device
3206 51 common/cmd_ide.c reading Image from IDE device OK
3207 52 common/cmd_nand.c before loading a Image from a NAND device
3208 -53 common/cmd_nand.c Bad usage of "nand" command
3209 53 common/cmd_nand.c correct usage of "nand" command
3210 -54 common/cmd_nand.c No boot device
3211 54 common/cmd_nand.c boot device found
3212 -55 common/cmd_nand.c Unknown Chip ID on boot device
3213 55 common/cmd_nand.c correct chip ID found, device available
3214 -56 common/cmd_nand.c Error reading Image Header on boot device
3215 56 common/cmd_nand.c reading Image Header from NAND device OK
3216 -57 common/cmd_nand.c Image header has bad magic number
3217 57 common/cmd_nand.c Image header has correct magic number
3218 -58 common/cmd_nand.c Error reading Image from NAND device
3219 58 common/cmd_nand.c reading Image from NAND device OK
3221 -60 common/env_common.c Environment has a bad CRC, using default
3223 64 net/eth.c starting with Ethernet configuration.
3224 -64 net/eth.c no Ethernet found.
3225 65 net/eth.c Ethernet found.
3227 -80 common/cmd_net.c usage wrong
3228 80 common/cmd_net.c before calling net_loop()
3229 -81 common/cmd_net.c some error in net_loop() occurred
3230 81 common/cmd_net.c net_loop() back without error
3231 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3232 82 common/cmd_net.c trying automatic boot
3233 83 common/cmd_net.c running "source" command
3234 -83 common/cmd_net.c some error in automatic boot or "source" command
3235 84 common/cmd_net.c end without errors
3240 100 common/cmd_bootm.c Kernel FIT Image has correct format
3241 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3242 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3243 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3244 102 common/cmd_bootm.c Kernel unit name specified
3245 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3246 103 common/cmd_bootm.c Found configuration node
3247 104 common/cmd_bootm.c Got kernel subimage node offset
3248 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3249 105 common/cmd_bootm.c Kernel subimage hash verification OK
3250 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3251 106 common/cmd_bootm.c Architecture check OK
3252 -106 common/cmd_bootm.c Kernel subimage has wrong type
3253 107 common/cmd_bootm.c Kernel subimage type OK
3254 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3255 108 common/cmd_bootm.c Got kernel subimage data/size
3256 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3257 -109 common/cmd_bootm.c Can't get kernel subimage type
3258 -110 common/cmd_bootm.c Can't get kernel subimage comp
3259 -111 common/cmd_bootm.c Can't get kernel subimage os
3260 -112 common/cmd_bootm.c Can't get kernel subimage load address
3261 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3263 120 common/image.c Start initial ramdisk verification
3264 -120 common/image.c Ramdisk FIT image has incorrect format
3265 121 common/image.c Ramdisk FIT image has correct format
3266 122 common/image.c No ramdisk subimage unit name, using configuration
3267 -122 common/image.c Can't get configuration for ramdisk subimage
3268 123 common/image.c Ramdisk unit name specified
3269 -124 common/image.c Can't get ramdisk subimage node offset
3270 125 common/image.c Got ramdisk subimage node offset
3271 -125 common/image.c Ramdisk subimage hash verification failed
3272 126 common/image.c Ramdisk subimage hash verification OK
3273 -126 common/image.c Ramdisk subimage for unsupported architecture
3274 127 common/image.c Architecture check OK
3275 -127 common/image.c Can't get ramdisk subimage data/size
3276 128 common/image.c Got ramdisk subimage data/size
3277 129 common/image.c Can't get ramdisk load address
3278 -129 common/image.c Got ramdisk load address
3280 -130 common/cmd_doc.c Incorrect FIT image format
3281 131 common/cmd_doc.c FIT image format OK
3283 -140 common/cmd_ide.c Incorrect FIT image format
3284 141 common/cmd_ide.c FIT image format OK
3286 -150 common/cmd_nand.c Incorrect FIT image format
3287 151 common/cmd_nand.c FIT image format OK
3289 - legacy image format:
3290 CONFIG_IMAGE_FORMAT_LEGACY
3291 enables the legacy image format support in U-Boot.
3294 enabled if CONFIG_FIT_SIGNATURE is not defined.
3296 CONFIG_DISABLE_IMAGE_LEGACY
3297 disable the legacy image format
3299 This define is introduced, as the legacy image format is
3300 enabled per default for backward compatibility.
3302 - FIT image support:
3303 CONFIG_FIT_DISABLE_SHA256
3304 Supporting SHA256 hashes has quite an impact on binary size.
3305 For constrained systems sha256 hash support can be disabled
3308 TODO(sjg@chromium.org): Adjust this option to be positive,
3309 and move it to Kconfig
3311 - Standalone program support:
3312 CONFIG_STANDALONE_LOAD_ADDR
3314 This option defines a board specific value for the
3315 address where standalone program gets loaded, thus
3316 overwriting the architecture dependent default
3319 - Frame Buffer Address:
3322 Define CONFIG_FB_ADDR if you want to use specific
3323 address for frame buffer. This is typically the case
3324 when using a graphics controller has separate video
3325 memory. U-Boot will then place the frame buffer at
3326 the given address instead of dynamically reserving it
3327 in system RAM by calling lcd_setmem(), which grabs
3328 the memory for the frame buffer depending on the
3329 configured panel size.
3331 Please see board_init_f function.
3333 - Automatic software updates via TFTP server
3335 CONFIG_UPDATE_TFTP_CNT_MAX
3336 CONFIG_UPDATE_TFTP_MSEC_MAX
3338 These options enable and control the auto-update feature;
3339 for a more detailed description refer to doc/README.update.
3341 - MTD Support (mtdparts command, UBI support)
3344 Adds the MTD device infrastructure from the Linux kernel.
3345 Needed for mtdparts command support.
3347 CONFIG_MTD_PARTITIONS
3349 Adds the MTD partitioning infrastructure from the Linux
3350 kernel. Needed for UBI support.
3355 Adds commands for interacting with MTD partitions formatted
3356 with the UBI flash translation layer
3358 Requires also defining CONFIG_RBTREE
3360 CONFIG_UBI_SILENCE_MSG
3362 Make the verbose messages from UBI stop printing. This leaves
3363 warnings and errors enabled.
3366 CONFIG_MTD_UBI_WL_THRESHOLD
3367 This parameter defines the maximum difference between the highest
3368 erase counter value and the lowest erase counter value of eraseblocks
3369 of UBI devices. When this threshold is exceeded, UBI starts performing
3370 wear leveling by means of moving data from eraseblock with low erase
3371 counter to eraseblocks with high erase counter.
3373 The default value should be OK for SLC NAND flashes, NOR flashes and
3374 other flashes which have eraseblock life-cycle 100000 or more.
3375 However, in case of MLC NAND flashes which typically have eraseblock
3376 life-cycle less than 10000, the threshold should be lessened (e.g.,
3377 to 128 or 256, although it does not have to be power of 2).
3381 CONFIG_MTD_UBI_BEB_LIMIT
3382 This option specifies the maximum bad physical eraseblocks UBI
3383 expects on the MTD device (per 1024 eraseblocks). If the
3384 underlying flash does not admit of bad eraseblocks (e.g. NOR
3385 flash), this value is ignored.
3387 NAND datasheets often specify the minimum and maximum NVM
3388 (Number of Valid Blocks) for the flashes' endurance lifetime.
3389 The maximum expected bad eraseblocks per 1024 eraseblocks
3390 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3391 which gives 20 for most NANDs (MaxNVB is basically the total
3392 count of eraseblocks on the chip).
3394 To put it differently, if this value is 20, UBI will try to
3395 reserve about 1.9% of physical eraseblocks for bad blocks
3396 handling. And that will be 1.9% of eraseblocks on the entire
3397 NAND chip, not just the MTD partition UBI attaches. This means
3398 that if you have, say, a NAND flash chip admits maximum 40 bad
3399 eraseblocks, and it is split on two MTD partitions of the same
3400 size, UBI will reserve 40 eraseblocks when attaching a
3405 CONFIG_MTD_UBI_FASTMAP
3406 Fastmap is a mechanism which allows attaching an UBI device
3407 in nearly constant time. Instead of scanning the whole MTD device it
3408 only has to locate a checkpoint (called fastmap) on the device.
3409 The on-flash fastmap contains all information needed to attach
3410 the device. Using fastmap makes only sense on large devices where
3411 attaching by scanning takes long. UBI will not automatically install
3412 a fastmap on old images, but you can set the UBI parameter
3413 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3414 that fastmap-enabled images are still usable with UBI implementations
3415 without fastmap support. On typical flash devices the whole fastmap
3416 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3418 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3419 Set this parameter to enable fastmap automatically on images
3423 CONFIG_MTD_UBI_FM_DEBUG
3424 Enable UBI fastmap debug
3430 Adds commands for interacting with UBI volumes formatted as
3431 UBIFS. UBIFS is read-only in u-boot.
3433 Requires UBI support as well as CONFIG_LZO
3435 CONFIG_UBIFS_SILENCE_MSG
3437 Make the verbose messages from UBIFS stop printing. This leaves
3438 warnings and errors enabled.
3442 Enable building of SPL globally.
3445 LDSCRIPT for linking the SPL binary.
3447 CONFIG_SPL_MAX_FOOTPRINT
3448 Maximum size in memory allocated to the SPL, BSS included.
3449 When defined, the linker checks that the actual memory
3450 used by SPL from _start to __bss_end does not exceed it.
3451 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3452 must not be both defined at the same time.
3455 Maximum size of the SPL image (text, data, rodata, and
3456 linker lists sections), BSS excluded.
3457 When defined, the linker checks that the actual size does
3460 CONFIG_SPL_TEXT_BASE
3461 TEXT_BASE for linking the SPL binary.
3463 CONFIG_SPL_RELOC_TEXT_BASE
3464 Address to relocate to. If unspecified, this is equal to
3465 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3467 CONFIG_SPL_BSS_START_ADDR
3468 Link address for the BSS within the SPL binary.
3470 CONFIG_SPL_BSS_MAX_SIZE
3471 Maximum size in memory allocated to the SPL BSS.
3472 When defined, the linker checks that the actual memory used
3473 by SPL from __bss_start to __bss_end does not exceed it.
3474 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3475 must not be both defined at the same time.
3478 Adress of the start of the stack SPL will use
3480 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3481 When defined, SPL will panic() if the image it has
3482 loaded does not have a signature.
3483 Defining this is useful when code which loads images
3484 in SPL cannot guarantee that absolutely all read errors
3486 An example is the LPC32XX MLC NAND driver, which will
3487 consider that a completely unreadable NAND block is bad,
3488 and thus should be skipped silently.
3490 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3491 When defined, SPL will proceed to another boot method
3492 if the image it has loaded does not have a signature.
3494 CONFIG_SPL_RELOC_STACK
3495 Adress of the start of the stack SPL will use after
3496 relocation. If unspecified, this is equal to
3499 CONFIG_SYS_SPL_MALLOC_START
3500 Starting address of the malloc pool used in SPL.
3501 When this option is set the full malloc is used in SPL and
3502 it is set up by spl_init() and before that, the simple malloc()
3503 can be used if CONFIG_SYS_MALLOC_F is defined.
3505 CONFIG_SYS_SPL_MALLOC_SIZE
3506 The size of the malloc pool used in SPL.
3508 CONFIG_SPL_FRAMEWORK
3509 Enable the SPL framework under common/. This framework
3510 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3511 NAND loading of the Linux Kernel.
3514 Enable booting directly to an OS from SPL.
3515 See also: doc/README.falcon
3517 CONFIG_SPL_DISPLAY_PRINT
3518 For ARM, enable an optional function to print more information
3519 about the running system.
3521 CONFIG_SPL_INIT_MINIMAL
3522 Arch init code should be built for a very small image
3524 CONFIG_SPL_LIBCOMMON_SUPPORT
3525 Support for common/libcommon.o in SPL binary
3527 CONFIG_SPL_LIBDISK_SUPPORT
3528 Support for disk/libdisk.o in SPL binary
3530 CONFIG_SPL_I2C_SUPPORT
3531 Support for drivers/i2c/libi2c.o in SPL binary
3533 CONFIG_SPL_GPIO_SUPPORT
3534 Support for drivers/gpio/libgpio.o in SPL binary
3536 CONFIG_SPL_MMC_SUPPORT
3537 Support for drivers/mmc/libmmc.o in SPL binary
3539 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3540 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3541 Address and partition on the MMC to load U-Boot from
3542 when the MMC is being used in raw mode.
3544 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3545 Partition on the MMC to load U-Boot from when the MMC is being
3548 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3549 Sector to load kernel uImage from when MMC is being
3550 used in raw mode (for Falcon mode)
3552 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3553 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3554 Sector and number of sectors to load kernel argument
3555 parameters from when MMC is being used in raw mode
3558 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3559 Partition on the MMC to load U-Boot from when the MMC is being
3562 CONFIG_SPL_FAT_SUPPORT
3563 Support for fs/fat/libfat.o in SPL binary
3565 CONFIG_SPL_EXT_SUPPORT
3566 Support for EXT filesystem in SPL binary
3568 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3569 Filename to read to load U-Boot when reading from filesystem
3571 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3572 Filename to read to load kernel uImage when reading
3573 from filesystem (for Falcon mode)
3575 CONFIG_SPL_FS_LOAD_ARGS_NAME
3576 Filename to read to load kernel argument parameters
3577 when reading from filesystem (for Falcon mode)
3579 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3580 Set this for NAND SPL on PPC mpc83xx targets, so that
3581 start.S waits for the rest of the SPL to load before
3582 continuing (the hardware starts execution after just
3583 loading the first page rather than the full 4K).
3585 CONFIG_SPL_SKIP_RELOCATE
3586 Avoid SPL relocation
3588 CONFIG_SPL_NAND_BASE
3589 Include nand_base.c in the SPL. Requires
3590 CONFIG_SPL_NAND_DRIVERS.
3592 CONFIG_SPL_NAND_DRIVERS
3593 SPL uses normal NAND drivers, not minimal drivers.
3596 Include standard software ECC in the SPL
3598 CONFIG_SPL_NAND_SIMPLE
3599 Support for NAND boot using simple NAND drivers that
3600 expose the cmd_ctrl() interface.
3602 CONFIG_SPL_MTD_SUPPORT
3603 Support for the MTD subsystem within SPL. Useful for
3604 environment on NAND support within SPL.
3606 CONFIG_SPL_NAND_RAW_ONLY
3607 Support to boot only raw u-boot.bin images. Use this only
3608 if you need to save space.
3610 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3611 Set for the SPL on PPC mpc8xxx targets, support for
3612 drivers/ddr/fsl/libddr.o in SPL binary.
3614 CONFIG_SPL_COMMON_INIT_DDR
3615 Set for common ddr init with serial presence detect in
3618 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3619 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3620 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3621 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3622 CONFIG_SYS_NAND_ECCBYTES
3623 Defines the size and behavior of the NAND that SPL uses
3626 CONFIG_SPL_NAND_BOOT
3627 Add support NAND boot
3629 CONFIG_SYS_NAND_U_BOOT_OFFS
3630 Location in NAND to read U-Boot from
3632 CONFIG_SYS_NAND_U_BOOT_DST
3633 Location in memory to load U-Boot to
3635 CONFIG_SYS_NAND_U_BOOT_SIZE
3636 Size of image to load
3638 CONFIG_SYS_NAND_U_BOOT_START
3639 Entry point in loaded image to jump to
3641 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3642 Define this if you need to first read the OOB and then the
3643 data. This is used, for example, on davinci platforms.
3645 CONFIG_SPL_OMAP3_ID_NAND
3646 Support for an OMAP3-specific set of functions to return the
3647 ID and MFR of the first attached NAND chip, if present.
3649 CONFIG_SPL_SERIAL_SUPPORT
3650 Support for drivers/serial/libserial.o in SPL binary
3652 CONFIG_SPL_SPI_FLASH_SUPPORT
3653 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3655 CONFIG_SPL_SPI_SUPPORT
3656 Support for drivers/spi/libspi.o in SPL binary
3658 CONFIG_SPL_RAM_DEVICE
3659 Support for running image already present in ram, in SPL binary
3661 CONFIG_SPL_LIBGENERIC_SUPPORT
3662 Support for lib/libgeneric.o in SPL binary
3664 CONFIG_SPL_ENV_SUPPORT
3665 Support for the environment operating in SPL binary
3667 CONFIG_SPL_NET_SUPPORT
3668 Support for the net/libnet.o in SPL binary.
3669 It conflicts with SPL env from storage medium specified by
3670 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3673 Image offset to which the SPL should be padded before appending
3674 the SPL payload. By default, this is defined as
3675 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3676 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3677 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3680 Final target image containing SPL and payload. Some SPLs
3681 use an arch-specific makefile fragment instead, for
3682 example if more than one image needs to be produced.
3684 CONFIG_FIT_SPL_PRINT
3685 Printing information about a FIT image adds quite a bit of
3686 code to SPL. So this is normally disabled in SPL. Use this
3687 option to re-enable it. This will affect the output of the
3688 bootm command when booting a FIT image.
3692 Enable building of TPL globally.
3695 Image offset to which the TPL should be padded before appending
3696 the TPL payload. By default, this is defined as
3697 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3698 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3699 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3701 - Interrupt support (PPC):
3703 There are common interrupt_init() and timer_interrupt()
3704 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3705 for CPU specific initialization. interrupt_init_cpu()
3706 should set decrementer_count to appropriate value. If
3707 CPU resets decrementer automatically after interrupt
3708 (ppc4xx) it should set decrementer_count to zero.
3709 timer_interrupt() calls timer_interrupt_cpu() for CPU
3710 specific handling. If board has watchdog / status_led
3711 / other_activity_monitor it works automatically from
3712 general timer_interrupt().
3715 Board initialization settings:
3716 ------------------------------
3718 During Initialization u-boot calls a number of board specific functions
3719 to allow the preparation of board specific prerequisites, e.g. pin setup
3720 before drivers are initialized. To enable these callbacks the
3721 following configuration macros have to be defined. Currently this is
3722 architecture specific, so please check arch/your_architecture/lib/board.c
3723 typically in board_init_f() and board_init_r().
3725 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3726 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3727 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3728 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3730 Configuration Settings:
3731 -----------------------
3733 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3734 Optionally it can be defined to support 64-bit memory commands.
3736 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3737 undefine this when you're short of memory.
3739 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3740 width of the commands listed in the 'help' command output.
3742 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3743 prompt for user input.
3745 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3747 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3749 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3751 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3752 the application (usually a Linux kernel) when it is
3755 - CONFIG_SYS_BAUDRATE_TABLE:
3756 List of legal baudrate settings for this board.
3758 - CONFIG_SYS_CONSOLE_INFO_QUIET
3759 Suppress display of console information at boot.
3761 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3762 If the board specific function
3763 extern int overwrite_console (void);
3764 returns 1, the stdin, stderr and stdout are switched to the
3765 serial port, else the settings in the environment are used.
3767 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3768 Enable the call to overwrite_console().
3770 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3771 Enable overwrite of previous console environment settings.
3773 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3774 Begin and End addresses of the area used by the
3777 - CONFIG_SYS_ALT_MEMTEST:
3778 Enable an alternate, more extensive memory test.
3780 - CONFIG_SYS_MEMTEST_SCRATCH:
3781 Scratch address used by the alternate memory test
3782 You only need to set this if address zero isn't writeable
3784 - CONFIG_SYS_MEM_RESERVE_SECURE
3785 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3786 is substracted from total RAM and won't be reported to OS.
3787 This memory can be used as secure memory. A variable
3788 gd->secure_ram is used to track the location. In systems
3789 the RAM base is not zero, or RAM is divided into banks,
3790 this variable needs to be recalcuated to get the address.
3792 - CONFIG_SYS_MEM_TOP_HIDE:
3793 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3794 this specified memory area will get subtracted from the top
3795 (end) of RAM and won't get "touched" at all by U-Boot. By
3796 fixing up gd->ram_size the Linux kernel should gets passed
3797 the now "corrected" memory size and won't touch it either.
3798 This should work for arch/ppc and arch/powerpc. Only Linux
3799 board ports in arch/powerpc with bootwrapper support that
3800 recalculate the memory size from the SDRAM controller setup
3801 will have to get fixed in Linux additionally.
3803 This option can be used as a workaround for the 440EPx/GRx
3804 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3807 WARNING: Please make sure that this value is a multiple of
3808 the Linux page size (normally 4k). If this is not the case,
3809 then the end address of the Linux memory will be located at a
3810 non page size aligned address and this could cause major
3813 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3814 Enable temporary baudrate change while serial download
3816 - CONFIG_SYS_SDRAM_BASE:
3817 Physical start address of SDRAM. _Must_ be 0 here.
3819 - CONFIG_SYS_MBIO_BASE:
3820 Physical start address of Motherboard I/O (if using a
3823 - CONFIG_SYS_FLASH_BASE:
3824 Physical start address of Flash memory.
3826 - CONFIG_SYS_MONITOR_BASE:
3827 Physical start address of boot monitor code (set by
3828 make config files to be same as the text base address
3829 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3830 CONFIG_SYS_FLASH_BASE when booting from flash.
3832 - CONFIG_SYS_MONITOR_LEN:
3833 Size of memory reserved for monitor code, used to
3834 determine _at_compile_time_ (!) if the environment is
3835 embedded within the U-Boot image, or in a separate
3838 - CONFIG_SYS_MALLOC_LEN:
3839 Size of DRAM reserved for malloc() use.
3841 - CONFIG_SYS_MALLOC_F_LEN
3842 Size of the malloc() pool for use before relocation. If
3843 this is defined, then a very simple malloc() implementation
3844 will become available before relocation. The address is just
3845 below the global data, and the stack is moved down to make
3848 This feature allocates regions with increasing addresses
3849 within the region. calloc() is supported, but realloc()
3850 is not available. free() is supported but does nothing.
3851 The memory will be freed (or in fact just forgotten) when
3852 U-Boot relocates itself.
3854 Pre-relocation malloc() is only supported on ARM and sandbox
3855 at present but is fairly easy to enable for other archs.
3857 - CONFIG_SYS_MALLOC_SIMPLE
3858 Provides a simple and small malloc() and calloc() for those
3859 boards which do not use the full malloc in SPL (which is
3860 enabled with CONFIG_SYS_SPL_MALLOC_START).
3862 - CONFIG_SYS_NONCACHED_MEMORY:
3863 Size of non-cached memory area. This area of memory will be
3864 typically located right below the malloc() area and mapped
3865 uncached in the MMU. This is useful for drivers that would
3866 otherwise require a lot of explicit cache maintenance. For
3867 some drivers it's also impossible to properly maintain the
3868 cache. For example if the regions that need to be flushed
3869 are not a multiple of the cache-line size, *and* padding
3870 cannot be allocated between the regions to align them (i.e.
3871 if the HW requires a contiguous array of regions, and the
3872 size of each region is not cache-aligned), then a flush of
3873 one region may result in overwriting data that hardware has
3874 written to another region in the same cache-line. This can
3875 happen for example in network drivers where descriptors for
3876 buffers are typically smaller than the CPU cache-line (e.g.
3877 16 bytes vs. 32 or 64 bytes).
3879 Non-cached memory is only supported on 32-bit ARM at present.
3881 - CONFIG_SYS_BOOTM_LEN:
3882 Normally compressed uImages are limited to an
3883 uncompressed size of 8 MBytes. If this is not enough,
3884 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3885 to adjust this setting to your needs.
3887 - CONFIG_SYS_BOOTMAPSZ:
3888 Maximum size of memory mapped by the startup code of
3889 the Linux kernel; all data that must be processed by
3890 the Linux kernel (bd_info, boot arguments, FDT blob if
3891 used) must be put below this limit, unless "bootm_low"
3892 environment variable is defined and non-zero. In such case
3893 all data for the Linux kernel must be between "bootm_low"
3894 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3895 variable "bootm_mapsize" will override the value of
3896 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3897 then the value in "bootm_size" will be used instead.
3899 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3900 Enable initrd_high functionality. If defined then the
3901 initrd_high feature is enabled and the bootm ramdisk subcommand
3904 - CONFIG_SYS_BOOT_GET_CMDLINE:
3905 Enables allocating and saving kernel cmdline in space between
3906 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3908 - CONFIG_SYS_BOOT_GET_KBD:
3909 Enables allocating and saving a kernel copy of the bd_info in
3910 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3912 - CONFIG_SYS_MAX_FLASH_BANKS:
3913 Max number of Flash memory banks
3915 - CONFIG_SYS_MAX_FLASH_SECT:
3916 Max number of sectors on a Flash chip
3918 - CONFIG_SYS_FLASH_ERASE_TOUT:
3919 Timeout for Flash erase operations (in ms)
3921 - CONFIG_SYS_FLASH_WRITE_TOUT:
3922 Timeout for Flash write operations (in ms)
3924 - CONFIG_SYS_FLASH_LOCK_TOUT
3925 Timeout for Flash set sector lock bit operation (in ms)
3927 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3928 Timeout for Flash clear lock bits operation (in ms)
3930 - CONFIG_SYS_FLASH_PROTECTION
3931 If defined, hardware flash sectors protection is used
3932 instead of U-Boot software protection.
3934 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3936 Enable TFTP transfers directly to flash memory;
3937 without this option such a download has to be
3938 performed in two steps: (1) download to RAM, and (2)
3939 copy from RAM to flash.
3941 The two-step approach is usually more reliable, since
3942 you can check if the download worked before you erase
3943 the flash, but in some situations (when system RAM is
3944 too limited to allow for a temporary copy of the
3945 downloaded image) this option may be very useful.
3947 - CONFIG_SYS_FLASH_CFI:
3948 Define if the flash driver uses extra elements in the
3949 common flash structure for storing flash geometry.
3951 - CONFIG_FLASH_CFI_DRIVER
3952 This option also enables the building of the cfi_flash driver
3953 in the drivers directory
3955 - CONFIG_FLASH_CFI_MTD
3956 This option enables the building of the cfi_mtd driver
3957 in the drivers directory. The driver exports CFI flash
3960 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3961 Use buffered writes to flash.
3963 - CONFIG_FLASH_SPANSION_S29WS_N
3964 s29ws-n MirrorBit flash has non-standard addresses for buffered
3967 - CONFIG_SYS_FLASH_QUIET_TEST
3968 If this option is defined, the common CFI flash doesn't
3969 print it's warning upon not recognized FLASH banks. This
3970 is useful, if some of the configured banks are only
3971 optionally available.
3973 - CONFIG_FLASH_SHOW_PROGRESS
3974 If defined (must be an integer), print out countdown
3975 digits and dots. Recommended value: 45 (9..1) for 80
3976 column displays, 15 (3..1) for 40 column displays.
3978 - CONFIG_FLASH_VERIFY
3979 If defined, the content of the flash (destination) is compared
3980 against the source after the write operation. An error message
3981 will be printed when the contents are not identical.
3982 Please note that this option is useless in nearly all cases,
3983 since such flash programming errors usually are detected earlier
3984 while unprotecting/erasing/programming. Please only enable
3985 this option if you really know what you are doing.
3987 - CONFIG_SYS_RX_ETH_BUFFER:
3988 Defines the number of Ethernet receive buffers. On some
3989 Ethernet controllers it is recommended to set this value
3990 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3991 buffers can be full shortly after enabling the interface
3992 on high Ethernet traffic.
3993 Defaults to 4 if not defined.
3995 - CONFIG_ENV_MAX_ENTRIES
3997 Maximum number of entries in the hash table that is used
3998 internally to store the environment settings. The default
3999 setting is supposed to be generous and should work in most
4000 cases. This setting can be used to tune behaviour; see
4001 lib/hashtable.c for details.
4003 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4004 - CONFIG_ENV_FLAGS_LIST_STATIC
4005 Enable validation of the values given to environment variables when
4006 calling env set. Variables can be restricted to only decimal,
4007 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4008 the variables can also be restricted to IP address or MAC address.
4010 The format of the list is:
4011 type_attribute = [s|d|x|b|i|m]
4012 access_attribute = [a|r|o|c]
4013 attributes = type_attribute[access_attribute]
4014 entry = variable_name[:attributes]
4017 The type attributes are:
4018 s - String (default)
4021 b - Boolean ([1yYtT|0nNfF])
4025 The access attributes are:
4031 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4032 Define this to a list (string) to define the ".flags"
4033 environment variable in the default or embedded environment.
4035 - CONFIG_ENV_FLAGS_LIST_STATIC
4036 Define this to a list (string) to define validation that
4037 should be done if an entry is not found in the ".flags"
4038 environment variable. To override a setting in the static
4039 list, simply add an entry for the same variable name to the
4042 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4043 regular expression. This allows multiple variables to define the same
4044 flags without explicitly listing them for each variable.
4046 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4047 If defined, don't allow the -f switch to env set override variable
4050 - CONFIG_SYS_GENERIC_BOARD
4051 This selects the architecture-generic board system instead of the
4052 architecture-specific board files. It is intended to move boards
4053 to this new framework over time. Defining this will disable the
4054 arch/foo/lib/board.c file and use common/board_f.c and
4055 common/board_r.c instead. To use this option your architecture
4056 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4057 If you find problems enabling this option on your board please report
4058 the problem and send patches!
4060 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4061 This is set by OMAP boards for the max time that reset should
4062 be asserted. See doc/README.omap-reset-time for details on how
4063 the value can be calculated on a given board.
4066 If stdint.h is available with your toolchain you can define this
4067 option to enable it. You can provide option 'USE_STDINT=1' when
4068 building U-Boot to enable this.
4070 The following definitions that deal with the placement and management
4071 of environment data (variable area); in general, we support the
4072 following configurations:
4074 - CONFIG_BUILD_ENVCRC:
4076 Builds up envcrc with the target environment so that external utils
4077 may easily extract it and embed it in final U-Boot images.
4079 - CONFIG_ENV_IS_IN_FLASH:
4081 Define this if the environment is in flash memory.
4083 a) The environment occupies one whole flash sector, which is
4084 "embedded" in the text segment with the U-Boot code. This
4085 happens usually with "bottom boot sector" or "top boot
4086 sector" type flash chips, which have several smaller
4087 sectors at the start or the end. For instance, such a
4088 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4089 such a case you would place the environment in one of the
4090 4 kB sectors - with U-Boot code before and after it. With
4091 "top boot sector" type flash chips, you would put the
4092 environment in one of the last sectors, leaving a gap
4093 between U-Boot and the environment.
4095 - CONFIG_ENV_OFFSET:
4097 Offset of environment data (variable area) to the
4098 beginning of flash memory; for instance, with bottom boot
4099 type flash chips the second sector can be used: the offset
4100 for this sector is given here.
4102 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4106 This is just another way to specify the start address of
4107 the flash sector containing the environment (instead of
4110 - CONFIG_ENV_SECT_SIZE:
4112 Size of the sector containing the environment.
4115 b) Sometimes flash chips have few, equal sized, BIG sectors.
4116 In such a case you don't want to spend a whole sector for
4121 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4122 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4123 of this flash sector for the environment. This saves
4124 memory for the RAM copy of the environment.
4126 It may also save flash memory if you decide to use this
4127 when your environment is "embedded" within U-Boot code,
4128 since then the remainder of the flash sector could be used
4129 for U-Boot code. It should be pointed out that this is
4130 STRONGLY DISCOURAGED from a robustness point of view:
4131 updating the environment in flash makes it always
4132 necessary to erase the WHOLE sector. If something goes
4133 wrong before the contents has been restored from a copy in
4134 RAM, your target system will be dead.
4136 - CONFIG_ENV_ADDR_REDUND
4137 CONFIG_ENV_SIZE_REDUND
4139 These settings describe a second storage area used to hold
4140 a redundant copy of the environment data, so that there is
4141 a valid backup copy in case there is a power failure during
4142 a "saveenv" operation.
4144 BE CAREFUL! Any changes to the flash layout, and some changes to the
4145 source code will make it necessary to adapt <board>/u-boot.lds*
4149 - CONFIG_ENV_IS_IN_NVRAM:
4151 Define this if you have some non-volatile memory device
4152 (NVRAM, battery buffered SRAM) which you want to use for the
4158 These two #defines are used to determine the memory area you
4159 want to use for environment. It is assumed that this memory
4160 can just be read and written to, without any special
4163 BE CAREFUL! The first access to the environment happens quite early
4164 in U-Boot initialization (when we try to get the setting of for the
4165 console baudrate). You *MUST* have mapped your NVRAM area then, or
4168 Please note that even with NVRAM we still use a copy of the
4169 environment in RAM: we could work on NVRAM directly, but we want to
4170 keep settings there always unmodified except somebody uses "saveenv"
4171 to save the current settings.
4174 - CONFIG_ENV_IS_IN_EEPROM:
4176 Use this if you have an EEPROM or similar serial access
4177 device and a driver for it.
4179 - CONFIG_ENV_OFFSET:
4182 These two #defines specify the offset and size of the
4183 environment area within the total memory of your EEPROM.
4185 - CONFIG_SYS_I2C_EEPROM_ADDR:
4186 If defined, specified the chip address of the EEPROM device.
4187 The default address is zero.
4189 - CONFIG_SYS_I2C_EEPROM_BUS:
4190 If defined, specified the i2c bus of the EEPROM device.
4192 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4193 If defined, the number of bits used to address bytes in a
4194 single page in the EEPROM device. A 64 byte page, for example
4195 would require six bits.
4197 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4198 If defined, the number of milliseconds to delay between
4199 page writes. The default is zero milliseconds.
4201 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4202 The length in bytes of the EEPROM memory array address. Note
4203 that this is NOT the chip address length!
4205 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4206 EEPROM chips that implement "address overflow" are ones
4207 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4208 address and the extra bits end up in the "chip address" bit
4209 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4212 Note that we consider the length of the address field to
4213 still be one byte because the extra address bits are hidden
4214 in the chip address.
4216 - CONFIG_SYS_EEPROM_SIZE:
4217 The size in bytes of the EEPROM device.
4219 - CONFIG_ENV_EEPROM_IS_ON_I2C
4220 define this, if you have I2C and SPI activated, and your
4221 EEPROM, which holds the environment, is on the I2C bus.
4223 - CONFIG_I2C_ENV_EEPROM_BUS
4224 if you have an Environment on an EEPROM reached over
4225 I2C muxes, you can define here, how to reach this
4226 EEPROM. For example:
4228 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4230 EEPROM which holds the environment, is reached over
4231 a pca9547 i2c mux with address 0x70, channel 3.
4233 - CONFIG_ENV_IS_IN_DATAFLASH:
4235 Define this if you have a DataFlash memory device which you
4236 want to use for the environment.
4238 - CONFIG_ENV_OFFSET:
4242 These three #defines specify the offset and size of the
4243 environment area within the total memory of your DataFlash placed
4244 at the specified address.
4246 - CONFIG_ENV_IS_IN_SPI_FLASH:
4248 Define this if you have a SPI Flash memory device which you
4249 want to use for the environment.
4251 - CONFIG_ENV_OFFSET:
4254 These two #defines specify the offset and size of the
4255 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4256 aligned to an erase sector boundary.
4258 - CONFIG_ENV_SECT_SIZE:
4260 Define the SPI flash's sector size.
4262 - CONFIG_ENV_OFFSET_REDUND (optional):
4264 This setting describes a second storage area of CONFIG_ENV_SIZE
4265 size used to hold a redundant copy of the environment data, so
4266 that there is a valid backup copy in case there is a power failure
4267 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4268 aligned to an erase sector boundary.
4270 - CONFIG_ENV_SPI_BUS (optional):
4271 - CONFIG_ENV_SPI_CS (optional):
4273 Define the SPI bus and chip select. If not defined they will be 0.
4275 - CONFIG_ENV_SPI_MAX_HZ (optional):
4277 Define the SPI max work clock. If not defined then use 1MHz.
4279 - CONFIG_ENV_SPI_MODE (optional):
4281 Define the SPI work mode. If not defined then use SPI_MODE_3.
4283 - CONFIG_ENV_IS_IN_REMOTE:
4285 Define this if you have a remote memory space which you
4286 want to use for the local device's environment.
4291 These two #defines specify the address and size of the
4292 environment area within the remote memory space. The
4293 local device can get the environment from remote memory
4294 space by SRIO or PCIE links.
4296 BE CAREFUL! For some special cases, the local device can not use
4297 "saveenv" command. For example, the local device will get the
4298 environment stored in a remote NOR flash by SRIO or PCIE link,
4299 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4301 - CONFIG_ENV_IS_IN_NAND:
4303 Define this if you have a NAND device which you want to use
4304 for the environment.
4306 - CONFIG_ENV_OFFSET:
4309 These two #defines specify the offset and size of the environment
4310 area within the first NAND device. CONFIG_ENV_OFFSET must be
4311 aligned to an erase block boundary.
4313 - CONFIG_ENV_OFFSET_REDUND (optional):
4315 This setting describes a second storage area of CONFIG_ENV_SIZE
4316 size used to hold a redundant copy of the environment data, so
4317 that there is a valid backup copy in case there is a power failure
4318 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4319 aligned to an erase block boundary.
4321 - CONFIG_ENV_RANGE (optional):
4323 Specifies the length of the region in which the environment
4324 can be written. This should be a multiple of the NAND device's
4325 block size. Specifying a range with more erase blocks than
4326 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4327 the range to be avoided.
4329 - CONFIG_ENV_OFFSET_OOB (optional):
4331 Enables support for dynamically retrieving the offset of the
4332 environment from block zero's out-of-band data. The
4333 "nand env.oob" command can be used to record this offset.
4334 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4335 using CONFIG_ENV_OFFSET_OOB.
4337 - CONFIG_NAND_ENV_DST
4339 Defines address in RAM to which the nand_spl code should copy the
4340 environment. If redundant environment is used, it will be copied to
4341 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4343 - CONFIG_ENV_IS_IN_UBI:
4345 Define this if you have an UBI volume that you want to use for the
4346 environment. This has the benefit of wear-leveling the environment
4347 accesses, which is important on NAND.
4349 - CONFIG_ENV_UBI_PART:
4351 Define this to a string that is the mtd partition containing the UBI.
4353 - CONFIG_ENV_UBI_VOLUME:
4355 Define this to the name of the volume that you want to store the
4358 - CONFIG_ENV_UBI_VOLUME_REDUND:
4360 Define this to the name of another volume to store a second copy of
4361 the environment in. This will enable redundant environments in UBI.
4362 It is assumed that both volumes are in the same MTD partition.
4364 - CONFIG_UBI_SILENCE_MSG
4365 - CONFIG_UBIFS_SILENCE_MSG
4367 You will probably want to define these to avoid a really noisy system
4368 when storing the env in UBI.
4370 - CONFIG_ENV_IS_IN_FAT:
4371 Define this if you want to use the FAT file system for the environment.
4373 - FAT_ENV_INTERFACE:
4375 Define this to a string that is the name of the block device.
4377 - FAT_ENV_DEV_AND_PART:
4379 Define this to a string to specify the partition of the device. It can
4382 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4383 - "D:P": device D partition P. Error occurs if device D has no
4386 - "D" or "D:": device D partition 1 if device D has partition
4387 table, or the whole device D if has no partition
4389 - "D:auto": first partition in device D with bootable flag set.
4390 If none, first valid partition in device D. If no
4391 partition table then means device D.
4395 It's a string of the FAT file name. This file use to store the
4399 This should be defined. Otherwise it cannot save the environment file.
4401 - CONFIG_ENV_IS_IN_MMC:
4403 Define this if you have an MMC device which you want to use for the
4406 - CONFIG_SYS_MMC_ENV_DEV:
4408 Specifies which MMC device the environment is stored in.
4410 - CONFIG_SYS_MMC_ENV_PART (optional):
4412 Specifies which MMC partition the environment is stored in. If not
4413 set, defaults to partition 0, the user area. Common values might be
4414 1 (first MMC boot partition), 2 (second MMC boot partition).
4416 - CONFIG_ENV_OFFSET:
4419 These two #defines specify the offset and size of the environment
4420 area within the specified MMC device.
4422 If offset is positive (the usual case), it is treated as relative to
4423 the start of the MMC partition. If offset is negative, it is treated
4424 as relative to the end of the MMC partition. This can be useful if
4425 your board may be fitted with different MMC devices, which have
4426 different sizes for the MMC partitions, and you always want the
4427 environment placed at the very end of the partition, to leave the
4428 maximum possible space before it, to store other data.
4430 These two values are in units of bytes, but must be aligned to an
4431 MMC sector boundary.
4433 - CONFIG_ENV_OFFSET_REDUND (optional):
4435 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4436 hold a redundant copy of the environment data. This provides a
4437 valid backup copy in case the other copy is corrupted, e.g. due
4438 to a power failure during a "saveenv" operation.
4440 This value may also be positive or negative; this is handled in the
4441 same way as CONFIG_ENV_OFFSET.
4443 This value is also in units of bytes, but must also be aligned to
4444 an MMC sector boundary.
4446 - CONFIG_ENV_SIZE_REDUND (optional):
4448 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4449 set. If this value is set, it must be set to the same value as
4452 - CONFIG_SYS_SPI_INIT_OFFSET
4454 Defines offset to the initial SPI buffer area in DPRAM. The
4455 area is used at an early stage (ROM part) if the environment
4456 is configured to reside in the SPI EEPROM: We need a 520 byte
4457 scratch DPRAM area. It is used between the two initialization
4458 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4459 to be a good choice since it makes it far enough from the
4460 start of the data area as well as from the stack pointer.
4462 Please note that the environment is read-only until the monitor
4463 has been relocated to RAM and a RAM copy of the environment has been
4464 created; also, when using EEPROM you will have to use getenv_f()
4465 until then to read environment variables.
4467 The environment is protected by a CRC32 checksum. Before the monitor
4468 is relocated into RAM, as a result of a bad CRC you will be working
4469 with the compiled-in default environment - *silently*!!! [This is
4470 necessary, because the first environment variable we need is the
4471 "baudrate" setting for the console - if we have a bad CRC, we don't
4472 have any device yet where we could complain.]
4474 Note: once the monitor has been relocated, then it will complain if
4475 the default environment is used; a new CRC is computed as soon as you
4476 use the "saveenv" command to store a valid environment.
4478 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4479 Echo the inverted Ethernet link state to the fault LED.
4481 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4482 also needs to be defined.
4484 - CONFIG_SYS_FAULT_MII_ADDR:
4485 MII address of the PHY to check for the Ethernet link state.
4487 - CONFIG_NS16550_MIN_FUNCTIONS:
4488 Define this if you desire to only have use of the NS16550_init
4489 and NS16550_putc functions for the serial driver located at
4490 drivers/serial/ns16550.c. This option is useful for saving
4491 space for already greatly restricted images, including but not
4492 limited to NAND_SPL configurations.
4494 - CONFIG_DISPLAY_BOARDINFO
4495 Display information about the board that U-Boot is running on
4496 when U-Boot starts up. The board function checkboard() is called
4499 - CONFIG_DISPLAY_BOARDINFO_LATE
4500 Similar to the previous option, but display this information
4501 later, once stdio is running and output goes to the LCD, if
4504 - CONFIG_BOARD_SIZE_LIMIT:
4505 Maximum size of the U-Boot image. When defined, the
4506 build system checks that the actual size does not
4509 Low Level (hardware related) configuration options:
4510 ---------------------------------------------------
4512 - CONFIG_SYS_CACHELINE_SIZE:
4513 Cache Line Size of the CPU.
4515 - CONFIG_SYS_DEFAULT_IMMR:
4516 Default address of the IMMR after system reset.
4518 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4519 and RPXsuper) to be able to adjust the position of
4520 the IMMR register after a reset.
4522 - CONFIG_SYS_CCSRBAR_DEFAULT:
4523 Default (power-on reset) physical address of CCSR on Freescale
4526 - CONFIG_SYS_CCSRBAR:
4527 Virtual address of CCSR. On a 32-bit build, this is typically
4528 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4530 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4531 for cross-platform code that uses that macro instead.
4533 - CONFIG_SYS_CCSRBAR_PHYS:
4534 Physical address of CCSR. CCSR can be relocated to a new
4535 physical address, if desired. In this case, this macro should
4536 be set to that address. Otherwise, it should be set to the
4537 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4538 is typically relocated on 36-bit builds. It is recommended
4539 that this macro be defined via the _HIGH and _LOW macros:
4541 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4542 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4544 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4545 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4546 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4547 used in assembly code, so it must not contain typecasts or
4548 integer size suffixes (e.g. "ULL").
4550 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4551 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4552 used in assembly code, so it must not contain typecasts or
4553 integer size suffixes (e.g. "ULL").
4555 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4556 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4557 forced to a value that ensures that CCSR is not relocated.
4559 - Floppy Disk Support:
4560 CONFIG_SYS_FDC_DRIVE_NUMBER
4562 the default drive number (default value 0)
4564 CONFIG_SYS_ISA_IO_STRIDE
4566 defines the spacing between FDC chipset registers
4569 CONFIG_SYS_ISA_IO_OFFSET
4571 defines the offset of register from address. It
4572 depends on which part of the data bus is connected to
4573 the FDC chipset. (default value 0)
4575 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4576 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4579 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4580 fdc_hw_init() is called at the beginning of the FDC
4581 setup. fdc_hw_init() must be provided by the board
4582 source code. It is used to make hardware-dependent
4586 Most IDE controllers were designed to be connected with PCI
4587 interface. Only few of them were designed for AHB interface.
4588 When software is doing ATA command and data transfer to
4589 IDE devices through IDE-AHB controller, some additional
4590 registers accessing to these kind of IDE-AHB controller
4593 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4594 DO NOT CHANGE unless you know exactly what you're
4595 doing! (11-4) [MPC8xx/82xx systems only]
4597 - CONFIG_SYS_INIT_RAM_ADDR:
4599 Start address of memory area that can be used for
4600 initial data and stack; please note that this must be
4601 writable memory that is working WITHOUT special
4602 initialization, i. e. you CANNOT use normal RAM which
4603 will become available only after programming the
4604 memory controller and running certain initialization
4607 U-Boot uses the following memory types:
4608 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4609 - MPC824X: data cache
4610 - PPC4xx: data cache
4612 - CONFIG_SYS_GBL_DATA_OFFSET:
4614 Offset of the initial data structure in the memory
4615 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4616 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4617 data is located at the end of the available space
4618 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4619 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4620 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4621 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4624 On the MPC824X (or other systems that use the data
4625 cache for initial memory) the address chosen for
4626 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4627 point to an otherwise UNUSED address space between
4628 the top of RAM and the start of the PCI space.
4630 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4632 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4634 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4636 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4638 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4640 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4642 - CONFIG_SYS_OR_TIMING_SDRAM:
4645 - CONFIG_SYS_MAMR_PTA:
4646 periodic timer for refresh
4648 - CONFIG_SYS_DER: Debug Event Register (37-47)
4650 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4651 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4652 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4653 CONFIG_SYS_BR1_PRELIM:
4654 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4656 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4657 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4658 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4659 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4661 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4662 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4663 Machine Mode Register and Memory Periodic Timer
4664 Prescaler definitions (SDRAM timing)
4666 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4667 enable I2C microcode relocation patch (MPC8xx);
4668 define relocation offset in DPRAM [DSP2]
4670 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4671 enable SMC microcode relocation patch (MPC8xx);
4672 define relocation offset in DPRAM [SMC1]
4674 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4675 enable SPI microcode relocation patch (MPC8xx);
4676 define relocation offset in DPRAM [SCC4]
4678 - CONFIG_SYS_USE_OSCCLK:
4679 Use OSCM clock mode on MBX8xx board. Be careful,
4680 wrong setting might damage your board. Read
4681 doc/README.MBX before setting this variable!
4683 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4684 Offset of the bootmode word in DPRAM used by post
4685 (Power On Self Tests). This definition overrides
4686 #define'd default value in commproc.h resp.
4689 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4690 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4691 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4692 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4693 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4694 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4695 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4696 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4697 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4699 - CONFIG_PCI_DISABLE_PCIE:
4700 Disable PCI-Express on systems where it is supported but not
4703 - CONFIG_PCI_ENUM_ONLY
4704 Only scan through and get the devices on the buses.
4705 Don't do any setup work, presumably because someone or
4706 something has already done it, and we don't need to do it
4707 a second time. Useful for platforms that are pre-booted
4708 by coreboot or similar.
4710 - CONFIG_PCI_INDIRECT_BRIDGE:
4711 Enable support for indirect PCI bridges.
4714 Chip has SRIO or not
4717 Board has SRIO 1 port available
4720 Board has SRIO 2 port available
4722 - CONFIG_SRIO_PCIE_BOOT_MASTER
4723 Board can support master function for Boot from SRIO and PCIE
4725 - CONFIG_SYS_SRIOn_MEM_VIRT:
4726 Virtual Address of SRIO port 'n' memory region
4728 - CONFIG_SYS_SRIOn_MEM_PHYS:
4729 Physical Address of SRIO port 'n' memory region
4731 - CONFIG_SYS_SRIOn_MEM_SIZE:
4732 Size of SRIO port 'n' memory region
4734 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4735 Defined to tell the NAND controller that the NAND chip is using
4737 Not all NAND drivers use this symbol.
4738 Example of drivers that use it:
4739 - drivers/mtd/nand/ndfc.c
4740 - drivers/mtd/nand/mxc_nand.c
4742 - CONFIG_SYS_NDFC_EBC0_CFG
4743 Sets the EBC0_CFG register for the NDFC. If not defined
4744 a default value will be used.
4747 Get DDR timing information from an I2C EEPROM. Common
4748 with pluggable memory modules such as SODIMMs
4751 I2C address of the SPD EEPROM
4753 - CONFIG_SYS_SPD_BUS_NUM
4754 If SPD EEPROM is on an I2C bus other than the first
4755 one, specify here. Note that the value must resolve
4756 to something your driver can deal with.
4758 - CONFIG_SYS_DDR_RAW_TIMING
4759 Get DDR timing information from other than SPD. Common with
4760 soldered DDR chips onboard without SPD. DDR raw timing
4761 parameters are extracted from datasheet and hard-coded into
4762 header files or board specific files.
4764 - CONFIG_FSL_DDR_INTERACTIVE
4765 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4767 - CONFIG_FSL_DDR_SYNC_REFRESH
4768 Enable sync of refresh for multiple controllers.
4770 - CONFIG_FSL_DDR_BIST
4771 Enable built-in memory test for Freescale DDR controllers.
4773 - CONFIG_SYS_83XX_DDR_USES_CS0
4774 Only for 83xx systems. If specified, then DDR should
4775 be configured using CS0 and CS1 instead of CS2 and CS3.
4777 - CONFIG_ETHER_ON_FEC[12]
4778 Define to enable FEC[12] on a 8xx series processor.
4780 - CONFIG_FEC[12]_PHY
4781 Define to the hardcoded PHY address which corresponds
4782 to the given FEC; i. e.
4783 #define CONFIG_FEC1_PHY 4
4784 means that the PHY with address 4 is connected to FEC1
4786 When set to -1, means to probe for first available.
4788 - CONFIG_FEC[12]_PHY_NORXERR
4789 The PHY does not have a RXERR line (RMII only).
4790 (so program the FEC to ignore it).
4793 Enable RMII mode for all FECs.
4794 Note that this is a global option, we can't
4795 have one FEC in standard MII mode and another in RMII mode.
4797 - CONFIG_CRC32_VERIFY
4798 Add a verify option to the crc32 command.
4801 => crc32 -v <address> <count> <crc32>
4803 Where address/count indicate a memory area
4804 and crc32 is the correct crc32 which the
4808 Add the "loopw" memory command. This only takes effect if
4809 the memory commands are activated globally (CONFIG_CMD_MEM).
4812 Add the "mdc" and "mwc" memory commands. These are cyclic
4817 This command will print 4 bytes (10,11,12,13) each 500 ms.
4819 => mwc.l 100 12345678 10
4820 This command will write 12345678 to address 100 all 10 ms.
4822 This only takes effect if the memory commands are activated
4823 globally (CONFIG_CMD_MEM).
4825 - CONFIG_SKIP_LOWLEVEL_INIT
4826 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4827 low level initializations (like setting up the memory
4828 controller) are omitted and/or U-Boot does not
4829 relocate itself into RAM.
4831 Normally this variable MUST NOT be defined. The only
4832 exception is when U-Boot is loaded (to RAM) by some
4833 other boot loader or by a debugger which performs
4834 these initializations itself.
4837 Modifies the behaviour of start.S when compiling a loader
4838 that is executed before the actual U-Boot. E.g. when
4839 compiling a NAND SPL.
4842 Modifies the behaviour of start.S when compiling a loader
4843 that is executed after the SPL and before the actual U-Boot.
4844 It is loaded by the SPL.
4846 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4847 Only for 85xx systems. If this variable is specified, the section
4848 .resetvec is not kept and the section .bootpg is placed in the
4849 previous 4k of the .text section.
4851 - CONFIG_ARCH_MAP_SYSMEM
4852 Generally U-Boot (and in particular the md command) uses
4853 effective address. It is therefore not necessary to regard
4854 U-Boot address as virtual addresses that need to be translated
4855 to physical addresses. However, sandbox requires this, since
4856 it maintains its own little RAM buffer which contains all
4857 addressable memory. This option causes some memory accesses
4858 to be mapped through map_sysmem() / unmap_sysmem().
4860 - CONFIG_USE_ARCH_MEMCPY
4861 CONFIG_USE_ARCH_MEMSET
4862 If these options are used a optimized version of memcpy/memset will
4863 be used if available. These functions may be faster under some
4864 conditions but may increase the binary size.
4866 - CONFIG_X86_RESET_VECTOR
4867 If defined, the x86 reset vector code is included. This is not
4868 needed when U-Boot is running from Coreboot.
4871 Defines the MPU clock speed (in MHz).
4873 NOTE : currently only supported on AM335x platforms.
4875 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4876 Enables the RTC32K OSC on AM33xx based plattforms
4878 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4879 Option to disable subpage write in NAND driver
4880 driver that uses this:
4881 drivers/mtd/nand/davinci_nand.c
4883 Freescale QE/FMAN Firmware Support:
4884 -----------------------------------
4886 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4887 loading of "firmware", which is encoded in the QE firmware binary format.
4888 This firmware often needs to be loaded during U-Boot booting, so macros
4889 are used to identify the storage device (NOR flash, SPI, etc) and the address
4892 - CONFIG_SYS_FMAN_FW_ADDR
4893 The address in the storage device where the FMAN microcode is located. The
4894 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4897 - CONFIG_SYS_QE_FW_ADDR
4898 The address in the storage device where the QE microcode is located. The
4899 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4902 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4903 The maximum possible size of the firmware. The firmware binary format
4904 has a field that specifies the actual size of the firmware, but it
4905 might not be possible to read any part of the firmware unless some
4906 local storage is allocated to hold the entire firmware first.
4908 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4909 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4910 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4911 virtual address in NOR flash.
4913 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4914 Specifies that QE/FMAN firmware is located in NAND flash.
4915 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4917 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4918 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4919 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4921 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4922 Specifies that QE/FMAN firmware is located on the primary SPI
4923 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4925 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4926 Specifies that QE/FMAN firmware is located in the remote (master)
4927 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4928 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4929 window->master inbound window->master LAW->the ucode address in
4930 master's memory space.
4932 Freescale Layerscape Management Complex Firmware Support:
4933 ---------------------------------------------------------
4934 The Freescale Layerscape Management Complex (MC) supports the loading of
4936 This firmware often needs to be loaded during U-Boot booting, so macros
4937 are used to identify the storage device (NOR flash, SPI, etc) and the address
4940 - CONFIG_FSL_MC_ENET
4941 Enable the MC driver for Layerscape SoCs.
4943 - CONFIG_SYS_LS_MC_FW_ADDR
4944 The address in the storage device where the firmware is located. The
4945 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4948 - CONFIG_SYS_LS_MC_FW_LENGTH
4949 The maximum possible size of the firmware. The firmware binary format
4950 has a field that specifies the actual size of the firmware, but it
4951 might not be possible to read any part of the firmware unless some
4952 local storage is allocated to hold the entire firmware first.
4954 - CONFIG_SYS_LS_MC_FW_IN_NOR
4955 Specifies that MC firmware is located in NOR flash, mapped as
4956 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4957 virtual address in NOR flash.
4959 Freescale Layerscape Debug Server Support:
4960 -------------------------------------------
4961 The Freescale Layerscape Debug Server Support supports the loading of
4962 "Debug Server firmware" and triggering SP boot-rom.
4963 This firmware often needs to be loaded during U-Boot booting.
4965 - CONFIG_FSL_DEBUG_SERVER
4966 Enable the Debug Server for Layerscape SoCs.
4968 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
4969 Define minimum DDR size required for debug server image
4971 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4972 Define alignment of reserved memory MC requires
4977 In order to achieve reproducible builds, timestamps used in the U-Boot build
4978 process have to be set to a fixed value.
4980 This is done using the SOURCE_DATE_EPOCH environment variable.
4981 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4982 option for U-Boot or an environment variable in U-Boot.
4984 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4986 Building the Software:
4987 ======================
4989 Building U-Boot has been tested in several native build environments
4990 and in many different cross environments. Of course we cannot support
4991 all possibly existing versions of cross development tools in all
4992 (potentially obsolete) versions. In case of tool chain problems we
4993 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4994 which is extensively used to build and test U-Boot.
4996 If you are not using a native environment, it is assumed that you
4997 have GNU cross compiling tools available in your path. In this case,
4998 you must set the environment variable CROSS_COMPILE in your shell.
4999 Note that no changes to the Makefile or any other source files are
5000 necessary. For example using the ELDK on a 4xx CPU, please enter:
5002 $ CROSS_COMPILE=ppc_4xx-
5003 $ export CROSS_COMPILE
5005 Note: If you wish to generate Windows versions of the utilities in
5006 the tools directory you can use the MinGW toolchain
5007 (http://www.mingw.org). Set your HOST tools to the MinGW
5008 toolchain and execute 'make tools'. For example:
5010 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5012 Binaries such as tools/mkimage.exe will be created which can
5013 be executed on computers running Windows.
5015 U-Boot is intended to be simple to build. After installing the
5016 sources you must configure U-Boot for one specific board type. This
5021 where "NAME_defconfig" is the name of one of the existing configu-
5022 rations; see boards.cfg for supported names.
5024 Note: for some board special configuration names may exist; check if
5025 additional information is available from the board vendor; for
5026 instance, the TQM823L systems are available without (standard)
5027 or with LCD support. You can select such additional "features"
5028 when choosing the configuration, i. e.
5030 make TQM823L_defconfig
5031 - will configure for a plain TQM823L, i. e. no LCD support
5033 make TQM823L_LCD_defconfig
5034 - will configure for a TQM823L with U-Boot console on LCD
5039 Finally, type "make all", and you should get some working U-Boot
5040 images ready for download to / installation on your system:
5042 - "u-boot.bin" is a raw binary image
5043 - "u-boot" is an image in ELF binary format
5044 - "u-boot.srec" is in Motorola S-Record format
5046 By default the build is performed locally and the objects are saved
5047 in the source directory. One of the two methods can be used to change
5048 this behavior and build U-Boot to some external directory:
5050 1. Add O= to the make command line invocations:
5052 make O=/tmp/build distclean
5053 make O=/tmp/build NAME_defconfig
5054 make O=/tmp/build all
5056 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5058 export KBUILD_OUTPUT=/tmp/build
5063 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5067 Please be aware that the Makefiles assume you are using GNU make, so
5068 for instance on NetBSD you might need to use "gmake" instead of
5072 If the system board that you have is not listed, then you will need
5073 to port U-Boot to your hardware platform. To do this, follow these
5076 1. Create a new directory to hold your board specific code. Add any
5077 files you need. In your board directory, you will need at least
5078 the "Makefile" and a "<board>.c".
5079 2. Create a new configuration file "include/configs/<board>.h" for
5081 3. If you're porting U-Boot to a new CPU, then also create a new
5082 directory to hold your CPU specific code. Add any files you need.
5083 4. Run "make <board>_defconfig" with your new name.
5084 5. Type "make", and you should get a working "u-boot.srec" file
5085 to be installed on your target system.
5086 6. Debug and solve any problems that might arise.
5087 [Of course, this last step is much harder than it sounds.]
5090 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5091 ==============================================================
5093 If you have modified U-Boot sources (for instance added a new board
5094 or support for new devices, a new CPU, etc.) you are expected to
5095 provide feedback to the other developers. The feedback normally takes
5096 the form of a "patch", i. e. a context diff against a certain (latest
5097 official or latest in the git repository) version of U-Boot sources.
5099 But before you submit such a patch, please verify that your modifi-
5100 cation did not break existing code. At least make sure that *ALL* of
5101 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5102 just run the "MAKEALL" script, which will configure and build U-Boot
5103 for ALL supported system. Be warned, this will take a while. You can
5104 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5105 environment variable to the script, i. e. to use the ELDK cross tools
5108 CROSS_COMPILE=ppc_8xx- MAKEALL
5110 or to build on a native PowerPC system you can type
5112 CROSS_COMPILE=' ' MAKEALL
5114 When using the MAKEALL script, the default behaviour is to build
5115 U-Boot in the source directory. This location can be changed by
5116 setting the BUILD_DIR environment variable. Also, for each target
5117 built, the MAKEALL script saves two log files (<target>.ERR and
5118 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5119 location can be changed by setting the MAKEALL_LOGDIR environment
5120 variable. For example:
5122 export BUILD_DIR=/tmp/build
5123 export MAKEALL_LOGDIR=/tmp/log
5124 CROSS_COMPILE=ppc_8xx- MAKEALL
5126 With the above settings build objects are saved in the /tmp/build,
5127 log files are saved in the /tmp/log and the source tree remains clean
5128 during the whole build process.
5131 See also "U-Boot Porting Guide" below.
5134 Monitor Commands - Overview:
5135 ============================
5137 go - start application at address 'addr'
5138 run - run commands in an environment variable
5139 bootm - boot application image from memory
5140 bootp - boot image via network using BootP/TFTP protocol
5141 bootz - boot zImage from memory
5142 tftpboot- boot image via network using TFTP protocol
5143 and env variables "ipaddr" and "serverip"
5144 (and eventually "gatewayip")
5145 tftpput - upload a file via network using TFTP protocol
5146 rarpboot- boot image via network using RARP/TFTP protocol
5147 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5148 loads - load S-Record file over serial line
5149 loadb - load binary file over serial line (kermit mode)
5151 mm - memory modify (auto-incrementing)
5152 nm - memory modify (constant address)
5153 mw - memory write (fill)
5155 cmp - memory compare
5156 crc32 - checksum calculation
5157 i2c - I2C sub-system
5158 sspi - SPI utility commands
5159 base - print or set address offset
5160 printenv- print environment variables
5161 setenv - set environment variables
5162 saveenv - save environment variables to persistent storage
5163 protect - enable or disable FLASH write protection
5164 erase - erase FLASH memory
5165 flinfo - print FLASH memory information
5166 nand - NAND memory operations (see doc/README.nand)
5167 bdinfo - print Board Info structure
5168 iminfo - print header information for application image
5169 coninfo - print console devices and informations
5170 ide - IDE sub-system
5171 loop - infinite loop on address range
5172 loopw - infinite write loop on address range
5173 mtest - simple RAM test
5174 icache - enable or disable instruction cache
5175 dcache - enable or disable data cache
5176 reset - Perform RESET of the CPU
5177 echo - echo args to console
5178 version - print monitor version
5179 help - print online help
5180 ? - alias for 'help'
5183 Monitor Commands - Detailed Description:
5184 ========================================
5188 For now: just type "help <command>".
5191 Environment Variables:
5192 ======================
5194 U-Boot supports user configuration using Environment Variables which
5195 can be made persistent by saving to Flash memory.
5197 Environment Variables are set using "setenv", printed using
5198 "printenv", and saved to Flash using "saveenv". Using "setenv"
5199 without a value can be used to delete a variable from the
5200 environment. As long as you don't save the environment you are
5201 working with an in-memory copy. In case the Flash area containing the
5202 environment is erased by accident, a default environment is provided.
5204 Some configuration options can be set using Environment Variables.
5206 List of environment variables (most likely not complete):
5208 baudrate - see CONFIG_BAUDRATE
5210 bootdelay - see CONFIG_BOOTDELAY
5212 bootcmd - see CONFIG_BOOTCOMMAND
5214 bootargs - Boot arguments when booting an RTOS image
5216 bootfile - Name of the image to load with TFTP
5218 bootm_low - Memory range available for image processing in the bootm
5219 command can be restricted. This variable is given as
5220 a hexadecimal number and defines lowest address allowed
5221 for use by the bootm command. See also "bootm_size"
5222 environment variable. Address defined by "bootm_low" is
5223 also the base of the initial memory mapping for the Linux
5224 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5227 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5228 This variable is given as a hexadecimal number and it
5229 defines the size of the memory region starting at base
5230 address bootm_low that is accessible by the Linux kernel
5231 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5232 as the default value if it is defined, and bootm_size is
5235 bootm_size - Memory range available for image processing in the bootm
5236 command can be restricted. This variable is given as
5237 a hexadecimal number and defines the size of the region
5238 allowed for use by the bootm command. See also "bootm_low"
5239 environment variable.
5241 updatefile - Location of the software update file on a TFTP server, used
5242 by the automatic software update feature. Please refer to
5243 documentation in doc/README.update for more details.
5245 autoload - if set to "no" (any string beginning with 'n'),
5246 "bootp" will just load perform a lookup of the
5247 configuration from the BOOTP server, but not try to
5248 load any image using TFTP
5250 autostart - if set to "yes", an image loaded using the "bootp",
5251 "rarpboot", "tftpboot" or "diskboot" commands will
5252 be automatically started (by internally calling
5255 If set to "no", a standalone image passed to the
5256 "bootm" command will be copied to the load address
5257 (and eventually uncompressed), but NOT be started.
5258 This can be used to load and uncompress arbitrary
5261 fdt_high - if set this restricts the maximum address that the
5262 flattened device tree will be copied into upon boot.
5263 For example, if you have a system with 1 GB memory
5264 at physical address 0x10000000, while Linux kernel
5265 only recognizes the first 704 MB as low memory, you
5266 may need to set fdt_high as 0x3C000000 to have the
5267 device tree blob be copied to the maximum address
5268 of the 704 MB low memory, so that Linux kernel can
5269 access it during the boot procedure.
5271 If this is set to the special value 0xFFFFFFFF then
5272 the fdt will not be copied at all on boot. For this
5273 to work it must reside in writable memory, have
5274 sufficient padding on the end of it for u-boot to
5275 add the information it needs into it, and the memory
5276 must be accessible by the kernel.
5278 fdtcontroladdr- if set this is the address of the control flattened
5279 device tree used by U-Boot when CONFIG_OF_CONTROL is
5282 i2cfast - (PPC405GP|PPC405EP only)
5283 if set to 'y' configures Linux I2C driver for fast
5284 mode (400kHZ). This environment variable is used in
5285 initialization code. So, for changes to be effective
5286 it must be saved and board must be reset.
5288 initrd_high - restrict positioning of initrd images:
5289 If this variable is not set, initrd images will be
5290 copied to the highest possible address in RAM; this
5291 is usually what you want since it allows for
5292 maximum initrd size. If for some reason you want to
5293 make sure that the initrd image is loaded below the
5294 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5295 variable to a value of "no" or "off" or "0".
5296 Alternatively, you can set it to a maximum upper
5297 address to use (U-Boot will still check that it
5298 does not overwrite the U-Boot stack and data).
5300 For instance, when you have a system with 16 MB
5301 RAM, and want to reserve 4 MB from use by Linux,
5302 you can do this by adding "mem=12M" to the value of
5303 the "bootargs" variable. However, now you must make
5304 sure that the initrd image is placed in the first
5305 12 MB as well - this can be done with
5307 setenv initrd_high 00c00000
5309 If you set initrd_high to 0xFFFFFFFF, this is an
5310 indication to U-Boot that all addresses are legal
5311 for the Linux kernel, including addresses in flash
5312 memory. In this case U-Boot will NOT COPY the
5313 ramdisk at all. This may be useful to reduce the
5314 boot time on your system, but requires that this
5315 feature is supported by your Linux kernel.
5317 ipaddr - IP address; needed for tftpboot command
5319 loadaddr - Default load address for commands like "bootp",
5320 "rarpboot", "tftpboot", "loadb" or "diskboot"
5322 loads_echo - see CONFIG_LOADS_ECHO
5324 serverip - TFTP server IP address; needed for tftpboot command
5326 bootretry - see CONFIG_BOOT_RETRY_TIME
5328 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5330 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5332 ethprime - controls which interface is used first.
5334 ethact - controls which interface is currently active.
5335 For example you can do the following
5337 => setenv ethact FEC
5338 => ping 192.168.0.1 # traffic sent on FEC
5339 => setenv ethact SCC
5340 => ping 10.0.0.1 # traffic sent on SCC
5342 ethrotate - When set to "no" U-Boot does not go through all
5343 available network interfaces.
5344 It just stays at the currently selected interface.
5346 netretry - When set to "no" each network operation will
5347 either succeed or fail without retrying.
5348 When set to "once" the network operation will
5349 fail when all the available network interfaces
5350 are tried once without success.
5351 Useful on scripts which control the retry operation
5354 npe_ucode - set load address for the NPE microcode
5356 silent_linux - If set then Linux will be told to boot silently, by
5357 changing the console to be empty. If "yes" it will be
5358 made silent. If "no" it will not be made silent. If
5359 unset, then it will be made silent if the U-Boot console
5362 tftpsrcp - If this is set, the value is used for TFTP's
5365 tftpdstp - If this is set, the value is used for TFTP's UDP
5366 destination port instead of the Well Know Port 69.
5368 tftpblocksize - Block size to use for TFTP transfers; if not set,
5369 we use the TFTP server's default block size
5371 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5372 seconds, minimum value is 1000 = 1 second). Defines
5373 when a packet is considered to be lost so it has to
5374 be retransmitted. The default is 5000 = 5 seconds.
5375 Lowering this value may make downloads succeed
5376 faster in networks with high packet loss rates or
5377 with unreliable TFTP servers.
5379 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5380 unit, minimum value = 0). Defines how many timeouts
5381 can happen during a single file transfer before that
5382 transfer is aborted. The default is 10, and 0 means
5383 'no timeouts allowed'. Increasing this value may help
5384 downloads succeed with high packet loss rates, or with
5385 unreliable TFTP servers or client hardware.
5387 vlan - When set to a value < 4095 the traffic over
5388 Ethernet is encapsulated/received over 802.1q
5391 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5392 Unsigned value, in milliseconds. If not set, the period will
5393 be either the default (28000), or a value based on
5394 CONFIG_NET_RETRY_COUNT, if defined. This value has
5395 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5397 The following image location variables contain the location of images
5398 used in booting. The "Image" column gives the role of the image and is
5399 not an environment variable name. The other columns are environment
5400 variable names. "File Name" gives the name of the file on a TFTP
5401 server, "RAM Address" gives the location in RAM the image will be
5402 loaded to, and "Flash Location" gives the image's address in NOR
5403 flash or offset in NAND flash.
5405 *Note* - these variables don't have to be defined for all boards, some
5406 boards currently use other variables for these purposes, and some
5407 boards use these variables for other purposes.
5409 Image File Name RAM Address Flash Location
5410 ----- --------- ----------- --------------
5411 u-boot u-boot u-boot_addr_r u-boot_addr
5412 Linux kernel bootfile kernel_addr_r kernel_addr
5413 device tree blob fdtfile fdt_addr_r fdt_addr
5414 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5416 The following environment variables may be used and automatically
5417 updated by the network boot commands ("bootp" and "rarpboot"),
5418 depending the information provided by your boot server:
5420 bootfile - see above
5421 dnsip - IP address of your Domain Name Server
5422 dnsip2 - IP address of your secondary Domain Name Server
5423 gatewayip - IP address of the Gateway (Router) to use
5424 hostname - Target hostname
5426 netmask - Subnet Mask
5427 rootpath - Pathname of the root filesystem on the NFS server
5428 serverip - see above
5431 There are two special Environment Variables:
5433 serial# - contains hardware identification information such
5434 as type string and/or serial number
5435 ethaddr - Ethernet address
5437 These variables can be set only once (usually during manufacturing of
5438 the board). U-Boot refuses to delete or overwrite these variables
5439 once they have been set once.
5442 Further special Environment Variables:
5444 ver - Contains the U-Boot version string as printed
5445 with the "version" command. This variable is
5446 readonly (see CONFIG_VERSION_VARIABLE).
5449 Please note that changes to some configuration parameters may take
5450 only effect after the next boot (yes, that's just like Windoze :-).
5453 Callback functions for environment variables:
5454 ---------------------------------------------
5456 For some environment variables, the behavior of u-boot needs to change
5457 when their values are changed. This functionality allows functions to
5458 be associated with arbitrary variables. On creation, overwrite, or
5459 deletion, the callback will provide the opportunity for some side
5460 effect to happen or for the change to be rejected.
5462 The callbacks are named and associated with a function using the
5463 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5465 These callbacks are associated with variables in one of two ways. The
5466 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5467 in the board configuration to a string that defines a list of
5468 associations. The list must be in the following format:
5470 entry = variable_name[:callback_name]
5473 If the callback name is not specified, then the callback is deleted.
5474 Spaces are also allowed anywhere in the list.
5476 Callbacks can also be associated by defining the ".callbacks" variable
5477 with the same list format above. Any association in ".callbacks" will
5478 override any association in the static list. You can define
5479 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5480 ".callbacks" environment variable in the default or embedded environment.
5482 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5483 regular expression. This allows multiple variables to be connected to
5484 the same callback without explicitly listing them all out.
5487 Command Line Parsing:
5488 =====================
5490 There are two different command line parsers available with U-Boot:
5491 the old "simple" one, and the much more powerful "hush" shell:
5493 Old, simple command line parser:
5494 --------------------------------
5496 - supports environment variables (through setenv / saveenv commands)
5497 - several commands on one line, separated by ';'
5498 - variable substitution using "... ${name} ..." syntax
5499 - special characters ('$', ';') can be escaped by prefixing with '\',
5501 setenv bootcmd bootm \${address}
5502 - You can also escape text by enclosing in single apostrophes, for example:
5503 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5508 - similar to Bourne shell, with control structures like
5509 if...then...else...fi, for...do...done; while...do...done,
5510 until...do...done, ...
5511 - supports environment ("global") variables (through setenv / saveenv
5512 commands) and local shell variables (through standard shell syntax
5513 "name=value"); only environment variables can be used with "run"
5519 (1) If a command line (or an environment variable executed by a "run"
5520 command) contains several commands separated by semicolon, and
5521 one of these commands fails, then the remaining commands will be
5524 (2) If you execute several variables with one call to run (i. e.
5525 calling run with a list of variables as arguments), any failing
5526 command will cause "run" to terminate, i. e. the remaining
5527 variables are not executed.
5529 Note for Redundant Ethernet Interfaces:
5530 =======================================
5532 Some boards come with redundant Ethernet interfaces; U-Boot supports
5533 such configurations and is capable of automatic selection of a
5534 "working" interface when needed. MAC assignment works as follows:
5536 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5537 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5538 "eth1addr" (=>eth1), "eth2addr", ...
5540 If the network interface stores some valid MAC address (for instance
5541 in SROM), this is used as default address if there is NO correspon-
5542 ding setting in the environment; if the corresponding environment
5543 variable is set, this overrides the settings in the card; that means:
5545 o If the SROM has a valid MAC address, and there is no address in the
5546 environment, the SROM's address is used.
5548 o If there is no valid address in the SROM, and a definition in the
5549 environment exists, then the value from the environment variable is
5552 o If both the SROM and the environment contain a MAC address, and
5553 both addresses are the same, this MAC address is used.
5555 o If both the SROM and the environment contain a MAC address, and the
5556 addresses differ, the value from the environment is used and a
5559 o If neither SROM nor the environment contain a MAC address, an error
5560 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5561 a random, locally-assigned MAC is used.
5563 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5564 will be programmed into hardware as part of the initialization process. This
5565 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5566 The naming convention is as follows:
5567 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5572 U-Boot is capable of booting (and performing other auxiliary operations on)
5573 images in two formats:
5575 New uImage format (FIT)
5576 -----------------------
5578 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5579 to Flattened Device Tree). It allows the use of images with multiple
5580 components (several kernels, ramdisks, etc.), with contents protected by
5581 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5587 Old image format is based on binary files which can be basically anything,
5588 preceded by a special header; see the definitions in include/image.h for
5589 details; basically, the header defines the following image properties:
5591 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5592 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5593 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5594 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5596 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5597 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5598 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5599 * Compression Type (uncompressed, gzip, bzip2)
5605 The header is marked by a special Magic Number, and both the header
5606 and the data portions of the image are secured against corruption by
5613 Although U-Boot should support any OS or standalone application
5614 easily, the main focus has always been on Linux during the design of
5617 U-Boot includes many features that so far have been part of some
5618 special "boot loader" code within the Linux kernel. Also, any
5619 "initrd" images to be used are no longer part of one big Linux image;
5620 instead, kernel and "initrd" are separate images. This implementation
5621 serves several purposes:
5623 - the same features can be used for other OS or standalone
5624 applications (for instance: using compressed images to reduce the
5625 Flash memory footprint)
5627 - it becomes much easier to port new Linux kernel versions because
5628 lots of low-level, hardware dependent stuff are done by U-Boot
5630 - the same Linux kernel image can now be used with different "initrd"
5631 images; of course this also means that different kernel images can
5632 be run with the same "initrd". This makes testing easier (you don't
5633 have to build a new "zImage.initrd" Linux image when you just
5634 change a file in your "initrd"). Also, a field-upgrade of the
5635 software is easier now.
5641 Porting Linux to U-Boot based systems:
5642 ---------------------------------------
5644 U-Boot cannot save you from doing all the necessary modifications to
5645 configure the Linux device drivers for use with your target hardware
5646 (no, we don't intend to provide a full virtual machine interface to
5649 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5651 Just make sure your machine specific header file (for instance
5652 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5653 Information structure as we define in include/asm-<arch>/u-boot.h,
5654 and make sure that your definition of IMAP_ADDR uses the same value
5655 as your U-Boot configuration in CONFIG_SYS_IMMR.
5657 Note that U-Boot now has a driver model, a unified model for drivers.
5658 If you are adding a new driver, plumb it into driver model. If there
5659 is no uclass available, you are encouraged to create one. See
5663 Configuring the Linux kernel:
5664 -----------------------------
5666 No specific requirements for U-Boot. Make sure you have some root
5667 device (initial ramdisk, NFS) for your target system.
5670 Building a Linux Image:
5671 -----------------------
5673 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5674 not used. If you use recent kernel source, a new build target
5675 "uImage" will exist which automatically builds an image usable by
5676 U-Boot. Most older kernels also have support for a "pImage" target,
5677 which was introduced for our predecessor project PPCBoot and uses a
5678 100% compatible format.
5682 make TQM850L_defconfig
5687 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5688 encapsulate a compressed Linux kernel image with header information,
5689 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5691 * build a standard "vmlinux" kernel image (in ELF binary format):
5693 * convert the kernel into a raw binary image:
5695 ${CROSS_COMPILE}-objcopy -O binary \
5696 -R .note -R .comment \
5697 -S vmlinux linux.bin
5699 * compress the binary image:
5703 * package compressed binary image for U-Boot:
5705 mkimage -A ppc -O linux -T kernel -C gzip \
5706 -a 0 -e 0 -n "Linux Kernel Image" \
5707 -d linux.bin.gz uImage
5710 The "mkimage" tool can also be used to create ramdisk images for use
5711 with U-Boot, either separated from the Linux kernel image, or
5712 combined into one file. "mkimage" encapsulates the images with a 64
5713 byte header containing information about target architecture,
5714 operating system, image type, compression method, entry points, time
5715 stamp, CRC32 checksums, etc.
5717 "mkimage" can be called in two ways: to verify existing images and
5718 print the header information, or to build new images.
5720 In the first form (with "-l" option) mkimage lists the information
5721 contained in the header of an existing U-Boot image; this includes
5722 checksum verification:
5724 tools/mkimage -l image
5725 -l ==> list image header information
5727 The second form (with "-d" option) is used to build a U-Boot image
5728 from a "data file" which is used as image payload:
5730 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5731 -n name -d data_file image
5732 -A ==> set architecture to 'arch'
5733 -O ==> set operating system to 'os'
5734 -T ==> set image type to 'type'
5735 -C ==> set compression type 'comp'
5736 -a ==> set load address to 'addr' (hex)
5737 -e ==> set entry point to 'ep' (hex)
5738 -n ==> set image name to 'name'
5739 -d ==> use image data from 'datafile'
5741 Right now, all Linux kernels for PowerPC systems use the same load
5742 address (0x00000000), but the entry point address depends on the
5745 - 2.2.x kernels have the entry point at 0x0000000C,
5746 - 2.3.x and later kernels have the entry point at 0x00000000.
5748 So a typical call to build a U-Boot image would read:
5750 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5751 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5752 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5753 > examples/uImage.TQM850L
5754 Image Name: 2.4.4 kernel for TQM850L
5755 Created: Wed Jul 19 02:34:59 2000
5756 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5757 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5758 Load Address: 0x00000000
5759 Entry Point: 0x00000000
5761 To verify the contents of the image (or check for corruption):
5763 -> tools/mkimage -l examples/uImage.TQM850L
5764 Image Name: 2.4.4 kernel for TQM850L
5765 Created: Wed Jul 19 02:34:59 2000
5766 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5767 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5768 Load Address: 0x00000000
5769 Entry Point: 0x00000000
5771 NOTE: for embedded systems where boot time is critical you can trade
5772 speed for memory and install an UNCOMPRESSED image instead: this
5773 needs more space in Flash, but boots much faster since it does not
5774 need to be uncompressed:
5776 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5777 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5778 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5779 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5780 > examples/uImage.TQM850L-uncompressed
5781 Image Name: 2.4.4 kernel for TQM850L
5782 Created: Wed Jul 19 02:34:59 2000
5783 Image Type: PowerPC Linux Kernel Image (uncompressed)
5784 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5785 Load Address: 0x00000000
5786 Entry Point: 0x00000000
5789 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5790 when your kernel is intended to use an initial ramdisk:
5792 -> tools/mkimage -n 'Simple Ramdisk Image' \
5793 > -A ppc -O linux -T ramdisk -C gzip \
5794 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5795 Image Name: Simple Ramdisk Image
5796 Created: Wed Jan 12 14:01:50 2000
5797 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5798 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5799 Load Address: 0x00000000
5800 Entry Point: 0x00000000
5802 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5803 option performs the converse operation of the mkimage's second form (the "-d"
5804 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5807 tools/dumpimage -i image -T type -p position data_file
5808 -i ==> extract from the 'image' a specific 'data_file'
5809 -T ==> set image type to 'type'
5810 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5813 Installing a Linux Image:
5814 -------------------------
5816 To downloading a U-Boot image over the serial (console) interface,
5817 you must convert the image to S-Record format:
5819 objcopy -I binary -O srec examples/image examples/image.srec
5821 The 'objcopy' does not understand the information in the U-Boot
5822 image header, so the resulting S-Record file will be relative to
5823 address 0x00000000. To load it to a given address, you need to
5824 specify the target address as 'offset' parameter with the 'loads'
5827 Example: install the image to address 0x40100000 (which on the
5828 TQM8xxL is in the first Flash bank):
5830 => erase 40100000 401FFFFF
5836 ## Ready for S-Record download ...
5837 ~>examples/image.srec
5838 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5840 15989 15990 15991 15992
5841 [file transfer complete]
5843 ## Start Addr = 0x00000000
5846 You can check the success of the download using the 'iminfo' command;
5847 this includes a checksum verification so you can be sure no data
5848 corruption happened:
5852 ## Checking Image at 40100000 ...
5853 Image Name: 2.2.13 for initrd on TQM850L
5854 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5855 Data Size: 335725 Bytes = 327 kB = 0 MB
5856 Load Address: 00000000
5857 Entry Point: 0000000c
5858 Verifying Checksum ... OK
5864 The "bootm" command is used to boot an application that is stored in
5865 memory (RAM or Flash). In case of a Linux kernel image, the contents
5866 of the "bootargs" environment variable is passed to the kernel as
5867 parameters. You can check and modify this variable using the
5868 "printenv" and "setenv" commands:
5871 => printenv bootargs
5872 bootargs=root=/dev/ram
5874 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5876 => printenv bootargs
5877 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5880 ## Booting Linux kernel at 40020000 ...
5881 Image Name: 2.2.13 for NFS on TQM850L
5882 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5883 Data Size: 381681 Bytes = 372 kB = 0 MB
5884 Load Address: 00000000
5885 Entry Point: 0000000c
5886 Verifying Checksum ... OK
5887 Uncompressing Kernel Image ... OK
5888 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
5889 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5890 time_init: decrementer frequency = 187500000/60
5891 Calibrating delay loop... 49.77 BogoMIPS
5892 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5895 If you want to boot a Linux kernel with initial RAM disk, you pass
5896 the memory addresses of both the kernel and the initrd image (PPBCOOT
5897 format!) to the "bootm" command:
5899 => imi 40100000 40200000
5901 ## Checking Image at 40100000 ...
5902 Image Name: 2.2.13 for initrd on TQM850L
5903 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5904 Data Size: 335725 Bytes = 327 kB = 0 MB
5905 Load Address: 00000000
5906 Entry Point: 0000000c
5907 Verifying Checksum ... OK
5909 ## Checking Image at 40200000 ...
5910 Image Name: Simple Ramdisk Image
5911 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5912 Data Size: 566530 Bytes = 553 kB = 0 MB
5913 Load Address: 00000000
5914 Entry Point: 00000000
5915 Verifying Checksum ... OK
5917 => bootm 40100000 40200000
5918 ## Booting Linux kernel at 40100000 ...
5919 Image Name: 2.2.13 for initrd on TQM850L
5920 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5921 Data Size: 335725 Bytes = 327 kB = 0 MB
5922 Load Address: 00000000
5923 Entry Point: 0000000c
5924 Verifying Checksum ... OK
5925 Uncompressing Kernel Image ... OK
5926 ## Loading RAMDisk Image at 40200000 ...
5927 Image Name: Simple Ramdisk Image
5928 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5929 Data Size: 566530 Bytes = 553 kB = 0 MB
5930 Load Address: 00000000
5931 Entry Point: 00000000
5932 Verifying Checksum ... OK
5933 Loading Ramdisk ... OK
5934 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
5935 Boot arguments: root=/dev/ram
5936 time_init: decrementer frequency = 187500000/60
5937 Calibrating delay loop... 49.77 BogoMIPS
5939 RAMDISK: Compressed image found at block 0
5940 VFS: Mounted root (ext2 filesystem).
5944 Boot Linux and pass a flat device tree:
5947 First, U-Boot must be compiled with the appropriate defines. See the section
5948 titled "Linux Kernel Interface" above for a more in depth explanation. The
5949 following is an example of how to start a kernel and pass an updated
5955 oft=oftrees/mpc8540ads.dtb
5956 => tftp $oftaddr $oft
5957 Speed: 1000, full duplex
5959 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5960 Filename 'oftrees/mpc8540ads.dtb'.
5961 Load address: 0x300000
5964 Bytes transferred = 4106 (100a hex)
5965 => tftp $loadaddr $bootfile
5966 Speed: 1000, full duplex
5968 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5970 Load address: 0x200000
5971 Loading:############
5973 Bytes transferred = 1029407 (fb51f hex)
5978 => bootm $loadaddr - $oftaddr
5979 ## Booting image at 00200000 ...
5980 Image Name: Linux-2.6.17-dirty
5981 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5982 Data Size: 1029343 Bytes = 1005.2 kB
5983 Load Address: 00000000
5984 Entry Point: 00000000
5985 Verifying Checksum ... OK
5986 Uncompressing Kernel Image ... OK
5987 Booting using flat device tree at 0x300000
5988 Using MPC85xx ADS machine description
5989 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5993 More About U-Boot Image Types:
5994 ------------------------------
5996 U-Boot supports the following image types:
5998 "Standalone Programs" are directly runnable in the environment
5999 provided by U-Boot; it is expected that (if they behave
6000 well) you can continue to work in U-Boot after return from
6001 the Standalone Program.
6002 "OS Kernel Images" are usually images of some Embedded OS which
6003 will take over control completely. Usually these programs
6004 will install their own set of exception handlers, device
6005 drivers, set up the MMU, etc. - this means, that you cannot
6006 expect to re-enter U-Boot except by resetting the CPU.
6007 "RAMDisk Images" are more or less just data blocks, and their
6008 parameters (address, size) are passed to an OS kernel that is
6010 "Multi-File Images" contain several images, typically an OS
6011 (Linux) kernel image and one or more data images like
6012 RAMDisks. This construct is useful for instance when you want
6013 to boot over the network using BOOTP etc., where the boot
6014 server provides just a single image file, but you want to get
6015 for instance an OS kernel and a RAMDisk image.
6017 "Multi-File Images" start with a list of image sizes, each
6018 image size (in bytes) specified by an "uint32_t" in network
6019 byte order. This list is terminated by an "(uint32_t)0".
6020 Immediately after the terminating 0 follow the images, one by
6021 one, all aligned on "uint32_t" boundaries (size rounded up to
6022 a multiple of 4 bytes).
6024 "Firmware Images" are binary images containing firmware (like
6025 U-Boot or FPGA images) which usually will be programmed to
6028 "Script files" are command sequences that will be executed by
6029 U-Boot's command interpreter; this feature is especially
6030 useful when you configure U-Boot to use a real shell (hush)
6031 as command interpreter.
6033 Booting the Linux zImage:
6034 -------------------------
6036 On some platforms, it's possible to boot Linux zImage. This is done
6037 using the "bootz" command. The syntax of "bootz" command is the same
6038 as the syntax of "bootm" command.
6040 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6041 kernel with raw initrd images. The syntax is slightly different, the
6042 address of the initrd must be augmented by it's size, in the following
6043 format: "<initrd addres>:<initrd size>".
6049 One of the features of U-Boot is that you can dynamically load and
6050 run "standalone" applications, which can use some resources of
6051 U-Boot like console I/O functions or interrupt services.
6053 Two simple examples are included with the sources:
6058 'examples/hello_world.c' contains a small "Hello World" Demo
6059 application; it is automatically compiled when you build U-Boot.
6060 It's configured to run at address 0x00040004, so you can play with it
6064 ## Ready for S-Record download ...
6065 ~>examples/hello_world.srec
6066 1 2 3 4 5 6 7 8 9 10 11 ...
6067 [file transfer complete]
6069 ## Start Addr = 0x00040004
6071 => go 40004 Hello World! This is a test.
6072 ## Starting application at 0x00040004 ...
6083 Hit any key to exit ...
6085 ## Application terminated, rc = 0x0
6087 Another example, which demonstrates how to register a CPM interrupt
6088 handler with the U-Boot code, can be found in 'examples/timer.c'.
6089 Here, a CPM timer is set up to generate an interrupt every second.
6090 The interrupt service routine is trivial, just printing a '.'
6091 character, but this is just a demo program. The application can be
6092 controlled by the following keys:
6094 ? - print current values og the CPM Timer registers
6095 b - enable interrupts and start timer
6096 e - stop timer and disable interrupts
6097 q - quit application
6100 ## Ready for S-Record download ...
6101 ~>examples/timer.srec
6102 1 2 3 4 5 6 7 8 9 10 11 ...
6103 [file transfer complete]
6105 ## Start Addr = 0x00040004
6108 ## Starting application at 0x00040004 ...
6111 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6114 [q, b, e, ?] Set interval 1000000 us
6117 [q, b, e, ?] ........
6118 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6121 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6124 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6127 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6129 [q, b, e, ?] ...Stopping timer
6131 [q, b, e, ?] ## Application terminated, rc = 0x0
6137 Over time, many people have reported problems when trying to use the
6138 "minicom" terminal emulation program for serial download. I (wd)
6139 consider minicom to be broken, and recommend not to use it. Under
6140 Unix, I recommend to use C-Kermit for general purpose use (and
6141 especially for kermit binary protocol download ("loadb" command), and
6142 use "cu" for S-Record download ("loads" command). See
6143 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6144 for help with kermit.
6147 Nevertheless, if you absolutely want to use it try adding this
6148 configuration to your "File transfer protocols" section:
6150 Name Program Name U/D FullScr IO-Red. Multi
6151 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6152 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6158 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6159 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6161 Building requires a cross environment; it is known to work on
6162 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6163 need gmake since the Makefiles are not compatible with BSD make).
6164 Note that the cross-powerpc package does not install include files;
6165 attempting to build U-Boot will fail because <machine/ansi.h> is
6166 missing. This file has to be installed and patched manually:
6168 # cd /usr/pkg/cross/powerpc-netbsd/include
6170 # ln -s powerpc machine
6171 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6172 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6174 Native builds *don't* work due to incompatibilities between native
6175 and U-Boot include files.
6177 Booting assumes that (the first part of) the image booted is a
6178 stage-2 loader which in turn loads and then invokes the kernel
6179 proper. Loader sources will eventually appear in the NetBSD source
6180 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6181 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6184 Implementation Internals:
6185 =========================
6187 The following is not intended to be a complete description of every
6188 implementation detail. However, it should help to understand the
6189 inner workings of U-Boot and make it easier to port it to custom
6193 Initial Stack, Global Data:
6194 ---------------------------
6196 The implementation of U-Boot is complicated by the fact that U-Boot
6197 starts running out of ROM (flash memory), usually without access to
6198 system RAM (because the memory controller is not initialized yet).
6199 This means that we don't have writable Data or BSS segments, and BSS
6200 is not initialized as zero. To be able to get a C environment working
6201 at all, we have to allocate at least a minimal stack. Implementation
6202 options for this are defined and restricted by the CPU used: Some CPU
6203 models provide on-chip memory (like the IMMR area on MPC8xx and
6204 MPC826x processors), on others (parts of) the data cache can be
6205 locked as (mis-) used as memory, etc.
6207 Chris Hallinan posted a good summary of these issues to the
6208 U-Boot mailing list:
6210 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6211 From: "Chris Hallinan" <clh@net1plus.com>
6212 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6215 Correct me if I'm wrong, folks, but the way I understand it
6216 is this: Using DCACHE as initial RAM for Stack, etc, does not
6217 require any physical RAM backing up the cache. The cleverness
6218 is that the cache is being used as a temporary supply of
6219 necessary storage before the SDRAM controller is setup. It's
6220 beyond the scope of this list to explain the details, but you
6221 can see how this works by studying the cache architecture and
6222 operation in the architecture and processor-specific manuals.
6224 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6225 is another option for the system designer to use as an
6226 initial stack/RAM area prior to SDRAM being available. Either
6227 option should work for you. Using CS 4 should be fine if your
6228 board designers haven't used it for something that would
6229 cause you grief during the initial boot! It is frequently not
6232 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6233 with your processor/board/system design. The default value
6234 you will find in any recent u-boot distribution in
6235 walnut.h should work for you. I'd set it to a value larger
6236 than your SDRAM module. If you have a 64MB SDRAM module, set
6237 it above 400_0000. Just make sure your board has no resources
6238 that are supposed to respond to that address! That code in
6239 start.S has been around a while and should work as is when
6240 you get the config right.
6245 It is essential to remember this, since it has some impact on the C
6246 code for the initialization procedures:
6248 * Initialized global data (data segment) is read-only. Do not attempt
6251 * Do not use any uninitialized global data (or implicitly initialized
6252 as zero data - BSS segment) at all - this is undefined, initiali-
6253 zation is performed later (when relocating to RAM).
6255 * Stack space is very limited. Avoid big data buffers or things like
6258 Having only the stack as writable memory limits means we cannot use
6259 normal global data to share information between the code. But it
6260 turned out that the implementation of U-Boot can be greatly
6261 simplified by making a global data structure (gd_t) available to all
6262 functions. We could pass a pointer to this data as argument to _all_
6263 functions, but this would bloat the code. Instead we use a feature of
6264 the GCC compiler (Global Register Variables) to share the data: we
6265 place a pointer (gd) to the global data into a register which we
6266 reserve for this purpose.
6268 When choosing a register for such a purpose we are restricted by the
6269 relevant (E)ABI specifications for the current architecture, and by
6270 GCC's implementation.
6272 For PowerPC, the following registers have specific use:
6274 R2: reserved for system use
6275 R3-R4: parameter passing and return values
6276 R5-R10: parameter passing
6277 R13: small data area pointer
6281 (U-Boot also uses R12 as internal GOT pointer. r12
6282 is a volatile register so r12 needs to be reset when
6283 going back and forth between asm and C)
6285 ==> U-Boot will use R2 to hold a pointer to the global data
6287 Note: on PPC, we could use a static initializer (since the
6288 address of the global data structure is known at compile time),
6289 but it turned out that reserving a register results in somewhat
6290 smaller code - although the code savings are not that big (on
6291 average for all boards 752 bytes for the whole U-Boot image,
6292 624 text + 127 data).
6294 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6295 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6297 ==> U-Boot will use P3 to hold a pointer to the global data
6299 On ARM, the following registers are used:
6301 R0: function argument word/integer result
6302 R1-R3: function argument word
6303 R9: platform specific
6304 R10: stack limit (used only if stack checking is enabled)
6305 R11: argument (frame) pointer
6306 R12: temporary workspace
6309 R15: program counter
6311 ==> U-Boot will use R9 to hold a pointer to the global data
6313 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6315 On Nios II, the ABI is documented here:
6316 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6318 ==> U-Boot will use gp to hold a pointer to the global data
6320 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6321 to access small data sections, so gp is free.
6323 On NDS32, the following registers are used:
6325 R0-R1: argument/return
6327 R15: temporary register for assembler
6328 R16: trampoline register
6329 R28: frame pointer (FP)
6330 R29: global pointer (GP)
6331 R30: link register (LP)
6332 R31: stack pointer (SP)
6333 PC: program counter (PC)
6335 ==> U-Boot will use R10 to hold a pointer to the global data
6337 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6338 or current versions of GCC may "optimize" the code too much.
6343 U-Boot runs in system state and uses physical addresses, i.e. the
6344 MMU is not used either for address mapping nor for memory protection.
6346 The available memory is mapped to fixed addresses using the memory
6347 controller. In this process, a contiguous block is formed for each
6348 memory type (Flash, SDRAM, SRAM), even when it consists of several
6349 physical memory banks.
6351 U-Boot is installed in the first 128 kB of the first Flash bank (on
6352 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6353 booting and sizing and initializing DRAM, the code relocates itself
6354 to the upper end of DRAM. Immediately below the U-Boot code some
6355 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6356 configuration setting]. Below that, a structure with global Board
6357 Info data is placed, followed by the stack (growing downward).
6359 Additionally, some exception handler code is copied to the low 8 kB
6360 of DRAM (0x00000000 ... 0x00001FFF).
6362 So a typical memory configuration with 16 MB of DRAM could look like
6365 0x0000 0000 Exception Vector code
6368 0x0000 2000 Free for Application Use
6374 0x00FB FF20 Monitor Stack (Growing downward)
6375 0x00FB FFAC Board Info Data and permanent copy of global data
6376 0x00FC 0000 Malloc Arena
6379 0x00FE 0000 RAM Copy of Monitor Code
6380 ... eventually: LCD or video framebuffer
6381 ... eventually: pRAM (Protected RAM - unchanged by reset)
6382 0x00FF FFFF [End of RAM]
6385 System Initialization:
6386 ----------------------
6388 In the reset configuration, U-Boot starts at the reset entry point
6389 (on most PowerPC systems at address 0x00000100). Because of the reset
6390 configuration for CS0# this is a mirror of the on board Flash memory.
6391 To be able to re-map memory U-Boot then jumps to its link address.
6392 To be able to implement the initialization code in C, a (small!)
6393 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6394 which provide such a feature like MPC8xx or MPC8260), or in a locked
6395 part of the data cache. After that, U-Boot initializes the CPU core,
6396 the caches and the SIU.
6398 Next, all (potentially) available memory banks are mapped using a
6399 preliminary mapping. For example, we put them on 512 MB boundaries
6400 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6401 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6402 programmed for SDRAM access. Using the temporary configuration, a
6403 simple memory test is run that determines the size of the SDRAM
6406 When there is more than one SDRAM bank, and the banks are of
6407 different size, the largest is mapped first. For equal size, the first
6408 bank (CS2#) is mapped first. The first mapping is always for address
6409 0x00000000, with any additional banks following immediately to create
6410 contiguous memory starting from 0.
6412 Then, the monitor installs itself at the upper end of the SDRAM area
6413 and allocates memory for use by malloc() and for the global Board
6414 Info data; also, the exception vector code is copied to the low RAM
6415 pages, and the final stack is set up.
6417 Only after this relocation will you have a "normal" C environment;
6418 until that you are restricted in several ways, mostly because you are
6419 running from ROM, and because the code will have to be relocated to a
6423 U-Boot Porting Guide:
6424 ----------------------
6426 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6430 int main(int argc, char *argv[])
6432 sighandler_t no_more_time;
6434 signal(SIGALRM, no_more_time);
6435 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6437 if (available_money > available_manpower) {
6438 Pay consultant to port U-Boot;
6442 Download latest U-Boot source;
6444 Subscribe to u-boot mailing list;
6447 email("Hi, I am new to U-Boot, how do I get started?");
6450 Read the README file in the top level directory;
6451 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6452 Read applicable doc/*.README;
6453 Read the source, Luke;
6454 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6457 if (available_money > toLocalCurrency ($2500))
6460 Add a lot of aggravation and time;
6462 if (a similar board exists) { /* hopefully... */
6463 cp -a board/<similar> board/<myboard>
6464 cp include/configs/<similar>.h include/configs/<myboard>.h
6466 Create your own board support subdirectory;
6467 Create your own board include/configs/<myboard>.h file;
6469 Edit new board/<myboard> files
6470 Edit new include/configs/<myboard>.h
6475 Add / modify source code;
6479 email("Hi, I am having problems...");
6481 Send patch file to the U-Boot email list;
6482 if (reasonable critiques)
6483 Incorporate improvements from email list code review;
6485 Defend code as written;
6491 void no_more_time (int sig)
6500 All contributions to U-Boot should conform to the Linux kernel
6501 coding style; see the file "Documentation/CodingStyle" and the script
6502 "scripts/Lindent" in your Linux kernel source directory.
6504 Source files originating from a different project (for example the
6505 MTD subsystem) are generally exempt from these guidelines and are not
6506 reformatted to ease subsequent migration to newer versions of those
6509 Please note that U-Boot is implemented in C (and to some small parts in
6510 Assembler); no C++ is used, so please do not use C++ style comments (//)
6513 Please also stick to the following formatting rules:
6514 - remove any trailing white space
6515 - use TAB characters for indentation and vertical alignment, not spaces
6516 - make sure NOT to use DOS '\r\n' line feeds
6517 - do not add more than 2 consecutive empty lines to source files
6518 - do not add trailing empty lines to source files
6520 Submissions which do not conform to the standards may be returned
6521 with a request to reformat the changes.
6527 Since the number of patches for U-Boot is growing, we need to
6528 establish some rules. Submissions which do not conform to these rules
6529 may be rejected, even when they contain important and valuable stuff.
6531 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6533 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6534 see http://lists.denx.de/mailman/listinfo/u-boot
6536 When you send a patch, please include the following information with
6539 * For bug fixes: a description of the bug and how your patch fixes
6540 this bug. Please try to include a way of demonstrating that the
6541 patch actually fixes something.
6543 * For new features: a description of the feature and your
6546 * A CHANGELOG entry as plaintext (separate from the patch)
6548 * For major contributions, add a MAINTAINERS file with your
6549 information and associated file and directory references.
6551 * When you add support for a new board, don't forget to add a
6552 maintainer e-mail address to the boards.cfg file, too.
6554 * If your patch adds new configuration options, don't forget to
6555 document these in the README file.
6557 * The patch itself. If you are using git (which is *strongly*
6558 recommended) you can easily generate the patch using the
6559 "git format-patch". If you then use "git send-email" to send it to
6560 the U-Boot mailing list, you will avoid most of the common problems
6561 with some other mail clients.
6563 If you cannot use git, use "diff -purN OLD NEW". If your version of
6564 diff does not support these options, then get the latest version of
6567 The current directory when running this command shall be the parent
6568 directory of the U-Boot source tree (i. e. please make sure that
6569 your patch includes sufficient directory information for the
6572 We prefer patches as plain text. MIME attachments are discouraged,
6573 and compressed attachments must not be used.
6575 * If one logical set of modifications affects or creates several
6576 files, all these changes shall be submitted in a SINGLE patch file.
6578 * Changesets that contain different, unrelated modifications shall be
6579 submitted as SEPARATE patches, one patch per changeset.
6584 * Before sending the patch, run the MAKEALL script on your patched
6585 source tree and make sure that no errors or warnings are reported
6586 for any of the boards.
6588 * Keep your modifications to the necessary minimum: A patch
6589 containing several unrelated changes or arbitrary reformats will be
6590 returned with a request to re-formatting / split it.
6592 * If you modify existing code, make sure that your new code does not
6593 add to the memory footprint of the code ;-) Small is beautiful!
6594 When adding new features, these should compile conditionally only
6595 (using #ifdef), and the resulting code with the new feature
6596 disabled must not need more memory than the old code without your
6599 * Remember that there is a size limit of 100 kB per message on the
6600 u-boot mailing list. Bigger patches will be moderated. If they are
6601 reasonable and not too big, they will be acknowledged. But patches
6602 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob