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_HWFLOW * RTS/CTS hw flow control
1027 CONFIG_CMD_I2C * I2C serial bus support
1028 CONFIG_CMD_IDE * IDE harddisk support
1029 CONFIG_CMD_IMI iminfo
1030 CONFIG_CMD_IMLS List all images found in NOR flash
1031 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1032 CONFIG_CMD_IMMAP * IMMR dump support
1033 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1034 CONFIG_CMD_IMPORTENV * import an environment
1035 CONFIG_CMD_INI * import data from an ini file into the env
1036 CONFIG_CMD_IRQ * irqinfo
1037 CONFIG_CMD_ITEST Integer/string test of 2 values
1038 CONFIG_CMD_JFFS2 * JFFS2 Support
1039 CONFIG_CMD_KGDB * kgdb
1040 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1041 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1043 CONFIG_CMD_LOADB loadb
1044 CONFIG_CMD_LOADS loads
1045 CONFIG_CMD_MD5SUM * print md5 message digest
1046 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1047 CONFIG_CMD_MEMINFO * Display detailed memory information
1048 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1050 CONFIG_CMD_MEMTEST * mtest
1051 CONFIG_CMD_MISC Misc functions like sleep etc
1052 CONFIG_CMD_MMC * MMC memory mapped support
1053 CONFIG_CMD_MII * MII utility commands
1054 CONFIG_CMD_MTDPARTS * MTD partition support
1055 CONFIG_CMD_NAND * NAND support
1056 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1057 CONFIG_CMD_NFS NFS support
1058 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1059 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1060 CONFIG_CMD_PCI * pciinfo
1061 CONFIG_CMD_PCMCIA * PCMCIA support
1062 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1064 CONFIG_CMD_PORTIO * Port I/O
1065 CONFIG_CMD_READ * Read raw data from partition
1066 CONFIG_CMD_REGINFO * Register dump
1067 CONFIG_CMD_RUN run command in env variable
1068 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1069 CONFIG_CMD_SAVES * save S record dump
1070 CONFIG_CMD_SCSI * SCSI Support
1071 CONFIG_CMD_SDRAM * print SDRAM configuration information
1072 (requires CONFIG_CMD_I2C)
1073 CONFIG_CMD_SETGETDCR Support for DCR Register access
1075 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1076 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1077 (requires CONFIG_CMD_MEMORY)
1078 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1079 CONFIG_CMD_SOURCE "source" command Support
1080 CONFIG_CMD_SPI * SPI serial bus support
1081 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1082 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1083 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1084 CONFIG_CMD_TIMER * access to the system tick timer
1085 CONFIG_CMD_USB * USB support
1086 CONFIG_CMD_CDP * Cisco Discover Protocol support
1087 CONFIG_CMD_MFSL * Microblaze FSL support
1088 CONFIG_CMD_XIMG Load part of Multi Image
1089 CONFIG_CMD_UUID * Generate random UUID or GUID string
1091 EXAMPLE: If you want all functions except of network
1092 support you can write:
1094 #include "config_cmd_all.h"
1095 #undef CONFIG_CMD_NET
1098 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1100 Note: Don't enable the "icache" and "dcache" commands
1101 (configuration option CONFIG_CMD_CACHE) unless you know
1102 what you (and your U-Boot users) are doing. Data
1103 cache cannot be enabled on systems like the 8xx or
1104 8260 (where accesses to the IMMR region must be
1105 uncached), and it cannot be disabled on all other
1106 systems where we (mis-) use the data cache to hold an
1107 initial stack and some data.
1110 XXX - this list needs to get updated!
1112 - Regular expression support:
1114 If this variable is defined, U-Boot is linked against
1115 the SLRE (Super Light Regular Expression) library,
1116 which adds regex support to some commands, as for
1117 example "env grep" and "setexpr".
1121 If this variable is defined, U-Boot will use a device tree
1122 to configure its devices, instead of relying on statically
1123 compiled #defines in the board file. This option is
1124 experimental and only available on a few boards. The device
1125 tree is available in the global data as gd->fdt_blob.
1127 U-Boot needs to get its device tree from somewhere. This can
1128 be done using one of the two options below:
1131 If this variable is defined, U-Boot will embed a device tree
1132 binary in its image. This device tree file should be in the
1133 board directory and called <soc>-<board>.dts. The binary file
1134 is then picked up in board_init_f() and made available through
1135 the global data structure as gd->blob.
1138 If this variable is defined, U-Boot will build a device tree
1139 binary. It will be called u-boot.dtb. Architecture-specific
1140 code will locate it at run-time. Generally this works by:
1142 cat u-boot.bin u-boot.dtb >image.bin
1144 and in fact, U-Boot does this for you, creating a file called
1145 u-boot-dtb.bin which is useful in the common case. You can
1146 still use the individual files if you need something more
1151 If this variable is defined, it enables watchdog
1152 support for the SoC. There must be support in the SoC
1153 specific code for a watchdog. For the 8xx and 8260
1154 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1155 register. When supported for a specific SoC is
1156 available, then no further board specific code should
1157 be needed to use it.
1160 When using a watchdog circuitry external to the used
1161 SoC, then define this variable and provide board
1162 specific code for the "hw_watchdog_reset" function.
1164 CONFIG_AT91_HW_WDT_TIMEOUT
1165 specify the timeout in seconds. default 2 seconds.
1168 CONFIG_VERSION_VARIABLE
1169 If this variable is defined, an environment variable
1170 named "ver" is created by U-Boot showing the U-Boot
1171 version as printed by the "version" command.
1172 Any change to this variable will be reverted at the
1177 When CONFIG_CMD_DATE is selected, the type of the RTC
1178 has to be selected, too. Define exactly one of the
1181 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1182 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1183 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1184 CONFIG_RTC_MC146818 - use MC146818 RTC
1185 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1186 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1187 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1188 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1189 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1190 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1191 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1192 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1193 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1196 Note that if the RTC uses I2C, then the I2C interface
1197 must also be configured. See I2C Support, below.
1200 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1202 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1203 chip-ngpio pairs that tell the PCA953X driver the number of
1204 pins supported by a particular chip.
1206 Note that if the GPIO device uses I2C, then the I2C interface
1207 must also be configured. See I2C Support, below.
1210 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1211 accesses and can checksum them or write a list of them out
1212 to memory. See the 'iotrace' command for details. This is
1213 useful for testing device drivers since it can confirm that
1214 the driver behaves the same way before and after a code
1215 change. Currently this is supported on sandbox and arm. To
1216 add support for your architecture, add '#include <iotrace.h>'
1217 to the bottom of arch/<arch>/include/asm/io.h and test.
1219 Example output from the 'iotrace stats' command is below.
1220 Note that if the trace buffer is exhausted, the checksum will
1221 still continue to operate.
1224 Start: 10000000 (buffer start address)
1225 Size: 00010000 (buffer size)
1226 Offset: 00000120 (current buffer offset)
1227 Output: 10000120 (start + offset)
1228 Count: 00000018 (number of trace records)
1229 CRC32: 9526fb66 (CRC32 of all trace records)
1231 - Timestamp Support:
1233 When CONFIG_TIMESTAMP is selected, the timestamp
1234 (date and time) of an image is printed by image
1235 commands like bootm or iminfo. This option is
1236 automatically enabled when you select CONFIG_CMD_DATE .
1238 - Partition Labels (disklabels) Supported:
1239 Zero or more of the following:
1240 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1241 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1242 Intel architecture, USB sticks, etc.
1243 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1244 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1245 bootloader. Note 2TB partition limit; see
1247 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1249 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1250 CONFIG_CMD_SCSI) you must configure support for at
1251 least one non-MTD partition type as well.
1254 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1255 board configurations files but used nowhere!
1257 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1258 be performed by calling the function
1259 ide_set_reset(int reset)
1260 which has to be defined in a board specific file
1265 Set this to enable ATAPI support.
1270 Set this to enable support for disks larger than 137GB
1271 Also look at CONFIG_SYS_64BIT_LBA.
1272 Whithout these , LBA48 support uses 32bit variables and will 'only'
1273 support disks up to 2.1TB.
1275 CONFIG_SYS_64BIT_LBA:
1276 When enabled, makes the IDE subsystem use 64bit sector addresses.
1280 At the moment only there is only support for the
1281 SYM53C8XX SCSI controller; define
1282 CONFIG_SCSI_SYM53C8XX to enable it.
1284 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1285 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1286 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1287 maximum numbers of LUNs, SCSI ID's and target
1289 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1291 The environment variable 'scsidevs' is set to the number of
1292 SCSI devices found during the last scan.
1294 - NETWORK Support (PCI):
1296 Support for Intel 8254x/8257x gigabit chips.
1299 Utility code for direct access to the SPI bus on Intel 8257x.
1300 This does not do anything useful unless you set at least one
1301 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1303 CONFIG_E1000_SPI_GENERIC
1304 Allow generic access to the SPI bus on the Intel 8257x, for
1305 example with the "sspi" command.
1308 Management command for E1000 devices. When used on devices
1309 with SPI support you can reprogram the EEPROM from U-Boot.
1312 Support for Intel 82557/82559/82559ER chips.
1313 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1314 write routine for first time initialisation.
1317 Support for Digital 2114x chips.
1318 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1319 modem chip initialisation (KS8761/QS6611).
1322 Support for National dp83815 chips.
1325 Support for National dp8382[01] gigabit chips.
1327 - NETWORK Support (other):
1329 CONFIG_DRIVER_AT91EMAC
1330 Support for AT91RM9200 EMAC.
1333 Define this to use reduced MII inteface
1335 CONFIG_DRIVER_AT91EMAC_QUIET
1336 If this defined, the driver is quiet.
1337 The driver doen't show link status messages.
1339 CONFIG_CALXEDA_XGMAC
1340 Support for the Calxeda XGMAC device
1343 Support for SMSC's LAN91C96 chips.
1345 CONFIG_LAN91C96_BASE
1346 Define this to hold the physical address
1347 of the LAN91C96's I/O space
1349 CONFIG_LAN91C96_USE_32_BIT
1350 Define this to enable 32 bit addressing
1353 Support for SMSC's LAN91C111 chip
1355 CONFIG_SMC91111_BASE
1356 Define this to hold the physical address
1357 of the device (I/O space)
1359 CONFIG_SMC_USE_32_BIT
1360 Define this if data bus is 32 bits
1362 CONFIG_SMC_USE_IOFUNCS
1363 Define this to use i/o functions instead of macros
1364 (some hardware wont work with macros)
1366 CONFIG_DRIVER_TI_EMAC
1367 Support for davinci emac
1369 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1370 Define this if you have more then 3 PHYs.
1373 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1375 CONFIG_FTGMAC100_EGIGA
1376 Define this to use GE link update with gigabit PHY.
1377 Define this if FTGMAC100 is connected to gigabit PHY.
1378 If your system has 10/100 PHY only, it might not occur
1379 wrong behavior. Because PHY usually return timeout or
1380 useless data when polling gigabit status and gigabit
1381 control registers. This behavior won't affect the
1382 correctnessof 10/100 link speed update.
1385 Support for SMSC's LAN911x and LAN921x chips
1388 Define this to hold the physical address
1389 of the device (I/O space)
1391 CONFIG_SMC911X_32_BIT
1392 Define this if data bus is 32 bits
1394 CONFIG_SMC911X_16_BIT
1395 Define this if data bus is 16 bits. If your processor
1396 automatically converts one 32 bit word to two 16 bit
1397 words you may also try CONFIG_SMC911X_32_BIT.
1400 Support for Renesas on-chip Ethernet controller
1402 CONFIG_SH_ETHER_USE_PORT
1403 Define the number of ports to be used
1405 CONFIG_SH_ETHER_PHY_ADDR
1406 Define the ETH PHY's address
1408 CONFIG_SH_ETHER_CACHE_WRITEBACK
1409 If this option is set, the driver enables cache flush.
1413 Support for PWM modul on the imx6.
1417 Support TPM devices.
1419 CONFIG_TPM_TIS_INFINEON
1420 Support for Infineon i2c bus TPM devices. Only one device
1421 per system is supported at this time.
1423 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1424 Define the burst count bytes upper limit
1427 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1429 CONFIG_TPM_ST33ZP24_I2C
1430 Support for STMicroelectronics ST33ZP24 I2C devices.
1431 Requires TPM_ST33ZP24 and I2C.
1433 CONFIG_TPM_ATMEL_TWI
1434 Support for Atmel TWI TPM device. Requires I2C support.
1437 Support for generic parallel port TPM devices. Only one device
1438 per system is supported at this time.
1440 CONFIG_TPM_TIS_BASE_ADDRESS
1441 Base address where the generic TPM device is mapped
1442 to. Contemporary x86 systems usually map it at
1446 Add tpm monitor functions.
1447 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1448 provides monitor access to authorized functions.
1451 Define this to enable the TPM support library which provides
1452 functional interfaces to some TPM commands.
1453 Requires support for a TPM device.
1455 CONFIG_TPM_AUTH_SESSIONS
1456 Define this to enable authorized functions in the TPM library.
1457 Requires CONFIG_TPM and CONFIG_SHA1.
1460 At the moment only the UHCI host controller is
1461 supported (PIP405, MIP405, MPC5200); define
1462 CONFIG_USB_UHCI to enable it.
1463 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1464 and define CONFIG_USB_STORAGE to enable the USB
1467 Supported are USB Keyboards and USB Floppy drives
1469 MPC5200 USB requires additional defines:
1471 for 528 MHz Clock: 0x0001bbbb
1475 for differential drivers: 0x00001000
1476 for single ended drivers: 0x00005000
1477 for differential drivers on PSC3: 0x00000100
1478 for single ended drivers on PSC3: 0x00004100
1479 CONFIG_SYS_USB_EVENT_POLL
1480 May be defined to allow interrupt polling
1481 instead of using asynchronous interrupts
1483 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1484 txfilltuning field in the EHCI controller on reset.
1486 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1487 HW module registers.
1490 Define the below if you wish to use the USB console.
1491 Once firmware is rebuilt from a serial console issue the
1492 command "setenv stdin usbtty; setenv stdout usbtty" and
1493 attach your USB cable. The Unix command "dmesg" should print
1494 it has found a new device. The environment variable usbtty
1495 can be set to gserial or cdc_acm to enable your device to
1496 appear to a USB host as a Linux gserial device or a
1497 Common Device Class Abstract Control Model serial device.
1498 If you select usbtty = gserial you should be able to enumerate
1500 # modprobe usbserial vendor=0xVendorID product=0xProductID
1501 else if using cdc_acm, simply setting the environment
1502 variable usbtty to be cdc_acm should suffice. The following
1503 might be defined in YourBoardName.h
1506 Define this to build a UDC device
1509 Define this to have a tty type of device available to
1510 talk to the UDC device
1513 Define this to enable the high speed support for usb
1514 device and usbtty. If this feature is enabled, a routine
1515 int is_usbd_high_speed(void)
1516 also needs to be defined by the driver to dynamically poll
1517 whether the enumeration has succeded at high speed or full
1520 CONFIG_SYS_CONSOLE_IS_IN_ENV
1521 Define this if you want stdin, stdout &/or stderr to
1525 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1526 Derive USB clock from external clock "blah"
1527 - CONFIG_SYS_USB_EXTC_CLK 0x02
1529 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1530 Derive USB clock from brgclk
1531 - CONFIG_SYS_USB_BRG_CLK 0x04
1533 If you have a USB-IF assigned VendorID then you may wish to
1534 define your own vendor specific values either in BoardName.h
1535 or directly in usbd_vendor_info.h. If you don't define
1536 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1537 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1538 should pretend to be a Linux device to it's target host.
1540 CONFIG_USBD_MANUFACTURER
1541 Define this string as the name of your company for
1542 - CONFIG_USBD_MANUFACTURER "my company"
1544 CONFIG_USBD_PRODUCT_NAME
1545 Define this string as the name of your product
1546 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1548 CONFIG_USBD_VENDORID
1549 Define this as your assigned Vendor ID from the USB
1550 Implementors Forum. This *must* be a genuine Vendor ID
1551 to avoid polluting the USB namespace.
1552 - CONFIG_USBD_VENDORID 0xFFFF
1554 CONFIG_USBD_PRODUCTID
1555 Define this as the unique Product ID
1557 - CONFIG_USBD_PRODUCTID 0xFFFF
1559 - ULPI Layer Support:
1560 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1561 the generic ULPI layer. The generic layer accesses the ULPI PHY
1562 via the platform viewport, so you need both the genric layer and
1563 the viewport enabled. Currently only Chipidea/ARC based
1564 viewport is supported.
1565 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1566 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1567 If your ULPI phy needs a different reference clock than the
1568 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1569 the appropriate value in Hz.
1572 The MMC controller on the Intel PXA is supported. To
1573 enable this define CONFIG_MMC. The MMC can be
1574 accessed from the boot prompt by mapping the device
1575 to physical memory similar to flash. Command line is
1576 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1577 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1580 Support for Renesas on-chip MMCIF controller
1582 CONFIG_SH_MMCIF_ADDR
1583 Define the base address of MMCIF registers
1586 Define the clock frequency for MMCIF
1589 Enable the generic MMC driver
1591 CONFIG_SUPPORT_EMMC_BOOT
1592 Enable some additional features of the eMMC boot partitions.
1594 CONFIG_SUPPORT_EMMC_RPMB
1595 Enable the commands for reading, writing and programming the
1596 key for the Replay Protection Memory Block partition in eMMC.
1598 - USB Device Firmware Update (DFU) class support:
1599 CONFIG_USB_FUNCTION_DFU
1600 This enables the USB portion of the DFU USB class
1603 This enables the command "dfu" which is used to have
1604 U-Boot create a DFU class device via USB. This command
1605 requires that the "dfu_alt_info" environment variable be
1606 set and define the alt settings to expose to the host.
1609 This enables support for exposing (e)MMC devices via DFU.
1612 This enables support for exposing NAND devices via DFU.
1615 This enables support for exposing RAM via DFU.
1616 Note: DFU spec refer to non-volatile memory usage, but
1617 allow usages beyond the scope of spec - here RAM usage,
1618 one that would help mostly the developer.
1620 CONFIG_SYS_DFU_DATA_BUF_SIZE
1621 Dfu transfer uses a buffer before writing data to the
1622 raw storage device. Make the size (in bytes) of this buffer
1623 configurable. The size of this buffer is also configurable
1624 through the "dfu_bufsiz" environment variable.
1626 CONFIG_SYS_DFU_MAX_FILE_SIZE
1627 When updating files rather than the raw storage device,
1628 we use a static buffer to copy the file into and then write
1629 the buffer once we've been given the whole file. Define
1630 this to the maximum filesize (in bytes) for the buffer.
1631 Default is 4 MiB if undefined.
1633 DFU_DEFAULT_POLL_TIMEOUT
1634 Poll timeout [ms], is the timeout a device can send to the
1635 host. The host must wait for this timeout before sending
1636 a subsequent DFU_GET_STATUS request to the device.
1638 DFU_MANIFEST_POLL_TIMEOUT
1639 Poll timeout [ms], which the device sends to the host when
1640 entering dfuMANIFEST state. Host waits this timeout, before
1641 sending again an USB request to the device.
1643 - USB Device Android Fastboot support:
1644 CONFIG_USB_FUNCTION_FASTBOOT
1645 This enables the USB part of the fastboot gadget
1648 This enables the command "fastboot" which enables the Android
1649 fastboot mode for the platform's USB device. Fastboot is a USB
1650 protocol for downloading images, flashing and device control
1651 used on Android devices.
1652 See doc/README.android-fastboot for more information.
1654 CONFIG_ANDROID_BOOT_IMAGE
1655 This enables support for booting images which use the Android
1656 image format header.
1658 CONFIG_FASTBOOT_BUF_ADDR
1659 The fastboot protocol requires a large memory buffer for
1660 downloads. Define this to the starting RAM address to use for
1663 CONFIG_FASTBOOT_BUF_SIZE
1664 The fastboot protocol requires a large memory buffer for
1665 downloads. This buffer should be as large as possible for a
1666 platform. Define this to the size available RAM for fastboot.
1668 CONFIG_FASTBOOT_FLASH
1669 The fastboot protocol includes a "flash" command for writing
1670 the downloaded image to a non-volatile storage device. Define
1671 this to enable the "fastboot flash" command.
1673 CONFIG_FASTBOOT_FLASH_MMC_DEV
1674 The fastboot "flash" command requires additional information
1675 regarding the non-volatile storage device. Define this to
1676 the eMMC device that fastboot should use to store the image.
1678 CONFIG_FASTBOOT_GPT_NAME
1679 The fastboot "flash" command supports writing the downloaded
1680 image to the Protective MBR and the Primary GUID Partition
1681 Table. (Additionally, this downloaded image is post-processed
1682 to generate and write the Backup GUID Partition Table.)
1683 This occurs when the specified "partition name" on the
1684 "fastboot flash" command line matches this value.
1685 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1687 - Journaling Flash filesystem support:
1688 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1689 CONFIG_JFFS2_NAND_DEV
1690 Define these for a default partition on a NAND device
1692 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1693 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1694 Define these for a default partition on a NOR device
1696 CONFIG_SYS_JFFS_CUSTOM_PART
1697 Define this to create an own partition. You have to provide a
1698 function struct part_info* jffs2_part_info(int part_num)
1700 If you define only one JFFS2 partition you may also want to
1701 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1702 to disable the command chpart. This is the default when you
1703 have not defined a custom partition
1705 - FAT(File Allocation Table) filesystem write function support:
1708 Define this to enable support for saving memory data as a
1709 file in FAT formatted partition.
1711 This will also enable the command "fatwrite" enabling the
1712 user to write files to FAT.
1714 CBFS (Coreboot Filesystem) support
1717 Define this to enable support for reading from a Coreboot
1718 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1721 - FAT(File Allocation Table) filesystem cluster size:
1722 CONFIG_FS_FAT_MAX_CLUSTSIZE
1724 Define the max cluster size for fat operations else
1725 a default value of 65536 will be defined.
1728 See Kconfig help for available keyboard drivers.
1732 Define this to enable a custom keyboard support.
1733 This simply calls drv_keyboard_init() which must be
1734 defined in your board-specific files. This option is deprecated
1735 and is only used by novena. For new boards, use driver model
1741 Define this to enable video support (for output to
1744 CONFIG_VIDEO_CT69000
1746 Enable Chips & Technologies 69000 Video chip
1748 CONFIG_VIDEO_SMI_LYNXEM
1749 Enable Silicon Motion SMI 712/710/810 Video chip. The
1750 video output is selected via environment 'videoout'
1751 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1754 For the CT69000 and SMI_LYNXEM drivers, videomode is
1755 selected via environment 'videomode'. Two different ways
1757 - "videomode=num" 'num' is a standard LiLo mode numbers.
1758 Following standard modes are supported (* is default):
1760 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1761 -------------+---------------------------------------------
1762 8 bits | 0x301* 0x303 0x305 0x161 0x307
1763 15 bits | 0x310 0x313 0x316 0x162 0x319
1764 16 bits | 0x311 0x314 0x317 0x163 0x31A
1765 24 bits | 0x312 0x315 0x318 ? 0x31B
1766 -------------+---------------------------------------------
1767 (i.e. setenv videomode 317; saveenv; reset;)
1769 - "videomode=bootargs" all the video parameters are parsed
1770 from the bootargs. (See drivers/video/videomodes.c)
1773 CONFIG_VIDEO_SED13806
1774 Enable Epson SED13806 driver. This driver supports 8bpp
1775 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1776 or CONFIG_VIDEO_SED13806_16BPP
1779 Enable the Freescale DIU video driver. Reference boards for
1780 SOCs that have a DIU should define this macro to enable DIU
1781 support, and should also define these other macros:
1787 CONFIG_VIDEO_SW_CURSOR
1788 CONFIG_VGA_AS_SINGLE_DEVICE
1790 CONFIG_VIDEO_BMP_LOGO
1792 The DIU driver will look for the 'video-mode' environment
1793 variable, and if defined, enable the DIU as a console during
1794 boot. See the documentation file README.video for a
1795 description of this variable.
1797 - LCD Support: CONFIG_LCD
1799 Define this to enable LCD support (for output to LCD
1800 display); also select one of the supported displays
1801 by defining one of these:
1805 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1807 CONFIG_NEC_NL6448AC33:
1809 NEC NL6448AC33-18. Active, color, single scan.
1811 CONFIG_NEC_NL6448BC20
1813 NEC NL6448BC20-08. 6.5", 640x480.
1814 Active, color, single scan.
1816 CONFIG_NEC_NL6448BC33_54
1818 NEC NL6448BC33-54. 10.4", 640x480.
1819 Active, color, single scan.
1823 Sharp 320x240. Active, color, single scan.
1824 It isn't 16x9, and I am not sure what it is.
1826 CONFIG_SHARP_LQ64D341
1828 Sharp LQ64D341 display, 640x480.
1829 Active, color, single scan.
1833 HLD1045 display, 640x480.
1834 Active, color, single scan.
1838 Optrex CBL50840-2 NF-FW 99 22 M5
1840 Hitachi LMG6912RPFC-00T
1844 320x240. Black & white.
1846 Normally display is black on white background; define
1847 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1849 CONFIG_LCD_ALIGNMENT
1851 Normally the LCD is page-aligned (typically 4KB). If this is
1852 defined then the LCD will be aligned to this value instead.
1853 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1854 here, since it is cheaper to change data cache settings on
1855 a per-section basis.
1857 CONFIG_CONSOLE_SCROLL_LINES
1859 When the console need to be scrolled, this is the number of
1860 lines to scroll by. It defaults to 1. Increasing this makes
1861 the console jump but can help speed up operation when scrolling
1866 Sometimes, for example if the display is mounted in portrait
1867 mode or even if it's mounted landscape but rotated by 180degree,
1868 we need to rotate our content of the display relative to the
1869 framebuffer, so that user can read the messages which are
1871 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1872 initialized with a given rotation from "vl_rot" out of
1873 "vidinfo_t" which is provided by the board specific code.
1874 The value for vl_rot is coded as following (matching to
1875 fbcon=rotate:<n> linux-kernel commandline):
1876 0 = no rotation respectively 0 degree
1877 1 = 90 degree rotation
1878 2 = 180 degree rotation
1879 3 = 270 degree rotation
1881 If CONFIG_LCD_ROTATION is not defined, the console will be
1882 initialized with 0degree rotation.
1886 Support drawing of RLE8-compressed bitmaps on the LCD.
1890 Enables an 'i2c edid' command which can read EDID
1891 information over I2C from an attached LCD display.
1893 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1895 If this option is set, the environment is checked for
1896 a variable "splashimage". If found, the usual display
1897 of logo, copyright and system information on the LCD
1898 is suppressed and the BMP image at the address
1899 specified in "splashimage" is loaded instead. The
1900 console is redirected to the "nulldev", too. This
1901 allows for a "silent" boot where a splash screen is
1902 loaded very quickly after power-on.
1904 CONFIG_SPLASHIMAGE_GUARD
1906 If this option is set, then U-Boot will prevent the environment
1907 variable "splashimage" from being set to a problematic address
1908 (see README.displaying-bmps).
1909 This option is useful for targets where, due to alignment
1910 restrictions, an improperly aligned BMP image will cause a data
1911 abort. If you think you will not have problems with unaligned
1912 accesses (for example because your toolchain prevents them)
1913 there is no need to set this option.
1915 CONFIG_SPLASH_SCREEN_ALIGN
1917 If this option is set the splash image can be freely positioned
1918 on the screen. Environment variable "splashpos" specifies the
1919 position as "x,y". If a positive number is given it is used as
1920 number of pixel from left/top. If a negative number is given it
1921 is used as number of pixel from right/bottom. You can also
1922 specify 'm' for centering the image.
1925 setenv splashpos m,m
1926 => image at center of screen
1928 setenv splashpos 30,20
1929 => image at x = 30 and y = 20
1931 setenv splashpos -10,m
1932 => vertically centered image
1933 at x = dspWidth - bmpWidth - 9
1935 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1937 If this option is set, additionally to standard BMP
1938 images, gzipped BMP images can be displayed via the
1939 splashscreen support or the bmp command.
1941 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1943 If this option is set, 8-bit RLE compressed BMP images
1944 can be displayed via the splashscreen support or the
1947 - Do compressing for memory range:
1950 If this option is set, it would use zlib deflate method
1951 to compress the specified memory at its best effort.
1953 - Compression support:
1956 Enabled by default to support gzip compressed images.
1960 If this option is set, support for bzip2 compressed
1961 images is included. If not, only uncompressed and gzip
1962 compressed images are supported.
1964 NOTE: the bzip2 algorithm requires a lot of RAM, so
1965 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1970 If this option is set, support for lzma compressed
1973 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1974 requires an amount of dynamic memory that is given by the
1977 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1979 Where lc and lp stand for, respectively, Literal context bits
1980 and Literal pos bits.
1982 This value is upper-bounded by 14MB in the worst case. Anyway,
1983 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1984 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1985 a very small buffer.
1987 Use the lzmainfo tool to determinate the lc and lp values and
1988 then calculate the amount of needed dynamic memory (ensuring
1989 the appropriate CONFIG_SYS_MALLOC_LEN value).
1993 If this option is set, support for LZO compressed images
1999 The address of PHY on MII bus.
2001 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2003 The clock frequency of the MII bus
2007 If this option is set, support for speed/duplex
2008 detection of gigabit PHY is included.
2010 CONFIG_PHY_RESET_DELAY
2012 Some PHY like Intel LXT971A need extra delay after
2013 reset before any MII register access is possible.
2014 For such PHY, set this option to the usec delay
2015 required. (minimum 300usec for LXT971A)
2017 CONFIG_PHY_CMD_DELAY (ppc4xx)
2019 Some PHY like Intel LXT971A need extra delay after
2020 command issued before MII status register can be read
2025 Define a default value for the IP address to use for
2026 the default Ethernet interface, in case this is not
2027 determined through e.g. bootp.
2028 (Environment variable "ipaddr")
2030 - Server IP address:
2033 Defines a default value for the IP address of a TFTP
2034 server to contact when using the "tftboot" command.
2035 (Environment variable "serverip")
2037 CONFIG_KEEP_SERVERADDR
2039 Keeps the server's MAC address, in the env 'serveraddr'
2040 for passing to bootargs (like Linux's netconsole option)
2042 - Gateway IP address:
2045 Defines a default value for the IP address of the
2046 default router where packets to other networks are
2048 (Environment variable "gatewayip")
2053 Defines a default value for the subnet mask (or
2054 routing prefix) which is used to determine if an IP
2055 address belongs to the local subnet or needs to be
2056 forwarded through a router.
2057 (Environment variable "netmask")
2059 - Multicast TFTP Mode:
2062 Defines whether you want to support multicast TFTP as per
2063 rfc-2090; for example to work with atftp. Lets lots of targets
2064 tftp down the same boot image concurrently. Note: the Ethernet
2065 driver in use must provide a function: mcast() to join/leave a
2068 - BOOTP Recovery Mode:
2069 CONFIG_BOOTP_RANDOM_DELAY
2071 If you have many targets in a network that try to
2072 boot using BOOTP, you may want to avoid that all
2073 systems send out BOOTP requests at precisely the same
2074 moment (which would happen for instance at recovery
2075 from a power failure, when all systems will try to
2076 boot, thus flooding the BOOTP server. Defining
2077 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2078 inserted before sending out BOOTP requests. The
2079 following delays are inserted then:
2081 1st BOOTP request: delay 0 ... 1 sec
2082 2nd BOOTP request: delay 0 ... 2 sec
2083 3rd BOOTP request: delay 0 ... 4 sec
2085 BOOTP requests: delay 0 ... 8 sec
2087 CONFIG_BOOTP_ID_CACHE_SIZE
2089 BOOTP packets are uniquely identified using a 32-bit ID. The
2090 server will copy the ID from client requests to responses and
2091 U-Boot will use this to determine if it is the destination of
2092 an incoming response. Some servers will check that addresses
2093 aren't in use before handing them out (usually using an ARP
2094 ping) and therefore take up to a few hundred milliseconds to
2095 respond. Network congestion may also influence the time it
2096 takes for a response to make it back to the client. If that
2097 time is too long, U-Boot will retransmit requests. In order
2098 to allow earlier responses to still be accepted after these
2099 retransmissions, U-Boot's BOOTP client keeps a small cache of
2100 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2101 cache. The default is to keep IDs for up to four outstanding
2102 requests. Increasing this will allow U-Boot to accept offers
2103 from a BOOTP client in networks with unusually high latency.
2105 - DHCP Advanced Options:
2106 You can fine tune the DHCP functionality by defining
2107 CONFIG_BOOTP_* symbols:
2109 CONFIG_BOOTP_SUBNETMASK
2110 CONFIG_BOOTP_GATEWAY
2111 CONFIG_BOOTP_HOSTNAME
2112 CONFIG_BOOTP_NISDOMAIN
2113 CONFIG_BOOTP_BOOTPATH
2114 CONFIG_BOOTP_BOOTFILESIZE
2117 CONFIG_BOOTP_SEND_HOSTNAME
2118 CONFIG_BOOTP_NTPSERVER
2119 CONFIG_BOOTP_TIMEOFFSET
2120 CONFIG_BOOTP_VENDOREX
2121 CONFIG_BOOTP_MAY_FAIL
2123 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2124 environment variable, not the BOOTP server.
2126 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2127 after the configured retry count, the call will fail
2128 instead of starting over. This can be used to fail over
2129 to Link-local IP address configuration if the DHCP server
2132 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2133 serverip from a DHCP server, it is possible that more
2134 than one DNS serverip is offered to the client.
2135 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2136 serverip will be stored in the additional environment
2137 variable "dnsip2". The first DNS serverip is always
2138 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2141 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2142 to do a dynamic update of a DNS server. To do this, they
2143 need the hostname of the DHCP requester.
2144 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2145 of the "hostname" environment variable is passed as
2146 option 12 to the DHCP server.
2148 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2150 A 32bit value in microseconds for a delay between
2151 receiving a "DHCP Offer" and sending the "DHCP Request".
2152 This fixes a problem with certain DHCP servers that don't
2153 respond 100% of the time to a "DHCP request". E.g. On an
2154 AT91RM9200 processor running at 180MHz, this delay needed
2155 to be *at least* 15,000 usec before a Windows Server 2003
2156 DHCP server would reply 100% of the time. I recommend at
2157 least 50,000 usec to be safe. The alternative is to hope
2158 that one of the retries will be successful but note that
2159 the DHCP timeout and retry process takes a longer than
2162 - Link-local IP address negotiation:
2163 Negotiate with other link-local clients on the local network
2164 for an address that doesn't require explicit configuration.
2165 This is especially useful if a DHCP server cannot be guaranteed
2166 to exist in all environments that the device must operate.
2168 See doc/README.link-local for more information.
2171 CONFIG_CDP_DEVICE_ID
2173 The device id used in CDP trigger frames.
2175 CONFIG_CDP_DEVICE_ID_PREFIX
2177 A two character string which is prefixed to the MAC address
2182 A printf format string which contains the ascii name of
2183 the port. Normally is set to "eth%d" which sets
2184 eth0 for the first Ethernet, eth1 for the second etc.
2186 CONFIG_CDP_CAPABILITIES
2188 A 32bit integer which indicates the device capabilities;
2189 0x00000010 for a normal host which does not forwards.
2193 An ascii string containing the version of the software.
2197 An ascii string containing the name of the platform.
2201 A 32bit integer sent on the trigger.
2203 CONFIG_CDP_POWER_CONSUMPTION
2205 A 16bit integer containing the power consumption of the
2206 device in .1 of milliwatts.
2208 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2210 A byte containing the id of the VLAN.
2212 - Status LED: CONFIG_STATUS_LED
2214 Several configurations allow to display the current
2215 status using a LED. For instance, the LED will blink
2216 fast while running U-Boot code, stop blinking as
2217 soon as a reply to a BOOTP request was received, and
2218 start blinking slow once the Linux kernel is running
2219 (supported by a status LED driver in the Linux
2220 kernel). Defining CONFIG_STATUS_LED enables this
2226 The status LED can be connected to a GPIO pin.
2227 In such cases, the gpio_led driver can be used as a
2228 status LED backend implementation. Define CONFIG_GPIO_LED
2229 to include the gpio_led driver in the U-Boot binary.
2231 CONFIG_GPIO_LED_INVERTED_TABLE
2232 Some GPIO connected LEDs may have inverted polarity in which
2233 case the GPIO high value corresponds to LED off state and
2234 GPIO low value corresponds to LED on state.
2235 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2236 with a list of GPIO LEDs that have inverted polarity.
2238 - CAN Support: CONFIG_CAN_DRIVER
2240 Defining CONFIG_CAN_DRIVER enables CAN driver support
2241 on those systems that support this (optional)
2242 feature, like the TQM8xxL modules.
2244 - I2C Support: CONFIG_SYS_I2C
2246 This enable the NEW i2c subsystem, and will allow you to use
2247 i2c commands at the u-boot command line (as long as you set
2248 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2249 based realtime clock chips or other i2c devices. See
2250 common/cmd_i2c.c for a description of the command line
2253 ported i2c driver to the new framework:
2254 - drivers/i2c/soft_i2c.c:
2255 - activate first bus with CONFIG_SYS_I2C_SOFT define
2256 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2257 for defining speed and slave address
2258 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2259 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2260 for defining speed and slave address
2261 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2262 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2263 for defining speed and slave address
2264 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2265 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2266 for defining speed and slave address
2268 - drivers/i2c/fsl_i2c.c:
2269 - activate i2c driver with CONFIG_SYS_I2C_FSL
2270 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2271 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2272 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2274 - If your board supports a second fsl i2c bus, define
2275 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2276 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2277 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2280 - drivers/i2c/tegra_i2c.c:
2281 - activate this driver with CONFIG_SYS_I2C_TEGRA
2282 - This driver adds 4 i2c buses with a fix speed from
2283 100000 and the slave addr 0!
2285 - drivers/i2c/ppc4xx_i2c.c
2286 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2287 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2288 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2290 - drivers/i2c/i2c_mxc.c
2291 - activate this driver with CONFIG_SYS_I2C_MXC
2292 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2293 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2294 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2295 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2296 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2297 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2298 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2299 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2300 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2301 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2302 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2303 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2304 If those defines are not set, default value is 100000
2305 for speed, and 0 for slave.
2307 - drivers/i2c/rcar_i2c.c:
2308 - activate this driver with CONFIG_SYS_I2C_RCAR
2309 - This driver adds 4 i2c buses
2311 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2312 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2313 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2314 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2315 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2316 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2317 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2318 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2319 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2321 - drivers/i2c/sh_i2c.c:
2322 - activate this driver with CONFIG_SYS_I2C_SH
2323 - This driver adds from 2 to 5 i2c buses
2325 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2326 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2327 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2328 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2329 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2330 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2331 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2332 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2333 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2334 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2335 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2336 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2337 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2339 - drivers/i2c/omap24xx_i2c.c
2340 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2341 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2342 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2343 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2344 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2345 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2346 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2347 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2348 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2349 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2350 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2352 - drivers/i2c/zynq_i2c.c
2353 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2354 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2355 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2357 - drivers/i2c/s3c24x0_i2c.c:
2358 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2359 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2360 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2361 with a fix speed from 100000 and the slave addr 0!
2363 - drivers/i2c/ihs_i2c.c
2364 - activate this driver with CONFIG_SYS_I2C_IHS
2365 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2366 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2367 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2368 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2369 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2370 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2371 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2372 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2373 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2374 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2375 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2376 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2377 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2378 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2379 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2380 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2381 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2382 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2383 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2384 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2385 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2389 CONFIG_SYS_NUM_I2C_BUSES
2390 Hold the number of i2c buses you want to use. If you
2391 don't use/have i2c muxes on your i2c bus, this
2392 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2395 CONFIG_SYS_I2C_DIRECT_BUS
2396 define this, if you don't use i2c muxes on your hardware.
2397 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2400 CONFIG_SYS_I2C_MAX_HOPS
2401 define how many muxes are maximal consecutively connected
2402 on one i2c bus. If you not use i2c muxes, omit this
2405 CONFIG_SYS_I2C_BUSES
2406 hold a list of buses you want to use, only used if
2407 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2408 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2409 CONFIG_SYS_NUM_I2C_BUSES = 9:
2411 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2412 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2413 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2414 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2415 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2416 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2417 {1, {I2C_NULL_HOP}}, \
2418 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2419 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2423 bus 0 on adapter 0 without a mux
2424 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2425 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2426 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2427 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2428 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2429 bus 6 on adapter 1 without a mux
2430 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2431 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2433 If you do not have i2c muxes on your board, omit this define.
2435 - Legacy I2C Support: CONFIG_HARD_I2C
2437 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2438 provides the following compelling advantages:
2440 - more than one i2c adapter is usable
2441 - approved multibus support
2442 - better i2c mux support
2444 ** Please consider updating your I2C driver now. **
2446 These enable legacy I2C serial bus commands. Defining
2447 CONFIG_HARD_I2C will include the appropriate I2C driver
2448 for the selected CPU.
2450 This will allow you to use i2c commands at the u-boot
2451 command line (as long as you set CONFIG_CMD_I2C in
2452 CONFIG_COMMANDS) and communicate with i2c based realtime
2453 clock chips. See common/cmd_i2c.c for a description of the
2454 command line interface.
2456 CONFIG_HARD_I2C selects a hardware I2C controller.
2458 There are several other quantities that must also be
2459 defined when you define CONFIG_HARD_I2C.
2461 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2462 to be the frequency (in Hz) at which you wish your i2c bus
2463 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2464 the CPU's i2c node address).
2466 Now, the u-boot i2c code for the mpc8xx
2467 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2468 and so its address should therefore be cleared to 0 (See,
2469 eg, MPC823e User's Manual p.16-473). So, set
2470 CONFIG_SYS_I2C_SLAVE to 0.
2472 CONFIG_SYS_I2C_INIT_MPC5XXX
2474 When a board is reset during an i2c bus transfer
2475 chips might think that the current transfer is still
2476 in progress. Reset the slave devices by sending start
2477 commands until the slave device responds.
2479 That's all that's required for CONFIG_HARD_I2C.
2481 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2482 then the following macros need to be defined (examples are
2483 from include/configs/lwmon.h):
2487 (Optional). Any commands necessary to enable the I2C
2488 controller or configure ports.
2490 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2494 (Only for MPC8260 CPU). The I/O port to use (the code
2495 assumes both bits are on the same port). Valid values
2496 are 0..3 for ports A..D.
2500 The code necessary to make the I2C data line active
2501 (driven). If the data line is open collector, this
2504 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2508 The code necessary to make the I2C data line tri-stated
2509 (inactive). If the data line is open collector, this
2512 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2516 Code that returns true if the I2C data line is high,
2519 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2523 If <bit> is true, sets the I2C data line high. If it
2524 is false, it clears it (low).
2526 eg: #define I2C_SDA(bit) \
2527 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2528 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2532 If <bit> is true, sets the I2C clock line high. If it
2533 is false, it clears it (low).
2535 eg: #define I2C_SCL(bit) \
2536 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2537 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2541 This delay is invoked four times per clock cycle so this
2542 controls the rate of data transfer. The data rate thus
2543 is 1 / (I2C_DELAY * 4). Often defined to be something
2546 #define I2C_DELAY udelay(2)
2548 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2550 If your arch supports the generic GPIO framework (asm/gpio.h),
2551 then you may alternatively define the two GPIOs that are to be
2552 used as SCL / SDA. Any of the previous I2C_xxx macros will
2553 have GPIO-based defaults assigned to them as appropriate.
2555 You should define these to the GPIO value as given directly to
2556 the generic GPIO functions.
2558 CONFIG_SYS_I2C_INIT_BOARD
2560 When a board is reset during an i2c bus transfer
2561 chips might think that the current transfer is still
2562 in progress. On some boards it is possible to access
2563 the i2c SCLK line directly, either by using the
2564 processor pin as a GPIO or by having a second pin
2565 connected to the bus. If this option is defined a
2566 custom i2c_init_board() routine in boards/xxx/board.c
2567 is run early in the boot sequence.
2569 CONFIG_SYS_I2C_BOARD_LATE_INIT
2571 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2572 defined a custom i2c_board_late_init() routine in
2573 boards/xxx/board.c is run AFTER the operations in i2c_init()
2574 is completed. This callpoint can be used to unreset i2c bus
2575 using CPU i2c controller register accesses for CPUs whose i2c
2576 controller provide such a method. It is called at the end of
2577 i2c_init() to allow i2c_init operations to setup the i2c bus
2578 controller on the CPU (e.g. setting bus speed & slave address).
2580 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2582 This option enables configuration of bi_iic_fast[] flags
2583 in u-boot bd_info structure based on u-boot environment
2584 variable "i2cfast". (see also i2cfast)
2586 CONFIG_I2C_MULTI_BUS
2588 This option allows the use of multiple I2C buses, each of which
2589 must have a controller. At any point in time, only one bus is
2590 active. To switch to a different bus, use the 'i2c dev' command.
2591 Note that bus numbering is zero-based.
2593 CONFIG_SYS_I2C_NOPROBES
2595 This option specifies a list of I2C devices that will be skipped
2596 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2597 is set, specify a list of bus-device pairs. Otherwise, specify
2598 a 1D array of device addresses
2601 #undef CONFIG_I2C_MULTI_BUS
2602 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2604 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2606 #define CONFIG_I2C_MULTI_BUS
2607 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2609 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2611 CONFIG_SYS_SPD_BUS_NUM
2613 If defined, then this indicates the I2C bus number for DDR SPD.
2614 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2616 CONFIG_SYS_RTC_BUS_NUM
2618 If defined, then this indicates the I2C bus number for the RTC.
2619 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2621 CONFIG_SYS_DTT_BUS_NUM
2623 If defined, then this indicates the I2C bus number for the DTT.
2624 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2626 CONFIG_SYS_I2C_DTT_ADDR:
2628 If defined, specifies the I2C address of the DTT device.
2629 If not defined, then U-Boot uses predefined value for
2630 specified DTT device.
2632 CONFIG_SOFT_I2C_READ_REPEATED_START
2634 defining this will force the i2c_read() function in
2635 the soft_i2c driver to perform an I2C repeated start
2636 between writing the address pointer and reading the
2637 data. If this define is omitted the default behaviour
2638 of doing a stop-start sequence will be used. Most I2C
2639 devices can use either method, but some require one or
2642 - SPI Support: CONFIG_SPI
2644 Enables SPI driver (so far only tested with
2645 SPI EEPROM, also an instance works with Crystal A/D and
2646 D/As on the SACSng board)
2650 Enables the driver for SPI controller on SuperH. Currently
2651 only SH7757 is supported.
2655 Enables a software (bit-bang) SPI driver rather than
2656 using hardware support. This is a general purpose
2657 driver that only requires three general I/O port pins
2658 (two outputs, one input) to function. If this is
2659 defined, the board configuration must define several
2660 SPI configuration items (port pins to use, etc). For
2661 an example, see include/configs/sacsng.h.
2665 Enables a hardware SPI driver for general-purpose reads
2666 and writes. As with CONFIG_SOFT_SPI, the board configuration
2667 must define a list of chip-select function pointers.
2668 Currently supported on some MPC8xxx processors. For an
2669 example, see include/configs/mpc8349emds.h.
2673 Enables the driver for the SPI controllers on i.MX and MXC
2674 SoCs. Currently i.MX31/35/51 are supported.
2676 CONFIG_SYS_SPI_MXC_WAIT
2677 Timeout for waiting until spi transfer completed.
2678 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2680 - FPGA Support: CONFIG_FPGA
2682 Enables FPGA subsystem.
2684 CONFIG_FPGA_<vendor>
2686 Enables support for specific chip vendors.
2689 CONFIG_FPGA_<family>
2691 Enables support for FPGA family.
2692 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2696 Specify the number of FPGA devices to support.
2698 CONFIG_CMD_FPGA_LOADMK
2700 Enable support for fpga loadmk command
2702 CONFIG_CMD_FPGA_LOADP
2704 Enable support for fpga loadp command - load partial bitstream
2706 CONFIG_CMD_FPGA_LOADBP
2708 Enable support for fpga loadbp command - load partial bitstream
2711 CONFIG_SYS_FPGA_PROG_FEEDBACK
2713 Enable printing of hash marks during FPGA configuration.
2715 CONFIG_SYS_FPGA_CHECK_BUSY
2717 Enable checks on FPGA configuration interface busy
2718 status by the configuration function. This option
2719 will require a board or device specific function to
2724 If defined, a function that provides delays in the FPGA
2725 configuration driver.
2727 CONFIG_SYS_FPGA_CHECK_CTRLC
2728 Allow Control-C to interrupt FPGA configuration
2730 CONFIG_SYS_FPGA_CHECK_ERROR
2732 Check for configuration errors during FPGA bitfile
2733 loading. For example, abort during Virtex II
2734 configuration if the INIT_B line goes low (which
2735 indicated a CRC error).
2737 CONFIG_SYS_FPGA_WAIT_INIT
2739 Maximum time to wait for the INIT_B line to de-assert
2740 after PROB_B has been de-asserted during a Virtex II
2741 FPGA configuration sequence. The default time is 500
2744 CONFIG_SYS_FPGA_WAIT_BUSY
2746 Maximum time to wait for BUSY to de-assert during
2747 Virtex II FPGA configuration. The default is 5 ms.
2749 CONFIG_SYS_FPGA_WAIT_CONFIG
2751 Time to wait after FPGA configuration. The default is
2754 - Configuration Management:
2757 Some SoCs need special image types (e.g. U-Boot binary
2758 with a special header) as build targets. By defining
2759 CONFIG_BUILD_TARGET in the SoC / board header, this
2760 special image will be automatically built upon calling
2765 If defined, this string will be added to the U-Boot
2766 version information (U_BOOT_VERSION)
2768 - Vendor Parameter Protection:
2770 U-Boot considers the values of the environment
2771 variables "serial#" (Board Serial Number) and
2772 "ethaddr" (Ethernet Address) to be parameters that
2773 are set once by the board vendor / manufacturer, and
2774 protects these variables from casual modification by
2775 the user. Once set, these variables are read-only,
2776 and write or delete attempts are rejected. You can
2777 change this behaviour:
2779 If CONFIG_ENV_OVERWRITE is #defined in your config
2780 file, the write protection for vendor parameters is
2781 completely disabled. Anybody can change or delete
2784 Alternatively, if you define _both_ an ethaddr in the
2785 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2786 Ethernet address is installed in the environment,
2787 which can be changed exactly ONCE by the user. [The
2788 serial# is unaffected by this, i. e. it remains
2791 The same can be accomplished in a more flexible way
2792 for any variable by configuring the type of access
2793 to allow for those variables in the ".flags" variable
2794 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2799 Define this variable to enable the reservation of
2800 "protected RAM", i. e. RAM which is not overwritten
2801 by U-Boot. Define CONFIG_PRAM to hold the number of
2802 kB you want to reserve for pRAM. You can overwrite
2803 this default value by defining an environment
2804 variable "pram" to the number of kB you want to
2805 reserve. Note that the board info structure will
2806 still show the full amount of RAM. If pRAM is
2807 reserved, a new environment variable "mem" will
2808 automatically be defined to hold the amount of
2809 remaining RAM in a form that can be passed as boot
2810 argument to Linux, for instance like that:
2812 setenv bootargs ... mem=\${mem}
2815 This way you can tell Linux not to use this memory,
2816 either, which results in a memory region that will
2817 not be affected by reboots.
2819 *WARNING* If your board configuration uses automatic
2820 detection of the RAM size, you must make sure that
2821 this memory test is non-destructive. So far, the
2822 following board configurations are known to be
2825 IVMS8, IVML24, SPD8xx, TQM8xxL,
2826 HERMES, IP860, RPXlite, LWMON,
2829 - Access to physical memory region (> 4GB)
2830 Some basic support is provided for operations on memory not
2831 normally accessible to U-Boot - e.g. some architectures
2832 support access to more than 4GB of memory on 32-bit
2833 machines using physical address extension or similar.
2834 Define CONFIG_PHYSMEM to access this basic support, which
2835 currently only supports clearing the memory.
2840 Define this variable to stop the system in case of a
2841 fatal error, so that you have to reset it manually.
2842 This is probably NOT a good idea for an embedded
2843 system where you want the system to reboot
2844 automatically as fast as possible, but it may be
2845 useful during development since you can try to debug
2846 the conditions that lead to the situation.
2848 CONFIG_NET_RETRY_COUNT
2850 This variable defines the number of retries for
2851 network operations like ARP, RARP, TFTP, or BOOTP
2852 before giving up the operation. If not defined, a
2853 default value of 5 is used.
2857 Timeout waiting for an ARP reply in milliseconds.
2861 Timeout in milliseconds used in NFS protocol.
2862 If you encounter "ERROR: Cannot umount" in nfs command,
2863 try longer timeout such as
2864 #define CONFIG_NFS_TIMEOUT 10000UL
2866 - Command Interpreter:
2867 CONFIG_AUTO_COMPLETE
2869 Enable auto completion of commands using TAB.
2871 CONFIG_SYS_PROMPT_HUSH_PS2
2873 This defines the secondary prompt string, which is
2874 printed when the command interpreter needs more input
2875 to complete a command. Usually "> ".
2879 In the current implementation, the local variables
2880 space and global environment variables space are
2881 separated. Local variables are those you define by
2882 simply typing `name=value'. To access a local
2883 variable later on, you have write `$name' or
2884 `${name}'; to execute the contents of a variable
2885 directly type `$name' at the command prompt.
2887 Global environment variables are those you use
2888 setenv/printenv to work with. To run a command stored
2889 in such a variable, you need to use the run command,
2890 and you must not use the '$' sign to access them.
2892 To store commands and special characters in a
2893 variable, please use double quotation marks
2894 surrounding the whole text of the variable, instead
2895 of the backslashes before semicolons and special
2898 - Command Line Editing and History:
2899 CONFIG_CMDLINE_EDITING
2901 Enable editing and History functions for interactive
2902 command line input operations
2904 - Default Environment:
2905 CONFIG_EXTRA_ENV_SETTINGS
2907 Define this to contain any number of null terminated
2908 strings (variable = value pairs) that will be part of
2909 the default environment compiled into the boot image.
2911 For example, place something like this in your
2912 board's config file:
2914 #define CONFIG_EXTRA_ENV_SETTINGS \
2918 Warning: This method is based on knowledge about the
2919 internal format how the environment is stored by the
2920 U-Boot code. This is NOT an official, exported
2921 interface! Although it is unlikely that this format
2922 will change soon, there is no guarantee either.
2923 You better know what you are doing here.
2925 Note: overly (ab)use of the default environment is
2926 discouraged. Make sure to check other ways to preset
2927 the environment like the "source" command or the
2930 CONFIG_ENV_VARS_UBOOT_CONFIG
2932 Define this in order to add variables describing the
2933 U-Boot build configuration to the default environment.
2934 These will be named arch, cpu, board, vendor, and soc.
2936 Enabling this option will cause the following to be defined:
2944 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2946 Define this in order to add variables describing certain
2947 run-time determined information about the hardware to the
2948 environment. These will be named board_name, board_rev.
2950 CONFIG_DELAY_ENVIRONMENT
2952 Normally the environment is loaded when the board is
2953 initialised so that it is available to U-Boot. This inhibits
2954 that so that the environment is not available until
2955 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2956 this is instead controlled by the value of
2957 /config/load-environment.
2959 - Parallel Flash support:
2962 Traditionally U-boot was run on systems with parallel NOR
2963 flash. This option is used to disable support for parallel NOR
2964 flash. This option should be defined if the board does not have
2967 If this option is not defined one of the generic flash drivers
2968 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2969 selected or the board must provide an implementation of the
2970 flash API (see include/flash.h).
2972 - DataFlash Support:
2973 CONFIG_HAS_DATAFLASH
2975 Defining this option enables DataFlash features and
2976 allows to read/write in Dataflash via the standard
2979 - Serial Flash support
2982 Defining this option enables SPI flash commands
2983 'sf probe/read/write/erase/update'.
2985 Usage requires an initial 'probe' to define the serial
2986 flash parameters, followed by read/write/erase/update
2989 The following defaults may be provided by the platform
2990 to handle the common case when only a single serial
2991 flash is present on the system.
2993 CONFIG_SF_DEFAULT_BUS Bus identifier
2994 CONFIG_SF_DEFAULT_CS Chip-select
2995 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2996 CONFIG_SF_DEFAULT_SPEED in Hz
3000 Define this option to include a destructive SPI flash
3003 CONFIG_SF_DUAL_FLASH Dual flash memories
3005 Define this option to use dual flash support where two flash
3006 memories can be connected with a given cs line.
3007 Currently Xilinx Zynq qspi supports these type of connections.
3009 - SystemACE Support:
3012 Adding this option adds support for Xilinx SystemACE
3013 chips attached via some sort of local bus. The address
3014 of the chip must also be defined in the
3015 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3017 #define CONFIG_SYSTEMACE
3018 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3020 When SystemACE support is added, the "ace" device type
3021 becomes available to the fat commands, i.e. fatls.
3023 - TFTP Fixed UDP Port:
3026 If this is defined, the environment variable tftpsrcp
3027 is used to supply the TFTP UDP source port value.
3028 If tftpsrcp isn't defined, the normal pseudo-random port
3029 number generator is used.
3031 Also, the environment variable tftpdstp is used to supply
3032 the TFTP UDP destination port value. If tftpdstp isn't
3033 defined, the normal port 69 is used.
3035 The purpose for tftpsrcp is to allow a TFTP server to
3036 blindly start the TFTP transfer using the pre-configured
3037 target IP address and UDP port. This has the effect of
3038 "punching through" the (Windows XP) firewall, allowing
3039 the remainder of the TFTP transfer to proceed normally.
3040 A better solution is to properly configure the firewall,
3041 but sometimes that is not allowed.
3046 This enables a generic 'hash' command which can produce
3047 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3051 Enable the hash verify command (hash -v). This adds to code
3054 CONFIG_SHA1 - This option enables support of hashing using SHA1
3055 algorithm. The hash is calculated in software.
3056 CONFIG_SHA256 - This option enables support of hashing using
3057 SHA256 algorithm. The hash is calculated in software.
3058 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3059 for SHA1/SHA256 hashing.
3060 This affects the 'hash' command and also the
3061 hash_lookup_algo() function.
3062 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3063 hardware-acceleration for SHA1/SHA256 progressive hashing.
3064 Data can be streamed in a block at a time and the hashing
3065 is performed in hardware.
3067 Note: There is also a sha1sum command, which should perhaps
3068 be deprecated in favour of 'hash sha1'.
3070 - Freescale i.MX specific commands:
3071 CONFIG_CMD_HDMIDETECT
3072 This enables 'hdmidet' command which returns true if an
3073 HDMI monitor is detected. This command is i.MX 6 specific.
3076 This enables the 'bmode' (bootmode) command for forcing
3077 a boot from specific media.
3079 This is useful for forcing the ROM's usb downloader to
3080 activate upon a watchdog reset which is nice when iterating
3081 on U-Boot. Using the reset button or running bmode normal
3082 will set it back to normal. This command currently
3083 supports i.MX53 and i.MX6.
3088 This enables the RSA algorithm used for FIT image verification
3089 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3091 The Modular Exponentiation algorithm in RSA is implemented using
3092 driver model. So CONFIG_DM needs to be enabled by default for this
3093 library to function.
3095 The signing part is build into mkimage regardless of this
3096 option. The software based modular exponentiation is built into
3097 mkimage irrespective of this option.
3099 - bootcount support:
3100 CONFIG_BOOTCOUNT_LIMIT
3102 This enables the bootcounter support, see:
3103 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3106 enable special bootcounter support on at91sam9xe based boards.
3108 enable special bootcounter support on blackfin based boards.
3110 enable special bootcounter support on da850 based boards.
3111 CONFIG_BOOTCOUNT_RAM
3112 enable support for the bootcounter in RAM
3113 CONFIG_BOOTCOUNT_I2C
3114 enable support for the bootcounter on an i2c (like RTC) device.
3115 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3116 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3118 CONFIG_BOOTCOUNT_ALEN = address len
3120 - Show boot progress:
3121 CONFIG_SHOW_BOOT_PROGRESS
3123 Defining this option allows to add some board-
3124 specific code (calling a user-provided function
3125 "show_boot_progress(int)") that enables you to show
3126 the system's boot progress on some display (for
3127 example, some LED's) on your board. At the moment,
3128 the following checkpoints are implemented:
3131 Legacy uImage format:
3134 1 common/cmd_bootm.c before attempting to boot an image
3135 -1 common/cmd_bootm.c Image header has bad magic number
3136 2 common/cmd_bootm.c Image header has correct magic number
3137 -2 common/cmd_bootm.c Image header has bad checksum
3138 3 common/cmd_bootm.c Image header has correct checksum
3139 -3 common/cmd_bootm.c Image data has bad checksum
3140 4 common/cmd_bootm.c Image data has correct checksum
3141 -4 common/cmd_bootm.c Image is for unsupported architecture
3142 5 common/cmd_bootm.c Architecture check OK
3143 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3144 6 common/cmd_bootm.c Image Type check OK
3145 -6 common/cmd_bootm.c gunzip uncompression error
3146 -7 common/cmd_bootm.c Unimplemented compression type
3147 7 common/cmd_bootm.c Uncompression OK
3148 8 common/cmd_bootm.c No uncompress/copy overwrite error
3149 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3151 9 common/image.c Start initial ramdisk verification
3152 -10 common/image.c Ramdisk header has bad magic number
3153 -11 common/image.c Ramdisk header has bad checksum
3154 10 common/image.c Ramdisk header is OK
3155 -12 common/image.c Ramdisk data has bad checksum
3156 11 common/image.c Ramdisk data has correct checksum
3157 12 common/image.c Ramdisk verification complete, start loading
3158 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3159 13 common/image.c Start multifile image verification
3160 14 common/image.c No initial ramdisk, no multifile, continue.
3162 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3164 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3165 -31 post/post.c POST test failed, detected by post_output_backlog()
3166 -32 post/post.c POST test failed, detected by post_run_single()
3168 34 common/cmd_doc.c before loading a Image from a DOC device
3169 -35 common/cmd_doc.c Bad usage of "doc" command
3170 35 common/cmd_doc.c correct usage of "doc" command
3171 -36 common/cmd_doc.c No boot device
3172 36 common/cmd_doc.c correct boot device
3173 -37 common/cmd_doc.c Unknown Chip ID on boot device
3174 37 common/cmd_doc.c correct chip ID found, device available
3175 -38 common/cmd_doc.c Read Error on boot device
3176 38 common/cmd_doc.c reading Image header from DOC device OK
3177 -39 common/cmd_doc.c Image header has bad magic number
3178 39 common/cmd_doc.c Image header has correct magic number
3179 -40 common/cmd_doc.c Error reading Image from DOC device
3180 40 common/cmd_doc.c Image header has correct magic number
3181 41 common/cmd_ide.c before loading a Image from a IDE device
3182 -42 common/cmd_ide.c Bad usage of "ide" command
3183 42 common/cmd_ide.c correct usage of "ide" command
3184 -43 common/cmd_ide.c No boot device
3185 43 common/cmd_ide.c boot device found
3186 -44 common/cmd_ide.c Device not available
3187 44 common/cmd_ide.c Device available
3188 -45 common/cmd_ide.c wrong partition selected
3189 45 common/cmd_ide.c partition selected
3190 -46 common/cmd_ide.c Unknown partition table
3191 46 common/cmd_ide.c valid partition table found
3192 -47 common/cmd_ide.c Invalid partition type
3193 47 common/cmd_ide.c correct partition type
3194 -48 common/cmd_ide.c Error reading Image Header on boot device
3195 48 common/cmd_ide.c reading Image Header from IDE device OK
3196 -49 common/cmd_ide.c Image header has bad magic number
3197 49 common/cmd_ide.c Image header has correct magic number
3198 -50 common/cmd_ide.c Image header has bad checksum
3199 50 common/cmd_ide.c Image header has correct checksum
3200 -51 common/cmd_ide.c Error reading Image from IDE device
3201 51 common/cmd_ide.c reading Image from IDE device OK
3202 52 common/cmd_nand.c before loading a Image from a NAND device
3203 -53 common/cmd_nand.c Bad usage of "nand" command
3204 53 common/cmd_nand.c correct usage of "nand" command
3205 -54 common/cmd_nand.c No boot device
3206 54 common/cmd_nand.c boot device found
3207 -55 common/cmd_nand.c Unknown Chip ID on boot device
3208 55 common/cmd_nand.c correct chip ID found, device available
3209 -56 common/cmd_nand.c Error reading Image Header on boot device
3210 56 common/cmd_nand.c reading Image Header from NAND device OK
3211 -57 common/cmd_nand.c Image header has bad magic number
3212 57 common/cmd_nand.c Image header has correct magic number
3213 -58 common/cmd_nand.c Error reading Image from NAND device
3214 58 common/cmd_nand.c reading Image from NAND device OK
3216 -60 common/env_common.c Environment has a bad CRC, using default
3218 64 net/eth.c starting with Ethernet configuration.
3219 -64 net/eth.c no Ethernet found.
3220 65 net/eth.c Ethernet found.
3222 -80 common/cmd_net.c usage wrong
3223 80 common/cmd_net.c before calling net_loop()
3224 -81 common/cmd_net.c some error in net_loop() occurred
3225 81 common/cmd_net.c net_loop() back without error
3226 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3227 82 common/cmd_net.c trying automatic boot
3228 83 common/cmd_net.c running "source" command
3229 -83 common/cmd_net.c some error in automatic boot or "source" command
3230 84 common/cmd_net.c end without errors
3235 100 common/cmd_bootm.c Kernel FIT Image has correct format
3236 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3237 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3238 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3239 102 common/cmd_bootm.c Kernel unit name specified
3240 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3241 103 common/cmd_bootm.c Found configuration node
3242 104 common/cmd_bootm.c Got kernel subimage node offset
3243 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3244 105 common/cmd_bootm.c Kernel subimage hash verification OK
3245 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3246 106 common/cmd_bootm.c Architecture check OK
3247 -106 common/cmd_bootm.c Kernel subimage has wrong type
3248 107 common/cmd_bootm.c Kernel subimage type OK
3249 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3250 108 common/cmd_bootm.c Got kernel subimage data/size
3251 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3252 -109 common/cmd_bootm.c Can't get kernel subimage type
3253 -110 common/cmd_bootm.c Can't get kernel subimage comp
3254 -111 common/cmd_bootm.c Can't get kernel subimage os
3255 -112 common/cmd_bootm.c Can't get kernel subimage load address
3256 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3258 120 common/image.c Start initial ramdisk verification
3259 -120 common/image.c Ramdisk FIT image has incorrect format
3260 121 common/image.c Ramdisk FIT image has correct format
3261 122 common/image.c No ramdisk subimage unit name, using configuration
3262 -122 common/image.c Can't get configuration for ramdisk subimage
3263 123 common/image.c Ramdisk unit name specified
3264 -124 common/image.c Can't get ramdisk subimage node offset
3265 125 common/image.c Got ramdisk subimage node offset
3266 -125 common/image.c Ramdisk subimage hash verification failed
3267 126 common/image.c Ramdisk subimage hash verification OK
3268 -126 common/image.c Ramdisk subimage for unsupported architecture
3269 127 common/image.c Architecture check OK
3270 -127 common/image.c Can't get ramdisk subimage data/size
3271 128 common/image.c Got ramdisk subimage data/size
3272 129 common/image.c Can't get ramdisk load address
3273 -129 common/image.c Got ramdisk load address
3275 -130 common/cmd_doc.c Incorrect FIT image format
3276 131 common/cmd_doc.c FIT image format OK
3278 -140 common/cmd_ide.c Incorrect FIT image format
3279 141 common/cmd_ide.c FIT image format OK
3281 -150 common/cmd_nand.c Incorrect FIT image format
3282 151 common/cmd_nand.c FIT image format OK
3284 - legacy image format:
3285 CONFIG_IMAGE_FORMAT_LEGACY
3286 enables the legacy image format support in U-Boot.
3289 enabled if CONFIG_FIT_SIGNATURE is not defined.
3291 CONFIG_DISABLE_IMAGE_LEGACY
3292 disable the legacy image format
3294 This define is introduced, as the legacy image format is
3295 enabled per default for backward compatibility.
3297 - FIT image support:
3299 Enable support for the FIT uImage format.
3301 CONFIG_FIT_BEST_MATCH
3302 When no configuration is explicitly selected, default to the
3303 one whose fdt's compatibility field best matches that of
3304 U-Boot itself. A match is considered "best" if it matches the
3305 most specific compatibility entry of U-Boot's fdt's root node.
3306 The order of entries in the configuration's fdt is ignored.
3308 CONFIG_FIT_SIGNATURE
3309 This option enables signature verification of FIT uImages,
3310 using a hash signed and verified using RSA. If
3311 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3312 hashing is available using hardware, RSA library will use it.
3313 See doc/uImage.FIT/signature.txt for more details.
3315 WARNING: When relying on signed FIT images with required
3316 signature check the legacy image format is default
3317 disabled. If a board need legacy image format support
3318 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3320 CONFIG_FIT_DISABLE_SHA256
3321 Supporting SHA256 hashes has quite an impact on binary size.
3322 For constrained systems sha256 hash support can be disabled
3325 - Standalone program support:
3326 CONFIG_STANDALONE_LOAD_ADDR
3328 This option defines a board specific value for the
3329 address where standalone program gets loaded, thus
3330 overwriting the architecture dependent default
3333 - Frame Buffer Address:
3336 Define CONFIG_FB_ADDR if you want to use specific
3337 address for frame buffer. This is typically the case
3338 when using a graphics controller has separate video
3339 memory. U-Boot will then place the frame buffer at
3340 the given address instead of dynamically reserving it
3341 in system RAM by calling lcd_setmem(), which grabs
3342 the memory for the frame buffer depending on the
3343 configured panel size.
3345 Please see board_init_f function.
3347 - Automatic software updates via TFTP server
3349 CONFIG_UPDATE_TFTP_CNT_MAX
3350 CONFIG_UPDATE_TFTP_MSEC_MAX
3352 These options enable and control the auto-update feature;
3353 for a more detailed description refer to doc/README.update.
3355 - MTD Support (mtdparts command, UBI support)
3358 Adds the MTD device infrastructure from the Linux kernel.
3359 Needed for mtdparts command support.
3361 CONFIG_MTD_PARTITIONS
3363 Adds the MTD partitioning infrastructure from the Linux
3364 kernel. Needed for UBI support.
3369 Adds commands for interacting with MTD partitions formatted
3370 with the UBI flash translation layer
3372 Requires also defining CONFIG_RBTREE
3374 CONFIG_UBI_SILENCE_MSG
3376 Make the verbose messages from UBI stop printing. This leaves
3377 warnings and errors enabled.
3380 CONFIG_MTD_UBI_WL_THRESHOLD
3381 This parameter defines the maximum difference between the highest
3382 erase counter value and the lowest erase counter value of eraseblocks
3383 of UBI devices. When this threshold is exceeded, UBI starts performing
3384 wear leveling by means of moving data from eraseblock with low erase
3385 counter to eraseblocks with high erase counter.
3387 The default value should be OK for SLC NAND flashes, NOR flashes and
3388 other flashes which have eraseblock life-cycle 100000 or more.
3389 However, in case of MLC NAND flashes which typically have eraseblock
3390 life-cycle less than 10000, the threshold should be lessened (e.g.,
3391 to 128 or 256, although it does not have to be power of 2).
3395 CONFIG_MTD_UBI_BEB_LIMIT
3396 This option specifies the maximum bad physical eraseblocks UBI
3397 expects on the MTD device (per 1024 eraseblocks). If the
3398 underlying flash does not admit of bad eraseblocks (e.g. NOR
3399 flash), this value is ignored.
3401 NAND datasheets often specify the minimum and maximum NVM
3402 (Number of Valid Blocks) for the flashes' endurance lifetime.
3403 The maximum expected bad eraseblocks per 1024 eraseblocks
3404 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3405 which gives 20 for most NANDs (MaxNVB is basically the total
3406 count of eraseblocks on the chip).
3408 To put it differently, if this value is 20, UBI will try to
3409 reserve about 1.9% of physical eraseblocks for bad blocks
3410 handling. And that will be 1.9% of eraseblocks on the entire
3411 NAND chip, not just the MTD partition UBI attaches. This means
3412 that if you have, say, a NAND flash chip admits maximum 40 bad
3413 eraseblocks, and it is split on two MTD partitions of the same
3414 size, UBI will reserve 40 eraseblocks when attaching a
3419 CONFIG_MTD_UBI_FASTMAP
3420 Fastmap is a mechanism which allows attaching an UBI device
3421 in nearly constant time. Instead of scanning the whole MTD device it
3422 only has to locate a checkpoint (called fastmap) on the device.
3423 The on-flash fastmap contains all information needed to attach
3424 the device. Using fastmap makes only sense on large devices where
3425 attaching by scanning takes long. UBI will not automatically install
3426 a fastmap on old images, but you can set the UBI parameter
3427 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3428 that fastmap-enabled images are still usable with UBI implementations
3429 without fastmap support. On typical flash devices the whole fastmap
3430 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3432 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3433 Set this parameter to enable fastmap automatically on images
3437 CONFIG_MTD_UBI_FM_DEBUG
3438 Enable UBI fastmap debug
3444 Adds commands for interacting with UBI volumes formatted as
3445 UBIFS. UBIFS is read-only in u-boot.
3447 Requires UBI support as well as CONFIG_LZO
3449 CONFIG_UBIFS_SILENCE_MSG
3451 Make the verbose messages from UBIFS stop printing. This leaves
3452 warnings and errors enabled.
3456 Enable building of SPL globally.
3459 LDSCRIPT for linking the SPL binary.
3461 CONFIG_SPL_MAX_FOOTPRINT
3462 Maximum size in memory allocated to the SPL, BSS included.
3463 When defined, the linker checks that the actual memory
3464 used by SPL from _start to __bss_end does not exceed it.
3465 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3466 must not be both defined at the same time.
3469 Maximum size of the SPL image (text, data, rodata, and
3470 linker lists sections), BSS excluded.
3471 When defined, the linker checks that the actual size does
3474 CONFIG_SPL_TEXT_BASE
3475 TEXT_BASE for linking the SPL binary.
3477 CONFIG_SPL_RELOC_TEXT_BASE
3478 Address to relocate to. If unspecified, this is equal to
3479 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3481 CONFIG_SPL_BSS_START_ADDR
3482 Link address for the BSS within the SPL binary.
3484 CONFIG_SPL_BSS_MAX_SIZE
3485 Maximum size in memory allocated to the SPL BSS.
3486 When defined, the linker checks that the actual memory used
3487 by SPL from __bss_start to __bss_end does not exceed it.
3488 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3489 must not be both defined at the same time.
3492 Adress of the start of the stack SPL will use
3494 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3495 When defined, SPL will panic() if the image it has
3496 loaded does not have a signature.
3497 Defining this is useful when code which loads images
3498 in SPL cannot guarantee that absolutely all read errors
3500 An example is the LPC32XX MLC NAND driver, which will
3501 consider that a completely unreadable NAND block is bad,
3502 and thus should be skipped silently.
3504 CONFIG_SPL_RELOC_STACK
3505 Adress of the start of the stack SPL will use after
3506 relocation. If unspecified, this is equal to
3509 CONFIG_SYS_SPL_MALLOC_START
3510 Starting address of the malloc pool used in SPL.
3511 When this option is set the full malloc is used in SPL and
3512 it is set up by spl_init() and before that, the simple malloc()
3513 can be used if CONFIG_SYS_MALLOC_F is defined.
3515 CONFIG_SYS_SPL_MALLOC_SIZE
3516 The size of the malloc pool used in SPL.
3518 CONFIG_SPL_FRAMEWORK
3519 Enable the SPL framework under common/. This framework
3520 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3521 NAND loading of the Linux Kernel.
3524 Enable booting directly to an OS from SPL.
3525 See also: doc/README.falcon
3527 CONFIG_SPL_DISPLAY_PRINT
3528 For ARM, enable an optional function to print more information
3529 about the running system.
3531 CONFIG_SPL_INIT_MINIMAL
3532 Arch init code should be built for a very small image
3534 CONFIG_SPL_LIBCOMMON_SUPPORT
3535 Support for common/libcommon.o in SPL binary
3537 CONFIG_SPL_LIBDISK_SUPPORT
3538 Support for disk/libdisk.o in SPL binary
3540 CONFIG_SPL_I2C_SUPPORT
3541 Support for drivers/i2c/libi2c.o in SPL binary
3543 CONFIG_SPL_GPIO_SUPPORT
3544 Support for drivers/gpio/libgpio.o in SPL binary
3546 CONFIG_SPL_MMC_SUPPORT
3547 Support for drivers/mmc/libmmc.o in SPL binary
3549 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3550 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3551 Address and partition on the MMC to load U-Boot from
3552 when the MMC is being used in raw mode.
3554 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3555 Partition on the MMC to load U-Boot from when the MMC is being
3558 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3559 Sector to load kernel uImage from when MMC is being
3560 used in raw mode (for Falcon mode)
3562 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3563 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3564 Sector and number of sectors to load kernel argument
3565 parameters from when MMC is being used in raw mode
3568 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3569 Partition on the MMC to load U-Boot from when the MMC is being
3572 CONFIG_SPL_FAT_SUPPORT
3573 Support for fs/fat/libfat.o in SPL binary
3575 CONFIG_SPL_EXT_SUPPORT
3576 Support for EXT filesystem in SPL binary
3578 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3579 Filename to read to load U-Boot when reading from filesystem
3581 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3582 Filename to read to load kernel uImage when reading
3583 from filesystem (for Falcon mode)
3585 CONFIG_SPL_FS_LOAD_ARGS_NAME
3586 Filename to read to load kernel argument parameters
3587 when reading from filesystem (for Falcon mode)
3589 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3590 Set this for NAND SPL on PPC mpc83xx targets, so that
3591 start.S waits for the rest of the SPL to load before
3592 continuing (the hardware starts execution after just
3593 loading the first page rather than the full 4K).
3595 CONFIG_SPL_SKIP_RELOCATE
3596 Avoid SPL relocation
3598 CONFIG_SPL_NAND_BASE
3599 Include nand_base.c in the SPL. Requires
3600 CONFIG_SPL_NAND_DRIVERS.
3602 CONFIG_SPL_NAND_DRIVERS
3603 SPL uses normal NAND drivers, not minimal drivers.
3606 Include standard software ECC in the SPL
3608 CONFIG_SPL_NAND_SIMPLE
3609 Support for NAND boot using simple NAND drivers that
3610 expose the cmd_ctrl() interface.
3612 CONFIG_SPL_MTD_SUPPORT
3613 Support for the MTD subsystem within SPL. Useful for
3614 environment on NAND support within SPL.
3616 CONFIG_SPL_NAND_RAW_ONLY
3617 Support to boot only raw u-boot.bin images. Use this only
3618 if you need to save space.
3620 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3621 Set for the SPL on PPC mpc8xxx targets, support for
3622 drivers/ddr/fsl/libddr.o in SPL binary.
3624 CONFIG_SPL_COMMON_INIT_DDR
3625 Set for common ddr init with serial presence detect in
3628 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3629 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3630 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3631 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3632 CONFIG_SYS_NAND_ECCBYTES
3633 Defines the size and behavior of the NAND that SPL uses
3636 CONFIG_SPL_NAND_BOOT
3637 Add support NAND boot
3639 CONFIG_SYS_NAND_U_BOOT_OFFS
3640 Location in NAND to read U-Boot from
3642 CONFIG_SYS_NAND_U_BOOT_DST
3643 Location in memory to load U-Boot to
3645 CONFIG_SYS_NAND_U_BOOT_SIZE
3646 Size of image to load
3648 CONFIG_SYS_NAND_U_BOOT_START
3649 Entry point in loaded image to jump to
3651 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3652 Define this if you need to first read the OOB and then the
3653 data. This is used, for example, on davinci platforms.
3655 CONFIG_SPL_OMAP3_ID_NAND
3656 Support for an OMAP3-specific set of functions to return the
3657 ID and MFR of the first attached NAND chip, if present.
3659 CONFIG_SPL_SERIAL_SUPPORT
3660 Support for drivers/serial/libserial.o in SPL binary
3662 CONFIG_SPL_SPI_FLASH_SUPPORT
3663 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3665 CONFIG_SPL_SPI_SUPPORT
3666 Support for drivers/spi/libspi.o in SPL binary
3668 CONFIG_SPL_RAM_DEVICE
3669 Support for running image already present in ram, in SPL binary
3671 CONFIG_SPL_LIBGENERIC_SUPPORT
3672 Support for lib/libgeneric.o in SPL binary
3674 CONFIG_SPL_ENV_SUPPORT
3675 Support for the environment operating in SPL binary
3677 CONFIG_SPL_NET_SUPPORT
3678 Support for the net/libnet.o in SPL binary.
3679 It conflicts with SPL env from storage medium specified by
3680 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3683 Image offset to which the SPL should be padded before appending
3684 the SPL payload. By default, this is defined as
3685 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3686 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3687 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3690 Final target image containing SPL and payload. Some SPLs
3691 use an arch-specific makefile fragment instead, for
3692 example if more than one image needs to be produced.
3694 CONFIG_FIT_SPL_PRINT
3695 Printing information about a FIT image adds quite a bit of
3696 code to SPL. So this is normally disabled in SPL. Use this
3697 option to re-enable it. This will affect the output of the
3698 bootm command when booting a FIT image.
3702 Enable building of TPL globally.
3705 Image offset to which the TPL should be padded before appending
3706 the TPL payload. By default, this is defined as
3707 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3708 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3709 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3714 [so far only for SMDK2400 boards]
3716 - Modem support enable:
3717 CONFIG_MODEM_SUPPORT
3719 - RTS/CTS Flow control enable:
3722 - Interrupt support (PPC):
3724 There are common interrupt_init() and timer_interrupt()
3725 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3726 for CPU specific initialization. interrupt_init_cpu()
3727 should set decrementer_count to appropriate value. If
3728 CPU resets decrementer automatically after interrupt
3729 (ppc4xx) it should set decrementer_count to zero.
3730 timer_interrupt() calls timer_interrupt_cpu() for CPU
3731 specific handling. If board has watchdog / status_led
3732 / other_activity_monitor it works automatically from
3733 general timer_interrupt().
3737 In the target system modem support is enabled when a
3738 specific key (key combination) is pressed during
3739 power-on. Otherwise U-Boot will boot normally
3740 (autoboot). The key_pressed() function is called from
3741 board_init(). Currently key_pressed() is a dummy
3742 function, returning 1 and thus enabling modem
3745 If there are no modem init strings in the
3746 environment, U-Boot proceed to autoboot; the
3747 previous output (banner, info printfs) will be
3750 See also: doc/README.Modem
3752 Board initialization settings:
3753 ------------------------------
3755 During Initialization u-boot calls a number of board specific functions
3756 to allow the preparation of board specific prerequisites, e.g. pin setup
3757 before drivers are initialized. To enable these callbacks the
3758 following configuration macros have to be defined. Currently this is
3759 architecture specific, so please check arch/your_architecture/lib/board.c
3760 typically in board_init_f() and board_init_r().
3762 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3763 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3764 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3765 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3767 Configuration Settings:
3768 -----------------------
3770 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3771 Optionally it can be defined to support 64-bit memory commands.
3773 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3774 undefine this when you're short of memory.
3776 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3777 width of the commands listed in the 'help' command output.
3779 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3780 prompt for user input.
3782 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3784 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3786 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3788 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3789 the application (usually a Linux kernel) when it is
3792 - CONFIG_SYS_BAUDRATE_TABLE:
3793 List of legal baudrate settings for this board.
3795 - CONFIG_SYS_CONSOLE_INFO_QUIET
3796 Suppress display of console information at boot.
3798 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3799 If the board specific function
3800 extern int overwrite_console (void);
3801 returns 1, the stdin, stderr and stdout are switched to the
3802 serial port, else the settings in the environment are used.
3804 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3805 Enable the call to overwrite_console().
3807 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3808 Enable overwrite of previous console environment settings.
3810 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3811 Begin and End addresses of the area used by the
3814 - CONFIG_SYS_ALT_MEMTEST:
3815 Enable an alternate, more extensive memory test.
3817 - CONFIG_SYS_MEMTEST_SCRATCH:
3818 Scratch address used by the alternate memory test
3819 You only need to set this if address zero isn't writeable
3821 - CONFIG_SYS_MEM_RESERVE_SECURE
3822 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3823 is substracted from total RAM and won't be reported to OS.
3824 This memory can be used as secure memory. A variable
3825 gd->secure_ram is used to track the location. In systems
3826 the RAM base is not zero, or RAM is divided into banks,
3827 this variable needs to be recalcuated to get the address.
3829 - CONFIG_SYS_MEM_TOP_HIDE:
3830 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3831 this specified memory area will get subtracted from the top
3832 (end) of RAM and won't get "touched" at all by U-Boot. By
3833 fixing up gd->ram_size the Linux kernel should gets passed
3834 the now "corrected" memory size and won't touch it either.
3835 This should work for arch/ppc and arch/powerpc. Only Linux
3836 board ports in arch/powerpc with bootwrapper support that
3837 recalculate the memory size from the SDRAM controller setup
3838 will have to get fixed in Linux additionally.
3840 This option can be used as a workaround for the 440EPx/GRx
3841 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3844 WARNING: Please make sure that this value is a multiple of
3845 the Linux page size (normally 4k). If this is not the case,
3846 then the end address of the Linux memory will be located at a
3847 non page size aligned address and this could cause major
3850 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3851 Enable temporary baudrate change while serial download
3853 - CONFIG_SYS_SDRAM_BASE:
3854 Physical start address of SDRAM. _Must_ be 0 here.
3856 - CONFIG_SYS_MBIO_BASE:
3857 Physical start address of Motherboard I/O (if using a
3860 - CONFIG_SYS_FLASH_BASE:
3861 Physical start address of Flash memory.
3863 - CONFIG_SYS_MONITOR_BASE:
3864 Physical start address of boot monitor code (set by
3865 make config files to be same as the text base address
3866 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3867 CONFIG_SYS_FLASH_BASE when booting from flash.
3869 - CONFIG_SYS_MONITOR_LEN:
3870 Size of memory reserved for monitor code, used to
3871 determine _at_compile_time_ (!) if the environment is
3872 embedded within the U-Boot image, or in a separate
3875 - CONFIG_SYS_MALLOC_LEN:
3876 Size of DRAM reserved for malloc() use.
3878 - CONFIG_SYS_MALLOC_F_LEN
3879 Size of the malloc() pool for use before relocation. If
3880 this is defined, then a very simple malloc() implementation
3881 will become available before relocation. The address is just
3882 below the global data, and the stack is moved down to make
3885 This feature allocates regions with increasing addresses
3886 within the region. calloc() is supported, but realloc()
3887 is not available. free() is supported but does nothing.
3888 The memory will be freed (or in fact just forgotten) when
3889 U-Boot relocates itself.
3891 Pre-relocation malloc() is only supported on ARM and sandbox
3892 at present but is fairly easy to enable for other archs.
3894 - CONFIG_SYS_MALLOC_SIMPLE
3895 Provides a simple and small malloc() and calloc() for those
3896 boards which do not use the full malloc in SPL (which is
3897 enabled with CONFIG_SYS_SPL_MALLOC_START).
3899 - CONFIG_SYS_NONCACHED_MEMORY:
3900 Size of non-cached memory area. This area of memory will be
3901 typically located right below the malloc() area and mapped
3902 uncached in the MMU. This is useful for drivers that would
3903 otherwise require a lot of explicit cache maintenance. For
3904 some drivers it's also impossible to properly maintain the
3905 cache. For example if the regions that need to be flushed
3906 are not a multiple of the cache-line size, *and* padding
3907 cannot be allocated between the regions to align them (i.e.
3908 if the HW requires a contiguous array of regions, and the
3909 size of each region is not cache-aligned), then a flush of
3910 one region may result in overwriting data that hardware has
3911 written to another region in the same cache-line. This can
3912 happen for example in network drivers where descriptors for
3913 buffers are typically smaller than the CPU cache-line (e.g.
3914 16 bytes vs. 32 or 64 bytes).
3916 Non-cached memory is only supported on 32-bit ARM at present.
3918 - CONFIG_SYS_BOOTM_LEN:
3919 Normally compressed uImages are limited to an
3920 uncompressed size of 8 MBytes. If this is not enough,
3921 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3922 to adjust this setting to your needs.
3924 - CONFIG_SYS_BOOTMAPSZ:
3925 Maximum size of memory mapped by the startup code of
3926 the Linux kernel; all data that must be processed by
3927 the Linux kernel (bd_info, boot arguments, FDT blob if
3928 used) must be put below this limit, unless "bootm_low"
3929 environment variable is defined and non-zero. In such case
3930 all data for the Linux kernel must be between "bootm_low"
3931 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3932 variable "bootm_mapsize" will override the value of
3933 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3934 then the value in "bootm_size" will be used instead.
3936 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3937 Enable initrd_high functionality. If defined then the
3938 initrd_high feature is enabled and the bootm ramdisk subcommand
3941 - CONFIG_SYS_BOOT_GET_CMDLINE:
3942 Enables allocating and saving kernel cmdline in space between
3943 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3945 - CONFIG_SYS_BOOT_GET_KBD:
3946 Enables allocating and saving a kernel copy of the bd_info in
3947 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3949 - CONFIG_SYS_MAX_FLASH_BANKS:
3950 Max number of Flash memory banks
3952 - CONFIG_SYS_MAX_FLASH_SECT:
3953 Max number of sectors on a Flash chip
3955 - CONFIG_SYS_FLASH_ERASE_TOUT:
3956 Timeout for Flash erase operations (in ms)
3958 - CONFIG_SYS_FLASH_WRITE_TOUT:
3959 Timeout for Flash write operations (in ms)
3961 - CONFIG_SYS_FLASH_LOCK_TOUT
3962 Timeout for Flash set sector lock bit operation (in ms)
3964 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3965 Timeout for Flash clear lock bits operation (in ms)
3967 - CONFIG_SYS_FLASH_PROTECTION
3968 If defined, hardware flash sectors protection is used
3969 instead of U-Boot software protection.
3971 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3973 Enable TFTP transfers directly to flash memory;
3974 without this option such a download has to be
3975 performed in two steps: (1) download to RAM, and (2)
3976 copy from RAM to flash.
3978 The two-step approach is usually more reliable, since
3979 you can check if the download worked before you erase
3980 the flash, but in some situations (when system RAM is
3981 too limited to allow for a temporary copy of the
3982 downloaded image) this option may be very useful.
3984 - CONFIG_SYS_FLASH_CFI:
3985 Define if the flash driver uses extra elements in the
3986 common flash structure for storing flash geometry.
3988 - CONFIG_FLASH_CFI_DRIVER
3989 This option also enables the building of the cfi_flash driver
3990 in the drivers directory
3992 - CONFIG_FLASH_CFI_MTD
3993 This option enables the building of the cfi_mtd driver
3994 in the drivers directory. The driver exports CFI flash
3997 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3998 Use buffered writes to flash.
4000 - CONFIG_FLASH_SPANSION_S29WS_N
4001 s29ws-n MirrorBit flash has non-standard addresses for buffered
4004 - CONFIG_SYS_FLASH_QUIET_TEST
4005 If this option is defined, the common CFI flash doesn't
4006 print it's warning upon not recognized FLASH banks. This
4007 is useful, if some of the configured banks are only
4008 optionally available.
4010 - CONFIG_FLASH_SHOW_PROGRESS
4011 If defined (must be an integer), print out countdown
4012 digits and dots. Recommended value: 45 (9..1) for 80
4013 column displays, 15 (3..1) for 40 column displays.
4015 - CONFIG_FLASH_VERIFY
4016 If defined, the content of the flash (destination) is compared
4017 against the source after the write operation. An error message
4018 will be printed when the contents are not identical.
4019 Please note that this option is useless in nearly all cases,
4020 since such flash programming errors usually are detected earlier
4021 while unprotecting/erasing/programming. Please only enable
4022 this option if you really know what you are doing.
4024 - CONFIG_SYS_RX_ETH_BUFFER:
4025 Defines the number of Ethernet receive buffers. On some
4026 Ethernet controllers it is recommended to set this value
4027 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4028 buffers can be full shortly after enabling the interface
4029 on high Ethernet traffic.
4030 Defaults to 4 if not defined.
4032 - CONFIG_ENV_MAX_ENTRIES
4034 Maximum number of entries in the hash table that is used
4035 internally to store the environment settings. The default
4036 setting is supposed to be generous and should work in most
4037 cases. This setting can be used to tune behaviour; see
4038 lib/hashtable.c for details.
4040 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4041 - CONFIG_ENV_FLAGS_LIST_STATIC
4042 Enable validation of the values given to environment variables when
4043 calling env set. Variables can be restricted to only decimal,
4044 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4045 the variables can also be restricted to IP address or MAC address.
4047 The format of the list is:
4048 type_attribute = [s|d|x|b|i|m]
4049 access_attribute = [a|r|o|c]
4050 attributes = type_attribute[access_attribute]
4051 entry = variable_name[:attributes]
4054 The type attributes are:
4055 s - String (default)
4058 b - Boolean ([1yYtT|0nNfF])
4062 The access attributes are:
4068 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4069 Define this to a list (string) to define the ".flags"
4070 environment variable in the default or embedded environment.
4072 - CONFIG_ENV_FLAGS_LIST_STATIC
4073 Define this to a list (string) to define validation that
4074 should be done if an entry is not found in the ".flags"
4075 environment variable. To override a setting in the static
4076 list, simply add an entry for the same variable name to the
4079 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4080 regular expression. This allows multiple variables to define the same
4081 flags without explicitly listing them for each variable.
4083 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4084 If defined, don't allow the -f switch to env set override variable
4087 - CONFIG_SYS_GENERIC_BOARD
4088 This selects the architecture-generic board system instead of the
4089 architecture-specific board files. It is intended to move boards
4090 to this new framework over time. Defining this will disable the
4091 arch/foo/lib/board.c file and use common/board_f.c and
4092 common/board_r.c instead. To use this option your architecture
4093 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4094 If you find problems enabling this option on your board please report
4095 the problem and send patches!
4097 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4098 This is set by OMAP boards for the max time that reset should
4099 be asserted. See doc/README.omap-reset-time for details on how
4100 the value can be calculated on a given board.
4103 If stdint.h is available with your toolchain you can define this
4104 option to enable it. You can provide option 'USE_STDINT=1' when
4105 building U-Boot to enable this.
4107 The following definitions that deal with the placement and management
4108 of environment data (variable area); in general, we support the
4109 following configurations:
4111 - CONFIG_BUILD_ENVCRC:
4113 Builds up envcrc with the target environment so that external utils
4114 may easily extract it and embed it in final U-Boot images.
4116 - CONFIG_ENV_IS_IN_FLASH:
4118 Define this if the environment is in flash memory.
4120 a) The environment occupies one whole flash sector, which is
4121 "embedded" in the text segment with the U-Boot code. This
4122 happens usually with "bottom boot sector" or "top boot
4123 sector" type flash chips, which have several smaller
4124 sectors at the start or the end. For instance, such a
4125 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4126 such a case you would place the environment in one of the
4127 4 kB sectors - with U-Boot code before and after it. With
4128 "top boot sector" type flash chips, you would put the
4129 environment in one of the last sectors, leaving a gap
4130 between U-Boot and the environment.
4132 - CONFIG_ENV_OFFSET:
4134 Offset of environment data (variable area) to the
4135 beginning of flash memory; for instance, with bottom boot
4136 type flash chips the second sector can be used: the offset
4137 for this sector is given here.
4139 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4143 This is just another way to specify the start address of
4144 the flash sector containing the environment (instead of
4147 - CONFIG_ENV_SECT_SIZE:
4149 Size of the sector containing the environment.
4152 b) Sometimes flash chips have few, equal sized, BIG sectors.
4153 In such a case you don't want to spend a whole sector for
4158 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4159 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4160 of this flash sector for the environment. This saves
4161 memory for the RAM copy of the environment.
4163 It may also save flash memory if you decide to use this
4164 when your environment is "embedded" within U-Boot code,
4165 since then the remainder of the flash sector could be used
4166 for U-Boot code. It should be pointed out that this is
4167 STRONGLY DISCOURAGED from a robustness point of view:
4168 updating the environment in flash makes it always
4169 necessary to erase the WHOLE sector. If something goes
4170 wrong before the contents has been restored from a copy in
4171 RAM, your target system will be dead.
4173 - CONFIG_ENV_ADDR_REDUND
4174 CONFIG_ENV_SIZE_REDUND
4176 These settings describe a second storage area used to hold
4177 a redundant copy of the environment data, so that there is
4178 a valid backup copy in case there is a power failure during
4179 a "saveenv" operation.
4181 BE CAREFUL! Any changes to the flash layout, and some changes to the
4182 source code will make it necessary to adapt <board>/u-boot.lds*
4186 - CONFIG_ENV_IS_IN_NVRAM:
4188 Define this if you have some non-volatile memory device
4189 (NVRAM, battery buffered SRAM) which you want to use for the
4195 These two #defines are used to determine the memory area you
4196 want to use for environment. It is assumed that this memory
4197 can just be read and written to, without any special
4200 BE CAREFUL! The first access to the environment happens quite early
4201 in U-Boot initialization (when we try to get the setting of for the
4202 console baudrate). You *MUST* have mapped your NVRAM area then, or
4205 Please note that even with NVRAM we still use a copy of the
4206 environment in RAM: we could work on NVRAM directly, but we want to
4207 keep settings there always unmodified except somebody uses "saveenv"
4208 to save the current settings.
4211 - CONFIG_ENV_IS_IN_EEPROM:
4213 Use this if you have an EEPROM or similar serial access
4214 device and a driver for it.
4216 - CONFIG_ENV_OFFSET:
4219 These two #defines specify the offset and size of the
4220 environment area within the total memory of your EEPROM.
4222 - CONFIG_SYS_I2C_EEPROM_ADDR:
4223 If defined, specified the chip address of the EEPROM device.
4224 The default address is zero.
4226 - CONFIG_SYS_I2C_EEPROM_BUS:
4227 If defined, specified the i2c bus of the EEPROM device.
4229 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4230 If defined, the number of bits used to address bytes in a
4231 single page in the EEPROM device. A 64 byte page, for example
4232 would require six bits.
4234 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4235 If defined, the number of milliseconds to delay between
4236 page writes. The default is zero milliseconds.
4238 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4239 The length in bytes of the EEPROM memory array address. Note
4240 that this is NOT the chip address length!
4242 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4243 EEPROM chips that implement "address overflow" are ones
4244 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4245 address and the extra bits end up in the "chip address" bit
4246 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4249 Note that we consider the length of the address field to
4250 still be one byte because the extra address bits are hidden
4251 in the chip address.
4253 - CONFIG_SYS_EEPROM_SIZE:
4254 The size in bytes of the EEPROM device.
4256 - CONFIG_ENV_EEPROM_IS_ON_I2C
4257 define this, if you have I2C and SPI activated, and your
4258 EEPROM, which holds the environment, is on the I2C bus.
4260 - CONFIG_I2C_ENV_EEPROM_BUS
4261 if you have an Environment on an EEPROM reached over
4262 I2C muxes, you can define here, how to reach this
4263 EEPROM. For example:
4265 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4267 EEPROM which holds the environment, is reached over
4268 a pca9547 i2c mux with address 0x70, channel 3.
4270 - CONFIG_ENV_IS_IN_DATAFLASH:
4272 Define this if you have a DataFlash memory device which you
4273 want to use for the environment.
4275 - CONFIG_ENV_OFFSET:
4279 These three #defines specify the offset and size of the
4280 environment area within the total memory of your DataFlash placed
4281 at the specified address.
4283 - CONFIG_ENV_IS_IN_SPI_FLASH:
4285 Define this if you have a SPI Flash memory device which you
4286 want to use for the environment.
4288 - CONFIG_ENV_OFFSET:
4291 These two #defines specify the offset and size of the
4292 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4293 aligned to an erase sector boundary.
4295 - CONFIG_ENV_SECT_SIZE:
4297 Define the SPI flash's sector size.
4299 - CONFIG_ENV_OFFSET_REDUND (optional):
4301 This setting describes a second storage area of CONFIG_ENV_SIZE
4302 size used to hold a redundant copy of the environment data, so
4303 that there is a valid backup copy in case there is a power failure
4304 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4305 aligned to an erase sector boundary.
4307 - CONFIG_ENV_SPI_BUS (optional):
4308 - CONFIG_ENV_SPI_CS (optional):
4310 Define the SPI bus and chip select. If not defined they will be 0.
4312 - CONFIG_ENV_SPI_MAX_HZ (optional):
4314 Define the SPI max work clock. If not defined then use 1MHz.
4316 - CONFIG_ENV_SPI_MODE (optional):
4318 Define the SPI work mode. If not defined then use SPI_MODE_3.
4320 - CONFIG_ENV_IS_IN_REMOTE:
4322 Define this if you have a remote memory space which you
4323 want to use for the local device's environment.
4328 These two #defines specify the address and size of the
4329 environment area within the remote memory space. The
4330 local device can get the environment from remote memory
4331 space by SRIO or PCIE links.
4333 BE CAREFUL! For some special cases, the local device can not use
4334 "saveenv" command. For example, the local device will get the
4335 environment stored in a remote NOR flash by SRIO or PCIE link,
4336 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4338 - CONFIG_ENV_IS_IN_NAND:
4340 Define this if you have a NAND device which you want to use
4341 for the environment.
4343 - CONFIG_ENV_OFFSET:
4346 These two #defines specify the offset and size of the environment
4347 area within the first NAND device. CONFIG_ENV_OFFSET must be
4348 aligned to an erase block boundary.
4350 - CONFIG_ENV_OFFSET_REDUND (optional):
4352 This setting describes a second storage area of CONFIG_ENV_SIZE
4353 size used to hold a redundant copy of the environment data, so
4354 that there is a valid backup copy in case there is a power failure
4355 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4356 aligned to an erase block boundary.
4358 - CONFIG_ENV_RANGE (optional):
4360 Specifies the length of the region in which the environment
4361 can be written. This should be a multiple of the NAND device's
4362 block size. Specifying a range with more erase blocks than
4363 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4364 the range to be avoided.
4366 - CONFIG_ENV_OFFSET_OOB (optional):
4368 Enables support for dynamically retrieving the offset of the
4369 environment from block zero's out-of-band data. The
4370 "nand env.oob" command can be used to record this offset.
4371 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4372 using CONFIG_ENV_OFFSET_OOB.
4374 - CONFIG_NAND_ENV_DST
4376 Defines address in RAM to which the nand_spl code should copy the
4377 environment. If redundant environment is used, it will be copied to
4378 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4380 - CONFIG_ENV_IS_IN_UBI:
4382 Define this if you have an UBI volume that you want to use for the
4383 environment. This has the benefit of wear-leveling the environment
4384 accesses, which is important on NAND.
4386 - CONFIG_ENV_UBI_PART:
4388 Define this to a string that is the mtd partition containing the UBI.
4390 - CONFIG_ENV_UBI_VOLUME:
4392 Define this to the name of the volume that you want to store the
4395 - CONFIG_ENV_UBI_VOLUME_REDUND:
4397 Define this to the name of another volume to store a second copy of
4398 the environment in. This will enable redundant environments in UBI.
4399 It is assumed that both volumes are in the same MTD partition.
4401 - CONFIG_UBI_SILENCE_MSG
4402 - CONFIG_UBIFS_SILENCE_MSG
4404 You will probably want to define these to avoid a really noisy system
4405 when storing the env in UBI.
4407 - CONFIG_ENV_IS_IN_FAT:
4408 Define this if you want to use the FAT file system for the environment.
4410 - FAT_ENV_INTERFACE:
4412 Define this to a string that is the name of the block device.
4414 - FAT_ENV_DEV_AND_PART:
4416 Define this to a string to specify the partition of the device. It can
4419 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4420 - "D:P": device D partition P. Error occurs if device D has no
4423 - "D" or "D:": device D partition 1 if device D has partition
4424 table, or the whole device D if has no partition
4426 - "D:auto": first partition in device D with bootable flag set.
4427 If none, first valid partition in device D. If no
4428 partition table then means device D.
4432 It's a string of the FAT file name. This file use to store the
4436 This should be defined. Otherwise it cannot save the environment file.
4438 - CONFIG_ENV_IS_IN_MMC:
4440 Define this if you have an MMC device which you want to use for the
4443 - CONFIG_SYS_MMC_ENV_DEV:
4445 Specifies which MMC device the environment is stored in.
4447 - CONFIG_SYS_MMC_ENV_PART (optional):
4449 Specifies which MMC partition the environment is stored in. If not
4450 set, defaults to partition 0, the user area. Common values might be
4451 1 (first MMC boot partition), 2 (second MMC boot partition).
4453 - CONFIG_ENV_OFFSET:
4456 These two #defines specify the offset and size of the environment
4457 area within the specified MMC device.
4459 If offset is positive (the usual case), it is treated as relative to
4460 the start of the MMC partition. If offset is negative, it is treated
4461 as relative to the end of the MMC partition. This can be useful if
4462 your board may be fitted with different MMC devices, which have
4463 different sizes for the MMC partitions, and you always want the
4464 environment placed at the very end of the partition, to leave the
4465 maximum possible space before it, to store other data.
4467 These two values are in units of bytes, but must be aligned to an
4468 MMC sector boundary.
4470 - CONFIG_ENV_OFFSET_REDUND (optional):
4472 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4473 hold a redundant copy of the environment data. This provides a
4474 valid backup copy in case the other copy is corrupted, e.g. due
4475 to a power failure during a "saveenv" operation.
4477 This value may also be positive or negative; this is handled in the
4478 same way as CONFIG_ENV_OFFSET.
4480 This value is also in units of bytes, but must also be aligned to
4481 an MMC sector boundary.
4483 - CONFIG_ENV_SIZE_REDUND (optional):
4485 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4486 set. If this value is set, it must be set to the same value as
4489 - CONFIG_SYS_SPI_INIT_OFFSET
4491 Defines offset to the initial SPI buffer area in DPRAM. The
4492 area is used at an early stage (ROM part) if the environment
4493 is configured to reside in the SPI EEPROM: We need a 520 byte
4494 scratch DPRAM area. It is used between the two initialization
4495 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4496 to be a good choice since it makes it far enough from the
4497 start of the data area as well as from the stack pointer.
4499 Please note that the environment is read-only until the monitor
4500 has been relocated to RAM and a RAM copy of the environment has been
4501 created; also, when using EEPROM you will have to use getenv_f()
4502 until then to read environment variables.
4504 The environment is protected by a CRC32 checksum. Before the monitor
4505 is relocated into RAM, as a result of a bad CRC you will be working
4506 with the compiled-in default environment - *silently*!!! [This is
4507 necessary, because the first environment variable we need is the
4508 "baudrate" setting for the console - if we have a bad CRC, we don't
4509 have any device yet where we could complain.]
4511 Note: once the monitor has been relocated, then it will complain if
4512 the default environment is used; a new CRC is computed as soon as you
4513 use the "saveenv" command to store a valid environment.
4515 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4516 Echo the inverted Ethernet link state to the fault LED.
4518 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4519 also needs to be defined.
4521 - CONFIG_SYS_FAULT_MII_ADDR:
4522 MII address of the PHY to check for the Ethernet link state.
4524 - CONFIG_NS16550_MIN_FUNCTIONS:
4525 Define this if you desire to only have use of the NS16550_init
4526 and NS16550_putc functions for the serial driver located at
4527 drivers/serial/ns16550.c. This option is useful for saving
4528 space for already greatly restricted images, including but not
4529 limited to NAND_SPL configurations.
4531 - CONFIG_DISPLAY_BOARDINFO
4532 Display information about the board that U-Boot is running on
4533 when U-Boot starts up. The board function checkboard() is called
4536 - CONFIG_DISPLAY_BOARDINFO_LATE
4537 Similar to the previous option, but display this information
4538 later, once stdio is running and output goes to the LCD, if
4541 - CONFIG_BOARD_SIZE_LIMIT:
4542 Maximum size of the U-Boot image. When defined, the
4543 build system checks that the actual size does not
4546 Low Level (hardware related) configuration options:
4547 ---------------------------------------------------
4549 - CONFIG_SYS_CACHELINE_SIZE:
4550 Cache Line Size of the CPU.
4552 - CONFIG_SYS_DEFAULT_IMMR:
4553 Default address of the IMMR after system reset.
4555 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4556 and RPXsuper) to be able to adjust the position of
4557 the IMMR register after a reset.
4559 - CONFIG_SYS_CCSRBAR_DEFAULT:
4560 Default (power-on reset) physical address of CCSR on Freescale
4563 - CONFIG_SYS_CCSRBAR:
4564 Virtual address of CCSR. On a 32-bit build, this is typically
4565 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4567 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4568 for cross-platform code that uses that macro instead.
4570 - CONFIG_SYS_CCSRBAR_PHYS:
4571 Physical address of CCSR. CCSR can be relocated to a new
4572 physical address, if desired. In this case, this macro should
4573 be set to that address. Otherwise, it should be set to the
4574 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4575 is typically relocated on 36-bit builds. It is recommended
4576 that this macro be defined via the _HIGH and _LOW macros:
4578 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4579 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4581 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4582 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4583 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4584 used in assembly code, so it must not contain typecasts or
4585 integer size suffixes (e.g. "ULL").
4587 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4588 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4589 used in assembly code, so it must not contain typecasts or
4590 integer size suffixes (e.g. "ULL").
4592 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4593 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4594 forced to a value that ensures that CCSR is not relocated.
4596 - Floppy Disk Support:
4597 CONFIG_SYS_FDC_DRIVE_NUMBER
4599 the default drive number (default value 0)
4601 CONFIG_SYS_ISA_IO_STRIDE
4603 defines the spacing between FDC chipset registers
4606 CONFIG_SYS_ISA_IO_OFFSET
4608 defines the offset of register from address. It
4609 depends on which part of the data bus is connected to
4610 the FDC chipset. (default value 0)
4612 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4613 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4616 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4617 fdc_hw_init() is called at the beginning of the FDC
4618 setup. fdc_hw_init() must be provided by the board
4619 source code. It is used to make hardware-dependent
4623 Most IDE controllers were designed to be connected with PCI
4624 interface. Only few of them were designed for AHB interface.
4625 When software is doing ATA command and data transfer to
4626 IDE devices through IDE-AHB controller, some additional
4627 registers accessing to these kind of IDE-AHB controller
4630 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4631 DO NOT CHANGE unless you know exactly what you're
4632 doing! (11-4) [MPC8xx/82xx systems only]
4634 - CONFIG_SYS_INIT_RAM_ADDR:
4636 Start address of memory area that can be used for
4637 initial data and stack; please note that this must be
4638 writable memory that is working WITHOUT special
4639 initialization, i. e. you CANNOT use normal RAM which
4640 will become available only after programming the
4641 memory controller and running certain initialization
4644 U-Boot uses the following memory types:
4645 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4646 - MPC824X: data cache
4647 - PPC4xx: data cache
4649 - CONFIG_SYS_GBL_DATA_OFFSET:
4651 Offset of the initial data structure in the memory
4652 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4653 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4654 data is located at the end of the available space
4655 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4656 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4657 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4658 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4661 On the MPC824X (or other systems that use the data
4662 cache for initial memory) the address chosen for
4663 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4664 point to an otherwise UNUSED address space between
4665 the top of RAM and the start of the PCI space.
4667 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4669 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4671 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4673 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4675 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4677 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4679 - CONFIG_SYS_OR_TIMING_SDRAM:
4682 - CONFIG_SYS_MAMR_PTA:
4683 periodic timer for refresh
4685 - CONFIG_SYS_DER: Debug Event Register (37-47)
4687 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4688 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4689 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4690 CONFIG_SYS_BR1_PRELIM:
4691 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4693 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4694 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4695 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4696 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4698 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4699 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4700 Machine Mode Register and Memory Periodic Timer
4701 Prescaler definitions (SDRAM timing)
4703 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4704 enable I2C microcode relocation patch (MPC8xx);
4705 define relocation offset in DPRAM [DSP2]
4707 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4708 enable SMC microcode relocation patch (MPC8xx);
4709 define relocation offset in DPRAM [SMC1]
4711 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4712 enable SPI microcode relocation patch (MPC8xx);
4713 define relocation offset in DPRAM [SCC4]
4715 - CONFIG_SYS_USE_OSCCLK:
4716 Use OSCM clock mode on MBX8xx board. Be careful,
4717 wrong setting might damage your board. Read
4718 doc/README.MBX before setting this variable!
4720 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4721 Offset of the bootmode word in DPRAM used by post
4722 (Power On Self Tests). This definition overrides
4723 #define'd default value in commproc.h resp.
4726 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4727 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4728 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4729 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4730 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4731 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4732 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4733 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4734 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4736 - CONFIG_PCI_DISABLE_PCIE:
4737 Disable PCI-Express on systems where it is supported but not
4740 - CONFIG_PCI_ENUM_ONLY
4741 Only scan through and get the devices on the buses.
4742 Don't do any setup work, presumably because someone or
4743 something has already done it, and we don't need to do it
4744 a second time. Useful for platforms that are pre-booted
4745 by coreboot or similar.
4747 - CONFIG_PCI_INDIRECT_BRIDGE:
4748 Enable support for indirect PCI bridges.
4751 Chip has SRIO or not
4754 Board has SRIO 1 port available
4757 Board has SRIO 2 port available
4759 - CONFIG_SRIO_PCIE_BOOT_MASTER
4760 Board can support master function for Boot from SRIO and PCIE
4762 - CONFIG_SYS_SRIOn_MEM_VIRT:
4763 Virtual Address of SRIO port 'n' memory region
4765 - CONFIG_SYS_SRIOn_MEM_PHYS:
4766 Physical Address of SRIO port 'n' memory region
4768 - CONFIG_SYS_SRIOn_MEM_SIZE:
4769 Size of SRIO port 'n' memory region
4771 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4772 Defined to tell the NAND controller that the NAND chip is using
4774 Not all NAND drivers use this symbol.
4775 Example of drivers that use it:
4776 - drivers/mtd/nand/ndfc.c
4777 - drivers/mtd/nand/mxc_nand.c
4779 - CONFIG_SYS_NDFC_EBC0_CFG
4780 Sets the EBC0_CFG register for the NDFC. If not defined
4781 a default value will be used.
4784 Get DDR timing information from an I2C EEPROM. Common
4785 with pluggable memory modules such as SODIMMs
4788 I2C address of the SPD EEPROM
4790 - CONFIG_SYS_SPD_BUS_NUM
4791 If SPD EEPROM is on an I2C bus other than the first
4792 one, specify here. Note that the value must resolve
4793 to something your driver can deal with.
4795 - CONFIG_SYS_DDR_RAW_TIMING
4796 Get DDR timing information from other than SPD. Common with
4797 soldered DDR chips onboard without SPD. DDR raw timing
4798 parameters are extracted from datasheet and hard-coded into
4799 header files or board specific files.
4801 - CONFIG_FSL_DDR_INTERACTIVE
4802 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4804 - CONFIG_FSL_DDR_SYNC_REFRESH
4805 Enable sync of refresh for multiple controllers.
4807 - CONFIG_FSL_DDR_BIST
4808 Enable built-in memory test for Freescale DDR controllers.
4810 - CONFIG_SYS_83XX_DDR_USES_CS0
4811 Only for 83xx systems. If specified, then DDR should
4812 be configured using CS0 and CS1 instead of CS2 and CS3.
4814 - CONFIG_ETHER_ON_FEC[12]
4815 Define to enable FEC[12] on a 8xx series processor.
4817 - CONFIG_FEC[12]_PHY
4818 Define to the hardcoded PHY address which corresponds
4819 to the given FEC; i. e.
4820 #define CONFIG_FEC1_PHY 4
4821 means that the PHY with address 4 is connected to FEC1
4823 When set to -1, means to probe for first available.
4825 - CONFIG_FEC[12]_PHY_NORXERR
4826 The PHY does not have a RXERR line (RMII only).
4827 (so program the FEC to ignore it).
4830 Enable RMII mode for all FECs.
4831 Note that this is a global option, we can't
4832 have one FEC in standard MII mode and another in RMII mode.
4834 - CONFIG_CRC32_VERIFY
4835 Add a verify option to the crc32 command.
4838 => crc32 -v <address> <count> <crc32>
4840 Where address/count indicate a memory area
4841 and crc32 is the correct crc32 which the
4845 Add the "loopw" memory command. This only takes effect if
4846 the memory commands are activated globally (CONFIG_CMD_MEM).
4849 Add the "mdc" and "mwc" memory commands. These are cyclic
4854 This command will print 4 bytes (10,11,12,13) each 500 ms.
4856 => mwc.l 100 12345678 10
4857 This command will write 12345678 to address 100 all 10 ms.
4859 This only takes effect if the memory commands are activated
4860 globally (CONFIG_CMD_MEM).
4862 - CONFIG_SKIP_LOWLEVEL_INIT
4863 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4864 low level initializations (like setting up the memory
4865 controller) are omitted and/or U-Boot does not
4866 relocate itself into RAM.
4868 Normally this variable MUST NOT be defined. The only
4869 exception is when U-Boot is loaded (to RAM) by some
4870 other boot loader or by a debugger which performs
4871 these initializations itself.
4874 Modifies the behaviour of start.S when compiling a loader
4875 that is executed before the actual U-Boot. E.g. when
4876 compiling a NAND SPL.
4879 Modifies the behaviour of start.S when compiling a loader
4880 that is executed after the SPL and before the actual U-Boot.
4881 It is loaded by the SPL.
4883 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4884 Only for 85xx systems. If this variable is specified, the section
4885 .resetvec is not kept and the section .bootpg is placed in the
4886 previous 4k of the .text section.
4888 - CONFIG_ARCH_MAP_SYSMEM
4889 Generally U-Boot (and in particular the md command) uses
4890 effective address. It is therefore not necessary to regard
4891 U-Boot address as virtual addresses that need to be translated
4892 to physical addresses. However, sandbox requires this, since
4893 it maintains its own little RAM buffer which contains all
4894 addressable memory. This option causes some memory accesses
4895 to be mapped through map_sysmem() / unmap_sysmem().
4897 - CONFIG_USE_ARCH_MEMCPY
4898 CONFIG_USE_ARCH_MEMSET
4899 If these options are used a optimized version of memcpy/memset will
4900 be used if available. These functions may be faster under some
4901 conditions but may increase the binary size.
4903 - CONFIG_X86_RESET_VECTOR
4904 If defined, the x86 reset vector code is included. This is not
4905 needed when U-Boot is running from Coreboot.
4908 Defines the MPU clock speed (in MHz).
4910 NOTE : currently only supported on AM335x platforms.
4912 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4913 Enables the RTC32K OSC on AM33xx based plattforms
4915 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4916 Option to disable subpage write in NAND driver
4917 driver that uses this:
4918 drivers/mtd/nand/davinci_nand.c
4920 Freescale QE/FMAN Firmware Support:
4921 -----------------------------------
4923 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4924 loading of "firmware", which is encoded in the QE firmware binary format.
4925 This firmware often needs to be loaded during U-Boot booting, so macros
4926 are used to identify the storage device (NOR flash, SPI, etc) and the address
4929 - CONFIG_SYS_FMAN_FW_ADDR
4930 The address in the storage device where the FMAN microcode is located. The
4931 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4934 - CONFIG_SYS_QE_FW_ADDR
4935 The address in the storage device where the QE microcode is located. The
4936 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4939 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4940 The maximum possible size of the firmware. The firmware binary format
4941 has a field that specifies the actual size of the firmware, but it
4942 might not be possible to read any part of the firmware unless some
4943 local storage is allocated to hold the entire firmware first.
4945 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4946 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4947 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4948 virtual address in NOR flash.
4950 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4951 Specifies that QE/FMAN firmware is located in NAND flash.
4952 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4954 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4955 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4956 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4958 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4959 Specifies that QE/FMAN firmware is located on the primary SPI
4960 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4962 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4963 Specifies that QE/FMAN firmware is located in the remote (master)
4964 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4965 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4966 window->master inbound window->master LAW->the ucode address in
4967 master's memory space.
4969 Freescale Layerscape Management Complex Firmware Support:
4970 ---------------------------------------------------------
4971 The Freescale Layerscape Management Complex (MC) supports the loading of
4973 This firmware often needs to be loaded during U-Boot booting, so macros
4974 are used to identify the storage device (NOR flash, SPI, etc) and the address
4977 - CONFIG_FSL_MC_ENET
4978 Enable the MC driver for Layerscape SoCs.
4980 - CONFIG_SYS_LS_MC_FW_ADDR
4981 The address in the storage device where the firmware is located. The
4982 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4985 - CONFIG_SYS_LS_MC_FW_LENGTH
4986 The maximum possible size of the firmware. The firmware binary format
4987 has a field that specifies the actual size of the firmware, but it
4988 might not be possible to read any part of the firmware unless some
4989 local storage is allocated to hold the entire firmware first.
4991 - CONFIG_SYS_LS_MC_FW_IN_NOR
4992 Specifies that MC firmware is located in NOR flash, mapped as
4993 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4994 virtual address in NOR flash.
4996 Freescale Layerscape Debug Server Support:
4997 -------------------------------------------
4998 The Freescale Layerscape Debug Server Support supports the loading of
4999 "Debug Server firmware" and triggering SP boot-rom.
5000 This firmware often needs to be loaded during U-Boot booting.
5002 - CONFIG_FSL_DEBUG_SERVER
5003 Enable the Debug Server for Layerscape SoCs.
5005 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
5006 Define minimum DDR size required for debug server image
5008 - CONFIG_SYS_MC_RSV_MEM_ALIGN
5009 Define alignment of reserved memory MC requires
5014 In order to achieve reproducible builds, timestamps used in the U-Boot build
5015 process have to be set to a fixed value.
5017 This is done using the SOURCE_DATE_EPOCH environment variable.
5018 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5019 option for U-Boot or an environment variable in U-Boot.
5021 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5023 Building the Software:
5024 ======================
5026 Building U-Boot has been tested in several native build environments
5027 and in many different cross environments. Of course we cannot support
5028 all possibly existing versions of cross development tools in all
5029 (potentially obsolete) versions. In case of tool chain problems we
5030 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5031 which is extensively used to build and test U-Boot.
5033 If you are not using a native environment, it is assumed that you
5034 have GNU cross compiling tools available in your path. In this case,
5035 you must set the environment variable CROSS_COMPILE in your shell.
5036 Note that no changes to the Makefile or any other source files are
5037 necessary. For example using the ELDK on a 4xx CPU, please enter:
5039 $ CROSS_COMPILE=ppc_4xx-
5040 $ export CROSS_COMPILE
5042 Note: If you wish to generate Windows versions of the utilities in
5043 the tools directory you can use the MinGW toolchain
5044 (http://www.mingw.org). Set your HOST tools to the MinGW
5045 toolchain and execute 'make tools'. For example:
5047 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5049 Binaries such as tools/mkimage.exe will be created which can
5050 be executed on computers running Windows.
5052 U-Boot is intended to be simple to build. After installing the
5053 sources you must configure U-Boot for one specific board type. This
5058 where "NAME_defconfig" is the name of one of the existing configu-
5059 rations; see boards.cfg for supported names.
5061 Note: for some board special configuration names may exist; check if
5062 additional information is available from the board vendor; for
5063 instance, the TQM823L systems are available without (standard)
5064 or with LCD support. You can select such additional "features"
5065 when choosing the configuration, i. e.
5067 make TQM823L_defconfig
5068 - will configure for a plain TQM823L, i. e. no LCD support
5070 make TQM823L_LCD_defconfig
5071 - will configure for a TQM823L with U-Boot console on LCD
5076 Finally, type "make all", and you should get some working U-Boot
5077 images ready for download to / installation on your system:
5079 - "u-boot.bin" is a raw binary image
5080 - "u-boot" is an image in ELF binary format
5081 - "u-boot.srec" is in Motorola S-Record format
5083 By default the build is performed locally and the objects are saved
5084 in the source directory. One of the two methods can be used to change
5085 this behavior and build U-Boot to some external directory:
5087 1. Add O= to the make command line invocations:
5089 make O=/tmp/build distclean
5090 make O=/tmp/build NAME_defconfig
5091 make O=/tmp/build all
5093 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5095 export KBUILD_OUTPUT=/tmp/build
5100 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5104 Please be aware that the Makefiles assume you are using GNU make, so
5105 for instance on NetBSD you might need to use "gmake" instead of
5109 If the system board that you have is not listed, then you will need
5110 to port U-Boot to your hardware platform. To do this, follow these
5113 1. Create a new directory to hold your board specific code. Add any
5114 files you need. In your board directory, you will need at least
5115 the "Makefile" and a "<board>.c".
5116 2. Create a new configuration file "include/configs/<board>.h" for
5118 3. If you're porting U-Boot to a new CPU, then also create a new
5119 directory to hold your CPU specific code. Add any files you need.
5120 4. Run "make <board>_defconfig" with your new name.
5121 5. Type "make", and you should get a working "u-boot.srec" file
5122 to be installed on your target system.
5123 6. Debug and solve any problems that might arise.
5124 [Of course, this last step is much harder than it sounds.]
5127 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5128 ==============================================================
5130 If you have modified U-Boot sources (for instance added a new board
5131 or support for new devices, a new CPU, etc.) you are expected to
5132 provide feedback to the other developers. The feedback normally takes
5133 the form of a "patch", i. e. a context diff against a certain (latest
5134 official or latest in the git repository) version of U-Boot sources.
5136 But before you submit such a patch, please verify that your modifi-
5137 cation did not break existing code. At least make sure that *ALL* of
5138 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5139 just run the "MAKEALL" script, which will configure and build U-Boot
5140 for ALL supported system. Be warned, this will take a while. You can
5141 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5142 environment variable to the script, i. e. to use the ELDK cross tools
5145 CROSS_COMPILE=ppc_8xx- MAKEALL
5147 or to build on a native PowerPC system you can type
5149 CROSS_COMPILE=' ' MAKEALL
5151 When using the MAKEALL script, the default behaviour is to build
5152 U-Boot in the source directory. This location can be changed by
5153 setting the BUILD_DIR environment variable. Also, for each target
5154 built, the MAKEALL script saves two log files (<target>.ERR and
5155 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5156 location can be changed by setting the MAKEALL_LOGDIR environment
5157 variable. For example:
5159 export BUILD_DIR=/tmp/build
5160 export MAKEALL_LOGDIR=/tmp/log
5161 CROSS_COMPILE=ppc_8xx- MAKEALL
5163 With the above settings build objects are saved in the /tmp/build,
5164 log files are saved in the /tmp/log and the source tree remains clean
5165 during the whole build process.
5168 See also "U-Boot Porting Guide" below.
5171 Monitor Commands - Overview:
5172 ============================
5174 go - start application at address 'addr'
5175 run - run commands in an environment variable
5176 bootm - boot application image from memory
5177 bootp - boot image via network using BootP/TFTP protocol
5178 bootz - boot zImage from memory
5179 tftpboot- boot image via network using TFTP protocol
5180 and env variables "ipaddr" and "serverip"
5181 (and eventually "gatewayip")
5182 tftpput - upload a file via network using TFTP protocol
5183 rarpboot- boot image via network using RARP/TFTP protocol
5184 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5185 loads - load S-Record file over serial line
5186 loadb - load binary file over serial line (kermit mode)
5188 mm - memory modify (auto-incrementing)
5189 nm - memory modify (constant address)
5190 mw - memory write (fill)
5192 cmp - memory compare
5193 crc32 - checksum calculation
5194 i2c - I2C sub-system
5195 sspi - SPI utility commands
5196 base - print or set address offset
5197 printenv- print environment variables
5198 setenv - set environment variables
5199 saveenv - save environment variables to persistent storage
5200 protect - enable or disable FLASH write protection
5201 erase - erase FLASH memory
5202 flinfo - print FLASH memory information
5203 nand - NAND memory operations (see doc/README.nand)
5204 bdinfo - print Board Info structure
5205 iminfo - print header information for application image
5206 coninfo - print console devices and informations
5207 ide - IDE sub-system
5208 loop - infinite loop on address range
5209 loopw - infinite write loop on address range
5210 mtest - simple RAM test
5211 icache - enable or disable instruction cache
5212 dcache - enable or disable data cache
5213 reset - Perform RESET of the CPU
5214 echo - echo args to console
5215 version - print monitor version
5216 help - print online help
5217 ? - alias for 'help'
5220 Monitor Commands - Detailed Description:
5221 ========================================
5225 For now: just type "help <command>".
5228 Environment Variables:
5229 ======================
5231 U-Boot supports user configuration using Environment Variables which
5232 can be made persistent by saving to Flash memory.
5234 Environment Variables are set using "setenv", printed using
5235 "printenv", and saved to Flash using "saveenv". Using "setenv"
5236 without a value can be used to delete a variable from the
5237 environment. As long as you don't save the environment you are
5238 working with an in-memory copy. In case the Flash area containing the
5239 environment is erased by accident, a default environment is provided.
5241 Some configuration options can be set using Environment Variables.
5243 List of environment variables (most likely not complete):
5245 baudrate - see CONFIG_BAUDRATE
5247 bootdelay - see CONFIG_BOOTDELAY
5249 bootcmd - see CONFIG_BOOTCOMMAND
5251 bootargs - Boot arguments when booting an RTOS image
5253 bootfile - Name of the image to load with TFTP
5255 bootm_low - Memory range available for image processing in the bootm
5256 command can be restricted. This variable is given as
5257 a hexadecimal number and defines lowest address allowed
5258 for use by the bootm command. See also "bootm_size"
5259 environment variable. Address defined by "bootm_low" is
5260 also the base of the initial memory mapping for the Linux
5261 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5264 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5265 This variable is given as a hexadecimal number and it
5266 defines the size of the memory region starting at base
5267 address bootm_low that is accessible by the Linux kernel
5268 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5269 as the default value if it is defined, and bootm_size is
5272 bootm_size - Memory range available for image processing in the bootm
5273 command can be restricted. This variable is given as
5274 a hexadecimal number and defines the size of the region
5275 allowed for use by the bootm command. See also "bootm_low"
5276 environment variable.
5278 updatefile - Location of the software update file on a TFTP server, used
5279 by the automatic software update feature. Please refer to
5280 documentation in doc/README.update for more details.
5282 autoload - if set to "no" (any string beginning with 'n'),
5283 "bootp" will just load perform a lookup of the
5284 configuration from the BOOTP server, but not try to
5285 load any image using TFTP
5287 autostart - if set to "yes", an image loaded using the "bootp",
5288 "rarpboot", "tftpboot" or "diskboot" commands will
5289 be automatically started (by internally calling
5292 If set to "no", a standalone image passed to the
5293 "bootm" command will be copied to the load address
5294 (and eventually uncompressed), but NOT be started.
5295 This can be used to load and uncompress arbitrary
5298 fdt_high - if set this restricts the maximum address that the
5299 flattened device tree will be copied into upon boot.
5300 For example, if you have a system with 1 GB memory
5301 at physical address 0x10000000, while Linux kernel
5302 only recognizes the first 704 MB as low memory, you
5303 may need to set fdt_high as 0x3C000000 to have the
5304 device tree blob be copied to the maximum address
5305 of the 704 MB low memory, so that Linux kernel can
5306 access it during the boot procedure.
5308 If this is set to the special value 0xFFFFFFFF then
5309 the fdt will not be copied at all on boot. For this
5310 to work it must reside in writable memory, have
5311 sufficient padding on the end of it for u-boot to
5312 add the information it needs into it, and the memory
5313 must be accessible by the kernel.
5315 fdtcontroladdr- if set this is the address of the control flattened
5316 device tree used by U-Boot when CONFIG_OF_CONTROL is
5319 i2cfast - (PPC405GP|PPC405EP only)
5320 if set to 'y' configures Linux I2C driver for fast
5321 mode (400kHZ). This environment variable is used in
5322 initialization code. So, for changes to be effective
5323 it must be saved and board must be reset.
5325 initrd_high - restrict positioning of initrd images:
5326 If this variable is not set, initrd images will be
5327 copied to the highest possible address in RAM; this
5328 is usually what you want since it allows for
5329 maximum initrd size. If for some reason you want to
5330 make sure that the initrd image is loaded below the
5331 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5332 variable to a value of "no" or "off" or "0".
5333 Alternatively, you can set it to a maximum upper
5334 address to use (U-Boot will still check that it
5335 does not overwrite the U-Boot stack and data).
5337 For instance, when you have a system with 16 MB
5338 RAM, and want to reserve 4 MB from use by Linux,
5339 you can do this by adding "mem=12M" to the value of
5340 the "bootargs" variable. However, now you must make
5341 sure that the initrd image is placed in the first
5342 12 MB as well - this can be done with
5344 setenv initrd_high 00c00000
5346 If you set initrd_high to 0xFFFFFFFF, this is an
5347 indication to U-Boot that all addresses are legal
5348 for the Linux kernel, including addresses in flash
5349 memory. In this case U-Boot will NOT COPY the
5350 ramdisk at all. This may be useful to reduce the
5351 boot time on your system, but requires that this
5352 feature is supported by your Linux kernel.
5354 ipaddr - IP address; needed for tftpboot command
5356 loadaddr - Default load address for commands like "bootp",
5357 "rarpboot", "tftpboot", "loadb" or "diskboot"
5359 loads_echo - see CONFIG_LOADS_ECHO
5361 serverip - TFTP server IP address; needed for tftpboot command
5363 bootretry - see CONFIG_BOOT_RETRY_TIME
5365 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5367 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5369 ethprime - controls which interface is used first.
5371 ethact - controls which interface is currently active.
5372 For example you can do the following
5374 => setenv ethact FEC
5375 => ping 192.168.0.1 # traffic sent on FEC
5376 => setenv ethact SCC
5377 => ping 10.0.0.1 # traffic sent on SCC
5379 ethrotate - When set to "no" U-Boot does not go through all
5380 available network interfaces.
5381 It just stays at the currently selected interface.
5383 netretry - When set to "no" each network operation will
5384 either succeed or fail without retrying.
5385 When set to "once" the network operation will
5386 fail when all the available network interfaces
5387 are tried once without success.
5388 Useful on scripts which control the retry operation
5391 npe_ucode - set load address for the NPE microcode
5393 silent_linux - If set then Linux will be told to boot silently, by
5394 changing the console to be empty. If "yes" it will be
5395 made silent. If "no" it will not be made silent. If
5396 unset, then it will be made silent if the U-Boot console
5399 tftpsrcp - If this is set, the value is used for TFTP's
5402 tftpdstp - If this is set, the value is used for TFTP's UDP
5403 destination port instead of the Well Know Port 69.
5405 tftpblocksize - Block size to use for TFTP transfers; if not set,
5406 we use the TFTP server's default block size
5408 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5409 seconds, minimum value is 1000 = 1 second). Defines
5410 when a packet is considered to be lost so it has to
5411 be retransmitted. The default is 5000 = 5 seconds.
5412 Lowering this value may make downloads succeed
5413 faster in networks with high packet loss rates or
5414 with unreliable TFTP servers.
5416 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5417 unit, minimum value = 0). Defines how many timeouts
5418 can happen during a single file transfer before that
5419 transfer is aborted. The default is 10, and 0 means
5420 'no timeouts allowed'. Increasing this value may help
5421 downloads succeed with high packet loss rates, or with
5422 unreliable TFTP servers or client hardware.
5424 vlan - When set to a value < 4095 the traffic over
5425 Ethernet is encapsulated/received over 802.1q
5428 The following image location variables contain the location of images
5429 used in booting. The "Image" column gives the role of the image and is
5430 not an environment variable name. The other columns are environment
5431 variable names. "File Name" gives the name of the file on a TFTP
5432 server, "RAM Address" gives the location in RAM the image will be
5433 loaded to, and "Flash Location" gives the image's address in NOR
5434 flash or offset in NAND flash.
5436 *Note* - these variables don't have to be defined for all boards, some
5437 boards currently use other variables for these purposes, and some
5438 boards use these variables for other purposes.
5440 Image File Name RAM Address Flash Location
5441 ----- --------- ----------- --------------
5442 u-boot u-boot u-boot_addr_r u-boot_addr
5443 Linux kernel bootfile kernel_addr_r kernel_addr
5444 device tree blob fdtfile fdt_addr_r fdt_addr
5445 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5447 The following environment variables may be used and automatically
5448 updated by the network boot commands ("bootp" and "rarpboot"),
5449 depending the information provided by your boot server:
5451 bootfile - see above
5452 dnsip - IP address of your Domain Name Server
5453 dnsip2 - IP address of your secondary Domain Name Server
5454 gatewayip - IP address of the Gateway (Router) to use
5455 hostname - Target hostname
5457 netmask - Subnet Mask
5458 rootpath - Pathname of the root filesystem on the NFS server
5459 serverip - see above
5462 There are two special Environment Variables:
5464 serial# - contains hardware identification information such
5465 as type string and/or serial number
5466 ethaddr - Ethernet address
5468 These variables can be set only once (usually during manufacturing of
5469 the board). U-Boot refuses to delete or overwrite these variables
5470 once they have been set once.
5473 Further special Environment Variables:
5475 ver - Contains the U-Boot version string as printed
5476 with the "version" command. This variable is
5477 readonly (see CONFIG_VERSION_VARIABLE).
5480 Please note that changes to some configuration parameters may take
5481 only effect after the next boot (yes, that's just like Windoze :-).
5484 Callback functions for environment variables:
5485 ---------------------------------------------
5487 For some environment variables, the behavior of u-boot needs to change
5488 when their values are changed. This functionality allows functions to
5489 be associated with arbitrary variables. On creation, overwrite, or
5490 deletion, the callback will provide the opportunity for some side
5491 effect to happen or for the change to be rejected.
5493 The callbacks are named and associated with a function using the
5494 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5496 These callbacks are associated with variables in one of two ways. The
5497 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5498 in the board configuration to a string that defines a list of
5499 associations. The list must be in the following format:
5501 entry = variable_name[:callback_name]
5504 If the callback name is not specified, then the callback is deleted.
5505 Spaces are also allowed anywhere in the list.
5507 Callbacks can also be associated by defining the ".callbacks" variable
5508 with the same list format above. Any association in ".callbacks" will
5509 override any association in the static list. You can define
5510 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5511 ".callbacks" environment variable in the default or embedded environment.
5513 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5514 regular expression. This allows multiple variables to be connected to
5515 the same callback without explicitly listing them all out.
5518 Command Line Parsing:
5519 =====================
5521 There are two different command line parsers available with U-Boot:
5522 the old "simple" one, and the much more powerful "hush" shell:
5524 Old, simple command line parser:
5525 --------------------------------
5527 - supports environment variables (through setenv / saveenv commands)
5528 - several commands on one line, separated by ';'
5529 - variable substitution using "... ${name} ..." syntax
5530 - special characters ('$', ';') can be escaped by prefixing with '\',
5532 setenv bootcmd bootm \${address}
5533 - You can also escape text by enclosing in single apostrophes, for example:
5534 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5539 - similar to Bourne shell, with control structures like
5540 if...then...else...fi, for...do...done; while...do...done,
5541 until...do...done, ...
5542 - supports environment ("global") variables (through setenv / saveenv
5543 commands) and local shell variables (through standard shell syntax
5544 "name=value"); only environment variables can be used with "run"
5550 (1) If a command line (or an environment variable executed by a "run"
5551 command) contains several commands separated by semicolon, and
5552 one of these commands fails, then the remaining commands will be
5555 (2) If you execute several variables with one call to run (i. e.
5556 calling run with a list of variables as arguments), any failing
5557 command will cause "run" to terminate, i. e. the remaining
5558 variables are not executed.
5560 Note for Redundant Ethernet Interfaces:
5561 =======================================
5563 Some boards come with redundant Ethernet interfaces; U-Boot supports
5564 such configurations and is capable of automatic selection of a
5565 "working" interface when needed. MAC assignment works as follows:
5567 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5568 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5569 "eth1addr" (=>eth1), "eth2addr", ...
5571 If the network interface stores some valid MAC address (for instance
5572 in SROM), this is used as default address if there is NO correspon-
5573 ding setting in the environment; if the corresponding environment
5574 variable is set, this overrides the settings in the card; that means:
5576 o If the SROM has a valid MAC address, and there is no address in the
5577 environment, the SROM's address is used.
5579 o If there is no valid address in the SROM, and a definition in the
5580 environment exists, then the value from the environment variable is
5583 o If both the SROM and the environment contain a MAC address, and
5584 both addresses are the same, this MAC address is used.
5586 o If both the SROM and the environment contain a MAC address, and the
5587 addresses differ, the value from the environment is used and a
5590 o If neither SROM nor the environment contain a MAC address, an error
5591 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5592 a random, locally-assigned MAC is used.
5594 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5595 will be programmed into hardware as part of the initialization process. This
5596 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5597 The naming convention is as follows:
5598 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5603 U-Boot is capable of booting (and performing other auxiliary operations on)
5604 images in two formats:
5606 New uImage format (FIT)
5607 -----------------------
5609 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5610 to Flattened Device Tree). It allows the use of images with multiple
5611 components (several kernels, ramdisks, etc.), with contents protected by
5612 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5618 Old image format is based on binary files which can be basically anything,
5619 preceded by a special header; see the definitions in include/image.h for
5620 details; basically, the header defines the following image properties:
5622 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5623 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5624 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5625 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5627 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5628 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5629 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5630 * Compression Type (uncompressed, gzip, bzip2)
5636 The header is marked by a special Magic Number, and both the header
5637 and the data portions of the image are secured against corruption by
5644 Although U-Boot should support any OS or standalone application
5645 easily, the main focus has always been on Linux during the design of
5648 U-Boot includes many features that so far have been part of some
5649 special "boot loader" code within the Linux kernel. Also, any
5650 "initrd" images to be used are no longer part of one big Linux image;
5651 instead, kernel and "initrd" are separate images. This implementation
5652 serves several purposes:
5654 - the same features can be used for other OS or standalone
5655 applications (for instance: using compressed images to reduce the
5656 Flash memory footprint)
5658 - it becomes much easier to port new Linux kernel versions because
5659 lots of low-level, hardware dependent stuff are done by U-Boot
5661 - the same Linux kernel image can now be used with different "initrd"
5662 images; of course this also means that different kernel images can
5663 be run with the same "initrd". This makes testing easier (you don't
5664 have to build a new "zImage.initrd" Linux image when you just
5665 change a file in your "initrd"). Also, a field-upgrade of the
5666 software is easier now.
5672 Porting Linux to U-Boot based systems:
5673 ---------------------------------------
5675 U-Boot cannot save you from doing all the necessary modifications to
5676 configure the Linux device drivers for use with your target hardware
5677 (no, we don't intend to provide a full virtual machine interface to
5680 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5682 Just make sure your machine specific header file (for instance
5683 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5684 Information structure as we define in include/asm-<arch>/u-boot.h,
5685 and make sure that your definition of IMAP_ADDR uses the same value
5686 as your U-Boot configuration in CONFIG_SYS_IMMR.
5688 Note that U-Boot now has a driver model, a unified model for drivers.
5689 If you are adding a new driver, plumb it into driver model. If there
5690 is no uclass available, you are encouraged to create one. See
5694 Configuring the Linux kernel:
5695 -----------------------------
5697 No specific requirements for U-Boot. Make sure you have some root
5698 device (initial ramdisk, NFS) for your target system.
5701 Building a Linux Image:
5702 -----------------------
5704 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5705 not used. If you use recent kernel source, a new build target
5706 "uImage" will exist which automatically builds an image usable by
5707 U-Boot. Most older kernels also have support for a "pImage" target,
5708 which was introduced for our predecessor project PPCBoot and uses a
5709 100% compatible format.
5713 make TQM850L_defconfig
5718 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5719 encapsulate a compressed Linux kernel image with header information,
5720 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5722 * build a standard "vmlinux" kernel image (in ELF binary format):
5724 * convert the kernel into a raw binary image:
5726 ${CROSS_COMPILE}-objcopy -O binary \
5727 -R .note -R .comment \
5728 -S vmlinux linux.bin
5730 * compress the binary image:
5734 * package compressed binary image for U-Boot:
5736 mkimage -A ppc -O linux -T kernel -C gzip \
5737 -a 0 -e 0 -n "Linux Kernel Image" \
5738 -d linux.bin.gz uImage
5741 The "mkimage" tool can also be used to create ramdisk images for use
5742 with U-Boot, either separated from the Linux kernel image, or
5743 combined into one file. "mkimage" encapsulates the images with a 64
5744 byte header containing information about target architecture,
5745 operating system, image type, compression method, entry points, time
5746 stamp, CRC32 checksums, etc.
5748 "mkimage" can be called in two ways: to verify existing images and
5749 print the header information, or to build new images.
5751 In the first form (with "-l" option) mkimage lists the information
5752 contained in the header of an existing U-Boot image; this includes
5753 checksum verification:
5755 tools/mkimage -l image
5756 -l ==> list image header information
5758 The second form (with "-d" option) is used to build a U-Boot image
5759 from a "data file" which is used as image payload:
5761 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5762 -n name -d data_file image
5763 -A ==> set architecture to 'arch'
5764 -O ==> set operating system to 'os'
5765 -T ==> set image type to 'type'
5766 -C ==> set compression type 'comp'
5767 -a ==> set load address to 'addr' (hex)
5768 -e ==> set entry point to 'ep' (hex)
5769 -n ==> set image name to 'name'
5770 -d ==> use image data from 'datafile'
5772 Right now, all Linux kernels for PowerPC systems use the same load
5773 address (0x00000000), but the entry point address depends on the
5776 - 2.2.x kernels have the entry point at 0x0000000C,
5777 - 2.3.x and later kernels have the entry point at 0x00000000.
5779 So a typical call to build a U-Boot image would read:
5781 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5782 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5783 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5784 > examples/uImage.TQM850L
5785 Image Name: 2.4.4 kernel for TQM850L
5786 Created: Wed Jul 19 02:34:59 2000
5787 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5788 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5789 Load Address: 0x00000000
5790 Entry Point: 0x00000000
5792 To verify the contents of the image (or check for corruption):
5794 -> tools/mkimage -l examples/uImage.TQM850L
5795 Image Name: 2.4.4 kernel for TQM850L
5796 Created: Wed Jul 19 02:34:59 2000
5797 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5798 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5799 Load Address: 0x00000000
5800 Entry Point: 0x00000000
5802 NOTE: for embedded systems where boot time is critical you can trade
5803 speed for memory and install an UNCOMPRESSED image instead: this
5804 needs more space in Flash, but boots much faster since it does not
5805 need to be uncompressed:
5807 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5808 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5809 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5810 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5811 > examples/uImage.TQM850L-uncompressed
5812 Image Name: 2.4.4 kernel for TQM850L
5813 Created: Wed Jul 19 02:34:59 2000
5814 Image Type: PowerPC Linux Kernel Image (uncompressed)
5815 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5816 Load Address: 0x00000000
5817 Entry Point: 0x00000000
5820 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5821 when your kernel is intended to use an initial ramdisk:
5823 -> tools/mkimage -n 'Simple Ramdisk Image' \
5824 > -A ppc -O linux -T ramdisk -C gzip \
5825 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5826 Image Name: Simple Ramdisk Image
5827 Created: Wed Jan 12 14:01:50 2000
5828 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5829 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5830 Load Address: 0x00000000
5831 Entry Point: 0x00000000
5833 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5834 option performs the converse operation of the mkimage's second form (the "-d"
5835 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5838 tools/dumpimage -i image -T type -p position data_file
5839 -i ==> extract from the 'image' a specific 'data_file'
5840 -T ==> set image type to 'type'
5841 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5844 Installing a Linux Image:
5845 -------------------------
5847 To downloading a U-Boot image over the serial (console) interface,
5848 you must convert the image to S-Record format:
5850 objcopy -I binary -O srec examples/image examples/image.srec
5852 The 'objcopy' does not understand the information in the U-Boot
5853 image header, so the resulting S-Record file will be relative to
5854 address 0x00000000. To load it to a given address, you need to
5855 specify the target address as 'offset' parameter with the 'loads'
5858 Example: install the image to address 0x40100000 (which on the
5859 TQM8xxL is in the first Flash bank):
5861 => erase 40100000 401FFFFF
5867 ## Ready for S-Record download ...
5868 ~>examples/image.srec
5869 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5871 15989 15990 15991 15992
5872 [file transfer complete]
5874 ## Start Addr = 0x00000000
5877 You can check the success of the download using the 'iminfo' command;
5878 this includes a checksum verification so you can be sure no data
5879 corruption happened:
5883 ## Checking Image at 40100000 ...
5884 Image Name: 2.2.13 for initrd on TQM850L
5885 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5886 Data Size: 335725 Bytes = 327 kB = 0 MB
5887 Load Address: 00000000
5888 Entry Point: 0000000c
5889 Verifying Checksum ... OK
5895 The "bootm" command is used to boot an application that is stored in
5896 memory (RAM or Flash). In case of a Linux kernel image, the contents
5897 of the "bootargs" environment variable is passed to the kernel as
5898 parameters. You can check and modify this variable using the
5899 "printenv" and "setenv" commands:
5902 => printenv bootargs
5903 bootargs=root=/dev/ram
5905 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5907 => printenv bootargs
5908 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5911 ## Booting Linux kernel at 40020000 ...
5912 Image Name: 2.2.13 for NFS on TQM850L
5913 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5914 Data Size: 381681 Bytes = 372 kB = 0 MB
5915 Load Address: 00000000
5916 Entry Point: 0000000c
5917 Verifying Checksum ... OK
5918 Uncompressing Kernel Image ... OK
5919 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
5920 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5921 time_init: decrementer frequency = 187500000/60
5922 Calibrating delay loop... 49.77 BogoMIPS
5923 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5926 If you want to boot a Linux kernel with initial RAM disk, you pass
5927 the memory addresses of both the kernel and the initrd image (PPBCOOT
5928 format!) to the "bootm" command:
5930 => imi 40100000 40200000
5932 ## Checking Image at 40100000 ...
5933 Image Name: 2.2.13 for initrd on TQM850L
5934 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5935 Data Size: 335725 Bytes = 327 kB = 0 MB
5936 Load Address: 00000000
5937 Entry Point: 0000000c
5938 Verifying Checksum ... OK
5940 ## Checking Image at 40200000 ...
5941 Image Name: Simple Ramdisk Image
5942 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5943 Data Size: 566530 Bytes = 553 kB = 0 MB
5944 Load Address: 00000000
5945 Entry Point: 00000000
5946 Verifying Checksum ... OK
5948 => bootm 40100000 40200000
5949 ## Booting Linux kernel at 40100000 ...
5950 Image Name: 2.2.13 for initrd on TQM850L
5951 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5952 Data Size: 335725 Bytes = 327 kB = 0 MB
5953 Load Address: 00000000
5954 Entry Point: 0000000c
5955 Verifying Checksum ... OK
5956 Uncompressing Kernel Image ... OK
5957 ## Loading RAMDisk Image at 40200000 ...
5958 Image Name: Simple Ramdisk Image
5959 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5960 Data Size: 566530 Bytes = 553 kB = 0 MB
5961 Load Address: 00000000
5962 Entry Point: 00000000
5963 Verifying Checksum ... OK
5964 Loading Ramdisk ... OK
5965 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
5966 Boot arguments: root=/dev/ram
5967 time_init: decrementer frequency = 187500000/60
5968 Calibrating delay loop... 49.77 BogoMIPS
5970 RAMDISK: Compressed image found at block 0
5971 VFS: Mounted root (ext2 filesystem).
5975 Boot Linux and pass a flat device tree:
5978 First, U-Boot must be compiled with the appropriate defines. See the section
5979 titled "Linux Kernel Interface" above for a more in depth explanation. The
5980 following is an example of how to start a kernel and pass an updated
5986 oft=oftrees/mpc8540ads.dtb
5987 => tftp $oftaddr $oft
5988 Speed: 1000, full duplex
5990 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5991 Filename 'oftrees/mpc8540ads.dtb'.
5992 Load address: 0x300000
5995 Bytes transferred = 4106 (100a hex)
5996 => tftp $loadaddr $bootfile
5997 Speed: 1000, full duplex
5999 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
6001 Load address: 0x200000
6002 Loading:############
6004 Bytes transferred = 1029407 (fb51f hex)
6009 => bootm $loadaddr - $oftaddr
6010 ## Booting image at 00200000 ...
6011 Image Name: Linux-2.6.17-dirty
6012 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6013 Data Size: 1029343 Bytes = 1005.2 kB
6014 Load Address: 00000000
6015 Entry Point: 00000000
6016 Verifying Checksum ... OK
6017 Uncompressing Kernel Image ... OK
6018 Booting using flat device tree at 0x300000
6019 Using MPC85xx ADS machine description
6020 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6024 More About U-Boot Image Types:
6025 ------------------------------
6027 U-Boot supports the following image types:
6029 "Standalone Programs" are directly runnable in the environment
6030 provided by U-Boot; it is expected that (if they behave
6031 well) you can continue to work in U-Boot after return from
6032 the Standalone Program.
6033 "OS Kernel Images" are usually images of some Embedded OS which
6034 will take over control completely. Usually these programs
6035 will install their own set of exception handlers, device
6036 drivers, set up the MMU, etc. - this means, that you cannot
6037 expect to re-enter U-Boot except by resetting the CPU.
6038 "RAMDisk Images" are more or less just data blocks, and their
6039 parameters (address, size) are passed to an OS kernel that is
6041 "Multi-File Images" contain several images, typically an OS
6042 (Linux) kernel image and one or more data images like
6043 RAMDisks. This construct is useful for instance when you want
6044 to boot over the network using BOOTP etc., where the boot
6045 server provides just a single image file, but you want to get
6046 for instance an OS kernel and a RAMDisk image.
6048 "Multi-File Images" start with a list of image sizes, each
6049 image size (in bytes) specified by an "uint32_t" in network
6050 byte order. This list is terminated by an "(uint32_t)0".
6051 Immediately after the terminating 0 follow the images, one by
6052 one, all aligned on "uint32_t" boundaries (size rounded up to
6053 a multiple of 4 bytes).
6055 "Firmware Images" are binary images containing firmware (like
6056 U-Boot or FPGA images) which usually will be programmed to
6059 "Script files" are command sequences that will be executed by
6060 U-Boot's command interpreter; this feature is especially
6061 useful when you configure U-Boot to use a real shell (hush)
6062 as command interpreter.
6064 Booting the Linux zImage:
6065 -------------------------
6067 On some platforms, it's possible to boot Linux zImage. This is done
6068 using the "bootz" command. The syntax of "bootz" command is the same
6069 as the syntax of "bootm" command.
6071 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6072 kernel with raw initrd images. The syntax is slightly different, the
6073 address of the initrd must be augmented by it's size, in the following
6074 format: "<initrd addres>:<initrd size>".
6080 One of the features of U-Boot is that you can dynamically load and
6081 run "standalone" applications, which can use some resources of
6082 U-Boot like console I/O functions or interrupt services.
6084 Two simple examples are included with the sources:
6089 'examples/hello_world.c' contains a small "Hello World" Demo
6090 application; it is automatically compiled when you build U-Boot.
6091 It's configured to run at address 0x00040004, so you can play with it
6095 ## Ready for S-Record download ...
6096 ~>examples/hello_world.srec
6097 1 2 3 4 5 6 7 8 9 10 11 ...
6098 [file transfer complete]
6100 ## Start Addr = 0x00040004
6102 => go 40004 Hello World! This is a test.
6103 ## Starting application at 0x00040004 ...
6114 Hit any key to exit ...
6116 ## Application terminated, rc = 0x0
6118 Another example, which demonstrates how to register a CPM interrupt
6119 handler with the U-Boot code, can be found in 'examples/timer.c'.
6120 Here, a CPM timer is set up to generate an interrupt every second.
6121 The interrupt service routine is trivial, just printing a '.'
6122 character, but this is just a demo program. The application can be
6123 controlled by the following keys:
6125 ? - print current values og the CPM Timer registers
6126 b - enable interrupts and start timer
6127 e - stop timer and disable interrupts
6128 q - quit application
6131 ## Ready for S-Record download ...
6132 ~>examples/timer.srec
6133 1 2 3 4 5 6 7 8 9 10 11 ...
6134 [file transfer complete]
6136 ## Start Addr = 0x00040004
6139 ## Starting application at 0x00040004 ...
6142 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6145 [q, b, e, ?] Set interval 1000000 us
6148 [q, b, e, ?] ........
6149 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6152 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6155 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6158 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6160 [q, b, e, ?] ...Stopping timer
6162 [q, b, e, ?] ## Application terminated, rc = 0x0
6168 Over time, many people have reported problems when trying to use the
6169 "minicom" terminal emulation program for serial download. I (wd)
6170 consider minicom to be broken, and recommend not to use it. Under
6171 Unix, I recommend to use C-Kermit for general purpose use (and
6172 especially for kermit binary protocol download ("loadb" command), and
6173 use "cu" for S-Record download ("loads" command). See
6174 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6175 for help with kermit.
6178 Nevertheless, if you absolutely want to use it try adding this
6179 configuration to your "File transfer protocols" section:
6181 Name Program Name U/D FullScr IO-Red. Multi
6182 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6183 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6189 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6190 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6192 Building requires a cross environment; it is known to work on
6193 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6194 need gmake since the Makefiles are not compatible with BSD make).
6195 Note that the cross-powerpc package does not install include files;
6196 attempting to build U-Boot will fail because <machine/ansi.h> is
6197 missing. This file has to be installed and patched manually:
6199 # cd /usr/pkg/cross/powerpc-netbsd/include
6201 # ln -s powerpc machine
6202 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6203 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6205 Native builds *don't* work due to incompatibilities between native
6206 and U-Boot include files.
6208 Booting assumes that (the first part of) the image booted is a
6209 stage-2 loader which in turn loads and then invokes the kernel
6210 proper. Loader sources will eventually appear in the NetBSD source
6211 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6212 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6215 Implementation Internals:
6216 =========================
6218 The following is not intended to be a complete description of every
6219 implementation detail. However, it should help to understand the
6220 inner workings of U-Boot and make it easier to port it to custom
6224 Initial Stack, Global Data:
6225 ---------------------------
6227 The implementation of U-Boot is complicated by the fact that U-Boot
6228 starts running out of ROM (flash memory), usually without access to
6229 system RAM (because the memory controller is not initialized yet).
6230 This means that we don't have writable Data or BSS segments, and BSS
6231 is not initialized as zero. To be able to get a C environment working
6232 at all, we have to allocate at least a minimal stack. Implementation
6233 options for this are defined and restricted by the CPU used: Some CPU
6234 models provide on-chip memory (like the IMMR area on MPC8xx and
6235 MPC826x processors), on others (parts of) the data cache can be
6236 locked as (mis-) used as memory, etc.
6238 Chris Hallinan posted a good summary of these issues to the
6239 U-Boot mailing list:
6241 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6242 From: "Chris Hallinan" <clh@net1plus.com>
6243 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6246 Correct me if I'm wrong, folks, but the way I understand it
6247 is this: Using DCACHE as initial RAM for Stack, etc, does not
6248 require any physical RAM backing up the cache. The cleverness
6249 is that the cache is being used as a temporary supply of
6250 necessary storage before the SDRAM controller is setup. It's
6251 beyond the scope of this list to explain the details, but you
6252 can see how this works by studying the cache architecture and
6253 operation in the architecture and processor-specific manuals.
6255 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6256 is another option for the system designer to use as an
6257 initial stack/RAM area prior to SDRAM being available. Either
6258 option should work for you. Using CS 4 should be fine if your
6259 board designers haven't used it for something that would
6260 cause you grief during the initial boot! It is frequently not
6263 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6264 with your processor/board/system design. The default value
6265 you will find in any recent u-boot distribution in
6266 walnut.h should work for you. I'd set it to a value larger
6267 than your SDRAM module. If you have a 64MB SDRAM module, set
6268 it above 400_0000. Just make sure your board has no resources
6269 that are supposed to respond to that address! That code in
6270 start.S has been around a while and should work as is when
6271 you get the config right.
6276 It is essential to remember this, since it has some impact on the C
6277 code for the initialization procedures:
6279 * Initialized global data (data segment) is read-only. Do not attempt
6282 * Do not use any uninitialized global data (or implicitly initialized
6283 as zero data - BSS segment) at all - this is undefined, initiali-
6284 zation is performed later (when relocating to RAM).
6286 * Stack space is very limited. Avoid big data buffers or things like
6289 Having only the stack as writable memory limits means we cannot use
6290 normal global data to share information between the code. But it
6291 turned out that the implementation of U-Boot can be greatly
6292 simplified by making a global data structure (gd_t) available to all
6293 functions. We could pass a pointer to this data as argument to _all_
6294 functions, but this would bloat the code. Instead we use a feature of
6295 the GCC compiler (Global Register Variables) to share the data: we
6296 place a pointer (gd) to the global data into a register which we
6297 reserve for this purpose.
6299 When choosing a register for such a purpose we are restricted by the
6300 relevant (E)ABI specifications for the current architecture, and by
6301 GCC's implementation.
6303 For PowerPC, the following registers have specific use:
6305 R2: reserved for system use
6306 R3-R4: parameter passing and return values
6307 R5-R10: parameter passing
6308 R13: small data area pointer
6312 (U-Boot also uses R12 as internal GOT pointer. r12
6313 is a volatile register so r12 needs to be reset when
6314 going back and forth between asm and C)
6316 ==> U-Boot will use R2 to hold a pointer to the global data
6318 Note: on PPC, we could use a static initializer (since the
6319 address of the global data structure is known at compile time),
6320 but it turned out that reserving a register results in somewhat
6321 smaller code - although the code savings are not that big (on
6322 average for all boards 752 bytes for the whole U-Boot image,
6323 624 text + 127 data).
6325 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6326 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6328 ==> U-Boot will use P3 to hold a pointer to the global data
6330 On ARM, the following registers are used:
6332 R0: function argument word/integer result
6333 R1-R3: function argument word
6334 R9: platform specific
6335 R10: stack limit (used only if stack checking is enabled)
6336 R11: argument (frame) pointer
6337 R12: temporary workspace
6340 R15: program counter
6342 ==> U-Boot will use R9 to hold a pointer to the global data
6344 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6346 On Nios II, the ABI is documented here:
6347 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6349 ==> U-Boot will use gp to hold a pointer to the global data
6351 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6352 to access small data sections, so gp is free.
6354 On NDS32, the following registers are used:
6356 R0-R1: argument/return
6358 R15: temporary register for assembler
6359 R16: trampoline register
6360 R28: frame pointer (FP)
6361 R29: global pointer (GP)
6362 R30: link register (LP)
6363 R31: stack pointer (SP)
6364 PC: program counter (PC)
6366 ==> U-Boot will use R10 to hold a pointer to the global data
6368 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6369 or current versions of GCC may "optimize" the code too much.
6374 U-Boot runs in system state and uses physical addresses, i.e. the
6375 MMU is not used either for address mapping nor for memory protection.
6377 The available memory is mapped to fixed addresses using the memory
6378 controller. In this process, a contiguous block is formed for each
6379 memory type (Flash, SDRAM, SRAM), even when it consists of several
6380 physical memory banks.
6382 U-Boot is installed in the first 128 kB of the first Flash bank (on
6383 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6384 booting and sizing and initializing DRAM, the code relocates itself
6385 to the upper end of DRAM. Immediately below the U-Boot code some
6386 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6387 configuration setting]. Below that, a structure with global Board
6388 Info data is placed, followed by the stack (growing downward).
6390 Additionally, some exception handler code is copied to the low 8 kB
6391 of DRAM (0x00000000 ... 0x00001FFF).
6393 So a typical memory configuration with 16 MB of DRAM could look like
6396 0x0000 0000 Exception Vector code
6399 0x0000 2000 Free for Application Use
6405 0x00FB FF20 Monitor Stack (Growing downward)
6406 0x00FB FFAC Board Info Data and permanent copy of global data
6407 0x00FC 0000 Malloc Arena
6410 0x00FE 0000 RAM Copy of Monitor Code
6411 ... eventually: LCD or video framebuffer
6412 ... eventually: pRAM (Protected RAM - unchanged by reset)
6413 0x00FF FFFF [End of RAM]
6416 System Initialization:
6417 ----------------------
6419 In the reset configuration, U-Boot starts at the reset entry point
6420 (on most PowerPC systems at address 0x00000100). Because of the reset
6421 configuration for CS0# this is a mirror of the on board Flash memory.
6422 To be able to re-map memory U-Boot then jumps to its link address.
6423 To be able to implement the initialization code in C, a (small!)
6424 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6425 which provide such a feature like MPC8xx or MPC8260), or in a locked
6426 part of the data cache. After that, U-Boot initializes the CPU core,
6427 the caches and the SIU.
6429 Next, all (potentially) available memory banks are mapped using a
6430 preliminary mapping. For example, we put them on 512 MB boundaries
6431 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6432 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6433 programmed for SDRAM access. Using the temporary configuration, a
6434 simple memory test is run that determines the size of the SDRAM
6437 When there is more than one SDRAM bank, and the banks are of
6438 different size, the largest is mapped first. For equal size, the first
6439 bank (CS2#) is mapped first. The first mapping is always for address
6440 0x00000000, with any additional banks following immediately to create
6441 contiguous memory starting from 0.
6443 Then, the monitor installs itself at the upper end of the SDRAM area
6444 and allocates memory for use by malloc() and for the global Board
6445 Info data; also, the exception vector code is copied to the low RAM
6446 pages, and the final stack is set up.
6448 Only after this relocation will you have a "normal" C environment;
6449 until that you are restricted in several ways, mostly because you are
6450 running from ROM, and because the code will have to be relocated to a
6454 U-Boot Porting Guide:
6455 ----------------------
6457 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6461 int main(int argc, char *argv[])
6463 sighandler_t no_more_time;
6465 signal(SIGALRM, no_more_time);
6466 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6468 if (available_money > available_manpower) {
6469 Pay consultant to port U-Boot;
6473 Download latest U-Boot source;
6475 Subscribe to u-boot mailing list;
6478 email("Hi, I am new to U-Boot, how do I get started?");
6481 Read the README file in the top level directory;
6482 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6483 Read applicable doc/*.README;
6484 Read the source, Luke;
6485 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6488 if (available_money > toLocalCurrency ($2500))
6491 Add a lot of aggravation and time;
6493 if (a similar board exists) { /* hopefully... */
6494 cp -a board/<similar> board/<myboard>
6495 cp include/configs/<similar>.h include/configs/<myboard>.h
6497 Create your own board support subdirectory;
6498 Create your own board include/configs/<myboard>.h file;
6500 Edit new board/<myboard> files
6501 Edit new include/configs/<myboard>.h
6506 Add / modify source code;
6510 email("Hi, I am having problems...");
6512 Send patch file to the U-Boot email list;
6513 if (reasonable critiques)
6514 Incorporate improvements from email list code review;
6516 Defend code as written;
6522 void no_more_time (int sig)
6531 All contributions to U-Boot should conform to the Linux kernel
6532 coding style; see the file "Documentation/CodingStyle" and the script
6533 "scripts/Lindent" in your Linux kernel source directory.
6535 Source files originating from a different project (for example the
6536 MTD subsystem) are generally exempt from these guidelines and are not
6537 reformatted to ease subsequent migration to newer versions of those
6540 Please note that U-Boot is implemented in C (and to some small parts in
6541 Assembler); no C++ is used, so please do not use C++ style comments (//)
6544 Please also stick to the following formatting rules:
6545 - remove any trailing white space
6546 - use TAB characters for indentation and vertical alignment, not spaces
6547 - make sure NOT to use DOS '\r\n' line feeds
6548 - do not add more than 2 consecutive empty lines to source files
6549 - do not add trailing empty lines to source files
6551 Submissions which do not conform to the standards may be returned
6552 with a request to reformat the changes.
6558 Since the number of patches for U-Boot is growing, we need to
6559 establish some rules. Submissions which do not conform to these rules
6560 may be rejected, even when they contain important and valuable stuff.
6562 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6564 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6565 see http://lists.denx.de/mailman/listinfo/u-boot
6567 When you send a patch, please include the following information with
6570 * For bug fixes: a description of the bug and how your patch fixes
6571 this bug. Please try to include a way of demonstrating that the
6572 patch actually fixes something.
6574 * For new features: a description of the feature and your
6577 * A CHANGELOG entry as plaintext (separate from the patch)
6579 * For major contributions, add a MAINTAINERS file with your
6580 information and associated file and directory references.
6582 * When you add support for a new board, don't forget to add a
6583 maintainer e-mail address to the boards.cfg file, too.
6585 * If your patch adds new configuration options, don't forget to
6586 document these in the README file.
6588 * The patch itself. If you are using git (which is *strongly*
6589 recommended) you can easily generate the patch using the
6590 "git format-patch". If you then use "git send-email" to send it to
6591 the U-Boot mailing list, you will avoid most of the common problems
6592 with some other mail clients.
6594 If you cannot use git, use "diff -purN OLD NEW". If your version of
6595 diff does not support these options, then get the latest version of
6598 The current directory when running this command shall be the parent
6599 directory of the U-Boot source tree (i. e. please make sure that
6600 your patch includes sufficient directory information for the
6603 We prefer patches as plain text. MIME attachments are discouraged,
6604 and compressed attachments must not be used.
6606 * If one logical set of modifications affects or creates several
6607 files, all these changes shall be submitted in a SINGLE patch file.
6609 * Changesets that contain different, unrelated modifications shall be
6610 submitted as SEPARATE patches, one patch per changeset.
6615 * Before sending the patch, run the MAKEALL script on your patched
6616 source tree and make sure that no errors or warnings are reported
6617 for any of the boards.
6619 * Keep your modifications to the necessary minimum: A patch
6620 containing several unrelated changes or arbitrary reformats will be
6621 returned with a request to re-formatting / split it.
6623 * If you modify existing code, make sure that your new code does not
6624 add to the memory footprint of the code ;-) Small is beautiful!
6625 When adding new features, these should compile conditionally only
6626 (using #ifdef), and the resulting code with the new feature
6627 disabled must not need more memory than the old code without your
6630 * Remember that there is a size limit of 100 kB per message on the
6631 u-boot mailing list. Bigger patches will be moderated. If they are
6632 reasonable and not too big, they will be acknowledged. But patches
6633 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob