2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
52 In case you have questions about, problems with or contributions for
53 U-Boot, you should send a message to the U-Boot mailing list at
54 <u-boot@lists.denx.de>. There is also an archive of previous traffic
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
60 Where to get source code:
61 =========================
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
82 - make it easier to add custom boards
83 - make it possible to add other [PowerPC] CPUs
84 - extend functions, especially:
85 * Provide extended interface to Linux boot loader
88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
89 - create ARMBoot project (http://sourceforge.net/projects/armboot)
90 - add other CPU families (starting with ARM)
91 - create U-Boot project (http://sourceforge.net/projects/u-boot)
92 - current project page: see http://www.denx.de/wiki/U-Boot
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
102 This is the README file for the U-Boot project.
104 File names etc. shall be based on the string "u-boot". Examples:
106 include/asm-ppc/u-boot.h
108 #include <asm/u-boot.h>
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
128 U-Boot v2009.11 - Release November 2009
129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
130 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /blackfin Files generic to Analog Devices Blackfin architecture
141 /m68k Files generic to m68k architecture
142 /microblaze Files generic to microblaze architecture
143 /mips Files generic to MIPS architecture
144 /nds32 Files generic to NDS32 architecture
145 /nios2 Files generic to Altera NIOS2 architecture
146 /openrisc Files generic to OpenRISC architecture
147 /powerpc Files generic to PowerPC architecture
148 /sandbox Files generic to HW-independent "sandbox"
149 /sh Files generic to SH architecture
150 /sparc Files generic to SPARC architecture
151 /x86 Files generic to x86 architecture
152 /api Machine/arch independent API for external apps
153 /board Board dependent files
154 /common Misc architecture independent functions
155 /configs Board default configuration files
156 /disk Code for disk drive partition handling
157 /doc Documentation (don't expect too much)
158 /drivers Commonly used device drivers
159 /dts Contains Makefile for building internal U-Boot fdt.
160 /examples Example code for standalone applications, etc.
161 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
162 /include Header Files
163 /lib Library routines generic to all architectures
164 /Licenses Various license files
166 /post Power On Self Test
167 /scripts Various build scripts and Makefiles
168 /test Various unit test files
169 /tools Tools to build S-Record or U-Boot images, etc.
171 Software Configuration:
172 =======================
174 Configuration is usually done using C preprocessor defines; the
175 rationale behind that is to avoid dead code whenever possible.
177 There are two classes of configuration variables:
179 * Configuration _OPTIONS_:
180 These are selectable by the user and have names beginning with
183 * Configuration _SETTINGS_:
184 These depend on the hardware etc. and should not be meddled with if
185 you don't know what you're doing; they have names beginning with
188 Previously, all configuration was done by hand, which involved creating
189 symbolic links and editing configuration files manually. More recently,
190 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
191 allowing you to use the "make menuconfig" command to configure your
195 Selection of Processor Architecture and Board Type:
196 ---------------------------------------------------
198 For all supported boards there are ready-to-use default
199 configurations available; just type "make <board_name>_defconfig".
201 Example: For a TQM823L module type:
204 make TQM823L_defconfig
206 Note: If you're looking for the default configuration file for a board
207 you're sure used to be there but is now missing, check the file
208 doc/README.scrapyard for a list of no longer supported boards.
213 U-Boot can be built natively to run on a Linux host using the 'sandbox'
214 board. This allows feature development which is not board- or architecture-
215 specific to be undertaken on a native platform. The sandbox is also used to
216 run some of U-Boot's tests.
218 See board/sandbox/README.sandbox for more details.
221 Board Initialisation Flow:
222 --------------------------
224 This is the intended start-up flow for boards. This should apply for both
225 SPL and U-Boot proper (i.e. they both follow the same rules).
227 Note: "SPL" stands for "Secondary Program Loader," which is explained in
228 more detail later in this file.
230 At present, SPL mostly uses a separate code path, but the function names
231 and roles of each function are the same. Some boards or architectures
232 may not conform to this. At least most ARM boards which use
233 CONFIG_SPL_FRAMEWORK conform to this.
235 Execution typically starts with an architecture-specific (and possibly
236 CPU-specific) start.S file, such as:
238 - arch/arm/cpu/armv7/start.S
239 - arch/powerpc/cpu/mpc83xx/start.S
240 - arch/mips/cpu/start.S
242 and so on. From there, three functions are called; the purpose and
243 limitations of each of these functions are described below.
246 - purpose: essential init to permit execution to reach board_init_f()
247 - no global_data or BSS
248 - there is no stack (ARMv7 may have one but it will soon be removed)
249 - must not set up SDRAM or use console
250 - must only do the bare minimum to allow execution to continue to
252 - this is almost never needed
253 - return normally from this function
256 - purpose: set up the machine ready for running board_init_r():
257 i.e. SDRAM and serial UART
258 - global_data is available
260 - BSS is not available, so you cannot use global/static variables,
261 only stack variables and global_data
263 Non-SPL-specific notes:
264 - dram_init() is called to set up DRAM. If already done in SPL this
268 - you can override the entire board_init_f() function with your own
270 - preloader_console_init() can be called here in extremis
271 - should set up SDRAM, and anything needed to make the UART work
272 - these is no need to clear BSS, it will be done by crt0.S
273 - must return normally from this function (don't call board_init_r()
276 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
277 this point the stack and global_data are relocated to below
278 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
282 - purpose: main execution, common code
283 - global_data is available
285 - BSS is available, all static/global variables can be used
286 - execution eventually continues to main_loop()
288 Non-SPL-specific notes:
289 - U-Boot is relocated to the top of memory and is now running from
293 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
294 CONFIG_SPL_STACK_R_ADDR points into SDRAM
295 - preloader_console_init() can be called here - typically this is
296 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
297 spl_board_init() function containing this call
298 - loads U-Boot or (in falcon mode) Linux
302 Configuration Options:
303 ----------------------
305 Configuration depends on the combination of board and CPU type; all
306 such information is kept in a configuration file
307 "include/configs/<board_name>.h".
309 Example: For a TQM823L module, all configuration settings are in
310 "include/configs/TQM823L.h".
313 Many of the options are named exactly as the corresponding Linux
314 kernel configuration options. The intention is to make it easier to
315 build a config tool - later.
318 The following options need to be configured:
320 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
322 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
324 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
325 Define exactly one, e.g. CONFIG_ATSTK1002
327 - CPU Module Type: (if CONFIG_COGENT is defined)
328 Define exactly one of
330 --- FIXME --- not tested yet:
331 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
332 CONFIG_CMA287_23, CONFIG_CMA287_50
334 - Motherboard Type: (if CONFIG_COGENT is defined)
335 Define exactly one of
336 CONFIG_CMA101, CONFIG_CMA102
338 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
339 Define one or more of
342 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
343 Define one or more of
344 CONFIG_LCD_HEARTBEAT - update a character position on
345 the LCD display every second with
348 - Marvell Family Member
349 CONFIG_SYS_MVFS - define it if you want to enable
350 multiple fs option at one time
351 for marvell soc family
353 - 8xx CPU Options: (if using an MPC8xx CPU)
354 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
355 get_gclk_freq() cannot work
356 e.g. if there is no 32KHz
357 reference PIT/RTC clock
358 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
361 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
362 CONFIG_SYS_8xx_CPUCLK_MIN
363 CONFIG_SYS_8xx_CPUCLK_MAX
364 CONFIG_8xx_CPUCLK_DEFAULT
365 See doc/README.MPC866
367 CONFIG_SYS_MEASURE_CPUCLK
369 Define this to measure the actual CPU clock instead
370 of relying on the correctness of the configured
371 values. Mostly useful for board bringup to make sure
372 the PLL is locked at the intended frequency. Note
373 that this requires a (stable) reference clock (32 kHz
374 RTC clock or CONFIG_SYS_8XX_XIN)
376 CONFIG_SYS_DELAYED_ICACHE
378 Define this option if you want to enable the
379 ICache only when Code runs from RAM.
384 Specifies that the core is a 64-bit PowerPC implementation (implements
385 the "64" category of the Power ISA). This is necessary for ePAPR
386 compliance, among other possible reasons.
388 CONFIG_SYS_FSL_TBCLK_DIV
390 Defines the core time base clock divider ratio compared to the
391 system clock. On most PQ3 devices this is 8, on newer QorIQ
392 devices it can be 16 or 32. The ratio varies from SoC to Soc.
394 CONFIG_SYS_FSL_PCIE_COMPAT
396 Defines the string to utilize when trying to match PCIe device
397 tree nodes for the given platform.
399 CONFIG_SYS_PPC_E500_DEBUG_TLB
401 Enables a temporary TLB entry to be used during boot to work
402 around limitations in e500v1 and e500v2 external debugger
403 support. This reduces the portions of the boot code where
404 breakpoints and single stepping do not work. The value of this
405 symbol should be set to the TLB1 entry to be used for this
408 CONFIG_SYS_FSL_ERRATUM_A004510
410 Enables a workaround for erratum A004510. If set,
411 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
414 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
415 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
417 Defines one or two SoC revisions (low 8 bits of SVR)
418 for which the A004510 workaround should be applied.
420 The rest of SVR is either not relevant to the decision
421 of whether the erratum is present (e.g. p2040 versus
422 p2041) or is implied by the build target, which controls
423 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
425 See Freescale App Note 4493 for more information about
428 CONFIG_A003399_NOR_WORKAROUND
429 Enables a workaround for IFC erratum A003399. It is only
430 required during NOR boot.
432 CONFIG_A008044_WORKAROUND
433 Enables a workaround for T1040/T1042 erratum A008044. It is only
434 required during NAND boot and valid for Rev 1.0 SoC revision
436 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
438 This is the value to write into CCSR offset 0x18600
439 according to the A004510 workaround.
441 CONFIG_SYS_FSL_DSP_DDR_ADDR
442 This value denotes start offset of DDR memory which is
443 connected exclusively to the DSP cores.
445 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
446 This value denotes start offset of M2 memory
447 which is directly connected to the DSP core.
449 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
450 This value denotes start offset of M3 memory which is directly
451 connected to the DSP core.
453 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
454 This value denotes start offset of DSP CCSR space.
456 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
457 Single Source Clock is clocking mode present in some of FSL SoC's.
458 In this mode, a single differential clock is used to supply
459 clocks to the sysclock, ddrclock and usbclock.
461 CONFIG_SYS_CPC_REINIT_F
462 This CONFIG is defined when the CPC is configured as SRAM at the
463 time of U-Boot entry and is required to be re-initialized.
466 Indicates this SoC supports deep sleep feature. If deep sleep is
467 supported, core will start to execute uboot when wakes up.
469 - Generic CPU options:
470 CONFIG_SYS_GENERIC_GLOBAL_DATA
471 Defines global data is initialized in generic board board_init_f().
472 If this macro is defined, global data is created and cleared in
473 generic board board_init_f(). Without this macro, architecture/board
474 should initialize global data before calling board_init_f().
476 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
478 Defines the endianess of the CPU. Implementation of those
479 values is arch specific.
482 Freescale DDR driver in use. This type of DDR controller is
483 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
486 CONFIG_SYS_FSL_DDR_ADDR
487 Freescale DDR memory-mapped register base.
489 CONFIG_SYS_FSL_DDR_EMU
490 Specify emulator support for DDR. Some DDR features such as
491 deskew training are not available.
493 CONFIG_SYS_FSL_DDRC_GEN1
494 Freescale DDR1 controller.
496 CONFIG_SYS_FSL_DDRC_GEN2
497 Freescale DDR2 controller.
499 CONFIG_SYS_FSL_DDRC_GEN3
500 Freescale DDR3 controller.
502 CONFIG_SYS_FSL_DDRC_GEN4
503 Freescale DDR4 controller.
505 CONFIG_SYS_FSL_DDRC_ARM_GEN3
506 Freescale DDR3 controller for ARM-based SoCs.
509 Board config to use DDR1. It can be enabled for SoCs with
510 Freescale DDR1 or DDR2 controllers, depending on the board
514 Board config to use DDR2. It can be eanbeld for SoCs with
515 Freescale DDR2 or DDR3 controllers, depending on the board
519 Board config to use DDR3. It can be enabled for SoCs with
520 Freescale DDR3 or DDR3L controllers.
523 Board config to use DDR3L. It can be enabled for SoCs with
527 Board config to use DDR4. It can be enabled for SoCs with
530 CONFIG_SYS_FSL_IFC_BE
531 Defines the IFC controller register space as Big Endian
533 CONFIG_SYS_FSL_IFC_LE
534 Defines the IFC controller register space as Little Endian
536 CONFIG_SYS_FSL_PBL_PBI
537 It enables addition of RCW (Power on reset configuration) in built image.
538 Please refer doc/README.pblimage for more details
540 CONFIG_SYS_FSL_PBL_RCW
541 It adds PBI(pre-boot instructions) commands in u-boot build image.
542 PBI commands can be used to configure SoC before it starts the execution.
543 Please refer doc/README.pblimage for more details
546 It adds a target to create boot binary having SPL binary in PBI format
547 concatenated with u-boot binary.
549 CONFIG_SYS_FSL_DDR_BE
550 Defines the DDR controller register space as Big Endian
552 CONFIG_SYS_FSL_DDR_LE
553 Defines the DDR controller register space as Little Endian
555 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
556 Physical address from the view of DDR controllers. It is the
557 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
558 it could be different for ARM SoCs.
560 CONFIG_SYS_FSL_DDR_INTLV_256B
561 DDR controller interleaving on 256-byte. This is a special
562 interleaving mode, handled by Dickens for Freescale layerscape
565 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
566 Number of controllers used as main memory.
568 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
569 Number of controllers used for other than main memory.
571 CONFIG_SYS_FSL_HAS_DP_DDR
572 Defines the SoC has DP-DDR used for DPAA.
574 CONFIG_SYS_FSL_SEC_BE
575 Defines the SEC controller register space as Big Endian
577 CONFIG_SYS_FSL_SEC_LE
578 Defines the SEC controller register space as Little Endian
580 - Intel Monahans options:
581 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
583 Defines the Monahans run mode to oscillator
584 ratio. Valid values are 8, 16, 24, 31. The core
585 frequency is this value multiplied by 13 MHz.
587 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
589 Defines the Monahans turbo mode to oscillator
590 ratio. Valid values are 1 (default if undefined) and
591 2. The core frequency as calculated above is multiplied
595 CONFIG_SYS_INIT_SP_OFFSET
597 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
598 pointer. This is needed for the temporary stack before
601 CONFIG_SYS_MIPS_CACHE_MODE
603 Cache operation mode for the MIPS CPU.
604 See also arch/mips/include/asm/mipsregs.h.
606 CONF_CM_CACHABLE_NO_WA
609 CONF_CM_CACHABLE_NONCOHERENT
613 CONF_CM_CACHABLE_ACCELERATED
615 CONFIG_SYS_XWAY_EBU_BOOTCFG
617 Special option for Lantiq XWAY SoCs for booting from NOR flash.
618 See also arch/mips/cpu/mips32/start.S.
620 CONFIG_XWAY_SWAP_BYTES
622 Enable compilation of tools/xway-swap-bytes needed for Lantiq
623 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
624 be swapped if a flash programmer is used.
627 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
629 Select high exception vectors of the ARM core, e.g., do not
630 clear the V bit of the c1 register of CP15.
632 CONFIG_SYS_THUMB_BUILD
634 Use this flag to build U-Boot using the Thumb instruction
635 set for ARM architectures. Thumb instruction set provides
636 better code density. For ARM architectures that support
637 Thumb2 this flag will result in Thumb2 code generated by
640 CONFIG_ARM_ERRATA_716044
641 CONFIG_ARM_ERRATA_742230
642 CONFIG_ARM_ERRATA_743622
643 CONFIG_ARM_ERRATA_751472
644 CONFIG_ARM_ERRATA_761320
645 CONFIG_ARM_ERRATA_773022
646 CONFIG_ARM_ERRATA_774769
647 CONFIG_ARM_ERRATA_794072
649 If set, the workarounds for these ARM errata are applied early
650 during U-Boot startup. Note that these options force the
651 workarounds to be applied; no CPU-type/version detection
652 exists, unlike the similar options in the Linux kernel. Do not
653 set these options unless they apply!
656 Generic timer clock source frequency.
658 COUNTER_FREQUENCY_REAL
659 Generic timer clock source frequency if the real clock is
660 different from COUNTER_FREQUENCY, and can only be determined
663 NOTE: The following can be machine specific errata. These
664 do have ability to provide rudimentary version and machine
665 specific checks, but expect no product checks.
666 CONFIG_ARM_ERRATA_430973
667 CONFIG_ARM_ERRATA_454179
668 CONFIG_ARM_ERRATA_621766
669 CONFIG_ARM_ERRATA_798870
670 CONFIG_ARM_ERRATA_801819
673 CONFIG_TEGRA_SUPPORT_NON_SECURE
675 Support executing U-Boot in non-secure (NS) mode. Certain
676 impossible actions will be skipped if the CPU is in NS mode,
677 such as ARM architectural timer initialization.
679 - Linux Kernel Interface:
682 U-Boot stores all clock information in Hz
683 internally. For binary compatibility with older Linux
684 kernels (which expect the clocks passed in the
685 bd_info data to be in MHz) the environment variable
686 "clocks_in_mhz" can be defined so that U-Boot
687 converts clock data to MHZ before passing it to the
689 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
690 "clocks_in_mhz=1" is automatically included in the
693 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
695 When transferring memsize parameter to Linux, some versions
696 expect it to be in bytes, others in MB.
697 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
701 New kernel versions are expecting firmware settings to be
702 passed using flattened device trees (based on open firmware
706 * New libfdt-based support
707 * Adds the "fdt" command
708 * The bootm command automatically updates the fdt
710 OF_CPU - The proper name of the cpus node (only required for
711 MPC512X and MPC5xxx based boards).
712 OF_SOC - The proper name of the soc node (only required for
713 MPC512X and MPC5xxx based boards).
714 OF_TBCLK - The timebase frequency.
715 OF_STDOUT_PATH - The path to the console device
717 boards with QUICC Engines require OF_QE to set UCC MAC
720 CONFIG_OF_BOARD_SETUP
722 Board code has addition modification that it wants to make
723 to the flat device tree before handing it off to the kernel
725 CONFIG_OF_SYSTEM_SETUP
727 Other code has addition modification that it wants to make
728 to the flat device tree before handing it off to the kernel.
729 This causes ft_system_setup() to be called before booting
734 This define fills in the correct boot CPU in the boot
735 param header, the default value is zero if undefined.
739 U-Boot can detect if an IDE device is present or not.
740 If not, and this new config option is activated, U-Boot
741 removes the ATA node from the DTS before booting Linux,
742 so the Linux IDE driver does not probe the device and
743 crash. This is needed for buggy hardware (uc101) where
744 no pull down resistor is connected to the signal IDE5V_DD7.
746 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
748 This setting is mandatory for all boards that have only one
749 machine type and must be used to specify the machine type
750 number as it appears in the ARM machine registry
751 (see http://www.arm.linux.org.uk/developer/machines/).
752 Only boards that have multiple machine types supported
753 in a single configuration file and the machine type is
754 runtime discoverable, do not have to use this setting.
756 - vxWorks boot parameters:
758 bootvx constructs a valid bootline using the following
759 environments variables: bootdev, bootfile, ipaddr, netmask,
760 serverip, gatewayip, hostname, othbootargs.
761 It loads the vxWorks image pointed bootfile.
763 Note: If a "bootargs" environment is defined, it will overwride
764 the defaults discussed just above.
766 - Cache Configuration:
767 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
768 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
769 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
771 - Cache Configuration for ARM:
772 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
774 CONFIG_SYS_PL310_BASE - Physical base address of PL310
775 controller register space
780 Define this if you want support for Amba PrimeCell PL010 UARTs.
784 Define this if you want support for Amba PrimeCell PL011 UARTs.
788 If you have Amba PrimeCell PL011 UARTs, set this variable to
789 the clock speed of the UARTs.
793 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
794 define this to a list of base addresses for each (supported)
795 port. See e.g. include/configs/versatile.h
797 CONFIG_SERIAL_HW_FLOW_CONTROL
799 Define this variable to enable hw flow control in serial driver.
800 Current user of this option is drivers/serial/nsl16550.c driver
803 Depending on board, define exactly one serial port
804 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
805 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
806 console by defining CONFIG_8xx_CONS_NONE
808 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
809 port routines must be defined elsewhere
810 (i.e. serial_init(), serial_getc(), ...)
813 Enables console device for a color framebuffer. Needs following
814 defines (cf. smiLynxEM, i8042)
815 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
817 VIDEO_HW_RECTFILL graphic chip supports
820 VIDEO_HW_BITBLT graphic chip supports
821 bit-blit (cf. smiLynxEM)
822 VIDEO_VISIBLE_COLS visible pixel columns
824 VIDEO_VISIBLE_ROWS visible pixel rows
825 VIDEO_PIXEL_SIZE bytes per pixel
826 VIDEO_DATA_FORMAT graphic data format
827 (0-5, cf. cfb_console.c)
828 VIDEO_FB_ADRS framebuffer address
829 VIDEO_KBD_INIT_FCT keyboard int fct
830 (i.e. rx51_kp_init())
831 VIDEO_TSTC_FCT test char fct
833 VIDEO_GETC_FCT get char fct
835 CONFIG_VIDEO_LOGO display Linux logo in
837 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
838 linux_logo.h for logo.
839 Requires CONFIG_VIDEO_LOGO
840 CONFIG_CONSOLE_EXTRA_INFO
841 additional board info beside
844 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
845 a limited number of ANSI escape sequences (cursor control,
846 erase functions and limited graphics rendition control).
848 When CONFIG_CFB_CONSOLE is defined, video console is
849 default i/o. Serial console can be forced with
850 environment 'console=serial'.
852 When CONFIG_SILENT_CONSOLE is defined, all console
853 messages (by U-Boot and Linux!) can be silenced with
854 the "silent" environment variable. See
855 doc/README.silent for more information.
857 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
859 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
863 CONFIG_BAUDRATE - in bps
864 Select one of the baudrates listed in
865 CONFIG_SYS_BAUDRATE_TABLE, see below.
866 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
868 - Console Rx buffer length
869 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
870 the maximum receive buffer length for the SMC.
871 This option is actual only for 82xx and 8xx possible.
872 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
873 must be defined, to setup the maximum idle timeout for
876 - Pre-Console Buffer:
877 Prior to the console being initialised (i.e. serial UART
878 initialised etc) all console output is silently discarded.
879 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
880 buffer any console messages prior to the console being
881 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
882 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
883 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
884 bytes are output before the console is initialised, the
885 earlier bytes are discarded.
887 Note that when printing the buffer a copy is made on the
888 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
890 'Sane' compilers will generate smaller code if
891 CONFIG_PRE_CON_BUF_SZ is a power of 2
893 - Boot Delay: CONFIG_BOOTDELAY - in seconds
894 Delay before automatically booting the default image;
895 set to -1 to disable autoboot.
896 set to -2 to autoboot with no delay and not check for abort
897 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
899 See doc/README.autoboot for these options that
900 work with CONFIG_BOOTDELAY. None are required.
901 CONFIG_BOOT_RETRY_TIME
902 CONFIG_BOOT_RETRY_MIN
903 CONFIG_AUTOBOOT_KEYED
904 CONFIG_AUTOBOOT_PROMPT
905 CONFIG_AUTOBOOT_DELAY_STR
906 CONFIG_AUTOBOOT_STOP_STR
907 CONFIG_ZERO_BOOTDELAY_CHECK
908 CONFIG_RESET_TO_RETRY
912 Only needed when CONFIG_BOOTDELAY is enabled;
913 define a command string that is automatically executed
914 when no character is read on the console interface
915 within "Boot Delay" after reset.
918 This can be used to pass arguments to the bootm
919 command. The value of CONFIG_BOOTARGS goes into the
920 environment value "bootargs".
922 CONFIG_RAMBOOT and CONFIG_NFSBOOT
923 The value of these goes into the environment as
924 "ramboot" and "nfsboot" respectively, and can be used
925 as a convenience, when switching between booting from
929 CONFIG_BOOTCOUNT_LIMIT
930 Implements a mechanism for detecting a repeating reboot
932 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
935 If no softreset save registers are found on the hardware
936 "bootcount" is stored in the environment. To prevent a
937 saveenv on all reboots, the environment variable
938 "upgrade_available" is used. If "upgrade_available" is
939 0, "bootcount" is always 0, if "upgrade_available" is
940 1 "bootcount" is incremented in the environment.
941 So the Userspace Applikation must set the "upgrade_available"
942 and "bootcount" variable to 0, if a boot was successfully.
947 When this option is #defined, the existence of the
948 environment variable "preboot" will be checked
949 immediately before starting the CONFIG_BOOTDELAY
950 countdown and/or running the auto-boot command resp.
951 entering interactive mode.
953 This feature is especially useful when "preboot" is
954 automatically generated or modified. For an example
955 see the LWMON board specific code: here "preboot" is
956 modified when the user holds down a certain
957 combination of keys on the (special) keyboard when
960 - Serial Download Echo Mode:
962 If defined to 1, all characters received during a
963 serial download (using the "loads" command) are
964 echoed back. This might be needed by some terminal
965 emulations (like "cu"), but may as well just take
966 time on others. This setting #define's the initial
967 value of the "loads_echo" environment variable.
969 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
971 Select one of the baudrates listed in
972 CONFIG_SYS_BAUDRATE_TABLE, see below.
975 Monitor commands can be included or excluded
976 from the build by using the #include files
977 <config_cmd_all.h> and #undef'ing unwanted
978 commands, or adding #define's for wanted commands.
980 The default command configuration includes all commands
981 except those marked below with a "*".
983 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
984 CONFIG_CMD_ASKENV * ask for env variable
985 CONFIG_CMD_BDI bdinfo
986 CONFIG_CMD_BEDBUG * Include BedBug Debugger
987 CONFIG_CMD_BMP * BMP support
988 CONFIG_CMD_BSP * Board specific commands
989 CONFIG_CMD_BOOTD bootd
990 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
991 CONFIG_CMD_CACHE * icache, dcache
992 CONFIG_CMD_CLK * clock command support
993 CONFIG_CMD_CONSOLE coninfo
994 CONFIG_CMD_CRC32 * crc32
995 CONFIG_CMD_DATE * support for RTC, date/time...
996 CONFIG_CMD_DHCP * DHCP support
997 CONFIG_CMD_DIAG * Diagnostics
998 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
999 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
1000 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
1001 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
1002 CONFIG_CMD_DTT * Digital Therm and Thermostat
1003 CONFIG_CMD_ECHO echo arguments
1004 CONFIG_CMD_EDITENV edit env variable
1005 CONFIG_CMD_EEPROM * EEPROM read/write support
1006 CONFIG_CMD_ELF * bootelf, bootvx
1007 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
1008 CONFIG_CMD_ENV_FLAGS * display details about env flags
1009 CONFIG_CMD_ENV_EXISTS * check existence of env variable
1010 CONFIG_CMD_EXPORTENV * export the environment
1011 CONFIG_CMD_EXT2 * ext2 command support
1012 CONFIG_CMD_EXT4 * ext4 command support
1013 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
1014 that work for multiple fs types
1015 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
1016 CONFIG_CMD_SAVEENV saveenv
1017 CONFIG_CMD_FDC * Floppy Disk Support
1018 CONFIG_CMD_FAT * FAT command support
1019 CONFIG_CMD_FLASH flinfo, erase, protect
1020 CONFIG_CMD_FPGA FPGA device initialization support
1021 CONFIG_CMD_FUSE * Device fuse support
1022 CONFIG_CMD_GETTIME * Get time since boot
1023 CONFIG_CMD_GO * the 'go' command (exec code)
1024 CONFIG_CMD_GREPENV * search environment
1025 CONFIG_CMD_HASH * calculate hash / digest
1026 CONFIG_CMD_I2C * I2C serial bus support
1027 CONFIG_CMD_IDE * IDE harddisk support
1028 CONFIG_CMD_IMI iminfo
1029 CONFIG_CMD_IMLS List all images found in NOR flash
1030 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1031 CONFIG_CMD_IMMAP * IMMR dump support
1032 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1033 CONFIG_CMD_IMPORTENV * import an environment
1034 CONFIG_CMD_INI * import data from an ini file into the env
1035 CONFIG_CMD_IRQ * irqinfo
1036 CONFIG_CMD_ITEST Integer/string test of 2 values
1037 CONFIG_CMD_JFFS2 * JFFS2 Support
1038 CONFIG_CMD_KGDB * kgdb
1039 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1040 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1042 CONFIG_CMD_LOADB loadb
1043 CONFIG_CMD_LOADS loads
1044 CONFIG_CMD_MD5SUM * print md5 message digest
1045 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1046 CONFIG_CMD_MEMINFO * Display detailed memory information
1047 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1049 CONFIG_CMD_MEMTEST * mtest
1050 CONFIG_CMD_MISC Misc functions like sleep etc
1051 CONFIG_CMD_MMC * MMC memory mapped support
1052 CONFIG_CMD_MII * MII utility commands
1053 CONFIG_CMD_MTDPARTS * MTD partition support
1054 CONFIG_CMD_NAND * NAND support
1055 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1056 CONFIG_CMD_NFS NFS support
1057 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1058 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1059 CONFIG_CMD_PCI * pciinfo
1060 CONFIG_CMD_PCMCIA * PCMCIA support
1061 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1063 CONFIG_CMD_PORTIO * Port I/O
1064 CONFIG_CMD_READ * Read raw data from partition
1065 CONFIG_CMD_REGINFO * Register dump
1066 CONFIG_CMD_RUN run command in env variable
1067 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1068 CONFIG_CMD_SAVES * save S record dump
1069 CONFIG_CMD_SCSI * SCSI Support
1070 CONFIG_CMD_SDRAM * print SDRAM configuration information
1071 (requires CONFIG_CMD_I2C)
1072 CONFIG_CMD_SETGETDCR Support for DCR Register access
1074 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1075 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1076 (requires CONFIG_CMD_MEMORY)
1077 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1078 CONFIG_CMD_SOURCE "source" command Support
1079 CONFIG_CMD_SPI * SPI serial bus support
1080 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1081 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1082 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1083 CONFIG_CMD_TIMER * access to the system tick timer
1084 CONFIG_CMD_USB * USB support
1085 CONFIG_CMD_CDP * Cisco Discover Protocol support
1086 CONFIG_CMD_MFSL * Microblaze FSL support
1087 CONFIG_CMD_XIMG Load part of Multi Image
1088 CONFIG_CMD_UUID * Generate random UUID or GUID string
1090 EXAMPLE: If you want all functions except of network
1091 support you can write:
1093 #include "config_cmd_all.h"
1094 #undef CONFIG_CMD_NET
1097 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1099 Note: Don't enable the "icache" and "dcache" commands
1100 (configuration option CONFIG_CMD_CACHE) unless you know
1101 what you (and your U-Boot users) are doing. Data
1102 cache cannot be enabled on systems like the 8xx or
1103 8260 (where accesses to the IMMR region must be
1104 uncached), and it cannot be disabled on all other
1105 systems where we (mis-) use the data cache to hold an
1106 initial stack and some data.
1109 XXX - this list needs to get updated!
1111 - Regular expression support:
1113 If this variable is defined, U-Boot is linked against
1114 the SLRE (Super Light Regular Expression) library,
1115 which adds regex support to some commands, as for
1116 example "env grep" and "setexpr".
1120 If this variable is defined, U-Boot will use a device tree
1121 to configure its devices, instead of relying on statically
1122 compiled #defines in the board file. This option is
1123 experimental and only available on a few boards. The device
1124 tree is available in the global data as gd->fdt_blob.
1126 U-Boot needs to get its device tree from somewhere. This can
1127 be done using one of the two options below:
1130 If this variable is defined, U-Boot will embed a device tree
1131 binary in its image. This device tree file should be in the
1132 board directory and called <soc>-<board>.dts. The binary file
1133 is then picked up in board_init_f() and made available through
1134 the global data structure as gd->blob.
1137 If this variable is defined, U-Boot will build a device tree
1138 binary. It will be called u-boot.dtb. Architecture-specific
1139 code will locate it at run-time. Generally this works by:
1141 cat u-boot.bin u-boot.dtb >image.bin
1143 and in fact, U-Boot does this for you, creating a file called
1144 u-boot-dtb.bin which is useful in the common case. You can
1145 still use the individual files if you need something more
1150 If this variable is defined, it enables watchdog
1151 support for the SoC. There must be support in the SoC
1152 specific code for a watchdog. For the 8xx and 8260
1153 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1154 register. When supported for a specific SoC is
1155 available, then no further board specific code should
1156 be needed to use it.
1159 When using a watchdog circuitry external to the used
1160 SoC, then define this variable and provide board
1161 specific code for the "hw_watchdog_reset" function.
1163 CONFIG_AT91_HW_WDT_TIMEOUT
1164 specify the timeout in seconds. default 2 seconds.
1167 CONFIG_VERSION_VARIABLE
1168 If this variable is defined, an environment variable
1169 named "ver" is created by U-Boot showing the U-Boot
1170 version as printed by the "version" command.
1171 Any change to this variable will be reverted at the
1176 When CONFIG_CMD_DATE is selected, the type of the RTC
1177 has to be selected, too. Define exactly one of the
1180 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1181 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1182 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1183 CONFIG_RTC_MC146818 - use MC146818 RTC
1184 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1185 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1186 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1187 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1188 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1189 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1190 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1191 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1192 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1195 Note that if the RTC uses I2C, then the I2C interface
1196 must also be configured. See I2C Support, below.
1199 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1201 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1202 chip-ngpio pairs that tell the PCA953X driver the number of
1203 pins supported by a particular chip.
1205 Note that if the GPIO device uses I2C, then the I2C interface
1206 must also be configured. See I2C Support, below.
1209 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1210 accesses and can checksum them or write a list of them out
1211 to memory. See the 'iotrace' command for details. This is
1212 useful for testing device drivers since it can confirm that
1213 the driver behaves the same way before and after a code
1214 change. Currently this is supported on sandbox and arm. To
1215 add support for your architecture, add '#include <iotrace.h>'
1216 to the bottom of arch/<arch>/include/asm/io.h and test.
1218 Example output from the 'iotrace stats' command is below.
1219 Note that if the trace buffer is exhausted, the checksum will
1220 still continue to operate.
1223 Start: 10000000 (buffer start address)
1224 Size: 00010000 (buffer size)
1225 Offset: 00000120 (current buffer offset)
1226 Output: 10000120 (start + offset)
1227 Count: 00000018 (number of trace records)
1228 CRC32: 9526fb66 (CRC32 of all trace records)
1230 - Timestamp Support:
1232 When CONFIG_TIMESTAMP is selected, the timestamp
1233 (date and time) of an image is printed by image
1234 commands like bootm or iminfo. This option is
1235 automatically enabled when you select CONFIG_CMD_DATE .
1237 - Partition Labels (disklabels) Supported:
1238 Zero or more of the following:
1239 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1240 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1241 Intel architecture, USB sticks, etc.
1242 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1243 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1244 bootloader. Note 2TB partition limit; see
1246 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1248 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1249 CONFIG_CMD_SCSI) you must configure support for at
1250 least one non-MTD partition type as well.
1253 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1254 board configurations files but used nowhere!
1256 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1257 be performed by calling the function
1258 ide_set_reset(int reset)
1259 which has to be defined in a board specific file
1264 Set this to enable ATAPI support.
1269 Set this to enable support for disks larger than 137GB
1270 Also look at CONFIG_SYS_64BIT_LBA.
1271 Whithout these , LBA48 support uses 32bit variables and will 'only'
1272 support disks up to 2.1TB.
1274 CONFIG_SYS_64BIT_LBA:
1275 When enabled, makes the IDE subsystem use 64bit sector addresses.
1279 At the moment only there is only support for the
1280 SYM53C8XX SCSI controller; define
1281 CONFIG_SCSI_SYM53C8XX to enable it.
1283 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1284 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1285 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1286 maximum numbers of LUNs, SCSI ID's and target
1288 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1290 The environment variable 'scsidevs' is set to the number of
1291 SCSI devices found during the last scan.
1293 - NETWORK Support (PCI):
1295 Support for Intel 8254x/8257x gigabit chips.
1298 Utility code for direct access to the SPI bus on Intel 8257x.
1299 This does not do anything useful unless you set at least one
1300 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1302 CONFIG_E1000_SPI_GENERIC
1303 Allow generic access to the SPI bus on the Intel 8257x, for
1304 example with the "sspi" command.
1307 Management command for E1000 devices. When used on devices
1308 with SPI support you can reprogram the EEPROM from U-Boot.
1311 Support for Intel 82557/82559/82559ER chips.
1312 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1313 write routine for first time initialisation.
1316 Support for Digital 2114x chips.
1317 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1318 modem chip initialisation (KS8761/QS6611).
1321 Support for National dp83815 chips.
1324 Support for National dp8382[01] gigabit chips.
1326 - NETWORK Support (other):
1328 CONFIG_DRIVER_AT91EMAC
1329 Support for AT91RM9200 EMAC.
1332 Define this to use reduced MII inteface
1334 CONFIG_DRIVER_AT91EMAC_QUIET
1335 If this defined, the driver is quiet.
1336 The driver doen't show link status messages.
1338 CONFIG_CALXEDA_XGMAC
1339 Support for the Calxeda XGMAC device
1342 Support for SMSC's LAN91C96 chips.
1344 CONFIG_LAN91C96_BASE
1345 Define this to hold the physical address
1346 of the LAN91C96's I/O space
1348 CONFIG_LAN91C96_USE_32_BIT
1349 Define this to enable 32 bit addressing
1352 Support for SMSC's LAN91C111 chip
1354 CONFIG_SMC91111_BASE
1355 Define this to hold the physical address
1356 of the device (I/O space)
1358 CONFIG_SMC_USE_32_BIT
1359 Define this if data bus is 32 bits
1361 CONFIG_SMC_USE_IOFUNCS
1362 Define this to use i/o functions instead of macros
1363 (some hardware wont work with macros)
1365 CONFIG_DRIVER_TI_EMAC
1366 Support for davinci emac
1368 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1369 Define this if you have more then 3 PHYs.
1372 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1374 CONFIG_FTGMAC100_EGIGA
1375 Define this to use GE link update with gigabit PHY.
1376 Define this if FTGMAC100 is connected to gigabit PHY.
1377 If your system has 10/100 PHY only, it might not occur
1378 wrong behavior. Because PHY usually return timeout or
1379 useless data when polling gigabit status and gigabit
1380 control registers. This behavior won't affect the
1381 correctnessof 10/100 link speed update.
1384 Support for SMSC's LAN911x and LAN921x chips
1387 Define this to hold the physical address
1388 of the device (I/O space)
1390 CONFIG_SMC911X_32_BIT
1391 Define this if data bus is 32 bits
1393 CONFIG_SMC911X_16_BIT
1394 Define this if data bus is 16 bits. If your processor
1395 automatically converts one 32 bit word to two 16 bit
1396 words you may also try CONFIG_SMC911X_32_BIT.
1399 Support for Renesas on-chip Ethernet controller
1401 CONFIG_SH_ETHER_USE_PORT
1402 Define the number of ports to be used
1404 CONFIG_SH_ETHER_PHY_ADDR
1405 Define the ETH PHY's address
1407 CONFIG_SH_ETHER_CACHE_WRITEBACK
1408 If this option is set, the driver enables cache flush.
1412 Support for PWM modul on the imx6.
1416 Support TPM devices.
1418 CONFIG_TPM_TIS_INFINEON
1419 Support for Infineon i2c bus TPM devices. Only one device
1420 per system is supported at this time.
1422 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1423 Define the burst count bytes upper limit
1426 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1428 CONFIG_TPM_ST33ZP24_I2C
1429 Support for STMicroelectronics ST33ZP24 I2C devices.
1430 Requires TPM_ST33ZP24 and I2C.
1432 CONFIG_TPM_ST33ZP24_SPI
1433 Support for STMicroelectronics ST33ZP24 SPI devices.
1434 Requires TPM_ST33ZP24 and SPI.
1436 CONFIG_TPM_ATMEL_TWI
1437 Support for Atmel TWI TPM device. Requires I2C support.
1440 Support for generic parallel port TPM devices. Only one device
1441 per system is supported at this time.
1443 CONFIG_TPM_TIS_BASE_ADDRESS
1444 Base address where the generic TPM device is mapped
1445 to. Contemporary x86 systems usually map it at
1449 Add tpm monitor functions.
1450 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1451 provides monitor access to authorized functions.
1454 Define this to enable the TPM support library which provides
1455 functional interfaces to some TPM commands.
1456 Requires support for a TPM device.
1458 CONFIG_TPM_AUTH_SESSIONS
1459 Define this to enable authorized functions in the TPM library.
1460 Requires CONFIG_TPM and CONFIG_SHA1.
1463 At the moment only the UHCI host controller is
1464 supported (PIP405, MIP405, MPC5200); define
1465 CONFIG_USB_UHCI to enable it.
1466 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1467 and define CONFIG_USB_STORAGE to enable the USB
1470 Supported are USB Keyboards and USB Floppy drives
1472 MPC5200 USB requires additional defines:
1474 for 528 MHz Clock: 0x0001bbbb
1478 for differential drivers: 0x00001000
1479 for single ended drivers: 0x00005000
1480 for differential drivers on PSC3: 0x00000100
1481 for single ended drivers on PSC3: 0x00004100
1482 CONFIG_SYS_USB_EVENT_POLL
1483 May be defined to allow interrupt polling
1484 instead of using asynchronous interrupts
1486 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1487 txfilltuning field in the EHCI controller on reset.
1489 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1490 HW module registers.
1493 Define the below if you wish to use the USB console.
1494 Once firmware is rebuilt from a serial console issue the
1495 command "setenv stdin usbtty; setenv stdout usbtty" and
1496 attach your USB cable. The Unix command "dmesg" should print
1497 it has found a new device. The environment variable usbtty
1498 can be set to gserial or cdc_acm to enable your device to
1499 appear to a USB host as a Linux gserial device or a
1500 Common Device Class Abstract Control Model serial device.
1501 If you select usbtty = gserial you should be able to enumerate
1503 # modprobe usbserial vendor=0xVendorID product=0xProductID
1504 else if using cdc_acm, simply setting the environment
1505 variable usbtty to be cdc_acm should suffice. The following
1506 might be defined in YourBoardName.h
1509 Define this to build a UDC device
1512 Define this to have a tty type of device available to
1513 talk to the UDC device
1516 Define this to enable the high speed support for usb
1517 device and usbtty. If this feature is enabled, a routine
1518 int is_usbd_high_speed(void)
1519 also needs to be defined by the driver to dynamically poll
1520 whether the enumeration has succeded at high speed or full
1523 CONFIG_SYS_CONSOLE_IS_IN_ENV
1524 Define this if you want stdin, stdout &/or stderr to
1528 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1529 Derive USB clock from external clock "blah"
1530 - CONFIG_SYS_USB_EXTC_CLK 0x02
1532 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1533 Derive USB clock from brgclk
1534 - CONFIG_SYS_USB_BRG_CLK 0x04
1536 If you have a USB-IF assigned VendorID then you may wish to
1537 define your own vendor specific values either in BoardName.h
1538 or directly in usbd_vendor_info.h. If you don't define
1539 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1540 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1541 should pretend to be a Linux device to it's target host.
1543 CONFIG_USBD_MANUFACTURER
1544 Define this string as the name of your company for
1545 - CONFIG_USBD_MANUFACTURER "my company"
1547 CONFIG_USBD_PRODUCT_NAME
1548 Define this string as the name of your product
1549 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1551 CONFIG_USBD_VENDORID
1552 Define this as your assigned Vendor ID from the USB
1553 Implementors Forum. This *must* be a genuine Vendor ID
1554 to avoid polluting the USB namespace.
1555 - CONFIG_USBD_VENDORID 0xFFFF
1557 CONFIG_USBD_PRODUCTID
1558 Define this as the unique Product ID
1560 - CONFIG_USBD_PRODUCTID 0xFFFF
1562 - ULPI Layer Support:
1563 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1564 the generic ULPI layer. The generic layer accesses the ULPI PHY
1565 via the platform viewport, so you need both the genric layer and
1566 the viewport enabled. Currently only Chipidea/ARC based
1567 viewport is supported.
1568 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1569 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1570 If your ULPI phy needs a different reference clock than the
1571 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1572 the appropriate value in Hz.
1575 The MMC controller on the Intel PXA is supported. To
1576 enable this define CONFIG_MMC. The MMC can be
1577 accessed from the boot prompt by mapping the device
1578 to physical memory similar to flash. Command line is
1579 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1580 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1583 Support for Renesas on-chip MMCIF controller
1585 CONFIG_SH_MMCIF_ADDR
1586 Define the base address of MMCIF registers
1589 Define the clock frequency for MMCIF
1592 Enable the generic MMC driver
1594 CONFIG_SUPPORT_EMMC_BOOT
1595 Enable some additional features of the eMMC boot partitions.
1597 CONFIG_SUPPORT_EMMC_RPMB
1598 Enable the commands for reading, writing and programming the
1599 key for the Replay Protection Memory Block partition in eMMC.
1601 - USB Device Firmware Update (DFU) class support:
1602 CONFIG_USB_FUNCTION_DFU
1603 This enables the USB portion of the DFU USB class
1606 This enables the command "dfu" which is used to have
1607 U-Boot create a DFU class device via USB. This command
1608 requires that the "dfu_alt_info" environment variable be
1609 set and define the alt settings to expose to the host.
1612 This enables support for exposing (e)MMC devices via DFU.
1615 This enables support for exposing NAND devices via DFU.
1618 This enables support for exposing RAM via DFU.
1619 Note: DFU spec refer to non-volatile memory usage, but
1620 allow usages beyond the scope of spec - here RAM usage,
1621 one that would help mostly the developer.
1623 CONFIG_SYS_DFU_DATA_BUF_SIZE
1624 Dfu transfer uses a buffer before writing data to the
1625 raw storage device. Make the size (in bytes) of this buffer
1626 configurable. The size of this buffer is also configurable
1627 through the "dfu_bufsiz" environment variable.
1629 CONFIG_SYS_DFU_MAX_FILE_SIZE
1630 When updating files rather than the raw storage device,
1631 we use a static buffer to copy the file into and then write
1632 the buffer once we've been given the whole file. Define
1633 this to the maximum filesize (in bytes) for the buffer.
1634 Default is 4 MiB if undefined.
1636 DFU_DEFAULT_POLL_TIMEOUT
1637 Poll timeout [ms], is the timeout a device can send to the
1638 host. The host must wait for this timeout before sending
1639 a subsequent DFU_GET_STATUS request to the device.
1641 DFU_MANIFEST_POLL_TIMEOUT
1642 Poll timeout [ms], which the device sends to the host when
1643 entering dfuMANIFEST state. Host waits this timeout, before
1644 sending again an USB request to the device.
1646 - USB Device Android Fastboot support:
1647 CONFIG_USB_FUNCTION_FASTBOOT
1648 This enables the USB part of the fastboot gadget
1651 This enables the command "fastboot" which enables the Android
1652 fastboot mode for the platform's USB device. Fastboot is a USB
1653 protocol for downloading images, flashing and device control
1654 used on Android devices.
1655 See doc/README.android-fastboot for more information.
1657 CONFIG_ANDROID_BOOT_IMAGE
1658 This enables support for booting images which use the Android
1659 image format header.
1661 CONFIG_FASTBOOT_BUF_ADDR
1662 The fastboot protocol requires a large memory buffer for
1663 downloads. Define this to the starting RAM address to use for
1666 CONFIG_FASTBOOT_BUF_SIZE
1667 The fastboot protocol requires a large memory buffer for
1668 downloads. This buffer should be as large as possible for a
1669 platform. Define this to the size available RAM for fastboot.
1671 CONFIG_FASTBOOT_FLASH
1672 The fastboot protocol includes a "flash" command for writing
1673 the downloaded image to a non-volatile storage device. Define
1674 this to enable the "fastboot flash" command.
1676 CONFIG_FASTBOOT_FLASH_MMC_DEV
1677 The fastboot "flash" command requires additional information
1678 regarding the non-volatile storage device. Define this to
1679 the eMMC device that fastboot should use to store the image.
1681 CONFIG_FASTBOOT_GPT_NAME
1682 The fastboot "flash" command supports writing the downloaded
1683 image to the Protective MBR and the Primary GUID Partition
1684 Table. (Additionally, this downloaded image is post-processed
1685 to generate and write the Backup GUID Partition Table.)
1686 This occurs when the specified "partition name" on the
1687 "fastboot flash" command line matches this value.
1688 Default is GPT_ENTRY_NAME (currently "gpt") if undefined.
1690 - Journaling Flash filesystem support:
1691 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1692 CONFIG_JFFS2_NAND_DEV
1693 Define these for a default partition on a NAND device
1695 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1696 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1697 Define these for a default partition on a NOR device
1699 CONFIG_SYS_JFFS_CUSTOM_PART
1700 Define this to create an own partition. You have to provide a
1701 function struct part_info* jffs2_part_info(int part_num)
1703 If you define only one JFFS2 partition you may also want to
1704 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1705 to disable the command chpart. This is the default when you
1706 have not defined a custom partition
1708 - FAT(File Allocation Table) filesystem write function support:
1711 Define this to enable support for saving memory data as a
1712 file in FAT formatted partition.
1714 This will also enable the command "fatwrite" enabling the
1715 user to write files to FAT.
1717 CBFS (Coreboot Filesystem) support
1720 Define this to enable support for reading from a Coreboot
1721 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1724 - FAT(File Allocation Table) filesystem cluster size:
1725 CONFIG_FS_FAT_MAX_CLUSTSIZE
1727 Define the max cluster size for fat operations else
1728 a default value of 65536 will be defined.
1731 See Kconfig help for available keyboard drivers.
1735 Define this to enable a custom keyboard support.
1736 This simply calls drv_keyboard_init() which must be
1737 defined in your board-specific files. This option is deprecated
1738 and is only used by novena. For new boards, use driver model
1744 Define this to enable video support (for output to
1747 CONFIG_VIDEO_CT69000
1749 Enable Chips & Technologies 69000 Video chip
1751 CONFIG_VIDEO_SMI_LYNXEM
1752 Enable Silicon Motion SMI 712/710/810 Video chip. The
1753 video output is selected via environment 'videoout'
1754 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1757 For the CT69000 and SMI_LYNXEM drivers, videomode is
1758 selected via environment 'videomode'. Two different ways
1760 - "videomode=num" 'num' is a standard LiLo mode numbers.
1761 Following standard modes are supported (* is default):
1763 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1764 -------------+---------------------------------------------
1765 8 bits | 0x301* 0x303 0x305 0x161 0x307
1766 15 bits | 0x310 0x313 0x316 0x162 0x319
1767 16 bits | 0x311 0x314 0x317 0x163 0x31A
1768 24 bits | 0x312 0x315 0x318 ? 0x31B
1769 -------------+---------------------------------------------
1770 (i.e. setenv videomode 317; saveenv; reset;)
1772 - "videomode=bootargs" all the video parameters are parsed
1773 from the bootargs. (See drivers/video/videomodes.c)
1776 CONFIG_VIDEO_SED13806
1777 Enable Epson SED13806 driver. This driver supports 8bpp
1778 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1779 or CONFIG_VIDEO_SED13806_16BPP
1782 Enable the Freescale DIU video driver. Reference boards for
1783 SOCs that have a DIU should define this macro to enable DIU
1784 support, and should also define these other macros:
1790 CONFIG_VIDEO_SW_CURSOR
1791 CONFIG_VGA_AS_SINGLE_DEVICE
1793 CONFIG_VIDEO_BMP_LOGO
1795 The DIU driver will look for the 'video-mode' environment
1796 variable, and if defined, enable the DIU as a console during
1797 boot. See the documentation file README.video for a
1798 description of this variable.
1800 - LCD Support: CONFIG_LCD
1802 Define this to enable LCD support (for output to LCD
1803 display); also select one of the supported displays
1804 by defining one of these:
1808 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1810 CONFIG_NEC_NL6448AC33:
1812 NEC NL6448AC33-18. Active, color, single scan.
1814 CONFIG_NEC_NL6448BC20
1816 NEC NL6448BC20-08. 6.5", 640x480.
1817 Active, color, single scan.
1819 CONFIG_NEC_NL6448BC33_54
1821 NEC NL6448BC33-54. 10.4", 640x480.
1822 Active, color, single scan.
1826 Sharp 320x240. Active, color, single scan.
1827 It isn't 16x9, and I am not sure what it is.
1829 CONFIG_SHARP_LQ64D341
1831 Sharp LQ64D341 display, 640x480.
1832 Active, color, single scan.
1836 HLD1045 display, 640x480.
1837 Active, color, single scan.
1841 Optrex CBL50840-2 NF-FW 99 22 M5
1843 Hitachi LMG6912RPFC-00T
1847 320x240. Black & white.
1849 Normally display is black on white background; define
1850 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1852 CONFIG_LCD_ALIGNMENT
1854 Normally the LCD is page-aligned (typically 4KB). If this is
1855 defined then the LCD will be aligned to this value instead.
1856 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1857 here, since it is cheaper to change data cache settings on
1858 a per-section basis.
1860 CONFIG_CONSOLE_SCROLL_LINES
1862 When the console need to be scrolled, this is the number of
1863 lines to scroll by. It defaults to 1. Increasing this makes
1864 the console jump but can help speed up operation when scrolling
1869 Sometimes, for example if the display is mounted in portrait
1870 mode or even if it's mounted landscape but rotated by 180degree,
1871 we need to rotate our content of the display relative to the
1872 framebuffer, so that user can read the messages which are
1874 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1875 initialized with a given rotation from "vl_rot" out of
1876 "vidinfo_t" which is provided by the board specific code.
1877 The value for vl_rot is coded as following (matching to
1878 fbcon=rotate:<n> linux-kernel commandline):
1879 0 = no rotation respectively 0 degree
1880 1 = 90 degree rotation
1881 2 = 180 degree rotation
1882 3 = 270 degree rotation
1884 If CONFIG_LCD_ROTATION is not defined, the console will be
1885 initialized with 0degree rotation.
1889 Support drawing of RLE8-compressed bitmaps on the LCD.
1893 Enables an 'i2c edid' command which can read EDID
1894 information over I2C from an attached LCD display.
1896 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1898 If this option is set, the environment is checked for
1899 a variable "splashimage". If found, the usual display
1900 of logo, copyright and system information on the LCD
1901 is suppressed and the BMP image at the address
1902 specified in "splashimage" is loaded instead. The
1903 console is redirected to the "nulldev", too. This
1904 allows for a "silent" boot where a splash screen is
1905 loaded very quickly after power-on.
1907 CONFIG_SPLASHIMAGE_GUARD
1909 If this option is set, then U-Boot will prevent the environment
1910 variable "splashimage" from being set to a problematic address
1911 (see README.displaying-bmps).
1912 This option is useful for targets where, due to alignment
1913 restrictions, an improperly aligned BMP image will cause a data
1914 abort. If you think you will not have problems with unaligned
1915 accesses (for example because your toolchain prevents them)
1916 there is no need to set this option.
1918 CONFIG_SPLASH_SCREEN_ALIGN
1920 If this option is set the splash image can be freely positioned
1921 on the screen. Environment variable "splashpos" specifies the
1922 position as "x,y". If a positive number is given it is used as
1923 number of pixel from left/top. If a negative number is given it
1924 is used as number of pixel from right/bottom. You can also
1925 specify 'm' for centering the image.
1928 setenv splashpos m,m
1929 => image at center of screen
1931 setenv splashpos 30,20
1932 => image at x = 30 and y = 20
1934 setenv splashpos -10,m
1935 => vertically centered image
1936 at x = dspWidth - bmpWidth - 9
1938 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1940 If this option is set, additionally to standard BMP
1941 images, gzipped BMP images can be displayed via the
1942 splashscreen support or the bmp command.
1944 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1946 If this option is set, 8-bit RLE compressed BMP images
1947 can be displayed via the splashscreen support or the
1950 - Do compressing for memory range:
1953 If this option is set, it would use zlib deflate method
1954 to compress the specified memory at its best effort.
1956 - Compression support:
1959 Enabled by default to support gzip compressed images.
1963 If this option is set, support for bzip2 compressed
1964 images is included. If not, only uncompressed and gzip
1965 compressed images are supported.
1967 NOTE: the bzip2 algorithm requires a lot of RAM, so
1968 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1973 If this option is set, support for lzma compressed
1976 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1977 requires an amount of dynamic memory that is given by the
1980 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1982 Where lc and lp stand for, respectively, Literal context bits
1983 and Literal pos bits.
1985 This value is upper-bounded by 14MB in the worst case. Anyway,
1986 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1987 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1988 a very small buffer.
1990 Use the lzmainfo tool to determinate the lc and lp values and
1991 then calculate the amount of needed dynamic memory (ensuring
1992 the appropriate CONFIG_SYS_MALLOC_LEN value).
1996 If this option is set, support for LZO compressed images
2002 The address of PHY on MII bus.
2004 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
2006 The clock frequency of the MII bus
2010 If this option is set, support for speed/duplex
2011 detection of gigabit PHY is included.
2013 CONFIG_PHY_RESET_DELAY
2015 Some PHY like Intel LXT971A need extra delay after
2016 reset before any MII register access is possible.
2017 For such PHY, set this option to the usec delay
2018 required. (minimum 300usec for LXT971A)
2020 CONFIG_PHY_CMD_DELAY (ppc4xx)
2022 Some PHY like Intel LXT971A need extra delay after
2023 command issued before MII status register can be read
2028 Define a default value for the IP address to use for
2029 the default Ethernet interface, in case this is not
2030 determined through e.g. bootp.
2031 (Environment variable "ipaddr")
2033 - Server IP address:
2036 Defines a default value for the IP address of a TFTP
2037 server to contact when using the "tftboot" command.
2038 (Environment variable "serverip")
2040 CONFIG_KEEP_SERVERADDR
2042 Keeps the server's MAC address, in the env 'serveraddr'
2043 for passing to bootargs (like Linux's netconsole option)
2045 - Gateway IP address:
2048 Defines a default value for the IP address of the
2049 default router where packets to other networks are
2051 (Environment variable "gatewayip")
2056 Defines a default value for the subnet mask (or
2057 routing prefix) which is used to determine if an IP
2058 address belongs to the local subnet or needs to be
2059 forwarded through a router.
2060 (Environment variable "netmask")
2062 - Multicast TFTP Mode:
2065 Defines whether you want to support multicast TFTP as per
2066 rfc-2090; for example to work with atftp. Lets lots of targets
2067 tftp down the same boot image concurrently. Note: the Ethernet
2068 driver in use must provide a function: mcast() to join/leave a
2071 - BOOTP Recovery Mode:
2072 CONFIG_BOOTP_RANDOM_DELAY
2074 If you have many targets in a network that try to
2075 boot using BOOTP, you may want to avoid that all
2076 systems send out BOOTP requests at precisely the same
2077 moment (which would happen for instance at recovery
2078 from a power failure, when all systems will try to
2079 boot, thus flooding the BOOTP server. Defining
2080 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2081 inserted before sending out BOOTP requests. The
2082 following delays are inserted then:
2084 1st BOOTP request: delay 0 ... 1 sec
2085 2nd BOOTP request: delay 0 ... 2 sec
2086 3rd BOOTP request: delay 0 ... 4 sec
2088 BOOTP requests: delay 0 ... 8 sec
2090 CONFIG_BOOTP_ID_CACHE_SIZE
2092 BOOTP packets are uniquely identified using a 32-bit ID. The
2093 server will copy the ID from client requests to responses and
2094 U-Boot will use this to determine if it is the destination of
2095 an incoming response. Some servers will check that addresses
2096 aren't in use before handing them out (usually using an ARP
2097 ping) and therefore take up to a few hundred milliseconds to
2098 respond. Network congestion may also influence the time it
2099 takes for a response to make it back to the client. If that
2100 time is too long, U-Boot will retransmit requests. In order
2101 to allow earlier responses to still be accepted after these
2102 retransmissions, U-Boot's BOOTP client keeps a small cache of
2103 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2104 cache. The default is to keep IDs for up to four outstanding
2105 requests. Increasing this will allow U-Boot to accept offers
2106 from a BOOTP client in networks with unusually high latency.
2108 - DHCP Advanced Options:
2109 You can fine tune the DHCP functionality by defining
2110 CONFIG_BOOTP_* symbols:
2112 CONFIG_BOOTP_SUBNETMASK
2113 CONFIG_BOOTP_GATEWAY
2114 CONFIG_BOOTP_HOSTNAME
2115 CONFIG_BOOTP_NISDOMAIN
2116 CONFIG_BOOTP_BOOTPATH
2117 CONFIG_BOOTP_BOOTFILESIZE
2120 CONFIG_BOOTP_SEND_HOSTNAME
2121 CONFIG_BOOTP_NTPSERVER
2122 CONFIG_BOOTP_TIMEOFFSET
2123 CONFIG_BOOTP_VENDOREX
2124 CONFIG_BOOTP_MAY_FAIL
2126 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2127 environment variable, not the BOOTP server.
2129 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2130 after the configured retry count, the call will fail
2131 instead of starting over. This can be used to fail over
2132 to Link-local IP address configuration if the DHCP server
2135 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2136 serverip from a DHCP server, it is possible that more
2137 than one DNS serverip is offered to the client.
2138 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2139 serverip will be stored in the additional environment
2140 variable "dnsip2". The first DNS serverip is always
2141 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2144 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2145 to do a dynamic update of a DNS server. To do this, they
2146 need the hostname of the DHCP requester.
2147 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2148 of the "hostname" environment variable is passed as
2149 option 12 to the DHCP server.
2151 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2153 A 32bit value in microseconds for a delay between
2154 receiving a "DHCP Offer" and sending the "DHCP Request".
2155 This fixes a problem with certain DHCP servers that don't
2156 respond 100% of the time to a "DHCP request". E.g. On an
2157 AT91RM9200 processor running at 180MHz, this delay needed
2158 to be *at least* 15,000 usec before a Windows Server 2003
2159 DHCP server would reply 100% of the time. I recommend at
2160 least 50,000 usec to be safe. The alternative is to hope
2161 that one of the retries will be successful but note that
2162 the DHCP timeout and retry process takes a longer than
2165 - Link-local IP address negotiation:
2166 Negotiate with other link-local clients on the local network
2167 for an address that doesn't require explicit configuration.
2168 This is especially useful if a DHCP server cannot be guaranteed
2169 to exist in all environments that the device must operate.
2171 See doc/README.link-local for more information.
2174 CONFIG_CDP_DEVICE_ID
2176 The device id used in CDP trigger frames.
2178 CONFIG_CDP_DEVICE_ID_PREFIX
2180 A two character string which is prefixed to the MAC address
2185 A printf format string which contains the ascii name of
2186 the port. Normally is set to "eth%d" which sets
2187 eth0 for the first Ethernet, eth1 for the second etc.
2189 CONFIG_CDP_CAPABILITIES
2191 A 32bit integer which indicates the device capabilities;
2192 0x00000010 for a normal host which does not forwards.
2196 An ascii string containing the version of the software.
2200 An ascii string containing the name of the platform.
2204 A 32bit integer sent on the trigger.
2206 CONFIG_CDP_POWER_CONSUMPTION
2208 A 16bit integer containing the power consumption of the
2209 device in .1 of milliwatts.
2211 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2213 A byte containing the id of the VLAN.
2215 - Status LED: CONFIG_STATUS_LED
2217 Several configurations allow to display the current
2218 status using a LED. For instance, the LED will blink
2219 fast while running U-Boot code, stop blinking as
2220 soon as a reply to a BOOTP request was received, and
2221 start blinking slow once the Linux kernel is running
2222 (supported by a status LED driver in the Linux
2223 kernel). Defining CONFIG_STATUS_LED enables this
2229 The status LED can be connected to a GPIO pin.
2230 In such cases, the gpio_led driver can be used as a
2231 status LED backend implementation. Define CONFIG_GPIO_LED
2232 to include the gpio_led driver in the U-Boot binary.
2234 CONFIG_GPIO_LED_INVERTED_TABLE
2235 Some GPIO connected LEDs may have inverted polarity in which
2236 case the GPIO high value corresponds to LED off state and
2237 GPIO low value corresponds to LED on state.
2238 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2239 with a list of GPIO LEDs that have inverted polarity.
2241 - CAN Support: CONFIG_CAN_DRIVER
2243 Defining CONFIG_CAN_DRIVER enables CAN driver support
2244 on those systems that support this (optional)
2245 feature, like the TQM8xxL modules.
2247 - I2C Support: CONFIG_SYS_I2C
2249 This enable the NEW i2c subsystem, and will allow you to use
2250 i2c commands at the u-boot command line (as long as you set
2251 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2252 based realtime clock chips or other i2c devices. See
2253 common/cmd_i2c.c for a description of the command line
2256 ported i2c driver to the new framework:
2257 - drivers/i2c/soft_i2c.c:
2258 - activate first bus with CONFIG_SYS_I2C_SOFT define
2259 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2260 for defining speed and slave address
2261 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2262 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2263 for defining speed and slave address
2264 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2265 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2266 for defining speed and slave address
2267 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2268 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2269 for defining speed and slave address
2271 - drivers/i2c/fsl_i2c.c:
2272 - activate i2c driver with CONFIG_SYS_I2C_FSL
2273 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2274 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2275 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2277 - If your board supports a second fsl i2c bus, define
2278 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2279 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2280 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2283 - drivers/i2c/tegra_i2c.c:
2284 - activate this driver with CONFIG_SYS_I2C_TEGRA
2285 - This driver adds 4 i2c buses with a fix speed from
2286 100000 and the slave addr 0!
2288 - drivers/i2c/ppc4xx_i2c.c
2289 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2290 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2291 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2293 - drivers/i2c/i2c_mxc.c
2294 - activate this driver with CONFIG_SYS_I2C_MXC
2295 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2296 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2297 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2298 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2299 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2300 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2301 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2302 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2303 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2304 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2305 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2306 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2307 If those defines are not set, default value is 100000
2308 for speed, and 0 for slave.
2310 - drivers/i2c/rcar_i2c.c:
2311 - activate this driver with CONFIG_SYS_I2C_RCAR
2312 - This driver adds 4 i2c buses
2314 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2315 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2316 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2317 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2318 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2319 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2320 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2321 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2322 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2324 - drivers/i2c/sh_i2c.c:
2325 - activate this driver with CONFIG_SYS_I2C_SH
2326 - This driver adds from 2 to 5 i2c buses
2328 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2329 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2330 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2331 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2332 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2333 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2334 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2335 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2336 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2337 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2338 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2339 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2340 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2342 - drivers/i2c/omap24xx_i2c.c
2343 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2344 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2345 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2346 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2347 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2348 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2349 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2350 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2351 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2352 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2353 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2355 - drivers/i2c/zynq_i2c.c
2356 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2357 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2358 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2360 - drivers/i2c/s3c24x0_i2c.c:
2361 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2362 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2363 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2364 with a fix speed from 100000 and the slave addr 0!
2366 - drivers/i2c/ihs_i2c.c
2367 - activate this driver with CONFIG_SYS_I2C_IHS
2368 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2369 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2370 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2371 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2372 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2373 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2374 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2375 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2376 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2377 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2378 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2379 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2380 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2381 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2382 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2383 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2384 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2385 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2386 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2387 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2388 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2392 CONFIG_SYS_NUM_I2C_BUSES
2393 Hold the number of i2c buses you want to use. If you
2394 don't use/have i2c muxes on your i2c bus, this
2395 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2398 CONFIG_SYS_I2C_DIRECT_BUS
2399 define this, if you don't use i2c muxes on your hardware.
2400 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2403 CONFIG_SYS_I2C_MAX_HOPS
2404 define how many muxes are maximal consecutively connected
2405 on one i2c bus. If you not use i2c muxes, omit this
2408 CONFIG_SYS_I2C_BUSES
2409 hold a list of buses you want to use, only used if
2410 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2411 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2412 CONFIG_SYS_NUM_I2C_BUSES = 9:
2414 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2415 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2416 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2417 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2418 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2419 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2420 {1, {I2C_NULL_HOP}}, \
2421 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2422 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2426 bus 0 on adapter 0 without a mux
2427 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2428 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2429 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2430 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2431 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2432 bus 6 on adapter 1 without a mux
2433 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2434 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2436 If you do not have i2c muxes on your board, omit this define.
2438 - Legacy I2C Support: CONFIG_HARD_I2C
2440 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2441 provides the following compelling advantages:
2443 - more than one i2c adapter is usable
2444 - approved multibus support
2445 - better i2c mux support
2447 ** Please consider updating your I2C driver now. **
2449 These enable legacy I2C serial bus commands. Defining
2450 CONFIG_HARD_I2C will include the appropriate I2C driver
2451 for the selected CPU.
2453 This will allow you to use i2c commands at the u-boot
2454 command line (as long as you set CONFIG_CMD_I2C in
2455 CONFIG_COMMANDS) and communicate with i2c based realtime
2456 clock chips. See common/cmd_i2c.c for a description of the
2457 command line interface.
2459 CONFIG_HARD_I2C selects a hardware I2C controller.
2461 There are several other quantities that must also be
2462 defined when you define CONFIG_HARD_I2C.
2464 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2465 to be the frequency (in Hz) at which you wish your i2c bus
2466 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2467 the CPU's i2c node address).
2469 Now, the u-boot i2c code for the mpc8xx
2470 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2471 and so its address should therefore be cleared to 0 (See,
2472 eg, MPC823e User's Manual p.16-473). So, set
2473 CONFIG_SYS_I2C_SLAVE to 0.
2475 CONFIG_SYS_I2C_INIT_MPC5XXX
2477 When a board is reset during an i2c bus transfer
2478 chips might think that the current transfer is still
2479 in progress. Reset the slave devices by sending start
2480 commands until the slave device responds.
2482 That's all that's required for CONFIG_HARD_I2C.
2484 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2485 then the following macros need to be defined (examples are
2486 from include/configs/lwmon.h):
2490 (Optional). Any commands necessary to enable the I2C
2491 controller or configure ports.
2493 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2497 (Only for MPC8260 CPU). The I/O port to use (the code
2498 assumes both bits are on the same port). Valid values
2499 are 0..3 for ports A..D.
2503 The code necessary to make the I2C data line active
2504 (driven). If the data line is open collector, this
2507 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2511 The code necessary to make the I2C data line tri-stated
2512 (inactive). If the data line is open collector, this
2515 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2519 Code that returns true if the I2C data line is high,
2522 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2526 If <bit> is true, sets the I2C data line high. If it
2527 is false, it clears it (low).
2529 eg: #define I2C_SDA(bit) \
2530 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2531 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2535 If <bit> is true, sets the I2C clock line high. If it
2536 is false, it clears it (low).
2538 eg: #define I2C_SCL(bit) \
2539 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2540 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2544 This delay is invoked four times per clock cycle so this
2545 controls the rate of data transfer. The data rate thus
2546 is 1 / (I2C_DELAY * 4). Often defined to be something
2549 #define I2C_DELAY udelay(2)
2551 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2553 If your arch supports the generic GPIO framework (asm/gpio.h),
2554 then you may alternatively define the two GPIOs that are to be
2555 used as SCL / SDA. Any of the previous I2C_xxx macros will
2556 have GPIO-based defaults assigned to them as appropriate.
2558 You should define these to the GPIO value as given directly to
2559 the generic GPIO functions.
2561 CONFIG_SYS_I2C_INIT_BOARD
2563 When a board is reset during an i2c bus transfer
2564 chips might think that the current transfer is still
2565 in progress. On some boards it is possible to access
2566 the i2c SCLK line directly, either by using the
2567 processor pin as a GPIO or by having a second pin
2568 connected to the bus. If this option is defined a
2569 custom i2c_init_board() routine in boards/xxx/board.c
2570 is run early in the boot sequence.
2572 CONFIG_SYS_I2C_BOARD_LATE_INIT
2574 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2575 defined a custom i2c_board_late_init() routine in
2576 boards/xxx/board.c is run AFTER the operations in i2c_init()
2577 is completed. This callpoint can be used to unreset i2c bus
2578 using CPU i2c controller register accesses for CPUs whose i2c
2579 controller provide such a method. It is called at the end of
2580 i2c_init() to allow i2c_init operations to setup the i2c bus
2581 controller on the CPU (e.g. setting bus speed & slave address).
2583 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2585 This option enables configuration of bi_iic_fast[] flags
2586 in u-boot bd_info structure based on u-boot environment
2587 variable "i2cfast". (see also i2cfast)
2589 CONFIG_I2C_MULTI_BUS
2591 This option allows the use of multiple I2C buses, each of which
2592 must have a controller. At any point in time, only one bus is
2593 active. To switch to a different bus, use the 'i2c dev' command.
2594 Note that bus numbering is zero-based.
2596 CONFIG_SYS_I2C_NOPROBES
2598 This option specifies a list of I2C devices that will be skipped
2599 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2600 is set, specify a list of bus-device pairs. Otherwise, specify
2601 a 1D array of device addresses
2604 #undef CONFIG_I2C_MULTI_BUS
2605 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2607 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2609 #define CONFIG_I2C_MULTI_BUS
2610 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2612 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2614 CONFIG_SYS_SPD_BUS_NUM
2616 If defined, then this indicates the I2C bus number for DDR SPD.
2617 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2619 CONFIG_SYS_RTC_BUS_NUM
2621 If defined, then this indicates the I2C bus number for the RTC.
2622 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2624 CONFIG_SYS_DTT_BUS_NUM
2626 If defined, then this indicates the I2C bus number for the DTT.
2627 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2629 CONFIG_SYS_I2C_DTT_ADDR:
2631 If defined, specifies the I2C address of the DTT device.
2632 If not defined, then U-Boot uses predefined value for
2633 specified DTT device.
2635 CONFIG_SOFT_I2C_READ_REPEATED_START
2637 defining this will force the i2c_read() function in
2638 the soft_i2c driver to perform an I2C repeated start
2639 between writing the address pointer and reading the
2640 data. If this define is omitted the default behaviour
2641 of doing a stop-start sequence will be used. Most I2C
2642 devices can use either method, but some require one or
2645 - SPI Support: CONFIG_SPI
2647 Enables SPI driver (so far only tested with
2648 SPI EEPROM, also an instance works with Crystal A/D and
2649 D/As on the SACSng board)
2653 Enables the driver for SPI controller on SuperH. Currently
2654 only SH7757 is supported.
2658 Enables a software (bit-bang) SPI driver rather than
2659 using hardware support. This is a general purpose
2660 driver that only requires three general I/O port pins
2661 (two outputs, one input) to function. If this is
2662 defined, the board configuration must define several
2663 SPI configuration items (port pins to use, etc). For
2664 an example, see include/configs/sacsng.h.
2668 Enables a hardware SPI driver for general-purpose reads
2669 and writes. As with CONFIG_SOFT_SPI, the board configuration
2670 must define a list of chip-select function pointers.
2671 Currently supported on some MPC8xxx processors. For an
2672 example, see include/configs/mpc8349emds.h.
2676 Enables the driver for the SPI controllers on i.MX and MXC
2677 SoCs. Currently i.MX31/35/51 are supported.
2679 CONFIG_SYS_SPI_MXC_WAIT
2680 Timeout for waiting until spi transfer completed.
2681 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2683 - FPGA Support: CONFIG_FPGA
2685 Enables FPGA subsystem.
2687 CONFIG_FPGA_<vendor>
2689 Enables support for specific chip vendors.
2692 CONFIG_FPGA_<family>
2694 Enables support for FPGA family.
2695 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2699 Specify the number of FPGA devices to support.
2701 CONFIG_CMD_FPGA_LOADMK
2703 Enable support for fpga loadmk command
2705 CONFIG_CMD_FPGA_LOADP
2707 Enable support for fpga loadp command - load partial bitstream
2709 CONFIG_CMD_FPGA_LOADBP
2711 Enable support for fpga loadbp command - load partial bitstream
2714 CONFIG_SYS_FPGA_PROG_FEEDBACK
2716 Enable printing of hash marks during FPGA configuration.
2718 CONFIG_SYS_FPGA_CHECK_BUSY
2720 Enable checks on FPGA configuration interface busy
2721 status by the configuration function. This option
2722 will require a board or device specific function to
2727 If defined, a function that provides delays in the FPGA
2728 configuration driver.
2730 CONFIG_SYS_FPGA_CHECK_CTRLC
2731 Allow Control-C to interrupt FPGA configuration
2733 CONFIG_SYS_FPGA_CHECK_ERROR
2735 Check for configuration errors during FPGA bitfile
2736 loading. For example, abort during Virtex II
2737 configuration if the INIT_B line goes low (which
2738 indicated a CRC error).
2740 CONFIG_SYS_FPGA_WAIT_INIT
2742 Maximum time to wait for the INIT_B line to de-assert
2743 after PROB_B has been de-asserted during a Virtex II
2744 FPGA configuration sequence. The default time is 500
2747 CONFIG_SYS_FPGA_WAIT_BUSY
2749 Maximum time to wait for BUSY to de-assert during
2750 Virtex II FPGA configuration. The default is 5 ms.
2752 CONFIG_SYS_FPGA_WAIT_CONFIG
2754 Time to wait after FPGA configuration. The default is
2757 - Configuration Management:
2760 Some SoCs need special image types (e.g. U-Boot binary
2761 with a special header) as build targets. By defining
2762 CONFIG_BUILD_TARGET in the SoC / board header, this
2763 special image will be automatically built upon calling
2768 If defined, this string will be added to the U-Boot
2769 version information (U_BOOT_VERSION)
2771 - Vendor Parameter Protection:
2773 U-Boot considers the values of the environment
2774 variables "serial#" (Board Serial Number) and
2775 "ethaddr" (Ethernet Address) to be parameters that
2776 are set once by the board vendor / manufacturer, and
2777 protects these variables from casual modification by
2778 the user. Once set, these variables are read-only,
2779 and write or delete attempts are rejected. You can
2780 change this behaviour:
2782 If CONFIG_ENV_OVERWRITE is #defined in your config
2783 file, the write protection for vendor parameters is
2784 completely disabled. Anybody can change or delete
2787 Alternatively, if you define _both_ an ethaddr in the
2788 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2789 Ethernet address is installed in the environment,
2790 which can be changed exactly ONCE by the user. [The
2791 serial# is unaffected by this, i. e. it remains
2794 The same can be accomplished in a more flexible way
2795 for any variable by configuring the type of access
2796 to allow for those variables in the ".flags" variable
2797 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2802 Define this variable to enable the reservation of
2803 "protected RAM", i. e. RAM which is not overwritten
2804 by U-Boot. Define CONFIG_PRAM to hold the number of
2805 kB you want to reserve for pRAM. You can overwrite
2806 this default value by defining an environment
2807 variable "pram" to the number of kB you want to
2808 reserve. Note that the board info structure will
2809 still show the full amount of RAM. If pRAM is
2810 reserved, a new environment variable "mem" will
2811 automatically be defined to hold the amount of
2812 remaining RAM in a form that can be passed as boot
2813 argument to Linux, for instance like that:
2815 setenv bootargs ... mem=\${mem}
2818 This way you can tell Linux not to use this memory,
2819 either, which results in a memory region that will
2820 not be affected by reboots.
2822 *WARNING* If your board configuration uses automatic
2823 detection of the RAM size, you must make sure that
2824 this memory test is non-destructive. So far, the
2825 following board configurations are known to be
2828 IVMS8, IVML24, SPD8xx, TQM8xxL,
2829 HERMES, IP860, RPXlite, LWMON,
2832 - Access to physical memory region (> 4GB)
2833 Some basic support is provided for operations on memory not
2834 normally accessible to U-Boot - e.g. some architectures
2835 support access to more than 4GB of memory on 32-bit
2836 machines using physical address extension or similar.
2837 Define CONFIG_PHYSMEM to access this basic support, which
2838 currently only supports clearing the memory.
2843 Define this variable to stop the system in case of a
2844 fatal error, so that you have to reset it manually.
2845 This is probably NOT a good idea for an embedded
2846 system where you want the system to reboot
2847 automatically as fast as possible, but it may be
2848 useful during development since you can try to debug
2849 the conditions that lead to the situation.
2851 CONFIG_NET_RETRY_COUNT
2853 This variable defines the number of retries for
2854 network operations like ARP, RARP, TFTP, or BOOTP
2855 before giving up the operation. If not defined, a
2856 default value of 5 is used.
2860 Timeout waiting for an ARP reply in milliseconds.
2864 Timeout in milliseconds used in NFS protocol.
2865 If you encounter "ERROR: Cannot umount" in nfs command,
2866 try longer timeout such as
2867 #define CONFIG_NFS_TIMEOUT 10000UL
2869 - Command Interpreter:
2870 CONFIG_AUTO_COMPLETE
2872 Enable auto completion of commands using TAB.
2874 CONFIG_SYS_PROMPT_HUSH_PS2
2876 This defines the secondary prompt string, which is
2877 printed when the command interpreter needs more input
2878 to complete a command. Usually "> ".
2882 In the current implementation, the local variables
2883 space and global environment variables space are
2884 separated. Local variables are those you define by
2885 simply typing `name=value'. To access a local
2886 variable later on, you have write `$name' or
2887 `${name}'; to execute the contents of a variable
2888 directly type `$name' at the command prompt.
2890 Global environment variables are those you use
2891 setenv/printenv to work with. To run a command stored
2892 in such a variable, you need to use the run command,
2893 and you must not use the '$' sign to access them.
2895 To store commands and special characters in a
2896 variable, please use double quotation marks
2897 surrounding the whole text of the variable, instead
2898 of the backslashes before semicolons and special
2901 - Command Line Editing and History:
2902 CONFIG_CMDLINE_EDITING
2904 Enable editing and History functions for interactive
2905 command line input operations
2907 - Command Line PS1/PS2 support:
2908 CONFIG_CMDLINE_PS_SUPPORT
2910 Enable support for changing the command prompt string
2911 at run-time. Only static string is supported so far.
2912 The string is obtained from environment variables PS1
2915 - Default Environment:
2916 CONFIG_EXTRA_ENV_SETTINGS
2918 Define this to contain any number of null terminated
2919 strings (variable = value pairs) that will be part of
2920 the default environment compiled into the boot image.
2922 For example, place something like this in your
2923 board's config file:
2925 #define CONFIG_EXTRA_ENV_SETTINGS \
2929 Warning: This method is based on knowledge about the
2930 internal format how the environment is stored by the
2931 U-Boot code. This is NOT an official, exported
2932 interface! Although it is unlikely that this format
2933 will change soon, there is no guarantee either.
2934 You better know what you are doing here.
2936 Note: overly (ab)use of the default environment is
2937 discouraged. Make sure to check other ways to preset
2938 the environment like the "source" command or the
2941 CONFIG_ENV_VARS_UBOOT_CONFIG
2943 Define this in order to add variables describing the
2944 U-Boot build configuration to the default environment.
2945 These will be named arch, cpu, board, vendor, and soc.
2947 Enabling this option will cause the following to be defined:
2955 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2957 Define this in order to add variables describing certain
2958 run-time determined information about the hardware to the
2959 environment. These will be named board_name, board_rev.
2961 CONFIG_DELAY_ENVIRONMENT
2963 Normally the environment is loaded when the board is
2964 initialised so that it is available to U-Boot. This inhibits
2965 that so that the environment is not available until
2966 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2967 this is instead controlled by the value of
2968 /config/load-environment.
2970 - Parallel Flash support:
2973 Traditionally U-Boot was run on systems with parallel NOR
2974 flash. This option is used to disable support for parallel NOR
2975 flash. This option should be defined if the board does not have
2978 If this option is not defined one of the generic flash drivers
2979 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2980 selected or the board must provide an implementation of the
2981 flash API (see include/flash.h).
2983 - DataFlash Support:
2984 CONFIG_HAS_DATAFLASH
2986 Defining this option enables DataFlash features and
2987 allows to read/write in Dataflash via the standard
2990 - Serial Flash support
2993 Defining this option enables SPI flash commands
2994 'sf probe/read/write/erase/update'.
2996 Usage requires an initial 'probe' to define the serial
2997 flash parameters, followed by read/write/erase/update
3000 The following defaults may be provided by the platform
3001 to handle the common case when only a single serial
3002 flash is present on the system.
3004 CONFIG_SF_DEFAULT_BUS Bus identifier
3005 CONFIG_SF_DEFAULT_CS Chip-select
3006 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
3007 CONFIG_SF_DEFAULT_SPEED in Hz
3011 Define this option to include a destructive SPI flash
3014 CONFIG_SF_DUAL_FLASH Dual flash memories
3016 Define this option to use dual flash support where two flash
3017 memories can be connected with a given cs line.
3018 Currently Xilinx Zynq qspi supports these type of connections.
3020 - SystemACE Support:
3023 Adding this option adds support for Xilinx SystemACE
3024 chips attached via some sort of local bus. The address
3025 of the chip must also be defined in the
3026 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
3028 #define CONFIG_SYSTEMACE
3029 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
3031 When SystemACE support is added, the "ace" device type
3032 becomes available to the fat commands, i.e. fatls.
3034 - TFTP Fixed UDP Port:
3037 If this is defined, the environment variable tftpsrcp
3038 is used to supply the TFTP UDP source port value.
3039 If tftpsrcp isn't defined, the normal pseudo-random port
3040 number generator is used.
3042 Also, the environment variable tftpdstp is used to supply
3043 the TFTP UDP destination port value. If tftpdstp isn't
3044 defined, the normal port 69 is used.
3046 The purpose for tftpsrcp is to allow a TFTP server to
3047 blindly start the TFTP transfer using the pre-configured
3048 target IP address and UDP port. This has the effect of
3049 "punching through" the (Windows XP) firewall, allowing
3050 the remainder of the TFTP transfer to proceed normally.
3051 A better solution is to properly configure the firewall,
3052 but sometimes that is not allowed.
3057 This enables a generic 'hash' command which can produce
3058 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3062 Enable the hash verify command (hash -v). This adds to code
3065 CONFIG_SHA1 - This option enables support of hashing using SHA1
3066 algorithm. The hash is calculated in software.
3067 CONFIG_SHA256 - This option enables support of hashing using
3068 SHA256 algorithm. The hash is calculated in software.
3069 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3070 for SHA1/SHA256 hashing.
3071 This affects the 'hash' command and also the
3072 hash_lookup_algo() function.
3073 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3074 hardware-acceleration for SHA1/SHA256 progressive hashing.
3075 Data can be streamed in a block at a time and the hashing
3076 is performed in hardware.
3078 Note: There is also a sha1sum command, which should perhaps
3079 be deprecated in favour of 'hash sha1'.
3081 - Freescale i.MX specific commands:
3082 CONFIG_CMD_HDMIDETECT
3083 This enables 'hdmidet' command which returns true if an
3084 HDMI monitor is detected. This command is i.MX 6 specific.
3087 This enables the 'bmode' (bootmode) command for forcing
3088 a boot from specific media.
3090 This is useful for forcing the ROM's usb downloader to
3091 activate upon a watchdog reset which is nice when iterating
3092 on U-Boot. Using the reset button or running bmode normal
3093 will set it back to normal. This command currently
3094 supports i.MX53 and i.MX6.
3099 This enables the RSA algorithm used for FIT image verification
3100 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3102 The Modular Exponentiation algorithm in RSA is implemented using
3103 driver model. So CONFIG_DM needs to be enabled by default for this
3104 library to function.
3106 The signing part is build into mkimage regardless of this
3107 option. The software based modular exponentiation is built into
3108 mkimage irrespective of this option.
3110 - bootcount support:
3111 CONFIG_BOOTCOUNT_LIMIT
3113 This enables the bootcounter support, see:
3114 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3117 enable special bootcounter support on at91sam9xe based boards.
3119 enable special bootcounter support on blackfin based boards.
3121 enable special bootcounter support on da850 based boards.
3122 CONFIG_BOOTCOUNT_RAM
3123 enable support for the bootcounter in RAM
3124 CONFIG_BOOTCOUNT_I2C
3125 enable support for the bootcounter on an i2c (like RTC) device.
3126 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3127 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3129 CONFIG_BOOTCOUNT_ALEN = address len
3131 - Show boot progress:
3132 CONFIG_SHOW_BOOT_PROGRESS
3134 Defining this option allows to add some board-
3135 specific code (calling a user-provided function
3136 "show_boot_progress(int)") that enables you to show
3137 the system's boot progress on some display (for
3138 example, some LED's) on your board. At the moment,
3139 the following checkpoints are implemented:
3142 Legacy uImage format:
3145 1 common/cmd_bootm.c before attempting to boot an image
3146 -1 common/cmd_bootm.c Image header has bad magic number
3147 2 common/cmd_bootm.c Image header has correct magic number
3148 -2 common/cmd_bootm.c Image header has bad checksum
3149 3 common/cmd_bootm.c Image header has correct checksum
3150 -3 common/cmd_bootm.c Image data has bad checksum
3151 4 common/cmd_bootm.c Image data has correct checksum
3152 -4 common/cmd_bootm.c Image is for unsupported architecture
3153 5 common/cmd_bootm.c Architecture check OK
3154 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3155 6 common/cmd_bootm.c Image Type check OK
3156 -6 common/cmd_bootm.c gunzip uncompression error
3157 -7 common/cmd_bootm.c Unimplemented compression type
3158 7 common/cmd_bootm.c Uncompression OK
3159 8 common/cmd_bootm.c No uncompress/copy overwrite error
3160 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3162 9 common/image.c Start initial ramdisk verification
3163 -10 common/image.c Ramdisk header has bad magic number
3164 -11 common/image.c Ramdisk header has bad checksum
3165 10 common/image.c Ramdisk header is OK
3166 -12 common/image.c Ramdisk data has bad checksum
3167 11 common/image.c Ramdisk data has correct checksum
3168 12 common/image.c Ramdisk verification complete, start loading
3169 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3170 13 common/image.c Start multifile image verification
3171 14 common/image.c No initial ramdisk, no multifile, continue.
3173 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3175 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3176 -31 post/post.c POST test failed, detected by post_output_backlog()
3177 -32 post/post.c POST test failed, detected by post_run_single()
3179 34 common/cmd_doc.c before loading a Image from a DOC device
3180 -35 common/cmd_doc.c Bad usage of "doc" command
3181 35 common/cmd_doc.c correct usage of "doc" command
3182 -36 common/cmd_doc.c No boot device
3183 36 common/cmd_doc.c correct boot device
3184 -37 common/cmd_doc.c Unknown Chip ID on boot device
3185 37 common/cmd_doc.c correct chip ID found, device available
3186 -38 common/cmd_doc.c Read Error on boot device
3187 38 common/cmd_doc.c reading Image header from DOC device OK
3188 -39 common/cmd_doc.c Image header has bad magic number
3189 39 common/cmd_doc.c Image header has correct magic number
3190 -40 common/cmd_doc.c Error reading Image from DOC device
3191 40 common/cmd_doc.c Image header has correct magic number
3192 41 common/cmd_ide.c before loading a Image from a IDE device
3193 -42 common/cmd_ide.c Bad usage of "ide" command
3194 42 common/cmd_ide.c correct usage of "ide" command
3195 -43 common/cmd_ide.c No boot device
3196 43 common/cmd_ide.c boot device found
3197 -44 common/cmd_ide.c Device not available
3198 44 common/cmd_ide.c Device available
3199 -45 common/cmd_ide.c wrong partition selected
3200 45 common/cmd_ide.c partition selected
3201 -46 common/cmd_ide.c Unknown partition table
3202 46 common/cmd_ide.c valid partition table found
3203 -47 common/cmd_ide.c Invalid partition type
3204 47 common/cmd_ide.c correct partition type
3205 -48 common/cmd_ide.c Error reading Image Header on boot device
3206 48 common/cmd_ide.c reading Image Header from IDE device OK
3207 -49 common/cmd_ide.c Image header has bad magic number
3208 49 common/cmd_ide.c Image header has correct magic number
3209 -50 common/cmd_ide.c Image header has bad checksum
3210 50 common/cmd_ide.c Image header has correct checksum
3211 -51 common/cmd_ide.c Error reading Image from IDE device
3212 51 common/cmd_ide.c reading Image from IDE device OK
3213 52 common/cmd_nand.c before loading a Image from a NAND device
3214 -53 common/cmd_nand.c Bad usage of "nand" command
3215 53 common/cmd_nand.c correct usage of "nand" command
3216 -54 common/cmd_nand.c No boot device
3217 54 common/cmd_nand.c boot device found
3218 -55 common/cmd_nand.c Unknown Chip ID on boot device
3219 55 common/cmd_nand.c correct chip ID found, device available
3220 -56 common/cmd_nand.c Error reading Image Header on boot device
3221 56 common/cmd_nand.c reading Image Header from NAND device OK
3222 -57 common/cmd_nand.c Image header has bad magic number
3223 57 common/cmd_nand.c Image header has correct magic number
3224 -58 common/cmd_nand.c Error reading Image from NAND device
3225 58 common/cmd_nand.c reading Image from NAND device OK
3227 -60 common/env_common.c Environment has a bad CRC, using default
3229 64 net/eth.c starting with Ethernet configuration.
3230 -64 net/eth.c no Ethernet found.
3231 65 net/eth.c Ethernet found.
3233 -80 common/cmd_net.c usage wrong
3234 80 common/cmd_net.c before calling net_loop()
3235 -81 common/cmd_net.c some error in net_loop() occurred
3236 81 common/cmd_net.c net_loop() back without error
3237 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3238 82 common/cmd_net.c trying automatic boot
3239 83 common/cmd_net.c running "source" command
3240 -83 common/cmd_net.c some error in automatic boot or "source" command
3241 84 common/cmd_net.c end without errors
3246 100 common/cmd_bootm.c Kernel FIT Image has correct format
3247 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3248 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3249 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3250 102 common/cmd_bootm.c Kernel unit name specified
3251 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3252 103 common/cmd_bootm.c Found configuration node
3253 104 common/cmd_bootm.c Got kernel subimage node offset
3254 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3255 105 common/cmd_bootm.c Kernel subimage hash verification OK
3256 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3257 106 common/cmd_bootm.c Architecture check OK
3258 -106 common/cmd_bootm.c Kernel subimage has wrong type
3259 107 common/cmd_bootm.c Kernel subimage type OK
3260 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3261 108 common/cmd_bootm.c Got kernel subimage data/size
3262 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3263 -109 common/cmd_bootm.c Can't get kernel subimage type
3264 -110 common/cmd_bootm.c Can't get kernel subimage comp
3265 -111 common/cmd_bootm.c Can't get kernel subimage os
3266 -112 common/cmd_bootm.c Can't get kernel subimage load address
3267 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3269 120 common/image.c Start initial ramdisk verification
3270 -120 common/image.c Ramdisk FIT image has incorrect format
3271 121 common/image.c Ramdisk FIT image has correct format
3272 122 common/image.c No ramdisk subimage unit name, using configuration
3273 -122 common/image.c Can't get configuration for ramdisk subimage
3274 123 common/image.c Ramdisk unit name specified
3275 -124 common/image.c Can't get ramdisk subimage node offset
3276 125 common/image.c Got ramdisk subimage node offset
3277 -125 common/image.c Ramdisk subimage hash verification failed
3278 126 common/image.c Ramdisk subimage hash verification OK
3279 -126 common/image.c Ramdisk subimage for unsupported architecture
3280 127 common/image.c Architecture check OK
3281 -127 common/image.c Can't get ramdisk subimage data/size
3282 128 common/image.c Got ramdisk subimage data/size
3283 129 common/image.c Can't get ramdisk load address
3284 -129 common/image.c Got ramdisk load address
3286 -130 common/cmd_doc.c Incorrect FIT image format
3287 131 common/cmd_doc.c FIT image format OK
3289 -140 common/cmd_ide.c Incorrect FIT image format
3290 141 common/cmd_ide.c FIT image format OK
3292 -150 common/cmd_nand.c Incorrect FIT image format
3293 151 common/cmd_nand.c FIT image format OK
3295 - legacy image format:
3296 CONFIG_IMAGE_FORMAT_LEGACY
3297 enables the legacy image format support in U-Boot.
3300 enabled if CONFIG_FIT_SIGNATURE is not defined.
3302 CONFIG_DISABLE_IMAGE_LEGACY
3303 disable the legacy image format
3305 This define is introduced, as the legacy image format is
3306 enabled per default for backward compatibility.
3308 - FIT image support:
3310 Enable support for the FIT uImage format.
3312 CONFIG_FIT_BEST_MATCH
3313 When no configuration is explicitly selected, default to the
3314 one whose fdt's compatibility field best matches that of
3315 U-Boot itself. A match is considered "best" if it matches the
3316 most specific compatibility entry of U-Boot's fdt's root node.
3317 The order of entries in the configuration's fdt is ignored.
3319 CONFIG_FIT_SIGNATURE
3320 This option enables signature verification of FIT uImages,
3321 using a hash signed and verified using RSA. If
3322 CONFIG_SHA_PROG_HW_ACCEL is defined, i.e support for progressive
3323 hashing is available using hardware, RSA library will use it.
3324 See doc/uImage.FIT/signature.txt for more details.
3326 WARNING: When relying on signed FIT images with required
3327 signature check the legacy image format is default
3328 disabled. If a board need legacy image format support
3329 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3331 CONFIG_FIT_DISABLE_SHA256
3332 Supporting SHA256 hashes has quite an impact on binary size.
3333 For constrained systems sha256 hash support can be disabled
3336 - Standalone program support:
3337 CONFIG_STANDALONE_LOAD_ADDR
3339 This option defines a board specific value for the
3340 address where standalone program gets loaded, thus
3341 overwriting the architecture dependent default
3344 - Frame Buffer Address:
3347 Define CONFIG_FB_ADDR if you want to use specific
3348 address for frame buffer. This is typically the case
3349 when using a graphics controller has separate video
3350 memory. U-Boot will then place the frame buffer at
3351 the given address instead of dynamically reserving it
3352 in system RAM by calling lcd_setmem(), which grabs
3353 the memory for the frame buffer depending on the
3354 configured panel size.
3356 Please see board_init_f function.
3358 - Automatic software updates via TFTP server
3360 CONFIG_UPDATE_TFTP_CNT_MAX
3361 CONFIG_UPDATE_TFTP_MSEC_MAX
3363 These options enable and control the auto-update feature;
3364 for a more detailed description refer to doc/README.update.
3366 - MTD Support (mtdparts command, UBI support)
3369 Adds the MTD device infrastructure from the Linux kernel.
3370 Needed for mtdparts command support.
3372 CONFIG_MTD_PARTITIONS
3374 Adds the MTD partitioning infrastructure from the Linux
3375 kernel. Needed for UBI support.
3380 Adds commands for interacting with MTD partitions formatted
3381 with the UBI flash translation layer
3383 Requires also defining CONFIG_RBTREE
3385 CONFIG_UBI_SILENCE_MSG
3387 Make the verbose messages from UBI stop printing. This leaves
3388 warnings and errors enabled.
3391 CONFIG_MTD_UBI_WL_THRESHOLD
3392 This parameter defines the maximum difference between the highest
3393 erase counter value and the lowest erase counter value of eraseblocks
3394 of UBI devices. When this threshold is exceeded, UBI starts performing
3395 wear leveling by means of moving data from eraseblock with low erase
3396 counter to eraseblocks with high erase counter.
3398 The default value should be OK for SLC NAND flashes, NOR flashes and
3399 other flashes which have eraseblock life-cycle 100000 or more.
3400 However, in case of MLC NAND flashes which typically have eraseblock
3401 life-cycle less than 10000, the threshold should be lessened (e.g.,
3402 to 128 or 256, although it does not have to be power of 2).
3406 CONFIG_MTD_UBI_BEB_LIMIT
3407 This option specifies the maximum bad physical eraseblocks UBI
3408 expects on the MTD device (per 1024 eraseblocks). If the
3409 underlying flash does not admit of bad eraseblocks (e.g. NOR
3410 flash), this value is ignored.
3412 NAND datasheets often specify the minimum and maximum NVM
3413 (Number of Valid Blocks) for the flashes' endurance lifetime.
3414 The maximum expected bad eraseblocks per 1024 eraseblocks
3415 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3416 which gives 20 for most NANDs (MaxNVB is basically the total
3417 count of eraseblocks on the chip).
3419 To put it differently, if this value is 20, UBI will try to
3420 reserve about 1.9% of physical eraseblocks for bad blocks
3421 handling. And that will be 1.9% of eraseblocks on the entire
3422 NAND chip, not just the MTD partition UBI attaches. This means
3423 that if you have, say, a NAND flash chip admits maximum 40 bad
3424 eraseblocks, and it is split on two MTD partitions of the same
3425 size, UBI will reserve 40 eraseblocks when attaching a
3430 CONFIG_MTD_UBI_FASTMAP
3431 Fastmap is a mechanism which allows attaching an UBI device
3432 in nearly constant time. Instead of scanning the whole MTD device it
3433 only has to locate a checkpoint (called fastmap) on the device.
3434 The on-flash fastmap contains all information needed to attach
3435 the device. Using fastmap makes only sense on large devices where
3436 attaching by scanning takes long. UBI will not automatically install
3437 a fastmap on old images, but you can set the UBI parameter
3438 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3439 that fastmap-enabled images are still usable with UBI implementations
3440 without fastmap support. On typical flash devices the whole fastmap
3441 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3443 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3444 Set this parameter to enable fastmap automatically on images
3448 CONFIG_MTD_UBI_FM_DEBUG
3449 Enable UBI fastmap debug
3455 Adds commands for interacting with UBI volumes formatted as
3456 UBIFS. UBIFS is read-only in u-boot.
3458 Requires UBI support as well as CONFIG_LZO
3460 CONFIG_UBIFS_SILENCE_MSG
3462 Make the verbose messages from UBIFS stop printing. This leaves
3463 warnings and errors enabled.
3467 Enable building of SPL globally.
3470 LDSCRIPT for linking the SPL binary.
3472 CONFIG_SPL_MAX_FOOTPRINT
3473 Maximum size in memory allocated to the SPL, BSS included.
3474 When defined, the linker checks that the actual memory
3475 used by SPL from _start to __bss_end does not exceed it.
3476 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3477 must not be both defined at the same time.
3480 Maximum size of the SPL image (text, data, rodata, and
3481 linker lists sections), BSS excluded.
3482 When defined, the linker checks that the actual size does
3485 CONFIG_SPL_TEXT_BASE
3486 TEXT_BASE for linking the SPL binary.
3488 CONFIG_SPL_RELOC_TEXT_BASE
3489 Address to relocate to. If unspecified, this is equal to
3490 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3492 CONFIG_SPL_BSS_START_ADDR
3493 Link address for the BSS within the SPL binary.
3495 CONFIG_SPL_BSS_MAX_SIZE
3496 Maximum size in memory allocated to the SPL BSS.
3497 When defined, the linker checks that the actual memory used
3498 by SPL from __bss_start to __bss_end does not exceed it.
3499 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3500 must not be both defined at the same time.
3503 Adress of the start of the stack SPL will use
3505 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3506 When defined, SPL will panic() if the image it has
3507 loaded does not have a signature.
3508 Defining this is useful when code which loads images
3509 in SPL cannot guarantee that absolutely all read errors
3511 An example is the LPC32XX MLC NAND driver, which will
3512 consider that a completely unreadable NAND block is bad,
3513 and thus should be skipped silently.
3515 CONFIG_SPL_RELOC_STACK
3516 Adress of the start of the stack SPL will use after
3517 relocation. If unspecified, this is equal to
3520 CONFIG_SYS_SPL_MALLOC_START
3521 Starting address of the malloc pool used in SPL.
3522 When this option is set the full malloc is used in SPL and
3523 it is set up by spl_init() and before that, the simple malloc()
3524 can be used if CONFIG_SYS_MALLOC_F is defined.
3526 CONFIG_SYS_SPL_MALLOC_SIZE
3527 The size of the malloc pool used in SPL.
3529 CONFIG_SPL_FRAMEWORK
3530 Enable the SPL framework under common/. This framework
3531 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3532 NAND loading of the Linux Kernel.
3535 Enable booting directly to an OS from SPL.
3536 See also: doc/README.falcon
3538 CONFIG_SPL_DISPLAY_PRINT
3539 For ARM, enable an optional function to print more information
3540 about the running system.
3542 CONFIG_SPL_INIT_MINIMAL
3543 Arch init code should be built for a very small image
3545 CONFIG_SPL_LIBCOMMON_SUPPORT
3546 Support for common/libcommon.o in SPL binary
3548 CONFIG_SPL_LIBDISK_SUPPORT
3549 Support for disk/libdisk.o in SPL binary
3551 CONFIG_SPL_I2C_SUPPORT
3552 Support for drivers/i2c/libi2c.o in SPL binary
3554 CONFIG_SPL_GPIO_SUPPORT
3555 Support for drivers/gpio/libgpio.o in SPL binary
3557 CONFIG_SPL_MMC_SUPPORT
3558 Support for drivers/mmc/libmmc.o in SPL binary
3560 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3561 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3562 Address and partition on the MMC to load U-Boot from
3563 when the MMC is being used in raw mode.
3565 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3566 Partition on the MMC to load U-Boot from when the MMC is being
3569 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3570 Sector to load kernel uImage from when MMC is being
3571 used in raw mode (for Falcon mode)
3573 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3574 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3575 Sector and number of sectors to load kernel argument
3576 parameters from when MMC is being used in raw mode
3579 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3580 Partition on the MMC to load U-Boot from when the MMC is being
3583 CONFIG_SPL_FAT_SUPPORT
3584 Support for fs/fat/libfat.o in SPL binary
3586 CONFIG_SPL_EXT_SUPPORT
3587 Support for EXT filesystem in SPL binary
3589 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3590 Filename to read to load U-Boot when reading from filesystem
3592 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3593 Filename to read to load kernel uImage when reading
3594 from filesystem (for Falcon mode)
3596 CONFIG_SPL_FS_LOAD_ARGS_NAME
3597 Filename to read to load kernel argument parameters
3598 when reading from filesystem (for Falcon mode)
3600 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3601 Set this for NAND SPL on PPC mpc83xx targets, so that
3602 start.S waits for the rest of the SPL to load before
3603 continuing (the hardware starts execution after just
3604 loading the first page rather than the full 4K).
3606 CONFIG_SPL_SKIP_RELOCATE
3607 Avoid SPL relocation
3609 CONFIG_SPL_NAND_BASE
3610 Include nand_base.c in the SPL. Requires
3611 CONFIG_SPL_NAND_DRIVERS.
3613 CONFIG_SPL_NAND_DRIVERS
3614 SPL uses normal NAND drivers, not minimal drivers.
3617 Include standard software ECC in the SPL
3619 CONFIG_SPL_NAND_SIMPLE
3620 Support for NAND boot using simple NAND drivers that
3621 expose the cmd_ctrl() interface.
3623 CONFIG_SPL_MTD_SUPPORT
3624 Support for the MTD subsystem within SPL. Useful for
3625 environment on NAND support within SPL.
3627 CONFIG_SPL_NAND_RAW_ONLY
3628 Support to boot only raw u-boot.bin images. Use this only
3629 if you need to save space.
3631 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3632 Set for the SPL on PPC mpc8xxx targets, support for
3633 drivers/ddr/fsl/libddr.o in SPL binary.
3635 CONFIG_SPL_COMMON_INIT_DDR
3636 Set for common ddr init with serial presence detect in
3639 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3640 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3641 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3642 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3643 CONFIG_SYS_NAND_ECCBYTES
3644 Defines the size and behavior of the NAND that SPL uses
3647 CONFIG_SPL_NAND_BOOT
3648 Add support NAND boot
3650 CONFIG_SYS_NAND_U_BOOT_OFFS
3651 Location in NAND to read U-Boot from
3653 CONFIG_SYS_NAND_U_BOOT_DST
3654 Location in memory to load U-Boot to
3656 CONFIG_SYS_NAND_U_BOOT_SIZE
3657 Size of image to load
3659 CONFIG_SYS_NAND_U_BOOT_START
3660 Entry point in loaded image to jump to
3662 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3663 Define this if you need to first read the OOB and then the
3664 data. This is used, for example, on davinci platforms.
3666 CONFIG_SPL_OMAP3_ID_NAND
3667 Support for an OMAP3-specific set of functions to return the
3668 ID and MFR of the first attached NAND chip, if present.
3670 CONFIG_SPL_SERIAL_SUPPORT
3671 Support for drivers/serial/libserial.o in SPL binary
3673 CONFIG_SPL_SPI_FLASH_SUPPORT
3674 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3676 CONFIG_SPL_SPI_SUPPORT
3677 Support for drivers/spi/libspi.o in SPL binary
3679 CONFIG_SPL_RAM_DEVICE
3680 Support for running image already present in ram, in SPL binary
3682 CONFIG_SPL_LIBGENERIC_SUPPORT
3683 Support for lib/libgeneric.o in SPL binary
3685 CONFIG_SPL_ENV_SUPPORT
3686 Support for the environment operating in SPL binary
3688 CONFIG_SPL_NET_SUPPORT
3689 Support for the net/libnet.o in SPL binary.
3690 It conflicts with SPL env from storage medium specified by
3691 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3694 Image offset to which the SPL should be padded before appending
3695 the SPL payload. By default, this is defined as
3696 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3697 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3698 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3701 Final target image containing SPL and payload. Some SPLs
3702 use an arch-specific makefile fragment instead, for
3703 example if more than one image needs to be produced.
3705 CONFIG_FIT_SPL_PRINT
3706 Printing information about a FIT image adds quite a bit of
3707 code to SPL. So this is normally disabled in SPL. Use this
3708 option to re-enable it. This will affect the output of the
3709 bootm command when booting a FIT image.
3713 Enable building of TPL globally.
3716 Image offset to which the TPL should be padded before appending
3717 the TPL payload. By default, this is defined as
3718 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3719 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3720 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
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().
3736 Board initialization settings:
3737 ------------------------------
3739 During Initialization u-boot calls a number of board specific functions
3740 to allow the preparation of board specific prerequisites, e.g. pin setup
3741 before drivers are initialized. To enable these callbacks the
3742 following configuration macros have to be defined. Currently this is
3743 architecture specific, so please check arch/your_architecture/lib/board.c
3744 typically in board_init_f() and board_init_r().
3746 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3747 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3748 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3749 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3751 Configuration Settings:
3752 -----------------------
3754 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3755 Optionally it can be defined to support 64-bit memory commands.
3757 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3758 undefine this when you're short of memory.
3760 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3761 width of the commands listed in the 'help' command output.
3763 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3764 prompt for user input.
3766 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3768 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3770 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3772 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3773 the application (usually a Linux kernel) when it is
3776 - CONFIG_SYS_BAUDRATE_TABLE:
3777 List of legal baudrate settings for this board.
3779 - CONFIG_SYS_CONSOLE_INFO_QUIET
3780 Suppress display of console information at boot.
3782 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3783 If the board specific function
3784 extern int overwrite_console (void);
3785 returns 1, the stdin, stderr and stdout are switched to the
3786 serial port, else the settings in the environment are used.
3788 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3789 Enable the call to overwrite_console().
3791 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3792 Enable overwrite of previous console environment settings.
3794 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3795 Begin and End addresses of the area used by the
3798 - CONFIG_SYS_ALT_MEMTEST:
3799 Enable an alternate, more extensive memory test.
3801 - CONFIG_SYS_MEMTEST_SCRATCH:
3802 Scratch address used by the alternate memory test
3803 You only need to set this if address zero isn't writeable
3805 - CONFIG_SYS_MEM_RESERVE_SECURE
3806 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3807 is substracted from total RAM and won't be reported to OS.
3808 This memory can be used as secure memory. A variable
3809 gd->secure_ram is used to track the location. In systems
3810 the RAM base is not zero, or RAM is divided into banks,
3811 this variable needs to be recalcuated to get the address.
3813 - CONFIG_SYS_MEM_TOP_HIDE:
3814 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3815 this specified memory area will get subtracted from the top
3816 (end) of RAM and won't get "touched" at all by U-Boot. By
3817 fixing up gd->ram_size the Linux kernel should gets passed
3818 the now "corrected" memory size and won't touch it either.
3819 This should work for arch/ppc and arch/powerpc. Only Linux
3820 board ports in arch/powerpc with bootwrapper support that
3821 recalculate the memory size from the SDRAM controller setup
3822 will have to get fixed in Linux additionally.
3824 This option can be used as a workaround for the 440EPx/GRx
3825 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3828 WARNING: Please make sure that this value is a multiple of
3829 the Linux page size (normally 4k). If this is not the case,
3830 then the end address of the Linux memory will be located at a
3831 non page size aligned address and this could cause major
3834 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3835 Enable temporary baudrate change while serial download
3837 - CONFIG_SYS_SDRAM_BASE:
3838 Physical start address of SDRAM. _Must_ be 0 here.
3840 - CONFIG_SYS_MBIO_BASE:
3841 Physical start address of Motherboard I/O (if using a
3844 - CONFIG_SYS_FLASH_BASE:
3845 Physical start address of Flash memory.
3847 - CONFIG_SYS_MONITOR_BASE:
3848 Physical start address of boot monitor code (set by
3849 make config files to be same as the text base address
3850 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3851 CONFIG_SYS_FLASH_BASE when booting from flash.
3853 - CONFIG_SYS_MONITOR_LEN:
3854 Size of memory reserved for monitor code, used to
3855 determine _at_compile_time_ (!) if the environment is
3856 embedded within the U-Boot image, or in a separate
3859 - CONFIG_SYS_MALLOC_LEN:
3860 Size of DRAM reserved for malloc() use.
3862 - CONFIG_SYS_MALLOC_F_LEN
3863 Size of the malloc() pool for use before relocation. If
3864 this is defined, then a very simple malloc() implementation
3865 will become available before relocation. The address is just
3866 below the global data, and the stack is moved down to make
3869 This feature allocates regions with increasing addresses
3870 within the region. calloc() is supported, but realloc()
3871 is not available. free() is supported but does nothing.
3872 The memory will be freed (or in fact just forgotten) when
3873 U-Boot relocates itself.
3875 Pre-relocation malloc() is only supported on ARM and sandbox
3876 at present but is fairly easy to enable for other archs.
3878 - CONFIG_SYS_MALLOC_SIMPLE
3879 Provides a simple and small malloc() and calloc() for those
3880 boards which do not use the full malloc in SPL (which is
3881 enabled with CONFIG_SYS_SPL_MALLOC_START).
3883 - CONFIG_SYS_NONCACHED_MEMORY:
3884 Size of non-cached memory area. This area of memory will be
3885 typically located right below the malloc() area and mapped
3886 uncached in the MMU. This is useful for drivers that would
3887 otherwise require a lot of explicit cache maintenance. For
3888 some drivers it's also impossible to properly maintain the
3889 cache. For example if the regions that need to be flushed
3890 are not a multiple of the cache-line size, *and* padding
3891 cannot be allocated between the regions to align them (i.e.
3892 if the HW requires a contiguous array of regions, and the
3893 size of each region is not cache-aligned), then a flush of
3894 one region may result in overwriting data that hardware has
3895 written to another region in the same cache-line. This can
3896 happen for example in network drivers where descriptors for
3897 buffers are typically smaller than the CPU cache-line (e.g.
3898 16 bytes vs. 32 or 64 bytes).
3900 Non-cached memory is only supported on 32-bit ARM at present.
3902 - CONFIG_SYS_BOOTM_LEN:
3903 Normally compressed uImages are limited to an
3904 uncompressed size of 8 MBytes. If this is not enough,
3905 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3906 to adjust this setting to your needs.
3908 - CONFIG_SYS_BOOTMAPSZ:
3909 Maximum size of memory mapped by the startup code of
3910 the Linux kernel; all data that must be processed by
3911 the Linux kernel (bd_info, boot arguments, FDT blob if
3912 used) must be put below this limit, unless "bootm_low"
3913 environment variable is defined and non-zero. In such case
3914 all data for the Linux kernel must be between "bootm_low"
3915 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3916 variable "bootm_mapsize" will override the value of
3917 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3918 then the value in "bootm_size" will be used instead.
3920 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3921 Enable initrd_high functionality. If defined then the
3922 initrd_high feature is enabled and the bootm ramdisk subcommand
3925 - CONFIG_SYS_BOOT_GET_CMDLINE:
3926 Enables allocating and saving kernel cmdline in space between
3927 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3929 - CONFIG_SYS_BOOT_GET_KBD:
3930 Enables allocating and saving a kernel copy of the bd_info in
3931 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3933 - CONFIG_SYS_MAX_FLASH_BANKS:
3934 Max number of Flash memory banks
3936 - CONFIG_SYS_MAX_FLASH_SECT:
3937 Max number of sectors on a Flash chip
3939 - CONFIG_SYS_FLASH_ERASE_TOUT:
3940 Timeout for Flash erase operations (in ms)
3942 - CONFIG_SYS_FLASH_WRITE_TOUT:
3943 Timeout for Flash write operations (in ms)
3945 - CONFIG_SYS_FLASH_LOCK_TOUT
3946 Timeout for Flash set sector lock bit operation (in ms)
3948 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3949 Timeout for Flash clear lock bits operation (in ms)
3951 - CONFIG_SYS_FLASH_PROTECTION
3952 If defined, hardware flash sectors protection is used
3953 instead of U-Boot software protection.
3955 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3957 Enable TFTP transfers directly to flash memory;
3958 without this option such a download has to be
3959 performed in two steps: (1) download to RAM, and (2)
3960 copy from RAM to flash.
3962 The two-step approach is usually more reliable, since
3963 you can check if the download worked before you erase
3964 the flash, but in some situations (when system RAM is
3965 too limited to allow for a temporary copy of the
3966 downloaded image) this option may be very useful.
3968 - CONFIG_SYS_FLASH_CFI:
3969 Define if the flash driver uses extra elements in the
3970 common flash structure for storing flash geometry.
3972 - CONFIG_FLASH_CFI_DRIVER
3973 This option also enables the building of the cfi_flash driver
3974 in the drivers directory
3976 - CONFIG_FLASH_CFI_MTD
3977 This option enables the building of the cfi_mtd driver
3978 in the drivers directory. The driver exports CFI flash
3981 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3982 Use buffered writes to flash.
3984 - CONFIG_FLASH_SPANSION_S29WS_N
3985 s29ws-n MirrorBit flash has non-standard addresses for buffered
3988 - CONFIG_SYS_FLASH_QUIET_TEST
3989 If this option is defined, the common CFI flash doesn't
3990 print it's warning upon not recognized FLASH banks. This
3991 is useful, if some of the configured banks are only
3992 optionally available.
3994 - CONFIG_FLASH_SHOW_PROGRESS
3995 If defined (must be an integer), print out countdown
3996 digits and dots. Recommended value: 45 (9..1) for 80
3997 column displays, 15 (3..1) for 40 column displays.
3999 - CONFIG_FLASH_VERIFY
4000 If defined, the content of the flash (destination) is compared
4001 against the source after the write operation. An error message
4002 will be printed when the contents are not identical.
4003 Please note that this option is useless in nearly all cases,
4004 since such flash programming errors usually are detected earlier
4005 while unprotecting/erasing/programming. Please only enable
4006 this option if you really know what you are doing.
4008 - CONFIG_SYS_RX_ETH_BUFFER:
4009 Defines the number of Ethernet receive buffers. On some
4010 Ethernet controllers it is recommended to set this value
4011 to 8 or even higher (EEPRO100 or 405 EMAC), since all
4012 buffers can be full shortly after enabling the interface
4013 on high Ethernet traffic.
4014 Defaults to 4 if not defined.
4016 - CONFIG_ENV_MAX_ENTRIES
4018 Maximum number of entries in the hash table that is used
4019 internally to store the environment settings. The default
4020 setting is supposed to be generous and should work in most
4021 cases. This setting can be used to tune behaviour; see
4022 lib/hashtable.c for details.
4024 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4025 - CONFIG_ENV_FLAGS_LIST_STATIC
4026 Enable validation of the values given to environment variables when
4027 calling env set. Variables can be restricted to only decimal,
4028 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
4029 the variables can also be restricted to IP address or MAC address.
4031 The format of the list is:
4032 type_attribute = [s|d|x|b|i|m]
4033 access_attribute = [a|r|o|c]
4034 attributes = type_attribute[access_attribute]
4035 entry = variable_name[:attributes]
4038 The type attributes are:
4039 s - String (default)
4042 b - Boolean ([1yYtT|0nNfF])
4046 The access attributes are:
4052 - CONFIG_ENV_FLAGS_LIST_DEFAULT
4053 Define this to a list (string) to define the ".flags"
4054 environment variable in the default or embedded environment.
4056 - CONFIG_ENV_FLAGS_LIST_STATIC
4057 Define this to a list (string) to define validation that
4058 should be done if an entry is not found in the ".flags"
4059 environment variable. To override a setting in the static
4060 list, simply add an entry for the same variable name to the
4063 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4064 regular expression. This allows multiple variables to define the same
4065 flags without explicitly listing them for each variable.
4067 - CONFIG_ENV_ACCESS_IGNORE_FORCE
4068 If defined, don't allow the -f switch to env set override variable
4071 - CONFIG_SYS_GENERIC_BOARD
4072 This selects the architecture-generic board system instead of the
4073 architecture-specific board files. It is intended to move boards
4074 to this new framework over time. Defining this will disable the
4075 arch/foo/lib/board.c file and use common/board_f.c and
4076 common/board_r.c instead. To use this option your architecture
4077 must support it (i.e. must select HAVE_GENERIC_BOARD in arch/Kconfig).
4078 If you find problems enabling this option on your board please report
4079 the problem and send patches!
4081 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
4082 This is set by OMAP boards for the max time that reset should
4083 be asserted. See doc/README.omap-reset-time for details on how
4084 the value can be calculated on a given board.
4087 If stdint.h is available with your toolchain you can define this
4088 option to enable it. You can provide option 'USE_STDINT=1' when
4089 building U-Boot to enable this.
4091 The following definitions that deal with the placement and management
4092 of environment data (variable area); in general, we support the
4093 following configurations:
4095 - CONFIG_BUILD_ENVCRC:
4097 Builds up envcrc with the target environment so that external utils
4098 may easily extract it and embed it in final U-Boot images.
4100 - CONFIG_ENV_IS_IN_FLASH:
4102 Define this if the environment is in flash memory.
4104 a) The environment occupies one whole flash sector, which is
4105 "embedded" in the text segment with the U-Boot code. This
4106 happens usually with "bottom boot sector" or "top boot
4107 sector" type flash chips, which have several smaller
4108 sectors at the start or the end. For instance, such a
4109 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
4110 such a case you would place the environment in one of the
4111 4 kB sectors - with U-Boot code before and after it. With
4112 "top boot sector" type flash chips, you would put the
4113 environment in one of the last sectors, leaving a gap
4114 between U-Boot and the environment.
4116 - CONFIG_ENV_OFFSET:
4118 Offset of environment data (variable area) to the
4119 beginning of flash memory; for instance, with bottom boot
4120 type flash chips the second sector can be used: the offset
4121 for this sector is given here.
4123 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4127 This is just another way to specify the start address of
4128 the flash sector containing the environment (instead of
4131 - CONFIG_ENV_SECT_SIZE:
4133 Size of the sector containing the environment.
4136 b) Sometimes flash chips have few, equal sized, BIG sectors.
4137 In such a case you don't want to spend a whole sector for
4142 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4143 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4144 of this flash sector for the environment. This saves
4145 memory for the RAM copy of the environment.
4147 It may also save flash memory if you decide to use this
4148 when your environment is "embedded" within U-Boot code,
4149 since then the remainder of the flash sector could be used
4150 for U-Boot code. It should be pointed out that this is
4151 STRONGLY DISCOURAGED from a robustness point of view:
4152 updating the environment in flash makes it always
4153 necessary to erase the WHOLE sector. If something goes
4154 wrong before the contents has been restored from a copy in
4155 RAM, your target system will be dead.
4157 - CONFIG_ENV_ADDR_REDUND
4158 CONFIG_ENV_SIZE_REDUND
4160 These settings describe a second storage area used to hold
4161 a redundant copy of the environment data, so that there is
4162 a valid backup copy in case there is a power failure during
4163 a "saveenv" operation.
4165 BE CAREFUL! Any changes to the flash layout, and some changes to the
4166 source code will make it necessary to adapt <board>/u-boot.lds*
4170 - CONFIG_ENV_IS_IN_NVRAM:
4172 Define this if you have some non-volatile memory device
4173 (NVRAM, battery buffered SRAM) which you want to use for the
4179 These two #defines are used to determine the memory area you
4180 want to use for environment. It is assumed that this memory
4181 can just be read and written to, without any special
4184 BE CAREFUL! The first access to the environment happens quite early
4185 in U-Boot initialization (when we try to get the setting of for the
4186 console baudrate). You *MUST* have mapped your NVRAM area then, or
4189 Please note that even with NVRAM we still use a copy of the
4190 environment in RAM: we could work on NVRAM directly, but we want to
4191 keep settings there always unmodified except somebody uses "saveenv"
4192 to save the current settings.
4195 - CONFIG_ENV_IS_IN_EEPROM:
4197 Use this if you have an EEPROM or similar serial access
4198 device and a driver for it.
4200 - CONFIG_ENV_OFFSET:
4203 These two #defines specify the offset and size of the
4204 environment area within the total memory of your EEPROM.
4206 - CONFIG_SYS_I2C_EEPROM_ADDR:
4207 If defined, specified the chip address of the EEPROM device.
4208 The default address is zero.
4210 - CONFIG_SYS_I2C_EEPROM_BUS:
4211 If defined, specified the i2c bus of the EEPROM device.
4213 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4214 If defined, the number of bits used to address bytes in a
4215 single page in the EEPROM device. A 64 byte page, for example
4216 would require six bits.
4218 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4219 If defined, the number of milliseconds to delay between
4220 page writes. The default is zero milliseconds.
4222 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4223 The length in bytes of the EEPROM memory array address. Note
4224 that this is NOT the chip address length!
4226 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4227 EEPROM chips that implement "address overflow" are ones
4228 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4229 address and the extra bits end up in the "chip address" bit
4230 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4233 Note that we consider the length of the address field to
4234 still be one byte because the extra address bits are hidden
4235 in the chip address.
4237 - CONFIG_SYS_EEPROM_SIZE:
4238 The size in bytes of the EEPROM device.
4240 - CONFIG_ENV_EEPROM_IS_ON_I2C
4241 define this, if you have I2C and SPI activated, and your
4242 EEPROM, which holds the environment, is on the I2C bus.
4244 - CONFIG_I2C_ENV_EEPROM_BUS
4245 if you have an Environment on an EEPROM reached over
4246 I2C muxes, you can define here, how to reach this
4247 EEPROM. For example:
4249 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4251 EEPROM which holds the environment, is reached over
4252 a pca9547 i2c mux with address 0x70, channel 3.
4254 - CONFIG_ENV_IS_IN_DATAFLASH:
4256 Define this if you have a DataFlash memory device which you
4257 want to use for the environment.
4259 - CONFIG_ENV_OFFSET:
4263 These three #defines specify the offset and size of the
4264 environment area within the total memory of your DataFlash placed
4265 at the specified address.
4267 - CONFIG_ENV_IS_IN_SPI_FLASH:
4269 Define this if you have a SPI Flash memory device which you
4270 want to use for the environment.
4272 - CONFIG_ENV_OFFSET:
4275 These two #defines specify the offset and size of the
4276 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4277 aligned to an erase sector boundary.
4279 - CONFIG_ENV_SECT_SIZE:
4281 Define the SPI flash's sector size.
4283 - CONFIG_ENV_OFFSET_REDUND (optional):
4285 This setting describes a second storage area of CONFIG_ENV_SIZE
4286 size used to hold a redundant copy of the environment data, so
4287 that there is a valid backup copy in case there is a power failure
4288 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4289 aligned to an erase sector boundary.
4291 - CONFIG_ENV_SPI_BUS (optional):
4292 - CONFIG_ENV_SPI_CS (optional):
4294 Define the SPI bus and chip select. If not defined they will be 0.
4296 - CONFIG_ENV_SPI_MAX_HZ (optional):
4298 Define the SPI max work clock. If not defined then use 1MHz.
4300 - CONFIG_ENV_SPI_MODE (optional):
4302 Define the SPI work mode. If not defined then use SPI_MODE_3.
4304 - CONFIG_ENV_IS_IN_REMOTE:
4306 Define this if you have a remote memory space which you
4307 want to use for the local device's environment.
4312 These two #defines specify the address and size of the
4313 environment area within the remote memory space. The
4314 local device can get the environment from remote memory
4315 space by SRIO or PCIE links.
4317 BE CAREFUL! For some special cases, the local device can not use
4318 "saveenv" command. For example, the local device will get the
4319 environment stored in a remote NOR flash by SRIO or PCIE link,
4320 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4322 - CONFIG_ENV_IS_IN_NAND:
4324 Define this if you have a NAND device which you want to use
4325 for the environment.
4327 - CONFIG_ENV_OFFSET:
4330 These two #defines specify the offset and size of the environment
4331 area within the first NAND device. CONFIG_ENV_OFFSET must be
4332 aligned to an erase block boundary.
4334 - CONFIG_ENV_OFFSET_REDUND (optional):
4336 This setting describes a second storage area of CONFIG_ENV_SIZE
4337 size used to hold a redundant copy of the environment data, so
4338 that there is a valid backup copy in case there is a power failure
4339 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4340 aligned to an erase block boundary.
4342 - CONFIG_ENV_RANGE (optional):
4344 Specifies the length of the region in which the environment
4345 can be written. This should be a multiple of the NAND device's
4346 block size. Specifying a range with more erase blocks than
4347 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4348 the range to be avoided.
4350 - CONFIG_ENV_OFFSET_OOB (optional):
4352 Enables support for dynamically retrieving the offset of the
4353 environment from block zero's out-of-band data. The
4354 "nand env.oob" command can be used to record this offset.
4355 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4356 using CONFIG_ENV_OFFSET_OOB.
4358 - CONFIG_NAND_ENV_DST
4360 Defines address in RAM to which the nand_spl code should copy the
4361 environment. If redundant environment is used, it will be copied to
4362 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4364 - CONFIG_ENV_IS_IN_UBI:
4366 Define this if you have an UBI volume that you want to use for the
4367 environment. This has the benefit of wear-leveling the environment
4368 accesses, which is important on NAND.
4370 - CONFIG_ENV_UBI_PART:
4372 Define this to a string that is the mtd partition containing the UBI.
4374 - CONFIG_ENV_UBI_VOLUME:
4376 Define this to the name of the volume that you want to store the
4379 - CONFIG_ENV_UBI_VOLUME_REDUND:
4381 Define this to the name of another volume to store a second copy of
4382 the environment in. This will enable redundant environments in UBI.
4383 It is assumed that both volumes are in the same MTD partition.
4385 - CONFIG_UBI_SILENCE_MSG
4386 - CONFIG_UBIFS_SILENCE_MSG
4388 You will probably want to define these to avoid a really noisy system
4389 when storing the env in UBI.
4391 - CONFIG_ENV_IS_IN_FAT:
4392 Define this if you want to use the FAT file system for the environment.
4394 - FAT_ENV_INTERFACE:
4396 Define this to a string that is the name of the block device.
4398 - FAT_ENV_DEV_AND_PART:
4400 Define this to a string to specify the partition of the device. It can
4403 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4404 - "D:P": device D partition P. Error occurs if device D has no
4407 - "D" or "D:": device D partition 1 if device D has partition
4408 table, or the whole device D if has no partition
4410 - "D:auto": first partition in device D with bootable flag set.
4411 If none, first valid partition in device D. If no
4412 partition table then means device D.
4416 It's a string of the FAT file name. This file use to store the
4420 This should be defined. Otherwise it cannot save the environment file.
4422 - CONFIG_ENV_IS_IN_MMC:
4424 Define this if you have an MMC device which you want to use for the
4427 - CONFIG_SYS_MMC_ENV_DEV:
4429 Specifies which MMC device the environment is stored in.
4431 - CONFIG_SYS_MMC_ENV_PART (optional):
4433 Specifies which MMC partition the environment is stored in. If not
4434 set, defaults to partition 0, the user area. Common values might be
4435 1 (first MMC boot partition), 2 (second MMC boot partition).
4437 - CONFIG_ENV_OFFSET:
4440 These two #defines specify the offset and size of the environment
4441 area within the specified MMC device.
4443 If offset is positive (the usual case), it is treated as relative to
4444 the start of the MMC partition. If offset is negative, it is treated
4445 as relative to the end of the MMC partition. This can be useful if
4446 your board may be fitted with different MMC devices, which have
4447 different sizes for the MMC partitions, and you always want the
4448 environment placed at the very end of the partition, to leave the
4449 maximum possible space before it, to store other data.
4451 These two values are in units of bytes, but must be aligned to an
4452 MMC sector boundary.
4454 - CONFIG_ENV_OFFSET_REDUND (optional):
4456 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4457 hold a redundant copy of the environment data. This provides a
4458 valid backup copy in case the other copy is corrupted, e.g. due
4459 to a power failure during a "saveenv" operation.
4461 This value may also be positive or negative; this is handled in the
4462 same way as CONFIG_ENV_OFFSET.
4464 This value is also in units of bytes, but must also be aligned to
4465 an MMC sector boundary.
4467 - CONFIG_ENV_SIZE_REDUND (optional):
4469 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4470 set. If this value is set, it must be set to the same value as
4473 - CONFIG_SYS_SPI_INIT_OFFSET
4475 Defines offset to the initial SPI buffer area in DPRAM. The
4476 area is used at an early stage (ROM part) if the environment
4477 is configured to reside in the SPI EEPROM: We need a 520 byte
4478 scratch DPRAM area. It is used between the two initialization
4479 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4480 to be a good choice since it makes it far enough from the
4481 start of the data area as well as from the stack pointer.
4483 Please note that the environment is read-only until the monitor
4484 has been relocated to RAM and a RAM copy of the environment has been
4485 created; also, when using EEPROM you will have to use getenv_f()
4486 until then to read environment variables.
4488 The environment is protected by a CRC32 checksum. Before the monitor
4489 is relocated into RAM, as a result of a bad CRC you will be working
4490 with the compiled-in default environment - *silently*!!! [This is
4491 necessary, because the first environment variable we need is the
4492 "baudrate" setting for the console - if we have a bad CRC, we don't
4493 have any device yet where we could complain.]
4495 Note: once the monitor has been relocated, then it will complain if
4496 the default environment is used; a new CRC is computed as soon as you
4497 use the "saveenv" command to store a valid environment.
4499 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4500 Echo the inverted Ethernet link state to the fault LED.
4502 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4503 also needs to be defined.
4505 - CONFIG_SYS_FAULT_MII_ADDR:
4506 MII address of the PHY to check for the Ethernet link state.
4508 - CONFIG_NS16550_MIN_FUNCTIONS:
4509 Define this if you desire to only have use of the NS16550_init
4510 and NS16550_putc functions for the serial driver located at
4511 drivers/serial/ns16550.c. This option is useful for saving
4512 space for already greatly restricted images, including but not
4513 limited to NAND_SPL configurations.
4515 - CONFIG_DISPLAY_BOARDINFO
4516 Display information about the board that U-Boot is running on
4517 when U-Boot starts up. The board function checkboard() is called
4520 - CONFIG_DISPLAY_BOARDINFO_LATE
4521 Similar to the previous option, but display this information
4522 later, once stdio is running and output goes to the LCD, if
4525 - CONFIG_BOARD_SIZE_LIMIT:
4526 Maximum size of the U-Boot image. When defined, the
4527 build system checks that the actual size does not
4530 Low Level (hardware related) configuration options:
4531 ---------------------------------------------------
4533 - CONFIG_SYS_CACHELINE_SIZE:
4534 Cache Line Size of the CPU.
4536 - CONFIG_SYS_DEFAULT_IMMR:
4537 Default address of the IMMR after system reset.
4539 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4540 and RPXsuper) to be able to adjust the position of
4541 the IMMR register after a reset.
4543 - CONFIG_SYS_CCSRBAR_DEFAULT:
4544 Default (power-on reset) physical address of CCSR on Freescale
4547 - CONFIG_SYS_CCSRBAR:
4548 Virtual address of CCSR. On a 32-bit build, this is typically
4549 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4551 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4552 for cross-platform code that uses that macro instead.
4554 - CONFIG_SYS_CCSRBAR_PHYS:
4555 Physical address of CCSR. CCSR can be relocated to a new
4556 physical address, if desired. In this case, this macro should
4557 be set to that address. Otherwise, it should be set to the
4558 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4559 is typically relocated on 36-bit builds. It is recommended
4560 that this macro be defined via the _HIGH and _LOW macros:
4562 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4563 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4565 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4566 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4567 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4568 used in assembly code, so it must not contain typecasts or
4569 integer size suffixes (e.g. "ULL").
4571 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4572 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4573 used in assembly code, so it must not contain typecasts or
4574 integer size suffixes (e.g. "ULL").
4576 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4577 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4578 forced to a value that ensures that CCSR is not relocated.
4580 - Floppy Disk Support:
4581 CONFIG_SYS_FDC_DRIVE_NUMBER
4583 the default drive number (default value 0)
4585 CONFIG_SYS_ISA_IO_STRIDE
4587 defines the spacing between FDC chipset registers
4590 CONFIG_SYS_ISA_IO_OFFSET
4592 defines the offset of register from address. It
4593 depends on which part of the data bus is connected to
4594 the FDC chipset. (default value 0)
4596 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4597 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4600 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4601 fdc_hw_init() is called at the beginning of the FDC
4602 setup. fdc_hw_init() must be provided by the board
4603 source code. It is used to make hardware-dependent
4607 Most IDE controllers were designed to be connected with PCI
4608 interface. Only few of them were designed for AHB interface.
4609 When software is doing ATA command and data transfer to
4610 IDE devices through IDE-AHB controller, some additional
4611 registers accessing to these kind of IDE-AHB controller
4614 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4615 DO NOT CHANGE unless you know exactly what you're
4616 doing! (11-4) [MPC8xx/82xx systems only]
4618 - CONFIG_SYS_INIT_RAM_ADDR:
4620 Start address of memory area that can be used for
4621 initial data and stack; please note that this must be
4622 writable memory that is working WITHOUT special
4623 initialization, i. e. you CANNOT use normal RAM which
4624 will become available only after programming the
4625 memory controller and running certain initialization
4628 U-Boot uses the following memory types:
4629 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4630 - MPC824X: data cache
4631 - PPC4xx: data cache
4633 - CONFIG_SYS_GBL_DATA_OFFSET:
4635 Offset of the initial data structure in the memory
4636 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4637 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4638 data is located at the end of the available space
4639 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4640 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4641 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4642 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4645 On the MPC824X (or other systems that use the data
4646 cache for initial memory) the address chosen for
4647 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4648 point to an otherwise UNUSED address space between
4649 the top of RAM and the start of the PCI space.
4651 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4653 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4655 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4657 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4659 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4661 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4663 - CONFIG_SYS_OR_TIMING_SDRAM:
4666 - CONFIG_SYS_MAMR_PTA:
4667 periodic timer for refresh
4669 - CONFIG_SYS_DER: Debug Event Register (37-47)
4671 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4672 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4673 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4674 CONFIG_SYS_BR1_PRELIM:
4675 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4677 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4678 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4679 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4680 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4682 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4683 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4684 Machine Mode Register and Memory Periodic Timer
4685 Prescaler definitions (SDRAM timing)
4687 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4688 enable I2C microcode relocation patch (MPC8xx);
4689 define relocation offset in DPRAM [DSP2]
4691 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4692 enable SMC microcode relocation patch (MPC8xx);
4693 define relocation offset in DPRAM [SMC1]
4695 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4696 enable SPI microcode relocation patch (MPC8xx);
4697 define relocation offset in DPRAM [SCC4]
4699 - CONFIG_SYS_USE_OSCCLK:
4700 Use OSCM clock mode on MBX8xx board. Be careful,
4701 wrong setting might damage your board. Read
4702 doc/README.MBX before setting this variable!
4704 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4705 Offset of the bootmode word in DPRAM used by post
4706 (Power On Self Tests). This definition overrides
4707 #define'd default value in commproc.h resp.
4710 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4711 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4712 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4713 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4714 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4715 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4716 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4717 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4718 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4720 - CONFIG_PCI_DISABLE_PCIE:
4721 Disable PCI-Express on systems where it is supported but not
4724 - CONFIG_PCI_ENUM_ONLY
4725 Only scan through and get the devices on the buses.
4726 Don't do any setup work, presumably because someone or
4727 something has already done it, and we don't need to do it
4728 a second time. Useful for platforms that are pre-booted
4729 by coreboot or similar.
4731 - CONFIG_PCI_INDIRECT_BRIDGE:
4732 Enable support for indirect PCI bridges.
4735 Chip has SRIO or not
4738 Board has SRIO 1 port available
4741 Board has SRIO 2 port available
4743 - CONFIG_SRIO_PCIE_BOOT_MASTER
4744 Board can support master function for Boot from SRIO and PCIE
4746 - CONFIG_SYS_SRIOn_MEM_VIRT:
4747 Virtual Address of SRIO port 'n' memory region
4749 - CONFIG_SYS_SRIOn_MEM_PHYS:
4750 Physical Address of SRIO port 'n' memory region
4752 - CONFIG_SYS_SRIOn_MEM_SIZE:
4753 Size of SRIO port 'n' memory region
4755 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4756 Defined to tell the NAND controller that the NAND chip is using
4758 Not all NAND drivers use this symbol.
4759 Example of drivers that use it:
4760 - drivers/mtd/nand/ndfc.c
4761 - drivers/mtd/nand/mxc_nand.c
4763 - CONFIG_SYS_NDFC_EBC0_CFG
4764 Sets the EBC0_CFG register for the NDFC. If not defined
4765 a default value will be used.
4768 Get DDR timing information from an I2C EEPROM. Common
4769 with pluggable memory modules such as SODIMMs
4772 I2C address of the SPD EEPROM
4774 - CONFIG_SYS_SPD_BUS_NUM
4775 If SPD EEPROM is on an I2C bus other than the first
4776 one, specify here. Note that the value must resolve
4777 to something your driver can deal with.
4779 - CONFIG_SYS_DDR_RAW_TIMING
4780 Get DDR timing information from other than SPD. Common with
4781 soldered DDR chips onboard without SPD. DDR raw timing
4782 parameters are extracted from datasheet and hard-coded into
4783 header files or board specific files.
4785 - CONFIG_FSL_DDR_INTERACTIVE
4786 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4788 - CONFIG_FSL_DDR_SYNC_REFRESH
4789 Enable sync of refresh for multiple controllers.
4791 - CONFIG_FSL_DDR_BIST
4792 Enable built-in memory test for Freescale DDR controllers.
4794 - CONFIG_SYS_83XX_DDR_USES_CS0
4795 Only for 83xx systems. If specified, then DDR should
4796 be configured using CS0 and CS1 instead of CS2 and CS3.
4798 - CONFIG_ETHER_ON_FEC[12]
4799 Define to enable FEC[12] on a 8xx series processor.
4801 - CONFIG_FEC[12]_PHY
4802 Define to the hardcoded PHY address which corresponds
4803 to the given FEC; i. e.
4804 #define CONFIG_FEC1_PHY 4
4805 means that the PHY with address 4 is connected to FEC1
4807 When set to -1, means to probe for first available.
4809 - CONFIG_FEC[12]_PHY_NORXERR
4810 The PHY does not have a RXERR line (RMII only).
4811 (so program the FEC to ignore it).
4814 Enable RMII mode for all FECs.
4815 Note that this is a global option, we can't
4816 have one FEC in standard MII mode and another in RMII mode.
4818 - CONFIG_CRC32_VERIFY
4819 Add a verify option to the crc32 command.
4822 => crc32 -v <address> <count> <crc32>
4824 Where address/count indicate a memory area
4825 and crc32 is the correct crc32 which the
4829 Add the "loopw" memory command. This only takes effect if
4830 the memory commands are activated globally (CONFIG_CMD_MEM).
4833 Add the "mdc" and "mwc" memory commands. These are cyclic
4838 This command will print 4 bytes (10,11,12,13) each 500 ms.
4840 => mwc.l 100 12345678 10
4841 This command will write 12345678 to address 100 all 10 ms.
4843 This only takes effect if the memory commands are activated
4844 globally (CONFIG_CMD_MEM).
4846 - CONFIG_SKIP_LOWLEVEL_INIT
4847 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4848 low level initializations (like setting up the memory
4849 controller) are omitted and/or U-Boot does not
4850 relocate itself into RAM.
4852 Normally this variable MUST NOT be defined. The only
4853 exception is when U-Boot is loaded (to RAM) by some
4854 other boot loader or by a debugger which performs
4855 these initializations itself.
4858 Modifies the behaviour of start.S when compiling a loader
4859 that is executed before the actual U-Boot. E.g. when
4860 compiling a NAND SPL.
4863 Modifies the behaviour of start.S when compiling a loader
4864 that is executed after the SPL and before the actual U-Boot.
4865 It is loaded by the SPL.
4867 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4868 Only for 85xx systems. If this variable is specified, the section
4869 .resetvec is not kept and the section .bootpg is placed in the
4870 previous 4k of the .text section.
4872 - CONFIG_ARCH_MAP_SYSMEM
4873 Generally U-Boot (and in particular the md command) uses
4874 effective address. It is therefore not necessary to regard
4875 U-Boot address as virtual addresses that need to be translated
4876 to physical addresses. However, sandbox requires this, since
4877 it maintains its own little RAM buffer which contains all
4878 addressable memory. This option causes some memory accesses
4879 to be mapped through map_sysmem() / unmap_sysmem().
4881 - CONFIG_USE_ARCH_MEMCPY
4882 CONFIG_USE_ARCH_MEMSET
4883 If these options are used a optimized version of memcpy/memset will
4884 be used if available. These functions may be faster under some
4885 conditions but may increase the binary size.
4887 - CONFIG_X86_RESET_VECTOR
4888 If defined, the x86 reset vector code is included. This is not
4889 needed when U-Boot is running from Coreboot.
4892 Defines the MPU clock speed (in MHz).
4894 NOTE : currently only supported on AM335x platforms.
4896 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4897 Enables the RTC32K OSC on AM33xx based plattforms
4899 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4900 Option to disable subpage write in NAND driver
4901 driver that uses this:
4902 drivers/mtd/nand/davinci_nand.c
4904 Freescale QE/FMAN Firmware Support:
4905 -----------------------------------
4907 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4908 loading of "firmware", which is encoded in the QE firmware binary format.
4909 This firmware often needs to be loaded during U-Boot booting, so macros
4910 are used to identify the storage device (NOR flash, SPI, etc) and the address
4913 - CONFIG_SYS_FMAN_FW_ADDR
4914 The address in the storage device where the FMAN microcode is located. The
4915 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4918 - CONFIG_SYS_QE_FW_ADDR
4919 The address in the storage device where the QE microcode is located. The
4920 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4923 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4924 The maximum possible size of the firmware. The firmware binary format
4925 has a field that specifies the actual size of the firmware, but it
4926 might not be possible to read any part of the firmware unless some
4927 local storage is allocated to hold the entire firmware first.
4929 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4930 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4931 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4932 virtual address in NOR flash.
4934 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4935 Specifies that QE/FMAN firmware is located in NAND flash.
4936 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4938 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4939 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4940 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4942 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4943 Specifies that QE/FMAN firmware is located on the primary SPI
4944 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4946 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4947 Specifies that QE/FMAN firmware is located in the remote (master)
4948 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4949 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4950 window->master inbound window->master LAW->the ucode address in
4951 master's memory space.
4953 Freescale Layerscape Management Complex Firmware Support:
4954 ---------------------------------------------------------
4955 The Freescale Layerscape Management Complex (MC) supports the loading of
4957 This firmware often needs to be loaded during U-Boot booting, so macros
4958 are used to identify the storage device (NOR flash, SPI, etc) and the address
4961 - CONFIG_FSL_MC_ENET
4962 Enable the MC driver for Layerscape SoCs.
4964 - CONFIG_SYS_LS_MC_FW_ADDR
4965 The address in the storage device where the firmware is located. The
4966 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4969 - CONFIG_SYS_LS_MC_FW_LENGTH
4970 The maximum possible size of the firmware. The firmware binary format
4971 has a field that specifies the actual size of the firmware, but it
4972 might not be possible to read any part of the firmware unless some
4973 local storage is allocated to hold the entire firmware first.
4975 - CONFIG_SYS_LS_MC_FW_IN_NOR
4976 Specifies that MC firmware is located in NOR flash, mapped as
4977 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4978 virtual address in NOR flash.
4980 Freescale Layerscape Debug Server Support:
4981 -------------------------------------------
4982 The Freescale Layerscape Debug Server Support supports the loading of
4983 "Debug Server firmware" and triggering SP boot-rom.
4984 This firmware often needs to be loaded during U-Boot booting.
4986 - CONFIG_FSL_DEBUG_SERVER
4987 Enable the Debug Server for Layerscape SoCs.
4989 - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
4990 Define minimum DDR size required for debug server image
4992 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4993 Define alignment of reserved memory MC requires
4998 In order to achieve reproducible builds, timestamps used in the U-Boot build
4999 process have to be set to a fixed value.
5001 This is done using the SOURCE_DATE_EPOCH environment variable.
5002 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
5003 option for U-Boot or an environment variable in U-Boot.
5005 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
5007 Building the Software:
5008 ======================
5010 Building U-Boot has been tested in several native build environments
5011 and in many different cross environments. Of course we cannot support
5012 all possibly existing versions of cross development tools in all
5013 (potentially obsolete) versions. In case of tool chain problems we
5014 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
5015 which is extensively used to build and test U-Boot.
5017 If you are not using a native environment, it is assumed that you
5018 have GNU cross compiling tools available in your path. In this case,
5019 you must set the environment variable CROSS_COMPILE in your shell.
5020 Note that no changes to the Makefile or any other source files are
5021 necessary. For example using the ELDK on a 4xx CPU, please enter:
5023 $ CROSS_COMPILE=ppc_4xx-
5024 $ export CROSS_COMPILE
5026 Note: If you wish to generate Windows versions of the utilities in
5027 the tools directory you can use the MinGW toolchain
5028 (http://www.mingw.org). Set your HOST tools to the MinGW
5029 toolchain and execute 'make tools'. For example:
5031 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
5033 Binaries such as tools/mkimage.exe will be created which can
5034 be executed on computers running Windows.
5036 U-Boot is intended to be simple to build. After installing the
5037 sources you must configure U-Boot for one specific board type. This
5042 where "NAME_defconfig" is the name of one of the existing configu-
5043 rations; see boards.cfg for supported names.
5045 Note: for some board special configuration names may exist; check if
5046 additional information is available from the board vendor; for
5047 instance, the TQM823L systems are available without (standard)
5048 or with LCD support. You can select such additional "features"
5049 when choosing the configuration, i. e.
5051 make TQM823L_defconfig
5052 - will configure for a plain TQM823L, i. e. no LCD support
5054 make TQM823L_LCD_defconfig
5055 - will configure for a TQM823L with U-Boot console on LCD
5060 Finally, type "make all", and you should get some working U-Boot
5061 images ready for download to / installation on your system:
5063 - "u-boot.bin" is a raw binary image
5064 - "u-boot" is an image in ELF binary format
5065 - "u-boot.srec" is in Motorola S-Record format
5067 By default the build is performed locally and the objects are saved
5068 in the source directory. One of the two methods can be used to change
5069 this behavior and build U-Boot to some external directory:
5071 1. Add O= to the make command line invocations:
5073 make O=/tmp/build distclean
5074 make O=/tmp/build NAME_defconfig
5075 make O=/tmp/build all
5077 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
5079 export KBUILD_OUTPUT=/tmp/build
5084 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
5088 Please be aware that the Makefiles assume you are using GNU make, so
5089 for instance on NetBSD you might need to use "gmake" instead of
5093 If the system board that you have is not listed, then you will need
5094 to port U-Boot to your hardware platform. To do this, follow these
5097 1. Create a new directory to hold your board specific code. Add any
5098 files you need. In your board directory, you will need at least
5099 the "Makefile" and a "<board>.c".
5100 2. Create a new configuration file "include/configs/<board>.h" for
5102 3. If you're porting U-Boot to a new CPU, then also create a new
5103 directory to hold your CPU specific code. Add any files you need.
5104 4. Run "make <board>_defconfig" with your new name.
5105 5. Type "make", and you should get a working "u-boot.srec" file
5106 to be installed on your target system.
5107 6. Debug and solve any problems that might arise.
5108 [Of course, this last step is much harder than it sounds.]
5111 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
5112 ==============================================================
5114 If you have modified U-Boot sources (for instance added a new board
5115 or support for new devices, a new CPU, etc.) you are expected to
5116 provide feedback to the other developers. The feedback normally takes
5117 the form of a "patch", i. e. a context diff against a certain (latest
5118 official or latest in the git repository) version of U-Boot sources.
5120 But before you submit such a patch, please verify that your modifi-
5121 cation did not break existing code. At least make sure that *ALL* of
5122 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5123 just run the "MAKEALL" script, which will configure and build U-Boot
5124 for ALL supported system. Be warned, this will take a while. You can
5125 select which (cross) compiler to use by passing a `CROSS_COMPILE'
5126 environment variable to the script, i. e. to use the ELDK cross tools
5129 CROSS_COMPILE=ppc_8xx- MAKEALL
5131 or to build on a native PowerPC system you can type
5133 CROSS_COMPILE=' ' MAKEALL
5135 When using the MAKEALL script, the default behaviour is to build
5136 U-Boot in the source directory. This location can be changed by
5137 setting the BUILD_DIR environment variable. Also, for each target
5138 built, the MAKEALL script saves two log files (<target>.ERR and
5139 <target>.MAKEALL) in the <source dir>/LOG directory. This default
5140 location can be changed by setting the MAKEALL_LOGDIR environment
5141 variable. For example:
5143 export BUILD_DIR=/tmp/build
5144 export MAKEALL_LOGDIR=/tmp/log
5145 CROSS_COMPILE=ppc_8xx- MAKEALL
5147 With the above settings build objects are saved in the /tmp/build,
5148 log files are saved in the /tmp/log and the source tree remains clean
5149 during the whole build process.
5152 See also "U-Boot Porting Guide" below.
5155 Monitor Commands - Overview:
5156 ============================
5158 go - start application at address 'addr'
5159 run - run commands in an environment variable
5160 bootm - boot application image from memory
5161 bootp - boot image via network using BootP/TFTP protocol
5162 bootz - boot zImage from memory
5163 tftpboot- boot image via network using TFTP protocol
5164 and env variables "ipaddr" and "serverip"
5165 (and eventually "gatewayip")
5166 tftpput - upload a file via network using TFTP protocol
5167 rarpboot- boot image via network using RARP/TFTP protocol
5168 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5169 loads - load S-Record file over serial line
5170 loadb - load binary file over serial line (kermit mode)
5172 mm - memory modify (auto-incrementing)
5173 nm - memory modify (constant address)
5174 mw - memory write (fill)
5176 cmp - memory compare
5177 crc32 - checksum calculation
5178 i2c - I2C sub-system
5179 sspi - SPI utility commands
5180 base - print or set address offset
5181 printenv- print environment variables
5182 setenv - set environment variables
5183 saveenv - save environment variables to persistent storage
5184 protect - enable or disable FLASH write protection
5185 erase - erase FLASH memory
5186 flinfo - print FLASH memory information
5187 nand - NAND memory operations (see doc/README.nand)
5188 bdinfo - print Board Info structure
5189 iminfo - print header information for application image
5190 coninfo - print console devices and informations
5191 ide - IDE sub-system
5192 loop - infinite loop on address range
5193 loopw - infinite write loop on address range
5194 mtest - simple RAM test
5195 icache - enable or disable instruction cache
5196 dcache - enable or disable data cache
5197 reset - Perform RESET of the CPU
5198 echo - echo args to console
5199 version - print monitor version
5200 help - print online help
5201 ? - alias for 'help'
5204 Monitor Commands - Detailed Description:
5205 ========================================
5209 For now: just type "help <command>".
5212 Environment Variables:
5213 ======================
5215 U-Boot supports user configuration using Environment Variables which
5216 can be made persistent by saving to Flash memory.
5218 Environment Variables are set using "setenv", printed using
5219 "printenv", and saved to Flash using "saveenv". Using "setenv"
5220 without a value can be used to delete a variable from the
5221 environment. As long as you don't save the environment you are
5222 working with an in-memory copy. In case the Flash area containing the
5223 environment is erased by accident, a default environment is provided.
5225 Some configuration options can be set using Environment Variables.
5227 List of environment variables (most likely not complete):
5229 baudrate - see CONFIG_BAUDRATE
5231 bootdelay - see CONFIG_BOOTDELAY
5233 bootcmd - see CONFIG_BOOTCOMMAND
5235 bootargs - Boot arguments when booting an RTOS image
5237 bootfile - Name of the image to load with TFTP
5239 bootm_low - Memory range available for image processing in the bootm
5240 command can be restricted. This variable is given as
5241 a hexadecimal number and defines lowest address allowed
5242 for use by the bootm command. See also "bootm_size"
5243 environment variable. Address defined by "bootm_low" is
5244 also the base of the initial memory mapping for the Linux
5245 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5248 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5249 This variable is given as a hexadecimal number and it
5250 defines the size of the memory region starting at base
5251 address bootm_low that is accessible by the Linux kernel
5252 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5253 as the default value if it is defined, and bootm_size is
5256 bootm_size - Memory range available for image processing in the bootm
5257 command can be restricted. This variable is given as
5258 a hexadecimal number and defines the size of the region
5259 allowed for use by the bootm command. See also "bootm_low"
5260 environment variable.
5262 updatefile - Location of the software update file on a TFTP server, used
5263 by the automatic software update feature. Please refer to
5264 documentation in doc/README.update for more details.
5266 autoload - if set to "no" (any string beginning with 'n'),
5267 "bootp" will just load perform a lookup of the
5268 configuration from the BOOTP server, but not try to
5269 load any image using TFTP
5271 autostart - if set to "yes", an image loaded using the "bootp",
5272 "rarpboot", "tftpboot" or "diskboot" commands will
5273 be automatically started (by internally calling
5276 If set to "no", a standalone image passed to the
5277 "bootm" command will be copied to the load address
5278 (and eventually uncompressed), but NOT be started.
5279 This can be used to load and uncompress arbitrary
5282 fdt_high - if set this restricts the maximum address that the
5283 flattened device tree will be copied into upon boot.
5284 For example, if you have a system with 1 GB memory
5285 at physical address 0x10000000, while Linux kernel
5286 only recognizes the first 704 MB as low memory, you
5287 may need to set fdt_high as 0x3C000000 to have the
5288 device tree blob be copied to the maximum address
5289 of the 704 MB low memory, so that Linux kernel can
5290 access it during the boot procedure.
5292 If this is set to the special value 0xFFFFFFFF then
5293 the fdt will not be copied at all on boot. For this
5294 to work it must reside in writable memory, have
5295 sufficient padding on the end of it for u-boot to
5296 add the information it needs into it, and the memory
5297 must be accessible by the kernel.
5299 fdtcontroladdr- if set this is the address of the control flattened
5300 device tree used by U-Boot when CONFIG_OF_CONTROL is
5303 i2cfast - (PPC405GP|PPC405EP only)
5304 if set to 'y' configures Linux I2C driver for fast
5305 mode (400kHZ). This environment variable is used in
5306 initialization code. So, for changes to be effective
5307 it must be saved and board must be reset.
5309 initrd_high - restrict positioning of initrd images:
5310 If this variable is not set, initrd images will be
5311 copied to the highest possible address in RAM; this
5312 is usually what you want since it allows for
5313 maximum initrd size. If for some reason you want to
5314 make sure that the initrd image is loaded below the
5315 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5316 variable to a value of "no" or "off" or "0".
5317 Alternatively, you can set it to a maximum upper
5318 address to use (U-Boot will still check that it
5319 does not overwrite the U-Boot stack and data).
5321 For instance, when you have a system with 16 MB
5322 RAM, and want to reserve 4 MB from use by Linux,
5323 you can do this by adding "mem=12M" to the value of
5324 the "bootargs" variable. However, now you must make
5325 sure that the initrd image is placed in the first
5326 12 MB as well - this can be done with
5328 setenv initrd_high 00c00000
5330 If you set initrd_high to 0xFFFFFFFF, this is an
5331 indication to U-Boot that all addresses are legal
5332 for the Linux kernel, including addresses in flash
5333 memory. In this case U-Boot will NOT COPY the
5334 ramdisk at all. This may be useful to reduce the
5335 boot time on your system, but requires that this
5336 feature is supported by your Linux kernel.
5338 ipaddr - IP address; needed for tftpboot command
5340 loadaddr - Default load address for commands like "bootp",
5341 "rarpboot", "tftpboot", "loadb" or "diskboot"
5343 loads_echo - see CONFIG_LOADS_ECHO
5345 serverip - TFTP server IP address; needed for tftpboot command
5347 bootretry - see CONFIG_BOOT_RETRY_TIME
5349 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5351 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5353 ethprime - controls which interface is used first.
5355 ethact - controls which interface is currently active.
5356 For example you can do the following
5358 => setenv ethact FEC
5359 => ping 192.168.0.1 # traffic sent on FEC
5360 => setenv ethact SCC
5361 => ping 10.0.0.1 # traffic sent on SCC
5363 ethrotate - When set to "no" U-Boot does not go through all
5364 available network interfaces.
5365 It just stays at the currently selected interface.
5367 netretry - When set to "no" each network operation will
5368 either succeed or fail without retrying.
5369 When set to "once" the network operation will
5370 fail when all the available network interfaces
5371 are tried once without success.
5372 Useful on scripts which control the retry operation
5375 npe_ucode - set load address for the NPE microcode
5377 silent_linux - If set then Linux will be told to boot silently, by
5378 changing the console to be empty. If "yes" it will be
5379 made silent. If "no" it will not be made silent. If
5380 unset, then it will be made silent if the U-Boot console
5383 tftpsrcp - If this is set, the value is used for TFTP's
5386 tftpdstp - If this is set, the value is used for TFTP's UDP
5387 destination port instead of the Well Know Port 69.
5389 tftpblocksize - Block size to use for TFTP transfers; if not set,
5390 we use the TFTP server's default block size
5392 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5393 seconds, minimum value is 1000 = 1 second). Defines
5394 when a packet is considered to be lost so it has to
5395 be retransmitted. The default is 5000 = 5 seconds.
5396 Lowering this value may make downloads succeed
5397 faster in networks with high packet loss rates or
5398 with unreliable TFTP servers.
5400 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5401 unit, minimum value = 0). Defines how many timeouts
5402 can happen during a single file transfer before that
5403 transfer is aborted. The default is 10, and 0 means
5404 'no timeouts allowed'. Increasing this value may help
5405 downloads succeed with high packet loss rates, or with
5406 unreliable TFTP servers or client hardware.
5408 vlan - When set to a value < 4095 the traffic over
5409 Ethernet is encapsulated/received over 802.1q
5412 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5413 Unsigned value, in milliseconds. If not set, the period will
5414 be either the default (28000), or a value based on
5415 CONFIG_NET_RETRY_COUNT, if defined. This value has
5416 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5418 The following image location variables contain the location of images
5419 used in booting. The "Image" column gives the role of the image and is
5420 not an environment variable name. The other columns are environment
5421 variable names. "File Name" gives the name of the file on a TFTP
5422 server, "RAM Address" gives the location in RAM the image will be
5423 loaded to, and "Flash Location" gives the image's address in NOR
5424 flash or offset in NAND flash.
5426 *Note* - these variables don't have to be defined for all boards, some
5427 boards currently use other variables for these purposes, and some
5428 boards use these variables for other purposes.
5430 Image File Name RAM Address Flash Location
5431 ----- --------- ----------- --------------
5432 u-boot u-boot u-boot_addr_r u-boot_addr
5433 Linux kernel bootfile kernel_addr_r kernel_addr
5434 device tree blob fdtfile fdt_addr_r fdt_addr
5435 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5437 The following environment variables may be used and automatically
5438 updated by the network boot commands ("bootp" and "rarpboot"),
5439 depending the information provided by your boot server:
5441 bootfile - see above
5442 dnsip - IP address of your Domain Name Server
5443 dnsip2 - IP address of your secondary Domain Name Server
5444 gatewayip - IP address of the Gateway (Router) to use
5445 hostname - Target hostname
5447 netmask - Subnet Mask
5448 rootpath - Pathname of the root filesystem on the NFS server
5449 serverip - see above
5452 There are two special Environment Variables:
5454 serial# - contains hardware identification information such
5455 as type string and/or serial number
5456 ethaddr - Ethernet address
5458 These variables can be set only once (usually during manufacturing of
5459 the board). U-Boot refuses to delete or overwrite these variables
5460 once they have been set once.
5463 Further special Environment Variables:
5465 ver - Contains the U-Boot version string as printed
5466 with the "version" command. This variable is
5467 readonly (see CONFIG_VERSION_VARIABLE).
5470 Please note that changes to some configuration parameters may take
5471 only effect after the next boot (yes, that's just like Windoze :-).
5474 Callback functions for environment variables:
5475 ---------------------------------------------
5477 For some environment variables, the behavior of u-boot needs to change
5478 when their values are changed. This functionality allows functions to
5479 be associated with arbitrary variables. On creation, overwrite, or
5480 deletion, the callback will provide the opportunity for some side
5481 effect to happen or for the change to be rejected.
5483 The callbacks are named and associated with a function using the
5484 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5486 These callbacks are associated with variables in one of two ways. The
5487 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5488 in the board configuration to a string that defines a list of
5489 associations. The list must be in the following format:
5491 entry = variable_name[:callback_name]
5494 If the callback name is not specified, then the callback is deleted.
5495 Spaces are also allowed anywhere in the list.
5497 Callbacks can also be associated by defining the ".callbacks" variable
5498 with the same list format above. Any association in ".callbacks" will
5499 override any association in the static list. You can define
5500 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5501 ".callbacks" environment variable in the default or embedded environment.
5503 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5504 regular expression. This allows multiple variables to be connected to
5505 the same callback without explicitly listing them all out.
5508 Command Line Parsing:
5509 =====================
5511 There are two different command line parsers available with U-Boot:
5512 the old "simple" one, and the much more powerful "hush" shell:
5514 Old, simple command line parser:
5515 --------------------------------
5517 - supports environment variables (through setenv / saveenv commands)
5518 - several commands on one line, separated by ';'
5519 - variable substitution using "... ${name} ..." syntax
5520 - special characters ('$', ';') can be escaped by prefixing with '\',
5522 setenv bootcmd bootm \${address}
5523 - You can also escape text by enclosing in single apostrophes, for example:
5524 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5529 - similar to Bourne shell, with control structures like
5530 if...then...else...fi, for...do...done; while...do...done,
5531 until...do...done, ...
5532 - supports environment ("global") variables (through setenv / saveenv
5533 commands) and local shell variables (through standard shell syntax
5534 "name=value"); only environment variables can be used with "run"
5540 (1) If a command line (or an environment variable executed by a "run"
5541 command) contains several commands separated by semicolon, and
5542 one of these commands fails, then the remaining commands will be
5545 (2) If you execute several variables with one call to run (i. e.
5546 calling run with a list of variables as arguments), any failing
5547 command will cause "run" to terminate, i. e. the remaining
5548 variables are not executed.
5550 Note for Redundant Ethernet Interfaces:
5551 =======================================
5553 Some boards come with redundant Ethernet interfaces; U-Boot supports
5554 such configurations and is capable of automatic selection of a
5555 "working" interface when needed. MAC assignment works as follows:
5557 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5558 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5559 "eth1addr" (=>eth1), "eth2addr", ...
5561 If the network interface stores some valid MAC address (for instance
5562 in SROM), this is used as default address if there is NO correspon-
5563 ding setting in the environment; if the corresponding environment
5564 variable is set, this overrides the settings in the card; that means:
5566 o If the SROM has a valid MAC address, and there is no address in the
5567 environment, the SROM's address is used.
5569 o If there is no valid address in the SROM, and a definition in the
5570 environment exists, then the value from the environment variable is
5573 o If both the SROM and the environment contain a MAC address, and
5574 both addresses are the same, this MAC address is used.
5576 o If both the SROM and the environment contain a MAC address, and the
5577 addresses differ, the value from the environment is used and a
5580 o If neither SROM nor the environment contain a MAC address, an error
5581 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5582 a random, locally-assigned MAC is used.
5584 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5585 will be programmed into hardware as part of the initialization process. This
5586 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5587 The naming convention is as follows:
5588 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5593 U-Boot is capable of booting (and performing other auxiliary operations on)
5594 images in two formats:
5596 New uImage format (FIT)
5597 -----------------------
5599 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5600 to Flattened Device Tree). It allows the use of images with multiple
5601 components (several kernels, ramdisks, etc.), with contents protected by
5602 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5608 Old image format is based on binary files which can be basically anything,
5609 preceded by a special header; see the definitions in include/image.h for
5610 details; basically, the header defines the following image properties:
5612 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5613 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5614 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5615 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5617 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5618 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5619 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5620 * Compression Type (uncompressed, gzip, bzip2)
5626 The header is marked by a special Magic Number, and both the header
5627 and the data portions of the image are secured against corruption by
5634 Although U-Boot should support any OS or standalone application
5635 easily, the main focus has always been on Linux during the design of
5638 U-Boot includes many features that so far have been part of some
5639 special "boot loader" code within the Linux kernel. Also, any
5640 "initrd" images to be used are no longer part of one big Linux image;
5641 instead, kernel and "initrd" are separate images. This implementation
5642 serves several purposes:
5644 - the same features can be used for other OS or standalone
5645 applications (for instance: using compressed images to reduce the
5646 Flash memory footprint)
5648 - it becomes much easier to port new Linux kernel versions because
5649 lots of low-level, hardware dependent stuff are done by U-Boot
5651 - the same Linux kernel image can now be used with different "initrd"
5652 images; of course this also means that different kernel images can
5653 be run with the same "initrd". This makes testing easier (you don't
5654 have to build a new "zImage.initrd" Linux image when you just
5655 change a file in your "initrd"). Also, a field-upgrade of the
5656 software is easier now.
5662 Porting Linux to U-Boot based systems:
5663 ---------------------------------------
5665 U-Boot cannot save you from doing all the necessary modifications to
5666 configure the Linux device drivers for use with your target hardware
5667 (no, we don't intend to provide a full virtual machine interface to
5670 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5672 Just make sure your machine specific header file (for instance
5673 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5674 Information structure as we define in include/asm-<arch>/u-boot.h,
5675 and make sure that your definition of IMAP_ADDR uses the same value
5676 as your U-Boot configuration in CONFIG_SYS_IMMR.
5678 Note that U-Boot now has a driver model, a unified model for drivers.
5679 If you are adding a new driver, plumb it into driver model. If there
5680 is no uclass available, you are encouraged to create one. See
5684 Configuring the Linux kernel:
5685 -----------------------------
5687 No specific requirements for U-Boot. Make sure you have some root
5688 device (initial ramdisk, NFS) for your target system.
5691 Building a Linux Image:
5692 -----------------------
5694 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5695 not used. If you use recent kernel source, a new build target
5696 "uImage" will exist which automatically builds an image usable by
5697 U-Boot. Most older kernels also have support for a "pImage" target,
5698 which was introduced for our predecessor project PPCBoot and uses a
5699 100% compatible format.
5703 make TQM850L_defconfig
5708 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5709 encapsulate a compressed Linux kernel image with header information,
5710 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5712 * build a standard "vmlinux" kernel image (in ELF binary format):
5714 * convert the kernel into a raw binary image:
5716 ${CROSS_COMPILE}-objcopy -O binary \
5717 -R .note -R .comment \
5718 -S vmlinux linux.bin
5720 * compress the binary image:
5724 * package compressed binary image for U-Boot:
5726 mkimage -A ppc -O linux -T kernel -C gzip \
5727 -a 0 -e 0 -n "Linux Kernel Image" \
5728 -d linux.bin.gz uImage
5731 The "mkimage" tool can also be used to create ramdisk images for use
5732 with U-Boot, either separated from the Linux kernel image, or
5733 combined into one file. "mkimage" encapsulates the images with a 64
5734 byte header containing information about target architecture,
5735 operating system, image type, compression method, entry points, time
5736 stamp, CRC32 checksums, etc.
5738 "mkimage" can be called in two ways: to verify existing images and
5739 print the header information, or to build new images.
5741 In the first form (with "-l" option) mkimage lists the information
5742 contained in the header of an existing U-Boot image; this includes
5743 checksum verification:
5745 tools/mkimage -l image
5746 -l ==> list image header information
5748 The second form (with "-d" option) is used to build a U-Boot image
5749 from a "data file" which is used as image payload:
5751 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5752 -n name -d data_file image
5753 -A ==> set architecture to 'arch'
5754 -O ==> set operating system to 'os'
5755 -T ==> set image type to 'type'
5756 -C ==> set compression type 'comp'
5757 -a ==> set load address to 'addr' (hex)
5758 -e ==> set entry point to 'ep' (hex)
5759 -n ==> set image name to 'name'
5760 -d ==> use image data from 'datafile'
5762 Right now, all Linux kernels for PowerPC systems use the same load
5763 address (0x00000000), but the entry point address depends on the
5766 - 2.2.x kernels have the entry point at 0x0000000C,
5767 - 2.3.x and later kernels have the entry point at 0x00000000.
5769 So a typical call to build a U-Boot image would read:
5771 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5772 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5773 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5774 > examples/uImage.TQM850L
5775 Image Name: 2.4.4 kernel for TQM850L
5776 Created: Wed Jul 19 02:34:59 2000
5777 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5778 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5779 Load Address: 0x00000000
5780 Entry Point: 0x00000000
5782 To verify the contents of the image (or check for corruption):
5784 -> tools/mkimage -l 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 NOTE: for embedded systems where boot time is critical you can trade
5793 speed for memory and install an UNCOMPRESSED image instead: this
5794 needs more space in Flash, but boots much faster since it does not
5795 need to be uncompressed:
5797 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5798 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5799 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5800 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5801 > examples/uImage.TQM850L-uncompressed
5802 Image Name: 2.4.4 kernel for TQM850L
5803 Created: Wed Jul 19 02:34:59 2000
5804 Image Type: PowerPC Linux Kernel Image (uncompressed)
5805 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5806 Load Address: 0x00000000
5807 Entry Point: 0x00000000
5810 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5811 when your kernel is intended to use an initial ramdisk:
5813 -> tools/mkimage -n 'Simple Ramdisk Image' \
5814 > -A ppc -O linux -T ramdisk -C gzip \
5815 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5816 Image Name: Simple Ramdisk Image
5817 Created: Wed Jan 12 14:01:50 2000
5818 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5819 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5820 Load Address: 0x00000000
5821 Entry Point: 0x00000000
5823 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5824 option performs the converse operation of the mkimage's second form (the "-d"
5825 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5828 tools/dumpimage -i image -T type -p position data_file
5829 -i ==> extract from the 'image' a specific 'data_file'
5830 -T ==> set image type to 'type'
5831 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5834 Installing a Linux Image:
5835 -------------------------
5837 To downloading a U-Boot image over the serial (console) interface,
5838 you must convert the image to S-Record format:
5840 objcopy -I binary -O srec examples/image examples/image.srec
5842 The 'objcopy' does not understand the information in the U-Boot
5843 image header, so the resulting S-Record file will be relative to
5844 address 0x00000000. To load it to a given address, you need to
5845 specify the target address as 'offset' parameter with the 'loads'
5848 Example: install the image to address 0x40100000 (which on the
5849 TQM8xxL is in the first Flash bank):
5851 => erase 40100000 401FFFFF
5857 ## Ready for S-Record download ...
5858 ~>examples/image.srec
5859 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5861 15989 15990 15991 15992
5862 [file transfer complete]
5864 ## Start Addr = 0x00000000
5867 You can check the success of the download using the 'iminfo' command;
5868 this includes a checksum verification so you can be sure no data
5869 corruption happened:
5873 ## Checking Image at 40100000 ...
5874 Image Name: 2.2.13 for initrd on TQM850L
5875 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5876 Data Size: 335725 Bytes = 327 kB = 0 MB
5877 Load Address: 00000000
5878 Entry Point: 0000000c
5879 Verifying Checksum ... OK
5885 The "bootm" command is used to boot an application that is stored in
5886 memory (RAM or Flash). In case of a Linux kernel image, the contents
5887 of the "bootargs" environment variable is passed to the kernel as
5888 parameters. You can check and modify this variable using the
5889 "printenv" and "setenv" commands:
5892 => printenv bootargs
5893 bootargs=root=/dev/ram
5895 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5897 => printenv bootargs
5898 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5901 ## Booting Linux kernel at 40020000 ...
5902 Image Name: 2.2.13 for NFS on TQM850L
5903 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5904 Data Size: 381681 Bytes = 372 kB = 0 MB
5905 Load Address: 00000000
5906 Entry Point: 0000000c
5907 Verifying Checksum ... OK
5908 Uncompressing Kernel Image ... OK
5909 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
5910 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5911 time_init: decrementer frequency = 187500000/60
5912 Calibrating delay loop... 49.77 BogoMIPS
5913 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5916 If you want to boot a Linux kernel with initial RAM disk, you pass
5917 the memory addresses of both the kernel and the initrd image (PPBCOOT
5918 format!) to the "bootm" command:
5920 => imi 40100000 40200000
5922 ## Checking Image at 40100000 ...
5923 Image Name: 2.2.13 for initrd on TQM850L
5924 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5925 Data Size: 335725 Bytes = 327 kB = 0 MB
5926 Load Address: 00000000
5927 Entry Point: 0000000c
5928 Verifying Checksum ... OK
5930 ## Checking Image at 40200000 ...
5931 Image Name: Simple Ramdisk Image
5932 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5933 Data Size: 566530 Bytes = 553 kB = 0 MB
5934 Load Address: 00000000
5935 Entry Point: 00000000
5936 Verifying Checksum ... OK
5938 => bootm 40100000 40200000
5939 ## Booting Linux kernel at 40100000 ...
5940 Image Name: 2.2.13 for initrd on TQM850L
5941 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5942 Data Size: 335725 Bytes = 327 kB = 0 MB
5943 Load Address: 00000000
5944 Entry Point: 0000000c
5945 Verifying Checksum ... OK
5946 Uncompressing Kernel Image ... OK
5947 ## Loading RAMDisk Image at 40200000 ...
5948 Image Name: Simple Ramdisk Image
5949 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5950 Data Size: 566530 Bytes = 553 kB = 0 MB
5951 Load Address: 00000000
5952 Entry Point: 00000000
5953 Verifying Checksum ... OK
5954 Loading Ramdisk ... OK
5955 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
5956 Boot arguments: root=/dev/ram
5957 time_init: decrementer frequency = 187500000/60
5958 Calibrating delay loop... 49.77 BogoMIPS
5960 RAMDISK: Compressed image found at block 0
5961 VFS: Mounted root (ext2 filesystem).
5965 Boot Linux and pass a flat device tree:
5968 First, U-Boot must be compiled with the appropriate defines. See the section
5969 titled "Linux Kernel Interface" above for a more in depth explanation. The
5970 following is an example of how to start a kernel and pass an updated
5976 oft=oftrees/mpc8540ads.dtb
5977 => tftp $oftaddr $oft
5978 Speed: 1000, full duplex
5980 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5981 Filename 'oftrees/mpc8540ads.dtb'.
5982 Load address: 0x300000
5985 Bytes transferred = 4106 (100a hex)
5986 => tftp $loadaddr $bootfile
5987 Speed: 1000, full duplex
5989 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5991 Load address: 0x200000
5992 Loading:############
5994 Bytes transferred = 1029407 (fb51f hex)
5999 => bootm $loadaddr - $oftaddr
6000 ## Booting image at 00200000 ...
6001 Image Name: Linux-2.6.17-dirty
6002 Image Type: PowerPC Linux Kernel Image (gzip compressed)
6003 Data Size: 1029343 Bytes = 1005.2 kB
6004 Load Address: 00000000
6005 Entry Point: 00000000
6006 Verifying Checksum ... OK
6007 Uncompressing Kernel Image ... OK
6008 Booting using flat device tree at 0x300000
6009 Using MPC85xx ADS machine description
6010 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
6014 More About U-Boot Image Types:
6015 ------------------------------
6017 U-Boot supports the following image types:
6019 "Standalone Programs" are directly runnable in the environment
6020 provided by U-Boot; it is expected that (if they behave
6021 well) you can continue to work in U-Boot after return from
6022 the Standalone Program.
6023 "OS Kernel Images" are usually images of some Embedded OS which
6024 will take over control completely. Usually these programs
6025 will install their own set of exception handlers, device
6026 drivers, set up the MMU, etc. - this means, that you cannot
6027 expect to re-enter U-Boot except by resetting the CPU.
6028 "RAMDisk Images" are more or less just data blocks, and their
6029 parameters (address, size) are passed to an OS kernel that is
6031 "Multi-File Images" contain several images, typically an OS
6032 (Linux) kernel image and one or more data images like
6033 RAMDisks. This construct is useful for instance when you want
6034 to boot over the network using BOOTP etc., where the boot
6035 server provides just a single image file, but you want to get
6036 for instance an OS kernel and a RAMDisk image.
6038 "Multi-File Images" start with a list of image sizes, each
6039 image size (in bytes) specified by an "uint32_t" in network
6040 byte order. This list is terminated by an "(uint32_t)0".
6041 Immediately after the terminating 0 follow the images, one by
6042 one, all aligned on "uint32_t" boundaries (size rounded up to
6043 a multiple of 4 bytes).
6045 "Firmware Images" are binary images containing firmware (like
6046 U-Boot or FPGA images) which usually will be programmed to
6049 "Script files" are command sequences that will be executed by
6050 U-Boot's command interpreter; this feature is especially
6051 useful when you configure U-Boot to use a real shell (hush)
6052 as command interpreter.
6054 Booting the Linux zImage:
6055 -------------------------
6057 On some platforms, it's possible to boot Linux zImage. This is done
6058 using the "bootz" command. The syntax of "bootz" command is the same
6059 as the syntax of "bootm" command.
6061 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
6062 kernel with raw initrd images. The syntax is slightly different, the
6063 address of the initrd must be augmented by it's size, in the following
6064 format: "<initrd addres>:<initrd size>".
6070 One of the features of U-Boot is that you can dynamically load and
6071 run "standalone" applications, which can use some resources of
6072 U-Boot like console I/O functions or interrupt services.
6074 Two simple examples are included with the sources:
6079 'examples/hello_world.c' contains a small "Hello World" Demo
6080 application; it is automatically compiled when you build U-Boot.
6081 It's configured to run at address 0x00040004, so you can play with it
6085 ## Ready for S-Record download ...
6086 ~>examples/hello_world.srec
6087 1 2 3 4 5 6 7 8 9 10 11 ...
6088 [file transfer complete]
6090 ## Start Addr = 0x00040004
6092 => go 40004 Hello World! This is a test.
6093 ## Starting application at 0x00040004 ...
6104 Hit any key to exit ...
6106 ## Application terminated, rc = 0x0
6108 Another example, which demonstrates how to register a CPM interrupt
6109 handler with the U-Boot code, can be found in 'examples/timer.c'.
6110 Here, a CPM timer is set up to generate an interrupt every second.
6111 The interrupt service routine is trivial, just printing a '.'
6112 character, but this is just a demo program. The application can be
6113 controlled by the following keys:
6115 ? - print current values og the CPM Timer registers
6116 b - enable interrupts and start timer
6117 e - stop timer and disable interrupts
6118 q - quit application
6121 ## Ready for S-Record download ...
6122 ~>examples/timer.srec
6123 1 2 3 4 5 6 7 8 9 10 11 ...
6124 [file transfer complete]
6126 ## Start Addr = 0x00040004
6129 ## Starting application at 0x00040004 ...
6132 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
6135 [q, b, e, ?] Set interval 1000000 us
6138 [q, b, e, ?] ........
6139 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
6142 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
6145 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6148 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6150 [q, b, e, ?] ...Stopping timer
6152 [q, b, e, ?] ## Application terminated, rc = 0x0
6158 Over time, many people have reported problems when trying to use the
6159 "minicom" terminal emulation program for serial download. I (wd)
6160 consider minicom to be broken, and recommend not to use it. Under
6161 Unix, I recommend to use C-Kermit for general purpose use (and
6162 especially for kermit binary protocol download ("loadb" command), and
6163 use "cu" for S-Record download ("loads" command). See
6164 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6165 for help with kermit.
6168 Nevertheless, if you absolutely want to use it try adding this
6169 configuration to your "File transfer protocols" section:
6171 Name Program Name U/D FullScr IO-Red. Multi
6172 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6173 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6179 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6180 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6182 Building requires a cross environment; it is known to work on
6183 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6184 need gmake since the Makefiles are not compatible with BSD make).
6185 Note that the cross-powerpc package does not install include files;
6186 attempting to build U-Boot will fail because <machine/ansi.h> is
6187 missing. This file has to be installed and patched manually:
6189 # cd /usr/pkg/cross/powerpc-netbsd/include
6191 # ln -s powerpc machine
6192 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6193 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6195 Native builds *don't* work due to incompatibilities between native
6196 and U-Boot include files.
6198 Booting assumes that (the first part of) the image booted is a
6199 stage-2 loader which in turn loads and then invokes the kernel
6200 proper. Loader sources will eventually appear in the NetBSD source
6201 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6202 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6205 Implementation Internals:
6206 =========================
6208 The following is not intended to be a complete description of every
6209 implementation detail. However, it should help to understand the
6210 inner workings of U-Boot and make it easier to port it to custom
6214 Initial Stack, Global Data:
6215 ---------------------------
6217 The implementation of U-Boot is complicated by the fact that U-Boot
6218 starts running out of ROM (flash memory), usually without access to
6219 system RAM (because the memory controller is not initialized yet).
6220 This means that we don't have writable Data or BSS segments, and BSS
6221 is not initialized as zero. To be able to get a C environment working
6222 at all, we have to allocate at least a minimal stack. Implementation
6223 options for this are defined and restricted by the CPU used: Some CPU
6224 models provide on-chip memory (like the IMMR area on MPC8xx and
6225 MPC826x processors), on others (parts of) the data cache can be
6226 locked as (mis-) used as memory, etc.
6228 Chris Hallinan posted a good summary of these issues to the
6229 U-Boot mailing list:
6231 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6232 From: "Chris Hallinan" <clh@net1plus.com>
6233 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6236 Correct me if I'm wrong, folks, but the way I understand it
6237 is this: Using DCACHE as initial RAM for Stack, etc, does not
6238 require any physical RAM backing up the cache. The cleverness
6239 is that the cache is being used as a temporary supply of
6240 necessary storage before the SDRAM controller is setup. It's
6241 beyond the scope of this list to explain the details, but you
6242 can see how this works by studying the cache architecture and
6243 operation in the architecture and processor-specific manuals.
6245 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6246 is another option for the system designer to use as an
6247 initial stack/RAM area prior to SDRAM being available. Either
6248 option should work for you. Using CS 4 should be fine if your
6249 board designers haven't used it for something that would
6250 cause you grief during the initial boot! It is frequently not
6253 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6254 with your processor/board/system design. The default value
6255 you will find in any recent u-boot distribution in
6256 walnut.h should work for you. I'd set it to a value larger
6257 than your SDRAM module. If you have a 64MB SDRAM module, set
6258 it above 400_0000. Just make sure your board has no resources
6259 that are supposed to respond to that address! That code in
6260 start.S has been around a while and should work as is when
6261 you get the config right.
6266 It is essential to remember this, since it has some impact on the C
6267 code for the initialization procedures:
6269 * Initialized global data (data segment) is read-only. Do not attempt
6272 * Do not use any uninitialized global data (or implicitly initialized
6273 as zero data - BSS segment) at all - this is undefined, initiali-
6274 zation is performed later (when relocating to RAM).
6276 * Stack space is very limited. Avoid big data buffers or things like
6279 Having only the stack as writable memory limits means we cannot use
6280 normal global data to share information between the code. But it
6281 turned out that the implementation of U-Boot can be greatly
6282 simplified by making a global data structure (gd_t) available to all
6283 functions. We could pass a pointer to this data as argument to _all_
6284 functions, but this would bloat the code. Instead we use a feature of
6285 the GCC compiler (Global Register Variables) to share the data: we
6286 place a pointer (gd) to the global data into a register which we
6287 reserve for this purpose.
6289 When choosing a register for such a purpose we are restricted by the
6290 relevant (E)ABI specifications for the current architecture, and by
6291 GCC's implementation.
6293 For PowerPC, the following registers have specific use:
6295 R2: reserved for system use
6296 R3-R4: parameter passing and return values
6297 R5-R10: parameter passing
6298 R13: small data area pointer
6302 (U-Boot also uses R12 as internal GOT pointer. r12
6303 is a volatile register so r12 needs to be reset when
6304 going back and forth between asm and C)
6306 ==> U-Boot will use R2 to hold a pointer to the global data
6308 Note: on PPC, we could use a static initializer (since the
6309 address of the global data structure is known at compile time),
6310 but it turned out that reserving a register results in somewhat
6311 smaller code - although the code savings are not that big (on
6312 average for all boards 752 bytes for the whole U-Boot image,
6313 624 text + 127 data).
6315 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6316 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6318 ==> U-Boot will use P3 to hold a pointer to the global data
6320 On ARM, the following registers are used:
6322 R0: function argument word/integer result
6323 R1-R3: function argument word
6324 R9: platform specific
6325 R10: stack limit (used only if stack checking is enabled)
6326 R11: argument (frame) pointer
6327 R12: temporary workspace
6330 R15: program counter
6332 ==> U-Boot will use R9 to hold a pointer to the global data
6334 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6336 On Nios II, the ABI is documented here:
6337 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6339 ==> U-Boot will use gp to hold a pointer to the global data
6341 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6342 to access small data sections, so gp is free.
6344 On NDS32, the following registers are used:
6346 R0-R1: argument/return
6348 R15: temporary register for assembler
6349 R16: trampoline register
6350 R28: frame pointer (FP)
6351 R29: global pointer (GP)
6352 R30: link register (LP)
6353 R31: stack pointer (SP)
6354 PC: program counter (PC)
6356 ==> U-Boot will use R10 to hold a pointer to the global data
6358 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6359 or current versions of GCC may "optimize" the code too much.
6364 U-Boot runs in system state and uses physical addresses, i.e. the
6365 MMU is not used either for address mapping nor for memory protection.
6367 The available memory is mapped to fixed addresses using the memory
6368 controller. In this process, a contiguous block is formed for each
6369 memory type (Flash, SDRAM, SRAM), even when it consists of several
6370 physical memory banks.
6372 U-Boot is installed in the first 128 kB of the first Flash bank (on
6373 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6374 booting and sizing and initializing DRAM, the code relocates itself
6375 to the upper end of DRAM. Immediately below the U-Boot code some
6376 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6377 configuration setting]. Below that, a structure with global Board
6378 Info data is placed, followed by the stack (growing downward).
6380 Additionally, some exception handler code is copied to the low 8 kB
6381 of DRAM (0x00000000 ... 0x00001FFF).
6383 So a typical memory configuration with 16 MB of DRAM could look like
6386 0x0000 0000 Exception Vector code
6389 0x0000 2000 Free for Application Use
6395 0x00FB FF20 Monitor Stack (Growing downward)
6396 0x00FB FFAC Board Info Data and permanent copy of global data
6397 0x00FC 0000 Malloc Arena
6400 0x00FE 0000 RAM Copy of Monitor Code
6401 ... eventually: LCD or video framebuffer
6402 ... eventually: pRAM (Protected RAM - unchanged by reset)
6403 0x00FF FFFF [End of RAM]
6406 System Initialization:
6407 ----------------------
6409 In the reset configuration, U-Boot starts at the reset entry point
6410 (on most PowerPC systems at address 0x00000100). Because of the reset
6411 configuration for CS0# this is a mirror of the on board Flash memory.
6412 To be able to re-map memory U-Boot then jumps to its link address.
6413 To be able to implement the initialization code in C, a (small!)
6414 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6415 which provide such a feature like MPC8xx or MPC8260), or in a locked
6416 part of the data cache. After that, U-Boot initializes the CPU core,
6417 the caches and the SIU.
6419 Next, all (potentially) available memory banks are mapped using a
6420 preliminary mapping. For example, we put them on 512 MB boundaries
6421 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6422 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6423 programmed for SDRAM access. Using the temporary configuration, a
6424 simple memory test is run that determines the size of the SDRAM
6427 When there is more than one SDRAM bank, and the banks are of
6428 different size, the largest is mapped first. For equal size, the first
6429 bank (CS2#) is mapped first. The first mapping is always for address
6430 0x00000000, with any additional banks following immediately to create
6431 contiguous memory starting from 0.
6433 Then, the monitor installs itself at the upper end of the SDRAM area
6434 and allocates memory for use by malloc() and for the global Board
6435 Info data; also, the exception vector code is copied to the low RAM
6436 pages, and the final stack is set up.
6438 Only after this relocation will you have a "normal" C environment;
6439 until that you are restricted in several ways, mostly because you are
6440 running from ROM, and because the code will have to be relocated to a
6444 U-Boot Porting Guide:
6445 ----------------------
6447 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6451 int main(int argc, char *argv[])
6453 sighandler_t no_more_time;
6455 signal(SIGALRM, no_more_time);
6456 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6458 if (available_money > available_manpower) {
6459 Pay consultant to port U-Boot;
6463 Download latest U-Boot source;
6465 Subscribe to u-boot mailing list;
6468 email("Hi, I am new to U-Boot, how do I get started?");
6471 Read the README file in the top level directory;
6472 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6473 Read applicable doc/*.README;
6474 Read the source, Luke;
6475 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6478 if (available_money > toLocalCurrency ($2500))
6481 Add a lot of aggravation and time;
6483 if (a similar board exists) { /* hopefully... */
6484 cp -a board/<similar> board/<myboard>
6485 cp include/configs/<similar>.h include/configs/<myboard>.h
6487 Create your own board support subdirectory;
6488 Create your own board include/configs/<myboard>.h file;
6490 Edit new board/<myboard> files
6491 Edit new include/configs/<myboard>.h
6496 Add / modify source code;
6500 email("Hi, I am having problems...");
6502 Send patch file to the U-Boot email list;
6503 if (reasonable critiques)
6504 Incorporate improvements from email list code review;
6506 Defend code as written;
6512 void no_more_time (int sig)
6521 All contributions to U-Boot should conform to the Linux kernel
6522 coding style; see the file "Documentation/CodingStyle" and the script
6523 "scripts/Lindent" in your Linux kernel source directory.
6525 Source files originating from a different project (for example the
6526 MTD subsystem) are generally exempt from these guidelines and are not
6527 reformatted to ease subsequent migration to newer versions of those
6530 Please note that U-Boot is implemented in C (and to some small parts in
6531 Assembler); no C++ is used, so please do not use C++ style comments (//)
6534 Please also stick to the following formatting rules:
6535 - remove any trailing white space
6536 - use TAB characters for indentation and vertical alignment, not spaces
6537 - make sure NOT to use DOS '\r\n' line feeds
6538 - do not add more than 2 consecutive empty lines to source files
6539 - do not add trailing empty lines to source files
6541 Submissions which do not conform to the standards may be returned
6542 with a request to reformat the changes.
6548 Since the number of patches for U-Boot is growing, we need to
6549 establish some rules. Submissions which do not conform to these rules
6550 may be rejected, even when they contain important and valuable stuff.
6552 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6554 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6555 see http://lists.denx.de/mailman/listinfo/u-boot
6557 When you send a patch, please include the following information with
6560 * For bug fixes: a description of the bug and how your patch fixes
6561 this bug. Please try to include a way of demonstrating that the
6562 patch actually fixes something.
6564 * For new features: a description of the feature and your
6567 * A CHANGELOG entry as plaintext (separate from the patch)
6569 * For major contributions, add a MAINTAINERS file with your
6570 information and associated file and directory references.
6572 * When you add support for a new board, don't forget to add a
6573 maintainer e-mail address to the boards.cfg file, too.
6575 * If your patch adds new configuration options, don't forget to
6576 document these in the README file.
6578 * The patch itself. If you are using git (which is *strongly*
6579 recommended) you can easily generate the patch using the
6580 "git format-patch". If you then use "git send-email" to send it to
6581 the U-Boot mailing list, you will avoid most of the common problems
6582 with some other mail clients.
6584 If you cannot use git, use "diff -purN OLD NEW". If your version of
6585 diff does not support these options, then get the latest version of
6588 The current directory when running this command shall be the parent
6589 directory of the U-Boot source tree (i. e. please make sure that
6590 your patch includes sufficient directory information for the
6593 We prefer patches as plain text. MIME attachments are discouraged,
6594 and compressed attachments must not be used.
6596 * If one logical set of modifications affects or creates several
6597 files, all these changes shall be submitted in a SINGLE patch file.
6599 * Changesets that contain different, unrelated modifications shall be
6600 submitted as SEPARATE patches, one patch per changeset.
6605 * Before sending the patch, run the MAKEALL script on your patched
6606 source tree and make sure that no errors or warnings are reported
6607 for any of the boards.
6609 * Keep your modifications to the necessary minimum: A patch
6610 containing several unrelated changes or arbitrary reformats will be
6611 returned with a request to re-formatting / split it.
6613 * If you modify existing code, make sure that your new code does not
6614 add to the memory footprint of the code ;-) Small is beautiful!
6615 When adding new features, these should compile conditionally only
6616 (using #ifdef), and the resulting code with the new feature
6617 disabled must not need more memory than the old code without your
6620 * Remember that there is a size limit of 100 kB per message on the
6621 u-boot mailing list. Bigger patches will be moderated. If they are
6622 reasonable and not too big, they will be acknowledged. But patches
6623 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob