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 candidate 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 /m68k Files generic to m68k architecture
140 /microblaze Files generic to microblaze architecture
141 /mips Files generic to MIPS architecture
142 /nds32 Files generic to NDS32 architecture
143 /nios2 Files generic to Altera NIOS2 architecture
144 /openrisc Files generic to OpenRISC architecture
145 /powerpc Files generic to PowerPC architecture
146 /sandbox Files generic to HW-independent "sandbox"
147 /sh Files generic to SH architecture
148 /x86 Files generic to x86 architecture
149 /api Machine/arch independent API for external apps
150 /board Board dependent files
151 /cmd U-Boot commands functions
152 /common Misc architecture independent functions
153 /configs Board default configuration files
154 /disk Code for disk drive partition handling
155 /doc Documentation (don't expect too much)
156 /drivers Commonly used device drivers
157 /dts Contains Makefile for building internal U-Boot fdt.
158 /examples Example code for standalone applications, etc.
159 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
160 /include Header Files
161 /lib Library routines generic to all architectures
162 /Licenses Various license files
164 /post Power On Self Test
165 /scripts Various build scripts and Makefiles
166 /test Various unit test files
167 /tools Tools to build S-Record or U-Boot images, etc.
169 Software Configuration:
170 =======================
172 Configuration is usually done using C preprocessor defines; the
173 rationale behind that is to avoid dead code whenever possible.
175 There are two classes of configuration variables:
177 * Configuration _OPTIONS_:
178 These are selectable by the user and have names beginning with
181 * Configuration _SETTINGS_:
182 These depend on the hardware etc. and should not be meddled with if
183 you don't know what you're doing; they have names beginning with
186 Previously, all configuration was done by hand, which involved creating
187 symbolic links and editing configuration files manually. More recently,
188 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
189 allowing you to use the "make menuconfig" command to configure your
193 Selection of Processor Architecture and Board Type:
194 ---------------------------------------------------
196 For all supported boards there are ready-to-use default
197 configurations available; just type "make <board_name>_defconfig".
199 Example: For a TQM823L module type:
202 make TQM823L_defconfig
204 Note: If you're looking for the default configuration file for a board
205 you're sure used to be there but is now missing, check the file
206 doc/README.scrapyard for a list of no longer supported boards.
211 U-Boot can be built natively to run on a Linux host using the 'sandbox'
212 board. This allows feature development which is not board- or architecture-
213 specific to be undertaken on a native platform. The sandbox is also used to
214 run some of U-Boot's tests.
216 See board/sandbox/README.sandbox for more details.
219 Board Initialisation Flow:
220 --------------------------
222 This is the intended start-up flow for boards. This should apply for both
223 SPL and U-Boot proper (i.e. they both follow the same rules).
225 Note: "SPL" stands for "Secondary Program Loader," which is explained in
226 more detail later in this file.
228 At present, SPL mostly uses a separate code path, but the function names
229 and roles of each function are the same. Some boards or architectures
230 may not conform to this. At least most ARM boards which use
231 CONFIG_SPL_FRAMEWORK conform to this.
233 Execution typically starts with an architecture-specific (and possibly
234 CPU-specific) start.S file, such as:
236 - arch/arm/cpu/armv7/start.S
237 - arch/powerpc/cpu/mpc83xx/start.S
238 - arch/mips/cpu/start.S
240 and so on. From there, three functions are called; the purpose and
241 limitations of each of these functions are described below.
244 - purpose: essential init to permit execution to reach board_init_f()
245 - no global_data or BSS
246 - there is no stack (ARMv7 may have one but it will soon be removed)
247 - must not set up SDRAM or use console
248 - must only do the bare minimum to allow execution to continue to
250 - this is almost never needed
251 - return normally from this function
254 - purpose: set up the machine ready for running board_init_r():
255 i.e. SDRAM and serial UART
256 - global_data is available
258 - BSS is not available, so you cannot use global/static variables,
259 only stack variables and global_data
261 Non-SPL-specific notes:
262 - dram_init() is called to set up DRAM. If already done in SPL this
266 - you can override the entire board_init_f() function with your own
268 - preloader_console_init() can be called here in extremis
269 - should set up SDRAM, and anything needed to make the UART work
270 - these is no need to clear BSS, it will be done by crt0.S
271 - must return normally from this function (don't call board_init_r()
274 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
275 this point the stack and global_data are relocated to below
276 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
280 - purpose: main execution, common code
281 - global_data is available
283 - BSS is available, all static/global variables can be used
284 - execution eventually continues to main_loop()
286 Non-SPL-specific notes:
287 - U-Boot is relocated to the top of memory and is now running from
291 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
292 CONFIG_SPL_STACK_R_ADDR points into SDRAM
293 - preloader_console_init() can be called here - typically this is
294 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
295 spl_board_init() function containing this call
296 - loads U-Boot or (in falcon mode) Linux
300 Configuration Options:
301 ----------------------
303 Configuration depends on the combination of board and CPU type; all
304 such information is kept in a configuration file
305 "include/configs/<board_name>.h".
307 Example: For a TQM823L module, all configuration settings are in
308 "include/configs/TQM823L.h".
311 Many of the options are named exactly as the corresponding Linux
312 kernel configuration options. The intention is to make it easier to
313 build a config tool - later.
316 The following options need to be configured:
318 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
320 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
322 - Marvell Family Member
323 CONFIG_SYS_MVFS - define it if you want to enable
324 multiple fs option at one time
325 for marvell soc family
330 Specifies that the core is a 64-bit PowerPC implementation (implements
331 the "64" category of the Power ISA). This is necessary for ePAPR
332 compliance, among other possible reasons.
334 CONFIG_SYS_FSL_TBCLK_DIV
336 Defines the core time base clock divider ratio compared to the
337 system clock. On most PQ3 devices this is 8, on newer QorIQ
338 devices it can be 16 or 32. The ratio varies from SoC to Soc.
340 CONFIG_SYS_FSL_PCIE_COMPAT
342 Defines the string to utilize when trying to match PCIe device
343 tree nodes for the given platform.
345 CONFIG_SYS_FSL_ERRATUM_A004510
347 Enables a workaround for erratum A004510. If set,
348 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
349 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
351 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
352 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
354 Defines one or two SoC revisions (low 8 bits of SVR)
355 for which the A004510 workaround should be applied.
357 The rest of SVR is either not relevant to the decision
358 of whether the erratum is present (e.g. p2040 versus
359 p2041) or is implied by the build target, which controls
360 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
362 See Freescale App Note 4493 for more information about
365 CONFIG_A003399_NOR_WORKAROUND
366 Enables a workaround for IFC erratum A003399. It is only
367 required during NOR boot.
369 CONFIG_A008044_WORKAROUND
370 Enables a workaround for T1040/T1042 erratum A008044. It is only
371 required during NAND boot and valid for Rev 1.0 SoC revision
373 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
375 This is the value to write into CCSR offset 0x18600
376 according to the A004510 workaround.
378 CONFIG_SYS_FSL_DSP_DDR_ADDR
379 This value denotes start offset of DDR memory which is
380 connected exclusively to the DSP cores.
382 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
383 This value denotes start offset of M2 memory
384 which is directly connected to the DSP core.
386 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
387 This value denotes start offset of M3 memory which is directly
388 connected to the DSP core.
390 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
391 This value denotes start offset of DSP CCSR space.
393 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
394 Single Source Clock is clocking mode present in some of FSL SoC's.
395 In this mode, a single differential clock is used to supply
396 clocks to the sysclock, ddrclock and usbclock.
398 CONFIG_SYS_CPC_REINIT_F
399 This CONFIG is defined when the CPC is configured as SRAM at the
400 time of U-Boot entry and is required to be re-initialized.
403 Indicates this SoC supports deep sleep feature. If deep sleep is
404 supported, core will start to execute uboot when wakes up.
406 - Generic CPU options:
407 CONFIG_SYS_GENERIC_GLOBAL_DATA
408 Defines global data is initialized in generic board board_init_f().
409 If this macro is defined, global data is created and cleared in
410 generic board board_init_f(). Without this macro, architecture/board
411 should initialize global data before calling board_init_f().
413 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
415 Defines the endianess of the CPU. Implementation of those
416 values is arch specific.
419 Freescale DDR driver in use. This type of DDR controller is
420 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
423 CONFIG_SYS_FSL_DDR_ADDR
424 Freescale DDR memory-mapped register base.
426 CONFIG_SYS_FSL_DDR_EMU
427 Specify emulator support for DDR. Some DDR features such as
428 deskew training are not available.
430 CONFIG_SYS_FSL_DDRC_GEN1
431 Freescale DDR1 controller.
433 CONFIG_SYS_FSL_DDRC_GEN2
434 Freescale DDR2 controller.
436 CONFIG_SYS_FSL_DDRC_GEN3
437 Freescale DDR3 controller.
439 CONFIG_SYS_FSL_DDRC_GEN4
440 Freescale DDR4 controller.
442 CONFIG_SYS_FSL_DDRC_ARM_GEN3
443 Freescale DDR3 controller for ARM-based SoCs.
446 Board config to use DDR1. It can be enabled for SoCs with
447 Freescale DDR1 or DDR2 controllers, depending on the board
451 Board config to use DDR2. It can be enabled for SoCs with
452 Freescale DDR2 or DDR3 controllers, depending on the board
456 Board config to use DDR3. It can be enabled for SoCs with
457 Freescale DDR3 or DDR3L controllers.
460 Board config to use DDR3L. It can be enabled for SoCs with
464 Board config to use DDR4. It can be enabled for SoCs with
467 CONFIG_SYS_FSL_IFC_BE
468 Defines the IFC controller register space as Big Endian
470 CONFIG_SYS_FSL_IFC_LE
471 Defines the IFC controller register space as Little Endian
473 CONFIG_SYS_FSL_IFC_CLK_DIV
474 Defines divider of platform clock(clock input to IFC controller).
476 CONFIG_SYS_FSL_LBC_CLK_DIV
477 Defines divider of platform clock(clock input to eLBC controller).
479 CONFIG_SYS_FSL_PBL_PBI
480 It enables addition of RCW (Power on reset configuration) in built image.
481 Please refer doc/README.pblimage for more details
483 CONFIG_SYS_FSL_PBL_RCW
484 It adds PBI(pre-boot instructions) commands in u-boot build image.
485 PBI commands can be used to configure SoC before it starts the execution.
486 Please refer doc/README.pblimage for more details
489 It adds a target to create boot binary having SPL binary in PBI format
490 concatenated with u-boot binary.
492 CONFIG_SYS_FSL_DDR_BE
493 Defines the DDR controller register space as Big Endian
495 CONFIG_SYS_FSL_DDR_LE
496 Defines the DDR controller register space as Little Endian
498 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
499 Physical address from the view of DDR controllers. It is the
500 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
501 it could be different for ARM SoCs.
503 CONFIG_SYS_FSL_DDR_INTLV_256B
504 DDR controller interleaving on 256-byte. This is a special
505 interleaving mode, handled by Dickens for Freescale layerscape
508 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
509 Number of controllers used as main memory.
511 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
512 Number of controllers used for other than main memory.
514 CONFIG_SYS_FSL_HAS_DP_DDR
515 Defines the SoC has DP-DDR used for DPAA.
517 CONFIG_SYS_FSL_SEC_BE
518 Defines the SEC controller register space as Big Endian
520 CONFIG_SYS_FSL_SEC_LE
521 Defines the SEC controller register space as Little Endian
524 CONFIG_SYS_INIT_SP_OFFSET
526 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
527 pointer. This is needed for the temporary stack before
530 CONFIG_SYS_MIPS_CACHE_MODE
532 Cache operation mode for the MIPS CPU.
533 See also arch/mips/include/asm/mipsregs.h.
535 CONF_CM_CACHABLE_NO_WA
538 CONF_CM_CACHABLE_NONCOHERENT
542 CONF_CM_CACHABLE_ACCELERATED
544 CONFIG_SYS_XWAY_EBU_BOOTCFG
546 Special option for Lantiq XWAY SoCs for booting from NOR flash.
547 See also arch/mips/cpu/mips32/start.S.
549 CONFIG_XWAY_SWAP_BYTES
551 Enable compilation of tools/xway-swap-bytes needed for Lantiq
552 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
553 be swapped if a flash programmer is used.
556 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
558 Select high exception vectors of the ARM core, e.g., do not
559 clear the V bit of the c1 register of CP15.
562 Generic timer clock source frequency.
564 COUNTER_FREQUENCY_REAL
565 Generic timer clock source frequency if the real clock is
566 different from COUNTER_FREQUENCY, and can only be determined
570 CONFIG_TEGRA_SUPPORT_NON_SECURE
572 Support executing U-Boot in non-secure (NS) mode. Certain
573 impossible actions will be skipped if the CPU is in NS mode,
574 such as ARM architectural timer initialization.
576 - Linux Kernel Interface:
579 U-Boot stores all clock information in Hz
580 internally. For binary compatibility with older Linux
581 kernels (which expect the clocks passed in the
582 bd_info data to be in MHz) the environment variable
583 "clocks_in_mhz" can be defined so that U-Boot
584 converts clock data to MHZ before passing it to the
586 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
587 "clocks_in_mhz=1" is automatically included in the
590 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
592 When transferring memsize parameter to Linux, some versions
593 expect it to be in bytes, others in MB.
594 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
598 New kernel versions are expecting firmware settings to be
599 passed using flattened device trees (based on open firmware
603 * New libfdt-based support
604 * Adds the "fdt" command
605 * The bootm command automatically updates the fdt
607 OF_TBCLK - The timebase frequency.
608 OF_STDOUT_PATH - The path to the console device
610 boards with QUICC Engines require OF_QE to set UCC MAC
613 CONFIG_OF_BOARD_SETUP
615 Board code has addition modification that it wants to make
616 to the flat device tree before handing it off to the kernel
618 CONFIG_OF_SYSTEM_SETUP
620 Other code has addition modification that it wants to make
621 to the flat device tree before handing it off to the kernel.
622 This causes ft_system_setup() to be called before booting
627 U-Boot can detect if an IDE device is present or not.
628 If not, and this new config option is activated, U-Boot
629 removes the ATA node from the DTS before booting Linux,
630 so the Linux IDE driver does not probe the device and
631 crash. This is needed for buggy hardware (uc101) where
632 no pull down resistor is connected to the signal IDE5V_DD7.
634 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
636 This setting is mandatory for all boards that have only one
637 machine type and must be used to specify the machine type
638 number as it appears in the ARM machine registry
639 (see http://www.arm.linux.org.uk/developer/machines/).
640 Only boards that have multiple machine types supported
641 in a single configuration file and the machine type is
642 runtime discoverable, do not have to use this setting.
644 - vxWorks boot parameters:
646 bootvx constructs a valid bootline using the following
647 environments variables: bootdev, bootfile, ipaddr, netmask,
648 serverip, gatewayip, hostname, othbootargs.
649 It loads the vxWorks image pointed bootfile.
651 Note: If a "bootargs" environment is defined, it will overwride
652 the defaults discussed just above.
654 - Cache Configuration:
655 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
656 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
657 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
659 - Cache Configuration for ARM:
660 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
662 CONFIG_SYS_PL310_BASE - Physical base address of PL310
663 controller register space
668 Define this if you want support for Amba PrimeCell PL010 UARTs.
672 Define this if you want support for Amba PrimeCell PL011 UARTs.
676 If you have Amba PrimeCell PL011 UARTs, set this variable to
677 the clock speed of the UARTs.
681 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
682 define this to a list of base addresses for each (supported)
683 port. See e.g. include/configs/versatile.h
685 CONFIG_SERIAL_HW_FLOW_CONTROL
687 Define this variable to enable hw flow control in serial driver.
688 Current user of this option is drivers/serial/nsl16550.c driver
691 CONFIG_BAUDRATE - in bps
692 Select one of the baudrates listed in
693 CONFIG_SYS_BAUDRATE_TABLE, see below.
697 Only needed when CONFIG_BOOTDELAY is enabled;
698 define a command string that is automatically executed
699 when no character is read on the console interface
700 within "Boot Delay" after reset.
703 This can be used to pass arguments to the bootm
704 command. The value of CONFIG_BOOTARGS goes into the
705 environment value "bootargs".
707 CONFIG_RAMBOOT and CONFIG_NFSBOOT
708 The value of these goes into the environment as
709 "ramboot" and "nfsboot" respectively, and can be used
710 as a convenience, when switching between booting from
714 CONFIG_BOOTCOUNT_LIMIT
715 Implements a mechanism for detecting a repeating reboot
717 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
720 If no softreset save registers are found on the hardware
721 "bootcount" is stored in the environment. To prevent a
722 saveenv on all reboots, the environment variable
723 "upgrade_available" is used. If "upgrade_available" is
724 0, "bootcount" is always 0, if "upgrade_available" is
725 1 "bootcount" is incremented in the environment.
726 So the Userspace Applikation must set the "upgrade_available"
727 and "bootcount" variable to 0, if a boot was successfully.
732 When this option is #defined, the existence of the
733 environment variable "preboot" will be checked
734 immediately before starting the CONFIG_BOOTDELAY
735 countdown and/or running the auto-boot command resp.
736 entering interactive mode.
738 This feature is especially useful when "preboot" is
739 automatically generated or modified. For an example
740 see the LWMON board specific code: here "preboot" is
741 modified when the user holds down a certain
742 combination of keys on the (special) keyboard when
745 - Serial Download Echo Mode:
747 If defined to 1, all characters received during a
748 serial download (using the "loads" command) are
749 echoed back. This might be needed by some terminal
750 emulations (like "cu"), but may as well just take
751 time on others. This setting #define's the initial
752 value of the "loads_echo" environment variable.
754 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
756 Select one of the baudrates listed in
757 CONFIG_SYS_BAUDRATE_TABLE, see below.
760 Monitor commands can be included or excluded
761 from the build by using the #include files
762 <config_cmd_all.h> and #undef'ing unwanted
763 commands, or adding #define's for wanted commands.
765 The default command configuration includes all commands
766 except those marked below with a "*".
768 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
769 CONFIG_CMD_ASKENV * ask for env variable
770 CONFIG_CMD_BDI bdinfo
771 CONFIG_CMD_BOOTD bootd
772 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
773 CONFIG_CMD_CACHE * icache, dcache
774 CONFIG_CMD_CONSOLE coninfo
775 CONFIG_CMD_DHCP * DHCP support
776 CONFIG_CMD_DIAG * Diagnostics
777 CONFIG_CMD_ECHO echo arguments
778 CONFIG_CMD_EDITENV edit env variable
779 CONFIG_CMD_ELF * bootelf, bootvx
780 CONFIG_CMD_ENV_EXISTS * check existence of env variable
781 CONFIG_CMD_EXPORTENV * export the environment
782 CONFIG_CMD_EXT2 * ext2 command support
783 CONFIG_CMD_EXT4 * ext4 command support
784 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
785 that work for multiple fs types
786 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
787 CONFIG_CMD_SAVEENV saveenv
788 CONFIG_CMD_FLASH flinfo, erase, protect
789 CONFIG_CMD_FPGA FPGA device initialization support
790 CONFIG_CMD_GO * the 'go' command (exec code)
791 CONFIG_CMD_GREPENV * search environment
792 CONFIG_CMD_I2C * I2C serial bus support
793 CONFIG_CMD_IMI iminfo
794 CONFIG_CMD_IMLS List all images found in NOR flash
795 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
796 CONFIG_CMD_IMPORTENV * import an environment
797 CONFIG_CMD_INI * import data from an ini file into the env
798 CONFIG_CMD_ITEST Integer/string test of 2 values
799 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
800 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
802 CONFIG_CMD_LOADB loadb
803 CONFIG_CMD_LOADS loads
804 CONFIG_CMD_MD5SUM * print md5 message digest
805 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
806 CONFIG_CMD_MEMINFO * Display detailed memory information
807 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
809 CONFIG_CMD_MEMTEST * mtest
810 CONFIG_CMD_MISC Misc functions like sleep etc
811 CONFIG_CMD_MMC * MMC memory mapped support
812 CONFIG_CMD_MII * MII utility commands
813 CONFIG_CMD_NET bootp, tftpboot, rarpboot
814 CONFIG_CMD_NFS NFS support
815 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
816 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
817 CONFIG_CMD_PCI * pciinfo
818 CONFIG_CMD_PCMCIA * PCMCIA support
819 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
821 CONFIG_CMD_PORTIO * Port I/O
822 CONFIG_CMD_READ * Read raw data from partition
823 CONFIG_CMD_REGINFO * Register dump
824 CONFIG_CMD_RUN run command in env variable
825 CONFIG_CMD_SANDBOX * sb command to access sandbox features
826 CONFIG_CMD_SAVES * save S record dump
827 CONFIG_CMD_SDRAM * print SDRAM configuration information
828 (requires CONFIG_CMD_I2C)
829 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
830 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
831 CONFIG_CMD_SOURCE "source" command Support
832 CONFIG_CMD_SPI * SPI serial bus support
833 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
834 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
835 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
836 CONFIG_CMD_TIMER * access to the system tick timer
837 CONFIG_CMD_USB * USB support
838 CONFIG_CMD_CDP * Cisco Discover Protocol support
839 CONFIG_CMD_XIMG Load part of Multi Image
840 CONFIG_CMD_UUID * Generate random UUID or GUID string
842 EXAMPLE: If you want all functions except of network
843 support you can write:
845 #include "config_cmd_all.h"
846 #undef CONFIG_CMD_NET
849 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
851 Note: Don't enable the "icache" and "dcache" commands
852 (configuration option CONFIG_CMD_CACHE) unless you know
853 what you (and your U-Boot users) are doing. Data
854 cache cannot be enabled on systems like the
855 8xx (where accesses to the IMMR region must be
856 uncached), and it cannot be disabled on all other
857 systems where we (mis-) use the data cache to hold an
858 initial stack and some data.
861 XXX - this list needs to get updated!
863 - Removal of commands
864 If no commands are needed to boot, you can disable
865 CONFIG_CMDLINE to remove them. In this case, the command line
866 will not be available, and when U-Boot wants to execute the
867 boot command (on start-up) it will call board_run_command()
868 instead. This can reduce image size significantly for very
869 simple boot procedures.
871 - Regular expression support:
873 If this variable is defined, U-Boot is linked against
874 the SLRE (Super Light Regular Expression) library,
875 which adds regex support to some commands, as for
876 example "env grep" and "setexpr".
880 If this variable is defined, U-Boot will use a device tree
881 to configure its devices, instead of relying on statically
882 compiled #defines in the board file. This option is
883 experimental and only available on a few boards. The device
884 tree is available in the global data as gd->fdt_blob.
886 U-Boot needs to get its device tree from somewhere. This can
887 be done using one of the three options below:
890 If this variable is defined, U-Boot will embed a device tree
891 binary in its image. This device tree file should be in the
892 board directory and called <soc>-<board>.dts. The binary file
893 is then picked up in board_init_f() and made available through
894 the global data structure as gd->blob.
897 If this variable is defined, U-Boot will build a device tree
898 binary. It will be called u-boot.dtb. Architecture-specific
899 code will locate it at run-time. Generally this works by:
901 cat u-boot.bin u-boot.dtb >image.bin
903 and in fact, U-Boot does this for you, creating a file called
904 u-boot-dtb.bin which is useful in the common case. You can
905 still use the individual files if you need something more
909 If this variable is defined, U-Boot will use the device tree
910 provided by the board at runtime instead of embedding one with
911 the image. Only boards defining board_fdt_blob_setup() support
912 this option (see include/fdtdec.h file).
916 If this variable is defined, it enables watchdog
917 support for the SoC. There must be support in the SoC
918 specific code for a watchdog. For the 8xx
919 CPUs, the SIU Watchdog feature is enabled in the SYPCR
920 register. When supported for a specific SoC is
921 available, then no further board specific code should
925 When using a watchdog circuitry external to the used
926 SoC, then define this variable and provide board
927 specific code for the "hw_watchdog_reset" function.
929 CONFIG_AT91_HW_WDT_TIMEOUT
930 specify the timeout in seconds. default 2 seconds.
933 CONFIG_VERSION_VARIABLE
934 If this variable is defined, an environment variable
935 named "ver" is created by U-Boot showing the U-Boot
936 version as printed by the "version" command.
937 Any change to this variable will be reverted at the
942 When CONFIG_CMD_DATE is selected, the type of the RTC
943 has to be selected, too. Define exactly one of the
946 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
947 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
948 CONFIG_RTC_MC146818 - use MC146818 RTC
949 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
950 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
951 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
952 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
953 CONFIG_RTC_DS164x - use Dallas DS164x RTC
954 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
955 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
956 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
957 CONFIG_SYS_RV3029_TCR - enable trickle charger on
960 Note that if the RTC uses I2C, then the I2C interface
961 must also be configured. See I2C Support, below.
964 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
966 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
967 chip-ngpio pairs that tell the PCA953X driver the number of
968 pins supported by a particular chip.
970 Note that if the GPIO device uses I2C, then the I2C interface
971 must also be configured. See I2C Support, below.
974 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
975 accesses and can checksum them or write a list of them out
976 to memory. See the 'iotrace' command for details. This is
977 useful for testing device drivers since it can confirm that
978 the driver behaves the same way before and after a code
979 change. Currently this is supported on sandbox and arm. To
980 add support for your architecture, add '#include <iotrace.h>'
981 to the bottom of arch/<arch>/include/asm/io.h and test.
983 Example output from the 'iotrace stats' command is below.
984 Note that if the trace buffer is exhausted, the checksum will
985 still continue to operate.
988 Start: 10000000 (buffer start address)
989 Size: 00010000 (buffer size)
990 Offset: 00000120 (current buffer offset)
991 Output: 10000120 (start + offset)
992 Count: 00000018 (number of trace records)
993 CRC32: 9526fb66 (CRC32 of all trace records)
997 When CONFIG_TIMESTAMP is selected, the timestamp
998 (date and time) of an image is printed by image
999 commands like bootm or iminfo. This option is
1000 automatically enabled when you select CONFIG_CMD_DATE .
1002 - Partition Labels (disklabels) Supported:
1003 Zero or more of the following:
1004 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1005 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1006 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1007 bootloader. Note 2TB partition limit; see
1009 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1011 If IDE or SCSI support is enabled (CONFIG_IDE or
1012 CONFIG_SCSI) you must configure support for at
1013 least one non-MTD partition type as well.
1016 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1017 board configurations files but used nowhere!
1019 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1020 be performed by calling the function
1021 ide_set_reset(int reset)
1022 which has to be defined in a board specific file
1027 Set this to enable ATAPI support.
1032 Set this to enable support for disks larger than 137GB
1033 Also look at CONFIG_SYS_64BIT_LBA.
1034 Whithout these , LBA48 support uses 32bit variables and will 'only'
1035 support disks up to 2.1TB.
1037 CONFIG_SYS_64BIT_LBA:
1038 When enabled, makes the IDE subsystem use 64bit sector addresses.
1042 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1043 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1044 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1045 maximum numbers of LUNs, SCSI ID's and target
1048 The environment variable 'scsidevs' is set to the number of
1049 SCSI devices found during the last scan.
1051 - NETWORK Support (PCI):
1053 Support for Intel 8254x/8257x gigabit chips.
1056 Utility code for direct access to the SPI bus on Intel 8257x.
1057 This does not do anything useful unless you set at least one
1058 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1060 CONFIG_E1000_SPI_GENERIC
1061 Allow generic access to the SPI bus on the Intel 8257x, for
1062 example with the "sspi" command.
1065 Management command for E1000 devices. When used on devices
1066 with SPI support you can reprogram the EEPROM from U-Boot.
1069 Support for Intel 82557/82559/82559ER chips.
1070 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1071 write routine for first time initialisation.
1074 Support for Digital 2114x chips.
1075 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1076 modem chip initialisation (KS8761/QS6611).
1079 Support for National dp83815 chips.
1082 Support for National dp8382[01] gigabit chips.
1084 - NETWORK Support (other):
1086 CONFIG_DRIVER_AT91EMAC
1087 Support for AT91RM9200 EMAC.
1090 Define this to use reduced MII inteface
1092 CONFIG_DRIVER_AT91EMAC_QUIET
1093 If this defined, the driver is quiet.
1094 The driver doen't show link status messages.
1096 CONFIG_CALXEDA_XGMAC
1097 Support for the Calxeda XGMAC device
1100 Support for SMSC's LAN91C96 chips.
1102 CONFIG_LAN91C96_USE_32_BIT
1103 Define this to enable 32 bit addressing
1106 Support for SMSC's LAN91C111 chip
1108 CONFIG_SMC91111_BASE
1109 Define this to hold the physical address
1110 of the device (I/O space)
1112 CONFIG_SMC_USE_32_BIT
1113 Define this if data bus is 32 bits
1115 CONFIG_SMC_USE_IOFUNCS
1116 Define this to use i/o functions instead of macros
1117 (some hardware wont work with macros)
1119 CONFIG_DRIVER_TI_EMAC
1120 Support for davinci emac
1122 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1123 Define this if you have more then 3 PHYs.
1126 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1128 CONFIG_FTGMAC100_EGIGA
1129 Define this to use GE link update with gigabit PHY.
1130 Define this if FTGMAC100 is connected to gigabit PHY.
1131 If your system has 10/100 PHY only, it might not occur
1132 wrong behavior. Because PHY usually return timeout or
1133 useless data when polling gigabit status and gigabit
1134 control registers. This behavior won't affect the
1135 correctnessof 10/100 link speed update.
1138 Support for SMSC's LAN911x and LAN921x chips
1141 Define this to hold the physical address
1142 of the device (I/O space)
1144 CONFIG_SMC911X_32_BIT
1145 Define this if data bus is 32 bits
1147 CONFIG_SMC911X_16_BIT
1148 Define this if data bus is 16 bits. If your processor
1149 automatically converts one 32 bit word to two 16 bit
1150 words you may also try CONFIG_SMC911X_32_BIT.
1153 Support for Renesas on-chip Ethernet controller
1155 CONFIG_SH_ETHER_USE_PORT
1156 Define the number of ports to be used
1158 CONFIG_SH_ETHER_PHY_ADDR
1159 Define the ETH PHY's address
1161 CONFIG_SH_ETHER_CACHE_WRITEBACK
1162 If this option is set, the driver enables cache flush.
1166 Support for PWM module on the imx6.
1170 Support TPM devices.
1172 CONFIG_TPM_TIS_INFINEON
1173 Support for Infineon i2c bus TPM devices. Only one device
1174 per system is supported at this time.
1176 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1177 Define the burst count bytes upper limit
1180 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1182 CONFIG_TPM_ST33ZP24_I2C
1183 Support for STMicroelectronics ST33ZP24 I2C devices.
1184 Requires TPM_ST33ZP24 and I2C.
1186 CONFIG_TPM_ST33ZP24_SPI
1187 Support for STMicroelectronics ST33ZP24 SPI devices.
1188 Requires TPM_ST33ZP24 and SPI.
1190 CONFIG_TPM_ATMEL_TWI
1191 Support for Atmel TWI TPM device. Requires I2C support.
1194 Support for generic parallel port TPM devices. Only one device
1195 per system is supported at this time.
1197 CONFIG_TPM_TIS_BASE_ADDRESS
1198 Base address where the generic TPM device is mapped
1199 to. Contemporary x86 systems usually map it at
1203 Add tpm monitor functions.
1204 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1205 provides monitor access to authorized functions.
1208 Define this to enable the TPM support library which provides
1209 functional interfaces to some TPM commands.
1210 Requires support for a TPM device.
1212 CONFIG_TPM_AUTH_SESSIONS
1213 Define this to enable authorized functions in the TPM library.
1214 Requires CONFIG_TPM and CONFIG_SHA1.
1217 At the moment only the UHCI host controller is
1218 supported (PIP405, MIP405); define
1219 CONFIG_USB_UHCI to enable it.
1220 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1221 and define CONFIG_USB_STORAGE to enable the USB
1224 Supported are USB Keyboards and USB Floppy drives
1227 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1228 txfilltuning field in the EHCI controller on reset.
1230 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1231 HW module registers.
1234 Define the below if you wish to use the USB console.
1235 Once firmware is rebuilt from a serial console issue the
1236 command "setenv stdin usbtty; setenv stdout usbtty" and
1237 attach your USB cable. The Unix command "dmesg" should print
1238 it has found a new device. The environment variable usbtty
1239 can be set to gserial or cdc_acm to enable your device to
1240 appear to a USB host as a Linux gserial device or a
1241 Common Device Class Abstract Control Model serial device.
1242 If you select usbtty = gserial you should be able to enumerate
1244 # modprobe usbserial vendor=0xVendorID product=0xProductID
1245 else if using cdc_acm, simply setting the environment
1246 variable usbtty to be cdc_acm should suffice. The following
1247 might be defined in YourBoardName.h
1250 Define this to build a UDC device
1253 Define this to have a tty type of device available to
1254 talk to the UDC device
1257 Define this to enable the high speed support for usb
1258 device and usbtty. If this feature is enabled, a routine
1259 int is_usbd_high_speed(void)
1260 also needs to be defined by the driver to dynamically poll
1261 whether the enumeration has succeded at high speed or full
1264 CONFIG_SYS_CONSOLE_IS_IN_ENV
1265 Define this if you want stdin, stdout &/or stderr to
1268 If you have a USB-IF assigned VendorID then you may wish to
1269 define your own vendor specific values either in BoardName.h
1270 or directly in usbd_vendor_info.h. If you don't define
1271 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1272 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1273 should pretend to be a Linux device to it's target host.
1275 CONFIG_USBD_MANUFACTURER
1276 Define this string as the name of your company for
1277 - CONFIG_USBD_MANUFACTURER "my company"
1279 CONFIG_USBD_PRODUCT_NAME
1280 Define this string as the name of your product
1281 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1283 CONFIG_USBD_VENDORID
1284 Define this as your assigned Vendor ID from the USB
1285 Implementors Forum. This *must* be a genuine Vendor ID
1286 to avoid polluting the USB namespace.
1287 - CONFIG_USBD_VENDORID 0xFFFF
1289 CONFIG_USBD_PRODUCTID
1290 Define this as the unique Product ID
1292 - CONFIG_USBD_PRODUCTID 0xFFFF
1294 - ULPI Layer Support:
1295 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1296 the generic ULPI layer. The generic layer accesses the ULPI PHY
1297 via the platform viewport, so you need both the genric layer and
1298 the viewport enabled. Currently only Chipidea/ARC based
1299 viewport is supported.
1300 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1301 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1302 If your ULPI phy needs a different reference clock than the
1303 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1304 the appropriate value in Hz.
1307 The MMC controller on the Intel PXA is supported. To
1308 enable this define CONFIG_MMC. The MMC can be
1309 accessed from the boot prompt by mapping the device
1310 to physical memory similar to flash. Command line is
1311 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1312 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1315 Support for Renesas on-chip MMCIF controller
1317 CONFIG_SH_MMCIF_ADDR
1318 Define the base address of MMCIF registers
1321 Define the clock frequency for MMCIF
1323 CONFIG_SUPPORT_EMMC_BOOT
1324 Enable some additional features of the eMMC boot partitions.
1326 CONFIG_SUPPORT_EMMC_RPMB
1327 Enable the commands for reading, writing and programming the
1328 key for the Replay Protection Memory Block partition in eMMC.
1330 - USB Device Firmware Update (DFU) class support:
1331 CONFIG_USB_FUNCTION_DFU
1332 This enables the USB portion of the DFU USB class
1335 This enables the command "dfu" which is used to have
1336 U-Boot create a DFU class device via USB. This command
1337 requires that the "dfu_alt_info" environment variable be
1338 set and define the alt settings to expose to the host.
1341 This enables support for exposing (e)MMC devices via DFU.
1344 This enables support for exposing NAND devices via DFU.
1347 This enables support for exposing RAM via DFU.
1348 Note: DFU spec refer to non-volatile memory usage, but
1349 allow usages beyond the scope of spec - here RAM usage,
1350 one that would help mostly the developer.
1352 CONFIG_SYS_DFU_DATA_BUF_SIZE
1353 Dfu transfer uses a buffer before writing data to the
1354 raw storage device. Make the size (in bytes) of this buffer
1355 configurable. The size of this buffer is also configurable
1356 through the "dfu_bufsiz" environment variable.
1358 CONFIG_SYS_DFU_MAX_FILE_SIZE
1359 When updating files rather than the raw storage device,
1360 we use a static buffer to copy the file into and then write
1361 the buffer once we've been given the whole file. Define
1362 this to the maximum filesize (in bytes) for the buffer.
1363 Default is 4 MiB if undefined.
1365 DFU_DEFAULT_POLL_TIMEOUT
1366 Poll timeout [ms], is the timeout a device can send to the
1367 host. The host must wait for this timeout before sending
1368 a subsequent DFU_GET_STATUS request to the device.
1370 DFU_MANIFEST_POLL_TIMEOUT
1371 Poll timeout [ms], which the device sends to the host when
1372 entering dfuMANIFEST state. Host waits this timeout, before
1373 sending again an USB request to the device.
1375 - USB Device Android Fastboot support:
1376 CONFIG_USB_FUNCTION_FASTBOOT
1377 This enables the USB part of the fastboot gadget
1380 This enables the command "fastboot" which enables the Android
1381 fastboot mode for the platform's USB device. Fastboot is a USB
1382 protocol for downloading images, flashing and device control
1383 used on Android devices.
1384 See doc/README.android-fastboot for more information.
1386 CONFIG_ANDROID_BOOT_IMAGE
1387 This enables support for booting images which use the Android
1388 image format header.
1390 CONFIG_FASTBOOT_BUF_ADDR
1391 The fastboot protocol requires a large memory buffer for
1392 downloads. Define this to the starting RAM address to use for
1395 CONFIG_FASTBOOT_BUF_SIZE
1396 The fastboot protocol requires a large memory buffer for
1397 downloads. This buffer should be as large as possible for a
1398 platform. Define this to the size available RAM for fastboot.
1400 CONFIG_FASTBOOT_FLASH
1401 The fastboot protocol includes a "flash" command for writing
1402 the downloaded image to a non-volatile storage device. Define
1403 this to enable the "fastboot flash" command.
1405 CONFIG_FASTBOOT_FLASH_MMC_DEV
1406 The fastboot "flash" command requires additional information
1407 regarding the non-volatile storage device. Define this to
1408 the eMMC device that fastboot should use to store the image.
1410 CONFIG_FASTBOOT_GPT_NAME
1411 The fastboot "flash" command supports writing the downloaded
1412 image to the Protective MBR and the Primary GUID Partition
1413 Table. (Additionally, this downloaded image is post-processed
1414 to generate and write the Backup GUID Partition Table.)
1415 This occurs when the specified "partition name" on the
1416 "fastboot flash" command line matches this value.
1417 The default is "gpt" if undefined.
1419 CONFIG_FASTBOOT_MBR_NAME
1420 The fastboot "flash" command supports writing the downloaded
1422 This occurs when the "partition name" specified on the
1423 "fastboot flash" command line matches this value.
1424 If not defined the default value "mbr" is used.
1426 - Journaling Flash filesystem support:
1428 Define these for a default partition on a NAND device
1430 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1431 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1432 Define these for a default partition on a NOR device
1435 See Kconfig help for available keyboard drivers.
1439 Define this to enable a custom keyboard support.
1440 This simply calls drv_keyboard_init() which must be
1441 defined in your board-specific files. This option is deprecated
1442 and is only used by novena. For new boards, use driver model
1447 Enable the Freescale DIU video driver. Reference boards for
1448 SOCs that have a DIU should define this macro to enable DIU
1449 support, and should also define these other macros:
1454 CONFIG_VIDEO_SW_CURSOR
1455 CONFIG_VGA_AS_SINGLE_DEVICE
1457 CONFIG_VIDEO_BMP_LOGO
1459 The DIU driver will look for the 'video-mode' environment
1460 variable, and if defined, enable the DIU as a console during
1461 boot. See the documentation file doc/README.video for a
1462 description of this variable.
1464 - LCD Support: CONFIG_LCD
1466 Define this to enable LCD support (for output to LCD
1467 display); also select one of the supported displays
1468 by defining one of these:
1472 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1474 CONFIG_NEC_NL6448AC33:
1476 NEC NL6448AC33-18. Active, color, single scan.
1478 CONFIG_NEC_NL6448BC20
1480 NEC NL6448BC20-08. 6.5", 640x480.
1481 Active, color, single scan.
1483 CONFIG_NEC_NL6448BC33_54
1485 NEC NL6448BC33-54. 10.4", 640x480.
1486 Active, color, single scan.
1490 Sharp 320x240. Active, color, single scan.
1491 It isn't 16x9, and I am not sure what it is.
1493 CONFIG_SHARP_LQ64D341
1495 Sharp LQ64D341 display, 640x480.
1496 Active, color, single scan.
1500 HLD1045 display, 640x480.
1501 Active, color, single scan.
1505 Optrex CBL50840-2 NF-FW 99 22 M5
1507 Hitachi LMG6912RPFC-00T
1511 320x240. Black & white.
1513 CONFIG_LCD_ALIGNMENT
1515 Normally the LCD is page-aligned (typically 4KB). If this is
1516 defined then the LCD will be aligned to this value instead.
1517 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1518 here, since it is cheaper to change data cache settings on
1519 a per-section basis.
1524 Sometimes, for example if the display is mounted in portrait
1525 mode or even if it's mounted landscape but rotated by 180degree,
1526 we need to rotate our content of the display relative to the
1527 framebuffer, so that user can read the messages which are
1529 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1530 initialized with a given rotation from "vl_rot" out of
1531 "vidinfo_t" which is provided by the board specific code.
1532 The value for vl_rot is coded as following (matching to
1533 fbcon=rotate:<n> linux-kernel commandline):
1534 0 = no rotation respectively 0 degree
1535 1 = 90 degree rotation
1536 2 = 180 degree rotation
1537 3 = 270 degree rotation
1539 If CONFIG_LCD_ROTATION is not defined, the console will be
1540 initialized with 0degree rotation.
1544 Support drawing of RLE8-compressed bitmaps on the LCD.
1548 Enables an 'i2c edid' command which can read EDID
1549 information over I2C from an attached LCD display.
1551 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1553 If this option is set, the environment is checked for
1554 a variable "splashimage". If found, the usual display
1555 of logo, copyright and system information on the LCD
1556 is suppressed and the BMP image at the address
1557 specified in "splashimage" is loaded instead. The
1558 console is redirected to the "nulldev", too. This
1559 allows for a "silent" boot where a splash screen is
1560 loaded very quickly after power-on.
1562 CONFIG_SPLASHIMAGE_GUARD
1564 If this option is set, then U-Boot will prevent the environment
1565 variable "splashimage" from being set to a problematic address
1566 (see doc/README.displaying-bmps).
1567 This option is useful for targets where, due to alignment
1568 restrictions, an improperly aligned BMP image will cause a data
1569 abort. If you think you will not have problems with unaligned
1570 accesses (for example because your toolchain prevents them)
1571 there is no need to set this option.
1573 CONFIG_SPLASH_SCREEN_ALIGN
1575 If this option is set the splash image can be freely positioned
1576 on the screen. Environment variable "splashpos" specifies the
1577 position as "x,y". If a positive number is given it is used as
1578 number of pixel from left/top. If a negative number is given it
1579 is used as number of pixel from right/bottom. You can also
1580 specify 'm' for centering the image.
1583 setenv splashpos m,m
1584 => image at center of screen
1586 setenv splashpos 30,20
1587 => image at x = 30 and y = 20
1589 setenv splashpos -10,m
1590 => vertically centered image
1591 at x = dspWidth - bmpWidth - 9
1593 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1595 If this option is set, additionally to standard BMP
1596 images, gzipped BMP images can be displayed via the
1597 splashscreen support or the bmp command.
1599 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1601 If this option is set, 8-bit RLE compressed BMP images
1602 can be displayed via the splashscreen support or the
1605 - Compression support:
1608 Enabled by default to support gzip compressed images.
1612 If this option is set, support for bzip2 compressed
1613 images is included. If not, only uncompressed and gzip
1614 compressed images are supported.
1616 NOTE: the bzip2 algorithm requires a lot of RAM, so
1617 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1623 The address of PHY on MII bus.
1625 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1627 The clock frequency of the MII bus
1629 CONFIG_PHY_RESET_DELAY
1631 Some PHY like Intel LXT971A need extra delay after
1632 reset before any MII register access is possible.
1633 For such PHY, set this option to the usec delay
1634 required. (minimum 300usec for LXT971A)
1636 CONFIG_PHY_CMD_DELAY (ppc4xx)
1638 Some PHY like Intel LXT971A need extra delay after
1639 command issued before MII status register can be read
1644 Define a default value for the IP address to use for
1645 the default Ethernet interface, in case this is not
1646 determined through e.g. bootp.
1647 (Environment variable "ipaddr")
1649 - Server IP address:
1652 Defines a default value for the IP address of a TFTP
1653 server to contact when using the "tftboot" command.
1654 (Environment variable "serverip")
1656 CONFIG_KEEP_SERVERADDR
1658 Keeps the server's MAC address, in the env 'serveraddr'
1659 for passing to bootargs (like Linux's netconsole option)
1661 - Gateway IP address:
1664 Defines a default value for the IP address of the
1665 default router where packets to other networks are
1667 (Environment variable "gatewayip")
1672 Defines a default value for the subnet mask (or
1673 routing prefix) which is used to determine if an IP
1674 address belongs to the local subnet or needs to be
1675 forwarded through a router.
1676 (Environment variable "netmask")
1678 - Multicast TFTP Mode:
1681 Defines whether you want to support multicast TFTP as per
1682 rfc-2090; for example to work with atftp. Lets lots of targets
1683 tftp down the same boot image concurrently. Note: the Ethernet
1684 driver in use must provide a function: mcast() to join/leave a
1687 - BOOTP Recovery Mode:
1688 CONFIG_BOOTP_RANDOM_DELAY
1690 If you have many targets in a network that try to
1691 boot using BOOTP, you may want to avoid that all
1692 systems send out BOOTP requests at precisely the same
1693 moment (which would happen for instance at recovery
1694 from a power failure, when all systems will try to
1695 boot, thus flooding the BOOTP server. Defining
1696 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1697 inserted before sending out BOOTP requests. The
1698 following delays are inserted then:
1700 1st BOOTP request: delay 0 ... 1 sec
1701 2nd BOOTP request: delay 0 ... 2 sec
1702 3rd BOOTP request: delay 0 ... 4 sec
1704 BOOTP requests: delay 0 ... 8 sec
1706 CONFIG_BOOTP_ID_CACHE_SIZE
1708 BOOTP packets are uniquely identified using a 32-bit ID. The
1709 server will copy the ID from client requests to responses and
1710 U-Boot will use this to determine if it is the destination of
1711 an incoming response. Some servers will check that addresses
1712 aren't in use before handing them out (usually using an ARP
1713 ping) and therefore take up to a few hundred milliseconds to
1714 respond. Network congestion may also influence the time it
1715 takes for a response to make it back to the client. If that
1716 time is too long, U-Boot will retransmit requests. In order
1717 to allow earlier responses to still be accepted after these
1718 retransmissions, U-Boot's BOOTP client keeps a small cache of
1719 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1720 cache. The default is to keep IDs for up to four outstanding
1721 requests. Increasing this will allow U-Boot to accept offers
1722 from a BOOTP client in networks with unusually high latency.
1724 - DHCP Advanced Options:
1725 You can fine tune the DHCP functionality by defining
1726 CONFIG_BOOTP_* symbols:
1728 CONFIG_BOOTP_SUBNETMASK
1729 CONFIG_BOOTP_GATEWAY
1730 CONFIG_BOOTP_HOSTNAME
1731 CONFIG_BOOTP_NISDOMAIN
1732 CONFIG_BOOTP_BOOTPATH
1733 CONFIG_BOOTP_BOOTFILESIZE
1736 CONFIG_BOOTP_SEND_HOSTNAME
1737 CONFIG_BOOTP_NTPSERVER
1738 CONFIG_BOOTP_TIMEOFFSET
1739 CONFIG_BOOTP_VENDOREX
1740 CONFIG_BOOTP_MAY_FAIL
1742 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1743 environment variable, not the BOOTP server.
1745 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1746 after the configured retry count, the call will fail
1747 instead of starting over. This can be used to fail over
1748 to Link-local IP address configuration if the DHCP server
1751 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1752 serverip from a DHCP server, it is possible that more
1753 than one DNS serverip is offered to the client.
1754 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1755 serverip will be stored in the additional environment
1756 variable "dnsip2". The first DNS serverip is always
1757 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1760 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1761 to do a dynamic update of a DNS server. To do this, they
1762 need the hostname of the DHCP requester.
1763 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1764 of the "hostname" environment variable is passed as
1765 option 12 to the DHCP server.
1767 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1769 A 32bit value in microseconds for a delay between
1770 receiving a "DHCP Offer" and sending the "DHCP Request".
1771 This fixes a problem with certain DHCP servers that don't
1772 respond 100% of the time to a "DHCP request". E.g. On an
1773 AT91RM9200 processor running at 180MHz, this delay needed
1774 to be *at least* 15,000 usec before a Windows Server 2003
1775 DHCP server would reply 100% of the time. I recommend at
1776 least 50,000 usec to be safe. The alternative is to hope
1777 that one of the retries will be successful but note that
1778 the DHCP timeout and retry process takes a longer than
1781 - Link-local IP address negotiation:
1782 Negotiate with other link-local clients on the local network
1783 for an address that doesn't require explicit configuration.
1784 This is especially useful if a DHCP server cannot be guaranteed
1785 to exist in all environments that the device must operate.
1787 See doc/README.link-local for more information.
1790 CONFIG_CDP_DEVICE_ID
1792 The device id used in CDP trigger frames.
1794 CONFIG_CDP_DEVICE_ID_PREFIX
1796 A two character string which is prefixed to the MAC address
1801 A printf format string which contains the ascii name of
1802 the port. Normally is set to "eth%d" which sets
1803 eth0 for the first Ethernet, eth1 for the second etc.
1805 CONFIG_CDP_CAPABILITIES
1807 A 32bit integer which indicates the device capabilities;
1808 0x00000010 for a normal host which does not forwards.
1812 An ascii string containing the version of the software.
1816 An ascii string containing the name of the platform.
1820 A 32bit integer sent on the trigger.
1822 CONFIG_CDP_POWER_CONSUMPTION
1824 A 16bit integer containing the power consumption of the
1825 device in .1 of milliwatts.
1827 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1829 A byte containing the id of the VLAN.
1831 - Status LED: CONFIG_LED_STATUS
1833 Several configurations allow to display the current
1834 status using a LED. For instance, the LED will blink
1835 fast while running U-Boot code, stop blinking as
1836 soon as a reply to a BOOTP request was received, and
1837 start blinking slow once the Linux kernel is running
1838 (supported by a status LED driver in the Linux
1839 kernel). Defining CONFIG_LED_STATUS enables this
1844 CONFIG_LED_STATUS_GPIO
1845 The status LED can be connected to a GPIO pin.
1846 In such cases, the gpio_led driver can be used as a
1847 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1848 to include the gpio_led driver in the U-Boot binary.
1850 CONFIG_GPIO_LED_INVERTED_TABLE
1851 Some GPIO connected LEDs may have inverted polarity in which
1852 case the GPIO high value corresponds to LED off state and
1853 GPIO low value corresponds to LED on state.
1854 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1855 with a list of GPIO LEDs that have inverted polarity.
1857 - I2C Support: CONFIG_SYS_I2C
1859 This enable the NEW i2c subsystem, and will allow you to use
1860 i2c commands at the u-boot command line (as long as you set
1861 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1862 based realtime clock chips or other i2c devices. See
1863 common/cmd_i2c.c for a description of the command line
1866 ported i2c driver to the new framework:
1867 - drivers/i2c/soft_i2c.c:
1868 - activate first bus with CONFIG_SYS_I2C_SOFT define
1869 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1870 for defining speed and slave address
1871 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1872 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1873 for defining speed and slave address
1874 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1875 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1876 for defining speed and slave address
1877 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1878 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1879 for defining speed and slave address
1881 - drivers/i2c/fsl_i2c.c:
1882 - activate i2c driver with CONFIG_SYS_I2C_FSL
1883 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1884 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1885 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1887 - If your board supports a second fsl i2c bus, define
1888 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1889 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1890 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1893 - drivers/i2c/tegra_i2c.c:
1894 - activate this driver with CONFIG_SYS_I2C_TEGRA
1895 - This driver adds 4 i2c buses with a fix speed from
1896 100000 and the slave addr 0!
1898 - drivers/i2c/ppc4xx_i2c.c
1899 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1900 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1901 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1903 - drivers/i2c/i2c_mxc.c
1904 - activate this driver with CONFIG_SYS_I2C_MXC
1905 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1906 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1907 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1908 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1909 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1910 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1911 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1912 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1913 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1914 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1915 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1916 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1917 If those defines are not set, default value is 100000
1918 for speed, and 0 for slave.
1920 - drivers/i2c/rcar_i2c.c:
1921 - activate this driver with CONFIG_SYS_I2C_RCAR
1922 - This driver adds 4 i2c buses
1924 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1925 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1926 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1927 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1928 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1929 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1930 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1931 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1932 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1934 - drivers/i2c/sh_i2c.c:
1935 - activate this driver with CONFIG_SYS_I2C_SH
1936 - This driver adds from 2 to 5 i2c buses
1938 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1939 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1940 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1941 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1942 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1943 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1944 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1945 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1946 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1947 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1948 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1950 - drivers/i2c/omap24xx_i2c.c
1951 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1952 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1953 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1954 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1955 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1956 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1957 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1958 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1959 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1960 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1961 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1963 - drivers/i2c/zynq_i2c.c
1964 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1965 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1966 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1968 - drivers/i2c/s3c24x0_i2c.c:
1969 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1970 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1971 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1972 with a fix speed from 100000 and the slave addr 0!
1974 - drivers/i2c/ihs_i2c.c
1975 - activate this driver with CONFIG_SYS_I2C_IHS
1976 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1977 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1978 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1979 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1980 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1981 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1982 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1983 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1984 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1985 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1986 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1987 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
1988 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1989 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1990 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1991 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1992 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1993 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1994 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1995 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1996 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2000 CONFIG_SYS_NUM_I2C_BUSES
2001 Hold the number of i2c buses you want to use.
2003 CONFIG_SYS_I2C_DIRECT_BUS
2004 define this, if you don't use i2c muxes on your hardware.
2005 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2008 CONFIG_SYS_I2C_MAX_HOPS
2009 define how many muxes are maximal consecutively connected
2010 on one i2c bus. If you not use i2c muxes, omit this
2013 CONFIG_SYS_I2C_BUSES
2014 hold a list of buses you want to use, only used if
2015 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2016 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2017 CONFIG_SYS_NUM_I2C_BUSES = 9:
2019 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2020 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2021 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2022 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2023 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2024 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2025 {1, {I2C_NULL_HOP}}, \
2026 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2027 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2031 bus 0 on adapter 0 without a mux
2032 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2033 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2034 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2035 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2036 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2037 bus 6 on adapter 1 without a mux
2038 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2039 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2041 If you do not have i2c muxes on your board, omit this define.
2043 - Legacy I2C Support:
2044 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2045 then the following macros need to be defined (examples are
2046 from include/configs/lwmon.h):
2050 (Optional). Any commands necessary to enable the I2C
2051 controller or configure ports.
2053 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2057 The code necessary to make the I2C data line active
2058 (driven). If the data line is open collector, this
2061 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2065 The code necessary to make the I2C data line tri-stated
2066 (inactive). If the data line is open collector, this
2069 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2073 Code that returns true if the I2C data line is high,
2076 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2080 If <bit> is true, sets the I2C data line high. If it
2081 is false, it clears it (low).
2083 eg: #define I2C_SDA(bit) \
2084 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2085 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2089 If <bit> is true, sets the I2C clock line high. If it
2090 is false, it clears it (low).
2092 eg: #define I2C_SCL(bit) \
2093 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2094 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2098 This delay is invoked four times per clock cycle so this
2099 controls the rate of data transfer. The data rate thus
2100 is 1 / (I2C_DELAY * 4). Often defined to be something
2103 #define I2C_DELAY udelay(2)
2105 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2107 If your arch supports the generic GPIO framework (asm/gpio.h),
2108 then you may alternatively define the two GPIOs that are to be
2109 used as SCL / SDA. Any of the previous I2C_xxx macros will
2110 have GPIO-based defaults assigned to them as appropriate.
2112 You should define these to the GPIO value as given directly to
2113 the generic GPIO functions.
2115 CONFIG_SYS_I2C_INIT_BOARD
2117 When a board is reset during an i2c bus transfer
2118 chips might think that the current transfer is still
2119 in progress. On some boards it is possible to access
2120 the i2c SCLK line directly, either by using the
2121 processor pin as a GPIO or by having a second pin
2122 connected to the bus. If this option is defined a
2123 custom i2c_init_board() routine in boards/xxx/board.c
2124 is run early in the boot sequence.
2126 CONFIG_I2C_MULTI_BUS
2128 This option allows the use of multiple I2C buses, each of which
2129 must have a controller. At any point in time, only one bus is
2130 active. To switch to a different bus, use the 'i2c dev' command.
2131 Note that bus numbering is zero-based.
2133 CONFIG_SYS_I2C_NOPROBES
2135 This option specifies a list of I2C devices that will be skipped
2136 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2137 is set, specify a list of bus-device pairs. Otherwise, specify
2138 a 1D array of device addresses
2141 #undef CONFIG_I2C_MULTI_BUS
2142 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2144 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2146 #define CONFIG_I2C_MULTI_BUS
2147 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2149 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2151 CONFIG_SYS_SPD_BUS_NUM
2153 If defined, then this indicates the I2C bus number for DDR SPD.
2154 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2156 CONFIG_SYS_RTC_BUS_NUM
2158 If defined, then this indicates the I2C bus number for the RTC.
2159 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2161 CONFIG_SOFT_I2C_READ_REPEATED_START
2163 defining this will force the i2c_read() function in
2164 the soft_i2c driver to perform an I2C repeated start
2165 between writing the address pointer and reading the
2166 data. If this define is omitted the default behaviour
2167 of doing a stop-start sequence will be used. Most I2C
2168 devices can use either method, but some require one or
2171 - SPI Support: CONFIG_SPI
2173 Enables SPI driver (so far only tested with
2174 SPI EEPROM, also an instance works with Crystal A/D and
2175 D/As on the SACSng board)
2179 Enables the driver for SPI controller on SuperH. Currently
2180 only SH7757 is supported.
2184 Enables a software (bit-bang) SPI driver rather than
2185 using hardware support. This is a general purpose
2186 driver that only requires three general I/O port pins
2187 (two outputs, one input) to function. If this is
2188 defined, the board configuration must define several
2189 SPI configuration items (port pins to use, etc). For
2190 an example, see include/configs/sacsng.h.
2194 Enables a hardware SPI driver for general-purpose reads
2195 and writes. As with CONFIG_SOFT_SPI, the board configuration
2196 must define a list of chip-select function pointers.
2197 Currently supported on some MPC8xxx processors. For an
2198 example, see include/configs/mpc8349emds.h.
2202 Enables the driver for the SPI controllers on i.MX and MXC
2203 SoCs. Currently i.MX31/35/51 are supported.
2205 CONFIG_SYS_SPI_MXC_WAIT
2206 Timeout for waiting until spi transfer completed.
2207 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2209 - FPGA Support: CONFIG_FPGA
2211 Enables FPGA subsystem.
2213 CONFIG_FPGA_<vendor>
2215 Enables support for specific chip vendors.
2218 CONFIG_FPGA_<family>
2220 Enables support for FPGA family.
2221 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2225 Specify the number of FPGA devices to support.
2227 CONFIG_SYS_FPGA_PROG_FEEDBACK
2229 Enable printing of hash marks during FPGA configuration.
2231 CONFIG_SYS_FPGA_CHECK_BUSY
2233 Enable checks on FPGA configuration interface busy
2234 status by the configuration function. This option
2235 will require a board or device specific function to
2240 If defined, a function that provides delays in the FPGA
2241 configuration driver.
2243 CONFIG_SYS_FPGA_CHECK_CTRLC
2244 Allow Control-C to interrupt FPGA configuration
2246 CONFIG_SYS_FPGA_CHECK_ERROR
2248 Check for configuration errors during FPGA bitfile
2249 loading. For example, abort during Virtex II
2250 configuration if the INIT_B line goes low (which
2251 indicated a CRC error).
2253 CONFIG_SYS_FPGA_WAIT_INIT
2255 Maximum time to wait for the INIT_B line to de-assert
2256 after PROB_B has been de-asserted during a Virtex II
2257 FPGA configuration sequence. The default time is 500
2260 CONFIG_SYS_FPGA_WAIT_BUSY
2262 Maximum time to wait for BUSY to de-assert during
2263 Virtex II FPGA configuration. The default is 5 ms.
2265 CONFIG_SYS_FPGA_WAIT_CONFIG
2267 Time to wait after FPGA configuration. The default is
2270 - Configuration Management:
2273 Some SoCs need special image types (e.g. U-Boot binary
2274 with a special header) as build targets. By defining
2275 CONFIG_BUILD_TARGET in the SoC / board header, this
2276 special image will be automatically built upon calling
2281 If defined, this string will be added to the U-Boot
2282 version information (U_BOOT_VERSION)
2284 - Vendor Parameter Protection:
2286 U-Boot considers the values of the environment
2287 variables "serial#" (Board Serial Number) and
2288 "ethaddr" (Ethernet Address) to be parameters that
2289 are set once by the board vendor / manufacturer, and
2290 protects these variables from casual modification by
2291 the user. Once set, these variables are read-only,
2292 and write or delete attempts are rejected. You can
2293 change this behaviour:
2295 If CONFIG_ENV_OVERWRITE is #defined in your config
2296 file, the write protection for vendor parameters is
2297 completely disabled. Anybody can change or delete
2300 Alternatively, if you define _both_ an ethaddr in the
2301 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2302 Ethernet address is installed in the environment,
2303 which can be changed exactly ONCE by the user. [The
2304 serial# is unaffected by this, i. e. it remains
2307 The same can be accomplished in a more flexible way
2308 for any variable by configuring the type of access
2309 to allow for those variables in the ".flags" variable
2310 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2315 Define this variable to enable the reservation of
2316 "protected RAM", i. e. RAM which is not overwritten
2317 by U-Boot. Define CONFIG_PRAM to hold the number of
2318 kB you want to reserve for pRAM. You can overwrite
2319 this default value by defining an environment
2320 variable "pram" to the number of kB you want to
2321 reserve. Note that the board info structure will
2322 still show the full amount of RAM. If pRAM is
2323 reserved, a new environment variable "mem" will
2324 automatically be defined to hold the amount of
2325 remaining RAM in a form that can be passed as boot
2326 argument to Linux, for instance like that:
2328 setenv bootargs ... mem=\${mem}
2331 This way you can tell Linux not to use this memory,
2332 either, which results in a memory region that will
2333 not be affected by reboots.
2335 *WARNING* If your board configuration uses automatic
2336 detection of the RAM size, you must make sure that
2337 this memory test is non-destructive. So far, the
2338 following board configurations are known to be
2341 IVMS8, IVML24, SPD8xx,
2342 HERMES, IP860, RPXlite, LWMON,
2345 - Access to physical memory region (> 4GB)
2346 Some basic support is provided for operations on memory not
2347 normally accessible to U-Boot - e.g. some architectures
2348 support access to more than 4GB of memory on 32-bit
2349 machines using physical address extension or similar.
2350 Define CONFIG_PHYSMEM to access this basic support, which
2351 currently only supports clearing the memory.
2356 Define this variable to stop the system in case of a
2357 fatal error, so that you have to reset it manually.
2358 This is probably NOT a good idea for an embedded
2359 system where you want the system to reboot
2360 automatically as fast as possible, but it may be
2361 useful during development since you can try to debug
2362 the conditions that lead to the situation.
2364 CONFIG_NET_RETRY_COUNT
2366 This variable defines the number of retries for
2367 network operations like ARP, RARP, TFTP, or BOOTP
2368 before giving up the operation. If not defined, a
2369 default value of 5 is used.
2373 Timeout waiting for an ARP reply in milliseconds.
2377 Timeout in milliseconds used in NFS protocol.
2378 If you encounter "ERROR: Cannot umount" in nfs command,
2379 try longer timeout such as
2380 #define CONFIG_NFS_TIMEOUT 10000UL
2382 - Command Interpreter:
2383 CONFIG_AUTO_COMPLETE
2385 Enable auto completion of commands using TAB.
2387 CONFIG_SYS_PROMPT_HUSH_PS2
2389 This defines the secondary prompt string, which is
2390 printed when the command interpreter needs more input
2391 to complete a command. Usually "> ".
2395 In the current implementation, the local variables
2396 space and global environment variables space are
2397 separated. Local variables are those you define by
2398 simply typing `name=value'. To access a local
2399 variable later on, you have write `$name' or
2400 `${name}'; to execute the contents of a variable
2401 directly type `$name' at the command prompt.
2403 Global environment variables are those you use
2404 setenv/printenv to work with. To run a command stored
2405 in such a variable, you need to use the run command,
2406 and you must not use the '$' sign to access them.
2408 To store commands and special characters in a
2409 variable, please use double quotation marks
2410 surrounding the whole text of the variable, instead
2411 of the backslashes before semicolons and special
2414 - Command Line Editing and History:
2415 CONFIG_CMDLINE_EDITING
2417 Enable editing and History functions for interactive
2418 command line input operations
2420 - Command Line PS1/PS2 support:
2421 CONFIG_CMDLINE_PS_SUPPORT
2423 Enable support for changing the command prompt string
2424 at run-time. Only static string is supported so far.
2425 The string is obtained from environment variables PS1
2428 - Default Environment:
2429 CONFIG_EXTRA_ENV_SETTINGS
2431 Define this to contain any number of null terminated
2432 strings (variable = value pairs) that will be part of
2433 the default environment compiled into the boot image.
2435 For example, place something like this in your
2436 board's config file:
2438 #define CONFIG_EXTRA_ENV_SETTINGS \
2442 Warning: This method is based on knowledge about the
2443 internal format how the environment is stored by the
2444 U-Boot code. This is NOT an official, exported
2445 interface! Although it is unlikely that this format
2446 will change soon, there is no guarantee either.
2447 You better know what you are doing here.
2449 Note: overly (ab)use of the default environment is
2450 discouraged. Make sure to check other ways to preset
2451 the environment like the "source" command or the
2454 CONFIG_ENV_VARS_UBOOT_CONFIG
2456 Define this in order to add variables describing the
2457 U-Boot build configuration to the default environment.
2458 These will be named arch, cpu, board, vendor, and soc.
2460 Enabling this option will cause the following to be defined:
2468 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2470 Define this in order to add variables describing certain
2471 run-time determined information about the hardware to the
2472 environment. These will be named board_name, board_rev.
2474 CONFIG_DELAY_ENVIRONMENT
2476 Normally the environment is loaded when the board is
2477 initialised so that it is available to U-Boot. This inhibits
2478 that so that the environment is not available until
2479 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2480 this is instead controlled by the value of
2481 /config/load-environment.
2483 - DataFlash Support:
2484 CONFIG_HAS_DATAFLASH
2486 Defining this option enables DataFlash features and
2487 allows to read/write in Dataflash via the standard
2490 - Serial Flash support
2493 Defining this option enables SPI flash commands
2494 'sf probe/read/write/erase/update'.
2496 Usage requires an initial 'probe' to define the serial
2497 flash parameters, followed by read/write/erase/update
2500 The following defaults may be provided by the platform
2501 to handle the common case when only a single serial
2502 flash is present on the system.
2504 CONFIG_SF_DEFAULT_BUS Bus identifier
2505 CONFIG_SF_DEFAULT_CS Chip-select
2506 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2507 CONFIG_SF_DEFAULT_SPEED in Hz
2511 Define this option to include a destructive SPI flash
2514 - SystemACE Support:
2517 Adding this option adds support for Xilinx SystemACE
2518 chips attached via some sort of local bus. The address
2519 of the chip must also be defined in the
2520 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2522 #define CONFIG_SYSTEMACE
2523 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2525 When SystemACE support is added, the "ace" device type
2526 becomes available to the fat commands, i.e. fatls.
2528 - TFTP Fixed UDP Port:
2531 If this is defined, the environment variable tftpsrcp
2532 is used to supply the TFTP UDP source port value.
2533 If tftpsrcp isn't defined, the normal pseudo-random port
2534 number generator is used.
2536 Also, the environment variable tftpdstp is used to supply
2537 the TFTP UDP destination port value. If tftpdstp isn't
2538 defined, the normal port 69 is used.
2540 The purpose for tftpsrcp is to allow a TFTP server to
2541 blindly start the TFTP transfer using the pre-configured
2542 target IP address and UDP port. This has the effect of
2543 "punching through" the (Windows XP) firewall, allowing
2544 the remainder of the TFTP transfer to proceed normally.
2545 A better solution is to properly configure the firewall,
2546 but sometimes that is not allowed.
2548 - bootcount support:
2549 CONFIG_BOOTCOUNT_LIMIT
2551 This enables the bootcounter support, see:
2552 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2555 enable special bootcounter support on at91sam9xe based boards.
2557 enable special bootcounter support on da850 based boards.
2558 CONFIG_BOOTCOUNT_RAM
2559 enable support for the bootcounter in RAM
2560 CONFIG_BOOTCOUNT_I2C
2561 enable support for the bootcounter on an i2c (like RTC) device.
2562 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2563 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2565 CONFIG_BOOTCOUNT_ALEN = address len
2567 - Show boot progress:
2568 CONFIG_SHOW_BOOT_PROGRESS
2570 Defining this option allows to add some board-
2571 specific code (calling a user-provided function
2572 "show_boot_progress(int)") that enables you to show
2573 the system's boot progress on some display (for
2574 example, some LED's) on your board. At the moment,
2575 the following checkpoints are implemented:
2578 Legacy uImage format:
2581 1 common/cmd_bootm.c before attempting to boot an image
2582 -1 common/cmd_bootm.c Image header has bad magic number
2583 2 common/cmd_bootm.c Image header has correct magic number
2584 -2 common/cmd_bootm.c Image header has bad checksum
2585 3 common/cmd_bootm.c Image header has correct checksum
2586 -3 common/cmd_bootm.c Image data has bad checksum
2587 4 common/cmd_bootm.c Image data has correct checksum
2588 -4 common/cmd_bootm.c Image is for unsupported architecture
2589 5 common/cmd_bootm.c Architecture check OK
2590 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2591 6 common/cmd_bootm.c Image Type check OK
2592 -6 common/cmd_bootm.c gunzip uncompression error
2593 -7 common/cmd_bootm.c Unimplemented compression type
2594 7 common/cmd_bootm.c Uncompression OK
2595 8 common/cmd_bootm.c No uncompress/copy overwrite error
2596 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2598 9 common/image.c Start initial ramdisk verification
2599 -10 common/image.c Ramdisk header has bad magic number
2600 -11 common/image.c Ramdisk header has bad checksum
2601 10 common/image.c Ramdisk header is OK
2602 -12 common/image.c Ramdisk data has bad checksum
2603 11 common/image.c Ramdisk data has correct checksum
2604 12 common/image.c Ramdisk verification complete, start loading
2605 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2606 13 common/image.c Start multifile image verification
2607 14 common/image.c No initial ramdisk, no multifile, continue.
2609 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2611 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2612 -31 post/post.c POST test failed, detected by post_output_backlog()
2613 -32 post/post.c POST test failed, detected by post_run_single()
2615 34 common/cmd_doc.c before loading a Image from a DOC device
2616 -35 common/cmd_doc.c Bad usage of "doc" command
2617 35 common/cmd_doc.c correct usage of "doc" command
2618 -36 common/cmd_doc.c No boot device
2619 36 common/cmd_doc.c correct boot device
2620 -37 common/cmd_doc.c Unknown Chip ID on boot device
2621 37 common/cmd_doc.c correct chip ID found, device available
2622 -38 common/cmd_doc.c Read Error on boot device
2623 38 common/cmd_doc.c reading Image header from DOC device OK
2624 -39 common/cmd_doc.c Image header has bad magic number
2625 39 common/cmd_doc.c Image header has correct magic number
2626 -40 common/cmd_doc.c Error reading Image from DOC device
2627 40 common/cmd_doc.c Image header has correct magic number
2628 41 common/cmd_ide.c before loading a Image from a IDE device
2629 -42 common/cmd_ide.c Bad usage of "ide" command
2630 42 common/cmd_ide.c correct usage of "ide" command
2631 -43 common/cmd_ide.c No boot device
2632 43 common/cmd_ide.c boot device found
2633 -44 common/cmd_ide.c Device not available
2634 44 common/cmd_ide.c Device available
2635 -45 common/cmd_ide.c wrong partition selected
2636 45 common/cmd_ide.c partition selected
2637 -46 common/cmd_ide.c Unknown partition table
2638 46 common/cmd_ide.c valid partition table found
2639 -47 common/cmd_ide.c Invalid partition type
2640 47 common/cmd_ide.c correct partition type
2641 -48 common/cmd_ide.c Error reading Image Header on boot device
2642 48 common/cmd_ide.c reading Image Header from IDE device OK
2643 -49 common/cmd_ide.c Image header has bad magic number
2644 49 common/cmd_ide.c Image header has correct magic number
2645 -50 common/cmd_ide.c Image header has bad checksum
2646 50 common/cmd_ide.c Image header has correct checksum
2647 -51 common/cmd_ide.c Error reading Image from IDE device
2648 51 common/cmd_ide.c reading Image from IDE device OK
2649 52 common/cmd_nand.c before loading a Image from a NAND device
2650 -53 common/cmd_nand.c Bad usage of "nand" command
2651 53 common/cmd_nand.c correct usage of "nand" command
2652 -54 common/cmd_nand.c No boot device
2653 54 common/cmd_nand.c boot device found
2654 -55 common/cmd_nand.c Unknown Chip ID on boot device
2655 55 common/cmd_nand.c correct chip ID found, device available
2656 -56 common/cmd_nand.c Error reading Image Header on boot device
2657 56 common/cmd_nand.c reading Image Header from NAND device OK
2658 -57 common/cmd_nand.c Image header has bad magic number
2659 57 common/cmd_nand.c Image header has correct magic number
2660 -58 common/cmd_nand.c Error reading Image from NAND device
2661 58 common/cmd_nand.c reading Image from NAND device OK
2663 -60 common/env_common.c Environment has a bad CRC, using default
2665 64 net/eth.c starting with Ethernet configuration.
2666 -64 net/eth.c no Ethernet found.
2667 65 net/eth.c Ethernet found.
2669 -80 common/cmd_net.c usage wrong
2670 80 common/cmd_net.c before calling net_loop()
2671 -81 common/cmd_net.c some error in net_loop() occurred
2672 81 common/cmd_net.c net_loop() back without error
2673 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2674 82 common/cmd_net.c trying automatic boot
2675 83 common/cmd_net.c running "source" command
2676 -83 common/cmd_net.c some error in automatic boot or "source" command
2677 84 common/cmd_net.c end without errors
2682 100 common/cmd_bootm.c Kernel FIT Image has correct format
2683 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2684 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2685 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2686 102 common/cmd_bootm.c Kernel unit name specified
2687 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2688 103 common/cmd_bootm.c Found configuration node
2689 104 common/cmd_bootm.c Got kernel subimage node offset
2690 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2691 105 common/cmd_bootm.c Kernel subimage hash verification OK
2692 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2693 106 common/cmd_bootm.c Architecture check OK
2694 -106 common/cmd_bootm.c Kernel subimage has wrong type
2695 107 common/cmd_bootm.c Kernel subimage type OK
2696 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2697 108 common/cmd_bootm.c Got kernel subimage data/size
2698 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2699 -109 common/cmd_bootm.c Can't get kernel subimage type
2700 -110 common/cmd_bootm.c Can't get kernel subimage comp
2701 -111 common/cmd_bootm.c Can't get kernel subimage os
2702 -112 common/cmd_bootm.c Can't get kernel subimage load address
2703 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2705 120 common/image.c Start initial ramdisk verification
2706 -120 common/image.c Ramdisk FIT image has incorrect format
2707 121 common/image.c Ramdisk FIT image has correct format
2708 122 common/image.c No ramdisk subimage unit name, using configuration
2709 -122 common/image.c Can't get configuration for ramdisk subimage
2710 123 common/image.c Ramdisk unit name specified
2711 -124 common/image.c Can't get ramdisk subimage node offset
2712 125 common/image.c Got ramdisk subimage node offset
2713 -125 common/image.c Ramdisk subimage hash verification failed
2714 126 common/image.c Ramdisk subimage hash verification OK
2715 -126 common/image.c Ramdisk subimage for unsupported architecture
2716 127 common/image.c Architecture check OK
2717 -127 common/image.c Can't get ramdisk subimage data/size
2718 128 common/image.c Got ramdisk subimage data/size
2719 129 common/image.c Can't get ramdisk load address
2720 -129 common/image.c Got ramdisk load address
2722 -130 common/cmd_doc.c Incorrect FIT image format
2723 131 common/cmd_doc.c FIT image format OK
2725 -140 common/cmd_ide.c Incorrect FIT image format
2726 141 common/cmd_ide.c FIT image format OK
2728 -150 common/cmd_nand.c Incorrect FIT image format
2729 151 common/cmd_nand.c FIT image format OK
2731 - legacy image format:
2732 CONFIG_IMAGE_FORMAT_LEGACY
2733 enables the legacy image format support in U-Boot.
2736 enabled if CONFIG_FIT_SIGNATURE is not defined.
2738 CONFIG_DISABLE_IMAGE_LEGACY
2739 disable the legacy image format
2741 This define is introduced, as the legacy image format is
2742 enabled per default for backward compatibility.
2744 - Standalone program support:
2745 CONFIG_STANDALONE_LOAD_ADDR
2747 This option defines a board specific value for the
2748 address where standalone program gets loaded, thus
2749 overwriting the architecture dependent default
2752 - Frame Buffer Address:
2755 Define CONFIG_FB_ADDR if you want to use specific
2756 address for frame buffer. This is typically the case
2757 when using a graphics controller has separate video
2758 memory. U-Boot will then place the frame buffer at
2759 the given address instead of dynamically reserving it
2760 in system RAM by calling lcd_setmem(), which grabs
2761 the memory for the frame buffer depending on the
2762 configured panel size.
2764 Please see board_init_f function.
2766 - Automatic software updates via TFTP server
2768 CONFIG_UPDATE_TFTP_CNT_MAX
2769 CONFIG_UPDATE_TFTP_MSEC_MAX
2771 These options enable and control the auto-update feature;
2772 for a more detailed description refer to doc/README.update.
2774 - MTD Support (mtdparts command, UBI support)
2777 Adds the MTD device infrastructure from the Linux kernel.
2778 Needed for mtdparts command support.
2780 CONFIG_MTD_PARTITIONS
2782 Adds the MTD partitioning infrastructure from the Linux
2783 kernel. Needed for UBI support.
2786 CONFIG_UBI_SILENCE_MSG
2788 Make the verbose messages from UBI stop printing. This leaves
2789 warnings and errors enabled.
2792 CONFIG_MTD_UBI_WL_THRESHOLD
2793 This parameter defines the maximum difference between the highest
2794 erase counter value and the lowest erase counter value of eraseblocks
2795 of UBI devices. When this threshold is exceeded, UBI starts performing
2796 wear leveling by means of moving data from eraseblock with low erase
2797 counter to eraseblocks with high erase counter.
2799 The default value should be OK for SLC NAND flashes, NOR flashes and
2800 other flashes which have eraseblock life-cycle 100000 or more.
2801 However, in case of MLC NAND flashes which typically have eraseblock
2802 life-cycle less than 10000, the threshold should be lessened (e.g.,
2803 to 128 or 256, although it does not have to be power of 2).
2807 CONFIG_MTD_UBI_BEB_LIMIT
2808 This option specifies the maximum bad physical eraseblocks UBI
2809 expects on the MTD device (per 1024 eraseblocks). If the
2810 underlying flash does not admit of bad eraseblocks (e.g. NOR
2811 flash), this value is ignored.
2813 NAND datasheets often specify the minimum and maximum NVM
2814 (Number of Valid Blocks) for the flashes' endurance lifetime.
2815 The maximum expected bad eraseblocks per 1024 eraseblocks
2816 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2817 which gives 20 for most NANDs (MaxNVB is basically the total
2818 count of eraseblocks on the chip).
2820 To put it differently, if this value is 20, UBI will try to
2821 reserve about 1.9% of physical eraseblocks for bad blocks
2822 handling. And that will be 1.9% of eraseblocks on the entire
2823 NAND chip, not just the MTD partition UBI attaches. This means
2824 that if you have, say, a NAND flash chip admits maximum 40 bad
2825 eraseblocks, and it is split on two MTD partitions of the same
2826 size, UBI will reserve 40 eraseblocks when attaching a
2831 CONFIG_MTD_UBI_FASTMAP
2832 Fastmap is a mechanism which allows attaching an UBI device
2833 in nearly constant time. Instead of scanning the whole MTD device it
2834 only has to locate a checkpoint (called fastmap) on the device.
2835 The on-flash fastmap contains all information needed to attach
2836 the device. Using fastmap makes only sense on large devices where
2837 attaching by scanning takes long. UBI will not automatically install
2838 a fastmap on old images, but you can set the UBI parameter
2839 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2840 that fastmap-enabled images are still usable with UBI implementations
2841 without fastmap support. On typical flash devices the whole fastmap
2842 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2844 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2845 Set this parameter to enable fastmap automatically on images
2849 CONFIG_MTD_UBI_FM_DEBUG
2850 Enable UBI fastmap debug
2854 CONFIG_UBIFS_SILENCE_MSG
2856 Make the verbose messages from UBIFS stop printing. This leaves
2857 warnings and errors enabled.
2861 Enable building of SPL globally.
2864 LDSCRIPT for linking the SPL binary.
2866 CONFIG_SPL_MAX_FOOTPRINT
2867 Maximum size in memory allocated to the SPL, BSS included.
2868 When defined, the linker checks that the actual memory
2869 used by SPL from _start to __bss_end does not exceed it.
2870 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2871 must not be both defined at the same time.
2874 Maximum size of the SPL image (text, data, rodata, and
2875 linker lists sections), BSS excluded.
2876 When defined, the linker checks that the actual size does
2879 CONFIG_SPL_TEXT_BASE
2880 TEXT_BASE for linking the SPL binary.
2882 CONFIG_SPL_RELOC_TEXT_BASE
2883 Address to relocate to. If unspecified, this is equal to
2884 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2886 CONFIG_SPL_BSS_START_ADDR
2887 Link address for the BSS within the SPL binary.
2889 CONFIG_SPL_BSS_MAX_SIZE
2890 Maximum size in memory allocated to the SPL BSS.
2891 When defined, the linker checks that the actual memory used
2892 by SPL from __bss_start to __bss_end does not exceed it.
2893 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2894 must not be both defined at the same time.
2897 Adress of the start of the stack SPL will use
2899 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2900 When defined, SPL will panic() if the image it has
2901 loaded does not have a signature.
2902 Defining this is useful when code which loads images
2903 in SPL cannot guarantee that absolutely all read errors
2905 An example is the LPC32XX MLC NAND driver, which will
2906 consider that a completely unreadable NAND block is bad,
2907 and thus should be skipped silently.
2909 CONFIG_SPL_RELOC_STACK
2910 Adress of the start of the stack SPL will use after
2911 relocation. If unspecified, this is equal to
2914 CONFIG_SYS_SPL_MALLOC_START
2915 Starting address of the malloc pool used in SPL.
2916 When this option is set the full malloc is used in SPL and
2917 it is set up by spl_init() and before that, the simple malloc()
2918 can be used if CONFIG_SYS_MALLOC_F is defined.
2920 CONFIG_SYS_SPL_MALLOC_SIZE
2921 The size of the malloc pool used in SPL.
2923 CONFIG_SPL_FRAMEWORK
2924 Enable the SPL framework under common/. This framework
2925 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2926 NAND loading of the Linux Kernel.
2929 Enable booting directly to an OS from SPL.
2930 See also: doc/README.falcon
2932 CONFIG_SPL_DISPLAY_PRINT
2933 For ARM, enable an optional function to print more information
2934 about the running system.
2936 CONFIG_SPL_INIT_MINIMAL
2937 Arch init code should be built for a very small image
2939 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2940 Partition on the MMC to load U-Boot from when the MMC is being
2943 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2944 Sector to load kernel uImage from when MMC is being
2945 used in raw mode (for Falcon mode)
2947 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2948 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2949 Sector and number of sectors to load kernel argument
2950 parameters from when MMC is being used in raw mode
2953 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2954 Partition on the MMC to load U-Boot from when the MMC is being
2957 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2958 Filename to read to load U-Boot when reading from filesystem
2960 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2961 Filename to read to load kernel uImage when reading
2962 from filesystem (for Falcon mode)
2964 CONFIG_SPL_FS_LOAD_ARGS_NAME
2965 Filename to read to load kernel argument parameters
2966 when reading from filesystem (for Falcon mode)
2968 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2969 Set this for NAND SPL on PPC mpc83xx targets, so that
2970 start.S waits for the rest of the SPL to load before
2971 continuing (the hardware starts execution after just
2972 loading the first page rather than the full 4K).
2974 CONFIG_SPL_SKIP_RELOCATE
2975 Avoid SPL relocation
2977 CONFIG_SPL_NAND_BASE
2978 Include nand_base.c in the SPL. Requires
2979 CONFIG_SPL_NAND_DRIVERS.
2981 CONFIG_SPL_NAND_DRIVERS
2982 SPL uses normal NAND drivers, not minimal drivers.
2985 Include standard software ECC in the SPL
2987 CONFIG_SPL_NAND_SIMPLE
2988 Support for NAND boot using simple NAND drivers that
2989 expose the cmd_ctrl() interface.
2992 Support for a lightweight UBI (fastmap) scanner and
2995 CONFIG_SPL_NAND_RAW_ONLY
2996 Support to boot only raw u-boot.bin images. Use this only
2997 if you need to save space.
2999 CONFIG_SPL_COMMON_INIT_DDR
3000 Set for common ddr init with serial presence detect in
3003 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3004 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3005 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3006 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3007 CONFIG_SYS_NAND_ECCBYTES
3008 Defines the size and behavior of the NAND that SPL uses
3011 CONFIG_SPL_NAND_BOOT
3012 Add support NAND boot
3014 CONFIG_SYS_NAND_U_BOOT_OFFS
3015 Location in NAND to read U-Boot from
3017 CONFIG_SYS_NAND_U_BOOT_DST
3018 Location in memory to load U-Boot to
3020 CONFIG_SYS_NAND_U_BOOT_SIZE
3021 Size of image to load
3023 CONFIG_SYS_NAND_U_BOOT_START
3024 Entry point in loaded image to jump to
3026 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3027 Define this if you need to first read the OOB and then the
3028 data. This is used, for example, on davinci platforms.
3030 CONFIG_SPL_OMAP3_ID_NAND
3031 Support for an OMAP3-specific set of functions to return the
3032 ID and MFR of the first attached NAND chip, if present.
3034 CONFIG_SPL_RAM_DEVICE
3035 Support for running image already present in ram, in SPL binary
3038 Image offset to which the SPL should be padded before appending
3039 the SPL payload. By default, this is defined as
3040 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3041 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3042 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3045 Final target image containing SPL and payload. Some SPLs
3046 use an arch-specific makefile fragment instead, for
3047 example if more than one image needs to be produced.
3049 CONFIG_FIT_SPL_PRINT
3050 Printing information about a FIT image adds quite a bit of
3051 code to SPL. So this is normally disabled in SPL. Use this
3052 option to re-enable it. This will affect the output of the
3053 bootm command when booting a FIT image.
3057 Enable building of TPL globally.
3060 Image offset to which the TPL should be padded before appending
3061 the TPL payload. By default, this is defined as
3062 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3063 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3064 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3066 - Interrupt support (PPC):
3068 There are common interrupt_init() and timer_interrupt()
3069 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3070 for CPU specific initialization. interrupt_init_cpu()
3071 should set decrementer_count to appropriate value. If
3072 CPU resets decrementer automatically after interrupt
3073 (ppc4xx) it should set decrementer_count to zero.
3074 timer_interrupt() calls timer_interrupt_cpu() for CPU
3075 specific handling. If board has watchdog / status_led
3076 / other_activity_monitor it works automatically from
3077 general timer_interrupt().
3080 Board initialization settings:
3081 ------------------------------
3083 During Initialization u-boot calls a number of board specific functions
3084 to allow the preparation of board specific prerequisites, e.g. pin setup
3085 before drivers are initialized. To enable these callbacks the
3086 following configuration macros have to be defined. Currently this is
3087 architecture specific, so please check arch/your_architecture/lib/board.c
3088 typically in board_init_f() and board_init_r().
3090 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3091 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3092 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3093 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3095 Configuration Settings:
3096 -----------------------
3098 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3099 Optionally it can be defined to support 64-bit memory commands.
3101 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3102 undefine this when you're short of memory.
3104 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3105 width of the commands listed in the 'help' command output.
3107 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3108 prompt for user input.
3110 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3112 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3114 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3116 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3117 the application (usually a Linux kernel) when it is
3120 - CONFIG_SYS_BAUDRATE_TABLE:
3121 List of legal baudrate settings for this board.
3123 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3124 Begin and End addresses of the area used by the
3127 - CONFIG_SYS_ALT_MEMTEST:
3128 Enable an alternate, more extensive memory test.
3130 - CONFIG_SYS_MEMTEST_SCRATCH:
3131 Scratch address used by the alternate memory test
3132 You only need to set this if address zero isn't writeable
3134 - CONFIG_SYS_MEM_RESERVE_SECURE
3135 Only implemented for ARMv8 for now.
3136 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3137 is substracted from total RAM and won't be reported to OS.
3138 This memory can be used as secure memory. A variable
3139 gd->arch.secure_ram is used to track the location. In systems
3140 the RAM base is not zero, or RAM is divided into banks,
3141 this variable needs to be recalcuated to get the address.
3143 - CONFIG_SYS_MEM_TOP_HIDE:
3144 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3145 this specified memory area will get subtracted from the top
3146 (end) of RAM and won't get "touched" at all by U-Boot. By
3147 fixing up gd->ram_size the Linux kernel should gets passed
3148 the now "corrected" memory size and won't touch it either.
3149 This should work for arch/ppc and arch/powerpc. Only Linux
3150 board ports in arch/powerpc with bootwrapper support that
3151 recalculate the memory size from the SDRAM controller setup
3152 will have to get fixed in Linux additionally.
3154 This option can be used as a workaround for the 440EPx/GRx
3155 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3158 WARNING: Please make sure that this value is a multiple of
3159 the Linux page size (normally 4k). If this is not the case,
3160 then the end address of the Linux memory will be located at a
3161 non page size aligned address and this could cause major
3164 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3165 Enable temporary baudrate change while serial download
3167 - CONFIG_SYS_SDRAM_BASE:
3168 Physical start address of SDRAM. _Must_ be 0 here.
3170 - CONFIG_SYS_FLASH_BASE:
3171 Physical start address of Flash memory.
3173 - CONFIG_SYS_MONITOR_BASE:
3174 Physical start address of boot monitor code (set by
3175 make config files to be same as the text base address
3176 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3177 CONFIG_SYS_FLASH_BASE when booting from flash.
3179 - CONFIG_SYS_MONITOR_LEN:
3180 Size of memory reserved for monitor code, used to
3181 determine _at_compile_time_ (!) if the environment is
3182 embedded within the U-Boot image, or in a separate
3185 - CONFIG_SYS_MALLOC_LEN:
3186 Size of DRAM reserved for malloc() use.
3188 - CONFIG_SYS_MALLOC_F_LEN
3189 Size of the malloc() pool for use before relocation. If
3190 this is defined, then a very simple malloc() implementation
3191 will become available before relocation. The address is just
3192 below the global data, and the stack is moved down to make
3195 This feature allocates regions with increasing addresses
3196 within the region. calloc() is supported, but realloc()
3197 is not available. free() is supported but does nothing.
3198 The memory will be freed (or in fact just forgotten) when
3199 U-Boot relocates itself.
3201 - CONFIG_SYS_MALLOC_SIMPLE
3202 Provides a simple and small malloc() and calloc() for those
3203 boards which do not use the full malloc in SPL (which is
3204 enabled with CONFIG_SYS_SPL_MALLOC_START).
3206 - CONFIG_SYS_NONCACHED_MEMORY:
3207 Size of non-cached memory area. This area of memory will be
3208 typically located right below the malloc() area and mapped
3209 uncached in the MMU. This is useful for drivers that would
3210 otherwise require a lot of explicit cache maintenance. For
3211 some drivers it's also impossible to properly maintain the
3212 cache. For example if the regions that need to be flushed
3213 are not a multiple of the cache-line size, *and* padding
3214 cannot be allocated between the regions to align them (i.e.
3215 if the HW requires a contiguous array of regions, and the
3216 size of each region is not cache-aligned), then a flush of
3217 one region may result in overwriting data that hardware has
3218 written to another region in the same cache-line. This can
3219 happen for example in network drivers where descriptors for
3220 buffers are typically smaller than the CPU cache-line (e.g.
3221 16 bytes vs. 32 or 64 bytes).
3223 Non-cached memory is only supported on 32-bit ARM at present.
3225 - CONFIG_SYS_BOOTM_LEN:
3226 Normally compressed uImages are limited to an
3227 uncompressed size of 8 MBytes. If this is not enough,
3228 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3229 to adjust this setting to your needs.
3231 - CONFIG_SYS_BOOTMAPSZ:
3232 Maximum size of memory mapped by the startup code of
3233 the Linux kernel; all data that must be processed by
3234 the Linux kernel (bd_info, boot arguments, FDT blob if
3235 used) must be put below this limit, unless "bootm_low"
3236 environment variable is defined and non-zero. In such case
3237 all data for the Linux kernel must be between "bootm_low"
3238 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3239 variable "bootm_mapsize" will override the value of
3240 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3241 then the value in "bootm_size" will be used instead.
3243 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3244 Enable initrd_high functionality. If defined then the
3245 initrd_high feature is enabled and the bootm ramdisk subcommand
3248 - CONFIG_SYS_BOOT_GET_CMDLINE:
3249 Enables allocating and saving kernel cmdline in space between
3250 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3252 - CONFIG_SYS_BOOT_GET_KBD:
3253 Enables allocating and saving a kernel copy of the bd_info in
3254 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3256 - CONFIG_SYS_MAX_FLASH_BANKS:
3257 Max number of Flash memory banks
3259 - CONFIG_SYS_MAX_FLASH_SECT:
3260 Max number of sectors on a Flash chip
3262 - CONFIG_SYS_FLASH_ERASE_TOUT:
3263 Timeout for Flash erase operations (in ms)
3265 - CONFIG_SYS_FLASH_WRITE_TOUT:
3266 Timeout for Flash write operations (in ms)
3268 - CONFIG_SYS_FLASH_LOCK_TOUT
3269 Timeout for Flash set sector lock bit operation (in ms)
3271 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3272 Timeout for Flash clear lock bits operation (in ms)
3274 - CONFIG_SYS_FLASH_PROTECTION
3275 If defined, hardware flash sectors protection is used
3276 instead of U-Boot software protection.
3278 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3280 Enable TFTP transfers directly to flash memory;
3281 without this option such a download has to be
3282 performed in two steps: (1) download to RAM, and (2)
3283 copy from RAM to flash.
3285 The two-step approach is usually more reliable, since
3286 you can check if the download worked before you erase
3287 the flash, but in some situations (when system RAM is
3288 too limited to allow for a temporary copy of the
3289 downloaded image) this option may be very useful.
3291 - CONFIG_SYS_FLASH_CFI:
3292 Define if the flash driver uses extra elements in the
3293 common flash structure for storing flash geometry.
3295 - CONFIG_FLASH_CFI_DRIVER
3296 This option also enables the building of the cfi_flash driver
3297 in the drivers directory
3299 - CONFIG_FLASH_CFI_MTD
3300 This option enables the building of the cfi_mtd driver
3301 in the drivers directory. The driver exports CFI flash
3304 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3305 Use buffered writes to flash.
3307 - CONFIG_FLASH_SPANSION_S29WS_N
3308 s29ws-n MirrorBit flash has non-standard addresses for buffered
3311 - CONFIG_SYS_FLASH_QUIET_TEST
3312 If this option is defined, the common CFI flash doesn't
3313 print it's warning upon not recognized FLASH banks. This
3314 is useful, if some of the configured banks are only
3315 optionally available.
3317 - CONFIG_FLASH_SHOW_PROGRESS
3318 If defined (must be an integer), print out countdown
3319 digits and dots. Recommended value: 45 (9..1) for 80
3320 column displays, 15 (3..1) for 40 column displays.
3322 - CONFIG_FLASH_VERIFY
3323 If defined, the content of the flash (destination) is compared
3324 against the source after the write operation. An error message
3325 will be printed when the contents are not identical.
3326 Please note that this option is useless in nearly all cases,
3327 since such flash programming errors usually are detected earlier
3328 while unprotecting/erasing/programming. Please only enable
3329 this option if you really know what you are doing.
3331 - CONFIG_SYS_RX_ETH_BUFFER:
3332 Defines the number of Ethernet receive buffers. On some
3333 Ethernet controllers it is recommended to set this value
3334 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3335 buffers can be full shortly after enabling the interface
3336 on high Ethernet traffic.
3337 Defaults to 4 if not defined.
3339 - CONFIG_ENV_MAX_ENTRIES
3341 Maximum number of entries in the hash table that is used
3342 internally to store the environment settings. The default
3343 setting is supposed to be generous and should work in most
3344 cases. This setting can be used to tune behaviour; see
3345 lib/hashtable.c for details.
3347 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3348 - CONFIG_ENV_FLAGS_LIST_STATIC
3349 Enable validation of the values given to environment variables when
3350 calling env set. Variables can be restricted to only decimal,
3351 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3352 the variables can also be restricted to IP address or MAC address.
3354 The format of the list is:
3355 type_attribute = [s|d|x|b|i|m]
3356 access_attribute = [a|r|o|c]
3357 attributes = type_attribute[access_attribute]
3358 entry = variable_name[:attributes]
3361 The type attributes are:
3362 s - String (default)
3365 b - Boolean ([1yYtT|0nNfF])
3369 The access attributes are:
3375 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3376 Define this to a list (string) to define the ".flags"
3377 environment variable in the default or embedded environment.
3379 - CONFIG_ENV_FLAGS_LIST_STATIC
3380 Define this to a list (string) to define validation that
3381 should be done if an entry is not found in the ".flags"
3382 environment variable. To override a setting in the static
3383 list, simply add an entry for the same variable name to the
3386 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3387 regular expression. This allows multiple variables to define the same
3388 flags without explicitly listing them for each variable.
3390 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3391 If defined, don't allow the -f switch to env set override variable
3395 If stdint.h is available with your toolchain you can define this
3396 option to enable it. You can provide option 'USE_STDINT=1' when
3397 building U-Boot to enable this.
3399 The following definitions that deal with the placement and management
3400 of environment data (variable area); in general, we support the
3401 following configurations:
3403 - CONFIG_BUILD_ENVCRC:
3405 Builds up envcrc with the target environment so that external utils
3406 may easily extract it and embed it in final U-Boot images.
3408 BE CAREFUL! The first access to the environment happens quite early
3409 in U-Boot initialization (when we try to get the setting of for the
3410 console baudrate). You *MUST* have mapped your NVRAM area then, or
3413 Please note that even with NVRAM we still use a copy of the
3414 environment in RAM: we could work on NVRAM directly, but we want to
3415 keep settings there always unmodified except somebody uses "saveenv"
3416 to save the current settings.
3418 BE CAREFUL! For some special cases, the local device can not use
3419 "saveenv" command. For example, the local device will get the
3420 environment stored in a remote NOR flash by SRIO or PCIE link,
3421 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3423 - CONFIG_NAND_ENV_DST
3425 Defines address in RAM to which the nand_spl code should copy the
3426 environment. If redundant environment is used, it will be copied to
3427 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3429 Please note that the environment is read-only until the monitor
3430 has been relocated to RAM and a RAM copy of the environment has been
3431 created; also, when using EEPROM you will have to use getenv_f()
3432 until then to read environment variables.
3434 The environment is protected by a CRC32 checksum. Before the monitor
3435 is relocated into RAM, as a result of a bad CRC you will be working
3436 with the compiled-in default environment - *silently*!!! [This is
3437 necessary, because the first environment variable we need is the
3438 "baudrate" setting for the console - if we have a bad CRC, we don't
3439 have any device yet where we could complain.]
3441 Note: once the monitor has been relocated, then it will complain if
3442 the default environment is used; a new CRC is computed as soon as you
3443 use the "saveenv" command to store a valid environment.
3445 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3446 Echo the inverted Ethernet link state to the fault LED.
3448 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3449 also needs to be defined.
3451 - CONFIG_SYS_FAULT_MII_ADDR:
3452 MII address of the PHY to check for the Ethernet link state.
3454 - CONFIG_NS16550_MIN_FUNCTIONS:
3455 Define this if you desire to only have use of the NS16550_init
3456 and NS16550_putc functions for the serial driver located at
3457 drivers/serial/ns16550.c. This option is useful for saving
3458 space for already greatly restricted images, including but not
3459 limited to NAND_SPL configurations.
3461 - CONFIG_DISPLAY_BOARDINFO
3462 Display information about the board that U-Boot is running on
3463 when U-Boot starts up. The board function checkboard() is called
3466 - CONFIG_DISPLAY_BOARDINFO_LATE
3467 Similar to the previous option, but display this information
3468 later, once stdio is running and output goes to the LCD, if
3471 - CONFIG_BOARD_SIZE_LIMIT:
3472 Maximum size of the U-Boot image. When defined, the
3473 build system checks that the actual size does not
3476 Low Level (hardware related) configuration options:
3477 ---------------------------------------------------
3479 - CONFIG_SYS_CACHELINE_SIZE:
3480 Cache Line Size of the CPU.
3482 - CONFIG_SYS_CCSRBAR_DEFAULT:
3483 Default (power-on reset) physical address of CCSR on Freescale
3486 - CONFIG_SYS_CCSRBAR:
3487 Virtual address of CCSR. On a 32-bit build, this is typically
3488 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3490 - CONFIG_SYS_CCSRBAR_PHYS:
3491 Physical address of CCSR. CCSR can be relocated to a new
3492 physical address, if desired. In this case, this macro should
3493 be set to that address. Otherwise, it should be set to the
3494 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3495 is typically relocated on 36-bit builds. It is recommended
3496 that this macro be defined via the _HIGH and _LOW macros:
3498 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3499 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3501 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3502 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3503 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3504 used in assembly code, so it must not contain typecasts or
3505 integer size suffixes (e.g. "ULL").
3507 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3508 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3509 used in assembly code, so it must not contain typecasts or
3510 integer size suffixes (e.g. "ULL").
3512 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3513 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3514 forced to a value that ensures that CCSR is not relocated.
3516 - Floppy Disk Support:
3517 CONFIG_SYS_FDC_DRIVE_NUMBER
3519 the default drive number (default value 0)
3521 CONFIG_SYS_ISA_IO_STRIDE
3523 defines the spacing between FDC chipset registers
3526 CONFIG_SYS_ISA_IO_OFFSET
3528 defines the offset of register from address. It
3529 depends on which part of the data bus is connected to
3530 the FDC chipset. (default value 0)
3532 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3533 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3536 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3537 fdc_hw_init() is called at the beginning of the FDC
3538 setup. fdc_hw_init() must be provided by the board
3539 source code. It is used to make hardware-dependent
3543 Most IDE controllers were designed to be connected with PCI
3544 interface. Only few of them were designed for AHB interface.
3545 When software is doing ATA command and data transfer to
3546 IDE devices through IDE-AHB controller, some additional
3547 registers accessing to these kind of IDE-AHB controller
3550 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3551 DO NOT CHANGE unless you know exactly what you're
3552 doing! (11-4) [MPC8xx systems only]
3554 - CONFIG_SYS_INIT_RAM_ADDR:
3556 Start address of memory area that can be used for
3557 initial data and stack; please note that this must be
3558 writable memory that is working WITHOUT special
3559 initialization, i. e. you CANNOT use normal RAM which
3560 will become available only after programming the
3561 memory controller and running certain initialization
3564 U-Boot uses the following memory types:
3565 - MPC8xx: IMMR (internal memory of the CPU)
3567 - CONFIG_SYS_GBL_DATA_OFFSET:
3569 Offset of the initial data structure in the memory
3570 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3571 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3572 data is located at the end of the available space
3573 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3574 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3575 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3576 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3579 On the MPC824X (or other systems that use the data
3580 cache for initial memory) the address chosen for
3581 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3582 point to an otherwise UNUSED address space between
3583 the top of RAM and the start of the PCI space.
3585 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3587 - CONFIG_SYS_OR_TIMING_SDRAM:
3590 - CONFIG_SYS_MAMR_PTA:
3591 periodic timer for refresh
3593 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3594 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3595 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3596 CONFIG_SYS_BR1_PRELIM:
3597 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3599 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3600 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3601 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3602 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3604 - CONFIG_PCI_ENUM_ONLY
3605 Only scan through and get the devices on the buses.
3606 Don't do any setup work, presumably because someone or
3607 something has already done it, and we don't need to do it
3608 a second time. Useful for platforms that are pre-booted
3609 by coreboot or similar.
3611 - CONFIG_PCI_INDIRECT_BRIDGE:
3612 Enable support for indirect PCI bridges.
3615 Chip has SRIO or not
3618 Board has SRIO 1 port available
3621 Board has SRIO 2 port available
3623 - CONFIG_SRIO_PCIE_BOOT_MASTER
3624 Board can support master function for Boot from SRIO and PCIE
3626 - CONFIG_SYS_SRIOn_MEM_VIRT:
3627 Virtual Address of SRIO port 'n' memory region
3629 - CONFIG_SYS_SRIOn_MEM_PHYS:
3630 Physical Address of SRIO port 'n' memory region
3632 - CONFIG_SYS_SRIOn_MEM_SIZE:
3633 Size of SRIO port 'n' memory region
3635 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3636 Defined to tell the NAND controller that the NAND chip is using
3638 Not all NAND drivers use this symbol.
3639 Example of drivers that use it:
3640 - drivers/mtd/nand/ndfc.c
3641 - drivers/mtd/nand/mxc_nand.c
3643 - CONFIG_SYS_NDFC_EBC0_CFG
3644 Sets the EBC0_CFG register for the NDFC. If not defined
3645 a default value will be used.
3648 Get DDR timing information from an I2C EEPROM. Common
3649 with pluggable memory modules such as SODIMMs
3652 I2C address of the SPD EEPROM
3654 - CONFIG_SYS_SPD_BUS_NUM
3655 If SPD EEPROM is on an I2C bus other than the first
3656 one, specify here. Note that the value must resolve
3657 to something your driver can deal with.
3659 - CONFIG_SYS_DDR_RAW_TIMING
3660 Get DDR timing information from other than SPD. Common with
3661 soldered DDR chips onboard without SPD. DDR raw timing
3662 parameters are extracted from datasheet and hard-coded into
3663 header files or board specific files.
3665 - CONFIG_FSL_DDR_INTERACTIVE
3666 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3668 - CONFIG_FSL_DDR_SYNC_REFRESH
3669 Enable sync of refresh for multiple controllers.
3671 - CONFIG_FSL_DDR_BIST
3672 Enable built-in memory test for Freescale DDR controllers.
3674 - CONFIG_SYS_83XX_DDR_USES_CS0
3675 Only for 83xx systems. If specified, then DDR should
3676 be configured using CS0 and CS1 instead of CS2 and CS3.
3679 Enable RMII mode for all FECs.
3680 Note that this is a global option, we can't
3681 have one FEC in standard MII mode and another in RMII mode.
3683 - CONFIG_CRC32_VERIFY
3684 Add a verify option to the crc32 command.
3687 => crc32 -v <address> <count> <crc32>
3689 Where address/count indicate a memory area
3690 and crc32 is the correct crc32 which the
3694 Add the "loopw" memory command. This only takes effect if
3695 the memory commands are activated globally (CONFIG_CMD_MEMORY).
3698 Add the "mdc" and "mwc" memory commands. These are cyclic
3703 This command will print 4 bytes (10,11,12,13) each 500 ms.
3705 => mwc.l 100 12345678 10
3706 This command will write 12345678 to address 100 all 10 ms.
3708 This only takes effect if the memory commands are activated
3709 globally (CONFIG_CMD_MEMORY).
3711 - CONFIG_SKIP_LOWLEVEL_INIT
3712 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3713 low level initializations (like setting up the memory
3714 controller) are omitted and/or U-Boot does not
3715 relocate itself into RAM.
3717 Normally this variable MUST NOT be defined. The only
3718 exception is when U-Boot is loaded (to RAM) by some
3719 other boot loader or by a debugger which performs
3720 these initializations itself.
3722 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3723 [ARM926EJ-S only] This allows just the call to lowlevel_init()
3724 to be skipped. The normal CP15 init (such as enabling the
3725 instruction cache) is still performed.
3728 Modifies the behaviour of start.S when compiling a loader
3729 that is executed before the actual U-Boot. E.g. when
3730 compiling a NAND SPL.
3733 Modifies the behaviour of start.S when compiling a loader
3734 that is executed after the SPL and before the actual U-Boot.
3735 It is loaded by the SPL.
3737 - CONFIG_SYS_MPC85XX_NO_RESETVEC
3738 Only for 85xx systems. If this variable is specified, the section
3739 .resetvec is not kept and the section .bootpg is placed in the
3740 previous 4k of the .text section.
3742 - CONFIG_ARCH_MAP_SYSMEM
3743 Generally U-Boot (and in particular the md command) uses
3744 effective address. It is therefore not necessary to regard
3745 U-Boot address as virtual addresses that need to be translated
3746 to physical addresses. However, sandbox requires this, since
3747 it maintains its own little RAM buffer which contains all
3748 addressable memory. This option causes some memory accesses
3749 to be mapped through map_sysmem() / unmap_sysmem().
3751 - CONFIG_X86_RESET_VECTOR
3752 If defined, the x86 reset vector code is included. This is not
3753 needed when U-Boot is running from Coreboot.
3755 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
3756 Enables the RTC32K OSC on AM33xx based plattforms
3758 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3759 Option to disable subpage write in NAND driver
3760 driver that uses this:
3761 drivers/mtd/nand/davinci_nand.c
3763 Freescale QE/FMAN Firmware Support:
3764 -----------------------------------
3766 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3767 loading of "firmware", which is encoded in the QE firmware binary format.
3768 This firmware often needs to be loaded during U-Boot booting, so macros
3769 are used to identify the storage device (NOR flash, SPI, etc) and the address
3772 - CONFIG_SYS_FMAN_FW_ADDR
3773 The address in the storage device where the FMAN microcode is located. The
3774 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3777 - CONFIG_SYS_QE_FW_ADDR
3778 The address in the storage device where the QE microcode is located. The
3779 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3782 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3783 The maximum possible size of the firmware. The firmware binary format
3784 has a field that specifies the actual size of the firmware, but it
3785 might not be possible to read any part of the firmware unless some
3786 local storage is allocated to hold the entire firmware first.
3788 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3789 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3790 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3791 virtual address in NOR flash.
3793 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3794 Specifies that QE/FMAN firmware is located in NAND flash.
3795 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3797 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3798 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3799 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3801 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3802 Specifies that QE/FMAN firmware is located in the remote (master)
3803 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3804 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3805 window->master inbound window->master LAW->the ucode address in
3806 master's memory space.
3808 Freescale Layerscape Management Complex Firmware Support:
3809 ---------------------------------------------------------
3810 The Freescale Layerscape Management Complex (MC) supports the loading of
3812 This firmware often needs to be loaded during U-Boot booting, so macros
3813 are used to identify the storage device (NOR flash, SPI, etc) and the address
3816 - CONFIG_FSL_MC_ENET
3817 Enable the MC driver for Layerscape SoCs.
3819 Freescale Layerscape Debug Server Support:
3820 -------------------------------------------
3821 The Freescale Layerscape Debug Server Support supports the loading of
3822 "Debug Server firmware" and triggering SP boot-rom.
3823 This firmware often needs to be loaded during U-Boot booting.
3825 - CONFIG_SYS_MC_RSV_MEM_ALIGN
3826 Define alignment of reserved memory MC requires
3831 In order to achieve reproducible builds, timestamps used in the U-Boot build
3832 process have to be set to a fixed value.
3834 This is done using the SOURCE_DATE_EPOCH environment variable.
3835 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3836 option for U-Boot or an environment variable in U-Boot.
3838 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3840 Building the Software:
3841 ======================
3843 Building U-Boot has been tested in several native build environments
3844 and in many different cross environments. Of course we cannot support
3845 all possibly existing versions of cross development tools in all
3846 (potentially obsolete) versions. In case of tool chain problems we
3847 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3848 which is extensively used to build and test U-Boot.
3850 If you are not using a native environment, it is assumed that you
3851 have GNU cross compiling tools available in your path. In this case,
3852 you must set the environment variable CROSS_COMPILE in your shell.
3853 Note that no changes to the Makefile or any other source files are
3854 necessary. For example using the ELDK on a 4xx CPU, please enter:
3856 $ CROSS_COMPILE=ppc_4xx-
3857 $ export CROSS_COMPILE
3859 Note: If you wish to generate Windows versions of the utilities in
3860 the tools directory you can use the MinGW toolchain
3861 (http://www.mingw.org). Set your HOST tools to the MinGW
3862 toolchain and execute 'make tools'. For example:
3864 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3866 Binaries such as tools/mkimage.exe will be created which can
3867 be executed on computers running Windows.
3869 U-Boot is intended to be simple to build. After installing the
3870 sources you must configure U-Boot for one specific board type. This
3875 where "NAME_defconfig" is the name of one of the existing configu-
3876 rations; see boards.cfg for supported names.
3878 Note: for some board special configuration names may exist; check if
3879 additional information is available from the board vendor; for
3880 instance, the TQM823L systems are available without (standard)
3881 or with LCD support. You can select such additional "features"
3882 when choosing the configuration, i. e.
3884 make TQM823L_defconfig
3885 - will configure for a plain TQM823L, i. e. no LCD support
3887 make TQM823L_LCD_defconfig
3888 - will configure for a TQM823L with U-Boot console on LCD
3893 Finally, type "make all", and you should get some working U-Boot
3894 images ready for download to / installation on your system:
3896 - "u-boot.bin" is a raw binary image
3897 - "u-boot" is an image in ELF binary format
3898 - "u-boot.srec" is in Motorola S-Record format
3900 By default the build is performed locally and the objects are saved
3901 in the source directory. One of the two methods can be used to change
3902 this behavior and build U-Boot to some external directory:
3904 1. Add O= to the make command line invocations:
3906 make O=/tmp/build distclean
3907 make O=/tmp/build NAME_defconfig
3908 make O=/tmp/build all
3910 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
3912 export KBUILD_OUTPUT=/tmp/build
3917 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
3921 Please be aware that the Makefiles assume you are using GNU make, so
3922 for instance on NetBSD you might need to use "gmake" instead of
3926 If the system board that you have is not listed, then you will need
3927 to port U-Boot to your hardware platform. To do this, follow these
3930 1. Create a new directory to hold your board specific code. Add any
3931 files you need. In your board directory, you will need at least
3932 the "Makefile" and a "<board>.c".
3933 2. Create a new configuration file "include/configs/<board>.h" for
3935 3. If you're porting U-Boot to a new CPU, then also create a new
3936 directory to hold your CPU specific code. Add any files you need.
3937 4. Run "make <board>_defconfig" with your new name.
3938 5. Type "make", and you should get a working "u-boot.srec" file
3939 to be installed on your target system.
3940 6. Debug and solve any problems that might arise.
3941 [Of course, this last step is much harder than it sounds.]
3944 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3945 ==============================================================
3947 If you have modified U-Boot sources (for instance added a new board
3948 or support for new devices, a new CPU, etc.) you are expected to
3949 provide feedback to the other developers. The feedback normally takes
3950 the form of a "patch", i. e. a context diff against a certain (latest
3951 official or latest in the git repository) version of U-Boot sources.
3953 But before you submit such a patch, please verify that your modifi-
3954 cation did not break existing code. At least make sure that *ALL* of
3955 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3956 just run the buildman script (tools/buildman/buildman), which will
3957 configure and build U-Boot for ALL supported system. Be warned, this
3958 will take a while. Please see the buildman README, or run 'buildman -H'
3962 See also "U-Boot Porting Guide" below.
3965 Monitor Commands - Overview:
3966 ============================
3968 go - start application at address 'addr'
3969 run - run commands in an environment variable
3970 bootm - boot application image from memory
3971 bootp - boot image via network using BootP/TFTP protocol
3972 bootz - boot zImage from memory
3973 tftpboot- boot image via network using TFTP protocol
3974 and env variables "ipaddr" and "serverip"
3975 (and eventually "gatewayip")
3976 tftpput - upload a file via network using TFTP protocol
3977 rarpboot- boot image via network using RARP/TFTP protocol
3978 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3979 loads - load S-Record file over serial line
3980 loadb - load binary file over serial line (kermit mode)
3982 mm - memory modify (auto-incrementing)
3983 nm - memory modify (constant address)
3984 mw - memory write (fill)
3986 cmp - memory compare
3987 crc32 - checksum calculation
3988 i2c - I2C sub-system
3989 sspi - SPI utility commands
3990 base - print or set address offset
3991 printenv- print environment variables
3992 setenv - set environment variables
3993 saveenv - save environment variables to persistent storage
3994 protect - enable or disable FLASH write protection
3995 erase - erase FLASH memory
3996 flinfo - print FLASH memory information
3997 nand - NAND memory operations (see doc/README.nand)
3998 bdinfo - print Board Info structure
3999 iminfo - print header information for application image
4000 coninfo - print console devices and informations
4001 ide - IDE sub-system
4002 loop - infinite loop on address range
4003 loopw - infinite write loop on address range
4004 mtest - simple RAM test
4005 icache - enable or disable instruction cache
4006 dcache - enable or disable data cache
4007 reset - Perform RESET of the CPU
4008 echo - echo args to console
4009 version - print monitor version
4010 help - print online help
4011 ? - alias for 'help'
4014 Monitor Commands - Detailed Description:
4015 ========================================
4019 For now: just type "help <command>".
4022 Environment Variables:
4023 ======================
4025 U-Boot supports user configuration using Environment Variables which
4026 can be made persistent by saving to Flash memory.
4028 Environment Variables are set using "setenv", printed using
4029 "printenv", and saved to Flash using "saveenv". Using "setenv"
4030 without a value can be used to delete a variable from the
4031 environment. As long as you don't save the environment you are
4032 working with an in-memory copy. In case the Flash area containing the
4033 environment is erased by accident, a default environment is provided.
4035 Some configuration options can be set using Environment Variables.
4037 List of environment variables (most likely not complete):
4039 baudrate - see CONFIG_BAUDRATE
4041 bootdelay - see CONFIG_BOOTDELAY
4043 bootcmd - see CONFIG_BOOTCOMMAND
4045 bootargs - Boot arguments when booting an RTOS image
4047 bootfile - Name of the image to load with TFTP
4049 bootm_low - Memory range available for image processing in the bootm
4050 command can be restricted. This variable is given as
4051 a hexadecimal number and defines lowest address allowed
4052 for use by the bootm command. See also "bootm_size"
4053 environment variable. Address defined by "bootm_low" is
4054 also the base of the initial memory mapping for the Linux
4055 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4058 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4059 This variable is given as a hexadecimal number and it
4060 defines the size of the memory region starting at base
4061 address bootm_low that is accessible by the Linux kernel
4062 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4063 as the default value if it is defined, and bootm_size is
4066 bootm_size - Memory range available for image processing in the bootm
4067 command can be restricted. This variable is given as
4068 a hexadecimal number and defines the size of the region
4069 allowed for use by the bootm command. See also "bootm_low"
4070 environment variable.
4072 updatefile - Location of the software update file on a TFTP server, used
4073 by the automatic software update feature. Please refer to
4074 documentation in doc/README.update for more details.
4076 autoload - if set to "no" (any string beginning with 'n'),
4077 "bootp" will just load perform a lookup of the
4078 configuration from the BOOTP server, but not try to
4079 load any image using TFTP
4081 autostart - if set to "yes", an image loaded using the "bootp",
4082 "rarpboot", "tftpboot" or "diskboot" commands will
4083 be automatically started (by internally calling
4086 If set to "no", a standalone image passed to the
4087 "bootm" command will be copied to the load address
4088 (and eventually uncompressed), but NOT be started.
4089 This can be used to load and uncompress arbitrary
4092 fdt_high - if set this restricts the maximum address that the
4093 flattened device tree will be copied into upon boot.
4094 For example, if you have a system with 1 GB memory
4095 at physical address 0x10000000, while Linux kernel
4096 only recognizes the first 704 MB as low memory, you
4097 may need to set fdt_high as 0x3C000000 to have the
4098 device tree blob be copied to the maximum address
4099 of the 704 MB low memory, so that Linux kernel can
4100 access it during the boot procedure.
4102 If this is set to the special value 0xFFFFFFFF then
4103 the fdt will not be copied at all on boot. For this
4104 to work it must reside in writable memory, have
4105 sufficient padding on the end of it for u-boot to
4106 add the information it needs into it, and the memory
4107 must be accessible by the kernel.
4109 fdtcontroladdr- if set this is the address of the control flattened
4110 device tree used by U-Boot when CONFIG_OF_CONTROL is
4113 i2cfast - (PPC405GP|PPC405EP only)
4114 if set to 'y' configures Linux I2C driver for fast
4115 mode (400kHZ). This environment variable is used in
4116 initialization code. So, for changes to be effective
4117 it must be saved and board must be reset.
4119 initrd_high - restrict positioning of initrd images:
4120 If this variable is not set, initrd images will be
4121 copied to the highest possible address in RAM; this
4122 is usually what you want since it allows for
4123 maximum initrd size. If for some reason you want to
4124 make sure that the initrd image is loaded below the
4125 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4126 variable to a value of "no" or "off" or "0".
4127 Alternatively, you can set it to a maximum upper
4128 address to use (U-Boot will still check that it
4129 does not overwrite the U-Boot stack and data).
4131 For instance, when you have a system with 16 MB
4132 RAM, and want to reserve 4 MB from use by Linux,
4133 you can do this by adding "mem=12M" to the value of
4134 the "bootargs" variable. However, now you must make
4135 sure that the initrd image is placed in the first
4136 12 MB as well - this can be done with
4138 setenv initrd_high 00c00000
4140 If you set initrd_high to 0xFFFFFFFF, this is an
4141 indication to U-Boot that all addresses are legal
4142 for the Linux kernel, including addresses in flash
4143 memory. In this case U-Boot will NOT COPY the
4144 ramdisk at all. This may be useful to reduce the
4145 boot time on your system, but requires that this
4146 feature is supported by your Linux kernel.
4148 ipaddr - IP address; needed for tftpboot command
4150 loadaddr - Default load address for commands like "bootp",
4151 "rarpboot", "tftpboot", "loadb" or "diskboot"
4153 loads_echo - see CONFIG_LOADS_ECHO
4155 serverip - TFTP server IP address; needed for tftpboot command
4157 bootretry - see CONFIG_BOOT_RETRY_TIME
4159 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4161 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4163 ethprime - controls which interface is used first.
4165 ethact - controls which interface is currently active.
4166 For example you can do the following
4168 => setenv ethact FEC
4169 => ping 192.168.0.1 # traffic sent on FEC
4170 => setenv ethact SCC
4171 => ping 10.0.0.1 # traffic sent on SCC
4173 ethrotate - When set to "no" U-Boot does not go through all
4174 available network interfaces.
4175 It just stays at the currently selected interface.
4177 netretry - When set to "no" each network operation will
4178 either succeed or fail without retrying.
4179 When set to "once" the network operation will
4180 fail when all the available network interfaces
4181 are tried once without success.
4182 Useful on scripts which control the retry operation
4185 npe_ucode - set load address for the NPE microcode
4187 silent_linux - If set then Linux will be told to boot silently, by
4188 changing the console to be empty. If "yes" it will be
4189 made silent. If "no" it will not be made silent. If
4190 unset, then it will be made silent if the U-Boot console
4193 tftpsrcp - If this is set, the value is used for TFTP's
4196 tftpdstp - If this is set, the value is used for TFTP's UDP
4197 destination port instead of the Well Know Port 69.
4199 tftpblocksize - Block size to use for TFTP transfers; if not set,
4200 we use the TFTP server's default block size
4202 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4203 seconds, minimum value is 1000 = 1 second). Defines
4204 when a packet is considered to be lost so it has to
4205 be retransmitted. The default is 5000 = 5 seconds.
4206 Lowering this value may make downloads succeed
4207 faster in networks with high packet loss rates or
4208 with unreliable TFTP servers.
4210 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4211 unit, minimum value = 0). Defines how many timeouts
4212 can happen during a single file transfer before that
4213 transfer is aborted. The default is 10, and 0 means
4214 'no timeouts allowed'. Increasing this value may help
4215 downloads succeed with high packet loss rates, or with
4216 unreliable TFTP servers or client hardware.
4218 vlan - When set to a value < 4095 the traffic over
4219 Ethernet is encapsulated/received over 802.1q
4222 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4223 Unsigned value, in milliseconds. If not set, the period will
4224 be either the default (28000), or a value based on
4225 CONFIG_NET_RETRY_COUNT, if defined. This value has
4226 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4228 The following image location variables contain the location of images
4229 used in booting. The "Image" column gives the role of the image and is
4230 not an environment variable name. The other columns are environment
4231 variable names. "File Name" gives the name of the file on a TFTP
4232 server, "RAM Address" gives the location in RAM the image will be
4233 loaded to, and "Flash Location" gives the image's address in NOR
4234 flash or offset in NAND flash.
4236 *Note* - these variables don't have to be defined for all boards, some
4237 boards currently use other variables for these purposes, and some
4238 boards use these variables for other purposes.
4240 Image File Name RAM Address Flash Location
4241 ----- --------- ----------- --------------
4242 u-boot u-boot u-boot_addr_r u-boot_addr
4243 Linux kernel bootfile kernel_addr_r kernel_addr
4244 device tree blob fdtfile fdt_addr_r fdt_addr
4245 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4247 The following environment variables may be used and automatically
4248 updated by the network boot commands ("bootp" and "rarpboot"),
4249 depending the information provided by your boot server:
4251 bootfile - see above
4252 dnsip - IP address of your Domain Name Server
4253 dnsip2 - IP address of your secondary Domain Name Server
4254 gatewayip - IP address of the Gateway (Router) to use
4255 hostname - Target hostname
4257 netmask - Subnet Mask
4258 rootpath - Pathname of the root filesystem on the NFS server
4259 serverip - see above
4262 There are two special Environment Variables:
4264 serial# - contains hardware identification information such
4265 as type string and/or serial number
4266 ethaddr - Ethernet address
4268 These variables can be set only once (usually during manufacturing of
4269 the board). U-Boot refuses to delete or overwrite these variables
4270 once they have been set once.
4273 Further special Environment Variables:
4275 ver - Contains the U-Boot version string as printed
4276 with the "version" command. This variable is
4277 readonly (see CONFIG_VERSION_VARIABLE).
4280 Please note that changes to some configuration parameters may take
4281 only effect after the next boot (yes, that's just like Windoze :-).
4284 Callback functions for environment variables:
4285 ---------------------------------------------
4287 For some environment variables, the behavior of u-boot needs to change
4288 when their values are changed. This functionality allows functions to
4289 be associated with arbitrary variables. On creation, overwrite, or
4290 deletion, the callback will provide the opportunity for some side
4291 effect to happen or for the change to be rejected.
4293 The callbacks are named and associated with a function using the
4294 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4296 These callbacks are associated with variables in one of two ways. The
4297 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4298 in the board configuration to a string that defines a list of
4299 associations. The list must be in the following format:
4301 entry = variable_name[:callback_name]
4304 If the callback name is not specified, then the callback is deleted.
4305 Spaces are also allowed anywhere in the list.
4307 Callbacks can also be associated by defining the ".callbacks" variable
4308 with the same list format above. Any association in ".callbacks" will
4309 override any association in the static list. You can define
4310 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4311 ".callbacks" environment variable in the default or embedded environment.
4313 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4314 regular expression. This allows multiple variables to be connected to
4315 the same callback without explicitly listing them all out.
4318 Command Line Parsing:
4319 =====================
4321 There are two different command line parsers available with U-Boot:
4322 the old "simple" one, and the much more powerful "hush" shell:
4324 Old, simple command line parser:
4325 --------------------------------
4327 - supports environment variables (through setenv / saveenv commands)
4328 - several commands on one line, separated by ';'
4329 - variable substitution using "... ${name} ..." syntax
4330 - special characters ('$', ';') can be escaped by prefixing with '\',
4332 setenv bootcmd bootm \${address}
4333 - You can also escape text by enclosing in single apostrophes, for example:
4334 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4339 - similar to Bourne shell, with control structures like
4340 if...then...else...fi, for...do...done; while...do...done,
4341 until...do...done, ...
4342 - supports environment ("global") variables (through setenv / saveenv
4343 commands) and local shell variables (through standard shell syntax
4344 "name=value"); only environment variables can be used with "run"
4350 (1) If a command line (or an environment variable executed by a "run"
4351 command) contains several commands separated by semicolon, and
4352 one of these commands fails, then the remaining commands will be
4355 (2) If you execute several variables with one call to run (i. e.
4356 calling run with a list of variables as arguments), any failing
4357 command will cause "run" to terminate, i. e. the remaining
4358 variables are not executed.
4360 Note for Redundant Ethernet Interfaces:
4361 =======================================
4363 Some boards come with redundant Ethernet interfaces; U-Boot supports
4364 such configurations and is capable of automatic selection of a
4365 "working" interface when needed. MAC assignment works as follows:
4367 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4368 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4369 "eth1addr" (=>eth1), "eth2addr", ...
4371 If the network interface stores some valid MAC address (for instance
4372 in SROM), this is used as default address if there is NO correspon-
4373 ding setting in the environment; if the corresponding environment
4374 variable is set, this overrides the settings in the card; that means:
4376 o If the SROM has a valid MAC address, and there is no address in the
4377 environment, the SROM's address is used.
4379 o If there is no valid address in the SROM, and a definition in the
4380 environment exists, then the value from the environment variable is
4383 o If both the SROM and the environment contain a MAC address, and
4384 both addresses are the same, this MAC address is used.
4386 o If both the SROM and the environment contain a MAC address, and the
4387 addresses differ, the value from the environment is used and a
4390 o If neither SROM nor the environment contain a MAC address, an error
4391 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4392 a random, locally-assigned MAC is used.
4394 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4395 will be programmed into hardware as part of the initialization process. This
4396 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4397 The naming convention is as follows:
4398 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4403 U-Boot is capable of booting (and performing other auxiliary operations on)
4404 images in two formats:
4406 New uImage format (FIT)
4407 -----------------------
4409 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4410 to Flattened Device Tree). It allows the use of images with multiple
4411 components (several kernels, ramdisks, etc.), with contents protected by
4412 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4418 Old image format is based on binary files which can be basically anything,
4419 preceded by a special header; see the definitions in include/image.h for
4420 details; basically, the header defines the following image properties:
4422 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4423 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4424 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4425 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4427 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
4428 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4429 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4430 * Compression Type (uncompressed, gzip, bzip2)
4436 The header is marked by a special Magic Number, and both the header
4437 and the data portions of the image are secured against corruption by
4444 Although U-Boot should support any OS or standalone application
4445 easily, the main focus has always been on Linux during the design of
4448 U-Boot includes many features that so far have been part of some
4449 special "boot loader" code within the Linux kernel. Also, any
4450 "initrd" images to be used are no longer part of one big Linux image;
4451 instead, kernel and "initrd" are separate images. This implementation
4452 serves several purposes:
4454 - the same features can be used for other OS or standalone
4455 applications (for instance: using compressed images to reduce the
4456 Flash memory footprint)
4458 - it becomes much easier to port new Linux kernel versions because
4459 lots of low-level, hardware dependent stuff are done by U-Boot
4461 - the same Linux kernel image can now be used with different "initrd"
4462 images; of course this also means that different kernel images can
4463 be run with the same "initrd". This makes testing easier (you don't
4464 have to build a new "zImage.initrd" Linux image when you just
4465 change a file in your "initrd"). Also, a field-upgrade of the
4466 software is easier now.
4472 Porting Linux to U-Boot based systems:
4473 ---------------------------------------
4475 U-Boot cannot save you from doing all the necessary modifications to
4476 configure the Linux device drivers for use with your target hardware
4477 (no, we don't intend to provide a full virtual machine interface to
4480 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4482 Just make sure your machine specific header file (for instance
4483 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4484 Information structure as we define in include/asm-<arch>/u-boot.h,
4485 and make sure that your definition of IMAP_ADDR uses the same value
4486 as your U-Boot configuration in CONFIG_SYS_IMMR.
4488 Note that U-Boot now has a driver model, a unified model for drivers.
4489 If you are adding a new driver, plumb it into driver model. If there
4490 is no uclass available, you are encouraged to create one. See
4494 Configuring the Linux kernel:
4495 -----------------------------
4497 No specific requirements for U-Boot. Make sure you have some root
4498 device (initial ramdisk, NFS) for your target system.
4501 Building a Linux Image:
4502 -----------------------
4504 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4505 not used. If you use recent kernel source, a new build target
4506 "uImage" will exist which automatically builds an image usable by
4507 U-Boot. Most older kernels also have support for a "pImage" target,
4508 which was introduced for our predecessor project PPCBoot and uses a
4509 100% compatible format.
4513 make TQM850L_defconfig
4518 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4519 encapsulate a compressed Linux kernel image with header information,
4520 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4522 * build a standard "vmlinux" kernel image (in ELF binary format):
4524 * convert the kernel into a raw binary image:
4526 ${CROSS_COMPILE}-objcopy -O binary \
4527 -R .note -R .comment \
4528 -S vmlinux linux.bin
4530 * compress the binary image:
4534 * package compressed binary image for U-Boot:
4536 mkimage -A ppc -O linux -T kernel -C gzip \
4537 -a 0 -e 0 -n "Linux Kernel Image" \
4538 -d linux.bin.gz uImage
4541 The "mkimage" tool can also be used to create ramdisk images for use
4542 with U-Boot, either separated from the Linux kernel image, or
4543 combined into one file. "mkimage" encapsulates the images with a 64
4544 byte header containing information about target architecture,
4545 operating system, image type, compression method, entry points, time
4546 stamp, CRC32 checksums, etc.
4548 "mkimage" can be called in two ways: to verify existing images and
4549 print the header information, or to build new images.
4551 In the first form (with "-l" option) mkimage lists the information
4552 contained in the header of an existing U-Boot image; this includes
4553 checksum verification:
4555 tools/mkimage -l image
4556 -l ==> list image header information
4558 The second form (with "-d" option) is used to build a U-Boot image
4559 from a "data file" which is used as image payload:
4561 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4562 -n name -d data_file image
4563 -A ==> set architecture to 'arch'
4564 -O ==> set operating system to 'os'
4565 -T ==> set image type to 'type'
4566 -C ==> set compression type 'comp'
4567 -a ==> set load address to 'addr' (hex)
4568 -e ==> set entry point to 'ep' (hex)
4569 -n ==> set image name to 'name'
4570 -d ==> use image data from 'datafile'
4572 Right now, all Linux kernels for PowerPC systems use the same load
4573 address (0x00000000), but the entry point address depends on the
4576 - 2.2.x kernels have the entry point at 0x0000000C,
4577 - 2.3.x and later kernels have the entry point at 0x00000000.
4579 So a typical call to build a U-Boot image would read:
4581 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4582 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4583 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4584 > examples/uImage.TQM850L
4585 Image Name: 2.4.4 kernel for TQM850L
4586 Created: Wed Jul 19 02:34:59 2000
4587 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4588 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4589 Load Address: 0x00000000
4590 Entry Point: 0x00000000
4592 To verify the contents of the image (or check for corruption):
4594 -> tools/mkimage -l examples/uImage.TQM850L
4595 Image Name: 2.4.4 kernel for TQM850L
4596 Created: Wed Jul 19 02:34:59 2000
4597 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4598 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4599 Load Address: 0x00000000
4600 Entry Point: 0x00000000
4602 NOTE: for embedded systems where boot time is critical you can trade
4603 speed for memory and install an UNCOMPRESSED image instead: this
4604 needs more space in Flash, but boots much faster since it does not
4605 need to be uncompressed:
4607 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4608 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4609 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4610 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4611 > examples/uImage.TQM850L-uncompressed
4612 Image Name: 2.4.4 kernel for TQM850L
4613 Created: Wed Jul 19 02:34:59 2000
4614 Image Type: PowerPC Linux Kernel Image (uncompressed)
4615 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4616 Load Address: 0x00000000
4617 Entry Point: 0x00000000
4620 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4621 when your kernel is intended to use an initial ramdisk:
4623 -> tools/mkimage -n 'Simple Ramdisk Image' \
4624 > -A ppc -O linux -T ramdisk -C gzip \
4625 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4626 Image Name: Simple Ramdisk Image
4627 Created: Wed Jan 12 14:01:50 2000
4628 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4629 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4630 Load Address: 0x00000000
4631 Entry Point: 0x00000000
4633 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4634 option performs the converse operation of the mkimage's second form (the "-d"
4635 option). Given an image built by mkimage, the dumpimage extracts a "data file"
4638 tools/dumpimage -i image -T type -p position data_file
4639 -i ==> extract from the 'image' a specific 'data_file'
4640 -T ==> set image type to 'type'
4641 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
4644 Installing a Linux Image:
4645 -------------------------
4647 To downloading a U-Boot image over the serial (console) interface,
4648 you must convert the image to S-Record format:
4650 objcopy -I binary -O srec examples/image examples/image.srec
4652 The 'objcopy' does not understand the information in the U-Boot
4653 image header, so the resulting S-Record file will be relative to
4654 address 0x00000000. To load it to a given address, you need to
4655 specify the target address as 'offset' parameter with the 'loads'
4658 Example: install the image to address 0x40100000 (which on the
4659 TQM8xxL is in the first Flash bank):
4661 => erase 40100000 401FFFFF
4667 ## Ready for S-Record download ...
4668 ~>examples/image.srec
4669 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4671 15989 15990 15991 15992
4672 [file transfer complete]
4674 ## Start Addr = 0x00000000
4677 You can check the success of the download using the 'iminfo' command;
4678 this includes a checksum verification so you can be sure no data
4679 corruption happened:
4683 ## Checking Image at 40100000 ...
4684 Image Name: 2.2.13 for initrd on TQM850L
4685 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4686 Data Size: 335725 Bytes = 327 kB = 0 MB
4687 Load Address: 00000000
4688 Entry Point: 0000000c
4689 Verifying Checksum ... OK
4695 The "bootm" command is used to boot an application that is stored in
4696 memory (RAM or Flash). In case of a Linux kernel image, the contents
4697 of the "bootargs" environment variable is passed to the kernel as
4698 parameters. You can check and modify this variable using the
4699 "printenv" and "setenv" commands:
4702 => printenv bootargs
4703 bootargs=root=/dev/ram
4705 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4707 => printenv bootargs
4708 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4711 ## Booting Linux kernel at 40020000 ...
4712 Image Name: 2.2.13 for NFS on TQM850L
4713 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4714 Data Size: 381681 Bytes = 372 kB = 0 MB
4715 Load Address: 00000000
4716 Entry Point: 0000000c
4717 Verifying Checksum ... OK
4718 Uncompressing Kernel Image ... OK
4719 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
4720 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4721 time_init: decrementer frequency = 187500000/60
4722 Calibrating delay loop... 49.77 BogoMIPS
4723 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4726 If you want to boot a Linux kernel with initial RAM disk, you pass
4727 the memory addresses of both the kernel and the initrd image (PPBCOOT
4728 format!) to the "bootm" command:
4730 => imi 40100000 40200000
4732 ## Checking Image at 40100000 ...
4733 Image Name: 2.2.13 for initrd on TQM850L
4734 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4735 Data Size: 335725 Bytes = 327 kB = 0 MB
4736 Load Address: 00000000
4737 Entry Point: 0000000c
4738 Verifying Checksum ... OK
4740 ## Checking Image at 40200000 ...
4741 Image Name: Simple Ramdisk Image
4742 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4743 Data Size: 566530 Bytes = 553 kB = 0 MB
4744 Load Address: 00000000
4745 Entry Point: 00000000
4746 Verifying Checksum ... OK
4748 => bootm 40100000 40200000
4749 ## Booting Linux kernel at 40100000 ...
4750 Image Name: 2.2.13 for initrd on TQM850L
4751 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4752 Data Size: 335725 Bytes = 327 kB = 0 MB
4753 Load Address: 00000000
4754 Entry Point: 0000000c
4755 Verifying Checksum ... OK
4756 Uncompressing Kernel Image ... OK
4757 ## Loading RAMDisk Image at 40200000 ...
4758 Image Name: Simple Ramdisk Image
4759 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4760 Data Size: 566530 Bytes = 553 kB = 0 MB
4761 Load Address: 00000000
4762 Entry Point: 00000000
4763 Verifying Checksum ... OK
4764 Loading Ramdisk ... OK
4765 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
4766 Boot arguments: root=/dev/ram
4767 time_init: decrementer frequency = 187500000/60
4768 Calibrating delay loop... 49.77 BogoMIPS
4770 RAMDISK: Compressed image found at block 0
4771 VFS: Mounted root (ext2 filesystem).
4775 Boot Linux and pass a flat device tree:
4778 First, U-Boot must be compiled with the appropriate defines. See the section
4779 titled "Linux Kernel Interface" above for a more in depth explanation. The
4780 following is an example of how to start a kernel and pass an updated
4786 oft=oftrees/mpc8540ads.dtb
4787 => tftp $oftaddr $oft
4788 Speed: 1000, full duplex
4790 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4791 Filename 'oftrees/mpc8540ads.dtb'.
4792 Load address: 0x300000
4795 Bytes transferred = 4106 (100a hex)
4796 => tftp $loadaddr $bootfile
4797 Speed: 1000, full duplex
4799 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4801 Load address: 0x200000
4802 Loading:############
4804 Bytes transferred = 1029407 (fb51f hex)
4809 => bootm $loadaddr - $oftaddr
4810 ## Booting image at 00200000 ...
4811 Image Name: Linux-2.6.17-dirty
4812 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4813 Data Size: 1029343 Bytes = 1005.2 kB
4814 Load Address: 00000000
4815 Entry Point: 00000000
4816 Verifying Checksum ... OK
4817 Uncompressing Kernel Image ... OK
4818 Booting using flat device tree at 0x300000
4819 Using MPC85xx ADS machine description
4820 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4824 More About U-Boot Image Types:
4825 ------------------------------
4827 U-Boot supports the following image types:
4829 "Standalone Programs" are directly runnable in the environment
4830 provided by U-Boot; it is expected that (if they behave
4831 well) you can continue to work in U-Boot after return from
4832 the Standalone Program.
4833 "OS Kernel Images" are usually images of some Embedded OS which
4834 will take over control completely. Usually these programs
4835 will install their own set of exception handlers, device
4836 drivers, set up the MMU, etc. - this means, that you cannot
4837 expect to re-enter U-Boot except by resetting the CPU.
4838 "RAMDisk Images" are more or less just data blocks, and their
4839 parameters (address, size) are passed to an OS kernel that is
4841 "Multi-File Images" contain several images, typically an OS
4842 (Linux) kernel image and one or more data images like
4843 RAMDisks. This construct is useful for instance when you want
4844 to boot over the network using BOOTP etc., where the boot
4845 server provides just a single image file, but you want to get
4846 for instance an OS kernel and a RAMDisk image.
4848 "Multi-File Images" start with a list of image sizes, each
4849 image size (in bytes) specified by an "uint32_t" in network
4850 byte order. This list is terminated by an "(uint32_t)0".
4851 Immediately after the terminating 0 follow the images, one by
4852 one, all aligned on "uint32_t" boundaries (size rounded up to
4853 a multiple of 4 bytes).
4855 "Firmware Images" are binary images containing firmware (like
4856 U-Boot or FPGA images) which usually will be programmed to
4859 "Script files" are command sequences that will be executed by
4860 U-Boot's command interpreter; this feature is especially
4861 useful when you configure U-Boot to use a real shell (hush)
4862 as command interpreter.
4864 Booting the Linux zImage:
4865 -------------------------
4867 On some platforms, it's possible to boot Linux zImage. This is done
4868 using the "bootz" command. The syntax of "bootz" command is the same
4869 as the syntax of "bootm" command.
4871 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
4872 kernel with raw initrd images. The syntax is slightly different, the
4873 address of the initrd must be augmented by it's size, in the following
4874 format: "<initrd addres>:<initrd size>".
4880 One of the features of U-Boot is that you can dynamically load and
4881 run "standalone" applications, which can use some resources of
4882 U-Boot like console I/O functions or interrupt services.
4884 Two simple examples are included with the sources:
4889 'examples/hello_world.c' contains a small "Hello World" Demo
4890 application; it is automatically compiled when you build U-Boot.
4891 It's configured to run at address 0x00040004, so you can play with it
4895 ## Ready for S-Record download ...
4896 ~>examples/hello_world.srec
4897 1 2 3 4 5 6 7 8 9 10 11 ...
4898 [file transfer complete]
4900 ## Start Addr = 0x00040004
4902 => go 40004 Hello World! This is a test.
4903 ## Starting application at 0x00040004 ...
4914 Hit any key to exit ...
4916 ## Application terminated, rc = 0x0
4918 Another example, which demonstrates how to register a CPM interrupt
4919 handler with the U-Boot code, can be found in 'examples/timer.c'.
4920 Here, a CPM timer is set up to generate an interrupt every second.
4921 The interrupt service routine is trivial, just printing a '.'
4922 character, but this is just a demo program. The application can be
4923 controlled by the following keys:
4925 ? - print current values og the CPM Timer registers
4926 b - enable interrupts and start timer
4927 e - stop timer and disable interrupts
4928 q - quit application
4931 ## Ready for S-Record download ...
4932 ~>examples/timer.srec
4933 1 2 3 4 5 6 7 8 9 10 11 ...
4934 [file transfer complete]
4936 ## Start Addr = 0x00040004
4939 ## Starting application at 0x00040004 ...
4942 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4945 [q, b, e, ?] Set interval 1000000 us
4948 [q, b, e, ?] ........
4949 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4952 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4955 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4958 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4960 [q, b, e, ?] ...Stopping timer
4962 [q, b, e, ?] ## Application terminated, rc = 0x0
4968 Over time, many people have reported problems when trying to use the
4969 "minicom" terminal emulation program for serial download. I (wd)
4970 consider minicom to be broken, and recommend not to use it. Under
4971 Unix, I recommend to use C-Kermit for general purpose use (and
4972 especially for kermit binary protocol download ("loadb" command), and
4973 use "cu" for S-Record download ("loads" command). See
4974 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4975 for help with kermit.
4978 Nevertheless, if you absolutely want to use it try adding this
4979 configuration to your "File transfer protocols" section:
4981 Name Program Name U/D FullScr IO-Red. Multi
4982 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4983 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4989 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4990 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4992 Building requires a cross environment; it is known to work on
4993 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4994 need gmake since the Makefiles are not compatible with BSD make).
4995 Note that the cross-powerpc package does not install include files;
4996 attempting to build U-Boot will fail because <machine/ansi.h> is
4997 missing. This file has to be installed and patched manually:
4999 # cd /usr/pkg/cross/powerpc-netbsd/include
5001 # ln -s powerpc machine
5002 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5003 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5005 Native builds *don't* work due to incompatibilities between native
5006 and U-Boot include files.
5008 Booting assumes that (the first part of) the image booted is a
5009 stage-2 loader which in turn loads and then invokes the kernel
5010 proper. Loader sources will eventually appear in the NetBSD source
5011 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5012 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5015 Implementation Internals:
5016 =========================
5018 The following is not intended to be a complete description of every
5019 implementation detail. However, it should help to understand the
5020 inner workings of U-Boot and make it easier to port it to custom
5024 Initial Stack, Global Data:
5025 ---------------------------
5027 The implementation of U-Boot is complicated by the fact that U-Boot
5028 starts running out of ROM (flash memory), usually without access to
5029 system RAM (because the memory controller is not initialized yet).
5030 This means that we don't have writable Data or BSS segments, and BSS
5031 is not initialized as zero. To be able to get a C environment working
5032 at all, we have to allocate at least a minimal stack. Implementation
5033 options for this are defined and restricted by the CPU used: Some CPU
5034 models provide on-chip memory (like the IMMR area on MPC8xx and
5035 MPC826x processors), on others (parts of) the data cache can be
5036 locked as (mis-) used as memory, etc.
5038 Chris Hallinan posted a good summary of these issues to the
5039 U-Boot mailing list:
5041 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5042 From: "Chris Hallinan" <clh@net1plus.com>
5043 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5046 Correct me if I'm wrong, folks, but the way I understand it
5047 is this: Using DCACHE as initial RAM for Stack, etc, does not
5048 require any physical RAM backing up the cache. The cleverness
5049 is that the cache is being used as a temporary supply of
5050 necessary storage before the SDRAM controller is setup. It's
5051 beyond the scope of this list to explain the details, but you
5052 can see how this works by studying the cache architecture and
5053 operation in the architecture and processor-specific manuals.
5055 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5056 is another option for the system designer to use as an
5057 initial stack/RAM area prior to SDRAM being available. Either
5058 option should work for you. Using CS 4 should be fine if your
5059 board designers haven't used it for something that would
5060 cause you grief during the initial boot! It is frequently not
5063 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5064 with your processor/board/system design. The default value
5065 you will find in any recent u-boot distribution in
5066 walnut.h should work for you. I'd set it to a value larger
5067 than your SDRAM module. If you have a 64MB SDRAM module, set
5068 it above 400_0000. Just make sure your board has no resources
5069 that are supposed to respond to that address! That code in
5070 start.S has been around a while and should work as is when
5071 you get the config right.
5076 It is essential to remember this, since it has some impact on the C
5077 code for the initialization procedures:
5079 * Initialized global data (data segment) is read-only. Do not attempt
5082 * Do not use any uninitialized global data (or implicitly initialized
5083 as zero data - BSS segment) at all - this is undefined, initiali-
5084 zation is performed later (when relocating to RAM).
5086 * Stack space is very limited. Avoid big data buffers or things like
5089 Having only the stack as writable memory limits means we cannot use
5090 normal global data to share information between the code. But it
5091 turned out that the implementation of U-Boot can be greatly
5092 simplified by making a global data structure (gd_t) available to all
5093 functions. We could pass a pointer to this data as argument to _all_
5094 functions, but this would bloat the code. Instead we use a feature of
5095 the GCC compiler (Global Register Variables) to share the data: we
5096 place a pointer (gd) to the global data into a register which we
5097 reserve for this purpose.
5099 When choosing a register for such a purpose we are restricted by the
5100 relevant (E)ABI specifications for the current architecture, and by
5101 GCC's implementation.
5103 For PowerPC, the following registers have specific use:
5105 R2: reserved for system use
5106 R3-R4: parameter passing and return values
5107 R5-R10: parameter passing
5108 R13: small data area pointer
5112 (U-Boot also uses R12 as internal GOT pointer. r12
5113 is a volatile register so r12 needs to be reset when
5114 going back and forth between asm and C)
5116 ==> U-Boot will use R2 to hold a pointer to the global data
5118 Note: on PPC, we could use a static initializer (since the
5119 address of the global data structure is known at compile time),
5120 but it turned out that reserving a register results in somewhat
5121 smaller code - although the code savings are not that big (on
5122 average for all boards 752 bytes for the whole U-Boot image,
5123 624 text + 127 data).
5125 On ARM, the following registers are used:
5127 R0: function argument word/integer result
5128 R1-R3: function argument word
5129 R9: platform specific
5130 R10: stack limit (used only if stack checking is enabled)
5131 R11: argument (frame) pointer
5132 R12: temporary workspace
5135 R15: program counter
5137 ==> U-Boot will use R9 to hold a pointer to the global data
5139 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5141 On Nios II, the ABI is documented here:
5142 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5144 ==> U-Boot will use gp to hold a pointer to the global data
5146 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5147 to access small data sections, so gp is free.
5149 On NDS32, the following registers are used:
5151 R0-R1: argument/return
5153 R15: temporary register for assembler
5154 R16: trampoline register
5155 R28: frame pointer (FP)
5156 R29: global pointer (GP)
5157 R30: link register (LP)
5158 R31: stack pointer (SP)
5159 PC: program counter (PC)
5161 ==> U-Boot will use R10 to hold a pointer to the global data
5163 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5164 or current versions of GCC may "optimize" the code too much.
5169 U-Boot runs in system state and uses physical addresses, i.e. the
5170 MMU is not used either for address mapping nor for memory protection.
5172 The available memory is mapped to fixed addresses using the memory
5173 controller. In this process, a contiguous block is formed for each
5174 memory type (Flash, SDRAM, SRAM), even when it consists of several
5175 physical memory banks.
5177 U-Boot is installed in the first 128 kB of the first Flash bank (on
5178 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5179 booting and sizing and initializing DRAM, the code relocates itself
5180 to the upper end of DRAM. Immediately below the U-Boot code some
5181 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5182 configuration setting]. Below that, a structure with global Board
5183 Info data is placed, followed by the stack (growing downward).
5185 Additionally, some exception handler code is copied to the low 8 kB
5186 of DRAM (0x00000000 ... 0x00001FFF).
5188 So a typical memory configuration with 16 MB of DRAM could look like
5191 0x0000 0000 Exception Vector code
5194 0x0000 2000 Free for Application Use
5200 0x00FB FF20 Monitor Stack (Growing downward)
5201 0x00FB FFAC Board Info Data and permanent copy of global data
5202 0x00FC 0000 Malloc Arena
5205 0x00FE 0000 RAM Copy of Monitor Code
5206 ... eventually: LCD or video framebuffer
5207 ... eventually: pRAM (Protected RAM - unchanged by reset)
5208 0x00FF FFFF [End of RAM]
5211 System Initialization:
5212 ----------------------
5214 In the reset configuration, U-Boot starts at the reset entry point
5215 (on most PowerPC systems at address 0x00000100). Because of the reset
5216 configuration for CS0# this is a mirror of the on board Flash memory.
5217 To be able to re-map memory U-Boot then jumps to its link address.
5218 To be able to implement the initialization code in C, a (small!)
5219 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5220 which provide such a feature like), or in a locked part of the data
5221 cache. After that, U-Boot initializes the CPU core, the caches and
5224 Next, all (potentially) available memory banks are mapped using a
5225 preliminary mapping. For example, we put them on 512 MB boundaries
5226 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5227 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5228 programmed for SDRAM access. Using the temporary configuration, a
5229 simple memory test is run that determines the size of the SDRAM
5232 When there is more than one SDRAM bank, and the banks are of
5233 different size, the largest is mapped first. For equal size, the first
5234 bank (CS2#) is mapped first. The first mapping is always for address
5235 0x00000000, with any additional banks following immediately to create
5236 contiguous memory starting from 0.
5238 Then, the monitor installs itself at the upper end of the SDRAM area
5239 and allocates memory for use by malloc() and for the global Board
5240 Info data; also, the exception vector code is copied to the low RAM
5241 pages, and the final stack is set up.
5243 Only after this relocation will you have a "normal" C environment;
5244 until that you are restricted in several ways, mostly because you are
5245 running from ROM, and because the code will have to be relocated to a
5249 U-Boot Porting Guide:
5250 ----------------------
5252 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5256 int main(int argc, char *argv[])
5258 sighandler_t no_more_time;
5260 signal(SIGALRM, no_more_time);
5261 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5263 if (available_money > available_manpower) {
5264 Pay consultant to port U-Boot;
5268 Download latest U-Boot source;
5270 Subscribe to u-boot mailing list;
5273 email("Hi, I am new to U-Boot, how do I get started?");
5276 Read the README file in the top level directory;
5277 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5278 Read applicable doc/*.README;
5279 Read the source, Luke;
5280 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5283 if (available_money > toLocalCurrency ($2500))
5286 Add a lot of aggravation and time;
5288 if (a similar board exists) { /* hopefully... */
5289 cp -a board/<similar> board/<myboard>
5290 cp include/configs/<similar>.h include/configs/<myboard>.h
5292 Create your own board support subdirectory;
5293 Create your own board include/configs/<myboard>.h file;
5295 Edit new board/<myboard> files
5296 Edit new include/configs/<myboard>.h
5301 Add / modify source code;
5305 email("Hi, I am having problems...");
5307 Send patch file to the U-Boot email list;
5308 if (reasonable critiques)
5309 Incorporate improvements from email list code review;
5311 Defend code as written;
5317 void no_more_time (int sig)
5326 All contributions to U-Boot should conform to the Linux kernel
5327 coding style; see the file "Documentation/CodingStyle" and the script
5328 "scripts/Lindent" in your Linux kernel source directory.
5330 Source files originating from a different project (for example the
5331 MTD subsystem) are generally exempt from these guidelines and are not
5332 reformatted to ease subsequent migration to newer versions of those
5335 Please note that U-Boot is implemented in C (and to some small parts in
5336 Assembler); no C++ is used, so please do not use C++ style comments (//)
5339 Please also stick to the following formatting rules:
5340 - remove any trailing white space
5341 - use TAB characters for indentation and vertical alignment, not spaces
5342 - make sure NOT to use DOS '\r\n' line feeds
5343 - do not add more than 2 consecutive empty lines to source files
5344 - do not add trailing empty lines to source files
5346 Submissions which do not conform to the standards may be returned
5347 with a request to reformat the changes.
5353 Since the number of patches for U-Boot is growing, we need to
5354 establish some rules. Submissions which do not conform to these rules
5355 may be rejected, even when they contain important and valuable stuff.
5357 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5359 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5360 see http://lists.denx.de/mailman/listinfo/u-boot
5362 When you send a patch, please include the following information with
5365 * For bug fixes: a description of the bug and how your patch fixes
5366 this bug. Please try to include a way of demonstrating that the
5367 patch actually fixes something.
5369 * For new features: a description of the feature and your
5372 * A CHANGELOG entry as plaintext (separate from the patch)
5374 * For major contributions, add a MAINTAINERS file with your
5375 information and associated file and directory references.
5377 * When you add support for a new board, don't forget to add a
5378 maintainer e-mail address to the boards.cfg file, too.
5380 * If your patch adds new configuration options, don't forget to
5381 document these in the README file.
5383 * The patch itself. If you are using git (which is *strongly*
5384 recommended) you can easily generate the patch using the
5385 "git format-patch". If you then use "git send-email" to send it to
5386 the U-Boot mailing list, you will avoid most of the common problems
5387 with some other mail clients.
5389 If you cannot use git, use "diff -purN OLD NEW". If your version of
5390 diff does not support these options, then get the latest version of
5393 The current directory when running this command shall be the parent
5394 directory of the U-Boot source tree (i. e. please make sure that
5395 your patch includes sufficient directory information for the
5398 We prefer patches as plain text. MIME attachments are discouraged,
5399 and compressed attachments must not be used.
5401 * If one logical set of modifications affects or creates several
5402 files, all these changes shall be submitted in a SINGLE patch file.
5404 * Changesets that contain different, unrelated modifications shall be
5405 submitted as SEPARATE patches, one patch per changeset.
5410 * Before sending the patch, run the buildman script on your patched
5411 source tree and make sure that no errors or warnings are reported
5412 for any of the boards.
5414 * Keep your modifications to the necessary minimum: A patch
5415 containing several unrelated changes or arbitrary reformats will be
5416 returned with a request to re-formatting / split it.
5418 * If you modify existing code, make sure that your new code does not
5419 add to the memory footprint of the code ;-) Small is beautiful!
5420 When adding new features, these should compile conditionally only
5421 (using #ifdef), and the resulting code with the new feature
5422 disabled must not need more memory than the old code without your
5425 * Remember that there is a size limit of 100 kB per message on the
5426 u-boot mailing list. Bigger patches will be moderated. If they are
5427 reasonable and not too big, they will be acknowledged. But patches
5428 bigger than the size limit should be avoided.