2 # (C) Copyright 2000 - 2013
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
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_NAND * NAND support
814 CONFIG_CMD_NET bootp, tftpboot, rarpboot
815 CONFIG_CMD_NFS NFS support
816 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
817 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
818 CONFIG_CMD_PCI * pciinfo
819 CONFIG_CMD_PCMCIA * PCMCIA support
820 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
822 CONFIG_CMD_PORTIO * Port I/O
823 CONFIG_CMD_READ * Read raw data from partition
824 CONFIG_CMD_REGINFO * Register dump
825 CONFIG_CMD_RUN run command in env variable
826 CONFIG_CMD_SANDBOX * sb command to access sandbox features
827 CONFIG_CMD_SAVES * save S record dump
828 CONFIG_CMD_SDRAM * print SDRAM configuration information
829 (requires CONFIG_CMD_I2C)
830 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
831 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
832 CONFIG_CMD_SOURCE "source" command Support
833 CONFIG_CMD_SPI * SPI serial bus support
834 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
835 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
836 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
837 CONFIG_CMD_TIMER * access to the system tick timer
838 CONFIG_CMD_USB * USB support
839 CONFIG_CMD_CDP * Cisco Discover Protocol support
840 CONFIG_CMD_MFSL * Microblaze FSL support
841 CONFIG_CMD_XIMG Load part of Multi Image
842 CONFIG_CMD_UUID * Generate random UUID or GUID string
844 EXAMPLE: If you want all functions except of network
845 support you can write:
847 #include "config_cmd_all.h"
848 #undef CONFIG_CMD_NET
851 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
853 Note: Don't enable the "icache" and "dcache" commands
854 (configuration option CONFIG_CMD_CACHE) unless you know
855 what you (and your U-Boot users) are doing. Data
856 cache cannot be enabled on systems like the
857 8xx (where accesses to the IMMR region must be
858 uncached), and it cannot be disabled on all other
859 systems where we (mis-) use the data cache to hold an
860 initial stack and some data.
863 XXX - this list needs to get updated!
865 - Removal of commands
866 If no commands are needed to boot, you can disable
867 CONFIG_CMDLINE to remove them. In this case, the command line
868 will not be available, and when U-Boot wants to execute the
869 boot command (on start-up) it will call board_run_command()
870 instead. This can reduce image size significantly for very
871 simple boot procedures.
873 - Regular expression support:
875 If this variable is defined, U-Boot is linked against
876 the SLRE (Super Light Regular Expression) library,
877 which adds regex support to some commands, as for
878 example "env grep" and "setexpr".
882 If this variable is defined, U-Boot will use a device tree
883 to configure its devices, instead of relying on statically
884 compiled #defines in the board file. This option is
885 experimental and only available on a few boards. The device
886 tree is available in the global data as gd->fdt_blob.
888 U-Boot needs to get its device tree from somewhere. This can
889 be done using one of the three options below:
892 If this variable is defined, U-Boot will embed a device tree
893 binary in its image. This device tree file should be in the
894 board directory and called <soc>-<board>.dts. The binary file
895 is then picked up in board_init_f() and made available through
896 the global data structure as gd->blob.
899 If this variable is defined, U-Boot will build a device tree
900 binary. It will be called u-boot.dtb. Architecture-specific
901 code will locate it at run-time. Generally this works by:
903 cat u-boot.bin u-boot.dtb >image.bin
905 and in fact, U-Boot does this for you, creating a file called
906 u-boot-dtb.bin which is useful in the common case. You can
907 still use the individual files if you need something more
911 If this variable is defined, U-Boot will use the device tree
912 provided by the board at runtime instead of embedding one with
913 the image. Only boards defining board_fdt_blob_setup() support
914 this option (see include/fdtdec.h file).
918 If this variable is defined, it enables watchdog
919 support for the SoC. There must be support in the SoC
920 specific code for a watchdog. For the 8xx
921 CPUs, the SIU Watchdog feature is enabled in the SYPCR
922 register. When supported for a specific SoC is
923 available, then no further board specific code should
927 When using a watchdog circuitry external to the used
928 SoC, then define this variable and provide board
929 specific code for the "hw_watchdog_reset" function.
931 CONFIG_AT91_HW_WDT_TIMEOUT
932 specify the timeout in seconds. default 2 seconds.
935 CONFIG_VERSION_VARIABLE
936 If this variable is defined, an environment variable
937 named "ver" is created by U-Boot showing the U-Boot
938 version as printed by the "version" command.
939 Any change to this variable will be reverted at the
944 When CONFIG_CMD_DATE is selected, the type of the RTC
945 has to be selected, too. Define exactly one of the
948 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
949 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
950 CONFIG_RTC_MC146818 - use MC146818 RTC
951 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
952 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
953 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
954 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
955 CONFIG_RTC_DS164x - use Dallas DS164x RTC
956 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
957 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
958 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
959 CONFIG_SYS_RV3029_TCR - enable trickle charger on
962 Note that if the RTC uses I2C, then the I2C interface
963 must also be configured. See I2C Support, below.
966 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
968 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
969 chip-ngpio pairs that tell the PCA953X driver the number of
970 pins supported by a particular chip.
972 Note that if the GPIO device uses I2C, then the I2C interface
973 must also be configured. See I2C Support, below.
976 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
977 accesses and can checksum them or write a list of them out
978 to memory. See the 'iotrace' command for details. This is
979 useful for testing device drivers since it can confirm that
980 the driver behaves the same way before and after a code
981 change. Currently this is supported on sandbox and arm. To
982 add support for your architecture, add '#include <iotrace.h>'
983 to the bottom of arch/<arch>/include/asm/io.h and test.
985 Example output from the 'iotrace stats' command is below.
986 Note that if the trace buffer is exhausted, the checksum will
987 still continue to operate.
990 Start: 10000000 (buffer start address)
991 Size: 00010000 (buffer size)
992 Offset: 00000120 (current buffer offset)
993 Output: 10000120 (start + offset)
994 Count: 00000018 (number of trace records)
995 CRC32: 9526fb66 (CRC32 of all trace records)
999 When CONFIG_TIMESTAMP is selected, the timestamp
1000 (date and time) of an image is printed by image
1001 commands like bootm or iminfo. This option is
1002 automatically enabled when you select CONFIG_CMD_DATE .
1004 - Partition Labels (disklabels) Supported:
1005 Zero or more of the following:
1006 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1007 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1008 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1009 bootloader. Note 2TB partition limit; see
1011 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1013 If IDE or SCSI support is enabled (CONFIG_IDE or
1014 CONFIG_SCSI) you must configure support for at
1015 least one non-MTD partition type as well.
1018 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1019 board configurations files but used nowhere!
1021 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1022 be performed by calling the function
1023 ide_set_reset(int reset)
1024 which has to be defined in a board specific file
1029 Set this to enable ATAPI support.
1034 Set this to enable support for disks larger than 137GB
1035 Also look at CONFIG_SYS_64BIT_LBA.
1036 Whithout these , LBA48 support uses 32bit variables and will 'only'
1037 support disks up to 2.1TB.
1039 CONFIG_SYS_64BIT_LBA:
1040 When enabled, makes the IDE subsystem use 64bit sector addresses.
1044 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1045 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1046 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1047 maximum numbers of LUNs, SCSI ID's and target
1050 The environment variable 'scsidevs' is set to the number of
1051 SCSI devices found during the last scan.
1053 - NETWORK Support (PCI):
1055 Support for Intel 8254x/8257x gigabit chips.
1058 Utility code for direct access to the SPI bus on Intel 8257x.
1059 This does not do anything useful unless you set at least one
1060 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1062 CONFIG_E1000_SPI_GENERIC
1063 Allow generic access to the SPI bus on the Intel 8257x, for
1064 example with the "sspi" command.
1067 Management command for E1000 devices. When used on devices
1068 with SPI support you can reprogram the EEPROM from U-Boot.
1071 Support for Intel 82557/82559/82559ER chips.
1072 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1073 write routine for first time initialisation.
1076 Support for Digital 2114x chips.
1077 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1078 modem chip initialisation (KS8761/QS6611).
1081 Support for National dp83815 chips.
1084 Support for National dp8382[01] gigabit chips.
1086 - NETWORK Support (other):
1088 CONFIG_DRIVER_AT91EMAC
1089 Support for AT91RM9200 EMAC.
1092 Define this to use reduced MII inteface
1094 CONFIG_DRIVER_AT91EMAC_QUIET
1095 If this defined, the driver is quiet.
1096 The driver doen't show link status messages.
1098 CONFIG_CALXEDA_XGMAC
1099 Support for the Calxeda XGMAC device
1102 Support for SMSC's LAN91C96 chips.
1104 CONFIG_LAN91C96_USE_32_BIT
1105 Define this to enable 32 bit addressing
1108 Support for SMSC's LAN91C111 chip
1110 CONFIG_SMC91111_BASE
1111 Define this to hold the physical address
1112 of the device (I/O space)
1114 CONFIG_SMC_USE_32_BIT
1115 Define this if data bus is 32 bits
1117 CONFIG_SMC_USE_IOFUNCS
1118 Define this to use i/o functions instead of macros
1119 (some hardware wont work with macros)
1121 CONFIG_DRIVER_TI_EMAC
1122 Support for davinci emac
1124 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1125 Define this if you have more then 3 PHYs.
1128 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1130 CONFIG_FTGMAC100_EGIGA
1131 Define this to use GE link update with gigabit PHY.
1132 Define this if FTGMAC100 is connected to gigabit PHY.
1133 If your system has 10/100 PHY only, it might not occur
1134 wrong behavior. Because PHY usually return timeout or
1135 useless data when polling gigabit status and gigabit
1136 control registers. This behavior won't affect the
1137 correctnessof 10/100 link speed update.
1140 Support for SMSC's LAN911x and LAN921x chips
1143 Define this to hold the physical address
1144 of the device (I/O space)
1146 CONFIG_SMC911X_32_BIT
1147 Define this if data bus is 32 bits
1149 CONFIG_SMC911X_16_BIT
1150 Define this if data bus is 16 bits. If your processor
1151 automatically converts one 32 bit word to two 16 bit
1152 words you may also try CONFIG_SMC911X_32_BIT.
1155 Support for Renesas on-chip Ethernet controller
1157 CONFIG_SH_ETHER_USE_PORT
1158 Define the number of ports to be used
1160 CONFIG_SH_ETHER_PHY_ADDR
1161 Define the ETH PHY's address
1163 CONFIG_SH_ETHER_CACHE_WRITEBACK
1164 If this option is set, the driver enables cache flush.
1168 Support for PWM module on the imx6.
1172 Support TPM devices.
1174 CONFIG_TPM_TIS_INFINEON
1175 Support for Infineon i2c bus TPM devices. Only one device
1176 per system is supported at this time.
1178 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1179 Define the burst count bytes upper limit
1182 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1184 CONFIG_TPM_ST33ZP24_I2C
1185 Support for STMicroelectronics ST33ZP24 I2C devices.
1186 Requires TPM_ST33ZP24 and I2C.
1188 CONFIG_TPM_ST33ZP24_SPI
1189 Support for STMicroelectronics ST33ZP24 SPI devices.
1190 Requires TPM_ST33ZP24 and SPI.
1192 CONFIG_TPM_ATMEL_TWI
1193 Support for Atmel TWI TPM device. Requires I2C support.
1196 Support for generic parallel port TPM devices. Only one device
1197 per system is supported at this time.
1199 CONFIG_TPM_TIS_BASE_ADDRESS
1200 Base address where the generic TPM device is mapped
1201 to. Contemporary x86 systems usually map it at
1205 Add tpm monitor functions.
1206 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1207 provides monitor access to authorized functions.
1210 Define this to enable the TPM support library which provides
1211 functional interfaces to some TPM commands.
1212 Requires support for a TPM device.
1214 CONFIG_TPM_AUTH_SESSIONS
1215 Define this to enable authorized functions in the TPM library.
1216 Requires CONFIG_TPM and CONFIG_SHA1.
1219 At the moment only the UHCI host controller is
1220 supported (PIP405, MIP405); define
1221 CONFIG_USB_UHCI to enable it.
1222 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1223 and define CONFIG_USB_STORAGE to enable the USB
1226 Supported are USB Keyboards and USB Floppy drives
1229 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1230 txfilltuning field in the EHCI controller on reset.
1232 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1233 HW module registers.
1236 Define the below if you wish to use the USB console.
1237 Once firmware is rebuilt from a serial console issue the
1238 command "setenv stdin usbtty; setenv stdout usbtty" and
1239 attach your USB cable. The Unix command "dmesg" should print
1240 it has found a new device. The environment variable usbtty
1241 can be set to gserial or cdc_acm to enable your device to
1242 appear to a USB host as a Linux gserial device or a
1243 Common Device Class Abstract Control Model serial device.
1244 If you select usbtty = gserial you should be able to enumerate
1246 # modprobe usbserial vendor=0xVendorID product=0xProductID
1247 else if using cdc_acm, simply setting the environment
1248 variable usbtty to be cdc_acm should suffice. The following
1249 might be defined in YourBoardName.h
1252 Define this to build a UDC device
1255 Define this to have a tty type of device available to
1256 talk to the UDC device
1259 Define this to enable the high speed support for usb
1260 device and usbtty. If this feature is enabled, a routine
1261 int is_usbd_high_speed(void)
1262 also needs to be defined by the driver to dynamically poll
1263 whether the enumeration has succeded at high speed or full
1266 CONFIG_SYS_CONSOLE_IS_IN_ENV
1267 Define this if you want stdin, stdout &/or stderr to
1270 If you have a USB-IF assigned VendorID then you may wish to
1271 define your own vendor specific values either in BoardName.h
1272 or directly in usbd_vendor_info.h. If you don't define
1273 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1274 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1275 should pretend to be a Linux device to it's target host.
1277 CONFIG_USBD_MANUFACTURER
1278 Define this string as the name of your company for
1279 - CONFIG_USBD_MANUFACTURER "my company"
1281 CONFIG_USBD_PRODUCT_NAME
1282 Define this string as the name of your product
1283 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1285 CONFIG_USBD_VENDORID
1286 Define this as your assigned Vendor ID from the USB
1287 Implementors Forum. This *must* be a genuine Vendor ID
1288 to avoid polluting the USB namespace.
1289 - CONFIG_USBD_VENDORID 0xFFFF
1291 CONFIG_USBD_PRODUCTID
1292 Define this as the unique Product ID
1294 - CONFIG_USBD_PRODUCTID 0xFFFF
1296 - ULPI Layer Support:
1297 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1298 the generic ULPI layer. The generic layer accesses the ULPI PHY
1299 via the platform viewport, so you need both the genric layer and
1300 the viewport enabled. Currently only Chipidea/ARC based
1301 viewport is supported.
1302 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1303 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1304 If your ULPI phy needs a different reference clock than the
1305 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1306 the appropriate value in Hz.
1309 The MMC controller on the Intel PXA is supported. To
1310 enable this define CONFIG_MMC. The MMC can be
1311 accessed from the boot prompt by mapping the device
1312 to physical memory similar to flash. Command line is
1313 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1314 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1317 Support for Renesas on-chip MMCIF controller
1319 CONFIG_SH_MMCIF_ADDR
1320 Define the base address of MMCIF registers
1323 Define the clock frequency for MMCIF
1325 CONFIG_SUPPORT_EMMC_BOOT
1326 Enable some additional features of the eMMC boot partitions.
1328 CONFIG_SUPPORT_EMMC_RPMB
1329 Enable the commands for reading, writing and programming the
1330 key for the Replay Protection Memory Block partition in eMMC.
1332 - USB Device Firmware Update (DFU) class support:
1333 CONFIG_USB_FUNCTION_DFU
1334 This enables the USB portion of the DFU USB class
1337 This enables the command "dfu" which is used to have
1338 U-Boot create a DFU class device via USB. This command
1339 requires that the "dfu_alt_info" environment variable be
1340 set and define the alt settings to expose to the host.
1343 This enables support for exposing (e)MMC devices via DFU.
1346 This enables support for exposing NAND devices via DFU.
1349 This enables support for exposing RAM via DFU.
1350 Note: DFU spec refer to non-volatile memory usage, but
1351 allow usages beyond the scope of spec - here RAM usage,
1352 one that would help mostly the developer.
1354 CONFIG_SYS_DFU_DATA_BUF_SIZE
1355 Dfu transfer uses a buffer before writing data to the
1356 raw storage device. Make the size (in bytes) of this buffer
1357 configurable. The size of this buffer is also configurable
1358 through the "dfu_bufsiz" environment variable.
1360 CONFIG_SYS_DFU_MAX_FILE_SIZE
1361 When updating files rather than the raw storage device,
1362 we use a static buffer to copy the file into and then write
1363 the buffer once we've been given the whole file. Define
1364 this to the maximum filesize (in bytes) for the buffer.
1365 Default is 4 MiB if undefined.
1367 DFU_DEFAULT_POLL_TIMEOUT
1368 Poll timeout [ms], is the timeout a device can send to the
1369 host. The host must wait for this timeout before sending
1370 a subsequent DFU_GET_STATUS request to the device.
1372 DFU_MANIFEST_POLL_TIMEOUT
1373 Poll timeout [ms], which the device sends to the host when
1374 entering dfuMANIFEST state. Host waits this timeout, before
1375 sending again an USB request to the device.
1377 - USB Device Android Fastboot support:
1378 CONFIG_USB_FUNCTION_FASTBOOT
1379 This enables the USB part of the fastboot gadget
1382 This enables the command "fastboot" which enables the Android
1383 fastboot mode for the platform's USB device. Fastboot is a USB
1384 protocol for downloading images, flashing and device control
1385 used on Android devices.
1386 See doc/README.android-fastboot for more information.
1388 CONFIG_ANDROID_BOOT_IMAGE
1389 This enables support for booting images which use the Android
1390 image format header.
1392 CONFIG_FASTBOOT_BUF_ADDR
1393 The fastboot protocol requires a large memory buffer for
1394 downloads. Define this to the starting RAM address to use for
1397 CONFIG_FASTBOOT_BUF_SIZE
1398 The fastboot protocol requires a large memory buffer for
1399 downloads. This buffer should be as large as possible for a
1400 platform. Define this to the size available RAM for fastboot.
1402 CONFIG_FASTBOOT_FLASH
1403 The fastboot protocol includes a "flash" command for writing
1404 the downloaded image to a non-volatile storage device. Define
1405 this to enable the "fastboot flash" command.
1407 CONFIG_FASTBOOT_FLASH_MMC_DEV
1408 The fastboot "flash" command requires additional information
1409 regarding the non-volatile storage device. Define this to
1410 the eMMC device that fastboot should use to store the image.
1412 CONFIG_FASTBOOT_GPT_NAME
1413 The fastboot "flash" command supports writing the downloaded
1414 image to the Protective MBR and the Primary GUID Partition
1415 Table. (Additionally, this downloaded image is post-processed
1416 to generate and write the Backup GUID Partition Table.)
1417 This occurs when the specified "partition name" on the
1418 "fastboot flash" command line matches this value.
1419 The default is "gpt" if undefined.
1421 CONFIG_FASTBOOT_MBR_NAME
1422 The fastboot "flash" command supports writing the downloaded
1424 This occurs when the "partition name" specified on the
1425 "fastboot flash" command line matches this value.
1426 If not defined the default value "mbr" is used.
1428 - Journaling Flash filesystem support:
1430 Define these for a default partition on a NAND device
1432 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1433 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1434 Define these for a default partition on a NOR device
1437 See Kconfig help for available keyboard drivers.
1441 Define this to enable a custom keyboard support.
1442 This simply calls drv_keyboard_init() which must be
1443 defined in your board-specific files. This option is deprecated
1444 and is only used by novena. For new boards, use driver model
1449 Enable the Freescale DIU video driver. Reference boards for
1450 SOCs that have a DIU should define this macro to enable DIU
1451 support, and should also define these other macros:
1456 CONFIG_VIDEO_SW_CURSOR
1457 CONFIG_VGA_AS_SINGLE_DEVICE
1459 CONFIG_VIDEO_BMP_LOGO
1461 The DIU driver will look for the 'video-mode' environment
1462 variable, and if defined, enable the DIU as a console during
1463 boot. See the documentation file doc/README.video for a
1464 description of this variable.
1466 - LCD Support: CONFIG_LCD
1468 Define this to enable LCD support (for output to LCD
1469 display); also select one of the supported displays
1470 by defining one of these:
1474 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1476 CONFIG_NEC_NL6448AC33:
1478 NEC NL6448AC33-18. Active, color, single scan.
1480 CONFIG_NEC_NL6448BC20
1482 NEC NL6448BC20-08. 6.5", 640x480.
1483 Active, color, single scan.
1485 CONFIG_NEC_NL6448BC33_54
1487 NEC NL6448BC33-54. 10.4", 640x480.
1488 Active, color, single scan.
1492 Sharp 320x240. Active, color, single scan.
1493 It isn't 16x9, and I am not sure what it is.
1495 CONFIG_SHARP_LQ64D341
1497 Sharp LQ64D341 display, 640x480.
1498 Active, color, single scan.
1502 HLD1045 display, 640x480.
1503 Active, color, single scan.
1507 Optrex CBL50840-2 NF-FW 99 22 M5
1509 Hitachi LMG6912RPFC-00T
1513 320x240. Black & white.
1515 CONFIG_LCD_ALIGNMENT
1517 Normally the LCD is page-aligned (typically 4KB). If this is
1518 defined then the LCD will be aligned to this value instead.
1519 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1520 here, since it is cheaper to change data cache settings on
1521 a per-section basis.
1526 Sometimes, for example if the display is mounted in portrait
1527 mode or even if it's mounted landscape but rotated by 180degree,
1528 we need to rotate our content of the display relative to the
1529 framebuffer, so that user can read the messages which are
1531 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1532 initialized with a given rotation from "vl_rot" out of
1533 "vidinfo_t" which is provided by the board specific code.
1534 The value for vl_rot is coded as following (matching to
1535 fbcon=rotate:<n> linux-kernel commandline):
1536 0 = no rotation respectively 0 degree
1537 1 = 90 degree rotation
1538 2 = 180 degree rotation
1539 3 = 270 degree rotation
1541 If CONFIG_LCD_ROTATION is not defined, the console will be
1542 initialized with 0degree rotation.
1546 Support drawing of RLE8-compressed bitmaps on the LCD.
1550 Enables an 'i2c edid' command which can read EDID
1551 information over I2C from an attached LCD display.
1553 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1555 If this option is set, the environment is checked for
1556 a variable "splashimage". If found, the usual display
1557 of logo, copyright and system information on the LCD
1558 is suppressed and the BMP image at the address
1559 specified in "splashimage" is loaded instead. The
1560 console is redirected to the "nulldev", too. This
1561 allows for a "silent" boot where a splash screen is
1562 loaded very quickly after power-on.
1564 CONFIG_SPLASHIMAGE_GUARD
1566 If this option is set, then U-Boot will prevent the environment
1567 variable "splashimage" from being set to a problematic address
1568 (see doc/README.displaying-bmps).
1569 This option is useful for targets where, due to alignment
1570 restrictions, an improperly aligned BMP image will cause a data
1571 abort. If you think you will not have problems with unaligned
1572 accesses (for example because your toolchain prevents them)
1573 there is no need to set this option.
1575 CONFIG_SPLASH_SCREEN_ALIGN
1577 If this option is set the splash image can be freely positioned
1578 on the screen. Environment variable "splashpos" specifies the
1579 position as "x,y". If a positive number is given it is used as
1580 number of pixel from left/top. If a negative number is given it
1581 is used as number of pixel from right/bottom. You can also
1582 specify 'm' for centering the image.
1585 setenv splashpos m,m
1586 => image at center of screen
1588 setenv splashpos 30,20
1589 => image at x = 30 and y = 20
1591 setenv splashpos -10,m
1592 => vertically centered image
1593 at x = dspWidth - bmpWidth - 9
1595 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1597 If this option is set, additionally to standard BMP
1598 images, gzipped BMP images can be displayed via the
1599 splashscreen support or the bmp command.
1601 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1603 If this option is set, 8-bit RLE compressed BMP images
1604 can be displayed via the splashscreen support or the
1607 - Compression support:
1610 Enabled by default to support gzip compressed images.
1614 If this option is set, support for bzip2 compressed
1615 images is included. If not, only uncompressed and gzip
1616 compressed images are supported.
1618 NOTE: the bzip2 algorithm requires a lot of RAM, so
1619 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1625 The address of PHY on MII bus.
1627 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1629 The clock frequency of the MII bus
1633 If this option is set, support for speed/duplex
1634 detection of gigabit PHY is included.
1636 CONFIG_PHY_RESET_DELAY
1638 Some PHY like Intel LXT971A need extra delay after
1639 reset before any MII register access is possible.
1640 For such PHY, set this option to the usec delay
1641 required. (minimum 300usec for LXT971A)
1643 CONFIG_PHY_CMD_DELAY (ppc4xx)
1645 Some PHY like Intel LXT971A need extra delay after
1646 command issued before MII status register can be read
1651 Define a default value for the IP address to use for
1652 the default Ethernet interface, in case this is not
1653 determined through e.g. bootp.
1654 (Environment variable "ipaddr")
1656 - Server IP address:
1659 Defines a default value for the IP address of a TFTP
1660 server to contact when using the "tftboot" command.
1661 (Environment variable "serverip")
1663 CONFIG_KEEP_SERVERADDR
1665 Keeps the server's MAC address, in the env 'serveraddr'
1666 for passing to bootargs (like Linux's netconsole option)
1668 - Gateway IP address:
1671 Defines a default value for the IP address of the
1672 default router where packets to other networks are
1674 (Environment variable "gatewayip")
1679 Defines a default value for the subnet mask (or
1680 routing prefix) which is used to determine if an IP
1681 address belongs to the local subnet or needs to be
1682 forwarded through a router.
1683 (Environment variable "netmask")
1685 - Multicast TFTP Mode:
1688 Defines whether you want to support multicast TFTP as per
1689 rfc-2090; for example to work with atftp. Lets lots of targets
1690 tftp down the same boot image concurrently. Note: the Ethernet
1691 driver in use must provide a function: mcast() to join/leave a
1694 - BOOTP Recovery Mode:
1695 CONFIG_BOOTP_RANDOM_DELAY
1697 If you have many targets in a network that try to
1698 boot using BOOTP, you may want to avoid that all
1699 systems send out BOOTP requests at precisely the same
1700 moment (which would happen for instance at recovery
1701 from a power failure, when all systems will try to
1702 boot, thus flooding the BOOTP server. Defining
1703 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1704 inserted before sending out BOOTP requests. The
1705 following delays are inserted then:
1707 1st BOOTP request: delay 0 ... 1 sec
1708 2nd BOOTP request: delay 0 ... 2 sec
1709 3rd BOOTP request: delay 0 ... 4 sec
1711 BOOTP requests: delay 0 ... 8 sec
1713 CONFIG_BOOTP_ID_CACHE_SIZE
1715 BOOTP packets are uniquely identified using a 32-bit ID. The
1716 server will copy the ID from client requests to responses and
1717 U-Boot will use this to determine if it is the destination of
1718 an incoming response. Some servers will check that addresses
1719 aren't in use before handing them out (usually using an ARP
1720 ping) and therefore take up to a few hundred milliseconds to
1721 respond. Network congestion may also influence the time it
1722 takes for a response to make it back to the client. If that
1723 time is too long, U-Boot will retransmit requests. In order
1724 to allow earlier responses to still be accepted after these
1725 retransmissions, U-Boot's BOOTP client keeps a small cache of
1726 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1727 cache. The default is to keep IDs for up to four outstanding
1728 requests. Increasing this will allow U-Boot to accept offers
1729 from a BOOTP client in networks with unusually high latency.
1731 - DHCP Advanced Options:
1732 You can fine tune the DHCP functionality by defining
1733 CONFIG_BOOTP_* symbols:
1735 CONFIG_BOOTP_SUBNETMASK
1736 CONFIG_BOOTP_GATEWAY
1737 CONFIG_BOOTP_HOSTNAME
1738 CONFIG_BOOTP_NISDOMAIN
1739 CONFIG_BOOTP_BOOTPATH
1740 CONFIG_BOOTP_BOOTFILESIZE
1743 CONFIG_BOOTP_SEND_HOSTNAME
1744 CONFIG_BOOTP_NTPSERVER
1745 CONFIG_BOOTP_TIMEOFFSET
1746 CONFIG_BOOTP_VENDOREX
1747 CONFIG_BOOTP_MAY_FAIL
1749 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1750 environment variable, not the BOOTP server.
1752 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1753 after the configured retry count, the call will fail
1754 instead of starting over. This can be used to fail over
1755 to Link-local IP address configuration if the DHCP server
1758 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1759 serverip from a DHCP server, it is possible that more
1760 than one DNS serverip is offered to the client.
1761 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1762 serverip will be stored in the additional environment
1763 variable "dnsip2". The first DNS serverip is always
1764 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1767 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1768 to do a dynamic update of a DNS server. To do this, they
1769 need the hostname of the DHCP requester.
1770 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1771 of the "hostname" environment variable is passed as
1772 option 12 to the DHCP server.
1774 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1776 A 32bit value in microseconds for a delay between
1777 receiving a "DHCP Offer" and sending the "DHCP Request".
1778 This fixes a problem with certain DHCP servers that don't
1779 respond 100% of the time to a "DHCP request". E.g. On an
1780 AT91RM9200 processor running at 180MHz, this delay needed
1781 to be *at least* 15,000 usec before a Windows Server 2003
1782 DHCP server would reply 100% of the time. I recommend at
1783 least 50,000 usec to be safe. The alternative is to hope
1784 that one of the retries will be successful but note that
1785 the DHCP timeout and retry process takes a longer than
1788 - Link-local IP address negotiation:
1789 Negotiate with other link-local clients on the local network
1790 for an address that doesn't require explicit configuration.
1791 This is especially useful if a DHCP server cannot be guaranteed
1792 to exist in all environments that the device must operate.
1794 See doc/README.link-local for more information.
1797 CONFIG_CDP_DEVICE_ID
1799 The device id used in CDP trigger frames.
1801 CONFIG_CDP_DEVICE_ID_PREFIX
1803 A two character string which is prefixed to the MAC address
1808 A printf format string which contains the ascii name of
1809 the port. Normally is set to "eth%d" which sets
1810 eth0 for the first Ethernet, eth1 for the second etc.
1812 CONFIG_CDP_CAPABILITIES
1814 A 32bit integer which indicates the device capabilities;
1815 0x00000010 for a normal host which does not forwards.
1819 An ascii string containing the version of the software.
1823 An ascii string containing the name of the platform.
1827 A 32bit integer sent on the trigger.
1829 CONFIG_CDP_POWER_CONSUMPTION
1831 A 16bit integer containing the power consumption of the
1832 device in .1 of milliwatts.
1834 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1836 A byte containing the id of the VLAN.
1838 - Status LED: CONFIG_LED_STATUS
1840 Several configurations allow to display the current
1841 status using a LED. For instance, the LED will blink
1842 fast while running U-Boot code, stop blinking as
1843 soon as a reply to a BOOTP request was received, and
1844 start blinking slow once the Linux kernel is running
1845 (supported by a status LED driver in the Linux
1846 kernel). Defining CONFIG_LED_STATUS enables this
1851 CONFIG_LED_STATUS_GPIO
1852 The status LED can be connected to a GPIO pin.
1853 In such cases, the gpio_led driver can be used as a
1854 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1855 to include the gpio_led driver in the U-Boot binary.
1857 CONFIG_GPIO_LED_INVERTED_TABLE
1858 Some GPIO connected LEDs may have inverted polarity in which
1859 case the GPIO high value corresponds to LED off state and
1860 GPIO low value corresponds to LED on state.
1861 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1862 with a list of GPIO LEDs that have inverted polarity.
1864 - I2C Support: CONFIG_SYS_I2C
1866 This enable the NEW i2c subsystem, and will allow you to use
1867 i2c commands at the u-boot command line (as long as you set
1868 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1869 based realtime clock chips or other i2c devices. See
1870 common/cmd_i2c.c for a description of the command line
1873 ported i2c driver to the new framework:
1874 - drivers/i2c/soft_i2c.c:
1875 - activate first bus with CONFIG_SYS_I2C_SOFT define
1876 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1877 for defining speed and slave address
1878 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1879 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1880 for defining speed and slave address
1881 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1882 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1883 for defining speed and slave address
1884 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1885 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1886 for defining speed and slave address
1888 - drivers/i2c/fsl_i2c.c:
1889 - activate i2c driver with CONFIG_SYS_I2C_FSL
1890 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1891 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1892 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1894 - If your board supports a second fsl i2c bus, define
1895 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1896 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1897 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1900 - drivers/i2c/tegra_i2c.c:
1901 - activate this driver with CONFIG_SYS_I2C_TEGRA
1902 - This driver adds 4 i2c buses with a fix speed from
1903 100000 and the slave addr 0!
1905 - drivers/i2c/ppc4xx_i2c.c
1906 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1907 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1908 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1910 - drivers/i2c/i2c_mxc.c
1911 - activate this driver with CONFIG_SYS_I2C_MXC
1912 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1913 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1914 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1915 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1916 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1917 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1918 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1919 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1920 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1921 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1922 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1923 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1924 If those defines are not set, default value is 100000
1925 for speed, and 0 for slave.
1927 - drivers/i2c/rcar_i2c.c:
1928 - activate this driver with CONFIG_SYS_I2C_RCAR
1929 - This driver adds 4 i2c buses
1931 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1932 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1933 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1934 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1935 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1936 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1937 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1938 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1939 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1941 - drivers/i2c/sh_i2c.c:
1942 - activate this driver with CONFIG_SYS_I2C_SH
1943 - This driver adds from 2 to 5 i2c buses
1945 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1946 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1947 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1948 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1949 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1950 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1951 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1952 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1953 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1954 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1955 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1957 - drivers/i2c/omap24xx_i2c.c
1958 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1959 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1960 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1961 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1962 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1963 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1964 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1965 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1966 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1967 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1968 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1970 - drivers/i2c/zynq_i2c.c
1971 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1972 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1973 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1975 - drivers/i2c/s3c24x0_i2c.c:
1976 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1977 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1978 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1979 with a fix speed from 100000 and the slave addr 0!
1981 - drivers/i2c/ihs_i2c.c
1982 - activate this driver with CONFIG_SYS_I2C_IHS
1983 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1984 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1985 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1986 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1987 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1988 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1989 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1990 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1991 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1992 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1993 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1994 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
1995 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1996 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1997 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1998 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1999 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2000 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2001 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2002 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2003 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2007 CONFIG_SYS_NUM_I2C_BUSES
2008 Hold the number of i2c buses you want to use.
2010 CONFIG_SYS_I2C_DIRECT_BUS
2011 define this, if you don't use i2c muxes on your hardware.
2012 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2015 CONFIG_SYS_I2C_MAX_HOPS
2016 define how many muxes are maximal consecutively connected
2017 on one i2c bus. If you not use i2c muxes, omit this
2020 CONFIG_SYS_I2C_BUSES
2021 hold a list of buses you want to use, only used if
2022 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2023 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2024 CONFIG_SYS_NUM_I2C_BUSES = 9:
2026 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2027 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2028 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2029 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2030 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2031 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2032 {1, {I2C_NULL_HOP}}, \
2033 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2034 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2038 bus 0 on adapter 0 without a mux
2039 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2040 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2041 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2042 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2043 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2044 bus 6 on adapter 1 without a mux
2045 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2046 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2048 If you do not have i2c muxes on your board, omit this define.
2050 - Legacy I2C Support:
2051 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2052 then the following macros need to be defined (examples are
2053 from include/configs/lwmon.h):
2057 (Optional). Any commands necessary to enable the I2C
2058 controller or configure ports.
2060 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2064 The code necessary to make the I2C data line active
2065 (driven). If the data line is open collector, this
2068 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2072 The code necessary to make the I2C data line tri-stated
2073 (inactive). If the data line is open collector, this
2076 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2080 Code that returns true if the I2C data line is high,
2083 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2087 If <bit> is true, sets the I2C data line high. If it
2088 is false, it clears it (low).
2090 eg: #define I2C_SDA(bit) \
2091 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2092 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2096 If <bit> is true, sets the I2C clock line high. If it
2097 is false, it clears it (low).
2099 eg: #define I2C_SCL(bit) \
2100 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2101 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2105 This delay is invoked four times per clock cycle so this
2106 controls the rate of data transfer. The data rate thus
2107 is 1 / (I2C_DELAY * 4). Often defined to be something
2110 #define I2C_DELAY udelay(2)
2112 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2114 If your arch supports the generic GPIO framework (asm/gpio.h),
2115 then you may alternatively define the two GPIOs that are to be
2116 used as SCL / SDA. Any of the previous I2C_xxx macros will
2117 have GPIO-based defaults assigned to them as appropriate.
2119 You should define these to the GPIO value as given directly to
2120 the generic GPIO functions.
2122 CONFIG_SYS_I2C_INIT_BOARD
2124 When a board is reset during an i2c bus transfer
2125 chips might think that the current transfer is still
2126 in progress. On some boards it is possible to access
2127 the i2c SCLK line directly, either by using the
2128 processor pin as a GPIO or by having a second pin
2129 connected to the bus. If this option is defined a
2130 custom i2c_init_board() routine in boards/xxx/board.c
2131 is run early in the boot sequence.
2133 CONFIG_I2C_MULTI_BUS
2135 This option allows the use of multiple I2C buses, each of which
2136 must have a controller. At any point in time, only one bus is
2137 active. To switch to a different bus, use the 'i2c dev' command.
2138 Note that bus numbering is zero-based.
2140 CONFIG_SYS_I2C_NOPROBES
2142 This option specifies a list of I2C devices that will be skipped
2143 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2144 is set, specify a list of bus-device pairs. Otherwise, specify
2145 a 1D array of device addresses
2148 #undef CONFIG_I2C_MULTI_BUS
2149 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2151 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2153 #define CONFIG_I2C_MULTI_BUS
2154 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2156 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2158 CONFIG_SYS_SPD_BUS_NUM
2160 If defined, then this indicates the I2C bus number for DDR SPD.
2161 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2163 CONFIG_SYS_RTC_BUS_NUM
2165 If defined, then this indicates the I2C bus number for the RTC.
2166 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2168 CONFIG_SOFT_I2C_READ_REPEATED_START
2170 defining this will force the i2c_read() function in
2171 the soft_i2c driver to perform an I2C repeated start
2172 between writing the address pointer and reading the
2173 data. If this define is omitted the default behaviour
2174 of doing a stop-start sequence will be used. Most I2C
2175 devices can use either method, but some require one or
2178 - SPI Support: CONFIG_SPI
2180 Enables SPI driver (so far only tested with
2181 SPI EEPROM, also an instance works with Crystal A/D and
2182 D/As on the SACSng board)
2186 Enables the driver for SPI controller on SuperH. Currently
2187 only SH7757 is supported.
2191 Enables a software (bit-bang) SPI driver rather than
2192 using hardware support. This is a general purpose
2193 driver that only requires three general I/O port pins
2194 (two outputs, one input) to function. If this is
2195 defined, the board configuration must define several
2196 SPI configuration items (port pins to use, etc). For
2197 an example, see include/configs/sacsng.h.
2201 Enables a hardware SPI driver for general-purpose reads
2202 and writes. As with CONFIG_SOFT_SPI, the board configuration
2203 must define a list of chip-select function pointers.
2204 Currently supported on some MPC8xxx processors. For an
2205 example, see include/configs/mpc8349emds.h.
2209 Enables the driver for the SPI controllers on i.MX and MXC
2210 SoCs. Currently i.MX31/35/51 are supported.
2212 CONFIG_SYS_SPI_MXC_WAIT
2213 Timeout for waiting until spi transfer completed.
2214 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2216 - FPGA Support: CONFIG_FPGA
2218 Enables FPGA subsystem.
2220 CONFIG_FPGA_<vendor>
2222 Enables support for specific chip vendors.
2225 CONFIG_FPGA_<family>
2227 Enables support for FPGA family.
2228 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2232 Specify the number of FPGA devices to support.
2234 CONFIG_SYS_FPGA_PROG_FEEDBACK
2236 Enable printing of hash marks during FPGA configuration.
2238 CONFIG_SYS_FPGA_CHECK_BUSY
2240 Enable checks on FPGA configuration interface busy
2241 status by the configuration function. This option
2242 will require a board or device specific function to
2247 If defined, a function that provides delays in the FPGA
2248 configuration driver.
2250 CONFIG_SYS_FPGA_CHECK_CTRLC
2251 Allow Control-C to interrupt FPGA configuration
2253 CONFIG_SYS_FPGA_CHECK_ERROR
2255 Check for configuration errors during FPGA bitfile
2256 loading. For example, abort during Virtex II
2257 configuration if the INIT_B line goes low (which
2258 indicated a CRC error).
2260 CONFIG_SYS_FPGA_WAIT_INIT
2262 Maximum time to wait for the INIT_B line to de-assert
2263 after PROB_B has been de-asserted during a Virtex II
2264 FPGA configuration sequence. The default time is 500
2267 CONFIG_SYS_FPGA_WAIT_BUSY
2269 Maximum time to wait for BUSY to de-assert during
2270 Virtex II FPGA configuration. The default is 5 ms.
2272 CONFIG_SYS_FPGA_WAIT_CONFIG
2274 Time to wait after FPGA configuration. The default is
2277 - Configuration Management:
2280 Some SoCs need special image types (e.g. U-Boot binary
2281 with a special header) as build targets. By defining
2282 CONFIG_BUILD_TARGET in the SoC / board header, this
2283 special image will be automatically built upon calling
2288 If defined, this string will be added to the U-Boot
2289 version information (U_BOOT_VERSION)
2291 - Vendor Parameter Protection:
2293 U-Boot considers the values of the environment
2294 variables "serial#" (Board Serial Number) and
2295 "ethaddr" (Ethernet Address) to be parameters that
2296 are set once by the board vendor / manufacturer, and
2297 protects these variables from casual modification by
2298 the user. Once set, these variables are read-only,
2299 and write or delete attempts are rejected. You can
2300 change this behaviour:
2302 If CONFIG_ENV_OVERWRITE is #defined in your config
2303 file, the write protection for vendor parameters is
2304 completely disabled. Anybody can change or delete
2307 Alternatively, if you define _both_ an ethaddr in the
2308 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2309 Ethernet address is installed in the environment,
2310 which can be changed exactly ONCE by the user. [The
2311 serial# is unaffected by this, i. e. it remains
2314 The same can be accomplished in a more flexible way
2315 for any variable by configuring the type of access
2316 to allow for those variables in the ".flags" variable
2317 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2322 Define this variable to enable the reservation of
2323 "protected RAM", i. e. RAM which is not overwritten
2324 by U-Boot. Define CONFIG_PRAM to hold the number of
2325 kB you want to reserve for pRAM. You can overwrite
2326 this default value by defining an environment
2327 variable "pram" to the number of kB you want to
2328 reserve. Note that the board info structure will
2329 still show the full amount of RAM. If pRAM is
2330 reserved, a new environment variable "mem" will
2331 automatically be defined to hold the amount of
2332 remaining RAM in a form that can be passed as boot
2333 argument to Linux, for instance like that:
2335 setenv bootargs ... mem=\${mem}
2338 This way you can tell Linux not to use this memory,
2339 either, which results in a memory region that will
2340 not be affected by reboots.
2342 *WARNING* If your board configuration uses automatic
2343 detection of the RAM size, you must make sure that
2344 this memory test is non-destructive. So far, the
2345 following board configurations are known to be
2348 IVMS8, IVML24, SPD8xx,
2349 HERMES, IP860, RPXlite, LWMON,
2352 - Access to physical memory region (> 4GB)
2353 Some basic support is provided for operations on memory not
2354 normally accessible to U-Boot - e.g. some architectures
2355 support access to more than 4GB of memory on 32-bit
2356 machines using physical address extension or similar.
2357 Define CONFIG_PHYSMEM to access this basic support, which
2358 currently only supports clearing the memory.
2363 Define this variable to stop the system in case of a
2364 fatal error, so that you have to reset it manually.
2365 This is probably NOT a good idea for an embedded
2366 system where you want the system to reboot
2367 automatically as fast as possible, but it may be
2368 useful during development since you can try to debug
2369 the conditions that lead to the situation.
2371 CONFIG_NET_RETRY_COUNT
2373 This variable defines the number of retries for
2374 network operations like ARP, RARP, TFTP, or BOOTP
2375 before giving up the operation. If not defined, a
2376 default value of 5 is used.
2380 Timeout waiting for an ARP reply in milliseconds.
2384 Timeout in milliseconds used in NFS protocol.
2385 If you encounter "ERROR: Cannot umount" in nfs command,
2386 try longer timeout such as
2387 #define CONFIG_NFS_TIMEOUT 10000UL
2389 - Command Interpreter:
2390 CONFIG_AUTO_COMPLETE
2392 Enable auto completion of commands using TAB.
2394 CONFIG_SYS_PROMPT_HUSH_PS2
2396 This defines the secondary prompt string, which is
2397 printed when the command interpreter needs more input
2398 to complete a command. Usually "> ".
2402 In the current implementation, the local variables
2403 space and global environment variables space are
2404 separated. Local variables are those you define by
2405 simply typing `name=value'. To access a local
2406 variable later on, you have write `$name' or
2407 `${name}'; to execute the contents of a variable
2408 directly type `$name' at the command prompt.
2410 Global environment variables are those you use
2411 setenv/printenv to work with. To run a command stored
2412 in such a variable, you need to use the run command,
2413 and you must not use the '$' sign to access them.
2415 To store commands and special characters in a
2416 variable, please use double quotation marks
2417 surrounding the whole text of the variable, instead
2418 of the backslashes before semicolons and special
2421 - Command Line Editing and History:
2422 CONFIG_CMDLINE_EDITING
2424 Enable editing and History functions for interactive
2425 command line input operations
2427 - Command Line PS1/PS2 support:
2428 CONFIG_CMDLINE_PS_SUPPORT
2430 Enable support for changing the command prompt string
2431 at run-time. Only static string is supported so far.
2432 The string is obtained from environment variables PS1
2435 - Default Environment:
2436 CONFIG_EXTRA_ENV_SETTINGS
2438 Define this to contain any number of null terminated
2439 strings (variable = value pairs) that will be part of
2440 the default environment compiled into the boot image.
2442 For example, place something like this in your
2443 board's config file:
2445 #define CONFIG_EXTRA_ENV_SETTINGS \
2449 Warning: This method is based on knowledge about the
2450 internal format how the environment is stored by the
2451 U-Boot code. This is NOT an official, exported
2452 interface! Although it is unlikely that this format
2453 will change soon, there is no guarantee either.
2454 You better know what you are doing here.
2456 Note: overly (ab)use of the default environment is
2457 discouraged. Make sure to check other ways to preset
2458 the environment like the "source" command or the
2461 CONFIG_ENV_VARS_UBOOT_CONFIG
2463 Define this in order to add variables describing the
2464 U-Boot build configuration to the default environment.
2465 These will be named arch, cpu, board, vendor, and soc.
2467 Enabling this option will cause the following to be defined:
2475 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2477 Define this in order to add variables describing certain
2478 run-time determined information about the hardware to the
2479 environment. These will be named board_name, board_rev.
2481 CONFIG_DELAY_ENVIRONMENT
2483 Normally the environment is loaded when the board is
2484 initialised so that it is available to U-Boot. This inhibits
2485 that so that the environment is not available until
2486 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2487 this is instead controlled by the value of
2488 /config/load-environment.
2490 - DataFlash Support:
2491 CONFIG_HAS_DATAFLASH
2493 Defining this option enables DataFlash features and
2494 allows to read/write in Dataflash via the standard
2497 - Serial Flash support
2500 Defining this option enables SPI flash commands
2501 'sf probe/read/write/erase/update'.
2503 Usage requires an initial 'probe' to define the serial
2504 flash parameters, followed by read/write/erase/update
2507 The following defaults may be provided by the platform
2508 to handle the common case when only a single serial
2509 flash is present on the system.
2511 CONFIG_SF_DEFAULT_BUS Bus identifier
2512 CONFIG_SF_DEFAULT_CS Chip-select
2513 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2514 CONFIG_SF_DEFAULT_SPEED in Hz
2518 Define this option to include a destructive SPI flash
2521 - SystemACE Support:
2524 Adding this option adds support for Xilinx SystemACE
2525 chips attached via some sort of local bus. The address
2526 of the chip must also be defined in the
2527 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2529 #define CONFIG_SYSTEMACE
2530 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2532 When SystemACE support is added, the "ace" device type
2533 becomes available to the fat commands, i.e. fatls.
2535 - TFTP Fixed UDP Port:
2538 If this is defined, the environment variable tftpsrcp
2539 is used to supply the TFTP UDP source port value.
2540 If tftpsrcp isn't defined, the normal pseudo-random port
2541 number generator is used.
2543 Also, the environment variable tftpdstp is used to supply
2544 the TFTP UDP destination port value. If tftpdstp isn't
2545 defined, the normal port 69 is used.
2547 The purpose for tftpsrcp is to allow a TFTP server to
2548 blindly start the TFTP transfer using the pre-configured
2549 target IP address and UDP port. This has the effect of
2550 "punching through" the (Windows XP) firewall, allowing
2551 the remainder of the TFTP transfer to proceed normally.
2552 A better solution is to properly configure the firewall,
2553 but sometimes that is not allowed.
2555 - bootcount support:
2556 CONFIG_BOOTCOUNT_LIMIT
2558 This enables the bootcounter support, see:
2559 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2562 enable special bootcounter support on at91sam9xe based boards.
2564 enable special bootcounter support on da850 based boards.
2565 CONFIG_BOOTCOUNT_RAM
2566 enable support for the bootcounter in RAM
2567 CONFIG_BOOTCOUNT_I2C
2568 enable support for the bootcounter on an i2c (like RTC) device.
2569 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2570 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2572 CONFIG_BOOTCOUNT_ALEN = address len
2574 - Show boot progress:
2575 CONFIG_SHOW_BOOT_PROGRESS
2577 Defining this option allows to add some board-
2578 specific code (calling a user-provided function
2579 "show_boot_progress(int)") that enables you to show
2580 the system's boot progress on some display (for
2581 example, some LED's) on your board. At the moment,
2582 the following checkpoints are implemented:
2585 Legacy uImage format:
2588 1 common/cmd_bootm.c before attempting to boot an image
2589 -1 common/cmd_bootm.c Image header has bad magic number
2590 2 common/cmd_bootm.c Image header has correct magic number
2591 -2 common/cmd_bootm.c Image header has bad checksum
2592 3 common/cmd_bootm.c Image header has correct checksum
2593 -3 common/cmd_bootm.c Image data has bad checksum
2594 4 common/cmd_bootm.c Image data has correct checksum
2595 -4 common/cmd_bootm.c Image is for unsupported architecture
2596 5 common/cmd_bootm.c Architecture check OK
2597 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2598 6 common/cmd_bootm.c Image Type check OK
2599 -6 common/cmd_bootm.c gunzip uncompression error
2600 -7 common/cmd_bootm.c Unimplemented compression type
2601 7 common/cmd_bootm.c Uncompression OK
2602 8 common/cmd_bootm.c No uncompress/copy overwrite error
2603 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2605 9 common/image.c Start initial ramdisk verification
2606 -10 common/image.c Ramdisk header has bad magic number
2607 -11 common/image.c Ramdisk header has bad checksum
2608 10 common/image.c Ramdisk header is OK
2609 -12 common/image.c Ramdisk data has bad checksum
2610 11 common/image.c Ramdisk data has correct checksum
2611 12 common/image.c Ramdisk verification complete, start loading
2612 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2613 13 common/image.c Start multifile image verification
2614 14 common/image.c No initial ramdisk, no multifile, continue.
2616 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2618 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2619 -31 post/post.c POST test failed, detected by post_output_backlog()
2620 -32 post/post.c POST test failed, detected by post_run_single()
2622 34 common/cmd_doc.c before loading a Image from a DOC device
2623 -35 common/cmd_doc.c Bad usage of "doc" command
2624 35 common/cmd_doc.c correct usage of "doc" command
2625 -36 common/cmd_doc.c No boot device
2626 36 common/cmd_doc.c correct boot device
2627 -37 common/cmd_doc.c Unknown Chip ID on boot device
2628 37 common/cmd_doc.c correct chip ID found, device available
2629 -38 common/cmd_doc.c Read Error on boot device
2630 38 common/cmd_doc.c reading Image header from DOC device OK
2631 -39 common/cmd_doc.c Image header has bad magic number
2632 39 common/cmd_doc.c Image header has correct magic number
2633 -40 common/cmd_doc.c Error reading Image from DOC device
2634 40 common/cmd_doc.c Image header has correct magic number
2635 41 common/cmd_ide.c before loading a Image from a IDE device
2636 -42 common/cmd_ide.c Bad usage of "ide" command
2637 42 common/cmd_ide.c correct usage of "ide" command
2638 -43 common/cmd_ide.c No boot device
2639 43 common/cmd_ide.c boot device found
2640 -44 common/cmd_ide.c Device not available
2641 44 common/cmd_ide.c Device available
2642 -45 common/cmd_ide.c wrong partition selected
2643 45 common/cmd_ide.c partition selected
2644 -46 common/cmd_ide.c Unknown partition table
2645 46 common/cmd_ide.c valid partition table found
2646 -47 common/cmd_ide.c Invalid partition type
2647 47 common/cmd_ide.c correct partition type
2648 -48 common/cmd_ide.c Error reading Image Header on boot device
2649 48 common/cmd_ide.c reading Image Header from IDE device OK
2650 -49 common/cmd_ide.c Image header has bad magic number
2651 49 common/cmd_ide.c Image header has correct magic number
2652 -50 common/cmd_ide.c Image header has bad checksum
2653 50 common/cmd_ide.c Image header has correct checksum
2654 -51 common/cmd_ide.c Error reading Image from IDE device
2655 51 common/cmd_ide.c reading Image from IDE device OK
2656 52 common/cmd_nand.c before loading a Image from a NAND device
2657 -53 common/cmd_nand.c Bad usage of "nand" command
2658 53 common/cmd_nand.c correct usage of "nand" command
2659 -54 common/cmd_nand.c No boot device
2660 54 common/cmd_nand.c boot device found
2661 -55 common/cmd_nand.c Unknown Chip ID on boot device
2662 55 common/cmd_nand.c correct chip ID found, device available
2663 -56 common/cmd_nand.c Error reading Image Header on boot device
2664 56 common/cmd_nand.c reading Image Header from NAND device OK
2665 -57 common/cmd_nand.c Image header has bad magic number
2666 57 common/cmd_nand.c Image header has correct magic number
2667 -58 common/cmd_nand.c Error reading Image from NAND device
2668 58 common/cmd_nand.c reading Image from NAND device OK
2670 -60 common/env_common.c Environment has a bad CRC, using default
2672 64 net/eth.c starting with Ethernet configuration.
2673 -64 net/eth.c no Ethernet found.
2674 65 net/eth.c Ethernet found.
2676 -80 common/cmd_net.c usage wrong
2677 80 common/cmd_net.c before calling net_loop()
2678 -81 common/cmd_net.c some error in net_loop() occurred
2679 81 common/cmd_net.c net_loop() back without error
2680 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2681 82 common/cmd_net.c trying automatic boot
2682 83 common/cmd_net.c running "source" command
2683 -83 common/cmd_net.c some error in automatic boot or "source" command
2684 84 common/cmd_net.c end without errors
2689 100 common/cmd_bootm.c Kernel FIT Image has correct format
2690 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2691 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2692 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2693 102 common/cmd_bootm.c Kernel unit name specified
2694 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2695 103 common/cmd_bootm.c Found configuration node
2696 104 common/cmd_bootm.c Got kernel subimage node offset
2697 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2698 105 common/cmd_bootm.c Kernel subimage hash verification OK
2699 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2700 106 common/cmd_bootm.c Architecture check OK
2701 -106 common/cmd_bootm.c Kernel subimage has wrong type
2702 107 common/cmd_bootm.c Kernel subimage type OK
2703 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2704 108 common/cmd_bootm.c Got kernel subimage data/size
2705 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2706 -109 common/cmd_bootm.c Can't get kernel subimage type
2707 -110 common/cmd_bootm.c Can't get kernel subimage comp
2708 -111 common/cmd_bootm.c Can't get kernel subimage os
2709 -112 common/cmd_bootm.c Can't get kernel subimage load address
2710 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2712 120 common/image.c Start initial ramdisk verification
2713 -120 common/image.c Ramdisk FIT image has incorrect format
2714 121 common/image.c Ramdisk FIT image has correct format
2715 122 common/image.c No ramdisk subimage unit name, using configuration
2716 -122 common/image.c Can't get configuration for ramdisk subimage
2717 123 common/image.c Ramdisk unit name specified
2718 -124 common/image.c Can't get ramdisk subimage node offset
2719 125 common/image.c Got ramdisk subimage node offset
2720 -125 common/image.c Ramdisk subimage hash verification failed
2721 126 common/image.c Ramdisk subimage hash verification OK
2722 -126 common/image.c Ramdisk subimage for unsupported architecture
2723 127 common/image.c Architecture check OK
2724 -127 common/image.c Can't get ramdisk subimage data/size
2725 128 common/image.c Got ramdisk subimage data/size
2726 129 common/image.c Can't get ramdisk load address
2727 -129 common/image.c Got ramdisk load address
2729 -130 common/cmd_doc.c Incorrect FIT image format
2730 131 common/cmd_doc.c FIT image format OK
2732 -140 common/cmd_ide.c Incorrect FIT image format
2733 141 common/cmd_ide.c FIT image format OK
2735 -150 common/cmd_nand.c Incorrect FIT image format
2736 151 common/cmd_nand.c FIT image format OK
2738 - legacy image format:
2739 CONFIG_IMAGE_FORMAT_LEGACY
2740 enables the legacy image format support in U-Boot.
2743 enabled if CONFIG_FIT_SIGNATURE is not defined.
2745 CONFIG_DISABLE_IMAGE_LEGACY
2746 disable the legacy image format
2748 This define is introduced, as the legacy image format is
2749 enabled per default for backward compatibility.
2751 - Standalone program support:
2752 CONFIG_STANDALONE_LOAD_ADDR
2754 This option defines a board specific value for the
2755 address where standalone program gets loaded, thus
2756 overwriting the architecture dependent default
2759 - Frame Buffer Address:
2762 Define CONFIG_FB_ADDR if you want to use specific
2763 address for frame buffer. This is typically the case
2764 when using a graphics controller has separate video
2765 memory. U-Boot will then place the frame buffer at
2766 the given address instead of dynamically reserving it
2767 in system RAM by calling lcd_setmem(), which grabs
2768 the memory for the frame buffer depending on the
2769 configured panel size.
2771 Please see board_init_f function.
2773 - Automatic software updates via TFTP server
2775 CONFIG_UPDATE_TFTP_CNT_MAX
2776 CONFIG_UPDATE_TFTP_MSEC_MAX
2778 These options enable and control the auto-update feature;
2779 for a more detailed description refer to doc/README.update.
2781 - MTD Support (mtdparts command, UBI support)
2784 Adds the MTD device infrastructure from the Linux kernel.
2785 Needed for mtdparts command support.
2787 CONFIG_MTD_PARTITIONS
2789 Adds the MTD partitioning infrastructure from the Linux
2790 kernel. Needed for UBI support.
2793 CONFIG_UBI_SILENCE_MSG
2795 Make the verbose messages from UBI stop printing. This leaves
2796 warnings and errors enabled.
2799 CONFIG_MTD_UBI_WL_THRESHOLD
2800 This parameter defines the maximum difference between the highest
2801 erase counter value and the lowest erase counter value of eraseblocks
2802 of UBI devices. When this threshold is exceeded, UBI starts performing
2803 wear leveling by means of moving data from eraseblock with low erase
2804 counter to eraseblocks with high erase counter.
2806 The default value should be OK for SLC NAND flashes, NOR flashes and
2807 other flashes which have eraseblock life-cycle 100000 or more.
2808 However, in case of MLC NAND flashes which typically have eraseblock
2809 life-cycle less than 10000, the threshold should be lessened (e.g.,
2810 to 128 or 256, although it does not have to be power of 2).
2814 CONFIG_MTD_UBI_BEB_LIMIT
2815 This option specifies the maximum bad physical eraseblocks UBI
2816 expects on the MTD device (per 1024 eraseblocks). If the
2817 underlying flash does not admit of bad eraseblocks (e.g. NOR
2818 flash), this value is ignored.
2820 NAND datasheets often specify the minimum and maximum NVM
2821 (Number of Valid Blocks) for the flashes' endurance lifetime.
2822 The maximum expected bad eraseblocks per 1024 eraseblocks
2823 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2824 which gives 20 for most NANDs (MaxNVB is basically the total
2825 count of eraseblocks on the chip).
2827 To put it differently, if this value is 20, UBI will try to
2828 reserve about 1.9% of physical eraseblocks for bad blocks
2829 handling. And that will be 1.9% of eraseblocks on the entire
2830 NAND chip, not just the MTD partition UBI attaches. This means
2831 that if you have, say, a NAND flash chip admits maximum 40 bad
2832 eraseblocks, and it is split on two MTD partitions of the same
2833 size, UBI will reserve 40 eraseblocks when attaching a
2838 CONFIG_MTD_UBI_FASTMAP
2839 Fastmap is a mechanism which allows attaching an UBI device
2840 in nearly constant time. Instead of scanning the whole MTD device it
2841 only has to locate a checkpoint (called fastmap) on the device.
2842 The on-flash fastmap contains all information needed to attach
2843 the device. Using fastmap makes only sense on large devices where
2844 attaching by scanning takes long. UBI will not automatically install
2845 a fastmap on old images, but you can set the UBI parameter
2846 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2847 that fastmap-enabled images are still usable with UBI implementations
2848 without fastmap support. On typical flash devices the whole fastmap
2849 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2851 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2852 Set this parameter to enable fastmap automatically on images
2856 CONFIG_MTD_UBI_FM_DEBUG
2857 Enable UBI fastmap debug
2861 CONFIG_UBIFS_SILENCE_MSG
2863 Make the verbose messages from UBIFS stop printing. This leaves
2864 warnings and errors enabled.
2868 Enable building of SPL globally.
2871 LDSCRIPT for linking the SPL binary.
2873 CONFIG_SPL_MAX_FOOTPRINT
2874 Maximum size in memory allocated to the SPL, BSS included.
2875 When defined, the linker checks that the actual memory
2876 used by SPL from _start to __bss_end does not exceed it.
2877 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2878 must not be both defined at the same time.
2881 Maximum size of the SPL image (text, data, rodata, and
2882 linker lists sections), BSS excluded.
2883 When defined, the linker checks that the actual size does
2886 CONFIG_SPL_TEXT_BASE
2887 TEXT_BASE for linking the SPL binary.
2889 CONFIG_SPL_RELOC_TEXT_BASE
2890 Address to relocate to. If unspecified, this is equal to
2891 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2893 CONFIG_SPL_BSS_START_ADDR
2894 Link address for the BSS within the SPL binary.
2896 CONFIG_SPL_BSS_MAX_SIZE
2897 Maximum size in memory allocated to the SPL BSS.
2898 When defined, the linker checks that the actual memory used
2899 by SPL from __bss_start to __bss_end does not exceed it.
2900 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2901 must not be both defined at the same time.
2904 Adress of the start of the stack SPL will use
2906 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2907 When defined, SPL will panic() if the image it has
2908 loaded does not have a signature.
2909 Defining this is useful when code which loads images
2910 in SPL cannot guarantee that absolutely all read errors
2912 An example is the LPC32XX MLC NAND driver, which will
2913 consider that a completely unreadable NAND block is bad,
2914 and thus should be skipped silently.
2916 CONFIG_SPL_RELOC_STACK
2917 Adress of the start of the stack SPL will use after
2918 relocation. If unspecified, this is equal to
2921 CONFIG_SYS_SPL_MALLOC_START
2922 Starting address of the malloc pool used in SPL.
2923 When this option is set the full malloc is used in SPL and
2924 it is set up by spl_init() and before that, the simple malloc()
2925 can be used if CONFIG_SYS_MALLOC_F is defined.
2927 CONFIG_SYS_SPL_MALLOC_SIZE
2928 The size of the malloc pool used in SPL.
2930 CONFIG_SPL_FRAMEWORK
2931 Enable the SPL framework under common/. This framework
2932 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2933 NAND loading of the Linux Kernel.
2936 Enable booting directly to an OS from SPL.
2937 See also: doc/README.falcon
2939 CONFIG_SPL_DISPLAY_PRINT
2940 For ARM, enable an optional function to print more information
2941 about the running system.
2943 CONFIG_SPL_INIT_MINIMAL
2944 Arch init code should be built for a very small image
2946 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2947 Partition on the MMC to load U-Boot from when the MMC is being
2950 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2951 Sector to load kernel uImage from when MMC is being
2952 used in raw mode (for Falcon mode)
2954 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2955 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2956 Sector and number of sectors to load kernel argument
2957 parameters from when MMC is being used in raw mode
2960 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2961 Partition on the MMC to load U-Boot from when the MMC is being
2964 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2965 Filename to read to load U-Boot when reading from filesystem
2967 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2968 Filename to read to load kernel uImage when reading
2969 from filesystem (for Falcon mode)
2971 CONFIG_SPL_FS_LOAD_ARGS_NAME
2972 Filename to read to load kernel argument parameters
2973 when reading from filesystem (for Falcon mode)
2975 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2976 Set this for NAND SPL on PPC mpc83xx targets, so that
2977 start.S waits for the rest of the SPL to load before
2978 continuing (the hardware starts execution after just
2979 loading the first page rather than the full 4K).
2981 CONFIG_SPL_SKIP_RELOCATE
2982 Avoid SPL relocation
2984 CONFIG_SPL_NAND_BASE
2985 Include nand_base.c in the SPL. Requires
2986 CONFIG_SPL_NAND_DRIVERS.
2988 CONFIG_SPL_NAND_DRIVERS
2989 SPL uses normal NAND drivers, not minimal drivers.
2992 Include standard software ECC in the SPL
2994 CONFIG_SPL_NAND_SIMPLE
2995 Support for NAND boot using simple NAND drivers that
2996 expose the cmd_ctrl() interface.
2999 Support for a lightweight UBI (fastmap) scanner and
3002 CONFIG_SPL_NAND_RAW_ONLY
3003 Support to boot only raw u-boot.bin images. Use this only
3004 if you need to save space.
3006 CONFIG_SPL_COMMON_INIT_DDR
3007 Set for common ddr init with serial presence detect in
3010 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3011 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3012 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3013 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3014 CONFIG_SYS_NAND_ECCBYTES
3015 Defines the size and behavior of the NAND that SPL uses
3018 CONFIG_SPL_NAND_BOOT
3019 Add support NAND boot
3021 CONFIG_SYS_NAND_U_BOOT_OFFS
3022 Location in NAND to read U-Boot from
3024 CONFIG_SYS_NAND_U_BOOT_DST
3025 Location in memory to load U-Boot to
3027 CONFIG_SYS_NAND_U_BOOT_SIZE
3028 Size of image to load
3030 CONFIG_SYS_NAND_U_BOOT_START
3031 Entry point in loaded image to jump to
3033 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3034 Define this if you need to first read the OOB and then the
3035 data. This is used, for example, on davinci platforms.
3037 CONFIG_SPL_OMAP3_ID_NAND
3038 Support for an OMAP3-specific set of functions to return the
3039 ID and MFR of the first attached NAND chip, if present.
3041 CONFIG_SPL_RAM_DEVICE
3042 Support for running image already present in ram, in SPL binary
3045 Image offset to which the SPL should be padded before appending
3046 the SPL payload. By default, this is defined as
3047 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3048 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3049 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3052 Final target image containing SPL and payload. Some SPLs
3053 use an arch-specific makefile fragment instead, for
3054 example if more than one image needs to be produced.
3056 CONFIG_FIT_SPL_PRINT
3057 Printing information about a FIT image adds quite a bit of
3058 code to SPL. So this is normally disabled in SPL. Use this
3059 option to re-enable it. This will affect the output of the
3060 bootm command when booting a FIT image.
3064 Enable building of TPL globally.
3067 Image offset to which the TPL should be padded before appending
3068 the TPL payload. By default, this is defined as
3069 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3070 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3071 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3073 - Interrupt support (PPC):
3075 There are common interrupt_init() and timer_interrupt()
3076 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3077 for CPU specific initialization. interrupt_init_cpu()
3078 should set decrementer_count to appropriate value. If
3079 CPU resets decrementer automatically after interrupt
3080 (ppc4xx) it should set decrementer_count to zero.
3081 timer_interrupt() calls timer_interrupt_cpu() for CPU
3082 specific handling. If board has watchdog / status_led
3083 / other_activity_monitor it works automatically from
3084 general timer_interrupt().
3087 Board initialization settings:
3088 ------------------------------
3090 During Initialization u-boot calls a number of board specific functions
3091 to allow the preparation of board specific prerequisites, e.g. pin setup
3092 before drivers are initialized. To enable these callbacks the
3093 following configuration macros have to be defined. Currently this is
3094 architecture specific, so please check arch/your_architecture/lib/board.c
3095 typically in board_init_f() and board_init_r().
3097 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3098 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3099 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3100 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3102 Configuration Settings:
3103 -----------------------
3105 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3106 Optionally it can be defined to support 64-bit memory commands.
3108 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3109 undefine this when you're short of memory.
3111 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3112 width of the commands listed in the 'help' command output.
3114 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3115 prompt for user input.
3117 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3119 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3121 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3123 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3124 the application (usually a Linux kernel) when it is
3127 - CONFIG_SYS_BAUDRATE_TABLE:
3128 List of legal baudrate settings for this board.
3130 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3131 Begin and End addresses of the area used by the
3134 - CONFIG_SYS_ALT_MEMTEST:
3135 Enable an alternate, more extensive memory test.
3137 - CONFIG_SYS_MEMTEST_SCRATCH:
3138 Scratch address used by the alternate memory test
3139 You only need to set this if address zero isn't writeable
3141 - CONFIG_SYS_MEM_RESERVE_SECURE
3142 Only implemented for ARMv8 for now.
3143 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3144 is substracted from total RAM and won't be reported to OS.
3145 This memory can be used as secure memory. A variable
3146 gd->arch.secure_ram is used to track the location. In systems
3147 the RAM base is not zero, or RAM is divided into banks,
3148 this variable needs to be recalcuated to get the address.
3150 - CONFIG_SYS_MEM_TOP_HIDE:
3151 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3152 this specified memory area will get subtracted from the top
3153 (end) of RAM and won't get "touched" at all by U-Boot. By
3154 fixing up gd->ram_size the Linux kernel should gets passed
3155 the now "corrected" memory size and won't touch it either.
3156 This should work for arch/ppc and arch/powerpc. Only Linux
3157 board ports in arch/powerpc with bootwrapper support that
3158 recalculate the memory size from the SDRAM controller setup
3159 will have to get fixed in Linux additionally.
3161 This option can be used as a workaround for the 440EPx/GRx
3162 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3165 WARNING: Please make sure that this value is a multiple of
3166 the Linux page size (normally 4k). If this is not the case,
3167 then the end address of the Linux memory will be located at a
3168 non page size aligned address and this could cause major
3171 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3172 Enable temporary baudrate change while serial download
3174 - CONFIG_SYS_SDRAM_BASE:
3175 Physical start address of SDRAM. _Must_ be 0 here.
3177 - CONFIG_SYS_FLASH_BASE:
3178 Physical start address of Flash memory.
3180 - CONFIG_SYS_MONITOR_BASE:
3181 Physical start address of boot monitor code (set by
3182 make config files to be same as the text base address
3183 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3184 CONFIG_SYS_FLASH_BASE when booting from flash.
3186 - CONFIG_SYS_MONITOR_LEN:
3187 Size of memory reserved for monitor code, used to
3188 determine _at_compile_time_ (!) if the environment is
3189 embedded within the U-Boot image, or in a separate
3192 - CONFIG_SYS_MALLOC_LEN:
3193 Size of DRAM reserved for malloc() use.
3195 - CONFIG_SYS_MALLOC_F_LEN
3196 Size of the malloc() pool for use before relocation. If
3197 this is defined, then a very simple malloc() implementation
3198 will become available before relocation. The address is just
3199 below the global data, and the stack is moved down to make
3202 This feature allocates regions with increasing addresses
3203 within the region. calloc() is supported, but realloc()
3204 is not available. free() is supported but does nothing.
3205 The memory will be freed (or in fact just forgotten) when
3206 U-Boot relocates itself.
3208 - CONFIG_SYS_MALLOC_SIMPLE
3209 Provides a simple and small malloc() and calloc() for those
3210 boards which do not use the full malloc in SPL (which is
3211 enabled with CONFIG_SYS_SPL_MALLOC_START).
3213 - CONFIG_SYS_NONCACHED_MEMORY:
3214 Size of non-cached memory area. This area of memory will be
3215 typically located right below the malloc() area and mapped
3216 uncached in the MMU. This is useful for drivers that would
3217 otherwise require a lot of explicit cache maintenance. For
3218 some drivers it's also impossible to properly maintain the
3219 cache. For example if the regions that need to be flushed
3220 are not a multiple of the cache-line size, *and* padding
3221 cannot be allocated between the regions to align them (i.e.
3222 if the HW requires a contiguous array of regions, and the
3223 size of each region is not cache-aligned), then a flush of
3224 one region may result in overwriting data that hardware has
3225 written to another region in the same cache-line. This can
3226 happen for example in network drivers where descriptors for
3227 buffers are typically smaller than the CPU cache-line (e.g.
3228 16 bytes vs. 32 or 64 bytes).
3230 Non-cached memory is only supported on 32-bit ARM at present.
3232 - CONFIG_SYS_BOOTM_LEN:
3233 Normally compressed uImages are limited to an
3234 uncompressed size of 8 MBytes. If this is not enough,
3235 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3236 to adjust this setting to your needs.
3238 - CONFIG_SYS_BOOTMAPSZ:
3239 Maximum size of memory mapped by the startup code of
3240 the Linux kernel; all data that must be processed by
3241 the Linux kernel (bd_info, boot arguments, FDT blob if
3242 used) must be put below this limit, unless "bootm_low"
3243 environment variable is defined and non-zero. In such case
3244 all data for the Linux kernel must be between "bootm_low"
3245 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3246 variable "bootm_mapsize" will override the value of
3247 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3248 then the value in "bootm_size" will be used instead.
3250 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3251 Enable initrd_high functionality. If defined then the
3252 initrd_high feature is enabled and the bootm ramdisk subcommand
3255 - CONFIG_SYS_BOOT_GET_CMDLINE:
3256 Enables allocating and saving kernel cmdline in space between
3257 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3259 - CONFIG_SYS_BOOT_GET_KBD:
3260 Enables allocating and saving a kernel copy of the bd_info in
3261 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3263 - CONFIG_SYS_MAX_FLASH_BANKS:
3264 Max number of Flash memory banks
3266 - CONFIG_SYS_MAX_FLASH_SECT:
3267 Max number of sectors on a Flash chip
3269 - CONFIG_SYS_FLASH_ERASE_TOUT:
3270 Timeout for Flash erase operations (in ms)
3272 - CONFIG_SYS_FLASH_WRITE_TOUT:
3273 Timeout for Flash write operations (in ms)
3275 - CONFIG_SYS_FLASH_LOCK_TOUT
3276 Timeout for Flash set sector lock bit operation (in ms)
3278 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3279 Timeout for Flash clear lock bits operation (in ms)
3281 - CONFIG_SYS_FLASH_PROTECTION
3282 If defined, hardware flash sectors protection is used
3283 instead of U-Boot software protection.
3285 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3287 Enable TFTP transfers directly to flash memory;
3288 without this option such a download has to be
3289 performed in two steps: (1) download to RAM, and (2)
3290 copy from RAM to flash.
3292 The two-step approach is usually more reliable, since
3293 you can check if the download worked before you erase
3294 the flash, but in some situations (when system RAM is
3295 too limited to allow for a temporary copy of the
3296 downloaded image) this option may be very useful.
3298 - CONFIG_SYS_FLASH_CFI:
3299 Define if the flash driver uses extra elements in the
3300 common flash structure for storing flash geometry.
3302 - CONFIG_FLASH_CFI_DRIVER
3303 This option also enables the building of the cfi_flash driver
3304 in the drivers directory
3306 - CONFIG_FLASH_CFI_MTD
3307 This option enables the building of the cfi_mtd driver
3308 in the drivers directory. The driver exports CFI flash
3311 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3312 Use buffered writes to flash.
3314 - CONFIG_FLASH_SPANSION_S29WS_N
3315 s29ws-n MirrorBit flash has non-standard addresses for buffered
3318 - CONFIG_SYS_FLASH_QUIET_TEST
3319 If this option is defined, the common CFI flash doesn't
3320 print it's warning upon not recognized FLASH banks. This
3321 is useful, if some of the configured banks are only
3322 optionally available.
3324 - CONFIG_FLASH_SHOW_PROGRESS
3325 If defined (must be an integer), print out countdown
3326 digits and dots. Recommended value: 45 (9..1) for 80
3327 column displays, 15 (3..1) for 40 column displays.
3329 - CONFIG_FLASH_VERIFY
3330 If defined, the content of the flash (destination) is compared
3331 against the source after the write operation. An error message
3332 will be printed when the contents are not identical.
3333 Please note that this option is useless in nearly all cases,
3334 since such flash programming errors usually are detected earlier
3335 while unprotecting/erasing/programming. Please only enable
3336 this option if you really know what you are doing.
3338 - CONFIG_SYS_RX_ETH_BUFFER:
3339 Defines the number of Ethernet receive buffers. On some
3340 Ethernet controllers it is recommended to set this value
3341 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3342 buffers can be full shortly after enabling the interface
3343 on high Ethernet traffic.
3344 Defaults to 4 if not defined.
3346 - CONFIG_ENV_MAX_ENTRIES
3348 Maximum number of entries in the hash table that is used
3349 internally to store the environment settings. The default
3350 setting is supposed to be generous and should work in most
3351 cases. This setting can be used to tune behaviour; see
3352 lib/hashtable.c for details.
3354 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3355 - CONFIG_ENV_FLAGS_LIST_STATIC
3356 Enable validation of the values given to environment variables when
3357 calling env set. Variables can be restricted to only decimal,
3358 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3359 the variables can also be restricted to IP address or MAC address.
3361 The format of the list is:
3362 type_attribute = [s|d|x|b|i|m]
3363 access_attribute = [a|r|o|c]
3364 attributes = type_attribute[access_attribute]
3365 entry = variable_name[:attributes]
3368 The type attributes are:
3369 s - String (default)
3372 b - Boolean ([1yYtT|0nNfF])
3376 The access attributes are:
3382 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3383 Define this to a list (string) to define the ".flags"
3384 environment variable in the default or embedded environment.
3386 - CONFIG_ENV_FLAGS_LIST_STATIC
3387 Define this to a list (string) to define validation that
3388 should be done if an entry is not found in the ".flags"
3389 environment variable. To override a setting in the static
3390 list, simply add an entry for the same variable name to the
3393 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3394 regular expression. This allows multiple variables to define the same
3395 flags without explicitly listing them for each variable.
3397 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3398 If defined, don't allow the -f switch to env set override variable
3402 If stdint.h is available with your toolchain you can define this
3403 option to enable it. You can provide option 'USE_STDINT=1' when
3404 building U-Boot to enable this.
3406 The following definitions that deal with the placement and management
3407 of environment data (variable area); in general, we support the
3408 following configurations:
3410 - CONFIG_BUILD_ENVCRC:
3412 Builds up envcrc with the target environment so that external utils
3413 may easily extract it and embed it in final U-Boot images.
3415 BE CAREFUL! The first access to the environment happens quite early
3416 in U-Boot initialization (when we try to get the setting of for the
3417 console baudrate). You *MUST* have mapped your NVRAM area then, or
3420 Please note that even with NVRAM we still use a copy of the
3421 environment in RAM: we could work on NVRAM directly, but we want to
3422 keep settings there always unmodified except somebody uses "saveenv"
3423 to save the current settings.
3425 - CONFIG_ENV_IS_IN_DATAFLASH:
3427 Define this if you have a DataFlash memory device which you
3428 want to use for the environment.
3430 - CONFIG_ENV_OFFSET:
3434 These three #defines specify the offset and size of the
3435 environment area within the total memory of your DataFlash placed
3436 at the specified address.
3438 - CONFIG_ENV_IS_IN_SPI_FLASH:
3440 Define this if you have a SPI Flash memory device which you
3441 want to use for the environment.
3443 - CONFIG_ENV_OFFSET:
3446 These two #defines specify the offset and size of the
3447 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
3448 aligned to an erase sector boundary.
3450 - CONFIG_ENV_SECT_SIZE:
3452 Define the SPI flash's sector size.
3454 - CONFIG_ENV_OFFSET_REDUND (optional):
3456 This setting describes a second storage area of CONFIG_ENV_SIZE
3457 size used to hold a redundant copy of the environment data, so
3458 that there is a valid backup copy in case there is a power failure
3459 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
3460 aligned to an erase sector boundary.
3462 - CONFIG_ENV_SPI_BUS (optional):
3463 - CONFIG_ENV_SPI_CS (optional):
3465 Define the SPI bus and chip select. If not defined they will be 0.
3467 - CONFIG_ENV_SPI_MAX_HZ (optional):
3469 Define the SPI max work clock. If not defined then use 1MHz.
3471 - CONFIG_ENV_SPI_MODE (optional):
3473 Define the SPI work mode. If not defined then use SPI_MODE_3.
3475 - CONFIG_ENV_IS_IN_REMOTE:
3477 Define this if you have a remote memory space which you
3478 want to use for the local device's environment.
3483 These two #defines specify the address and size of the
3484 environment area within the remote memory space. The
3485 local device can get the environment from remote memory
3486 space by SRIO or PCIE links.
3488 BE CAREFUL! For some special cases, the local device can not use
3489 "saveenv" command. For example, the local device will get the
3490 environment stored in a remote NOR flash by SRIO or PCIE link,
3491 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3493 - CONFIG_NAND_ENV_DST
3495 Defines address in RAM to which the nand_spl code should copy the
3496 environment. If redundant environment is used, it will be copied to
3497 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3499 - CONFIG_ENV_IS_IN_FAT:
3500 Define this if you want to use the FAT file system for the environment.
3502 - FAT_ENV_INTERFACE:
3504 Define this to a string that is the name of the block device.
3506 - FAT_ENV_DEVICE_AND_PART:
3508 Define this to a string to specify the partition of the device. It can
3511 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
3512 - "D:P": device D partition P. Error occurs if device D has no
3515 - "D" or "D:": device D partition 1 if device D has partition
3516 table, or the whole device D if has no partition
3518 - "D:auto": first partition in device D with bootable flag set.
3519 If none, first valid partition in device D. If no
3520 partition table then means device D.
3524 It's a string of the FAT file name. This file use to store the
3528 This must be enabled. Otherwise it cannot save the environment file.
3530 Please note that the environment is read-only until the monitor
3531 has been relocated to RAM and a RAM copy of the environment has been
3532 created; also, when using EEPROM you will have to use getenv_f()
3533 until then to read environment variables.
3535 The environment is protected by a CRC32 checksum. Before the monitor
3536 is relocated into RAM, as a result of a bad CRC you will be working
3537 with the compiled-in default environment - *silently*!!! [This is
3538 necessary, because the first environment variable we need is the
3539 "baudrate" setting for the console - if we have a bad CRC, we don't
3540 have any device yet where we could complain.]
3542 Note: once the monitor has been relocated, then it will complain if
3543 the default environment is used; a new CRC is computed as soon as you
3544 use the "saveenv" command to store a valid environment.
3546 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3547 Echo the inverted Ethernet link state to the fault LED.
3549 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3550 also needs to be defined.
3552 - CONFIG_SYS_FAULT_MII_ADDR:
3553 MII address of the PHY to check for the Ethernet link state.
3555 - CONFIG_NS16550_MIN_FUNCTIONS:
3556 Define this if you desire to only have use of the NS16550_init
3557 and NS16550_putc functions for the serial driver located at
3558 drivers/serial/ns16550.c. This option is useful for saving
3559 space for already greatly restricted images, including but not
3560 limited to NAND_SPL configurations.
3562 - CONFIG_DISPLAY_BOARDINFO
3563 Display information about the board that U-Boot is running on
3564 when U-Boot starts up. The board function checkboard() is called
3567 - CONFIG_DISPLAY_BOARDINFO_LATE
3568 Similar to the previous option, but display this information
3569 later, once stdio is running and output goes to the LCD, if
3572 - CONFIG_BOARD_SIZE_LIMIT:
3573 Maximum size of the U-Boot image. When defined, the
3574 build system checks that the actual size does not
3577 Low Level (hardware related) configuration options:
3578 ---------------------------------------------------
3580 - CONFIG_SYS_CACHELINE_SIZE:
3581 Cache Line Size of the CPU.
3583 - CONFIG_SYS_CCSRBAR_DEFAULT:
3584 Default (power-on reset) physical address of CCSR on Freescale
3587 - CONFIG_SYS_CCSRBAR:
3588 Virtual address of CCSR. On a 32-bit build, this is typically
3589 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3591 - CONFIG_SYS_CCSRBAR_PHYS:
3592 Physical address of CCSR. CCSR can be relocated to a new
3593 physical address, if desired. In this case, this macro should
3594 be set to that address. Otherwise, it should be set to the
3595 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3596 is typically relocated on 36-bit builds. It is recommended
3597 that this macro be defined via the _HIGH and _LOW macros:
3599 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3600 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3602 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3603 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3604 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3605 used in assembly code, so it must not contain typecasts or
3606 integer size suffixes (e.g. "ULL").
3608 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3609 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3610 used in assembly code, so it must not contain typecasts or
3611 integer size suffixes (e.g. "ULL").
3613 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3614 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3615 forced to a value that ensures that CCSR is not relocated.
3617 - Floppy Disk Support:
3618 CONFIG_SYS_FDC_DRIVE_NUMBER
3620 the default drive number (default value 0)
3622 CONFIG_SYS_ISA_IO_STRIDE
3624 defines the spacing between FDC chipset registers
3627 CONFIG_SYS_ISA_IO_OFFSET
3629 defines the offset of register from address. It
3630 depends on which part of the data bus is connected to
3631 the FDC chipset. (default value 0)
3633 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3634 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3637 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3638 fdc_hw_init() is called at the beginning of the FDC
3639 setup. fdc_hw_init() must be provided by the board
3640 source code. It is used to make hardware-dependent
3644 Most IDE controllers were designed to be connected with PCI
3645 interface. Only few of them were designed for AHB interface.
3646 When software is doing ATA command and data transfer to
3647 IDE devices through IDE-AHB controller, some additional
3648 registers accessing to these kind of IDE-AHB controller
3651 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3652 DO NOT CHANGE unless you know exactly what you're
3653 doing! (11-4) [MPC8xx systems only]
3655 - CONFIG_SYS_INIT_RAM_ADDR:
3657 Start address of memory area that can be used for
3658 initial data and stack; please note that this must be
3659 writable memory that is working WITHOUT special
3660 initialization, i. e. you CANNOT use normal RAM which
3661 will become available only after programming the
3662 memory controller and running certain initialization
3665 U-Boot uses the following memory types:
3666 - MPC8xx: IMMR (internal memory of the CPU)
3668 - CONFIG_SYS_GBL_DATA_OFFSET:
3670 Offset of the initial data structure in the memory
3671 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3672 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3673 data is located at the end of the available space
3674 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3675 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3676 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3677 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3680 On the MPC824X (or other systems that use the data
3681 cache for initial memory) the address chosen for
3682 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3683 point to an otherwise UNUSED address space between
3684 the top of RAM and the start of the PCI space.
3686 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3688 - CONFIG_SYS_OR_TIMING_SDRAM:
3691 - CONFIG_SYS_MAMR_PTA:
3692 periodic timer for refresh
3694 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3695 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3696 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3697 CONFIG_SYS_BR1_PRELIM:
3698 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3700 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3701 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3702 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3703 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3705 - CONFIG_PCI_ENUM_ONLY
3706 Only scan through and get the devices on the buses.
3707 Don't do any setup work, presumably because someone or
3708 something has already done it, and we don't need to do it
3709 a second time. Useful for platforms that are pre-booted
3710 by coreboot or similar.
3712 - CONFIG_PCI_INDIRECT_BRIDGE:
3713 Enable support for indirect PCI bridges.
3716 Chip has SRIO or not
3719 Board has SRIO 1 port available
3722 Board has SRIO 2 port available
3724 - CONFIG_SRIO_PCIE_BOOT_MASTER
3725 Board can support master function for Boot from SRIO and PCIE
3727 - CONFIG_SYS_SRIOn_MEM_VIRT:
3728 Virtual Address of SRIO port 'n' memory region
3730 - CONFIG_SYS_SRIOn_MEM_PHYS:
3731 Physical Address of SRIO port 'n' memory region
3733 - CONFIG_SYS_SRIOn_MEM_SIZE:
3734 Size of SRIO port 'n' memory region
3736 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3737 Defined to tell the NAND controller that the NAND chip is using
3739 Not all NAND drivers use this symbol.
3740 Example of drivers that use it:
3741 - drivers/mtd/nand/ndfc.c
3742 - drivers/mtd/nand/mxc_nand.c
3744 - CONFIG_SYS_NDFC_EBC0_CFG
3745 Sets the EBC0_CFG register for the NDFC. If not defined
3746 a default value will be used.
3749 Get DDR timing information from an I2C EEPROM. Common
3750 with pluggable memory modules such as SODIMMs
3753 I2C address of the SPD EEPROM
3755 - CONFIG_SYS_SPD_BUS_NUM
3756 If SPD EEPROM is on an I2C bus other than the first
3757 one, specify here. Note that the value must resolve
3758 to something your driver can deal with.
3760 - CONFIG_SYS_DDR_RAW_TIMING
3761 Get DDR timing information from other than SPD. Common with
3762 soldered DDR chips onboard without SPD. DDR raw timing
3763 parameters are extracted from datasheet and hard-coded into
3764 header files or board specific files.
3766 - CONFIG_FSL_DDR_INTERACTIVE
3767 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3769 - CONFIG_FSL_DDR_SYNC_REFRESH
3770 Enable sync of refresh for multiple controllers.
3772 - CONFIG_FSL_DDR_BIST
3773 Enable built-in memory test for Freescale DDR controllers.
3775 - CONFIG_SYS_83XX_DDR_USES_CS0
3776 Only for 83xx systems. If specified, then DDR should
3777 be configured using CS0 and CS1 instead of CS2 and CS3.
3780 Enable RMII mode for all FECs.
3781 Note that this is a global option, we can't
3782 have one FEC in standard MII mode and another in RMII mode.
3784 - CONFIG_CRC32_VERIFY
3785 Add a verify option to the crc32 command.
3788 => crc32 -v <address> <count> <crc32>
3790 Where address/count indicate a memory area
3791 and crc32 is the correct crc32 which the
3795 Add the "loopw" memory command. This only takes effect if
3796 the memory commands are activated globally (CONFIG_CMD_MEM).
3799 Add the "mdc" and "mwc" memory commands. These are cyclic
3804 This command will print 4 bytes (10,11,12,13) each 500 ms.
3806 => mwc.l 100 12345678 10
3807 This command will write 12345678 to address 100 all 10 ms.
3809 This only takes effect if the memory commands are activated
3810 globally (CONFIG_CMD_MEM).
3812 - CONFIG_SKIP_LOWLEVEL_INIT
3813 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3814 low level initializations (like setting up the memory
3815 controller) are omitted and/or U-Boot does not
3816 relocate itself into RAM.
3818 Normally this variable MUST NOT be defined. The only
3819 exception is when U-Boot is loaded (to RAM) by some
3820 other boot loader or by a debugger which performs
3821 these initializations itself.
3823 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3824 [ARM926EJ-S only] This allows just the call to lowlevel_init()
3825 to be skipped. The normal CP15 init (such as enabling the
3826 instruction cache) is still performed.
3829 Modifies the behaviour of start.S when compiling a loader
3830 that is executed before the actual U-Boot. E.g. when
3831 compiling a NAND SPL.
3834 Modifies the behaviour of start.S when compiling a loader
3835 that is executed after the SPL and before the actual U-Boot.
3836 It is loaded by the SPL.
3838 - CONFIG_SYS_MPC85XX_NO_RESETVEC
3839 Only for 85xx systems. If this variable is specified, the section
3840 .resetvec is not kept and the section .bootpg is placed in the
3841 previous 4k of the .text section.
3843 - CONFIG_ARCH_MAP_SYSMEM
3844 Generally U-Boot (and in particular the md command) uses
3845 effective address. It is therefore not necessary to regard
3846 U-Boot address as virtual addresses that need to be translated
3847 to physical addresses. However, sandbox requires this, since
3848 it maintains its own little RAM buffer which contains all
3849 addressable memory. This option causes some memory accesses
3850 to be mapped through map_sysmem() / unmap_sysmem().
3852 - CONFIG_X86_RESET_VECTOR
3853 If defined, the x86 reset vector code is included. This is not
3854 needed when U-Boot is running from Coreboot.
3856 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
3857 Enables the RTC32K OSC on AM33xx based plattforms
3859 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3860 Option to disable subpage write in NAND driver
3861 driver that uses this:
3862 drivers/mtd/nand/davinci_nand.c
3864 Freescale QE/FMAN Firmware Support:
3865 -----------------------------------
3867 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3868 loading of "firmware", which is encoded in the QE firmware binary format.
3869 This firmware often needs to be loaded during U-Boot booting, so macros
3870 are used to identify the storage device (NOR flash, SPI, etc) and the address
3873 - CONFIG_SYS_FMAN_FW_ADDR
3874 The address in the storage device where the FMAN microcode is located. The
3875 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3878 - CONFIG_SYS_QE_FW_ADDR
3879 The address in the storage device where the QE microcode is located. The
3880 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3883 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3884 The maximum possible size of the firmware. The firmware binary format
3885 has a field that specifies the actual size of the firmware, but it
3886 might not be possible to read any part of the firmware unless some
3887 local storage is allocated to hold the entire firmware first.
3889 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3890 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3891 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3892 virtual address in NOR flash.
3894 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3895 Specifies that QE/FMAN firmware is located in NAND flash.
3896 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3898 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3899 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3900 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3902 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3903 Specifies that QE/FMAN firmware is located in the remote (master)
3904 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3905 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3906 window->master inbound window->master LAW->the ucode address in
3907 master's memory space.
3909 Freescale Layerscape Management Complex Firmware Support:
3910 ---------------------------------------------------------
3911 The Freescale Layerscape Management Complex (MC) supports the loading of
3913 This firmware often needs to be loaded during U-Boot booting, so macros
3914 are used to identify the storage device (NOR flash, SPI, etc) and the address
3917 - CONFIG_FSL_MC_ENET
3918 Enable the MC driver for Layerscape SoCs.
3920 Freescale Layerscape Debug Server Support:
3921 -------------------------------------------
3922 The Freescale Layerscape Debug Server Support supports the loading of
3923 "Debug Server firmware" and triggering SP boot-rom.
3924 This firmware often needs to be loaded during U-Boot booting.
3926 - CONFIG_SYS_MC_RSV_MEM_ALIGN
3927 Define alignment of reserved memory MC requires
3932 In order to achieve reproducible builds, timestamps used in the U-Boot build
3933 process have to be set to a fixed value.
3935 This is done using the SOURCE_DATE_EPOCH environment variable.
3936 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3937 option for U-Boot or an environment variable in U-Boot.
3939 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3941 Building the Software:
3942 ======================
3944 Building U-Boot has been tested in several native build environments
3945 and in many different cross environments. Of course we cannot support
3946 all possibly existing versions of cross development tools in all
3947 (potentially obsolete) versions. In case of tool chain problems we
3948 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3949 which is extensively used to build and test U-Boot.
3951 If you are not using a native environment, it is assumed that you
3952 have GNU cross compiling tools available in your path. In this case,
3953 you must set the environment variable CROSS_COMPILE in your shell.
3954 Note that no changes to the Makefile or any other source files are
3955 necessary. For example using the ELDK on a 4xx CPU, please enter:
3957 $ CROSS_COMPILE=ppc_4xx-
3958 $ export CROSS_COMPILE
3960 Note: If you wish to generate Windows versions of the utilities in
3961 the tools directory you can use the MinGW toolchain
3962 (http://www.mingw.org). Set your HOST tools to the MinGW
3963 toolchain and execute 'make tools'. For example:
3965 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3967 Binaries such as tools/mkimage.exe will be created which can
3968 be executed on computers running Windows.
3970 U-Boot is intended to be simple to build. After installing the
3971 sources you must configure U-Boot for one specific board type. This
3976 where "NAME_defconfig" is the name of one of the existing configu-
3977 rations; see boards.cfg for supported names.
3979 Note: for some board special configuration names may exist; check if
3980 additional information is available from the board vendor; for
3981 instance, the TQM823L systems are available without (standard)
3982 or with LCD support. You can select such additional "features"
3983 when choosing the configuration, i. e.
3985 make TQM823L_defconfig
3986 - will configure for a plain TQM823L, i. e. no LCD support
3988 make TQM823L_LCD_defconfig
3989 - will configure for a TQM823L with U-Boot console on LCD
3994 Finally, type "make all", and you should get some working U-Boot
3995 images ready for download to / installation on your system:
3997 - "u-boot.bin" is a raw binary image
3998 - "u-boot" is an image in ELF binary format
3999 - "u-boot.srec" is in Motorola S-Record format
4001 By default the build is performed locally and the objects are saved
4002 in the source directory. One of the two methods can be used to change
4003 this behavior and build U-Boot to some external directory:
4005 1. Add O= to the make command line invocations:
4007 make O=/tmp/build distclean
4008 make O=/tmp/build NAME_defconfig
4009 make O=/tmp/build all
4011 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4013 export KBUILD_OUTPUT=/tmp/build
4018 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4022 Please be aware that the Makefiles assume you are using GNU make, so
4023 for instance on NetBSD you might need to use "gmake" instead of
4027 If the system board that you have is not listed, then you will need
4028 to port U-Boot to your hardware platform. To do this, follow these
4031 1. Create a new directory to hold your board specific code. Add any
4032 files you need. In your board directory, you will need at least
4033 the "Makefile" and a "<board>.c".
4034 2. Create a new configuration file "include/configs/<board>.h" for
4036 3. If you're porting U-Boot to a new CPU, then also create a new
4037 directory to hold your CPU specific code. Add any files you need.
4038 4. Run "make <board>_defconfig" with your new name.
4039 5. Type "make", and you should get a working "u-boot.srec" file
4040 to be installed on your target system.
4041 6. Debug and solve any problems that might arise.
4042 [Of course, this last step is much harder than it sounds.]
4045 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4046 ==============================================================
4048 If you have modified U-Boot sources (for instance added a new board
4049 or support for new devices, a new CPU, etc.) you are expected to
4050 provide feedback to the other developers. The feedback normally takes
4051 the form of a "patch", i. e. a context diff against a certain (latest
4052 official or latest in the git repository) version of U-Boot sources.
4054 But before you submit such a patch, please verify that your modifi-
4055 cation did not break existing code. At least make sure that *ALL* of
4056 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4057 just run the buildman script (tools/buildman/buildman), which will
4058 configure and build U-Boot for ALL supported system. Be warned, this
4059 will take a while. Please see the buildman README, or run 'buildman -H'
4063 See also "U-Boot Porting Guide" below.
4066 Monitor Commands - Overview:
4067 ============================
4069 go - start application at address 'addr'
4070 run - run commands in an environment variable
4071 bootm - boot application image from memory
4072 bootp - boot image via network using BootP/TFTP protocol
4073 bootz - boot zImage from memory
4074 tftpboot- boot image via network using TFTP protocol
4075 and env variables "ipaddr" and "serverip"
4076 (and eventually "gatewayip")
4077 tftpput - upload a file via network using TFTP protocol
4078 rarpboot- boot image via network using RARP/TFTP protocol
4079 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4080 loads - load S-Record file over serial line
4081 loadb - load binary file over serial line (kermit mode)
4083 mm - memory modify (auto-incrementing)
4084 nm - memory modify (constant address)
4085 mw - memory write (fill)
4087 cmp - memory compare
4088 crc32 - checksum calculation
4089 i2c - I2C sub-system
4090 sspi - SPI utility commands
4091 base - print or set address offset
4092 printenv- print environment variables
4093 setenv - set environment variables
4094 saveenv - save environment variables to persistent storage
4095 protect - enable or disable FLASH write protection
4096 erase - erase FLASH memory
4097 flinfo - print FLASH memory information
4098 nand - NAND memory operations (see doc/README.nand)
4099 bdinfo - print Board Info structure
4100 iminfo - print header information for application image
4101 coninfo - print console devices and informations
4102 ide - IDE sub-system
4103 loop - infinite loop on address range
4104 loopw - infinite write loop on address range
4105 mtest - simple RAM test
4106 icache - enable or disable instruction cache
4107 dcache - enable or disable data cache
4108 reset - Perform RESET of the CPU
4109 echo - echo args to console
4110 version - print monitor version
4111 help - print online help
4112 ? - alias for 'help'
4115 Monitor Commands - Detailed Description:
4116 ========================================
4120 For now: just type "help <command>".
4123 Environment Variables:
4124 ======================
4126 U-Boot supports user configuration using Environment Variables which
4127 can be made persistent by saving to Flash memory.
4129 Environment Variables are set using "setenv", printed using
4130 "printenv", and saved to Flash using "saveenv". Using "setenv"
4131 without a value can be used to delete a variable from the
4132 environment. As long as you don't save the environment you are
4133 working with an in-memory copy. In case the Flash area containing the
4134 environment is erased by accident, a default environment is provided.
4136 Some configuration options can be set using Environment Variables.
4138 List of environment variables (most likely not complete):
4140 baudrate - see CONFIG_BAUDRATE
4142 bootdelay - see CONFIG_BOOTDELAY
4144 bootcmd - see CONFIG_BOOTCOMMAND
4146 bootargs - Boot arguments when booting an RTOS image
4148 bootfile - Name of the image to load with TFTP
4150 bootm_low - Memory range available for image processing in the bootm
4151 command can be restricted. This variable is given as
4152 a hexadecimal number and defines lowest address allowed
4153 for use by the bootm command. See also "bootm_size"
4154 environment variable. Address defined by "bootm_low" is
4155 also the base of the initial memory mapping for the Linux
4156 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4159 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4160 This variable is given as a hexadecimal number and it
4161 defines the size of the memory region starting at base
4162 address bootm_low that is accessible by the Linux kernel
4163 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4164 as the default value if it is defined, and bootm_size is
4167 bootm_size - Memory range available for image processing in the bootm
4168 command can be restricted. This variable is given as
4169 a hexadecimal number and defines the size of the region
4170 allowed for use by the bootm command. See also "bootm_low"
4171 environment variable.
4173 updatefile - Location of the software update file on a TFTP server, used
4174 by the automatic software update feature. Please refer to
4175 documentation in doc/README.update for more details.
4177 autoload - if set to "no" (any string beginning with 'n'),
4178 "bootp" will just load perform a lookup of the
4179 configuration from the BOOTP server, but not try to
4180 load any image using TFTP
4182 autostart - if set to "yes", an image loaded using the "bootp",
4183 "rarpboot", "tftpboot" or "diskboot" commands will
4184 be automatically started (by internally calling
4187 If set to "no", a standalone image passed to the
4188 "bootm" command will be copied to the load address
4189 (and eventually uncompressed), but NOT be started.
4190 This can be used to load and uncompress arbitrary
4193 fdt_high - if set this restricts the maximum address that the
4194 flattened device tree will be copied into upon boot.
4195 For example, if you have a system with 1 GB memory
4196 at physical address 0x10000000, while Linux kernel
4197 only recognizes the first 704 MB as low memory, you
4198 may need to set fdt_high as 0x3C000000 to have the
4199 device tree blob be copied to the maximum address
4200 of the 704 MB low memory, so that Linux kernel can
4201 access it during the boot procedure.
4203 If this is set to the special value 0xFFFFFFFF then
4204 the fdt will not be copied at all on boot. For this
4205 to work it must reside in writable memory, have
4206 sufficient padding on the end of it for u-boot to
4207 add the information it needs into it, and the memory
4208 must be accessible by the kernel.
4210 fdtcontroladdr- if set this is the address of the control flattened
4211 device tree used by U-Boot when CONFIG_OF_CONTROL is
4214 i2cfast - (PPC405GP|PPC405EP only)
4215 if set to 'y' configures Linux I2C driver for fast
4216 mode (400kHZ). This environment variable is used in
4217 initialization code. So, for changes to be effective
4218 it must be saved and board must be reset.
4220 initrd_high - restrict positioning of initrd images:
4221 If this variable is not set, initrd images will be
4222 copied to the highest possible address in RAM; this
4223 is usually what you want since it allows for
4224 maximum initrd size. If for some reason you want to
4225 make sure that the initrd image is loaded below the
4226 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4227 variable to a value of "no" or "off" or "0".
4228 Alternatively, you can set it to a maximum upper
4229 address to use (U-Boot will still check that it
4230 does not overwrite the U-Boot stack and data).
4232 For instance, when you have a system with 16 MB
4233 RAM, and want to reserve 4 MB from use by Linux,
4234 you can do this by adding "mem=12M" to the value of
4235 the "bootargs" variable. However, now you must make
4236 sure that the initrd image is placed in the first
4237 12 MB as well - this can be done with
4239 setenv initrd_high 00c00000
4241 If you set initrd_high to 0xFFFFFFFF, this is an
4242 indication to U-Boot that all addresses are legal
4243 for the Linux kernel, including addresses in flash
4244 memory. In this case U-Boot will NOT COPY the
4245 ramdisk at all. This may be useful to reduce the
4246 boot time on your system, but requires that this
4247 feature is supported by your Linux kernel.
4249 ipaddr - IP address; needed for tftpboot command
4251 loadaddr - Default load address for commands like "bootp",
4252 "rarpboot", "tftpboot", "loadb" or "diskboot"
4254 loads_echo - see CONFIG_LOADS_ECHO
4256 serverip - TFTP server IP address; needed for tftpboot command
4258 bootretry - see CONFIG_BOOT_RETRY_TIME
4260 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4262 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4264 ethprime - controls which interface is used first.
4266 ethact - controls which interface is currently active.
4267 For example you can do the following
4269 => setenv ethact FEC
4270 => ping 192.168.0.1 # traffic sent on FEC
4271 => setenv ethact SCC
4272 => ping 10.0.0.1 # traffic sent on SCC
4274 ethrotate - When set to "no" U-Boot does not go through all
4275 available network interfaces.
4276 It just stays at the currently selected interface.
4278 netretry - When set to "no" each network operation will
4279 either succeed or fail without retrying.
4280 When set to "once" the network operation will
4281 fail when all the available network interfaces
4282 are tried once without success.
4283 Useful on scripts which control the retry operation
4286 npe_ucode - set load address for the NPE microcode
4288 silent_linux - If set then Linux will be told to boot silently, by
4289 changing the console to be empty. If "yes" it will be
4290 made silent. If "no" it will not be made silent. If
4291 unset, then it will be made silent if the U-Boot console
4294 tftpsrcp - If this is set, the value is used for TFTP's
4297 tftpdstp - If this is set, the value is used for TFTP's UDP
4298 destination port instead of the Well Know Port 69.
4300 tftpblocksize - Block size to use for TFTP transfers; if not set,
4301 we use the TFTP server's default block size
4303 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4304 seconds, minimum value is 1000 = 1 second). Defines
4305 when a packet is considered to be lost so it has to
4306 be retransmitted. The default is 5000 = 5 seconds.
4307 Lowering this value may make downloads succeed
4308 faster in networks with high packet loss rates or
4309 with unreliable TFTP servers.
4311 tftptimeoutcountmax - maximum count of TFTP timeouts (no
4312 unit, minimum value = 0). Defines how many timeouts
4313 can happen during a single file transfer before that
4314 transfer is aborted. The default is 10, and 0 means
4315 'no timeouts allowed'. Increasing this value may help
4316 downloads succeed with high packet loss rates, or with
4317 unreliable TFTP servers or client hardware.
4319 vlan - When set to a value < 4095 the traffic over
4320 Ethernet is encapsulated/received over 802.1q
4323 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
4324 Unsigned value, in milliseconds. If not set, the period will
4325 be either the default (28000), or a value based on
4326 CONFIG_NET_RETRY_COUNT, if defined. This value has
4327 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
4329 The following image location variables contain the location of images
4330 used in booting. The "Image" column gives the role of the image and is
4331 not an environment variable name. The other columns are environment
4332 variable names. "File Name" gives the name of the file on a TFTP
4333 server, "RAM Address" gives the location in RAM the image will be
4334 loaded to, and "Flash Location" gives the image's address in NOR
4335 flash or offset in NAND flash.
4337 *Note* - these variables don't have to be defined for all boards, some
4338 boards currently use other variables for these purposes, and some
4339 boards use these variables for other purposes.
4341 Image File Name RAM Address Flash Location
4342 ----- --------- ----------- --------------
4343 u-boot u-boot u-boot_addr_r u-boot_addr
4344 Linux kernel bootfile kernel_addr_r kernel_addr
4345 device tree blob fdtfile fdt_addr_r fdt_addr
4346 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4348 The following environment variables may be used and automatically
4349 updated by the network boot commands ("bootp" and "rarpboot"),
4350 depending the information provided by your boot server:
4352 bootfile - see above
4353 dnsip - IP address of your Domain Name Server
4354 dnsip2 - IP address of your secondary Domain Name Server
4355 gatewayip - IP address of the Gateway (Router) to use
4356 hostname - Target hostname
4358 netmask - Subnet Mask
4359 rootpath - Pathname of the root filesystem on the NFS server
4360 serverip - see above
4363 There are two special Environment Variables:
4365 serial# - contains hardware identification information such
4366 as type string and/or serial number
4367 ethaddr - Ethernet address
4369 These variables can be set only once (usually during manufacturing of
4370 the board). U-Boot refuses to delete or overwrite these variables
4371 once they have been set once.
4374 Further special Environment Variables:
4376 ver - Contains the U-Boot version string as printed
4377 with the "version" command. This variable is
4378 readonly (see CONFIG_VERSION_VARIABLE).
4381 Please note that changes to some configuration parameters may take
4382 only effect after the next boot (yes, that's just like Windoze :-).
4385 Callback functions for environment variables:
4386 ---------------------------------------------
4388 For some environment variables, the behavior of u-boot needs to change
4389 when their values are changed. This functionality allows functions to
4390 be associated with arbitrary variables. On creation, overwrite, or
4391 deletion, the callback will provide the opportunity for some side
4392 effect to happen or for the change to be rejected.
4394 The callbacks are named and associated with a function using the
4395 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4397 These callbacks are associated with variables in one of two ways. The
4398 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4399 in the board configuration to a string that defines a list of
4400 associations. The list must be in the following format:
4402 entry = variable_name[:callback_name]
4405 If the callback name is not specified, then the callback is deleted.
4406 Spaces are also allowed anywhere in the list.
4408 Callbacks can also be associated by defining the ".callbacks" variable
4409 with the same list format above. Any association in ".callbacks" will
4410 override any association in the static list. You can define
4411 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4412 ".callbacks" environment variable in the default or embedded environment.
4414 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
4415 regular expression. This allows multiple variables to be connected to
4416 the same callback without explicitly listing them all out.
4419 Command Line Parsing:
4420 =====================
4422 There are two different command line parsers available with U-Boot:
4423 the old "simple" one, and the much more powerful "hush" shell:
4425 Old, simple command line parser:
4426 --------------------------------
4428 - supports environment variables (through setenv / saveenv commands)
4429 - several commands on one line, separated by ';'
4430 - variable substitution using "... ${name} ..." syntax
4431 - special characters ('$', ';') can be escaped by prefixing with '\',
4433 setenv bootcmd bootm \${address}
4434 - You can also escape text by enclosing in single apostrophes, for example:
4435 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4440 - similar to Bourne shell, with control structures like
4441 if...then...else...fi, for...do...done; while...do...done,
4442 until...do...done, ...
4443 - supports environment ("global") variables (through setenv / saveenv
4444 commands) and local shell variables (through standard shell syntax
4445 "name=value"); only environment variables can be used with "run"
4451 (1) If a command line (or an environment variable executed by a "run"
4452 command) contains several commands separated by semicolon, and
4453 one of these commands fails, then the remaining commands will be
4456 (2) If you execute several variables with one call to run (i. e.
4457 calling run with a list of variables as arguments), any failing
4458 command will cause "run" to terminate, i. e. the remaining
4459 variables are not executed.
4461 Note for Redundant Ethernet Interfaces:
4462 =======================================
4464 Some boards come with redundant Ethernet interfaces; U-Boot supports
4465 such configurations and is capable of automatic selection of a
4466 "working" interface when needed. MAC assignment works as follows:
4468 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4469 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4470 "eth1addr" (=>eth1), "eth2addr", ...
4472 If the network interface stores some valid MAC address (for instance
4473 in SROM), this is used as default address if there is NO correspon-
4474 ding setting in the environment; if the corresponding environment
4475 variable is set, this overrides the settings in the card; that means:
4477 o If the SROM has a valid MAC address, and there is no address in the
4478 environment, the SROM's address is used.
4480 o If there is no valid address in the SROM, and a definition in the
4481 environment exists, then the value from the environment variable is
4484 o If both the SROM and the environment contain a MAC address, and
4485 both addresses are the same, this MAC address is used.
4487 o If both the SROM and the environment contain a MAC address, and the
4488 addresses differ, the value from the environment is used and a
4491 o If neither SROM nor the environment contain a MAC address, an error
4492 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4493 a random, locally-assigned MAC is used.
4495 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4496 will be programmed into hardware as part of the initialization process. This
4497 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4498 The naming convention is as follows:
4499 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4504 U-Boot is capable of booting (and performing other auxiliary operations on)
4505 images in two formats:
4507 New uImage format (FIT)
4508 -----------------------
4510 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4511 to Flattened Device Tree). It allows the use of images with multiple
4512 components (several kernels, ramdisks, etc.), with contents protected by
4513 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4519 Old image format is based on binary files which can be basically anything,
4520 preceded by a special header; see the definitions in include/image.h for
4521 details; basically, the header defines the following image properties:
4523 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4524 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4525 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4526 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4528 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
4529 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4530 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4531 * Compression Type (uncompressed, gzip, bzip2)
4537 The header is marked by a special Magic Number, and both the header
4538 and the data portions of the image are secured against corruption by
4545 Although U-Boot should support any OS or standalone application
4546 easily, the main focus has always been on Linux during the design of
4549 U-Boot includes many features that so far have been part of some
4550 special "boot loader" code within the Linux kernel. Also, any
4551 "initrd" images to be used are no longer part of one big Linux image;
4552 instead, kernel and "initrd" are separate images. This implementation
4553 serves several purposes:
4555 - the same features can be used for other OS or standalone
4556 applications (for instance: using compressed images to reduce the
4557 Flash memory footprint)
4559 - it becomes much easier to port new Linux kernel versions because
4560 lots of low-level, hardware dependent stuff are done by U-Boot
4562 - the same Linux kernel image can now be used with different "initrd"
4563 images; of course this also means that different kernel images can
4564 be run with the same "initrd". This makes testing easier (you don't
4565 have to build a new "zImage.initrd" Linux image when you just
4566 change a file in your "initrd"). Also, a field-upgrade of the
4567 software is easier now.
4573 Porting Linux to U-Boot based systems:
4574 ---------------------------------------
4576 U-Boot cannot save you from doing all the necessary modifications to
4577 configure the Linux device drivers for use with your target hardware
4578 (no, we don't intend to provide a full virtual machine interface to
4581 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4583 Just make sure your machine specific header file (for instance
4584 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4585 Information structure as we define in include/asm-<arch>/u-boot.h,
4586 and make sure that your definition of IMAP_ADDR uses the same value
4587 as your U-Boot configuration in CONFIG_SYS_IMMR.
4589 Note that U-Boot now has a driver model, a unified model for drivers.
4590 If you are adding a new driver, plumb it into driver model. If there
4591 is no uclass available, you are encouraged to create one. See
4595 Configuring the Linux kernel:
4596 -----------------------------
4598 No specific requirements for U-Boot. Make sure you have some root
4599 device (initial ramdisk, NFS) for your target system.
4602 Building a Linux Image:
4603 -----------------------
4605 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4606 not used. If you use recent kernel source, a new build target
4607 "uImage" will exist which automatically builds an image usable by
4608 U-Boot. Most older kernels also have support for a "pImage" target,
4609 which was introduced for our predecessor project PPCBoot and uses a
4610 100% compatible format.
4614 make TQM850L_defconfig
4619 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4620 encapsulate a compressed Linux kernel image with header information,
4621 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4623 * build a standard "vmlinux" kernel image (in ELF binary format):
4625 * convert the kernel into a raw binary image:
4627 ${CROSS_COMPILE}-objcopy -O binary \
4628 -R .note -R .comment \
4629 -S vmlinux linux.bin
4631 * compress the binary image:
4635 * package compressed binary image for U-Boot:
4637 mkimage -A ppc -O linux -T kernel -C gzip \
4638 -a 0 -e 0 -n "Linux Kernel Image" \
4639 -d linux.bin.gz uImage
4642 The "mkimage" tool can also be used to create ramdisk images for use
4643 with U-Boot, either separated from the Linux kernel image, or
4644 combined into one file. "mkimage" encapsulates the images with a 64
4645 byte header containing information about target architecture,
4646 operating system, image type, compression method, entry points, time
4647 stamp, CRC32 checksums, etc.
4649 "mkimage" can be called in two ways: to verify existing images and
4650 print the header information, or to build new images.
4652 In the first form (with "-l" option) mkimage lists the information
4653 contained in the header of an existing U-Boot image; this includes
4654 checksum verification:
4656 tools/mkimage -l image
4657 -l ==> list image header information
4659 The second form (with "-d" option) is used to build a U-Boot image
4660 from a "data file" which is used as image payload:
4662 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4663 -n name -d data_file image
4664 -A ==> set architecture to 'arch'
4665 -O ==> set operating system to 'os'
4666 -T ==> set image type to 'type'
4667 -C ==> set compression type 'comp'
4668 -a ==> set load address to 'addr' (hex)
4669 -e ==> set entry point to 'ep' (hex)
4670 -n ==> set image name to 'name'
4671 -d ==> use image data from 'datafile'
4673 Right now, all Linux kernels for PowerPC systems use the same load
4674 address (0x00000000), but the entry point address depends on the
4677 - 2.2.x kernels have the entry point at 0x0000000C,
4678 - 2.3.x and later kernels have the entry point at 0x00000000.
4680 So a typical call to build a U-Boot image would read:
4682 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4683 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4684 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4685 > examples/uImage.TQM850L
4686 Image Name: 2.4.4 kernel for TQM850L
4687 Created: Wed Jul 19 02:34:59 2000
4688 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4689 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4690 Load Address: 0x00000000
4691 Entry Point: 0x00000000
4693 To verify the contents of the image (or check for corruption):
4695 -> tools/mkimage -l examples/uImage.TQM850L
4696 Image Name: 2.4.4 kernel for TQM850L
4697 Created: Wed Jul 19 02:34:59 2000
4698 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4699 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4700 Load Address: 0x00000000
4701 Entry Point: 0x00000000
4703 NOTE: for embedded systems where boot time is critical you can trade
4704 speed for memory and install an UNCOMPRESSED image instead: this
4705 needs more space in Flash, but boots much faster since it does not
4706 need to be uncompressed:
4708 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4709 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4710 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4711 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4712 > examples/uImage.TQM850L-uncompressed
4713 Image Name: 2.4.4 kernel for TQM850L
4714 Created: Wed Jul 19 02:34:59 2000
4715 Image Type: PowerPC Linux Kernel Image (uncompressed)
4716 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4717 Load Address: 0x00000000
4718 Entry Point: 0x00000000
4721 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4722 when your kernel is intended to use an initial ramdisk:
4724 -> tools/mkimage -n 'Simple Ramdisk Image' \
4725 > -A ppc -O linux -T ramdisk -C gzip \
4726 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4727 Image Name: Simple Ramdisk Image
4728 Created: Wed Jan 12 14:01:50 2000
4729 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4730 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4731 Load Address: 0x00000000
4732 Entry Point: 0x00000000
4734 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4735 option performs the converse operation of the mkimage's second form (the "-d"
4736 option). Given an image built by mkimage, the dumpimage extracts a "data file"
4739 tools/dumpimage -i image -T type -p position data_file
4740 -i ==> extract from the 'image' a specific 'data_file'
4741 -T ==> set image type to 'type'
4742 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
4745 Installing a Linux Image:
4746 -------------------------
4748 To downloading a U-Boot image over the serial (console) interface,
4749 you must convert the image to S-Record format:
4751 objcopy -I binary -O srec examples/image examples/image.srec
4753 The 'objcopy' does not understand the information in the U-Boot
4754 image header, so the resulting S-Record file will be relative to
4755 address 0x00000000. To load it to a given address, you need to
4756 specify the target address as 'offset' parameter with the 'loads'
4759 Example: install the image to address 0x40100000 (which on the
4760 TQM8xxL is in the first Flash bank):
4762 => erase 40100000 401FFFFF
4768 ## Ready for S-Record download ...
4769 ~>examples/image.srec
4770 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4772 15989 15990 15991 15992
4773 [file transfer complete]
4775 ## Start Addr = 0x00000000
4778 You can check the success of the download using the 'iminfo' command;
4779 this includes a checksum verification so you can be sure no data
4780 corruption happened:
4784 ## Checking Image at 40100000 ...
4785 Image Name: 2.2.13 for initrd on TQM850L
4786 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4787 Data Size: 335725 Bytes = 327 kB = 0 MB
4788 Load Address: 00000000
4789 Entry Point: 0000000c
4790 Verifying Checksum ... OK
4796 The "bootm" command is used to boot an application that is stored in
4797 memory (RAM or Flash). In case of a Linux kernel image, the contents
4798 of the "bootargs" environment variable is passed to the kernel as
4799 parameters. You can check and modify this variable using the
4800 "printenv" and "setenv" commands:
4803 => printenv bootargs
4804 bootargs=root=/dev/ram
4806 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4808 => printenv bootargs
4809 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4812 ## Booting Linux kernel at 40020000 ...
4813 Image Name: 2.2.13 for NFS on TQM850L
4814 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4815 Data Size: 381681 Bytes = 372 kB = 0 MB
4816 Load Address: 00000000
4817 Entry Point: 0000000c
4818 Verifying Checksum ... OK
4819 Uncompressing Kernel Image ... OK
4820 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
4821 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4822 time_init: decrementer frequency = 187500000/60
4823 Calibrating delay loop... 49.77 BogoMIPS
4824 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4827 If you want to boot a Linux kernel with initial RAM disk, you pass
4828 the memory addresses of both the kernel and the initrd image (PPBCOOT
4829 format!) to the "bootm" command:
4831 => imi 40100000 40200000
4833 ## Checking Image at 40100000 ...
4834 Image Name: 2.2.13 for initrd on TQM850L
4835 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4836 Data Size: 335725 Bytes = 327 kB = 0 MB
4837 Load Address: 00000000
4838 Entry Point: 0000000c
4839 Verifying Checksum ... OK
4841 ## Checking Image at 40200000 ...
4842 Image Name: Simple Ramdisk Image
4843 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4844 Data Size: 566530 Bytes = 553 kB = 0 MB
4845 Load Address: 00000000
4846 Entry Point: 00000000
4847 Verifying Checksum ... OK
4849 => bootm 40100000 40200000
4850 ## Booting Linux kernel at 40100000 ...
4851 Image Name: 2.2.13 for initrd on TQM850L
4852 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4853 Data Size: 335725 Bytes = 327 kB = 0 MB
4854 Load Address: 00000000
4855 Entry Point: 0000000c
4856 Verifying Checksum ... OK
4857 Uncompressing Kernel Image ... OK
4858 ## Loading RAMDisk Image at 40200000 ...
4859 Image Name: Simple Ramdisk Image
4860 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4861 Data Size: 566530 Bytes = 553 kB = 0 MB
4862 Load Address: 00000000
4863 Entry Point: 00000000
4864 Verifying Checksum ... OK
4865 Loading Ramdisk ... OK
4866 Linux version 2.2.13 (
[email protected]) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
4867 Boot arguments: root=/dev/ram
4868 time_init: decrementer frequency = 187500000/60
4869 Calibrating delay loop... 49.77 BogoMIPS
4871 RAMDISK: Compressed image found at block 0
4872 VFS: Mounted root (ext2 filesystem).
4876 Boot Linux and pass a flat device tree:
4879 First, U-Boot must be compiled with the appropriate defines. See the section
4880 titled "Linux Kernel Interface" above for a more in depth explanation. The
4881 following is an example of how to start a kernel and pass an updated
4887 oft=oftrees/mpc8540ads.dtb
4888 => tftp $oftaddr $oft
4889 Speed: 1000, full duplex
4891 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4892 Filename 'oftrees/mpc8540ads.dtb'.
4893 Load address: 0x300000
4896 Bytes transferred = 4106 (100a hex)
4897 => tftp $loadaddr $bootfile
4898 Speed: 1000, full duplex
4900 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4902 Load address: 0x200000
4903 Loading:############
4905 Bytes transferred = 1029407 (fb51f hex)
4910 => bootm $loadaddr - $oftaddr
4911 ## Booting image at 00200000 ...
4912 Image Name: Linux-2.6.17-dirty
4913 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4914 Data Size: 1029343 Bytes = 1005.2 kB
4915 Load Address: 00000000
4916 Entry Point: 00000000
4917 Verifying Checksum ... OK
4918 Uncompressing Kernel Image ... OK
4919 Booting using flat device tree at 0x300000
4920 Using MPC85xx ADS machine description
4921 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4925 More About U-Boot Image Types:
4926 ------------------------------
4928 U-Boot supports the following image types:
4930 "Standalone Programs" are directly runnable in the environment
4931 provided by U-Boot; it is expected that (if they behave
4932 well) you can continue to work in U-Boot after return from
4933 the Standalone Program.
4934 "OS Kernel Images" are usually images of some Embedded OS which
4935 will take over control completely. Usually these programs
4936 will install their own set of exception handlers, device
4937 drivers, set up the MMU, etc. - this means, that you cannot
4938 expect to re-enter U-Boot except by resetting the CPU.
4939 "RAMDisk Images" are more or less just data blocks, and their
4940 parameters (address, size) are passed to an OS kernel that is
4942 "Multi-File Images" contain several images, typically an OS
4943 (Linux) kernel image and one or more data images like
4944 RAMDisks. This construct is useful for instance when you want
4945 to boot over the network using BOOTP etc., where the boot
4946 server provides just a single image file, but you want to get
4947 for instance an OS kernel and a RAMDisk image.
4949 "Multi-File Images" start with a list of image sizes, each
4950 image size (in bytes) specified by an "uint32_t" in network
4951 byte order. This list is terminated by an "(uint32_t)0".
4952 Immediately after the terminating 0 follow the images, one by
4953 one, all aligned on "uint32_t" boundaries (size rounded up to
4954 a multiple of 4 bytes).
4956 "Firmware Images" are binary images containing firmware (like
4957 U-Boot or FPGA images) which usually will be programmed to
4960 "Script files" are command sequences that will be executed by
4961 U-Boot's command interpreter; this feature is especially
4962 useful when you configure U-Boot to use a real shell (hush)
4963 as command interpreter.
4965 Booting the Linux zImage:
4966 -------------------------
4968 On some platforms, it's possible to boot Linux zImage. This is done
4969 using the "bootz" command. The syntax of "bootz" command is the same
4970 as the syntax of "bootm" command.
4972 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
4973 kernel with raw initrd images. The syntax is slightly different, the
4974 address of the initrd must be augmented by it's size, in the following
4975 format: "<initrd addres>:<initrd size>".
4981 One of the features of U-Boot is that you can dynamically load and
4982 run "standalone" applications, which can use some resources of
4983 U-Boot like console I/O functions or interrupt services.
4985 Two simple examples are included with the sources:
4990 'examples/hello_world.c' contains a small "Hello World" Demo
4991 application; it is automatically compiled when you build U-Boot.
4992 It's configured to run at address 0x00040004, so you can play with it
4996 ## Ready for S-Record download ...
4997 ~>examples/hello_world.srec
4998 1 2 3 4 5 6 7 8 9 10 11 ...
4999 [file transfer complete]
5001 ## Start Addr = 0x00040004
5003 => go 40004 Hello World! This is a test.
5004 ## Starting application at 0x00040004 ...
5015 Hit any key to exit ...
5017 ## Application terminated, rc = 0x0
5019 Another example, which demonstrates how to register a CPM interrupt
5020 handler with the U-Boot code, can be found in 'examples/timer.c'.
5021 Here, a CPM timer is set up to generate an interrupt every second.
5022 The interrupt service routine is trivial, just printing a '.'
5023 character, but this is just a demo program. The application can be
5024 controlled by the following keys:
5026 ? - print current values og the CPM Timer registers
5027 b - enable interrupts and start timer
5028 e - stop timer and disable interrupts
5029 q - quit application
5032 ## Ready for S-Record download ...
5033 ~>examples/timer.srec
5034 1 2 3 4 5 6 7 8 9 10 11 ...
5035 [file transfer complete]
5037 ## Start Addr = 0x00040004
5040 ## Starting application at 0x00040004 ...
5043 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5046 [q, b, e, ?] Set interval 1000000 us
5049 [q, b, e, ?] ........
5050 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5053 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5056 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5059 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5061 [q, b, e, ?] ...Stopping timer
5063 [q, b, e, ?] ## Application terminated, rc = 0x0
5069 Over time, many people have reported problems when trying to use the
5070 "minicom" terminal emulation program for serial download. I (wd)
5071 consider minicom to be broken, and recommend not to use it. Under
5072 Unix, I recommend to use C-Kermit for general purpose use (and
5073 especially for kermit binary protocol download ("loadb" command), and
5074 use "cu" for S-Record download ("loads" command). See
5075 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5076 for help with kermit.
5079 Nevertheless, if you absolutely want to use it try adding this
5080 configuration to your "File transfer protocols" section:
5082 Name Program Name U/D FullScr IO-Red. Multi
5083 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5084 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5090 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5091 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5093 Building requires a cross environment; it is known to work on
5094 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5095 need gmake since the Makefiles are not compatible with BSD make).
5096 Note that the cross-powerpc package does not install include files;
5097 attempting to build U-Boot will fail because <machine/ansi.h> is
5098 missing. This file has to be installed and patched manually:
5100 # cd /usr/pkg/cross/powerpc-netbsd/include
5102 # ln -s powerpc machine
5103 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5104 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5106 Native builds *don't* work due to incompatibilities between native
5107 and U-Boot include files.
5109 Booting assumes that (the first part of) the image booted is a
5110 stage-2 loader which in turn loads and then invokes the kernel
5111 proper. Loader sources will eventually appear in the NetBSD source
5112 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5113 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5116 Implementation Internals:
5117 =========================
5119 The following is not intended to be a complete description of every
5120 implementation detail. However, it should help to understand the
5121 inner workings of U-Boot and make it easier to port it to custom
5125 Initial Stack, Global Data:
5126 ---------------------------
5128 The implementation of U-Boot is complicated by the fact that U-Boot
5129 starts running out of ROM (flash memory), usually without access to
5130 system RAM (because the memory controller is not initialized yet).
5131 This means that we don't have writable Data or BSS segments, and BSS
5132 is not initialized as zero. To be able to get a C environment working
5133 at all, we have to allocate at least a minimal stack. Implementation
5134 options for this are defined and restricted by the CPU used: Some CPU
5135 models provide on-chip memory (like the IMMR area on MPC8xx and
5136 MPC826x processors), on others (parts of) the data cache can be
5137 locked as (mis-) used as memory, etc.
5139 Chris Hallinan posted a good summary of these issues to the
5140 U-Boot mailing list:
5142 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5144 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5147 Correct me if I'm wrong, folks, but the way I understand it
5148 is this: Using DCACHE as initial RAM for Stack, etc, does not
5149 require any physical RAM backing up the cache. The cleverness
5150 is that the cache is being used as a temporary supply of
5151 necessary storage before the SDRAM controller is setup. It's
5152 beyond the scope of this list to explain the details, but you
5153 can see how this works by studying the cache architecture and
5154 operation in the architecture and processor-specific manuals.
5156 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5157 is another option for the system designer to use as an
5158 initial stack/RAM area prior to SDRAM being available. Either
5159 option should work for you. Using CS 4 should be fine if your
5160 board designers haven't used it for something that would
5161 cause you grief during the initial boot! It is frequently not
5164 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5165 with your processor/board/system design. The default value
5166 you will find in any recent u-boot distribution in
5167 walnut.h should work for you. I'd set it to a value larger
5168 than your SDRAM module. If you have a 64MB SDRAM module, set
5169 it above 400_0000. Just make sure your board has no resources
5170 that are supposed to respond to that address! That code in
5171 start.S has been around a while and should work as is when
5172 you get the config right.
5177 It is essential to remember this, since it has some impact on the C
5178 code for the initialization procedures:
5180 * Initialized global data (data segment) is read-only. Do not attempt
5183 * Do not use any uninitialized global data (or implicitly initialized
5184 as zero data - BSS segment) at all - this is undefined, initiali-
5185 zation is performed later (when relocating to RAM).
5187 * Stack space is very limited. Avoid big data buffers or things like
5190 Having only the stack as writable memory limits means we cannot use
5191 normal global data to share information between the code. But it
5192 turned out that the implementation of U-Boot can be greatly
5193 simplified by making a global data structure (gd_t) available to all
5194 functions. We could pass a pointer to this data as argument to _all_
5195 functions, but this would bloat the code. Instead we use a feature of
5196 the GCC compiler (Global Register Variables) to share the data: we
5197 place a pointer (gd) to the global data into a register which we
5198 reserve for this purpose.
5200 When choosing a register for such a purpose we are restricted by the
5201 relevant (E)ABI specifications for the current architecture, and by
5202 GCC's implementation.
5204 For PowerPC, the following registers have specific use:
5206 R2: reserved for system use
5207 R3-R4: parameter passing and return values
5208 R5-R10: parameter passing
5209 R13: small data area pointer
5213 (U-Boot also uses R12 as internal GOT pointer. r12
5214 is a volatile register so r12 needs to be reset when
5215 going back and forth between asm and C)
5217 ==> U-Boot will use R2 to hold a pointer to the global data
5219 Note: on PPC, we could use a static initializer (since the
5220 address of the global data structure is known at compile time),
5221 but it turned out that reserving a register results in somewhat
5222 smaller code - although the code savings are not that big (on
5223 average for all boards 752 bytes for the whole U-Boot image,
5224 624 text + 127 data).
5226 On ARM, the following registers are used:
5228 R0: function argument word/integer result
5229 R1-R3: function argument word
5230 R9: platform specific
5231 R10: stack limit (used only if stack checking is enabled)
5232 R11: argument (frame) pointer
5233 R12: temporary workspace
5236 R15: program counter
5238 ==> U-Boot will use R9 to hold a pointer to the global data
5240 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5242 On Nios II, the ABI is documented here:
5243 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5245 ==> U-Boot will use gp to hold a pointer to the global data
5247 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5248 to access small data sections, so gp is free.
5250 On NDS32, the following registers are used:
5252 R0-R1: argument/return
5254 R15: temporary register for assembler
5255 R16: trampoline register
5256 R28: frame pointer (FP)
5257 R29: global pointer (GP)
5258 R30: link register (LP)
5259 R31: stack pointer (SP)
5260 PC: program counter (PC)
5262 ==> U-Boot will use R10 to hold a pointer to the global data
5264 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5265 or current versions of GCC may "optimize" the code too much.
5270 U-Boot runs in system state and uses physical addresses, i.e. the
5271 MMU is not used either for address mapping nor for memory protection.
5273 The available memory is mapped to fixed addresses using the memory
5274 controller. In this process, a contiguous block is formed for each
5275 memory type (Flash, SDRAM, SRAM), even when it consists of several
5276 physical memory banks.
5278 U-Boot is installed in the first 128 kB of the first Flash bank (on
5279 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5280 booting and sizing and initializing DRAM, the code relocates itself
5281 to the upper end of DRAM. Immediately below the U-Boot code some
5282 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5283 configuration setting]. Below that, a structure with global Board
5284 Info data is placed, followed by the stack (growing downward).
5286 Additionally, some exception handler code is copied to the low 8 kB
5287 of DRAM (0x00000000 ... 0x00001FFF).
5289 So a typical memory configuration with 16 MB of DRAM could look like
5292 0x0000 0000 Exception Vector code
5295 0x0000 2000 Free for Application Use
5301 0x00FB FF20 Monitor Stack (Growing downward)
5302 0x00FB FFAC Board Info Data and permanent copy of global data
5303 0x00FC 0000 Malloc Arena
5306 0x00FE 0000 RAM Copy of Monitor Code
5307 ... eventually: LCD or video framebuffer
5308 ... eventually: pRAM (Protected RAM - unchanged by reset)
5309 0x00FF FFFF [End of RAM]
5312 System Initialization:
5313 ----------------------
5315 In the reset configuration, U-Boot starts at the reset entry point
5316 (on most PowerPC systems at address 0x00000100). Because of the reset
5317 configuration for CS0# this is a mirror of the on board Flash memory.
5318 To be able to re-map memory U-Boot then jumps to its link address.
5319 To be able to implement the initialization code in C, a (small!)
5320 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5321 which provide such a feature like), or in a locked part of the data
5322 cache. After that, U-Boot initializes the CPU core, the caches and
5325 Next, all (potentially) available memory banks are mapped using a
5326 preliminary mapping. For example, we put them on 512 MB boundaries
5327 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5328 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5329 programmed for SDRAM access. Using the temporary configuration, a
5330 simple memory test is run that determines the size of the SDRAM
5333 When there is more than one SDRAM bank, and the banks are of
5334 different size, the largest is mapped first. For equal size, the first
5335 bank (CS2#) is mapped first. The first mapping is always for address
5336 0x00000000, with any additional banks following immediately to create
5337 contiguous memory starting from 0.
5339 Then, the monitor installs itself at the upper end of the SDRAM area
5340 and allocates memory for use by malloc() and for the global Board
5341 Info data; also, the exception vector code is copied to the low RAM
5342 pages, and the final stack is set up.
5344 Only after this relocation will you have a "normal" C environment;
5345 until that you are restricted in several ways, mostly because you are
5346 running from ROM, and because the code will have to be relocated to a
5350 U-Boot Porting Guide:
5351 ----------------------
5353 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5357 int main(int argc, char *argv[])
5359 sighandler_t no_more_time;
5361 signal(SIGALRM, no_more_time);
5362 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5364 if (available_money > available_manpower) {
5365 Pay consultant to port U-Boot;
5369 Download latest U-Boot source;
5371 Subscribe to u-boot mailing list;
5374 email("Hi, I am new to U-Boot, how do I get started?");
5377 Read the README file in the top level directory;
5378 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5379 Read applicable doc/*.README;
5380 Read the source, Luke;
5381 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5384 if (available_money > toLocalCurrency ($2500))
5387 Add a lot of aggravation and time;
5389 if (a similar board exists) { /* hopefully... */
5390 cp -a board/<similar> board/<myboard>
5391 cp include/configs/<similar>.h include/configs/<myboard>.h
5393 Create your own board support subdirectory;
5394 Create your own board include/configs/<myboard>.h file;
5396 Edit new board/<myboard> files
5397 Edit new include/configs/<myboard>.h
5402 Add / modify source code;
5406 email("Hi, I am having problems...");
5408 Send patch file to the U-Boot email list;
5409 if (reasonable critiques)
5410 Incorporate improvements from email list code review;
5412 Defend code as written;
5418 void no_more_time (int sig)
5427 All contributions to U-Boot should conform to the Linux kernel
5428 coding style; see the file "Documentation/CodingStyle" and the script
5429 "scripts/Lindent" in your Linux kernel source directory.
5431 Source files originating from a different project (for example the
5432 MTD subsystem) are generally exempt from these guidelines and are not
5433 reformatted to ease subsequent migration to newer versions of those
5436 Please note that U-Boot is implemented in C (and to some small parts in
5437 Assembler); no C++ is used, so please do not use C++ style comments (//)
5440 Please also stick to the following formatting rules:
5441 - remove any trailing white space
5442 - use TAB characters for indentation and vertical alignment, not spaces
5443 - make sure NOT to use DOS '\r\n' line feeds
5444 - do not add more than 2 consecutive empty lines to source files
5445 - do not add trailing empty lines to source files
5447 Submissions which do not conform to the standards may be returned
5448 with a request to reformat the changes.
5454 Since the number of patches for U-Boot is growing, we need to
5455 establish some rules. Submissions which do not conform to these rules
5456 may be rejected, even when they contain important and valuable stuff.
5458 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5461 see http://lists.denx.de/mailman/listinfo/u-boot
5463 When you send a patch, please include the following information with
5466 * For bug fixes: a description of the bug and how your patch fixes
5467 this bug. Please try to include a way of demonstrating that the
5468 patch actually fixes something.
5470 * For new features: a description of the feature and your
5473 * A CHANGELOG entry as plaintext (separate from the patch)
5475 * For major contributions, add a MAINTAINERS file with your
5476 information and associated file and directory references.
5478 * When you add support for a new board, don't forget to add a
5479 maintainer e-mail address to the boards.cfg file, too.
5481 * If your patch adds new configuration options, don't forget to
5482 document these in the README file.
5484 * The patch itself. If you are using git (which is *strongly*
5485 recommended) you can easily generate the patch using the
5486 "git format-patch". If you then use "git send-email" to send it to
5487 the U-Boot mailing list, you will avoid most of the common problems
5488 with some other mail clients.
5490 If you cannot use git, use "diff -purN OLD NEW". If your version of
5491 diff does not support these options, then get the latest version of
5494 The current directory when running this command shall be the parent
5495 directory of the U-Boot source tree (i. e. please make sure that
5496 your patch includes sufficient directory information for the
5499 We prefer patches as plain text. MIME attachments are discouraged,
5500 and compressed attachments must not be used.
5502 * If one logical set of modifications affects or creates several
5503 files, all these changes shall be submitted in a SINGLE patch file.
5505 * Changesets that contain different, unrelated modifications shall be
5506 submitted as SEPARATE patches, one patch per changeset.
5511 * Before sending the patch, run the buildman script on your patched
5512 source tree and make sure that no errors or warnings are reported
5513 for any of the boards.
5515 * Keep your modifications to the necessary minimum: A patch
5516 containing several unrelated changes or arbitrary reformats will be
5517 returned with a request to re-formatting / split it.
5519 * If you modify existing code, make sure that your new code does not
5520 add to the memory footprint of the code ;-) Small is beautiful!
5521 When adding new features, these should compile conditionally only
5522 (using #ifdef), and the resulting code with the new feature
5523 disabled must not need more memory than the old code without your
5526 * Remember that there is a size limit of 100 kB per message on the
5527 u-boot mailing list. Bigger patches will be moderated. If they are
5528 reasonable and not too big, they will be acknowledged. But patches
5529 bigger than the size limit should be avoided.
projects / J-u-boot.git / blob