2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG file to find out who contributed
38 the specific port. In addition, there are various MAINTAINERS files
39 scattered throughout the U-Boot source identifying the people or
40 companies responsible for various boards and subsystems.
42 Note: As of August, 2010, there is no longer a CHANGELOG file in the
43 actual U-Boot source tree; however, it can be created dynamically
44 from the Git log using:
52 In case you have questions about, problems with or contributions for
53 U-Boot, you should send a message to the U-Boot mailing list at
54 <u-boot@lists.denx.de>. There is also an archive of previous traffic
55 on the mailing list - please search the archive before asking FAQ's.
56 Please see http://lists.denx.de/pipermail/u-boot and
57 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
60 Where to get source code:
61 =========================
63 The U-Boot source code is maintained in the Git repository at
64 git://www.denx.de/git/u-boot.git ; you can browse it online at
65 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
67 The "snapshot" links on this page allow you to download tarballs of
68 any version you might be interested in. Official releases are also
69 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
72 Pre-built (and tested) images are available from
73 ftp://ftp.denx.de/pub/u-boot/images/
79 - start from 8xxrom sources
80 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
82 - make it easier to add custom boards
83 - make it possible to add other [PowerPC] CPUs
84 - extend functions, especially:
85 * Provide extended interface to Linux boot loader
88 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
89 - create ARMBoot project (http://sourceforge.net/projects/armboot)
90 - add other CPU families (starting with ARM)
91 - create U-Boot project (http://sourceforge.net/projects/u-boot)
92 - current project page: see http://www.denx.de/wiki/U-Boot
98 The "official" name of this project is "Das U-Boot". The spelling
99 "U-Boot" shall be used in all written text (documentation, comments
100 in source files etc.). Example:
102 This is the README file for the U-Boot project.
104 File names etc. shall be based on the string "u-boot". Examples:
106 include/asm-ppc/u-boot.h
108 #include <asm/u-boot.h>
110 Variable names, preprocessor constants etc. shall be either based on
111 the string "u_boot" or on "U_BOOT". Example:
113 U_BOOT_VERSION u_boot_logo
114 IH_OS_U_BOOT u_boot_hush_start
120 Starting with the release in October 2008, the names of the releases
121 were changed from numerical release numbers without deeper meaning
122 into a time stamp based numbering. Regular releases are identified by
123 names consisting of the calendar year and month of the release date.
124 Additional fields (if present) indicate release candidates or bug fix
125 releases in "stable" maintenance trees.
128 U-Boot v2009.11 - Release November 2009
129 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
130 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
136 /arch Architecture specific files
137 /arc Files generic to ARC architecture
138 /arm Files generic to ARM architecture
139 /avr32 Files generic to AVR32 architecture
140 /blackfin Files generic to Analog Devices Blackfin architecture
141 /m68k Files generic to m68k architecture
142 /microblaze Files generic to microblaze architecture
143 /mips Files generic to MIPS architecture
144 /nds32 Files generic to NDS32 architecture
145 /nios2 Files generic to Altera NIOS2 architecture
146 /openrisc Files generic to OpenRISC architecture
147 /powerpc Files generic to PowerPC architecture
148 /sandbox Files generic to HW-independent "sandbox"
149 /sh Files generic to SH architecture
150 /sparc Files generic to SPARC architecture
151 /x86 Files generic to x86 architecture
152 /api Machine/arch independent API for external apps
153 /board Board dependent files
154 /cmd U-Boot commands functions
155 /common Misc architecture independent functions
156 /configs Board default configuration files
157 /disk Code for disk drive partition handling
158 /doc Documentation (don't expect too much)
159 /drivers Commonly used device drivers
160 /dts Contains Makefile for building internal U-Boot fdt.
161 /examples Example code for standalone applications, etc.
162 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
163 /include Header Files
164 /lib Library routines generic to all architectures
165 /Licenses Various license files
167 /post Power On Self Test
168 /scripts Various build scripts and Makefiles
169 /test Various unit test files
170 /tools Tools to build S-Record or U-Boot images, etc.
172 Software Configuration:
173 =======================
175 Configuration is usually done using C preprocessor defines; the
176 rationale behind that is to avoid dead code whenever possible.
178 There are two classes of configuration variables:
180 * Configuration _OPTIONS_:
181 These are selectable by the user and have names beginning with
184 * Configuration _SETTINGS_:
185 These depend on the hardware etc. and should not be meddled with if
186 you don't know what you're doing; they have names beginning with
189 Previously, all configuration was done by hand, which involved creating
190 symbolic links and editing configuration files manually. More recently,
191 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
192 allowing you to use the "make menuconfig" command to configure your
196 Selection of Processor Architecture and Board Type:
197 ---------------------------------------------------
199 For all supported boards there are ready-to-use default
200 configurations available; just type "make <board_name>_defconfig".
202 Example: For a TQM823L module type:
205 make TQM823L_defconfig
207 Note: If you're looking for the default configuration file for a board
208 you're sure used to be there but is now missing, check the file
209 doc/README.scrapyard for a list of no longer supported boards.
214 U-Boot can be built natively to run on a Linux host using the 'sandbox'
215 board. This allows feature development which is not board- or architecture-
216 specific to be undertaken on a native platform. The sandbox is also used to
217 run some of U-Boot's tests.
219 See board/sandbox/README.sandbox for more details.
222 Board Initialisation Flow:
223 --------------------------
225 This is the intended start-up flow for boards. This should apply for both
226 SPL and U-Boot proper (i.e. they both follow the same rules).
228 Note: "SPL" stands for "Secondary Program Loader," which is explained in
229 more detail later in this file.
231 At present, SPL mostly uses a separate code path, but the function names
232 and roles of each function are the same. Some boards or architectures
233 may not conform to this. At least most ARM boards which use
234 CONFIG_SPL_FRAMEWORK conform to this.
236 Execution typically starts with an architecture-specific (and possibly
237 CPU-specific) start.S file, such as:
239 - arch/arm/cpu/armv7/start.S
240 - arch/powerpc/cpu/mpc83xx/start.S
241 - arch/mips/cpu/start.S
243 and so on. From there, three functions are called; the purpose and
244 limitations of each of these functions are described below.
247 - purpose: essential init to permit execution to reach board_init_f()
248 - no global_data or BSS
249 - there is no stack (ARMv7 may have one but it will soon be removed)
250 - must not set up SDRAM or use console
251 - must only do the bare minimum to allow execution to continue to
253 - this is almost never needed
254 - return normally from this function
257 - purpose: set up the machine ready for running board_init_r():
258 i.e. SDRAM and serial UART
259 - global_data is available
261 - BSS is not available, so you cannot use global/static variables,
262 only stack variables and global_data
264 Non-SPL-specific notes:
265 - dram_init() is called to set up DRAM. If already done in SPL this
269 - you can override the entire board_init_f() function with your own
271 - preloader_console_init() can be called here in extremis
272 - should set up SDRAM, and anything needed to make the UART work
273 - these is no need to clear BSS, it will be done by crt0.S
274 - must return normally from this function (don't call board_init_r()
277 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
278 this point the stack and global_data are relocated to below
279 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
283 - purpose: main execution, common code
284 - global_data is available
286 - BSS is available, all static/global variables can be used
287 - execution eventually continues to main_loop()
289 Non-SPL-specific notes:
290 - U-Boot is relocated to the top of memory and is now running from
294 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
295 CONFIG_SPL_STACK_R_ADDR points into SDRAM
296 - preloader_console_init() can be called here - typically this is
297 done by defining CONFIG_SPL_BOARD_INIT and then supplying a
298 spl_board_init() function containing this call
299 - loads U-Boot or (in falcon mode) Linux
303 Configuration Options:
304 ----------------------
306 Configuration depends on the combination of board and CPU type; all
307 such information is kept in a configuration file
308 "include/configs/<board_name>.h".
310 Example: For a TQM823L module, all configuration settings are in
311 "include/configs/TQM823L.h".
314 Many of the options are named exactly as the corresponding Linux
315 kernel configuration options. The intention is to make it easier to
316 build a config tool - later.
319 The following options need to be configured:
321 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
323 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
325 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
326 Define exactly one, e.g. CONFIG_ATSTK1002
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
333 - 8xx CPU Options: (if using an MPC8xx CPU)
334 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
335 get_gclk_freq() cannot work
336 e.g. if there is no 32KHz
337 reference PIT/RTC clock
338 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
341 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
342 CONFIG_SYS_8xx_CPUCLK_MIN
343 CONFIG_SYS_8xx_CPUCLK_MAX
344 CONFIG_8xx_CPUCLK_DEFAULT
345 See doc/README.MPC866
347 CONFIG_SYS_MEASURE_CPUCLK
349 Define this to measure the actual CPU clock instead
350 of relying on the correctness of the configured
351 values. Mostly useful for board bringup to make sure
352 the PLL is locked at the intended frequency. Note
353 that this requires a (stable) reference clock (32 kHz
354 RTC clock or CONFIG_SYS_8XX_XIN)
356 CONFIG_SYS_DELAYED_ICACHE
358 Define this option if you want to enable the
359 ICache only when Code runs from RAM.
364 Specifies that the core is a 64-bit PowerPC implementation (implements
365 the "64" category of the Power ISA). This is necessary for ePAPR
366 compliance, among other possible reasons.
368 CONFIG_SYS_FSL_TBCLK_DIV
370 Defines the core time base clock divider ratio compared to the
371 system clock. On most PQ3 devices this is 8, on newer QorIQ
372 devices it can be 16 or 32. The ratio varies from SoC to Soc.
374 CONFIG_SYS_FSL_PCIE_COMPAT
376 Defines the string to utilize when trying to match PCIe device
377 tree nodes for the given platform.
379 CONFIG_SYS_PPC_E500_DEBUG_TLB
381 Enables a temporary TLB entry to be used during boot to work
382 around limitations in e500v1 and e500v2 external debugger
383 support. This reduces the portions of the boot code where
384 breakpoints and single stepping do not work. The value of this
385 symbol should be set to the TLB1 entry to be used for this
388 CONFIG_SYS_FSL_ERRATUM_A004510
390 Enables a workaround for erratum A004510. If set,
391 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
392 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
394 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
395 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
397 Defines one or two SoC revisions (low 8 bits of SVR)
398 for which the A004510 workaround should be applied.
400 The rest of SVR is either not relevant to the decision
401 of whether the erratum is present (e.g. p2040 versus
402 p2041) or is implied by the build target, which controls
403 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
405 See Freescale App Note 4493 for more information about
408 CONFIG_A003399_NOR_WORKAROUND
409 Enables a workaround for IFC erratum A003399. It is only
410 required during NOR boot.
412 CONFIG_A008044_WORKAROUND
413 Enables a workaround for T1040/T1042 erratum A008044. It is only
414 required during NAND boot and valid for Rev 1.0 SoC revision
416 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
418 This is the value to write into CCSR offset 0x18600
419 according to the A004510 workaround.
421 CONFIG_SYS_FSL_DSP_DDR_ADDR
422 This value denotes start offset of DDR memory which is
423 connected exclusively to the DSP cores.
425 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
426 This value denotes start offset of M2 memory
427 which is directly connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
430 This value denotes start offset of M3 memory which is directly
431 connected to the DSP core.
433 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
434 This value denotes start offset of DSP CCSR space.
436 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
437 Single Source Clock is clocking mode present in some of FSL SoC's.
438 In this mode, a single differential clock is used to supply
439 clocks to the sysclock, ddrclock and usbclock.
441 CONFIG_SYS_CPC_REINIT_F
442 This CONFIG is defined when the CPC is configured as SRAM at the
443 time of U-Boot entry and is required to be re-initialized.
446 Indicates this SoC supports deep sleep feature. If deep sleep is
447 supported, core will start to execute uboot when wakes up.
449 - Generic CPU options:
450 CONFIG_SYS_GENERIC_GLOBAL_DATA
451 Defines global data is initialized in generic board board_init_f().
452 If this macro is defined, global data is created and cleared in
453 generic board board_init_f(). Without this macro, architecture/board
454 should initialize global data before calling board_init_f().
456 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
458 Defines the endianess of the CPU. Implementation of those
459 values is arch specific.
462 Freescale DDR driver in use. This type of DDR controller is
463 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
466 CONFIG_SYS_FSL_DDR_ADDR
467 Freescale DDR memory-mapped register base.
469 CONFIG_SYS_FSL_DDR_EMU
470 Specify emulator support for DDR. Some DDR features such as
471 deskew training are not available.
473 CONFIG_SYS_FSL_DDRC_GEN1
474 Freescale DDR1 controller.
476 CONFIG_SYS_FSL_DDRC_GEN2
477 Freescale DDR2 controller.
479 CONFIG_SYS_FSL_DDRC_GEN3
480 Freescale DDR3 controller.
482 CONFIG_SYS_FSL_DDRC_GEN4
483 Freescale DDR4 controller.
485 CONFIG_SYS_FSL_DDRC_ARM_GEN3
486 Freescale DDR3 controller for ARM-based SoCs.
489 Board config to use DDR1. It can be enabled for SoCs with
490 Freescale DDR1 or DDR2 controllers, depending on the board
494 Board config to use DDR2. It can be enabled for SoCs with
495 Freescale DDR2 or DDR3 controllers, depending on the board
499 Board config to use DDR3. It can be enabled for SoCs with
500 Freescale DDR3 or DDR3L controllers.
503 Board config to use DDR3L. It can be enabled for SoCs with
507 Board config to use DDR4. It can be enabled for SoCs with
510 CONFIG_SYS_FSL_IFC_BE
511 Defines the IFC controller register space as Big Endian
513 CONFIG_SYS_FSL_IFC_LE
514 Defines the IFC controller register space as Little Endian
516 CONFIG_SYS_FSL_PBL_PBI
517 It enables addition of RCW (Power on reset configuration) in built image.
518 Please refer doc/README.pblimage for more details
520 CONFIG_SYS_FSL_PBL_RCW
521 It adds PBI(pre-boot instructions) commands in u-boot build image.
522 PBI commands can be used to configure SoC before it starts the execution.
523 Please refer doc/README.pblimage for more details
526 It adds a target to create boot binary having SPL binary in PBI format
527 concatenated with u-boot binary.
529 CONFIG_SYS_FSL_DDR_BE
530 Defines the DDR controller register space as Big Endian
532 CONFIG_SYS_FSL_DDR_LE
533 Defines the DDR controller register space as Little Endian
535 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
536 Physical address from the view of DDR controllers. It is the
537 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
538 it could be different for ARM SoCs.
540 CONFIG_SYS_FSL_DDR_INTLV_256B
541 DDR controller interleaving on 256-byte. This is a special
542 interleaving mode, handled by Dickens for Freescale layerscape
545 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
546 Number of controllers used as main memory.
548 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
549 Number of controllers used for other than main memory.
551 CONFIG_SYS_FSL_HAS_DP_DDR
552 Defines the SoC has DP-DDR used for DPAA.
554 CONFIG_SYS_FSL_SEC_BE
555 Defines the SEC controller register space as Big Endian
557 CONFIG_SYS_FSL_SEC_LE
558 Defines the SEC controller register space as Little Endian
561 CONFIG_SYS_INIT_SP_OFFSET
563 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
564 pointer. This is needed for the temporary stack before
567 CONFIG_SYS_MIPS_CACHE_MODE
569 Cache operation mode for the MIPS CPU.
570 See also arch/mips/include/asm/mipsregs.h.
572 CONF_CM_CACHABLE_NO_WA
575 CONF_CM_CACHABLE_NONCOHERENT
579 CONF_CM_CACHABLE_ACCELERATED
581 CONFIG_SYS_XWAY_EBU_BOOTCFG
583 Special option for Lantiq XWAY SoCs for booting from NOR flash.
584 See also arch/mips/cpu/mips32/start.S.
586 CONFIG_XWAY_SWAP_BYTES
588 Enable compilation of tools/xway-swap-bytes needed for Lantiq
589 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
590 be swapped if a flash programmer is used.
593 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
595 Select high exception vectors of the ARM core, e.g., do not
596 clear the V bit of the c1 register of CP15.
598 CONFIG_SYS_THUMB_BUILD
600 Use this flag to build U-Boot using the Thumb instruction
601 set for ARM architectures. Thumb instruction set provides
602 better code density. For ARM architectures that support
603 Thumb2 this flag will result in Thumb2 code generated by
606 CONFIG_ARM_ERRATA_716044
607 CONFIG_ARM_ERRATA_742230
608 CONFIG_ARM_ERRATA_743622
609 CONFIG_ARM_ERRATA_751472
610 CONFIG_ARM_ERRATA_761320
611 CONFIG_ARM_ERRATA_773022
612 CONFIG_ARM_ERRATA_774769
613 CONFIG_ARM_ERRATA_794072
615 If set, the workarounds for these ARM errata are applied early
616 during U-Boot startup. Note that these options force the
617 workarounds to be applied; no CPU-type/version detection
618 exists, unlike the similar options in the Linux kernel. Do not
619 set these options unless they apply!
622 Generic timer clock source frequency.
624 COUNTER_FREQUENCY_REAL
625 Generic timer clock source frequency if the real clock is
626 different from COUNTER_FREQUENCY, and can only be determined
629 NOTE: The following can be machine specific errata. These
630 do have ability to provide rudimentary version and machine
631 specific checks, but expect no product checks.
632 CONFIG_ARM_ERRATA_430973
633 CONFIG_ARM_ERRATA_454179
634 CONFIG_ARM_ERRATA_621766
635 CONFIG_ARM_ERRATA_798870
636 CONFIG_ARM_ERRATA_801819
639 CONFIG_TEGRA_SUPPORT_NON_SECURE
641 Support executing U-Boot in non-secure (NS) mode. Certain
642 impossible actions will be skipped if the CPU is in NS mode,
643 such as ARM architectural timer initialization.
645 - Linux Kernel Interface:
648 U-Boot stores all clock information in Hz
649 internally. For binary compatibility with older Linux
650 kernels (which expect the clocks passed in the
651 bd_info data to be in MHz) the environment variable
652 "clocks_in_mhz" can be defined so that U-Boot
653 converts clock data to MHZ before passing it to the
655 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
656 "clocks_in_mhz=1" is automatically included in the
659 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
661 When transferring memsize parameter to Linux, some versions
662 expect it to be in bytes, others in MB.
663 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
667 New kernel versions are expecting firmware settings to be
668 passed using flattened device trees (based on open firmware
672 * New libfdt-based support
673 * Adds the "fdt" command
674 * The bootm command automatically updates the fdt
676 OF_CPU - The proper name of the cpus node (only required for
677 MPC512X and MPC5xxx based boards).
678 OF_SOC - The proper name of the soc node (only required for
679 MPC512X and MPC5xxx based boards).
680 OF_TBCLK - The timebase frequency.
681 OF_STDOUT_PATH - The path to the console device
683 boards with QUICC Engines require OF_QE to set UCC MAC
686 CONFIG_OF_BOARD_SETUP
688 Board code has addition modification that it wants to make
689 to the flat device tree before handing it off to the kernel
691 CONFIG_OF_SYSTEM_SETUP
693 Other code has addition modification that it wants to make
694 to the flat device tree before handing it off to the kernel.
695 This causes ft_system_setup() to be called before booting
700 This define fills in the correct boot CPU in the boot
701 param header, the default value is zero if undefined.
705 U-Boot can detect if an IDE device is present or not.
706 If not, and this new config option is activated, U-Boot
707 removes the ATA node from the DTS before booting Linux,
708 so the Linux IDE driver does not probe the device and
709 crash. This is needed for buggy hardware (uc101) where
710 no pull down resistor is connected to the signal IDE5V_DD7.
712 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
714 This setting is mandatory for all boards that have only one
715 machine type and must be used to specify the machine type
716 number as it appears in the ARM machine registry
717 (see http://www.arm.linux.org.uk/developer/machines/).
718 Only boards that have multiple machine types supported
719 in a single configuration file and the machine type is
720 runtime discoverable, do not have to use this setting.
722 - vxWorks boot parameters:
724 bootvx constructs a valid bootline using the following
725 environments variables: bootdev, bootfile, ipaddr, netmask,
726 serverip, gatewayip, hostname, othbootargs.
727 It loads the vxWorks image pointed bootfile.
729 Note: If a "bootargs" environment is defined, it will overwride
730 the defaults discussed just above.
732 - Cache Configuration:
733 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
734 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
735 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
737 - Cache Configuration for ARM:
738 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
740 CONFIG_SYS_PL310_BASE - Physical base address of PL310
741 controller register space
746 Define this if you want support for Amba PrimeCell PL010 UARTs.
750 Define this if you want support for Amba PrimeCell PL011 UARTs.
754 If you have Amba PrimeCell PL011 UARTs, set this variable to
755 the clock speed of the UARTs.
759 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
760 define this to a list of base addresses for each (supported)
761 port. See e.g. include/configs/versatile.h
763 CONFIG_SERIAL_HW_FLOW_CONTROL
765 Define this variable to enable hw flow control in serial driver.
766 Current user of this option is drivers/serial/nsl16550.c driver
769 Depending on board, define exactly one serial port
770 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
771 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
772 console by defining CONFIG_8xx_CONS_NONE
774 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
775 port routines must be defined elsewhere
776 (i.e. serial_init(), serial_getc(), ...)
779 Enables console device for a color framebuffer. Needs following
780 defines (cf. smiLynxEM, i8042)
781 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
783 VIDEO_HW_RECTFILL graphic chip supports
786 VIDEO_HW_BITBLT graphic chip supports
787 bit-blit (cf. smiLynxEM)
788 VIDEO_VISIBLE_COLS visible pixel columns
790 VIDEO_VISIBLE_ROWS visible pixel rows
791 VIDEO_PIXEL_SIZE bytes per pixel
792 VIDEO_DATA_FORMAT graphic data format
793 (0-5, cf. cfb_console.c)
794 VIDEO_FB_ADRS framebuffer address
795 VIDEO_KBD_INIT_FCT keyboard int fct
796 (i.e. rx51_kp_init())
797 VIDEO_TSTC_FCT test char fct
799 VIDEO_GETC_FCT get char fct
801 CONFIG_VIDEO_LOGO display Linux logo in
803 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
804 linux_logo.h for logo.
805 Requires CONFIG_VIDEO_LOGO
806 CONFIG_CONSOLE_EXTRA_INFO
807 additional board info beside
809 CONFIG_HIDE_LOGO_VERSION
810 do not display bootloader
813 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
814 a limited number of ANSI escape sequences (cursor control,
815 erase functions and limited graphics rendition control).
817 When CONFIG_CFB_CONSOLE is defined, video console is
818 default i/o. Serial console can be forced with
819 environment 'console=serial'.
821 When CONFIG_SILENT_CONSOLE is defined, all console
822 messages (by U-Boot and Linux!) can be silenced with
823 the "silent" environment variable. See
824 doc/README.silent for more information.
826 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
828 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
832 CONFIG_BAUDRATE - in bps
833 Select one of the baudrates listed in
834 CONFIG_SYS_BAUDRATE_TABLE, see below.
835 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
837 - Console Rx buffer length
838 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
839 the maximum receive buffer length for the SMC.
840 This option is actual only for 82xx and 8xx possible.
841 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
842 must be defined, to setup the maximum idle timeout for
845 - Pre-Console Buffer:
846 Prior to the console being initialised (i.e. serial UART
847 initialised etc) all console output is silently discarded.
848 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
849 buffer any console messages prior to the console being
850 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
851 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
852 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
853 bytes are output before the console is initialised, the
854 earlier bytes are discarded.
856 Note that when printing the buffer a copy is made on the
857 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
859 'Sane' compilers will generate smaller code if
860 CONFIG_PRE_CON_BUF_SZ is a power of 2
864 Only needed when CONFIG_BOOTDELAY is enabled;
865 define a command string that is automatically executed
866 when no character is read on the console interface
867 within "Boot Delay" after reset.
870 This can be used to pass arguments to the bootm
871 command. The value of CONFIG_BOOTARGS goes into the
872 environment value "bootargs".
874 CONFIG_RAMBOOT and CONFIG_NFSBOOT
875 The value of these goes into the environment as
876 "ramboot" and "nfsboot" respectively, and can be used
877 as a convenience, when switching between booting from
881 CONFIG_BOOTCOUNT_LIMIT
882 Implements a mechanism for detecting a repeating reboot
884 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
887 If no softreset save registers are found on the hardware
888 "bootcount" is stored in the environment. To prevent a
889 saveenv on all reboots, the environment variable
890 "upgrade_available" is used. If "upgrade_available" is
891 0, "bootcount" is always 0, if "upgrade_available" is
892 1 "bootcount" is incremented in the environment.
893 So the Userspace Applikation must set the "upgrade_available"
894 and "bootcount" variable to 0, if a boot was successfully.
899 When this option is #defined, the existence of the
900 environment variable "preboot" will be checked
901 immediately before starting the CONFIG_BOOTDELAY
902 countdown and/or running the auto-boot command resp.
903 entering interactive mode.
905 This feature is especially useful when "preboot" is
906 automatically generated or modified. For an example
907 see the LWMON board specific code: here "preboot" is
908 modified when the user holds down a certain
909 combination of keys on the (special) keyboard when
912 - Serial Download Echo Mode:
914 If defined to 1, all characters received during a
915 serial download (using the "loads" command) are
916 echoed back. This might be needed by some terminal
917 emulations (like "cu"), but may as well just take
918 time on others. This setting #define's the initial
919 value of the "loads_echo" environment variable.
921 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
923 Select one of the baudrates listed in
924 CONFIG_SYS_BAUDRATE_TABLE, see below.
927 Monitor commands can be included or excluded
928 from the build by using the #include files
929 <config_cmd_all.h> and #undef'ing unwanted
930 commands, or adding #define's for wanted commands.
932 The default command configuration includes all commands
933 except those marked below with a "*".
935 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
936 CONFIG_CMD_ASKENV * ask for env variable
937 CONFIG_CMD_BDI bdinfo
938 CONFIG_CMD_BEDBUG * Include BedBug Debugger
939 CONFIG_CMD_BMP * BMP support
940 CONFIG_CMD_BSP * Board specific commands
941 CONFIG_CMD_BOOTD bootd
942 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
943 CONFIG_CMD_CACHE * icache, dcache
944 CONFIG_CMD_CLK * clock command support
945 CONFIG_CMD_CONSOLE coninfo
946 CONFIG_CMD_CRC32 * crc32
947 CONFIG_CMD_DATE * support for RTC, date/time...
948 CONFIG_CMD_DHCP * DHCP support
949 CONFIG_CMD_DIAG * Diagnostics
950 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
951 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
952 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
953 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
954 CONFIG_CMD_DTT * Digital Therm and Thermostat
955 CONFIG_CMD_ECHO echo arguments
956 CONFIG_CMD_EDITENV edit env variable
957 CONFIG_CMD_EEPROM * EEPROM read/write support
958 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
959 CONFIG_CMD_ELF * bootelf, bootvx
960 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
961 CONFIG_CMD_ENV_FLAGS * display details about env flags
962 CONFIG_CMD_ENV_EXISTS * check existence of env variable
963 CONFIG_CMD_EXPORTENV * export the environment
964 CONFIG_CMD_EXT2 * ext2 command support
965 CONFIG_CMD_EXT4 * ext4 command support
966 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
967 that work for multiple fs types
968 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
969 CONFIG_CMD_SAVEENV saveenv
970 CONFIG_CMD_FDC * Floppy Disk Support
971 CONFIG_CMD_FAT * FAT command support
972 CONFIG_CMD_FLASH flinfo, erase, protect
973 CONFIG_CMD_FPGA FPGA device initialization support
974 CONFIG_CMD_FUSE * Device fuse support
975 CONFIG_CMD_GETTIME * Get time since boot
976 CONFIG_CMD_GO * the 'go' command (exec code)
977 CONFIG_CMD_GREPENV * search environment
978 CONFIG_CMD_HASH * calculate hash / digest
979 CONFIG_CMD_I2C * I2C serial bus support
980 CONFIG_CMD_IDE * IDE harddisk support
981 CONFIG_CMD_IMI iminfo
982 CONFIG_CMD_IMLS List all images found in NOR flash
983 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
984 CONFIG_CMD_IMMAP * IMMR dump support
985 CONFIG_CMD_IOTRACE * I/O tracing for debugging
986 CONFIG_CMD_IMPORTENV * import an environment
987 CONFIG_CMD_INI * import data from an ini file into the env
988 CONFIG_CMD_IRQ * irqinfo
989 CONFIG_CMD_ITEST Integer/string test of 2 values
990 CONFIG_CMD_JFFS2 * JFFS2 Support
991 CONFIG_CMD_KGDB * kgdb
992 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
993 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
995 CONFIG_CMD_LOADB loadb
996 CONFIG_CMD_LOADS loads
997 CONFIG_CMD_MD5SUM * print md5 message digest
998 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
999 CONFIG_CMD_MEMINFO * Display detailed memory information
1000 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1002 CONFIG_CMD_MEMTEST * mtest
1003 CONFIG_CMD_MISC Misc functions like sleep etc
1004 CONFIG_CMD_MMC * MMC memory mapped support
1005 CONFIG_CMD_MII * MII utility commands
1006 CONFIG_CMD_MTDPARTS * MTD partition support
1007 CONFIG_CMD_NAND * NAND support
1008 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1009 CONFIG_CMD_NFS NFS support
1010 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1011 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1012 CONFIG_CMD_PCI * pciinfo
1013 CONFIG_CMD_PCMCIA * PCMCIA support
1014 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1016 CONFIG_CMD_PORTIO * Port I/O
1017 CONFIG_CMD_READ * Read raw data from partition
1018 CONFIG_CMD_REGINFO * Register dump
1019 CONFIG_CMD_RUN run command in env variable
1020 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1021 CONFIG_CMD_SAVES * save S record dump
1022 CONFIG_SCSI * SCSI Support
1023 CONFIG_CMD_SDRAM * print SDRAM configuration information
1024 (requires CONFIG_CMD_I2C)
1025 CONFIG_CMD_SETGETDCR Support for DCR Register access
1027 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1028 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1029 (requires CONFIG_CMD_MEMORY)
1030 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1031 CONFIG_CMD_SOURCE "source" command Support
1032 CONFIG_CMD_SPI * SPI serial bus support
1033 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1034 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1035 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1036 CONFIG_CMD_TIMER * access to the system tick timer
1037 CONFIG_CMD_USB * USB support
1038 CONFIG_CMD_CDP * Cisco Discover Protocol support
1039 CONFIG_CMD_MFSL * Microblaze FSL support
1040 CONFIG_CMD_XIMG Load part of Multi Image
1041 CONFIG_CMD_UUID * Generate random UUID or GUID string
1043 EXAMPLE: If you want all functions except of network
1044 support you can write:
1046 #include "config_cmd_all.h"
1047 #undef CONFIG_CMD_NET
1050 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1052 Note: Don't enable the "icache" and "dcache" commands
1053 (configuration option CONFIG_CMD_CACHE) unless you know
1054 what you (and your U-Boot users) are doing. Data
1055 cache cannot be enabled on systems like the 8xx or
1056 8260 (where accesses to the IMMR region must be
1057 uncached), and it cannot be disabled on all other
1058 systems where we (mis-) use the data cache to hold an
1059 initial stack and some data.
1062 XXX - this list needs to get updated!
1064 - Removal of commands
1065 If no commands are needed to boot, you can disable
1066 CONFIG_CMDLINE to remove them. In this case, the command line
1067 will not be available, and when U-Boot wants to execute the
1068 boot command (on start-up) it will call board_run_command()
1069 instead. This can reduce image size significantly for very
1070 simple boot procedures.
1072 - Regular expression support:
1074 If this variable is defined, U-Boot is linked against
1075 the SLRE (Super Light Regular Expression) library,
1076 which adds regex support to some commands, as for
1077 example "env grep" and "setexpr".
1081 If this variable is defined, U-Boot will use a device tree
1082 to configure its devices, instead of relying on statically
1083 compiled #defines in the board file. This option is
1084 experimental and only available on a few boards. The device
1085 tree is available in the global data as gd->fdt_blob.
1087 U-Boot needs to get its device tree from somewhere. This can
1088 be done using one of the two options below:
1091 If this variable is defined, U-Boot will embed a device tree
1092 binary in its image. This device tree file should be in the
1093 board directory and called <soc>-<board>.dts. The binary file
1094 is then picked up in board_init_f() and made available through
1095 the global data structure as gd->blob.
1098 If this variable is defined, U-Boot will build a device tree
1099 binary. It will be called u-boot.dtb. Architecture-specific
1100 code will locate it at run-time. Generally this works by:
1102 cat u-boot.bin u-boot.dtb >image.bin
1104 and in fact, U-Boot does this for you, creating a file called
1105 u-boot-dtb.bin which is useful in the common case. You can
1106 still use the individual files if you need something more
1111 If this variable is defined, it enables watchdog
1112 support for the SoC. There must be support in the SoC
1113 specific code for a watchdog. For the 8xx and 8260
1114 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1115 register. When supported for a specific SoC is
1116 available, then no further board specific code should
1117 be needed to use it.
1120 When using a watchdog circuitry external to the used
1121 SoC, then define this variable and provide board
1122 specific code for the "hw_watchdog_reset" function.
1124 CONFIG_AT91_HW_WDT_TIMEOUT
1125 specify the timeout in seconds. default 2 seconds.
1128 CONFIG_VERSION_VARIABLE
1129 If this variable is defined, an environment variable
1130 named "ver" is created by U-Boot showing the U-Boot
1131 version as printed by the "version" command.
1132 Any change to this variable will be reverted at the
1137 When CONFIG_CMD_DATE is selected, the type of the RTC
1138 has to be selected, too. Define exactly one of the
1141 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1142 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1143 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1144 CONFIG_RTC_MC146818 - use MC146818 RTC
1145 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1146 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1147 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1148 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1149 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1150 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1151 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1152 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1153 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1156 Note that if the RTC uses I2C, then the I2C interface
1157 must also be configured. See I2C Support, below.
1160 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1162 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1163 chip-ngpio pairs that tell the PCA953X driver the number of
1164 pins supported by a particular chip.
1166 Note that if the GPIO device uses I2C, then the I2C interface
1167 must also be configured. See I2C Support, below.
1170 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1171 accesses and can checksum them or write a list of them out
1172 to memory. See the 'iotrace' command for details. This is
1173 useful for testing device drivers since it can confirm that
1174 the driver behaves the same way before and after a code
1175 change. Currently this is supported on sandbox and arm. To
1176 add support for your architecture, add '#include <iotrace.h>'
1177 to the bottom of arch/<arch>/include/asm/io.h and test.
1179 Example output from the 'iotrace stats' command is below.
1180 Note that if the trace buffer is exhausted, the checksum will
1181 still continue to operate.
1184 Start: 10000000 (buffer start address)
1185 Size: 00010000 (buffer size)
1186 Offset: 00000120 (current buffer offset)
1187 Output: 10000120 (start + offset)
1188 Count: 00000018 (number of trace records)
1189 CRC32: 9526fb66 (CRC32 of all trace records)
1191 - Timestamp Support:
1193 When CONFIG_TIMESTAMP is selected, the timestamp
1194 (date and time) of an image is printed by image
1195 commands like bootm or iminfo. This option is
1196 automatically enabled when you select CONFIG_CMD_DATE .
1198 - Partition Labels (disklabels) Supported:
1199 Zero or more of the following:
1200 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1201 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1202 Intel architecture, USB sticks, etc.
1203 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1204 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1205 bootloader. Note 2TB partition limit; see
1207 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1209 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1210 CONFIG_SCSI) you must configure support for at
1211 least one non-MTD partition type as well.
1214 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1215 board configurations files but used nowhere!
1217 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1218 be performed by calling the function
1219 ide_set_reset(int reset)
1220 which has to be defined in a board specific file
1225 Set this to enable ATAPI support.
1230 Set this to enable support for disks larger than 137GB
1231 Also look at CONFIG_SYS_64BIT_LBA.
1232 Whithout these , LBA48 support uses 32bit variables and will 'only'
1233 support disks up to 2.1TB.
1235 CONFIG_SYS_64BIT_LBA:
1236 When enabled, makes the IDE subsystem use 64bit sector addresses.
1240 At the moment only there is only support for the
1241 SYM53C8XX SCSI controller; define
1242 CONFIG_SCSI_SYM53C8XX to enable it.
1244 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1245 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1246 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1247 maximum numbers of LUNs, SCSI ID's and target
1249 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1251 The environment variable 'scsidevs' is set to the number of
1252 SCSI devices found during the last scan.
1254 - NETWORK Support (PCI):
1256 Support for Intel 8254x/8257x gigabit chips.
1259 Utility code for direct access to the SPI bus on Intel 8257x.
1260 This does not do anything useful unless you set at least one
1261 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1263 CONFIG_E1000_SPI_GENERIC
1264 Allow generic access to the SPI bus on the Intel 8257x, for
1265 example with the "sspi" command.
1268 Management command for E1000 devices. When used on devices
1269 with SPI support you can reprogram the EEPROM from U-Boot.
1272 Support for Intel 82557/82559/82559ER chips.
1273 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1274 write routine for first time initialisation.
1277 Support for Digital 2114x chips.
1278 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1279 modem chip initialisation (KS8761/QS6611).
1282 Support for National dp83815 chips.
1285 Support for National dp8382[01] gigabit chips.
1287 - NETWORK Support (other):
1289 CONFIG_DRIVER_AT91EMAC
1290 Support for AT91RM9200 EMAC.
1293 Define this to use reduced MII inteface
1295 CONFIG_DRIVER_AT91EMAC_QUIET
1296 If this defined, the driver is quiet.
1297 The driver doen't show link status messages.
1299 CONFIG_CALXEDA_XGMAC
1300 Support for the Calxeda XGMAC device
1303 Support for SMSC's LAN91C96 chips.
1305 CONFIG_LAN91C96_BASE
1306 Define this to hold the physical address
1307 of the LAN91C96's I/O space
1309 CONFIG_LAN91C96_USE_32_BIT
1310 Define this to enable 32 bit addressing
1313 Support for SMSC's LAN91C111 chip
1315 CONFIG_SMC91111_BASE
1316 Define this to hold the physical address
1317 of the device (I/O space)
1319 CONFIG_SMC_USE_32_BIT
1320 Define this if data bus is 32 bits
1322 CONFIG_SMC_USE_IOFUNCS
1323 Define this to use i/o functions instead of macros
1324 (some hardware wont work with macros)
1326 CONFIG_DRIVER_TI_EMAC
1327 Support for davinci emac
1329 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1330 Define this if you have more then 3 PHYs.
1333 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1335 CONFIG_FTGMAC100_EGIGA
1336 Define this to use GE link update with gigabit PHY.
1337 Define this if FTGMAC100 is connected to gigabit PHY.
1338 If your system has 10/100 PHY only, it might not occur
1339 wrong behavior. Because PHY usually return timeout or
1340 useless data when polling gigabit status and gigabit
1341 control registers. This behavior won't affect the
1342 correctnessof 10/100 link speed update.
1345 Support for SMSC's LAN911x and LAN921x chips
1348 Define this to hold the physical address
1349 of the device (I/O space)
1351 CONFIG_SMC911X_32_BIT
1352 Define this if data bus is 32 bits
1354 CONFIG_SMC911X_16_BIT
1355 Define this if data bus is 16 bits. If your processor
1356 automatically converts one 32 bit word to two 16 bit
1357 words you may also try CONFIG_SMC911X_32_BIT.
1360 Support for Renesas on-chip Ethernet controller
1362 CONFIG_SH_ETHER_USE_PORT
1363 Define the number of ports to be used
1365 CONFIG_SH_ETHER_PHY_ADDR
1366 Define the ETH PHY's address
1368 CONFIG_SH_ETHER_CACHE_WRITEBACK
1369 If this option is set, the driver enables cache flush.
1373 Support for PWM modul on the imx6.
1377 Support TPM devices.
1379 CONFIG_TPM_TIS_INFINEON
1380 Support for Infineon i2c bus TPM devices. Only one device
1381 per system is supported at this time.
1383 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1384 Define the burst count bytes upper limit
1387 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1389 CONFIG_TPM_ST33ZP24_I2C
1390 Support for STMicroelectronics ST33ZP24 I2C devices.
1391 Requires TPM_ST33ZP24 and I2C.
1393 CONFIG_TPM_ST33ZP24_SPI
1394 Support for STMicroelectronics ST33ZP24 SPI devices.
1395 Requires TPM_ST33ZP24 and SPI.
1397 CONFIG_TPM_ATMEL_TWI
1398 Support for Atmel TWI TPM device. Requires I2C support.
1401 Support for generic parallel port TPM devices. Only one device
1402 per system is supported at this time.
1404 CONFIG_TPM_TIS_BASE_ADDRESS
1405 Base address where the generic TPM device is mapped
1406 to. Contemporary x86 systems usually map it at
1410 Add tpm monitor functions.
1411 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1412 provides monitor access to authorized functions.
1415 Define this to enable the TPM support library which provides
1416 functional interfaces to some TPM commands.
1417 Requires support for a TPM device.
1419 CONFIG_TPM_AUTH_SESSIONS
1420 Define this to enable authorized functions in the TPM library.
1421 Requires CONFIG_TPM and CONFIG_SHA1.
1424 At the moment only the UHCI host controller is
1425 supported (PIP405, MIP405, MPC5200); define
1426 CONFIG_USB_UHCI to enable it.
1427 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1428 and define CONFIG_USB_STORAGE to enable the USB
1431 Supported are USB Keyboards and USB Floppy drives
1433 MPC5200 USB requires additional defines:
1435 for 528 MHz Clock: 0x0001bbbb
1439 for differential drivers: 0x00001000
1440 for single ended drivers: 0x00005000
1441 for differential drivers on PSC3: 0x00000100
1442 for single ended drivers on PSC3: 0x00004100
1443 CONFIG_SYS_USB_EVENT_POLL
1444 May be defined to allow interrupt polling
1445 instead of using asynchronous interrupts
1447 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1448 txfilltuning field in the EHCI controller on reset.
1450 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1451 HW module registers.
1454 Define the below if you wish to use the USB console.
1455 Once firmware is rebuilt from a serial console issue the
1456 command "setenv stdin usbtty; setenv stdout usbtty" and
1457 attach your USB cable. The Unix command "dmesg" should print
1458 it has found a new device. The environment variable usbtty
1459 can be set to gserial or cdc_acm to enable your device to
1460 appear to a USB host as a Linux gserial device or a
1461 Common Device Class Abstract Control Model serial device.
1462 If you select usbtty = gserial you should be able to enumerate
1464 # modprobe usbserial vendor=0xVendorID product=0xProductID
1465 else if using cdc_acm, simply setting the environment
1466 variable usbtty to be cdc_acm should suffice. The following
1467 might be defined in YourBoardName.h
1470 Define this to build a UDC device
1473 Define this to have a tty type of device available to
1474 talk to the UDC device
1477 Define this to enable the high speed support for usb
1478 device and usbtty. If this feature is enabled, a routine
1479 int is_usbd_high_speed(void)
1480 also needs to be defined by the driver to dynamically poll
1481 whether the enumeration has succeded at high speed or full
1484 CONFIG_SYS_CONSOLE_IS_IN_ENV
1485 Define this if you want stdin, stdout &/or stderr to
1489 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1490 Derive USB clock from external clock "blah"
1491 - CONFIG_SYS_USB_EXTC_CLK 0x02
1493 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1494 Derive USB clock from brgclk
1495 - CONFIG_SYS_USB_BRG_CLK 0x04
1497 If you have a USB-IF assigned VendorID then you may wish to
1498 define your own vendor specific values either in BoardName.h
1499 or directly in usbd_vendor_info.h. If you don't define
1500 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1501 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1502 should pretend to be a Linux device to it's target host.
1504 CONFIG_USBD_MANUFACTURER
1505 Define this string as the name of your company for
1506 - CONFIG_USBD_MANUFACTURER "my company"
1508 CONFIG_USBD_PRODUCT_NAME
1509 Define this string as the name of your product
1510 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1512 CONFIG_USBD_VENDORID
1513 Define this as your assigned Vendor ID from the USB
1514 Implementors Forum. This *must* be a genuine Vendor ID
1515 to avoid polluting the USB namespace.
1516 - CONFIG_USBD_VENDORID 0xFFFF
1518 CONFIG_USBD_PRODUCTID
1519 Define this as the unique Product ID
1521 - CONFIG_USBD_PRODUCTID 0xFFFF
1523 - ULPI Layer Support:
1524 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1525 the generic ULPI layer. The generic layer accesses the ULPI PHY
1526 via the platform viewport, so you need both the genric layer and
1527 the viewport enabled. Currently only Chipidea/ARC based
1528 viewport is supported.
1529 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1530 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1531 If your ULPI phy needs a different reference clock than the
1532 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1533 the appropriate value in Hz.
1536 The MMC controller on the Intel PXA is supported. To
1537 enable this define CONFIG_MMC. The MMC can be
1538 accessed from the boot prompt by mapping the device
1539 to physical memory similar to flash. Command line is
1540 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1541 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1544 Support for Renesas on-chip MMCIF controller
1546 CONFIG_SH_MMCIF_ADDR
1547 Define the base address of MMCIF registers
1550 Define the clock frequency for MMCIF
1553 Enable the generic MMC driver
1555 CONFIG_SUPPORT_EMMC_BOOT
1556 Enable some additional features of the eMMC boot partitions.
1558 CONFIG_SUPPORT_EMMC_RPMB
1559 Enable the commands for reading, writing and programming the
1560 key for the Replay Protection Memory Block partition in eMMC.
1562 - USB Device Firmware Update (DFU) class support:
1563 CONFIG_USB_FUNCTION_DFU
1564 This enables the USB portion of the DFU USB class
1567 This enables the command "dfu" which is used to have
1568 U-Boot create a DFU class device via USB. This command
1569 requires that the "dfu_alt_info" environment variable be
1570 set and define the alt settings to expose to the host.
1573 This enables support for exposing (e)MMC devices via DFU.
1576 This enables support for exposing NAND devices via DFU.
1579 This enables support for exposing RAM via DFU.
1580 Note: DFU spec refer to non-volatile memory usage, but
1581 allow usages beyond the scope of spec - here RAM usage,
1582 one that would help mostly the developer.
1584 CONFIG_SYS_DFU_DATA_BUF_SIZE
1585 Dfu transfer uses a buffer before writing data to the
1586 raw storage device. Make the size (in bytes) of this buffer
1587 configurable. The size of this buffer is also configurable
1588 through the "dfu_bufsiz" environment variable.
1590 CONFIG_SYS_DFU_MAX_FILE_SIZE
1591 When updating files rather than the raw storage device,
1592 we use a static buffer to copy the file into and then write
1593 the buffer once we've been given the whole file. Define
1594 this to the maximum filesize (in bytes) for the buffer.
1595 Default is 4 MiB if undefined.
1597 DFU_DEFAULT_POLL_TIMEOUT
1598 Poll timeout [ms], is the timeout a device can send to the
1599 host. The host must wait for this timeout before sending
1600 a subsequent DFU_GET_STATUS request to the device.
1602 DFU_MANIFEST_POLL_TIMEOUT
1603 Poll timeout [ms], which the device sends to the host when
1604 entering dfuMANIFEST state. Host waits this timeout, before
1605 sending again an USB request to the device.
1607 - USB Device Android Fastboot support:
1608 CONFIG_USB_FUNCTION_FASTBOOT
1609 This enables the USB part of the fastboot gadget
1612 This enables the command "fastboot" which enables the Android
1613 fastboot mode for the platform's USB device. Fastboot is a USB
1614 protocol for downloading images, flashing and device control
1615 used on Android devices.
1616 See doc/README.android-fastboot for more information.
1618 CONFIG_ANDROID_BOOT_IMAGE
1619 This enables support for booting images which use the Android
1620 image format header.
1622 CONFIG_FASTBOOT_BUF_ADDR
1623 The fastboot protocol requires a large memory buffer for
1624 downloads. Define this to the starting RAM address to use for
1627 CONFIG_FASTBOOT_BUF_SIZE
1628 The fastboot protocol requires a large memory buffer for
1629 downloads. This buffer should be as large as possible for a
1630 platform. Define this to the size available RAM for fastboot.
1632 CONFIG_FASTBOOT_FLASH
1633 The fastboot protocol includes a "flash" command for writing
1634 the downloaded image to a non-volatile storage device. Define
1635 this to enable the "fastboot flash" command.
1637 CONFIG_FASTBOOT_FLASH_MMC_DEV
1638 The fastboot "flash" command requires additional information
1639 regarding the non-volatile storage device. Define this to
1640 the eMMC device that fastboot should use to store the image.
1642 CONFIG_FASTBOOT_GPT_NAME
1643 The fastboot "flash" command supports writing the downloaded
1644 image to the Protective MBR and the Primary GUID Partition
1645 Table. (Additionally, this downloaded image is post-processed
1646 to generate and write the Backup GUID Partition Table.)
1647 This occurs when the specified "partition name" on the
1648 "fastboot flash" command line matches this value.
1649 The default is "gpt" if undefined.
1651 CONFIG_FASTBOOT_MBR_NAME
1652 The fastboot "flash" command supports writing the downloaded
1654 This occurs when the "partition name" specified on the
1655 "fastboot flash" command line matches this value.
1656 If not defined the default value "mbr" is used.
1658 - Journaling Flash filesystem support:
1659 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1660 CONFIG_JFFS2_NAND_DEV
1661 Define these for a default partition on a NAND device
1663 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1664 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1665 Define these for a default partition on a NOR device
1667 CONFIG_SYS_JFFS_CUSTOM_PART
1668 Define this to create an own partition. You have to provide a
1669 function struct part_info* jffs2_part_info(int part_num)
1671 If you define only one JFFS2 partition you may also want to
1672 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1673 to disable the command chpart. This is the default when you
1674 have not defined a custom partition
1676 - FAT(File Allocation Table) filesystem write function support:
1679 Define this to enable support for saving memory data as a
1680 file in FAT formatted partition.
1682 This will also enable the command "fatwrite" enabling the
1683 user to write files to FAT.
1685 CBFS (Coreboot Filesystem) support
1688 Define this to enable support for reading from a Coreboot
1689 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1692 - FAT(File Allocation Table) filesystem cluster size:
1693 CONFIG_FS_FAT_MAX_CLUSTSIZE
1695 Define the max cluster size for fat operations else
1696 a default value of 65536 will be defined.
1699 See Kconfig help for available keyboard drivers.
1703 Define this to enable a custom keyboard support.
1704 This simply calls drv_keyboard_init() which must be
1705 defined in your board-specific files. This option is deprecated
1706 and is only used by novena. For new boards, use driver model
1712 Define this to enable video support (for output to
1715 CONFIG_VIDEO_CT69000
1717 Enable Chips & Technologies 69000 Video chip
1719 CONFIG_VIDEO_SMI_LYNXEM
1720 Enable Silicon Motion SMI 712/710/810 Video chip. The
1721 video output is selected via environment 'videoout'
1722 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1725 For the CT69000 and SMI_LYNXEM drivers, videomode is
1726 selected via environment 'videomode'. Two different ways
1728 - "videomode=num" 'num' is a standard LiLo mode numbers.
1729 Following standard modes are supported (* is default):
1731 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1732 -------------+---------------------------------------------
1733 8 bits | 0x301* 0x303 0x305 0x161 0x307
1734 15 bits | 0x310 0x313 0x316 0x162 0x319
1735 16 bits | 0x311 0x314 0x317 0x163 0x31A
1736 24 bits | 0x312 0x315 0x318 ? 0x31B
1737 -------------+---------------------------------------------
1738 (i.e. setenv videomode 317; saveenv; reset;)
1740 - "videomode=bootargs" all the video parameters are parsed
1741 from the bootargs. (See drivers/video/videomodes.c)
1744 CONFIG_VIDEO_SED13806
1745 Enable Epson SED13806 driver. This driver supports 8bpp
1746 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1747 or CONFIG_VIDEO_SED13806_16BPP
1750 Enable the Freescale DIU video driver. Reference boards for
1751 SOCs that have a DIU should define this macro to enable DIU
1752 support, and should also define these other macros:
1758 CONFIG_VIDEO_SW_CURSOR
1759 CONFIG_VGA_AS_SINGLE_DEVICE
1761 CONFIG_VIDEO_BMP_LOGO
1763 The DIU driver will look for the 'video-mode' environment
1764 variable, and if defined, enable the DIU as a console during
1765 boot. See the documentation file doc/README.video for a
1766 description of this variable.
1768 - LCD Support: CONFIG_LCD
1770 Define this to enable LCD support (for output to LCD
1771 display); also select one of the supported displays
1772 by defining one of these:
1776 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1778 CONFIG_NEC_NL6448AC33:
1780 NEC NL6448AC33-18. Active, color, single scan.
1782 CONFIG_NEC_NL6448BC20
1784 NEC NL6448BC20-08. 6.5", 640x480.
1785 Active, color, single scan.
1787 CONFIG_NEC_NL6448BC33_54
1789 NEC NL6448BC33-54. 10.4", 640x480.
1790 Active, color, single scan.
1794 Sharp 320x240. Active, color, single scan.
1795 It isn't 16x9, and I am not sure what it is.
1797 CONFIG_SHARP_LQ64D341
1799 Sharp LQ64D341 display, 640x480.
1800 Active, color, single scan.
1804 HLD1045 display, 640x480.
1805 Active, color, single scan.
1809 Optrex CBL50840-2 NF-FW 99 22 M5
1811 Hitachi LMG6912RPFC-00T
1815 320x240. Black & white.
1817 Normally display is black on white background; define
1818 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1820 CONFIG_LCD_ALIGNMENT
1822 Normally the LCD is page-aligned (typically 4KB). If this is
1823 defined then the LCD will be aligned to this value instead.
1824 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1825 here, since it is cheaper to change data cache settings on
1826 a per-section basis.
1828 CONFIG_CONSOLE_SCROLL_LINES
1830 When the console need to be scrolled, this is the number of
1831 lines to scroll by. It defaults to 1. Increasing this makes
1832 the console jump but can help speed up operation when scrolling
1837 Sometimes, for example if the display is mounted in portrait
1838 mode or even if it's mounted landscape but rotated by 180degree,
1839 we need to rotate our content of the display relative to the
1840 framebuffer, so that user can read the messages which are
1842 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1843 initialized with a given rotation from "vl_rot" out of
1844 "vidinfo_t" which is provided by the board specific code.
1845 The value for vl_rot is coded as following (matching to
1846 fbcon=rotate:<n> linux-kernel commandline):
1847 0 = no rotation respectively 0 degree
1848 1 = 90 degree rotation
1849 2 = 180 degree rotation
1850 3 = 270 degree rotation
1852 If CONFIG_LCD_ROTATION is not defined, the console will be
1853 initialized with 0degree rotation.
1857 Support drawing of RLE8-compressed bitmaps on the LCD.
1861 Enables an 'i2c edid' command which can read EDID
1862 information over I2C from an attached LCD display.
1864 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1866 If this option is set, the environment is checked for
1867 a variable "splashimage". If found, the usual display
1868 of logo, copyright and system information on the LCD
1869 is suppressed and the BMP image at the address
1870 specified in "splashimage" is loaded instead. The
1871 console is redirected to the "nulldev", too. This
1872 allows for a "silent" boot where a splash screen is
1873 loaded very quickly after power-on.
1875 CONFIG_SPLASHIMAGE_GUARD
1877 If this option is set, then U-Boot will prevent the environment
1878 variable "splashimage" from being set to a problematic address
1879 (see doc/README.displaying-bmps).
1880 This option is useful for targets where, due to alignment
1881 restrictions, an improperly aligned BMP image will cause a data
1882 abort. If you think you will not have problems with unaligned
1883 accesses (for example because your toolchain prevents them)
1884 there is no need to set this option.
1886 CONFIG_SPLASH_SCREEN_ALIGN
1888 If this option is set the splash image can be freely positioned
1889 on the screen. Environment variable "splashpos" specifies the
1890 position as "x,y". If a positive number is given it is used as
1891 number of pixel from left/top. If a negative number is given it
1892 is used as number of pixel from right/bottom. You can also
1893 specify 'm' for centering the image.
1896 setenv splashpos m,m
1897 => image at center of screen
1899 setenv splashpos 30,20
1900 => image at x = 30 and y = 20
1902 setenv splashpos -10,m
1903 => vertically centered image
1904 at x = dspWidth - bmpWidth - 9
1906 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1908 If this option is set, additionally to standard BMP
1909 images, gzipped BMP images can be displayed via the
1910 splashscreen support or the bmp command.
1912 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1914 If this option is set, 8-bit RLE compressed BMP images
1915 can be displayed via the splashscreen support or the
1918 - Do compressing for memory range:
1921 If this option is set, it would use zlib deflate method
1922 to compress the specified memory at its best effort.
1924 - Compression support:
1927 Enabled by default to support gzip compressed images.
1931 If this option is set, support for bzip2 compressed
1932 images is included. If not, only uncompressed and gzip
1933 compressed images are supported.
1935 NOTE: the bzip2 algorithm requires a lot of RAM, so
1936 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1941 If this option is set, support for lzma compressed
1944 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1945 requires an amount of dynamic memory that is given by the
1948 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1950 Where lc and lp stand for, respectively, Literal context bits
1951 and Literal pos bits.
1953 This value is upper-bounded by 14MB in the worst case. Anyway,
1954 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1955 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1956 a very small buffer.
1958 Use the lzmainfo tool to determinate the lc and lp values and
1959 then calculate the amount of needed dynamic memory (ensuring
1960 the appropriate CONFIG_SYS_MALLOC_LEN value).
1964 If this option is set, support for LZO compressed images
1970 The address of PHY on MII bus.
1972 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1974 The clock frequency of the MII bus
1978 If this option is set, support for speed/duplex
1979 detection of gigabit PHY is included.
1981 CONFIG_PHY_RESET_DELAY
1983 Some PHY like Intel LXT971A need extra delay after
1984 reset before any MII register access is possible.
1985 For such PHY, set this option to the usec delay
1986 required. (minimum 300usec for LXT971A)
1988 CONFIG_PHY_CMD_DELAY (ppc4xx)
1990 Some PHY like Intel LXT971A need extra delay after
1991 command issued before MII status register can be read
1996 Define a default value for the IP address to use for
1997 the default Ethernet interface, in case this is not
1998 determined through e.g. bootp.
1999 (Environment variable "ipaddr")
2001 - Server IP address:
2004 Defines a default value for the IP address of a TFTP
2005 server to contact when using the "tftboot" command.
2006 (Environment variable "serverip")
2008 CONFIG_KEEP_SERVERADDR
2010 Keeps the server's MAC address, in the env 'serveraddr'
2011 for passing to bootargs (like Linux's netconsole option)
2013 - Gateway IP address:
2016 Defines a default value for the IP address of the
2017 default router where packets to other networks are
2019 (Environment variable "gatewayip")
2024 Defines a default value for the subnet mask (or
2025 routing prefix) which is used to determine if an IP
2026 address belongs to the local subnet or needs to be
2027 forwarded through a router.
2028 (Environment variable "netmask")
2030 - Multicast TFTP Mode:
2033 Defines whether you want to support multicast TFTP as per
2034 rfc-2090; for example to work with atftp. Lets lots of targets
2035 tftp down the same boot image concurrently. Note: the Ethernet
2036 driver in use must provide a function: mcast() to join/leave a
2039 - BOOTP Recovery Mode:
2040 CONFIG_BOOTP_RANDOM_DELAY
2042 If you have many targets in a network that try to
2043 boot using BOOTP, you may want to avoid that all
2044 systems send out BOOTP requests at precisely the same
2045 moment (which would happen for instance at recovery
2046 from a power failure, when all systems will try to
2047 boot, thus flooding the BOOTP server. Defining
2048 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2049 inserted before sending out BOOTP requests. The
2050 following delays are inserted then:
2052 1st BOOTP request: delay 0 ... 1 sec
2053 2nd BOOTP request: delay 0 ... 2 sec
2054 3rd BOOTP request: delay 0 ... 4 sec
2056 BOOTP requests: delay 0 ... 8 sec
2058 CONFIG_BOOTP_ID_CACHE_SIZE
2060 BOOTP packets are uniquely identified using a 32-bit ID. The
2061 server will copy the ID from client requests to responses and
2062 U-Boot will use this to determine if it is the destination of
2063 an incoming response. Some servers will check that addresses
2064 aren't in use before handing them out (usually using an ARP
2065 ping) and therefore take up to a few hundred milliseconds to
2066 respond. Network congestion may also influence the time it
2067 takes for a response to make it back to the client. If that
2068 time is too long, U-Boot will retransmit requests. In order
2069 to allow earlier responses to still be accepted after these
2070 retransmissions, U-Boot's BOOTP client keeps a small cache of
2071 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2072 cache. The default is to keep IDs for up to four outstanding
2073 requests. Increasing this will allow U-Boot to accept offers
2074 from a BOOTP client in networks with unusually high latency.
2076 - DHCP Advanced Options:
2077 You can fine tune the DHCP functionality by defining
2078 CONFIG_BOOTP_* symbols:
2080 CONFIG_BOOTP_SUBNETMASK
2081 CONFIG_BOOTP_GATEWAY
2082 CONFIG_BOOTP_HOSTNAME
2083 CONFIG_BOOTP_NISDOMAIN
2084 CONFIG_BOOTP_BOOTPATH
2085 CONFIG_BOOTP_BOOTFILESIZE
2088 CONFIG_BOOTP_SEND_HOSTNAME
2089 CONFIG_BOOTP_NTPSERVER
2090 CONFIG_BOOTP_TIMEOFFSET
2091 CONFIG_BOOTP_VENDOREX
2092 CONFIG_BOOTP_MAY_FAIL
2094 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2095 environment variable, not the BOOTP server.
2097 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2098 after the configured retry count, the call will fail
2099 instead of starting over. This can be used to fail over
2100 to Link-local IP address configuration if the DHCP server
2103 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2104 serverip from a DHCP server, it is possible that more
2105 than one DNS serverip is offered to the client.
2106 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2107 serverip will be stored in the additional environment
2108 variable "dnsip2". The first DNS serverip is always
2109 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2112 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2113 to do a dynamic update of a DNS server. To do this, they
2114 need the hostname of the DHCP requester.
2115 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2116 of the "hostname" environment variable is passed as
2117 option 12 to the DHCP server.
2119 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2121 A 32bit value in microseconds for a delay between
2122 receiving a "DHCP Offer" and sending the "DHCP Request".
2123 This fixes a problem with certain DHCP servers that don't
2124 respond 100% of the time to a "DHCP request". E.g. On an
2125 AT91RM9200 processor running at 180MHz, this delay needed
2126 to be *at least* 15,000 usec before a Windows Server 2003
2127 DHCP server would reply 100% of the time. I recommend at
2128 least 50,000 usec to be safe. The alternative is to hope
2129 that one of the retries will be successful but note that
2130 the DHCP timeout and retry process takes a longer than
2133 - Link-local IP address negotiation:
2134 Negotiate with other link-local clients on the local network
2135 for an address that doesn't require explicit configuration.
2136 This is especially useful if a DHCP server cannot be guaranteed
2137 to exist in all environments that the device must operate.
2139 See doc/README.link-local for more information.
2142 CONFIG_CDP_DEVICE_ID
2144 The device id used in CDP trigger frames.
2146 CONFIG_CDP_DEVICE_ID_PREFIX
2148 A two character string which is prefixed to the MAC address
2153 A printf format string which contains the ascii name of
2154 the port. Normally is set to "eth%d" which sets
2155 eth0 for the first Ethernet, eth1 for the second etc.
2157 CONFIG_CDP_CAPABILITIES
2159 A 32bit integer which indicates the device capabilities;
2160 0x00000010 for a normal host which does not forwards.
2164 An ascii string containing the version of the software.
2168 An ascii string containing the name of the platform.
2172 A 32bit integer sent on the trigger.
2174 CONFIG_CDP_POWER_CONSUMPTION
2176 A 16bit integer containing the power consumption of the
2177 device in .1 of milliwatts.
2179 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2181 A byte containing the id of the VLAN.
2183 - Status LED: CONFIG_STATUS_LED
2185 Several configurations allow to display the current
2186 status using a LED. For instance, the LED will blink
2187 fast while running U-Boot code, stop blinking as
2188 soon as a reply to a BOOTP request was received, and
2189 start blinking slow once the Linux kernel is running
2190 (supported by a status LED driver in the Linux
2191 kernel). Defining CONFIG_STATUS_LED enables this
2197 The status LED can be connected to a GPIO pin.
2198 In such cases, the gpio_led driver can be used as a
2199 status LED backend implementation. Define CONFIG_GPIO_LED
2200 to include the gpio_led driver in the U-Boot binary.
2202 CONFIG_GPIO_LED_INVERTED_TABLE
2203 Some GPIO connected LEDs may have inverted polarity in which
2204 case the GPIO high value corresponds to LED off state and
2205 GPIO low value corresponds to LED on state.
2206 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2207 with a list of GPIO LEDs that have inverted polarity.
2209 - CAN Support: CONFIG_CAN_DRIVER
2211 Defining CONFIG_CAN_DRIVER enables CAN driver support
2212 on those systems that support this (optional)
2213 feature, like the TQM8xxL modules.
2215 - I2C Support: CONFIG_SYS_I2C
2217 This enable the NEW i2c subsystem, and will allow you to use
2218 i2c commands at the u-boot command line (as long as you set
2219 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2220 based realtime clock chips or other i2c devices. See
2221 common/cmd_i2c.c for a description of the command line
2224 ported i2c driver to the new framework:
2225 - drivers/i2c/soft_i2c.c:
2226 - activate first bus with CONFIG_SYS_I2C_SOFT define
2227 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2228 for defining speed and slave address
2229 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2230 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2231 for defining speed and slave address
2232 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2233 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2234 for defining speed and slave address
2235 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2236 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2237 for defining speed and slave address
2239 - drivers/i2c/fsl_i2c.c:
2240 - activate i2c driver with CONFIG_SYS_I2C_FSL
2241 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2242 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2243 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2245 - If your board supports a second fsl i2c bus, define
2246 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2247 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2248 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2251 - drivers/i2c/tegra_i2c.c:
2252 - activate this driver with CONFIG_SYS_I2C_TEGRA
2253 - This driver adds 4 i2c buses with a fix speed from
2254 100000 and the slave addr 0!
2256 - drivers/i2c/ppc4xx_i2c.c
2257 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2258 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2259 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2261 - drivers/i2c/i2c_mxc.c
2262 - activate this driver with CONFIG_SYS_I2C_MXC
2263 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2264 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2265 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2266 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2267 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2268 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2269 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2270 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2271 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2272 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2273 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2274 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2275 If those defines are not set, default value is 100000
2276 for speed, and 0 for slave.
2278 - drivers/i2c/rcar_i2c.c:
2279 - activate this driver with CONFIG_SYS_I2C_RCAR
2280 - This driver adds 4 i2c buses
2282 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2283 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2284 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2285 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2286 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2287 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2288 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2289 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2290 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2292 - drivers/i2c/sh_i2c.c:
2293 - activate this driver with CONFIG_SYS_I2C_SH
2294 - This driver adds from 2 to 5 i2c buses
2296 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2297 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2298 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2299 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2300 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2301 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2302 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2303 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2304 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2305 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2306 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2307 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2308 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2310 - drivers/i2c/omap24xx_i2c.c
2311 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2312 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2313 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2314 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2315 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2316 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2317 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2318 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2319 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2320 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2321 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2323 - drivers/i2c/zynq_i2c.c
2324 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2325 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2326 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2328 - drivers/i2c/s3c24x0_i2c.c:
2329 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2330 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2331 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2332 with a fix speed from 100000 and the slave addr 0!
2334 - drivers/i2c/ihs_i2c.c
2335 - activate this driver with CONFIG_SYS_I2C_IHS
2336 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2337 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2338 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2339 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2340 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2341 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2342 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2343 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2344 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2345 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2346 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2347 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2348 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2349 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2350 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2351 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2352 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2353 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2354 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2355 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2356 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2360 CONFIG_SYS_NUM_I2C_BUSES
2361 Hold the number of i2c buses you want to use. If you
2362 don't use/have i2c muxes on your i2c bus, this
2363 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2366 CONFIG_SYS_I2C_DIRECT_BUS
2367 define this, if you don't use i2c muxes on your hardware.
2368 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2371 CONFIG_SYS_I2C_MAX_HOPS
2372 define how many muxes are maximal consecutively connected
2373 on one i2c bus. If you not use i2c muxes, omit this
2376 CONFIG_SYS_I2C_BUSES
2377 hold a list of buses you want to use, only used if
2378 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2379 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2380 CONFIG_SYS_NUM_I2C_BUSES = 9:
2382 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2383 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2384 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2385 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2386 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2387 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2388 {1, {I2C_NULL_HOP}}, \
2389 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2390 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2394 bus 0 on adapter 0 without a mux
2395 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2396 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2397 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2398 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2399 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2400 bus 6 on adapter 1 without a mux
2401 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2402 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2404 If you do not have i2c muxes on your board, omit this define.
2406 - Legacy I2C Support: CONFIG_HARD_I2C
2408 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2409 provides the following compelling advantages:
2411 - more than one i2c adapter is usable
2412 - approved multibus support
2413 - better i2c mux support
2415 ** Please consider updating your I2C driver now. **
2417 These enable legacy I2C serial bus commands. Defining
2418 CONFIG_HARD_I2C will include the appropriate I2C driver
2419 for the selected CPU.
2421 This will allow you to use i2c commands at the u-boot
2422 command line (as long as you set CONFIG_CMD_I2C in
2423 CONFIG_COMMANDS) and communicate with i2c based realtime
2424 clock chips. See common/cmd_i2c.c for a description of the
2425 command line interface.
2427 CONFIG_HARD_I2C selects a hardware I2C controller.
2429 There are several other quantities that must also be
2430 defined when you define CONFIG_HARD_I2C.
2432 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2433 to be the frequency (in Hz) at which you wish your i2c bus
2434 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2435 the CPU's i2c node address).
2437 Now, the u-boot i2c code for the mpc8xx
2438 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2439 and so its address should therefore be cleared to 0 (See,
2440 eg, MPC823e User's Manual p.16-473). So, set
2441 CONFIG_SYS_I2C_SLAVE to 0.
2443 CONFIG_SYS_I2C_INIT_MPC5XXX
2445 When a board is reset during an i2c bus transfer
2446 chips might think that the current transfer is still
2447 in progress. Reset the slave devices by sending start
2448 commands until the slave device responds.
2450 That's all that's required for CONFIG_HARD_I2C.
2452 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2453 then the following macros need to be defined (examples are
2454 from include/configs/lwmon.h):
2458 (Optional). Any commands necessary to enable the I2C
2459 controller or configure ports.
2461 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2465 (Only for MPC8260 CPU). The I/O port to use (the code
2466 assumes both bits are on the same port). Valid values
2467 are 0..3 for ports A..D.
2471 The code necessary to make the I2C data line active
2472 (driven). If the data line is open collector, this
2475 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2479 The code necessary to make the I2C data line tri-stated
2480 (inactive). If the data line is open collector, this
2483 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2487 Code that returns true if the I2C data line is high,
2490 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2494 If <bit> is true, sets the I2C data line high. If it
2495 is false, it clears it (low).
2497 eg: #define I2C_SDA(bit) \
2498 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2499 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2503 If <bit> is true, sets the I2C clock line high. If it
2504 is false, it clears it (low).
2506 eg: #define I2C_SCL(bit) \
2507 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2508 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2512 This delay is invoked four times per clock cycle so this
2513 controls the rate of data transfer. The data rate thus
2514 is 1 / (I2C_DELAY * 4). Often defined to be something
2517 #define I2C_DELAY udelay(2)
2519 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2521 If your arch supports the generic GPIO framework (asm/gpio.h),
2522 then you may alternatively define the two GPIOs that are to be
2523 used as SCL / SDA. Any of the previous I2C_xxx macros will
2524 have GPIO-based defaults assigned to them as appropriate.
2526 You should define these to the GPIO value as given directly to
2527 the generic GPIO functions.
2529 CONFIG_SYS_I2C_INIT_BOARD
2531 When a board is reset during an i2c bus transfer
2532 chips might think that the current transfer is still
2533 in progress. On some boards it is possible to access
2534 the i2c SCLK line directly, either by using the
2535 processor pin as a GPIO or by having a second pin
2536 connected to the bus. If this option is defined a
2537 custom i2c_init_board() routine in boards/xxx/board.c
2538 is run early in the boot sequence.
2540 CONFIG_SYS_I2C_BOARD_LATE_INIT
2542 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2543 defined a custom i2c_board_late_init() routine in
2544 boards/xxx/board.c is run AFTER the operations in i2c_init()
2545 is completed. This callpoint can be used to unreset i2c bus
2546 using CPU i2c controller register accesses for CPUs whose i2c
2547 controller provide such a method. It is called at the end of
2548 i2c_init() to allow i2c_init operations to setup the i2c bus
2549 controller on the CPU (e.g. setting bus speed & slave address).
2551 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2553 This option enables configuration of bi_iic_fast[] flags
2554 in u-boot bd_info structure based on u-boot environment
2555 variable "i2cfast". (see also i2cfast)
2557 CONFIG_I2C_MULTI_BUS
2559 This option allows the use of multiple I2C buses, each of which
2560 must have a controller. At any point in time, only one bus is
2561 active. To switch to a different bus, use the 'i2c dev' command.
2562 Note that bus numbering is zero-based.
2564 CONFIG_SYS_I2C_NOPROBES
2566 This option specifies a list of I2C devices that will be skipped
2567 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2568 is set, specify a list of bus-device pairs. Otherwise, specify
2569 a 1D array of device addresses
2572 #undef CONFIG_I2C_MULTI_BUS
2573 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2575 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2577 #define CONFIG_I2C_MULTI_BUS
2578 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2580 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2582 CONFIG_SYS_SPD_BUS_NUM
2584 If defined, then this indicates the I2C bus number for DDR SPD.
2585 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2587 CONFIG_SYS_RTC_BUS_NUM
2589 If defined, then this indicates the I2C bus number for the RTC.
2590 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2592 CONFIG_SYS_DTT_BUS_NUM
2594 If defined, then this indicates the I2C bus number for the DTT.
2595 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2597 CONFIG_SYS_I2C_DTT_ADDR:
2599 If defined, specifies the I2C address of the DTT device.
2600 If not defined, then U-Boot uses predefined value for
2601 specified DTT device.
2603 CONFIG_SOFT_I2C_READ_REPEATED_START
2605 defining this will force the i2c_read() function in
2606 the soft_i2c driver to perform an I2C repeated start
2607 between writing the address pointer and reading the
2608 data. If this define is omitted the default behaviour
2609 of doing a stop-start sequence will be used. Most I2C
2610 devices can use either method, but some require one or
2613 - SPI Support: CONFIG_SPI
2615 Enables SPI driver (so far only tested with
2616 SPI EEPROM, also an instance works with Crystal A/D and
2617 D/As on the SACSng board)
2621 Enables the driver for SPI controller on SuperH. Currently
2622 only SH7757 is supported.
2626 Enables a software (bit-bang) SPI driver rather than
2627 using hardware support. This is a general purpose
2628 driver that only requires three general I/O port pins
2629 (two outputs, one input) to function. If this is
2630 defined, the board configuration must define several
2631 SPI configuration items (port pins to use, etc). For
2632 an example, see include/configs/sacsng.h.
2636 Enables a hardware SPI driver for general-purpose reads
2637 and writes. As with CONFIG_SOFT_SPI, the board configuration
2638 must define a list of chip-select function pointers.
2639 Currently supported on some MPC8xxx processors. For an
2640 example, see include/configs/mpc8349emds.h.
2644 Enables the driver for the SPI controllers on i.MX and MXC
2645 SoCs. Currently i.MX31/35/51 are supported.
2647 CONFIG_SYS_SPI_MXC_WAIT
2648 Timeout for waiting until spi transfer completed.
2649 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2651 - FPGA Support: CONFIG_FPGA
2653 Enables FPGA subsystem.
2655 CONFIG_FPGA_<vendor>
2657 Enables support for specific chip vendors.
2660 CONFIG_FPGA_<family>
2662 Enables support for FPGA family.
2663 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2667 Specify the number of FPGA devices to support.
2669 CONFIG_CMD_FPGA_LOADMK
2671 Enable support for fpga loadmk command
2673 CONFIG_CMD_FPGA_LOADP
2675 Enable support for fpga loadp command - load partial bitstream
2677 CONFIG_CMD_FPGA_LOADBP
2679 Enable support for fpga loadbp command - load partial bitstream
2682 CONFIG_SYS_FPGA_PROG_FEEDBACK
2684 Enable printing of hash marks during FPGA configuration.
2686 CONFIG_SYS_FPGA_CHECK_BUSY
2688 Enable checks on FPGA configuration interface busy
2689 status by the configuration function. This option
2690 will require a board or device specific function to
2695 If defined, a function that provides delays in the FPGA
2696 configuration driver.
2698 CONFIG_SYS_FPGA_CHECK_CTRLC
2699 Allow Control-C to interrupt FPGA configuration
2701 CONFIG_SYS_FPGA_CHECK_ERROR
2703 Check for configuration errors during FPGA bitfile
2704 loading. For example, abort during Virtex II
2705 configuration if the INIT_B line goes low (which
2706 indicated a CRC error).
2708 CONFIG_SYS_FPGA_WAIT_INIT
2710 Maximum time to wait for the INIT_B line to de-assert
2711 after PROB_B has been de-asserted during a Virtex II
2712 FPGA configuration sequence. The default time is 500
2715 CONFIG_SYS_FPGA_WAIT_BUSY
2717 Maximum time to wait for BUSY to de-assert during
2718 Virtex II FPGA configuration. The default is 5 ms.
2720 CONFIG_SYS_FPGA_WAIT_CONFIG
2722 Time to wait after FPGA configuration. The default is
2725 - Configuration Management:
2728 Some SoCs need special image types (e.g. U-Boot binary
2729 with a special header) as build targets. By defining
2730 CONFIG_BUILD_TARGET in the SoC / board header, this
2731 special image will be automatically built upon calling
2736 If defined, this string will be added to the U-Boot
2737 version information (U_BOOT_VERSION)
2739 - Vendor Parameter Protection:
2741 U-Boot considers the values of the environment
2742 variables "serial#" (Board Serial Number) and
2743 "ethaddr" (Ethernet Address) to be parameters that
2744 are set once by the board vendor / manufacturer, and
2745 protects these variables from casual modification by
2746 the user. Once set, these variables are read-only,
2747 and write or delete attempts are rejected. You can
2748 change this behaviour:
2750 If CONFIG_ENV_OVERWRITE is #defined in your config
2751 file, the write protection for vendor parameters is
2752 completely disabled. Anybody can change or delete
2755 Alternatively, if you define _both_ an ethaddr in the
2756 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2757 Ethernet address is installed in the environment,
2758 which can be changed exactly ONCE by the user. [The
2759 serial# is unaffected by this, i. e. it remains
2762 The same can be accomplished in a more flexible way
2763 for any variable by configuring the type of access
2764 to allow for those variables in the ".flags" variable
2765 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2770 Define this variable to enable the reservation of
2771 "protected RAM", i. e. RAM which is not overwritten
2772 by U-Boot. Define CONFIG_PRAM to hold the number of
2773 kB you want to reserve for pRAM. You can overwrite
2774 this default value by defining an environment
2775 variable "pram" to the number of kB you want to
2776 reserve. Note that the board info structure will
2777 still show the full amount of RAM. If pRAM is
2778 reserved, a new environment variable "mem" will
2779 automatically be defined to hold the amount of
2780 remaining RAM in a form that can be passed as boot
2781 argument to Linux, for instance like that:
2783 setenv bootargs ... mem=\${mem}
2786 This way you can tell Linux not to use this memory,
2787 either, which results in a memory region that will
2788 not be affected by reboots.
2790 *WARNING* If your board configuration uses automatic
2791 detection of the RAM size, you must make sure that
2792 this memory test is non-destructive. So far, the
2793 following board configurations are known to be
2796 IVMS8, IVML24, SPD8xx, TQM8xxL,
2797 HERMES, IP860, RPXlite, LWMON,
2800 - Access to physical memory region (> 4GB)
2801 Some basic support is provided for operations on memory not
2802 normally accessible to U-Boot - e.g. some architectures
2803 support access to more than 4GB of memory on 32-bit
2804 machines using physical address extension or similar.
2805 Define CONFIG_PHYSMEM to access this basic support, which
2806 currently only supports clearing the memory.
2811 Define this variable to stop the system in case of a
2812 fatal error, so that you have to reset it manually.
2813 This is probably NOT a good idea for an embedded
2814 system where you want the system to reboot
2815 automatically as fast as possible, but it may be
2816 useful during development since you can try to debug
2817 the conditions that lead to the situation.
2819 CONFIG_NET_RETRY_COUNT
2821 This variable defines the number of retries for
2822 network operations like ARP, RARP, TFTP, or BOOTP
2823 before giving up the operation. If not defined, a
2824 default value of 5 is used.
2828 Timeout waiting for an ARP reply in milliseconds.
2832 Timeout in milliseconds used in NFS protocol.
2833 If you encounter "ERROR: Cannot umount" in nfs command,
2834 try longer timeout such as
2835 #define CONFIG_NFS_TIMEOUT 10000UL
2837 - Command Interpreter:
2838 CONFIG_AUTO_COMPLETE
2840 Enable auto completion of commands using TAB.
2842 CONFIG_SYS_PROMPT_HUSH_PS2
2844 This defines the secondary prompt string, which is
2845 printed when the command interpreter needs more input
2846 to complete a command. Usually "> ".
2850 In the current implementation, the local variables
2851 space and global environment variables space are
2852 separated. Local variables are those you define by
2853 simply typing `name=value'. To access a local
2854 variable later on, you have write `$name' or
2855 `${name}'; to execute the contents of a variable
2856 directly type `$name' at the command prompt.
2858 Global environment variables are those you use
2859 setenv/printenv to work with. To run a command stored
2860 in such a variable, you need to use the run command,
2861 and you must not use the '$' sign to access them.
2863 To store commands and special characters in a
2864 variable, please use double quotation marks
2865 surrounding the whole text of the variable, instead
2866 of the backslashes before semicolons and special
2869 - Command Line Editing and History:
2870 CONFIG_CMDLINE_EDITING
2872 Enable editing and History functions for interactive
2873 command line input operations
2875 - Command Line PS1/PS2 support:
2876 CONFIG_CMDLINE_PS_SUPPORT
2878 Enable support for changing the command prompt string
2879 at run-time. Only static string is supported so far.
2880 The string is obtained from environment variables PS1
2883 - Default Environment:
2884 CONFIG_EXTRA_ENV_SETTINGS
2886 Define this to contain any number of null terminated
2887 strings (variable = value pairs) that will be part of
2888 the default environment compiled into the boot image.
2890 For example, place something like this in your
2891 board's config file:
2893 #define CONFIG_EXTRA_ENV_SETTINGS \
2897 Warning: This method is based on knowledge about the
2898 internal format how the environment is stored by the
2899 U-Boot code. This is NOT an official, exported
2900 interface! Although it is unlikely that this format
2901 will change soon, there is no guarantee either.
2902 You better know what you are doing here.
2904 Note: overly (ab)use of the default environment is
2905 discouraged. Make sure to check other ways to preset
2906 the environment like the "source" command or the
2909 CONFIG_ENV_VARS_UBOOT_CONFIG
2911 Define this in order to add variables describing the
2912 U-Boot build configuration to the default environment.
2913 These will be named arch, cpu, board, vendor, and soc.
2915 Enabling this option will cause the following to be defined:
2923 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2925 Define this in order to add variables describing certain
2926 run-time determined information about the hardware to the
2927 environment. These will be named board_name, board_rev.
2929 CONFIG_DELAY_ENVIRONMENT
2931 Normally the environment is loaded when the board is
2932 initialised so that it is available to U-Boot. This inhibits
2933 that so that the environment is not available until
2934 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2935 this is instead controlled by the value of
2936 /config/load-environment.
2938 - Parallel Flash support:
2941 Traditionally U-Boot was run on systems with parallel NOR
2942 flash. This option is used to disable support for parallel NOR
2943 flash. This option should be defined if the board does not have
2946 If this option is not defined one of the generic flash drivers
2947 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2948 selected or the board must provide an implementation of the
2949 flash API (see include/flash.h).
2951 - DataFlash Support:
2952 CONFIG_HAS_DATAFLASH
2954 Defining this option enables DataFlash features and
2955 allows to read/write in Dataflash via the standard
2958 - Serial Flash support
2961 Defining this option enables SPI flash commands
2962 'sf probe/read/write/erase/update'.
2964 Usage requires an initial 'probe' to define the serial
2965 flash parameters, followed by read/write/erase/update
2968 The following defaults may be provided by the platform
2969 to handle the common case when only a single serial
2970 flash is present on the system.
2972 CONFIG_SF_DEFAULT_BUS Bus identifier
2973 CONFIG_SF_DEFAULT_CS Chip-select
2974 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2975 CONFIG_SF_DEFAULT_SPEED in Hz
2979 Define this option to include a destructive SPI flash
2982 CONFIG_SF_DUAL_FLASH Dual flash memories
2984 Define this option to use dual flash support where two flash
2985 memories can be connected with a given cs line.
2986 Currently Xilinx Zynq qspi supports these type of connections.
2988 - SystemACE Support:
2991 Adding this option adds support for Xilinx SystemACE
2992 chips attached via some sort of local bus. The address
2993 of the chip must also be defined in the
2994 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2996 #define CONFIG_SYSTEMACE
2997 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2999 When SystemACE support is added, the "ace" device type
3000 becomes available to the fat commands, i.e. fatls.
3002 - TFTP Fixed UDP Port:
3005 If this is defined, the environment variable tftpsrcp
3006 is used to supply the TFTP UDP source port value.
3007 If tftpsrcp isn't defined, the normal pseudo-random port
3008 number generator is used.
3010 Also, the environment variable tftpdstp is used to supply
3011 the TFTP UDP destination port value. If tftpdstp isn't
3012 defined, the normal port 69 is used.
3014 The purpose for tftpsrcp is to allow a TFTP server to
3015 blindly start the TFTP transfer using the pre-configured
3016 target IP address and UDP port. This has the effect of
3017 "punching through" the (Windows XP) firewall, allowing
3018 the remainder of the TFTP transfer to proceed normally.
3019 A better solution is to properly configure the firewall,
3020 but sometimes that is not allowed.
3025 This enables a generic 'hash' command which can produce
3026 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3030 Enable the hash verify command (hash -v). This adds to code
3033 CONFIG_SHA1 - This option enables support of hashing using SHA1
3034 algorithm. The hash is calculated in software.
3035 CONFIG_SHA256 - This option enables support of hashing using
3036 SHA256 algorithm. The hash is calculated in software.
3037 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3038 for SHA1/SHA256 hashing.
3039 This affects the 'hash' command and also the
3040 hash_lookup_algo() function.
3041 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3042 hardware-acceleration for SHA1/SHA256 progressive hashing.
3043 Data can be streamed in a block at a time and the hashing
3044 is performed in hardware.
3046 Note: There is also a sha1sum command, which should perhaps
3047 be deprecated in favour of 'hash sha1'.
3049 - Freescale i.MX specific commands:
3050 CONFIG_CMD_HDMIDETECT
3051 This enables 'hdmidet' command which returns true if an
3052 HDMI monitor is detected. This command is i.MX 6 specific.
3055 This enables the 'bmode' (bootmode) command for forcing
3056 a boot from specific media.
3058 This is useful for forcing the ROM's usb downloader to
3059 activate upon a watchdog reset which is nice when iterating
3060 on U-Boot. Using the reset button or running bmode normal
3061 will set it back to normal. This command currently
3062 supports i.MX53 and i.MX6.
3064 - bootcount support:
3065 CONFIG_BOOTCOUNT_LIMIT
3067 This enables the bootcounter support, see:
3068 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3071 enable special bootcounter support on at91sam9xe based boards.
3073 enable special bootcounter support on blackfin based boards.
3075 enable special bootcounter support on da850 based boards.
3076 CONFIG_BOOTCOUNT_RAM
3077 enable support for the bootcounter in RAM
3078 CONFIG_BOOTCOUNT_I2C
3079 enable support for the bootcounter on an i2c (like RTC) device.
3080 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3081 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3083 CONFIG_BOOTCOUNT_ALEN = address len
3085 - Show boot progress:
3086 CONFIG_SHOW_BOOT_PROGRESS
3088 Defining this option allows to add some board-
3089 specific code (calling a user-provided function
3090 "show_boot_progress(int)") that enables you to show
3091 the system's boot progress on some display (for
3092 example, some LED's) on your board. At the moment,
3093 the following checkpoints are implemented:
3096 Legacy uImage format:
3099 1 common/cmd_bootm.c before attempting to boot an image
3100 -1 common/cmd_bootm.c Image header has bad magic number
3101 2 common/cmd_bootm.c Image header has correct magic number
3102 -2 common/cmd_bootm.c Image header has bad checksum
3103 3 common/cmd_bootm.c Image header has correct checksum
3104 -3 common/cmd_bootm.c Image data has bad checksum
3105 4 common/cmd_bootm.c Image data has correct checksum
3106 -4 common/cmd_bootm.c Image is for unsupported architecture
3107 5 common/cmd_bootm.c Architecture check OK
3108 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3109 6 common/cmd_bootm.c Image Type check OK
3110 -6 common/cmd_bootm.c gunzip uncompression error
3111 -7 common/cmd_bootm.c Unimplemented compression type
3112 7 common/cmd_bootm.c Uncompression OK
3113 8 common/cmd_bootm.c No uncompress/copy overwrite error
3114 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3116 9 common/image.c Start initial ramdisk verification
3117 -10 common/image.c Ramdisk header has bad magic number
3118 -11 common/image.c Ramdisk header has bad checksum
3119 10 common/image.c Ramdisk header is OK
3120 -12 common/image.c Ramdisk data has bad checksum
3121 11 common/image.c Ramdisk data has correct checksum
3122 12 common/image.c Ramdisk verification complete, start loading
3123 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3124 13 common/image.c Start multifile image verification
3125 14 common/image.c No initial ramdisk, no multifile, continue.
3127 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3129 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3130 -31 post/post.c POST test failed, detected by post_output_backlog()
3131 -32 post/post.c POST test failed, detected by post_run_single()
3133 34 common/cmd_doc.c before loading a Image from a DOC device
3134 -35 common/cmd_doc.c Bad usage of "doc" command
3135 35 common/cmd_doc.c correct usage of "doc" command
3136 -36 common/cmd_doc.c No boot device
3137 36 common/cmd_doc.c correct boot device
3138 -37 common/cmd_doc.c Unknown Chip ID on boot device
3139 37 common/cmd_doc.c correct chip ID found, device available
3140 -38 common/cmd_doc.c Read Error on boot device
3141 38 common/cmd_doc.c reading Image header from DOC device OK
3142 -39 common/cmd_doc.c Image header has bad magic number
3143 39 common/cmd_doc.c Image header has correct magic number
3144 -40 common/cmd_doc.c Error reading Image from DOC device
3145 40 common/cmd_doc.c Image header has correct magic number
3146 41 common/cmd_ide.c before loading a Image from a IDE device
3147 -42 common/cmd_ide.c Bad usage of "ide" command
3148 42 common/cmd_ide.c correct usage of "ide" command
3149 -43 common/cmd_ide.c No boot device
3150 43 common/cmd_ide.c boot device found
3151 -44 common/cmd_ide.c Device not available
3152 44 common/cmd_ide.c Device available
3153 -45 common/cmd_ide.c wrong partition selected
3154 45 common/cmd_ide.c partition selected
3155 -46 common/cmd_ide.c Unknown partition table
3156 46 common/cmd_ide.c valid partition table found
3157 -47 common/cmd_ide.c Invalid partition type
3158 47 common/cmd_ide.c correct partition type
3159 -48 common/cmd_ide.c Error reading Image Header on boot device
3160 48 common/cmd_ide.c reading Image Header from IDE device OK
3161 -49 common/cmd_ide.c Image header has bad magic number
3162 49 common/cmd_ide.c Image header has correct magic number
3163 -50 common/cmd_ide.c Image header has bad checksum
3164 50 common/cmd_ide.c Image header has correct checksum
3165 -51 common/cmd_ide.c Error reading Image from IDE device
3166 51 common/cmd_ide.c reading Image from IDE device OK
3167 52 common/cmd_nand.c before loading a Image from a NAND device
3168 -53 common/cmd_nand.c Bad usage of "nand" command
3169 53 common/cmd_nand.c correct usage of "nand" command
3170 -54 common/cmd_nand.c No boot device
3171 54 common/cmd_nand.c boot device found
3172 -55 common/cmd_nand.c Unknown Chip ID on boot device
3173 55 common/cmd_nand.c correct chip ID found, device available
3174 -56 common/cmd_nand.c Error reading Image Header on boot device
3175 56 common/cmd_nand.c reading Image Header from NAND device OK
3176 -57 common/cmd_nand.c Image header has bad magic number
3177 57 common/cmd_nand.c Image header has correct magic number
3178 -58 common/cmd_nand.c Error reading Image from NAND device
3179 58 common/cmd_nand.c reading Image from NAND device OK
3181 -60 common/env_common.c Environment has a bad CRC, using default
3183 64 net/eth.c starting with Ethernet configuration.
3184 -64 net/eth.c no Ethernet found.
3185 65 net/eth.c Ethernet found.
3187 -80 common/cmd_net.c usage wrong
3188 80 common/cmd_net.c before calling net_loop()
3189 -81 common/cmd_net.c some error in net_loop() occurred
3190 81 common/cmd_net.c net_loop() back without error
3191 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3192 82 common/cmd_net.c trying automatic boot
3193 83 common/cmd_net.c running "source" command
3194 -83 common/cmd_net.c some error in automatic boot or "source" command
3195 84 common/cmd_net.c end without errors
3200 100 common/cmd_bootm.c Kernel FIT Image has correct format
3201 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3202 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3203 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3204 102 common/cmd_bootm.c Kernel unit name specified
3205 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3206 103 common/cmd_bootm.c Found configuration node
3207 104 common/cmd_bootm.c Got kernel subimage node offset
3208 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3209 105 common/cmd_bootm.c Kernel subimage hash verification OK
3210 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3211 106 common/cmd_bootm.c Architecture check OK
3212 -106 common/cmd_bootm.c Kernel subimage has wrong type
3213 107 common/cmd_bootm.c Kernel subimage type OK
3214 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3215 108 common/cmd_bootm.c Got kernel subimage data/size
3216 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3217 -109 common/cmd_bootm.c Can't get kernel subimage type
3218 -110 common/cmd_bootm.c Can't get kernel subimage comp
3219 -111 common/cmd_bootm.c Can't get kernel subimage os
3220 -112 common/cmd_bootm.c Can't get kernel subimage load address
3221 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3223 120 common/image.c Start initial ramdisk verification
3224 -120 common/image.c Ramdisk FIT image has incorrect format
3225 121 common/image.c Ramdisk FIT image has correct format
3226 122 common/image.c No ramdisk subimage unit name, using configuration
3227 -122 common/image.c Can't get configuration for ramdisk subimage
3228 123 common/image.c Ramdisk unit name specified
3229 -124 common/image.c Can't get ramdisk subimage node offset
3230 125 common/image.c Got ramdisk subimage node offset
3231 -125 common/image.c Ramdisk subimage hash verification failed
3232 126 common/image.c Ramdisk subimage hash verification OK
3233 -126 common/image.c Ramdisk subimage for unsupported architecture
3234 127 common/image.c Architecture check OK
3235 -127 common/image.c Can't get ramdisk subimage data/size
3236 128 common/image.c Got ramdisk subimage data/size
3237 129 common/image.c Can't get ramdisk load address
3238 -129 common/image.c Got ramdisk load address
3240 -130 common/cmd_doc.c Incorrect FIT image format
3241 131 common/cmd_doc.c FIT image format OK
3243 -140 common/cmd_ide.c Incorrect FIT image format
3244 141 common/cmd_ide.c FIT image format OK
3246 -150 common/cmd_nand.c Incorrect FIT image format
3247 151 common/cmd_nand.c FIT image format OK
3249 - legacy image format:
3250 CONFIG_IMAGE_FORMAT_LEGACY
3251 enables the legacy image format support in U-Boot.
3254 enabled if CONFIG_FIT_SIGNATURE is not defined.
3256 CONFIG_DISABLE_IMAGE_LEGACY
3257 disable the legacy image format
3259 This define is introduced, as the legacy image format is
3260 enabled per default for backward compatibility.
3262 - FIT image support:
3263 CONFIG_FIT_DISABLE_SHA256
3264 Supporting SHA256 hashes has quite an impact on binary size.
3265 For constrained systems sha256 hash support can be disabled
3268 TODO(sjg@chromium.org): Adjust this option to be positive,
3269 and move it to Kconfig
3271 - Standalone program support:
3272 CONFIG_STANDALONE_LOAD_ADDR
3274 This option defines a board specific value for the
3275 address where standalone program gets loaded, thus
3276 overwriting the architecture dependent default
3279 - Frame Buffer Address:
3282 Define CONFIG_FB_ADDR if you want to use specific
3283 address for frame buffer. This is typically the case
3284 when using a graphics controller has separate video
3285 memory. U-Boot will then place the frame buffer at
3286 the given address instead of dynamically reserving it
3287 in system RAM by calling lcd_setmem(), which grabs
3288 the memory for the frame buffer depending on the
3289 configured panel size.
3291 Please see board_init_f function.
3293 - Automatic software updates via TFTP server
3295 CONFIG_UPDATE_TFTP_CNT_MAX
3296 CONFIG_UPDATE_TFTP_MSEC_MAX
3298 These options enable and control the auto-update feature;
3299 for a more detailed description refer to doc/README.update.
3301 - MTD Support (mtdparts command, UBI support)
3304 Adds the MTD device infrastructure from the Linux kernel.
3305 Needed for mtdparts command support.
3307 CONFIG_MTD_PARTITIONS
3309 Adds the MTD partitioning infrastructure from the Linux
3310 kernel. Needed for UBI support.
3315 Adds commands for interacting with MTD partitions formatted
3316 with the UBI flash translation layer
3318 Requires also defining CONFIG_RBTREE
3320 CONFIG_UBI_SILENCE_MSG
3322 Make the verbose messages from UBI stop printing. This leaves
3323 warnings and errors enabled.
3326 CONFIG_MTD_UBI_WL_THRESHOLD
3327 This parameter defines the maximum difference between the highest
3328 erase counter value and the lowest erase counter value of eraseblocks
3329 of UBI devices. When this threshold is exceeded, UBI starts performing
3330 wear leveling by means of moving data from eraseblock with low erase
3331 counter to eraseblocks with high erase counter.
3333 The default value should be OK for SLC NAND flashes, NOR flashes and
3334 other flashes which have eraseblock life-cycle 100000 or more.
3335 However, in case of MLC NAND flashes which typically have eraseblock
3336 life-cycle less than 10000, the threshold should be lessened (e.g.,
3337 to 128 or 256, although it does not have to be power of 2).
3341 CONFIG_MTD_UBI_BEB_LIMIT
3342 This option specifies the maximum bad physical eraseblocks UBI
3343 expects on the MTD device (per 1024 eraseblocks). If the
3344 underlying flash does not admit of bad eraseblocks (e.g. NOR
3345 flash), this value is ignored.
3347 NAND datasheets often specify the minimum and maximum NVM
3348 (Number of Valid Blocks) for the flashes' endurance lifetime.
3349 The maximum expected bad eraseblocks per 1024 eraseblocks
3350 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3351 which gives 20 for most NANDs (MaxNVB is basically the total
3352 count of eraseblocks on the chip).
3354 To put it differently, if this value is 20, UBI will try to
3355 reserve about 1.9% of physical eraseblocks for bad blocks
3356 handling. And that will be 1.9% of eraseblocks on the entire
3357 NAND chip, not just the MTD partition UBI attaches. This means
3358 that if you have, say, a NAND flash chip admits maximum 40 bad
3359 eraseblocks, and it is split on two MTD partitions of the same
3360 size, UBI will reserve 40 eraseblocks when attaching a
3365 CONFIG_MTD_UBI_FASTMAP
3366 Fastmap is a mechanism which allows attaching an UBI device
3367 in nearly constant time. Instead of scanning the whole MTD device it
3368 only has to locate a checkpoint (called fastmap) on the device.
3369 The on-flash fastmap contains all information needed to attach
3370 the device. Using fastmap makes only sense on large devices where
3371 attaching by scanning takes long. UBI will not automatically install
3372 a fastmap on old images, but you can set the UBI parameter
3373 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3374 that fastmap-enabled images are still usable with UBI implementations
3375 without fastmap support. On typical flash devices the whole fastmap
3376 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3378 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3379 Set this parameter to enable fastmap automatically on images
3383 CONFIG_MTD_UBI_FM_DEBUG
3384 Enable UBI fastmap debug
3390 Adds commands for interacting with UBI volumes formatted as
3391 UBIFS. UBIFS is read-only in u-boot.
3393 Requires UBI support as well as CONFIG_LZO
3395 CONFIG_UBIFS_SILENCE_MSG
3397 Make the verbose messages from UBIFS stop printing. This leaves
3398 warnings and errors enabled.
3402 Enable building of SPL globally.
3405 LDSCRIPT for linking the SPL binary.
3407 CONFIG_SPL_MAX_FOOTPRINT
3408 Maximum size in memory allocated to the SPL, BSS included.
3409 When defined, the linker checks that the actual memory
3410 used by SPL from _start to __bss_end does not exceed it.
3411 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3412 must not be both defined at the same time.
3415 Maximum size of the SPL image (text, data, rodata, and
3416 linker lists sections), BSS excluded.
3417 When defined, the linker checks that the actual size does
3420 CONFIG_SPL_TEXT_BASE
3421 TEXT_BASE for linking the SPL binary.
3423 CONFIG_SPL_RELOC_TEXT_BASE
3424 Address to relocate to. If unspecified, this is equal to
3425 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3427 CONFIG_SPL_BSS_START_ADDR
3428 Link address for the BSS within the SPL binary.
3430 CONFIG_SPL_BSS_MAX_SIZE
3431 Maximum size in memory allocated to the SPL BSS.
3432 When defined, the linker checks that the actual memory used
3433 by SPL from __bss_start to __bss_end does not exceed it.
3434 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3435 must not be both defined at the same time.
3438 Adress of the start of the stack SPL will use
3440 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3441 When defined, SPL will panic() if the image it has
3442 loaded does not have a signature.
3443 Defining this is useful when code which loads images
3444 in SPL cannot guarantee that absolutely all read errors
3446 An example is the LPC32XX MLC NAND driver, which will
3447 consider that a completely unreadable NAND block is bad,
3448 and thus should be skipped silently.
3450 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3451 When defined, SPL will proceed to another boot method
3452 if the image it has loaded does not have a signature.
3454 CONFIG_SPL_RELOC_STACK
3455 Adress of the start of the stack SPL will use after
3456 relocation. If unspecified, this is equal to
3459 CONFIG_SYS_SPL_MALLOC_START
3460 Starting address of the malloc pool used in SPL.
3461 When this option is set the full malloc is used in SPL and
3462 it is set up by spl_init() and before that, the simple malloc()
3463 can be used if CONFIG_SYS_MALLOC_F is defined.
3465 CONFIG_SYS_SPL_MALLOC_SIZE
3466 The size of the malloc pool used in SPL.
3468 CONFIG_SPL_FRAMEWORK
3469 Enable the SPL framework under common/. This framework
3470 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3471 NAND loading of the Linux Kernel.
3474 Enable booting directly to an OS from SPL.
3475 See also: doc/README.falcon
3477 CONFIG_SPL_DISPLAY_PRINT
3478 For ARM, enable an optional function to print more information
3479 about the running system.
3481 CONFIG_SPL_INIT_MINIMAL
3482 Arch init code should be built for a very small image
3484 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3485 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3486 Address and partition on the MMC to load U-Boot from
3487 when the MMC is being used in raw mode.
3489 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3490 Partition on the MMC to load U-Boot from when the MMC is being
3493 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3494 Sector to load kernel uImage from when MMC is being
3495 used in raw mode (for Falcon mode)
3497 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3498 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3499 Sector and number of sectors to load kernel argument
3500 parameters from when MMC is being used in raw mode
3503 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3504 Partition on the MMC to load U-Boot from when the MMC is being
3507 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3508 Filename to read to load U-Boot when reading from filesystem
3510 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3511 Filename to read to load kernel uImage when reading
3512 from filesystem (for Falcon mode)
3514 CONFIG_SPL_FS_LOAD_ARGS_NAME
3515 Filename to read to load kernel argument parameters
3516 when reading from filesystem (for Falcon mode)
3518 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3519 Set this for NAND SPL on PPC mpc83xx targets, so that
3520 start.S waits for the rest of the SPL to load before
3521 continuing (the hardware starts execution after just
3522 loading the first page rather than the full 4K).
3524 CONFIG_SPL_SKIP_RELOCATE
3525 Avoid SPL relocation
3527 CONFIG_SPL_NAND_BASE
3528 Include nand_base.c in the SPL. Requires
3529 CONFIG_SPL_NAND_DRIVERS.
3531 CONFIG_SPL_NAND_DRIVERS
3532 SPL uses normal NAND drivers, not minimal drivers.
3535 Include standard software ECC in the SPL
3537 CONFIG_SPL_NAND_SIMPLE
3538 Support for NAND boot using simple NAND drivers that
3539 expose the cmd_ctrl() interface.
3542 Support for a lightweight UBI (fastmap) scanner and
3545 CONFIG_SPL_NAND_RAW_ONLY
3546 Support to boot only raw u-boot.bin images. Use this only
3547 if you need to save space.
3549 CONFIG_SPL_COMMON_INIT_DDR
3550 Set for common ddr init with serial presence detect in
3553 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3554 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3555 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3556 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3557 CONFIG_SYS_NAND_ECCBYTES
3558 Defines the size and behavior of the NAND that SPL uses
3561 CONFIG_SPL_NAND_BOOT
3562 Add support NAND boot
3564 CONFIG_SYS_NAND_U_BOOT_OFFS
3565 Location in NAND to read U-Boot from
3567 CONFIG_SYS_NAND_U_BOOT_DST
3568 Location in memory to load U-Boot to
3570 CONFIG_SYS_NAND_U_BOOT_SIZE
3571 Size of image to load
3573 CONFIG_SYS_NAND_U_BOOT_START
3574 Entry point in loaded image to jump to
3576 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3577 Define this if you need to first read the OOB and then the
3578 data. This is used, for example, on davinci platforms.
3580 CONFIG_SPL_OMAP3_ID_NAND
3581 Support for an OMAP3-specific set of functions to return the
3582 ID and MFR of the first attached NAND chip, if present.
3584 CONFIG_SPL_RAM_DEVICE
3585 Support for running image already present in ram, in SPL binary
3588 Image offset to which the SPL should be padded before appending
3589 the SPL payload. By default, this is defined as
3590 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3591 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3592 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3595 Final target image containing SPL and payload. Some SPLs
3596 use an arch-specific makefile fragment instead, for
3597 example if more than one image needs to be produced.
3599 CONFIG_FIT_SPL_PRINT
3600 Printing information about a FIT image adds quite a bit of
3601 code to SPL. So this is normally disabled in SPL. Use this
3602 option to re-enable it. This will affect the output of the
3603 bootm command when booting a FIT image.
3607 Enable building of TPL globally.
3610 Image offset to which the TPL should be padded before appending
3611 the TPL payload. By default, this is defined as
3612 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3613 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3614 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3616 - Interrupt support (PPC):
3618 There are common interrupt_init() and timer_interrupt()
3619 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3620 for CPU specific initialization. interrupt_init_cpu()
3621 should set decrementer_count to appropriate value. If
3622 CPU resets decrementer automatically after interrupt
3623 (ppc4xx) it should set decrementer_count to zero.
3624 timer_interrupt() calls timer_interrupt_cpu() for CPU
3625 specific handling. If board has watchdog / status_led
3626 / other_activity_monitor it works automatically from
3627 general timer_interrupt().
3630 Board initialization settings:
3631 ------------------------------
3633 During Initialization u-boot calls a number of board specific functions
3634 to allow the preparation of board specific prerequisites, e.g. pin setup
3635 before drivers are initialized. To enable these callbacks the
3636 following configuration macros have to be defined. Currently this is
3637 architecture specific, so please check arch/your_architecture/lib/board.c
3638 typically in board_init_f() and board_init_r().
3640 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3641 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3642 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3643 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3645 Configuration Settings:
3646 -----------------------
3648 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3649 Optionally it can be defined to support 64-bit memory commands.
3651 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3652 undefine this when you're short of memory.
3654 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3655 width of the commands listed in the 'help' command output.
3657 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3658 prompt for user input.
3660 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3662 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3664 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3666 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3667 the application (usually a Linux kernel) when it is
3670 - CONFIG_SYS_BAUDRATE_TABLE:
3671 List of legal baudrate settings for this board.
3673 - CONFIG_SYS_CONSOLE_INFO_QUIET
3674 Suppress display of console information at boot.
3676 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3677 If the board specific function
3678 extern int overwrite_console (void);
3679 returns 1, the stdin, stderr and stdout are switched to the
3680 serial port, else the settings in the environment are used.
3682 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3683 Enable the call to overwrite_console().
3685 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3686 Enable overwrite of previous console environment settings.
3688 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3689 Begin and End addresses of the area used by the
3692 - CONFIG_SYS_ALT_MEMTEST:
3693 Enable an alternate, more extensive memory test.
3695 - CONFIG_SYS_MEMTEST_SCRATCH:
3696 Scratch address used by the alternate memory test
3697 You only need to set this if address zero isn't writeable
3699 - CONFIG_SYS_MEM_RESERVE_SECURE
3700 Only implemented for ARMv8 for now.
3701 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3702 is substracted from total RAM and won't be reported to OS.
3703 This memory can be used as secure memory. A variable
3704 gd->arch.secure_ram is used to track the location. In systems
3705 the RAM base is not zero, or RAM is divided into banks,
3706 this variable needs to be recalcuated to get the address.
3708 - CONFIG_SYS_MEM_TOP_HIDE:
3709 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3710 this specified memory area will get subtracted from the top
3711 (end) of RAM and won't get "touched" at all by U-Boot. By
3712 fixing up gd->ram_size the Linux kernel should gets passed
3713 the now "corrected" memory size and won't touch it either.
3714 This should work for arch/ppc and arch/powerpc. Only Linux
3715 board ports in arch/powerpc with bootwrapper support that
3716 recalculate the memory size from the SDRAM controller setup
3717 will have to get fixed in Linux additionally.
3719 This option can be used as a workaround for the 440EPx/GRx
3720 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3723 WARNING: Please make sure that this value is a multiple of
3724 the Linux page size (normally 4k). If this is not the case,
3725 then the end address of the Linux memory will be located at a
3726 non page size aligned address and this could cause major
3729 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3730 Enable temporary baudrate change while serial download
3732 - CONFIG_SYS_SDRAM_BASE:
3733 Physical start address of SDRAM. _Must_ be 0 here.
3735 - CONFIG_SYS_FLASH_BASE:
3736 Physical start address of Flash memory.
3738 - CONFIG_SYS_MONITOR_BASE:
3739 Physical start address of boot monitor code (set by
3740 make config files to be same as the text base address
3741 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3742 CONFIG_SYS_FLASH_BASE when booting from flash.
3744 - CONFIG_SYS_MONITOR_LEN:
3745 Size of memory reserved for monitor code, used to
3746 determine _at_compile_time_ (!) if the environment is
3747 embedded within the U-Boot image, or in a separate
3750 - CONFIG_SYS_MALLOC_LEN:
3751 Size of DRAM reserved for malloc() use.
3753 - CONFIG_SYS_MALLOC_F_LEN
3754 Size of the malloc() pool for use before relocation. If
3755 this is defined, then a very simple malloc() implementation
3756 will become available before relocation. The address is just
3757 below the global data, and the stack is moved down to make
3760 This feature allocates regions with increasing addresses
3761 within the region. calloc() is supported, but realloc()
3762 is not available. free() is supported but does nothing.
3763 The memory will be freed (or in fact just forgotten) when
3764 U-Boot relocates itself.
3766 - CONFIG_SYS_MALLOC_SIMPLE
3767 Provides a simple and small malloc() and calloc() for those
3768 boards which do not use the full malloc in SPL (which is
3769 enabled with CONFIG_SYS_SPL_MALLOC_START).
3771 - CONFIG_SYS_NONCACHED_MEMORY:
3772 Size of non-cached memory area. This area of memory will be
3773 typically located right below the malloc() area and mapped
3774 uncached in the MMU. This is useful for drivers that would
3775 otherwise require a lot of explicit cache maintenance. For
3776 some drivers it's also impossible to properly maintain the
3777 cache. For example if the regions that need to be flushed
3778 are not a multiple of the cache-line size, *and* padding
3779 cannot be allocated between the regions to align them (i.e.
3780 if the HW requires a contiguous array of regions, and the
3781 size of each region is not cache-aligned), then a flush of
3782 one region may result in overwriting data that hardware has
3783 written to another region in the same cache-line. This can
3784 happen for example in network drivers where descriptors for
3785 buffers are typically smaller than the CPU cache-line (e.g.
3786 16 bytes vs. 32 or 64 bytes).
3788 Non-cached memory is only supported on 32-bit ARM at present.
3790 - CONFIG_SYS_BOOTM_LEN:
3791 Normally compressed uImages are limited to an
3792 uncompressed size of 8 MBytes. If this is not enough,
3793 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3794 to adjust this setting to your needs.
3796 - CONFIG_SYS_BOOTMAPSZ:
3797 Maximum size of memory mapped by the startup code of
3798 the Linux kernel; all data that must be processed by
3799 the Linux kernel (bd_info, boot arguments, FDT blob if
3800 used) must be put below this limit, unless "bootm_low"
3801 environment variable is defined and non-zero. In such case
3802 all data for the Linux kernel must be between "bootm_low"
3803 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3804 variable "bootm_mapsize" will override the value of
3805 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3806 then the value in "bootm_size" will be used instead.
3808 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3809 Enable initrd_high functionality. If defined then the
3810 initrd_high feature is enabled and the bootm ramdisk subcommand
3813 - CONFIG_SYS_BOOT_GET_CMDLINE:
3814 Enables allocating and saving kernel cmdline in space between
3815 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3817 - CONFIG_SYS_BOOT_GET_KBD:
3818 Enables allocating and saving a kernel copy of the bd_info in
3819 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3821 - CONFIG_SYS_MAX_FLASH_BANKS:
3822 Max number of Flash memory banks
3824 - CONFIG_SYS_MAX_FLASH_SECT:
3825 Max number of sectors on a Flash chip
3827 - CONFIG_SYS_FLASH_ERASE_TOUT:
3828 Timeout for Flash erase operations (in ms)
3830 - CONFIG_SYS_FLASH_WRITE_TOUT:
3831 Timeout for Flash write operations (in ms)
3833 - CONFIG_SYS_FLASH_LOCK_TOUT
3834 Timeout for Flash set sector lock bit operation (in ms)
3836 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3837 Timeout for Flash clear lock bits operation (in ms)
3839 - CONFIG_SYS_FLASH_PROTECTION
3840 If defined, hardware flash sectors protection is used
3841 instead of U-Boot software protection.
3843 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3845 Enable TFTP transfers directly to flash memory;
3846 without this option such a download has to be
3847 performed in two steps: (1) download to RAM, and (2)
3848 copy from RAM to flash.
3850 The two-step approach is usually more reliable, since
3851 you can check if the download worked before you erase
3852 the flash, but in some situations (when system RAM is
3853 too limited to allow for a temporary copy of the
3854 downloaded image) this option may be very useful.
3856 - CONFIG_SYS_FLASH_CFI:
3857 Define if the flash driver uses extra elements in the
3858 common flash structure for storing flash geometry.
3860 - CONFIG_FLASH_CFI_DRIVER
3861 This option also enables the building of the cfi_flash driver
3862 in the drivers directory
3864 - CONFIG_FLASH_CFI_MTD
3865 This option enables the building of the cfi_mtd driver
3866 in the drivers directory. The driver exports CFI flash
3869 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3870 Use buffered writes to flash.
3872 - CONFIG_FLASH_SPANSION_S29WS_N
3873 s29ws-n MirrorBit flash has non-standard addresses for buffered
3876 - CONFIG_SYS_FLASH_QUIET_TEST
3877 If this option is defined, the common CFI flash doesn't
3878 print it's warning upon not recognized FLASH banks. This
3879 is useful, if some of the configured banks are only
3880 optionally available.
3882 - CONFIG_FLASH_SHOW_PROGRESS
3883 If defined (must be an integer), print out countdown
3884 digits and dots. Recommended value: 45 (9..1) for 80
3885 column displays, 15 (3..1) for 40 column displays.
3887 - CONFIG_FLASH_VERIFY
3888 If defined, the content of the flash (destination) is compared
3889 against the source after the write operation. An error message
3890 will be printed when the contents are not identical.
3891 Please note that this option is useless in nearly all cases,
3892 since such flash programming errors usually are detected earlier
3893 while unprotecting/erasing/programming. Please only enable
3894 this option if you really know what you are doing.
3896 - CONFIG_SYS_RX_ETH_BUFFER:
3897 Defines the number of Ethernet receive buffers. On some
3898 Ethernet controllers it is recommended to set this value
3899 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3900 buffers can be full shortly after enabling the interface
3901 on high Ethernet traffic.
3902 Defaults to 4 if not defined.
3904 - CONFIG_ENV_MAX_ENTRIES
3906 Maximum number of entries in the hash table that is used
3907 internally to store the environment settings. The default
3908 setting is supposed to be generous and should work in most
3909 cases. This setting can be used to tune behaviour; see
3910 lib/hashtable.c for details.
3912 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3913 - CONFIG_ENV_FLAGS_LIST_STATIC
3914 Enable validation of the values given to environment variables when
3915 calling env set. Variables can be restricted to only decimal,
3916 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3917 the variables can also be restricted to IP address or MAC address.
3919 The format of the list is:
3920 type_attribute = [s|d|x|b|i|m]
3921 access_attribute = [a|r|o|c]
3922 attributes = type_attribute[access_attribute]
3923 entry = variable_name[:attributes]
3926 The type attributes are:
3927 s - String (default)
3930 b - Boolean ([1yYtT|0nNfF])
3934 The access attributes are:
3940 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3941 Define this to a list (string) to define the ".flags"
3942 environment variable in the default or embedded environment.
3944 - CONFIG_ENV_FLAGS_LIST_STATIC
3945 Define this to a list (string) to define validation that
3946 should be done if an entry is not found in the ".flags"
3947 environment variable. To override a setting in the static
3948 list, simply add an entry for the same variable name to the
3951 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3952 regular expression. This allows multiple variables to define the same
3953 flags without explicitly listing them for each variable.
3955 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3956 If defined, don't allow the -f switch to env set override variable
3959 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3960 This is set by OMAP boards for the max time that reset should
3961 be asserted. See doc/README.omap-reset-time for details on how
3962 the value can be calculated on a given board.
3965 If stdint.h is available with your toolchain you can define this
3966 option to enable it. You can provide option 'USE_STDINT=1' when
3967 building U-Boot to enable this.
3969 The following definitions that deal with the placement and management
3970 of environment data (variable area); in general, we support the
3971 following configurations:
3973 - CONFIG_BUILD_ENVCRC:
3975 Builds up envcrc with the target environment so that external utils
3976 may easily extract it and embed it in final U-Boot images.
3978 - CONFIG_ENV_IS_IN_FLASH:
3980 Define this if the environment is in flash memory.
3982 a) The environment occupies one whole flash sector, which is
3983 "embedded" in the text segment with the U-Boot code. This
3984 happens usually with "bottom boot sector" or "top boot
3985 sector" type flash chips, which have several smaller
3986 sectors at the start or the end. For instance, such a
3987 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3988 such a case you would place the environment in one of the
3989 4 kB sectors - with U-Boot code before and after it. With
3990 "top boot sector" type flash chips, you would put the
3991 environment in one of the last sectors, leaving a gap
3992 between U-Boot and the environment.
3994 - CONFIG_ENV_OFFSET:
3996 Offset of environment data (variable area) to the
3997 beginning of flash memory; for instance, with bottom boot
3998 type flash chips the second sector can be used: the offset
3999 for this sector is given here.
4001 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
4005 This is just another way to specify the start address of
4006 the flash sector containing the environment (instead of
4009 - CONFIG_ENV_SECT_SIZE:
4011 Size of the sector containing the environment.
4014 b) Sometimes flash chips have few, equal sized, BIG sectors.
4015 In such a case you don't want to spend a whole sector for
4020 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4021 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4022 of this flash sector for the environment. This saves
4023 memory for the RAM copy of the environment.
4025 It may also save flash memory if you decide to use this
4026 when your environment is "embedded" within U-Boot code,
4027 since then the remainder of the flash sector could be used
4028 for U-Boot code. It should be pointed out that this is
4029 STRONGLY DISCOURAGED from a robustness point of view:
4030 updating the environment in flash makes it always
4031 necessary to erase the WHOLE sector. If something goes
4032 wrong before the contents has been restored from a copy in
4033 RAM, your target system will be dead.
4035 - CONFIG_ENV_ADDR_REDUND
4036 CONFIG_ENV_SIZE_REDUND
4038 These settings describe a second storage area used to hold
4039 a redundant copy of the environment data, so that there is
4040 a valid backup copy in case there is a power failure during
4041 a "saveenv" operation.
4043 BE CAREFUL! Any changes to the flash layout, and some changes to the
4044 source code will make it necessary to adapt <board>/u-boot.lds*
4048 - CONFIG_ENV_IS_IN_NVRAM:
4050 Define this if you have some non-volatile memory device
4051 (NVRAM, battery buffered SRAM) which you want to use for the
4057 These two #defines are used to determine the memory area you
4058 want to use for environment. It is assumed that this memory
4059 can just be read and written to, without any special
4062 BE CAREFUL! The first access to the environment happens quite early
4063 in U-Boot initialization (when we try to get the setting of for the
4064 console baudrate). You *MUST* have mapped your NVRAM area then, or
4067 Please note that even with NVRAM we still use a copy of the
4068 environment in RAM: we could work on NVRAM directly, but we want to
4069 keep settings there always unmodified except somebody uses "saveenv"
4070 to save the current settings.
4073 - CONFIG_ENV_IS_IN_EEPROM:
4075 Use this if you have an EEPROM or similar serial access
4076 device and a driver for it.
4078 - CONFIG_ENV_OFFSET:
4081 These two #defines specify the offset and size of the
4082 environment area within the total memory of your EEPROM.
4084 - CONFIG_SYS_I2C_EEPROM_ADDR:
4085 If defined, specified the chip address of the EEPROM device.
4086 The default address is zero.
4088 - CONFIG_SYS_I2C_EEPROM_BUS:
4089 If defined, specified the i2c bus of the EEPROM device.
4091 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4092 If defined, the number of bits used to address bytes in a
4093 single page in the EEPROM device. A 64 byte page, for example
4094 would require six bits.
4096 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4097 If defined, the number of milliseconds to delay between
4098 page writes. The default is zero milliseconds.
4100 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4101 The length in bytes of the EEPROM memory array address. Note
4102 that this is NOT the chip address length!
4104 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4105 EEPROM chips that implement "address overflow" are ones
4106 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4107 address and the extra bits end up in the "chip address" bit
4108 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4111 Note that we consider the length of the address field to
4112 still be one byte because the extra address bits are hidden
4113 in the chip address.
4115 - CONFIG_SYS_EEPROM_SIZE:
4116 The size in bytes of the EEPROM device.
4118 - CONFIG_ENV_EEPROM_IS_ON_I2C
4119 define this, if you have I2C and SPI activated, and your
4120 EEPROM, which holds the environment, is on the I2C bus.
4122 - CONFIG_I2C_ENV_EEPROM_BUS
4123 if you have an Environment on an EEPROM reached over
4124 I2C muxes, you can define here, how to reach this
4125 EEPROM. For example:
4127 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4129 EEPROM which holds the environment, is reached over
4130 a pca9547 i2c mux with address 0x70, channel 3.
4132 - CONFIG_ENV_IS_IN_DATAFLASH:
4134 Define this if you have a DataFlash memory device which you
4135 want to use for the environment.
4137 - CONFIG_ENV_OFFSET:
4141 These three #defines specify the offset and size of the
4142 environment area within the total memory of your DataFlash placed
4143 at the specified address.
4145 - CONFIG_ENV_IS_IN_SPI_FLASH:
4147 Define this if you have a SPI Flash memory device which you
4148 want to use for the environment.
4150 - CONFIG_ENV_OFFSET:
4153 These two #defines specify the offset and size of the
4154 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4155 aligned to an erase sector boundary.
4157 - CONFIG_ENV_SECT_SIZE:
4159 Define the SPI flash's sector size.
4161 - CONFIG_ENV_OFFSET_REDUND (optional):
4163 This setting describes a second storage area of CONFIG_ENV_SIZE
4164 size used to hold a redundant copy of the environment data, so
4165 that there is a valid backup copy in case there is a power failure
4166 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4167 aligned to an erase sector boundary.
4169 - CONFIG_ENV_SPI_BUS (optional):
4170 - CONFIG_ENV_SPI_CS (optional):
4172 Define the SPI bus and chip select. If not defined they will be 0.
4174 - CONFIG_ENV_SPI_MAX_HZ (optional):
4176 Define the SPI max work clock. If not defined then use 1MHz.
4178 - CONFIG_ENV_SPI_MODE (optional):
4180 Define the SPI work mode. If not defined then use SPI_MODE_3.
4182 - CONFIG_ENV_IS_IN_REMOTE:
4184 Define this if you have a remote memory space which you
4185 want to use for the local device's environment.
4190 These two #defines specify the address and size of the
4191 environment area within the remote memory space. The
4192 local device can get the environment from remote memory
4193 space by SRIO or PCIE links.
4195 BE CAREFUL! For some special cases, the local device can not use
4196 "saveenv" command. For example, the local device will get the
4197 environment stored in a remote NOR flash by SRIO or PCIE link,
4198 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4200 - CONFIG_ENV_IS_IN_NAND:
4202 Define this if you have a NAND device which you want to use
4203 for the environment.
4205 - CONFIG_ENV_OFFSET:
4208 These two #defines specify the offset and size of the environment
4209 area within the first NAND device. CONFIG_ENV_OFFSET must be
4210 aligned to an erase block boundary.
4212 - CONFIG_ENV_OFFSET_REDUND (optional):
4214 This setting describes a second storage area of CONFIG_ENV_SIZE
4215 size used to hold a redundant copy of the environment data, so
4216 that there is a valid backup copy in case there is a power failure
4217 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4218 aligned to an erase block boundary.
4220 - CONFIG_ENV_RANGE (optional):
4222 Specifies the length of the region in which the environment
4223 can be written. This should be a multiple of the NAND device's
4224 block size. Specifying a range with more erase blocks than
4225 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4226 the range to be avoided.
4228 - CONFIG_ENV_OFFSET_OOB (optional):
4230 Enables support for dynamically retrieving the offset of the
4231 environment from block zero's out-of-band data. The
4232 "nand env.oob" command can be used to record this offset.
4233 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4234 using CONFIG_ENV_OFFSET_OOB.
4236 - CONFIG_NAND_ENV_DST
4238 Defines address in RAM to which the nand_spl code should copy the
4239 environment. If redundant environment is used, it will be copied to
4240 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4242 - CONFIG_ENV_IS_IN_UBI:
4244 Define this if you have an UBI volume that you want to use for the
4245 environment. This has the benefit of wear-leveling the environment
4246 accesses, which is important on NAND.
4248 - CONFIG_ENV_UBI_PART:
4250 Define this to a string that is the mtd partition containing the UBI.
4252 - CONFIG_ENV_UBI_VOLUME:
4254 Define this to the name of the volume that you want to store the
4257 - CONFIG_ENV_UBI_VOLUME_REDUND:
4259 Define this to the name of another volume to store a second copy of
4260 the environment in. This will enable redundant environments in UBI.
4261 It is assumed that both volumes are in the same MTD partition.
4263 - CONFIG_UBI_SILENCE_MSG
4264 - CONFIG_UBIFS_SILENCE_MSG
4266 You will probably want to define these to avoid a really noisy system
4267 when storing the env in UBI.
4269 - CONFIG_ENV_IS_IN_FAT:
4270 Define this if you want to use the FAT file system for the environment.
4272 - FAT_ENV_INTERFACE:
4274 Define this to a string that is the name of the block device.
4276 - FAT_ENV_DEV_AND_PART:
4278 Define this to a string to specify the partition of the device. It can
4281 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4282 - "D:P": device D partition P. Error occurs if device D has no
4285 - "D" or "D:": device D partition 1 if device D has partition
4286 table, or the whole device D if has no partition
4288 - "D:auto": first partition in device D with bootable flag set.
4289 If none, first valid partition in device D. If no
4290 partition table then means device D.
4294 It's a string of the FAT file name. This file use to store the
4298 This should be defined. Otherwise it cannot save the environment file.
4300 - CONFIG_ENV_IS_IN_MMC:
4302 Define this if you have an MMC device which you want to use for the
4305 - CONFIG_SYS_MMC_ENV_DEV:
4307 Specifies which MMC device the environment is stored in.
4309 - CONFIG_SYS_MMC_ENV_PART (optional):
4311 Specifies which MMC partition the environment is stored in. If not
4312 set, defaults to partition 0, the user area. Common values might be
4313 1 (first MMC boot partition), 2 (second MMC boot partition).
4315 - CONFIG_ENV_OFFSET:
4318 These two #defines specify the offset and size of the environment
4319 area within the specified MMC device.
4321 If offset is positive (the usual case), it is treated as relative to
4322 the start of the MMC partition. If offset is negative, it is treated
4323 as relative to the end of the MMC partition. This can be useful if
4324 your board may be fitted with different MMC devices, which have
4325 different sizes for the MMC partitions, and you always want the
4326 environment placed at the very end of the partition, to leave the
4327 maximum possible space before it, to store other data.
4329 These two values are in units of bytes, but must be aligned to an
4330 MMC sector boundary.
4332 - CONFIG_ENV_OFFSET_REDUND (optional):
4334 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4335 hold a redundant copy of the environment data. This provides a
4336 valid backup copy in case the other copy is corrupted, e.g. due
4337 to a power failure during a "saveenv" operation.
4339 This value may also be positive or negative; this is handled in the
4340 same way as CONFIG_ENV_OFFSET.
4342 This value is also in units of bytes, but must also be aligned to
4343 an MMC sector boundary.
4345 - CONFIG_ENV_SIZE_REDUND (optional):
4347 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4348 set. If this value is set, it must be set to the same value as
4351 - CONFIG_SYS_SPI_INIT_OFFSET
4353 Defines offset to the initial SPI buffer area in DPRAM. The
4354 area is used at an early stage (ROM part) if the environment
4355 is configured to reside in the SPI EEPROM: We need a 520 byte
4356 scratch DPRAM area. It is used between the two initialization
4357 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4358 to be a good choice since it makes it far enough from the
4359 start of the data area as well as from the stack pointer.
4361 Please note that the environment is read-only until the monitor
4362 has been relocated to RAM and a RAM copy of the environment has been
4363 created; also, when using EEPROM you will have to use getenv_f()
4364 until then to read environment variables.
4366 The environment is protected by a CRC32 checksum. Before the monitor
4367 is relocated into RAM, as a result of a bad CRC you will be working
4368 with the compiled-in default environment - *silently*!!! [This is
4369 necessary, because the first environment variable we need is the
4370 "baudrate" setting for the console - if we have a bad CRC, we don't
4371 have any device yet where we could complain.]
4373 Note: once the monitor has been relocated, then it will complain if
4374 the default environment is used; a new CRC is computed as soon as you
4375 use the "saveenv" command to store a valid environment.
4377 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4378 Echo the inverted Ethernet link state to the fault LED.
4380 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4381 also needs to be defined.
4383 - CONFIG_SYS_FAULT_MII_ADDR:
4384 MII address of the PHY to check for the Ethernet link state.
4386 - CONFIG_NS16550_MIN_FUNCTIONS:
4387 Define this if you desire to only have use of the NS16550_init
4388 and NS16550_putc functions for the serial driver located at
4389 drivers/serial/ns16550.c. This option is useful for saving
4390 space for already greatly restricted images, including but not
4391 limited to NAND_SPL configurations.
4393 - CONFIG_DISPLAY_BOARDINFO
4394 Display information about the board that U-Boot is running on
4395 when U-Boot starts up. The board function checkboard() is called
4398 - CONFIG_DISPLAY_BOARDINFO_LATE
4399 Similar to the previous option, but display this information
4400 later, once stdio is running and output goes to the LCD, if
4403 - CONFIG_BOARD_SIZE_LIMIT:
4404 Maximum size of the U-Boot image. When defined, the
4405 build system checks that the actual size does not
4408 Low Level (hardware related) configuration options:
4409 ---------------------------------------------------
4411 - CONFIG_SYS_CACHELINE_SIZE:
4412 Cache Line Size of the CPU.
4414 - CONFIG_SYS_DEFAULT_IMMR:
4415 Default address of the IMMR after system reset.
4417 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4418 and RPXsuper) to be able to adjust the position of
4419 the IMMR register after a reset.
4421 - CONFIG_SYS_CCSRBAR_DEFAULT:
4422 Default (power-on reset) physical address of CCSR on Freescale
4425 - CONFIG_SYS_CCSRBAR:
4426 Virtual address of CCSR. On a 32-bit build, this is typically
4427 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4429 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4430 for cross-platform code that uses that macro instead.
4432 - CONFIG_SYS_CCSRBAR_PHYS:
4433 Physical address of CCSR. CCSR can be relocated to a new
4434 physical address, if desired. In this case, this macro should
4435 be set to that address. Otherwise, it should be set to the
4436 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4437 is typically relocated on 36-bit builds. It is recommended
4438 that this macro be defined via the _HIGH and _LOW macros:
4440 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4441 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4443 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4444 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4445 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4446 used in assembly code, so it must not contain typecasts or
4447 integer size suffixes (e.g. "ULL").
4449 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4450 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4451 used in assembly code, so it must not contain typecasts or
4452 integer size suffixes (e.g. "ULL").
4454 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4455 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4456 forced to a value that ensures that CCSR is not relocated.
4458 - Floppy Disk Support:
4459 CONFIG_SYS_FDC_DRIVE_NUMBER
4461 the default drive number (default value 0)
4463 CONFIG_SYS_ISA_IO_STRIDE
4465 defines the spacing between FDC chipset registers
4468 CONFIG_SYS_ISA_IO_OFFSET
4470 defines the offset of register from address. It
4471 depends on which part of the data bus is connected to
4472 the FDC chipset. (default value 0)
4474 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4475 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4478 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4479 fdc_hw_init() is called at the beginning of the FDC
4480 setup. fdc_hw_init() must be provided by the board
4481 source code. It is used to make hardware-dependent
4485 Most IDE controllers were designed to be connected with PCI
4486 interface. Only few of them were designed for AHB interface.
4487 When software is doing ATA command and data transfer to
4488 IDE devices through IDE-AHB controller, some additional
4489 registers accessing to these kind of IDE-AHB controller
4492 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4493 DO NOT CHANGE unless you know exactly what you're
4494 doing! (11-4) [MPC8xx/82xx systems only]
4496 - CONFIG_SYS_INIT_RAM_ADDR:
4498 Start address of memory area that can be used for
4499 initial data and stack; please note that this must be
4500 writable memory that is working WITHOUT special
4501 initialization, i. e. you CANNOT use normal RAM which
4502 will become available only after programming the
4503 memory controller and running certain initialization
4506 U-Boot uses the following memory types:
4507 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4508 - MPC824X: data cache
4509 - PPC4xx: data cache
4511 - CONFIG_SYS_GBL_DATA_OFFSET:
4513 Offset of the initial data structure in the memory
4514 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4515 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4516 data is located at the end of the available space
4517 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4518 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4519 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4520 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4523 On the MPC824X (or other systems that use the data
4524 cache for initial memory) the address chosen for
4525 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4526 point to an otherwise UNUSED address space between
4527 the top of RAM and the start of the PCI space.
4529 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4531 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4533 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4535 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4537 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4539 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4541 - CONFIG_SYS_OR_TIMING_SDRAM:
4544 - CONFIG_SYS_MAMR_PTA:
4545 periodic timer for refresh
4547 - CONFIG_SYS_DER: Debug Event Register (37-47)
4549 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4550 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4551 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4552 CONFIG_SYS_BR1_PRELIM:
4553 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4555 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4556 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4557 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4558 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4560 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4561 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4562 Machine Mode Register and Memory Periodic Timer
4563 Prescaler definitions (SDRAM timing)
4565 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4566 enable I2C microcode relocation patch (MPC8xx);
4567 define relocation offset in DPRAM [DSP2]
4569 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4570 enable SMC microcode relocation patch (MPC8xx);
4571 define relocation offset in DPRAM [SMC1]
4573 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4574 enable SPI microcode relocation patch (MPC8xx);
4575 define relocation offset in DPRAM [SCC4]
4577 - CONFIG_SYS_USE_OSCCLK:
4578 Use OSCM clock mode on MBX8xx board. Be careful,
4579 wrong setting might damage your board. Read
4580 doc/README.MBX before setting this variable!
4582 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4583 Offset of the bootmode word in DPRAM used by post
4584 (Power On Self Tests). This definition overrides
4585 #define'd default value in commproc.h resp.
4588 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4589 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4590 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4591 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4592 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4593 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4594 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4595 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4596 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4598 - CONFIG_PCI_DISABLE_PCIE:
4599 Disable PCI-Express on systems where it is supported but not
4602 - CONFIG_PCI_ENUM_ONLY
4603 Only scan through and get the devices on the buses.
4604 Don't do any setup work, presumably because someone or
4605 something has already done it, and we don't need to do it
4606 a second time. Useful for platforms that are pre-booted
4607 by coreboot or similar.
4609 - CONFIG_PCI_INDIRECT_BRIDGE:
4610 Enable support for indirect PCI bridges.
4613 Chip has SRIO or not
4616 Board has SRIO 1 port available
4619 Board has SRIO 2 port available
4621 - CONFIG_SRIO_PCIE_BOOT_MASTER
4622 Board can support master function for Boot from SRIO and PCIE
4624 - CONFIG_SYS_SRIOn_MEM_VIRT:
4625 Virtual Address of SRIO port 'n' memory region
4627 - CONFIG_SYS_SRIOn_MEM_PHYS:
4628 Physical Address of SRIO port 'n' memory region
4630 - CONFIG_SYS_SRIOn_MEM_SIZE:
4631 Size of SRIO port 'n' memory region
4633 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4634 Defined to tell the NAND controller that the NAND chip is using
4636 Not all NAND drivers use this symbol.
4637 Example of drivers that use it:
4638 - drivers/mtd/nand/ndfc.c
4639 - drivers/mtd/nand/mxc_nand.c
4641 - CONFIG_SYS_NDFC_EBC0_CFG
4642 Sets the EBC0_CFG register for the NDFC. If not defined
4643 a default value will be used.
4646 Get DDR timing information from an I2C EEPROM. Common
4647 with pluggable memory modules such as SODIMMs
4650 I2C address of the SPD EEPROM
4652 - CONFIG_SYS_SPD_BUS_NUM
4653 If SPD EEPROM is on an I2C bus other than the first
4654 one, specify here. Note that the value must resolve
4655 to something your driver can deal with.
4657 - CONFIG_SYS_DDR_RAW_TIMING
4658 Get DDR timing information from other than SPD. Common with
4659 soldered DDR chips onboard without SPD. DDR raw timing
4660 parameters are extracted from datasheet and hard-coded into
4661 header files or board specific files.
4663 - CONFIG_FSL_DDR_INTERACTIVE
4664 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4666 - CONFIG_FSL_DDR_SYNC_REFRESH
4667 Enable sync of refresh for multiple controllers.
4669 - CONFIG_FSL_DDR_BIST
4670 Enable built-in memory test for Freescale DDR controllers.
4672 - CONFIG_SYS_83XX_DDR_USES_CS0
4673 Only for 83xx systems. If specified, then DDR should
4674 be configured using CS0 and CS1 instead of CS2 and CS3.
4676 - CONFIG_ETHER_ON_FEC[12]
4677 Define to enable FEC[12] on a 8xx series processor.
4679 - CONFIG_FEC[12]_PHY
4680 Define to the hardcoded PHY address which corresponds
4681 to the given FEC; i. e.
4682 #define CONFIG_FEC1_PHY 4
4683 means that the PHY with address 4 is connected to FEC1
4685 When set to -1, means to probe for first available.
4687 - CONFIG_FEC[12]_PHY_NORXERR
4688 The PHY does not have a RXERR line (RMII only).
4689 (so program the FEC to ignore it).
4692 Enable RMII mode for all FECs.
4693 Note that this is a global option, we can't
4694 have one FEC in standard MII mode and another in RMII mode.
4696 - CONFIG_CRC32_VERIFY
4697 Add a verify option to the crc32 command.
4700 => crc32 -v <address> <count> <crc32>
4702 Where address/count indicate a memory area
4703 and crc32 is the correct crc32 which the
4707 Add the "loopw" memory command. This only takes effect if
4708 the memory commands are activated globally (CONFIG_CMD_MEM).
4711 Add the "mdc" and "mwc" memory commands. These are cyclic
4716 This command will print 4 bytes (10,11,12,13) each 500 ms.
4718 => mwc.l 100 12345678 10
4719 This command will write 12345678 to address 100 all 10 ms.
4721 This only takes effect if the memory commands are activated
4722 globally (CONFIG_CMD_MEM).
4724 - CONFIG_SKIP_LOWLEVEL_INIT
4725 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4726 low level initializations (like setting up the memory
4727 controller) are omitted and/or U-Boot does not
4728 relocate itself into RAM.
4730 Normally this variable MUST NOT be defined. The only
4731 exception is when U-Boot is loaded (to RAM) by some
4732 other boot loader or by a debugger which performs
4733 these initializations itself.
4735 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4736 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4737 to be skipped. The normal CP15 init (such as enabling the
4738 instruction cache) is still performed.
4741 Modifies the behaviour of start.S when compiling a loader
4742 that is executed before the actual U-Boot. E.g. when
4743 compiling a NAND SPL.
4746 Modifies the behaviour of start.S when compiling a loader
4747 that is executed after the SPL and before the actual U-Boot.
4748 It is loaded by the SPL.
4750 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4751 Only for 85xx systems. If this variable is specified, the section
4752 .resetvec is not kept and the section .bootpg is placed in the
4753 previous 4k of the .text section.
4755 - CONFIG_ARCH_MAP_SYSMEM
4756 Generally U-Boot (and in particular the md command) uses
4757 effective address. It is therefore not necessary to regard
4758 U-Boot address as virtual addresses that need to be translated
4759 to physical addresses. However, sandbox requires this, since
4760 it maintains its own little RAM buffer which contains all
4761 addressable memory. This option causes some memory accesses
4762 to be mapped through map_sysmem() / unmap_sysmem().
4764 - CONFIG_USE_ARCH_MEMCPY
4765 CONFIG_USE_ARCH_MEMSET
4766 If these options are used a optimized version of memcpy/memset will
4767 be used if available. These functions may be faster under some
4768 conditions but may increase the binary size.
4770 - CONFIG_X86_RESET_VECTOR
4771 If defined, the x86 reset vector code is included. This is not
4772 needed when U-Boot is running from Coreboot.
4775 Defines the MPU clock speed (in MHz).
4777 NOTE : currently only supported on AM335x platforms.
4779 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4780 Enables the RTC32K OSC on AM33xx based plattforms
4782 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4783 Option to disable subpage write in NAND driver
4784 driver that uses this:
4785 drivers/mtd/nand/davinci_nand.c
4787 Freescale QE/FMAN Firmware Support:
4788 -----------------------------------
4790 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4791 loading of "firmware", which is encoded in the QE firmware binary format.
4792 This firmware often needs to be loaded during U-Boot booting, so macros
4793 are used to identify the storage device (NOR flash, SPI, etc) and the address
4796 - CONFIG_SYS_FMAN_FW_ADDR
4797 The address in the storage device where the FMAN microcode is located. The
4798 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4801 - CONFIG_SYS_QE_FW_ADDR
4802 The address in the storage device where the QE microcode is located. The
4803 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4806 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4807 The maximum possible size of the firmware. The firmware binary format
4808 has a field that specifies the actual size of the firmware, but it
4809 might not be possible to read any part of the firmware unless some
4810 local storage is allocated to hold the entire firmware first.
4812 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4813 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4814 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4815 virtual address in NOR flash.
4817 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4818 Specifies that QE/FMAN firmware is located in NAND flash.
4819 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4821 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4822 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4823 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4825 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4826 Specifies that QE/FMAN firmware is located on the primary SPI
4827 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4829 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4830 Specifies that QE/FMAN firmware is located in the remote (master)
4831 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4832 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4833 window->master inbound window->master LAW->the ucode address in
4834 master's memory space.
4836 Freescale Layerscape Management Complex Firmware Support:
4837 ---------------------------------------------------------
4838 The Freescale Layerscape Management Complex (MC) supports the loading of
4840 This firmware often needs to be loaded during U-Boot booting, so macros
4841 are used to identify the storage device (NOR flash, SPI, etc) and the address
4844 - CONFIG_FSL_MC_ENET
4845 Enable the MC driver for Layerscape SoCs.
4847 - CONFIG_SYS_LS_MC_FW_ADDR
4848 The address in the storage device where the firmware is located. The
4849 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4852 - CONFIG_SYS_LS_MC_FW_LENGTH
4853 The maximum possible size of the firmware. The firmware binary format
4854 has a field that specifies the actual size of the firmware, but it
4855 might not be possible to read any part of the firmware unless some
4856 local storage is allocated to hold the entire firmware first.
4858 - CONFIG_SYS_LS_MC_FW_IN_NOR
4859 Specifies that MC firmware is located in NOR flash, mapped as
4860 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4861 virtual address in NOR flash.
4863 Freescale Layerscape Debug Server Support:
4864 -------------------------------------------
4865 The Freescale Layerscape Debug Server Support supports the loading of
4866 "Debug Server firmware" and triggering SP boot-rom.
4867 This firmware often needs to be loaded during U-Boot booting.
4869 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4870 Define alignment of reserved memory MC requires
4875 In order to achieve reproducible builds, timestamps used in the U-Boot build
4876 process have to be set to a fixed value.
4878 This is done using the SOURCE_DATE_EPOCH environment variable.
4879 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4880 option for U-Boot or an environment variable in U-Boot.
4882 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4884 Building the Software:
4885 ======================
4887 Building U-Boot has been tested in several native build environments
4888 and in many different cross environments. Of course we cannot support
4889 all possibly existing versions of cross development tools in all
4890 (potentially obsolete) versions. In case of tool chain problems we
4891 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4892 which is extensively used to build and test U-Boot.
4894 If you are not using a native environment, it is assumed that you
4895 have GNU cross compiling tools available in your path. In this case,
4896 you must set the environment variable CROSS_COMPILE in your shell.
4897 Note that no changes to the Makefile or any other source files are
4898 necessary. For example using the ELDK on a 4xx CPU, please enter:
4900 $ CROSS_COMPILE=ppc_4xx-
4901 $ export CROSS_COMPILE
4903 Note: If you wish to generate Windows versions of the utilities in
4904 the tools directory you can use the MinGW toolchain
4905 (http://www.mingw.org). Set your HOST tools to the MinGW
4906 toolchain and execute 'make tools'. For example:
4908 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4910 Binaries such as tools/mkimage.exe will be created which can
4911 be executed on computers running Windows.
4913 U-Boot is intended to be simple to build. After installing the
4914 sources you must configure U-Boot for one specific board type. This
4919 where "NAME_defconfig" is the name of one of the existing configu-
4920 rations; see boards.cfg for supported names.
4922 Note: for some board special configuration names may exist; check if
4923 additional information is available from the board vendor; for
4924 instance, the TQM823L systems are available without (standard)
4925 or with LCD support. You can select such additional "features"
4926 when choosing the configuration, i. e.
4928 make TQM823L_defconfig
4929 - will configure for a plain TQM823L, i. e. no LCD support
4931 make TQM823L_LCD_defconfig
4932 - will configure for a TQM823L with U-Boot console on LCD
4937 Finally, type "make all", and you should get some working U-Boot
4938 images ready for download to / installation on your system:
4940 - "u-boot.bin" is a raw binary image
4941 - "u-boot" is an image in ELF binary format
4942 - "u-boot.srec" is in Motorola S-Record format
4944 By default the build is performed locally and the objects are saved
4945 in the source directory. One of the two methods can be used to change
4946 this behavior and build U-Boot to some external directory:
4948 1. Add O= to the make command line invocations:
4950 make O=/tmp/build distclean
4951 make O=/tmp/build NAME_defconfig
4952 make O=/tmp/build all
4954 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4956 export KBUILD_OUTPUT=/tmp/build
4961 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4965 Please be aware that the Makefiles assume you are using GNU make, so
4966 for instance on NetBSD you might need to use "gmake" instead of
4970 If the system board that you have is not listed, then you will need
4971 to port U-Boot to your hardware platform. To do this, follow these
4974 1. Create a new directory to hold your board specific code. Add any
4975 files you need. In your board directory, you will need at least
4976 the "Makefile" and a "<board>.c".
4977 2. Create a new configuration file "include/configs/<board>.h" for
4979 3. If you're porting U-Boot to a new CPU, then also create a new
4980 directory to hold your CPU specific code. Add any files you need.
4981 4. Run "make <board>_defconfig" with your new name.
4982 5. Type "make", and you should get a working "u-boot.srec" file
4983 to be installed on your target system.
4984 6. Debug and solve any problems that might arise.
4985 [Of course, this last step is much harder than it sounds.]
4988 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4989 ==============================================================
4991 If you have modified U-Boot sources (for instance added a new board
4992 or support for new devices, a new CPU, etc.) you are expected to
4993 provide feedback to the other developers. The feedback normally takes
4994 the form of a "patch", i. e. a context diff against a certain (latest
4995 official or latest in the git repository) version of U-Boot sources.
4997 But before you submit such a patch, please verify that your modifi-
4998 cation did not break existing code. At least make sure that *ALL* of
4999 the supported boards compile WITHOUT ANY compiler warnings. To do so,
5000 just run the buildman script (tools/buildman/buildman), which will
5001 configure and build U-Boot for ALL supported system. Be warned, this
5002 will take a while. Please see the buildman README, or run 'buildman -H'
5006 See also "U-Boot Porting Guide" below.
5009 Monitor Commands - Overview:
5010 ============================
5012 go - start application at address 'addr'
5013 run - run commands in an environment variable
5014 bootm - boot application image from memory
5015 bootp - boot image via network using BootP/TFTP protocol
5016 bootz - boot zImage from memory
5017 tftpboot- boot image via network using TFTP protocol
5018 and env variables "ipaddr" and "serverip"
5019 (and eventually "gatewayip")
5020 tftpput - upload a file via network using TFTP protocol
5021 rarpboot- boot image via network using RARP/TFTP protocol
5022 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5023 loads - load S-Record file over serial line
5024 loadb - load binary file over serial line (kermit mode)
5026 mm - memory modify (auto-incrementing)
5027 nm - memory modify (constant address)
5028 mw - memory write (fill)
5030 cmp - memory compare
5031 crc32 - checksum calculation
5032 i2c - I2C sub-system
5033 sspi - SPI utility commands
5034 base - print or set address offset
5035 printenv- print environment variables
5036 setenv - set environment variables
5037 saveenv - save environment variables to persistent storage
5038 protect - enable or disable FLASH write protection
5039 erase - erase FLASH memory
5040 flinfo - print FLASH memory information
5041 nand - NAND memory operations (see doc/README.nand)
5042 bdinfo - print Board Info structure
5043 iminfo - print header information for application image
5044 coninfo - print console devices and informations
5045 ide - IDE sub-system
5046 loop - infinite loop on address range
5047 loopw - infinite write loop on address range
5048 mtest - simple RAM test
5049 icache - enable or disable instruction cache
5050 dcache - enable or disable data cache
5051 reset - Perform RESET of the CPU
5052 echo - echo args to console
5053 version - print monitor version
5054 help - print online help
5055 ? - alias for 'help'
5058 Monitor Commands - Detailed Description:
5059 ========================================
5063 For now: just type "help <command>".
5066 Environment Variables:
5067 ======================
5069 U-Boot supports user configuration using Environment Variables which
5070 can be made persistent by saving to Flash memory.
5072 Environment Variables are set using "setenv", printed using
5073 "printenv", and saved to Flash using "saveenv". Using "setenv"
5074 without a value can be used to delete a variable from the
5075 environment. As long as you don't save the environment you are
5076 working with an in-memory copy. In case the Flash area containing the
5077 environment is erased by accident, a default environment is provided.
5079 Some configuration options can be set using Environment Variables.
5081 List of environment variables (most likely not complete):
5083 baudrate - see CONFIG_BAUDRATE
5085 bootdelay - see CONFIG_BOOTDELAY
5087 bootcmd - see CONFIG_BOOTCOMMAND
5089 bootargs - Boot arguments when booting an RTOS image
5091 bootfile - Name of the image to load with TFTP
5093 bootm_low - Memory range available for image processing in the bootm
5094 command can be restricted. This variable is given as
5095 a hexadecimal number and defines lowest address allowed
5096 for use by the bootm command. See also "bootm_size"
5097 environment variable. Address defined by "bootm_low" is
5098 also the base of the initial memory mapping for the Linux
5099 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5102 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5103 This variable is given as a hexadecimal number and it
5104 defines the size of the memory region starting at base
5105 address bootm_low that is accessible by the Linux kernel
5106 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5107 as the default value if it is defined, and bootm_size is
5110 bootm_size - Memory range available for image processing in the bootm
5111 command can be restricted. This variable is given as
5112 a hexadecimal number and defines the size of the region
5113 allowed for use by the bootm command. See also "bootm_low"
5114 environment variable.
5116 updatefile - Location of the software update file on a TFTP server, used
5117 by the automatic software update feature. Please refer to
5118 documentation in doc/README.update for more details.
5120 autoload - if set to "no" (any string beginning with 'n'),
5121 "bootp" will just load perform a lookup of the
5122 configuration from the BOOTP server, but not try to
5123 load any image using TFTP
5125 autostart - if set to "yes", an image loaded using the "bootp",
5126 "rarpboot", "tftpboot" or "diskboot" commands will
5127 be automatically started (by internally calling
5130 If set to "no", a standalone image passed to the
5131 "bootm" command will be copied to the load address
5132 (and eventually uncompressed), but NOT be started.
5133 This can be used to load and uncompress arbitrary
5136 fdt_high - if set this restricts the maximum address that the
5137 flattened device tree will be copied into upon boot.
5138 For example, if you have a system with 1 GB memory
5139 at physical address 0x10000000, while Linux kernel
5140 only recognizes the first 704 MB as low memory, you
5141 may need to set fdt_high as 0x3C000000 to have the
5142 device tree blob be copied to the maximum address
5143 of the 704 MB low memory, so that Linux kernel can
5144 access it during the boot procedure.
5146 If this is set to the special value 0xFFFFFFFF then
5147 the fdt will not be copied at all on boot. For this
5148 to work it must reside in writable memory, have
5149 sufficient padding on the end of it for u-boot to
5150 add the information it needs into it, and the memory
5151 must be accessible by the kernel.
5153 fdtcontroladdr- if set this is the address of the control flattened
5154 device tree used by U-Boot when CONFIG_OF_CONTROL is
5157 i2cfast - (PPC405GP|PPC405EP only)
5158 if set to 'y' configures Linux I2C driver for fast
5159 mode (400kHZ). This environment variable is used in
5160 initialization code. So, for changes to be effective
5161 it must be saved and board must be reset.
5163 initrd_high - restrict positioning of initrd images:
5164 If this variable is not set, initrd images will be
5165 copied to the highest possible address in RAM; this
5166 is usually what you want since it allows for
5167 maximum initrd size. If for some reason you want to
5168 make sure that the initrd image is loaded below the
5169 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5170 variable to a value of "no" or "off" or "0".
5171 Alternatively, you can set it to a maximum upper
5172 address to use (U-Boot will still check that it
5173 does not overwrite the U-Boot stack and data).
5175 For instance, when you have a system with 16 MB
5176 RAM, and want to reserve 4 MB from use by Linux,
5177 you can do this by adding "mem=12M" to the value of
5178 the "bootargs" variable. However, now you must make
5179 sure that the initrd image is placed in the first
5180 12 MB as well - this can be done with
5182 setenv initrd_high 00c00000
5184 If you set initrd_high to 0xFFFFFFFF, this is an
5185 indication to U-Boot that all addresses are legal
5186 for the Linux kernel, including addresses in flash
5187 memory. In this case U-Boot will NOT COPY the
5188 ramdisk at all. This may be useful to reduce the
5189 boot time on your system, but requires that this
5190 feature is supported by your Linux kernel.
5192 ipaddr - IP address; needed for tftpboot command
5194 loadaddr - Default load address for commands like "bootp",
5195 "rarpboot", "tftpboot", "loadb" or "diskboot"
5197 loads_echo - see CONFIG_LOADS_ECHO
5199 serverip - TFTP server IP address; needed for tftpboot command
5201 bootretry - see CONFIG_BOOT_RETRY_TIME
5203 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5205 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5207 ethprime - controls which interface is used first.
5209 ethact - controls which interface is currently active.
5210 For example you can do the following
5212 => setenv ethact FEC
5213 => ping 192.168.0.1 # traffic sent on FEC
5214 => setenv ethact SCC
5215 => ping 10.0.0.1 # traffic sent on SCC
5217 ethrotate - When set to "no" U-Boot does not go through all
5218 available network interfaces.
5219 It just stays at the currently selected interface.
5221 netretry - When set to "no" each network operation will
5222 either succeed or fail without retrying.
5223 When set to "once" the network operation will
5224 fail when all the available network interfaces
5225 are tried once without success.
5226 Useful on scripts which control the retry operation
5229 npe_ucode - set load address for the NPE microcode
5231 silent_linux - If set then Linux will be told to boot silently, by
5232 changing the console to be empty. If "yes" it will be
5233 made silent. If "no" it will not be made silent. If
5234 unset, then it will be made silent if the U-Boot console
5237 tftpsrcp - If this is set, the value is used for TFTP's
5240 tftpdstp - If this is set, the value is used for TFTP's UDP
5241 destination port instead of the Well Know Port 69.
5243 tftpblocksize - Block size to use for TFTP transfers; if not set,
5244 we use the TFTP server's default block size
5246 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5247 seconds, minimum value is 1000 = 1 second). Defines
5248 when a packet is considered to be lost so it has to
5249 be retransmitted. The default is 5000 = 5 seconds.
5250 Lowering this value may make downloads succeed
5251 faster in networks with high packet loss rates or
5252 with unreliable TFTP servers.
5254 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5255 unit, minimum value = 0). Defines how many timeouts
5256 can happen during a single file transfer before that
5257 transfer is aborted. The default is 10, and 0 means
5258 'no timeouts allowed'. Increasing this value may help
5259 downloads succeed with high packet loss rates, or with
5260 unreliable TFTP servers or client hardware.
5262 vlan - When set to a value < 4095 the traffic over
5263 Ethernet is encapsulated/received over 802.1q
5266 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5267 Unsigned value, in milliseconds. If not set, the period will
5268 be either the default (28000), or a value based on
5269 CONFIG_NET_RETRY_COUNT, if defined. This value has
5270 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5272 The following image location variables contain the location of images
5273 used in booting. The "Image" column gives the role of the image and is
5274 not an environment variable name. The other columns are environment
5275 variable names. "File Name" gives the name of the file on a TFTP
5276 server, "RAM Address" gives the location in RAM the image will be
5277 loaded to, and "Flash Location" gives the image's address in NOR
5278 flash or offset in NAND flash.
5280 *Note* - these variables don't have to be defined for all boards, some
5281 boards currently use other variables for these purposes, and some
5282 boards use these variables for other purposes.
5284 Image File Name RAM Address Flash Location
5285 ----- --------- ----------- --------------
5286 u-boot u-boot u-boot_addr_r u-boot_addr
5287 Linux kernel bootfile kernel_addr_r kernel_addr
5288 device tree blob fdtfile fdt_addr_r fdt_addr
5289 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5291 The following environment variables may be used and automatically
5292 updated by the network boot commands ("bootp" and "rarpboot"),
5293 depending the information provided by your boot server:
5295 bootfile - see above
5296 dnsip - IP address of your Domain Name Server
5297 dnsip2 - IP address of your secondary Domain Name Server
5298 gatewayip - IP address of the Gateway (Router) to use
5299 hostname - Target hostname
5301 netmask - Subnet Mask
5302 rootpath - Pathname of the root filesystem on the NFS server
5303 serverip - see above
5306 There are two special Environment Variables:
5308 serial# - contains hardware identification information such
5309 as type string and/or serial number
5310 ethaddr - Ethernet address
5312 These variables can be set only once (usually during manufacturing of
5313 the board). U-Boot refuses to delete or overwrite these variables
5314 once they have been set once.
5317 Further special Environment Variables:
5319 ver - Contains the U-Boot version string as printed
5320 with the "version" command. This variable is
5321 readonly (see CONFIG_VERSION_VARIABLE).
5324 Please note that changes to some configuration parameters may take
5325 only effect after the next boot (yes, that's just like Windoze :-).
5328 Callback functions for environment variables:
5329 ---------------------------------------------
5331 For some environment variables, the behavior of u-boot needs to change
5332 when their values are changed. This functionality allows functions to
5333 be associated with arbitrary variables. On creation, overwrite, or
5334 deletion, the callback will provide the opportunity for some side
5335 effect to happen or for the change to be rejected.
5337 The callbacks are named and associated with a function using the
5338 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5340 These callbacks are associated with variables in one of two ways. The
5341 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5342 in the board configuration to a string that defines a list of
5343 associations. The list must be in the following format:
5345 entry = variable_name[:callback_name]
5348 If the callback name is not specified, then the callback is deleted.
5349 Spaces are also allowed anywhere in the list.
5351 Callbacks can also be associated by defining the ".callbacks" variable
5352 with the same list format above. Any association in ".callbacks" will
5353 override any association in the static list. You can define
5354 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5355 ".callbacks" environment variable in the default or embedded environment.
5357 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5358 regular expression. This allows multiple variables to be connected to
5359 the same callback without explicitly listing them all out.
5362 Command Line Parsing:
5363 =====================
5365 There are two different command line parsers available with U-Boot:
5366 the old "simple" one, and the much more powerful "hush" shell:
5368 Old, simple command line parser:
5369 --------------------------------
5371 - supports environment variables (through setenv / saveenv commands)
5372 - several commands on one line, separated by ';'
5373 - variable substitution using "... ${name} ..." syntax
5374 - special characters ('$', ';') can be escaped by prefixing with '\',
5376 setenv bootcmd bootm \${address}
5377 - You can also escape text by enclosing in single apostrophes, for example:
5378 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5383 - similar to Bourne shell, with control structures like
5384 if...then...else...fi, for...do...done; while...do...done,
5385 until...do...done, ...
5386 - supports environment ("global") variables (through setenv / saveenv
5387 commands) and local shell variables (through standard shell syntax
5388 "name=value"); only environment variables can be used with "run"
5394 (1) If a command line (or an environment variable executed by a "run"
5395 command) contains several commands separated by semicolon, and
5396 one of these commands fails, then the remaining commands will be
5399 (2) If you execute several variables with one call to run (i. e.
5400 calling run with a list of variables as arguments), any failing
5401 command will cause "run" to terminate, i. e. the remaining
5402 variables are not executed.
5404 Note for Redundant Ethernet Interfaces:
5405 =======================================
5407 Some boards come with redundant Ethernet interfaces; U-Boot supports
5408 such configurations and is capable of automatic selection of a
5409 "working" interface when needed. MAC assignment works as follows:
5411 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5412 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5413 "eth1addr" (=>eth1), "eth2addr", ...
5415 If the network interface stores some valid MAC address (for instance
5416 in SROM), this is used as default address if there is NO correspon-
5417 ding setting in the environment; if the corresponding environment
5418 variable is set, this overrides the settings in the card; that means:
5420 o If the SROM has a valid MAC address, and there is no address in the
5421 environment, the SROM's address is used.
5423 o If there is no valid address in the SROM, and a definition in the
5424 environment exists, then the value from the environment variable is
5427 o If both the SROM and the environment contain a MAC address, and
5428 both addresses are the same, this MAC address is used.
5430 o If both the SROM and the environment contain a MAC address, and the
5431 addresses differ, the value from the environment is used and a
5434 o If neither SROM nor the environment contain a MAC address, an error
5435 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5436 a random, locally-assigned MAC is used.
5438 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5439 will be programmed into hardware as part of the initialization process. This
5440 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5441 The naming convention is as follows:
5442 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5447 U-Boot is capable of booting (and performing other auxiliary operations on)
5448 images in two formats:
5450 New uImage format (FIT)
5451 -----------------------
5453 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5454 to Flattened Device Tree). It allows the use of images with multiple
5455 components (several kernels, ramdisks, etc.), with contents protected by
5456 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5462 Old image format is based on binary files which can be basically anything,
5463 preceded by a special header; see the definitions in include/image.h for
5464 details; basically, the header defines the following image properties:
5466 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5467 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5468 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5469 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5471 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5472 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5473 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5474 * Compression Type (uncompressed, gzip, bzip2)
5480 The header is marked by a special Magic Number, and both the header
5481 and the data portions of the image are secured against corruption by
5488 Although U-Boot should support any OS or standalone application
5489 easily, the main focus has always been on Linux during the design of
5492 U-Boot includes many features that so far have been part of some
5493 special "boot loader" code within the Linux kernel. Also, any
5494 "initrd" images to be used are no longer part of one big Linux image;
5495 instead, kernel and "initrd" are separate images. This implementation
5496 serves several purposes:
5498 - the same features can be used for other OS or standalone
5499 applications (for instance: using compressed images to reduce the
5500 Flash memory footprint)
5502 - it becomes much easier to port new Linux kernel versions because
5503 lots of low-level, hardware dependent stuff are done by U-Boot
5505 - the same Linux kernel image can now be used with different "initrd"
5506 images; of course this also means that different kernel images can
5507 be run with the same "initrd". This makes testing easier (you don't
5508 have to build a new "zImage.initrd" Linux image when you just
5509 change a file in your "initrd"). Also, a field-upgrade of the
5510 software is easier now.
5516 Porting Linux to U-Boot based systems:
5517 ---------------------------------------
5519 U-Boot cannot save you from doing all the necessary modifications to
5520 configure the Linux device drivers for use with your target hardware
5521 (no, we don't intend to provide a full virtual machine interface to
5524 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5526 Just make sure your machine specific header file (for instance
5527 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5528 Information structure as we define in include/asm-<arch>/u-boot.h,
5529 and make sure that your definition of IMAP_ADDR uses the same value
5530 as your U-Boot configuration in CONFIG_SYS_IMMR.
5532 Note that U-Boot now has a driver model, a unified model for drivers.
5533 If you are adding a new driver, plumb it into driver model. If there
5534 is no uclass available, you are encouraged to create one. See
5538 Configuring the Linux kernel:
5539 -----------------------------
5541 No specific requirements for U-Boot. Make sure you have some root
5542 device (initial ramdisk, NFS) for your target system.
5545 Building a Linux Image:
5546 -----------------------
5548 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5549 not used. If you use recent kernel source, a new build target
5550 "uImage" will exist which automatically builds an image usable by
5551 U-Boot. Most older kernels also have support for a "pImage" target,
5552 which was introduced for our predecessor project PPCBoot and uses a
5553 100% compatible format.
5557 make TQM850L_defconfig
5562 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5563 encapsulate a compressed Linux kernel image with header information,
5564 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5566 * build a standard "vmlinux" kernel image (in ELF binary format):
5568 * convert the kernel into a raw binary image:
5570 ${CROSS_COMPILE}-objcopy -O binary \
5571 -R .note -R .comment \
5572 -S vmlinux linux.bin
5574 * compress the binary image:
5578 * package compressed binary image for U-Boot:
5580 mkimage -A ppc -O linux -T kernel -C gzip \
5581 -a 0 -e 0 -n "Linux Kernel Image" \
5582 -d linux.bin.gz uImage
5585 The "mkimage" tool can also be used to create ramdisk images for use
5586 with U-Boot, either separated from the Linux kernel image, or
5587 combined into one file. "mkimage" encapsulates the images with a 64
5588 byte header containing information about target architecture,
5589 operating system, image type, compression method, entry points, time
5590 stamp, CRC32 checksums, etc.
5592 "mkimage" can be called in two ways: to verify existing images and
5593 print the header information, or to build new images.
5595 In the first form (with "-l" option) mkimage lists the information
5596 contained in the header of an existing U-Boot image; this includes
5597 checksum verification:
5599 tools/mkimage -l image
5600 -l ==> list image header information
5602 The second form (with "-d" option) is used to build a U-Boot image
5603 from a "data file" which is used as image payload:
5605 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5606 -n name -d data_file image
5607 -A ==> set architecture to 'arch'
5608 -O ==> set operating system to 'os'
5609 -T ==> set image type to 'type'
5610 -C ==> set compression type 'comp'
5611 -a ==> set load address to 'addr' (hex)
5612 -e ==> set entry point to 'ep' (hex)
5613 -n ==> set image name to 'name'
5614 -d ==> use image data from 'datafile'
5616 Right now, all Linux kernels for PowerPC systems use the same load
5617 address (0x00000000), but the entry point address depends on the
5620 - 2.2.x kernels have the entry point at 0x0000000C,
5621 - 2.3.x and later kernels have the entry point at 0x00000000.
5623 So a typical call to build a U-Boot image would read:
5625 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5626 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5627 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5628 > examples/uImage.TQM850L
5629 Image Name: 2.4.4 kernel for TQM850L
5630 Created: Wed Jul 19 02:34:59 2000
5631 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5632 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5633 Load Address: 0x00000000
5634 Entry Point: 0x00000000
5636 To verify the contents of the image (or check for corruption):
5638 -> tools/mkimage -l examples/uImage.TQM850L
5639 Image Name: 2.4.4 kernel for TQM850L
5640 Created: Wed Jul 19 02:34:59 2000
5641 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5642 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5643 Load Address: 0x00000000
5644 Entry Point: 0x00000000
5646 NOTE: for embedded systems where boot time is critical you can trade
5647 speed for memory and install an UNCOMPRESSED image instead: this
5648 needs more space in Flash, but boots much faster since it does not
5649 need to be uncompressed:
5651 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5652 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5653 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5654 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5655 > examples/uImage.TQM850L-uncompressed
5656 Image Name: 2.4.4 kernel for TQM850L
5657 Created: Wed Jul 19 02:34:59 2000
5658 Image Type: PowerPC Linux Kernel Image (uncompressed)
5659 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5660 Load Address: 0x00000000
5661 Entry Point: 0x00000000
5664 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5665 when your kernel is intended to use an initial ramdisk:
5667 -> tools/mkimage -n 'Simple Ramdisk Image' \
5668 > -A ppc -O linux -T ramdisk -C gzip \
5669 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5670 Image Name: Simple Ramdisk Image
5671 Created: Wed Jan 12 14:01:50 2000
5672 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5673 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5674 Load Address: 0x00000000
5675 Entry Point: 0x00000000
5677 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5678 option performs the converse operation of the mkimage's second form (the "-d"
5679 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5682 tools/dumpimage -i image -T type -p position data_file
5683 -i ==> extract from the 'image' a specific 'data_file'
5684 -T ==> set image type to 'type'
5685 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5688 Installing a Linux Image:
5689 -------------------------
5691 To downloading a U-Boot image over the serial (console) interface,
5692 you must convert the image to S-Record format:
5694 objcopy -I binary -O srec examples/image examples/image.srec
5696 The 'objcopy' does not understand the information in the U-Boot
5697 image header, so the resulting S-Record file will be relative to
5698 address 0x00000000. To load it to a given address, you need to
5699 specify the target address as 'offset' parameter with the 'loads'
5702 Example: install the image to address 0x40100000 (which on the
5703 TQM8xxL is in the first Flash bank):
5705 => erase 40100000 401FFFFF
5711 ## Ready for S-Record download ...
5712 ~>examples/image.srec
5713 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5715 15989 15990 15991 15992
5716 [file transfer complete]
5718 ## Start Addr = 0x00000000
5721 You can check the success of the download using the 'iminfo' command;
5722 this includes a checksum verification so you can be sure no data
5723 corruption happened:
5727 ## Checking Image at 40100000 ...
5728 Image Name: 2.2.13 for initrd on TQM850L
5729 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5730 Data Size: 335725 Bytes = 327 kB = 0 MB
5731 Load Address: 00000000
5732 Entry Point: 0000000c
5733 Verifying Checksum ... OK
5739 The "bootm" command is used to boot an application that is stored in
5740 memory (RAM or Flash). In case of a Linux kernel image, the contents
5741 of the "bootargs" environment variable is passed to the kernel as
5742 parameters. You can check and modify this variable using the
5743 "printenv" and "setenv" commands:
5746 => printenv bootargs
5747 bootargs=root=/dev/ram
5749 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5751 => printenv bootargs
5752 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5755 ## Booting Linux kernel at 40020000 ...
5756 Image Name: 2.2.13 for NFS on TQM850L
5757 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5758 Data Size: 381681 Bytes = 372 kB = 0 MB
5759 Load Address: 00000000
5760 Entry Point: 0000000c
5761 Verifying Checksum ... OK
5762 Uncompressing Kernel Image ... OK
5763 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
5764 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5765 time_init: decrementer frequency = 187500000/60
5766 Calibrating delay loop... 49.77 BogoMIPS
5767 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5770 If you want to boot a Linux kernel with initial RAM disk, you pass
5771 the memory addresses of both the kernel and the initrd image (PPBCOOT
5772 format!) to the "bootm" command:
5774 => imi 40100000 40200000
5776 ## Checking Image at 40100000 ...
5777 Image Name: 2.2.13 for initrd on TQM850L
5778 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5779 Data Size: 335725 Bytes = 327 kB = 0 MB
5780 Load Address: 00000000
5781 Entry Point: 0000000c
5782 Verifying Checksum ... OK
5784 ## Checking Image at 40200000 ...
5785 Image Name: Simple Ramdisk Image
5786 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5787 Data Size: 566530 Bytes = 553 kB = 0 MB
5788 Load Address: 00000000
5789 Entry Point: 00000000
5790 Verifying Checksum ... OK
5792 => bootm 40100000 40200000
5793 ## Booting Linux kernel at 40100000 ...
5794 Image Name: 2.2.13 for initrd on TQM850L
5795 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5796 Data Size: 335725 Bytes = 327 kB = 0 MB
5797 Load Address: 00000000
5798 Entry Point: 0000000c
5799 Verifying Checksum ... OK
5800 Uncompressing Kernel Image ... OK
5801 ## Loading RAMDisk Image at 40200000 ...
5802 Image Name: Simple Ramdisk Image
5803 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5804 Data Size: 566530 Bytes = 553 kB = 0 MB
5805 Load Address: 00000000
5806 Entry Point: 00000000
5807 Verifying Checksum ... OK
5808 Loading Ramdisk ... OK
5809 Linux version 2.2.13 (wd@denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
5810 Boot arguments: root=/dev/ram
5811 time_init: decrementer frequency = 187500000/60
5812 Calibrating delay loop... 49.77 BogoMIPS
5814 RAMDISK: Compressed image found at block 0
5815 VFS: Mounted root (ext2 filesystem).
5819 Boot Linux and pass a flat device tree:
5822 First, U-Boot must be compiled with the appropriate defines. See the section
5823 titled "Linux Kernel Interface" above for a more in depth explanation. The
5824 following is an example of how to start a kernel and pass an updated
5830 oft=oftrees/mpc8540ads.dtb
5831 => tftp $oftaddr $oft
5832 Speed: 1000, full duplex
5834 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5835 Filename 'oftrees/mpc8540ads.dtb'.
5836 Load address: 0x300000
5839 Bytes transferred = 4106 (100a hex)
5840 => tftp $loadaddr $bootfile
5841 Speed: 1000, full duplex
5843 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5845 Load address: 0x200000
5846 Loading:############
5848 Bytes transferred = 1029407 (fb51f hex)
5853 => bootm $loadaddr - $oftaddr
5854 ## Booting image at 00200000 ...
5855 Image Name: Linux-2.6.17-dirty
5856 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5857 Data Size: 1029343 Bytes = 1005.2 kB
5858 Load Address: 00000000
5859 Entry Point: 00000000
5860 Verifying Checksum ... OK
5861 Uncompressing Kernel Image ... OK
5862 Booting using flat device tree at 0x300000
5863 Using MPC85xx ADS machine description
5864 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5868 More About U-Boot Image Types:
5869 ------------------------------
5871 U-Boot supports the following image types:
5873 "Standalone Programs" are directly runnable in the environment
5874 provided by U-Boot; it is expected that (if they behave
5875 well) you can continue to work in U-Boot after return from
5876 the Standalone Program.
5877 "OS Kernel Images" are usually images of some Embedded OS which
5878 will take over control completely. Usually these programs
5879 will install their own set of exception handlers, device
5880 drivers, set up the MMU, etc. - this means, that you cannot
5881 expect to re-enter U-Boot except by resetting the CPU.
5882 "RAMDisk Images" are more or less just data blocks, and their
5883 parameters (address, size) are passed to an OS kernel that is
5885 "Multi-File Images" contain several images, typically an OS
5886 (Linux) kernel image and one or more data images like
5887 RAMDisks. This construct is useful for instance when you want
5888 to boot over the network using BOOTP etc., where the boot
5889 server provides just a single image file, but you want to get
5890 for instance an OS kernel and a RAMDisk image.
5892 "Multi-File Images" start with a list of image sizes, each
5893 image size (in bytes) specified by an "uint32_t" in network
5894 byte order. This list is terminated by an "(uint32_t)0".
5895 Immediately after the terminating 0 follow the images, one by
5896 one, all aligned on "uint32_t" boundaries (size rounded up to
5897 a multiple of 4 bytes).
5899 "Firmware Images" are binary images containing firmware (like
5900 U-Boot or FPGA images) which usually will be programmed to
5903 "Script files" are command sequences that will be executed by
5904 U-Boot's command interpreter; this feature is especially
5905 useful when you configure U-Boot to use a real shell (hush)
5906 as command interpreter.
5908 Booting the Linux zImage:
5909 -------------------------
5911 On some platforms, it's possible to boot Linux zImage. This is done
5912 using the "bootz" command. The syntax of "bootz" command is the same
5913 as the syntax of "bootm" command.
5915 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5916 kernel with raw initrd images. The syntax is slightly different, the
5917 address of the initrd must be augmented by it's size, in the following
5918 format: "<initrd addres>:<initrd size>".
5924 One of the features of U-Boot is that you can dynamically load and
5925 run "standalone" applications, which can use some resources of
5926 U-Boot like console I/O functions or interrupt services.
5928 Two simple examples are included with the sources:
5933 'examples/hello_world.c' contains a small "Hello World" Demo
5934 application; it is automatically compiled when you build U-Boot.
5935 It's configured to run at address 0x00040004, so you can play with it
5939 ## Ready for S-Record download ...
5940 ~>examples/hello_world.srec
5941 1 2 3 4 5 6 7 8 9 10 11 ...
5942 [file transfer complete]
5944 ## Start Addr = 0x00040004
5946 => go 40004 Hello World! This is a test.
5947 ## Starting application at 0x00040004 ...
5958 Hit any key to exit ...
5960 ## Application terminated, rc = 0x0
5962 Another example, which demonstrates how to register a CPM interrupt
5963 handler with the U-Boot code, can be found in 'examples/timer.c'.
5964 Here, a CPM timer is set up to generate an interrupt every second.
5965 The interrupt service routine is trivial, just printing a '.'
5966 character, but this is just a demo program. The application can be
5967 controlled by the following keys:
5969 ? - print current values og the CPM Timer registers
5970 b - enable interrupts and start timer
5971 e - stop timer and disable interrupts
5972 q - quit application
5975 ## Ready for S-Record download ...
5976 ~>examples/timer.srec
5977 1 2 3 4 5 6 7 8 9 10 11 ...
5978 [file transfer complete]
5980 ## Start Addr = 0x00040004
5983 ## Starting application at 0x00040004 ...
5986 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5989 [q, b, e, ?] Set interval 1000000 us
5992 [q, b, e, ?] ........
5993 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5996 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5999 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
6002 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
6004 [q, b, e, ?] ...Stopping timer
6006 [q, b, e, ?] ## Application terminated, rc = 0x0
6012 Over time, many people have reported problems when trying to use the
6013 "minicom" terminal emulation program for serial download. I (wd)
6014 consider minicom to be broken, and recommend not to use it. Under
6015 Unix, I recommend to use C-Kermit for general purpose use (and
6016 especially for kermit binary protocol download ("loadb" command), and
6017 use "cu" for S-Record download ("loads" command). See
6018 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
6019 for help with kermit.
6022 Nevertheless, if you absolutely want to use it try adding this
6023 configuration to your "File transfer protocols" section:
6025 Name Program Name U/D FullScr IO-Red. Multi
6026 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
6027 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
6033 Starting at version 0.9.2, U-Boot supports NetBSD both as host
6034 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6036 Building requires a cross environment; it is known to work on
6037 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6038 need gmake since the Makefiles are not compatible with BSD make).
6039 Note that the cross-powerpc package does not install include files;
6040 attempting to build U-Boot will fail because <machine/ansi.h> is
6041 missing. This file has to be installed and patched manually:
6043 # cd /usr/pkg/cross/powerpc-netbsd/include
6045 # ln -s powerpc machine
6046 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6047 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6049 Native builds *don't* work due to incompatibilities between native
6050 and U-Boot include files.
6052 Booting assumes that (the first part of) the image booted is a
6053 stage-2 loader which in turn loads and then invokes the kernel
6054 proper. Loader sources will eventually appear in the NetBSD source
6055 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6056 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6059 Implementation Internals:
6060 =========================
6062 The following is not intended to be a complete description of every
6063 implementation detail. However, it should help to understand the
6064 inner workings of U-Boot and make it easier to port it to custom
6068 Initial Stack, Global Data:
6069 ---------------------------
6071 The implementation of U-Boot is complicated by the fact that U-Boot
6072 starts running out of ROM (flash memory), usually without access to
6073 system RAM (because the memory controller is not initialized yet).
6074 This means that we don't have writable Data or BSS segments, and BSS
6075 is not initialized as zero. To be able to get a C environment working
6076 at all, we have to allocate at least a minimal stack. Implementation
6077 options for this are defined and restricted by the CPU used: Some CPU
6078 models provide on-chip memory (like the IMMR area on MPC8xx and
6079 MPC826x processors), on others (parts of) the data cache can be
6080 locked as (mis-) used as memory, etc.
6082 Chris Hallinan posted a good summary of these issues to the
6083 U-Boot mailing list:
6085 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6086 From: "Chris Hallinan" <clh@net1plus.com>
6087 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6090 Correct me if I'm wrong, folks, but the way I understand it
6091 is this: Using DCACHE as initial RAM for Stack, etc, does not
6092 require any physical RAM backing up the cache. The cleverness
6093 is that the cache is being used as a temporary supply of
6094 necessary storage before the SDRAM controller is setup. It's
6095 beyond the scope of this list to explain the details, but you
6096 can see how this works by studying the cache architecture and
6097 operation in the architecture and processor-specific manuals.
6099 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6100 is another option for the system designer to use as an
6101 initial stack/RAM area prior to SDRAM being available. Either
6102 option should work for you. Using CS 4 should be fine if your
6103 board designers haven't used it for something that would
6104 cause you grief during the initial boot! It is frequently not
6107 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6108 with your processor/board/system design. The default value
6109 you will find in any recent u-boot distribution in
6110 walnut.h should work for you. I'd set it to a value larger
6111 than your SDRAM module. If you have a 64MB SDRAM module, set
6112 it above 400_0000. Just make sure your board has no resources
6113 that are supposed to respond to that address! That code in
6114 start.S has been around a while and should work as is when
6115 you get the config right.
6120 It is essential to remember this, since it has some impact on the C
6121 code for the initialization procedures:
6123 * Initialized global data (data segment) is read-only. Do not attempt
6126 * Do not use any uninitialized global data (or implicitly initialized
6127 as zero data - BSS segment) at all - this is undefined, initiali-
6128 zation is performed later (when relocating to RAM).
6130 * Stack space is very limited. Avoid big data buffers or things like
6133 Having only the stack as writable memory limits means we cannot use
6134 normal global data to share information between the code. But it
6135 turned out that the implementation of U-Boot can be greatly
6136 simplified by making a global data structure (gd_t) available to all
6137 functions. We could pass a pointer to this data as argument to _all_
6138 functions, but this would bloat the code. Instead we use a feature of
6139 the GCC compiler (Global Register Variables) to share the data: we
6140 place a pointer (gd) to the global data into a register which we
6141 reserve for this purpose.
6143 When choosing a register for such a purpose we are restricted by the
6144 relevant (E)ABI specifications for the current architecture, and by
6145 GCC's implementation.
6147 For PowerPC, the following registers have specific use:
6149 R2: reserved for system use
6150 R3-R4: parameter passing and return values
6151 R5-R10: parameter passing
6152 R13: small data area pointer
6156 (U-Boot also uses R12 as internal GOT pointer. r12
6157 is a volatile register so r12 needs to be reset when
6158 going back and forth between asm and C)
6160 ==> U-Boot will use R2 to hold a pointer to the global data
6162 Note: on PPC, we could use a static initializer (since the
6163 address of the global data structure is known at compile time),
6164 but it turned out that reserving a register results in somewhat
6165 smaller code - although the code savings are not that big (on
6166 average for all boards 752 bytes for the whole U-Boot image,
6167 624 text + 127 data).
6169 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6170 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6172 ==> U-Boot will use P3 to hold a pointer to the global data
6174 On ARM, the following registers are used:
6176 R0: function argument word/integer result
6177 R1-R3: function argument word
6178 R9: platform specific
6179 R10: stack limit (used only if stack checking is enabled)
6180 R11: argument (frame) pointer
6181 R12: temporary workspace
6184 R15: program counter
6186 ==> U-Boot will use R9 to hold a pointer to the global data
6188 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6190 On Nios II, the ABI is documented here:
6191 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6193 ==> U-Boot will use gp to hold a pointer to the global data
6195 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6196 to access small data sections, so gp is free.
6198 On NDS32, the following registers are used:
6200 R0-R1: argument/return
6202 R15: temporary register for assembler
6203 R16: trampoline register
6204 R28: frame pointer (FP)
6205 R29: global pointer (GP)
6206 R30: link register (LP)
6207 R31: stack pointer (SP)
6208 PC: program counter (PC)
6210 ==> U-Boot will use R10 to hold a pointer to the global data
6212 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6213 or current versions of GCC may "optimize" the code too much.
6218 U-Boot runs in system state and uses physical addresses, i.e. the
6219 MMU is not used either for address mapping nor for memory protection.
6221 The available memory is mapped to fixed addresses using the memory
6222 controller. In this process, a contiguous block is formed for each
6223 memory type (Flash, SDRAM, SRAM), even when it consists of several
6224 physical memory banks.
6226 U-Boot is installed in the first 128 kB of the first Flash bank (on
6227 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6228 booting and sizing and initializing DRAM, the code relocates itself
6229 to the upper end of DRAM. Immediately below the U-Boot code some
6230 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6231 configuration setting]. Below that, a structure with global Board
6232 Info data is placed, followed by the stack (growing downward).
6234 Additionally, some exception handler code is copied to the low 8 kB
6235 of DRAM (0x00000000 ... 0x00001FFF).
6237 So a typical memory configuration with 16 MB of DRAM could look like
6240 0x0000 0000 Exception Vector code
6243 0x0000 2000 Free for Application Use
6249 0x00FB FF20 Monitor Stack (Growing downward)
6250 0x00FB FFAC Board Info Data and permanent copy of global data
6251 0x00FC 0000 Malloc Arena
6254 0x00FE 0000 RAM Copy of Monitor Code
6255 ... eventually: LCD or video framebuffer
6256 ... eventually: pRAM (Protected RAM - unchanged by reset)
6257 0x00FF FFFF [End of RAM]
6260 System Initialization:
6261 ----------------------
6263 In the reset configuration, U-Boot starts at the reset entry point
6264 (on most PowerPC systems at address 0x00000100). Because of the reset
6265 configuration for CS0# this is a mirror of the on board Flash memory.
6266 To be able to re-map memory U-Boot then jumps to its link address.
6267 To be able to implement the initialization code in C, a (small!)
6268 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6269 which provide such a feature like MPC8xx or MPC8260), or in a locked
6270 part of the data cache. After that, U-Boot initializes the CPU core,
6271 the caches and the SIU.
6273 Next, all (potentially) available memory banks are mapped using a
6274 preliminary mapping. For example, we put them on 512 MB boundaries
6275 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6276 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6277 programmed for SDRAM access. Using the temporary configuration, a
6278 simple memory test is run that determines the size of the SDRAM
6281 When there is more than one SDRAM bank, and the banks are of
6282 different size, the largest is mapped first. For equal size, the first
6283 bank (CS2#) is mapped first. The first mapping is always for address
6284 0x00000000, with any additional banks following immediately to create
6285 contiguous memory starting from 0.
6287 Then, the monitor installs itself at the upper end of the SDRAM area
6288 and allocates memory for use by malloc() and for the global Board
6289 Info data; also, the exception vector code is copied to the low RAM
6290 pages, and the final stack is set up.
6292 Only after this relocation will you have a "normal" C environment;
6293 until that you are restricted in several ways, mostly because you are
6294 running from ROM, and because the code will have to be relocated to a
6298 U-Boot Porting Guide:
6299 ----------------------
6301 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6305 int main(int argc, char *argv[])
6307 sighandler_t no_more_time;
6309 signal(SIGALRM, no_more_time);
6310 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6312 if (available_money > available_manpower) {
6313 Pay consultant to port U-Boot;
6317 Download latest U-Boot source;
6319 Subscribe to u-boot mailing list;
6322 email("Hi, I am new to U-Boot, how do I get started?");
6325 Read the README file in the top level directory;
6326 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6327 Read applicable doc/*.README;
6328 Read the source, Luke;
6329 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6332 if (available_money > toLocalCurrency ($2500))
6335 Add a lot of aggravation and time;
6337 if (a similar board exists) { /* hopefully... */
6338 cp -a board/<similar> board/<myboard>
6339 cp include/configs/<similar>.h include/configs/<myboard>.h
6341 Create your own board support subdirectory;
6342 Create your own board include/configs/<myboard>.h file;
6344 Edit new board/<myboard> files
6345 Edit new include/configs/<myboard>.h
6350 Add / modify source code;
6354 email("Hi, I am having problems...");
6356 Send patch file to the U-Boot email list;
6357 if (reasonable critiques)
6358 Incorporate improvements from email list code review;
6360 Defend code as written;
6366 void no_more_time (int sig)
6375 All contributions to U-Boot should conform to the Linux kernel
6376 coding style; see the file "Documentation/CodingStyle" and the script
6377 "scripts/Lindent" in your Linux kernel source directory.
6379 Source files originating from a different project (for example the
6380 MTD subsystem) are generally exempt from these guidelines and are not
6381 reformatted to ease subsequent migration to newer versions of those
6384 Please note that U-Boot is implemented in C (and to some small parts in
6385 Assembler); no C++ is used, so please do not use C++ style comments (//)
6388 Please also stick to the following formatting rules:
6389 - remove any trailing white space
6390 - use TAB characters for indentation and vertical alignment, not spaces
6391 - make sure NOT to use DOS '\r\n' line feeds
6392 - do not add more than 2 consecutive empty lines to source files
6393 - do not add trailing empty lines to source files
6395 Submissions which do not conform to the standards may be returned
6396 with a request to reformat the changes.
6402 Since the number of patches for U-Boot is growing, we need to
6403 establish some rules. Submissions which do not conform to these rules
6404 may be rejected, even when they contain important and valuable stuff.
6406 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6408 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6409 see http://lists.denx.de/mailman/listinfo/u-boot
6411 When you send a patch, please include the following information with
6414 * For bug fixes: a description of the bug and how your patch fixes
6415 this bug. Please try to include a way of demonstrating that the
6416 patch actually fixes something.
6418 * For new features: a description of the feature and your
6421 * A CHANGELOG entry as plaintext (separate from the patch)
6423 * For major contributions, add a MAINTAINERS file with your
6424 information and associated file and directory references.
6426 * When you add support for a new board, don't forget to add a
6427 maintainer e-mail address to the boards.cfg file, too.
6429 * If your patch adds new configuration options, don't forget to
6430 document these in the README file.
6432 * The patch itself. If you are using git (which is *strongly*
6433 recommended) you can easily generate the patch using the
6434 "git format-patch". If you then use "git send-email" to send it to
6435 the U-Boot mailing list, you will avoid most of the common problems
6436 with some other mail clients.
6438 If you cannot use git, use "diff -purN OLD NEW". If your version of
6439 diff does not support these options, then get the latest version of
6442 The current directory when running this command shall be the parent
6443 directory of the U-Boot source tree (i. e. please make sure that
6444 your patch includes sufficient directory information for the
6447 We prefer patches as plain text. MIME attachments are discouraged,
6448 and compressed attachments must not be used.
6450 * If one logical set of modifications affects or creates several
6451 files, all these changes shall be submitted in a SINGLE patch file.
6453 * Changesets that contain different, unrelated modifications shall be
6454 submitted as SEPARATE patches, one patch per changeset.
6459 * Before sending the patch, run the buildman script on your patched
6460 source tree and make sure that no errors or warnings are reported
6461 for any of the boards.
6463 * Keep your modifications to the necessary minimum: A patch
6464 containing several unrelated changes or arbitrary reformats will be
6465 returned with a request to re-formatting / split it.
6467 * If you modify existing code, make sure that your new code does not
6468 add to the memory footprint of the code ;-) Small is beautiful!
6469 When adding new features, these should compile conditionally only
6470 (using #ifdef), and the resulting code with the new feature
6471 disabled must not need more memory than the old code without your
6474 * Remember that there is a size limit of 100 kB per message on the
6475 u-boot mailing list. Bigger patches will be moderated. If they are
6476 reasonable and not too big, they will be acknowledged. But patches
6477 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob