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 U-Boot can detect if an IDE device is present or not.
701 If not, and this new config option is activated, U-Boot
702 removes the ATA node from the DTS before booting Linux,
703 so the Linux IDE driver does not probe the device and
704 crash. This is needed for buggy hardware (uc101) where
705 no pull down resistor is connected to the signal IDE5V_DD7.
707 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
709 This setting is mandatory for all boards that have only one
710 machine type and must be used to specify the machine type
711 number as it appears in the ARM machine registry
712 (see http://www.arm.linux.org.uk/developer/machines/).
713 Only boards that have multiple machine types supported
714 in a single configuration file and the machine type is
715 runtime discoverable, do not have to use this setting.
717 - vxWorks boot parameters:
719 bootvx constructs a valid bootline using the following
720 environments variables: bootdev, bootfile, ipaddr, netmask,
721 serverip, gatewayip, hostname, othbootargs.
722 It loads the vxWorks image pointed bootfile.
724 Note: If a "bootargs" environment is defined, it will overwride
725 the defaults discussed just above.
727 - Cache Configuration:
728 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
729 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
730 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
732 - Cache Configuration for ARM:
733 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
735 CONFIG_SYS_PL310_BASE - Physical base address of PL310
736 controller register space
741 Define this if you want support for Amba PrimeCell PL010 UARTs.
745 Define this if you want support for Amba PrimeCell PL011 UARTs.
749 If you have Amba PrimeCell PL011 UARTs, set this variable to
750 the clock speed of the UARTs.
754 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
755 define this to a list of base addresses for each (supported)
756 port. See e.g. include/configs/versatile.h
758 CONFIG_SERIAL_HW_FLOW_CONTROL
760 Define this variable to enable hw flow control in serial driver.
761 Current user of this option is drivers/serial/nsl16550.c driver
764 Depending on board, define exactly one serial port
765 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
766 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
767 console by defining CONFIG_8xx_CONS_NONE
769 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
770 port routines must be defined elsewhere
771 (i.e. serial_init(), serial_getc(), ...)
774 Enables console device for a color framebuffer. Needs following
775 defines (cf. smiLynxEM, i8042)
776 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
778 VIDEO_HW_RECTFILL graphic chip supports
781 VIDEO_HW_BITBLT graphic chip supports
782 bit-blit (cf. smiLynxEM)
783 VIDEO_VISIBLE_COLS visible pixel columns
785 VIDEO_VISIBLE_ROWS visible pixel rows
786 VIDEO_PIXEL_SIZE bytes per pixel
787 VIDEO_DATA_FORMAT graphic data format
788 (0-5, cf. cfb_console.c)
789 VIDEO_FB_ADRS framebuffer address
790 VIDEO_KBD_INIT_FCT keyboard int fct
791 (i.e. rx51_kp_init())
792 VIDEO_TSTC_FCT test char fct
794 VIDEO_GETC_FCT get char fct
796 CONFIG_VIDEO_LOGO display Linux logo in
798 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
799 linux_logo.h for logo.
800 Requires CONFIG_VIDEO_LOGO
801 CONFIG_CONSOLE_EXTRA_INFO
802 additional board info beside
804 CONFIG_HIDE_LOGO_VERSION
805 do not display bootloader
808 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
809 a limited number of ANSI escape sequences (cursor control,
810 erase functions and limited graphics rendition control).
812 When CONFIG_CFB_CONSOLE is defined, video console is
813 default i/o. Serial console can be forced with
814 environment 'console=serial'.
816 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
818 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
822 CONFIG_BAUDRATE - in bps
823 Select one of the baudrates listed in
824 CONFIG_SYS_BAUDRATE_TABLE, see below.
825 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
827 - Console Rx buffer length
828 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
829 the maximum receive buffer length for the SMC.
830 This option is actual only for 82xx and 8xx possible.
831 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
832 must be defined, to setup the maximum idle timeout for
835 - Pre-Console Buffer:
836 Prior to the console being initialised (i.e. serial UART
837 initialised etc) all console output is silently discarded.
838 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
839 buffer any console messages prior to the console being
840 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
841 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
842 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
843 bytes are output before the console is initialised, the
844 earlier bytes are discarded.
846 Note that when printing the buffer a copy is made on the
847 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
849 'Sane' compilers will generate smaller code if
850 CONFIG_PRE_CON_BUF_SZ is a power of 2
854 Only needed when CONFIG_BOOTDELAY is enabled;
855 define a command string that is automatically executed
856 when no character is read on the console interface
857 within "Boot Delay" after reset.
860 This can be used to pass arguments to the bootm
861 command. The value of CONFIG_BOOTARGS goes into the
862 environment value "bootargs".
864 CONFIG_RAMBOOT and CONFIG_NFSBOOT
865 The value of these goes into the environment as
866 "ramboot" and "nfsboot" respectively, and can be used
867 as a convenience, when switching between booting from
871 CONFIG_BOOTCOUNT_LIMIT
872 Implements a mechanism for detecting a repeating reboot
874 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
877 If no softreset save registers are found on the hardware
878 "bootcount" is stored in the environment. To prevent a
879 saveenv on all reboots, the environment variable
880 "upgrade_available" is used. If "upgrade_available" is
881 0, "bootcount" is always 0, if "upgrade_available" is
882 1 "bootcount" is incremented in the environment.
883 So the Userspace Applikation must set the "upgrade_available"
884 and "bootcount" variable to 0, if a boot was successfully.
889 When this option is #defined, the existence of the
890 environment variable "preboot" will be checked
891 immediately before starting the CONFIG_BOOTDELAY
892 countdown and/or running the auto-boot command resp.
893 entering interactive mode.
895 This feature is especially useful when "preboot" is
896 automatically generated or modified. For an example
897 see the LWMON board specific code: here "preboot" is
898 modified when the user holds down a certain
899 combination of keys on the (special) keyboard when
902 - Serial Download Echo Mode:
904 If defined to 1, all characters received during a
905 serial download (using the "loads" command) are
906 echoed back. This might be needed by some terminal
907 emulations (like "cu"), but may as well just take
908 time on others. This setting #define's the initial
909 value of the "loads_echo" environment variable.
911 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
913 Select one of the baudrates listed in
914 CONFIG_SYS_BAUDRATE_TABLE, see below.
917 Monitor commands can be included or excluded
918 from the build by using the #include files
919 <config_cmd_all.h> and #undef'ing unwanted
920 commands, or adding #define's for wanted commands.
922 The default command configuration includes all commands
923 except those marked below with a "*".
925 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
926 CONFIG_CMD_ASKENV * ask for env variable
927 CONFIG_CMD_BDI bdinfo
928 CONFIG_CMD_BEDBUG * Include BedBug Debugger
929 CONFIG_CMD_BMP * BMP support
930 CONFIG_CMD_BSP * Board specific commands
931 CONFIG_CMD_BOOTD bootd
932 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
933 CONFIG_CMD_CACHE * icache, dcache
934 CONFIG_CMD_CLK * clock command support
935 CONFIG_CMD_CONSOLE coninfo
936 CONFIG_CMD_CRC32 * crc32
937 CONFIG_CMD_DATE * support for RTC, date/time...
938 CONFIG_CMD_DHCP * DHCP support
939 CONFIG_CMD_DIAG * Diagnostics
940 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
941 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
942 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
943 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
944 CONFIG_CMD_DTT * Digital Therm and Thermostat
945 CONFIG_CMD_ECHO echo arguments
946 CONFIG_CMD_EDITENV edit env variable
947 CONFIG_CMD_EEPROM * EEPROM read/write support
948 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
949 CONFIG_CMD_ELF * bootelf, bootvx
950 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
951 CONFIG_CMD_ENV_FLAGS * display details about env flags
952 CONFIG_CMD_ENV_EXISTS * check existence of env variable
953 CONFIG_CMD_EXPORTENV * export the environment
954 CONFIG_CMD_EXT2 * ext2 command support
955 CONFIG_CMD_EXT4 * ext4 command support
956 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
957 that work for multiple fs types
958 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
959 CONFIG_CMD_SAVEENV saveenv
960 CONFIG_CMD_FDC * Floppy Disk Support
961 CONFIG_CMD_FAT * FAT command support
962 CONFIG_CMD_FLASH flinfo, erase, protect
963 CONFIG_CMD_FPGA FPGA device initialization support
964 CONFIG_CMD_FUSE * Device fuse support
965 CONFIG_CMD_GETTIME * Get time since boot
966 CONFIG_CMD_GO * the 'go' command (exec code)
967 CONFIG_CMD_GREPENV * search environment
968 CONFIG_CMD_HASH * calculate hash / digest
969 CONFIG_CMD_I2C * I2C serial bus support
970 CONFIG_CMD_IDE * IDE harddisk support
971 CONFIG_CMD_IMI iminfo
972 CONFIG_CMD_IMLS List all images found in NOR flash
973 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
974 CONFIG_CMD_IMMAP * IMMR dump support
975 CONFIG_CMD_IOTRACE * I/O tracing for debugging
976 CONFIG_CMD_IMPORTENV * import an environment
977 CONFIG_CMD_INI * import data from an ini file into the env
978 CONFIG_CMD_IRQ * irqinfo
979 CONFIG_CMD_ITEST Integer/string test of 2 values
980 CONFIG_CMD_JFFS2 * JFFS2 Support
981 CONFIG_CMD_KGDB * kgdb
982 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
983 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
985 CONFIG_CMD_LOADB loadb
986 CONFIG_CMD_LOADS loads
987 CONFIG_CMD_MD5SUM * print md5 message digest
988 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
989 CONFIG_CMD_MEMINFO * Display detailed memory information
990 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
992 CONFIG_CMD_MEMTEST * mtest
993 CONFIG_CMD_MISC Misc functions like sleep etc
994 CONFIG_CMD_MMC * MMC memory mapped support
995 CONFIG_CMD_MII * MII utility commands
996 CONFIG_CMD_MTDPARTS * MTD partition support
997 CONFIG_CMD_NAND * NAND support
998 CONFIG_CMD_NET bootp, tftpboot, rarpboot
999 CONFIG_CMD_NFS NFS support
1000 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1001 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1002 CONFIG_CMD_PCI * pciinfo
1003 CONFIG_CMD_PCMCIA * PCMCIA support
1004 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1006 CONFIG_CMD_PORTIO * Port I/O
1007 CONFIG_CMD_READ * Read raw data from partition
1008 CONFIG_CMD_REGINFO * Register dump
1009 CONFIG_CMD_RUN run command in env variable
1010 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1011 CONFIG_CMD_SAVES * save S record dump
1012 CONFIG_SCSI * SCSI Support
1013 CONFIG_CMD_SDRAM * print SDRAM configuration information
1014 (requires CONFIG_CMD_I2C)
1015 CONFIG_CMD_SETGETDCR Support for DCR Register access
1017 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1018 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1019 (requires CONFIG_CMD_MEMORY)
1020 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1021 CONFIG_CMD_SOURCE "source" command Support
1022 CONFIG_CMD_SPI * SPI serial bus support
1023 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1024 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1025 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1026 CONFIG_CMD_TIMER * access to the system tick timer
1027 CONFIG_CMD_USB * USB support
1028 CONFIG_CMD_CDP * Cisco Discover Protocol support
1029 CONFIG_CMD_MFSL * Microblaze FSL support
1030 CONFIG_CMD_XIMG Load part of Multi Image
1031 CONFIG_CMD_UUID * Generate random UUID or GUID string
1033 EXAMPLE: If you want all functions except of network
1034 support you can write:
1036 #include "config_cmd_all.h"
1037 #undef CONFIG_CMD_NET
1040 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1042 Note: Don't enable the "icache" and "dcache" commands
1043 (configuration option CONFIG_CMD_CACHE) unless you know
1044 what you (and your U-Boot users) are doing. Data
1045 cache cannot be enabled on systems like the 8xx or
1046 8260 (where accesses to the IMMR region must be
1047 uncached), and it cannot be disabled on all other
1048 systems where we (mis-) use the data cache to hold an
1049 initial stack and some data.
1052 XXX - this list needs to get updated!
1054 - Removal of commands
1055 If no commands are needed to boot, you can disable
1056 CONFIG_CMDLINE to remove them. In this case, the command line
1057 will not be available, and when U-Boot wants to execute the
1058 boot command (on start-up) it will call board_run_command()
1059 instead. This can reduce image size significantly for very
1060 simple boot procedures.
1062 - Regular expression support:
1064 If this variable is defined, U-Boot is linked against
1065 the SLRE (Super Light Regular Expression) library,
1066 which adds regex support to some commands, as for
1067 example "env grep" and "setexpr".
1071 If this variable is defined, U-Boot will use a device tree
1072 to configure its devices, instead of relying on statically
1073 compiled #defines in the board file. This option is
1074 experimental and only available on a few boards. The device
1075 tree is available in the global data as gd->fdt_blob.
1077 U-Boot needs to get its device tree from somewhere. This can
1078 be done using one of the two options below:
1081 If this variable is defined, U-Boot will embed a device tree
1082 binary in its image. This device tree file should be in the
1083 board directory and called <soc>-<board>.dts. The binary file
1084 is then picked up in board_init_f() and made available through
1085 the global data structure as gd->blob.
1088 If this variable is defined, U-Boot will build a device tree
1089 binary. It will be called u-boot.dtb. Architecture-specific
1090 code will locate it at run-time. Generally this works by:
1092 cat u-boot.bin u-boot.dtb >image.bin
1094 and in fact, U-Boot does this for you, creating a file called
1095 u-boot-dtb.bin which is useful in the common case. You can
1096 still use the individual files if you need something more
1101 If this variable is defined, it enables watchdog
1102 support for the SoC. There must be support in the SoC
1103 specific code for a watchdog. For the 8xx and 8260
1104 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1105 register. When supported for a specific SoC is
1106 available, then no further board specific code should
1107 be needed to use it.
1110 When using a watchdog circuitry external to the used
1111 SoC, then define this variable and provide board
1112 specific code for the "hw_watchdog_reset" function.
1114 CONFIG_AT91_HW_WDT_TIMEOUT
1115 specify the timeout in seconds. default 2 seconds.
1118 CONFIG_VERSION_VARIABLE
1119 If this variable is defined, an environment variable
1120 named "ver" is created by U-Boot showing the U-Boot
1121 version as printed by the "version" command.
1122 Any change to this variable will be reverted at the
1127 When CONFIG_CMD_DATE is selected, the type of the RTC
1128 has to be selected, too. Define exactly one of the
1131 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1132 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1133 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1134 CONFIG_RTC_MC146818 - use MC146818 RTC
1135 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1136 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1137 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1138 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1139 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1140 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1141 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1142 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1143 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1146 Note that if the RTC uses I2C, then the I2C interface
1147 must also be configured. See I2C Support, below.
1150 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1152 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1153 chip-ngpio pairs that tell the PCA953X driver the number of
1154 pins supported by a particular chip.
1156 Note that if the GPIO device uses I2C, then the I2C interface
1157 must also be configured. See I2C Support, below.
1160 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1161 accesses and can checksum them or write a list of them out
1162 to memory. See the 'iotrace' command for details. This is
1163 useful for testing device drivers since it can confirm that
1164 the driver behaves the same way before and after a code
1165 change. Currently this is supported on sandbox and arm. To
1166 add support for your architecture, add '#include <iotrace.h>'
1167 to the bottom of arch/<arch>/include/asm/io.h and test.
1169 Example output from the 'iotrace stats' command is below.
1170 Note that if the trace buffer is exhausted, the checksum will
1171 still continue to operate.
1174 Start: 10000000 (buffer start address)
1175 Size: 00010000 (buffer size)
1176 Offset: 00000120 (current buffer offset)
1177 Output: 10000120 (start + offset)
1178 Count: 00000018 (number of trace records)
1179 CRC32: 9526fb66 (CRC32 of all trace records)
1181 - Timestamp Support:
1183 When CONFIG_TIMESTAMP is selected, the timestamp
1184 (date and time) of an image is printed by image
1185 commands like bootm or iminfo. This option is
1186 automatically enabled when you select CONFIG_CMD_DATE .
1188 - Partition Labels (disklabels) Supported:
1189 Zero or more of the following:
1190 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1191 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1192 Intel architecture, USB sticks, etc.
1193 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1194 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1195 bootloader. Note 2TB partition limit; see
1197 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1199 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1200 CONFIG_SCSI) you must configure support for at
1201 least one non-MTD partition type as well.
1204 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1205 board configurations files but used nowhere!
1207 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1208 be performed by calling the function
1209 ide_set_reset(int reset)
1210 which has to be defined in a board specific file
1215 Set this to enable ATAPI support.
1220 Set this to enable support for disks larger than 137GB
1221 Also look at CONFIG_SYS_64BIT_LBA.
1222 Whithout these , LBA48 support uses 32bit variables and will 'only'
1223 support disks up to 2.1TB.
1225 CONFIG_SYS_64BIT_LBA:
1226 When enabled, makes the IDE subsystem use 64bit sector addresses.
1230 At the moment only there is only support for the
1231 SYM53C8XX SCSI controller; define
1232 CONFIG_SCSI_SYM53C8XX to enable it.
1234 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1235 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1236 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1237 maximum numbers of LUNs, SCSI ID's and target
1239 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1241 The environment variable 'scsidevs' is set to the number of
1242 SCSI devices found during the last scan.
1244 - NETWORK Support (PCI):
1246 Support for Intel 8254x/8257x gigabit chips.
1249 Utility code for direct access to the SPI bus on Intel 8257x.
1250 This does not do anything useful unless you set at least one
1251 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1253 CONFIG_E1000_SPI_GENERIC
1254 Allow generic access to the SPI bus on the Intel 8257x, for
1255 example with the "sspi" command.
1258 Management command for E1000 devices. When used on devices
1259 with SPI support you can reprogram the EEPROM from U-Boot.
1262 Support for Intel 82557/82559/82559ER chips.
1263 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1264 write routine for first time initialisation.
1267 Support for Digital 2114x chips.
1268 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1269 modem chip initialisation (KS8761/QS6611).
1272 Support for National dp83815 chips.
1275 Support for National dp8382[01] gigabit chips.
1277 - NETWORK Support (other):
1279 CONFIG_DRIVER_AT91EMAC
1280 Support for AT91RM9200 EMAC.
1283 Define this to use reduced MII inteface
1285 CONFIG_DRIVER_AT91EMAC_QUIET
1286 If this defined, the driver is quiet.
1287 The driver doen't show link status messages.
1289 CONFIG_CALXEDA_XGMAC
1290 Support for the Calxeda XGMAC device
1293 Support for SMSC's LAN91C96 chips.
1295 CONFIG_LAN91C96_USE_32_BIT
1296 Define this to enable 32 bit addressing
1299 Support for SMSC's LAN91C111 chip
1301 CONFIG_SMC91111_BASE
1302 Define this to hold the physical address
1303 of the device (I/O space)
1305 CONFIG_SMC_USE_32_BIT
1306 Define this if data bus is 32 bits
1308 CONFIG_SMC_USE_IOFUNCS
1309 Define this to use i/o functions instead of macros
1310 (some hardware wont work with macros)
1312 CONFIG_DRIVER_TI_EMAC
1313 Support for davinci emac
1315 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1316 Define this if you have more then 3 PHYs.
1319 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1321 CONFIG_FTGMAC100_EGIGA
1322 Define this to use GE link update with gigabit PHY.
1323 Define this if FTGMAC100 is connected to gigabit PHY.
1324 If your system has 10/100 PHY only, it might not occur
1325 wrong behavior. Because PHY usually return timeout or
1326 useless data when polling gigabit status and gigabit
1327 control registers. This behavior won't affect the
1328 correctnessof 10/100 link speed update.
1331 Support for SMSC's LAN911x and LAN921x chips
1334 Define this to hold the physical address
1335 of the device (I/O space)
1337 CONFIG_SMC911X_32_BIT
1338 Define this if data bus is 32 bits
1340 CONFIG_SMC911X_16_BIT
1341 Define this if data bus is 16 bits. If your processor
1342 automatically converts one 32 bit word to two 16 bit
1343 words you may also try CONFIG_SMC911X_32_BIT.
1346 Support for Renesas on-chip Ethernet controller
1348 CONFIG_SH_ETHER_USE_PORT
1349 Define the number of ports to be used
1351 CONFIG_SH_ETHER_PHY_ADDR
1352 Define the ETH PHY's address
1354 CONFIG_SH_ETHER_CACHE_WRITEBACK
1355 If this option is set, the driver enables cache flush.
1359 Support for PWM module on the imx6.
1363 Support TPM devices.
1365 CONFIG_TPM_TIS_INFINEON
1366 Support for Infineon i2c bus TPM devices. Only one device
1367 per system is supported at this time.
1369 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1370 Define the burst count bytes upper limit
1373 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1375 CONFIG_TPM_ST33ZP24_I2C
1376 Support for STMicroelectronics ST33ZP24 I2C devices.
1377 Requires TPM_ST33ZP24 and I2C.
1379 CONFIG_TPM_ST33ZP24_SPI
1380 Support for STMicroelectronics ST33ZP24 SPI devices.
1381 Requires TPM_ST33ZP24 and SPI.
1383 CONFIG_TPM_ATMEL_TWI
1384 Support for Atmel TWI TPM device. Requires I2C support.
1387 Support for generic parallel port TPM devices. Only one device
1388 per system is supported at this time.
1390 CONFIG_TPM_TIS_BASE_ADDRESS
1391 Base address where the generic TPM device is mapped
1392 to. Contemporary x86 systems usually map it at
1396 Add tpm monitor functions.
1397 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1398 provides monitor access to authorized functions.
1401 Define this to enable the TPM support library which provides
1402 functional interfaces to some TPM commands.
1403 Requires support for a TPM device.
1405 CONFIG_TPM_AUTH_SESSIONS
1406 Define this to enable authorized functions in the TPM library.
1407 Requires CONFIG_TPM and CONFIG_SHA1.
1410 At the moment only the UHCI host controller is
1411 supported (PIP405, MIP405, MPC5200); define
1412 CONFIG_USB_UHCI to enable it.
1413 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1414 and define CONFIG_USB_STORAGE to enable the USB
1417 Supported are USB Keyboards and USB Floppy drives
1419 MPC5200 USB requires additional defines:
1421 for 528 MHz Clock: 0x0001bbbb
1425 for differential drivers: 0x00001000
1426 for single ended drivers: 0x00005000
1427 for differential drivers on PSC3: 0x00000100
1428 for single ended drivers on PSC3: 0x00004100
1429 CONFIG_SYS_USB_EVENT_POLL
1430 May be defined to allow interrupt polling
1431 instead of using asynchronous interrupts
1433 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1434 txfilltuning field in the EHCI controller on reset.
1436 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1437 HW module registers.
1440 Define the below if you wish to use the USB console.
1441 Once firmware is rebuilt from a serial console issue the
1442 command "setenv stdin usbtty; setenv stdout usbtty" and
1443 attach your USB cable. The Unix command "dmesg" should print
1444 it has found a new device. The environment variable usbtty
1445 can be set to gserial or cdc_acm to enable your device to
1446 appear to a USB host as a Linux gserial device or a
1447 Common Device Class Abstract Control Model serial device.
1448 If you select usbtty = gserial you should be able to enumerate
1450 # modprobe usbserial vendor=0xVendorID product=0xProductID
1451 else if using cdc_acm, simply setting the environment
1452 variable usbtty to be cdc_acm should suffice. The following
1453 might be defined in YourBoardName.h
1456 Define this to build a UDC device
1459 Define this to have a tty type of device available to
1460 talk to the UDC device
1463 Define this to enable the high speed support for usb
1464 device and usbtty. If this feature is enabled, a routine
1465 int is_usbd_high_speed(void)
1466 also needs to be defined by the driver to dynamically poll
1467 whether the enumeration has succeded at high speed or full
1470 CONFIG_SYS_CONSOLE_IS_IN_ENV
1471 Define this if you want stdin, stdout &/or stderr to
1475 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1476 Derive USB clock from external clock "blah"
1477 - CONFIG_SYS_USB_EXTC_CLK 0x02
1479 If you have a USB-IF assigned VendorID then you may wish to
1480 define your own vendor specific values either in BoardName.h
1481 or directly in usbd_vendor_info.h. If you don't define
1482 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1483 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1484 should pretend to be a Linux device to it's target host.
1486 CONFIG_USBD_MANUFACTURER
1487 Define this string as the name of your company for
1488 - CONFIG_USBD_MANUFACTURER "my company"
1490 CONFIG_USBD_PRODUCT_NAME
1491 Define this string as the name of your product
1492 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1494 CONFIG_USBD_VENDORID
1495 Define this as your assigned Vendor ID from the USB
1496 Implementors Forum. This *must* be a genuine Vendor ID
1497 to avoid polluting the USB namespace.
1498 - CONFIG_USBD_VENDORID 0xFFFF
1500 CONFIG_USBD_PRODUCTID
1501 Define this as the unique Product ID
1503 - CONFIG_USBD_PRODUCTID 0xFFFF
1505 - ULPI Layer Support:
1506 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1507 the generic ULPI layer. The generic layer accesses the ULPI PHY
1508 via the platform viewport, so you need both the genric layer and
1509 the viewport enabled. Currently only Chipidea/ARC based
1510 viewport is supported.
1511 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1512 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1513 If your ULPI phy needs a different reference clock than the
1514 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1515 the appropriate value in Hz.
1518 The MMC controller on the Intel PXA is supported. To
1519 enable this define CONFIG_MMC. The MMC can be
1520 accessed from the boot prompt by mapping the device
1521 to physical memory similar to flash. Command line is
1522 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1523 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1526 Support for Renesas on-chip MMCIF controller
1528 CONFIG_SH_MMCIF_ADDR
1529 Define the base address of MMCIF registers
1532 Define the clock frequency for MMCIF
1535 Enable the generic MMC driver
1537 CONFIG_SUPPORT_EMMC_BOOT
1538 Enable some additional features of the eMMC boot partitions.
1540 CONFIG_SUPPORT_EMMC_RPMB
1541 Enable the commands for reading, writing and programming the
1542 key for the Replay Protection Memory Block partition in eMMC.
1544 - USB Device Firmware Update (DFU) class support:
1545 CONFIG_USB_FUNCTION_DFU
1546 This enables the USB portion of the DFU USB class
1549 This enables the command "dfu" which is used to have
1550 U-Boot create a DFU class device via USB. This command
1551 requires that the "dfu_alt_info" environment variable be
1552 set and define the alt settings to expose to the host.
1555 This enables support for exposing (e)MMC devices via DFU.
1558 This enables support for exposing NAND devices via DFU.
1561 This enables support for exposing RAM via DFU.
1562 Note: DFU spec refer to non-volatile memory usage, but
1563 allow usages beyond the scope of spec - here RAM usage,
1564 one that would help mostly the developer.
1566 CONFIG_SYS_DFU_DATA_BUF_SIZE
1567 Dfu transfer uses a buffer before writing data to the
1568 raw storage device. Make the size (in bytes) of this buffer
1569 configurable. The size of this buffer is also configurable
1570 through the "dfu_bufsiz" environment variable.
1572 CONFIG_SYS_DFU_MAX_FILE_SIZE
1573 When updating files rather than the raw storage device,
1574 we use a static buffer to copy the file into and then write
1575 the buffer once we've been given the whole file. Define
1576 this to the maximum filesize (in bytes) for the buffer.
1577 Default is 4 MiB if undefined.
1579 DFU_DEFAULT_POLL_TIMEOUT
1580 Poll timeout [ms], is the timeout a device can send to the
1581 host. The host must wait for this timeout before sending
1582 a subsequent DFU_GET_STATUS request to the device.
1584 DFU_MANIFEST_POLL_TIMEOUT
1585 Poll timeout [ms], which the device sends to the host when
1586 entering dfuMANIFEST state. Host waits this timeout, before
1587 sending again an USB request to the device.
1589 - USB Device Android Fastboot support:
1590 CONFIG_USB_FUNCTION_FASTBOOT
1591 This enables the USB part of the fastboot gadget
1594 This enables the command "fastboot" which enables the Android
1595 fastboot mode for the platform's USB device. Fastboot is a USB
1596 protocol for downloading images, flashing and device control
1597 used on Android devices.
1598 See doc/README.android-fastboot for more information.
1600 CONFIG_ANDROID_BOOT_IMAGE
1601 This enables support for booting images which use the Android
1602 image format header.
1604 CONFIG_FASTBOOT_BUF_ADDR
1605 The fastboot protocol requires a large memory buffer for
1606 downloads. Define this to the starting RAM address to use for
1609 CONFIG_FASTBOOT_BUF_SIZE
1610 The fastboot protocol requires a large memory buffer for
1611 downloads. This buffer should be as large as possible for a
1612 platform. Define this to the size available RAM for fastboot.
1614 CONFIG_FASTBOOT_FLASH
1615 The fastboot protocol includes a "flash" command for writing
1616 the downloaded image to a non-volatile storage device. Define
1617 this to enable the "fastboot flash" command.
1619 CONFIG_FASTBOOT_FLASH_MMC_DEV
1620 The fastboot "flash" command requires additional information
1621 regarding the non-volatile storage device. Define this to
1622 the eMMC device that fastboot should use to store the image.
1624 CONFIG_FASTBOOT_GPT_NAME
1625 The fastboot "flash" command supports writing the downloaded
1626 image to the Protective MBR and the Primary GUID Partition
1627 Table. (Additionally, this downloaded image is post-processed
1628 to generate and write the Backup GUID Partition Table.)
1629 This occurs when the specified "partition name" on the
1630 "fastboot flash" command line matches this value.
1631 The default is "gpt" if undefined.
1633 CONFIG_FASTBOOT_MBR_NAME
1634 The fastboot "flash" command supports writing the downloaded
1636 This occurs when the "partition name" specified on the
1637 "fastboot flash" command line matches this value.
1638 If not defined the default value "mbr" is used.
1640 - Journaling Flash filesystem support:
1642 Define these for a default partition on a NAND device
1644 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1645 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1646 Define these for a default partition on a NOR device
1648 - FAT(File Allocation Table) filesystem write function support:
1651 Define this to enable support for saving memory data as a
1652 file in FAT formatted partition.
1654 This will also enable the command "fatwrite" enabling the
1655 user to write files to FAT.
1657 CBFS (Coreboot Filesystem) support
1660 Define this to enable support for reading from a Coreboot
1661 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1664 - FAT(File Allocation Table) filesystem cluster size:
1665 CONFIG_FS_FAT_MAX_CLUSTSIZE
1667 Define the max cluster size for fat operations else
1668 a default value of 65536 will be defined.
1671 See Kconfig help for available keyboard drivers.
1675 Define this to enable a custom keyboard support.
1676 This simply calls drv_keyboard_init() which must be
1677 defined in your board-specific files. This option is deprecated
1678 and is only used by novena. For new boards, use driver model
1684 Define this to enable video support (for output to
1687 CONFIG_VIDEO_CT69000
1689 Enable Chips & Technologies 69000 Video chip
1691 CONFIG_VIDEO_SMI_LYNXEM
1692 Enable Silicon Motion SMI 712/710/810 Video chip. The
1693 video output is selected via environment 'videoout'
1694 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1697 For the CT69000 and SMI_LYNXEM drivers, videomode is
1698 selected via environment 'videomode'. Two different ways
1700 - "videomode=num" 'num' is a standard LiLo mode numbers.
1701 Following standard modes are supported (* is default):
1703 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1704 -------------+---------------------------------------------
1705 8 bits | 0x301* 0x303 0x305 0x161 0x307
1706 15 bits | 0x310 0x313 0x316 0x162 0x319
1707 16 bits | 0x311 0x314 0x317 0x163 0x31A
1708 24 bits | 0x312 0x315 0x318 ? 0x31B
1709 -------------+---------------------------------------------
1710 (i.e. setenv videomode 317; saveenv; reset;)
1712 - "videomode=bootargs" all the video parameters are parsed
1713 from the bootargs. (See drivers/video/videomodes.c)
1716 CONFIG_VIDEO_SED13806
1717 Enable Epson SED13806 driver. This driver supports 8bpp
1718 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1719 or CONFIG_VIDEO_SED13806_16BPP
1722 Enable the Freescale DIU video driver. Reference boards for
1723 SOCs that have a DIU should define this macro to enable DIU
1724 support, and should also define these other macros:
1730 CONFIG_VIDEO_SW_CURSOR
1731 CONFIG_VGA_AS_SINGLE_DEVICE
1733 CONFIG_VIDEO_BMP_LOGO
1735 The DIU driver will look for the 'video-mode' environment
1736 variable, and if defined, enable the DIU as a console during
1737 boot. See the documentation file doc/README.video for a
1738 description of this variable.
1740 - LCD Support: CONFIG_LCD
1742 Define this to enable LCD support (for output to LCD
1743 display); also select one of the supported displays
1744 by defining one of these:
1748 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1750 CONFIG_NEC_NL6448AC33:
1752 NEC NL6448AC33-18. Active, color, single scan.
1754 CONFIG_NEC_NL6448BC20
1756 NEC NL6448BC20-08. 6.5", 640x480.
1757 Active, color, single scan.
1759 CONFIG_NEC_NL6448BC33_54
1761 NEC NL6448BC33-54. 10.4", 640x480.
1762 Active, color, single scan.
1766 Sharp 320x240. Active, color, single scan.
1767 It isn't 16x9, and I am not sure what it is.
1769 CONFIG_SHARP_LQ64D341
1771 Sharp LQ64D341 display, 640x480.
1772 Active, color, single scan.
1776 HLD1045 display, 640x480.
1777 Active, color, single scan.
1781 Optrex CBL50840-2 NF-FW 99 22 M5
1783 Hitachi LMG6912RPFC-00T
1787 320x240. Black & white.
1789 Normally display is black on white background; define
1790 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1792 CONFIG_LCD_ALIGNMENT
1794 Normally the LCD is page-aligned (typically 4KB). If this is
1795 defined then the LCD will be aligned to this value instead.
1796 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1797 here, since it is cheaper to change data cache settings on
1798 a per-section basis.
1800 CONFIG_CONSOLE_SCROLL_LINES
1802 When the console need to be scrolled, this is the number of
1803 lines to scroll by. It defaults to 1. Increasing this makes
1804 the console jump but can help speed up operation when scrolling
1809 Sometimes, for example if the display is mounted in portrait
1810 mode or even if it's mounted landscape but rotated by 180degree,
1811 we need to rotate our content of the display relative to the
1812 framebuffer, so that user can read the messages which are
1814 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1815 initialized with a given rotation from "vl_rot" out of
1816 "vidinfo_t" which is provided by the board specific code.
1817 The value for vl_rot is coded as following (matching to
1818 fbcon=rotate:<n> linux-kernel commandline):
1819 0 = no rotation respectively 0 degree
1820 1 = 90 degree rotation
1821 2 = 180 degree rotation
1822 3 = 270 degree rotation
1824 If CONFIG_LCD_ROTATION is not defined, the console will be
1825 initialized with 0degree rotation.
1829 Support drawing of RLE8-compressed bitmaps on the LCD.
1833 Enables an 'i2c edid' command which can read EDID
1834 information over I2C from an attached LCD display.
1836 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1838 If this option is set, the environment is checked for
1839 a variable "splashimage". If found, the usual display
1840 of logo, copyright and system information on the LCD
1841 is suppressed and the BMP image at the address
1842 specified in "splashimage" is loaded instead. The
1843 console is redirected to the "nulldev", too. This
1844 allows for a "silent" boot where a splash screen is
1845 loaded very quickly after power-on.
1847 CONFIG_SPLASHIMAGE_GUARD
1849 If this option is set, then U-Boot will prevent the environment
1850 variable "splashimage" from being set to a problematic address
1851 (see doc/README.displaying-bmps).
1852 This option is useful for targets where, due to alignment
1853 restrictions, an improperly aligned BMP image will cause a data
1854 abort. If you think you will not have problems with unaligned
1855 accesses (for example because your toolchain prevents them)
1856 there is no need to set this option.
1858 CONFIG_SPLASH_SCREEN_ALIGN
1860 If this option is set the splash image can be freely positioned
1861 on the screen. Environment variable "splashpos" specifies the
1862 position as "x,y". If a positive number is given it is used as
1863 number of pixel from left/top. If a negative number is given it
1864 is used as number of pixel from right/bottom. You can also
1865 specify 'm' for centering the image.
1868 setenv splashpos m,m
1869 => image at center of screen
1871 setenv splashpos 30,20
1872 => image at x = 30 and y = 20
1874 setenv splashpos -10,m
1875 => vertically centered image
1876 at x = dspWidth - bmpWidth - 9
1878 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1880 If this option is set, additionally to standard BMP
1881 images, gzipped BMP images can be displayed via the
1882 splashscreen support or the bmp command.
1884 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1886 If this option is set, 8-bit RLE compressed BMP images
1887 can be displayed via the splashscreen support or the
1890 - Do compressing for memory range:
1893 If this option is set, it would use zlib deflate method
1894 to compress the specified memory at its best effort.
1896 - Compression support:
1899 Enabled by default to support gzip compressed images.
1903 If this option is set, support for bzip2 compressed
1904 images is included. If not, only uncompressed and gzip
1905 compressed images are supported.
1907 NOTE: the bzip2 algorithm requires a lot of RAM, so
1908 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1913 If this option is set, support for lzma compressed
1916 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1917 requires an amount of dynamic memory that is given by the
1920 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1922 Where lc and lp stand for, respectively, Literal context bits
1923 and Literal pos bits.
1925 This value is upper-bounded by 14MB in the worst case. Anyway,
1926 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1927 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1928 a very small buffer.
1930 Use the lzmainfo tool to determinate the lc and lp values and
1931 then calculate the amount of needed dynamic memory (ensuring
1932 the appropriate CONFIG_SYS_MALLOC_LEN value).
1936 If this option is set, support for LZO compressed images
1942 The address of PHY on MII bus.
1944 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1946 The clock frequency of the MII bus
1950 If this option is set, support for speed/duplex
1951 detection of gigabit PHY is included.
1953 CONFIG_PHY_RESET_DELAY
1955 Some PHY like Intel LXT971A need extra delay after
1956 reset before any MII register access is possible.
1957 For such PHY, set this option to the usec delay
1958 required. (minimum 300usec for LXT971A)
1960 CONFIG_PHY_CMD_DELAY (ppc4xx)
1962 Some PHY like Intel LXT971A need extra delay after
1963 command issued before MII status register can be read
1968 Define a default value for the IP address to use for
1969 the default Ethernet interface, in case this is not
1970 determined through e.g. bootp.
1971 (Environment variable "ipaddr")
1973 - Server IP address:
1976 Defines a default value for the IP address of a TFTP
1977 server to contact when using the "tftboot" command.
1978 (Environment variable "serverip")
1980 CONFIG_KEEP_SERVERADDR
1982 Keeps the server's MAC address, in the env 'serveraddr'
1983 for passing to bootargs (like Linux's netconsole option)
1985 - Gateway IP address:
1988 Defines a default value for the IP address of the
1989 default router where packets to other networks are
1991 (Environment variable "gatewayip")
1996 Defines a default value for the subnet mask (or
1997 routing prefix) which is used to determine if an IP
1998 address belongs to the local subnet or needs to be
1999 forwarded through a router.
2000 (Environment variable "netmask")
2002 - Multicast TFTP Mode:
2005 Defines whether you want to support multicast TFTP as per
2006 rfc-2090; for example to work with atftp. Lets lots of targets
2007 tftp down the same boot image concurrently. Note: the Ethernet
2008 driver in use must provide a function: mcast() to join/leave a
2011 - BOOTP Recovery Mode:
2012 CONFIG_BOOTP_RANDOM_DELAY
2014 If you have many targets in a network that try to
2015 boot using BOOTP, you may want to avoid that all
2016 systems send out BOOTP requests at precisely the same
2017 moment (which would happen for instance at recovery
2018 from a power failure, when all systems will try to
2019 boot, thus flooding the BOOTP server. Defining
2020 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2021 inserted before sending out BOOTP requests. The
2022 following delays are inserted then:
2024 1st BOOTP request: delay 0 ... 1 sec
2025 2nd BOOTP request: delay 0 ... 2 sec
2026 3rd BOOTP request: delay 0 ... 4 sec
2028 BOOTP requests: delay 0 ... 8 sec
2030 CONFIG_BOOTP_ID_CACHE_SIZE
2032 BOOTP packets are uniquely identified using a 32-bit ID. The
2033 server will copy the ID from client requests to responses and
2034 U-Boot will use this to determine if it is the destination of
2035 an incoming response. Some servers will check that addresses
2036 aren't in use before handing them out (usually using an ARP
2037 ping) and therefore take up to a few hundred milliseconds to
2038 respond. Network congestion may also influence the time it
2039 takes for a response to make it back to the client. If that
2040 time is too long, U-Boot will retransmit requests. In order
2041 to allow earlier responses to still be accepted after these
2042 retransmissions, U-Boot's BOOTP client keeps a small cache of
2043 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2044 cache. The default is to keep IDs for up to four outstanding
2045 requests. Increasing this will allow U-Boot to accept offers
2046 from a BOOTP client in networks with unusually high latency.
2048 - DHCP Advanced Options:
2049 You can fine tune the DHCP functionality by defining
2050 CONFIG_BOOTP_* symbols:
2052 CONFIG_BOOTP_SUBNETMASK
2053 CONFIG_BOOTP_GATEWAY
2054 CONFIG_BOOTP_HOSTNAME
2055 CONFIG_BOOTP_NISDOMAIN
2056 CONFIG_BOOTP_BOOTPATH
2057 CONFIG_BOOTP_BOOTFILESIZE
2060 CONFIG_BOOTP_SEND_HOSTNAME
2061 CONFIG_BOOTP_NTPSERVER
2062 CONFIG_BOOTP_TIMEOFFSET
2063 CONFIG_BOOTP_VENDOREX
2064 CONFIG_BOOTP_MAY_FAIL
2066 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2067 environment variable, not the BOOTP server.
2069 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2070 after the configured retry count, the call will fail
2071 instead of starting over. This can be used to fail over
2072 to Link-local IP address configuration if the DHCP server
2075 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2076 serverip from a DHCP server, it is possible that more
2077 than one DNS serverip is offered to the client.
2078 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2079 serverip will be stored in the additional environment
2080 variable "dnsip2". The first DNS serverip is always
2081 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2084 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2085 to do a dynamic update of a DNS server. To do this, they
2086 need the hostname of the DHCP requester.
2087 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2088 of the "hostname" environment variable is passed as
2089 option 12 to the DHCP server.
2091 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2093 A 32bit value in microseconds for a delay between
2094 receiving a "DHCP Offer" and sending the "DHCP Request".
2095 This fixes a problem with certain DHCP servers that don't
2096 respond 100% of the time to a "DHCP request". E.g. On an
2097 AT91RM9200 processor running at 180MHz, this delay needed
2098 to be *at least* 15,000 usec before a Windows Server 2003
2099 DHCP server would reply 100% of the time. I recommend at
2100 least 50,000 usec to be safe. The alternative is to hope
2101 that one of the retries will be successful but note that
2102 the DHCP timeout and retry process takes a longer than
2105 - Link-local IP address negotiation:
2106 Negotiate with other link-local clients on the local network
2107 for an address that doesn't require explicit configuration.
2108 This is especially useful if a DHCP server cannot be guaranteed
2109 to exist in all environments that the device must operate.
2111 See doc/README.link-local for more information.
2114 CONFIG_CDP_DEVICE_ID
2116 The device id used in CDP trigger frames.
2118 CONFIG_CDP_DEVICE_ID_PREFIX
2120 A two character string which is prefixed to the MAC address
2125 A printf format string which contains the ascii name of
2126 the port. Normally is set to "eth%d" which sets
2127 eth0 for the first Ethernet, eth1 for the second etc.
2129 CONFIG_CDP_CAPABILITIES
2131 A 32bit integer which indicates the device capabilities;
2132 0x00000010 for a normal host which does not forwards.
2136 An ascii string containing the version of the software.
2140 An ascii string containing the name of the platform.
2144 A 32bit integer sent on the trigger.
2146 CONFIG_CDP_POWER_CONSUMPTION
2148 A 16bit integer containing the power consumption of the
2149 device in .1 of milliwatts.
2151 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2153 A byte containing the id of the VLAN.
2155 - Status LED: CONFIG_STATUS_LED
2157 Several configurations allow to display the current
2158 status using a LED. For instance, the LED will blink
2159 fast while running U-Boot code, stop blinking as
2160 soon as a reply to a BOOTP request was received, and
2161 start blinking slow once the Linux kernel is running
2162 (supported by a status LED driver in the Linux
2163 kernel). Defining CONFIG_STATUS_LED enables this
2169 The status LED can be connected to a GPIO pin.
2170 In such cases, the gpio_led driver can be used as a
2171 status LED backend implementation. Define CONFIG_GPIO_LED
2172 to include the gpio_led driver in the U-Boot binary.
2174 CONFIG_GPIO_LED_INVERTED_TABLE
2175 Some GPIO connected LEDs may have inverted polarity in which
2176 case the GPIO high value corresponds to LED off state and
2177 GPIO low value corresponds to LED on state.
2178 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2179 with a list of GPIO LEDs that have inverted polarity.
2181 - CAN Support: CONFIG_CAN_DRIVER
2183 Defining CONFIG_CAN_DRIVER enables CAN driver support
2184 on those systems that support this (optional)
2185 feature, like the TQM8xxL modules.
2187 - I2C Support: CONFIG_SYS_I2C
2189 This enable the NEW i2c subsystem, and will allow you to use
2190 i2c commands at the u-boot command line (as long as you set
2191 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2192 based realtime clock chips or other i2c devices. See
2193 common/cmd_i2c.c for a description of the command line
2196 ported i2c driver to the new framework:
2197 - drivers/i2c/soft_i2c.c:
2198 - activate first bus with CONFIG_SYS_I2C_SOFT define
2199 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2200 for defining speed and slave address
2201 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2202 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2203 for defining speed and slave address
2204 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2205 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2206 for defining speed and slave address
2207 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2208 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2209 for defining speed and slave address
2211 - drivers/i2c/fsl_i2c.c:
2212 - activate i2c driver with CONFIG_SYS_I2C_FSL
2213 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2214 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2215 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2217 - If your board supports a second fsl i2c bus, define
2218 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2219 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2220 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2223 - drivers/i2c/tegra_i2c.c:
2224 - activate this driver with CONFIG_SYS_I2C_TEGRA
2225 - This driver adds 4 i2c buses with a fix speed from
2226 100000 and the slave addr 0!
2228 - drivers/i2c/ppc4xx_i2c.c
2229 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2230 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2231 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2233 - drivers/i2c/i2c_mxc.c
2234 - activate this driver with CONFIG_SYS_I2C_MXC
2235 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2236 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2237 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2238 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2239 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2240 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2241 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2242 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2243 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2244 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2245 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2246 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2247 If those defines are not set, default value is 100000
2248 for speed, and 0 for slave.
2250 - drivers/i2c/rcar_i2c.c:
2251 - activate this driver with CONFIG_SYS_I2C_RCAR
2252 - This driver adds 4 i2c buses
2254 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2255 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2256 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2257 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2258 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2259 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2260 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2261 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2262 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2264 - drivers/i2c/sh_i2c.c:
2265 - activate this driver with CONFIG_SYS_I2C_SH
2266 - This driver adds from 2 to 5 i2c buses
2268 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2269 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2270 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2271 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2272 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2273 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2274 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2275 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2276 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2277 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2278 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2280 - drivers/i2c/omap24xx_i2c.c
2281 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2282 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2283 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2284 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2285 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2286 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2287 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2288 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2289 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2290 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2291 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2293 - drivers/i2c/zynq_i2c.c
2294 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2295 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2296 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2298 - drivers/i2c/s3c24x0_i2c.c:
2299 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2300 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2301 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2302 with a fix speed from 100000 and the slave addr 0!
2304 - drivers/i2c/ihs_i2c.c
2305 - activate this driver with CONFIG_SYS_I2C_IHS
2306 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2307 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2308 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2309 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2310 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2311 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2312 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2313 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2314 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2315 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2316 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2317 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2318 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2319 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2320 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2321 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2322 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2323 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2324 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2325 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2326 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2330 CONFIG_SYS_NUM_I2C_BUSES
2331 Hold the number of i2c buses you want to use.
2333 CONFIG_SYS_I2C_DIRECT_BUS
2334 define this, if you don't use i2c muxes on your hardware.
2335 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2338 CONFIG_SYS_I2C_MAX_HOPS
2339 define how many muxes are maximal consecutively connected
2340 on one i2c bus. If you not use i2c muxes, omit this
2343 CONFIG_SYS_I2C_BUSES
2344 hold a list of buses you want to use, only used if
2345 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2346 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2347 CONFIG_SYS_NUM_I2C_BUSES = 9:
2349 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2350 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2351 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2352 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2353 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2354 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2355 {1, {I2C_NULL_HOP}}, \
2356 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2357 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2361 bus 0 on adapter 0 without a mux
2362 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2363 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2364 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2365 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2366 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2367 bus 6 on adapter 1 without a mux
2368 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2369 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2371 If you do not have i2c muxes on your board, omit this define.
2373 - Legacy I2C Support: CONFIG_HARD_I2C
2375 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2376 provides the following compelling advantages:
2378 - more than one i2c adapter is usable
2379 - approved multibus support
2380 - better i2c mux support
2382 ** Please consider updating your I2C driver now. **
2384 These enable legacy I2C serial bus commands. Defining
2385 CONFIG_HARD_I2C will include the appropriate I2C driver
2386 for the selected CPU.
2388 This will allow you to use i2c commands at the u-boot
2389 command line (as long as you set CONFIG_CMD_I2C in
2390 CONFIG_COMMANDS) and communicate with i2c based realtime
2391 clock chips. See common/cmd_i2c.c for a description of the
2392 command line interface.
2394 CONFIG_HARD_I2C selects a hardware I2C controller.
2396 There are several other quantities that must also be
2397 defined when you define CONFIG_HARD_I2C.
2399 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2400 to be the frequency (in Hz) at which you wish your i2c bus
2401 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2402 the CPU's i2c node address).
2404 Now, the u-boot i2c code for the mpc8xx
2405 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2406 and so its address should therefore be cleared to 0 (See,
2407 eg, MPC823e User's Manual p.16-473). So, set
2408 CONFIG_SYS_I2C_SLAVE to 0.
2410 CONFIG_SYS_I2C_INIT_MPC5XXX
2412 When a board is reset during an i2c bus transfer
2413 chips might think that the current transfer is still
2414 in progress. Reset the slave devices by sending start
2415 commands until the slave device responds.
2417 That's all that's required for CONFIG_HARD_I2C.
2419 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2420 then the following macros need to be defined (examples are
2421 from include/configs/lwmon.h):
2425 (Optional). Any commands necessary to enable the I2C
2426 controller or configure ports.
2428 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2432 (Only for MPC8260 CPU). The I/O port to use (the code
2433 assumes both bits are on the same port). Valid values
2434 are 0..3 for ports A..D.
2438 The code necessary to make the I2C data line active
2439 (driven). If the data line is open collector, this
2442 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2446 The code necessary to make the I2C data line tri-stated
2447 (inactive). If the data line is open collector, this
2450 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2454 Code that returns true if the I2C data line is high,
2457 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2461 If <bit> is true, sets the I2C data line high. If it
2462 is false, it clears it (low).
2464 eg: #define I2C_SDA(bit) \
2465 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2466 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2470 If <bit> is true, sets the I2C clock line high. If it
2471 is false, it clears it (low).
2473 eg: #define I2C_SCL(bit) \
2474 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2475 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2479 This delay is invoked four times per clock cycle so this
2480 controls the rate of data transfer. The data rate thus
2481 is 1 / (I2C_DELAY * 4). Often defined to be something
2484 #define I2C_DELAY udelay(2)
2486 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2488 If your arch supports the generic GPIO framework (asm/gpio.h),
2489 then you may alternatively define the two GPIOs that are to be
2490 used as SCL / SDA. Any of the previous I2C_xxx macros will
2491 have GPIO-based defaults assigned to them as appropriate.
2493 You should define these to the GPIO value as given directly to
2494 the generic GPIO functions.
2496 CONFIG_SYS_I2C_INIT_BOARD
2498 When a board is reset during an i2c bus transfer
2499 chips might think that the current transfer is still
2500 in progress. On some boards it is possible to access
2501 the i2c SCLK line directly, either by using the
2502 processor pin as a GPIO or by having a second pin
2503 connected to the bus. If this option is defined a
2504 custom i2c_init_board() routine in boards/xxx/board.c
2505 is run early in the boot sequence.
2507 CONFIG_SYS_I2C_BOARD_LATE_INIT
2509 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2510 defined a custom i2c_board_late_init() routine in
2511 boards/xxx/board.c is run AFTER the operations in i2c_init()
2512 is completed. This callpoint can be used to unreset i2c bus
2513 using CPU i2c controller register accesses for CPUs whose i2c
2514 controller provide such a method. It is called at the end of
2515 i2c_init() to allow i2c_init operations to setup the i2c bus
2516 controller on the CPU (e.g. setting bus speed & slave address).
2518 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2520 This option enables configuration of bi_iic_fast[] flags
2521 in u-boot bd_info structure based on u-boot environment
2522 variable "i2cfast". (see also i2cfast)
2524 CONFIG_I2C_MULTI_BUS
2526 This option allows the use of multiple I2C buses, each of which
2527 must have a controller. At any point in time, only one bus is
2528 active. To switch to a different bus, use the 'i2c dev' command.
2529 Note that bus numbering is zero-based.
2531 CONFIG_SYS_I2C_NOPROBES
2533 This option specifies a list of I2C devices that will be skipped
2534 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2535 is set, specify a list of bus-device pairs. Otherwise, specify
2536 a 1D array of device addresses
2539 #undef CONFIG_I2C_MULTI_BUS
2540 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2542 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2544 #define CONFIG_I2C_MULTI_BUS
2545 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2547 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2549 CONFIG_SYS_SPD_BUS_NUM
2551 If defined, then this indicates the I2C bus number for DDR SPD.
2552 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2554 CONFIG_SYS_RTC_BUS_NUM
2556 If defined, then this indicates the I2C bus number for the RTC.
2557 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2559 CONFIG_SYS_DTT_BUS_NUM
2561 If defined, then this indicates the I2C bus number for the DTT.
2562 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2564 CONFIG_SYS_I2C_DTT_ADDR:
2566 If defined, specifies the I2C address of the DTT device.
2567 If not defined, then U-Boot uses predefined value for
2568 specified DTT device.
2570 CONFIG_SOFT_I2C_READ_REPEATED_START
2572 defining this will force the i2c_read() function in
2573 the soft_i2c driver to perform an I2C repeated start
2574 between writing the address pointer and reading the
2575 data. If this define is omitted the default behaviour
2576 of doing a stop-start sequence will be used. Most I2C
2577 devices can use either method, but some require one or
2580 - SPI Support: CONFIG_SPI
2582 Enables SPI driver (so far only tested with
2583 SPI EEPROM, also an instance works with Crystal A/D and
2584 D/As on the SACSng board)
2588 Enables the driver for SPI controller on SuperH. Currently
2589 only SH7757 is supported.
2593 Enables a software (bit-bang) SPI driver rather than
2594 using hardware support. This is a general purpose
2595 driver that only requires three general I/O port pins
2596 (two outputs, one input) to function. If this is
2597 defined, the board configuration must define several
2598 SPI configuration items (port pins to use, etc). For
2599 an example, see include/configs/sacsng.h.
2603 Enables a hardware SPI driver for general-purpose reads
2604 and writes. As with CONFIG_SOFT_SPI, the board configuration
2605 must define a list of chip-select function pointers.
2606 Currently supported on some MPC8xxx processors. For an
2607 example, see include/configs/mpc8349emds.h.
2611 Enables the driver for the SPI controllers on i.MX and MXC
2612 SoCs. Currently i.MX31/35/51 are supported.
2614 CONFIG_SYS_SPI_MXC_WAIT
2615 Timeout for waiting until spi transfer completed.
2616 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2618 - FPGA Support: CONFIG_FPGA
2620 Enables FPGA subsystem.
2622 CONFIG_FPGA_<vendor>
2624 Enables support for specific chip vendors.
2627 CONFIG_FPGA_<family>
2629 Enables support for FPGA family.
2630 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2634 Specify the number of FPGA devices to support.
2636 CONFIG_CMD_FPGA_LOADMK
2638 Enable support for fpga loadmk command
2640 CONFIG_CMD_FPGA_LOADP
2642 Enable support for fpga loadp command - load partial bitstream
2644 CONFIG_CMD_FPGA_LOADBP
2646 Enable support for fpga loadbp command - load partial bitstream
2649 CONFIG_SYS_FPGA_PROG_FEEDBACK
2651 Enable printing of hash marks during FPGA configuration.
2653 CONFIG_SYS_FPGA_CHECK_BUSY
2655 Enable checks on FPGA configuration interface busy
2656 status by the configuration function. This option
2657 will require a board or device specific function to
2662 If defined, a function that provides delays in the FPGA
2663 configuration driver.
2665 CONFIG_SYS_FPGA_CHECK_CTRLC
2666 Allow Control-C to interrupt FPGA configuration
2668 CONFIG_SYS_FPGA_CHECK_ERROR
2670 Check for configuration errors during FPGA bitfile
2671 loading. For example, abort during Virtex II
2672 configuration if the INIT_B line goes low (which
2673 indicated a CRC error).
2675 CONFIG_SYS_FPGA_WAIT_INIT
2677 Maximum time to wait for the INIT_B line to de-assert
2678 after PROB_B has been de-asserted during a Virtex II
2679 FPGA configuration sequence. The default time is 500
2682 CONFIG_SYS_FPGA_WAIT_BUSY
2684 Maximum time to wait for BUSY to de-assert during
2685 Virtex II FPGA configuration. The default is 5 ms.
2687 CONFIG_SYS_FPGA_WAIT_CONFIG
2689 Time to wait after FPGA configuration. The default is
2692 - Configuration Management:
2695 Some SoCs need special image types (e.g. U-Boot binary
2696 with a special header) as build targets. By defining
2697 CONFIG_BUILD_TARGET in the SoC / board header, this
2698 special image will be automatically built upon calling
2703 If defined, this string will be added to the U-Boot
2704 version information (U_BOOT_VERSION)
2706 - Vendor Parameter Protection:
2708 U-Boot considers the values of the environment
2709 variables "serial#" (Board Serial Number) and
2710 "ethaddr" (Ethernet Address) to be parameters that
2711 are set once by the board vendor / manufacturer, and
2712 protects these variables from casual modification by
2713 the user. Once set, these variables are read-only,
2714 and write or delete attempts are rejected. You can
2715 change this behaviour:
2717 If CONFIG_ENV_OVERWRITE is #defined in your config
2718 file, the write protection for vendor parameters is
2719 completely disabled. Anybody can change or delete
2722 Alternatively, if you define _both_ an ethaddr in the
2723 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2724 Ethernet address is installed in the environment,
2725 which can be changed exactly ONCE by the user. [The
2726 serial# is unaffected by this, i. e. it remains
2729 The same can be accomplished in a more flexible way
2730 for any variable by configuring the type of access
2731 to allow for those variables in the ".flags" variable
2732 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2737 Define this variable to enable the reservation of
2738 "protected RAM", i. e. RAM which is not overwritten
2739 by U-Boot. Define CONFIG_PRAM to hold the number of
2740 kB you want to reserve for pRAM. You can overwrite
2741 this default value by defining an environment
2742 variable "pram" to the number of kB you want to
2743 reserve. Note that the board info structure will
2744 still show the full amount of RAM. If pRAM is
2745 reserved, a new environment variable "mem" will
2746 automatically be defined to hold the amount of
2747 remaining RAM in a form that can be passed as boot
2748 argument to Linux, for instance like that:
2750 setenv bootargs ... mem=\${mem}
2753 This way you can tell Linux not to use this memory,
2754 either, which results in a memory region that will
2755 not be affected by reboots.
2757 *WARNING* If your board configuration uses automatic
2758 detection of the RAM size, you must make sure that
2759 this memory test is non-destructive. So far, the
2760 following board configurations are known to be
2763 IVMS8, IVML24, SPD8xx, TQM8xxL,
2764 HERMES, IP860, RPXlite, LWMON,
2767 - Access to physical memory region (> 4GB)
2768 Some basic support is provided for operations on memory not
2769 normally accessible to U-Boot - e.g. some architectures
2770 support access to more than 4GB of memory on 32-bit
2771 machines using physical address extension or similar.
2772 Define CONFIG_PHYSMEM to access this basic support, which
2773 currently only supports clearing the memory.
2778 Define this variable to stop the system in case of a
2779 fatal error, so that you have to reset it manually.
2780 This is probably NOT a good idea for an embedded
2781 system where you want the system to reboot
2782 automatically as fast as possible, but it may be
2783 useful during development since you can try to debug
2784 the conditions that lead to the situation.
2786 CONFIG_NET_RETRY_COUNT
2788 This variable defines the number of retries for
2789 network operations like ARP, RARP, TFTP, or BOOTP
2790 before giving up the operation. If not defined, a
2791 default value of 5 is used.
2795 Timeout waiting for an ARP reply in milliseconds.
2799 Timeout in milliseconds used in NFS protocol.
2800 If you encounter "ERROR: Cannot umount" in nfs command,
2801 try longer timeout such as
2802 #define CONFIG_NFS_TIMEOUT 10000UL
2804 - Command Interpreter:
2805 CONFIG_AUTO_COMPLETE
2807 Enable auto completion of commands using TAB.
2809 CONFIG_SYS_PROMPT_HUSH_PS2
2811 This defines the secondary prompt string, which is
2812 printed when the command interpreter needs more input
2813 to complete a command. Usually "> ".
2817 In the current implementation, the local variables
2818 space and global environment variables space are
2819 separated. Local variables are those you define by
2820 simply typing `name=value'. To access a local
2821 variable later on, you have write `$name' or
2822 `${name}'; to execute the contents of a variable
2823 directly type `$name' at the command prompt.
2825 Global environment variables are those you use
2826 setenv/printenv to work with. To run a command stored
2827 in such a variable, you need to use the run command,
2828 and you must not use the '$' sign to access them.
2830 To store commands and special characters in a
2831 variable, please use double quotation marks
2832 surrounding the whole text of the variable, instead
2833 of the backslashes before semicolons and special
2836 - Command Line Editing and History:
2837 CONFIG_CMDLINE_EDITING
2839 Enable editing and History functions for interactive
2840 command line input operations
2842 - Command Line PS1/PS2 support:
2843 CONFIG_CMDLINE_PS_SUPPORT
2845 Enable support for changing the command prompt string
2846 at run-time. Only static string is supported so far.
2847 The string is obtained from environment variables PS1
2850 - Default Environment:
2851 CONFIG_EXTRA_ENV_SETTINGS
2853 Define this to contain any number of null terminated
2854 strings (variable = value pairs) that will be part of
2855 the default environment compiled into the boot image.
2857 For example, place something like this in your
2858 board's config file:
2860 #define CONFIG_EXTRA_ENV_SETTINGS \
2864 Warning: This method is based on knowledge about the
2865 internal format how the environment is stored by the
2866 U-Boot code. This is NOT an official, exported
2867 interface! Although it is unlikely that this format
2868 will change soon, there is no guarantee either.
2869 You better know what you are doing here.
2871 Note: overly (ab)use of the default environment is
2872 discouraged. Make sure to check other ways to preset
2873 the environment like the "source" command or the
2876 CONFIG_ENV_VARS_UBOOT_CONFIG
2878 Define this in order to add variables describing the
2879 U-Boot build configuration to the default environment.
2880 These will be named arch, cpu, board, vendor, and soc.
2882 Enabling this option will cause the following to be defined:
2890 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2892 Define this in order to add variables describing certain
2893 run-time determined information about the hardware to the
2894 environment. These will be named board_name, board_rev.
2896 CONFIG_DELAY_ENVIRONMENT
2898 Normally the environment is loaded when the board is
2899 initialised so that it is available to U-Boot. This inhibits
2900 that so that the environment is not available until
2901 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2902 this is instead controlled by the value of
2903 /config/load-environment.
2905 - Parallel Flash support:
2908 Traditionally U-Boot was run on systems with parallel NOR
2909 flash. This option is used to disable support for parallel NOR
2910 flash. This option should be defined if the board does not have
2913 If this option is not defined one of the generic flash drivers
2914 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2915 selected or the board must provide an implementation of the
2916 flash API (see include/flash.h).
2918 - DataFlash Support:
2919 CONFIG_HAS_DATAFLASH
2921 Defining this option enables DataFlash features and
2922 allows to read/write in Dataflash via the standard
2925 - Serial Flash support
2928 Defining this option enables SPI flash commands
2929 'sf probe/read/write/erase/update'.
2931 Usage requires an initial 'probe' to define the serial
2932 flash parameters, followed by read/write/erase/update
2935 The following defaults may be provided by the platform
2936 to handle the common case when only a single serial
2937 flash is present on the system.
2939 CONFIG_SF_DEFAULT_BUS Bus identifier
2940 CONFIG_SF_DEFAULT_CS Chip-select
2941 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2942 CONFIG_SF_DEFAULT_SPEED in Hz
2946 Define this option to include a destructive SPI flash
2949 CONFIG_SF_DUAL_FLASH Dual flash memories
2951 Define this option to use dual flash support where two flash
2952 memories can be connected with a given cs line.
2953 Currently Xilinx Zynq qspi supports these type of connections.
2955 - SystemACE Support:
2958 Adding this option adds support for Xilinx SystemACE
2959 chips attached via some sort of local bus. The address
2960 of the chip must also be defined in the
2961 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2963 #define CONFIG_SYSTEMACE
2964 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2966 When SystemACE support is added, the "ace" device type
2967 becomes available to the fat commands, i.e. fatls.
2969 - TFTP Fixed UDP Port:
2972 If this is defined, the environment variable tftpsrcp
2973 is used to supply the TFTP UDP source port value.
2974 If tftpsrcp isn't defined, the normal pseudo-random port
2975 number generator is used.
2977 Also, the environment variable tftpdstp is used to supply
2978 the TFTP UDP destination port value. If tftpdstp isn't
2979 defined, the normal port 69 is used.
2981 The purpose for tftpsrcp is to allow a TFTP server to
2982 blindly start the TFTP transfer using the pre-configured
2983 target IP address and UDP port. This has the effect of
2984 "punching through" the (Windows XP) firewall, allowing
2985 the remainder of the TFTP transfer to proceed normally.
2986 A better solution is to properly configure the firewall,
2987 but sometimes that is not allowed.
2992 This enables a generic 'hash' command which can produce
2993 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2997 Enable the hash verify command (hash -v). This adds to code
3000 CONFIG_SHA1 - This option enables support of hashing using SHA1
3001 algorithm. The hash is calculated in software.
3002 CONFIG_SHA256 - This option enables support of hashing using
3003 SHA256 algorithm. The hash is calculated in software.
3004 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3005 for SHA1/SHA256 hashing.
3006 This affects the 'hash' command and also the
3007 hash_lookup_algo() function.
3008 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3009 hardware-acceleration for SHA1/SHA256 progressive hashing.
3010 Data can be streamed in a block at a time and the hashing
3011 is performed in hardware.
3013 Note: There is also a sha1sum command, which should perhaps
3014 be deprecated in favour of 'hash sha1'.
3016 - Freescale i.MX specific commands:
3017 CONFIG_CMD_HDMIDETECT
3018 This enables 'hdmidet' command which returns true if an
3019 HDMI monitor is detected. This command is i.MX 6 specific.
3022 This enables the 'bmode' (bootmode) command for forcing
3023 a boot from specific media.
3025 This is useful for forcing the ROM's usb downloader to
3026 activate upon a watchdog reset which is nice when iterating
3027 on U-Boot. Using the reset button or running bmode normal
3028 will set it back to normal. This command currently
3029 supports i.MX53 and i.MX6.
3031 - bootcount support:
3032 CONFIG_BOOTCOUNT_LIMIT
3034 This enables the bootcounter support, see:
3035 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3038 enable special bootcounter support on at91sam9xe based boards.
3040 enable special bootcounter support on blackfin based boards.
3042 enable special bootcounter support on da850 based boards.
3043 CONFIG_BOOTCOUNT_RAM
3044 enable support for the bootcounter in RAM
3045 CONFIG_BOOTCOUNT_I2C
3046 enable support for the bootcounter on an i2c (like RTC) device.
3047 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3048 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3050 CONFIG_BOOTCOUNT_ALEN = address len
3052 - Show boot progress:
3053 CONFIG_SHOW_BOOT_PROGRESS
3055 Defining this option allows to add some board-
3056 specific code (calling a user-provided function
3057 "show_boot_progress(int)") that enables you to show
3058 the system's boot progress on some display (for
3059 example, some LED's) on your board. At the moment,
3060 the following checkpoints are implemented:
3063 Legacy uImage format:
3066 1 common/cmd_bootm.c before attempting to boot an image
3067 -1 common/cmd_bootm.c Image header has bad magic number
3068 2 common/cmd_bootm.c Image header has correct magic number
3069 -2 common/cmd_bootm.c Image header has bad checksum
3070 3 common/cmd_bootm.c Image header has correct checksum
3071 -3 common/cmd_bootm.c Image data has bad checksum
3072 4 common/cmd_bootm.c Image data has correct checksum
3073 -4 common/cmd_bootm.c Image is for unsupported architecture
3074 5 common/cmd_bootm.c Architecture check OK
3075 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3076 6 common/cmd_bootm.c Image Type check OK
3077 -6 common/cmd_bootm.c gunzip uncompression error
3078 -7 common/cmd_bootm.c Unimplemented compression type
3079 7 common/cmd_bootm.c Uncompression OK
3080 8 common/cmd_bootm.c No uncompress/copy overwrite error
3081 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3083 9 common/image.c Start initial ramdisk verification
3084 -10 common/image.c Ramdisk header has bad magic number
3085 -11 common/image.c Ramdisk header has bad checksum
3086 10 common/image.c Ramdisk header is OK
3087 -12 common/image.c Ramdisk data has bad checksum
3088 11 common/image.c Ramdisk data has correct checksum
3089 12 common/image.c Ramdisk verification complete, start loading
3090 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3091 13 common/image.c Start multifile image verification
3092 14 common/image.c No initial ramdisk, no multifile, continue.
3094 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3096 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3097 -31 post/post.c POST test failed, detected by post_output_backlog()
3098 -32 post/post.c POST test failed, detected by post_run_single()
3100 34 common/cmd_doc.c before loading a Image from a DOC device
3101 -35 common/cmd_doc.c Bad usage of "doc" command
3102 35 common/cmd_doc.c correct usage of "doc" command
3103 -36 common/cmd_doc.c No boot device
3104 36 common/cmd_doc.c correct boot device
3105 -37 common/cmd_doc.c Unknown Chip ID on boot device
3106 37 common/cmd_doc.c correct chip ID found, device available
3107 -38 common/cmd_doc.c Read Error on boot device
3108 38 common/cmd_doc.c reading Image header from DOC device OK
3109 -39 common/cmd_doc.c Image header has bad magic number
3110 39 common/cmd_doc.c Image header has correct magic number
3111 -40 common/cmd_doc.c Error reading Image from DOC device
3112 40 common/cmd_doc.c Image header has correct magic number
3113 41 common/cmd_ide.c before loading a Image from a IDE device
3114 -42 common/cmd_ide.c Bad usage of "ide" command
3115 42 common/cmd_ide.c correct usage of "ide" command
3116 -43 common/cmd_ide.c No boot device
3117 43 common/cmd_ide.c boot device found
3118 -44 common/cmd_ide.c Device not available
3119 44 common/cmd_ide.c Device available
3120 -45 common/cmd_ide.c wrong partition selected
3121 45 common/cmd_ide.c partition selected
3122 -46 common/cmd_ide.c Unknown partition table
3123 46 common/cmd_ide.c valid partition table found
3124 -47 common/cmd_ide.c Invalid partition type
3125 47 common/cmd_ide.c correct partition type
3126 -48 common/cmd_ide.c Error reading Image Header on boot device
3127 48 common/cmd_ide.c reading Image Header from IDE device OK
3128 -49 common/cmd_ide.c Image header has bad magic number
3129 49 common/cmd_ide.c Image header has correct magic number
3130 -50 common/cmd_ide.c Image header has bad checksum
3131 50 common/cmd_ide.c Image header has correct checksum
3132 -51 common/cmd_ide.c Error reading Image from IDE device
3133 51 common/cmd_ide.c reading Image from IDE device OK
3134 52 common/cmd_nand.c before loading a Image from a NAND device
3135 -53 common/cmd_nand.c Bad usage of "nand" command
3136 53 common/cmd_nand.c correct usage of "nand" command
3137 -54 common/cmd_nand.c No boot device
3138 54 common/cmd_nand.c boot device found
3139 -55 common/cmd_nand.c Unknown Chip ID on boot device
3140 55 common/cmd_nand.c correct chip ID found, device available
3141 -56 common/cmd_nand.c Error reading Image Header on boot device
3142 56 common/cmd_nand.c reading Image Header from NAND device OK
3143 -57 common/cmd_nand.c Image header has bad magic number
3144 57 common/cmd_nand.c Image header has correct magic number
3145 -58 common/cmd_nand.c Error reading Image from NAND device
3146 58 common/cmd_nand.c reading Image from NAND device OK
3148 -60 common/env_common.c Environment has a bad CRC, using default
3150 64 net/eth.c starting with Ethernet configuration.
3151 -64 net/eth.c no Ethernet found.
3152 65 net/eth.c Ethernet found.
3154 -80 common/cmd_net.c usage wrong
3155 80 common/cmd_net.c before calling net_loop()
3156 -81 common/cmd_net.c some error in net_loop() occurred
3157 81 common/cmd_net.c net_loop() back without error
3158 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3159 82 common/cmd_net.c trying automatic boot
3160 83 common/cmd_net.c running "source" command
3161 -83 common/cmd_net.c some error in automatic boot or "source" command
3162 84 common/cmd_net.c end without errors
3167 100 common/cmd_bootm.c Kernel FIT Image has correct format
3168 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3169 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3170 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3171 102 common/cmd_bootm.c Kernel unit name specified
3172 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3173 103 common/cmd_bootm.c Found configuration node
3174 104 common/cmd_bootm.c Got kernel subimage node offset
3175 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3176 105 common/cmd_bootm.c Kernel subimage hash verification OK
3177 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3178 106 common/cmd_bootm.c Architecture check OK
3179 -106 common/cmd_bootm.c Kernel subimage has wrong type
3180 107 common/cmd_bootm.c Kernel subimage type OK
3181 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3182 108 common/cmd_bootm.c Got kernel subimage data/size
3183 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3184 -109 common/cmd_bootm.c Can't get kernel subimage type
3185 -110 common/cmd_bootm.c Can't get kernel subimage comp
3186 -111 common/cmd_bootm.c Can't get kernel subimage os
3187 -112 common/cmd_bootm.c Can't get kernel subimage load address
3188 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3190 120 common/image.c Start initial ramdisk verification
3191 -120 common/image.c Ramdisk FIT image has incorrect format
3192 121 common/image.c Ramdisk FIT image has correct format
3193 122 common/image.c No ramdisk subimage unit name, using configuration
3194 -122 common/image.c Can't get configuration for ramdisk subimage
3195 123 common/image.c Ramdisk unit name specified
3196 -124 common/image.c Can't get ramdisk subimage node offset
3197 125 common/image.c Got ramdisk subimage node offset
3198 -125 common/image.c Ramdisk subimage hash verification failed
3199 126 common/image.c Ramdisk subimage hash verification OK
3200 -126 common/image.c Ramdisk subimage for unsupported architecture
3201 127 common/image.c Architecture check OK
3202 -127 common/image.c Can't get ramdisk subimage data/size
3203 128 common/image.c Got ramdisk subimage data/size
3204 129 common/image.c Can't get ramdisk load address
3205 -129 common/image.c Got ramdisk load address
3207 -130 common/cmd_doc.c Incorrect FIT image format
3208 131 common/cmd_doc.c FIT image format OK
3210 -140 common/cmd_ide.c Incorrect FIT image format
3211 141 common/cmd_ide.c FIT image format OK
3213 -150 common/cmd_nand.c Incorrect FIT image format
3214 151 common/cmd_nand.c FIT image format OK
3216 - legacy image format:
3217 CONFIG_IMAGE_FORMAT_LEGACY
3218 enables the legacy image format support in U-Boot.
3221 enabled if CONFIG_FIT_SIGNATURE is not defined.
3223 CONFIG_DISABLE_IMAGE_LEGACY
3224 disable the legacy image format
3226 This define is introduced, as the legacy image format is
3227 enabled per default for backward compatibility.
3229 - FIT image support:
3230 CONFIG_FIT_DISABLE_SHA256
3231 Supporting SHA256 hashes has quite an impact on binary size.
3232 For constrained systems sha256 hash support can be disabled
3235 TODO(sjg@chromium.org): Adjust this option to be positive,
3236 and move it to Kconfig
3238 - Standalone program support:
3239 CONFIG_STANDALONE_LOAD_ADDR
3241 This option defines a board specific value for the
3242 address where standalone program gets loaded, thus
3243 overwriting the architecture dependent default
3246 - Frame Buffer Address:
3249 Define CONFIG_FB_ADDR if you want to use specific
3250 address for frame buffer. This is typically the case
3251 when using a graphics controller has separate video
3252 memory. U-Boot will then place the frame buffer at
3253 the given address instead of dynamically reserving it
3254 in system RAM by calling lcd_setmem(), which grabs
3255 the memory for the frame buffer depending on the
3256 configured panel size.
3258 Please see board_init_f function.
3260 - Automatic software updates via TFTP server
3262 CONFIG_UPDATE_TFTP_CNT_MAX
3263 CONFIG_UPDATE_TFTP_MSEC_MAX
3265 These options enable and control the auto-update feature;
3266 for a more detailed description refer to doc/README.update.
3268 - MTD Support (mtdparts command, UBI support)
3271 Adds the MTD device infrastructure from the Linux kernel.
3272 Needed for mtdparts command support.
3274 CONFIG_MTD_PARTITIONS
3276 Adds the MTD partitioning infrastructure from the Linux
3277 kernel. Needed for UBI support.
3282 Adds commands for interacting with MTD partitions formatted
3283 with the UBI flash translation layer
3285 Requires also defining CONFIG_RBTREE
3287 CONFIG_UBI_SILENCE_MSG
3289 Make the verbose messages from UBI stop printing. This leaves
3290 warnings and errors enabled.
3293 CONFIG_MTD_UBI_WL_THRESHOLD
3294 This parameter defines the maximum difference between the highest
3295 erase counter value and the lowest erase counter value of eraseblocks
3296 of UBI devices. When this threshold is exceeded, UBI starts performing
3297 wear leveling by means of moving data from eraseblock with low erase
3298 counter to eraseblocks with high erase counter.
3300 The default value should be OK for SLC NAND flashes, NOR flashes and
3301 other flashes which have eraseblock life-cycle 100000 or more.
3302 However, in case of MLC NAND flashes which typically have eraseblock
3303 life-cycle less than 10000, the threshold should be lessened (e.g.,
3304 to 128 or 256, although it does not have to be power of 2).
3308 CONFIG_MTD_UBI_BEB_LIMIT
3309 This option specifies the maximum bad physical eraseblocks UBI
3310 expects on the MTD device (per 1024 eraseblocks). If the
3311 underlying flash does not admit of bad eraseblocks (e.g. NOR
3312 flash), this value is ignored.
3314 NAND datasheets often specify the minimum and maximum NVM
3315 (Number of Valid Blocks) for the flashes' endurance lifetime.
3316 The maximum expected bad eraseblocks per 1024 eraseblocks
3317 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3318 which gives 20 for most NANDs (MaxNVB is basically the total
3319 count of eraseblocks on the chip).
3321 To put it differently, if this value is 20, UBI will try to
3322 reserve about 1.9% of physical eraseblocks for bad blocks
3323 handling. And that will be 1.9% of eraseblocks on the entire
3324 NAND chip, not just the MTD partition UBI attaches. This means
3325 that if you have, say, a NAND flash chip admits maximum 40 bad
3326 eraseblocks, and it is split on two MTD partitions of the same
3327 size, UBI will reserve 40 eraseblocks when attaching a
3332 CONFIG_MTD_UBI_FASTMAP
3333 Fastmap is a mechanism which allows attaching an UBI device
3334 in nearly constant time. Instead of scanning the whole MTD device it
3335 only has to locate a checkpoint (called fastmap) on the device.
3336 The on-flash fastmap contains all information needed to attach
3337 the device. Using fastmap makes only sense on large devices where
3338 attaching by scanning takes long. UBI will not automatically install
3339 a fastmap on old images, but you can set the UBI parameter
3340 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3341 that fastmap-enabled images are still usable with UBI implementations
3342 without fastmap support. On typical flash devices the whole fastmap
3343 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3345 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3346 Set this parameter to enable fastmap automatically on images
3350 CONFIG_MTD_UBI_FM_DEBUG
3351 Enable UBI fastmap debug
3357 Adds commands for interacting with UBI volumes formatted as
3358 UBIFS. UBIFS is read-only in u-boot.
3360 Requires UBI support as well as CONFIG_LZO
3362 CONFIG_UBIFS_SILENCE_MSG
3364 Make the verbose messages from UBIFS stop printing. This leaves
3365 warnings and errors enabled.
3369 Enable building of SPL globally.
3372 LDSCRIPT for linking the SPL binary.
3374 CONFIG_SPL_MAX_FOOTPRINT
3375 Maximum size in memory allocated to the SPL, BSS included.
3376 When defined, the linker checks that the actual memory
3377 used by SPL from _start to __bss_end does not exceed it.
3378 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3379 must not be both defined at the same time.
3382 Maximum size of the SPL image (text, data, rodata, and
3383 linker lists sections), BSS excluded.
3384 When defined, the linker checks that the actual size does
3387 CONFIG_SPL_TEXT_BASE
3388 TEXT_BASE for linking the SPL binary.
3390 CONFIG_SPL_RELOC_TEXT_BASE
3391 Address to relocate to. If unspecified, this is equal to
3392 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3394 CONFIG_SPL_BSS_START_ADDR
3395 Link address for the BSS within the SPL binary.
3397 CONFIG_SPL_BSS_MAX_SIZE
3398 Maximum size in memory allocated to the SPL BSS.
3399 When defined, the linker checks that the actual memory used
3400 by SPL from __bss_start to __bss_end does not exceed it.
3401 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3402 must not be both defined at the same time.
3405 Adress of the start of the stack SPL will use
3407 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3408 When defined, SPL will panic() if the image it has
3409 loaded does not have a signature.
3410 Defining this is useful when code which loads images
3411 in SPL cannot guarantee that absolutely all read errors
3413 An example is the LPC32XX MLC NAND driver, which will
3414 consider that a completely unreadable NAND block is bad,
3415 and thus should be skipped silently.
3417 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3418 When defined, SPL will proceed to another boot method
3419 if the image it has loaded does not have a signature.
3421 CONFIG_SPL_RELOC_STACK
3422 Adress of the start of the stack SPL will use after
3423 relocation. If unspecified, this is equal to
3426 CONFIG_SYS_SPL_MALLOC_START
3427 Starting address of the malloc pool used in SPL.
3428 When this option is set the full malloc is used in SPL and
3429 it is set up by spl_init() and before that, the simple malloc()
3430 can be used if CONFIG_SYS_MALLOC_F is defined.
3432 CONFIG_SYS_SPL_MALLOC_SIZE
3433 The size of the malloc pool used in SPL.
3435 CONFIG_SPL_FRAMEWORK
3436 Enable the SPL framework under common/. This framework
3437 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3438 NAND loading of the Linux Kernel.
3441 Enable booting directly to an OS from SPL.
3442 See also: doc/README.falcon
3444 CONFIG_SPL_DISPLAY_PRINT
3445 For ARM, enable an optional function to print more information
3446 about the running system.
3448 CONFIG_SPL_INIT_MINIMAL
3449 Arch init code should be built for a very small image
3451 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3452 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3453 Address and partition on the MMC to load U-Boot from
3454 when the MMC is being used in raw mode.
3456 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3457 Partition on the MMC to load U-Boot from when the MMC is being
3460 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3461 Sector to load kernel uImage from when MMC is being
3462 used in raw mode (for Falcon mode)
3464 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3465 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3466 Sector and number of sectors to load kernel argument
3467 parameters from when MMC is being used in raw mode
3470 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3471 Partition on the MMC to load U-Boot from when the MMC is being
3474 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3475 Filename to read to load U-Boot when reading from filesystem
3477 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3478 Filename to read to load kernel uImage when reading
3479 from filesystem (for Falcon mode)
3481 CONFIG_SPL_FS_LOAD_ARGS_NAME
3482 Filename to read to load kernel argument parameters
3483 when reading from filesystem (for Falcon mode)
3485 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3486 Set this for NAND SPL on PPC mpc83xx targets, so that
3487 start.S waits for the rest of the SPL to load before
3488 continuing (the hardware starts execution after just
3489 loading the first page rather than the full 4K).
3491 CONFIG_SPL_SKIP_RELOCATE
3492 Avoid SPL relocation
3494 CONFIG_SPL_NAND_BASE
3495 Include nand_base.c in the SPL. Requires
3496 CONFIG_SPL_NAND_DRIVERS.
3498 CONFIG_SPL_NAND_DRIVERS
3499 SPL uses normal NAND drivers, not minimal drivers.
3502 Include standard software ECC in the SPL
3504 CONFIG_SPL_NAND_SIMPLE
3505 Support for NAND boot using simple NAND drivers that
3506 expose the cmd_ctrl() interface.
3509 Support for a lightweight UBI (fastmap) scanner and
3512 CONFIG_SPL_NAND_RAW_ONLY
3513 Support to boot only raw u-boot.bin images. Use this only
3514 if you need to save space.
3516 CONFIG_SPL_COMMON_INIT_DDR
3517 Set for common ddr init with serial presence detect in
3520 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3521 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3522 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3523 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3524 CONFIG_SYS_NAND_ECCBYTES
3525 Defines the size and behavior of the NAND that SPL uses
3528 CONFIG_SPL_NAND_BOOT
3529 Add support NAND boot
3531 CONFIG_SYS_NAND_U_BOOT_OFFS
3532 Location in NAND to read U-Boot from
3534 CONFIG_SYS_NAND_U_BOOT_DST
3535 Location in memory to load U-Boot to
3537 CONFIG_SYS_NAND_U_BOOT_SIZE
3538 Size of image to load
3540 CONFIG_SYS_NAND_U_BOOT_START
3541 Entry point in loaded image to jump to
3543 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3544 Define this if you need to first read the OOB and then the
3545 data. This is used, for example, on davinci platforms.
3547 CONFIG_SPL_OMAP3_ID_NAND
3548 Support for an OMAP3-specific set of functions to return the
3549 ID and MFR of the first attached NAND chip, if present.
3551 CONFIG_SPL_RAM_DEVICE
3552 Support for running image already present in ram, in SPL binary
3555 Image offset to which the SPL should be padded before appending
3556 the SPL payload. By default, this is defined as
3557 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3558 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3559 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3562 Final target image containing SPL and payload. Some SPLs
3563 use an arch-specific makefile fragment instead, for
3564 example if more than one image needs to be produced.
3566 CONFIG_FIT_SPL_PRINT
3567 Printing information about a FIT image adds quite a bit of
3568 code to SPL. So this is normally disabled in SPL. Use this
3569 option to re-enable it. This will affect the output of the
3570 bootm command when booting a FIT image.
3574 Enable building of TPL globally.
3577 Image offset to which the TPL should be padded before appending
3578 the TPL payload. By default, this is defined as
3579 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3580 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3581 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3583 - Interrupt support (PPC):
3585 There are common interrupt_init() and timer_interrupt()
3586 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3587 for CPU specific initialization. interrupt_init_cpu()
3588 should set decrementer_count to appropriate value. If
3589 CPU resets decrementer automatically after interrupt
3590 (ppc4xx) it should set decrementer_count to zero.
3591 timer_interrupt() calls timer_interrupt_cpu() for CPU
3592 specific handling. If board has watchdog / status_led
3593 / other_activity_monitor it works automatically from
3594 general timer_interrupt().
3597 Board initialization settings:
3598 ------------------------------
3600 During Initialization u-boot calls a number of board specific functions
3601 to allow the preparation of board specific prerequisites, e.g. pin setup
3602 before drivers are initialized. To enable these callbacks the
3603 following configuration macros have to be defined. Currently this is
3604 architecture specific, so please check arch/your_architecture/lib/board.c
3605 typically in board_init_f() and board_init_r().
3607 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3608 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3609 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3610 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3612 Configuration Settings:
3613 -----------------------
3615 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3616 Optionally it can be defined to support 64-bit memory commands.
3618 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3619 undefine this when you're short of memory.
3621 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3622 width of the commands listed in the 'help' command output.
3624 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3625 prompt for user input.
3627 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3629 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3631 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3633 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3634 the application (usually a Linux kernel) when it is
3637 - CONFIG_SYS_BAUDRATE_TABLE:
3638 List of legal baudrate settings for this board.
3640 - CONFIG_SYS_CONSOLE_INFO_QUIET
3641 Suppress display of console information at boot.
3643 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3644 If the board specific function
3645 extern int overwrite_console (void);
3646 returns 1, the stdin, stderr and stdout are switched to the
3647 serial port, else the settings in the environment are used.
3649 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3650 Enable the call to overwrite_console().
3652 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3653 Enable overwrite of previous console environment settings.
3655 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3656 Begin and End addresses of the area used by the
3659 - CONFIG_SYS_ALT_MEMTEST:
3660 Enable an alternate, more extensive memory test.
3662 - CONFIG_SYS_MEMTEST_SCRATCH:
3663 Scratch address used by the alternate memory test
3664 You only need to set this if address zero isn't writeable
3666 - CONFIG_SYS_MEM_RESERVE_SECURE
3667 Only implemented for ARMv8 for now.
3668 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3669 is substracted from total RAM and won't be reported to OS.
3670 This memory can be used as secure memory. A variable
3671 gd->arch.secure_ram is used to track the location. In systems
3672 the RAM base is not zero, or RAM is divided into banks,
3673 this variable needs to be recalcuated to get the address.
3675 - CONFIG_SYS_MEM_TOP_HIDE:
3676 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3677 this specified memory area will get subtracted from the top
3678 (end) of RAM and won't get "touched" at all by U-Boot. By
3679 fixing up gd->ram_size the Linux kernel should gets passed
3680 the now "corrected" memory size and won't touch it either.
3681 This should work for arch/ppc and arch/powerpc. Only Linux
3682 board ports in arch/powerpc with bootwrapper support that
3683 recalculate the memory size from the SDRAM controller setup
3684 will have to get fixed in Linux additionally.
3686 This option can be used as a workaround for the 440EPx/GRx
3687 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3690 WARNING: Please make sure that this value is a multiple of
3691 the Linux page size (normally 4k). If this is not the case,
3692 then the end address of the Linux memory will be located at a
3693 non page size aligned address and this could cause major
3696 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3697 Enable temporary baudrate change while serial download
3699 - CONFIG_SYS_SDRAM_BASE:
3700 Physical start address of SDRAM. _Must_ be 0 here.
3702 - CONFIG_SYS_FLASH_BASE:
3703 Physical start address of Flash memory.
3705 - CONFIG_SYS_MONITOR_BASE:
3706 Physical start address of boot monitor code (set by
3707 make config files to be same as the text base address
3708 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3709 CONFIG_SYS_FLASH_BASE when booting from flash.
3711 - CONFIG_SYS_MONITOR_LEN:
3712 Size of memory reserved for monitor code, used to
3713 determine _at_compile_time_ (!) if the environment is
3714 embedded within the U-Boot image, or in a separate
3717 - CONFIG_SYS_MALLOC_LEN:
3718 Size of DRAM reserved for malloc() use.
3720 - CONFIG_SYS_MALLOC_F_LEN
3721 Size of the malloc() pool for use before relocation. If
3722 this is defined, then a very simple malloc() implementation
3723 will become available before relocation. The address is just
3724 below the global data, and the stack is moved down to make
3727 This feature allocates regions with increasing addresses
3728 within the region. calloc() is supported, but realloc()
3729 is not available. free() is supported but does nothing.
3730 The memory will be freed (or in fact just forgotten) when
3731 U-Boot relocates itself.
3733 - CONFIG_SYS_MALLOC_SIMPLE
3734 Provides a simple and small malloc() and calloc() for those
3735 boards which do not use the full malloc in SPL (which is
3736 enabled with CONFIG_SYS_SPL_MALLOC_START).
3738 - CONFIG_SYS_NONCACHED_MEMORY:
3739 Size of non-cached memory area. This area of memory will be
3740 typically located right below the malloc() area and mapped
3741 uncached in the MMU. This is useful for drivers that would
3742 otherwise require a lot of explicit cache maintenance. For
3743 some drivers it's also impossible to properly maintain the
3744 cache. For example if the regions that need to be flushed
3745 are not a multiple of the cache-line size, *and* padding
3746 cannot be allocated between the regions to align them (i.e.
3747 if the HW requires a contiguous array of regions, and the
3748 size of each region is not cache-aligned), then a flush of
3749 one region may result in overwriting data that hardware has
3750 written to another region in the same cache-line. This can
3751 happen for example in network drivers where descriptors for
3752 buffers are typically smaller than the CPU cache-line (e.g.
3753 16 bytes vs. 32 or 64 bytes).
3755 Non-cached memory is only supported on 32-bit ARM at present.
3757 - CONFIG_SYS_BOOTM_LEN:
3758 Normally compressed uImages are limited to an
3759 uncompressed size of 8 MBytes. If this is not enough,
3760 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3761 to adjust this setting to your needs.
3763 - CONFIG_SYS_BOOTMAPSZ:
3764 Maximum size of memory mapped by the startup code of
3765 the Linux kernel; all data that must be processed by
3766 the Linux kernel (bd_info, boot arguments, FDT blob if
3767 used) must be put below this limit, unless "bootm_low"
3768 environment variable is defined and non-zero. In such case
3769 all data for the Linux kernel must be between "bootm_low"
3770 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3771 variable "bootm_mapsize" will override the value of
3772 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3773 then the value in "bootm_size" will be used instead.
3775 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3776 Enable initrd_high functionality. If defined then the
3777 initrd_high feature is enabled and the bootm ramdisk subcommand
3780 - CONFIG_SYS_BOOT_GET_CMDLINE:
3781 Enables allocating and saving kernel cmdline in space between
3782 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3784 - CONFIG_SYS_BOOT_GET_KBD:
3785 Enables allocating and saving a kernel copy of the bd_info in
3786 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3788 - CONFIG_SYS_MAX_FLASH_BANKS:
3789 Max number of Flash memory banks
3791 - CONFIG_SYS_MAX_FLASH_SECT:
3792 Max number of sectors on a Flash chip
3794 - CONFIG_SYS_FLASH_ERASE_TOUT:
3795 Timeout for Flash erase operations (in ms)
3797 - CONFIG_SYS_FLASH_WRITE_TOUT:
3798 Timeout for Flash write operations (in ms)
3800 - CONFIG_SYS_FLASH_LOCK_TOUT
3801 Timeout for Flash set sector lock bit operation (in ms)
3803 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3804 Timeout for Flash clear lock bits operation (in ms)
3806 - CONFIG_SYS_FLASH_PROTECTION
3807 If defined, hardware flash sectors protection is used
3808 instead of U-Boot software protection.
3810 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3812 Enable TFTP transfers directly to flash memory;
3813 without this option such a download has to be
3814 performed in two steps: (1) download to RAM, and (2)
3815 copy from RAM to flash.
3817 The two-step approach is usually more reliable, since
3818 you can check if the download worked before you erase
3819 the flash, but in some situations (when system RAM is
3820 too limited to allow for a temporary copy of the
3821 downloaded image) this option may be very useful.
3823 - CONFIG_SYS_FLASH_CFI:
3824 Define if the flash driver uses extra elements in the
3825 common flash structure for storing flash geometry.
3827 - CONFIG_FLASH_CFI_DRIVER
3828 This option also enables the building of the cfi_flash driver
3829 in the drivers directory
3831 - CONFIG_FLASH_CFI_MTD
3832 This option enables the building of the cfi_mtd driver
3833 in the drivers directory. The driver exports CFI flash
3836 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3837 Use buffered writes to flash.
3839 - CONFIG_FLASH_SPANSION_S29WS_N
3840 s29ws-n MirrorBit flash has non-standard addresses for buffered
3843 - CONFIG_SYS_FLASH_QUIET_TEST
3844 If this option is defined, the common CFI flash doesn't
3845 print it's warning upon not recognized FLASH banks. This
3846 is useful, if some of the configured banks are only
3847 optionally available.
3849 - CONFIG_FLASH_SHOW_PROGRESS
3850 If defined (must be an integer), print out countdown
3851 digits and dots. Recommended value: 45 (9..1) for 80
3852 column displays, 15 (3..1) for 40 column displays.
3854 - CONFIG_FLASH_VERIFY
3855 If defined, the content of the flash (destination) is compared
3856 against the source after the write operation. An error message
3857 will be printed when the contents are not identical.
3858 Please note that this option is useless in nearly all cases,
3859 since such flash programming errors usually are detected earlier
3860 while unprotecting/erasing/programming. Please only enable
3861 this option if you really know what you are doing.
3863 - CONFIG_SYS_RX_ETH_BUFFER:
3864 Defines the number of Ethernet receive buffers. On some
3865 Ethernet controllers it is recommended to set this value
3866 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3867 buffers can be full shortly after enabling the interface
3868 on high Ethernet traffic.
3869 Defaults to 4 if not defined.
3871 - CONFIG_ENV_MAX_ENTRIES
3873 Maximum number of entries in the hash table that is used
3874 internally to store the environment settings. The default
3875 setting is supposed to be generous and should work in most
3876 cases. This setting can be used to tune behaviour; see
3877 lib/hashtable.c for details.
3879 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3880 - CONFIG_ENV_FLAGS_LIST_STATIC
3881 Enable validation of the values given to environment variables when
3882 calling env set. Variables can be restricted to only decimal,
3883 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3884 the variables can also be restricted to IP address or MAC address.
3886 The format of the list is:
3887 type_attribute = [s|d|x|b|i|m]
3888 access_attribute = [a|r|o|c]
3889 attributes = type_attribute[access_attribute]
3890 entry = variable_name[:attributes]
3893 The type attributes are:
3894 s - String (default)
3897 b - Boolean ([1yYtT|0nNfF])
3901 The access attributes are:
3907 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3908 Define this to a list (string) to define the ".flags"
3909 environment variable in the default or embedded environment.
3911 - CONFIG_ENV_FLAGS_LIST_STATIC
3912 Define this to a list (string) to define validation that
3913 should be done if an entry is not found in the ".flags"
3914 environment variable. To override a setting in the static
3915 list, simply add an entry for the same variable name to the
3918 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3919 regular expression. This allows multiple variables to define the same
3920 flags without explicitly listing them for each variable.
3922 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3923 If defined, don't allow the -f switch to env set override variable
3926 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3927 This is set by OMAP boards for the max time that reset should
3928 be asserted. See doc/README.omap-reset-time for details on how
3929 the value can be calculated on a given board.
3932 If stdint.h is available with your toolchain you can define this
3933 option to enable it. You can provide option 'USE_STDINT=1' when
3934 building U-Boot to enable this.
3936 The following definitions that deal with the placement and management
3937 of environment data (variable area); in general, we support the
3938 following configurations:
3940 - CONFIG_BUILD_ENVCRC:
3942 Builds up envcrc with the target environment so that external utils
3943 may easily extract it and embed it in final U-Boot images.
3945 - CONFIG_ENV_IS_IN_FLASH:
3947 Define this if the environment is in flash memory.
3949 a) The environment occupies one whole flash sector, which is
3950 "embedded" in the text segment with the U-Boot code. This
3951 happens usually with "bottom boot sector" or "top boot
3952 sector" type flash chips, which have several smaller
3953 sectors at the start or the end. For instance, such a
3954 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3955 such a case you would place the environment in one of the
3956 4 kB sectors - with U-Boot code before and after it. With
3957 "top boot sector" type flash chips, you would put the
3958 environment in one of the last sectors, leaving a gap
3959 between U-Boot and the environment.
3961 - CONFIG_ENV_OFFSET:
3963 Offset of environment data (variable area) to the
3964 beginning of flash memory; for instance, with bottom boot
3965 type flash chips the second sector can be used: the offset
3966 for this sector is given here.
3968 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3972 This is just another way to specify the start address of
3973 the flash sector containing the environment (instead of
3976 - CONFIG_ENV_SECT_SIZE:
3978 Size of the sector containing the environment.
3981 b) Sometimes flash chips have few, equal sized, BIG sectors.
3982 In such a case you don't want to spend a whole sector for
3987 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3988 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3989 of this flash sector for the environment. This saves
3990 memory for the RAM copy of the environment.
3992 It may also save flash memory if you decide to use this
3993 when your environment is "embedded" within U-Boot code,
3994 since then the remainder of the flash sector could be used
3995 for U-Boot code. It should be pointed out that this is
3996 STRONGLY DISCOURAGED from a robustness point of view:
3997 updating the environment in flash makes it always
3998 necessary to erase the WHOLE sector. If something goes
3999 wrong before the contents has been restored from a copy in
4000 RAM, your target system will be dead.
4002 - CONFIG_ENV_ADDR_REDUND
4003 CONFIG_ENV_SIZE_REDUND
4005 These settings describe a second storage area used to hold
4006 a redundant copy of the environment data, so that there is
4007 a valid backup copy in case there is a power failure during
4008 a "saveenv" operation.
4010 BE CAREFUL! Any changes to the flash layout, and some changes to the
4011 source code will make it necessary to adapt <board>/u-boot.lds*
4015 - CONFIG_ENV_IS_IN_NVRAM:
4017 Define this if you have some non-volatile memory device
4018 (NVRAM, battery buffered SRAM) which you want to use for the
4024 These two #defines are used to determine the memory area you
4025 want to use for environment. It is assumed that this memory
4026 can just be read and written to, without any special
4029 BE CAREFUL! The first access to the environment happens quite early
4030 in U-Boot initialization (when we try to get the setting of for the
4031 console baudrate). You *MUST* have mapped your NVRAM area then, or
4034 Please note that even with NVRAM we still use a copy of the
4035 environment in RAM: we could work on NVRAM directly, but we want to
4036 keep settings there always unmodified except somebody uses "saveenv"
4037 to save the current settings.
4040 - CONFIG_ENV_IS_IN_EEPROM:
4042 Use this if you have an EEPROM or similar serial access
4043 device and a driver for it.
4045 - CONFIG_ENV_OFFSET:
4048 These two #defines specify the offset and size of the
4049 environment area within the total memory of your EEPROM.
4051 - CONFIG_SYS_I2C_EEPROM_ADDR:
4052 If defined, specified the chip address of the EEPROM device.
4053 The default address is zero.
4055 - CONFIG_SYS_I2C_EEPROM_BUS:
4056 If defined, specified the i2c bus of the EEPROM device.
4058 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4059 If defined, the number of bits used to address bytes in a
4060 single page in the EEPROM device. A 64 byte page, for example
4061 would require six bits.
4063 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4064 If defined, the number of milliseconds to delay between
4065 page writes. The default is zero milliseconds.
4067 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4068 The length in bytes of the EEPROM memory array address. Note
4069 that this is NOT the chip address length!
4071 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4072 EEPROM chips that implement "address overflow" are ones
4073 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4074 address and the extra bits end up in the "chip address" bit
4075 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4078 Note that we consider the length of the address field to
4079 still be one byte because the extra address bits are hidden
4080 in the chip address.
4082 - CONFIG_SYS_EEPROM_SIZE:
4083 The size in bytes of the EEPROM device.
4085 - CONFIG_ENV_EEPROM_IS_ON_I2C
4086 define this, if you have I2C and SPI activated, and your
4087 EEPROM, which holds the environment, is on the I2C bus.
4089 - CONFIG_I2C_ENV_EEPROM_BUS
4090 if you have an Environment on an EEPROM reached over
4091 I2C muxes, you can define here, how to reach this
4092 EEPROM. For example:
4094 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4096 EEPROM which holds the environment, is reached over
4097 a pca9547 i2c mux with address 0x70, channel 3.
4099 - CONFIG_ENV_IS_IN_DATAFLASH:
4101 Define this if you have a DataFlash memory device which you
4102 want to use for the environment.
4104 - CONFIG_ENV_OFFSET:
4108 These three #defines specify the offset and size of the
4109 environment area within the total memory of your DataFlash placed
4110 at the specified address.
4112 - CONFIG_ENV_IS_IN_SPI_FLASH:
4114 Define this if you have a SPI Flash memory device which you
4115 want to use for the environment.
4117 - CONFIG_ENV_OFFSET:
4120 These two #defines specify the offset and size of the
4121 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4122 aligned to an erase sector boundary.
4124 - CONFIG_ENV_SECT_SIZE:
4126 Define the SPI flash's sector size.
4128 - CONFIG_ENV_OFFSET_REDUND (optional):
4130 This setting describes a second storage area of CONFIG_ENV_SIZE
4131 size used to hold a redundant copy of the environment data, so
4132 that there is a valid backup copy in case there is a power failure
4133 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4134 aligned to an erase sector boundary.
4136 - CONFIG_ENV_SPI_BUS (optional):
4137 - CONFIG_ENV_SPI_CS (optional):
4139 Define the SPI bus and chip select. If not defined they will be 0.
4141 - CONFIG_ENV_SPI_MAX_HZ (optional):
4143 Define the SPI max work clock. If not defined then use 1MHz.
4145 - CONFIG_ENV_SPI_MODE (optional):
4147 Define the SPI work mode. If not defined then use SPI_MODE_3.
4149 - CONFIG_ENV_IS_IN_REMOTE:
4151 Define this if you have a remote memory space which you
4152 want to use for the local device's environment.
4157 These two #defines specify the address and size of the
4158 environment area within the remote memory space. The
4159 local device can get the environment from remote memory
4160 space by SRIO or PCIE links.
4162 BE CAREFUL! For some special cases, the local device can not use
4163 "saveenv" command. For example, the local device will get the
4164 environment stored in a remote NOR flash by SRIO or PCIE link,
4165 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4167 - CONFIG_ENV_IS_IN_NAND:
4169 Define this if you have a NAND device which you want to use
4170 for the environment.
4172 - CONFIG_ENV_OFFSET:
4175 These two #defines specify the offset and size of the environment
4176 area within the first NAND device. CONFIG_ENV_OFFSET must be
4177 aligned to an erase block boundary.
4179 - CONFIG_ENV_OFFSET_REDUND (optional):
4181 This setting describes a second storage area of CONFIG_ENV_SIZE
4182 size used to hold a redundant copy of the environment data, so
4183 that there is a valid backup copy in case there is a power failure
4184 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4185 aligned to an erase block boundary.
4187 - CONFIG_ENV_RANGE (optional):
4189 Specifies the length of the region in which the environment
4190 can be written. This should be a multiple of the NAND device's
4191 block size. Specifying a range with more erase blocks than
4192 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4193 the range to be avoided.
4195 - CONFIG_ENV_OFFSET_OOB (optional):
4197 Enables support for dynamically retrieving the offset of the
4198 environment from block zero's out-of-band data. The
4199 "nand env.oob" command can be used to record this offset.
4200 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4201 using CONFIG_ENV_OFFSET_OOB.
4203 - CONFIG_NAND_ENV_DST
4205 Defines address in RAM to which the nand_spl code should copy the
4206 environment. If redundant environment is used, it will be copied to
4207 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4209 - CONFIG_ENV_IS_IN_UBI:
4211 Define this if you have an UBI volume that you want to use for the
4212 environment. This has the benefit of wear-leveling the environment
4213 accesses, which is important on NAND.
4215 - CONFIG_ENV_UBI_PART:
4217 Define this to a string that is the mtd partition containing the UBI.
4219 - CONFIG_ENV_UBI_VOLUME:
4221 Define this to the name of the volume that you want to store the
4224 - CONFIG_ENV_UBI_VOLUME_REDUND:
4226 Define this to the name of another volume to store a second copy of
4227 the environment in. This will enable redundant environments in UBI.
4228 It is assumed that both volumes are in the same MTD partition.
4230 - CONFIG_UBI_SILENCE_MSG
4231 - CONFIG_UBIFS_SILENCE_MSG
4233 You will probably want to define these to avoid a really noisy system
4234 when storing the env in UBI.
4236 - CONFIG_ENV_IS_IN_FAT:
4237 Define this if you want to use the FAT file system for the environment.
4239 - FAT_ENV_INTERFACE:
4241 Define this to a string that is the name of the block device.
4243 - FAT_ENV_DEV_AND_PART:
4245 Define this to a string to specify the partition of the device. It can
4248 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4249 - "D:P": device D partition P. Error occurs if device D has no
4252 - "D" or "D:": device D partition 1 if device D has partition
4253 table, or the whole device D if has no partition
4255 - "D:auto": first partition in device D with bootable flag set.
4256 If none, first valid partition in device D. If no
4257 partition table then means device D.
4261 It's a string of the FAT file name. This file use to store the
4265 This should be defined. Otherwise it cannot save the environment file.
4267 - CONFIG_ENV_IS_IN_MMC:
4269 Define this if you have an MMC device which you want to use for the
4272 - CONFIG_SYS_MMC_ENV_DEV:
4274 Specifies which MMC device the environment is stored in.
4276 - CONFIG_SYS_MMC_ENV_PART (optional):
4278 Specifies which MMC partition the environment is stored in. If not
4279 set, defaults to partition 0, the user area. Common values might be
4280 1 (first MMC boot partition), 2 (second MMC boot partition).
4282 - CONFIG_ENV_OFFSET:
4285 These two #defines specify the offset and size of the environment
4286 area within the specified MMC device.
4288 If offset is positive (the usual case), it is treated as relative to
4289 the start of the MMC partition. If offset is negative, it is treated
4290 as relative to the end of the MMC partition. This can be useful if
4291 your board may be fitted with different MMC devices, which have
4292 different sizes for the MMC partitions, and you always want the
4293 environment placed at the very end of the partition, to leave the
4294 maximum possible space before it, to store other data.
4296 These two values are in units of bytes, but must be aligned to an
4297 MMC sector boundary.
4299 - CONFIG_ENV_OFFSET_REDUND (optional):
4301 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4302 hold a redundant copy of the environment data. This provides a
4303 valid backup copy in case the other copy is corrupted, e.g. due
4304 to a power failure during a "saveenv" operation.
4306 This value may also be positive or negative; this is handled in the
4307 same way as CONFIG_ENV_OFFSET.
4309 This value is also in units of bytes, but must also be aligned to
4310 an MMC sector boundary.
4312 - CONFIG_ENV_SIZE_REDUND (optional):
4314 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4315 set. If this value is set, it must be set to the same value as
4318 - CONFIG_SYS_SPI_INIT_OFFSET
4320 Defines offset to the initial SPI buffer area in DPRAM. The
4321 area is used at an early stage (ROM part) if the environment
4322 is configured to reside in the SPI EEPROM: We need a 520 byte
4323 scratch DPRAM area. It is used between the two initialization
4324 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4325 to be a good choice since it makes it far enough from the
4326 start of the data area as well as from the stack pointer.
4328 Please note that the environment is read-only until the monitor
4329 has been relocated to RAM and a RAM copy of the environment has been
4330 created; also, when using EEPROM you will have to use getenv_f()
4331 until then to read environment variables.
4333 The environment is protected by a CRC32 checksum. Before the monitor
4334 is relocated into RAM, as a result of a bad CRC you will be working
4335 with the compiled-in default environment - *silently*!!! [This is
4336 necessary, because the first environment variable we need is the
4337 "baudrate" setting for the console - if we have a bad CRC, we don't
4338 have any device yet where we could complain.]
4340 Note: once the monitor has been relocated, then it will complain if
4341 the default environment is used; a new CRC is computed as soon as you
4342 use the "saveenv" command to store a valid environment.
4344 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4345 Echo the inverted Ethernet link state to the fault LED.
4347 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4348 also needs to be defined.
4350 - CONFIG_SYS_FAULT_MII_ADDR:
4351 MII address of the PHY to check for the Ethernet link state.
4353 - CONFIG_NS16550_MIN_FUNCTIONS:
4354 Define this if you desire to only have use of the NS16550_init
4355 and NS16550_putc functions for the serial driver located at
4356 drivers/serial/ns16550.c. This option is useful for saving
4357 space for already greatly restricted images, including but not
4358 limited to NAND_SPL configurations.
4360 - CONFIG_DISPLAY_BOARDINFO
4361 Display information about the board that U-Boot is running on
4362 when U-Boot starts up. The board function checkboard() is called
4365 - CONFIG_DISPLAY_BOARDINFO_LATE
4366 Similar to the previous option, but display this information
4367 later, once stdio is running and output goes to the LCD, if
4370 - CONFIG_BOARD_SIZE_LIMIT:
4371 Maximum size of the U-Boot image. When defined, the
4372 build system checks that the actual size does not
4375 Low Level (hardware related) configuration options:
4376 ---------------------------------------------------
4378 - CONFIG_SYS_CACHELINE_SIZE:
4379 Cache Line Size of the CPU.
4381 - CONFIG_SYS_DEFAULT_IMMR:
4382 Default address of the IMMR after system reset.
4384 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4385 and RPXsuper) to be able to adjust the position of
4386 the IMMR register after a reset.
4388 - CONFIG_SYS_CCSRBAR_DEFAULT:
4389 Default (power-on reset) physical address of CCSR on Freescale
4392 - CONFIG_SYS_CCSRBAR:
4393 Virtual address of CCSR. On a 32-bit build, this is typically
4394 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4396 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4397 for cross-platform code that uses that macro instead.
4399 - CONFIG_SYS_CCSRBAR_PHYS:
4400 Physical address of CCSR. CCSR can be relocated to a new
4401 physical address, if desired. In this case, this macro should
4402 be set to that address. Otherwise, it should be set to the
4403 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4404 is typically relocated on 36-bit builds. It is recommended
4405 that this macro be defined via the _HIGH and _LOW macros:
4407 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4408 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4410 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4411 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4412 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4413 used in assembly code, so it must not contain typecasts or
4414 integer size suffixes (e.g. "ULL").
4416 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4417 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4418 used in assembly code, so it must not contain typecasts or
4419 integer size suffixes (e.g. "ULL").
4421 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4422 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4423 forced to a value that ensures that CCSR is not relocated.
4425 - Floppy Disk Support:
4426 CONFIG_SYS_FDC_DRIVE_NUMBER
4428 the default drive number (default value 0)
4430 CONFIG_SYS_ISA_IO_STRIDE
4432 defines the spacing between FDC chipset registers
4435 CONFIG_SYS_ISA_IO_OFFSET
4437 defines the offset of register from address. It
4438 depends on which part of the data bus is connected to
4439 the FDC chipset. (default value 0)
4441 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4442 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4445 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4446 fdc_hw_init() is called at the beginning of the FDC
4447 setup. fdc_hw_init() must be provided by the board
4448 source code. It is used to make hardware-dependent
4452 Most IDE controllers were designed to be connected with PCI
4453 interface. Only few of them were designed for AHB interface.
4454 When software is doing ATA command and data transfer to
4455 IDE devices through IDE-AHB controller, some additional
4456 registers accessing to these kind of IDE-AHB controller
4459 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4460 DO NOT CHANGE unless you know exactly what you're
4461 doing! (11-4) [MPC8xx/82xx systems only]
4463 - CONFIG_SYS_INIT_RAM_ADDR:
4465 Start address of memory area that can be used for
4466 initial data and stack; please note that this must be
4467 writable memory that is working WITHOUT special
4468 initialization, i. e. you CANNOT use normal RAM which
4469 will become available only after programming the
4470 memory controller and running certain initialization
4473 U-Boot uses the following memory types:
4474 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4475 - MPC824X: data cache
4476 - PPC4xx: data cache
4478 - CONFIG_SYS_GBL_DATA_OFFSET:
4480 Offset of the initial data structure in the memory
4481 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4482 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4483 data is located at the end of the available space
4484 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4485 GENERATED_GBL_DATA_SIZE), and the initial stack is just
4486 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4487 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4490 On the MPC824X (or other systems that use the data
4491 cache for initial memory) the address chosen for
4492 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4493 point to an otherwise UNUSED address space between
4494 the top of RAM and the start of the PCI space.
4496 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4498 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4500 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4502 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4504 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4506 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4508 - CONFIG_SYS_OR_TIMING_SDRAM:
4511 - CONFIG_SYS_MAMR_PTA:
4512 periodic timer for refresh
4514 - CONFIG_SYS_DER: Debug Event Register (37-47)
4516 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4517 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4518 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4519 CONFIG_SYS_BR1_PRELIM:
4520 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4522 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4523 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4524 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4525 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4527 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4528 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4529 Machine Mode Register and Memory Periodic Timer
4530 Prescaler definitions (SDRAM timing)
4532 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4533 enable I2C microcode relocation patch (MPC8xx);
4534 define relocation offset in DPRAM [DSP2]
4536 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4537 enable SMC microcode relocation patch (MPC8xx);
4538 define relocation offset in DPRAM [SMC1]
4540 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4541 enable SPI microcode relocation patch (MPC8xx);
4542 define relocation offset in DPRAM [SCC4]
4544 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4545 Offset of the bootmode word in DPRAM used by post
4546 (Power On Self Tests). This definition overrides
4547 #define'd default value in commproc.h resp.
4550 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4551 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4552 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4553 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4554 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4555 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4556 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4557 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4558 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4560 - CONFIG_PCI_DISABLE_PCIE:
4561 Disable PCI-Express on systems where it is supported but not
4564 - CONFIG_PCI_ENUM_ONLY
4565 Only scan through and get the devices on the buses.
4566 Don't do any setup work, presumably because someone or
4567 something has already done it, and we don't need to do it
4568 a second time. Useful for platforms that are pre-booted
4569 by coreboot or similar.
4571 - CONFIG_PCI_INDIRECT_BRIDGE:
4572 Enable support for indirect PCI bridges.
4575 Chip has SRIO or not
4578 Board has SRIO 1 port available
4581 Board has SRIO 2 port available
4583 - CONFIG_SRIO_PCIE_BOOT_MASTER
4584 Board can support master function for Boot from SRIO and PCIE
4586 - CONFIG_SYS_SRIOn_MEM_VIRT:
4587 Virtual Address of SRIO port 'n' memory region
4589 - CONFIG_SYS_SRIOn_MEM_PHYS:
4590 Physical Address of SRIO port 'n' memory region
4592 - CONFIG_SYS_SRIOn_MEM_SIZE:
4593 Size of SRIO port 'n' memory region
4595 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4596 Defined to tell the NAND controller that the NAND chip is using
4598 Not all NAND drivers use this symbol.
4599 Example of drivers that use it:
4600 - drivers/mtd/nand/ndfc.c
4601 - drivers/mtd/nand/mxc_nand.c
4603 - CONFIG_SYS_NDFC_EBC0_CFG
4604 Sets the EBC0_CFG register for the NDFC. If not defined
4605 a default value will be used.
4608 Get DDR timing information from an I2C EEPROM. Common
4609 with pluggable memory modules such as SODIMMs
4612 I2C address of the SPD EEPROM
4614 - CONFIG_SYS_SPD_BUS_NUM
4615 If SPD EEPROM is on an I2C bus other than the first
4616 one, specify here. Note that the value must resolve
4617 to something your driver can deal with.
4619 - CONFIG_SYS_DDR_RAW_TIMING
4620 Get DDR timing information from other than SPD. Common with
4621 soldered DDR chips onboard without SPD. DDR raw timing
4622 parameters are extracted from datasheet and hard-coded into
4623 header files or board specific files.
4625 - CONFIG_FSL_DDR_INTERACTIVE
4626 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4628 - CONFIG_FSL_DDR_SYNC_REFRESH
4629 Enable sync of refresh for multiple controllers.
4631 - CONFIG_FSL_DDR_BIST
4632 Enable built-in memory test for Freescale DDR controllers.
4634 - CONFIG_SYS_83XX_DDR_USES_CS0
4635 Only for 83xx systems. If specified, then DDR should
4636 be configured using CS0 and CS1 instead of CS2 and CS3.
4638 - CONFIG_ETHER_ON_FEC[12]
4639 Define to enable FEC[12] on a 8xx series processor.
4641 - CONFIG_FEC[12]_PHY
4642 Define to the hardcoded PHY address which corresponds
4643 to the given FEC; i. e.
4644 #define CONFIG_FEC1_PHY 4
4645 means that the PHY with address 4 is connected to FEC1
4647 When set to -1, means to probe for first available.
4649 - CONFIG_FEC[12]_PHY_NORXERR
4650 The PHY does not have a RXERR line (RMII only).
4651 (so program the FEC to ignore it).
4654 Enable RMII mode for all FECs.
4655 Note that this is a global option, we can't
4656 have one FEC in standard MII mode and another in RMII mode.
4658 - CONFIG_CRC32_VERIFY
4659 Add a verify option to the crc32 command.
4662 => crc32 -v <address> <count> <crc32>
4664 Where address/count indicate a memory area
4665 and crc32 is the correct crc32 which the
4669 Add the "loopw" memory command. This only takes effect if
4670 the memory commands are activated globally (CONFIG_CMD_MEM).
4673 Add the "mdc" and "mwc" memory commands. These are cyclic
4678 This command will print 4 bytes (10,11,12,13) each 500 ms.
4680 => mwc.l 100 12345678 10
4681 This command will write 12345678 to address 100 all 10 ms.
4683 This only takes effect if the memory commands are activated
4684 globally (CONFIG_CMD_MEM).
4686 - CONFIG_SKIP_LOWLEVEL_INIT
4687 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4688 low level initializations (like setting up the memory
4689 controller) are omitted and/or U-Boot does not
4690 relocate itself into RAM.
4692 Normally this variable MUST NOT be defined. The only
4693 exception is when U-Boot is loaded (to RAM) by some
4694 other boot loader or by a debugger which performs
4695 these initializations itself.
4697 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4698 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4699 to be skipped. The normal CP15 init (such as enabling the
4700 instruction cache) is still performed.
4703 Modifies the behaviour of start.S when compiling a loader
4704 that is executed before the actual U-Boot. E.g. when
4705 compiling a NAND SPL.
4708 Modifies the behaviour of start.S when compiling a loader
4709 that is executed after the SPL and before the actual U-Boot.
4710 It is loaded by the SPL.
4712 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4713 Only for 85xx systems. If this variable is specified, the section
4714 .resetvec is not kept and the section .bootpg is placed in the
4715 previous 4k of the .text section.
4717 - CONFIG_ARCH_MAP_SYSMEM
4718 Generally U-Boot (and in particular the md command) uses
4719 effective address. It is therefore not necessary to regard
4720 U-Boot address as virtual addresses that need to be translated
4721 to physical addresses. However, sandbox requires this, since
4722 it maintains its own little RAM buffer which contains all
4723 addressable memory. This option causes some memory accesses
4724 to be mapped through map_sysmem() / unmap_sysmem().
4726 - CONFIG_USE_ARCH_MEMCPY
4727 CONFIG_USE_ARCH_MEMSET
4728 If these options are used a optimized version of memcpy/memset will
4729 be used if available. These functions may be faster under some
4730 conditions but may increase the binary size.
4732 - CONFIG_X86_RESET_VECTOR
4733 If defined, the x86 reset vector code is included. This is not
4734 needed when U-Boot is running from Coreboot.
4737 Defines the MPU clock speed (in MHz).
4739 NOTE : currently only supported on AM335x platforms.
4741 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4742 Enables the RTC32K OSC on AM33xx based plattforms
4744 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4745 Option to disable subpage write in NAND driver
4746 driver that uses this:
4747 drivers/mtd/nand/davinci_nand.c
4749 Freescale QE/FMAN Firmware Support:
4750 -----------------------------------
4752 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4753 loading of "firmware", which is encoded in the QE firmware binary format.
4754 This firmware often needs to be loaded during U-Boot booting, so macros
4755 are used to identify the storage device (NOR flash, SPI, etc) and the address
4758 - CONFIG_SYS_FMAN_FW_ADDR
4759 The address in the storage device where the FMAN microcode is located. The
4760 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4763 - CONFIG_SYS_QE_FW_ADDR
4764 The address in the storage device where the QE microcode is located. The
4765 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4768 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4769 The maximum possible size of the firmware. The firmware binary format
4770 has a field that specifies the actual size of the firmware, but it
4771 might not be possible to read any part of the firmware unless some
4772 local storage is allocated to hold the entire firmware first.
4774 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4775 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4776 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4777 virtual address in NOR flash.
4779 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4780 Specifies that QE/FMAN firmware is located in NAND flash.
4781 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4783 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4784 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4785 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4787 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4788 Specifies that QE/FMAN firmware is located in the remote (master)
4789 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4790 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4791 window->master inbound window->master LAW->the ucode address in
4792 master's memory space.
4794 Freescale Layerscape Management Complex Firmware Support:
4795 ---------------------------------------------------------
4796 The Freescale Layerscape Management Complex (MC) supports the loading of
4798 This firmware often needs to be loaded during U-Boot booting, so macros
4799 are used to identify the storage device (NOR flash, SPI, etc) and the address
4802 - CONFIG_FSL_MC_ENET
4803 Enable the MC driver for Layerscape SoCs.
4805 Freescale Layerscape Debug Server Support:
4806 -------------------------------------------
4807 The Freescale Layerscape Debug Server Support supports the loading of
4808 "Debug Server firmware" and triggering SP boot-rom.
4809 This firmware often needs to be loaded during U-Boot booting.
4811 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4812 Define alignment of reserved memory MC requires
4817 In order to achieve reproducible builds, timestamps used in the U-Boot build
4818 process have to be set to a fixed value.
4820 This is done using the SOURCE_DATE_EPOCH environment variable.
4821 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4822 option for U-Boot or an environment variable in U-Boot.
4824 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4826 Building the Software:
4827 ======================
4829 Building U-Boot has been tested in several native build environments
4830 and in many different cross environments. Of course we cannot support
4831 all possibly existing versions of cross development tools in all
4832 (potentially obsolete) versions. In case of tool chain problems we
4833 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4834 which is extensively used to build and test U-Boot.
4836 If you are not using a native environment, it is assumed that you
4837 have GNU cross compiling tools available in your path. In this case,
4838 you must set the environment variable CROSS_COMPILE in your shell.
4839 Note that no changes to the Makefile or any other source files are
4840 necessary. For example using the ELDK on a 4xx CPU, please enter:
4842 $ CROSS_COMPILE=ppc_4xx-
4843 $ export CROSS_COMPILE
4845 Note: If you wish to generate Windows versions of the utilities in
4846 the tools directory you can use the MinGW toolchain
4847 (http://www.mingw.org). Set your HOST tools to the MinGW
4848 toolchain and execute 'make tools'. For example:
4850 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4852 Binaries such as tools/mkimage.exe will be created which can
4853 be executed on computers running Windows.
4855 U-Boot is intended to be simple to build. After installing the
4856 sources you must configure U-Boot for one specific board type. This
4861 where "NAME_defconfig" is the name of one of the existing configu-
4862 rations; see boards.cfg for supported names.
4864 Note: for some board special configuration names may exist; check if
4865 additional information is available from the board vendor; for
4866 instance, the TQM823L systems are available without (standard)
4867 or with LCD support. You can select such additional "features"
4868 when choosing the configuration, i. e.
4870 make TQM823L_defconfig
4871 - will configure for a plain TQM823L, i. e. no LCD support
4873 make TQM823L_LCD_defconfig
4874 - will configure for a TQM823L with U-Boot console on LCD
4879 Finally, type "make all", and you should get some working U-Boot
4880 images ready for download to / installation on your system:
4882 - "u-boot.bin" is a raw binary image
4883 - "u-boot" is an image in ELF binary format
4884 - "u-boot.srec" is in Motorola S-Record format
4886 By default the build is performed locally and the objects are saved
4887 in the source directory. One of the two methods can be used to change
4888 this behavior and build U-Boot to some external directory:
4890 1. Add O= to the make command line invocations:
4892 make O=/tmp/build distclean
4893 make O=/tmp/build NAME_defconfig
4894 make O=/tmp/build all
4896 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4898 export KBUILD_OUTPUT=/tmp/build
4903 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4907 Please be aware that the Makefiles assume you are using GNU make, so
4908 for instance on NetBSD you might need to use "gmake" instead of
4912 If the system board that you have is not listed, then you will need
4913 to port U-Boot to your hardware platform. To do this, follow these
4916 1. Create a new directory to hold your board specific code. Add any
4917 files you need. In your board directory, you will need at least
4918 the "Makefile" and a "<board>.c".
4919 2. Create a new configuration file "include/configs/<board>.h" for
4921 3. If you're porting U-Boot to a new CPU, then also create a new
4922 directory to hold your CPU specific code. Add any files you need.
4923 4. Run "make <board>_defconfig" with your new name.
4924 5. Type "make", and you should get a working "u-boot.srec" file
4925 to be installed on your target system.
4926 6. Debug and solve any problems that might arise.
4927 [Of course, this last step is much harder than it sounds.]
4930 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4931 ==============================================================
4933 If you have modified U-Boot sources (for instance added a new board
4934 or support for new devices, a new CPU, etc.) you are expected to
4935 provide feedback to the other developers. The feedback normally takes
4936 the form of a "patch", i. e. a context diff against a certain (latest
4937 official or latest in the git repository) version of U-Boot sources.
4939 But before you submit such a patch, please verify that your modifi-
4940 cation did not break existing code. At least make sure that *ALL* of
4941 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4942 just run the buildman script (tools/buildman/buildman), which will
4943 configure and build U-Boot for ALL supported system. Be warned, this
4944 will take a while. Please see the buildman README, or run 'buildman -H'
4948 See also "U-Boot Porting Guide" below.
4951 Monitor Commands - Overview:
4952 ============================
4954 go - start application at address 'addr'
4955 run - run commands in an environment variable
4956 bootm - boot application image from memory
4957 bootp - boot image via network using BootP/TFTP protocol
4958 bootz - boot zImage from memory
4959 tftpboot- boot image via network using TFTP protocol
4960 and env variables "ipaddr" and "serverip"
4961 (and eventually "gatewayip")
4962 tftpput - upload a file via network using TFTP protocol
4963 rarpboot- boot image via network using RARP/TFTP protocol
4964 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4965 loads - load S-Record file over serial line
4966 loadb - load binary file over serial line (kermit mode)
4968 mm - memory modify (auto-incrementing)
4969 nm - memory modify (constant address)
4970 mw - memory write (fill)
4972 cmp - memory compare
4973 crc32 - checksum calculation
4974 i2c - I2C sub-system
4975 sspi - SPI utility commands
4976 base - print or set address offset
4977 printenv- print environment variables
4978 setenv - set environment variables
4979 saveenv - save environment variables to persistent storage
4980 protect - enable or disable FLASH write protection
4981 erase - erase FLASH memory
4982 flinfo - print FLASH memory information
4983 nand - NAND memory operations (see doc/README.nand)
4984 bdinfo - print Board Info structure
4985 iminfo - print header information for application image
4986 coninfo - print console devices and informations
4987 ide - IDE sub-system
4988 loop - infinite loop on address range
4989 loopw - infinite write loop on address range
4990 mtest - simple RAM test
4991 icache - enable or disable instruction cache
4992 dcache - enable or disable data cache
4993 reset - Perform RESET of the CPU
4994 echo - echo args to console
4995 version - print monitor version
4996 help - print online help
4997 ? - alias for 'help'
5000 Monitor Commands - Detailed Description:
5001 ========================================
5005 For now: just type "help <command>".
5008 Environment Variables:
5009 ======================
5011 U-Boot supports user configuration using Environment Variables which
5012 can be made persistent by saving to Flash memory.
5014 Environment Variables are set using "setenv", printed using
5015 "printenv", and saved to Flash using "saveenv". Using "setenv"
5016 without a value can be used to delete a variable from the
5017 environment. As long as you don't save the environment you are
5018 working with an in-memory copy. In case the Flash area containing the
5019 environment is erased by accident, a default environment is provided.
5021 Some configuration options can be set using Environment Variables.
5023 List of environment variables (most likely not complete):
5025 baudrate - see CONFIG_BAUDRATE
5027 bootdelay - see CONFIG_BOOTDELAY
5029 bootcmd - see CONFIG_BOOTCOMMAND
5031 bootargs - Boot arguments when booting an RTOS image
5033 bootfile - Name of the image to load with TFTP
5035 bootm_low - Memory range available for image processing in the bootm
5036 command can be restricted. This variable is given as
5037 a hexadecimal number and defines lowest address allowed
5038 for use by the bootm command. See also "bootm_size"
5039 environment variable. Address defined by "bootm_low" is
5040 also the base of the initial memory mapping for the Linux
5041 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5044 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5045 This variable is given as a hexadecimal number and it
5046 defines the size of the memory region starting at base
5047 address bootm_low that is accessible by the Linux kernel
5048 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5049 as the default value if it is defined, and bootm_size is
5052 bootm_size - Memory range available for image processing in the bootm
5053 command can be restricted. This variable is given as
5054 a hexadecimal number and defines the size of the region
5055 allowed for use by the bootm command. See also "bootm_low"
5056 environment variable.
5058 updatefile - Location of the software update file on a TFTP server, used
5059 by the automatic software update feature. Please refer to
5060 documentation in doc/README.update for more details.
5062 autoload - if set to "no" (any string beginning with 'n'),
5063 "bootp" will just load perform a lookup of the
5064 configuration from the BOOTP server, but not try to
5065 load any image using TFTP
5067 autostart - if set to "yes", an image loaded using the "bootp",
5068 "rarpboot", "tftpboot" or "diskboot" commands will
5069 be automatically started (by internally calling
5072 If set to "no", a standalone image passed to the
5073 "bootm" command will be copied to the load address
5074 (and eventually uncompressed), but NOT be started.
5075 This can be used to load and uncompress arbitrary
5078 fdt_high - if set this restricts the maximum address that the
5079 flattened device tree will be copied into upon boot.
5080 For example, if you have a system with 1 GB memory
5081 at physical address 0x10000000, while Linux kernel
5082 only recognizes the first 704 MB as low memory, you
5083 may need to set fdt_high as 0x3C000000 to have the
5084 device tree blob be copied to the maximum address
5085 of the 704 MB low memory, so that Linux kernel can
5086 access it during the boot procedure.
5088 If this is set to the special value 0xFFFFFFFF then
5089 the fdt will not be copied at all on boot. For this
5090 to work it must reside in writable memory, have
5091 sufficient padding on the end of it for u-boot to
5092 add the information it needs into it, and the memory
5093 must be accessible by the kernel.
5095 fdtcontroladdr- if set this is the address of the control flattened
5096 device tree used by U-Boot when CONFIG_OF_CONTROL is
5099 i2cfast - (PPC405GP|PPC405EP only)
5100 if set to 'y' configures Linux I2C driver for fast
5101 mode (400kHZ). This environment variable is used in
5102 initialization code. So, for changes to be effective
5103 it must be saved and board must be reset.
5105 initrd_high - restrict positioning of initrd images:
5106 If this variable is not set, initrd images will be
5107 copied to the highest possible address in RAM; this
5108 is usually what you want since it allows for
5109 maximum initrd size. If for some reason you want to
5110 make sure that the initrd image is loaded below the
5111 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5112 variable to a value of "no" or "off" or "0".
5113 Alternatively, you can set it to a maximum upper
5114 address to use (U-Boot will still check that it
5115 does not overwrite the U-Boot stack and data).
5117 For instance, when you have a system with 16 MB
5118 RAM, and want to reserve 4 MB from use by Linux,
5119 you can do this by adding "mem=12M" to the value of
5120 the "bootargs" variable. However, now you must make
5121 sure that the initrd image is placed in the first
5122 12 MB as well - this can be done with
5124 setenv initrd_high 00c00000
5126 If you set initrd_high to 0xFFFFFFFF, this is an
5127 indication to U-Boot that all addresses are legal
5128 for the Linux kernel, including addresses in flash
5129 memory. In this case U-Boot will NOT COPY the
5130 ramdisk at all. This may be useful to reduce the
5131 boot time on your system, but requires that this
5132 feature is supported by your Linux kernel.
5134 ipaddr - IP address; needed for tftpboot command
5136 loadaddr - Default load address for commands like "bootp",
5137 "rarpboot", "tftpboot", "loadb" or "diskboot"
5139 loads_echo - see CONFIG_LOADS_ECHO
5141 serverip - TFTP server IP address; needed for tftpboot command
5143 bootretry - see CONFIG_BOOT_RETRY_TIME
5145 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5147 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5149 ethprime - controls which interface is used first.
5151 ethact - controls which interface is currently active.
5152 For example you can do the following
5154 => setenv ethact FEC
5155 => ping 192.168.0.1 # traffic sent on FEC
5156 => setenv ethact SCC
5157 => ping 10.0.0.1 # traffic sent on SCC
5159 ethrotate - When set to "no" U-Boot does not go through all
5160 available network interfaces.
5161 It just stays at the currently selected interface.
5163 netretry - When set to "no" each network operation will
5164 either succeed or fail without retrying.
5165 When set to "once" the network operation will
5166 fail when all the available network interfaces
5167 are tried once without success.
5168 Useful on scripts which control the retry operation
5171 npe_ucode - set load address for the NPE microcode
5173 silent_linux - If set then Linux will be told to boot silently, by
5174 changing the console to be empty. If "yes" it will be
5175 made silent. If "no" it will not be made silent. If
5176 unset, then it will be made silent if the U-Boot console
5179 tftpsrcp - If this is set, the value is used for TFTP's
5182 tftpdstp - If this is set, the value is used for TFTP's UDP
5183 destination port instead of the Well Know Port 69.
5185 tftpblocksize - Block size to use for TFTP transfers; if not set,
5186 we use the TFTP server's default block size
5188 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5189 seconds, minimum value is 1000 = 1 second). Defines
5190 when a packet is considered to be lost so it has to
5191 be retransmitted. The default is 5000 = 5 seconds.
5192 Lowering this value may make downloads succeed
5193 faster in networks with high packet loss rates or
5194 with unreliable TFTP servers.
5196 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5197 unit, minimum value = 0). Defines how many timeouts
5198 can happen during a single file transfer before that
5199 transfer is aborted. The default is 10, and 0 means
5200 'no timeouts allowed'. Increasing this value may help
5201 downloads succeed with high packet loss rates, or with
5202 unreliable TFTP servers or client hardware.
5204 vlan - When set to a value < 4095 the traffic over
5205 Ethernet is encapsulated/received over 802.1q
5208 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5209 Unsigned value, in milliseconds. If not set, the period will
5210 be either the default (28000), or a value based on
5211 CONFIG_NET_RETRY_COUNT, if defined. This value has
5212 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5214 The following image location variables contain the location of images
5215 used in booting. The "Image" column gives the role of the image and is
5216 not an environment variable name. The other columns are environment
5217 variable names. "File Name" gives the name of the file on a TFTP
5218 server, "RAM Address" gives the location in RAM the image will be
5219 loaded to, and "Flash Location" gives the image's address in NOR
5220 flash or offset in NAND flash.
5222 *Note* - these variables don't have to be defined for all boards, some
5223 boards currently use other variables for these purposes, and some
5224 boards use these variables for other purposes.
5226 Image File Name RAM Address Flash Location
5227 ----- --------- ----------- --------------
5228 u-boot u-boot u-boot_addr_r u-boot_addr
5229 Linux kernel bootfile kernel_addr_r kernel_addr
5230 device tree blob fdtfile fdt_addr_r fdt_addr
5231 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5233 The following environment variables may be used and automatically
5234 updated by the network boot commands ("bootp" and "rarpboot"),
5235 depending the information provided by your boot server:
5237 bootfile - see above
5238 dnsip - IP address of your Domain Name Server
5239 dnsip2 - IP address of your secondary Domain Name Server
5240 gatewayip - IP address of the Gateway (Router) to use
5241 hostname - Target hostname
5243 netmask - Subnet Mask
5244 rootpath - Pathname of the root filesystem on the NFS server
5245 serverip - see above
5248 There are two special Environment Variables:
5250 serial# - contains hardware identification information such
5251 as type string and/or serial number
5252 ethaddr - Ethernet address
5254 These variables can be set only once (usually during manufacturing of
5255 the board). U-Boot refuses to delete or overwrite these variables
5256 once they have been set once.
5259 Further special Environment Variables:
5261 ver - Contains the U-Boot version string as printed
5262 with the "version" command. This variable is
5263 readonly (see CONFIG_VERSION_VARIABLE).
5266 Please note that changes to some configuration parameters may take
5267 only effect after the next boot (yes, that's just like Windoze :-).
5270 Callback functions for environment variables:
5271 ---------------------------------------------
5273 For some environment variables, the behavior of u-boot needs to change
5274 when their values are changed. This functionality allows functions to
5275 be associated with arbitrary variables. On creation, overwrite, or
5276 deletion, the callback will provide the opportunity for some side
5277 effect to happen or for the change to be rejected.
5279 The callbacks are named and associated with a function using the
5280 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5282 These callbacks are associated with variables in one of two ways. The
5283 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5284 in the board configuration to a string that defines a list of
5285 associations. The list must be in the following format:
5287 entry = variable_name[:callback_name]
5290 If the callback name is not specified, then the callback is deleted.
5291 Spaces are also allowed anywhere in the list.
5293 Callbacks can also be associated by defining the ".callbacks" variable
5294 with the same list format above. Any association in ".callbacks" will
5295 override any association in the static list. You can define
5296 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5297 ".callbacks" environment variable in the default or embedded environment.
5299 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5300 regular expression. This allows multiple variables to be connected to
5301 the same callback without explicitly listing them all out.
5304 Command Line Parsing:
5305 =====================
5307 There are two different command line parsers available with U-Boot:
5308 the old "simple" one, and the much more powerful "hush" shell:
5310 Old, simple command line parser:
5311 --------------------------------
5313 - supports environment variables (through setenv / saveenv commands)
5314 - several commands on one line, separated by ';'
5315 - variable substitution using "... ${name} ..." syntax
5316 - special characters ('$', ';') can be escaped by prefixing with '\',
5318 setenv bootcmd bootm \${address}
5319 - You can also escape text by enclosing in single apostrophes, for example:
5320 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5325 - similar to Bourne shell, with control structures like
5326 if...then...else...fi, for...do...done; while...do...done,
5327 until...do...done, ...
5328 - supports environment ("global") variables (through setenv / saveenv
5329 commands) and local shell variables (through standard shell syntax
5330 "name=value"); only environment variables can be used with "run"
5336 (1) If a command line (or an environment variable executed by a "run"
5337 command) contains several commands separated by semicolon, and
5338 one of these commands fails, then the remaining commands will be
5341 (2) If you execute several variables with one call to run (i. e.
5342 calling run with a list of variables as arguments), any failing
5343 command will cause "run" to terminate, i. e. the remaining
5344 variables are not executed.
5346 Note for Redundant Ethernet Interfaces:
5347 =======================================
5349 Some boards come with redundant Ethernet interfaces; U-Boot supports
5350 such configurations and is capable of automatic selection of a
5351 "working" interface when needed. MAC assignment works as follows:
5353 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5354 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5355 "eth1addr" (=>eth1), "eth2addr", ...
5357 If the network interface stores some valid MAC address (for instance
5358 in SROM), this is used as default address if there is NO correspon-
5359 ding setting in the environment; if the corresponding environment
5360 variable is set, this overrides the settings in the card; that means:
5362 o If the SROM has a valid MAC address, and there is no address in the
5363 environment, the SROM's address is used.
5365 o If there is no valid address in the SROM, and a definition in the
5366 environment exists, then the value from the environment variable is
5369 o If both the SROM and the environment contain a MAC address, and
5370 both addresses are the same, this MAC address is used.
5372 o If both the SROM and the environment contain a MAC address, and the
5373 addresses differ, the value from the environment is used and a
5376 o If neither SROM nor the environment contain a MAC address, an error
5377 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5378 a random, locally-assigned MAC is used.
5380 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5381 will be programmed into hardware as part of the initialization process. This
5382 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5383 The naming convention is as follows:
5384 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5389 U-Boot is capable of booting (and performing other auxiliary operations on)
5390 images in two formats:
5392 New uImage format (FIT)
5393 -----------------------
5395 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5396 to Flattened Device Tree). It allows the use of images with multiple
5397 components (several kernels, ramdisks, etc.), with contents protected by
5398 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5404 Old image format is based on binary files which can be basically anything,
5405 preceded by a special header; see the definitions in include/image.h for
5406 details; basically, the header defines the following image properties:
5408 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5409 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5410 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5411 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5413 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5414 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5415 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5416 * Compression Type (uncompressed, gzip, bzip2)
5422 The header is marked by a special Magic Number, and both the header
5423 and the data portions of the image are secured against corruption by
5430 Although U-Boot should support any OS or standalone application
5431 easily, the main focus has always been on Linux during the design of
5434 U-Boot includes many features that so far have been part of some
5435 special "boot loader" code within the Linux kernel. Also, any
5436 "initrd" images to be used are no longer part of one big Linux image;
5437 instead, kernel and "initrd" are separate images. This implementation
5438 serves several purposes:
5440 - the same features can be used for other OS or standalone
5441 applications (for instance: using compressed images to reduce the
5442 Flash memory footprint)
5444 - it becomes much easier to port new Linux kernel versions because
5445 lots of low-level, hardware dependent stuff are done by U-Boot
5447 - the same Linux kernel image can now be used with different "initrd"
5448 images; of course this also means that different kernel images can
5449 be run with the same "initrd". This makes testing easier (you don't
5450 have to build a new "zImage.initrd" Linux image when you just
5451 change a file in your "initrd"). Also, a field-upgrade of the
5452 software is easier now.
5458 Porting Linux to U-Boot based systems:
5459 ---------------------------------------
5461 U-Boot cannot save you from doing all the necessary modifications to
5462 configure the Linux device drivers for use with your target hardware
5463 (no, we don't intend to provide a full virtual machine interface to
5466 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5468 Just make sure your machine specific header file (for instance
5469 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5470 Information structure as we define in include/asm-<arch>/u-boot.h,
5471 and make sure that your definition of IMAP_ADDR uses the same value
5472 as your U-Boot configuration in CONFIG_SYS_IMMR.
5474 Note that U-Boot now has a driver model, a unified model for drivers.
5475 If you are adding a new driver, plumb it into driver model. If there
5476 is no uclass available, you are encouraged to create one. See
5480 Configuring the Linux kernel:
5481 -----------------------------
5483 No specific requirements for U-Boot. Make sure you have some root
5484 device (initial ramdisk, NFS) for your target system.
5487 Building a Linux Image:
5488 -----------------------
5490 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5491 not used. If you use recent kernel source, a new build target
5492 "uImage" will exist which automatically builds an image usable by
5493 U-Boot. Most older kernels also have support for a "pImage" target,
5494 which was introduced for our predecessor project PPCBoot and uses a
5495 100% compatible format.
5499 make TQM850L_defconfig
5504 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5505 encapsulate a compressed Linux kernel image with header information,
5506 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5508 * build a standard "vmlinux" kernel image (in ELF binary format):
5510 * convert the kernel into a raw binary image:
5512 ${CROSS_COMPILE}-objcopy -O binary \
5513 -R .note -R .comment \
5514 -S vmlinux linux.bin
5516 * compress the binary image:
5520 * package compressed binary image for U-Boot:
5522 mkimage -A ppc -O linux -T kernel -C gzip \
5523 -a 0 -e 0 -n "Linux Kernel Image" \
5524 -d linux.bin.gz uImage
5527 The "mkimage" tool can also be used to create ramdisk images for use
5528 with U-Boot, either separated from the Linux kernel image, or
5529 combined into one file. "mkimage" encapsulates the images with a 64
5530 byte header containing information about target architecture,
5531 operating system, image type, compression method, entry points, time
5532 stamp, CRC32 checksums, etc.
5534 "mkimage" can be called in two ways: to verify existing images and
5535 print the header information, or to build new images.
5537 In the first form (with "-l" option) mkimage lists the information
5538 contained in the header of an existing U-Boot image; this includes
5539 checksum verification:
5541 tools/mkimage -l image
5542 -l ==> list image header information
5544 The second form (with "-d" option) is used to build a U-Boot image
5545 from a "data file" which is used as image payload:
5547 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5548 -n name -d data_file image
5549 -A ==> set architecture to 'arch'
5550 -O ==> set operating system to 'os'
5551 -T ==> set image type to 'type'
5552 -C ==> set compression type 'comp'
5553 -a ==> set load address to 'addr' (hex)
5554 -e ==> set entry point to 'ep' (hex)
5555 -n ==> set image name to 'name'
5556 -d ==> use image data from 'datafile'
5558 Right now, all Linux kernels for PowerPC systems use the same load
5559 address (0x00000000), but the entry point address depends on the
5562 - 2.2.x kernels have the entry point at 0x0000000C,
5563 - 2.3.x and later kernels have the entry point at 0x00000000.
5565 So a typical call to build a U-Boot image would read:
5567 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5568 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5569 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5570 > examples/uImage.TQM850L
5571 Image Name: 2.4.4 kernel for TQM850L
5572 Created: Wed Jul 19 02:34:59 2000
5573 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5574 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5575 Load Address: 0x00000000
5576 Entry Point: 0x00000000
5578 To verify the contents of the image (or check for corruption):
5580 -> tools/mkimage -l examples/uImage.TQM850L
5581 Image Name: 2.4.4 kernel for TQM850L
5582 Created: Wed Jul 19 02:34:59 2000
5583 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5584 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5585 Load Address: 0x00000000
5586 Entry Point: 0x00000000
5588 NOTE: for embedded systems where boot time is critical you can trade
5589 speed for memory and install an UNCOMPRESSED image instead: this
5590 needs more space in Flash, but boots much faster since it does not
5591 need to be uncompressed:
5593 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5594 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5595 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5596 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5597 > examples/uImage.TQM850L-uncompressed
5598 Image Name: 2.4.4 kernel for TQM850L
5599 Created: Wed Jul 19 02:34:59 2000
5600 Image Type: PowerPC Linux Kernel Image (uncompressed)
5601 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5602 Load Address: 0x00000000
5603 Entry Point: 0x00000000
5606 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5607 when your kernel is intended to use an initial ramdisk:
5609 -> tools/mkimage -n 'Simple Ramdisk Image' \
5610 > -A ppc -O linux -T ramdisk -C gzip \
5611 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5612 Image Name: Simple Ramdisk Image
5613 Created: Wed Jan 12 14:01:50 2000
5614 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5615 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5616 Load Address: 0x00000000
5617 Entry Point: 0x00000000
5619 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5620 option performs the converse operation of the mkimage's second form (the "-d"
5621 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5624 tools/dumpimage -i image -T type -p position data_file
5625 -i ==> extract from the 'image' a specific 'data_file'
5626 -T ==> set image type to 'type'
5627 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5630 Installing a Linux Image:
5631 -------------------------
5633 To downloading a U-Boot image over the serial (console) interface,
5634 you must convert the image to S-Record format:
5636 objcopy -I binary -O srec examples/image examples/image.srec
5638 The 'objcopy' does not understand the information in the U-Boot
5639 image header, so the resulting S-Record file will be relative to
5640 address 0x00000000. To load it to a given address, you need to
5641 specify the target address as 'offset' parameter with the 'loads'
5644 Example: install the image to address 0x40100000 (which on the
5645 TQM8xxL is in the first Flash bank):
5647 => erase 40100000 401FFFFF
5653 ## Ready for S-Record download ...
5654 ~>examples/image.srec
5655 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5657 15989 15990 15991 15992
5658 [file transfer complete]
5660 ## Start Addr = 0x00000000
5663 You can check the success of the download using the 'iminfo' command;
5664 this includes a checksum verification so you can be sure no data
5665 corruption happened:
5669 ## Checking Image at 40100000 ...
5670 Image Name: 2.2.13 for initrd on TQM850L
5671 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5672 Data Size: 335725 Bytes = 327 kB = 0 MB
5673 Load Address: 00000000
5674 Entry Point: 0000000c
5675 Verifying Checksum ... OK
5681 The "bootm" command is used to boot an application that is stored in
5682 memory (RAM or Flash). In case of a Linux kernel image, the contents
5683 of the "bootargs" environment variable is passed to the kernel as
5684 parameters. You can check and modify this variable using the
5685 "printenv" and "setenv" commands:
5688 => printenv bootargs
5689 bootargs=root=/dev/ram
5691 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5693 => printenv bootargs
5694 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5697 ## Booting Linux kernel at 40020000 ...
5698 Image Name: 2.2.13 for NFS on TQM850L
5699 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5700 Data Size: 381681 Bytes = 372 kB = 0 MB
5701 Load Address: 00000000
5702 Entry Point: 0000000c
5703 Verifying Checksum ... OK
5704 Uncompressing Kernel Image ... OK
5705 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
5706 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5707 time_init: decrementer frequency = 187500000/60
5708 Calibrating delay loop... 49.77 BogoMIPS
5709 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5712 If you want to boot a Linux kernel with initial RAM disk, you pass
5713 the memory addresses of both the kernel and the initrd image (PPBCOOT
5714 format!) to the "bootm" command:
5716 => imi 40100000 40200000
5718 ## Checking Image at 40100000 ...
5719 Image Name: 2.2.13 for initrd on TQM850L
5720 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5721 Data Size: 335725 Bytes = 327 kB = 0 MB
5722 Load Address: 00000000
5723 Entry Point: 0000000c
5724 Verifying Checksum ... OK
5726 ## Checking Image at 40200000 ...
5727 Image Name: Simple Ramdisk Image
5728 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5729 Data Size: 566530 Bytes = 553 kB = 0 MB
5730 Load Address: 00000000
5731 Entry Point: 00000000
5732 Verifying Checksum ... OK
5734 => bootm 40100000 40200000
5735 ## Booting Linux kernel at 40100000 ...
5736 Image Name: 2.2.13 for initrd on TQM850L
5737 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5738 Data Size: 335725 Bytes = 327 kB = 0 MB
5739 Load Address: 00000000
5740 Entry Point: 0000000c
5741 Verifying Checksum ... OK
5742 Uncompressing Kernel Image ... OK
5743 ## Loading RAMDisk Image at 40200000 ...
5744 Image Name: Simple Ramdisk Image
5745 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5746 Data Size: 566530 Bytes = 553 kB = 0 MB
5747 Load Address: 00000000
5748 Entry Point: 00000000
5749 Verifying Checksum ... OK
5750 Loading Ramdisk ... OK
5751 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
5752 Boot arguments: root=/dev/ram
5753 time_init: decrementer frequency = 187500000/60
5754 Calibrating delay loop... 49.77 BogoMIPS
5756 RAMDISK: Compressed image found at block 0
5757 VFS: Mounted root (ext2 filesystem).
5761 Boot Linux and pass a flat device tree:
5764 First, U-Boot must be compiled with the appropriate defines. See the section
5765 titled "Linux Kernel Interface" above for a more in depth explanation. The
5766 following is an example of how to start a kernel and pass an updated
5772 oft=oftrees/mpc8540ads.dtb
5773 => tftp $oftaddr $oft
5774 Speed: 1000, full duplex
5776 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5777 Filename 'oftrees/mpc8540ads.dtb'.
5778 Load address: 0x300000
5781 Bytes transferred = 4106 (100a hex)
5782 => tftp $loadaddr $bootfile
5783 Speed: 1000, full duplex
5785 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5787 Load address: 0x200000
5788 Loading:############
5790 Bytes transferred = 1029407 (fb51f hex)
5795 => bootm $loadaddr - $oftaddr
5796 ## Booting image at 00200000 ...
5797 Image Name: Linux-2.6.17-dirty
5798 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5799 Data Size: 1029343 Bytes = 1005.2 kB
5800 Load Address: 00000000
5801 Entry Point: 00000000
5802 Verifying Checksum ... OK
5803 Uncompressing Kernel Image ... OK
5804 Booting using flat device tree at 0x300000
5805 Using MPC85xx ADS machine description
5806 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5810 More About U-Boot Image Types:
5811 ------------------------------
5813 U-Boot supports the following image types:
5815 "Standalone Programs" are directly runnable in the environment
5816 provided by U-Boot; it is expected that (if they behave
5817 well) you can continue to work in U-Boot after return from
5818 the Standalone Program.
5819 "OS Kernel Images" are usually images of some Embedded OS which
5820 will take over control completely. Usually these programs
5821 will install their own set of exception handlers, device
5822 drivers, set up the MMU, etc. - this means, that you cannot
5823 expect to re-enter U-Boot except by resetting the CPU.
5824 "RAMDisk Images" are more or less just data blocks, and their
5825 parameters (address, size) are passed to an OS kernel that is
5827 "Multi-File Images" contain several images, typically an OS
5828 (Linux) kernel image and one or more data images like
5829 RAMDisks. This construct is useful for instance when you want
5830 to boot over the network using BOOTP etc., where the boot
5831 server provides just a single image file, but you want to get
5832 for instance an OS kernel and a RAMDisk image.
5834 "Multi-File Images" start with a list of image sizes, each
5835 image size (in bytes) specified by an "uint32_t" in network
5836 byte order. This list is terminated by an "(uint32_t)0".
5837 Immediately after the terminating 0 follow the images, one by
5838 one, all aligned on "uint32_t" boundaries (size rounded up to
5839 a multiple of 4 bytes).
5841 "Firmware Images" are binary images containing firmware (like
5842 U-Boot or FPGA images) which usually will be programmed to
5845 "Script files" are command sequences that will be executed by
5846 U-Boot's command interpreter; this feature is especially
5847 useful when you configure U-Boot to use a real shell (hush)
5848 as command interpreter.
5850 Booting the Linux zImage:
5851 -------------------------
5853 On some platforms, it's possible to boot Linux zImage. This is done
5854 using the "bootz" command. The syntax of "bootz" command is the same
5855 as the syntax of "bootm" command.
5857 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5858 kernel with raw initrd images. The syntax is slightly different, the
5859 address of the initrd must be augmented by it's size, in the following
5860 format: "<initrd addres>:<initrd size>".
5866 One of the features of U-Boot is that you can dynamically load and
5867 run "standalone" applications, which can use some resources of
5868 U-Boot like console I/O functions or interrupt services.
5870 Two simple examples are included with the sources:
5875 'examples/hello_world.c' contains a small "Hello World" Demo
5876 application; it is automatically compiled when you build U-Boot.
5877 It's configured to run at address 0x00040004, so you can play with it
5881 ## Ready for S-Record download ...
5882 ~>examples/hello_world.srec
5883 1 2 3 4 5 6 7 8 9 10 11 ...
5884 [file transfer complete]
5886 ## Start Addr = 0x00040004
5888 => go 40004 Hello World! This is a test.
5889 ## Starting application at 0x00040004 ...
5900 Hit any key to exit ...
5902 ## Application terminated, rc = 0x0
5904 Another example, which demonstrates how to register a CPM interrupt
5905 handler with the U-Boot code, can be found in 'examples/timer.c'.
5906 Here, a CPM timer is set up to generate an interrupt every second.
5907 The interrupt service routine is trivial, just printing a '.'
5908 character, but this is just a demo program. The application can be
5909 controlled by the following keys:
5911 ? - print current values og the CPM Timer registers
5912 b - enable interrupts and start timer
5913 e - stop timer and disable interrupts
5914 q - quit application
5917 ## Ready for S-Record download ...
5918 ~>examples/timer.srec
5919 1 2 3 4 5 6 7 8 9 10 11 ...
5920 [file transfer complete]
5922 ## Start Addr = 0x00040004
5925 ## Starting application at 0x00040004 ...
5928 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5931 [q, b, e, ?] Set interval 1000000 us
5934 [q, b, e, ?] ........
5935 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5938 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5941 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5944 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5946 [q, b, e, ?] ...Stopping timer
5948 [q, b, e, ?] ## Application terminated, rc = 0x0
5954 Over time, many people have reported problems when trying to use the
5955 "minicom" terminal emulation program for serial download. I (wd)
5956 consider minicom to be broken, and recommend not to use it. Under
5957 Unix, I recommend to use C-Kermit for general purpose use (and
5958 especially for kermit binary protocol download ("loadb" command), and
5959 use "cu" for S-Record download ("loads" command). See
5960 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5961 for help with kermit.
5964 Nevertheless, if you absolutely want to use it try adding this
5965 configuration to your "File transfer protocols" section:
5967 Name Program Name U/D FullScr IO-Red. Multi
5968 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5969 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5975 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5976 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5978 Building requires a cross environment; it is known to work on
5979 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5980 need gmake since the Makefiles are not compatible with BSD make).
5981 Note that the cross-powerpc package does not install include files;
5982 attempting to build U-Boot will fail because <machine/ansi.h> is
5983 missing. This file has to be installed and patched manually:
5985 # cd /usr/pkg/cross/powerpc-netbsd/include
5987 # ln -s powerpc machine
5988 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5989 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5991 Native builds *don't* work due to incompatibilities between native
5992 and U-Boot include files.
5994 Booting assumes that (the first part of) the image booted is a
5995 stage-2 loader which in turn loads and then invokes the kernel
5996 proper. Loader sources will eventually appear in the NetBSD source
5997 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5998 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6001 Implementation Internals:
6002 =========================
6004 The following is not intended to be a complete description of every
6005 implementation detail. However, it should help to understand the
6006 inner workings of U-Boot and make it easier to port it to custom
6010 Initial Stack, Global Data:
6011 ---------------------------
6013 The implementation of U-Boot is complicated by the fact that U-Boot
6014 starts running out of ROM (flash memory), usually without access to
6015 system RAM (because the memory controller is not initialized yet).
6016 This means that we don't have writable Data or BSS segments, and BSS
6017 is not initialized as zero. To be able to get a C environment working
6018 at all, we have to allocate at least a minimal stack. Implementation
6019 options for this are defined and restricted by the CPU used: Some CPU
6020 models provide on-chip memory (like the IMMR area on MPC8xx and
6021 MPC826x processors), on others (parts of) the data cache can be
6022 locked as (mis-) used as memory, etc.
6024 Chris Hallinan posted a good summary of these issues to the
6025 U-Boot mailing list:
6027 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6028 From: "Chris Hallinan" <clh@net1plus.com>
6029 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6032 Correct me if I'm wrong, folks, but the way I understand it
6033 is this: Using DCACHE as initial RAM for Stack, etc, does not
6034 require any physical RAM backing up the cache. The cleverness
6035 is that the cache is being used as a temporary supply of
6036 necessary storage before the SDRAM controller is setup. It's
6037 beyond the scope of this list to explain the details, but you
6038 can see how this works by studying the cache architecture and
6039 operation in the architecture and processor-specific manuals.
6041 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6042 is another option for the system designer to use as an
6043 initial stack/RAM area prior to SDRAM being available. Either
6044 option should work for you. Using CS 4 should be fine if your
6045 board designers haven't used it for something that would
6046 cause you grief during the initial boot! It is frequently not
6049 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6050 with your processor/board/system design. The default value
6051 you will find in any recent u-boot distribution in
6052 walnut.h should work for you. I'd set it to a value larger
6053 than your SDRAM module. If you have a 64MB SDRAM module, set
6054 it above 400_0000. Just make sure your board has no resources
6055 that are supposed to respond to that address! That code in
6056 start.S has been around a while and should work as is when
6057 you get the config right.
6062 It is essential to remember this, since it has some impact on the C
6063 code for the initialization procedures:
6065 * Initialized global data (data segment) is read-only. Do not attempt
6068 * Do not use any uninitialized global data (or implicitly initialized
6069 as zero data - BSS segment) at all - this is undefined, initiali-
6070 zation is performed later (when relocating to RAM).
6072 * Stack space is very limited. Avoid big data buffers or things like
6075 Having only the stack as writable memory limits means we cannot use
6076 normal global data to share information between the code. But it
6077 turned out that the implementation of U-Boot can be greatly
6078 simplified by making a global data structure (gd_t) available to all
6079 functions. We could pass a pointer to this data as argument to _all_
6080 functions, but this would bloat the code. Instead we use a feature of
6081 the GCC compiler (Global Register Variables) to share the data: we
6082 place a pointer (gd) to the global data into a register which we
6083 reserve for this purpose.
6085 When choosing a register for such a purpose we are restricted by the
6086 relevant (E)ABI specifications for the current architecture, and by
6087 GCC's implementation.
6089 For PowerPC, the following registers have specific use:
6091 R2: reserved for system use
6092 R3-R4: parameter passing and return values
6093 R5-R10: parameter passing
6094 R13: small data area pointer
6098 (U-Boot also uses R12 as internal GOT pointer. r12
6099 is a volatile register so r12 needs to be reset when
6100 going back and forth between asm and C)
6102 ==> U-Boot will use R2 to hold a pointer to the global data
6104 Note: on PPC, we could use a static initializer (since the
6105 address of the global data structure is known at compile time),
6106 but it turned out that reserving a register results in somewhat
6107 smaller code - although the code savings are not that big (on
6108 average for all boards 752 bytes for the whole U-Boot image,
6109 624 text + 127 data).
6111 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6112 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6114 ==> U-Boot will use P3 to hold a pointer to the global data
6116 On ARM, the following registers are used:
6118 R0: function argument word/integer result
6119 R1-R3: function argument word
6120 R9: platform specific
6121 R10: stack limit (used only if stack checking is enabled)
6122 R11: argument (frame) pointer
6123 R12: temporary workspace
6126 R15: program counter
6128 ==> U-Boot will use R9 to hold a pointer to the global data
6130 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6132 On Nios II, the ABI is documented here:
6133 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6135 ==> U-Boot will use gp to hold a pointer to the global data
6137 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6138 to access small data sections, so gp is free.
6140 On NDS32, the following registers are used:
6142 R0-R1: argument/return
6144 R15: temporary register for assembler
6145 R16: trampoline register
6146 R28: frame pointer (FP)
6147 R29: global pointer (GP)
6148 R30: link register (LP)
6149 R31: stack pointer (SP)
6150 PC: program counter (PC)
6152 ==> U-Boot will use R10 to hold a pointer to the global data
6154 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6155 or current versions of GCC may "optimize" the code too much.
6160 U-Boot runs in system state and uses physical addresses, i.e. the
6161 MMU is not used either for address mapping nor for memory protection.
6163 The available memory is mapped to fixed addresses using the memory
6164 controller. In this process, a contiguous block is formed for each
6165 memory type (Flash, SDRAM, SRAM), even when it consists of several
6166 physical memory banks.
6168 U-Boot is installed in the first 128 kB of the first Flash bank (on
6169 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6170 booting and sizing and initializing DRAM, the code relocates itself
6171 to the upper end of DRAM. Immediately below the U-Boot code some
6172 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6173 configuration setting]. Below that, a structure with global Board
6174 Info data is placed, followed by the stack (growing downward).
6176 Additionally, some exception handler code is copied to the low 8 kB
6177 of DRAM (0x00000000 ... 0x00001FFF).
6179 So a typical memory configuration with 16 MB of DRAM could look like
6182 0x0000 0000 Exception Vector code
6185 0x0000 2000 Free for Application Use
6191 0x00FB FF20 Monitor Stack (Growing downward)
6192 0x00FB FFAC Board Info Data and permanent copy of global data
6193 0x00FC 0000 Malloc Arena
6196 0x00FE 0000 RAM Copy of Monitor Code
6197 ... eventually: LCD or video framebuffer
6198 ... eventually: pRAM (Protected RAM - unchanged by reset)
6199 0x00FF FFFF [End of RAM]
6202 System Initialization:
6203 ----------------------
6205 In the reset configuration, U-Boot starts at the reset entry point
6206 (on most PowerPC systems at address 0x00000100). Because of the reset
6207 configuration for CS0# this is a mirror of the on board Flash memory.
6208 To be able to re-map memory U-Boot then jumps to its link address.
6209 To be able to implement the initialization code in C, a (small!)
6210 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6211 which provide such a feature like MPC8xx or MPC8260), or in a locked
6212 part of the data cache. After that, U-Boot initializes the CPU core,
6213 the caches and the SIU.
6215 Next, all (potentially) available memory banks are mapped using a
6216 preliminary mapping. For example, we put them on 512 MB boundaries
6217 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6218 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6219 programmed for SDRAM access. Using the temporary configuration, a
6220 simple memory test is run that determines the size of the SDRAM
6223 When there is more than one SDRAM bank, and the banks are of
6224 different size, the largest is mapped first. For equal size, the first
6225 bank (CS2#) is mapped first. The first mapping is always for address
6226 0x00000000, with any additional banks following immediately to create
6227 contiguous memory starting from 0.
6229 Then, the monitor installs itself at the upper end of the SDRAM area
6230 and allocates memory for use by malloc() and for the global Board
6231 Info data; also, the exception vector code is copied to the low RAM
6232 pages, and the final stack is set up.
6234 Only after this relocation will you have a "normal" C environment;
6235 until that you are restricted in several ways, mostly because you are
6236 running from ROM, and because the code will have to be relocated to a
6240 U-Boot Porting Guide:
6241 ----------------------
6243 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6247 int main(int argc, char *argv[])
6249 sighandler_t no_more_time;
6251 signal(SIGALRM, no_more_time);
6252 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6254 if (available_money > available_manpower) {
6255 Pay consultant to port U-Boot;
6259 Download latest U-Boot source;
6261 Subscribe to u-boot mailing list;
6264 email("Hi, I am new to U-Boot, how do I get started?");
6267 Read the README file in the top level directory;
6268 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6269 Read applicable doc/*.README;
6270 Read the source, Luke;
6271 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6274 if (available_money > toLocalCurrency ($2500))
6277 Add a lot of aggravation and time;
6279 if (a similar board exists) { /* hopefully... */
6280 cp -a board/<similar> board/<myboard>
6281 cp include/configs/<similar>.h include/configs/<myboard>.h
6283 Create your own board support subdirectory;
6284 Create your own board include/configs/<myboard>.h file;
6286 Edit new board/<myboard> files
6287 Edit new include/configs/<myboard>.h
6292 Add / modify source code;
6296 email("Hi, I am having problems...");
6298 Send patch file to the U-Boot email list;
6299 if (reasonable critiques)
6300 Incorporate improvements from email list code review;
6302 Defend code as written;
6308 void no_more_time (int sig)
6317 All contributions to U-Boot should conform to the Linux kernel
6318 coding style; see the file "Documentation/CodingStyle" and the script
6319 "scripts/Lindent" in your Linux kernel source directory.
6321 Source files originating from a different project (for example the
6322 MTD subsystem) are generally exempt from these guidelines and are not
6323 reformatted to ease subsequent migration to newer versions of those
6326 Please note that U-Boot is implemented in C (and to some small parts in
6327 Assembler); no C++ is used, so please do not use C++ style comments (//)
6330 Please also stick to the following formatting rules:
6331 - remove any trailing white space
6332 - use TAB characters for indentation and vertical alignment, not spaces
6333 - make sure NOT to use DOS '\r\n' line feeds
6334 - do not add more than 2 consecutive empty lines to source files
6335 - do not add trailing empty lines to source files
6337 Submissions which do not conform to the standards may be returned
6338 with a request to reformat the changes.
6344 Since the number of patches for U-Boot is growing, we need to
6345 establish some rules. Submissions which do not conform to these rules
6346 may be rejected, even when they contain important and valuable stuff.
6348 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6350 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6351 see http://lists.denx.de/mailman/listinfo/u-boot
6353 When you send a patch, please include the following information with
6356 * For bug fixes: a description of the bug and how your patch fixes
6357 this bug. Please try to include a way of demonstrating that the
6358 patch actually fixes something.
6360 * For new features: a description of the feature and your
6363 * A CHANGELOG entry as plaintext (separate from the patch)
6365 * For major contributions, add a MAINTAINERS file with your
6366 information and associated file and directory references.
6368 * When you add support for a new board, don't forget to add a
6369 maintainer e-mail address to the boards.cfg file, too.
6371 * If your patch adds new configuration options, don't forget to
6372 document these in the README file.
6374 * The patch itself. If you are using git (which is *strongly*
6375 recommended) you can easily generate the patch using the
6376 "git format-patch". If you then use "git send-email" to send it to
6377 the U-Boot mailing list, you will avoid most of the common problems
6378 with some other mail clients.
6380 If you cannot use git, use "diff -purN OLD NEW". If your version of
6381 diff does not support these options, then get the latest version of
6384 The current directory when running this command shall be the parent
6385 directory of the U-Boot source tree (i. e. please make sure that
6386 your patch includes sufficient directory information for the
6389 We prefer patches as plain text. MIME attachments are discouraged,
6390 and compressed attachments must not be used.
6392 * If one logical set of modifications affects or creates several
6393 files, all these changes shall be submitted in a SINGLE patch file.
6395 * Changesets that contain different, unrelated modifications shall be
6396 submitted as SEPARATE patches, one patch per changeset.
6401 * Before sending the patch, run the buildman script on your patched
6402 source tree and make sure that no errors or warnings are reported
6403 for any of the boards.
6405 * Keep your modifications to the necessary minimum: A patch
6406 containing several unrelated changes or arbitrary reformats will be
6407 returned with a request to re-formatting / split it.
6409 * If you modify existing code, make sure that your new code does not
6410 add to the memory footprint of the code ;-) Small is beautiful!
6411 When adding new features, these should compile conditionally only
6412 (using #ifdef), and the resulting code with the new feature
6413 disabled must not need more memory than the old code without your
6416 * Remember that there is a size limit of 100 kB per message on the
6417 u-boot mailing list. Bigger patches will be moderated. If they are
6418 reasonable and not too big, they will be acknowledged. But patches
6419 bigger than the size limit should be avoided.