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 When CONFIG_SILENT_CONSOLE is defined, all console
817 messages (by U-Boot and Linux!) can be silenced with
818 the "silent" environment variable. See
819 doc/README.silent for more information.
821 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
823 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
827 CONFIG_BAUDRATE - in bps
828 Select one of the baudrates listed in
829 CONFIG_SYS_BAUDRATE_TABLE, see below.
830 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
832 - Console Rx buffer length
833 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
834 the maximum receive buffer length for the SMC.
835 This option is actual only for 82xx and 8xx possible.
836 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
837 must be defined, to setup the maximum idle timeout for
840 - Pre-Console Buffer:
841 Prior to the console being initialised (i.e. serial UART
842 initialised etc) all console output is silently discarded.
843 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
844 buffer any console messages prior to the console being
845 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
846 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
847 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
848 bytes are output before the console is initialised, the
849 earlier bytes are discarded.
851 Note that when printing the buffer a copy is made on the
852 stack so CONFIG_PRE_CON_BUF_SZ must fit on the stack.
854 'Sane' compilers will generate smaller code if
855 CONFIG_PRE_CON_BUF_SZ is a power of 2
859 Only needed when CONFIG_BOOTDELAY is enabled;
860 define a command string that is automatically executed
861 when no character is read on the console interface
862 within "Boot Delay" after reset.
865 This can be used to pass arguments to the bootm
866 command. The value of CONFIG_BOOTARGS goes into the
867 environment value "bootargs".
869 CONFIG_RAMBOOT and CONFIG_NFSBOOT
870 The value of these goes into the environment as
871 "ramboot" and "nfsboot" respectively, and can be used
872 as a convenience, when switching between booting from
876 CONFIG_BOOTCOUNT_LIMIT
877 Implements a mechanism for detecting a repeating reboot
879 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
882 If no softreset save registers are found on the hardware
883 "bootcount" is stored in the environment. To prevent a
884 saveenv on all reboots, the environment variable
885 "upgrade_available" is used. If "upgrade_available" is
886 0, "bootcount" is always 0, if "upgrade_available" is
887 1 "bootcount" is incremented in the environment.
888 So the Userspace Applikation must set the "upgrade_available"
889 and "bootcount" variable to 0, if a boot was successfully.
894 When this option is #defined, the existence of the
895 environment variable "preboot" will be checked
896 immediately before starting the CONFIG_BOOTDELAY
897 countdown and/or running the auto-boot command resp.
898 entering interactive mode.
900 This feature is especially useful when "preboot" is
901 automatically generated or modified. For an example
902 see the LWMON board specific code: here "preboot" is
903 modified when the user holds down a certain
904 combination of keys on the (special) keyboard when
907 - Serial Download Echo Mode:
909 If defined to 1, all characters received during a
910 serial download (using the "loads" command) are
911 echoed back. This might be needed by some terminal
912 emulations (like "cu"), but may as well just take
913 time on others. This setting #define's the initial
914 value of the "loads_echo" environment variable.
916 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
918 Select one of the baudrates listed in
919 CONFIG_SYS_BAUDRATE_TABLE, see below.
922 Monitor commands can be included or excluded
923 from the build by using the #include files
924 <config_cmd_all.h> and #undef'ing unwanted
925 commands, or adding #define's for wanted commands.
927 The default command configuration includes all commands
928 except those marked below with a "*".
930 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
931 CONFIG_CMD_ASKENV * ask for env variable
932 CONFIG_CMD_BDI bdinfo
933 CONFIG_CMD_BEDBUG * Include BedBug Debugger
934 CONFIG_CMD_BMP * BMP support
935 CONFIG_CMD_BSP * Board specific commands
936 CONFIG_CMD_BOOTD bootd
937 CONFIG_CMD_BOOTI * ARM64 Linux kernel Image support
938 CONFIG_CMD_CACHE * icache, dcache
939 CONFIG_CMD_CLK * clock command support
940 CONFIG_CMD_CONSOLE coninfo
941 CONFIG_CMD_CRC32 * crc32
942 CONFIG_CMD_DATE * support for RTC, date/time...
943 CONFIG_CMD_DHCP * DHCP support
944 CONFIG_CMD_DIAG * Diagnostics
945 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
946 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
947 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
948 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
949 CONFIG_CMD_DTT * Digital Therm and Thermostat
950 CONFIG_CMD_ECHO echo arguments
951 CONFIG_CMD_EDITENV edit env variable
952 CONFIG_CMD_EEPROM * EEPROM read/write support
953 CONFIG_CMD_EEPROM_LAYOUT* EEPROM layout aware commands
954 CONFIG_CMD_ELF * bootelf, bootvx
955 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
956 CONFIG_CMD_ENV_FLAGS * display details about env flags
957 CONFIG_CMD_ENV_EXISTS * check existence of env variable
958 CONFIG_CMD_EXPORTENV * export the environment
959 CONFIG_CMD_EXT2 * ext2 command support
960 CONFIG_CMD_EXT4 * ext4 command support
961 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
962 that work for multiple fs types
963 CONFIG_CMD_FS_UUID * Look up a filesystem UUID
964 CONFIG_CMD_SAVEENV saveenv
965 CONFIG_CMD_FDC * Floppy Disk Support
966 CONFIG_CMD_FAT * FAT command support
967 CONFIG_CMD_FLASH flinfo, erase, protect
968 CONFIG_CMD_FPGA FPGA device initialization support
969 CONFIG_CMD_FUSE * Device fuse support
970 CONFIG_CMD_GETTIME * Get time since boot
971 CONFIG_CMD_GO * the 'go' command (exec code)
972 CONFIG_CMD_GREPENV * search environment
973 CONFIG_CMD_HASH * calculate hash / digest
974 CONFIG_CMD_I2C * I2C serial bus support
975 CONFIG_CMD_IDE * IDE harddisk support
976 CONFIG_CMD_IMI iminfo
977 CONFIG_CMD_IMLS List all images found in NOR flash
978 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
979 CONFIG_CMD_IMMAP * IMMR dump support
980 CONFIG_CMD_IOTRACE * I/O tracing for debugging
981 CONFIG_CMD_IMPORTENV * import an environment
982 CONFIG_CMD_INI * import data from an ini file into the env
983 CONFIG_CMD_IRQ * irqinfo
984 CONFIG_CMD_ITEST Integer/string test of 2 values
985 CONFIG_CMD_JFFS2 * JFFS2 Support
986 CONFIG_CMD_KGDB * kgdb
987 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
988 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
990 CONFIG_CMD_LOADB loadb
991 CONFIG_CMD_LOADS loads
992 CONFIG_CMD_MD5SUM * print md5 message digest
993 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
994 CONFIG_CMD_MEMINFO * Display detailed memory information
995 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
997 CONFIG_CMD_MEMTEST * mtest
998 CONFIG_CMD_MISC Misc functions like sleep etc
999 CONFIG_CMD_MMC * MMC memory mapped support
1000 CONFIG_CMD_MII * MII utility commands
1001 CONFIG_CMD_MTDPARTS * MTD partition support
1002 CONFIG_CMD_NAND * NAND support
1003 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1004 CONFIG_CMD_NFS NFS support
1005 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1006 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1007 CONFIG_CMD_PCI * pciinfo
1008 CONFIG_CMD_PCMCIA * PCMCIA support
1009 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1011 CONFIG_CMD_PORTIO * Port I/O
1012 CONFIG_CMD_READ * Read raw data from partition
1013 CONFIG_CMD_REGINFO * Register dump
1014 CONFIG_CMD_RUN run command in env variable
1015 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1016 CONFIG_CMD_SAVES * save S record dump
1017 CONFIG_SCSI * SCSI Support
1018 CONFIG_CMD_SDRAM * print SDRAM configuration information
1019 (requires CONFIG_CMD_I2C)
1020 CONFIG_CMD_SETGETDCR Support for DCR Register access
1022 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1023 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1024 (requires CONFIG_CMD_MEMORY)
1025 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1026 CONFIG_CMD_SOURCE "source" command Support
1027 CONFIG_CMD_SPI * SPI serial bus support
1028 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1029 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1030 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1031 CONFIG_CMD_TIMER * access to the system tick timer
1032 CONFIG_CMD_USB * USB support
1033 CONFIG_CMD_CDP * Cisco Discover Protocol support
1034 CONFIG_CMD_MFSL * Microblaze FSL support
1035 CONFIG_CMD_XIMG Load part of Multi Image
1036 CONFIG_CMD_UUID * Generate random UUID or GUID string
1038 EXAMPLE: If you want all functions except of network
1039 support you can write:
1041 #include "config_cmd_all.h"
1042 #undef CONFIG_CMD_NET
1045 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1047 Note: Don't enable the "icache" and "dcache" commands
1048 (configuration option CONFIG_CMD_CACHE) unless you know
1049 what you (and your U-Boot users) are doing. Data
1050 cache cannot be enabled on systems like the 8xx or
1051 8260 (where accesses to the IMMR region must be
1052 uncached), and it cannot be disabled on all other
1053 systems where we (mis-) use the data cache to hold an
1054 initial stack and some data.
1057 XXX - this list needs to get updated!
1059 - Removal of commands
1060 If no commands are needed to boot, you can disable
1061 CONFIG_CMDLINE to remove them. In this case, the command line
1062 will not be available, and when U-Boot wants to execute the
1063 boot command (on start-up) it will call board_run_command()
1064 instead. This can reduce image size significantly for very
1065 simple boot procedures.
1067 - Regular expression support:
1069 If this variable is defined, U-Boot is linked against
1070 the SLRE (Super Light Regular Expression) library,
1071 which adds regex support to some commands, as for
1072 example "env grep" and "setexpr".
1076 If this variable is defined, U-Boot will use a device tree
1077 to configure its devices, instead of relying on statically
1078 compiled #defines in the board file. This option is
1079 experimental and only available on a few boards. The device
1080 tree is available in the global data as gd->fdt_blob.
1082 U-Boot needs to get its device tree from somewhere. This can
1083 be done using one of the two options below:
1086 If this variable is defined, U-Boot will embed a device tree
1087 binary in its image. This device tree file should be in the
1088 board directory and called <soc>-<board>.dts. The binary file
1089 is then picked up in board_init_f() and made available through
1090 the global data structure as gd->blob.
1093 If this variable is defined, U-Boot will build a device tree
1094 binary. It will be called u-boot.dtb. Architecture-specific
1095 code will locate it at run-time. Generally this works by:
1097 cat u-boot.bin u-boot.dtb >image.bin
1099 and in fact, U-Boot does this for you, creating a file called
1100 u-boot-dtb.bin which is useful in the common case. You can
1101 still use the individual files if you need something more
1106 If this variable is defined, it enables watchdog
1107 support for the SoC. There must be support in the SoC
1108 specific code for a watchdog. For the 8xx and 8260
1109 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1110 register. When supported for a specific SoC is
1111 available, then no further board specific code should
1112 be needed to use it.
1115 When using a watchdog circuitry external to the used
1116 SoC, then define this variable and provide board
1117 specific code for the "hw_watchdog_reset" function.
1119 CONFIG_AT91_HW_WDT_TIMEOUT
1120 specify the timeout in seconds. default 2 seconds.
1123 CONFIG_VERSION_VARIABLE
1124 If this variable is defined, an environment variable
1125 named "ver" is created by U-Boot showing the U-Boot
1126 version as printed by the "version" command.
1127 Any change to this variable will be reverted at the
1132 When CONFIG_CMD_DATE is selected, the type of the RTC
1133 has to be selected, too. Define exactly one of the
1136 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1137 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1138 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1139 CONFIG_RTC_MC146818 - use MC146818 RTC
1140 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1141 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1142 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1143 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
1144 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1145 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1146 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1147 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1148 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1151 Note that if the RTC uses I2C, then the I2C interface
1152 must also be configured. See I2C Support, below.
1155 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1157 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1158 chip-ngpio pairs that tell the PCA953X driver the number of
1159 pins supported by a particular chip.
1161 Note that if the GPIO device uses I2C, then the I2C interface
1162 must also be configured. See I2C Support, below.
1165 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1166 accesses and can checksum them or write a list of them out
1167 to memory. See the 'iotrace' command for details. This is
1168 useful for testing device drivers since it can confirm that
1169 the driver behaves the same way before and after a code
1170 change. Currently this is supported on sandbox and arm. To
1171 add support for your architecture, add '#include <iotrace.h>'
1172 to the bottom of arch/<arch>/include/asm/io.h and test.
1174 Example output from the 'iotrace stats' command is below.
1175 Note that if the trace buffer is exhausted, the checksum will
1176 still continue to operate.
1179 Start: 10000000 (buffer start address)
1180 Size: 00010000 (buffer size)
1181 Offset: 00000120 (current buffer offset)
1182 Output: 10000120 (start + offset)
1183 Count: 00000018 (number of trace records)
1184 CRC32: 9526fb66 (CRC32 of all trace records)
1186 - Timestamp Support:
1188 When CONFIG_TIMESTAMP is selected, the timestamp
1189 (date and time) of an image is printed by image
1190 commands like bootm or iminfo. This option is
1191 automatically enabled when you select CONFIG_CMD_DATE .
1193 - Partition Labels (disklabels) Supported:
1194 Zero or more of the following:
1195 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1196 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1197 Intel architecture, USB sticks, etc.
1198 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1199 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1200 bootloader. Note 2TB partition limit; see
1202 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1204 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1205 CONFIG_SCSI) you must configure support for at
1206 least one non-MTD partition type as well.
1209 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1210 board configurations files but used nowhere!
1212 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1213 be performed by calling the function
1214 ide_set_reset(int reset)
1215 which has to be defined in a board specific file
1220 Set this to enable ATAPI support.
1225 Set this to enable support for disks larger than 137GB
1226 Also look at CONFIG_SYS_64BIT_LBA.
1227 Whithout these , LBA48 support uses 32bit variables and will 'only'
1228 support disks up to 2.1TB.
1230 CONFIG_SYS_64BIT_LBA:
1231 When enabled, makes the IDE subsystem use 64bit sector addresses.
1235 At the moment only there is only support for the
1236 SYM53C8XX SCSI controller; define
1237 CONFIG_SCSI_SYM53C8XX to enable it.
1239 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1240 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1241 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1242 maximum numbers of LUNs, SCSI ID's and target
1244 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1246 The environment variable 'scsidevs' is set to the number of
1247 SCSI devices found during the last scan.
1249 - NETWORK Support (PCI):
1251 Support for Intel 8254x/8257x gigabit chips.
1254 Utility code for direct access to the SPI bus on Intel 8257x.
1255 This does not do anything useful unless you set at least one
1256 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1258 CONFIG_E1000_SPI_GENERIC
1259 Allow generic access to the SPI bus on the Intel 8257x, for
1260 example with the "sspi" command.
1263 Management command for E1000 devices. When used on devices
1264 with SPI support you can reprogram the EEPROM from U-Boot.
1267 Support for Intel 82557/82559/82559ER chips.
1268 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1269 write routine for first time initialisation.
1272 Support for Digital 2114x chips.
1273 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1274 modem chip initialisation (KS8761/QS6611).
1277 Support for National dp83815 chips.
1280 Support for National dp8382[01] gigabit chips.
1282 - NETWORK Support (other):
1284 CONFIG_DRIVER_AT91EMAC
1285 Support for AT91RM9200 EMAC.
1288 Define this to use reduced MII inteface
1290 CONFIG_DRIVER_AT91EMAC_QUIET
1291 If this defined, the driver is quiet.
1292 The driver doen't show link status messages.
1294 CONFIG_CALXEDA_XGMAC
1295 Support for the Calxeda XGMAC device
1298 Support for SMSC's LAN91C96 chips.
1300 CONFIG_LAN91C96_BASE
1301 Define this to hold the physical address
1302 of the LAN91C96's I/O space
1304 CONFIG_LAN91C96_USE_32_BIT
1305 Define this to enable 32 bit addressing
1308 Support for SMSC's LAN91C111 chip
1310 CONFIG_SMC91111_BASE
1311 Define this to hold the physical address
1312 of the device (I/O space)
1314 CONFIG_SMC_USE_32_BIT
1315 Define this if data bus is 32 bits
1317 CONFIG_SMC_USE_IOFUNCS
1318 Define this to use i/o functions instead of macros
1319 (some hardware wont work with macros)
1321 CONFIG_DRIVER_TI_EMAC
1322 Support for davinci emac
1324 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1325 Define this if you have more then 3 PHYs.
1328 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1330 CONFIG_FTGMAC100_EGIGA
1331 Define this to use GE link update with gigabit PHY.
1332 Define this if FTGMAC100 is connected to gigabit PHY.
1333 If your system has 10/100 PHY only, it might not occur
1334 wrong behavior. Because PHY usually return timeout or
1335 useless data when polling gigabit status and gigabit
1336 control registers. This behavior won't affect the
1337 correctnessof 10/100 link speed update.
1340 Support for SMSC's LAN911x and LAN921x chips
1343 Define this to hold the physical address
1344 of the device (I/O space)
1346 CONFIG_SMC911X_32_BIT
1347 Define this if data bus is 32 bits
1349 CONFIG_SMC911X_16_BIT
1350 Define this if data bus is 16 bits. If your processor
1351 automatically converts one 32 bit word to two 16 bit
1352 words you may also try CONFIG_SMC911X_32_BIT.
1355 Support for Renesas on-chip Ethernet controller
1357 CONFIG_SH_ETHER_USE_PORT
1358 Define the number of ports to be used
1360 CONFIG_SH_ETHER_PHY_ADDR
1361 Define the ETH PHY's address
1363 CONFIG_SH_ETHER_CACHE_WRITEBACK
1364 If this option is set, the driver enables cache flush.
1368 Support for PWM modul on the imx6.
1372 Support TPM devices.
1374 CONFIG_TPM_TIS_INFINEON
1375 Support for Infineon i2c bus TPM devices. Only one device
1376 per system is supported at this time.
1378 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1379 Define the burst count bytes upper limit
1382 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1384 CONFIG_TPM_ST33ZP24_I2C
1385 Support for STMicroelectronics ST33ZP24 I2C devices.
1386 Requires TPM_ST33ZP24 and I2C.
1388 CONFIG_TPM_ST33ZP24_SPI
1389 Support for STMicroelectronics ST33ZP24 SPI devices.
1390 Requires TPM_ST33ZP24 and SPI.
1392 CONFIG_TPM_ATMEL_TWI
1393 Support for Atmel TWI TPM device. Requires I2C support.
1396 Support for generic parallel port TPM devices. Only one device
1397 per system is supported at this time.
1399 CONFIG_TPM_TIS_BASE_ADDRESS
1400 Base address where the generic TPM device is mapped
1401 to. Contemporary x86 systems usually map it at
1405 Add tpm monitor functions.
1406 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1407 provides monitor access to authorized functions.
1410 Define this to enable the TPM support library which provides
1411 functional interfaces to some TPM commands.
1412 Requires support for a TPM device.
1414 CONFIG_TPM_AUTH_SESSIONS
1415 Define this to enable authorized functions in the TPM library.
1416 Requires CONFIG_TPM and CONFIG_SHA1.
1419 At the moment only the UHCI host controller is
1420 supported (PIP405, MIP405, MPC5200); define
1421 CONFIG_USB_UHCI to enable it.
1422 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1423 and define CONFIG_USB_STORAGE to enable the USB
1426 Supported are USB Keyboards and USB Floppy drives
1428 MPC5200 USB requires additional defines:
1430 for 528 MHz Clock: 0x0001bbbb
1434 for differential drivers: 0x00001000
1435 for single ended drivers: 0x00005000
1436 for differential drivers on PSC3: 0x00000100
1437 for single ended drivers on PSC3: 0x00004100
1438 CONFIG_SYS_USB_EVENT_POLL
1439 May be defined to allow interrupt polling
1440 instead of using asynchronous interrupts
1442 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1443 txfilltuning field in the EHCI controller on reset.
1445 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1446 HW module registers.
1449 Define the below if you wish to use the USB console.
1450 Once firmware is rebuilt from a serial console issue the
1451 command "setenv stdin usbtty; setenv stdout usbtty" and
1452 attach your USB cable. The Unix command "dmesg" should print
1453 it has found a new device. The environment variable usbtty
1454 can be set to gserial or cdc_acm to enable your device to
1455 appear to a USB host as a Linux gserial device or a
1456 Common Device Class Abstract Control Model serial device.
1457 If you select usbtty = gserial you should be able to enumerate
1459 # modprobe usbserial vendor=0xVendorID product=0xProductID
1460 else if using cdc_acm, simply setting the environment
1461 variable usbtty to be cdc_acm should suffice. The following
1462 might be defined in YourBoardName.h
1465 Define this to build a UDC device
1468 Define this to have a tty type of device available to
1469 talk to the UDC device
1472 Define this to enable the high speed support for usb
1473 device and usbtty. If this feature is enabled, a routine
1474 int is_usbd_high_speed(void)
1475 also needs to be defined by the driver to dynamically poll
1476 whether the enumeration has succeded at high speed or full
1479 CONFIG_SYS_CONSOLE_IS_IN_ENV
1480 Define this if you want stdin, stdout &/or stderr to
1484 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1485 Derive USB clock from external clock "blah"
1486 - CONFIG_SYS_USB_EXTC_CLK 0x02
1488 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1489 Derive USB clock from brgclk
1490 - CONFIG_SYS_USB_BRG_CLK 0x04
1492 If you have a USB-IF assigned VendorID then you may wish to
1493 define your own vendor specific values either in BoardName.h
1494 or directly in usbd_vendor_info.h. If you don't define
1495 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1496 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1497 should pretend to be a Linux device to it's target host.
1499 CONFIG_USBD_MANUFACTURER
1500 Define this string as the name of your company for
1501 - CONFIG_USBD_MANUFACTURER "my company"
1503 CONFIG_USBD_PRODUCT_NAME
1504 Define this string as the name of your product
1505 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1507 CONFIG_USBD_VENDORID
1508 Define this as your assigned Vendor ID from the USB
1509 Implementors Forum. This *must* be a genuine Vendor ID
1510 to avoid polluting the USB namespace.
1511 - CONFIG_USBD_VENDORID 0xFFFF
1513 CONFIG_USBD_PRODUCTID
1514 Define this as the unique Product ID
1516 - CONFIG_USBD_PRODUCTID 0xFFFF
1518 - ULPI Layer Support:
1519 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1520 the generic ULPI layer. The generic layer accesses the ULPI PHY
1521 via the platform viewport, so you need both the genric layer and
1522 the viewport enabled. Currently only Chipidea/ARC based
1523 viewport is supported.
1524 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1525 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1526 If your ULPI phy needs a different reference clock than the
1527 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1528 the appropriate value in Hz.
1531 The MMC controller on the Intel PXA is supported. To
1532 enable this define CONFIG_MMC. The MMC can be
1533 accessed from the boot prompt by mapping the device
1534 to physical memory similar to flash. Command line is
1535 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1536 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1539 Support for Renesas on-chip MMCIF controller
1541 CONFIG_SH_MMCIF_ADDR
1542 Define the base address of MMCIF registers
1545 Define the clock frequency for MMCIF
1548 Enable the generic MMC driver
1550 CONFIG_SUPPORT_EMMC_BOOT
1551 Enable some additional features of the eMMC boot partitions.
1553 CONFIG_SUPPORT_EMMC_RPMB
1554 Enable the commands for reading, writing and programming the
1555 key for the Replay Protection Memory Block partition in eMMC.
1557 - USB Device Firmware Update (DFU) class support:
1558 CONFIG_USB_FUNCTION_DFU
1559 This enables the USB portion of the DFU USB class
1562 This enables the command "dfu" which is used to have
1563 U-Boot create a DFU class device via USB. This command
1564 requires that the "dfu_alt_info" environment variable be
1565 set and define the alt settings to expose to the host.
1568 This enables support for exposing (e)MMC devices via DFU.
1571 This enables support for exposing NAND devices via DFU.
1574 This enables support for exposing RAM via DFU.
1575 Note: DFU spec refer to non-volatile memory usage, but
1576 allow usages beyond the scope of spec - here RAM usage,
1577 one that would help mostly the developer.
1579 CONFIG_SYS_DFU_DATA_BUF_SIZE
1580 Dfu transfer uses a buffer before writing data to the
1581 raw storage device. Make the size (in bytes) of this buffer
1582 configurable. The size of this buffer is also configurable
1583 through the "dfu_bufsiz" environment variable.
1585 CONFIG_SYS_DFU_MAX_FILE_SIZE
1586 When updating files rather than the raw storage device,
1587 we use a static buffer to copy the file into and then write
1588 the buffer once we've been given the whole file. Define
1589 this to the maximum filesize (in bytes) for the buffer.
1590 Default is 4 MiB if undefined.
1592 DFU_DEFAULT_POLL_TIMEOUT
1593 Poll timeout [ms], is the timeout a device can send to the
1594 host. The host must wait for this timeout before sending
1595 a subsequent DFU_GET_STATUS request to the device.
1597 DFU_MANIFEST_POLL_TIMEOUT
1598 Poll timeout [ms], which the device sends to the host when
1599 entering dfuMANIFEST state. Host waits this timeout, before
1600 sending again an USB request to the device.
1602 - USB Device Android Fastboot support:
1603 CONFIG_USB_FUNCTION_FASTBOOT
1604 This enables the USB part of the fastboot gadget
1607 This enables the command "fastboot" which enables the Android
1608 fastboot mode for the platform's USB device. Fastboot is a USB
1609 protocol for downloading images, flashing and device control
1610 used on Android devices.
1611 See doc/README.android-fastboot for more information.
1613 CONFIG_ANDROID_BOOT_IMAGE
1614 This enables support for booting images which use the Android
1615 image format header.
1617 CONFIG_FASTBOOT_BUF_ADDR
1618 The fastboot protocol requires a large memory buffer for
1619 downloads. Define this to the starting RAM address to use for
1622 CONFIG_FASTBOOT_BUF_SIZE
1623 The fastboot protocol requires a large memory buffer for
1624 downloads. This buffer should be as large as possible for a
1625 platform. Define this to the size available RAM for fastboot.
1627 CONFIG_FASTBOOT_FLASH
1628 The fastboot protocol includes a "flash" command for writing
1629 the downloaded image to a non-volatile storage device. Define
1630 this to enable the "fastboot flash" command.
1632 CONFIG_FASTBOOT_FLASH_MMC_DEV
1633 The fastboot "flash" command requires additional information
1634 regarding the non-volatile storage device. Define this to
1635 the eMMC device that fastboot should use to store the image.
1637 CONFIG_FASTBOOT_GPT_NAME
1638 The fastboot "flash" command supports writing the downloaded
1639 image to the Protective MBR and the Primary GUID Partition
1640 Table. (Additionally, this downloaded image is post-processed
1641 to generate and write the Backup GUID Partition Table.)
1642 This occurs when the specified "partition name" on the
1643 "fastboot flash" command line matches this value.
1644 The default is "gpt" if undefined.
1646 CONFIG_FASTBOOT_MBR_NAME
1647 The fastboot "flash" command supports writing the downloaded
1649 This occurs when the "partition name" specified on the
1650 "fastboot flash" command line matches this value.
1651 If not defined the default value "mbr" is used.
1653 - Journaling Flash filesystem support:
1655 Define these for a default partition on a NAND device
1657 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1658 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1659 Define these for a default partition on a NOR device
1661 - FAT(File Allocation Table) filesystem write function support:
1664 Define this to enable support for saving memory data as a
1665 file in FAT formatted partition.
1667 This will also enable the command "fatwrite" enabling the
1668 user to write files to FAT.
1670 CBFS (Coreboot Filesystem) support
1673 Define this to enable support for reading from a Coreboot
1674 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1677 - FAT(File Allocation Table) filesystem cluster size:
1678 CONFIG_FS_FAT_MAX_CLUSTSIZE
1680 Define the max cluster size for fat operations else
1681 a default value of 65536 will be defined.
1684 See Kconfig help for available keyboard drivers.
1688 Define this to enable a custom keyboard support.
1689 This simply calls drv_keyboard_init() which must be
1690 defined in your board-specific files. This option is deprecated
1691 and is only used by novena. For new boards, use driver model
1697 Define this to enable video support (for output to
1700 CONFIG_VIDEO_CT69000
1702 Enable Chips & Technologies 69000 Video chip
1704 CONFIG_VIDEO_SMI_LYNXEM
1705 Enable Silicon Motion SMI 712/710/810 Video chip. The
1706 video output is selected via environment 'videoout'
1707 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1710 For the CT69000 and SMI_LYNXEM drivers, videomode is
1711 selected via environment 'videomode'. Two different ways
1713 - "videomode=num" 'num' is a standard LiLo mode numbers.
1714 Following standard modes are supported (* is default):
1716 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1717 -------------+---------------------------------------------
1718 8 bits | 0x301* 0x303 0x305 0x161 0x307
1719 15 bits | 0x310 0x313 0x316 0x162 0x319
1720 16 bits | 0x311 0x314 0x317 0x163 0x31A
1721 24 bits | 0x312 0x315 0x318 ? 0x31B
1722 -------------+---------------------------------------------
1723 (i.e. setenv videomode 317; saveenv; reset;)
1725 - "videomode=bootargs" all the video parameters are parsed
1726 from the bootargs. (See drivers/video/videomodes.c)
1729 CONFIG_VIDEO_SED13806
1730 Enable Epson SED13806 driver. This driver supports 8bpp
1731 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1732 or CONFIG_VIDEO_SED13806_16BPP
1735 Enable the Freescale DIU video driver. Reference boards for
1736 SOCs that have a DIU should define this macro to enable DIU
1737 support, and should also define these other macros:
1743 CONFIG_VIDEO_SW_CURSOR
1744 CONFIG_VGA_AS_SINGLE_DEVICE
1746 CONFIG_VIDEO_BMP_LOGO
1748 The DIU driver will look for the 'video-mode' environment
1749 variable, and if defined, enable the DIU as a console during
1750 boot. See the documentation file doc/README.video for a
1751 description of this variable.
1753 - LCD Support: CONFIG_LCD
1755 Define this to enable LCD support (for output to LCD
1756 display); also select one of the supported displays
1757 by defining one of these:
1761 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1763 CONFIG_NEC_NL6448AC33:
1765 NEC NL6448AC33-18. Active, color, single scan.
1767 CONFIG_NEC_NL6448BC20
1769 NEC NL6448BC20-08. 6.5", 640x480.
1770 Active, color, single scan.
1772 CONFIG_NEC_NL6448BC33_54
1774 NEC NL6448BC33-54. 10.4", 640x480.
1775 Active, color, single scan.
1779 Sharp 320x240. Active, color, single scan.
1780 It isn't 16x9, and I am not sure what it is.
1782 CONFIG_SHARP_LQ64D341
1784 Sharp LQ64D341 display, 640x480.
1785 Active, color, single scan.
1789 HLD1045 display, 640x480.
1790 Active, color, single scan.
1794 Optrex CBL50840-2 NF-FW 99 22 M5
1796 Hitachi LMG6912RPFC-00T
1800 320x240. Black & white.
1802 Normally display is black on white background; define
1803 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1805 CONFIG_LCD_ALIGNMENT
1807 Normally the LCD is page-aligned (typically 4KB). If this is
1808 defined then the LCD will be aligned to this value instead.
1809 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1810 here, since it is cheaper to change data cache settings on
1811 a per-section basis.
1813 CONFIG_CONSOLE_SCROLL_LINES
1815 When the console need to be scrolled, this is the number of
1816 lines to scroll by. It defaults to 1. Increasing this makes
1817 the console jump but can help speed up operation when scrolling
1822 Sometimes, for example if the display is mounted in portrait
1823 mode or even if it's mounted landscape but rotated by 180degree,
1824 we need to rotate our content of the display relative to the
1825 framebuffer, so that user can read the messages which are
1827 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1828 initialized with a given rotation from "vl_rot" out of
1829 "vidinfo_t" which is provided by the board specific code.
1830 The value for vl_rot is coded as following (matching to
1831 fbcon=rotate:<n> linux-kernel commandline):
1832 0 = no rotation respectively 0 degree
1833 1 = 90 degree rotation
1834 2 = 180 degree rotation
1835 3 = 270 degree rotation
1837 If CONFIG_LCD_ROTATION is not defined, the console will be
1838 initialized with 0degree rotation.
1842 Support drawing of RLE8-compressed bitmaps on the LCD.
1846 Enables an 'i2c edid' command which can read EDID
1847 information over I2C from an attached LCD display.
1849 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1851 If this option is set, the environment is checked for
1852 a variable "splashimage". If found, the usual display
1853 of logo, copyright and system information on the LCD
1854 is suppressed and the BMP image at the address
1855 specified in "splashimage" is loaded instead. The
1856 console is redirected to the "nulldev", too. This
1857 allows for a "silent" boot where a splash screen is
1858 loaded very quickly after power-on.
1860 CONFIG_SPLASHIMAGE_GUARD
1862 If this option is set, then U-Boot will prevent the environment
1863 variable "splashimage" from being set to a problematic address
1864 (see doc/README.displaying-bmps).
1865 This option is useful for targets where, due to alignment
1866 restrictions, an improperly aligned BMP image will cause a data
1867 abort. If you think you will not have problems with unaligned
1868 accesses (for example because your toolchain prevents them)
1869 there is no need to set this option.
1871 CONFIG_SPLASH_SCREEN_ALIGN
1873 If this option is set the splash image can be freely positioned
1874 on the screen. Environment variable "splashpos" specifies the
1875 position as "x,y". If a positive number is given it is used as
1876 number of pixel from left/top. If a negative number is given it
1877 is used as number of pixel from right/bottom. You can also
1878 specify 'm' for centering the image.
1881 setenv splashpos m,m
1882 => image at center of screen
1884 setenv splashpos 30,20
1885 => image at x = 30 and y = 20
1887 setenv splashpos -10,m
1888 => vertically centered image
1889 at x = dspWidth - bmpWidth - 9
1891 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1893 If this option is set, additionally to standard BMP
1894 images, gzipped BMP images can be displayed via the
1895 splashscreen support or the bmp command.
1897 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1899 If this option is set, 8-bit RLE compressed BMP images
1900 can be displayed via the splashscreen support or the
1903 - Do compressing for memory range:
1906 If this option is set, it would use zlib deflate method
1907 to compress the specified memory at its best effort.
1909 - Compression support:
1912 Enabled by default to support gzip compressed images.
1916 If this option is set, support for bzip2 compressed
1917 images is included. If not, only uncompressed and gzip
1918 compressed images are supported.
1920 NOTE: the bzip2 algorithm requires a lot of RAM, so
1921 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1926 If this option is set, support for lzma compressed
1929 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1930 requires an amount of dynamic memory that is given by the
1933 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1935 Where lc and lp stand for, respectively, Literal context bits
1936 and Literal pos bits.
1938 This value is upper-bounded by 14MB in the worst case. Anyway,
1939 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1940 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1941 a very small buffer.
1943 Use the lzmainfo tool to determinate the lc and lp values and
1944 then calculate the amount of needed dynamic memory (ensuring
1945 the appropriate CONFIG_SYS_MALLOC_LEN value).
1949 If this option is set, support for LZO compressed images
1955 The address of PHY on MII bus.
1957 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1959 The clock frequency of the MII bus
1963 If this option is set, support for speed/duplex
1964 detection of gigabit PHY is included.
1966 CONFIG_PHY_RESET_DELAY
1968 Some PHY like Intel LXT971A need extra delay after
1969 reset before any MII register access is possible.
1970 For such PHY, set this option to the usec delay
1971 required. (minimum 300usec for LXT971A)
1973 CONFIG_PHY_CMD_DELAY (ppc4xx)
1975 Some PHY like Intel LXT971A need extra delay after
1976 command issued before MII status register can be read
1981 Define a default value for the IP address to use for
1982 the default Ethernet interface, in case this is not
1983 determined through e.g. bootp.
1984 (Environment variable "ipaddr")
1986 - Server IP address:
1989 Defines a default value for the IP address of a TFTP
1990 server to contact when using the "tftboot" command.
1991 (Environment variable "serverip")
1993 CONFIG_KEEP_SERVERADDR
1995 Keeps the server's MAC address, in the env 'serveraddr'
1996 for passing to bootargs (like Linux's netconsole option)
1998 - Gateway IP address:
2001 Defines a default value for the IP address of the
2002 default router where packets to other networks are
2004 (Environment variable "gatewayip")
2009 Defines a default value for the subnet mask (or
2010 routing prefix) which is used to determine if an IP
2011 address belongs to the local subnet or needs to be
2012 forwarded through a router.
2013 (Environment variable "netmask")
2015 - Multicast TFTP Mode:
2018 Defines whether you want to support multicast TFTP as per
2019 rfc-2090; for example to work with atftp. Lets lots of targets
2020 tftp down the same boot image concurrently. Note: the Ethernet
2021 driver in use must provide a function: mcast() to join/leave a
2024 - BOOTP Recovery Mode:
2025 CONFIG_BOOTP_RANDOM_DELAY
2027 If you have many targets in a network that try to
2028 boot using BOOTP, you may want to avoid that all
2029 systems send out BOOTP requests at precisely the same
2030 moment (which would happen for instance at recovery
2031 from a power failure, when all systems will try to
2032 boot, thus flooding the BOOTP server. Defining
2033 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2034 inserted before sending out BOOTP requests. The
2035 following delays are inserted then:
2037 1st BOOTP request: delay 0 ... 1 sec
2038 2nd BOOTP request: delay 0 ... 2 sec
2039 3rd BOOTP request: delay 0 ... 4 sec
2041 BOOTP requests: delay 0 ... 8 sec
2043 CONFIG_BOOTP_ID_CACHE_SIZE
2045 BOOTP packets are uniquely identified using a 32-bit ID. The
2046 server will copy the ID from client requests to responses and
2047 U-Boot will use this to determine if it is the destination of
2048 an incoming response. Some servers will check that addresses
2049 aren't in use before handing them out (usually using an ARP
2050 ping) and therefore take up to a few hundred milliseconds to
2051 respond. Network congestion may also influence the time it
2052 takes for a response to make it back to the client. If that
2053 time is too long, U-Boot will retransmit requests. In order
2054 to allow earlier responses to still be accepted after these
2055 retransmissions, U-Boot's BOOTP client keeps a small cache of
2056 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2057 cache. The default is to keep IDs for up to four outstanding
2058 requests. Increasing this will allow U-Boot to accept offers
2059 from a BOOTP client in networks with unusually high latency.
2061 - DHCP Advanced Options:
2062 You can fine tune the DHCP functionality by defining
2063 CONFIG_BOOTP_* symbols:
2065 CONFIG_BOOTP_SUBNETMASK
2066 CONFIG_BOOTP_GATEWAY
2067 CONFIG_BOOTP_HOSTNAME
2068 CONFIG_BOOTP_NISDOMAIN
2069 CONFIG_BOOTP_BOOTPATH
2070 CONFIG_BOOTP_BOOTFILESIZE
2073 CONFIG_BOOTP_SEND_HOSTNAME
2074 CONFIG_BOOTP_NTPSERVER
2075 CONFIG_BOOTP_TIMEOFFSET
2076 CONFIG_BOOTP_VENDOREX
2077 CONFIG_BOOTP_MAY_FAIL
2079 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2080 environment variable, not the BOOTP server.
2082 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2083 after the configured retry count, the call will fail
2084 instead of starting over. This can be used to fail over
2085 to Link-local IP address configuration if the DHCP server
2088 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2089 serverip from a DHCP server, it is possible that more
2090 than one DNS serverip is offered to the client.
2091 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2092 serverip will be stored in the additional environment
2093 variable "dnsip2". The first DNS serverip is always
2094 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2097 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2098 to do a dynamic update of a DNS server. To do this, they
2099 need the hostname of the DHCP requester.
2100 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2101 of the "hostname" environment variable is passed as
2102 option 12 to the DHCP server.
2104 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2106 A 32bit value in microseconds for a delay between
2107 receiving a "DHCP Offer" and sending the "DHCP Request".
2108 This fixes a problem with certain DHCP servers that don't
2109 respond 100% of the time to a "DHCP request". E.g. On an
2110 AT91RM9200 processor running at 180MHz, this delay needed
2111 to be *at least* 15,000 usec before a Windows Server 2003
2112 DHCP server would reply 100% of the time. I recommend at
2113 least 50,000 usec to be safe. The alternative is to hope
2114 that one of the retries will be successful but note that
2115 the DHCP timeout and retry process takes a longer than
2118 - Link-local IP address negotiation:
2119 Negotiate with other link-local clients on the local network
2120 for an address that doesn't require explicit configuration.
2121 This is especially useful if a DHCP server cannot be guaranteed
2122 to exist in all environments that the device must operate.
2124 See doc/README.link-local for more information.
2127 CONFIG_CDP_DEVICE_ID
2129 The device id used in CDP trigger frames.
2131 CONFIG_CDP_DEVICE_ID_PREFIX
2133 A two character string which is prefixed to the MAC address
2138 A printf format string which contains the ascii name of
2139 the port. Normally is set to "eth%d" which sets
2140 eth0 for the first Ethernet, eth1 for the second etc.
2142 CONFIG_CDP_CAPABILITIES
2144 A 32bit integer which indicates the device capabilities;
2145 0x00000010 for a normal host which does not forwards.
2149 An ascii string containing the version of the software.
2153 An ascii string containing the name of the platform.
2157 A 32bit integer sent on the trigger.
2159 CONFIG_CDP_POWER_CONSUMPTION
2161 A 16bit integer containing the power consumption of the
2162 device in .1 of milliwatts.
2164 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2166 A byte containing the id of the VLAN.
2168 - Status LED: CONFIG_STATUS_LED
2170 Several configurations allow to display the current
2171 status using a LED. For instance, the LED will blink
2172 fast while running U-Boot code, stop blinking as
2173 soon as a reply to a BOOTP request was received, and
2174 start blinking slow once the Linux kernel is running
2175 (supported by a status LED driver in the Linux
2176 kernel). Defining CONFIG_STATUS_LED enables this
2182 The status LED can be connected to a GPIO pin.
2183 In such cases, the gpio_led driver can be used as a
2184 status LED backend implementation. Define CONFIG_GPIO_LED
2185 to include the gpio_led driver in the U-Boot binary.
2187 CONFIG_GPIO_LED_INVERTED_TABLE
2188 Some GPIO connected LEDs may have inverted polarity in which
2189 case the GPIO high value corresponds to LED off state and
2190 GPIO low value corresponds to LED on state.
2191 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2192 with a list of GPIO LEDs that have inverted polarity.
2194 - CAN Support: CONFIG_CAN_DRIVER
2196 Defining CONFIG_CAN_DRIVER enables CAN driver support
2197 on those systems that support this (optional)
2198 feature, like the TQM8xxL modules.
2200 - I2C Support: CONFIG_SYS_I2C
2202 This enable the NEW i2c subsystem, and will allow you to use
2203 i2c commands at the u-boot command line (as long as you set
2204 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2205 based realtime clock chips or other i2c devices. See
2206 common/cmd_i2c.c for a description of the command line
2209 ported i2c driver to the new framework:
2210 - drivers/i2c/soft_i2c.c:
2211 - activate first bus with CONFIG_SYS_I2C_SOFT define
2212 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2213 for defining speed and slave address
2214 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2215 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2216 for defining speed and slave address
2217 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2218 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2219 for defining speed and slave address
2220 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2221 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2222 for defining speed and slave address
2224 - drivers/i2c/fsl_i2c.c:
2225 - activate i2c driver with CONFIG_SYS_I2C_FSL
2226 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2227 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2228 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2230 - If your board supports a second fsl i2c bus, define
2231 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2232 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2233 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2236 - drivers/i2c/tegra_i2c.c:
2237 - activate this driver with CONFIG_SYS_I2C_TEGRA
2238 - This driver adds 4 i2c buses with a fix speed from
2239 100000 and the slave addr 0!
2241 - drivers/i2c/ppc4xx_i2c.c
2242 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2243 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2244 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2246 - drivers/i2c/i2c_mxc.c
2247 - activate this driver with CONFIG_SYS_I2C_MXC
2248 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
2249 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
2250 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
2251 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
2252 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2253 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2254 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2255 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2256 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2257 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2258 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
2259 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
2260 If those defines are not set, default value is 100000
2261 for speed, and 0 for slave.
2263 - drivers/i2c/rcar_i2c.c:
2264 - activate this driver with CONFIG_SYS_I2C_RCAR
2265 - This driver adds 4 i2c buses
2267 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2268 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2269 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2270 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2271 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2272 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2273 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2274 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2275 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2277 - drivers/i2c/sh_i2c.c:
2278 - activate this driver with CONFIG_SYS_I2C_SH
2279 - This driver adds from 2 to 5 i2c buses
2281 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2282 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2283 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2284 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2285 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2286 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2287 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2288 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2289 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2290 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2291 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2292 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2293 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
2295 - drivers/i2c/omap24xx_i2c.c
2296 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2297 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2298 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2299 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2300 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2301 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2302 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2303 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2304 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2305 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2306 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2308 - drivers/i2c/zynq_i2c.c
2309 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2310 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2311 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2313 - drivers/i2c/s3c24x0_i2c.c:
2314 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2315 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2316 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2317 with a fix speed from 100000 and the slave addr 0!
2319 - drivers/i2c/ihs_i2c.c
2320 - activate this driver with CONFIG_SYS_I2C_IHS
2321 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2322 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2323 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2324 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2325 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2326 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2327 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2328 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2329 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2330 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2331 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2332 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2333 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
2334 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
2335 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
2336 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
2337 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
2338 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
2339 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
2340 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
2341 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
2345 CONFIG_SYS_NUM_I2C_BUSES
2346 Hold the number of i2c buses you want to use. If you
2347 don't use/have i2c muxes on your i2c bus, this
2348 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2351 CONFIG_SYS_I2C_DIRECT_BUS
2352 define this, if you don't use i2c muxes on your hardware.
2353 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2356 CONFIG_SYS_I2C_MAX_HOPS
2357 define how many muxes are maximal consecutively connected
2358 on one i2c bus. If you not use i2c muxes, omit this
2361 CONFIG_SYS_I2C_BUSES
2362 hold a list of buses you want to use, only used if
2363 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2364 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2365 CONFIG_SYS_NUM_I2C_BUSES = 9:
2367 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2368 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2369 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2370 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2371 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2372 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2373 {1, {I2C_NULL_HOP}}, \
2374 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2375 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2379 bus 0 on adapter 0 without a mux
2380 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2381 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2382 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2383 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2384 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2385 bus 6 on adapter 1 without a mux
2386 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2387 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2389 If you do not have i2c muxes on your board, omit this define.
2391 - Legacy I2C Support: CONFIG_HARD_I2C
2393 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2394 provides the following compelling advantages:
2396 - more than one i2c adapter is usable
2397 - approved multibus support
2398 - better i2c mux support
2400 ** Please consider updating your I2C driver now. **
2402 These enable legacy I2C serial bus commands. Defining
2403 CONFIG_HARD_I2C will include the appropriate I2C driver
2404 for the selected CPU.
2406 This will allow you to use i2c commands at the u-boot
2407 command line (as long as you set CONFIG_CMD_I2C in
2408 CONFIG_COMMANDS) and communicate with i2c based realtime
2409 clock chips. See common/cmd_i2c.c for a description of the
2410 command line interface.
2412 CONFIG_HARD_I2C selects a hardware I2C controller.
2414 There are several other quantities that must also be
2415 defined when you define CONFIG_HARD_I2C.
2417 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2418 to be the frequency (in Hz) at which you wish your i2c bus
2419 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2420 the CPU's i2c node address).
2422 Now, the u-boot i2c code for the mpc8xx
2423 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2424 and so its address should therefore be cleared to 0 (See,
2425 eg, MPC823e User's Manual p.16-473). So, set
2426 CONFIG_SYS_I2C_SLAVE to 0.
2428 CONFIG_SYS_I2C_INIT_MPC5XXX
2430 When a board is reset during an i2c bus transfer
2431 chips might think that the current transfer is still
2432 in progress. Reset the slave devices by sending start
2433 commands until the slave device responds.
2435 That's all that's required for CONFIG_HARD_I2C.
2437 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2438 then the following macros need to be defined (examples are
2439 from include/configs/lwmon.h):
2443 (Optional). Any commands necessary to enable the I2C
2444 controller or configure ports.
2446 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2450 (Only for MPC8260 CPU). The I/O port to use (the code
2451 assumes both bits are on the same port). Valid values
2452 are 0..3 for ports A..D.
2456 The code necessary to make the I2C data line active
2457 (driven). If the data line is open collector, this
2460 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2464 The code necessary to make the I2C data line tri-stated
2465 (inactive). If the data line is open collector, this
2468 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2472 Code that returns true if the I2C data line is high,
2475 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2479 If <bit> is true, sets the I2C data line high. If it
2480 is false, it clears it (low).
2482 eg: #define I2C_SDA(bit) \
2483 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2484 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2488 If <bit> is true, sets the I2C clock line high. If it
2489 is false, it clears it (low).
2491 eg: #define I2C_SCL(bit) \
2492 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2493 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2497 This delay is invoked four times per clock cycle so this
2498 controls the rate of data transfer. The data rate thus
2499 is 1 / (I2C_DELAY * 4). Often defined to be something
2502 #define I2C_DELAY udelay(2)
2504 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2506 If your arch supports the generic GPIO framework (asm/gpio.h),
2507 then you may alternatively define the two GPIOs that are to be
2508 used as SCL / SDA. Any of the previous I2C_xxx macros will
2509 have GPIO-based defaults assigned to them as appropriate.
2511 You should define these to the GPIO value as given directly to
2512 the generic GPIO functions.
2514 CONFIG_SYS_I2C_INIT_BOARD
2516 When a board is reset during an i2c bus transfer
2517 chips might think that the current transfer is still
2518 in progress. On some boards it is possible to access
2519 the i2c SCLK line directly, either by using the
2520 processor pin as a GPIO or by having a second pin
2521 connected to the bus. If this option is defined a
2522 custom i2c_init_board() routine in boards/xxx/board.c
2523 is run early in the boot sequence.
2525 CONFIG_SYS_I2C_BOARD_LATE_INIT
2527 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2528 defined a custom i2c_board_late_init() routine in
2529 boards/xxx/board.c is run AFTER the operations in i2c_init()
2530 is completed. This callpoint can be used to unreset i2c bus
2531 using CPU i2c controller register accesses for CPUs whose i2c
2532 controller provide such a method. It is called at the end of
2533 i2c_init() to allow i2c_init operations to setup the i2c bus
2534 controller on the CPU (e.g. setting bus speed & slave address).
2536 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2538 This option enables configuration of bi_iic_fast[] flags
2539 in u-boot bd_info structure based on u-boot environment
2540 variable "i2cfast". (see also i2cfast)
2542 CONFIG_I2C_MULTI_BUS
2544 This option allows the use of multiple I2C buses, each of which
2545 must have a controller. At any point in time, only one bus is
2546 active. To switch to a different bus, use the 'i2c dev' command.
2547 Note that bus numbering is zero-based.
2549 CONFIG_SYS_I2C_NOPROBES
2551 This option specifies a list of I2C devices that will be skipped
2552 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2553 is set, specify a list of bus-device pairs. Otherwise, specify
2554 a 1D array of device addresses
2557 #undef CONFIG_I2C_MULTI_BUS
2558 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2560 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2562 #define CONFIG_I2C_MULTI_BUS
2563 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2565 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2567 CONFIG_SYS_SPD_BUS_NUM
2569 If defined, then this indicates the I2C bus number for DDR SPD.
2570 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2572 CONFIG_SYS_RTC_BUS_NUM
2574 If defined, then this indicates the I2C bus number for the RTC.
2575 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2577 CONFIG_SYS_DTT_BUS_NUM
2579 If defined, then this indicates the I2C bus number for the DTT.
2580 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2582 CONFIG_SYS_I2C_DTT_ADDR:
2584 If defined, specifies the I2C address of the DTT device.
2585 If not defined, then U-Boot uses predefined value for
2586 specified DTT device.
2588 CONFIG_SOFT_I2C_READ_REPEATED_START
2590 defining this will force the i2c_read() function in
2591 the soft_i2c driver to perform an I2C repeated start
2592 between writing the address pointer and reading the
2593 data. If this define is omitted the default behaviour
2594 of doing a stop-start sequence will be used. Most I2C
2595 devices can use either method, but some require one or
2598 - SPI Support: CONFIG_SPI
2600 Enables SPI driver (so far only tested with
2601 SPI EEPROM, also an instance works with Crystal A/D and
2602 D/As on the SACSng board)
2606 Enables the driver for SPI controller on SuperH. Currently
2607 only SH7757 is supported.
2611 Enables a software (bit-bang) SPI driver rather than
2612 using hardware support. This is a general purpose
2613 driver that only requires three general I/O port pins
2614 (two outputs, one input) to function. If this is
2615 defined, the board configuration must define several
2616 SPI configuration items (port pins to use, etc). For
2617 an example, see include/configs/sacsng.h.
2621 Enables a hardware SPI driver for general-purpose reads
2622 and writes. As with CONFIG_SOFT_SPI, the board configuration
2623 must define a list of chip-select function pointers.
2624 Currently supported on some MPC8xxx processors. For an
2625 example, see include/configs/mpc8349emds.h.
2629 Enables the driver for the SPI controllers on i.MX and MXC
2630 SoCs. Currently i.MX31/35/51 are supported.
2632 CONFIG_SYS_SPI_MXC_WAIT
2633 Timeout for waiting until spi transfer completed.
2634 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2636 - FPGA Support: CONFIG_FPGA
2638 Enables FPGA subsystem.
2640 CONFIG_FPGA_<vendor>
2642 Enables support for specific chip vendors.
2645 CONFIG_FPGA_<family>
2647 Enables support for FPGA family.
2648 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2652 Specify the number of FPGA devices to support.
2654 CONFIG_CMD_FPGA_LOADMK
2656 Enable support for fpga loadmk command
2658 CONFIG_CMD_FPGA_LOADP
2660 Enable support for fpga loadp command - load partial bitstream
2662 CONFIG_CMD_FPGA_LOADBP
2664 Enable support for fpga loadbp command - load partial bitstream
2667 CONFIG_SYS_FPGA_PROG_FEEDBACK
2669 Enable printing of hash marks during FPGA configuration.
2671 CONFIG_SYS_FPGA_CHECK_BUSY
2673 Enable checks on FPGA configuration interface busy
2674 status by the configuration function. This option
2675 will require a board or device specific function to
2680 If defined, a function that provides delays in the FPGA
2681 configuration driver.
2683 CONFIG_SYS_FPGA_CHECK_CTRLC
2684 Allow Control-C to interrupt FPGA configuration
2686 CONFIG_SYS_FPGA_CHECK_ERROR
2688 Check for configuration errors during FPGA bitfile
2689 loading. For example, abort during Virtex II
2690 configuration if the INIT_B line goes low (which
2691 indicated a CRC error).
2693 CONFIG_SYS_FPGA_WAIT_INIT
2695 Maximum time to wait for the INIT_B line to de-assert
2696 after PROB_B has been de-asserted during a Virtex II
2697 FPGA configuration sequence. The default time is 500
2700 CONFIG_SYS_FPGA_WAIT_BUSY
2702 Maximum time to wait for BUSY to de-assert during
2703 Virtex II FPGA configuration. The default is 5 ms.
2705 CONFIG_SYS_FPGA_WAIT_CONFIG
2707 Time to wait after FPGA configuration. The default is
2710 - Configuration Management:
2713 Some SoCs need special image types (e.g. U-Boot binary
2714 with a special header) as build targets. By defining
2715 CONFIG_BUILD_TARGET in the SoC / board header, this
2716 special image will be automatically built upon calling
2721 If defined, this string will be added to the U-Boot
2722 version information (U_BOOT_VERSION)
2724 - Vendor Parameter Protection:
2726 U-Boot considers the values of the environment
2727 variables "serial#" (Board Serial Number) and
2728 "ethaddr" (Ethernet Address) to be parameters that
2729 are set once by the board vendor / manufacturer, and
2730 protects these variables from casual modification by
2731 the user. Once set, these variables are read-only,
2732 and write or delete attempts are rejected. You can
2733 change this behaviour:
2735 If CONFIG_ENV_OVERWRITE is #defined in your config
2736 file, the write protection for vendor parameters is
2737 completely disabled. Anybody can change or delete
2740 Alternatively, if you define _both_ an ethaddr in the
2741 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2742 Ethernet address is installed in the environment,
2743 which can be changed exactly ONCE by the user. [The
2744 serial# is unaffected by this, i. e. it remains
2747 The same can be accomplished in a more flexible way
2748 for any variable by configuring the type of access
2749 to allow for those variables in the ".flags" variable
2750 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2755 Define this variable to enable the reservation of
2756 "protected RAM", i. e. RAM which is not overwritten
2757 by U-Boot. Define CONFIG_PRAM to hold the number of
2758 kB you want to reserve for pRAM. You can overwrite
2759 this default value by defining an environment
2760 variable "pram" to the number of kB you want to
2761 reserve. Note that the board info structure will
2762 still show the full amount of RAM. If pRAM is
2763 reserved, a new environment variable "mem" will
2764 automatically be defined to hold the amount of
2765 remaining RAM in a form that can be passed as boot
2766 argument to Linux, for instance like that:
2768 setenv bootargs ... mem=\${mem}
2771 This way you can tell Linux not to use this memory,
2772 either, which results in a memory region that will
2773 not be affected by reboots.
2775 *WARNING* If your board configuration uses automatic
2776 detection of the RAM size, you must make sure that
2777 this memory test is non-destructive. So far, the
2778 following board configurations are known to be
2781 IVMS8, IVML24, SPD8xx, TQM8xxL,
2782 HERMES, IP860, RPXlite, LWMON,
2785 - Access to physical memory region (> 4GB)
2786 Some basic support is provided for operations on memory not
2787 normally accessible to U-Boot - e.g. some architectures
2788 support access to more than 4GB of memory on 32-bit
2789 machines using physical address extension or similar.
2790 Define CONFIG_PHYSMEM to access this basic support, which
2791 currently only supports clearing the memory.
2796 Define this variable to stop the system in case of a
2797 fatal error, so that you have to reset it manually.
2798 This is probably NOT a good idea for an embedded
2799 system where you want the system to reboot
2800 automatically as fast as possible, but it may be
2801 useful during development since you can try to debug
2802 the conditions that lead to the situation.
2804 CONFIG_NET_RETRY_COUNT
2806 This variable defines the number of retries for
2807 network operations like ARP, RARP, TFTP, or BOOTP
2808 before giving up the operation. If not defined, a
2809 default value of 5 is used.
2813 Timeout waiting for an ARP reply in milliseconds.
2817 Timeout in milliseconds used in NFS protocol.
2818 If you encounter "ERROR: Cannot umount" in nfs command,
2819 try longer timeout such as
2820 #define CONFIG_NFS_TIMEOUT 10000UL
2822 - Command Interpreter:
2823 CONFIG_AUTO_COMPLETE
2825 Enable auto completion of commands using TAB.
2827 CONFIG_SYS_PROMPT_HUSH_PS2
2829 This defines the secondary prompt string, which is
2830 printed when the command interpreter needs more input
2831 to complete a command. Usually "> ".
2835 In the current implementation, the local variables
2836 space and global environment variables space are
2837 separated. Local variables are those you define by
2838 simply typing `name=value'. To access a local
2839 variable later on, you have write `$name' or
2840 `${name}'; to execute the contents of a variable
2841 directly type `$name' at the command prompt.
2843 Global environment variables are those you use
2844 setenv/printenv to work with. To run a command stored
2845 in such a variable, you need to use the run command,
2846 and you must not use the '$' sign to access them.
2848 To store commands and special characters in a
2849 variable, please use double quotation marks
2850 surrounding the whole text of the variable, instead
2851 of the backslashes before semicolons and special
2854 - Command Line Editing and History:
2855 CONFIG_CMDLINE_EDITING
2857 Enable editing and History functions for interactive
2858 command line input operations
2860 - Command Line PS1/PS2 support:
2861 CONFIG_CMDLINE_PS_SUPPORT
2863 Enable support for changing the command prompt string
2864 at run-time. Only static string is supported so far.
2865 The string is obtained from environment variables PS1
2868 - Default Environment:
2869 CONFIG_EXTRA_ENV_SETTINGS
2871 Define this to contain any number of null terminated
2872 strings (variable = value pairs) that will be part of
2873 the default environment compiled into the boot image.
2875 For example, place something like this in your
2876 board's config file:
2878 #define CONFIG_EXTRA_ENV_SETTINGS \
2882 Warning: This method is based on knowledge about the
2883 internal format how the environment is stored by the
2884 U-Boot code. This is NOT an official, exported
2885 interface! Although it is unlikely that this format
2886 will change soon, there is no guarantee either.
2887 You better know what you are doing here.
2889 Note: overly (ab)use of the default environment is
2890 discouraged. Make sure to check other ways to preset
2891 the environment like the "source" command or the
2894 CONFIG_ENV_VARS_UBOOT_CONFIG
2896 Define this in order to add variables describing the
2897 U-Boot build configuration to the default environment.
2898 These will be named arch, cpu, board, vendor, and soc.
2900 Enabling this option will cause the following to be defined:
2908 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2910 Define this in order to add variables describing certain
2911 run-time determined information about the hardware to the
2912 environment. These will be named board_name, board_rev.
2914 CONFIG_DELAY_ENVIRONMENT
2916 Normally the environment is loaded when the board is
2917 initialised so that it is available to U-Boot. This inhibits
2918 that so that the environment is not available until
2919 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2920 this is instead controlled by the value of
2921 /config/load-environment.
2923 - Parallel Flash support:
2926 Traditionally U-Boot was run on systems with parallel NOR
2927 flash. This option is used to disable support for parallel NOR
2928 flash. This option should be defined if the board does not have
2931 If this option is not defined one of the generic flash drivers
2932 (e.g. CONFIG_FLASH_CFI_DRIVER or CONFIG_ST_SMI) must be
2933 selected or the board must provide an implementation of the
2934 flash API (see include/flash.h).
2936 - DataFlash Support:
2937 CONFIG_HAS_DATAFLASH
2939 Defining this option enables DataFlash features and
2940 allows to read/write in Dataflash via the standard
2943 - Serial Flash support
2946 Defining this option enables SPI flash commands
2947 'sf probe/read/write/erase/update'.
2949 Usage requires an initial 'probe' to define the serial
2950 flash parameters, followed by read/write/erase/update
2953 The following defaults may be provided by the platform
2954 to handle the common case when only a single serial
2955 flash is present on the system.
2957 CONFIG_SF_DEFAULT_BUS Bus identifier
2958 CONFIG_SF_DEFAULT_CS Chip-select
2959 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2960 CONFIG_SF_DEFAULT_SPEED in Hz
2964 Define this option to include a destructive SPI flash
2967 CONFIG_SF_DUAL_FLASH Dual flash memories
2969 Define this option to use dual flash support where two flash
2970 memories can be connected with a given cs line.
2971 Currently Xilinx Zynq qspi supports these type of connections.
2973 - SystemACE Support:
2976 Adding this option adds support for Xilinx SystemACE
2977 chips attached via some sort of local bus. The address
2978 of the chip must also be defined in the
2979 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2981 #define CONFIG_SYSTEMACE
2982 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2984 When SystemACE support is added, the "ace" device type
2985 becomes available to the fat commands, i.e. fatls.
2987 - TFTP Fixed UDP Port:
2990 If this is defined, the environment variable tftpsrcp
2991 is used to supply the TFTP UDP source port value.
2992 If tftpsrcp isn't defined, the normal pseudo-random port
2993 number generator is used.
2995 Also, the environment variable tftpdstp is used to supply
2996 the TFTP UDP destination port value. If tftpdstp isn't
2997 defined, the normal port 69 is used.
2999 The purpose for tftpsrcp is to allow a TFTP server to
3000 blindly start the TFTP transfer using the pre-configured
3001 target IP address and UDP port. This has the effect of
3002 "punching through" the (Windows XP) firewall, allowing
3003 the remainder of the TFTP transfer to proceed normally.
3004 A better solution is to properly configure the firewall,
3005 but sometimes that is not allowed.
3010 This enables a generic 'hash' command which can produce
3011 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
3015 Enable the hash verify command (hash -v). This adds to code
3018 CONFIG_SHA1 - This option enables support of hashing using SHA1
3019 algorithm. The hash is calculated in software.
3020 CONFIG_SHA256 - This option enables support of hashing using
3021 SHA256 algorithm. The hash is calculated in software.
3022 CONFIG_SHA_HW_ACCEL - This option enables hardware acceleration
3023 for SHA1/SHA256 hashing.
3024 This affects the 'hash' command and also the
3025 hash_lookup_algo() function.
3026 CONFIG_SHA_PROG_HW_ACCEL - This option enables
3027 hardware-acceleration for SHA1/SHA256 progressive hashing.
3028 Data can be streamed in a block at a time and the hashing
3029 is performed in hardware.
3031 Note: There is also a sha1sum command, which should perhaps
3032 be deprecated in favour of 'hash sha1'.
3034 - Freescale i.MX specific commands:
3035 CONFIG_CMD_HDMIDETECT
3036 This enables 'hdmidet' command which returns true if an
3037 HDMI monitor is detected. This command is i.MX 6 specific.
3040 This enables the 'bmode' (bootmode) command for forcing
3041 a boot from specific media.
3043 This is useful for forcing the ROM's usb downloader to
3044 activate upon a watchdog reset which is nice when iterating
3045 on U-Boot. Using the reset button or running bmode normal
3046 will set it back to normal. This command currently
3047 supports i.MX53 and i.MX6.
3049 - bootcount support:
3050 CONFIG_BOOTCOUNT_LIMIT
3052 This enables the bootcounter support, see:
3053 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3056 enable special bootcounter support on at91sam9xe based boards.
3058 enable special bootcounter support on blackfin based boards.
3060 enable special bootcounter support on da850 based boards.
3061 CONFIG_BOOTCOUNT_RAM
3062 enable support for the bootcounter in RAM
3063 CONFIG_BOOTCOUNT_I2C
3064 enable support for the bootcounter on an i2c (like RTC) device.
3065 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3066 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3068 CONFIG_BOOTCOUNT_ALEN = address len
3070 - Show boot progress:
3071 CONFIG_SHOW_BOOT_PROGRESS
3073 Defining this option allows to add some board-
3074 specific code (calling a user-provided function
3075 "show_boot_progress(int)") that enables you to show
3076 the system's boot progress on some display (for
3077 example, some LED's) on your board. At the moment,
3078 the following checkpoints are implemented:
3081 Legacy uImage format:
3084 1 common/cmd_bootm.c before attempting to boot an image
3085 -1 common/cmd_bootm.c Image header has bad magic number
3086 2 common/cmd_bootm.c Image header has correct magic number
3087 -2 common/cmd_bootm.c Image header has bad checksum
3088 3 common/cmd_bootm.c Image header has correct checksum
3089 -3 common/cmd_bootm.c Image data has bad checksum
3090 4 common/cmd_bootm.c Image data has correct checksum
3091 -4 common/cmd_bootm.c Image is for unsupported architecture
3092 5 common/cmd_bootm.c Architecture check OK
3093 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3094 6 common/cmd_bootm.c Image Type check OK
3095 -6 common/cmd_bootm.c gunzip uncompression error
3096 -7 common/cmd_bootm.c Unimplemented compression type
3097 7 common/cmd_bootm.c Uncompression OK
3098 8 common/cmd_bootm.c No uncompress/copy overwrite error
3099 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3101 9 common/image.c Start initial ramdisk verification
3102 -10 common/image.c Ramdisk header has bad magic number
3103 -11 common/image.c Ramdisk header has bad checksum
3104 10 common/image.c Ramdisk header is OK
3105 -12 common/image.c Ramdisk data has bad checksum
3106 11 common/image.c Ramdisk data has correct checksum
3107 12 common/image.c Ramdisk verification complete, start loading
3108 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3109 13 common/image.c Start multifile image verification
3110 14 common/image.c No initial ramdisk, no multifile, continue.
3112 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3114 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3115 -31 post/post.c POST test failed, detected by post_output_backlog()
3116 -32 post/post.c POST test failed, detected by post_run_single()
3118 34 common/cmd_doc.c before loading a Image from a DOC device
3119 -35 common/cmd_doc.c Bad usage of "doc" command
3120 35 common/cmd_doc.c correct usage of "doc" command
3121 -36 common/cmd_doc.c No boot device
3122 36 common/cmd_doc.c correct boot device
3123 -37 common/cmd_doc.c Unknown Chip ID on boot device
3124 37 common/cmd_doc.c correct chip ID found, device available
3125 -38 common/cmd_doc.c Read Error on boot device
3126 38 common/cmd_doc.c reading Image header from DOC device OK
3127 -39 common/cmd_doc.c Image header has bad magic number
3128 39 common/cmd_doc.c Image header has correct magic number
3129 -40 common/cmd_doc.c Error reading Image from DOC device
3130 40 common/cmd_doc.c Image header has correct magic number
3131 41 common/cmd_ide.c before loading a Image from a IDE device
3132 -42 common/cmd_ide.c Bad usage of "ide" command
3133 42 common/cmd_ide.c correct usage of "ide" command
3134 -43 common/cmd_ide.c No boot device
3135 43 common/cmd_ide.c boot device found
3136 -44 common/cmd_ide.c Device not available
3137 44 common/cmd_ide.c Device available
3138 -45 common/cmd_ide.c wrong partition selected
3139 45 common/cmd_ide.c partition selected
3140 -46 common/cmd_ide.c Unknown partition table
3141 46 common/cmd_ide.c valid partition table found
3142 -47 common/cmd_ide.c Invalid partition type
3143 47 common/cmd_ide.c correct partition type
3144 -48 common/cmd_ide.c Error reading Image Header on boot device
3145 48 common/cmd_ide.c reading Image Header from IDE device OK
3146 -49 common/cmd_ide.c Image header has bad magic number
3147 49 common/cmd_ide.c Image header has correct magic number
3148 -50 common/cmd_ide.c Image header has bad checksum
3149 50 common/cmd_ide.c Image header has correct checksum
3150 -51 common/cmd_ide.c Error reading Image from IDE device
3151 51 common/cmd_ide.c reading Image from IDE device OK
3152 52 common/cmd_nand.c before loading a Image from a NAND device
3153 -53 common/cmd_nand.c Bad usage of "nand" command
3154 53 common/cmd_nand.c correct usage of "nand" command
3155 -54 common/cmd_nand.c No boot device
3156 54 common/cmd_nand.c boot device found
3157 -55 common/cmd_nand.c Unknown Chip ID on boot device
3158 55 common/cmd_nand.c correct chip ID found, device available
3159 -56 common/cmd_nand.c Error reading Image Header on boot device
3160 56 common/cmd_nand.c reading Image Header from NAND device OK
3161 -57 common/cmd_nand.c Image header has bad magic number
3162 57 common/cmd_nand.c Image header has correct magic number
3163 -58 common/cmd_nand.c Error reading Image from NAND device
3164 58 common/cmd_nand.c reading Image from NAND device OK
3166 -60 common/env_common.c Environment has a bad CRC, using default
3168 64 net/eth.c starting with Ethernet configuration.
3169 -64 net/eth.c no Ethernet found.
3170 65 net/eth.c Ethernet found.
3172 -80 common/cmd_net.c usage wrong
3173 80 common/cmd_net.c before calling net_loop()
3174 -81 common/cmd_net.c some error in net_loop() occurred
3175 81 common/cmd_net.c net_loop() back without error
3176 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3177 82 common/cmd_net.c trying automatic boot
3178 83 common/cmd_net.c running "source" command
3179 -83 common/cmd_net.c some error in automatic boot or "source" command
3180 84 common/cmd_net.c end without errors
3185 100 common/cmd_bootm.c Kernel FIT Image has correct format
3186 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3187 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3188 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3189 102 common/cmd_bootm.c Kernel unit name specified
3190 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3191 103 common/cmd_bootm.c Found configuration node
3192 104 common/cmd_bootm.c Got kernel subimage node offset
3193 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3194 105 common/cmd_bootm.c Kernel subimage hash verification OK
3195 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3196 106 common/cmd_bootm.c Architecture check OK
3197 -106 common/cmd_bootm.c Kernel subimage has wrong type
3198 107 common/cmd_bootm.c Kernel subimage type OK
3199 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3200 108 common/cmd_bootm.c Got kernel subimage data/size
3201 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3202 -109 common/cmd_bootm.c Can't get kernel subimage type
3203 -110 common/cmd_bootm.c Can't get kernel subimage comp
3204 -111 common/cmd_bootm.c Can't get kernel subimage os
3205 -112 common/cmd_bootm.c Can't get kernel subimage load address
3206 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3208 120 common/image.c Start initial ramdisk verification
3209 -120 common/image.c Ramdisk FIT image has incorrect format
3210 121 common/image.c Ramdisk FIT image has correct format
3211 122 common/image.c No ramdisk subimage unit name, using configuration
3212 -122 common/image.c Can't get configuration for ramdisk subimage
3213 123 common/image.c Ramdisk unit name specified
3214 -124 common/image.c Can't get ramdisk subimage node offset
3215 125 common/image.c Got ramdisk subimage node offset
3216 -125 common/image.c Ramdisk subimage hash verification failed
3217 126 common/image.c Ramdisk subimage hash verification OK
3218 -126 common/image.c Ramdisk subimage for unsupported architecture
3219 127 common/image.c Architecture check OK
3220 -127 common/image.c Can't get ramdisk subimage data/size
3221 128 common/image.c Got ramdisk subimage data/size
3222 129 common/image.c Can't get ramdisk load address
3223 -129 common/image.c Got ramdisk load address
3225 -130 common/cmd_doc.c Incorrect FIT image format
3226 131 common/cmd_doc.c FIT image format OK
3228 -140 common/cmd_ide.c Incorrect FIT image format
3229 141 common/cmd_ide.c FIT image format OK
3231 -150 common/cmd_nand.c Incorrect FIT image format
3232 151 common/cmd_nand.c FIT image format OK
3234 - legacy image format:
3235 CONFIG_IMAGE_FORMAT_LEGACY
3236 enables the legacy image format support in U-Boot.
3239 enabled if CONFIG_FIT_SIGNATURE is not defined.
3241 CONFIG_DISABLE_IMAGE_LEGACY
3242 disable the legacy image format
3244 This define is introduced, as the legacy image format is
3245 enabled per default for backward compatibility.
3247 - FIT image support:
3248 CONFIG_FIT_DISABLE_SHA256
3249 Supporting SHA256 hashes has quite an impact on binary size.
3250 For constrained systems sha256 hash support can be disabled
3253 TODO(sjg@chromium.org): Adjust this option to be positive,
3254 and move it to Kconfig
3256 - Standalone program support:
3257 CONFIG_STANDALONE_LOAD_ADDR
3259 This option defines a board specific value for the
3260 address where standalone program gets loaded, thus
3261 overwriting the architecture dependent default
3264 - Frame Buffer Address:
3267 Define CONFIG_FB_ADDR if you want to use specific
3268 address for frame buffer. This is typically the case
3269 when using a graphics controller has separate video
3270 memory. U-Boot will then place the frame buffer at
3271 the given address instead of dynamically reserving it
3272 in system RAM by calling lcd_setmem(), which grabs
3273 the memory for the frame buffer depending on the
3274 configured panel size.
3276 Please see board_init_f function.
3278 - Automatic software updates via TFTP server
3280 CONFIG_UPDATE_TFTP_CNT_MAX
3281 CONFIG_UPDATE_TFTP_MSEC_MAX
3283 These options enable and control the auto-update feature;
3284 for a more detailed description refer to doc/README.update.
3286 - MTD Support (mtdparts command, UBI support)
3289 Adds the MTD device infrastructure from the Linux kernel.
3290 Needed for mtdparts command support.
3292 CONFIG_MTD_PARTITIONS
3294 Adds the MTD partitioning infrastructure from the Linux
3295 kernel. Needed for UBI support.
3300 Adds commands for interacting with MTD partitions formatted
3301 with the UBI flash translation layer
3303 Requires also defining CONFIG_RBTREE
3305 CONFIG_UBI_SILENCE_MSG
3307 Make the verbose messages from UBI stop printing. This leaves
3308 warnings and errors enabled.
3311 CONFIG_MTD_UBI_WL_THRESHOLD
3312 This parameter defines the maximum difference between the highest
3313 erase counter value and the lowest erase counter value of eraseblocks
3314 of UBI devices. When this threshold is exceeded, UBI starts performing
3315 wear leveling by means of moving data from eraseblock with low erase
3316 counter to eraseblocks with high erase counter.
3318 The default value should be OK for SLC NAND flashes, NOR flashes and
3319 other flashes which have eraseblock life-cycle 100000 or more.
3320 However, in case of MLC NAND flashes which typically have eraseblock
3321 life-cycle less than 10000, the threshold should be lessened (e.g.,
3322 to 128 or 256, although it does not have to be power of 2).
3326 CONFIG_MTD_UBI_BEB_LIMIT
3327 This option specifies the maximum bad physical eraseblocks UBI
3328 expects on the MTD device (per 1024 eraseblocks). If the
3329 underlying flash does not admit of bad eraseblocks (e.g. NOR
3330 flash), this value is ignored.
3332 NAND datasheets often specify the minimum and maximum NVM
3333 (Number of Valid Blocks) for the flashes' endurance lifetime.
3334 The maximum expected bad eraseblocks per 1024 eraseblocks
3335 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
3336 which gives 20 for most NANDs (MaxNVB is basically the total
3337 count of eraseblocks on the chip).
3339 To put it differently, if this value is 20, UBI will try to
3340 reserve about 1.9% of physical eraseblocks for bad blocks
3341 handling. And that will be 1.9% of eraseblocks on the entire
3342 NAND chip, not just the MTD partition UBI attaches. This means
3343 that if you have, say, a NAND flash chip admits maximum 40 bad
3344 eraseblocks, and it is split on two MTD partitions of the same
3345 size, UBI will reserve 40 eraseblocks when attaching a
3350 CONFIG_MTD_UBI_FASTMAP
3351 Fastmap is a mechanism which allows attaching an UBI device
3352 in nearly constant time. Instead of scanning the whole MTD device it
3353 only has to locate a checkpoint (called fastmap) on the device.
3354 The on-flash fastmap contains all information needed to attach
3355 the device. Using fastmap makes only sense on large devices where
3356 attaching by scanning takes long. UBI will not automatically install
3357 a fastmap on old images, but you can set the UBI parameter
3358 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
3359 that fastmap-enabled images are still usable with UBI implementations
3360 without fastmap support. On typical flash devices the whole fastmap
3361 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
3363 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
3364 Set this parameter to enable fastmap automatically on images
3368 CONFIG_MTD_UBI_FM_DEBUG
3369 Enable UBI fastmap debug
3375 Adds commands for interacting with UBI volumes formatted as
3376 UBIFS. UBIFS is read-only in u-boot.
3378 Requires UBI support as well as CONFIG_LZO
3380 CONFIG_UBIFS_SILENCE_MSG
3382 Make the verbose messages from UBIFS stop printing. This leaves
3383 warnings and errors enabled.
3387 Enable building of SPL globally.
3390 LDSCRIPT for linking the SPL binary.
3392 CONFIG_SPL_MAX_FOOTPRINT
3393 Maximum size in memory allocated to the SPL, BSS included.
3394 When defined, the linker checks that the actual memory
3395 used by SPL from _start to __bss_end does not exceed it.
3396 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3397 must not be both defined at the same time.
3400 Maximum size of the SPL image (text, data, rodata, and
3401 linker lists sections), BSS excluded.
3402 When defined, the linker checks that the actual size does
3405 CONFIG_SPL_TEXT_BASE
3406 TEXT_BASE for linking the SPL binary.
3408 CONFIG_SPL_RELOC_TEXT_BASE
3409 Address to relocate to. If unspecified, this is equal to
3410 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3412 CONFIG_SPL_BSS_START_ADDR
3413 Link address for the BSS within the SPL binary.
3415 CONFIG_SPL_BSS_MAX_SIZE
3416 Maximum size in memory allocated to the SPL BSS.
3417 When defined, the linker checks that the actual memory used
3418 by SPL from __bss_start to __bss_end does not exceed it.
3419 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3420 must not be both defined at the same time.
3423 Adress of the start of the stack SPL will use
3425 CONFIG_SPL_PANIC_ON_RAW_IMAGE
3426 When defined, SPL will panic() if the image it has
3427 loaded does not have a signature.
3428 Defining this is useful when code which loads images
3429 in SPL cannot guarantee that absolutely all read errors
3431 An example is the LPC32XX MLC NAND driver, which will
3432 consider that a completely unreadable NAND block is bad,
3433 and thus should be skipped silently.
3435 CONFIG_SPL_ABORT_ON_RAW_IMAGE
3436 When defined, SPL will proceed to another boot method
3437 if the image it has loaded does not have a signature.
3439 CONFIG_SPL_RELOC_STACK
3440 Adress of the start of the stack SPL will use after
3441 relocation. If unspecified, this is equal to
3444 CONFIG_SYS_SPL_MALLOC_START
3445 Starting address of the malloc pool used in SPL.
3446 When this option is set the full malloc is used in SPL and
3447 it is set up by spl_init() and before that, the simple malloc()
3448 can be used if CONFIG_SYS_MALLOC_F is defined.
3450 CONFIG_SYS_SPL_MALLOC_SIZE
3451 The size of the malloc pool used in SPL.
3453 CONFIG_SPL_FRAMEWORK
3454 Enable the SPL framework under common/. This framework
3455 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3456 NAND loading of the Linux Kernel.
3459 Enable booting directly to an OS from SPL.
3460 See also: doc/README.falcon
3462 CONFIG_SPL_DISPLAY_PRINT
3463 For ARM, enable an optional function to print more information
3464 about the running system.
3466 CONFIG_SPL_INIT_MINIMAL
3467 Arch init code should be built for a very small image
3469 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3470 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3471 Address and partition on the MMC to load U-Boot from
3472 when the MMC is being used in raw mode.
3474 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
3475 Partition on the MMC to load U-Boot from when the MMC is being
3478 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3479 Sector to load kernel uImage from when MMC is being
3480 used in raw mode (for Falcon mode)
3482 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3483 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3484 Sector and number of sectors to load kernel argument
3485 parameters from when MMC is being used in raw mode
3488 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
3489 Partition on the MMC to load U-Boot from when the MMC is being
3492 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
3493 Filename to read to load U-Boot when reading from filesystem
3495 CONFIG_SPL_FS_LOAD_KERNEL_NAME
3496 Filename to read to load kernel uImage when reading
3497 from filesystem (for Falcon mode)
3499 CONFIG_SPL_FS_LOAD_ARGS_NAME
3500 Filename to read to load kernel argument parameters
3501 when reading from filesystem (for Falcon mode)
3503 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3504 Set this for NAND SPL on PPC mpc83xx targets, so that
3505 start.S waits for the rest of the SPL to load before
3506 continuing (the hardware starts execution after just
3507 loading the first page rather than the full 4K).
3509 CONFIG_SPL_SKIP_RELOCATE
3510 Avoid SPL relocation
3512 CONFIG_SPL_NAND_BASE
3513 Include nand_base.c in the SPL. Requires
3514 CONFIG_SPL_NAND_DRIVERS.
3516 CONFIG_SPL_NAND_DRIVERS
3517 SPL uses normal NAND drivers, not minimal drivers.
3520 Include standard software ECC in the SPL
3522 CONFIG_SPL_NAND_SIMPLE
3523 Support for NAND boot using simple NAND drivers that
3524 expose the cmd_ctrl() interface.
3527 Support for a lightweight UBI (fastmap) scanner and
3530 CONFIG_SPL_NAND_RAW_ONLY
3531 Support to boot only raw u-boot.bin images. Use this only
3532 if you need to save space.
3534 CONFIG_SPL_COMMON_INIT_DDR
3535 Set for common ddr init with serial presence detect in
3538 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3539 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3540 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3541 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3542 CONFIG_SYS_NAND_ECCBYTES
3543 Defines the size and behavior of the NAND that SPL uses
3546 CONFIG_SPL_NAND_BOOT
3547 Add support NAND boot
3549 CONFIG_SYS_NAND_U_BOOT_OFFS
3550 Location in NAND to read U-Boot from
3552 CONFIG_SYS_NAND_U_BOOT_DST
3553 Location in memory to load U-Boot to
3555 CONFIG_SYS_NAND_U_BOOT_SIZE
3556 Size of image to load
3558 CONFIG_SYS_NAND_U_BOOT_START
3559 Entry point in loaded image to jump to
3561 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3562 Define this if you need to first read the OOB and then the
3563 data. This is used, for example, on davinci platforms.
3565 CONFIG_SPL_OMAP3_ID_NAND
3566 Support for an OMAP3-specific set of functions to return the
3567 ID and MFR of the first attached NAND chip, if present.
3569 CONFIG_SPL_RAM_DEVICE
3570 Support for running image already present in ram, in SPL binary
3573 Image offset to which the SPL should be padded before appending
3574 the SPL payload. By default, this is defined as
3575 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3576 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3577 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3580 Final target image containing SPL and payload. Some SPLs
3581 use an arch-specific makefile fragment instead, for
3582 example if more than one image needs to be produced.
3584 CONFIG_FIT_SPL_PRINT
3585 Printing information about a FIT image adds quite a bit of
3586 code to SPL. So this is normally disabled in SPL. Use this
3587 option to re-enable it. This will affect the output of the
3588 bootm command when booting a FIT image.
3592 Enable building of TPL globally.
3595 Image offset to which the TPL should be padded before appending
3596 the TPL payload. By default, this is defined as
3597 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3598 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3599 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3601 - Interrupt support (PPC):
3603 There are common interrupt_init() and timer_interrupt()
3604 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3605 for CPU specific initialization. interrupt_init_cpu()
3606 should set decrementer_count to appropriate value. If
3607 CPU resets decrementer automatically after interrupt
3608 (ppc4xx) it should set decrementer_count to zero.
3609 timer_interrupt() calls timer_interrupt_cpu() for CPU
3610 specific handling. If board has watchdog / status_led
3611 / other_activity_monitor it works automatically from
3612 general timer_interrupt().
3615 Board initialization settings:
3616 ------------------------------
3618 During Initialization u-boot calls a number of board specific functions
3619 to allow the preparation of board specific prerequisites, e.g. pin setup
3620 before drivers are initialized. To enable these callbacks the
3621 following configuration macros have to be defined. Currently this is
3622 architecture specific, so please check arch/your_architecture/lib/board.c
3623 typically in board_init_f() and board_init_r().
3625 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3626 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3627 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3628 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3630 Configuration Settings:
3631 -----------------------
3633 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3634 Optionally it can be defined to support 64-bit memory commands.
3636 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3637 undefine this when you're short of memory.
3639 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3640 width of the commands listed in the 'help' command output.
3642 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3643 prompt for user input.
3645 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3647 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3649 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3651 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3652 the application (usually a Linux kernel) when it is
3655 - CONFIG_SYS_BAUDRATE_TABLE:
3656 List of legal baudrate settings for this board.
3658 - CONFIG_SYS_CONSOLE_INFO_QUIET
3659 Suppress display of console information at boot.
3661 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3662 If the board specific function
3663 extern int overwrite_console (void);
3664 returns 1, the stdin, stderr and stdout are switched to the
3665 serial port, else the settings in the environment are used.
3667 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3668 Enable the call to overwrite_console().
3670 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3671 Enable overwrite of previous console environment settings.
3673 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3674 Begin and End addresses of the area used by the
3677 - CONFIG_SYS_ALT_MEMTEST:
3678 Enable an alternate, more extensive memory test.
3680 - CONFIG_SYS_MEMTEST_SCRATCH:
3681 Scratch address used by the alternate memory test
3682 You only need to set this if address zero isn't writeable
3684 - CONFIG_SYS_MEM_RESERVE_SECURE
3685 Only implemented for ARMv8 for now.
3686 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
3687 is substracted from total RAM and won't be reported to OS.
3688 This memory can be used as secure memory. A variable
3689 gd->arch.secure_ram is used to track the location. In systems
3690 the RAM base is not zero, or RAM is divided into banks,
3691 this variable needs to be recalcuated to get the address.
3693 - CONFIG_SYS_MEM_TOP_HIDE:
3694 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3695 this specified memory area will get subtracted from the top
3696 (end) of RAM and won't get "touched" at all by U-Boot. By
3697 fixing up gd->ram_size the Linux kernel should gets passed
3698 the now "corrected" memory size and won't touch it either.
3699 This should work for arch/ppc and arch/powerpc. Only Linux
3700 board ports in arch/powerpc with bootwrapper support that
3701 recalculate the memory size from the SDRAM controller setup
3702 will have to get fixed in Linux additionally.
3704 This option can be used as a workaround for the 440EPx/GRx
3705 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3708 WARNING: Please make sure that this value is a multiple of
3709 the Linux page size (normally 4k). If this is not the case,
3710 then the end address of the Linux memory will be located at a
3711 non page size aligned address and this could cause major
3714 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3715 Enable temporary baudrate change while serial download
3717 - CONFIG_SYS_SDRAM_BASE:
3718 Physical start address of SDRAM. _Must_ be 0 here.
3720 - CONFIG_SYS_FLASH_BASE:
3721 Physical start address of Flash memory.
3723 - CONFIG_SYS_MONITOR_BASE:
3724 Physical start address of boot monitor code (set by
3725 make config files to be same as the text base address
3726 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3727 CONFIG_SYS_FLASH_BASE when booting from flash.
3729 - CONFIG_SYS_MONITOR_LEN:
3730 Size of memory reserved for monitor code, used to
3731 determine _at_compile_time_ (!) if the environment is
3732 embedded within the U-Boot image, or in a separate
3735 - CONFIG_SYS_MALLOC_LEN:
3736 Size of DRAM reserved for malloc() use.
3738 - CONFIG_SYS_MALLOC_F_LEN
3739 Size of the malloc() pool for use before relocation. If
3740 this is defined, then a very simple malloc() implementation
3741 will become available before relocation. The address is just
3742 below the global data, and the stack is moved down to make
3745 This feature allocates regions with increasing addresses
3746 within the region. calloc() is supported, but realloc()
3747 is not available. free() is supported but does nothing.
3748 The memory will be freed (or in fact just forgotten) when
3749 U-Boot relocates itself.
3751 - CONFIG_SYS_MALLOC_SIMPLE
3752 Provides a simple and small malloc() and calloc() for those
3753 boards which do not use the full malloc in SPL (which is
3754 enabled with CONFIG_SYS_SPL_MALLOC_START).
3756 - CONFIG_SYS_NONCACHED_MEMORY:
3757 Size of non-cached memory area. This area of memory will be
3758 typically located right below the malloc() area and mapped
3759 uncached in the MMU. This is useful for drivers that would
3760 otherwise require a lot of explicit cache maintenance. For
3761 some drivers it's also impossible to properly maintain the
3762 cache. For example if the regions that need to be flushed
3763 are not a multiple of the cache-line size, *and* padding
3764 cannot be allocated between the regions to align them (i.e.
3765 if the HW requires a contiguous array of regions, and the
3766 size of each region is not cache-aligned), then a flush of
3767 one region may result in overwriting data that hardware has
3768 written to another region in the same cache-line. This can
3769 happen for example in network drivers where descriptors for
3770 buffers are typically smaller than the CPU cache-line (e.g.
3771 16 bytes vs. 32 or 64 bytes).
3773 Non-cached memory is only supported on 32-bit ARM at present.
3775 - CONFIG_SYS_BOOTM_LEN:
3776 Normally compressed uImages are limited to an
3777 uncompressed size of 8 MBytes. If this is not enough,
3778 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3779 to adjust this setting to your needs.
3781 - CONFIG_SYS_BOOTMAPSZ:
3782 Maximum size of memory mapped by the startup code of
3783 the Linux kernel; all data that must be processed by
3784 the Linux kernel (bd_info, boot arguments, FDT blob if
3785 used) must be put below this limit, unless "bootm_low"
3786 environment variable is defined and non-zero. In such case
3787 all data for the Linux kernel must be between "bootm_low"
3788 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3789 variable "bootm_mapsize" will override the value of
3790 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3791 then the value in "bootm_size" will be used instead.
3793 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3794 Enable initrd_high functionality. If defined then the
3795 initrd_high feature is enabled and the bootm ramdisk subcommand
3798 - CONFIG_SYS_BOOT_GET_CMDLINE:
3799 Enables allocating and saving kernel cmdline in space between
3800 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3802 - CONFIG_SYS_BOOT_GET_KBD:
3803 Enables allocating and saving a kernel copy of the bd_info in
3804 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3806 - CONFIG_SYS_MAX_FLASH_BANKS:
3807 Max number of Flash memory banks
3809 - CONFIG_SYS_MAX_FLASH_SECT:
3810 Max number of sectors on a Flash chip
3812 - CONFIG_SYS_FLASH_ERASE_TOUT:
3813 Timeout for Flash erase operations (in ms)
3815 - CONFIG_SYS_FLASH_WRITE_TOUT:
3816 Timeout for Flash write operations (in ms)
3818 - CONFIG_SYS_FLASH_LOCK_TOUT
3819 Timeout for Flash set sector lock bit operation (in ms)
3821 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3822 Timeout for Flash clear lock bits operation (in ms)
3824 - CONFIG_SYS_FLASH_PROTECTION
3825 If defined, hardware flash sectors protection is used
3826 instead of U-Boot software protection.
3828 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3830 Enable TFTP transfers directly to flash memory;
3831 without this option such a download has to be
3832 performed in two steps: (1) download to RAM, and (2)
3833 copy from RAM to flash.
3835 The two-step approach is usually more reliable, since
3836 you can check if the download worked before you erase
3837 the flash, but in some situations (when system RAM is
3838 too limited to allow for a temporary copy of the
3839 downloaded image) this option may be very useful.
3841 - CONFIG_SYS_FLASH_CFI:
3842 Define if the flash driver uses extra elements in the
3843 common flash structure for storing flash geometry.
3845 - CONFIG_FLASH_CFI_DRIVER
3846 This option also enables the building of the cfi_flash driver
3847 in the drivers directory
3849 - CONFIG_FLASH_CFI_MTD
3850 This option enables the building of the cfi_mtd driver
3851 in the drivers directory. The driver exports CFI flash
3854 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3855 Use buffered writes to flash.
3857 - CONFIG_FLASH_SPANSION_S29WS_N
3858 s29ws-n MirrorBit flash has non-standard addresses for buffered
3861 - CONFIG_SYS_FLASH_QUIET_TEST
3862 If this option is defined, the common CFI flash doesn't
3863 print it's warning upon not recognized FLASH banks. This
3864 is useful, if some of the configured banks are only
3865 optionally available.
3867 - CONFIG_FLASH_SHOW_PROGRESS
3868 If defined (must be an integer), print out countdown
3869 digits and dots. Recommended value: 45 (9..1) for 80
3870 column displays, 15 (3..1) for 40 column displays.
3872 - CONFIG_FLASH_VERIFY
3873 If defined, the content of the flash (destination) is compared
3874 against the source after the write operation. An error message
3875 will be printed when the contents are not identical.
3876 Please note that this option is useless in nearly all cases,
3877 since such flash programming errors usually are detected earlier
3878 while unprotecting/erasing/programming. Please only enable
3879 this option if you really know what you are doing.
3881 - CONFIG_SYS_RX_ETH_BUFFER:
3882 Defines the number of Ethernet receive buffers. On some
3883 Ethernet controllers it is recommended to set this value
3884 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3885 buffers can be full shortly after enabling the interface
3886 on high Ethernet traffic.
3887 Defaults to 4 if not defined.
3889 - CONFIG_ENV_MAX_ENTRIES
3891 Maximum number of entries in the hash table that is used
3892 internally to store the environment settings. The default
3893 setting is supposed to be generous and should work in most
3894 cases. This setting can be used to tune behaviour; see
3895 lib/hashtable.c for details.
3897 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3898 - CONFIG_ENV_FLAGS_LIST_STATIC
3899 Enable validation of the values given to environment variables when
3900 calling env set. Variables can be restricted to only decimal,
3901 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3902 the variables can also be restricted to IP address or MAC address.
3904 The format of the list is:
3905 type_attribute = [s|d|x|b|i|m]
3906 access_attribute = [a|r|o|c]
3907 attributes = type_attribute[access_attribute]
3908 entry = variable_name[:attributes]
3911 The type attributes are:
3912 s - String (default)
3915 b - Boolean ([1yYtT|0nNfF])
3919 The access attributes are:
3925 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3926 Define this to a list (string) to define the ".flags"
3927 environment variable in the default or embedded environment.
3929 - CONFIG_ENV_FLAGS_LIST_STATIC
3930 Define this to a list (string) to define validation that
3931 should be done if an entry is not found in the ".flags"
3932 environment variable. To override a setting in the static
3933 list, simply add an entry for the same variable name to the
3936 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3937 regular expression. This allows multiple variables to define the same
3938 flags without explicitly listing them for each variable.
3940 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3941 If defined, don't allow the -f switch to env set override variable
3944 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3945 This is set by OMAP boards for the max time that reset should
3946 be asserted. See doc/README.omap-reset-time for details on how
3947 the value can be calculated on a given board.
3950 If stdint.h is available with your toolchain you can define this
3951 option to enable it. You can provide option 'USE_STDINT=1' when
3952 building U-Boot to enable this.
3954 The following definitions that deal with the placement and management
3955 of environment data (variable area); in general, we support the
3956 following configurations:
3958 - CONFIG_BUILD_ENVCRC:
3960 Builds up envcrc with the target environment so that external utils
3961 may easily extract it and embed it in final U-Boot images.
3963 - CONFIG_ENV_IS_IN_FLASH:
3965 Define this if the environment is in flash memory.
3967 a) The environment occupies one whole flash sector, which is
3968 "embedded" in the text segment with the U-Boot code. This
3969 happens usually with "bottom boot sector" or "top boot
3970 sector" type flash chips, which have several smaller
3971 sectors at the start or the end. For instance, such a
3972 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3973 such a case you would place the environment in one of the
3974 4 kB sectors - with U-Boot code before and after it. With
3975 "top boot sector" type flash chips, you would put the
3976 environment in one of the last sectors, leaving a gap
3977 between U-Boot and the environment.
3979 - CONFIG_ENV_OFFSET:
3981 Offset of environment data (variable area) to the
3982 beginning of flash memory; for instance, with bottom boot
3983 type flash chips the second sector can be used: the offset
3984 for this sector is given here.
3986 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3990 This is just another way to specify the start address of
3991 the flash sector containing the environment (instead of
3994 - CONFIG_ENV_SECT_SIZE:
3996 Size of the sector containing the environment.
3999 b) Sometimes flash chips have few, equal sized, BIG sectors.
4000 In such a case you don't want to spend a whole sector for
4005 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4006 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4007 of this flash sector for the environment. This saves
4008 memory for the RAM copy of the environment.
4010 It may also save flash memory if you decide to use this
4011 when your environment is "embedded" within U-Boot code,
4012 since then the remainder of the flash sector could be used
4013 for U-Boot code. It should be pointed out that this is
4014 STRONGLY DISCOURAGED from a robustness point of view:
4015 updating the environment in flash makes it always
4016 necessary to erase the WHOLE sector. If something goes
4017 wrong before the contents has been restored from a copy in
4018 RAM, your target system will be dead.
4020 - CONFIG_ENV_ADDR_REDUND
4021 CONFIG_ENV_SIZE_REDUND
4023 These settings describe a second storage area used to hold
4024 a redundant copy of the environment data, so that there is
4025 a valid backup copy in case there is a power failure during
4026 a "saveenv" operation.
4028 BE CAREFUL! Any changes to the flash layout, and some changes to the
4029 source code will make it necessary to adapt <board>/u-boot.lds*
4033 - CONFIG_ENV_IS_IN_NVRAM:
4035 Define this if you have some non-volatile memory device
4036 (NVRAM, battery buffered SRAM) which you want to use for the
4042 These two #defines are used to determine the memory area you
4043 want to use for environment. It is assumed that this memory
4044 can just be read and written to, without any special
4047 BE CAREFUL! The first access to the environment happens quite early
4048 in U-Boot initialization (when we try to get the setting of for the
4049 console baudrate). You *MUST* have mapped your NVRAM area then, or
4052 Please note that even with NVRAM we still use a copy of the
4053 environment in RAM: we could work on NVRAM directly, but we want to
4054 keep settings there always unmodified except somebody uses "saveenv"
4055 to save the current settings.
4058 - CONFIG_ENV_IS_IN_EEPROM:
4060 Use this if you have an EEPROM or similar serial access
4061 device and a driver for it.
4063 - CONFIG_ENV_OFFSET:
4066 These two #defines specify the offset and size of the
4067 environment area within the total memory of your EEPROM.
4069 - CONFIG_SYS_I2C_EEPROM_ADDR:
4070 If defined, specified the chip address of the EEPROM device.
4071 The default address is zero.
4073 - CONFIG_SYS_I2C_EEPROM_BUS:
4074 If defined, specified the i2c bus of the EEPROM device.
4076 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4077 If defined, the number of bits used to address bytes in a
4078 single page in the EEPROM device. A 64 byte page, for example
4079 would require six bits.
4081 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4082 If defined, the number of milliseconds to delay between
4083 page writes. The default is zero milliseconds.
4085 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4086 The length in bytes of the EEPROM memory array address. Note
4087 that this is NOT the chip address length!
4089 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4090 EEPROM chips that implement "address overflow" are ones
4091 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4092 address and the extra bits end up in the "chip address" bit
4093 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4096 Note that we consider the length of the address field to
4097 still be one byte because the extra address bits are hidden
4098 in the chip address.
4100 - CONFIG_SYS_EEPROM_SIZE:
4101 The size in bytes of the EEPROM device.
4103 - CONFIG_ENV_EEPROM_IS_ON_I2C
4104 define this, if you have I2C and SPI activated, and your
4105 EEPROM, which holds the environment, is on the I2C bus.
4107 - CONFIG_I2C_ENV_EEPROM_BUS
4108 if you have an Environment on an EEPROM reached over
4109 I2C muxes, you can define here, how to reach this
4110 EEPROM. For example:
4112 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4114 EEPROM which holds the environment, is reached over
4115 a pca9547 i2c mux with address 0x70, channel 3.
4117 - CONFIG_ENV_IS_IN_DATAFLASH:
4119 Define this if you have a DataFlash memory device which you
4120 want to use for the environment.
4122 - CONFIG_ENV_OFFSET:
4126 These three #defines specify the offset and size of the
4127 environment area within the total memory of your DataFlash placed
4128 at the specified address.
4130 - CONFIG_ENV_IS_IN_SPI_FLASH:
4132 Define this if you have a SPI Flash memory device which you
4133 want to use for the environment.
4135 - CONFIG_ENV_OFFSET:
4138 These two #defines specify the offset and size of the
4139 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4140 aligned to an erase sector boundary.
4142 - CONFIG_ENV_SECT_SIZE:
4144 Define the SPI flash's sector size.
4146 - CONFIG_ENV_OFFSET_REDUND (optional):
4148 This setting describes a second storage area of CONFIG_ENV_SIZE
4149 size used to hold a redundant copy of the environment data, so
4150 that there is a valid backup copy in case there is a power failure
4151 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4152 aligned to an erase sector boundary.
4154 - CONFIG_ENV_SPI_BUS (optional):
4155 - CONFIG_ENV_SPI_CS (optional):
4157 Define the SPI bus and chip select. If not defined they will be 0.
4159 - CONFIG_ENV_SPI_MAX_HZ (optional):
4161 Define the SPI max work clock. If not defined then use 1MHz.
4163 - CONFIG_ENV_SPI_MODE (optional):
4165 Define the SPI work mode. If not defined then use SPI_MODE_3.
4167 - CONFIG_ENV_IS_IN_REMOTE:
4169 Define this if you have a remote memory space which you
4170 want to use for the local device's environment.
4175 These two #defines specify the address and size of the
4176 environment area within the remote memory space. The
4177 local device can get the environment from remote memory
4178 space by SRIO or PCIE links.
4180 BE CAREFUL! For some special cases, the local device can not use
4181 "saveenv" command. For example, the local device will get the
4182 environment stored in a remote NOR flash by SRIO or PCIE link,
4183 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4185 - CONFIG_ENV_IS_IN_NAND:
4187 Define this if you have a NAND device which you want to use
4188 for the environment.
4190 - CONFIG_ENV_OFFSET:
4193 These two #defines specify the offset and size of the environment
4194 area within the first NAND device. CONFIG_ENV_OFFSET must be
4195 aligned to an erase block boundary.
4197 - CONFIG_ENV_OFFSET_REDUND (optional):
4199 This setting describes a second storage area of CONFIG_ENV_SIZE
4200 size used to hold a redundant copy of the environment data, so
4201 that there is a valid backup copy in case there is a power failure
4202 during a "saveenv" operation. CONFIG_ENV_OFFSET_REDUND must be
4203 aligned to an erase block boundary.
4205 - CONFIG_ENV_RANGE (optional):
4207 Specifies the length of the region in which the environment
4208 can be written. This should be a multiple of the NAND device's
4209 block size. Specifying a range with more erase blocks than
4210 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4211 the range to be avoided.
4213 - CONFIG_ENV_OFFSET_OOB (optional):
4215 Enables support for dynamically retrieving the offset of the
4216 environment from block zero's out-of-band data. The
4217 "nand env.oob" command can be used to record this offset.
4218 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4219 using CONFIG_ENV_OFFSET_OOB.
4221 - CONFIG_NAND_ENV_DST
4223 Defines address in RAM to which the nand_spl code should copy the
4224 environment. If redundant environment is used, it will be copied to
4225 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4227 - CONFIG_ENV_IS_IN_UBI:
4229 Define this if you have an UBI volume that you want to use for the
4230 environment. This has the benefit of wear-leveling the environment
4231 accesses, which is important on NAND.
4233 - CONFIG_ENV_UBI_PART:
4235 Define this to a string that is the mtd partition containing the UBI.
4237 - CONFIG_ENV_UBI_VOLUME:
4239 Define this to the name of the volume that you want to store the
4242 - CONFIG_ENV_UBI_VOLUME_REDUND:
4244 Define this to the name of another volume to store a second copy of
4245 the environment in. This will enable redundant environments in UBI.
4246 It is assumed that both volumes are in the same MTD partition.
4248 - CONFIG_UBI_SILENCE_MSG
4249 - CONFIG_UBIFS_SILENCE_MSG
4251 You will probably want to define these to avoid a really noisy system
4252 when storing the env in UBI.
4254 - CONFIG_ENV_IS_IN_FAT:
4255 Define this if you want to use the FAT file system for the environment.
4257 - FAT_ENV_INTERFACE:
4259 Define this to a string that is the name of the block device.
4261 - FAT_ENV_DEV_AND_PART:
4263 Define this to a string to specify the partition of the device. It can
4266 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4267 - "D:P": device D partition P. Error occurs if device D has no
4270 - "D" or "D:": device D partition 1 if device D has partition
4271 table, or the whole device D if has no partition
4273 - "D:auto": first partition in device D with bootable flag set.
4274 If none, first valid partition in device D. If no
4275 partition table then means device D.
4279 It's a string of the FAT file name. This file use to store the
4283 This should be defined. Otherwise it cannot save the environment file.
4285 - CONFIG_ENV_IS_IN_MMC:
4287 Define this if you have an MMC device which you want to use for the
4290 - CONFIG_SYS_MMC_ENV_DEV:
4292 Specifies which MMC device the environment is stored in.
4294 - CONFIG_SYS_MMC_ENV_PART (optional):
4296 Specifies which MMC partition the environment is stored in. If not
4297 set, defaults to partition 0, the user area. Common values might be
4298 1 (first MMC boot partition), 2 (second MMC boot partition).
4300 - CONFIG_ENV_OFFSET:
4303 These two #defines specify the offset and size of the environment
4304 area within the specified MMC device.
4306 If offset is positive (the usual case), it is treated as relative to
4307 the start of the MMC partition. If offset is negative, it is treated
4308 as relative to the end of the MMC partition. This can be useful if
4309 your board may be fitted with different MMC devices, which have
4310 different sizes for the MMC partitions, and you always want the
4311 environment placed at the very end of the partition, to leave the
4312 maximum possible space before it, to store other data.
4314 These two values are in units of bytes, but must be aligned to an
4315 MMC sector boundary.
4317 - CONFIG_ENV_OFFSET_REDUND (optional):
4319 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4320 hold a redundant copy of the environment data. This provides a
4321 valid backup copy in case the other copy is corrupted, e.g. due
4322 to a power failure during a "saveenv" operation.
4324 This value may also be positive or negative; this is handled in the
4325 same way as CONFIG_ENV_OFFSET.
4327 This value is also in units of bytes, but must also be aligned to
4328 an MMC sector boundary.
4330 - CONFIG_ENV_SIZE_REDUND (optional):
4332 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4333 set. If this value is set, it must be set to the same value as
4336 - CONFIG_SYS_SPI_INIT_OFFSET
4338 Defines offset to the initial SPI buffer area in DPRAM. The
4339 area is used at an early stage (ROM part) if the environment
4340 is configured to reside in the SPI EEPROM: We need a 520 byte
4341 scratch DPRAM area. It is used between the two initialization
4342 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4343 to be a good choice since it makes it far enough from the
4344 start of the data area as well as from the stack pointer.
4346 Please note that the environment is read-only until the monitor
4347 has been relocated to RAM and a RAM copy of the environment has been
4348 created; also, when using EEPROM you will have to use getenv_f()
4349 until then to read environment variables.
4351 The environment is protected by a CRC32 checksum. Before the monitor
4352 is relocated into RAM, as a result of a bad CRC you will be working
4353 with the compiled-in default environment - *silently*!!! [This is
4354 necessary, because the first environment variable we need is the
4355 "baudrate" setting for the console - if we have a bad CRC, we don't
4356 have any device yet where we could complain.]
4358 Note: once the monitor has been relocated, then it will complain if
4359 the default environment is used; a new CRC is computed as soon as you
4360 use the "saveenv" command to store a valid environment.
4362 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4363 Echo the inverted Ethernet link state to the fault LED.
4365 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4366 also needs to be defined.
4368 - CONFIG_SYS_FAULT_MII_ADDR:
4369 MII address of the PHY to check for the Ethernet link state.
4371 - CONFIG_NS16550_MIN_FUNCTIONS:
4372 Define this if you desire to only have use of the NS16550_init
4373 and NS16550_putc functions for the serial driver located at
4374 drivers/serial/ns16550.c. This option is useful for saving
4375 space for already greatly restricted images, including but not
4376 limited to NAND_SPL configurations.
4378 - CONFIG_DISPLAY_BOARDINFO
4379 Display information about the board that U-Boot is running on
4380 when U-Boot starts up. The board function checkboard() is called
4383 - CONFIG_DISPLAY_BOARDINFO_LATE
4384 Similar to the previous option, but display this information
4385 later, once stdio is running and output goes to the LCD, if
4388 - CONFIG_BOARD_SIZE_LIMIT:
4389 Maximum size of the U-Boot image. When defined, the
4390 build system checks that the actual size does not
4393 Low Level (hardware related) configuration options:
4394 ---------------------------------------------------
4396 - CONFIG_SYS_CACHELINE_SIZE:
4397 Cache Line Size of the CPU.
4399 - CONFIG_SYS_DEFAULT_IMMR:
4400 Default address of the IMMR after system reset.
4402 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4403 and RPXsuper) to be able to adjust the position of
4404 the IMMR register after a reset.
4406 - CONFIG_SYS_CCSRBAR_DEFAULT:
4407 Default (power-on reset) physical address of CCSR on Freescale
4410 - CONFIG_SYS_CCSRBAR:
4411 Virtual address of CCSR. On a 32-bit build, this is typically
4412 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4414 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4415 for cross-platform code that uses that macro instead.
4417 - CONFIG_SYS_CCSRBAR_PHYS:
4418 Physical address of CCSR. CCSR can be relocated to a new
4419 physical address, if desired. In this case, this macro should
4420 be set to that address. Otherwise, it should be set to the
4421 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4422 is typically relocated on 36-bit builds. It is recommended
4423 that this macro be defined via the _HIGH and _LOW macros:
4425 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4426 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4428 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4429 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4430 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4431 used in assembly code, so it must not contain typecasts or
4432 integer size suffixes (e.g. "ULL").
4434 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4435 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4436 used in assembly code, so it must not contain typecasts or
4437 integer size suffixes (e.g. "ULL").
4439 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4440 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4441 forced to a value that ensures that CCSR is not relocated.
4443 - Floppy Disk Support:
4444 CONFIG_SYS_FDC_DRIVE_NUMBER
4446 the default drive number (default value 0)
4448 CONFIG_SYS_ISA_IO_STRIDE
4450 defines the spacing between FDC chipset registers
4453 CONFIG_SYS_ISA_IO_OFFSET
4455 defines the offset of register from address. It
4456 depends on which part of the data bus is connected to
4457 the FDC chipset. (default value 0)
4459 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4460 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4463 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4464 fdc_hw_init() is called at the beginning of the FDC
4465 setup. fdc_hw_init() must be provided by the board
4466 source code. It is used to make hardware-dependent
4470 Most IDE controllers were designed to be connected with PCI
4471 interface. Only few of them were designed for AHB interface.
4472 When software is doing ATA command and data transfer to
4473 IDE devices through IDE-AHB controller, some additional
4474 registers accessing to these kind of IDE-AHB controller
4477 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4478 DO NOT CHANGE unless you know exactly what you're
4479 doing! (11-4) [MPC8xx/82xx systems only]
4481 - CONFIG_SYS_INIT_RAM_ADDR:
4483 Start address of memory area that can be used for
4484 initial data and stack; please note that this must be
4485 writable memory that is working WITHOUT special
4486 initialization, i. e. you CANNOT use normal RAM which
4487 will become available only after programming the
4488 memory controller and running certain initialization
4491 U-Boot uses the following memory types:
4492 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4493 - MPC824X: data cache
4494 - PPC4xx: data cache
4496 - CONFIG_SYS_GBL_DATA_OFFSET:
4498 Offset of the initial data structure in the memory
4499 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4500 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4501 data is located at the end of the available space
4502 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4503 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4504 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4505 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4508 On the MPC824X (or other systems that use the data
4509 cache for initial memory) the address chosen for
4510 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4511 point to an otherwise UNUSED address space between
4512 the top of RAM and the start of the PCI space.
4514 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4516 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4518 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4520 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4522 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4524 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4526 - CONFIG_SYS_OR_TIMING_SDRAM:
4529 - CONFIG_SYS_MAMR_PTA:
4530 periodic timer for refresh
4532 - CONFIG_SYS_DER: Debug Event Register (37-47)
4534 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4535 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4536 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4537 CONFIG_SYS_BR1_PRELIM:
4538 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4540 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4541 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4542 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4543 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4545 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4546 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4547 Machine Mode Register and Memory Periodic Timer
4548 Prescaler definitions (SDRAM timing)
4550 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4551 enable I2C microcode relocation patch (MPC8xx);
4552 define relocation offset in DPRAM [DSP2]
4554 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4555 enable SMC microcode relocation patch (MPC8xx);
4556 define relocation offset in DPRAM [SMC1]
4558 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4559 enable SPI microcode relocation patch (MPC8xx);
4560 define relocation offset in DPRAM [SCC4]
4562 - CONFIG_SYS_USE_OSCCLK:
4563 Use OSCM clock mode on MBX8xx board. Be careful,
4564 wrong setting might damage your board. Read
4565 doc/README.MBX before setting this variable!
4567 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4568 Offset of the bootmode word in DPRAM used by post
4569 (Power On Self Tests). This definition overrides
4570 #define'd default value in commproc.h resp.
4573 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4574 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4575 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4576 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4577 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4578 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4579 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4580 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4581 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4583 - CONFIG_PCI_DISABLE_PCIE:
4584 Disable PCI-Express on systems where it is supported but not
4587 - CONFIG_PCI_ENUM_ONLY
4588 Only scan through and get the devices on the buses.
4589 Don't do any setup work, presumably because someone or
4590 something has already done it, and we don't need to do it
4591 a second time. Useful for platforms that are pre-booted
4592 by coreboot or similar.
4594 - CONFIG_PCI_INDIRECT_BRIDGE:
4595 Enable support for indirect PCI bridges.
4598 Chip has SRIO or not
4601 Board has SRIO 1 port available
4604 Board has SRIO 2 port available
4606 - CONFIG_SRIO_PCIE_BOOT_MASTER
4607 Board can support master function for Boot from SRIO and PCIE
4609 - CONFIG_SYS_SRIOn_MEM_VIRT:
4610 Virtual Address of SRIO port 'n' memory region
4612 - CONFIG_SYS_SRIOn_MEM_PHYS:
4613 Physical Address of SRIO port 'n' memory region
4615 - CONFIG_SYS_SRIOn_MEM_SIZE:
4616 Size of SRIO port 'n' memory region
4618 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4619 Defined to tell the NAND controller that the NAND chip is using
4621 Not all NAND drivers use this symbol.
4622 Example of drivers that use it:
4623 - drivers/mtd/nand/ndfc.c
4624 - drivers/mtd/nand/mxc_nand.c
4626 - CONFIG_SYS_NDFC_EBC0_CFG
4627 Sets the EBC0_CFG register for the NDFC. If not defined
4628 a default value will be used.
4631 Get DDR timing information from an I2C EEPROM. Common
4632 with pluggable memory modules such as SODIMMs
4635 I2C address of the SPD EEPROM
4637 - CONFIG_SYS_SPD_BUS_NUM
4638 If SPD EEPROM is on an I2C bus other than the first
4639 one, specify here. Note that the value must resolve
4640 to something your driver can deal with.
4642 - CONFIG_SYS_DDR_RAW_TIMING
4643 Get DDR timing information from other than SPD. Common with
4644 soldered DDR chips onboard without SPD. DDR raw timing
4645 parameters are extracted from datasheet and hard-coded into
4646 header files or board specific files.
4648 - CONFIG_FSL_DDR_INTERACTIVE
4649 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4651 - CONFIG_FSL_DDR_SYNC_REFRESH
4652 Enable sync of refresh for multiple controllers.
4654 - CONFIG_FSL_DDR_BIST
4655 Enable built-in memory test for Freescale DDR controllers.
4657 - CONFIG_SYS_83XX_DDR_USES_CS0
4658 Only for 83xx systems. If specified, then DDR should
4659 be configured using CS0 and CS1 instead of CS2 and CS3.
4661 - CONFIG_ETHER_ON_FEC[12]
4662 Define to enable FEC[12] on a 8xx series processor.
4664 - CONFIG_FEC[12]_PHY
4665 Define to the hardcoded PHY address which corresponds
4666 to the given FEC; i. e.
4667 #define CONFIG_FEC1_PHY 4
4668 means that the PHY with address 4 is connected to FEC1
4670 When set to -1, means to probe for first available.
4672 - CONFIG_FEC[12]_PHY_NORXERR
4673 The PHY does not have a RXERR line (RMII only).
4674 (so program the FEC to ignore it).
4677 Enable RMII mode for all FECs.
4678 Note that this is a global option, we can't
4679 have one FEC in standard MII mode and another in RMII mode.
4681 - CONFIG_CRC32_VERIFY
4682 Add a verify option to the crc32 command.
4685 => crc32 -v <address> <count> <crc32>
4687 Where address/count indicate a memory area
4688 and crc32 is the correct crc32 which the
4692 Add the "loopw" memory command. This only takes effect if
4693 the memory commands are activated globally (CONFIG_CMD_MEM).
4696 Add the "mdc" and "mwc" memory commands. These are cyclic
4701 This command will print 4 bytes (10,11,12,13) each 500 ms.
4703 => mwc.l 100 12345678 10
4704 This command will write 12345678 to address 100 all 10 ms.
4706 This only takes effect if the memory commands are activated
4707 globally (CONFIG_CMD_MEM).
4709 - CONFIG_SKIP_LOWLEVEL_INIT
4710 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4711 low level initializations (like setting up the memory
4712 controller) are omitted and/or U-Boot does not
4713 relocate itself into RAM.
4715 Normally this variable MUST NOT be defined. The only
4716 exception is when U-Boot is loaded (to RAM) by some
4717 other boot loader or by a debugger which performs
4718 these initializations itself.
4720 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
4721 [ARM926EJ-S only] This allows just the call to lowlevel_init()
4722 to be skipped. The normal CP15 init (such as enabling the
4723 instruction cache) is still performed.
4726 Modifies the behaviour of start.S when compiling a loader
4727 that is executed before the actual U-Boot. E.g. when
4728 compiling a NAND SPL.
4731 Modifies the behaviour of start.S when compiling a loader
4732 that is executed after the SPL and before the actual U-Boot.
4733 It is loaded by the SPL.
4735 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4736 Only for 85xx systems. If this variable is specified, the section
4737 .resetvec is not kept and the section .bootpg is placed in the
4738 previous 4k of the .text section.
4740 - CONFIG_ARCH_MAP_SYSMEM
4741 Generally U-Boot (and in particular the md command) uses
4742 effective address. It is therefore not necessary to regard
4743 U-Boot address as virtual addresses that need to be translated
4744 to physical addresses. However, sandbox requires this, since
4745 it maintains its own little RAM buffer which contains all
4746 addressable memory. This option causes some memory accesses
4747 to be mapped through map_sysmem() / unmap_sysmem().
4749 - CONFIG_USE_ARCH_MEMCPY
4750 CONFIG_USE_ARCH_MEMSET
4751 If these options are used a optimized version of memcpy/memset will
4752 be used if available. These functions may be faster under some
4753 conditions but may increase the binary size.
4755 - CONFIG_X86_RESET_VECTOR
4756 If defined, the x86 reset vector code is included. This is not
4757 needed when U-Boot is running from Coreboot.
4760 Defines the MPU clock speed (in MHz).
4762 NOTE : currently only supported on AM335x platforms.
4764 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4765 Enables the RTC32K OSC on AM33xx based plattforms
4767 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4768 Option to disable subpage write in NAND driver
4769 driver that uses this:
4770 drivers/mtd/nand/davinci_nand.c
4772 Freescale QE/FMAN Firmware Support:
4773 -----------------------------------
4775 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4776 loading of "firmware", which is encoded in the QE firmware binary format.
4777 This firmware often needs to be loaded during U-Boot booting, so macros
4778 are used to identify the storage device (NOR flash, SPI, etc) and the address
4781 - CONFIG_SYS_FMAN_FW_ADDR
4782 The address in the storage device where the FMAN microcode is located. The
4783 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4786 - CONFIG_SYS_QE_FW_ADDR
4787 The address in the storage device where the QE microcode is located. The
4788 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4791 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4792 The maximum possible size of the firmware. The firmware binary format
4793 has a field that specifies the actual size of the firmware, but it
4794 might not be possible to read any part of the firmware unless some
4795 local storage is allocated to hold the entire firmware first.
4797 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4798 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4799 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4800 virtual address in NOR flash.
4802 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4803 Specifies that QE/FMAN firmware is located in NAND flash.
4804 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4806 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4807 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4808 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4810 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4811 Specifies that QE/FMAN firmware is located in the remote (master)
4812 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4813 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4814 window->master inbound window->master LAW->the ucode address in
4815 master's memory space.
4817 Freescale Layerscape Management Complex Firmware Support:
4818 ---------------------------------------------------------
4819 The Freescale Layerscape Management Complex (MC) supports the loading of
4821 This firmware often needs to be loaded during U-Boot booting, so macros
4822 are used to identify the storage device (NOR flash, SPI, etc) and the address
4825 - CONFIG_FSL_MC_ENET
4826 Enable the MC driver for Layerscape SoCs.
4828 Freescale Layerscape Debug Server Support:
4829 -------------------------------------------
4830 The Freescale Layerscape Debug Server Support supports the loading of
4831 "Debug Server firmware" and triggering SP boot-rom.
4832 This firmware often needs to be loaded during U-Boot booting.
4834 - CONFIG_SYS_MC_RSV_MEM_ALIGN
4835 Define alignment of reserved memory MC requires
4840 In order to achieve reproducible builds, timestamps used in the U-Boot build
4841 process have to be set to a fixed value.
4843 This is done using the SOURCE_DATE_EPOCH environment variable.
4844 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
4845 option for U-Boot or an environment variable in U-Boot.
4847 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
4849 Building the Software:
4850 ======================
4852 Building U-Boot has been tested in several native build environments
4853 and in many different cross environments. Of course we cannot support
4854 all possibly existing versions of cross development tools in all
4855 (potentially obsolete) versions. In case of tool chain problems we
4856 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4857 which is extensively used to build and test U-Boot.
4859 If you are not using a native environment, it is assumed that you
4860 have GNU cross compiling tools available in your path. In this case,
4861 you must set the environment variable CROSS_COMPILE in your shell.
4862 Note that no changes to the Makefile or any other source files are
4863 necessary. For example using the ELDK on a 4xx CPU, please enter:
4865 $ CROSS_COMPILE=ppc_4xx-
4866 $ export CROSS_COMPILE
4868 Note: If you wish to generate Windows versions of the utilities in
4869 the tools directory you can use the MinGW toolchain
4870 (http://www.mingw.org). Set your HOST tools to the MinGW
4871 toolchain and execute 'make tools'. For example:
4873 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4875 Binaries such as tools/mkimage.exe will be created which can
4876 be executed on computers running Windows.
4878 U-Boot is intended to be simple to build. After installing the
4879 sources you must configure U-Boot for one specific board type. This
4884 where "NAME_defconfig" is the name of one of the existing configu-
4885 rations; see boards.cfg for supported names.
4887 Note: for some board special configuration names may exist; check if
4888 additional information is available from the board vendor; for
4889 instance, the TQM823L systems are available without (standard)
4890 or with LCD support. You can select such additional "features"
4891 when choosing the configuration, i. e.
4893 make TQM823L_defconfig
4894 - will configure for a plain TQM823L, i. e. no LCD support
4896 make TQM823L_LCD_defconfig
4897 - will configure for a TQM823L with U-Boot console on LCD
4902 Finally, type "make all", and you should get some working U-Boot
4903 images ready for download to / installation on your system:
4905 - "u-boot.bin" is a raw binary image
4906 - "u-boot" is an image in ELF binary format
4907 - "u-boot.srec" is in Motorola S-Record format
4909 By default the build is performed locally and the objects are saved
4910 in the source directory. One of the two methods can be used to change
4911 this behavior and build U-Boot to some external directory:
4913 1. Add O= to the make command line invocations:
4915 make O=/tmp/build distclean
4916 make O=/tmp/build NAME_defconfig
4917 make O=/tmp/build all
4919 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
4921 export KBUILD_OUTPUT=/tmp/build
4926 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
4930 Please be aware that the Makefiles assume you are using GNU make, so
4931 for instance on NetBSD you might need to use "gmake" instead of
4935 If the system board that you have is not listed, then you will need
4936 to port U-Boot to your hardware platform. To do this, follow these
4939 1. Create a new directory to hold your board specific code. Add any
4940 files you need. In your board directory, you will need at least
4941 the "Makefile" and a "<board>.c".
4942 2. Create a new configuration file "include/configs/<board>.h" for
4944 3. If you're porting U-Boot to a new CPU, then also create a new
4945 directory to hold your CPU specific code. Add any files you need.
4946 4. Run "make <board>_defconfig" with your new name.
4947 5. Type "make", and you should get a working "u-boot.srec" file
4948 to be installed on your target system.
4949 6. Debug and solve any problems that might arise.
4950 [Of course, this last step is much harder than it sounds.]
4953 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4954 ==============================================================
4956 If you have modified U-Boot sources (for instance added a new board
4957 or support for new devices, a new CPU, etc.) you are expected to
4958 provide feedback to the other developers. The feedback normally takes
4959 the form of a "patch", i. e. a context diff against a certain (latest
4960 official or latest in the git repository) version of U-Boot sources.
4962 But before you submit such a patch, please verify that your modifi-
4963 cation did not break existing code. At least make sure that *ALL* of
4964 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4965 just run the buildman script (tools/buildman/buildman), which will
4966 configure and build U-Boot for ALL supported system. Be warned, this
4967 will take a while. Please see the buildman README, or run 'buildman -H'
4971 See also "U-Boot Porting Guide" below.
4974 Monitor Commands - Overview:
4975 ============================
4977 go - start application at address 'addr'
4978 run - run commands in an environment variable
4979 bootm - boot application image from memory
4980 bootp - boot image via network using BootP/TFTP protocol
4981 bootz - boot zImage from memory
4982 tftpboot- boot image via network using TFTP protocol
4983 and env variables "ipaddr" and "serverip"
4984 (and eventually "gatewayip")
4985 tftpput - upload a file via network using TFTP protocol
4986 rarpboot- boot image via network using RARP/TFTP protocol
4987 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4988 loads - load S-Record file over serial line
4989 loadb - load binary file over serial line (kermit mode)
4991 mm - memory modify (auto-incrementing)
4992 nm - memory modify (constant address)
4993 mw - memory write (fill)
4995 cmp - memory compare
4996 crc32 - checksum calculation
4997 i2c - I2C sub-system
4998 sspi - SPI utility commands
4999 base - print or set address offset
5000 printenv- print environment variables
5001 setenv - set environment variables
5002 saveenv - save environment variables to persistent storage
5003 protect - enable or disable FLASH write protection
5004 erase - erase FLASH memory
5005 flinfo - print FLASH memory information
5006 nand - NAND memory operations (see doc/README.nand)
5007 bdinfo - print Board Info structure
5008 iminfo - print header information for application image
5009 coninfo - print console devices and informations
5010 ide - IDE sub-system
5011 loop - infinite loop on address range
5012 loopw - infinite write loop on address range
5013 mtest - simple RAM test
5014 icache - enable or disable instruction cache
5015 dcache - enable or disable data cache
5016 reset - Perform RESET of the CPU
5017 echo - echo args to console
5018 version - print monitor version
5019 help - print online help
5020 ? - alias for 'help'
5023 Monitor Commands - Detailed Description:
5024 ========================================
5028 For now: just type "help <command>".
5031 Environment Variables:
5032 ======================
5034 U-Boot supports user configuration using Environment Variables which
5035 can be made persistent by saving to Flash memory.
5037 Environment Variables are set using "setenv", printed using
5038 "printenv", and saved to Flash using "saveenv". Using "setenv"
5039 without a value can be used to delete a variable from the
5040 environment. As long as you don't save the environment you are
5041 working with an in-memory copy. In case the Flash area containing the
5042 environment is erased by accident, a default environment is provided.
5044 Some configuration options can be set using Environment Variables.
5046 List of environment variables (most likely not complete):
5048 baudrate - see CONFIG_BAUDRATE
5050 bootdelay - see CONFIG_BOOTDELAY
5052 bootcmd - see CONFIG_BOOTCOMMAND
5054 bootargs - Boot arguments when booting an RTOS image
5056 bootfile - Name of the image to load with TFTP
5058 bootm_low - Memory range available for image processing in the bootm
5059 command can be restricted. This variable is given as
5060 a hexadecimal number and defines lowest address allowed
5061 for use by the bootm command. See also "bootm_size"
5062 environment variable. Address defined by "bootm_low" is
5063 also the base of the initial memory mapping for the Linux
5064 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5067 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5068 This variable is given as a hexadecimal number and it
5069 defines the size of the memory region starting at base
5070 address bootm_low that is accessible by the Linux kernel
5071 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5072 as the default value if it is defined, and bootm_size is
5075 bootm_size - Memory range available for image processing in the bootm
5076 command can be restricted. This variable is given as
5077 a hexadecimal number and defines the size of the region
5078 allowed for use by the bootm command. See also "bootm_low"
5079 environment variable.
5081 updatefile - Location of the software update file on a TFTP server, used
5082 by the automatic software update feature. Please refer to
5083 documentation in doc/README.update for more details.
5085 autoload - if set to "no" (any string beginning with 'n'),
5086 "bootp" will just load perform a lookup of the
5087 configuration from the BOOTP server, but not try to
5088 load any image using TFTP
5090 autostart - if set to "yes", an image loaded using the "bootp",
5091 "rarpboot", "tftpboot" or "diskboot" commands will
5092 be automatically started (by internally calling
5095 If set to "no", a standalone image passed to the
5096 "bootm" command will be copied to the load address
5097 (and eventually uncompressed), but NOT be started.
5098 This can be used to load and uncompress arbitrary
5101 fdt_high - if set this restricts the maximum address that the
5102 flattened device tree will be copied into upon boot.
5103 For example, if you have a system with 1 GB memory
5104 at physical address 0x10000000, while Linux kernel
5105 only recognizes the first 704 MB as low memory, you
5106 may need to set fdt_high as 0x3C000000 to have the
5107 device tree blob be copied to the maximum address
5108 of the 704 MB low memory, so that Linux kernel can
5109 access it during the boot procedure.
5111 If this is set to the special value 0xFFFFFFFF then
5112 the fdt will not be copied at all on boot. For this
5113 to work it must reside in writable memory, have
5114 sufficient padding on the end of it for u-boot to
5115 add the information it needs into it, and the memory
5116 must be accessible by the kernel.
5118 fdtcontroladdr- if set this is the address of the control flattened
5119 device tree used by U-Boot when CONFIG_OF_CONTROL is
5122 i2cfast - (PPC405GP|PPC405EP only)
5123 if set to 'y' configures Linux I2C driver for fast
5124 mode (400kHZ). This environment variable is used in
5125 initialization code. So, for changes to be effective
5126 it must be saved and board must be reset.
5128 initrd_high - restrict positioning of initrd images:
5129 If this variable is not set, initrd images will be
5130 copied to the highest possible address in RAM; this
5131 is usually what you want since it allows for
5132 maximum initrd size. If for some reason you want to
5133 make sure that the initrd image is loaded below the
5134 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5135 variable to a value of "no" or "off" or "0".
5136 Alternatively, you can set it to a maximum upper
5137 address to use (U-Boot will still check that it
5138 does not overwrite the U-Boot stack and data).
5140 For instance, when you have a system with 16 MB
5141 RAM, and want to reserve 4 MB from use by Linux,
5142 you can do this by adding "mem=12M" to the value of
5143 the "bootargs" variable. However, now you must make
5144 sure that the initrd image is placed in the first
5145 12 MB as well - this can be done with
5147 setenv initrd_high 00c00000
5149 If you set initrd_high to 0xFFFFFFFF, this is an
5150 indication to U-Boot that all addresses are legal
5151 for the Linux kernel, including addresses in flash
5152 memory. In this case U-Boot will NOT COPY the
5153 ramdisk at all. This may be useful to reduce the
5154 boot time on your system, but requires that this
5155 feature is supported by your Linux kernel.
5157 ipaddr - IP address; needed for tftpboot command
5159 loadaddr - Default load address for commands like "bootp",
5160 "rarpboot", "tftpboot", "loadb" or "diskboot"
5162 loads_echo - see CONFIG_LOADS_ECHO
5164 serverip - TFTP server IP address; needed for tftpboot command
5166 bootretry - see CONFIG_BOOT_RETRY_TIME
5168 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5170 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5172 ethprime - controls which interface is used first.
5174 ethact - controls which interface is currently active.
5175 For example you can do the following
5177 => setenv ethact FEC
5178 => ping 192.168.0.1 # traffic sent on FEC
5179 => setenv ethact SCC
5180 => ping 10.0.0.1 # traffic sent on SCC
5182 ethrotate - When set to "no" U-Boot does not go through all
5183 available network interfaces.
5184 It just stays at the currently selected interface.
5186 netretry - When set to "no" each network operation will
5187 either succeed or fail without retrying.
5188 When set to "once" the network operation will
5189 fail when all the available network interfaces
5190 are tried once without success.
5191 Useful on scripts which control the retry operation
5194 npe_ucode - set load address for the NPE microcode
5196 silent_linux - If set then Linux will be told to boot silently, by
5197 changing the console to be empty. If "yes" it will be
5198 made silent. If "no" it will not be made silent. If
5199 unset, then it will be made silent if the U-Boot console
5202 tftpsrcp - If this is set, the value is used for TFTP's
5205 tftpdstp - If this is set, the value is used for TFTP's UDP
5206 destination port instead of the Well Know Port 69.
5208 tftpblocksize - Block size to use for TFTP transfers; if not set,
5209 we use the TFTP server's default block size
5211 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5212 seconds, minimum value is 1000 = 1 second). Defines
5213 when a packet is considered to be lost so it has to
5214 be retransmitted. The default is 5000 = 5 seconds.
5215 Lowering this value may make downloads succeed
5216 faster in networks with high packet loss rates or
5217 with unreliable TFTP servers.
5219 tftptimeoutcountmax - maximum count of TFTP timeouts (no
5220 unit, minimum value = 0). Defines how many timeouts
5221 can happen during a single file transfer before that
5222 transfer is aborted. The default is 10, and 0 means
5223 'no timeouts allowed'. Increasing this value may help
5224 downloads succeed with high packet loss rates, or with
5225 unreliable TFTP servers or client hardware.
5227 vlan - When set to a value < 4095 the traffic over
5228 Ethernet is encapsulated/received over 802.1q
5231 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
5232 Unsigned value, in milliseconds. If not set, the period will
5233 be either the default (28000), or a value based on
5234 CONFIG_NET_RETRY_COUNT, if defined. This value has
5235 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
5237 The following image location variables contain the location of images
5238 used in booting. The "Image" column gives the role of the image and is
5239 not an environment variable name. The other columns are environment
5240 variable names. "File Name" gives the name of the file on a TFTP
5241 server, "RAM Address" gives the location in RAM the image will be
5242 loaded to, and "Flash Location" gives the image's address in NOR
5243 flash or offset in NAND flash.
5245 *Note* - these variables don't have to be defined for all boards, some
5246 boards currently use other variables for these purposes, and some
5247 boards use these variables for other purposes.
5249 Image File Name RAM Address Flash Location
5250 ----- --------- ----------- --------------
5251 u-boot u-boot u-boot_addr_r u-boot_addr
5252 Linux kernel bootfile kernel_addr_r kernel_addr
5253 device tree blob fdtfile fdt_addr_r fdt_addr
5254 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5256 The following environment variables may be used and automatically
5257 updated by the network boot commands ("bootp" and "rarpboot"),
5258 depending the information provided by your boot server:
5260 bootfile - see above
5261 dnsip - IP address of your Domain Name Server
5262 dnsip2 - IP address of your secondary Domain Name Server
5263 gatewayip - IP address of the Gateway (Router) to use
5264 hostname - Target hostname
5266 netmask - Subnet Mask
5267 rootpath - Pathname of the root filesystem on the NFS server
5268 serverip - see above
5271 There are two special Environment Variables:
5273 serial# - contains hardware identification information such
5274 as type string and/or serial number
5275 ethaddr - Ethernet address
5277 These variables can be set only once (usually during manufacturing of
5278 the board). U-Boot refuses to delete or overwrite these variables
5279 once they have been set once.
5282 Further special Environment Variables:
5284 ver - Contains the U-Boot version string as printed
5285 with the "version" command. This variable is
5286 readonly (see CONFIG_VERSION_VARIABLE).
5289 Please note that changes to some configuration parameters may take
5290 only effect after the next boot (yes, that's just like Windoze :-).
5293 Callback functions for environment variables:
5294 ---------------------------------------------
5296 For some environment variables, the behavior of u-boot needs to change
5297 when their values are changed. This functionality allows functions to
5298 be associated with arbitrary variables. On creation, overwrite, or
5299 deletion, the callback will provide the opportunity for some side
5300 effect to happen or for the change to be rejected.
5302 The callbacks are named and associated with a function using the
5303 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5305 These callbacks are associated with variables in one of two ways. The
5306 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5307 in the board configuration to a string that defines a list of
5308 associations. The list must be in the following format:
5310 entry = variable_name[:callback_name]
5313 If the callback name is not specified, then the callback is deleted.
5314 Spaces are also allowed anywhere in the list.
5316 Callbacks can also be associated by defining the ".callbacks" variable
5317 with the same list format above. Any association in ".callbacks" will
5318 override any association in the static list. You can define
5319 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5320 ".callbacks" environment variable in the default or embedded environment.
5322 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
5323 regular expression. This allows multiple variables to be connected to
5324 the same callback without explicitly listing them all out.
5327 Command Line Parsing:
5328 =====================
5330 There are two different command line parsers available with U-Boot:
5331 the old "simple" one, and the much more powerful "hush" shell:
5333 Old, simple command line parser:
5334 --------------------------------
5336 - supports environment variables (through setenv / saveenv commands)
5337 - several commands on one line, separated by ';'
5338 - variable substitution using "... ${name} ..." syntax
5339 - special characters ('$', ';') can be escaped by prefixing with '\',
5341 setenv bootcmd bootm \${address}
5342 - You can also escape text by enclosing in single apostrophes, for example:
5343 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5348 - similar to Bourne shell, with control structures like
5349 if...then...else...fi, for...do...done; while...do...done,
5350 until...do...done, ...
5351 - supports environment ("global") variables (through setenv / saveenv
5352 commands) and local shell variables (through standard shell syntax
5353 "name=value"); only environment variables can be used with "run"
5359 (1) If a command line (or an environment variable executed by a "run"
5360 command) contains several commands separated by semicolon, and
5361 one of these commands fails, then the remaining commands will be
5364 (2) If you execute several variables with one call to run (i. e.
5365 calling run with a list of variables as arguments), any failing
5366 command will cause "run" to terminate, i. e. the remaining
5367 variables are not executed.
5369 Note for Redundant Ethernet Interfaces:
5370 =======================================
5372 Some boards come with redundant Ethernet interfaces; U-Boot supports
5373 such configurations and is capable of automatic selection of a
5374 "working" interface when needed. MAC assignment works as follows:
5376 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5377 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5378 "eth1addr" (=>eth1), "eth2addr", ...
5380 If the network interface stores some valid MAC address (for instance
5381 in SROM), this is used as default address if there is NO correspon-
5382 ding setting in the environment; if the corresponding environment
5383 variable is set, this overrides the settings in the card; that means:
5385 o If the SROM has a valid MAC address, and there is no address in the
5386 environment, the SROM's address is used.
5388 o If there is no valid address in the SROM, and a definition in the
5389 environment exists, then the value from the environment variable is
5392 o If both the SROM and the environment contain a MAC address, and
5393 both addresses are the same, this MAC address is used.
5395 o If both the SROM and the environment contain a MAC address, and the
5396 addresses differ, the value from the environment is used and a
5399 o If neither SROM nor the environment contain a MAC address, an error
5400 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
5401 a random, locally-assigned MAC is used.
5403 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5404 will be programmed into hardware as part of the initialization process. This
5405 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5406 The naming convention is as follows:
5407 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5412 U-Boot is capable of booting (and performing other auxiliary operations on)
5413 images in two formats:
5415 New uImage format (FIT)
5416 -----------------------
5418 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5419 to Flattened Device Tree). It allows the use of images with multiple
5420 components (several kernels, ramdisks, etc.), with contents protected by
5421 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5427 Old image format is based on binary files which can be basically anything,
5428 preceded by a special header; see the definitions in include/image.h for
5429 details; basically, the header defines the following image properties:
5431 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5432 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5433 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5434 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5436 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5437 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5438 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5439 * Compression Type (uncompressed, gzip, bzip2)
5445 The header is marked by a special Magic Number, and both the header
5446 and the data portions of the image are secured against corruption by
5453 Although U-Boot should support any OS or standalone application
5454 easily, the main focus has always been on Linux during the design of
5457 U-Boot includes many features that so far have been part of some
5458 special "boot loader" code within the Linux kernel. Also, any
5459 "initrd" images to be used are no longer part of one big Linux image;
5460 instead, kernel and "initrd" are separate images. This implementation
5461 serves several purposes:
5463 - the same features can be used for other OS or standalone
5464 applications (for instance: using compressed images to reduce the
5465 Flash memory footprint)
5467 - it becomes much easier to port new Linux kernel versions because
5468 lots of low-level, hardware dependent stuff are done by U-Boot
5470 - the same Linux kernel image can now be used with different "initrd"
5471 images; of course this also means that different kernel images can
5472 be run with the same "initrd". This makes testing easier (you don't
5473 have to build a new "zImage.initrd" Linux image when you just
5474 change a file in your "initrd"). Also, a field-upgrade of the
5475 software is easier now.
5481 Porting Linux to U-Boot based systems:
5482 ---------------------------------------
5484 U-Boot cannot save you from doing all the necessary modifications to
5485 configure the Linux device drivers for use with your target hardware
5486 (no, we don't intend to provide a full virtual machine interface to
5489 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5491 Just make sure your machine specific header file (for instance
5492 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5493 Information structure as we define in include/asm-<arch>/u-boot.h,
5494 and make sure that your definition of IMAP_ADDR uses the same value
5495 as your U-Boot configuration in CONFIG_SYS_IMMR.
5497 Note that U-Boot now has a driver model, a unified model for drivers.
5498 If you are adding a new driver, plumb it into driver model. If there
5499 is no uclass available, you are encouraged to create one. See
5503 Configuring the Linux kernel:
5504 -----------------------------
5506 No specific requirements for U-Boot. Make sure you have some root
5507 device (initial ramdisk, NFS) for your target system.
5510 Building a Linux Image:
5511 -----------------------
5513 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5514 not used. If you use recent kernel source, a new build target
5515 "uImage" will exist which automatically builds an image usable by
5516 U-Boot. Most older kernels also have support for a "pImage" target,
5517 which was introduced for our predecessor project PPCBoot and uses a
5518 100% compatible format.
5522 make TQM850L_defconfig
5527 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5528 encapsulate a compressed Linux kernel image with header information,
5529 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5531 * build a standard "vmlinux" kernel image (in ELF binary format):
5533 * convert the kernel into a raw binary image:
5535 ${CROSS_COMPILE}-objcopy -O binary \
5536 -R .note -R .comment \
5537 -S vmlinux linux.bin
5539 * compress the binary image:
5543 * package compressed binary image for U-Boot:
5545 mkimage -A ppc -O linux -T kernel -C gzip \
5546 -a 0 -e 0 -n "Linux Kernel Image" \
5547 -d linux.bin.gz uImage
5550 The "mkimage" tool can also be used to create ramdisk images for use
5551 with U-Boot, either separated from the Linux kernel image, or
5552 combined into one file. "mkimage" encapsulates the images with a 64
5553 byte header containing information about target architecture,
5554 operating system, image type, compression method, entry points, time
5555 stamp, CRC32 checksums, etc.
5557 "mkimage" can be called in two ways: to verify existing images and
5558 print the header information, or to build new images.
5560 In the first form (with "-l" option) mkimage lists the information
5561 contained in the header of an existing U-Boot image; this includes
5562 checksum verification:
5564 tools/mkimage -l image
5565 -l ==> list image header information
5567 The second form (with "-d" option) is used to build a U-Boot image
5568 from a "data file" which is used as image payload:
5570 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5571 -n name -d data_file image
5572 -A ==> set architecture to 'arch'
5573 -O ==> set operating system to 'os'
5574 -T ==> set image type to 'type'
5575 -C ==> set compression type 'comp'
5576 -a ==> set load address to 'addr' (hex)
5577 -e ==> set entry point to 'ep' (hex)
5578 -n ==> set image name to 'name'
5579 -d ==> use image data from 'datafile'
5581 Right now, all Linux kernels for PowerPC systems use the same load
5582 address (0x00000000), but the entry point address depends on the
5585 - 2.2.x kernels have the entry point at 0x0000000C,
5586 - 2.3.x and later kernels have the entry point at 0x00000000.
5588 So a typical call to build a U-Boot image would read:
5590 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5591 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5592 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5593 > examples/uImage.TQM850L
5594 Image Name: 2.4.4 kernel for TQM850L
5595 Created: Wed Jul 19 02:34:59 2000
5596 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5597 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5598 Load Address: 0x00000000
5599 Entry Point: 0x00000000
5601 To verify the contents of the image (or check for corruption):
5603 -> tools/mkimage -l examples/uImage.TQM850L
5604 Image Name: 2.4.4 kernel for TQM850L
5605 Created: Wed Jul 19 02:34:59 2000
5606 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5607 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5608 Load Address: 0x00000000
5609 Entry Point: 0x00000000
5611 NOTE: for embedded systems where boot time is critical you can trade
5612 speed for memory and install an UNCOMPRESSED image instead: this
5613 needs more space in Flash, but boots much faster since it does not
5614 need to be uncompressed:
5616 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5617 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5618 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5619 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5620 > examples/uImage.TQM850L-uncompressed
5621 Image Name: 2.4.4 kernel for TQM850L
5622 Created: Wed Jul 19 02:34:59 2000
5623 Image Type: PowerPC Linux Kernel Image (uncompressed)
5624 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5625 Load Address: 0x00000000
5626 Entry Point: 0x00000000
5629 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5630 when your kernel is intended to use an initial ramdisk:
5632 -> tools/mkimage -n 'Simple Ramdisk Image' \
5633 > -A ppc -O linux -T ramdisk -C gzip \
5634 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5635 Image Name: Simple Ramdisk Image
5636 Created: Wed Jan 12 14:01:50 2000
5637 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5638 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5639 Load Address: 0x00000000
5640 Entry Point: 0x00000000
5642 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5643 option performs the converse operation of the mkimage's second form (the "-d"
5644 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5647 tools/dumpimage -i image -T type -p position data_file
5648 -i ==> extract from the 'image' a specific 'data_file'
5649 -T ==> set image type to 'type'
5650 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
5653 Installing a Linux Image:
5654 -------------------------
5656 To downloading a U-Boot image over the serial (console) interface,
5657 you must convert the image to S-Record format:
5659 objcopy -I binary -O srec examples/image examples/image.srec
5661 The 'objcopy' does not understand the information in the U-Boot
5662 image header, so the resulting S-Record file will be relative to
5663 address 0x00000000. To load it to a given address, you need to
5664 specify the target address as 'offset' parameter with the 'loads'
5667 Example: install the image to address 0x40100000 (which on the
5668 TQM8xxL is in the first Flash bank):
5670 => erase 40100000 401FFFFF
5676 ## Ready for S-Record download ...
5677 ~>examples/image.srec
5678 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5680 15989 15990 15991 15992
5681 [file transfer complete]
5683 ## Start Addr = 0x00000000
5686 You can check the success of the download using the 'iminfo' command;
5687 this includes a checksum verification so you can be sure no data
5688 corruption happened:
5692 ## Checking Image at 40100000 ...
5693 Image Name: 2.2.13 for initrd on TQM850L
5694 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5695 Data Size: 335725 Bytes = 327 kB = 0 MB
5696 Load Address: 00000000
5697 Entry Point: 0000000c
5698 Verifying Checksum ... OK
5704 The "bootm" command is used to boot an application that is stored in
5705 memory (RAM or Flash). In case of a Linux kernel image, the contents
5706 of the "bootargs" environment variable is passed to the kernel as
5707 parameters. You can check and modify this variable using the
5708 "printenv" and "setenv" commands:
5711 => printenv bootargs
5712 bootargs=root=/dev/ram
5714 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5716 => printenv bootargs
5717 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5720 ## Booting Linux kernel at 40020000 ...
5721 Image Name: 2.2.13 for NFS on TQM850L
5722 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5723 Data Size: 381681 Bytes = 372 kB = 0 MB
5724 Load Address: 00000000
5725 Entry Point: 0000000c
5726 Verifying Checksum ... OK
5727 Uncompressing Kernel Image ... OK
5728 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
5729 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5730 time_init: decrementer frequency = 187500000/60
5731 Calibrating delay loop... 49.77 BogoMIPS
5732 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5735 If you want to boot a Linux kernel with initial RAM disk, you pass
5736 the memory addresses of both the kernel and the initrd image (PPBCOOT
5737 format!) to the "bootm" command:
5739 => imi 40100000 40200000
5741 ## Checking Image at 40100000 ...
5742 Image Name: 2.2.13 for initrd on TQM850L
5743 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5744 Data Size: 335725 Bytes = 327 kB = 0 MB
5745 Load Address: 00000000
5746 Entry Point: 0000000c
5747 Verifying Checksum ... OK
5749 ## Checking Image at 40200000 ...
5750 Image Name: Simple Ramdisk Image
5751 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5752 Data Size: 566530 Bytes = 553 kB = 0 MB
5753 Load Address: 00000000
5754 Entry Point: 00000000
5755 Verifying Checksum ... OK
5757 => bootm 40100000 40200000
5758 ## Booting Linux kernel at 40100000 ...
5759 Image Name: 2.2.13 for initrd on TQM850L
5760 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5761 Data Size: 335725 Bytes = 327 kB = 0 MB
5762 Load Address: 00000000
5763 Entry Point: 0000000c
5764 Verifying Checksum ... OK
5765 Uncompressing Kernel Image ... OK
5766 ## Loading RAMDisk Image at 40200000 ...
5767 Image Name: Simple Ramdisk Image
5768 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5769 Data Size: 566530 Bytes = 553 kB = 0 MB
5770 Load Address: 00000000
5771 Entry Point: 00000000
5772 Verifying Checksum ... OK
5773 Loading Ramdisk ... OK
5774 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
5775 Boot arguments: root=/dev/ram
5776 time_init: decrementer frequency = 187500000/60
5777 Calibrating delay loop... 49.77 BogoMIPS
5779 RAMDISK: Compressed image found at block 0
5780 VFS: Mounted root (ext2 filesystem).
5784 Boot Linux and pass a flat device tree:
5787 First, U-Boot must be compiled with the appropriate defines. See the section
5788 titled "Linux Kernel Interface" above for a more in depth explanation. The
5789 following is an example of how to start a kernel and pass an updated
5795 oft=oftrees/mpc8540ads.dtb
5796 => tftp $oftaddr $oft
5797 Speed: 1000, full duplex
5799 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5800 Filename 'oftrees/mpc8540ads.dtb'.
5801 Load address: 0x300000
5804 Bytes transferred = 4106 (100a hex)
5805 => tftp $loadaddr $bootfile
5806 Speed: 1000, full duplex
5808 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5810 Load address: 0x200000
5811 Loading:############
5813 Bytes transferred = 1029407 (fb51f hex)
5818 => bootm $loadaddr - $oftaddr
5819 ## Booting image at 00200000 ...
5820 Image Name: Linux-2.6.17-dirty
5821 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5822 Data Size: 1029343 Bytes = 1005.2 kB
5823 Load Address: 00000000
5824 Entry Point: 00000000
5825 Verifying Checksum ... OK
5826 Uncompressing Kernel Image ... OK
5827 Booting using flat device tree at 0x300000
5828 Using MPC85xx ADS machine description
5829 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5833 More About U-Boot Image Types:
5834 ------------------------------
5836 U-Boot supports the following image types:
5838 "Standalone Programs" are directly runnable in the environment
5839 provided by U-Boot; it is expected that (if they behave
5840 well) you can continue to work in U-Boot after return from
5841 the Standalone Program.
5842 "OS Kernel Images" are usually images of some Embedded OS which
5843 will take over control completely. Usually these programs
5844 will install their own set of exception handlers, device
5845 drivers, set up the MMU, etc. - this means, that you cannot
5846 expect to re-enter U-Boot except by resetting the CPU.
5847 "RAMDisk Images" are more or less just data blocks, and their
5848 parameters (address, size) are passed to an OS kernel that is
5850 "Multi-File Images" contain several images, typically an OS
5851 (Linux) kernel image and one or more data images like
5852 RAMDisks. This construct is useful for instance when you want
5853 to boot over the network using BOOTP etc., where the boot
5854 server provides just a single image file, but you want to get
5855 for instance an OS kernel and a RAMDisk image.
5857 "Multi-File Images" start with a list of image sizes, each
5858 image size (in bytes) specified by an "uint32_t" in network
5859 byte order. This list is terminated by an "(uint32_t)0".
5860 Immediately after the terminating 0 follow the images, one by
5861 one, all aligned on "uint32_t" boundaries (size rounded up to
5862 a multiple of 4 bytes).
5864 "Firmware Images" are binary images containing firmware (like
5865 U-Boot or FPGA images) which usually will be programmed to
5868 "Script files" are command sequences that will be executed by
5869 U-Boot's command interpreter; this feature is especially
5870 useful when you configure U-Boot to use a real shell (hush)
5871 as command interpreter.
5873 Booting the Linux zImage:
5874 -------------------------
5876 On some platforms, it's possible to boot Linux zImage. This is done
5877 using the "bootz" command. The syntax of "bootz" command is the same
5878 as the syntax of "bootm" command.
5880 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5881 kernel with raw initrd images. The syntax is slightly different, the
5882 address of the initrd must be augmented by it's size, in the following
5883 format: "<initrd addres>:<initrd size>".
5889 One of the features of U-Boot is that you can dynamically load and
5890 run "standalone" applications, which can use some resources of
5891 U-Boot like console I/O functions or interrupt services.
5893 Two simple examples are included with the sources:
5898 'examples/hello_world.c' contains a small "Hello World" Demo
5899 application; it is automatically compiled when you build U-Boot.
5900 It's configured to run at address 0x00040004, so you can play with it
5904 ## Ready for S-Record download ...
5905 ~>examples/hello_world.srec
5906 1 2 3 4 5 6 7 8 9 10 11 ...
5907 [file transfer complete]
5909 ## Start Addr = 0x00040004
5911 => go 40004 Hello World! This is a test.
5912 ## Starting application at 0x00040004 ...
5923 Hit any key to exit ...
5925 ## Application terminated, rc = 0x0
5927 Another example, which demonstrates how to register a CPM interrupt
5928 handler with the U-Boot code, can be found in 'examples/timer.c'.
5929 Here, a CPM timer is set up to generate an interrupt every second.
5930 The interrupt service routine is trivial, just printing a '.'
5931 character, but this is just a demo program. The application can be
5932 controlled by the following keys:
5934 ? - print current values og the CPM Timer registers
5935 b - enable interrupts and start timer
5936 e - stop timer and disable interrupts
5937 q - quit application
5940 ## Ready for S-Record download ...
5941 ~>examples/timer.srec
5942 1 2 3 4 5 6 7 8 9 10 11 ...
5943 [file transfer complete]
5945 ## Start Addr = 0x00040004
5948 ## Starting application at 0x00040004 ...
5951 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5954 [q, b, e, ?] Set interval 1000000 us
5957 [q, b, e, ?] ........
5958 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5961 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5964 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5967 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5969 [q, b, e, ?] ...Stopping timer
5971 [q, b, e, ?] ## Application terminated, rc = 0x0
5977 Over time, many people have reported problems when trying to use the
5978 "minicom" terminal emulation program for serial download. I (wd)
5979 consider minicom to be broken, and recommend not to use it. Under
5980 Unix, I recommend to use C-Kermit for general purpose use (and
5981 especially for kermit binary protocol download ("loadb" command), and
5982 use "cu" for S-Record download ("loads" command). See
5983 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5984 for help with kermit.
5987 Nevertheless, if you absolutely want to use it try adding this
5988 configuration to your "File transfer protocols" section:
5990 Name Program Name U/D FullScr IO-Red. Multi
5991 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5992 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5998 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5999 (build U-Boot) and target system (boots NetBSD/mpc8xx).
6001 Building requires a cross environment; it is known to work on
6002 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
6003 need gmake since the Makefiles are not compatible with BSD make).
6004 Note that the cross-powerpc package does not install include files;
6005 attempting to build U-Boot will fail because <machine/ansi.h> is
6006 missing. This file has to be installed and patched manually:
6008 # cd /usr/pkg/cross/powerpc-netbsd/include
6010 # ln -s powerpc machine
6011 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6012 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6014 Native builds *don't* work due to incompatibilities between native
6015 and U-Boot include files.
6017 Booting assumes that (the first part of) the image booted is a
6018 stage-2 loader which in turn loads and then invokes the kernel
6019 proper. Loader sources will eventually appear in the NetBSD source
6020 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6021 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6024 Implementation Internals:
6025 =========================
6027 The following is not intended to be a complete description of every
6028 implementation detail. However, it should help to understand the
6029 inner workings of U-Boot and make it easier to port it to custom
6033 Initial Stack, Global Data:
6034 ---------------------------
6036 The implementation of U-Boot is complicated by the fact that U-Boot
6037 starts running out of ROM (flash memory), usually without access to
6038 system RAM (because the memory controller is not initialized yet).
6039 This means that we don't have writable Data or BSS segments, and BSS
6040 is not initialized as zero. To be able to get a C environment working
6041 at all, we have to allocate at least a minimal stack. Implementation
6042 options for this are defined and restricted by the CPU used: Some CPU
6043 models provide on-chip memory (like the IMMR area on MPC8xx and
6044 MPC826x processors), on others (parts of) the data cache can be
6045 locked as (mis-) used as memory, etc.
6047 Chris Hallinan posted a good summary of these issues to the
6048 U-Boot mailing list:
6050 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6051 From: "Chris Hallinan" <clh@net1plus.com>
6052 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6055 Correct me if I'm wrong, folks, but the way I understand it
6056 is this: Using DCACHE as initial RAM for Stack, etc, does not
6057 require any physical RAM backing up the cache. The cleverness
6058 is that the cache is being used as a temporary supply of
6059 necessary storage before the SDRAM controller is setup. It's
6060 beyond the scope of this list to explain the details, but you
6061 can see how this works by studying the cache architecture and
6062 operation in the architecture and processor-specific manuals.
6064 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6065 is another option for the system designer to use as an
6066 initial stack/RAM area prior to SDRAM being available. Either
6067 option should work for you. Using CS 4 should be fine if your
6068 board designers haven't used it for something that would
6069 cause you grief during the initial boot! It is frequently not
6072 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6073 with your processor/board/system design. The default value
6074 you will find in any recent u-boot distribution in
6075 walnut.h should work for you. I'd set it to a value larger
6076 than your SDRAM module. If you have a 64MB SDRAM module, set
6077 it above 400_0000. Just make sure your board has no resources
6078 that are supposed to respond to that address! That code in
6079 start.S has been around a while and should work as is when
6080 you get the config right.
6085 It is essential to remember this, since it has some impact on the C
6086 code for the initialization procedures:
6088 * Initialized global data (data segment) is read-only. Do not attempt
6091 * Do not use any uninitialized global data (or implicitly initialized
6092 as zero data - BSS segment) at all - this is undefined, initiali-
6093 zation is performed later (when relocating to RAM).
6095 * Stack space is very limited. Avoid big data buffers or things like
6098 Having only the stack as writable memory limits means we cannot use
6099 normal global data to share information between the code. But it
6100 turned out that the implementation of U-Boot can be greatly
6101 simplified by making a global data structure (gd_t) available to all
6102 functions. We could pass a pointer to this data as argument to _all_
6103 functions, but this would bloat the code. Instead we use a feature of
6104 the GCC compiler (Global Register Variables) to share the data: we
6105 place a pointer (gd) to the global data into a register which we
6106 reserve for this purpose.
6108 When choosing a register for such a purpose we are restricted by the
6109 relevant (E)ABI specifications for the current architecture, and by
6110 GCC's implementation.
6112 For PowerPC, the following registers have specific use:
6114 R2: reserved for system use
6115 R3-R4: parameter passing and return values
6116 R5-R10: parameter passing
6117 R13: small data area pointer
6121 (U-Boot also uses R12 as internal GOT pointer. r12
6122 is a volatile register so r12 needs to be reset when
6123 going back and forth between asm and C)
6125 ==> U-Boot will use R2 to hold a pointer to the global data
6127 Note: on PPC, we could use a static initializer (since the
6128 address of the global data structure is known at compile time),
6129 but it turned out that reserving a register results in somewhat
6130 smaller code - although the code savings are not that big (on
6131 average for all boards 752 bytes for the whole U-Boot image,
6132 624 text + 127 data).
6134 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6135 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6137 ==> U-Boot will use P3 to hold a pointer to the global data
6139 On ARM, the following registers are used:
6141 R0: function argument word/integer result
6142 R1-R3: function argument word
6143 R9: platform specific
6144 R10: stack limit (used only if stack checking is enabled)
6145 R11: argument (frame) pointer
6146 R12: temporary workspace
6149 R15: program counter
6151 ==> U-Boot will use R9 to hold a pointer to the global data
6153 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6155 On Nios II, the ABI is documented here:
6156 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6158 ==> U-Boot will use gp to hold a pointer to the global data
6160 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6161 to access small data sections, so gp is free.
6163 On NDS32, the following registers are used:
6165 R0-R1: argument/return
6167 R15: temporary register for assembler
6168 R16: trampoline register
6169 R28: frame pointer (FP)
6170 R29: global pointer (GP)
6171 R30: link register (LP)
6172 R31: stack pointer (SP)
6173 PC: program counter (PC)
6175 ==> U-Boot will use R10 to hold a pointer to the global data
6177 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6178 or current versions of GCC may "optimize" the code too much.
6183 U-Boot runs in system state and uses physical addresses, i.e. the
6184 MMU is not used either for address mapping nor for memory protection.
6186 The available memory is mapped to fixed addresses using the memory
6187 controller. In this process, a contiguous block is formed for each
6188 memory type (Flash, SDRAM, SRAM), even when it consists of several
6189 physical memory banks.
6191 U-Boot is installed in the first 128 kB of the first Flash bank (on
6192 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6193 booting and sizing and initializing DRAM, the code relocates itself
6194 to the upper end of DRAM. Immediately below the U-Boot code some
6195 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6196 configuration setting]. Below that, a structure with global Board
6197 Info data is placed, followed by the stack (growing downward).
6199 Additionally, some exception handler code is copied to the low 8 kB
6200 of DRAM (0x00000000 ... 0x00001FFF).
6202 So a typical memory configuration with 16 MB of DRAM could look like
6205 0x0000 0000 Exception Vector code
6208 0x0000 2000 Free for Application Use
6214 0x00FB FF20 Monitor Stack (Growing downward)
6215 0x00FB FFAC Board Info Data and permanent copy of global data
6216 0x00FC 0000 Malloc Arena
6219 0x00FE 0000 RAM Copy of Monitor Code
6220 ... eventually: LCD or video framebuffer
6221 ... eventually: pRAM (Protected RAM - unchanged by reset)
6222 0x00FF FFFF [End of RAM]
6225 System Initialization:
6226 ----------------------
6228 In the reset configuration, U-Boot starts at the reset entry point
6229 (on most PowerPC systems at address 0x00000100). Because of the reset
6230 configuration for CS0# this is a mirror of the on board Flash memory.
6231 To be able to re-map memory U-Boot then jumps to its link address.
6232 To be able to implement the initialization code in C, a (small!)
6233 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6234 which provide such a feature like MPC8xx or MPC8260), or in a locked
6235 part of the data cache. After that, U-Boot initializes the CPU core,
6236 the caches and the SIU.
6238 Next, all (potentially) available memory banks are mapped using a
6239 preliminary mapping. For example, we put them on 512 MB boundaries
6240 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6241 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6242 programmed for SDRAM access. Using the temporary configuration, a
6243 simple memory test is run that determines the size of the SDRAM
6246 When there is more than one SDRAM bank, and the banks are of
6247 different size, the largest is mapped first. For equal size, the first
6248 bank (CS2#) is mapped first. The first mapping is always for address
6249 0x00000000, with any additional banks following immediately to create
6250 contiguous memory starting from 0.
6252 Then, the monitor installs itself at the upper end of the SDRAM area
6253 and allocates memory for use by malloc() and for the global Board
6254 Info data; also, the exception vector code is copied to the low RAM
6255 pages, and the final stack is set up.
6257 Only after this relocation will you have a "normal" C environment;
6258 until that you are restricted in several ways, mostly because you are
6259 running from ROM, and because the code will have to be relocated to a
6263 U-Boot Porting Guide:
6264 ----------------------
6266 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6270 int main(int argc, char *argv[])
6272 sighandler_t no_more_time;
6274 signal(SIGALRM, no_more_time);
6275 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6277 if (available_money > available_manpower) {
6278 Pay consultant to port U-Boot;
6282 Download latest U-Boot source;
6284 Subscribe to u-boot mailing list;
6287 email("Hi, I am new to U-Boot, how do I get started?");
6290 Read the README file in the top level directory;
6291 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6292 Read applicable doc/*.README;
6293 Read the source, Luke;
6294 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6297 if (available_money > toLocalCurrency ($2500))
6300 Add a lot of aggravation and time;
6302 if (a similar board exists) { /* hopefully... */
6303 cp -a board/<similar> board/<myboard>
6304 cp include/configs/<similar>.h include/configs/<myboard>.h
6306 Create your own board support subdirectory;
6307 Create your own board include/configs/<myboard>.h file;
6309 Edit new board/<myboard> files
6310 Edit new include/configs/<myboard>.h
6315 Add / modify source code;
6319 email("Hi, I am having problems...");
6321 Send patch file to the U-Boot email list;
6322 if (reasonable critiques)
6323 Incorporate improvements from email list code review;
6325 Defend code as written;
6331 void no_more_time (int sig)
6340 All contributions to U-Boot should conform to the Linux kernel
6341 coding style; see the file "Documentation/CodingStyle" and the script
6342 "scripts/Lindent" in your Linux kernel source directory.
6344 Source files originating from a different project (for example the
6345 MTD subsystem) are generally exempt from these guidelines and are not
6346 reformatted to ease subsequent migration to newer versions of those
6349 Please note that U-Boot is implemented in C (and to some small parts in
6350 Assembler); no C++ is used, so please do not use C++ style comments (//)
6353 Please also stick to the following formatting rules:
6354 - remove any trailing white space
6355 - use TAB characters for indentation and vertical alignment, not spaces
6356 - make sure NOT to use DOS '\r\n' line feeds
6357 - do not add more than 2 consecutive empty lines to source files
6358 - do not add trailing empty lines to source files
6360 Submissions which do not conform to the standards may be returned
6361 with a request to reformat the changes.
6367 Since the number of patches for U-Boot is growing, we need to
6368 establish some rules. Submissions which do not conform to these rules
6369 may be rejected, even when they contain important and valuable stuff.
6371 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6373 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6374 see http://lists.denx.de/mailman/listinfo/u-boot
6376 When you send a patch, please include the following information with
6379 * For bug fixes: a description of the bug and how your patch fixes
6380 this bug. Please try to include a way of demonstrating that the
6381 patch actually fixes something.
6383 * For new features: a description of the feature and your
6386 * A CHANGELOG entry as plaintext (separate from the patch)
6388 * For major contributions, add a MAINTAINERS file with your
6389 information and associated file and directory references.
6391 * When you add support for a new board, don't forget to add a
6392 maintainer e-mail address to the boards.cfg file, too.
6394 * If your patch adds new configuration options, don't forget to
6395 document these in the README file.
6397 * The patch itself. If you are using git (which is *strongly*
6398 recommended) you can easily generate the patch using the
6399 "git format-patch". If you then use "git send-email" to send it to
6400 the U-Boot mailing list, you will avoid most of the common problems
6401 with some other mail clients.
6403 If you cannot use git, use "diff -purN OLD NEW". If your version of
6404 diff does not support these options, then get the latest version of
6407 The current directory when running this command shall be the parent
6408 directory of the U-Boot source tree (i. e. please make sure that
6409 your patch includes sufficient directory information for the
6412 We prefer patches as plain text. MIME attachments are discouraged,
6413 and compressed attachments must not be used.
6415 * If one logical set of modifications affects or creates several
6416 files, all these changes shall be submitted in a SINGLE patch file.
6418 * Changesets that contain different, unrelated modifications shall be
6419 submitted as SEPARATE patches, one patch per changeset.
6424 * Before sending the patch, run the buildman script on your patched
6425 source tree and make sure that no errors or warnings are reported
6426 for any of the boards.
6428 * Keep your modifications to the necessary minimum: A patch
6429 containing several unrelated changes or arbitrary reformats will be
6430 returned with a request to re-formatting / split it.
6432 * If you modify existing code, make sure that your new code does not
6433 add to the memory footprint of the code ;-) Small is beautiful!
6434 When adding new features, these should compile conditionally only
6435 (using #ifdef), and the resulting code with the new feature
6436 disabled must not need more memory than the old code without your
6439 * Remember that there is a size limit of 100 kB per message on the
6440 u-boot mailing list. Bigger patches will be moderated. If they are
6441 reasonable and not too big, they will be acknowledged. But patches
6442 bigger than the size limit should be avoided.