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 and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /cpu CPU specific files
137 /arc700 Files specific to ARC 700 CPUs
138 /lib Architecture specific library files
139 /arm Files generic to ARM architecture
140 /cpu CPU specific files
141 /arm720t Files specific to ARM 720 CPUs
142 /arm920t Files specific to ARM 920 CPUs
143 /at91 Files specific to Atmel AT91RM9200 CPU
144 /imx Files specific to Freescale MC9328 i.MX CPUs
145 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
146 /arm926ejs Files specific to ARM 926 CPUs
147 /arm1136 Files specific to ARM 1136 CPUs
148 /pxa Files specific to Intel XScale PXA CPUs
149 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
150 /lib Architecture specific library files
151 /avr32 Files generic to AVR32 architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /blackfin Files generic to Analog Devices Blackfin architecture
155 /cpu CPU specific files
156 /lib Architecture specific library files
157 /m68k Files generic to m68k architecture
158 /cpu CPU specific files
159 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 /lib Architecture specific library files
165 /microblaze Files generic to microblaze architecture
166 /cpu CPU specific files
167 /lib Architecture specific library files
168 /mips Files generic to MIPS architecture
169 /cpu CPU specific files
170 /mips32 Files specific to MIPS32 CPUs
171 /mips64 Files specific to MIPS64 CPUs
172 /lib Architecture specific library files
173 /nds32 Files generic to NDS32 architecture
174 /cpu CPU specific files
175 /n1213 Files specific to Andes Technology N1213 CPUs
176 /lib Architecture specific library files
177 /nios2 Files generic to Altera NIOS2 architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /openrisc Files generic to OpenRISC architecture
181 /cpu CPU specific files
182 /lib Architecture specific library files
183 /powerpc Files generic to PowerPC architecture
184 /cpu CPU specific files
185 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
186 /mpc5xx Files specific to Freescale MPC5xx CPUs
187 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
188 /mpc8xx Files specific to Freescale MPC8xx CPUs
189 /mpc824x Files specific to Freescale MPC824x CPUs
190 /mpc8260 Files specific to Freescale MPC8260 CPUs
191 /mpc85xx Files specific to Freescale MPC85xx CPUs
192 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
193 /lib Architecture specific library files
194 /sh Files generic to SH architecture
195 /cpu CPU specific files
196 /sh2 Files specific to sh2 CPUs
197 /sh3 Files specific to sh3 CPUs
198 /sh4 Files specific to sh4 CPUs
199 /lib Architecture specific library files
200 /sparc Files generic to SPARC architecture
201 /cpu CPU specific files
202 /leon2 Files specific to Gaisler LEON2 SPARC CPU
203 /leon3 Files specific to Gaisler LEON3 SPARC CPU
204 /lib Architecture specific library files
205 /x86 Files generic to x86 architecture
206 /cpu CPU specific files
207 /lib Architecture specific library files
208 /api Machine/arch independent API for external apps
209 /board Board dependent files
210 /common Misc architecture independent functions
211 /disk Code for disk drive partition handling
212 /doc Documentation (don't expect too much)
213 /drivers Commonly used device drivers
214 /dts Contains Makefile for building internal U-Boot fdt.
215 /examples Example code for standalone applications, etc.
216 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
217 /include Header Files
218 /lib Files generic to all architectures
219 /libfdt Library files to support flattened device trees
220 /lzma Library files to support LZMA decompression
221 /lzo Library files to support LZO decompression
223 /post Power On Self Test
224 /spl Secondary Program Loader framework
225 /tools Tools to build S-Record or U-Boot images, etc.
227 Software Configuration:
228 =======================
230 Configuration is usually done using C preprocessor defines; the
231 rationale behind that is to avoid dead code whenever possible.
233 There are two classes of configuration variables:
235 * Configuration _OPTIONS_:
236 These are selectable by the user and have names beginning with
239 * Configuration _SETTINGS_:
240 These depend on the hardware etc. and should not be meddled with if
241 you don't know what you're doing; they have names beginning with
244 Later we will add a configuration tool - probably similar to or even
245 identical to what's used for the Linux kernel. Right now, we have to
246 do the configuration by hand, which means creating some symbolic
247 links and editing some configuration files. We use the TQM8xxL boards
251 Selection of Processor Architecture and Board Type:
252 ---------------------------------------------------
254 For all supported boards there are ready-to-use default
255 configurations available; just type "make <board_name>_defconfig".
257 Example: For a TQM823L module type:
260 make TQM823L_defconfig
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_defconfig". And also configure the cogent
264 directory according to the instructions in cogent/README.
270 U-Boot can be built natively to run on a Linux host using the 'sandbox'
271 board. This allows feature development which is not board- or architecture-
272 specific to be undertaken on a native platform. The sandbox is also used to
273 run some of U-Boot's tests.
275 See board/sandbox/sandbox/README.sandbox for more details.
278 Configuration Options:
279 ----------------------
281 Configuration depends on the combination of board and CPU type; all
282 such information is kept in a configuration file
283 "include/configs/<board_name>.h".
285 Example: For a TQM823L module, all configuration settings are in
286 "include/configs/TQM823L.h".
289 Many of the options are named exactly as the corresponding Linux
290 kernel configuration options. The intention is to make it easier to
291 build a config tool - later.
294 The following options need to be configured:
296 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
298 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
300 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
301 Define exactly one, e.g. CONFIG_ATSTK1002
303 - CPU Module Type: (if CONFIG_COGENT is defined)
304 Define exactly one of
306 --- FIXME --- not tested yet:
307 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
308 CONFIG_CMA287_23, CONFIG_CMA287_50
310 - Motherboard Type: (if CONFIG_COGENT is defined)
311 Define exactly one of
312 CONFIG_CMA101, CONFIG_CMA102
314 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
315 Define one or more of
318 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
319 Define one or more of
320 CONFIG_LCD_HEARTBEAT - update a character position on
321 the LCD display every second with
324 - Marvell Family Member
325 CONFIG_SYS_MVFS - define it if you want to enable
326 multiple fs option at one time
327 for marvell soc family
329 - MPC824X Family Member (if CONFIG_MPC824X is defined)
330 Define exactly one of
331 CONFIG_MPC8240, CONFIG_MPC8245
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 requred during NOR boot.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 CONFIG_SYS_FSL_DSP_DDR_ADDR
418 This value denotes start offset of DDR memory which is
419 connected exclusively to the DSP cores.
421 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
422 This value denotes start offset of M2 memory
423 which is directly connected to the DSP core.
425 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
426 This value denotes start offset of M3 memory which is directly
427 connected to the DSP core.
429 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
430 This value denotes start offset of DSP CCSR space.
432 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
433 Single Source Clock is clocking mode present in some of FSL SoC's.
434 In this mode, a single differential clock is used to supply
435 clocks to the sysclock, ddrclock and usbclock.
437 CONFIG_SYS_CPC_REINIT_F
438 This CONFIG is defined when the CPC is configured as SRAM at the
439 time of U-boot entry and is required to be re-initialized.
442 Inidcates this SoC supports deep sleep feature. If deep sleep is
443 supported, core will start to execute uboot when wakes up.
445 - Generic CPU options:
446 CONFIG_SYS_GENERIC_GLOBAL_DATA
447 Defines global data is initialized in generic board board_init_f().
448 If this macro is defined, global data is created and cleared in
449 generic board board_init_f(). Without this macro, architecture/board
450 should initialize global data before calling board_init_f().
452 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
454 Defines the endianess of the CPU. Implementation of those
455 values is arch specific.
458 Freescale DDR driver in use. This type of DDR controller is
459 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
462 CONFIG_SYS_FSL_DDR_ADDR
463 Freescale DDR memory-mapped register base.
465 CONFIG_SYS_FSL_DDR_EMU
466 Specify emulator support for DDR. Some DDR features such as
467 deskew training are not available.
469 CONFIG_SYS_FSL_DDRC_GEN1
470 Freescale DDR1 controller.
472 CONFIG_SYS_FSL_DDRC_GEN2
473 Freescale DDR2 controller.
475 CONFIG_SYS_FSL_DDRC_GEN3
476 Freescale DDR3 controller.
478 CONFIG_SYS_FSL_DDRC_GEN4
479 Freescale DDR4 controller.
481 CONFIG_SYS_FSL_DDRC_ARM_GEN3
482 Freescale DDR3 controller for ARM-based SoCs.
485 Board config to use DDR1. It can be enabled for SoCs with
486 Freescale DDR1 or DDR2 controllers, depending on the board
490 Board config to use DDR2. It can be eanbeld for SoCs with
491 Freescale DDR2 or DDR3 controllers, depending on the board
495 Board config to use DDR3. It can be enabled for SoCs with
496 Freescale DDR3 or DDR3L controllers.
499 Board config to use DDR3L. It can be enabled for SoCs with
503 Board config to use DDR4. It can be enabled for SoCs with
506 CONFIG_SYS_FSL_IFC_BE
507 Defines the IFC controller register space as Big Endian
509 CONFIG_SYS_FSL_IFC_LE
510 Defines the IFC controller register space as Little Endian
512 CONFIG_SYS_FSL_PBL_PBI
513 It enables addition of RCW (Power on reset configuration) in built image.
514 Please refer doc/README.pblimage for more details
516 CONFIG_SYS_FSL_PBL_RCW
517 It adds PBI(pre-boot instructions) commands in u-boot build image.
518 PBI commands can be used to configure SoC before it starts the execution.
519 Please refer doc/README.pblimage for more details
522 It adds a target to create boot binary having SPL binary in PBI format
523 concatenated with u-boot binary.
525 CONFIG_SYS_FSL_DDR_BE
526 Defines the DDR controller register space as Big Endian
528 CONFIG_SYS_FSL_DDR_LE
529 Defines the DDR controller register space as Little Endian
531 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
532 Physical address from the view of DDR controllers. It is the
533 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
534 it could be different for ARM SoCs.
536 CONFIG_SYS_FSL_DDR_INTLV_256B
537 DDR controller interleaving on 256-byte. This is a special
538 interleaving mode, handled by Dickens for Freescale layerscape
541 - Intel Monahans options:
542 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
544 Defines the Monahans run mode to oscillator
545 ratio. Valid values are 8, 16, 24, 31. The core
546 frequency is this value multiplied by 13 MHz.
548 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
550 Defines the Monahans turbo mode to oscillator
551 ratio. Valid values are 1 (default if undefined) and
552 2. The core frequency as calculated above is multiplied
556 CONFIG_SYS_INIT_SP_OFFSET
558 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
559 pointer. This is needed for the temporary stack before
562 CONFIG_SYS_MIPS_CACHE_MODE
564 Cache operation mode for the MIPS CPU.
565 See also arch/mips/include/asm/mipsregs.h.
567 CONF_CM_CACHABLE_NO_WA
570 CONF_CM_CACHABLE_NONCOHERENT
574 CONF_CM_CACHABLE_ACCELERATED
576 CONFIG_SYS_XWAY_EBU_BOOTCFG
578 Special option for Lantiq XWAY SoCs for booting from NOR flash.
579 See also arch/mips/cpu/mips32/start.S.
581 CONFIG_XWAY_SWAP_BYTES
583 Enable compilation of tools/xway-swap-bytes needed for Lantiq
584 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
585 be swapped if a flash programmer is used.
588 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
590 Select high exception vectors of the ARM core, e.g., do not
591 clear the V bit of the c1 register of CP15.
593 CONFIG_SYS_THUMB_BUILD
595 Use this flag to build U-Boot using the Thumb instruction
596 set for ARM architectures. Thumb instruction set provides
597 better code density. For ARM architectures that support
598 Thumb2 this flag will result in Thumb2 code generated by
601 CONFIG_ARM_ERRATA_716044
602 CONFIG_ARM_ERRATA_742230
603 CONFIG_ARM_ERRATA_743622
604 CONFIG_ARM_ERRATA_751472
605 CONFIG_ARM_ERRATA_794072
606 CONFIG_ARM_ERRATA_761320
608 If set, the workarounds for these ARM errata are applied early
609 during U-Boot startup. Note that these options force the
610 workarounds to be applied; no CPU-type/version detection
611 exists, unlike the similar options in the Linux kernel. Do not
612 set these options unless they apply!
617 The frequency of the timer returned by get_timer().
618 get_timer() must operate in milliseconds and this CONFIG
619 option must be set to 1000.
621 - Linux Kernel Interface:
624 U-Boot stores all clock information in Hz
625 internally. For binary compatibility with older Linux
626 kernels (which expect the clocks passed in the
627 bd_info data to be in MHz) the environment variable
628 "clocks_in_mhz" can be defined so that U-Boot
629 converts clock data to MHZ before passing it to the
631 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
632 "clocks_in_mhz=1" is automatically included in the
635 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
637 When transferring memsize parameter to linux, some versions
638 expect it to be in bytes, others in MB.
639 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
643 New kernel versions are expecting firmware settings to be
644 passed using flattened device trees (based on open firmware
648 * New libfdt-based support
649 * Adds the "fdt" command
650 * The bootm command automatically updates the fdt
652 OF_CPU - The proper name of the cpus node (only required for
653 MPC512X and MPC5xxx based boards).
654 OF_SOC - The proper name of the soc node (only required for
655 MPC512X and MPC5xxx based boards).
656 OF_TBCLK - The timebase frequency.
657 OF_STDOUT_PATH - The path to the console device
659 boards with QUICC Engines require OF_QE to set UCC MAC
662 CONFIG_OF_BOARD_SETUP
664 Board code has addition modification that it wants to make
665 to the flat device tree before handing it off to the kernel
669 This define fills in the correct boot CPU in the boot
670 param header, the default value is zero if undefined.
674 U-Boot can detect if an IDE device is present or not.
675 If not, and this new config option is activated, U-Boot
676 removes the ATA node from the DTS before booting Linux,
677 so the Linux IDE driver does not probe the device and
678 crash. This is needed for buggy hardware (uc101) where
679 no pull down resistor is connected to the signal IDE5V_DD7.
681 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
683 This setting is mandatory for all boards that have only one
684 machine type and must be used to specify the machine type
685 number as it appears in the ARM machine registry
686 (see http://www.arm.linux.org.uk/developer/machines/).
687 Only boards that have multiple machine types supported
688 in a single configuration file and the machine type is
689 runtime discoverable, do not have to use this setting.
691 - vxWorks boot parameters:
693 bootvx constructs a valid bootline using the following
694 environments variables: bootfile, ipaddr, serverip, hostname.
695 It loads the vxWorks image pointed bootfile.
697 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
698 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
699 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
700 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
702 CONFIG_SYS_VXWORKS_ADD_PARAMS
704 Add it at the end of the bootline. E.g "u=username pw=secret"
706 Note: If a "bootargs" environment is defined, it will overwride
707 the defaults discussed just above.
709 - Cache Configuration:
710 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
711 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
712 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
714 - Cache Configuration for ARM:
715 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
717 CONFIG_SYS_PL310_BASE - Physical base address of PL310
718 controller register space
723 Define this if you want support for Amba PrimeCell PL010 UARTs.
727 Define this if you want support for Amba PrimeCell PL011 UARTs.
731 If you have Amba PrimeCell PL011 UARTs, set this variable to
732 the clock speed of the UARTs.
736 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
737 define this to a list of base addresses for each (supported)
738 port. See e.g. include/configs/versatile.h
740 CONFIG_PL011_SERIAL_RLCR
742 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
743 have separate receive and transmit line control registers. Set
744 this variable to initialize the extra register.
746 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
748 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
749 boot loader that has already initialized the UART. Define this
750 variable to flush the UART at init time.
752 CONFIG_SERIAL_HW_FLOW_CONTROL
754 Define this variable to enable hw flow control in serial driver.
755 Current user of this option is drivers/serial/nsl16550.c driver
758 Depending on board, define exactly one serial port
759 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
760 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
761 console by defining CONFIG_8xx_CONS_NONE
763 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
764 port routines must be defined elsewhere
765 (i.e. serial_init(), serial_getc(), ...)
768 Enables console device for a color framebuffer. Needs following
769 defines (cf. smiLynxEM, i8042)
770 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
772 VIDEO_HW_RECTFILL graphic chip supports
775 VIDEO_HW_BITBLT graphic chip supports
776 bit-blit (cf. smiLynxEM)
777 VIDEO_VISIBLE_COLS visible pixel columns
779 VIDEO_VISIBLE_ROWS visible pixel rows
780 VIDEO_PIXEL_SIZE bytes per pixel
781 VIDEO_DATA_FORMAT graphic data format
782 (0-5, cf. cfb_console.c)
783 VIDEO_FB_ADRS framebuffer address
784 VIDEO_KBD_INIT_FCT keyboard int fct
785 (i.e. i8042_kbd_init())
786 VIDEO_TSTC_FCT test char fct
788 VIDEO_GETC_FCT get char fct
790 CONFIG_CONSOLE_CURSOR cursor drawing on/off
791 (requires blink timer
793 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
794 CONFIG_CONSOLE_TIME display time/date info in
796 (requires CONFIG_CMD_DATE)
797 CONFIG_VIDEO_LOGO display Linux logo in
799 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
800 linux_logo.h for logo.
801 Requires CONFIG_VIDEO_LOGO
802 CONFIG_CONSOLE_EXTRA_INFO
803 additional board info beside
806 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
807 a limited number of ANSI escape sequences (cursor control,
808 erase functions and limited graphics rendition control).
810 When CONFIG_CFB_CONSOLE is defined, video console is
811 default i/o. Serial console can be forced with
812 environment 'console=serial'.
814 When CONFIG_SILENT_CONSOLE is defined, all console
815 messages (by U-Boot and Linux!) can be silenced with
816 the "silent" environment variable. See
817 doc/README.silent for more information.
819 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
821 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
825 CONFIG_BAUDRATE - in bps
826 Select one of the baudrates listed in
827 CONFIG_SYS_BAUDRATE_TABLE, see below.
828 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
830 - Console Rx buffer length
831 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
832 the maximum receive buffer length for the SMC.
833 This option is actual only for 82xx and 8xx possible.
834 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
835 must be defined, to setup the maximum idle timeout for
838 - Pre-Console Buffer:
839 Prior to the console being initialised (i.e. serial UART
840 initialised etc) all console output is silently discarded.
841 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
842 buffer any console messages prior to the console being
843 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
844 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
845 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
846 bytes are output before the console is initialised, the
847 earlier bytes are discarded.
849 'Sane' compilers will generate smaller code if
850 CONFIG_PRE_CON_BUF_SZ is a power of 2
852 - Safe printf() functions
853 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
854 the printf() functions. These are defined in
855 include/vsprintf.h and include snprintf(), vsnprintf() and
856 so on. Code size increase is approximately 300-500 bytes.
857 If this option is not given then these functions will
858 silently discard their buffer size argument - this means
859 you are not getting any overflow checking in this case.
861 - Boot Delay: CONFIG_BOOTDELAY - in seconds
862 Delay before automatically booting the default image;
863 set to -1 to disable autoboot.
864 set to -2 to autoboot with no delay and not check for abort
865 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
867 See doc/README.autoboot for these options that
868 work with CONFIG_BOOTDELAY. None are required.
869 CONFIG_BOOT_RETRY_TIME
870 CONFIG_BOOT_RETRY_MIN
871 CONFIG_AUTOBOOT_KEYED
872 CONFIG_AUTOBOOT_PROMPT
873 CONFIG_AUTOBOOT_DELAY_STR
874 CONFIG_AUTOBOOT_STOP_STR
875 CONFIG_AUTOBOOT_DELAY_STR2
876 CONFIG_AUTOBOOT_STOP_STR2
877 CONFIG_ZERO_BOOTDELAY_CHECK
878 CONFIG_RESET_TO_RETRY
882 Only needed when CONFIG_BOOTDELAY is enabled;
883 define a command string that is automatically executed
884 when no character is read on the console interface
885 within "Boot Delay" after reset.
888 This can be used to pass arguments to the bootm
889 command. The value of CONFIG_BOOTARGS goes into the
890 environment value "bootargs".
892 CONFIG_RAMBOOT and CONFIG_NFSBOOT
893 The value of these goes into the environment as
894 "ramboot" and "nfsboot" respectively, and can be used
895 as a convenience, when switching between booting from
899 CONFIG_BOOTCOUNT_LIMIT
900 Implements a mechanism for detecting a repeating reboot
902 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
905 If no softreset save registers are found on the hardware
906 "bootcount" is stored in the environment. To prevent a
907 saveenv on all reboots, the environment variable
908 "upgrade_available" is used. If "upgrade_available" is
909 0, "bootcount" is always 0, if "upgrade_available" is
910 1 "bootcount" is incremented in the environment.
911 So the Userspace Applikation must set the "upgrade_available"
912 and "bootcount" variable to 0, if a boot was successfully.
917 When this option is #defined, the existence of the
918 environment variable "preboot" will be checked
919 immediately before starting the CONFIG_BOOTDELAY
920 countdown and/or running the auto-boot command resp.
921 entering interactive mode.
923 This feature is especially useful when "preboot" is
924 automatically generated or modified. For an example
925 see the LWMON board specific code: here "preboot" is
926 modified when the user holds down a certain
927 combination of keys on the (special) keyboard when
930 - Serial Download Echo Mode:
932 If defined to 1, all characters received during a
933 serial download (using the "loads" command) are
934 echoed back. This might be needed by some terminal
935 emulations (like "cu"), but may as well just take
936 time on others. This setting #define's the initial
937 value of the "loads_echo" environment variable.
939 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
941 Select one of the baudrates listed in
942 CONFIG_SYS_BAUDRATE_TABLE, see below.
945 Monitor commands can be included or excluded
946 from the build by using the #include files
947 <config_cmd_all.h> and #undef'ing unwanted
948 commands, or using <config_cmd_default.h>
949 and augmenting with additional #define's
952 The default command configuration includes all commands
953 except those marked below with a "*".
955 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
956 CONFIG_CMD_ASKENV * ask for env variable
957 CONFIG_CMD_BDI bdinfo
958 CONFIG_CMD_BEDBUG * Include BedBug Debugger
959 CONFIG_CMD_BMP * BMP support
960 CONFIG_CMD_BSP * Board specific commands
961 CONFIG_CMD_BOOTD bootd
962 CONFIG_CMD_CACHE * icache, dcache
963 CONFIG_CMD_CLK * clock command support
964 CONFIG_CMD_CONSOLE coninfo
965 CONFIG_CMD_CRC32 * crc32
966 CONFIG_CMD_DATE * support for RTC, date/time...
967 CONFIG_CMD_DHCP * DHCP support
968 CONFIG_CMD_DIAG * Diagnostics
969 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
970 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
971 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
972 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
973 CONFIG_CMD_DTT * Digital Therm and Thermostat
974 CONFIG_CMD_ECHO echo arguments
975 CONFIG_CMD_EDITENV edit env variable
976 CONFIG_CMD_EEPROM * EEPROM read/write support
977 CONFIG_CMD_ELF * bootelf, bootvx
978 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
979 CONFIG_CMD_ENV_FLAGS * display details about env flags
980 CONFIG_CMD_ENV_EXISTS * check existence of env variable
981 CONFIG_CMD_EXPORTENV * export the environment
982 CONFIG_CMD_EXT2 * ext2 command support
983 CONFIG_CMD_EXT4 * ext4 command support
984 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
985 that work for multiple fs types
986 CONFIG_CMD_SAVEENV saveenv
987 CONFIG_CMD_FDC * Floppy Disk Support
988 CONFIG_CMD_FAT * FAT command support
989 CONFIG_CMD_FLASH flinfo, erase, protect
990 CONFIG_CMD_FPGA FPGA device initialization support
991 CONFIG_CMD_FUSE * Device fuse support
992 CONFIG_CMD_GETTIME * Get time since boot
993 CONFIG_CMD_GO * the 'go' command (exec code)
994 CONFIG_CMD_GREPENV * search environment
995 CONFIG_CMD_HASH * calculate hash / digest
996 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
997 CONFIG_CMD_I2C * I2C serial bus support
998 CONFIG_CMD_IDE * IDE harddisk support
999 CONFIG_CMD_IMI iminfo
1000 CONFIG_CMD_IMLS List all images found in NOR flash
1001 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
1002 CONFIG_CMD_IMMAP * IMMR dump support
1003 CONFIG_CMD_IOTRACE * I/O tracing for debugging
1004 CONFIG_CMD_IMPORTENV * import an environment
1005 CONFIG_CMD_INI * import data from an ini file into the env
1006 CONFIG_CMD_IRQ * irqinfo
1007 CONFIG_CMD_ITEST Integer/string test of 2 values
1008 CONFIG_CMD_JFFS2 * JFFS2 Support
1009 CONFIG_CMD_KGDB * kgdb
1010 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
1011 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
1013 CONFIG_CMD_LOADB loadb
1014 CONFIG_CMD_LOADS loads
1015 CONFIG_CMD_MD5SUM * print md5 message digest
1016 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
1017 CONFIG_CMD_MEMINFO * Display detailed memory information
1018 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1020 CONFIG_CMD_MEMTEST * mtest
1021 CONFIG_CMD_MISC Misc functions like sleep etc
1022 CONFIG_CMD_MMC * MMC memory mapped support
1023 CONFIG_CMD_MII * MII utility commands
1024 CONFIG_CMD_MTDPARTS * MTD partition support
1025 CONFIG_CMD_NAND * NAND support
1026 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1027 CONFIG_CMD_NFS NFS support
1028 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1029 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1030 CONFIG_CMD_PCI * pciinfo
1031 CONFIG_CMD_PCMCIA * PCMCIA support
1032 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1034 CONFIG_CMD_PORTIO * Port I/O
1035 CONFIG_CMD_READ * Read raw data from partition
1036 CONFIG_CMD_REGINFO * Register dump
1037 CONFIG_CMD_RUN run command in env variable
1038 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1039 CONFIG_CMD_SAVES * save S record dump
1040 CONFIG_CMD_SCSI * SCSI Support
1041 CONFIG_CMD_SDRAM * print SDRAM configuration information
1042 (requires CONFIG_CMD_I2C)
1043 CONFIG_CMD_SETGETDCR Support for DCR Register access
1045 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1046 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1047 (requires CONFIG_CMD_MEMORY)
1048 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1049 CONFIG_CMD_SOURCE "source" command Support
1050 CONFIG_CMD_SPI * SPI serial bus support
1051 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1052 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1053 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1054 CONFIG_CMD_TIMER * access to the system tick timer
1055 CONFIG_CMD_USB * USB support
1056 CONFIG_CMD_CDP * Cisco Discover Protocol support
1057 CONFIG_CMD_MFSL * Microblaze FSL support
1058 CONFIG_CMD_XIMG Load part of Multi Image
1059 CONFIG_CMD_UUID * Generate random UUID or GUID string
1061 EXAMPLE: If you want all functions except of network
1062 support you can write:
1064 #include "config_cmd_all.h"
1065 #undef CONFIG_CMD_NET
1068 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1070 Note: Don't enable the "icache" and "dcache" commands
1071 (configuration option CONFIG_CMD_CACHE) unless you know
1072 what you (and your U-Boot users) are doing. Data
1073 cache cannot be enabled on systems like the 8xx or
1074 8260 (where accesses to the IMMR region must be
1075 uncached), and it cannot be disabled on all other
1076 systems where we (mis-) use the data cache to hold an
1077 initial stack and some data.
1080 XXX - this list needs to get updated!
1082 - Regular expression support:
1084 If this variable is defined, U-Boot is linked against
1085 the SLRE (Super Light Regular Expression) library,
1086 which adds regex support to some commands, as for
1087 example "env grep" and "setexpr".
1091 If this variable is defined, U-Boot will use a device tree
1092 to configure its devices, instead of relying on statically
1093 compiled #defines in the board file. This option is
1094 experimental and only available on a few boards. The device
1095 tree is available in the global data as gd->fdt_blob.
1097 U-Boot needs to get its device tree from somewhere. This can
1098 be done using one of the two options below:
1101 If this variable is defined, U-Boot will embed a device tree
1102 binary in its image. This device tree file should be in the
1103 board directory and called <soc>-<board>.dts. The binary file
1104 is then picked up in board_init_f() and made available through
1105 the global data structure as gd->blob.
1108 If this variable is defined, U-Boot will build a device tree
1109 binary. It will be called u-boot.dtb. Architecture-specific
1110 code will locate it at run-time. Generally this works by:
1112 cat u-boot.bin u-boot.dtb >image.bin
1114 and in fact, U-Boot does this for you, creating a file called
1115 u-boot-dtb.bin which is useful in the common case. You can
1116 still use the individual files if you need something more
1121 If this variable is defined, it enables watchdog
1122 support for the SoC. There must be support in the SoC
1123 specific code for a watchdog. For the 8xx and 8260
1124 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1125 register. When supported for a specific SoC is
1126 available, then no further board specific code should
1127 be needed to use it.
1130 When using a watchdog circuitry external to the used
1131 SoC, then define this variable and provide board
1132 specific code for the "hw_watchdog_reset" function.
1135 CONFIG_VERSION_VARIABLE
1136 If this variable is defined, an environment variable
1137 named "ver" is created by U-Boot showing the U-Boot
1138 version as printed by the "version" command.
1139 Any change to this variable will be reverted at the
1144 When CONFIG_CMD_DATE is selected, the type of the RTC
1145 has to be selected, too. Define exactly one of the
1148 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1149 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1150 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1151 CONFIG_RTC_MC146818 - use MC146818 RTC
1152 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1153 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1154 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1155 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1156 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1157 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1158 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1159 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1162 Note that if the RTC uses I2C, then the I2C interface
1163 must also be configured. See I2C Support, below.
1166 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1168 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1169 chip-ngpio pairs that tell the PCA953X driver the number of
1170 pins supported by a particular chip.
1172 Note that if the GPIO device uses I2C, then the I2C interface
1173 must also be configured. See I2C Support, below.
1176 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
1177 accesses and can checksum them or write a list of them out
1178 to memory. See the 'iotrace' command for details. This is
1179 useful for testing device drivers since it can confirm that
1180 the driver behaves the same way before and after a code
1181 change. Currently this is supported on sandbox and arm. To
1182 add support for your architecture, add '#include <iotrace.h>'
1183 to the bottom of arch/<arch>/include/asm/io.h and test.
1185 Example output from the 'iotrace stats' command is below.
1186 Note that if the trace buffer is exhausted, the checksum will
1187 still continue to operate.
1190 Start: 10000000 (buffer start address)
1191 Size: 00010000 (buffer size)
1192 Offset: 00000120 (current buffer offset)
1193 Output: 10000120 (start + offset)
1194 Count: 00000018 (number of trace records)
1195 CRC32: 9526fb66 (CRC32 of all trace records)
1197 - Timestamp Support:
1199 When CONFIG_TIMESTAMP is selected, the timestamp
1200 (date and time) of an image is printed by image
1201 commands like bootm or iminfo. This option is
1202 automatically enabled when you select CONFIG_CMD_DATE .
1204 - Partition Labels (disklabels) Supported:
1205 Zero or more of the following:
1206 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1207 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1208 Intel architecture, USB sticks, etc.
1209 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1210 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1211 bootloader. Note 2TB partition limit; see
1213 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1215 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1216 CONFIG_CMD_SCSI) you must configure support for at
1217 least one non-MTD partition type as well.
1220 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1221 board configurations files but used nowhere!
1223 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1224 be performed by calling the function
1225 ide_set_reset(int reset)
1226 which has to be defined in a board specific file
1231 Set this to enable ATAPI support.
1236 Set this to enable support for disks larger than 137GB
1237 Also look at CONFIG_SYS_64BIT_LBA.
1238 Whithout these , LBA48 support uses 32bit variables and will 'only'
1239 support disks up to 2.1TB.
1241 CONFIG_SYS_64BIT_LBA:
1242 When enabled, makes the IDE subsystem use 64bit sector addresses.
1246 At the moment only there is only support for the
1247 SYM53C8XX SCSI controller; define
1248 CONFIG_SCSI_SYM53C8XX to enable it.
1250 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1251 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1252 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1253 maximum numbers of LUNs, SCSI ID's and target
1255 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1257 The environment variable 'scsidevs' is set to the number of
1258 SCSI devices found during the last scan.
1260 - NETWORK Support (PCI):
1262 Support for Intel 8254x/8257x gigabit chips.
1265 Utility code for direct access to the SPI bus on Intel 8257x.
1266 This does not do anything useful unless you set at least one
1267 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1269 CONFIG_E1000_SPI_GENERIC
1270 Allow generic access to the SPI bus on the Intel 8257x, for
1271 example with the "sspi" command.
1274 Management command for E1000 devices. When used on devices
1275 with SPI support you can reprogram the EEPROM from U-Boot.
1277 CONFIG_E1000_FALLBACK_MAC
1278 default MAC for empty EEPROM after production.
1281 Support for Intel 82557/82559/82559ER chips.
1282 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1283 write routine for first time initialisation.
1286 Support for Digital 2114x chips.
1287 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1288 modem chip initialisation (KS8761/QS6611).
1291 Support for National dp83815 chips.
1294 Support for National dp8382[01] gigabit chips.
1296 - NETWORK Support (other):
1298 CONFIG_DRIVER_AT91EMAC
1299 Support for AT91RM9200 EMAC.
1302 Define this to use reduced MII inteface
1304 CONFIG_DRIVER_AT91EMAC_QUIET
1305 If this defined, the driver is quiet.
1306 The driver doen't show link status messages.
1308 CONFIG_CALXEDA_XGMAC
1309 Support for the Calxeda XGMAC device
1312 Support for SMSC's LAN91C96 chips.
1314 CONFIG_LAN91C96_BASE
1315 Define this to hold the physical address
1316 of the LAN91C96's I/O space
1318 CONFIG_LAN91C96_USE_32_BIT
1319 Define this to enable 32 bit addressing
1322 Support for SMSC's LAN91C111 chip
1324 CONFIG_SMC91111_BASE
1325 Define this to hold the physical address
1326 of the device (I/O space)
1328 CONFIG_SMC_USE_32_BIT
1329 Define this if data bus is 32 bits
1331 CONFIG_SMC_USE_IOFUNCS
1332 Define this to use i/o functions instead of macros
1333 (some hardware wont work with macros)
1335 CONFIG_DRIVER_TI_EMAC
1336 Support for davinci emac
1338 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1339 Define this if you have more then 3 PHYs.
1342 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1344 CONFIG_FTGMAC100_EGIGA
1345 Define this to use GE link update with gigabit PHY.
1346 Define this if FTGMAC100 is connected to gigabit PHY.
1347 If your system has 10/100 PHY only, it might not occur
1348 wrong behavior. Because PHY usually return timeout or
1349 useless data when polling gigabit status and gigabit
1350 control registers. This behavior won't affect the
1351 correctnessof 10/100 link speed update.
1354 Support for SMSC's LAN911x and LAN921x chips
1357 Define this to hold the physical address
1358 of the device (I/O space)
1360 CONFIG_SMC911X_32_BIT
1361 Define this if data bus is 32 bits
1363 CONFIG_SMC911X_16_BIT
1364 Define this if data bus is 16 bits. If your processor
1365 automatically converts one 32 bit word to two 16 bit
1366 words you may also try CONFIG_SMC911X_32_BIT.
1369 Support for Renesas on-chip Ethernet controller
1371 CONFIG_SH_ETHER_USE_PORT
1372 Define the number of ports to be used
1374 CONFIG_SH_ETHER_PHY_ADDR
1375 Define the ETH PHY's address
1377 CONFIG_SH_ETHER_CACHE_WRITEBACK
1378 If this option is set, the driver enables cache flush.
1382 Support TPM devices.
1385 Support for i2c bus TPM devices. Only one device
1386 per system is supported at this time.
1388 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1389 Define the the i2c bus number for the TPM device
1391 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1392 Define the TPM's address on the i2c bus
1394 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1395 Define the burst count bytes upper limit
1397 CONFIG_TPM_ATMEL_TWI
1398 Support for Atmel TWI TPM device. Requires I2C support.
1401 Support for generic parallel port TPM devices. Only one device
1402 per system is supported at this time.
1404 CONFIG_TPM_TIS_BASE_ADDRESS
1405 Base address where the generic TPM device is mapped
1406 to. Contemporary x86 systems usually map it at
1410 Add tpm monitor functions.
1411 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1412 provides monitor access to authorized functions.
1415 Define this to enable the TPM support library which provides
1416 functional interfaces to some TPM commands.
1417 Requires support for a TPM device.
1419 CONFIG_TPM_AUTH_SESSIONS
1420 Define this to enable authorized functions in the TPM library.
1421 Requires CONFIG_TPM and CONFIG_SHA1.
1424 At the moment only the UHCI host controller is
1425 supported (PIP405, MIP405, MPC5200); define
1426 CONFIG_USB_UHCI to enable it.
1427 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1428 and define CONFIG_USB_STORAGE to enable the USB
1431 Supported are USB Keyboards and USB Floppy drives
1433 MPC5200 USB requires additional defines:
1435 for 528 MHz Clock: 0x0001bbbb
1439 for differential drivers: 0x00001000
1440 for single ended drivers: 0x00005000
1441 for differential drivers on PSC3: 0x00000100
1442 for single ended drivers on PSC3: 0x00004100
1443 CONFIG_SYS_USB_EVENT_POLL
1444 May be defined to allow interrupt polling
1445 instead of using asynchronous interrupts
1447 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1448 txfilltuning field in the EHCI controller on reset.
1451 Define the below if you wish to use the USB console.
1452 Once firmware is rebuilt from a serial console issue the
1453 command "setenv stdin usbtty; setenv stdout usbtty" and
1454 attach your USB cable. The Unix command "dmesg" should print
1455 it has found a new device. The environment variable usbtty
1456 can be set to gserial or cdc_acm to enable your device to
1457 appear to a USB host as a Linux gserial device or a
1458 Common Device Class Abstract Control Model serial device.
1459 If you select usbtty = gserial you should be able to enumerate
1461 # modprobe usbserial vendor=0xVendorID product=0xProductID
1462 else if using cdc_acm, simply setting the environment
1463 variable usbtty to be cdc_acm should suffice. The following
1464 might be defined in YourBoardName.h
1467 Define this to build a UDC device
1470 Define this to have a tty type of device available to
1471 talk to the UDC device
1474 Define this to enable the high speed support for usb
1475 device and usbtty. If this feature is enabled, a routine
1476 int is_usbd_high_speed(void)
1477 also needs to be defined by the driver to dynamically poll
1478 whether the enumeration has succeded at high speed or full
1481 CONFIG_SYS_CONSOLE_IS_IN_ENV
1482 Define this if you want stdin, stdout &/or stderr to
1486 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1487 Derive USB clock from external clock "blah"
1488 - CONFIG_SYS_USB_EXTC_CLK 0x02
1490 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1491 Derive USB clock from brgclk
1492 - CONFIG_SYS_USB_BRG_CLK 0x04
1494 If you have a USB-IF assigned VendorID then you may wish to
1495 define your own vendor specific values either in BoardName.h
1496 or directly in usbd_vendor_info.h. If you don't define
1497 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1498 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1499 should pretend to be a Linux device to it's target host.
1501 CONFIG_USBD_MANUFACTURER
1502 Define this string as the name of your company for
1503 - CONFIG_USBD_MANUFACTURER "my company"
1505 CONFIG_USBD_PRODUCT_NAME
1506 Define this string as the name of your product
1507 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1509 CONFIG_USBD_VENDORID
1510 Define this as your assigned Vendor ID from the USB
1511 Implementors Forum. This *must* be a genuine Vendor ID
1512 to avoid polluting the USB namespace.
1513 - CONFIG_USBD_VENDORID 0xFFFF
1515 CONFIG_USBD_PRODUCTID
1516 Define this as the unique Product ID
1518 - CONFIG_USBD_PRODUCTID 0xFFFF
1520 - ULPI Layer Support:
1521 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1522 the generic ULPI layer. The generic layer accesses the ULPI PHY
1523 via the platform viewport, so you need both the genric layer and
1524 the viewport enabled. Currently only Chipidea/ARC based
1525 viewport is supported.
1526 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1527 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1528 If your ULPI phy needs a different reference clock than the
1529 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1530 the appropriate value in Hz.
1533 The MMC controller on the Intel PXA is supported. To
1534 enable this define CONFIG_MMC. The MMC can be
1535 accessed from the boot prompt by mapping the device
1536 to physical memory similar to flash. Command line is
1537 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1538 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1541 Support for Renesas on-chip MMCIF controller
1543 CONFIG_SH_MMCIF_ADDR
1544 Define the base address of MMCIF registers
1547 Define the clock frequency for MMCIF
1550 Enable the generic MMC driver
1552 CONFIG_SUPPORT_EMMC_BOOT
1553 Enable some additional features of the eMMC boot partitions.
1555 CONFIG_SUPPORT_EMMC_RPMB
1556 Enable the commands for reading, writing and programming the
1557 key for the Replay Protection Memory Block partition in eMMC.
1559 - USB Device Firmware Update (DFU) class support:
1561 This enables the USB portion of the DFU USB class
1564 This enables the command "dfu" which is used to have
1565 U-Boot create a DFU class device via USB. This command
1566 requires that the "dfu_alt_info" environment variable be
1567 set and define the alt settings to expose to the host.
1570 This enables support for exposing (e)MMC devices via DFU.
1573 This enables support for exposing NAND devices via DFU.
1576 This enables support for exposing RAM via DFU.
1577 Note: DFU spec refer to non-volatile memory usage, but
1578 allow usages beyond the scope of spec - here RAM usage,
1579 one that would help mostly the developer.
1581 CONFIG_SYS_DFU_DATA_BUF_SIZE
1582 Dfu transfer uses a buffer before writing data to the
1583 raw storage device. Make the size (in bytes) of this buffer
1584 configurable. The size of this buffer is also configurable
1585 through the "dfu_bufsiz" environment variable.
1587 CONFIG_SYS_DFU_MAX_FILE_SIZE
1588 When updating files rather than the raw storage device,
1589 we use a static buffer to copy the file into and then write
1590 the buffer once we've been given the whole file. Define
1591 this to the maximum filesize (in bytes) for the buffer.
1592 Default is 4 MiB if undefined.
1594 DFU_DEFAULT_POLL_TIMEOUT
1595 Poll timeout [ms], is the timeout a device can send to the
1596 host. The host must wait for this timeout before sending
1597 a subsequent DFU_GET_STATUS request to the device.
1599 DFU_MANIFEST_POLL_TIMEOUT
1600 Poll timeout [ms], which the device sends to the host when
1601 entering dfuMANIFEST state. Host waits this timeout, before
1602 sending again an USB request to the device.
1604 - USB Device Android Fastboot support:
1606 This enables the command "fastboot" which enables the Android
1607 fastboot mode for the platform's USB device. Fastboot is a USB
1608 protocol for downloading images, flashing and device control
1609 used on Android devices.
1610 See doc/README.android-fastboot for more information.
1612 CONFIG_ANDROID_BOOT_IMAGE
1613 This enables support for booting images which use the Android
1614 image format header.
1616 CONFIG_USB_FASTBOOT_BUF_ADDR
1617 The fastboot protocol requires a large memory buffer for
1618 downloads. Define this to the starting RAM address to use for
1621 CONFIG_USB_FASTBOOT_BUF_SIZE
1622 The fastboot protocol requires a large memory buffer for
1623 downloads. This buffer should be as large as possible for a
1624 platform. Define this to the size available RAM for fastboot.
1626 - Journaling Flash filesystem support:
1627 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1628 CONFIG_JFFS2_NAND_DEV
1629 Define these for a default partition on a NAND device
1631 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1632 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1633 Define these for a default partition on a NOR device
1635 CONFIG_SYS_JFFS_CUSTOM_PART
1636 Define this to create an own partition. You have to provide a
1637 function struct part_info* jffs2_part_info(int part_num)
1639 If you define only one JFFS2 partition you may also want to
1640 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1641 to disable the command chpart. This is the default when you
1642 have not defined a custom partition
1644 - FAT(File Allocation Table) filesystem write function support:
1647 Define this to enable support for saving memory data as a
1648 file in FAT formatted partition.
1650 This will also enable the command "fatwrite" enabling the
1651 user to write files to FAT.
1653 CBFS (Coreboot Filesystem) support
1656 Define this to enable support for reading from a Coreboot
1657 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1660 - FAT(File Allocation Table) filesystem cluster size:
1661 CONFIG_FS_FAT_MAX_CLUSTSIZE
1663 Define the max cluster size for fat operations else
1664 a default value of 65536 will be defined.
1669 Define this to enable standard (PC-Style) keyboard
1673 Standard PC keyboard driver with US (is default) and
1674 GERMAN key layout (switch via environment 'keymap=de') support.
1675 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1676 for cfb_console. Supports cursor blinking.
1679 Enables a Chrome OS keyboard using the CROS_EC interface.
1680 This uses CROS_EC to communicate with a second microcontroller
1681 which provides key scans on request.
1686 Define this to enable video support (for output to
1689 CONFIG_VIDEO_CT69000
1691 Enable Chips & Technologies 69000 Video chip
1693 CONFIG_VIDEO_SMI_LYNXEM
1694 Enable Silicon Motion SMI 712/710/810 Video chip. The
1695 video output is selected via environment 'videoout'
1696 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1699 For the CT69000 and SMI_LYNXEM drivers, videomode is
1700 selected via environment 'videomode'. Two different ways
1702 - "videomode=num" 'num' is a standard LiLo mode numbers.
1703 Following standard modes are supported (* is default):
1705 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1706 -------------+---------------------------------------------
1707 8 bits | 0x301* 0x303 0x305 0x161 0x307
1708 15 bits | 0x310 0x313 0x316 0x162 0x319
1709 16 bits | 0x311 0x314 0x317 0x163 0x31A
1710 24 bits | 0x312 0x315 0x318 ? 0x31B
1711 -------------+---------------------------------------------
1712 (i.e. setenv videomode 317; saveenv; reset;)
1714 - "videomode=bootargs" all the video parameters are parsed
1715 from the bootargs. (See drivers/video/videomodes.c)
1718 CONFIG_VIDEO_SED13806
1719 Enable Epson SED13806 driver. This driver supports 8bpp
1720 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1721 or CONFIG_VIDEO_SED13806_16BPP
1724 Enable the Freescale DIU video driver. Reference boards for
1725 SOCs that have a DIU should define this macro to enable DIU
1726 support, and should also define these other macros:
1732 CONFIG_VIDEO_SW_CURSOR
1733 CONFIG_VGA_AS_SINGLE_DEVICE
1735 CONFIG_VIDEO_BMP_LOGO
1737 The DIU driver will look for the 'video-mode' environment
1738 variable, and if defined, enable the DIU as a console during
1739 boot. See the documentation file README.video for a
1740 description of this variable.
1744 Enable the VGA video / BIOS for x86. The alternative if you
1745 are using coreboot is to use the coreboot frame buffer
1752 Define this to enable a custom keyboard support.
1753 This simply calls drv_keyboard_init() which must be
1754 defined in your board-specific files.
1755 The only board using this so far is RBC823.
1757 - LCD Support: CONFIG_LCD
1759 Define this to enable LCD support (for output to LCD
1760 display); also select one of the supported displays
1761 by defining one of these:
1765 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1767 CONFIG_NEC_NL6448AC33:
1769 NEC NL6448AC33-18. Active, color, single scan.
1771 CONFIG_NEC_NL6448BC20
1773 NEC NL6448BC20-08. 6.5", 640x480.
1774 Active, color, single scan.
1776 CONFIG_NEC_NL6448BC33_54
1778 NEC NL6448BC33-54. 10.4", 640x480.
1779 Active, color, single scan.
1783 Sharp 320x240. Active, color, single scan.
1784 It isn't 16x9, and I am not sure what it is.
1786 CONFIG_SHARP_LQ64D341
1788 Sharp LQ64D341 display, 640x480.
1789 Active, color, single scan.
1793 HLD1045 display, 640x480.
1794 Active, color, single scan.
1798 Optrex CBL50840-2 NF-FW 99 22 M5
1800 Hitachi LMG6912RPFC-00T
1804 320x240. Black & white.
1806 Normally display is black on white background; define
1807 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1809 CONFIG_LCD_ALIGNMENT
1811 Normally the LCD is page-aligned (tyically 4KB). If this is
1812 defined then the LCD will be aligned to this value instead.
1813 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1814 here, since it is cheaper to change data cache settings on
1815 a per-section basis.
1817 CONFIG_CONSOLE_SCROLL_LINES
1819 When the console need to be scrolled, this is the number of
1820 lines to scroll by. It defaults to 1. Increasing this makes
1821 the console jump but can help speed up operation when scrolling
1826 Support drawing of RLE8-compressed bitmaps on the LCD.
1830 Enables an 'i2c edid' command which can read EDID
1831 information over I2C from an attached LCD display.
1833 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1835 If this option is set, the environment is checked for
1836 a variable "splashimage". If found, the usual display
1837 of logo, copyright and system information on the LCD
1838 is suppressed and the BMP image at the address
1839 specified in "splashimage" is loaded instead. The
1840 console is redirected to the "nulldev", too. This
1841 allows for a "silent" boot where a splash screen is
1842 loaded very quickly after power-on.
1844 CONFIG_SPLASHIMAGE_GUARD
1846 If this option is set, then U-Boot will prevent the environment
1847 variable "splashimage" from being set to a problematic address
1848 (see README.displaying-bmps).
1849 This option is useful for targets where, due to alignment
1850 restrictions, an improperly aligned BMP image will cause a data
1851 abort. If you think you will not have problems with unaligned
1852 accesses (for example because your toolchain prevents them)
1853 there is no need to set this option.
1855 CONFIG_SPLASH_SCREEN_ALIGN
1857 If this option is set the splash image can be freely positioned
1858 on the screen. Environment variable "splashpos" specifies the
1859 position as "x,y". If a positive number is given it is used as
1860 number of pixel from left/top. If a negative number is given it
1861 is used as number of pixel from right/bottom. You can also
1862 specify 'm' for centering the image.
1865 setenv splashpos m,m
1866 => image at center of screen
1868 setenv splashpos 30,20
1869 => image at x = 30 and y = 20
1871 setenv splashpos -10,m
1872 => vertically centered image
1873 at x = dspWidth - bmpWidth - 9
1875 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1877 If this option is set, additionally to standard BMP
1878 images, gzipped BMP images can be displayed via the
1879 splashscreen support or the bmp command.
1881 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1883 If this option is set, 8-bit RLE compressed BMP images
1884 can be displayed via the splashscreen support or the
1887 - Do compresssing for memory range:
1890 If this option is set, it would use zlib deflate method
1891 to compress the specified memory at its best effort.
1893 - Compression support:
1896 Enabled by default to support gzip compressed images.
1900 If this option is set, support for bzip2 compressed
1901 images is included. If not, only uncompressed and gzip
1902 compressed images are supported.
1904 NOTE: the bzip2 algorithm requires a lot of RAM, so
1905 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1910 If this option is set, support for lzma compressed
1913 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1914 requires an amount of dynamic memory that is given by the
1917 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1919 Where lc and lp stand for, respectively, Literal context bits
1920 and Literal pos bits.
1922 This value is upper-bounded by 14MB in the worst case. Anyway,
1923 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1924 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1925 a very small buffer.
1927 Use the lzmainfo tool to determinate the lc and lp values and
1928 then calculate the amount of needed dynamic memory (ensuring
1929 the appropriate CONFIG_SYS_MALLOC_LEN value).
1933 If this option is set, support for LZO compressed images
1939 The address of PHY on MII bus.
1941 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1943 The clock frequency of the MII bus
1947 If this option is set, support for speed/duplex
1948 detection of gigabit PHY is included.
1950 CONFIG_PHY_RESET_DELAY
1952 Some PHY like Intel LXT971A need extra delay after
1953 reset before any MII register access is possible.
1954 For such PHY, set this option to the usec delay
1955 required. (minimum 300usec for LXT971A)
1957 CONFIG_PHY_CMD_DELAY (ppc4xx)
1959 Some PHY like Intel LXT971A need extra delay after
1960 command issued before MII status register can be read
1970 Define a default value for Ethernet address to use
1971 for the respective Ethernet interface, in case this
1972 is not determined automatically.
1977 Define a default value for the IP address to use for
1978 the default Ethernet interface, in case this is not
1979 determined through e.g. bootp.
1980 (Environment variable "ipaddr")
1982 - Server IP address:
1985 Defines a default value for the IP address of a TFTP
1986 server to contact when using the "tftboot" command.
1987 (Environment variable "serverip")
1989 CONFIG_KEEP_SERVERADDR
1991 Keeps the server's MAC address, in the env 'serveraddr'
1992 for passing to bootargs (like Linux's netconsole option)
1994 - Gateway IP address:
1997 Defines a default value for the IP address of the
1998 default router where packets to other networks are
2000 (Environment variable "gatewayip")
2005 Defines a default value for the subnet mask (or
2006 routing prefix) which is used to determine if an IP
2007 address belongs to the local subnet or needs to be
2008 forwarded through a router.
2009 (Environment variable "netmask")
2011 - Multicast TFTP Mode:
2014 Defines whether you want to support multicast TFTP as per
2015 rfc-2090; for example to work with atftp. Lets lots of targets
2016 tftp down the same boot image concurrently. Note: the Ethernet
2017 driver in use must provide a function: mcast() to join/leave a
2020 - BOOTP Recovery Mode:
2021 CONFIG_BOOTP_RANDOM_DELAY
2023 If you have many targets in a network that try to
2024 boot using BOOTP, you may want to avoid that all
2025 systems send out BOOTP requests at precisely the same
2026 moment (which would happen for instance at recovery
2027 from a power failure, when all systems will try to
2028 boot, thus flooding the BOOTP server. Defining
2029 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2030 inserted before sending out BOOTP requests. The
2031 following delays are inserted then:
2033 1st BOOTP request: delay 0 ... 1 sec
2034 2nd BOOTP request: delay 0 ... 2 sec
2035 3rd BOOTP request: delay 0 ... 4 sec
2037 BOOTP requests: delay 0 ... 8 sec
2039 CONFIG_BOOTP_ID_CACHE_SIZE
2041 BOOTP packets are uniquely identified using a 32-bit ID. The
2042 server will copy the ID from client requests to responses and
2043 U-Boot will use this to determine if it is the destination of
2044 an incoming response. Some servers will check that addresses
2045 aren't in use before handing them out (usually using an ARP
2046 ping) and therefore take up to a few hundred milliseconds to
2047 respond. Network congestion may also influence the time it
2048 takes for a response to make it back to the client. If that
2049 time is too long, U-Boot will retransmit requests. In order
2050 to allow earlier responses to still be accepted after these
2051 retransmissions, U-Boot's BOOTP client keeps a small cache of
2052 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
2053 cache. The default is to keep IDs for up to four outstanding
2054 requests. Increasing this will allow U-Boot to accept offers
2055 from a BOOTP client in networks with unusually high latency.
2057 - DHCP Advanced Options:
2058 You can fine tune the DHCP functionality by defining
2059 CONFIG_BOOTP_* symbols:
2061 CONFIG_BOOTP_SUBNETMASK
2062 CONFIG_BOOTP_GATEWAY
2063 CONFIG_BOOTP_HOSTNAME
2064 CONFIG_BOOTP_NISDOMAIN
2065 CONFIG_BOOTP_BOOTPATH
2066 CONFIG_BOOTP_BOOTFILESIZE
2069 CONFIG_BOOTP_SEND_HOSTNAME
2070 CONFIG_BOOTP_NTPSERVER
2071 CONFIG_BOOTP_TIMEOFFSET
2072 CONFIG_BOOTP_VENDOREX
2073 CONFIG_BOOTP_MAY_FAIL
2075 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2076 environment variable, not the BOOTP server.
2078 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2079 after the configured retry count, the call will fail
2080 instead of starting over. This can be used to fail over
2081 to Link-local IP address configuration if the DHCP server
2084 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2085 serverip from a DHCP server, it is possible that more
2086 than one DNS serverip is offered to the client.
2087 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2088 serverip will be stored in the additional environment
2089 variable "dnsip2". The first DNS serverip is always
2090 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2093 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2094 to do a dynamic update of a DNS server. To do this, they
2095 need the hostname of the DHCP requester.
2096 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2097 of the "hostname" environment variable is passed as
2098 option 12 to the DHCP server.
2100 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2102 A 32bit value in microseconds for a delay between
2103 receiving a "DHCP Offer" and sending the "DHCP Request".
2104 This fixes a problem with certain DHCP servers that don't
2105 respond 100% of the time to a "DHCP request". E.g. On an
2106 AT91RM9200 processor running at 180MHz, this delay needed
2107 to be *at least* 15,000 usec before a Windows Server 2003
2108 DHCP server would reply 100% of the time. I recommend at
2109 least 50,000 usec to be safe. The alternative is to hope
2110 that one of the retries will be successful but note that
2111 the DHCP timeout and retry process takes a longer than
2114 - Link-local IP address negotiation:
2115 Negotiate with other link-local clients on the local network
2116 for an address that doesn't require explicit configuration.
2117 This is especially useful if a DHCP server cannot be guaranteed
2118 to exist in all environments that the device must operate.
2120 See doc/README.link-local for more information.
2123 CONFIG_CDP_DEVICE_ID
2125 The device id used in CDP trigger frames.
2127 CONFIG_CDP_DEVICE_ID_PREFIX
2129 A two character string which is prefixed to the MAC address
2134 A printf format string which contains the ascii name of
2135 the port. Normally is set to "eth%d" which sets
2136 eth0 for the first Ethernet, eth1 for the second etc.
2138 CONFIG_CDP_CAPABILITIES
2140 A 32bit integer which indicates the device capabilities;
2141 0x00000010 for a normal host which does not forwards.
2145 An ascii string containing the version of the software.
2149 An ascii string containing the name of the platform.
2153 A 32bit integer sent on the trigger.
2155 CONFIG_CDP_POWER_CONSUMPTION
2157 A 16bit integer containing the power consumption of the
2158 device in .1 of milliwatts.
2160 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2162 A byte containing the id of the VLAN.
2164 - Status LED: CONFIG_STATUS_LED
2166 Several configurations allow to display the current
2167 status using a LED. For instance, the LED will blink
2168 fast while running U-Boot code, stop blinking as
2169 soon as a reply to a BOOTP request was received, and
2170 start blinking slow once the Linux kernel is running
2171 (supported by a status LED driver in the Linux
2172 kernel). Defining CONFIG_STATUS_LED enables this
2178 The status LED can be connected to a GPIO pin.
2179 In such cases, the gpio_led driver can be used as a
2180 status LED backend implementation. Define CONFIG_GPIO_LED
2181 to include the gpio_led driver in the U-Boot binary.
2183 CONFIG_GPIO_LED_INVERTED_TABLE
2184 Some GPIO connected LEDs may have inverted polarity in which
2185 case the GPIO high value corresponds to LED off state and
2186 GPIO low value corresponds to LED on state.
2187 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2188 with a list of GPIO LEDs that have inverted polarity.
2190 - CAN Support: CONFIG_CAN_DRIVER
2192 Defining CONFIG_CAN_DRIVER enables CAN driver support
2193 on those systems that support this (optional)
2194 feature, like the TQM8xxL modules.
2196 - I2C Support: CONFIG_SYS_I2C
2198 This enable the NEW i2c subsystem, and will allow you to use
2199 i2c commands at the u-boot command line (as long as you set
2200 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2201 based realtime clock chips or other i2c devices. See
2202 common/cmd_i2c.c for a description of the command line
2205 ported i2c driver to the new framework:
2206 - drivers/i2c/soft_i2c.c:
2207 - activate first bus with CONFIG_SYS_I2C_SOFT define
2208 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2209 for defining speed and slave address
2210 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2211 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2212 for defining speed and slave address
2213 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2214 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2215 for defining speed and slave address
2216 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2217 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2218 for defining speed and slave address
2220 - drivers/i2c/fsl_i2c.c:
2221 - activate i2c driver with CONFIG_SYS_I2C_FSL
2222 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2223 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2224 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2226 - If your board supports a second fsl i2c bus, define
2227 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2228 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2229 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2232 - drivers/i2c/tegra_i2c.c:
2233 - activate this driver with CONFIG_SYS_I2C_TEGRA
2234 - This driver adds 4 i2c buses with a fix speed from
2235 100000 and the slave addr 0!
2237 - drivers/i2c/ppc4xx_i2c.c
2238 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2239 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2240 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2242 - drivers/i2c/i2c_mxc.c
2243 - activate this driver with CONFIG_SYS_I2C_MXC
2244 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2245 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2246 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2247 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2248 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2249 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2250 If thoses defines are not set, default value is 100000
2251 for speed, and 0 for slave.
2253 - drivers/i2c/rcar_i2c.c:
2254 - activate this driver with CONFIG_SYS_I2C_RCAR
2255 - This driver adds 4 i2c buses
2257 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2258 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2259 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2260 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2261 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2262 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2263 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2264 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2265 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2267 - drivers/i2c/sh_i2c.c:
2268 - activate this driver with CONFIG_SYS_I2C_SH
2269 - This driver adds from 2 to 5 i2c buses
2271 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2272 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2273 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2274 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2275 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2276 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2277 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2278 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2279 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2280 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2281 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2282 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2283 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2285 - drivers/i2c/omap24xx_i2c.c
2286 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2287 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2288 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2289 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2290 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2291 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2292 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2293 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2294 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2295 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2296 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2298 - drivers/i2c/zynq_i2c.c
2299 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2300 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2301 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2303 - drivers/i2c/s3c24x0_i2c.c:
2304 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2305 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2306 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2307 with a fix speed from 100000 and the slave addr 0!
2309 - drivers/i2c/ihs_i2c.c
2310 - activate this driver with CONFIG_SYS_I2C_IHS
2311 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2312 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2313 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2314 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2315 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2316 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2317 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2318 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2319 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2320 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2321 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2322 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2326 CONFIG_SYS_NUM_I2C_BUSES
2327 Hold the number of i2c busses you want to use. If you
2328 don't use/have i2c muxes on your i2c bus, this
2329 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2332 CONFIG_SYS_I2C_DIRECT_BUS
2333 define this, if you don't use i2c muxes on your hardware.
2334 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2337 CONFIG_SYS_I2C_MAX_HOPS
2338 define how many muxes are maximal consecutively connected
2339 on one i2c bus. If you not use i2c muxes, omit this
2342 CONFIG_SYS_I2C_BUSES
2343 hold a list of busses you want to use, only used if
2344 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2345 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2346 CONFIG_SYS_NUM_I2C_BUSES = 9:
2348 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2349 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2350 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2351 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2352 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2353 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2354 {1, {I2C_NULL_HOP}}, \
2355 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2356 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2360 bus 0 on adapter 0 without a mux
2361 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2362 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2363 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2364 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2365 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2366 bus 6 on adapter 1 without a mux
2367 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2368 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2370 If you do not have i2c muxes on your board, omit this define.
2372 - Legacy I2C Support: CONFIG_HARD_I2C
2374 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2375 provides the following compelling advantages:
2377 - more than one i2c adapter is usable
2378 - approved multibus support
2379 - better i2c mux support
2381 ** Please consider updating your I2C driver now. **
2383 These enable legacy I2C serial bus commands. Defining
2384 CONFIG_HARD_I2C will include the appropriate I2C driver
2385 for the selected CPU.
2387 This will allow you to use i2c commands at the u-boot
2388 command line (as long as you set CONFIG_CMD_I2C in
2389 CONFIG_COMMANDS) and communicate with i2c based realtime
2390 clock chips. See common/cmd_i2c.c for a description of the
2391 command line interface.
2393 CONFIG_HARD_I2C selects a hardware I2C controller.
2395 There are several other quantities that must also be
2396 defined when you define CONFIG_HARD_I2C.
2398 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2399 to be the frequency (in Hz) at which you wish your i2c bus
2400 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2401 the CPU's i2c node address).
2403 Now, the u-boot i2c code for the mpc8xx
2404 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2405 and so its address should therefore be cleared to 0 (See,
2406 eg, MPC823e User's Manual p.16-473). So, set
2407 CONFIG_SYS_I2C_SLAVE to 0.
2409 CONFIG_SYS_I2C_INIT_MPC5XXX
2411 When a board is reset during an i2c bus transfer
2412 chips might think that the current transfer is still
2413 in progress. Reset the slave devices by sending start
2414 commands until the slave device responds.
2416 That's all that's required for CONFIG_HARD_I2C.
2418 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2419 then the following macros need to be defined (examples are
2420 from include/configs/lwmon.h):
2424 (Optional). Any commands necessary to enable the I2C
2425 controller or configure ports.
2427 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2431 (Only for MPC8260 CPU). The I/O port to use (the code
2432 assumes both bits are on the same port). Valid values
2433 are 0..3 for ports A..D.
2437 The code necessary to make the I2C data line active
2438 (driven). If the data line is open collector, this
2441 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2445 The code necessary to make the I2C data line tri-stated
2446 (inactive). If the data line is open collector, this
2449 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2453 Code that returns true if the I2C data line is high,
2456 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2460 If <bit> is true, sets the I2C data line high. If it
2461 is false, it clears it (low).
2463 eg: #define I2C_SDA(bit) \
2464 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2465 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2469 If <bit> is true, sets the I2C clock line high. If it
2470 is false, it clears it (low).
2472 eg: #define I2C_SCL(bit) \
2473 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2474 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2478 This delay is invoked four times per clock cycle so this
2479 controls the rate of data transfer. The data rate thus
2480 is 1 / (I2C_DELAY * 4). Often defined to be something
2483 #define I2C_DELAY udelay(2)
2485 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2487 If your arch supports the generic GPIO framework (asm/gpio.h),
2488 then you may alternatively define the two GPIOs that are to be
2489 used as SCL / SDA. Any of the previous I2C_xxx macros will
2490 have GPIO-based defaults assigned to them as appropriate.
2492 You should define these to the GPIO value as given directly to
2493 the generic GPIO functions.
2495 CONFIG_SYS_I2C_INIT_BOARD
2497 When a board is reset during an i2c bus transfer
2498 chips might think that the current transfer is still
2499 in progress. On some boards it is possible to access
2500 the i2c SCLK line directly, either by using the
2501 processor pin as a GPIO or by having a second pin
2502 connected to the bus. If this option is defined a
2503 custom i2c_init_board() routine in boards/xxx/board.c
2504 is run early in the boot sequence.
2506 CONFIG_SYS_I2C_BOARD_LATE_INIT
2508 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2509 defined a custom i2c_board_late_init() routine in
2510 boards/xxx/board.c is run AFTER the operations in i2c_init()
2511 is completed. This callpoint can be used to unreset i2c bus
2512 using CPU i2c controller register accesses for CPUs whose i2c
2513 controller provide such a method. It is called at the end of
2514 i2c_init() to allow i2c_init operations to setup the i2c bus
2515 controller on the CPU (e.g. setting bus speed & slave address).
2517 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2519 This option enables configuration of bi_iic_fast[] flags
2520 in u-boot bd_info structure based on u-boot environment
2521 variable "i2cfast". (see also i2cfast)
2523 CONFIG_I2C_MULTI_BUS
2525 This option allows the use of multiple I2C buses, each of which
2526 must have a controller. At any point in time, only one bus is
2527 active. To switch to a different bus, use the 'i2c dev' command.
2528 Note that bus numbering is zero-based.
2530 CONFIG_SYS_I2C_NOPROBES
2532 This option specifies a list of I2C devices that will be skipped
2533 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2534 is set, specify a list of bus-device pairs. Otherwise, specify
2535 a 1D array of device addresses
2538 #undef CONFIG_I2C_MULTI_BUS
2539 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2541 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2543 #define CONFIG_I2C_MULTI_BUS
2544 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2546 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2548 CONFIG_SYS_SPD_BUS_NUM
2550 If defined, then this indicates the I2C bus number for DDR SPD.
2551 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2553 CONFIG_SYS_RTC_BUS_NUM
2555 If defined, then this indicates the I2C bus number for the RTC.
2556 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2558 CONFIG_SYS_DTT_BUS_NUM
2560 If defined, then this indicates the I2C bus number for the DTT.
2561 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2563 CONFIG_SYS_I2C_DTT_ADDR:
2565 If defined, specifies the I2C address of the DTT device.
2566 If not defined, then U-Boot uses predefined value for
2567 specified DTT device.
2569 CONFIG_SOFT_I2C_READ_REPEATED_START
2571 defining this will force the i2c_read() function in
2572 the soft_i2c driver to perform an I2C repeated start
2573 between writing the address pointer and reading the
2574 data. If this define is omitted the default behaviour
2575 of doing a stop-start sequence will be used. Most I2C
2576 devices can use either method, but some require one or
2579 - SPI Support: CONFIG_SPI
2581 Enables SPI driver (so far only tested with
2582 SPI EEPROM, also an instance works with Crystal A/D and
2583 D/As on the SACSng board)
2587 Enables the driver for SPI controller on SuperH. Currently
2588 only SH7757 is supported.
2592 Enables extended (16-bit) SPI EEPROM addressing.
2593 (symmetrical to CONFIG_I2C_X)
2597 Enables a software (bit-bang) SPI driver rather than
2598 using hardware support. This is a general purpose
2599 driver that only requires three general I/O port pins
2600 (two outputs, one input) to function. If this is
2601 defined, the board configuration must define several
2602 SPI configuration items (port pins to use, etc). For
2603 an example, see include/configs/sacsng.h.
2607 Enables a hardware SPI driver for general-purpose reads
2608 and writes. As with CONFIG_SOFT_SPI, the board configuration
2609 must define a list of chip-select function pointers.
2610 Currently supported on some MPC8xxx processors. For an
2611 example, see include/configs/mpc8349emds.h.
2615 Enables the driver for the SPI controllers on i.MX and MXC
2616 SoCs. Currently i.MX31/35/51 are supported.
2618 CONFIG_SYS_SPI_MXC_WAIT
2619 Timeout for waiting until spi transfer completed.
2620 default: (CONFIG_SYS_HZ/100) /* 10 ms */
2622 - FPGA Support: CONFIG_FPGA
2624 Enables FPGA subsystem.
2626 CONFIG_FPGA_<vendor>
2628 Enables support for specific chip vendors.
2631 CONFIG_FPGA_<family>
2633 Enables support for FPGA family.
2634 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2638 Specify the number of FPGA devices to support.
2640 CONFIG_CMD_FPGA_LOADMK
2642 Enable support for fpga loadmk command
2644 CONFIG_CMD_FPGA_LOADP
2646 Enable support for fpga loadp command - load partial bitstream
2648 CONFIG_CMD_FPGA_LOADBP
2650 Enable support for fpga loadbp command - load partial bitstream
2653 CONFIG_SYS_FPGA_PROG_FEEDBACK
2655 Enable printing of hash marks during FPGA configuration.
2657 CONFIG_SYS_FPGA_CHECK_BUSY
2659 Enable checks on FPGA configuration interface busy
2660 status by the configuration function. This option
2661 will require a board or device specific function to
2666 If defined, a function that provides delays in the FPGA
2667 configuration driver.
2669 CONFIG_SYS_FPGA_CHECK_CTRLC
2670 Allow Control-C to interrupt FPGA configuration
2672 CONFIG_SYS_FPGA_CHECK_ERROR
2674 Check for configuration errors during FPGA bitfile
2675 loading. For example, abort during Virtex II
2676 configuration if the INIT_B line goes low (which
2677 indicated a CRC error).
2679 CONFIG_SYS_FPGA_WAIT_INIT
2681 Maximum time to wait for the INIT_B line to deassert
2682 after PROB_B has been deasserted during a Virtex II
2683 FPGA configuration sequence. The default time is 500
2686 CONFIG_SYS_FPGA_WAIT_BUSY
2688 Maximum time to wait for BUSY to deassert during
2689 Virtex II FPGA configuration. The default is 5 ms.
2691 CONFIG_SYS_FPGA_WAIT_CONFIG
2693 Time to wait after FPGA configuration. The default is
2696 - Configuration Management:
2699 If defined, this string will be added to the U-Boot
2700 version information (U_BOOT_VERSION)
2702 - Vendor Parameter Protection:
2704 U-Boot considers the values of the environment
2705 variables "serial#" (Board Serial Number) and
2706 "ethaddr" (Ethernet Address) to be parameters that
2707 are set once by the board vendor / manufacturer, and
2708 protects these variables from casual modification by
2709 the user. Once set, these variables are read-only,
2710 and write or delete attempts are rejected. You can
2711 change this behaviour:
2713 If CONFIG_ENV_OVERWRITE is #defined in your config
2714 file, the write protection for vendor parameters is
2715 completely disabled. Anybody can change or delete
2718 Alternatively, if you #define _both_ CONFIG_ETHADDR
2719 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2720 Ethernet address is installed in the environment,
2721 which can be changed exactly ONCE by the user. [The
2722 serial# is unaffected by this, i. e. it remains
2725 The same can be accomplished in a more flexible way
2726 for any variable by configuring the type of access
2727 to allow for those variables in the ".flags" variable
2728 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2733 Define this variable to enable the reservation of
2734 "protected RAM", i. e. RAM which is not overwritten
2735 by U-Boot. Define CONFIG_PRAM to hold the number of
2736 kB you want to reserve for pRAM. You can overwrite
2737 this default value by defining an environment
2738 variable "pram" to the number of kB you want to
2739 reserve. Note that the board info structure will
2740 still show the full amount of RAM. If pRAM is
2741 reserved, a new environment variable "mem" will
2742 automatically be defined to hold the amount of
2743 remaining RAM in a form that can be passed as boot
2744 argument to Linux, for instance like that:
2746 setenv bootargs ... mem=\${mem}
2749 This way you can tell Linux not to use this memory,
2750 either, which results in a memory region that will
2751 not be affected by reboots.
2753 *WARNING* If your board configuration uses automatic
2754 detection of the RAM size, you must make sure that
2755 this memory test is non-destructive. So far, the
2756 following board configurations are known to be
2759 IVMS8, IVML24, SPD8xx, TQM8xxL,
2760 HERMES, IP860, RPXlite, LWMON,
2763 - Access to physical memory region (> 4GB)
2764 Some basic support is provided for operations on memory not
2765 normally accessible to U-Boot - e.g. some architectures
2766 support access to more than 4GB of memory on 32-bit
2767 machines using physical address extension or similar.
2768 Define CONFIG_PHYSMEM to access this basic support, which
2769 currently only supports clearing the memory.
2774 Define this variable to stop the system in case of a
2775 fatal error, so that you have to reset it manually.
2776 This is probably NOT a good idea for an embedded
2777 system where you want the system to reboot
2778 automatically as fast as possible, but it may be
2779 useful during development since you can try to debug
2780 the conditions that lead to the situation.
2782 CONFIG_NET_RETRY_COUNT
2784 This variable defines the number of retries for
2785 network operations like ARP, RARP, TFTP, or BOOTP
2786 before giving up the operation. If not defined, a
2787 default value of 5 is used.
2791 Timeout waiting for an ARP reply in milliseconds.
2795 Timeout in milliseconds used in NFS protocol.
2796 If you encounter "ERROR: Cannot umount" in nfs command,
2797 try longer timeout such as
2798 #define CONFIG_NFS_TIMEOUT 10000UL
2800 - Command Interpreter:
2801 CONFIG_AUTO_COMPLETE
2803 Enable auto completion of commands using TAB.
2805 Note that this feature has NOT been implemented yet
2806 for the "hush" shell.
2809 CONFIG_SYS_HUSH_PARSER
2811 Define this variable to enable the "hush" shell (from
2812 Busybox) as command line interpreter, thus enabling
2813 powerful command line syntax like
2814 if...then...else...fi conditionals or `&&' and '||'
2815 constructs ("shell scripts").
2817 If undefined, you get the old, much simpler behaviour
2818 with a somewhat smaller memory footprint.
2821 CONFIG_SYS_PROMPT_HUSH_PS2
2823 This defines the secondary prompt string, which is
2824 printed when the command interpreter needs more input
2825 to complete a command. Usually "> ".
2829 In the current implementation, the local variables
2830 space and global environment variables space are
2831 separated. Local variables are those you define by
2832 simply typing `name=value'. To access a local
2833 variable later on, you have write `$name' or
2834 `${name}'; to execute the contents of a variable
2835 directly type `$name' at the command prompt.
2837 Global environment variables are those you use
2838 setenv/printenv to work with. To run a command stored
2839 in such a variable, you need to use the run command,
2840 and you must not use the '$' sign to access them.
2842 To store commands and special characters in a
2843 variable, please use double quotation marks
2844 surrounding the whole text of the variable, instead
2845 of the backslashes before semicolons and special
2848 - Commandline Editing and History:
2849 CONFIG_CMDLINE_EDITING
2851 Enable editing and History functions for interactive
2852 commandline input operations
2854 - Default Environment:
2855 CONFIG_EXTRA_ENV_SETTINGS
2857 Define this to contain any number of null terminated
2858 strings (variable = value pairs) that will be part of
2859 the default environment compiled into the boot image.
2861 For example, place something like this in your
2862 board's config file:
2864 #define CONFIG_EXTRA_ENV_SETTINGS \
2868 Warning: This method is based on knowledge about the
2869 internal format how the environment is stored by the
2870 U-Boot code. This is NOT an official, exported
2871 interface! Although it is unlikely that this format
2872 will change soon, there is no guarantee either.
2873 You better know what you are doing here.
2875 Note: overly (ab)use of the default environment is
2876 discouraged. Make sure to check other ways to preset
2877 the environment like the "source" command or the
2880 CONFIG_ENV_VARS_UBOOT_CONFIG
2882 Define this in order to add variables describing the
2883 U-Boot build configuration to the default environment.
2884 These will be named arch, cpu, board, vendor, and soc.
2886 Enabling this option will cause the following to be defined:
2894 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2896 Define this in order to add variables describing certain
2897 run-time determined information about the hardware to the
2898 environment. These will be named board_name, board_rev.
2900 CONFIG_DELAY_ENVIRONMENT
2902 Normally the environment is loaded when the board is
2903 intialised so that it is available to U-Boot. This inhibits
2904 that so that the environment is not available until
2905 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2906 this is instead controlled by the value of
2907 /config/load-environment.
2909 - DataFlash Support:
2910 CONFIG_HAS_DATAFLASH
2912 Defining this option enables DataFlash features and
2913 allows to read/write in Dataflash via the standard
2916 - Serial Flash support
2919 Defining this option enables SPI flash commands
2920 'sf probe/read/write/erase/update'.
2922 Usage requires an initial 'probe' to define the serial
2923 flash parameters, followed by read/write/erase/update
2926 The following defaults may be provided by the platform
2927 to handle the common case when only a single serial
2928 flash is present on the system.
2930 CONFIG_SF_DEFAULT_BUS Bus identifier
2931 CONFIG_SF_DEFAULT_CS Chip-select
2932 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2933 CONFIG_SF_DEFAULT_SPEED in Hz
2937 Define this option to include a destructive SPI flash
2940 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2942 Define this option to use the Bank addr/Extended addr
2943 support on SPI flashes which has size > 16Mbytes.
2945 CONFIG_SF_DUAL_FLASH Dual flash memories
2947 Define this option to use dual flash support where two flash
2948 memories can be connected with a given cs line.
2949 currently Xilinx Zynq qspi support these type of connections.
2951 - SystemACE Support:
2954 Adding this option adds support for Xilinx SystemACE
2955 chips attached via some sort of local bus. The address
2956 of the chip must also be defined in the
2957 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2959 #define CONFIG_SYSTEMACE
2960 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2962 When SystemACE support is added, the "ace" device type
2963 becomes available to the fat commands, i.e. fatls.
2965 - TFTP Fixed UDP Port:
2968 If this is defined, the environment variable tftpsrcp
2969 is used to supply the TFTP UDP source port value.
2970 If tftpsrcp isn't defined, the normal pseudo-random port
2971 number generator is used.
2973 Also, the environment variable tftpdstp is used to supply
2974 the TFTP UDP destination port value. If tftpdstp isn't
2975 defined, the normal port 69 is used.
2977 The purpose for tftpsrcp is to allow a TFTP server to
2978 blindly start the TFTP transfer using the pre-configured
2979 target IP address and UDP port. This has the effect of
2980 "punching through" the (Windows XP) firewall, allowing
2981 the remainder of the TFTP transfer to proceed normally.
2982 A better solution is to properly configure the firewall,
2983 but sometimes that is not allowed.
2988 This enables a generic 'hash' command which can produce
2989 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2993 Enable the hash verify command (hash -v). This adds to code
2996 CONFIG_SHA1 - support SHA1 hashing
2997 CONFIG_SHA256 - support SHA256 hashing
2999 Note: There is also a sha1sum command, which should perhaps
3000 be deprecated in favour of 'hash sha1'.
3002 - Freescale i.MX specific commands:
3003 CONFIG_CMD_HDMIDETECT
3004 This enables 'hdmidet' command which returns true if an
3005 HDMI monitor is detected. This command is i.MX 6 specific.
3008 This enables the 'bmode' (bootmode) command for forcing
3009 a boot from specific media.
3011 This is useful for forcing the ROM's usb downloader to
3012 activate upon a watchdog reset which is nice when iterating
3013 on U-Boot. Using the reset button or running bmode normal
3014 will set it back to normal. This command currently
3015 supports i.MX53 and i.MX6.
3020 This enables the RSA algorithm used for FIT image verification
3021 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3023 The signing part is build into mkimage regardless of this
3026 - bootcount support:
3027 CONFIG_BOOTCOUNT_LIMIT
3029 This enables the bootcounter support, see:
3030 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3033 enable special bootcounter support on at91sam9xe based boards.
3035 enable special bootcounter support on blackfin based boards.
3037 enable special bootcounter support on da850 based boards.
3038 CONFIG_BOOTCOUNT_RAM
3039 enable support for the bootcounter in RAM
3040 CONFIG_BOOTCOUNT_I2C
3041 enable support for the bootcounter on an i2c (like RTC) device.
3042 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3043 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3045 CONFIG_BOOTCOUNT_ALEN = address len
3047 - Show boot progress:
3048 CONFIG_SHOW_BOOT_PROGRESS
3050 Defining this option allows to add some board-
3051 specific code (calling a user-provided function
3052 "show_boot_progress(int)") that enables you to show
3053 the system's boot progress on some display (for
3054 example, some LED's) on your board. At the moment,
3055 the following checkpoints are implemented:
3057 - Detailed boot stage timing
3059 Define this option to get detailed timing of each stage
3060 of the boot process.
3062 CONFIG_BOOTSTAGE_USER_COUNT
3063 This is the number of available user bootstage records.
3064 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3065 a new ID will be allocated from this stash. If you exceed
3066 the limit, recording will stop.
3068 CONFIG_BOOTSTAGE_REPORT
3069 Define this to print a report before boot, similar to this:
3071 Timer summary in microseconds:
3074 3,575,678 3,575,678 board_init_f start
3075 3,575,695 17 arch_cpu_init A9
3076 3,575,777 82 arch_cpu_init done
3077 3,659,598 83,821 board_init_r start
3078 3,910,375 250,777 main_loop
3079 29,916,167 26,005,792 bootm_start
3080 30,361,327 445,160 start_kernel
3082 CONFIG_CMD_BOOTSTAGE
3083 Add a 'bootstage' command which supports printing a report
3084 and un/stashing of bootstage data.
3086 CONFIG_BOOTSTAGE_FDT
3087 Stash the bootstage information in the FDT. A root 'bootstage'
3088 node is created with each bootstage id as a child. Each child
3089 has a 'name' property and either 'mark' containing the
3090 mark time in microsecond, or 'accum' containing the
3091 accumulated time for that bootstage id in microseconds.
3096 name = "board_init_f";
3105 Code in the Linux kernel can find this in /proc/devicetree.
3107 Legacy uImage format:
3110 1 common/cmd_bootm.c before attempting to boot an image
3111 -1 common/cmd_bootm.c Image header has bad magic number
3112 2 common/cmd_bootm.c Image header has correct magic number
3113 -2 common/cmd_bootm.c Image header has bad checksum
3114 3 common/cmd_bootm.c Image header has correct checksum
3115 -3 common/cmd_bootm.c Image data has bad checksum
3116 4 common/cmd_bootm.c Image data has correct checksum
3117 -4 common/cmd_bootm.c Image is for unsupported architecture
3118 5 common/cmd_bootm.c Architecture check OK
3119 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3120 6 common/cmd_bootm.c Image Type check OK
3121 -6 common/cmd_bootm.c gunzip uncompression error
3122 -7 common/cmd_bootm.c Unimplemented compression type
3123 7 common/cmd_bootm.c Uncompression OK
3124 8 common/cmd_bootm.c No uncompress/copy overwrite error
3125 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3127 9 common/image.c Start initial ramdisk verification
3128 -10 common/image.c Ramdisk header has bad magic number
3129 -11 common/image.c Ramdisk header has bad checksum
3130 10 common/image.c Ramdisk header is OK
3131 -12 common/image.c Ramdisk data has bad checksum
3132 11 common/image.c Ramdisk data has correct checksum
3133 12 common/image.c Ramdisk verification complete, start loading
3134 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3135 13 common/image.c Start multifile image verification
3136 14 common/image.c No initial ramdisk, no multifile, continue.
3138 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3140 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3141 -31 post/post.c POST test failed, detected by post_output_backlog()
3142 -32 post/post.c POST test failed, detected by post_run_single()
3144 34 common/cmd_doc.c before loading a Image from a DOC device
3145 -35 common/cmd_doc.c Bad usage of "doc" command
3146 35 common/cmd_doc.c correct usage of "doc" command
3147 -36 common/cmd_doc.c No boot device
3148 36 common/cmd_doc.c correct boot device
3149 -37 common/cmd_doc.c Unknown Chip ID on boot device
3150 37 common/cmd_doc.c correct chip ID found, device available
3151 -38 common/cmd_doc.c Read Error on boot device
3152 38 common/cmd_doc.c reading Image header from DOC device OK
3153 -39 common/cmd_doc.c Image header has bad magic number
3154 39 common/cmd_doc.c Image header has correct magic number
3155 -40 common/cmd_doc.c Error reading Image from DOC device
3156 40 common/cmd_doc.c Image header has correct magic number
3157 41 common/cmd_ide.c before loading a Image from a IDE device
3158 -42 common/cmd_ide.c Bad usage of "ide" command
3159 42 common/cmd_ide.c correct usage of "ide" command
3160 -43 common/cmd_ide.c No boot device
3161 43 common/cmd_ide.c boot device found
3162 -44 common/cmd_ide.c Device not available
3163 44 common/cmd_ide.c Device available
3164 -45 common/cmd_ide.c wrong partition selected
3165 45 common/cmd_ide.c partition selected
3166 -46 common/cmd_ide.c Unknown partition table
3167 46 common/cmd_ide.c valid partition table found
3168 -47 common/cmd_ide.c Invalid partition type
3169 47 common/cmd_ide.c correct partition type
3170 -48 common/cmd_ide.c Error reading Image Header on boot device
3171 48 common/cmd_ide.c reading Image Header from IDE device OK
3172 -49 common/cmd_ide.c Image header has bad magic number
3173 49 common/cmd_ide.c Image header has correct magic number
3174 -50 common/cmd_ide.c Image header has bad checksum
3175 50 common/cmd_ide.c Image header has correct checksum
3176 -51 common/cmd_ide.c Error reading Image from IDE device
3177 51 common/cmd_ide.c reading Image from IDE device OK
3178 52 common/cmd_nand.c before loading a Image from a NAND device
3179 -53 common/cmd_nand.c Bad usage of "nand" command
3180 53 common/cmd_nand.c correct usage of "nand" command
3181 -54 common/cmd_nand.c No boot device
3182 54 common/cmd_nand.c boot device found
3183 -55 common/cmd_nand.c Unknown Chip ID on boot device
3184 55 common/cmd_nand.c correct chip ID found, device available
3185 -56 common/cmd_nand.c Error reading Image Header on boot device
3186 56 common/cmd_nand.c reading Image Header from NAND device OK
3187 -57 common/cmd_nand.c Image header has bad magic number
3188 57 common/cmd_nand.c Image header has correct magic number
3189 -58 common/cmd_nand.c Error reading Image from NAND device
3190 58 common/cmd_nand.c reading Image from NAND device OK
3192 -60 common/env_common.c Environment has a bad CRC, using default
3194 64 net/eth.c starting with Ethernet configuration.
3195 -64 net/eth.c no Ethernet found.
3196 65 net/eth.c Ethernet found.
3198 -80 common/cmd_net.c usage wrong
3199 80 common/cmd_net.c before calling NetLoop()
3200 -81 common/cmd_net.c some error in NetLoop() occurred
3201 81 common/cmd_net.c NetLoop() back without error
3202 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3203 82 common/cmd_net.c trying automatic boot
3204 83 common/cmd_net.c running "source" command
3205 -83 common/cmd_net.c some error in automatic boot or "source" command
3206 84 common/cmd_net.c end without errors
3211 100 common/cmd_bootm.c Kernel FIT Image has correct format
3212 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3213 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3214 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3215 102 common/cmd_bootm.c Kernel unit name specified
3216 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3217 103 common/cmd_bootm.c Found configuration node
3218 104 common/cmd_bootm.c Got kernel subimage node offset
3219 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3220 105 common/cmd_bootm.c Kernel subimage hash verification OK
3221 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3222 106 common/cmd_bootm.c Architecture check OK
3223 -106 common/cmd_bootm.c Kernel subimage has wrong type
3224 107 common/cmd_bootm.c Kernel subimage type OK
3225 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3226 108 common/cmd_bootm.c Got kernel subimage data/size
3227 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3228 -109 common/cmd_bootm.c Can't get kernel subimage type
3229 -110 common/cmd_bootm.c Can't get kernel subimage comp
3230 -111 common/cmd_bootm.c Can't get kernel subimage os
3231 -112 common/cmd_bootm.c Can't get kernel subimage load address
3232 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3234 120 common/image.c Start initial ramdisk verification
3235 -120 common/image.c Ramdisk FIT image has incorrect format
3236 121 common/image.c Ramdisk FIT image has correct format
3237 122 common/image.c No ramdisk subimage unit name, using configuration
3238 -122 common/image.c Can't get configuration for ramdisk subimage
3239 123 common/image.c Ramdisk unit name specified
3240 -124 common/image.c Can't get ramdisk subimage node offset
3241 125 common/image.c Got ramdisk subimage node offset
3242 -125 common/image.c Ramdisk subimage hash verification failed
3243 126 common/image.c Ramdisk subimage hash verification OK
3244 -126 common/image.c Ramdisk subimage for unsupported architecture
3245 127 common/image.c Architecture check OK
3246 -127 common/image.c Can't get ramdisk subimage data/size
3247 128 common/image.c Got ramdisk subimage data/size
3248 129 common/image.c Can't get ramdisk load address
3249 -129 common/image.c Got ramdisk load address
3251 -130 common/cmd_doc.c Incorrect FIT image format
3252 131 common/cmd_doc.c FIT image format OK
3254 -140 common/cmd_ide.c Incorrect FIT image format
3255 141 common/cmd_ide.c FIT image format OK
3257 -150 common/cmd_nand.c Incorrect FIT image format
3258 151 common/cmd_nand.c FIT image format OK
3260 - legacy image format:
3261 CONFIG_IMAGE_FORMAT_LEGACY
3262 enables the legacy image format support in U-Boot.
3265 enabled if CONFIG_FIT_SIGNATURE is not defined.
3267 CONFIG_DISABLE_IMAGE_LEGACY
3268 disable the legacy image format
3270 This define is introduced, as the legacy image format is
3271 enabled per default for backward compatibility.
3273 - FIT image support:
3275 Enable support for the FIT uImage format.
3277 CONFIG_FIT_BEST_MATCH
3278 When no configuration is explicitly selected, default to the
3279 one whose fdt's compatibility field best matches that of
3280 U-Boot itself. A match is considered "best" if it matches the
3281 most specific compatibility entry of U-Boot's fdt's root node.
3282 The order of entries in the configuration's fdt is ignored.
3284 CONFIG_FIT_SIGNATURE
3285 This option enables signature verification of FIT uImages,
3286 using a hash signed and verified using RSA. See
3287 doc/uImage.FIT/signature.txt for more details.
3289 WARNING: When relying on signed FIT images with required
3290 signature check the legacy image format is default
3291 disabled. If a board need legacy image format support
3292 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3294 CONFIG_FIT_DISABLE_SHA256
3295 Supporting SHA256 hashes has quite an impact on binary size.
3296 For constrained systems sha256 hash support can be disabled
3299 - Standalone program support:
3300 CONFIG_STANDALONE_LOAD_ADDR
3302 This option defines a board specific value for the
3303 address where standalone program gets loaded, thus
3304 overwriting the architecture dependent default
3307 - Frame Buffer Address:
3310 Define CONFIG_FB_ADDR if you want to use specific
3311 address for frame buffer. This is typically the case
3312 when using a graphics controller has separate video
3313 memory. U-Boot will then place the frame buffer at
3314 the given address instead of dynamically reserving it
3315 in system RAM by calling lcd_setmem(), which grabs
3316 the memory for the frame buffer depending on the
3317 configured panel size.
3319 Please see board_init_f function.
3321 - Automatic software updates via TFTP server
3323 CONFIG_UPDATE_TFTP_CNT_MAX
3324 CONFIG_UPDATE_TFTP_MSEC_MAX
3326 These options enable and control the auto-update feature;
3327 for a more detailed description refer to doc/README.update.
3329 - MTD Support (mtdparts command, UBI support)
3332 Adds the MTD device infrastructure from the Linux kernel.
3333 Needed for mtdparts command support.
3335 CONFIG_MTD_PARTITIONS
3337 Adds the MTD partitioning infrastructure from the Linux
3338 kernel. Needed for UBI support.
3343 Adds commands for interacting with MTD partitions formatted
3344 with the UBI flash translation layer
3346 Requires also defining CONFIG_RBTREE
3348 CONFIG_UBI_SILENCE_MSG
3350 Make the verbose messages from UBI stop printing. This leaves
3351 warnings and errors enabled.
3356 Adds commands for interacting with UBI volumes formatted as
3357 UBIFS. UBIFS is read-only in u-boot.
3359 Requires UBI support as well as CONFIG_LZO
3361 CONFIG_UBIFS_SILENCE_MSG
3363 Make the verbose messages from UBIFS stop printing. This leaves
3364 warnings and errors enabled.
3368 Enable building of SPL globally.
3371 LDSCRIPT for linking the SPL binary.
3373 CONFIG_SPL_MAX_FOOTPRINT
3374 Maximum size in memory allocated to the SPL, BSS included.
3375 When defined, the linker checks that the actual memory
3376 used by SPL from _start to __bss_end does not exceed it.
3377 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3378 must not be both defined at the same time.
3381 Maximum size of the SPL image (text, data, rodata, and
3382 linker lists sections), BSS excluded.
3383 When defined, the linker checks that the actual size does
3386 CONFIG_SPL_TEXT_BASE
3387 TEXT_BASE for linking the SPL binary.
3389 CONFIG_SPL_RELOC_TEXT_BASE
3390 Address to relocate to. If unspecified, this is equal to
3391 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3393 CONFIG_SPL_BSS_START_ADDR
3394 Link address for the BSS within the SPL binary.
3396 CONFIG_SPL_BSS_MAX_SIZE
3397 Maximum size in memory allocated to the SPL BSS.
3398 When defined, the linker checks that the actual memory used
3399 by SPL from __bss_start to __bss_end does not exceed it.
3400 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3401 must not be both defined at the same time.
3404 Adress of the start of the stack SPL will use
3406 CONFIG_SPL_RELOC_STACK
3407 Adress of the start of the stack SPL will use after
3408 relocation. If unspecified, this is equal to
3411 CONFIG_SYS_SPL_MALLOC_START
3412 Starting address of the malloc pool used in SPL.
3414 CONFIG_SYS_SPL_MALLOC_SIZE
3415 The size of the malloc pool used in SPL.
3417 CONFIG_SPL_FRAMEWORK
3418 Enable the SPL framework under common/. This framework
3419 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3420 NAND loading of the Linux Kernel.
3423 Enable booting directly to an OS from SPL.
3424 See also: doc/README.falcon
3426 CONFIG_SPL_DISPLAY_PRINT
3427 For ARM, enable an optional function to print more information
3428 about the running system.
3430 CONFIG_SPL_INIT_MINIMAL
3431 Arch init code should be built for a very small image
3433 CONFIG_SPL_LIBCOMMON_SUPPORT
3434 Support for common/libcommon.o in SPL binary
3436 CONFIG_SPL_LIBDISK_SUPPORT
3437 Support for disk/libdisk.o in SPL binary
3439 CONFIG_SPL_I2C_SUPPORT
3440 Support for drivers/i2c/libi2c.o in SPL binary
3442 CONFIG_SPL_GPIO_SUPPORT
3443 Support for drivers/gpio/libgpio.o in SPL binary
3445 CONFIG_SPL_MMC_SUPPORT
3446 Support for drivers/mmc/libmmc.o in SPL binary
3448 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3449 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3450 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3451 Address, size and partition on the MMC to load U-Boot from
3452 when the MMC is being used in raw mode.
3454 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3455 Sector to load kernel uImage from when MMC is being
3456 used in raw mode (for Falcon mode)
3458 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3459 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3460 Sector and number of sectors to load kernel argument
3461 parameters from when MMC is being used in raw mode
3464 CONFIG_SPL_FAT_SUPPORT
3465 Support for fs/fat/libfat.o in SPL binary
3467 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3468 Filename to read to load U-Boot when reading from FAT
3470 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3471 Filename to read to load kernel uImage when reading
3472 from FAT (for Falcon mode)
3474 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3475 Filename to read to load kernel argument parameters
3476 when reading from FAT (for Falcon mode)
3478 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3479 Set this for NAND SPL on PPC mpc83xx targets, so that
3480 start.S waits for the rest of the SPL to load before
3481 continuing (the hardware starts execution after just
3482 loading the first page rather than the full 4K).
3484 CONFIG_SPL_SKIP_RELOCATE
3485 Avoid SPL relocation
3487 CONFIG_SPL_NAND_BASE
3488 Include nand_base.c in the SPL. Requires
3489 CONFIG_SPL_NAND_DRIVERS.
3491 CONFIG_SPL_NAND_DRIVERS
3492 SPL uses normal NAND drivers, not minimal drivers.
3495 Include standard software ECC in the SPL
3497 CONFIG_SPL_NAND_SIMPLE
3498 Support for NAND boot using simple NAND drivers that
3499 expose the cmd_ctrl() interface.
3501 CONFIG_SPL_MTD_SUPPORT
3502 Support for the MTD subsystem within SPL. Useful for
3503 environment on NAND support within SPL.
3505 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3506 Set for the SPL on PPC mpc8xxx targets, support for
3507 drivers/ddr/fsl/libddr.o in SPL binary.
3509 CONFIG_SPL_COMMON_INIT_DDR
3510 Set for common ddr init with serial presence detect in
3513 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3514 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3515 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3516 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3517 CONFIG_SYS_NAND_ECCBYTES
3518 Defines the size and behavior of the NAND that SPL uses
3521 CONFIG_SPL_NAND_BOOT
3522 Add support NAND boot
3524 CONFIG_SYS_NAND_U_BOOT_OFFS
3525 Location in NAND to read U-Boot from
3527 CONFIG_SYS_NAND_U_BOOT_DST
3528 Location in memory to load U-Boot to
3530 CONFIG_SYS_NAND_U_BOOT_SIZE
3531 Size of image to load
3533 CONFIG_SYS_NAND_U_BOOT_START
3534 Entry point in loaded image to jump to
3536 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3537 Define this if you need to first read the OOB and then the
3538 data. This is used for example on davinci plattforms.
3540 CONFIG_SPL_OMAP3_ID_NAND
3541 Support for an OMAP3-specific set of functions to return the
3542 ID and MFR of the first attached NAND chip, if present.
3544 CONFIG_SPL_SERIAL_SUPPORT
3545 Support for drivers/serial/libserial.o in SPL binary
3547 CONFIG_SPL_SPI_FLASH_SUPPORT
3548 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3550 CONFIG_SPL_SPI_SUPPORT
3551 Support for drivers/spi/libspi.o in SPL binary
3553 CONFIG_SPL_RAM_DEVICE
3554 Support for running image already present in ram, in SPL binary
3556 CONFIG_SPL_LIBGENERIC_SUPPORT
3557 Support for lib/libgeneric.o in SPL binary
3559 CONFIG_SPL_ENV_SUPPORT
3560 Support for the environment operating in SPL binary
3562 CONFIG_SPL_NET_SUPPORT
3563 Support for the net/libnet.o in SPL binary.
3564 It conflicts with SPL env from storage medium specified by
3565 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3568 Image offset to which the SPL should be padded before appending
3569 the SPL payload. By default, this is defined as
3570 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3571 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3572 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3575 Final target image containing SPL and payload. Some SPLs
3576 use an arch-specific makefile fragment instead, for
3577 example if more than one image needs to be produced.
3579 CONFIG_FIT_SPL_PRINT
3580 Printing information about a FIT image adds quite a bit of
3581 code to SPL. So this is normally disabled in SPL. Use this
3582 option to re-enable it. This will affect the output of the
3583 bootm command when booting a FIT image.
3587 Enable building of TPL globally.
3590 Image offset to which the TPL should be padded before appending
3591 the TPL payload. By default, this is defined as
3592 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3593 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3594 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3599 [so far only for SMDK2400 boards]
3601 - Modem support enable:
3602 CONFIG_MODEM_SUPPORT
3604 - RTS/CTS Flow control enable:
3607 - Modem debug support:
3608 CONFIG_MODEM_SUPPORT_DEBUG
3610 Enables debugging stuff (char screen[1024], dbg())
3611 for modem support. Useful only with BDI2000.
3613 - Interrupt support (PPC):
3615 There are common interrupt_init() and timer_interrupt()
3616 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3617 for CPU specific initialization. interrupt_init_cpu()
3618 should set decrementer_count to appropriate value. If
3619 CPU resets decrementer automatically after interrupt
3620 (ppc4xx) it should set decrementer_count to zero.
3621 timer_interrupt() calls timer_interrupt_cpu() for CPU
3622 specific handling. If board has watchdog / status_led
3623 / other_activity_monitor it works automatically from
3624 general timer_interrupt().
3628 In the target system modem support is enabled when a
3629 specific key (key combination) is pressed during
3630 power-on. Otherwise U-Boot will boot normally
3631 (autoboot). The key_pressed() function is called from
3632 board_init(). Currently key_pressed() is a dummy
3633 function, returning 1 and thus enabling modem
3636 If there are no modem init strings in the
3637 environment, U-Boot proceed to autoboot; the
3638 previous output (banner, info printfs) will be
3641 See also: doc/README.Modem
3643 Board initialization settings:
3644 ------------------------------
3646 During Initialization u-boot calls a number of board specific functions
3647 to allow the preparation of board specific prerequisites, e.g. pin setup
3648 before drivers are initialized. To enable these callbacks the
3649 following configuration macros have to be defined. Currently this is
3650 architecture specific, so please check arch/your_architecture/lib/board.c
3651 typically in board_init_f() and board_init_r().
3653 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3654 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3655 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3656 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3658 Configuration Settings:
3659 -----------------------
3661 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3662 Optionally it can be defined to support 64-bit memory commands.
3664 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3665 undefine this when you're short of memory.
3667 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3668 width of the commands listed in the 'help' command output.
3670 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3671 prompt for user input.
3673 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3675 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3677 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3679 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3680 the application (usually a Linux kernel) when it is
3683 - CONFIG_SYS_BAUDRATE_TABLE:
3684 List of legal baudrate settings for this board.
3686 - CONFIG_SYS_CONSOLE_INFO_QUIET
3687 Suppress display of console information at boot.
3689 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3690 If the board specific function
3691 extern int overwrite_console (void);
3692 returns 1, the stdin, stderr and stdout are switched to the
3693 serial port, else the settings in the environment are used.
3695 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3696 Enable the call to overwrite_console().
3698 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3699 Enable overwrite of previous console environment settings.
3701 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3702 Begin and End addresses of the area used by the
3705 - CONFIG_SYS_ALT_MEMTEST:
3706 Enable an alternate, more extensive memory test.
3708 - CONFIG_SYS_MEMTEST_SCRATCH:
3709 Scratch address used by the alternate memory test
3710 You only need to set this if address zero isn't writeable
3712 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3713 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3714 this specified memory area will get subtracted from the top
3715 (end) of RAM and won't get "touched" at all by U-Boot. By
3716 fixing up gd->ram_size the Linux kernel should gets passed
3717 the now "corrected" memory size and won't touch it either.
3718 This should work for arch/ppc and arch/powerpc. Only Linux
3719 board ports in arch/powerpc with bootwrapper support that
3720 recalculate the memory size from the SDRAM controller setup
3721 will have to get fixed in Linux additionally.
3723 This option can be used as a workaround for the 440EPx/GRx
3724 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3727 WARNING: Please make sure that this value is a multiple of
3728 the Linux page size (normally 4k). If this is not the case,
3729 then the end address of the Linux memory will be located at a
3730 non page size aligned address and this could cause major
3733 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3734 Enable temporary baudrate change while serial download
3736 - CONFIG_SYS_SDRAM_BASE:
3737 Physical start address of SDRAM. _Must_ be 0 here.
3739 - CONFIG_SYS_MBIO_BASE:
3740 Physical start address of Motherboard I/O (if using a
3743 - CONFIG_SYS_FLASH_BASE:
3744 Physical start address of Flash memory.
3746 - CONFIG_SYS_MONITOR_BASE:
3747 Physical start address of boot monitor code (set by
3748 make config files to be same as the text base address
3749 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3750 CONFIG_SYS_FLASH_BASE when booting from flash.
3752 - CONFIG_SYS_MONITOR_LEN:
3753 Size of memory reserved for monitor code, used to
3754 determine _at_compile_time_ (!) if the environment is
3755 embedded within the U-Boot image, or in a separate
3758 - CONFIG_SYS_MALLOC_LEN:
3759 Size of DRAM reserved for malloc() use.
3761 - CONFIG_SYS_MALLOC_F_LEN
3762 Size of the malloc() pool for use before relocation. If
3763 this is defined, then a very simple malloc() implementation
3764 will become available before relocation. The address is just
3765 below the global data, and the stack is moved down to make
3768 This feature allocates regions with increasing addresses
3769 within the region. calloc() is supported, but realloc()
3770 is not available. free() is supported but does nothing.
3771 The memory will be freed (or in fact just forgotton) when
3772 U-Boot relocates itself.
3774 Pre-relocation malloc() is only supported on sandbox
3775 at present but is fairly easy to enable for other archs.
3777 Pre-relocation malloc() is only supported on ARM at present
3778 but is fairly easy to enable for other archs.
3780 - CONFIG_SYS_BOOTM_LEN:
3781 Normally compressed uImages are limited to an
3782 uncompressed size of 8 MBytes. If this is not enough,
3783 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3784 to adjust this setting to your needs.
3786 - CONFIG_SYS_BOOTMAPSZ:
3787 Maximum size of memory mapped by the startup code of
3788 the Linux kernel; all data that must be processed by
3789 the Linux kernel (bd_info, boot arguments, FDT blob if
3790 used) must be put below this limit, unless "bootm_low"
3791 environment variable is defined and non-zero. In such case
3792 all data for the Linux kernel must be between "bootm_low"
3793 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3794 variable "bootm_mapsize" will override the value of
3795 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3796 then the value in "bootm_size" will be used instead.
3798 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3799 Enable initrd_high functionality. If defined then the
3800 initrd_high feature is enabled and the bootm ramdisk subcommand
3803 - CONFIG_SYS_BOOT_GET_CMDLINE:
3804 Enables allocating and saving kernel cmdline in space between
3805 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3807 - CONFIG_SYS_BOOT_GET_KBD:
3808 Enables allocating and saving a kernel copy of the bd_info in
3809 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3811 - CONFIG_SYS_MAX_FLASH_BANKS:
3812 Max number of Flash memory banks
3814 - CONFIG_SYS_MAX_FLASH_SECT:
3815 Max number of sectors on a Flash chip
3817 - CONFIG_SYS_FLASH_ERASE_TOUT:
3818 Timeout for Flash erase operations (in ms)
3820 - CONFIG_SYS_FLASH_WRITE_TOUT:
3821 Timeout for Flash write operations (in ms)
3823 - CONFIG_SYS_FLASH_LOCK_TOUT
3824 Timeout for Flash set sector lock bit operation (in ms)
3826 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3827 Timeout for Flash clear lock bits operation (in ms)
3829 - CONFIG_SYS_FLASH_PROTECTION
3830 If defined, hardware flash sectors protection is used
3831 instead of U-Boot software protection.
3833 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3835 Enable TFTP transfers directly to flash memory;
3836 without this option such a download has to be
3837 performed in two steps: (1) download to RAM, and (2)
3838 copy from RAM to flash.
3840 The two-step approach is usually more reliable, since
3841 you can check if the download worked before you erase
3842 the flash, but in some situations (when system RAM is
3843 too limited to allow for a temporary copy of the
3844 downloaded image) this option may be very useful.
3846 - CONFIG_SYS_FLASH_CFI:
3847 Define if the flash driver uses extra elements in the
3848 common flash structure for storing flash geometry.
3850 - CONFIG_FLASH_CFI_DRIVER
3851 This option also enables the building of the cfi_flash driver
3852 in the drivers directory
3854 - CONFIG_FLASH_CFI_MTD
3855 This option enables the building of the cfi_mtd driver
3856 in the drivers directory. The driver exports CFI flash
3859 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3860 Use buffered writes to flash.
3862 - CONFIG_FLASH_SPANSION_S29WS_N
3863 s29ws-n MirrorBit flash has non-standard addresses for buffered
3866 - CONFIG_SYS_FLASH_QUIET_TEST
3867 If this option is defined, the common CFI flash doesn't
3868 print it's warning upon not recognized FLASH banks. This
3869 is useful, if some of the configured banks are only
3870 optionally available.
3872 - CONFIG_FLASH_SHOW_PROGRESS
3873 If defined (must be an integer), print out countdown
3874 digits and dots. Recommended value: 45 (9..1) for 80
3875 column displays, 15 (3..1) for 40 column displays.
3877 - CONFIG_FLASH_VERIFY
3878 If defined, the content of the flash (destination) is compared
3879 against the source after the write operation. An error message
3880 will be printed when the contents are not identical.
3881 Please note that this option is useless in nearly all cases,
3882 since such flash programming errors usually are detected earlier
3883 while unprotecting/erasing/programming. Please only enable
3884 this option if you really know what you are doing.
3886 - CONFIG_SYS_RX_ETH_BUFFER:
3887 Defines the number of Ethernet receive buffers. On some
3888 Ethernet controllers it is recommended to set this value
3889 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3890 buffers can be full shortly after enabling the interface
3891 on high Ethernet traffic.
3892 Defaults to 4 if not defined.
3894 - CONFIG_ENV_MAX_ENTRIES
3896 Maximum number of entries in the hash table that is used
3897 internally to store the environment settings. The default
3898 setting is supposed to be generous and should work in most
3899 cases. This setting can be used to tune behaviour; see
3900 lib/hashtable.c for details.
3902 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3903 - CONFIG_ENV_FLAGS_LIST_STATIC
3904 Enable validation of the values given to environment variables when
3905 calling env set. Variables can be restricted to only decimal,
3906 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3907 the variables can also be restricted to IP address or MAC address.
3909 The format of the list is:
3910 type_attribute = [s|d|x|b|i|m]
3911 access_atribute = [a|r|o|c]
3912 attributes = type_attribute[access_atribute]
3913 entry = variable_name[:attributes]
3916 The type attributes are:
3917 s - String (default)
3920 b - Boolean ([1yYtT|0nNfF])
3924 The access attributes are:
3930 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3931 Define this to a list (string) to define the ".flags"
3932 envirnoment variable in the default or embedded environment.
3934 - CONFIG_ENV_FLAGS_LIST_STATIC
3935 Define this to a list (string) to define validation that
3936 should be done if an entry is not found in the ".flags"
3937 environment variable. To override a setting in the static
3938 list, simply add an entry for the same variable name to the
3941 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3942 If defined, don't allow the -f switch to env set override variable
3945 - CONFIG_SYS_GENERIC_BOARD
3946 This selects the architecture-generic board system instead of the
3947 architecture-specific board files. It is intended to move boards
3948 to this new framework over time. Defining this will disable the
3949 arch/foo/lib/board.c file and use common/board_f.c and
3950 common/board_r.c instead. To use this option your architecture
3951 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3952 its config.mk file). If you find problems enabling this option on
3953 your board please report the problem and send patches!
3955 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3956 This is set by OMAP boards for the max time that reset should
3957 be asserted. See doc/README.omap-reset-time for details on how
3958 the value can be calulated on a given board.
3960 The following definitions that deal with the placement and management
3961 of environment data (variable area); in general, we support the
3962 following configurations:
3964 - CONFIG_BUILD_ENVCRC:
3966 Builds up envcrc with the target environment so that external utils
3967 may easily extract it and embed it in final U-Boot images.
3969 - CONFIG_ENV_IS_IN_FLASH:
3971 Define this if the environment is in flash memory.
3973 a) The environment occupies one whole flash sector, which is
3974 "embedded" in the text segment with the U-Boot code. This
3975 happens usually with "bottom boot sector" or "top boot
3976 sector" type flash chips, which have several smaller
3977 sectors at the start or the end. For instance, such a
3978 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3979 such a case you would place the environment in one of the
3980 4 kB sectors - with U-Boot code before and after it. With
3981 "top boot sector" type flash chips, you would put the
3982 environment in one of the last sectors, leaving a gap
3983 between U-Boot and the environment.
3985 - CONFIG_ENV_OFFSET:
3987 Offset of environment data (variable area) to the
3988 beginning of flash memory; for instance, with bottom boot
3989 type flash chips the second sector can be used: the offset
3990 for this sector is given here.
3992 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3996 This is just another way to specify the start address of
3997 the flash sector containing the environment (instead of
4000 - CONFIG_ENV_SECT_SIZE:
4002 Size of the sector containing the environment.
4005 b) Sometimes flash chips have few, equal sized, BIG sectors.
4006 In such a case you don't want to spend a whole sector for
4011 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
4012 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
4013 of this flash sector for the environment. This saves
4014 memory for the RAM copy of the environment.
4016 It may also save flash memory if you decide to use this
4017 when your environment is "embedded" within U-Boot code,
4018 since then the remainder of the flash sector could be used
4019 for U-Boot code. It should be pointed out that this is
4020 STRONGLY DISCOURAGED from a robustness point of view:
4021 updating the environment in flash makes it always
4022 necessary to erase the WHOLE sector. If something goes
4023 wrong before the contents has been restored from a copy in
4024 RAM, your target system will be dead.
4026 - CONFIG_ENV_ADDR_REDUND
4027 CONFIG_ENV_SIZE_REDUND
4029 These settings describe a second storage area used to hold
4030 a redundant copy of the environment data, so that there is
4031 a valid backup copy in case there is a power failure during
4032 a "saveenv" operation.
4034 BE CAREFUL! Any changes to the flash layout, and some changes to the
4035 source code will make it necessary to adapt <board>/u-boot.lds*
4039 - CONFIG_ENV_IS_IN_NVRAM:
4041 Define this if you have some non-volatile memory device
4042 (NVRAM, battery buffered SRAM) which you want to use for the
4048 These two #defines are used to determine the memory area you
4049 want to use for environment. It is assumed that this memory
4050 can just be read and written to, without any special
4053 BE CAREFUL! The first access to the environment happens quite early
4054 in U-Boot initalization (when we try to get the setting of for the
4055 console baudrate). You *MUST* have mapped your NVRAM area then, or
4058 Please note that even with NVRAM we still use a copy of the
4059 environment in RAM: we could work on NVRAM directly, but we want to
4060 keep settings there always unmodified except somebody uses "saveenv"
4061 to save the current settings.
4064 - CONFIG_ENV_IS_IN_EEPROM:
4066 Use this if you have an EEPROM or similar serial access
4067 device and a driver for it.
4069 - CONFIG_ENV_OFFSET:
4072 These two #defines specify the offset and size of the
4073 environment area within the total memory of your EEPROM.
4075 - CONFIG_SYS_I2C_EEPROM_ADDR:
4076 If defined, specified the chip address of the EEPROM device.
4077 The default address is zero.
4079 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4080 If defined, the number of bits used to address bytes in a
4081 single page in the EEPROM device. A 64 byte page, for example
4082 would require six bits.
4084 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4085 If defined, the number of milliseconds to delay between
4086 page writes. The default is zero milliseconds.
4088 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4089 The length in bytes of the EEPROM memory array address. Note
4090 that this is NOT the chip address length!
4092 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4093 EEPROM chips that implement "address overflow" are ones
4094 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4095 address and the extra bits end up in the "chip address" bit
4096 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4099 Note that we consider the length of the address field to
4100 still be one byte because the extra address bits are hidden
4101 in the chip address.
4103 - CONFIG_SYS_EEPROM_SIZE:
4104 The size in bytes of the EEPROM device.
4106 - CONFIG_ENV_EEPROM_IS_ON_I2C
4107 define this, if you have I2C and SPI activated, and your
4108 EEPROM, which holds the environment, is on the I2C bus.
4110 - CONFIG_I2C_ENV_EEPROM_BUS
4111 if you have an Environment on an EEPROM reached over
4112 I2C muxes, you can define here, how to reach this
4113 EEPROM. For example:
4115 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4117 EEPROM which holds the environment, is reached over
4118 a pca9547 i2c mux with address 0x70, channel 3.
4120 - CONFIG_ENV_IS_IN_DATAFLASH:
4122 Define this if you have a DataFlash memory device which you
4123 want to use for the environment.
4125 - CONFIG_ENV_OFFSET:
4129 These three #defines specify the offset and size of the
4130 environment area within the total memory of your DataFlash placed
4131 at the specified address.
4133 - CONFIG_ENV_IS_IN_SPI_FLASH:
4135 Define this if you have a SPI Flash memory device which you
4136 want to use for the environment.
4138 - CONFIG_ENV_OFFSET:
4141 These two #defines specify the offset and size of the
4142 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4143 aligned to an erase sector boundary.
4145 - CONFIG_ENV_SECT_SIZE:
4147 Define the SPI flash's sector size.
4149 - CONFIG_ENV_OFFSET_REDUND (optional):
4151 This setting describes a second storage area of CONFIG_ENV_SIZE
4152 size used to hold a redundant copy of the environment data, so
4153 that there is a valid backup copy in case there is a power failure
4154 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4155 aligned to an erase sector boundary.
4157 - CONFIG_ENV_SPI_BUS (optional):
4158 - CONFIG_ENV_SPI_CS (optional):
4160 Define the SPI bus and chip select. If not defined they will be 0.
4162 - CONFIG_ENV_SPI_MAX_HZ (optional):
4164 Define the SPI max work clock. If not defined then use 1MHz.
4166 - CONFIG_ENV_SPI_MODE (optional):
4168 Define the SPI work mode. If not defined then use SPI_MODE_3.
4170 - CONFIG_ENV_IS_IN_REMOTE:
4172 Define this if you have a remote memory space which you
4173 want to use for the local device's environment.
4178 These two #defines specify the address and size of the
4179 environment area within the remote memory space. The
4180 local device can get the environment from remote memory
4181 space by SRIO or PCIE links.
4183 BE CAREFUL! For some special cases, the local device can not use
4184 "saveenv" command. For example, the local device will get the
4185 environment stored in a remote NOR flash by SRIO or PCIE link,
4186 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4188 - CONFIG_ENV_IS_IN_NAND:
4190 Define this if you have a NAND device which you want to use
4191 for the environment.
4193 - CONFIG_ENV_OFFSET:
4196 These two #defines specify the offset and size of the environment
4197 area within the first NAND device. CONFIG_ENV_OFFSET must be
4198 aligned to an erase block boundary.
4200 - CONFIG_ENV_OFFSET_REDUND (optional):
4202 This setting describes a second storage area of CONFIG_ENV_SIZE
4203 size used to hold a redundant copy of the environment data, so
4204 that there is a valid backup copy in case there is a power failure
4205 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4206 aligned to an erase block boundary.
4208 - CONFIG_ENV_RANGE (optional):
4210 Specifies the length of the region in which the environment
4211 can be written. This should be a multiple of the NAND device's
4212 block size. Specifying a range with more erase blocks than
4213 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4214 the range to be avoided.
4216 - CONFIG_ENV_OFFSET_OOB (optional):
4218 Enables support for dynamically retrieving the offset of the
4219 environment from block zero's out-of-band data. The
4220 "nand env.oob" command can be used to record this offset.
4221 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4222 using CONFIG_ENV_OFFSET_OOB.
4224 - CONFIG_NAND_ENV_DST
4226 Defines address in RAM to which the nand_spl code should copy the
4227 environment. If redundant environment is used, it will be copied to
4228 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4230 - CONFIG_ENV_IS_IN_UBI:
4232 Define this if you have an UBI volume that you want to use for the
4233 environment. This has the benefit of wear-leveling the environment
4234 accesses, which is important on NAND.
4236 - CONFIG_ENV_UBI_PART:
4238 Define this to a string that is the mtd partition containing the UBI.
4240 - CONFIG_ENV_UBI_VOLUME:
4242 Define this to the name of the volume that you want to store the
4245 - CONFIG_ENV_UBI_VOLUME_REDUND:
4247 Define this to the name of another volume to store a second copy of
4248 the environment in. This will enable redundant environments in UBI.
4249 It is assumed that both volumes are in the same MTD partition.
4251 - CONFIG_UBI_SILENCE_MSG
4252 - CONFIG_UBIFS_SILENCE_MSG
4254 You will probably want to define these to avoid a really noisy system
4255 when storing the env in UBI.
4257 - CONFIG_ENV_IS_IN_FAT:
4258 Define this if you want to use the FAT file system for the environment.
4260 - FAT_ENV_INTERFACE:
4262 Define this to a string that is the name of the block device.
4264 - FAT_ENV_DEV_AND_PART:
4266 Define this to a string to specify the partition of the device. It can
4269 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4270 - "D:P": device D partition P. Error occurs if device D has no
4273 - "D" or "D:": device D partition 1 if device D has partition
4274 table, or the whole device D if has no partition
4276 - "D:auto": first partition in device D with bootable flag set.
4277 If none, first valid paratition in device D. If no
4278 partition table then means device D.
4282 It's a string of the FAT file name. This file use to store the
4286 This should be defined. Otherwise it cannot save the envrionment file.
4288 - CONFIG_ENV_IS_IN_MMC:
4290 Define this if you have an MMC device which you want to use for the
4293 - CONFIG_SYS_MMC_ENV_DEV:
4295 Specifies which MMC device the environment is stored in.
4297 - CONFIG_SYS_MMC_ENV_PART (optional):
4299 Specifies which MMC partition the environment is stored in. If not
4300 set, defaults to partition 0, the user area. Common values might be
4301 1 (first MMC boot partition), 2 (second MMC boot partition).
4303 - CONFIG_ENV_OFFSET:
4306 These two #defines specify the offset and size of the environment
4307 area within the specified MMC device.
4309 If offset is positive (the usual case), it is treated as relative to
4310 the start of the MMC partition. If offset is negative, it is treated
4311 as relative to the end of the MMC partition. This can be useful if
4312 your board may be fitted with different MMC devices, which have
4313 different sizes for the MMC partitions, and you always want the
4314 environment placed at the very end of the partition, to leave the
4315 maximum possible space before it, to store other data.
4317 These two values are in units of bytes, but must be aligned to an
4318 MMC sector boundary.
4320 - CONFIG_ENV_OFFSET_REDUND (optional):
4322 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4323 hold a redundant copy of the environment data. This provides a
4324 valid backup copy in case the other copy is corrupted, e.g. due
4325 to a power failure during a "saveenv" operation.
4327 This value may also be positive or negative; this is handled in the
4328 same way as CONFIG_ENV_OFFSET.
4330 This value is also in units of bytes, but must also be aligned to
4331 an MMC sector boundary.
4333 - CONFIG_ENV_SIZE_REDUND (optional):
4335 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4336 set. If this value is set, it must be set to the same value as
4339 - CONFIG_SYS_SPI_INIT_OFFSET
4341 Defines offset to the initial SPI buffer area in DPRAM. The
4342 area is used at an early stage (ROM part) if the environment
4343 is configured to reside in the SPI EEPROM: We need a 520 byte
4344 scratch DPRAM area. It is used between the two initialization
4345 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4346 to be a good choice since it makes it far enough from the
4347 start of the data area as well as from the stack pointer.
4349 Please note that the environment is read-only until the monitor
4350 has been relocated to RAM and a RAM copy of the environment has been
4351 created; also, when using EEPROM you will have to use getenv_f()
4352 until then to read environment variables.
4354 The environment is protected by a CRC32 checksum. Before the monitor
4355 is relocated into RAM, as a result of a bad CRC you will be working
4356 with the compiled-in default environment - *silently*!!! [This is
4357 necessary, because the first environment variable we need is the
4358 "baudrate" setting for the console - if we have a bad CRC, we don't
4359 have any device yet where we could complain.]
4361 Note: once the monitor has been relocated, then it will complain if
4362 the default environment is used; a new CRC is computed as soon as you
4363 use the "saveenv" command to store a valid environment.
4365 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4366 Echo the inverted Ethernet link state to the fault LED.
4368 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4369 also needs to be defined.
4371 - CONFIG_SYS_FAULT_MII_ADDR:
4372 MII address of the PHY to check for the Ethernet link state.
4374 - CONFIG_NS16550_MIN_FUNCTIONS:
4375 Define this if you desire to only have use of the NS16550_init
4376 and NS16550_putc functions for the serial driver located at
4377 drivers/serial/ns16550.c. This option is useful for saving
4378 space for already greatly restricted images, including but not
4379 limited to NAND_SPL configurations.
4381 - CONFIG_DISPLAY_BOARDINFO
4382 Display information about the board that U-Boot is running on
4383 when U-Boot starts up. The board function checkboard() is called
4386 - CONFIG_DISPLAY_BOARDINFO_LATE
4387 Similar to the previous option, but display this information
4388 later, once stdio is running and output goes to the LCD, if
4391 Low Level (hardware related) configuration options:
4392 ---------------------------------------------------
4394 - CONFIG_SYS_CACHELINE_SIZE:
4395 Cache Line Size of the CPU.
4397 - CONFIG_SYS_DEFAULT_IMMR:
4398 Default address of the IMMR after system reset.
4400 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4401 and RPXsuper) to be able to adjust the position of
4402 the IMMR register after a reset.
4404 - CONFIG_SYS_CCSRBAR_DEFAULT:
4405 Default (power-on reset) physical address of CCSR on Freescale
4408 - CONFIG_SYS_CCSRBAR:
4409 Virtual address of CCSR. On a 32-bit build, this is typically
4410 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4412 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4413 for cross-platform code that uses that macro instead.
4415 - CONFIG_SYS_CCSRBAR_PHYS:
4416 Physical address of CCSR. CCSR can be relocated to a new
4417 physical address, if desired. In this case, this macro should
4418 be set to that address. Otherwise, it should be set to the
4419 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4420 is typically relocated on 36-bit builds. It is recommended
4421 that this macro be defined via the _HIGH and _LOW macros:
4423 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4424 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4426 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4427 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4428 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4429 used in assembly code, so it must not contain typecasts or
4430 integer size suffixes (e.g. "ULL").
4432 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4433 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4434 used in assembly code, so it must not contain typecasts or
4435 integer size suffixes (e.g. "ULL").
4437 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4438 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4439 forced to a value that ensures that CCSR is not relocated.
4441 - Floppy Disk Support:
4442 CONFIG_SYS_FDC_DRIVE_NUMBER
4444 the default drive number (default value 0)
4446 CONFIG_SYS_ISA_IO_STRIDE
4448 defines the spacing between FDC chipset registers
4451 CONFIG_SYS_ISA_IO_OFFSET
4453 defines the offset of register from address. It
4454 depends on which part of the data bus is connected to
4455 the FDC chipset. (default value 0)
4457 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4458 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4461 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4462 fdc_hw_init() is called at the beginning of the FDC
4463 setup. fdc_hw_init() must be provided by the board
4464 source code. It is used to make hardware dependant
4468 Most IDE controllers were designed to be connected with PCI
4469 interface. Only few of them were designed for AHB interface.
4470 When software is doing ATA command and data transfer to
4471 IDE devices through IDE-AHB controller, some additional
4472 registers accessing to these kind of IDE-AHB controller
4475 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4476 DO NOT CHANGE unless you know exactly what you're
4477 doing! (11-4) [MPC8xx/82xx systems only]
4479 - CONFIG_SYS_INIT_RAM_ADDR:
4481 Start address of memory area that can be used for
4482 initial data and stack; please note that this must be
4483 writable memory that is working WITHOUT special
4484 initialization, i. e. you CANNOT use normal RAM which
4485 will become available only after programming the
4486 memory controller and running certain initialization
4489 U-Boot uses the following memory types:
4490 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4491 - MPC824X: data cache
4492 - PPC4xx: data cache
4494 - CONFIG_SYS_GBL_DATA_OFFSET:
4496 Offset of the initial data structure in the memory
4497 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4498 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4499 data is located at the end of the available space
4500 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4501 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4502 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4503 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4506 On the MPC824X (or other systems that use the data
4507 cache for initial memory) the address chosen for
4508 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4509 point to an otherwise UNUSED address space between
4510 the top of RAM and the start of the PCI space.
4512 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4514 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4516 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4518 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4520 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4522 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4524 - CONFIG_SYS_OR_TIMING_SDRAM:
4527 - CONFIG_SYS_MAMR_PTA:
4528 periodic timer for refresh
4530 - CONFIG_SYS_DER: Debug Event Register (37-47)
4532 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4533 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4534 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4535 CONFIG_SYS_BR1_PRELIM:
4536 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4538 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4539 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4540 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4541 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4543 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4544 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4545 Machine Mode Register and Memory Periodic Timer
4546 Prescaler definitions (SDRAM timing)
4548 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4549 enable I2C microcode relocation patch (MPC8xx);
4550 define relocation offset in DPRAM [DSP2]
4552 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4553 enable SMC microcode relocation patch (MPC8xx);
4554 define relocation offset in DPRAM [SMC1]
4556 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4557 enable SPI microcode relocation patch (MPC8xx);
4558 define relocation offset in DPRAM [SCC4]
4560 - CONFIG_SYS_USE_OSCCLK:
4561 Use OSCM clock mode on MBX8xx board. Be careful,
4562 wrong setting might damage your board. Read
4563 doc/README.MBX before setting this variable!
4565 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4566 Offset of the bootmode word in DPRAM used by post
4567 (Power On Self Tests). This definition overrides
4568 #define'd default value in commproc.h resp.
4571 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4572 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4573 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4574 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4575 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4576 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4577 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4578 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4579 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4581 - CONFIG_PCI_DISABLE_PCIE:
4582 Disable PCI-Express on systems where it is supported but not
4585 - CONFIG_PCI_ENUM_ONLY
4586 Only scan through and get the devices on the busses.
4587 Don't do any setup work, presumably because someone or
4588 something has already done it, and we don't need to do it
4589 a second time. Useful for platforms that are pre-booted
4590 by coreboot or similar.
4592 - CONFIG_PCI_INDIRECT_BRIDGE:
4593 Enable support for indirect PCI bridges.
4596 Chip has SRIO or not
4599 Board has SRIO 1 port available
4602 Board has SRIO 2 port available
4604 - CONFIG_SRIO_PCIE_BOOT_MASTER
4605 Board can support master function for Boot from SRIO and PCIE
4607 - CONFIG_SYS_SRIOn_MEM_VIRT:
4608 Virtual Address of SRIO port 'n' memory region
4610 - CONFIG_SYS_SRIOn_MEM_PHYS:
4611 Physical Address of SRIO port 'n' memory region
4613 - CONFIG_SYS_SRIOn_MEM_SIZE:
4614 Size of SRIO port 'n' memory region
4616 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4617 Defined to tell the NAND controller that the NAND chip is using
4619 Not all NAND drivers use this symbol.
4620 Example of drivers that use it:
4621 - drivers/mtd/nand/ndfc.c
4622 - drivers/mtd/nand/mxc_nand.c
4624 - CONFIG_SYS_NDFC_EBC0_CFG
4625 Sets the EBC0_CFG register for the NDFC. If not defined
4626 a default value will be used.
4629 Get DDR timing information from an I2C EEPROM. Common
4630 with pluggable memory modules such as SODIMMs
4633 I2C address of the SPD EEPROM
4635 - CONFIG_SYS_SPD_BUS_NUM
4636 If SPD EEPROM is on an I2C bus other than the first
4637 one, specify here. Note that the value must resolve
4638 to something your driver can deal with.
4640 - CONFIG_SYS_DDR_RAW_TIMING
4641 Get DDR timing information from other than SPD. Common with
4642 soldered DDR chips onboard without SPD. DDR raw timing
4643 parameters are extracted from datasheet and hard-coded into
4644 header files or board specific files.
4646 - CONFIG_FSL_DDR_INTERACTIVE
4647 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4649 - CONFIG_SYS_83XX_DDR_USES_CS0
4650 Only for 83xx systems. If specified, then DDR should
4651 be configured using CS0 and CS1 instead of CS2 and CS3.
4653 - CONFIG_ETHER_ON_FEC[12]
4654 Define to enable FEC[12] on a 8xx series processor.
4656 - CONFIG_FEC[12]_PHY
4657 Define to the hardcoded PHY address which corresponds
4658 to the given FEC; i. e.
4659 #define CONFIG_FEC1_PHY 4
4660 means that the PHY with address 4 is connected to FEC1
4662 When set to -1, means to probe for first available.
4664 - CONFIG_FEC[12]_PHY_NORXERR
4665 The PHY does not have a RXERR line (RMII only).
4666 (so program the FEC to ignore it).
4669 Enable RMII mode for all FECs.
4670 Note that this is a global option, we can't
4671 have one FEC in standard MII mode and another in RMII mode.
4673 - CONFIG_CRC32_VERIFY
4674 Add a verify option to the crc32 command.
4677 => crc32 -v <address> <count> <crc32>
4679 Where address/count indicate a memory area
4680 and crc32 is the correct crc32 which the
4684 Add the "loopw" memory command. This only takes effect if
4685 the memory commands are activated globally (CONFIG_CMD_MEM).
4688 Add the "mdc" and "mwc" memory commands. These are cyclic
4693 This command will print 4 bytes (10,11,12,13) each 500 ms.
4695 => mwc.l 100 12345678 10
4696 This command will write 12345678 to address 100 all 10 ms.
4698 This only takes effect if the memory commands are activated
4699 globally (CONFIG_CMD_MEM).
4701 - CONFIG_SKIP_LOWLEVEL_INIT
4702 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4703 low level initializations (like setting up the memory
4704 controller) are omitted and/or U-Boot does not
4705 relocate itself into RAM.
4707 Normally this variable MUST NOT be defined. The only
4708 exception is when U-Boot is loaded (to RAM) by some
4709 other boot loader or by a debugger which performs
4710 these initializations itself.
4713 Modifies the behaviour of start.S when compiling a loader
4714 that is executed before the actual U-Boot. E.g. when
4715 compiling a NAND SPL.
4718 Modifies the behaviour of start.S when compiling a loader
4719 that is executed after the SPL and before the actual U-Boot.
4720 It is loaded by the SPL.
4722 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4723 Only for 85xx systems. If this variable is specified, the section
4724 .resetvec is not kept and the section .bootpg is placed in the
4725 previous 4k of the .text section.
4727 - CONFIG_ARCH_MAP_SYSMEM
4728 Generally U-Boot (and in particular the md command) uses
4729 effective address. It is therefore not necessary to regard
4730 U-Boot address as virtual addresses that need to be translated
4731 to physical addresses. However, sandbox requires this, since
4732 it maintains its own little RAM buffer which contains all
4733 addressable memory. This option causes some memory accesses
4734 to be mapped through map_sysmem() / unmap_sysmem().
4736 - CONFIG_USE_ARCH_MEMCPY
4737 CONFIG_USE_ARCH_MEMSET
4738 If these options are used a optimized version of memcpy/memset will
4739 be used if available. These functions may be faster under some
4740 conditions but may increase the binary size.
4742 - CONFIG_X86_RESET_VECTOR
4743 If defined, the x86 reset vector code is included. This is not
4744 needed when U-Boot is running from Coreboot.
4747 Defines the MPU clock speed (in MHz).
4749 NOTE : currently only supported on AM335x platforms.
4751 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4752 Enables the RTC32K OSC on AM33xx based plattforms
4754 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4755 Option to disable subpage write in NAND driver
4756 driver that uses this:
4757 drivers/mtd/nand/davinci_nand.c
4759 Freescale QE/FMAN Firmware Support:
4760 -----------------------------------
4762 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4763 loading of "firmware", which is encoded in the QE firmware binary format.
4764 This firmware often needs to be loaded during U-Boot booting, so macros
4765 are used to identify the storage device (NOR flash, SPI, etc) and the address
4768 - CONFIG_SYS_FMAN_FW_ADDR
4769 The address in the storage device where the FMAN microcode is located. The
4770 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4773 - CONFIG_SYS_QE_FW_ADDR
4774 The address in the storage device where the QE microcode is located. The
4775 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4778 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4779 The maximum possible size of the firmware. The firmware binary format
4780 has a field that specifies the actual size of the firmware, but it
4781 might not be possible to read any part of the firmware unless some
4782 local storage is allocated to hold the entire firmware first.
4784 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4785 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4786 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4787 virtual address in NOR flash.
4789 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4790 Specifies that QE/FMAN firmware is located in NAND flash.
4791 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4793 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4794 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4795 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4797 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4798 Specifies that QE/FMAN firmware is located on the primary SPI
4799 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4801 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4802 Specifies that QE/FMAN firmware is located in the remote (master)
4803 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4804 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4805 window->master inbound window->master LAW->the ucode address in
4806 master's memory space.
4808 Freescale Layerscape Management Complex Firmware Support:
4809 ---------------------------------------------------------
4810 The Freescale Layerscape Management Complex (MC) supports the loading of
4812 This firmware often needs to be loaded during U-Boot booting, so macros
4813 are used to identify the storage device (NOR flash, SPI, etc) and the address
4816 - CONFIG_FSL_MC_ENET
4817 Enable the MC driver for Layerscape SoCs.
4819 - CONFIG_SYS_LS_MC_FW_ADDR
4820 The address in the storage device where the firmware is located. The
4821 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4824 - CONFIG_SYS_LS_MC_FW_LENGTH
4825 The maximum possible size of the firmware. The firmware binary format
4826 has a field that specifies the actual size of the firmware, but it
4827 might not be possible to read any part of the firmware unless some
4828 local storage is allocated to hold the entire firmware first.
4830 - CONFIG_SYS_LS_MC_FW_IN_NOR
4831 Specifies that MC firmware is located in NOR flash, mapped as
4832 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4833 virtual address in NOR flash.
4835 Building the Software:
4836 ======================
4838 Building U-Boot has been tested in several native build environments
4839 and in many different cross environments. Of course we cannot support
4840 all possibly existing versions of cross development tools in all
4841 (potentially obsolete) versions. In case of tool chain problems we
4842 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4843 which is extensively used to build and test U-Boot.
4845 If you are not using a native environment, it is assumed that you
4846 have GNU cross compiling tools available in your path. In this case,
4847 you must set the environment variable CROSS_COMPILE in your shell.
4848 Note that no changes to the Makefile or any other source files are
4849 necessary. For example using the ELDK on a 4xx CPU, please enter:
4851 $ CROSS_COMPILE=ppc_4xx-
4852 $ export CROSS_COMPILE
4854 Note: If you wish to generate Windows versions of the utilities in
4855 the tools directory you can use the MinGW toolchain
4856 (http://www.mingw.org). Set your HOST tools to the MinGW
4857 toolchain and execute 'make tools'. For example:
4859 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4861 Binaries such as tools/mkimage.exe will be created which can
4862 be executed on computers running Windows.
4864 U-Boot is intended to be simple to build. After installing the
4865 sources you must configure U-Boot for one specific board type. This
4870 where "NAME_defconfig" is the name of one of the existing configu-
4871 rations; see boards.cfg for supported names.
4873 Note: for some board special configuration names may exist; check if
4874 additional information is available from the board vendor; for
4875 instance, the TQM823L systems are available without (standard)
4876 or with LCD support. You can select such additional "features"
4877 when choosing the configuration, i. e.
4879 make TQM823L_defconfig
4880 - will configure for a plain TQM823L, i. e. no LCD support
4882 make TQM823L_LCD_defconfig
4883 - will configure for a TQM823L with U-Boot console on LCD
4888 Finally, type "make all", and you should get some working U-Boot
4889 images ready for download to / installation on your system:
4891 - "u-boot.bin" is a raw binary image
4892 - "u-boot" is an image in ELF binary format
4893 - "u-boot.srec" is in Motorola S-Record format
4895 By default the build is performed locally and the objects are saved
4896 in the source directory. One of the two methods can be used to change
4897 this behavior and build U-Boot to some external directory:
4899 1. Add O= to the make command line invocations:
4901 make O=/tmp/build distclean
4902 make O=/tmp/build NAME_defconfig
4903 make O=/tmp/build all
4905 2. Set environment variable BUILD_DIR to point to the desired location:
4907 export BUILD_DIR=/tmp/build
4912 Note that the command line "O=" setting overrides the BUILD_DIR environment
4916 Please be aware that the Makefiles assume you are using GNU make, so
4917 for instance on NetBSD you might need to use "gmake" instead of
4921 If the system board that you have is not listed, then you will need
4922 to port U-Boot to your hardware platform. To do this, follow these
4925 1. Add a new configuration option for your board to the toplevel
4926 "boards.cfg" file, using the existing entries as examples.
4927 Follow the instructions there to keep the boards in order.
4928 2. Create a new directory to hold your board specific code. Add any
4929 files you need. In your board directory, you will need at least
4930 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4931 3. Create a new configuration file "include/configs/<board>.h" for
4933 3. If you're porting U-Boot to a new CPU, then also create a new
4934 directory to hold your CPU specific code. Add any files you need.
4935 4. Run "make <board>_defconfig" with your new name.
4936 5. Type "make", and you should get a working "u-boot.srec" file
4937 to be installed on your target system.
4938 6. Debug and solve any problems that might arise.
4939 [Of course, this last step is much harder than it sounds.]
4942 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4943 ==============================================================
4945 If you have modified U-Boot sources (for instance added a new board
4946 or support for new devices, a new CPU, etc.) you are expected to
4947 provide feedback to the other developers. The feedback normally takes
4948 the form of a "patch", i. e. a context diff against a certain (latest
4949 official or latest in the git repository) version of U-Boot sources.
4951 But before you submit such a patch, please verify that your modifi-
4952 cation did not break existing code. At least make sure that *ALL* of
4953 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4954 just run the "MAKEALL" script, which will configure and build U-Boot
4955 for ALL supported system. Be warned, this will take a while. You can
4956 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4957 environment variable to the script, i. e. to use the ELDK cross tools
4960 CROSS_COMPILE=ppc_8xx- MAKEALL
4962 or to build on a native PowerPC system you can type
4964 CROSS_COMPILE=' ' MAKEALL
4966 When using the MAKEALL script, the default behaviour is to build
4967 U-Boot in the source directory. This location can be changed by
4968 setting the BUILD_DIR environment variable. Also, for each target
4969 built, the MAKEALL script saves two log files (<target>.ERR and
4970 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4971 location can be changed by setting the MAKEALL_LOGDIR environment
4972 variable. For example:
4974 export BUILD_DIR=/tmp/build
4975 export MAKEALL_LOGDIR=/tmp/log
4976 CROSS_COMPILE=ppc_8xx- MAKEALL
4978 With the above settings build objects are saved in the /tmp/build,
4979 log files are saved in the /tmp/log and the source tree remains clean
4980 during the whole build process.
4983 See also "U-Boot Porting Guide" below.
4986 Monitor Commands - Overview:
4987 ============================
4989 go - start application at address 'addr'
4990 run - run commands in an environment variable
4991 bootm - boot application image from memory
4992 bootp - boot image via network using BootP/TFTP protocol
4993 bootz - boot zImage from memory
4994 tftpboot- boot image via network using TFTP protocol
4995 and env variables "ipaddr" and "serverip"
4996 (and eventually "gatewayip")
4997 tftpput - upload a file via network using TFTP protocol
4998 rarpboot- boot image via network using RARP/TFTP protocol
4999 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
5000 loads - load S-Record file over serial line
5001 loadb - load binary file over serial line (kermit mode)
5003 mm - memory modify (auto-incrementing)
5004 nm - memory modify (constant address)
5005 mw - memory write (fill)
5007 cmp - memory compare
5008 crc32 - checksum calculation
5009 i2c - I2C sub-system
5010 sspi - SPI utility commands
5011 base - print or set address offset
5012 printenv- print environment variables
5013 setenv - set environment variables
5014 saveenv - save environment variables to persistent storage
5015 protect - enable or disable FLASH write protection
5016 erase - erase FLASH memory
5017 flinfo - print FLASH memory information
5018 nand - NAND memory operations (see doc/README.nand)
5019 bdinfo - print Board Info structure
5020 iminfo - print header information for application image
5021 coninfo - print console devices and informations
5022 ide - IDE sub-system
5023 loop - infinite loop on address range
5024 loopw - infinite write loop on address range
5025 mtest - simple RAM test
5026 icache - enable or disable instruction cache
5027 dcache - enable or disable data cache
5028 reset - Perform RESET of the CPU
5029 echo - echo args to console
5030 version - print monitor version
5031 help - print online help
5032 ? - alias for 'help'
5035 Monitor Commands - Detailed Description:
5036 ========================================
5040 For now: just type "help <command>".
5043 Environment Variables:
5044 ======================
5046 U-Boot supports user configuration using Environment Variables which
5047 can be made persistent by saving to Flash memory.
5049 Environment Variables are set using "setenv", printed using
5050 "printenv", and saved to Flash using "saveenv". Using "setenv"
5051 without a value can be used to delete a variable from the
5052 environment. As long as you don't save the environment you are
5053 working with an in-memory copy. In case the Flash area containing the
5054 environment is erased by accident, a default environment is provided.
5056 Some configuration options can be set using Environment Variables.
5058 List of environment variables (most likely not complete):
5060 baudrate - see CONFIG_BAUDRATE
5062 bootdelay - see CONFIG_BOOTDELAY
5064 bootcmd - see CONFIG_BOOTCOMMAND
5066 bootargs - Boot arguments when booting an RTOS image
5068 bootfile - Name of the image to load with TFTP
5070 bootm_low - Memory range available for image processing in the bootm
5071 command can be restricted. This variable is given as
5072 a hexadecimal number and defines lowest address allowed
5073 for use by the bootm command. See also "bootm_size"
5074 environment variable. Address defined by "bootm_low" is
5075 also the base of the initial memory mapping for the Linux
5076 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5079 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5080 This variable is given as a hexadecimal number and it
5081 defines the size of the memory region starting at base
5082 address bootm_low that is accessible by the Linux kernel
5083 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5084 as the default value if it is defined, and bootm_size is
5087 bootm_size - Memory range available for image processing in the bootm
5088 command can be restricted. This variable is given as
5089 a hexadecimal number and defines the size of the region
5090 allowed for use by the bootm command. See also "bootm_low"
5091 environment variable.
5093 updatefile - Location of the software update file on a TFTP server, used
5094 by the automatic software update feature. Please refer to
5095 documentation in doc/README.update for more details.
5097 autoload - if set to "no" (any string beginning with 'n'),
5098 "bootp" will just load perform a lookup of the
5099 configuration from the BOOTP server, but not try to
5100 load any image using TFTP
5102 autostart - if set to "yes", an image loaded using the "bootp",
5103 "rarpboot", "tftpboot" or "diskboot" commands will
5104 be automatically started (by internally calling
5107 If set to "no", a standalone image passed to the
5108 "bootm" command will be copied to the load address
5109 (and eventually uncompressed), but NOT be started.
5110 This can be used to load and uncompress arbitrary
5113 fdt_high - if set this restricts the maximum address that the
5114 flattened device tree will be copied into upon boot.
5115 For example, if you have a system with 1 GB memory
5116 at physical address 0x10000000, while Linux kernel
5117 only recognizes the first 704 MB as low memory, you
5118 may need to set fdt_high as 0x3C000000 to have the
5119 device tree blob be copied to the maximum address
5120 of the 704 MB low memory, so that Linux kernel can
5121 access it during the boot procedure.
5123 If this is set to the special value 0xFFFFFFFF then
5124 the fdt will not be copied at all on boot. For this
5125 to work it must reside in writable memory, have
5126 sufficient padding on the end of it for u-boot to
5127 add the information it needs into it, and the memory
5128 must be accessible by the kernel.
5130 fdtcontroladdr- if set this is the address of the control flattened
5131 device tree used by U-Boot when CONFIG_OF_CONTROL is
5134 i2cfast - (PPC405GP|PPC405EP only)
5135 if set to 'y' configures Linux I2C driver for fast
5136 mode (400kHZ). This environment variable is used in
5137 initialization code. So, for changes to be effective
5138 it must be saved and board must be reset.
5140 initrd_high - restrict positioning of initrd images:
5141 If this variable is not set, initrd images will be
5142 copied to the highest possible address in RAM; this
5143 is usually what you want since it allows for
5144 maximum initrd size. If for some reason you want to
5145 make sure that the initrd image is loaded below the
5146 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5147 variable to a value of "no" or "off" or "0".
5148 Alternatively, you can set it to a maximum upper
5149 address to use (U-Boot will still check that it
5150 does not overwrite the U-Boot stack and data).
5152 For instance, when you have a system with 16 MB
5153 RAM, and want to reserve 4 MB from use by Linux,
5154 you can do this by adding "mem=12M" to the value of
5155 the "bootargs" variable. However, now you must make
5156 sure that the initrd image is placed in the first
5157 12 MB as well - this can be done with
5159 setenv initrd_high 00c00000
5161 If you set initrd_high to 0xFFFFFFFF, this is an
5162 indication to U-Boot that all addresses are legal
5163 for the Linux kernel, including addresses in flash
5164 memory. In this case U-Boot will NOT COPY the
5165 ramdisk at all. This may be useful to reduce the
5166 boot time on your system, but requires that this
5167 feature is supported by your Linux kernel.
5169 ipaddr - IP address; needed for tftpboot command
5171 loadaddr - Default load address for commands like "bootp",
5172 "rarpboot", "tftpboot", "loadb" or "diskboot"
5174 loads_echo - see CONFIG_LOADS_ECHO
5176 serverip - TFTP server IP address; needed for tftpboot command
5178 bootretry - see CONFIG_BOOT_RETRY_TIME
5180 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5182 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5184 ethprime - controls which interface is used first.
5186 ethact - controls which interface is currently active.
5187 For example you can do the following
5189 => setenv ethact FEC
5190 => ping 192.168.0.1 # traffic sent on FEC
5191 => setenv ethact SCC
5192 => ping 10.0.0.1 # traffic sent on SCC
5194 ethrotate - When set to "no" U-Boot does not go through all
5195 available network interfaces.
5196 It just stays at the currently selected interface.
5198 netretry - When set to "no" each network operation will
5199 either succeed or fail without retrying.
5200 When set to "once" the network operation will
5201 fail when all the available network interfaces
5202 are tried once without success.
5203 Useful on scripts which control the retry operation
5206 npe_ucode - set load address for the NPE microcode
5208 silent_linux - If set then linux will be told to boot silently, by
5209 changing the console to be empty. If "yes" it will be
5210 made silent. If "no" it will not be made silent. If
5211 unset, then it will be made silent if the U-Boot console
5214 tftpsrcport - If this is set, the value is used for TFTP's
5217 tftpdstport - If this is set, the value is used for TFTP's UDP
5218 destination port instead of the Well Know Port 69.
5220 tftpblocksize - Block size to use for TFTP transfers; if not set,
5221 we use the TFTP server's default block size
5223 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5224 seconds, minimum value is 1000 = 1 second). Defines
5225 when a packet is considered to be lost so it has to
5226 be retransmitted. The default is 5000 = 5 seconds.
5227 Lowering this value may make downloads succeed
5228 faster in networks with high packet loss rates or
5229 with unreliable TFTP servers.
5231 vlan - When set to a value < 4095 the traffic over
5232 Ethernet is encapsulated/received over 802.1q
5235 The following image location variables contain the location of images
5236 used in booting. The "Image" column gives the role of the image and is
5237 not an environment variable name. The other columns are environment
5238 variable names. "File Name" gives the name of the file on a TFTP
5239 server, "RAM Address" gives the location in RAM the image will be
5240 loaded to, and "Flash Location" gives the image's address in NOR
5241 flash or offset in NAND flash.
5243 *Note* - these variables don't have to be defined for all boards, some
5244 boards currenlty use other variables for these purposes, and some
5245 boards use these variables for other purposes.
5247 Image File Name RAM Address Flash Location
5248 ----- --------- ----------- --------------
5249 u-boot u-boot u-boot_addr_r u-boot_addr
5250 Linux kernel bootfile kernel_addr_r kernel_addr
5251 device tree blob fdtfile fdt_addr_r fdt_addr
5252 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5254 The following environment variables may be used and automatically
5255 updated by the network boot commands ("bootp" and "rarpboot"),
5256 depending the information provided by your boot server:
5258 bootfile - see above
5259 dnsip - IP address of your Domain Name Server
5260 dnsip2 - IP address of your secondary Domain Name Server
5261 gatewayip - IP address of the Gateway (Router) to use
5262 hostname - Target hostname
5264 netmask - Subnet Mask
5265 rootpath - Pathname of the root filesystem on the NFS server
5266 serverip - see above
5269 There are two special Environment Variables:
5271 serial# - contains hardware identification information such
5272 as type string and/or serial number
5273 ethaddr - Ethernet address
5275 These variables can be set only once (usually during manufacturing of
5276 the board). U-Boot refuses to delete or overwrite these variables
5277 once they have been set once.
5280 Further special Environment Variables:
5282 ver - Contains the U-Boot version string as printed
5283 with the "version" command. This variable is
5284 readonly (see CONFIG_VERSION_VARIABLE).
5287 Please note that changes to some configuration parameters may take
5288 only effect after the next boot (yes, that's just like Windoze :-).
5291 Callback functions for environment variables:
5292 ---------------------------------------------
5294 For some environment variables, the behavior of u-boot needs to change
5295 when their values are changed. This functionailty allows functions to
5296 be associated with arbitrary variables. On creation, overwrite, or
5297 deletion, the callback will provide the opportunity for some side
5298 effect to happen or for the change to be rejected.
5300 The callbacks are named and associated with a function using the
5301 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5303 These callbacks are associated with variables in one of two ways. The
5304 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5305 in the board configuration to a string that defines a list of
5306 associations. The list must be in the following format:
5308 entry = variable_name[:callback_name]
5311 If the callback name is not specified, then the callback is deleted.
5312 Spaces are also allowed anywhere in the list.
5314 Callbacks can also be associated by defining the ".callbacks" variable
5315 with the same list format above. Any association in ".callbacks" will
5316 override any association in the static list. You can define
5317 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5318 ".callbacks" envirnoment variable in the default or embedded environment.
5321 Command Line Parsing:
5322 =====================
5324 There are two different command line parsers available with U-Boot:
5325 the old "simple" one, and the much more powerful "hush" shell:
5327 Old, simple command line parser:
5328 --------------------------------
5330 - supports environment variables (through setenv / saveenv commands)
5331 - several commands on one line, separated by ';'
5332 - variable substitution using "... ${name} ..." syntax
5333 - special characters ('$', ';') can be escaped by prefixing with '\',
5335 setenv bootcmd bootm \${address}
5336 - You can also escape text by enclosing in single apostrophes, for example:
5337 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5342 - similar to Bourne shell, with control structures like
5343 if...then...else...fi, for...do...done; while...do...done,
5344 until...do...done, ...
5345 - supports environment ("global") variables (through setenv / saveenv
5346 commands) and local shell variables (through standard shell syntax
5347 "name=value"); only environment variables can be used with "run"
5353 (1) If a command line (or an environment variable executed by a "run"
5354 command) contains several commands separated by semicolon, and
5355 one of these commands fails, then the remaining commands will be
5358 (2) If you execute several variables with one call to run (i. e.
5359 calling run with a list of variables as arguments), any failing
5360 command will cause "run" to terminate, i. e. the remaining
5361 variables are not executed.
5363 Note for Redundant Ethernet Interfaces:
5364 =======================================
5366 Some boards come with redundant Ethernet interfaces; U-Boot supports
5367 such configurations and is capable of automatic selection of a
5368 "working" interface when needed. MAC assignment works as follows:
5370 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5371 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5372 "eth1addr" (=>eth1), "eth2addr", ...
5374 If the network interface stores some valid MAC address (for instance
5375 in SROM), this is used as default address if there is NO correspon-
5376 ding setting in the environment; if the corresponding environment
5377 variable is set, this overrides the settings in the card; that means:
5379 o If the SROM has a valid MAC address, and there is no address in the
5380 environment, the SROM's address is used.
5382 o If there is no valid address in the SROM, and a definition in the
5383 environment exists, then the value from the environment variable is
5386 o If both the SROM and the environment contain a MAC address, and
5387 both addresses are the same, this MAC address is used.
5389 o If both the SROM and the environment contain a MAC address, and the
5390 addresses differ, the value from the environment is used and a
5393 o If neither SROM nor the environment contain a MAC address, an error
5396 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5397 will be programmed into hardware as part of the initialization process. This
5398 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5399 The naming convention is as follows:
5400 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5405 U-Boot is capable of booting (and performing other auxiliary operations on)
5406 images in two formats:
5408 New uImage format (FIT)
5409 -----------------------
5411 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5412 to Flattened Device Tree). It allows the use of images with multiple
5413 components (several kernels, ramdisks, etc.), with contents protected by
5414 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5420 Old image format is based on binary files which can be basically anything,
5421 preceded by a special header; see the definitions in include/image.h for
5422 details; basically, the header defines the following image properties:
5424 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5425 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5426 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5427 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5429 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5430 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5431 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5432 * Compression Type (uncompressed, gzip, bzip2)
5438 The header is marked by a special Magic Number, and both the header
5439 and the data portions of the image are secured against corruption by
5446 Although U-Boot should support any OS or standalone application
5447 easily, the main focus has always been on Linux during the design of
5450 U-Boot includes many features that so far have been part of some
5451 special "boot loader" code within the Linux kernel. Also, any
5452 "initrd" images to be used are no longer part of one big Linux image;
5453 instead, kernel and "initrd" are separate images. This implementation
5454 serves several purposes:
5456 - the same features can be used for other OS or standalone
5457 applications (for instance: using compressed images to reduce the
5458 Flash memory footprint)
5460 - it becomes much easier to port new Linux kernel versions because
5461 lots of low-level, hardware dependent stuff are done by U-Boot
5463 - the same Linux kernel image can now be used with different "initrd"
5464 images; of course this also means that different kernel images can
5465 be run with the same "initrd". This makes testing easier (you don't
5466 have to build a new "zImage.initrd" Linux image when you just
5467 change a file in your "initrd"). Also, a field-upgrade of the
5468 software is easier now.
5474 Porting Linux to U-Boot based systems:
5475 ---------------------------------------
5477 U-Boot cannot save you from doing all the necessary modifications to
5478 configure the Linux device drivers for use with your target hardware
5479 (no, we don't intend to provide a full virtual machine interface to
5482 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5484 Just make sure your machine specific header file (for instance
5485 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5486 Information structure as we define in include/asm-<arch>/u-boot.h,
5487 and make sure that your definition of IMAP_ADDR uses the same value
5488 as your U-Boot configuration in CONFIG_SYS_IMMR.
5490 Note that U-Boot now has a driver model, a unified model for drivers.
5491 If you are adding a new driver, plumb it into driver model. If there
5492 is no uclass available, you are encouraged to create one. See
5496 Configuring the Linux kernel:
5497 -----------------------------
5499 No specific requirements for U-Boot. Make sure you have some root
5500 device (initial ramdisk, NFS) for your target system.
5503 Building a Linux Image:
5504 -----------------------
5506 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5507 not used. If you use recent kernel source, a new build target
5508 "uImage" will exist which automatically builds an image usable by
5509 U-Boot. Most older kernels also have support for a "pImage" target,
5510 which was introduced for our predecessor project PPCBoot and uses a
5511 100% compatible format.
5515 make TQM850L_defconfig
5520 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5521 encapsulate a compressed Linux kernel image with header information,
5522 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5524 * build a standard "vmlinux" kernel image (in ELF binary format):
5526 * convert the kernel into a raw binary image:
5528 ${CROSS_COMPILE}-objcopy -O binary \
5529 -R .note -R .comment \
5530 -S vmlinux linux.bin
5532 * compress the binary image:
5536 * package compressed binary image for U-Boot:
5538 mkimage -A ppc -O linux -T kernel -C gzip \
5539 -a 0 -e 0 -n "Linux Kernel Image" \
5540 -d linux.bin.gz uImage
5543 The "mkimage" tool can also be used to create ramdisk images for use
5544 with U-Boot, either separated from the Linux kernel image, or
5545 combined into one file. "mkimage" encapsulates the images with a 64
5546 byte header containing information about target architecture,
5547 operating system, image type, compression method, entry points, time
5548 stamp, CRC32 checksums, etc.
5550 "mkimage" can be called in two ways: to verify existing images and
5551 print the header information, or to build new images.
5553 In the first form (with "-l" option) mkimage lists the information
5554 contained in the header of an existing U-Boot image; this includes
5555 checksum verification:
5557 tools/mkimage -l image
5558 -l ==> list image header information
5560 The second form (with "-d" option) is used to build a U-Boot image
5561 from a "data file" which is used as image payload:
5563 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5564 -n name -d data_file image
5565 -A ==> set architecture to 'arch'
5566 -O ==> set operating system to 'os'
5567 -T ==> set image type to 'type'
5568 -C ==> set compression type 'comp'
5569 -a ==> set load address to 'addr' (hex)
5570 -e ==> set entry point to 'ep' (hex)
5571 -n ==> set image name to 'name'
5572 -d ==> use image data from 'datafile'
5574 Right now, all Linux kernels for PowerPC systems use the same load
5575 address (0x00000000), but the entry point address depends on the
5578 - 2.2.x kernels have the entry point at 0x0000000C,
5579 - 2.3.x and later kernels have the entry point at 0x00000000.
5581 So a typical call to build a U-Boot image would read:
5583 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5584 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5585 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5586 > examples/uImage.TQM850L
5587 Image Name: 2.4.4 kernel for TQM850L
5588 Created: Wed Jul 19 02:34:59 2000
5589 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5590 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5591 Load Address: 0x00000000
5592 Entry Point: 0x00000000
5594 To verify the contents of the image (or check for corruption):
5596 -> tools/mkimage -l examples/uImage.TQM850L
5597 Image Name: 2.4.4 kernel for TQM850L
5598 Created: Wed Jul 19 02:34:59 2000
5599 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5600 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5601 Load Address: 0x00000000
5602 Entry Point: 0x00000000
5604 NOTE: for embedded systems where boot time is critical you can trade
5605 speed for memory and install an UNCOMPRESSED image instead: this
5606 needs more space in Flash, but boots much faster since it does not
5607 need to be uncompressed:
5609 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5610 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5611 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5612 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5613 > examples/uImage.TQM850L-uncompressed
5614 Image Name: 2.4.4 kernel for TQM850L
5615 Created: Wed Jul 19 02:34:59 2000
5616 Image Type: PowerPC Linux Kernel Image (uncompressed)
5617 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5618 Load Address: 0x00000000
5619 Entry Point: 0x00000000
5622 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5623 when your kernel is intended to use an initial ramdisk:
5625 -> tools/mkimage -n 'Simple Ramdisk Image' \
5626 > -A ppc -O linux -T ramdisk -C gzip \
5627 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5628 Image Name: Simple Ramdisk Image
5629 Created: Wed Jan 12 14:01:50 2000
5630 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5631 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5632 Load Address: 0x00000000
5633 Entry Point: 0x00000000
5635 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5636 option performs the converse operation of the mkimage's second form (the "-d"
5637 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5640 tools/dumpimage -i image -p position data_file
5641 -i ==> extract from the 'image' a specific 'data_file', \
5642 indexed by 'position'
5645 Installing a Linux Image:
5646 -------------------------
5648 To downloading a U-Boot image over the serial (console) interface,
5649 you must convert the image to S-Record format:
5651 objcopy -I binary -O srec examples/image examples/image.srec
5653 The 'objcopy' does not understand the information in the U-Boot
5654 image header, so the resulting S-Record file will be relative to
5655 address 0x00000000. To load it to a given address, you need to
5656 specify the target address as 'offset' parameter with the 'loads'
5659 Example: install the image to address 0x40100000 (which on the
5660 TQM8xxL is in the first Flash bank):
5662 => erase 40100000 401FFFFF
5668 ## Ready for S-Record download ...
5669 ~>examples/image.srec
5670 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5672 15989 15990 15991 15992
5673 [file transfer complete]
5675 ## Start Addr = 0x00000000
5678 You can check the success of the download using the 'iminfo' command;
5679 this includes a checksum verification so you can be sure no data
5680 corruption happened:
5684 ## Checking Image at 40100000 ...
5685 Image Name: 2.2.13 for initrd on TQM850L
5686 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5687 Data Size: 335725 Bytes = 327 kB = 0 MB
5688 Load Address: 00000000
5689 Entry Point: 0000000c
5690 Verifying Checksum ... OK
5696 The "bootm" command is used to boot an application that is stored in
5697 memory (RAM or Flash). In case of a Linux kernel image, the contents
5698 of the "bootargs" environment variable is passed to the kernel as
5699 parameters. You can check and modify this variable using the
5700 "printenv" and "setenv" commands:
5703 => printenv bootargs
5704 bootargs=root=/dev/ram
5706 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5708 => printenv bootargs
5709 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5712 ## Booting Linux kernel at 40020000 ...
5713 Image Name: 2.2.13 for NFS on TQM850L
5714 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5715 Data Size: 381681 Bytes = 372 kB = 0 MB
5716 Load Address: 00000000
5717 Entry Point: 0000000c
5718 Verifying Checksum ... OK
5719 Uncompressing Kernel Image ... OK
5720 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
5721 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5722 time_init: decrementer frequency = 187500000/60
5723 Calibrating delay loop... 49.77 BogoMIPS
5724 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5727 If you want to boot a Linux kernel with initial RAM disk, you pass
5728 the memory addresses of both the kernel and the initrd image (PPBCOOT
5729 format!) to the "bootm" command:
5731 => imi 40100000 40200000
5733 ## Checking Image at 40100000 ...
5734 Image Name: 2.2.13 for initrd on TQM850L
5735 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5736 Data Size: 335725 Bytes = 327 kB = 0 MB
5737 Load Address: 00000000
5738 Entry Point: 0000000c
5739 Verifying Checksum ... OK
5741 ## Checking Image at 40200000 ...
5742 Image Name: Simple Ramdisk Image
5743 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5744 Data Size: 566530 Bytes = 553 kB = 0 MB
5745 Load Address: 00000000
5746 Entry Point: 00000000
5747 Verifying Checksum ... OK
5749 => bootm 40100000 40200000
5750 ## Booting Linux kernel at 40100000 ...
5751 Image Name: 2.2.13 for initrd on TQM850L
5752 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5753 Data Size: 335725 Bytes = 327 kB = 0 MB
5754 Load Address: 00000000
5755 Entry Point: 0000000c
5756 Verifying Checksum ... OK
5757 Uncompressing Kernel Image ... OK
5758 ## Loading RAMDisk Image at 40200000 ...
5759 Image Name: Simple Ramdisk Image
5760 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5761 Data Size: 566530 Bytes = 553 kB = 0 MB
5762 Load Address: 00000000
5763 Entry Point: 00000000
5764 Verifying Checksum ... OK
5765 Loading Ramdisk ... OK
5766 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
5767 Boot arguments: root=/dev/ram
5768 time_init: decrementer frequency = 187500000/60
5769 Calibrating delay loop... 49.77 BogoMIPS
5771 RAMDISK: Compressed image found at block 0
5772 VFS: Mounted root (ext2 filesystem).
5776 Boot Linux and pass a flat device tree:
5779 First, U-Boot must be compiled with the appropriate defines. See the section
5780 titled "Linux Kernel Interface" above for a more in depth explanation. The
5781 following is an example of how to start a kernel and pass an updated
5787 oft=oftrees/mpc8540ads.dtb
5788 => tftp $oftaddr $oft
5789 Speed: 1000, full duplex
5791 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5792 Filename 'oftrees/mpc8540ads.dtb'.
5793 Load address: 0x300000
5796 Bytes transferred = 4106 (100a hex)
5797 => tftp $loadaddr $bootfile
5798 Speed: 1000, full duplex
5800 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5802 Load address: 0x200000
5803 Loading:############
5805 Bytes transferred = 1029407 (fb51f hex)
5810 => bootm $loadaddr - $oftaddr
5811 ## Booting image at 00200000 ...
5812 Image Name: Linux-2.6.17-dirty
5813 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5814 Data Size: 1029343 Bytes = 1005.2 kB
5815 Load Address: 00000000
5816 Entry Point: 00000000
5817 Verifying Checksum ... OK
5818 Uncompressing Kernel Image ... OK
5819 Booting using flat device tree at 0x300000
5820 Using MPC85xx ADS machine description
5821 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5825 More About U-Boot Image Types:
5826 ------------------------------
5828 U-Boot supports the following image types:
5830 "Standalone Programs" are directly runnable in the environment
5831 provided by U-Boot; it is expected that (if they behave
5832 well) you can continue to work in U-Boot after return from
5833 the Standalone Program.
5834 "OS Kernel Images" are usually images of some Embedded OS which
5835 will take over control completely. Usually these programs
5836 will install their own set of exception handlers, device
5837 drivers, set up the MMU, etc. - this means, that you cannot
5838 expect to re-enter U-Boot except by resetting the CPU.
5839 "RAMDisk Images" are more or less just data blocks, and their
5840 parameters (address, size) are passed to an OS kernel that is
5842 "Multi-File Images" contain several images, typically an OS
5843 (Linux) kernel image and one or more data images like
5844 RAMDisks. This construct is useful for instance when you want
5845 to boot over the network using BOOTP etc., where the boot
5846 server provides just a single image file, but you want to get
5847 for instance an OS kernel and a RAMDisk image.
5849 "Multi-File Images" start with a list of image sizes, each
5850 image size (in bytes) specified by an "uint32_t" in network
5851 byte order. This list is terminated by an "(uint32_t)0".
5852 Immediately after the terminating 0 follow the images, one by
5853 one, all aligned on "uint32_t" boundaries (size rounded up to
5854 a multiple of 4 bytes).
5856 "Firmware Images" are binary images containing firmware (like
5857 U-Boot or FPGA images) which usually will be programmed to
5860 "Script files" are command sequences that will be executed by
5861 U-Boot's command interpreter; this feature is especially
5862 useful when you configure U-Boot to use a real shell (hush)
5863 as command interpreter.
5865 Booting the Linux zImage:
5866 -------------------------
5868 On some platforms, it's possible to boot Linux zImage. This is done
5869 using the "bootz" command. The syntax of "bootz" command is the same
5870 as the syntax of "bootm" command.
5872 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5873 kernel with raw initrd images. The syntax is slightly different, the
5874 address of the initrd must be augmented by it's size, in the following
5875 format: "<initrd addres>:<initrd size>".
5881 One of the features of U-Boot is that you can dynamically load and
5882 run "standalone" applications, which can use some resources of
5883 U-Boot like console I/O functions or interrupt services.
5885 Two simple examples are included with the sources:
5890 'examples/hello_world.c' contains a small "Hello World" Demo
5891 application; it is automatically compiled when you build U-Boot.
5892 It's configured to run at address 0x00040004, so you can play with it
5896 ## Ready for S-Record download ...
5897 ~>examples/hello_world.srec
5898 1 2 3 4 5 6 7 8 9 10 11 ...
5899 [file transfer complete]
5901 ## Start Addr = 0x00040004
5903 => go 40004 Hello World! This is a test.
5904 ## Starting application at 0x00040004 ...
5915 Hit any key to exit ...
5917 ## Application terminated, rc = 0x0
5919 Another example, which demonstrates how to register a CPM interrupt
5920 handler with the U-Boot code, can be found in 'examples/timer.c'.
5921 Here, a CPM timer is set up to generate an interrupt every second.
5922 The interrupt service routine is trivial, just printing a '.'
5923 character, but this is just a demo program. The application can be
5924 controlled by the following keys:
5926 ? - print current values og the CPM Timer registers
5927 b - enable interrupts and start timer
5928 e - stop timer and disable interrupts
5929 q - quit application
5932 ## Ready for S-Record download ...
5933 ~>examples/timer.srec
5934 1 2 3 4 5 6 7 8 9 10 11 ...
5935 [file transfer complete]
5937 ## Start Addr = 0x00040004
5940 ## Starting application at 0x00040004 ...
5943 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5946 [q, b, e, ?] Set interval 1000000 us
5949 [q, b, e, ?] ........
5950 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5953 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5956 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5959 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5961 [q, b, e, ?] ...Stopping timer
5963 [q, b, e, ?] ## Application terminated, rc = 0x0
5969 Over time, many people have reported problems when trying to use the
5970 "minicom" terminal emulation program for serial download. I (wd)
5971 consider minicom to be broken, and recommend not to use it. Under
5972 Unix, I recommend to use C-Kermit for general purpose use (and
5973 especially for kermit binary protocol download ("loadb" command), and
5974 use "cu" for S-Record download ("loads" command). See
5975 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5976 for help with kermit.
5979 Nevertheless, if you absolutely want to use it try adding this
5980 configuration to your "File transfer protocols" section:
5982 Name Program Name U/D FullScr IO-Red. Multi
5983 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5984 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5990 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5991 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5993 Building requires a cross environment; it is known to work on
5994 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5995 need gmake since the Makefiles are not compatible with BSD make).
5996 Note that the cross-powerpc package does not install include files;
5997 attempting to build U-Boot will fail because <machine/ansi.h> is
5998 missing. This file has to be installed and patched manually:
6000 # cd /usr/pkg/cross/powerpc-netbsd/include
6002 # ln -s powerpc machine
6003 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
6004 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
6006 Native builds *don't* work due to incompatibilities between native
6007 and U-Boot include files.
6009 Booting assumes that (the first part of) the image booted is a
6010 stage-2 loader which in turn loads and then invokes the kernel
6011 proper. Loader sources will eventually appear in the NetBSD source
6012 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
6013 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
6016 Implementation Internals:
6017 =========================
6019 The following is not intended to be a complete description of every
6020 implementation detail. However, it should help to understand the
6021 inner workings of U-Boot and make it easier to port it to custom
6025 Initial Stack, Global Data:
6026 ---------------------------
6028 The implementation of U-Boot is complicated by the fact that U-Boot
6029 starts running out of ROM (flash memory), usually without access to
6030 system RAM (because the memory controller is not initialized yet).
6031 This means that we don't have writable Data or BSS segments, and BSS
6032 is not initialized as zero. To be able to get a C environment working
6033 at all, we have to allocate at least a minimal stack. Implementation
6034 options for this are defined and restricted by the CPU used: Some CPU
6035 models provide on-chip memory (like the IMMR area on MPC8xx and
6036 MPC826x processors), on others (parts of) the data cache can be
6037 locked as (mis-) used as memory, etc.
6039 Chris Hallinan posted a good summary of these issues to the
6040 U-Boot mailing list:
6042 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6043 From: "Chris Hallinan" <clh@net1plus.com>
6044 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6047 Correct me if I'm wrong, folks, but the way I understand it
6048 is this: Using DCACHE as initial RAM for Stack, etc, does not
6049 require any physical RAM backing up the cache. The cleverness
6050 is that the cache is being used as a temporary supply of
6051 necessary storage before the SDRAM controller is setup. It's
6052 beyond the scope of this list to explain the details, but you
6053 can see how this works by studying the cache architecture and
6054 operation in the architecture and processor-specific manuals.
6056 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6057 is another option for the system designer to use as an
6058 initial stack/RAM area prior to SDRAM being available. Either
6059 option should work for you. Using CS 4 should be fine if your
6060 board designers haven't used it for something that would
6061 cause you grief during the initial boot! It is frequently not
6064 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6065 with your processor/board/system design. The default value
6066 you will find in any recent u-boot distribution in
6067 walnut.h should work for you. I'd set it to a value larger
6068 than your SDRAM module. If you have a 64MB SDRAM module, set
6069 it above 400_0000. Just make sure your board has no resources
6070 that are supposed to respond to that address! That code in
6071 start.S has been around a while and should work as is when
6072 you get the config right.
6077 It is essential to remember this, since it has some impact on the C
6078 code for the initialization procedures:
6080 * Initialized global data (data segment) is read-only. Do not attempt
6083 * Do not use any uninitialized global data (or implicitely initialized
6084 as zero data - BSS segment) at all - this is undefined, initiali-
6085 zation is performed later (when relocating to RAM).
6087 * Stack space is very limited. Avoid big data buffers or things like
6090 Having only the stack as writable memory limits means we cannot use
6091 normal global data to share information beween the code. But it
6092 turned out that the implementation of U-Boot can be greatly
6093 simplified by making a global data structure (gd_t) available to all
6094 functions. We could pass a pointer to this data as argument to _all_
6095 functions, but this would bloat the code. Instead we use a feature of
6096 the GCC compiler (Global Register Variables) to share the data: we
6097 place a pointer (gd) to the global data into a register which we
6098 reserve for this purpose.
6100 When choosing a register for such a purpose we are restricted by the
6101 relevant (E)ABI specifications for the current architecture, and by
6102 GCC's implementation.
6104 For PowerPC, the following registers have specific use:
6106 R2: reserved for system use
6107 R3-R4: parameter passing and return values
6108 R5-R10: parameter passing
6109 R13: small data area pointer
6113 (U-Boot also uses R12 as internal GOT pointer. r12
6114 is a volatile register so r12 needs to be reset when
6115 going back and forth between asm and C)
6117 ==> U-Boot will use R2 to hold a pointer to the global data
6119 Note: on PPC, we could use a static initializer (since the
6120 address of the global data structure is known at compile time),
6121 but it turned out that reserving a register results in somewhat
6122 smaller code - although the code savings are not that big (on
6123 average for all boards 752 bytes for the whole U-Boot image,
6124 624 text + 127 data).
6126 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6127 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6129 ==> U-Boot will use P3 to hold a pointer to the global data
6131 On ARM, the following registers are used:
6133 R0: function argument word/integer result
6134 R1-R3: function argument word
6135 R9: platform specific
6136 R10: stack limit (used only if stack checking is enabled)
6137 R11: argument (frame) pointer
6138 R12: temporary workspace
6141 R15: program counter
6143 ==> U-Boot will use R9 to hold a pointer to the global data
6145 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6147 On Nios II, the ABI is documented here:
6148 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6150 ==> U-Boot will use gp to hold a pointer to the global data
6152 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6153 to access small data sections, so gp is free.
6155 On NDS32, the following registers are used:
6157 R0-R1: argument/return
6159 R15: temporary register for assembler
6160 R16: trampoline register
6161 R28: frame pointer (FP)
6162 R29: global pointer (GP)
6163 R30: link register (LP)
6164 R31: stack pointer (SP)
6165 PC: program counter (PC)
6167 ==> U-Boot will use R10 to hold a pointer to the global data
6169 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6170 or current versions of GCC may "optimize" the code too much.
6175 U-Boot runs in system state and uses physical addresses, i.e. the
6176 MMU is not used either for address mapping nor for memory protection.
6178 The available memory is mapped to fixed addresses using the memory
6179 controller. In this process, a contiguous block is formed for each
6180 memory type (Flash, SDRAM, SRAM), even when it consists of several
6181 physical memory banks.
6183 U-Boot is installed in the first 128 kB of the first Flash bank (on
6184 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6185 booting and sizing and initializing DRAM, the code relocates itself
6186 to the upper end of DRAM. Immediately below the U-Boot code some
6187 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6188 configuration setting]. Below that, a structure with global Board
6189 Info data is placed, followed by the stack (growing downward).
6191 Additionally, some exception handler code is copied to the low 8 kB
6192 of DRAM (0x00000000 ... 0x00001FFF).
6194 So a typical memory configuration with 16 MB of DRAM could look like
6197 0x0000 0000 Exception Vector code
6200 0x0000 2000 Free for Application Use
6206 0x00FB FF20 Monitor Stack (Growing downward)
6207 0x00FB FFAC Board Info Data and permanent copy of global data
6208 0x00FC 0000 Malloc Arena
6211 0x00FE 0000 RAM Copy of Monitor Code
6212 ... eventually: LCD or video framebuffer
6213 ... eventually: pRAM (Protected RAM - unchanged by reset)
6214 0x00FF FFFF [End of RAM]
6217 System Initialization:
6218 ----------------------
6220 In the reset configuration, U-Boot starts at the reset entry point
6221 (on most PowerPC systems at address 0x00000100). Because of the reset
6222 configuration for CS0# this is a mirror of the onboard Flash memory.
6223 To be able to re-map memory U-Boot then jumps to its link address.
6224 To be able to implement the initialization code in C, a (small!)
6225 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6226 which provide such a feature like MPC8xx or MPC8260), or in a locked
6227 part of the data cache. After that, U-Boot initializes the CPU core,
6228 the caches and the SIU.
6230 Next, all (potentially) available memory banks are mapped using a
6231 preliminary mapping. For example, we put them on 512 MB boundaries
6232 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6233 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6234 programmed for SDRAM access. Using the temporary configuration, a
6235 simple memory test is run that determines the size of the SDRAM
6238 When there is more than one SDRAM bank, and the banks are of
6239 different size, the largest is mapped first. For equal size, the first
6240 bank (CS2#) is mapped first. The first mapping is always for address
6241 0x00000000, with any additional banks following immediately to create
6242 contiguous memory starting from 0.
6244 Then, the monitor installs itself at the upper end of the SDRAM area
6245 and allocates memory for use by malloc() and for the global Board
6246 Info data; also, the exception vector code is copied to the low RAM
6247 pages, and the final stack is set up.
6249 Only after this relocation will you have a "normal" C environment;
6250 until that you are restricted in several ways, mostly because you are
6251 running from ROM, and because the code will have to be relocated to a
6255 U-Boot Porting Guide:
6256 ----------------------
6258 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6262 int main(int argc, char *argv[])
6264 sighandler_t no_more_time;
6266 signal(SIGALRM, no_more_time);
6267 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6269 if (available_money > available_manpower) {
6270 Pay consultant to port U-Boot;
6274 Download latest U-Boot source;
6276 Subscribe to u-boot mailing list;
6279 email("Hi, I am new to U-Boot, how do I get started?");
6282 Read the README file in the top level directory;
6283 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6284 Read applicable doc/*.README;
6285 Read the source, Luke;
6286 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6289 if (available_money > toLocalCurrency ($2500))
6292 Add a lot of aggravation and time;
6294 if (a similar board exists) { /* hopefully... */
6295 cp -a board/<similar> board/<myboard>
6296 cp include/configs/<similar>.h include/configs/<myboard>.h
6298 Create your own board support subdirectory;
6299 Create your own board include/configs/<myboard>.h file;
6301 Edit new board/<myboard> files
6302 Edit new include/configs/<myboard>.h
6307 Add / modify source code;
6311 email("Hi, I am having problems...");
6313 Send patch file to the U-Boot email list;
6314 if (reasonable critiques)
6315 Incorporate improvements from email list code review;
6317 Defend code as written;
6323 void no_more_time (int sig)
6332 All contributions to U-Boot should conform to the Linux kernel
6333 coding style; see the file "Documentation/CodingStyle" and the script
6334 "scripts/Lindent" in your Linux kernel source directory.
6336 Source files originating from a different project (for example the
6337 MTD subsystem) are generally exempt from these guidelines and are not
6338 reformated to ease subsequent migration to newer versions of those
6341 Please note that U-Boot is implemented in C (and to some small parts in
6342 Assembler); no C++ is used, so please do not use C++ style comments (//)
6345 Please also stick to the following formatting rules:
6346 - remove any trailing white space
6347 - use TAB characters for indentation and vertical alignment, not spaces
6348 - make sure NOT to use DOS '\r\n' line feeds
6349 - do not add more than 2 consecutive empty lines to source files
6350 - do not add trailing empty lines to source files
6352 Submissions which do not conform to the standards may be returned
6353 with a request to reformat the changes.
6359 Since the number of patches for U-Boot is growing, we need to
6360 establish some rules. Submissions which do not conform to these rules
6361 may be rejected, even when they contain important and valuable stuff.
6363 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6365 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6366 see http://lists.denx.de/mailman/listinfo/u-boot
6368 When you send a patch, please include the following information with
6371 * For bug fixes: a description of the bug and how your patch fixes
6372 this bug. Please try to include a way of demonstrating that the
6373 patch actually fixes something.
6375 * For new features: a description of the feature and your
6378 * A CHANGELOG entry as plaintext (separate from the patch)
6380 * For major contributions, your entry to the CREDITS file
6382 * When you add support for a new board, don't forget to add a
6383 maintainer e-mail address to the boards.cfg file, too.
6385 * If your patch adds new configuration options, don't forget to
6386 document these in the README file.
6388 * The patch itself. If you are using git (which is *strongly*
6389 recommended) you can easily generate the patch using the
6390 "git format-patch". If you then use "git send-email" to send it to
6391 the U-Boot mailing list, you will avoid most of the common problems
6392 with some other mail clients.
6394 If you cannot use git, use "diff -purN OLD NEW". If your version of
6395 diff does not support these options, then get the latest version of
6398 The current directory when running this command shall be the parent
6399 directory of the U-Boot source tree (i. e. please make sure that
6400 your patch includes sufficient directory information for the
6403 We prefer patches as plain text. MIME attachments are discouraged,
6404 and compressed attachments must not be used.
6406 * If one logical set of modifications affects or creates several
6407 files, all these changes shall be submitted in a SINGLE patch file.
6409 * Changesets that contain different, unrelated modifications shall be
6410 submitted as SEPARATE patches, one patch per changeset.
6415 * Before sending the patch, run the MAKEALL script on your patched
6416 source tree and make sure that no errors or warnings are reported
6417 for any of the boards.
6419 * Keep your modifications to the necessary minimum: A patch
6420 containing several unrelated changes or arbitrary reformats will be
6421 returned with a request to re-formatting / split it.
6423 * If you modify existing code, make sure that your new code does not
6424 add to the memory footprint of the code ;-) Small is beautiful!
6425 When adding new features, these should compile conditionally only
6426 (using #ifdef), and the resulting code with the new feature
6427 disabled must not need more memory than the old code without your
6430 * Remember that there is a size limit of 100 kB per message on the
6431 u-boot mailing list. Bigger patches will be moderated. If they are
6432 reasonable and not too big, they will be acknowledged. But patches
6433 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob