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>_config".
257 Example: For a TQM823L module type:
262 For the Cogent platform, you need to specify the CPU type as well;
263 e.g. "make cogent_mpc8xx_config". 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 - DHCP Advanced Options:
2040 You can fine tune the DHCP functionality by defining
2041 CONFIG_BOOTP_* symbols:
2043 CONFIG_BOOTP_SUBNETMASK
2044 CONFIG_BOOTP_GATEWAY
2045 CONFIG_BOOTP_HOSTNAME
2046 CONFIG_BOOTP_NISDOMAIN
2047 CONFIG_BOOTP_BOOTPATH
2048 CONFIG_BOOTP_BOOTFILESIZE
2051 CONFIG_BOOTP_SEND_HOSTNAME
2052 CONFIG_BOOTP_NTPSERVER
2053 CONFIG_BOOTP_TIMEOFFSET
2054 CONFIG_BOOTP_VENDOREX
2055 CONFIG_BOOTP_MAY_FAIL
2057 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2058 environment variable, not the BOOTP server.
2060 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2061 after the configured retry count, the call will fail
2062 instead of starting over. This can be used to fail over
2063 to Link-local IP address configuration if the DHCP server
2066 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2067 serverip from a DHCP server, it is possible that more
2068 than one DNS serverip is offered to the client.
2069 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2070 serverip will be stored in the additional environment
2071 variable "dnsip2". The first DNS serverip is always
2072 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2075 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2076 to do a dynamic update of a DNS server. To do this, they
2077 need the hostname of the DHCP requester.
2078 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2079 of the "hostname" environment variable is passed as
2080 option 12 to the DHCP server.
2082 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2084 A 32bit value in microseconds for a delay between
2085 receiving a "DHCP Offer" and sending the "DHCP Request".
2086 This fixes a problem with certain DHCP servers that don't
2087 respond 100% of the time to a "DHCP request". E.g. On an
2088 AT91RM9200 processor running at 180MHz, this delay needed
2089 to be *at least* 15,000 usec before a Windows Server 2003
2090 DHCP server would reply 100% of the time. I recommend at
2091 least 50,000 usec to be safe. The alternative is to hope
2092 that one of the retries will be successful but note that
2093 the DHCP timeout and retry process takes a longer than
2096 - Link-local IP address negotiation:
2097 Negotiate with other link-local clients on the local network
2098 for an address that doesn't require explicit configuration.
2099 This is especially useful if a DHCP server cannot be guaranteed
2100 to exist in all environments that the device must operate.
2102 See doc/README.link-local for more information.
2105 CONFIG_CDP_DEVICE_ID
2107 The device id used in CDP trigger frames.
2109 CONFIG_CDP_DEVICE_ID_PREFIX
2111 A two character string which is prefixed to the MAC address
2116 A printf format string which contains the ascii name of
2117 the port. Normally is set to "eth%d" which sets
2118 eth0 for the first Ethernet, eth1 for the second etc.
2120 CONFIG_CDP_CAPABILITIES
2122 A 32bit integer which indicates the device capabilities;
2123 0x00000010 for a normal host which does not forwards.
2127 An ascii string containing the version of the software.
2131 An ascii string containing the name of the platform.
2135 A 32bit integer sent on the trigger.
2137 CONFIG_CDP_POWER_CONSUMPTION
2139 A 16bit integer containing the power consumption of the
2140 device in .1 of milliwatts.
2142 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2144 A byte containing the id of the VLAN.
2146 - Status LED: CONFIG_STATUS_LED
2148 Several configurations allow to display the current
2149 status using a LED. For instance, the LED will blink
2150 fast while running U-Boot code, stop blinking as
2151 soon as a reply to a BOOTP request was received, and
2152 start blinking slow once the Linux kernel is running
2153 (supported by a status LED driver in the Linux
2154 kernel). Defining CONFIG_STATUS_LED enables this
2160 The status LED can be connected to a GPIO pin.
2161 In such cases, the gpio_led driver can be used as a
2162 status LED backend implementation. Define CONFIG_GPIO_LED
2163 to include the gpio_led driver in the U-Boot binary.
2165 CONFIG_GPIO_LED_INVERTED_TABLE
2166 Some GPIO connected LEDs may have inverted polarity in which
2167 case the GPIO high value corresponds to LED off state and
2168 GPIO low value corresponds to LED on state.
2169 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2170 with a list of GPIO LEDs that have inverted polarity.
2172 - CAN Support: CONFIG_CAN_DRIVER
2174 Defining CONFIG_CAN_DRIVER enables CAN driver support
2175 on those systems that support this (optional)
2176 feature, like the TQM8xxL modules.
2178 - I2C Support: CONFIG_SYS_I2C
2180 This enable the NEW i2c subsystem, and will allow you to use
2181 i2c commands at the u-boot command line (as long as you set
2182 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2183 based realtime clock chips or other i2c devices. See
2184 common/cmd_i2c.c for a description of the command line
2187 ported i2c driver to the new framework:
2188 - drivers/i2c/soft_i2c.c:
2189 - activate first bus with CONFIG_SYS_I2C_SOFT define
2190 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2191 for defining speed and slave address
2192 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2193 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2194 for defining speed and slave address
2195 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2196 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2197 for defining speed and slave address
2198 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2199 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2200 for defining speed and slave address
2202 - drivers/i2c/fsl_i2c.c:
2203 - activate i2c driver with CONFIG_SYS_I2C_FSL
2204 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2205 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2206 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2208 - If your board supports a second fsl i2c bus, define
2209 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2210 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2211 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2214 - drivers/i2c/tegra_i2c.c:
2215 - activate this driver with CONFIG_SYS_I2C_TEGRA
2216 - This driver adds 4 i2c buses with a fix speed from
2217 100000 and the slave addr 0!
2219 - drivers/i2c/ppc4xx_i2c.c
2220 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2221 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2222 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2224 - drivers/i2c/i2c_mxc.c
2225 - activate this driver with CONFIG_SYS_I2C_MXC
2226 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2227 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2228 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2229 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2230 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2231 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2232 If thoses defines are not set, default value is 100000
2233 for speed, and 0 for slave.
2235 - drivers/i2c/rcar_i2c.c:
2236 - activate this driver with CONFIG_SYS_I2C_RCAR
2237 - This driver adds 4 i2c buses
2239 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2240 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2241 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2242 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2243 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2244 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2245 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2246 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2247 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2249 - drivers/i2c/sh_i2c.c:
2250 - activate this driver with CONFIG_SYS_I2C_SH
2251 - This driver adds from 2 to 5 i2c buses
2253 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2254 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2255 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2256 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2257 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2258 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2259 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2260 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2261 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2262 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2263 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2264 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2265 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2267 - drivers/i2c/omap24xx_i2c.c
2268 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2269 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2270 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2271 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2272 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2273 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2274 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2275 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2276 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2277 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2278 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2280 - drivers/i2c/zynq_i2c.c
2281 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2282 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2283 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2285 - drivers/i2c/s3c24x0_i2c.c:
2286 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2287 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2288 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2289 with a fix speed from 100000 and the slave addr 0!
2291 - drivers/i2c/ihs_i2c.c
2292 - activate this driver with CONFIG_SYS_I2C_IHS
2293 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2294 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2295 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2296 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2297 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2298 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2299 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2300 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2301 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2302 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2303 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2304 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2308 CONFIG_SYS_NUM_I2C_BUSES
2309 Hold the number of i2c busses you want to use. If you
2310 don't use/have i2c muxes on your i2c bus, this
2311 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2314 CONFIG_SYS_I2C_DIRECT_BUS
2315 define this, if you don't use i2c muxes on your hardware.
2316 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2319 CONFIG_SYS_I2C_MAX_HOPS
2320 define how many muxes are maximal consecutively connected
2321 on one i2c bus. If you not use i2c muxes, omit this
2324 CONFIG_SYS_I2C_BUSES
2325 hold a list of busses you want to use, only used if
2326 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2327 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2328 CONFIG_SYS_NUM_I2C_BUSES = 9:
2330 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2331 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2332 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2333 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2334 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2335 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2336 {1, {I2C_NULL_HOP}}, \
2337 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2338 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2342 bus 0 on adapter 0 without a mux
2343 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2344 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2345 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2346 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2347 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2348 bus 6 on adapter 1 without a mux
2349 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2350 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2352 If you do not have i2c muxes on your board, omit this define.
2354 - Legacy I2C Support: CONFIG_HARD_I2C
2356 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2357 provides the following compelling advantages:
2359 - more than one i2c adapter is usable
2360 - approved multibus support
2361 - better i2c mux support
2363 ** Please consider updating your I2C driver now. **
2365 These enable legacy I2C serial bus commands. Defining
2366 CONFIG_HARD_I2C will include the appropriate I2C driver
2367 for the selected CPU.
2369 This will allow you to use i2c commands at the u-boot
2370 command line (as long as you set CONFIG_CMD_I2C in
2371 CONFIG_COMMANDS) and communicate with i2c based realtime
2372 clock chips. See common/cmd_i2c.c for a description of the
2373 command line interface.
2375 CONFIG_HARD_I2C selects a hardware I2C controller.
2377 There are several other quantities that must also be
2378 defined when you define CONFIG_HARD_I2C.
2380 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2381 to be the frequency (in Hz) at which you wish your i2c bus
2382 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2383 the CPU's i2c node address).
2385 Now, the u-boot i2c code for the mpc8xx
2386 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2387 and so its address should therefore be cleared to 0 (See,
2388 eg, MPC823e User's Manual p.16-473). So, set
2389 CONFIG_SYS_I2C_SLAVE to 0.
2391 CONFIG_SYS_I2C_INIT_MPC5XXX
2393 When a board is reset during an i2c bus transfer
2394 chips might think that the current transfer is still
2395 in progress. Reset the slave devices by sending start
2396 commands until the slave device responds.
2398 That's all that's required for CONFIG_HARD_I2C.
2400 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2401 then the following macros need to be defined (examples are
2402 from include/configs/lwmon.h):
2406 (Optional). Any commands necessary to enable the I2C
2407 controller or configure ports.
2409 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2413 (Only for MPC8260 CPU). The I/O port to use (the code
2414 assumes both bits are on the same port). Valid values
2415 are 0..3 for ports A..D.
2419 The code necessary to make the I2C data line active
2420 (driven). If the data line is open collector, this
2423 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2427 The code necessary to make the I2C data line tri-stated
2428 (inactive). If the data line is open collector, this
2431 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2435 Code that returns true if the I2C data line is high,
2438 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2442 If <bit> is true, sets the I2C data line high. If it
2443 is false, it clears it (low).
2445 eg: #define I2C_SDA(bit) \
2446 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2447 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2451 If <bit> is true, sets the I2C clock line high. If it
2452 is false, it clears it (low).
2454 eg: #define I2C_SCL(bit) \
2455 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2456 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2460 This delay is invoked four times per clock cycle so this
2461 controls the rate of data transfer. The data rate thus
2462 is 1 / (I2C_DELAY * 4). Often defined to be something
2465 #define I2C_DELAY udelay(2)
2467 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2469 If your arch supports the generic GPIO framework (asm/gpio.h),
2470 then you may alternatively define the two GPIOs that are to be
2471 used as SCL / SDA. Any of the previous I2C_xxx macros will
2472 have GPIO-based defaults assigned to them as appropriate.
2474 You should define these to the GPIO value as given directly to
2475 the generic GPIO functions.
2477 CONFIG_SYS_I2C_INIT_BOARD
2479 When a board is reset during an i2c bus transfer
2480 chips might think that the current transfer is still
2481 in progress. On some boards it is possible to access
2482 the i2c SCLK line directly, either by using the
2483 processor pin as a GPIO or by having a second pin
2484 connected to the bus. If this option is defined a
2485 custom i2c_init_board() routine in boards/xxx/board.c
2486 is run early in the boot sequence.
2488 CONFIG_SYS_I2C_BOARD_LATE_INIT
2490 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2491 defined a custom i2c_board_late_init() routine in
2492 boards/xxx/board.c is run AFTER the operations in i2c_init()
2493 is completed. This callpoint can be used to unreset i2c bus
2494 using CPU i2c controller register accesses for CPUs whose i2c
2495 controller provide such a method. It is called at the end of
2496 i2c_init() to allow i2c_init operations to setup the i2c bus
2497 controller on the CPU (e.g. setting bus speed & slave address).
2499 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2501 This option enables configuration of bi_iic_fast[] flags
2502 in u-boot bd_info structure based on u-boot environment
2503 variable "i2cfast". (see also i2cfast)
2505 CONFIG_I2C_MULTI_BUS
2507 This option allows the use of multiple I2C buses, each of which
2508 must have a controller. At any point in time, only one bus is
2509 active. To switch to a different bus, use the 'i2c dev' command.
2510 Note that bus numbering is zero-based.
2512 CONFIG_SYS_I2C_NOPROBES
2514 This option specifies a list of I2C devices that will be skipped
2515 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2516 is set, specify a list of bus-device pairs. Otherwise, specify
2517 a 1D array of device addresses
2520 #undef CONFIG_I2C_MULTI_BUS
2521 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2523 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2525 #define CONFIG_I2C_MULTI_BUS
2526 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2528 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2530 CONFIG_SYS_SPD_BUS_NUM
2532 If defined, then this indicates the I2C bus number for DDR SPD.
2533 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2535 CONFIG_SYS_RTC_BUS_NUM
2537 If defined, then this indicates the I2C bus number for the RTC.
2538 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2540 CONFIG_SYS_DTT_BUS_NUM
2542 If defined, then this indicates the I2C bus number for the DTT.
2543 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2545 CONFIG_SYS_I2C_DTT_ADDR:
2547 If defined, specifies the I2C address of the DTT device.
2548 If not defined, then U-Boot uses predefined value for
2549 specified DTT device.
2551 CONFIG_SOFT_I2C_READ_REPEATED_START
2553 defining this will force the i2c_read() function in
2554 the soft_i2c driver to perform an I2C repeated start
2555 between writing the address pointer and reading the
2556 data. If this define is omitted the default behaviour
2557 of doing a stop-start sequence will be used. Most I2C
2558 devices can use either method, but some require one or
2561 - SPI Support: CONFIG_SPI
2563 Enables SPI driver (so far only tested with
2564 SPI EEPROM, also an instance works with Crystal A/D and
2565 D/As on the SACSng board)
2569 Enables the driver for SPI controller on SuperH. Currently
2570 only SH7757 is supported.
2574 Enables extended (16-bit) SPI EEPROM addressing.
2575 (symmetrical to CONFIG_I2C_X)
2579 Enables a software (bit-bang) SPI driver rather than
2580 using hardware support. This is a general purpose
2581 driver that only requires three general I/O port pins
2582 (two outputs, one input) to function. If this is
2583 defined, the board configuration must define several
2584 SPI configuration items (port pins to use, etc). For
2585 an example, see include/configs/sacsng.h.
2589 Enables a hardware SPI driver for general-purpose reads
2590 and writes. As with CONFIG_SOFT_SPI, the board configuration
2591 must define a list of chip-select function pointers.
2592 Currently supported on some MPC8xxx processors. For an
2593 example, see include/configs/mpc8349emds.h.
2597 Enables the driver for the SPI controllers on i.MX and MXC
2598 SoCs. Currently i.MX31/35/51 are supported.
2600 - FPGA Support: CONFIG_FPGA
2602 Enables FPGA subsystem.
2604 CONFIG_FPGA_<vendor>
2606 Enables support for specific chip vendors.
2609 CONFIG_FPGA_<family>
2611 Enables support for FPGA family.
2612 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2616 Specify the number of FPGA devices to support.
2618 CONFIG_CMD_FPGA_LOADMK
2620 Enable support for fpga loadmk command
2622 CONFIG_CMD_FPGA_LOADP
2624 Enable support for fpga loadp command - load partial bitstream
2626 CONFIG_CMD_FPGA_LOADBP
2628 Enable support for fpga loadbp command - load partial bitstream
2631 CONFIG_SYS_FPGA_PROG_FEEDBACK
2633 Enable printing of hash marks during FPGA configuration.
2635 CONFIG_SYS_FPGA_CHECK_BUSY
2637 Enable checks on FPGA configuration interface busy
2638 status by the configuration function. This option
2639 will require a board or device specific function to
2644 If defined, a function that provides delays in the FPGA
2645 configuration driver.
2647 CONFIG_SYS_FPGA_CHECK_CTRLC
2648 Allow Control-C to interrupt FPGA configuration
2650 CONFIG_SYS_FPGA_CHECK_ERROR
2652 Check for configuration errors during FPGA bitfile
2653 loading. For example, abort during Virtex II
2654 configuration if the INIT_B line goes low (which
2655 indicated a CRC error).
2657 CONFIG_SYS_FPGA_WAIT_INIT
2659 Maximum time to wait for the INIT_B line to deassert
2660 after PROB_B has been deasserted during a Virtex II
2661 FPGA configuration sequence. The default time is 500
2664 CONFIG_SYS_FPGA_WAIT_BUSY
2666 Maximum time to wait for BUSY to deassert during
2667 Virtex II FPGA configuration. The default is 5 ms.
2669 CONFIG_SYS_FPGA_WAIT_CONFIG
2671 Time to wait after FPGA configuration. The default is
2674 - Configuration Management:
2677 If defined, this string will be added to the U-Boot
2678 version information (U_BOOT_VERSION)
2680 - Vendor Parameter Protection:
2682 U-Boot considers the values of the environment
2683 variables "serial#" (Board Serial Number) and
2684 "ethaddr" (Ethernet Address) to be parameters that
2685 are set once by the board vendor / manufacturer, and
2686 protects these variables from casual modification by
2687 the user. Once set, these variables are read-only,
2688 and write or delete attempts are rejected. You can
2689 change this behaviour:
2691 If CONFIG_ENV_OVERWRITE is #defined in your config
2692 file, the write protection for vendor parameters is
2693 completely disabled. Anybody can change or delete
2696 Alternatively, if you #define _both_ CONFIG_ETHADDR
2697 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2698 Ethernet address is installed in the environment,
2699 which can be changed exactly ONCE by the user. [The
2700 serial# is unaffected by this, i. e. it remains
2703 The same can be accomplished in a more flexible way
2704 for any variable by configuring the type of access
2705 to allow for those variables in the ".flags" variable
2706 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2711 Define this variable to enable the reservation of
2712 "protected RAM", i. e. RAM which is not overwritten
2713 by U-Boot. Define CONFIG_PRAM to hold the number of
2714 kB you want to reserve for pRAM. You can overwrite
2715 this default value by defining an environment
2716 variable "pram" to the number of kB you want to
2717 reserve. Note that the board info structure will
2718 still show the full amount of RAM. If pRAM is
2719 reserved, a new environment variable "mem" will
2720 automatically be defined to hold the amount of
2721 remaining RAM in a form that can be passed as boot
2722 argument to Linux, for instance like that:
2724 setenv bootargs ... mem=\${mem}
2727 This way you can tell Linux not to use this memory,
2728 either, which results in a memory region that will
2729 not be affected by reboots.
2731 *WARNING* If your board configuration uses automatic
2732 detection of the RAM size, you must make sure that
2733 this memory test is non-destructive. So far, the
2734 following board configurations are known to be
2737 IVMS8, IVML24, SPD8xx, TQM8xxL,
2738 HERMES, IP860, RPXlite, LWMON,
2741 - Access to physical memory region (> 4GB)
2742 Some basic support is provided for operations on memory not
2743 normally accessible to U-Boot - e.g. some architectures
2744 support access to more than 4GB of memory on 32-bit
2745 machines using physical address extension or similar.
2746 Define CONFIG_PHYSMEM to access this basic support, which
2747 currently only supports clearing the memory.
2752 Define this variable to stop the system in case of a
2753 fatal error, so that you have to reset it manually.
2754 This is probably NOT a good idea for an embedded
2755 system where you want the system to reboot
2756 automatically as fast as possible, but it may be
2757 useful during development since you can try to debug
2758 the conditions that lead to the situation.
2760 CONFIG_NET_RETRY_COUNT
2762 This variable defines the number of retries for
2763 network operations like ARP, RARP, TFTP, or BOOTP
2764 before giving up the operation. If not defined, a
2765 default value of 5 is used.
2769 Timeout waiting for an ARP reply in milliseconds.
2773 Timeout in milliseconds used in NFS protocol.
2774 If you encounter "ERROR: Cannot umount" in nfs command,
2775 try longer timeout such as
2776 #define CONFIG_NFS_TIMEOUT 10000UL
2778 - Command Interpreter:
2779 CONFIG_AUTO_COMPLETE
2781 Enable auto completion of commands using TAB.
2783 Note that this feature has NOT been implemented yet
2784 for the "hush" shell.
2787 CONFIG_SYS_HUSH_PARSER
2789 Define this variable to enable the "hush" shell (from
2790 Busybox) as command line interpreter, thus enabling
2791 powerful command line syntax like
2792 if...then...else...fi conditionals or `&&' and '||'
2793 constructs ("shell scripts").
2795 If undefined, you get the old, much simpler behaviour
2796 with a somewhat smaller memory footprint.
2799 CONFIG_SYS_PROMPT_HUSH_PS2
2801 This defines the secondary prompt string, which is
2802 printed when the command interpreter needs more input
2803 to complete a command. Usually "> ".
2807 In the current implementation, the local variables
2808 space and global environment variables space are
2809 separated. Local variables are those you define by
2810 simply typing `name=value'. To access a local
2811 variable later on, you have write `$name' or
2812 `${name}'; to execute the contents of a variable
2813 directly type `$name' at the command prompt.
2815 Global environment variables are those you use
2816 setenv/printenv to work with. To run a command stored
2817 in such a variable, you need to use the run command,
2818 and you must not use the '$' sign to access them.
2820 To store commands and special characters in a
2821 variable, please use double quotation marks
2822 surrounding the whole text of the variable, instead
2823 of the backslashes before semicolons and special
2826 - Commandline Editing and History:
2827 CONFIG_CMDLINE_EDITING
2829 Enable editing and History functions for interactive
2830 commandline input operations
2832 - Default Environment:
2833 CONFIG_EXTRA_ENV_SETTINGS
2835 Define this to contain any number of null terminated
2836 strings (variable = value pairs) that will be part of
2837 the default environment compiled into the boot image.
2839 For example, place something like this in your
2840 board's config file:
2842 #define CONFIG_EXTRA_ENV_SETTINGS \
2846 Warning: This method is based on knowledge about the
2847 internal format how the environment is stored by the
2848 U-Boot code. This is NOT an official, exported
2849 interface! Although it is unlikely that this format
2850 will change soon, there is no guarantee either.
2851 You better know what you are doing here.
2853 Note: overly (ab)use of the default environment is
2854 discouraged. Make sure to check other ways to preset
2855 the environment like the "source" command or the
2858 CONFIG_ENV_VARS_UBOOT_CONFIG
2860 Define this in order to add variables describing the
2861 U-Boot build configuration to the default environment.
2862 These will be named arch, cpu, board, vendor, and soc.
2864 Enabling this option will cause the following to be defined:
2872 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2874 Define this in order to add variables describing certain
2875 run-time determined information about the hardware to the
2876 environment. These will be named board_name, board_rev.
2878 CONFIG_DELAY_ENVIRONMENT
2880 Normally the environment is loaded when the board is
2881 intialised so that it is available to U-Boot. This inhibits
2882 that so that the environment is not available until
2883 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2884 this is instead controlled by the value of
2885 /config/load-environment.
2887 - DataFlash Support:
2888 CONFIG_HAS_DATAFLASH
2890 Defining this option enables DataFlash features and
2891 allows to read/write in Dataflash via the standard
2894 - Serial Flash support
2897 Defining this option enables SPI flash commands
2898 'sf probe/read/write/erase/update'.
2900 Usage requires an initial 'probe' to define the serial
2901 flash parameters, followed by read/write/erase/update
2904 The following defaults may be provided by the platform
2905 to handle the common case when only a single serial
2906 flash is present on the system.
2908 CONFIG_SF_DEFAULT_BUS Bus identifier
2909 CONFIG_SF_DEFAULT_CS Chip-select
2910 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2911 CONFIG_SF_DEFAULT_SPEED in Hz
2915 Define this option to include a destructive SPI flash
2918 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2920 Define this option to use the Bank addr/Extended addr
2921 support on SPI flashes which has size > 16Mbytes.
2923 CONFIG_SF_DUAL_FLASH Dual flash memories
2925 Define this option to use dual flash support where two flash
2926 memories can be connected with a given cs line.
2927 currently Xilinx Zynq qspi support these type of connections.
2929 - SystemACE Support:
2932 Adding this option adds support for Xilinx SystemACE
2933 chips attached via some sort of local bus. The address
2934 of the chip must also be defined in the
2935 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2937 #define CONFIG_SYSTEMACE
2938 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2940 When SystemACE support is added, the "ace" device type
2941 becomes available to the fat commands, i.e. fatls.
2943 - TFTP Fixed UDP Port:
2946 If this is defined, the environment variable tftpsrcp
2947 is used to supply the TFTP UDP source port value.
2948 If tftpsrcp isn't defined, the normal pseudo-random port
2949 number generator is used.
2951 Also, the environment variable tftpdstp is used to supply
2952 the TFTP UDP destination port value. If tftpdstp isn't
2953 defined, the normal port 69 is used.
2955 The purpose for tftpsrcp is to allow a TFTP server to
2956 blindly start the TFTP transfer using the pre-configured
2957 target IP address and UDP port. This has the effect of
2958 "punching through" the (Windows XP) firewall, allowing
2959 the remainder of the TFTP transfer to proceed normally.
2960 A better solution is to properly configure the firewall,
2961 but sometimes that is not allowed.
2966 This enables a generic 'hash' command which can produce
2967 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2971 Enable the hash verify command (hash -v). This adds to code
2974 CONFIG_SHA1 - support SHA1 hashing
2975 CONFIG_SHA256 - support SHA256 hashing
2977 Note: There is also a sha1sum command, which should perhaps
2978 be deprecated in favour of 'hash sha1'.
2980 - Freescale i.MX specific commands:
2981 CONFIG_CMD_HDMIDETECT
2982 This enables 'hdmidet' command which returns true if an
2983 HDMI monitor is detected. This command is i.MX 6 specific.
2986 This enables the 'bmode' (bootmode) command for forcing
2987 a boot from specific media.
2989 This is useful for forcing the ROM's usb downloader to
2990 activate upon a watchdog reset which is nice when iterating
2991 on U-Boot. Using the reset button or running bmode normal
2992 will set it back to normal. This command currently
2993 supports i.MX53 and i.MX6.
2998 This enables the RSA algorithm used for FIT image verification
2999 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3001 The signing part is build into mkimage regardless of this
3004 - bootcount support:
3005 CONFIG_BOOTCOUNT_LIMIT
3007 This enables the bootcounter support, see:
3008 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3011 enable special bootcounter support on at91sam9xe based boards.
3013 enable special bootcounter support on blackfin based boards.
3015 enable special bootcounter support on da850 based boards.
3016 CONFIG_BOOTCOUNT_RAM
3017 enable support for the bootcounter in RAM
3018 CONFIG_BOOTCOUNT_I2C
3019 enable support for the bootcounter on an i2c (like RTC) device.
3020 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3021 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3023 CONFIG_BOOTCOUNT_ALEN = address len
3025 - Show boot progress:
3026 CONFIG_SHOW_BOOT_PROGRESS
3028 Defining this option allows to add some board-
3029 specific code (calling a user-provided function
3030 "show_boot_progress(int)") that enables you to show
3031 the system's boot progress on some display (for
3032 example, some LED's) on your board. At the moment,
3033 the following checkpoints are implemented:
3035 - Detailed boot stage timing
3037 Define this option to get detailed timing of each stage
3038 of the boot process.
3040 CONFIG_BOOTSTAGE_USER_COUNT
3041 This is the number of available user bootstage records.
3042 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3043 a new ID will be allocated from this stash. If you exceed
3044 the limit, recording will stop.
3046 CONFIG_BOOTSTAGE_REPORT
3047 Define this to print a report before boot, similar to this:
3049 Timer summary in microseconds:
3052 3,575,678 3,575,678 board_init_f start
3053 3,575,695 17 arch_cpu_init A9
3054 3,575,777 82 arch_cpu_init done
3055 3,659,598 83,821 board_init_r start
3056 3,910,375 250,777 main_loop
3057 29,916,167 26,005,792 bootm_start
3058 30,361,327 445,160 start_kernel
3060 CONFIG_CMD_BOOTSTAGE
3061 Add a 'bootstage' command which supports printing a report
3062 and un/stashing of bootstage data.
3064 CONFIG_BOOTSTAGE_FDT
3065 Stash the bootstage information in the FDT. A root 'bootstage'
3066 node is created with each bootstage id as a child. Each child
3067 has a 'name' property and either 'mark' containing the
3068 mark time in microsecond, or 'accum' containing the
3069 accumulated time for that bootstage id in microseconds.
3074 name = "board_init_f";
3083 Code in the Linux kernel can find this in /proc/devicetree.
3085 Legacy uImage format:
3088 1 common/cmd_bootm.c before attempting to boot an image
3089 -1 common/cmd_bootm.c Image header has bad magic number
3090 2 common/cmd_bootm.c Image header has correct magic number
3091 -2 common/cmd_bootm.c Image header has bad checksum
3092 3 common/cmd_bootm.c Image header has correct checksum
3093 -3 common/cmd_bootm.c Image data has bad checksum
3094 4 common/cmd_bootm.c Image data has correct checksum
3095 -4 common/cmd_bootm.c Image is for unsupported architecture
3096 5 common/cmd_bootm.c Architecture check OK
3097 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3098 6 common/cmd_bootm.c Image Type check OK
3099 -6 common/cmd_bootm.c gunzip uncompression error
3100 -7 common/cmd_bootm.c Unimplemented compression type
3101 7 common/cmd_bootm.c Uncompression OK
3102 8 common/cmd_bootm.c No uncompress/copy overwrite error
3103 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3105 9 common/image.c Start initial ramdisk verification
3106 -10 common/image.c Ramdisk header has bad magic number
3107 -11 common/image.c Ramdisk header has bad checksum
3108 10 common/image.c Ramdisk header is OK
3109 -12 common/image.c Ramdisk data has bad checksum
3110 11 common/image.c Ramdisk data has correct checksum
3111 12 common/image.c Ramdisk verification complete, start loading
3112 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3113 13 common/image.c Start multifile image verification
3114 14 common/image.c No initial ramdisk, no multifile, continue.
3116 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3118 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3119 -31 post/post.c POST test failed, detected by post_output_backlog()
3120 -32 post/post.c POST test failed, detected by post_run_single()
3122 34 common/cmd_doc.c before loading a Image from a DOC device
3123 -35 common/cmd_doc.c Bad usage of "doc" command
3124 35 common/cmd_doc.c correct usage of "doc" command
3125 -36 common/cmd_doc.c No boot device
3126 36 common/cmd_doc.c correct boot device
3127 -37 common/cmd_doc.c Unknown Chip ID on boot device
3128 37 common/cmd_doc.c correct chip ID found, device available
3129 -38 common/cmd_doc.c Read Error on boot device
3130 38 common/cmd_doc.c reading Image header from DOC device OK
3131 -39 common/cmd_doc.c Image header has bad magic number
3132 39 common/cmd_doc.c Image header has correct magic number
3133 -40 common/cmd_doc.c Error reading Image from DOC device
3134 40 common/cmd_doc.c Image header has correct magic number
3135 41 common/cmd_ide.c before loading a Image from a IDE device
3136 -42 common/cmd_ide.c Bad usage of "ide" command
3137 42 common/cmd_ide.c correct usage of "ide" command
3138 -43 common/cmd_ide.c No boot device
3139 43 common/cmd_ide.c boot device found
3140 -44 common/cmd_ide.c Device not available
3141 44 common/cmd_ide.c Device available
3142 -45 common/cmd_ide.c wrong partition selected
3143 45 common/cmd_ide.c partition selected
3144 -46 common/cmd_ide.c Unknown partition table
3145 46 common/cmd_ide.c valid partition table found
3146 -47 common/cmd_ide.c Invalid partition type
3147 47 common/cmd_ide.c correct partition type
3148 -48 common/cmd_ide.c Error reading Image Header on boot device
3149 48 common/cmd_ide.c reading Image Header from IDE device OK
3150 -49 common/cmd_ide.c Image header has bad magic number
3151 49 common/cmd_ide.c Image header has correct magic number
3152 -50 common/cmd_ide.c Image header has bad checksum
3153 50 common/cmd_ide.c Image header has correct checksum
3154 -51 common/cmd_ide.c Error reading Image from IDE device
3155 51 common/cmd_ide.c reading Image from IDE device OK
3156 52 common/cmd_nand.c before loading a Image from a NAND device
3157 -53 common/cmd_nand.c Bad usage of "nand" command
3158 53 common/cmd_nand.c correct usage of "nand" command
3159 -54 common/cmd_nand.c No boot device
3160 54 common/cmd_nand.c boot device found
3161 -55 common/cmd_nand.c Unknown Chip ID on boot device
3162 55 common/cmd_nand.c correct chip ID found, device available
3163 -56 common/cmd_nand.c Error reading Image Header on boot device
3164 56 common/cmd_nand.c reading Image Header from NAND device OK
3165 -57 common/cmd_nand.c Image header has bad magic number
3166 57 common/cmd_nand.c Image header has correct magic number
3167 -58 common/cmd_nand.c Error reading Image from NAND device
3168 58 common/cmd_nand.c reading Image from NAND device OK
3170 -60 common/env_common.c Environment has a bad CRC, using default
3172 64 net/eth.c starting with Ethernet configuration.
3173 -64 net/eth.c no Ethernet found.
3174 65 net/eth.c Ethernet found.
3176 -80 common/cmd_net.c usage wrong
3177 80 common/cmd_net.c before calling NetLoop()
3178 -81 common/cmd_net.c some error in NetLoop() occurred
3179 81 common/cmd_net.c NetLoop() back without error
3180 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3181 82 common/cmd_net.c trying automatic boot
3182 83 common/cmd_net.c running "source" command
3183 -83 common/cmd_net.c some error in automatic boot or "source" command
3184 84 common/cmd_net.c end without errors
3189 100 common/cmd_bootm.c Kernel FIT Image has correct format
3190 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3191 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3192 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3193 102 common/cmd_bootm.c Kernel unit name specified
3194 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3195 103 common/cmd_bootm.c Found configuration node
3196 104 common/cmd_bootm.c Got kernel subimage node offset
3197 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3198 105 common/cmd_bootm.c Kernel subimage hash verification OK
3199 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3200 106 common/cmd_bootm.c Architecture check OK
3201 -106 common/cmd_bootm.c Kernel subimage has wrong type
3202 107 common/cmd_bootm.c Kernel subimage type OK
3203 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3204 108 common/cmd_bootm.c Got kernel subimage data/size
3205 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3206 -109 common/cmd_bootm.c Can't get kernel subimage type
3207 -110 common/cmd_bootm.c Can't get kernel subimage comp
3208 -111 common/cmd_bootm.c Can't get kernel subimage os
3209 -112 common/cmd_bootm.c Can't get kernel subimage load address
3210 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3212 120 common/image.c Start initial ramdisk verification
3213 -120 common/image.c Ramdisk FIT image has incorrect format
3214 121 common/image.c Ramdisk FIT image has correct format
3215 122 common/image.c No ramdisk subimage unit name, using configuration
3216 -122 common/image.c Can't get configuration for ramdisk subimage
3217 123 common/image.c Ramdisk unit name specified
3218 -124 common/image.c Can't get ramdisk subimage node offset
3219 125 common/image.c Got ramdisk subimage node offset
3220 -125 common/image.c Ramdisk subimage hash verification failed
3221 126 common/image.c Ramdisk subimage hash verification OK
3222 -126 common/image.c Ramdisk subimage for unsupported architecture
3223 127 common/image.c Architecture check OK
3224 -127 common/image.c Can't get ramdisk subimage data/size
3225 128 common/image.c Got ramdisk subimage data/size
3226 129 common/image.c Can't get ramdisk load address
3227 -129 common/image.c Got ramdisk load address
3229 -130 common/cmd_doc.c Incorrect FIT image format
3230 131 common/cmd_doc.c FIT image format OK
3232 -140 common/cmd_ide.c Incorrect FIT image format
3233 141 common/cmd_ide.c FIT image format OK
3235 -150 common/cmd_nand.c Incorrect FIT image format
3236 151 common/cmd_nand.c FIT image format OK
3238 - legacy image format:
3239 CONFIG_IMAGE_FORMAT_LEGACY
3240 enables the legacy image format support in U-Boot.
3243 enabled if CONFIG_FIT_SIGNATURE is not defined.
3245 CONFIG_DISABLE_IMAGE_LEGACY
3246 disable the legacy image format
3248 This define is introduced, as the legacy image format is
3249 enabled per default for backward compatibility.
3251 - FIT image support:
3253 Enable support for the FIT uImage format.
3255 CONFIG_FIT_BEST_MATCH
3256 When no configuration is explicitly selected, default to the
3257 one whose fdt's compatibility field best matches that of
3258 U-Boot itself. A match is considered "best" if it matches the
3259 most specific compatibility entry of U-Boot's fdt's root node.
3260 The order of entries in the configuration's fdt is ignored.
3262 CONFIG_FIT_SIGNATURE
3263 This option enables signature verification of FIT uImages,
3264 using a hash signed and verified using RSA. See
3265 doc/uImage.FIT/signature.txt for more details.
3267 WARNING: When relying on signed FIT images with required
3268 signature check the legacy image format is default
3269 disabled. If a board need legacy image format support
3270 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3272 CONFIG_FIT_DISABLE_SHA256
3273 Supporting SHA256 hashes has quite an impact on binary size.
3274 For constrained systems sha256 hash support can be disabled
3277 - Standalone program support:
3278 CONFIG_STANDALONE_LOAD_ADDR
3280 This option defines a board specific value for the
3281 address where standalone program gets loaded, thus
3282 overwriting the architecture dependent default
3285 - Frame Buffer Address:
3288 Define CONFIG_FB_ADDR if you want to use specific
3289 address for frame buffer. This is typically the case
3290 when using a graphics controller has separate video
3291 memory. U-Boot will then place the frame buffer at
3292 the given address instead of dynamically reserving it
3293 in system RAM by calling lcd_setmem(), which grabs
3294 the memory for the frame buffer depending on the
3295 configured panel size.
3297 Please see board_init_f function.
3299 - Automatic software updates via TFTP server
3301 CONFIG_UPDATE_TFTP_CNT_MAX
3302 CONFIG_UPDATE_TFTP_MSEC_MAX
3304 These options enable and control the auto-update feature;
3305 for a more detailed description refer to doc/README.update.
3307 - MTD Support (mtdparts command, UBI support)
3310 Adds the MTD device infrastructure from the Linux kernel.
3311 Needed for mtdparts command support.
3313 CONFIG_MTD_PARTITIONS
3315 Adds the MTD partitioning infrastructure from the Linux
3316 kernel. Needed for UBI support.
3321 Adds commands for interacting with MTD partitions formatted
3322 with the UBI flash translation layer
3324 Requires also defining CONFIG_RBTREE
3326 CONFIG_UBI_SILENCE_MSG
3328 Make the verbose messages from UBI stop printing. This leaves
3329 warnings and errors enabled.
3334 Adds commands for interacting with UBI volumes formatted as
3335 UBIFS. UBIFS is read-only in u-boot.
3337 Requires UBI support as well as CONFIG_LZO
3339 CONFIG_UBIFS_SILENCE_MSG
3341 Make the verbose messages from UBIFS stop printing. This leaves
3342 warnings and errors enabled.
3346 Enable building of SPL globally.
3349 LDSCRIPT for linking the SPL binary.
3351 CONFIG_SPL_MAX_FOOTPRINT
3352 Maximum size in memory allocated to the SPL, BSS included.
3353 When defined, the linker checks that the actual memory
3354 used by SPL from _start to __bss_end does not exceed it.
3355 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3356 must not be both defined at the same time.
3359 Maximum size of the SPL image (text, data, rodata, and
3360 linker lists sections), BSS excluded.
3361 When defined, the linker checks that the actual size does
3364 CONFIG_SPL_TEXT_BASE
3365 TEXT_BASE for linking the SPL binary.
3367 CONFIG_SPL_RELOC_TEXT_BASE
3368 Address to relocate to. If unspecified, this is equal to
3369 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3371 CONFIG_SPL_BSS_START_ADDR
3372 Link address for the BSS within the SPL binary.
3374 CONFIG_SPL_BSS_MAX_SIZE
3375 Maximum size in memory allocated to the SPL BSS.
3376 When defined, the linker checks that the actual memory used
3377 by SPL from __bss_start to __bss_end does not exceed it.
3378 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3379 must not be both defined at the same time.
3382 Adress of the start of the stack SPL will use
3384 CONFIG_SPL_RELOC_STACK
3385 Adress of the start of the stack SPL will use after
3386 relocation. If unspecified, this is equal to
3389 CONFIG_SYS_SPL_MALLOC_START
3390 Starting address of the malloc pool used in SPL.
3392 CONFIG_SYS_SPL_MALLOC_SIZE
3393 The size of the malloc pool used in SPL.
3395 CONFIG_SPL_FRAMEWORK
3396 Enable the SPL framework under common/. This framework
3397 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3398 NAND loading of the Linux Kernel.
3401 Enable booting directly to an OS from SPL.
3402 See also: doc/README.falcon
3404 CONFIG_SPL_DISPLAY_PRINT
3405 For ARM, enable an optional function to print more information
3406 about the running system.
3408 CONFIG_SPL_INIT_MINIMAL
3409 Arch init code should be built for a very small image
3411 CONFIG_SPL_LIBCOMMON_SUPPORT
3412 Support for common/libcommon.o in SPL binary
3414 CONFIG_SPL_LIBDISK_SUPPORT
3415 Support for disk/libdisk.o in SPL binary
3417 CONFIG_SPL_I2C_SUPPORT
3418 Support for drivers/i2c/libi2c.o in SPL binary
3420 CONFIG_SPL_GPIO_SUPPORT
3421 Support for drivers/gpio/libgpio.o in SPL binary
3423 CONFIG_SPL_MMC_SUPPORT
3424 Support for drivers/mmc/libmmc.o in SPL binary
3426 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3427 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3428 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3429 Address, size and partition on the MMC to load U-Boot from
3430 when the MMC is being used in raw mode.
3432 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3433 Sector to load kernel uImage from when MMC is being
3434 used in raw mode (for Falcon mode)
3436 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3437 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3438 Sector and number of sectors to load kernel argument
3439 parameters from when MMC is being used in raw mode
3442 CONFIG_SPL_FAT_SUPPORT
3443 Support for fs/fat/libfat.o in SPL binary
3445 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3446 Filename to read to load U-Boot when reading from FAT
3448 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3449 Filename to read to load kernel uImage when reading
3450 from FAT (for Falcon mode)
3452 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3453 Filename to read to load kernel argument parameters
3454 when reading from FAT (for Falcon mode)
3456 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3457 Set this for NAND SPL on PPC mpc83xx targets, so that
3458 start.S waits for the rest of the SPL to load before
3459 continuing (the hardware starts execution after just
3460 loading the first page rather than the full 4K).
3462 CONFIG_SPL_SKIP_RELOCATE
3463 Avoid SPL relocation
3465 CONFIG_SPL_NAND_BASE
3466 Include nand_base.c in the SPL. Requires
3467 CONFIG_SPL_NAND_DRIVERS.
3469 CONFIG_SPL_NAND_DRIVERS
3470 SPL uses normal NAND drivers, not minimal drivers.
3473 Include standard software ECC in the SPL
3475 CONFIG_SPL_NAND_SIMPLE
3476 Support for NAND boot using simple NAND drivers that
3477 expose the cmd_ctrl() interface.
3479 CONFIG_SPL_MTD_SUPPORT
3480 Support for the MTD subsystem within SPL. Useful for
3481 environment on NAND support within SPL.
3483 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3484 Set for the SPL on PPC mpc8xxx targets, support for
3485 drivers/ddr/fsl/libddr.o in SPL binary.
3487 CONFIG_SPL_COMMON_INIT_DDR
3488 Set for common ddr init with serial presence detect in
3491 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3492 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3493 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3494 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3495 CONFIG_SYS_NAND_ECCBYTES
3496 Defines the size and behavior of the NAND that SPL uses
3499 CONFIG_SPL_NAND_BOOT
3500 Add support NAND boot
3502 CONFIG_SYS_NAND_U_BOOT_OFFS
3503 Location in NAND to read U-Boot from
3505 CONFIG_SYS_NAND_U_BOOT_DST
3506 Location in memory to load U-Boot to
3508 CONFIG_SYS_NAND_U_BOOT_SIZE
3509 Size of image to load
3511 CONFIG_SYS_NAND_U_BOOT_START
3512 Entry point in loaded image to jump to
3514 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3515 Define this if you need to first read the OOB and then the
3516 data. This is used for example on davinci plattforms.
3518 CONFIG_SPL_OMAP3_ID_NAND
3519 Support for an OMAP3-specific set of functions to return the
3520 ID and MFR of the first attached NAND chip, if present.
3522 CONFIG_SPL_SERIAL_SUPPORT
3523 Support for drivers/serial/libserial.o in SPL binary
3525 CONFIG_SPL_SPI_FLASH_SUPPORT
3526 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3528 CONFIG_SPL_SPI_SUPPORT
3529 Support for drivers/spi/libspi.o in SPL binary
3531 CONFIG_SPL_RAM_DEVICE
3532 Support for running image already present in ram, in SPL binary
3534 CONFIG_SPL_LIBGENERIC_SUPPORT
3535 Support for lib/libgeneric.o in SPL binary
3537 CONFIG_SPL_ENV_SUPPORT
3538 Support for the environment operating in SPL binary
3540 CONFIG_SPL_NET_SUPPORT
3541 Support for the net/libnet.o in SPL binary.
3542 It conflicts with SPL env from storage medium specified by
3543 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3546 Image offset to which the SPL should be padded before appending
3547 the SPL payload. By default, this is defined as
3548 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3549 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3550 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3553 Final target image containing SPL and payload. Some SPLs
3554 use an arch-specific makefile fragment instead, for
3555 example if more than one image needs to be produced.
3557 CONFIG_FIT_SPL_PRINT
3558 Printing information about a FIT image adds quite a bit of
3559 code to SPL. So this is normally disabled in SPL. Use this
3560 option to re-enable it. This will affect the output of the
3561 bootm command when booting a FIT image.
3565 Enable building of TPL globally.
3568 Image offset to which the TPL should be padded before appending
3569 the TPL 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.
3577 [so far only for SMDK2400 boards]
3579 - Modem support enable:
3580 CONFIG_MODEM_SUPPORT
3582 - RTS/CTS Flow control enable:
3585 - Modem debug support:
3586 CONFIG_MODEM_SUPPORT_DEBUG
3588 Enables debugging stuff (char screen[1024], dbg())
3589 for modem support. Useful only with BDI2000.
3591 - Interrupt support (PPC):
3593 There are common interrupt_init() and timer_interrupt()
3594 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3595 for CPU specific initialization. interrupt_init_cpu()
3596 should set decrementer_count to appropriate value. If
3597 CPU resets decrementer automatically after interrupt
3598 (ppc4xx) it should set decrementer_count to zero.
3599 timer_interrupt() calls timer_interrupt_cpu() for CPU
3600 specific handling. If board has watchdog / status_led
3601 / other_activity_monitor it works automatically from
3602 general timer_interrupt().
3606 In the target system modem support is enabled when a
3607 specific key (key combination) is pressed during
3608 power-on. Otherwise U-Boot will boot normally
3609 (autoboot). The key_pressed() function is called from
3610 board_init(). Currently key_pressed() is a dummy
3611 function, returning 1 and thus enabling modem
3614 If there are no modem init strings in the
3615 environment, U-Boot proceed to autoboot; the
3616 previous output (banner, info printfs) will be
3619 See also: doc/README.Modem
3621 Board initialization settings:
3622 ------------------------------
3624 During Initialization u-boot calls a number of board specific functions
3625 to allow the preparation of board specific prerequisites, e.g. pin setup
3626 before drivers are initialized. To enable these callbacks the
3627 following configuration macros have to be defined. Currently this is
3628 architecture specific, so please check arch/your_architecture/lib/board.c
3629 typically in board_init_f() and board_init_r().
3631 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3632 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3633 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3634 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3636 Configuration Settings:
3637 -----------------------
3639 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3640 Optionally it can be defined to support 64-bit memory commands.
3642 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3643 undefine this when you're short of memory.
3645 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3646 width of the commands listed in the 'help' command output.
3648 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3649 prompt for user input.
3651 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3653 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3655 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3657 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3658 the application (usually a Linux kernel) when it is
3661 - CONFIG_SYS_BAUDRATE_TABLE:
3662 List of legal baudrate settings for this board.
3664 - CONFIG_SYS_CONSOLE_INFO_QUIET
3665 Suppress display of console information at boot.
3667 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3668 If the board specific function
3669 extern int overwrite_console (void);
3670 returns 1, the stdin, stderr and stdout are switched to the
3671 serial port, else the settings in the environment are used.
3673 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3674 Enable the call to overwrite_console().
3676 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3677 Enable overwrite of previous console environment settings.
3679 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3680 Begin and End addresses of the area used by the
3683 - CONFIG_SYS_ALT_MEMTEST:
3684 Enable an alternate, more extensive memory test.
3686 - CONFIG_SYS_MEMTEST_SCRATCH:
3687 Scratch address used by the alternate memory test
3688 You only need to set this if address zero isn't writeable
3690 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3691 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3692 this specified memory area will get subtracted from the top
3693 (end) of RAM and won't get "touched" at all by U-Boot. By
3694 fixing up gd->ram_size the Linux kernel should gets passed
3695 the now "corrected" memory size and won't touch it either.
3696 This should work for arch/ppc and arch/powerpc. Only Linux
3697 board ports in arch/powerpc with bootwrapper support that
3698 recalculate the memory size from the SDRAM controller setup
3699 will have to get fixed in Linux additionally.
3701 This option can be used as a workaround for the 440EPx/GRx
3702 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3705 WARNING: Please make sure that this value is a multiple of
3706 the Linux page size (normally 4k). If this is not the case,
3707 then the end address of the Linux memory will be located at a
3708 non page size aligned address and this could cause major
3711 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3712 Enable temporary baudrate change while serial download
3714 - CONFIG_SYS_SDRAM_BASE:
3715 Physical start address of SDRAM. _Must_ be 0 here.
3717 - CONFIG_SYS_MBIO_BASE:
3718 Physical start address of Motherboard I/O (if using a
3721 - CONFIG_SYS_FLASH_BASE:
3722 Physical start address of Flash memory.
3724 - CONFIG_SYS_MONITOR_BASE:
3725 Physical start address of boot monitor code (set by
3726 make config files to be same as the text base address
3727 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3728 CONFIG_SYS_FLASH_BASE when booting from flash.
3730 - CONFIG_SYS_MONITOR_LEN:
3731 Size of memory reserved for monitor code, used to
3732 determine _at_compile_time_ (!) if the environment is
3733 embedded within the U-Boot image, or in a separate
3736 - CONFIG_SYS_MALLOC_LEN:
3737 Size of DRAM reserved for malloc() use.
3739 - CONFIG_SYS_BOOTM_LEN:
3740 Normally compressed uImages are limited to an
3741 uncompressed size of 8 MBytes. If this is not enough,
3742 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3743 to adjust this setting to your needs.
3745 - CONFIG_SYS_BOOTMAPSZ:
3746 Maximum size of memory mapped by the startup code of
3747 the Linux kernel; all data that must be processed by
3748 the Linux kernel (bd_info, boot arguments, FDT blob if
3749 used) must be put below this limit, unless "bootm_low"
3750 environment variable is defined and non-zero. In such case
3751 all data for the Linux kernel must be between "bootm_low"
3752 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3753 variable "bootm_mapsize" will override the value of
3754 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3755 then the value in "bootm_size" will be used instead.
3757 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3758 Enable initrd_high functionality. If defined then the
3759 initrd_high feature is enabled and the bootm ramdisk subcommand
3762 - CONFIG_SYS_BOOT_GET_CMDLINE:
3763 Enables allocating and saving kernel cmdline in space between
3764 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3766 - CONFIG_SYS_BOOT_GET_KBD:
3767 Enables allocating and saving a kernel copy of the bd_info in
3768 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3770 - CONFIG_SYS_MAX_FLASH_BANKS:
3771 Max number of Flash memory banks
3773 - CONFIG_SYS_MAX_FLASH_SECT:
3774 Max number of sectors on a Flash chip
3776 - CONFIG_SYS_FLASH_ERASE_TOUT:
3777 Timeout for Flash erase operations (in ms)
3779 - CONFIG_SYS_FLASH_WRITE_TOUT:
3780 Timeout for Flash write operations (in ms)
3782 - CONFIG_SYS_FLASH_LOCK_TOUT
3783 Timeout for Flash set sector lock bit operation (in ms)
3785 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3786 Timeout for Flash clear lock bits operation (in ms)
3788 - CONFIG_SYS_FLASH_PROTECTION
3789 If defined, hardware flash sectors protection is used
3790 instead of U-Boot software protection.
3792 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3794 Enable TFTP transfers directly to flash memory;
3795 without this option such a download has to be
3796 performed in two steps: (1) download to RAM, and (2)
3797 copy from RAM to flash.
3799 The two-step approach is usually more reliable, since
3800 you can check if the download worked before you erase
3801 the flash, but in some situations (when system RAM is
3802 too limited to allow for a temporary copy of the
3803 downloaded image) this option may be very useful.
3805 - CONFIG_SYS_FLASH_CFI:
3806 Define if the flash driver uses extra elements in the
3807 common flash structure for storing flash geometry.
3809 - CONFIG_FLASH_CFI_DRIVER
3810 This option also enables the building of the cfi_flash driver
3811 in the drivers directory
3813 - CONFIG_FLASH_CFI_MTD
3814 This option enables the building of the cfi_mtd driver
3815 in the drivers directory. The driver exports CFI flash
3818 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3819 Use buffered writes to flash.
3821 - CONFIG_FLASH_SPANSION_S29WS_N
3822 s29ws-n MirrorBit flash has non-standard addresses for buffered
3825 - CONFIG_SYS_FLASH_QUIET_TEST
3826 If this option is defined, the common CFI flash doesn't
3827 print it's warning upon not recognized FLASH banks. This
3828 is useful, if some of the configured banks are only
3829 optionally available.
3831 - CONFIG_FLASH_SHOW_PROGRESS
3832 If defined (must be an integer), print out countdown
3833 digits and dots. Recommended value: 45 (9..1) for 80
3834 column displays, 15 (3..1) for 40 column displays.
3836 - CONFIG_FLASH_VERIFY
3837 If defined, the content of the flash (destination) is compared
3838 against the source after the write operation. An error message
3839 will be printed when the contents are not identical.
3840 Please note that this option is useless in nearly all cases,
3841 since such flash programming errors usually are detected earlier
3842 while unprotecting/erasing/programming. Please only enable
3843 this option if you really know what you are doing.
3845 - CONFIG_SYS_RX_ETH_BUFFER:
3846 Defines the number of Ethernet receive buffers. On some
3847 Ethernet controllers it is recommended to set this value
3848 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3849 buffers can be full shortly after enabling the interface
3850 on high Ethernet traffic.
3851 Defaults to 4 if not defined.
3853 - CONFIG_ENV_MAX_ENTRIES
3855 Maximum number of entries in the hash table that is used
3856 internally to store the environment settings. The default
3857 setting is supposed to be generous and should work in most
3858 cases. This setting can be used to tune behaviour; see
3859 lib/hashtable.c for details.
3861 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3862 - CONFIG_ENV_FLAGS_LIST_STATIC
3863 Enable validation of the values given to environment variables when
3864 calling env set. Variables can be restricted to only decimal,
3865 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3866 the variables can also be restricted to IP address or MAC address.
3868 The format of the list is:
3869 type_attribute = [s|d|x|b|i|m]
3870 access_atribute = [a|r|o|c]
3871 attributes = type_attribute[access_atribute]
3872 entry = variable_name[:attributes]
3875 The type attributes are:
3876 s - String (default)
3879 b - Boolean ([1yYtT|0nNfF])
3883 The access attributes are:
3889 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3890 Define this to a list (string) to define the ".flags"
3891 envirnoment variable in the default or embedded environment.
3893 - CONFIG_ENV_FLAGS_LIST_STATIC
3894 Define this to a list (string) to define validation that
3895 should be done if an entry is not found in the ".flags"
3896 environment variable. To override a setting in the static
3897 list, simply add an entry for the same variable name to the
3900 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3901 If defined, don't allow the -f switch to env set override variable
3904 - CONFIG_SYS_GENERIC_BOARD
3905 This selects the architecture-generic board system instead of the
3906 architecture-specific board files. It is intended to move boards
3907 to this new framework over time. Defining this will disable the
3908 arch/foo/lib/board.c file and use common/board_f.c and
3909 common/board_r.c instead. To use this option your architecture
3910 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3911 its config.mk file). If you find problems enabling this option on
3912 your board please report the problem and send patches!
3914 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3915 This is set by OMAP boards for the max time that reset should
3916 be asserted. See doc/README.omap-reset-time for details on how
3917 the value can be calulated on a given board.
3919 The following definitions that deal with the placement and management
3920 of environment data (variable area); in general, we support the
3921 following configurations:
3923 - CONFIG_BUILD_ENVCRC:
3925 Builds up envcrc with the target environment so that external utils
3926 may easily extract it and embed it in final U-Boot images.
3928 - CONFIG_ENV_IS_IN_FLASH:
3930 Define this if the environment is in flash memory.
3932 a) The environment occupies one whole flash sector, which is
3933 "embedded" in the text segment with the U-Boot code. This
3934 happens usually with "bottom boot sector" or "top boot
3935 sector" type flash chips, which have several smaller
3936 sectors at the start or the end. For instance, such a
3937 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3938 such a case you would place the environment in one of the
3939 4 kB sectors - with U-Boot code before and after it. With
3940 "top boot sector" type flash chips, you would put the
3941 environment in one of the last sectors, leaving a gap
3942 between U-Boot and the environment.
3944 - CONFIG_ENV_OFFSET:
3946 Offset of environment data (variable area) to the
3947 beginning of flash memory; for instance, with bottom boot
3948 type flash chips the second sector can be used: the offset
3949 for this sector is given here.
3951 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3955 This is just another way to specify the start address of
3956 the flash sector containing the environment (instead of
3959 - CONFIG_ENV_SECT_SIZE:
3961 Size of the sector containing the environment.
3964 b) Sometimes flash chips have few, equal sized, BIG sectors.
3965 In such a case you don't want to spend a whole sector for
3970 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3971 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3972 of this flash sector for the environment. This saves
3973 memory for the RAM copy of the environment.
3975 It may also save flash memory if you decide to use this
3976 when your environment is "embedded" within U-Boot code,
3977 since then the remainder of the flash sector could be used
3978 for U-Boot code. It should be pointed out that this is
3979 STRONGLY DISCOURAGED from a robustness point of view:
3980 updating the environment in flash makes it always
3981 necessary to erase the WHOLE sector. If something goes
3982 wrong before the contents has been restored from a copy in
3983 RAM, your target system will be dead.
3985 - CONFIG_ENV_ADDR_REDUND
3986 CONFIG_ENV_SIZE_REDUND
3988 These settings describe a second storage area used to hold
3989 a redundant copy of the environment data, so that there is
3990 a valid backup copy in case there is a power failure during
3991 a "saveenv" operation.
3993 BE CAREFUL! Any changes to the flash layout, and some changes to the
3994 source code will make it necessary to adapt <board>/u-boot.lds*
3998 - CONFIG_ENV_IS_IN_NVRAM:
4000 Define this if you have some non-volatile memory device
4001 (NVRAM, battery buffered SRAM) which you want to use for the
4007 These two #defines are used to determine the memory area you
4008 want to use for environment. It is assumed that this memory
4009 can just be read and written to, without any special
4012 BE CAREFUL! The first access to the environment happens quite early
4013 in U-Boot initalization (when we try to get the setting of for the
4014 console baudrate). You *MUST* have mapped your NVRAM area then, or
4017 Please note that even with NVRAM we still use a copy of the
4018 environment in RAM: we could work on NVRAM directly, but we want to
4019 keep settings there always unmodified except somebody uses "saveenv"
4020 to save the current settings.
4023 - CONFIG_ENV_IS_IN_EEPROM:
4025 Use this if you have an EEPROM or similar serial access
4026 device and a driver for it.
4028 - CONFIG_ENV_OFFSET:
4031 These two #defines specify the offset and size of the
4032 environment area within the total memory of your EEPROM.
4034 - CONFIG_SYS_I2C_EEPROM_ADDR:
4035 If defined, specified the chip address of the EEPROM device.
4036 The default address is zero.
4038 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4039 If defined, the number of bits used to address bytes in a
4040 single page in the EEPROM device. A 64 byte page, for example
4041 would require six bits.
4043 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4044 If defined, the number of milliseconds to delay between
4045 page writes. The default is zero milliseconds.
4047 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4048 The length in bytes of the EEPROM memory array address. Note
4049 that this is NOT the chip address length!
4051 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4052 EEPROM chips that implement "address overflow" are ones
4053 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4054 address and the extra bits end up in the "chip address" bit
4055 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4058 Note that we consider the length of the address field to
4059 still be one byte because the extra address bits are hidden
4060 in the chip address.
4062 - CONFIG_SYS_EEPROM_SIZE:
4063 The size in bytes of the EEPROM device.
4065 - CONFIG_ENV_EEPROM_IS_ON_I2C
4066 define this, if you have I2C and SPI activated, and your
4067 EEPROM, which holds the environment, is on the I2C bus.
4069 - CONFIG_I2C_ENV_EEPROM_BUS
4070 if you have an Environment on an EEPROM reached over
4071 I2C muxes, you can define here, how to reach this
4072 EEPROM. For example:
4074 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4076 EEPROM which holds the environment, is reached over
4077 a pca9547 i2c mux with address 0x70, channel 3.
4079 - CONFIG_ENV_IS_IN_DATAFLASH:
4081 Define this if you have a DataFlash memory device which you
4082 want to use for the environment.
4084 - CONFIG_ENV_OFFSET:
4088 These three #defines specify the offset and size of the
4089 environment area within the total memory of your DataFlash placed
4090 at the specified address.
4092 - CONFIG_ENV_IS_IN_SPI_FLASH:
4094 Define this if you have a SPI Flash memory device which you
4095 want to use for the environment.
4097 - CONFIG_ENV_OFFSET:
4100 These two #defines specify the offset and size of the
4101 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4102 aligned to an erase sector boundary.
4104 - CONFIG_ENV_SECT_SIZE:
4106 Define the SPI flash's sector size.
4108 - CONFIG_ENV_OFFSET_REDUND (optional):
4110 This setting describes a second storage area of CONFIG_ENV_SIZE
4111 size used to hold a redundant copy of the environment data, so
4112 that there is a valid backup copy in case there is a power failure
4113 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4114 aligned to an erase sector boundary.
4116 - CONFIG_ENV_SPI_BUS (optional):
4117 - CONFIG_ENV_SPI_CS (optional):
4119 Define the SPI bus and chip select. If not defined they will be 0.
4121 - CONFIG_ENV_SPI_MAX_HZ (optional):
4123 Define the SPI max work clock. If not defined then use 1MHz.
4125 - CONFIG_ENV_SPI_MODE (optional):
4127 Define the SPI work mode. If not defined then use SPI_MODE_3.
4129 - CONFIG_ENV_IS_IN_REMOTE:
4131 Define this if you have a remote memory space which you
4132 want to use for the local device's environment.
4137 These two #defines specify the address and size of the
4138 environment area within the remote memory space. The
4139 local device can get the environment from remote memory
4140 space by SRIO or PCIE links.
4142 BE CAREFUL! For some special cases, the local device can not use
4143 "saveenv" command. For example, the local device will get the
4144 environment stored in a remote NOR flash by SRIO or PCIE link,
4145 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4147 - CONFIG_ENV_IS_IN_NAND:
4149 Define this if you have a NAND device which you want to use
4150 for the environment.
4152 - CONFIG_ENV_OFFSET:
4155 These two #defines specify the offset and size of the environment
4156 area within the first NAND device. CONFIG_ENV_OFFSET must be
4157 aligned to an erase block boundary.
4159 - CONFIG_ENV_OFFSET_REDUND (optional):
4161 This setting describes a second storage area of CONFIG_ENV_SIZE
4162 size used to hold a redundant copy of the environment data, so
4163 that there is a valid backup copy in case there is a power failure
4164 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4165 aligned to an erase block boundary.
4167 - CONFIG_ENV_RANGE (optional):
4169 Specifies the length of the region in which the environment
4170 can be written. This should be a multiple of the NAND device's
4171 block size. Specifying a range with more erase blocks than
4172 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4173 the range to be avoided.
4175 - CONFIG_ENV_OFFSET_OOB (optional):
4177 Enables support for dynamically retrieving the offset of the
4178 environment from block zero's out-of-band data. The
4179 "nand env.oob" command can be used to record this offset.
4180 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4181 using CONFIG_ENV_OFFSET_OOB.
4183 - CONFIG_NAND_ENV_DST
4185 Defines address in RAM to which the nand_spl code should copy the
4186 environment. If redundant environment is used, it will be copied to
4187 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4189 - CONFIG_ENV_IS_IN_UBI:
4191 Define this if you have an UBI volume that you want to use for the
4192 environment. This has the benefit of wear-leveling the environment
4193 accesses, which is important on NAND.
4195 - CONFIG_ENV_UBI_PART:
4197 Define this to a string that is the mtd partition containing the UBI.
4199 - CONFIG_ENV_UBI_VOLUME:
4201 Define this to the name of the volume that you want to store the
4204 - CONFIG_ENV_UBI_VOLUME_REDUND:
4206 Define this to the name of another volume to store a second copy of
4207 the environment in. This will enable redundant environments in UBI.
4208 It is assumed that both volumes are in the same MTD partition.
4210 - CONFIG_UBI_SILENCE_MSG
4211 - CONFIG_UBIFS_SILENCE_MSG
4213 You will probably want to define these to avoid a really noisy system
4214 when storing the env in UBI.
4216 - CONFIG_ENV_IS_IN_FAT:
4217 Define this if you want to use the FAT file system for the environment.
4219 - FAT_ENV_INTERFACE:
4221 Define this to a string that is the name of the block device.
4223 - FAT_ENV_DEV_AND_PART:
4225 Define this to a string to specify the partition of the device. It can
4228 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4229 - "D:P": device D partition P. Error occurs if device D has no
4232 - "D" or "D:": device D partition 1 if device D has partition
4233 table, or the whole device D if has no partition
4235 - "D:auto": first partition in device D with bootable flag set.
4236 If none, first valid paratition in device D. If no
4237 partition table then means device D.
4241 It's a string of the FAT file name. This file use to store the
4245 This should be defined. Otherwise it cannot save the envrionment file.
4247 - CONFIG_ENV_IS_IN_MMC:
4249 Define this if you have an MMC device which you want to use for the
4252 - CONFIG_SYS_MMC_ENV_DEV:
4254 Specifies which MMC device the environment is stored in.
4256 - CONFIG_SYS_MMC_ENV_PART (optional):
4258 Specifies which MMC partition the environment is stored in. If not
4259 set, defaults to partition 0, the user area. Common values might be
4260 1 (first MMC boot partition), 2 (second MMC boot partition).
4262 - CONFIG_ENV_OFFSET:
4265 These two #defines specify the offset and size of the environment
4266 area within the specified MMC device.
4268 If offset is positive (the usual case), it is treated as relative to
4269 the start of the MMC partition. If offset is negative, it is treated
4270 as relative to the end of the MMC partition. This can be useful if
4271 your board may be fitted with different MMC devices, which have
4272 different sizes for the MMC partitions, and you always want the
4273 environment placed at the very end of the partition, to leave the
4274 maximum possible space before it, to store other data.
4276 These two values are in units of bytes, but must be aligned to an
4277 MMC sector boundary.
4279 - CONFIG_ENV_OFFSET_REDUND (optional):
4281 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4282 hold a redundant copy of the environment data. This provides a
4283 valid backup copy in case the other copy is corrupted, e.g. due
4284 to a power failure during a "saveenv" operation.
4286 This value may also be positive or negative; this is handled in the
4287 same way as CONFIG_ENV_OFFSET.
4289 This value is also in units of bytes, but must also be aligned to
4290 an MMC sector boundary.
4292 - CONFIG_ENV_SIZE_REDUND (optional):
4294 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4295 set. If this value is set, it must be set to the same value as
4298 - CONFIG_SYS_SPI_INIT_OFFSET
4300 Defines offset to the initial SPI buffer area in DPRAM. The
4301 area is used at an early stage (ROM part) if the environment
4302 is configured to reside in the SPI EEPROM: We need a 520 byte
4303 scratch DPRAM area. It is used between the two initialization
4304 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4305 to be a good choice since it makes it far enough from the
4306 start of the data area as well as from the stack pointer.
4308 Please note that the environment is read-only until the monitor
4309 has been relocated to RAM and a RAM copy of the environment has been
4310 created; also, when using EEPROM you will have to use getenv_f()
4311 until then to read environment variables.
4313 The environment is protected by a CRC32 checksum. Before the monitor
4314 is relocated into RAM, as a result of a bad CRC you will be working
4315 with the compiled-in default environment - *silently*!!! [This is
4316 necessary, because the first environment variable we need is the
4317 "baudrate" setting for the console - if we have a bad CRC, we don't
4318 have any device yet where we could complain.]
4320 Note: once the monitor has been relocated, then it will complain if
4321 the default environment is used; a new CRC is computed as soon as you
4322 use the "saveenv" command to store a valid environment.
4324 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4325 Echo the inverted Ethernet link state to the fault LED.
4327 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4328 also needs to be defined.
4330 - CONFIG_SYS_FAULT_MII_ADDR:
4331 MII address of the PHY to check for the Ethernet link state.
4333 - CONFIG_NS16550_MIN_FUNCTIONS:
4334 Define this if you desire to only have use of the NS16550_init
4335 and NS16550_putc functions for the serial driver located at
4336 drivers/serial/ns16550.c. This option is useful for saving
4337 space for already greatly restricted images, including but not
4338 limited to NAND_SPL configurations.
4340 - CONFIG_DISPLAY_BOARDINFO
4341 Display information about the board that U-Boot is running on
4342 when U-Boot starts up. The board function checkboard() is called
4345 - CONFIG_DISPLAY_BOARDINFO_LATE
4346 Similar to the previous option, but display this information
4347 later, once stdio is running and output goes to the LCD, if
4350 Low Level (hardware related) configuration options:
4351 ---------------------------------------------------
4353 - CONFIG_SYS_CACHELINE_SIZE:
4354 Cache Line Size of the CPU.
4356 - CONFIG_SYS_DEFAULT_IMMR:
4357 Default address of the IMMR after system reset.
4359 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4360 and RPXsuper) to be able to adjust the position of
4361 the IMMR register after a reset.
4363 - CONFIG_SYS_CCSRBAR_DEFAULT:
4364 Default (power-on reset) physical address of CCSR on Freescale
4367 - CONFIG_SYS_CCSRBAR:
4368 Virtual address of CCSR. On a 32-bit build, this is typically
4369 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4371 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4372 for cross-platform code that uses that macro instead.
4374 - CONFIG_SYS_CCSRBAR_PHYS:
4375 Physical address of CCSR. CCSR can be relocated to a new
4376 physical address, if desired. In this case, this macro should
4377 be set to that address. Otherwise, it should be set to the
4378 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4379 is typically relocated on 36-bit builds. It is recommended
4380 that this macro be defined via the _HIGH and _LOW macros:
4382 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4383 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4385 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4386 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4387 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4388 used in assembly code, so it must not contain typecasts or
4389 integer size suffixes (e.g. "ULL").
4391 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4392 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4393 used in assembly code, so it must not contain typecasts or
4394 integer size suffixes (e.g. "ULL").
4396 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4397 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4398 forced to a value that ensures that CCSR is not relocated.
4400 - Floppy Disk Support:
4401 CONFIG_SYS_FDC_DRIVE_NUMBER
4403 the default drive number (default value 0)
4405 CONFIG_SYS_ISA_IO_STRIDE
4407 defines the spacing between FDC chipset registers
4410 CONFIG_SYS_ISA_IO_OFFSET
4412 defines the offset of register from address. It
4413 depends on which part of the data bus is connected to
4414 the FDC chipset. (default value 0)
4416 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4417 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4420 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4421 fdc_hw_init() is called at the beginning of the FDC
4422 setup. fdc_hw_init() must be provided by the board
4423 source code. It is used to make hardware dependant
4427 Most IDE controllers were designed to be connected with PCI
4428 interface. Only few of them were designed for AHB interface.
4429 When software is doing ATA command and data transfer to
4430 IDE devices through IDE-AHB controller, some additional
4431 registers accessing to these kind of IDE-AHB controller
4434 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4435 DO NOT CHANGE unless you know exactly what you're
4436 doing! (11-4) [MPC8xx/82xx systems only]
4438 - CONFIG_SYS_INIT_RAM_ADDR:
4440 Start address of memory area that can be used for
4441 initial data and stack; please note that this must be
4442 writable memory that is working WITHOUT special
4443 initialization, i. e. you CANNOT use normal RAM which
4444 will become available only after programming the
4445 memory controller and running certain initialization
4448 U-Boot uses the following memory types:
4449 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4450 - MPC824X: data cache
4451 - PPC4xx: data cache
4453 - CONFIG_SYS_GBL_DATA_OFFSET:
4455 Offset of the initial data structure in the memory
4456 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4457 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4458 data is located at the end of the available space
4459 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4460 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4461 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4462 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4465 On the MPC824X (or other systems that use the data
4466 cache for initial memory) the address chosen for
4467 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4468 point to an otherwise UNUSED address space between
4469 the top of RAM and the start of the PCI space.
4471 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4473 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4475 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4477 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4479 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4481 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4483 - CONFIG_SYS_OR_TIMING_SDRAM:
4486 - CONFIG_SYS_MAMR_PTA:
4487 periodic timer for refresh
4489 - CONFIG_SYS_DER: Debug Event Register (37-47)
4491 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4492 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4493 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4494 CONFIG_SYS_BR1_PRELIM:
4495 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4497 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4498 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4499 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4500 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4502 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4503 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4504 Machine Mode Register and Memory Periodic Timer
4505 Prescaler definitions (SDRAM timing)
4507 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4508 enable I2C microcode relocation patch (MPC8xx);
4509 define relocation offset in DPRAM [DSP2]
4511 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4512 enable SMC microcode relocation patch (MPC8xx);
4513 define relocation offset in DPRAM [SMC1]
4515 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4516 enable SPI microcode relocation patch (MPC8xx);
4517 define relocation offset in DPRAM [SCC4]
4519 - CONFIG_SYS_USE_OSCCLK:
4520 Use OSCM clock mode on MBX8xx board. Be careful,
4521 wrong setting might damage your board. Read
4522 doc/README.MBX before setting this variable!
4524 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4525 Offset of the bootmode word in DPRAM used by post
4526 (Power On Self Tests). This definition overrides
4527 #define'd default value in commproc.h resp.
4530 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4531 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4532 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4533 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4534 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4535 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4536 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4537 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4538 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4540 - CONFIG_PCI_DISABLE_PCIE:
4541 Disable PCI-Express on systems where it is supported but not
4544 - CONFIG_PCI_ENUM_ONLY
4545 Only scan through and get the devices on the busses.
4546 Don't do any setup work, presumably because someone or
4547 something has already done it, and we don't need to do it
4548 a second time. Useful for platforms that are pre-booted
4549 by coreboot or similar.
4551 - CONFIG_PCI_INDIRECT_BRIDGE:
4552 Enable support for indirect PCI bridges.
4555 Chip has SRIO or not
4558 Board has SRIO 1 port available
4561 Board has SRIO 2 port available
4563 - CONFIG_SRIO_PCIE_BOOT_MASTER
4564 Board can support master function for Boot from SRIO and PCIE
4566 - CONFIG_SYS_SRIOn_MEM_VIRT:
4567 Virtual Address of SRIO port 'n' memory region
4569 - CONFIG_SYS_SRIOn_MEM_PHYS:
4570 Physical Address of SRIO port 'n' memory region
4572 - CONFIG_SYS_SRIOn_MEM_SIZE:
4573 Size of SRIO port 'n' memory region
4575 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4576 Defined to tell the NAND controller that the NAND chip is using
4578 Not all NAND drivers use this symbol.
4579 Example of drivers that use it:
4580 - drivers/mtd/nand/ndfc.c
4581 - drivers/mtd/nand/mxc_nand.c
4583 - CONFIG_SYS_NDFC_EBC0_CFG
4584 Sets the EBC0_CFG register for the NDFC. If not defined
4585 a default value will be used.
4588 Get DDR timing information from an I2C EEPROM. Common
4589 with pluggable memory modules such as SODIMMs
4592 I2C address of the SPD EEPROM
4594 - CONFIG_SYS_SPD_BUS_NUM
4595 If SPD EEPROM is on an I2C bus other than the first
4596 one, specify here. Note that the value must resolve
4597 to something your driver can deal with.
4599 - CONFIG_SYS_DDR_RAW_TIMING
4600 Get DDR timing information from other than SPD. Common with
4601 soldered DDR chips onboard without SPD. DDR raw timing
4602 parameters are extracted from datasheet and hard-coded into
4603 header files or board specific files.
4605 - CONFIG_FSL_DDR_INTERACTIVE
4606 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4608 - CONFIG_SYS_83XX_DDR_USES_CS0
4609 Only for 83xx systems. If specified, then DDR should
4610 be configured using CS0 and CS1 instead of CS2 and CS3.
4612 - CONFIG_ETHER_ON_FEC[12]
4613 Define to enable FEC[12] on a 8xx series processor.
4615 - CONFIG_FEC[12]_PHY
4616 Define to the hardcoded PHY address which corresponds
4617 to the given FEC; i. e.
4618 #define CONFIG_FEC1_PHY 4
4619 means that the PHY with address 4 is connected to FEC1
4621 When set to -1, means to probe for first available.
4623 - CONFIG_FEC[12]_PHY_NORXERR
4624 The PHY does not have a RXERR line (RMII only).
4625 (so program the FEC to ignore it).
4628 Enable RMII mode for all FECs.
4629 Note that this is a global option, we can't
4630 have one FEC in standard MII mode and another in RMII mode.
4632 - CONFIG_CRC32_VERIFY
4633 Add a verify option to the crc32 command.
4636 => crc32 -v <address> <count> <crc32>
4638 Where address/count indicate a memory area
4639 and crc32 is the correct crc32 which the
4643 Add the "loopw" memory command. This only takes effect if
4644 the memory commands are activated globally (CONFIG_CMD_MEM).
4647 Add the "mdc" and "mwc" memory commands. These are cyclic
4652 This command will print 4 bytes (10,11,12,13) each 500 ms.
4654 => mwc.l 100 12345678 10
4655 This command will write 12345678 to address 100 all 10 ms.
4657 This only takes effect if the memory commands are activated
4658 globally (CONFIG_CMD_MEM).
4660 - CONFIG_SKIP_LOWLEVEL_INIT
4661 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4662 low level initializations (like setting up the memory
4663 controller) are omitted and/or U-Boot does not
4664 relocate itself into RAM.
4666 Normally this variable MUST NOT be defined. The only
4667 exception is when U-Boot is loaded (to RAM) by some
4668 other boot loader or by a debugger which performs
4669 these initializations itself.
4672 Modifies the behaviour of start.S when compiling a loader
4673 that is executed before the actual U-Boot. E.g. when
4674 compiling a NAND SPL.
4677 Modifies the behaviour of start.S when compiling a loader
4678 that is executed after the SPL and before the actual U-Boot.
4679 It is loaded by the SPL.
4681 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4682 Only for 85xx systems. If this variable is specified, the section
4683 .resetvec is not kept and the section .bootpg is placed in the
4684 previous 4k of the .text section.
4686 - CONFIG_ARCH_MAP_SYSMEM
4687 Generally U-Boot (and in particular the md command) uses
4688 effective address. It is therefore not necessary to regard
4689 U-Boot address as virtual addresses that need to be translated
4690 to physical addresses. However, sandbox requires this, since
4691 it maintains its own little RAM buffer which contains all
4692 addressable memory. This option causes some memory accesses
4693 to be mapped through map_sysmem() / unmap_sysmem().
4695 - CONFIG_USE_ARCH_MEMCPY
4696 CONFIG_USE_ARCH_MEMSET
4697 If these options are used a optimized version of memcpy/memset will
4698 be used if available. These functions may be faster under some
4699 conditions but may increase the binary size.
4701 - CONFIG_X86_RESET_VECTOR
4702 If defined, the x86 reset vector code is included. This is not
4703 needed when U-Boot is running from Coreboot.
4706 Defines the MPU clock speed (in MHz).
4708 NOTE : currently only supported on AM335x platforms.
4710 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4711 Enables the RTC32K OSC on AM33xx based plattforms
4713 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4714 Option to disable subpage write in NAND driver
4715 driver that uses this:
4716 drivers/mtd/nand/davinci_nand.c
4718 Freescale QE/FMAN Firmware Support:
4719 -----------------------------------
4721 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4722 loading of "firmware", which is encoded in the QE firmware binary format.
4723 This firmware often needs to be loaded during U-Boot booting, so macros
4724 are used to identify the storage device (NOR flash, SPI, etc) and the address
4727 - CONFIG_SYS_FMAN_FW_ADDR
4728 The address in the storage device where the FMAN microcode is located. The
4729 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4732 - CONFIG_SYS_QE_FW_ADDR
4733 The address in the storage device where the QE microcode is located. The
4734 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4737 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4738 The maximum possible size of the firmware. The firmware binary format
4739 has a field that specifies the actual size of the firmware, but it
4740 might not be possible to read any part of the firmware unless some
4741 local storage is allocated to hold the entire firmware first.
4743 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4744 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4745 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4746 virtual address in NOR flash.
4748 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4749 Specifies that QE/FMAN firmware is located in NAND flash.
4750 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4752 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4753 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4754 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4756 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4757 Specifies that QE/FMAN firmware is located on the primary SPI
4758 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4760 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4761 Specifies that QE/FMAN firmware is located in the remote (master)
4762 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4763 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4764 window->master inbound window->master LAW->the ucode address in
4765 master's memory space.
4767 Freescale Layerscape Management Complex Firmware Support:
4768 ---------------------------------------------------------
4769 The Freescale Layerscape Management Complex (MC) supports the loading of
4771 This firmware often needs to be loaded during U-Boot booting, so macros
4772 are used to identify the storage device (NOR flash, SPI, etc) and the address
4775 - CONFIG_FSL_MC_ENET
4776 Enable the MC driver for Layerscape SoCs.
4778 - CONFIG_SYS_LS_MC_FW_ADDR
4779 The address in the storage device where the firmware is located. The
4780 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4783 - CONFIG_SYS_LS_MC_FW_LENGTH
4784 The maximum possible size of the firmware. The firmware binary format
4785 has a field that specifies the actual size of the firmware, but it
4786 might not be possible to read any part of the firmware unless some
4787 local storage is allocated to hold the entire firmware first.
4789 - CONFIG_SYS_LS_MC_FW_IN_NOR
4790 Specifies that MC firmware is located in NOR flash, mapped as
4791 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4792 virtual address in NOR flash.
4794 Building the Software:
4795 ======================
4797 Building U-Boot has been tested in several native build environments
4798 and in many different cross environments. Of course we cannot support
4799 all possibly existing versions of cross development tools in all
4800 (potentially obsolete) versions. In case of tool chain problems we
4801 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4802 which is extensively used to build and test U-Boot.
4804 If you are not using a native environment, it is assumed that you
4805 have GNU cross compiling tools available in your path. In this case,
4806 you must set the environment variable CROSS_COMPILE in your shell.
4807 Note that no changes to the Makefile or any other source files are
4808 necessary. For example using the ELDK on a 4xx CPU, please enter:
4810 $ CROSS_COMPILE=ppc_4xx-
4811 $ export CROSS_COMPILE
4813 Note: If you wish to generate Windows versions of the utilities in
4814 the tools directory you can use the MinGW toolchain
4815 (http://www.mingw.org). Set your HOST tools to the MinGW
4816 toolchain and execute 'make tools'. For example:
4818 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4820 Binaries such as tools/mkimage.exe will be created which can
4821 be executed on computers running Windows.
4823 U-Boot is intended to be simple to build. After installing the
4824 sources you must configure U-Boot for one specific board type. This
4829 where "NAME_config" is the name of one of the existing configu-
4830 rations; see boards.cfg for supported names.
4832 Note: for some board special configuration names may exist; check if
4833 additional information is available from the board vendor; for
4834 instance, the TQM823L systems are available without (standard)
4835 or with LCD support. You can select such additional "features"
4836 when choosing the configuration, i. e.
4839 - will configure for a plain TQM823L, i. e. no LCD support
4841 make TQM823L_LCD_config
4842 - will configure for a TQM823L with U-Boot console on LCD
4847 Finally, type "make all", and you should get some working U-Boot
4848 images ready for download to / installation on your system:
4850 - "u-boot.bin" is a raw binary image
4851 - "u-boot" is an image in ELF binary format
4852 - "u-boot.srec" is in Motorola S-Record format
4854 By default the build is performed locally and the objects are saved
4855 in the source directory. One of the two methods can be used to change
4856 this behavior and build U-Boot to some external directory:
4858 1. Add O= to the make command line invocations:
4860 make O=/tmp/build distclean
4861 make O=/tmp/build NAME_config
4862 make O=/tmp/build all
4864 2. Set environment variable BUILD_DIR to point to the desired location:
4866 export BUILD_DIR=/tmp/build
4871 Note that the command line "O=" setting overrides the BUILD_DIR environment
4875 Please be aware that the Makefiles assume you are using GNU make, so
4876 for instance on NetBSD you might need to use "gmake" instead of
4880 If the system board that you have is not listed, then you will need
4881 to port U-Boot to your hardware platform. To do this, follow these
4884 1. Add a new configuration option for your board to the toplevel
4885 "boards.cfg" file, using the existing entries as examples.
4886 Follow the instructions there to keep the boards in order.
4887 2. Create a new directory to hold your board specific code. Add any
4888 files you need. In your board directory, you will need at least
4889 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4890 3. Create a new configuration file "include/configs/<board>.h" for
4892 3. If you're porting U-Boot to a new CPU, then also create a new
4893 directory to hold your CPU specific code. Add any files you need.
4894 4. Run "make <board>_config" with your new name.
4895 5. Type "make", and you should get a working "u-boot.srec" file
4896 to be installed on your target system.
4897 6. Debug and solve any problems that might arise.
4898 [Of course, this last step is much harder than it sounds.]
4901 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4902 ==============================================================
4904 If you have modified U-Boot sources (for instance added a new board
4905 or support for new devices, a new CPU, etc.) you are expected to
4906 provide feedback to the other developers. The feedback normally takes
4907 the form of a "patch", i. e. a context diff against a certain (latest
4908 official or latest in the git repository) version of U-Boot sources.
4910 But before you submit such a patch, please verify that your modifi-
4911 cation did not break existing code. At least make sure that *ALL* of
4912 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4913 just run the "MAKEALL" script, which will configure and build U-Boot
4914 for ALL supported system. Be warned, this will take a while. You can
4915 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4916 environment variable to the script, i. e. to use the ELDK cross tools
4919 CROSS_COMPILE=ppc_8xx- MAKEALL
4921 or to build on a native PowerPC system you can type
4923 CROSS_COMPILE=' ' MAKEALL
4925 When using the MAKEALL script, the default behaviour is to build
4926 U-Boot in the source directory. This location can be changed by
4927 setting the BUILD_DIR environment variable. Also, for each target
4928 built, the MAKEALL script saves two log files (<target>.ERR and
4929 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4930 location can be changed by setting the MAKEALL_LOGDIR environment
4931 variable. For example:
4933 export BUILD_DIR=/tmp/build
4934 export MAKEALL_LOGDIR=/tmp/log
4935 CROSS_COMPILE=ppc_8xx- MAKEALL
4937 With the above settings build objects are saved in the /tmp/build,
4938 log files are saved in the /tmp/log and the source tree remains clean
4939 during the whole build process.
4942 See also "U-Boot Porting Guide" below.
4945 Monitor Commands - Overview:
4946 ============================
4948 go - start application at address 'addr'
4949 run - run commands in an environment variable
4950 bootm - boot application image from memory
4951 bootp - boot image via network using BootP/TFTP protocol
4952 bootz - boot zImage from memory
4953 tftpboot- boot image via network using TFTP protocol
4954 and env variables "ipaddr" and "serverip"
4955 (and eventually "gatewayip")
4956 tftpput - upload a file via network using TFTP protocol
4957 rarpboot- boot image via network using RARP/TFTP protocol
4958 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4959 loads - load S-Record file over serial line
4960 loadb - load binary file over serial line (kermit mode)
4962 mm - memory modify (auto-incrementing)
4963 nm - memory modify (constant address)
4964 mw - memory write (fill)
4966 cmp - memory compare
4967 crc32 - checksum calculation
4968 i2c - I2C sub-system
4969 sspi - SPI utility commands
4970 base - print or set address offset
4971 printenv- print environment variables
4972 setenv - set environment variables
4973 saveenv - save environment variables to persistent storage
4974 protect - enable or disable FLASH write protection
4975 erase - erase FLASH memory
4976 flinfo - print FLASH memory information
4977 nand - NAND memory operations (see doc/README.nand)
4978 bdinfo - print Board Info structure
4979 iminfo - print header information for application image
4980 coninfo - print console devices and informations
4981 ide - IDE sub-system
4982 loop - infinite loop on address range
4983 loopw - infinite write loop on address range
4984 mtest - simple RAM test
4985 icache - enable or disable instruction cache
4986 dcache - enable or disable data cache
4987 reset - Perform RESET of the CPU
4988 echo - echo args to console
4989 version - print monitor version
4990 help - print online help
4991 ? - alias for 'help'
4994 Monitor Commands - Detailed Description:
4995 ========================================
4999 For now: just type "help <command>".
5002 Environment Variables:
5003 ======================
5005 U-Boot supports user configuration using Environment Variables which
5006 can be made persistent by saving to Flash memory.
5008 Environment Variables are set using "setenv", printed using
5009 "printenv", and saved to Flash using "saveenv". Using "setenv"
5010 without a value can be used to delete a variable from the
5011 environment. As long as you don't save the environment you are
5012 working with an in-memory copy. In case the Flash area containing the
5013 environment is erased by accident, a default environment is provided.
5015 Some configuration options can be set using Environment Variables.
5017 List of environment variables (most likely not complete):
5019 baudrate - see CONFIG_BAUDRATE
5021 bootdelay - see CONFIG_BOOTDELAY
5023 bootcmd - see CONFIG_BOOTCOMMAND
5025 bootargs - Boot arguments when booting an RTOS image
5027 bootfile - Name of the image to load with TFTP
5029 bootm_low - Memory range available for image processing in the bootm
5030 command can be restricted. This variable is given as
5031 a hexadecimal number and defines lowest address allowed
5032 for use by the bootm command. See also "bootm_size"
5033 environment variable. Address defined by "bootm_low" is
5034 also the base of the initial memory mapping for the Linux
5035 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5038 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5039 This variable is given as a hexadecimal number and it
5040 defines the size of the memory region starting at base
5041 address bootm_low that is accessible by the Linux kernel
5042 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5043 as the default value if it is defined, and bootm_size is
5046 bootm_size - Memory range available for image processing in the bootm
5047 command can be restricted. This variable is given as
5048 a hexadecimal number and defines the size of the region
5049 allowed for use by the bootm command. See also "bootm_low"
5050 environment variable.
5052 updatefile - Location of the software update file on a TFTP server, used
5053 by the automatic software update feature. Please refer to
5054 documentation in doc/README.update for more details.
5056 autoload - if set to "no" (any string beginning with 'n'),
5057 "bootp" will just load perform a lookup of the
5058 configuration from the BOOTP server, but not try to
5059 load any image using TFTP
5061 autostart - if set to "yes", an image loaded using the "bootp",
5062 "rarpboot", "tftpboot" or "diskboot" commands will
5063 be automatically started (by internally calling
5066 If set to "no", a standalone image passed to the
5067 "bootm" command will be copied to the load address
5068 (and eventually uncompressed), but NOT be started.
5069 This can be used to load and uncompress arbitrary
5072 fdt_high - if set this restricts the maximum address that the
5073 flattened device tree will be copied into upon boot.
5074 For example, if you have a system with 1 GB memory
5075 at physical address 0x10000000, while Linux kernel
5076 only recognizes the first 704 MB as low memory, you
5077 may need to set fdt_high as 0x3C000000 to have the
5078 device tree blob be copied to the maximum address
5079 of the 704 MB low memory, so that Linux kernel can
5080 access it during the boot procedure.
5082 If this is set to the special value 0xFFFFFFFF then
5083 the fdt will not be copied at all on boot. For this
5084 to work it must reside in writable memory, have
5085 sufficient padding on the end of it for u-boot to
5086 add the information it needs into it, and the memory
5087 must be accessible by the kernel.
5089 fdtcontroladdr- if set this is the address of the control flattened
5090 device tree used by U-Boot when CONFIG_OF_CONTROL is
5093 i2cfast - (PPC405GP|PPC405EP only)
5094 if set to 'y' configures Linux I2C driver for fast
5095 mode (400kHZ). This environment variable is used in
5096 initialization code. So, for changes to be effective
5097 it must be saved and board must be reset.
5099 initrd_high - restrict positioning of initrd images:
5100 If this variable is not set, initrd images will be
5101 copied to the highest possible address in RAM; this
5102 is usually what you want since it allows for
5103 maximum initrd size. If for some reason you want to
5104 make sure that the initrd image is loaded below the
5105 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5106 variable to a value of "no" or "off" or "0".
5107 Alternatively, you can set it to a maximum upper
5108 address to use (U-Boot will still check that it
5109 does not overwrite the U-Boot stack and data).
5111 For instance, when you have a system with 16 MB
5112 RAM, and want to reserve 4 MB from use by Linux,
5113 you can do this by adding "mem=12M" to the value of
5114 the "bootargs" variable. However, now you must make
5115 sure that the initrd image is placed in the first
5116 12 MB as well - this can be done with
5118 setenv initrd_high 00c00000
5120 If you set initrd_high to 0xFFFFFFFF, this is an
5121 indication to U-Boot that all addresses are legal
5122 for the Linux kernel, including addresses in flash
5123 memory. In this case U-Boot will NOT COPY the
5124 ramdisk at all. This may be useful to reduce the
5125 boot time on your system, but requires that this
5126 feature is supported by your Linux kernel.
5128 ipaddr - IP address; needed for tftpboot command
5130 loadaddr - Default load address for commands like "bootp",
5131 "rarpboot", "tftpboot", "loadb" or "diskboot"
5133 loads_echo - see CONFIG_LOADS_ECHO
5135 serverip - TFTP server IP address; needed for tftpboot command
5137 bootretry - see CONFIG_BOOT_RETRY_TIME
5139 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5141 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5143 ethprime - controls which interface is used first.
5145 ethact - controls which interface is currently active.
5146 For example you can do the following
5148 => setenv ethact FEC
5149 => ping 192.168.0.1 # traffic sent on FEC
5150 => setenv ethact SCC
5151 => ping 10.0.0.1 # traffic sent on SCC
5153 ethrotate - When set to "no" U-Boot does not go through all
5154 available network interfaces.
5155 It just stays at the currently selected interface.
5157 netretry - When set to "no" each network operation will
5158 either succeed or fail without retrying.
5159 When set to "once" the network operation will
5160 fail when all the available network interfaces
5161 are tried once without success.
5162 Useful on scripts which control the retry operation
5165 npe_ucode - set load address for the NPE microcode
5167 silent_linux - If set then linux will be told to boot silently, by
5168 changing the console to be empty. If "yes" it will be
5169 made silent. If "no" it will not be made silent. If
5170 unset, then it will be made silent if the U-Boot console
5173 tftpsrcport - If this is set, the value is used for TFTP's
5176 tftpdstport - If this is set, the value is used for TFTP's UDP
5177 destination port instead of the Well Know Port 69.
5179 tftpblocksize - Block size to use for TFTP transfers; if not set,
5180 we use the TFTP server's default block size
5182 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5183 seconds, minimum value is 1000 = 1 second). Defines
5184 when a packet is considered to be lost so it has to
5185 be retransmitted. The default is 5000 = 5 seconds.
5186 Lowering this value may make downloads succeed
5187 faster in networks with high packet loss rates or
5188 with unreliable TFTP servers.
5190 vlan - When set to a value < 4095 the traffic over
5191 Ethernet is encapsulated/received over 802.1q
5194 The following image location variables contain the location of images
5195 used in booting. The "Image" column gives the role of the image and is
5196 not an environment variable name. The other columns are environment
5197 variable names. "File Name" gives the name of the file on a TFTP
5198 server, "RAM Address" gives the location in RAM the image will be
5199 loaded to, and "Flash Location" gives the image's address in NOR
5200 flash or offset in NAND flash.
5202 *Note* - these variables don't have to be defined for all boards, some
5203 boards currenlty use other variables for these purposes, and some
5204 boards use these variables for other purposes.
5206 Image File Name RAM Address Flash Location
5207 ----- --------- ----------- --------------
5208 u-boot u-boot u-boot_addr_r u-boot_addr
5209 Linux kernel bootfile kernel_addr_r kernel_addr
5210 device tree blob fdtfile fdt_addr_r fdt_addr
5211 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5213 The following environment variables may be used and automatically
5214 updated by the network boot commands ("bootp" and "rarpboot"),
5215 depending the information provided by your boot server:
5217 bootfile - see above
5218 dnsip - IP address of your Domain Name Server
5219 dnsip2 - IP address of your secondary Domain Name Server
5220 gatewayip - IP address of the Gateway (Router) to use
5221 hostname - Target hostname
5223 netmask - Subnet Mask
5224 rootpath - Pathname of the root filesystem on the NFS server
5225 serverip - see above
5228 There are two special Environment Variables:
5230 serial# - contains hardware identification information such
5231 as type string and/or serial number
5232 ethaddr - Ethernet address
5234 These variables can be set only once (usually during manufacturing of
5235 the board). U-Boot refuses to delete or overwrite these variables
5236 once they have been set once.
5239 Further special Environment Variables:
5241 ver - Contains the U-Boot version string as printed
5242 with the "version" command. This variable is
5243 readonly (see CONFIG_VERSION_VARIABLE).
5246 Please note that changes to some configuration parameters may take
5247 only effect after the next boot (yes, that's just like Windoze :-).
5250 Callback functions for environment variables:
5251 ---------------------------------------------
5253 For some environment variables, the behavior of u-boot needs to change
5254 when their values are changed. This functionailty allows functions to
5255 be associated with arbitrary variables. On creation, overwrite, or
5256 deletion, the callback will provide the opportunity for some side
5257 effect to happen or for the change to be rejected.
5259 The callbacks are named and associated with a function using the
5260 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5262 These callbacks are associated with variables in one of two ways. The
5263 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5264 in the board configuration to a string that defines a list of
5265 associations. The list must be in the following format:
5267 entry = variable_name[:callback_name]
5270 If the callback name is not specified, then the callback is deleted.
5271 Spaces are also allowed anywhere in the list.
5273 Callbacks can also be associated by defining the ".callbacks" variable
5274 with the same list format above. Any association in ".callbacks" will
5275 override any association in the static list. You can define
5276 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5277 ".callbacks" envirnoment variable in the default or embedded environment.
5280 Command Line Parsing:
5281 =====================
5283 There are two different command line parsers available with U-Boot:
5284 the old "simple" one, and the much more powerful "hush" shell:
5286 Old, simple command line parser:
5287 --------------------------------
5289 - supports environment variables (through setenv / saveenv commands)
5290 - several commands on one line, separated by ';'
5291 - variable substitution using "... ${name} ..." syntax
5292 - special characters ('$', ';') can be escaped by prefixing with '\',
5294 setenv bootcmd bootm \${address}
5295 - You can also escape text by enclosing in single apostrophes, for example:
5296 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5301 - similar to Bourne shell, with control structures like
5302 if...then...else...fi, for...do...done; while...do...done,
5303 until...do...done, ...
5304 - supports environment ("global") variables (through setenv / saveenv
5305 commands) and local shell variables (through standard shell syntax
5306 "name=value"); only environment variables can be used with "run"
5312 (1) If a command line (or an environment variable executed by a "run"
5313 command) contains several commands separated by semicolon, and
5314 one of these commands fails, then the remaining commands will be
5317 (2) If you execute several variables with one call to run (i. e.
5318 calling run with a list of variables as arguments), any failing
5319 command will cause "run" to terminate, i. e. the remaining
5320 variables are not executed.
5322 Note for Redundant Ethernet Interfaces:
5323 =======================================
5325 Some boards come with redundant Ethernet interfaces; U-Boot supports
5326 such configurations and is capable of automatic selection of a
5327 "working" interface when needed. MAC assignment works as follows:
5329 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5330 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5331 "eth1addr" (=>eth1), "eth2addr", ...
5333 If the network interface stores some valid MAC address (for instance
5334 in SROM), this is used as default address if there is NO correspon-
5335 ding setting in the environment; if the corresponding environment
5336 variable is set, this overrides the settings in the card; that means:
5338 o If the SROM has a valid MAC address, and there is no address in the
5339 environment, the SROM's address is used.
5341 o If there is no valid address in the SROM, and a definition in the
5342 environment exists, then the value from the environment variable is
5345 o If both the SROM and the environment contain a MAC address, and
5346 both addresses are the same, this MAC address is used.
5348 o If both the SROM and the environment contain a MAC address, and the
5349 addresses differ, the value from the environment is used and a
5352 o If neither SROM nor the environment contain a MAC address, an error
5355 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5356 will be programmed into hardware as part of the initialization process. This
5357 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5358 The naming convention is as follows:
5359 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5364 U-Boot is capable of booting (and performing other auxiliary operations on)
5365 images in two formats:
5367 New uImage format (FIT)
5368 -----------------------
5370 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5371 to Flattened Device Tree). It allows the use of images with multiple
5372 components (several kernels, ramdisks, etc.), with contents protected by
5373 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5379 Old image format is based on binary files which can be basically anything,
5380 preceded by a special header; see the definitions in include/image.h for
5381 details; basically, the header defines the following image properties:
5383 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5384 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5385 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5386 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5388 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5389 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5390 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5391 * Compression Type (uncompressed, gzip, bzip2)
5397 The header is marked by a special Magic Number, and both the header
5398 and the data portions of the image are secured against corruption by
5405 Although U-Boot should support any OS or standalone application
5406 easily, the main focus has always been on Linux during the design of
5409 U-Boot includes many features that so far have been part of some
5410 special "boot loader" code within the Linux kernel. Also, any
5411 "initrd" images to be used are no longer part of one big Linux image;
5412 instead, kernel and "initrd" are separate images. This implementation
5413 serves several purposes:
5415 - the same features can be used for other OS or standalone
5416 applications (for instance: using compressed images to reduce the
5417 Flash memory footprint)
5419 - it becomes much easier to port new Linux kernel versions because
5420 lots of low-level, hardware dependent stuff are done by U-Boot
5422 - the same Linux kernel image can now be used with different "initrd"
5423 images; of course this also means that different kernel images can
5424 be run with the same "initrd". This makes testing easier (you don't
5425 have to build a new "zImage.initrd" Linux image when you just
5426 change a file in your "initrd"). Also, a field-upgrade of the
5427 software is easier now.
5433 Porting Linux to U-Boot based systems:
5434 ---------------------------------------
5436 U-Boot cannot save you from doing all the necessary modifications to
5437 configure the Linux device drivers for use with your target hardware
5438 (no, we don't intend to provide a full virtual machine interface to
5441 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5443 Just make sure your machine specific header file (for instance
5444 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5445 Information structure as we define in include/asm-<arch>/u-boot.h,
5446 and make sure that your definition of IMAP_ADDR uses the same value
5447 as your U-Boot configuration in CONFIG_SYS_IMMR.
5449 Note that U-Boot now has a driver model, a unified model for drivers.
5450 If you are adding a new driver, plumb it into driver model. If there
5451 is no uclass available, you are encouraged to create one. See
5455 Configuring the Linux kernel:
5456 -----------------------------
5458 No specific requirements for U-Boot. Make sure you have some root
5459 device (initial ramdisk, NFS) for your target system.
5462 Building a Linux Image:
5463 -----------------------
5465 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5466 not used. If you use recent kernel source, a new build target
5467 "uImage" will exist which automatically builds an image usable by
5468 U-Boot. Most older kernels also have support for a "pImage" target,
5469 which was introduced for our predecessor project PPCBoot and uses a
5470 100% compatible format.
5479 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5480 encapsulate a compressed Linux kernel image with header information,
5481 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5483 * build a standard "vmlinux" kernel image (in ELF binary format):
5485 * convert the kernel into a raw binary image:
5487 ${CROSS_COMPILE}-objcopy -O binary \
5488 -R .note -R .comment \
5489 -S vmlinux linux.bin
5491 * compress the binary image:
5495 * package compressed binary image for U-Boot:
5497 mkimage -A ppc -O linux -T kernel -C gzip \
5498 -a 0 -e 0 -n "Linux Kernel Image" \
5499 -d linux.bin.gz uImage
5502 The "mkimage" tool can also be used to create ramdisk images for use
5503 with U-Boot, either separated from the Linux kernel image, or
5504 combined into one file. "mkimage" encapsulates the images with a 64
5505 byte header containing information about target architecture,
5506 operating system, image type, compression method, entry points, time
5507 stamp, CRC32 checksums, etc.
5509 "mkimage" can be called in two ways: to verify existing images and
5510 print the header information, or to build new images.
5512 In the first form (with "-l" option) mkimage lists the information
5513 contained in the header of an existing U-Boot image; this includes
5514 checksum verification:
5516 tools/mkimage -l image
5517 -l ==> list image header information
5519 The second form (with "-d" option) is used to build a U-Boot image
5520 from a "data file" which is used as image payload:
5522 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5523 -n name -d data_file image
5524 -A ==> set architecture to 'arch'
5525 -O ==> set operating system to 'os'
5526 -T ==> set image type to 'type'
5527 -C ==> set compression type 'comp'
5528 -a ==> set load address to 'addr' (hex)
5529 -e ==> set entry point to 'ep' (hex)
5530 -n ==> set image name to 'name'
5531 -d ==> use image data from 'datafile'
5533 Right now, all Linux kernels for PowerPC systems use the same load
5534 address (0x00000000), but the entry point address depends on the
5537 - 2.2.x kernels have the entry point at 0x0000000C,
5538 - 2.3.x and later kernels have the entry point at 0x00000000.
5540 So a typical call to build a U-Boot image would read:
5542 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5543 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5544 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5545 > examples/uImage.TQM850L
5546 Image Name: 2.4.4 kernel for TQM850L
5547 Created: Wed Jul 19 02:34:59 2000
5548 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5549 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5550 Load Address: 0x00000000
5551 Entry Point: 0x00000000
5553 To verify the contents of the image (or check for corruption):
5555 -> tools/mkimage -l examples/uImage.TQM850L
5556 Image Name: 2.4.4 kernel for TQM850L
5557 Created: Wed Jul 19 02:34:59 2000
5558 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5559 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5560 Load Address: 0x00000000
5561 Entry Point: 0x00000000
5563 NOTE: for embedded systems where boot time is critical you can trade
5564 speed for memory and install an UNCOMPRESSED image instead: this
5565 needs more space in Flash, but boots much faster since it does not
5566 need to be uncompressed:
5568 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5569 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5570 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5571 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5572 > examples/uImage.TQM850L-uncompressed
5573 Image Name: 2.4.4 kernel for TQM850L
5574 Created: Wed Jul 19 02:34:59 2000
5575 Image Type: PowerPC Linux Kernel Image (uncompressed)
5576 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5577 Load Address: 0x00000000
5578 Entry Point: 0x00000000
5581 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5582 when your kernel is intended to use an initial ramdisk:
5584 -> tools/mkimage -n 'Simple Ramdisk Image' \
5585 > -A ppc -O linux -T ramdisk -C gzip \
5586 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5587 Image Name: Simple Ramdisk Image
5588 Created: Wed Jan 12 14:01:50 2000
5589 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5590 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5591 Load Address: 0x00000000
5592 Entry Point: 0x00000000
5594 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5595 option performs the converse operation of the mkimage's second form (the "-d"
5596 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5599 tools/dumpimage -i image -p position data_file
5600 -i ==> extract from the 'image' a specific 'data_file', \
5601 indexed by 'position'
5604 Installing a Linux Image:
5605 -------------------------
5607 To downloading a U-Boot image over the serial (console) interface,
5608 you must convert the image to S-Record format:
5610 objcopy -I binary -O srec examples/image examples/image.srec
5612 The 'objcopy' does not understand the information in the U-Boot
5613 image header, so the resulting S-Record file will be relative to
5614 address 0x00000000. To load it to a given address, you need to
5615 specify the target address as 'offset' parameter with the 'loads'
5618 Example: install the image to address 0x40100000 (which on the
5619 TQM8xxL is in the first Flash bank):
5621 => erase 40100000 401FFFFF
5627 ## Ready for S-Record download ...
5628 ~>examples/image.srec
5629 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5631 15989 15990 15991 15992
5632 [file transfer complete]
5634 ## Start Addr = 0x00000000
5637 You can check the success of the download using the 'iminfo' command;
5638 this includes a checksum verification so you can be sure no data
5639 corruption happened:
5643 ## Checking Image at 40100000 ...
5644 Image Name: 2.2.13 for initrd on TQM850L
5645 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5646 Data Size: 335725 Bytes = 327 kB = 0 MB
5647 Load Address: 00000000
5648 Entry Point: 0000000c
5649 Verifying Checksum ... OK
5655 The "bootm" command is used to boot an application that is stored in
5656 memory (RAM or Flash). In case of a Linux kernel image, the contents
5657 of the "bootargs" environment variable is passed to the kernel as
5658 parameters. You can check and modify this variable using the
5659 "printenv" and "setenv" commands:
5662 => printenv bootargs
5663 bootargs=root=/dev/ram
5665 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5667 => printenv bootargs
5668 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5671 ## Booting Linux kernel at 40020000 ...
5672 Image Name: 2.2.13 for NFS on TQM850L
5673 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5674 Data Size: 381681 Bytes = 372 kB = 0 MB
5675 Load Address: 00000000
5676 Entry Point: 0000000c
5677 Verifying Checksum ... OK
5678 Uncompressing Kernel Image ... OK
5679 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
5680 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5681 time_init: decrementer frequency = 187500000/60
5682 Calibrating delay loop... 49.77 BogoMIPS
5683 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5686 If you want to boot a Linux kernel with initial RAM disk, you pass
5687 the memory addresses of both the kernel and the initrd image (PPBCOOT
5688 format!) to the "bootm" command:
5690 => imi 40100000 40200000
5692 ## Checking Image at 40100000 ...
5693 Image Name: 2.2.13 for initrd on TQM850L
5694 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5695 Data Size: 335725 Bytes = 327 kB = 0 MB
5696 Load Address: 00000000
5697 Entry Point: 0000000c
5698 Verifying Checksum ... OK
5700 ## Checking Image at 40200000 ...
5701 Image Name: Simple Ramdisk Image
5702 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5703 Data Size: 566530 Bytes = 553 kB = 0 MB
5704 Load Address: 00000000
5705 Entry Point: 00000000
5706 Verifying Checksum ... OK
5708 => bootm 40100000 40200000
5709 ## Booting Linux kernel at 40100000 ...
5710 Image Name: 2.2.13 for initrd on TQM850L
5711 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5712 Data Size: 335725 Bytes = 327 kB = 0 MB
5713 Load Address: 00000000
5714 Entry Point: 0000000c
5715 Verifying Checksum ... OK
5716 Uncompressing Kernel Image ... OK
5717 ## Loading RAMDisk Image at 40200000 ...
5718 Image Name: Simple Ramdisk Image
5719 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5720 Data Size: 566530 Bytes = 553 kB = 0 MB
5721 Load Address: 00000000
5722 Entry Point: 00000000
5723 Verifying Checksum ... OK
5724 Loading Ramdisk ... OK
5725 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
5726 Boot arguments: root=/dev/ram
5727 time_init: decrementer frequency = 187500000/60
5728 Calibrating delay loop... 49.77 BogoMIPS
5730 RAMDISK: Compressed image found at block 0
5731 VFS: Mounted root (ext2 filesystem).
5735 Boot Linux and pass a flat device tree:
5738 First, U-Boot must be compiled with the appropriate defines. See the section
5739 titled "Linux Kernel Interface" above for a more in depth explanation. The
5740 following is an example of how to start a kernel and pass an updated
5746 oft=oftrees/mpc8540ads.dtb
5747 => tftp $oftaddr $oft
5748 Speed: 1000, full duplex
5750 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5751 Filename 'oftrees/mpc8540ads.dtb'.
5752 Load address: 0x300000
5755 Bytes transferred = 4106 (100a hex)
5756 => tftp $loadaddr $bootfile
5757 Speed: 1000, full duplex
5759 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5761 Load address: 0x200000
5762 Loading:############
5764 Bytes transferred = 1029407 (fb51f hex)
5769 => bootm $loadaddr - $oftaddr
5770 ## Booting image at 00200000 ...
5771 Image Name: Linux-2.6.17-dirty
5772 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5773 Data Size: 1029343 Bytes = 1005.2 kB
5774 Load Address: 00000000
5775 Entry Point: 00000000
5776 Verifying Checksum ... OK
5777 Uncompressing Kernel Image ... OK
5778 Booting using flat device tree at 0x300000
5779 Using MPC85xx ADS machine description
5780 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5784 More About U-Boot Image Types:
5785 ------------------------------
5787 U-Boot supports the following image types:
5789 "Standalone Programs" are directly runnable in the environment
5790 provided by U-Boot; it is expected that (if they behave
5791 well) you can continue to work in U-Boot after return from
5792 the Standalone Program.
5793 "OS Kernel Images" are usually images of some Embedded OS which
5794 will take over control completely. Usually these programs
5795 will install their own set of exception handlers, device
5796 drivers, set up the MMU, etc. - this means, that you cannot
5797 expect to re-enter U-Boot except by resetting the CPU.
5798 "RAMDisk Images" are more or less just data blocks, and their
5799 parameters (address, size) are passed to an OS kernel that is
5801 "Multi-File Images" contain several images, typically an OS
5802 (Linux) kernel image and one or more data images like
5803 RAMDisks. This construct is useful for instance when you want
5804 to boot over the network using BOOTP etc., where the boot
5805 server provides just a single image file, but you want to get
5806 for instance an OS kernel and a RAMDisk image.
5808 "Multi-File Images" start with a list of image sizes, each
5809 image size (in bytes) specified by an "uint32_t" in network
5810 byte order. This list is terminated by an "(uint32_t)0".
5811 Immediately after the terminating 0 follow the images, one by
5812 one, all aligned on "uint32_t" boundaries (size rounded up to
5813 a multiple of 4 bytes).
5815 "Firmware Images" are binary images containing firmware (like
5816 U-Boot or FPGA images) which usually will be programmed to
5819 "Script files" are command sequences that will be executed by
5820 U-Boot's command interpreter; this feature is especially
5821 useful when you configure U-Boot to use a real shell (hush)
5822 as command interpreter.
5824 Booting the Linux zImage:
5825 -------------------------
5827 On some platforms, it's possible to boot Linux zImage. This is done
5828 using the "bootz" command. The syntax of "bootz" command is the same
5829 as the syntax of "bootm" command.
5831 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5832 kernel with raw initrd images. The syntax is slightly different, the
5833 address of the initrd must be augmented by it's size, in the following
5834 format: "<initrd addres>:<initrd size>".
5840 One of the features of U-Boot is that you can dynamically load and
5841 run "standalone" applications, which can use some resources of
5842 U-Boot like console I/O functions or interrupt services.
5844 Two simple examples are included with the sources:
5849 'examples/hello_world.c' contains a small "Hello World" Demo
5850 application; it is automatically compiled when you build U-Boot.
5851 It's configured to run at address 0x00040004, so you can play with it
5855 ## Ready for S-Record download ...
5856 ~>examples/hello_world.srec
5857 1 2 3 4 5 6 7 8 9 10 11 ...
5858 [file transfer complete]
5860 ## Start Addr = 0x00040004
5862 => go 40004 Hello World! This is a test.
5863 ## Starting application at 0x00040004 ...
5874 Hit any key to exit ...
5876 ## Application terminated, rc = 0x0
5878 Another example, which demonstrates how to register a CPM interrupt
5879 handler with the U-Boot code, can be found in 'examples/timer.c'.
5880 Here, a CPM timer is set up to generate an interrupt every second.
5881 The interrupt service routine is trivial, just printing a '.'
5882 character, but this is just a demo program. The application can be
5883 controlled by the following keys:
5885 ? - print current values og the CPM Timer registers
5886 b - enable interrupts and start timer
5887 e - stop timer and disable interrupts
5888 q - quit application
5891 ## Ready for S-Record download ...
5892 ~>examples/timer.srec
5893 1 2 3 4 5 6 7 8 9 10 11 ...
5894 [file transfer complete]
5896 ## Start Addr = 0x00040004
5899 ## Starting application at 0x00040004 ...
5902 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5905 [q, b, e, ?] Set interval 1000000 us
5908 [q, b, e, ?] ........
5909 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5912 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5915 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5918 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5920 [q, b, e, ?] ...Stopping timer
5922 [q, b, e, ?] ## Application terminated, rc = 0x0
5928 Over time, many people have reported problems when trying to use the
5929 "minicom" terminal emulation program for serial download. I (wd)
5930 consider minicom to be broken, and recommend not to use it. Under
5931 Unix, I recommend to use C-Kermit for general purpose use (and
5932 especially for kermit binary protocol download ("loadb" command), and
5933 use "cu" for S-Record download ("loads" command). See
5934 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5935 for help with kermit.
5938 Nevertheless, if you absolutely want to use it try adding this
5939 configuration to your "File transfer protocols" section:
5941 Name Program Name U/D FullScr IO-Red. Multi
5942 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5943 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5949 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5950 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5952 Building requires a cross environment; it is known to work on
5953 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5954 need gmake since the Makefiles are not compatible with BSD make).
5955 Note that the cross-powerpc package does not install include files;
5956 attempting to build U-Boot will fail because <machine/ansi.h> is
5957 missing. This file has to be installed and patched manually:
5959 # cd /usr/pkg/cross/powerpc-netbsd/include
5961 # ln -s powerpc machine
5962 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5963 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5965 Native builds *don't* work due to incompatibilities between native
5966 and U-Boot include files.
5968 Booting assumes that (the first part of) the image booted is a
5969 stage-2 loader which in turn loads and then invokes the kernel
5970 proper. Loader sources will eventually appear in the NetBSD source
5971 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5972 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5975 Implementation Internals:
5976 =========================
5978 The following is not intended to be a complete description of every
5979 implementation detail. However, it should help to understand the
5980 inner workings of U-Boot and make it easier to port it to custom
5984 Initial Stack, Global Data:
5985 ---------------------------
5987 The implementation of U-Boot is complicated by the fact that U-Boot
5988 starts running out of ROM (flash memory), usually without access to
5989 system RAM (because the memory controller is not initialized yet).
5990 This means that we don't have writable Data or BSS segments, and BSS
5991 is not initialized as zero. To be able to get a C environment working
5992 at all, we have to allocate at least a minimal stack. Implementation
5993 options for this are defined and restricted by the CPU used: Some CPU
5994 models provide on-chip memory (like the IMMR area on MPC8xx and
5995 MPC826x processors), on others (parts of) the data cache can be
5996 locked as (mis-) used as memory, etc.
5998 Chris Hallinan posted a good summary of these issues to the
5999 U-Boot mailing list:
6001 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6002 From: "Chris Hallinan" <clh@net1plus.com>
6003 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6006 Correct me if I'm wrong, folks, but the way I understand it
6007 is this: Using DCACHE as initial RAM for Stack, etc, does not
6008 require any physical RAM backing up the cache. The cleverness
6009 is that the cache is being used as a temporary supply of
6010 necessary storage before the SDRAM controller is setup. It's
6011 beyond the scope of this list to explain the details, but you
6012 can see how this works by studying the cache architecture and
6013 operation in the architecture and processor-specific manuals.
6015 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6016 is another option for the system designer to use as an
6017 initial stack/RAM area prior to SDRAM being available. Either
6018 option should work for you. Using CS 4 should be fine if your
6019 board designers haven't used it for something that would
6020 cause you grief during the initial boot! It is frequently not
6023 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6024 with your processor/board/system design. The default value
6025 you will find in any recent u-boot distribution in
6026 walnut.h should work for you. I'd set it to a value larger
6027 than your SDRAM module. If you have a 64MB SDRAM module, set
6028 it above 400_0000. Just make sure your board has no resources
6029 that are supposed to respond to that address! That code in
6030 start.S has been around a while and should work as is when
6031 you get the config right.
6036 It is essential to remember this, since it has some impact on the C
6037 code for the initialization procedures:
6039 * Initialized global data (data segment) is read-only. Do not attempt
6042 * Do not use any uninitialized global data (or implicitely initialized
6043 as zero data - BSS segment) at all - this is undefined, initiali-
6044 zation is performed later (when relocating to RAM).
6046 * Stack space is very limited. Avoid big data buffers or things like
6049 Having only the stack as writable memory limits means we cannot use
6050 normal global data to share information beween the code. But it
6051 turned out that the implementation of U-Boot can be greatly
6052 simplified by making a global data structure (gd_t) available to all
6053 functions. We could pass a pointer to this data as argument to _all_
6054 functions, but this would bloat the code. Instead we use a feature of
6055 the GCC compiler (Global Register Variables) to share the data: we
6056 place a pointer (gd) to the global data into a register which we
6057 reserve for this purpose.
6059 When choosing a register for such a purpose we are restricted by the
6060 relevant (E)ABI specifications for the current architecture, and by
6061 GCC's implementation.
6063 For PowerPC, the following registers have specific use:
6065 R2: reserved for system use
6066 R3-R4: parameter passing and return values
6067 R5-R10: parameter passing
6068 R13: small data area pointer
6072 (U-Boot also uses R12 as internal GOT pointer. r12
6073 is a volatile register so r12 needs to be reset when
6074 going back and forth between asm and C)
6076 ==> U-Boot will use R2 to hold a pointer to the global data
6078 Note: on PPC, we could use a static initializer (since the
6079 address of the global data structure is known at compile time),
6080 but it turned out that reserving a register results in somewhat
6081 smaller code - although the code savings are not that big (on
6082 average for all boards 752 bytes for the whole U-Boot image,
6083 624 text + 127 data).
6085 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6086 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6088 ==> U-Boot will use P3 to hold a pointer to the global data
6090 On ARM, the following registers are used:
6092 R0: function argument word/integer result
6093 R1-R3: function argument word
6094 R9: platform specific
6095 R10: stack limit (used only if stack checking is enabled)
6096 R11: argument (frame) pointer
6097 R12: temporary workspace
6100 R15: program counter
6102 ==> U-Boot will use R9 to hold a pointer to the global data
6104 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6106 On Nios II, the ABI is documented here:
6107 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6109 ==> U-Boot will use gp to hold a pointer to the global data
6111 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6112 to access small data sections, so gp is free.
6114 On NDS32, the following registers are used:
6116 R0-R1: argument/return
6118 R15: temporary register for assembler
6119 R16: trampoline register
6120 R28: frame pointer (FP)
6121 R29: global pointer (GP)
6122 R30: link register (LP)
6123 R31: stack pointer (SP)
6124 PC: program counter (PC)
6126 ==> U-Boot will use R10 to hold a pointer to the global data
6128 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6129 or current versions of GCC may "optimize" the code too much.
6134 U-Boot runs in system state and uses physical addresses, i.e. the
6135 MMU is not used either for address mapping nor for memory protection.
6137 The available memory is mapped to fixed addresses using the memory
6138 controller. In this process, a contiguous block is formed for each
6139 memory type (Flash, SDRAM, SRAM), even when it consists of several
6140 physical memory banks.
6142 U-Boot is installed in the first 128 kB of the first Flash bank (on
6143 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6144 booting and sizing and initializing DRAM, the code relocates itself
6145 to the upper end of DRAM. Immediately below the U-Boot code some
6146 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6147 configuration setting]. Below that, a structure with global Board
6148 Info data is placed, followed by the stack (growing downward).
6150 Additionally, some exception handler code is copied to the low 8 kB
6151 of DRAM (0x00000000 ... 0x00001FFF).
6153 So a typical memory configuration with 16 MB of DRAM could look like
6156 0x0000 0000 Exception Vector code
6159 0x0000 2000 Free for Application Use
6165 0x00FB FF20 Monitor Stack (Growing downward)
6166 0x00FB FFAC Board Info Data and permanent copy of global data
6167 0x00FC 0000 Malloc Arena
6170 0x00FE 0000 RAM Copy of Monitor Code
6171 ... eventually: LCD or video framebuffer
6172 ... eventually: pRAM (Protected RAM - unchanged by reset)
6173 0x00FF FFFF [End of RAM]
6176 System Initialization:
6177 ----------------------
6179 In the reset configuration, U-Boot starts at the reset entry point
6180 (on most PowerPC systems at address 0x00000100). Because of the reset
6181 configuration for CS0# this is a mirror of the onboard Flash memory.
6182 To be able to re-map memory U-Boot then jumps to its link address.
6183 To be able to implement the initialization code in C, a (small!)
6184 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6185 which provide such a feature like MPC8xx or MPC8260), or in a locked
6186 part of the data cache. After that, U-Boot initializes the CPU core,
6187 the caches and the SIU.
6189 Next, all (potentially) available memory banks are mapped using a
6190 preliminary mapping. For example, we put them on 512 MB boundaries
6191 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6192 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6193 programmed for SDRAM access. Using the temporary configuration, a
6194 simple memory test is run that determines the size of the SDRAM
6197 When there is more than one SDRAM bank, and the banks are of
6198 different size, the largest is mapped first. For equal size, the first
6199 bank (CS2#) is mapped first. The first mapping is always for address
6200 0x00000000, with any additional banks following immediately to create
6201 contiguous memory starting from 0.
6203 Then, the monitor installs itself at the upper end of the SDRAM area
6204 and allocates memory for use by malloc() and for the global Board
6205 Info data; also, the exception vector code is copied to the low RAM
6206 pages, and the final stack is set up.
6208 Only after this relocation will you have a "normal" C environment;
6209 until that you are restricted in several ways, mostly because you are
6210 running from ROM, and because the code will have to be relocated to a
6214 U-Boot Porting Guide:
6215 ----------------------
6217 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6221 int main(int argc, char *argv[])
6223 sighandler_t no_more_time;
6225 signal(SIGALRM, no_more_time);
6226 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6228 if (available_money > available_manpower) {
6229 Pay consultant to port U-Boot;
6233 Download latest U-Boot source;
6235 Subscribe to u-boot mailing list;
6238 email("Hi, I am new to U-Boot, how do I get started?");
6241 Read the README file in the top level directory;
6242 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6243 Read applicable doc/*.README;
6244 Read the source, Luke;
6245 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6248 if (available_money > toLocalCurrency ($2500))
6251 Add a lot of aggravation and time;
6253 if (a similar board exists) { /* hopefully... */
6254 cp -a board/<similar> board/<myboard>
6255 cp include/configs/<similar>.h include/configs/<myboard>.h
6257 Create your own board support subdirectory;
6258 Create your own board include/configs/<myboard>.h file;
6260 Edit new board/<myboard> files
6261 Edit new include/configs/<myboard>.h
6266 Add / modify source code;
6270 email("Hi, I am having problems...");
6272 Send patch file to the U-Boot email list;
6273 if (reasonable critiques)
6274 Incorporate improvements from email list code review;
6276 Defend code as written;
6282 void no_more_time (int sig)
6291 All contributions to U-Boot should conform to the Linux kernel
6292 coding style; see the file "Documentation/CodingStyle" and the script
6293 "scripts/Lindent" in your Linux kernel source directory.
6295 Source files originating from a different project (for example the
6296 MTD subsystem) are generally exempt from these guidelines and are not
6297 reformated to ease subsequent migration to newer versions of those
6300 Please note that U-Boot is implemented in C (and to some small parts in
6301 Assembler); no C++ is used, so please do not use C++ style comments (//)
6304 Please also stick to the following formatting rules:
6305 - remove any trailing white space
6306 - use TAB characters for indentation and vertical alignment, not spaces
6307 - make sure NOT to use DOS '\r\n' line feeds
6308 - do not add more than 2 consecutive empty lines to source files
6309 - do not add trailing empty lines to source files
6311 Submissions which do not conform to the standards may be returned
6312 with a request to reformat the changes.
6318 Since the number of patches for U-Boot is growing, we need to
6319 establish some rules. Submissions which do not conform to these rules
6320 may be rejected, even when they contain important and valuable stuff.
6322 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6324 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6325 see http://lists.denx.de/mailman/listinfo/u-boot
6327 When you send a patch, please include the following information with
6330 * For bug fixes: a description of the bug and how your patch fixes
6331 this bug. Please try to include a way of demonstrating that the
6332 patch actually fixes something.
6334 * For new features: a description of the feature and your
6337 * A CHANGELOG entry as plaintext (separate from the patch)
6339 * For major contributions, your entry to the CREDITS file
6341 * When you add support for a new board, don't forget to add a
6342 maintainer e-mail address to the boards.cfg file, too.
6344 * If your patch adds new configuration options, don't forget to
6345 document these in the README file.
6347 * The patch itself. If you are using git (which is *strongly*
6348 recommended) you can easily generate the patch using the
6349 "git format-patch". If you then use "git send-email" to send it to
6350 the U-Boot mailing list, you will avoid most of the common problems
6351 with some other mail clients.
6353 If you cannot use git, use "diff -purN OLD NEW". If your version of
6354 diff does not support these options, then get the latest version of
6357 The current directory when running this command shall be the parent
6358 directory of the U-Boot source tree (i. e. please make sure that
6359 your patch includes sufficient directory information for the
6362 We prefer patches as plain text. MIME attachments are discouraged,
6363 and compressed attachments must not be used.
6365 * If one logical set of modifications affects or creates several
6366 files, all these changes shall be submitted in a SINGLE patch file.
6368 * Changesets that contain different, unrelated modifications shall be
6369 submitted as SEPARATE patches, one patch per changeset.
6374 * Before sending the patch, run the MAKEALL script on your patched
6375 source tree and make sure that no errors or warnings are reported
6376 for any of the boards.
6378 * Keep your modifications to the necessary minimum: A patch
6379 containing several unrelated changes or arbitrary reformats will be
6380 returned with a request to re-formatting / split it.
6382 * If you modify existing code, make sure that your new code does not
6383 add to the memory footprint of the code ;-) Small is beautiful!
6384 When adding new features, these should compile conditionally only
6385 (using #ifdef), and the resulting code with the new feature
6386 disabled must not need more memory than the old code without your
6389 * Remember that there is a size limit of 100 kB per message on the
6390 u-boot mailing list. Bigger patches will be moderated. If they are
6391 reasonable and not too big, they will be acknowledged. But patches
6392 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob