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 for PWM modul on the imx6.
1386 Support TPM devices.
1389 Support for i2c bus TPM devices. Only one device
1390 per system is supported at this time.
1392 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1393 Define the the i2c bus number for the TPM device
1395 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1396 Define the TPM's address on the i2c bus
1398 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1399 Define the burst count bytes upper limit
1401 CONFIG_TPM_ATMEL_TWI
1402 Support for Atmel TWI TPM device. Requires I2C support.
1405 Support for generic parallel port TPM devices. Only one device
1406 per system is supported at this time.
1408 CONFIG_TPM_TIS_BASE_ADDRESS
1409 Base address where the generic TPM device is mapped
1410 to. Contemporary x86 systems usually map it at
1414 Add tpm monitor functions.
1415 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1416 provides monitor access to authorized functions.
1419 Define this to enable the TPM support library which provides
1420 functional interfaces to some TPM commands.
1421 Requires support for a TPM device.
1423 CONFIG_TPM_AUTH_SESSIONS
1424 Define this to enable authorized functions in the TPM library.
1425 Requires CONFIG_TPM and CONFIG_SHA1.
1428 At the moment only the UHCI host controller is
1429 supported (PIP405, MIP405, MPC5200); define
1430 CONFIG_USB_UHCI to enable it.
1431 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1432 and define CONFIG_USB_STORAGE to enable the USB
1435 Supported are USB Keyboards and USB Floppy drives
1437 MPC5200 USB requires additional defines:
1439 for 528 MHz Clock: 0x0001bbbb
1443 for differential drivers: 0x00001000
1444 for single ended drivers: 0x00005000
1445 for differential drivers on PSC3: 0x00000100
1446 for single ended drivers on PSC3: 0x00004100
1447 CONFIG_SYS_USB_EVENT_POLL
1448 May be defined to allow interrupt polling
1449 instead of using asynchronous interrupts
1451 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1452 txfilltuning field in the EHCI controller on reset.
1455 Define the below if you wish to use the USB console.
1456 Once firmware is rebuilt from a serial console issue the
1457 command "setenv stdin usbtty; setenv stdout usbtty" and
1458 attach your USB cable. The Unix command "dmesg" should print
1459 it has found a new device. The environment variable usbtty
1460 can be set to gserial or cdc_acm to enable your device to
1461 appear to a USB host as a Linux gserial device or a
1462 Common Device Class Abstract Control Model serial device.
1463 If you select usbtty = gserial you should be able to enumerate
1465 # modprobe usbserial vendor=0xVendorID product=0xProductID
1466 else if using cdc_acm, simply setting the environment
1467 variable usbtty to be cdc_acm should suffice. The following
1468 might be defined in YourBoardName.h
1471 Define this to build a UDC device
1474 Define this to have a tty type of device available to
1475 talk to the UDC device
1478 Define this to enable the high speed support for usb
1479 device and usbtty. If this feature is enabled, a routine
1480 int is_usbd_high_speed(void)
1481 also needs to be defined by the driver to dynamically poll
1482 whether the enumeration has succeded at high speed or full
1485 CONFIG_SYS_CONSOLE_IS_IN_ENV
1486 Define this if you want stdin, stdout &/or stderr to
1490 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1491 Derive USB clock from external clock "blah"
1492 - CONFIG_SYS_USB_EXTC_CLK 0x02
1494 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1495 Derive USB clock from brgclk
1496 - CONFIG_SYS_USB_BRG_CLK 0x04
1498 If you have a USB-IF assigned VendorID then you may wish to
1499 define your own vendor specific values either in BoardName.h
1500 or directly in usbd_vendor_info.h. If you don't define
1501 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1502 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1503 should pretend to be a Linux device to it's target host.
1505 CONFIG_USBD_MANUFACTURER
1506 Define this string as the name of your company for
1507 - CONFIG_USBD_MANUFACTURER "my company"
1509 CONFIG_USBD_PRODUCT_NAME
1510 Define this string as the name of your product
1511 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1513 CONFIG_USBD_VENDORID
1514 Define this as your assigned Vendor ID from the USB
1515 Implementors Forum. This *must* be a genuine Vendor ID
1516 to avoid polluting the USB namespace.
1517 - CONFIG_USBD_VENDORID 0xFFFF
1519 CONFIG_USBD_PRODUCTID
1520 Define this as the unique Product ID
1522 - CONFIG_USBD_PRODUCTID 0xFFFF
1524 - ULPI Layer Support:
1525 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1526 the generic ULPI layer. The generic layer accesses the ULPI PHY
1527 via the platform viewport, so you need both the genric layer and
1528 the viewport enabled. Currently only Chipidea/ARC based
1529 viewport is supported.
1530 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1531 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1532 If your ULPI phy needs a different reference clock than the
1533 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1534 the appropriate value in Hz.
1537 The MMC controller on the Intel PXA is supported. To
1538 enable this define CONFIG_MMC. The MMC can be
1539 accessed from the boot prompt by mapping the device
1540 to physical memory similar to flash. Command line is
1541 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1542 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1545 Support for Renesas on-chip MMCIF controller
1547 CONFIG_SH_MMCIF_ADDR
1548 Define the base address of MMCIF registers
1551 Define the clock frequency for MMCIF
1554 Enable the generic MMC driver
1556 CONFIG_SUPPORT_EMMC_BOOT
1557 Enable some additional features of the eMMC boot partitions.
1559 CONFIG_SUPPORT_EMMC_RPMB
1560 Enable the commands for reading, writing and programming the
1561 key for the Replay Protection Memory Block partition in eMMC.
1563 - USB Device Firmware Update (DFU) class support:
1565 This enables the USB portion of the DFU USB class
1568 This enables the command "dfu" which is used to have
1569 U-Boot create a DFU class device via USB. This command
1570 requires that the "dfu_alt_info" environment variable be
1571 set and define the alt settings to expose to the host.
1574 This enables support for exposing (e)MMC devices via DFU.
1577 This enables support for exposing NAND devices via DFU.
1580 This enables support for exposing RAM via DFU.
1581 Note: DFU spec refer to non-volatile memory usage, but
1582 allow usages beyond the scope of spec - here RAM usage,
1583 one that would help mostly the developer.
1585 CONFIG_SYS_DFU_DATA_BUF_SIZE
1586 Dfu transfer uses a buffer before writing data to the
1587 raw storage device. Make the size (in bytes) of this buffer
1588 configurable. The size of this buffer is also configurable
1589 through the "dfu_bufsiz" environment variable.
1591 CONFIG_SYS_DFU_MAX_FILE_SIZE
1592 When updating files rather than the raw storage device,
1593 we use a static buffer to copy the file into and then write
1594 the buffer once we've been given the whole file. Define
1595 this to the maximum filesize (in bytes) for the buffer.
1596 Default is 4 MiB if undefined.
1598 DFU_DEFAULT_POLL_TIMEOUT
1599 Poll timeout [ms], is the timeout a device can send to the
1600 host. The host must wait for this timeout before sending
1601 a subsequent DFU_GET_STATUS request to the device.
1603 DFU_MANIFEST_POLL_TIMEOUT
1604 Poll timeout [ms], which the device sends to the host when
1605 entering dfuMANIFEST state. Host waits this timeout, before
1606 sending again an USB request to the device.
1608 - USB Device Android Fastboot support:
1610 This enables the command "fastboot" which enables the Android
1611 fastboot mode for the platform's USB device. Fastboot is a USB
1612 protocol for downloading images, flashing and device control
1613 used on Android devices.
1614 See doc/README.android-fastboot for more information.
1616 CONFIG_ANDROID_BOOT_IMAGE
1617 This enables support for booting images which use the Android
1618 image format header.
1620 CONFIG_USB_FASTBOOT_BUF_ADDR
1621 The fastboot protocol requires a large memory buffer for
1622 downloads. Define this to the starting RAM address to use for
1625 CONFIG_USB_FASTBOOT_BUF_SIZE
1626 The fastboot protocol requires a large memory buffer for
1627 downloads. This buffer should be as large as possible for a
1628 platform. Define this to the size available RAM for fastboot.
1630 - Journaling Flash filesystem support:
1631 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1632 CONFIG_JFFS2_NAND_DEV
1633 Define these for a default partition on a NAND device
1635 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1636 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1637 Define these for a default partition on a NOR device
1639 CONFIG_SYS_JFFS_CUSTOM_PART
1640 Define this to create an own partition. You have to provide a
1641 function struct part_info* jffs2_part_info(int part_num)
1643 If you define only one JFFS2 partition you may also want to
1644 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1645 to disable the command chpart. This is the default when you
1646 have not defined a custom partition
1648 - FAT(File Allocation Table) filesystem write function support:
1651 Define this to enable support for saving memory data as a
1652 file in FAT formatted partition.
1654 This will also enable the command "fatwrite" enabling the
1655 user to write files to FAT.
1657 CBFS (Coreboot Filesystem) support
1660 Define this to enable support for reading from a Coreboot
1661 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1664 - FAT(File Allocation Table) filesystem cluster size:
1665 CONFIG_FS_FAT_MAX_CLUSTSIZE
1667 Define the max cluster size for fat operations else
1668 a default value of 65536 will be defined.
1673 Define this to enable standard (PC-Style) keyboard
1677 Standard PC keyboard driver with US (is default) and
1678 GERMAN key layout (switch via environment 'keymap=de') support.
1679 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1680 for cfb_console. Supports cursor blinking.
1683 Enables a Chrome OS keyboard using the CROS_EC interface.
1684 This uses CROS_EC to communicate with a second microcontroller
1685 which provides key scans on request.
1690 Define this to enable video support (for output to
1693 CONFIG_VIDEO_CT69000
1695 Enable Chips & Technologies 69000 Video chip
1697 CONFIG_VIDEO_SMI_LYNXEM
1698 Enable Silicon Motion SMI 712/710/810 Video chip. The
1699 video output is selected via environment 'videoout'
1700 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1703 For the CT69000 and SMI_LYNXEM drivers, videomode is
1704 selected via environment 'videomode'. Two different ways
1706 - "videomode=num" 'num' is a standard LiLo mode numbers.
1707 Following standard modes are supported (* is default):
1709 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1710 -------------+---------------------------------------------
1711 8 bits | 0x301* 0x303 0x305 0x161 0x307
1712 15 bits | 0x310 0x313 0x316 0x162 0x319
1713 16 bits | 0x311 0x314 0x317 0x163 0x31A
1714 24 bits | 0x312 0x315 0x318 ? 0x31B
1715 -------------+---------------------------------------------
1716 (i.e. setenv videomode 317; saveenv; reset;)
1718 - "videomode=bootargs" all the video parameters are parsed
1719 from the bootargs. (See drivers/video/videomodes.c)
1722 CONFIG_VIDEO_SED13806
1723 Enable Epson SED13806 driver. This driver supports 8bpp
1724 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1725 or CONFIG_VIDEO_SED13806_16BPP
1728 Enable the Freescale DIU video driver. Reference boards for
1729 SOCs that have a DIU should define this macro to enable DIU
1730 support, and should also define these other macros:
1736 CONFIG_VIDEO_SW_CURSOR
1737 CONFIG_VGA_AS_SINGLE_DEVICE
1739 CONFIG_VIDEO_BMP_LOGO
1741 The DIU driver will look for the 'video-mode' environment
1742 variable, and if defined, enable the DIU as a console during
1743 boot. See the documentation file README.video for a
1744 description of this variable.
1748 Enable the VGA video / BIOS for x86. The alternative if you
1749 are using coreboot is to use the coreboot frame buffer
1756 Define this to enable a custom keyboard support.
1757 This simply calls drv_keyboard_init() which must be
1758 defined in your board-specific files.
1759 The only board using this so far is RBC823.
1761 - LCD Support: CONFIG_LCD
1763 Define this to enable LCD support (for output to LCD
1764 display); also select one of the supported displays
1765 by defining one of these:
1769 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1771 CONFIG_NEC_NL6448AC33:
1773 NEC NL6448AC33-18. Active, color, single scan.
1775 CONFIG_NEC_NL6448BC20
1777 NEC NL6448BC20-08. 6.5", 640x480.
1778 Active, color, single scan.
1780 CONFIG_NEC_NL6448BC33_54
1782 NEC NL6448BC33-54. 10.4", 640x480.
1783 Active, color, single scan.
1787 Sharp 320x240. Active, color, single scan.
1788 It isn't 16x9, and I am not sure what it is.
1790 CONFIG_SHARP_LQ64D341
1792 Sharp LQ64D341 display, 640x480.
1793 Active, color, single scan.
1797 HLD1045 display, 640x480.
1798 Active, color, single scan.
1802 Optrex CBL50840-2 NF-FW 99 22 M5
1804 Hitachi LMG6912RPFC-00T
1808 320x240. Black & white.
1810 Normally display is black on white background; define
1811 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1813 CONFIG_LCD_ALIGNMENT
1815 Normally the LCD is page-aligned (tyically 4KB). If this is
1816 defined then the LCD will be aligned to this value instead.
1817 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1818 here, since it is cheaper to change data cache settings on
1819 a per-section basis.
1821 CONFIG_CONSOLE_SCROLL_LINES
1823 When the console need to be scrolled, this is the number of
1824 lines to scroll by. It defaults to 1. Increasing this makes
1825 the console jump but can help speed up operation when scrolling
1830 Support drawing of RLE8-compressed bitmaps on the LCD.
1834 Enables an 'i2c edid' command which can read EDID
1835 information over I2C from an attached LCD display.
1837 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1839 If this option is set, the environment is checked for
1840 a variable "splashimage". If found, the usual display
1841 of logo, copyright and system information on the LCD
1842 is suppressed and the BMP image at the address
1843 specified in "splashimage" is loaded instead. The
1844 console is redirected to the "nulldev", too. This
1845 allows for a "silent" boot where a splash screen is
1846 loaded very quickly after power-on.
1848 CONFIG_SPLASHIMAGE_GUARD
1850 If this option is set, then U-Boot will prevent the environment
1851 variable "splashimage" from being set to a problematic address
1852 (see README.displaying-bmps).
1853 This option is useful for targets where, due to alignment
1854 restrictions, an improperly aligned BMP image will cause a data
1855 abort. If you think you will not have problems with unaligned
1856 accesses (for example because your toolchain prevents them)
1857 there is no need to set this option.
1859 CONFIG_SPLASH_SCREEN_ALIGN
1861 If this option is set the splash image can be freely positioned
1862 on the screen. Environment variable "splashpos" specifies the
1863 position as "x,y". If a positive number is given it is used as
1864 number of pixel from left/top. If a negative number is given it
1865 is used as number of pixel from right/bottom. You can also
1866 specify 'm' for centering the image.
1869 setenv splashpos m,m
1870 => image at center of screen
1872 setenv splashpos 30,20
1873 => image at x = 30 and y = 20
1875 setenv splashpos -10,m
1876 => vertically centered image
1877 at x = dspWidth - bmpWidth - 9
1879 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1881 If this option is set, additionally to standard BMP
1882 images, gzipped BMP images can be displayed via the
1883 splashscreen support or the bmp command.
1885 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1887 If this option is set, 8-bit RLE compressed BMP images
1888 can be displayed via the splashscreen support or the
1891 - Do compresssing for memory range:
1894 If this option is set, it would use zlib deflate method
1895 to compress the specified memory at its best effort.
1897 - Compression support:
1900 Enabled by default to support gzip compressed images.
1904 If this option is set, support for bzip2 compressed
1905 images is included. If not, only uncompressed and gzip
1906 compressed images are supported.
1908 NOTE: the bzip2 algorithm requires a lot of RAM, so
1909 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1914 If this option is set, support for lzma compressed
1917 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1918 requires an amount of dynamic memory that is given by the
1921 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1923 Where lc and lp stand for, respectively, Literal context bits
1924 and Literal pos bits.
1926 This value is upper-bounded by 14MB in the worst case. Anyway,
1927 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1928 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1929 a very small buffer.
1931 Use the lzmainfo tool to determinate the lc and lp values and
1932 then calculate the amount of needed dynamic memory (ensuring
1933 the appropriate CONFIG_SYS_MALLOC_LEN value).
1937 If this option is set, support for LZO compressed images
1943 The address of PHY on MII bus.
1945 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1947 The clock frequency of the MII bus
1951 If this option is set, support for speed/duplex
1952 detection of gigabit PHY is included.
1954 CONFIG_PHY_RESET_DELAY
1956 Some PHY like Intel LXT971A need extra delay after
1957 reset before any MII register access is possible.
1958 For such PHY, set this option to the usec delay
1959 required. (minimum 300usec for LXT971A)
1961 CONFIG_PHY_CMD_DELAY (ppc4xx)
1963 Some PHY like Intel LXT971A need extra delay after
1964 command issued before MII status register can be read
1974 Define a default value for Ethernet address to use
1975 for the respective Ethernet interface, in case this
1976 is not determined automatically.
1981 Define a default value for the IP address to use for
1982 the default Ethernet interface, in case this is not
1983 determined through e.g. bootp.
1984 (Environment variable "ipaddr")
1986 - Server IP address:
1989 Defines a default value for the IP address of a TFTP
1990 server to contact when using the "tftboot" command.
1991 (Environment variable "serverip")
1993 CONFIG_KEEP_SERVERADDR
1995 Keeps the server's MAC address, in the env 'serveraddr'
1996 for passing to bootargs (like Linux's netconsole option)
1998 - Gateway IP address:
2001 Defines a default value for the IP address of the
2002 default router where packets to other networks are
2004 (Environment variable "gatewayip")
2009 Defines a default value for the subnet mask (or
2010 routing prefix) which is used to determine if an IP
2011 address belongs to the local subnet or needs to be
2012 forwarded through a router.
2013 (Environment variable "netmask")
2015 - Multicast TFTP Mode:
2018 Defines whether you want to support multicast TFTP as per
2019 rfc-2090; for example to work with atftp. Lets lots of targets
2020 tftp down the same boot image concurrently. Note: the Ethernet
2021 driver in use must provide a function: mcast() to join/leave a
2024 - BOOTP Recovery Mode:
2025 CONFIG_BOOTP_RANDOM_DELAY
2027 If you have many targets in a network that try to
2028 boot using BOOTP, you may want to avoid that all
2029 systems send out BOOTP requests at precisely the same
2030 moment (which would happen for instance at recovery
2031 from a power failure, when all systems will try to
2032 boot, thus flooding the BOOTP server. Defining
2033 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
2034 inserted before sending out BOOTP requests. The
2035 following delays are inserted then:
2037 1st BOOTP request: delay 0 ... 1 sec
2038 2nd BOOTP request: delay 0 ... 2 sec
2039 3rd BOOTP request: delay 0 ... 4 sec
2041 BOOTP requests: delay 0 ... 8 sec
2043 - DHCP Advanced Options:
2044 You can fine tune the DHCP functionality by defining
2045 CONFIG_BOOTP_* symbols:
2047 CONFIG_BOOTP_SUBNETMASK
2048 CONFIG_BOOTP_GATEWAY
2049 CONFIG_BOOTP_HOSTNAME
2050 CONFIG_BOOTP_NISDOMAIN
2051 CONFIG_BOOTP_BOOTPATH
2052 CONFIG_BOOTP_BOOTFILESIZE
2055 CONFIG_BOOTP_SEND_HOSTNAME
2056 CONFIG_BOOTP_NTPSERVER
2057 CONFIG_BOOTP_TIMEOFFSET
2058 CONFIG_BOOTP_VENDOREX
2059 CONFIG_BOOTP_MAY_FAIL
2061 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
2062 environment variable, not the BOOTP server.
2064 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
2065 after the configured retry count, the call will fail
2066 instead of starting over. This can be used to fail over
2067 to Link-local IP address configuration if the DHCP server
2070 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
2071 serverip from a DHCP server, it is possible that more
2072 than one DNS serverip is offered to the client.
2073 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2074 serverip will be stored in the additional environment
2075 variable "dnsip2". The first DNS serverip is always
2076 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2079 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2080 to do a dynamic update of a DNS server. To do this, they
2081 need the hostname of the DHCP requester.
2082 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2083 of the "hostname" environment variable is passed as
2084 option 12 to the DHCP server.
2086 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2088 A 32bit value in microseconds for a delay between
2089 receiving a "DHCP Offer" and sending the "DHCP Request".
2090 This fixes a problem with certain DHCP servers that don't
2091 respond 100% of the time to a "DHCP request". E.g. On an
2092 AT91RM9200 processor running at 180MHz, this delay needed
2093 to be *at least* 15,000 usec before a Windows Server 2003
2094 DHCP server would reply 100% of the time. I recommend at
2095 least 50,000 usec to be safe. The alternative is to hope
2096 that one of the retries will be successful but note that
2097 the DHCP timeout and retry process takes a longer than
2100 - Link-local IP address negotiation:
2101 Negotiate with other link-local clients on the local network
2102 for an address that doesn't require explicit configuration.
2103 This is especially useful if a DHCP server cannot be guaranteed
2104 to exist in all environments that the device must operate.
2106 See doc/README.link-local for more information.
2109 CONFIG_CDP_DEVICE_ID
2111 The device id used in CDP trigger frames.
2113 CONFIG_CDP_DEVICE_ID_PREFIX
2115 A two character string which is prefixed to the MAC address
2120 A printf format string which contains the ascii name of
2121 the port. Normally is set to "eth%d" which sets
2122 eth0 for the first Ethernet, eth1 for the second etc.
2124 CONFIG_CDP_CAPABILITIES
2126 A 32bit integer which indicates the device capabilities;
2127 0x00000010 for a normal host which does not forwards.
2131 An ascii string containing the version of the software.
2135 An ascii string containing the name of the platform.
2139 A 32bit integer sent on the trigger.
2141 CONFIG_CDP_POWER_CONSUMPTION
2143 A 16bit integer containing the power consumption of the
2144 device in .1 of milliwatts.
2146 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2148 A byte containing the id of the VLAN.
2150 - Status LED: CONFIG_STATUS_LED
2152 Several configurations allow to display the current
2153 status using a LED. For instance, the LED will blink
2154 fast while running U-Boot code, stop blinking as
2155 soon as a reply to a BOOTP request was received, and
2156 start blinking slow once the Linux kernel is running
2157 (supported by a status LED driver in the Linux
2158 kernel). Defining CONFIG_STATUS_LED enables this
2164 The status LED can be connected to a GPIO pin.
2165 In such cases, the gpio_led driver can be used as a
2166 status LED backend implementation. Define CONFIG_GPIO_LED
2167 to include the gpio_led driver in the U-Boot binary.
2169 CONFIG_GPIO_LED_INVERTED_TABLE
2170 Some GPIO connected LEDs may have inverted polarity in which
2171 case the GPIO high value corresponds to LED off state and
2172 GPIO low value corresponds to LED on state.
2173 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2174 with a list of GPIO LEDs that have inverted polarity.
2176 - CAN Support: CONFIG_CAN_DRIVER
2178 Defining CONFIG_CAN_DRIVER enables CAN driver support
2179 on those systems that support this (optional)
2180 feature, like the TQM8xxL modules.
2182 - I2C Support: CONFIG_SYS_I2C
2184 This enable the NEW i2c subsystem, and will allow you to use
2185 i2c commands at the u-boot command line (as long as you set
2186 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2187 based realtime clock chips or other i2c devices. See
2188 common/cmd_i2c.c for a description of the command line
2191 ported i2c driver to the new framework:
2192 - drivers/i2c/soft_i2c.c:
2193 - activate first bus with CONFIG_SYS_I2C_SOFT define
2194 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2195 for defining speed and slave address
2196 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2197 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2198 for defining speed and slave address
2199 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2200 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2201 for defining speed and slave address
2202 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2203 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2204 for defining speed and slave address
2206 - drivers/i2c/fsl_i2c.c:
2207 - activate i2c driver with CONFIG_SYS_I2C_FSL
2208 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2209 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2210 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2212 - If your board supports a second fsl i2c bus, define
2213 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2214 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2215 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2218 - drivers/i2c/tegra_i2c.c:
2219 - activate this driver with CONFIG_SYS_I2C_TEGRA
2220 - This driver adds 4 i2c buses with a fix speed from
2221 100000 and the slave addr 0!
2223 - drivers/i2c/ppc4xx_i2c.c
2224 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2225 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2226 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2228 - drivers/i2c/i2c_mxc.c
2229 - activate this driver with CONFIG_SYS_I2C_MXC
2230 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2231 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2232 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2233 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2234 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2235 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2236 If thoses defines are not set, default value is 100000
2237 for speed, and 0 for slave.
2239 - drivers/i2c/rcar_i2c.c:
2240 - activate this driver with CONFIG_SYS_I2C_RCAR
2241 - This driver adds 4 i2c buses
2243 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2244 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2245 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2246 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2247 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2248 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2249 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2250 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2251 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2253 - drivers/i2c/sh_i2c.c:
2254 - activate this driver with CONFIG_SYS_I2C_SH
2255 - This driver adds from 2 to 5 i2c buses
2257 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2258 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2259 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2260 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2261 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2262 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2263 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2264 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2265 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2266 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2267 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2268 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2269 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2271 - drivers/i2c/omap24xx_i2c.c
2272 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2273 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2274 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2275 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2276 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2277 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2278 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2279 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2280 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2281 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2282 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2284 - drivers/i2c/zynq_i2c.c
2285 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2286 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2287 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2289 - drivers/i2c/s3c24x0_i2c.c:
2290 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2291 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2292 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2293 with a fix speed from 100000 and the slave addr 0!
2295 - drivers/i2c/ihs_i2c.c
2296 - activate this driver with CONFIG_SYS_I2C_IHS
2297 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
2298 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
2299 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
2300 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
2301 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
2302 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
2303 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
2304 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
2305 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
2306 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
2307 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
2308 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
2312 CONFIG_SYS_NUM_I2C_BUSES
2313 Hold the number of i2c busses you want to use. If you
2314 don't use/have i2c muxes on your i2c bus, this
2315 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2318 CONFIG_SYS_I2C_DIRECT_BUS
2319 define this, if you don't use i2c muxes on your hardware.
2320 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2323 CONFIG_SYS_I2C_MAX_HOPS
2324 define how many muxes are maximal consecutively connected
2325 on one i2c bus. If you not use i2c muxes, omit this
2328 CONFIG_SYS_I2C_BUSES
2329 hold a list of busses you want to use, only used if
2330 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2331 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2332 CONFIG_SYS_NUM_I2C_BUSES = 9:
2334 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2335 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2336 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2337 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2338 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2339 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2340 {1, {I2C_NULL_HOP}}, \
2341 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2342 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2346 bus 0 on adapter 0 without a mux
2347 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2348 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2349 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2350 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2351 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2352 bus 6 on adapter 1 without a mux
2353 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2354 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2356 If you do not have i2c muxes on your board, omit this define.
2358 - Legacy I2C Support: CONFIG_HARD_I2C
2360 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2361 provides the following compelling advantages:
2363 - more than one i2c adapter is usable
2364 - approved multibus support
2365 - better i2c mux support
2367 ** Please consider updating your I2C driver now. **
2369 These enable legacy I2C serial bus commands. Defining
2370 CONFIG_HARD_I2C will include the appropriate I2C driver
2371 for the selected CPU.
2373 This will allow you to use i2c commands at the u-boot
2374 command line (as long as you set CONFIG_CMD_I2C in
2375 CONFIG_COMMANDS) and communicate with i2c based realtime
2376 clock chips. See common/cmd_i2c.c for a description of the
2377 command line interface.
2379 CONFIG_HARD_I2C selects a hardware I2C controller.
2381 There are several other quantities that must also be
2382 defined when you define CONFIG_HARD_I2C.
2384 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2385 to be the frequency (in Hz) at which you wish your i2c bus
2386 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2387 the CPU's i2c node address).
2389 Now, the u-boot i2c code for the mpc8xx
2390 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2391 and so its address should therefore be cleared to 0 (See,
2392 eg, MPC823e User's Manual p.16-473). So, set
2393 CONFIG_SYS_I2C_SLAVE to 0.
2395 CONFIG_SYS_I2C_INIT_MPC5XXX
2397 When a board is reset during an i2c bus transfer
2398 chips might think that the current transfer is still
2399 in progress. Reset the slave devices by sending start
2400 commands until the slave device responds.
2402 That's all that's required for CONFIG_HARD_I2C.
2404 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2405 then the following macros need to be defined (examples are
2406 from include/configs/lwmon.h):
2410 (Optional). Any commands necessary to enable the I2C
2411 controller or configure ports.
2413 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2417 (Only for MPC8260 CPU). The I/O port to use (the code
2418 assumes both bits are on the same port). Valid values
2419 are 0..3 for ports A..D.
2423 The code necessary to make the I2C data line active
2424 (driven). If the data line is open collector, this
2427 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2431 The code necessary to make the I2C data line tri-stated
2432 (inactive). If the data line is open collector, this
2435 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2439 Code that returns true if the I2C data line is high,
2442 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2446 If <bit> is true, sets the I2C data line high. If it
2447 is false, it clears it (low).
2449 eg: #define I2C_SDA(bit) \
2450 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2451 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2455 If <bit> is true, sets the I2C clock line high. If it
2456 is false, it clears it (low).
2458 eg: #define I2C_SCL(bit) \
2459 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2460 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2464 This delay is invoked four times per clock cycle so this
2465 controls the rate of data transfer. The data rate thus
2466 is 1 / (I2C_DELAY * 4). Often defined to be something
2469 #define I2C_DELAY udelay(2)
2471 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2473 If your arch supports the generic GPIO framework (asm/gpio.h),
2474 then you may alternatively define the two GPIOs that are to be
2475 used as SCL / SDA. Any of the previous I2C_xxx macros will
2476 have GPIO-based defaults assigned to them as appropriate.
2478 You should define these to the GPIO value as given directly to
2479 the generic GPIO functions.
2481 CONFIG_SYS_I2C_INIT_BOARD
2483 When a board is reset during an i2c bus transfer
2484 chips might think that the current transfer is still
2485 in progress. On some boards it is possible to access
2486 the i2c SCLK line directly, either by using the
2487 processor pin as a GPIO or by having a second pin
2488 connected to the bus. If this option is defined a
2489 custom i2c_init_board() routine in boards/xxx/board.c
2490 is run early in the boot sequence.
2492 CONFIG_SYS_I2C_BOARD_LATE_INIT
2494 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2495 defined a custom i2c_board_late_init() routine in
2496 boards/xxx/board.c is run AFTER the operations in i2c_init()
2497 is completed. This callpoint can be used to unreset i2c bus
2498 using CPU i2c controller register accesses for CPUs whose i2c
2499 controller provide such a method. It is called at the end of
2500 i2c_init() to allow i2c_init operations to setup the i2c bus
2501 controller on the CPU (e.g. setting bus speed & slave address).
2503 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2505 This option enables configuration of bi_iic_fast[] flags
2506 in u-boot bd_info structure based on u-boot environment
2507 variable "i2cfast". (see also i2cfast)
2509 CONFIG_I2C_MULTI_BUS
2511 This option allows the use of multiple I2C buses, each of which
2512 must have a controller. At any point in time, only one bus is
2513 active. To switch to a different bus, use the 'i2c dev' command.
2514 Note that bus numbering is zero-based.
2516 CONFIG_SYS_I2C_NOPROBES
2518 This option specifies a list of I2C devices that will be skipped
2519 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2520 is set, specify a list of bus-device pairs. Otherwise, specify
2521 a 1D array of device addresses
2524 #undef CONFIG_I2C_MULTI_BUS
2525 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2527 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2529 #define CONFIG_I2C_MULTI_BUS
2530 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2532 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2534 CONFIG_SYS_SPD_BUS_NUM
2536 If defined, then this indicates the I2C bus number for DDR SPD.
2537 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2539 CONFIG_SYS_RTC_BUS_NUM
2541 If defined, then this indicates the I2C bus number for the RTC.
2542 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2544 CONFIG_SYS_DTT_BUS_NUM
2546 If defined, then this indicates the I2C bus number for the DTT.
2547 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2549 CONFIG_SYS_I2C_DTT_ADDR:
2551 If defined, specifies the I2C address of the DTT device.
2552 If not defined, then U-Boot uses predefined value for
2553 specified DTT device.
2555 CONFIG_SOFT_I2C_READ_REPEATED_START
2557 defining this will force the i2c_read() function in
2558 the soft_i2c driver to perform an I2C repeated start
2559 between writing the address pointer and reading the
2560 data. If this define is omitted the default behaviour
2561 of doing a stop-start sequence will be used. Most I2C
2562 devices can use either method, but some require one or
2565 - SPI Support: CONFIG_SPI
2567 Enables SPI driver (so far only tested with
2568 SPI EEPROM, also an instance works with Crystal A/D and
2569 D/As on the SACSng board)
2573 Enables the driver for SPI controller on SuperH. Currently
2574 only SH7757 is supported.
2578 Enables extended (16-bit) SPI EEPROM addressing.
2579 (symmetrical to CONFIG_I2C_X)
2583 Enables a software (bit-bang) SPI driver rather than
2584 using hardware support. This is a general purpose
2585 driver that only requires three general I/O port pins
2586 (two outputs, one input) to function. If this is
2587 defined, the board configuration must define several
2588 SPI configuration items (port pins to use, etc). For
2589 an example, see include/configs/sacsng.h.
2593 Enables a hardware SPI driver for general-purpose reads
2594 and writes. As with CONFIG_SOFT_SPI, the board configuration
2595 must define a list of chip-select function pointers.
2596 Currently supported on some MPC8xxx processors. For an
2597 example, see include/configs/mpc8349emds.h.
2601 Enables the driver for the SPI controllers on i.MX and MXC
2602 SoCs. Currently i.MX31/35/51 are supported.
2604 - FPGA Support: CONFIG_FPGA
2606 Enables FPGA subsystem.
2608 CONFIG_FPGA_<vendor>
2610 Enables support for specific chip vendors.
2613 CONFIG_FPGA_<family>
2615 Enables support for FPGA family.
2616 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2620 Specify the number of FPGA devices to support.
2622 CONFIG_CMD_FPGA_LOADMK
2624 Enable support for fpga loadmk command
2626 CONFIG_CMD_FPGA_LOADP
2628 Enable support for fpga loadp command - load partial bitstream
2630 CONFIG_CMD_FPGA_LOADBP
2632 Enable support for fpga loadbp command - load partial bitstream
2635 CONFIG_SYS_FPGA_PROG_FEEDBACK
2637 Enable printing of hash marks during FPGA configuration.
2639 CONFIG_SYS_FPGA_CHECK_BUSY
2641 Enable checks on FPGA configuration interface busy
2642 status by the configuration function. This option
2643 will require a board or device specific function to
2648 If defined, a function that provides delays in the FPGA
2649 configuration driver.
2651 CONFIG_SYS_FPGA_CHECK_CTRLC
2652 Allow Control-C to interrupt FPGA configuration
2654 CONFIG_SYS_FPGA_CHECK_ERROR
2656 Check for configuration errors during FPGA bitfile
2657 loading. For example, abort during Virtex II
2658 configuration if the INIT_B line goes low (which
2659 indicated a CRC error).
2661 CONFIG_SYS_FPGA_WAIT_INIT
2663 Maximum time to wait for the INIT_B line to deassert
2664 after PROB_B has been deasserted during a Virtex II
2665 FPGA configuration sequence. The default time is 500
2668 CONFIG_SYS_FPGA_WAIT_BUSY
2670 Maximum time to wait for BUSY to deassert during
2671 Virtex II FPGA configuration. The default is 5 ms.
2673 CONFIG_SYS_FPGA_WAIT_CONFIG
2675 Time to wait after FPGA configuration. The default is
2678 - Configuration Management:
2681 If defined, this string will be added to the U-Boot
2682 version information (U_BOOT_VERSION)
2684 - Vendor Parameter Protection:
2686 U-Boot considers the values of the environment
2687 variables "serial#" (Board Serial Number) and
2688 "ethaddr" (Ethernet Address) to be parameters that
2689 are set once by the board vendor / manufacturer, and
2690 protects these variables from casual modification by
2691 the user. Once set, these variables are read-only,
2692 and write or delete attempts are rejected. You can
2693 change this behaviour:
2695 If CONFIG_ENV_OVERWRITE is #defined in your config
2696 file, the write protection for vendor parameters is
2697 completely disabled. Anybody can change or delete
2700 Alternatively, if you #define _both_ CONFIG_ETHADDR
2701 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2702 Ethernet address is installed in the environment,
2703 which can be changed exactly ONCE by the user. [The
2704 serial# is unaffected by this, i. e. it remains
2707 The same can be accomplished in a more flexible way
2708 for any variable by configuring the type of access
2709 to allow for those variables in the ".flags" variable
2710 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2715 Define this variable to enable the reservation of
2716 "protected RAM", i. e. RAM which is not overwritten
2717 by U-Boot. Define CONFIG_PRAM to hold the number of
2718 kB you want to reserve for pRAM. You can overwrite
2719 this default value by defining an environment
2720 variable "pram" to the number of kB you want to
2721 reserve. Note that the board info structure will
2722 still show the full amount of RAM. If pRAM is
2723 reserved, a new environment variable "mem" will
2724 automatically be defined to hold the amount of
2725 remaining RAM in a form that can be passed as boot
2726 argument to Linux, for instance like that:
2728 setenv bootargs ... mem=\${mem}
2731 This way you can tell Linux not to use this memory,
2732 either, which results in a memory region that will
2733 not be affected by reboots.
2735 *WARNING* If your board configuration uses automatic
2736 detection of the RAM size, you must make sure that
2737 this memory test is non-destructive. So far, the
2738 following board configurations are known to be
2741 IVMS8, IVML24, SPD8xx, TQM8xxL,
2742 HERMES, IP860, RPXlite, LWMON,
2745 - Access to physical memory region (> 4GB)
2746 Some basic support is provided for operations on memory not
2747 normally accessible to U-Boot - e.g. some architectures
2748 support access to more than 4GB of memory on 32-bit
2749 machines using physical address extension or similar.
2750 Define CONFIG_PHYSMEM to access this basic support, which
2751 currently only supports clearing the memory.
2756 Define this variable to stop the system in case of a
2757 fatal error, so that you have to reset it manually.
2758 This is probably NOT a good idea for an embedded
2759 system where you want the system to reboot
2760 automatically as fast as possible, but it may be
2761 useful during development since you can try to debug
2762 the conditions that lead to the situation.
2764 CONFIG_NET_RETRY_COUNT
2766 This variable defines the number of retries for
2767 network operations like ARP, RARP, TFTP, or BOOTP
2768 before giving up the operation. If not defined, a
2769 default value of 5 is used.
2773 Timeout waiting for an ARP reply in milliseconds.
2777 Timeout in milliseconds used in NFS protocol.
2778 If you encounter "ERROR: Cannot umount" in nfs command,
2779 try longer timeout such as
2780 #define CONFIG_NFS_TIMEOUT 10000UL
2782 - Command Interpreter:
2783 CONFIG_AUTO_COMPLETE
2785 Enable auto completion of commands using TAB.
2787 Note that this feature has NOT been implemented yet
2788 for the "hush" shell.
2791 CONFIG_SYS_HUSH_PARSER
2793 Define this variable to enable the "hush" shell (from
2794 Busybox) as command line interpreter, thus enabling
2795 powerful command line syntax like
2796 if...then...else...fi conditionals or `&&' and '||'
2797 constructs ("shell scripts").
2799 If undefined, you get the old, much simpler behaviour
2800 with a somewhat smaller memory footprint.
2803 CONFIG_SYS_PROMPT_HUSH_PS2
2805 This defines the secondary prompt string, which is
2806 printed when the command interpreter needs more input
2807 to complete a command. Usually "> ".
2811 In the current implementation, the local variables
2812 space and global environment variables space are
2813 separated. Local variables are those you define by
2814 simply typing `name=value'. To access a local
2815 variable later on, you have write `$name' or
2816 `${name}'; to execute the contents of a variable
2817 directly type `$name' at the command prompt.
2819 Global environment variables are those you use
2820 setenv/printenv to work with. To run a command stored
2821 in such a variable, you need to use the run command,
2822 and you must not use the '$' sign to access them.
2824 To store commands and special characters in a
2825 variable, please use double quotation marks
2826 surrounding the whole text of the variable, instead
2827 of the backslashes before semicolons and special
2830 - Commandline Editing and History:
2831 CONFIG_CMDLINE_EDITING
2833 Enable editing and History functions for interactive
2834 commandline input operations
2836 - Default Environment:
2837 CONFIG_EXTRA_ENV_SETTINGS
2839 Define this to contain any number of null terminated
2840 strings (variable = value pairs) that will be part of
2841 the default environment compiled into the boot image.
2843 For example, place something like this in your
2844 board's config file:
2846 #define CONFIG_EXTRA_ENV_SETTINGS \
2850 Warning: This method is based on knowledge about the
2851 internal format how the environment is stored by the
2852 U-Boot code. This is NOT an official, exported
2853 interface! Although it is unlikely that this format
2854 will change soon, there is no guarantee either.
2855 You better know what you are doing here.
2857 Note: overly (ab)use of the default environment is
2858 discouraged. Make sure to check other ways to preset
2859 the environment like the "source" command or the
2862 CONFIG_ENV_VARS_UBOOT_CONFIG
2864 Define this in order to add variables describing the
2865 U-Boot build configuration to the default environment.
2866 These will be named arch, cpu, board, vendor, and soc.
2868 Enabling this option will cause the following to be defined:
2876 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2878 Define this in order to add variables describing certain
2879 run-time determined information about the hardware to the
2880 environment. These will be named board_name, board_rev.
2882 CONFIG_DELAY_ENVIRONMENT
2884 Normally the environment is loaded when the board is
2885 intialised so that it is available to U-Boot. This inhibits
2886 that so that the environment is not available until
2887 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2888 this is instead controlled by the value of
2889 /config/load-environment.
2891 - DataFlash Support:
2892 CONFIG_HAS_DATAFLASH
2894 Defining this option enables DataFlash features and
2895 allows to read/write in Dataflash via the standard
2898 - Serial Flash support
2901 Defining this option enables SPI flash commands
2902 'sf probe/read/write/erase/update'.
2904 Usage requires an initial 'probe' to define the serial
2905 flash parameters, followed by read/write/erase/update
2908 The following defaults may be provided by the platform
2909 to handle the common case when only a single serial
2910 flash is present on the system.
2912 CONFIG_SF_DEFAULT_BUS Bus identifier
2913 CONFIG_SF_DEFAULT_CS Chip-select
2914 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2915 CONFIG_SF_DEFAULT_SPEED in Hz
2919 Define this option to include a destructive SPI flash
2922 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2924 Define this option to use the Bank addr/Extended addr
2925 support on SPI flashes which has size > 16Mbytes.
2927 CONFIG_SF_DUAL_FLASH Dual flash memories
2929 Define this option to use dual flash support where two flash
2930 memories can be connected with a given cs line.
2931 currently Xilinx Zynq qspi support these type of connections.
2933 - SystemACE Support:
2936 Adding this option adds support for Xilinx SystemACE
2937 chips attached via some sort of local bus. The address
2938 of the chip must also be defined in the
2939 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2941 #define CONFIG_SYSTEMACE
2942 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2944 When SystemACE support is added, the "ace" device type
2945 becomes available to the fat commands, i.e. fatls.
2947 - TFTP Fixed UDP Port:
2950 If this is defined, the environment variable tftpsrcp
2951 is used to supply the TFTP UDP source port value.
2952 If tftpsrcp isn't defined, the normal pseudo-random port
2953 number generator is used.
2955 Also, the environment variable tftpdstp is used to supply
2956 the TFTP UDP destination port value. If tftpdstp isn't
2957 defined, the normal port 69 is used.
2959 The purpose for tftpsrcp is to allow a TFTP server to
2960 blindly start the TFTP transfer using the pre-configured
2961 target IP address and UDP port. This has the effect of
2962 "punching through" the (Windows XP) firewall, allowing
2963 the remainder of the TFTP transfer to proceed normally.
2964 A better solution is to properly configure the firewall,
2965 but sometimes that is not allowed.
2970 This enables a generic 'hash' command which can produce
2971 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2975 Enable the hash verify command (hash -v). This adds to code
2978 CONFIG_SHA1 - support SHA1 hashing
2979 CONFIG_SHA256 - support SHA256 hashing
2981 Note: There is also a sha1sum command, which should perhaps
2982 be deprecated in favour of 'hash sha1'.
2984 - Freescale i.MX specific commands:
2985 CONFIG_CMD_HDMIDETECT
2986 This enables 'hdmidet' command which returns true if an
2987 HDMI monitor is detected. This command is i.MX 6 specific.
2990 This enables the 'bmode' (bootmode) command for forcing
2991 a boot from specific media.
2993 This is useful for forcing the ROM's usb downloader to
2994 activate upon a watchdog reset which is nice when iterating
2995 on U-Boot. Using the reset button or running bmode normal
2996 will set it back to normal. This command currently
2997 supports i.MX53 and i.MX6.
3002 This enables the RSA algorithm used for FIT image verification
3003 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
3005 The signing part is build into mkimage regardless of this
3008 - bootcount support:
3009 CONFIG_BOOTCOUNT_LIMIT
3011 This enables the bootcounter support, see:
3012 http://www.denx.de/wiki/DULG/UBootBootCountLimit
3015 enable special bootcounter support on at91sam9xe based boards.
3017 enable special bootcounter support on blackfin based boards.
3019 enable special bootcounter support on da850 based boards.
3020 CONFIG_BOOTCOUNT_RAM
3021 enable support for the bootcounter in RAM
3022 CONFIG_BOOTCOUNT_I2C
3023 enable support for the bootcounter on an i2c (like RTC) device.
3024 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
3025 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
3027 CONFIG_BOOTCOUNT_ALEN = address len
3029 - Show boot progress:
3030 CONFIG_SHOW_BOOT_PROGRESS
3032 Defining this option allows to add some board-
3033 specific code (calling a user-provided function
3034 "show_boot_progress(int)") that enables you to show
3035 the system's boot progress on some display (for
3036 example, some LED's) on your board. At the moment,
3037 the following checkpoints are implemented:
3039 - Detailed boot stage timing
3041 Define this option to get detailed timing of each stage
3042 of the boot process.
3044 CONFIG_BOOTSTAGE_USER_COUNT
3045 This is the number of available user bootstage records.
3046 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
3047 a new ID will be allocated from this stash. If you exceed
3048 the limit, recording will stop.
3050 CONFIG_BOOTSTAGE_REPORT
3051 Define this to print a report before boot, similar to this:
3053 Timer summary in microseconds:
3056 3,575,678 3,575,678 board_init_f start
3057 3,575,695 17 arch_cpu_init A9
3058 3,575,777 82 arch_cpu_init done
3059 3,659,598 83,821 board_init_r start
3060 3,910,375 250,777 main_loop
3061 29,916,167 26,005,792 bootm_start
3062 30,361,327 445,160 start_kernel
3064 CONFIG_CMD_BOOTSTAGE
3065 Add a 'bootstage' command which supports printing a report
3066 and un/stashing of bootstage data.
3068 CONFIG_BOOTSTAGE_FDT
3069 Stash the bootstage information in the FDT. A root 'bootstage'
3070 node is created with each bootstage id as a child. Each child
3071 has a 'name' property and either 'mark' containing the
3072 mark time in microsecond, or 'accum' containing the
3073 accumulated time for that bootstage id in microseconds.
3078 name = "board_init_f";
3087 Code in the Linux kernel can find this in /proc/devicetree.
3089 Legacy uImage format:
3092 1 common/cmd_bootm.c before attempting to boot an image
3093 -1 common/cmd_bootm.c Image header has bad magic number
3094 2 common/cmd_bootm.c Image header has correct magic number
3095 -2 common/cmd_bootm.c Image header has bad checksum
3096 3 common/cmd_bootm.c Image header has correct checksum
3097 -3 common/cmd_bootm.c Image data has bad checksum
3098 4 common/cmd_bootm.c Image data has correct checksum
3099 -4 common/cmd_bootm.c Image is for unsupported architecture
3100 5 common/cmd_bootm.c Architecture check OK
3101 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3102 6 common/cmd_bootm.c Image Type check OK
3103 -6 common/cmd_bootm.c gunzip uncompression error
3104 -7 common/cmd_bootm.c Unimplemented compression type
3105 7 common/cmd_bootm.c Uncompression OK
3106 8 common/cmd_bootm.c No uncompress/copy overwrite error
3107 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3109 9 common/image.c Start initial ramdisk verification
3110 -10 common/image.c Ramdisk header has bad magic number
3111 -11 common/image.c Ramdisk header has bad checksum
3112 10 common/image.c Ramdisk header is OK
3113 -12 common/image.c Ramdisk data has bad checksum
3114 11 common/image.c Ramdisk data has correct checksum
3115 12 common/image.c Ramdisk verification complete, start loading
3116 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3117 13 common/image.c Start multifile image verification
3118 14 common/image.c No initial ramdisk, no multifile, continue.
3120 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3122 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3123 -31 post/post.c POST test failed, detected by post_output_backlog()
3124 -32 post/post.c POST test failed, detected by post_run_single()
3126 34 common/cmd_doc.c before loading a Image from a DOC device
3127 -35 common/cmd_doc.c Bad usage of "doc" command
3128 35 common/cmd_doc.c correct usage of "doc" command
3129 -36 common/cmd_doc.c No boot device
3130 36 common/cmd_doc.c correct boot device
3131 -37 common/cmd_doc.c Unknown Chip ID on boot device
3132 37 common/cmd_doc.c correct chip ID found, device available
3133 -38 common/cmd_doc.c Read Error on boot device
3134 38 common/cmd_doc.c reading Image header from DOC device OK
3135 -39 common/cmd_doc.c Image header has bad magic number
3136 39 common/cmd_doc.c Image header has correct magic number
3137 -40 common/cmd_doc.c Error reading Image from DOC device
3138 40 common/cmd_doc.c Image header has correct magic number
3139 41 common/cmd_ide.c before loading a Image from a IDE device
3140 -42 common/cmd_ide.c Bad usage of "ide" command
3141 42 common/cmd_ide.c correct usage of "ide" command
3142 -43 common/cmd_ide.c No boot device
3143 43 common/cmd_ide.c boot device found
3144 -44 common/cmd_ide.c Device not available
3145 44 common/cmd_ide.c Device available
3146 -45 common/cmd_ide.c wrong partition selected
3147 45 common/cmd_ide.c partition selected
3148 -46 common/cmd_ide.c Unknown partition table
3149 46 common/cmd_ide.c valid partition table found
3150 -47 common/cmd_ide.c Invalid partition type
3151 47 common/cmd_ide.c correct partition type
3152 -48 common/cmd_ide.c Error reading Image Header on boot device
3153 48 common/cmd_ide.c reading Image Header from IDE device OK
3154 -49 common/cmd_ide.c Image header has bad magic number
3155 49 common/cmd_ide.c Image header has correct magic number
3156 -50 common/cmd_ide.c Image header has bad checksum
3157 50 common/cmd_ide.c Image header has correct checksum
3158 -51 common/cmd_ide.c Error reading Image from IDE device
3159 51 common/cmd_ide.c reading Image from IDE device OK
3160 52 common/cmd_nand.c before loading a Image from a NAND device
3161 -53 common/cmd_nand.c Bad usage of "nand" command
3162 53 common/cmd_nand.c correct usage of "nand" command
3163 -54 common/cmd_nand.c No boot device
3164 54 common/cmd_nand.c boot device found
3165 -55 common/cmd_nand.c Unknown Chip ID on boot device
3166 55 common/cmd_nand.c correct chip ID found, device available
3167 -56 common/cmd_nand.c Error reading Image Header on boot device
3168 56 common/cmd_nand.c reading Image Header from NAND device OK
3169 -57 common/cmd_nand.c Image header has bad magic number
3170 57 common/cmd_nand.c Image header has correct magic number
3171 -58 common/cmd_nand.c Error reading Image from NAND device
3172 58 common/cmd_nand.c reading Image from NAND device OK
3174 -60 common/env_common.c Environment has a bad CRC, using default
3176 64 net/eth.c starting with Ethernet configuration.
3177 -64 net/eth.c no Ethernet found.
3178 65 net/eth.c Ethernet found.
3180 -80 common/cmd_net.c usage wrong
3181 80 common/cmd_net.c before calling NetLoop()
3182 -81 common/cmd_net.c some error in NetLoop() occurred
3183 81 common/cmd_net.c NetLoop() back without error
3184 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3185 82 common/cmd_net.c trying automatic boot
3186 83 common/cmd_net.c running "source" command
3187 -83 common/cmd_net.c some error in automatic boot or "source" command
3188 84 common/cmd_net.c end without errors
3193 100 common/cmd_bootm.c Kernel FIT Image has correct format
3194 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3195 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3196 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3197 102 common/cmd_bootm.c Kernel unit name specified
3198 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3199 103 common/cmd_bootm.c Found configuration node
3200 104 common/cmd_bootm.c Got kernel subimage node offset
3201 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3202 105 common/cmd_bootm.c Kernel subimage hash verification OK
3203 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3204 106 common/cmd_bootm.c Architecture check OK
3205 -106 common/cmd_bootm.c Kernel subimage has wrong type
3206 107 common/cmd_bootm.c Kernel subimage type OK
3207 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3208 108 common/cmd_bootm.c Got kernel subimage data/size
3209 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3210 -109 common/cmd_bootm.c Can't get kernel subimage type
3211 -110 common/cmd_bootm.c Can't get kernel subimage comp
3212 -111 common/cmd_bootm.c Can't get kernel subimage os
3213 -112 common/cmd_bootm.c Can't get kernel subimage load address
3214 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3216 120 common/image.c Start initial ramdisk verification
3217 -120 common/image.c Ramdisk FIT image has incorrect format
3218 121 common/image.c Ramdisk FIT image has correct format
3219 122 common/image.c No ramdisk subimage unit name, using configuration
3220 -122 common/image.c Can't get configuration for ramdisk subimage
3221 123 common/image.c Ramdisk unit name specified
3222 -124 common/image.c Can't get ramdisk subimage node offset
3223 125 common/image.c Got ramdisk subimage node offset
3224 -125 common/image.c Ramdisk subimage hash verification failed
3225 126 common/image.c Ramdisk subimage hash verification OK
3226 -126 common/image.c Ramdisk subimage for unsupported architecture
3227 127 common/image.c Architecture check OK
3228 -127 common/image.c Can't get ramdisk subimage data/size
3229 128 common/image.c Got ramdisk subimage data/size
3230 129 common/image.c Can't get ramdisk load address
3231 -129 common/image.c Got ramdisk load address
3233 -130 common/cmd_doc.c Incorrect FIT image format
3234 131 common/cmd_doc.c FIT image format OK
3236 -140 common/cmd_ide.c Incorrect FIT image format
3237 141 common/cmd_ide.c FIT image format OK
3239 -150 common/cmd_nand.c Incorrect FIT image format
3240 151 common/cmd_nand.c FIT image format OK
3242 - legacy image format:
3243 CONFIG_IMAGE_FORMAT_LEGACY
3244 enables the legacy image format support in U-Boot.
3247 enabled if CONFIG_FIT_SIGNATURE is not defined.
3249 CONFIG_DISABLE_IMAGE_LEGACY
3250 disable the legacy image format
3252 This define is introduced, as the legacy image format is
3253 enabled per default for backward compatibility.
3255 - FIT image support:
3257 Enable support for the FIT uImage format.
3259 CONFIG_FIT_BEST_MATCH
3260 When no configuration is explicitly selected, default to the
3261 one whose fdt's compatibility field best matches that of
3262 U-Boot itself. A match is considered "best" if it matches the
3263 most specific compatibility entry of U-Boot's fdt's root node.
3264 The order of entries in the configuration's fdt is ignored.
3266 CONFIG_FIT_SIGNATURE
3267 This option enables signature verification of FIT uImages,
3268 using a hash signed and verified using RSA. See
3269 doc/uImage.FIT/signature.txt for more details.
3271 WARNING: When relying on signed FIT images with required
3272 signature check the legacy image format is default
3273 disabled. If a board need legacy image format support
3274 enable this through CONFIG_IMAGE_FORMAT_LEGACY
3276 CONFIG_FIT_DISABLE_SHA256
3277 Supporting SHA256 hashes has quite an impact on binary size.
3278 For constrained systems sha256 hash support can be disabled
3281 - Standalone program support:
3282 CONFIG_STANDALONE_LOAD_ADDR
3284 This option defines a board specific value for the
3285 address where standalone program gets loaded, thus
3286 overwriting the architecture dependent default
3289 - Frame Buffer Address:
3292 Define CONFIG_FB_ADDR if you want to use specific
3293 address for frame buffer. This is typically the case
3294 when using a graphics controller has separate video
3295 memory. U-Boot will then place the frame buffer at
3296 the given address instead of dynamically reserving it
3297 in system RAM by calling lcd_setmem(), which grabs
3298 the memory for the frame buffer depending on the
3299 configured panel size.
3301 Please see board_init_f function.
3303 - Automatic software updates via TFTP server
3305 CONFIG_UPDATE_TFTP_CNT_MAX
3306 CONFIG_UPDATE_TFTP_MSEC_MAX
3308 These options enable and control the auto-update feature;
3309 for a more detailed description refer to doc/README.update.
3311 - MTD Support (mtdparts command, UBI support)
3314 Adds the MTD device infrastructure from the Linux kernel.
3315 Needed for mtdparts command support.
3317 CONFIG_MTD_PARTITIONS
3319 Adds the MTD partitioning infrastructure from the Linux
3320 kernel. Needed for UBI support.
3325 Adds commands for interacting with MTD partitions formatted
3326 with the UBI flash translation layer
3328 Requires also defining CONFIG_RBTREE
3330 CONFIG_UBI_SILENCE_MSG
3332 Make the verbose messages from UBI stop printing. This leaves
3333 warnings and errors enabled.
3338 Adds commands for interacting with UBI volumes formatted as
3339 UBIFS. UBIFS is read-only in u-boot.
3341 Requires UBI support as well as CONFIG_LZO
3343 CONFIG_UBIFS_SILENCE_MSG
3345 Make the verbose messages from UBIFS stop printing. This leaves
3346 warnings and errors enabled.
3350 Enable building of SPL globally.
3353 LDSCRIPT for linking the SPL binary.
3355 CONFIG_SPL_MAX_FOOTPRINT
3356 Maximum size in memory allocated to the SPL, BSS included.
3357 When defined, the linker checks that the actual memory
3358 used by SPL from _start to __bss_end does not exceed it.
3359 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3360 must not be both defined at the same time.
3363 Maximum size of the SPL image (text, data, rodata, and
3364 linker lists sections), BSS excluded.
3365 When defined, the linker checks that the actual size does
3368 CONFIG_SPL_TEXT_BASE
3369 TEXT_BASE for linking the SPL binary.
3371 CONFIG_SPL_RELOC_TEXT_BASE
3372 Address to relocate to. If unspecified, this is equal to
3373 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3375 CONFIG_SPL_BSS_START_ADDR
3376 Link address for the BSS within the SPL binary.
3378 CONFIG_SPL_BSS_MAX_SIZE
3379 Maximum size in memory allocated to the SPL BSS.
3380 When defined, the linker checks that the actual memory used
3381 by SPL from __bss_start to __bss_end does not exceed it.
3382 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3383 must not be both defined at the same time.
3386 Adress of the start of the stack SPL will use
3388 CONFIG_SPL_RELOC_STACK
3389 Adress of the start of the stack SPL will use after
3390 relocation. If unspecified, this is equal to
3393 CONFIG_SYS_SPL_MALLOC_START
3394 Starting address of the malloc pool used in SPL.
3396 CONFIG_SYS_SPL_MALLOC_SIZE
3397 The size of the malloc pool used in SPL.
3399 CONFIG_SPL_FRAMEWORK
3400 Enable the SPL framework under common/. This framework
3401 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3402 NAND loading of the Linux Kernel.
3405 Enable booting directly to an OS from SPL.
3406 See also: doc/README.falcon
3408 CONFIG_SPL_DISPLAY_PRINT
3409 For ARM, enable an optional function to print more information
3410 about the running system.
3412 CONFIG_SPL_INIT_MINIMAL
3413 Arch init code should be built for a very small image
3415 CONFIG_SPL_LIBCOMMON_SUPPORT
3416 Support for common/libcommon.o in SPL binary
3418 CONFIG_SPL_LIBDISK_SUPPORT
3419 Support for disk/libdisk.o in SPL binary
3421 CONFIG_SPL_I2C_SUPPORT
3422 Support for drivers/i2c/libi2c.o in SPL binary
3424 CONFIG_SPL_GPIO_SUPPORT
3425 Support for drivers/gpio/libgpio.o in SPL binary
3427 CONFIG_SPL_MMC_SUPPORT
3428 Support for drivers/mmc/libmmc.o in SPL binary
3430 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3431 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3432 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3433 Address, size and partition on the MMC to load U-Boot from
3434 when the MMC is being used in raw mode.
3436 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3437 Sector to load kernel uImage from when MMC is being
3438 used in raw mode (for Falcon mode)
3440 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3441 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3442 Sector and number of sectors to load kernel argument
3443 parameters from when MMC is being used in raw mode
3446 CONFIG_SPL_FAT_SUPPORT
3447 Support for fs/fat/libfat.o in SPL binary
3449 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3450 Filename to read to load U-Boot when reading from FAT
3452 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3453 Filename to read to load kernel uImage when reading
3454 from FAT (for Falcon mode)
3456 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3457 Filename to read to load kernel argument parameters
3458 when reading from FAT (for Falcon mode)
3460 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3461 Set this for NAND SPL on PPC mpc83xx targets, so that
3462 start.S waits for the rest of the SPL to load before
3463 continuing (the hardware starts execution after just
3464 loading the first page rather than the full 4K).
3466 CONFIG_SPL_SKIP_RELOCATE
3467 Avoid SPL relocation
3469 CONFIG_SPL_NAND_BASE
3470 Include nand_base.c in the SPL. Requires
3471 CONFIG_SPL_NAND_DRIVERS.
3473 CONFIG_SPL_NAND_DRIVERS
3474 SPL uses normal NAND drivers, not minimal drivers.
3477 Include standard software ECC in the SPL
3479 CONFIG_SPL_NAND_SIMPLE
3480 Support for NAND boot using simple NAND drivers that
3481 expose the cmd_ctrl() interface.
3483 CONFIG_SPL_MTD_SUPPORT
3484 Support for the MTD subsystem within SPL. Useful for
3485 environment on NAND support within SPL.
3487 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3488 Set for the SPL on PPC mpc8xxx targets, support for
3489 drivers/ddr/fsl/libddr.o in SPL binary.
3491 CONFIG_SPL_COMMON_INIT_DDR
3492 Set for common ddr init with serial presence detect in
3495 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3496 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3497 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3498 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3499 CONFIG_SYS_NAND_ECCBYTES
3500 Defines the size and behavior of the NAND that SPL uses
3503 CONFIG_SPL_NAND_BOOT
3504 Add support NAND boot
3506 CONFIG_SYS_NAND_U_BOOT_OFFS
3507 Location in NAND to read U-Boot from
3509 CONFIG_SYS_NAND_U_BOOT_DST
3510 Location in memory to load U-Boot to
3512 CONFIG_SYS_NAND_U_BOOT_SIZE
3513 Size of image to load
3515 CONFIG_SYS_NAND_U_BOOT_START
3516 Entry point in loaded image to jump to
3518 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3519 Define this if you need to first read the OOB and then the
3520 data. This is used for example on davinci plattforms.
3522 CONFIG_SPL_OMAP3_ID_NAND
3523 Support for an OMAP3-specific set of functions to return the
3524 ID and MFR of the first attached NAND chip, if present.
3526 CONFIG_SPL_SERIAL_SUPPORT
3527 Support for drivers/serial/libserial.o in SPL binary
3529 CONFIG_SPL_SPI_FLASH_SUPPORT
3530 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3532 CONFIG_SPL_SPI_SUPPORT
3533 Support for drivers/spi/libspi.o in SPL binary
3535 CONFIG_SPL_RAM_DEVICE
3536 Support for running image already present in ram, in SPL binary
3538 CONFIG_SPL_LIBGENERIC_SUPPORT
3539 Support for lib/libgeneric.o in SPL binary
3541 CONFIG_SPL_ENV_SUPPORT
3542 Support for the environment operating in SPL binary
3544 CONFIG_SPL_NET_SUPPORT
3545 Support for the net/libnet.o in SPL binary.
3546 It conflicts with SPL env from storage medium specified by
3547 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3550 Image offset to which the SPL should be padded before appending
3551 the SPL payload. By default, this is defined as
3552 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3553 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3554 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3557 Final target image containing SPL and payload. Some SPLs
3558 use an arch-specific makefile fragment instead, for
3559 example if more than one image needs to be produced.
3561 CONFIG_FIT_SPL_PRINT
3562 Printing information about a FIT image adds quite a bit of
3563 code to SPL. So this is normally disabled in SPL. Use this
3564 option to re-enable it. This will affect the output of the
3565 bootm command when booting a FIT image.
3569 Enable building of TPL globally.
3572 Image offset to which the TPL should be padded before appending
3573 the TPL payload. By default, this is defined as
3574 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3575 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3576 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3581 [so far only for SMDK2400 boards]
3583 - Modem support enable:
3584 CONFIG_MODEM_SUPPORT
3586 - RTS/CTS Flow control enable:
3589 - Modem debug support:
3590 CONFIG_MODEM_SUPPORT_DEBUG
3592 Enables debugging stuff (char screen[1024], dbg())
3593 for modem support. Useful only with BDI2000.
3595 - Interrupt support (PPC):
3597 There are common interrupt_init() and timer_interrupt()
3598 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3599 for CPU specific initialization. interrupt_init_cpu()
3600 should set decrementer_count to appropriate value. If
3601 CPU resets decrementer automatically after interrupt
3602 (ppc4xx) it should set decrementer_count to zero.
3603 timer_interrupt() calls timer_interrupt_cpu() for CPU
3604 specific handling. If board has watchdog / status_led
3605 / other_activity_monitor it works automatically from
3606 general timer_interrupt().
3610 In the target system modem support is enabled when a
3611 specific key (key combination) is pressed during
3612 power-on. Otherwise U-Boot will boot normally
3613 (autoboot). The key_pressed() function is called from
3614 board_init(). Currently key_pressed() is a dummy
3615 function, returning 1 and thus enabling modem
3618 If there are no modem init strings in the
3619 environment, U-Boot proceed to autoboot; the
3620 previous output (banner, info printfs) will be
3623 See also: doc/README.Modem
3625 Board initialization settings:
3626 ------------------------------
3628 During Initialization u-boot calls a number of board specific functions
3629 to allow the preparation of board specific prerequisites, e.g. pin setup
3630 before drivers are initialized. To enable these callbacks the
3631 following configuration macros have to be defined. Currently this is
3632 architecture specific, so please check arch/your_architecture/lib/board.c
3633 typically in board_init_f() and board_init_r().
3635 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3636 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3637 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3638 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3640 Configuration Settings:
3641 -----------------------
3643 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3644 Optionally it can be defined to support 64-bit memory commands.
3646 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3647 undefine this when you're short of memory.
3649 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3650 width of the commands listed in the 'help' command output.
3652 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3653 prompt for user input.
3655 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3657 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3659 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3661 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3662 the application (usually a Linux kernel) when it is
3665 - CONFIG_SYS_BAUDRATE_TABLE:
3666 List of legal baudrate settings for this board.
3668 - CONFIG_SYS_CONSOLE_INFO_QUIET
3669 Suppress display of console information at boot.
3671 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3672 If the board specific function
3673 extern int overwrite_console (void);
3674 returns 1, the stdin, stderr and stdout are switched to the
3675 serial port, else the settings in the environment are used.
3677 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3678 Enable the call to overwrite_console().
3680 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3681 Enable overwrite of previous console environment settings.
3683 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3684 Begin and End addresses of the area used by the
3687 - CONFIG_SYS_ALT_MEMTEST:
3688 Enable an alternate, more extensive memory test.
3690 - CONFIG_SYS_MEMTEST_SCRATCH:
3691 Scratch address used by the alternate memory test
3692 You only need to set this if address zero isn't writeable
3694 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3695 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3696 this specified memory area will get subtracted from the top
3697 (end) of RAM and won't get "touched" at all by U-Boot. By
3698 fixing up gd->ram_size the Linux kernel should gets passed
3699 the now "corrected" memory size and won't touch it either.
3700 This should work for arch/ppc and arch/powerpc. Only Linux
3701 board ports in arch/powerpc with bootwrapper support that
3702 recalculate the memory size from the SDRAM controller setup
3703 will have to get fixed in Linux additionally.
3705 This option can be used as a workaround for the 440EPx/GRx
3706 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3709 WARNING: Please make sure that this value is a multiple of
3710 the Linux page size (normally 4k). If this is not the case,
3711 then the end address of the Linux memory will be located at a
3712 non page size aligned address and this could cause major
3715 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3716 Enable temporary baudrate change while serial download
3718 - CONFIG_SYS_SDRAM_BASE:
3719 Physical start address of SDRAM. _Must_ be 0 here.
3721 - CONFIG_SYS_MBIO_BASE:
3722 Physical start address of Motherboard I/O (if using a
3725 - CONFIG_SYS_FLASH_BASE:
3726 Physical start address of Flash memory.
3728 - CONFIG_SYS_MONITOR_BASE:
3729 Physical start address of boot monitor code (set by
3730 make config files to be same as the text base address
3731 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3732 CONFIG_SYS_FLASH_BASE when booting from flash.
3734 - CONFIG_SYS_MONITOR_LEN:
3735 Size of memory reserved for monitor code, used to
3736 determine _at_compile_time_ (!) if the environment is
3737 embedded within the U-Boot image, or in a separate
3740 - CONFIG_SYS_MALLOC_LEN:
3741 Size of DRAM reserved for malloc() use.
3743 - CONFIG_SYS_BOOTM_LEN:
3744 Normally compressed uImages are limited to an
3745 uncompressed size of 8 MBytes. If this is not enough,
3746 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3747 to adjust this setting to your needs.
3749 - CONFIG_SYS_BOOTMAPSZ:
3750 Maximum size of memory mapped by the startup code of
3751 the Linux kernel; all data that must be processed by
3752 the Linux kernel (bd_info, boot arguments, FDT blob if
3753 used) must be put below this limit, unless "bootm_low"
3754 environment variable is defined and non-zero. In such case
3755 all data for the Linux kernel must be between "bootm_low"
3756 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3757 variable "bootm_mapsize" will override the value of
3758 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3759 then the value in "bootm_size" will be used instead.
3761 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3762 Enable initrd_high functionality. If defined then the
3763 initrd_high feature is enabled and the bootm ramdisk subcommand
3766 - CONFIG_SYS_BOOT_GET_CMDLINE:
3767 Enables allocating and saving kernel cmdline in space between
3768 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3770 - CONFIG_SYS_BOOT_GET_KBD:
3771 Enables allocating and saving a kernel copy of the bd_info in
3772 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3774 - CONFIG_SYS_MAX_FLASH_BANKS:
3775 Max number of Flash memory banks
3777 - CONFIG_SYS_MAX_FLASH_SECT:
3778 Max number of sectors on a Flash chip
3780 - CONFIG_SYS_FLASH_ERASE_TOUT:
3781 Timeout for Flash erase operations (in ms)
3783 - CONFIG_SYS_FLASH_WRITE_TOUT:
3784 Timeout for Flash write operations (in ms)
3786 - CONFIG_SYS_FLASH_LOCK_TOUT
3787 Timeout for Flash set sector lock bit operation (in ms)
3789 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3790 Timeout for Flash clear lock bits operation (in ms)
3792 - CONFIG_SYS_FLASH_PROTECTION
3793 If defined, hardware flash sectors protection is used
3794 instead of U-Boot software protection.
3796 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3798 Enable TFTP transfers directly to flash memory;
3799 without this option such a download has to be
3800 performed in two steps: (1) download to RAM, and (2)
3801 copy from RAM to flash.
3803 The two-step approach is usually more reliable, since
3804 you can check if the download worked before you erase
3805 the flash, but in some situations (when system RAM is
3806 too limited to allow for a temporary copy of the
3807 downloaded image) this option may be very useful.
3809 - CONFIG_SYS_FLASH_CFI:
3810 Define if the flash driver uses extra elements in the
3811 common flash structure for storing flash geometry.
3813 - CONFIG_FLASH_CFI_DRIVER
3814 This option also enables the building of the cfi_flash driver
3815 in the drivers directory
3817 - CONFIG_FLASH_CFI_MTD
3818 This option enables the building of the cfi_mtd driver
3819 in the drivers directory. The driver exports CFI flash
3822 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3823 Use buffered writes to flash.
3825 - CONFIG_FLASH_SPANSION_S29WS_N
3826 s29ws-n MirrorBit flash has non-standard addresses for buffered
3829 - CONFIG_SYS_FLASH_QUIET_TEST
3830 If this option is defined, the common CFI flash doesn't
3831 print it's warning upon not recognized FLASH banks. This
3832 is useful, if some of the configured banks are only
3833 optionally available.
3835 - CONFIG_FLASH_SHOW_PROGRESS
3836 If defined (must be an integer), print out countdown
3837 digits and dots. Recommended value: 45 (9..1) for 80
3838 column displays, 15 (3..1) for 40 column displays.
3840 - CONFIG_FLASH_VERIFY
3841 If defined, the content of the flash (destination) is compared
3842 against the source after the write operation. An error message
3843 will be printed when the contents are not identical.
3844 Please note that this option is useless in nearly all cases,
3845 since such flash programming errors usually are detected earlier
3846 while unprotecting/erasing/programming. Please only enable
3847 this option if you really know what you are doing.
3849 - CONFIG_SYS_RX_ETH_BUFFER:
3850 Defines the number of Ethernet receive buffers. On some
3851 Ethernet controllers it is recommended to set this value
3852 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3853 buffers can be full shortly after enabling the interface
3854 on high Ethernet traffic.
3855 Defaults to 4 if not defined.
3857 - CONFIG_ENV_MAX_ENTRIES
3859 Maximum number of entries in the hash table that is used
3860 internally to store the environment settings. The default
3861 setting is supposed to be generous and should work in most
3862 cases. This setting can be used to tune behaviour; see
3863 lib/hashtable.c for details.
3865 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3866 - CONFIG_ENV_FLAGS_LIST_STATIC
3867 Enable validation of the values given to environment variables when
3868 calling env set. Variables can be restricted to only decimal,
3869 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3870 the variables can also be restricted to IP address or MAC address.
3872 The format of the list is:
3873 type_attribute = [s|d|x|b|i|m]
3874 access_atribute = [a|r|o|c]
3875 attributes = type_attribute[access_atribute]
3876 entry = variable_name[:attributes]
3879 The type attributes are:
3880 s - String (default)
3883 b - Boolean ([1yYtT|0nNfF])
3887 The access attributes are:
3893 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3894 Define this to a list (string) to define the ".flags"
3895 envirnoment variable in the default or embedded environment.
3897 - CONFIG_ENV_FLAGS_LIST_STATIC
3898 Define this to a list (string) to define validation that
3899 should be done if an entry is not found in the ".flags"
3900 environment variable. To override a setting in the static
3901 list, simply add an entry for the same variable name to the
3904 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3905 If defined, don't allow the -f switch to env set override variable
3908 - CONFIG_SYS_GENERIC_BOARD
3909 This selects the architecture-generic board system instead of the
3910 architecture-specific board files. It is intended to move boards
3911 to this new framework over time. Defining this will disable the
3912 arch/foo/lib/board.c file and use common/board_f.c and
3913 common/board_r.c instead. To use this option your architecture
3914 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3915 its config.mk file). If you find problems enabling this option on
3916 your board please report the problem and send patches!
3918 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3919 This is set by OMAP boards for the max time that reset should
3920 be asserted. See doc/README.omap-reset-time for details on how
3921 the value can be calulated on a given board.
3923 The following definitions that deal with the placement and management
3924 of environment data (variable area); in general, we support the
3925 following configurations:
3927 - CONFIG_BUILD_ENVCRC:
3929 Builds up envcrc with the target environment so that external utils
3930 may easily extract it and embed it in final U-Boot images.
3932 - CONFIG_ENV_IS_IN_FLASH:
3934 Define this if the environment is in flash memory.
3936 a) The environment occupies one whole flash sector, which is
3937 "embedded" in the text segment with the U-Boot code. This
3938 happens usually with "bottom boot sector" or "top boot
3939 sector" type flash chips, which have several smaller
3940 sectors at the start or the end. For instance, such a
3941 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3942 such a case you would place the environment in one of the
3943 4 kB sectors - with U-Boot code before and after it. With
3944 "top boot sector" type flash chips, you would put the
3945 environment in one of the last sectors, leaving a gap
3946 between U-Boot and the environment.
3948 - CONFIG_ENV_OFFSET:
3950 Offset of environment data (variable area) to the
3951 beginning of flash memory; for instance, with bottom boot
3952 type flash chips the second sector can be used: the offset
3953 for this sector is given here.
3955 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3959 This is just another way to specify the start address of
3960 the flash sector containing the environment (instead of
3963 - CONFIG_ENV_SECT_SIZE:
3965 Size of the sector containing the environment.
3968 b) Sometimes flash chips have few, equal sized, BIG sectors.
3969 In such a case you don't want to spend a whole sector for
3974 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3975 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3976 of this flash sector for the environment. This saves
3977 memory for the RAM copy of the environment.
3979 It may also save flash memory if you decide to use this
3980 when your environment is "embedded" within U-Boot code,
3981 since then the remainder of the flash sector could be used
3982 for U-Boot code. It should be pointed out that this is
3983 STRONGLY DISCOURAGED from a robustness point of view:
3984 updating the environment in flash makes it always
3985 necessary to erase the WHOLE sector. If something goes
3986 wrong before the contents has been restored from a copy in
3987 RAM, your target system will be dead.
3989 - CONFIG_ENV_ADDR_REDUND
3990 CONFIG_ENV_SIZE_REDUND
3992 These settings describe a second storage area used to hold
3993 a redundant copy of the environment data, so that there is
3994 a valid backup copy in case there is a power failure during
3995 a "saveenv" operation.
3997 BE CAREFUL! Any changes to the flash layout, and some changes to the
3998 source code will make it necessary to adapt <board>/u-boot.lds*
4002 - CONFIG_ENV_IS_IN_NVRAM:
4004 Define this if you have some non-volatile memory device
4005 (NVRAM, battery buffered SRAM) which you want to use for the
4011 These two #defines are used to determine the memory area you
4012 want to use for environment. It is assumed that this memory
4013 can just be read and written to, without any special
4016 BE CAREFUL! The first access to the environment happens quite early
4017 in U-Boot initalization (when we try to get the setting of for the
4018 console baudrate). You *MUST* have mapped your NVRAM area then, or
4021 Please note that even with NVRAM we still use a copy of the
4022 environment in RAM: we could work on NVRAM directly, but we want to
4023 keep settings there always unmodified except somebody uses "saveenv"
4024 to save the current settings.
4027 - CONFIG_ENV_IS_IN_EEPROM:
4029 Use this if you have an EEPROM or similar serial access
4030 device and a driver for it.
4032 - CONFIG_ENV_OFFSET:
4035 These two #defines specify the offset and size of the
4036 environment area within the total memory of your EEPROM.
4038 - CONFIG_SYS_I2C_EEPROM_ADDR:
4039 If defined, specified the chip address of the EEPROM device.
4040 The default address is zero.
4042 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
4043 If defined, the number of bits used to address bytes in a
4044 single page in the EEPROM device. A 64 byte page, for example
4045 would require six bits.
4047 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
4048 If defined, the number of milliseconds to delay between
4049 page writes. The default is zero milliseconds.
4051 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
4052 The length in bytes of the EEPROM memory array address. Note
4053 that this is NOT the chip address length!
4055 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
4056 EEPROM chips that implement "address overflow" are ones
4057 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
4058 address and the extra bits end up in the "chip address" bit
4059 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
4062 Note that we consider the length of the address field to
4063 still be one byte because the extra address bits are hidden
4064 in the chip address.
4066 - CONFIG_SYS_EEPROM_SIZE:
4067 The size in bytes of the EEPROM device.
4069 - CONFIG_ENV_EEPROM_IS_ON_I2C
4070 define this, if you have I2C and SPI activated, and your
4071 EEPROM, which holds the environment, is on the I2C bus.
4073 - CONFIG_I2C_ENV_EEPROM_BUS
4074 if you have an Environment on an EEPROM reached over
4075 I2C muxes, you can define here, how to reach this
4076 EEPROM. For example:
4078 #define CONFIG_I2C_ENV_EEPROM_BUS 1
4080 EEPROM which holds the environment, is reached over
4081 a pca9547 i2c mux with address 0x70, channel 3.
4083 - CONFIG_ENV_IS_IN_DATAFLASH:
4085 Define this if you have a DataFlash memory device which you
4086 want to use for the environment.
4088 - CONFIG_ENV_OFFSET:
4092 These three #defines specify the offset and size of the
4093 environment area within the total memory of your DataFlash placed
4094 at the specified address.
4096 - CONFIG_ENV_IS_IN_SPI_FLASH:
4098 Define this if you have a SPI Flash memory device which you
4099 want to use for the environment.
4101 - CONFIG_ENV_OFFSET:
4104 These two #defines specify the offset and size of the
4105 environment area within the SPI Flash. CONFIG_ENV_OFFSET must be
4106 aligned to an erase sector boundary.
4108 - CONFIG_ENV_SECT_SIZE:
4110 Define the SPI flash's sector size.
4112 - CONFIG_ENV_OFFSET_REDUND (optional):
4114 This setting describes a second storage area of CONFIG_ENV_SIZE
4115 size used to hold a redundant copy of the environment data, so
4116 that there is a valid backup copy in case there is a power failure
4117 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4118 aligned to an erase sector boundary.
4120 - CONFIG_ENV_SPI_BUS (optional):
4121 - CONFIG_ENV_SPI_CS (optional):
4123 Define the SPI bus and chip select. If not defined they will be 0.
4125 - CONFIG_ENV_SPI_MAX_HZ (optional):
4127 Define the SPI max work clock. If not defined then use 1MHz.
4129 - CONFIG_ENV_SPI_MODE (optional):
4131 Define the SPI work mode. If not defined then use SPI_MODE_3.
4133 - CONFIG_ENV_IS_IN_REMOTE:
4135 Define this if you have a remote memory space which you
4136 want to use for the local device's environment.
4141 These two #defines specify the address and size of the
4142 environment area within the remote memory space. The
4143 local device can get the environment from remote memory
4144 space by SRIO or PCIE links.
4146 BE CAREFUL! For some special cases, the local device can not use
4147 "saveenv" command. For example, the local device will get the
4148 environment stored in a remote NOR flash by SRIO or PCIE link,
4149 but it can not erase, write this NOR flash by SRIO or PCIE interface.
4151 - CONFIG_ENV_IS_IN_NAND:
4153 Define this if you have a NAND device which you want to use
4154 for the environment.
4156 - CONFIG_ENV_OFFSET:
4159 These two #defines specify the offset and size of the environment
4160 area within the first NAND device. CONFIG_ENV_OFFSET must be
4161 aligned to an erase block boundary.
4163 - CONFIG_ENV_OFFSET_REDUND (optional):
4165 This setting describes a second storage area of CONFIG_ENV_SIZE
4166 size used to hold a redundant copy of the environment data, so
4167 that there is a valid backup copy in case there is a power failure
4168 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4169 aligned to an erase block boundary.
4171 - CONFIG_ENV_RANGE (optional):
4173 Specifies the length of the region in which the environment
4174 can be written. This should be a multiple of the NAND device's
4175 block size. Specifying a range with more erase blocks than
4176 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4177 the range to be avoided.
4179 - CONFIG_ENV_OFFSET_OOB (optional):
4181 Enables support for dynamically retrieving the offset of the
4182 environment from block zero's out-of-band data. The
4183 "nand env.oob" command can be used to record this offset.
4184 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4185 using CONFIG_ENV_OFFSET_OOB.
4187 - CONFIG_NAND_ENV_DST
4189 Defines address in RAM to which the nand_spl code should copy the
4190 environment. If redundant environment is used, it will be copied to
4191 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4193 - CONFIG_ENV_IS_IN_UBI:
4195 Define this if you have an UBI volume that you want to use for the
4196 environment. This has the benefit of wear-leveling the environment
4197 accesses, which is important on NAND.
4199 - CONFIG_ENV_UBI_PART:
4201 Define this to a string that is the mtd partition containing the UBI.
4203 - CONFIG_ENV_UBI_VOLUME:
4205 Define this to the name of the volume that you want to store the
4208 - CONFIG_ENV_UBI_VOLUME_REDUND:
4210 Define this to the name of another volume to store a second copy of
4211 the environment in. This will enable redundant environments in UBI.
4212 It is assumed that both volumes are in the same MTD partition.
4214 - CONFIG_UBI_SILENCE_MSG
4215 - CONFIG_UBIFS_SILENCE_MSG
4217 You will probably want to define these to avoid a really noisy system
4218 when storing the env in UBI.
4220 - CONFIG_ENV_IS_IN_FAT:
4221 Define this if you want to use the FAT file system for the environment.
4223 - FAT_ENV_INTERFACE:
4225 Define this to a string that is the name of the block device.
4227 - FAT_ENV_DEV_AND_PART:
4229 Define this to a string to specify the partition of the device. It can
4232 "D:P", "D:0", "D", "D:" or "D:auto" (D, P are integers. And P >= 1)
4233 - "D:P": device D partition P. Error occurs if device D has no
4236 - "D" or "D:": device D partition 1 if device D has partition
4237 table, or the whole device D if has no partition
4239 - "D:auto": first partition in device D with bootable flag set.
4240 If none, first valid paratition in device D. If no
4241 partition table then means device D.
4245 It's a string of the FAT file name. This file use to store the
4249 This should be defined. Otherwise it cannot save the envrionment file.
4251 - CONFIG_ENV_IS_IN_MMC:
4253 Define this if you have an MMC device which you want to use for the
4256 - CONFIG_SYS_MMC_ENV_DEV:
4258 Specifies which MMC device the environment is stored in.
4260 - CONFIG_SYS_MMC_ENV_PART (optional):
4262 Specifies which MMC partition the environment is stored in. If not
4263 set, defaults to partition 0, the user area. Common values might be
4264 1 (first MMC boot partition), 2 (second MMC boot partition).
4266 - CONFIG_ENV_OFFSET:
4269 These two #defines specify the offset and size of the environment
4270 area within the specified MMC device.
4272 If offset is positive (the usual case), it is treated as relative to
4273 the start of the MMC partition. If offset is negative, it is treated
4274 as relative to the end of the MMC partition. This can be useful if
4275 your board may be fitted with different MMC devices, which have
4276 different sizes for the MMC partitions, and you always want the
4277 environment placed at the very end of the partition, to leave the
4278 maximum possible space before it, to store other data.
4280 These two values are in units of bytes, but must be aligned to an
4281 MMC sector boundary.
4283 - CONFIG_ENV_OFFSET_REDUND (optional):
4285 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4286 hold a redundant copy of the environment data. This provides a
4287 valid backup copy in case the other copy is corrupted, e.g. due
4288 to a power failure during a "saveenv" operation.
4290 This value may also be positive or negative; this is handled in the
4291 same way as CONFIG_ENV_OFFSET.
4293 This value is also in units of bytes, but must also be aligned to
4294 an MMC sector boundary.
4296 - CONFIG_ENV_SIZE_REDUND (optional):
4298 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4299 set. If this value is set, it must be set to the same value as
4302 - CONFIG_SYS_SPI_INIT_OFFSET
4304 Defines offset to the initial SPI buffer area in DPRAM. The
4305 area is used at an early stage (ROM part) if the environment
4306 is configured to reside in the SPI EEPROM: We need a 520 byte
4307 scratch DPRAM area. It is used between the two initialization
4308 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4309 to be a good choice since it makes it far enough from the
4310 start of the data area as well as from the stack pointer.
4312 Please note that the environment is read-only until the monitor
4313 has been relocated to RAM and a RAM copy of the environment has been
4314 created; also, when using EEPROM you will have to use getenv_f()
4315 until then to read environment variables.
4317 The environment is protected by a CRC32 checksum. Before the monitor
4318 is relocated into RAM, as a result of a bad CRC you will be working
4319 with the compiled-in default environment - *silently*!!! [This is
4320 necessary, because the first environment variable we need is the
4321 "baudrate" setting for the console - if we have a bad CRC, we don't
4322 have any device yet where we could complain.]
4324 Note: once the monitor has been relocated, then it will complain if
4325 the default environment is used; a new CRC is computed as soon as you
4326 use the "saveenv" command to store a valid environment.
4328 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4329 Echo the inverted Ethernet link state to the fault LED.
4331 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4332 also needs to be defined.
4334 - CONFIG_SYS_FAULT_MII_ADDR:
4335 MII address of the PHY to check for the Ethernet link state.
4337 - CONFIG_NS16550_MIN_FUNCTIONS:
4338 Define this if you desire to only have use of the NS16550_init
4339 and NS16550_putc functions for the serial driver located at
4340 drivers/serial/ns16550.c. This option is useful for saving
4341 space for already greatly restricted images, including but not
4342 limited to NAND_SPL configurations.
4344 - CONFIG_DISPLAY_BOARDINFO
4345 Display information about the board that U-Boot is running on
4346 when U-Boot starts up. The board function checkboard() is called
4349 - CONFIG_DISPLAY_BOARDINFO_LATE
4350 Similar to the previous option, but display this information
4351 later, once stdio is running and output goes to the LCD, if
4354 Low Level (hardware related) configuration options:
4355 ---------------------------------------------------
4357 - CONFIG_SYS_CACHELINE_SIZE:
4358 Cache Line Size of the CPU.
4360 - CONFIG_SYS_DEFAULT_IMMR:
4361 Default address of the IMMR after system reset.
4363 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4364 and RPXsuper) to be able to adjust the position of
4365 the IMMR register after a reset.
4367 - CONFIG_SYS_CCSRBAR_DEFAULT:
4368 Default (power-on reset) physical address of CCSR on Freescale
4371 - CONFIG_SYS_CCSRBAR:
4372 Virtual address of CCSR. On a 32-bit build, this is typically
4373 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4375 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4376 for cross-platform code that uses that macro instead.
4378 - CONFIG_SYS_CCSRBAR_PHYS:
4379 Physical address of CCSR. CCSR can be relocated to a new
4380 physical address, if desired. In this case, this macro should
4381 be set to that address. Otherwise, it should be set to the
4382 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4383 is typically relocated on 36-bit builds. It is recommended
4384 that this macro be defined via the _HIGH and _LOW macros:
4386 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4387 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4389 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4390 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4391 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4392 used in assembly code, so it must not contain typecasts or
4393 integer size suffixes (e.g. "ULL").
4395 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4396 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4397 used in assembly code, so it must not contain typecasts or
4398 integer size suffixes (e.g. "ULL").
4400 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4401 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4402 forced to a value that ensures that CCSR is not relocated.
4404 - Floppy Disk Support:
4405 CONFIG_SYS_FDC_DRIVE_NUMBER
4407 the default drive number (default value 0)
4409 CONFIG_SYS_ISA_IO_STRIDE
4411 defines the spacing between FDC chipset registers
4414 CONFIG_SYS_ISA_IO_OFFSET
4416 defines the offset of register from address. It
4417 depends on which part of the data bus is connected to
4418 the FDC chipset. (default value 0)
4420 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4421 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4424 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4425 fdc_hw_init() is called at the beginning of the FDC
4426 setup. fdc_hw_init() must be provided by the board
4427 source code. It is used to make hardware dependant
4431 Most IDE controllers were designed to be connected with PCI
4432 interface. Only few of them were designed for AHB interface.
4433 When software is doing ATA command and data transfer to
4434 IDE devices through IDE-AHB controller, some additional
4435 registers accessing to these kind of IDE-AHB controller
4438 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4439 DO NOT CHANGE unless you know exactly what you're
4440 doing! (11-4) [MPC8xx/82xx systems only]
4442 - CONFIG_SYS_INIT_RAM_ADDR:
4444 Start address of memory area that can be used for
4445 initial data and stack; please note that this must be
4446 writable memory that is working WITHOUT special
4447 initialization, i. e. you CANNOT use normal RAM which
4448 will become available only after programming the
4449 memory controller and running certain initialization
4452 U-Boot uses the following memory types:
4453 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4454 - MPC824X: data cache
4455 - PPC4xx: data cache
4457 - CONFIG_SYS_GBL_DATA_OFFSET:
4459 Offset of the initial data structure in the memory
4460 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4461 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4462 data is located at the end of the available space
4463 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4464 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4465 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4466 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4469 On the MPC824X (or other systems that use the data
4470 cache for initial memory) the address chosen for
4471 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4472 point to an otherwise UNUSED address space between
4473 the top of RAM and the start of the PCI space.
4475 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4477 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4479 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4481 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4483 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4485 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4487 - CONFIG_SYS_OR_TIMING_SDRAM:
4490 - CONFIG_SYS_MAMR_PTA:
4491 periodic timer for refresh
4493 - CONFIG_SYS_DER: Debug Event Register (37-47)
4495 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4496 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4497 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4498 CONFIG_SYS_BR1_PRELIM:
4499 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4501 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4502 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4503 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4504 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4506 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4507 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4508 Machine Mode Register and Memory Periodic Timer
4509 Prescaler definitions (SDRAM timing)
4511 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4512 enable I2C microcode relocation patch (MPC8xx);
4513 define relocation offset in DPRAM [DSP2]
4515 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4516 enable SMC microcode relocation patch (MPC8xx);
4517 define relocation offset in DPRAM [SMC1]
4519 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4520 enable SPI microcode relocation patch (MPC8xx);
4521 define relocation offset in DPRAM [SCC4]
4523 - CONFIG_SYS_USE_OSCCLK:
4524 Use OSCM clock mode on MBX8xx board. Be careful,
4525 wrong setting might damage your board. Read
4526 doc/README.MBX before setting this variable!
4528 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4529 Offset of the bootmode word in DPRAM used by post
4530 (Power On Self Tests). This definition overrides
4531 #define'd default value in commproc.h resp.
4534 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4535 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4536 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4537 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4538 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4539 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4540 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4541 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4542 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4544 - CONFIG_PCI_DISABLE_PCIE:
4545 Disable PCI-Express on systems where it is supported but not
4548 - CONFIG_PCI_ENUM_ONLY
4549 Only scan through and get the devices on the busses.
4550 Don't do any setup work, presumably because someone or
4551 something has already done it, and we don't need to do it
4552 a second time. Useful for platforms that are pre-booted
4553 by coreboot or similar.
4555 - CONFIG_PCI_INDIRECT_BRIDGE:
4556 Enable support for indirect PCI bridges.
4559 Chip has SRIO or not
4562 Board has SRIO 1 port available
4565 Board has SRIO 2 port available
4567 - CONFIG_SRIO_PCIE_BOOT_MASTER
4568 Board can support master function for Boot from SRIO and PCIE
4570 - CONFIG_SYS_SRIOn_MEM_VIRT:
4571 Virtual Address of SRIO port 'n' memory region
4573 - CONFIG_SYS_SRIOn_MEM_PHYS:
4574 Physical Address of SRIO port 'n' memory region
4576 - CONFIG_SYS_SRIOn_MEM_SIZE:
4577 Size of SRIO port 'n' memory region
4579 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4580 Defined to tell the NAND controller that the NAND chip is using
4582 Not all NAND drivers use this symbol.
4583 Example of drivers that use it:
4584 - drivers/mtd/nand/ndfc.c
4585 - drivers/mtd/nand/mxc_nand.c
4587 - CONFIG_SYS_NDFC_EBC0_CFG
4588 Sets the EBC0_CFG register for the NDFC. If not defined
4589 a default value will be used.
4592 Get DDR timing information from an I2C EEPROM. Common
4593 with pluggable memory modules such as SODIMMs
4596 I2C address of the SPD EEPROM
4598 - CONFIG_SYS_SPD_BUS_NUM
4599 If SPD EEPROM is on an I2C bus other than the first
4600 one, specify here. Note that the value must resolve
4601 to something your driver can deal with.
4603 - CONFIG_SYS_DDR_RAW_TIMING
4604 Get DDR timing information from other than SPD. Common with
4605 soldered DDR chips onboard without SPD. DDR raw timing
4606 parameters are extracted from datasheet and hard-coded into
4607 header files or board specific files.
4609 - CONFIG_FSL_DDR_INTERACTIVE
4610 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4612 - CONFIG_SYS_83XX_DDR_USES_CS0
4613 Only for 83xx systems. If specified, then DDR should
4614 be configured using CS0 and CS1 instead of CS2 and CS3.
4616 - CONFIG_ETHER_ON_FEC[12]
4617 Define to enable FEC[12] on a 8xx series processor.
4619 - CONFIG_FEC[12]_PHY
4620 Define to the hardcoded PHY address which corresponds
4621 to the given FEC; i. e.
4622 #define CONFIG_FEC1_PHY 4
4623 means that the PHY with address 4 is connected to FEC1
4625 When set to -1, means to probe for first available.
4627 - CONFIG_FEC[12]_PHY_NORXERR
4628 The PHY does not have a RXERR line (RMII only).
4629 (so program the FEC to ignore it).
4632 Enable RMII mode for all FECs.
4633 Note that this is a global option, we can't
4634 have one FEC in standard MII mode and another in RMII mode.
4636 - CONFIG_CRC32_VERIFY
4637 Add a verify option to the crc32 command.
4640 => crc32 -v <address> <count> <crc32>
4642 Where address/count indicate a memory area
4643 and crc32 is the correct crc32 which the
4647 Add the "loopw" memory command. This only takes effect if
4648 the memory commands are activated globally (CONFIG_CMD_MEM).
4651 Add the "mdc" and "mwc" memory commands. These are cyclic
4656 This command will print 4 bytes (10,11,12,13) each 500 ms.
4658 => mwc.l 100 12345678 10
4659 This command will write 12345678 to address 100 all 10 ms.
4661 This only takes effect if the memory commands are activated
4662 globally (CONFIG_CMD_MEM).
4664 - CONFIG_SKIP_LOWLEVEL_INIT
4665 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4666 low level initializations (like setting up the memory
4667 controller) are omitted and/or U-Boot does not
4668 relocate itself into RAM.
4670 Normally this variable MUST NOT be defined. The only
4671 exception is when U-Boot is loaded (to RAM) by some
4672 other boot loader or by a debugger which performs
4673 these initializations itself.
4676 Modifies the behaviour of start.S when compiling a loader
4677 that is executed before the actual U-Boot. E.g. when
4678 compiling a NAND SPL.
4681 Modifies the behaviour of start.S when compiling a loader
4682 that is executed after the SPL and before the actual U-Boot.
4683 It is loaded by the SPL.
4685 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4686 Only for 85xx systems. If this variable is specified, the section
4687 .resetvec is not kept and the section .bootpg is placed in the
4688 previous 4k of the .text section.
4690 - CONFIG_ARCH_MAP_SYSMEM
4691 Generally U-Boot (and in particular the md command) uses
4692 effective address. It is therefore not necessary to regard
4693 U-Boot address as virtual addresses that need to be translated
4694 to physical addresses. However, sandbox requires this, since
4695 it maintains its own little RAM buffer which contains all
4696 addressable memory. This option causes some memory accesses
4697 to be mapped through map_sysmem() / unmap_sysmem().
4699 - CONFIG_USE_ARCH_MEMCPY
4700 CONFIG_USE_ARCH_MEMSET
4701 If these options are used a optimized version of memcpy/memset will
4702 be used if available. These functions may be faster under some
4703 conditions but may increase the binary size.
4705 - CONFIG_X86_RESET_VECTOR
4706 If defined, the x86 reset vector code is included. This is not
4707 needed when U-Boot is running from Coreboot.
4710 Defines the MPU clock speed (in MHz).
4712 NOTE : currently only supported on AM335x platforms.
4714 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4715 Enables the RTC32K OSC on AM33xx based plattforms
4717 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
4718 Option to disable subpage write in NAND driver
4719 driver that uses this:
4720 drivers/mtd/nand/davinci_nand.c
4722 Freescale QE/FMAN Firmware Support:
4723 -----------------------------------
4725 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4726 loading of "firmware", which is encoded in the QE firmware binary format.
4727 This firmware often needs to be loaded during U-Boot booting, so macros
4728 are used to identify the storage device (NOR flash, SPI, etc) and the address
4731 - CONFIG_SYS_FMAN_FW_ADDR
4732 The address in the storage device where the FMAN microcode is located. The
4733 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4736 - CONFIG_SYS_QE_FW_ADDR
4737 The address in the storage device where the QE microcode is located. The
4738 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4741 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4742 The maximum possible size of the firmware. The firmware binary format
4743 has a field that specifies the actual size of the firmware, but it
4744 might not be possible to read any part of the firmware unless some
4745 local storage is allocated to hold the entire firmware first.
4747 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4748 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4749 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4750 virtual address in NOR flash.
4752 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4753 Specifies that QE/FMAN firmware is located in NAND flash.
4754 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4756 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4757 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4758 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4760 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4761 Specifies that QE/FMAN firmware is located on the primary SPI
4762 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4764 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4765 Specifies that QE/FMAN firmware is located in the remote (master)
4766 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4767 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4768 window->master inbound window->master LAW->the ucode address in
4769 master's memory space.
4771 Freescale Layerscape Management Complex Firmware Support:
4772 ---------------------------------------------------------
4773 The Freescale Layerscape Management Complex (MC) supports the loading of
4775 This firmware often needs to be loaded during U-Boot booting, so macros
4776 are used to identify the storage device (NOR flash, SPI, etc) and the address
4779 - CONFIG_FSL_MC_ENET
4780 Enable the MC driver for Layerscape SoCs.
4782 - CONFIG_SYS_LS_MC_FW_ADDR
4783 The address in the storage device where the firmware is located. The
4784 meaning of this address depends on which CONFIG_SYS_LS_MC_FW_IN_xxx macro
4787 - CONFIG_SYS_LS_MC_FW_LENGTH
4788 The maximum possible size of the firmware. The firmware binary format
4789 has a field that specifies the actual size of the firmware, but it
4790 might not be possible to read any part of the firmware unless some
4791 local storage is allocated to hold the entire firmware first.
4793 - CONFIG_SYS_LS_MC_FW_IN_NOR
4794 Specifies that MC firmware is located in NOR flash, mapped as
4795 normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is the
4796 virtual address in NOR flash.
4798 Building the Software:
4799 ======================
4801 Building U-Boot has been tested in several native build environments
4802 and in many different cross environments. Of course we cannot support
4803 all possibly existing versions of cross development tools in all
4804 (potentially obsolete) versions. In case of tool chain problems we
4805 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4806 which is extensively used to build and test U-Boot.
4808 If you are not using a native environment, it is assumed that you
4809 have GNU cross compiling tools available in your path. In this case,
4810 you must set the environment variable CROSS_COMPILE in your shell.
4811 Note that no changes to the Makefile or any other source files are
4812 necessary. For example using the ELDK on a 4xx CPU, please enter:
4814 $ CROSS_COMPILE=ppc_4xx-
4815 $ export CROSS_COMPILE
4817 Note: If you wish to generate Windows versions of the utilities in
4818 the tools directory you can use the MinGW toolchain
4819 (http://www.mingw.org). Set your HOST tools to the MinGW
4820 toolchain and execute 'make tools'. For example:
4822 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4824 Binaries such as tools/mkimage.exe will be created which can
4825 be executed on computers running Windows.
4827 U-Boot is intended to be simple to build. After installing the
4828 sources you must configure U-Boot for one specific board type. This
4833 where "NAME_config" is the name of one of the existing configu-
4834 rations; see boards.cfg for supported names.
4836 Note: for some board special configuration names may exist; check if
4837 additional information is available from the board vendor; for
4838 instance, the TQM823L systems are available without (standard)
4839 or with LCD support. You can select such additional "features"
4840 when choosing the configuration, i. e.
4843 - will configure for a plain TQM823L, i. e. no LCD support
4845 make TQM823L_LCD_config
4846 - will configure for a TQM823L with U-Boot console on LCD
4851 Finally, type "make all", and you should get some working U-Boot
4852 images ready for download to / installation on your system:
4854 - "u-boot.bin" is a raw binary image
4855 - "u-boot" is an image in ELF binary format
4856 - "u-boot.srec" is in Motorola S-Record format
4858 By default the build is performed locally and the objects are saved
4859 in the source directory. One of the two methods can be used to change
4860 this behavior and build U-Boot to some external directory:
4862 1. Add O= to the make command line invocations:
4864 make O=/tmp/build distclean
4865 make O=/tmp/build NAME_config
4866 make O=/tmp/build all
4868 2. Set environment variable BUILD_DIR to point to the desired location:
4870 export BUILD_DIR=/tmp/build
4875 Note that the command line "O=" setting overrides the BUILD_DIR environment
4879 Please be aware that the Makefiles assume you are using GNU make, so
4880 for instance on NetBSD you might need to use "gmake" instead of
4884 If the system board that you have is not listed, then you will need
4885 to port U-Boot to your hardware platform. To do this, follow these
4888 1. Add a new configuration option for your board to the toplevel
4889 "boards.cfg" file, using the existing entries as examples.
4890 Follow the instructions there to keep the boards in order.
4891 2. Create a new directory to hold your board specific code. Add any
4892 files you need. In your board directory, you will need at least
4893 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4894 3. Create a new configuration file "include/configs/<board>.h" for
4896 3. If you're porting U-Boot to a new CPU, then also create a new
4897 directory to hold your CPU specific code. Add any files you need.
4898 4. Run "make <board>_config" with your new name.
4899 5. Type "make", and you should get a working "u-boot.srec" file
4900 to be installed on your target system.
4901 6. Debug and solve any problems that might arise.
4902 [Of course, this last step is much harder than it sounds.]
4905 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4906 ==============================================================
4908 If you have modified U-Boot sources (for instance added a new board
4909 or support for new devices, a new CPU, etc.) you are expected to
4910 provide feedback to the other developers. The feedback normally takes
4911 the form of a "patch", i. e. a context diff against a certain (latest
4912 official or latest in the git repository) version of U-Boot sources.
4914 But before you submit such a patch, please verify that your modifi-
4915 cation did not break existing code. At least make sure that *ALL* of
4916 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4917 just run the "MAKEALL" script, which will configure and build U-Boot
4918 for ALL supported system. Be warned, this will take a while. You can
4919 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4920 environment variable to the script, i. e. to use the ELDK cross tools
4923 CROSS_COMPILE=ppc_8xx- MAKEALL
4925 or to build on a native PowerPC system you can type
4927 CROSS_COMPILE=' ' MAKEALL
4929 When using the MAKEALL script, the default behaviour is to build
4930 U-Boot in the source directory. This location can be changed by
4931 setting the BUILD_DIR environment variable. Also, for each target
4932 built, the MAKEALL script saves two log files (<target>.ERR and
4933 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4934 location can be changed by setting the MAKEALL_LOGDIR environment
4935 variable. For example:
4937 export BUILD_DIR=/tmp/build
4938 export MAKEALL_LOGDIR=/tmp/log
4939 CROSS_COMPILE=ppc_8xx- MAKEALL
4941 With the above settings build objects are saved in the /tmp/build,
4942 log files are saved in the /tmp/log and the source tree remains clean
4943 during the whole build process.
4946 See also "U-Boot Porting Guide" below.
4949 Monitor Commands - Overview:
4950 ============================
4952 go - start application at address 'addr'
4953 run - run commands in an environment variable
4954 bootm - boot application image from memory
4955 bootp - boot image via network using BootP/TFTP protocol
4956 bootz - boot zImage from memory
4957 tftpboot- boot image via network using TFTP protocol
4958 and env variables "ipaddr" and "serverip"
4959 (and eventually "gatewayip")
4960 tftpput - upload a file via network using TFTP protocol
4961 rarpboot- boot image via network using RARP/TFTP protocol
4962 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4963 loads - load S-Record file over serial line
4964 loadb - load binary file over serial line (kermit mode)
4966 mm - memory modify (auto-incrementing)
4967 nm - memory modify (constant address)
4968 mw - memory write (fill)
4970 cmp - memory compare
4971 crc32 - checksum calculation
4972 i2c - I2C sub-system
4973 sspi - SPI utility commands
4974 base - print or set address offset
4975 printenv- print environment variables
4976 setenv - set environment variables
4977 saveenv - save environment variables to persistent storage
4978 protect - enable or disable FLASH write protection
4979 erase - erase FLASH memory
4980 flinfo - print FLASH memory information
4981 nand - NAND memory operations (see doc/README.nand)
4982 bdinfo - print Board Info structure
4983 iminfo - print header information for application image
4984 coninfo - print console devices and informations
4985 ide - IDE sub-system
4986 loop - infinite loop on address range
4987 loopw - infinite write loop on address range
4988 mtest - simple RAM test
4989 icache - enable or disable instruction cache
4990 dcache - enable or disable data cache
4991 reset - Perform RESET of the CPU
4992 echo - echo args to console
4993 version - print monitor version
4994 help - print online help
4995 ? - alias for 'help'
4998 Monitor Commands - Detailed Description:
4999 ========================================
5003 For now: just type "help <command>".
5006 Environment Variables:
5007 ======================
5009 U-Boot supports user configuration using Environment Variables which
5010 can be made persistent by saving to Flash memory.
5012 Environment Variables are set using "setenv", printed using
5013 "printenv", and saved to Flash using "saveenv". Using "setenv"
5014 without a value can be used to delete a variable from the
5015 environment. As long as you don't save the environment you are
5016 working with an in-memory copy. In case the Flash area containing the
5017 environment is erased by accident, a default environment is provided.
5019 Some configuration options can be set using Environment Variables.
5021 List of environment variables (most likely not complete):
5023 baudrate - see CONFIG_BAUDRATE
5025 bootdelay - see CONFIG_BOOTDELAY
5027 bootcmd - see CONFIG_BOOTCOMMAND
5029 bootargs - Boot arguments when booting an RTOS image
5031 bootfile - Name of the image to load with TFTP
5033 bootm_low - Memory range available for image processing in the bootm
5034 command can be restricted. This variable is given as
5035 a hexadecimal number and defines lowest address allowed
5036 for use by the bootm command. See also "bootm_size"
5037 environment variable. Address defined by "bootm_low" is
5038 also the base of the initial memory mapping for the Linux
5039 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
5042 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
5043 This variable is given as a hexadecimal number and it
5044 defines the size of the memory region starting at base
5045 address bootm_low that is accessible by the Linux kernel
5046 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
5047 as the default value if it is defined, and bootm_size is
5050 bootm_size - Memory range available for image processing in the bootm
5051 command can be restricted. This variable is given as
5052 a hexadecimal number and defines the size of the region
5053 allowed for use by the bootm command. See also "bootm_low"
5054 environment variable.
5056 updatefile - Location of the software update file on a TFTP server, used
5057 by the automatic software update feature. Please refer to
5058 documentation in doc/README.update for more details.
5060 autoload - if set to "no" (any string beginning with 'n'),
5061 "bootp" will just load perform a lookup of the
5062 configuration from the BOOTP server, but not try to
5063 load any image using TFTP
5065 autostart - if set to "yes", an image loaded using the "bootp",
5066 "rarpboot", "tftpboot" or "diskboot" commands will
5067 be automatically started (by internally calling
5070 If set to "no", a standalone image passed to the
5071 "bootm" command will be copied to the load address
5072 (and eventually uncompressed), but NOT be started.
5073 This can be used to load and uncompress arbitrary
5076 fdt_high - if set this restricts the maximum address that the
5077 flattened device tree will be copied into upon boot.
5078 For example, if you have a system with 1 GB memory
5079 at physical address 0x10000000, while Linux kernel
5080 only recognizes the first 704 MB as low memory, you
5081 may need to set fdt_high as 0x3C000000 to have the
5082 device tree blob be copied to the maximum address
5083 of the 704 MB low memory, so that Linux kernel can
5084 access it during the boot procedure.
5086 If this is set to the special value 0xFFFFFFFF then
5087 the fdt will not be copied at all on boot. For this
5088 to work it must reside in writable memory, have
5089 sufficient padding on the end of it for u-boot to
5090 add the information it needs into it, and the memory
5091 must be accessible by the kernel.
5093 fdtcontroladdr- if set this is the address of the control flattened
5094 device tree used by U-Boot when CONFIG_OF_CONTROL is
5097 i2cfast - (PPC405GP|PPC405EP only)
5098 if set to 'y' configures Linux I2C driver for fast
5099 mode (400kHZ). This environment variable is used in
5100 initialization code. So, for changes to be effective
5101 it must be saved and board must be reset.
5103 initrd_high - restrict positioning of initrd images:
5104 If this variable is not set, initrd images will be
5105 copied to the highest possible address in RAM; this
5106 is usually what you want since it allows for
5107 maximum initrd size. If for some reason you want to
5108 make sure that the initrd image is loaded below the
5109 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
5110 variable to a value of "no" or "off" or "0".
5111 Alternatively, you can set it to a maximum upper
5112 address to use (U-Boot will still check that it
5113 does not overwrite the U-Boot stack and data).
5115 For instance, when you have a system with 16 MB
5116 RAM, and want to reserve 4 MB from use by Linux,
5117 you can do this by adding "mem=12M" to the value of
5118 the "bootargs" variable. However, now you must make
5119 sure that the initrd image is placed in the first
5120 12 MB as well - this can be done with
5122 setenv initrd_high 00c00000
5124 If you set initrd_high to 0xFFFFFFFF, this is an
5125 indication to U-Boot that all addresses are legal
5126 for the Linux kernel, including addresses in flash
5127 memory. In this case U-Boot will NOT COPY the
5128 ramdisk at all. This may be useful to reduce the
5129 boot time on your system, but requires that this
5130 feature is supported by your Linux kernel.
5132 ipaddr - IP address; needed for tftpboot command
5134 loadaddr - Default load address for commands like "bootp",
5135 "rarpboot", "tftpboot", "loadb" or "diskboot"
5137 loads_echo - see CONFIG_LOADS_ECHO
5139 serverip - TFTP server IP address; needed for tftpboot command
5141 bootretry - see CONFIG_BOOT_RETRY_TIME
5143 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
5145 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
5147 ethprime - controls which interface is used first.
5149 ethact - controls which interface is currently active.
5150 For example you can do the following
5152 => setenv ethact FEC
5153 => ping 192.168.0.1 # traffic sent on FEC
5154 => setenv ethact SCC
5155 => ping 10.0.0.1 # traffic sent on SCC
5157 ethrotate - When set to "no" U-Boot does not go through all
5158 available network interfaces.
5159 It just stays at the currently selected interface.
5161 netretry - When set to "no" each network operation will
5162 either succeed or fail without retrying.
5163 When set to "once" the network operation will
5164 fail when all the available network interfaces
5165 are tried once without success.
5166 Useful on scripts which control the retry operation
5169 npe_ucode - set load address for the NPE microcode
5171 silent_linux - If set then linux will be told to boot silently, by
5172 changing the console to be empty. If "yes" it will be
5173 made silent. If "no" it will not be made silent. If
5174 unset, then it will be made silent if the U-Boot console
5177 tftpsrcport - If this is set, the value is used for TFTP's
5180 tftpdstport - If this is set, the value is used for TFTP's UDP
5181 destination port instead of the Well Know Port 69.
5183 tftpblocksize - Block size to use for TFTP transfers; if not set,
5184 we use the TFTP server's default block size
5186 tftptimeout - Retransmission timeout for TFTP packets (in milli-
5187 seconds, minimum value is 1000 = 1 second). Defines
5188 when a packet is considered to be lost so it has to
5189 be retransmitted. The default is 5000 = 5 seconds.
5190 Lowering this value may make downloads succeed
5191 faster in networks with high packet loss rates or
5192 with unreliable TFTP servers.
5194 vlan - When set to a value < 4095 the traffic over
5195 Ethernet is encapsulated/received over 802.1q
5198 The following image location variables contain the location of images
5199 used in booting. The "Image" column gives the role of the image and is
5200 not an environment variable name. The other columns are environment
5201 variable names. "File Name" gives the name of the file on a TFTP
5202 server, "RAM Address" gives the location in RAM the image will be
5203 loaded to, and "Flash Location" gives the image's address in NOR
5204 flash or offset in NAND flash.
5206 *Note* - these variables don't have to be defined for all boards, some
5207 boards currenlty use other variables for these purposes, and some
5208 boards use these variables for other purposes.
5210 Image File Name RAM Address Flash Location
5211 ----- --------- ----------- --------------
5212 u-boot u-boot u-boot_addr_r u-boot_addr
5213 Linux kernel bootfile kernel_addr_r kernel_addr
5214 device tree blob fdtfile fdt_addr_r fdt_addr
5215 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
5217 The following environment variables may be used and automatically
5218 updated by the network boot commands ("bootp" and "rarpboot"),
5219 depending the information provided by your boot server:
5221 bootfile - see above
5222 dnsip - IP address of your Domain Name Server
5223 dnsip2 - IP address of your secondary Domain Name Server
5224 gatewayip - IP address of the Gateway (Router) to use
5225 hostname - Target hostname
5227 netmask - Subnet Mask
5228 rootpath - Pathname of the root filesystem on the NFS server
5229 serverip - see above
5232 There are two special Environment Variables:
5234 serial# - contains hardware identification information such
5235 as type string and/or serial number
5236 ethaddr - Ethernet address
5238 These variables can be set only once (usually during manufacturing of
5239 the board). U-Boot refuses to delete or overwrite these variables
5240 once they have been set once.
5243 Further special Environment Variables:
5245 ver - Contains the U-Boot version string as printed
5246 with the "version" command. This variable is
5247 readonly (see CONFIG_VERSION_VARIABLE).
5250 Please note that changes to some configuration parameters may take
5251 only effect after the next boot (yes, that's just like Windoze :-).
5254 Callback functions for environment variables:
5255 ---------------------------------------------
5257 For some environment variables, the behavior of u-boot needs to change
5258 when their values are changed. This functionailty allows functions to
5259 be associated with arbitrary variables. On creation, overwrite, or
5260 deletion, the callback will provide the opportunity for some side
5261 effect to happen or for the change to be rejected.
5263 The callbacks are named and associated with a function using the
5264 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5266 These callbacks are associated with variables in one of two ways. The
5267 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5268 in the board configuration to a string that defines a list of
5269 associations. The list must be in the following format:
5271 entry = variable_name[:callback_name]
5274 If the callback name is not specified, then the callback is deleted.
5275 Spaces are also allowed anywhere in the list.
5277 Callbacks can also be associated by defining the ".callbacks" variable
5278 with the same list format above. Any association in ".callbacks" will
5279 override any association in the static list. You can define
5280 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5281 ".callbacks" envirnoment variable in the default or embedded environment.
5284 Command Line Parsing:
5285 =====================
5287 There are two different command line parsers available with U-Boot:
5288 the old "simple" one, and the much more powerful "hush" shell:
5290 Old, simple command line parser:
5291 --------------------------------
5293 - supports environment variables (through setenv / saveenv commands)
5294 - several commands on one line, separated by ';'
5295 - variable substitution using "... ${name} ..." syntax
5296 - special characters ('$', ';') can be escaped by prefixing with '\',
5298 setenv bootcmd bootm \${address}
5299 - You can also escape text by enclosing in single apostrophes, for example:
5300 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5305 - similar to Bourne shell, with control structures like
5306 if...then...else...fi, for...do...done; while...do...done,
5307 until...do...done, ...
5308 - supports environment ("global") variables (through setenv / saveenv
5309 commands) and local shell variables (through standard shell syntax
5310 "name=value"); only environment variables can be used with "run"
5316 (1) If a command line (or an environment variable executed by a "run"
5317 command) contains several commands separated by semicolon, and
5318 one of these commands fails, then the remaining commands will be
5321 (2) If you execute several variables with one call to run (i. e.
5322 calling run with a list of variables as arguments), any failing
5323 command will cause "run" to terminate, i. e. the remaining
5324 variables are not executed.
5326 Note for Redundant Ethernet Interfaces:
5327 =======================================
5329 Some boards come with redundant Ethernet interfaces; U-Boot supports
5330 such configurations and is capable of automatic selection of a
5331 "working" interface when needed. MAC assignment works as follows:
5333 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5334 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5335 "eth1addr" (=>eth1), "eth2addr", ...
5337 If the network interface stores some valid MAC address (for instance
5338 in SROM), this is used as default address if there is NO correspon-
5339 ding setting in the environment; if the corresponding environment
5340 variable is set, this overrides the settings in the card; that means:
5342 o If the SROM has a valid MAC address, and there is no address in the
5343 environment, the SROM's address is used.
5345 o If there is no valid address in the SROM, and a definition in the
5346 environment exists, then the value from the environment variable is
5349 o If both the SROM and the environment contain a MAC address, and
5350 both addresses are the same, this MAC address is used.
5352 o If both the SROM and the environment contain a MAC address, and the
5353 addresses differ, the value from the environment is used and a
5356 o If neither SROM nor the environment contain a MAC address, an error
5359 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5360 will be programmed into hardware as part of the initialization process. This
5361 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5362 The naming convention is as follows:
5363 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5368 U-Boot is capable of booting (and performing other auxiliary operations on)
5369 images in two formats:
5371 New uImage format (FIT)
5372 -----------------------
5374 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5375 to Flattened Device Tree). It allows the use of images with multiple
5376 components (several kernels, ramdisks, etc.), with contents protected by
5377 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5383 Old image format is based on binary files which can be basically anything,
5384 preceded by a special header; see the definitions in include/image.h for
5385 details; basically, the header defines the following image properties:
5387 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5388 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5389 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5390 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5392 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5393 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5394 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5395 * Compression Type (uncompressed, gzip, bzip2)
5401 The header is marked by a special Magic Number, and both the header
5402 and the data portions of the image are secured against corruption by
5409 Although U-Boot should support any OS or standalone application
5410 easily, the main focus has always been on Linux during the design of
5413 U-Boot includes many features that so far have been part of some
5414 special "boot loader" code within the Linux kernel. Also, any
5415 "initrd" images to be used are no longer part of one big Linux image;
5416 instead, kernel and "initrd" are separate images. This implementation
5417 serves several purposes:
5419 - the same features can be used for other OS or standalone
5420 applications (for instance: using compressed images to reduce the
5421 Flash memory footprint)
5423 - it becomes much easier to port new Linux kernel versions because
5424 lots of low-level, hardware dependent stuff are done by U-Boot
5426 - the same Linux kernel image can now be used with different "initrd"
5427 images; of course this also means that different kernel images can
5428 be run with the same "initrd". This makes testing easier (you don't
5429 have to build a new "zImage.initrd" Linux image when you just
5430 change a file in your "initrd"). Also, a field-upgrade of the
5431 software is easier now.
5437 Porting Linux to U-Boot based systems:
5438 ---------------------------------------
5440 U-Boot cannot save you from doing all the necessary modifications to
5441 configure the Linux device drivers for use with your target hardware
5442 (no, we don't intend to provide a full virtual machine interface to
5445 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5447 Just make sure your machine specific header file (for instance
5448 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5449 Information structure as we define in include/asm-<arch>/u-boot.h,
5450 and make sure that your definition of IMAP_ADDR uses the same value
5451 as your U-Boot configuration in CONFIG_SYS_IMMR.
5453 Note that U-Boot now has a driver model, a unified model for drivers.
5454 If you are adding a new driver, plumb it into driver model. If there
5455 is no uclass available, you are encouraged to create one. See
5459 Configuring the Linux kernel:
5460 -----------------------------
5462 No specific requirements for U-Boot. Make sure you have some root
5463 device (initial ramdisk, NFS) for your target system.
5466 Building a Linux Image:
5467 -----------------------
5469 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5470 not used. If you use recent kernel source, a new build target
5471 "uImage" will exist which automatically builds an image usable by
5472 U-Boot. Most older kernels also have support for a "pImage" target,
5473 which was introduced for our predecessor project PPCBoot and uses a
5474 100% compatible format.
5483 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5484 encapsulate a compressed Linux kernel image with header information,
5485 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5487 * build a standard "vmlinux" kernel image (in ELF binary format):
5489 * convert the kernel into a raw binary image:
5491 ${CROSS_COMPILE}-objcopy -O binary \
5492 -R .note -R .comment \
5493 -S vmlinux linux.bin
5495 * compress the binary image:
5499 * package compressed binary image for U-Boot:
5501 mkimage -A ppc -O linux -T kernel -C gzip \
5502 -a 0 -e 0 -n "Linux Kernel Image" \
5503 -d linux.bin.gz uImage
5506 The "mkimage" tool can also be used to create ramdisk images for use
5507 with U-Boot, either separated from the Linux kernel image, or
5508 combined into one file. "mkimage" encapsulates the images with a 64
5509 byte header containing information about target architecture,
5510 operating system, image type, compression method, entry points, time
5511 stamp, CRC32 checksums, etc.
5513 "mkimage" can be called in two ways: to verify existing images and
5514 print the header information, or to build new images.
5516 In the first form (with "-l" option) mkimage lists the information
5517 contained in the header of an existing U-Boot image; this includes
5518 checksum verification:
5520 tools/mkimage -l image
5521 -l ==> list image header information
5523 The second form (with "-d" option) is used to build a U-Boot image
5524 from a "data file" which is used as image payload:
5526 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5527 -n name -d data_file image
5528 -A ==> set architecture to 'arch'
5529 -O ==> set operating system to 'os'
5530 -T ==> set image type to 'type'
5531 -C ==> set compression type 'comp'
5532 -a ==> set load address to 'addr' (hex)
5533 -e ==> set entry point to 'ep' (hex)
5534 -n ==> set image name to 'name'
5535 -d ==> use image data from 'datafile'
5537 Right now, all Linux kernels for PowerPC systems use the same load
5538 address (0x00000000), but the entry point address depends on the
5541 - 2.2.x kernels have the entry point at 0x0000000C,
5542 - 2.3.x and later kernels have the entry point at 0x00000000.
5544 So a typical call to build a U-Boot image would read:
5546 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5547 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5548 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5549 > examples/uImage.TQM850L
5550 Image Name: 2.4.4 kernel for TQM850L
5551 Created: Wed Jul 19 02:34:59 2000
5552 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5553 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5554 Load Address: 0x00000000
5555 Entry Point: 0x00000000
5557 To verify the contents of the image (or check for corruption):
5559 -> tools/mkimage -l examples/uImage.TQM850L
5560 Image Name: 2.4.4 kernel for TQM850L
5561 Created: Wed Jul 19 02:34:59 2000
5562 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5563 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5564 Load Address: 0x00000000
5565 Entry Point: 0x00000000
5567 NOTE: for embedded systems where boot time is critical you can trade
5568 speed for memory and install an UNCOMPRESSED image instead: this
5569 needs more space in Flash, but boots much faster since it does not
5570 need to be uncompressed:
5572 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5573 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5574 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5575 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5576 > examples/uImage.TQM850L-uncompressed
5577 Image Name: 2.4.4 kernel for TQM850L
5578 Created: Wed Jul 19 02:34:59 2000
5579 Image Type: PowerPC Linux Kernel Image (uncompressed)
5580 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5581 Load Address: 0x00000000
5582 Entry Point: 0x00000000
5585 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5586 when your kernel is intended to use an initial ramdisk:
5588 -> tools/mkimage -n 'Simple Ramdisk Image' \
5589 > -A ppc -O linux -T ramdisk -C gzip \
5590 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5591 Image Name: Simple Ramdisk Image
5592 Created: Wed Jan 12 14:01:50 2000
5593 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5594 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5595 Load Address: 0x00000000
5596 Entry Point: 0x00000000
5598 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5599 option performs the converse operation of the mkimage's second form (the "-d"
5600 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5603 tools/dumpimage -i image -p position data_file
5604 -i ==> extract from the 'image' a specific 'data_file', \
5605 indexed by 'position'
5608 Installing a Linux Image:
5609 -------------------------
5611 To downloading a U-Boot image over the serial (console) interface,
5612 you must convert the image to S-Record format:
5614 objcopy -I binary -O srec examples/image examples/image.srec
5616 The 'objcopy' does not understand the information in the U-Boot
5617 image header, so the resulting S-Record file will be relative to
5618 address 0x00000000. To load it to a given address, you need to
5619 specify the target address as 'offset' parameter with the 'loads'
5622 Example: install the image to address 0x40100000 (which on the
5623 TQM8xxL is in the first Flash bank):
5625 => erase 40100000 401FFFFF
5631 ## Ready for S-Record download ...
5632 ~>examples/image.srec
5633 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5635 15989 15990 15991 15992
5636 [file transfer complete]
5638 ## Start Addr = 0x00000000
5641 You can check the success of the download using the 'iminfo' command;
5642 this includes a checksum verification so you can be sure no data
5643 corruption happened:
5647 ## Checking Image at 40100000 ...
5648 Image Name: 2.2.13 for initrd on TQM850L
5649 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5650 Data Size: 335725 Bytes = 327 kB = 0 MB
5651 Load Address: 00000000
5652 Entry Point: 0000000c
5653 Verifying Checksum ... OK
5659 The "bootm" command is used to boot an application that is stored in
5660 memory (RAM or Flash). In case of a Linux kernel image, the contents
5661 of the "bootargs" environment variable is passed to the kernel as
5662 parameters. You can check and modify this variable using the
5663 "printenv" and "setenv" commands:
5666 => printenv bootargs
5667 bootargs=root=/dev/ram
5669 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5671 => printenv bootargs
5672 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5675 ## Booting Linux kernel at 40020000 ...
5676 Image Name: 2.2.13 for NFS on TQM850L
5677 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5678 Data Size: 381681 Bytes = 372 kB = 0 MB
5679 Load Address: 00000000
5680 Entry Point: 0000000c
5681 Verifying Checksum ... OK
5682 Uncompressing Kernel Image ... OK
5683 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
5684 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5685 time_init: decrementer frequency = 187500000/60
5686 Calibrating delay loop... 49.77 BogoMIPS
5687 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5690 If you want to boot a Linux kernel with initial RAM disk, you pass
5691 the memory addresses of both the kernel and the initrd image (PPBCOOT
5692 format!) to the "bootm" command:
5694 => imi 40100000 40200000
5696 ## Checking Image at 40100000 ...
5697 Image Name: 2.2.13 for initrd on TQM850L
5698 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5699 Data Size: 335725 Bytes = 327 kB = 0 MB
5700 Load Address: 00000000
5701 Entry Point: 0000000c
5702 Verifying Checksum ... OK
5704 ## Checking Image at 40200000 ...
5705 Image Name: Simple Ramdisk Image
5706 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5707 Data Size: 566530 Bytes = 553 kB = 0 MB
5708 Load Address: 00000000
5709 Entry Point: 00000000
5710 Verifying Checksum ... OK
5712 => bootm 40100000 40200000
5713 ## Booting Linux kernel at 40100000 ...
5714 Image Name: 2.2.13 for initrd on TQM850L
5715 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5716 Data Size: 335725 Bytes = 327 kB = 0 MB
5717 Load Address: 00000000
5718 Entry Point: 0000000c
5719 Verifying Checksum ... OK
5720 Uncompressing Kernel Image ... OK
5721 ## Loading RAMDisk Image at 40200000 ...
5722 Image Name: Simple Ramdisk Image
5723 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5724 Data Size: 566530 Bytes = 553 kB = 0 MB
5725 Load Address: 00000000
5726 Entry Point: 00000000
5727 Verifying Checksum ... OK
5728 Loading Ramdisk ... OK
5729 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
5730 Boot arguments: root=/dev/ram
5731 time_init: decrementer frequency = 187500000/60
5732 Calibrating delay loop... 49.77 BogoMIPS
5734 RAMDISK: Compressed image found at block 0
5735 VFS: Mounted root (ext2 filesystem).
5739 Boot Linux and pass a flat device tree:
5742 First, U-Boot must be compiled with the appropriate defines. See the section
5743 titled "Linux Kernel Interface" above for a more in depth explanation. The
5744 following is an example of how to start a kernel and pass an updated
5750 oft=oftrees/mpc8540ads.dtb
5751 => tftp $oftaddr $oft
5752 Speed: 1000, full duplex
5754 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5755 Filename 'oftrees/mpc8540ads.dtb'.
5756 Load address: 0x300000
5759 Bytes transferred = 4106 (100a hex)
5760 => tftp $loadaddr $bootfile
5761 Speed: 1000, full duplex
5763 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5765 Load address: 0x200000
5766 Loading:############
5768 Bytes transferred = 1029407 (fb51f hex)
5773 => bootm $loadaddr - $oftaddr
5774 ## Booting image at 00200000 ...
5775 Image Name: Linux-2.6.17-dirty
5776 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5777 Data Size: 1029343 Bytes = 1005.2 kB
5778 Load Address: 00000000
5779 Entry Point: 00000000
5780 Verifying Checksum ... OK
5781 Uncompressing Kernel Image ... OK
5782 Booting using flat device tree at 0x300000
5783 Using MPC85xx ADS machine description
5784 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5788 More About U-Boot Image Types:
5789 ------------------------------
5791 U-Boot supports the following image types:
5793 "Standalone Programs" are directly runnable in the environment
5794 provided by U-Boot; it is expected that (if they behave
5795 well) you can continue to work in U-Boot after return from
5796 the Standalone Program.
5797 "OS Kernel Images" are usually images of some Embedded OS which
5798 will take over control completely. Usually these programs
5799 will install their own set of exception handlers, device
5800 drivers, set up the MMU, etc. - this means, that you cannot
5801 expect to re-enter U-Boot except by resetting the CPU.
5802 "RAMDisk Images" are more or less just data blocks, and their
5803 parameters (address, size) are passed to an OS kernel that is
5805 "Multi-File Images" contain several images, typically an OS
5806 (Linux) kernel image and one or more data images like
5807 RAMDisks. This construct is useful for instance when you want
5808 to boot over the network using BOOTP etc., where the boot
5809 server provides just a single image file, but you want to get
5810 for instance an OS kernel and a RAMDisk image.
5812 "Multi-File Images" start with a list of image sizes, each
5813 image size (in bytes) specified by an "uint32_t" in network
5814 byte order. This list is terminated by an "(uint32_t)0".
5815 Immediately after the terminating 0 follow the images, one by
5816 one, all aligned on "uint32_t" boundaries (size rounded up to
5817 a multiple of 4 bytes).
5819 "Firmware Images" are binary images containing firmware (like
5820 U-Boot or FPGA images) which usually will be programmed to
5823 "Script files" are command sequences that will be executed by
5824 U-Boot's command interpreter; this feature is especially
5825 useful when you configure U-Boot to use a real shell (hush)
5826 as command interpreter.
5828 Booting the Linux zImage:
5829 -------------------------
5831 On some platforms, it's possible to boot Linux zImage. This is done
5832 using the "bootz" command. The syntax of "bootz" command is the same
5833 as the syntax of "bootm" command.
5835 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5836 kernel with raw initrd images. The syntax is slightly different, the
5837 address of the initrd must be augmented by it's size, in the following
5838 format: "<initrd addres>:<initrd size>".
5844 One of the features of U-Boot is that you can dynamically load and
5845 run "standalone" applications, which can use some resources of
5846 U-Boot like console I/O functions or interrupt services.
5848 Two simple examples are included with the sources:
5853 'examples/hello_world.c' contains a small "Hello World" Demo
5854 application; it is automatically compiled when you build U-Boot.
5855 It's configured to run at address 0x00040004, so you can play with it
5859 ## Ready for S-Record download ...
5860 ~>examples/hello_world.srec
5861 1 2 3 4 5 6 7 8 9 10 11 ...
5862 [file transfer complete]
5864 ## Start Addr = 0x00040004
5866 => go 40004 Hello World! This is a test.
5867 ## Starting application at 0x00040004 ...
5878 Hit any key to exit ...
5880 ## Application terminated, rc = 0x0
5882 Another example, which demonstrates how to register a CPM interrupt
5883 handler with the U-Boot code, can be found in 'examples/timer.c'.
5884 Here, a CPM timer is set up to generate an interrupt every second.
5885 The interrupt service routine is trivial, just printing a '.'
5886 character, but this is just a demo program. The application can be
5887 controlled by the following keys:
5889 ? - print current values og the CPM Timer registers
5890 b - enable interrupts and start timer
5891 e - stop timer and disable interrupts
5892 q - quit application
5895 ## Ready for S-Record download ...
5896 ~>examples/timer.srec
5897 1 2 3 4 5 6 7 8 9 10 11 ...
5898 [file transfer complete]
5900 ## Start Addr = 0x00040004
5903 ## Starting application at 0x00040004 ...
5906 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5909 [q, b, e, ?] Set interval 1000000 us
5912 [q, b, e, ?] ........
5913 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5916 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5919 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5922 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5924 [q, b, e, ?] ...Stopping timer
5926 [q, b, e, ?] ## Application terminated, rc = 0x0
5932 Over time, many people have reported problems when trying to use the
5933 "minicom" terminal emulation program for serial download. I (wd)
5934 consider minicom to be broken, and recommend not to use it. Under
5935 Unix, I recommend to use C-Kermit for general purpose use (and
5936 especially for kermit binary protocol download ("loadb" command), and
5937 use "cu" for S-Record download ("loads" command). See
5938 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5939 for help with kermit.
5942 Nevertheless, if you absolutely want to use it try adding this
5943 configuration to your "File transfer protocols" section:
5945 Name Program Name U/D FullScr IO-Red. Multi
5946 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5947 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5953 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5954 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5956 Building requires a cross environment; it is known to work on
5957 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5958 need gmake since the Makefiles are not compatible with BSD make).
5959 Note that the cross-powerpc package does not install include files;
5960 attempting to build U-Boot will fail because <machine/ansi.h> is
5961 missing. This file has to be installed and patched manually:
5963 # cd /usr/pkg/cross/powerpc-netbsd/include
5965 # ln -s powerpc machine
5966 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5967 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5969 Native builds *don't* work due to incompatibilities between native
5970 and U-Boot include files.
5972 Booting assumes that (the first part of) the image booted is a
5973 stage-2 loader which in turn loads and then invokes the kernel
5974 proper. Loader sources will eventually appear in the NetBSD source
5975 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5976 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5979 Implementation Internals:
5980 =========================
5982 The following is not intended to be a complete description of every
5983 implementation detail. However, it should help to understand the
5984 inner workings of U-Boot and make it easier to port it to custom
5988 Initial Stack, Global Data:
5989 ---------------------------
5991 The implementation of U-Boot is complicated by the fact that U-Boot
5992 starts running out of ROM (flash memory), usually without access to
5993 system RAM (because the memory controller is not initialized yet).
5994 This means that we don't have writable Data or BSS segments, and BSS
5995 is not initialized as zero. To be able to get a C environment working
5996 at all, we have to allocate at least a minimal stack. Implementation
5997 options for this are defined and restricted by the CPU used: Some CPU
5998 models provide on-chip memory (like the IMMR area on MPC8xx and
5999 MPC826x processors), on others (parts of) the data cache can be
6000 locked as (mis-) used as memory, etc.
6002 Chris Hallinan posted a good summary of these issues to the
6003 U-Boot mailing list:
6005 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
6006 From: "Chris Hallinan" <clh@net1plus.com>
6007 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
6010 Correct me if I'm wrong, folks, but the way I understand it
6011 is this: Using DCACHE as initial RAM for Stack, etc, does not
6012 require any physical RAM backing up the cache. The cleverness
6013 is that the cache is being used as a temporary supply of
6014 necessary storage before the SDRAM controller is setup. It's
6015 beyond the scope of this list to explain the details, but you
6016 can see how this works by studying the cache architecture and
6017 operation in the architecture and processor-specific manuals.
6019 OCM is On Chip Memory, which I believe the 405GP has 4K. It
6020 is another option for the system designer to use as an
6021 initial stack/RAM area prior to SDRAM being available. Either
6022 option should work for you. Using CS 4 should be fine if your
6023 board designers haven't used it for something that would
6024 cause you grief during the initial boot! It is frequently not
6027 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
6028 with your processor/board/system design. The default value
6029 you will find in any recent u-boot distribution in
6030 walnut.h should work for you. I'd set it to a value larger
6031 than your SDRAM module. If you have a 64MB SDRAM module, set
6032 it above 400_0000. Just make sure your board has no resources
6033 that are supposed to respond to that address! That code in
6034 start.S has been around a while and should work as is when
6035 you get the config right.
6040 It is essential to remember this, since it has some impact on the C
6041 code for the initialization procedures:
6043 * Initialized global data (data segment) is read-only. Do not attempt
6046 * Do not use any uninitialized global data (or implicitely initialized
6047 as zero data - BSS segment) at all - this is undefined, initiali-
6048 zation is performed later (when relocating to RAM).
6050 * Stack space is very limited. Avoid big data buffers or things like
6053 Having only the stack as writable memory limits means we cannot use
6054 normal global data to share information beween the code. But it
6055 turned out that the implementation of U-Boot can be greatly
6056 simplified by making a global data structure (gd_t) available to all
6057 functions. We could pass a pointer to this data as argument to _all_
6058 functions, but this would bloat the code. Instead we use a feature of
6059 the GCC compiler (Global Register Variables) to share the data: we
6060 place a pointer (gd) to the global data into a register which we
6061 reserve for this purpose.
6063 When choosing a register for such a purpose we are restricted by the
6064 relevant (E)ABI specifications for the current architecture, and by
6065 GCC's implementation.
6067 For PowerPC, the following registers have specific use:
6069 R2: reserved for system use
6070 R3-R4: parameter passing and return values
6071 R5-R10: parameter passing
6072 R13: small data area pointer
6076 (U-Boot also uses R12 as internal GOT pointer. r12
6077 is a volatile register so r12 needs to be reset when
6078 going back and forth between asm and C)
6080 ==> U-Boot will use R2 to hold a pointer to the global data
6082 Note: on PPC, we could use a static initializer (since the
6083 address of the global data structure is known at compile time),
6084 but it turned out that reserving a register results in somewhat
6085 smaller code - although the code savings are not that big (on
6086 average for all boards 752 bytes for the whole U-Boot image,
6087 624 text + 127 data).
6089 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
6090 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
6092 ==> U-Boot will use P3 to hold a pointer to the global data
6094 On ARM, the following registers are used:
6096 R0: function argument word/integer result
6097 R1-R3: function argument word
6098 R9: platform specific
6099 R10: stack limit (used only if stack checking is enabled)
6100 R11: argument (frame) pointer
6101 R12: temporary workspace
6104 R15: program counter
6106 ==> U-Boot will use R9 to hold a pointer to the global data
6108 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
6110 On Nios II, the ABI is documented here:
6111 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
6113 ==> U-Boot will use gp to hold a pointer to the global data
6115 Note: on Nios II, we give "-G0" option to gcc and don't use gp
6116 to access small data sections, so gp is free.
6118 On NDS32, the following registers are used:
6120 R0-R1: argument/return
6122 R15: temporary register for assembler
6123 R16: trampoline register
6124 R28: frame pointer (FP)
6125 R29: global pointer (GP)
6126 R30: link register (LP)
6127 R31: stack pointer (SP)
6128 PC: program counter (PC)
6130 ==> U-Boot will use R10 to hold a pointer to the global data
6132 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
6133 or current versions of GCC may "optimize" the code too much.
6138 U-Boot runs in system state and uses physical addresses, i.e. the
6139 MMU is not used either for address mapping nor for memory protection.
6141 The available memory is mapped to fixed addresses using the memory
6142 controller. In this process, a contiguous block is formed for each
6143 memory type (Flash, SDRAM, SRAM), even when it consists of several
6144 physical memory banks.
6146 U-Boot is installed in the first 128 kB of the first Flash bank (on
6147 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
6148 booting and sizing and initializing DRAM, the code relocates itself
6149 to the upper end of DRAM. Immediately below the U-Boot code some
6150 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
6151 configuration setting]. Below that, a structure with global Board
6152 Info data is placed, followed by the stack (growing downward).
6154 Additionally, some exception handler code is copied to the low 8 kB
6155 of DRAM (0x00000000 ... 0x00001FFF).
6157 So a typical memory configuration with 16 MB of DRAM could look like
6160 0x0000 0000 Exception Vector code
6163 0x0000 2000 Free for Application Use
6169 0x00FB FF20 Monitor Stack (Growing downward)
6170 0x00FB FFAC Board Info Data and permanent copy of global data
6171 0x00FC 0000 Malloc Arena
6174 0x00FE 0000 RAM Copy of Monitor Code
6175 ... eventually: LCD or video framebuffer
6176 ... eventually: pRAM (Protected RAM - unchanged by reset)
6177 0x00FF FFFF [End of RAM]
6180 System Initialization:
6181 ----------------------
6183 In the reset configuration, U-Boot starts at the reset entry point
6184 (on most PowerPC systems at address 0x00000100). Because of the reset
6185 configuration for CS0# this is a mirror of the onboard Flash memory.
6186 To be able to re-map memory U-Boot then jumps to its link address.
6187 To be able to implement the initialization code in C, a (small!)
6188 initial stack is set up in the internal Dual Ported RAM (in case CPUs
6189 which provide such a feature like MPC8xx or MPC8260), or in a locked
6190 part of the data cache. After that, U-Boot initializes the CPU core,
6191 the caches and the SIU.
6193 Next, all (potentially) available memory banks are mapped using a
6194 preliminary mapping. For example, we put them on 512 MB boundaries
6195 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
6196 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
6197 programmed for SDRAM access. Using the temporary configuration, a
6198 simple memory test is run that determines the size of the SDRAM
6201 When there is more than one SDRAM bank, and the banks are of
6202 different size, the largest is mapped first. For equal size, the first
6203 bank (CS2#) is mapped first. The first mapping is always for address
6204 0x00000000, with any additional banks following immediately to create
6205 contiguous memory starting from 0.
6207 Then, the monitor installs itself at the upper end of the SDRAM area
6208 and allocates memory for use by malloc() and for the global Board
6209 Info data; also, the exception vector code is copied to the low RAM
6210 pages, and the final stack is set up.
6212 Only after this relocation will you have a "normal" C environment;
6213 until that you are restricted in several ways, mostly because you are
6214 running from ROM, and because the code will have to be relocated to a
6218 U-Boot Porting Guide:
6219 ----------------------
6221 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
6225 int main(int argc, char *argv[])
6227 sighandler_t no_more_time;
6229 signal(SIGALRM, no_more_time);
6230 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
6232 if (available_money > available_manpower) {
6233 Pay consultant to port U-Boot;
6237 Download latest U-Boot source;
6239 Subscribe to u-boot mailing list;
6242 email("Hi, I am new to U-Boot, how do I get started?");
6245 Read the README file in the top level directory;
6246 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6247 Read applicable doc/*.README;
6248 Read the source, Luke;
6249 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6252 if (available_money > toLocalCurrency ($2500))
6255 Add a lot of aggravation and time;
6257 if (a similar board exists) { /* hopefully... */
6258 cp -a board/<similar> board/<myboard>
6259 cp include/configs/<similar>.h include/configs/<myboard>.h
6261 Create your own board support subdirectory;
6262 Create your own board include/configs/<myboard>.h file;
6264 Edit new board/<myboard> files
6265 Edit new include/configs/<myboard>.h
6270 Add / modify source code;
6274 email("Hi, I am having problems...");
6276 Send patch file to the U-Boot email list;
6277 if (reasonable critiques)
6278 Incorporate improvements from email list code review;
6280 Defend code as written;
6286 void no_more_time (int sig)
6295 All contributions to U-Boot should conform to the Linux kernel
6296 coding style; see the file "Documentation/CodingStyle" and the script
6297 "scripts/Lindent" in your Linux kernel source directory.
6299 Source files originating from a different project (for example the
6300 MTD subsystem) are generally exempt from these guidelines and are not
6301 reformated to ease subsequent migration to newer versions of those
6304 Please note that U-Boot is implemented in C (and to some small parts in
6305 Assembler); no C++ is used, so please do not use C++ style comments (//)
6308 Please also stick to the following formatting rules:
6309 - remove any trailing white space
6310 - use TAB characters for indentation and vertical alignment, not spaces
6311 - make sure NOT to use DOS '\r\n' line feeds
6312 - do not add more than 2 consecutive empty lines to source files
6313 - do not add trailing empty lines to source files
6315 Submissions which do not conform to the standards may be returned
6316 with a request to reformat the changes.
6322 Since the number of patches for U-Boot is growing, we need to
6323 establish some rules. Submissions which do not conform to these rules
6324 may be rejected, even when they contain important and valuable stuff.
6326 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6328 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6329 see http://lists.denx.de/mailman/listinfo/u-boot
6331 When you send a patch, please include the following information with
6334 * For bug fixes: a description of the bug and how your patch fixes
6335 this bug. Please try to include a way of demonstrating that the
6336 patch actually fixes something.
6338 * For new features: a description of the feature and your
6341 * A CHANGELOG entry as plaintext (separate from the patch)
6343 * For major contributions, your entry to the CREDITS file
6345 * When you add support for a new board, don't forget to add a
6346 maintainer e-mail address to the boards.cfg file, too.
6348 * If your patch adds new configuration options, don't forget to
6349 document these in the README file.
6351 * The patch itself. If you are using git (which is *strongly*
6352 recommended) you can easily generate the patch using the
6353 "git format-patch". If you then use "git send-email" to send it to
6354 the U-Boot mailing list, you will avoid most of the common problems
6355 with some other mail clients.
6357 If you cannot use git, use "diff -purN OLD NEW". If your version of
6358 diff does not support these options, then get the latest version of
6361 The current directory when running this command shall be the parent
6362 directory of the U-Boot source tree (i. e. please make sure that
6363 your patch includes sufficient directory information for the
6366 We prefer patches as plain text. MIME attachments are discouraged,
6367 and compressed attachments must not be used.
6369 * If one logical set of modifications affects or creates several
6370 files, all these changes shall be submitted in a SINGLE patch file.
6372 * Changesets that contain different, unrelated modifications shall be
6373 submitted as SEPARATE patches, one patch per changeset.
6378 * Before sending the patch, run the MAKEALL script on your patched
6379 source tree and make sure that no errors or warnings are reported
6380 for any of the boards.
6382 * Keep your modifications to the necessary minimum: A patch
6383 containing several unrelated changes or arbitrary reformats will be
6384 returned with a request to re-formatting / split it.
6386 * If you modify existing code, make sure that your new code does not
6387 add to the memory footprint of the code ;-) Small is beautiful!
6388 When adding new features, these should compile conditionally only
6389 (using #ifdef), and the resulting code with the new feature
6390 disabled must not need more memory than the old code without your
6393 * Remember that there is a size limit of 100 kB per message on the
6394 u-boot mailing list. Bigger patches will be moderated. If they are
6395 reasonable and not too big, they will be acknowledged. But patches
6396 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob