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 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /pxa Files specific to Intel XScale PXA CPUs
145 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 /lib Architecture specific library files
147 /avr32 Files generic to AVR32 architecture
148 /cpu CPU specific files
149 /lib Architecture specific library files
150 /blackfin Files generic to Analog Devices Blackfin architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /m68k Files generic to m68k architecture
154 /cpu CPU specific files
155 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
156 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
157 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
158 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
159 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
160 /lib Architecture specific library files
161 /microblaze Files generic to microblaze architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /mips Files generic to MIPS architecture
165 /cpu CPU specific files
166 /mips32 Files specific to MIPS32 CPUs
167 /xburst Files specific to Ingenic XBurst CPUs
168 /lib Architecture specific library files
169 /nds32 Files generic to NDS32 architecture
170 /cpu CPU specific files
171 /n1213 Files specific to Andes Technology N1213 CPUs
172 /lib Architecture specific library files
173 /nios2 Files generic to Altera NIOS2 architecture
174 /cpu CPU specific files
175 /lib Architecture specific library files
176 /openrisc Files generic to OpenRISC architecture
177 /cpu CPU specific files
178 /lib Architecture specific library files
179 /powerpc Files generic to PowerPC architecture
180 /cpu CPU specific files
181 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
182 /mpc5xx Files specific to Freescale MPC5xx CPUs
183 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
184 /mpc8xx Files specific to Freescale MPC8xx CPUs
185 /mpc824x Files specific to Freescale MPC824x CPUs
186 /mpc8260 Files specific to Freescale MPC8260 CPUs
187 /mpc85xx Files specific to Freescale MPC85xx CPUs
188 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
189 /lib Architecture specific library files
190 /sh Files generic to SH architecture
191 /cpu CPU specific files
192 /sh2 Files specific to sh2 CPUs
193 /sh3 Files specific to sh3 CPUs
194 /sh4 Files specific to sh4 CPUs
195 /lib Architecture specific library files
196 /sparc Files generic to SPARC architecture
197 /cpu CPU specific files
198 /leon2 Files specific to Gaisler LEON2 SPARC CPU
199 /leon3 Files specific to Gaisler LEON3 SPARC CPU
200 /lib Architecture specific library files
201 /x86 Files generic to x86 architecture
202 /cpu CPU specific files
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /dts Contains Makefile for building internal U-Boot fdt.
211 /examples Example code for standalone applications, etc.
212 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
213 /include Header Files
214 /lib Files generic to all architectures
215 /libfdt Library files to support flattened device trees
216 /lzma Library files to support LZMA decompression
217 /lzo Library files to support LZO decompression
219 /post Power On Self Test
220 /spl Secondary Program Loader framework
221 /tools Tools to build S-Record or U-Boot images, etc.
223 Software Configuration:
224 =======================
226 Configuration is usually done using C preprocessor defines; the
227 rationale behind that is to avoid dead code whenever possible.
229 There are two classes of configuration variables:
231 * Configuration _OPTIONS_:
232 These are selectable by the user and have names beginning with
235 * Configuration _SETTINGS_:
236 These depend on the hardware etc. and should not be meddled with if
237 you don't know what you're doing; they have names beginning with
240 Later we will add a configuration tool - probably similar to or even
241 identical to what's used for the Linux kernel. Right now, we have to
242 do the configuration by hand, which means creating some symbolic
243 links and editing some configuration files. We use the TQM8xxL boards
247 Selection of Processor Architecture and Board Type:
248 ---------------------------------------------------
250 For all supported boards there are ready-to-use default
251 configurations available; just type "make <board_name>_config".
253 Example: For a TQM823L module type:
258 For the Cogent platform, you need to specify the CPU type as well;
259 e.g. "make cogent_mpc8xx_config". And also configure the cogent
260 directory according to the instructions in cogent/README.
263 Configuration Options:
264 ----------------------
266 Configuration depends on the combination of board and CPU type; all
267 such information is kept in a configuration file
268 "include/configs/<board_name>.h".
270 Example: For a TQM823L module, all configuration settings are in
271 "include/configs/TQM823L.h".
274 Many of the options are named exactly as the corresponding Linux
275 kernel configuration options. The intention is to make it easier to
276 build a config tool - later.
279 The following options need to be configured:
281 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
283 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
285 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
286 Define exactly one, e.g. CONFIG_ATSTK1002
288 - CPU Module Type: (if CONFIG_COGENT is defined)
289 Define exactly one of
291 --- FIXME --- not tested yet:
292 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
293 CONFIG_CMA287_23, CONFIG_CMA287_50
295 - Motherboard Type: (if CONFIG_COGENT is defined)
296 Define exactly one of
297 CONFIG_CMA101, CONFIG_CMA102
299 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
300 Define one or more of
303 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
304 Define one or more of
305 CONFIG_LCD_HEARTBEAT - update a character position on
306 the LCD display every second with
309 - Board flavour: (if CONFIG_MPC8260ADS is defined)
312 CONFIG_SYS_8260ADS - original MPC8260ADS
313 CONFIG_SYS_8266ADS - MPC8266ADS
314 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
315 CONFIG_SYS_8272ADS - MPC8272ADS
317 - Marvell Family Member
318 CONFIG_SYS_MVFS - define it if you want to enable
319 multiple fs option at one time
320 for marvell soc family
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
357 Specifies that the core is a 64-bit PowerPC implementation (implements
358 the "64" category of the Power ISA). This is necessary for ePAPR
359 compliance, among other possible reasons.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 CONFIG_SYS_PPC_E500_DEBUG_TLB
374 Enables a temporary TLB entry to be used during boot to work
375 around limitations in e500v1 and e500v2 external debugger
376 support. This reduces the portions of the boot code where
377 breakpoints and single stepping do not work. The value of this
378 symbol should be set to the TLB1 entry to be used for this
381 CONFIG_SYS_FSL_ERRATUM_A004510
383 Enables a workaround for erratum A004510. If set,
384 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
390 Defines one or two SoC revisions (low 8 bits of SVR)
391 for which the A004510 workaround should be applied.
393 The rest of SVR is either not relevant to the decision
394 of whether the erratum is present (e.g. p2040 versus
395 p2041) or is implied by the build target, which controls
396 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
398 See Freescale App Note 4493 for more information about
401 CONFIG_A003399_NOR_WORKAROUND
402 Enables a workaround for IFC erratum A003399. It is only
403 requred during NOR boot.
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 CONFIG_SYS_CPC_REINIT_F
431 This CONFIG is defined when the CPC is configured as SRAM at the
432 time of U-boot entry and is required to be re-initialized.
435 Inidcates this SoC supports deep sleep feature. If deep sleep is
436 supported, core will start to execute uboot when wakes up.
438 - Generic CPU options:
439 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
441 Defines the endianess of the CPU. Implementation of those
442 values is arch specific.
445 Freescale DDR driver in use. This type of DDR controller is
446 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
449 CONFIG_SYS_FSL_DDR_ADDR
450 Freescale DDR memory-mapped register base.
452 CONFIG_SYS_FSL_DDR_EMU
453 Specify emulator support for DDR. Some DDR features such as
454 deskew training are not available.
456 CONFIG_SYS_FSL_DDRC_GEN1
457 Freescale DDR1 controller.
459 CONFIG_SYS_FSL_DDRC_GEN2
460 Freescale DDR2 controller.
462 CONFIG_SYS_FSL_DDRC_GEN3
463 Freescale DDR3 controller.
465 CONFIG_SYS_FSL_DDRC_GEN4
466 Freescale DDR4 controller.
468 CONFIG_SYS_FSL_DDRC_ARM_GEN3
469 Freescale DDR3 controller for ARM-based SoCs.
472 Board config to use DDR1. It can be enabled for SoCs with
473 Freescale DDR1 or DDR2 controllers, depending on the board
477 Board config to use DDR2. It can be eanbeld for SoCs with
478 Freescale DDR2 or DDR3 controllers, depending on the board
482 Board config to use DDR3. It can be enabled for SoCs with
483 Freescale DDR3 or DDR3L controllers.
486 Board config to use DDR3L. It can be enabled for SoCs with
490 Board config to use DDR4. It can be enabled for SoCs with
493 CONFIG_SYS_FSL_IFC_BE
494 Defines the IFC controller register space as Big Endian
496 CONFIG_SYS_FSL_IFC_LE
497 Defines the IFC controller register space as Little Endian
499 CONFIG_SYS_FSL_PBL_PBI
500 It enables addition of RCW (Power on reset configuration) in built image.
501 Please refer doc/README.pblimage for more details
503 CONFIG_SYS_FSL_PBL_RCW
504 It adds PBI(pre-boot instructions) commands in u-boot build image.
505 PBI commands can be used to configure SoC before it starts the execution.
506 Please refer doc/README.pblimage for more details
509 It adds a target to create boot binary having SPL binary in PBI format
510 concatenated with u-boot binary.
512 CONFIG_SYS_FSL_DDR_BE
513 Defines the DDR controller register space as Big Endian
515 CONFIG_SYS_FSL_DDR_LE
516 Defines the DDR controller register space as Little Endian
518 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
519 Physical address from the view of DDR controllers. It is the
520 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
521 it could be different for ARM SoCs.
523 CONFIG_SYS_FSL_DDR_INTLV_256B
524 DDR controller interleaving on 256-byte. This is a special
525 interleaving mode, handled by Dickens for Freescale layerscape
528 - Intel Monahans options:
529 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
531 Defines the Monahans run mode to oscillator
532 ratio. Valid values are 8, 16, 24, 31. The core
533 frequency is this value multiplied by 13 MHz.
535 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
537 Defines the Monahans turbo mode to oscillator
538 ratio. Valid values are 1 (default if undefined) and
539 2. The core frequency as calculated above is multiplied
543 CONFIG_SYS_INIT_SP_OFFSET
545 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
546 pointer. This is needed for the temporary stack before
549 CONFIG_SYS_MIPS_CACHE_MODE
551 Cache operation mode for the MIPS CPU.
552 See also arch/mips/include/asm/mipsregs.h.
554 CONF_CM_CACHABLE_NO_WA
557 CONF_CM_CACHABLE_NONCOHERENT
561 CONF_CM_CACHABLE_ACCELERATED
563 CONFIG_SYS_XWAY_EBU_BOOTCFG
565 Special option for Lantiq XWAY SoCs for booting from NOR flash.
566 See also arch/mips/cpu/mips32/start.S.
568 CONFIG_XWAY_SWAP_BYTES
570 Enable compilation of tools/xway-swap-bytes needed for Lantiq
571 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
572 be swapped if a flash programmer is used.
575 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
577 Select high exception vectors of the ARM core, e.g., do not
578 clear the V bit of the c1 register of CP15.
580 CONFIG_SYS_THUMB_BUILD
582 Use this flag to build U-Boot using the Thumb instruction
583 set for ARM architectures. Thumb instruction set provides
584 better code density. For ARM architectures that support
585 Thumb2 this flag will result in Thumb2 code generated by
588 CONFIG_ARM_ERRATA_716044
589 CONFIG_ARM_ERRATA_742230
590 CONFIG_ARM_ERRATA_743622
591 CONFIG_ARM_ERRATA_751472
592 CONFIG_ARM_ERRATA_794072
593 CONFIG_ARM_ERRATA_761320
595 If set, the workarounds for these ARM errata are applied early
596 during U-Boot startup. Note that these options force the
597 workarounds to be applied; no CPU-type/version detection
598 exists, unlike the similar options in the Linux kernel. Do not
599 set these options unless they apply!
604 The frequency of the timer returned by get_timer().
605 get_timer() must operate in milliseconds and this CONFIG
606 option must be set to 1000.
608 - Linux Kernel Interface:
611 U-Boot stores all clock information in Hz
612 internally. For binary compatibility with older Linux
613 kernels (which expect the clocks passed in the
614 bd_info data to be in MHz) the environment variable
615 "clocks_in_mhz" can be defined so that U-Boot
616 converts clock data to MHZ before passing it to the
618 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
619 "clocks_in_mhz=1" is automatically included in the
622 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
624 When transferring memsize parameter to linux, some versions
625 expect it to be in bytes, others in MB.
626 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
630 New kernel versions are expecting firmware settings to be
631 passed using flattened device trees (based on open firmware
635 * New libfdt-based support
636 * Adds the "fdt" command
637 * The bootm command automatically updates the fdt
639 OF_CPU - The proper name of the cpus node (only required for
640 MPC512X and MPC5xxx based boards).
641 OF_SOC - The proper name of the soc node (only required for
642 MPC512X and MPC5xxx based boards).
643 OF_TBCLK - The timebase frequency.
644 OF_STDOUT_PATH - The path to the console device
646 boards with QUICC Engines require OF_QE to set UCC MAC
649 CONFIG_OF_BOARD_SETUP
651 Board code has addition modification that it wants to make
652 to the flat device tree before handing it off to the kernel
656 This define fills in the correct boot CPU in the boot
657 param header, the default value is zero if undefined.
661 U-Boot can detect if an IDE device is present or not.
662 If not, and this new config option is activated, U-Boot
663 removes the ATA node from the DTS before booting Linux,
664 so the Linux IDE driver does not probe the device and
665 crash. This is needed for buggy hardware (uc101) where
666 no pull down resistor is connected to the signal IDE5V_DD7.
668 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
670 This setting is mandatory for all boards that have only one
671 machine type and must be used to specify the machine type
672 number as it appears in the ARM machine registry
673 (see http://www.arm.linux.org.uk/developer/machines/).
674 Only boards that have multiple machine types supported
675 in a single configuration file and the machine type is
676 runtime discoverable, do not have to use this setting.
678 - vxWorks boot parameters:
680 bootvx constructs a valid bootline using the following
681 environments variables: bootfile, ipaddr, serverip, hostname.
682 It loads the vxWorks image pointed bootfile.
684 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
685 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
686 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
687 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
689 CONFIG_SYS_VXWORKS_ADD_PARAMS
691 Add it at the end of the bootline. E.g "u=username pw=secret"
693 Note: If a "bootargs" environment is defined, it will overwride
694 the defaults discussed just above.
696 - Cache Configuration:
697 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
698 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
699 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
701 - Cache Configuration for ARM:
702 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
704 CONFIG_SYS_PL310_BASE - Physical base address of PL310
705 controller register space
710 Define this if you want support for Amba PrimeCell PL010 UARTs.
714 Define this if you want support for Amba PrimeCell PL011 UARTs.
718 If you have Amba PrimeCell PL011 UARTs, set this variable to
719 the clock speed of the UARTs.
723 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
724 define this to a list of base addresses for each (supported)
725 port. See e.g. include/configs/versatile.h
727 CONFIG_PL011_SERIAL_RLCR
729 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
730 have separate receive and transmit line control registers. Set
731 this variable to initialize the extra register.
733 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
735 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
736 boot loader that has already initialized the UART. Define this
737 variable to flush the UART at init time.
741 Depending on board, define exactly one serial port
742 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
743 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
744 console by defining CONFIG_8xx_CONS_NONE
746 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
747 port routines must be defined elsewhere
748 (i.e. serial_init(), serial_getc(), ...)
751 Enables console device for a color framebuffer. Needs following
752 defines (cf. smiLynxEM, i8042)
753 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
755 VIDEO_HW_RECTFILL graphic chip supports
758 VIDEO_HW_BITBLT graphic chip supports
759 bit-blit (cf. smiLynxEM)
760 VIDEO_VISIBLE_COLS visible pixel columns
762 VIDEO_VISIBLE_ROWS visible pixel rows
763 VIDEO_PIXEL_SIZE bytes per pixel
764 VIDEO_DATA_FORMAT graphic data format
765 (0-5, cf. cfb_console.c)
766 VIDEO_FB_ADRS framebuffer address
767 VIDEO_KBD_INIT_FCT keyboard int fct
768 (i.e. i8042_kbd_init())
769 VIDEO_TSTC_FCT test char fct
771 VIDEO_GETC_FCT get char fct
773 CONFIG_CONSOLE_CURSOR cursor drawing on/off
774 (requires blink timer
776 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
777 CONFIG_CONSOLE_TIME display time/date info in
779 (requires CONFIG_CMD_DATE)
780 CONFIG_VIDEO_LOGO display Linux logo in
782 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
783 linux_logo.h for logo.
784 Requires CONFIG_VIDEO_LOGO
785 CONFIG_CONSOLE_EXTRA_INFO
786 additional board info beside
789 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
790 a limited number of ANSI escape sequences (cursor control,
791 erase functions and limited graphics rendition control).
793 When CONFIG_CFB_CONSOLE is defined, video console is
794 default i/o. Serial console can be forced with
795 environment 'console=serial'.
797 When CONFIG_SILENT_CONSOLE is defined, all console
798 messages (by U-Boot and Linux!) can be silenced with
799 the "silent" environment variable. See
800 doc/README.silent for more information.
802 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
804 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
808 CONFIG_BAUDRATE - in bps
809 Select one of the baudrates listed in
810 CONFIG_SYS_BAUDRATE_TABLE, see below.
811 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
813 - Console Rx buffer length
814 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
815 the maximum receive buffer length for the SMC.
816 This option is actual only for 82xx and 8xx possible.
817 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
818 must be defined, to setup the maximum idle timeout for
821 - Pre-Console Buffer:
822 Prior to the console being initialised (i.e. serial UART
823 initialised etc) all console output is silently discarded.
824 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
825 buffer any console messages prior to the console being
826 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
827 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
828 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
829 bytes are output before the console is initialised, the
830 earlier bytes are discarded.
832 'Sane' compilers will generate smaller code if
833 CONFIG_PRE_CON_BUF_SZ is a power of 2
835 - Safe printf() functions
836 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
837 the printf() functions. These are defined in
838 include/vsprintf.h and include snprintf(), vsnprintf() and
839 so on. Code size increase is approximately 300-500 bytes.
840 If this option is not given then these functions will
841 silently discard their buffer size argument - this means
842 you are not getting any overflow checking in this case.
844 - Boot Delay: CONFIG_BOOTDELAY - in seconds
845 Delay before automatically booting the default image;
846 set to -1 to disable autoboot.
847 set to -2 to autoboot with no delay and not check for abort
848 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
850 See doc/README.autoboot for these options that
851 work with CONFIG_BOOTDELAY. None are required.
852 CONFIG_BOOT_RETRY_TIME
853 CONFIG_BOOT_RETRY_MIN
854 CONFIG_AUTOBOOT_KEYED
855 CONFIG_AUTOBOOT_PROMPT
856 CONFIG_AUTOBOOT_DELAY_STR
857 CONFIG_AUTOBOOT_STOP_STR
858 CONFIG_AUTOBOOT_DELAY_STR2
859 CONFIG_AUTOBOOT_STOP_STR2
860 CONFIG_ZERO_BOOTDELAY_CHECK
861 CONFIG_RESET_TO_RETRY
865 Only needed when CONFIG_BOOTDELAY is enabled;
866 define a command string that is automatically executed
867 when no character is read on the console interface
868 within "Boot Delay" after reset.
871 This can be used to pass arguments to the bootm
872 command. The value of CONFIG_BOOTARGS goes into the
873 environment value "bootargs".
875 CONFIG_RAMBOOT and CONFIG_NFSBOOT
876 The value of these goes into the environment as
877 "ramboot" and "nfsboot" respectively, and can be used
878 as a convenience, when switching between booting from
882 CONFIG_BOOTCOUNT_LIMIT
883 Implements a mechanism for detecting a repeating reboot
885 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
888 If no softreset save registers are found on the hardware
889 "bootcount" is stored in the environment. To prevent a
890 saveenv on all reboots, the environment variable
891 "upgrade_available" is used. If "upgrade_available" is
892 0, "bootcount" is always 0, if "upgrade_available" is
893 1 "bootcount" is incremented in the environment.
894 So the Userspace Applikation must set the "upgrade_available"
895 and "bootcount" variable to 0, if a boot was successfully.
900 When this option is #defined, the existence of the
901 environment variable "preboot" will be checked
902 immediately before starting the CONFIG_BOOTDELAY
903 countdown and/or running the auto-boot command resp.
904 entering interactive mode.
906 This feature is especially useful when "preboot" is
907 automatically generated or modified. For an example
908 see the LWMON board specific code: here "preboot" is
909 modified when the user holds down a certain
910 combination of keys on the (special) keyboard when
913 - Serial Download Echo Mode:
915 If defined to 1, all characters received during a
916 serial download (using the "loads" command) are
917 echoed back. This might be needed by some terminal
918 emulations (like "cu"), but may as well just take
919 time on others. This setting #define's the initial
920 value of the "loads_echo" environment variable.
922 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
924 Select one of the baudrates listed in
925 CONFIG_SYS_BAUDRATE_TABLE, see below.
928 Monitor commands can be included or excluded
929 from the build by using the #include files
930 <config_cmd_all.h> and #undef'ing unwanted
931 commands, or using <config_cmd_default.h>
932 and augmenting with additional #define's
935 The default command configuration includes all commands
936 except those marked below with a "*".
938 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
939 CONFIG_CMD_ASKENV * ask for env variable
940 CONFIG_CMD_BDI bdinfo
941 CONFIG_CMD_BEDBUG * Include BedBug Debugger
942 CONFIG_CMD_BMP * BMP support
943 CONFIG_CMD_BSP * Board specific commands
944 CONFIG_CMD_BOOTD bootd
945 CONFIG_CMD_CACHE * icache, dcache
946 CONFIG_CMD_CLK * clock command support
947 CONFIG_CMD_CONSOLE coninfo
948 CONFIG_CMD_CRC32 * crc32
949 CONFIG_CMD_DATE * support for RTC, date/time...
950 CONFIG_CMD_DHCP * DHCP support
951 CONFIG_CMD_DIAG * Diagnostics
952 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
953 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
954 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
955 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
956 CONFIG_CMD_DTT * Digital Therm and Thermostat
957 CONFIG_CMD_ECHO echo arguments
958 CONFIG_CMD_EDITENV edit env variable
959 CONFIG_CMD_EEPROM * EEPROM read/write support
960 CONFIG_CMD_ELF * bootelf, bootvx
961 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
962 CONFIG_CMD_ENV_FLAGS * display details about env flags
963 CONFIG_CMD_ENV_EXISTS * check existence of env variable
964 CONFIG_CMD_EXPORTENV * export the environment
965 CONFIG_CMD_EXT2 * ext2 command support
966 CONFIG_CMD_EXT4 * ext4 command support
967 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
968 that work for multiple fs types
969 CONFIG_CMD_SAVEENV saveenv
970 CONFIG_CMD_FDC * Floppy Disk Support
971 CONFIG_CMD_FAT * FAT command support
972 CONFIG_CMD_FLASH flinfo, erase, protect
973 CONFIG_CMD_FPGA FPGA device initialization support
974 CONFIG_CMD_FUSE * Device fuse support
975 CONFIG_CMD_GETTIME * Get time since boot
976 CONFIG_CMD_GO * the 'go' command (exec code)
977 CONFIG_CMD_GREPENV * search environment
978 CONFIG_CMD_HASH * calculate hash / digest
979 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
980 CONFIG_CMD_I2C * I2C serial bus support
981 CONFIG_CMD_IDE * IDE harddisk support
982 CONFIG_CMD_IMI iminfo
983 CONFIG_CMD_IMLS List all images found in NOR flash
984 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
985 CONFIG_CMD_IMMAP * IMMR dump support
986 CONFIG_CMD_IMPORTENV * import an environment
987 CONFIG_CMD_INI * import data from an ini file into the env
988 CONFIG_CMD_IRQ * irqinfo
989 CONFIG_CMD_ITEST Integer/string test of 2 values
990 CONFIG_CMD_JFFS2 * JFFS2 Support
991 CONFIG_CMD_KGDB * kgdb
992 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
993 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
995 CONFIG_CMD_LOADB loadb
996 CONFIG_CMD_LOADS loads
997 CONFIG_CMD_MD5SUM * print md5 message digest
998 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
999 CONFIG_CMD_MEMINFO * Display detailed memory information
1000 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
1002 CONFIG_CMD_MEMTEST * mtest
1003 CONFIG_CMD_MISC Misc functions like sleep etc
1004 CONFIG_CMD_MMC * MMC memory mapped support
1005 CONFIG_CMD_MII * MII utility commands
1006 CONFIG_CMD_MTDPARTS * MTD partition support
1007 CONFIG_CMD_NAND * NAND support
1008 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1009 CONFIG_CMD_NFS NFS support
1010 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1011 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1012 CONFIG_CMD_PCI * pciinfo
1013 CONFIG_CMD_PCMCIA * PCMCIA support
1014 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1016 CONFIG_CMD_PORTIO * Port I/O
1017 CONFIG_CMD_READ * Read raw data from partition
1018 CONFIG_CMD_REGINFO * Register dump
1019 CONFIG_CMD_RUN run command in env variable
1020 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1021 CONFIG_CMD_SAVES * save S record dump
1022 CONFIG_CMD_SCSI * SCSI Support
1023 CONFIG_CMD_SDRAM * print SDRAM configuration information
1024 (requires CONFIG_CMD_I2C)
1025 CONFIG_CMD_SETGETDCR Support for DCR Register access
1027 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1028 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1029 (requires CONFIG_CMD_MEMORY)
1030 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1031 CONFIG_CMD_SOURCE "source" command Support
1032 CONFIG_CMD_SPI * SPI serial bus support
1033 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1034 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1035 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1036 CONFIG_CMD_TIMER * access to the system tick timer
1037 CONFIG_CMD_USB * USB support
1038 CONFIG_CMD_CDP * Cisco Discover Protocol support
1039 CONFIG_CMD_MFSL * Microblaze FSL support
1040 CONFIG_CMD_XIMG Load part of Multi Image
1041 CONFIG_CMD_UUID * Generate random UUID or GUID string
1043 EXAMPLE: If you want all functions except of network
1044 support you can write:
1046 #include "config_cmd_all.h"
1047 #undef CONFIG_CMD_NET
1050 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1052 Note: Don't enable the "icache" and "dcache" commands
1053 (configuration option CONFIG_CMD_CACHE) unless you know
1054 what you (and your U-Boot users) are doing. Data
1055 cache cannot be enabled on systems like the 8xx or
1056 8260 (where accesses to the IMMR region must be
1057 uncached), and it cannot be disabled on all other
1058 systems where we (mis-) use the data cache to hold an
1059 initial stack and some data.
1062 XXX - this list needs to get updated!
1064 - Regular expression support:
1066 If this variable is defined, U-Boot is linked against
1067 the SLRE (Super Light Regular Expression) library,
1068 which adds regex support to some commands, as for
1069 example "env grep" and "setexpr".
1073 If this variable is defined, U-Boot will use a device tree
1074 to configure its devices, instead of relying on statically
1075 compiled #defines in the board file. This option is
1076 experimental and only available on a few boards. The device
1077 tree is available in the global data as gd->fdt_blob.
1079 U-Boot needs to get its device tree from somewhere. This can
1080 be done using one of the two options below:
1083 If this variable is defined, U-Boot will embed a device tree
1084 binary in its image. This device tree file should be in the
1085 board directory and called <soc>-<board>.dts. The binary file
1086 is then picked up in board_init_f() and made available through
1087 the global data structure as gd->blob.
1090 If this variable is defined, U-Boot will build a device tree
1091 binary. It will be called u-boot.dtb. Architecture-specific
1092 code will locate it at run-time. Generally this works by:
1094 cat u-boot.bin u-boot.dtb >image.bin
1096 and in fact, U-Boot does this for you, creating a file called
1097 u-boot-dtb.bin which is useful in the common case. You can
1098 still use the individual files if you need something more
1103 If this variable is defined, it enables watchdog
1104 support for the SoC. There must be support in the SoC
1105 specific code for a watchdog. For the 8xx and 8260
1106 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1107 register. When supported for a specific SoC is
1108 available, then no further board specific code should
1109 be needed to use it.
1112 When using a watchdog circuitry external to the used
1113 SoC, then define this variable and provide board
1114 specific code for the "hw_watchdog_reset" function.
1117 CONFIG_VERSION_VARIABLE
1118 If this variable is defined, an environment variable
1119 named "ver" is created by U-Boot showing the U-Boot
1120 version as printed by the "version" command.
1121 Any change to this variable will be reverted at the
1126 When CONFIG_CMD_DATE is selected, the type of the RTC
1127 has to be selected, too. Define exactly one of the
1130 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1131 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1132 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1133 CONFIG_RTC_MC146818 - use MC146818 RTC
1134 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1135 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1136 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1137 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1138 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1139 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1140 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1141 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1144 Note that if the RTC uses I2C, then the I2C interface
1145 must also be configured. See I2C Support, below.
1148 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1150 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1151 chip-ngpio pairs that tell the PCA953X driver the number of
1152 pins supported by a particular chip.
1154 Note that if the GPIO device uses I2C, then the I2C interface
1155 must also be configured. See I2C Support, below.
1157 - Timestamp Support:
1159 When CONFIG_TIMESTAMP is selected, the timestamp
1160 (date and time) of an image is printed by image
1161 commands like bootm or iminfo. This option is
1162 automatically enabled when you select CONFIG_CMD_DATE .
1164 - Partition Labels (disklabels) Supported:
1165 Zero or more of the following:
1166 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1167 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1168 Intel architecture, USB sticks, etc.
1169 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1170 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1171 bootloader. Note 2TB partition limit; see
1173 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1175 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1176 CONFIG_CMD_SCSI) you must configure support for at
1177 least one non-MTD partition type as well.
1180 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1181 board configurations files but used nowhere!
1183 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1184 be performed by calling the function
1185 ide_set_reset(int reset)
1186 which has to be defined in a board specific file
1191 Set this to enable ATAPI support.
1196 Set this to enable support for disks larger than 137GB
1197 Also look at CONFIG_SYS_64BIT_LBA.
1198 Whithout these , LBA48 support uses 32bit variables and will 'only'
1199 support disks up to 2.1TB.
1201 CONFIG_SYS_64BIT_LBA:
1202 When enabled, makes the IDE subsystem use 64bit sector addresses.
1206 At the moment only there is only support for the
1207 SYM53C8XX SCSI controller; define
1208 CONFIG_SCSI_SYM53C8XX to enable it.
1210 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1211 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1212 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1213 maximum numbers of LUNs, SCSI ID's and target
1215 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1217 The environment variable 'scsidevs' is set to the number of
1218 SCSI devices found during the last scan.
1220 - NETWORK Support (PCI):
1222 Support for Intel 8254x/8257x gigabit chips.
1225 Utility code for direct access to the SPI bus on Intel 8257x.
1226 This does not do anything useful unless you set at least one
1227 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1229 CONFIG_E1000_SPI_GENERIC
1230 Allow generic access to the SPI bus on the Intel 8257x, for
1231 example with the "sspi" command.
1234 Management command for E1000 devices. When used on devices
1235 with SPI support you can reprogram the EEPROM from U-Boot.
1237 CONFIG_E1000_FALLBACK_MAC
1238 default MAC for empty EEPROM after production.
1241 Support for Intel 82557/82559/82559ER chips.
1242 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1243 write routine for first time initialisation.
1246 Support for Digital 2114x chips.
1247 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1248 modem chip initialisation (KS8761/QS6611).
1251 Support for National dp83815 chips.
1254 Support for National dp8382[01] gigabit chips.
1256 - NETWORK Support (other):
1258 CONFIG_DRIVER_AT91EMAC
1259 Support for AT91RM9200 EMAC.
1262 Define this to use reduced MII inteface
1264 CONFIG_DRIVER_AT91EMAC_QUIET
1265 If this defined, the driver is quiet.
1266 The driver doen't show link status messages.
1268 CONFIG_CALXEDA_XGMAC
1269 Support for the Calxeda XGMAC device
1272 Support for SMSC's LAN91C96 chips.
1274 CONFIG_LAN91C96_BASE
1275 Define this to hold the physical address
1276 of the LAN91C96's I/O space
1278 CONFIG_LAN91C96_USE_32_BIT
1279 Define this to enable 32 bit addressing
1282 Support for SMSC's LAN91C111 chip
1284 CONFIG_SMC91111_BASE
1285 Define this to hold the physical address
1286 of the device (I/O space)
1288 CONFIG_SMC_USE_32_BIT
1289 Define this if data bus is 32 bits
1291 CONFIG_SMC_USE_IOFUNCS
1292 Define this to use i/o functions instead of macros
1293 (some hardware wont work with macros)
1295 CONFIG_DRIVER_TI_EMAC
1296 Support for davinci emac
1298 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1299 Define this if you have more then 3 PHYs.
1302 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1304 CONFIG_FTGMAC100_EGIGA
1305 Define this to use GE link update with gigabit PHY.
1306 Define this if FTGMAC100 is connected to gigabit PHY.
1307 If your system has 10/100 PHY only, it might not occur
1308 wrong behavior. Because PHY usually return timeout or
1309 useless data when polling gigabit status and gigabit
1310 control registers. This behavior won't affect the
1311 correctnessof 10/100 link speed update.
1314 Support for SMSC's LAN911x and LAN921x chips
1317 Define this to hold the physical address
1318 of the device (I/O space)
1320 CONFIG_SMC911X_32_BIT
1321 Define this if data bus is 32 bits
1323 CONFIG_SMC911X_16_BIT
1324 Define this if data bus is 16 bits. If your processor
1325 automatically converts one 32 bit word to two 16 bit
1326 words you may also try CONFIG_SMC911X_32_BIT.
1329 Support for Renesas on-chip Ethernet controller
1331 CONFIG_SH_ETHER_USE_PORT
1332 Define the number of ports to be used
1334 CONFIG_SH_ETHER_PHY_ADDR
1335 Define the ETH PHY's address
1337 CONFIG_SH_ETHER_CACHE_WRITEBACK
1338 If this option is set, the driver enables cache flush.
1342 Support TPM devices.
1345 Support for i2c bus TPM devices. Only one device
1346 per system is supported at this time.
1348 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1349 Define the the i2c bus number for the TPM device
1351 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1352 Define the TPM's address on the i2c bus
1354 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1355 Define the burst count bytes upper limit
1357 CONFIG_TPM_ATMEL_TWI
1358 Support for Atmel TWI TPM device. Requires I2C support.
1361 Support for generic parallel port TPM devices. Only one device
1362 per system is supported at this time.
1364 CONFIG_TPM_TIS_BASE_ADDRESS
1365 Base address where the generic TPM device is mapped
1366 to. Contemporary x86 systems usually map it at
1370 Add tpm monitor functions.
1371 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1372 provides monitor access to authorized functions.
1375 Define this to enable the TPM support library which provides
1376 functional interfaces to some TPM commands.
1377 Requires support for a TPM device.
1379 CONFIG_TPM_AUTH_SESSIONS
1380 Define this to enable authorized functions in the TPM library.
1381 Requires CONFIG_TPM and CONFIG_SHA1.
1384 At the moment only the UHCI host controller is
1385 supported (PIP405, MIP405, MPC5200); define
1386 CONFIG_USB_UHCI to enable it.
1387 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1388 and define CONFIG_USB_STORAGE to enable the USB
1391 Supported are USB Keyboards and USB Floppy drives
1393 MPC5200 USB requires additional defines:
1395 for 528 MHz Clock: 0x0001bbbb
1399 for differential drivers: 0x00001000
1400 for single ended drivers: 0x00005000
1401 for differential drivers on PSC3: 0x00000100
1402 for single ended drivers on PSC3: 0x00004100
1403 CONFIG_SYS_USB_EVENT_POLL
1404 May be defined to allow interrupt polling
1405 instead of using asynchronous interrupts
1407 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1408 txfilltuning field in the EHCI controller on reset.
1410 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1411 interval for usb hub power-on delay.(minimum 100msec)
1414 Define the below if you wish to use the USB console.
1415 Once firmware is rebuilt from a serial console issue the
1416 command "setenv stdin usbtty; setenv stdout usbtty" and
1417 attach your USB cable. The Unix command "dmesg" should print
1418 it has found a new device. The environment variable usbtty
1419 can be set to gserial or cdc_acm to enable your device to
1420 appear to a USB host as a Linux gserial device or a
1421 Common Device Class Abstract Control Model serial device.
1422 If you select usbtty = gserial you should be able to enumerate
1424 # modprobe usbserial vendor=0xVendorID product=0xProductID
1425 else if using cdc_acm, simply setting the environment
1426 variable usbtty to be cdc_acm should suffice. The following
1427 might be defined in YourBoardName.h
1430 Define this to build a UDC device
1433 Define this to have a tty type of device available to
1434 talk to the UDC device
1437 Define this to enable the high speed support for usb
1438 device and usbtty. If this feature is enabled, a routine
1439 int is_usbd_high_speed(void)
1440 also needs to be defined by the driver to dynamically poll
1441 whether the enumeration has succeded at high speed or full
1444 CONFIG_SYS_CONSOLE_IS_IN_ENV
1445 Define this if you want stdin, stdout &/or stderr to
1449 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1450 Derive USB clock from external clock "blah"
1451 - CONFIG_SYS_USB_EXTC_CLK 0x02
1453 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1454 Derive USB clock from brgclk
1455 - CONFIG_SYS_USB_BRG_CLK 0x04
1457 If you have a USB-IF assigned VendorID then you may wish to
1458 define your own vendor specific values either in BoardName.h
1459 or directly in usbd_vendor_info.h. If you don't define
1460 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1461 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1462 should pretend to be a Linux device to it's target host.
1464 CONFIG_USBD_MANUFACTURER
1465 Define this string as the name of your company for
1466 - CONFIG_USBD_MANUFACTURER "my company"
1468 CONFIG_USBD_PRODUCT_NAME
1469 Define this string as the name of your product
1470 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1472 CONFIG_USBD_VENDORID
1473 Define this as your assigned Vendor ID from the USB
1474 Implementors Forum. This *must* be a genuine Vendor ID
1475 to avoid polluting the USB namespace.
1476 - CONFIG_USBD_VENDORID 0xFFFF
1478 CONFIG_USBD_PRODUCTID
1479 Define this as the unique Product ID
1481 - CONFIG_USBD_PRODUCTID 0xFFFF
1483 Some USB device drivers may need to check USB cable attachment.
1484 In this case you can enable following config in BoardName.h:
1485 CONFIG_USB_CABLE_CHECK
1486 This enables function definition:
1487 - usb_cable_connected() in include/usb.h
1488 Implementation of this function is board-specific.
1490 - ULPI Layer Support:
1491 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1492 the generic ULPI layer. The generic layer accesses the ULPI PHY
1493 via the platform viewport, so you need both the genric layer and
1494 the viewport enabled. Currently only Chipidea/ARC based
1495 viewport is supported.
1496 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1497 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1498 If your ULPI phy needs a different reference clock than the
1499 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1500 the appropriate value in Hz.
1503 The MMC controller on the Intel PXA is supported. To
1504 enable this define CONFIG_MMC. The MMC can be
1505 accessed from the boot prompt by mapping the device
1506 to physical memory similar to flash. Command line is
1507 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1508 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1511 Support for Renesas on-chip MMCIF controller
1513 CONFIG_SH_MMCIF_ADDR
1514 Define the base address of MMCIF registers
1517 Define the clock frequency for MMCIF
1519 - USB Device Firmware Update (DFU) class support:
1521 This enables the USB portion of the DFU USB class
1524 This enables the command "dfu" which is used to have
1525 U-Boot create a DFU class device via USB. This command
1526 requires that the "dfu_alt_info" environment variable be
1527 set and define the alt settings to expose to the host.
1530 This enables support for exposing (e)MMC devices via DFU.
1533 This enables support for exposing NAND devices via DFU.
1536 This enables support for exposing RAM via DFU.
1537 Note: DFU spec refer to non-volatile memory usage, but
1538 allow usages beyond the scope of spec - here RAM usage,
1539 one that would help mostly the developer.
1541 CONFIG_SYS_DFU_DATA_BUF_SIZE
1542 Dfu transfer uses a buffer before writing data to the
1543 raw storage device. Make the size (in bytes) of this buffer
1544 configurable. The size of this buffer is also configurable
1545 through the "dfu_bufsiz" environment variable.
1547 CONFIG_SYS_DFU_MAX_FILE_SIZE
1548 When updating files rather than the raw storage device,
1549 we use a static buffer to copy the file into and then write
1550 the buffer once we've been given the whole file. Define
1551 this to the maximum filesize (in bytes) for the buffer.
1552 Default is 4 MiB if undefined.
1554 DFU_DEFAULT_POLL_TIMEOUT
1555 Poll timeout [ms], is the timeout a device can send to the
1556 host. The host must wait for this timeout before sending
1557 a subsequent DFU_GET_STATUS request to the device.
1559 DFU_MANIFEST_POLL_TIMEOUT
1560 Poll timeout [ms], which the device sends to the host when
1561 entering dfuMANIFEST state. Host waits this timeout, before
1562 sending again an USB request to the device.
1564 - Journaling Flash filesystem support:
1565 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1566 CONFIG_JFFS2_NAND_DEV
1567 Define these for a default partition on a NAND device
1569 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1570 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1571 Define these for a default partition on a NOR device
1573 CONFIG_SYS_JFFS_CUSTOM_PART
1574 Define this to create an own partition. You have to provide a
1575 function struct part_info* jffs2_part_info(int part_num)
1577 If you define only one JFFS2 partition you may also want to
1578 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1579 to disable the command chpart. This is the default when you
1580 have not defined a custom partition
1582 - FAT(File Allocation Table) filesystem write function support:
1585 Define this to enable support for saving memory data as a
1586 file in FAT formatted partition.
1588 This will also enable the command "fatwrite" enabling the
1589 user to write files to FAT.
1591 CBFS (Coreboot Filesystem) support
1594 Define this to enable support for reading from a Coreboot
1595 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1601 Define this to enable standard (PC-Style) keyboard
1605 Standard PC keyboard driver with US (is default) and
1606 GERMAN key layout (switch via environment 'keymap=de') support.
1607 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1608 for cfb_console. Supports cursor blinking.
1611 Enables a Chrome OS keyboard using the CROS_EC interface.
1612 This uses CROS_EC to communicate with a second microcontroller
1613 which provides key scans on request.
1618 Define this to enable video support (for output to
1621 CONFIG_VIDEO_CT69000
1623 Enable Chips & Technologies 69000 Video chip
1625 CONFIG_VIDEO_SMI_LYNXEM
1626 Enable Silicon Motion SMI 712/710/810 Video chip. The
1627 video output is selected via environment 'videoout'
1628 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1631 For the CT69000 and SMI_LYNXEM drivers, videomode is
1632 selected via environment 'videomode'. Two different ways
1634 - "videomode=num" 'num' is a standard LiLo mode numbers.
1635 Following standard modes are supported (* is default):
1637 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1638 -------------+---------------------------------------------
1639 8 bits | 0x301* 0x303 0x305 0x161 0x307
1640 15 bits | 0x310 0x313 0x316 0x162 0x319
1641 16 bits | 0x311 0x314 0x317 0x163 0x31A
1642 24 bits | 0x312 0x315 0x318 ? 0x31B
1643 -------------+---------------------------------------------
1644 (i.e. setenv videomode 317; saveenv; reset;)
1646 - "videomode=bootargs" all the video parameters are parsed
1647 from the bootargs. (See drivers/video/videomodes.c)
1650 CONFIG_VIDEO_SED13806
1651 Enable Epson SED13806 driver. This driver supports 8bpp
1652 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1653 or CONFIG_VIDEO_SED13806_16BPP
1656 Enable the Freescale DIU video driver. Reference boards for
1657 SOCs that have a DIU should define this macro to enable DIU
1658 support, and should also define these other macros:
1664 CONFIG_VIDEO_SW_CURSOR
1665 CONFIG_VGA_AS_SINGLE_DEVICE
1667 CONFIG_VIDEO_BMP_LOGO
1669 The DIU driver will look for the 'video-mode' environment
1670 variable, and if defined, enable the DIU as a console during
1671 boot. See the documentation file README.video for a
1672 description of this variable.
1676 Enable the VGA video / BIOS for x86. The alternative if you
1677 are using coreboot is to use the coreboot frame buffer
1684 Define this to enable a custom keyboard support.
1685 This simply calls drv_keyboard_init() which must be
1686 defined in your board-specific files.
1687 The only board using this so far is RBC823.
1689 - LCD Support: CONFIG_LCD
1691 Define this to enable LCD support (for output to LCD
1692 display); also select one of the supported displays
1693 by defining one of these:
1697 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1699 CONFIG_NEC_NL6448AC33:
1701 NEC NL6448AC33-18. Active, color, single scan.
1703 CONFIG_NEC_NL6448BC20
1705 NEC NL6448BC20-08. 6.5", 640x480.
1706 Active, color, single scan.
1708 CONFIG_NEC_NL6448BC33_54
1710 NEC NL6448BC33-54. 10.4", 640x480.
1711 Active, color, single scan.
1715 Sharp 320x240. Active, color, single scan.
1716 It isn't 16x9, and I am not sure what it is.
1718 CONFIG_SHARP_LQ64D341
1720 Sharp LQ64D341 display, 640x480.
1721 Active, color, single scan.
1725 HLD1045 display, 640x480.
1726 Active, color, single scan.
1730 Optrex CBL50840-2 NF-FW 99 22 M5
1732 Hitachi LMG6912RPFC-00T
1736 320x240. Black & white.
1738 Normally display is black on white background; define
1739 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1741 CONFIG_LCD_ALIGNMENT
1743 Normally the LCD is page-aligned (tyically 4KB). If this is
1744 defined then the LCD will be aligned to this value instead.
1745 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1746 here, since it is cheaper to change data cache settings on
1747 a per-section basis.
1749 CONFIG_CONSOLE_SCROLL_LINES
1751 When the console need to be scrolled, this is the number of
1752 lines to scroll by. It defaults to 1. Increasing this makes
1753 the console jump but can help speed up operation when scrolling
1758 Support drawing of RLE8-compressed bitmaps on the LCD.
1762 Enables an 'i2c edid' command which can read EDID
1763 information over I2C from an attached LCD display.
1765 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1767 If this option is set, the environment is checked for
1768 a variable "splashimage". If found, the usual display
1769 of logo, copyright and system information on the LCD
1770 is suppressed and the BMP image at the address
1771 specified in "splashimage" is loaded instead. The
1772 console is redirected to the "nulldev", too. This
1773 allows for a "silent" boot where a splash screen is
1774 loaded very quickly after power-on.
1776 CONFIG_SPLASHIMAGE_GUARD
1778 If this option is set, then U-Boot will prevent the environment
1779 variable "splashimage" from being set to a problematic address
1780 (see README.displaying-bmps).
1781 This option is useful for targets where, due to alignment
1782 restrictions, an improperly aligned BMP image will cause a data
1783 abort. If you think you will not have problems with unaligned
1784 accesses (for example because your toolchain prevents them)
1785 there is no need to set this option.
1787 CONFIG_SPLASH_SCREEN_ALIGN
1789 If this option is set the splash image can be freely positioned
1790 on the screen. Environment variable "splashpos" specifies the
1791 position as "x,y". If a positive number is given it is used as
1792 number of pixel from left/top. If a negative number is given it
1793 is used as number of pixel from right/bottom. You can also
1794 specify 'm' for centering the image.
1797 setenv splashpos m,m
1798 => image at center of screen
1800 setenv splashpos 30,20
1801 => image at x = 30 and y = 20
1803 setenv splashpos -10,m
1804 => vertically centered image
1805 at x = dspWidth - bmpWidth - 9
1807 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1809 If this option is set, additionally to standard BMP
1810 images, gzipped BMP images can be displayed via the
1811 splashscreen support or the bmp command.
1813 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1815 If this option is set, 8-bit RLE compressed BMP images
1816 can be displayed via the splashscreen support or the
1819 - Do compresssing for memory range:
1822 If this option is set, it would use zlib deflate method
1823 to compress the specified memory at its best effort.
1825 - Compression support:
1828 Enabled by default to support gzip compressed images.
1832 If this option is set, support for bzip2 compressed
1833 images is included. If not, only uncompressed and gzip
1834 compressed images are supported.
1836 NOTE: the bzip2 algorithm requires a lot of RAM, so
1837 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1842 If this option is set, support for lzma compressed
1845 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1846 requires an amount of dynamic memory that is given by the
1849 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1851 Where lc and lp stand for, respectively, Literal context bits
1852 and Literal pos bits.
1854 This value is upper-bounded by 14MB in the worst case. Anyway,
1855 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1856 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1857 a very small buffer.
1859 Use the lzmainfo tool to determinate the lc and lp values and
1860 then calculate the amount of needed dynamic memory (ensuring
1861 the appropriate CONFIG_SYS_MALLOC_LEN value).
1865 If this option is set, support for LZO compressed images
1871 The address of PHY on MII bus.
1873 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1875 The clock frequency of the MII bus
1879 If this option is set, support for speed/duplex
1880 detection of gigabit PHY is included.
1882 CONFIG_PHY_RESET_DELAY
1884 Some PHY like Intel LXT971A need extra delay after
1885 reset before any MII register access is possible.
1886 For such PHY, set this option to the usec delay
1887 required. (minimum 300usec for LXT971A)
1889 CONFIG_PHY_CMD_DELAY (ppc4xx)
1891 Some PHY like Intel LXT971A need extra delay after
1892 command issued before MII status register can be read
1902 Define a default value for Ethernet address to use
1903 for the respective Ethernet interface, in case this
1904 is not determined automatically.
1909 Define a default value for the IP address to use for
1910 the default Ethernet interface, in case this is not
1911 determined through e.g. bootp.
1912 (Environment variable "ipaddr")
1914 - Server IP address:
1917 Defines a default value for the IP address of a TFTP
1918 server to contact when using the "tftboot" command.
1919 (Environment variable "serverip")
1921 CONFIG_KEEP_SERVERADDR
1923 Keeps the server's MAC address, in the env 'serveraddr'
1924 for passing to bootargs (like Linux's netconsole option)
1926 - Gateway IP address:
1929 Defines a default value for the IP address of the
1930 default router where packets to other networks are
1932 (Environment variable "gatewayip")
1937 Defines a default value for the subnet mask (or
1938 routing prefix) which is used to determine if an IP
1939 address belongs to the local subnet or needs to be
1940 forwarded through a router.
1941 (Environment variable "netmask")
1943 - Multicast TFTP Mode:
1946 Defines whether you want to support multicast TFTP as per
1947 rfc-2090; for example to work with atftp. Lets lots of targets
1948 tftp down the same boot image concurrently. Note: the Ethernet
1949 driver in use must provide a function: mcast() to join/leave a
1952 - BOOTP Recovery Mode:
1953 CONFIG_BOOTP_RANDOM_DELAY
1955 If you have many targets in a network that try to
1956 boot using BOOTP, you may want to avoid that all
1957 systems send out BOOTP requests at precisely the same
1958 moment (which would happen for instance at recovery
1959 from a power failure, when all systems will try to
1960 boot, thus flooding the BOOTP server. Defining
1961 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1962 inserted before sending out BOOTP requests. The
1963 following delays are inserted then:
1965 1st BOOTP request: delay 0 ... 1 sec
1966 2nd BOOTP request: delay 0 ... 2 sec
1967 3rd BOOTP request: delay 0 ... 4 sec
1969 BOOTP requests: delay 0 ... 8 sec
1971 - DHCP Advanced Options:
1972 You can fine tune the DHCP functionality by defining
1973 CONFIG_BOOTP_* symbols:
1975 CONFIG_BOOTP_SUBNETMASK
1976 CONFIG_BOOTP_GATEWAY
1977 CONFIG_BOOTP_HOSTNAME
1978 CONFIG_BOOTP_NISDOMAIN
1979 CONFIG_BOOTP_BOOTPATH
1980 CONFIG_BOOTP_BOOTFILESIZE
1983 CONFIG_BOOTP_SEND_HOSTNAME
1984 CONFIG_BOOTP_NTPSERVER
1985 CONFIG_BOOTP_TIMEOFFSET
1986 CONFIG_BOOTP_VENDOREX
1987 CONFIG_BOOTP_MAY_FAIL
1989 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1990 environment variable, not the BOOTP server.
1992 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1993 after the configured retry count, the call will fail
1994 instead of starting over. This can be used to fail over
1995 to Link-local IP address configuration if the DHCP server
1998 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1999 serverip from a DHCP server, it is possible that more
2000 than one DNS serverip is offered to the client.
2001 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
2002 serverip will be stored in the additional environment
2003 variable "dnsip2". The first DNS serverip is always
2004 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2007 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2008 to do a dynamic update of a DNS server. To do this, they
2009 need the hostname of the DHCP requester.
2010 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2011 of the "hostname" environment variable is passed as
2012 option 12 to the DHCP server.
2014 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2016 A 32bit value in microseconds for a delay between
2017 receiving a "DHCP Offer" and sending the "DHCP Request".
2018 This fixes a problem with certain DHCP servers that don't
2019 respond 100% of the time to a "DHCP request". E.g. On an
2020 AT91RM9200 processor running at 180MHz, this delay needed
2021 to be *at least* 15,000 usec before a Windows Server 2003
2022 DHCP server would reply 100% of the time. I recommend at
2023 least 50,000 usec to be safe. The alternative is to hope
2024 that one of the retries will be successful but note that
2025 the DHCP timeout and retry process takes a longer than
2028 - Link-local IP address negotiation:
2029 Negotiate with other link-local clients on the local network
2030 for an address that doesn't require explicit configuration.
2031 This is especially useful if a DHCP server cannot be guaranteed
2032 to exist in all environments that the device must operate.
2034 See doc/README.link-local for more information.
2037 CONFIG_CDP_DEVICE_ID
2039 The device id used in CDP trigger frames.
2041 CONFIG_CDP_DEVICE_ID_PREFIX
2043 A two character string which is prefixed to the MAC address
2048 A printf format string which contains the ascii name of
2049 the port. Normally is set to "eth%d" which sets
2050 eth0 for the first Ethernet, eth1 for the second etc.
2052 CONFIG_CDP_CAPABILITIES
2054 A 32bit integer which indicates the device capabilities;
2055 0x00000010 for a normal host which does not forwards.
2059 An ascii string containing the version of the software.
2063 An ascii string containing the name of the platform.
2067 A 32bit integer sent on the trigger.
2069 CONFIG_CDP_POWER_CONSUMPTION
2071 A 16bit integer containing the power consumption of the
2072 device in .1 of milliwatts.
2074 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2076 A byte containing the id of the VLAN.
2078 - Status LED: CONFIG_STATUS_LED
2080 Several configurations allow to display the current
2081 status using a LED. For instance, the LED will blink
2082 fast while running U-Boot code, stop blinking as
2083 soon as a reply to a BOOTP request was received, and
2084 start blinking slow once the Linux kernel is running
2085 (supported by a status LED driver in the Linux
2086 kernel). Defining CONFIG_STATUS_LED enables this
2092 The status LED can be connected to a GPIO pin.
2093 In such cases, the gpio_led driver can be used as a
2094 status LED backend implementation. Define CONFIG_GPIO_LED
2095 to include the gpio_led driver in the U-Boot binary.
2097 CONFIG_GPIO_LED_INVERTED_TABLE
2098 Some GPIO connected LEDs may have inverted polarity in which
2099 case the GPIO high value corresponds to LED off state and
2100 GPIO low value corresponds to LED on state.
2101 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2102 with a list of GPIO LEDs that have inverted polarity.
2104 - CAN Support: CONFIG_CAN_DRIVER
2106 Defining CONFIG_CAN_DRIVER enables CAN driver support
2107 on those systems that support this (optional)
2108 feature, like the TQM8xxL modules.
2110 - I2C Support: CONFIG_SYS_I2C
2112 This enable the NEW i2c subsystem, and will allow you to use
2113 i2c commands at the u-boot command line (as long as you set
2114 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2115 based realtime clock chips or other i2c devices. See
2116 common/cmd_i2c.c for a description of the command line
2119 ported i2c driver to the new framework:
2120 - drivers/i2c/soft_i2c.c:
2121 - activate first bus with CONFIG_SYS_I2C_SOFT define
2122 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2123 for defining speed and slave address
2124 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2125 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2126 for defining speed and slave address
2127 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2128 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2129 for defining speed and slave address
2130 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2131 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2132 for defining speed and slave address
2134 - drivers/i2c/fsl_i2c.c:
2135 - activate i2c driver with CONFIG_SYS_I2C_FSL
2136 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2137 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2138 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2140 - If your board supports a second fsl i2c bus, define
2141 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2142 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2143 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2146 - drivers/i2c/tegra_i2c.c:
2147 - activate this driver with CONFIG_SYS_I2C_TEGRA
2148 - This driver adds 4 i2c buses with a fix speed from
2149 100000 and the slave addr 0!
2151 - drivers/i2c/ppc4xx_i2c.c
2152 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2153 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2154 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2156 - drivers/i2c/i2c_mxc.c
2157 - activate this driver with CONFIG_SYS_I2C_MXC
2158 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2159 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2160 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2161 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2162 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2163 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2164 If thoses defines are not set, default value is 100000
2165 for speed, and 0 for slave.
2167 - drivers/i2c/rcar_i2c.c:
2168 - activate this driver with CONFIG_SYS_I2C_RCAR
2169 - This driver adds 4 i2c buses
2171 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2172 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2173 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2174 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2175 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2176 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2177 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2178 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2179 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2181 - drivers/i2c/sh_i2c.c:
2182 - activate this driver with CONFIG_SYS_I2C_SH
2183 - This driver adds from 2 to 5 i2c buses
2185 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2186 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2187 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2188 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2189 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2190 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2191 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2192 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2193 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2194 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2195 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2196 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2197 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2199 - drivers/i2c/omap24xx_i2c.c
2200 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2201 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2202 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2203 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2204 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2205 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2206 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2207 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2208 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2209 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2210 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2212 - drivers/i2c/zynq_i2c.c
2213 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2214 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2215 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2217 - drivers/i2c/s3c24x0_i2c.c:
2218 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2219 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2220 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2221 with a fix speed from 100000 and the slave addr 0!
2225 CONFIG_SYS_NUM_I2C_BUSES
2226 Hold the number of i2c busses you want to use. If you
2227 don't use/have i2c muxes on your i2c bus, this
2228 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2231 CONFIG_SYS_I2C_DIRECT_BUS
2232 define this, if you don't use i2c muxes on your hardware.
2233 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2236 CONFIG_SYS_I2C_MAX_HOPS
2237 define how many muxes are maximal consecutively connected
2238 on one i2c bus. If you not use i2c muxes, omit this
2241 CONFIG_SYS_I2C_BUSES
2242 hold a list of busses you want to use, only used if
2243 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2244 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2245 CONFIG_SYS_NUM_I2C_BUSES = 9:
2247 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2248 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2249 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2250 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2251 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2252 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2253 {1, {I2C_NULL_HOP}}, \
2254 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2255 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2259 bus 0 on adapter 0 without a mux
2260 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2261 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2262 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2263 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2264 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2265 bus 6 on adapter 1 without a mux
2266 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2267 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2269 If you do not have i2c muxes on your board, omit this define.
2271 - Legacy I2C Support: CONFIG_HARD_I2C
2273 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2274 provides the following compelling advantages:
2276 - more than one i2c adapter is usable
2277 - approved multibus support
2278 - better i2c mux support
2280 ** Please consider updating your I2C driver now. **
2282 These enable legacy I2C serial bus commands. Defining
2283 CONFIG_HARD_I2C will include the appropriate I2C driver
2284 for the selected CPU.
2286 This will allow you to use i2c commands at the u-boot
2287 command line (as long as you set CONFIG_CMD_I2C in
2288 CONFIG_COMMANDS) and communicate with i2c based realtime
2289 clock chips. See common/cmd_i2c.c for a description of the
2290 command line interface.
2292 CONFIG_HARD_I2C selects a hardware I2C controller.
2294 There are several other quantities that must also be
2295 defined when you define CONFIG_HARD_I2C.
2297 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2298 to be the frequency (in Hz) at which you wish your i2c bus
2299 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2300 the CPU's i2c node address).
2302 Now, the u-boot i2c code for the mpc8xx
2303 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2304 and so its address should therefore be cleared to 0 (See,
2305 eg, MPC823e User's Manual p.16-473). So, set
2306 CONFIG_SYS_I2C_SLAVE to 0.
2308 CONFIG_SYS_I2C_INIT_MPC5XXX
2310 When a board is reset during an i2c bus transfer
2311 chips might think that the current transfer is still
2312 in progress. Reset the slave devices by sending start
2313 commands until the slave device responds.
2315 That's all that's required for CONFIG_HARD_I2C.
2317 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2318 then the following macros need to be defined (examples are
2319 from include/configs/lwmon.h):
2323 (Optional). Any commands necessary to enable the I2C
2324 controller or configure ports.
2326 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2330 (Only for MPC8260 CPU). The I/O port to use (the code
2331 assumes both bits are on the same port). Valid values
2332 are 0..3 for ports A..D.
2336 The code necessary to make the I2C data line active
2337 (driven). If the data line is open collector, this
2340 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2344 The code necessary to make the I2C data line tri-stated
2345 (inactive). If the data line is open collector, this
2348 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2352 Code that returns true if the I2C data line is high,
2355 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2359 If <bit> is true, sets the I2C data line high. If it
2360 is false, it clears it (low).
2362 eg: #define I2C_SDA(bit) \
2363 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2364 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2368 If <bit> is true, sets the I2C clock line high. If it
2369 is false, it clears it (low).
2371 eg: #define I2C_SCL(bit) \
2372 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2373 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2377 This delay is invoked four times per clock cycle so this
2378 controls the rate of data transfer. The data rate thus
2379 is 1 / (I2C_DELAY * 4). Often defined to be something
2382 #define I2C_DELAY udelay(2)
2384 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2386 If your arch supports the generic GPIO framework (asm/gpio.h),
2387 then you may alternatively define the two GPIOs that are to be
2388 used as SCL / SDA. Any of the previous I2C_xxx macros will
2389 have GPIO-based defaults assigned to them as appropriate.
2391 You should define these to the GPIO value as given directly to
2392 the generic GPIO functions.
2394 CONFIG_SYS_I2C_INIT_BOARD
2396 When a board is reset during an i2c bus transfer
2397 chips might think that the current transfer is still
2398 in progress. On some boards it is possible to access
2399 the i2c SCLK line directly, either by using the
2400 processor pin as a GPIO or by having a second pin
2401 connected to the bus. If this option is defined a
2402 custom i2c_init_board() routine in boards/xxx/board.c
2403 is run early in the boot sequence.
2405 CONFIG_SYS_I2C_BOARD_LATE_INIT
2407 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2408 defined a custom i2c_board_late_init() routine in
2409 boards/xxx/board.c is run AFTER the operations in i2c_init()
2410 is completed. This callpoint can be used to unreset i2c bus
2411 using CPU i2c controller register accesses for CPUs whose i2c
2412 controller provide such a method. It is called at the end of
2413 i2c_init() to allow i2c_init operations to setup the i2c bus
2414 controller on the CPU (e.g. setting bus speed & slave address).
2416 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2418 This option enables configuration of bi_iic_fast[] flags
2419 in u-boot bd_info structure based on u-boot environment
2420 variable "i2cfast". (see also i2cfast)
2422 CONFIG_I2C_MULTI_BUS
2424 This option allows the use of multiple I2C buses, each of which
2425 must have a controller. At any point in time, only one bus is
2426 active. To switch to a different bus, use the 'i2c dev' command.
2427 Note that bus numbering is zero-based.
2429 CONFIG_SYS_I2C_NOPROBES
2431 This option specifies a list of I2C devices that will be skipped
2432 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2433 is set, specify a list of bus-device pairs. Otherwise, specify
2434 a 1D array of device addresses
2437 #undef CONFIG_I2C_MULTI_BUS
2438 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2440 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2442 #define CONFIG_I2C_MULTI_BUS
2443 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2445 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2447 CONFIG_SYS_SPD_BUS_NUM
2449 If defined, then this indicates the I2C bus number for DDR SPD.
2450 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2452 CONFIG_SYS_RTC_BUS_NUM
2454 If defined, then this indicates the I2C bus number for the RTC.
2455 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2457 CONFIG_SYS_DTT_BUS_NUM
2459 If defined, then this indicates the I2C bus number for the DTT.
2460 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2462 CONFIG_SYS_I2C_DTT_ADDR:
2464 If defined, specifies the I2C address of the DTT device.
2465 If not defined, then U-Boot uses predefined value for
2466 specified DTT device.
2468 CONFIG_SOFT_I2C_READ_REPEATED_START
2470 defining this will force the i2c_read() function in
2471 the soft_i2c driver to perform an I2C repeated start
2472 between writing the address pointer and reading the
2473 data. If this define is omitted the default behaviour
2474 of doing a stop-start sequence will be used. Most I2C
2475 devices can use either method, but some require one or
2478 - SPI Support: CONFIG_SPI
2480 Enables SPI driver (so far only tested with
2481 SPI EEPROM, also an instance works with Crystal A/D and
2482 D/As on the SACSng board)
2486 Enables the driver for SPI controller on SuperH. Currently
2487 only SH7757 is supported.
2491 Enables extended (16-bit) SPI EEPROM addressing.
2492 (symmetrical to CONFIG_I2C_X)
2496 Enables a software (bit-bang) SPI driver rather than
2497 using hardware support. This is a general purpose
2498 driver that only requires three general I/O port pins
2499 (two outputs, one input) to function. If this is
2500 defined, the board configuration must define several
2501 SPI configuration items (port pins to use, etc). For
2502 an example, see include/configs/sacsng.h.
2506 Enables a hardware SPI driver for general-purpose reads
2507 and writes. As with CONFIG_SOFT_SPI, the board configuration
2508 must define a list of chip-select function pointers.
2509 Currently supported on some MPC8xxx processors. For an
2510 example, see include/configs/mpc8349emds.h.
2514 Enables the driver for the SPI controllers on i.MX and MXC
2515 SoCs. Currently i.MX31/35/51 are supported.
2517 - FPGA Support: CONFIG_FPGA
2519 Enables FPGA subsystem.
2521 CONFIG_FPGA_<vendor>
2523 Enables support for specific chip vendors.
2526 CONFIG_FPGA_<family>
2528 Enables support for FPGA family.
2529 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2533 Specify the number of FPGA devices to support.
2535 CONFIG_SYS_FPGA_PROG_FEEDBACK
2537 Enable printing of hash marks during FPGA configuration.
2539 CONFIG_SYS_FPGA_CHECK_BUSY
2541 Enable checks on FPGA configuration interface busy
2542 status by the configuration function. This option
2543 will require a board or device specific function to
2548 If defined, a function that provides delays in the FPGA
2549 configuration driver.
2551 CONFIG_SYS_FPGA_CHECK_CTRLC
2552 Allow Control-C to interrupt FPGA configuration
2554 CONFIG_SYS_FPGA_CHECK_ERROR
2556 Check for configuration errors during FPGA bitfile
2557 loading. For example, abort during Virtex II
2558 configuration if the INIT_B line goes low (which
2559 indicated a CRC error).
2561 CONFIG_SYS_FPGA_WAIT_INIT
2563 Maximum time to wait for the INIT_B line to deassert
2564 after PROB_B has been deasserted during a Virtex II
2565 FPGA configuration sequence. The default time is 500
2568 CONFIG_SYS_FPGA_WAIT_BUSY
2570 Maximum time to wait for BUSY to deassert during
2571 Virtex II FPGA configuration. The default is 5 ms.
2573 CONFIG_SYS_FPGA_WAIT_CONFIG
2575 Time to wait after FPGA configuration. The default is
2578 - Configuration Management:
2581 If defined, this string will be added to the U-Boot
2582 version information (U_BOOT_VERSION)
2584 - Vendor Parameter Protection:
2586 U-Boot considers the values of the environment
2587 variables "serial#" (Board Serial Number) and
2588 "ethaddr" (Ethernet Address) to be parameters that
2589 are set once by the board vendor / manufacturer, and
2590 protects these variables from casual modification by
2591 the user. Once set, these variables are read-only,
2592 and write or delete attempts are rejected. You can
2593 change this behaviour:
2595 If CONFIG_ENV_OVERWRITE is #defined in your config
2596 file, the write protection for vendor parameters is
2597 completely disabled. Anybody can change or delete
2600 Alternatively, if you #define _both_ CONFIG_ETHADDR
2601 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2602 Ethernet address is installed in the environment,
2603 which can be changed exactly ONCE by the user. [The
2604 serial# is unaffected by this, i. e. it remains
2607 The same can be accomplished in a more flexible way
2608 for any variable by configuring the type of access
2609 to allow for those variables in the ".flags" variable
2610 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2615 Define this variable to enable the reservation of
2616 "protected RAM", i. e. RAM which is not overwritten
2617 by U-Boot. Define CONFIG_PRAM to hold the number of
2618 kB you want to reserve for pRAM. You can overwrite
2619 this default value by defining an environment
2620 variable "pram" to the number of kB you want to
2621 reserve. Note that the board info structure will
2622 still show the full amount of RAM. If pRAM is
2623 reserved, a new environment variable "mem" will
2624 automatically be defined to hold the amount of
2625 remaining RAM in a form that can be passed as boot
2626 argument to Linux, for instance like that:
2628 setenv bootargs ... mem=\${mem}
2631 This way you can tell Linux not to use this memory,
2632 either, which results in a memory region that will
2633 not be affected by reboots.
2635 *WARNING* If your board configuration uses automatic
2636 detection of the RAM size, you must make sure that
2637 this memory test is non-destructive. So far, the
2638 following board configurations are known to be
2641 IVMS8, IVML24, SPD8xx, TQM8xxL,
2642 HERMES, IP860, RPXlite, LWMON,
2645 - Access to physical memory region (> 4GB)
2646 Some basic support is provided for operations on memory not
2647 normally accessible to U-Boot - e.g. some architectures
2648 support access to more than 4GB of memory on 32-bit
2649 machines using physical address extension or similar.
2650 Define CONFIG_PHYSMEM to access this basic support, which
2651 currently only supports clearing the memory.
2656 Define this variable to stop the system in case of a
2657 fatal error, so that you have to reset it manually.
2658 This is probably NOT a good idea for an embedded
2659 system where you want the system to reboot
2660 automatically as fast as possible, but it may be
2661 useful during development since you can try to debug
2662 the conditions that lead to the situation.
2664 CONFIG_NET_RETRY_COUNT
2666 This variable defines the number of retries for
2667 network operations like ARP, RARP, TFTP, or BOOTP
2668 before giving up the operation. If not defined, a
2669 default value of 5 is used.
2673 Timeout waiting for an ARP reply in milliseconds.
2677 Timeout in milliseconds used in NFS protocol.
2678 If you encounter "ERROR: Cannot umount" in nfs command,
2679 try longer timeout such as
2680 #define CONFIG_NFS_TIMEOUT 10000UL
2682 - Command Interpreter:
2683 CONFIG_AUTO_COMPLETE
2685 Enable auto completion of commands using TAB.
2687 Note that this feature has NOT been implemented yet
2688 for the "hush" shell.
2691 CONFIG_SYS_HUSH_PARSER
2693 Define this variable to enable the "hush" shell (from
2694 Busybox) as command line interpreter, thus enabling
2695 powerful command line syntax like
2696 if...then...else...fi conditionals or `&&' and '||'
2697 constructs ("shell scripts").
2699 If undefined, you get the old, much simpler behaviour
2700 with a somewhat smaller memory footprint.
2703 CONFIG_SYS_PROMPT_HUSH_PS2
2705 This defines the secondary prompt string, which is
2706 printed when the command interpreter needs more input
2707 to complete a command. Usually "> ".
2711 In the current implementation, the local variables
2712 space and global environment variables space are
2713 separated. Local variables are those you define by
2714 simply typing `name=value'. To access a local
2715 variable later on, you have write `$name' or
2716 `${name}'; to execute the contents of a variable
2717 directly type `$name' at the command prompt.
2719 Global environment variables are those you use
2720 setenv/printenv to work with. To run a command stored
2721 in such a variable, you need to use the run command,
2722 and you must not use the '$' sign to access them.
2724 To store commands and special characters in a
2725 variable, please use double quotation marks
2726 surrounding the whole text of the variable, instead
2727 of the backslashes before semicolons and special
2730 - Commandline Editing and History:
2731 CONFIG_CMDLINE_EDITING
2733 Enable editing and History functions for interactive
2734 commandline input operations
2736 - Default Environment:
2737 CONFIG_EXTRA_ENV_SETTINGS
2739 Define this to contain any number of null terminated
2740 strings (variable = value pairs) that will be part of
2741 the default environment compiled into the boot image.
2743 For example, place something like this in your
2744 board's config file:
2746 #define CONFIG_EXTRA_ENV_SETTINGS \
2750 Warning: This method is based on knowledge about the
2751 internal format how the environment is stored by the
2752 U-Boot code. This is NOT an official, exported
2753 interface! Although it is unlikely that this format
2754 will change soon, there is no guarantee either.
2755 You better know what you are doing here.
2757 Note: overly (ab)use of the default environment is
2758 discouraged. Make sure to check other ways to preset
2759 the environment like the "source" command or the
2762 CONFIG_ENV_VARS_UBOOT_CONFIG
2764 Define this in order to add variables describing the
2765 U-Boot build configuration to the default environment.
2766 These will be named arch, cpu, board, vendor, and soc.
2768 Enabling this option will cause the following to be defined:
2776 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2778 Define this in order to add variables describing certain
2779 run-time determined information about the hardware to the
2780 environment. These will be named board_name, board_rev.
2782 CONFIG_DELAY_ENVIRONMENT
2784 Normally the environment is loaded when the board is
2785 intialised so that it is available to U-Boot. This inhibits
2786 that so that the environment is not available until
2787 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2788 this is instead controlled by the value of
2789 /config/load-environment.
2791 - DataFlash Support:
2792 CONFIG_HAS_DATAFLASH
2794 Defining this option enables DataFlash features and
2795 allows to read/write in Dataflash via the standard
2798 - Serial Flash support
2801 Defining this option enables SPI flash commands
2802 'sf probe/read/write/erase/update'.
2804 Usage requires an initial 'probe' to define the serial
2805 flash parameters, followed by read/write/erase/update
2808 The following defaults may be provided by the platform
2809 to handle the common case when only a single serial
2810 flash is present on the system.
2812 CONFIG_SF_DEFAULT_BUS Bus identifier
2813 CONFIG_SF_DEFAULT_CS Chip-select
2814 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2815 CONFIG_SF_DEFAULT_SPEED in Hz
2819 Define this option to include a destructive SPI flash
2822 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2824 Define this option to use the Bank addr/Extended addr
2825 support on SPI flashes which has size > 16Mbytes.
2827 CONFIG_SF_DUAL_FLASH Dual flash memories
2829 Define this option to use dual flash support where two flash
2830 memories can be connected with a given cs line.
2831 currently Xilinx Zynq qspi support these type of connections.
2833 - SystemACE Support:
2836 Adding this option adds support for Xilinx SystemACE
2837 chips attached via some sort of local bus. The address
2838 of the chip must also be defined in the
2839 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2841 #define CONFIG_SYSTEMACE
2842 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2844 When SystemACE support is added, the "ace" device type
2845 becomes available to the fat commands, i.e. fatls.
2847 - TFTP Fixed UDP Port:
2850 If this is defined, the environment variable tftpsrcp
2851 is used to supply the TFTP UDP source port value.
2852 If tftpsrcp isn't defined, the normal pseudo-random port
2853 number generator is used.
2855 Also, the environment variable tftpdstp is used to supply
2856 the TFTP UDP destination port value. If tftpdstp isn't
2857 defined, the normal port 69 is used.
2859 The purpose for tftpsrcp is to allow a TFTP server to
2860 blindly start the TFTP transfer using the pre-configured
2861 target IP address and UDP port. This has the effect of
2862 "punching through" the (Windows XP) firewall, allowing
2863 the remainder of the TFTP transfer to proceed normally.
2864 A better solution is to properly configure the firewall,
2865 but sometimes that is not allowed.
2870 This enables a generic 'hash' command which can produce
2871 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2875 Enable the hash verify command (hash -v). This adds to code
2878 CONFIG_SHA1 - support SHA1 hashing
2879 CONFIG_SHA256 - support SHA256 hashing
2881 Note: There is also a sha1sum command, which should perhaps
2882 be deprecated in favour of 'hash sha1'.
2884 - Freescale i.MX specific commands:
2885 CONFIG_CMD_HDMIDETECT
2886 This enables 'hdmidet' command which returns true if an
2887 HDMI monitor is detected. This command is i.MX 6 specific.
2890 This enables the 'bmode' (bootmode) command for forcing
2891 a boot from specific media.
2893 This is useful for forcing the ROM's usb downloader to
2894 activate upon a watchdog reset which is nice when iterating
2895 on U-Boot. Using the reset button or running bmode normal
2896 will set it back to normal. This command currently
2897 supports i.MX53 and i.MX6.
2902 This enables the RSA algorithm used for FIT image verification
2903 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2905 The signing part is build into mkimage regardless of this
2908 - bootcount support:
2909 CONFIG_BOOTCOUNT_LIMIT
2911 This enables the bootcounter support, see:
2912 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2915 enable special bootcounter support on at91sam9xe based boards.
2917 enable special bootcounter support on blackfin based boards.
2919 enable special bootcounter support on da850 based boards.
2920 CONFIG_BOOTCOUNT_RAM
2921 enable support for the bootcounter in RAM
2922 CONFIG_BOOTCOUNT_I2C
2923 enable support for the bootcounter on an i2c (like RTC) device.
2924 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2925 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2927 CONFIG_BOOTCOUNT_ALEN = address len
2929 - Show boot progress:
2930 CONFIG_SHOW_BOOT_PROGRESS
2932 Defining this option allows to add some board-
2933 specific code (calling a user-provided function
2934 "show_boot_progress(int)") that enables you to show
2935 the system's boot progress on some display (for
2936 example, some LED's) on your board. At the moment,
2937 the following checkpoints are implemented:
2939 - Detailed boot stage timing
2941 Define this option to get detailed timing of each stage
2942 of the boot process.
2944 CONFIG_BOOTSTAGE_USER_COUNT
2945 This is the number of available user bootstage records.
2946 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2947 a new ID will be allocated from this stash. If you exceed
2948 the limit, recording will stop.
2950 CONFIG_BOOTSTAGE_REPORT
2951 Define this to print a report before boot, similar to this:
2953 Timer summary in microseconds:
2956 3,575,678 3,575,678 board_init_f start
2957 3,575,695 17 arch_cpu_init A9
2958 3,575,777 82 arch_cpu_init done
2959 3,659,598 83,821 board_init_r start
2960 3,910,375 250,777 main_loop
2961 29,916,167 26,005,792 bootm_start
2962 30,361,327 445,160 start_kernel
2964 CONFIG_CMD_BOOTSTAGE
2965 Add a 'bootstage' command which supports printing a report
2966 and un/stashing of bootstage data.
2968 CONFIG_BOOTSTAGE_FDT
2969 Stash the bootstage information in the FDT. A root 'bootstage'
2970 node is created with each bootstage id as a child. Each child
2971 has a 'name' property and either 'mark' containing the
2972 mark time in microsecond, or 'accum' containing the
2973 accumulated time for that bootstage id in microseconds.
2978 name = "board_init_f";
2987 Code in the Linux kernel can find this in /proc/devicetree.
2989 Legacy uImage format:
2992 1 common/cmd_bootm.c before attempting to boot an image
2993 -1 common/cmd_bootm.c Image header has bad magic number
2994 2 common/cmd_bootm.c Image header has correct magic number
2995 -2 common/cmd_bootm.c Image header has bad checksum
2996 3 common/cmd_bootm.c Image header has correct checksum
2997 -3 common/cmd_bootm.c Image data has bad checksum
2998 4 common/cmd_bootm.c Image data has correct checksum
2999 -4 common/cmd_bootm.c Image is for unsupported architecture
3000 5 common/cmd_bootm.c Architecture check OK
3001 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
3002 6 common/cmd_bootm.c Image Type check OK
3003 -6 common/cmd_bootm.c gunzip uncompression error
3004 -7 common/cmd_bootm.c Unimplemented compression type
3005 7 common/cmd_bootm.c Uncompression OK
3006 8 common/cmd_bootm.c No uncompress/copy overwrite error
3007 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3009 9 common/image.c Start initial ramdisk verification
3010 -10 common/image.c Ramdisk header has bad magic number
3011 -11 common/image.c Ramdisk header has bad checksum
3012 10 common/image.c Ramdisk header is OK
3013 -12 common/image.c Ramdisk data has bad checksum
3014 11 common/image.c Ramdisk data has correct checksum
3015 12 common/image.c Ramdisk verification complete, start loading
3016 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3017 13 common/image.c Start multifile image verification
3018 14 common/image.c No initial ramdisk, no multifile, continue.
3020 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3022 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3023 -31 post/post.c POST test failed, detected by post_output_backlog()
3024 -32 post/post.c POST test failed, detected by post_run_single()
3026 34 common/cmd_doc.c before loading a Image from a DOC device
3027 -35 common/cmd_doc.c Bad usage of "doc" command
3028 35 common/cmd_doc.c correct usage of "doc" command
3029 -36 common/cmd_doc.c No boot device
3030 36 common/cmd_doc.c correct boot device
3031 -37 common/cmd_doc.c Unknown Chip ID on boot device
3032 37 common/cmd_doc.c correct chip ID found, device available
3033 -38 common/cmd_doc.c Read Error on boot device
3034 38 common/cmd_doc.c reading Image header from DOC device OK
3035 -39 common/cmd_doc.c Image header has bad magic number
3036 39 common/cmd_doc.c Image header has correct magic number
3037 -40 common/cmd_doc.c Error reading Image from DOC device
3038 40 common/cmd_doc.c Image header has correct magic number
3039 41 common/cmd_ide.c before loading a Image from a IDE device
3040 -42 common/cmd_ide.c Bad usage of "ide" command
3041 42 common/cmd_ide.c correct usage of "ide" command
3042 -43 common/cmd_ide.c No boot device
3043 43 common/cmd_ide.c boot device found
3044 -44 common/cmd_ide.c Device not available
3045 44 common/cmd_ide.c Device available
3046 -45 common/cmd_ide.c wrong partition selected
3047 45 common/cmd_ide.c partition selected
3048 -46 common/cmd_ide.c Unknown partition table
3049 46 common/cmd_ide.c valid partition table found
3050 -47 common/cmd_ide.c Invalid partition type
3051 47 common/cmd_ide.c correct partition type
3052 -48 common/cmd_ide.c Error reading Image Header on boot device
3053 48 common/cmd_ide.c reading Image Header from IDE device OK
3054 -49 common/cmd_ide.c Image header has bad magic number
3055 49 common/cmd_ide.c Image header has correct magic number
3056 -50 common/cmd_ide.c Image header has bad checksum
3057 50 common/cmd_ide.c Image header has correct checksum
3058 -51 common/cmd_ide.c Error reading Image from IDE device
3059 51 common/cmd_ide.c reading Image from IDE device OK
3060 52 common/cmd_nand.c before loading a Image from a NAND device
3061 -53 common/cmd_nand.c Bad usage of "nand" command
3062 53 common/cmd_nand.c correct usage of "nand" command
3063 -54 common/cmd_nand.c No boot device
3064 54 common/cmd_nand.c boot device found
3065 -55 common/cmd_nand.c Unknown Chip ID on boot device
3066 55 common/cmd_nand.c correct chip ID found, device available
3067 -56 common/cmd_nand.c Error reading Image Header on boot device
3068 56 common/cmd_nand.c reading Image Header from NAND device OK
3069 -57 common/cmd_nand.c Image header has bad magic number
3070 57 common/cmd_nand.c Image header has correct magic number
3071 -58 common/cmd_nand.c Error reading Image from NAND device
3072 58 common/cmd_nand.c reading Image from NAND device OK
3074 -60 common/env_common.c Environment has a bad CRC, using default
3076 64 net/eth.c starting with Ethernet configuration.
3077 -64 net/eth.c no Ethernet found.
3078 65 net/eth.c Ethernet found.
3080 -80 common/cmd_net.c usage wrong
3081 80 common/cmd_net.c before calling NetLoop()
3082 -81 common/cmd_net.c some error in NetLoop() occurred
3083 81 common/cmd_net.c NetLoop() back without error
3084 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3085 82 common/cmd_net.c trying automatic boot
3086 83 common/cmd_net.c running "source" command
3087 -83 common/cmd_net.c some error in automatic boot or "source" command
3088 84 common/cmd_net.c end without errors
3093 100 common/cmd_bootm.c Kernel FIT Image has correct format
3094 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3095 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3096 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3097 102 common/cmd_bootm.c Kernel unit name specified
3098 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3099 103 common/cmd_bootm.c Found configuration node
3100 104 common/cmd_bootm.c Got kernel subimage node offset
3101 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3102 105 common/cmd_bootm.c Kernel subimage hash verification OK
3103 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3104 106 common/cmd_bootm.c Architecture check OK
3105 -106 common/cmd_bootm.c Kernel subimage has wrong type
3106 107 common/cmd_bootm.c Kernel subimage type OK
3107 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3108 108 common/cmd_bootm.c Got kernel subimage data/size
3109 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3110 -109 common/cmd_bootm.c Can't get kernel subimage type
3111 -110 common/cmd_bootm.c Can't get kernel subimage comp
3112 -111 common/cmd_bootm.c Can't get kernel subimage os
3113 -112 common/cmd_bootm.c Can't get kernel subimage load address
3114 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3116 120 common/image.c Start initial ramdisk verification
3117 -120 common/image.c Ramdisk FIT image has incorrect format
3118 121 common/image.c Ramdisk FIT image has correct format
3119 122 common/image.c No ramdisk subimage unit name, using configuration
3120 -122 common/image.c Can't get configuration for ramdisk subimage
3121 123 common/image.c Ramdisk unit name specified
3122 -124 common/image.c Can't get ramdisk subimage node offset
3123 125 common/image.c Got ramdisk subimage node offset
3124 -125 common/image.c Ramdisk subimage hash verification failed
3125 126 common/image.c Ramdisk subimage hash verification OK
3126 -126 common/image.c Ramdisk subimage for unsupported architecture
3127 127 common/image.c Architecture check OK
3128 -127 common/image.c Can't get ramdisk subimage data/size
3129 128 common/image.c Got ramdisk subimage data/size
3130 129 common/image.c Can't get ramdisk load address
3131 -129 common/image.c Got ramdisk load address
3133 -130 common/cmd_doc.c Incorrect FIT image format
3134 131 common/cmd_doc.c FIT image format OK
3136 -140 common/cmd_ide.c Incorrect FIT image format
3137 141 common/cmd_ide.c FIT image format OK
3139 -150 common/cmd_nand.c Incorrect FIT image format
3140 151 common/cmd_nand.c FIT image format OK
3142 - FIT image support:
3144 Enable support for the FIT uImage format.
3146 CONFIG_FIT_BEST_MATCH
3147 When no configuration is explicitly selected, default to the
3148 one whose fdt's compatibility field best matches that of
3149 U-Boot itself. A match is considered "best" if it matches the
3150 most specific compatibility entry of U-Boot's fdt's root node.
3151 The order of entries in the configuration's fdt is ignored.
3153 CONFIG_FIT_SIGNATURE
3154 This option enables signature verification of FIT uImages,
3155 using a hash signed and verified using RSA. See
3156 doc/uImage.FIT/signature.txt for more details.
3158 - Standalone program support:
3159 CONFIG_STANDALONE_LOAD_ADDR
3161 This option defines a board specific value for the
3162 address where standalone program gets loaded, thus
3163 overwriting the architecture dependent default
3166 - Frame Buffer Address:
3169 Define CONFIG_FB_ADDR if you want to use specific
3170 address for frame buffer. This is typically the case
3171 when using a graphics controller has separate video
3172 memory. U-Boot will then place the frame buffer at
3173 the given address instead of dynamically reserving it
3174 in system RAM by calling lcd_setmem(), which grabs
3175 the memory for the frame buffer depending on the
3176 configured panel size.
3178 Please see board_init_f function.
3180 - Automatic software updates via TFTP server
3182 CONFIG_UPDATE_TFTP_CNT_MAX
3183 CONFIG_UPDATE_TFTP_MSEC_MAX
3185 These options enable and control the auto-update feature;
3186 for a more detailed description refer to doc/README.update.
3188 - MTD Support (mtdparts command, UBI support)
3191 Adds the MTD device infrastructure from the Linux kernel.
3192 Needed for mtdparts command support.
3194 CONFIG_MTD_PARTITIONS
3196 Adds the MTD partitioning infrastructure from the Linux
3197 kernel. Needed for UBI support.
3202 Adds commands for interacting with MTD partitions formatted
3203 with the UBI flash translation layer
3205 Requires also defining CONFIG_RBTREE
3207 CONFIG_UBI_SILENCE_MSG
3209 Make the verbose messages from UBI stop printing. This leaves
3210 warnings and errors enabled.
3215 Adds commands for interacting with UBI volumes formatted as
3216 UBIFS. UBIFS is read-only in u-boot.
3218 Requires UBI support as well as CONFIG_LZO
3220 CONFIG_UBIFS_SILENCE_MSG
3222 Make the verbose messages from UBIFS stop printing. This leaves
3223 warnings and errors enabled.
3227 Enable building of SPL globally.
3230 LDSCRIPT for linking the SPL binary.
3232 CONFIG_SPL_MAX_FOOTPRINT
3233 Maximum size in memory allocated to the SPL, BSS included.
3234 When defined, the linker checks that the actual memory
3235 used by SPL from _start to __bss_end does not exceed it.
3236 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3237 must not be both defined at the same time.
3240 Maximum size of the SPL image (text, data, rodata, and
3241 linker lists sections), BSS excluded.
3242 When defined, the linker checks that the actual size does
3245 CONFIG_SPL_TEXT_BASE
3246 TEXT_BASE for linking the SPL binary.
3248 CONFIG_SPL_RELOC_TEXT_BASE
3249 Address to relocate to. If unspecified, this is equal to
3250 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3252 CONFIG_SPL_BSS_START_ADDR
3253 Link address for the BSS within the SPL binary.
3255 CONFIG_SPL_BSS_MAX_SIZE
3256 Maximum size in memory allocated to the SPL BSS.
3257 When defined, the linker checks that the actual memory used
3258 by SPL from __bss_start to __bss_end does not exceed it.
3259 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3260 must not be both defined at the same time.
3263 Adress of the start of the stack SPL will use
3265 CONFIG_SPL_RELOC_STACK
3266 Adress of the start of the stack SPL will use after
3267 relocation. If unspecified, this is equal to
3270 CONFIG_SYS_SPL_MALLOC_START
3271 Starting address of the malloc pool used in SPL.
3273 CONFIG_SYS_SPL_MALLOC_SIZE
3274 The size of the malloc pool used in SPL.
3276 CONFIG_SPL_FRAMEWORK
3277 Enable the SPL framework under common/. This framework
3278 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3279 NAND loading of the Linux Kernel.
3281 CONFIG_SPL_DISPLAY_PRINT
3282 For ARM, enable an optional function to print more information
3283 about the running system.
3285 CONFIG_SPL_INIT_MINIMAL
3286 Arch init code should be built for a very small image
3288 CONFIG_SPL_LIBCOMMON_SUPPORT
3289 Support for common/libcommon.o in SPL binary
3291 CONFIG_SPL_LIBDISK_SUPPORT
3292 Support for disk/libdisk.o in SPL binary
3294 CONFIG_SPL_I2C_SUPPORT
3295 Support for drivers/i2c/libi2c.o in SPL binary
3297 CONFIG_SPL_GPIO_SUPPORT
3298 Support for drivers/gpio/libgpio.o in SPL binary
3300 CONFIG_SPL_MMC_SUPPORT
3301 Support for drivers/mmc/libmmc.o in SPL binary
3303 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3304 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3305 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3306 Address, size and partition on the MMC to load U-Boot from
3307 when the MMC is being used in raw mode.
3309 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3310 Sector to load kernel uImage from when MMC is being
3311 used in raw mode (for Falcon mode)
3313 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3314 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3315 Sector and number of sectors to load kernel argument
3316 parameters from when MMC is being used in raw mode
3319 CONFIG_SPL_FAT_SUPPORT
3320 Support for fs/fat/libfat.o in SPL binary
3322 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3323 Filename to read to load U-Boot when reading from FAT
3325 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3326 Filename to read to load kernel uImage when reading
3327 from FAT (for Falcon mode)
3329 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3330 Filename to read to load kernel argument parameters
3331 when reading from FAT (for Falcon mode)
3333 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3334 Set this for NAND SPL on PPC mpc83xx targets, so that
3335 start.S waits for the rest of the SPL to load before
3336 continuing (the hardware starts execution after just
3337 loading the first page rather than the full 4K).
3339 CONFIG_SPL_SKIP_RELOCATE
3340 Avoid SPL relocation
3342 CONFIG_SPL_NAND_BASE
3343 Include nand_base.c in the SPL. Requires
3344 CONFIG_SPL_NAND_DRIVERS.
3346 CONFIG_SPL_NAND_DRIVERS
3347 SPL uses normal NAND drivers, not minimal drivers.
3350 Include standard software ECC in the SPL
3352 CONFIG_SPL_NAND_SIMPLE
3353 Support for NAND boot using simple NAND drivers that
3354 expose the cmd_ctrl() interface.
3356 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3357 Set for the SPL on PPC mpc8xxx targets, support for
3358 drivers/ddr/fsl/libddr.o in SPL binary.
3360 CONFIG_SPL_COMMON_INIT_DDR
3361 Set for common ddr init with serial presence detect in
3364 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3365 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3366 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3367 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3368 CONFIG_SYS_NAND_ECCBYTES
3369 Defines the size and behavior of the NAND that SPL uses
3372 CONFIG_SPL_NAND_BOOT
3373 Add support NAND boot
3375 CONFIG_SYS_NAND_U_BOOT_OFFS
3376 Location in NAND to read U-Boot from
3378 CONFIG_SYS_NAND_U_BOOT_DST
3379 Location in memory to load U-Boot to
3381 CONFIG_SYS_NAND_U_BOOT_SIZE
3382 Size of image to load
3384 CONFIG_SYS_NAND_U_BOOT_START
3385 Entry point in loaded image to jump to
3387 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3388 Define this if you need to first read the OOB and then the
3389 data. This is used for example on davinci plattforms.
3391 CONFIG_SPL_OMAP3_ID_NAND
3392 Support for an OMAP3-specific set of functions to return the
3393 ID and MFR of the first attached NAND chip, if present.
3395 CONFIG_SPL_SERIAL_SUPPORT
3396 Support for drivers/serial/libserial.o in SPL binary
3398 CONFIG_SPL_SPI_FLASH_SUPPORT
3399 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3401 CONFIG_SPL_SPI_SUPPORT
3402 Support for drivers/spi/libspi.o in SPL binary
3404 CONFIG_SPL_RAM_DEVICE
3405 Support for running image already present in ram, in SPL binary
3407 CONFIG_SPL_LIBGENERIC_SUPPORT
3408 Support for lib/libgeneric.o in SPL binary
3410 CONFIG_SPL_ENV_SUPPORT
3411 Support for the environment operating in SPL binary
3413 CONFIG_SPL_NET_SUPPORT
3414 Support for the net/libnet.o in SPL binary.
3415 It conflicts with SPL env from storage medium specified by
3416 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3419 Image offset to which the SPL should be padded before appending
3420 the SPL payload. By default, this is defined as
3421 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3422 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3423 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3426 Final target image containing SPL and payload. Some SPLs
3427 use an arch-specific makefile fragment instead, for
3428 example if more than one image needs to be produced.
3430 CONFIG_FIT_SPL_PRINT
3431 Printing information about a FIT image adds quite a bit of
3432 code to SPL. So this is normally disabled in SPL. Use this
3433 option to re-enable it. This will affect the output of the
3434 bootm command when booting a FIT image.
3438 Enable building of TPL globally.
3441 Image offset to which the TPL should be padded before appending
3442 the TPL payload. By default, this is defined as
3443 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3444 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3445 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3450 [so far only for SMDK2400 boards]
3452 - Modem support enable:
3453 CONFIG_MODEM_SUPPORT
3455 - RTS/CTS Flow control enable:
3458 - Modem debug support:
3459 CONFIG_MODEM_SUPPORT_DEBUG
3461 Enables debugging stuff (char screen[1024], dbg())
3462 for modem support. Useful only with BDI2000.
3464 - Interrupt support (PPC):
3466 There are common interrupt_init() and timer_interrupt()
3467 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3468 for CPU specific initialization. interrupt_init_cpu()
3469 should set decrementer_count to appropriate value. If
3470 CPU resets decrementer automatically after interrupt
3471 (ppc4xx) it should set decrementer_count to zero.
3472 timer_interrupt() calls timer_interrupt_cpu() for CPU
3473 specific handling. If board has watchdog / status_led
3474 / other_activity_monitor it works automatically from
3475 general timer_interrupt().
3479 In the target system modem support is enabled when a
3480 specific key (key combination) is pressed during
3481 power-on. Otherwise U-Boot will boot normally
3482 (autoboot). The key_pressed() function is called from
3483 board_init(). Currently key_pressed() is a dummy
3484 function, returning 1 and thus enabling modem
3487 If there are no modem init strings in the
3488 environment, U-Boot proceed to autoboot; the
3489 previous output (banner, info printfs) will be
3492 See also: doc/README.Modem
3494 Board initialization settings:
3495 ------------------------------
3497 During Initialization u-boot calls a number of board specific functions
3498 to allow the preparation of board specific prerequisites, e.g. pin setup
3499 before drivers are initialized. To enable these callbacks the
3500 following configuration macros have to be defined. Currently this is
3501 architecture specific, so please check arch/your_architecture/lib/board.c
3502 typically in board_init_f() and board_init_r().
3504 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3505 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3506 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3507 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3509 Configuration Settings:
3510 -----------------------
3512 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3513 Optionally it can be defined to support 64-bit memory commands.
3515 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3516 undefine this when you're short of memory.
3518 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3519 width of the commands listed in the 'help' command output.
3521 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3522 prompt for user input.
3524 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3526 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3528 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3530 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3531 the application (usually a Linux kernel) when it is
3534 - CONFIG_SYS_BAUDRATE_TABLE:
3535 List of legal baudrate settings for this board.
3537 - CONFIG_SYS_CONSOLE_INFO_QUIET
3538 Suppress display of console information at boot.
3540 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3541 If the board specific function
3542 extern int overwrite_console (void);
3543 returns 1, the stdin, stderr and stdout are switched to the
3544 serial port, else the settings in the environment are used.
3546 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3547 Enable the call to overwrite_console().
3549 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3550 Enable overwrite of previous console environment settings.
3552 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3553 Begin and End addresses of the area used by the
3556 - CONFIG_SYS_ALT_MEMTEST:
3557 Enable an alternate, more extensive memory test.
3559 - CONFIG_SYS_MEMTEST_SCRATCH:
3560 Scratch address used by the alternate memory test
3561 You only need to set this if address zero isn't writeable
3563 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3564 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3565 this specified memory area will get subtracted from the top
3566 (end) of RAM and won't get "touched" at all by U-Boot. By
3567 fixing up gd->ram_size the Linux kernel should gets passed
3568 the now "corrected" memory size and won't touch it either.
3569 This should work for arch/ppc and arch/powerpc. Only Linux
3570 board ports in arch/powerpc with bootwrapper support that
3571 recalculate the memory size from the SDRAM controller setup
3572 will have to get fixed in Linux additionally.
3574 This option can be used as a workaround for the 440EPx/GRx
3575 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3578 WARNING: Please make sure that this value is a multiple of
3579 the Linux page size (normally 4k). If this is not the case,
3580 then the end address of the Linux memory will be located at a
3581 non page size aligned address and this could cause major
3584 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3585 Enable temporary baudrate change while serial download
3587 - CONFIG_SYS_SDRAM_BASE:
3588 Physical start address of SDRAM. _Must_ be 0 here.
3590 - CONFIG_SYS_MBIO_BASE:
3591 Physical start address of Motherboard I/O (if using a
3594 - CONFIG_SYS_FLASH_BASE:
3595 Physical start address of Flash memory.
3597 - CONFIG_SYS_MONITOR_BASE:
3598 Physical start address of boot monitor code (set by
3599 make config files to be same as the text base address
3600 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3601 CONFIG_SYS_FLASH_BASE when booting from flash.
3603 - CONFIG_SYS_MONITOR_LEN:
3604 Size of memory reserved for monitor code, used to
3605 determine _at_compile_time_ (!) if the environment is
3606 embedded within the U-Boot image, or in a separate
3609 - CONFIG_SYS_MALLOC_LEN:
3610 Size of DRAM reserved for malloc() use.
3612 - CONFIG_SYS_BOOTM_LEN:
3613 Normally compressed uImages are limited to an
3614 uncompressed size of 8 MBytes. If this is not enough,
3615 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3616 to adjust this setting to your needs.
3618 - CONFIG_SYS_BOOTMAPSZ:
3619 Maximum size of memory mapped by the startup code of
3620 the Linux kernel; all data that must be processed by
3621 the Linux kernel (bd_info, boot arguments, FDT blob if
3622 used) must be put below this limit, unless "bootm_low"
3623 environment variable is defined and non-zero. In such case
3624 all data for the Linux kernel must be between "bootm_low"
3625 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3626 variable "bootm_mapsize" will override the value of
3627 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3628 then the value in "bootm_size" will be used instead.
3630 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3631 Enable initrd_high functionality. If defined then the
3632 initrd_high feature is enabled and the bootm ramdisk subcommand
3635 - CONFIG_SYS_BOOT_GET_CMDLINE:
3636 Enables allocating and saving kernel cmdline in space between
3637 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3639 - CONFIG_SYS_BOOT_GET_KBD:
3640 Enables allocating and saving a kernel copy of the bd_info in
3641 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3643 - CONFIG_SYS_MAX_FLASH_BANKS:
3644 Max number of Flash memory banks
3646 - CONFIG_SYS_MAX_FLASH_SECT:
3647 Max number of sectors on a Flash chip
3649 - CONFIG_SYS_FLASH_ERASE_TOUT:
3650 Timeout for Flash erase operations (in ms)
3652 - CONFIG_SYS_FLASH_WRITE_TOUT:
3653 Timeout for Flash write operations (in ms)
3655 - CONFIG_SYS_FLASH_LOCK_TOUT
3656 Timeout for Flash set sector lock bit operation (in ms)
3658 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3659 Timeout for Flash clear lock bits operation (in ms)
3661 - CONFIG_SYS_FLASH_PROTECTION
3662 If defined, hardware flash sectors protection is used
3663 instead of U-Boot software protection.
3665 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3667 Enable TFTP transfers directly to flash memory;
3668 without this option such a download has to be
3669 performed in two steps: (1) download to RAM, and (2)
3670 copy from RAM to flash.
3672 The two-step approach is usually more reliable, since
3673 you can check if the download worked before you erase
3674 the flash, but in some situations (when system RAM is
3675 too limited to allow for a temporary copy of the
3676 downloaded image) this option may be very useful.
3678 - CONFIG_SYS_FLASH_CFI:
3679 Define if the flash driver uses extra elements in the
3680 common flash structure for storing flash geometry.
3682 - CONFIG_FLASH_CFI_DRIVER
3683 This option also enables the building of the cfi_flash driver
3684 in the drivers directory
3686 - CONFIG_FLASH_CFI_MTD
3687 This option enables the building of the cfi_mtd driver
3688 in the drivers directory. The driver exports CFI flash
3691 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3692 Use buffered writes to flash.
3694 - CONFIG_FLASH_SPANSION_S29WS_N
3695 s29ws-n MirrorBit flash has non-standard addresses for buffered
3698 - CONFIG_SYS_FLASH_QUIET_TEST
3699 If this option is defined, the common CFI flash doesn't
3700 print it's warning upon not recognized FLASH banks. This
3701 is useful, if some of the configured banks are only
3702 optionally available.
3704 - CONFIG_FLASH_SHOW_PROGRESS
3705 If defined (must be an integer), print out countdown
3706 digits and dots. Recommended value: 45 (9..1) for 80
3707 column displays, 15 (3..1) for 40 column displays.
3709 - CONFIG_FLASH_VERIFY
3710 If defined, the content of the flash (destination) is compared
3711 against the source after the write operation. An error message
3712 will be printed when the contents are not identical.
3713 Please note that this option is useless in nearly all cases,
3714 since such flash programming errors usually are detected earlier
3715 while unprotecting/erasing/programming. Please only enable
3716 this option if you really know what you are doing.
3718 - CONFIG_SYS_RX_ETH_BUFFER:
3719 Defines the number of Ethernet receive buffers. On some
3720 Ethernet controllers it is recommended to set this value
3721 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3722 buffers can be full shortly after enabling the interface
3723 on high Ethernet traffic.
3724 Defaults to 4 if not defined.
3726 - CONFIG_ENV_MAX_ENTRIES
3728 Maximum number of entries in the hash table that is used
3729 internally to store the environment settings. The default
3730 setting is supposed to be generous and should work in most
3731 cases. This setting can be used to tune behaviour; see
3732 lib/hashtable.c for details.
3734 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3735 - CONFIG_ENV_FLAGS_LIST_STATIC
3736 Enable validation of the values given to environment variables when
3737 calling env set. Variables can be restricted to only decimal,
3738 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3739 the variables can also be restricted to IP address or MAC address.
3741 The format of the list is:
3742 type_attribute = [s|d|x|b|i|m]
3743 access_atribute = [a|r|o|c]
3744 attributes = type_attribute[access_atribute]
3745 entry = variable_name[:attributes]
3748 The type attributes are:
3749 s - String (default)
3752 b - Boolean ([1yYtT|0nNfF])
3756 The access attributes are:
3762 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3763 Define this to a list (string) to define the ".flags"
3764 envirnoment variable in the default or embedded environment.
3766 - CONFIG_ENV_FLAGS_LIST_STATIC
3767 Define this to a list (string) to define validation that
3768 should be done if an entry is not found in the ".flags"
3769 environment variable. To override a setting in the static
3770 list, simply add an entry for the same variable name to the
3773 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3774 If defined, don't allow the -f switch to env set override variable
3777 - CONFIG_SYS_GENERIC_BOARD
3778 This selects the architecture-generic board system instead of the
3779 architecture-specific board files. It is intended to move boards
3780 to this new framework over time. Defining this will disable the
3781 arch/foo/lib/board.c file and use common/board_f.c and
3782 common/board_r.c instead. To use this option your architecture
3783 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3784 its config.mk file). If you find problems enabling this option on
3785 your board please report the problem and send patches!
3787 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3788 This is set by OMAP boards for the max time that reset should
3789 be asserted. See doc/README.omap-reset-time for details on how
3790 the value can be calulated on a given board.
3792 The following definitions that deal with the placement and management
3793 of environment data (variable area); in general, we support the
3794 following configurations:
3796 - CONFIG_BUILD_ENVCRC:
3798 Builds up envcrc with the target environment so that external utils
3799 may easily extract it and embed it in final U-Boot images.
3801 - CONFIG_ENV_IS_IN_FLASH:
3803 Define this if the environment is in flash memory.
3805 a) The environment occupies one whole flash sector, which is
3806 "embedded" in the text segment with the U-Boot code. This
3807 happens usually with "bottom boot sector" or "top boot
3808 sector" type flash chips, which have several smaller
3809 sectors at the start or the end. For instance, such a
3810 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3811 such a case you would place the environment in one of the
3812 4 kB sectors - with U-Boot code before and after it. With
3813 "top boot sector" type flash chips, you would put the
3814 environment in one of the last sectors, leaving a gap
3815 between U-Boot and the environment.
3817 - CONFIG_ENV_OFFSET:
3819 Offset of environment data (variable area) to the
3820 beginning of flash memory; for instance, with bottom boot
3821 type flash chips the second sector can be used: the offset
3822 for this sector is given here.
3824 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3828 This is just another way to specify the start address of
3829 the flash sector containing the environment (instead of
3832 - CONFIG_ENV_SECT_SIZE:
3834 Size of the sector containing the environment.
3837 b) Sometimes flash chips have few, equal sized, BIG sectors.
3838 In such a case you don't want to spend a whole sector for
3843 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3844 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3845 of this flash sector for the environment. This saves
3846 memory for the RAM copy of the environment.
3848 It may also save flash memory if you decide to use this
3849 when your environment is "embedded" within U-Boot code,
3850 since then the remainder of the flash sector could be used
3851 for U-Boot code. It should be pointed out that this is
3852 STRONGLY DISCOURAGED from a robustness point of view:
3853 updating the environment in flash makes it always
3854 necessary to erase the WHOLE sector. If something goes
3855 wrong before the contents has been restored from a copy in
3856 RAM, your target system will be dead.
3858 - CONFIG_ENV_ADDR_REDUND
3859 CONFIG_ENV_SIZE_REDUND
3861 These settings describe a second storage area used to hold
3862 a redundant copy of the environment data, so that there is
3863 a valid backup copy in case there is a power failure during
3864 a "saveenv" operation.
3866 BE CAREFUL! Any changes to the flash layout, and some changes to the
3867 source code will make it necessary to adapt <board>/u-boot.lds*
3871 - CONFIG_ENV_IS_IN_NVRAM:
3873 Define this if you have some non-volatile memory device
3874 (NVRAM, battery buffered SRAM) which you want to use for the
3880 These two #defines are used to determine the memory area you
3881 want to use for environment. It is assumed that this memory
3882 can just be read and written to, without any special
3885 BE CAREFUL! The first access to the environment happens quite early
3886 in U-Boot initalization (when we try to get the setting of for the
3887 console baudrate). You *MUST* have mapped your NVRAM area then, or
3890 Please note that even with NVRAM we still use a copy of the
3891 environment in RAM: we could work on NVRAM directly, but we want to
3892 keep settings there always unmodified except somebody uses "saveenv"
3893 to save the current settings.
3896 - CONFIG_ENV_IS_IN_EEPROM:
3898 Use this if you have an EEPROM or similar serial access
3899 device and a driver for it.
3901 - CONFIG_ENV_OFFSET:
3904 These two #defines specify the offset and size of the
3905 environment area within the total memory of your EEPROM.
3907 - CONFIG_SYS_I2C_EEPROM_ADDR:
3908 If defined, specified the chip address of the EEPROM device.
3909 The default address is zero.
3911 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3912 If defined, the number of bits used to address bytes in a
3913 single page in the EEPROM device. A 64 byte page, for example
3914 would require six bits.
3916 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3917 If defined, the number of milliseconds to delay between
3918 page writes. The default is zero milliseconds.
3920 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3921 The length in bytes of the EEPROM memory array address. Note
3922 that this is NOT the chip address length!
3924 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3925 EEPROM chips that implement "address overflow" are ones
3926 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3927 address and the extra bits end up in the "chip address" bit
3928 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3931 Note that we consider the length of the address field to
3932 still be one byte because the extra address bits are hidden
3933 in the chip address.
3935 - CONFIG_SYS_EEPROM_SIZE:
3936 The size in bytes of the EEPROM device.
3938 - CONFIG_ENV_EEPROM_IS_ON_I2C
3939 define this, if you have I2C and SPI activated, and your
3940 EEPROM, which holds the environment, is on the I2C bus.
3942 - CONFIG_I2C_ENV_EEPROM_BUS
3943 if you have an Environment on an EEPROM reached over
3944 I2C muxes, you can define here, how to reach this
3945 EEPROM. For example:
3947 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3949 EEPROM which holds the environment, is reached over
3950 a pca9547 i2c mux with address 0x70, channel 3.
3952 - CONFIG_ENV_IS_IN_DATAFLASH:
3954 Define this if you have a DataFlash memory device which you
3955 want to use for the environment.
3957 - CONFIG_ENV_OFFSET:
3961 These three #defines specify the offset and size of the
3962 environment area within the total memory of your DataFlash placed
3963 at the specified address.
3965 - CONFIG_ENV_IS_IN_REMOTE:
3967 Define this if you have a remote memory space which you
3968 want to use for the local device's environment.
3973 These two #defines specify the address and size of the
3974 environment area within the remote memory space. The
3975 local device can get the environment from remote memory
3976 space by SRIO or PCIE links.
3978 BE CAREFUL! For some special cases, the local device can not use
3979 "saveenv" command. For example, the local device will get the
3980 environment stored in a remote NOR flash by SRIO or PCIE link,
3981 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3983 - CONFIG_ENV_IS_IN_NAND:
3985 Define this if you have a NAND device which you want to use
3986 for the environment.
3988 - CONFIG_ENV_OFFSET:
3991 These two #defines specify the offset and size of the environment
3992 area within the first NAND device. CONFIG_ENV_OFFSET must be
3993 aligned to an erase block boundary.
3995 - CONFIG_ENV_OFFSET_REDUND (optional):
3997 This setting describes a second storage area of CONFIG_ENV_SIZE
3998 size used to hold a redundant copy of the environment data, so
3999 that there is a valid backup copy in case there is a power failure
4000 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
4001 aligned to an erase block boundary.
4003 - CONFIG_ENV_RANGE (optional):
4005 Specifies the length of the region in which the environment
4006 can be written. This should be a multiple of the NAND device's
4007 block size. Specifying a range with more erase blocks than
4008 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4009 the range to be avoided.
4011 - CONFIG_ENV_OFFSET_OOB (optional):
4013 Enables support for dynamically retrieving the offset of the
4014 environment from block zero's out-of-band data. The
4015 "nand env.oob" command can be used to record this offset.
4016 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4017 using CONFIG_ENV_OFFSET_OOB.
4019 - CONFIG_NAND_ENV_DST
4021 Defines address in RAM to which the nand_spl code should copy the
4022 environment. If redundant environment is used, it will be copied to
4023 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4025 - CONFIG_ENV_IS_IN_UBI:
4027 Define this if you have an UBI volume that you want to use for the
4028 environment. This has the benefit of wear-leveling the environment
4029 accesses, which is important on NAND.
4031 - CONFIG_ENV_UBI_PART:
4033 Define this to a string that is the mtd partition containing the UBI.
4035 - CONFIG_ENV_UBI_VOLUME:
4037 Define this to the name of the volume that you want to store the
4040 - CONFIG_ENV_UBI_VOLUME_REDUND:
4042 Define this to the name of another volume to store a second copy of
4043 the environment in. This will enable redundant environments in UBI.
4044 It is assumed that both volumes are in the same MTD partition.
4046 - CONFIG_UBI_SILENCE_MSG
4047 - CONFIG_UBIFS_SILENCE_MSG
4049 You will probably want to define these to avoid a really noisy system
4050 when storing the env in UBI.
4052 - CONFIG_ENV_IS_IN_MMC:
4054 Define this if you have an MMC device which you want to use for the
4057 - CONFIG_SYS_MMC_ENV_DEV:
4059 Specifies which MMC device the environment is stored in.
4061 - CONFIG_SYS_MMC_ENV_PART (optional):
4063 Specifies which MMC partition the environment is stored in. If not
4064 set, defaults to partition 0, the user area. Common values might be
4065 1 (first MMC boot partition), 2 (second MMC boot partition).
4067 - CONFIG_ENV_OFFSET:
4070 These two #defines specify the offset and size of the environment
4071 area within the specified MMC device.
4073 If offset is positive (the usual case), it is treated as relative to
4074 the start of the MMC partition. If offset is negative, it is treated
4075 as relative to the end of the MMC partition. This can be useful if
4076 your board may be fitted with different MMC devices, which have
4077 different sizes for the MMC partitions, and you always want the
4078 environment placed at the very end of the partition, to leave the
4079 maximum possible space before it, to store other data.
4081 These two values are in units of bytes, but must be aligned to an
4082 MMC sector boundary.
4084 - CONFIG_ENV_OFFSET_REDUND (optional):
4086 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4087 hold a redundant copy of the environment data. This provides a
4088 valid backup copy in case the other copy is corrupted, e.g. due
4089 to a power failure during a "saveenv" operation.
4091 This value may also be positive or negative; this is handled in the
4092 same way as CONFIG_ENV_OFFSET.
4094 This value is also in units of bytes, but must also be aligned to
4095 an MMC sector boundary.
4097 - CONFIG_ENV_SIZE_REDUND (optional):
4099 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4100 set. If this value is set, it must be set to the same value as
4103 - CONFIG_SYS_SPI_INIT_OFFSET
4105 Defines offset to the initial SPI buffer area in DPRAM. The
4106 area is used at an early stage (ROM part) if the environment
4107 is configured to reside in the SPI EEPROM: We need a 520 byte
4108 scratch DPRAM area. It is used between the two initialization
4109 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4110 to be a good choice since it makes it far enough from the
4111 start of the data area as well as from the stack pointer.
4113 Please note that the environment is read-only until the monitor
4114 has been relocated to RAM and a RAM copy of the environment has been
4115 created; also, when using EEPROM you will have to use getenv_f()
4116 until then to read environment variables.
4118 The environment is protected by a CRC32 checksum. Before the monitor
4119 is relocated into RAM, as a result of a bad CRC you will be working
4120 with the compiled-in default environment - *silently*!!! [This is
4121 necessary, because the first environment variable we need is the
4122 "baudrate" setting for the console - if we have a bad CRC, we don't
4123 have any device yet where we could complain.]
4125 Note: once the monitor has been relocated, then it will complain if
4126 the default environment is used; a new CRC is computed as soon as you
4127 use the "saveenv" command to store a valid environment.
4129 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4130 Echo the inverted Ethernet link state to the fault LED.
4132 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4133 also needs to be defined.
4135 - CONFIG_SYS_FAULT_MII_ADDR:
4136 MII address of the PHY to check for the Ethernet link state.
4138 - CONFIG_NS16550_MIN_FUNCTIONS:
4139 Define this if you desire to only have use of the NS16550_init
4140 and NS16550_putc functions for the serial driver located at
4141 drivers/serial/ns16550.c. This option is useful for saving
4142 space for already greatly restricted images, including but not
4143 limited to NAND_SPL configurations.
4145 - CONFIG_DISPLAY_BOARDINFO
4146 Display information about the board that U-Boot is running on
4147 when U-Boot starts up. The board function checkboard() is called
4150 - CONFIG_DISPLAY_BOARDINFO_LATE
4151 Similar to the previous option, but display this information
4152 later, once stdio is running and output goes to the LCD, if
4155 Low Level (hardware related) configuration options:
4156 ---------------------------------------------------
4158 - CONFIG_SYS_CACHELINE_SIZE:
4159 Cache Line Size of the CPU.
4161 - CONFIG_SYS_DEFAULT_IMMR:
4162 Default address of the IMMR after system reset.
4164 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4165 and RPXsuper) to be able to adjust the position of
4166 the IMMR register after a reset.
4168 - CONFIG_SYS_CCSRBAR_DEFAULT:
4169 Default (power-on reset) physical address of CCSR on Freescale
4172 - CONFIG_SYS_CCSRBAR:
4173 Virtual address of CCSR. On a 32-bit build, this is typically
4174 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4176 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4177 for cross-platform code that uses that macro instead.
4179 - CONFIG_SYS_CCSRBAR_PHYS:
4180 Physical address of CCSR. CCSR can be relocated to a new
4181 physical address, if desired. In this case, this macro should
4182 be set to that address. Otherwise, it should be set to the
4183 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4184 is typically relocated on 36-bit builds. It is recommended
4185 that this macro be defined via the _HIGH and _LOW macros:
4187 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4188 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4190 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4191 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4192 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4193 used in assembly code, so it must not contain typecasts or
4194 integer size suffixes (e.g. "ULL").
4196 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4197 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4198 used in assembly code, so it must not contain typecasts or
4199 integer size suffixes (e.g. "ULL").
4201 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4202 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4203 forced to a value that ensures that CCSR is not relocated.
4205 - Floppy Disk Support:
4206 CONFIG_SYS_FDC_DRIVE_NUMBER
4208 the default drive number (default value 0)
4210 CONFIG_SYS_ISA_IO_STRIDE
4212 defines the spacing between FDC chipset registers
4215 CONFIG_SYS_ISA_IO_OFFSET
4217 defines the offset of register from address. It
4218 depends on which part of the data bus is connected to
4219 the FDC chipset. (default value 0)
4221 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4222 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4225 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4226 fdc_hw_init() is called at the beginning of the FDC
4227 setup. fdc_hw_init() must be provided by the board
4228 source code. It is used to make hardware dependant
4232 Most IDE controllers were designed to be connected with PCI
4233 interface. Only few of them were designed for AHB interface.
4234 When software is doing ATA command and data transfer to
4235 IDE devices through IDE-AHB controller, some additional
4236 registers accessing to these kind of IDE-AHB controller
4239 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4240 DO NOT CHANGE unless you know exactly what you're
4241 doing! (11-4) [MPC8xx/82xx systems only]
4243 - CONFIG_SYS_INIT_RAM_ADDR:
4245 Start address of memory area that can be used for
4246 initial data and stack; please note that this must be
4247 writable memory that is working WITHOUT special
4248 initialization, i. e. you CANNOT use normal RAM which
4249 will become available only after programming the
4250 memory controller and running certain initialization
4253 U-Boot uses the following memory types:
4254 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4255 - MPC824X: data cache
4256 - PPC4xx: data cache
4258 - CONFIG_SYS_GBL_DATA_OFFSET:
4260 Offset of the initial data structure in the memory
4261 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4262 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4263 data is located at the end of the available space
4264 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4265 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4266 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4267 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4270 On the MPC824X (or other systems that use the data
4271 cache for initial memory) the address chosen for
4272 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4273 point to an otherwise UNUSED address space between
4274 the top of RAM and the start of the PCI space.
4276 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4278 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4280 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4282 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4284 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4286 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4288 - CONFIG_SYS_OR_TIMING_SDRAM:
4291 - CONFIG_SYS_MAMR_PTA:
4292 periodic timer for refresh
4294 - CONFIG_SYS_DER: Debug Event Register (37-47)
4296 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4297 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4298 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4299 CONFIG_SYS_BR1_PRELIM:
4300 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4302 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4303 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4304 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4305 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4307 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4308 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4309 Machine Mode Register and Memory Periodic Timer
4310 Prescaler definitions (SDRAM timing)
4312 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4313 enable I2C microcode relocation patch (MPC8xx);
4314 define relocation offset in DPRAM [DSP2]
4316 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4317 enable SMC microcode relocation patch (MPC8xx);
4318 define relocation offset in DPRAM [SMC1]
4320 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4321 enable SPI microcode relocation patch (MPC8xx);
4322 define relocation offset in DPRAM [SCC4]
4324 - CONFIG_SYS_USE_OSCCLK:
4325 Use OSCM clock mode on MBX8xx board. Be careful,
4326 wrong setting might damage your board. Read
4327 doc/README.MBX before setting this variable!
4329 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4330 Offset of the bootmode word in DPRAM used by post
4331 (Power On Self Tests). This definition overrides
4332 #define'd default value in commproc.h resp.
4335 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4336 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4337 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4338 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4339 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4340 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4341 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4342 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4343 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4345 - CONFIG_PCI_DISABLE_PCIE:
4346 Disable PCI-Express on systems where it is supported but not
4349 - CONFIG_PCI_ENUM_ONLY
4350 Only scan through and get the devices on the busses.
4351 Don't do any setup work, presumably because someone or
4352 something has already done it, and we don't need to do it
4353 a second time. Useful for platforms that are pre-booted
4354 by coreboot or similar.
4356 - CONFIG_PCI_INDIRECT_BRIDGE:
4357 Enable support for indirect PCI bridges.
4360 Chip has SRIO or not
4363 Board has SRIO 1 port available
4366 Board has SRIO 2 port available
4368 - CONFIG_SRIO_PCIE_BOOT_MASTER
4369 Board can support master function for Boot from SRIO and PCIE
4371 - CONFIG_SYS_SRIOn_MEM_VIRT:
4372 Virtual Address of SRIO port 'n' memory region
4374 - CONFIG_SYS_SRIOn_MEM_PHYS:
4375 Physical Address of SRIO port 'n' memory region
4377 - CONFIG_SYS_SRIOn_MEM_SIZE:
4378 Size of SRIO port 'n' memory region
4380 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4381 Defined to tell the NAND controller that the NAND chip is using
4383 Not all NAND drivers use this symbol.
4384 Example of drivers that use it:
4385 - drivers/mtd/nand/ndfc.c
4386 - drivers/mtd/nand/mxc_nand.c
4388 - CONFIG_SYS_NDFC_EBC0_CFG
4389 Sets the EBC0_CFG register for the NDFC. If not defined
4390 a default value will be used.
4393 Get DDR timing information from an I2C EEPROM. Common
4394 with pluggable memory modules such as SODIMMs
4397 I2C address of the SPD EEPROM
4399 - CONFIG_SYS_SPD_BUS_NUM
4400 If SPD EEPROM is on an I2C bus other than the first
4401 one, specify here. Note that the value must resolve
4402 to something your driver can deal with.
4404 - CONFIG_SYS_DDR_RAW_TIMING
4405 Get DDR timing information from other than SPD. Common with
4406 soldered DDR chips onboard without SPD. DDR raw timing
4407 parameters are extracted from datasheet and hard-coded into
4408 header files or board specific files.
4410 - CONFIG_FSL_DDR_INTERACTIVE
4411 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4413 - CONFIG_SYS_83XX_DDR_USES_CS0
4414 Only for 83xx systems. If specified, then DDR should
4415 be configured using CS0 and CS1 instead of CS2 and CS3.
4417 - CONFIG_ETHER_ON_FEC[12]
4418 Define to enable FEC[12] on a 8xx series processor.
4420 - CONFIG_FEC[12]_PHY
4421 Define to the hardcoded PHY address which corresponds
4422 to the given FEC; i. e.
4423 #define CONFIG_FEC1_PHY 4
4424 means that the PHY with address 4 is connected to FEC1
4426 When set to -1, means to probe for first available.
4428 - CONFIG_FEC[12]_PHY_NORXERR
4429 The PHY does not have a RXERR line (RMII only).
4430 (so program the FEC to ignore it).
4433 Enable RMII mode for all FECs.
4434 Note that this is a global option, we can't
4435 have one FEC in standard MII mode and another in RMII mode.
4437 - CONFIG_CRC32_VERIFY
4438 Add a verify option to the crc32 command.
4441 => crc32 -v <address> <count> <crc32>
4443 Where address/count indicate a memory area
4444 and crc32 is the correct crc32 which the
4448 Add the "loopw" memory command. This only takes effect if
4449 the memory commands are activated globally (CONFIG_CMD_MEM).
4452 Add the "mdc" and "mwc" memory commands. These are cyclic
4457 This command will print 4 bytes (10,11,12,13) each 500 ms.
4459 => mwc.l 100 12345678 10
4460 This command will write 12345678 to address 100 all 10 ms.
4462 This only takes effect if the memory commands are activated
4463 globally (CONFIG_CMD_MEM).
4465 - CONFIG_SKIP_LOWLEVEL_INIT
4466 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4467 low level initializations (like setting up the memory
4468 controller) are omitted and/or U-Boot does not
4469 relocate itself into RAM.
4471 Normally this variable MUST NOT be defined. The only
4472 exception is when U-Boot is loaded (to RAM) by some
4473 other boot loader or by a debugger which performs
4474 these initializations itself.
4477 Modifies the behaviour of start.S when compiling a loader
4478 that is executed before the actual U-Boot. E.g. when
4479 compiling a NAND SPL.
4482 Modifies the behaviour of start.S when compiling a loader
4483 that is executed after the SPL and before the actual U-Boot.
4484 It is loaded by the SPL.
4486 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4487 Only for 85xx systems. If this variable is specified, the section
4488 .resetvec is not kept and the section .bootpg is placed in the
4489 previous 4k of the .text section.
4491 - CONFIG_ARCH_MAP_SYSMEM
4492 Generally U-Boot (and in particular the md command) uses
4493 effective address. It is therefore not necessary to regard
4494 U-Boot address as virtual addresses that need to be translated
4495 to physical addresses. However, sandbox requires this, since
4496 it maintains its own little RAM buffer which contains all
4497 addressable memory. This option causes some memory accesses
4498 to be mapped through map_sysmem() / unmap_sysmem().
4500 - CONFIG_USE_ARCH_MEMCPY
4501 CONFIG_USE_ARCH_MEMSET
4502 If these options are used a optimized version of memcpy/memset will
4503 be used if available. These functions may be faster under some
4504 conditions but may increase the binary size.
4506 - CONFIG_X86_RESET_VECTOR
4507 If defined, the x86 reset vector code is included. This is not
4508 needed when U-Boot is running from Coreboot.
4511 Defines the MPU clock speed (in MHz).
4513 NOTE : currently only supported on AM335x platforms.
4515 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4516 Enables the RTC32K OSC on AM33xx based plattforms
4518 Freescale QE/FMAN Firmware Support:
4519 -----------------------------------
4521 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4522 loading of "firmware", which is encoded in the QE firmware binary format.
4523 This firmware often needs to be loaded during U-Boot booting, so macros
4524 are used to identify the storage device (NOR flash, SPI, etc) and the address
4527 - CONFIG_SYS_FMAN_FW_ADDR
4528 The address in the storage device where the FMAN microcode is located. The
4529 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4532 - CONFIG_SYS_QE_FW_ADDR
4533 The address in the storage device where the QE microcode is located. The
4534 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4537 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4538 The maximum possible size of the firmware. The firmware binary format
4539 has a field that specifies the actual size of the firmware, but it
4540 might not be possible to read any part of the firmware unless some
4541 local storage is allocated to hold the entire firmware first.
4543 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4544 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4545 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4546 virtual address in NOR flash.
4548 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4549 Specifies that QE/FMAN firmware is located in NAND flash.
4550 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4552 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4553 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4554 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4556 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4557 Specifies that QE/FMAN firmware is located on the primary SPI
4558 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4560 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4561 Specifies that QE/FMAN firmware is located in the remote (master)
4562 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4563 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4564 window->master inbound window->master LAW->the ucode address in
4565 master's memory space.
4567 Building the Software:
4568 ======================
4570 Building U-Boot has been tested in several native build environments
4571 and in many different cross environments. Of course we cannot support
4572 all possibly existing versions of cross development tools in all
4573 (potentially obsolete) versions. In case of tool chain problems we
4574 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4575 which is extensively used to build and test U-Boot.
4577 If you are not using a native environment, it is assumed that you
4578 have GNU cross compiling tools available in your path. In this case,
4579 you must set the environment variable CROSS_COMPILE in your shell.
4580 Note that no changes to the Makefile or any other source files are
4581 necessary. For example using the ELDK on a 4xx CPU, please enter:
4583 $ CROSS_COMPILE=ppc_4xx-
4584 $ export CROSS_COMPILE
4586 Note: If you wish to generate Windows versions of the utilities in
4587 the tools directory you can use the MinGW toolchain
4588 (http://www.mingw.org). Set your HOST tools to the MinGW
4589 toolchain and execute 'make tools'. For example:
4591 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4593 Binaries such as tools/mkimage.exe will be created which can
4594 be executed on computers running Windows.
4596 U-Boot is intended to be simple to build. After installing the
4597 sources you must configure U-Boot for one specific board type. This
4602 where "NAME_config" is the name of one of the existing configu-
4603 rations; see boards.cfg for supported names.
4605 Note: for some board special configuration names may exist; check if
4606 additional information is available from the board vendor; for
4607 instance, the TQM823L systems are available without (standard)
4608 or with LCD support. You can select such additional "features"
4609 when choosing the configuration, i. e.
4612 - will configure for a plain TQM823L, i. e. no LCD support
4614 make TQM823L_LCD_config
4615 - will configure for a TQM823L with U-Boot console on LCD
4620 Finally, type "make all", and you should get some working U-Boot
4621 images ready for download to / installation on your system:
4623 - "u-boot.bin" is a raw binary image
4624 - "u-boot" is an image in ELF binary format
4625 - "u-boot.srec" is in Motorola S-Record format
4627 By default the build is performed locally and the objects are saved
4628 in the source directory. One of the two methods can be used to change
4629 this behavior and build U-Boot to some external directory:
4631 1. Add O= to the make command line invocations:
4633 make O=/tmp/build distclean
4634 make O=/tmp/build NAME_config
4635 make O=/tmp/build all
4637 2. Set environment variable BUILD_DIR to point to the desired location:
4639 export BUILD_DIR=/tmp/build
4644 Note that the command line "O=" setting overrides the BUILD_DIR environment
4648 Please be aware that the Makefiles assume you are using GNU make, so
4649 for instance on NetBSD you might need to use "gmake" instead of
4653 If the system board that you have is not listed, then you will need
4654 to port U-Boot to your hardware platform. To do this, follow these
4657 1. Add a new configuration option for your board to the toplevel
4658 "boards.cfg" file, using the existing entries as examples.
4659 Follow the instructions there to keep the boards in order.
4660 2. Create a new directory to hold your board specific code. Add any
4661 files you need. In your board directory, you will need at least
4662 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4663 3. Create a new configuration file "include/configs/<board>.h" for
4665 3. If you're porting U-Boot to a new CPU, then also create a new
4666 directory to hold your CPU specific code. Add any files you need.
4667 4. Run "make <board>_config" with your new name.
4668 5. Type "make", and you should get a working "u-boot.srec" file
4669 to be installed on your target system.
4670 6. Debug and solve any problems that might arise.
4671 [Of course, this last step is much harder than it sounds.]
4674 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4675 ==============================================================
4677 If you have modified U-Boot sources (for instance added a new board
4678 or support for new devices, a new CPU, etc.) you are expected to
4679 provide feedback to the other developers. The feedback normally takes
4680 the form of a "patch", i. e. a context diff against a certain (latest
4681 official or latest in the git repository) version of U-Boot sources.
4683 But before you submit such a patch, please verify that your modifi-
4684 cation did not break existing code. At least make sure that *ALL* of
4685 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4686 just run the "MAKEALL" script, which will configure and build U-Boot
4687 for ALL supported system. Be warned, this will take a while. You can
4688 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4689 environment variable to the script, i. e. to use the ELDK cross tools
4692 CROSS_COMPILE=ppc_8xx- MAKEALL
4694 or to build on a native PowerPC system you can type
4696 CROSS_COMPILE=' ' MAKEALL
4698 When using the MAKEALL script, the default behaviour is to build
4699 U-Boot in the source directory. This location can be changed by
4700 setting the BUILD_DIR environment variable. Also, for each target
4701 built, the MAKEALL script saves two log files (<target>.ERR and
4702 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4703 location can be changed by setting the MAKEALL_LOGDIR environment
4704 variable. For example:
4706 export BUILD_DIR=/tmp/build
4707 export MAKEALL_LOGDIR=/tmp/log
4708 CROSS_COMPILE=ppc_8xx- MAKEALL
4710 With the above settings build objects are saved in the /tmp/build,
4711 log files are saved in the /tmp/log and the source tree remains clean
4712 during the whole build process.
4715 See also "U-Boot Porting Guide" below.
4718 Monitor Commands - Overview:
4719 ============================
4721 go - start application at address 'addr'
4722 run - run commands in an environment variable
4723 bootm - boot application image from memory
4724 bootp - boot image via network using BootP/TFTP protocol
4725 bootz - boot zImage from memory
4726 tftpboot- boot image via network using TFTP protocol
4727 and env variables "ipaddr" and "serverip"
4728 (and eventually "gatewayip")
4729 tftpput - upload a file via network using TFTP protocol
4730 rarpboot- boot image via network using RARP/TFTP protocol
4731 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4732 loads - load S-Record file over serial line
4733 loadb - load binary file over serial line (kermit mode)
4735 mm - memory modify (auto-incrementing)
4736 nm - memory modify (constant address)
4737 mw - memory write (fill)
4739 cmp - memory compare
4740 crc32 - checksum calculation
4741 i2c - I2C sub-system
4742 sspi - SPI utility commands
4743 base - print or set address offset
4744 printenv- print environment variables
4745 setenv - set environment variables
4746 saveenv - save environment variables to persistent storage
4747 protect - enable or disable FLASH write protection
4748 erase - erase FLASH memory
4749 flinfo - print FLASH memory information
4750 nand - NAND memory operations (see doc/README.nand)
4751 bdinfo - print Board Info structure
4752 iminfo - print header information for application image
4753 coninfo - print console devices and informations
4754 ide - IDE sub-system
4755 loop - infinite loop on address range
4756 loopw - infinite write loop on address range
4757 mtest - simple RAM test
4758 icache - enable or disable instruction cache
4759 dcache - enable or disable data cache
4760 reset - Perform RESET of the CPU
4761 echo - echo args to console
4762 version - print monitor version
4763 help - print online help
4764 ? - alias for 'help'
4767 Monitor Commands - Detailed Description:
4768 ========================================
4772 For now: just type "help <command>".
4775 Environment Variables:
4776 ======================
4778 U-Boot supports user configuration using Environment Variables which
4779 can be made persistent by saving to Flash memory.
4781 Environment Variables are set using "setenv", printed using
4782 "printenv", and saved to Flash using "saveenv". Using "setenv"
4783 without a value can be used to delete a variable from the
4784 environment. As long as you don't save the environment you are
4785 working with an in-memory copy. In case the Flash area containing the
4786 environment is erased by accident, a default environment is provided.
4788 Some configuration options can be set using Environment Variables.
4790 List of environment variables (most likely not complete):
4792 baudrate - see CONFIG_BAUDRATE
4794 bootdelay - see CONFIG_BOOTDELAY
4796 bootcmd - see CONFIG_BOOTCOMMAND
4798 bootargs - Boot arguments when booting an RTOS image
4800 bootfile - Name of the image to load with TFTP
4802 bootm_low - Memory range available for image processing in the bootm
4803 command can be restricted. This variable is given as
4804 a hexadecimal number and defines lowest address allowed
4805 for use by the bootm command. See also "bootm_size"
4806 environment variable. Address defined by "bootm_low" is
4807 also the base of the initial memory mapping for the Linux
4808 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4811 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4812 This variable is given as a hexadecimal number and it
4813 defines the size of the memory region starting at base
4814 address bootm_low that is accessible by the Linux kernel
4815 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4816 as the default value if it is defined, and bootm_size is
4819 bootm_size - Memory range available for image processing in the bootm
4820 command can be restricted. This variable is given as
4821 a hexadecimal number and defines the size of the region
4822 allowed for use by the bootm command. See also "bootm_low"
4823 environment variable.
4825 updatefile - Location of the software update file on a TFTP server, used
4826 by the automatic software update feature. Please refer to
4827 documentation in doc/README.update for more details.
4829 autoload - if set to "no" (any string beginning with 'n'),
4830 "bootp" will just load perform a lookup of the
4831 configuration from the BOOTP server, but not try to
4832 load any image using TFTP
4834 autostart - if set to "yes", an image loaded using the "bootp",
4835 "rarpboot", "tftpboot" or "diskboot" commands will
4836 be automatically started (by internally calling
4839 If set to "no", a standalone image passed to the
4840 "bootm" command will be copied to the load address
4841 (and eventually uncompressed), but NOT be started.
4842 This can be used to load and uncompress arbitrary
4845 fdt_high - if set this restricts the maximum address that the
4846 flattened device tree will be copied into upon boot.
4847 For example, if you have a system with 1 GB memory
4848 at physical address 0x10000000, while Linux kernel
4849 only recognizes the first 704 MB as low memory, you
4850 may need to set fdt_high as 0x3C000000 to have the
4851 device tree blob be copied to the maximum address
4852 of the 704 MB low memory, so that Linux kernel can
4853 access it during the boot procedure.
4855 If this is set to the special value 0xFFFFFFFF then
4856 the fdt will not be copied at all on boot. For this
4857 to work it must reside in writable memory, have
4858 sufficient padding on the end of it for u-boot to
4859 add the information it needs into it, and the memory
4860 must be accessible by the kernel.
4862 fdtcontroladdr- if set this is the address of the control flattened
4863 device tree used by U-Boot when CONFIG_OF_CONTROL is
4866 i2cfast - (PPC405GP|PPC405EP only)
4867 if set to 'y' configures Linux I2C driver for fast
4868 mode (400kHZ). This environment variable is used in
4869 initialization code. So, for changes to be effective
4870 it must be saved and board must be reset.
4872 initrd_high - restrict positioning of initrd images:
4873 If this variable is not set, initrd images will be
4874 copied to the highest possible address in RAM; this
4875 is usually what you want since it allows for
4876 maximum initrd size. If for some reason you want to
4877 make sure that the initrd image is loaded below the
4878 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4879 variable to a value of "no" or "off" or "0".
4880 Alternatively, you can set it to a maximum upper
4881 address to use (U-Boot will still check that it
4882 does not overwrite the U-Boot stack and data).
4884 For instance, when you have a system with 16 MB
4885 RAM, and want to reserve 4 MB from use by Linux,
4886 you can do this by adding "mem=12M" to the value of
4887 the "bootargs" variable. However, now you must make
4888 sure that the initrd image is placed in the first
4889 12 MB as well - this can be done with
4891 setenv initrd_high 00c00000
4893 If you set initrd_high to 0xFFFFFFFF, this is an
4894 indication to U-Boot that all addresses are legal
4895 for the Linux kernel, including addresses in flash
4896 memory. In this case U-Boot will NOT COPY the
4897 ramdisk at all. This may be useful to reduce the
4898 boot time on your system, but requires that this
4899 feature is supported by your Linux kernel.
4901 ipaddr - IP address; needed for tftpboot command
4903 loadaddr - Default load address for commands like "bootp",
4904 "rarpboot", "tftpboot", "loadb" or "diskboot"
4906 loads_echo - see CONFIG_LOADS_ECHO
4908 serverip - TFTP server IP address; needed for tftpboot command
4910 bootretry - see CONFIG_BOOT_RETRY_TIME
4912 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4914 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4916 ethprime - controls which interface is used first.
4918 ethact - controls which interface is currently active.
4919 For example you can do the following
4921 => setenv ethact FEC
4922 => ping 192.168.0.1 # traffic sent on FEC
4923 => setenv ethact SCC
4924 => ping 10.0.0.1 # traffic sent on SCC
4926 ethrotate - When set to "no" U-Boot does not go through all
4927 available network interfaces.
4928 It just stays at the currently selected interface.
4930 netretry - When set to "no" each network operation will
4931 either succeed or fail without retrying.
4932 When set to "once" the network operation will
4933 fail when all the available network interfaces
4934 are tried once without success.
4935 Useful on scripts which control the retry operation
4938 npe_ucode - set load address for the NPE microcode
4940 silent_linux - If set then linux will be told to boot silently, by
4941 changing the console to be empty. If "yes" it will be
4942 made silent. If "no" it will not be made silent. If
4943 unset, then it will be made silent if the U-Boot console
4946 tftpsrcport - If this is set, the value is used for TFTP's
4949 tftpdstport - If this is set, the value is used for TFTP's UDP
4950 destination port instead of the Well Know Port 69.
4952 tftpblocksize - Block size to use for TFTP transfers; if not set,
4953 we use the TFTP server's default block size
4955 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4956 seconds, minimum value is 1000 = 1 second). Defines
4957 when a packet is considered to be lost so it has to
4958 be retransmitted. The default is 5000 = 5 seconds.
4959 Lowering this value may make downloads succeed
4960 faster in networks with high packet loss rates or
4961 with unreliable TFTP servers.
4963 vlan - When set to a value < 4095 the traffic over
4964 Ethernet is encapsulated/received over 802.1q
4967 The following image location variables contain the location of images
4968 used in booting. The "Image" column gives the role of the image and is
4969 not an environment variable name. The other columns are environment
4970 variable names. "File Name" gives the name of the file on a TFTP
4971 server, "RAM Address" gives the location in RAM the image will be
4972 loaded to, and "Flash Location" gives the image's address in NOR
4973 flash or offset in NAND flash.
4975 *Note* - these variables don't have to be defined for all boards, some
4976 boards currenlty use other variables for these purposes, and some
4977 boards use these variables for other purposes.
4979 Image File Name RAM Address Flash Location
4980 ----- --------- ----------- --------------
4981 u-boot u-boot u-boot_addr_r u-boot_addr
4982 Linux kernel bootfile kernel_addr_r kernel_addr
4983 device tree blob fdtfile fdt_addr_r fdt_addr
4984 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4986 The following environment variables may be used and automatically
4987 updated by the network boot commands ("bootp" and "rarpboot"),
4988 depending the information provided by your boot server:
4990 bootfile - see above
4991 dnsip - IP address of your Domain Name Server
4992 dnsip2 - IP address of your secondary Domain Name Server
4993 gatewayip - IP address of the Gateway (Router) to use
4994 hostname - Target hostname
4996 netmask - Subnet Mask
4997 rootpath - Pathname of the root filesystem on the NFS server
4998 serverip - see above
5001 There are two special Environment Variables:
5003 serial# - contains hardware identification information such
5004 as type string and/or serial number
5005 ethaddr - Ethernet address
5007 These variables can be set only once (usually during manufacturing of
5008 the board). U-Boot refuses to delete or overwrite these variables
5009 once they have been set once.
5012 Further special Environment Variables:
5014 ver - Contains the U-Boot version string as printed
5015 with the "version" command. This variable is
5016 readonly (see CONFIG_VERSION_VARIABLE).
5019 Please note that changes to some configuration parameters may take
5020 only effect after the next boot (yes, that's just like Windoze :-).
5023 Callback functions for environment variables:
5024 ---------------------------------------------
5026 For some environment variables, the behavior of u-boot needs to change
5027 when their values are changed. This functionailty allows functions to
5028 be associated with arbitrary variables. On creation, overwrite, or
5029 deletion, the callback will provide the opportunity for some side
5030 effect to happen or for the change to be rejected.
5032 The callbacks are named and associated with a function using the
5033 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5035 These callbacks are associated with variables in one of two ways. The
5036 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5037 in the board configuration to a string that defines a list of
5038 associations. The list must be in the following format:
5040 entry = variable_name[:callback_name]
5043 If the callback name is not specified, then the callback is deleted.
5044 Spaces are also allowed anywhere in the list.
5046 Callbacks can also be associated by defining the ".callbacks" variable
5047 with the same list format above. Any association in ".callbacks" will
5048 override any association in the static list. You can define
5049 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5050 ".callbacks" envirnoment variable in the default or embedded environment.
5053 Command Line Parsing:
5054 =====================
5056 There are two different command line parsers available with U-Boot:
5057 the old "simple" one, and the much more powerful "hush" shell:
5059 Old, simple command line parser:
5060 --------------------------------
5062 - supports environment variables (through setenv / saveenv commands)
5063 - several commands on one line, separated by ';'
5064 - variable substitution using "... ${name} ..." syntax
5065 - special characters ('$', ';') can be escaped by prefixing with '\',
5067 setenv bootcmd bootm \${address}
5068 - You can also escape text by enclosing in single apostrophes, for example:
5069 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5074 - similar to Bourne shell, with control structures like
5075 if...then...else...fi, for...do...done; while...do...done,
5076 until...do...done, ...
5077 - supports environment ("global") variables (through setenv / saveenv
5078 commands) and local shell variables (through standard shell syntax
5079 "name=value"); only environment variables can be used with "run"
5085 (1) If a command line (or an environment variable executed by a "run"
5086 command) contains several commands separated by semicolon, and
5087 one of these commands fails, then the remaining commands will be
5090 (2) If you execute several variables with one call to run (i. e.
5091 calling run with a list of variables as arguments), any failing
5092 command will cause "run" to terminate, i. e. the remaining
5093 variables are not executed.
5095 Note for Redundant Ethernet Interfaces:
5096 =======================================
5098 Some boards come with redundant Ethernet interfaces; U-Boot supports
5099 such configurations and is capable of automatic selection of a
5100 "working" interface when needed. MAC assignment works as follows:
5102 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5103 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5104 "eth1addr" (=>eth1), "eth2addr", ...
5106 If the network interface stores some valid MAC address (for instance
5107 in SROM), this is used as default address if there is NO correspon-
5108 ding setting in the environment; if the corresponding environment
5109 variable is set, this overrides the settings in the card; that means:
5111 o If the SROM has a valid MAC address, and there is no address in the
5112 environment, the SROM's address is used.
5114 o If there is no valid address in the SROM, and a definition in the
5115 environment exists, then the value from the environment variable is
5118 o If both the SROM and the environment contain a MAC address, and
5119 both addresses are the same, this MAC address is used.
5121 o If both the SROM and the environment contain a MAC address, and the
5122 addresses differ, the value from the environment is used and a
5125 o If neither SROM nor the environment contain a MAC address, an error
5128 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5129 will be programmed into hardware as part of the initialization process. This
5130 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5131 The naming convention is as follows:
5132 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5137 U-Boot is capable of booting (and performing other auxiliary operations on)
5138 images in two formats:
5140 New uImage format (FIT)
5141 -----------------------
5143 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5144 to Flattened Device Tree). It allows the use of images with multiple
5145 components (several kernels, ramdisks, etc.), with contents protected by
5146 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5152 Old image format is based on binary files which can be basically anything,
5153 preceded by a special header; see the definitions in include/image.h for
5154 details; basically, the header defines the following image properties:
5156 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5157 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5158 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5159 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5161 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5162 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5163 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5164 * Compression Type (uncompressed, gzip, bzip2)
5170 The header is marked by a special Magic Number, and both the header
5171 and the data portions of the image are secured against corruption by
5178 Although U-Boot should support any OS or standalone application
5179 easily, the main focus has always been on Linux during the design of
5182 U-Boot includes many features that so far have been part of some
5183 special "boot loader" code within the Linux kernel. Also, any
5184 "initrd" images to be used are no longer part of one big Linux image;
5185 instead, kernel and "initrd" are separate images. This implementation
5186 serves several purposes:
5188 - the same features can be used for other OS or standalone
5189 applications (for instance: using compressed images to reduce the
5190 Flash memory footprint)
5192 - it becomes much easier to port new Linux kernel versions because
5193 lots of low-level, hardware dependent stuff are done by U-Boot
5195 - the same Linux kernel image can now be used with different "initrd"
5196 images; of course this also means that different kernel images can
5197 be run with the same "initrd". This makes testing easier (you don't
5198 have to build a new "zImage.initrd" Linux image when you just
5199 change a file in your "initrd"). Also, a field-upgrade of the
5200 software is easier now.
5206 Porting Linux to U-Boot based systems:
5207 ---------------------------------------
5209 U-Boot cannot save you from doing all the necessary modifications to
5210 configure the Linux device drivers for use with your target hardware
5211 (no, we don't intend to provide a full virtual machine interface to
5214 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5216 Just make sure your machine specific header file (for instance
5217 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5218 Information structure as we define in include/asm-<arch>/u-boot.h,
5219 and make sure that your definition of IMAP_ADDR uses the same value
5220 as your U-Boot configuration in CONFIG_SYS_IMMR.
5223 Configuring the Linux kernel:
5224 -----------------------------
5226 No specific requirements for U-Boot. Make sure you have some root
5227 device (initial ramdisk, NFS) for your target system.
5230 Building a Linux Image:
5231 -----------------------
5233 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5234 not used. If you use recent kernel source, a new build target
5235 "uImage" will exist which automatically builds an image usable by
5236 U-Boot. Most older kernels also have support for a "pImage" target,
5237 which was introduced for our predecessor project PPCBoot and uses a
5238 100% compatible format.
5247 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5248 encapsulate a compressed Linux kernel image with header information,
5249 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5251 * build a standard "vmlinux" kernel image (in ELF binary format):
5253 * convert the kernel into a raw binary image:
5255 ${CROSS_COMPILE}-objcopy -O binary \
5256 -R .note -R .comment \
5257 -S vmlinux linux.bin
5259 * compress the binary image:
5263 * package compressed binary image for U-Boot:
5265 mkimage -A ppc -O linux -T kernel -C gzip \
5266 -a 0 -e 0 -n "Linux Kernel Image" \
5267 -d linux.bin.gz uImage
5270 The "mkimage" tool can also be used to create ramdisk images for use
5271 with U-Boot, either separated from the Linux kernel image, or
5272 combined into one file. "mkimage" encapsulates the images with a 64
5273 byte header containing information about target architecture,
5274 operating system, image type, compression method, entry points, time
5275 stamp, CRC32 checksums, etc.
5277 "mkimage" can be called in two ways: to verify existing images and
5278 print the header information, or to build new images.
5280 In the first form (with "-l" option) mkimage lists the information
5281 contained in the header of an existing U-Boot image; this includes
5282 checksum verification:
5284 tools/mkimage -l image
5285 -l ==> list image header information
5287 The second form (with "-d" option) is used to build a U-Boot image
5288 from a "data file" which is used as image payload:
5290 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5291 -n name -d data_file image
5292 -A ==> set architecture to 'arch'
5293 -O ==> set operating system to 'os'
5294 -T ==> set image type to 'type'
5295 -C ==> set compression type 'comp'
5296 -a ==> set load address to 'addr' (hex)
5297 -e ==> set entry point to 'ep' (hex)
5298 -n ==> set image name to 'name'
5299 -d ==> use image data from 'datafile'
5301 Right now, all Linux kernels for PowerPC systems use the same load
5302 address (0x00000000), but the entry point address depends on the
5305 - 2.2.x kernels have the entry point at 0x0000000C,
5306 - 2.3.x and later kernels have the entry point at 0x00000000.
5308 So a typical call to build a U-Boot image would read:
5310 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5311 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5312 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5313 > examples/uImage.TQM850L
5314 Image Name: 2.4.4 kernel for TQM850L
5315 Created: Wed Jul 19 02:34:59 2000
5316 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5317 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5318 Load Address: 0x00000000
5319 Entry Point: 0x00000000
5321 To verify the contents of the image (or check for corruption):
5323 -> tools/mkimage -l examples/uImage.TQM850L
5324 Image Name: 2.4.4 kernel for TQM850L
5325 Created: Wed Jul 19 02:34:59 2000
5326 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5327 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5328 Load Address: 0x00000000
5329 Entry Point: 0x00000000
5331 NOTE: for embedded systems where boot time is critical you can trade
5332 speed for memory and install an UNCOMPRESSED image instead: this
5333 needs more space in Flash, but boots much faster since it does not
5334 need to be uncompressed:
5336 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5337 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5338 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5339 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5340 > examples/uImage.TQM850L-uncompressed
5341 Image Name: 2.4.4 kernel for TQM850L
5342 Created: Wed Jul 19 02:34:59 2000
5343 Image Type: PowerPC Linux Kernel Image (uncompressed)
5344 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5345 Load Address: 0x00000000
5346 Entry Point: 0x00000000
5349 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5350 when your kernel is intended to use an initial ramdisk:
5352 -> tools/mkimage -n 'Simple Ramdisk Image' \
5353 > -A ppc -O linux -T ramdisk -C gzip \
5354 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5355 Image Name: Simple Ramdisk Image
5356 Created: Wed Jan 12 14:01:50 2000
5357 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5358 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5359 Load Address: 0x00000000
5360 Entry Point: 0x00000000
5362 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5363 option performs the converse operation of the mkimage's second form (the "-d"
5364 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5367 tools/dumpimage -i image -p position data_file
5368 -i ==> extract from the 'image' a specific 'data_file', \
5369 indexed by 'position'
5372 Installing a Linux Image:
5373 -------------------------
5375 To downloading a U-Boot image over the serial (console) interface,
5376 you must convert the image to S-Record format:
5378 objcopy -I binary -O srec examples/image examples/image.srec
5380 The 'objcopy' does not understand the information in the U-Boot
5381 image header, so the resulting S-Record file will be relative to
5382 address 0x00000000. To load it to a given address, you need to
5383 specify the target address as 'offset' parameter with the 'loads'
5386 Example: install the image to address 0x40100000 (which on the
5387 TQM8xxL is in the first Flash bank):
5389 => erase 40100000 401FFFFF
5395 ## Ready for S-Record download ...
5396 ~>examples/image.srec
5397 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5399 15989 15990 15991 15992
5400 [file transfer complete]
5402 ## Start Addr = 0x00000000
5405 You can check the success of the download using the 'iminfo' command;
5406 this includes a checksum verification so you can be sure no data
5407 corruption happened:
5411 ## Checking Image at 40100000 ...
5412 Image Name: 2.2.13 for initrd on TQM850L
5413 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5414 Data Size: 335725 Bytes = 327 kB = 0 MB
5415 Load Address: 00000000
5416 Entry Point: 0000000c
5417 Verifying Checksum ... OK
5423 The "bootm" command is used to boot an application that is stored in
5424 memory (RAM or Flash). In case of a Linux kernel image, the contents
5425 of the "bootargs" environment variable is passed to the kernel as
5426 parameters. You can check and modify this variable using the
5427 "printenv" and "setenv" commands:
5430 => printenv bootargs
5431 bootargs=root=/dev/ram
5433 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5435 => printenv bootargs
5436 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5439 ## Booting Linux kernel at 40020000 ...
5440 Image Name: 2.2.13 for NFS on TQM850L
5441 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5442 Data Size: 381681 Bytes = 372 kB = 0 MB
5443 Load Address: 00000000
5444 Entry Point: 0000000c
5445 Verifying Checksum ... OK
5446 Uncompressing Kernel Image ... OK
5447 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
5448 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5449 time_init: decrementer frequency = 187500000/60
5450 Calibrating delay loop... 49.77 BogoMIPS
5451 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5454 If you want to boot a Linux kernel with initial RAM disk, you pass
5455 the memory addresses of both the kernel and the initrd image (PPBCOOT
5456 format!) to the "bootm" command:
5458 => imi 40100000 40200000
5460 ## Checking Image at 40100000 ...
5461 Image Name: 2.2.13 for initrd on TQM850L
5462 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5463 Data Size: 335725 Bytes = 327 kB = 0 MB
5464 Load Address: 00000000
5465 Entry Point: 0000000c
5466 Verifying Checksum ... OK
5468 ## Checking Image at 40200000 ...
5469 Image Name: Simple Ramdisk Image
5470 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5471 Data Size: 566530 Bytes = 553 kB = 0 MB
5472 Load Address: 00000000
5473 Entry Point: 00000000
5474 Verifying Checksum ... OK
5476 => bootm 40100000 40200000
5477 ## Booting Linux kernel at 40100000 ...
5478 Image Name: 2.2.13 for initrd on TQM850L
5479 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5480 Data Size: 335725 Bytes = 327 kB = 0 MB
5481 Load Address: 00000000
5482 Entry Point: 0000000c
5483 Verifying Checksum ... OK
5484 Uncompressing Kernel Image ... OK
5485 ## Loading RAMDisk Image at 40200000 ...
5486 Image Name: Simple Ramdisk Image
5487 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5488 Data Size: 566530 Bytes = 553 kB = 0 MB
5489 Load Address: 00000000
5490 Entry Point: 00000000
5491 Verifying Checksum ... OK
5492 Loading Ramdisk ... OK
5493 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
5494 Boot arguments: root=/dev/ram
5495 time_init: decrementer frequency = 187500000/60
5496 Calibrating delay loop... 49.77 BogoMIPS
5498 RAMDISK: Compressed image found at block 0
5499 VFS: Mounted root (ext2 filesystem).
5503 Boot Linux and pass a flat device tree:
5506 First, U-Boot must be compiled with the appropriate defines. See the section
5507 titled "Linux Kernel Interface" above for a more in depth explanation. The
5508 following is an example of how to start a kernel and pass an updated
5514 oft=oftrees/mpc8540ads.dtb
5515 => tftp $oftaddr $oft
5516 Speed: 1000, full duplex
5518 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5519 Filename 'oftrees/mpc8540ads.dtb'.
5520 Load address: 0x300000
5523 Bytes transferred = 4106 (100a hex)
5524 => tftp $loadaddr $bootfile
5525 Speed: 1000, full duplex
5527 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5529 Load address: 0x200000
5530 Loading:############
5532 Bytes transferred = 1029407 (fb51f hex)
5537 => bootm $loadaddr - $oftaddr
5538 ## Booting image at 00200000 ...
5539 Image Name: Linux-2.6.17-dirty
5540 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5541 Data Size: 1029343 Bytes = 1005.2 kB
5542 Load Address: 00000000
5543 Entry Point: 00000000
5544 Verifying Checksum ... OK
5545 Uncompressing Kernel Image ... OK
5546 Booting using flat device tree at 0x300000
5547 Using MPC85xx ADS machine description
5548 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5552 More About U-Boot Image Types:
5553 ------------------------------
5555 U-Boot supports the following image types:
5557 "Standalone Programs" are directly runnable in the environment
5558 provided by U-Boot; it is expected that (if they behave
5559 well) you can continue to work in U-Boot after return from
5560 the Standalone Program.
5561 "OS Kernel Images" are usually images of some Embedded OS which
5562 will take over control completely. Usually these programs
5563 will install their own set of exception handlers, device
5564 drivers, set up the MMU, etc. - this means, that you cannot
5565 expect to re-enter U-Boot except by resetting the CPU.
5566 "RAMDisk Images" are more or less just data blocks, and their
5567 parameters (address, size) are passed to an OS kernel that is
5569 "Multi-File Images" contain several images, typically an OS
5570 (Linux) kernel image and one or more data images like
5571 RAMDisks. This construct is useful for instance when you want
5572 to boot over the network using BOOTP etc., where the boot
5573 server provides just a single image file, but you want to get
5574 for instance an OS kernel and a RAMDisk image.
5576 "Multi-File Images" start with a list of image sizes, each
5577 image size (in bytes) specified by an "uint32_t" in network
5578 byte order. This list is terminated by an "(uint32_t)0".
5579 Immediately after the terminating 0 follow the images, one by
5580 one, all aligned on "uint32_t" boundaries (size rounded up to
5581 a multiple of 4 bytes).
5583 "Firmware Images" are binary images containing firmware (like
5584 U-Boot or FPGA images) which usually will be programmed to
5587 "Script files" are command sequences that will be executed by
5588 U-Boot's command interpreter; this feature is especially
5589 useful when you configure U-Boot to use a real shell (hush)
5590 as command interpreter.
5592 Booting the Linux zImage:
5593 -------------------------
5595 On some platforms, it's possible to boot Linux zImage. This is done
5596 using the "bootz" command. The syntax of "bootz" command is the same
5597 as the syntax of "bootm" command.
5599 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5600 kernel with raw initrd images. The syntax is slightly different, the
5601 address of the initrd must be augmented by it's size, in the following
5602 format: "<initrd addres>:<initrd size>".
5608 One of the features of U-Boot is that you can dynamically load and
5609 run "standalone" applications, which can use some resources of
5610 U-Boot like console I/O functions or interrupt services.
5612 Two simple examples are included with the sources:
5617 'examples/hello_world.c' contains a small "Hello World" Demo
5618 application; it is automatically compiled when you build U-Boot.
5619 It's configured to run at address 0x00040004, so you can play with it
5623 ## Ready for S-Record download ...
5624 ~>examples/hello_world.srec
5625 1 2 3 4 5 6 7 8 9 10 11 ...
5626 [file transfer complete]
5628 ## Start Addr = 0x00040004
5630 => go 40004 Hello World! This is a test.
5631 ## Starting application at 0x00040004 ...
5642 Hit any key to exit ...
5644 ## Application terminated, rc = 0x0
5646 Another example, which demonstrates how to register a CPM interrupt
5647 handler with the U-Boot code, can be found in 'examples/timer.c'.
5648 Here, a CPM timer is set up to generate an interrupt every second.
5649 The interrupt service routine is trivial, just printing a '.'
5650 character, but this is just a demo program. The application can be
5651 controlled by the following keys:
5653 ? - print current values og the CPM Timer registers
5654 b - enable interrupts and start timer
5655 e - stop timer and disable interrupts
5656 q - quit application
5659 ## Ready for S-Record download ...
5660 ~>examples/timer.srec
5661 1 2 3 4 5 6 7 8 9 10 11 ...
5662 [file transfer complete]
5664 ## Start Addr = 0x00040004
5667 ## Starting application at 0x00040004 ...
5670 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5673 [q, b, e, ?] Set interval 1000000 us
5676 [q, b, e, ?] ........
5677 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5680 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5683 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5686 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5688 [q, b, e, ?] ...Stopping timer
5690 [q, b, e, ?] ## Application terminated, rc = 0x0
5696 Over time, many people have reported problems when trying to use the
5697 "minicom" terminal emulation program for serial download. I (wd)
5698 consider minicom to be broken, and recommend not to use it. Under
5699 Unix, I recommend to use C-Kermit for general purpose use (and
5700 especially for kermit binary protocol download ("loadb" command), and
5701 use "cu" for S-Record download ("loads" command). See
5702 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5703 for help with kermit.
5706 Nevertheless, if you absolutely want to use it try adding this
5707 configuration to your "File transfer protocols" section:
5709 Name Program Name U/D FullScr IO-Red. Multi
5710 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5711 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5717 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5718 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5720 Building requires a cross environment; it is known to work on
5721 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5722 need gmake since the Makefiles are not compatible with BSD make).
5723 Note that the cross-powerpc package does not install include files;
5724 attempting to build U-Boot will fail because <machine/ansi.h> is
5725 missing. This file has to be installed and patched manually:
5727 # cd /usr/pkg/cross/powerpc-netbsd/include
5729 # ln -s powerpc machine
5730 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5731 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5733 Native builds *don't* work due to incompatibilities between native
5734 and U-Boot include files.
5736 Booting assumes that (the first part of) the image booted is a
5737 stage-2 loader which in turn loads and then invokes the kernel
5738 proper. Loader sources will eventually appear in the NetBSD source
5739 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5740 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5743 Implementation Internals:
5744 =========================
5746 The following is not intended to be a complete description of every
5747 implementation detail. However, it should help to understand the
5748 inner workings of U-Boot and make it easier to port it to custom
5752 Initial Stack, Global Data:
5753 ---------------------------
5755 The implementation of U-Boot is complicated by the fact that U-Boot
5756 starts running out of ROM (flash memory), usually without access to
5757 system RAM (because the memory controller is not initialized yet).
5758 This means that we don't have writable Data or BSS segments, and BSS
5759 is not initialized as zero. To be able to get a C environment working
5760 at all, we have to allocate at least a minimal stack. Implementation
5761 options for this are defined and restricted by the CPU used: Some CPU
5762 models provide on-chip memory (like the IMMR area on MPC8xx and
5763 MPC826x processors), on others (parts of) the data cache can be
5764 locked as (mis-) used as memory, etc.
5766 Chris Hallinan posted a good summary of these issues to the
5767 U-Boot mailing list:
5769 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5770 From: "Chris Hallinan" <clh@net1plus.com>
5771 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5774 Correct me if I'm wrong, folks, but the way I understand it
5775 is this: Using DCACHE as initial RAM for Stack, etc, does not
5776 require any physical RAM backing up the cache. The cleverness
5777 is that the cache is being used as a temporary supply of
5778 necessary storage before the SDRAM controller is setup. It's
5779 beyond the scope of this list to explain the details, but you
5780 can see how this works by studying the cache architecture and
5781 operation in the architecture and processor-specific manuals.
5783 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5784 is another option for the system designer to use as an
5785 initial stack/RAM area prior to SDRAM being available. Either
5786 option should work for you. Using CS 4 should be fine if your
5787 board designers haven't used it for something that would
5788 cause you grief during the initial boot! It is frequently not
5791 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5792 with your processor/board/system design. The default value
5793 you will find in any recent u-boot distribution in
5794 walnut.h should work for you. I'd set it to a value larger
5795 than your SDRAM module. If you have a 64MB SDRAM module, set
5796 it above 400_0000. Just make sure your board has no resources
5797 that are supposed to respond to that address! That code in
5798 start.S has been around a while and should work as is when
5799 you get the config right.
5804 It is essential to remember this, since it has some impact on the C
5805 code for the initialization procedures:
5807 * Initialized global data (data segment) is read-only. Do not attempt
5810 * Do not use any uninitialized global data (or implicitely initialized
5811 as zero data - BSS segment) at all - this is undefined, initiali-
5812 zation is performed later (when relocating to RAM).
5814 * Stack space is very limited. Avoid big data buffers or things like
5817 Having only the stack as writable memory limits means we cannot use
5818 normal global data to share information beween the code. But it
5819 turned out that the implementation of U-Boot can be greatly
5820 simplified by making a global data structure (gd_t) available to all
5821 functions. We could pass a pointer to this data as argument to _all_
5822 functions, but this would bloat the code. Instead we use a feature of
5823 the GCC compiler (Global Register Variables) to share the data: we
5824 place a pointer (gd) to the global data into a register which we
5825 reserve for this purpose.
5827 When choosing a register for such a purpose we are restricted by the
5828 relevant (E)ABI specifications for the current architecture, and by
5829 GCC's implementation.
5831 For PowerPC, the following registers have specific use:
5833 R2: reserved for system use
5834 R3-R4: parameter passing and return values
5835 R5-R10: parameter passing
5836 R13: small data area pointer
5840 (U-Boot also uses R12 as internal GOT pointer. r12
5841 is a volatile register so r12 needs to be reset when
5842 going back and forth between asm and C)
5844 ==> U-Boot will use R2 to hold a pointer to the global data
5846 Note: on PPC, we could use a static initializer (since the
5847 address of the global data structure is known at compile time),
5848 but it turned out that reserving a register results in somewhat
5849 smaller code - although the code savings are not that big (on
5850 average for all boards 752 bytes for the whole U-Boot image,
5851 624 text + 127 data).
5853 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5854 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5856 ==> U-Boot will use P3 to hold a pointer to the global data
5858 On ARM, the following registers are used:
5860 R0: function argument word/integer result
5861 R1-R3: function argument word
5862 R9: platform specific
5863 R10: stack limit (used only if stack checking is enabled)
5864 R11: argument (frame) pointer
5865 R12: temporary workspace
5868 R15: program counter
5870 ==> U-Boot will use R9 to hold a pointer to the global data
5872 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5874 On Nios II, the ABI is documented here:
5875 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5877 ==> U-Boot will use gp to hold a pointer to the global data
5879 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5880 to access small data sections, so gp is free.
5882 On NDS32, the following registers are used:
5884 R0-R1: argument/return
5886 R15: temporary register for assembler
5887 R16: trampoline register
5888 R28: frame pointer (FP)
5889 R29: global pointer (GP)
5890 R30: link register (LP)
5891 R31: stack pointer (SP)
5892 PC: program counter (PC)
5894 ==> U-Boot will use R10 to hold a pointer to the global data
5896 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5897 or current versions of GCC may "optimize" the code too much.
5902 U-Boot runs in system state and uses physical addresses, i.e. the
5903 MMU is not used either for address mapping nor for memory protection.
5905 The available memory is mapped to fixed addresses using the memory
5906 controller. In this process, a contiguous block is formed for each
5907 memory type (Flash, SDRAM, SRAM), even when it consists of several
5908 physical memory banks.
5910 U-Boot is installed in the first 128 kB of the first Flash bank (on
5911 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5912 booting and sizing and initializing DRAM, the code relocates itself
5913 to the upper end of DRAM. Immediately below the U-Boot code some
5914 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5915 configuration setting]. Below that, a structure with global Board
5916 Info data is placed, followed by the stack (growing downward).
5918 Additionally, some exception handler code is copied to the low 8 kB
5919 of DRAM (0x00000000 ... 0x00001FFF).
5921 So a typical memory configuration with 16 MB of DRAM could look like
5924 0x0000 0000 Exception Vector code
5927 0x0000 2000 Free for Application Use
5933 0x00FB FF20 Monitor Stack (Growing downward)
5934 0x00FB FFAC Board Info Data and permanent copy of global data
5935 0x00FC 0000 Malloc Arena
5938 0x00FE 0000 RAM Copy of Monitor Code
5939 ... eventually: LCD or video framebuffer
5940 ... eventually: pRAM (Protected RAM - unchanged by reset)
5941 0x00FF FFFF [End of RAM]
5944 System Initialization:
5945 ----------------------
5947 In the reset configuration, U-Boot starts at the reset entry point
5948 (on most PowerPC systems at address 0x00000100). Because of the reset
5949 configuration for CS0# this is a mirror of the onboard Flash memory.
5950 To be able to re-map memory U-Boot then jumps to its link address.
5951 To be able to implement the initialization code in C, a (small!)
5952 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5953 which provide such a feature like MPC8xx or MPC8260), or in a locked
5954 part of the data cache. After that, U-Boot initializes the CPU core,
5955 the caches and the SIU.
5957 Next, all (potentially) available memory banks are mapped using a
5958 preliminary mapping. For example, we put them on 512 MB boundaries
5959 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5960 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5961 programmed for SDRAM access. Using the temporary configuration, a
5962 simple memory test is run that determines the size of the SDRAM
5965 When there is more than one SDRAM bank, and the banks are of
5966 different size, the largest is mapped first. For equal size, the first
5967 bank (CS2#) is mapped first. The first mapping is always for address
5968 0x00000000, with any additional banks following immediately to create
5969 contiguous memory starting from 0.
5971 Then, the monitor installs itself at the upper end of the SDRAM area
5972 and allocates memory for use by malloc() and for the global Board
5973 Info data; also, the exception vector code is copied to the low RAM
5974 pages, and the final stack is set up.
5976 Only after this relocation will you have a "normal" C environment;
5977 until that you are restricted in several ways, mostly because you are
5978 running from ROM, and because the code will have to be relocated to a
5982 U-Boot Porting Guide:
5983 ----------------------
5985 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5989 int main(int argc, char *argv[])
5991 sighandler_t no_more_time;
5993 signal(SIGALRM, no_more_time);
5994 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5996 if (available_money > available_manpower) {
5997 Pay consultant to port U-Boot;
6001 Download latest U-Boot source;
6003 Subscribe to u-boot mailing list;
6006 email("Hi, I am new to U-Boot, how do I get started?");
6009 Read the README file in the top level directory;
6010 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6011 Read applicable doc/*.README;
6012 Read the source, Luke;
6013 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6016 if (available_money > toLocalCurrency ($2500))
6019 Add a lot of aggravation and time;
6021 if (a similar board exists) { /* hopefully... */
6022 cp -a board/<similar> board/<myboard>
6023 cp include/configs/<similar>.h include/configs/<myboard>.h
6025 Create your own board support subdirectory;
6026 Create your own board include/configs/<myboard>.h file;
6028 Edit new board/<myboard> files
6029 Edit new include/configs/<myboard>.h
6034 Add / modify source code;
6038 email("Hi, I am having problems...");
6040 Send patch file to the U-Boot email list;
6041 if (reasonable critiques)
6042 Incorporate improvements from email list code review;
6044 Defend code as written;
6050 void no_more_time (int sig)
6059 All contributions to U-Boot should conform to the Linux kernel
6060 coding style; see the file "Documentation/CodingStyle" and the script
6061 "scripts/Lindent" in your Linux kernel source directory.
6063 Source files originating from a different project (for example the
6064 MTD subsystem) are generally exempt from these guidelines and are not
6065 reformated to ease subsequent migration to newer versions of those
6068 Please note that U-Boot is implemented in C (and to some small parts in
6069 Assembler); no C++ is used, so please do not use C++ style comments (//)
6072 Please also stick to the following formatting rules:
6073 - remove any trailing white space
6074 - use TAB characters for indentation and vertical alignment, not spaces
6075 - make sure NOT to use DOS '\r\n' line feeds
6076 - do not add more than 2 consecutive empty lines to source files
6077 - do not add trailing empty lines to source files
6079 Submissions which do not conform to the standards may be returned
6080 with a request to reformat the changes.
6086 Since the number of patches for U-Boot is growing, we need to
6087 establish some rules. Submissions which do not conform to these rules
6088 may be rejected, even when they contain important and valuable stuff.
6090 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6092 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6093 see http://lists.denx.de/mailman/listinfo/u-boot
6095 When you send a patch, please include the following information with
6098 * For bug fixes: a description of the bug and how your patch fixes
6099 this bug. Please try to include a way of demonstrating that the
6100 patch actually fixes something.
6102 * For new features: a description of the feature and your
6105 * A CHANGELOG entry as plaintext (separate from the patch)
6107 * For major contributions, your entry to the CREDITS file
6109 * When you add support for a new board, don't forget to add a
6110 maintainer e-mail address to the boards.cfg file, too.
6112 * If your patch adds new configuration options, don't forget to
6113 document these in the README file.
6115 * The patch itself. If you are using git (which is *strongly*
6116 recommended) you can easily generate the patch using the
6117 "git format-patch". If you then use "git send-email" to send it to
6118 the U-Boot mailing list, you will avoid most of the common problems
6119 with some other mail clients.
6121 If you cannot use git, use "diff -purN OLD NEW". If your version of
6122 diff does not support these options, then get the latest version of
6125 The current directory when running this command shall be the parent
6126 directory of the U-Boot source tree (i. e. please make sure that
6127 your patch includes sufficient directory information for the
6130 We prefer patches as plain text. MIME attachments are discouraged,
6131 and compressed attachments must not be used.
6133 * If one logical set of modifications affects or creates several
6134 files, all these changes shall be submitted in a SINGLE patch file.
6136 * Changesets that contain different, unrelated modifications shall be
6137 submitted as SEPARATE patches, one patch per changeset.
6142 * Before sending the patch, run the MAKEALL script on your patched
6143 source tree and make sure that no errors or warnings are reported
6144 for any of the boards.
6146 * Keep your modifications to the necessary minimum: A patch
6147 containing several unrelated changes or arbitrary reformats will be
6148 returned with a request to re-formatting / split it.
6150 * If you modify existing code, make sure that your new code does not
6151 add to the memory footprint of the code ;-) Small is beautiful!
6152 When adding new features, these should compile conditionally only
6153 (using #ifdef), and the resulting code with the new feature
6154 disabled must not need more memory than the old code without your
6157 * Remember that there is a size limit of 100 kB per message on the
6158 u-boot mailing list. Bigger patches will be moderated. If they are
6159 reasonable and not too big, they will be acknowledged. But patches
6160 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob