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
508 CONFIG_SYS_FSL_DDR_BE
509 Defines the DDR controller register space as Big Endian
511 CONFIG_SYS_FSL_DDR_LE
512 Defines the DDR controller register space as Little Endian
514 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
515 Physical address from the view of DDR controllers. It is the
516 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
517 it could be different for ARM SoCs.
519 CONFIG_SYS_FSL_DDR_INTLV_256B
520 DDR controller interleaving on 256-byte. This is a special
521 interleaving mode, handled by Dickens for Freescale layerscape
524 - Intel Monahans options:
525 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
527 Defines the Monahans run mode to oscillator
528 ratio. Valid values are 8, 16, 24, 31. The core
529 frequency is this value multiplied by 13 MHz.
531 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
533 Defines the Monahans turbo mode to oscillator
534 ratio. Valid values are 1 (default if undefined) and
535 2. The core frequency as calculated above is multiplied
539 CONFIG_SYS_INIT_SP_OFFSET
541 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
542 pointer. This is needed for the temporary stack before
545 CONFIG_SYS_MIPS_CACHE_MODE
547 Cache operation mode for the MIPS CPU.
548 See also arch/mips/include/asm/mipsregs.h.
550 CONF_CM_CACHABLE_NO_WA
553 CONF_CM_CACHABLE_NONCOHERENT
557 CONF_CM_CACHABLE_ACCELERATED
559 CONFIG_SYS_XWAY_EBU_BOOTCFG
561 Special option for Lantiq XWAY SoCs for booting from NOR flash.
562 See also arch/mips/cpu/mips32/start.S.
564 CONFIG_XWAY_SWAP_BYTES
566 Enable compilation of tools/xway-swap-bytes needed for Lantiq
567 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
568 be swapped if a flash programmer is used.
571 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
573 Select high exception vectors of the ARM core, e.g., do not
574 clear the V bit of the c1 register of CP15.
576 CONFIG_SYS_THUMB_BUILD
578 Use this flag to build U-Boot using the Thumb instruction
579 set for ARM architectures. Thumb instruction set provides
580 better code density. For ARM architectures that support
581 Thumb2 this flag will result in Thumb2 code generated by
584 CONFIG_ARM_ERRATA_716044
585 CONFIG_ARM_ERRATA_742230
586 CONFIG_ARM_ERRATA_743622
587 CONFIG_ARM_ERRATA_751472
588 CONFIG_ARM_ERRATA_794072
589 CONFIG_ARM_ERRATA_761320
591 If set, the workarounds for these ARM errata are applied early
592 during U-Boot startup. Note that these options force the
593 workarounds to be applied; no CPU-type/version detection
594 exists, unlike the similar options in the Linux kernel. Do not
595 set these options unless they apply!
600 The frequency of the timer returned by get_timer().
601 get_timer() must operate in milliseconds and this CONFIG
602 option must be set to 1000.
604 - Linux Kernel Interface:
607 U-Boot stores all clock information in Hz
608 internally. For binary compatibility with older Linux
609 kernels (which expect the clocks passed in the
610 bd_info data to be in MHz) the environment variable
611 "clocks_in_mhz" can be defined so that U-Boot
612 converts clock data to MHZ before passing it to the
614 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
615 "clocks_in_mhz=1" is automatically included in the
618 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
620 When transferring memsize parameter to linux, some versions
621 expect it to be in bytes, others in MB.
622 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
626 New kernel versions are expecting firmware settings to be
627 passed using flattened device trees (based on open firmware
631 * New libfdt-based support
632 * Adds the "fdt" command
633 * The bootm command automatically updates the fdt
635 OF_CPU - The proper name of the cpus node (only required for
636 MPC512X and MPC5xxx based boards).
637 OF_SOC - The proper name of the soc node (only required for
638 MPC512X and MPC5xxx based boards).
639 OF_TBCLK - The timebase frequency.
640 OF_STDOUT_PATH - The path to the console device
642 boards with QUICC Engines require OF_QE to set UCC MAC
645 CONFIG_OF_BOARD_SETUP
647 Board code has addition modification that it wants to make
648 to the flat device tree before handing it off to the kernel
652 This define fills in the correct boot CPU in the boot
653 param header, the default value is zero if undefined.
657 U-Boot can detect if an IDE device is present or not.
658 If not, and this new config option is activated, U-Boot
659 removes the ATA node from the DTS before booting Linux,
660 so the Linux IDE driver does not probe the device and
661 crash. This is needed for buggy hardware (uc101) where
662 no pull down resistor is connected to the signal IDE5V_DD7.
664 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
666 This setting is mandatory for all boards that have only one
667 machine type and must be used to specify the machine type
668 number as it appears in the ARM machine registry
669 (see http://www.arm.linux.org.uk/developer/machines/).
670 Only boards that have multiple machine types supported
671 in a single configuration file and the machine type is
672 runtime discoverable, do not have to use this setting.
674 - vxWorks boot parameters:
676 bootvx constructs a valid bootline using the following
677 environments variables: bootfile, ipaddr, serverip, hostname.
678 It loads the vxWorks image pointed bootfile.
680 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
681 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
682 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
683 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
685 CONFIG_SYS_VXWORKS_ADD_PARAMS
687 Add it at the end of the bootline. E.g "u=username pw=secret"
689 Note: If a "bootargs" environment is defined, it will overwride
690 the defaults discussed just above.
692 - Cache Configuration:
693 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
694 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
695 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
697 - Cache Configuration for ARM:
698 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
700 CONFIG_SYS_PL310_BASE - Physical base address of PL310
701 controller register space
706 Define this if you want support for Amba PrimeCell PL010 UARTs.
710 Define this if you want support for Amba PrimeCell PL011 UARTs.
714 If you have Amba PrimeCell PL011 UARTs, set this variable to
715 the clock speed of the UARTs.
719 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
720 define this to a list of base addresses for each (supported)
721 port. See e.g. include/configs/versatile.h
723 CONFIG_PL011_SERIAL_RLCR
725 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
726 have separate receive and transmit line control registers. Set
727 this variable to initialize the extra register.
729 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
731 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
732 boot loader that has already initialized the UART. Define this
733 variable to flush the UART at init time.
737 Depending on board, define exactly one serial port
738 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
739 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
740 console by defining CONFIG_8xx_CONS_NONE
742 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
743 port routines must be defined elsewhere
744 (i.e. serial_init(), serial_getc(), ...)
747 Enables console device for a color framebuffer. Needs following
748 defines (cf. smiLynxEM, i8042)
749 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
751 VIDEO_HW_RECTFILL graphic chip supports
754 VIDEO_HW_BITBLT graphic chip supports
755 bit-blit (cf. smiLynxEM)
756 VIDEO_VISIBLE_COLS visible pixel columns
758 VIDEO_VISIBLE_ROWS visible pixel rows
759 VIDEO_PIXEL_SIZE bytes per pixel
760 VIDEO_DATA_FORMAT graphic data format
761 (0-5, cf. cfb_console.c)
762 VIDEO_FB_ADRS framebuffer address
763 VIDEO_KBD_INIT_FCT keyboard int fct
764 (i.e. i8042_kbd_init())
765 VIDEO_TSTC_FCT test char fct
767 VIDEO_GETC_FCT get char fct
769 CONFIG_CONSOLE_CURSOR cursor drawing on/off
770 (requires blink timer
772 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
773 CONFIG_CONSOLE_TIME display time/date info in
775 (requires CONFIG_CMD_DATE)
776 CONFIG_VIDEO_LOGO display Linux logo in
778 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
779 linux_logo.h for logo.
780 Requires CONFIG_VIDEO_LOGO
781 CONFIG_CONSOLE_EXTRA_INFO
782 additional board info beside
785 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
786 a limited number of ANSI escape sequences (cursor control,
787 erase functions and limited graphics rendition control).
789 When CONFIG_CFB_CONSOLE is defined, video console is
790 default i/o. Serial console can be forced with
791 environment 'console=serial'.
793 When CONFIG_SILENT_CONSOLE is defined, all console
794 messages (by U-Boot and Linux!) can be silenced with
795 the "silent" environment variable. See
796 doc/README.silent for more information.
798 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
800 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
804 CONFIG_BAUDRATE - in bps
805 Select one of the baudrates listed in
806 CONFIG_SYS_BAUDRATE_TABLE, see below.
807 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
809 - Console Rx buffer length
810 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
811 the maximum receive buffer length for the SMC.
812 This option is actual only for 82xx and 8xx possible.
813 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
814 must be defined, to setup the maximum idle timeout for
817 - Pre-Console Buffer:
818 Prior to the console being initialised (i.e. serial UART
819 initialised etc) all console output is silently discarded.
820 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
821 buffer any console messages prior to the console being
822 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
823 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
824 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
825 bytes are output before the console is initialised, the
826 earlier bytes are discarded.
828 'Sane' compilers will generate smaller code if
829 CONFIG_PRE_CON_BUF_SZ is a power of 2
831 - Safe printf() functions
832 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
833 the printf() functions. These are defined in
834 include/vsprintf.h and include snprintf(), vsnprintf() and
835 so on. Code size increase is approximately 300-500 bytes.
836 If this option is not given then these functions will
837 silently discard their buffer size argument - this means
838 you are not getting any overflow checking in this case.
840 - Boot Delay: CONFIG_BOOTDELAY - in seconds
841 Delay before automatically booting the default image;
842 set to -1 to disable autoboot.
843 set to -2 to autoboot with no delay and not check for abort
844 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
846 See doc/README.autoboot for these options that
847 work with CONFIG_BOOTDELAY. None are required.
848 CONFIG_BOOT_RETRY_TIME
849 CONFIG_BOOT_RETRY_MIN
850 CONFIG_AUTOBOOT_KEYED
851 CONFIG_AUTOBOOT_PROMPT
852 CONFIG_AUTOBOOT_DELAY_STR
853 CONFIG_AUTOBOOT_STOP_STR
854 CONFIG_AUTOBOOT_DELAY_STR2
855 CONFIG_AUTOBOOT_STOP_STR2
856 CONFIG_ZERO_BOOTDELAY_CHECK
857 CONFIG_RESET_TO_RETRY
861 Only needed when CONFIG_BOOTDELAY is enabled;
862 define a command string that is automatically executed
863 when no character is read on the console interface
864 within "Boot Delay" after reset.
867 This can be used to pass arguments to the bootm
868 command. The value of CONFIG_BOOTARGS goes into the
869 environment value "bootargs".
871 CONFIG_RAMBOOT and CONFIG_NFSBOOT
872 The value of these goes into the environment as
873 "ramboot" and "nfsboot" respectively, and can be used
874 as a convenience, when switching between booting from
878 CONFIG_BOOTCOUNT_LIMIT
879 Implements a mechanism for detecting a repeating reboot
881 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
884 If no softreset save registers are found on the hardware
885 "bootcount" is stored in the environment. To prevent a
886 saveenv on all reboots, the environment variable
887 "upgrade_available" is used. If "upgrade_available" is
888 0, "bootcount" is always 0, if "upgrade_available" is
889 1 "bootcount" is incremented in the environment.
890 So the Userspace Applikation must set the "upgrade_available"
891 and "bootcount" variable to 0, if a boot was successfully.
896 When this option is #defined, the existence of the
897 environment variable "preboot" will be checked
898 immediately before starting the CONFIG_BOOTDELAY
899 countdown and/or running the auto-boot command resp.
900 entering interactive mode.
902 This feature is especially useful when "preboot" is
903 automatically generated or modified. For an example
904 see the LWMON board specific code: here "preboot" is
905 modified when the user holds down a certain
906 combination of keys on the (special) keyboard when
909 - Serial Download Echo Mode:
911 If defined to 1, all characters received during a
912 serial download (using the "loads" command) are
913 echoed back. This might be needed by some terminal
914 emulations (like "cu"), but may as well just take
915 time on others. This setting #define's the initial
916 value of the "loads_echo" environment variable.
918 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
920 Select one of the baudrates listed in
921 CONFIG_SYS_BAUDRATE_TABLE, see below.
924 Monitor commands can be included or excluded
925 from the build by using the #include files
926 <config_cmd_all.h> and #undef'ing unwanted
927 commands, or using <config_cmd_default.h>
928 and augmenting with additional #define's
931 The default command configuration includes all commands
932 except those marked below with a "*".
934 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
935 CONFIG_CMD_ASKENV * ask for env variable
936 CONFIG_CMD_BDI bdinfo
937 CONFIG_CMD_BEDBUG * Include BedBug Debugger
938 CONFIG_CMD_BMP * BMP support
939 CONFIG_CMD_BSP * Board specific commands
940 CONFIG_CMD_BOOTD bootd
941 CONFIG_CMD_CACHE * icache, dcache
942 CONFIG_CMD_CLK * clock command support
943 CONFIG_CMD_CONSOLE coninfo
944 CONFIG_CMD_CRC32 * crc32
945 CONFIG_CMD_DATE * support for RTC, date/time...
946 CONFIG_CMD_DHCP * DHCP support
947 CONFIG_CMD_DIAG * Diagnostics
948 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
949 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
950 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
951 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
952 CONFIG_CMD_DTT * Digital Therm and Thermostat
953 CONFIG_CMD_ECHO echo arguments
954 CONFIG_CMD_EDITENV edit env variable
955 CONFIG_CMD_EEPROM * EEPROM read/write support
956 CONFIG_CMD_ELF * bootelf, bootvx
957 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
958 CONFIG_CMD_ENV_FLAGS * display details about env flags
959 CONFIG_CMD_ENV_EXISTS * check existence of env variable
960 CONFIG_CMD_EXPORTENV * export the environment
961 CONFIG_CMD_EXT2 * ext2 command support
962 CONFIG_CMD_EXT4 * ext4 command support
963 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
964 that work for multiple fs types
965 CONFIG_CMD_SAVEENV saveenv
966 CONFIG_CMD_FDC * Floppy Disk Support
967 CONFIG_CMD_FAT * FAT command support
968 CONFIG_CMD_FLASH flinfo, erase, protect
969 CONFIG_CMD_FPGA FPGA device initialization support
970 CONFIG_CMD_FUSE * Device fuse support
971 CONFIG_CMD_GETTIME * Get time since boot
972 CONFIG_CMD_GO * the 'go' command (exec code)
973 CONFIG_CMD_GREPENV * search environment
974 CONFIG_CMD_HASH * calculate hash / digest
975 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
976 CONFIG_CMD_I2C * I2C serial bus support
977 CONFIG_CMD_IDE * IDE harddisk support
978 CONFIG_CMD_IMI iminfo
979 CONFIG_CMD_IMLS List all images found in NOR flash
980 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
981 CONFIG_CMD_IMMAP * IMMR dump support
982 CONFIG_CMD_IMPORTENV * import an environment
983 CONFIG_CMD_INI * import data from an ini file into the env
984 CONFIG_CMD_IRQ * irqinfo
985 CONFIG_CMD_ITEST Integer/string test of 2 values
986 CONFIG_CMD_JFFS2 * JFFS2 Support
987 CONFIG_CMD_KGDB * kgdb
988 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
989 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
991 CONFIG_CMD_LOADB loadb
992 CONFIG_CMD_LOADS loads
993 CONFIG_CMD_MD5SUM * print md5 message digest
994 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
995 CONFIG_CMD_MEMINFO * Display detailed memory information
996 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
998 CONFIG_CMD_MEMTEST * mtest
999 CONFIG_CMD_MISC Misc functions like sleep etc
1000 CONFIG_CMD_MMC * MMC memory mapped support
1001 CONFIG_CMD_MII * MII utility commands
1002 CONFIG_CMD_MTDPARTS * MTD partition support
1003 CONFIG_CMD_NAND * NAND support
1004 CONFIG_CMD_NET bootp, tftpboot, rarpboot
1005 CONFIG_CMD_NFS NFS support
1006 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
1007 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
1008 CONFIG_CMD_PCI * pciinfo
1009 CONFIG_CMD_PCMCIA * PCMCIA support
1010 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
1012 CONFIG_CMD_PORTIO * Port I/O
1013 CONFIG_CMD_READ * Read raw data from partition
1014 CONFIG_CMD_REGINFO * Register dump
1015 CONFIG_CMD_RUN run command in env variable
1016 CONFIG_CMD_SANDBOX * sb command to access sandbox features
1017 CONFIG_CMD_SAVES * save S record dump
1018 CONFIG_CMD_SCSI * SCSI Support
1019 CONFIG_CMD_SDRAM * print SDRAM configuration information
1020 (requires CONFIG_CMD_I2C)
1021 CONFIG_CMD_SETGETDCR Support for DCR Register access
1023 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1024 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1025 (requires CONFIG_CMD_MEMORY)
1026 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1027 CONFIG_CMD_SOURCE "source" command Support
1028 CONFIG_CMD_SPI * SPI serial bus support
1029 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1030 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1031 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1032 CONFIG_CMD_TIMER * access to the system tick timer
1033 CONFIG_CMD_USB * USB support
1034 CONFIG_CMD_CDP * Cisco Discover Protocol support
1035 CONFIG_CMD_MFSL * Microblaze FSL support
1036 CONFIG_CMD_XIMG Load part of Multi Image
1037 CONFIG_CMD_UUID * Generate random UUID or GUID string
1039 EXAMPLE: If you want all functions except of network
1040 support you can write:
1042 #include "config_cmd_all.h"
1043 #undef CONFIG_CMD_NET
1046 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1048 Note: Don't enable the "icache" and "dcache" commands
1049 (configuration option CONFIG_CMD_CACHE) unless you know
1050 what you (and your U-Boot users) are doing. Data
1051 cache cannot be enabled on systems like the 8xx or
1052 8260 (where accesses to the IMMR region must be
1053 uncached), and it cannot be disabled on all other
1054 systems where we (mis-) use the data cache to hold an
1055 initial stack and some data.
1058 XXX - this list needs to get updated!
1060 - Regular expression support:
1062 If this variable is defined, U-Boot is linked against
1063 the SLRE (Super Light Regular Expression) library,
1064 which adds regex support to some commands, as for
1065 example "env grep" and "setexpr".
1069 If this variable is defined, U-Boot will use a device tree
1070 to configure its devices, instead of relying on statically
1071 compiled #defines in the board file. This option is
1072 experimental and only available on a few boards. The device
1073 tree is available in the global data as gd->fdt_blob.
1075 U-Boot needs to get its device tree from somewhere. This can
1076 be done using one of the two options below:
1079 If this variable is defined, U-Boot will embed a device tree
1080 binary in its image. This device tree file should be in the
1081 board directory and called <soc>-<board>.dts. The binary file
1082 is then picked up in board_init_f() and made available through
1083 the global data structure as gd->blob.
1086 If this variable is defined, U-Boot will build a device tree
1087 binary. It will be called u-boot.dtb. Architecture-specific
1088 code will locate it at run-time. Generally this works by:
1090 cat u-boot.bin u-boot.dtb >image.bin
1092 and in fact, U-Boot does this for you, creating a file called
1093 u-boot-dtb.bin which is useful in the common case. You can
1094 still use the individual files if you need something more
1099 If this variable is defined, it enables watchdog
1100 support for the SoC. There must be support in the SoC
1101 specific code for a watchdog. For the 8xx and 8260
1102 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1103 register. When supported for a specific SoC is
1104 available, then no further board specific code should
1105 be needed to use it.
1108 When using a watchdog circuitry external to the used
1109 SoC, then define this variable and provide board
1110 specific code for the "hw_watchdog_reset" function.
1113 CONFIG_VERSION_VARIABLE
1114 If this variable is defined, an environment variable
1115 named "ver" is created by U-Boot showing the U-Boot
1116 version as printed by the "version" command.
1117 Any change to this variable will be reverted at the
1122 When CONFIG_CMD_DATE is selected, the type of the RTC
1123 has to be selected, too. Define exactly one of the
1126 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1127 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1128 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1129 CONFIG_RTC_MC146818 - use MC146818 RTC
1130 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1131 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1132 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1133 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1134 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1135 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1136 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1137 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1140 Note that if the RTC uses I2C, then the I2C interface
1141 must also be configured. See I2C Support, below.
1144 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1146 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1147 chip-ngpio pairs that tell the PCA953X driver the number of
1148 pins supported by a particular chip.
1150 Note that if the GPIO device uses I2C, then the I2C interface
1151 must also be configured. See I2C Support, below.
1153 - Timestamp Support:
1155 When CONFIG_TIMESTAMP is selected, the timestamp
1156 (date and time) of an image is printed by image
1157 commands like bootm or iminfo. This option is
1158 automatically enabled when you select CONFIG_CMD_DATE .
1160 - Partition Labels (disklabels) Supported:
1161 Zero or more of the following:
1162 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1163 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1164 Intel architecture, USB sticks, etc.
1165 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1166 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1167 bootloader. Note 2TB partition limit; see
1169 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1171 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1172 CONFIG_CMD_SCSI) you must configure support for at
1173 least one non-MTD partition type as well.
1176 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1177 board configurations files but used nowhere!
1179 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1180 be performed by calling the function
1181 ide_set_reset(int reset)
1182 which has to be defined in a board specific file
1187 Set this to enable ATAPI support.
1192 Set this to enable support for disks larger than 137GB
1193 Also look at CONFIG_SYS_64BIT_LBA.
1194 Whithout these , LBA48 support uses 32bit variables and will 'only'
1195 support disks up to 2.1TB.
1197 CONFIG_SYS_64BIT_LBA:
1198 When enabled, makes the IDE subsystem use 64bit sector addresses.
1202 At the moment only there is only support for the
1203 SYM53C8XX SCSI controller; define
1204 CONFIG_SCSI_SYM53C8XX to enable it.
1206 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1207 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1208 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1209 maximum numbers of LUNs, SCSI ID's and target
1211 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1213 The environment variable 'scsidevs' is set to the number of
1214 SCSI devices found during the last scan.
1216 - NETWORK Support (PCI):
1218 Support for Intel 8254x/8257x gigabit chips.
1221 Utility code for direct access to the SPI bus on Intel 8257x.
1222 This does not do anything useful unless you set at least one
1223 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1225 CONFIG_E1000_SPI_GENERIC
1226 Allow generic access to the SPI bus on the Intel 8257x, for
1227 example with the "sspi" command.
1230 Management command for E1000 devices. When used on devices
1231 with SPI support you can reprogram the EEPROM from U-Boot.
1233 CONFIG_E1000_FALLBACK_MAC
1234 default MAC for empty EEPROM after production.
1237 Support for Intel 82557/82559/82559ER chips.
1238 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1239 write routine for first time initialisation.
1242 Support for Digital 2114x chips.
1243 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1244 modem chip initialisation (KS8761/QS6611).
1247 Support for National dp83815 chips.
1250 Support for National dp8382[01] gigabit chips.
1252 - NETWORK Support (other):
1254 CONFIG_DRIVER_AT91EMAC
1255 Support for AT91RM9200 EMAC.
1258 Define this to use reduced MII inteface
1260 CONFIG_DRIVER_AT91EMAC_QUIET
1261 If this defined, the driver is quiet.
1262 The driver doen't show link status messages.
1264 CONFIG_CALXEDA_XGMAC
1265 Support for the Calxeda XGMAC device
1268 Support for SMSC's LAN91C96 chips.
1270 CONFIG_LAN91C96_BASE
1271 Define this to hold the physical address
1272 of the LAN91C96's I/O space
1274 CONFIG_LAN91C96_USE_32_BIT
1275 Define this to enable 32 bit addressing
1278 Support for SMSC's LAN91C111 chip
1280 CONFIG_SMC91111_BASE
1281 Define this to hold the physical address
1282 of the device (I/O space)
1284 CONFIG_SMC_USE_32_BIT
1285 Define this if data bus is 32 bits
1287 CONFIG_SMC_USE_IOFUNCS
1288 Define this to use i/o functions instead of macros
1289 (some hardware wont work with macros)
1291 CONFIG_DRIVER_TI_EMAC
1292 Support for davinci emac
1294 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1295 Define this if you have more then 3 PHYs.
1298 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1300 CONFIG_FTGMAC100_EGIGA
1301 Define this to use GE link update with gigabit PHY.
1302 Define this if FTGMAC100 is connected to gigabit PHY.
1303 If your system has 10/100 PHY only, it might not occur
1304 wrong behavior. Because PHY usually return timeout or
1305 useless data when polling gigabit status and gigabit
1306 control registers. This behavior won't affect the
1307 correctnessof 10/100 link speed update.
1310 Support for SMSC's LAN911x and LAN921x chips
1313 Define this to hold the physical address
1314 of the device (I/O space)
1316 CONFIG_SMC911X_32_BIT
1317 Define this if data bus is 32 bits
1319 CONFIG_SMC911X_16_BIT
1320 Define this if data bus is 16 bits. If your processor
1321 automatically converts one 32 bit word to two 16 bit
1322 words you may also try CONFIG_SMC911X_32_BIT.
1325 Support for Renesas on-chip Ethernet controller
1327 CONFIG_SH_ETHER_USE_PORT
1328 Define the number of ports to be used
1330 CONFIG_SH_ETHER_PHY_ADDR
1331 Define the ETH PHY's address
1333 CONFIG_SH_ETHER_CACHE_WRITEBACK
1334 If this option is set, the driver enables cache flush.
1338 Support TPM devices.
1341 Support for i2c bus TPM devices. Only one device
1342 per system is supported at this time.
1344 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1345 Define the the i2c bus number for the TPM device
1347 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1348 Define the TPM's address on the i2c bus
1350 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1351 Define the burst count bytes upper limit
1353 CONFIG_TPM_ATMEL_TWI
1354 Support for Atmel TWI TPM device. Requires I2C support.
1357 Support for generic parallel port TPM devices. Only one device
1358 per system is supported at this time.
1360 CONFIG_TPM_TIS_BASE_ADDRESS
1361 Base address where the generic TPM device is mapped
1362 to. Contemporary x86 systems usually map it at
1366 Add tpm monitor functions.
1367 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1368 provides monitor access to authorized functions.
1371 Define this to enable the TPM support library which provides
1372 functional interfaces to some TPM commands.
1373 Requires support for a TPM device.
1375 CONFIG_TPM_AUTH_SESSIONS
1376 Define this to enable authorized functions in the TPM library.
1377 Requires CONFIG_TPM and CONFIG_SHA1.
1380 At the moment only the UHCI host controller is
1381 supported (PIP405, MIP405, MPC5200); define
1382 CONFIG_USB_UHCI to enable it.
1383 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1384 and define CONFIG_USB_STORAGE to enable the USB
1387 Supported are USB Keyboards and USB Floppy drives
1389 MPC5200 USB requires additional defines:
1391 for 528 MHz Clock: 0x0001bbbb
1395 for differential drivers: 0x00001000
1396 for single ended drivers: 0x00005000
1397 for differential drivers on PSC3: 0x00000100
1398 for single ended drivers on PSC3: 0x00004100
1399 CONFIG_SYS_USB_EVENT_POLL
1400 May be defined to allow interrupt polling
1401 instead of using asynchronous interrupts
1403 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1404 txfilltuning field in the EHCI controller on reset.
1406 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1407 interval for usb hub power-on delay.(minimum 100msec)
1410 Define the below if you wish to use the USB console.
1411 Once firmware is rebuilt from a serial console issue the
1412 command "setenv stdin usbtty; setenv stdout usbtty" and
1413 attach your USB cable. The Unix command "dmesg" should print
1414 it has found a new device. The environment variable usbtty
1415 can be set to gserial or cdc_acm to enable your device to
1416 appear to a USB host as a Linux gserial device or a
1417 Common Device Class Abstract Control Model serial device.
1418 If you select usbtty = gserial you should be able to enumerate
1420 # modprobe usbserial vendor=0xVendorID product=0xProductID
1421 else if using cdc_acm, simply setting the environment
1422 variable usbtty to be cdc_acm should suffice. The following
1423 might be defined in YourBoardName.h
1426 Define this to build a UDC device
1429 Define this to have a tty type of device available to
1430 talk to the UDC device
1433 Define this to enable the high speed support for usb
1434 device and usbtty. If this feature is enabled, a routine
1435 int is_usbd_high_speed(void)
1436 also needs to be defined by the driver to dynamically poll
1437 whether the enumeration has succeded at high speed or full
1440 CONFIG_SYS_CONSOLE_IS_IN_ENV
1441 Define this if you want stdin, stdout &/or stderr to
1445 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1446 Derive USB clock from external clock "blah"
1447 - CONFIG_SYS_USB_EXTC_CLK 0x02
1449 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1450 Derive USB clock from brgclk
1451 - CONFIG_SYS_USB_BRG_CLK 0x04
1453 If you have a USB-IF assigned VendorID then you may wish to
1454 define your own vendor specific values either in BoardName.h
1455 or directly in usbd_vendor_info.h. If you don't define
1456 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1457 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1458 should pretend to be a Linux device to it's target host.
1460 CONFIG_USBD_MANUFACTURER
1461 Define this string as the name of your company for
1462 - CONFIG_USBD_MANUFACTURER "my company"
1464 CONFIG_USBD_PRODUCT_NAME
1465 Define this string as the name of your product
1466 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1468 CONFIG_USBD_VENDORID
1469 Define this as your assigned Vendor ID from the USB
1470 Implementors Forum. This *must* be a genuine Vendor ID
1471 to avoid polluting the USB namespace.
1472 - CONFIG_USBD_VENDORID 0xFFFF
1474 CONFIG_USBD_PRODUCTID
1475 Define this as the unique Product ID
1477 - CONFIG_USBD_PRODUCTID 0xFFFF
1479 Some USB device drivers may need to check USB cable attachment.
1480 In this case you can enable following config in BoardName.h:
1481 CONFIG_USB_CABLE_CHECK
1482 This enables function definition:
1483 - usb_cable_connected() in include/usb.h
1484 Implementation of this function is board-specific.
1486 - ULPI Layer Support:
1487 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1488 the generic ULPI layer. The generic layer accesses the ULPI PHY
1489 via the platform viewport, so you need both the genric layer and
1490 the viewport enabled. Currently only Chipidea/ARC based
1491 viewport is supported.
1492 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1493 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1494 If your ULPI phy needs a different reference clock than the
1495 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1496 the appropriate value in Hz.
1499 The MMC controller on the Intel PXA is supported. To
1500 enable this define CONFIG_MMC. The MMC can be
1501 accessed from the boot prompt by mapping the device
1502 to physical memory similar to flash. Command line is
1503 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1504 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1507 Support for Renesas on-chip MMCIF controller
1509 CONFIG_SH_MMCIF_ADDR
1510 Define the base address of MMCIF registers
1513 Define the clock frequency for MMCIF
1515 - USB Device Firmware Update (DFU) class support:
1517 This enables the USB portion of the DFU USB class
1520 This enables the command "dfu" which is used to have
1521 U-Boot create a DFU class device via USB. This command
1522 requires that the "dfu_alt_info" environment variable be
1523 set and define the alt settings to expose to the host.
1526 This enables support for exposing (e)MMC devices via DFU.
1529 This enables support for exposing NAND devices via DFU.
1532 This enables support for exposing RAM via DFU.
1533 Note: DFU spec refer to non-volatile memory usage, but
1534 allow usages beyond the scope of spec - here RAM usage,
1535 one that would help mostly the developer.
1537 CONFIG_SYS_DFU_DATA_BUF_SIZE
1538 Dfu transfer uses a buffer before writing data to the
1539 raw storage device. Make the size (in bytes) of this buffer
1540 configurable. The size of this buffer is also configurable
1541 through the "dfu_bufsiz" environment variable.
1543 CONFIG_SYS_DFU_MAX_FILE_SIZE
1544 When updating files rather than the raw storage device,
1545 we use a static buffer to copy the file into and then write
1546 the buffer once we've been given the whole file. Define
1547 this to the maximum filesize (in bytes) for the buffer.
1548 Default is 4 MiB if undefined.
1550 DFU_DEFAULT_POLL_TIMEOUT
1551 Poll timeout [ms], is the timeout a device can send to the
1552 host. The host must wait for this timeout before sending
1553 a subsequent DFU_GET_STATUS request to the device.
1555 DFU_MANIFEST_POLL_TIMEOUT
1556 Poll timeout [ms], which the device sends to the host when
1557 entering dfuMANIFEST state. Host waits this timeout, before
1558 sending again an USB request to the device.
1560 - Journaling Flash filesystem support:
1561 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1562 CONFIG_JFFS2_NAND_DEV
1563 Define these for a default partition on a NAND device
1565 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1566 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1567 Define these for a default partition on a NOR device
1569 CONFIG_SYS_JFFS_CUSTOM_PART
1570 Define this to create an own partition. You have to provide a
1571 function struct part_info* jffs2_part_info(int part_num)
1573 If you define only one JFFS2 partition you may also want to
1574 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1575 to disable the command chpart. This is the default when you
1576 have not defined a custom partition
1578 - FAT(File Allocation Table) filesystem write function support:
1581 Define this to enable support for saving memory data as a
1582 file in FAT formatted partition.
1584 This will also enable the command "fatwrite" enabling the
1585 user to write files to FAT.
1587 CBFS (Coreboot Filesystem) support
1590 Define this to enable support for reading from a Coreboot
1591 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1597 Define this to enable standard (PC-Style) keyboard
1601 Standard PC keyboard driver with US (is default) and
1602 GERMAN key layout (switch via environment 'keymap=de') support.
1603 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1604 for cfb_console. Supports cursor blinking.
1607 Enables a Chrome OS keyboard using the CROS_EC interface.
1608 This uses CROS_EC to communicate with a second microcontroller
1609 which provides key scans on request.
1614 Define this to enable video support (for output to
1617 CONFIG_VIDEO_CT69000
1619 Enable Chips & Technologies 69000 Video chip
1621 CONFIG_VIDEO_SMI_LYNXEM
1622 Enable Silicon Motion SMI 712/710/810 Video chip. The
1623 video output is selected via environment 'videoout'
1624 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1627 For the CT69000 and SMI_LYNXEM drivers, videomode is
1628 selected via environment 'videomode'. Two different ways
1630 - "videomode=num" 'num' is a standard LiLo mode numbers.
1631 Following standard modes are supported (* is default):
1633 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1634 -------------+---------------------------------------------
1635 8 bits | 0x301* 0x303 0x305 0x161 0x307
1636 15 bits | 0x310 0x313 0x316 0x162 0x319
1637 16 bits | 0x311 0x314 0x317 0x163 0x31A
1638 24 bits | 0x312 0x315 0x318 ? 0x31B
1639 -------------+---------------------------------------------
1640 (i.e. setenv videomode 317; saveenv; reset;)
1642 - "videomode=bootargs" all the video parameters are parsed
1643 from the bootargs. (See drivers/video/videomodes.c)
1646 CONFIG_VIDEO_SED13806
1647 Enable Epson SED13806 driver. This driver supports 8bpp
1648 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1649 or CONFIG_VIDEO_SED13806_16BPP
1652 Enable the Freescale DIU video driver. Reference boards for
1653 SOCs that have a DIU should define this macro to enable DIU
1654 support, and should also define these other macros:
1660 CONFIG_VIDEO_SW_CURSOR
1661 CONFIG_VGA_AS_SINGLE_DEVICE
1663 CONFIG_VIDEO_BMP_LOGO
1665 The DIU driver will look for the 'video-mode' environment
1666 variable, and if defined, enable the DIU as a console during
1667 boot. See the documentation file README.video for a
1668 description of this variable.
1672 Enable the VGA video / BIOS for x86. The alternative if you
1673 are using coreboot is to use the coreboot frame buffer
1680 Define this to enable a custom keyboard support.
1681 This simply calls drv_keyboard_init() which must be
1682 defined in your board-specific files.
1683 The only board using this so far is RBC823.
1685 - LCD Support: CONFIG_LCD
1687 Define this to enable LCD support (for output to LCD
1688 display); also select one of the supported displays
1689 by defining one of these:
1693 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1695 CONFIG_NEC_NL6448AC33:
1697 NEC NL6448AC33-18. Active, color, single scan.
1699 CONFIG_NEC_NL6448BC20
1701 NEC NL6448BC20-08. 6.5", 640x480.
1702 Active, color, single scan.
1704 CONFIG_NEC_NL6448BC33_54
1706 NEC NL6448BC33-54. 10.4", 640x480.
1707 Active, color, single scan.
1711 Sharp 320x240. Active, color, single scan.
1712 It isn't 16x9, and I am not sure what it is.
1714 CONFIG_SHARP_LQ64D341
1716 Sharp LQ64D341 display, 640x480.
1717 Active, color, single scan.
1721 HLD1045 display, 640x480.
1722 Active, color, single scan.
1726 Optrex CBL50840-2 NF-FW 99 22 M5
1728 Hitachi LMG6912RPFC-00T
1732 320x240. Black & white.
1734 Normally display is black on white background; define
1735 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1737 CONFIG_LCD_ALIGNMENT
1739 Normally the LCD is page-aligned (tyically 4KB). If this is
1740 defined then the LCD will be aligned to this value instead.
1741 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1742 here, since it is cheaper to change data cache settings on
1743 a per-section basis.
1745 CONFIG_CONSOLE_SCROLL_LINES
1747 When the console need to be scrolled, this is the number of
1748 lines to scroll by. It defaults to 1. Increasing this makes
1749 the console jump but can help speed up operation when scrolling
1754 Support drawing of RLE8-compressed bitmaps on the LCD.
1758 Enables an 'i2c edid' command which can read EDID
1759 information over I2C from an attached LCD display.
1761 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1763 If this option is set, the environment is checked for
1764 a variable "splashimage". If found, the usual display
1765 of logo, copyright and system information on the LCD
1766 is suppressed and the BMP image at the address
1767 specified in "splashimage" is loaded instead. The
1768 console is redirected to the "nulldev", too. This
1769 allows for a "silent" boot where a splash screen is
1770 loaded very quickly after power-on.
1772 CONFIG_SPLASHIMAGE_GUARD
1774 If this option is set, then U-Boot will prevent the environment
1775 variable "splashimage" from being set to a problematic address
1776 (see README.displaying-bmps).
1777 This option is useful for targets where, due to alignment
1778 restrictions, an improperly aligned BMP image will cause a data
1779 abort. If you think you will not have problems with unaligned
1780 accesses (for example because your toolchain prevents them)
1781 there is no need to set this option.
1783 CONFIG_SPLASH_SCREEN_ALIGN
1785 If this option is set the splash image can be freely positioned
1786 on the screen. Environment variable "splashpos" specifies the
1787 position as "x,y". If a positive number is given it is used as
1788 number of pixel from left/top. If a negative number is given it
1789 is used as number of pixel from right/bottom. You can also
1790 specify 'm' for centering the image.
1793 setenv splashpos m,m
1794 => image at center of screen
1796 setenv splashpos 30,20
1797 => image at x = 30 and y = 20
1799 setenv splashpos -10,m
1800 => vertically centered image
1801 at x = dspWidth - bmpWidth - 9
1803 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1805 If this option is set, additionally to standard BMP
1806 images, gzipped BMP images can be displayed via the
1807 splashscreen support or the bmp command.
1809 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1811 If this option is set, 8-bit RLE compressed BMP images
1812 can be displayed via the splashscreen support or the
1815 - Do compresssing for memory range:
1818 If this option is set, it would use zlib deflate method
1819 to compress the specified memory at its best effort.
1821 - Compression support:
1824 Enabled by default to support gzip compressed images.
1828 If this option is set, support for bzip2 compressed
1829 images is included. If not, only uncompressed and gzip
1830 compressed images are supported.
1832 NOTE: the bzip2 algorithm requires a lot of RAM, so
1833 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1838 If this option is set, support for lzma compressed
1841 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1842 requires an amount of dynamic memory that is given by the
1845 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1847 Where lc and lp stand for, respectively, Literal context bits
1848 and Literal pos bits.
1850 This value is upper-bounded by 14MB in the worst case. Anyway,
1851 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1852 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1853 a very small buffer.
1855 Use the lzmainfo tool to determinate the lc and lp values and
1856 then calculate the amount of needed dynamic memory (ensuring
1857 the appropriate CONFIG_SYS_MALLOC_LEN value).
1861 If this option is set, support for LZO compressed images
1867 The address of PHY on MII bus.
1869 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1871 The clock frequency of the MII bus
1875 If this option is set, support for speed/duplex
1876 detection of gigabit PHY is included.
1878 CONFIG_PHY_RESET_DELAY
1880 Some PHY like Intel LXT971A need extra delay after
1881 reset before any MII register access is possible.
1882 For such PHY, set this option to the usec delay
1883 required. (minimum 300usec for LXT971A)
1885 CONFIG_PHY_CMD_DELAY (ppc4xx)
1887 Some PHY like Intel LXT971A need extra delay after
1888 command issued before MII status register can be read
1898 Define a default value for Ethernet address to use
1899 for the respective Ethernet interface, in case this
1900 is not determined automatically.
1905 Define a default value for the IP address to use for
1906 the default Ethernet interface, in case this is not
1907 determined through e.g. bootp.
1908 (Environment variable "ipaddr")
1910 - Server IP address:
1913 Defines a default value for the IP address of a TFTP
1914 server to contact when using the "tftboot" command.
1915 (Environment variable "serverip")
1917 CONFIG_KEEP_SERVERADDR
1919 Keeps the server's MAC address, in the env 'serveraddr'
1920 for passing to bootargs (like Linux's netconsole option)
1922 - Gateway IP address:
1925 Defines a default value for the IP address of the
1926 default router where packets to other networks are
1928 (Environment variable "gatewayip")
1933 Defines a default value for the subnet mask (or
1934 routing prefix) which is used to determine if an IP
1935 address belongs to the local subnet or needs to be
1936 forwarded through a router.
1937 (Environment variable "netmask")
1939 - Multicast TFTP Mode:
1942 Defines whether you want to support multicast TFTP as per
1943 rfc-2090; for example to work with atftp. Lets lots of targets
1944 tftp down the same boot image concurrently. Note: the Ethernet
1945 driver in use must provide a function: mcast() to join/leave a
1948 - BOOTP Recovery Mode:
1949 CONFIG_BOOTP_RANDOM_DELAY
1951 If you have many targets in a network that try to
1952 boot using BOOTP, you may want to avoid that all
1953 systems send out BOOTP requests at precisely the same
1954 moment (which would happen for instance at recovery
1955 from a power failure, when all systems will try to
1956 boot, thus flooding the BOOTP server. Defining
1957 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1958 inserted before sending out BOOTP requests. The
1959 following delays are inserted then:
1961 1st BOOTP request: delay 0 ... 1 sec
1962 2nd BOOTP request: delay 0 ... 2 sec
1963 3rd BOOTP request: delay 0 ... 4 sec
1965 BOOTP requests: delay 0 ... 8 sec
1967 - DHCP Advanced Options:
1968 You can fine tune the DHCP functionality by defining
1969 CONFIG_BOOTP_* symbols:
1971 CONFIG_BOOTP_SUBNETMASK
1972 CONFIG_BOOTP_GATEWAY
1973 CONFIG_BOOTP_HOSTNAME
1974 CONFIG_BOOTP_NISDOMAIN
1975 CONFIG_BOOTP_BOOTPATH
1976 CONFIG_BOOTP_BOOTFILESIZE
1979 CONFIG_BOOTP_SEND_HOSTNAME
1980 CONFIG_BOOTP_NTPSERVER
1981 CONFIG_BOOTP_TIMEOFFSET
1982 CONFIG_BOOTP_VENDOREX
1983 CONFIG_BOOTP_MAY_FAIL
1985 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1986 environment variable, not the BOOTP server.
1988 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1989 after the configured retry count, the call will fail
1990 instead of starting over. This can be used to fail over
1991 to Link-local IP address configuration if the DHCP server
1994 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1995 serverip from a DHCP server, it is possible that more
1996 than one DNS serverip is offered to the client.
1997 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1998 serverip will be stored in the additional environment
1999 variable "dnsip2". The first DNS serverip is always
2000 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
2003 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
2004 to do a dynamic update of a DNS server. To do this, they
2005 need the hostname of the DHCP requester.
2006 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
2007 of the "hostname" environment variable is passed as
2008 option 12 to the DHCP server.
2010 CONFIG_BOOTP_DHCP_REQUEST_DELAY
2012 A 32bit value in microseconds for a delay between
2013 receiving a "DHCP Offer" and sending the "DHCP Request".
2014 This fixes a problem with certain DHCP servers that don't
2015 respond 100% of the time to a "DHCP request". E.g. On an
2016 AT91RM9200 processor running at 180MHz, this delay needed
2017 to be *at least* 15,000 usec before a Windows Server 2003
2018 DHCP server would reply 100% of the time. I recommend at
2019 least 50,000 usec to be safe. The alternative is to hope
2020 that one of the retries will be successful but note that
2021 the DHCP timeout and retry process takes a longer than
2024 - Link-local IP address negotiation:
2025 Negotiate with other link-local clients on the local network
2026 for an address that doesn't require explicit configuration.
2027 This is especially useful if a DHCP server cannot be guaranteed
2028 to exist in all environments that the device must operate.
2030 See doc/README.link-local for more information.
2033 CONFIG_CDP_DEVICE_ID
2035 The device id used in CDP trigger frames.
2037 CONFIG_CDP_DEVICE_ID_PREFIX
2039 A two character string which is prefixed to the MAC address
2044 A printf format string which contains the ascii name of
2045 the port. Normally is set to "eth%d" which sets
2046 eth0 for the first Ethernet, eth1 for the second etc.
2048 CONFIG_CDP_CAPABILITIES
2050 A 32bit integer which indicates the device capabilities;
2051 0x00000010 for a normal host which does not forwards.
2055 An ascii string containing the version of the software.
2059 An ascii string containing the name of the platform.
2063 A 32bit integer sent on the trigger.
2065 CONFIG_CDP_POWER_CONSUMPTION
2067 A 16bit integer containing the power consumption of the
2068 device in .1 of milliwatts.
2070 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2072 A byte containing the id of the VLAN.
2074 - Status LED: CONFIG_STATUS_LED
2076 Several configurations allow to display the current
2077 status using a LED. For instance, the LED will blink
2078 fast while running U-Boot code, stop blinking as
2079 soon as a reply to a BOOTP request was received, and
2080 start blinking slow once the Linux kernel is running
2081 (supported by a status LED driver in the Linux
2082 kernel). Defining CONFIG_STATUS_LED enables this
2088 The status LED can be connected to a GPIO pin.
2089 In such cases, the gpio_led driver can be used as a
2090 status LED backend implementation. Define CONFIG_GPIO_LED
2091 to include the gpio_led driver in the U-Boot binary.
2093 CONFIG_GPIO_LED_INVERTED_TABLE
2094 Some GPIO connected LEDs may have inverted polarity in which
2095 case the GPIO high value corresponds to LED off state and
2096 GPIO low value corresponds to LED on state.
2097 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2098 with a list of GPIO LEDs that have inverted polarity.
2100 - CAN Support: CONFIG_CAN_DRIVER
2102 Defining CONFIG_CAN_DRIVER enables CAN driver support
2103 on those systems that support this (optional)
2104 feature, like the TQM8xxL modules.
2106 - I2C Support: CONFIG_SYS_I2C
2108 This enable the NEW i2c subsystem, and will allow you to use
2109 i2c commands at the u-boot command line (as long as you set
2110 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2111 based realtime clock chips or other i2c devices. See
2112 common/cmd_i2c.c for a description of the command line
2115 ported i2c driver to the new framework:
2116 - drivers/i2c/soft_i2c.c:
2117 - activate first bus with CONFIG_SYS_I2C_SOFT define
2118 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2119 for defining speed and slave address
2120 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2121 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2122 for defining speed and slave address
2123 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2124 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2125 for defining speed and slave address
2126 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2127 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2128 for defining speed and slave address
2130 - drivers/i2c/fsl_i2c.c:
2131 - activate i2c driver with CONFIG_SYS_I2C_FSL
2132 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2133 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2134 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2136 - If your board supports a second fsl i2c bus, define
2137 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2138 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2139 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2142 - drivers/i2c/tegra_i2c.c:
2143 - activate this driver with CONFIG_SYS_I2C_TEGRA
2144 - This driver adds 4 i2c buses with a fix speed from
2145 100000 and the slave addr 0!
2147 - drivers/i2c/ppc4xx_i2c.c
2148 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2149 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2150 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2152 - drivers/i2c/i2c_mxc.c
2153 - activate this driver with CONFIG_SYS_I2C_MXC
2154 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2155 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2156 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2157 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2158 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2159 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2160 If thoses defines are not set, default value is 100000
2161 for speed, and 0 for slave.
2163 - drivers/i2c/rcar_i2c.c:
2164 - activate this driver with CONFIG_SYS_I2C_RCAR
2165 - This driver adds 4 i2c buses
2167 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2168 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2169 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2170 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2171 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2172 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2173 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2174 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2175 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2177 - drivers/i2c/sh_i2c.c:
2178 - activate this driver with CONFIG_SYS_I2C_SH
2179 - This driver adds from 2 to 5 i2c buses
2181 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2182 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2183 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2184 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2185 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2186 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2187 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2188 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2189 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2190 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2191 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2192 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2193 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2195 - drivers/i2c/omap24xx_i2c.c
2196 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2197 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2198 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2199 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2200 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2201 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2202 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2203 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2204 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2205 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2206 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2208 - drivers/i2c/zynq_i2c.c
2209 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2210 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2211 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2213 - drivers/i2c/s3c24x0_i2c.c:
2214 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2215 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2216 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2217 with a fix speed from 100000 and the slave addr 0!
2221 CONFIG_SYS_NUM_I2C_BUSES
2222 Hold the number of i2c busses you want to use. If you
2223 don't use/have i2c muxes on your i2c bus, this
2224 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2227 CONFIG_SYS_I2C_DIRECT_BUS
2228 define this, if you don't use i2c muxes on your hardware.
2229 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2232 CONFIG_SYS_I2C_MAX_HOPS
2233 define how many muxes are maximal consecutively connected
2234 on one i2c bus. If you not use i2c muxes, omit this
2237 CONFIG_SYS_I2C_BUSES
2238 hold a list of busses you want to use, only used if
2239 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2240 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2241 CONFIG_SYS_NUM_I2C_BUSES = 9:
2243 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2244 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2245 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2246 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2247 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2248 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2249 {1, {I2C_NULL_HOP}}, \
2250 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2251 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2255 bus 0 on adapter 0 without a mux
2256 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2257 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2258 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2259 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2260 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2261 bus 6 on adapter 1 without a mux
2262 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2263 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2265 If you do not have i2c muxes on your board, omit this define.
2267 - Legacy I2C Support: CONFIG_HARD_I2C
2269 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2270 provides the following compelling advantages:
2272 - more than one i2c adapter is usable
2273 - approved multibus support
2274 - better i2c mux support
2276 ** Please consider updating your I2C driver now. **
2278 These enable legacy I2C serial bus commands. Defining
2279 CONFIG_HARD_I2C will include the appropriate I2C driver
2280 for the selected CPU.
2282 This will allow you to use i2c commands at the u-boot
2283 command line (as long as you set CONFIG_CMD_I2C in
2284 CONFIG_COMMANDS) and communicate with i2c based realtime
2285 clock chips. See common/cmd_i2c.c for a description of the
2286 command line interface.
2288 CONFIG_HARD_I2C selects a hardware I2C controller.
2290 There are several other quantities that must also be
2291 defined when you define CONFIG_HARD_I2C.
2293 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2294 to be the frequency (in Hz) at which you wish your i2c bus
2295 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2296 the CPU's i2c node address).
2298 Now, the u-boot i2c code for the mpc8xx
2299 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2300 and so its address should therefore be cleared to 0 (See,
2301 eg, MPC823e User's Manual p.16-473). So, set
2302 CONFIG_SYS_I2C_SLAVE to 0.
2304 CONFIG_SYS_I2C_INIT_MPC5XXX
2306 When a board is reset during an i2c bus transfer
2307 chips might think that the current transfer is still
2308 in progress. Reset the slave devices by sending start
2309 commands until the slave device responds.
2311 That's all that's required for CONFIG_HARD_I2C.
2313 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2314 then the following macros need to be defined (examples are
2315 from include/configs/lwmon.h):
2319 (Optional). Any commands necessary to enable the I2C
2320 controller or configure ports.
2322 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2326 (Only for MPC8260 CPU). The I/O port to use (the code
2327 assumes both bits are on the same port). Valid values
2328 are 0..3 for ports A..D.
2332 The code necessary to make the I2C data line active
2333 (driven). If the data line is open collector, this
2336 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2340 The code necessary to make the I2C data line tri-stated
2341 (inactive). If the data line is open collector, this
2344 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2348 Code that returns true if the I2C data line is high,
2351 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2355 If <bit> is true, sets the I2C data line high. If it
2356 is false, it clears it (low).
2358 eg: #define I2C_SDA(bit) \
2359 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2360 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2364 If <bit> is true, sets the I2C clock line high. If it
2365 is false, it clears it (low).
2367 eg: #define I2C_SCL(bit) \
2368 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2369 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2373 This delay is invoked four times per clock cycle so this
2374 controls the rate of data transfer. The data rate thus
2375 is 1 / (I2C_DELAY * 4). Often defined to be something
2378 #define I2C_DELAY udelay(2)
2380 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2382 If your arch supports the generic GPIO framework (asm/gpio.h),
2383 then you may alternatively define the two GPIOs that are to be
2384 used as SCL / SDA. Any of the previous I2C_xxx macros will
2385 have GPIO-based defaults assigned to them as appropriate.
2387 You should define these to the GPIO value as given directly to
2388 the generic GPIO functions.
2390 CONFIG_SYS_I2C_INIT_BOARD
2392 When a board is reset during an i2c bus transfer
2393 chips might think that the current transfer is still
2394 in progress. On some boards it is possible to access
2395 the i2c SCLK line directly, either by using the
2396 processor pin as a GPIO or by having a second pin
2397 connected to the bus. If this option is defined a
2398 custom i2c_init_board() routine in boards/xxx/board.c
2399 is run early in the boot sequence.
2401 CONFIG_SYS_I2C_BOARD_LATE_INIT
2403 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2404 defined a custom i2c_board_late_init() routine in
2405 boards/xxx/board.c is run AFTER the operations in i2c_init()
2406 is completed. This callpoint can be used to unreset i2c bus
2407 using CPU i2c controller register accesses for CPUs whose i2c
2408 controller provide such a method. It is called at the end of
2409 i2c_init() to allow i2c_init operations to setup the i2c bus
2410 controller on the CPU (e.g. setting bus speed & slave address).
2412 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2414 This option enables configuration of bi_iic_fast[] flags
2415 in u-boot bd_info structure based on u-boot environment
2416 variable "i2cfast". (see also i2cfast)
2418 CONFIG_I2C_MULTI_BUS
2420 This option allows the use of multiple I2C buses, each of which
2421 must have a controller. At any point in time, only one bus is
2422 active. To switch to a different bus, use the 'i2c dev' command.
2423 Note that bus numbering is zero-based.
2425 CONFIG_SYS_I2C_NOPROBES
2427 This option specifies a list of I2C devices that will be skipped
2428 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2429 is set, specify a list of bus-device pairs. Otherwise, specify
2430 a 1D array of device addresses
2433 #undef CONFIG_I2C_MULTI_BUS
2434 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2436 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2438 #define CONFIG_I2C_MULTI_BUS
2439 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2441 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2443 CONFIG_SYS_SPD_BUS_NUM
2445 If defined, then this indicates the I2C bus number for DDR SPD.
2446 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2448 CONFIG_SYS_RTC_BUS_NUM
2450 If defined, then this indicates the I2C bus number for the RTC.
2451 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2453 CONFIG_SYS_DTT_BUS_NUM
2455 If defined, then this indicates the I2C bus number for the DTT.
2456 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2458 CONFIG_SYS_I2C_DTT_ADDR:
2460 If defined, specifies the I2C address of the DTT device.
2461 If not defined, then U-Boot uses predefined value for
2462 specified DTT device.
2464 CONFIG_SOFT_I2C_READ_REPEATED_START
2466 defining this will force the i2c_read() function in
2467 the soft_i2c driver to perform an I2C repeated start
2468 between writing the address pointer and reading the
2469 data. If this define is omitted the default behaviour
2470 of doing a stop-start sequence will be used. Most I2C
2471 devices can use either method, but some require one or
2474 - SPI Support: CONFIG_SPI
2476 Enables SPI driver (so far only tested with
2477 SPI EEPROM, also an instance works with Crystal A/D and
2478 D/As on the SACSng board)
2482 Enables the driver for SPI controller on SuperH. Currently
2483 only SH7757 is supported.
2487 Enables extended (16-bit) SPI EEPROM addressing.
2488 (symmetrical to CONFIG_I2C_X)
2492 Enables a software (bit-bang) SPI driver rather than
2493 using hardware support. This is a general purpose
2494 driver that only requires three general I/O port pins
2495 (two outputs, one input) to function. If this is
2496 defined, the board configuration must define several
2497 SPI configuration items (port pins to use, etc). For
2498 an example, see include/configs/sacsng.h.
2502 Enables a hardware SPI driver for general-purpose reads
2503 and writes. As with CONFIG_SOFT_SPI, the board configuration
2504 must define a list of chip-select function pointers.
2505 Currently supported on some MPC8xxx processors. For an
2506 example, see include/configs/mpc8349emds.h.
2510 Enables the driver for the SPI controllers on i.MX and MXC
2511 SoCs. Currently i.MX31/35/51 are supported.
2513 - FPGA Support: CONFIG_FPGA
2515 Enables FPGA subsystem.
2517 CONFIG_FPGA_<vendor>
2519 Enables support for specific chip vendors.
2522 CONFIG_FPGA_<family>
2524 Enables support for FPGA family.
2525 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2529 Specify the number of FPGA devices to support.
2531 CONFIG_SYS_FPGA_PROG_FEEDBACK
2533 Enable printing of hash marks during FPGA configuration.
2535 CONFIG_SYS_FPGA_CHECK_BUSY
2537 Enable checks on FPGA configuration interface busy
2538 status by the configuration function. This option
2539 will require a board or device specific function to
2544 If defined, a function that provides delays in the FPGA
2545 configuration driver.
2547 CONFIG_SYS_FPGA_CHECK_CTRLC
2548 Allow Control-C to interrupt FPGA configuration
2550 CONFIG_SYS_FPGA_CHECK_ERROR
2552 Check for configuration errors during FPGA bitfile
2553 loading. For example, abort during Virtex II
2554 configuration if the INIT_B line goes low (which
2555 indicated a CRC error).
2557 CONFIG_SYS_FPGA_WAIT_INIT
2559 Maximum time to wait for the INIT_B line to deassert
2560 after PROB_B has been deasserted during a Virtex II
2561 FPGA configuration sequence. The default time is 500
2564 CONFIG_SYS_FPGA_WAIT_BUSY
2566 Maximum time to wait for BUSY to deassert during
2567 Virtex II FPGA configuration. The default is 5 ms.
2569 CONFIG_SYS_FPGA_WAIT_CONFIG
2571 Time to wait after FPGA configuration. The default is
2574 - Configuration Management:
2577 If defined, this string will be added to the U-Boot
2578 version information (U_BOOT_VERSION)
2580 - Vendor Parameter Protection:
2582 U-Boot considers the values of the environment
2583 variables "serial#" (Board Serial Number) and
2584 "ethaddr" (Ethernet Address) to be parameters that
2585 are set once by the board vendor / manufacturer, and
2586 protects these variables from casual modification by
2587 the user. Once set, these variables are read-only,
2588 and write or delete attempts are rejected. You can
2589 change this behaviour:
2591 If CONFIG_ENV_OVERWRITE is #defined in your config
2592 file, the write protection for vendor parameters is
2593 completely disabled. Anybody can change or delete
2596 Alternatively, if you #define _both_ CONFIG_ETHADDR
2597 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2598 Ethernet address is installed in the environment,
2599 which can be changed exactly ONCE by the user. [The
2600 serial# is unaffected by this, i. e. it remains
2603 The same can be accomplished in a more flexible way
2604 for any variable by configuring the type of access
2605 to allow for those variables in the ".flags" variable
2606 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2611 Define this variable to enable the reservation of
2612 "protected RAM", i. e. RAM which is not overwritten
2613 by U-Boot. Define CONFIG_PRAM to hold the number of
2614 kB you want to reserve for pRAM. You can overwrite
2615 this default value by defining an environment
2616 variable "pram" to the number of kB you want to
2617 reserve. Note that the board info structure will
2618 still show the full amount of RAM. If pRAM is
2619 reserved, a new environment variable "mem" will
2620 automatically be defined to hold the amount of
2621 remaining RAM in a form that can be passed as boot
2622 argument to Linux, for instance like that:
2624 setenv bootargs ... mem=\${mem}
2627 This way you can tell Linux not to use this memory,
2628 either, which results in a memory region that will
2629 not be affected by reboots.
2631 *WARNING* If your board configuration uses automatic
2632 detection of the RAM size, you must make sure that
2633 this memory test is non-destructive. So far, the
2634 following board configurations are known to be
2637 IVMS8, IVML24, SPD8xx, TQM8xxL,
2638 HERMES, IP860, RPXlite, LWMON,
2641 - Access to physical memory region (> 4GB)
2642 Some basic support is provided for operations on memory not
2643 normally accessible to U-Boot - e.g. some architectures
2644 support access to more than 4GB of memory on 32-bit
2645 machines using physical address extension or similar.
2646 Define CONFIG_PHYSMEM to access this basic support, which
2647 currently only supports clearing the memory.
2652 Define this variable to stop the system in case of a
2653 fatal error, so that you have to reset it manually.
2654 This is probably NOT a good idea for an embedded
2655 system where you want the system to reboot
2656 automatically as fast as possible, but it may be
2657 useful during development since you can try to debug
2658 the conditions that lead to the situation.
2660 CONFIG_NET_RETRY_COUNT
2662 This variable defines the number of retries for
2663 network operations like ARP, RARP, TFTP, or BOOTP
2664 before giving up the operation. If not defined, a
2665 default value of 5 is used.
2669 Timeout waiting for an ARP reply in milliseconds.
2673 Timeout in milliseconds used in NFS protocol.
2674 If you encounter "ERROR: Cannot umount" in nfs command,
2675 try longer timeout such as
2676 #define CONFIG_NFS_TIMEOUT 10000UL
2678 - Command Interpreter:
2679 CONFIG_AUTO_COMPLETE
2681 Enable auto completion of commands using TAB.
2683 Note that this feature has NOT been implemented yet
2684 for the "hush" shell.
2687 CONFIG_SYS_HUSH_PARSER
2689 Define this variable to enable the "hush" shell (from
2690 Busybox) as command line interpreter, thus enabling
2691 powerful command line syntax like
2692 if...then...else...fi conditionals or `&&' and '||'
2693 constructs ("shell scripts").
2695 If undefined, you get the old, much simpler behaviour
2696 with a somewhat smaller memory footprint.
2699 CONFIG_SYS_PROMPT_HUSH_PS2
2701 This defines the secondary prompt string, which is
2702 printed when the command interpreter needs more input
2703 to complete a command. Usually "> ".
2707 In the current implementation, the local variables
2708 space and global environment variables space are
2709 separated. Local variables are those you define by
2710 simply typing `name=value'. To access a local
2711 variable later on, you have write `$name' or
2712 `${name}'; to execute the contents of a variable
2713 directly type `$name' at the command prompt.
2715 Global environment variables are those you use
2716 setenv/printenv to work with. To run a command stored
2717 in such a variable, you need to use the run command,
2718 and you must not use the '$' sign to access them.
2720 To store commands and special characters in a
2721 variable, please use double quotation marks
2722 surrounding the whole text of the variable, instead
2723 of the backslashes before semicolons and special
2726 - Commandline Editing and History:
2727 CONFIG_CMDLINE_EDITING
2729 Enable editing and History functions for interactive
2730 commandline input operations
2732 - Default Environment:
2733 CONFIG_EXTRA_ENV_SETTINGS
2735 Define this to contain any number of null terminated
2736 strings (variable = value pairs) that will be part of
2737 the default environment compiled into the boot image.
2739 For example, place something like this in your
2740 board's config file:
2742 #define CONFIG_EXTRA_ENV_SETTINGS \
2746 Warning: This method is based on knowledge about the
2747 internal format how the environment is stored by the
2748 U-Boot code. This is NOT an official, exported
2749 interface! Although it is unlikely that this format
2750 will change soon, there is no guarantee either.
2751 You better know what you are doing here.
2753 Note: overly (ab)use of the default environment is
2754 discouraged. Make sure to check other ways to preset
2755 the environment like the "source" command or the
2758 CONFIG_ENV_VARS_UBOOT_CONFIG
2760 Define this in order to add variables describing the
2761 U-Boot build configuration to the default environment.
2762 These will be named arch, cpu, board, vendor, and soc.
2764 Enabling this option will cause the following to be defined:
2772 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2774 Define this in order to add variables describing certain
2775 run-time determined information about the hardware to the
2776 environment. These will be named board_name, board_rev.
2778 CONFIG_DELAY_ENVIRONMENT
2780 Normally the environment is loaded when the board is
2781 intialised so that it is available to U-Boot. This inhibits
2782 that so that the environment is not available until
2783 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2784 this is instead controlled by the value of
2785 /config/load-environment.
2787 - DataFlash Support:
2788 CONFIG_HAS_DATAFLASH
2790 Defining this option enables DataFlash features and
2791 allows to read/write in Dataflash via the standard
2794 - Serial Flash support
2797 Defining this option enables SPI flash commands
2798 'sf probe/read/write/erase/update'.
2800 Usage requires an initial 'probe' to define the serial
2801 flash parameters, followed by read/write/erase/update
2804 The following defaults may be provided by the platform
2805 to handle the common case when only a single serial
2806 flash is present on the system.
2808 CONFIG_SF_DEFAULT_BUS Bus identifier
2809 CONFIG_SF_DEFAULT_CS Chip-select
2810 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2811 CONFIG_SF_DEFAULT_SPEED in Hz
2815 Define this option to include a destructive SPI flash
2818 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2820 Define this option to use the Bank addr/Extended addr
2821 support on SPI flashes which has size > 16Mbytes.
2823 CONFIG_SF_DUAL_FLASH Dual flash memories
2825 Define this option to use dual flash support where two flash
2826 memories can be connected with a given cs line.
2827 currently Xilinx Zynq qspi support these type of connections.
2829 - SystemACE Support:
2832 Adding this option adds support for Xilinx SystemACE
2833 chips attached via some sort of local bus. The address
2834 of the chip must also be defined in the
2835 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2837 #define CONFIG_SYSTEMACE
2838 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2840 When SystemACE support is added, the "ace" device type
2841 becomes available to the fat commands, i.e. fatls.
2843 - TFTP Fixed UDP Port:
2846 If this is defined, the environment variable tftpsrcp
2847 is used to supply the TFTP UDP source port value.
2848 If tftpsrcp isn't defined, the normal pseudo-random port
2849 number generator is used.
2851 Also, the environment variable tftpdstp is used to supply
2852 the TFTP UDP destination port value. If tftpdstp isn't
2853 defined, the normal port 69 is used.
2855 The purpose for tftpsrcp is to allow a TFTP server to
2856 blindly start the TFTP transfer using the pre-configured
2857 target IP address and UDP port. This has the effect of
2858 "punching through" the (Windows XP) firewall, allowing
2859 the remainder of the TFTP transfer to proceed normally.
2860 A better solution is to properly configure the firewall,
2861 but sometimes that is not allowed.
2866 This enables a generic 'hash' command which can produce
2867 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2871 Enable the hash verify command (hash -v). This adds to code
2874 CONFIG_SHA1 - support SHA1 hashing
2875 CONFIG_SHA256 - support SHA256 hashing
2877 Note: There is also a sha1sum command, which should perhaps
2878 be deprecated in favour of 'hash sha1'.
2880 - Freescale i.MX specific commands:
2881 CONFIG_CMD_HDMIDETECT
2882 This enables 'hdmidet' command which returns true if an
2883 HDMI monitor is detected. This command is i.MX 6 specific.
2886 This enables the 'bmode' (bootmode) command for forcing
2887 a boot from specific media.
2889 This is useful for forcing the ROM's usb downloader to
2890 activate upon a watchdog reset which is nice when iterating
2891 on U-Boot. Using the reset button or running bmode normal
2892 will set it back to normal. This command currently
2893 supports i.MX53 and i.MX6.
2898 This enables the RSA algorithm used for FIT image verification
2899 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2901 The signing part is build into mkimage regardless of this
2904 - bootcount support:
2905 CONFIG_BOOTCOUNT_LIMIT
2907 This enables the bootcounter support, see:
2908 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2911 enable special bootcounter support on at91sam9xe based boards.
2913 enable special bootcounter support on blackfin based boards.
2915 enable special bootcounter support on da850 based boards.
2916 CONFIG_BOOTCOUNT_RAM
2917 enable support for the bootcounter in RAM
2918 CONFIG_BOOTCOUNT_I2C
2919 enable support for the bootcounter on an i2c (like RTC) device.
2920 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2921 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2923 CONFIG_BOOTCOUNT_ALEN = address len
2925 - Show boot progress:
2926 CONFIG_SHOW_BOOT_PROGRESS
2928 Defining this option allows to add some board-
2929 specific code (calling a user-provided function
2930 "show_boot_progress(int)") that enables you to show
2931 the system's boot progress on some display (for
2932 example, some LED's) on your board. At the moment,
2933 the following checkpoints are implemented:
2935 - Detailed boot stage timing
2937 Define this option to get detailed timing of each stage
2938 of the boot process.
2940 CONFIG_BOOTSTAGE_USER_COUNT
2941 This is the number of available user bootstage records.
2942 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2943 a new ID will be allocated from this stash. If you exceed
2944 the limit, recording will stop.
2946 CONFIG_BOOTSTAGE_REPORT
2947 Define this to print a report before boot, similar to this:
2949 Timer summary in microseconds:
2952 3,575,678 3,575,678 board_init_f start
2953 3,575,695 17 arch_cpu_init A9
2954 3,575,777 82 arch_cpu_init done
2955 3,659,598 83,821 board_init_r start
2956 3,910,375 250,777 main_loop
2957 29,916,167 26,005,792 bootm_start
2958 30,361,327 445,160 start_kernel
2960 CONFIG_CMD_BOOTSTAGE
2961 Add a 'bootstage' command which supports printing a report
2962 and un/stashing of bootstage data.
2964 CONFIG_BOOTSTAGE_FDT
2965 Stash the bootstage information in the FDT. A root 'bootstage'
2966 node is created with each bootstage id as a child. Each child
2967 has a 'name' property and either 'mark' containing the
2968 mark time in microsecond, or 'accum' containing the
2969 accumulated time for that bootstage id in microseconds.
2974 name = "board_init_f";
2983 Code in the Linux kernel can find this in /proc/devicetree.
2985 Legacy uImage format:
2988 1 common/cmd_bootm.c before attempting to boot an image
2989 -1 common/cmd_bootm.c Image header has bad magic number
2990 2 common/cmd_bootm.c Image header has correct magic number
2991 -2 common/cmd_bootm.c Image header has bad checksum
2992 3 common/cmd_bootm.c Image header has correct checksum
2993 -3 common/cmd_bootm.c Image data has bad checksum
2994 4 common/cmd_bootm.c Image data has correct checksum
2995 -4 common/cmd_bootm.c Image is for unsupported architecture
2996 5 common/cmd_bootm.c Architecture check OK
2997 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2998 6 common/cmd_bootm.c Image Type check OK
2999 -6 common/cmd_bootm.c gunzip uncompression error
3000 -7 common/cmd_bootm.c Unimplemented compression type
3001 7 common/cmd_bootm.c Uncompression OK
3002 8 common/cmd_bootm.c No uncompress/copy overwrite error
3003 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
3005 9 common/image.c Start initial ramdisk verification
3006 -10 common/image.c Ramdisk header has bad magic number
3007 -11 common/image.c Ramdisk header has bad checksum
3008 10 common/image.c Ramdisk header is OK
3009 -12 common/image.c Ramdisk data has bad checksum
3010 11 common/image.c Ramdisk data has correct checksum
3011 12 common/image.c Ramdisk verification complete, start loading
3012 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
3013 13 common/image.c Start multifile image verification
3014 14 common/image.c No initial ramdisk, no multifile, continue.
3016 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
3018 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3019 -31 post/post.c POST test failed, detected by post_output_backlog()
3020 -32 post/post.c POST test failed, detected by post_run_single()
3022 34 common/cmd_doc.c before loading a Image from a DOC device
3023 -35 common/cmd_doc.c Bad usage of "doc" command
3024 35 common/cmd_doc.c correct usage of "doc" command
3025 -36 common/cmd_doc.c No boot device
3026 36 common/cmd_doc.c correct boot device
3027 -37 common/cmd_doc.c Unknown Chip ID on boot device
3028 37 common/cmd_doc.c correct chip ID found, device available
3029 -38 common/cmd_doc.c Read Error on boot device
3030 38 common/cmd_doc.c reading Image header from DOC device OK
3031 -39 common/cmd_doc.c Image header has bad magic number
3032 39 common/cmd_doc.c Image header has correct magic number
3033 -40 common/cmd_doc.c Error reading Image from DOC device
3034 40 common/cmd_doc.c Image header has correct magic number
3035 41 common/cmd_ide.c before loading a Image from a IDE device
3036 -42 common/cmd_ide.c Bad usage of "ide" command
3037 42 common/cmd_ide.c correct usage of "ide" command
3038 -43 common/cmd_ide.c No boot device
3039 43 common/cmd_ide.c boot device found
3040 -44 common/cmd_ide.c Device not available
3041 44 common/cmd_ide.c Device available
3042 -45 common/cmd_ide.c wrong partition selected
3043 45 common/cmd_ide.c partition selected
3044 -46 common/cmd_ide.c Unknown partition table
3045 46 common/cmd_ide.c valid partition table found
3046 -47 common/cmd_ide.c Invalid partition type
3047 47 common/cmd_ide.c correct partition type
3048 -48 common/cmd_ide.c Error reading Image Header on boot device
3049 48 common/cmd_ide.c reading Image Header from IDE device OK
3050 -49 common/cmd_ide.c Image header has bad magic number
3051 49 common/cmd_ide.c Image header has correct magic number
3052 -50 common/cmd_ide.c Image header has bad checksum
3053 50 common/cmd_ide.c Image header has correct checksum
3054 -51 common/cmd_ide.c Error reading Image from IDE device
3055 51 common/cmd_ide.c reading Image from IDE device OK
3056 52 common/cmd_nand.c before loading a Image from a NAND device
3057 -53 common/cmd_nand.c Bad usage of "nand" command
3058 53 common/cmd_nand.c correct usage of "nand" command
3059 -54 common/cmd_nand.c No boot device
3060 54 common/cmd_nand.c boot device found
3061 -55 common/cmd_nand.c Unknown Chip ID on boot device
3062 55 common/cmd_nand.c correct chip ID found, device available
3063 -56 common/cmd_nand.c Error reading Image Header on boot device
3064 56 common/cmd_nand.c reading Image Header from NAND device OK
3065 -57 common/cmd_nand.c Image header has bad magic number
3066 57 common/cmd_nand.c Image header has correct magic number
3067 -58 common/cmd_nand.c Error reading Image from NAND device
3068 58 common/cmd_nand.c reading Image from NAND device OK
3070 -60 common/env_common.c Environment has a bad CRC, using default
3072 64 net/eth.c starting with Ethernet configuration.
3073 -64 net/eth.c no Ethernet found.
3074 65 net/eth.c Ethernet found.
3076 -80 common/cmd_net.c usage wrong
3077 80 common/cmd_net.c before calling NetLoop()
3078 -81 common/cmd_net.c some error in NetLoop() occurred
3079 81 common/cmd_net.c NetLoop() back without error
3080 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3081 82 common/cmd_net.c trying automatic boot
3082 83 common/cmd_net.c running "source" command
3083 -83 common/cmd_net.c some error in automatic boot or "source" command
3084 84 common/cmd_net.c end without errors
3089 100 common/cmd_bootm.c Kernel FIT Image has correct format
3090 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3091 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3092 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3093 102 common/cmd_bootm.c Kernel unit name specified
3094 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3095 103 common/cmd_bootm.c Found configuration node
3096 104 common/cmd_bootm.c Got kernel subimage node offset
3097 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3098 105 common/cmd_bootm.c Kernel subimage hash verification OK
3099 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3100 106 common/cmd_bootm.c Architecture check OK
3101 -106 common/cmd_bootm.c Kernel subimage has wrong type
3102 107 common/cmd_bootm.c Kernel subimage type OK
3103 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3104 108 common/cmd_bootm.c Got kernel subimage data/size
3105 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3106 -109 common/cmd_bootm.c Can't get kernel subimage type
3107 -110 common/cmd_bootm.c Can't get kernel subimage comp
3108 -111 common/cmd_bootm.c Can't get kernel subimage os
3109 -112 common/cmd_bootm.c Can't get kernel subimage load address
3110 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3112 120 common/image.c Start initial ramdisk verification
3113 -120 common/image.c Ramdisk FIT image has incorrect format
3114 121 common/image.c Ramdisk FIT image has correct format
3115 122 common/image.c No ramdisk subimage unit name, using configuration
3116 -122 common/image.c Can't get configuration for ramdisk subimage
3117 123 common/image.c Ramdisk unit name specified
3118 -124 common/image.c Can't get ramdisk subimage node offset
3119 125 common/image.c Got ramdisk subimage node offset
3120 -125 common/image.c Ramdisk subimage hash verification failed
3121 126 common/image.c Ramdisk subimage hash verification OK
3122 -126 common/image.c Ramdisk subimage for unsupported architecture
3123 127 common/image.c Architecture check OK
3124 -127 common/image.c Can't get ramdisk subimage data/size
3125 128 common/image.c Got ramdisk subimage data/size
3126 129 common/image.c Can't get ramdisk load address
3127 -129 common/image.c Got ramdisk load address
3129 -130 common/cmd_doc.c Incorrect FIT image format
3130 131 common/cmd_doc.c FIT image format OK
3132 -140 common/cmd_ide.c Incorrect FIT image format
3133 141 common/cmd_ide.c FIT image format OK
3135 -150 common/cmd_nand.c Incorrect FIT image format
3136 151 common/cmd_nand.c FIT image format OK
3138 - FIT image support:
3140 Enable support for the FIT uImage format.
3142 CONFIG_FIT_BEST_MATCH
3143 When no configuration is explicitly selected, default to the
3144 one whose fdt's compatibility field best matches that of
3145 U-Boot itself. A match is considered "best" if it matches the
3146 most specific compatibility entry of U-Boot's fdt's root node.
3147 The order of entries in the configuration's fdt is ignored.
3149 CONFIG_FIT_SIGNATURE
3150 This option enables signature verification of FIT uImages,
3151 using a hash signed and verified using RSA. See
3152 doc/uImage.FIT/signature.txt for more details.
3154 - Standalone program support:
3155 CONFIG_STANDALONE_LOAD_ADDR
3157 This option defines a board specific value for the
3158 address where standalone program gets loaded, thus
3159 overwriting the architecture dependent default
3162 - Frame Buffer Address:
3165 Define CONFIG_FB_ADDR if you want to use specific
3166 address for frame buffer. This is typically the case
3167 when using a graphics controller has separate video
3168 memory. U-Boot will then place the frame buffer at
3169 the given address instead of dynamically reserving it
3170 in system RAM by calling lcd_setmem(), which grabs
3171 the memory for the frame buffer depending on the
3172 configured panel size.
3174 Please see board_init_f function.
3176 - Automatic software updates via TFTP server
3178 CONFIG_UPDATE_TFTP_CNT_MAX
3179 CONFIG_UPDATE_TFTP_MSEC_MAX
3181 These options enable and control the auto-update feature;
3182 for a more detailed description refer to doc/README.update.
3184 - MTD Support (mtdparts command, UBI support)
3187 Adds the MTD device infrastructure from the Linux kernel.
3188 Needed for mtdparts command support.
3190 CONFIG_MTD_PARTITIONS
3192 Adds the MTD partitioning infrastructure from the Linux
3193 kernel. Needed for UBI support.
3198 Adds commands for interacting with MTD partitions formatted
3199 with the UBI flash translation layer
3201 Requires also defining CONFIG_RBTREE
3203 CONFIG_UBI_SILENCE_MSG
3205 Make the verbose messages from UBI stop printing. This leaves
3206 warnings and errors enabled.
3211 Adds commands for interacting with UBI volumes formatted as
3212 UBIFS. UBIFS is read-only in u-boot.
3214 Requires UBI support as well as CONFIG_LZO
3216 CONFIG_UBIFS_SILENCE_MSG
3218 Make the verbose messages from UBIFS stop printing. This leaves
3219 warnings and errors enabled.
3223 Enable building of SPL globally.
3226 LDSCRIPT for linking the SPL binary.
3228 CONFIG_SPL_MAX_FOOTPRINT
3229 Maximum size in memory allocated to the SPL, BSS included.
3230 When defined, the linker checks that the actual memory
3231 used by SPL from _start to __bss_end does not exceed it.
3232 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3233 must not be both defined at the same time.
3236 Maximum size of the SPL image (text, data, rodata, and
3237 linker lists sections), BSS excluded.
3238 When defined, the linker checks that the actual size does
3241 CONFIG_SPL_TEXT_BASE
3242 TEXT_BASE for linking the SPL binary.
3244 CONFIG_SPL_RELOC_TEXT_BASE
3245 Address to relocate to. If unspecified, this is equal to
3246 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3248 CONFIG_SPL_BSS_START_ADDR
3249 Link address for the BSS within the SPL binary.
3251 CONFIG_SPL_BSS_MAX_SIZE
3252 Maximum size in memory allocated to the SPL BSS.
3253 When defined, the linker checks that the actual memory used
3254 by SPL from __bss_start to __bss_end does not exceed it.
3255 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3256 must not be both defined at the same time.
3259 Adress of the start of the stack SPL will use
3261 CONFIG_SPL_RELOC_STACK
3262 Adress of the start of the stack SPL will use after
3263 relocation. If unspecified, this is equal to
3266 CONFIG_SYS_SPL_MALLOC_START
3267 Starting address of the malloc pool used in SPL.
3269 CONFIG_SYS_SPL_MALLOC_SIZE
3270 The size of the malloc pool used in SPL.
3272 CONFIG_SPL_FRAMEWORK
3273 Enable the SPL framework under common/. This framework
3274 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3275 NAND loading of the Linux Kernel.
3277 CONFIG_SPL_DISPLAY_PRINT
3278 For ARM, enable an optional function to print more information
3279 about the running system.
3281 CONFIG_SPL_INIT_MINIMAL
3282 Arch init code should be built for a very small image
3284 CONFIG_SPL_LIBCOMMON_SUPPORT
3285 Support for common/libcommon.o in SPL binary
3287 CONFIG_SPL_LIBDISK_SUPPORT
3288 Support for disk/libdisk.o in SPL binary
3290 CONFIG_SPL_I2C_SUPPORT
3291 Support for drivers/i2c/libi2c.o in SPL binary
3293 CONFIG_SPL_GPIO_SUPPORT
3294 Support for drivers/gpio/libgpio.o in SPL binary
3296 CONFIG_SPL_MMC_SUPPORT
3297 Support for drivers/mmc/libmmc.o in SPL binary
3299 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3300 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3301 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3302 Address, size and partition on the MMC to load U-Boot from
3303 when the MMC is being used in raw mode.
3305 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3306 Sector to load kernel uImage from when MMC is being
3307 used in raw mode (for Falcon mode)
3309 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3310 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3311 Sector and number of sectors to load kernel argument
3312 parameters from when MMC is being used in raw mode
3315 CONFIG_SPL_FAT_SUPPORT
3316 Support for fs/fat/libfat.o in SPL binary
3318 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3319 Filename to read to load U-Boot when reading from FAT
3321 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3322 Filename to read to load kernel uImage when reading
3323 from FAT (for Falcon mode)
3325 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3326 Filename to read to load kernel argument parameters
3327 when reading from FAT (for Falcon mode)
3329 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3330 Set this for NAND SPL on PPC mpc83xx targets, so that
3331 start.S waits for the rest of the SPL to load before
3332 continuing (the hardware starts execution after just
3333 loading the first page rather than the full 4K).
3335 CONFIG_SPL_SKIP_RELOCATE
3336 Avoid SPL relocation
3338 CONFIG_SPL_NAND_BASE
3339 Include nand_base.c in the SPL. Requires
3340 CONFIG_SPL_NAND_DRIVERS.
3342 CONFIG_SPL_NAND_DRIVERS
3343 SPL uses normal NAND drivers, not minimal drivers.
3346 Include standard software ECC in the SPL
3348 CONFIG_SPL_NAND_SIMPLE
3349 Support for NAND boot using simple NAND drivers that
3350 expose the cmd_ctrl() interface.
3352 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3353 Set for the SPL on PPC mpc8xxx targets, support for
3354 drivers/ddr/fsl/libddr.o in SPL binary.
3356 CONFIG_SPL_COMMON_INIT_DDR
3357 Set for common ddr init with serial presence detect in
3360 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3361 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3362 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3363 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3364 CONFIG_SYS_NAND_ECCBYTES
3365 Defines the size and behavior of the NAND that SPL uses
3368 CONFIG_SPL_NAND_BOOT
3369 Add support NAND boot
3371 CONFIG_SYS_NAND_U_BOOT_OFFS
3372 Location in NAND to read U-Boot from
3374 CONFIG_SYS_NAND_U_BOOT_DST
3375 Location in memory to load U-Boot to
3377 CONFIG_SYS_NAND_U_BOOT_SIZE
3378 Size of image to load
3380 CONFIG_SYS_NAND_U_BOOT_START
3381 Entry point in loaded image to jump to
3383 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3384 Define this if you need to first read the OOB and then the
3385 data. This is used for example on davinci plattforms.
3387 CONFIG_SPL_OMAP3_ID_NAND
3388 Support for an OMAP3-specific set of functions to return the
3389 ID and MFR of the first attached NAND chip, if present.
3391 CONFIG_SPL_SERIAL_SUPPORT
3392 Support for drivers/serial/libserial.o in SPL binary
3394 CONFIG_SPL_SPI_FLASH_SUPPORT
3395 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3397 CONFIG_SPL_SPI_SUPPORT
3398 Support for drivers/spi/libspi.o in SPL binary
3400 CONFIG_SPL_RAM_DEVICE
3401 Support for running image already present in ram, in SPL binary
3403 CONFIG_SPL_LIBGENERIC_SUPPORT
3404 Support for lib/libgeneric.o in SPL binary
3406 CONFIG_SPL_ENV_SUPPORT
3407 Support for the environment operating in SPL binary
3409 CONFIG_SPL_NET_SUPPORT
3410 Support for the net/libnet.o in SPL binary.
3411 It conflicts with SPL env from storage medium specified by
3412 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3415 Image offset to which the SPL should be padded before appending
3416 the SPL payload. By default, this is defined as
3417 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3418 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3419 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3422 Final target image containing SPL and payload. Some SPLs
3423 use an arch-specific makefile fragment instead, for
3424 example if more than one image needs to be produced.
3426 CONFIG_FIT_SPL_PRINT
3427 Printing information about a FIT image adds quite a bit of
3428 code to SPL. So this is normally disabled in SPL. Use this
3429 option to re-enable it. This will affect the output of the
3430 bootm command when booting a FIT image.
3434 Enable building of TPL globally.
3437 Image offset to which the TPL should be padded before appending
3438 the TPL payload. By default, this is defined as
3439 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3440 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3441 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3446 [so far only for SMDK2400 boards]
3448 - Modem support enable:
3449 CONFIG_MODEM_SUPPORT
3451 - RTS/CTS Flow control enable:
3454 - Modem debug support:
3455 CONFIG_MODEM_SUPPORT_DEBUG
3457 Enables debugging stuff (char screen[1024], dbg())
3458 for modem support. Useful only with BDI2000.
3460 - Interrupt support (PPC):
3462 There are common interrupt_init() and timer_interrupt()
3463 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3464 for CPU specific initialization. interrupt_init_cpu()
3465 should set decrementer_count to appropriate value. If
3466 CPU resets decrementer automatically after interrupt
3467 (ppc4xx) it should set decrementer_count to zero.
3468 timer_interrupt() calls timer_interrupt_cpu() for CPU
3469 specific handling. If board has watchdog / status_led
3470 / other_activity_monitor it works automatically from
3471 general timer_interrupt().
3475 In the target system modem support is enabled when a
3476 specific key (key combination) is pressed during
3477 power-on. Otherwise U-Boot will boot normally
3478 (autoboot). The key_pressed() function is called from
3479 board_init(). Currently key_pressed() is a dummy
3480 function, returning 1 and thus enabling modem
3483 If there are no modem init strings in the
3484 environment, U-Boot proceed to autoboot; the
3485 previous output (banner, info printfs) will be
3488 See also: doc/README.Modem
3490 Board initialization settings:
3491 ------------------------------
3493 During Initialization u-boot calls a number of board specific functions
3494 to allow the preparation of board specific prerequisites, e.g. pin setup
3495 before drivers are initialized. To enable these callbacks the
3496 following configuration macros have to be defined. Currently this is
3497 architecture specific, so please check arch/your_architecture/lib/board.c
3498 typically in board_init_f() and board_init_r().
3500 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3501 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3502 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3503 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3505 Configuration Settings:
3506 -----------------------
3508 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3509 Optionally it can be defined to support 64-bit memory commands.
3511 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3512 undefine this when you're short of memory.
3514 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3515 width of the commands listed in the 'help' command output.
3517 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3518 prompt for user input.
3520 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3522 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3524 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3526 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3527 the application (usually a Linux kernel) when it is
3530 - CONFIG_SYS_BAUDRATE_TABLE:
3531 List of legal baudrate settings for this board.
3533 - CONFIG_SYS_CONSOLE_INFO_QUIET
3534 Suppress display of console information at boot.
3536 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3537 If the board specific function
3538 extern int overwrite_console (void);
3539 returns 1, the stdin, stderr and stdout are switched to the
3540 serial port, else the settings in the environment are used.
3542 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3543 Enable the call to overwrite_console().
3545 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3546 Enable overwrite of previous console environment settings.
3548 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3549 Begin and End addresses of the area used by the
3552 - CONFIG_SYS_ALT_MEMTEST:
3553 Enable an alternate, more extensive memory test.
3555 - CONFIG_SYS_MEMTEST_SCRATCH:
3556 Scratch address used by the alternate memory test
3557 You only need to set this if address zero isn't writeable
3559 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3560 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3561 this specified memory area will get subtracted from the top
3562 (end) of RAM and won't get "touched" at all by U-Boot. By
3563 fixing up gd->ram_size the Linux kernel should gets passed
3564 the now "corrected" memory size and won't touch it either.
3565 This should work for arch/ppc and arch/powerpc. Only Linux
3566 board ports in arch/powerpc with bootwrapper support that
3567 recalculate the memory size from the SDRAM controller setup
3568 will have to get fixed in Linux additionally.
3570 This option can be used as a workaround for the 440EPx/GRx
3571 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3574 WARNING: Please make sure that this value is a multiple of
3575 the Linux page size (normally 4k). If this is not the case,
3576 then the end address of the Linux memory will be located at a
3577 non page size aligned address and this could cause major
3580 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3581 Enable temporary baudrate change while serial download
3583 - CONFIG_SYS_SDRAM_BASE:
3584 Physical start address of SDRAM. _Must_ be 0 here.
3586 - CONFIG_SYS_MBIO_BASE:
3587 Physical start address of Motherboard I/O (if using a
3590 - CONFIG_SYS_FLASH_BASE:
3591 Physical start address of Flash memory.
3593 - CONFIG_SYS_MONITOR_BASE:
3594 Physical start address of boot monitor code (set by
3595 make config files to be same as the text base address
3596 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3597 CONFIG_SYS_FLASH_BASE when booting from flash.
3599 - CONFIG_SYS_MONITOR_LEN:
3600 Size of memory reserved for monitor code, used to
3601 determine _at_compile_time_ (!) if the environment is
3602 embedded within the U-Boot image, or in a separate
3605 - CONFIG_SYS_MALLOC_LEN:
3606 Size of DRAM reserved for malloc() use.
3608 - CONFIG_SYS_BOOTM_LEN:
3609 Normally compressed uImages are limited to an
3610 uncompressed size of 8 MBytes. If this is not enough,
3611 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3612 to adjust this setting to your needs.
3614 - CONFIG_SYS_BOOTMAPSZ:
3615 Maximum size of memory mapped by the startup code of
3616 the Linux kernel; all data that must be processed by
3617 the Linux kernel (bd_info, boot arguments, FDT blob if
3618 used) must be put below this limit, unless "bootm_low"
3619 environment variable is defined and non-zero. In such case
3620 all data for the Linux kernel must be between "bootm_low"
3621 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3622 variable "bootm_mapsize" will override the value of
3623 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3624 then the value in "bootm_size" will be used instead.
3626 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3627 Enable initrd_high functionality. If defined then the
3628 initrd_high feature is enabled and the bootm ramdisk subcommand
3631 - CONFIG_SYS_BOOT_GET_CMDLINE:
3632 Enables allocating and saving kernel cmdline in space between
3633 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3635 - CONFIG_SYS_BOOT_GET_KBD:
3636 Enables allocating and saving a kernel copy of the bd_info in
3637 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3639 - CONFIG_SYS_MAX_FLASH_BANKS:
3640 Max number of Flash memory banks
3642 - CONFIG_SYS_MAX_FLASH_SECT:
3643 Max number of sectors on a Flash chip
3645 - CONFIG_SYS_FLASH_ERASE_TOUT:
3646 Timeout for Flash erase operations (in ms)
3648 - CONFIG_SYS_FLASH_WRITE_TOUT:
3649 Timeout for Flash write operations (in ms)
3651 - CONFIG_SYS_FLASH_LOCK_TOUT
3652 Timeout for Flash set sector lock bit operation (in ms)
3654 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3655 Timeout for Flash clear lock bits operation (in ms)
3657 - CONFIG_SYS_FLASH_PROTECTION
3658 If defined, hardware flash sectors protection is used
3659 instead of U-Boot software protection.
3661 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3663 Enable TFTP transfers directly to flash memory;
3664 without this option such a download has to be
3665 performed in two steps: (1) download to RAM, and (2)
3666 copy from RAM to flash.
3668 The two-step approach is usually more reliable, since
3669 you can check if the download worked before you erase
3670 the flash, but in some situations (when system RAM is
3671 too limited to allow for a temporary copy of the
3672 downloaded image) this option may be very useful.
3674 - CONFIG_SYS_FLASH_CFI:
3675 Define if the flash driver uses extra elements in the
3676 common flash structure for storing flash geometry.
3678 - CONFIG_FLASH_CFI_DRIVER
3679 This option also enables the building of the cfi_flash driver
3680 in the drivers directory
3682 - CONFIG_FLASH_CFI_MTD
3683 This option enables the building of the cfi_mtd driver
3684 in the drivers directory. The driver exports CFI flash
3687 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3688 Use buffered writes to flash.
3690 - CONFIG_FLASH_SPANSION_S29WS_N
3691 s29ws-n MirrorBit flash has non-standard addresses for buffered
3694 - CONFIG_SYS_FLASH_QUIET_TEST
3695 If this option is defined, the common CFI flash doesn't
3696 print it's warning upon not recognized FLASH banks. This
3697 is useful, if some of the configured banks are only
3698 optionally available.
3700 - CONFIG_FLASH_SHOW_PROGRESS
3701 If defined (must be an integer), print out countdown
3702 digits and dots. Recommended value: 45 (9..1) for 80
3703 column displays, 15 (3..1) for 40 column displays.
3705 - CONFIG_FLASH_VERIFY
3706 If defined, the content of the flash (destination) is compared
3707 against the source after the write operation. An error message
3708 will be printed when the contents are not identical.
3709 Please note that this option is useless in nearly all cases,
3710 since such flash programming errors usually are detected earlier
3711 while unprotecting/erasing/programming. Please only enable
3712 this option if you really know what you are doing.
3714 - CONFIG_SYS_RX_ETH_BUFFER:
3715 Defines the number of Ethernet receive buffers. On some
3716 Ethernet controllers it is recommended to set this value
3717 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3718 buffers can be full shortly after enabling the interface
3719 on high Ethernet traffic.
3720 Defaults to 4 if not defined.
3722 - CONFIG_ENV_MAX_ENTRIES
3724 Maximum number of entries in the hash table that is used
3725 internally to store the environment settings. The default
3726 setting is supposed to be generous and should work in most
3727 cases. This setting can be used to tune behaviour; see
3728 lib/hashtable.c for details.
3730 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3731 - CONFIG_ENV_FLAGS_LIST_STATIC
3732 Enable validation of the values given to environment variables when
3733 calling env set. Variables can be restricted to only decimal,
3734 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3735 the variables can also be restricted to IP address or MAC address.
3737 The format of the list is:
3738 type_attribute = [s|d|x|b|i|m]
3739 access_atribute = [a|r|o|c]
3740 attributes = type_attribute[access_atribute]
3741 entry = variable_name[:attributes]
3744 The type attributes are:
3745 s - String (default)
3748 b - Boolean ([1yYtT|0nNfF])
3752 The access attributes are:
3758 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3759 Define this to a list (string) to define the ".flags"
3760 envirnoment variable in the default or embedded environment.
3762 - CONFIG_ENV_FLAGS_LIST_STATIC
3763 Define this to a list (string) to define validation that
3764 should be done if an entry is not found in the ".flags"
3765 environment variable. To override a setting in the static
3766 list, simply add an entry for the same variable name to the
3769 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3770 If defined, don't allow the -f switch to env set override variable
3773 - CONFIG_SYS_GENERIC_BOARD
3774 This selects the architecture-generic board system instead of the
3775 architecture-specific board files. It is intended to move boards
3776 to this new framework over time. Defining this will disable the
3777 arch/foo/lib/board.c file and use common/board_f.c and
3778 common/board_r.c instead. To use this option your architecture
3779 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3780 its config.mk file). If you find problems enabling this option on
3781 your board please report the problem and send patches!
3783 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3784 This is set by OMAP boards for the max time that reset should
3785 be asserted. See doc/README.omap-reset-time for details on how
3786 the value can be calulated on a given board.
3788 The following definitions that deal with the placement and management
3789 of environment data (variable area); in general, we support the
3790 following configurations:
3792 - CONFIG_BUILD_ENVCRC:
3794 Builds up envcrc with the target environment so that external utils
3795 may easily extract it and embed it in final U-Boot images.
3797 - CONFIG_ENV_IS_IN_FLASH:
3799 Define this if the environment is in flash memory.
3801 a) The environment occupies one whole flash sector, which is
3802 "embedded" in the text segment with the U-Boot code. This
3803 happens usually with "bottom boot sector" or "top boot
3804 sector" type flash chips, which have several smaller
3805 sectors at the start or the end. For instance, such a
3806 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3807 such a case you would place the environment in one of the
3808 4 kB sectors - with U-Boot code before and after it. With
3809 "top boot sector" type flash chips, you would put the
3810 environment in one of the last sectors, leaving a gap
3811 between U-Boot and the environment.
3813 - CONFIG_ENV_OFFSET:
3815 Offset of environment data (variable area) to the
3816 beginning of flash memory; for instance, with bottom boot
3817 type flash chips the second sector can be used: the offset
3818 for this sector is given here.
3820 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3824 This is just another way to specify the start address of
3825 the flash sector containing the environment (instead of
3828 - CONFIG_ENV_SECT_SIZE:
3830 Size of the sector containing the environment.
3833 b) Sometimes flash chips have few, equal sized, BIG sectors.
3834 In such a case you don't want to spend a whole sector for
3839 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3840 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3841 of this flash sector for the environment. This saves
3842 memory for the RAM copy of the environment.
3844 It may also save flash memory if you decide to use this
3845 when your environment is "embedded" within U-Boot code,
3846 since then the remainder of the flash sector could be used
3847 for U-Boot code. It should be pointed out that this is
3848 STRONGLY DISCOURAGED from a robustness point of view:
3849 updating the environment in flash makes it always
3850 necessary to erase the WHOLE sector. If something goes
3851 wrong before the contents has been restored from a copy in
3852 RAM, your target system will be dead.
3854 - CONFIG_ENV_ADDR_REDUND
3855 CONFIG_ENV_SIZE_REDUND
3857 These settings describe a second storage area used to hold
3858 a redundant copy of the environment data, so that there is
3859 a valid backup copy in case there is a power failure during
3860 a "saveenv" operation.
3862 BE CAREFUL! Any changes to the flash layout, and some changes to the
3863 source code will make it necessary to adapt <board>/u-boot.lds*
3867 - CONFIG_ENV_IS_IN_NVRAM:
3869 Define this if you have some non-volatile memory device
3870 (NVRAM, battery buffered SRAM) which you want to use for the
3876 These two #defines are used to determine the memory area you
3877 want to use for environment. It is assumed that this memory
3878 can just be read and written to, without any special
3881 BE CAREFUL! The first access to the environment happens quite early
3882 in U-Boot initalization (when we try to get the setting of for the
3883 console baudrate). You *MUST* have mapped your NVRAM area then, or
3886 Please note that even with NVRAM we still use a copy of the
3887 environment in RAM: we could work on NVRAM directly, but we want to
3888 keep settings there always unmodified except somebody uses "saveenv"
3889 to save the current settings.
3892 - CONFIG_ENV_IS_IN_EEPROM:
3894 Use this if you have an EEPROM or similar serial access
3895 device and a driver for it.
3897 - CONFIG_ENV_OFFSET:
3900 These two #defines specify the offset and size of the
3901 environment area within the total memory of your EEPROM.
3903 - CONFIG_SYS_I2C_EEPROM_ADDR:
3904 If defined, specified the chip address of the EEPROM device.
3905 The default address is zero.
3907 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3908 If defined, the number of bits used to address bytes in a
3909 single page in the EEPROM device. A 64 byte page, for example
3910 would require six bits.
3912 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3913 If defined, the number of milliseconds to delay between
3914 page writes. The default is zero milliseconds.
3916 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3917 The length in bytes of the EEPROM memory array address. Note
3918 that this is NOT the chip address length!
3920 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3921 EEPROM chips that implement "address overflow" are ones
3922 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3923 address and the extra bits end up in the "chip address" bit
3924 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3927 Note that we consider the length of the address field to
3928 still be one byte because the extra address bits are hidden
3929 in the chip address.
3931 - CONFIG_SYS_EEPROM_SIZE:
3932 The size in bytes of the EEPROM device.
3934 - CONFIG_ENV_EEPROM_IS_ON_I2C
3935 define this, if you have I2C and SPI activated, and your
3936 EEPROM, which holds the environment, is on the I2C bus.
3938 - CONFIG_I2C_ENV_EEPROM_BUS
3939 if you have an Environment on an EEPROM reached over
3940 I2C muxes, you can define here, how to reach this
3941 EEPROM. For example:
3943 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3945 EEPROM which holds the environment, is reached over
3946 a pca9547 i2c mux with address 0x70, channel 3.
3948 - CONFIG_ENV_IS_IN_DATAFLASH:
3950 Define this if you have a DataFlash memory device which you
3951 want to use for the environment.
3953 - CONFIG_ENV_OFFSET:
3957 These three #defines specify the offset and size of the
3958 environment area within the total memory of your DataFlash placed
3959 at the specified address.
3961 - CONFIG_ENV_IS_IN_REMOTE:
3963 Define this if you have a remote memory space which you
3964 want to use for the local device's environment.
3969 These two #defines specify the address and size of the
3970 environment area within the remote memory space. The
3971 local device can get the environment from remote memory
3972 space by SRIO or PCIE links.
3974 BE CAREFUL! For some special cases, the local device can not use
3975 "saveenv" command. For example, the local device will get the
3976 environment stored in a remote NOR flash by SRIO or PCIE link,
3977 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3979 - CONFIG_ENV_IS_IN_NAND:
3981 Define this if you have a NAND device which you want to use
3982 for the environment.
3984 - CONFIG_ENV_OFFSET:
3987 These two #defines specify the offset and size of the environment
3988 area within the first NAND device. CONFIG_ENV_OFFSET must be
3989 aligned to an erase block boundary.
3991 - CONFIG_ENV_OFFSET_REDUND (optional):
3993 This setting describes a second storage area of CONFIG_ENV_SIZE
3994 size used to hold a redundant copy of the environment data, so
3995 that there is a valid backup copy in case there is a power failure
3996 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3997 aligned to an erase block boundary.
3999 - CONFIG_ENV_RANGE (optional):
4001 Specifies the length of the region in which the environment
4002 can be written. This should be a multiple of the NAND device's
4003 block size. Specifying a range with more erase blocks than
4004 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4005 the range to be avoided.
4007 - CONFIG_ENV_OFFSET_OOB (optional):
4009 Enables support for dynamically retrieving the offset of the
4010 environment from block zero's out-of-band data. The
4011 "nand env.oob" command can be used to record this offset.
4012 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4013 using CONFIG_ENV_OFFSET_OOB.
4015 - CONFIG_NAND_ENV_DST
4017 Defines address in RAM to which the nand_spl code should copy the
4018 environment. If redundant environment is used, it will be copied to
4019 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4021 - CONFIG_ENV_IS_IN_UBI:
4023 Define this if you have an UBI volume that you want to use for the
4024 environment. This has the benefit of wear-leveling the environment
4025 accesses, which is important on NAND.
4027 - CONFIG_ENV_UBI_PART:
4029 Define this to a string that is the mtd partition containing the UBI.
4031 - CONFIG_ENV_UBI_VOLUME:
4033 Define this to the name of the volume that you want to store the
4036 - CONFIG_ENV_UBI_VOLUME_REDUND:
4038 Define this to the name of another volume to store a second copy of
4039 the environment in. This will enable redundant environments in UBI.
4040 It is assumed that both volumes are in the same MTD partition.
4042 - CONFIG_UBI_SILENCE_MSG
4043 - CONFIG_UBIFS_SILENCE_MSG
4045 You will probably want to define these to avoid a really noisy system
4046 when storing the env in UBI.
4048 - CONFIG_ENV_IS_IN_MMC:
4050 Define this if you have an MMC device which you want to use for the
4053 - CONFIG_SYS_MMC_ENV_DEV:
4055 Specifies which MMC device the environment is stored in.
4057 - CONFIG_SYS_MMC_ENV_PART (optional):
4059 Specifies which MMC partition the environment is stored in. If not
4060 set, defaults to partition 0, the user area. Common values might be
4061 1 (first MMC boot partition), 2 (second MMC boot partition).
4063 - CONFIG_ENV_OFFSET:
4066 These two #defines specify the offset and size of the environment
4067 area within the specified MMC device.
4069 If offset is positive (the usual case), it is treated as relative to
4070 the start of the MMC partition. If offset is negative, it is treated
4071 as relative to the end of the MMC partition. This can be useful if
4072 your board may be fitted with different MMC devices, which have
4073 different sizes for the MMC partitions, and you always want the
4074 environment placed at the very end of the partition, to leave the
4075 maximum possible space before it, to store other data.
4077 These two values are in units of bytes, but must be aligned to an
4078 MMC sector boundary.
4080 - CONFIG_ENV_OFFSET_REDUND (optional):
4082 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4083 hold a redundant copy of the environment data. This provides a
4084 valid backup copy in case the other copy is corrupted, e.g. due
4085 to a power failure during a "saveenv" operation.
4087 This value may also be positive or negative; this is handled in the
4088 same way as CONFIG_ENV_OFFSET.
4090 This value is also in units of bytes, but must also be aligned to
4091 an MMC sector boundary.
4093 - CONFIG_ENV_SIZE_REDUND (optional):
4095 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4096 set. If this value is set, it must be set to the same value as
4099 - CONFIG_SYS_SPI_INIT_OFFSET
4101 Defines offset to the initial SPI buffer area in DPRAM. The
4102 area is used at an early stage (ROM part) if the environment
4103 is configured to reside in the SPI EEPROM: We need a 520 byte
4104 scratch DPRAM area. It is used between the two initialization
4105 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4106 to be a good choice since it makes it far enough from the
4107 start of the data area as well as from the stack pointer.
4109 Please note that the environment is read-only until the monitor
4110 has been relocated to RAM and a RAM copy of the environment has been
4111 created; also, when using EEPROM you will have to use getenv_f()
4112 until then to read environment variables.
4114 The environment is protected by a CRC32 checksum. Before the monitor
4115 is relocated into RAM, as a result of a bad CRC you will be working
4116 with the compiled-in default environment - *silently*!!! [This is
4117 necessary, because the first environment variable we need is the
4118 "baudrate" setting for the console - if we have a bad CRC, we don't
4119 have any device yet where we could complain.]
4121 Note: once the monitor has been relocated, then it will complain if
4122 the default environment is used; a new CRC is computed as soon as you
4123 use the "saveenv" command to store a valid environment.
4125 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4126 Echo the inverted Ethernet link state to the fault LED.
4128 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4129 also needs to be defined.
4131 - CONFIG_SYS_FAULT_MII_ADDR:
4132 MII address of the PHY to check for the Ethernet link state.
4134 - CONFIG_NS16550_MIN_FUNCTIONS:
4135 Define this if you desire to only have use of the NS16550_init
4136 and NS16550_putc functions for the serial driver located at
4137 drivers/serial/ns16550.c. This option is useful for saving
4138 space for already greatly restricted images, including but not
4139 limited to NAND_SPL configurations.
4141 - CONFIG_DISPLAY_BOARDINFO
4142 Display information about the board that U-Boot is running on
4143 when U-Boot starts up. The board function checkboard() is called
4146 - CONFIG_DISPLAY_BOARDINFO_LATE
4147 Similar to the previous option, but display this information
4148 later, once stdio is running and output goes to the LCD, if
4151 Low Level (hardware related) configuration options:
4152 ---------------------------------------------------
4154 - CONFIG_SYS_CACHELINE_SIZE:
4155 Cache Line Size of the CPU.
4157 - CONFIG_SYS_DEFAULT_IMMR:
4158 Default address of the IMMR after system reset.
4160 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4161 and RPXsuper) to be able to adjust the position of
4162 the IMMR register after a reset.
4164 - CONFIG_SYS_CCSRBAR_DEFAULT:
4165 Default (power-on reset) physical address of CCSR on Freescale
4168 - CONFIG_SYS_CCSRBAR:
4169 Virtual address of CCSR. On a 32-bit build, this is typically
4170 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4172 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4173 for cross-platform code that uses that macro instead.
4175 - CONFIG_SYS_CCSRBAR_PHYS:
4176 Physical address of CCSR. CCSR can be relocated to a new
4177 physical address, if desired. In this case, this macro should
4178 be set to that address. Otherwise, it should be set to the
4179 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4180 is typically relocated on 36-bit builds. It is recommended
4181 that this macro be defined via the _HIGH and _LOW macros:
4183 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4184 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4186 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4187 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4188 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4189 used in assembly code, so it must not contain typecasts or
4190 integer size suffixes (e.g. "ULL").
4192 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4193 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4194 used in assembly code, so it must not contain typecasts or
4195 integer size suffixes (e.g. "ULL").
4197 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4198 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4199 forced to a value that ensures that CCSR is not relocated.
4201 - Floppy Disk Support:
4202 CONFIG_SYS_FDC_DRIVE_NUMBER
4204 the default drive number (default value 0)
4206 CONFIG_SYS_ISA_IO_STRIDE
4208 defines the spacing between FDC chipset registers
4211 CONFIG_SYS_ISA_IO_OFFSET
4213 defines the offset of register from address. It
4214 depends on which part of the data bus is connected to
4215 the FDC chipset. (default value 0)
4217 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4218 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4221 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4222 fdc_hw_init() is called at the beginning of the FDC
4223 setup. fdc_hw_init() must be provided by the board
4224 source code. It is used to make hardware dependant
4228 Most IDE controllers were designed to be connected with PCI
4229 interface. Only few of them were designed for AHB interface.
4230 When software is doing ATA command and data transfer to
4231 IDE devices through IDE-AHB controller, some additional
4232 registers accessing to these kind of IDE-AHB controller
4235 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4236 DO NOT CHANGE unless you know exactly what you're
4237 doing! (11-4) [MPC8xx/82xx systems only]
4239 - CONFIG_SYS_INIT_RAM_ADDR:
4241 Start address of memory area that can be used for
4242 initial data and stack; please note that this must be
4243 writable memory that is working WITHOUT special
4244 initialization, i. e. you CANNOT use normal RAM which
4245 will become available only after programming the
4246 memory controller and running certain initialization
4249 U-Boot uses the following memory types:
4250 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4251 - MPC824X: data cache
4252 - PPC4xx: data cache
4254 - CONFIG_SYS_GBL_DATA_OFFSET:
4256 Offset of the initial data structure in the memory
4257 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4258 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4259 data is located at the end of the available space
4260 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4261 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4262 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4263 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4266 On the MPC824X (or other systems that use the data
4267 cache for initial memory) the address chosen for
4268 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4269 point to an otherwise UNUSED address space between
4270 the top of RAM and the start of the PCI space.
4272 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4274 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4276 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4278 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4280 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4282 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4284 - CONFIG_SYS_OR_TIMING_SDRAM:
4287 - CONFIG_SYS_MAMR_PTA:
4288 periodic timer for refresh
4290 - CONFIG_SYS_DER: Debug Event Register (37-47)
4292 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4293 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4294 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4295 CONFIG_SYS_BR1_PRELIM:
4296 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4298 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4299 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4300 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4301 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4303 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4304 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4305 Machine Mode Register and Memory Periodic Timer
4306 Prescaler definitions (SDRAM timing)
4308 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4309 enable I2C microcode relocation patch (MPC8xx);
4310 define relocation offset in DPRAM [DSP2]
4312 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4313 enable SMC microcode relocation patch (MPC8xx);
4314 define relocation offset in DPRAM [SMC1]
4316 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4317 enable SPI microcode relocation patch (MPC8xx);
4318 define relocation offset in DPRAM [SCC4]
4320 - CONFIG_SYS_USE_OSCCLK:
4321 Use OSCM clock mode on MBX8xx board. Be careful,
4322 wrong setting might damage your board. Read
4323 doc/README.MBX before setting this variable!
4325 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4326 Offset of the bootmode word in DPRAM used by post
4327 (Power On Self Tests). This definition overrides
4328 #define'd default value in commproc.h resp.
4331 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4332 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4333 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4334 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4335 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4336 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4337 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4338 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4339 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4341 - CONFIG_PCI_DISABLE_PCIE:
4342 Disable PCI-Express on systems where it is supported but not
4345 - CONFIG_PCI_ENUM_ONLY
4346 Only scan through and get the devices on the busses.
4347 Don't do any setup work, presumably because someone or
4348 something has already done it, and we don't need to do it
4349 a second time. Useful for platforms that are pre-booted
4350 by coreboot or similar.
4352 - CONFIG_PCI_INDIRECT_BRIDGE:
4353 Enable support for indirect PCI bridges.
4356 Chip has SRIO or not
4359 Board has SRIO 1 port available
4362 Board has SRIO 2 port available
4364 - CONFIG_SRIO_PCIE_BOOT_MASTER
4365 Board can support master function for Boot from SRIO and PCIE
4367 - CONFIG_SYS_SRIOn_MEM_VIRT:
4368 Virtual Address of SRIO port 'n' memory region
4370 - CONFIG_SYS_SRIOn_MEM_PHYS:
4371 Physical Address of SRIO port 'n' memory region
4373 - CONFIG_SYS_SRIOn_MEM_SIZE:
4374 Size of SRIO port 'n' memory region
4376 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4377 Defined to tell the NAND controller that the NAND chip is using
4379 Not all NAND drivers use this symbol.
4380 Example of drivers that use it:
4381 - drivers/mtd/nand/ndfc.c
4382 - drivers/mtd/nand/mxc_nand.c
4384 - CONFIG_SYS_NDFC_EBC0_CFG
4385 Sets the EBC0_CFG register for the NDFC. If not defined
4386 a default value will be used.
4389 Get DDR timing information from an I2C EEPROM. Common
4390 with pluggable memory modules such as SODIMMs
4393 I2C address of the SPD EEPROM
4395 - CONFIG_SYS_SPD_BUS_NUM
4396 If SPD EEPROM is on an I2C bus other than the first
4397 one, specify here. Note that the value must resolve
4398 to something your driver can deal with.
4400 - CONFIG_SYS_DDR_RAW_TIMING
4401 Get DDR timing information from other than SPD. Common with
4402 soldered DDR chips onboard without SPD. DDR raw timing
4403 parameters are extracted from datasheet and hard-coded into
4404 header files or board specific files.
4406 - CONFIG_FSL_DDR_INTERACTIVE
4407 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4409 - CONFIG_SYS_83XX_DDR_USES_CS0
4410 Only for 83xx systems. If specified, then DDR should
4411 be configured using CS0 and CS1 instead of CS2 and CS3.
4413 - CONFIG_ETHER_ON_FEC[12]
4414 Define to enable FEC[12] on a 8xx series processor.
4416 - CONFIG_FEC[12]_PHY
4417 Define to the hardcoded PHY address which corresponds
4418 to the given FEC; i. e.
4419 #define CONFIG_FEC1_PHY 4
4420 means that the PHY with address 4 is connected to FEC1
4422 When set to -1, means to probe for first available.
4424 - CONFIG_FEC[12]_PHY_NORXERR
4425 The PHY does not have a RXERR line (RMII only).
4426 (so program the FEC to ignore it).
4429 Enable RMII mode for all FECs.
4430 Note that this is a global option, we can't
4431 have one FEC in standard MII mode and another in RMII mode.
4433 - CONFIG_CRC32_VERIFY
4434 Add a verify option to the crc32 command.
4437 => crc32 -v <address> <count> <crc32>
4439 Where address/count indicate a memory area
4440 and crc32 is the correct crc32 which the
4444 Add the "loopw" memory command. This only takes effect if
4445 the memory commands are activated globally (CONFIG_CMD_MEM).
4448 Add the "mdc" and "mwc" memory commands. These are cyclic
4453 This command will print 4 bytes (10,11,12,13) each 500 ms.
4455 => mwc.l 100 12345678 10
4456 This command will write 12345678 to address 100 all 10 ms.
4458 This only takes effect if the memory commands are activated
4459 globally (CONFIG_CMD_MEM).
4461 - CONFIG_SKIP_LOWLEVEL_INIT
4462 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4463 low level initializations (like setting up the memory
4464 controller) are omitted and/or U-Boot does not
4465 relocate itself into RAM.
4467 Normally this variable MUST NOT be defined. The only
4468 exception is when U-Boot is loaded (to RAM) by some
4469 other boot loader or by a debugger which performs
4470 these initializations itself.
4473 Modifies the behaviour of start.S when compiling a loader
4474 that is executed before the actual U-Boot. E.g. when
4475 compiling a NAND SPL.
4478 Modifies the behaviour of start.S when compiling a loader
4479 that is executed after the SPL and before the actual U-Boot.
4480 It is loaded by the SPL.
4482 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4483 Only for 85xx systems. If this variable is specified, the section
4484 .resetvec is not kept and the section .bootpg is placed in the
4485 previous 4k of the .text section.
4487 - CONFIG_ARCH_MAP_SYSMEM
4488 Generally U-Boot (and in particular the md command) uses
4489 effective address. It is therefore not necessary to regard
4490 U-Boot address as virtual addresses that need to be translated
4491 to physical addresses. However, sandbox requires this, since
4492 it maintains its own little RAM buffer which contains all
4493 addressable memory. This option causes some memory accesses
4494 to be mapped through map_sysmem() / unmap_sysmem().
4496 - CONFIG_USE_ARCH_MEMCPY
4497 CONFIG_USE_ARCH_MEMSET
4498 If these options are used a optimized version of memcpy/memset will
4499 be used if available. These functions may be faster under some
4500 conditions but may increase the binary size.
4502 - CONFIG_X86_RESET_VECTOR
4503 If defined, the x86 reset vector code is included. This is not
4504 needed when U-Boot is running from Coreboot.
4507 Defines the MPU clock speed (in MHz).
4509 NOTE : currently only supported on AM335x platforms.
4511 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4512 Enables the RTC32K OSC on AM33xx based plattforms
4514 Freescale QE/FMAN Firmware Support:
4515 -----------------------------------
4517 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4518 loading of "firmware", which is encoded in the QE firmware binary format.
4519 This firmware often needs to be loaded during U-Boot booting, so macros
4520 are used to identify the storage device (NOR flash, SPI, etc) and the address
4523 - CONFIG_SYS_FMAN_FW_ADDR
4524 The address in the storage device where the FMAN microcode is located. The
4525 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4528 - CONFIG_SYS_QE_FW_ADDR
4529 The address in the storage device where the QE microcode is located. The
4530 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4533 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4534 The maximum possible size of the firmware. The firmware binary format
4535 has a field that specifies the actual size of the firmware, but it
4536 might not be possible to read any part of the firmware unless some
4537 local storage is allocated to hold the entire firmware first.
4539 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4540 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4541 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4542 virtual address in NOR flash.
4544 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4545 Specifies that QE/FMAN firmware is located in NAND flash.
4546 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4548 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4549 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4550 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4552 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4553 Specifies that QE/FMAN firmware is located on the primary SPI
4554 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4556 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4557 Specifies that QE/FMAN firmware is located in the remote (master)
4558 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4559 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4560 window->master inbound window->master LAW->the ucode address in
4561 master's memory space.
4563 Building the Software:
4564 ======================
4566 Building U-Boot has been tested in several native build environments
4567 and in many different cross environments. Of course we cannot support
4568 all possibly existing versions of cross development tools in all
4569 (potentially obsolete) versions. In case of tool chain problems we
4570 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4571 which is extensively used to build and test U-Boot.
4573 If you are not using a native environment, it is assumed that you
4574 have GNU cross compiling tools available in your path. In this case,
4575 you must set the environment variable CROSS_COMPILE in your shell.
4576 Note that no changes to the Makefile or any other source files are
4577 necessary. For example using the ELDK on a 4xx CPU, please enter:
4579 $ CROSS_COMPILE=ppc_4xx-
4580 $ export CROSS_COMPILE
4582 Note: If you wish to generate Windows versions of the utilities in
4583 the tools directory you can use the MinGW toolchain
4584 (http://www.mingw.org). Set your HOST tools to the MinGW
4585 toolchain and execute 'make tools'. For example:
4587 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4589 Binaries such as tools/mkimage.exe will be created which can
4590 be executed on computers running Windows.
4592 U-Boot is intended to be simple to build. After installing the
4593 sources you must configure U-Boot for one specific board type. This
4598 where "NAME_config" is the name of one of the existing configu-
4599 rations; see boards.cfg for supported names.
4601 Note: for some board special configuration names may exist; check if
4602 additional information is available from the board vendor; for
4603 instance, the TQM823L systems are available without (standard)
4604 or with LCD support. You can select such additional "features"
4605 when choosing the configuration, i. e.
4608 - will configure for a plain TQM823L, i. e. no LCD support
4610 make TQM823L_LCD_config
4611 - will configure for a TQM823L with U-Boot console on LCD
4616 Finally, type "make all", and you should get some working U-Boot
4617 images ready for download to / installation on your system:
4619 - "u-boot.bin" is a raw binary image
4620 - "u-boot" is an image in ELF binary format
4621 - "u-boot.srec" is in Motorola S-Record format
4623 By default the build is performed locally and the objects are saved
4624 in the source directory. One of the two methods can be used to change
4625 this behavior and build U-Boot to some external directory:
4627 1. Add O= to the make command line invocations:
4629 make O=/tmp/build distclean
4630 make O=/tmp/build NAME_config
4631 make O=/tmp/build all
4633 2. Set environment variable BUILD_DIR to point to the desired location:
4635 export BUILD_DIR=/tmp/build
4640 Note that the command line "O=" setting overrides the BUILD_DIR environment
4644 Please be aware that the Makefiles assume you are using GNU make, so
4645 for instance on NetBSD you might need to use "gmake" instead of
4649 If the system board that you have is not listed, then you will need
4650 to port U-Boot to your hardware platform. To do this, follow these
4653 1. Add a new configuration option for your board to the toplevel
4654 "boards.cfg" file, using the existing entries as examples.
4655 Follow the instructions there to keep the boards in order.
4656 2. Create a new directory to hold your board specific code. Add any
4657 files you need. In your board directory, you will need at least
4658 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4659 3. Create a new configuration file "include/configs/<board>.h" for
4661 3. If you're porting U-Boot to a new CPU, then also create a new
4662 directory to hold your CPU specific code. Add any files you need.
4663 4. Run "make <board>_config" with your new name.
4664 5. Type "make", and you should get a working "u-boot.srec" file
4665 to be installed on your target system.
4666 6. Debug and solve any problems that might arise.
4667 [Of course, this last step is much harder than it sounds.]
4670 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4671 ==============================================================
4673 If you have modified U-Boot sources (for instance added a new board
4674 or support for new devices, a new CPU, etc.) you are expected to
4675 provide feedback to the other developers. The feedback normally takes
4676 the form of a "patch", i. e. a context diff against a certain (latest
4677 official or latest in the git repository) version of U-Boot sources.
4679 But before you submit such a patch, please verify that your modifi-
4680 cation did not break existing code. At least make sure that *ALL* of
4681 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4682 just run the "MAKEALL" script, which will configure and build U-Boot
4683 for ALL supported system. Be warned, this will take a while. You can
4684 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4685 environment variable to the script, i. e. to use the ELDK cross tools
4688 CROSS_COMPILE=ppc_8xx- MAKEALL
4690 or to build on a native PowerPC system you can type
4692 CROSS_COMPILE=' ' MAKEALL
4694 When using the MAKEALL script, the default behaviour is to build
4695 U-Boot in the source directory. This location can be changed by
4696 setting the BUILD_DIR environment variable. Also, for each target
4697 built, the MAKEALL script saves two log files (<target>.ERR and
4698 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4699 location can be changed by setting the MAKEALL_LOGDIR environment
4700 variable. For example:
4702 export BUILD_DIR=/tmp/build
4703 export MAKEALL_LOGDIR=/tmp/log
4704 CROSS_COMPILE=ppc_8xx- MAKEALL
4706 With the above settings build objects are saved in the /tmp/build,
4707 log files are saved in the /tmp/log and the source tree remains clean
4708 during the whole build process.
4711 See also "U-Boot Porting Guide" below.
4714 Monitor Commands - Overview:
4715 ============================
4717 go - start application at address 'addr'
4718 run - run commands in an environment variable
4719 bootm - boot application image from memory
4720 bootp - boot image via network using BootP/TFTP protocol
4721 bootz - boot zImage from memory
4722 tftpboot- boot image via network using TFTP protocol
4723 and env variables "ipaddr" and "serverip"
4724 (and eventually "gatewayip")
4725 tftpput - upload a file via network using TFTP protocol
4726 rarpboot- boot image via network using RARP/TFTP protocol
4727 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4728 loads - load S-Record file over serial line
4729 loadb - load binary file over serial line (kermit mode)
4731 mm - memory modify (auto-incrementing)
4732 nm - memory modify (constant address)
4733 mw - memory write (fill)
4735 cmp - memory compare
4736 crc32 - checksum calculation
4737 i2c - I2C sub-system
4738 sspi - SPI utility commands
4739 base - print or set address offset
4740 printenv- print environment variables
4741 setenv - set environment variables
4742 saveenv - save environment variables to persistent storage
4743 protect - enable or disable FLASH write protection
4744 erase - erase FLASH memory
4745 flinfo - print FLASH memory information
4746 nand - NAND memory operations (see doc/README.nand)
4747 bdinfo - print Board Info structure
4748 iminfo - print header information for application image
4749 coninfo - print console devices and informations
4750 ide - IDE sub-system
4751 loop - infinite loop on address range
4752 loopw - infinite write loop on address range
4753 mtest - simple RAM test
4754 icache - enable or disable instruction cache
4755 dcache - enable or disable data cache
4756 reset - Perform RESET of the CPU
4757 echo - echo args to console
4758 version - print monitor version
4759 help - print online help
4760 ? - alias for 'help'
4763 Monitor Commands - Detailed Description:
4764 ========================================
4768 For now: just type "help <command>".
4771 Environment Variables:
4772 ======================
4774 U-Boot supports user configuration using Environment Variables which
4775 can be made persistent by saving to Flash memory.
4777 Environment Variables are set using "setenv", printed using
4778 "printenv", and saved to Flash using "saveenv". Using "setenv"
4779 without a value can be used to delete a variable from the
4780 environment. As long as you don't save the environment you are
4781 working with an in-memory copy. In case the Flash area containing the
4782 environment is erased by accident, a default environment is provided.
4784 Some configuration options can be set using Environment Variables.
4786 List of environment variables (most likely not complete):
4788 baudrate - see CONFIG_BAUDRATE
4790 bootdelay - see CONFIG_BOOTDELAY
4792 bootcmd - see CONFIG_BOOTCOMMAND
4794 bootargs - Boot arguments when booting an RTOS image
4796 bootfile - Name of the image to load with TFTP
4798 bootm_low - Memory range available for image processing in the bootm
4799 command can be restricted. This variable is given as
4800 a hexadecimal number and defines lowest address allowed
4801 for use by the bootm command. See also "bootm_size"
4802 environment variable. Address defined by "bootm_low" is
4803 also the base of the initial memory mapping for the Linux
4804 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4807 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4808 This variable is given as a hexadecimal number and it
4809 defines the size of the memory region starting at base
4810 address bootm_low that is accessible by the Linux kernel
4811 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4812 as the default value if it is defined, and bootm_size is
4815 bootm_size - Memory range available for image processing in the bootm
4816 command can be restricted. This variable is given as
4817 a hexadecimal number and defines the size of the region
4818 allowed for use by the bootm command. See also "bootm_low"
4819 environment variable.
4821 updatefile - Location of the software update file on a TFTP server, used
4822 by the automatic software update feature. Please refer to
4823 documentation in doc/README.update for more details.
4825 autoload - if set to "no" (any string beginning with 'n'),
4826 "bootp" will just load perform a lookup of the
4827 configuration from the BOOTP server, but not try to
4828 load any image using TFTP
4830 autostart - if set to "yes", an image loaded using the "bootp",
4831 "rarpboot", "tftpboot" or "diskboot" commands will
4832 be automatically started (by internally calling
4835 If set to "no", a standalone image passed to the
4836 "bootm" command will be copied to the load address
4837 (and eventually uncompressed), but NOT be started.
4838 This can be used to load and uncompress arbitrary
4841 fdt_high - if set this restricts the maximum address that the
4842 flattened device tree will be copied into upon boot.
4843 For example, if you have a system with 1 GB memory
4844 at physical address 0x10000000, while Linux kernel
4845 only recognizes the first 704 MB as low memory, you
4846 may need to set fdt_high as 0x3C000000 to have the
4847 device tree blob be copied to the maximum address
4848 of the 704 MB low memory, so that Linux kernel can
4849 access it during the boot procedure.
4851 If this is set to the special value 0xFFFFFFFF then
4852 the fdt will not be copied at all on boot. For this
4853 to work it must reside in writable memory, have
4854 sufficient padding on the end of it for u-boot to
4855 add the information it needs into it, and the memory
4856 must be accessible by the kernel.
4858 fdtcontroladdr- if set this is the address of the control flattened
4859 device tree used by U-Boot when CONFIG_OF_CONTROL is
4862 i2cfast - (PPC405GP|PPC405EP only)
4863 if set to 'y' configures Linux I2C driver for fast
4864 mode (400kHZ). This environment variable is used in
4865 initialization code. So, for changes to be effective
4866 it must be saved and board must be reset.
4868 initrd_high - restrict positioning of initrd images:
4869 If this variable is not set, initrd images will be
4870 copied to the highest possible address in RAM; this
4871 is usually what you want since it allows for
4872 maximum initrd size. If for some reason you want to
4873 make sure that the initrd image is loaded below the
4874 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4875 variable to a value of "no" or "off" or "0".
4876 Alternatively, you can set it to a maximum upper
4877 address to use (U-Boot will still check that it
4878 does not overwrite the U-Boot stack and data).
4880 For instance, when you have a system with 16 MB
4881 RAM, and want to reserve 4 MB from use by Linux,
4882 you can do this by adding "mem=12M" to the value of
4883 the "bootargs" variable. However, now you must make
4884 sure that the initrd image is placed in the first
4885 12 MB as well - this can be done with
4887 setenv initrd_high 00c00000
4889 If you set initrd_high to 0xFFFFFFFF, this is an
4890 indication to U-Boot that all addresses are legal
4891 for the Linux kernel, including addresses in flash
4892 memory. In this case U-Boot will NOT COPY the
4893 ramdisk at all. This may be useful to reduce the
4894 boot time on your system, but requires that this
4895 feature is supported by your Linux kernel.
4897 ipaddr - IP address; needed for tftpboot command
4899 loadaddr - Default load address for commands like "bootp",
4900 "rarpboot", "tftpboot", "loadb" or "diskboot"
4902 loads_echo - see CONFIG_LOADS_ECHO
4904 serverip - TFTP server IP address; needed for tftpboot command
4906 bootretry - see CONFIG_BOOT_RETRY_TIME
4908 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4910 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4912 ethprime - controls which interface is used first.
4914 ethact - controls which interface is currently active.
4915 For example you can do the following
4917 => setenv ethact FEC
4918 => ping 192.168.0.1 # traffic sent on FEC
4919 => setenv ethact SCC
4920 => ping 10.0.0.1 # traffic sent on SCC
4922 ethrotate - When set to "no" U-Boot does not go through all
4923 available network interfaces.
4924 It just stays at the currently selected interface.
4926 netretry - When set to "no" each network operation will
4927 either succeed or fail without retrying.
4928 When set to "once" the network operation will
4929 fail when all the available network interfaces
4930 are tried once without success.
4931 Useful on scripts which control the retry operation
4934 npe_ucode - set load address for the NPE microcode
4936 silent_linux - If set then linux will be told to boot silently, by
4937 changing the console to be empty. If "yes" it will be
4938 made silent. If "no" it will not be made silent. If
4939 unset, then it will be made silent if the U-Boot console
4942 tftpsrcport - If this is set, the value is used for TFTP's
4945 tftpdstport - If this is set, the value is used for TFTP's UDP
4946 destination port instead of the Well Know Port 69.
4948 tftpblocksize - Block size to use for TFTP transfers; if not set,
4949 we use the TFTP server's default block size
4951 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4952 seconds, minimum value is 1000 = 1 second). Defines
4953 when a packet is considered to be lost so it has to
4954 be retransmitted. The default is 5000 = 5 seconds.
4955 Lowering this value may make downloads succeed
4956 faster in networks with high packet loss rates or
4957 with unreliable TFTP servers.
4959 vlan - When set to a value < 4095 the traffic over
4960 Ethernet is encapsulated/received over 802.1q
4963 The following image location variables contain the location of images
4964 used in booting. The "Image" column gives the role of the image and is
4965 not an environment variable name. The other columns are environment
4966 variable names. "File Name" gives the name of the file on a TFTP
4967 server, "RAM Address" gives the location in RAM the image will be
4968 loaded to, and "Flash Location" gives the image's address in NOR
4969 flash or offset in NAND flash.
4971 *Note* - these variables don't have to be defined for all boards, some
4972 boards currenlty use other variables for these purposes, and some
4973 boards use these variables for other purposes.
4975 Image File Name RAM Address Flash Location
4976 ----- --------- ----------- --------------
4977 u-boot u-boot u-boot_addr_r u-boot_addr
4978 Linux kernel bootfile kernel_addr_r kernel_addr
4979 device tree blob fdtfile fdt_addr_r fdt_addr
4980 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4982 The following environment variables may be used and automatically
4983 updated by the network boot commands ("bootp" and "rarpboot"),
4984 depending the information provided by your boot server:
4986 bootfile - see above
4987 dnsip - IP address of your Domain Name Server
4988 dnsip2 - IP address of your secondary Domain Name Server
4989 gatewayip - IP address of the Gateway (Router) to use
4990 hostname - Target hostname
4992 netmask - Subnet Mask
4993 rootpath - Pathname of the root filesystem on the NFS server
4994 serverip - see above
4997 There are two special Environment Variables:
4999 serial# - contains hardware identification information such
5000 as type string and/or serial number
5001 ethaddr - Ethernet address
5003 These variables can be set only once (usually during manufacturing of
5004 the board). U-Boot refuses to delete or overwrite these variables
5005 once they have been set once.
5008 Further special Environment Variables:
5010 ver - Contains the U-Boot version string as printed
5011 with the "version" command. This variable is
5012 readonly (see CONFIG_VERSION_VARIABLE).
5015 Please note that changes to some configuration parameters may take
5016 only effect after the next boot (yes, that's just like Windoze :-).
5019 Callback functions for environment variables:
5020 ---------------------------------------------
5022 For some environment variables, the behavior of u-boot needs to change
5023 when their values are changed. This functionailty allows functions to
5024 be associated with arbitrary variables. On creation, overwrite, or
5025 deletion, the callback will provide the opportunity for some side
5026 effect to happen or for the change to be rejected.
5028 The callbacks are named and associated with a function using the
5029 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5031 These callbacks are associated with variables in one of two ways. The
5032 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5033 in the board configuration to a string that defines a list of
5034 associations. The list must be in the following format:
5036 entry = variable_name[:callback_name]
5039 If the callback name is not specified, then the callback is deleted.
5040 Spaces are also allowed anywhere in the list.
5042 Callbacks can also be associated by defining the ".callbacks" variable
5043 with the same list format above. Any association in ".callbacks" will
5044 override any association in the static list. You can define
5045 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5046 ".callbacks" envirnoment variable in the default or embedded environment.
5049 Command Line Parsing:
5050 =====================
5052 There are two different command line parsers available with U-Boot:
5053 the old "simple" one, and the much more powerful "hush" shell:
5055 Old, simple command line parser:
5056 --------------------------------
5058 - supports environment variables (through setenv / saveenv commands)
5059 - several commands on one line, separated by ';'
5060 - variable substitution using "... ${name} ..." syntax
5061 - special characters ('$', ';') can be escaped by prefixing with '\',
5063 setenv bootcmd bootm \${address}
5064 - You can also escape text by enclosing in single apostrophes, for example:
5065 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5070 - similar to Bourne shell, with control structures like
5071 if...then...else...fi, for...do...done; while...do...done,
5072 until...do...done, ...
5073 - supports environment ("global") variables (through setenv / saveenv
5074 commands) and local shell variables (through standard shell syntax
5075 "name=value"); only environment variables can be used with "run"
5081 (1) If a command line (or an environment variable executed by a "run"
5082 command) contains several commands separated by semicolon, and
5083 one of these commands fails, then the remaining commands will be
5086 (2) If you execute several variables with one call to run (i. e.
5087 calling run with a list of variables as arguments), any failing
5088 command will cause "run" to terminate, i. e. the remaining
5089 variables are not executed.
5091 Note for Redundant Ethernet Interfaces:
5092 =======================================
5094 Some boards come with redundant Ethernet interfaces; U-Boot supports
5095 such configurations and is capable of automatic selection of a
5096 "working" interface when needed. MAC assignment works as follows:
5098 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5099 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5100 "eth1addr" (=>eth1), "eth2addr", ...
5102 If the network interface stores some valid MAC address (for instance
5103 in SROM), this is used as default address if there is NO correspon-
5104 ding setting in the environment; if the corresponding environment
5105 variable is set, this overrides the settings in the card; that means:
5107 o If the SROM has a valid MAC address, and there is no address in the
5108 environment, the SROM's address is used.
5110 o If there is no valid address in the SROM, and a definition in the
5111 environment exists, then the value from the environment variable is
5114 o If both the SROM and the environment contain a MAC address, and
5115 both addresses are the same, this MAC address is used.
5117 o If both the SROM and the environment contain a MAC address, and the
5118 addresses differ, the value from the environment is used and a
5121 o If neither SROM nor the environment contain a MAC address, an error
5124 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5125 will be programmed into hardware as part of the initialization process. This
5126 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5127 The naming convention is as follows:
5128 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5133 U-Boot is capable of booting (and performing other auxiliary operations on)
5134 images in two formats:
5136 New uImage format (FIT)
5137 -----------------------
5139 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5140 to Flattened Device Tree). It allows the use of images with multiple
5141 components (several kernels, ramdisks, etc.), with contents protected by
5142 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5148 Old image format is based on binary files which can be basically anything,
5149 preceded by a special header; see the definitions in include/image.h for
5150 details; basically, the header defines the following image properties:
5152 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5153 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5154 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5155 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5157 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5158 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5159 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5160 * Compression Type (uncompressed, gzip, bzip2)
5166 The header is marked by a special Magic Number, and both the header
5167 and the data portions of the image are secured against corruption by
5174 Although U-Boot should support any OS or standalone application
5175 easily, the main focus has always been on Linux during the design of
5178 U-Boot includes many features that so far have been part of some
5179 special "boot loader" code within the Linux kernel. Also, any
5180 "initrd" images to be used are no longer part of one big Linux image;
5181 instead, kernel and "initrd" are separate images. This implementation
5182 serves several purposes:
5184 - the same features can be used for other OS or standalone
5185 applications (for instance: using compressed images to reduce the
5186 Flash memory footprint)
5188 - it becomes much easier to port new Linux kernel versions because
5189 lots of low-level, hardware dependent stuff are done by U-Boot
5191 - the same Linux kernel image can now be used with different "initrd"
5192 images; of course this also means that different kernel images can
5193 be run with the same "initrd". This makes testing easier (you don't
5194 have to build a new "zImage.initrd" Linux image when you just
5195 change a file in your "initrd"). Also, a field-upgrade of the
5196 software is easier now.
5202 Porting Linux to U-Boot based systems:
5203 ---------------------------------------
5205 U-Boot cannot save you from doing all the necessary modifications to
5206 configure the Linux device drivers for use with your target hardware
5207 (no, we don't intend to provide a full virtual machine interface to
5210 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5212 Just make sure your machine specific header file (for instance
5213 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5214 Information structure as we define in include/asm-<arch>/u-boot.h,
5215 and make sure that your definition of IMAP_ADDR uses the same value
5216 as your U-Boot configuration in CONFIG_SYS_IMMR.
5219 Configuring the Linux kernel:
5220 -----------------------------
5222 No specific requirements for U-Boot. Make sure you have some root
5223 device (initial ramdisk, NFS) for your target system.
5226 Building a Linux Image:
5227 -----------------------
5229 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5230 not used. If you use recent kernel source, a new build target
5231 "uImage" will exist which automatically builds an image usable by
5232 U-Boot. Most older kernels also have support for a "pImage" target,
5233 which was introduced for our predecessor project PPCBoot and uses a
5234 100% compatible format.
5243 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5244 encapsulate a compressed Linux kernel image with header information,
5245 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5247 * build a standard "vmlinux" kernel image (in ELF binary format):
5249 * convert the kernel into a raw binary image:
5251 ${CROSS_COMPILE}-objcopy -O binary \
5252 -R .note -R .comment \
5253 -S vmlinux linux.bin
5255 * compress the binary image:
5259 * package compressed binary image for U-Boot:
5261 mkimage -A ppc -O linux -T kernel -C gzip \
5262 -a 0 -e 0 -n "Linux Kernel Image" \
5263 -d linux.bin.gz uImage
5266 The "mkimage" tool can also be used to create ramdisk images for use
5267 with U-Boot, either separated from the Linux kernel image, or
5268 combined into one file. "mkimage" encapsulates the images with a 64
5269 byte header containing information about target architecture,
5270 operating system, image type, compression method, entry points, time
5271 stamp, CRC32 checksums, etc.
5273 "mkimage" can be called in two ways: to verify existing images and
5274 print the header information, or to build new images.
5276 In the first form (with "-l" option) mkimage lists the information
5277 contained in the header of an existing U-Boot image; this includes
5278 checksum verification:
5280 tools/mkimage -l image
5281 -l ==> list image header information
5283 The second form (with "-d" option) is used to build a U-Boot image
5284 from a "data file" which is used as image payload:
5286 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5287 -n name -d data_file image
5288 -A ==> set architecture to 'arch'
5289 -O ==> set operating system to 'os'
5290 -T ==> set image type to 'type'
5291 -C ==> set compression type 'comp'
5292 -a ==> set load address to 'addr' (hex)
5293 -e ==> set entry point to 'ep' (hex)
5294 -n ==> set image name to 'name'
5295 -d ==> use image data from 'datafile'
5297 Right now, all Linux kernels for PowerPC systems use the same load
5298 address (0x00000000), but the entry point address depends on the
5301 - 2.2.x kernels have the entry point at 0x0000000C,
5302 - 2.3.x and later kernels have the entry point at 0x00000000.
5304 So a typical call to build a U-Boot image would read:
5306 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5307 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5308 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5309 > examples/uImage.TQM850L
5310 Image Name: 2.4.4 kernel for TQM850L
5311 Created: Wed Jul 19 02:34:59 2000
5312 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5313 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5314 Load Address: 0x00000000
5315 Entry Point: 0x00000000
5317 To verify the contents of the image (or check for corruption):
5319 -> tools/mkimage -l examples/uImage.TQM850L
5320 Image Name: 2.4.4 kernel for TQM850L
5321 Created: Wed Jul 19 02:34:59 2000
5322 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5323 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5324 Load Address: 0x00000000
5325 Entry Point: 0x00000000
5327 NOTE: for embedded systems where boot time is critical you can trade
5328 speed for memory and install an UNCOMPRESSED image instead: this
5329 needs more space in Flash, but boots much faster since it does not
5330 need to be uncompressed:
5332 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5333 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5334 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5335 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5336 > examples/uImage.TQM850L-uncompressed
5337 Image Name: 2.4.4 kernel for TQM850L
5338 Created: Wed Jul 19 02:34:59 2000
5339 Image Type: PowerPC Linux Kernel Image (uncompressed)
5340 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5341 Load Address: 0x00000000
5342 Entry Point: 0x00000000
5345 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5346 when your kernel is intended to use an initial ramdisk:
5348 -> tools/mkimage -n 'Simple Ramdisk Image' \
5349 > -A ppc -O linux -T ramdisk -C gzip \
5350 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5351 Image Name: Simple Ramdisk Image
5352 Created: Wed Jan 12 14:01:50 2000
5353 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5354 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5355 Load Address: 0x00000000
5356 Entry Point: 0x00000000
5358 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5359 option performs the converse operation of the mkimage's second form (the "-d"
5360 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5363 tools/dumpimage -i image -p position data_file
5364 -i ==> extract from the 'image' a specific 'data_file', \
5365 indexed by 'position'
5368 Installing a Linux Image:
5369 -------------------------
5371 To downloading a U-Boot image over the serial (console) interface,
5372 you must convert the image to S-Record format:
5374 objcopy -I binary -O srec examples/image examples/image.srec
5376 The 'objcopy' does not understand the information in the U-Boot
5377 image header, so the resulting S-Record file will be relative to
5378 address 0x00000000. To load it to a given address, you need to
5379 specify the target address as 'offset' parameter with the 'loads'
5382 Example: install the image to address 0x40100000 (which on the
5383 TQM8xxL is in the first Flash bank):
5385 => erase 40100000 401FFFFF
5391 ## Ready for S-Record download ...
5392 ~>examples/image.srec
5393 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5395 15989 15990 15991 15992
5396 [file transfer complete]
5398 ## Start Addr = 0x00000000
5401 You can check the success of the download using the 'iminfo' command;
5402 this includes a checksum verification so you can be sure no data
5403 corruption happened:
5407 ## Checking Image at 40100000 ...
5408 Image Name: 2.2.13 for initrd on TQM850L
5409 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5410 Data Size: 335725 Bytes = 327 kB = 0 MB
5411 Load Address: 00000000
5412 Entry Point: 0000000c
5413 Verifying Checksum ... OK
5419 The "bootm" command is used to boot an application that is stored in
5420 memory (RAM or Flash). In case of a Linux kernel image, the contents
5421 of the "bootargs" environment variable is passed to the kernel as
5422 parameters. You can check and modify this variable using the
5423 "printenv" and "setenv" commands:
5426 => printenv bootargs
5427 bootargs=root=/dev/ram
5429 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5431 => printenv bootargs
5432 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5435 ## Booting Linux kernel at 40020000 ...
5436 Image Name: 2.2.13 for NFS on TQM850L
5437 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5438 Data Size: 381681 Bytes = 372 kB = 0 MB
5439 Load Address: 00000000
5440 Entry Point: 0000000c
5441 Verifying Checksum ... OK
5442 Uncompressing Kernel Image ... OK
5443 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
5444 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5445 time_init: decrementer frequency = 187500000/60
5446 Calibrating delay loop... 49.77 BogoMIPS
5447 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5450 If you want to boot a Linux kernel with initial RAM disk, you pass
5451 the memory addresses of both the kernel and the initrd image (PPBCOOT
5452 format!) to the "bootm" command:
5454 => imi 40100000 40200000
5456 ## Checking Image at 40100000 ...
5457 Image Name: 2.2.13 for initrd on TQM850L
5458 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5459 Data Size: 335725 Bytes = 327 kB = 0 MB
5460 Load Address: 00000000
5461 Entry Point: 0000000c
5462 Verifying Checksum ... OK
5464 ## Checking Image at 40200000 ...
5465 Image Name: Simple Ramdisk Image
5466 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5467 Data Size: 566530 Bytes = 553 kB = 0 MB
5468 Load Address: 00000000
5469 Entry Point: 00000000
5470 Verifying Checksum ... OK
5472 => bootm 40100000 40200000
5473 ## Booting Linux kernel at 40100000 ...
5474 Image Name: 2.2.13 for initrd on TQM850L
5475 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5476 Data Size: 335725 Bytes = 327 kB = 0 MB
5477 Load Address: 00000000
5478 Entry Point: 0000000c
5479 Verifying Checksum ... OK
5480 Uncompressing Kernel Image ... OK
5481 ## Loading RAMDisk Image at 40200000 ...
5482 Image Name: Simple Ramdisk Image
5483 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5484 Data Size: 566530 Bytes = 553 kB = 0 MB
5485 Load Address: 00000000
5486 Entry Point: 00000000
5487 Verifying Checksum ... OK
5488 Loading Ramdisk ... OK
5489 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
5490 Boot arguments: root=/dev/ram
5491 time_init: decrementer frequency = 187500000/60
5492 Calibrating delay loop... 49.77 BogoMIPS
5494 RAMDISK: Compressed image found at block 0
5495 VFS: Mounted root (ext2 filesystem).
5499 Boot Linux and pass a flat device tree:
5502 First, U-Boot must be compiled with the appropriate defines. See the section
5503 titled "Linux Kernel Interface" above for a more in depth explanation. The
5504 following is an example of how to start a kernel and pass an updated
5510 oft=oftrees/mpc8540ads.dtb
5511 => tftp $oftaddr $oft
5512 Speed: 1000, full duplex
5514 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5515 Filename 'oftrees/mpc8540ads.dtb'.
5516 Load address: 0x300000
5519 Bytes transferred = 4106 (100a hex)
5520 => tftp $loadaddr $bootfile
5521 Speed: 1000, full duplex
5523 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5525 Load address: 0x200000
5526 Loading:############
5528 Bytes transferred = 1029407 (fb51f hex)
5533 => bootm $loadaddr - $oftaddr
5534 ## Booting image at 00200000 ...
5535 Image Name: Linux-2.6.17-dirty
5536 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5537 Data Size: 1029343 Bytes = 1005.2 kB
5538 Load Address: 00000000
5539 Entry Point: 00000000
5540 Verifying Checksum ... OK
5541 Uncompressing Kernel Image ... OK
5542 Booting using flat device tree at 0x300000
5543 Using MPC85xx ADS machine description
5544 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5548 More About U-Boot Image Types:
5549 ------------------------------
5551 U-Boot supports the following image types:
5553 "Standalone Programs" are directly runnable in the environment
5554 provided by U-Boot; it is expected that (if they behave
5555 well) you can continue to work in U-Boot after return from
5556 the Standalone Program.
5557 "OS Kernel Images" are usually images of some Embedded OS which
5558 will take over control completely. Usually these programs
5559 will install their own set of exception handlers, device
5560 drivers, set up the MMU, etc. - this means, that you cannot
5561 expect to re-enter U-Boot except by resetting the CPU.
5562 "RAMDisk Images" are more or less just data blocks, and their
5563 parameters (address, size) are passed to an OS kernel that is
5565 "Multi-File Images" contain several images, typically an OS
5566 (Linux) kernel image and one or more data images like
5567 RAMDisks. This construct is useful for instance when you want
5568 to boot over the network using BOOTP etc., where the boot
5569 server provides just a single image file, but you want to get
5570 for instance an OS kernel and a RAMDisk image.
5572 "Multi-File Images" start with a list of image sizes, each
5573 image size (in bytes) specified by an "uint32_t" in network
5574 byte order. This list is terminated by an "(uint32_t)0".
5575 Immediately after the terminating 0 follow the images, one by
5576 one, all aligned on "uint32_t" boundaries (size rounded up to
5577 a multiple of 4 bytes).
5579 "Firmware Images" are binary images containing firmware (like
5580 U-Boot or FPGA images) which usually will be programmed to
5583 "Script files" are command sequences that will be executed by
5584 U-Boot's command interpreter; this feature is especially
5585 useful when you configure U-Boot to use a real shell (hush)
5586 as command interpreter.
5588 Booting the Linux zImage:
5589 -------------------------
5591 On some platforms, it's possible to boot Linux zImage. This is done
5592 using the "bootz" command. The syntax of "bootz" command is the same
5593 as the syntax of "bootm" command.
5595 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5596 kernel with raw initrd images. The syntax is slightly different, the
5597 address of the initrd must be augmented by it's size, in the following
5598 format: "<initrd addres>:<initrd size>".
5604 One of the features of U-Boot is that you can dynamically load and
5605 run "standalone" applications, which can use some resources of
5606 U-Boot like console I/O functions or interrupt services.
5608 Two simple examples are included with the sources:
5613 'examples/hello_world.c' contains a small "Hello World" Demo
5614 application; it is automatically compiled when you build U-Boot.
5615 It's configured to run at address 0x00040004, so you can play with it
5619 ## Ready for S-Record download ...
5620 ~>examples/hello_world.srec
5621 1 2 3 4 5 6 7 8 9 10 11 ...
5622 [file transfer complete]
5624 ## Start Addr = 0x00040004
5626 => go 40004 Hello World! This is a test.
5627 ## Starting application at 0x00040004 ...
5638 Hit any key to exit ...
5640 ## Application terminated, rc = 0x0
5642 Another example, which demonstrates how to register a CPM interrupt
5643 handler with the U-Boot code, can be found in 'examples/timer.c'.
5644 Here, a CPM timer is set up to generate an interrupt every second.
5645 The interrupt service routine is trivial, just printing a '.'
5646 character, but this is just a demo program. The application can be
5647 controlled by the following keys:
5649 ? - print current values og the CPM Timer registers
5650 b - enable interrupts and start timer
5651 e - stop timer and disable interrupts
5652 q - quit application
5655 ## Ready for S-Record download ...
5656 ~>examples/timer.srec
5657 1 2 3 4 5 6 7 8 9 10 11 ...
5658 [file transfer complete]
5660 ## Start Addr = 0x00040004
5663 ## Starting application at 0x00040004 ...
5666 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5669 [q, b, e, ?] Set interval 1000000 us
5672 [q, b, e, ?] ........
5673 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5676 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5679 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5682 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5684 [q, b, e, ?] ...Stopping timer
5686 [q, b, e, ?] ## Application terminated, rc = 0x0
5692 Over time, many people have reported problems when trying to use the
5693 "minicom" terminal emulation program for serial download. I (wd)
5694 consider minicom to be broken, and recommend not to use it. Under
5695 Unix, I recommend to use C-Kermit for general purpose use (and
5696 especially for kermit binary protocol download ("loadb" command), and
5697 use "cu" for S-Record download ("loads" command). See
5698 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5699 for help with kermit.
5702 Nevertheless, if you absolutely want to use it try adding this
5703 configuration to your "File transfer protocols" section:
5705 Name Program Name U/D FullScr IO-Red. Multi
5706 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5707 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5713 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5714 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5716 Building requires a cross environment; it is known to work on
5717 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5718 need gmake since the Makefiles are not compatible with BSD make).
5719 Note that the cross-powerpc package does not install include files;
5720 attempting to build U-Boot will fail because <machine/ansi.h> is
5721 missing. This file has to be installed and patched manually:
5723 # cd /usr/pkg/cross/powerpc-netbsd/include
5725 # ln -s powerpc machine
5726 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5727 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5729 Native builds *don't* work due to incompatibilities between native
5730 and U-Boot include files.
5732 Booting assumes that (the first part of) the image booted is a
5733 stage-2 loader which in turn loads and then invokes the kernel
5734 proper. Loader sources will eventually appear in the NetBSD source
5735 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5736 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5739 Implementation Internals:
5740 =========================
5742 The following is not intended to be a complete description of every
5743 implementation detail. However, it should help to understand the
5744 inner workings of U-Boot and make it easier to port it to custom
5748 Initial Stack, Global Data:
5749 ---------------------------
5751 The implementation of U-Boot is complicated by the fact that U-Boot
5752 starts running out of ROM (flash memory), usually without access to
5753 system RAM (because the memory controller is not initialized yet).
5754 This means that we don't have writable Data or BSS segments, and BSS
5755 is not initialized as zero. To be able to get a C environment working
5756 at all, we have to allocate at least a minimal stack. Implementation
5757 options for this are defined and restricted by the CPU used: Some CPU
5758 models provide on-chip memory (like the IMMR area on MPC8xx and
5759 MPC826x processors), on others (parts of) the data cache can be
5760 locked as (mis-) used as memory, etc.
5762 Chris Hallinan posted a good summary of these issues to the
5763 U-Boot mailing list:
5765 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5766 From: "Chris Hallinan" <clh@net1plus.com>
5767 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5770 Correct me if I'm wrong, folks, but the way I understand it
5771 is this: Using DCACHE as initial RAM for Stack, etc, does not
5772 require any physical RAM backing up the cache. The cleverness
5773 is that the cache is being used as a temporary supply of
5774 necessary storage before the SDRAM controller is setup. It's
5775 beyond the scope of this list to explain the details, but you
5776 can see how this works by studying the cache architecture and
5777 operation in the architecture and processor-specific manuals.
5779 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5780 is another option for the system designer to use as an
5781 initial stack/RAM area prior to SDRAM being available. Either
5782 option should work for you. Using CS 4 should be fine if your
5783 board designers haven't used it for something that would
5784 cause you grief during the initial boot! It is frequently not
5787 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5788 with your processor/board/system design. The default value
5789 you will find in any recent u-boot distribution in
5790 walnut.h should work for you. I'd set it to a value larger
5791 than your SDRAM module. If you have a 64MB SDRAM module, set
5792 it above 400_0000. Just make sure your board has no resources
5793 that are supposed to respond to that address! That code in
5794 start.S has been around a while and should work as is when
5795 you get the config right.
5800 It is essential to remember this, since it has some impact on the C
5801 code for the initialization procedures:
5803 * Initialized global data (data segment) is read-only. Do not attempt
5806 * Do not use any uninitialized global data (or implicitely initialized
5807 as zero data - BSS segment) at all - this is undefined, initiali-
5808 zation is performed later (when relocating to RAM).
5810 * Stack space is very limited. Avoid big data buffers or things like
5813 Having only the stack as writable memory limits means we cannot use
5814 normal global data to share information beween the code. But it
5815 turned out that the implementation of U-Boot can be greatly
5816 simplified by making a global data structure (gd_t) available to all
5817 functions. We could pass a pointer to this data as argument to _all_
5818 functions, but this would bloat the code. Instead we use a feature of
5819 the GCC compiler (Global Register Variables) to share the data: we
5820 place a pointer (gd) to the global data into a register which we
5821 reserve for this purpose.
5823 When choosing a register for such a purpose we are restricted by the
5824 relevant (E)ABI specifications for the current architecture, and by
5825 GCC's implementation.
5827 For PowerPC, the following registers have specific use:
5829 R2: reserved for system use
5830 R3-R4: parameter passing and return values
5831 R5-R10: parameter passing
5832 R13: small data area pointer
5836 (U-Boot also uses R12 as internal GOT pointer. r12
5837 is a volatile register so r12 needs to be reset when
5838 going back and forth between asm and C)
5840 ==> U-Boot will use R2 to hold a pointer to the global data
5842 Note: on PPC, we could use a static initializer (since the
5843 address of the global data structure is known at compile time),
5844 but it turned out that reserving a register results in somewhat
5845 smaller code - although the code savings are not that big (on
5846 average for all boards 752 bytes for the whole U-Boot image,
5847 624 text + 127 data).
5849 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5850 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5852 ==> U-Boot will use P3 to hold a pointer to the global data
5854 On ARM, the following registers are used:
5856 R0: function argument word/integer result
5857 R1-R3: function argument word
5858 R9: platform specific
5859 R10: stack limit (used only if stack checking is enabled)
5860 R11: argument (frame) pointer
5861 R12: temporary workspace
5864 R15: program counter
5866 ==> U-Boot will use R9 to hold a pointer to the global data
5868 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5870 On Nios II, the ABI is documented here:
5871 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5873 ==> U-Boot will use gp to hold a pointer to the global data
5875 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5876 to access small data sections, so gp is free.
5878 On NDS32, the following registers are used:
5880 R0-R1: argument/return
5882 R15: temporary register for assembler
5883 R16: trampoline register
5884 R28: frame pointer (FP)
5885 R29: global pointer (GP)
5886 R30: link register (LP)
5887 R31: stack pointer (SP)
5888 PC: program counter (PC)
5890 ==> U-Boot will use R10 to hold a pointer to the global data
5892 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5893 or current versions of GCC may "optimize" the code too much.
5898 U-Boot runs in system state and uses physical addresses, i.e. the
5899 MMU is not used either for address mapping nor for memory protection.
5901 The available memory is mapped to fixed addresses using the memory
5902 controller. In this process, a contiguous block is formed for each
5903 memory type (Flash, SDRAM, SRAM), even when it consists of several
5904 physical memory banks.
5906 U-Boot is installed in the first 128 kB of the first Flash bank (on
5907 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5908 booting and sizing and initializing DRAM, the code relocates itself
5909 to the upper end of DRAM. Immediately below the U-Boot code some
5910 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5911 configuration setting]. Below that, a structure with global Board
5912 Info data is placed, followed by the stack (growing downward).
5914 Additionally, some exception handler code is copied to the low 8 kB
5915 of DRAM (0x00000000 ... 0x00001FFF).
5917 So a typical memory configuration with 16 MB of DRAM could look like
5920 0x0000 0000 Exception Vector code
5923 0x0000 2000 Free for Application Use
5929 0x00FB FF20 Monitor Stack (Growing downward)
5930 0x00FB FFAC Board Info Data and permanent copy of global data
5931 0x00FC 0000 Malloc Arena
5934 0x00FE 0000 RAM Copy of Monitor Code
5935 ... eventually: LCD or video framebuffer
5936 ... eventually: pRAM (Protected RAM - unchanged by reset)
5937 0x00FF FFFF [End of RAM]
5940 System Initialization:
5941 ----------------------
5943 In the reset configuration, U-Boot starts at the reset entry point
5944 (on most PowerPC systems at address 0x00000100). Because of the reset
5945 configuration for CS0# this is a mirror of the onboard Flash memory.
5946 To be able to re-map memory U-Boot then jumps to its link address.
5947 To be able to implement the initialization code in C, a (small!)
5948 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5949 which provide such a feature like MPC8xx or MPC8260), or in a locked
5950 part of the data cache. After that, U-Boot initializes the CPU core,
5951 the caches and the SIU.
5953 Next, all (potentially) available memory banks are mapped using a
5954 preliminary mapping. For example, we put them on 512 MB boundaries
5955 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5956 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5957 programmed for SDRAM access. Using the temporary configuration, a
5958 simple memory test is run that determines the size of the SDRAM
5961 When there is more than one SDRAM bank, and the banks are of
5962 different size, the largest is mapped first. For equal size, the first
5963 bank (CS2#) is mapped first. The first mapping is always for address
5964 0x00000000, with any additional banks following immediately to create
5965 contiguous memory starting from 0.
5967 Then, the monitor installs itself at the upper end of the SDRAM area
5968 and allocates memory for use by malloc() and for the global Board
5969 Info data; also, the exception vector code is copied to the low RAM
5970 pages, and the final stack is set up.
5972 Only after this relocation will you have a "normal" C environment;
5973 until that you are restricted in several ways, mostly because you are
5974 running from ROM, and because the code will have to be relocated to a
5978 U-Boot Porting Guide:
5979 ----------------------
5981 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5985 int main(int argc, char *argv[])
5987 sighandler_t no_more_time;
5989 signal(SIGALRM, no_more_time);
5990 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5992 if (available_money > available_manpower) {
5993 Pay consultant to port U-Boot;
5997 Download latest U-Boot source;
5999 Subscribe to u-boot mailing list;
6002 email("Hi, I am new to U-Boot, how do I get started?");
6005 Read the README file in the top level directory;
6006 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6007 Read applicable doc/*.README;
6008 Read the source, Luke;
6009 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6012 if (available_money > toLocalCurrency ($2500))
6015 Add a lot of aggravation and time;
6017 if (a similar board exists) { /* hopefully... */
6018 cp -a board/<similar> board/<myboard>
6019 cp include/configs/<similar>.h include/configs/<myboard>.h
6021 Create your own board support subdirectory;
6022 Create your own board include/configs/<myboard>.h file;
6024 Edit new board/<myboard> files
6025 Edit new include/configs/<myboard>.h
6030 Add / modify source code;
6034 email("Hi, I am having problems...");
6036 Send patch file to the U-Boot email list;
6037 if (reasonable critiques)
6038 Incorporate improvements from email list code review;
6040 Defend code as written;
6046 void no_more_time (int sig)
6055 All contributions to U-Boot should conform to the Linux kernel
6056 coding style; see the file "Documentation/CodingStyle" and the script
6057 "scripts/Lindent" in your Linux kernel source directory.
6059 Source files originating from a different project (for example the
6060 MTD subsystem) are generally exempt from these guidelines and are not
6061 reformated to ease subsequent migration to newer versions of those
6064 Please note that U-Boot is implemented in C (and to some small parts in
6065 Assembler); no C++ is used, so please do not use C++ style comments (//)
6068 Please also stick to the following formatting rules:
6069 - remove any trailing white space
6070 - use TAB characters for indentation and vertical alignment, not spaces
6071 - make sure NOT to use DOS '\r\n' line feeds
6072 - do not add more than 2 consecutive empty lines to source files
6073 - do not add trailing empty lines to source files
6075 Submissions which do not conform to the standards may be returned
6076 with a request to reformat the changes.
6082 Since the number of patches for U-Boot is growing, we need to
6083 establish some rules. Submissions which do not conform to these rules
6084 may be rejected, even when they contain important and valuable stuff.
6086 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6088 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6089 see http://lists.denx.de/mailman/listinfo/u-boot
6091 When you send a patch, please include the following information with
6094 * For bug fixes: a description of the bug and how your patch fixes
6095 this bug. Please try to include a way of demonstrating that the
6096 patch actually fixes something.
6098 * For new features: a description of the feature and your
6101 * A CHANGELOG entry as plaintext (separate from the patch)
6103 * For major contributions, your entry to the CREDITS file
6105 * When you add support for a new board, don't forget to add a
6106 maintainer e-mail address to the boards.cfg file, too.
6108 * If your patch adds new configuration options, don't forget to
6109 document these in the README file.
6111 * The patch itself. If you are using git (which is *strongly*
6112 recommended) you can easily generate the patch using the
6113 "git format-patch". If you then use "git send-email" to send it to
6114 the U-Boot mailing list, you will avoid most of the common problems
6115 with some other mail clients.
6117 If you cannot use git, use "diff -purN OLD NEW". If your version of
6118 diff does not support these options, then get the latest version of
6121 The current directory when running this command shall be the parent
6122 directory of the U-Boot source tree (i. e. please make sure that
6123 your patch includes sufficient directory information for the
6126 We prefer patches as plain text. MIME attachments are discouraged,
6127 and compressed attachments must not be used.
6129 * If one logical set of modifications affects or creates several
6130 files, all these changes shall be submitted in a SINGLE patch file.
6132 * Changesets that contain different, unrelated modifications shall be
6133 submitted as SEPARATE patches, one patch per changeset.
6138 * Before sending the patch, run the MAKEALL script on your patched
6139 source tree and make sure that no errors or warnings are reported
6140 for any of the boards.
6142 * Keep your modifications to the necessary minimum: A patch
6143 containing several unrelated changes or arbitrary reformats will be
6144 returned with a request to re-formatting / split it.
6146 * If you modify existing code, make sure that your new code does not
6147 add to the memory footprint of the code ;-) Small is beautiful!
6148 When adding new features, these should compile conditionally only
6149 (using #ifdef), and the resulting code with the new feature
6150 disabled must not need more memory than the old code without your
6153 * Remember that there is a size limit of 100 kB per message on the
6154 u-boot mailing list. Bigger patches will be moderated. If they are
6155 reasonable and not too big, they will be acknowledged. But patches
6156 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob