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_NAND_BASE
3336 Include nand_base.c in the SPL. Requires
3337 CONFIG_SPL_NAND_DRIVERS.
3339 CONFIG_SPL_NAND_DRIVERS
3340 SPL uses normal NAND drivers, not minimal drivers.
3343 Include standard software ECC in the SPL
3345 CONFIG_SPL_NAND_SIMPLE
3346 Support for NAND boot using simple NAND drivers that
3347 expose the cmd_ctrl() interface.
3349 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3350 Set for the SPL on PPC mpc8xxx targets, support for
3351 drivers/ddr/fsl/libddr.o in SPL binary.
3353 CONFIG_SPL_COMMON_INIT_DDR
3354 Set for common ddr init with serial presence detect in
3357 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3358 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3359 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3360 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3361 CONFIG_SYS_NAND_ECCBYTES
3362 Defines the size and behavior of the NAND that SPL uses
3365 CONFIG_SPL_NAND_BOOT
3366 Add support NAND boot
3368 CONFIG_SYS_NAND_U_BOOT_OFFS
3369 Location in NAND to read U-Boot from
3371 CONFIG_SYS_NAND_U_BOOT_DST
3372 Location in memory to load U-Boot to
3374 CONFIG_SYS_NAND_U_BOOT_SIZE
3375 Size of image to load
3377 CONFIG_SYS_NAND_U_BOOT_START
3378 Entry point in loaded image to jump to
3380 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3381 Define this if you need to first read the OOB and then the
3382 data. This is used for example on davinci plattforms.
3384 CONFIG_SPL_OMAP3_ID_NAND
3385 Support for an OMAP3-specific set of functions to return the
3386 ID and MFR of the first attached NAND chip, if present.
3388 CONFIG_SPL_SERIAL_SUPPORT
3389 Support for drivers/serial/libserial.o in SPL binary
3391 CONFIG_SPL_SPI_FLASH_SUPPORT
3392 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3394 CONFIG_SPL_SPI_SUPPORT
3395 Support for drivers/spi/libspi.o in SPL binary
3397 CONFIG_SPL_RAM_DEVICE
3398 Support for running image already present in ram, in SPL binary
3400 CONFIG_SPL_LIBGENERIC_SUPPORT
3401 Support for lib/libgeneric.o in SPL binary
3403 CONFIG_SPL_ENV_SUPPORT
3404 Support for the environment operating in SPL binary
3406 CONFIG_SPL_NET_SUPPORT
3407 Support for the net/libnet.o in SPL binary.
3408 It conflicts with SPL env from storage medium specified by
3409 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3412 Image offset to which the SPL should be padded before appending
3413 the SPL payload. By default, this is defined as
3414 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3415 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3416 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3419 Final target image containing SPL and payload. Some SPLs
3420 use an arch-specific makefile fragment instead, for
3421 example if more than one image needs to be produced.
3423 CONFIG_FIT_SPL_PRINT
3424 Printing information about a FIT image adds quite a bit of
3425 code to SPL. So this is normally disabled in SPL. Use this
3426 option to re-enable it. This will affect the output of the
3427 bootm command when booting a FIT image.
3431 Enable building of TPL globally.
3434 Image offset to which the TPL should be padded before appending
3435 the TPL payload. By default, this is defined as
3436 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3437 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3438 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3443 [so far only for SMDK2400 boards]
3445 - Modem support enable:
3446 CONFIG_MODEM_SUPPORT
3448 - RTS/CTS Flow control enable:
3451 - Modem debug support:
3452 CONFIG_MODEM_SUPPORT_DEBUG
3454 Enables debugging stuff (char screen[1024], dbg())
3455 for modem support. Useful only with BDI2000.
3457 - Interrupt support (PPC):
3459 There are common interrupt_init() and timer_interrupt()
3460 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3461 for CPU specific initialization. interrupt_init_cpu()
3462 should set decrementer_count to appropriate value. If
3463 CPU resets decrementer automatically after interrupt
3464 (ppc4xx) it should set decrementer_count to zero.
3465 timer_interrupt() calls timer_interrupt_cpu() for CPU
3466 specific handling. If board has watchdog / status_led
3467 / other_activity_monitor it works automatically from
3468 general timer_interrupt().
3472 In the target system modem support is enabled when a
3473 specific key (key combination) is pressed during
3474 power-on. Otherwise U-Boot will boot normally
3475 (autoboot). The key_pressed() function is called from
3476 board_init(). Currently key_pressed() is a dummy
3477 function, returning 1 and thus enabling modem
3480 If there are no modem init strings in the
3481 environment, U-Boot proceed to autoboot; the
3482 previous output (banner, info printfs) will be
3485 See also: doc/README.Modem
3487 Board initialization settings:
3488 ------------------------------
3490 During Initialization u-boot calls a number of board specific functions
3491 to allow the preparation of board specific prerequisites, e.g. pin setup
3492 before drivers are initialized. To enable these callbacks the
3493 following configuration macros have to be defined. Currently this is
3494 architecture specific, so please check arch/your_architecture/lib/board.c
3495 typically in board_init_f() and board_init_r().
3497 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3498 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3499 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3500 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3502 Configuration Settings:
3503 -----------------------
3505 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3506 Optionally it can be defined to support 64-bit memory commands.
3508 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3509 undefine this when you're short of memory.
3511 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3512 width of the commands listed in the 'help' command output.
3514 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3515 prompt for user input.
3517 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3519 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3521 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3523 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3524 the application (usually a Linux kernel) when it is
3527 - CONFIG_SYS_BAUDRATE_TABLE:
3528 List of legal baudrate settings for this board.
3530 - CONFIG_SYS_CONSOLE_INFO_QUIET
3531 Suppress display of console information at boot.
3533 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3534 If the board specific function
3535 extern int overwrite_console (void);
3536 returns 1, the stdin, stderr and stdout are switched to the
3537 serial port, else the settings in the environment are used.
3539 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3540 Enable the call to overwrite_console().
3542 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3543 Enable overwrite of previous console environment settings.
3545 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3546 Begin and End addresses of the area used by the
3549 - CONFIG_SYS_ALT_MEMTEST:
3550 Enable an alternate, more extensive memory test.
3552 - CONFIG_SYS_MEMTEST_SCRATCH:
3553 Scratch address used by the alternate memory test
3554 You only need to set this if address zero isn't writeable
3556 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3557 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3558 this specified memory area will get subtracted from the top
3559 (end) of RAM and won't get "touched" at all by U-Boot. By
3560 fixing up gd->ram_size the Linux kernel should gets passed
3561 the now "corrected" memory size and won't touch it either.
3562 This should work for arch/ppc and arch/powerpc. Only Linux
3563 board ports in arch/powerpc with bootwrapper support that
3564 recalculate the memory size from the SDRAM controller setup
3565 will have to get fixed in Linux additionally.
3567 This option can be used as a workaround for the 440EPx/GRx
3568 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3571 WARNING: Please make sure that this value is a multiple of
3572 the Linux page size (normally 4k). If this is not the case,
3573 then the end address of the Linux memory will be located at a
3574 non page size aligned address and this could cause major
3577 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3578 Enable temporary baudrate change while serial download
3580 - CONFIG_SYS_SDRAM_BASE:
3581 Physical start address of SDRAM. _Must_ be 0 here.
3583 - CONFIG_SYS_MBIO_BASE:
3584 Physical start address of Motherboard I/O (if using a
3587 - CONFIG_SYS_FLASH_BASE:
3588 Physical start address of Flash memory.
3590 - CONFIG_SYS_MONITOR_BASE:
3591 Physical start address of boot monitor code (set by
3592 make config files to be same as the text base address
3593 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3594 CONFIG_SYS_FLASH_BASE when booting from flash.
3596 - CONFIG_SYS_MONITOR_LEN:
3597 Size of memory reserved for monitor code, used to
3598 determine _at_compile_time_ (!) if the environment is
3599 embedded within the U-Boot image, or in a separate
3602 - CONFIG_SYS_MALLOC_LEN:
3603 Size of DRAM reserved for malloc() use.
3605 - CONFIG_SYS_BOOTM_LEN:
3606 Normally compressed uImages are limited to an
3607 uncompressed size of 8 MBytes. If this is not enough,
3608 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3609 to adjust this setting to your needs.
3611 - CONFIG_SYS_BOOTMAPSZ:
3612 Maximum size of memory mapped by the startup code of
3613 the Linux kernel; all data that must be processed by
3614 the Linux kernel (bd_info, boot arguments, FDT blob if
3615 used) must be put below this limit, unless "bootm_low"
3616 environment variable is defined and non-zero. In such case
3617 all data for the Linux kernel must be between "bootm_low"
3618 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3619 variable "bootm_mapsize" will override the value of
3620 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3621 then the value in "bootm_size" will be used instead.
3623 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3624 Enable initrd_high functionality. If defined then the
3625 initrd_high feature is enabled and the bootm ramdisk subcommand
3628 - CONFIG_SYS_BOOT_GET_CMDLINE:
3629 Enables allocating and saving kernel cmdline in space between
3630 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3632 - CONFIG_SYS_BOOT_GET_KBD:
3633 Enables allocating and saving a kernel copy of the bd_info in
3634 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3636 - CONFIG_SYS_MAX_FLASH_BANKS:
3637 Max number of Flash memory banks
3639 - CONFIG_SYS_MAX_FLASH_SECT:
3640 Max number of sectors on a Flash chip
3642 - CONFIG_SYS_FLASH_ERASE_TOUT:
3643 Timeout for Flash erase operations (in ms)
3645 - CONFIG_SYS_FLASH_WRITE_TOUT:
3646 Timeout for Flash write operations (in ms)
3648 - CONFIG_SYS_FLASH_LOCK_TOUT
3649 Timeout for Flash set sector lock bit operation (in ms)
3651 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3652 Timeout for Flash clear lock bits operation (in ms)
3654 - CONFIG_SYS_FLASH_PROTECTION
3655 If defined, hardware flash sectors protection is used
3656 instead of U-Boot software protection.
3658 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3660 Enable TFTP transfers directly to flash memory;
3661 without this option such a download has to be
3662 performed in two steps: (1) download to RAM, and (2)
3663 copy from RAM to flash.
3665 The two-step approach is usually more reliable, since
3666 you can check if the download worked before you erase
3667 the flash, but in some situations (when system RAM is
3668 too limited to allow for a temporary copy of the
3669 downloaded image) this option may be very useful.
3671 - CONFIG_SYS_FLASH_CFI:
3672 Define if the flash driver uses extra elements in the
3673 common flash structure for storing flash geometry.
3675 - CONFIG_FLASH_CFI_DRIVER
3676 This option also enables the building of the cfi_flash driver
3677 in the drivers directory
3679 - CONFIG_FLASH_CFI_MTD
3680 This option enables the building of the cfi_mtd driver
3681 in the drivers directory. The driver exports CFI flash
3684 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3685 Use buffered writes to flash.
3687 - CONFIG_FLASH_SPANSION_S29WS_N
3688 s29ws-n MirrorBit flash has non-standard addresses for buffered
3691 - CONFIG_SYS_FLASH_QUIET_TEST
3692 If this option is defined, the common CFI flash doesn't
3693 print it's warning upon not recognized FLASH banks. This
3694 is useful, if some of the configured banks are only
3695 optionally available.
3697 - CONFIG_FLASH_SHOW_PROGRESS
3698 If defined (must be an integer), print out countdown
3699 digits and dots. Recommended value: 45 (9..1) for 80
3700 column displays, 15 (3..1) for 40 column displays.
3702 - CONFIG_FLASH_VERIFY
3703 If defined, the content of the flash (destination) is compared
3704 against the source after the write operation. An error message
3705 will be printed when the contents are not identical.
3706 Please note that this option is useless in nearly all cases,
3707 since such flash programming errors usually are detected earlier
3708 while unprotecting/erasing/programming. Please only enable
3709 this option if you really know what you are doing.
3711 - CONFIG_SYS_RX_ETH_BUFFER:
3712 Defines the number of Ethernet receive buffers. On some
3713 Ethernet controllers it is recommended to set this value
3714 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3715 buffers can be full shortly after enabling the interface
3716 on high Ethernet traffic.
3717 Defaults to 4 if not defined.
3719 - CONFIG_ENV_MAX_ENTRIES
3721 Maximum number of entries in the hash table that is used
3722 internally to store the environment settings. The default
3723 setting is supposed to be generous and should work in most
3724 cases. This setting can be used to tune behaviour; see
3725 lib/hashtable.c for details.
3727 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3728 - CONFIG_ENV_FLAGS_LIST_STATIC
3729 Enable validation of the values given to environment variables when
3730 calling env set. Variables can be restricted to only decimal,
3731 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3732 the variables can also be restricted to IP address or MAC address.
3734 The format of the list is:
3735 type_attribute = [s|d|x|b|i|m]
3736 access_atribute = [a|r|o|c]
3737 attributes = type_attribute[access_atribute]
3738 entry = variable_name[:attributes]
3741 The type attributes are:
3742 s - String (default)
3745 b - Boolean ([1yYtT|0nNfF])
3749 The access attributes are:
3755 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3756 Define this to a list (string) to define the ".flags"
3757 envirnoment variable in the default or embedded environment.
3759 - CONFIG_ENV_FLAGS_LIST_STATIC
3760 Define this to a list (string) to define validation that
3761 should be done if an entry is not found in the ".flags"
3762 environment variable. To override a setting in the static
3763 list, simply add an entry for the same variable name to the
3766 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3767 If defined, don't allow the -f switch to env set override variable
3770 - CONFIG_SYS_GENERIC_BOARD
3771 This selects the architecture-generic board system instead of the
3772 architecture-specific board files. It is intended to move boards
3773 to this new framework over time. Defining this will disable the
3774 arch/foo/lib/board.c file and use common/board_f.c and
3775 common/board_r.c instead. To use this option your architecture
3776 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3777 its config.mk file). If you find problems enabling this option on
3778 your board please report the problem and send patches!
3780 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3781 This is set by OMAP boards for the max time that reset should
3782 be asserted. See doc/README.omap-reset-time for details on how
3783 the value can be calulated on a given board.
3785 The following definitions that deal with the placement and management
3786 of environment data (variable area); in general, we support the
3787 following configurations:
3789 - CONFIG_BUILD_ENVCRC:
3791 Builds up envcrc with the target environment so that external utils
3792 may easily extract it and embed it in final U-Boot images.
3794 - CONFIG_ENV_IS_IN_FLASH:
3796 Define this if the environment is in flash memory.
3798 a) The environment occupies one whole flash sector, which is
3799 "embedded" in the text segment with the U-Boot code. This
3800 happens usually with "bottom boot sector" or "top boot
3801 sector" type flash chips, which have several smaller
3802 sectors at the start or the end. For instance, such a
3803 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3804 such a case you would place the environment in one of the
3805 4 kB sectors - with U-Boot code before and after it. With
3806 "top boot sector" type flash chips, you would put the
3807 environment in one of the last sectors, leaving a gap
3808 between U-Boot and the environment.
3810 - CONFIG_ENV_OFFSET:
3812 Offset of environment data (variable area) to the
3813 beginning of flash memory; for instance, with bottom boot
3814 type flash chips the second sector can be used: the offset
3815 for this sector is given here.
3817 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3821 This is just another way to specify the start address of
3822 the flash sector containing the environment (instead of
3825 - CONFIG_ENV_SECT_SIZE:
3827 Size of the sector containing the environment.
3830 b) Sometimes flash chips have few, equal sized, BIG sectors.
3831 In such a case you don't want to spend a whole sector for
3836 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3837 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3838 of this flash sector for the environment. This saves
3839 memory for the RAM copy of the environment.
3841 It may also save flash memory if you decide to use this
3842 when your environment is "embedded" within U-Boot code,
3843 since then the remainder of the flash sector could be used
3844 for U-Boot code. It should be pointed out that this is
3845 STRONGLY DISCOURAGED from a robustness point of view:
3846 updating the environment in flash makes it always
3847 necessary to erase the WHOLE sector. If something goes
3848 wrong before the contents has been restored from a copy in
3849 RAM, your target system will be dead.
3851 - CONFIG_ENV_ADDR_REDUND
3852 CONFIG_ENV_SIZE_REDUND
3854 These settings describe a second storage area used to hold
3855 a redundant copy of the environment data, so that there is
3856 a valid backup copy in case there is a power failure during
3857 a "saveenv" operation.
3859 BE CAREFUL! Any changes to the flash layout, and some changes to the
3860 source code will make it necessary to adapt <board>/u-boot.lds*
3864 - CONFIG_ENV_IS_IN_NVRAM:
3866 Define this if you have some non-volatile memory device
3867 (NVRAM, battery buffered SRAM) which you want to use for the
3873 These two #defines are used to determine the memory area you
3874 want to use for environment. It is assumed that this memory
3875 can just be read and written to, without any special
3878 BE CAREFUL! The first access to the environment happens quite early
3879 in U-Boot initalization (when we try to get the setting of for the
3880 console baudrate). You *MUST* have mapped your NVRAM area then, or
3883 Please note that even with NVRAM we still use a copy of the
3884 environment in RAM: we could work on NVRAM directly, but we want to
3885 keep settings there always unmodified except somebody uses "saveenv"
3886 to save the current settings.
3889 - CONFIG_ENV_IS_IN_EEPROM:
3891 Use this if you have an EEPROM or similar serial access
3892 device and a driver for it.
3894 - CONFIG_ENV_OFFSET:
3897 These two #defines specify the offset and size of the
3898 environment area within the total memory of your EEPROM.
3900 - CONFIG_SYS_I2C_EEPROM_ADDR:
3901 If defined, specified the chip address of the EEPROM device.
3902 The default address is zero.
3904 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3905 If defined, the number of bits used to address bytes in a
3906 single page in the EEPROM device. A 64 byte page, for example
3907 would require six bits.
3909 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3910 If defined, the number of milliseconds to delay between
3911 page writes. The default is zero milliseconds.
3913 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3914 The length in bytes of the EEPROM memory array address. Note
3915 that this is NOT the chip address length!
3917 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3918 EEPROM chips that implement "address overflow" are ones
3919 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3920 address and the extra bits end up in the "chip address" bit
3921 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3924 Note that we consider the length of the address field to
3925 still be one byte because the extra address bits are hidden
3926 in the chip address.
3928 - CONFIG_SYS_EEPROM_SIZE:
3929 The size in bytes of the EEPROM device.
3931 - CONFIG_ENV_EEPROM_IS_ON_I2C
3932 define this, if you have I2C and SPI activated, and your
3933 EEPROM, which holds the environment, is on the I2C bus.
3935 - CONFIG_I2C_ENV_EEPROM_BUS
3936 if you have an Environment on an EEPROM reached over
3937 I2C muxes, you can define here, how to reach this
3938 EEPROM. For example:
3940 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3942 EEPROM which holds the environment, is reached over
3943 a pca9547 i2c mux with address 0x70, channel 3.
3945 - CONFIG_ENV_IS_IN_DATAFLASH:
3947 Define this if you have a DataFlash memory device which you
3948 want to use for the environment.
3950 - CONFIG_ENV_OFFSET:
3954 These three #defines specify the offset and size of the
3955 environment area within the total memory of your DataFlash placed
3956 at the specified address.
3958 - CONFIG_ENV_IS_IN_REMOTE:
3960 Define this if you have a remote memory space which you
3961 want to use for the local device's environment.
3966 These two #defines specify the address and size of the
3967 environment area within the remote memory space. The
3968 local device can get the environment from remote memory
3969 space by SRIO or PCIE links.
3971 BE CAREFUL! For some special cases, the local device can not use
3972 "saveenv" command. For example, the local device will get the
3973 environment stored in a remote NOR flash by SRIO or PCIE link,
3974 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3976 - CONFIG_ENV_IS_IN_NAND:
3978 Define this if you have a NAND device which you want to use
3979 for the environment.
3981 - CONFIG_ENV_OFFSET:
3984 These two #defines specify the offset and size of the environment
3985 area within the first NAND device. CONFIG_ENV_OFFSET must be
3986 aligned to an erase block boundary.
3988 - CONFIG_ENV_OFFSET_REDUND (optional):
3990 This setting describes a second storage area of CONFIG_ENV_SIZE
3991 size used to hold a redundant copy of the environment data, so
3992 that there is a valid backup copy in case there is a power failure
3993 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3994 aligned to an erase block boundary.
3996 - CONFIG_ENV_RANGE (optional):
3998 Specifies the length of the region in which the environment
3999 can be written. This should be a multiple of the NAND device's
4000 block size. Specifying a range with more erase blocks than
4001 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
4002 the range to be avoided.
4004 - CONFIG_ENV_OFFSET_OOB (optional):
4006 Enables support for dynamically retrieving the offset of the
4007 environment from block zero's out-of-band data. The
4008 "nand env.oob" command can be used to record this offset.
4009 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
4010 using CONFIG_ENV_OFFSET_OOB.
4012 - CONFIG_NAND_ENV_DST
4014 Defines address in RAM to which the nand_spl code should copy the
4015 environment. If redundant environment is used, it will be copied to
4016 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
4018 - CONFIG_ENV_IS_IN_UBI:
4020 Define this if you have an UBI volume that you want to use for the
4021 environment. This has the benefit of wear-leveling the environment
4022 accesses, which is important on NAND.
4024 - CONFIG_ENV_UBI_PART:
4026 Define this to a string that is the mtd partition containing the UBI.
4028 - CONFIG_ENV_UBI_VOLUME:
4030 Define this to the name of the volume that you want to store the
4033 - CONFIG_ENV_UBI_VOLUME_REDUND:
4035 Define this to the name of another volume to store a second copy of
4036 the environment in. This will enable redundant environments in UBI.
4037 It is assumed that both volumes are in the same MTD partition.
4039 - CONFIG_UBI_SILENCE_MSG
4040 - CONFIG_UBIFS_SILENCE_MSG
4042 You will probably want to define these to avoid a really noisy system
4043 when storing the env in UBI.
4045 - CONFIG_ENV_IS_IN_MMC:
4047 Define this if you have an MMC device which you want to use for the
4050 - CONFIG_SYS_MMC_ENV_DEV:
4052 Specifies which MMC device the environment is stored in.
4054 - CONFIG_SYS_MMC_ENV_PART (optional):
4056 Specifies which MMC partition the environment is stored in. If not
4057 set, defaults to partition 0, the user area. Common values might be
4058 1 (first MMC boot partition), 2 (second MMC boot partition).
4060 - CONFIG_ENV_OFFSET:
4063 These two #defines specify the offset and size of the environment
4064 area within the specified MMC device.
4066 If offset is positive (the usual case), it is treated as relative to
4067 the start of the MMC partition. If offset is negative, it is treated
4068 as relative to the end of the MMC partition. This can be useful if
4069 your board may be fitted with different MMC devices, which have
4070 different sizes for the MMC partitions, and you always want the
4071 environment placed at the very end of the partition, to leave the
4072 maximum possible space before it, to store other data.
4074 These two values are in units of bytes, but must be aligned to an
4075 MMC sector boundary.
4077 - CONFIG_ENV_OFFSET_REDUND (optional):
4079 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4080 hold a redundant copy of the environment data. This provides a
4081 valid backup copy in case the other copy is corrupted, e.g. due
4082 to a power failure during a "saveenv" operation.
4084 This value may also be positive or negative; this is handled in the
4085 same way as CONFIG_ENV_OFFSET.
4087 This value is also in units of bytes, but must also be aligned to
4088 an MMC sector boundary.
4090 - CONFIG_ENV_SIZE_REDUND (optional):
4092 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4093 set. If this value is set, it must be set to the same value as
4096 - CONFIG_SYS_SPI_INIT_OFFSET
4098 Defines offset to the initial SPI buffer area in DPRAM. The
4099 area is used at an early stage (ROM part) if the environment
4100 is configured to reside in the SPI EEPROM: We need a 520 byte
4101 scratch DPRAM area. It is used between the two initialization
4102 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4103 to be a good choice since it makes it far enough from the
4104 start of the data area as well as from the stack pointer.
4106 Please note that the environment is read-only until the monitor
4107 has been relocated to RAM and a RAM copy of the environment has been
4108 created; also, when using EEPROM you will have to use getenv_f()
4109 until then to read environment variables.
4111 The environment is protected by a CRC32 checksum. Before the monitor
4112 is relocated into RAM, as a result of a bad CRC you will be working
4113 with the compiled-in default environment - *silently*!!! [This is
4114 necessary, because the first environment variable we need is the
4115 "baudrate" setting for the console - if we have a bad CRC, we don't
4116 have any device yet where we could complain.]
4118 Note: once the monitor has been relocated, then it will complain if
4119 the default environment is used; a new CRC is computed as soon as you
4120 use the "saveenv" command to store a valid environment.
4122 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4123 Echo the inverted Ethernet link state to the fault LED.
4125 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4126 also needs to be defined.
4128 - CONFIG_SYS_FAULT_MII_ADDR:
4129 MII address of the PHY to check for the Ethernet link state.
4131 - CONFIG_NS16550_MIN_FUNCTIONS:
4132 Define this if you desire to only have use of the NS16550_init
4133 and NS16550_putc functions for the serial driver located at
4134 drivers/serial/ns16550.c. This option is useful for saving
4135 space for already greatly restricted images, including but not
4136 limited to NAND_SPL configurations.
4138 - CONFIG_DISPLAY_BOARDINFO
4139 Display information about the board that U-Boot is running on
4140 when U-Boot starts up. The board function checkboard() is called
4143 - CONFIG_DISPLAY_BOARDINFO_LATE
4144 Similar to the previous option, but display this information
4145 later, once stdio is running and output goes to the LCD, if
4148 Low Level (hardware related) configuration options:
4149 ---------------------------------------------------
4151 - CONFIG_SYS_CACHELINE_SIZE:
4152 Cache Line Size of the CPU.
4154 - CONFIG_SYS_DEFAULT_IMMR:
4155 Default address of the IMMR after system reset.
4157 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4158 and RPXsuper) to be able to adjust the position of
4159 the IMMR register after a reset.
4161 - CONFIG_SYS_CCSRBAR_DEFAULT:
4162 Default (power-on reset) physical address of CCSR on Freescale
4165 - CONFIG_SYS_CCSRBAR:
4166 Virtual address of CCSR. On a 32-bit build, this is typically
4167 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4169 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4170 for cross-platform code that uses that macro instead.
4172 - CONFIG_SYS_CCSRBAR_PHYS:
4173 Physical address of CCSR. CCSR can be relocated to a new
4174 physical address, if desired. In this case, this macro should
4175 be set to that address. Otherwise, it should be set to the
4176 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4177 is typically relocated on 36-bit builds. It is recommended
4178 that this macro be defined via the _HIGH and _LOW macros:
4180 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4181 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4183 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4184 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4185 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4186 used in assembly code, so it must not contain typecasts or
4187 integer size suffixes (e.g. "ULL").
4189 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4190 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4191 used in assembly code, so it must not contain typecasts or
4192 integer size suffixes (e.g. "ULL").
4194 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4195 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4196 forced to a value that ensures that CCSR is not relocated.
4198 - Floppy Disk Support:
4199 CONFIG_SYS_FDC_DRIVE_NUMBER
4201 the default drive number (default value 0)
4203 CONFIG_SYS_ISA_IO_STRIDE
4205 defines the spacing between FDC chipset registers
4208 CONFIG_SYS_ISA_IO_OFFSET
4210 defines the offset of register from address. It
4211 depends on which part of the data bus is connected to
4212 the FDC chipset. (default value 0)
4214 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4215 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4218 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4219 fdc_hw_init() is called at the beginning of the FDC
4220 setup. fdc_hw_init() must be provided by the board
4221 source code. It is used to make hardware dependant
4225 Most IDE controllers were designed to be connected with PCI
4226 interface. Only few of them were designed for AHB interface.
4227 When software is doing ATA command and data transfer to
4228 IDE devices through IDE-AHB controller, some additional
4229 registers accessing to these kind of IDE-AHB controller
4232 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4233 DO NOT CHANGE unless you know exactly what you're
4234 doing! (11-4) [MPC8xx/82xx systems only]
4236 - CONFIG_SYS_INIT_RAM_ADDR:
4238 Start address of memory area that can be used for
4239 initial data and stack; please note that this must be
4240 writable memory that is working WITHOUT special
4241 initialization, i. e. you CANNOT use normal RAM which
4242 will become available only after programming the
4243 memory controller and running certain initialization
4246 U-Boot uses the following memory types:
4247 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4248 - MPC824X: data cache
4249 - PPC4xx: data cache
4251 - CONFIG_SYS_GBL_DATA_OFFSET:
4253 Offset of the initial data structure in the memory
4254 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4255 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4256 data is located at the end of the available space
4257 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4258 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4259 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4260 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4263 On the MPC824X (or other systems that use the data
4264 cache for initial memory) the address chosen for
4265 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4266 point to an otherwise UNUSED address space between
4267 the top of RAM and the start of the PCI space.
4269 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4271 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4273 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4275 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4277 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4279 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4281 - CONFIG_SYS_OR_TIMING_SDRAM:
4284 - CONFIG_SYS_MAMR_PTA:
4285 periodic timer for refresh
4287 - CONFIG_SYS_DER: Debug Event Register (37-47)
4289 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4290 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4291 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4292 CONFIG_SYS_BR1_PRELIM:
4293 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4295 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4296 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4297 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4298 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4300 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4301 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4302 Machine Mode Register and Memory Periodic Timer
4303 Prescaler definitions (SDRAM timing)
4305 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4306 enable I2C microcode relocation patch (MPC8xx);
4307 define relocation offset in DPRAM [DSP2]
4309 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4310 enable SMC microcode relocation patch (MPC8xx);
4311 define relocation offset in DPRAM [SMC1]
4313 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4314 enable SPI microcode relocation patch (MPC8xx);
4315 define relocation offset in DPRAM [SCC4]
4317 - CONFIG_SYS_USE_OSCCLK:
4318 Use OSCM clock mode on MBX8xx board. Be careful,
4319 wrong setting might damage your board. Read
4320 doc/README.MBX before setting this variable!
4322 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4323 Offset of the bootmode word in DPRAM used by post
4324 (Power On Self Tests). This definition overrides
4325 #define'd default value in commproc.h resp.
4328 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4329 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4330 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4331 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4332 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4333 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4334 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4335 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4336 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4338 - CONFIG_PCI_DISABLE_PCIE:
4339 Disable PCI-Express on systems where it is supported but not
4342 - CONFIG_PCI_ENUM_ONLY
4343 Only scan through and get the devices on the busses.
4344 Don't do any setup work, presumably because someone or
4345 something has already done it, and we don't need to do it
4346 a second time. Useful for platforms that are pre-booted
4347 by coreboot or similar.
4349 - CONFIG_PCI_INDIRECT_BRIDGE:
4350 Enable support for indirect PCI bridges.
4353 Chip has SRIO or not
4356 Board has SRIO 1 port available
4359 Board has SRIO 2 port available
4361 - CONFIG_SRIO_PCIE_BOOT_MASTER
4362 Board can support master function for Boot from SRIO and PCIE
4364 - CONFIG_SYS_SRIOn_MEM_VIRT:
4365 Virtual Address of SRIO port 'n' memory region
4367 - CONFIG_SYS_SRIOn_MEM_PHYS:
4368 Physical Address of SRIO port 'n' memory region
4370 - CONFIG_SYS_SRIOn_MEM_SIZE:
4371 Size of SRIO port 'n' memory region
4373 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4374 Defined to tell the NAND controller that the NAND chip is using
4376 Not all NAND drivers use this symbol.
4377 Example of drivers that use it:
4378 - drivers/mtd/nand/ndfc.c
4379 - drivers/mtd/nand/mxc_nand.c
4381 - CONFIG_SYS_NDFC_EBC0_CFG
4382 Sets the EBC0_CFG register for the NDFC. If not defined
4383 a default value will be used.
4386 Get DDR timing information from an I2C EEPROM. Common
4387 with pluggable memory modules such as SODIMMs
4390 I2C address of the SPD EEPROM
4392 - CONFIG_SYS_SPD_BUS_NUM
4393 If SPD EEPROM is on an I2C bus other than the first
4394 one, specify here. Note that the value must resolve
4395 to something your driver can deal with.
4397 - CONFIG_SYS_DDR_RAW_TIMING
4398 Get DDR timing information from other than SPD. Common with
4399 soldered DDR chips onboard without SPD. DDR raw timing
4400 parameters are extracted from datasheet and hard-coded into
4401 header files or board specific files.
4403 - CONFIG_FSL_DDR_INTERACTIVE
4404 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4406 - CONFIG_SYS_83XX_DDR_USES_CS0
4407 Only for 83xx systems. If specified, then DDR should
4408 be configured using CS0 and CS1 instead of CS2 and CS3.
4410 - CONFIG_ETHER_ON_FEC[12]
4411 Define to enable FEC[12] on a 8xx series processor.
4413 - CONFIG_FEC[12]_PHY
4414 Define to the hardcoded PHY address which corresponds
4415 to the given FEC; i. e.
4416 #define CONFIG_FEC1_PHY 4
4417 means that the PHY with address 4 is connected to FEC1
4419 When set to -1, means to probe for first available.
4421 - CONFIG_FEC[12]_PHY_NORXERR
4422 The PHY does not have a RXERR line (RMII only).
4423 (so program the FEC to ignore it).
4426 Enable RMII mode for all FECs.
4427 Note that this is a global option, we can't
4428 have one FEC in standard MII mode and another in RMII mode.
4430 - CONFIG_CRC32_VERIFY
4431 Add a verify option to the crc32 command.
4434 => crc32 -v <address> <count> <crc32>
4436 Where address/count indicate a memory area
4437 and crc32 is the correct crc32 which the
4441 Add the "loopw" memory command. This only takes effect if
4442 the memory commands are activated globally (CONFIG_CMD_MEM).
4445 Add the "mdc" and "mwc" memory commands. These are cyclic
4450 This command will print 4 bytes (10,11,12,13) each 500 ms.
4452 => mwc.l 100 12345678 10
4453 This command will write 12345678 to address 100 all 10 ms.
4455 This only takes effect if the memory commands are activated
4456 globally (CONFIG_CMD_MEM).
4458 - CONFIG_SKIP_LOWLEVEL_INIT
4459 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4460 low level initializations (like setting up the memory
4461 controller) are omitted and/or U-Boot does not
4462 relocate itself into RAM.
4464 Normally this variable MUST NOT be defined. The only
4465 exception is when U-Boot is loaded (to RAM) by some
4466 other boot loader or by a debugger which performs
4467 these initializations itself.
4470 Modifies the behaviour of start.S when compiling a loader
4471 that is executed before the actual U-Boot. E.g. when
4472 compiling a NAND SPL.
4475 Modifies the behaviour of start.S when compiling a loader
4476 that is executed after the SPL and before the actual U-Boot.
4477 It is loaded by the SPL.
4479 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4480 Only for 85xx systems. If this variable is specified, the section
4481 .resetvec is not kept and the section .bootpg is placed in the
4482 previous 4k of the .text section.
4484 - CONFIG_ARCH_MAP_SYSMEM
4485 Generally U-Boot (and in particular the md command) uses
4486 effective address. It is therefore not necessary to regard
4487 U-Boot address as virtual addresses that need to be translated
4488 to physical addresses. However, sandbox requires this, since
4489 it maintains its own little RAM buffer which contains all
4490 addressable memory. This option causes some memory accesses
4491 to be mapped through map_sysmem() / unmap_sysmem().
4493 - CONFIG_USE_ARCH_MEMCPY
4494 CONFIG_USE_ARCH_MEMSET
4495 If these options are used a optimized version of memcpy/memset will
4496 be used if available. These functions may be faster under some
4497 conditions but may increase the binary size.
4499 - CONFIG_X86_RESET_VECTOR
4500 If defined, the x86 reset vector code is included. This is not
4501 needed when U-Boot is running from Coreboot.
4504 Defines the MPU clock speed (in MHz).
4506 NOTE : currently only supported on AM335x platforms.
4508 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4509 Enables the RTC32K OSC on AM33xx based plattforms
4511 Freescale QE/FMAN Firmware Support:
4512 -----------------------------------
4514 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4515 loading of "firmware", which is encoded in the QE firmware binary format.
4516 This firmware often needs to be loaded during U-Boot booting, so macros
4517 are used to identify the storage device (NOR flash, SPI, etc) and the address
4520 - CONFIG_SYS_FMAN_FW_ADDR
4521 The address in the storage device where the FMAN microcode is located. The
4522 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4525 - CONFIG_SYS_QE_FW_ADDR
4526 The address in the storage device where the QE microcode is located. The
4527 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4530 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4531 The maximum possible size of the firmware. The firmware binary format
4532 has a field that specifies the actual size of the firmware, but it
4533 might not be possible to read any part of the firmware unless some
4534 local storage is allocated to hold the entire firmware first.
4536 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4537 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4538 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4539 virtual address in NOR flash.
4541 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4542 Specifies that QE/FMAN firmware is located in NAND flash.
4543 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4545 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4546 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4547 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4549 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4550 Specifies that QE/FMAN firmware is located on the primary SPI
4551 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4553 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4554 Specifies that QE/FMAN firmware is located in the remote (master)
4555 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4556 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4557 window->master inbound window->master LAW->the ucode address in
4558 master's memory space.
4560 Building the Software:
4561 ======================
4563 Building U-Boot has been tested in several native build environments
4564 and in many different cross environments. Of course we cannot support
4565 all possibly existing versions of cross development tools in all
4566 (potentially obsolete) versions. In case of tool chain problems we
4567 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4568 which is extensively used to build and test U-Boot.
4570 If you are not using a native environment, it is assumed that you
4571 have GNU cross compiling tools available in your path. In this case,
4572 you must set the environment variable CROSS_COMPILE in your shell.
4573 Note that no changes to the Makefile or any other source files are
4574 necessary. For example using the ELDK on a 4xx CPU, please enter:
4576 $ CROSS_COMPILE=ppc_4xx-
4577 $ export CROSS_COMPILE
4579 Note: If you wish to generate Windows versions of the utilities in
4580 the tools directory you can use the MinGW toolchain
4581 (http://www.mingw.org). Set your HOST tools to the MinGW
4582 toolchain and execute 'make tools'. For example:
4584 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4586 Binaries such as tools/mkimage.exe will be created which can
4587 be executed on computers running Windows.
4589 U-Boot is intended to be simple to build. After installing the
4590 sources you must configure U-Boot for one specific board type. This
4595 where "NAME_config" is the name of one of the existing configu-
4596 rations; see boards.cfg for supported names.
4598 Note: for some board special configuration names may exist; check if
4599 additional information is available from the board vendor; for
4600 instance, the TQM823L systems are available without (standard)
4601 or with LCD support. You can select such additional "features"
4602 when choosing the configuration, i. e.
4605 - will configure for a plain TQM823L, i. e. no LCD support
4607 make TQM823L_LCD_config
4608 - will configure for a TQM823L with U-Boot console on LCD
4613 Finally, type "make all", and you should get some working U-Boot
4614 images ready for download to / installation on your system:
4616 - "u-boot.bin" is a raw binary image
4617 - "u-boot" is an image in ELF binary format
4618 - "u-boot.srec" is in Motorola S-Record format
4620 By default the build is performed locally and the objects are saved
4621 in the source directory. One of the two methods can be used to change
4622 this behavior and build U-Boot to some external directory:
4624 1. Add O= to the make command line invocations:
4626 make O=/tmp/build distclean
4627 make O=/tmp/build NAME_config
4628 make O=/tmp/build all
4630 2. Set environment variable BUILD_DIR to point to the desired location:
4632 export BUILD_DIR=/tmp/build
4637 Note that the command line "O=" setting overrides the BUILD_DIR environment
4641 Please be aware that the Makefiles assume you are using GNU make, so
4642 for instance on NetBSD you might need to use "gmake" instead of
4646 If the system board that you have is not listed, then you will need
4647 to port U-Boot to your hardware platform. To do this, follow these
4650 1. Add a new configuration option for your board to the toplevel
4651 "boards.cfg" file, using the existing entries as examples.
4652 Follow the instructions there to keep the boards in order.
4653 2. Create a new directory to hold your board specific code. Add any
4654 files you need. In your board directory, you will need at least
4655 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4656 3. Create a new configuration file "include/configs/<board>.h" for
4658 3. If you're porting U-Boot to a new CPU, then also create a new
4659 directory to hold your CPU specific code. Add any files you need.
4660 4. Run "make <board>_config" with your new name.
4661 5. Type "make", and you should get a working "u-boot.srec" file
4662 to be installed on your target system.
4663 6. Debug and solve any problems that might arise.
4664 [Of course, this last step is much harder than it sounds.]
4667 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4668 ==============================================================
4670 If you have modified U-Boot sources (for instance added a new board
4671 or support for new devices, a new CPU, etc.) you are expected to
4672 provide feedback to the other developers. The feedback normally takes
4673 the form of a "patch", i. e. a context diff against a certain (latest
4674 official or latest in the git repository) version of U-Boot sources.
4676 But before you submit such a patch, please verify that your modifi-
4677 cation did not break existing code. At least make sure that *ALL* of
4678 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4679 just run the "MAKEALL" script, which will configure and build U-Boot
4680 for ALL supported system. Be warned, this will take a while. You can
4681 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4682 environment variable to the script, i. e. to use the ELDK cross tools
4685 CROSS_COMPILE=ppc_8xx- MAKEALL
4687 or to build on a native PowerPC system you can type
4689 CROSS_COMPILE=' ' MAKEALL
4691 When using the MAKEALL script, the default behaviour is to build
4692 U-Boot in the source directory. This location can be changed by
4693 setting the BUILD_DIR environment variable. Also, for each target
4694 built, the MAKEALL script saves two log files (<target>.ERR and
4695 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4696 location can be changed by setting the MAKEALL_LOGDIR environment
4697 variable. For example:
4699 export BUILD_DIR=/tmp/build
4700 export MAKEALL_LOGDIR=/tmp/log
4701 CROSS_COMPILE=ppc_8xx- MAKEALL
4703 With the above settings build objects are saved in the /tmp/build,
4704 log files are saved in the /tmp/log and the source tree remains clean
4705 during the whole build process.
4708 See also "U-Boot Porting Guide" below.
4711 Monitor Commands - Overview:
4712 ============================
4714 go - start application at address 'addr'
4715 run - run commands in an environment variable
4716 bootm - boot application image from memory
4717 bootp - boot image via network using BootP/TFTP protocol
4718 bootz - boot zImage from memory
4719 tftpboot- boot image via network using TFTP protocol
4720 and env variables "ipaddr" and "serverip"
4721 (and eventually "gatewayip")
4722 tftpput - upload a file via network using TFTP protocol
4723 rarpboot- boot image via network using RARP/TFTP protocol
4724 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4725 loads - load S-Record file over serial line
4726 loadb - load binary file over serial line (kermit mode)
4728 mm - memory modify (auto-incrementing)
4729 nm - memory modify (constant address)
4730 mw - memory write (fill)
4732 cmp - memory compare
4733 crc32 - checksum calculation
4734 i2c - I2C sub-system
4735 sspi - SPI utility commands
4736 base - print or set address offset
4737 printenv- print environment variables
4738 setenv - set environment variables
4739 saveenv - save environment variables to persistent storage
4740 protect - enable or disable FLASH write protection
4741 erase - erase FLASH memory
4742 flinfo - print FLASH memory information
4743 nand - NAND memory operations (see doc/README.nand)
4744 bdinfo - print Board Info structure
4745 iminfo - print header information for application image
4746 coninfo - print console devices and informations
4747 ide - IDE sub-system
4748 loop - infinite loop on address range
4749 loopw - infinite write loop on address range
4750 mtest - simple RAM test
4751 icache - enable or disable instruction cache
4752 dcache - enable or disable data cache
4753 reset - Perform RESET of the CPU
4754 echo - echo args to console
4755 version - print monitor version
4756 help - print online help
4757 ? - alias for 'help'
4760 Monitor Commands - Detailed Description:
4761 ========================================
4765 For now: just type "help <command>".
4768 Environment Variables:
4769 ======================
4771 U-Boot supports user configuration using Environment Variables which
4772 can be made persistent by saving to Flash memory.
4774 Environment Variables are set using "setenv", printed using
4775 "printenv", and saved to Flash using "saveenv". Using "setenv"
4776 without a value can be used to delete a variable from the
4777 environment. As long as you don't save the environment you are
4778 working with an in-memory copy. In case the Flash area containing the
4779 environment is erased by accident, a default environment is provided.
4781 Some configuration options can be set using Environment Variables.
4783 List of environment variables (most likely not complete):
4785 baudrate - see CONFIG_BAUDRATE
4787 bootdelay - see CONFIG_BOOTDELAY
4789 bootcmd - see CONFIG_BOOTCOMMAND
4791 bootargs - Boot arguments when booting an RTOS image
4793 bootfile - Name of the image to load with TFTP
4795 bootm_low - Memory range available for image processing in the bootm
4796 command can be restricted. This variable is given as
4797 a hexadecimal number and defines lowest address allowed
4798 for use by the bootm command. See also "bootm_size"
4799 environment variable. Address defined by "bootm_low" is
4800 also the base of the initial memory mapping for the Linux
4801 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4804 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4805 This variable is given as a hexadecimal number and it
4806 defines the size of the memory region starting at base
4807 address bootm_low that is accessible by the Linux kernel
4808 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4809 as the default value if it is defined, and bootm_size is
4812 bootm_size - Memory range available for image processing in the bootm
4813 command can be restricted. This variable is given as
4814 a hexadecimal number and defines the size of the region
4815 allowed for use by the bootm command. See also "bootm_low"
4816 environment variable.
4818 updatefile - Location of the software update file on a TFTP server, used
4819 by the automatic software update feature. Please refer to
4820 documentation in doc/README.update for more details.
4822 autoload - if set to "no" (any string beginning with 'n'),
4823 "bootp" will just load perform a lookup of the
4824 configuration from the BOOTP server, but not try to
4825 load any image using TFTP
4827 autostart - if set to "yes", an image loaded using the "bootp",
4828 "rarpboot", "tftpboot" or "diskboot" commands will
4829 be automatically started (by internally calling
4832 If set to "no", a standalone image passed to the
4833 "bootm" command will be copied to the load address
4834 (and eventually uncompressed), but NOT be started.
4835 This can be used to load and uncompress arbitrary
4838 fdt_high - if set this restricts the maximum address that the
4839 flattened device tree will be copied into upon boot.
4840 For example, if you have a system with 1 GB memory
4841 at physical address 0x10000000, while Linux kernel
4842 only recognizes the first 704 MB as low memory, you
4843 may need to set fdt_high as 0x3C000000 to have the
4844 device tree blob be copied to the maximum address
4845 of the 704 MB low memory, so that Linux kernel can
4846 access it during the boot procedure.
4848 If this is set to the special value 0xFFFFFFFF then
4849 the fdt will not be copied at all on boot. For this
4850 to work it must reside in writable memory, have
4851 sufficient padding on the end of it for u-boot to
4852 add the information it needs into it, and the memory
4853 must be accessible by the kernel.
4855 fdtcontroladdr- if set this is the address of the control flattened
4856 device tree used by U-Boot when CONFIG_OF_CONTROL is
4859 i2cfast - (PPC405GP|PPC405EP only)
4860 if set to 'y' configures Linux I2C driver for fast
4861 mode (400kHZ). This environment variable is used in
4862 initialization code. So, for changes to be effective
4863 it must be saved and board must be reset.
4865 initrd_high - restrict positioning of initrd images:
4866 If this variable is not set, initrd images will be
4867 copied to the highest possible address in RAM; this
4868 is usually what you want since it allows for
4869 maximum initrd size. If for some reason you want to
4870 make sure that the initrd image is loaded below the
4871 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4872 variable to a value of "no" or "off" or "0".
4873 Alternatively, you can set it to a maximum upper
4874 address to use (U-Boot will still check that it
4875 does not overwrite the U-Boot stack and data).
4877 For instance, when you have a system with 16 MB
4878 RAM, and want to reserve 4 MB from use by Linux,
4879 you can do this by adding "mem=12M" to the value of
4880 the "bootargs" variable. However, now you must make
4881 sure that the initrd image is placed in the first
4882 12 MB as well - this can be done with
4884 setenv initrd_high 00c00000
4886 If you set initrd_high to 0xFFFFFFFF, this is an
4887 indication to U-Boot that all addresses are legal
4888 for the Linux kernel, including addresses in flash
4889 memory. In this case U-Boot will NOT COPY the
4890 ramdisk at all. This may be useful to reduce the
4891 boot time on your system, but requires that this
4892 feature is supported by your Linux kernel.
4894 ipaddr - IP address; needed for tftpboot command
4896 loadaddr - Default load address for commands like "bootp",
4897 "rarpboot", "tftpboot", "loadb" or "diskboot"
4899 loads_echo - see CONFIG_LOADS_ECHO
4901 serverip - TFTP server IP address; needed for tftpboot command
4903 bootretry - see CONFIG_BOOT_RETRY_TIME
4905 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4907 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4909 ethprime - controls which interface is used first.
4911 ethact - controls which interface is currently active.
4912 For example you can do the following
4914 => setenv ethact FEC
4915 => ping 192.168.0.1 # traffic sent on FEC
4916 => setenv ethact SCC
4917 => ping 10.0.0.1 # traffic sent on SCC
4919 ethrotate - When set to "no" U-Boot does not go through all
4920 available network interfaces.
4921 It just stays at the currently selected interface.
4923 netretry - When set to "no" each network operation will
4924 either succeed or fail without retrying.
4925 When set to "once" the network operation will
4926 fail when all the available network interfaces
4927 are tried once without success.
4928 Useful on scripts which control the retry operation
4931 npe_ucode - set load address for the NPE microcode
4933 silent_linux - If set then linux will be told to boot silently, by
4934 changing the console to be empty. If "yes" it will be
4935 made silent. If "no" it will not be made silent. If
4936 unset, then it will be made silent if the U-Boot console
4939 tftpsrcport - If this is set, the value is used for TFTP's
4942 tftpdstport - If this is set, the value is used for TFTP's UDP
4943 destination port instead of the Well Know Port 69.
4945 tftpblocksize - Block size to use for TFTP transfers; if not set,
4946 we use the TFTP server's default block size
4948 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4949 seconds, minimum value is 1000 = 1 second). Defines
4950 when a packet is considered to be lost so it has to
4951 be retransmitted. The default is 5000 = 5 seconds.
4952 Lowering this value may make downloads succeed
4953 faster in networks with high packet loss rates or
4954 with unreliable TFTP servers.
4956 vlan - When set to a value < 4095 the traffic over
4957 Ethernet is encapsulated/received over 802.1q
4960 The following image location variables contain the location of images
4961 used in booting. The "Image" column gives the role of the image and is
4962 not an environment variable name. The other columns are environment
4963 variable names. "File Name" gives the name of the file on a TFTP
4964 server, "RAM Address" gives the location in RAM the image will be
4965 loaded to, and "Flash Location" gives the image's address in NOR
4966 flash or offset in NAND flash.
4968 *Note* - these variables don't have to be defined for all boards, some
4969 boards currenlty use other variables for these purposes, and some
4970 boards use these variables for other purposes.
4972 Image File Name RAM Address Flash Location
4973 ----- --------- ----------- --------------
4974 u-boot u-boot u-boot_addr_r u-boot_addr
4975 Linux kernel bootfile kernel_addr_r kernel_addr
4976 device tree blob fdtfile fdt_addr_r fdt_addr
4977 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4979 The following environment variables may be used and automatically
4980 updated by the network boot commands ("bootp" and "rarpboot"),
4981 depending the information provided by your boot server:
4983 bootfile - see above
4984 dnsip - IP address of your Domain Name Server
4985 dnsip2 - IP address of your secondary Domain Name Server
4986 gatewayip - IP address of the Gateway (Router) to use
4987 hostname - Target hostname
4989 netmask - Subnet Mask
4990 rootpath - Pathname of the root filesystem on the NFS server
4991 serverip - see above
4994 There are two special Environment Variables:
4996 serial# - contains hardware identification information such
4997 as type string and/or serial number
4998 ethaddr - Ethernet address
5000 These variables can be set only once (usually during manufacturing of
5001 the board). U-Boot refuses to delete or overwrite these variables
5002 once they have been set once.
5005 Further special Environment Variables:
5007 ver - Contains the U-Boot version string as printed
5008 with the "version" command. This variable is
5009 readonly (see CONFIG_VERSION_VARIABLE).
5012 Please note that changes to some configuration parameters may take
5013 only effect after the next boot (yes, that's just like Windoze :-).
5016 Callback functions for environment variables:
5017 ---------------------------------------------
5019 For some environment variables, the behavior of u-boot needs to change
5020 when their values are changed. This functionailty allows functions to
5021 be associated with arbitrary variables. On creation, overwrite, or
5022 deletion, the callback will provide the opportunity for some side
5023 effect to happen or for the change to be rejected.
5025 The callbacks are named and associated with a function using the
5026 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5028 These callbacks are associated with variables in one of two ways. The
5029 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5030 in the board configuration to a string that defines a list of
5031 associations. The list must be in the following format:
5033 entry = variable_name[:callback_name]
5036 If the callback name is not specified, then the callback is deleted.
5037 Spaces are also allowed anywhere in the list.
5039 Callbacks can also be associated by defining the ".callbacks" variable
5040 with the same list format above. Any association in ".callbacks" will
5041 override any association in the static list. You can define
5042 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5043 ".callbacks" envirnoment variable in the default or embedded environment.
5046 Command Line Parsing:
5047 =====================
5049 There are two different command line parsers available with U-Boot:
5050 the old "simple" one, and the much more powerful "hush" shell:
5052 Old, simple command line parser:
5053 --------------------------------
5055 - supports environment variables (through setenv / saveenv commands)
5056 - several commands on one line, separated by ';'
5057 - variable substitution using "... ${name} ..." syntax
5058 - special characters ('$', ';') can be escaped by prefixing with '\',
5060 setenv bootcmd bootm \${address}
5061 - You can also escape text by enclosing in single apostrophes, for example:
5062 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5067 - similar to Bourne shell, with control structures like
5068 if...then...else...fi, for...do...done; while...do...done,
5069 until...do...done, ...
5070 - supports environment ("global") variables (through setenv / saveenv
5071 commands) and local shell variables (through standard shell syntax
5072 "name=value"); only environment variables can be used with "run"
5078 (1) If a command line (or an environment variable executed by a "run"
5079 command) contains several commands separated by semicolon, and
5080 one of these commands fails, then the remaining commands will be
5083 (2) If you execute several variables with one call to run (i. e.
5084 calling run with a list of variables as arguments), any failing
5085 command will cause "run" to terminate, i. e. the remaining
5086 variables are not executed.
5088 Note for Redundant Ethernet Interfaces:
5089 =======================================
5091 Some boards come with redundant Ethernet interfaces; U-Boot supports
5092 such configurations and is capable of automatic selection of a
5093 "working" interface when needed. MAC assignment works as follows:
5095 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5096 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5097 "eth1addr" (=>eth1), "eth2addr", ...
5099 If the network interface stores some valid MAC address (for instance
5100 in SROM), this is used as default address if there is NO correspon-
5101 ding setting in the environment; if the corresponding environment
5102 variable is set, this overrides the settings in the card; that means:
5104 o If the SROM has a valid MAC address, and there is no address in the
5105 environment, the SROM's address is used.
5107 o If there is no valid address in the SROM, and a definition in the
5108 environment exists, then the value from the environment variable is
5111 o If both the SROM and the environment contain a MAC address, and
5112 both addresses are the same, this MAC address is used.
5114 o If both the SROM and the environment contain a MAC address, and the
5115 addresses differ, the value from the environment is used and a
5118 o If neither SROM nor the environment contain a MAC address, an error
5121 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5122 will be programmed into hardware as part of the initialization process. This
5123 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5124 The naming convention is as follows:
5125 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5130 U-Boot is capable of booting (and performing other auxiliary operations on)
5131 images in two formats:
5133 New uImage format (FIT)
5134 -----------------------
5136 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5137 to Flattened Device Tree). It allows the use of images with multiple
5138 components (several kernels, ramdisks, etc.), with contents protected by
5139 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5145 Old image format is based on binary files which can be basically anything,
5146 preceded by a special header; see the definitions in include/image.h for
5147 details; basically, the header defines the following image properties:
5149 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5150 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5151 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5152 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5154 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5155 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5156 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5157 * Compression Type (uncompressed, gzip, bzip2)
5163 The header is marked by a special Magic Number, and both the header
5164 and the data portions of the image are secured against corruption by
5171 Although U-Boot should support any OS or standalone application
5172 easily, the main focus has always been on Linux during the design of
5175 U-Boot includes many features that so far have been part of some
5176 special "boot loader" code within the Linux kernel. Also, any
5177 "initrd" images to be used are no longer part of one big Linux image;
5178 instead, kernel and "initrd" are separate images. This implementation
5179 serves several purposes:
5181 - the same features can be used for other OS or standalone
5182 applications (for instance: using compressed images to reduce the
5183 Flash memory footprint)
5185 - it becomes much easier to port new Linux kernel versions because
5186 lots of low-level, hardware dependent stuff are done by U-Boot
5188 - the same Linux kernel image can now be used with different "initrd"
5189 images; of course this also means that different kernel images can
5190 be run with the same "initrd". This makes testing easier (you don't
5191 have to build a new "zImage.initrd" Linux image when you just
5192 change a file in your "initrd"). Also, a field-upgrade of the
5193 software is easier now.
5199 Porting Linux to U-Boot based systems:
5200 ---------------------------------------
5202 U-Boot cannot save you from doing all the necessary modifications to
5203 configure the Linux device drivers for use with your target hardware
5204 (no, we don't intend to provide a full virtual machine interface to
5207 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5209 Just make sure your machine specific header file (for instance
5210 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5211 Information structure as we define in include/asm-<arch>/u-boot.h,
5212 and make sure that your definition of IMAP_ADDR uses the same value
5213 as your U-Boot configuration in CONFIG_SYS_IMMR.
5216 Configuring the Linux kernel:
5217 -----------------------------
5219 No specific requirements for U-Boot. Make sure you have some root
5220 device (initial ramdisk, NFS) for your target system.
5223 Building a Linux Image:
5224 -----------------------
5226 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5227 not used. If you use recent kernel source, a new build target
5228 "uImage" will exist which automatically builds an image usable by
5229 U-Boot. Most older kernels also have support for a "pImage" target,
5230 which was introduced for our predecessor project PPCBoot and uses a
5231 100% compatible format.
5240 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5241 encapsulate a compressed Linux kernel image with header information,
5242 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5244 * build a standard "vmlinux" kernel image (in ELF binary format):
5246 * convert the kernel into a raw binary image:
5248 ${CROSS_COMPILE}-objcopy -O binary \
5249 -R .note -R .comment \
5250 -S vmlinux linux.bin
5252 * compress the binary image:
5256 * package compressed binary image for U-Boot:
5258 mkimage -A ppc -O linux -T kernel -C gzip \
5259 -a 0 -e 0 -n "Linux Kernel Image" \
5260 -d linux.bin.gz uImage
5263 The "mkimage" tool can also be used to create ramdisk images for use
5264 with U-Boot, either separated from the Linux kernel image, or
5265 combined into one file. "mkimage" encapsulates the images with a 64
5266 byte header containing information about target architecture,
5267 operating system, image type, compression method, entry points, time
5268 stamp, CRC32 checksums, etc.
5270 "mkimage" can be called in two ways: to verify existing images and
5271 print the header information, or to build new images.
5273 In the first form (with "-l" option) mkimage lists the information
5274 contained in the header of an existing U-Boot image; this includes
5275 checksum verification:
5277 tools/mkimage -l image
5278 -l ==> list image header information
5280 The second form (with "-d" option) is used to build a U-Boot image
5281 from a "data file" which is used as image payload:
5283 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5284 -n name -d data_file image
5285 -A ==> set architecture to 'arch'
5286 -O ==> set operating system to 'os'
5287 -T ==> set image type to 'type'
5288 -C ==> set compression type 'comp'
5289 -a ==> set load address to 'addr' (hex)
5290 -e ==> set entry point to 'ep' (hex)
5291 -n ==> set image name to 'name'
5292 -d ==> use image data from 'datafile'
5294 Right now, all Linux kernels for PowerPC systems use the same load
5295 address (0x00000000), but the entry point address depends on the
5298 - 2.2.x kernels have the entry point at 0x0000000C,
5299 - 2.3.x and later kernels have the entry point at 0x00000000.
5301 So a typical call to build a U-Boot image would read:
5303 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5304 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5305 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5306 > examples/uImage.TQM850L
5307 Image Name: 2.4.4 kernel for TQM850L
5308 Created: Wed Jul 19 02:34:59 2000
5309 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5310 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5311 Load Address: 0x00000000
5312 Entry Point: 0x00000000
5314 To verify the contents of the image (or check for corruption):
5316 -> tools/mkimage -l examples/uImage.TQM850L
5317 Image Name: 2.4.4 kernel for TQM850L
5318 Created: Wed Jul 19 02:34:59 2000
5319 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5320 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5321 Load Address: 0x00000000
5322 Entry Point: 0x00000000
5324 NOTE: for embedded systems where boot time is critical you can trade
5325 speed for memory and install an UNCOMPRESSED image instead: this
5326 needs more space in Flash, but boots much faster since it does not
5327 need to be uncompressed:
5329 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5330 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5331 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5332 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5333 > examples/uImage.TQM850L-uncompressed
5334 Image Name: 2.4.4 kernel for TQM850L
5335 Created: Wed Jul 19 02:34:59 2000
5336 Image Type: PowerPC Linux Kernel Image (uncompressed)
5337 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5338 Load Address: 0x00000000
5339 Entry Point: 0x00000000
5342 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5343 when your kernel is intended to use an initial ramdisk:
5345 -> tools/mkimage -n 'Simple Ramdisk Image' \
5346 > -A ppc -O linux -T ramdisk -C gzip \
5347 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5348 Image Name: Simple Ramdisk Image
5349 Created: Wed Jan 12 14:01:50 2000
5350 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5351 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5352 Load Address: 0x00000000
5353 Entry Point: 0x00000000
5355 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5356 option performs the converse operation of the mkimage's second form (the "-d"
5357 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5360 tools/dumpimage -i image -p position data_file
5361 -i ==> extract from the 'image' a specific 'data_file', \
5362 indexed by 'position'
5365 Installing a Linux Image:
5366 -------------------------
5368 To downloading a U-Boot image over the serial (console) interface,
5369 you must convert the image to S-Record format:
5371 objcopy -I binary -O srec examples/image examples/image.srec
5373 The 'objcopy' does not understand the information in the U-Boot
5374 image header, so the resulting S-Record file will be relative to
5375 address 0x00000000. To load it to a given address, you need to
5376 specify the target address as 'offset' parameter with the 'loads'
5379 Example: install the image to address 0x40100000 (which on the
5380 TQM8xxL is in the first Flash bank):
5382 => erase 40100000 401FFFFF
5388 ## Ready for S-Record download ...
5389 ~>examples/image.srec
5390 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5392 15989 15990 15991 15992
5393 [file transfer complete]
5395 ## Start Addr = 0x00000000
5398 You can check the success of the download using the 'iminfo' command;
5399 this includes a checksum verification so you can be sure no data
5400 corruption happened:
5404 ## Checking Image at 40100000 ...
5405 Image Name: 2.2.13 for initrd on TQM850L
5406 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5407 Data Size: 335725 Bytes = 327 kB = 0 MB
5408 Load Address: 00000000
5409 Entry Point: 0000000c
5410 Verifying Checksum ... OK
5416 The "bootm" command is used to boot an application that is stored in
5417 memory (RAM or Flash). In case of a Linux kernel image, the contents
5418 of the "bootargs" environment variable is passed to the kernel as
5419 parameters. You can check and modify this variable using the
5420 "printenv" and "setenv" commands:
5423 => printenv bootargs
5424 bootargs=root=/dev/ram
5426 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5428 => printenv bootargs
5429 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5432 ## Booting Linux kernel at 40020000 ...
5433 Image Name: 2.2.13 for NFS on TQM850L
5434 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5435 Data Size: 381681 Bytes = 372 kB = 0 MB
5436 Load Address: 00000000
5437 Entry Point: 0000000c
5438 Verifying Checksum ... OK
5439 Uncompressing Kernel Image ... OK
5440 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
5441 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5442 time_init: decrementer frequency = 187500000/60
5443 Calibrating delay loop... 49.77 BogoMIPS
5444 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5447 If you want to boot a Linux kernel with initial RAM disk, you pass
5448 the memory addresses of both the kernel and the initrd image (PPBCOOT
5449 format!) to the "bootm" command:
5451 => imi 40100000 40200000
5453 ## Checking Image at 40100000 ...
5454 Image Name: 2.2.13 for initrd on TQM850L
5455 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5456 Data Size: 335725 Bytes = 327 kB = 0 MB
5457 Load Address: 00000000
5458 Entry Point: 0000000c
5459 Verifying Checksum ... OK
5461 ## Checking Image at 40200000 ...
5462 Image Name: Simple Ramdisk Image
5463 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5464 Data Size: 566530 Bytes = 553 kB = 0 MB
5465 Load Address: 00000000
5466 Entry Point: 00000000
5467 Verifying Checksum ... OK
5469 => bootm 40100000 40200000
5470 ## Booting Linux kernel at 40100000 ...
5471 Image Name: 2.2.13 for initrd on TQM850L
5472 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5473 Data Size: 335725 Bytes = 327 kB = 0 MB
5474 Load Address: 00000000
5475 Entry Point: 0000000c
5476 Verifying Checksum ... OK
5477 Uncompressing Kernel Image ... OK
5478 ## Loading RAMDisk Image at 40200000 ...
5479 Image Name: Simple Ramdisk Image
5480 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5481 Data Size: 566530 Bytes = 553 kB = 0 MB
5482 Load Address: 00000000
5483 Entry Point: 00000000
5484 Verifying Checksum ... OK
5485 Loading Ramdisk ... OK
5486 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
5487 Boot arguments: root=/dev/ram
5488 time_init: decrementer frequency = 187500000/60
5489 Calibrating delay loop... 49.77 BogoMIPS
5491 RAMDISK: Compressed image found at block 0
5492 VFS: Mounted root (ext2 filesystem).
5496 Boot Linux and pass a flat device tree:
5499 First, U-Boot must be compiled with the appropriate defines. See the section
5500 titled "Linux Kernel Interface" above for a more in depth explanation. The
5501 following is an example of how to start a kernel and pass an updated
5507 oft=oftrees/mpc8540ads.dtb
5508 => tftp $oftaddr $oft
5509 Speed: 1000, full duplex
5511 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5512 Filename 'oftrees/mpc8540ads.dtb'.
5513 Load address: 0x300000
5516 Bytes transferred = 4106 (100a hex)
5517 => tftp $loadaddr $bootfile
5518 Speed: 1000, full duplex
5520 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5522 Load address: 0x200000
5523 Loading:############
5525 Bytes transferred = 1029407 (fb51f hex)
5530 => bootm $loadaddr - $oftaddr
5531 ## Booting image at 00200000 ...
5532 Image Name: Linux-2.6.17-dirty
5533 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5534 Data Size: 1029343 Bytes = 1005.2 kB
5535 Load Address: 00000000
5536 Entry Point: 00000000
5537 Verifying Checksum ... OK
5538 Uncompressing Kernel Image ... OK
5539 Booting using flat device tree at 0x300000
5540 Using MPC85xx ADS machine description
5541 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5545 More About U-Boot Image Types:
5546 ------------------------------
5548 U-Boot supports the following image types:
5550 "Standalone Programs" are directly runnable in the environment
5551 provided by U-Boot; it is expected that (if they behave
5552 well) you can continue to work in U-Boot after return from
5553 the Standalone Program.
5554 "OS Kernel Images" are usually images of some Embedded OS which
5555 will take over control completely. Usually these programs
5556 will install their own set of exception handlers, device
5557 drivers, set up the MMU, etc. - this means, that you cannot
5558 expect to re-enter U-Boot except by resetting the CPU.
5559 "RAMDisk Images" are more or less just data blocks, and their
5560 parameters (address, size) are passed to an OS kernel that is
5562 "Multi-File Images" contain several images, typically an OS
5563 (Linux) kernel image and one or more data images like
5564 RAMDisks. This construct is useful for instance when you want
5565 to boot over the network using BOOTP etc., where the boot
5566 server provides just a single image file, but you want to get
5567 for instance an OS kernel and a RAMDisk image.
5569 "Multi-File Images" start with a list of image sizes, each
5570 image size (in bytes) specified by an "uint32_t" in network
5571 byte order. This list is terminated by an "(uint32_t)0".
5572 Immediately after the terminating 0 follow the images, one by
5573 one, all aligned on "uint32_t" boundaries (size rounded up to
5574 a multiple of 4 bytes).
5576 "Firmware Images" are binary images containing firmware (like
5577 U-Boot or FPGA images) which usually will be programmed to
5580 "Script files" are command sequences that will be executed by
5581 U-Boot's command interpreter; this feature is especially
5582 useful when you configure U-Boot to use a real shell (hush)
5583 as command interpreter.
5585 Booting the Linux zImage:
5586 -------------------------
5588 On some platforms, it's possible to boot Linux zImage. This is done
5589 using the "bootz" command. The syntax of "bootz" command is the same
5590 as the syntax of "bootm" command.
5592 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5593 kernel with raw initrd images. The syntax is slightly different, the
5594 address of the initrd must be augmented by it's size, in the following
5595 format: "<initrd addres>:<initrd size>".
5601 One of the features of U-Boot is that you can dynamically load and
5602 run "standalone" applications, which can use some resources of
5603 U-Boot like console I/O functions or interrupt services.
5605 Two simple examples are included with the sources:
5610 'examples/hello_world.c' contains a small "Hello World" Demo
5611 application; it is automatically compiled when you build U-Boot.
5612 It's configured to run at address 0x00040004, so you can play with it
5616 ## Ready for S-Record download ...
5617 ~>examples/hello_world.srec
5618 1 2 3 4 5 6 7 8 9 10 11 ...
5619 [file transfer complete]
5621 ## Start Addr = 0x00040004
5623 => go 40004 Hello World! This is a test.
5624 ## Starting application at 0x00040004 ...
5635 Hit any key to exit ...
5637 ## Application terminated, rc = 0x0
5639 Another example, which demonstrates how to register a CPM interrupt
5640 handler with the U-Boot code, can be found in 'examples/timer.c'.
5641 Here, a CPM timer is set up to generate an interrupt every second.
5642 The interrupt service routine is trivial, just printing a '.'
5643 character, but this is just a demo program. The application can be
5644 controlled by the following keys:
5646 ? - print current values og the CPM Timer registers
5647 b - enable interrupts and start timer
5648 e - stop timer and disable interrupts
5649 q - quit application
5652 ## Ready for S-Record download ...
5653 ~>examples/timer.srec
5654 1 2 3 4 5 6 7 8 9 10 11 ...
5655 [file transfer complete]
5657 ## Start Addr = 0x00040004
5660 ## Starting application at 0x00040004 ...
5663 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5666 [q, b, e, ?] Set interval 1000000 us
5669 [q, b, e, ?] ........
5670 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5673 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5676 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5679 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5681 [q, b, e, ?] ...Stopping timer
5683 [q, b, e, ?] ## Application terminated, rc = 0x0
5689 Over time, many people have reported problems when trying to use the
5690 "minicom" terminal emulation program for serial download. I (wd)
5691 consider minicom to be broken, and recommend not to use it. Under
5692 Unix, I recommend to use C-Kermit for general purpose use (and
5693 especially for kermit binary protocol download ("loadb" command), and
5694 use "cu" for S-Record download ("loads" command). See
5695 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5696 for help with kermit.
5699 Nevertheless, if you absolutely want to use it try adding this
5700 configuration to your "File transfer protocols" section:
5702 Name Program Name U/D FullScr IO-Red. Multi
5703 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5704 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5710 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5711 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5713 Building requires a cross environment; it is known to work on
5714 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5715 need gmake since the Makefiles are not compatible with BSD make).
5716 Note that the cross-powerpc package does not install include files;
5717 attempting to build U-Boot will fail because <machine/ansi.h> is
5718 missing. This file has to be installed and patched manually:
5720 # cd /usr/pkg/cross/powerpc-netbsd/include
5722 # ln -s powerpc machine
5723 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5724 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5726 Native builds *don't* work due to incompatibilities between native
5727 and U-Boot include files.
5729 Booting assumes that (the first part of) the image booted is a
5730 stage-2 loader which in turn loads and then invokes the kernel
5731 proper. Loader sources will eventually appear in the NetBSD source
5732 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5733 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5736 Implementation Internals:
5737 =========================
5739 The following is not intended to be a complete description of every
5740 implementation detail. However, it should help to understand the
5741 inner workings of U-Boot and make it easier to port it to custom
5745 Initial Stack, Global Data:
5746 ---------------------------
5748 The implementation of U-Boot is complicated by the fact that U-Boot
5749 starts running out of ROM (flash memory), usually without access to
5750 system RAM (because the memory controller is not initialized yet).
5751 This means that we don't have writable Data or BSS segments, and BSS
5752 is not initialized as zero. To be able to get a C environment working
5753 at all, we have to allocate at least a minimal stack. Implementation
5754 options for this are defined and restricted by the CPU used: Some CPU
5755 models provide on-chip memory (like the IMMR area on MPC8xx and
5756 MPC826x processors), on others (parts of) the data cache can be
5757 locked as (mis-) used as memory, etc.
5759 Chris Hallinan posted a good summary of these issues to the
5760 U-Boot mailing list:
5762 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5763 From: "Chris Hallinan" <clh@net1plus.com>
5764 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5767 Correct me if I'm wrong, folks, but the way I understand it
5768 is this: Using DCACHE as initial RAM for Stack, etc, does not
5769 require any physical RAM backing up the cache. The cleverness
5770 is that the cache is being used as a temporary supply of
5771 necessary storage before the SDRAM controller is setup. It's
5772 beyond the scope of this list to explain the details, but you
5773 can see how this works by studying the cache architecture and
5774 operation in the architecture and processor-specific manuals.
5776 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5777 is another option for the system designer to use as an
5778 initial stack/RAM area prior to SDRAM being available. Either
5779 option should work for you. Using CS 4 should be fine if your
5780 board designers haven't used it for something that would
5781 cause you grief during the initial boot! It is frequently not
5784 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5785 with your processor/board/system design. The default value
5786 you will find in any recent u-boot distribution in
5787 walnut.h should work for you. I'd set it to a value larger
5788 than your SDRAM module. If you have a 64MB SDRAM module, set
5789 it above 400_0000. Just make sure your board has no resources
5790 that are supposed to respond to that address! That code in
5791 start.S has been around a while and should work as is when
5792 you get the config right.
5797 It is essential to remember this, since it has some impact on the C
5798 code for the initialization procedures:
5800 * Initialized global data (data segment) is read-only. Do not attempt
5803 * Do not use any uninitialized global data (or implicitely initialized
5804 as zero data - BSS segment) at all - this is undefined, initiali-
5805 zation is performed later (when relocating to RAM).
5807 * Stack space is very limited. Avoid big data buffers or things like
5810 Having only the stack as writable memory limits means we cannot use
5811 normal global data to share information beween the code. But it
5812 turned out that the implementation of U-Boot can be greatly
5813 simplified by making a global data structure (gd_t) available to all
5814 functions. We could pass a pointer to this data as argument to _all_
5815 functions, but this would bloat the code. Instead we use a feature of
5816 the GCC compiler (Global Register Variables) to share the data: we
5817 place a pointer (gd) to the global data into a register which we
5818 reserve for this purpose.
5820 When choosing a register for such a purpose we are restricted by the
5821 relevant (E)ABI specifications for the current architecture, and by
5822 GCC's implementation.
5824 For PowerPC, the following registers have specific use:
5826 R2: reserved for system use
5827 R3-R4: parameter passing and return values
5828 R5-R10: parameter passing
5829 R13: small data area pointer
5833 (U-Boot also uses R12 as internal GOT pointer. r12
5834 is a volatile register so r12 needs to be reset when
5835 going back and forth between asm and C)
5837 ==> U-Boot will use R2 to hold a pointer to the global data
5839 Note: on PPC, we could use a static initializer (since the
5840 address of the global data structure is known at compile time),
5841 but it turned out that reserving a register results in somewhat
5842 smaller code - although the code savings are not that big (on
5843 average for all boards 752 bytes for the whole U-Boot image,
5844 624 text + 127 data).
5846 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5847 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5849 ==> U-Boot will use P3 to hold a pointer to the global data
5851 On ARM, the following registers are used:
5853 R0: function argument word/integer result
5854 R1-R3: function argument word
5855 R9: platform specific
5856 R10: stack limit (used only if stack checking is enabled)
5857 R11: argument (frame) pointer
5858 R12: temporary workspace
5861 R15: program counter
5863 ==> U-Boot will use R9 to hold a pointer to the global data
5865 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5867 On Nios II, the ABI is documented here:
5868 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5870 ==> U-Boot will use gp to hold a pointer to the global data
5872 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5873 to access small data sections, so gp is free.
5875 On NDS32, the following registers are used:
5877 R0-R1: argument/return
5879 R15: temporary register for assembler
5880 R16: trampoline register
5881 R28: frame pointer (FP)
5882 R29: global pointer (GP)
5883 R30: link register (LP)
5884 R31: stack pointer (SP)
5885 PC: program counter (PC)
5887 ==> U-Boot will use R10 to hold a pointer to the global data
5889 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5890 or current versions of GCC may "optimize" the code too much.
5895 U-Boot runs in system state and uses physical addresses, i.e. the
5896 MMU is not used either for address mapping nor for memory protection.
5898 The available memory is mapped to fixed addresses using the memory
5899 controller. In this process, a contiguous block is formed for each
5900 memory type (Flash, SDRAM, SRAM), even when it consists of several
5901 physical memory banks.
5903 U-Boot is installed in the first 128 kB of the first Flash bank (on
5904 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5905 booting and sizing and initializing DRAM, the code relocates itself
5906 to the upper end of DRAM. Immediately below the U-Boot code some
5907 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5908 configuration setting]. Below that, a structure with global Board
5909 Info data is placed, followed by the stack (growing downward).
5911 Additionally, some exception handler code is copied to the low 8 kB
5912 of DRAM (0x00000000 ... 0x00001FFF).
5914 So a typical memory configuration with 16 MB of DRAM could look like
5917 0x0000 0000 Exception Vector code
5920 0x0000 2000 Free for Application Use
5926 0x00FB FF20 Monitor Stack (Growing downward)
5927 0x00FB FFAC Board Info Data and permanent copy of global data
5928 0x00FC 0000 Malloc Arena
5931 0x00FE 0000 RAM Copy of Monitor Code
5932 ... eventually: LCD or video framebuffer
5933 ... eventually: pRAM (Protected RAM - unchanged by reset)
5934 0x00FF FFFF [End of RAM]
5937 System Initialization:
5938 ----------------------
5940 In the reset configuration, U-Boot starts at the reset entry point
5941 (on most PowerPC systems at address 0x00000100). Because of the reset
5942 configuration for CS0# this is a mirror of the onboard Flash memory.
5943 To be able to re-map memory U-Boot then jumps to its link address.
5944 To be able to implement the initialization code in C, a (small!)
5945 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5946 which provide such a feature like MPC8xx or MPC8260), or in a locked
5947 part of the data cache. After that, U-Boot initializes the CPU core,
5948 the caches and the SIU.
5950 Next, all (potentially) available memory banks are mapped using a
5951 preliminary mapping. For example, we put them on 512 MB boundaries
5952 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5953 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5954 programmed for SDRAM access. Using the temporary configuration, a
5955 simple memory test is run that determines the size of the SDRAM
5958 When there is more than one SDRAM bank, and the banks are of
5959 different size, the largest is mapped first. For equal size, the first
5960 bank (CS2#) is mapped first. The first mapping is always for address
5961 0x00000000, with any additional banks following immediately to create
5962 contiguous memory starting from 0.
5964 Then, the monitor installs itself at the upper end of the SDRAM area
5965 and allocates memory for use by malloc() and for the global Board
5966 Info data; also, the exception vector code is copied to the low RAM
5967 pages, and the final stack is set up.
5969 Only after this relocation will you have a "normal" C environment;
5970 until that you are restricted in several ways, mostly because you are
5971 running from ROM, and because the code will have to be relocated to a
5975 U-Boot Porting Guide:
5976 ----------------------
5978 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5982 int main(int argc, char *argv[])
5984 sighandler_t no_more_time;
5986 signal(SIGALRM, no_more_time);
5987 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5989 if (available_money > available_manpower) {
5990 Pay consultant to port U-Boot;
5994 Download latest U-Boot source;
5996 Subscribe to u-boot mailing list;
5999 email("Hi, I am new to U-Boot, how do I get started?");
6002 Read the README file in the top level directory;
6003 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
6004 Read applicable doc/*.README;
6005 Read the source, Luke;
6006 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
6009 if (available_money > toLocalCurrency ($2500))
6012 Add a lot of aggravation and time;
6014 if (a similar board exists) { /* hopefully... */
6015 cp -a board/<similar> board/<myboard>
6016 cp include/configs/<similar>.h include/configs/<myboard>.h
6018 Create your own board support subdirectory;
6019 Create your own board include/configs/<myboard>.h file;
6021 Edit new board/<myboard> files
6022 Edit new include/configs/<myboard>.h
6027 Add / modify source code;
6031 email("Hi, I am having problems...");
6033 Send patch file to the U-Boot email list;
6034 if (reasonable critiques)
6035 Incorporate improvements from email list code review;
6037 Defend code as written;
6043 void no_more_time (int sig)
6052 All contributions to U-Boot should conform to the Linux kernel
6053 coding style; see the file "Documentation/CodingStyle" and the script
6054 "scripts/Lindent" in your Linux kernel source directory.
6056 Source files originating from a different project (for example the
6057 MTD subsystem) are generally exempt from these guidelines and are not
6058 reformated to ease subsequent migration to newer versions of those
6061 Please note that U-Boot is implemented in C (and to some small parts in
6062 Assembler); no C++ is used, so please do not use C++ style comments (//)
6065 Please also stick to the following formatting rules:
6066 - remove any trailing white space
6067 - use TAB characters for indentation and vertical alignment, not spaces
6068 - make sure NOT to use DOS '\r\n' line feeds
6069 - do not add more than 2 consecutive empty lines to source files
6070 - do not add trailing empty lines to source files
6072 Submissions which do not conform to the standards may be returned
6073 with a request to reformat the changes.
6079 Since the number of patches for U-Boot is growing, we need to
6080 establish some rules. Submissions which do not conform to these rules
6081 may be rejected, even when they contain important and valuable stuff.
6083 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6085 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6086 see http://lists.denx.de/mailman/listinfo/u-boot
6088 When you send a patch, please include the following information with
6091 * For bug fixes: a description of the bug and how your patch fixes
6092 this bug. Please try to include a way of demonstrating that the
6093 patch actually fixes something.
6095 * For new features: a description of the feature and your
6098 * A CHANGELOG entry as plaintext (separate from the patch)
6100 * For major contributions, your entry to the CREDITS file
6102 * When you add support for a new board, don't forget to add a
6103 maintainer e-mail address to the boards.cfg file, too.
6105 * If your patch adds new configuration options, don't forget to
6106 document these in the README file.
6108 * The patch itself. If you are using git (which is *strongly*
6109 recommended) you can easily generate the patch using the
6110 "git format-patch". If you then use "git send-email" to send it to
6111 the U-Boot mailing list, you will avoid most of the common problems
6112 with some other mail clients.
6114 If you cannot use git, use "diff -purN OLD NEW". If your version of
6115 diff does not support these options, then get the latest version of
6118 The current directory when running this command shall be the parent
6119 directory of the U-Boot source tree (i. e. please make sure that
6120 your patch includes sufficient directory information for the
6123 We prefer patches as plain text. MIME attachments are discouraged,
6124 and compressed attachments must not be used.
6126 * If one logical set of modifications affects or creates several
6127 files, all these changes shall be submitted in a SINGLE patch file.
6129 * Changesets that contain different, unrelated modifications shall be
6130 submitted as SEPARATE patches, one patch per changeset.
6135 * Before sending the patch, run the MAKEALL script on your patched
6136 source tree and make sure that no errors or warnings are reported
6137 for any of the boards.
6139 * Keep your modifications to the necessary minimum: A patch
6140 containing several unrelated changes or arbitrary reformats will be
6141 returned with a request to re-formatting / split it.
6143 * If you modify existing code, make sure that your new code does not
6144 add to the memory footprint of the code ;-) Small is beautiful!
6145 When adding new features, these should compile conditionally only
6146 (using #ifdef), and the resulting code with the new feature
6147 disabled must not need more memory than the old code without your
6150 * Remember that there is a size limit of 100 kB per message on the
6151 u-boot mailing list. Bigger patches will be moderated. If they are
6152 reasonable and not too big, they will be acknowledged. But patches
6153 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob