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 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
437 Freescale DDR driver in use. This type of DDR controller is
438 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
441 CONFIG_SYS_FSL_DDR_ADDR
442 Freescale DDR memory-mapped register base.
444 CONFIG_SYS_FSL_DDR_EMU
445 Specify emulator support for DDR. Some DDR features such as
446 deskew training are not available.
448 CONFIG_SYS_FSL_DDRC_GEN1
449 Freescale DDR1 controller.
451 CONFIG_SYS_FSL_DDRC_GEN2
452 Freescale DDR2 controller.
454 CONFIG_SYS_FSL_DDRC_GEN3
455 Freescale DDR3 controller.
457 CONFIG_SYS_FSL_DDRC_ARM_GEN3
458 Freescale DDR3 controller for ARM-based SoCs.
461 Board config to use DDR1. It can be enabled for SoCs with
462 Freescale DDR1 or DDR2 controllers, depending on the board
466 Board config to use DDR2. It can be eanbeld for SoCs with
467 Freescale DDR2 or DDR3 controllers, depending on the board
471 Board config to use DDR3. It can be enabled for SoCs with
472 Freescale DDR3 controllers.
474 CONFIG_SYS_FSL_IFC_BE
475 Defines the IFC controller register space as Big Endian
477 CONFIG_SYS_FSL_IFC_LE
478 Defines the IFC controller register space as Little Endian
480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
489 CONFIG_SYS_FSL_DDR_BE
490 Defines the DDR controller register space as Big Endian
492 CONFIG_SYS_FSL_DDR_LE
493 Defines the DDR controller register space as Little Endian
495 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
496 Physical address from the view of DDR controllers. It is the
497 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
498 it could be different for ARM SoCs.
500 CONFIG_SYS_FSL_DDR_INTLV_256B
501 DDR controller interleaving on 256-byte. This is a special
502 interleaving mode, handled by Dickens for Freescale layerscape
505 - Intel Monahans options:
506 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
508 Defines the Monahans run mode to oscillator
509 ratio. Valid values are 8, 16, 24, 31. The core
510 frequency is this value multiplied by 13 MHz.
512 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
514 Defines the Monahans turbo mode to oscillator
515 ratio. Valid values are 1 (default if undefined) and
516 2. The core frequency as calculated above is multiplied
520 CONFIG_SYS_INIT_SP_OFFSET
522 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
523 pointer. This is needed for the temporary stack before
526 CONFIG_SYS_MIPS_CACHE_MODE
528 Cache operation mode for the MIPS CPU.
529 See also arch/mips/include/asm/mipsregs.h.
531 CONF_CM_CACHABLE_NO_WA
534 CONF_CM_CACHABLE_NONCOHERENT
538 CONF_CM_CACHABLE_ACCELERATED
540 CONFIG_SYS_XWAY_EBU_BOOTCFG
542 Special option for Lantiq XWAY SoCs for booting from NOR flash.
543 See also arch/mips/cpu/mips32/start.S.
545 CONFIG_XWAY_SWAP_BYTES
547 Enable compilation of tools/xway-swap-bytes needed for Lantiq
548 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
549 be swapped if a flash programmer is used.
552 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
554 Select high exception vectors of the ARM core, e.g., do not
555 clear the V bit of the c1 register of CP15.
557 CONFIG_SYS_THUMB_BUILD
559 Use this flag to build U-Boot using the Thumb instruction
560 set for ARM architectures. Thumb instruction set provides
561 better code density. For ARM architectures that support
562 Thumb2 this flag will result in Thumb2 code generated by
565 CONFIG_ARM_ERRATA_716044
566 CONFIG_ARM_ERRATA_742230
567 CONFIG_ARM_ERRATA_743622
568 CONFIG_ARM_ERRATA_751472
569 CONFIG_ARM_ERRATA_794072
570 CONFIG_ARM_ERRATA_761320
572 If set, the workarounds for these ARM errata are applied early
573 during U-Boot startup. Note that these options force the
574 workarounds to be applied; no CPU-type/version detection
575 exists, unlike the similar options in the Linux kernel. Do not
576 set these options unless they apply!
581 The frequency of the timer returned by get_timer().
582 get_timer() must operate in milliseconds and this CONFIG
583 option must be set to 1000.
585 - Linux Kernel Interface:
588 U-Boot stores all clock information in Hz
589 internally. For binary compatibility with older Linux
590 kernels (which expect the clocks passed in the
591 bd_info data to be in MHz) the environment variable
592 "clocks_in_mhz" can be defined so that U-Boot
593 converts clock data to MHZ before passing it to the
595 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
596 "clocks_in_mhz=1" is automatically included in the
599 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
601 When transferring memsize parameter to linux, some versions
602 expect it to be in bytes, others in MB.
603 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
607 New kernel versions are expecting firmware settings to be
608 passed using flattened device trees (based on open firmware
612 * New libfdt-based support
613 * Adds the "fdt" command
614 * The bootm command automatically updates the fdt
616 OF_CPU - The proper name of the cpus node (only required for
617 MPC512X and MPC5xxx based boards).
618 OF_SOC - The proper name of the soc node (only required for
619 MPC512X and MPC5xxx based boards).
620 OF_TBCLK - The timebase frequency.
621 OF_STDOUT_PATH - The path to the console device
623 boards with QUICC Engines require OF_QE to set UCC MAC
626 CONFIG_OF_BOARD_SETUP
628 Board code has addition modification that it wants to make
629 to the flat device tree before handing it off to the kernel
633 This define fills in the correct boot CPU in the boot
634 param header, the default value is zero if undefined.
638 U-Boot can detect if an IDE device is present or not.
639 If not, and this new config option is activated, U-Boot
640 removes the ATA node from the DTS before booting Linux,
641 so the Linux IDE driver does not probe the device and
642 crash. This is needed for buggy hardware (uc101) where
643 no pull down resistor is connected to the signal IDE5V_DD7.
645 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
647 This setting is mandatory for all boards that have only one
648 machine type and must be used to specify the machine type
649 number as it appears in the ARM machine registry
650 (see http://www.arm.linux.org.uk/developer/machines/).
651 Only boards that have multiple machine types supported
652 in a single configuration file and the machine type is
653 runtime discoverable, do not have to use this setting.
655 - vxWorks boot parameters:
657 bootvx constructs a valid bootline using the following
658 environments variables: bootfile, ipaddr, serverip, hostname.
659 It loads the vxWorks image pointed bootfile.
661 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
662 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
663 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
664 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
666 CONFIG_SYS_VXWORKS_ADD_PARAMS
668 Add it at the end of the bootline. E.g "u=username pw=secret"
670 Note: If a "bootargs" environment is defined, it will overwride
671 the defaults discussed just above.
673 - Cache Configuration:
674 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
675 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
676 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
678 - Cache Configuration for ARM:
679 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
681 CONFIG_SYS_PL310_BASE - Physical base address of PL310
682 controller register space
687 Define this if you want support for Amba PrimeCell PL010 UARTs.
691 Define this if you want support for Amba PrimeCell PL011 UARTs.
695 If you have Amba PrimeCell PL011 UARTs, set this variable to
696 the clock speed of the UARTs.
700 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
701 define this to a list of base addresses for each (supported)
702 port. See e.g. include/configs/versatile.h
704 CONFIG_PL011_SERIAL_RLCR
706 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
707 have separate receive and transmit line control registers. Set
708 this variable to initialize the extra register.
710 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
712 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
713 boot loader that has already initialized the UART. Define this
714 variable to flush the UART at init time.
718 Depending on board, define exactly one serial port
719 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
720 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
721 console by defining CONFIG_8xx_CONS_NONE
723 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
724 port routines must be defined elsewhere
725 (i.e. serial_init(), serial_getc(), ...)
728 Enables console device for a color framebuffer. Needs following
729 defines (cf. smiLynxEM, i8042)
730 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
732 VIDEO_HW_RECTFILL graphic chip supports
735 VIDEO_HW_BITBLT graphic chip supports
736 bit-blit (cf. smiLynxEM)
737 VIDEO_VISIBLE_COLS visible pixel columns
739 VIDEO_VISIBLE_ROWS visible pixel rows
740 VIDEO_PIXEL_SIZE bytes per pixel
741 VIDEO_DATA_FORMAT graphic data format
742 (0-5, cf. cfb_console.c)
743 VIDEO_FB_ADRS framebuffer address
744 VIDEO_KBD_INIT_FCT keyboard int fct
745 (i.e. i8042_kbd_init())
746 VIDEO_TSTC_FCT test char fct
748 VIDEO_GETC_FCT get char fct
750 CONFIG_CONSOLE_CURSOR cursor drawing on/off
751 (requires blink timer
753 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
754 CONFIG_CONSOLE_TIME display time/date info in
756 (requires CONFIG_CMD_DATE)
757 CONFIG_VIDEO_LOGO display Linux logo in
759 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
760 linux_logo.h for logo.
761 Requires CONFIG_VIDEO_LOGO
762 CONFIG_CONSOLE_EXTRA_INFO
763 additional board info beside
766 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
767 a limited number of ANSI escape sequences (cursor control,
768 erase functions and limited graphics rendition control).
770 When CONFIG_CFB_CONSOLE is defined, video console is
771 default i/o. Serial console can be forced with
772 environment 'console=serial'.
774 When CONFIG_SILENT_CONSOLE is defined, all console
775 messages (by U-Boot and Linux!) can be silenced with
776 the "silent" environment variable. See
777 doc/README.silent for more information.
779 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
781 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
785 CONFIG_BAUDRATE - in bps
786 Select one of the baudrates listed in
787 CONFIG_SYS_BAUDRATE_TABLE, see below.
788 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
790 - Console Rx buffer length
791 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
792 the maximum receive buffer length for the SMC.
793 This option is actual only for 82xx and 8xx possible.
794 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
795 must be defined, to setup the maximum idle timeout for
798 - Pre-Console Buffer:
799 Prior to the console being initialised (i.e. serial UART
800 initialised etc) all console output is silently discarded.
801 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
802 buffer any console messages prior to the console being
803 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
804 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
805 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
806 bytes are output before the console is initialised, the
807 earlier bytes are discarded.
809 'Sane' compilers will generate smaller code if
810 CONFIG_PRE_CON_BUF_SZ is a power of 2
812 - Safe printf() functions
813 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
814 the printf() functions. These are defined in
815 include/vsprintf.h and include snprintf(), vsnprintf() and
816 so on. Code size increase is approximately 300-500 bytes.
817 If this option is not given then these functions will
818 silently discard their buffer size argument - this means
819 you are not getting any overflow checking in this case.
821 - Boot Delay: CONFIG_BOOTDELAY - in seconds
822 Delay before automatically booting the default image;
823 set to -1 to disable autoboot.
824 set to -2 to autoboot with no delay and not check for abort
825 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
827 See doc/README.autoboot for these options that
828 work with CONFIG_BOOTDELAY. None are required.
829 CONFIG_BOOT_RETRY_TIME
830 CONFIG_BOOT_RETRY_MIN
831 CONFIG_AUTOBOOT_KEYED
832 CONFIG_AUTOBOOT_PROMPT
833 CONFIG_AUTOBOOT_DELAY_STR
834 CONFIG_AUTOBOOT_STOP_STR
835 CONFIG_AUTOBOOT_DELAY_STR2
836 CONFIG_AUTOBOOT_STOP_STR2
837 CONFIG_ZERO_BOOTDELAY_CHECK
838 CONFIG_RESET_TO_RETRY
842 Only needed when CONFIG_BOOTDELAY is enabled;
843 define a command string that is automatically executed
844 when no character is read on the console interface
845 within "Boot Delay" after reset.
848 This can be used to pass arguments to the bootm
849 command. The value of CONFIG_BOOTARGS goes into the
850 environment value "bootargs".
852 CONFIG_RAMBOOT and CONFIG_NFSBOOT
853 The value of these goes into the environment as
854 "ramboot" and "nfsboot" respectively, and can be used
855 as a convenience, when switching between booting from
859 CONFIG_BOOTCOUNT_LIMIT
860 Implements a mechanism for detecting a repeating reboot
862 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
865 If no softreset save registers are found on the hardware
866 "bootcount" is stored in the environment. To prevent a
867 saveenv on all reboots, the environment variable
868 "upgrade_available" is used. If "upgrade_available" is
869 0, "bootcount" is always 0, if "upgrade_available" is
870 1 "bootcount" is incremented in the environment.
871 So the Userspace Applikation must set the "upgrade_available"
872 and "bootcount" variable to 0, if a boot was successfully.
877 When this option is #defined, the existence of the
878 environment variable "preboot" will be checked
879 immediately before starting the CONFIG_BOOTDELAY
880 countdown and/or running the auto-boot command resp.
881 entering interactive mode.
883 This feature is especially useful when "preboot" is
884 automatically generated or modified. For an example
885 see the LWMON board specific code: here "preboot" is
886 modified when the user holds down a certain
887 combination of keys on the (special) keyboard when
890 - Serial Download Echo Mode:
892 If defined to 1, all characters received during a
893 serial download (using the "loads" command) are
894 echoed back. This might be needed by some terminal
895 emulations (like "cu"), but may as well just take
896 time on others. This setting #define's the initial
897 value of the "loads_echo" environment variable.
899 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
901 Select one of the baudrates listed in
902 CONFIG_SYS_BAUDRATE_TABLE, see below.
905 Monitor commands can be included or excluded
906 from the build by using the #include files
907 <config_cmd_all.h> and #undef'ing unwanted
908 commands, or using <config_cmd_default.h>
909 and augmenting with additional #define's
912 The default command configuration includes all commands
913 except those marked below with a "*".
915 CONFIG_CMD_ASKENV * ask for env variable
916 CONFIG_CMD_BDI bdinfo
917 CONFIG_CMD_BEDBUG * Include BedBug Debugger
918 CONFIG_CMD_BMP * BMP support
919 CONFIG_CMD_BSP * Board specific commands
920 CONFIG_CMD_BOOTD bootd
921 CONFIG_CMD_CACHE * icache, dcache
922 CONFIG_CMD_CLK * clock command support
923 CONFIG_CMD_CONSOLE coninfo
924 CONFIG_CMD_CRC32 * crc32
925 CONFIG_CMD_DATE * support for RTC, date/time...
926 CONFIG_CMD_DHCP * DHCP support
927 CONFIG_CMD_DIAG * Diagnostics
928 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
929 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
930 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
931 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
932 CONFIG_CMD_DTT * Digital Therm and Thermostat
933 CONFIG_CMD_ECHO echo arguments
934 CONFIG_CMD_EDITENV edit env variable
935 CONFIG_CMD_EEPROM * EEPROM read/write support
936 CONFIG_CMD_ELF * bootelf, bootvx
937 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
938 CONFIG_CMD_ENV_FLAGS * display details about env flags
939 CONFIG_CMD_ENV_EXISTS * check existence of env variable
940 CONFIG_CMD_EXPORTENV * export the environment
941 CONFIG_CMD_EXT2 * ext2 command support
942 CONFIG_CMD_EXT4 * ext4 command support
943 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
944 that work for multiple fs types
945 CONFIG_CMD_SAVEENV saveenv
946 CONFIG_CMD_FDC * Floppy Disk Support
947 CONFIG_CMD_FAT * FAT command support
948 CONFIG_CMD_FLASH flinfo, erase, protect
949 CONFIG_CMD_FPGA FPGA device initialization support
950 CONFIG_CMD_FUSE * Device fuse support
951 CONFIG_CMD_GETTIME * Get time since boot
952 CONFIG_CMD_GO * the 'go' command (exec code)
953 CONFIG_CMD_GREPENV * search environment
954 CONFIG_CMD_HASH * calculate hash / digest
955 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
956 CONFIG_CMD_I2C * I2C serial bus support
957 CONFIG_CMD_IDE * IDE harddisk support
958 CONFIG_CMD_IMI iminfo
959 CONFIG_CMD_IMLS List all images found in NOR flash
960 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
961 CONFIG_CMD_IMMAP * IMMR dump support
962 CONFIG_CMD_IMPORTENV * import an environment
963 CONFIG_CMD_INI * import data from an ini file into the env
964 CONFIG_CMD_IRQ * irqinfo
965 CONFIG_CMD_ITEST Integer/string test of 2 values
966 CONFIG_CMD_JFFS2 * JFFS2 Support
967 CONFIG_CMD_KGDB * kgdb
968 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
969 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
971 CONFIG_CMD_LOADB loadb
972 CONFIG_CMD_LOADS loads
973 CONFIG_CMD_MD5SUM * print md5 message digest
974 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
975 CONFIG_CMD_MEMINFO * Display detailed memory information
976 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
978 CONFIG_CMD_MEMTEST * mtest
979 CONFIG_CMD_MISC Misc functions like sleep etc
980 CONFIG_CMD_MMC * MMC memory mapped support
981 CONFIG_CMD_MII * MII utility commands
982 CONFIG_CMD_MTDPARTS * MTD partition support
983 CONFIG_CMD_NAND * NAND support
984 CONFIG_CMD_NET bootp, tftpboot, rarpboot
985 CONFIG_CMD_NFS NFS support
986 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
987 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
988 CONFIG_CMD_PCI * pciinfo
989 CONFIG_CMD_PCMCIA * PCMCIA support
990 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
992 CONFIG_CMD_PORTIO * Port I/O
993 CONFIG_CMD_READ * Read raw data from partition
994 CONFIG_CMD_REGINFO * Register dump
995 CONFIG_CMD_RUN run command in env variable
996 CONFIG_CMD_SANDBOX * sb command to access sandbox features
997 CONFIG_CMD_SAVES * save S record dump
998 CONFIG_CMD_SCSI * SCSI Support
999 CONFIG_CMD_SDRAM * print SDRAM configuration information
1000 (requires CONFIG_CMD_I2C)
1001 CONFIG_CMD_SETGETDCR Support for DCR Register access
1003 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1004 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1005 (requires CONFIG_CMD_MEMORY)
1006 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1007 CONFIG_CMD_SOURCE "source" command Support
1008 CONFIG_CMD_SPI * SPI serial bus support
1009 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1010 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1011 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1012 CONFIG_CMD_TIMER * access to the system tick timer
1013 CONFIG_CMD_USB * USB support
1014 CONFIG_CMD_CDP * Cisco Discover Protocol support
1015 CONFIG_CMD_MFSL * Microblaze FSL support
1016 CONFIG_CMD_XIMG Load part of Multi Image
1017 CONFIG_CMD_UUID * Generate random UUID or GUID string
1019 EXAMPLE: If you want all functions except of network
1020 support you can write:
1022 #include "config_cmd_all.h"
1023 #undef CONFIG_CMD_NET
1026 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1028 Note: Don't enable the "icache" and "dcache" commands
1029 (configuration option CONFIG_CMD_CACHE) unless you know
1030 what you (and your U-Boot users) are doing. Data
1031 cache cannot be enabled on systems like the 8xx or
1032 8260 (where accesses to the IMMR region must be
1033 uncached), and it cannot be disabled on all other
1034 systems where we (mis-) use the data cache to hold an
1035 initial stack and some data.
1038 XXX - this list needs to get updated!
1040 - Regular expression support:
1042 If this variable is defined, U-Boot is linked against
1043 the SLRE (Super Light Regular Expression) library,
1044 which adds regex support to some commands, as for
1045 example "env grep" and "setexpr".
1049 If this variable is defined, U-Boot will use a device tree
1050 to configure its devices, instead of relying on statically
1051 compiled #defines in the board file. This option is
1052 experimental and only available on a few boards. The device
1053 tree is available in the global data as gd->fdt_blob.
1055 U-Boot needs to get its device tree from somewhere. This can
1056 be done using one of the two options below:
1059 If this variable is defined, U-Boot will embed a device tree
1060 binary in its image. This device tree file should be in the
1061 board directory and called <soc>-<board>.dts. The binary file
1062 is then picked up in board_init_f() and made available through
1063 the global data structure as gd->blob.
1066 If this variable is defined, U-Boot will build a device tree
1067 binary. It will be called u-boot.dtb. Architecture-specific
1068 code will locate it at run-time. Generally this works by:
1070 cat u-boot.bin u-boot.dtb >image.bin
1072 and in fact, U-Boot does this for you, creating a file called
1073 u-boot-dtb.bin which is useful in the common case. You can
1074 still use the individual files if you need something more
1079 If this variable is defined, it enables watchdog
1080 support for the SoC. There must be support in the SoC
1081 specific code for a watchdog. For the 8xx and 8260
1082 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1083 register. When supported for a specific SoC is
1084 available, then no further board specific code should
1085 be needed to use it.
1088 When using a watchdog circuitry external to the used
1089 SoC, then define this variable and provide board
1090 specific code for the "hw_watchdog_reset" function.
1093 CONFIG_VERSION_VARIABLE
1094 If this variable is defined, an environment variable
1095 named "ver" is created by U-Boot showing the U-Boot
1096 version as printed by the "version" command.
1097 Any change to this variable will be reverted at the
1102 When CONFIG_CMD_DATE is selected, the type of the RTC
1103 has to be selected, too. Define exactly one of the
1106 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1107 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1108 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1109 CONFIG_RTC_MC146818 - use MC146818 RTC
1110 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1111 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1112 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1113 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1114 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1115 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1116 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1117 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1120 Note that if the RTC uses I2C, then the I2C interface
1121 must also be configured. See I2C Support, below.
1124 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1126 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1127 chip-ngpio pairs that tell the PCA953X driver the number of
1128 pins supported by a particular chip.
1130 Note that if the GPIO device uses I2C, then the I2C interface
1131 must also be configured. See I2C Support, below.
1133 - Timestamp Support:
1135 When CONFIG_TIMESTAMP is selected, the timestamp
1136 (date and time) of an image is printed by image
1137 commands like bootm or iminfo. This option is
1138 automatically enabled when you select CONFIG_CMD_DATE .
1140 - Partition Labels (disklabels) Supported:
1141 Zero or more of the following:
1142 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1143 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1144 Intel architecture, USB sticks, etc.
1145 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1146 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1147 bootloader. Note 2TB partition limit; see
1149 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1151 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1152 CONFIG_CMD_SCSI) you must configure support for at
1153 least one non-MTD partition type as well.
1156 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1157 board configurations files but used nowhere!
1159 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1160 be performed by calling the function
1161 ide_set_reset(int reset)
1162 which has to be defined in a board specific file
1167 Set this to enable ATAPI support.
1172 Set this to enable support for disks larger than 137GB
1173 Also look at CONFIG_SYS_64BIT_LBA.
1174 Whithout these , LBA48 support uses 32bit variables and will 'only'
1175 support disks up to 2.1TB.
1177 CONFIG_SYS_64BIT_LBA:
1178 When enabled, makes the IDE subsystem use 64bit sector addresses.
1182 At the moment only there is only support for the
1183 SYM53C8XX SCSI controller; define
1184 CONFIG_SCSI_SYM53C8XX to enable it.
1186 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1187 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1188 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1189 maximum numbers of LUNs, SCSI ID's and target
1191 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1193 The environment variable 'scsidevs' is set to the number of
1194 SCSI devices found during the last scan.
1196 - NETWORK Support (PCI):
1198 Support for Intel 8254x/8257x gigabit chips.
1201 Utility code for direct access to the SPI bus on Intel 8257x.
1202 This does not do anything useful unless you set at least one
1203 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1205 CONFIG_E1000_SPI_GENERIC
1206 Allow generic access to the SPI bus on the Intel 8257x, for
1207 example with the "sspi" command.
1210 Management command for E1000 devices. When used on devices
1211 with SPI support you can reprogram the EEPROM from U-Boot.
1213 CONFIG_E1000_FALLBACK_MAC
1214 default MAC for empty EEPROM after production.
1217 Support for Intel 82557/82559/82559ER chips.
1218 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1219 write routine for first time initialisation.
1222 Support for Digital 2114x chips.
1223 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1224 modem chip initialisation (KS8761/QS6611).
1227 Support for National dp83815 chips.
1230 Support for National dp8382[01] gigabit chips.
1232 - NETWORK Support (other):
1234 CONFIG_DRIVER_AT91EMAC
1235 Support for AT91RM9200 EMAC.
1238 Define this to use reduced MII inteface
1240 CONFIG_DRIVER_AT91EMAC_QUIET
1241 If this defined, the driver is quiet.
1242 The driver doen't show link status messages.
1244 CONFIG_CALXEDA_XGMAC
1245 Support for the Calxeda XGMAC device
1248 Support for SMSC's LAN91C96 chips.
1250 CONFIG_LAN91C96_BASE
1251 Define this to hold the physical address
1252 of the LAN91C96's I/O space
1254 CONFIG_LAN91C96_USE_32_BIT
1255 Define this to enable 32 bit addressing
1258 Support for SMSC's LAN91C111 chip
1260 CONFIG_SMC91111_BASE
1261 Define this to hold the physical address
1262 of the device (I/O space)
1264 CONFIG_SMC_USE_32_BIT
1265 Define this if data bus is 32 bits
1267 CONFIG_SMC_USE_IOFUNCS
1268 Define this to use i/o functions instead of macros
1269 (some hardware wont work with macros)
1271 CONFIG_DRIVER_TI_EMAC
1272 Support for davinci emac
1274 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1275 Define this if you have more then 3 PHYs.
1278 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1280 CONFIG_FTGMAC100_EGIGA
1281 Define this to use GE link update with gigabit PHY.
1282 Define this if FTGMAC100 is connected to gigabit PHY.
1283 If your system has 10/100 PHY only, it might not occur
1284 wrong behavior. Because PHY usually return timeout or
1285 useless data when polling gigabit status and gigabit
1286 control registers. This behavior won't affect the
1287 correctnessof 10/100 link speed update.
1290 Support for SMSC's LAN911x and LAN921x chips
1293 Define this to hold the physical address
1294 of the device (I/O space)
1296 CONFIG_SMC911X_32_BIT
1297 Define this if data bus is 32 bits
1299 CONFIG_SMC911X_16_BIT
1300 Define this if data bus is 16 bits. If your processor
1301 automatically converts one 32 bit word to two 16 bit
1302 words you may also try CONFIG_SMC911X_32_BIT.
1305 Support for Renesas on-chip Ethernet controller
1307 CONFIG_SH_ETHER_USE_PORT
1308 Define the number of ports to be used
1310 CONFIG_SH_ETHER_PHY_ADDR
1311 Define the ETH PHY's address
1313 CONFIG_SH_ETHER_CACHE_WRITEBACK
1314 If this option is set, the driver enables cache flush.
1318 Support TPM devices.
1321 Support for i2c bus TPM devices. Only one device
1322 per system is supported at this time.
1324 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1325 Define the the i2c bus number for the TPM device
1327 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1328 Define the TPM's address on the i2c bus
1330 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1331 Define the burst count bytes upper limit
1333 CONFIG_TPM_ATMEL_TWI
1334 Support for Atmel TWI TPM device. Requires I2C support.
1337 Support for generic parallel port TPM devices. Only one device
1338 per system is supported at this time.
1340 CONFIG_TPM_TIS_BASE_ADDRESS
1341 Base address where the generic TPM device is mapped
1342 to. Contemporary x86 systems usually map it at
1346 Add tpm monitor functions.
1347 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1348 provides monitor access to authorized functions.
1351 Define this to enable the TPM support library which provides
1352 functional interfaces to some TPM commands.
1353 Requires support for a TPM device.
1355 CONFIG_TPM_AUTH_SESSIONS
1356 Define this to enable authorized functions in the TPM library.
1357 Requires CONFIG_TPM and CONFIG_SHA1.
1360 At the moment only the UHCI host controller is
1361 supported (PIP405, MIP405, MPC5200); define
1362 CONFIG_USB_UHCI to enable it.
1363 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1364 and define CONFIG_USB_STORAGE to enable the USB
1367 Supported are USB Keyboards and USB Floppy drives
1369 MPC5200 USB requires additional defines:
1371 for 528 MHz Clock: 0x0001bbbb
1375 for differential drivers: 0x00001000
1376 for single ended drivers: 0x00005000
1377 for differential drivers on PSC3: 0x00000100
1378 for single ended drivers on PSC3: 0x00004100
1379 CONFIG_SYS_USB_EVENT_POLL
1380 May be defined to allow interrupt polling
1381 instead of using asynchronous interrupts
1383 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1384 txfilltuning field in the EHCI controller on reset.
1386 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1387 interval for usb hub power-on delay.(minimum 100msec)
1390 Define the below if you wish to use the USB console.
1391 Once firmware is rebuilt from a serial console issue the
1392 command "setenv stdin usbtty; setenv stdout usbtty" and
1393 attach your USB cable. The Unix command "dmesg" should print
1394 it has found a new device. The environment variable usbtty
1395 can be set to gserial or cdc_acm to enable your device to
1396 appear to a USB host as a Linux gserial device or a
1397 Common Device Class Abstract Control Model serial device.
1398 If you select usbtty = gserial you should be able to enumerate
1400 # modprobe usbserial vendor=0xVendorID product=0xProductID
1401 else if using cdc_acm, simply setting the environment
1402 variable usbtty to be cdc_acm should suffice. The following
1403 might be defined in YourBoardName.h
1406 Define this to build a UDC device
1409 Define this to have a tty type of device available to
1410 talk to the UDC device
1413 Define this to enable the high speed support for usb
1414 device and usbtty. If this feature is enabled, a routine
1415 int is_usbd_high_speed(void)
1416 also needs to be defined by the driver to dynamically poll
1417 whether the enumeration has succeded at high speed or full
1420 CONFIG_SYS_CONSOLE_IS_IN_ENV
1421 Define this if you want stdin, stdout &/or stderr to
1425 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1426 Derive USB clock from external clock "blah"
1427 - CONFIG_SYS_USB_EXTC_CLK 0x02
1429 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1430 Derive USB clock from brgclk
1431 - CONFIG_SYS_USB_BRG_CLK 0x04
1433 If you have a USB-IF assigned VendorID then you may wish to
1434 define your own vendor specific values either in BoardName.h
1435 or directly in usbd_vendor_info.h. If you don't define
1436 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1437 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1438 should pretend to be a Linux device to it's target host.
1440 CONFIG_USBD_MANUFACTURER
1441 Define this string as the name of your company for
1442 - CONFIG_USBD_MANUFACTURER "my company"
1444 CONFIG_USBD_PRODUCT_NAME
1445 Define this string as the name of your product
1446 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1448 CONFIG_USBD_VENDORID
1449 Define this as your assigned Vendor ID from the USB
1450 Implementors Forum. This *must* be a genuine Vendor ID
1451 to avoid polluting the USB namespace.
1452 - CONFIG_USBD_VENDORID 0xFFFF
1454 CONFIG_USBD_PRODUCTID
1455 Define this as the unique Product ID
1457 - CONFIG_USBD_PRODUCTID 0xFFFF
1459 Some USB device drivers may need to check USB cable attachment.
1460 In this case you can enable following config in BoardName.h:
1461 CONFIG_USB_CABLE_CHECK
1462 This enables function definition:
1463 - usb_cable_connected() in include/usb.h
1464 Implementation of this function is board-specific.
1466 - ULPI Layer Support:
1467 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1468 the generic ULPI layer. The generic layer accesses the ULPI PHY
1469 via the platform viewport, so you need both the genric layer and
1470 the viewport enabled. Currently only Chipidea/ARC based
1471 viewport is supported.
1472 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1473 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1474 If your ULPI phy needs a different reference clock than the
1475 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1476 the appropriate value in Hz.
1479 The MMC controller on the Intel PXA is supported. To
1480 enable this define CONFIG_MMC. The MMC can be
1481 accessed from the boot prompt by mapping the device
1482 to physical memory similar to flash. Command line is
1483 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1484 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1487 Support for Renesas on-chip MMCIF controller
1489 CONFIG_SH_MMCIF_ADDR
1490 Define the base address of MMCIF registers
1493 Define the clock frequency for MMCIF
1495 - USB Device Firmware Update (DFU) class support:
1497 This enables the USB portion of the DFU USB class
1500 This enables the command "dfu" which is used to have
1501 U-Boot create a DFU class device via USB. This command
1502 requires that the "dfu_alt_info" environment variable be
1503 set and define the alt settings to expose to the host.
1506 This enables support for exposing (e)MMC devices via DFU.
1509 This enables support for exposing NAND devices via DFU.
1512 This enables support for exposing RAM via DFU.
1513 Note: DFU spec refer to non-volatile memory usage, but
1514 allow usages beyond the scope of spec - here RAM usage,
1515 one that would help mostly the developer.
1517 CONFIG_SYS_DFU_DATA_BUF_SIZE
1518 Dfu transfer uses a buffer before writing data to the
1519 raw storage device. Make the size (in bytes) of this buffer
1520 configurable. The size of this buffer is also configurable
1521 through the "dfu_bufsiz" environment variable.
1523 CONFIG_SYS_DFU_MAX_FILE_SIZE
1524 When updating files rather than the raw storage device,
1525 we use a static buffer to copy the file into and then write
1526 the buffer once we've been given the whole file. Define
1527 this to the maximum filesize (in bytes) for the buffer.
1528 Default is 4 MiB if undefined.
1530 DFU_DEFAULT_POLL_TIMEOUT
1531 Poll timeout [ms], is the timeout a device can send to the
1532 host. The host must wait for this timeout before sending
1533 a subsequent DFU_GET_STATUS request to the device.
1535 DFU_MANIFEST_POLL_TIMEOUT
1536 Poll timeout [ms], which the device sends to the host when
1537 entering dfuMANIFEST state. Host waits this timeout, before
1538 sending again an USB request to the device.
1540 - Journaling Flash filesystem support:
1541 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1542 CONFIG_JFFS2_NAND_DEV
1543 Define these for a default partition on a NAND device
1545 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1546 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1547 Define these for a default partition on a NOR device
1549 CONFIG_SYS_JFFS_CUSTOM_PART
1550 Define this to create an own partition. You have to provide a
1551 function struct part_info* jffs2_part_info(int part_num)
1553 If you define only one JFFS2 partition you may also want to
1554 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1555 to disable the command chpart. This is the default when you
1556 have not defined a custom partition
1558 - FAT(File Allocation Table) filesystem write function support:
1561 Define this to enable support for saving memory data as a
1562 file in FAT formatted partition.
1564 This will also enable the command "fatwrite" enabling the
1565 user to write files to FAT.
1567 CBFS (Coreboot Filesystem) support
1570 Define this to enable support for reading from a Coreboot
1571 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1577 Define this to enable standard (PC-Style) keyboard
1581 Standard PC keyboard driver with US (is default) and
1582 GERMAN key layout (switch via environment 'keymap=de') support.
1583 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1584 for cfb_console. Supports cursor blinking.
1587 Enables a Chrome OS keyboard using the CROS_EC interface.
1588 This uses CROS_EC to communicate with a second microcontroller
1589 which provides key scans on request.
1594 Define this to enable video support (for output to
1597 CONFIG_VIDEO_CT69000
1599 Enable Chips & Technologies 69000 Video chip
1601 CONFIG_VIDEO_SMI_LYNXEM
1602 Enable Silicon Motion SMI 712/710/810 Video chip. The
1603 video output is selected via environment 'videoout'
1604 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1607 For the CT69000 and SMI_LYNXEM drivers, videomode is
1608 selected via environment 'videomode'. Two different ways
1610 - "videomode=num" 'num' is a standard LiLo mode numbers.
1611 Following standard modes are supported (* is default):
1613 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1614 -------------+---------------------------------------------
1615 8 bits | 0x301* 0x303 0x305 0x161 0x307
1616 15 bits | 0x310 0x313 0x316 0x162 0x319
1617 16 bits | 0x311 0x314 0x317 0x163 0x31A
1618 24 bits | 0x312 0x315 0x318 ? 0x31B
1619 -------------+---------------------------------------------
1620 (i.e. setenv videomode 317; saveenv; reset;)
1622 - "videomode=bootargs" all the video parameters are parsed
1623 from the bootargs. (See drivers/video/videomodes.c)
1626 CONFIG_VIDEO_SED13806
1627 Enable Epson SED13806 driver. This driver supports 8bpp
1628 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1629 or CONFIG_VIDEO_SED13806_16BPP
1632 Enable the Freescale DIU video driver. Reference boards for
1633 SOCs that have a DIU should define this macro to enable DIU
1634 support, and should also define these other macros:
1640 CONFIG_VIDEO_SW_CURSOR
1641 CONFIG_VGA_AS_SINGLE_DEVICE
1643 CONFIG_VIDEO_BMP_LOGO
1645 The DIU driver will look for the 'video-mode' environment
1646 variable, and if defined, enable the DIU as a console during
1647 boot. See the documentation file README.video for a
1648 description of this variable.
1652 Enable the VGA video / BIOS for x86. The alternative if you
1653 are using coreboot is to use the coreboot frame buffer
1660 Define this to enable a custom keyboard support.
1661 This simply calls drv_keyboard_init() which must be
1662 defined in your board-specific files.
1663 The only board using this so far is RBC823.
1665 - LCD Support: CONFIG_LCD
1667 Define this to enable LCD support (for output to LCD
1668 display); also select one of the supported displays
1669 by defining one of these:
1673 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1675 CONFIG_NEC_NL6448AC33:
1677 NEC NL6448AC33-18. Active, color, single scan.
1679 CONFIG_NEC_NL6448BC20
1681 NEC NL6448BC20-08. 6.5", 640x480.
1682 Active, color, single scan.
1684 CONFIG_NEC_NL6448BC33_54
1686 NEC NL6448BC33-54. 10.4", 640x480.
1687 Active, color, single scan.
1691 Sharp 320x240. Active, color, single scan.
1692 It isn't 16x9, and I am not sure what it is.
1694 CONFIG_SHARP_LQ64D341
1696 Sharp LQ64D341 display, 640x480.
1697 Active, color, single scan.
1701 HLD1045 display, 640x480.
1702 Active, color, single scan.
1706 Optrex CBL50840-2 NF-FW 99 22 M5
1708 Hitachi LMG6912RPFC-00T
1712 320x240. Black & white.
1714 Normally display is black on white background; define
1715 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1717 CONFIG_LCD_ALIGNMENT
1719 Normally the LCD is page-aligned (tyically 4KB). If this is
1720 defined then the LCD will be aligned to this value instead.
1721 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1722 here, since it is cheaper to change data cache settings on
1723 a per-section basis.
1725 CONFIG_CONSOLE_SCROLL_LINES
1727 When the console need to be scrolled, this is the number of
1728 lines to scroll by. It defaults to 1. Increasing this makes
1729 the console jump but can help speed up operation when scrolling
1734 Support drawing of RLE8-compressed bitmaps on the LCD.
1738 Enables an 'i2c edid' command which can read EDID
1739 information over I2C from an attached LCD display.
1741 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1743 If this option is set, the environment is checked for
1744 a variable "splashimage". If found, the usual display
1745 of logo, copyright and system information on the LCD
1746 is suppressed and the BMP image at the address
1747 specified in "splashimage" is loaded instead. The
1748 console is redirected to the "nulldev", too. This
1749 allows for a "silent" boot where a splash screen is
1750 loaded very quickly after power-on.
1752 CONFIG_SPLASHIMAGE_GUARD
1754 If this option is set, then U-Boot will prevent the environment
1755 variable "splashimage" from being set to a problematic address
1756 (see README.displaying-bmps).
1757 This option is useful for targets where, due to alignment
1758 restrictions, an improperly aligned BMP image will cause a data
1759 abort. If you think you will not have problems with unaligned
1760 accesses (for example because your toolchain prevents them)
1761 there is no need to set this option.
1763 CONFIG_SPLASH_SCREEN_ALIGN
1765 If this option is set the splash image can be freely positioned
1766 on the screen. Environment variable "splashpos" specifies the
1767 position as "x,y". If a positive number is given it is used as
1768 number of pixel from left/top. If a negative number is given it
1769 is used as number of pixel from right/bottom. You can also
1770 specify 'm' for centering the image.
1773 setenv splashpos m,m
1774 => image at center of screen
1776 setenv splashpos 30,20
1777 => image at x = 30 and y = 20
1779 setenv splashpos -10,m
1780 => vertically centered image
1781 at x = dspWidth - bmpWidth - 9
1783 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1785 If this option is set, additionally to standard BMP
1786 images, gzipped BMP images can be displayed via the
1787 splashscreen support or the bmp command.
1789 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1791 If this option is set, 8-bit RLE compressed BMP images
1792 can be displayed via the splashscreen support or the
1795 - Do compresssing for memory range:
1798 If this option is set, it would use zlib deflate method
1799 to compress the specified memory at its best effort.
1801 - Compression support:
1804 Enabled by default to support gzip compressed images.
1808 If this option is set, support for bzip2 compressed
1809 images is included. If not, only uncompressed and gzip
1810 compressed images are supported.
1812 NOTE: the bzip2 algorithm requires a lot of RAM, so
1813 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1818 If this option is set, support for lzma compressed
1821 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1822 requires an amount of dynamic memory that is given by the
1825 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1827 Where lc and lp stand for, respectively, Literal context bits
1828 and Literal pos bits.
1830 This value is upper-bounded by 14MB in the worst case. Anyway,
1831 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1832 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1833 a very small buffer.
1835 Use the lzmainfo tool to determinate the lc and lp values and
1836 then calculate the amount of needed dynamic memory (ensuring
1837 the appropriate CONFIG_SYS_MALLOC_LEN value).
1841 If this option is set, support for LZO compressed images
1847 The address of PHY on MII bus.
1849 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1851 The clock frequency of the MII bus
1855 If this option is set, support for speed/duplex
1856 detection of gigabit PHY is included.
1858 CONFIG_PHY_RESET_DELAY
1860 Some PHY like Intel LXT971A need extra delay after
1861 reset before any MII register access is possible.
1862 For such PHY, set this option to the usec delay
1863 required. (minimum 300usec for LXT971A)
1865 CONFIG_PHY_CMD_DELAY (ppc4xx)
1867 Some PHY like Intel LXT971A need extra delay after
1868 command issued before MII status register can be read
1878 Define a default value for Ethernet address to use
1879 for the respective Ethernet interface, in case this
1880 is not determined automatically.
1885 Define a default value for the IP address to use for
1886 the default Ethernet interface, in case this is not
1887 determined through e.g. bootp.
1888 (Environment variable "ipaddr")
1890 - Server IP address:
1893 Defines a default value for the IP address of a TFTP
1894 server to contact when using the "tftboot" command.
1895 (Environment variable "serverip")
1897 CONFIG_KEEP_SERVERADDR
1899 Keeps the server's MAC address, in the env 'serveraddr'
1900 for passing to bootargs (like Linux's netconsole option)
1902 - Gateway IP address:
1905 Defines a default value for the IP address of the
1906 default router where packets to other networks are
1908 (Environment variable "gatewayip")
1913 Defines a default value for the subnet mask (or
1914 routing prefix) which is used to determine if an IP
1915 address belongs to the local subnet or needs to be
1916 forwarded through a router.
1917 (Environment variable "netmask")
1919 - Multicast TFTP Mode:
1922 Defines whether you want to support multicast TFTP as per
1923 rfc-2090; for example to work with atftp. Lets lots of targets
1924 tftp down the same boot image concurrently. Note: the Ethernet
1925 driver in use must provide a function: mcast() to join/leave a
1928 - BOOTP Recovery Mode:
1929 CONFIG_BOOTP_RANDOM_DELAY
1931 If you have many targets in a network that try to
1932 boot using BOOTP, you may want to avoid that all
1933 systems send out BOOTP requests at precisely the same
1934 moment (which would happen for instance at recovery
1935 from a power failure, when all systems will try to
1936 boot, thus flooding the BOOTP server. Defining
1937 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1938 inserted before sending out BOOTP requests. The
1939 following delays are inserted then:
1941 1st BOOTP request: delay 0 ... 1 sec
1942 2nd BOOTP request: delay 0 ... 2 sec
1943 3rd BOOTP request: delay 0 ... 4 sec
1945 BOOTP requests: delay 0 ... 8 sec
1947 - DHCP Advanced Options:
1948 You can fine tune the DHCP functionality by defining
1949 CONFIG_BOOTP_* symbols:
1951 CONFIG_BOOTP_SUBNETMASK
1952 CONFIG_BOOTP_GATEWAY
1953 CONFIG_BOOTP_HOSTNAME
1954 CONFIG_BOOTP_NISDOMAIN
1955 CONFIG_BOOTP_BOOTPATH
1956 CONFIG_BOOTP_BOOTFILESIZE
1959 CONFIG_BOOTP_SEND_HOSTNAME
1960 CONFIG_BOOTP_NTPSERVER
1961 CONFIG_BOOTP_TIMEOFFSET
1962 CONFIG_BOOTP_VENDOREX
1963 CONFIG_BOOTP_MAY_FAIL
1965 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1966 environment variable, not the BOOTP server.
1968 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1969 after the configured retry count, the call will fail
1970 instead of starting over. This can be used to fail over
1971 to Link-local IP address configuration if the DHCP server
1974 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1975 serverip from a DHCP server, it is possible that more
1976 than one DNS serverip is offered to the client.
1977 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1978 serverip will be stored in the additional environment
1979 variable "dnsip2". The first DNS serverip is always
1980 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1983 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1984 to do a dynamic update of a DNS server. To do this, they
1985 need the hostname of the DHCP requester.
1986 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1987 of the "hostname" environment variable is passed as
1988 option 12 to the DHCP server.
1990 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1992 A 32bit value in microseconds for a delay between
1993 receiving a "DHCP Offer" and sending the "DHCP Request".
1994 This fixes a problem with certain DHCP servers that don't
1995 respond 100% of the time to a "DHCP request". E.g. On an
1996 AT91RM9200 processor running at 180MHz, this delay needed
1997 to be *at least* 15,000 usec before a Windows Server 2003
1998 DHCP server would reply 100% of the time. I recommend at
1999 least 50,000 usec to be safe. The alternative is to hope
2000 that one of the retries will be successful but note that
2001 the DHCP timeout and retry process takes a longer than
2004 - Link-local IP address negotiation:
2005 Negotiate with other link-local clients on the local network
2006 for an address that doesn't require explicit configuration.
2007 This is especially useful if a DHCP server cannot be guaranteed
2008 to exist in all environments that the device must operate.
2010 See doc/README.link-local for more information.
2013 CONFIG_CDP_DEVICE_ID
2015 The device id used in CDP trigger frames.
2017 CONFIG_CDP_DEVICE_ID_PREFIX
2019 A two character string which is prefixed to the MAC address
2024 A printf format string which contains the ascii name of
2025 the port. Normally is set to "eth%d" which sets
2026 eth0 for the first Ethernet, eth1 for the second etc.
2028 CONFIG_CDP_CAPABILITIES
2030 A 32bit integer which indicates the device capabilities;
2031 0x00000010 for a normal host which does not forwards.
2035 An ascii string containing the version of the software.
2039 An ascii string containing the name of the platform.
2043 A 32bit integer sent on the trigger.
2045 CONFIG_CDP_POWER_CONSUMPTION
2047 A 16bit integer containing the power consumption of the
2048 device in .1 of milliwatts.
2050 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2052 A byte containing the id of the VLAN.
2054 - Status LED: CONFIG_STATUS_LED
2056 Several configurations allow to display the current
2057 status using a LED. For instance, the LED will blink
2058 fast while running U-Boot code, stop blinking as
2059 soon as a reply to a BOOTP request was received, and
2060 start blinking slow once the Linux kernel is running
2061 (supported by a status LED driver in the Linux
2062 kernel). Defining CONFIG_STATUS_LED enables this
2068 The status LED can be connected to a GPIO pin.
2069 In such cases, the gpio_led driver can be used as a
2070 status LED backend implementation. Define CONFIG_GPIO_LED
2071 to include the gpio_led driver in the U-Boot binary.
2073 CONFIG_GPIO_LED_INVERTED_TABLE
2074 Some GPIO connected LEDs may have inverted polarity in which
2075 case the GPIO high value corresponds to LED off state and
2076 GPIO low value corresponds to LED on state.
2077 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2078 with a list of GPIO LEDs that have inverted polarity.
2080 - CAN Support: CONFIG_CAN_DRIVER
2082 Defining CONFIG_CAN_DRIVER enables CAN driver support
2083 on those systems that support this (optional)
2084 feature, like the TQM8xxL modules.
2086 - I2C Support: CONFIG_SYS_I2C
2088 This enable the NEW i2c subsystem, and will allow you to use
2089 i2c commands at the u-boot command line (as long as you set
2090 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2091 based realtime clock chips or other i2c devices. See
2092 common/cmd_i2c.c for a description of the command line
2095 ported i2c driver to the new framework:
2096 - drivers/i2c/soft_i2c.c:
2097 - activate first bus with CONFIG_SYS_I2C_SOFT define
2098 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2099 for defining speed and slave address
2100 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2101 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2102 for defining speed and slave address
2103 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2104 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2105 for defining speed and slave address
2106 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2107 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2108 for defining speed and slave address
2110 - drivers/i2c/fsl_i2c.c:
2111 - activate i2c driver with CONFIG_SYS_I2C_FSL
2112 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2113 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2114 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2116 - If your board supports a second fsl i2c bus, define
2117 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2118 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2119 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2122 - drivers/i2c/tegra_i2c.c:
2123 - activate this driver with CONFIG_SYS_I2C_TEGRA
2124 - This driver adds 4 i2c buses with a fix speed from
2125 100000 and the slave addr 0!
2127 - drivers/i2c/ppc4xx_i2c.c
2128 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2129 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2130 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2132 - drivers/i2c/i2c_mxc.c
2133 - activate this driver with CONFIG_SYS_I2C_MXC
2134 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2135 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2136 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2137 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2138 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2139 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2140 If thoses defines are not set, default value is 100000
2141 for speed, and 0 for slave.
2143 - drivers/i2c/rcar_i2c.c:
2144 - activate this driver with CONFIG_SYS_I2C_RCAR
2145 - This driver adds 4 i2c buses
2147 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2148 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2149 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2150 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2151 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2152 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2153 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2154 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2155 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2157 - drivers/i2c/sh_i2c.c:
2158 - activate this driver with CONFIG_SYS_I2C_SH
2159 - This driver adds from 2 to 5 i2c buses
2161 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2162 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2163 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2164 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2165 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2166 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2167 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2168 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2169 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2170 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2171 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2172 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2173 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2175 - drivers/i2c/omap24xx_i2c.c
2176 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2177 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2178 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2179 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2180 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2181 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2182 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2183 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2184 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2185 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2186 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2188 - drivers/i2c/zynq_i2c.c
2189 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2190 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2191 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2193 - drivers/i2c/s3c24x0_i2c.c:
2194 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2195 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2196 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2197 with a fix speed from 100000 and the slave addr 0!
2201 CONFIG_SYS_NUM_I2C_BUSES
2202 Hold the number of i2c busses you want to use. If you
2203 don't use/have i2c muxes on your i2c bus, this
2204 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2207 CONFIG_SYS_I2C_DIRECT_BUS
2208 define this, if you don't use i2c muxes on your hardware.
2209 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2212 CONFIG_SYS_I2C_MAX_HOPS
2213 define how many muxes are maximal consecutively connected
2214 on one i2c bus. If you not use i2c muxes, omit this
2217 CONFIG_SYS_I2C_BUSES
2218 hold a list of busses you want to use, only used if
2219 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2220 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2221 CONFIG_SYS_NUM_I2C_BUSES = 9:
2223 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2224 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2225 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2226 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2227 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2228 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2229 {1, {I2C_NULL_HOP}}, \
2230 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2231 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2235 bus 0 on adapter 0 without a mux
2236 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2237 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2238 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2239 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2240 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2241 bus 6 on adapter 1 without a mux
2242 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2243 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2245 If you do not have i2c muxes on your board, omit this define.
2247 - Legacy I2C Support: CONFIG_HARD_I2C
2249 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2250 provides the following compelling advantages:
2252 - more than one i2c adapter is usable
2253 - approved multibus support
2254 - better i2c mux support
2256 ** Please consider updating your I2C driver now. **
2258 These enable legacy I2C serial bus commands. Defining
2259 CONFIG_HARD_I2C will include the appropriate I2C driver
2260 for the selected CPU.
2262 This will allow you to use i2c commands at the u-boot
2263 command line (as long as you set CONFIG_CMD_I2C in
2264 CONFIG_COMMANDS) and communicate with i2c based realtime
2265 clock chips. See common/cmd_i2c.c for a description of the
2266 command line interface.
2268 CONFIG_HARD_I2C selects a hardware I2C controller.
2270 There are several other quantities that must also be
2271 defined when you define CONFIG_HARD_I2C.
2273 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2274 to be the frequency (in Hz) at which you wish your i2c bus
2275 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2276 the CPU's i2c node address).
2278 Now, the u-boot i2c code for the mpc8xx
2279 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2280 and so its address should therefore be cleared to 0 (See,
2281 eg, MPC823e User's Manual p.16-473). So, set
2282 CONFIG_SYS_I2C_SLAVE to 0.
2284 CONFIG_SYS_I2C_INIT_MPC5XXX
2286 When a board is reset during an i2c bus transfer
2287 chips might think that the current transfer is still
2288 in progress. Reset the slave devices by sending start
2289 commands until the slave device responds.
2291 That's all that's required for CONFIG_HARD_I2C.
2293 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2294 then the following macros need to be defined (examples are
2295 from include/configs/lwmon.h):
2299 (Optional). Any commands necessary to enable the I2C
2300 controller or configure ports.
2302 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2306 (Only for MPC8260 CPU). The I/O port to use (the code
2307 assumes both bits are on the same port). Valid values
2308 are 0..3 for ports A..D.
2312 The code necessary to make the I2C data line active
2313 (driven). If the data line is open collector, this
2316 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2320 The code necessary to make the I2C data line tri-stated
2321 (inactive). If the data line is open collector, this
2324 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2328 Code that returns true if the I2C data line is high,
2331 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2335 If <bit> is true, sets the I2C data line high. If it
2336 is false, it clears it (low).
2338 eg: #define I2C_SDA(bit) \
2339 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2340 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2344 If <bit> is true, sets the I2C clock line high. If it
2345 is false, it clears it (low).
2347 eg: #define I2C_SCL(bit) \
2348 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2349 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2353 This delay is invoked four times per clock cycle so this
2354 controls the rate of data transfer. The data rate thus
2355 is 1 / (I2C_DELAY * 4). Often defined to be something
2358 #define I2C_DELAY udelay(2)
2360 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2362 If your arch supports the generic GPIO framework (asm/gpio.h),
2363 then you may alternatively define the two GPIOs that are to be
2364 used as SCL / SDA. Any of the previous I2C_xxx macros will
2365 have GPIO-based defaults assigned to them as appropriate.
2367 You should define these to the GPIO value as given directly to
2368 the generic GPIO functions.
2370 CONFIG_SYS_I2C_INIT_BOARD
2372 When a board is reset during an i2c bus transfer
2373 chips might think that the current transfer is still
2374 in progress. On some boards it is possible to access
2375 the i2c SCLK line directly, either by using the
2376 processor pin as a GPIO or by having a second pin
2377 connected to the bus. If this option is defined a
2378 custom i2c_init_board() routine in boards/xxx/board.c
2379 is run early in the boot sequence.
2381 CONFIG_SYS_I2C_BOARD_LATE_INIT
2383 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2384 defined a custom i2c_board_late_init() routine in
2385 boards/xxx/board.c is run AFTER the operations in i2c_init()
2386 is completed. This callpoint can be used to unreset i2c bus
2387 using CPU i2c controller register accesses for CPUs whose i2c
2388 controller provide such a method. It is called at the end of
2389 i2c_init() to allow i2c_init operations to setup the i2c bus
2390 controller on the CPU (e.g. setting bus speed & slave address).
2392 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2394 This option enables configuration of bi_iic_fast[] flags
2395 in u-boot bd_info structure based on u-boot environment
2396 variable "i2cfast". (see also i2cfast)
2398 CONFIG_I2C_MULTI_BUS
2400 This option allows the use of multiple I2C buses, each of which
2401 must have a controller. At any point in time, only one bus is
2402 active. To switch to a different bus, use the 'i2c dev' command.
2403 Note that bus numbering is zero-based.
2405 CONFIG_SYS_I2C_NOPROBES
2407 This option specifies a list of I2C devices that will be skipped
2408 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2409 is set, specify a list of bus-device pairs. Otherwise, specify
2410 a 1D array of device addresses
2413 #undef CONFIG_I2C_MULTI_BUS
2414 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2416 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2418 #define CONFIG_I2C_MULTI_BUS
2419 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2421 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2423 CONFIG_SYS_SPD_BUS_NUM
2425 If defined, then this indicates the I2C bus number for DDR SPD.
2426 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2428 CONFIG_SYS_RTC_BUS_NUM
2430 If defined, then this indicates the I2C bus number for the RTC.
2431 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2433 CONFIG_SYS_DTT_BUS_NUM
2435 If defined, then this indicates the I2C bus number for the DTT.
2436 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2438 CONFIG_SYS_I2C_DTT_ADDR:
2440 If defined, specifies the I2C address of the DTT device.
2441 If not defined, then U-Boot uses predefined value for
2442 specified DTT device.
2444 CONFIG_SOFT_I2C_READ_REPEATED_START
2446 defining this will force the i2c_read() function in
2447 the soft_i2c driver to perform an I2C repeated start
2448 between writing the address pointer and reading the
2449 data. If this define is omitted the default behaviour
2450 of doing a stop-start sequence will be used. Most I2C
2451 devices can use either method, but some require one or
2454 - SPI Support: CONFIG_SPI
2456 Enables SPI driver (so far only tested with
2457 SPI EEPROM, also an instance works with Crystal A/D and
2458 D/As on the SACSng board)
2462 Enables the driver for SPI controller on SuperH. Currently
2463 only SH7757 is supported.
2467 Enables extended (16-bit) SPI EEPROM addressing.
2468 (symmetrical to CONFIG_I2C_X)
2472 Enables a software (bit-bang) SPI driver rather than
2473 using hardware support. This is a general purpose
2474 driver that only requires three general I/O port pins
2475 (two outputs, one input) to function. If this is
2476 defined, the board configuration must define several
2477 SPI configuration items (port pins to use, etc). For
2478 an example, see include/configs/sacsng.h.
2482 Enables a hardware SPI driver for general-purpose reads
2483 and writes. As with CONFIG_SOFT_SPI, the board configuration
2484 must define a list of chip-select function pointers.
2485 Currently supported on some MPC8xxx processors. For an
2486 example, see include/configs/mpc8349emds.h.
2490 Enables the driver for the SPI controllers on i.MX and MXC
2491 SoCs. Currently i.MX31/35/51 are supported.
2493 - FPGA Support: CONFIG_FPGA
2495 Enables FPGA subsystem.
2497 CONFIG_FPGA_<vendor>
2499 Enables support for specific chip vendors.
2502 CONFIG_FPGA_<family>
2504 Enables support for FPGA family.
2505 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2509 Specify the number of FPGA devices to support.
2511 CONFIG_SYS_FPGA_PROG_FEEDBACK
2513 Enable printing of hash marks during FPGA configuration.
2515 CONFIG_SYS_FPGA_CHECK_BUSY
2517 Enable checks on FPGA configuration interface busy
2518 status by the configuration function. This option
2519 will require a board or device specific function to
2524 If defined, a function that provides delays in the FPGA
2525 configuration driver.
2527 CONFIG_SYS_FPGA_CHECK_CTRLC
2528 Allow Control-C to interrupt FPGA configuration
2530 CONFIG_SYS_FPGA_CHECK_ERROR
2532 Check for configuration errors during FPGA bitfile
2533 loading. For example, abort during Virtex II
2534 configuration if the INIT_B line goes low (which
2535 indicated a CRC error).
2537 CONFIG_SYS_FPGA_WAIT_INIT
2539 Maximum time to wait for the INIT_B line to deassert
2540 after PROB_B has been deasserted during a Virtex II
2541 FPGA configuration sequence. The default time is 500
2544 CONFIG_SYS_FPGA_WAIT_BUSY
2546 Maximum time to wait for BUSY to deassert during
2547 Virtex II FPGA configuration. The default is 5 ms.
2549 CONFIG_SYS_FPGA_WAIT_CONFIG
2551 Time to wait after FPGA configuration. The default is
2554 - Configuration Management:
2557 If defined, this string will be added to the U-Boot
2558 version information (U_BOOT_VERSION)
2560 - Vendor Parameter Protection:
2562 U-Boot considers the values of the environment
2563 variables "serial#" (Board Serial Number) and
2564 "ethaddr" (Ethernet Address) to be parameters that
2565 are set once by the board vendor / manufacturer, and
2566 protects these variables from casual modification by
2567 the user. Once set, these variables are read-only,
2568 and write or delete attempts are rejected. You can
2569 change this behaviour:
2571 If CONFIG_ENV_OVERWRITE is #defined in your config
2572 file, the write protection for vendor parameters is
2573 completely disabled. Anybody can change or delete
2576 Alternatively, if you #define _both_ CONFIG_ETHADDR
2577 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2578 Ethernet address is installed in the environment,
2579 which can be changed exactly ONCE by the user. [The
2580 serial# is unaffected by this, i. e. it remains
2583 The same can be accomplished in a more flexible way
2584 for any variable by configuring the type of access
2585 to allow for those variables in the ".flags" variable
2586 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2591 Define this variable to enable the reservation of
2592 "protected RAM", i. e. RAM which is not overwritten
2593 by U-Boot. Define CONFIG_PRAM to hold the number of
2594 kB you want to reserve for pRAM. You can overwrite
2595 this default value by defining an environment
2596 variable "pram" to the number of kB you want to
2597 reserve. Note that the board info structure will
2598 still show the full amount of RAM. If pRAM is
2599 reserved, a new environment variable "mem" will
2600 automatically be defined to hold the amount of
2601 remaining RAM in a form that can be passed as boot
2602 argument to Linux, for instance like that:
2604 setenv bootargs ... mem=\${mem}
2607 This way you can tell Linux not to use this memory,
2608 either, which results in a memory region that will
2609 not be affected by reboots.
2611 *WARNING* If your board configuration uses automatic
2612 detection of the RAM size, you must make sure that
2613 this memory test is non-destructive. So far, the
2614 following board configurations are known to be
2617 IVMS8, IVML24, SPD8xx, TQM8xxL,
2618 HERMES, IP860, RPXlite, LWMON,
2621 - Access to physical memory region (> 4GB)
2622 Some basic support is provided for operations on memory not
2623 normally accessible to U-Boot - e.g. some architectures
2624 support access to more than 4GB of memory on 32-bit
2625 machines using physical address extension or similar.
2626 Define CONFIG_PHYSMEM to access this basic support, which
2627 currently only supports clearing the memory.
2632 Define this variable to stop the system in case of a
2633 fatal error, so that you have to reset it manually.
2634 This is probably NOT a good idea for an embedded
2635 system where you want the system to reboot
2636 automatically as fast as possible, but it may be
2637 useful during development since you can try to debug
2638 the conditions that lead to the situation.
2640 CONFIG_NET_RETRY_COUNT
2642 This variable defines the number of retries for
2643 network operations like ARP, RARP, TFTP, or BOOTP
2644 before giving up the operation. If not defined, a
2645 default value of 5 is used.
2649 Timeout waiting for an ARP reply in milliseconds.
2653 Timeout in milliseconds used in NFS protocol.
2654 If you encounter "ERROR: Cannot umount" in nfs command,
2655 try longer timeout such as
2656 #define CONFIG_NFS_TIMEOUT 10000UL
2658 - Command Interpreter:
2659 CONFIG_AUTO_COMPLETE
2661 Enable auto completion of commands using TAB.
2663 Note that this feature has NOT been implemented yet
2664 for the "hush" shell.
2667 CONFIG_SYS_HUSH_PARSER
2669 Define this variable to enable the "hush" shell (from
2670 Busybox) as command line interpreter, thus enabling
2671 powerful command line syntax like
2672 if...then...else...fi conditionals or `&&' and '||'
2673 constructs ("shell scripts").
2675 If undefined, you get the old, much simpler behaviour
2676 with a somewhat smaller memory footprint.
2679 CONFIG_SYS_PROMPT_HUSH_PS2
2681 This defines the secondary prompt string, which is
2682 printed when the command interpreter needs more input
2683 to complete a command. Usually "> ".
2687 In the current implementation, the local variables
2688 space and global environment variables space are
2689 separated. Local variables are those you define by
2690 simply typing `name=value'. To access a local
2691 variable later on, you have write `$name' or
2692 `${name}'; to execute the contents of a variable
2693 directly type `$name' at the command prompt.
2695 Global environment variables are those you use
2696 setenv/printenv to work with. To run a command stored
2697 in such a variable, you need to use the run command,
2698 and you must not use the '$' sign to access them.
2700 To store commands and special characters in a
2701 variable, please use double quotation marks
2702 surrounding the whole text of the variable, instead
2703 of the backslashes before semicolons and special
2706 - Commandline Editing and History:
2707 CONFIG_CMDLINE_EDITING
2709 Enable editing and History functions for interactive
2710 commandline input operations
2712 - Default Environment:
2713 CONFIG_EXTRA_ENV_SETTINGS
2715 Define this to contain any number of null terminated
2716 strings (variable = value pairs) that will be part of
2717 the default environment compiled into the boot image.
2719 For example, place something like this in your
2720 board's config file:
2722 #define CONFIG_EXTRA_ENV_SETTINGS \
2726 Warning: This method is based on knowledge about the
2727 internal format how the environment is stored by the
2728 U-Boot code. This is NOT an official, exported
2729 interface! Although it is unlikely that this format
2730 will change soon, there is no guarantee either.
2731 You better know what you are doing here.
2733 Note: overly (ab)use of the default environment is
2734 discouraged. Make sure to check other ways to preset
2735 the environment like the "source" command or the
2738 CONFIG_ENV_VARS_UBOOT_CONFIG
2740 Define this in order to add variables describing the
2741 U-Boot build configuration to the default environment.
2742 These will be named arch, cpu, board, vendor, and soc.
2744 Enabling this option will cause the following to be defined:
2752 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2754 Define this in order to add variables describing certain
2755 run-time determined information about the hardware to the
2756 environment. These will be named board_name, board_rev.
2758 CONFIG_DELAY_ENVIRONMENT
2760 Normally the environment is loaded when the board is
2761 intialised so that it is available to U-Boot. This inhibits
2762 that so that the environment is not available until
2763 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2764 this is instead controlled by the value of
2765 /config/load-environment.
2767 - DataFlash Support:
2768 CONFIG_HAS_DATAFLASH
2770 Defining this option enables DataFlash features and
2771 allows to read/write in Dataflash via the standard
2774 - Serial Flash support
2777 Defining this option enables SPI flash commands
2778 'sf probe/read/write/erase/update'.
2780 Usage requires an initial 'probe' to define the serial
2781 flash parameters, followed by read/write/erase/update
2784 The following defaults may be provided by the platform
2785 to handle the common case when only a single serial
2786 flash is present on the system.
2788 CONFIG_SF_DEFAULT_BUS Bus identifier
2789 CONFIG_SF_DEFAULT_CS Chip-select
2790 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2791 CONFIG_SF_DEFAULT_SPEED in Hz
2795 Define this option to include a destructive SPI flash
2798 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2800 Define this option to use the Bank addr/Extended addr
2801 support on SPI flashes which has size > 16Mbytes.
2803 CONFIG_SF_DUAL_FLASH Dual flash memories
2805 Define this option to use dual flash support where two flash
2806 memories can be connected with a given cs line.
2807 currently Xilinx Zynq qspi support these type of connections.
2809 - SystemACE Support:
2812 Adding this option adds support for Xilinx SystemACE
2813 chips attached via some sort of local bus. The address
2814 of the chip must also be defined in the
2815 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2817 #define CONFIG_SYSTEMACE
2818 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2820 When SystemACE support is added, the "ace" device type
2821 becomes available to the fat commands, i.e. fatls.
2823 - TFTP Fixed UDP Port:
2826 If this is defined, the environment variable tftpsrcp
2827 is used to supply the TFTP UDP source port value.
2828 If tftpsrcp isn't defined, the normal pseudo-random port
2829 number generator is used.
2831 Also, the environment variable tftpdstp is used to supply
2832 the TFTP UDP destination port value. If tftpdstp isn't
2833 defined, the normal port 69 is used.
2835 The purpose for tftpsrcp is to allow a TFTP server to
2836 blindly start the TFTP transfer using the pre-configured
2837 target IP address and UDP port. This has the effect of
2838 "punching through" the (Windows XP) firewall, allowing
2839 the remainder of the TFTP transfer to proceed normally.
2840 A better solution is to properly configure the firewall,
2841 but sometimes that is not allowed.
2846 This enables a generic 'hash' command which can produce
2847 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2851 Enable the hash verify command (hash -v). This adds to code
2854 CONFIG_SHA1 - support SHA1 hashing
2855 CONFIG_SHA256 - support SHA256 hashing
2857 Note: There is also a sha1sum command, which should perhaps
2858 be deprecated in favour of 'hash sha1'.
2860 - Freescale i.MX specific commands:
2861 CONFIG_CMD_HDMIDETECT
2862 This enables 'hdmidet' command which returns true if an
2863 HDMI monitor is detected. This command is i.MX 6 specific.
2866 This enables the 'bmode' (bootmode) command for forcing
2867 a boot from specific media.
2869 This is useful for forcing the ROM's usb downloader to
2870 activate upon a watchdog reset which is nice when iterating
2871 on U-Boot. Using the reset button or running bmode normal
2872 will set it back to normal. This command currently
2873 supports i.MX53 and i.MX6.
2878 This enables the RSA algorithm used for FIT image verification
2879 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2881 The signing part is build into mkimage regardless of this
2884 - bootcount support:
2885 CONFIG_BOOTCOUNT_LIMIT
2887 This enables the bootcounter support, see:
2888 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2891 enable special bootcounter support on at91sam9xe based boards.
2893 enable special bootcounter support on blackfin based boards.
2895 enable special bootcounter support on da850 based boards.
2896 CONFIG_BOOTCOUNT_RAM
2897 enable support for the bootcounter in RAM
2898 CONFIG_BOOTCOUNT_I2C
2899 enable support for the bootcounter on an i2c (like RTC) device.
2900 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2901 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2903 CONFIG_BOOTCOUNT_ALEN = address len
2905 - Show boot progress:
2906 CONFIG_SHOW_BOOT_PROGRESS
2908 Defining this option allows to add some board-
2909 specific code (calling a user-provided function
2910 "show_boot_progress(int)") that enables you to show
2911 the system's boot progress on some display (for
2912 example, some LED's) on your board. At the moment,
2913 the following checkpoints are implemented:
2915 - Detailed boot stage timing
2917 Define this option to get detailed timing of each stage
2918 of the boot process.
2920 CONFIG_BOOTSTAGE_USER_COUNT
2921 This is the number of available user bootstage records.
2922 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2923 a new ID will be allocated from this stash. If you exceed
2924 the limit, recording will stop.
2926 CONFIG_BOOTSTAGE_REPORT
2927 Define this to print a report before boot, similar to this:
2929 Timer summary in microseconds:
2932 3,575,678 3,575,678 board_init_f start
2933 3,575,695 17 arch_cpu_init A9
2934 3,575,777 82 arch_cpu_init done
2935 3,659,598 83,821 board_init_r start
2936 3,910,375 250,777 main_loop
2937 29,916,167 26,005,792 bootm_start
2938 30,361,327 445,160 start_kernel
2940 CONFIG_CMD_BOOTSTAGE
2941 Add a 'bootstage' command which supports printing a report
2942 and un/stashing of bootstage data.
2944 CONFIG_BOOTSTAGE_FDT
2945 Stash the bootstage information in the FDT. A root 'bootstage'
2946 node is created with each bootstage id as a child. Each child
2947 has a 'name' property and either 'mark' containing the
2948 mark time in microsecond, or 'accum' containing the
2949 accumulated time for that bootstage id in microseconds.
2954 name = "board_init_f";
2963 Code in the Linux kernel can find this in /proc/devicetree.
2965 Legacy uImage format:
2968 1 common/cmd_bootm.c before attempting to boot an image
2969 -1 common/cmd_bootm.c Image header has bad magic number
2970 2 common/cmd_bootm.c Image header has correct magic number
2971 -2 common/cmd_bootm.c Image header has bad checksum
2972 3 common/cmd_bootm.c Image header has correct checksum
2973 -3 common/cmd_bootm.c Image data has bad checksum
2974 4 common/cmd_bootm.c Image data has correct checksum
2975 -4 common/cmd_bootm.c Image is for unsupported architecture
2976 5 common/cmd_bootm.c Architecture check OK
2977 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2978 6 common/cmd_bootm.c Image Type check OK
2979 -6 common/cmd_bootm.c gunzip uncompression error
2980 -7 common/cmd_bootm.c Unimplemented compression type
2981 7 common/cmd_bootm.c Uncompression OK
2982 8 common/cmd_bootm.c No uncompress/copy overwrite error
2983 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2985 9 common/image.c Start initial ramdisk verification
2986 -10 common/image.c Ramdisk header has bad magic number
2987 -11 common/image.c Ramdisk header has bad checksum
2988 10 common/image.c Ramdisk header is OK
2989 -12 common/image.c Ramdisk data has bad checksum
2990 11 common/image.c Ramdisk data has correct checksum
2991 12 common/image.c Ramdisk verification complete, start loading
2992 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2993 13 common/image.c Start multifile image verification
2994 14 common/image.c No initial ramdisk, no multifile, continue.
2996 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2998 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2999 -31 post/post.c POST test failed, detected by post_output_backlog()
3000 -32 post/post.c POST test failed, detected by post_run_single()
3002 34 common/cmd_doc.c before loading a Image from a DOC device
3003 -35 common/cmd_doc.c Bad usage of "doc" command
3004 35 common/cmd_doc.c correct usage of "doc" command
3005 -36 common/cmd_doc.c No boot device
3006 36 common/cmd_doc.c correct boot device
3007 -37 common/cmd_doc.c Unknown Chip ID on boot device
3008 37 common/cmd_doc.c correct chip ID found, device available
3009 -38 common/cmd_doc.c Read Error on boot device
3010 38 common/cmd_doc.c reading Image header from DOC device OK
3011 -39 common/cmd_doc.c Image header has bad magic number
3012 39 common/cmd_doc.c Image header has correct magic number
3013 -40 common/cmd_doc.c Error reading Image from DOC device
3014 40 common/cmd_doc.c Image header has correct magic number
3015 41 common/cmd_ide.c before loading a Image from a IDE device
3016 -42 common/cmd_ide.c Bad usage of "ide" command
3017 42 common/cmd_ide.c correct usage of "ide" command
3018 -43 common/cmd_ide.c No boot device
3019 43 common/cmd_ide.c boot device found
3020 -44 common/cmd_ide.c Device not available
3021 44 common/cmd_ide.c Device available
3022 -45 common/cmd_ide.c wrong partition selected
3023 45 common/cmd_ide.c partition selected
3024 -46 common/cmd_ide.c Unknown partition table
3025 46 common/cmd_ide.c valid partition table found
3026 -47 common/cmd_ide.c Invalid partition type
3027 47 common/cmd_ide.c correct partition type
3028 -48 common/cmd_ide.c Error reading Image Header on boot device
3029 48 common/cmd_ide.c reading Image Header from IDE device OK
3030 -49 common/cmd_ide.c Image header has bad magic number
3031 49 common/cmd_ide.c Image header has correct magic number
3032 -50 common/cmd_ide.c Image header has bad checksum
3033 50 common/cmd_ide.c Image header has correct checksum
3034 -51 common/cmd_ide.c Error reading Image from IDE device
3035 51 common/cmd_ide.c reading Image from IDE device OK
3036 52 common/cmd_nand.c before loading a Image from a NAND device
3037 -53 common/cmd_nand.c Bad usage of "nand" command
3038 53 common/cmd_nand.c correct usage of "nand" command
3039 -54 common/cmd_nand.c No boot device
3040 54 common/cmd_nand.c boot device found
3041 -55 common/cmd_nand.c Unknown Chip ID on boot device
3042 55 common/cmd_nand.c correct chip ID found, device available
3043 -56 common/cmd_nand.c Error reading Image Header on boot device
3044 56 common/cmd_nand.c reading Image Header from NAND device OK
3045 -57 common/cmd_nand.c Image header has bad magic number
3046 57 common/cmd_nand.c Image header has correct magic number
3047 -58 common/cmd_nand.c Error reading Image from NAND device
3048 58 common/cmd_nand.c reading Image from NAND device OK
3050 -60 common/env_common.c Environment has a bad CRC, using default
3052 64 net/eth.c starting with Ethernet configuration.
3053 -64 net/eth.c no Ethernet found.
3054 65 net/eth.c Ethernet found.
3056 -80 common/cmd_net.c usage wrong
3057 80 common/cmd_net.c before calling NetLoop()
3058 -81 common/cmd_net.c some error in NetLoop() occurred
3059 81 common/cmd_net.c NetLoop() back without error
3060 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3061 82 common/cmd_net.c trying automatic boot
3062 83 common/cmd_net.c running "source" command
3063 -83 common/cmd_net.c some error in automatic boot or "source" command
3064 84 common/cmd_net.c end without errors
3069 100 common/cmd_bootm.c Kernel FIT Image has correct format
3070 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3071 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3072 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3073 102 common/cmd_bootm.c Kernel unit name specified
3074 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3075 103 common/cmd_bootm.c Found configuration node
3076 104 common/cmd_bootm.c Got kernel subimage node offset
3077 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3078 105 common/cmd_bootm.c Kernel subimage hash verification OK
3079 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3080 106 common/cmd_bootm.c Architecture check OK
3081 -106 common/cmd_bootm.c Kernel subimage has wrong type
3082 107 common/cmd_bootm.c Kernel subimage type OK
3083 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3084 108 common/cmd_bootm.c Got kernel subimage data/size
3085 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3086 -109 common/cmd_bootm.c Can't get kernel subimage type
3087 -110 common/cmd_bootm.c Can't get kernel subimage comp
3088 -111 common/cmd_bootm.c Can't get kernel subimage os
3089 -112 common/cmd_bootm.c Can't get kernel subimage load address
3090 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3092 120 common/image.c Start initial ramdisk verification
3093 -120 common/image.c Ramdisk FIT image has incorrect format
3094 121 common/image.c Ramdisk FIT image has correct format
3095 122 common/image.c No ramdisk subimage unit name, using configuration
3096 -122 common/image.c Can't get configuration for ramdisk subimage
3097 123 common/image.c Ramdisk unit name specified
3098 -124 common/image.c Can't get ramdisk subimage node offset
3099 125 common/image.c Got ramdisk subimage node offset
3100 -125 common/image.c Ramdisk subimage hash verification failed
3101 126 common/image.c Ramdisk subimage hash verification OK
3102 -126 common/image.c Ramdisk subimage for unsupported architecture
3103 127 common/image.c Architecture check OK
3104 -127 common/image.c Can't get ramdisk subimage data/size
3105 128 common/image.c Got ramdisk subimage data/size
3106 129 common/image.c Can't get ramdisk load address
3107 -129 common/image.c Got ramdisk load address
3109 -130 common/cmd_doc.c Incorrect FIT image format
3110 131 common/cmd_doc.c FIT image format OK
3112 -140 common/cmd_ide.c Incorrect FIT image format
3113 141 common/cmd_ide.c FIT image format OK
3115 -150 common/cmd_nand.c Incorrect FIT image format
3116 151 common/cmd_nand.c FIT image format OK
3118 - FIT image support:
3120 Enable support for the FIT uImage format.
3122 CONFIG_FIT_BEST_MATCH
3123 When no configuration is explicitly selected, default to the
3124 one whose fdt's compatibility field best matches that of
3125 U-Boot itself. A match is considered "best" if it matches the
3126 most specific compatibility entry of U-Boot's fdt's root node.
3127 The order of entries in the configuration's fdt is ignored.
3129 CONFIG_FIT_SIGNATURE
3130 This option enables signature verification of FIT uImages,
3131 using a hash signed and verified using RSA. See
3132 doc/uImage.FIT/signature.txt for more details.
3134 - Standalone program support:
3135 CONFIG_STANDALONE_LOAD_ADDR
3137 This option defines a board specific value for the
3138 address where standalone program gets loaded, thus
3139 overwriting the architecture dependent default
3142 - Frame Buffer Address:
3145 Define CONFIG_FB_ADDR if you want to use specific
3146 address for frame buffer. This is typically the case
3147 when using a graphics controller has separate video
3148 memory. U-Boot will then place the frame buffer at
3149 the given address instead of dynamically reserving it
3150 in system RAM by calling lcd_setmem(), which grabs
3151 the memory for the frame buffer depending on the
3152 configured panel size.
3154 Please see board_init_f function.
3156 - Automatic software updates via TFTP server
3158 CONFIG_UPDATE_TFTP_CNT_MAX
3159 CONFIG_UPDATE_TFTP_MSEC_MAX
3161 These options enable and control the auto-update feature;
3162 for a more detailed description refer to doc/README.update.
3164 - MTD Support (mtdparts command, UBI support)
3167 Adds the MTD device infrastructure from the Linux kernel.
3168 Needed for mtdparts command support.
3170 CONFIG_MTD_PARTITIONS
3172 Adds the MTD partitioning infrastructure from the Linux
3173 kernel. Needed for UBI support.
3178 Adds commands for interacting with MTD partitions formatted
3179 with the UBI flash translation layer
3181 Requires also defining CONFIG_RBTREE
3183 CONFIG_UBI_SILENCE_MSG
3185 Make the verbose messages from UBI stop printing. This leaves
3186 warnings and errors enabled.
3191 Adds commands for interacting with UBI volumes formatted as
3192 UBIFS. UBIFS is read-only in u-boot.
3194 Requires UBI support as well as CONFIG_LZO
3196 CONFIG_UBIFS_SILENCE_MSG
3198 Make the verbose messages from UBIFS stop printing. This leaves
3199 warnings and errors enabled.
3203 Enable building of SPL globally.
3206 LDSCRIPT for linking the SPL binary.
3208 CONFIG_SPL_MAX_FOOTPRINT
3209 Maximum size in memory allocated to the SPL, BSS included.
3210 When defined, the linker checks that the actual memory
3211 used by SPL from _start to __bss_end does not exceed it.
3212 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3213 must not be both defined at the same time.
3216 Maximum size of the SPL image (text, data, rodata, and
3217 linker lists sections), BSS excluded.
3218 When defined, the linker checks that the actual size does
3221 CONFIG_SPL_TEXT_BASE
3222 TEXT_BASE for linking the SPL binary.
3224 CONFIG_SPL_RELOC_TEXT_BASE
3225 Address to relocate to. If unspecified, this is equal to
3226 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3228 CONFIG_SPL_BSS_START_ADDR
3229 Link address for the BSS within the SPL binary.
3231 CONFIG_SPL_BSS_MAX_SIZE
3232 Maximum size in memory allocated to the SPL BSS.
3233 When defined, the linker checks that the actual memory used
3234 by SPL from __bss_start to __bss_end does not exceed it.
3235 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3236 must not be both defined at the same time.
3239 Adress of the start of the stack SPL will use
3241 CONFIG_SPL_RELOC_STACK
3242 Adress of the start of the stack SPL will use after
3243 relocation. If unspecified, this is equal to
3246 CONFIG_SYS_SPL_MALLOC_START
3247 Starting address of the malloc pool used in SPL.
3249 CONFIG_SYS_SPL_MALLOC_SIZE
3250 The size of the malloc pool used in SPL.
3252 CONFIG_SPL_FRAMEWORK
3253 Enable the SPL framework under common/. This framework
3254 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3255 NAND loading of the Linux Kernel.
3257 CONFIG_SPL_DISPLAY_PRINT
3258 For ARM, enable an optional function to print more information
3259 about the running system.
3261 CONFIG_SPL_INIT_MINIMAL
3262 Arch init code should be built for a very small image
3264 CONFIG_SPL_LIBCOMMON_SUPPORT
3265 Support for common/libcommon.o in SPL binary
3267 CONFIG_SPL_LIBDISK_SUPPORT
3268 Support for disk/libdisk.o in SPL binary
3270 CONFIG_SPL_I2C_SUPPORT
3271 Support for drivers/i2c/libi2c.o in SPL binary
3273 CONFIG_SPL_GPIO_SUPPORT
3274 Support for drivers/gpio/libgpio.o in SPL binary
3276 CONFIG_SPL_MMC_SUPPORT
3277 Support for drivers/mmc/libmmc.o in SPL binary
3279 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3280 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3281 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3282 Address, size and partition on the MMC to load U-Boot from
3283 when the MMC is being used in raw mode.
3285 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3286 Sector to load kernel uImage from when MMC is being
3287 used in raw mode (for Falcon mode)
3289 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3290 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3291 Sector and number of sectors to load kernel argument
3292 parameters from when MMC is being used in raw mode
3295 CONFIG_SPL_FAT_SUPPORT
3296 Support for fs/fat/libfat.o in SPL binary
3298 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3299 Filename to read to load U-Boot when reading from FAT
3301 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3302 Filename to read to load kernel uImage when reading
3303 from FAT (for Falcon mode)
3305 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3306 Filename to read to load kernel argument parameters
3307 when reading from FAT (for Falcon mode)
3309 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3310 Set this for NAND SPL on PPC mpc83xx targets, so that
3311 start.S waits for the rest of the SPL to load before
3312 continuing (the hardware starts execution after just
3313 loading the first page rather than the full 4K).
3315 CONFIG_SPL_NAND_BASE
3316 Include nand_base.c in the SPL. Requires
3317 CONFIG_SPL_NAND_DRIVERS.
3319 CONFIG_SPL_NAND_DRIVERS
3320 SPL uses normal NAND drivers, not minimal drivers.
3323 Include standard software ECC in the SPL
3325 CONFIG_SPL_NAND_SIMPLE
3326 Support for NAND boot using simple NAND drivers that
3327 expose the cmd_ctrl() interface.
3329 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3330 Set for the SPL on PPC mpc8xxx targets, support for
3331 drivers/ddr/fsl/libddr.o in SPL binary.
3333 CONFIG_SPL_COMMON_INIT_DDR
3334 Set for common ddr init with serial presence detect in
3337 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3338 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3339 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3340 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3341 CONFIG_SYS_NAND_ECCBYTES
3342 Defines the size and behavior of the NAND that SPL uses
3345 CONFIG_SPL_NAND_BOOT
3346 Add support NAND boot
3348 CONFIG_SYS_NAND_U_BOOT_OFFS
3349 Location in NAND to read U-Boot from
3351 CONFIG_SYS_NAND_U_BOOT_DST
3352 Location in memory to load U-Boot to
3354 CONFIG_SYS_NAND_U_BOOT_SIZE
3355 Size of image to load
3357 CONFIG_SYS_NAND_U_BOOT_START
3358 Entry point in loaded image to jump to
3360 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3361 Define this if you need to first read the OOB and then the
3362 data. This is used for example on davinci plattforms.
3364 CONFIG_SPL_OMAP3_ID_NAND
3365 Support for an OMAP3-specific set of functions to return the
3366 ID and MFR of the first attached NAND chip, if present.
3368 CONFIG_SPL_SERIAL_SUPPORT
3369 Support for drivers/serial/libserial.o in SPL binary
3371 CONFIG_SPL_SPI_FLASH_SUPPORT
3372 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3374 CONFIG_SPL_SPI_SUPPORT
3375 Support for drivers/spi/libspi.o in SPL binary
3377 CONFIG_SPL_RAM_DEVICE
3378 Support for running image already present in ram, in SPL binary
3380 CONFIG_SPL_LIBGENERIC_SUPPORT
3381 Support for lib/libgeneric.o in SPL binary
3383 CONFIG_SPL_ENV_SUPPORT
3384 Support for the environment operating in SPL binary
3386 CONFIG_SPL_NET_SUPPORT
3387 Support for the net/libnet.o in SPL binary.
3388 It conflicts with SPL env from storage medium specified by
3389 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3392 Image offset to which the SPL should be padded before appending
3393 the SPL payload. By default, this is defined as
3394 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3395 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3396 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3399 Final target image containing SPL and payload. Some SPLs
3400 use an arch-specific makefile fragment instead, for
3401 example if more than one image needs to be produced.
3403 CONFIG_FIT_SPL_PRINT
3404 Printing information about a FIT image adds quite a bit of
3405 code to SPL. So this is normally disabled in SPL. Use this
3406 option to re-enable it. This will affect the output of the
3407 bootm command when booting a FIT image.
3411 Enable building of TPL globally.
3414 Image offset to which the TPL should be padded before appending
3415 the TPL payload. By default, this is defined as
3416 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3417 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3418 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3423 [so far only for SMDK2400 boards]
3425 - Modem support enable:
3426 CONFIG_MODEM_SUPPORT
3428 - RTS/CTS Flow control enable:
3431 - Modem debug support:
3432 CONFIG_MODEM_SUPPORT_DEBUG
3434 Enables debugging stuff (char screen[1024], dbg())
3435 for modem support. Useful only with BDI2000.
3437 - Interrupt support (PPC):
3439 There are common interrupt_init() and timer_interrupt()
3440 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3441 for CPU specific initialization. interrupt_init_cpu()
3442 should set decrementer_count to appropriate value. If
3443 CPU resets decrementer automatically after interrupt
3444 (ppc4xx) it should set decrementer_count to zero.
3445 timer_interrupt() calls timer_interrupt_cpu() for CPU
3446 specific handling. If board has watchdog / status_led
3447 / other_activity_monitor it works automatically from
3448 general timer_interrupt().
3452 In the target system modem support is enabled when a
3453 specific key (key combination) is pressed during
3454 power-on. Otherwise U-Boot will boot normally
3455 (autoboot). The key_pressed() function is called from
3456 board_init(). Currently key_pressed() is a dummy
3457 function, returning 1 and thus enabling modem
3460 If there are no modem init strings in the
3461 environment, U-Boot proceed to autoboot; the
3462 previous output (banner, info printfs) will be
3465 See also: doc/README.Modem
3467 Board initialization settings:
3468 ------------------------------
3470 During Initialization u-boot calls a number of board specific functions
3471 to allow the preparation of board specific prerequisites, e.g. pin setup
3472 before drivers are initialized. To enable these callbacks the
3473 following configuration macros have to be defined. Currently this is
3474 architecture specific, so please check arch/your_architecture/lib/board.c
3475 typically in board_init_f() and board_init_r().
3477 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3478 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3479 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3480 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3482 Configuration Settings:
3483 -----------------------
3485 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3486 Optionally it can be defined to support 64-bit memory commands.
3488 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3489 undefine this when you're short of memory.
3491 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3492 width of the commands listed in the 'help' command output.
3494 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3495 prompt for user input.
3497 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3499 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3501 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3503 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3504 the application (usually a Linux kernel) when it is
3507 - CONFIG_SYS_BAUDRATE_TABLE:
3508 List of legal baudrate settings for this board.
3510 - CONFIG_SYS_CONSOLE_INFO_QUIET
3511 Suppress display of console information at boot.
3513 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3514 If the board specific function
3515 extern int overwrite_console (void);
3516 returns 1, the stdin, stderr and stdout are switched to the
3517 serial port, else the settings in the environment are used.
3519 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3520 Enable the call to overwrite_console().
3522 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3523 Enable overwrite of previous console environment settings.
3525 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3526 Begin and End addresses of the area used by the
3529 - CONFIG_SYS_ALT_MEMTEST:
3530 Enable an alternate, more extensive memory test.
3532 - CONFIG_SYS_MEMTEST_SCRATCH:
3533 Scratch address used by the alternate memory test
3534 You only need to set this if address zero isn't writeable
3536 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3537 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3538 this specified memory area will get subtracted from the top
3539 (end) of RAM and won't get "touched" at all by U-Boot. By
3540 fixing up gd->ram_size the Linux kernel should gets passed
3541 the now "corrected" memory size and won't touch it either.
3542 This should work for arch/ppc and arch/powerpc. Only Linux
3543 board ports in arch/powerpc with bootwrapper support that
3544 recalculate the memory size from the SDRAM controller setup
3545 will have to get fixed in Linux additionally.
3547 This option can be used as a workaround for the 440EPx/GRx
3548 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3551 WARNING: Please make sure that this value is a multiple of
3552 the Linux page size (normally 4k). If this is not the case,
3553 then the end address of the Linux memory will be located at a
3554 non page size aligned address and this could cause major
3557 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3558 Enable temporary baudrate change while serial download
3560 - CONFIG_SYS_SDRAM_BASE:
3561 Physical start address of SDRAM. _Must_ be 0 here.
3563 - CONFIG_SYS_MBIO_BASE:
3564 Physical start address of Motherboard I/O (if using a
3567 - CONFIG_SYS_FLASH_BASE:
3568 Physical start address of Flash memory.
3570 - CONFIG_SYS_MONITOR_BASE:
3571 Physical start address of boot monitor code (set by
3572 make config files to be same as the text base address
3573 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3574 CONFIG_SYS_FLASH_BASE when booting from flash.
3576 - CONFIG_SYS_MONITOR_LEN:
3577 Size of memory reserved for monitor code, used to
3578 determine _at_compile_time_ (!) if the environment is
3579 embedded within the U-Boot image, or in a separate
3582 - CONFIG_SYS_MALLOC_LEN:
3583 Size of DRAM reserved for malloc() use.
3585 - CONFIG_SYS_BOOTM_LEN:
3586 Normally compressed uImages are limited to an
3587 uncompressed size of 8 MBytes. If this is not enough,
3588 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3589 to adjust this setting to your needs.
3591 - CONFIG_SYS_BOOTMAPSZ:
3592 Maximum size of memory mapped by the startup code of
3593 the Linux kernel; all data that must be processed by
3594 the Linux kernel (bd_info, boot arguments, FDT blob if
3595 used) must be put below this limit, unless "bootm_low"
3596 environment variable is defined and non-zero. In such case
3597 all data for the Linux kernel must be between "bootm_low"
3598 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3599 variable "bootm_mapsize" will override the value of
3600 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3601 then the value in "bootm_size" will be used instead.
3603 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3604 Enable initrd_high functionality. If defined then the
3605 initrd_high feature is enabled and the bootm ramdisk subcommand
3608 - CONFIG_SYS_BOOT_GET_CMDLINE:
3609 Enables allocating and saving kernel cmdline in space between
3610 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3612 - CONFIG_SYS_BOOT_GET_KBD:
3613 Enables allocating and saving a kernel copy of the bd_info in
3614 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3616 - CONFIG_SYS_MAX_FLASH_BANKS:
3617 Max number of Flash memory banks
3619 - CONFIG_SYS_MAX_FLASH_SECT:
3620 Max number of sectors on a Flash chip
3622 - CONFIG_SYS_FLASH_ERASE_TOUT:
3623 Timeout for Flash erase operations (in ms)
3625 - CONFIG_SYS_FLASH_WRITE_TOUT:
3626 Timeout for Flash write operations (in ms)
3628 - CONFIG_SYS_FLASH_LOCK_TOUT
3629 Timeout for Flash set sector lock bit operation (in ms)
3631 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3632 Timeout for Flash clear lock bits operation (in ms)
3634 - CONFIG_SYS_FLASH_PROTECTION
3635 If defined, hardware flash sectors protection is used
3636 instead of U-Boot software protection.
3638 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3640 Enable TFTP transfers directly to flash memory;
3641 without this option such a download has to be
3642 performed in two steps: (1) download to RAM, and (2)
3643 copy from RAM to flash.
3645 The two-step approach is usually more reliable, since
3646 you can check if the download worked before you erase
3647 the flash, but in some situations (when system RAM is
3648 too limited to allow for a temporary copy of the
3649 downloaded image) this option may be very useful.
3651 - CONFIG_SYS_FLASH_CFI:
3652 Define if the flash driver uses extra elements in the
3653 common flash structure for storing flash geometry.
3655 - CONFIG_FLASH_CFI_DRIVER
3656 This option also enables the building of the cfi_flash driver
3657 in the drivers directory
3659 - CONFIG_FLASH_CFI_MTD
3660 This option enables the building of the cfi_mtd driver
3661 in the drivers directory. The driver exports CFI flash
3664 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3665 Use buffered writes to flash.
3667 - CONFIG_FLASH_SPANSION_S29WS_N
3668 s29ws-n MirrorBit flash has non-standard addresses for buffered
3671 - CONFIG_SYS_FLASH_QUIET_TEST
3672 If this option is defined, the common CFI flash doesn't
3673 print it's warning upon not recognized FLASH banks. This
3674 is useful, if some of the configured banks are only
3675 optionally available.
3677 - CONFIG_FLASH_SHOW_PROGRESS
3678 If defined (must be an integer), print out countdown
3679 digits and dots. Recommended value: 45 (9..1) for 80
3680 column displays, 15 (3..1) for 40 column displays.
3682 - CONFIG_FLASH_VERIFY
3683 If defined, the content of the flash (destination) is compared
3684 against the source after the write operation. An error message
3685 will be printed when the contents are not identical.
3686 Please note that this option is useless in nearly all cases,
3687 since such flash programming errors usually are detected earlier
3688 while unprotecting/erasing/programming. Please only enable
3689 this option if you really know what you are doing.
3691 - CONFIG_SYS_RX_ETH_BUFFER:
3692 Defines the number of Ethernet receive buffers. On some
3693 Ethernet controllers it is recommended to set this value
3694 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3695 buffers can be full shortly after enabling the interface
3696 on high Ethernet traffic.
3697 Defaults to 4 if not defined.
3699 - CONFIG_ENV_MAX_ENTRIES
3701 Maximum number of entries in the hash table that is used
3702 internally to store the environment settings. The default
3703 setting is supposed to be generous and should work in most
3704 cases. This setting can be used to tune behaviour; see
3705 lib/hashtable.c for details.
3707 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3708 - CONFIG_ENV_FLAGS_LIST_STATIC
3709 Enable validation of the values given to environment variables when
3710 calling env set. Variables can be restricted to only decimal,
3711 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3712 the variables can also be restricted to IP address or MAC address.
3714 The format of the list is:
3715 type_attribute = [s|d|x|b|i|m]
3716 access_atribute = [a|r|o|c]
3717 attributes = type_attribute[access_atribute]
3718 entry = variable_name[:attributes]
3721 The type attributes are:
3722 s - String (default)
3725 b - Boolean ([1yYtT|0nNfF])
3729 The access attributes are:
3735 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3736 Define this to a list (string) to define the ".flags"
3737 envirnoment variable in the default or embedded environment.
3739 - CONFIG_ENV_FLAGS_LIST_STATIC
3740 Define this to a list (string) to define validation that
3741 should be done if an entry is not found in the ".flags"
3742 environment variable. To override a setting in the static
3743 list, simply add an entry for the same variable name to the
3746 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3747 If defined, don't allow the -f switch to env set override variable
3750 - CONFIG_SYS_GENERIC_BOARD
3751 This selects the architecture-generic board system instead of the
3752 architecture-specific board files. It is intended to move boards
3753 to this new framework over time. Defining this will disable the
3754 arch/foo/lib/board.c file and use common/board_f.c and
3755 common/board_r.c instead. To use this option your architecture
3756 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3757 its config.mk file). If you find problems enabling this option on
3758 your board please report the problem and send patches!
3760 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3761 This is set by OMAP boards for the max time that reset should
3762 be asserted. See doc/README.omap-reset-time for details on how
3763 the value can be calulated on a given board.
3765 The following definitions that deal with the placement and management
3766 of environment data (variable area); in general, we support the
3767 following configurations:
3769 - CONFIG_BUILD_ENVCRC:
3771 Builds up envcrc with the target environment so that external utils
3772 may easily extract it and embed it in final U-Boot images.
3774 - CONFIG_ENV_IS_IN_FLASH:
3776 Define this if the environment is in flash memory.
3778 a) The environment occupies one whole flash sector, which is
3779 "embedded" in the text segment with the U-Boot code. This
3780 happens usually with "bottom boot sector" or "top boot
3781 sector" type flash chips, which have several smaller
3782 sectors at the start or the end. For instance, such a
3783 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3784 such a case you would place the environment in one of the
3785 4 kB sectors - with U-Boot code before and after it. With
3786 "top boot sector" type flash chips, you would put the
3787 environment in one of the last sectors, leaving a gap
3788 between U-Boot and the environment.
3790 - CONFIG_ENV_OFFSET:
3792 Offset of environment data (variable area) to the
3793 beginning of flash memory; for instance, with bottom boot
3794 type flash chips the second sector can be used: the offset
3795 for this sector is given here.
3797 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3801 This is just another way to specify the start address of
3802 the flash sector containing the environment (instead of
3805 - CONFIG_ENV_SECT_SIZE:
3807 Size of the sector containing the environment.
3810 b) Sometimes flash chips have few, equal sized, BIG sectors.
3811 In such a case you don't want to spend a whole sector for
3816 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3817 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3818 of this flash sector for the environment. This saves
3819 memory for the RAM copy of the environment.
3821 It may also save flash memory if you decide to use this
3822 when your environment is "embedded" within U-Boot code,
3823 since then the remainder of the flash sector could be used
3824 for U-Boot code. It should be pointed out that this is
3825 STRONGLY DISCOURAGED from a robustness point of view:
3826 updating the environment in flash makes it always
3827 necessary to erase the WHOLE sector. If something goes
3828 wrong before the contents has been restored from a copy in
3829 RAM, your target system will be dead.
3831 - CONFIG_ENV_ADDR_REDUND
3832 CONFIG_ENV_SIZE_REDUND
3834 These settings describe a second storage area used to hold
3835 a redundant copy of the environment data, so that there is
3836 a valid backup copy in case there is a power failure during
3837 a "saveenv" operation.
3839 BE CAREFUL! Any changes to the flash layout, and some changes to the
3840 source code will make it necessary to adapt <board>/u-boot.lds*
3844 - CONFIG_ENV_IS_IN_NVRAM:
3846 Define this if you have some non-volatile memory device
3847 (NVRAM, battery buffered SRAM) which you want to use for the
3853 These two #defines are used to determine the memory area you
3854 want to use for environment. It is assumed that this memory
3855 can just be read and written to, without any special
3858 BE CAREFUL! The first access to the environment happens quite early
3859 in U-Boot initalization (when we try to get the setting of for the
3860 console baudrate). You *MUST* have mapped your NVRAM area then, or
3863 Please note that even with NVRAM we still use a copy of the
3864 environment in RAM: we could work on NVRAM directly, but we want to
3865 keep settings there always unmodified except somebody uses "saveenv"
3866 to save the current settings.
3869 - CONFIG_ENV_IS_IN_EEPROM:
3871 Use this if you have an EEPROM or similar serial access
3872 device and a driver for it.
3874 - CONFIG_ENV_OFFSET:
3877 These two #defines specify the offset and size of the
3878 environment area within the total memory of your EEPROM.
3880 - CONFIG_SYS_I2C_EEPROM_ADDR:
3881 If defined, specified the chip address of the EEPROM device.
3882 The default address is zero.
3884 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3885 If defined, the number of bits used to address bytes in a
3886 single page in the EEPROM device. A 64 byte page, for example
3887 would require six bits.
3889 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3890 If defined, the number of milliseconds to delay between
3891 page writes. The default is zero milliseconds.
3893 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3894 The length in bytes of the EEPROM memory array address. Note
3895 that this is NOT the chip address length!
3897 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3898 EEPROM chips that implement "address overflow" are ones
3899 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3900 address and the extra bits end up in the "chip address" bit
3901 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3904 Note that we consider the length of the address field to
3905 still be one byte because the extra address bits are hidden
3906 in the chip address.
3908 - CONFIG_SYS_EEPROM_SIZE:
3909 The size in bytes of the EEPROM device.
3911 - CONFIG_ENV_EEPROM_IS_ON_I2C
3912 define this, if you have I2C and SPI activated, and your
3913 EEPROM, which holds the environment, is on the I2C bus.
3915 - CONFIG_I2C_ENV_EEPROM_BUS
3916 if you have an Environment on an EEPROM reached over
3917 I2C muxes, you can define here, how to reach this
3918 EEPROM. For example:
3920 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3922 EEPROM which holds the environment, is reached over
3923 a pca9547 i2c mux with address 0x70, channel 3.
3925 - CONFIG_ENV_IS_IN_DATAFLASH:
3927 Define this if you have a DataFlash memory device which you
3928 want to use for the environment.
3930 - CONFIG_ENV_OFFSET:
3934 These three #defines specify the offset and size of the
3935 environment area within the total memory of your DataFlash placed
3936 at the specified address.
3938 - CONFIG_ENV_IS_IN_REMOTE:
3940 Define this if you have a remote memory space which you
3941 want to use for the local device's environment.
3946 These two #defines specify the address and size of the
3947 environment area within the remote memory space. The
3948 local device can get the environment from remote memory
3949 space by SRIO or PCIE links.
3951 BE CAREFUL! For some special cases, the local device can not use
3952 "saveenv" command. For example, the local device will get the
3953 environment stored in a remote NOR flash by SRIO or PCIE link,
3954 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3956 - CONFIG_ENV_IS_IN_NAND:
3958 Define this if you have a NAND device which you want to use
3959 for the environment.
3961 - CONFIG_ENV_OFFSET:
3964 These two #defines specify the offset and size of the environment
3965 area within the first NAND device. CONFIG_ENV_OFFSET must be
3966 aligned to an erase block boundary.
3968 - CONFIG_ENV_OFFSET_REDUND (optional):
3970 This setting describes a second storage area of CONFIG_ENV_SIZE
3971 size used to hold a redundant copy of the environment data, so
3972 that there is a valid backup copy in case there is a power failure
3973 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3974 aligned to an erase block boundary.
3976 - CONFIG_ENV_RANGE (optional):
3978 Specifies the length of the region in which the environment
3979 can be written. This should be a multiple of the NAND device's
3980 block size. Specifying a range with more erase blocks than
3981 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3982 the range to be avoided.
3984 - CONFIG_ENV_OFFSET_OOB (optional):
3986 Enables support for dynamically retrieving the offset of the
3987 environment from block zero's out-of-band data. The
3988 "nand env.oob" command can be used to record this offset.
3989 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3990 using CONFIG_ENV_OFFSET_OOB.
3992 - CONFIG_NAND_ENV_DST
3994 Defines address in RAM to which the nand_spl code should copy the
3995 environment. If redundant environment is used, it will be copied to
3996 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3998 - CONFIG_ENV_IS_IN_UBI:
4000 Define this if you have an UBI volume that you want to use for the
4001 environment. This has the benefit of wear-leveling the environment
4002 accesses, which is important on NAND.
4004 - CONFIG_ENV_UBI_PART:
4006 Define this to a string that is the mtd partition containing the UBI.
4008 - CONFIG_ENV_UBI_VOLUME:
4010 Define this to the name of the volume that you want to store the
4013 - CONFIG_ENV_UBI_VOLUME_REDUND:
4015 Define this to the name of another volume to store a second copy of
4016 the environment in. This will enable redundant environments in UBI.
4017 It is assumed that both volumes are in the same MTD partition.
4019 - CONFIG_UBI_SILENCE_MSG
4020 - CONFIG_UBIFS_SILENCE_MSG
4022 You will probably want to define these to avoid a really noisy system
4023 when storing the env in UBI.
4025 - CONFIG_ENV_IS_IN_MMC:
4027 Define this if you have an MMC device which you want to use for the
4030 - CONFIG_SYS_MMC_ENV_DEV:
4032 Specifies which MMC device the environment is stored in.
4034 - CONFIG_SYS_MMC_ENV_PART (optional):
4036 Specifies which MMC partition the environment is stored in. If not
4037 set, defaults to partition 0, the user area. Common values might be
4038 1 (first MMC boot partition), 2 (second MMC boot partition).
4040 - CONFIG_ENV_OFFSET:
4043 These two #defines specify the offset and size of the environment
4044 area within the specified MMC device.
4046 If offset is positive (the usual case), it is treated as relative to
4047 the start of the MMC partition. If offset is negative, it is treated
4048 as relative to the end of the MMC partition. This can be useful if
4049 your board may be fitted with different MMC devices, which have
4050 different sizes for the MMC partitions, and you always want the
4051 environment placed at the very end of the partition, to leave the
4052 maximum possible space before it, to store other data.
4054 These two values are in units of bytes, but must be aligned to an
4055 MMC sector boundary.
4057 - CONFIG_ENV_OFFSET_REDUND (optional):
4059 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4060 hold a redundant copy of the environment data. This provides a
4061 valid backup copy in case the other copy is corrupted, e.g. due
4062 to a power failure during a "saveenv" operation.
4064 This value may also be positive or negative; this is handled in the
4065 same way as CONFIG_ENV_OFFSET.
4067 This value is also in units of bytes, but must also be aligned to
4068 an MMC sector boundary.
4070 - CONFIG_ENV_SIZE_REDUND (optional):
4072 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4073 set. If this value is set, it must be set to the same value as
4076 - CONFIG_SYS_SPI_INIT_OFFSET
4078 Defines offset to the initial SPI buffer area in DPRAM. The
4079 area is used at an early stage (ROM part) if the environment
4080 is configured to reside in the SPI EEPROM: We need a 520 byte
4081 scratch DPRAM area. It is used between the two initialization
4082 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4083 to be a good choice since it makes it far enough from the
4084 start of the data area as well as from the stack pointer.
4086 Please note that the environment is read-only until the monitor
4087 has been relocated to RAM and a RAM copy of the environment has been
4088 created; also, when using EEPROM you will have to use getenv_f()
4089 until then to read environment variables.
4091 The environment is protected by a CRC32 checksum. Before the monitor
4092 is relocated into RAM, as a result of a bad CRC you will be working
4093 with the compiled-in default environment - *silently*!!! [This is
4094 necessary, because the first environment variable we need is the
4095 "baudrate" setting for the console - if we have a bad CRC, we don't
4096 have any device yet where we could complain.]
4098 Note: once the monitor has been relocated, then it will complain if
4099 the default environment is used; a new CRC is computed as soon as you
4100 use the "saveenv" command to store a valid environment.
4102 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4103 Echo the inverted Ethernet link state to the fault LED.
4105 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4106 also needs to be defined.
4108 - CONFIG_SYS_FAULT_MII_ADDR:
4109 MII address of the PHY to check for the Ethernet link state.
4111 - CONFIG_NS16550_MIN_FUNCTIONS:
4112 Define this if you desire to only have use of the NS16550_init
4113 and NS16550_putc functions for the serial driver located at
4114 drivers/serial/ns16550.c. This option is useful for saving
4115 space for already greatly restricted images, including but not
4116 limited to NAND_SPL configurations.
4118 - CONFIG_DISPLAY_BOARDINFO
4119 Display information about the board that U-Boot is running on
4120 when U-Boot starts up. The board function checkboard() is called
4123 - CONFIG_DISPLAY_BOARDINFO_LATE
4124 Similar to the previous option, but display this information
4125 later, once stdio is running and output goes to the LCD, if
4128 Low Level (hardware related) configuration options:
4129 ---------------------------------------------------
4131 - CONFIG_SYS_CACHELINE_SIZE:
4132 Cache Line Size of the CPU.
4134 - CONFIG_SYS_DEFAULT_IMMR:
4135 Default address of the IMMR after system reset.
4137 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4138 and RPXsuper) to be able to adjust the position of
4139 the IMMR register after a reset.
4141 - CONFIG_SYS_CCSRBAR_DEFAULT:
4142 Default (power-on reset) physical address of CCSR on Freescale
4145 - CONFIG_SYS_CCSRBAR:
4146 Virtual address of CCSR. On a 32-bit build, this is typically
4147 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4149 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4150 for cross-platform code that uses that macro instead.
4152 - CONFIG_SYS_CCSRBAR_PHYS:
4153 Physical address of CCSR. CCSR can be relocated to a new
4154 physical address, if desired. In this case, this macro should
4155 be set to that address. Otherwise, it should be set to the
4156 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4157 is typically relocated on 36-bit builds. It is recommended
4158 that this macro be defined via the _HIGH and _LOW macros:
4160 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4161 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4163 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4164 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4165 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4166 used in assembly code, so it must not contain typecasts or
4167 integer size suffixes (e.g. "ULL").
4169 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4170 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4171 used in assembly code, so it must not contain typecasts or
4172 integer size suffixes (e.g. "ULL").
4174 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4175 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4176 forced to a value that ensures that CCSR is not relocated.
4178 - Floppy Disk Support:
4179 CONFIG_SYS_FDC_DRIVE_NUMBER
4181 the default drive number (default value 0)
4183 CONFIG_SYS_ISA_IO_STRIDE
4185 defines the spacing between FDC chipset registers
4188 CONFIG_SYS_ISA_IO_OFFSET
4190 defines the offset of register from address. It
4191 depends on which part of the data bus is connected to
4192 the FDC chipset. (default value 0)
4194 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4195 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4198 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4199 fdc_hw_init() is called at the beginning of the FDC
4200 setup. fdc_hw_init() must be provided by the board
4201 source code. It is used to make hardware dependant
4205 Most IDE controllers were designed to be connected with PCI
4206 interface. Only few of them were designed for AHB interface.
4207 When software is doing ATA command and data transfer to
4208 IDE devices through IDE-AHB controller, some additional
4209 registers accessing to these kind of IDE-AHB controller
4212 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4213 DO NOT CHANGE unless you know exactly what you're
4214 doing! (11-4) [MPC8xx/82xx systems only]
4216 - CONFIG_SYS_INIT_RAM_ADDR:
4218 Start address of memory area that can be used for
4219 initial data and stack; please note that this must be
4220 writable memory that is working WITHOUT special
4221 initialization, i. e. you CANNOT use normal RAM which
4222 will become available only after programming the
4223 memory controller and running certain initialization
4226 U-Boot uses the following memory types:
4227 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4228 - MPC824X: data cache
4229 - PPC4xx: data cache
4231 - CONFIG_SYS_GBL_DATA_OFFSET:
4233 Offset of the initial data structure in the memory
4234 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4235 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4236 data is located at the end of the available space
4237 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4238 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4239 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4240 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4243 On the MPC824X (or other systems that use the data
4244 cache for initial memory) the address chosen for
4245 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4246 point to an otherwise UNUSED address space between
4247 the top of RAM and the start of the PCI space.
4249 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4251 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4253 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4255 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4257 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4259 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4261 - CONFIG_SYS_OR_TIMING_SDRAM:
4264 - CONFIG_SYS_MAMR_PTA:
4265 periodic timer for refresh
4267 - CONFIG_SYS_DER: Debug Event Register (37-47)
4269 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4270 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4271 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4272 CONFIG_SYS_BR1_PRELIM:
4273 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4275 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4276 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4277 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4278 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4280 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4281 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4282 Machine Mode Register and Memory Periodic Timer
4283 Prescaler definitions (SDRAM timing)
4285 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4286 enable I2C microcode relocation patch (MPC8xx);
4287 define relocation offset in DPRAM [DSP2]
4289 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4290 enable SMC microcode relocation patch (MPC8xx);
4291 define relocation offset in DPRAM [SMC1]
4293 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4294 enable SPI microcode relocation patch (MPC8xx);
4295 define relocation offset in DPRAM [SCC4]
4297 - CONFIG_SYS_USE_OSCCLK:
4298 Use OSCM clock mode on MBX8xx board. Be careful,
4299 wrong setting might damage your board. Read
4300 doc/README.MBX before setting this variable!
4302 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4303 Offset of the bootmode word in DPRAM used by post
4304 (Power On Self Tests). This definition overrides
4305 #define'd default value in commproc.h resp.
4308 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4309 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4310 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4311 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4312 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4313 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4314 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4315 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4316 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4318 - CONFIG_PCI_DISABLE_PCIE:
4319 Disable PCI-Express on systems where it is supported but not
4322 - CONFIG_PCI_ENUM_ONLY
4323 Only scan through and get the devices on the busses.
4324 Don't do any setup work, presumably because someone or
4325 something has already done it, and we don't need to do it
4326 a second time. Useful for platforms that are pre-booted
4327 by coreboot or similar.
4329 - CONFIG_PCI_INDIRECT_BRIDGE:
4330 Enable support for indirect PCI bridges.
4333 Chip has SRIO or not
4336 Board has SRIO 1 port available
4339 Board has SRIO 2 port available
4341 - CONFIG_SRIO_PCIE_BOOT_MASTER
4342 Board can support master function for Boot from SRIO and PCIE
4344 - CONFIG_SYS_SRIOn_MEM_VIRT:
4345 Virtual Address of SRIO port 'n' memory region
4347 - CONFIG_SYS_SRIOn_MEM_PHYS:
4348 Physical Address of SRIO port 'n' memory region
4350 - CONFIG_SYS_SRIOn_MEM_SIZE:
4351 Size of SRIO port 'n' memory region
4353 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4354 Defined to tell the NAND controller that the NAND chip is using
4356 Not all NAND drivers use this symbol.
4357 Example of drivers that use it:
4358 - drivers/mtd/nand/ndfc.c
4359 - drivers/mtd/nand/mxc_nand.c
4361 - CONFIG_SYS_NDFC_EBC0_CFG
4362 Sets the EBC0_CFG register for the NDFC. If not defined
4363 a default value will be used.
4366 Get DDR timing information from an I2C EEPROM. Common
4367 with pluggable memory modules such as SODIMMs
4370 I2C address of the SPD EEPROM
4372 - CONFIG_SYS_SPD_BUS_NUM
4373 If SPD EEPROM is on an I2C bus other than the first
4374 one, specify here. Note that the value must resolve
4375 to something your driver can deal with.
4377 - CONFIG_SYS_DDR_RAW_TIMING
4378 Get DDR timing information from other than SPD. Common with
4379 soldered DDR chips onboard without SPD. DDR raw timing
4380 parameters are extracted from datasheet and hard-coded into
4381 header files or board specific files.
4383 - CONFIG_FSL_DDR_INTERACTIVE
4384 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4386 - CONFIG_SYS_83XX_DDR_USES_CS0
4387 Only for 83xx systems. If specified, then DDR should
4388 be configured using CS0 and CS1 instead of CS2 and CS3.
4390 - CONFIG_ETHER_ON_FEC[12]
4391 Define to enable FEC[12] on a 8xx series processor.
4393 - CONFIG_FEC[12]_PHY
4394 Define to the hardcoded PHY address which corresponds
4395 to the given FEC; i. e.
4396 #define CONFIG_FEC1_PHY 4
4397 means that the PHY with address 4 is connected to FEC1
4399 When set to -1, means to probe for first available.
4401 - CONFIG_FEC[12]_PHY_NORXERR
4402 The PHY does not have a RXERR line (RMII only).
4403 (so program the FEC to ignore it).
4406 Enable RMII mode for all FECs.
4407 Note that this is a global option, we can't
4408 have one FEC in standard MII mode and another in RMII mode.
4410 - CONFIG_CRC32_VERIFY
4411 Add a verify option to the crc32 command.
4414 => crc32 -v <address> <count> <crc32>
4416 Where address/count indicate a memory area
4417 and crc32 is the correct crc32 which the
4421 Add the "loopw" memory command. This only takes effect if
4422 the memory commands are activated globally (CONFIG_CMD_MEM).
4425 Add the "mdc" and "mwc" memory commands. These are cyclic
4430 This command will print 4 bytes (10,11,12,13) each 500 ms.
4432 => mwc.l 100 12345678 10
4433 This command will write 12345678 to address 100 all 10 ms.
4435 This only takes effect if the memory commands are activated
4436 globally (CONFIG_CMD_MEM).
4438 - CONFIG_SKIP_LOWLEVEL_INIT
4439 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4440 low level initializations (like setting up the memory
4441 controller) are omitted and/or U-Boot does not
4442 relocate itself into RAM.
4444 Normally this variable MUST NOT be defined. The only
4445 exception is when U-Boot is loaded (to RAM) by some
4446 other boot loader or by a debugger which performs
4447 these initializations itself.
4450 Modifies the behaviour of start.S when compiling a loader
4451 that is executed before the actual U-Boot. E.g. when
4452 compiling a NAND SPL.
4455 Modifies the behaviour of start.S when compiling a loader
4456 that is executed after the SPL and before the actual U-Boot.
4457 It is loaded by the SPL.
4459 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4460 Only for 85xx systems. If this variable is specified, the section
4461 .resetvec is not kept and the section .bootpg is placed in the
4462 previous 4k of the .text section.
4464 - CONFIG_ARCH_MAP_SYSMEM
4465 Generally U-Boot (and in particular the md command) uses
4466 effective address. It is therefore not necessary to regard
4467 U-Boot address as virtual addresses that need to be translated
4468 to physical addresses. However, sandbox requires this, since
4469 it maintains its own little RAM buffer which contains all
4470 addressable memory. This option causes some memory accesses
4471 to be mapped through map_sysmem() / unmap_sysmem().
4473 - CONFIG_USE_ARCH_MEMCPY
4474 CONFIG_USE_ARCH_MEMSET
4475 If these options are used a optimized version of memcpy/memset will
4476 be used if available. These functions may be faster under some
4477 conditions but may increase the binary size.
4479 - CONFIG_X86_RESET_VECTOR
4480 If defined, the x86 reset vector code is included. This is not
4481 needed when U-Boot is running from Coreboot.
4484 Defines the MPU clock speed (in MHz).
4486 NOTE : currently only supported on AM335x platforms.
4488 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4489 Enables the RTC32K OSC on AM33xx based plattforms
4491 Freescale QE/FMAN Firmware Support:
4492 -----------------------------------
4494 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4495 loading of "firmware", which is encoded in the QE firmware binary format.
4496 This firmware often needs to be loaded during U-Boot booting, so macros
4497 are used to identify the storage device (NOR flash, SPI, etc) and the address
4500 - CONFIG_SYS_QE_FMAN_FW_ADDR
4501 The address in the storage device where the firmware is located. The
4502 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4505 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4506 The maximum possible size of the firmware. The firmware binary format
4507 has a field that specifies the actual size of the firmware, but it
4508 might not be possible to read any part of the firmware unless some
4509 local storage is allocated to hold the entire firmware first.
4511 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4512 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4513 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4514 virtual address in NOR flash.
4516 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4517 Specifies that QE/FMAN firmware is located in NAND flash.
4518 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4520 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4521 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4522 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4524 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4525 Specifies that QE/FMAN firmware is located on the primary SPI
4526 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4528 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4529 Specifies that QE/FMAN firmware is located in the remote (master)
4530 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4531 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4532 window->master inbound window->master LAW->the ucode address in
4533 master's memory space.
4535 Building the Software:
4536 ======================
4538 Building U-Boot has been tested in several native build environments
4539 and in many different cross environments. Of course we cannot support
4540 all possibly existing versions of cross development tools in all
4541 (potentially obsolete) versions. In case of tool chain problems we
4542 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4543 which is extensively used to build and test U-Boot.
4545 If you are not using a native environment, it is assumed that you
4546 have GNU cross compiling tools available in your path. In this case,
4547 you must set the environment variable CROSS_COMPILE in your shell.
4548 Note that no changes to the Makefile or any other source files are
4549 necessary. For example using the ELDK on a 4xx CPU, please enter:
4551 $ CROSS_COMPILE=ppc_4xx-
4552 $ export CROSS_COMPILE
4554 Note: If you wish to generate Windows versions of the utilities in
4555 the tools directory you can use the MinGW toolchain
4556 (http://www.mingw.org). Set your HOST tools to the MinGW
4557 toolchain and execute 'make tools'. For example:
4559 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4561 Binaries such as tools/mkimage.exe will be created which can
4562 be executed on computers running Windows.
4564 U-Boot is intended to be simple to build. After installing the
4565 sources you must configure U-Boot for one specific board type. This
4570 where "NAME_config" is the name of one of the existing configu-
4571 rations; see boards.cfg for supported names.
4573 Note: for some board special configuration names may exist; check if
4574 additional information is available from the board vendor; for
4575 instance, the TQM823L systems are available without (standard)
4576 or with LCD support. You can select such additional "features"
4577 when choosing the configuration, i. e.
4580 - will configure for a plain TQM823L, i. e. no LCD support
4582 make TQM823L_LCD_config
4583 - will configure for a TQM823L with U-Boot console on LCD
4588 Finally, type "make all", and you should get some working U-Boot
4589 images ready for download to / installation on your system:
4591 - "u-boot.bin" is a raw binary image
4592 - "u-boot" is an image in ELF binary format
4593 - "u-boot.srec" is in Motorola S-Record format
4595 By default the build is performed locally and the objects are saved
4596 in the source directory. One of the two methods can be used to change
4597 this behavior and build U-Boot to some external directory:
4599 1. Add O= to the make command line invocations:
4601 make O=/tmp/build distclean
4602 make O=/tmp/build NAME_config
4603 make O=/tmp/build all
4605 2. Set environment variable BUILD_DIR to point to the desired location:
4607 export BUILD_DIR=/tmp/build
4612 Note that the command line "O=" setting overrides the BUILD_DIR environment
4616 Please be aware that the Makefiles assume you are using GNU make, so
4617 for instance on NetBSD you might need to use "gmake" instead of
4621 If the system board that you have is not listed, then you will need
4622 to port U-Boot to your hardware platform. To do this, follow these
4625 1. Add a new configuration option for your board to the toplevel
4626 "boards.cfg" file, using the existing entries as examples.
4627 Follow the instructions there to keep the boards in order.
4628 2. Create a new directory to hold your board specific code. Add any
4629 files you need. In your board directory, you will need at least
4630 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4631 3. Create a new configuration file "include/configs/<board>.h" for
4633 3. If you're porting U-Boot to a new CPU, then also create a new
4634 directory to hold your CPU specific code. Add any files you need.
4635 4. Run "make <board>_config" with your new name.
4636 5. Type "make", and you should get a working "u-boot.srec" file
4637 to be installed on your target system.
4638 6. Debug and solve any problems that might arise.
4639 [Of course, this last step is much harder than it sounds.]
4642 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4643 ==============================================================
4645 If you have modified U-Boot sources (for instance added a new board
4646 or support for new devices, a new CPU, etc.) you are expected to
4647 provide feedback to the other developers. The feedback normally takes
4648 the form of a "patch", i. e. a context diff against a certain (latest
4649 official or latest in the git repository) version of U-Boot sources.
4651 But before you submit such a patch, please verify that your modifi-
4652 cation did not break existing code. At least make sure that *ALL* of
4653 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4654 just run the "MAKEALL" script, which will configure and build U-Boot
4655 for ALL supported system. Be warned, this will take a while. You can
4656 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4657 environment variable to the script, i. e. to use the ELDK cross tools
4660 CROSS_COMPILE=ppc_8xx- MAKEALL
4662 or to build on a native PowerPC system you can type
4664 CROSS_COMPILE=' ' MAKEALL
4666 When using the MAKEALL script, the default behaviour is to build
4667 U-Boot in the source directory. This location can be changed by
4668 setting the BUILD_DIR environment variable. Also, for each target
4669 built, the MAKEALL script saves two log files (<target>.ERR and
4670 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4671 location can be changed by setting the MAKEALL_LOGDIR environment
4672 variable. For example:
4674 export BUILD_DIR=/tmp/build
4675 export MAKEALL_LOGDIR=/tmp/log
4676 CROSS_COMPILE=ppc_8xx- MAKEALL
4678 With the above settings build objects are saved in the /tmp/build,
4679 log files are saved in the /tmp/log and the source tree remains clean
4680 during the whole build process.
4683 See also "U-Boot Porting Guide" below.
4686 Monitor Commands - Overview:
4687 ============================
4689 go - start application at address 'addr'
4690 run - run commands in an environment variable
4691 bootm - boot application image from memory
4692 bootp - boot image via network using BootP/TFTP protocol
4693 bootz - boot zImage from memory
4694 tftpboot- boot image via network using TFTP protocol
4695 and env variables "ipaddr" and "serverip"
4696 (and eventually "gatewayip")
4697 tftpput - upload a file via network using TFTP protocol
4698 rarpboot- boot image via network using RARP/TFTP protocol
4699 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4700 loads - load S-Record file over serial line
4701 loadb - load binary file over serial line (kermit mode)
4703 mm - memory modify (auto-incrementing)
4704 nm - memory modify (constant address)
4705 mw - memory write (fill)
4707 cmp - memory compare
4708 crc32 - checksum calculation
4709 i2c - I2C sub-system
4710 sspi - SPI utility commands
4711 base - print or set address offset
4712 printenv- print environment variables
4713 setenv - set environment variables
4714 saveenv - save environment variables to persistent storage
4715 protect - enable or disable FLASH write protection
4716 erase - erase FLASH memory
4717 flinfo - print FLASH memory information
4718 nand - NAND memory operations (see doc/README.nand)
4719 bdinfo - print Board Info structure
4720 iminfo - print header information for application image
4721 coninfo - print console devices and informations
4722 ide - IDE sub-system
4723 loop - infinite loop on address range
4724 loopw - infinite write loop on address range
4725 mtest - simple RAM test
4726 icache - enable or disable instruction cache
4727 dcache - enable or disable data cache
4728 reset - Perform RESET of the CPU
4729 echo - echo args to console
4730 version - print monitor version
4731 help - print online help
4732 ? - alias for 'help'
4735 Monitor Commands - Detailed Description:
4736 ========================================
4740 For now: just type "help <command>".
4743 Environment Variables:
4744 ======================
4746 U-Boot supports user configuration using Environment Variables which
4747 can be made persistent by saving to Flash memory.
4749 Environment Variables are set using "setenv", printed using
4750 "printenv", and saved to Flash using "saveenv". Using "setenv"
4751 without a value can be used to delete a variable from the
4752 environment. As long as you don't save the environment you are
4753 working with an in-memory copy. In case the Flash area containing the
4754 environment is erased by accident, a default environment is provided.
4756 Some configuration options can be set using Environment Variables.
4758 List of environment variables (most likely not complete):
4760 baudrate - see CONFIG_BAUDRATE
4762 bootdelay - see CONFIG_BOOTDELAY
4764 bootcmd - see CONFIG_BOOTCOMMAND
4766 bootargs - Boot arguments when booting an RTOS image
4768 bootfile - Name of the image to load with TFTP
4770 bootm_low - Memory range available for image processing in the bootm
4771 command can be restricted. This variable is given as
4772 a hexadecimal number and defines lowest address allowed
4773 for use by the bootm command. See also "bootm_size"
4774 environment variable. Address defined by "bootm_low" is
4775 also the base of the initial memory mapping for the Linux
4776 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4779 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4780 This variable is given as a hexadecimal number and it
4781 defines the size of the memory region starting at base
4782 address bootm_low that is accessible by the Linux kernel
4783 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4784 as the default value if it is defined, and bootm_size is
4787 bootm_size - Memory range available for image processing in the bootm
4788 command can be restricted. This variable is given as
4789 a hexadecimal number and defines the size of the region
4790 allowed for use by the bootm command. See also "bootm_low"
4791 environment variable.
4793 updatefile - Location of the software update file on a TFTP server, used
4794 by the automatic software update feature. Please refer to
4795 documentation in doc/README.update for more details.
4797 autoload - if set to "no" (any string beginning with 'n'),
4798 "bootp" will just load perform a lookup of the
4799 configuration from the BOOTP server, but not try to
4800 load any image using TFTP
4802 autostart - if set to "yes", an image loaded using the "bootp",
4803 "rarpboot", "tftpboot" or "diskboot" commands will
4804 be automatically started (by internally calling
4807 If set to "no", a standalone image passed to the
4808 "bootm" command will be copied to the load address
4809 (and eventually uncompressed), but NOT be started.
4810 This can be used to load and uncompress arbitrary
4813 fdt_high - if set this restricts the maximum address that the
4814 flattened device tree will be copied into upon boot.
4815 For example, if you have a system with 1 GB memory
4816 at physical address 0x10000000, while Linux kernel
4817 only recognizes the first 704 MB as low memory, you
4818 may need to set fdt_high as 0x3C000000 to have the
4819 device tree blob be copied to the maximum address
4820 of the 704 MB low memory, so that Linux kernel can
4821 access it during the boot procedure.
4823 If this is set to the special value 0xFFFFFFFF then
4824 the fdt will not be copied at all on boot. For this
4825 to work it must reside in writable memory, have
4826 sufficient padding on the end of it for u-boot to
4827 add the information it needs into it, and the memory
4828 must be accessible by the kernel.
4830 fdtcontroladdr- if set this is the address of the control flattened
4831 device tree used by U-Boot when CONFIG_OF_CONTROL is
4834 i2cfast - (PPC405GP|PPC405EP only)
4835 if set to 'y' configures Linux I2C driver for fast
4836 mode (400kHZ). This environment variable is used in
4837 initialization code. So, for changes to be effective
4838 it must be saved and board must be reset.
4840 initrd_high - restrict positioning of initrd images:
4841 If this variable is not set, initrd images will be
4842 copied to the highest possible address in RAM; this
4843 is usually what you want since it allows for
4844 maximum initrd size. If for some reason you want to
4845 make sure that the initrd image is loaded below the
4846 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4847 variable to a value of "no" or "off" or "0".
4848 Alternatively, you can set it to a maximum upper
4849 address to use (U-Boot will still check that it
4850 does not overwrite the U-Boot stack and data).
4852 For instance, when you have a system with 16 MB
4853 RAM, and want to reserve 4 MB from use by Linux,
4854 you can do this by adding "mem=12M" to the value of
4855 the "bootargs" variable. However, now you must make
4856 sure that the initrd image is placed in the first
4857 12 MB as well - this can be done with
4859 setenv initrd_high 00c00000
4861 If you set initrd_high to 0xFFFFFFFF, this is an
4862 indication to U-Boot that all addresses are legal
4863 for the Linux kernel, including addresses in flash
4864 memory. In this case U-Boot will NOT COPY the
4865 ramdisk at all. This may be useful to reduce the
4866 boot time on your system, but requires that this
4867 feature is supported by your Linux kernel.
4869 ipaddr - IP address; needed for tftpboot command
4871 loadaddr - Default load address for commands like "bootp",
4872 "rarpboot", "tftpboot", "loadb" or "diskboot"
4874 loads_echo - see CONFIG_LOADS_ECHO
4876 serverip - TFTP server IP address; needed for tftpboot command
4878 bootretry - see CONFIG_BOOT_RETRY_TIME
4880 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4882 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4884 ethprime - controls which interface is used first.
4886 ethact - controls which interface is currently active.
4887 For example you can do the following
4889 => setenv ethact FEC
4890 => ping 192.168.0.1 # traffic sent on FEC
4891 => setenv ethact SCC
4892 => ping 10.0.0.1 # traffic sent on SCC
4894 ethrotate - When set to "no" U-Boot does not go through all
4895 available network interfaces.
4896 It just stays at the currently selected interface.
4898 netretry - When set to "no" each network operation will
4899 either succeed or fail without retrying.
4900 When set to "once" the network operation will
4901 fail when all the available network interfaces
4902 are tried once without success.
4903 Useful on scripts which control the retry operation
4906 npe_ucode - set load address for the NPE microcode
4908 silent_linux - If set then linux will be told to boot silently, by
4909 changing the console to be empty. If "yes" it will be
4910 made silent. If "no" it will not be made silent. If
4911 unset, then it will be made silent if the U-Boot console
4914 tftpsrcport - If this is set, the value is used for TFTP's
4917 tftpdstport - If this is set, the value is used for TFTP's UDP
4918 destination port instead of the Well Know Port 69.
4920 tftpblocksize - Block size to use for TFTP transfers; if not set,
4921 we use the TFTP server's default block size
4923 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4924 seconds, minimum value is 1000 = 1 second). Defines
4925 when a packet is considered to be lost so it has to
4926 be retransmitted. The default is 5000 = 5 seconds.
4927 Lowering this value may make downloads succeed
4928 faster in networks with high packet loss rates or
4929 with unreliable TFTP servers.
4931 vlan - When set to a value < 4095 the traffic over
4932 Ethernet is encapsulated/received over 802.1q
4935 The following image location variables contain the location of images
4936 used in booting. The "Image" column gives the role of the image and is
4937 not an environment variable name. The other columns are environment
4938 variable names. "File Name" gives the name of the file on a TFTP
4939 server, "RAM Address" gives the location in RAM the image will be
4940 loaded to, and "Flash Location" gives the image's address in NOR
4941 flash or offset in NAND flash.
4943 *Note* - these variables don't have to be defined for all boards, some
4944 boards currenlty use other variables for these purposes, and some
4945 boards use these variables for other purposes.
4947 Image File Name RAM Address Flash Location
4948 ----- --------- ----------- --------------
4949 u-boot u-boot u-boot_addr_r u-boot_addr
4950 Linux kernel bootfile kernel_addr_r kernel_addr
4951 device tree blob fdtfile fdt_addr_r fdt_addr
4952 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4954 The following environment variables may be used and automatically
4955 updated by the network boot commands ("bootp" and "rarpboot"),
4956 depending the information provided by your boot server:
4958 bootfile - see above
4959 dnsip - IP address of your Domain Name Server
4960 dnsip2 - IP address of your secondary Domain Name Server
4961 gatewayip - IP address of the Gateway (Router) to use
4962 hostname - Target hostname
4964 netmask - Subnet Mask
4965 rootpath - Pathname of the root filesystem on the NFS server
4966 serverip - see above
4969 There are two special Environment Variables:
4971 serial# - contains hardware identification information such
4972 as type string and/or serial number
4973 ethaddr - Ethernet address
4975 These variables can be set only once (usually during manufacturing of
4976 the board). U-Boot refuses to delete or overwrite these variables
4977 once they have been set once.
4980 Further special Environment Variables:
4982 ver - Contains the U-Boot version string as printed
4983 with the "version" command. This variable is
4984 readonly (see CONFIG_VERSION_VARIABLE).
4987 Please note that changes to some configuration parameters may take
4988 only effect after the next boot (yes, that's just like Windoze :-).
4991 Callback functions for environment variables:
4992 ---------------------------------------------
4994 For some environment variables, the behavior of u-boot needs to change
4995 when their values are changed. This functionailty allows functions to
4996 be associated with arbitrary variables. On creation, overwrite, or
4997 deletion, the callback will provide the opportunity for some side
4998 effect to happen or for the change to be rejected.
5000 The callbacks are named and associated with a function using the
5001 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5003 These callbacks are associated with variables in one of two ways. The
5004 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5005 in the board configuration to a string that defines a list of
5006 associations. The list must be in the following format:
5008 entry = variable_name[:callback_name]
5011 If the callback name is not specified, then the callback is deleted.
5012 Spaces are also allowed anywhere in the list.
5014 Callbacks can also be associated by defining the ".callbacks" variable
5015 with the same list format above. Any association in ".callbacks" will
5016 override any association in the static list. You can define
5017 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5018 ".callbacks" envirnoment variable in the default or embedded environment.
5021 Command Line Parsing:
5022 =====================
5024 There are two different command line parsers available with U-Boot:
5025 the old "simple" one, and the much more powerful "hush" shell:
5027 Old, simple command line parser:
5028 --------------------------------
5030 - supports environment variables (through setenv / saveenv commands)
5031 - several commands on one line, separated by ';'
5032 - variable substitution using "... ${name} ..." syntax
5033 - special characters ('$', ';') can be escaped by prefixing with '\',
5035 setenv bootcmd bootm \${address}
5036 - You can also escape text by enclosing in single apostrophes, for example:
5037 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5042 - similar to Bourne shell, with control structures like
5043 if...then...else...fi, for...do...done; while...do...done,
5044 until...do...done, ...
5045 - supports environment ("global") variables (through setenv / saveenv
5046 commands) and local shell variables (through standard shell syntax
5047 "name=value"); only environment variables can be used with "run"
5053 (1) If a command line (or an environment variable executed by a "run"
5054 command) contains several commands separated by semicolon, and
5055 one of these commands fails, then the remaining commands will be
5058 (2) If you execute several variables with one call to run (i. e.
5059 calling run with a list of variables as arguments), any failing
5060 command will cause "run" to terminate, i. e. the remaining
5061 variables are not executed.
5063 Note for Redundant Ethernet Interfaces:
5064 =======================================
5066 Some boards come with redundant Ethernet interfaces; U-Boot supports
5067 such configurations and is capable of automatic selection of a
5068 "working" interface when needed. MAC assignment works as follows:
5070 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5071 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5072 "eth1addr" (=>eth1), "eth2addr", ...
5074 If the network interface stores some valid MAC address (for instance
5075 in SROM), this is used as default address if there is NO correspon-
5076 ding setting in the environment; if the corresponding environment
5077 variable is set, this overrides the settings in the card; that means:
5079 o If the SROM has a valid MAC address, and there is no address in the
5080 environment, the SROM's address is used.
5082 o If there is no valid address in the SROM, and a definition in the
5083 environment exists, then the value from the environment variable is
5086 o If both the SROM and the environment contain a MAC address, and
5087 both addresses are the same, this MAC address is used.
5089 o If both the SROM and the environment contain a MAC address, and the
5090 addresses differ, the value from the environment is used and a
5093 o If neither SROM nor the environment contain a MAC address, an error
5096 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5097 will be programmed into hardware as part of the initialization process. This
5098 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5099 The naming convention is as follows:
5100 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5105 U-Boot is capable of booting (and performing other auxiliary operations on)
5106 images in two formats:
5108 New uImage format (FIT)
5109 -----------------------
5111 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5112 to Flattened Device Tree). It allows the use of images with multiple
5113 components (several kernels, ramdisks, etc.), with contents protected by
5114 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5120 Old image format is based on binary files which can be basically anything,
5121 preceded by a special header; see the definitions in include/image.h for
5122 details; basically, the header defines the following image properties:
5124 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5125 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5126 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5127 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5129 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5130 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5131 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5132 * Compression Type (uncompressed, gzip, bzip2)
5138 The header is marked by a special Magic Number, and both the header
5139 and the data portions of the image are secured against corruption by
5146 Although U-Boot should support any OS or standalone application
5147 easily, the main focus has always been on Linux during the design of
5150 U-Boot includes many features that so far have been part of some
5151 special "boot loader" code within the Linux kernel. Also, any
5152 "initrd" images to be used are no longer part of one big Linux image;
5153 instead, kernel and "initrd" are separate images. This implementation
5154 serves several purposes:
5156 - the same features can be used for other OS or standalone
5157 applications (for instance: using compressed images to reduce the
5158 Flash memory footprint)
5160 - it becomes much easier to port new Linux kernel versions because
5161 lots of low-level, hardware dependent stuff are done by U-Boot
5163 - the same Linux kernel image can now be used with different "initrd"
5164 images; of course this also means that different kernel images can
5165 be run with the same "initrd". This makes testing easier (you don't
5166 have to build a new "zImage.initrd" Linux image when you just
5167 change a file in your "initrd"). Also, a field-upgrade of the
5168 software is easier now.
5174 Porting Linux to U-Boot based systems:
5175 ---------------------------------------
5177 U-Boot cannot save you from doing all the necessary modifications to
5178 configure the Linux device drivers for use with your target hardware
5179 (no, we don't intend to provide a full virtual machine interface to
5182 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5184 Just make sure your machine specific header file (for instance
5185 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5186 Information structure as we define in include/asm-<arch>/u-boot.h,
5187 and make sure that your definition of IMAP_ADDR uses the same value
5188 as your U-Boot configuration in CONFIG_SYS_IMMR.
5191 Configuring the Linux kernel:
5192 -----------------------------
5194 No specific requirements for U-Boot. Make sure you have some root
5195 device (initial ramdisk, NFS) for your target system.
5198 Building a Linux Image:
5199 -----------------------
5201 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5202 not used. If you use recent kernel source, a new build target
5203 "uImage" will exist which automatically builds an image usable by
5204 U-Boot. Most older kernels also have support for a "pImage" target,
5205 which was introduced for our predecessor project PPCBoot and uses a
5206 100% compatible format.
5215 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5216 encapsulate a compressed Linux kernel image with header information,
5217 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5219 * build a standard "vmlinux" kernel image (in ELF binary format):
5221 * convert the kernel into a raw binary image:
5223 ${CROSS_COMPILE}-objcopy -O binary \
5224 -R .note -R .comment \
5225 -S vmlinux linux.bin
5227 * compress the binary image:
5231 * package compressed binary image for U-Boot:
5233 mkimage -A ppc -O linux -T kernel -C gzip \
5234 -a 0 -e 0 -n "Linux Kernel Image" \
5235 -d linux.bin.gz uImage
5238 The "mkimage" tool can also be used to create ramdisk images for use
5239 with U-Boot, either separated from the Linux kernel image, or
5240 combined into one file. "mkimage" encapsulates the images with a 64
5241 byte header containing information about target architecture,
5242 operating system, image type, compression method, entry points, time
5243 stamp, CRC32 checksums, etc.
5245 "mkimage" can be called in two ways: to verify existing images and
5246 print the header information, or to build new images.
5248 In the first form (with "-l" option) mkimage lists the information
5249 contained in the header of an existing U-Boot image; this includes
5250 checksum verification:
5252 tools/mkimage -l image
5253 -l ==> list image header information
5255 The second form (with "-d" option) is used to build a U-Boot image
5256 from a "data file" which is used as image payload:
5258 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5259 -n name -d data_file image
5260 -A ==> set architecture to 'arch'
5261 -O ==> set operating system to 'os'
5262 -T ==> set image type to 'type'
5263 -C ==> set compression type 'comp'
5264 -a ==> set load address to 'addr' (hex)
5265 -e ==> set entry point to 'ep' (hex)
5266 -n ==> set image name to 'name'
5267 -d ==> use image data from 'datafile'
5269 Right now, all Linux kernels for PowerPC systems use the same load
5270 address (0x00000000), but the entry point address depends on the
5273 - 2.2.x kernels have the entry point at 0x0000000C,
5274 - 2.3.x and later kernels have the entry point at 0x00000000.
5276 So a typical call to build a U-Boot image would read:
5278 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5279 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5280 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5281 > examples/uImage.TQM850L
5282 Image Name: 2.4.4 kernel for TQM850L
5283 Created: Wed Jul 19 02:34:59 2000
5284 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5285 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5286 Load Address: 0x00000000
5287 Entry Point: 0x00000000
5289 To verify the contents of the image (or check for corruption):
5291 -> tools/mkimage -l examples/uImage.TQM850L
5292 Image Name: 2.4.4 kernel for TQM850L
5293 Created: Wed Jul 19 02:34:59 2000
5294 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5295 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5296 Load Address: 0x00000000
5297 Entry Point: 0x00000000
5299 NOTE: for embedded systems where boot time is critical you can trade
5300 speed for memory and install an UNCOMPRESSED image instead: this
5301 needs more space in Flash, but boots much faster since it does not
5302 need to be uncompressed:
5304 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5305 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5306 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5307 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5308 > examples/uImage.TQM850L-uncompressed
5309 Image Name: 2.4.4 kernel for TQM850L
5310 Created: Wed Jul 19 02:34:59 2000
5311 Image Type: PowerPC Linux Kernel Image (uncompressed)
5312 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5313 Load Address: 0x00000000
5314 Entry Point: 0x00000000
5317 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5318 when your kernel is intended to use an initial ramdisk:
5320 -> tools/mkimage -n 'Simple Ramdisk Image' \
5321 > -A ppc -O linux -T ramdisk -C gzip \
5322 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5323 Image Name: Simple Ramdisk Image
5324 Created: Wed Jan 12 14:01:50 2000
5325 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5326 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5327 Load Address: 0x00000000
5328 Entry Point: 0x00000000
5330 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5331 option performs the converse operation of the mkimage's second form (the "-d"
5332 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5335 tools/dumpimage -i image -p position data_file
5336 -i ==> extract from the 'image' a specific 'data_file', \
5337 indexed by 'position'
5340 Installing a Linux Image:
5341 -------------------------
5343 To downloading a U-Boot image over the serial (console) interface,
5344 you must convert the image to S-Record format:
5346 objcopy -I binary -O srec examples/image examples/image.srec
5348 The 'objcopy' does not understand the information in the U-Boot
5349 image header, so the resulting S-Record file will be relative to
5350 address 0x00000000. To load it to a given address, you need to
5351 specify the target address as 'offset' parameter with the 'loads'
5354 Example: install the image to address 0x40100000 (which on the
5355 TQM8xxL is in the first Flash bank):
5357 => erase 40100000 401FFFFF
5363 ## Ready for S-Record download ...
5364 ~>examples/image.srec
5365 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5367 15989 15990 15991 15992
5368 [file transfer complete]
5370 ## Start Addr = 0x00000000
5373 You can check the success of the download using the 'iminfo' command;
5374 this includes a checksum verification so you can be sure no data
5375 corruption happened:
5379 ## Checking Image at 40100000 ...
5380 Image Name: 2.2.13 for initrd on TQM850L
5381 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5382 Data Size: 335725 Bytes = 327 kB = 0 MB
5383 Load Address: 00000000
5384 Entry Point: 0000000c
5385 Verifying Checksum ... OK
5391 The "bootm" command is used to boot an application that is stored in
5392 memory (RAM or Flash). In case of a Linux kernel image, the contents
5393 of the "bootargs" environment variable is passed to the kernel as
5394 parameters. You can check and modify this variable using the
5395 "printenv" and "setenv" commands:
5398 => printenv bootargs
5399 bootargs=root=/dev/ram
5401 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5403 => printenv bootargs
5404 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5407 ## Booting Linux kernel at 40020000 ...
5408 Image Name: 2.2.13 for NFS on TQM850L
5409 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5410 Data Size: 381681 Bytes = 372 kB = 0 MB
5411 Load Address: 00000000
5412 Entry Point: 0000000c
5413 Verifying Checksum ... OK
5414 Uncompressing Kernel Image ... OK
5415 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
5416 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5417 time_init: decrementer frequency = 187500000/60
5418 Calibrating delay loop... 49.77 BogoMIPS
5419 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5422 If you want to boot a Linux kernel with initial RAM disk, you pass
5423 the memory addresses of both the kernel and the initrd image (PPBCOOT
5424 format!) to the "bootm" command:
5426 => imi 40100000 40200000
5428 ## Checking Image at 40100000 ...
5429 Image Name: 2.2.13 for initrd on TQM850L
5430 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5431 Data Size: 335725 Bytes = 327 kB = 0 MB
5432 Load Address: 00000000
5433 Entry Point: 0000000c
5434 Verifying Checksum ... OK
5436 ## Checking Image at 40200000 ...
5437 Image Name: Simple Ramdisk Image
5438 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5439 Data Size: 566530 Bytes = 553 kB = 0 MB
5440 Load Address: 00000000
5441 Entry Point: 00000000
5442 Verifying Checksum ... OK
5444 => bootm 40100000 40200000
5445 ## Booting Linux kernel at 40100000 ...
5446 Image Name: 2.2.13 for initrd on TQM850L
5447 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5448 Data Size: 335725 Bytes = 327 kB = 0 MB
5449 Load Address: 00000000
5450 Entry Point: 0000000c
5451 Verifying Checksum ... OK
5452 Uncompressing Kernel Image ... OK
5453 ## Loading RAMDisk Image at 40200000 ...
5454 Image Name: Simple Ramdisk Image
5455 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5456 Data Size: 566530 Bytes = 553 kB = 0 MB
5457 Load Address: 00000000
5458 Entry Point: 00000000
5459 Verifying Checksum ... OK
5460 Loading Ramdisk ... OK
5461 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
5462 Boot arguments: root=/dev/ram
5463 time_init: decrementer frequency = 187500000/60
5464 Calibrating delay loop... 49.77 BogoMIPS
5466 RAMDISK: Compressed image found at block 0
5467 VFS: Mounted root (ext2 filesystem).
5471 Boot Linux and pass a flat device tree:
5474 First, U-Boot must be compiled with the appropriate defines. See the section
5475 titled "Linux Kernel Interface" above for a more in depth explanation. The
5476 following is an example of how to start a kernel and pass an updated
5482 oft=oftrees/mpc8540ads.dtb
5483 => tftp $oftaddr $oft
5484 Speed: 1000, full duplex
5486 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5487 Filename 'oftrees/mpc8540ads.dtb'.
5488 Load address: 0x300000
5491 Bytes transferred = 4106 (100a hex)
5492 => tftp $loadaddr $bootfile
5493 Speed: 1000, full duplex
5495 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5497 Load address: 0x200000
5498 Loading:############
5500 Bytes transferred = 1029407 (fb51f hex)
5505 => bootm $loadaddr - $oftaddr
5506 ## Booting image at 00200000 ...
5507 Image Name: Linux-2.6.17-dirty
5508 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5509 Data Size: 1029343 Bytes = 1005.2 kB
5510 Load Address: 00000000
5511 Entry Point: 00000000
5512 Verifying Checksum ... OK
5513 Uncompressing Kernel Image ... OK
5514 Booting using flat device tree at 0x300000
5515 Using MPC85xx ADS machine description
5516 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5520 More About U-Boot Image Types:
5521 ------------------------------
5523 U-Boot supports the following image types:
5525 "Standalone Programs" are directly runnable in the environment
5526 provided by U-Boot; it is expected that (if they behave
5527 well) you can continue to work in U-Boot after return from
5528 the Standalone Program.
5529 "OS Kernel Images" are usually images of some Embedded OS which
5530 will take over control completely. Usually these programs
5531 will install their own set of exception handlers, device
5532 drivers, set up the MMU, etc. - this means, that you cannot
5533 expect to re-enter U-Boot except by resetting the CPU.
5534 "RAMDisk Images" are more or less just data blocks, and their
5535 parameters (address, size) are passed to an OS kernel that is
5537 "Multi-File Images" contain several images, typically an OS
5538 (Linux) kernel image and one or more data images like
5539 RAMDisks. This construct is useful for instance when you want
5540 to boot over the network using BOOTP etc., where the boot
5541 server provides just a single image file, but you want to get
5542 for instance an OS kernel and a RAMDisk image.
5544 "Multi-File Images" start with a list of image sizes, each
5545 image size (in bytes) specified by an "uint32_t" in network
5546 byte order. This list is terminated by an "(uint32_t)0".
5547 Immediately after the terminating 0 follow the images, one by
5548 one, all aligned on "uint32_t" boundaries (size rounded up to
5549 a multiple of 4 bytes).
5551 "Firmware Images" are binary images containing firmware (like
5552 U-Boot or FPGA images) which usually will be programmed to
5555 "Script files" are command sequences that will be executed by
5556 U-Boot's command interpreter; this feature is especially
5557 useful when you configure U-Boot to use a real shell (hush)
5558 as command interpreter.
5560 Booting the Linux zImage:
5561 -------------------------
5563 On some platforms, it's possible to boot Linux zImage. This is done
5564 using the "bootz" command. The syntax of "bootz" command is the same
5565 as the syntax of "bootm" command.
5567 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5568 kernel with raw initrd images. The syntax is slightly different, the
5569 address of the initrd must be augmented by it's size, in the following
5570 format: "<initrd addres>:<initrd size>".
5576 One of the features of U-Boot is that you can dynamically load and
5577 run "standalone" applications, which can use some resources of
5578 U-Boot like console I/O functions or interrupt services.
5580 Two simple examples are included with the sources:
5585 'examples/hello_world.c' contains a small "Hello World" Demo
5586 application; it is automatically compiled when you build U-Boot.
5587 It's configured to run at address 0x00040004, so you can play with it
5591 ## Ready for S-Record download ...
5592 ~>examples/hello_world.srec
5593 1 2 3 4 5 6 7 8 9 10 11 ...
5594 [file transfer complete]
5596 ## Start Addr = 0x00040004
5598 => go 40004 Hello World! This is a test.
5599 ## Starting application at 0x00040004 ...
5610 Hit any key to exit ...
5612 ## Application terminated, rc = 0x0
5614 Another example, which demonstrates how to register a CPM interrupt
5615 handler with the U-Boot code, can be found in 'examples/timer.c'.
5616 Here, a CPM timer is set up to generate an interrupt every second.
5617 The interrupt service routine is trivial, just printing a '.'
5618 character, but this is just a demo program. The application can be
5619 controlled by the following keys:
5621 ? - print current values og the CPM Timer registers
5622 b - enable interrupts and start timer
5623 e - stop timer and disable interrupts
5624 q - quit application
5627 ## Ready for S-Record download ...
5628 ~>examples/timer.srec
5629 1 2 3 4 5 6 7 8 9 10 11 ...
5630 [file transfer complete]
5632 ## Start Addr = 0x00040004
5635 ## Starting application at 0x00040004 ...
5638 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5641 [q, b, e, ?] Set interval 1000000 us
5644 [q, b, e, ?] ........
5645 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5648 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5651 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5654 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5656 [q, b, e, ?] ...Stopping timer
5658 [q, b, e, ?] ## Application terminated, rc = 0x0
5664 Over time, many people have reported problems when trying to use the
5665 "minicom" terminal emulation program for serial download. I (wd)
5666 consider minicom to be broken, and recommend not to use it. Under
5667 Unix, I recommend to use C-Kermit for general purpose use (and
5668 especially for kermit binary protocol download ("loadb" command), and
5669 use "cu" for S-Record download ("loads" command). See
5670 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5671 for help with kermit.
5674 Nevertheless, if you absolutely want to use it try adding this
5675 configuration to your "File transfer protocols" section:
5677 Name Program Name U/D FullScr IO-Red. Multi
5678 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5679 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5685 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5686 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5688 Building requires a cross environment; it is known to work on
5689 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5690 need gmake since the Makefiles are not compatible with BSD make).
5691 Note that the cross-powerpc package does not install include files;
5692 attempting to build U-Boot will fail because <machine/ansi.h> is
5693 missing. This file has to be installed and patched manually:
5695 # cd /usr/pkg/cross/powerpc-netbsd/include
5697 # ln -s powerpc machine
5698 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5699 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5701 Native builds *don't* work due to incompatibilities between native
5702 and U-Boot include files.
5704 Booting assumes that (the first part of) the image booted is a
5705 stage-2 loader which in turn loads and then invokes the kernel
5706 proper. Loader sources will eventually appear in the NetBSD source
5707 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5708 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5711 Implementation Internals:
5712 =========================
5714 The following is not intended to be a complete description of every
5715 implementation detail. However, it should help to understand the
5716 inner workings of U-Boot and make it easier to port it to custom
5720 Initial Stack, Global Data:
5721 ---------------------------
5723 The implementation of U-Boot is complicated by the fact that U-Boot
5724 starts running out of ROM (flash memory), usually without access to
5725 system RAM (because the memory controller is not initialized yet).
5726 This means that we don't have writable Data or BSS segments, and BSS
5727 is not initialized as zero. To be able to get a C environment working
5728 at all, we have to allocate at least a minimal stack. Implementation
5729 options for this are defined and restricted by the CPU used: Some CPU
5730 models provide on-chip memory (like the IMMR area on MPC8xx and
5731 MPC826x processors), on others (parts of) the data cache can be
5732 locked as (mis-) used as memory, etc.
5734 Chris Hallinan posted a good summary of these issues to the
5735 U-Boot mailing list:
5737 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5738 From: "Chris Hallinan" <clh@net1plus.com>
5739 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5742 Correct me if I'm wrong, folks, but the way I understand it
5743 is this: Using DCACHE as initial RAM for Stack, etc, does not
5744 require any physical RAM backing up the cache. The cleverness
5745 is that the cache is being used as a temporary supply of
5746 necessary storage before the SDRAM controller is setup. It's
5747 beyond the scope of this list to explain the details, but you
5748 can see how this works by studying the cache architecture and
5749 operation in the architecture and processor-specific manuals.
5751 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5752 is another option for the system designer to use as an
5753 initial stack/RAM area prior to SDRAM being available. Either
5754 option should work for you. Using CS 4 should be fine if your
5755 board designers haven't used it for something that would
5756 cause you grief during the initial boot! It is frequently not
5759 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5760 with your processor/board/system design. The default value
5761 you will find in any recent u-boot distribution in
5762 walnut.h should work for you. I'd set it to a value larger
5763 than your SDRAM module. If you have a 64MB SDRAM module, set
5764 it above 400_0000. Just make sure your board has no resources
5765 that are supposed to respond to that address! That code in
5766 start.S has been around a while and should work as is when
5767 you get the config right.
5772 It is essential to remember this, since it has some impact on the C
5773 code for the initialization procedures:
5775 * Initialized global data (data segment) is read-only. Do not attempt
5778 * Do not use any uninitialized global data (or implicitely initialized
5779 as zero data - BSS segment) at all - this is undefined, initiali-
5780 zation is performed later (when relocating to RAM).
5782 * Stack space is very limited. Avoid big data buffers or things like
5785 Having only the stack as writable memory limits means we cannot use
5786 normal global data to share information beween the code. But it
5787 turned out that the implementation of U-Boot can be greatly
5788 simplified by making a global data structure (gd_t) available to all
5789 functions. We could pass a pointer to this data as argument to _all_
5790 functions, but this would bloat the code. Instead we use a feature of
5791 the GCC compiler (Global Register Variables) to share the data: we
5792 place a pointer (gd) to the global data into a register which we
5793 reserve for this purpose.
5795 When choosing a register for such a purpose we are restricted by the
5796 relevant (E)ABI specifications for the current architecture, and by
5797 GCC's implementation.
5799 For PowerPC, the following registers have specific use:
5801 R2: reserved for system use
5802 R3-R4: parameter passing and return values
5803 R5-R10: parameter passing
5804 R13: small data area pointer
5808 (U-Boot also uses R12 as internal GOT pointer. r12
5809 is a volatile register so r12 needs to be reset when
5810 going back and forth between asm and C)
5812 ==> U-Boot will use R2 to hold a pointer to the global data
5814 Note: on PPC, we could use a static initializer (since the
5815 address of the global data structure is known at compile time),
5816 but it turned out that reserving a register results in somewhat
5817 smaller code - although the code savings are not that big (on
5818 average for all boards 752 bytes for the whole U-Boot image,
5819 624 text + 127 data).
5821 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5822 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5824 ==> U-Boot will use P3 to hold a pointer to the global data
5826 On ARM, the following registers are used:
5828 R0: function argument word/integer result
5829 R1-R3: function argument word
5830 R9: platform specific
5831 R10: stack limit (used only if stack checking is enabled)
5832 R11: argument (frame) pointer
5833 R12: temporary workspace
5836 R15: program counter
5838 ==> U-Boot will use R9 to hold a pointer to the global data
5840 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5842 On Nios II, the ABI is documented here:
5843 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5845 ==> U-Boot will use gp to hold a pointer to the global data
5847 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5848 to access small data sections, so gp is free.
5850 On NDS32, the following registers are used:
5852 R0-R1: argument/return
5854 R15: temporary register for assembler
5855 R16: trampoline register
5856 R28: frame pointer (FP)
5857 R29: global pointer (GP)
5858 R30: link register (LP)
5859 R31: stack pointer (SP)
5860 PC: program counter (PC)
5862 ==> U-Boot will use R10 to hold a pointer to the global data
5864 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5865 or current versions of GCC may "optimize" the code too much.
5870 U-Boot runs in system state and uses physical addresses, i.e. the
5871 MMU is not used either for address mapping nor for memory protection.
5873 The available memory is mapped to fixed addresses using the memory
5874 controller. In this process, a contiguous block is formed for each
5875 memory type (Flash, SDRAM, SRAM), even when it consists of several
5876 physical memory banks.
5878 U-Boot is installed in the first 128 kB of the first Flash bank (on
5879 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5880 booting and sizing and initializing DRAM, the code relocates itself
5881 to the upper end of DRAM. Immediately below the U-Boot code some
5882 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5883 configuration setting]. Below that, a structure with global Board
5884 Info data is placed, followed by the stack (growing downward).
5886 Additionally, some exception handler code is copied to the low 8 kB
5887 of DRAM (0x00000000 ... 0x00001FFF).
5889 So a typical memory configuration with 16 MB of DRAM could look like
5892 0x0000 0000 Exception Vector code
5895 0x0000 2000 Free for Application Use
5901 0x00FB FF20 Monitor Stack (Growing downward)
5902 0x00FB FFAC Board Info Data and permanent copy of global data
5903 0x00FC 0000 Malloc Arena
5906 0x00FE 0000 RAM Copy of Monitor Code
5907 ... eventually: LCD or video framebuffer
5908 ... eventually: pRAM (Protected RAM - unchanged by reset)
5909 0x00FF FFFF [End of RAM]
5912 System Initialization:
5913 ----------------------
5915 In the reset configuration, U-Boot starts at the reset entry point
5916 (on most PowerPC systems at address 0x00000100). Because of the reset
5917 configuration for CS0# this is a mirror of the onboard Flash memory.
5918 To be able to re-map memory U-Boot then jumps to its link address.
5919 To be able to implement the initialization code in C, a (small!)
5920 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5921 which provide such a feature like MPC8xx or MPC8260), or in a locked
5922 part of the data cache. After that, U-Boot initializes the CPU core,
5923 the caches and the SIU.
5925 Next, all (potentially) available memory banks are mapped using a
5926 preliminary mapping. For example, we put them on 512 MB boundaries
5927 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5928 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5929 programmed for SDRAM access. Using the temporary configuration, a
5930 simple memory test is run that determines the size of the SDRAM
5933 When there is more than one SDRAM bank, and the banks are of
5934 different size, the largest is mapped first. For equal size, the first
5935 bank (CS2#) is mapped first. The first mapping is always for address
5936 0x00000000, with any additional banks following immediately to create
5937 contiguous memory starting from 0.
5939 Then, the monitor installs itself at the upper end of the SDRAM area
5940 and allocates memory for use by malloc() and for the global Board
5941 Info data; also, the exception vector code is copied to the low RAM
5942 pages, and the final stack is set up.
5944 Only after this relocation will you have a "normal" C environment;
5945 until that you are restricted in several ways, mostly because you are
5946 running from ROM, and because the code will have to be relocated to a
5950 U-Boot Porting Guide:
5951 ----------------------
5953 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5957 int main(int argc, char *argv[])
5959 sighandler_t no_more_time;
5961 signal(SIGALRM, no_more_time);
5962 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5964 if (available_money > available_manpower) {
5965 Pay consultant to port U-Boot;
5969 Download latest U-Boot source;
5971 Subscribe to u-boot mailing list;
5974 email("Hi, I am new to U-Boot, how do I get started?");
5977 Read the README file in the top level directory;
5978 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5979 Read applicable doc/*.README;
5980 Read the source, Luke;
5981 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5984 if (available_money > toLocalCurrency ($2500))
5987 Add a lot of aggravation and time;
5989 if (a similar board exists) { /* hopefully... */
5990 cp -a board/<similar> board/<myboard>
5991 cp include/configs/<similar>.h include/configs/<myboard>.h
5993 Create your own board support subdirectory;
5994 Create your own board include/configs/<myboard>.h file;
5996 Edit new board/<myboard> files
5997 Edit new include/configs/<myboard>.h
6002 Add / modify source code;
6006 email("Hi, I am having problems...");
6008 Send patch file to the U-Boot email list;
6009 if (reasonable critiques)
6010 Incorporate improvements from email list code review;
6012 Defend code as written;
6018 void no_more_time (int sig)
6027 All contributions to U-Boot should conform to the Linux kernel
6028 coding style; see the file "Documentation/CodingStyle" and the script
6029 "scripts/Lindent" in your Linux kernel source directory.
6031 Source files originating from a different project (for example the
6032 MTD subsystem) are generally exempt from these guidelines and are not
6033 reformated to ease subsequent migration to newer versions of those
6036 Please note that U-Boot is implemented in C (and to some small parts in
6037 Assembler); no C++ is used, so please do not use C++ style comments (//)
6040 Please also stick to the following formatting rules:
6041 - remove any trailing white space
6042 - use TAB characters for indentation and vertical alignment, not spaces
6043 - make sure NOT to use DOS '\r\n' line feeds
6044 - do not add more than 2 consecutive empty lines to source files
6045 - do not add trailing empty lines to source files
6047 Submissions which do not conform to the standards may be returned
6048 with a request to reformat the changes.
6054 Since the number of patches for U-Boot is growing, we need to
6055 establish some rules. Submissions which do not conform to these rules
6056 may be rejected, even when they contain important and valuable stuff.
6058 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6060 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6061 see http://lists.denx.de/mailman/listinfo/u-boot
6063 When you send a patch, please include the following information with
6066 * For bug fixes: a description of the bug and how your patch fixes
6067 this bug. Please try to include a way of demonstrating that the
6068 patch actually fixes something.
6070 * For new features: a description of the feature and your
6073 * A CHANGELOG entry as plaintext (separate from the patch)
6075 * For major contributions, your entry to the CREDITS file
6077 * When you add support for a new board, don't forget to add a
6078 maintainer e-mail address to the boards.cfg file, too.
6080 * If your patch adds new configuration options, don't forget to
6081 document these in the README file.
6083 * The patch itself. If you are using git (which is *strongly*
6084 recommended) you can easily generate the patch using the
6085 "git format-patch". If you then use "git send-email" to send it to
6086 the U-Boot mailing list, you will avoid most of the common problems
6087 with some other mail clients.
6089 If you cannot use git, use "diff -purN OLD NEW". If your version of
6090 diff does not support these options, then get the latest version of
6093 The current directory when running this command shall be the parent
6094 directory of the U-Boot source tree (i. e. please make sure that
6095 your patch includes sufficient directory information for the
6098 We prefer patches as plain text. MIME attachments are discouraged,
6099 and compressed attachments must not be used.
6101 * If one logical set of modifications affects or creates several
6102 files, all these changes shall be submitted in a SINGLE patch file.
6104 * Changesets that contain different, unrelated modifications shall be
6105 submitted as SEPARATE patches, one patch per changeset.
6110 * Before sending the patch, run the MAKEALL script on your patched
6111 source tree and make sure that no errors or warnings are reported
6112 for any of the boards.
6114 * Keep your modifications to the necessary minimum: A patch
6115 containing several unrelated changes or arbitrary reformats will be
6116 returned with a request to re-formatting / split it.
6118 * If you modify existing code, make sure that your new code does not
6119 add to the memory footprint of the code ;-) Small is beautiful!
6120 When adding new features, these should compile conditionally only
6121 (using #ifdef), and the resulting code with the new feature
6122 disabled must not need more memory than the old code without your
6125 * Remember that there is a size limit of 100 kB per message on the
6126 u-boot mailing list. Bigger patches will be moderated. If they are
6127 reasonable and not too big, they will be acknowledged. But patches
6128 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob