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 - Intel Monahans options:
501 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
503 Defines the Monahans run mode to oscillator
504 ratio. Valid values are 8, 16, 24, 31. The core
505 frequency is this value multiplied by 13 MHz.
507 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
509 Defines the Monahans turbo mode to oscillator
510 ratio. Valid values are 1 (default if undefined) and
511 2. The core frequency as calculated above is multiplied
515 CONFIG_SYS_INIT_SP_OFFSET
517 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
518 pointer. This is needed for the temporary stack before
521 CONFIG_SYS_MIPS_CACHE_MODE
523 Cache operation mode for the MIPS CPU.
524 See also arch/mips/include/asm/mipsregs.h.
526 CONF_CM_CACHABLE_NO_WA
529 CONF_CM_CACHABLE_NONCOHERENT
533 CONF_CM_CACHABLE_ACCELERATED
535 CONFIG_SYS_XWAY_EBU_BOOTCFG
537 Special option for Lantiq XWAY SoCs for booting from NOR flash.
538 See also arch/mips/cpu/mips32/start.S.
540 CONFIG_XWAY_SWAP_BYTES
542 Enable compilation of tools/xway-swap-bytes needed for Lantiq
543 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
544 be swapped if a flash programmer is used.
547 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
549 Select high exception vectors of the ARM core, e.g., do not
550 clear the V bit of the c1 register of CP15.
552 CONFIG_SYS_THUMB_BUILD
554 Use this flag to build U-Boot using the Thumb instruction
555 set for ARM architectures. Thumb instruction set provides
556 better code density. For ARM architectures that support
557 Thumb2 this flag will result in Thumb2 code generated by
560 CONFIG_ARM_ERRATA_716044
561 CONFIG_ARM_ERRATA_742230
562 CONFIG_ARM_ERRATA_743622
563 CONFIG_ARM_ERRATA_751472
565 If set, the workarounds for these ARM errata are applied early
566 during U-Boot startup. Note that these options force the
567 workarounds to be applied; no CPU-type/version detection
568 exists, unlike the similar options in the Linux kernel. Do not
569 set these options unless they apply!
574 The frequency of the timer returned by get_timer().
575 get_timer() must operate in milliseconds and this CONFIG
576 option must be set to 1000.
578 - Linux Kernel Interface:
581 U-Boot stores all clock information in Hz
582 internally. For binary compatibility with older Linux
583 kernels (which expect the clocks passed in the
584 bd_info data to be in MHz) the environment variable
585 "clocks_in_mhz" can be defined so that U-Boot
586 converts clock data to MHZ before passing it to the
588 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
589 "clocks_in_mhz=1" is automatically included in the
592 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
594 When transferring memsize parameter to linux, some versions
595 expect it to be in bytes, others in MB.
596 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
600 New kernel versions are expecting firmware settings to be
601 passed using flattened device trees (based on open firmware
605 * New libfdt-based support
606 * Adds the "fdt" command
607 * The bootm command automatically updates the fdt
609 OF_CPU - The proper name of the cpus node (only required for
610 MPC512X and MPC5xxx based boards).
611 OF_SOC - The proper name of the soc node (only required for
612 MPC512X and MPC5xxx based boards).
613 OF_TBCLK - The timebase frequency.
614 OF_STDOUT_PATH - The path to the console device
616 boards with QUICC Engines require OF_QE to set UCC MAC
619 CONFIG_OF_BOARD_SETUP
621 Board code has addition modification that it wants to make
622 to the flat device tree before handing it off to the kernel
626 This define fills in the correct boot CPU in the boot
627 param header, the default value is zero if undefined.
631 U-Boot can detect if an IDE device is present or not.
632 If not, and this new config option is activated, U-Boot
633 removes the ATA node from the DTS before booting Linux,
634 so the Linux IDE driver does not probe the device and
635 crash. This is needed for buggy hardware (uc101) where
636 no pull down resistor is connected to the signal IDE5V_DD7.
638 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
640 This setting is mandatory for all boards that have only one
641 machine type and must be used to specify the machine type
642 number as it appears in the ARM machine registry
643 (see http://www.arm.linux.org.uk/developer/machines/).
644 Only boards that have multiple machine types supported
645 in a single configuration file and the machine type is
646 runtime discoverable, do not have to use this setting.
648 - vxWorks boot parameters:
650 bootvx constructs a valid bootline using the following
651 environments variables: bootfile, ipaddr, serverip, hostname.
652 It loads the vxWorks image pointed bootfile.
654 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
655 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
656 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
657 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
659 CONFIG_SYS_VXWORKS_ADD_PARAMS
661 Add it at the end of the bootline. E.g "u=username pw=secret"
663 Note: If a "bootargs" environment is defined, it will overwride
664 the defaults discussed just above.
666 - Cache Configuration:
667 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
668 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
669 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
671 - Cache Configuration for ARM:
672 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
674 CONFIG_SYS_PL310_BASE - Physical base address of PL310
675 controller register space
680 Define this if you want support for Amba PrimeCell PL010 UARTs.
684 Define this if you want support for Amba PrimeCell PL011 UARTs.
688 If you have Amba PrimeCell PL011 UARTs, set this variable to
689 the clock speed of the UARTs.
693 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
694 define this to a list of base addresses for each (supported)
695 port. See e.g. include/configs/versatile.h
697 CONFIG_PL011_SERIAL_RLCR
699 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
700 have separate receive and transmit line control registers. Set
701 this variable to initialize the extra register.
703 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
705 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
706 boot loader that has already initialized the UART. Define this
707 variable to flush the UART at init time.
711 Depending on board, define exactly one serial port
712 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
713 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
714 console by defining CONFIG_8xx_CONS_NONE
716 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
717 port routines must be defined elsewhere
718 (i.e. serial_init(), serial_getc(), ...)
721 Enables console device for a color framebuffer. Needs following
722 defines (cf. smiLynxEM, i8042)
723 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
725 VIDEO_HW_RECTFILL graphic chip supports
728 VIDEO_HW_BITBLT graphic chip supports
729 bit-blit (cf. smiLynxEM)
730 VIDEO_VISIBLE_COLS visible pixel columns
732 VIDEO_VISIBLE_ROWS visible pixel rows
733 VIDEO_PIXEL_SIZE bytes per pixel
734 VIDEO_DATA_FORMAT graphic data format
735 (0-5, cf. cfb_console.c)
736 VIDEO_FB_ADRS framebuffer address
737 VIDEO_KBD_INIT_FCT keyboard int fct
738 (i.e. i8042_kbd_init())
739 VIDEO_TSTC_FCT test char fct
741 VIDEO_GETC_FCT get char fct
743 CONFIG_CONSOLE_CURSOR cursor drawing on/off
744 (requires blink timer
746 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
747 CONFIG_CONSOLE_TIME display time/date info in
749 (requires CONFIG_CMD_DATE)
750 CONFIG_VIDEO_LOGO display Linux logo in
752 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
753 linux_logo.h for logo.
754 Requires CONFIG_VIDEO_LOGO
755 CONFIG_CONSOLE_EXTRA_INFO
756 additional board info beside
759 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
760 a limited number of ANSI escape sequences (cursor control,
761 erase functions and limited graphics rendition control).
763 When CONFIG_CFB_CONSOLE is defined, video console is
764 default i/o. Serial console can be forced with
765 environment 'console=serial'.
767 When CONFIG_SILENT_CONSOLE is defined, all console
768 messages (by U-Boot and Linux!) can be silenced with
769 the "silent" environment variable. See
770 doc/README.silent for more information.
772 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
774 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
778 CONFIG_BAUDRATE - in bps
779 Select one of the baudrates listed in
780 CONFIG_SYS_BAUDRATE_TABLE, see below.
781 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
783 - Console Rx buffer length
784 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
785 the maximum receive buffer length for the SMC.
786 This option is actual only for 82xx and 8xx possible.
787 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
788 must be defined, to setup the maximum idle timeout for
791 - Pre-Console Buffer:
792 Prior to the console being initialised (i.e. serial UART
793 initialised etc) all console output is silently discarded.
794 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
795 buffer any console messages prior to the console being
796 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
797 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
798 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
799 bytes are output before the console is initialised, the
800 earlier bytes are discarded.
802 'Sane' compilers will generate smaller code if
803 CONFIG_PRE_CON_BUF_SZ is a power of 2
805 - Safe printf() functions
806 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
807 the printf() functions. These are defined in
808 include/vsprintf.h and include snprintf(), vsnprintf() and
809 so on. Code size increase is approximately 300-500 bytes.
810 If this option is not given then these functions will
811 silently discard their buffer size argument - this means
812 you are not getting any overflow checking in this case.
814 - Boot Delay: CONFIG_BOOTDELAY - in seconds
815 Delay before automatically booting the default image;
816 set to -1 to disable autoboot.
817 set to -2 to autoboot with no delay and not check for abort
818 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
820 See doc/README.autoboot for these options that
821 work with CONFIG_BOOTDELAY. None are required.
822 CONFIG_BOOT_RETRY_TIME
823 CONFIG_BOOT_RETRY_MIN
824 CONFIG_AUTOBOOT_KEYED
825 CONFIG_AUTOBOOT_PROMPT
826 CONFIG_AUTOBOOT_DELAY_STR
827 CONFIG_AUTOBOOT_STOP_STR
828 CONFIG_AUTOBOOT_DELAY_STR2
829 CONFIG_AUTOBOOT_STOP_STR2
830 CONFIG_ZERO_BOOTDELAY_CHECK
831 CONFIG_RESET_TO_RETRY
835 Only needed when CONFIG_BOOTDELAY is enabled;
836 define a command string that is automatically executed
837 when no character is read on the console interface
838 within "Boot Delay" after reset.
841 This can be used to pass arguments to the bootm
842 command. The value of CONFIG_BOOTARGS goes into the
843 environment value "bootargs".
845 CONFIG_RAMBOOT and CONFIG_NFSBOOT
846 The value of these goes into the environment as
847 "ramboot" and "nfsboot" respectively, and can be used
848 as a convenience, when switching between booting from
852 CONFIG_BOOTCOUNT_LIMIT
853 Implements a mechanism for detecting a repeating reboot
855 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
858 If no softreset save registers are found on the hardware
859 "bootcount" is stored in the environment. To prevent a
860 saveenv on all reboots, the environment variable
861 "upgrade_available" is used. If "upgrade_available" is
862 0, "bootcount" is always 0, if "upgrade_available" is
863 1 "bootcount" is incremented in the environment.
864 So the Userspace Applikation must set the "upgrade_available"
865 and "bootcount" variable to 0, if a boot was successfully.
870 When this option is #defined, the existence of the
871 environment variable "preboot" will be checked
872 immediately before starting the CONFIG_BOOTDELAY
873 countdown and/or running the auto-boot command resp.
874 entering interactive mode.
876 This feature is especially useful when "preboot" is
877 automatically generated or modified. For an example
878 see the LWMON board specific code: here "preboot" is
879 modified when the user holds down a certain
880 combination of keys on the (special) keyboard when
883 - Serial Download Echo Mode:
885 If defined to 1, all characters received during a
886 serial download (using the "loads" command) are
887 echoed back. This might be needed by some terminal
888 emulations (like "cu"), but may as well just take
889 time on others. This setting #define's the initial
890 value of the "loads_echo" environment variable.
892 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
894 Select one of the baudrates listed in
895 CONFIG_SYS_BAUDRATE_TABLE, see below.
898 Monitor commands can be included or excluded
899 from the build by using the #include files
900 <config_cmd_all.h> and #undef'ing unwanted
901 commands, or using <config_cmd_default.h>
902 and augmenting with additional #define's
905 The default command configuration includes all commands
906 except those marked below with a "*".
908 CONFIG_CMD_ASKENV * ask for env variable
909 CONFIG_CMD_BDI bdinfo
910 CONFIG_CMD_BEDBUG * Include BedBug Debugger
911 CONFIG_CMD_BMP * BMP support
912 CONFIG_CMD_BSP * Board specific commands
913 CONFIG_CMD_BOOTD bootd
914 CONFIG_CMD_CACHE * icache, dcache
915 CONFIG_CMD_CLK * clock command support
916 CONFIG_CMD_CONSOLE coninfo
917 CONFIG_CMD_CRC32 * crc32
918 CONFIG_CMD_DATE * support for RTC, date/time...
919 CONFIG_CMD_DHCP * DHCP support
920 CONFIG_CMD_DIAG * Diagnostics
921 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
922 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
923 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
924 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
925 CONFIG_CMD_DTT * Digital Therm and Thermostat
926 CONFIG_CMD_ECHO echo arguments
927 CONFIG_CMD_EDITENV edit env variable
928 CONFIG_CMD_EEPROM * EEPROM read/write support
929 CONFIG_CMD_ELF * bootelf, bootvx
930 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
931 CONFIG_CMD_ENV_FLAGS * display details about env flags
932 CONFIG_CMD_ENV_EXISTS * check existence of env variable
933 CONFIG_CMD_EXPORTENV * export the environment
934 CONFIG_CMD_EXT2 * ext2 command support
935 CONFIG_CMD_EXT4 * ext4 command support
936 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
937 that work for multiple fs types
938 CONFIG_CMD_SAVEENV saveenv
939 CONFIG_CMD_FDC * Floppy Disk Support
940 CONFIG_CMD_FAT * FAT command support
941 CONFIG_CMD_FLASH flinfo, erase, protect
942 CONFIG_CMD_FPGA FPGA device initialization support
943 CONFIG_CMD_FUSE * Device fuse support
944 CONFIG_CMD_GETTIME * Get time since boot
945 CONFIG_CMD_GO * the 'go' command (exec code)
946 CONFIG_CMD_GREPENV * search environment
947 CONFIG_CMD_HASH * calculate hash / digest
948 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
949 CONFIG_CMD_I2C * I2C serial bus support
950 CONFIG_CMD_IDE * IDE harddisk support
951 CONFIG_CMD_IMI iminfo
952 CONFIG_CMD_IMLS List all images found in NOR flash
953 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
954 CONFIG_CMD_IMMAP * IMMR dump support
955 CONFIG_CMD_IMPORTENV * import an environment
956 CONFIG_CMD_INI * import data from an ini file into the env
957 CONFIG_CMD_IRQ * irqinfo
958 CONFIG_CMD_ITEST Integer/string test of 2 values
959 CONFIG_CMD_JFFS2 * JFFS2 Support
960 CONFIG_CMD_KGDB * kgdb
961 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
962 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
964 CONFIG_CMD_LOADB loadb
965 CONFIG_CMD_LOADS loads
966 CONFIG_CMD_MD5SUM * print md5 message digest
967 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
968 CONFIG_CMD_MEMINFO * Display detailed memory information
969 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
971 CONFIG_CMD_MEMTEST * mtest
972 CONFIG_CMD_MISC Misc functions like sleep etc
973 CONFIG_CMD_MMC * MMC memory mapped support
974 CONFIG_CMD_MII * MII utility commands
975 CONFIG_CMD_MTDPARTS * MTD partition support
976 CONFIG_CMD_NAND * NAND support
977 CONFIG_CMD_NET bootp, tftpboot, rarpboot
978 CONFIG_CMD_NFS NFS support
979 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
980 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
981 CONFIG_CMD_PCI * pciinfo
982 CONFIG_CMD_PCMCIA * PCMCIA support
983 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
985 CONFIG_CMD_PORTIO * Port I/O
986 CONFIG_CMD_READ * Read raw data from partition
987 CONFIG_CMD_REGINFO * Register dump
988 CONFIG_CMD_RUN run command in env variable
989 CONFIG_CMD_SANDBOX * sb command to access sandbox features
990 CONFIG_CMD_SAVES * save S record dump
991 CONFIG_CMD_SCSI * SCSI Support
992 CONFIG_CMD_SDRAM * print SDRAM configuration information
993 (requires CONFIG_CMD_I2C)
994 CONFIG_CMD_SETGETDCR Support for DCR Register access
996 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
997 CONFIG_CMD_SHA1SUM * print sha1 memory digest
998 (requires CONFIG_CMD_MEMORY)
999 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1000 CONFIG_CMD_SOURCE "source" command Support
1001 CONFIG_CMD_SPI * SPI serial bus support
1002 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1003 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1004 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1005 CONFIG_CMD_TIMER * access to the system tick timer
1006 CONFIG_CMD_USB * USB support
1007 CONFIG_CMD_CDP * Cisco Discover Protocol support
1008 CONFIG_CMD_MFSL * Microblaze FSL support
1009 CONFIG_CMD_XIMG Load part of Multi Image
1012 EXAMPLE: If you want all functions except of network
1013 support you can write:
1015 #include "config_cmd_all.h"
1016 #undef CONFIG_CMD_NET
1019 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1021 Note: Don't enable the "icache" and "dcache" commands
1022 (configuration option CONFIG_CMD_CACHE) unless you know
1023 what you (and your U-Boot users) are doing. Data
1024 cache cannot be enabled on systems like the 8xx or
1025 8260 (where accesses to the IMMR region must be
1026 uncached), and it cannot be disabled on all other
1027 systems where we (mis-) use the data cache to hold an
1028 initial stack and some data.
1031 XXX - this list needs to get updated!
1033 - Regular expression support:
1035 If this variable is defined, U-Boot is linked against
1036 the SLRE (Super Light Regular Expression) library,
1037 which adds regex support to some commands, as for
1038 example "env grep" and "setexpr".
1042 If this variable is defined, U-Boot will use a device tree
1043 to configure its devices, instead of relying on statically
1044 compiled #defines in the board file. This option is
1045 experimental and only available on a few boards. The device
1046 tree is available in the global data as gd->fdt_blob.
1048 U-Boot needs to get its device tree from somewhere. This can
1049 be done using one of the two options below:
1052 If this variable is defined, U-Boot will embed a device tree
1053 binary in its image. This device tree file should be in the
1054 board directory and called <soc>-<board>.dts. The binary file
1055 is then picked up in board_init_f() and made available through
1056 the global data structure as gd->blob.
1059 If this variable is defined, U-Boot will build a device tree
1060 binary. It will be called u-boot.dtb. Architecture-specific
1061 code will locate it at run-time. Generally this works by:
1063 cat u-boot.bin u-boot.dtb >image.bin
1065 and in fact, U-Boot does this for you, creating a file called
1066 u-boot-dtb.bin which is useful in the common case. You can
1067 still use the individual files if you need something more
1072 If this variable is defined, it enables watchdog
1073 support for the SoC. There must be support in the SoC
1074 specific code for a watchdog. For the 8xx and 8260
1075 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1076 register. When supported for a specific SoC is
1077 available, then no further board specific code should
1078 be needed to use it.
1081 When using a watchdog circuitry external to the used
1082 SoC, then define this variable and provide board
1083 specific code for the "hw_watchdog_reset" function.
1086 CONFIG_VERSION_VARIABLE
1087 If this variable is defined, an environment variable
1088 named "ver" is created by U-Boot showing the U-Boot
1089 version as printed by the "version" command.
1090 Any change to this variable will be reverted at the
1095 When CONFIG_CMD_DATE is selected, the type of the RTC
1096 has to be selected, too. Define exactly one of the
1099 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1100 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1101 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1102 CONFIG_RTC_MC146818 - use MC146818 RTC
1103 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1104 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1105 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1106 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1107 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1108 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1109 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1110 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1113 Note that if the RTC uses I2C, then the I2C interface
1114 must also be configured. See I2C Support, below.
1117 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1119 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1120 chip-ngpio pairs that tell the PCA953X driver the number of
1121 pins supported by a particular chip.
1123 Note that if the GPIO device uses I2C, then the I2C interface
1124 must also be configured. See I2C Support, below.
1126 - Timestamp Support:
1128 When CONFIG_TIMESTAMP is selected, the timestamp
1129 (date and time) of an image is printed by image
1130 commands like bootm or iminfo. This option is
1131 automatically enabled when you select CONFIG_CMD_DATE .
1133 - Partition Labels (disklabels) Supported:
1134 Zero or more of the following:
1135 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1136 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1137 Intel architecture, USB sticks, etc.
1138 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1139 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1140 bootloader. Note 2TB partition limit; see
1142 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1144 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1145 CONFIG_CMD_SCSI) you must configure support for at
1146 least one non-MTD partition type as well.
1149 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1150 board configurations files but used nowhere!
1152 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1153 be performed by calling the function
1154 ide_set_reset(int reset)
1155 which has to be defined in a board specific file
1160 Set this to enable ATAPI support.
1165 Set this to enable support for disks larger than 137GB
1166 Also look at CONFIG_SYS_64BIT_LBA.
1167 Whithout these , LBA48 support uses 32bit variables and will 'only'
1168 support disks up to 2.1TB.
1170 CONFIG_SYS_64BIT_LBA:
1171 When enabled, makes the IDE subsystem use 64bit sector addresses.
1175 At the moment only there is only support for the
1176 SYM53C8XX SCSI controller; define
1177 CONFIG_SCSI_SYM53C8XX to enable it.
1179 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1180 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1181 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1182 maximum numbers of LUNs, SCSI ID's and target
1184 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1186 The environment variable 'scsidevs' is set to the number of
1187 SCSI devices found during the last scan.
1189 - NETWORK Support (PCI):
1191 Support for Intel 8254x/8257x gigabit chips.
1194 Utility code for direct access to the SPI bus on Intel 8257x.
1195 This does not do anything useful unless you set at least one
1196 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1198 CONFIG_E1000_SPI_GENERIC
1199 Allow generic access to the SPI bus on the Intel 8257x, for
1200 example with the "sspi" command.
1203 Management command for E1000 devices. When used on devices
1204 with SPI support you can reprogram the EEPROM from U-Boot.
1206 CONFIG_E1000_FALLBACK_MAC
1207 default MAC for empty EEPROM after production.
1210 Support for Intel 82557/82559/82559ER chips.
1211 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1212 write routine for first time initialisation.
1215 Support for Digital 2114x chips.
1216 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1217 modem chip initialisation (KS8761/QS6611).
1220 Support for National dp83815 chips.
1223 Support for National dp8382[01] gigabit chips.
1225 - NETWORK Support (other):
1227 CONFIG_DRIVER_AT91EMAC
1228 Support for AT91RM9200 EMAC.
1231 Define this to use reduced MII inteface
1233 CONFIG_DRIVER_AT91EMAC_QUIET
1234 If this defined, the driver is quiet.
1235 The driver doen't show link status messages.
1237 CONFIG_CALXEDA_XGMAC
1238 Support for the Calxeda XGMAC device
1241 Support for SMSC's LAN91C96 chips.
1243 CONFIG_LAN91C96_BASE
1244 Define this to hold the physical address
1245 of the LAN91C96's I/O space
1247 CONFIG_LAN91C96_USE_32_BIT
1248 Define this to enable 32 bit addressing
1251 Support for SMSC's LAN91C111 chip
1253 CONFIG_SMC91111_BASE
1254 Define this to hold the physical address
1255 of the device (I/O space)
1257 CONFIG_SMC_USE_32_BIT
1258 Define this if data bus is 32 bits
1260 CONFIG_SMC_USE_IOFUNCS
1261 Define this to use i/o functions instead of macros
1262 (some hardware wont work with macros)
1264 CONFIG_DRIVER_TI_EMAC
1265 Support for davinci emac
1267 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1268 Define this if you have more then 3 PHYs.
1271 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1273 CONFIG_FTGMAC100_EGIGA
1274 Define this to use GE link update with gigabit PHY.
1275 Define this if FTGMAC100 is connected to gigabit PHY.
1276 If your system has 10/100 PHY only, it might not occur
1277 wrong behavior. Because PHY usually return timeout or
1278 useless data when polling gigabit status and gigabit
1279 control registers. This behavior won't affect the
1280 correctnessof 10/100 link speed update.
1283 Support for SMSC's LAN911x and LAN921x chips
1286 Define this to hold the physical address
1287 of the device (I/O space)
1289 CONFIG_SMC911X_32_BIT
1290 Define this if data bus is 32 bits
1292 CONFIG_SMC911X_16_BIT
1293 Define this if data bus is 16 bits. If your processor
1294 automatically converts one 32 bit word to two 16 bit
1295 words you may also try CONFIG_SMC911X_32_BIT.
1298 Support for Renesas on-chip Ethernet controller
1300 CONFIG_SH_ETHER_USE_PORT
1301 Define the number of ports to be used
1303 CONFIG_SH_ETHER_PHY_ADDR
1304 Define the ETH PHY's address
1306 CONFIG_SH_ETHER_CACHE_WRITEBACK
1307 If this option is set, the driver enables cache flush.
1311 Support TPM devices.
1314 Support for i2c bus TPM devices. Only one device
1315 per system is supported at this time.
1317 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1318 Define the the i2c bus number for the TPM device
1320 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1321 Define the TPM's address on the i2c bus
1323 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1324 Define the burst count bytes upper limit
1326 CONFIG_TPM_ATMEL_TWI
1327 Support for Atmel TWI TPM device. Requires I2C support.
1330 Support for generic parallel port TPM devices. Only one device
1331 per system is supported at this time.
1333 CONFIG_TPM_TIS_BASE_ADDRESS
1334 Base address where the generic TPM device is mapped
1335 to. Contemporary x86 systems usually map it at
1339 Add tpm monitor functions.
1340 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1341 provides monitor access to authorized functions.
1344 Define this to enable the TPM support library which provides
1345 functional interfaces to some TPM commands.
1346 Requires support for a TPM device.
1348 CONFIG_TPM_AUTH_SESSIONS
1349 Define this to enable authorized functions in the TPM library.
1350 Requires CONFIG_TPM and CONFIG_SHA1.
1353 At the moment only the UHCI host controller is
1354 supported (PIP405, MIP405, MPC5200); define
1355 CONFIG_USB_UHCI to enable it.
1356 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1357 and define CONFIG_USB_STORAGE to enable the USB
1360 Supported are USB Keyboards and USB Floppy drives
1362 MPC5200 USB requires additional defines:
1364 for 528 MHz Clock: 0x0001bbbb
1368 for differential drivers: 0x00001000
1369 for single ended drivers: 0x00005000
1370 for differential drivers on PSC3: 0x00000100
1371 for single ended drivers on PSC3: 0x00004100
1372 CONFIG_SYS_USB_EVENT_POLL
1373 May be defined to allow interrupt polling
1374 instead of using asynchronous interrupts
1376 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1377 txfilltuning field in the EHCI controller on reset.
1379 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1380 interval for usb hub power-on delay.(minimum 100msec)
1383 Define the below if you wish to use the USB console.
1384 Once firmware is rebuilt from a serial console issue the
1385 command "setenv stdin usbtty; setenv stdout usbtty" and
1386 attach your USB cable. The Unix command "dmesg" should print
1387 it has found a new device. The environment variable usbtty
1388 can be set to gserial or cdc_acm to enable your device to
1389 appear to a USB host as a Linux gserial device or a
1390 Common Device Class Abstract Control Model serial device.
1391 If you select usbtty = gserial you should be able to enumerate
1393 # modprobe usbserial vendor=0xVendorID product=0xProductID
1394 else if using cdc_acm, simply setting the environment
1395 variable usbtty to be cdc_acm should suffice. The following
1396 might be defined in YourBoardName.h
1399 Define this to build a UDC device
1402 Define this to have a tty type of device available to
1403 talk to the UDC device
1406 Define this to enable the high speed support for usb
1407 device and usbtty. If this feature is enabled, a routine
1408 int is_usbd_high_speed(void)
1409 also needs to be defined by the driver to dynamically poll
1410 whether the enumeration has succeded at high speed or full
1413 CONFIG_SYS_CONSOLE_IS_IN_ENV
1414 Define this if you want stdin, stdout &/or stderr to
1418 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1419 Derive USB clock from external clock "blah"
1420 - CONFIG_SYS_USB_EXTC_CLK 0x02
1422 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1423 Derive USB clock from brgclk
1424 - CONFIG_SYS_USB_BRG_CLK 0x04
1426 If you have a USB-IF assigned VendorID then you may wish to
1427 define your own vendor specific values either in BoardName.h
1428 or directly in usbd_vendor_info.h. If you don't define
1429 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1430 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1431 should pretend to be a Linux device to it's target host.
1433 CONFIG_USBD_MANUFACTURER
1434 Define this string as the name of your company for
1435 - CONFIG_USBD_MANUFACTURER "my company"
1437 CONFIG_USBD_PRODUCT_NAME
1438 Define this string as the name of your product
1439 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1441 CONFIG_USBD_VENDORID
1442 Define this as your assigned Vendor ID from the USB
1443 Implementors Forum. This *must* be a genuine Vendor ID
1444 to avoid polluting the USB namespace.
1445 - CONFIG_USBD_VENDORID 0xFFFF
1447 CONFIG_USBD_PRODUCTID
1448 Define this as the unique Product ID
1450 - CONFIG_USBD_PRODUCTID 0xFFFF
1452 Some USB device drivers may need to check USB cable attachment.
1453 In this case you can enable following config in BoardName.h:
1454 CONFIG_USB_CABLE_CHECK
1455 This enables function definition:
1456 - usb_cable_connected() in include/usb.h
1457 Implementation of this function is board-specific.
1459 - ULPI Layer Support:
1460 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1461 the generic ULPI layer. The generic layer accesses the ULPI PHY
1462 via the platform viewport, so you need both the genric layer and
1463 the viewport enabled. Currently only Chipidea/ARC based
1464 viewport is supported.
1465 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1466 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1467 If your ULPI phy needs a different reference clock than the
1468 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1469 the appropriate value in Hz.
1472 The MMC controller on the Intel PXA is supported. To
1473 enable this define CONFIG_MMC. The MMC can be
1474 accessed from the boot prompt by mapping the device
1475 to physical memory similar to flash. Command line is
1476 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1477 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1480 Support for Renesas on-chip MMCIF controller
1482 CONFIG_SH_MMCIF_ADDR
1483 Define the base address of MMCIF registers
1486 Define the clock frequency for MMCIF
1488 - USB Device Firmware Update (DFU) class support:
1490 This enables the USB portion of the DFU USB class
1493 This enables the command "dfu" which is used to have
1494 U-Boot create a DFU class device via USB. This command
1495 requires that the "dfu_alt_info" environment variable be
1496 set and define the alt settings to expose to the host.
1499 This enables support for exposing (e)MMC devices via DFU.
1502 This enables support for exposing NAND devices via DFU.
1505 This enables support for exposing RAM via DFU.
1506 Note: DFU spec refer to non-volatile memory usage, but
1507 allow usages beyond the scope of spec - here RAM usage,
1508 one that would help mostly the developer.
1510 CONFIG_SYS_DFU_DATA_BUF_SIZE
1511 Dfu transfer uses a buffer before writing data to the
1512 raw storage device. Make the size (in bytes) of this buffer
1513 configurable. The size of this buffer is also configurable
1514 through the "dfu_bufsiz" environment variable.
1516 CONFIG_SYS_DFU_MAX_FILE_SIZE
1517 When updating files rather than the raw storage device,
1518 we use a static buffer to copy the file into and then write
1519 the buffer once we've been given the whole file. Define
1520 this to the maximum filesize (in bytes) for the buffer.
1521 Default is 4 MiB if undefined.
1523 - Journaling Flash filesystem support:
1524 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1525 CONFIG_JFFS2_NAND_DEV
1526 Define these for a default partition on a NAND device
1528 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1529 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1530 Define these for a default partition on a NOR device
1532 CONFIG_SYS_JFFS_CUSTOM_PART
1533 Define this to create an own partition. You have to provide a
1534 function struct part_info* jffs2_part_info(int part_num)
1536 If you define only one JFFS2 partition you may also want to
1537 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1538 to disable the command chpart. This is the default when you
1539 have not defined a custom partition
1541 - FAT(File Allocation Table) filesystem write function support:
1544 Define this to enable support for saving memory data as a
1545 file in FAT formatted partition.
1547 This will also enable the command "fatwrite" enabling the
1548 user to write files to FAT.
1550 CBFS (Coreboot Filesystem) support
1553 Define this to enable support for reading from a Coreboot
1554 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1560 Define this to enable standard (PC-Style) keyboard
1564 Standard PC keyboard driver with US (is default) and
1565 GERMAN key layout (switch via environment 'keymap=de') support.
1566 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1567 for cfb_console. Supports cursor blinking.
1570 Enables a Chrome OS keyboard using the CROS_EC interface.
1571 This uses CROS_EC to communicate with a second microcontroller
1572 which provides key scans on request.
1577 Define this to enable video support (for output to
1580 CONFIG_VIDEO_CT69000
1582 Enable Chips & Technologies 69000 Video chip
1584 CONFIG_VIDEO_SMI_LYNXEM
1585 Enable Silicon Motion SMI 712/710/810 Video chip. The
1586 video output is selected via environment 'videoout'
1587 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1590 For the CT69000 and SMI_LYNXEM drivers, videomode is
1591 selected via environment 'videomode'. Two different ways
1593 - "videomode=num" 'num' is a standard LiLo mode numbers.
1594 Following standard modes are supported (* is default):
1596 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1597 -------------+---------------------------------------------
1598 8 bits | 0x301* 0x303 0x305 0x161 0x307
1599 15 bits | 0x310 0x313 0x316 0x162 0x319
1600 16 bits | 0x311 0x314 0x317 0x163 0x31A
1601 24 bits | 0x312 0x315 0x318 ? 0x31B
1602 -------------+---------------------------------------------
1603 (i.e. setenv videomode 317; saveenv; reset;)
1605 - "videomode=bootargs" all the video parameters are parsed
1606 from the bootargs. (See drivers/video/videomodes.c)
1609 CONFIG_VIDEO_SED13806
1610 Enable Epson SED13806 driver. This driver supports 8bpp
1611 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1612 or CONFIG_VIDEO_SED13806_16BPP
1615 Enable the Freescale DIU video driver. Reference boards for
1616 SOCs that have a DIU should define this macro to enable DIU
1617 support, and should also define these other macros:
1623 CONFIG_VIDEO_SW_CURSOR
1624 CONFIG_VGA_AS_SINGLE_DEVICE
1626 CONFIG_VIDEO_BMP_LOGO
1628 The DIU driver will look for the 'video-mode' environment
1629 variable, and if defined, enable the DIU as a console during
1630 boot. See the documentation file README.video for a
1631 description of this variable.
1635 Enable the VGA video / BIOS for x86. The alternative if you
1636 are using coreboot is to use the coreboot frame buffer
1643 Define this to enable a custom keyboard support.
1644 This simply calls drv_keyboard_init() which must be
1645 defined in your board-specific files.
1646 The only board using this so far is RBC823.
1648 - LCD Support: CONFIG_LCD
1650 Define this to enable LCD support (for output to LCD
1651 display); also select one of the supported displays
1652 by defining one of these:
1656 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1658 CONFIG_NEC_NL6448AC33:
1660 NEC NL6448AC33-18. Active, color, single scan.
1662 CONFIG_NEC_NL6448BC20
1664 NEC NL6448BC20-08. 6.5", 640x480.
1665 Active, color, single scan.
1667 CONFIG_NEC_NL6448BC33_54
1669 NEC NL6448BC33-54. 10.4", 640x480.
1670 Active, color, single scan.
1674 Sharp 320x240. Active, color, single scan.
1675 It isn't 16x9, and I am not sure what it is.
1677 CONFIG_SHARP_LQ64D341
1679 Sharp LQ64D341 display, 640x480.
1680 Active, color, single scan.
1684 HLD1045 display, 640x480.
1685 Active, color, single scan.
1689 Optrex CBL50840-2 NF-FW 99 22 M5
1691 Hitachi LMG6912RPFC-00T
1695 320x240. Black & white.
1697 Normally display is black on white background; define
1698 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1700 CONFIG_LCD_ALIGNMENT
1702 Normally the LCD is page-aligned (tyically 4KB). If this is
1703 defined then the LCD will be aligned to this value instead.
1704 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1705 here, since it is cheaper to change data cache settings on
1706 a per-section basis.
1708 CONFIG_CONSOLE_SCROLL_LINES
1710 When the console need to be scrolled, this is the number of
1711 lines to scroll by. It defaults to 1. Increasing this makes
1712 the console jump but can help speed up operation when scrolling
1717 Support drawing of RLE8-compressed bitmaps on the LCD.
1721 Enables an 'i2c edid' command which can read EDID
1722 information over I2C from an attached LCD display.
1724 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1726 If this option is set, the environment is checked for
1727 a variable "splashimage". If found, the usual display
1728 of logo, copyright and system information on the LCD
1729 is suppressed and the BMP image at the address
1730 specified in "splashimage" is loaded instead. The
1731 console is redirected to the "nulldev", too. This
1732 allows for a "silent" boot where a splash screen is
1733 loaded very quickly after power-on.
1735 CONFIG_SPLASHIMAGE_GUARD
1737 If this option is set, then U-Boot will prevent the environment
1738 variable "splashimage" from being set to a problematic address
1739 (see README.displaying-bmps and README.arm-unaligned-accesses).
1740 This option is useful for targets where, due to alignment
1741 restrictions, an improperly aligned BMP image will cause a data
1742 abort. If you think you will not have problems with unaligned
1743 accesses (for example because your toolchain prevents them)
1744 there is no need to set this option.
1746 CONFIG_SPLASH_SCREEN_ALIGN
1748 If this option is set the splash image can be freely positioned
1749 on the screen. Environment variable "splashpos" specifies the
1750 position as "x,y". If a positive number is given it is used as
1751 number of pixel from left/top. If a negative number is given it
1752 is used as number of pixel from right/bottom. You can also
1753 specify 'm' for centering the image.
1756 setenv splashpos m,m
1757 => image at center of screen
1759 setenv splashpos 30,20
1760 => image at x = 30 and y = 20
1762 setenv splashpos -10,m
1763 => vertically centered image
1764 at x = dspWidth - bmpWidth - 9
1766 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1768 If this option is set, additionally to standard BMP
1769 images, gzipped BMP images can be displayed via the
1770 splashscreen support or the bmp command.
1772 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1774 If this option is set, 8-bit RLE compressed BMP images
1775 can be displayed via the splashscreen support or the
1778 - Do compresssing for memory range:
1781 If this option is set, it would use zlib deflate method
1782 to compress the specified memory at its best effort.
1784 - Compression support:
1787 Enabled by default to support gzip compressed images.
1791 If this option is set, support for bzip2 compressed
1792 images is included. If not, only uncompressed and gzip
1793 compressed images are supported.
1795 NOTE: the bzip2 algorithm requires a lot of RAM, so
1796 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1801 If this option is set, support for lzma compressed
1804 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1805 requires an amount of dynamic memory that is given by the
1808 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1810 Where lc and lp stand for, respectively, Literal context bits
1811 and Literal pos bits.
1813 This value is upper-bounded by 14MB in the worst case. Anyway,
1814 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1815 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1816 a very small buffer.
1818 Use the lzmainfo tool to determinate the lc and lp values and
1819 then calculate the amount of needed dynamic memory (ensuring
1820 the appropriate CONFIG_SYS_MALLOC_LEN value).
1824 If this option is set, support for LZO compressed images
1830 The address of PHY on MII bus.
1832 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1834 The clock frequency of the MII bus
1838 If this option is set, support for speed/duplex
1839 detection of gigabit PHY is included.
1841 CONFIG_PHY_RESET_DELAY
1843 Some PHY like Intel LXT971A need extra delay after
1844 reset before any MII register access is possible.
1845 For such PHY, set this option to the usec delay
1846 required. (minimum 300usec for LXT971A)
1848 CONFIG_PHY_CMD_DELAY (ppc4xx)
1850 Some PHY like Intel LXT971A need extra delay after
1851 command issued before MII status register can be read
1861 Define a default value for Ethernet address to use
1862 for the respective Ethernet interface, in case this
1863 is not determined automatically.
1868 Define a default value for the IP address to use for
1869 the default Ethernet interface, in case this is not
1870 determined through e.g. bootp.
1871 (Environment variable "ipaddr")
1873 - Server IP address:
1876 Defines a default value for the IP address of a TFTP
1877 server to contact when using the "tftboot" command.
1878 (Environment variable "serverip")
1880 CONFIG_KEEP_SERVERADDR
1882 Keeps the server's MAC address, in the env 'serveraddr'
1883 for passing to bootargs (like Linux's netconsole option)
1885 - Gateway IP address:
1888 Defines a default value for the IP address of the
1889 default router where packets to other networks are
1891 (Environment variable "gatewayip")
1896 Defines a default value for the subnet mask (or
1897 routing prefix) which is used to determine if an IP
1898 address belongs to the local subnet or needs to be
1899 forwarded through a router.
1900 (Environment variable "netmask")
1902 - Multicast TFTP Mode:
1905 Defines whether you want to support multicast TFTP as per
1906 rfc-2090; for example to work with atftp. Lets lots of targets
1907 tftp down the same boot image concurrently. Note: the Ethernet
1908 driver in use must provide a function: mcast() to join/leave a
1911 - BOOTP Recovery Mode:
1912 CONFIG_BOOTP_RANDOM_DELAY
1914 If you have many targets in a network that try to
1915 boot using BOOTP, you may want to avoid that all
1916 systems send out BOOTP requests at precisely the same
1917 moment (which would happen for instance at recovery
1918 from a power failure, when all systems will try to
1919 boot, thus flooding the BOOTP server. Defining
1920 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1921 inserted before sending out BOOTP requests. The
1922 following delays are inserted then:
1924 1st BOOTP request: delay 0 ... 1 sec
1925 2nd BOOTP request: delay 0 ... 2 sec
1926 3rd BOOTP request: delay 0 ... 4 sec
1928 BOOTP requests: delay 0 ... 8 sec
1930 - DHCP Advanced Options:
1931 You can fine tune the DHCP functionality by defining
1932 CONFIG_BOOTP_* symbols:
1934 CONFIG_BOOTP_SUBNETMASK
1935 CONFIG_BOOTP_GATEWAY
1936 CONFIG_BOOTP_HOSTNAME
1937 CONFIG_BOOTP_NISDOMAIN
1938 CONFIG_BOOTP_BOOTPATH
1939 CONFIG_BOOTP_BOOTFILESIZE
1942 CONFIG_BOOTP_SEND_HOSTNAME
1943 CONFIG_BOOTP_NTPSERVER
1944 CONFIG_BOOTP_TIMEOFFSET
1945 CONFIG_BOOTP_VENDOREX
1946 CONFIG_BOOTP_MAY_FAIL
1948 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1949 environment variable, not the BOOTP server.
1951 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1952 after the configured retry count, the call will fail
1953 instead of starting over. This can be used to fail over
1954 to Link-local IP address configuration if the DHCP server
1957 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1958 serverip from a DHCP server, it is possible that more
1959 than one DNS serverip is offered to the client.
1960 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1961 serverip will be stored in the additional environment
1962 variable "dnsip2". The first DNS serverip is always
1963 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1966 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1967 to do a dynamic update of a DNS server. To do this, they
1968 need the hostname of the DHCP requester.
1969 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1970 of the "hostname" environment variable is passed as
1971 option 12 to the DHCP server.
1973 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1975 A 32bit value in microseconds for a delay between
1976 receiving a "DHCP Offer" and sending the "DHCP Request".
1977 This fixes a problem with certain DHCP servers that don't
1978 respond 100% of the time to a "DHCP request". E.g. On an
1979 AT91RM9200 processor running at 180MHz, this delay needed
1980 to be *at least* 15,000 usec before a Windows Server 2003
1981 DHCP server would reply 100% of the time. I recommend at
1982 least 50,000 usec to be safe. The alternative is to hope
1983 that one of the retries will be successful but note that
1984 the DHCP timeout and retry process takes a longer than
1987 - Link-local IP address negotiation:
1988 Negotiate with other link-local clients on the local network
1989 for an address that doesn't require explicit configuration.
1990 This is especially useful if a DHCP server cannot be guaranteed
1991 to exist in all environments that the device must operate.
1993 See doc/README.link-local for more information.
1996 CONFIG_CDP_DEVICE_ID
1998 The device id used in CDP trigger frames.
2000 CONFIG_CDP_DEVICE_ID_PREFIX
2002 A two character string which is prefixed to the MAC address
2007 A printf format string which contains the ascii name of
2008 the port. Normally is set to "eth%d" which sets
2009 eth0 for the first Ethernet, eth1 for the second etc.
2011 CONFIG_CDP_CAPABILITIES
2013 A 32bit integer which indicates the device capabilities;
2014 0x00000010 for a normal host which does not forwards.
2018 An ascii string containing the version of the software.
2022 An ascii string containing the name of the platform.
2026 A 32bit integer sent on the trigger.
2028 CONFIG_CDP_POWER_CONSUMPTION
2030 A 16bit integer containing the power consumption of the
2031 device in .1 of milliwatts.
2033 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2035 A byte containing the id of the VLAN.
2037 - Status LED: CONFIG_STATUS_LED
2039 Several configurations allow to display the current
2040 status using a LED. For instance, the LED will blink
2041 fast while running U-Boot code, stop blinking as
2042 soon as a reply to a BOOTP request was received, and
2043 start blinking slow once the Linux kernel is running
2044 (supported by a status LED driver in the Linux
2045 kernel). Defining CONFIG_STATUS_LED enables this
2051 The status LED can be connected to a GPIO pin.
2052 In such cases, the gpio_led driver can be used as a
2053 status LED backend implementation. Define CONFIG_GPIO_LED
2054 to include the gpio_led driver in the U-Boot binary.
2056 CONFIG_GPIO_LED_INVERTED_TABLE
2057 Some GPIO connected LEDs may have inverted polarity in which
2058 case the GPIO high value corresponds to LED off state and
2059 GPIO low value corresponds to LED on state.
2060 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2061 with a list of GPIO LEDs that have inverted polarity.
2063 - CAN Support: CONFIG_CAN_DRIVER
2065 Defining CONFIG_CAN_DRIVER enables CAN driver support
2066 on those systems that support this (optional)
2067 feature, like the TQM8xxL modules.
2069 - I2C Support: CONFIG_SYS_I2C
2071 This enable the NEW i2c subsystem, and will allow you to use
2072 i2c commands at the u-boot command line (as long as you set
2073 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2074 based realtime clock chips or other i2c devices. See
2075 common/cmd_i2c.c for a description of the command line
2078 ported i2c driver to the new framework:
2079 - drivers/i2c/soft_i2c.c:
2080 - activate first bus with CONFIG_SYS_I2C_SOFT define
2081 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2082 for defining speed and slave address
2083 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2084 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2085 for defining speed and slave address
2086 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2087 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2088 for defining speed and slave address
2089 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2090 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2091 for defining speed and slave address
2093 - drivers/i2c/fsl_i2c.c:
2094 - activate i2c driver with CONFIG_SYS_I2C_FSL
2095 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2096 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2097 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2099 - If your board supports a second fsl i2c bus, define
2100 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2101 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2102 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2105 - drivers/i2c/tegra_i2c.c:
2106 - activate this driver with CONFIG_SYS_I2C_TEGRA
2107 - This driver adds 4 i2c buses with a fix speed from
2108 100000 and the slave addr 0!
2110 - drivers/i2c/ppc4xx_i2c.c
2111 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2112 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2113 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2115 - drivers/i2c/i2c_mxc.c
2116 - activate this driver with CONFIG_SYS_I2C_MXC
2117 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2118 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2119 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2120 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2121 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2122 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2123 If thoses defines are not set, default value is 100000
2124 for speed, and 0 for slave.
2126 - drivers/i2c/rcar_i2c.c:
2127 - activate this driver with CONFIG_SYS_I2C_RCAR
2128 - This driver adds 4 i2c buses
2130 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2131 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2132 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2133 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2134 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2135 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2136 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2137 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2138 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2140 - drivers/i2c/sh_i2c.c:
2141 - activate this driver with CONFIG_SYS_I2C_SH
2142 - This driver adds from 2 to 5 i2c buses
2144 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2145 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2146 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2147 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2148 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2149 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2150 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2151 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2152 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2153 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2154 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2155 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2156 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2158 - drivers/i2c/omap24xx_i2c.c
2159 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2160 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2161 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2162 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2163 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2164 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2165 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2166 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2167 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2168 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2169 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2171 - drivers/i2c/zynq_i2c.c
2172 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2173 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2174 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2176 - drivers/i2c/s3c24x0_i2c.c:
2177 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2178 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2179 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2180 with a fix speed from 100000 and the slave addr 0!
2184 CONFIG_SYS_NUM_I2C_BUSES
2185 Hold the number of i2c busses you want to use. If you
2186 don't use/have i2c muxes on your i2c bus, this
2187 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2190 CONFIG_SYS_I2C_DIRECT_BUS
2191 define this, if you don't use i2c muxes on your hardware.
2192 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2195 CONFIG_SYS_I2C_MAX_HOPS
2196 define how many muxes are maximal consecutively connected
2197 on one i2c bus. If you not use i2c muxes, omit this
2200 CONFIG_SYS_I2C_BUSES
2201 hold a list of busses you want to use, only used if
2202 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2203 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2204 CONFIG_SYS_NUM_I2C_BUSES = 9:
2206 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2207 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2208 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2209 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2210 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2211 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2212 {1, {I2C_NULL_HOP}}, \
2213 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2214 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2218 bus 0 on adapter 0 without a mux
2219 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2220 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2221 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2222 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2223 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2224 bus 6 on adapter 1 without a mux
2225 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2226 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2228 If you do not have i2c muxes on your board, omit this define.
2230 - Legacy I2C Support: CONFIG_HARD_I2C
2232 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2233 provides the following compelling advantages:
2235 - more than one i2c adapter is usable
2236 - approved multibus support
2237 - better i2c mux support
2239 ** Please consider updating your I2C driver now. **
2241 These enable legacy I2C serial bus commands. Defining
2242 CONFIG_HARD_I2C will include the appropriate I2C driver
2243 for the selected CPU.
2245 This will allow you to use i2c commands at the u-boot
2246 command line (as long as you set CONFIG_CMD_I2C in
2247 CONFIG_COMMANDS) and communicate with i2c based realtime
2248 clock chips. See common/cmd_i2c.c for a description of the
2249 command line interface.
2251 CONFIG_HARD_I2C selects a hardware I2C controller.
2253 There are several other quantities that must also be
2254 defined when you define CONFIG_HARD_I2C.
2256 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2257 to be the frequency (in Hz) at which you wish your i2c bus
2258 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2259 the CPU's i2c node address).
2261 Now, the u-boot i2c code for the mpc8xx
2262 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2263 and so its address should therefore be cleared to 0 (See,
2264 eg, MPC823e User's Manual p.16-473). So, set
2265 CONFIG_SYS_I2C_SLAVE to 0.
2267 CONFIG_SYS_I2C_INIT_MPC5XXX
2269 When a board is reset during an i2c bus transfer
2270 chips might think that the current transfer is still
2271 in progress. Reset the slave devices by sending start
2272 commands until the slave device responds.
2274 That's all that's required for CONFIG_HARD_I2C.
2276 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2277 then the following macros need to be defined (examples are
2278 from include/configs/lwmon.h):
2282 (Optional). Any commands necessary to enable the I2C
2283 controller or configure ports.
2285 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2289 (Only for MPC8260 CPU). The I/O port to use (the code
2290 assumes both bits are on the same port). Valid values
2291 are 0..3 for ports A..D.
2295 The code necessary to make the I2C data line active
2296 (driven). If the data line is open collector, this
2299 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2303 The code necessary to make the I2C data line tri-stated
2304 (inactive). If the data line is open collector, this
2307 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2311 Code that returns true if the I2C data line is high,
2314 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2318 If <bit> is true, sets the I2C data line high. If it
2319 is false, it clears it (low).
2321 eg: #define I2C_SDA(bit) \
2322 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2323 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2327 If <bit> is true, sets the I2C clock line high. If it
2328 is false, it clears it (low).
2330 eg: #define I2C_SCL(bit) \
2331 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2332 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2336 This delay is invoked four times per clock cycle so this
2337 controls the rate of data transfer. The data rate thus
2338 is 1 / (I2C_DELAY * 4). Often defined to be something
2341 #define I2C_DELAY udelay(2)
2343 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2345 If your arch supports the generic GPIO framework (asm/gpio.h),
2346 then you may alternatively define the two GPIOs that are to be
2347 used as SCL / SDA. Any of the previous I2C_xxx macros will
2348 have GPIO-based defaults assigned to them as appropriate.
2350 You should define these to the GPIO value as given directly to
2351 the generic GPIO functions.
2353 CONFIG_SYS_I2C_INIT_BOARD
2355 When a board is reset during an i2c bus transfer
2356 chips might think that the current transfer is still
2357 in progress. On some boards it is possible to access
2358 the i2c SCLK line directly, either by using the
2359 processor pin as a GPIO or by having a second pin
2360 connected to the bus. If this option is defined a
2361 custom i2c_init_board() routine in boards/xxx/board.c
2362 is run early in the boot sequence.
2364 CONFIG_SYS_I2C_BOARD_LATE_INIT
2366 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2367 defined a custom i2c_board_late_init() routine in
2368 boards/xxx/board.c is run AFTER the operations in i2c_init()
2369 is completed. This callpoint can be used to unreset i2c bus
2370 using CPU i2c controller register accesses for CPUs whose i2c
2371 controller provide such a method. It is called at the end of
2372 i2c_init() to allow i2c_init operations to setup the i2c bus
2373 controller on the CPU (e.g. setting bus speed & slave address).
2375 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2377 This option enables configuration of bi_iic_fast[] flags
2378 in u-boot bd_info structure based on u-boot environment
2379 variable "i2cfast". (see also i2cfast)
2381 CONFIG_I2C_MULTI_BUS
2383 This option allows the use of multiple I2C buses, each of which
2384 must have a controller. At any point in time, only one bus is
2385 active. To switch to a different bus, use the 'i2c dev' command.
2386 Note that bus numbering is zero-based.
2388 CONFIG_SYS_I2C_NOPROBES
2390 This option specifies a list of I2C devices that will be skipped
2391 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2392 is set, specify a list of bus-device pairs. Otherwise, specify
2393 a 1D array of device addresses
2396 #undef CONFIG_I2C_MULTI_BUS
2397 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2399 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2401 #define CONFIG_I2C_MULTI_BUS
2402 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2404 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2406 CONFIG_SYS_SPD_BUS_NUM
2408 If defined, then this indicates the I2C bus number for DDR SPD.
2409 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2411 CONFIG_SYS_RTC_BUS_NUM
2413 If defined, then this indicates the I2C bus number for the RTC.
2414 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2416 CONFIG_SYS_DTT_BUS_NUM
2418 If defined, then this indicates the I2C bus number for the DTT.
2419 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2421 CONFIG_SYS_I2C_DTT_ADDR:
2423 If defined, specifies the I2C address of the DTT device.
2424 If not defined, then U-Boot uses predefined value for
2425 specified DTT device.
2427 CONFIG_SOFT_I2C_READ_REPEATED_START
2429 defining this will force the i2c_read() function in
2430 the soft_i2c driver to perform an I2C repeated start
2431 between writing the address pointer and reading the
2432 data. If this define is omitted the default behaviour
2433 of doing a stop-start sequence will be used. Most I2C
2434 devices can use either method, but some require one or
2437 - SPI Support: CONFIG_SPI
2439 Enables SPI driver (so far only tested with
2440 SPI EEPROM, also an instance works with Crystal A/D and
2441 D/As on the SACSng board)
2445 Enables the driver for SPI controller on SuperH. Currently
2446 only SH7757 is supported.
2450 Enables extended (16-bit) SPI EEPROM addressing.
2451 (symmetrical to CONFIG_I2C_X)
2455 Enables a software (bit-bang) SPI driver rather than
2456 using hardware support. This is a general purpose
2457 driver that only requires three general I/O port pins
2458 (two outputs, one input) to function. If this is
2459 defined, the board configuration must define several
2460 SPI configuration items (port pins to use, etc). For
2461 an example, see include/configs/sacsng.h.
2465 Enables a hardware SPI driver for general-purpose reads
2466 and writes. As with CONFIG_SOFT_SPI, the board configuration
2467 must define a list of chip-select function pointers.
2468 Currently supported on some MPC8xxx processors. For an
2469 example, see include/configs/mpc8349emds.h.
2473 Enables the driver for the SPI controllers on i.MX and MXC
2474 SoCs. Currently i.MX31/35/51 are supported.
2476 - FPGA Support: CONFIG_FPGA
2478 Enables FPGA subsystem.
2480 CONFIG_FPGA_<vendor>
2482 Enables support for specific chip vendors.
2485 CONFIG_FPGA_<family>
2487 Enables support for FPGA family.
2488 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2492 Specify the number of FPGA devices to support.
2494 CONFIG_SYS_FPGA_PROG_FEEDBACK
2496 Enable printing of hash marks during FPGA configuration.
2498 CONFIG_SYS_FPGA_CHECK_BUSY
2500 Enable checks on FPGA configuration interface busy
2501 status by the configuration function. This option
2502 will require a board or device specific function to
2507 If defined, a function that provides delays in the FPGA
2508 configuration driver.
2510 CONFIG_SYS_FPGA_CHECK_CTRLC
2511 Allow Control-C to interrupt FPGA configuration
2513 CONFIG_SYS_FPGA_CHECK_ERROR
2515 Check for configuration errors during FPGA bitfile
2516 loading. For example, abort during Virtex II
2517 configuration if the INIT_B line goes low (which
2518 indicated a CRC error).
2520 CONFIG_SYS_FPGA_WAIT_INIT
2522 Maximum time to wait for the INIT_B line to deassert
2523 after PROB_B has been deasserted during a Virtex II
2524 FPGA configuration sequence. The default time is 500
2527 CONFIG_SYS_FPGA_WAIT_BUSY
2529 Maximum time to wait for BUSY to deassert during
2530 Virtex II FPGA configuration. The default is 5 ms.
2532 CONFIG_SYS_FPGA_WAIT_CONFIG
2534 Time to wait after FPGA configuration. The default is
2537 - Configuration Management:
2540 If defined, this string will be added to the U-Boot
2541 version information (U_BOOT_VERSION)
2543 - Vendor Parameter Protection:
2545 U-Boot considers the values of the environment
2546 variables "serial#" (Board Serial Number) and
2547 "ethaddr" (Ethernet Address) to be parameters that
2548 are set once by the board vendor / manufacturer, and
2549 protects these variables from casual modification by
2550 the user. Once set, these variables are read-only,
2551 and write or delete attempts are rejected. You can
2552 change this behaviour:
2554 If CONFIG_ENV_OVERWRITE is #defined in your config
2555 file, the write protection for vendor parameters is
2556 completely disabled. Anybody can change or delete
2559 Alternatively, if you #define _both_ CONFIG_ETHADDR
2560 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2561 Ethernet address is installed in the environment,
2562 which can be changed exactly ONCE by the user. [The
2563 serial# is unaffected by this, i. e. it remains
2566 The same can be accomplished in a more flexible way
2567 for any variable by configuring the type of access
2568 to allow for those variables in the ".flags" variable
2569 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2574 Define this variable to enable the reservation of
2575 "protected RAM", i. e. RAM which is not overwritten
2576 by U-Boot. Define CONFIG_PRAM to hold the number of
2577 kB you want to reserve for pRAM. You can overwrite
2578 this default value by defining an environment
2579 variable "pram" to the number of kB you want to
2580 reserve. Note that the board info structure will
2581 still show the full amount of RAM. If pRAM is
2582 reserved, a new environment variable "mem" will
2583 automatically be defined to hold the amount of
2584 remaining RAM in a form that can be passed as boot
2585 argument to Linux, for instance like that:
2587 setenv bootargs ... mem=\${mem}
2590 This way you can tell Linux not to use this memory,
2591 either, which results in a memory region that will
2592 not be affected by reboots.
2594 *WARNING* If your board configuration uses automatic
2595 detection of the RAM size, you must make sure that
2596 this memory test is non-destructive. So far, the
2597 following board configurations are known to be
2600 IVMS8, IVML24, SPD8xx, TQM8xxL,
2601 HERMES, IP860, RPXlite, LWMON,
2604 - Access to physical memory region (> 4GB)
2605 Some basic support is provided for operations on memory not
2606 normally accessible to U-Boot - e.g. some architectures
2607 support access to more than 4GB of memory on 32-bit
2608 machines using physical address extension or similar.
2609 Define CONFIG_PHYSMEM to access this basic support, which
2610 currently only supports clearing the memory.
2615 Define this variable to stop the system in case of a
2616 fatal error, so that you have to reset it manually.
2617 This is probably NOT a good idea for an embedded
2618 system where you want the system to reboot
2619 automatically as fast as possible, but it may be
2620 useful during development since you can try to debug
2621 the conditions that lead to the situation.
2623 CONFIG_NET_RETRY_COUNT
2625 This variable defines the number of retries for
2626 network operations like ARP, RARP, TFTP, or BOOTP
2627 before giving up the operation. If not defined, a
2628 default value of 5 is used.
2632 Timeout waiting for an ARP reply in milliseconds.
2636 Timeout in milliseconds used in NFS protocol.
2637 If you encounter "ERROR: Cannot umount" in nfs command,
2638 try longer timeout such as
2639 #define CONFIG_NFS_TIMEOUT 10000UL
2641 - Command Interpreter:
2642 CONFIG_AUTO_COMPLETE
2644 Enable auto completion of commands using TAB.
2646 Note that this feature has NOT been implemented yet
2647 for the "hush" shell.
2650 CONFIG_SYS_HUSH_PARSER
2652 Define this variable to enable the "hush" shell (from
2653 Busybox) as command line interpreter, thus enabling
2654 powerful command line syntax like
2655 if...then...else...fi conditionals or `&&' and '||'
2656 constructs ("shell scripts").
2658 If undefined, you get the old, much simpler behaviour
2659 with a somewhat smaller memory footprint.
2662 CONFIG_SYS_PROMPT_HUSH_PS2
2664 This defines the secondary prompt string, which is
2665 printed when the command interpreter needs more input
2666 to complete a command. Usually "> ".
2670 In the current implementation, the local variables
2671 space and global environment variables space are
2672 separated. Local variables are those you define by
2673 simply typing `name=value'. To access a local
2674 variable later on, you have write `$name' or
2675 `${name}'; to execute the contents of a variable
2676 directly type `$name' at the command prompt.
2678 Global environment variables are those you use
2679 setenv/printenv to work with. To run a command stored
2680 in such a variable, you need to use the run command,
2681 and you must not use the '$' sign to access them.
2683 To store commands and special characters in a
2684 variable, please use double quotation marks
2685 surrounding the whole text of the variable, instead
2686 of the backslashes before semicolons and special
2689 - Commandline Editing and History:
2690 CONFIG_CMDLINE_EDITING
2692 Enable editing and History functions for interactive
2693 commandline input operations
2695 - Default Environment:
2696 CONFIG_EXTRA_ENV_SETTINGS
2698 Define this to contain any number of null terminated
2699 strings (variable = value pairs) that will be part of
2700 the default environment compiled into the boot image.
2702 For example, place something like this in your
2703 board's config file:
2705 #define CONFIG_EXTRA_ENV_SETTINGS \
2709 Warning: This method is based on knowledge about the
2710 internal format how the environment is stored by the
2711 U-Boot code. This is NOT an official, exported
2712 interface! Although it is unlikely that this format
2713 will change soon, there is no guarantee either.
2714 You better know what you are doing here.
2716 Note: overly (ab)use of the default environment is
2717 discouraged. Make sure to check other ways to preset
2718 the environment like the "source" command or the
2721 CONFIG_ENV_VARS_UBOOT_CONFIG
2723 Define this in order to add variables describing the
2724 U-Boot build configuration to the default environment.
2725 These will be named arch, cpu, board, vendor, and soc.
2727 Enabling this option will cause the following to be defined:
2735 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2737 Define this in order to add variables describing certain
2738 run-time determined information about the hardware to the
2739 environment. These will be named board_name, board_rev.
2741 CONFIG_DELAY_ENVIRONMENT
2743 Normally the environment is loaded when the board is
2744 intialised so that it is available to U-Boot. This inhibits
2745 that so that the environment is not available until
2746 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2747 this is instead controlled by the value of
2748 /config/load-environment.
2750 - DataFlash Support:
2751 CONFIG_HAS_DATAFLASH
2753 Defining this option enables DataFlash features and
2754 allows to read/write in Dataflash via the standard
2757 - Serial Flash support
2760 Defining this option enables SPI flash commands
2761 'sf probe/read/write/erase/update'.
2763 Usage requires an initial 'probe' to define the serial
2764 flash parameters, followed by read/write/erase/update
2767 The following defaults may be provided by the platform
2768 to handle the common case when only a single serial
2769 flash is present on the system.
2771 CONFIG_SF_DEFAULT_BUS Bus identifier
2772 CONFIG_SF_DEFAULT_CS Chip-select
2773 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2774 CONFIG_SF_DEFAULT_SPEED in Hz
2778 Define this option to include a destructive SPI flash
2781 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2783 Define this option to use the Bank addr/Extended addr
2784 support on SPI flashes which has size > 16Mbytes.
2786 CONFIG_SF_DUAL_FLASH Dual flash memories
2788 Define this option to use dual flash support where two flash
2789 memories can be connected with a given cs line.
2790 currently Xilinx Zynq qspi support these type of connections.
2792 - SystemACE Support:
2795 Adding this option adds support for Xilinx SystemACE
2796 chips attached via some sort of local bus. The address
2797 of the chip must also be defined in the
2798 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2800 #define CONFIG_SYSTEMACE
2801 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2803 When SystemACE support is added, the "ace" device type
2804 becomes available to the fat commands, i.e. fatls.
2806 - TFTP Fixed UDP Port:
2809 If this is defined, the environment variable tftpsrcp
2810 is used to supply the TFTP UDP source port value.
2811 If tftpsrcp isn't defined, the normal pseudo-random port
2812 number generator is used.
2814 Also, the environment variable tftpdstp is used to supply
2815 the TFTP UDP destination port value. If tftpdstp isn't
2816 defined, the normal port 69 is used.
2818 The purpose for tftpsrcp is to allow a TFTP server to
2819 blindly start the TFTP transfer using the pre-configured
2820 target IP address and UDP port. This has the effect of
2821 "punching through" the (Windows XP) firewall, allowing
2822 the remainder of the TFTP transfer to proceed normally.
2823 A better solution is to properly configure the firewall,
2824 but sometimes that is not allowed.
2829 This enables a generic 'hash' command which can produce
2830 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2834 Enable the hash verify command (hash -v). This adds to code
2837 CONFIG_SHA1 - support SHA1 hashing
2838 CONFIG_SHA256 - support SHA256 hashing
2840 Note: There is also a sha1sum command, which should perhaps
2841 be deprecated in favour of 'hash sha1'.
2843 - Freescale i.MX specific commands:
2844 CONFIG_CMD_HDMIDETECT
2845 This enables 'hdmidet' command which returns true if an
2846 HDMI monitor is detected. This command is i.MX 6 specific.
2849 This enables the 'bmode' (bootmode) command for forcing
2850 a boot from specific media.
2852 This is useful for forcing the ROM's usb downloader to
2853 activate upon a watchdog reset which is nice when iterating
2854 on U-Boot. Using the reset button or running bmode normal
2855 will set it back to normal. This command currently
2856 supports i.MX53 and i.MX6.
2861 This enables the RSA algorithm used for FIT image verification
2862 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2864 The signing part is build into mkimage regardless of this
2867 - bootcount support:
2868 CONFIG_BOOTCOUNT_LIMIT
2870 This enables the bootcounter support, see:
2871 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2874 enable special bootcounter support on at91sam9xe based boards.
2876 enable special bootcounter support on blackfin based boards.
2878 enable special bootcounter support on da850 based boards.
2879 CONFIG_BOOTCOUNT_RAM
2880 enable support for the bootcounter in RAM
2881 CONFIG_BOOTCOUNT_I2C
2882 enable support for the bootcounter on an i2c (like RTC) device.
2883 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2884 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2886 CONFIG_BOOTCOUNT_ALEN = address len
2888 - Show boot progress:
2889 CONFIG_SHOW_BOOT_PROGRESS
2891 Defining this option allows to add some board-
2892 specific code (calling a user-provided function
2893 "show_boot_progress(int)") that enables you to show
2894 the system's boot progress on some display (for
2895 example, some LED's) on your board. At the moment,
2896 the following checkpoints are implemented:
2898 - Detailed boot stage timing
2900 Define this option to get detailed timing of each stage
2901 of the boot process.
2903 CONFIG_BOOTSTAGE_USER_COUNT
2904 This is the number of available user bootstage records.
2905 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2906 a new ID will be allocated from this stash. If you exceed
2907 the limit, recording will stop.
2909 CONFIG_BOOTSTAGE_REPORT
2910 Define this to print a report before boot, similar to this:
2912 Timer summary in microseconds:
2915 3,575,678 3,575,678 board_init_f start
2916 3,575,695 17 arch_cpu_init A9
2917 3,575,777 82 arch_cpu_init done
2918 3,659,598 83,821 board_init_r start
2919 3,910,375 250,777 main_loop
2920 29,916,167 26,005,792 bootm_start
2921 30,361,327 445,160 start_kernel
2923 CONFIG_CMD_BOOTSTAGE
2924 Add a 'bootstage' command which supports printing a report
2925 and un/stashing of bootstage data.
2927 CONFIG_BOOTSTAGE_FDT
2928 Stash the bootstage information in the FDT. A root 'bootstage'
2929 node is created with each bootstage id as a child. Each child
2930 has a 'name' property and either 'mark' containing the
2931 mark time in microsecond, or 'accum' containing the
2932 accumulated time for that bootstage id in microseconds.
2937 name = "board_init_f";
2946 Code in the Linux kernel can find this in /proc/devicetree.
2948 Legacy uImage format:
2951 1 common/cmd_bootm.c before attempting to boot an image
2952 -1 common/cmd_bootm.c Image header has bad magic number
2953 2 common/cmd_bootm.c Image header has correct magic number
2954 -2 common/cmd_bootm.c Image header has bad checksum
2955 3 common/cmd_bootm.c Image header has correct checksum
2956 -3 common/cmd_bootm.c Image data has bad checksum
2957 4 common/cmd_bootm.c Image data has correct checksum
2958 -4 common/cmd_bootm.c Image is for unsupported architecture
2959 5 common/cmd_bootm.c Architecture check OK
2960 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2961 6 common/cmd_bootm.c Image Type check OK
2962 -6 common/cmd_bootm.c gunzip uncompression error
2963 -7 common/cmd_bootm.c Unimplemented compression type
2964 7 common/cmd_bootm.c Uncompression OK
2965 8 common/cmd_bootm.c No uncompress/copy overwrite error
2966 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2968 9 common/image.c Start initial ramdisk verification
2969 -10 common/image.c Ramdisk header has bad magic number
2970 -11 common/image.c Ramdisk header has bad checksum
2971 10 common/image.c Ramdisk header is OK
2972 -12 common/image.c Ramdisk data has bad checksum
2973 11 common/image.c Ramdisk data has correct checksum
2974 12 common/image.c Ramdisk verification complete, start loading
2975 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2976 13 common/image.c Start multifile image verification
2977 14 common/image.c No initial ramdisk, no multifile, continue.
2979 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2981 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2982 -31 post/post.c POST test failed, detected by post_output_backlog()
2983 -32 post/post.c POST test failed, detected by post_run_single()
2985 34 common/cmd_doc.c before loading a Image from a DOC device
2986 -35 common/cmd_doc.c Bad usage of "doc" command
2987 35 common/cmd_doc.c correct usage of "doc" command
2988 -36 common/cmd_doc.c No boot device
2989 36 common/cmd_doc.c correct boot device
2990 -37 common/cmd_doc.c Unknown Chip ID on boot device
2991 37 common/cmd_doc.c correct chip ID found, device available
2992 -38 common/cmd_doc.c Read Error on boot device
2993 38 common/cmd_doc.c reading Image header from DOC device OK
2994 -39 common/cmd_doc.c Image header has bad magic number
2995 39 common/cmd_doc.c Image header has correct magic number
2996 -40 common/cmd_doc.c Error reading Image from DOC device
2997 40 common/cmd_doc.c Image header has correct magic number
2998 41 common/cmd_ide.c before loading a Image from a IDE device
2999 -42 common/cmd_ide.c Bad usage of "ide" command
3000 42 common/cmd_ide.c correct usage of "ide" command
3001 -43 common/cmd_ide.c No boot device
3002 43 common/cmd_ide.c boot device found
3003 -44 common/cmd_ide.c Device not available
3004 44 common/cmd_ide.c Device available
3005 -45 common/cmd_ide.c wrong partition selected
3006 45 common/cmd_ide.c partition selected
3007 -46 common/cmd_ide.c Unknown partition table
3008 46 common/cmd_ide.c valid partition table found
3009 -47 common/cmd_ide.c Invalid partition type
3010 47 common/cmd_ide.c correct partition type
3011 -48 common/cmd_ide.c Error reading Image Header on boot device
3012 48 common/cmd_ide.c reading Image Header from IDE device OK
3013 -49 common/cmd_ide.c Image header has bad magic number
3014 49 common/cmd_ide.c Image header has correct magic number
3015 -50 common/cmd_ide.c Image header has bad checksum
3016 50 common/cmd_ide.c Image header has correct checksum
3017 -51 common/cmd_ide.c Error reading Image from IDE device
3018 51 common/cmd_ide.c reading Image from IDE device OK
3019 52 common/cmd_nand.c before loading a Image from a NAND device
3020 -53 common/cmd_nand.c Bad usage of "nand" command
3021 53 common/cmd_nand.c correct usage of "nand" command
3022 -54 common/cmd_nand.c No boot device
3023 54 common/cmd_nand.c boot device found
3024 -55 common/cmd_nand.c Unknown Chip ID on boot device
3025 55 common/cmd_nand.c correct chip ID found, device available
3026 -56 common/cmd_nand.c Error reading Image Header on boot device
3027 56 common/cmd_nand.c reading Image Header from NAND device OK
3028 -57 common/cmd_nand.c Image header has bad magic number
3029 57 common/cmd_nand.c Image header has correct magic number
3030 -58 common/cmd_nand.c Error reading Image from NAND device
3031 58 common/cmd_nand.c reading Image from NAND device OK
3033 -60 common/env_common.c Environment has a bad CRC, using default
3035 64 net/eth.c starting with Ethernet configuration.
3036 -64 net/eth.c no Ethernet found.
3037 65 net/eth.c Ethernet found.
3039 -80 common/cmd_net.c usage wrong
3040 80 common/cmd_net.c before calling NetLoop()
3041 -81 common/cmd_net.c some error in NetLoop() occurred
3042 81 common/cmd_net.c NetLoop() back without error
3043 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3044 82 common/cmd_net.c trying automatic boot
3045 83 common/cmd_net.c running "source" command
3046 -83 common/cmd_net.c some error in automatic boot or "source" command
3047 84 common/cmd_net.c end without errors
3052 100 common/cmd_bootm.c Kernel FIT Image has correct format
3053 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3054 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3055 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3056 102 common/cmd_bootm.c Kernel unit name specified
3057 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3058 103 common/cmd_bootm.c Found configuration node
3059 104 common/cmd_bootm.c Got kernel subimage node offset
3060 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3061 105 common/cmd_bootm.c Kernel subimage hash verification OK
3062 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3063 106 common/cmd_bootm.c Architecture check OK
3064 -106 common/cmd_bootm.c Kernel subimage has wrong type
3065 107 common/cmd_bootm.c Kernel subimage type OK
3066 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3067 108 common/cmd_bootm.c Got kernel subimage data/size
3068 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3069 -109 common/cmd_bootm.c Can't get kernel subimage type
3070 -110 common/cmd_bootm.c Can't get kernel subimage comp
3071 -111 common/cmd_bootm.c Can't get kernel subimage os
3072 -112 common/cmd_bootm.c Can't get kernel subimage load address
3073 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3075 120 common/image.c Start initial ramdisk verification
3076 -120 common/image.c Ramdisk FIT image has incorrect format
3077 121 common/image.c Ramdisk FIT image has correct format
3078 122 common/image.c No ramdisk subimage unit name, using configuration
3079 -122 common/image.c Can't get configuration for ramdisk subimage
3080 123 common/image.c Ramdisk unit name specified
3081 -124 common/image.c Can't get ramdisk subimage node offset
3082 125 common/image.c Got ramdisk subimage node offset
3083 -125 common/image.c Ramdisk subimage hash verification failed
3084 126 common/image.c Ramdisk subimage hash verification OK
3085 -126 common/image.c Ramdisk subimage for unsupported architecture
3086 127 common/image.c Architecture check OK
3087 -127 common/image.c Can't get ramdisk subimage data/size
3088 128 common/image.c Got ramdisk subimage data/size
3089 129 common/image.c Can't get ramdisk load address
3090 -129 common/image.c Got ramdisk load address
3092 -130 common/cmd_doc.c Incorrect FIT image format
3093 131 common/cmd_doc.c FIT image format OK
3095 -140 common/cmd_ide.c Incorrect FIT image format
3096 141 common/cmd_ide.c FIT image format OK
3098 -150 common/cmd_nand.c Incorrect FIT image format
3099 151 common/cmd_nand.c FIT image format OK
3101 - FIT image support:
3103 Enable support for the FIT uImage format.
3105 CONFIG_FIT_BEST_MATCH
3106 When no configuration is explicitly selected, default to the
3107 one whose fdt's compatibility field best matches that of
3108 U-Boot itself. A match is considered "best" if it matches the
3109 most specific compatibility entry of U-Boot's fdt's root node.
3110 The order of entries in the configuration's fdt is ignored.
3112 CONFIG_FIT_SIGNATURE
3113 This option enables signature verification of FIT uImages,
3114 using a hash signed and verified using RSA. See
3115 doc/uImage.FIT/signature.txt for more details.
3117 - Standalone program support:
3118 CONFIG_STANDALONE_LOAD_ADDR
3120 This option defines a board specific value for the
3121 address where standalone program gets loaded, thus
3122 overwriting the architecture dependent default
3125 - Frame Buffer Address:
3128 Define CONFIG_FB_ADDR if you want to use specific
3129 address for frame buffer. This is typically the case
3130 when using a graphics controller has separate video
3131 memory. U-Boot will then place the frame buffer at
3132 the given address instead of dynamically reserving it
3133 in system RAM by calling lcd_setmem(), which grabs
3134 the memory for the frame buffer depending on the
3135 configured panel size.
3137 Please see board_init_f function.
3139 - Automatic software updates via TFTP server
3141 CONFIG_UPDATE_TFTP_CNT_MAX
3142 CONFIG_UPDATE_TFTP_MSEC_MAX
3144 These options enable and control the auto-update feature;
3145 for a more detailed description refer to doc/README.update.
3147 - MTD Support (mtdparts command, UBI support)
3150 Adds the MTD device infrastructure from the Linux kernel.
3151 Needed for mtdparts command support.
3153 CONFIG_MTD_PARTITIONS
3155 Adds the MTD partitioning infrastructure from the Linux
3156 kernel. Needed for UBI support.
3161 Adds commands for interacting with MTD partitions formatted
3162 with the UBI flash translation layer
3164 Requires also defining CONFIG_RBTREE
3166 CONFIG_UBI_SILENCE_MSG
3168 Make the verbose messages from UBI stop printing. This leaves
3169 warnings and errors enabled.
3174 Adds commands for interacting with UBI volumes formatted as
3175 UBIFS. UBIFS is read-only in u-boot.
3177 Requires UBI support as well as CONFIG_LZO
3179 CONFIG_UBIFS_SILENCE_MSG
3181 Make the verbose messages from UBIFS stop printing. This leaves
3182 warnings and errors enabled.
3186 Enable building of SPL globally.
3189 LDSCRIPT for linking the SPL binary.
3191 CONFIG_SPL_MAX_FOOTPRINT
3192 Maximum size in memory allocated to the SPL, BSS included.
3193 When defined, the linker checks that the actual memory
3194 used by SPL from _start to __bss_end does not exceed it.
3195 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3196 must not be both defined at the same time.
3199 Maximum size of the SPL image (text, data, rodata, and
3200 linker lists sections), BSS excluded.
3201 When defined, the linker checks that the actual size does
3204 CONFIG_SPL_TEXT_BASE
3205 TEXT_BASE for linking the SPL binary.
3207 CONFIG_SPL_RELOC_TEXT_BASE
3208 Address to relocate to. If unspecified, this is equal to
3209 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3211 CONFIG_SPL_BSS_START_ADDR
3212 Link address for the BSS within the SPL binary.
3214 CONFIG_SPL_BSS_MAX_SIZE
3215 Maximum size in memory allocated to the SPL BSS.
3216 When defined, the linker checks that the actual memory used
3217 by SPL from __bss_start to __bss_end does not exceed it.
3218 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3219 must not be both defined at the same time.
3222 Adress of the start of the stack SPL will use
3224 CONFIG_SPL_RELOC_STACK
3225 Adress of the start of the stack SPL will use after
3226 relocation. If unspecified, this is equal to
3229 CONFIG_SYS_SPL_MALLOC_START
3230 Starting address of the malloc pool used in SPL.
3232 CONFIG_SYS_SPL_MALLOC_SIZE
3233 The size of the malloc pool used in SPL.
3235 CONFIG_SPL_FRAMEWORK
3236 Enable the SPL framework under common/. This framework
3237 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3238 NAND loading of the Linux Kernel.
3240 CONFIG_SPL_DISPLAY_PRINT
3241 For ARM, enable an optional function to print more information
3242 about the running system.
3244 CONFIG_SPL_INIT_MINIMAL
3245 Arch init code should be built for a very small image
3247 CONFIG_SPL_LIBCOMMON_SUPPORT
3248 Support for common/libcommon.o in SPL binary
3250 CONFIG_SPL_LIBDISK_SUPPORT
3251 Support for disk/libdisk.o in SPL binary
3253 CONFIG_SPL_I2C_SUPPORT
3254 Support for drivers/i2c/libi2c.o in SPL binary
3256 CONFIG_SPL_GPIO_SUPPORT
3257 Support for drivers/gpio/libgpio.o in SPL binary
3259 CONFIG_SPL_MMC_SUPPORT
3260 Support for drivers/mmc/libmmc.o in SPL binary
3262 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3263 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3264 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3265 Address, size and partition on the MMC to load U-Boot from
3266 when the MMC is being used in raw mode.
3268 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3269 Sector to load kernel uImage from when MMC is being
3270 used in raw mode (for Falcon mode)
3272 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3273 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3274 Sector and number of sectors to load kernel argument
3275 parameters from when MMC is being used in raw mode
3278 CONFIG_SPL_FAT_SUPPORT
3279 Support for fs/fat/libfat.o in SPL binary
3281 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3282 Filename to read to load U-Boot when reading from FAT
3284 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3285 Filename to read to load kernel uImage when reading
3286 from FAT (for Falcon mode)
3288 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3289 Filename to read to load kernel argument parameters
3290 when reading from FAT (for Falcon mode)
3292 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3293 Set this for NAND SPL on PPC mpc83xx targets, so that
3294 start.S waits for the rest of the SPL to load before
3295 continuing (the hardware starts execution after just
3296 loading the first page rather than the full 4K).
3298 CONFIG_SPL_NAND_BASE
3299 Include nand_base.c in the SPL. Requires
3300 CONFIG_SPL_NAND_DRIVERS.
3302 CONFIG_SPL_NAND_DRIVERS
3303 SPL uses normal NAND drivers, not minimal drivers.
3306 Include standard software ECC in the SPL
3308 CONFIG_SPL_NAND_SIMPLE
3309 Support for NAND boot using simple NAND drivers that
3310 expose the cmd_ctrl() interface.
3312 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3313 Set for the SPL on PPC mpc8xxx targets, support for
3314 drivers/ddr/fsl/libddr.o in SPL binary.
3316 CONFIG_SPL_COMMON_INIT_DDR
3317 Set for common ddr init with serial presence detect in
3320 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3321 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3322 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3323 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3324 CONFIG_SYS_NAND_ECCBYTES
3325 Defines the size and behavior of the NAND that SPL uses
3328 CONFIG_SPL_NAND_BOOT
3329 Add support NAND boot
3331 CONFIG_SYS_NAND_U_BOOT_OFFS
3332 Location in NAND to read U-Boot from
3334 CONFIG_SYS_NAND_U_BOOT_DST
3335 Location in memory to load U-Boot to
3337 CONFIG_SYS_NAND_U_BOOT_SIZE
3338 Size of image to load
3340 CONFIG_SYS_NAND_U_BOOT_START
3341 Entry point in loaded image to jump to
3343 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3344 Define this if you need to first read the OOB and then the
3345 data. This is used for example on davinci plattforms.
3347 CONFIG_SPL_OMAP3_ID_NAND
3348 Support for an OMAP3-specific set of functions to return the
3349 ID and MFR of the first attached NAND chip, if present.
3351 CONFIG_SPL_SERIAL_SUPPORT
3352 Support for drivers/serial/libserial.o in SPL binary
3354 CONFIG_SPL_SPI_FLASH_SUPPORT
3355 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3357 CONFIG_SPL_SPI_SUPPORT
3358 Support for drivers/spi/libspi.o in SPL binary
3360 CONFIG_SPL_RAM_DEVICE
3361 Support for running image already present in ram, in SPL binary
3363 CONFIG_SPL_LIBGENERIC_SUPPORT
3364 Support for lib/libgeneric.o in SPL binary
3366 CONFIG_SPL_ENV_SUPPORT
3367 Support for the environment operating in SPL binary
3369 CONFIG_SPL_NET_SUPPORT
3370 Support for the net/libnet.o in SPL binary.
3371 It conflicts with SPL env from storage medium specified by
3372 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3375 Image offset to which the SPL should be padded before appending
3376 the SPL payload. By default, this is defined as
3377 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3378 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3379 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3382 Final target image containing SPL and payload. Some SPLs
3383 use an arch-specific makefile fragment instead, for
3384 example if more than one image needs to be produced.
3386 CONFIG_FIT_SPL_PRINT
3387 Printing information about a FIT image adds quite a bit of
3388 code to SPL. So this is normally disabled in SPL. Use this
3389 option to re-enable it. This will affect the output of the
3390 bootm command when booting a FIT image.
3394 Enable building of TPL globally.
3397 Image offset to which the TPL should be padded before appending
3398 the TPL payload. By default, this is defined as
3399 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3400 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3401 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3406 [so far only for SMDK2400 boards]
3408 - Modem support enable:
3409 CONFIG_MODEM_SUPPORT
3411 - RTS/CTS Flow control enable:
3414 - Modem debug support:
3415 CONFIG_MODEM_SUPPORT_DEBUG
3417 Enables debugging stuff (char screen[1024], dbg())
3418 for modem support. Useful only with BDI2000.
3420 - Interrupt support (PPC):
3422 There are common interrupt_init() and timer_interrupt()
3423 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3424 for CPU specific initialization. interrupt_init_cpu()
3425 should set decrementer_count to appropriate value. If
3426 CPU resets decrementer automatically after interrupt
3427 (ppc4xx) it should set decrementer_count to zero.
3428 timer_interrupt() calls timer_interrupt_cpu() for CPU
3429 specific handling. If board has watchdog / status_led
3430 / other_activity_monitor it works automatically from
3431 general timer_interrupt().
3435 In the target system modem support is enabled when a
3436 specific key (key combination) is pressed during
3437 power-on. Otherwise U-Boot will boot normally
3438 (autoboot). The key_pressed() function is called from
3439 board_init(). Currently key_pressed() is a dummy
3440 function, returning 1 and thus enabling modem
3443 If there are no modem init strings in the
3444 environment, U-Boot proceed to autoboot; the
3445 previous output (banner, info printfs) will be
3448 See also: doc/README.Modem
3450 Board initialization settings:
3451 ------------------------------
3453 During Initialization u-boot calls a number of board specific functions
3454 to allow the preparation of board specific prerequisites, e.g. pin setup
3455 before drivers are initialized. To enable these callbacks the
3456 following configuration macros have to be defined. Currently this is
3457 architecture specific, so please check arch/your_architecture/lib/board.c
3458 typically in board_init_f() and board_init_r().
3460 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3461 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3462 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3463 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3465 Configuration Settings:
3466 -----------------------
3468 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3469 undefine this when you're short of memory.
3471 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3472 width of the commands listed in the 'help' command output.
3474 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3475 prompt for user input.
3477 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3479 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3481 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3483 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3484 the application (usually a Linux kernel) when it is
3487 - CONFIG_SYS_BAUDRATE_TABLE:
3488 List of legal baudrate settings for this board.
3490 - CONFIG_SYS_CONSOLE_INFO_QUIET
3491 Suppress display of console information at boot.
3493 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3494 If the board specific function
3495 extern int overwrite_console (void);
3496 returns 1, the stdin, stderr and stdout are switched to the
3497 serial port, else the settings in the environment are used.
3499 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3500 Enable the call to overwrite_console().
3502 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3503 Enable overwrite of previous console environment settings.
3505 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3506 Begin and End addresses of the area used by the
3509 - CONFIG_SYS_ALT_MEMTEST:
3510 Enable an alternate, more extensive memory test.
3512 - CONFIG_SYS_MEMTEST_SCRATCH:
3513 Scratch address used by the alternate memory test
3514 You only need to set this if address zero isn't writeable
3516 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3517 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3518 this specified memory area will get subtracted from the top
3519 (end) of RAM and won't get "touched" at all by U-Boot. By
3520 fixing up gd->ram_size the Linux kernel should gets passed
3521 the now "corrected" memory size and won't touch it either.
3522 This should work for arch/ppc and arch/powerpc. Only Linux
3523 board ports in arch/powerpc with bootwrapper support that
3524 recalculate the memory size from the SDRAM controller setup
3525 will have to get fixed in Linux additionally.
3527 This option can be used as a workaround for the 440EPx/GRx
3528 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3531 WARNING: Please make sure that this value is a multiple of
3532 the Linux page size (normally 4k). If this is not the case,
3533 then the end address of the Linux memory will be located at a
3534 non page size aligned address and this could cause major
3537 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3538 Enable temporary baudrate change while serial download
3540 - CONFIG_SYS_SDRAM_BASE:
3541 Physical start address of SDRAM. _Must_ be 0 here.
3543 - CONFIG_SYS_MBIO_BASE:
3544 Physical start address of Motherboard I/O (if using a
3547 - CONFIG_SYS_FLASH_BASE:
3548 Physical start address of Flash memory.
3550 - CONFIG_SYS_MONITOR_BASE:
3551 Physical start address of boot monitor code (set by
3552 make config files to be same as the text base address
3553 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3554 CONFIG_SYS_FLASH_BASE when booting from flash.
3556 - CONFIG_SYS_MONITOR_LEN:
3557 Size of memory reserved for monitor code, used to
3558 determine _at_compile_time_ (!) if the environment is
3559 embedded within the U-Boot image, or in a separate
3562 - CONFIG_SYS_MALLOC_LEN:
3563 Size of DRAM reserved for malloc() use.
3565 - CONFIG_SYS_BOOTM_LEN:
3566 Normally compressed uImages are limited to an
3567 uncompressed size of 8 MBytes. If this is not enough,
3568 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3569 to adjust this setting to your needs.
3571 - CONFIG_SYS_BOOTMAPSZ:
3572 Maximum size of memory mapped by the startup code of
3573 the Linux kernel; all data that must be processed by
3574 the Linux kernel (bd_info, boot arguments, FDT blob if
3575 used) must be put below this limit, unless "bootm_low"
3576 environment variable is defined and non-zero. In such case
3577 all data for the Linux kernel must be between "bootm_low"
3578 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3579 variable "bootm_mapsize" will override the value of
3580 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3581 then the value in "bootm_size" will be used instead.
3583 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3584 Enable initrd_high functionality. If defined then the
3585 initrd_high feature is enabled and the bootm ramdisk subcommand
3588 - CONFIG_SYS_BOOT_GET_CMDLINE:
3589 Enables allocating and saving kernel cmdline in space between
3590 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3592 - CONFIG_SYS_BOOT_GET_KBD:
3593 Enables allocating and saving a kernel copy of the bd_info in
3594 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3596 - CONFIG_SYS_MAX_FLASH_BANKS:
3597 Max number of Flash memory banks
3599 - CONFIG_SYS_MAX_FLASH_SECT:
3600 Max number of sectors on a Flash chip
3602 - CONFIG_SYS_FLASH_ERASE_TOUT:
3603 Timeout for Flash erase operations (in ms)
3605 - CONFIG_SYS_FLASH_WRITE_TOUT:
3606 Timeout for Flash write operations (in ms)
3608 - CONFIG_SYS_FLASH_LOCK_TOUT
3609 Timeout for Flash set sector lock bit operation (in ms)
3611 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3612 Timeout for Flash clear lock bits operation (in ms)
3614 - CONFIG_SYS_FLASH_PROTECTION
3615 If defined, hardware flash sectors protection is used
3616 instead of U-Boot software protection.
3618 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3620 Enable TFTP transfers directly to flash memory;
3621 without this option such a download has to be
3622 performed in two steps: (1) download to RAM, and (2)
3623 copy from RAM to flash.
3625 The two-step approach is usually more reliable, since
3626 you can check if the download worked before you erase
3627 the flash, but in some situations (when system RAM is
3628 too limited to allow for a temporary copy of the
3629 downloaded image) this option may be very useful.
3631 - CONFIG_SYS_FLASH_CFI:
3632 Define if the flash driver uses extra elements in the
3633 common flash structure for storing flash geometry.
3635 - CONFIG_FLASH_CFI_DRIVER
3636 This option also enables the building of the cfi_flash driver
3637 in the drivers directory
3639 - CONFIG_FLASH_CFI_MTD
3640 This option enables the building of the cfi_mtd driver
3641 in the drivers directory. The driver exports CFI flash
3644 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3645 Use buffered writes to flash.
3647 - CONFIG_FLASH_SPANSION_S29WS_N
3648 s29ws-n MirrorBit flash has non-standard addresses for buffered
3651 - CONFIG_SYS_FLASH_QUIET_TEST
3652 If this option is defined, the common CFI flash doesn't
3653 print it's warning upon not recognized FLASH banks. This
3654 is useful, if some of the configured banks are only
3655 optionally available.
3657 - CONFIG_FLASH_SHOW_PROGRESS
3658 If defined (must be an integer), print out countdown
3659 digits and dots. Recommended value: 45 (9..1) for 80
3660 column displays, 15 (3..1) for 40 column displays.
3662 - CONFIG_FLASH_VERIFY
3663 If defined, the content of the flash (destination) is compared
3664 against the source after the write operation. An error message
3665 will be printed when the contents are not identical.
3666 Please note that this option is useless in nearly all cases,
3667 since such flash programming errors usually are detected earlier
3668 while unprotecting/erasing/programming. Please only enable
3669 this option if you really know what you are doing.
3671 - CONFIG_SYS_RX_ETH_BUFFER:
3672 Defines the number of Ethernet receive buffers. On some
3673 Ethernet controllers it is recommended to set this value
3674 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3675 buffers can be full shortly after enabling the interface
3676 on high Ethernet traffic.
3677 Defaults to 4 if not defined.
3679 - CONFIG_ENV_MAX_ENTRIES
3681 Maximum number of entries in the hash table that is used
3682 internally to store the environment settings. The default
3683 setting is supposed to be generous and should work in most
3684 cases. This setting can be used to tune behaviour; see
3685 lib/hashtable.c for details.
3687 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3688 - CONFIG_ENV_FLAGS_LIST_STATIC
3689 Enable validation of the values given to environment variables when
3690 calling env set. Variables can be restricted to only decimal,
3691 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3692 the variables can also be restricted to IP address or MAC address.
3694 The format of the list is:
3695 type_attribute = [s|d|x|b|i|m]
3696 access_atribute = [a|r|o|c]
3697 attributes = type_attribute[access_atribute]
3698 entry = variable_name[:attributes]
3701 The type attributes are:
3702 s - String (default)
3705 b - Boolean ([1yYtT|0nNfF])
3709 The access attributes are:
3715 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3716 Define this to a list (string) to define the ".flags"
3717 envirnoment variable in the default or embedded environment.
3719 - CONFIG_ENV_FLAGS_LIST_STATIC
3720 Define this to a list (string) to define validation that
3721 should be done if an entry is not found in the ".flags"
3722 environment variable. To override a setting in the static
3723 list, simply add an entry for the same variable name to the
3726 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3727 If defined, don't allow the -f switch to env set override variable
3730 - CONFIG_SYS_GENERIC_BOARD
3731 This selects the architecture-generic board system instead of the
3732 architecture-specific board files. It is intended to move boards
3733 to this new framework over time. Defining this will disable the
3734 arch/foo/lib/board.c file and use common/board_f.c and
3735 common/board_r.c instead. To use this option your architecture
3736 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3737 its config.mk file). If you find problems enabling this option on
3738 your board please report the problem and send patches!
3740 - CONFIG_SYS_SYM_OFFSETS
3741 This is set by architectures that use offsets for link symbols
3742 instead of absolute values. So bss_start is obtained using an
3743 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3744 directly. You should not need to touch this setting.
3746 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3747 This is set by OMAP boards for the max time that reset should
3748 be asserted. See doc/README.omap-reset-time for details on how
3749 the value can be calulated on a given board.
3751 The following definitions that deal with the placement and management
3752 of environment data (variable area); in general, we support the
3753 following configurations:
3755 - CONFIG_BUILD_ENVCRC:
3757 Builds up envcrc with the target environment so that external utils
3758 may easily extract it and embed it in final U-Boot images.
3760 - CONFIG_ENV_IS_IN_FLASH:
3762 Define this if the environment is in flash memory.
3764 a) The environment occupies one whole flash sector, which is
3765 "embedded" in the text segment with the U-Boot code. This
3766 happens usually with "bottom boot sector" or "top boot
3767 sector" type flash chips, which have several smaller
3768 sectors at the start or the end. For instance, such a
3769 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3770 such a case you would place the environment in one of the
3771 4 kB sectors - with U-Boot code before and after it. With
3772 "top boot sector" type flash chips, you would put the
3773 environment in one of the last sectors, leaving a gap
3774 between U-Boot and the environment.
3776 - CONFIG_ENV_OFFSET:
3778 Offset of environment data (variable area) to the
3779 beginning of flash memory; for instance, with bottom boot
3780 type flash chips the second sector can be used: the offset
3781 for this sector is given here.
3783 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3787 This is just another way to specify the start address of
3788 the flash sector containing the environment (instead of
3791 - CONFIG_ENV_SECT_SIZE:
3793 Size of the sector containing the environment.
3796 b) Sometimes flash chips have few, equal sized, BIG sectors.
3797 In such a case you don't want to spend a whole sector for
3802 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3803 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3804 of this flash sector for the environment. This saves
3805 memory for the RAM copy of the environment.
3807 It may also save flash memory if you decide to use this
3808 when your environment is "embedded" within U-Boot code,
3809 since then the remainder of the flash sector could be used
3810 for U-Boot code. It should be pointed out that this is
3811 STRONGLY DISCOURAGED from a robustness point of view:
3812 updating the environment in flash makes it always
3813 necessary to erase the WHOLE sector. If something goes
3814 wrong before the contents has been restored from a copy in
3815 RAM, your target system will be dead.
3817 - CONFIG_ENV_ADDR_REDUND
3818 CONFIG_ENV_SIZE_REDUND
3820 These settings describe a second storage area used to hold
3821 a redundant copy of the environment data, so that there is
3822 a valid backup copy in case there is a power failure during
3823 a "saveenv" operation.
3825 BE CAREFUL! Any changes to the flash layout, and some changes to the
3826 source code will make it necessary to adapt <board>/u-boot.lds*
3830 - CONFIG_ENV_IS_IN_NVRAM:
3832 Define this if you have some non-volatile memory device
3833 (NVRAM, battery buffered SRAM) which you want to use for the
3839 These two #defines are used to determine the memory area you
3840 want to use for environment. It is assumed that this memory
3841 can just be read and written to, without any special
3844 BE CAREFUL! The first access to the environment happens quite early
3845 in U-Boot initalization (when we try to get the setting of for the
3846 console baudrate). You *MUST* have mapped your NVRAM area then, or
3849 Please note that even with NVRAM we still use a copy of the
3850 environment in RAM: we could work on NVRAM directly, but we want to
3851 keep settings there always unmodified except somebody uses "saveenv"
3852 to save the current settings.
3855 - CONFIG_ENV_IS_IN_EEPROM:
3857 Use this if you have an EEPROM or similar serial access
3858 device and a driver for it.
3860 - CONFIG_ENV_OFFSET:
3863 These two #defines specify the offset and size of the
3864 environment area within the total memory of your EEPROM.
3866 - CONFIG_SYS_I2C_EEPROM_ADDR:
3867 If defined, specified the chip address of the EEPROM device.
3868 The default address is zero.
3870 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3871 If defined, the number of bits used to address bytes in a
3872 single page in the EEPROM device. A 64 byte page, for example
3873 would require six bits.
3875 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3876 If defined, the number of milliseconds to delay between
3877 page writes. The default is zero milliseconds.
3879 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3880 The length in bytes of the EEPROM memory array address. Note
3881 that this is NOT the chip address length!
3883 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3884 EEPROM chips that implement "address overflow" are ones
3885 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3886 address and the extra bits end up in the "chip address" bit
3887 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3890 Note that we consider the length of the address field to
3891 still be one byte because the extra address bits are hidden
3892 in the chip address.
3894 - CONFIG_SYS_EEPROM_SIZE:
3895 The size in bytes of the EEPROM device.
3897 - CONFIG_ENV_EEPROM_IS_ON_I2C
3898 define this, if you have I2C and SPI activated, and your
3899 EEPROM, which holds the environment, is on the I2C bus.
3901 - CONFIG_I2C_ENV_EEPROM_BUS
3902 if you have an Environment on an EEPROM reached over
3903 I2C muxes, you can define here, how to reach this
3904 EEPROM. For example:
3906 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3908 EEPROM which holds the environment, is reached over
3909 a pca9547 i2c mux with address 0x70, channel 3.
3911 - CONFIG_ENV_IS_IN_DATAFLASH:
3913 Define this if you have a DataFlash memory device which you
3914 want to use for the environment.
3916 - CONFIG_ENV_OFFSET:
3920 These three #defines specify the offset and size of the
3921 environment area within the total memory of your DataFlash placed
3922 at the specified address.
3924 - CONFIG_ENV_IS_IN_REMOTE:
3926 Define this if you have a remote memory space which you
3927 want to use for the local device's environment.
3932 These two #defines specify the address and size of the
3933 environment area within the remote memory space. The
3934 local device can get the environment from remote memory
3935 space by SRIO or PCIE links.
3937 BE CAREFUL! For some special cases, the local device can not use
3938 "saveenv" command. For example, the local device will get the
3939 environment stored in a remote NOR flash by SRIO or PCIE link,
3940 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3942 - CONFIG_ENV_IS_IN_NAND:
3944 Define this if you have a NAND device which you want to use
3945 for the environment.
3947 - CONFIG_ENV_OFFSET:
3950 These two #defines specify the offset and size of the environment
3951 area within the first NAND device. CONFIG_ENV_OFFSET must be
3952 aligned to an erase block boundary.
3954 - CONFIG_ENV_OFFSET_REDUND (optional):
3956 This setting describes a second storage area of CONFIG_ENV_SIZE
3957 size used to hold a redundant copy of the environment data, so
3958 that there is a valid backup copy in case there is a power failure
3959 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3960 aligned to an erase block boundary.
3962 - CONFIG_ENV_RANGE (optional):
3964 Specifies the length of the region in which the environment
3965 can be written. This should be a multiple of the NAND device's
3966 block size. Specifying a range with more erase blocks than
3967 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3968 the range to be avoided.
3970 - CONFIG_ENV_OFFSET_OOB (optional):
3972 Enables support for dynamically retrieving the offset of the
3973 environment from block zero's out-of-band data. The
3974 "nand env.oob" command can be used to record this offset.
3975 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3976 using CONFIG_ENV_OFFSET_OOB.
3978 - CONFIG_NAND_ENV_DST
3980 Defines address in RAM to which the nand_spl code should copy the
3981 environment. If redundant environment is used, it will be copied to
3982 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3984 - CONFIG_ENV_IS_IN_UBI:
3986 Define this if you have an UBI volume that you want to use for the
3987 environment. This has the benefit of wear-leveling the environment
3988 accesses, which is important on NAND.
3990 - CONFIG_ENV_UBI_PART:
3992 Define this to a string that is the mtd partition containing the UBI.
3994 - CONFIG_ENV_UBI_VOLUME:
3996 Define this to the name of the volume that you want to store the
3999 - CONFIG_ENV_UBI_VOLUME_REDUND:
4001 Define this to the name of another volume to store a second copy of
4002 the environment in. This will enable redundant environments in UBI.
4003 It is assumed that both volumes are in the same MTD partition.
4005 - CONFIG_UBI_SILENCE_MSG
4006 - CONFIG_UBIFS_SILENCE_MSG
4008 You will probably want to define these to avoid a really noisy system
4009 when storing the env in UBI.
4011 - CONFIG_ENV_IS_IN_MMC:
4013 Define this if you have an MMC device which you want to use for the
4016 - CONFIG_SYS_MMC_ENV_DEV:
4018 Specifies which MMC device the environment is stored in.
4020 - CONFIG_SYS_MMC_ENV_PART (optional):
4022 Specifies which MMC partition the environment is stored in. If not
4023 set, defaults to partition 0, the user area. Common values might be
4024 1 (first MMC boot partition), 2 (second MMC boot partition).
4026 - CONFIG_ENV_OFFSET:
4029 These two #defines specify the offset and size of the environment
4030 area within the specified MMC device.
4032 If offset is positive (the usual case), it is treated as relative to
4033 the start of the MMC partition. If offset is negative, it is treated
4034 as relative to the end of the MMC partition. This can be useful if
4035 your board may be fitted with different MMC devices, which have
4036 different sizes for the MMC partitions, and you always want the
4037 environment placed at the very end of the partition, to leave the
4038 maximum possible space before it, to store other data.
4040 These two values are in units of bytes, but must be aligned to an
4041 MMC sector boundary.
4043 - CONFIG_ENV_OFFSET_REDUND (optional):
4045 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4046 hold a redundant copy of the environment data. This provides a
4047 valid backup copy in case the other copy is corrupted, e.g. due
4048 to a power failure during a "saveenv" operation.
4050 This value may also be positive or negative; this is handled in the
4051 same way as CONFIG_ENV_OFFSET.
4053 This value is also in units of bytes, but must also be aligned to
4054 an MMC sector boundary.
4056 - CONFIG_ENV_SIZE_REDUND (optional):
4058 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4059 set. If this value is set, it must be set to the same value as
4062 - CONFIG_SYS_SPI_INIT_OFFSET
4064 Defines offset to the initial SPI buffer area in DPRAM. The
4065 area is used at an early stage (ROM part) if the environment
4066 is configured to reside in the SPI EEPROM: We need a 520 byte
4067 scratch DPRAM area. It is used between the two initialization
4068 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4069 to be a good choice since it makes it far enough from the
4070 start of the data area as well as from the stack pointer.
4072 Please note that the environment is read-only until the monitor
4073 has been relocated to RAM and a RAM copy of the environment has been
4074 created; also, when using EEPROM you will have to use getenv_f()
4075 until then to read environment variables.
4077 The environment is protected by a CRC32 checksum. Before the monitor
4078 is relocated into RAM, as a result of a bad CRC you will be working
4079 with the compiled-in default environment - *silently*!!! [This is
4080 necessary, because the first environment variable we need is the
4081 "baudrate" setting for the console - if we have a bad CRC, we don't
4082 have any device yet where we could complain.]
4084 Note: once the monitor has been relocated, then it will complain if
4085 the default environment is used; a new CRC is computed as soon as you
4086 use the "saveenv" command to store a valid environment.
4088 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4089 Echo the inverted Ethernet link state to the fault LED.
4091 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4092 also needs to be defined.
4094 - CONFIG_SYS_FAULT_MII_ADDR:
4095 MII address of the PHY to check for the Ethernet link state.
4097 - CONFIG_NS16550_MIN_FUNCTIONS:
4098 Define this if you desire to only have use of the NS16550_init
4099 and NS16550_putc functions for the serial driver located at
4100 drivers/serial/ns16550.c. This option is useful for saving
4101 space for already greatly restricted images, including but not
4102 limited to NAND_SPL configurations.
4104 - CONFIG_DISPLAY_BOARDINFO
4105 Display information about the board that U-Boot is running on
4106 when U-Boot starts up. The board function checkboard() is called
4109 - CONFIG_DISPLAY_BOARDINFO_LATE
4110 Similar to the previous option, but display this information
4111 later, once stdio is running and output goes to the LCD, if
4114 Low Level (hardware related) configuration options:
4115 ---------------------------------------------------
4117 - CONFIG_SYS_CACHELINE_SIZE:
4118 Cache Line Size of the CPU.
4120 - CONFIG_SYS_DEFAULT_IMMR:
4121 Default address of the IMMR after system reset.
4123 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4124 and RPXsuper) to be able to adjust the position of
4125 the IMMR register after a reset.
4127 - CONFIG_SYS_CCSRBAR_DEFAULT:
4128 Default (power-on reset) physical address of CCSR on Freescale
4131 - CONFIG_SYS_CCSRBAR:
4132 Virtual address of CCSR. On a 32-bit build, this is typically
4133 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4135 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4136 for cross-platform code that uses that macro instead.
4138 - CONFIG_SYS_CCSRBAR_PHYS:
4139 Physical address of CCSR. CCSR can be relocated to a new
4140 physical address, if desired. In this case, this macro should
4141 be set to that address. Otherwise, it should be set to the
4142 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4143 is typically relocated on 36-bit builds. It is recommended
4144 that this macro be defined via the _HIGH and _LOW macros:
4146 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4147 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4149 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4150 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4151 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4152 used in assembly code, so it must not contain typecasts or
4153 integer size suffixes (e.g. "ULL").
4155 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4156 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4157 used in assembly code, so it must not contain typecasts or
4158 integer size suffixes (e.g. "ULL").
4160 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4161 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4162 forced to a value that ensures that CCSR is not relocated.
4164 - Floppy Disk Support:
4165 CONFIG_SYS_FDC_DRIVE_NUMBER
4167 the default drive number (default value 0)
4169 CONFIG_SYS_ISA_IO_STRIDE
4171 defines the spacing between FDC chipset registers
4174 CONFIG_SYS_ISA_IO_OFFSET
4176 defines the offset of register from address. It
4177 depends on which part of the data bus is connected to
4178 the FDC chipset. (default value 0)
4180 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4181 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4184 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4185 fdc_hw_init() is called at the beginning of the FDC
4186 setup. fdc_hw_init() must be provided by the board
4187 source code. It is used to make hardware dependant
4191 Most IDE controllers were designed to be connected with PCI
4192 interface. Only few of them were designed for AHB interface.
4193 When software is doing ATA command and data transfer to
4194 IDE devices through IDE-AHB controller, some additional
4195 registers accessing to these kind of IDE-AHB controller
4198 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4199 DO NOT CHANGE unless you know exactly what you're
4200 doing! (11-4) [MPC8xx/82xx systems only]
4202 - CONFIG_SYS_INIT_RAM_ADDR:
4204 Start address of memory area that can be used for
4205 initial data and stack; please note that this must be
4206 writable memory that is working WITHOUT special
4207 initialization, i. e. you CANNOT use normal RAM which
4208 will become available only after programming the
4209 memory controller and running certain initialization
4212 U-Boot uses the following memory types:
4213 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4214 - MPC824X: data cache
4215 - PPC4xx: data cache
4217 - CONFIG_SYS_GBL_DATA_OFFSET:
4219 Offset of the initial data structure in the memory
4220 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4221 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4222 data is located at the end of the available space
4223 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4224 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4225 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4226 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4229 On the MPC824X (or other systems that use the data
4230 cache for initial memory) the address chosen for
4231 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4232 point to an otherwise UNUSED address space between
4233 the top of RAM and the start of the PCI space.
4235 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4237 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4239 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4241 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4243 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4245 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4247 - CONFIG_SYS_OR_TIMING_SDRAM:
4250 - CONFIG_SYS_MAMR_PTA:
4251 periodic timer for refresh
4253 - CONFIG_SYS_DER: Debug Event Register (37-47)
4255 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4256 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4257 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4258 CONFIG_SYS_BR1_PRELIM:
4259 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4261 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4262 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4263 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4264 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4266 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4267 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4268 Machine Mode Register and Memory Periodic Timer
4269 Prescaler definitions (SDRAM timing)
4271 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4272 enable I2C microcode relocation patch (MPC8xx);
4273 define relocation offset in DPRAM [DSP2]
4275 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4276 enable SMC microcode relocation patch (MPC8xx);
4277 define relocation offset in DPRAM [SMC1]
4279 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4280 enable SPI microcode relocation patch (MPC8xx);
4281 define relocation offset in DPRAM [SCC4]
4283 - CONFIG_SYS_USE_OSCCLK:
4284 Use OSCM clock mode on MBX8xx board. Be careful,
4285 wrong setting might damage your board. Read
4286 doc/README.MBX before setting this variable!
4288 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4289 Offset of the bootmode word in DPRAM used by post
4290 (Power On Self Tests). This definition overrides
4291 #define'd default value in commproc.h resp.
4294 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4295 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4296 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4297 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4298 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4299 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4300 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4301 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4302 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4304 - CONFIG_PCI_DISABLE_PCIE:
4305 Disable PCI-Express on systems where it is supported but not
4308 - CONFIG_PCI_ENUM_ONLY
4309 Only scan through and get the devices on the busses.
4310 Don't do any setup work, presumably because someone or
4311 something has already done it, and we don't need to do it
4312 a second time. Useful for platforms that are pre-booted
4313 by coreboot or similar.
4315 - CONFIG_PCI_INDIRECT_BRIDGE:
4316 Enable support for indirect PCI bridges.
4319 Chip has SRIO or not
4322 Board has SRIO 1 port available
4325 Board has SRIO 2 port available
4327 - CONFIG_SRIO_PCIE_BOOT_MASTER
4328 Board can support master function for Boot from SRIO and PCIE
4330 - CONFIG_SYS_SRIOn_MEM_VIRT:
4331 Virtual Address of SRIO port 'n' memory region
4333 - CONFIG_SYS_SRIOn_MEM_PHYS:
4334 Physical Address of SRIO port 'n' memory region
4336 - CONFIG_SYS_SRIOn_MEM_SIZE:
4337 Size of SRIO port 'n' memory region
4339 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4340 Defined to tell the NAND controller that the NAND chip is using
4342 Not all NAND drivers use this symbol.
4343 Example of drivers that use it:
4344 - drivers/mtd/nand/ndfc.c
4345 - drivers/mtd/nand/mxc_nand.c
4347 - CONFIG_SYS_NDFC_EBC0_CFG
4348 Sets the EBC0_CFG register for the NDFC. If not defined
4349 a default value will be used.
4352 Get DDR timing information from an I2C EEPROM. Common
4353 with pluggable memory modules such as SODIMMs
4356 I2C address of the SPD EEPROM
4358 - CONFIG_SYS_SPD_BUS_NUM
4359 If SPD EEPROM is on an I2C bus other than the first
4360 one, specify here. Note that the value must resolve
4361 to something your driver can deal with.
4363 - CONFIG_SYS_DDR_RAW_TIMING
4364 Get DDR timing information from other than SPD. Common with
4365 soldered DDR chips onboard without SPD. DDR raw timing
4366 parameters are extracted from datasheet and hard-coded into
4367 header files or board specific files.
4369 - CONFIG_FSL_DDR_INTERACTIVE
4370 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4372 - CONFIG_SYS_83XX_DDR_USES_CS0
4373 Only for 83xx systems. If specified, then DDR should
4374 be configured using CS0 and CS1 instead of CS2 and CS3.
4376 - CONFIG_ETHER_ON_FEC[12]
4377 Define to enable FEC[12] on a 8xx series processor.
4379 - CONFIG_FEC[12]_PHY
4380 Define to the hardcoded PHY address which corresponds
4381 to the given FEC; i. e.
4382 #define CONFIG_FEC1_PHY 4
4383 means that the PHY with address 4 is connected to FEC1
4385 When set to -1, means to probe for first available.
4387 - CONFIG_FEC[12]_PHY_NORXERR
4388 The PHY does not have a RXERR line (RMII only).
4389 (so program the FEC to ignore it).
4392 Enable RMII mode for all FECs.
4393 Note that this is a global option, we can't
4394 have one FEC in standard MII mode and another in RMII mode.
4396 - CONFIG_CRC32_VERIFY
4397 Add a verify option to the crc32 command.
4400 => crc32 -v <address> <count> <crc32>
4402 Where address/count indicate a memory area
4403 and crc32 is the correct crc32 which the
4407 Add the "loopw" memory command. This only takes effect if
4408 the memory commands are activated globally (CONFIG_CMD_MEM).
4411 Add the "mdc" and "mwc" memory commands. These are cyclic
4416 This command will print 4 bytes (10,11,12,13) each 500 ms.
4418 => mwc.l 100 12345678 10
4419 This command will write 12345678 to address 100 all 10 ms.
4421 This only takes effect if the memory commands are activated
4422 globally (CONFIG_CMD_MEM).
4424 - CONFIG_SKIP_LOWLEVEL_INIT
4425 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4426 low level initializations (like setting up the memory
4427 controller) are omitted and/or U-Boot does not
4428 relocate itself into RAM.
4430 Normally this variable MUST NOT be defined. The only
4431 exception is when U-Boot is loaded (to RAM) by some
4432 other boot loader or by a debugger which performs
4433 these initializations itself.
4436 Modifies the behaviour of start.S when compiling a loader
4437 that is executed before the actual U-Boot. E.g. when
4438 compiling a NAND SPL.
4441 Modifies the behaviour of start.S when compiling a loader
4442 that is executed after the SPL and before the actual U-Boot.
4443 It is loaded by the SPL.
4445 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4446 Only for 85xx systems. If this variable is specified, the section
4447 .resetvec is not kept and the section .bootpg is placed in the
4448 previous 4k of the .text section.
4450 - CONFIG_ARCH_MAP_SYSMEM
4451 Generally U-Boot (and in particular the md command) uses
4452 effective address. It is therefore not necessary to regard
4453 U-Boot address as virtual addresses that need to be translated
4454 to physical addresses. However, sandbox requires this, since
4455 it maintains its own little RAM buffer which contains all
4456 addressable memory. This option causes some memory accesses
4457 to be mapped through map_sysmem() / unmap_sysmem().
4459 - CONFIG_USE_ARCH_MEMCPY
4460 CONFIG_USE_ARCH_MEMSET
4461 If these options are used a optimized version of memcpy/memset will
4462 be used if available. These functions may be faster under some
4463 conditions but may increase the binary size.
4465 - CONFIG_X86_RESET_VECTOR
4466 If defined, the x86 reset vector code is included. This is not
4467 needed when U-Boot is running from Coreboot.
4470 Defines the MPU clock speed (in MHz).
4472 NOTE : currently only supported on AM335x platforms.
4474 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4475 Enables the RTC32K OSC on AM33xx based plattforms
4477 Freescale QE/FMAN Firmware Support:
4478 -----------------------------------
4480 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4481 loading of "firmware", which is encoded in the QE firmware binary format.
4482 This firmware often needs to be loaded during U-Boot booting, so macros
4483 are used to identify the storage device (NOR flash, SPI, etc) and the address
4486 - CONFIG_SYS_QE_FMAN_FW_ADDR
4487 The address in the storage device where the firmware is located. The
4488 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4491 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4492 The maximum possible size of the firmware. The firmware binary format
4493 has a field that specifies the actual size of the firmware, but it
4494 might not be possible to read any part of the firmware unless some
4495 local storage is allocated to hold the entire firmware first.
4497 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4498 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4499 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4500 virtual address in NOR flash.
4502 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4503 Specifies that QE/FMAN firmware is located in NAND flash.
4504 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4506 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4507 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4508 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4510 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4511 Specifies that QE/FMAN firmware is located on the primary SPI
4512 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4514 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4515 Specifies that QE/FMAN firmware is located in the remote (master)
4516 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4517 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4518 window->master inbound window->master LAW->the ucode address in
4519 master's memory space.
4521 Building the Software:
4522 ======================
4524 Building U-Boot has been tested in several native build environments
4525 and in many different cross environments. Of course we cannot support
4526 all possibly existing versions of cross development tools in all
4527 (potentially obsolete) versions. In case of tool chain problems we
4528 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4529 which is extensively used to build and test U-Boot.
4531 If you are not using a native environment, it is assumed that you
4532 have GNU cross compiling tools available in your path. In this case,
4533 you must set the environment variable CROSS_COMPILE in your shell.
4534 Note that no changes to the Makefile or any other source files are
4535 necessary. For example using the ELDK on a 4xx CPU, please enter:
4537 $ CROSS_COMPILE=ppc_4xx-
4538 $ export CROSS_COMPILE
4540 Note: If you wish to generate Windows versions of the utilities in
4541 the tools directory you can use the MinGW toolchain
4542 (http://www.mingw.org). Set your HOST tools to the MinGW
4543 toolchain and execute 'make tools'. For example:
4545 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4547 Binaries such as tools/mkimage.exe will be created which can
4548 be executed on computers running Windows.
4550 U-Boot is intended to be simple to build. After installing the
4551 sources you must configure U-Boot for one specific board type. This
4556 where "NAME_config" is the name of one of the existing configu-
4557 rations; see boards.cfg for supported names.
4559 Note: for some board special configuration names may exist; check if
4560 additional information is available from the board vendor; for
4561 instance, the TQM823L systems are available without (standard)
4562 or with LCD support. You can select such additional "features"
4563 when choosing the configuration, i. e.
4566 - will configure for a plain TQM823L, i. e. no LCD support
4568 make TQM823L_LCD_config
4569 - will configure for a TQM823L with U-Boot console on LCD
4574 Finally, type "make all", and you should get some working U-Boot
4575 images ready for download to / installation on your system:
4577 - "u-boot.bin" is a raw binary image
4578 - "u-boot" is an image in ELF binary format
4579 - "u-boot.srec" is in Motorola S-Record format
4581 By default the build is performed locally and the objects are saved
4582 in the source directory. One of the two methods can be used to change
4583 this behavior and build U-Boot to some external directory:
4585 1. Add O= to the make command line invocations:
4587 make O=/tmp/build distclean
4588 make O=/tmp/build NAME_config
4589 make O=/tmp/build all
4591 2. Set environment variable BUILD_DIR to point to the desired location:
4593 export BUILD_DIR=/tmp/build
4598 Note that the command line "O=" setting overrides the BUILD_DIR environment
4602 Please be aware that the Makefiles assume you are using GNU make, so
4603 for instance on NetBSD you might need to use "gmake" instead of
4607 If the system board that you have is not listed, then you will need
4608 to port U-Boot to your hardware platform. To do this, follow these
4611 1. Add a new configuration option for your board to the toplevel
4612 "boards.cfg" file, using the existing entries as examples.
4613 Follow the instructions there to keep the boards in order.
4614 2. Create a new directory to hold your board specific code. Add any
4615 files you need. In your board directory, you will need at least
4616 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4617 3. Create a new configuration file "include/configs/<board>.h" for
4619 3. If you're porting U-Boot to a new CPU, then also create a new
4620 directory to hold your CPU specific code. Add any files you need.
4621 4. Run "make <board>_config" with your new name.
4622 5. Type "make", and you should get a working "u-boot.srec" file
4623 to be installed on your target system.
4624 6. Debug and solve any problems that might arise.
4625 [Of course, this last step is much harder than it sounds.]
4628 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4629 ==============================================================
4631 If you have modified U-Boot sources (for instance added a new board
4632 or support for new devices, a new CPU, etc.) you are expected to
4633 provide feedback to the other developers. The feedback normally takes
4634 the form of a "patch", i. e. a context diff against a certain (latest
4635 official or latest in the git repository) version of U-Boot sources.
4637 But before you submit such a patch, please verify that your modifi-
4638 cation did not break existing code. At least make sure that *ALL* of
4639 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4640 just run the "MAKEALL" script, which will configure and build U-Boot
4641 for ALL supported system. Be warned, this will take a while. You can
4642 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4643 environment variable to the script, i. e. to use the ELDK cross tools
4646 CROSS_COMPILE=ppc_8xx- MAKEALL
4648 or to build on a native PowerPC system you can type
4650 CROSS_COMPILE=' ' MAKEALL
4652 When using the MAKEALL script, the default behaviour is to build
4653 U-Boot in the source directory. This location can be changed by
4654 setting the BUILD_DIR environment variable. Also, for each target
4655 built, the MAKEALL script saves two log files (<target>.ERR and
4656 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4657 location can be changed by setting the MAKEALL_LOGDIR environment
4658 variable. For example:
4660 export BUILD_DIR=/tmp/build
4661 export MAKEALL_LOGDIR=/tmp/log
4662 CROSS_COMPILE=ppc_8xx- MAKEALL
4664 With the above settings build objects are saved in the /tmp/build,
4665 log files are saved in the /tmp/log and the source tree remains clean
4666 during the whole build process.
4669 See also "U-Boot Porting Guide" below.
4672 Monitor Commands - Overview:
4673 ============================
4675 go - start application at address 'addr'
4676 run - run commands in an environment variable
4677 bootm - boot application image from memory
4678 bootp - boot image via network using BootP/TFTP protocol
4679 bootz - boot zImage from memory
4680 tftpboot- boot image via network using TFTP protocol
4681 and env variables "ipaddr" and "serverip"
4682 (and eventually "gatewayip")
4683 tftpput - upload a file via network using TFTP protocol
4684 rarpboot- boot image via network using RARP/TFTP protocol
4685 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4686 loads - load S-Record file over serial line
4687 loadb - load binary file over serial line (kermit mode)
4689 mm - memory modify (auto-incrementing)
4690 nm - memory modify (constant address)
4691 mw - memory write (fill)
4693 cmp - memory compare
4694 crc32 - checksum calculation
4695 i2c - I2C sub-system
4696 sspi - SPI utility commands
4697 base - print or set address offset
4698 printenv- print environment variables
4699 setenv - set environment variables
4700 saveenv - save environment variables to persistent storage
4701 protect - enable or disable FLASH write protection
4702 erase - erase FLASH memory
4703 flinfo - print FLASH memory information
4704 nand - NAND memory operations (see doc/README.nand)
4705 bdinfo - print Board Info structure
4706 iminfo - print header information for application image
4707 coninfo - print console devices and informations
4708 ide - IDE sub-system
4709 loop - infinite loop on address range
4710 loopw - infinite write loop on address range
4711 mtest - simple RAM test
4712 icache - enable or disable instruction cache
4713 dcache - enable or disable data cache
4714 reset - Perform RESET of the CPU
4715 echo - echo args to console
4716 version - print monitor version
4717 help - print online help
4718 ? - alias for 'help'
4721 Monitor Commands - Detailed Description:
4722 ========================================
4726 For now: just type "help <command>".
4729 Environment Variables:
4730 ======================
4732 U-Boot supports user configuration using Environment Variables which
4733 can be made persistent by saving to Flash memory.
4735 Environment Variables are set using "setenv", printed using
4736 "printenv", and saved to Flash using "saveenv". Using "setenv"
4737 without a value can be used to delete a variable from the
4738 environment. As long as you don't save the environment you are
4739 working with an in-memory copy. In case the Flash area containing the
4740 environment is erased by accident, a default environment is provided.
4742 Some configuration options can be set using Environment Variables.
4744 List of environment variables (most likely not complete):
4746 baudrate - see CONFIG_BAUDRATE
4748 bootdelay - see CONFIG_BOOTDELAY
4750 bootcmd - see CONFIG_BOOTCOMMAND
4752 bootargs - Boot arguments when booting an RTOS image
4754 bootfile - Name of the image to load with TFTP
4756 bootm_low - Memory range available for image processing in the bootm
4757 command can be restricted. This variable is given as
4758 a hexadecimal number and defines lowest address allowed
4759 for use by the bootm command. See also "bootm_size"
4760 environment variable. Address defined by "bootm_low" is
4761 also the base of the initial memory mapping for the Linux
4762 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4765 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4766 This variable is given as a hexadecimal number and it
4767 defines the size of the memory region starting at base
4768 address bootm_low that is accessible by the Linux kernel
4769 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4770 as the default value if it is defined, and bootm_size is
4773 bootm_size - Memory range available for image processing in the bootm
4774 command can be restricted. This variable is given as
4775 a hexadecimal number and defines the size of the region
4776 allowed for use by the bootm command. See also "bootm_low"
4777 environment variable.
4779 updatefile - Location of the software update file on a TFTP server, used
4780 by the automatic software update feature. Please refer to
4781 documentation in doc/README.update for more details.
4783 autoload - if set to "no" (any string beginning with 'n'),
4784 "bootp" will just load perform a lookup of the
4785 configuration from the BOOTP server, but not try to
4786 load any image using TFTP
4788 autostart - if set to "yes", an image loaded using the "bootp",
4789 "rarpboot", "tftpboot" or "diskboot" commands will
4790 be automatically started (by internally calling
4793 If set to "no", a standalone image passed to the
4794 "bootm" command will be copied to the load address
4795 (and eventually uncompressed), but NOT be started.
4796 This can be used to load and uncompress arbitrary
4799 fdt_high - if set this restricts the maximum address that the
4800 flattened device tree will be copied into upon boot.
4801 For example, if you have a system with 1 GB memory
4802 at physical address 0x10000000, while Linux kernel
4803 only recognizes the first 704 MB as low memory, you
4804 may need to set fdt_high as 0x3C000000 to have the
4805 device tree blob be copied to the maximum address
4806 of the 704 MB low memory, so that Linux kernel can
4807 access it during the boot procedure.
4809 If this is set to the special value 0xFFFFFFFF then
4810 the fdt will not be copied at all on boot. For this
4811 to work it must reside in writable memory, have
4812 sufficient padding on the end of it for u-boot to
4813 add the information it needs into it, and the memory
4814 must be accessible by the kernel.
4816 fdtcontroladdr- if set this is the address of the control flattened
4817 device tree used by U-Boot when CONFIG_OF_CONTROL is
4820 i2cfast - (PPC405GP|PPC405EP only)
4821 if set to 'y' configures Linux I2C driver for fast
4822 mode (400kHZ). This environment variable is used in
4823 initialization code. So, for changes to be effective
4824 it must be saved and board must be reset.
4826 initrd_high - restrict positioning of initrd images:
4827 If this variable is not set, initrd images will be
4828 copied to the highest possible address in RAM; this
4829 is usually what you want since it allows for
4830 maximum initrd size. If for some reason you want to
4831 make sure that the initrd image is loaded below the
4832 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4833 variable to a value of "no" or "off" or "0".
4834 Alternatively, you can set it to a maximum upper
4835 address to use (U-Boot will still check that it
4836 does not overwrite the U-Boot stack and data).
4838 For instance, when you have a system with 16 MB
4839 RAM, and want to reserve 4 MB from use by Linux,
4840 you can do this by adding "mem=12M" to the value of
4841 the "bootargs" variable. However, now you must make
4842 sure that the initrd image is placed in the first
4843 12 MB as well - this can be done with
4845 setenv initrd_high 00c00000
4847 If you set initrd_high to 0xFFFFFFFF, this is an
4848 indication to U-Boot that all addresses are legal
4849 for the Linux kernel, including addresses in flash
4850 memory. In this case U-Boot will NOT COPY the
4851 ramdisk at all. This may be useful to reduce the
4852 boot time on your system, but requires that this
4853 feature is supported by your Linux kernel.
4855 ipaddr - IP address; needed for tftpboot command
4857 loadaddr - Default load address for commands like "bootp",
4858 "rarpboot", "tftpboot", "loadb" or "diskboot"
4860 loads_echo - see CONFIG_LOADS_ECHO
4862 serverip - TFTP server IP address; needed for tftpboot command
4864 bootretry - see CONFIG_BOOT_RETRY_TIME
4866 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4868 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4870 ethprime - controls which interface is used first.
4872 ethact - controls which interface is currently active.
4873 For example you can do the following
4875 => setenv ethact FEC
4876 => ping 192.168.0.1 # traffic sent on FEC
4877 => setenv ethact SCC
4878 => ping 10.0.0.1 # traffic sent on SCC
4880 ethrotate - When set to "no" U-Boot does not go through all
4881 available network interfaces.
4882 It just stays at the currently selected interface.
4884 netretry - When set to "no" each network operation will
4885 either succeed or fail without retrying.
4886 When set to "once" the network operation will
4887 fail when all the available network interfaces
4888 are tried once without success.
4889 Useful on scripts which control the retry operation
4892 npe_ucode - set load address for the NPE microcode
4894 silent_linux - If set then linux will be told to boot silently, by
4895 changing the console to be empty. If "yes" it will be
4896 made silent. If "no" it will not be made silent. If
4897 unset, then it will be made silent if the U-Boot console
4900 tftpsrcport - If this is set, the value is used for TFTP's
4903 tftpdstport - If this is set, the value is used for TFTP's UDP
4904 destination port instead of the Well Know Port 69.
4906 tftpblocksize - Block size to use for TFTP transfers; if not set,
4907 we use the TFTP server's default block size
4909 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4910 seconds, minimum value is 1000 = 1 second). Defines
4911 when a packet is considered to be lost so it has to
4912 be retransmitted. The default is 5000 = 5 seconds.
4913 Lowering this value may make downloads succeed
4914 faster in networks with high packet loss rates or
4915 with unreliable TFTP servers.
4917 vlan - When set to a value < 4095 the traffic over
4918 Ethernet is encapsulated/received over 802.1q
4921 The following image location variables contain the location of images
4922 used in booting. The "Image" column gives the role of the image and is
4923 not an environment variable name. The other columns are environment
4924 variable names. "File Name" gives the name of the file on a TFTP
4925 server, "RAM Address" gives the location in RAM the image will be
4926 loaded to, and "Flash Location" gives the image's address in NOR
4927 flash or offset in NAND flash.
4929 *Note* - these variables don't have to be defined for all boards, some
4930 boards currenlty use other variables for these purposes, and some
4931 boards use these variables for other purposes.
4933 Image File Name RAM Address Flash Location
4934 ----- --------- ----------- --------------
4935 u-boot u-boot u-boot_addr_r u-boot_addr
4936 Linux kernel bootfile kernel_addr_r kernel_addr
4937 device tree blob fdtfile fdt_addr_r fdt_addr
4938 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4940 The following environment variables may be used and automatically
4941 updated by the network boot commands ("bootp" and "rarpboot"),
4942 depending the information provided by your boot server:
4944 bootfile - see above
4945 dnsip - IP address of your Domain Name Server
4946 dnsip2 - IP address of your secondary Domain Name Server
4947 gatewayip - IP address of the Gateway (Router) to use
4948 hostname - Target hostname
4950 netmask - Subnet Mask
4951 rootpath - Pathname of the root filesystem on the NFS server
4952 serverip - see above
4955 There are two special Environment Variables:
4957 serial# - contains hardware identification information such
4958 as type string and/or serial number
4959 ethaddr - Ethernet address
4961 These variables can be set only once (usually during manufacturing of
4962 the board). U-Boot refuses to delete or overwrite these variables
4963 once they have been set once.
4966 Further special Environment Variables:
4968 ver - Contains the U-Boot version string as printed
4969 with the "version" command. This variable is
4970 readonly (see CONFIG_VERSION_VARIABLE).
4973 Please note that changes to some configuration parameters may take
4974 only effect after the next boot (yes, that's just like Windoze :-).
4977 Callback functions for environment variables:
4978 ---------------------------------------------
4980 For some environment variables, the behavior of u-boot needs to change
4981 when their values are changed. This functionailty allows functions to
4982 be associated with arbitrary variables. On creation, overwrite, or
4983 deletion, the callback will provide the opportunity for some side
4984 effect to happen or for the change to be rejected.
4986 The callbacks are named and associated with a function using the
4987 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4989 These callbacks are associated with variables in one of two ways. The
4990 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4991 in the board configuration to a string that defines a list of
4992 associations. The list must be in the following format:
4994 entry = variable_name[:callback_name]
4997 If the callback name is not specified, then the callback is deleted.
4998 Spaces are also allowed anywhere in the list.
5000 Callbacks can also be associated by defining the ".callbacks" variable
5001 with the same list format above. Any association in ".callbacks" will
5002 override any association in the static list. You can define
5003 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5004 ".callbacks" envirnoment variable in the default or embedded environment.
5007 Command Line Parsing:
5008 =====================
5010 There are two different command line parsers available with U-Boot:
5011 the old "simple" one, and the much more powerful "hush" shell:
5013 Old, simple command line parser:
5014 --------------------------------
5016 - supports environment variables (through setenv / saveenv commands)
5017 - several commands on one line, separated by ';'
5018 - variable substitution using "... ${name} ..." syntax
5019 - special characters ('$', ';') can be escaped by prefixing with '\',
5021 setenv bootcmd bootm \${address}
5022 - You can also escape text by enclosing in single apostrophes, for example:
5023 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5028 - similar to Bourne shell, with control structures like
5029 if...then...else...fi, for...do...done; while...do...done,
5030 until...do...done, ...
5031 - supports environment ("global") variables (through setenv / saveenv
5032 commands) and local shell variables (through standard shell syntax
5033 "name=value"); only environment variables can be used with "run"
5039 (1) If a command line (or an environment variable executed by a "run"
5040 command) contains several commands separated by semicolon, and
5041 one of these commands fails, then the remaining commands will be
5044 (2) If you execute several variables with one call to run (i. e.
5045 calling run with a list of variables as arguments), any failing
5046 command will cause "run" to terminate, i. e. the remaining
5047 variables are not executed.
5049 Note for Redundant Ethernet Interfaces:
5050 =======================================
5052 Some boards come with redundant Ethernet interfaces; U-Boot supports
5053 such configurations and is capable of automatic selection of a
5054 "working" interface when needed. MAC assignment works as follows:
5056 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5057 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5058 "eth1addr" (=>eth1), "eth2addr", ...
5060 If the network interface stores some valid MAC address (for instance
5061 in SROM), this is used as default address if there is NO correspon-
5062 ding setting in the environment; if the corresponding environment
5063 variable is set, this overrides the settings in the card; that means:
5065 o If the SROM has a valid MAC address, and there is no address in the
5066 environment, the SROM's address is used.
5068 o If there is no valid address in the SROM, and a definition in the
5069 environment exists, then the value from the environment variable is
5072 o If both the SROM and the environment contain a MAC address, and
5073 both addresses are the same, this MAC address is used.
5075 o If both the SROM and the environment contain a MAC address, and the
5076 addresses differ, the value from the environment is used and a
5079 o If neither SROM nor the environment contain a MAC address, an error
5082 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5083 will be programmed into hardware as part of the initialization process. This
5084 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5085 The naming convention is as follows:
5086 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5091 U-Boot is capable of booting (and performing other auxiliary operations on)
5092 images in two formats:
5094 New uImage format (FIT)
5095 -----------------------
5097 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5098 to Flattened Device Tree). It allows the use of images with multiple
5099 components (several kernels, ramdisks, etc.), with contents protected by
5100 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5106 Old image format is based on binary files which can be basically anything,
5107 preceded by a special header; see the definitions in include/image.h for
5108 details; basically, the header defines the following image properties:
5110 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5111 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5112 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5113 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5115 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5116 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5117 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5118 * Compression Type (uncompressed, gzip, bzip2)
5124 The header is marked by a special Magic Number, and both the header
5125 and the data portions of the image are secured against corruption by
5132 Although U-Boot should support any OS or standalone application
5133 easily, the main focus has always been on Linux during the design of
5136 U-Boot includes many features that so far have been part of some
5137 special "boot loader" code within the Linux kernel. Also, any
5138 "initrd" images to be used are no longer part of one big Linux image;
5139 instead, kernel and "initrd" are separate images. This implementation
5140 serves several purposes:
5142 - the same features can be used for other OS or standalone
5143 applications (for instance: using compressed images to reduce the
5144 Flash memory footprint)
5146 - it becomes much easier to port new Linux kernel versions because
5147 lots of low-level, hardware dependent stuff are done by U-Boot
5149 - the same Linux kernel image can now be used with different "initrd"
5150 images; of course this also means that different kernel images can
5151 be run with the same "initrd". This makes testing easier (you don't
5152 have to build a new "zImage.initrd" Linux image when you just
5153 change a file in your "initrd"). Also, a field-upgrade of the
5154 software is easier now.
5160 Porting Linux to U-Boot based systems:
5161 ---------------------------------------
5163 U-Boot cannot save you from doing all the necessary modifications to
5164 configure the Linux device drivers for use with your target hardware
5165 (no, we don't intend to provide a full virtual machine interface to
5168 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5170 Just make sure your machine specific header file (for instance
5171 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5172 Information structure as we define in include/asm-<arch>/u-boot.h,
5173 and make sure that your definition of IMAP_ADDR uses the same value
5174 as your U-Boot configuration in CONFIG_SYS_IMMR.
5177 Configuring the Linux kernel:
5178 -----------------------------
5180 No specific requirements for U-Boot. Make sure you have some root
5181 device (initial ramdisk, NFS) for your target system.
5184 Building a Linux Image:
5185 -----------------------
5187 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5188 not used. If you use recent kernel source, a new build target
5189 "uImage" will exist which automatically builds an image usable by
5190 U-Boot. Most older kernels also have support for a "pImage" target,
5191 which was introduced for our predecessor project PPCBoot and uses a
5192 100% compatible format.
5201 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5202 encapsulate a compressed Linux kernel image with header information,
5203 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5205 * build a standard "vmlinux" kernel image (in ELF binary format):
5207 * convert the kernel into a raw binary image:
5209 ${CROSS_COMPILE}-objcopy -O binary \
5210 -R .note -R .comment \
5211 -S vmlinux linux.bin
5213 * compress the binary image:
5217 * package compressed binary image for U-Boot:
5219 mkimage -A ppc -O linux -T kernel -C gzip \
5220 -a 0 -e 0 -n "Linux Kernel Image" \
5221 -d linux.bin.gz uImage
5224 The "mkimage" tool can also be used to create ramdisk images for use
5225 with U-Boot, either separated from the Linux kernel image, or
5226 combined into one file. "mkimage" encapsulates the images with a 64
5227 byte header containing information about target architecture,
5228 operating system, image type, compression method, entry points, time
5229 stamp, CRC32 checksums, etc.
5231 "mkimage" can be called in two ways: to verify existing images and
5232 print the header information, or to build new images.
5234 In the first form (with "-l" option) mkimage lists the information
5235 contained in the header of an existing U-Boot image; this includes
5236 checksum verification:
5238 tools/mkimage -l image
5239 -l ==> list image header information
5241 The second form (with "-d" option) is used to build a U-Boot image
5242 from a "data file" which is used as image payload:
5244 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5245 -n name -d data_file image
5246 -A ==> set architecture to 'arch'
5247 -O ==> set operating system to 'os'
5248 -T ==> set image type to 'type'
5249 -C ==> set compression type 'comp'
5250 -a ==> set load address to 'addr' (hex)
5251 -e ==> set entry point to 'ep' (hex)
5252 -n ==> set image name to 'name'
5253 -d ==> use image data from 'datafile'
5255 Right now, all Linux kernels for PowerPC systems use the same load
5256 address (0x00000000), but the entry point address depends on the
5259 - 2.2.x kernels have the entry point at 0x0000000C,
5260 - 2.3.x and later kernels have the entry point at 0x00000000.
5262 So a typical call to build a U-Boot image would read:
5264 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5265 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5266 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5267 > examples/uImage.TQM850L
5268 Image Name: 2.4.4 kernel for TQM850L
5269 Created: Wed Jul 19 02:34:59 2000
5270 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5271 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5272 Load Address: 0x00000000
5273 Entry Point: 0x00000000
5275 To verify the contents of the image (or check for corruption):
5277 -> tools/mkimage -l examples/uImage.TQM850L
5278 Image Name: 2.4.4 kernel for TQM850L
5279 Created: Wed Jul 19 02:34:59 2000
5280 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5281 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5282 Load Address: 0x00000000
5283 Entry Point: 0x00000000
5285 NOTE: for embedded systems where boot time is critical you can trade
5286 speed for memory and install an UNCOMPRESSED image instead: this
5287 needs more space in Flash, but boots much faster since it does not
5288 need to be uncompressed:
5290 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5291 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5292 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5293 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5294 > examples/uImage.TQM850L-uncompressed
5295 Image Name: 2.4.4 kernel for TQM850L
5296 Created: Wed Jul 19 02:34:59 2000
5297 Image Type: PowerPC Linux Kernel Image (uncompressed)
5298 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5299 Load Address: 0x00000000
5300 Entry Point: 0x00000000
5303 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5304 when your kernel is intended to use an initial ramdisk:
5306 -> tools/mkimage -n 'Simple Ramdisk Image' \
5307 > -A ppc -O linux -T ramdisk -C gzip \
5308 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5309 Image Name: Simple Ramdisk Image
5310 Created: Wed Jan 12 14:01:50 2000
5311 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5312 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5313 Load Address: 0x00000000
5314 Entry Point: 0x00000000
5316 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5317 option performs the converse operation of the mkimage's second form (the "-d"
5318 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5321 tools/dumpimage -i image -p position data_file
5322 -i ==> extract from the 'image' a specific 'data_file', \
5323 indexed by 'position'
5326 Installing a Linux Image:
5327 -------------------------
5329 To downloading a U-Boot image over the serial (console) interface,
5330 you must convert the image to S-Record format:
5332 objcopy -I binary -O srec examples/image examples/image.srec
5334 The 'objcopy' does not understand the information in the U-Boot
5335 image header, so the resulting S-Record file will be relative to
5336 address 0x00000000. To load it to a given address, you need to
5337 specify the target address as 'offset' parameter with the 'loads'
5340 Example: install the image to address 0x40100000 (which on the
5341 TQM8xxL is in the first Flash bank):
5343 => erase 40100000 401FFFFF
5349 ## Ready for S-Record download ...
5350 ~>examples/image.srec
5351 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5353 15989 15990 15991 15992
5354 [file transfer complete]
5356 ## Start Addr = 0x00000000
5359 You can check the success of the download using the 'iminfo' command;
5360 this includes a checksum verification so you can be sure no data
5361 corruption happened:
5365 ## Checking Image at 40100000 ...
5366 Image Name: 2.2.13 for initrd on TQM850L
5367 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5368 Data Size: 335725 Bytes = 327 kB = 0 MB
5369 Load Address: 00000000
5370 Entry Point: 0000000c
5371 Verifying Checksum ... OK
5377 The "bootm" command is used to boot an application that is stored in
5378 memory (RAM or Flash). In case of a Linux kernel image, the contents
5379 of the "bootargs" environment variable is passed to the kernel as
5380 parameters. You can check and modify this variable using the
5381 "printenv" and "setenv" commands:
5384 => printenv bootargs
5385 bootargs=root=/dev/ram
5387 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5389 => printenv bootargs
5390 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5393 ## Booting Linux kernel at 40020000 ...
5394 Image Name: 2.2.13 for NFS on TQM850L
5395 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5396 Data Size: 381681 Bytes = 372 kB = 0 MB
5397 Load Address: 00000000
5398 Entry Point: 0000000c
5399 Verifying Checksum ... OK
5400 Uncompressing Kernel Image ... OK
5401 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
5402 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5403 time_init: decrementer frequency = 187500000/60
5404 Calibrating delay loop... 49.77 BogoMIPS
5405 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5408 If you want to boot a Linux kernel with initial RAM disk, you pass
5409 the memory addresses of both the kernel and the initrd image (PPBCOOT
5410 format!) to the "bootm" command:
5412 => imi 40100000 40200000
5414 ## Checking Image at 40100000 ...
5415 Image Name: 2.2.13 for initrd on TQM850L
5416 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5417 Data Size: 335725 Bytes = 327 kB = 0 MB
5418 Load Address: 00000000
5419 Entry Point: 0000000c
5420 Verifying Checksum ... OK
5422 ## Checking Image at 40200000 ...
5423 Image Name: Simple Ramdisk Image
5424 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5425 Data Size: 566530 Bytes = 553 kB = 0 MB
5426 Load Address: 00000000
5427 Entry Point: 00000000
5428 Verifying Checksum ... OK
5430 => bootm 40100000 40200000
5431 ## Booting Linux kernel at 40100000 ...
5432 Image Name: 2.2.13 for initrd on TQM850L
5433 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5434 Data Size: 335725 Bytes = 327 kB = 0 MB
5435 Load Address: 00000000
5436 Entry Point: 0000000c
5437 Verifying Checksum ... OK
5438 Uncompressing Kernel Image ... OK
5439 ## Loading RAMDisk Image at 40200000 ...
5440 Image Name: Simple Ramdisk Image
5441 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5442 Data Size: 566530 Bytes = 553 kB = 0 MB
5443 Load Address: 00000000
5444 Entry Point: 00000000
5445 Verifying Checksum ... OK
5446 Loading Ramdisk ... OK
5447 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
5448 Boot arguments: root=/dev/ram
5449 time_init: decrementer frequency = 187500000/60
5450 Calibrating delay loop... 49.77 BogoMIPS
5452 RAMDISK: Compressed image found at block 0
5453 VFS: Mounted root (ext2 filesystem).
5457 Boot Linux and pass a flat device tree:
5460 First, U-Boot must be compiled with the appropriate defines. See the section
5461 titled "Linux Kernel Interface" above for a more in depth explanation. The
5462 following is an example of how to start a kernel and pass an updated
5468 oft=oftrees/mpc8540ads.dtb
5469 => tftp $oftaddr $oft
5470 Speed: 1000, full duplex
5472 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5473 Filename 'oftrees/mpc8540ads.dtb'.
5474 Load address: 0x300000
5477 Bytes transferred = 4106 (100a hex)
5478 => tftp $loadaddr $bootfile
5479 Speed: 1000, full duplex
5481 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5483 Load address: 0x200000
5484 Loading:############
5486 Bytes transferred = 1029407 (fb51f hex)
5491 => bootm $loadaddr - $oftaddr
5492 ## Booting image at 00200000 ...
5493 Image Name: Linux-2.6.17-dirty
5494 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5495 Data Size: 1029343 Bytes = 1005.2 kB
5496 Load Address: 00000000
5497 Entry Point: 00000000
5498 Verifying Checksum ... OK
5499 Uncompressing Kernel Image ... OK
5500 Booting using flat device tree at 0x300000
5501 Using MPC85xx ADS machine description
5502 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5506 More About U-Boot Image Types:
5507 ------------------------------
5509 U-Boot supports the following image types:
5511 "Standalone Programs" are directly runnable in the environment
5512 provided by U-Boot; it is expected that (if they behave
5513 well) you can continue to work in U-Boot after return from
5514 the Standalone Program.
5515 "OS Kernel Images" are usually images of some Embedded OS which
5516 will take over control completely. Usually these programs
5517 will install their own set of exception handlers, device
5518 drivers, set up the MMU, etc. - this means, that you cannot
5519 expect to re-enter U-Boot except by resetting the CPU.
5520 "RAMDisk Images" are more or less just data blocks, and their
5521 parameters (address, size) are passed to an OS kernel that is
5523 "Multi-File Images" contain several images, typically an OS
5524 (Linux) kernel image and one or more data images like
5525 RAMDisks. This construct is useful for instance when you want
5526 to boot over the network using BOOTP etc., where the boot
5527 server provides just a single image file, but you want to get
5528 for instance an OS kernel and a RAMDisk image.
5530 "Multi-File Images" start with a list of image sizes, each
5531 image size (in bytes) specified by an "uint32_t" in network
5532 byte order. This list is terminated by an "(uint32_t)0".
5533 Immediately after the terminating 0 follow the images, one by
5534 one, all aligned on "uint32_t" boundaries (size rounded up to
5535 a multiple of 4 bytes).
5537 "Firmware Images" are binary images containing firmware (like
5538 U-Boot or FPGA images) which usually will be programmed to
5541 "Script files" are command sequences that will be executed by
5542 U-Boot's command interpreter; this feature is especially
5543 useful when you configure U-Boot to use a real shell (hush)
5544 as command interpreter.
5546 Booting the Linux zImage:
5547 -------------------------
5549 On some platforms, it's possible to boot Linux zImage. This is done
5550 using the "bootz" command. The syntax of "bootz" command is the same
5551 as the syntax of "bootm" command.
5553 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5554 kernel with raw initrd images. The syntax is slightly different, the
5555 address of the initrd must be augmented by it's size, in the following
5556 format: "<initrd addres>:<initrd size>".
5562 One of the features of U-Boot is that you can dynamically load and
5563 run "standalone" applications, which can use some resources of
5564 U-Boot like console I/O functions or interrupt services.
5566 Two simple examples are included with the sources:
5571 'examples/hello_world.c' contains a small "Hello World" Demo
5572 application; it is automatically compiled when you build U-Boot.
5573 It's configured to run at address 0x00040004, so you can play with it
5577 ## Ready for S-Record download ...
5578 ~>examples/hello_world.srec
5579 1 2 3 4 5 6 7 8 9 10 11 ...
5580 [file transfer complete]
5582 ## Start Addr = 0x00040004
5584 => go 40004 Hello World! This is a test.
5585 ## Starting application at 0x00040004 ...
5596 Hit any key to exit ...
5598 ## Application terminated, rc = 0x0
5600 Another example, which demonstrates how to register a CPM interrupt
5601 handler with the U-Boot code, can be found in 'examples/timer.c'.
5602 Here, a CPM timer is set up to generate an interrupt every second.
5603 The interrupt service routine is trivial, just printing a '.'
5604 character, but this is just a demo program. The application can be
5605 controlled by the following keys:
5607 ? - print current values og the CPM Timer registers
5608 b - enable interrupts and start timer
5609 e - stop timer and disable interrupts
5610 q - quit application
5613 ## Ready for S-Record download ...
5614 ~>examples/timer.srec
5615 1 2 3 4 5 6 7 8 9 10 11 ...
5616 [file transfer complete]
5618 ## Start Addr = 0x00040004
5621 ## Starting application at 0x00040004 ...
5624 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5627 [q, b, e, ?] Set interval 1000000 us
5630 [q, b, e, ?] ........
5631 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5634 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5637 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5640 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5642 [q, b, e, ?] ...Stopping timer
5644 [q, b, e, ?] ## Application terminated, rc = 0x0
5650 Over time, many people have reported problems when trying to use the
5651 "minicom" terminal emulation program for serial download. I (wd)
5652 consider minicom to be broken, and recommend not to use it. Under
5653 Unix, I recommend to use C-Kermit for general purpose use (and
5654 especially for kermit binary protocol download ("loadb" command), and
5655 use "cu" for S-Record download ("loads" command). See
5656 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5657 for help with kermit.
5660 Nevertheless, if you absolutely want to use it try adding this
5661 configuration to your "File transfer protocols" section:
5663 Name Program Name U/D FullScr IO-Red. Multi
5664 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5665 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5671 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5672 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5674 Building requires a cross environment; it is known to work on
5675 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5676 need gmake since the Makefiles are not compatible with BSD make).
5677 Note that the cross-powerpc package does not install include files;
5678 attempting to build U-Boot will fail because <machine/ansi.h> is
5679 missing. This file has to be installed and patched manually:
5681 # cd /usr/pkg/cross/powerpc-netbsd/include
5683 # ln -s powerpc machine
5684 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5685 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5687 Native builds *don't* work due to incompatibilities between native
5688 and U-Boot include files.
5690 Booting assumes that (the first part of) the image booted is a
5691 stage-2 loader which in turn loads and then invokes the kernel
5692 proper. Loader sources will eventually appear in the NetBSD source
5693 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5694 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5697 Implementation Internals:
5698 =========================
5700 The following is not intended to be a complete description of every
5701 implementation detail. However, it should help to understand the
5702 inner workings of U-Boot and make it easier to port it to custom
5706 Initial Stack, Global Data:
5707 ---------------------------
5709 The implementation of U-Boot is complicated by the fact that U-Boot
5710 starts running out of ROM (flash memory), usually without access to
5711 system RAM (because the memory controller is not initialized yet).
5712 This means that we don't have writable Data or BSS segments, and BSS
5713 is not initialized as zero. To be able to get a C environment working
5714 at all, we have to allocate at least a minimal stack. Implementation
5715 options for this are defined and restricted by the CPU used: Some CPU
5716 models provide on-chip memory (like the IMMR area on MPC8xx and
5717 MPC826x processors), on others (parts of) the data cache can be
5718 locked as (mis-) used as memory, etc.
5720 Chris Hallinan posted a good summary of these issues to the
5721 U-Boot mailing list:
5723 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5724 From: "Chris Hallinan" <clh@net1plus.com>
5725 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5728 Correct me if I'm wrong, folks, but the way I understand it
5729 is this: Using DCACHE as initial RAM for Stack, etc, does not
5730 require any physical RAM backing up the cache. The cleverness
5731 is that the cache is being used as a temporary supply of
5732 necessary storage before the SDRAM controller is setup. It's
5733 beyond the scope of this list to explain the details, but you
5734 can see how this works by studying the cache architecture and
5735 operation in the architecture and processor-specific manuals.
5737 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5738 is another option for the system designer to use as an
5739 initial stack/RAM area prior to SDRAM being available. Either
5740 option should work for you. Using CS 4 should be fine if your
5741 board designers haven't used it for something that would
5742 cause you grief during the initial boot! It is frequently not
5745 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5746 with your processor/board/system design. The default value
5747 you will find in any recent u-boot distribution in
5748 walnut.h should work for you. I'd set it to a value larger
5749 than your SDRAM module. If you have a 64MB SDRAM module, set
5750 it above 400_0000. Just make sure your board has no resources
5751 that are supposed to respond to that address! That code in
5752 start.S has been around a while and should work as is when
5753 you get the config right.
5758 It is essential to remember this, since it has some impact on the C
5759 code for the initialization procedures:
5761 * Initialized global data (data segment) is read-only. Do not attempt
5764 * Do not use any uninitialized global data (or implicitely initialized
5765 as zero data - BSS segment) at all - this is undefined, initiali-
5766 zation is performed later (when relocating to RAM).
5768 * Stack space is very limited. Avoid big data buffers or things like
5771 Having only the stack as writable memory limits means we cannot use
5772 normal global data to share information beween the code. But it
5773 turned out that the implementation of U-Boot can be greatly
5774 simplified by making a global data structure (gd_t) available to all
5775 functions. We could pass a pointer to this data as argument to _all_
5776 functions, but this would bloat the code. Instead we use a feature of
5777 the GCC compiler (Global Register Variables) to share the data: we
5778 place a pointer (gd) to the global data into a register which we
5779 reserve for this purpose.
5781 When choosing a register for such a purpose we are restricted by the
5782 relevant (E)ABI specifications for the current architecture, and by
5783 GCC's implementation.
5785 For PowerPC, the following registers have specific use:
5787 R2: reserved for system use
5788 R3-R4: parameter passing and return values
5789 R5-R10: parameter passing
5790 R13: small data area pointer
5794 (U-Boot also uses R12 as internal GOT pointer. r12
5795 is a volatile register so r12 needs to be reset when
5796 going back and forth between asm and C)
5798 ==> U-Boot will use R2 to hold a pointer to the global data
5800 Note: on PPC, we could use a static initializer (since the
5801 address of the global data structure is known at compile time),
5802 but it turned out that reserving a register results in somewhat
5803 smaller code - although the code savings are not that big (on
5804 average for all boards 752 bytes for the whole U-Boot image,
5805 624 text + 127 data).
5807 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5808 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5810 ==> U-Boot will use P3 to hold a pointer to the global data
5812 On ARM, the following registers are used:
5814 R0: function argument word/integer result
5815 R1-R3: function argument word
5816 R9: platform specific
5817 R10: stack limit (used only if stack checking is enabled)
5818 R11: argument (frame) pointer
5819 R12: temporary workspace
5822 R15: program counter
5824 ==> U-Boot will use R9 to hold a pointer to the global data
5826 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5828 On Nios II, the ABI is documented here:
5829 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5831 ==> U-Boot will use gp to hold a pointer to the global data
5833 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5834 to access small data sections, so gp is free.
5836 On NDS32, the following registers are used:
5838 R0-R1: argument/return
5840 R15: temporary register for assembler
5841 R16: trampoline register
5842 R28: frame pointer (FP)
5843 R29: global pointer (GP)
5844 R30: link register (LP)
5845 R31: stack pointer (SP)
5846 PC: program counter (PC)
5848 ==> U-Boot will use R10 to hold a pointer to the global data
5850 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5851 or current versions of GCC may "optimize" the code too much.
5856 U-Boot runs in system state and uses physical addresses, i.e. the
5857 MMU is not used either for address mapping nor for memory protection.
5859 The available memory is mapped to fixed addresses using the memory
5860 controller. In this process, a contiguous block is formed for each
5861 memory type (Flash, SDRAM, SRAM), even when it consists of several
5862 physical memory banks.
5864 U-Boot is installed in the first 128 kB of the first Flash bank (on
5865 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5866 booting and sizing and initializing DRAM, the code relocates itself
5867 to the upper end of DRAM. Immediately below the U-Boot code some
5868 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5869 configuration setting]. Below that, a structure with global Board
5870 Info data is placed, followed by the stack (growing downward).
5872 Additionally, some exception handler code is copied to the low 8 kB
5873 of DRAM (0x00000000 ... 0x00001FFF).
5875 So a typical memory configuration with 16 MB of DRAM could look like
5878 0x0000 0000 Exception Vector code
5881 0x0000 2000 Free for Application Use
5887 0x00FB FF20 Monitor Stack (Growing downward)
5888 0x00FB FFAC Board Info Data and permanent copy of global data
5889 0x00FC 0000 Malloc Arena
5892 0x00FE 0000 RAM Copy of Monitor Code
5893 ... eventually: LCD or video framebuffer
5894 ... eventually: pRAM (Protected RAM - unchanged by reset)
5895 0x00FF FFFF [End of RAM]
5898 System Initialization:
5899 ----------------------
5901 In the reset configuration, U-Boot starts at the reset entry point
5902 (on most PowerPC systems at address 0x00000100). Because of the reset
5903 configuration for CS0# this is a mirror of the onboard Flash memory.
5904 To be able to re-map memory U-Boot then jumps to its link address.
5905 To be able to implement the initialization code in C, a (small!)
5906 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5907 which provide such a feature like MPC8xx or MPC8260), or in a locked
5908 part of the data cache. After that, U-Boot initializes the CPU core,
5909 the caches and the SIU.
5911 Next, all (potentially) available memory banks are mapped using a
5912 preliminary mapping. For example, we put them on 512 MB boundaries
5913 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5914 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5915 programmed for SDRAM access. Using the temporary configuration, a
5916 simple memory test is run that determines the size of the SDRAM
5919 When there is more than one SDRAM bank, and the banks are of
5920 different size, the largest is mapped first. For equal size, the first
5921 bank (CS2#) is mapped first. The first mapping is always for address
5922 0x00000000, with any additional banks following immediately to create
5923 contiguous memory starting from 0.
5925 Then, the monitor installs itself at the upper end of the SDRAM area
5926 and allocates memory for use by malloc() and for the global Board
5927 Info data; also, the exception vector code is copied to the low RAM
5928 pages, and the final stack is set up.
5930 Only after this relocation will you have a "normal" C environment;
5931 until that you are restricted in several ways, mostly because you are
5932 running from ROM, and because the code will have to be relocated to a
5936 U-Boot Porting Guide:
5937 ----------------------
5939 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5943 int main(int argc, char *argv[])
5945 sighandler_t no_more_time;
5947 signal(SIGALRM, no_more_time);
5948 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5950 if (available_money > available_manpower) {
5951 Pay consultant to port U-Boot;
5955 Download latest U-Boot source;
5957 Subscribe to u-boot mailing list;
5960 email("Hi, I am new to U-Boot, how do I get started?");
5963 Read the README file in the top level directory;
5964 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5965 Read applicable doc/*.README;
5966 Read the source, Luke;
5967 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5970 if (available_money > toLocalCurrency ($2500))
5973 Add a lot of aggravation and time;
5975 if (a similar board exists) { /* hopefully... */
5976 cp -a board/<similar> board/<myboard>
5977 cp include/configs/<similar>.h include/configs/<myboard>.h
5979 Create your own board support subdirectory;
5980 Create your own board include/configs/<myboard>.h file;
5982 Edit new board/<myboard> files
5983 Edit new include/configs/<myboard>.h
5988 Add / modify source code;
5992 email("Hi, I am having problems...");
5994 Send patch file to the U-Boot email list;
5995 if (reasonable critiques)
5996 Incorporate improvements from email list code review;
5998 Defend code as written;
6004 void no_more_time (int sig)
6013 All contributions to U-Boot should conform to the Linux kernel
6014 coding style; see the file "Documentation/CodingStyle" and the script
6015 "scripts/Lindent" in your Linux kernel source directory.
6017 Source files originating from a different project (for example the
6018 MTD subsystem) are generally exempt from these guidelines and are not
6019 reformated to ease subsequent migration to newer versions of those
6022 Please note that U-Boot is implemented in C (and to some small parts in
6023 Assembler); no C++ is used, so please do not use C++ style comments (//)
6026 Please also stick to the following formatting rules:
6027 - remove any trailing white space
6028 - use TAB characters for indentation and vertical alignment, not spaces
6029 - make sure NOT to use DOS '\r\n' line feeds
6030 - do not add more than 2 consecutive empty lines to source files
6031 - do not add trailing empty lines to source files
6033 Submissions which do not conform to the standards may be returned
6034 with a request to reformat the changes.
6040 Since the number of patches for U-Boot is growing, we need to
6041 establish some rules. Submissions which do not conform to these rules
6042 may be rejected, even when they contain important and valuable stuff.
6044 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6046 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6047 see http://lists.denx.de/mailman/listinfo/u-boot
6049 When you send a patch, please include the following information with
6052 * For bug fixes: a description of the bug and how your patch fixes
6053 this bug. Please try to include a way of demonstrating that the
6054 patch actually fixes something.
6056 * For new features: a description of the feature and your
6059 * A CHANGELOG entry as plaintext (separate from the patch)
6061 * For major contributions, your entry to the CREDITS file
6063 * When you add support for a new board, don't forget to add a
6064 maintainer e-mail address to the boards.cfg file, too.
6066 * If your patch adds new configuration options, don't forget to
6067 document these in the README file.
6069 * The patch itself. If you are using git (which is *strongly*
6070 recommended) you can easily generate the patch using the
6071 "git format-patch". If you then use "git send-email" to send it to
6072 the U-Boot mailing list, you will avoid most of the common problems
6073 with some other mail clients.
6075 If you cannot use git, use "diff -purN OLD NEW". If your version of
6076 diff does not support these options, then get the latest version of
6079 The current directory when running this command shall be the parent
6080 directory of the U-Boot source tree (i. e. please make sure that
6081 your patch includes sufficient directory information for the
6084 We prefer patches as plain text. MIME attachments are discouraged,
6085 and compressed attachments must not be used.
6087 * If one logical set of modifications affects or creates several
6088 files, all these changes shall be submitted in a SINGLE patch file.
6090 * Changesets that contain different, unrelated modifications shall be
6091 submitted as SEPARATE patches, one patch per changeset.
6096 * Before sending the patch, run the MAKEALL script on your patched
6097 source tree and make sure that no errors or warnings are reported
6098 for any of the boards.
6100 * Keep your modifications to the necessary minimum: A patch
6101 containing several unrelated changes or arbitrary reformats will be
6102 returned with a request to re-formatting / split it.
6104 * If you modify existing code, make sure that your new code does not
6105 add to the memory footprint of the code ;-) Small is beautiful!
6106 When adding new features, these should compile conditionally only
6107 (using #ifdef), and the resulting code with the new feature
6108 disabled must not need more memory than the old code without your
6111 * Remember that there is a size limit of 100 kB per message on the
6112 u-boot mailing list. Bigger patches will be moderated. If they are
6113 reasonable and not too big, they will be acknowledged. But patches
6114 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob