2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /pxa Files specific to Intel XScale PXA CPUs
145 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 /lib Architecture specific library files
147 /avr32 Files generic to AVR32 architecture
148 /cpu CPU specific files
149 /lib Architecture specific library files
150 /blackfin Files generic to Analog Devices Blackfin architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /m68k Files generic to m68k architecture
154 /cpu CPU specific files
155 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
156 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
157 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
158 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
159 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
160 /lib Architecture specific library files
161 /microblaze Files generic to microblaze architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /mips Files generic to MIPS architecture
165 /cpu CPU specific files
166 /mips32 Files specific to MIPS32 CPUs
167 /xburst Files specific to Ingenic XBurst CPUs
168 /lib Architecture specific library files
169 /nds32 Files generic to NDS32 architecture
170 /cpu CPU specific files
171 /n1213 Files specific to Andes Technology N1213 CPUs
172 /lib Architecture specific library files
173 /nios2 Files generic to Altera NIOS2 architecture
174 /cpu CPU specific files
175 /lib Architecture specific library files
176 /openrisc Files generic to OpenRISC architecture
177 /cpu CPU specific files
178 /lib Architecture specific library files
179 /powerpc Files generic to PowerPC architecture
180 /cpu CPU specific files
181 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
182 /mpc5xx Files specific to Freescale MPC5xx CPUs
183 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
184 /mpc8xx Files specific to Freescale MPC8xx CPUs
185 /mpc824x Files specific to Freescale MPC824x CPUs
186 /mpc8260 Files specific to Freescale MPC8260 CPUs
187 /mpc85xx Files specific to Freescale MPC85xx CPUs
188 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
189 /lib Architecture specific library files
190 /sh Files generic to SH architecture
191 /cpu CPU specific files
192 /sh2 Files specific to sh2 CPUs
193 /sh3 Files specific to sh3 CPUs
194 /sh4 Files specific to sh4 CPUs
195 /lib Architecture specific library files
196 /sparc Files generic to SPARC architecture
197 /cpu CPU specific files
198 /leon2 Files specific to Gaisler LEON2 SPARC CPU
199 /leon3 Files specific to Gaisler LEON3 SPARC CPU
200 /lib Architecture specific library files
201 /x86 Files generic to x86 architecture
202 /cpu CPU specific files
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /dts Contains Makefile for building internal U-Boot fdt.
211 /examples Example code for standalone applications, etc.
212 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
213 /include Header Files
214 /lib Files generic to all architectures
215 /libfdt Library files to support flattened device trees
216 /lzma Library files to support LZMA decompression
217 /lzo Library files to support LZO decompression
219 /post Power On Self Test
220 /spl Secondary Program Loader framework
221 /tools Tools to build S-Record or U-Boot images, etc.
223 Software Configuration:
224 =======================
226 Configuration is usually done using C preprocessor defines; the
227 rationale behind that is to avoid dead code whenever possible.
229 There are two classes of configuration variables:
231 * Configuration _OPTIONS_:
232 These are selectable by the user and have names beginning with
235 * Configuration _SETTINGS_:
236 These depend on the hardware etc. and should not be meddled with if
237 you don't know what you're doing; they have names beginning with
240 Later we will add a configuration tool - probably similar to or even
241 identical to what's used for the Linux kernel. Right now, we have to
242 do the configuration by hand, which means creating some symbolic
243 links and editing some configuration files. We use the TQM8xxL boards
247 Selection of Processor Architecture and Board Type:
248 ---------------------------------------------------
250 For all supported boards there are ready-to-use default
251 configurations available; just type "make <board_name>_config".
253 Example: For a TQM823L module type:
258 For the Cogent platform, you need to specify the CPU type as well;
259 e.g. "make cogent_mpc8xx_config". And also configure the cogent
260 directory according to the instructions in cogent/README.
263 Configuration Options:
264 ----------------------
266 Configuration depends on the combination of board and CPU type; all
267 such information is kept in a configuration file
268 "include/configs/<board_name>.h".
270 Example: For a TQM823L module, all configuration settings are in
271 "include/configs/TQM823L.h".
274 Many of the options are named exactly as the corresponding Linux
275 kernel configuration options. The intention is to make it easier to
276 build a config tool - later.
279 The following options need to be configured:
281 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
283 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
285 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
286 Define exactly one, e.g. CONFIG_ATSTK1002
288 - CPU Module Type: (if CONFIG_COGENT is defined)
289 Define exactly one of
291 --- FIXME --- not tested yet:
292 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
293 CONFIG_CMA287_23, CONFIG_CMA287_50
295 - Motherboard Type: (if CONFIG_COGENT is defined)
296 Define exactly one of
297 CONFIG_CMA101, CONFIG_CMA102
299 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
300 Define one or more of
303 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
304 Define one or more of
305 CONFIG_LCD_HEARTBEAT - update a character position on
306 the LCD display every second with
309 - Board flavour: (if CONFIG_MPC8260ADS is defined)
312 CONFIG_SYS_8260ADS - original MPC8260ADS
313 CONFIG_SYS_8266ADS - MPC8266ADS
314 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
315 CONFIG_SYS_8272ADS - MPC8272ADS
317 - Marvell Family Member
318 CONFIG_SYS_MVFS - define it if you want to enable
319 multiple fs option at one time
320 for marvell soc family
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
357 Specifies that the core is a 64-bit PowerPC implementation (implements
358 the "64" category of the Power ISA). This is necessary for ePAPR
359 compliance, among other possible reasons.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 CONFIG_SYS_PPC_E500_DEBUG_TLB
374 Enables a temporary TLB entry to be used during boot to work
375 around limitations in e500v1 and e500v2 external debugger
376 support. This reduces the portions of the boot code where
377 breakpoints and single stepping do not work. The value of this
378 symbol should be set to the TLB1 entry to be used for this
381 CONFIG_SYS_FSL_ERRATUM_A004510
383 Enables a workaround for erratum A004510. If set,
384 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
390 Defines one or two SoC revisions (low 8 bits of SVR)
391 for which the A004510 workaround should be applied.
393 The rest of SVR is either not relevant to the decision
394 of whether the erratum is present (e.g. p2040 versus
395 p2041) or is implied by the build target, which controls
396 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
398 See Freescale App Note 4493 for more information about
401 CONFIG_A003399_NOR_WORKAROUND
402 Enables a workaround for IFC erratum A003399. It is only
403 requred during NOR boot.
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
437 Freescale DDR driver in use. This type of DDR controller is
438 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
441 CONFIG_SYS_FSL_DDR_ADDR
442 Freescale DDR memory-mapped register base.
444 CONFIG_SYS_FSL_DDR_EMU
445 Specify emulator support for DDR. Some DDR features such as
446 deskew training are not available.
448 CONFIG_SYS_FSL_DDRC_GEN1
449 Freescale DDR1 controller.
451 CONFIG_SYS_FSL_DDRC_GEN2
452 Freescale DDR2 controller.
454 CONFIG_SYS_FSL_DDRC_GEN3
455 Freescale DDR3 controller.
457 CONFIG_SYS_FSL_DDRC_ARM_GEN3
458 Freescale DDR3 controller for ARM-based SoCs.
461 Board config to use DDR1. It can be enabled for SoCs with
462 Freescale DDR1 or DDR2 controllers, depending on the board
466 Board config to use DDR2. It can be eanbeld for SoCs with
467 Freescale DDR2 or DDR3 controllers, depending on the board
471 Board config to use DDR3. It can be enabled for SoCs with
472 Freescale DDR3 controllers.
474 CONFIG_SYS_FSL_IFC_BE
475 Defines the IFC controller register space as Big Endian
477 CONFIG_SYS_FSL_IFC_LE
478 Defines the IFC controller register space as Little Endian
480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
489 CONFIG_SYS_FSL_DDR_BE
490 Defines the DDR controller register space as Big Endian
492 CONFIG_SYS_FSL_DDR_LE
493 Defines the DDR controller register space as Little Endian
495 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
496 Physical address from the view of DDR controllers. It is the
497 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
498 it could be different for ARM SoCs.
500 CONFIG_SYS_FSL_DDR_INTLV_256B
501 DDR controller interleaving on 256-byte. This is a special
502 interleaving mode, handled by Dickens for Freescale layerscape
505 - Intel Monahans options:
506 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
508 Defines the Monahans run mode to oscillator
509 ratio. Valid values are 8, 16, 24, 31. The core
510 frequency is this value multiplied by 13 MHz.
512 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
514 Defines the Monahans turbo mode to oscillator
515 ratio. Valid values are 1 (default if undefined) and
516 2. The core frequency as calculated above is multiplied
520 CONFIG_SYS_INIT_SP_OFFSET
522 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
523 pointer. This is needed for the temporary stack before
526 CONFIG_SYS_MIPS_CACHE_MODE
528 Cache operation mode for the MIPS CPU.
529 See also arch/mips/include/asm/mipsregs.h.
531 CONF_CM_CACHABLE_NO_WA
534 CONF_CM_CACHABLE_NONCOHERENT
538 CONF_CM_CACHABLE_ACCELERATED
540 CONFIG_SYS_XWAY_EBU_BOOTCFG
542 Special option for Lantiq XWAY SoCs for booting from NOR flash.
543 See also arch/mips/cpu/mips32/start.S.
545 CONFIG_XWAY_SWAP_BYTES
547 Enable compilation of tools/xway-swap-bytes needed for Lantiq
548 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
549 be swapped if a flash programmer is used.
552 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
554 Select high exception vectors of the ARM core, e.g., do not
555 clear the V bit of the c1 register of CP15.
557 CONFIG_SYS_THUMB_BUILD
559 Use this flag to build U-Boot using the Thumb instruction
560 set for ARM architectures. Thumb instruction set provides
561 better code density. For ARM architectures that support
562 Thumb2 this flag will result in Thumb2 code generated by
565 CONFIG_ARM_ERRATA_716044
566 CONFIG_ARM_ERRATA_742230
567 CONFIG_ARM_ERRATA_743622
568 CONFIG_ARM_ERRATA_751472
570 If set, the workarounds for these ARM errata are applied early
571 during U-Boot startup. Note that these options force the
572 workarounds to be applied; no CPU-type/version detection
573 exists, unlike the similar options in the Linux kernel. Do not
574 set these options unless they apply!
579 The frequency of the timer returned by get_timer().
580 get_timer() must operate in milliseconds and this CONFIG
581 option must be set to 1000.
583 - Linux Kernel Interface:
586 U-Boot stores all clock information in Hz
587 internally. For binary compatibility with older Linux
588 kernels (which expect the clocks passed in the
589 bd_info data to be in MHz) the environment variable
590 "clocks_in_mhz" can be defined so that U-Boot
591 converts clock data to MHZ before passing it to the
593 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
594 "clocks_in_mhz=1" is automatically included in the
597 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
599 When transferring memsize parameter to linux, some versions
600 expect it to be in bytes, others in MB.
601 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
605 New kernel versions are expecting firmware settings to be
606 passed using flattened device trees (based on open firmware
610 * New libfdt-based support
611 * Adds the "fdt" command
612 * The bootm command automatically updates the fdt
614 OF_CPU - The proper name of the cpus node (only required for
615 MPC512X and MPC5xxx based boards).
616 OF_SOC - The proper name of the soc node (only required for
617 MPC512X and MPC5xxx based boards).
618 OF_TBCLK - The timebase frequency.
619 OF_STDOUT_PATH - The path to the console device
621 boards with QUICC Engines require OF_QE to set UCC MAC
624 CONFIG_OF_BOARD_SETUP
626 Board code has addition modification that it wants to make
627 to the flat device tree before handing it off to the kernel
631 This define fills in the correct boot CPU in the boot
632 param header, the default value is zero if undefined.
636 U-Boot can detect if an IDE device is present or not.
637 If not, and this new config option is activated, U-Boot
638 removes the ATA node from the DTS before booting Linux,
639 so the Linux IDE driver does not probe the device and
640 crash. This is needed for buggy hardware (uc101) where
641 no pull down resistor is connected to the signal IDE5V_DD7.
643 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
645 This setting is mandatory for all boards that have only one
646 machine type and must be used to specify the machine type
647 number as it appears in the ARM machine registry
648 (see http://www.arm.linux.org.uk/developer/machines/).
649 Only boards that have multiple machine types supported
650 in a single configuration file and the machine type is
651 runtime discoverable, do not have to use this setting.
653 - vxWorks boot parameters:
655 bootvx constructs a valid bootline using the following
656 environments variables: bootfile, ipaddr, serverip, hostname.
657 It loads the vxWorks image pointed bootfile.
659 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
660 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
661 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
662 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
664 CONFIG_SYS_VXWORKS_ADD_PARAMS
666 Add it at the end of the bootline. E.g "u=username pw=secret"
668 Note: If a "bootargs" environment is defined, it will overwride
669 the defaults discussed just above.
671 - Cache Configuration:
672 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
673 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
674 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
676 - Cache Configuration for ARM:
677 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
679 CONFIG_SYS_PL310_BASE - Physical base address of PL310
680 controller register space
685 Define this if you want support for Amba PrimeCell PL010 UARTs.
689 Define this if you want support for Amba PrimeCell PL011 UARTs.
693 If you have Amba PrimeCell PL011 UARTs, set this variable to
694 the clock speed of the UARTs.
698 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
699 define this to a list of base addresses for each (supported)
700 port. See e.g. include/configs/versatile.h
702 CONFIG_PL011_SERIAL_RLCR
704 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
705 have separate receive and transmit line control registers. Set
706 this variable to initialize the extra register.
708 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
710 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
711 boot loader that has already initialized the UART. Define this
712 variable to flush the UART at init time.
716 Depending on board, define exactly one serial port
717 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
718 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
719 console by defining CONFIG_8xx_CONS_NONE
721 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
722 port routines must be defined elsewhere
723 (i.e. serial_init(), serial_getc(), ...)
726 Enables console device for a color framebuffer. Needs following
727 defines (cf. smiLynxEM, i8042)
728 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
730 VIDEO_HW_RECTFILL graphic chip supports
733 VIDEO_HW_BITBLT graphic chip supports
734 bit-blit (cf. smiLynxEM)
735 VIDEO_VISIBLE_COLS visible pixel columns
737 VIDEO_VISIBLE_ROWS visible pixel rows
738 VIDEO_PIXEL_SIZE bytes per pixel
739 VIDEO_DATA_FORMAT graphic data format
740 (0-5, cf. cfb_console.c)
741 VIDEO_FB_ADRS framebuffer address
742 VIDEO_KBD_INIT_FCT keyboard int fct
743 (i.e. i8042_kbd_init())
744 VIDEO_TSTC_FCT test char fct
746 VIDEO_GETC_FCT get char fct
748 CONFIG_CONSOLE_CURSOR cursor drawing on/off
749 (requires blink timer
751 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
752 CONFIG_CONSOLE_TIME display time/date info in
754 (requires CONFIG_CMD_DATE)
755 CONFIG_VIDEO_LOGO display Linux logo in
757 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
758 linux_logo.h for logo.
759 Requires CONFIG_VIDEO_LOGO
760 CONFIG_CONSOLE_EXTRA_INFO
761 additional board info beside
764 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
765 a limited number of ANSI escape sequences (cursor control,
766 erase functions and limited graphics rendition control).
768 When CONFIG_CFB_CONSOLE is defined, video console is
769 default i/o. Serial console can be forced with
770 environment 'console=serial'.
772 When CONFIG_SILENT_CONSOLE is defined, all console
773 messages (by U-Boot and Linux!) can be silenced with
774 the "silent" environment variable. See
775 doc/README.silent for more information.
777 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
779 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
783 CONFIG_BAUDRATE - in bps
784 Select one of the baudrates listed in
785 CONFIG_SYS_BAUDRATE_TABLE, see below.
786 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
788 - Console Rx buffer length
789 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
790 the maximum receive buffer length for the SMC.
791 This option is actual only for 82xx and 8xx possible.
792 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
793 must be defined, to setup the maximum idle timeout for
796 - Pre-Console Buffer:
797 Prior to the console being initialised (i.e. serial UART
798 initialised etc) all console output is silently discarded.
799 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
800 buffer any console messages prior to the console being
801 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
802 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
803 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
804 bytes are output before the console is initialised, the
805 earlier bytes are discarded.
807 'Sane' compilers will generate smaller code if
808 CONFIG_PRE_CON_BUF_SZ is a power of 2
810 - Safe printf() functions
811 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
812 the printf() functions. These are defined in
813 include/vsprintf.h and include snprintf(), vsnprintf() and
814 so on. Code size increase is approximately 300-500 bytes.
815 If this option is not given then these functions will
816 silently discard their buffer size argument - this means
817 you are not getting any overflow checking in this case.
819 - Boot Delay: CONFIG_BOOTDELAY - in seconds
820 Delay before automatically booting the default image;
821 set to -1 to disable autoboot.
822 set to -2 to autoboot with no delay and not check for abort
823 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
825 See doc/README.autoboot for these options that
826 work with CONFIG_BOOTDELAY. None are required.
827 CONFIG_BOOT_RETRY_TIME
828 CONFIG_BOOT_RETRY_MIN
829 CONFIG_AUTOBOOT_KEYED
830 CONFIG_AUTOBOOT_PROMPT
831 CONFIG_AUTOBOOT_DELAY_STR
832 CONFIG_AUTOBOOT_STOP_STR
833 CONFIG_AUTOBOOT_DELAY_STR2
834 CONFIG_AUTOBOOT_STOP_STR2
835 CONFIG_ZERO_BOOTDELAY_CHECK
836 CONFIG_RESET_TO_RETRY
840 Only needed when CONFIG_BOOTDELAY is enabled;
841 define a command string that is automatically executed
842 when no character is read on the console interface
843 within "Boot Delay" after reset.
846 This can be used to pass arguments to the bootm
847 command. The value of CONFIG_BOOTARGS goes into the
848 environment value "bootargs".
850 CONFIG_RAMBOOT and CONFIG_NFSBOOT
851 The value of these goes into the environment as
852 "ramboot" and "nfsboot" respectively, and can be used
853 as a convenience, when switching between booting from
857 CONFIG_BOOTCOUNT_LIMIT
858 Implements a mechanism for detecting a repeating reboot
860 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
863 If no softreset save registers are found on the hardware
864 "bootcount" is stored in the environment. To prevent a
865 saveenv on all reboots, the environment variable
866 "upgrade_available" is used. If "upgrade_available" is
867 0, "bootcount" is always 0, if "upgrade_available" is
868 1 "bootcount" is incremented in the environment.
869 So the Userspace Applikation must set the "upgrade_available"
870 and "bootcount" variable to 0, if a boot was successfully.
875 When this option is #defined, the existence of the
876 environment variable "preboot" will be checked
877 immediately before starting the CONFIG_BOOTDELAY
878 countdown and/or running the auto-boot command resp.
879 entering interactive mode.
881 This feature is especially useful when "preboot" is
882 automatically generated or modified. For an example
883 see the LWMON board specific code: here "preboot" is
884 modified when the user holds down a certain
885 combination of keys on the (special) keyboard when
888 - Serial Download Echo Mode:
890 If defined to 1, all characters received during a
891 serial download (using the "loads" command) are
892 echoed back. This might be needed by some terminal
893 emulations (like "cu"), but may as well just take
894 time on others. This setting #define's the initial
895 value of the "loads_echo" environment variable.
897 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
899 Select one of the baudrates listed in
900 CONFIG_SYS_BAUDRATE_TABLE, see below.
903 Monitor commands can be included or excluded
904 from the build by using the #include files
905 <config_cmd_all.h> and #undef'ing unwanted
906 commands, or using <config_cmd_default.h>
907 and augmenting with additional #define's
910 The default command configuration includes all commands
911 except those marked below with a "*".
913 CONFIG_CMD_ASKENV * ask for env variable
914 CONFIG_CMD_BDI bdinfo
915 CONFIG_CMD_BEDBUG * Include BedBug Debugger
916 CONFIG_CMD_BMP * BMP support
917 CONFIG_CMD_BSP * Board specific commands
918 CONFIG_CMD_BOOTD bootd
919 CONFIG_CMD_CACHE * icache, dcache
920 CONFIG_CMD_CLK * clock command support
921 CONFIG_CMD_CONSOLE coninfo
922 CONFIG_CMD_CRC32 * crc32
923 CONFIG_CMD_DATE * support for RTC, date/time...
924 CONFIG_CMD_DHCP * DHCP support
925 CONFIG_CMD_DIAG * Diagnostics
926 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
927 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
928 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
929 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
930 CONFIG_CMD_DTT * Digital Therm and Thermostat
931 CONFIG_CMD_ECHO echo arguments
932 CONFIG_CMD_EDITENV edit env variable
933 CONFIG_CMD_EEPROM * EEPROM read/write support
934 CONFIG_CMD_ELF * bootelf, bootvx
935 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
936 CONFIG_CMD_ENV_FLAGS * display details about env flags
937 CONFIG_CMD_ENV_EXISTS * check existence of env variable
938 CONFIG_CMD_EXPORTENV * export the environment
939 CONFIG_CMD_EXT2 * ext2 command support
940 CONFIG_CMD_EXT4 * ext4 command support
941 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
942 that work for multiple fs types
943 CONFIG_CMD_SAVEENV saveenv
944 CONFIG_CMD_FDC * Floppy Disk Support
945 CONFIG_CMD_FAT * FAT command support
946 CONFIG_CMD_FLASH flinfo, erase, protect
947 CONFIG_CMD_FPGA FPGA device initialization support
948 CONFIG_CMD_FUSE * Device fuse support
949 CONFIG_CMD_GETTIME * Get time since boot
950 CONFIG_CMD_GO * the 'go' command (exec code)
951 CONFIG_CMD_GREPENV * search environment
952 CONFIG_CMD_HASH * calculate hash / digest
953 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
954 CONFIG_CMD_I2C * I2C serial bus support
955 CONFIG_CMD_IDE * IDE harddisk support
956 CONFIG_CMD_IMI iminfo
957 CONFIG_CMD_IMLS List all images found in NOR flash
958 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
959 CONFIG_CMD_IMMAP * IMMR dump support
960 CONFIG_CMD_IMPORTENV * import an environment
961 CONFIG_CMD_INI * import data from an ini file into the env
962 CONFIG_CMD_IRQ * irqinfo
963 CONFIG_CMD_ITEST Integer/string test of 2 values
964 CONFIG_CMD_JFFS2 * JFFS2 Support
965 CONFIG_CMD_KGDB * kgdb
966 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
967 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
969 CONFIG_CMD_LOADB loadb
970 CONFIG_CMD_LOADS loads
971 CONFIG_CMD_MD5SUM * print md5 message digest
972 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
973 CONFIG_CMD_MEMINFO * Display detailed memory information
974 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
976 CONFIG_CMD_MEMTEST * mtest
977 CONFIG_CMD_MISC Misc functions like sleep etc
978 CONFIG_CMD_MMC * MMC memory mapped support
979 CONFIG_CMD_MII * MII utility commands
980 CONFIG_CMD_MTDPARTS * MTD partition support
981 CONFIG_CMD_NAND * NAND support
982 CONFIG_CMD_NET bootp, tftpboot, rarpboot
983 CONFIG_CMD_NFS NFS support
984 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
985 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
986 CONFIG_CMD_PCI * pciinfo
987 CONFIG_CMD_PCMCIA * PCMCIA support
988 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
990 CONFIG_CMD_PORTIO * Port I/O
991 CONFIG_CMD_READ * Read raw data from partition
992 CONFIG_CMD_REGINFO * Register dump
993 CONFIG_CMD_RUN run command in env variable
994 CONFIG_CMD_SANDBOX * sb command to access sandbox features
995 CONFIG_CMD_SAVES * save S record dump
996 CONFIG_CMD_SCSI * SCSI Support
997 CONFIG_CMD_SDRAM * print SDRAM configuration information
998 (requires CONFIG_CMD_I2C)
999 CONFIG_CMD_SETGETDCR Support for DCR Register access
1001 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1002 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1003 (requires CONFIG_CMD_MEMORY)
1004 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1005 CONFIG_CMD_SOURCE "source" command Support
1006 CONFIG_CMD_SPI * SPI serial bus support
1007 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1008 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1009 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1010 CONFIG_CMD_TIMER * access to the system tick timer
1011 CONFIG_CMD_USB * USB support
1012 CONFIG_CMD_CDP * Cisco Discover Protocol support
1013 CONFIG_CMD_MFSL * Microblaze FSL support
1014 CONFIG_CMD_XIMG Load part of Multi Image
1017 EXAMPLE: If you want all functions except of network
1018 support you can write:
1020 #include "config_cmd_all.h"
1021 #undef CONFIG_CMD_NET
1024 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1026 Note: Don't enable the "icache" and "dcache" commands
1027 (configuration option CONFIG_CMD_CACHE) unless you know
1028 what you (and your U-Boot users) are doing. Data
1029 cache cannot be enabled on systems like the 8xx or
1030 8260 (where accesses to the IMMR region must be
1031 uncached), and it cannot be disabled on all other
1032 systems where we (mis-) use the data cache to hold an
1033 initial stack and some data.
1036 XXX - this list needs to get updated!
1038 - Regular expression support:
1040 If this variable is defined, U-Boot is linked against
1041 the SLRE (Super Light Regular Expression) library,
1042 which adds regex support to some commands, as for
1043 example "env grep" and "setexpr".
1047 If this variable is defined, U-Boot will use a device tree
1048 to configure its devices, instead of relying on statically
1049 compiled #defines in the board file. This option is
1050 experimental and only available on a few boards. The device
1051 tree is available in the global data as gd->fdt_blob.
1053 U-Boot needs to get its device tree from somewhere. This can
1054 be done using one of the two options below:
1057 If this variable is defined, U-Boot will embed a device tree
1058 binary in its image. This device tree file should be in the
1059 board directory and called <soc>-<board>.dts. The binary file
1060 is then picked up in board_init_f() and made available through
1061 the global data structure as gd->blob.
1064 If this variable is defined, U-Boot will build a device tree
1065 binary. It will be called u-boot.dtb. Architecture-specific
1066 code will locate it at run-time. Generally this works by:
1068 cat u-boot.bin u-boot.dtb >image.bin
1070 and in fact, U-Boot does this for you, creating a file called
1071 u-boot-dtb.bin which is useful in the common case. You can
1072 still use the individual files if you need something more
1077 If this variable is defined, it enables watchdog
1078 support for the SoC. There must be support in the SoC
1079 specific code for a watchdog. For the 8xx and 8260
1080 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1081 register. When supported for a specific SoC is
1082 available, then no further board specific code should
1083 be needed to use it.
1086 When using a watchdog circuitry external to the used
1087 SoC, then define this variable and provide board
1088 specific code for the "hw_watchdog_reset" function.
1091 CONFIG_VERSION_VARIABLE
1092 If this variable is defined, an environment variable
1093 named "ver" is created by U-Boot showing the U-Boot
1094 version as printed by the "version" command.
1095 Any change to this variable will be reverted at the
1100 When CONFIG_CMD_DATE is selected, the type of the RTC
1101 has to be selected, too. Define exactly one of the
1104 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1105 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1106 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1107 CONFIG_RTC_MC146818 - use MC146818 RTC
1108 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1109 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1110 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1111 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1112 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1113 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1114 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1115 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1118 Note that if the RTC uses I2C, then the I2C interface
1119 must also be configured. See I2C Support, below.
1122 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1124 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1125 chip-ngpio pairs that tell the PCA953X driver the number of
1126 pins supported by a particular chip.
1128 Note that if the GPIO device uses I2C, then the I2C interface
1129 must also be configured. See I2C Support, below.
1131 - Timestamp Support:
1133 When CONFIG_TIMESTAMP is selected, the timestamp
1134 (date and time) of an image is printed by image
1135 commands like bootm or iminfo. This option is
1136 automatically enabled when you select CONFIG_CMD_DATE .
1138 - Partition Labels (disklabels) Supported:
1139 Zero or more of the following:
1140 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1141 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1142 Intel architecture, USB sticks, etc.
1143 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1144 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1145 bootloader. Note 2TB partition limit; see
1147 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1149 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1150 CONFIG_CMD_SCSI) you must configure support for at
1151 least one non-MTD partition type as well.
1154 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1155 board configurations files but used nowhere!
1157 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1158 be performed by calling the function
1159 ide_set_reset(int reset)
1160 which has to be defined in a board specific file
1165 Set this to enable ATAPI support.
1170 Set this to enable support for disks larger than 137GB
1171 Also look at CONFIG_SYS_64BIT_LBA.
1172 Whithout these , LBA48 support uses 32bit variables and will 'only'
1173 support disks up to 2.1TB.
1175 CONFIG_SYS_64BIT_LBA:
1176 When enabled, makes the IDE subsystem use 64bit sector addresses.
1180 At the moment only there is only support for the
1181 SYM53C8XX SCSI controller; define
1182 CONFIG_SCSI_SYM53C8XX to enable it.
1184 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1185 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1186 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1187 maximum numbers of LUNs, SCSI ID's and target
1189 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1191 The environment variable 'scsidevs' is set to the number of
1192 SCSI devices found during the last scan.
1194 - NETWORK Support (PCI):
1196 Support for Intel 8254x/8257x gigabit chips.
1199 Utility code for direct access to the SPI bus on Intel 8257x.
1200 This does not do anything useful unless you set at least one
1201 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1203 CONFIG_E1000_SPI_GENERIC
1204 Allow generic access to the SPI bus on the Intel 8257x, for
1205 example with the "sspi" command.
1208 Management command for E1000 devices. When used on devices
1209 with SPI support you can reprogram the EEPROM from U-Boot.
1211 CONFIG_E1000_FALLBACK_MAC
1212 default MAC for empty EEPROM after production.
1215 Support for Intel 82557/82559/82559ER chips.
1216 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1217 write routine for first time initialisation.
1220 Support for Digital 2114x chips.
1221 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1222 modem chip initialisation (KS8761/QS6611).
1225 Support for National dp83815 chips.
1228 Support for National dp8382[01] gigabit chips.
1230 - NETWORK Support (other):
1232 CONFIG_DRIVER_AT91EMAC
1233 Support for AT91RM9200 EMAC.
1236 Define this to use reduced MII inteface
1238 CONFIG_DRIVER_AT91EMAC_QUIET
1239 If this defined, the driver is quiet.
1240 The driver doen't show link status messages.
1242 CONFIG_CALXEDA_XGMAC
1243 Support for the Calxeda XGMAC device
1246 Support for SMSC's LAN91C96 chips.
1248 CONFIG_LAN91C96_BASE
1249 Define this to hold the physical address
1250 of the LAN91C96's I/O space
1252 CONFIG_LAN91C96_USE_32_BIT
1253 Define this to enable 32 bit addressing
1256 Support for SMSC's LAN91C111 chip
1258 CONFIG_SMC91111_BASE
1259 Define this to hold the physical address
1260 of the device (I/O space)
1262 CONFIG_SMC_USE_32_BIT
1263 Define this if data bus is 32 bits
1265 CONFIG_SMC_USE_IOFUNCS
1266 Define this to use i/o functions instead of macros
1267 (some hardware wont work with macros)
1269 CONFIG_DRIVER_TI_EMAC
1270 Support for davinci emac
1272 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1273 Define this if you have more then 3 PHYs.
1276 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1278 CONFIG_FTGMAC100_EGIGA
1279 Define this to use GE link update with gigabit PHY.
1280 Define this if FTGMAC100 is connected to gigabit PHY.
1281 If your system has 10/100 PHY only, it might not occur
1282 wrong behavior. Because PHY usually return timeout or
1283 useless data when polling gigabit status and gigabit
1284 control registers. This behavior won't affect the
1285 correctnessof 10/100 link speed update.
1288 Support for SMSC's LAN911x and LAN921x chips
1291 Define this to hold the physical address
1292 of the device (I/O space)
1294 CONFIG_SMC911X_32_BIT
1295 Define this if data bus is 32 bits
1297 CONFIG_SMC911X_16_BIT
1298 Define this if data bus is 16 bits. If your processor
1299 automatically converts one 32 bit word to two 16 bit
1300 words you may also try CONFIG_SMC911X_32_BIT.
1303 Support for Renesas on-chip Ethernet controller
1305 CONFIG_SH_ETHER_USE_PORT
1306 Define the number of ports to be used
1308 CONFIG_SH_ETHER_PHY_ADDR
1309 Define the ETH PHY's address
1311 CONFIG_SH_ETHER_CACHE_WRITEBACK
1312 If this option is set, the driver enables cache flush.
1316 Support TPM devices.
1319 Support for i2c bus TPM devices. Only one device
1320 per system is supported at this time.
1322 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1323 Define the the i2c bus number for the TPM device
1325 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1326 Define the TPM's address on the i2c bus
1328 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1329 Define the burst count bytes upper limit
1331 CONFIG_TPM_ATMEL_TWI
1332 Support for Atmel TWI TPM device. Requires I2C support.
1335 Support for generic parallel port TPM devices. Only one device
1336 per system is supported at this time.
1338 CONFIG_TPM_TIS_BASE_ADDRESS
1339 Base address where the generic TPM device is mapped
1340 to. Contemporary x86 systems usually map it at
1344 Add tpm monitor functions.
1345 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1346 provides monitor access to authorized functions.
1349 Define this to enable the TPM support library which provides
1350 functional interfaces to some TPM commands.
1351 Requires support for a TPM device.
1353 CONFIG_TPM_AUTH_SESSIONS
1354 Define this to enable authorized functions in the TPM library.
1355 Requires CONFIG_TPM and CONFIG_SHA1.
1358 At the moment only the UHCI host controller is
1359 supported (PIP405, MIP405, MPC5200); define
1360 CONFIG_USB_UHCI to enable it.
1361 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1362 and define CONFIG_USB_STORAGE to enable the USB
1365 Supported are USB Keyboards and USB Floppy drives
1367 MPC5200 USB requires additional defines:
1369 for 528 MHz Clock: 0x0001bbbb
1373 for differential drivers: 0x00001000
1374 for single ended drivers: 0x00005000
1375 for differential drivers on PSC3: 0x00000100
1376 for single ended drivers on PSC3: 0x00004100
1377 CONFIG_SYS_USB_EVENT_POLL
1378 May be defined to allow interrupt polling
1379 instead of using asynchronous interrupts
1381 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1382 txfilltuning field in the EHCI controller on reset.
1384 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1385 interval for usb hub power-on delay.(minimum 100msec)
1388 Define the below if you wish to use the USB console.
1389 Once firmware is rebuilt from a serial console issue the
1390 command "setenv stdin usbtty; setenv stdout usbtty" and
1391 attach your USB cable. The Unix command "dmesg" should print
1392 it has found a new device. The environment variable usbtty
1393 can be set to gserial or cdc_acm to enable your device to
1394 appear to a USB host as a Linux gserial device or a
1395 Common Device Class Abstract Control Model serial device.
1396 If you select usbtty = gserial you should be able to enumerate
1398 # modprobe usbserial vendor=0xVendorID product=0xProductID
1399 else if using cdc_acm, simply setting the environment
1400 variable usbtty to be cdc_acm should suffice. The following
1401 might be defined in YourBoardName.h
1404 Define this to build a UDC device
1407 Define this to have a tty type of device available to
1408 talk to the UDC device
1411 Define this to enable the high speed support for usb
1412 device and usbtty. If this feature is enabled, a routine
1413 int is_usbd_high_speed(void)
1414 also needs to be defined by the driver to dynamically poll
1415 whether the enumeration has succeded at high speed or full
1418 CONFIG_SYS_CONSOLE_IS_IN_ENV
1419 Define this if you want stdin, stdout &/or stderr to
1423 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1424 Derive USB clock from external clock "blah"
1425 - CONFIG_SYS_USB_EXTC_CLK 0x02
1427 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1428 Derive USB clock from brgclk
1429 - CONFIG_SYS_USB_BRG_CLK 0x04
1431 If you have a USB-IF assigned VendorID then you may wish to
1432 define your own vendor specific values either in BoardName.h
1433 or directly in usbd_vendor_info.h. If you don't define
1434 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1435 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1436 should pretend to be a Linux device to it's target host.
1438 CONFIG_USBD_MANUFACTURER
1439 Define this string as the name of your company for
1440 - CONFIG_USBD_MANUFACTURER "my company"
1442 CONFIG_USBD_PRODUCT_NAME
1443 Define this string as the name of your product
1444 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1446 CONFIG_USBD_VENDORID
1447 Define this as your assigned Vendor ID from the USB
1448 Implementors Forum. This *must* be a genuine Vendor ID
1449 to avoid polluting the USB namespace.
1450 - CONFIG_USBD_VENDORID 0xFFFF
1452 CONFIG_USBD_PRODUCTID
1453 Define this as the unique Product ID
1455 - CONFIG_USBD_PRODUCTID 0xFFFF
1457 Some USB device drivers may need to check USB cable attachment.
1458 In this case you can enable following config in BoardName.h:
1459 CONFIG_USB_CABLE_CHECK
1460 This enables function definition:
1461 - usb_cable_connected() in include/usb.h
1462 Implementation of this function is board-specific.
1464 - ULPI Layer Support:
1465 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1466 the generic ULPI layer. The generic layer accesses the ULPI PHY
1467 via the platform viewport, so you need both the genric layer and
1468 the viewport enabled. Currently only Chipidea/ARC based
1469 viewport is supported.
1470 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1471 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1472 If your ULPI phy needs a different reference clock than the
1473 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1474 the appropriate value in Hz.
1477 The MMC controller on the Intel PXA is supported. To
1478 enable this define CONFIG_MMC. The MMC can be
1479 accessed from the boot prompt by mapping the device
1480 to physical memory similar to flash. Command line is
1481 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1482 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1485 Support for Renesas on-chip MMCIF controller
1487 CONFIG_SH_MMCIF_ADDR
1488 Define the base address of MMCIF registers
1491 Define the clock frequency for MMCIF
1493 - USB Device Firmware Update (DFU) class support:
1495 This enables the USB portion of the DFU USB class
1498 This enables the command "dfu" which is used to have
1499 U-Boot create a DFU class device via USB. This command
1500 requires that the "dfu_alt_info" environment variable be
1501 set and define the alt settings to expose to the host.
1504 This enables support for exposing (e)MMC devices via DFU.
1507 This enables support for exposing NAND devices via DFU.
1510 This enables support for exposing RAM via DFU.
1511 Note: DFU spec refer to non-volatile memory usage, but
1512 allow usages beyond the scope of spec - here RAM usage,
1513 one that would help mostly the developer.
1515 CONFIG_SYS_DFU_DATA_BUF_SIZE
1516 Dfu transfer uses a buffer before writing data to the
1517 raw storage device. Make the size (in bytes) of this buffer
1518 configurable. The size of this buffer is also configurable
1519 through the "dfu_bufsiz" environment variable.
1521 CONFIG_SYS_DFU_MAX_FILE_SIZE
1522 When updating files rather than the raw storage device,
1523 we use a static buffer to copy the file into and then write
1524 the buffer once we've been given the whole file. Define
1525 this to the maximum filesize (in bytes) for the buffer.
1526 Default is 4 MiB if undefined.
1528 - Journaling Flash filesystem support:
1529 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1530 CONFIG_JFFS2_NAND_DEV
1531 Define these for a default partition on a NAND device
1533 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1534 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1535 Define these for a default partition on a NOR device
1537 CONFIG_SYS_JFFS_CUSTOM_PART
1538 Define this to create an own partition. You have to provide a
1539 function struct part_info* jffs2_part_info(int part_num)
1541 If you define only one JFFS2 partition you may also want to
1542 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1543 to disable the command chpart. This is the default when you
1544 have not defined a custom partition
1546 - FAT(File Allocation Table) filesystem write function support:
1549 Define this to enable support for saving memory data as a
1550 file in FAT formatted partition.
1552 This will also enable the command "fatwrite" enabling the
1553 user to write files to FAT.
1555 CBFS (Coreboot Filesystem) support
1558 Define this to enable support for reading from a Coreboot
1559 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1565 Define this to enable standard (PC-Style) keyboard
1569 Standard PC keyboard driver with US (is default) and
1570 GERMAN key layout (switch via environment 'keymap=de') support.
1571 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1572 for cfb_console. Supports cursor blinking.
1575 Enables a Chrome OS keyboard using the CROS_EC interface.
1576 This uses CROS_EC to communicate with a second microcontroller
1577 which provides key scans on request.
1582 Define this to enable video support (for output to
1585 CONFIG_VIDEO_CT69000
1587 Enable Chips & Technologies 69000 Video chip
1589 CONFIG_VIDEO_SMI_LYNXEM
1590 Enable Silicon Motion SMI 712/710/810 Video chip. The
1591 video output is selected via environment 'videoout'
1592 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1595 For the CT69000 and SMI_LYNXEM drivers, videomode is
1596 selected via environment 'videomode'. Two different ways
1598 - "videomode=num" 'num' is a standard LiLo mode numbers.
1599 Following standard modes are supported (* is default):
1601 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1602 -------------+---------------------------------------------
1603 8 bits | 0x301* 0x303 0x305 0x161 0x307
1604 15 bits | 0x310 0x313 0x316 0x162 0x319
1605 16 bits | 0x311 0x314 0x317 0x163 0x31A
1606 24 bits | 0x312 0x315 0x318 ? 0x31B
1607 -------------+---------------------------------------------
1608 (i.e. setenv videomode 317; saveenv; reset;)
1610 - "videomode=bootargs" all the video parameters are parsed
1611 from the bootargs. (See drivers/video/videomodes.c)
1614 CONFIG_VIDEO_SED13806
1615 Enable Epson SED13806 driver. This driver supports 8bpp
1616 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1617 or CONFIG_VIDEO_SED13806_16BPP
1620 Enable the Freescale DIU video driver. Reference boards for
1621 SOCs that have a DIU should define this macro to enable DIU
1622 support, and should also define these other macros:
1628 CONFIG_VIDEO_SW_CURSOR
1629 CONFIG_VGA_AS_SINGLE_DEVICE
1631 CONFIG_VIDEO_BMP_LOGO
1633 The DIU driver will look for the 'video-mode' environment
1634 variable, and if defined, enable the DIU as a console during
1635 boot. See the documentation file README.video for a
1636 description of this variable.
1640 Enable the VGA video / BIOS for x86. The alternative if you
1641 are using coreboot is to use the coreboot frame buffer
1648 Define this to enable a custom keyboard support.
1649 This simply calls drv_keyboard_init() which must be
1650 defined in your board-specific files.
1651 The only board using this so far is RBC823.
1653 - LCD Support: CONFIG_LCD
1655 Define this to enable LCD support (for output to LCD
1656 display); also select one of the supported displays
1657 by defining one of these:
1661 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1663 CONFIG_NEC_NL6448AC33:
1665 NEC NL6448AC33-18. Active, color, single scan.
1667 CONFIG_NEC_NL6448BC20
1669 NEC NL6448BC20-08. 6.5", 640x480.
1670 Active, color, single scan.
1672 CONFIG_NEC_NL6448BC33_54
1674 NEC NL6448BC33-54. 10.4", 640x480.
1675 Active, color, single scan.
1679 Sharp 320x240. Active, color, single scan.
1680 It isn't 16x9, and I am not sure what it is.
1682 CONFIG_SHARP_LQ64D341
1684 Sharp LQ64D341 display, 640x480.
1685 Active, color, single scan.
1689 HLD1045 display, 640x480.
1690 Active, color, single scan.
1694 Optrex CBL50840-2 NF-FW 99 22 M5
1696 Hitachi LMG6912RPFC-00T
1700 320x240. Black & white.
1702 Normally display is black on white background; define
1703 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1705 CONFIG_LCD_ALIGNMENT
1707 Normally the LCD is page-aligned (tyically 4KB). If this is
1708 defined then the LCD will be aligned to this value instead.
1709 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1710 here, since it is cheaper to change data cache settings on
1711 a per-section basis.
1713 CONFIG_CONSOLE_SCROLL_LINES
1715 When the console need to be scrolled, this is the number of
1716 lines to scroll by. It defaults to 1. Increasing this makes
1717 the console jump but can help speed up operation when scrolling
1722 Support drawing of RLE8-compressed bitmaps on the LCD.
1726 Enables an 'i2c edid' command which can read EDID
1727 information over I2C from an attached LCD display.
1729 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1731 If this option is set, the environment is checked for
1732 a variable "splashimage". If found, the usual display
1733 of logo, copyright and system information on the LCD
1734 is suppressed and the BMP image at the address
1735 specified in "splashimage" is loaded instead. The
1736 console is redirected to the "nulldev", too. This
1737 allows for a "silent" boot where a splash screen is
1738 loaded very quickly after power-on.
1740 CONFIG_SPLASHIMAGE_GUARD
1742 If this option is set, then U-Boot will prevent the environment
1743 variable "splashimage" from being set to a problematic address
1744 (see README.displaying-bmps).
1745 This option is useful for targets where, due to alignment
1746 restrictions, an improperly aligned BMP image will cause a data
1747 abort. If you think you will not have problems with unaligned
1748 accesses (for example because your toolchain prevents them)
1749 there is no need to set this option.
1751 CONFIG_SPLASH_SCREEN_ALIGN
1753 If this option is set the splash image can be freely positioned
1754 on the screen. Environment variable "splashpos" specifies the
1755 position as "x,y". If a positive number is given it is used as
1756 number of pixel from left/top. If a negative number is given it
1757 is used as number of pixel from right/bottom. You can also
1758 specify 'm' for centering the image.
1761 setenv splashpos m,m
1762 => image at center of screen
1764 setenv splashpos 30,20
1765 => image at x = 30 and y = 20
1767 setenv splashpos -10,m
1768 => vertically centered image
1769 at x = dspWidth - bmpWidth - 9
1771 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1773 If this option is set, additionally to standard BMP
1774 images, gzipped BMP images can be displayed via the
1775 splashscreen support or the bmp command.
1777 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1779 If this option is set, 8-bit RLE compressed BMP images
1780 can be displayed via the splashscreen support or the
1783 - Do compresssing for memory range:
1786 If this option is set, it would use zlib deflate method
1787 to compress the specified memory at its best effort.
1789 - Compression support:
1792 Enabled by default to support gzip compressed images.
1796 If this option is set, support for bzip2 compressed
1797 images is included. If not, only uncompressed and gzip
1798 compressed images are supported.
1800 NOTE: the bzip2 algorithm requires a lot of RAM, so
1801 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1806 If this option is set, support for lzma compressed
1809 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1810 requires an amount of dynamic memory that is given by the
1813 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1815 Where lc and lp stand for, respectively, Literal context bits
1816 and Literal pos bits.
1818 This value is upper-bounded by 14MB in the worst case. Anyway,
1819 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1820 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1821 a very small buffer.
1823 Use the lzmainfo tool to determinate the lc and lp values and
1824 then calculate the amount of needed dynamic memory (ensuring
1825 the appropriate CONFIG_SYS_MALLOC_LEN value).
1829 If this option is set, support for LZO compressed images
1835 The address of PHY on MII bus.
1837 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1839 The clock frequency of the MII bus
1843 If this option is set, support for speed/duplex
1844 detection of gigabit PHY is included.
1846 CONFIG_PHY_RESET_DELAY
1848 Some PHY like Intel LXT971A need extra delay after
1849 reset before any MII register access is possible.
1850 For such PHY, set this option to the usec delay
1851 required. (minimum 300usec for LXT971A)
1853 CONFIG_PHY_CMD_DELAY (ppc4xx)
1855 Some PHY like Intel LXT971A need extra delay after
1856 command issued before MII status register can be read
1866 Define a default value for Ethernet address to use
1867 for the respective Ethernet interface, in case this
1868 is not determined automatically.
1873 Define a default value for the IP address to use for
1874 the default Ethernet interface, in case this is not
1875 determined through e.g. bootp.
1876 (Environment variable "ipaddr")
1878 - Server IP address:
1881 Defines a default value for the IP address of a TFTP
1882 server to contact when using the "tftboot" command.
1883 (Environment variable "serverip")
1885 CONFIG_KEEP_SERVERADDR
1887 Keeps the server's MAC address, in the env 'serveraddr'
1888 for passing to bootargs (like Linux's netconsole option)
1890 - Gateway IP address:
1893 Defines a default value for the IP address of the
1894 default router where packets to other networks are
1896 (Environment variable "gatewayip")
1901 Defines a default value for the subnet mask (or
1902 routing prefix) which is used to determine if an IP
1903 address belongs to the local subnet or needs to be
1904 forwarded through a router.
1905 (Environment variable "netmask")
1907 - Multicast TFTP Mode:
1910 Defines whether you want to support multicast TFTP as per
1911 rfc-2090; for example to work with atftp. Lets lots of targets
1912 tftp down the same boot image concurrently. Note: the Ethernet
1913 driver in use must provide a function: mcast() to join/leave a
1916 - BOOTP Recovery Mode:
1917 CONFIG_BOOTP_RANDOM_DELAY
1919 If you have many targets in a network that try to
1920 boot using BOOTP, you may want to avoid that all
1921 systems send out BOOTP requests at precisely the same
1922 moment (which would happen for instance at recovery
1923 from a power failure, when all systems will try to
1924 boot, thus flooding the BOOTP server. Defining
1925 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1926 inserted before sending out BOOTP requests. The
1927 following delays are inserted then:
1929 1st BOOTP request: delay 0 ... 1 sec
1930 2nd BOOTP request: delay 0 ... 2 sec
1931 3rd BOOTP request: delay 0 ... 4 sec
1933 BOOTP requests: delay 0 ... 8 sec
1935 - DHCP Advanced Options:
1936 You can fine tune the DHCP functionality by defining
1937 CONFIG_BOOTP_* symbols:
1939 CONFIG_BOOTP_SUBNETMASK
1940 CONFIG_BOOTP_GATEWAY
1941 CONFIG_BOOTP_HOSTNAME
1942 CONFIG_BOOTP_NISDOMAIN
1943 CONFIG_BOOTP_BOOTPATH
1944 CONFIG_BOOTP_BOOTFILESIZE
1947 CONFIG_BOOTP_SEND_HOSTNAME
1948 CONFIG_BOOTP_NTPSERVER
1949 CONFIG_BOOTP_TIMEOFFSET
1950 CONFIG_BOOTP_VENDOREX
1951 CONFIG_BOOTP_MAY_FAIL
1953 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1954 environment variable, not the BOOTP server.
1956 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1957 after the configured retry count, the call will fail
1958 instead of starting over. This can be used to fail over
1959 to Link-local IP address configuration if the DHCP server
1962 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1963 serverip from a DHCP server, it is possible that more
1964 than one DNS serverip is offered to the client.
1965 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1966 serverip will be stored in the additional environment
1967 variable "dnsip2". The first DNS serverip is always
1968 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1971 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1972 to do a dynamic update of a DNS server. To do this, they
1973 need the hostname of the DHCP requester.
1974 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1975 of the "hostname" environment variable is passed as
1976 option 12 to the DHCP server.
1978 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1980 A 32bit value in microseconds for a delay between
1981 receiving a "DHCP Offer" and sending the "DHCP Request".
1982 This fixes a problem with certain DHCP servers that don't
1983 respond 100% of the time to a "DHCP request". E.g. On an
1984 AT91RM9200 processor running at 180MHz, this delay needed
1985 to be *at least* 15,000 usec before a Windows Server 2003
1986 DHCP server would reply 100% of the time. I recommend at
1987 least 50,000 usec to be safe. The alternative is to hope
1988 that one of the retries will be successful but note that
1989 the DHCP timeout and retry process takes a longer than
1992 - Link-local IP address negotiation:
1993 Negotiate with other link-local clients on the local network
1994 for an address that doesn't require explicit configuration.
1995 This is especially useful if a DHCP server cannot be guaranteed
1996 to exist in all environments that the device must operate.
1998 See doc/README.link-local for more information.
2001 CONFIG_CDP_DEVICE_ID
2003 The device id used in CDP trigger frames.
2005 CONFIG_CDP_DEVICE_ID_PREFIX
2007 A two character string which is prefixed to the MAC address
2012 A printf format string which contains the ascii name of
2013 the port. Normally is set to "eth%d" which sets
2014 eth0 for the first Ethernet, eth1 for the second etc.
2016 CONFIG_CDP_CAPABILITIES
2018 A 32bit integer which indicates the device capabilities;
2019 0x00000010 for a normal host which does not forwards.
2023 An ascii string containing the version of the software.
2027 An ascii string containing the name of the platform.
2031 A 32bit integer sent on the trigger.
2033 CONFIG_CDP_POWER_CONSUMPTION
2035 A 16bit integer containing the power consumption of the
2036 device in .1 of milliwatts.
2038 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2040 A byte containing the id of the VLAN.
2042 - Status LED: CONFIG_STATUS_LED
2044 Several configurations allow to display the current
2045 status using a LED. For instance, the LED will blink
2046 fast while running U-Boot code, stop blinking as
2047 soon as a reply to a BOOTP request was received, and
2048 start blinking slow once the Linux kernel is running
2049 (supported by a status LED driver in the Linux
2050 kernel). Defining CONFIG_STATUS_LED enables this
2056 The status LED can be connected to a GPIO pin.
2057 In such cases, the gpio_led driver can be used as a
2058 status LED backend implementation. Define CONFIG_GPIO_LED
2059 to include the gpio_led driver in the U-Boot binary.
2061 CONFIG_GPIO_LED_INVERTED_TABLE
2062 Some GPIO connected LEDs may have inverted polarity in which
2063 case the GPIO high value corresponds to LED off state and
2064 GPIO low value corresponds to LED on state.
2065 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2066 with a list of GPIO LEDs that have inverted polarity.
2068 - CAN Support: CONFIG_CAN_DRIVER
2070 Defining CONFIG_CAN_DRIVER enables CAN driver support
2071 on those systems that support this (optional)
2072 feature, like the TQM8xxL modules.
2074 - I2C Support: CONFIG_SYS_I2C
2076 This enable the NEW i2c subsystem, and will allow you to use
2077 i2c commands at the u-boot command line (as long as you set
2078 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2079 based realtime clock chips or other i2c devices. See
2080 common/cmd_i2c.c for a description of the command line
2083 ported i2c driver to the new framework:
2084 - drivers/i2c/soft_i2c.c:
2085 - activate first bus with CONFIG_SYS_I2C_SOFT define
2086 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2087 for defining speed and slave address
2088 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2089 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2090 for defining speed and slave address
2091 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2092 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2093 for defining speed and slave address
2094 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2095 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2096 for defining speed and slave address
2098 - drivers/i2c/fsl_i2c.c:
2099 - activate i2c driver with CONFIG_SYS_I2C_FSL
2100 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2101 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2102 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2104 - If your board supports a second fsl i2c bus, define
2105 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2106 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2107 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2110 - drivers/i2c/tegra_i2c.c:
2111 - activate this driver with CONFIG_SYS_I2C_TEGRA
2112 - This driver adds 4 i2c buses with a fix speed from
2113 100000 and the slave addr 0!
2115 - drivers/i2c/ppc4xx_i2c.c
2116 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2117 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2118 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2120 - drivers/i2c/i2c_mxc.c
2121 - activate this driver with CONFIG_SYS_I2C_MXC
2122 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2123 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2124 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2125 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2126 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2127 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2128 If thoses defines are not set, default value is 100000
2129 for speed, and 0 for slave.
2131 - drivers/i2c/rcar_i2c.c:
2132 - activate this driver with CONFIG_SYS_I2C_RCAR
2133 - This driver adds 4 i2c buses
2135 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2136 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2137 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2138 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2139 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2140 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2141 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2142 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2143 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2145 - drivers/i2c/sh_i2c.c:
2146 - activate this driver with CONFIG_SYS_I2C_SH
2147 - This driver adds from 2 to 5 i2c buses
2149 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2150 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2151 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2152 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2153 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2154 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2155 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2156 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2157 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2158 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2159 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2160 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2161 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2163 - drivers/i2c/omap24xx_i2c.c
2164 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2165 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2166 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2167 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2168 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2169 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2170 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2171 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2172 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2173 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2174 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2176 - drivers/i2c/zynq_i2c.c
2177 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2178 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2179 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2181 - drivers/i2c/s3c24x0_i2c.c:
2182 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2183 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2184 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2185 with a fix speed from 100000 and the slave addr 0!
2189 CONFIG_SYS_NUM_I2C_BUSES
2190 Hold the number of i2c busses you want to use. If you
2191 don't use/have i2c muxes on your i2c bus, this
2192 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2195 CONFIG_SYS_I2C_DIRECT_BUS
2196 define this, if you don't use i2c muxes on your hardware.
2197 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2200 CONFIG_SYS_I2C_MAX_HOPS
2201 define how many muxes are maximal consecutively connected
2202 on one i2c bus. If you not use i2c muxes, omit this
2205 CONFIG_SYS_I2C_BUSES
2206 hold a list of busses you want to use, only used if
2207 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2208 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2209 CONFIG_SYS_NUM_I2C_BUSES = 9:
2211 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2212 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2213 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2214 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2215 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2216 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2217 {1, {I2C_NULL_HOP}}, \
2218 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2219 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2223 bus 0 on adapter 0 without a mux
2224 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2225 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2226 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2227 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2228 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2229 bus 6 on adapter 1 without a mux
2230 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2231 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2233 If you do not have i2c muxes on your board, omit this define.
2235 - Legacy I2C Support: CONFIG_HARD_I2C
2237 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2238 provides the following compelling advantages:
2240 - more than one i2c adapter is usable
2241 - approved multibus support
2242 - better i2c mux support
2244 ** Please consider updating your I2C driver now. **
2246 These enable legacy I2C serial bus commands. Defining
2247 CONFIG_HARD_I2C will include the appropriate I2C driver
2248 for the selected CPU.
2250 This will allow you to use i2c commands at the u-boot
2251 command line (as long as you set CONFIG_CMD_I2C in
2252 CONFIG_COMMANDS) and communicate with i2c based realtime
2253 clock chips. See common/cmd_i2c.c for a description of the
2254 command line interface.
2256 CONFIG_HARD_I2C selects a hardware I2C controller.
2258 There are several other quantities that must also be
2259 defined when you define CONFIG_HARD_I2C.
2261 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2262 to be the frequency (in Hz) at which you wish your i2c bus
2263 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2264 the CPU's i2c node address).
2266 Now, the u-boot i2c code for the mpc8xx
2267 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2268 and so its address should therefore be cleared to 0 (See,
2269 eg, MPC823e User's Manual p.16-473). So, set
2270 CONFIG_SYS_I2C_SLAVE to 0.
2272 CONFIG_SYS_I2C_INIT_MPC5XXX
2274 When a board is reset during an i2c bus transfer
2275 chips might think that the current transfer is still
2276 in progress. Reset the slave devices by sending start
2277 commands until the slave device responds.
2279 That's all that's required for CONFIG_HARD_I2C.
2281 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2282 then the following macros need to be defined (examples are
2283 from include/configs/lwmon.h):
2287 (Optional). Any commands necessary to enable the I2C
2288 controller or configure ports.
2290 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2294 (Only for MPC8260 CPU). The I/O port to use (the code
2295 assumes both bits are on the same port). Valid values
2296 are 0..3 for ports A..D.
2300 The code necessary to make the I2C data line active
2301 (driven). If the data line is open collector, this
2304 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2308 The code necessary to make the I2C data line tri-stated
2309 (inactive). If the data line is open collector, this
2312 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2316 Code that returns true if the I2C data line is high,
2319 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2323 If <bit> is true, sets the I2C data line high. If it
2324 is false, it clears it (low).
2326 eg: #define I2C_SDA(bit) \
2327 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2328 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2332 If <bit> is true, sets the I2C clock line high. If it
2333 is false, it clears it (low).
2335 eg: #define I2C_SCL(bit) \
2336 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2337 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2341 This delay is invoked four times per clock cycle so this
2342 controls the rate of data transfer. The data rate thus
2343 is 1 / (I2C_DELAY * 4). Often defined to be something
2346 #define I2C_DELAY udelay(2)
2348 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2350 If your arch supports the generic GPIO framework (asm/gpio.h),
2351 then you may alternatively define the two GPIOs that are to be
2352 used as SCL / SDA. Any of the previous I2C_xxx macros will
2353 have GPIO-based defaults assigned to them as appropriate.
2355 You should define these to the GPIO value as given directly to
2356 the generic GPIO functions.
2358 CONFIG_SYS_I2C_INIT_BOARD
2360 When a board is reset during an i2c bus transfer
2361 chips might think that the current transfer is still
2362 in progress. On some boards it is possible to access
2363 the i2c SCLK line directly, either by using the
2364 processor pin as a GPIO or by having a second pin
2365 connected to the bus. If this option is defined a
2366 custom i2c_init_board() routine in boards/xxx/board.c
2367 is run early in the boot sequence.
2369 CONFIG_SYS_I2C_BOARD_LATE_INIT
2371 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2372 defined a custom i2c_board_late_init() routine in
2373 boards/xxx/board.c is run AFTER the operations in i2c_init()
2374 is completed. This callpoint can be used to unreset i2c bus
2375 using CPU i2c controller register accesses for CPUs whose i2c
2376 controller provide such a method. It is called at the end of
2377 i2c_init() to allow i2c_init operations to setup the i2c bus
2378 controller on the CPU (e.g. setting bus speed & slave address).
2380 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2382 This option enables configuration of bi_iic_fast[] flags
2383 in u-boot bd_info structure based on u-boot environment
2384 variable "i2cfast". (see also i2cfast)
2386 CONFIG_I2C_MULTI_BUS
2388 This option allows the use of multiple I2C buses, each of which
2389 must have a controller. At any point in time, only one bus is
2390 active. To switch to a different bus, use the 'i2c dev' command.
2391 Note that bus numbering is zero-based.
2393 CONFIG_SYS_I2C_NOPROBES
2395 This option specifies a list of I2C devices that will be skipped
2396 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2397 is set, specify a list of bus-device pairs. Otherwise, specify
2398 a 1D array of device addresses
2401 #undef CONFIG_I2C_MULTI_BUS
2402 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2404 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2406 #define CONFIG_I2C_MULTI_BUS
2407 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2409 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2411 CONFIG_SYS_SPD_BUS_NUM
2413 If defined, then this indicates the I2C bus number for DDR SPD.
2414 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2416 CONFIG_SYS_RTC_BUS_NUM
2418 If defined, then this indicates the I2C bus number for the RTC.
2419 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2421 CONFIG_SYS_DTT_BUS_NUM
2423 If defined, then this indicates the I2C bus number for the DTT.
2424 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2426 CONFIG_SYS_I2C_DTT_ADDR:
2428 If defined, specifies the I2C address of the DTT device.
2429 If not defined, then U-Boot uses predefined value for
2430 specified DTT device.
2432 CONFIG_SOFT_I2C_READ_REPEATED_START
2434 defining this will force the i2c_read() function in
2435 the soft_i2c driver to perform an I2C repeated start
2436 between writing the address pointer and reading the
2437 data. If this define is omitted the default behaviour
2438 of doing a stop-start sequence will be used. Most I2C
2439 devices can use either method, but some require one or
2442 - SPI Support: CONFIG_SPI
2444 Enables SPI driver (so far only tested with
2445 SPI EEPROM, also an instance works with Crystal A/D and
2446 D/As on the SACSng board)
2450 Enables the driver for SPI controller on SuperH. Currently
2451 only SH7757 is supported.
2455 Enables extended (16-bit) SPI EEPROM addressing.
2456 (symmetrical to CONFIG_I2C_X)
2460 Enables a software (bit-bang) SPI driver rather than
2461 using hardware support. This is a general purpose
2462 driver that only requires three general I/O port pins
2463 (two outputs, one input) to function. If this is
2464 defined, the board configuration must define several
2465 SPI configuration items (port pins to use, etc). For
2466 an example, see include/configs/sacsng.h.
2470 Enables a hardware SPI driver for general-purpose reads
2471 and writes. As with CONFIG_SOFT_SPI, the board configuration
2472 must define a list of chip-select function pointers.
2473 Currently supported on some MPC8xxx processors. For an
2474 example, see include/configs/mpc8349emds.h.
2478 Enables the driver for the SPI controllers on i.MX and MXC
2479 SoCs. Currently i.MX31/35/51 are supported.
2481 - FPGA Support: CONFIG_FPGA
2483 Enables FPGA subsystem.
2485 CONFIG_FPGA_<vendor>
2487 Enables support for specific chip vendors.
2490 CONFIG_FPGA_<family>
2492 Enables support for FPGA family.
2493 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2497 Specify the number of FPGA devices to support.
2499 CONFIG_SYS_FPGA_PROG_FEEDBACK
2501 Enable printing of hash marks during FPGA configuration.
2503 CONFIG_SYS_FPGA_CHECK_BUSY
2505 Enable checks on FPGA configuration interface busy
2506 status by the configuration function. This option
2507 will require a board or device specific function to
2512 If defined, a function that provides delays in the FPGA
2513 configuration driver.
2515 CONFIG_SYS_FPGA_CHECK_CTRLC
2516 Allow Control-C to interrupt FPGA configuration
2518 CONFIG_SYS_FPGA_CHECK_ERROR
2520 Check for configuration errors during FPGA bitfile
2521 loading. For example, abort during Virtex II
2522 configuration if the INIT_B line goes low (which
2523 indicated a CRC error).
2525 CONFIG_SYS_FPGA_WAIT_INIT
2527 Maximum time to wait for the INIT_B line to deassert
2528 after PROB_B has been deasserted during a Virtex II
2529 FPGA configuration sequence. The default time is 500
2532 CONFIG_SYS_FPGA_WAIT_BUSY
2534 Maximum time to wait for BUSY to deassert during
2535 Virtex II FPGA configuration. The default is 5 ms.
2537 CONFIG_SYS_FPGA_WAIT_CONFIG
2539 Time to wait after FPGA configuration. The default is
2542 - Configuration Management:
2545 If defined, this string will be added to the U-Boot
2546 version information (U_BOOT_VERSION)
2548 - Vendor Parameter Protection:
2550 U-Boot considers the values of the environment
2551 variables "serial#" (Board Serial Number) and
2552 "ethaddr" (Ethernet Address) to be parameters that
2553 are set once by the board vendor / manufacturer, and
2554 protects these variables from casual modification by
2555 the user. Once set, these variables are read-only,
2556 and write or delete attempts are rejected. You can
2557 change this behaviour:
2559 If CONFIG_ENV_OVERWRITE is #defined in your config
2560 file, the write protection for vendor parameters is
2561 completely disabled. Anybody can change or delete
2564 Alternatively, if you #define _both_ CONFIG_ETHADDR
2565 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2566 Ethernet address is installed in the environment,
2567 which can be changed exactly ONCE by the user. [The
2568 serial# is unaffected by this, i. e. it remains
2571 The same can be accomplished in a more flexible way
2572 for any variable by configuring the type of access
2573 to allow for those variables in the ".flags" variable
2574 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2579 Define this variable to enable the reservation of
2580 "protected RAM", i. e. RAM which is not overwritten
2581 by U-Boot. Define CONFIG_PRAM to hold the number of
2582 kB you want to reserve for pRAM. You can overwrite
2583 this default value by defining an environment
2584 variable "pram" to the number of kB you want to
2585 reserve. Note that the board info structure will
2586 still show the full amount of RAM. If pRAM is
2587 reserved, a new environment variable "mem" will
2588 automatically be defined to hold the amount of
2589 remaining RAM in a form that can be passed as boot
2590 argument to Linux, for instance like that:
2592 setenv bootargs ... mem=\${mem}
2595 This way you can tell Linux not to use this memory,
2596 either, which results in a memory region that will
2597 not be affected by reboots.
2599 *WARNING* If your board configuration uses automatic
2600 detection of the RAM size, you must make sure that
2601 this memory test is non-destructive. So far, the
2602 following board configurations are known to be
2605 IVMS8, IVML24, SPD8xx, TQM8xxL,
2606 HERMES, IP860, RPXlite, LWMON,
2609 - Access to physical memory region (> 4GB)
2610 Some basic support is provided for operations on memory not
2611 normally accessible to U-Boot - e.g. some architectures
2612 support access to more than 4GB of memory on 32-bit
2613 machines using physical address extension or similar.
2614 Define CONFIG_PHYSMEM to access this basic support, which
2615 currently only supports clearing the memory.
2620 Define this variable to stop the system in case of a
2621 fatal error, so that you have to reset it manually.
2622 This is probably NOT a good idea for an embedded
2623 system where you want the system to reboot
2624 automatically as fast as possible, but it may be
2625 useful during development since you can try to debug
2626 the conditions that lead to the situation.
2628 CONFIG_NET_RETRY_COUNT
2630 This variable defines the number of retries for
2631 network operations like ARP, RARP, TFTP, or BOOTP
2632 before giving up the operation. If not defined, a
2633 default value of 5 is used.
2637 Timeout waiting for an ARP reply in milliseconds.
2641 Timeout in milliseconds used in NFS protocol.
2642 If you encounter "ERROR: Cannot umount" in nfs command,
2643 try longer timeout such as
2644 #define CONFIG_NFS_TIMEOUT 10000UL
2646 - Command Interpreter:
2647 CONFIG_AUTO_COMPLETE
2649 Enable auto completion of commands using TAB.
2651 Note that this feature has NOT been implemented yet
2652 for the "hush" shell.
2655 CONFIG_SYS_HUSH_PARSER
2657 Define this variable to enable the "hush" shell (from
2658 Busybox) as command line interpreter, thus enabling
2659 powerful command line syntax like
2660 if...then...else...fi conditionals or `&&' and '||'
2661 constructs ("shell scripts").
2663 If undefined, you get the old, much simpler behaviour
2664 with a somewhat smaller memory footprint.
2667 CONFIG_SYS_PROMPT_HUSH_PS2
2669 This defines the secondary prompt string, which is
2670 printed when the command interpreter needs more input
2671 to complete a command. Usually "> ".
2675 In the current implementation, the local variables
2676 space and global environment variables space are
2677 separated. Local variables are those you define by
2678 simply typing `name=value'. To access a local
2679 variable later on, you have write `$name' or
2680 `${name}'; to execute the contents of a variable
2681 directly type `$name' at the command prompt.
2683 Global environment variables are those you use
2684 setenv/printenv to work with. To run a command stored
2685 in such a variable, you need to use the run command,
2686 and you must not use the '$' sign to access them.
2688 To store commands and special characters in a
2689 variable, please use double quotation marks
2690 surrounding the whole text of the variable, instead
2691 of the backslashes before semicolons and special
2694 - Commandline Editing and History:
2695 CONFIG_CMDLINE_EDITING
2697 Enable editing and History functions for interactive
2698 commandline input operations
2700 - Default Environment:
2701 CONFIG_EXTRA_ENV_SETTINGS
2703 Define this to contain any number of null terminated
2704 strings (variable = value pairs) that will be part of
2705 the default environment compiled into the boot image.
2707 For example, place something like this in your
2708 board's config file:
2710 #define CONFIG_EXTRA_ENV_SETTINGS \
2714 Warning: This method is based on knowledge about the
2715 internal format how the environment is stored by the
2716 U-Boot code. This is NOT an official, exported
2717 interface! Although it is unlikely that this format
2718 will change soon, there is no guarantee either.
2719 You better know what you are doing here.
2721 Note: overly (ab)use of the default environment is
2722 discouraged. Make sure to check other ways to preset
2723 the environment like the "source" command or the
2726 CONFIG_ENV_VARS_UBOOT_CONFIG
2728 Define this in order to add variables describing the
2729 U-Boot build configuration to the default environment.
2730 These will be named arch, cpu, board, vendor, and soc.
2732 Enabling this option will cause the following to be defined:
2740 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2742 Define this in order to add variables describing certain
2743 run-time determined information about the hardware to the
2744 environment. These will be named board_name, board_rev.
2746 CONFIG_DELAY_ENVIRONMENT
2748 Normally the environment is loaded when the board is
2749 intialised so that it is available to U-Boot. This inhibits
2750 that so that the environment is not available until
2751 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2752 this is instead controlled by the value of
2753 /config/load-environment.
2755 - DataFlash Support:
2756 CONFIG_HAS_DATAFLASH
2758 Defining this option enables DataFlash features and
2759 allows to read/write in Dataflash via the standard
2762 - Serial Flash support
2765 Defining this option enables SPI flash commands
2766 'sf probe/read/write/erase/update'.
2768 Usage requires an initial 'probe' to define the serial
2769 flash parameters, followed by read/write/erase/update
2772 The following defaults may be provided by the platform
2773 to handle the common case when only a single serial
2774 flash is present on the system.
2776 CONFIG_SF_DEFAULT_BUS Bus identifier
2777 CONFIG_SF_DEFAULT_CS Chip-select
2778 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2779 CONFIG_SF_DEFAULT_SPEED in Hz
2783 Define this option to include a destructive SPI flash
2786 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2788 Define this option to use the Bank addr/Extended addr
2789 support on SPI flashes which has size > 16Mbytes.
2791 CONFIG_SF_DUAL_FLASH Dual flash memories
2793 Define this option to use dual flash support where two flash
2794 memories can be connected with a given cs line.
2795 currently Xilinx Zynq qspi support these type of connections.
2797 - SystemACE Support:
2800 Adding this option adds support for Xilinx SystemACE
2801 chips attached via some sort of local bus. The address
2802 of the chip must also be defined in the
2803 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2805 #define CONFIG_SYSTEMACE
2806 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2808 When SystemACE support is added, the "ace" device type
2809 becomes available to the fat commands, i.e. fatls.
2811 - TFTP Fixed UDP Port:
2814 If this is defined, the environment variable tftpsrcp
2815 is used to supply the TFTP UDP source port value.
2816 If tftpsrcp isn't defined, the normal pseudo-random port
2817 number generator is used.
2819 Also, the environment variable tftpdstp is used to supply
2820 the TFTP UDP destination port value. If tftpdstp isn't
2821 defined, the normal port 69 is used.
2823 The purpose for tftpsrcp is to allow a TFTP server to
2824 blindly start the TFTP transfer using the pre-configured
2825 target IP address and UDP port. This has the effect of
2826 "punching through" the (Windows XP) firewall, allowing
2827 the remainder of the TFTP transfer to proceed normally.
2828 A better solution is to properly configure the firewall,
2829 but sometimes that is not allowed.
2834 This enables a generic 'hash' command which can produce
2835 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2839 Enable the hash verify command (hash -v). This adds to code
2842 CONFIG_SHA1 - support SHA1 hashing
2843 CONFIG_SHA256 - support SHA256 hashing
2845 Note: There is also a sha1sum command, which should perhaps
2846 be deprecated in favour of 'hash sha1'.
2848 - Freescale i.MX specific commands:
2849 CONFIG_CMD_HDMIDETECT
2850 This enables 'hdmidet' command which returns true if an
2851 HDMI monitor is detected. This command is i.MX 6 specific.
2854 This enables the 'bmode' (bootmode) command for forcing
2855 a boot from specific media.
2857 This is useful for forcing the ROM's usb downloader to
2858 activate upon a watchdog reset which is nice when iterating
2859 on U-Boot. Using the reset button or running bmode normal
2860 will set it back to normal. This command currently
2861 supports i.MX53 and i.MX6.
2866 This enables the RSA algorithm used for FIT image verification
2867 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2869 The signing part is build into mkimage regardless of this
2872 - bootcount support:
2873 CONFIG_BOOTCOUNT_LIMIT
2875 This enables the bootcounter support, see:
2876 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2879 enable special bootcounter support on at91sam9xe based boards.
2881 enable special bootcounter support on blackfin based boards.
2883 enable special bootcounter support on da850 based boards.
2884 CONFIG_BOOTCOUNT_RAM
2885 enable support for the bootcounter in RAM
2886 CONFIG_BOOTCOUNT_I2C
2887 enable support for the bootcounter on an i2c (like RTC) device.
2888 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2889 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2891 CONFIG_BOOTCOUNT_ALEN = address len
2893 - Show boot progress:
2894 CONFIG_SHOW_BOOT_PROGRESS
2896 Defining this option allows to add some board-
2897 specific code (calling a user-provided function
2898 "show_boot_progress(int)") that enables you to show
2899 the system's boot progress on some display (for
2900 example, some LED's) on your board. At the moment,
2901 the following checkpoints are implemented:
2903 - Detailed boot stage timing
2905 Define this option to get detailed timing of each stage
2906 of the boot process.
2908 CONFIG_BOOTSTAGE_USER_COUNT
2909 This is the number of available user bootstage records.
2910 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2911 a new ID will be allocated from this stash. If you exceed
2912 the limit, recording will stop.
2914 CONFIG_BOOTSTAGE_REPORT
2915 Define this to print a report before boot, similar to this:
2917 Timer summary in microseconds:
2920 3,575,678 3,575,678 board_init_f start
2921 3,575,695 17 arch_cpu_init A9
2922 3,575,777 82 arch_cpu_init done
2923 3,659,598 83,821 board_init_r start
2924 3,910,375 250,777 main_loop
2925 29,916,167 26,005,792 bootm_start
2926 30,361,327 445,160 start_kernel
2928 CONFIG_CMD_BOOTSTAGE
2929 Add a 'bootstage' command which supports printing a report
2930 and un/stashing of bootstage data.
2932 CONFIG_BOOTSTAGE_FDT
2933 Stash the bootstage information in the FDT. A root 'bootstage'
2934 node is created with each bootstage id as a child. Each child
2935 has a 'name' property and either 'mark' containing the
2936 mark time in microsecond, or 'accum' containing the
2937 accumulated time for that bootstage id in microseconds.
2942 name = "board_init_f";
2951 Code in the Linux kernel can find this in /proc/devicetree.
2953 Legacy uImage format:
2956 1 common/cmd_bootm.c before attempting to boot an image
2957 -1 common/cmd_bootm.c Image header has bad magic number
2958 2 common/cmd_bootm.c Image header has correct magic number
2959 -2 common/cmd_bootm.c Image header has bad checksum
2960 3 common/cmd_bootm.c Image header has correct checksum
2961 -3 common/cmd_bootm.c Image data has bad checksum
2962 4 common/cmd_bootm.c Image data has correct checksum
2963 -4 common/cmd_bootm.c Image is for unsupported architecture
2964 5 common/cmd_bootm.c Architecture check OK
2965 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2966 6 common/cmd_bootm.c Image Type check OK
2967 -6 common/cmd_bootm.c gunzip uncompression error
2968 -7 common/cmd_bootm.c Unimplemented compression type
2969 7 common/cmd_bootm.c Uncompression OK
2970 8 common/cmd_bootm.c No uncompress/copy overwrite error
2971 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2973 9 common/image.c Start initial ramdisk verification
2974 -10 common/image.c Ramdisk header has bad magic number
2975 -11 common/image.c Ramdisk header has bad checksum
2976 10 common/image.c Ramdisk header is OK
2977 -12 common/image.c Ramdisk data has bad checksum
2978 11 common/image.c Ramdisk data has correct checksum
2979 12 common/image.c Ramdisk verification complete, start loading
2980 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2981 13 common/image.c Start multifile image verification
2982 14 common/image.c No initial ramdisk, no multifile, continue.
2984 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2986 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2987 -31 post/post.c POST test failed, detected by post_output_backlog()
2988 -32 post/post.c POST test failed, detected by post_run_single()
2990 34 common/cmd_doc.c before loading a Image from a DOC device
2991 -35 common/cmd_doc.c Bad usage of "doc" command
2992 35 common/cmd_doc.c correct usage of "doc" command
2993 -36 common/cmd_doc.c No boot device
2994 36 common/cmd_doc.c correct boot device
2995 -37 common/cmd_doc.c Unknown Chip ID on boot device
2996 37 common/cmd_doc.c correct chip ID found, device available
2997 -38 common/cmd_doc.c Read Error on boot device
2998 38 common/cmd_doc.c reading Image header from DOC device OK
2999 -39 common/cmd_doc.c Image header has bad magic number
3000 39 common/cmd_doc.c Image header has correct magic number
3001 -40 common/cmd_doc.c Error reading Image from DOC device
3002 40 common/cmd_doc.c Image header has correct magic number
3003 41 common/cmd_ide.c before loading a Image from a IDE device
3004 -42 common/cmd_ide.c Bad usage of "ide" command
3005 42 common/cmd_ide.c correct usage of "ide" command
3006 -43 common/cmd_ide.c No boot device
3007 43 common/cmd_ide.c boot device found
3008 -44 common/cmd_ide.c Device not available
3009 44 common/cmd_ide.c Device available
3010 -45 common/cmd_ide.c wrong partition selected
3011 45 common/cmd_ide.c partition selected
3012 -46 common/cmd_ide.c Unknown partition table
3013 46 common/cmd_ide.c valid partition table found
3014 -47 common/cmd_ide.c Invalid partition type
3015 47 common/cmd_ide.c correct partition type
3016 -48 common/cmd_ide.c Error reading Image Header on boot device
3017 48 common/cmd_ide.c reading Image Header from IDE device OK
3018 -49 common/cmd_ide.c Image header has bad magic number
3019 49 common/cmd_ide.c Image header has correct magic number
3020 -50 common/cmd_ide.c Image header has bad checksum
3021 50 common/cmd_ide.c Image header has correct checksum
3022 -51 common/cmd_ide.c Error reading Image from IDE device
3023 51 common/cmd_ide.c reading Image from IDE device OK
3024 52 common/cmd_nand.c before loading a Image from a NAND device
3025 -53 common/cmd_nand.c Bad usage of "nand" command
3026 53 common/cmd_nand.c correct usage of "nand" command
3027 -54 common/cmd_nand.c No boot device
3028 54 common/cmd_nand.c boot device found
3029 -55 common/cmd_nand.c Unknown Chip ID on boot device
3030 55 common/cmd_nand.c correct chip ID found, device available
3031 -56 common/cmd_nand.c Error reading Image Header on boot device
3032 56 common/cmd_nand.c reading Image Header from NAND device OK
3033 -57 common/cmd_nand.c Image header has bad magic number
3034 57 common/cmd_nand.c Image header has correct magic number
3035 -58 common/cmd_nand.c Error reading Image from NAND device
3036 58 common/cmd_nand.c reading Image from NAND device OK
3038 -60 common/env_common.c Environment has a bad CRC, using default
3040 64 net/eth.c starting with Ethernet configuration.
3041 -64 net/eth.c no Ethernet found.
3042 65 net/eth.c Ethernet found.
3044 -80 common/cmd_net.c usage wrong
3045 80 common/cmd_net.c before calling NetLoop()
3046 -81 common/cmd_net.c some error in NetLoop() occurred
3047 81 common/cmd_net.c NetLoop() back without error
3048 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3049 82 common/cmd_net.c trying automatic boot
3050 83 common/cmd_net.c running "source" command
3051 -83 common/cmd_net.c some error in automatic boot or "source" command
3052 84 common/cmd_net.c end without errors
3057 100 common/cmd_bootm.c Kernel FIT Image has correct format
3058 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3059 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3060 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3061 102 common/cmd_bootm.c Kernel unit name specified
3062 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3063 103 common/cmd_bootm.c Found configuration node
3064 104 common/cmd_bootm.c Got kernel subimage node offset
3065 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3066 105 common/cmd_bootm.c Kernel subimage hash verification OK
3067 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3068 106 common/cmd_bootm.c Architecture check OK
3069 -106 common/cmd_bootm.c Kernel subimage has wrong type
3070 107 common/cmd_bootm.c Kernel subimage type OK
3071 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3072 108 common/cmd_bootm.c Got kernel subimage data/size
3073 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3074 -109 common/cmd_bootm.c Can't get kernel subimage type
3075 -110 common/cmd_bootm.c Can't get kernel subimage comp
3076 -111 common/cmd_bootm.c Can't get kernel subimage os
3077 -112 common/cmd_bootm.c Can't get kernel subimage load address
3078 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3080 120 common/image.c Start initial ramdisk verification
3081 -120 common/image.c Ramdisk FIT image has incorrect format
3082 121 common/image.c Ramdisk FIT image has correct format
3083 122 common/image.c No ramdisk subimage unit name, using configuration
3084 -122 common/image.c Can't get configuration for ramdisk subimage
3085 123 common/image.c Ramdisk unit name specified
3086 -124 common/image.c Can't get ramdisk subimage node offset
3087 125 common/image.c Got ramdisk subimage node offset
3088 -125 common/image.c Ramdisk subimage hash verification failed
3089 126 common/image.c Ramdisk subimage hash verification OK
3090 -126 common/image.c Ramdisk subimage for unsupported architecture
3091 127 common/image.c Architecture check OK
3092 -127 common/image.c Can't get ramdisk subimage data/size
3093 128 common/image.c Got ramdisk subimage data/size
3094 129 common/image.c Can't get ramdisk load address
3095 -129 common/image.c Got ramdisk load address
3097 -130 common/cmd_doc.c Incorrect FIT image format
3098 131 common/cmd_doc.c FIT image format OK
3100 -140 common/cmd_ide.c Incorrect FIT image format
3101 141 common/cmd_ide.c FIT image format OK
3103 -150 common/cmd_nand.c Incorrect FIT image format
3104 151 common/cmd_nand.c FIT image format OK
3106 - FIT image support:
3108 Enable support for the FIT uImage format.
3110 CONFIG_FIT_BEST_MATCH
3111 When no configuration is explicitly selected, default to the
3112 one whose fdt's compatibility field best matches that of
3113 U-Boot itself. A match is considered "best" if it matches the
3114 most specific compatibility entry of U-Boot's fdt's root node.
3115 The order of entries in the configuration's fdt is ignored.
3117 CONFIG_FIT_SIGNATURE
3118 This option enables signature verification of FIT uImages,
3119 using a hash signed and verified using RSA. See
3120 doc/uImage.FIT/signature.txt for more details.
3122 - Standalone program support:
3123 CONFIG_STANDALONE_LOAD_ADDR
3125 This option defines a board specific value for the
3126 address where standalone program gets loaded, thus
3127 overwriting the architecture dependent default
3130 - Frame Buffer Address:
3133 Define CONFIG_FB_ADDR if you want to use specific
3134 address for frame buffer. This is typically the case
3135 when using a graphics controller has separate video
3136 memory. U-Boot will then place the frame buffer at
3137 the given address instead of dynamically reserving it
3138 in system RAM by calling lcd_setmem(), which grabs
3139 the memory for the frame buffer depending on the
3140 configured panel size.
3142 Please see board_init_f function.
3144 - Automatic software updates via TFTP server
3146 CONFIG_UPDATE_TFTP_CNT_MAX
3147 CONFIG_UPDATE_TFTP_MSEC_MAX
3149 These options enable and control the auto-update feature;
3150 for a more detailed description refer to doc/README.update.
3152 - MTD Support (mtdparts command, UBI support)
3155 Adds the MTD device infrastructure from the Linux kernel.
3156 Needed for mtdparts command support.
3158 CONFIG_MTD_PARTITIONS
3160 Adds the MTD partitioning infrastructure from the Linux
3161 kernel. Needed for UBI support.
3166 Adds commands for interacting with MTD partitions formatted
3167 with the UBI flash translation layer
3169 Requires also defining CONFIG_RBTREE
3171 CONFIG_UBI_SILENCE_MSG
3173 Make the verbose messages from UBI stop printing. This leaves
3174 warnings and errors enabled.
3179 Adds commands for interacting with UBI volumes formatted as
3180 UBIFS. UBIFS is read-only in u-boot.
3182 Requires UBI support as well as CONFIG_LZO
3184 CONFIG_UBIFS_SILENCE_MSG
3186 Make the verbose messages from UBIFS stop printing. This leaves
3187 warnings and errors enabled.
3191 Enable building of SPL globally.
3194 LDSCRIPT for linking the SPL binary.
3196 CONFIG_SPL_MAX_FOOTPRINT
3197 Maximum size in memory allocated to the SPL, BSS included.
3198 When defined, the linker checks that the actual memory
3199 used by SPL from _start to __bss_end does not exceed it.
3200 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3201 must not be both defined at the same time.
3204 Maximum size of the SPL image (text, data, rodata, and
3205 linker lists sections), BSS excluded.
3206 When defined, the linker checks that the actual size does
3209 CONFIG_SPL_TEXT_BASE
3210 TEXT_BASE for linking the SPL binary.
3212 CONFIG_SPL_RELOC_TEXT_BASE
3213 Address to relocate to. If unspecified, this is equal to
3214 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3216 CONFIG_SPL_BSS_START_ADDR
3217 Link address for the BSS within the SPL binary.
3219 CONFIG_SPL_BSS_MAX_SIZE
3220 Maximum size in memory allocated to the SPL BSS.
3221 When defined, the linker checks that the actual memory used
3222 by SPL from __bss_start to __bss_end does not exceed it.
3223 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3224 must not be both defined at the same time.
3227 Adress of the start of the stack SPL will use
3229 CONFIG_SPL_RELOC_STACK
3230 Adress of the start of the stack SPL will use after
3231 relocation. If unspecified, this is equal to
3234 CONFIG_SYS_SPL_MALLOC_START
3235 Starting address of the malloc pool used in SPL.
3237 CONFIG_SYS_SPL_MALLOC_SIZE
3238 The size of the malloc pool used in SPL.
3240 CONFIG_SPL_FRAMEWORK
3241 Enable the SPL framework under common/. This framework
3242 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3243 NAND loading of the Linux Kernel.
3245 CONFIG_SPL_DISPLAY_PRINT
3246 For ARM, enable an optional function to print more information
3247 about the running system.
3249 CONFIG_SPL_INIT_MINIMAL
3250 Arch init code should be built for a very small image
3252 CONFIG_SPL_LIBCOMMON_SUPPORT
3253 Support for common/libcommon.o in SPL binary
3255 CONFIG_SPL_LIBDISK_SUPPORT
3256 Support for disk/libdisk.o in SPL binary
3258 CONFIG_SPL_I2C_SUPPORT
3259 Support for drivers/i2c/libi2c.o in SPL binary
3261 CONFIG_SPL_GPIO_SUPPORT
3262 Support for drivers/gpio/libgpio.o in SPL binary
3264 CONFIG_SPL_MMC_SUPPORT
3265 Support for drivers/mmc/libmmc.o in SPL binary
3267 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3268 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3269 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3270 Address, size and partition on the MMC to load U-Boot from
3271 when the MMC is being used in raw mode.
3273 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3274 Sector to load kernel uImage from when MMC is being
3275 used in raw mode (for Falcon mode)
3277 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3278 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3279 Sector and number of sectors to load kernel argument
3280 parameters from when MMC is being used in raw mode
3283 CONFIG_SPL_FAT_SUPPORT
3284 Support for fs/fat/libfat.o in SPL binary
3286 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3287 Filename to read to load U-Boot when reading from FAT
3289 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3290 Filename to read to load kernel uImage when reading
3291 from FAT (for Falcon mode)
3293 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3294 Filename to read to load kernel argument parameters
3295 when reading from FAT (for Falcon mode)
3297 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3298 Set this for NAND SPL on PPC mpc83xx targets, so that
3299 start.S waits for the rest of the SPL to load before
3300 continuing (the hardware starts execution after just
3301 loading the first page rather than the full 4K).
3303 CONFIG_SPL_NAND_BASE
3304 Include nand_base.c in the SPL. Requires
3305 CONFIG_SPL_NAND_DRIVERS.
3307 CONFIG_SPL_NAND_DRIVERS
3308 SPL uses normal NAND drivers, not minimal drivers.
3311 Include standard software ECC in the SPL
3313 CONFIG_SPL_NAND_SIMPLE
3314 Support for NAND boot using simple NAND drivers that
3315 expose the cmd_ctrl() interface.
3317 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3318 Set for the SPL on PPC mpc8xxx targets, support for
3319 drivers/ddr/fsl/libddr.o in SPL binary.
3321 CONFIG_SPL_COMMON_INIT_DDR
3322 Set for common ddr init with serial presence detect in
3325 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3326 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3327 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3328 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3329 CONFIG_SYS_NAND_ECCBYTES
3330 Defines the size and behavior of the NAND that SPL uses
3333 CONFIG_SPL_NAND_BOOT
3334 Add support NAND boot
3336 CONFIG_SYS_NAND_U_BOOT_OFFS
3337 Location in NAND to read U-Boot from
3339 CONFIG_SYS_NAND_U_BOOT_DST
3340 Location in memory to load U-Boot to
3342 CONFIG_SYS_NAND_U_BOOT_SIZE
3343 Size of image to load
3345 CONFIG_SYS_NAND_U_BOOT_START
3346 Entry point in loaded image to jump to
3348 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3349 Define this if you need to first read the OOB and then the
3350 data. This is used for example on davinci plattforms.
3352 CONFIG_SPL_OMAP3_ID_NAND
3353 Support for an OMAP3-specific set of functions to return the
3354 ID and MFR of the first attached NAND chip, if present.
3356 CONFIG_SPL_SERIAL_SUPPORT
3357 Support for drivers/serial/libserial.o in SPL binary
3359 CONFIG_SPL_SPI_FLASH_SUPPORT
3360 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3362 CONFIG_SPL_SPI_SUPPORT
3363 Support for drivers/spi/libspi.o in SPL binary
3365 CONFIG_SPL_RAM_DEVICE
3366 Support for running image already present in ram, in SPL binary
3368 CONFIG_SPL_LIBGENERIC_SUPPORT
3369 Support for lib/libgeneric.o in SPL binary
3371 CONFIG_SPL_ENV_SUPPORT
3372 Support for the environment operating in SPL binary
3374 CONFIG_SPL_NET_SUPPORT
3375 Support for the net/libnet.o in SPL binary.
3376 It conflicts with SPL env from storage medium specified by
3377 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3380 Image offset to which the SPL should be padded before appending
3381 the SPL payload. By default, this is defined as
3382 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3383 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3384 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3387 Final target image containing SPL and payload. Some SPLs
3388 use an arch-specific makefile fragment instead, for
3389 example if more than one image needs to be produced.
3391 CONFIG_FIT_SPL_PRINT
3392 Printing information about a FIT image adds quite a bit of
3393 code to SPL. So this is normally disabled in SPL. Use this
3394 option to re-enable it. This will affect the output of the
3395 bootm command when booting a FIT image.
3399 Enable building of TPL globally.
3402 Image offset to which the TPL should be padded before appending
3403 the TPL payload. By default, this is defined as
3404 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3405 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3406 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3411 [so far only for SMDK2400 boards]
3413 - Modem support enable:
3414 CONFIG_MODEM_SUPPORT
3416 - RTS/CTS Flow control enable:
3419 - Modem debug support:
3420 CONFIG_MODEM_SUPPORT_DEBUG
3422 Enables debugging stuff (char screen[1024], dbg())
3423 for modem support. Useful only with BDI2000.
3425 - Interrupt support (PPC):
3427 There are common interrupt_init() and timer_interrupt()
3428 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3429 for CPU specific initialization. interrupt_init_cpu()
3430 should set decrementer_count to appropriate value. If
3431 CPU resets decrementer automatically after interrupt
3432 (ppc4xx) it should set decrementer_count to zero.
3433 timer_interrupt() calls timer_interrupt_cpu() for CPU
3434 specific handling. If board has watchdog / status_led
3435 / other_activity_monitor it works automatically from
3436 general timer_interrupt().
3440 In the target system modem support is enabled when a
3441 specific key (key combination) is pressed during
3442 power-on. Otherwise U-Boot will boot normally
3443 (autoboot). The key_pressed() function is called from
3444 board_init(). Currently key_pressed() is a dummy
3445 function, returning 1 and thus enabling modem
3448 If there are no modem init strings in the
3449 environment, U-Boot proceed to autoboot; the
3450 previous output (banner, info printfs) will be
3453 See also: doc/README.Modem
3455 Board initialization settings:
3456 ------------------------------
3458 During Initialization u-boot calls a number of board specific functions
3459 to allow the preparation of board specific prerequisites, e.g. pin setup
3460 before drivers are initialized. To enable these callbacks the
3461 following configuration macros have to be defined. Currently this is
3462 architecture specific, so please check arch/your_architecture/lib/board.c
3463 typically in board_init_f() and board_init_r().
3465 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3466 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3467 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3468 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3470 Configuration Settings:
3471 -----------------------
3473 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3474 undefine this when you're short of memory.
3476 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3477 width of the commands listed in the 'help' command output.
3479 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3480 prompt for user input.
3482 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3484 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3486 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3488 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3489 the application (usually a Linux kernel) when it is
3492 - CONFIG_SYS_BAUDRATE_TABLE:
3493 List of legal baudrate settings for this board.
3495 - CONFIG_SYS_CONSOLE_INFO_QUIET
3496 Suppress display of console information at boot.
3498 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3499 If the board specific function
3500 extern int overwrite_console (void);
3501 returns 1, the stdin, stderr and stdout are switched to the
3502 serial port, else the settings in the environment are used.
3504 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3505 Enable the call to overwrite_console().
3507 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3508 Enable overwrite of previous console environment settings.
3510 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3511 Begin and End addresses of the area used by the
3514 - CONFIG_SYS_ALT_MEMTEST:
3515 Enable an alternate, more extensive memory test.
3517 - CONFIG_SYS_MEMTEST_SCRATCH:
3518 Scratch address used by the alternate memory test
3519 You only need to set this if address zero isn't writeable
3521 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3522 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3523 this specified memory area will get subtracted from the top
3524 (end) of RAM and won't get "touched" at all by U-Boot. By
3525 fixing up gd->ram_size the Linux kernel should gets passed
3526 the now "corrected" memory size and won't touch it either.
3527 This should work for arch/ppc and arch/powerpc. Only Linux
3528 board ports in arch/powerpc with bootwrapper support that
3529 recalculate the memory size from the SDRAM controller setup
3530 will have to get fixed in Linux additionally.
3532 This option can be used as a workaround for the 440EPx/GRx
3533 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3536 WARNING: Please make sure that this value is a multiple of
3537 the Linux page size (normally 4k). If this is not the case,
3538 then the end address of the Linux memory will be located at a
3539 non page size aligned address and this could cause major
3542 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3543 Enable temporary baudrate change while serial download
3545 - CONFIG_SYS_SDRAM_BASE:
3546 Physical start address of SDRAM. _Must_ be 0 here.
3548 - CONFIG_SYS_MBIO_BASE:
3549 Physical start address of Motherboard I/O (if using a
3552 - CONFIG_SYS_FLASH_BASE:
3553 Physical start address of Flash memory.
3555 - CONFIG_SYS_MONITOR_BASE:
3556 Physical start address of boot monitor code (set by
3557 make config files to be same as the text base address
3558 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3559 CONFIG_SYS_FLASH_BASE when booting from flash.
3561 - CONFIG_SYS_MONITOR_LEN:
3562 Size of memory reserved for monitor code, used to
3563 determine _at_compile_time_ (!) if the environment is
3564 embedded within the U-Boot image, or in a separate
3567 - CONFIG_SYS_MALLOC_LEN:
3568 Size of DRAM reserved for malloc() use.
3570 - CONFIG_SYS_BOOTM_LEN:
3571 Normally compressed uImages are limited to an
3572 uncompressed size of 8 MBytes. If this is not enough,
3573 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3574 to adjust this setting to your needs.
3576 - CONFIG_SYS_BOOTMAPSZ:
3577 Maximum size of memory mapped by the startup code of
3578 the Linux kernel; all data that must be processed by
3579 the Linux kernel (bd_info, boot arguments, FDT blob if
3580 used) must be put below this limit, unless "bootm_low"
3581 environment variable is defined and non-zero. In such case
3582 all data for the Linux kernel must be between "bootm_low"
3583 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3584 variable "bootm_mapsize" will override the value of
3585 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3586 then the value in "bootm_size" will be used instead.
3588 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3589 Enable initrd_high functionality. If defined then the
3590 initrd_high feature is enabled and the bootm ramdisk subcommand
3593 - CONFIG_SYS_BOOT_GET_CMDLINE:
3594 Enables allocating and saving kernel cmdline in space between
3595 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3597 - CONFIG_SYS_BOOT_GET_KBD:
3598 Enables allocating and saving a kernel copy of the bd_info in
3599 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3601 - CONFIG_SYS_MAX_FLASH_BANKS:
3602 Max number of Flash memory banks
3604 - CONFIG_SYS_MAX_FLASH_SECT:
3605 Max number of sectors on a Flash chip
3607 - CONFIG_SYS_FLASH_ERASE_TOUT:
3608 Timeout for Flash erase operations (in ms)
3610 - CONFIG_SYS_FLASH_WRITE_TOUT:
3611 Timeout for Flash write operations (in ms)
3613 - CONFIG_SYS_FLASH_LOCK_TOUT
3614 Timeout for Flash set sector lock bit operation (in ms)
3616 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3617 Timeout for Flash clear lock bits operation (in ms)
3619 - CONFIG_SYS_FLASH_PROTECTION
3620 If defined, hardware flash sectors protection is used
3621 instead of U-Boot software protection.
3623 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3625 Enable TFTP transfers directly to flash memory;
3626 without this option such a download has to be
3627 performed in two steps: (1) download to RAM, and (2)
3628 copy from RAM to flash.
3630 The two-step approach is usually more reliable, since
3631 you can check if the download worked before you erase
3632 the flash, but in some situations (when system RAM is
3633 too limited to allow for a temporary copy of the
3634 downloaded image) this option may be very useful.
3636 - CONFIG_SYS_FLASH_CFI:
3637 Define if the flash driver uses extra elements in the
3638 common flash structure for storing flash geometry.
3640 - CONFIG_FLASH_CFI_DRIVER
3641 This option also enables the building of the cfi_flash driver
3642 in the drivers directory
3644 - CONFIG_FLASH_CFI_MTD
3645 This option enables the building of the cfi_mtd driver
3646 in the drivers directory. The driver exports CFI flash
3649 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3650 Use buffered writes to flash.
3652 - CONFIG_FLASH_SPANSION_S29WS_N
3653 s29ws-n MirrorBit flash has non-standard addresses for buffered
3656 - CONFIG_SYS_FLASH_QUIET_TEST
3657 If this option is defined, the common CFI flash doesn't
3658 print it's warning upon not recognized FLASH banks. This
3659 is useful, if some of the configured banks are only
3660 optionally available.
3662 - CONFIG_FLASH_SHOW_PROGRESS
3663 If defined (must be an integer), print out countdown
3664 digits and dots. Recommended value: 45 (9..1) for 80
3665 column displays, 15 (3..1) for 40 column displays.
3667 - CONFIG_FLASH_VERIFY
3668 If defined, the content of the flash (destination) is compared
3669 against the source after the write operation. An error message
3670 will be printed when the contents are not identical.
3671 Please note that this option is useless in nearly all cases,
3672 since such flash programming errors usually are detected earlier
3673 while unprotecting/erasing/programming. Please only enable
3674 this option if you really know what you are doing.
3676 - CONFIG_SYS_RX_ETH_BUFFER:
3677 Defines the number of Ethernet receive buffers. On some
3678 Ethernet controllers it is recommended to set this value
3679 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3680 buffers can be full shortly after enabling the interface
3681 on high Ethernet traffic.
3682 Defaults to 4 if not defined.
3684 - CONFIG_ENV_MAX_ENTRIES
3686 Maximum number of entries in the hash table that is used
3687 internally to store the environment settings. The default
3688 setting is supposed to be generous and should work in most
3689 cases. This setting can be used to tune behaviour; see
3690 lib/hashtable.c for details.
3692 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3693 - CONFIG_ENV_FLAGS_LIST_STATIC
3694 Enable validation of the values given to environment variables when
3695 calling env set. Variables can be restricted to only decimal,
3696 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3697 the variables can also be restricted to IP address or MAC address.
3699 The format of the list is:
3700 type_attribute = [s|d|x|b|i|m]
3701 access_atribute = [a|r|o|c]
3702 attributes = type_attribute[access_atribute]
3703 entry = variable_name[:attributes]
3706 The type attributes are:
3707 s - String (default)
3710 b - Boolean ([1yYtT|0nNfF])
3714 The access attributes are:
3720 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3721 Define this to a list (string) to define the ".flags"
3722 envirnoment variable in the default or embedded environment.
3724 - CONFIG_ENV_FLAGS_LIST_STATIC
3725 Define this to a list (string) to define validation that
3726 should be done if an entry is not found in the ".flags"
3727 environment variable. To override a setting in the static
3728 list, simply add an entry for the same variable name to the
3731 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3732 If defined, don't allow the -f switch to env set override variable
3735 - CONFIG_SYS_GENERIC_BOARD
3736 This selects the architecture-generic board system instead of the
3737 architecture-specific board files. It is intended to move boards
3738 to this new framework over time. Defining this will disable the
3739 arch/foo/lib/board.c file and use common/board_f.c and
3740 common/board_r.c instead. To use this option your architecture
3741 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3742 its config.mk file). If you find problems enabling this option on
3743 your board please report the problem and send patches!
3745 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3746 This is set by OMAP boards for the max time that reset should
3747 be asserted. See doc/README.omap-reset-time for details on how
3748 the value can be calulated on a given board.
3750 The following definitions that deal with the placement and management
3751 of environment data (variable area); in general, we support the
3752 following configurations:
3754 - CONFIG_BUILD_ENVCRC:
3756 Builds up envcrc with the target environment so that external utils
3757 may easily extract it and embed it in final U-Boot images.
3759 - CONFIG_ENV_IS_IN_FLASH:
3761 Define this if the environment is in flash memory.
3763 a) The environment occupies one whole flash sector, which is
3764 "embedded" in the text segment with the U-Boot code. This
3765 happens usually with "bottom boot sector" or "top boot
3766 sector" type flash chips, which have several smaller
3767 sectors at the start or the end. For instance, such a
3768 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3769 such a case you would place the environment in one of the
3770 4 kB sectors - with U-Boot code before and after it. With
3771 "top boot sector" type flash chips, you would put the
3772 environment in one of the last sectors, leaving a gap
3773 between U-Boot and the environment.
3775 - CONFIG_ENV_OFFSET:
3777 Offset of environment data (variable area) to the
3778 beginning of flash memory; for instance, with bottom boot
3779 type flash chips the second sector can be used: the offset
3780 for this sector is given here.
3782 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3786 This is just another way to specify the start address of
3787 the flash sector containing the environment (instead of
3790 - CONFIG_ENV_SECT_SIZE:
3792 Size of the sector containing the environment.
3795 b) Sometimes flash chips have few, equal sized, BIG sectors.
3796 In such a case you don't want to spend a whole sector for
3801 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3802 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3803 of this flash sector for the environment. This saves
3804 memory for the RAM copy of the environment.
3806 It may also save flash memory if you decide to use this
3807 when your environment is "embedded" within U-Boot code,
3808 since then the remainder of the flash sector could be used
3809 for U-Boot code. It should be pointed out that this is
3810 STRONGLY DISCOURAGED from a robustness point of view:
3811 updating the environment in flash makes it always
3812 necessary to erase the WHOLE sector. If something goes
3813 wrong before the contents has been restored from a copy in
3814 RAM, your target system will be dead.
3816 - CONFIG_ENV_ADDR_REDUND
3817 CONFIG_ENV_SIZE_REDUND
3819 These settings describe a second storage area used to hold
3820 a redundant copy of the environment data, so that there is
3821 a valid backup copy in case there is a power failure during
3822 a "saveenv" operation.
3824 BE CAREFUL! Any changes to the flash layout, and some changes to the
3825 source code will make it necessary to adapt <board>/u-boot.lds*
3829 - CONFIG_ENV_IS_IN_NVRAM:
3831 Define this if you have some non-volatile memory device
3832 (NVRAM, battery buffered SRAM) which you want to use for the
3838 These two #defines are used to determine the memory area you
3839 want to use for environment. It is assumed that this memory
3840 can just be read and written to, without any special
3843 BE CAREFUL! The first access to the environment happens quite early
3844 in U-Boot initalization (when we try to get the setting of for the
3845 console baudrate). You *MUST* have mapped your NVRAM area then, or
3848 Please note that even with NVRAM we still use a copy of the
3849 environment in RAM: we could work on NVRAM directly, but we want to
3850 keep settings there always unmodified except somebody uses "saveenv"
3851 to save the current settings.
3854 - CONFIG_ENV_IS_IN_EEPROM:
3856 Use this if you have an EEPROM or similar serial access
3857 device and a driver for it.
3859 - CONFIG_ENV_OFFSET:
3862 These two #defines specify the offset and size of the
3863 environment area within the total memory of your EEPROM.
3865 - CONFIG_SYS_I2C_EEPROM_ADDR:
3866 If defined, specified the chip address of the EEPROM device.
3867 The default address is zero.
3869 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3870 If defined, the number of bits used to address bytes in a
3871 single page in the EEPROM device. A 64 byte page, for example
3872 would require six bits.
3874 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3875 If defined, the number of milliseconds to delay between
3876 page writes. The default is zero milliseconds.
3878 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3879 The length in bytes of the EEPROM memory array address. Note
3880 that this is NOT the chip address length!
3882 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3883 EEPROM chips that implement "address overflow" are ones
3884 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3885 address and the extra bits end up in the "chip address" bit
3886 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3889 Note that we consider the length of the address field to
3890 still be one byte because the extra address bits are hidden
3891 in the chip address.
3893 - CONFIG_SYS_EEPROM_SIZE:
3894 The size in bytes of the EEPROM device.
3896 - CONFIG_ENV_EEPROM_IS_ON_I2C
3897 define this, if you have I2C and SPI activated, and your
3898 EEPROM, which holds the environment, is on the I2C bus.
3900 - CONFIG_I2C_ENV_EEPROM_BUS
3901 if you have an Environment on an EEPROM reached over
3902 I2C muxes, you can define here, how to reach this
3903 EEPROM. For example:
3905 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3907 EEPROM which holds the environment, is reached over
3908 a pca9547 i2c mux with address 0x70, channel 3.
3910 - CONFIG_ENV_IS_IN_DATAFLASH:
3912 Define this if you have a DataFlash memory device which you
3913 want to use for the environment.
3915 - CONFIG_ENV_OFFSET:
3919 These three #defines specify the offset and size of the
3920 environment area within the total memory of your DataFlash placed
3921 at the specified address.
3923 - CONFIG_ENV_IS_IN_REMOTE:
3925 Define this if you have a remote memory space which you
3926 want to use for the local device's environment.
3931 These two #defines specify the address and size of the
3932 environment area within the remote memory space. The
3933 local device can get the environment from remote memory
3934 space by SRIO or PCIE links.
3936 BE CAREFUL! For some special cases, the local device can not use
3937 "saveenv" command. For example, the local device will get the
3938 environment stored in a remote NOR flash by SRIO or PCIE link,
3939 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3941 - CONFIG_ENV_IS_IN_NAND:
3943 Define this if you have a NAND device which you want to use
3944 for the environment.
3946 - CONFIG_ENV_OFFSET:
3949 These two #defines specify the offset and size of the environment
3950 area within the first NAND device. CONFIG_ENV_OFFSET must be
3951 aligned to an erase block boundary.
3953 - CONFIG_ENV_OFFSET_REDUND (optional):
3955 This setting describes a second storage area of CONFIG_ENV_SIZE
3956 size used to hold a redundant copy of the environment data, so
3957 that there is a valid backup copy in case there is a power failure
3958 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3959 aligned to an erase block boundary.
3961 - CONFIG_ENV_RANGE (optional):
3963 Specifies the length of the region in which the environment
3964 can be written. This should be a multiple of the NAND device's
3965 block size. Specifying a range with more erase blocks than
3966 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3967 the range to be avoided.
3969 - CONFIG_ENV_OFFSET_OOB (optional):
3971 Enables support for dynamically retrieving the offset of the
3972 environment from block zero's out-of-band data. The
3973 "nand env.oob" command can be used to record this offset.
3974 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3975 using CONFIG_ENV_OFFSET_OOB.
3977 - CONFIG_NAND_ENV_DST
3979 Defines address in RAM to which the nand_spl code should copy the
3980 environment. If redundant environment is used, it will be copied to
3981 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3983 - CONFIG_ENV_IS_IN_UBI:
3985 Define this if you have an UBI volume that you want to use for the
3986 environment. This has the benefit of wear-leveling the environment
3987 accesses, which is important on NAND.
3989 - CONFIG_ENV_UBI_PART:
3991 Define this to a string that is the mtd partition containing the UBI.
3993 - CONFIG_ENV_UBI_VOLUME:
3995 Define this to the name of the volume that you want to store the
3998 - CONFIG_ENV_UBI_VOLUME_REDUND:
4000 Define this to the name of another volume to store a second copy of
4001 the environment in. This will enable redundant environments in UBI.
4002 It is assumed that both volumes are in the same MTD partition.
4004 - CONFIG_UBI_SILENCE_MSG
4005 - CONFIG_UBIFS_SILENCE_MSG
4007 You will probably want to define these to avoid a really noisy system
4008 when storing the env in UBI.
4010 - CONFIG_ENV_IS_IN_MMC:
4012 Define this if you have an MMC device which you want to use for the
4015 - CONFIG_SYS_MMC_ENV_DEV:
4017 Specifies which MMC device the environment is stored in.
4019 - CONFIG_SYS_MMC_ENV_PART (optional):
4021 Specifies which MMC partition the environment is stored in. If not
4022 set, defaults to partition 0, the user area. Common values might be
4023 1 (first MMC boot partition), 2 (second MMC boot partition).
4025 - CONFIG_ENV_OFFSET:
4028 These two #defines specify the offset and size of the environment
4029 area within the specified MMC device.
4031 If offset is positive (the usual case), it is treated as relative to
4032 the start of the MMC partition. If offset is negative, it is treated
4033 as relative to the end of the MMC partition. This can be useful if
4034 your board may be fitted with different MMC devices, which have
4035 different sizes for the MMC partitions, and you always want the
4036 environment placed at the very end of the partition, to leave the
4037 maximum possible space before it, to store other data.
4039 These two values are in units of bytes, but must be aligned to an
4040 MMC sector boundary.
4042 - CONFIG_ENV_OFFSET_REDUND (optional):
4044 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4045 hold a redundant copy of the environment data. This provides a
4046 valid backup copy in case the other copy is corrupted, e.g. due
4047 to a power failure during a "saveenv" operation.
4049 This value may also be positive or negative; this is handled in the
4050 same way as CONFIG_ENV_OFFSET.
4052 This value is also in units of bytes, but must also be aligned to
4053 an MMC sector boundary.
4055 - CONFIG_ENV_SIZE_REDUND (optional):
4057 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4058 set. If this value is set, it must be set to the same value as
4061 - CONFIG_SYS_SPI_INIT_OFFSET
4063 Defines offset to the initial SPI buffer area in DPRAM. The
4064 area is used at an early stage (ROM part) if the environment
4065 is configured to reside in the SPI EEPROM: We need a 520 byte
4066 scratch DPRAM area. It is used between the two initialization
4067 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4068 to be a good choice since it makes it far enough from the
4069 start of the data area as well as from the stack pointer.
4071 Please note that the environment is read-only until the monitor
4072 has been relocated to RAM and a RAM copy of the environment has been
4073 created; also, when using EEPROM you will have to use getenv_f()
4074 until then to read environment variables.
4076 The environment is protected by a CRC32 checksum. Before the monitor
4077 is relocated into RAM, as a result of a bad CRC you will be working
4078 with the compiled-in default environment - *silently*!!! [This is
4079 necessary, because the first environment variable we need is the
4080 "baudrate" setting for the console - if we have a bad CRC, we don't
4081 have any device yet where we could complain.]
4083 Note: once the monitor has been relocated, then it will complain if
4084 the default environment is used; a new CRC is computed as soon as you
4085 use the "saveenv" command to store a valid environment.
4087 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4088 Echo the inverted Ethernet link state to the fault LED.
4090 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4091 also needs to be defined.
4093 - CONFIG_SYS_FAULT_MII_ADDR:
4094 MII address of the PHY to check for the Ethernet link state.
4096 - CONFIG_NS16550_MIN_FUNCTIONS:
4097 Define this if you desire to only have use of the NS16550_init
4098 and NS16550_putc functions for the serial driver located at
4099 drivers/serial/ns16550.c. This option is useful for saving
4100 space for already greatly restricted images, including but not
4101 limited to NAND_SPL configurations.
4103 - CONFIG_DISPLAY_BOARDINFO
4104 Display information about the board that U-Boot is running on
4105 when U-Boot starts up. The board function checkboard() is called
4108 - CONFIG_DISPLAY_BOARDINFO_LATE
4109 Similar to the previous option, but display this information
4110 later, once stdio is running and output goes to the LCD, if
4113 Low Level (hardware related) configuration options:
4114 ---------------------------------------------------
4116 - CONFIG_SYS_CACHELINE_SIZE:
4117 Cache Line Size of the CPU.
4119 - CONFIG_SYS_DEFAULT_IMMR:
4120 Default address of the IMMR after system reset.
4122 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4123 and RPXsuper) to be able to adjust the position of
4124 the IMMR register after a reset.
4126 - CONFIG_SYS_CCSRBAR_DEFAULT:
4127 Default (power-on reset) physical address of CCSR on Freescale
4130 - CONFIG_SYS_CCSRBAR:
4131 Virtual address of CCSR. On a 32-bit build, this is typically
4132 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4134 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4135 for cross-platform code that uses that macro instead.
4137 - CONFIG_SYS_CCSRBAR_PHYS:
4138 Physical address of CCSR. CCSR can be relocated to a new
4139 physical address, if desired. In this case, this macro should
4140 be set to that address. Otherwise, it should be set to the
4141 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4142 is typically relocated on 36-bit builds. It is recommended
4143 that this macro be defined via the _HIGH and _LOW macros:
4145 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4146 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4148 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4149 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4150 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4151 used in assembly code, so it must not contain typecasts or
4152 integer size suffixes (e.g. "ULL").
4154 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4155 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4156 used in assembly code, so it must not contain typecasts or
4157 integer size suffixes (e.g. "ULL").
4159 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4160 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4161 forced to a value that ensures that CCSR is not relocated.
4163 - Floppy Disk Support:
4164 CONFIG_SYS_FDC_DRIVE_NUMBER
4166 the default drive number (default value 0)
4168 CONFIG_SYS_ISA_IO_STRIDE
4170 defines the spacing between FDC chipset registers
4173 CONFIG_SYS_ISA_IO_OFFSET
4175 defines the offset of register from address. It
4176 depends on which part of the data bus is connected to
4177 the FDC chipset. (default value 0)
4179 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4180 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4183 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4184 fdc_hw_init() is called at the beginning of the FDC
4185 setup. fdc_hw_init() must be provided by the board
4186 source code. It is used to make hardware dependant
4190 Most IDE controllers were designed to be connected with PCI
4191 interface. Only few of them were designed for AHB interface.
4192 When software is doing ATA command and data transfer to
4193 IDE devices through IDE-AHB controller, some additional
4194 registers accessing to these kind of IDE-AHB controller
4197 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4198 DO NOT CHANGE unless you know exactly what you're
4199 doing! (11-4) [MPC8xx/82xx systems only]
4201 - CONFIG_SYS_INIT_RAM_ADDR:
4203 Start address of memory area that can be used for
4204 initial data and stack; please note that this must be
4205 writable memory that is working WITHOUT special
4206 initialization, i. e. you CANNOT use normal RAM which
4207 will become available only after programming the
4208 memory controller and running certain initialization
4211 U-Boot uses the following memory types:
4212 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4213 - MPC824X: data cache
4214 - PPC4xx: data cache
4216 - CONFIG_SYS_GBL_DATA_OFFSET:
4218 Offset of the initial data structure in the memory
4219 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4220 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4221 data is located at the end of the available space
4222 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4223 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4224 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4225 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4228 On the MPC824X (or other systems that use the data
4229 cache for initial memory) the address chosen for
4230 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4231 point to an otherwise UNUSED address space between
4232 the top of RAM and the start of the PCI space.
4234 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4236 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4238 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4240 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4242 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4244 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4246 - CONFIG_SYS_OR_TIMING_SDRAM:
4249 - CONFIG_SYS_MAMR_PTA:
4250 periodic timer for refresh
4252 - CONFIG_SYS_DER: Debug Event Register (37-47)
4254 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4255 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4256 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4257 CONFIG_SYS_BR1_PRELIM:
4258 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4260 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4261 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4262 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4263 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4265 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4266 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4267 Machine Mode Register and Memory Periodic Timer
4268 Prescaler definitions (SDRAM timing)
4270 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4271 enable I2C microcode relocation patch (MPC8xx);
4272 define relocation offset in DPRAM [DSP2]
4274 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4275 enable SMC microcode relocation patch (MPC8xx);
4276 define relocation offset in DPRAM [SMC1]
4278 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4279 enable SPI microcode relocation patch (MPC8xx);
4280 define relocation offset in DPRAM [SCC4]
4282 - CONFIG_SYS_USE_OSCCLK:
4283 Use OSCM clock mode on MBX8xx board. Be careful,
4284 wrong setting might damage your board. Read
4285 doc/README.MBX before setting this variable!
4287 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4288 Offset of the bootmode word in DPRAM used by post
4289 (Power On Self Tests). This definition overrides
4290 #define'd default value in commproc.h resp.
4293 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4294 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4295 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4296 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4297 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4298 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4299 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4300 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4301 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4303 - CONFIG_PCI_DISABLE_PCIE:
4304 Disable PCI-Express on systems where it is supported but not
4307 - CONFIG_PCI_ENUM_ONLY
4308 Only scan through and get the devices on the busses.
4309 Don't do any setup work, presumably because someone or
4310 something has already done it, and we don't need to do it
4311 a second time. Useful for platforms that are pre-booted
4312 by coreboot or similar.
4314 - CONFIG_PCI_INDIRECT_BRIDGE:
4315 Enable support for indirect PCI bridges.
4318 Chip has SRIO or not
4321 Board has SRIO 1 port available
4324 Board has SRIO 2 port available
4326 - CONFIG_SRIO_PCIE_BOOT_MASTER
4327 Board can support master function for Boot from SRIO and PCIE
4329 - CONFIG_SYS_SRIOn_MEM_VIRT:
4330 Virtual Address of SRIO port 'n' memory region
4332 - CONFIG_SYS_SRIOn_MEM_PHYS:
4333 Physical Address of SRIO port 'n' memory region
4335 - CONFIG_SYS_SRIOn_MEM_SIZE:
4336 Size of SRIO port 'n' memory region
4338 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4339 Defined to tell the NAND controller that the NAND chip is using
4341 Not all NAND drivers use this symbol.
4342 Example of drivers that use it:
4343 - drivers/mtd/nand/ndfc.c
4344 - drivers/mtd/nand/mxc_nand.c
4346 - CONFIG_SYS_NDFC_EBC0_CFG
4347 Sets the EBC0_CFG register for the NDFC. If not defined
4348 a default value will be used.
4351 Get DDR timing information from an I2C EEPROM. Common
4352 with pluggable memory modules such as SODIMMs
4355 I2C address of the SPD EEPROM
4357 - CONFIG_SYS_SPD_BUS_NUM
4358 If SPD EEPROM is on an I2C bus other than the first
4359 one, specify here. Note that the value must resolve
4360 to something your driver can deal with.
4362 - CONFIG_SYS_DDR_RAW_TIMING
4363 Get DDR timing information from other than SPD. Common with
4364 soldered DDR chips onboard without SPD. DDR raw timing
4365 parameters are extracted from datasheet and hard-coded into
4366 header files or board specific files.
4368 - CONFIG_FSL_DDR_INTERACTIVE
4369 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4371 - CONFIG_SYS_83XX_DDR_USES_CS0
4372 Only for 83xx systems. If specified, then DDR should
4373 be configured using CS0 and CS1 instead of CS2 and CS3.
4375 - CONFIG_ETHER_ON_FEC[12]
4376 Define to enable FEC[12] on a 8xx series processor.
4378 - CONFIG_FEC[12]_PHY
4379 Define to the hardcoded PHY address which corresponds
4380 to the given FEC; i. e.
4381 #define CONFIG_FEC1_PHY 4
4382 means that the PHY with address 4 is connected to FEC1
4384 When set to -1, means to probe for first available.
4386 - CONFIG_FEC[12]_PHY_NORXERR
4387 The PHY does not have a RXERR line (RMII only).
4388 (so program the FEC to ignore it).
4391 Enable RMII mode for all FECs.
4392 Note that this is a global option, we can't
4393 have one FEC in standard MII mode and another in RMII mode.
4395 - CONFIG_CRC32_VERIFY
4396 Add a verify option to the crc32 command.
4399 => crc32 -v <address> <count> <crc32>
4401 Where address/count indicate a memory area
4402 and crc32 is the correct crc32 which the
4406 Add the "loopw" memory command. This only takes effect if
4407 the memory commands are activated globally (CONFIG_CMD_MEM).
4410 Add the "mdc" and "mwc" memory commands. These are cyclic
4415 This command will print 4 bytes (10,11,12,13) each 500 ms.
4417 => mwc.l 100 12345678 10
4418 This command will write 12345678 to address 100 all 10 ms.
4420 This only takes effect if the memory commands are activated
4421 globally (CONFIG_CMD_MEM).
4423 - CONFIG_SKIP_LOWLEVEL_INIT
4424 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4425 low level initializations (like setting up the memory
4426 controller) are omitted and/or U-Boot does not
4427 relocate itself into RAM.
4429 Normally this variable MUST NOT be defined. The only
4430 exception is when U-Boot is loaded (to RAM) by some
4431 other boot loader or by a debugger which performs
4432 these initializations itself.
4435 Modifies the behaviour of start.S when compiling a loader
4436 that is executed before the actual U-Boot. E.g. when
4437 compiling a NAND SPL.
4440 Modifies the behaviour of start.S when compiling a loader
4441 that is executed after the SPL and before the actual U-Boot.
4442 It is loaded by the SPL.
4444 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4445 Only for 85xx systems. If this variable is specified, the section
4446 .resetvec is not kept and the section .bootpg is placed in the
4447 previous 4k of the .text section.
4449 - CONFIG_ARCH_MAP_SYSMEM
4450 Generally U-Boot (and in particular the md command) uses
4451 effective address. It is therefore not necessary to regard
4452 U-Boot address as virtual addresses that need to be translated
4453 to physical addresses. However, sandbox requires this, since
4454 it maintains its own little RAM buffer which contains all
4455 addressable memory. This option causes some memory accesses
4456 to be mapped through map_sysmem() / unmap_sysmem().
4458 - CONFIG_USE_ARCH_MEMCPY
4459 CONFIG_USE_ARCH_MEMSET
4460 If these options are used a optimized version of memcpy/memset will
4461 be used if available. These functions may be faster under some
4462 conditions but may increase the binary size.
4464 - CONFIG_X86_RESET_VECTOR
4465 If defined, the x86 reset vector code is included. This is not
4466 needed when U-Boot is running from Coreboot.
4469 Defines the MPU clock speed (in MHz).
4471 NOTE : currently only supported on AM335x platforms.
4473 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4474 Enables the RTC32K OSC on AM33xx based plattforms
4476 Freescale QE/FMAN Firmware Support:
4477 -----------------------------------
4479 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4480 loading of "firmware", which is encoded in the QE firmware binary format.
4481 This firmware often needs to be loaded during U-Boot booting, so macros
4482 are used to identify the storage device (NOR flash, SPI, etc) and the address
4485 - CONFIG_SYS_QE_FMAN_FW_ADDR
4486 The address in the storage device where the firmware is located. The
4487 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4490 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4491 The maximum possible size of the firmware. The firmware binary format
4492 has a field that specifies the actual size of the firmware, but it
4493 might not be possible to read any part of the firmware unless some
4494 local storage is allocated to hold the entire firmware first.
4496 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4497 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4498 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4499 virtual address in NOR flash.
4501 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4502 Specifies that QE/FMAN firmware is located in NAND flash.
4503 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4505 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4506 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4507 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4509 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4510 Specifies that QE/FMAN firmware is located on the primary SPI
4511 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4513 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4514 Specifies that QE/FMAN firmware is located in the remote (master)
4515 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4516 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4517 window->master inbound window->master LAW->the ucode address in
4518 master's memory space.
4520 Building the Software:
4521 ======================
4523 Building U-Boot has been tested in several native build environments
4524 and in many different cross environments. Of course we cannot support
4525 all possibly existing versions of cross development tools in all
4526 (potentially obsolete) versions. In case of tool chain problems we
4527 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4528 which is extensively used to build and test U-Boot.
4530 If you are not using a native environment, it is assumed that you
4531 have GNU cross compiling tools available in your path. In this case,
4532 you must set the environment variable CROSS_COMPILE in your shell.
4533 Note that no changes to the Makefile or any other source files are
4534 necessary. For example using the ELDK on a 4xx CPU, please enter:
4536 $ CROSS_COMPILE=ppc_4xx-
4537 $ export CROSS_COMPILE
4539 Note: If you wish to generate Windows versions of the utilities in
4540 the tools directory you can use the MinGW toolchain
4541 (http://www.mingw.org). Set your HOST tools to the MinGW
4542 toolchain and execute 'make tools'. For example:
4544 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4546 Binaries such as tools/mkimage.exe will be created which can
4547 be executed on computers running Windows.
4549 U-Boot is intended to be simple to build. After installing the
4550 sources you must configure U-Boot for one specific board type. This
4555 where "NAME_config" is the name of one of the existing configu-
4556 rations; see boards.cfg for supported names.
4558 Note: for some board special configuration names may exist; check if
4559 additional information is available from the board vendor; for
4560 instance, the TQM823L systems are available without (standard)
4561 or with LCD support. You can select such additional "features"
4562 when choosing the configuration, i. e.
4565 - will configure for a plain TQM823L, i. e. no LCD support
4567 make TQM823L_LCD_config
4568 - will configure for a TQM823L with U-Boot console on LCD
4573 Finally, type "make all", and you should get some working U-Boot
4574 images ready for download to / installation on your system:
4576 - "u-boot.bin" is a raw binary image
4577 - "u-boot" is an image in ELF binary format
4578 - "u-boot.srec" is in Motorola S-Record format
4580 By default the build is performed locally and the objects are saved
4581 in the source directory. One of the two methods can be used to change
4582 this behavior and build U-Boot to some external directory:
4584 1. Add O= to the make command line invocations:
4586 make O=/tmp/build distclean
4587 make O=/tmp/build NAME_config
4588 make O=/tmp/build all
4590 2. Set environment variable BUILD_DIR to point to the desired location:
4592 export BUILD_DIR=/tmp/build
4597 Note that the command line "O=" setting overrides the BUILD_DIR environment
4601 Please be aware that the Makefiles assume you are using GNU make, so
4602 for instance on NetBSD you might need to use "gmake" instead of
4606 If the system board that you have is not listed, then you will need
4607 to port U-Boot to your hardware platform. To do this, follow these
4610 1. Add a new configuration option for your board to the toplevel
4611 "boards.cfg" file, using the existing entries as examples.
4612 Follow the instructions there to keep the boards in order.
4613 2. Create a new directory to hold your board specific code. Add any
4614 files you need. In your board directory, you will need at least
4615 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4616 3. Create a new configuration file "include/configs/<board>.h" for
4618 3. If you're porting U-Boot to a new CPU, then also create a new
4619 directory to hold your CPU specific code. Add any files you need.
4620 4. Run "make <board>_config" with your new name.
4621 5. Type "make", and you should get a working "u-boot.srec" file
4622 to be installed on your target system.
4623 6. Debug and solve any problems that might arise.
4624 [Of course, this last step is much harder than it sounds.]
4627 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4628 ==============================================================
4630 If you have modified U-Boot sources (for instance added a new board
4631 or support for new devices, a new CPU, etc.) you are expected to
4632 provide feedback to the other developers. The feedback normally takes
4633 the form of a "patch", i. e. a context diff against a certain (latest
4634 official or latest in the git repository) version of U-Boot sources.
4636 But before you submit such a patch, please verify that your modifi-
4637 cation did not break existing code. At least make sure that *ALL* of
4638 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4639 just run the "MAKEALL" script, which will configure and build U-Boot
4640 for ALL supported system. Be warned, this will take a while. You can
4641 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4642 environment variable to the script, i. e. to use the ELDK cross tools
4645 CROSS_COMPILE=ppc_8xx- MAKEALL
4647 or to build on a native PowerPC system you can type
4649 CROSS_COMPILE=' ' MAKEALL
4651 When using the MAKEALL script, the default behaviour is to build
4652 U-Boot in the source directory. This location can be changed by
4653 setting the BUILD_DIR environment variable. Also, for each target
4654 built, the MAKEALL script saves two log files (<target>.ERR and
4655 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4656 location can be changed by setting the MAKEALL_LOGDIR environment
4657 variable. For example:
4659 export BUILD_DIR=/tmp/build
4660 export MAKEALL_LOGDIR=/tmp/log
4661 CROSS_COMPILE=ppc_8xx- MAKEALL
4663 With the above settings build objects are saved in the /tmp/build,
4664 log files are saved in the /tmp/log and the source tree remains clean
4665 during the whole build process.
4668 See also "U-Boot Porting Guide" below.
4671 Monitor Commands - Overview:
4672 ============================
4674 go - start application at address 'addr'
4675 run - run commands in an environment variable
4676 bootm - boot application image from memory
4677 bootp - boot image via network using BootP/TFTP protocol
4678 bootz - boot zImage from memory
4679 tftpboot- boot image via network using TFTP protocol
4680 and env variables "ipaddr" and "serverip"
4681 (and eventually "gatewayip")
4682 tftpput - upload a file via network using TFTP protocol
4683 rarpboot- boot image via network using RARP/TFTP protocol
4684 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4685 loads - load S-Record file over serial line
4686 loadb - load binary file over serial line (kermit mode)
4688 mm - memory modify (auto-incrementing)
4689 nm - memory modify (constant address)
4690 mw - memory write (fill)
4692 cmp - memory compare
4693 crc32 - checksum calculation
4694 i2c - I2C sub-system
4695 sspi - SPI utility commands
4696 base - print or set address offset
4697 printenv- print environment variables
4698 setenv - set environment variables
4699 saveenv - save environment variables to persistent storage
4700 protect - enable or disable FLASH write protection
4701 erase - erase FLASH memory
4702 flinfo - print FLASH memory information
4703 nand - NAND memory operations (see doc/README.nand)
4704 bdinfo - print Board Info structure
4705 iminfo - print header information for application image
4706 coninfo - print console devices and informations
4707 ide - IDE sub-system
4708 loop - infinite loop on address range
4709 loopw - infinite write loop on address range
4710 mtest - simple RAM test
4711 icache - enable or disable instruction cache
4712 dcache - enable or disable data cache
4713 reset - Perform RESET of the CPU
4714 echo - echo args to console
4715 version - print monitor version
4716 help - print online help
4717 ? - alias for 'help'
4720 Monitor Commands - Detailed Description:
4721 ========================================
4725 For now: just type "help <command>".
4728 Environment Variables:
4729 ======================
4731 U-Boot supports user configuration using Environment Variables which
4732 can be made persistent by saving to Flash memory.
4734 Environment Variables are set using "setenv", printed using
4735 "printenv", and saved to Flash using "saveenv". Using "setenv"
4736 without a value can be used to delete a variable from the
4737 environment. As long as you don't save the environment you are
4738 working with an in-memory copy. In case the Flash area containing the
4739 environment is erased by accident, a default environment is provided.
4741 Some configuration options can be set using Environment Variables.
4743 List of environment variables (most likely not complete):
4745 baudrate - see CONFIG_BAUDRATE
4747 bootdelay - see CONFIG_BOOTDELAY
4749 bootcmd - see CONFIG_BOOTCOMMAND
4751 bootargs - Boot arguments when booting an RTOS image
4753 bootfile - Name of the image to load with TFTP
4755 bootm_low - Memory range available for image processing in the bootm
4756 command can be restricted. This variable is given as
4757 a hexadecimal number and defines lowest address allowed
4758 for use by the bootm command. See also "bootm_size"
4759 environment variable. Address defined by "bootm_low" is
4760 also the base of the initial memory mapping for the Linux
4761 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4764 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4765 This variable is given as a hexadecimal number and it
4766 defines the size of the memory region starting at base
4767 address bootm_low that is accessible by the Linux kernel
4768 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4769 as the default value if it is defined, and bootm_size is
4772 bootm_size - Memory range available for image processing in the bootm
4773 command can be restricted. This variable is given as
4774 a hexadecimal number and defines the size of the region
4775 allowed for use by the bootm command. See also "bootm_low"
4776 environment variable.
4778 updatefile - Location of the software update file on a TFTP server, used
4779 by the automatic software update feature. Please refer to
4780 documentation in doc/README.update for more details.
4782 autoload - if set to "no" (any string beginning with 'n'),
4783 "bootp" will just load perform a lookup of the
4784 configuration from the BOOTP server, but not try to
4785 load any image using TFTP
4787 autostart - if set to "yes", an image loaded using the "bootp",
4788 "rarpboot", "tftpboot" or "diskboot" commands will
4789 be automatically started (by internally calling
4792 If set to "no", a standalone image passed to the
4793 "bootm" command will be copied to the load address
4794 (and eventually uncompressed), but NOT be started.
4795 This can be used to load and uncompress arbitrary
4798 fdt_high - if set this restricts the maximum address that the
4799 flattened device tree will be copied into upon boot.
4800 For example, if you have a system with 1 GB memory
4801 at physical address 0x10000000, while Linux kernel
4802 only recognizes the first 704 MB as low memory, you
4803 may need to set fdt_high as 0x3C000000 to have the
4804 device tree blob be copied to the maximum address
4805 of the 704 MB low memory, so that Linux kernel can
4806 access it during the boot procedure.
4808 If this is set to the special value 0xFFFFFFFF then
4809 the fdt will not be copied at all on boot. For this
4810 to work it must reside in writable memory, have
4811 sufficient padding on the end of it for u-boot to
4812 add the information it needs into it, and the memory
4813 must be accessible by the kernel.
4815 fdtcontroladdr- if set this is the address of the control flattened
4816 device tree used by U-Boot when CONFIG_OF_CONTROL is
4819 i2cfast - (PPC405GP|PPC405EP only)
4820 if set to 'y' configures Linux I2C driver for fast
4821 mode (400kHZ). This environment variable is used in
4822 initialization code. So, for changes to be effective
4823 it must be saved and board must be reset.
4825 initrd_high - restrict positioning of initrd images:
4826 If this variable is not set, initrd images will be
4827 copied to the highest possible address in RAM; this
4828 is usually what you want since it allows for
4829 maximum initrd size. If for some reason you want to
4830 make sure that the initrd image is loaded below the
4831 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4832 variable to a value of "no" or "off" or "0".
4833 Alternatively, you can set it to a maximum upper
4834 address to use (U-Boot will still check that it
4835 does not overwrite the U-Boot stack and data).
4837 For instance, when you have a system with 16 MB
4838 RAM, and want to reserve 4 MB from use by Linux,
4839 you can do this by adding "mem=12M" to the value of
4840 the "bootargs" variable. However, now you must make
4841 sure that the initrd image is placed in the first
4842 12 MB as well - this can be done with
4844 setenv initrd_high 00c00000
4846 If you set initrd_high to 0xFFFFFFFF, this is an
4847 indication to U-Boot that all addresses are legal
4848 for the Linux kernel, including addresses in flash
4849 memory. In this case U-Boot will NOT COPY the
4850 ramdisk at all. This may be useful to reduce the
4851 boot time on your system, but requires that this
4852 feature is supported by your Linux kernel.
4854 ipaddr - IP address; needed for tftpboot command
4856 loadaddr - Default load address for commands like "bootp",
4857 "rarpboot", "tftpboot", "loadb" or "diskboot"
4859 loads_echo - see CONFIG_LOADS_ECHO
4861 serverip - TFTP server IP address; needed for tftpboot command
4863 bootretry - see CONFIG_BOOT_RETRY_TIME
4865 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4867 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4869 ethprime - controls which interface is used first.
4871 ethact - controls which interface is currently active.
4872 For example you can do the following
4874 => setenv ethact FEC
4875 => ping 192.168.0.1 # traffic sent on FEC
4876 => setenv ethact SCC
4877 => ping 10.0.0.1 # traffic sent on SCC
4879 ethrotate - When set to "no" U-Boot does not go through all
4880 available network interfaces.
4881 It just stays at the currently selected interface.
4883 netretry - When set to "no" each network operation will
4884 either succeed or fail without retrying.
4885 When set to "once" the network operation will
4886 fail when all the available network interfaces
4887 are tried once without success.
4888 Useful on scripts which control the retry operation
4891 npe_ucode - set load address for the NPE microcode
4893 silent_linux - If set then linux will be told to boot silently, by
4894 changing the console to be empty. If "yes" it will be
4895 made silent. If "no" it will not be made silent. If
4896 unset, then it will be made silent if the U-Boot console
4899 tftpsrcport - If this is set, the value is used for TFTP's
4902 tftpdstport - If this is set, the value is used for TFTP's UDP
4903 destination port instead of the Well Know Port 69.
4905 tftpblocksize - Block size to use for TFTP transfers; if not set,
4906 we use the TFTP server's default block size
4908 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4909 seconds, minimum value is 1000 = 1 second). Defines
4910 when a packet is considered to be lost so it has to
4911 be retransmitted. The default is 5000 = 5 seconds.
4912 Lowering this value may make downloads succeed
4913 faster in networks with high packet loss rates or
4914 with unreliable TFTP servers.
4916 vlan - When set to a value < 4095 the traffic over
4917 Ethernet is encapsulated/received over 802.1q
4920 The following image location variables contain the location of images
4921 used in booting. The "Image" column gives the role of the image and is
4922 not an environment variable name. The other columns are environment
4923 variable names. "File Name" gives the name of the file on a TFTP
4924 server, "RAM Address" gives the location in RAM the image will be
4925 loaded to, and "Flash Location" gives the image's address in NOR
4926 flash or offset in NAND flash.
4928 *Note* - these variables don't have to be defined for all boards, some
4929 boards currenlty use other variables for these purposes, and some
4930 boards use these variables for other purposes.
4932 Image File Name RAM Address Flash Location
4933 ----- --------- ----------- --------------
4934 u-boot u-boot u-boot_addr_r u-boot_addr
4935 Linux kernel bootfile kernel_addr_r kernel_addr
4936 device tree blob fdtfile fdt_addr_r fdt_addr
4937 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4939 The following environment variables may be used and automatically
4940 updated by the network boot commands ("bootp" and "rarpboot"),
4941 depending the information provided by your boot server:
4943 bootfile - see above
4944 dnsip - IP address of your Domain Name Server
4945 dnsip2 - IP address of your secondary Domain Name Server
4946 gatewayip - IP address of the Gateway (Router) to use
4947 hostname - Target hostname
4949 netmask - Subnet Mask
4950 rootpath - Pathname of the root filesystem on the NFS server
4951 serverip - see above
4954 There are two special Environment Variables:
4956 serial# - contains hardware identification information such
4957 as type string and/or serial number
4958 ethaddr - Ethernet address
4960 These variables can be set only once (usually during manufacturing of
4961 the board). U-Boot refuses to delete or overwrite these variables
4962 once they have been set once.
4965 Further special Environment Variables:
4967 ver - Contains the U-Boot version string as printed
4968 with the "version" command. This variable is
4969 readonly (see CONFIG_VERSION_VARIABLE).
4972 Please note that changes to some configuration parameters may take
4973 only effect after the next boot (yes, that's just like Windoze :-).
4976 Callback functions for environment variables:
4977 ---------------------------------------------
4979 For some environment variables, the behavior of u-boot needs to change
4980 when their values are changed. This functionailty allows functions to
4981 be associated with arbitrary variables. On creation, overwrite, or
4982 deletion, the callback will provide the opportunity for some side
4983 effect to happen or for the change to be rejected.
4985 The callbacks are named and associated with a function using the
4986 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4988 These callbacks are associated with variables in one of two ways. The
4989 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4990 in the board configuration to a string that defines a list of
4991 associations. The list must be in the following format:
4993 entry = variable_name[:callback_name]
4996 If the callback name is not specified, then the callback is deleted.
4997 Spaces are also allowed anywhere in the list.
4999 Callbacks can also be associated by defining the ".callbacks" variable
5000 with the same list format above. Any association in ".callbacks" will
5001 override any association in the static list. You can define
5002 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5003 ".callbacks" envirnoment variable in the default or embedded environment.
5006 Command Line Parsing:
5007 =====================
5009 There are two different command line parsers available with U-Boot:
5010 the old "simple" one, and the much more powerful "hush" shell:
5012 Old, simple command line parser:
5013 --------------------------------
5015 - supports environment variables (through setenv / saveenv commands)
5016 - several commands on one line, separated by ';'
5017 - variable substitution using "... ${name} ..." syntax
5018 - special characters ('$', ';') can be escaped by prefixing with '\',
5020 setenv bootcmd bootm \${address}
5021 - You can also escape text by enclosing in single apostrophes, for example:
5022 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5027 - similar to Bourne shell, with control structures like
5028 if...then...else...fi, for...do...done; while...do...done,
5029 until...do...done, ...
5030 - supports environment ("global") variables (through setenv / saveenv
5031 commands) and local shell variables (through standard shell syntax
5032 "name=value"); only environment variables can be used with "run"
5038 (1) If a command line (or an environment variable executed by a "run"
5039 command) contains several commands separated by semicolon, and
5040 one of these commands fails, then the remaining commands will be
5043 (2) If you execute several variables with one call to run (i. e.
5044 calling run with a list of variables as arguments), any failing
5045 command will cause "run" to terminate, i. e. the remaining
5046 variables are not executed.
5048 Note for Redundant Ethernet Interfaces:
5049 =======================================
5051 Some boards come with redundant Ethernet interfaces; U-Boot supports
5052 such configurations and is capable of automatic selection of a
5053 "working" interface when needed. MAC assignment works as follows:
5055 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5056 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5057 "eth1addr" (=>eth1), "eth2addr", ...
5059 If the network interface stores some valid MAC address (for instance
5060 in SROM), this is used as default address if there is NO correspon-
5061 ding setting in the environment; if the corresponding environment
5062 variable is set, this overrides the settings in the card; that means:
5064 o If the SROM has a valid MAC address, and there is no address in the
5065 environment, the SROM's address is used.
5067 o If there is no valid address in the SROM, and a definition in the
5068 environment exists, then the value from the environment variable is
5071 o If both the SROM and the environment contain a MAC address, and
5072 both addresses are the same, this MAC address is used.
5074 o If both the SROM and the environment contain a MAC address, and the
5075 addresses differ, the value from the environment is used and a
5078 o If neither SROM nor the environment contain a MAC address, an error
5081 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5082 will be programmed into hardware as part of the initialization process. This
5083 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5084 The naming convention is as follows:
5085 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5090 U-Boot is capable of booting (and performing other auxiliary operations on)
5091 images in two formats:
5093 New uImage format (FIT)
5094 -----------------------
5096 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5097 to Flattened Device Tree). It allows the use of images with multiple
5098 components (several kernels, ramdisks, etc.), with contents protected by
5099 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5105 Old image format is based on binary files which can be basically anything,
5106 preceded by a special header; see the definitions in include/image.h for
5107 details; basically, the header defines the following image properties:
5109 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5110 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5111 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5112 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5114 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5115 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5116 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5117 * Compression Type (uncompressed, gzip, bzip2)
5123 The header is marked by a special Magic Number, and both the header
5124 and the data portions of the image are secured against corruption by
5131 Although U-Boot should support any OS or standalone application
5132 easily, the main focus has always been on Linux during the design of
5135 U-Boot includes many features that so far have been part of some
5136 special "boot loader" code within the Linux kernel. Also, any
5137 "initrd" images to be used are no longer part of one big Linux image;
5138 instead, kernel and "initrd" are separate images. This implementation
5139 serves several purposes:
5141 - the same features can be used for other OS or standalone
5142 applications (for instance: using compressed images to reduce the
5143 Flash memory footprint)
5145 - it becomes much easier to port new Linux kernel versions because
5146 lots of low-level, hardware dependent stuff are done by U-Boot
5148 - the same Linux kernel image can now be used with different "initrd"
5149 images; of course this also means that different kernel images can
5150 be run with the same "initrd". This makes testing easier (you don't
5151 have to build a new "zImage.initrd" Linux image when you just
5152 change a file in your "initrd"). Also, a field-upgrade of the
5153 software is easier now.
5159 Porting Linux to U-Boot based systems:
5160 ---------------------------------------
5162 U-Boot cannot save you from doing all the necessary modifications to
5163 configure the Linux device drivers for use with your target hardware
5164 (no, we don't intend to provide a full virtual machine interface to
5167 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5169 Just make sure your machine specific header file (for instance
5170 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5171 Information structure as we define in include/asm-<arch>/u-boot.h,
5172 and make sure that your definition of IMAP_ADDR uses the same value
5173 as your U-Boot configuration in CONFIG_SYS_IMMR.
5176 Configuring the Linux kernel:
5177 -----------------------------
5179 No specific requirements for U-Boot. Make sure you have some root
5180 device (initial ramdisk, NFS) for your target system.
5183 Building a Linux Image:
5184 -----------------------
5186 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5187 not used. If you use recent kernel source, a new build target
5188 "uImage" will exist which automatically builds an image usable by
5189 U-Boot. Most older kernels also have support for a "pImage" target,
5190 which was introduced for our predecessor project PPCBoot and uses a
5191 100% compatible format.
5200 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5201 encapsulate a compressed Linux kernel image with header information,
5202 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5204 * build a standard "vmlinux" kernel image (in ELF binary format):
5206 * convert the kernel into a raw binary image:
5208 ${CROSS_COMPILE}-objcopy -O binary \
5209 -R .note -R .comment \
5210 -S vmlinux linux.bin
5212 * compress the binary image:
5216 * package compressed binary image for U-Boot:
5218 mkimage -A ppc -O linux -T kernel -C gzip \
5219 -a 0 -e 0 -n "Linux Kernel Image" \
5220 -d linux.bin.gz uImage
5223 The "mkimage" tool can also be used to create ramdisk images for use
5224 with U-Boot, either separated from the Linux kernel image, or
5225 combined into one file. "mkimage" encapsulates the images with a 64
5226 byte header containing information about target architecture,
5227 operating system, image type, compression method, entry points, time
5228 stamp, CRC32 checksums, etc.
5230 "mkimage" can be called in two ways: to verify existing images and
5231 print the header information, or to build new images.
5233 In the first form (with "-l" option) mkimage lists the information
5234 contained in the header of an existing U-Boot image; this includes
5235 checksum verification:
5237 tools/mkimage -l image
5238 -l ==> list image header information
5240 The second form (with "-d" option) is used to build a U-Boot image
5241 from a "data file" which is used as image payload:
5243 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5244 -n name -d data_file image
5245 -A ==> set architecture to 'arch'
5246 -O ==> set operating system to 'os'
5247 -T ==> set image type to 'type'
5248 -C ==> set compression type 'comp'
5249 -a ==> set load address to 'addr' (hex)
5250 -e ==> set entry point to 'ep' (hex)
5251 -n ==> set image name to 'name'
5252 -d ==> use image data from 'datafile'
5254 Right now, all Linux kernels for PowerPC systems use the same load
5255 address (0x00000000), but the entry point address depends on the
5258 - 2.2.x kernels have the entry point at 0x0000000C,
5259 - 2.3.x and later kernels have the entry point at 0x00000000.
5261 So a typical call to build a U-Boot image would read:
5263 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5264 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5265 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5266 > examples/uImage.TQM850L
5267 Image Name: 2.4.4 kernel for TQM850L
5268 Created: Wed Jul 19 02:34:59 2000
5269 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5270 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5271 Load Address: 0x00000000
5272 Entry Point: 0x00000000
5274 To verify the contents of the image (or check for corruption):
5276 -> tools/mkimage -l examples/uImage.TQM850L
5277 Image Name: 2.4.4 kernel for TQM850L
5278 Created: Wed Jul 19 02:34:59 2000
5279 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5280 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5281 Load Address: 0x00000000
5282 Entry Point: 0x00000000
5284 NOTE: for embedded systems where boot time is critical you can trade
5285 speed for memory and install an UNCOMPRESSED image instead: this
5286 needs more space in Flash, but boots much faster since it does not
5287 need to be uncompressed:
5289 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5290 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5291 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5292 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5293 > examples/uImage.TQM850L-uncompressed
5294 Image Name: 2.4.4 kernel for TQM850L
5295 Created: Wed Jul 19 02:34:59 2000
5296 Image Type: PowerPC Linux Kernel Image (uncompressed)
5297 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5298 Load Address: 0x00000000
5299 Entry Point: 0x00000000
5302 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5303 when your kernel is intended to use an initial ramdisk:
5305 -> tools/mkimage -n 'Simple Ramdisk Image' \
5306 > -A ppc -O linux -T ramdisk -C gzip \
5307 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5308 Image Name: Simple Ramdisk Image
5309 Created: Wed Jan 12 14:01:50 2000
5310 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5311 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5312 Load Address: 0x00000000
5313 Entry Point: 0x00000000
5315 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5316 option performs the converse operation of the mkimage's second form (the "-d"
5317 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5320 tools/dumpimage -i image -p position data_file
5321 -i ==> extract from the 'image' a specific 'data_file', \
5322 indexed by 'position'
5325 Installing a Linux Image:
5326 -------------------------
5328 To downloading a U-Boot image over the serial (console) interface,
5329 you must convert the image to S-Record format:
5331 objcopy -I binary -O srec examples/image examples/image.srec
5333 The 'objcopy' does not understand the information in the U-Boot
5334 image header, so the resulting S-Record file will be relative to
5335 address 0x00000000. To load it to a given address, you need to
5336 specify the target address as 'offset' parameter with the 'loads'
5339 Example: install the image to address 0x40100000 (which on the
5340 TQM8xxL is in the first Flash bank):
5342 => erase 40100000 401FFFFF
5348 ## Ready for S-Record download ...
5349 ~>examples/image.srec
5350 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5352 15989 15990 15991 15992
5353 [file transfer complete]
5355 ## Start Addr = 0x00000000
5358 You can check the success of the download using the 'iminfo' command;
5359 this includes a checksum verification so you can be sure no data
5360 corruption happened:
5364 ## Checking Image at 40100000 ...
5365 Image Name: 2.2.13 for initrd on TQM850L
5366 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5367 Data Size: 335725 Bytes = 327 kB = 0 MB
5368 Load Address: 00000000
5369 Entry Point: 0000000c
5370 Verifying Checksum ... OK
5376 The "bootm" command is used to boot an application that is stored in
5377 memory (RAM or Flash). In case of a Linux kernel image, the contents
5378 of the "bootargs" environment variable is passed to the kernel as
5379 parameters. You can check and modify this variable using the
5380 "printenv" and "setenv" commands:
5383 => printenv bootargs
5384 bootargs=root=/dev/ram
5386 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5388 => printenv bootargs
5389 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5392 ## Booting Linux kernel at 40020000 ...
5393 Image Name: 2.2.13 for NFS on TQM850L
5394 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5395 Data Size: 381681 Bytes = 372 kB = 0 MB
5396 Load Address: 00000000
5397 Entry Point: 0000000c
5398 Verifying Checksum ... OK
5399 Uncompressing Kernel Image ... OK
5400 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
5401 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5402 time_init: decrementer frequency = 187500000/60
5403 Calibrating delay loop... 49.77 BogoMIPS
5404 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5407 If you want to boot a Linux kernel with initial RAM disk, you pass
5408 the memory addresses of both the kernel and the initrd image (PPBCOOT
5409 format!) to the "bootm" command:
5411 => imi 40100000 40200000
5413 ## Checking Image at 40100000 ...
5414 Image Name: 2.2.13 for initrd on TQM850L
5415 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5416 Data Size: 335725 Bytes = 327 kB = 0 MB
5417 Load Address: 00000000
5418 Entry Point: 0000000c
5419 Verifying Checksum ... OK
5421 ## Checking Image at 40200000 ...
5422 Image Name: Simple Ramdisk Image
5423 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5424 Data Size: 566530 Bytes = 553 kB = 0 MB
5425 Load Address: 00000000
5426 Entry Point: 00000000
5427 Verifying Checksum ... OK
5429 => bootm 40100000 40200000
5430 ## Booting Linux kernel at 40100000 ...
5431 Image Name: 2.2.13 for initrd on TQM850L
5432 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5433 Data Size: 335725 Bytes = 327 kB = 0 MB
5434 Load Address: 00000000
5435 Entry Point: 0000000c
5436 Verifying Checksum ... OK
5437 Uncompressing Kernel Image ... OK
5438 ## Loading RAMDisk Image at 40200000 ...
5439 Image Name: Simple Ramdisk Image
5440 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5441 Data Size: 566530 Bytes = 553 kB = 0 MB
5442 Load Address: 00000000
5443 Entry Point: 00000000
5444 Verifying Checksum ... OK
5445 Loading Ramdisk ... OK
5446 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
5447 Boot arguments: root=/dev/ram
5448 time_init: decrementer frequency = 187500000/60
5449 Calibrating delay loop... 49.77 BogoMIPS
5451 RAMDISK: Compressed image found at block 0
5452 VFS: Mounted root (ext2 filesystem).
5456 Boot Linux and pass a flat device tree:
5459 First, U-Boot must be compiled with the appropriate defines. See the section
5460 titled "Linux Kernel Interface" above for a more in depth explanation. The
5461 following is an example of how to start a kernel and pass an updated
5467 oft=oftrees/mpc8540ads.dtb
5468 => tftp $oftaddr $oft
5469 Speed: 1000, full duplex
5471 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5472 Filename 'oftrees/mpc8540ads.dtb'.
5473 Load address: 0x300000
5476 Bytes transferred = 4106 (100a hex)
5477 => tftp $loadaddr $bootfile
5478 Speed: 1000, full duplex
5480 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5482 Load address: 0x200000
5483 Loading:############
5485 Bytes transferred = 1029407 (fb51f hex)
5490 => bootm $loadaddr - $oftaddr
5491 ## Booting image at 00200000 ...
5492 Image Name: Linux-2.6.17-dirty
5493 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5494 Data Size: 1029343 Bytes = 1005.2 kB
5495 Load Address: 00000000
5496 Entry Point: 00000000
5497 Verifying Checksum ... OK
5498 Uncompressing Kernel Image ... OK
5499 Booting using flat device tree at 0x300000
5500 Using MPC85xx ADS machine description
5501 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5505 More About U-Boot Image Types:
5506 ------------------------------
5508 U-Boot supports the following image types:
5510 "Standalone Programs" are directly runnable in the environment
5511 provided by U-Boot; it is expected that (if they behave
5512 well) you can continue to work in U-Boot after return from
5513 the Standalone Program.
5514 "OS Kernel Images" are usually images of some Embedded OS which
5515 will take over control completely. Usually these programs
5516 will install their own set of exception handlers, device
5517 drivers, set up the MMU, etc. - this means, that you cannot
5518 expect to re-enter U-Boot except by resetting the CPU.
5519 "RAMDisk Images" are more or less just data blocks, and their
5520 parameters (address, size) are passed to an OS kernel that is
5522 "Multi-File Images" contain several images, typically an OS
5523 (Linux) kernel image and one or more data images like
5524 RAMDisks. This construct is useful for instance when you want
5525 to boot over the network using BOOTP etc., where the boot
5526 server provides just a single image file, but you want to get
5527 for instance an OS kernel and a RAMDisk image.
5529 "Multi-File Images" start with a list of image sizes, each
5530 image size (in bytes) specified by an "uint32_t" in network
5531 byte order. This list is terminated by an "(uint32_t)0".
5532 Immediately after the terminating 0 follow the images, one by
5533 one, all aligned on "uint32_t" boundaries (size rounded up to
5534 a multiple of 4 bytes).
5536 "Firmware Images" are binary images containing firmware (like
5537 U-Boot or FPGA images) which usually will be programmed to
5540 "Script files" are command sequences that will be executed by
5541 U-Boot's command interpreter; this feature is especially
5542 useful when you configure U-Boot to use a real shell (hush)
5543 as command interpreter.
5545 Booting the Linux zImage:
5546 -------------------------
5548 On some platforms, it's possible to boot Linux zImage. This is done
5549 using the "bootz" command. The syntax of "bootz" command is the same
5550 as the syntax of "bootm" command.
5552 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5553 kernel with raw initrd images. The syntax is slightly different, the
5554 address of the initrd must be augmented by it's size, in the following
5555 format: "<initrd addres>:<initrd size>".
5561 One of the features of U-Boot is that you can dynamically load and
5562 run "standalone" applications, which can use some resources of
5563 U-Boot like console I/O functions or interrupt services.
5565 Two simple examples are included with the sources:
5570 'examples/hello_world.c' contains a small "Hello World" Demo
5571 application; it is automatically compiled when you build U-Boot.
5572 It's configured to run at address 0x00040004, so you can play with it
5576 ## Ready for S-Record download ...
5577 ~>examples/hello_world.srec
5578 1 2 3 4 5 6 7 8 9 10 11 ...
5579 [file transfer complete]
5581 ## Start Addr = 0x00040004
5583 => go 40004 Hello World! This is a test.
5584 ## Starting application at 0x00040004 ...
5595 Hit any key to exit ...
5597 ## Application terminated, rc = 0x0
5599 Another example, which demonstrates how to register a CPM interrupt
5600 handler with the U-Boot code, can be found in 'examples/timer.c'.
5601 Here, a CPM timer is set up to generate an interrupt every second.
5602 The interrupt service routine is trivial, just printing a '.'
5603 character, but this is just a demo program. The application can be
5604 controlled by the following keys:
5606 ? - print current values og the CPM Timer registers
5607 b - enable interrupts and start timer
5608 e - stop timer and disable interrupts
5609 q - quit application
5612 ## Ready for S-Record download ...
5613 ~>examples/timer.srec
5614 1 2 3 4 5 6 7 8 9 10 11 ...
5615 [file transfer complete]
5617 ## Start Addr = 0x00040004
5620 ## Starting application at 0x00040004 ...
5623 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5626 [q, b, e, ?] Set interval 1000000 us
5629 [q, b, e, ?] ........
5630 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5633 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5636 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5639 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5641 [q, b, e, ?] ...Stopping timer
5643 [q, b, e, ?] ## Application terminated, rc = 0x0
5649 Over time, many people have reported problems when trying to use the
5650 "minicom" terminal emulation program for serial download. I (wd)
5651 consider minicom to be broken, and recommend not to use it. Under
5652 Unix, I recommend to use C-Kermit for general purpose use (and
5653 especially for kermit binary protocol download ("loadb" command), and
5654 use "cu" for S-Record download ("loads" command). See
5655 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5656 for help with kermit.
5659 Nevertheless, if you absolutely want to use it try adding this
5660 configuration to your "File transfer protocols" section:
5662 Name Program Name U/D FullScr IO-Red. Multi
5663 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5664 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5670 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5671 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5673 Building requires a cross environment; it is known to work on
5674 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5675 need gmake since the Makefiles are not compatible with BSD make).
5676 Note that the cross-powerpc package does not install include files;
5677 attempting to build U-Boot will fail because <machine/ansi.h> is
5678 missing. This file has to be installed and patched manually:
5680 # cd /usr/pkg/cross/powerpc-netbsd/include
5682 # ln -s powerpc machine
5683 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5684 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5686 Native builds *don't* work due to incompatibilities between native
5687 and U-Boot include files.
5689 Booting assumes that (the first part of) the image booted is a
5690 stage-2 loader which in turn loads and then invokes the kernel
5691 proper. Loader sources will eventually appear in the NetBSD source
5692 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5693 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5696 Implementation Internals:
5697 =========================
5699 The following is not intended to be a complete description of every
5700 implementation detail. However, it should help to understand the
5701 inner workings of U-Boot and make it easier to port it to custom
5705 Initial Stack, Global Data:
5706 ---------------------------
5708 The implementation of U-Boot is complicated by the fact that U-Boot
5709 starts running out of ROM (flash memory), usually without access to
5710 system RAM (because the memory controller is not initialized yet).
5711 This means that we don't have writable Data or BSS segments, and BSS
5712 is not initialized as zero. To be able to get a C environment working
5713 at all, we have to allocate at least a minimal stack. Implementation
5714 options for this are defined and restricted by the CPU used: Some CPU
5715 models provide on-chip memory (like the IMMR area on MPC8xx and
5716 MPC826x processors), on others (parts of) the data cache can be
5717 locked as (mis-) used as memory, etc.
5719 Chris Hallinan posted a good summary of these issues to the
5720 U-Boot mailing list:
5722 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5723 From: "Chris Hallinan" <clh@net1plus.com>
5724 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5727 Correct me if I'm wrong, folks, but the way I understand it
5728 is this: Using DCACHE as initial RAM for Stack, etc, does not
5729 require any physical RAM backing up the cache. The cleverness
5730 is that the cache is being used as a temporary supply of
5731 necessary storage before the SDRAM controller is setup. It's
5732 beyond the scope of this list to explain the details, but you
5733 can see how this works by studying the cache architecture and
5734 operation in the architecture and processor-specific manuals.
5736 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5737 is another option for the system designer to use as an
5738 initial stack/RAM area prior to SDRAM being available. Either
5739 option should work for you. Using CS 4 should be fine if your
5740 board designers haven't used it for something that would
5741 cause you grief during the initial boot! It is frequently not
5744 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5745 with your processor/board/system design. The default value
5746 you will find in any recent u-boot distribution in
5747 walnut.h should work for you. I'd set it to a value larger
5748 than your SDRAM module. If you have a 64MB SDRAM module, set
5749 it above 400_0000. Just make sure your board has no resources
5750 that are supposed to respond to that address! That code in
5751 start.S has been around a while and should work as is when
5752 you get the config right.
5757 It is essential to remember this, since it has some impact on the C
5758 code for the initialization procedures:
5760 * Initialized global data (data segment) is read-only. Do not attempt
5763 * Do not use any uninitialized global data (or implicitely initialized
5764 as zero data - BSS segment) at all - this is undefined, initiali-
5765 zation is performed later (when relocating to RAM).
5767 * Stack space is very limited. Avoid big data buffers or things like
5770 Having only the stack as writable memory limits means we cannot use
5771 normal global data to share information beween the code. But it
5772 turned out that the implementation of U-Boot can be greatly
5773 simplified by making a global data structure (gd_t) available to all
5774 functions. We could pass a pointer to this data as argument to _all_
5775 functions, but this would bloat the code. Instead we use a feature of
5776 the GCC compiler (Global Register Variables) to share the data: we
5777 place a pointer (gd) to the global data into a register which we
5778 reserve for this purpose.
5780 When choosing a register for such a purpose we are restricted by the
5781 relevant (E)ABI specifications for the current architecture, and by
5782 GCC's implementation.
5784 For PowerPC, the following registers have specific use:
5786 R2: reserved for system use
5787 R3-R4: parameter passing and return values
5788 R5-R10: parameter passing
5789 R13: small data area pointer
5793 (U-Boot also uses R12 as internal GOT pointer. r12
5794 is a volatile register so r12 needs to be reset when
5795 going back and forth between asm and C)
5797 ==> U-Boot will use R2 to hold a pointer to the global data
5799 Note: on PPC, we could use a static initializer (since the
5800 address of the global data structure is known at compile time),
5801 but it turned out that reserving a register results in somewhat
5802 smaller code - although the code savings are not that big (on
5803 average for all boards 752 bytes for the whole U-Boot image,
5804 624 text + 127 data).
5806 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5807 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5809 ==> U-Boot will use P3 to hold a pointer to the global data
5811 On ARM, the following registers are used:
5813 R0: function argument word/integer result
5814 R1-R3: function argument word
5815 R9: platform specific
5816 R10: stack limit (used only if stack checking is enabled)
5817 R11: argument (frame) pointer
5818 R12: temporary workspace
5821 R15: program counter
5823 ==> U-Boot will use R9 to hold a pointer to the global data
5825 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5827 On Nios II, the ABI is documented here:
5828 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5830 ==> U-Boot will use gp to hold a pointer to the global data
5832 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5833 to access small data sections, so gp is free.
5835 On NDS32, the following registers are used:
5837 R0-R1: argument/return
5839 R15: temporary register for assembler
5840 R16: trampoline register
5841 R28: frame pointer (FP)
5842 R29: global pointer (GP)
5843 R30: link register (LP)
5844 R31: stack pointer (SP)
5845 PC: program counter (PC)
5847 ==> U-Boot will use R10 to hold a pointer to the global data
5849 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5850 or current versions of GCC may "optimize" the code too much.
5855 U-Boot runs in system state and uses physical addresses, i.e. the
5856 MMU is not used either for address mapping nor for memory protection.
5858 The available memory is mapped to fixed addresses using the memory
5859 controller. In this process, a contiguous block is formed for each
5860 memory type (Flash, SDRAM, SRAM), even when it consists of several
5861 physical memory banks.
5863 U-Boot is installed in the first 128 kB of the first Flash bank (on
5864 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5865 booting and sizing and initializing DRAM, the code relocates itself
5866 to the upper end of DRAM. Immediately below the U-Boot code some
5867 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5868 configuration setting]. Below that, a structure with global Board
5869 Info data is placed, followed by the stack (growing downward).
5871 Additionally, some exception handler code is copied to the low 8 kB
5872 of DRAM (0x00000000 ... 0x00001FFF).
5874 So a typical memory configuration with 16 MB of DRAM could look like
5877 0x0000 0000 Exception Vector code
5880 0x0000 2000 Free for Application Use
5886 0x00FB FF20 Monitor Stack (Growing downward)
5887 0x00FB FFAC Board Info Data and permanent copy of global data
5888 0x00FC 0000 Malloc Arena
5891 0x00FE 0000 RAM Copy of Monitor Code
5892 ... eventually: LCD or video framebuffer
5893 ... eventually: pRAM (Protected RAM - unchanged by reset)
5894 0x00FF FFFF [End of RAM]
5897 System Initialization:
5898 ----------------------
5900 In the reset configuration, U-Boot starts at the reset entry point
5901 (on most PowerPC systems at address 0x00000100). Because of the reset
5902 configuration for CS0# this is a mirror of the onboard Flash memory.
5903 To be able to re-map memory U-Boot then jumps to its link address.
5904 To be able to implement the initialization code in C, a (small!)
5905 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5906 which provide such a feature like MPC8xx or MPC8260), or in a locked
5907 part of the data cache. After that, U-Boot initializes the CPU core,
5908 the caches and the SIU.
5910 Next, all (potentially) available memory banks are mapped using a
5911 preliminary mapping. For example, we put them on 512 MB boundaries
5912 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5913 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5914 programmed for SDRAM access. Using the temporary configuration, a
5915 simple memory test is run that determines the size of the SDRAM
5918 When there is more than one SDRAM bank, and the banks are of
5919 different size, the largest is mapped first. For equal size, the first
5920 bank (CS2#) is mapped first. The first mapping is always for address
5921 0x00000000, with any additional banks following immediately to create
5922 contiguous memory starting from 0.
5924 Then, the monitor installs itself at the upper end of the SDRAM area
5925 and allocates memory for use by malloc() and for the global Board
5926 Info data; also, the exception vector code is copied to the low RAM
5927 pages, and the final stack is set up.
5929 Only after this relocation will you have a "normal" C environment;
5930 until that you are restricted in several ways, mostly because you are
5931 running from ROM, and because the code will have to be relocated to a
5935 U-Boot Porting Guide:
5936 ----------------------
5938 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5942 int main(int argc, char *argv[])
5944 sighandler_t no_more_time;
5946 signal(SIGALRM, no_more_time);
5947 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5949 if (available_money > available_manpower) {
5950 Pay consultant to port U-Boot;
5954 Download latest U-Boot source;
5956 Subscribe to u-boot mailing list;
5959 email("Hi, I am new to U-Boot, how do I get started?");
5962 Read the README file in the top level directory;
5963 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5964 Read applicable doc/*.README;
5965 Read the source, Luke;
5966 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5969 if (available_money > toLocalCurrency ($2500))
5972 Add a lot of aggravation and time;
5974 if (a similar board exists) { /* hopefully... */
5975 cp -a board/<similar> board/<myboard>
5976 cp include/configs/<similar>.h include/configs/<myboard>.h
5978 Create your own board support subdirectory;
5979 Create your own board include/configs/<myboard>.h file;
5981 Edit new board/<myboard> files
5982 Edit new include/configs/<myboard>.h
5987 Add / modify source code;
5991 email("Hi, I am having problems...");
5993 Send patch file to the U-Boot email list;
5994 if (reasonable critiques)
5995 Incorporate improvements from email list code review;
5997 Defend code as written;
6003 void no_more_time (int sig)
6012 All contributions to U-Boot should conform to the Linux kernel
6013 coding style; see the file "Documentation/CodingStyle" and the script
6014 "scripts/Lindent" in your Linux kernel source directory.
6016 Source files originating from a different project (for example the
6017 MTD subsystem) are generally exempt from these guidelines and are not
6018 reformated to ease subsequent migration to newer versions of those
6021 Please note that U-Boot is implemented in C (and to some small parts in
6022 Assembler); no C++ is used, so please do not use C++ style comments (//)
6025 Please also stick to the following formatting rules:
6026 - remove any trailing white space
6027 - use TAB characters for indentation and vertical alignment, not spaces
6028 - make sure NOT to use DOS '\r\n' line feeds
6029 - do not add more than 2 consecutive empty lines to source files
6030 - do not add trailing empty lines to source files
6032 Submissions which do not conform to the standards may be returned
6033 with a request to reformat the changes.
6039 Since the number of patches for U-Boot is growing, we need to
6040 establish some rules. Submissions which do not conform to these rules
6041 may be rejected, even when they contain important and valuable stuff.
6043 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6045 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6046 see http://lists.denx.de/mailman/listinfo/u-boot
6048 When you send a patch, please include the following information with
6051 * For bug fixes: a description of the bug and how your patch fixes
6052 this bug. Please try to include a way of demonstrating that the
6053 patch actually fixes something.
6055 * For new features: a description of the feature and your
6058 * A CHANGELOG entry as plaintext (separate from the patch)
6060 * For major contributions, your entry to the CREDITS file
6062 * When you add support for a new board, don't forget to add a
6063 maintainer e-mail address to the boards.cfg file, too.
6065 * If your patch adds new configuration options, don't forget to
6066 document these in the README file.
6068 * The patch itself. If you are using git (which is *strongly*
6069 recommended) you can easily generate the patch using the
6070 "git format-patch". If you then use "git send-email" to send it to
6071 the U-Boot mailing list, you will avoid most of the common problems
6072 with some other mail clients.
6074 If you cannot use git, use "diff -purN OLD NEW". If your version of
6075 diff does not support these options, then get the latest version of
6078 The current directory when running this command shall be the parent
6079 directory of the U-Boot source tree (i. e. please make sure that
6080 your patch includes sufficient directory information for the
6083 We prefer patches as plain text. MIME attachments are discouraged,
6084 and compressed attachments must not be used.
6086 * If one logical set of modifications affects or creates several
6087 files, all these changes shall be submitted in a SINGLE patch file.
6089 * Changesets that contain different, unrelated modifications shall be
6090 submitted as SEPARATE patches, one patch per changeset.
6095 * Before sending the patch, run the MAKEALL script on your patched
6096 source tree and make sure that no errors or warnings are reported
6097 for any of the boards.
6099 * Keep your modifications to the necessary minimum: A patch
6100 containing several unrelated changes or arbitrary reformats will be
6101 returned with a request to re-formatting / split it.
6103 * If you modify existing code, make sure that your new code does not
6104 add to the memory footprint of the code ;-) Small is beautiful!
6105 When adding new features, these should compile conditionally only
6106 (using #ifdef), and the resulting code with the new feature
6107 disabled must not need more memory than the old code without your
6110 * Remember that there is a size limit of 100 kB per message on the
6111 u-boot mailing list. Bigger patches will be moderated. If they are
6112 reasonable and not too big, they will be acknowledged. But patches
6113 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob