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 /ixp Files specific to Intel XScale IXP CPUs
145 /pxa Files specific to Intel XScale PXA CPUs
146 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
147 /lib Architecture specific library files
148 /avr32 Files generic to AVR32 architecture
149 /cpu CPU specific files
150 /lib Architecture specific library files
151 /blackfin Files generic to Analog Devices Blackfin architecture
152 /cpu CPU specific files
153 /lib Architecture specific library files
154 /m68k Files generic to m68k architecture
155 /cpu CPU specific files
156 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 /lib Architecture specific library files
162 /microblaze Files generic to microblaze architecture
163 /cpu CPU specific files
164 /lib Architecture specific library files
165 /mips Files generic to MIPS architecture
166 /cpu CPU specific files
167 /mips32 Files specific to MIPS32 CPUs
168 /xburst Files specific to Ingenic XBurst CPUs
169 /lib Architecture specific library files
170 /nds32 Files generic to NDS32 architecture
171 /cpu CPU specific files
172 /n1213 Files specific to Andes Technology N1213 CPUs
173 /lib Architecture specific library files
174 /nios2 Files generic to Altera NIOS2 architecture
175 /cpu CPU specific files
176 /lib Architecture specific library files
177 /openrisc Files generic to OpenRISC architecture
178 /cpu CPU specific files
179 /lib Architecture specific library files
180 /powerpc Files generic to PowerPC architecture
181 /cpu CPU specific files
182 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
183 /mpc5xx Files specific to Freescale MPC5xx CPUs
184 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
185 /mpc8xx Files specific to Freescale MPC8xx CPUs
186 /mpc824x Files specific to Freescale MPC824x CPUs
187 /mpc8260 Files specific to Freescale MPC8260 CPUs
188 /mpc85xx Files specific to Freescale MPC85xx CPUs
189 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
190 /lib Architecture specific library files
191 /sh Files generic to SH architecture
192 /cpu CPU specific files
193 /sh2 Files specific to sh2 CPUs
194 /sh3 Files specific to sh3 CPUs
195 /sh4 Files specific to sh4 CPUs
196 /lib Architecture specific library files
197 /sparc Files generic to SPARC architecture
198 /cpu CPU specific files
199 /leon2 Files specific to Gaisler LEON2 SPARC CPU
200 /leon3 Files specific to Gaisler LEON3 SPARC CPU
201 /lib Architecture specific library files
202 /x86 Files generic to x86 architecture
203 /cpu CPU specific files
204 /lib Architecture specific library files
205 /api Machine/arch independent API for external apps
206 /board Board dependent files
207 /common Misc architecture independent functions
208 /disk Code for disk drive partition handling
209 /doc Documentation (don't expect too much)
210 /drivers Commonly used device drivers
211 /dts Contains Makefile for building internal U-Boot fdt.
212 /examples Example code for standalone applications, etc.
213 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
214 /include Header Files
215 /lib Files generic to all architectures
216 /libfdt Library files to support flattened device trees
217 /lzma Library files to support LZMA decompression
218 /lzo Library files to support LZO decompression
220 /post Power On Self Test
221 /spl Secondary Program Loader framework
222 /tools Tools to build S-Record or U-Boot images, etc.
224 Software Configuration:
225 =======================
227 Configuration is usually done using C preprocessor defines; the
228 rationale behind that is to avoid dead code whenever possible.
230 There are two classes of configuration variables:
232 * Configuration _OPTIONS_:
233 These are selectable by the user and have names beginning with
236 * Configuration _SETTINGS_:
237 These depend on the hardware etc. and should not be meddled with if
238 you don't know what you're doing; they have names beginning with
241 Later we will add a configuration tool - probably similar to or even
242 identical to what's used for the Linux kernel. Right now, we have to
243 do the configuration by hand, which means creating some symbolic
244 links and editing some configuration files. We use the TQM8xxL boards
248 Selection of Processor Architecture and Board Type:
249 ---------------------------------------------------
251 For all supported boards there are ready-to-use default
252 configurations available; just type "make <board_name>_config".
254 Example: For a TQM823L module type:
259 For the Cogent platform, you need to specify the CPU type as well;
260 e.g. "make cogent_mpc8xx_config". And also configure the cogent
261 directory according to the instructions in cogent/README.
264 Configuration Options:
265 ----------------------
267 Configuration depends on the combination of board and CPU type; all
268 such information is kept in a configuration file
269 "include/configs/<board_name>.h".
271 Example: For a TQM823L module, all configuration settings are in
272 "include/configs/TQM823L.h".
275 Many of the options are named exactly as the corresponding Linux
276 kernel configuration options. The intention is to make it easier to
277 build a config tool - later.
280 The following options need to be configured:
282 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
284 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
286 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
287 Define exactly one, e.g. CONFIG_ATSTK1002
289 - CPU Module Type: (if CONFIG_COGENT is defined)
290 Define exactly one of
292 --- FIXME --- not tested yet:
293 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
294 CONFIG_CMA287_23, CONFIG_CMA287_50
296 - Motherboard Type: (if CONFIG_COGENT is defined)
297 Define exactly one of
298 CONFIG_CMA101, CONFIG_CMA102
300 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
301 Define one or more of
304 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
305 Define one or more of
306 CONFIG_LCD_HEARTBEAT - update a character position on
307 the LCD display every second with
310 - Board flavour: (if CONFIG_MPC8260ADS is defined)
313 CONFIG_SYS_8260ADS - original MPC8260ADS
314 CONFIG_SYS_8266ADS - MPC8266ADS
315 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
316 CONFIG_SYS_8272ADS - MPC8272ADS
318 - Marvell Family Member
319 CONFIG_SYS_MVFS - define it if you want to enable
320 multiple fs option at one time
321 for marvell soc family
323 - MPC824X Family Member (if CONFIG_MPC824X is defined)
324 Define exactly one of
325 CONFIG_MPC8240, CONFIG_MPC8245
327 - 8xx CPU Options: (if using an MPC8xx CPU)
328 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
329 get_gclk_freq() cannot work
330 e.g. if there is no 32KHz
331 reference PIT/RTC clock
332 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
335 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
336 CONFIG_SYS_8xx_CPUCLK_MIN
337 CONFIG_SYS_8xx_CPUCLK_MAX
338 CONFIG_8xx_CPUCLK_DEFAULT
339 See doc/README.MPC866
341 CONFIG_SYS_MEASURE_CPUCLK
343 Define this to measure the actual CPU clock instead
344 of relying on the correctness of the configured
345 values. Mostly useful for board bringup to make sure
346 the PLL is locked at the intended frequency. Note
347 that this requires a (stable) reference clock (32 kHz
348 RTC clock or CONFIG_SYS_8XX_XIN)
350 CONFIG_SYS_DELAYED_ICACHE
352 Define this option if you want to enable the
353 ICache only when Code runs from RAM.
358 Specifies that the core is a 64-bit PowerPC implementation (implements
359 the "64" category of the Power ISA). This is necessary for ePAPR
360 compliance, among other possible reasons.
362 CONFIG_SYS_FSL_TBCLK_DIV
364 Defines the core time base clock divider ratio compared to the
365 system clock. On most PQ3 devices this is 8, on newer QorIQ
366 devices it can be 16 or 32. The ratio varies from SoC to Soc.
368 CONFIG_SYS_FSL_PCIE_COMPAT
370 Defines the string to utilize when trying to match PCIe device
371 tree nodes for the given platform.
373 CONFIG_SYS_PPC_E500_DEBUG_TLB
375 Enables a temporary TLB entry to be used during boot to work
376 around limitations in e500v1 and e500v2 external debugger
377 support. This reduces the portions of the boot code where
378 breakpoints and single stepping do not work. The value of this
379 symbol should be set to the TLB1 entry to be used for this
382 CONFIG_SYS_FSL_ERRATUM_A004510
384 Enables a workaround for erratum A004510. If set,
385 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
386 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
389 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
391 Defines one or two SoC revisions (low 8 bits of SVR)
392 for which the A004510 workaround should be applied.
394 The rest of SVR is either not relevant to the decision
395 of whether the erratum is present (e.g. p2040 versus
396 p2041) or is implied by the build target, which controls
397 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
399 See Freescale App Note 4493 for more information about
402 CONFIG_A003399_NOR_WORKAROUND
403 Enables a workaround for IFC erratum A003399. It is only
404 requred during NOR boot.
406 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
408 This is the value to write into CCSR offset 0x18600
409 according to the A004510 workaround.
411 CONFIG_SYS_FSL_DSP_DDR_ADDR
412 This value denotes start offset of DDR memory which is
413 connected exclusively to the DSP cores.
415 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
416 This value denotes start offset of M2 memory
417 which is directly connected to the DSP core.
419 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
420 This value denotes start offset of M3 memory which is directly
421 connected to the DSP core.
423 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
424 This value denotes start offset of DSP CCSR space.
426 - Generic CPU options:
427 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
429 Defines the endianess of the CPU. Implementation of those
430 values is arch specific.
433 Freescale DDR driver in use. This type of DDR controller is
434 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
437 CONFIG_SYS_FSL_DDR_ADDR
438 Freescale DDR memory-mapped register base.
440 CONFIG_SYS_FSL_DDR_EMU
441 Specify emulator support for DDR. Some DDR features such as
442 deskew training are not available.
444 CONFIG_SYS_FSL_DDRC_GEN1
445 Freescale DDR1 controller.
447 CONFIG_SYS_FSL_DDRC_GEN2
448 Freescale DDR2 controller.
450 CONFIG_SYS_FSL_DDRC_GEN3
451 Freescale DDR3 controller.
454 Board config to use DDR1. It can be enabled for SoCs with
455 Freescale DDR1 or DDR2 controllers, depending on the board
459 Board config to use DDR2. It can be eanbeld for SoCs with
460 Freescale DDR2 or DDR3 controllers, depending on the board
464 Board config to use DDR3. It can be enabled for SoCs with
465 Freescale DDR3 controllers.
467 - Intel Monahans options:
468 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
470 Defines the Monahans run mode to oscillator
471 ratio. Valid values are 8, 16, 24, 31. The core
472 frequency is this value multiplied by 13 MHz.
474 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
476 Defines the Monahans turbo mode to oscillator
477 ratio. Valid values are 1 (default if undefined) and
478 2. The core frequency as calculated above is multiplied
482 CONFIG_SYS_INIT_SP_OFFSET
484 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
485 pointer. This is needed for the temporary stack before
488 CONFIG_SYS_MIPS_CACHE_MODE
490 Cache operation mode for the MIPS CPU.
491 See also arch/mips/include/asm/mipsregs.h.
493 CONF_CM_CACHABLE_NO_WA
496 CONF_CM_CACHABLE_NONCOHERENT
500 CONF_CM_CACHABLE_ACCELERATED
502 CONFIG_SYS_XWAY_EBU_BOOTCFG
504 Special option for Lantiq XWAY SoCs for booting from NOR flash.
505 See also arch/mips/cpu/mips32/start.S.
507 CONFIG_XWAY_SWAP_BYTES
509 Enable compilation of tools/xway-swap-bytes needed for Lantiq
510 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
511 be swapped if a flash programmer is used.
514 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
516 Select high exception vectors of the ARM core, e.g., do not
517 clear the V bit of the c1 register of CP15.
519 CONFIG_SYS_THUMB_BUILD
521 Use this flag to build U-Boot using the Thumb instruction
522 set for ARM architectures. Thumb instruction set provides
523 better code density. For ARM architectures that support
524 Thumb2 this flag will result in Thumb2 code generated by
527 CONFIG_ARM_ERRATA_716044
528 CONFIG_ARM_ERRATA_742230
529 CONFIG_ARM_ERRATA_743622
530 CONFIG_ARM_ERRATA_751472
532 If set, the workarounds for these ARM errata are applied early
533 during U-Boot startup. Note that these options force the
534 workarounds to be applied; no CPU-type/version detection
535 exists, unlike the similar options in the Linux kernel. Do not
536 set these options unless they apply!
541 The frequency of the timer returned by get_timer().
542 get_timer() must operate in milliseconds and this CONFIG
543 option must be set to 1000.
545 - Linux Kernel Interface:
548 U-Boot stores all clock information in Hz
549 internally. For binary compatibility with older Linux
550 kernels (which expect the clocks passed in the
551 bd_info data to be in MHz) the environment variable
552 "clocks_in_mhz" can be defined so that U-Boot
553 converts clock data to MHZ before passing it to the
555 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
556 "clocks_in_mhz=1" is automatically included in the
559 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
561 When transferring memsize parameter to linux, some versions
562 expect it to be in bytes, others in MB.
563 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
567 New kernel versions are expecting firmware settings to be
568 passed using flattened device trees (based on open firmware
572 * New libfdt-based support
573 * Adds the "fdt" command
574 * The bootm command automatically updates the fdt
576 OF_CPU - The proper name of the cpus node (only required for
577 MPC512X and MPC5xxx based boards).
578 OF_SOC - The proper name of the soc node (only required for
579 MPC512X and MPC5xxx based boards).
580 OF_TBCLK - The timebase frequency.
581 OF_STDOUT_PATH - The path to the console device
583 boards with QUICC Engines require OF_QE to set UCC MAC
586 CONFIG_OF_BOARD_SETUP
588 Board code has addition modification that it wants to make
589 to the flat device tree before handing it off to the kernel
593 This define fills in the correct boot CPU in the boot
594 param header, the default value is zero if undefined.
598 U-Boot can detect if an IDE device is present or not.
599 If not, and this new config option is activated, U-Boot
600 removes the ATA node from the DTS before booting Linux,
601 so the Linux IDE driver does not probe the device and
602 crash. This is needed for buggy hardware (uc101) where
603 no pull down resistor is connected to the signal IDE5V_DD7.
605 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
607 This setting is mandatory for all boards that have only one
608 machine type and must be used to specify the machine type
609 number as it appears in the ARM machine registry
610 (see http://www.arm.linux.org.uk/developer/machines/).
611 Only boards that have multiple machine types supported
612 in a single configuration file and the machine type is
613 runtime discoverable, do not have to use this setting.
615 - vxWorks boot parameters:
617 bootvx constructs a valid bootline using the following
618 environments variables: bootfile, ipaddr, serverip, hostname.
619 It loads the vxWorks image pointed bootfile.
621 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
622 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
623 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
624 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
626 CONFIG_SYS_VXWORKS_ADD_PARAMS
628 Add it at the end of the bootline. E.g "u=username pw=secret"
630 Note: If a "bootargs" environment is defined, it will overwride
631 the defaults discussed just above.
633 - Cache Configuration:
634 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
635 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
636 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
638 - Cache Configuration for ARM:
639 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
641 CONFIG_SYS_PL310_BASE - Physical base address of PL310
642 controller register space
647 Define this if you want support for Amba PrimeCell PL010 UARTs.
651 Define this if you want support for Amba PrimeCell PL011 UARTs.
655 If you have Amba PrimeCell PL011 UARTs, set this variable to
656 the clock speed of the UARTs.
660 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
661 define this to a list of base addresses for each (supported)
662 port. See e.g. include/configs/versatile.h
664 CONFIG_PL011_SERIAL_RLCR
666 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
667 have separate receive and transmit line control registers. Set
668 this variable to initialize the extra register.
670 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
672 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
673 boot loader that has already initialized the UART. Define this
674 variable to flush the UART at init time.
678 Depending on board, define exactly one serial port
679 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
680 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
681 console by defining CONFIG_8xx_CONS_NONE
683 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
684 port routines must be defined elsewhere
685 (i.e. serial_init(), serial_getc(), ...)
688 Enables console device for a color framebuffer. Needs following
689 defines (cf. smiLynxEM, i8042)
690 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
692 VIDEO_HW_RECTFILL graphic chip supports
695 VIDEO_HW_BITBLT graphic chip supports
696 bit-blit (cf. smiLynxEM)
697 VIDEO_VISIBLE_COLS visible pixel columns
699 VIDEO_VISIBLE_ROWS visible pixel rows
700 VIDEO_PIXEL_SIZE bytes per pixel
701 VIDEO_DATA_FORMAT graphic data format
702 (0-5, cf. cfb_console.c)
703 VIDEO_FB_ADRS framebuffer address
704 VIDEO_KBD_INIT_FCT keyboard int fct
705 (i.e. i8042_kbd_init())
706 VIDEO_TSTC_FCT test char fct
708 VIDEO_GETC_FCT get char fct
710 CONFIG_CONSOLE_CURSOR cursor drawing on/off
711 (requires blink timer
713 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
714 CONFIG_CONSOLE_TIME display time/date info in
716 (requires CONFIG_CMD_DATE)
717 CONFIG_VIDEO_LOGO display Linux logo in
719 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
720 linux_logo.h for logo.
721 Requires CONFIG_VIDEO_LOGO
722 CONFIG_CONSOLE_EXTRA_INFO
723 additional board info beside
726 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
727 a limited number of ANSI escape sequences (cursor control,
728 erase functions and limited graphics rendition control).
730 When CONFIG_CFB_CONSOLE is defined, video console is
731 default i/o. Serial console can be forced with
732 environment 'console=serial'.
734 When CONFIG_SILENT_CONSOLE is defined, all console
735 messages (by U-Boot and Linux!) can be silenced with
736 the "silent" environment variable. See
737 doc/README.silent for more information.
739 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
741 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
745 CONFIG_BAUDRATE - in bps
746 Select one of the baudrates listed in
747 CONFIG_SYS_BAUDRATE_TABLE, see below.
748 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
750 - Console Rx buffer length
751 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
752 the maximum receive buffer length for the SMC.
753 This option is actual only for 82xx and 8xx possible.
754 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
755 must be defined, to setup the maximum idle timeout for
758 - Pre-Console Buffer:
759 Prior to the console being initialised (i.e. serial UART
760 initialised etc) all console output is silently discarded.
761 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
762 buffer any console messages prior to the console being
763 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
764 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
765 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
766 bytes are output before the console is initialised, the
767 earlier bytes are discarded.
769 'Sane' compilers will generate smaller code if
770 CONFIG_PRE_CON_BUF_SZ is a power of 2
772 - Safe printf() functions
773 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
774 the printf() functions. These are defined in
775 include/vsprintf.h and include snprintf(), vsnprintf() and
776 so on. Code size increase is approximately 300-500 bytes.
777 If this option is not given then these functions will
778 silently discard their buffer size argument - this means
779 you are not getting any overflow checking in this case.
781 - Boot Delay: CONFIG_BOOTDELAY - in seconds
782 Delay before automatically booting the default image;
783 set to -1 to disable autoboot.
784 set to -2 to autoboot with no delay and not check for abort
785 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
787 See doc/README.autoboot for these options that
788 work with CONFIG_BOOTDELAY. None are required.
789 CONFIG_BOOT_RETRY_TIME
790 CONFIG_BOOT_RETRY_MIN
791 CONFIG_AUTOBOOT_KEYED
792 CONFIG_AUTOBOOT_PROMPT
793 CONFIG_AUTOBOOT_DELAY_STR
794 CONFIG_AUTOBOOT_STOP_STR
795 CONFIG_AUTOBOOT_DELAY_STR2
796 CONFIG_AUTOBOOT_STOP_STR2
797 CONFIG_ZERO_BOOTDELAY_CHECK
798 CONFIG_RESET_TO_RETRY
802 Only needed when CONFIG_BOOTDELAY is enabled;
803 define a command string that is automatically executed
804 when no character is read on the console interface
805 within "Boot Delay" after reset.
808 This can be used to pass arguments to the bootm
809 command. The value of CONFIG_BOOTARGS goes into the
810 environment value "bootargs".
812 CONFIG_RAMBOOT and CONFIG_NFSBOOT
813 The value of these goes into the environment as
814 "ramboot" and "nfsboot" respectively, and can be used
815 as a convenience, when switching between booting from
821 When this option is #defined, the existence of the
822 environment variable "preboot" will be checked
823 immediately before starting the CONFIG_BOOTDELAY
824 countdown and/or running the auto-boot command resp.
825 entering interactive mode.
827 This feature is especially useful when "preboot" is
828 automatically generated or modified. For an example
829 see the LWMON board specific code: here "preboot" is
830 modified when the user holds down a certain
831 combination of keys on the (special) keyboard when
834 - Serial Download Echo Mode:
836 If defined to 1, all characters received during a
837 serial download (using the "loads" command) are
838 echoed back. This might be needed by some terminal
839 emulations (like "cu"), but may as well just take
840 time on others. This setting #define's the initial
841 value of the "loads_echo" environment variable.
843 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
845 Select one of the baudrates listed in
846 CONFIG_SYS_BAUDRATE_TABLE, see below.
849 Monitor commands can be included or excluded
850 from the build by using the #include files
851 <config_cmd_all.h> and #undef'ing unwanted
852 commands, or using <config_cmd_default.h>
853 and augmenting with additional #define's
856 The default command configuration includes all commands
857 except those marked below with a "*".
859 CONFIG_CMD_ASKENV * ask for env variable
860 CONFIG_CMD_BDI bdinfo
861 CONFIG_CMD_BEDBUG * Include BedBug Debugger
862 CONFIG_CMD_BMP * BMP support
863 CONFIG_CMD_BSP * Board specific commands
864 CONFIG_CMD_BOOTD bootd
865 CONFIG_CMD_CACHE * icache, dcache
866 CONFIG_CMD_CONSOLE coninfo
867 CONFIG_CMD_CRC32 * crc32
868 CONFIG_CMD_DATE * support for RTC, date/time...
869 CONFIG_CMD_DHCP * DHCP support
870 CONFIG_CMD_DIAG * Diagnostics
871 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
872 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
873 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
874 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
875 CONFIG_CMD_DTT * Digital Therm and Thermostat
876 CONFIG_CMD_ECHO echo arguments
877 CONFIG_CMD_EDITENV edit env variable
878 CONFIG_CMD_EEPROM * EEPROM read/write support
879 CONFIG_CMD_ELF * bootelf, bootvx
880 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
881 CONFIG_CMD_ENV_FLAGS * display details about env flags
882 CONFIG_CMD_ENV_EXISTS * check existence of env variable
883 CONFIG_CMD_EXPORTENV * export the environment
884 CONFIG_CMD_EXT2 * ext2 command support
885 CONFIG_CMD_EXT4 * ext4 command support
886 CONFIG_CMD_SAVEENV saveenv
887 CONFIG_CMD_FDC * Floppy Disk Support
888 CONFIG_CMD_FAT * FAT command support
889 CONFIG_CMD_FDOS * Dos diskette Support
890 CONFIG_CMD_FLASH flinfo, erase, protect
891 CONFIG_CMD_FPGA FPGA device initialization support
892 CONFIG_CMD_FUSE * Device fuse support
893 CONFIG_CMD_GETTIME * Get time since boot
894 CONFIG_CMD_GO * the 'go' command (exec code)
895 CONFIG_CMD_GREPENV * search environment
896 CONFIG_CMD_HASH * calculate hash / digest
897 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
898 CONFIG_CMD_I2C * I2C serial bus support
899 CONFIG_CMD_IDE * IDE harddisk support
900 CONFIG_CMD_IMI iminfo
901 CONFIG_CMD_IMLS List all images found in NOR flash
902 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
903 CONFIG_CMD_IMMAP * IMMR dump support
904 CONFIG_CMD_IMPORTENV * import an environment
905 CONFIG_CMD_INI * import data from an ini file into the env
906 CONFIG_CMD_IRQ * irqinfo
907 CONFIG_CMD_ITEST Integer/string test of 2 values
908 CONFIG_CMD_JFFS2 * JFFS2 Support
909 CONFIG_CMD_KGDB * kgdb
910 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
911 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
913 CONFIG_CMD_LOADB loadb
914 CONFIG_CMD_LOADS loads
915 CONFIG_CMD_MD5SUM * print md5 message digest
916 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
917 CONFIG_CMD_MEMINFO * Display detailed memory information
918 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
920 CONFIG_CMD_MEMTEST * mtest
921 CONFIG_CMD_MISC Misc functions like sleep etc
922 CONFIG_CMD_MMC * MMC memory mapped support
923 CONFIG_CMD_MII * MII utility commands
924 CONFIG_CMD_MTDPARTS * MTD partition support
925 CONFIG_CMD_NAND * NAND support
926 CONFIG_CMD_NET bootp, tftpboot, rarpboot
927 CONFIG_CMD_NFS NFS support
928 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
929 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
930 CONFIG_CMD_PCI * pciinfo
931 CONFIG_CMD_PCMCIA * PCMCIA support
932 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
934 CONFIG_CMD_PORTIO * Port I/O
935 CONFIG_CMD_READ * Read raw data from partition
936 CONFIG_CMD_REGINFO * Register dump
937 CONFIG_CMD_RUN run command in env variable
938 CONFIG_CMD_SANDBOX * sb command to access sandbox features
939 CONFIG_CMD_SAVES * save S record dump
940 CONFIG_CMD_SCSI * SCSI Support
941 CONFIG_CMD_SDRAM * print SDRAM configuration information
942 (requires CONFIG_CMD_I2C)
943 CONFIG_CMD_SETGETDCR Support for DCR Register access
945 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
946 CONFIG_CMD_SHA1SUM * print sha1 memory digest
947 (requires CONFIG_CMD_MEMORY)
948 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
949 CONFIG_CMD_SOURCE "source" command Support
950 CONFIG_CMD_SPI * SPI serial bus support
951 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
952 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
953 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
954 CONFIG_CMD_TIMER * access to the system tick timer
955 CONFIG_CMD_USB * USB support
956 CONFIG_CMD_CDP * Cisco Discover Protocol support
957 CONFIG_CMD_MFSL * Microblaze FSL support
958 CONFIG_CMD_XIMG Load part of Multi Image
961 EXAMPLE: If you want all functions except of network
962 support you can write:
964 #include "config_cmd_all.h"
965 #undef CONFIG_CMD_NET
968 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
970 Note: Don't enable the "icache" and "dcache" commands
971 (configuration option CONFIG_CMD_CACHE) unless you know
972 what you (and your U-Boot users) are doing. Data
973 cache cannot be enabled on systems like the 8xx or
974 8260 (where accesses to the IMMR region must be
975 uncached), and it cannot be disabled on all other
976 systems where we (mis-) use the data cache to hold an
977 initial stack and some data.
980 XXX - this list needs to get updated!
982 - Regular expression support:
984 If this variable is defined, U-Boot is linked against
985 the SLRE (Super Light Regular Expression) library,
986 which adds regex support to some commands, as for
987 example "env grep" and "setexpr".
991 If this variable is defined, U-Boot will use a device tree
992 to configure its devices, instead of relying on statically
993 compiled #defines in the board file. This option is
994 experimental and only available on a few boards. The device
995 tree is available in the global data as gd->fdt_blob.
997 U-Boot needs to get its device tree from somewhere. This can
998 be done using one of the two options below:
1001 If this variable is defined, U-Boot will embed a device tree
1002 binary in its image. This device tree file should be in the
1003 board directory and called <soc>-<board>.dts. The binary file
1004 is then picked up in board_init_f() and made available through
1005 the global data structure as gd->blob.
1008 If this variable is defined, U-Boot will build a device tree
1009 binary. It will be called u-boot.dtb. Architecture-specific
1010 code will locate it at run-time. Generally this works by:
1012 cat u-boot.bin u-boot.dtb >image.bin
1014 and in fact, U-Boot does this for you, creating a file called
1015 u-boot-dtb.bin which is useful in the common case. You can
1016 still use the individual files if you need something more
1021 If this variable is defined, it enables watchdog
1022 support for the SoC. There must be support in the SoC
1023 specific code for a watchdog. For the 8xx and 8260
1024 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1025 register. When supported for a specific SoC is
1026 available, then no further board specific code should
1027 be needed to use it.
1030 When using a watchdog circuitry external to the used
1031 SoC, then define this variable and provide board
1032 specific code for the "hw_watchdog_reset" function.
1035 CONFIG_VERSION_VARIABLE
1036 If this variable is defined, an environment variable
1037 named "ver" is created by U-Boot showing the U-Boot
1038 version as printed by the "version" command.
1039 Any change to this variable will be reverted at the
1044 When CONFIG_CMD_DATE is selected, the type of the RTC
1045 has to be selected, too. Define exactly one of the
1048 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1049 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1050 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1051 CONFIG_RTC_MC146818 - use MC146818 RTC
1052 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1053 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1054 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1055 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1056 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1057 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1058 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1059 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1062 Note that if the RTC uses I2C, then the I2C interface
1063 must also be configured. See I2C Support, below.
1066 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1068 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1069 chip-ngpio pairs that tell the PCA953X driver the number of
1070 pins supported by a particular chip.
1072 Note that if the GPIO device uses I2C, then the I2C interface
1073 must also be configured. See I2C Support, below.
1075 - Timestamp Support:
1077 When CONFIG_TIMESTAMP is selected, the timestamp
1078 (date and time) of an image is printed by image
1079 commands like bootm or iminfo. This option is
1080 automatically enabled when you select CONFIG_CMD_DATE .
1082 - Partition Labels (disklabels) Supported:
1083 Zero or more of the following:
1084 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1085 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1086 Intel architecture, USB sticks, etc.
1087 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1088 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1089 bootloader. Note 2TB partition limit; see
1091 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1093 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1094 CONFIG_CMD_SCSI) you must configure support for at
1095 least one non-MTD partition type as well.
1098 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1099 board configurations files but used nowhere!
1101 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1102 be performed by calling the function
1103 ide_set_reset(int reset)
1104 which has to be defined in a board specific file
1109 Set this to enable ATAPI support.
1114 Set this to enable support for disks larger than 137GB
1115 Also look at CONFIG_SYS_64BIT_LBA.
1116 Whithout these , LBA48 support uses 32bit variables and will 'only'
1117 support disks up to 2.1TB.
1119 CONFIG_SYS_64BIT_LBA:
1120 When enabled, makes the IDE subsystem use 64bit sector addresses.
1124 At the moment only there is only support for the
1125 SYM53C8XX SCSI controller; define
1126 CONFIG_SCSI_SYM53C8XX to enable it.
1128 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1129 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1130 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1131 maximum numbers of LUNs, SCSI ID's and target
1133 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1135 The environment variable 'scsidevs' is set to the number of
1136 SCSI devices found during the last scan.
1138 - NETWORK Support (PCI):
1140 Support for Intel 8254x/8257x gigabit chips.
1143 Utility code for direct access to the SPI bus on Intel 8257x.
1144 This does not do anything useful unless you set at least one
1145 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1147 CONFIG_E1000_SPI_GENERIC
1148 Allow generic access to the SPI bus on the Intel 8257x, for
1149 example with the "sspi" command.
1152 Management command for E1000 devices. When used on devices
1153 with SPI support you can reprogram the EEPROM from U-Boot.
1155 CONFIG_E1000_FALLBACK_MAC
1156 default MAC for empty EEPROM after production.
1159 Support for Intel 82557/82559/82559ER chips.
1160 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1161 write routine for first time initialisation.
1164 Support for Digital 2114x chips.
1165 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1166 modem chip initialisation (KS8761/QS6611).
1169 Support for National dp83815 chips.
1172 Support for National dp8382[01] gigabit chips.
1174 - NETWORK Support (other):
1176 CONFIG_DRIVER_AT91EMAC
1177 Support for AT91RM9200 EMAC.
1180 Define this to use reduced MII inteface
1182 CONFIG_DRIVER_AT91EMAC_QUIET
1183 If this defined, the driver is quiet.
1184 The driver doen't show link status messages.
1186 CONFIG_CALXEDA_XGMAC
1187 Support for the Calxeda XGMAC device
1190 Support for SMSC's LAN91C96 chips.
1192 CONFIG_LAN91C96_BASE
1193 Define this to hold the physical address
1194 of the LAN91C96's I/O space
1196 CONFIG_LAN91C96_USE_32_BIT
1197 Define this to enable 32 bit addressing
1200 Support for SMSC's LAN91C111 chip
1202 CONFIG_SMC91111_BASE
1203 Define this to hold the physical address
1204 of the device (I/O space)
1206 CONFIG_SMC_USE_32_BIT
1207 Define this if data bus is 32 bits
1209 CONFIG_SMC_USE_IOFUNCS
1210 Define this to use i/o functions instead of macros
1211 (some hardware wont work with macros)
1213 CONFIG_DRIVER_TI_EMAC
1214 Support for davinci emac
1216 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1217 Define this if you have more then 3 PHYs.
1220 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1222 CONFIG_FTGMAC100_EGIGA
1223 Define this to use GE link update with gigabit PHY.
1224 Define this if FTGMAC100 is connected to gigabit PHY.
1225 If your system has 10/100 PHY only, it might not occur
1226 wrong behavior. Because PHY usually return timeout or
1227 useless data when polling gigabit status and gigabit
1228 control registers. This behavior won't affect the
1229 correctnessof 10/100 link speed update.
1232 Support for SMSC's LAN911x and LAN921x chips
1235 Define this to hold the physical address
1236 of the device (I/O space)
1238 CONFIG_SMC911X_32_BIT
1239 Define this if data bus is 32 bits
1241 CONFIG_SMC911X_16_BIT
1242 Define this if data bus is 16 bits. If your processor
1243 automatically converts one 32 bit word to two 16 bit
1244 words you may also try CONFIG_SMC911X_32_BIT.
1247 Support for Renesas on-chip Ethernet controller
1249 CONFIG_SH_ETHER_USE_PORT
1250 Define the number of ports to be used
1252 CONFIG_SH_ETHER_PHY_ADDR
1253 Define the ETH PHY's address
1255 CONFIG_SH_ETHER_CACHE_WRITEBACK
1256 If this option is set, the driver enables cache flush.
1260 Support TPM devices.
1263 Support for i2c bus TPM devices. Only one device
1264 per system is supported at this time.
1266 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1267 Define the the i2c bus number for the TPM device
1269 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1270 Define the TPM's address on the i2c bus
1272 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1273 Define the burst count bytes upper limit
1275 CONFIG_TPM_ATMEL_TWI
1276 Support for Atmel TWI TPM device. Requires I2C support.
1279 Support for generic parallel port TPM devices. Only one device
1280 per system is supported at this time.
1282 CONFIG_TPM_TIS_BASE_ADDRESS
1283 Base address where the generic TPM device is mapped
1284 to. Contemporary x86 systems usually map it at
1288 Add tpm monitor functions.
1289 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1290 provides monitor access to authorized functions.
1293 Define this to enable the TPM support library which provides
1294 functional interfaces to some TPM commands.
1295 Requires support for a TPM device.
1297 CONFIG_TPM_AUTH_SESSIONS
1298 Define this to enable authorized functions in the TPM library.
1299 Requires CONFIG_TPM and CONFIG_SHA1.
1302 At the moment only the UHCI host controller is
1303 supported (PIP405, MIP405, MPC5200); define
1304 CONFIG_USB_UHCI to enable it.
1305 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1306 and define CONFIG_USB_STORAGE to enable the USB
1309 Supported are USB Keyboards and USB Floppy drives
1311 MPC5200 USB requires additional defines:
1313 for 528 MHz Clock: 0x0001bbbb
1317 for differential drivers: 0x00001000
1318 for single ended drivers: 0x00005000
1319 for differential drivers on PSC3: 0x00000100
1320 for single ended drivers on PSC3: 0x00004100
1321 CONFIG_SYS_USB_EVENT_POLL
1322 May be defined to allow interrupt polling
1323 instead of using asynchronous interrupts
1325 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1326 txfilltuning field in the EHCI controller on reset.
1328 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1329 interval for usb hub power-on delay.(minimum 100msec)
1332 Define the below if you wish to use the USB console.
1333 Once firmware is rebuilt from a serial console issue the
1334 command "setenv stdin usbtty; setenv stdout usbtty" and
1335 attach your USB cable. The Unix command "dmesg" should print
1336 it has found a new device. The environment variable usbtty
1337 can be set to gserial or cdc_acm to enable your device to
1338 appear to a USB host as a Linux gserial device or a
1339 Common Device Class Abstract Control Model serial device.
1340 If you select usbtty = gserial you should be able to enumerate
1342 # modprobe usbserial vendor=0xVendorID product=0xProductID
1343 else if using cdc_acm, simply setting the environment
1344 variable usbtty to be cdc_acm should suffice. The following
1345 might be defined in YourBoardName.h
1348 Define this to build a UDC device
1351 Define this to have a tty type of device available to
1352 talk to the UDC device
1355 Define this to enable the high speed support for usb
1356 device and usbtty. If this feature is enabled, a routine
1357 int is_usbd_high_speed(void)
1358 also needs to be defined by the driver to dynamically poll
1359 whether the enumeration has succeded at high speed or full
1362 CONFIG_SYS_CONSOLE_IS_IN_ENV
1363 Define this if you want stdin, stdout &/or stderr to
1367 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1368 Derive USB clock from external clock "blah"
1369 - CONFIG_SYS_USB_EXTC_CLK 0x02
1371 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1372 Derive USB clock from brgclk
1373 - CONFIG_SYS_USB_BRG_CLK 0x04
1375 If you have a USB-IF assigned VendorID then you may wish to
1376 define your own vendor specific values either in BoardName.h
1377 or directly in usbd_vendor_info.h. If you don't define
1378 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1379 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1380 should pretend to be a Linux device to it's target host.
1382 CONFIG_USBD_MANUFACTURER
1383 Define this string as the name of your company for
1384 - CONFIG_USBD_MANUFACTURER "my company"
1386 CONFIG_USBD_PRODUCT_NAME
1387 Define this string as the name of your product
1388 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1390 CONFIG_USBD_VENDORID
1391 Define this as your assigned Vendor ID from the USB
1392 Implementors Forum. This *must* be a genuine Vendor ID
1393 to avoid polluting the USB namespace.
1394 - CONFIG_USBD_VENDORID 0xFFFF
1396 CONFIG_USBD_PRODUCTID
1397 Define this as the unique Product ID
1399 - CONFIG_USBD_PRODUCTID 0xFFFF
1401 Some USB device drivers may need to check USB cable attachment.
1402 In this case you can enable following config in BoardName.h:
1403 CONFIG_USB_CABLE_CHECK
1404 This enables function definition:
1405 - usb_cable_connected() in include/usb.h
1406 Implementation of this function is board-specific.
1408 - ULPI Layer Support:
1409 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1410 the generic ULPI layer. The generic layer accesses the ULPI PHY
1411 via the platform viewport, so you need both the genric layer and
1412 the viewport enabled. Currently only Chipidea/ARC based
1413 viewport is supported.
1414 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1415 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1416 If your ULPI phy needs a different reference clock than the
1417 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1418 the appropriate value in Hz.
1421 The MMC controller on the Intel PXA is supported. To
1422 enable this define CONFIG_MMC. The MMC can be
1423 accessed from the boot prompt by mapping the device
1424 to physical memory similar to flash. Command line is
1425 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1426 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1429 Support for Renesas on-chip MMCIF controller
1431 CONFIG_SH_MMCIF_ADDR
1432 Define the base address of MMCIF registers
1435 Define the clock frequency for MMCIF
1437 - USB Device Firmware Update (DFU) class support:
1439 This enables the USB portion of the DFU USB class
1442 This enables the command "dfu" which is used to have
1443 U-Boot create a DFU class device via USB. This command
1444 requires that the "dfu_alt_info" environment variable be
1445 set and define the alt settings to expose to the host.
1448 This enables support for exposing (e)MMC devices via DFU.
1451 This enables support for exposing NAND devices via DFU.
1454 This enables support for exposing RAM via DFU.
1455 Note: DFU spec refer to non-volatile memory usage, but
1456 allow usages beyond the scope of spec - here RAM usage,
1457 one that would help mostly the developer.
1459 CONFIG_SYS_DFU_DATA_BUF_SIZE
1460 Dfu transfer uses a buffer before writing data to the
1461 raw storage device. Make the size (in bytes) of this buffer
1462 configurable. The size of this buffer is also configurable
1463 through the "dfu_bufsiz" environment variable.
1465 CONFIG_SYS_DFU_MAX_FILE_SIZE
1466 When updating files rather than the raw storage device,
1467 we use a static buffer to copy the file into and then write
1468 the buffer once we've been given the whole file. Define
1469 this to the maximum filesize (in bytes) for the buffer.
1470 Default is 4 MiB if undefined.
1472 - Journaling Flash filesystem support:
1473 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1474 CONFIG_JFFS2_NAND_DEV
1475 Define these for a default partition on a NAND device
1477 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1478 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1479 Define these for a default partition on a NOR device
1481 CONFIG_SYS_JFFS_CUSTOM_PART
1482 Define this to create an own partition. You have to provide a
1483 function struct part_info* jffs2_part_info(int part_num)
1485 If you define only one JFFS2 partition you may also want to
1486 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1487 to disable the command chpart. This is the default when you
1488 have not defined a custom partition
1490 - FAT(File Allocation Table) filesystem write function support:
1493 Define this to enable support for saving memory data as a
1494 file in FAT formatted partition.
1496 This will also enable the command "fatwrite" enabling the
1497 user to write files to FAT.
1499 CBFS (Coreboot Filesystem) support
1502 Define this to enable support for reading from a Coreboot
1503 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1509 Define this to enable standard (PC-Style) keyboard
1513 Standard PC keyboard driver with US (is default) and
1514 GERMAN key layout (switch via environment 'keymap=de') support.
1515 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1516 for cfb_console. Supports cursor blinking.
1519 Enables a Chrome OS keyboard using the CROS_EC interface.
1520 This uses CROS_EC to communicate with a second microcontroller
1521 which provides key scans on request.
1526 Define this to enable video support (for output to
1529 CONFIG_VIDEO_CT69000
1531 Enable Chips & Technologies 69000 Video chip
1533 CONFIG_VIDEO_SMI_LYNXEM
1534 Enable Silicon Motion SMI 712/710/810 Video chip. The
1535 video output is selected via environment 'videoout'
1536 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1539 For the CT69000 and SMI_LYNXEM drivers, videomode is
1540 selected via environment 'videomode'. Two different ways
1542 - "videomode=num" 'num' is a standard LiLo mode numbers.
1543 Following standard modes are supported (* is default):
1545 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1546 -------------+---------------------------------------------
1547 8 bits | 0x301* 0x303 0x305 0x161 0x307
1548 15 bits | 0x310 0x313 0x316 0x162 0x319
1549 16 bits | 0x311 0x314 0x317 0x163 0x31A
1550 24 bits | 0x312 0x315 0x318 ? 0x31B
1551 -------------+---------------------------------------------
1552 (i.e. setenv videomode 317; saveenv; reset;)
1554 - "videomode=bootargs" all the video parameters are parsed
1555 from the bootargs. (See drivers/video/videomodes.c)
1558 CONFIG_VIDEO_SED13806
1559 Enable Epson SED13806 driver. This driver supports 8bpp
1560 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1561 or CONFIG_VIDEO_SED13806_16BPP
1564 Enable the Freescale DIU video driver. Reference boards for
1565 SOCs that have a DIU should define this macro to enable DIU
1566 support, and should also define these other macros:
1572 CONFIG_VIDEO_SW_CURSOR
1573 CONFIG_VGA_AS_SINGLE_DEVICE
1575 CONFIG_VIDEO_BMP_LOGO
1577 The DIU driver will look for the 'video-mode' environment
1578 variable, and if defined, enable the DIU as a console during
1579 boot. See the documentation file README.video for a
1580 description of this variable.
1584 Enable the VGA video / BIOS for x86. The alternative if you
1585 are using coreboot is to use the coreboot frame buffer
1592 Define this to enable a custom keyboard support.
1593 This simply calls drv_keyboard_init() which must be
1594 defined in your board-specific files.
1595 The only board using this so far is RBC823.
1597 - LCD Support: CONFIG_LCD
1599 Define this to enable LCD support (for output to LCD
1600 display); also select one of the supported displays
1601 by defining one of these:
1605 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1607 CONFIG_NEC_NL6448AC33:
1609 NEC NL6448AC33-18. Active, color, single scan.
1611 CONFIG_NEC_NL6448BC20
1613 NEC NL6448BC20-08. 6.5", 640x480.
1614 Active, color, single scan.
1616 CONFIG_NEC_NL6448BC33_54
1618 NEC NL6448BC33-54. 10.4", 640x480.
1619 Active, color, single scan.
1623 Sharp 320x240. Active, color, single scan.
1624 It isn't 16x9, and I am not sure what it is.
1626 CONFIG_SHARP_LQ64D341
1628 Sharp LQ64D341 display, 640x480.
1629 Active, color, single scan.
1633 HLD1045 display, 640x480.
1634 Active, color, single scan.
1638 Optrex CBL50840-2 NF-FW 99 22 M5
1640 Hitachi LMG6912RPFC-00T
1644 320x240. Black & white.
1646 Normally display is black on white background; define
1647 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1649 CONFIG_LCD_ALIGNMENT
1651 Normally the LCD is page-aligned (tyically 4KB). If this is
1652 defined then the LCD will be aligned to this value instead.
1653 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1654 here, since it is cheaper to change data cache settings on
1655 a per-section basis.
1657 CONFIG_CONSOLE_SCROLL_LINES
1659 When the console need to be scrolled, this is the number of
1660 lines to scroll by. It defaults to 1. Increasing this makes
1661 the console jump but can help speed up operation when scrolling
1666 Support drawing of RLE8-compressed bitmaps on the LCD.
1670 Enables an 'i2c edid' command which can read EDID
1671 information over I2C from an attached LCD display.
1673 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1675 If this option is set, the environment is checked for
1676 a variable "splashimage". If found, the usual display
1677 of logo, copyright and system information on the LCD
1678 is suppressed and the BMP image at the address
1679 specified in "splashimage" is loaded instead. The
1680 console is redirected to the "nulldev", too. This
1681 allows for a "silent" boot where a splash screen is
1682 loaded very quickly after power-on.
1684 CONFIG_SPLASHIMAGE_GUARD
1686 If this option is set, then U-Boot will prevent the environment
1687 variable "splashimage" from being set to a problematic address
1688 (see README.displaying-bmps and README.arm-unaligned-accesses).
1689 This option is useful for targets where, due to alignment
1690 restrictions, an improperly aligned BMP image will cause a data
1691 abort. If you think you will not have problems with unaligned
1692 accesses (for example because your toolchain prevents them)
1693 there is no need to set this option.
1695 CONFIG_SPLASH_SCREEN_ALIGN
1697 If this option is set the splash image can be freely positioned
1698 on the screen. Environment variable "splashpos" specifies the
1699 position as "x,y". If a positive number is given it is used as
1700 number of pixel from left/top. If a negative number is given it
1701 is used as number of pixel from right/bottom. You can also
1702 specify 'm' for centering the image.
1705 setenv splashpos m,m
1706 => image at center of screen
1708 setenv splashpos 30,20
1709 => image at x = 30 and y = 20
1711 setenv splashpos -10,m
1712 => vertically centered image
1713 at x = dspWidth - bmpWidth - 9
1715 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1717 If this option is set, additionally to standard BMP
1718 images, gzipped BMP images can be displayed via the
1719 splashscreen support or the bmp command.
1721 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1723 If this option is set, 8-bit RLE compressed BMP images
1724 can be displayed via the splashscreen support or the
1727 - Do compresssing for memory range:
1730 If this option is set, it would use zlib deflate method
1731 to compress the specified memory at its best effort.
1733 - Compression support:
1736 Enabled by default to support gzip compressed images.
1740 If this option is set, support for bzip2 compressed
1741 images is included. If not, only uncompressed and gzip
1742 compressed images are supported.
1744 NOTE: the bzip2 algorithm requires a lot of RAM, so
1745 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1750 If this option is set, support for lzma compressed
1753 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1754 requires an amount of dynamic memory that is given by the
1757 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1759 Where lc and lp stand for, respectively, Literal context bits
1760 and Literal pos bits.
1762 This value is upper-bounded by 14MB in the worst case. Anyway,
1763 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1764 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1765 a very small buffer.
1767 Use the lzmainfo tool to determinate the lc and lp values and
1768 then calculate the amount of needed dynamic memory (ensuring
1769 the appropriate CONFIG_SYS_MALLOC_LEN value).
1773 If this option is set, support for LZO compressed images
1779 The address of PHY on MII bus.
1781 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1783 The clock frequency of the MII bus
1787 If this option is set, support for speed/duplex
1788 detection of gigabit PHY is included.
1790 CONFIG_PHY_RESET_DELAY
1792 Some PHY like Intel LXT971A need extra delay after
1793 reset before any MII register access is possible.
1794 For such PHY, set this option to the usec delay
1795 required. (minimum 300usec for LXT971A)
1797 CONFIG_PHY_CMD_DELAY (ppc4xx)
1799 Some PHY like Intel LXT971A need extra delay after
1800 command issued before MII status register can be read
1810 Define a default value for Ethernet address to use
1811 for the respective Ethernet interface, in case this
1812 is not determined automatically.
1817 Define a default value for the IP address to use for
1818 the default Ethernet interface, in case this is not
1819 determined through e.g. bootp.
1820 (Environment variable "ipaddr")
1822 - Server IP address:
1825 Defines a default value for the IP address of a TFTP
1826 server to contact when using the "tftboot" command.
1827 (Environment variable "serverip")
1829 CONFIG_KEEP_SERVERADDR
1831 Keeps the server's MAC address, in the env 'serveraddr'
1832 for passing to bootargs (like Linux's netconsole option)
1834 - Gateway IP address:
1837 Defines a default value for the IP address of the
1838 default router where packets to other networks are
1840 (Environment variable "gatewayip")
1845 Defines a default value for the subnet mask (or
1846 routing prefix) which is used to determine if an IP
1847 address belongs to the local subnet or needs to be
1848 forwarded through a router.
1849 (Environment variable "netmask")
1851 - Multicast TFTP Mode:
1854 Defines whether you want to support multicast TFTP as per
1855 rfc-2090; for example to work with atftp. Lets lots of targets
1856 tftp down the same boot image concurrently. Note: the Ethernet
1857 driver in use must provide a function: mcast() to join/leave a
1860 - BOOTP Recovery Mode:
1861 CONFIG_BOOTP_RANDOM_DELAY
1863 If you have many targets in a network that try to
1864 boot using BOOTP, you may want to avoid that all
1865 systems send out BOOTP requests at precisely the same
1866 moment (which would happen for instance at recovery
1867 from a power failure, when all systems will try to
1868 boot, thus flooding the BOOTP server. Defining
1869 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1870 inserted before sending out BOOTP requests. The
1871 following delays are inserted then:
1873 1st BOOTP request: delay 0 ... 1 sec
1874 2nd BOOTP request: delay 0 ... 2 sec
1875 3rd BOOTP request: delay 0 ... 4 sec
1877 BOOTP requests: delay 0 ... 8 sec
1879 - DHCP Advanced Options:
1880 You can fine tune the DHCP functionality by defining
1881 CONFIG_BOOTP_* symbols:
1883 CONFIG_BOOTP_SUBNETMASK
1884 CONFIG_BOOTP_GATEWAY
1885 CONFIG_BOOTP_HOSTNAME
1886 CONFIG_BOOTP_NISDOMAIN
1887 CONFIG_BOOTP_BOOTPATH
1888 CONFIG_BOOTP_BOOTFILESIZE
1891 CONFIG_BOOTP_SEND_HOSTNAME
1892 CONFIG_BOOTP_NTPSERVER
1893 CONFIG_BOOTP_TIMEOFFSET
1894 CONFIG_BOOTP_VENDOREX
1895 CONFIG_BOOTP_MAY_FAIL
1897 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1898 environment variable, not the BOOTP server.
1900 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1901 after the configured retry count, the call will fail
1902 instead of starting over. This can be used to fail over
1903 to Link-local IP address configuration if the DHCP server
1906 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1907 serverip from a DHCP server, it is possible that more
1908 than one DNS serverip is offered to the client.
1909 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1910 serverip will be stored in the additional environment
1911 variable "dnsip2". The first DNS serverip is always
1912 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1915 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1916 to do a dynamic update of a DNS server. To do this, they
1917 need the hostname of the DHCP requester.
1918 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1919 of the "hostname" environment variable is passed as
1920 option 12 to the DHCP server.
1922 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1924 A 32bit value in microseconds for a delay between
1925 receiving a "DHCP Offer" and sending the "DHCP Request".
1926 This fixes a problem with certain DHCP servers that don't
1927 respond 100% of the time to a "DHCP request". E.g. On an
1928 AT91RM9200 processor running at 180MHz, this delay needed
1929 to be *at least* 15,000 usec before a Windows Server 2003
1930 DHCP server would reply 100% of the time. I recommend at
1931 least 50,000 usec to be safe. The alternative is to hope
1932 that one of the retries will be successful but note that
1933 the DHCP timeout and retry process takes a longer than
1936 - Link-local IP address negotiation:
1937 Negotiate with other link-local clients on the local network
1938 for an address that doesn't require explicit configuration.
1939 This is especially useful if a DHCP server cannot be guaranteed
1940 to exist in all environments that the device must operate.
1942 See doc/README.link-local for more information.
1945 CONFIG_CDP_DEVICE_ID
1947 The device id used in CDP trigger frames.
1949 CONFIG_CDP_DEVICE_ID_PREFIX
1951 A two character string which is prefixed to the MAC address
1956 A printf format string which contains the ascii name of
1957 the port. Normally is set to "eth%d" which sets
1958 eth0 for the first Ethernet, eth1 for the second etc.
1960 CONFIG_CDP_CAPABILITIES
1962 A 32bit integer which indicates the device capabilities;
1963 0x00000010 for a normal host which does not forwards.
1967 An ascii string containing the version of the software.
1971 An ascii string containing the name of the platform.
1975 A 32bit integer sent on the trigger.
1977 CONFIG_CDP_POWER_CONSUMPTION
1979 A 16bit integer containing the power consumption of the
1980 device in .1 of milliwatts.
1982 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1984 A byte containing the id of the VLAN.
1986 - Status LED: CONFIG_STATUS_LED
1988 Several configurations allow to display the current
1989 status using a LED. For instance, the LED will blink
1990 fast while running U-Boot code, stop blinking as
1991 soon as a reply to a BOOTP request was received, and
1992 start blinking slow once the Linux kernel is running
1993 (supported by a status LED driver in the Linux
1994 kernel). Defining CONFIG_STATUS_LED enables this
1997 - CAN Support: CONFIG_CAN_DRIVER
1999 Defining CONFIG_CAN_DRIVER enables CAN driver support
2000 on those systems that support this (optional)
2001 feature, like the TQM8xxL modules.
2003 - I2C Support: CONFIG_SYS_I2C
2005 This enable the NEW i2c subsystem, and will allow you to use
2006 i2c commands at the u-boot command line (as long as you set
2007 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2008 based realtime clock chips or other i2c devices. See
2009 common/cmd_i2c.c for a description of the command line
2012 ported i2c driver to the new framework:
2013 - drivers/i2c/soft_i2c.c:
2014 - activate first bus with CONFIG_SYS_I2C_SOFT define
2015 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2016 for defining speed and slave address
2017 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2018 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2019 for defining speed and slave address
2020 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2021 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2022 for defining speed and slave address
2023 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2024 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2025 for defining speed and slave address
2027 - drivers/i2c/fsl_i2c.c:
2028 - activate i2c driver with CONFIG_SYS_I2C_FSL
2029 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2030 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2031 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2033 - If your board supports a second fsl i2c bus, define
2034 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2035 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2036 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2039 - drivers/i2c/tegra_i2c.c:
2040 - activate this driver with CONFIG_SYS_I2C_TEGRA
2041 - This driver adds 4 i2c buses with a fix speed from
2042 100000 and the slave addr 0!
2044 - drivers/i2c/ppc4xx_i2c.c
2045 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2046 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2047 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2049 - drivers/i2c/i2c_mxc.c
2050 - activate this driver with CONFIG_SYS_I2C_MXC
2051 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2052 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2053 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2054 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2055 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2056 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2057 If thoses defines are not set, default value is 100000
2058 for speed, and 0 for slave.
2060 - drivers/i2c/rcar_i2c.c:
2061 - activate this driver with CONFIG_SYS_I2C_RCAR
2062 - This driver adds 4 i2c buses
2064 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2065 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2066 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2067 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2068 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2069 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2070 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2071 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2072 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2074 - drivers/i2c/sh_i2c.c:
2075 - activate this driver with CONFIG_SYS_I2C_SH
2076 - This driver adds from 2 to 5 i2c buses
2078 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2079 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2080 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2081 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2082 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2083 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2084 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2085 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2086 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2087 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2088 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2089 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2090 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2092 - drivers/i2c/omap24xx_i2c.c
2093 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2094 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2095 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2096 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2097 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2098 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2099 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2100 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2101 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2102 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2103 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2105 - drivers/i2c/zynq_i2c.c
2106 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2107 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2108 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2112 CONFIG_SYS_NUM_I2C_BUSES
2113 Hold the number of i2c busses you want to use. If you
2114 don't use/have i2c muxes on your i2c bus, this
2115 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2118 CONFIG_SYS_I2C_DIRECT_BUS
2119 define this, if you don't use i2c muxes on your hardware.
2120 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2123 CONFIG_SYS_I2C_MAX_HOPS
2124 define how many muxes are maximal consecutively connected
2125 on one i2c bus. If you not use i2c muxes, omit this
2128 CONFIG_SYS_I2C_BUSES
2129 hold a list of busses you want to use, only used if
2130 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2131 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2132 CONFIG_SYS_NUM_I2C_BUSES = 9:
2134 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2135 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2136 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2137 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2138 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2139 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2140 {1, {I2C_NULL_HOP}}, \
2141 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2142 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2146 bus 0 on adapter 0 without a mux
2147 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2148 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2149 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2150 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2151 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2152 bus 6 on adapter 1 without a mux
2153 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2154 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2156 If you do not have i2c muxes on your board, omit this define.
2158 - Legacy I2C Support: CONFIG_HARD_I2C
2160 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2161 provides the following compelling advantages:
2163 - more than one i2c adapter is usable
2164 - approved multibus support
2165 - better i2c mux support
2167 ** Please consider updating your I2C driver now. **
2169 These enable legacy I2C serial bus commands. Defining
2170 CONFIG_HARD_I2C will include the appropriate I2C driver
2171 for the selected CPU.
2173 This will allow you to use i2c commands at the u-boot
2174 command line (as long as you set CONFIG_CMD_I2C in
2175 CONFIG_COMMANDS) and communicate with i2c based realtime
2176 clock chips. See common/cmd_i2c.c for a description of the
2177 command line interface.
2179 CONFIG_HARD_I2C selects a hardware I2C controller.
2181 There are several other quantities that must also be
2182 defined when you define CONFIG_HARD_I2C.
2184 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2185 to be the frequency (in Hz) at which you wish your i2c bus
2186 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2187 the CPU's i2c node address).
2189 Now, the u-boot i2c code for the mpc8xx
2190 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2191 and so its address should therefore be cleared to 0 (See,
2192 eg, MPC823e User's Manual p.16-473). So, set
2193 CONFIG_SYS_I2C_SLAVE to 0.
2195 CONFIG_SYS_I2C_INIT_MPC5XXX
2197 When a board is reset during an i2c bus transfer
2198 chips might think that the current transfer is still
2199 in progress. Reset the slave devices by sending start
2200 commands until the slave device responds.
2202 That's all that's required for CONFIG_HARD_I2C.
2204 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2205 then the following macros need to be defined (examples are
2206 from include/configs/lwmon.h):
2210 (Optional). Any commands necessary to enable the I2C
2211 controller or configure ports.
2213 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2217 (Only for MPC8260 CPU). The I/O port to use (the code
2218 assumes both bits are on the same port). Valid values
2219 are 0..3 for ports A..D.
2223 The code necessary to make the I2C data line active
2224 (driven). If the data line is open collector, this
2227 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2231 The code necessary to make the I2C data line tri-stated
2232 (inactive). If the data line is open collector, this
2235 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2239 Code that returns true if the I2C data line is high,
2242 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2246 If <bit> is true, sets the I2C data line high. If it
2247 is false, it clears it (low).
2249 eg: #define I2C_SDA(bit) \
2250 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2251 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2255 If <bit> is true, sets the I2C clock line high. If it
2256 is false, it clears it (low).
2258 eg: #define I2C_SCL(bit) \
2259 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2260 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2264 This delay is invoked four times per clock cycle so this
2265 controls the rate of data transfer. The data rate thus
2266 is 1 / (I2C_DELAY * 4). Often defined to be something
2269 #define I2C_DELAY udelay(2)
2271 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2273 If your arch supports the generic GPIO framework (asm/gpio.h),
2274 then you may alternatively define the two GPIOs that are to be
2275 used as SCL / SDA. Any of the previous I2C_xxx macros will
2276 have GPIO-based defaults assigned to them as appropriate.
2278 You should define these to the GPIO value as given directly to
2279 the generic GPIO functions.
2281 CONFIG_SYS_I2C_INIT_BOARD
2283 When a board is reset during an i2c bus transfer
2284 chips might think that the current transfer is still
2285 in progress. On some boards it is possible to access
2286 the i2c SCLK line directly, either by using the
2287 processor pin as a GPIO or by having a second pin
2288 connected to the bus. If this option is defined a
2289 custom i2c_init_board() routine in boards/xxx/board.c
2290 is run early in the boot sequence.
2292 CONFIG_SYS_I2C_BOARD_LATE_INIT
2294 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2295 defined a custom i2c_board_late_init() routine in
2296 boards/xxx/board.c is run AFTER the operations in i2c_init()
2297 is completed. This callpoint can be used to unreset i2c bus
2298 using CPU i2c controller register accesses for CPUs whose i2c
2299 controller provide such a method. It is called at the end of
2300 i2c_init() to allow i2c_init operations to setup the i2c bus
2301 controller on the CPU (e.g. setting bus speed & slave address).
2303 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2305 This option enables configuration of bi_iic_fast[] flags
2306 in u-boot bd_info structure based on u-boot environment
2307 variable "i2cfast". (see also i2cfast)
2309 CONFIG_I2C_MULTI_BUS
2311 This option allows the use of multiple I2C buses, each of which
2312 must have a controller. At any point in time, only one bus is
2313 active. To switch to a different bus, use the 'i2c dev' command.
2314 Note that bus numbering is zero-based.
2316 CONFIG_SYS_I2C_NOPROBES
2318 This option specifies a list of I2C devices that will be skipped
2319 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2320 is set, specify a list of bus-device pairs. Otherwise, specify
2321 a 1D array of device addresses
2324 #undef CONFIG_I2C_MULTI_BUS
2325 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2327 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2329 #define CONFIG_I2C_MULTI_BUS
2330 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2332 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2334 CONFIG_SYS_SPD_BUS_NUM
2336 If defined, then this indicates the I2C bus number for DDR SPD.
2337 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2339 CONFIG_SYS_RTC_BUS_NUM
2341 If defined, then this indicates the I2C bus number for the RTC.
2342 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2344 CONFIG_SYS_DTT_BUS_NUM
2346 If defined, then this indicates the I2C bus number for the DTT.
2347 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2349 CONFIG_SYS_I2C_DTT_ADDR:
2351 If defined, specifies the I2C address of the DTT device.
2352 If not defined, then U-Boot uses predefined value for
2353 specified DTT device.
2355 CONFIG_SOFT_I2C_READ_REPEATED_START
2357 defining this will force the i2c_read() function in
2358 the soft_i2c driver to perform an I2C repeated start
2359 between writing the address pointer and reading the
2360 data. If this define is omitted the default behaviour
2361 of doing a stop-start sequence will be used. Most I2C
2362 devices can use either method, but some require one or
2365 - SPI Support: CONFIG_SPI
2367 Enables SPI driver (so far only tested with
2368 SPI EEPROM, also an instance works with Crystal A/D and
2369 D/As on the SACSng board)
2373 Enables the driver for SPI controller on SuperH. Currently
2374 only SH7757 is supported.
2378 Enables extended (16-bit) SPI EEPROM addressing.
2379 (symmetrical to CONFIG_I2C_X)
2383 Enables a software (bit-bang) SPI driver rather than
2384 using hardware support. This is a general purpose
2385 driver that only requires three general I/O port pins
2386 (two outputs, one input) to function. If this is
2387 defined, the board configuration must define several
2388 SPI configuration items (port pins to use, etc). For
2389 an example, see include/configs/sacsng.h.
2393 Enables a hardware SPI driver for general-purpose reads
2394 and writes. As with CONFIG_SOFT_SPI, the board configuration
2395 must define a list of chip-select function pointers.
2396 Currently supported on some MPC8xxx processors. For an
2397 example, see include/configs/mpc8349emds.h.
2401 Enables the driver for the SPI controllers on i.MX and MXC
2402 SoCs. Currently i.MX31/35/51 are supported.
2404 - FPGA Support: CONFIG_FPGA
2406 Enables FPGA subsystem.
2408 CONFIG_FPGA_<vendor>
2410 Enables support for specific chip vendors.
2413 CONFIG_FPGA_<family>
2415 Enables support for FPGA family.
2416 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2420 Specify the number of FPGA devices to support.
2422 CONFIG_SYS_FPGA_PROG_FEEDBACK
2424 Enable printing of hash marks during FPGA configuration.
2426 CONFIG_SYS_FPGA_CHECK_BUSY
2428 Enable checks on FPGA configuration interface busy
2429 status by the configuration function. This option
2430 will require a board or device specific function to
2435 If defined, a function that provides delays in the FPGA
2436 configuration driver.
2438 CONFIG_SYS_FPGA_CHECK_CTRLC
2439 Allow Control-C to interrupt FPGA configuration
2441 CONFIG_SYS_FPGA_CHECK_ERROR
2443 Check for configuration errors during FPGA bitfile
2444 loading. For example, abort during Virtex II
2445 configuration if the INIT_B line goes low (which
2446 indicated a CRC error).
2448 CONFIG_SYS_FPGA_WAIT_INIT
2450 Maximum time to wait for the INIT_B line to deassert
2451 after PROB_B has been deasserted during a Virtex II
2452 FPGA configuration sequence. The default time is 500
2455 CONFIG_SYS_FPGA_WAIT_BUSY
2457 Maximum time to wait for BUSY to deassert during
2458 Virtex II FPGA configuration. The default is 5 ms.
2460 CONFIG_SYS_FPGA_WAIT_CONFIG
2462 Time to wait after FPGA configuration. The default is
2465 - Configuration Management:
2468 If defined, this string will be added to the U-Boot
2469 version information (U_BOOT_VERSION)
2471 - Vendor Parameter Protection:
2473 U-Boot considers the values of the environment
2474 variables "serial#" (Board Serial Number) and
2475 "ethaddr" (Ethernet Address) to be parameters that
2476 are set once by the board vendor / manufacturer, and
2477 protects these variables from casual modification by
2478 the user. Once set, these variables are read-only,
2479 and write or delete attempts are rejected. You can
2480 change this behaviour:
2482 If CONFIG_ENV_OVERWRITE is #defined in your config
2483 file, the write protection for vendor parameters is
2484 completely disabled. Anybody can change or delete
2487 Alternatively, if you #define _both_ CONFIG_ETHADDR
2488 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2489 Ethernet address is installed in the environment,
2490 which can be changed exactly ONCE by the user. [The
2491 serial# is unaffected by this, i. e. it remains
2494 The same can be accomplished in a more flexible way
2495 for any variable by configuring the type of access
2496 to allow for those variables in the ".flags" variable
2497 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2502 Define this variable to enable the reservation of
2503 "protected RAM", i. e. RAM which is not overwritten
2504 by U-Boot. Define CONFIG_PRAM to hold the number of
2505 kB you want to reserve for pRAM. You can overwrite
2506 this default value by defining an environment
2507 variable "pram" to the number of kB you want to
2508 reserve. Note that the board info structure will
2509 still show the full amount of RAM. If pRAM is
2510 reserved, a new environment variable "mem" will
2511 automatically be defined to hold the amount of
2512 remaining RAM in a form that can be passed as boot
2513 argument to Linux, for instance like that:
2515 setenv bootargs ... mem=\${mem}
2518 This way you can tell Linux not to use this memory,
2519 either, which results in a memory region that will
2520 not be affected by reboots.
2522 *WARNING* If your board configuration uses automatic
2523 detection of the RAM size, you must make sure that
2524 this memory test is non-destructive. So far, the
2525 following board configurations are known to be
2528 IVMS8, IVML24, SPD8xx, TQM8xxL,
2529 HERMES, IP860, RPXlite, LWMON,
2532 - Access to physical memory region (> 4GB)
2533 Some basic support is provided for operations on memory not
2534 normally accessible to U-Boot - e.g. some architectures
2535 support access to more than 4GB of memory on 32-bit
2536 machines using physical address extension or similar.
2537 Define CONFIG_PHYSMEM to access this basic support, which
2538 currently only supports clearing the memory.
2543 Define this variable to stop the system in case of a
2544 fatal error, so that you have to reset it manually.
2545 This is probably NOT a good idea for an embedded
2546 system where you want the system to reboot
2547 automatically as fast as possible, but it may be
2548 useful during development since you can try to debug
2549 the conditions that lead to the situation.
2551 CONFIG_NET_RETRY_COUNT
2553 This variable defines the number of retries for
2554 network operations like ARP, RARP, TFTP, or BOOTP
2555 before giving up the operation. If not defined, a
2556 default value of 5 is used.
2560 Timeout waiting for an ARP reply in milliseconds.
2564 Timeout in milliseconds used in NFS protocol.
2565 If you encounter "ERROR: Cannot umount" in nfs command,
2566 try longer timeout such as
2567 #define CONFIG_NFS_TIMEOUT 10000UL
2569 - Command Interpreter:
2570 CONFIG_AUTO_COMPLETE
2572 Enable auto completion of commands using TAB.
2574 Note that this feature has NOT been implemented yet
2575 for the "hush" shell.
2578 CONFIG_SYS_HUSH_PARSER
2580 Define this variable to enable the "hush" shell (from
2581 Busybox) as command line interpreter, thus enabling
2582 powerful command line syntax like
2583 if...then...else...fi conditionals or `&&' and '||'
2584 constructs ("shell scripts").
2586 If undefined, you get the old, much simpler behaviour
2587 with a somewhat smaller memory footprint.
2590 CONFIG_SYS_PROMPT_HUSH_PS2
2592 This defines the secondary prompt string, which is
2593 printed when the command interpreter needs more input
2594 to complete a command. Usually "> ".
2598 In the current implementation, the local variables
2599 space and global environment variables space are
2600 separated. Local variables are those you define by
2601 simply typing `name=value'. To access a local
2602 variable later on, you have write `$name' or
2603 `${name}'; to execute the contents of a variable
2604 directly type `$name' at the command prompt.
2606 Global environment variables are those you use
2607 setenv/printenv to work with. To run a command stored
2608 in such a variable, you need to use the run command,
2609 and you must not use the '$' sign to access them.
2611 To store commands and special characters in a
2612 variable, please use double quotation marks
2613 surrounding the whole text of the variable, instead
2614 of the backslashes before semicolons and special
2617 - Commandline Editing and History:
2618 CONFIG_CMDLINE_EDITING
2620 Enable editing and History functions for interactive
2621 commandline input operations
2623 - Default Environment:
2624 CONFIG_EXTRA_ENV_SETTINGS
2626 Define this to contain any number of null terminated
2627 strings (variable = value pairs) that will be part of
2628 the default environment compiled into the boot image.
2630 For example, place something like this in your
2631 board's config file:
2633 #define CONFIG_EXTRA_ENV_SETTINGS \
2637 Warning: This method is based on knowledge about the
2638 internal format how the environment is stored by the
2639 U-Boot code. This is NOT an official, exported
2640 interface! Although it is unlikely that this format
2641 will change soon, there is no guarantee either.
2642 You better know what you are doing here.
2644 Note: overly (ab)use of the default environment is
2645 discouraged. Make sure to check other ways to preset
2646 the environment like the "source" command or the
2649 CONFIG_ENV_VARS_UBOOT_CONFIG
2651 Define this in order to add variables describing the
2652 U-Boot build configuration to the default environment.
2653 These will be named arch, cpu, board, vendor, and soc.
2655 Enabling this option will cause the following to be defined:
2663 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2665 Define this in order to add variables describing certain
2666 run-time determined information about the hardware to the
2667 environment. These will be named board_name, board_rev.
2669 CONFIG_DELAY_ENVIRONMENT
2671 Normally the environment is loaded when the board is
2672 intialised so that it is available to U-Boot. This inhibits
2673 that so that the environment is not available until
2674 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2675 this is instead controlled by the value of
2676 /config/load-environment.
2678 - DataFlash Support:
2679 CONFIG_HAS_DATAFLASH
2681 Defining this option enables DataFlash features and
2682 allows to read/write in Dataflash via the standard
2685 - Serial Flash support
2688 Defining this option enables SPI flash commands
2689 'sf probe/read/write/erase/update'.
2691 Usage requires an initial 'probe' to define the serial
2692 flash parameters, followed by read/write/erase/update
2695 The following defaults may be provided by the platform
2696 to handle the common case when only a single serial
2697 flash is present on the system.
2699 CONFIG_SF_DEFAULT_BUS Bus identifier
2700 CONFIG_SF_DEFAULT_CS Chip-select
2701 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2702 CONFIG_SF_DEFAULT_SPEED in Hz
2706 Define this option to include a destructive SPI flash
2709 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2711 Define this option to use the Bank addr/Extended addr
2712 support on SPI flashes which has size > 16Mbytes.
2714 - SystemACE Support:
2717 Adding this option adds support for Xilinx SystemACE
2718 chips attached via some sort of local bus. The address
2719 of the chip must also be defined in the
2720 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2722 #define CONFIG_SYSTEMACE
2723 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2725 When SystemACE support is added, the "ace" device type
2726 becomes available to the fat commands, i.e. fatls.
2728 - TFTP Fixed UDP Port:
2731 If this is defined, the environment variable tftpsrcp
2732 is used to supply the TFTP UDP source port value.
2733 If tftpsrcp isn't defined, the normal pseudo-random port
2734 number generator is used.
2736 Also, the environment variable tftpdstp is used to supply
2737 the TFTP UDP destination port value. If tftpdstp isn't
2738 defined, the normal port 69 is used.
2740 The purpose for tftpsrcp is to allow a TFTP server to
2741 blindly start the TFTP transfer using the pre-configured
2742 target IP address and UDP port. This has the effect of
2743 "punching through" the (Windows XP) firewall, allowing
2744 the remainder of the TFTP transfer to proceed normally.
2745 A better solution is to properly configure the firewall,
2746 but sometimes that is not allowed.
2751 This enables a generic 'hash' command which can produce
2752 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2756 Enable the hash verify command (hash -v). This adds to code
2759 CONFIG_SHA1 - support SHA1 hashing
2760 CONFIG_SHA256 - support SHA256 hashing
2762 Note: There is also a sha1sum command, which should perhaps
2763 be deprecated in favour of 'hash sha1'.
2765 - Freescale i.MX specific commands:
2766 CONFIG_CMD_HDMIDETECT
2767 This enables 'hdmidet' command which returns true if an
2768 HDMI monitor is detected. This command is i.MX 6 specific.
2771 This enables the 'bmode' (bootmode) command for forcing
2772 a boot from specific media.
2774 This is useful for forcing the ROM's usb downloader to
2775 activate upon a watchdog reset which is nice when iterating
2776 on U-Boot. Using the reset button or running bmode normal
2777 will set it back to normal. This command currently
2778 supports i.MX53 and i.MX6.
2783 This enables the RSA algorithm used for FIT image verification
2784 in U-Boot. See doc/uImage/signature for more information.
2786 The signing part is build into mkimage regardless of this
2790 - Show boot progress:
2791 CONFIG_SHOW_BOOT_PROGRESS
2793 Defining this option allows to add some board-
2794 specific code (calling a user-provided function
2795 "show_boot_progress(int)") that enables you to show
2796 the system's boot progress on some display (for
2797 example, some LED's) on your board. At the moment,
2798 the following checkpoints are implemented:
2800 - Detailed boot stage timing
2802 Define this option to get detailed timing of each stage
2803 of the boot process.
2805 CONFIG_BOOTSTAGE_USER_COUNT
2806 This is the number of available user bootstage records.
2807 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2808 a new ID will be allocated from this stash. If you exceed
2809 the limit, recording will stop.
2811 CONFIG_BOOTSTAGE_REPORT
2812 Define this to print a report before boot, similar to this:
2814 Timer summary in microseconds:
2817 3,575,678 3,575,678 board_init_f start
2818 3,575,695 17 arch_cpu_init A9
2819 3,575,777 82 arch_cpu_init done
2820 3,659,598 83,821 board_init_r start
2821 3,910,375 250,777 main_loop
2822 29,916,167 26,005,792 bootm_start
2823 30,361,327 445,160 start_kernel
2825 CONFIG_CMD_BOOTSTAGE
2826 Add a 'bootstage' command which supports printing a report
2827 and un/stashing of bootstage data.
2829 CONFIG_BOOTSTAGE_FDT
2830 Stash the bootstage information in the FDT. A root 'bootstage'
2831 node is created with each bootstage id as a child. Each child
2832 has a 'name' property and either 'mark' containing the
2833 mark time in microsecond, or 'accum' containing the
2834 accumulated time for that bootstage id in microseconds.
2839 name = "board_init_f";
2848 Code in the Linux kernel can find this in /proc/devicetree.
2850 Legacy uImage format:
2853 1 common/cmd_bootm.c before attempting to boot an image
2854 -1 common/cmd_bootm.c Image header has bad magic number
2855 2 common/cmd_bootm.c Image header has correct magic number
2856 -2 common/cmd_bootm.c Image header has bad checksum
2857 3 common/cmd_bootm.c Image header has correct checksum
2858 -3 common/cmd_bootm.c Image data has bad checksum
2859 4 common/cmd_bootm.c Image data has correct checksum
2860 -4 common/cmd_bootm.c Image is for unsupported architecture
2861 5 common/cmd_bootm.c Architecture check OK
2862 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2863 6 common/cmd_bootm.c Image Type check OK
2864 -6 common/cmd_bootm.c gunzip uncompression error
2865 -7 common/cmd_bootm.c Unimplemented compression type
2866 7 common/cmd_bootm.c Uncompression OK
2867 8 common/cmd_bootm.c No uncompress/copy overwrite error
2868 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2870 9 common/image.c Start initial ramdisk verification
2871 -10 common/image.c Ramdisk header has bad magic number
2872 -11 common/image.c Ramdisk header has bad checksum
2873 10 common/image.c Ramdisk header is OK
2874 -12 common/image.c Ramdisk data has bad checksum
2875 11 common/image.c Ramdisk data has correct checksum
2876 12 common/image.c Ramdisk verification complete, start loading
2877 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2878 13 common/image.c Start multifile image verification
2879 14 common/image.c No initial ramdisk, no multifile, continue.
2881 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2883 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2884 -31 post/post.c POST test failed, detected by post_output_backlog()
2885 -32 post/post.c POST test failed, detected by post_run_single()
2887 34 common/cmd_doc.c before loading a Image from a DOC device
2888 -35 common/cmd_doc.c Bad usage of "doc" command
2889 35 common/cmd_doc.c correct usage of "doc" command
2890 -36 common/cmd_doc.c No boot device
2891 36 common/cmd_doc.c correct boot device
2892 -37 common/cmd_doc.c Unknown Chip ID on boot device
2893 37 common/cmd_doc.c correct chip ID found, device available
2894 -38 common/cmd_doc.c Read Error on boot device
2895 38 common/cmd_doc.c reading Image header from DOC device OK
2896 -39 common/cmd_doc.c Image header has bad magic number
2897 39 common/cmd_doc.c Image header has correct magic number
2898 -40 common/cmd_doc.c Error reading Image from DOC device
2899 40 common/cmd_doc.c Image header has correct magic number
2900 41 common/cmd_ide.c before loading a Image from a IDE device
2901 -42 common/cmd_ide.c Bad usage of "ide" command
2902 42 common/cmd_ide.c correct usage of "ide" command
2903 -43 common/cmd_ide.c No boot device
2904 43 common/cmd_ide.c boot device found
2905 -44 common/cmd_ide.c Device not available
2906 44 common/cmd_ide.c Device available
2907 -45 common/cmd_ide.c wrong partition selected
2908 45 common/cmd_ide.c partition selected
2909 -46 common/cmd_ide.c Unknown partition table
2910 46 common/cmd_ide.c valid partition table found
2911 -47 common/cmd_ide.c Invalid partition type
2912 47 common/cmd_ide.c correct partition type
2913 -48 common/cmd_ide.c Error reading Image Header on boot device
2914 48 common/cmd_ide.c reading Image Header from IDE device OK
2915 -49 common/cmd_ide.c Image header has bad magic number
2916 49 common/cmd_ide.c Image header has correct magic number
2917 -50 common/cmd_ide.c Image header has bad checksum
2918 50 common/cmd_ide.c Image header has correct checksum
2919 -51 common/cmd_ide.c Error reading Image from IDE device
2920 51 common/cmd_ide.c reading Image from IDE device OK
2921 52 common/cmd_nand.c before loading a Image from a NAND device
2922 -53 common/cmd_nand.c Bad usage of "nand" command
2923 53 common/cmd_nand.c correct usage of "nand" command
2924 -54 common/cmd_nand.c No boot device
2925 54 common/cmd_nand.c boot device found
2926 -55 common/cmd_nand.c Unknown Chip ID on boot device
2927 55 common/cmd_nand.c correct chip ID found, device available
2928 -56 common/cmd_nand.c Error reading Image Header on boot device
2929 56 common/cmd_nand.c reading Image Header from NAND device OK
2930 -57 common/cmd_nand.c Image header has bad magic number
2931 57 common/cmd_nand.c Image header has correct magic number
2932 -58 common/cmd_nand.c Error reading Image from NAND device
2933 58 common/cmd_nand.c reading Image from NAND device OK
2935 -60 common/env_common.c Environment has a bad CRC, using default
2937 64 net/eth.c starting with Ethernet configuration.
2938 -64 net/eth.c no Ethernet found.
2939 65 net/eth.c Ethernet found.
2941 -80 common/cmd_net.c usage wrong
2942 80 common/cmd_net.c before calling NetLoop()
2943 -81 common/cmd_net.c some error in NetLoop() occurred
2944 81 common/cmd_net.c NetLoop() back without error
2945 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2946 82 common/cmd_net.c trying automatic boot
2947 83 common/cmd_net.c running "source" command
2948 -83 common/cmd_net.c some error in automatic boot or "source" command
2949 84 common/cmd_net.c end without errors
2954 100 common/cmd_bootm.c Kernel FIT Image has correct format
2955 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2956 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2957 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2958 102 common/cmd_bootm.c Kernel unit name specified
2959 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2960 103 common/cmd_bootm.c Found configuration node
2961 104 common/cmd_bootm.c Got kernel subimage node offset
2962 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2963 105 common/cmd_bootm.c Kernel subimage hash verification OK
2964 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2965 106 common/cmd_bootm.c Architecture check OK
2966 -106 common/cmd_bootm.c Kernel subimage has wrong type
2967 107 common/cmd_bootm.c Kernel subimage type OK
2968 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2969 108 common/cmd_bootm.c Got kernel subimage data/size
2970 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2971 -109 common/cmd_bootm.c Can't get kernel subimage type
2972 -110 common/cmd_bootm.c Can't get kernel subimage comp
2973 -111 common/cmd_bootm.c Can't get kernel subimage os
2974 -112 common/cmd_bootm.c Can't get kernel subimage load address
2975 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2977 120 common/image.c Start initial ramdisk verification
2978 -120 common/image.c Ramdisk FIT image has incorrect format
2979 121 common/image.c Ramdisk FIT image has correct format
2980 122 common/image.c No ramdisk subimage unit name, using configuration
2981 -122 common/image.c Can't get configuration for ramdisk subimage
2982 123 common/image.c Ramdisk unit name specified
2983 -124 common/image.c Can't get ramdisk subimage node offset
2984 125 common/image.c Got ramdisk subimage node offset
2985 -125 common/image.c Ramdisk subimage hash verification failed
2986 126 common/image.c Ramdisk subimage hash verification OK
2987 -126 common/image.c Ramdisk subimage for unsupported architecture
2988 127 common/image.c Architecture check OK
2989 -127 common/image.c Can't get ramdisk subimage data/size
2990 128 common/image.c Got ramdisk subimage data/size
2991 129 common/image.c Can't get ramdisk load address
2992 -129 common/image.c Got ramdisk load address
2994 -130 common/cmd_doc.c Incorrect FIT image format
2995 131 common/cmd_doc.c FIT image format OK
2997 -140 common/cmd_ide.c Incorrect FIT image format
2998 141 common/cmd_ide.c FIT image format OK
3000 -150 common/cmd_nand.c Incorrect FIT image format
3001 151 common/cmd_nand.c FIT image format OK
3003 - FIT image support:
3005 Enable support for the FIT uImage format.
3007 CONFIG_FIT_BEST_MATCH
3008 When no configuration is explicitly selected, default to the
3009 one whose fdt's compatibility field best matches that of
3010 U-Boot itself. A match is considered "best" if it matches the
3011 most specific compatibility entry of U-Boot's fdt's root node.
3012 The order of entries in the configuration's fdt is ignored.
3014 CONFIG_FIT_SIGNATURE
3015 This option enables signature verification of FIT uImages,
3016 using a hash signed and verified using RSA. See
3017 doc/uImage.FIT/signature.txt for more details.
3019 - Standalone program support:
3020 CONFIG_STANDALONE_LOAD_ADDR
3022 This option defines a board specific value for the
3023 address where standalone program gets loaded, thus
3024 overwriting the architecture dependent default
3027 - Frame Buffer Address:
3030 Define CONFIG_FB_ADDR if you want to use specific
3031 address for frame buffer. This is typically the case
3032 when using a graphics controller has separate video
3033 memory. U-Boot will then place the frame buffer at
3034 the given address instead of dynamically reserving it
3035 in system RAM by calling lcd_setmem(), which grabs
3036 the memory for the frame buffer depending on the
3037 configured panel size.
3039 Please see board_init_f function.
3041 - Automatic software updates via TFTP server
3043 CONFIG_UPDATE_TFTP_CNT_MAX
3044 CONFIG_UPDATE_TFTP_MSEC_MAX
3046 These options enable and control the auto-update feature;
3047 for a more detailed description refer to doc/README.update.
3049 - MTD Support (mtdparts command, UBI support)
3052 Adds the MTD device infrastructure from the Linux kernel.
3053 Needed for mtdparts command support.
3055 CONFIG_MTD_PARTITIONS
3057 Adds the MTD partitioning infrastructure from the Linux
3058 kernel. Needed for UBI support.
3063 Adds commands for interacting with MTD partitions formatted
3064 with the UBI flash translation layer
3066 Requires also defining CONFIG_RBTREE
3068 CONFIG_UBI_SILENCE_MSG
3070 Make the verbose messages from UBI stop printing. This leaves
3071 warnings and errors enabled.
3076 Adds commands for interacting with UBI volumes formatted as
3077 UBIFS. UBIFS is read-only in u-boot.
3079 Requires UBI support as well as CONFIG_LZO
3081 CONFIG_UBIFS_SILENCE_MSG
3083 Make the verbose messages from UBIFS stop printing. This leaves
3084 warnings and errors enabled.
3088 Enable building of SPL globally.
3091 LDSCRIPT for linking the SPL binary.
3093 CONFIG_SPL_MAX_FOOTPRINT
3094 Maximum size in memory allocated to the SPL, BSS included.
3095 When defined, the linker checks that the actual memory
3096 used by SPL from _start to __bss_end does not exceed it.
3097 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3098 must not be both defined at the same time.
3101 Maximum size of the SPL image (text, data, rodata, and
3102 linker lists sections), BSS excluded.
3103 When defined, the linker checks that the actual size does
3106 CONFIG_SPL_TEXT_BASE
3107 TEXT_BASE for linking the SPL binary.
3109 CONFIG_SPL_RELOC_TEXT_BASE
3110 Address to relocate to. If unspecified, this is equal to
3111 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3113 CONFIG_SPL_BSS_START_ADDR
3114 Link address for the BSS within the SPL binary.
3116 CONFIG_SPL_BSS_MAX_SIZE
3117 Maximum size in memory allocated to the SPL BSS.
3118 When defined, the linker checks that the actual memory used
3119 by SPL from __bss_start to __bss_end does not exceed it.
3120 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3121 must not be both defined at the same time.
3124 Adress of the start of the stack SPL will use
3126 CONFIG_SPL_RELOC_STACK
3127 Adress of the start of the stack SPL will use after
3128 relocation. If unspecified, this is equal to
3131 CONFIG_SYS_SPL_MALLOC_START
3132 Starting address of the malloc pool used in SPL.
3134 CONFIG_SYS_SPL_MALLOC_SIZE
3135 The size of the malloc pool used in SPL.
3137 CONFIG_SPL_FRAMEWORK
3138 Enable the SPL framework under common/. This framework
3139 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3140 NAND loading of the Linux Kernel.
3142 CONFIG_SPL_DISPLAY_PRINT
3143 For ARM, enable an optional function to print more information
3144 about the running system.
3146 CONFIG_SPL_INIT_MINIMAL
3147 Arch init code should be built for a very small image
3149 CONFIG_SPL_LIBCOMMON_SUPPORT
3150 Support for common/libcommon.o in SPL binary
3152 CONFIG_SPL_LIBDISK_SUPPORT
3153 Support for disk/libdisk.o in SPL binary
3155 CONFIG_SPL_I2C_SUPPORT
3156 Support for drivers/i2c/libi2c.o in SPL binary
3158 CONFIG_SPL_GPIO_SUPPORT
3159 Support for drivers/gpio/libgpio.o in SPL binary
3161 CONFIG_SPL_MMC_SUPPORT
3162 Support for drivers/mmc/libmmc.o in SPL binary
3164 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3165 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3166 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3167 Address, size and partition on the MMC to load U-Boot from
3168 when the MMC is being used in raw mode.
3170 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3171 Sector to load kernel uImage from when MMC is being
3172 used in raw mode (for Falcon mode)
3174 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3175 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3176 Sector and number of sectors to load kernel argument
3177 parameters from when MMC is being used in raw mode
3180 CONFIG_SPL_FAT_SUPPORT
3181 Support for fs/fat/libfat.o in SPL binary
3183 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3184 Filename to read to load U-Boot when reading from FAT
3186 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3187 Filename to read to load kernel uImage when reading
3188 from FAT (for Falcon mode)
3190 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3191 Filename to read to load kernel argument parameters
3192 when reading from FAT (for Falcon mode)
3194 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3195 Set this for NAND SPL on PPC mpc83xx targets, so that
3196 start.S waits for the rest of the SPL to load before
3197 continuing (the hardware starts execution after just
3198 loading the first page rather than the full 4K).
3200 CONFIG_SPL_NAND_BASE
3201 Include nand_base.c in the SPL. Requires
3202 CONFIG_SPL_NAND_DRIVERS.
3204 CONFIG_SPL_NAND_DRIVERS
3205 SPL uses normal NAND drivers, not minimal drivers.
3208 Include standard software ECC in the SPL
3210 CONFIG_SPL_NAND_SIMPLE
3211 Support for NAND boot using simple NAND drivers that
3212 expose the cmd_ctrl() interface.
3214 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3215 Set for the SPL on PPC mpc8xxx targets, support for
3216 drivers/ddr/fsl/libddr.o in SPL binary.
3218 CONFIG_SPL_COMMON_INIT_DDR
3219 Set for common ddr init with serial presence detect in
3222 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3223 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3224 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3225 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3226 CONFIG_SYS_NAND_ECCBYTES
3227 Defines the size and behavior of the NAND that SPL uses
3230 CONFIG_SYS_NAND_U_BOOT_OFFS
3231 Location in NAND to read U-Boot from
3233 CONFIG_SYS_NAND_U_BOOT_DST
3234 Location in memory to load U-Boot to
3236 CONFIG_SYS_NAND_U_BOOT_SIZE
3237 Size of image to load
3239 CONFIG_SYS_NAND_U_BOOT_START
3240 Entry point in loaded image to jump to
3242 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3243 Define this if you need to first read the OOB and then the
3244 data. This is used for example on davinci plattforms.
3246 CONFIG_SPL_OMAP3_ID_NAND
3247 Support for an OMAP3-specific set of functions to return the
3248 ID and MFR of the first attached NAND chip, if present.
3250 CONFIG_SPL_SERIAL_SUPPORT
3251 Support for drivers/serial/libserial.o in SPL binary
3253 CONFIG_SPL_SPI_FLASH_SUPPORT
3254 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3256 CONFIG_SPL_SPI_SUPPORT
3257 Support for drivers/spi/libspi.o in SPL binary
3259 CONFIG_SPL_RAM_DEVICE
3260 Support for running image already present in ram, in SPL binary
3262 CONFIG_SPL_LIBGENERIC_SUPPORT
3263 Support for lib/libgeneric.o in SPL binary
3265 CONFIG_SPL_ENV_SUPPORT
3266 Support for the environment operating in SPL binary
3268 CONFIG_SPL_NET_SUPPORT
3269 Support for the net/libnet.o in SPL binary.
3270 It conflicts with SPL env from storage medium specified by
3271 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3274 Image offset to which the SPL should be padded before appending
3275 the SPL payload. By default, this is defined as
3276 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3277 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3278 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3281 Final target image containing SPL and payload. Some SPLs
3282 use an arch-specific makefile fragment instead, for
3283 example if more than one image needs to be produced.
3285 CONFIG_FIT_SPL_PRINT
3286 Printing information about a FIT image adds quite a bit of
3287 code to SPL. So this is normally disabled in SPL. Use this
3288 option to re-enable it. This will affect the output of the
3289 bootm command when booting a FIT image.
3293 Enable building of TPL globally.
3296 Image offset to which the TPL should be padded before appending
3297 the TPL payload. By default, this is defined as
3298 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3299 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3300 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3305 [so far only for SMDK2400 boards]
3307 - Modem support enable:
3308 CONFIG_MODEM_SUPPORT
3310 - RTS/CTS Flow control enable:
3313 - Modem debug support:
3314 CONFIG_MODEM_SUPPORT_DEBUG
3316 Enables debugging stuff (char screen[1024], dbg())
3317 for modem support. Useful only with BDI2000.
3319 - Interrupt support (PPC):
3321 There are common interrupt_init() and timer_interrupt()
3322 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3323 for CPU specific initialization. interrupt_init_cpu()
3324 should set decrementer_count to appropriate value. If
3325 CPU resets decrementer automatically after interrupt
3326 (ppc4xx) it should set decrementer_count to zero.
3327 timer_interrupt() calls timer_interrupt_cpu() for CPU
3328 specific handling. If board has watchdog / status_led
3329 / other_activity_monitor it works automatically from
3330 general timer_interrupt().
3334 In the target system modem support is enabled when a
3335 specific key (key combination) is pressed during
3336 power-on. Otherwise U-Boot will boot normally
3337 (autoboot). The key_pressed() function is called from
3338 board_init(). Currently key_pressed() is a dummy
3339 function, returning 1 and thus enabling modem
3342 If there are no modem init strings in the
3343 environment, U-Boot proceed to autoboot; the
3344 previous output (banner, info printfs) will be
3347 See also: doc/README.Modem
3349 Board initialization settings:
3350 ------------------------------
3352 During Initialization u-boot calls a number of board specific functions
3353 to allow the preparation of board specific prerequisites, e.g. pin setup
3354 before drivers are initialized. To enable these callbacks the
3355 following configuration macros have to be defined. Currently this is
3356 architecture specific, so please check arch/your_architecture/lib/board.c
3357 typically in board_init_f() and board_init_r().
3359 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3360 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3361 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3362 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3364 Configuration Settings:
3365 -----------------------
3367 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3368 undefine this when you're short of memory.
3370 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3371 width of the commands listed in the 'help' command output.
3373 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3374 prompt for user input.
3376 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3378 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3380 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3382 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3383 the application (usually a Linux kernel) when it is
3386 - CONFIG_SYS_BAUDRATE_TABLE:
3387 List of legal baudrate settings for this board.
3389 - CONFIG_SYS_CONSOLE_INFO_QUIET
3390 Suppress display of console information at boot.
3392 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3393 If the board specific function
3394 extern int overwrite_console (void);
3395 returns 1, the stdin, stderr and stdout are switched to the
3396 serial port, else the settings in the environment are used.
3398 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3399 Enable the call to overwrite_console().
3401 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3402 Enable overwrite of previous console environment settings.
3404 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3405 Begin and End addresses of the area used by the
3408 - CONFIG_SYS_ALT_MEMTEST:
3409 Enable an alternate, more extensive memory test.
3411 - CONFIG_SYS_MEMTEST_SCRATCH:
3412 Scratch address used by the alternate memory test
3413 You only need to set this if address zero isn't writeable
3415 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3416 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3417 this specified memory area will get subtracted from the top
3418 (end) of RAM and won't get "touched" at all by U-Boot. By
3419 fixing up gd->ram_size the Linux kernel should gets passed
3420 the now "corrected" memory size and won't touch it either.
3421 This should work for arch/ppc and arch/powerpc. Only Linux
3422 board ports in arch/powerpc with bootwrapper support that
3423 recalculate the memory size from the SDRAM controller setup
3424 will have to get fixed in Linux additionally.
3426 This option can be used as a workaround for the 440EPx/GRx
3427 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3430 WARNING: Please make sure that this value is a multiple of
3431 the Linux page size (normally 4k). If this is not the case,
3432 then the end address of the Linux memory will be located at a
3433 non page size aligned address and this could cause major
3436 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3437 Enable temporary baudrate change while serial download
3439 - CONFIG_SYS_SDRAM_BASE:
3440 Physical start address of SDRAM. _Must_ be 0 here.
3442 - CONFIG_SYS_MBIO_BASE:
3443 Physical start address of Motherboard I/O (if using a
3446 - CONFIG_SYS_FLASH_BASE:
3447 Physical start address of Flash memory.
3449 - CONFIG_SYS_MONITOR_BASE:
3450 Physical start address of boot monitor code (set by
3451 make config files to be same as the text base address
3452 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3453 CONFIG_SYS_FLASH_BASE when booting from flash.
3455 - CONFIG_SYS_MONITOR_LEN:
3456 Size of memory reserved for monitor code, used to
3457 determine _at_compile_time_ (!) if the environment is
3458 embedded within the U-Boot image, or in a separate
3461 - CONFIG_SYS_MALLOC_LEN:
3462 Size of DRAM reserved for malloc() use.
3464 - CONFIG_SYS_BOOTM_LEN:
3465 Normally compressed uImages are limited to an
3466 uncompressed size of 8 MBytes. If this is not enough,
3467 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3468 to adjust this setting to your needs.
3470 - CONFIG_SYS_BOOTMAPSZ:
3471 Maximum size of memory mapped by the startup code of
3472 the Linux kernel; all data that must be processed by
3473 the Linux kernel (bd_info, boot arguments, FDT blob if
3474 used) must be put below this limit, unless "bootm_low"
3475 environment variable is defined and non-zero. In such case
3476 all data for the Linux kernel must be between "bootm_low"
3477 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3478 variable "bootm_mapsize" will override the value of
3479 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3480 then the value in "bootm_size" will be used instead.
3482 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3483 Enable initrd_high functionality. If defined then the
3484 initrd_high feature is enabled and the bootm ramdisk subcommand
3487 - CONFIG_SYS_BOOT_GET_CMDLINE:
3488 Enables allocating and saving kernel cmdline in space between
3489 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3491 - CONFIG_SYS_BOOT_GET_KBD:
3492 Enables allocating and saving a kernel copy of the bd_info in
3493 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3495 - CONFIG_SYS_MAX_FLASH_BANKS:
3496 Max number of Flash memory banks
3498 - CONFIG_SYS_MAX_FLASH_SECT:
3499 Max number of sectors on a Flash chip
3501 - CONFIG_SYS_FLASH_ERASE_TOUT:
3502 Timeout for Flash erase operations (in ms)
3504 - CONFIG_SYS_FLASH_WRITE_TOUT:
3505 Timeout for Flash write operations (in ms)
3507 - CONFIG_SYS_FLASH_LOCK_TOUT
3508 Timeout for Flash set sector lock bit operation (in ms)
3510 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3511 Timeout for Flash clear lock bits operation (in ms)
3513 - CONFIG_SYS_FLASH_PROTECTION
3514 If defined, hardware flash sectors protection is used
3515 instead of U-Boot software protection.
3517 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3519 Enable TFTP transfers directly to flash memory;
3520 without this option such a download has to be
3521 performed in two steps: (1) download to RAM, and (2)
3522 copy from RAM to flash.
3524 The two-step approach is usually more reliable, since
3525 you can check if the download worked before you erase
3526 the flash, but in some situations (when system RAM is
3527 too limited to allow for a temporary copy of the
3528 downloaded image) this option may be very useful.
3530 - CONFIG_SYS_FLASH_CFI:
3531 Define if the flash driver uses extra elements in the
3532 common flash structure for storing flash geometry.
3534 - CONFIG_FLASH_CFI_DRIVER
3535 This option also enables the building of the cfi_flash driver
3536 in the drivers directory
3538 - CONFIG_FLASH_CFI_MTD
3539 This option enables the building of the cfi_mtd driver
3540 in the drivers directory. The driver exports CFI flash
3543 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3544 Use buffered writes to flash.
3546 - CONFIG_FLASH_SPANSION_S29WS_N
3547 s29ws-n MirrorBit flash has non-standard addresses for buffered
3550 - CONFIG_SYS_FLASH_QUIET_TEST
3551 If this option is defined, the common CFI flash doesn't
3552 print it's warning upon not recognized FLASH banks. This
3553 is useful, if some of the configured banks are only
3554 optionally available.
3556 - CONFIG_FLASH_SHOW_PROGRESS
3557 If defined (must be an integer), print out countdown
3558 digits and dots. Recommended value: 45 (9..1) for 80
3559 column displays, 15 (3..1) for 40 column displays.
3561 - CONFIG_FLASH_VERIFY
3562 If defined, the content of the flash (destination) is compared
3563 against the source after the write operation. An error message
3564 will be printed when the contents are not identical.
3565 Please note that this option is useless in nearly all cases,
3566 since such flash programming errors usually are detected earlier
3567 while unprotecting/erasing/programming. Please only enable
3568 this option if you really know what you are doing.
3570 - CONFIG_SYS_RX_ETH_BUFFER:
3571 Defines the number of Ethernet receive buffers. On some
3572 Ethernet controllers it is recommended to set this value
3573 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3574 buffers can be full shortly after enabling the interface
3575 on high Ethernet traffic.
3576 Defaults to 4 if not defined.
3578 - CONFIG_ENV_MAX_ENTRIES
3580 Maximum number of entries in the hash table that is used
3581 internally to store the environment settings. The default
3582 setting is supposed to be generous and should work in most
3583 cases. This setting can be used to tune behaviour; see
3584 lib/hashtable.c for details.
3586 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3587 - CONFIG_ENV_FLAGS_LIST_STATIC
3588 Enable validation of the values given to environment variables when
3589 calling env set. Variables can be restricted to only decimal,
3590 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3591 the variables can also be restricted to IP address or MAC address.
3593 The format of the list is:
3594 type_attribute = [s|d|x|b|i|m]
3595 access_atribute = [a|r|o|c]
3596 attributes = type_attribute[access_atribute]
3597 entry = variable_name[:attributes]
3600 The type attributes are:
3601 s - String (default)
3604 b - Boolean ([1yYtT|0nNfF])
3608 The access attributes are:
3614 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3615 Define this to a list (string) to define the ".flags"
3616 envirnoment variable in the default or embedded environment.
3618 - CONFIG_ENV_FLAGS_LIST_STATIC
3619 Define this to a list (string) to define validation that
3620 should be done if an entry is not found in the ".flags"
3621 environment variable. To override a setting in the static
3622 list, simply add an entry for the same variable name to the
3625 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3626 If defined, don't allow the -f switch to env set override variable
3629 - CONFIG_SYS_GENERIC_BOARD
3630 This selects the architecture-generic board system instead of the
3631 architecture-specific board files. It is intended to move boards
3632 to this new framework over time. Defining this will disable the
3633 arch/foo/lib/board.c file and use common/board_f.c and
3634 common/board_r.c instead. To use this option your architecture
3635 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3636 its config.mk file). If you find problems enabling this option on
3637 your board please report the problem and send patches!
3639 - CONFIG_SYS_SYM_OFFSETS
3640 This is set by architectures that use offsets for link symbols
3641 instead of absolute values. So bss_start is obtained using an
3642 offset _bss_start_ofs from CONFIG_SYS_TEXT_BASE, rather than
3643 directly. You should not need to touch this setting.
3645 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3646 This is set by OMAP boards for the max time that reset should
3647 be asserted. See doc/README.omap-reset-time for details on how
3648 the value can be calulated on a given board.
3650 The following definitions that deal with the placement and management
3651 of environment data (variable area); in general, we support the
3652 following configurations:
3654 - CONFIG_BUILD_ENVCRC:
3656 Builds up envcrc with the target environment so that external utils
3657 may easily extract it and embed it in final U-Boot images.
3659 - CONFIG_ENV_IS_IN_FLASH:
3661 Define this if the environment is in flash memory.
3663 a) The environment occupies one whole flash sector, which is
3664 "embedded" in the text segment with the U-Boot code. This
3665 happens usually with "bottom boot sector" or "top boot
3666 sector" type flash chips, which have several smaller
3667 sectors at the start or the end. For instance, such a
3668 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3669 such a case you would place the environment in one of the
3670 4 kB sectors - with U-Boot code before and after it. With
3671 "top boot sector" type flash chips, you would put the
3672 environment in one of the last sectors, leaving a gap
3673 between U-Boot and the environment.
3675 - CONFIG_ENV_OFFSET:
3677 Offset of environment data (variable area) to the
3678 beginning of flash memory; for instance, with bottom boot
3679 type flash chips the second sector can be used: the offset
3680 for this sector is given here.
3682 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3686 This is just another way to specify the start address of
3687 the flash sector containing the environment (instead of
3690 - CONFIG_ENV_SECT_SIZE:
3692 Size of the sector containing the environment.
3695 b) Sometimes flash chips have few, equal sized, BIG sectors.
3696 In such a case you don't want to spend a whole sector for
3701 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3702 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3703 of this flash sector for the environment. This saves
3704 memory for the RAM copy of the environment.
3706 It may also save flash memory if you decide to use this
3707 when your environment is "embedded" within U-Boot code,
3708 since then the remainder of the flash sector could be used
3709 for U-Boot code. It should be pointed out that this is
3710 STRONGLY DISCOURAGED from a robustness point of view:
3711 updating the environment in flash makes it always
3712 necessary to erase the WHOLE sector. If something goes
3713 wrong before the contents has been restored from a copy in
3714 RAM, your target system will be dead.
3716 - CONFIG_ENV_ADDR_REDUND
3717 CONFIG_ENV_SIZE_REDUND
3719 These settings describe a second storage area used to hold
3720 a redundant copy of the environment data, so that there is
3721 a valid backup copy in case there is a power failure during
3722 a "saveenv" operation.
3724 BE CAREFUL! Any changes to the flash layout, and some changes to the
3725 source code will make it necessary to adapt <board>/u-boot.lds*
3729 - CONFIG_ENV_IS_IN_NVRAM:
3731 Define this if you have some non-volatile memory device
3732 (NVRAM, battery buffered SRAM) which you want to use for the
3738 These two #defines are used to determine the memory area you
3739 want to use for environment. It is assumed that this memory
3740 can just be read and written to, without any special
3743 BE CAREFUL! The first access to the environment happens quite early
3744 in U-Boot initalization (when we try to get the setting of for the
3745 console baudrate). You *MUST* have mapped your NVRAM area then, or
3748 Please note that even with NVRAM we still use a copy of the
3749 environment in RAM: we could work on NVRAM directly, but we want to
3750 keep settings there always unmodified except somebody uses "saveenv"
3751 to save the current settings.
3754 - CONFIG_ENV_IS_IN_EEPROM:
3756 Use this if you have an EEPROM or similar serial access
3757 device and a driver for it.
3759 - CONFIG_ENV_OFFSET:
3762 These two #defines specify the offset and size of the
3763 environment area within the total memory of your EEPROM.
3765 - CONFIG_SYS_I2C_EEPROM_ADDR:
3766 If defined, specified the chip address of the EEPROM device.
3767 The default address is zero.
3769 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3770 If defined, the number of bits used to address bytes in a
3771 single page in the EEPROM device. A 64 byte page, for example
3772 would require six bits.
3774 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3775 If defined, the number of milliseconds to delay between
3776 page writes. The default is zero milliseconds.
3778 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3779 The length in bytes of the EEPROM memory array address. Note
3780 that this is NOT the chip address length!
3782 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3783 EEPROM chips that implement "address overflow" are ones
3784 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3785 address and the extra bits end up in the "chip address" bit
3786 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3789 Note that we consider the length of the address field to
3790 still be one byte because the extra address bits are hidden
3791 in the chip address.
3793 - CONFIG_SYS_EEPROM_SIZE:
3794 The size in bytes of the EEPROM device.
3796 - CONFIG_ENV_EEPROM_IS_ON_I2C
3797 define this, if you have I2C and SPI activated, and your
3798 EEPROM, which holds the environment, is on the I2C bus.
3800 - CONFIG_I2C_ENV_EEPROM_BUS
3801 if you have an Environment on an EEPROM reached over
3802 I2C muxes, you can define here, how to reach this
3803 EEPROM. For example:
3805 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3807 EEPROM which holds the environment, is reached over
3808 a pca9547 i2c mux with address 0x70, channel 3.
3810 - CONFIG_ENV_IS_IN_DATAFLASH:
3812 Define this if you have a DataFlash memory device which you
3813 want to use for the environment.
3815 - CONFIG_ENV_OFFSET:
3819 These three #defines specify the offset and size of the
3820 environment area within the total memory of your DataFlash placed
3821 at the specified address.
3823 - CONFIG_ENV_IS_IN_REMOTE:
3825 Define this if you have a remote memory space which you
3826 want to use for the local device's environment.
3831 These two #defines specify the address and size of the
3832 environment area within the remote memory space. The
3833 local device can get the environment from remote memory
3834 space by SRIO or PCIE links.
3836 BE CAREFUL! For some special cases, the local device can not use
3837 "saveenv" command. For example, the local device will get the
3838 environment stored in a remote NOR flash by SRIO or PCIE link,
3839 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3841 - CONFIG_ENV_IS_IN_NAND:
3843 Define this if you have a NAND device which you want to use
3844 for the environment.
3846 - CONFIG_ENV_OFFSET:
3849 These two #defines specify the offset and size of the environment
3850 area within the first NAND device. CONFIG_ENV_OFFSET must be
3851 aligned to an erase block boundary.
3853 - CONFIG_ENV_OFFSET_REDUND (optional):
3855 This setting describes a second storage area of CONFIG_ENV_SIZE
3856 size used to hold a redundant copy of the environment data, so
3857 that there is a valid backup copy in case there is a power failure
3858 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3859 aligned to an erase block boundary.
3861 - CONFIG_ENV_RANGE (optional):
3863 Specifies the length of the region in which the environment
3864 can be written. This should be a multiple of the NAND device's
3865 block size. Specifying a range with more erase blocks than
3866 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3867 the range to be avoided.
3869 - CONFIG_ENV_OFFSET_OOB (optional):
3871 Enables support for dynamically retrieving the offset of the
3872 environment from block zero's out-of-band data. The
3873 "nand env.oob" command can be used to record this offset.
3874 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3875 using CONFIG_ENV_OFFSET_OOB.
3877 - CONFIG_NAND_ENV_DST
3879 Defines address in RAM to which the nand_spl code should copy the
3880 environment. If redundant environment is used, it will be copied to
3881 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3883 - CONFIG_ENV_IS_IN_UBI:
3885 Define this if you have an UBI volume that you want to use for the
3886 environment. This has the benefit of wear-leveling the environment
3887 accesses, which is important on NAND.
3889 - CONFIG_ENV_UBI_PART:
3891 Define this to a string that is the mtd partition containing the UBI.
3893 - CONFIG_ENV_UBI_VOLUME:
3895 Define this to the name of the volume that you want to store the
3898 - CONFIG_ENV_UBI_VOLUME_REDUND:
3900 Define this to the name of another volume to store a second copy of
3901 the environment in. This will enable redundant environments in UBI.
3902 It is assumed that both volumes are in the same MTD partition.
3904 - CONFIG_UBI_SILENCE_MSG
3905 - CONFIG_UBIFS_SILENCE_MSG
3907 You will probably want to define these to avoid a really noisy system
3908 when storing the env in UBI.
3910 - CONFIG_ENV_IS_IN_MMC:
3912 Define this if you have an MMC device which you want to use for the
3915 - CONFIG_SYS_MMC_ENV_DEV:
3917 Specifies which MMC device the environment is stored in.
3919 - CONFIG_SYS_MMC_ENV_PART (optional):
3921 Specifies which MMC partition the environment is stored in. If not
3922 set, defaults to partition 0, the user area. Common values might be
3923 1 (first MMC boot partition), 2 (second MMC boot partition).
3925 - CONFIG_ENV_OFFSET:
3928 These two #defines specify the offset and size of the environment
3929 area within the specified MMC device.
3931 If offset is positive (the usual case), it is treated as relative to
3932 the start of the MMC partition. If offset is negative, it is treated
3933 as relative to the end of the MMC partition. This can be useful if
3934 your board may be fitted with different MMC devices, which have
3935 different sizes for the MMC partitions, and you always want the
3936 environment placed at the very end of the partition, to leave the
3937 maximum possible space before it, to store other data.
3939 These two values are in units of bytes, but must be aligned to an
3940 MMC sector boundary.
3942 - CONFIG_ENV_OFFSET_REDUND (optional):
3944 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
3945 hold a redundant copy of the environment data. This provides a
3946 valid backup copy in case the other copy is corrupted, e.g. due
3947 to a power failure during a "saveenv" operation.
3949 This value may also be positive or negative; this is handled in the
3950 same way as CONFIG_ENV_OFFSET.
3952 This value is also in units of bytes, but must also be aligned to
3953 an MMC sector boundary.
3955 - CONFIG_ENV_SIZE_REDUND (optional):
3957 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
3958 set. If this value is set, it must be set to the same value as
3961 - CONFIG_SYS_SPI_INIT_OFFSET
3963 Defines offset to the initial SPI buffer area in DPRAM. The
3964 area is used at an early stage (ROM part) if the environment
3965 is configured to reside in the SPI EEPROM: We need a 520 byte
3966 scratch DPRAM area. It is used between the two initialization
3967 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3968 to be a good choice since it makes it far enough from the
3969 start of the data area as well as from the stack pointer.
3971 Please note that the environment is read-only until the monitor
3972 has been relocated to RAM and a RAM copy of the environment has been
3973 created; also, when using EEPROM you will have to use getenv_f()
3974 until then to read environment variables.
3976 The environment is protected by a CRC32 checksum. Before the monitor
3977 is relocated into RAM, as a result of a bad CRC you will be working
3978 with the compiled-in default environment - *silently*!!! [This is
3979 necessary, because the first environment variable we need is the
3980 "baudrate" setting for the console - if we have a bad CRC, we don't
3981 have any device yet where we could complain.]
3983 Note: once the monitor has been relocated, then it will complain if
3984 the default environment is used; a new CRC is computed as soon as you
3985 use the "saveenv" command to store a valid environment.
3987 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3988 Echo the inverted Ethernet link state to the fault LED.
3990 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3991 also needs to be defined.
3993 - CONFIG_SYS_FAULT_MII_ADDR:
3994 MII address of the PHY to check for the Ethernet link state.
3996 - CONFIG_NS16550_MIN_FUNCTIONS:
3997 Define this if you desire to only have use of the NS16550_init
3998 and NS16550_putc functions for the serial driver located at
3999 drivers/serial/ns16550.c. This option is useful for saving
4000 space for already greatly restricted images, including but not
4001 limited to NAND_SPL configurations.
4003 - CONFIG_DISPLAY_BOARDINFO
4004 Display information about the board that U-Boot is running on
4005 when U-Boot starts up. The board function checkboard() is called
4008 - CONFIG_DISPLAY_BOARDINFO_LATE
4009 Similar to the previous option, but display this information
4010 later, once stdio is running and output goes to the LCD, if
4013 Low Level (hardware related) configuration options:
4014 ---------------------------------------------------
4016 - CONFIG_SYS_CACHELINE_SIZE:
4017 Cache Line Size of the CPU.
4019 - CONFIG_SYS_DEFAULT_IMMR:
4020 Default address of the IMMR after system reset.
4022 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4023 and RPXsuper) to be able to adjust the position of
4024 the IMMR register after a reset.
4026 - CONFIG_SYS_CCSRBAR_DEFAULT:
4027 Default (power-on reset) physical address of CCSR on Freescale
4030 - CONFIG_SYS_CCSRBAR:
4031 Virtual address of CCSR. On a 32-bit build, this is typically
4032 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4034 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4035 for cross-platform code that uses that macro instead.
4037 - CONFIG_SYS_CCSRBAR_PHYS:
4038 Physical address of CCSR. CCSR can be relocated to a new
4039 physical address, if desired. In this case, this macro should
4040 be set to that address. Otherwise, it should be set to the
4041 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4042 is typically relocated on 36-bit builds. It is recommended
4043 that this macro be defined via the _HIGH and _LOW macros:
4045 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4046 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4048 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4049 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4050 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4051 used in assembly code, so it must not contain typecasts or
4052 integer size suffixes (e.g. "ULL").
4054 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4055 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4056 used in assembly code, so it must not contain typecasts or
4057 integer size suffixes (e.g. "ULL").
4059 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4060 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4061 forced to a value that ensures that CCSR is not relocated.
4063 - Floppy Disk Support:
4064 CONFIG_SYS_FDC_DRIVE_NUMBER
4066 the default drive number (default value 0)
4068 CONFIG_SYS_ISA_IO_STRIDE
4070 defines the spacing between FDC chipset registers
4073 CONFIG_SYS_ISA_IO_OFFSET
4075 defines the offset of register from address. It
4076 depends on which part of the data bus is connected to
4077 the FDC chipset. (default value 0)
4079 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4080 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4083 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4084 fdc_hw_init() is called at the beginning of the FDC
4085 setup. fdc_hw_init() must be provided by the board
4086 source code. It is used to make hardware dependant
4090 Most IDE controllers were designed to be connected with PCI
4091 interface. Only few of them were designed for AHB interface.
4092 When software is doing ATA command and data transfer to
4093 IDE devices through IDE-AHB controller, some additional
4094 registers accessing to these kind of IDE-AHB controller
4097 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4098 DO NOT CHANGE unless you know exactly what you're
4099 doing! (11-4) [MPC8xx/82xx systems only]
4101 - CONFIG_SYS_INIT_RAM_ADDR:
4103 Start address of memory area that can be used for
4104 initial data and stack; please note that this must be
4105 writable memory that is working WITHOUT special
4106 initialization, i. e. you CANNOT use normal RAM which
4107 will become available only after programming the
4108 memory controller and running certain initialization
4111 U-Boot uses the following memory types:
4112 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4113 - MPC824X: data cache
4114 - PPC4xx: data cache
4116 - CONFIG_SYS_GBL_DATA_OFFSET:
4118 Offset of the initial data structure in the memory
4119 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4120 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4121 data is located at the end of the available space
4122 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4123 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4124 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4125 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4128 On the MPC824X (or other systems that use the data
4129 cache for initial memory) the address chosen for
4130 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4131 point to an otherwise UNUSED address space between
4132 the top of RAM and the start of the PCI space.
4134 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4136 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4138 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4140 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4142 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4144 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4146 - CONFIG_SYS_OR_TIMING_SDRAM:
4149 - CONFIG_SYS_MAMR_PTA:
4150 periodic timer for refresh
4152 - CONFIG_SYS_DER: Debug Event Register (37-47)
4154 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4155 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4156 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4157 CONFIG_SYS_BR1_PRELIM:
4158 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4160 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4161 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4162 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4163 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4165 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4166 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4167 Machine Mode Register and Memory Periodic Timer
4168 Prescaler definitions (SDRAM timing)
4170 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4171 enable I2C microcode relocation patch (MPC8xx);
4172 define relocation offset in DPRAM [DSP2]
4174 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4175 enable SMC microcode relocation patch (MPC8xx);
4176 define relocation offset in DPRAM [SMC1]
4178 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4179 enable SPI microcode relocation patch (MPC8xx);
4180 define relocation offset in DPRAM [SCC4]
4182 - CONFIG_SYS_USE_OSCCLK:
4183 Use OSCM clock mode on MBX8xx board. Be careful,
4184 wrong setting might damage your board. Read
4185 doc/README.MBX before setting this variable!
4187 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4188 Offset of the bootmode word in DPRAM used by post
4189 (Power On Self Tests). This definition overrides
4190 #define'd default value in commproc.h resp.
4193 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4194 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4195 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4196 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4197 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4198 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4199 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4200 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4201 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4203 - CONFIG_PCI_DISABLE_PCIE:
4204 Disable PCI-Express on systems where it is supported but not
4207 - CONFIG_PCI_ENUM_ONLY
4208 Only scan through and get the devices on the busses.
4209 Don't do any setup work, presumably because someone or
4210 something has already done it, and we don't need to do it
4211 a second time. Useful for platforms that are pre-booted
4212 by coreboot or similar.
4214 - CONFIG_PCI_INDIRECT_BRIDGE:
4215 Enable support for indirect PCI bridges.
4218 Chip has SRIO or not
4221 Board has SRIO 1 port available
4224 Board has SRIO 2 port available
4226 - CONFIG_SRIO_PCIE_BOOT_MASTER
4227 Board can support master function for Boot from SRIO and PCIE
4229 - CONFIG_SYS_SRIOn_MEM_VIRT:
4230 Virtual Address of SRIO port 'n' memory region
4232 - CONFIG_SYS_SRIOn_MEM_PHYS:
4233 Physical Address of SRIO port 'n' memory region
4235 - CONFIG_SYS_SRIOn_MEM_SIZE:
4236 Size of SRIO port 'n' memory region
4238 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4239 Defined to tell the NAND controller that the NAND chip is using
4241 Not all NAND drivers use this symbol.
4242 Example of drivers that use it:
4243 - drivers/mtd/nand/ndfc.c
4244 - drivers/mtd/nand/mxc_nand.c
4246 - CONFIG_SYS_NDFC_EBC0_CFG
4247 Sets the EBC0_CFG register for the NDFC. If not defined
4248 a default value will be used.
4251 Get DDR timing information from an I2C EEPROM. Common
4252 with pluggable memory modules such as SODIMMs
4255 I2C address of the SPD EEPROM
4257 - CONFIG_SYS_SPD_BUS_NUM
4258 If SPD EEPROM is on an I2C bus other than the first
4259 one, specify here. Note that the value must resolve
4260 to something your driver can deal with.
4262 - CONFIG_SYS_DDR_RAW_TIMING
4263 Get DDR timing information from other than SPD. Common with
4264 soldered DDR chips onboard without SPD. DDR raw timing
4265 parameters are extracted from datasheet and hard-coded into
4266 header files or board specific files.
4268 - CONFIG_FSL_DDR_INTERACTIVE
4269 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4271 - CONFIG_SYS_83XX_DDR_USES_CS0
4272 Only for 83xx systems. If specified, then DDR should
4273 be configured using CS0 and CS1 instead of CS2 and CS3.
4275 - CONFIG_ETHER_ON_FEC[12]
4276 Define to enable FEC[12] on a 8xx series processor.
4278 - CONFIG_FEC[12]_PHY
4279 Define to the hardcoded PHY address which corresponds
4280 to the given FEC; i. e.
4281 #define CONFIG_FEC1_PHY 4
4282 means that the PHY with address 4 is connected to FEC1
4284 When set to -1, means to probe for first available.
4286 - CONFIG_FEC[12]_PHY_NORXERR
4287 The PHY does not have a RXERR line (RMII only).
4288 (so program the FEC to ignore it).
4291 Enable RMII mode for all FECs.
4292 Note that this is a global option, we can't
4293 have one FEC in standard MII mode and another in RMII mode.
4295 - CONFIG_CRC32_VERIFY
4296 Add a verify option to the crc32 command.
4299 => crc32 -v <address> <count> <crc32>
4301 Where address/count indicate a memory area
4302 and crc32 is the correct crc32 which the
4306 Add the "loopw" memory command. This only takes effect if
4307 the memory commands are activated globally (CONFIG_CMD_MEM).
4310 Add the "mdc" and "mwc" memory commands. These are cyclic
4315 This command will print 4 bytes (10,11,12,13) each 500 ms.
4317 => mwc.l 100 12345678 10
4318 This command will write 12345678 to address 100 all 10 ms.
4320 This only takes effect if the memory commands are activated
4321 globally (CONFIG_CMD_MEM).
4323 - CONFIG_SKIP_LOWLEVEL_INIT
4324 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4325 low level initializations (like setting up the memory
4326 controller) are omitted and/or U-Boot does not
4327 relocate itself into RAM.
4329 Normally this variable MUST NOT be defined. The only
4330 exception is when U-Boot is loaded (to RAM) by some
4331 other boot loader or by a debugger which performs
4332 these initializations itself.
4335 Modifies the behaviour of start.S when compiling a loader
4336 that is executed before the actual U-Boot. E.g. when
4337 compiling a NAND SPL.
4340 Modifies the behaviour of start.S when compiling a loader
4341 that is executed after the SPL and before the actual U-Boot.
4342 It is loaded by the SPL.
4344 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4345 Only for 85xx systems. If this variable is specified, the section
4346 .resetvec is not kept and the section .bootpg is placed in the
4347 previous 4k of the .text section.
4349 - CONFIG_ARCH_MAP_SYSMEM
4350 Generally U-Boot (and in particular the md command) uses
4351 effective address. It is therefore not necessary to regard
4352 U-Boot address as virtual addresses that need to be translated
4353 to physical addresses. However, sandbox requires this, since
4354 it maintains its own little RAM buffer which contains all
4355 addressable memory. This option causes some memory accesses
4356 to be mapped through map_sysmem() / unmap_sysmem().
4358 - CONFIG_USE_ARCH_MEMCPY
4359 CONFIG_USE_ARCH_MEMSET
4360 If these options are used a optimized version of memcpy/memset will
4361 be used if available. These functions may be faster under some
4362 conditions but may increase the binary size.
4364 - CONFIG_X86_RESET_VECTOR
4365 If defined, the x86 reset vector code is included. This is not
4366 needed when U-Boot is running from Coreboot.
4369 Defines the MPU clock speed (in MHz).
4371 NOTE : currently only supported on AM335x platforms.
4373 Freescale QE/FMAN Firmware Support:
4374 -----------------------------------
4376 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4377 loading of "firmware", which is encoded in the QE firmware binary format.
4378 This firmware often needs to be loaded during U-Boot booting, so macros
4379 are used to identify the storage device (NOR flash, SPI, etc) and the address
4382 - CONFIG_SYS_QE_FMAN_FW_ADDR
4383 The address in the storage device where the firmware is located. The
4384 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4387 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4388 The maximum possible size of the firmware. The firmware binary format
4389 has a field that specifies the actual size of the firmware, but it
4390 might not be possible to read any part of the firmware unless some
4391 local storage is allocated to hold the entire firmware first.
4393 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4394 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4395 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4396 virtual address in NOR flash.
4398 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4399 Specifies that QE/FMAN firmware is located in NAND flash.
4400 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4402 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4403 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4404 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4406 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4407 Specifies that QE/FMAN firmware is located on the primary SPI
4408 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4410 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4411 Specifies that QE/FMAN firmware is located in the remote (master)
4412 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4413 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4414 window->master inbound window->master LAW->the ucode address in
4415 master's memory space.
4417 Building the Software:
4418 ======================
4420 Building U-Boot has been tested in several native build environments
4421 and in many different cross environments. Of course we cannot support
4422 all possibly existing versions of cross development tools in all
4423 (potentially obsolete) versions. In case of tool chain problems we
4424 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4425 which is extensively used to build and test U-Boot.
4427 If you are not using a native environment, it is assumed that you
4428 have GNU cross compiling tools available in your path. In this case,
4429 you must set the environment variable CROSS_COMPILE in your shell.
4430 Note that no changes to the Makefile or any other source files are
4431 necessary. For example using the ELDK on a 4xx CPU, please enter:
4433 $ CROSS_COMPILE=ppc_4xx-
4434 $ export CROSS_COMPILE
4436 Note: If you wish to generate Windows versions of the utilities in
4437 the tools directory you can use the MinGW toolchain
4438 (http://www.mingw.org). Set your HOST tools to the MinGW
4439 toolchain and execute 'make tools'. For example:
4441 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4443 Binaries such as tools/mkimage.exe will be created which can
4444 be executed on computers running Windows.
4446 U-Boot is intended to be simple to build. After installing the
4447 sources you must configure U-Boot for one specific board type. This
4452 where "NAME_config" is the name of one of the existing configu-
4453 rations; see boards.cfg for supported names.
4455 Note: for some board special configuration names may exist; check if
4456 additional information is available from the board vendor; for
4457 instance, the TQM823L systems are available without (standard)
4458 or with LCD support. You can select such additional "features"
4459 when choosing the configuration, i. e.
4462 - will configure for a plain TQM823L, i. e. no LCD support
4464 make TQM823L_LCD_config
4465 - will configure for a TQM823L with U-Boot console on LCD
4470 Finally, type "make all", and you should get some working U-Boot
4471 images ready for download to / installation on your system:
4473 - "u-boot.bin" is a raw binary image
4474 - "u-boot" is an image in ELF binary format
4475 - "u-boot.srec" is in Motorola S-Record format
4477 By default the build is performed locally and the objects are saved
4478 in the source directory. One of the two methods can be used to change
4479 this behavior and build U-Boot to some external directory:
4481 1. Add O= to the make command line invocations:
4483 make O=/tmp/build distclean
4484 make O=/tmp/build NAME_config
4485 make O=/tmp/build all
4487 2. Set environment variable BUILD_DIR to point to the desired location:
4489 export BUILD_DIR=/tmp/build
4494 Note that the command line "O=" setting overrides the BUILD_DIR environment
4498 Please be aware that the Makefiles assume you are using GNU make, so
4499 for instance on NetBSD you might need to use "gmake" instead of
4503 If the system board that you have is not listed, then you will need
4504 to port U-Boot to your hardware platform. To do this, follow these
4507 1. Add a new configuration option for your board to the toplevel
4508 "boards.cfg" file, using the existing entries as examples.
4509 Follow the instructions there to keep the boards in order.
4510 2. Create a new directory to hold your board specific code. Add any
4511 files you need. In your board directory, you will need at least
4512 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4513 3. Create a new configuration file "include/configs/<board>.h" for
4515 3. If you're porting U-Boot to a new CPU, then also create a new
4516 directory to hold your CPU specific code. Add any files you need.
4517 4. Run "make <board>_config" with your new name.
4518 5. Type "make", and you should get a working "u-boot.srec" file
4519 to be installed on your target system.
4520 6. Debug and solve any problems that might arise.
4521 [Of course, this last step is much harder than it sounds.]
4524 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4525 ==============================================================
4527 If you have modified U-Boot sources (for instance added a new board
4528 or support for new devices, a new CPU, etc.) you are expected to
4529 provide feedback to the other developers. The feedback normally takes
4530 the form of a "patch", i. e. a context diff against a certain (latest
4531 official or latest in the git repository) version of U-Boot sources.
4533 But before you submit such a patch, please verify that your modifi-
4534 cation did not break existing code. At least make sure that *ALL* of
4535 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4536 just run the "MAKEALL" script, which will configure and build U-Boot
4537 for ALL supported system. Be warned, this will take a while. You can
4538 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4539 environment variable to the script, i. e. to use the ELDK cross tools
4542 CROSS_COMPILE=ppc_8xx- MAKEALL
4544 or to build on a native PowerPC system you can type
4546 CROSS_COMPILE=' ' MAKEALL
4548 When using the MAKEALL script, the default behaviour is to build
4549 U-Boot in the source directory. This location can be changed by
4550 setting the BUILD_DIR environment variable. Also, for each target
4551 built, the MAKEALL script saves two log files (<target>.ERR and
4552 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4553 location can be changed by setting the MAKEALL_LOGDIR environment
4554 variable. For example:
4556 export BUILD_DIR=/tmp/build
4557 export MAKEALL_LOGDIR=/tmp/log
4558 CROSS_COMPILE=ppc_8xx- MAKEALL
4560 With the above settings build objects are saved in the /tmp/build,
4561 log files are saved in the /tmp/log and the source tree remains clean
4562 during the whole build process.
4565 See also "U-Boot Porting Guide" below.
4568 Monitor Commands - Overview:
4569 ============================
4571 go - start application at address 'addr'
4572 run - run commands in an environment variable
4573 bootm - boot application image from memory
4574 bootp - boot image via network using BootP/TFTP protocol
4575 bootz - boot zImage from memory
4576 tftpboot- boot image via network using TFTP protocol
4577 and env variables "ipaddr" and "serverip"
4578 (and eventually "gatewayip")
4579 tftpput - upload a file via network using TFTP protocol
4580 rarpboot- boot image via network using RARP/TFTP protocol
4581 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4582 loads - load S-Record file over serial line
4583 loadb - load binary file over serial line (kermit mode)
4585 mm - memory modify (auto-incrementing)
4586 nm - memory modify (constant address)
4587 mw - memory write (fill)
4589 cmp - memory compare
4590 crc32 - checksum calculation
4591 i2c - I2C sub-system
4592 sspi - SPI utility commands
4593 base - print or set address offset
4594 printenv- print environment variables
4595 setenv - set environment variables
4596 saveenv - save environment variables to persistent storage
4597 protect - enable or disable FLASH write protection
4598 erase - erase FLASH memory
4599 flinfo - print FLASH memory information
4600 nand - NAND memory operations (see doc/README.nand)
4601 bdinfo - print Board Info structure
4602 iminfo - print header information for application image
4603 coninfo - print console devices and informations
4604 ide - IDE sub-system
4605 loop - infinite loop on address range
4606 loopw - infinite write loop on address range
4607 mtest - simple RAM test
4608 icache - enable or disable instruction cache
4609 dcache - enable or disable data cache
4610 reset - Perform RESET of the CPU
4611 echo - echo args to console
4612 version - print monitor version
4613 help - print online help
4614 ? - alias for 'help'
4617 Monitor Commands - Detailed Description:
4618 ========================================
4622 For now: just type "help <command>".
4625 Environment Variables:
4626 ======================
4628 U-Boot supports user configuration using Environment Variables which
4629 can be made persistent by saving to Flash memory.
4631 Environment Variables are set using "setenv", printed using
4632 "printenv", and saved to Flash using "saveenv". Using "setenv"
4633 without a value can be used to delete a variable from the
4634 environment. As long as you don't save the environment you are
4635 working with an in-memory copy. In case the Flash area containing the
4636 environment is erased by accident, a default environment is provided.
4638 Some configuration options can be set using Environment Variables.
4640 List of environment variables (most likely not complete):
4642 baudrate - see CONFIG_BAUDRATE
4644 bootdelay - see CONFIG_BOOTDELAY
4646 bootcmd - see CONFIG_BOOTCOMMAND
4648 bootargs - Boot arguments when booting an RTOS image
4650 bootfile - Name of the image to load with TFTP
4652 bootm_low - Memory range available for image processing in the bootm
4653 command can be restricted. This variable is given as
4654 a hexadecimal number and defines lowest address allowed
4655 for use by the bootm command. See also "bootm_size"
4656 environment variable. Address defined by "bootm_low" is
4657 also the base of the initial memory mapping for the Linux
4658 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4661 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4662 This variable is given as a hexadecimal number and it
4663 defines the size of the memory region starting at base
4664 address bootm_low that is accessible by the Linux kernel
4665 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4666 as the default value if it is defined, and bootm_size is
4669 bootm_size - Memory range available for image processing in the bootm
4670 command can be restricted. This variable is given as
4671 a hexadecimal number and defines the size of the region
4672 allowed for use by the bootm command. See also "bootm_low"
4673 environment variable.
4675 updatefile - Location of the software update file on a TFTP server, used
4676 by the automatic software update feature. Please refer to
4677 documentation in doc/README.update for more details.
4679 autoload - if set to "no" (any string beginning with 'n'),
4680 "bootp" will just load perform a lookup of the
4681 configuration from the BOOTP server, but not try to
4682 load any image using TFTP
4684 autostart - if set to "yes", an image loaded using the "bootp",
4685 "rarpboot", "tftpboot" or "diskboot" commands will
4686 be automatically started (by internally calling
4689 If set to "no", a standalone image passed to the
4690 "bootm" command will be copied to the load address
4691 (and eventually uncompressed), but NOT be started.
4692 This can be used to load and uncompress arbitrary
4695 fdt_high - if set this restricts the maximum address that the
4696 flattened device tree will be copied into upon boot.
4697 For example, if you have a system with 1 GB memory
4698 at physical address 0x10000000, while Linux kernel
4699 only recognizes the first 704 MB as low memory, you
4700 may need to set fdt_high as 0x3C000000 to have the
4701 device tree blob be copied to the maximum address
4702 of the 704 MB low memory, so that Linux kernel can
4703 access it during the boot procedure.
4705 If this is set to the special value 0xFFFFFFFF then
4706 the fdt will not be copied at all on boot. For this
4707 to work it must reside in writable memory, have
4708 sufficient padding on the end of it for u-boot to
4709 add the information it needs into it, and the memory
4710 must be accessible by the kernel.
4712 fdtcontroladdr- if set this is the address of the control flattened
4713 device tree used by U-Boot when CONFIG_OF_CONTROL is
4716 i2cfast - (PPC405GP|PPC405EP only)
4717 if set to 'y' configures Linux I2C driver for fast
4718 mode (400kHZ). This environment variable is used in
4719 initialization code. So, for changes to be effective
4720 it must be saved and board must be reset.
4722 initrd_high - restrict positioning of initrd images:
4723 If this variable is not set, initrd images will be
4724 copied to the highest possible address in RAM; this
4725 is usually what you want since it allows for
4726 maximum initrd size. If for some reason you want to
4727 make sure that the initrd image is loaded below the
4728 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4729 variable to a value of "no" or "off" or "0".
4730 Alternatively, you can set it to a maximum upper
4731 address to use (U-Boot will still check that it
4732 does not overwrite the U-Boot stack and data).
4734 For instance, when you have a system with 16 MB
4735 RAM, and want to reserve 4 MB from use by Linux,
4736 you can do this by adding "mem=12M" to the value of
4737 the "bootargs" variable. However, now you must make
4738 sure that the initrd image is placed in the first
4739 12 MB as well - this can be done with
4741 setenv initrd_high 00c00000
4743 If you set initrd_high to 0xFFFFFFFF, this is an
4744 indication to U-Boot that all addresses are legal
4745 for the Linux kernel, including addresses in flash
4746 memory. In this case U-Boot will NOT COPY the
4747 ramdisk at all. This may be useful to reduce the
4748 boot time on your system, but requires that this
4749 feature is supported by your Linux kernel.
4751 ipaddr - IP address; needed for tftpboot command
4753 loadaddr - Default load address for commands like "bootp",
4754 "rarpboot", "tftpboot", "loadb" or "diskboot"
4756 loads_echo - see CONFIG_LOADS_ECHO
4758 serverip - TFTP server IP address; needed for tftpboot command
4760 bootretry - see CONFIG_BOOT_RETRY_TIME
4762 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4764 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4766 ethprime - controls which interface is used first.
4768 ethact - controls which interface is currently active.
4769 For example you can do the following
4771 => setenv ethact FEC
4772 => ping 192.168.0.1 # traffic sent on FEC
4773 => setenv ethact SCC
4774 => ping 10.0.0.1 # traffic sent on SCC
4776 ethrotate - When set to "no" U-Boot does not go through all
4777 available network interfaces.
4778 It just stays at the currently selected interface.
4780 netretry - When set to "no" each network operation will
4781 either succeed or fail without retrying.
4782 When set to "once" the network operation will
4783 fail when all the available network interfaces
4784 are tried once without success.
4785 Useful on scripts which control the retry operation
4788 npe_ucode - set load address for the NPE microcode
4790 silent_linux - If set then linux will be told to boot silently, by
4791 changing the console to be empty. If "yes" it will be
4792 made silent. If "no" it will not be made silent. If
4793 unset, then it will be made silent if the U-Boot console
4796 tftpsrcport - If this is set, the value is used for TFTP's
4799 tftpdstport - If this is set, the value is used for TFTP's UDP
4800 destination port instead of the Well Know Port 69.
4802 tftpblocksize - Block size to use for TFTP transfers; if not set,
4803 we use the TFTP server's default block size
4805 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4806 seconds, minimum value is 1000 = 1 second). Defines
4807 when a packet is considered to be lost so it has to
4808 be retransmitted. The default is 5000 = 5 seconds.
4809 Lowering this value may make downloads succeed
4810 faster in networks with high packet loss rates or
4811 with unreliable TFTP servers.
4813 vlan - When set to a value < 4095 the traffic over
4814 Ethernet is encapsulated/received over 802.1q
4817 The following image location variables contain the location of images
4818 used in booting. The "Image" column gives the role of the image and is
4819 not an environment variable name. The other columns are environment
4820 variable names. "File Name" gives the name of the file on a TFTP
4821 server, "RAM Address" gives the location in RAM the image will be
4822 loaded to, and "Flash Location" gives the image's address in NOR
4823 flash or offset in NAND flash.
4825 *Note* - these variables don't have to be defined for all boards, some
4826 boards currenlty use other variables for these purposes, and some
4827 boards use these variables for other purposes.
4829 Image File Name RAM Address Flash Location
4830 ----- --------- ----------- --------------
4831 u-boot u-boot u-boot_addr_r u-boot_addr
4832 Linux kernel bootfile kernel_addr_r kernel_addr
4833 device tree blob fdtfile fdt_addr_r fdt_addr
4834 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4836 The following environment variables may be used and automatically
4837 updated by the network boot commands ("bootp" and "rarpboot"),
4838 depending the information provided by your boot server:
4840 bootfile - see above
4841 dnsip - IP address of your Domain Name Server
4842 dnsip2 - IP address of your secondary Domain Name Server
4843 gatewayip - IP address of the Gateway (Router) to use
4844 hostname - Target hostname
4846 netmask - Subnet Mask
4847 rootpath - Pathname of the root filesystem on the NFS server
4848 serverip - see above
4851 There are two special Environment Variables:
4853 serial# - contains hardware identification information such
4854 as type string and/or serial number
4855 ethaddr - Ethernet address
4857 These variables can be set only once (usually during manufacturing of
4858 the board). U-Boot refuses to delete or overwrite these variables
4859 once they have been set once.
4862 Further special Environment Variables:
4864 ver - Contains the U-Boot version string as printed
4865 with the "version" command. This variable is
4866 readonly (see CONFIG_VERSION_VARIABLE).
4869 Please note that changes to some configuration parameters may take
4870 only effect after the next boot (yes, that's just like Windoze :-).
4873 Callback functions for environment variables:
4874 ---------------------------------------------
4876 For some environment variables, the behavior of u-boot needs to change
4877 when their values are changed. This functionailty allows functions to
4878 be associated with arbitrary variables. On creation, overwrite, or
4879 deletion, the callback will provide the opportunity for some side
4880 effect to happen or for the change to be rejected.
4882 The callbacks are named and associated with a function using the
4883 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4885 These callbacks are associated with variables in one of two ways. The
4886 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4887 in the board configuration to a string that defines a list of
4888 associations. The list must be in the following format:
4890 entry = variable_name[:callback_name]
4893 If the callback name is not specified, then the callback is deleted.
4894 Spaces are also allowed anywhere in the list.
4896 Callbacks can also be associated by defining the ".callbacks" variable
4897 with the same list format above. Any association in ".callbacks" will
4898 override any association in the static list. You can define
4899 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
4900 ".callbacks" envirnoment variable in the default or embedded environment.
4903 Command Line Parsing:
4904 =====================
4906 There are two different command line parsers available with U-Boot:
4907 the old "simple" one, and the much more powerful "hush" shell:
4909 Old, simple command line parser:
4910 --------------------------------
4912 - supports environment variables (through setenv / saveenv commands)
4913 - several commands on one line, separated by ';'
4914 - variable substitution using "... ${name} ..." syntax
4915 - special characters ('$', ';') can be escaped by prefixing with '\',
4917 setenv bootcmd bootm \${address}
4918 - You can also escape text by enclosing in single apostrophes, for example:
4919 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4924 - similar to Bourne shell, with control structures like
4925 if...then...else...fi, for...do...done; while...do...done,
4926 until...do...done, ...
4927 - supports environment ("global") variables (through setenv / saveenv
4928 commands) and local shell variables (through standard shell syntax
4929 "name=value"); only environment variables can be used with "run"
4935 (1) If a command line (or an environment variable executed by a "run"
4936 command) contains several commands separated by semicolon, and
4937 one of these commands fails, then the remaining commands will be
4940 (2) If you execute several variables with one call to run (i. e.
4941 calling run with a list of variables as arguments), any failing
4942 command will cause "run" to terminate, i. e. the remaining
4943 variables are not executed.
4945 Note for Redundant Ethernet Interfaces:
4946 =======================================
4948 Some boards come with redundant Ethernet interfaces; U-Boot supports
4949 such configurations and is capable of automatic selection of a
4950 "working" interface when needed. MAC assignment works as follows:
4952 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4953 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4954 "eth1addr" (=>eth1), "eth2addr", ...
4956 If the network interface stores some valid MAC address (for instance
4957 in SROM), this is used as default address if there is NO correspon-
4958 ding setting in the environment; if the corresponding environment
4959 variable is set, this overrides the settings in the card; that means:
4961 o If the SROM has a valid MAC address, and there is no address in the
4962 environment, the SROM's address is used.
4964 o If there is no valid address in the SROM, and a definition in the
4965 environment exists, then the value from the environment variable is
4968 o If both the SROM and the environment contain a MAC address, and
4969 both addresses are the same, this MAC address is used.
4971 o If both the SROM and the environment contain a MAC address, and the
4972 addresses differ, the value from the environment is used and a
4975 o If neither SROM nor the environment contain a MAC address, an error
4978 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4979 will be programmed into hardware as part of the initialization process. This
4980 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4981 The naming convention is as follows:
4982 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4987 U-Boot is capable of booting (and performing other auxiliary operations on)
4988 images in two formats:
4990 New uImage format (FIT)
4991 -----------------------
4993 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4994 to Flattened Device Tree). It allows the use of images with multiple
4995 components (several kernels, ramdisks, etc.), with contents protected by
4996 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5002 Old image format is based on binary files which can be basically anything,
5003 preceded by a special header; see the definitions in include/image.h for
5004 details; basically, the header defines the following image properties:
5006 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5007 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5008 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5009 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5011 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5012 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5013 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5014 * Compression Type (uncompressed, gzip, bzip2)
5020 The header is marked by a special Magic Number, and both the header
5021 and the data portions of the image are secured against corruption by
5028 Although U-Boot should support any OS or standalone application
5029 easily, the main focus has always been on Linux during the design of
5032 U-Boot includes many features that so far have been part of some
5033 special "boot loader" code within the Linux kernel. Also, any
5034 "initrd" images to be used are no longer part of one big Linux image;
5035 instead, kernel and "initrd" are separate images. This implementation
5036 serves several purposes:
5038 - the same features can be used for other OS or standalone
5039 applications (for instance: using compressed images to reduce the
5040 Flash memory footprint)
5042 - it becomes much easier to port new Linux kernel versions because
5043 lots of low-level, hardware dependent stuff are done by U-Boot
5045 - the same Linux kernel image can now be used with different "initrd"
5046 images; of course this also means that different kernel images can
5047 be run with the same "initrd". This makes testing easier (you don't
5048 have to build a new "zImage.initrd" Linux image when you just
5049 change a file in your "initrd"). Also, a field-upgrade of the
5050 software is easier now.
5056 Porting Linux to U-Boot based systems:
5057 ---------------------------------------
5059 U-Boot cannot save you from doing all the necessary modifications to
5060 configure the Linux device drivers for use with your target hardware
5061 (no, we don't intend to provide a full virtual machine interface to
5064 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5066 Just make sure your machine specific header file (for instance
5067 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5068 Information structure as we define in include/asm-<arch>/u-boot.h,
5069 and make sure that your definition of IMAP_ADDR uses the same value
5070 as your U-Boot configuration in CONFIG_SYS_IMMR.
5073 Configuring the Linux kernel:
5074 -----------------------------
5076 No specific requirements for U-Boot. Make sure you have some root
5077 device (initial ramdisk, NFS) for your target system.
5080 Building a Linux Image:
5081 -----------------------
5083 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5084 not used. If you use recent kernel source, a new build target
5085 "uImage" will exist which automatically builds an image usable by
5086 U-Boot. Most older kernels also have support for a "pImage" target,
5087 which was introduced for our predecessor project PPCBoot and uses a
5088 100% compatible format.
5097 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5098 encapsulate a compressed Linux kernel image with header information,
5099 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5101 * build a standard "vmlinux" kernel image (in ELF binary format):
5103 * convert the kernel into a raw binary image:
5105 ${CROSS_COMPILE}-objcopy -O binary \
5106 -R .note -R .comment \
5107 -S vmlinux linux.bin
5109 * compress the binary image:
5113 * package compressed binary image for U-Boot:
5115 mkimage -A ppc -O linux -T kernel -C gzip \
5116 -a 0 -e 0 -n "Linux Kernel Image" \
5117 -d linux.bin.gz uImage
5120 The "mkimage" tool can also be used to create ramdisk images for use
5121 with U-Boot, either separated from the Linux kernel image, or
5122 combined into one file. "mkimage" encapsulates the images with a 64
5123 byte header containing information about target architecture,
5124 operating system, image type, compression method, entry points, time
5125 stamp, CRC32 checksums, etc.
5127 "mkimage" can be called in two ways: to verify existing images and
5128 print the header information, or to build new images.
5130 In the first form (with "-l" option) mkimage lists the information
5131 contained in the header of an existing U-Boot image; this includes
5132 checksum verification:
5134 tools/mkimage -l image
5135 -l ==> list image header information
5137 The second form (with "-d" option) is used to build a U-Boot image
5138 from a "data file" which is used as image payload:
5140 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5141 -n name -d data_file image
5142 -A ==> set architecture to 'arch'
5143 -O ==> set operating system to 'os'
5144 -T ==> set image type to 'type'
5145 -C ==> set compression type 'comp'
5146 -a ==> set load address to 'addr' (hex)
5147 -e ==> set entry point to 'ep' (hex)
5148 -n ==> set image name to 'name'
5149 -d ==> use image data from 'datafile'
5151 Right now, all Linux kernels for PowerPC systems use the same load
5152 address (0x00000000), but the entry point address depends on the
5155 - 2.2.x kernels have the entry point at 0x0000000C,
5156 - 2.3.x and later kernels have the entry point at 0x00000000.
5158 So a typical call to build a U-Boot image would read:
5160 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5161 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5162 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5163 > examples/uImage.TQM850L
5164 Image Name: 2.4.4 kernel for TQM850L
5165 Created: Wed Jul 19 02:34:59 2000
5166 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5167 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5168 Load Address: 0x00000000
5169 Entry Point: 0x00000000
5171 To verify the contents of the image (or check for corruption):
5173 -> tools/mkimage -l examples/uImage.TQM850L
5174 Image Name: 2.4.4 kernel for TQM850L
5175 Created: Wed Jul 19 02:34:59 2000
5176 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5177 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5178 Load Address: 0x00000000
5179 Entry Point: 0x00000000
5181 NOTE: for embedded systems where boot time is critical you can trade
5182 speed for memory and install an UNCOMPRESSED image instead: this
5183 needs more space in Flash, but boots much faster since it does not
5184 need to be uncompressed:
5186 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5187 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5188 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5189 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5190 > examples/uImage.TQM850L-uncompressed
5191 Image Name: 2.4.4 kernel for TQM850L
5192 Created: Wed Jul 19 02:34:59 2000
5193 Image Type: PowerPC Linux Kernel Image (uncompressed)
5194 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5195 Load Address: 0x00000000
5196 Entry Point: 0x00000000
5199 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5200 when your kernel is intended to use an initial ramdisk:
5202 -> tools/mkimage -n 'Simple Ramdisk Image' \
5203 > -A ppc -O linux -T ramdisk -C gzip \
5204 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5205 Image Name: Simple Ramdisk Image
5206 Created: Wed Jan 12 14:01:50 2000
5207 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5208 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5209 Load Address: 0x00000000
5210 Entry Point: 0x00000000
5213 Installing a Linux Image:
5214 -------------------------
5216 To downloading a U-Boot image over the serial (console) interface,
5217 you must convert the image to S-Record format:
5219 objcopy -I binary -O srec examples/image examples/image.srec
5221 The 'objcopy' does not understand the information in the U-Boot
5222 image header, so the resulting S-Record file will be relative to
5223 address 0x00000000. To load it to a given address, you need to
5224 specify the target address as 'offset' parameter with the 'loads'
5227 Example: install the image to address 0x40100000 (which on the
5228 TQM8xxL is in the first Flash bank):
5230 => erase 40100000 401FFFFF
5236 ## Ready for S-Record download ...
5237 ~>examples/image.srec
5238 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5240 15989 15990 15991 15992
5241 [file transfer complete]
5243 ## Start Addr = 0x00000000
5246 You can check the success of the download using the 'iminfo' command;
5247 this includes a checksum verification so you can be sure no data
5248 corruption happened:
5252 ## Checking Image at 40100000 ...
5253 Image Name: 2.2.13 for initrd on TQM850L
5254 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5255 Data Size: 335725 Bytes = 327 kB = 0 MB
5256 Load Address: 00000000
5257 Entry Point: 0000000c
5258 Verifying Checksum ... OK
5264 The "bootm" command is used to boot an application that is stored in
5265 memory (RAM or Flash). In case of a Linux kernel image, the contents
5266 of the "bootargs" environment variable is passed to the kernel as
5267 parameters. You can check and modify this variable using the
5268 "printenv" and "setenv" commands:
5271 => printenv bootargs
5272 bootargs=root=/dev/ram
5274 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5276 => printenv bootargs
5277 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5280 ## Booting Linux kernel at 40020000 ...
5281 Image Name: 2.2.13 for NFS on TQM850L
5282 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5283 Data Size: 381681 Bytes = 372 kB = 0 MB
5284 Load Address: 00000000
5285 Entry Point: 0000000c
5286 Verifying Checksum ... OK
5287 Uncompressing Kernel Image ... OK
5288 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
5289 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5290 time_init: decrementer frequency = 187500000/60
5291 Calibrating delay loop... 49.77 BogoMIPS
5292 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5295 If you want to boot a Linux kernel with initial RAM disk, you pass
5296 the memory addresses of both the kernel and the initrd image (PPBCOOT
5297 format!) to the "bootm" command:
5299 => imi 40100000 40200000
5301 ## Checking Image at 40100000 ...
5302 Image Name: 2.2.13 for initrd on TQM850L
5303 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5304 Data Size: 335725 Bytes = 327 kB = 0 MB
5305 Load Address: 00000000
5306 Entry Point: 0000000c
5307 Verifying Checksum ... OK
5309 ## Checking Image at 40200000 ...
5310 Image Name: Simple Ramdisk Image
5311 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5312 Data Size: 566530 Bytes = 553 kB = 0 MB
5313 Load Address: 00000000
5314 Entry Point: 00000000
5315 Verifying Checksum ... OK
5317 => bootm 40100000 40200000
5318 ## Booting Linux kernel at 40100000 ...
5319 Image Name: 2.2.13 for initrd on TQM850L
5320 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5321 Data Size: 335725 Bytes = 327 kB = 0 MB
5322 Load Address: 00000000
5323 Entry Point: 0000000c
5324 Verifying Checksum ... OK
5325 Uncompressing Kernel Image ... OK
5326 ## Loading RAMDisk Image at 40200000 ...
5327 Image Name: Simple Ramdisk Image
5328 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5329 Data Size: 566530 Bytes = 553 kB = 0 MB
5330 Load Address: 00000000
5331 Entry Point: 00000000
5332 Verifying Checksum ... OK
5333 Loading Ramdisk ... OK
5334 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
5335 Boot arguments: root=/dev/ram
5336 time_init: decrementer frequency = 187500000/60
5337 Calibrating delay loop... 49.77 BogoMIPS
5339 RAMDISK: Compressed image found at block 0
5340 VFS: Mounted root (ext2 filesystem).
5344 Boot Linux and pass a flat device tree:
5347 First, U-Boot must be compiled with the appropriate defines. See the section
5348 titled "Linux Kernel Interface" above for a more in depth explanation. The
5349 following is an example of how to start a kernel and pass an updated
5355 oft=oftrees/mpc8540ads.dtb
5356 => tftp $oftaddr $oft
5357 Speed: 1000, full duplex
5359 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5360 Filename 'oftrees/mpc8540ads.dtb'.
5361 Load address: 0x300000
5364 Bytes transferred = 4106 (100a hex)
5365 => tftp $loadaddr $bootfile
5366 Speed: 1000, full duplex
5368 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5370 Load address: 0x200000
5371 Loading:############
5373 Bytes transferred = 1029407 (fb51f hex)
5378 => bootm $loadaddr - $oftaddr
5379 ## Booting image at 00200000 ...
5380 Image Name: Linux-2.6.17-dirty
5381 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5382 Data Size: 1029343 Bytes = 1005.2 kB
5383 Load Address: 00000000
5384 Entry Point: 00000000
5385 Verifying Checksum ... OK
5386 Uncompressing Kernel Image ... OK
5387 Booting using flat device tree at 0x300000
5388 Using MPC85xx ADS machine description
5389 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5393 More About U-Boot Image Types:
5394 ------------------------------
5396 U-Boot supports the following image types:
5398 "Standalone Programs" are directly runnable in the environment
5399 provided by U-Boot; it is expected that (if they behave
5400 well) you can continue to work in U-Boot after return from
5401 the Standalone Program.
5402 "OS Kernel Images" are usually images of some Embedded OS which
5403 will take over control completely. Usually these programs
5404 will install their own set of exception handlers, device
5405 drivers, set up the MMU, etc. - this means, that you cannot
5406 expect to re-enter U-Boot except by resetting the CPU.
5407 "RAMDisk Images" are more or less just data blocks, and their
5408 parameters (address, size) are passed to an OS kernel that is
5410 "Multi-File Images" contain several images, typically an OS
5411 (Linux) kernel image and one or more data images like
5412 RAMDisks. This construct is useful for instance when you want
5413 to boot over the network using BOOTP etc., where the boot
5414 server provides just a single image file, but you want to get
5415 for instance an OS kernel and a RAMDisk image.
5417 "Multi-File Images" start with a list of image sizes, each
5418 image size (in bytes) specified by an "uint32_t" in network
5419 byte order. This list is terminated by an "(uint32_t)0".
5420 Immediately after the terminating 0 follow the images, one by
5421 one, all aligned on "uint32_t" boundaries (size rounded up to
5422 a multiple of 4 bytes).
5424 "Firmware Images" are binary images containing firmware (like
5425 U-Boot or FPGA images) which usually will be programmed to
5428 "Script files" are command sequences that will be executed by
5429 U-Boot's command interpreter; this feature is especially
5430 useful when you configure U-Boot to use a real shell (hush)
5431 as command interpreter.
5433 Booting the Linux zImage:
5434 -------------------------
5436 On some platforms, it's possible to boot Linux zImage. This is done
5437 using the "bootz" command. The syntax of "bootz" command is the same
5438 as the syntax of "bootm" command.
5440 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5441 kernel with raw initrd images. The syntax is slightly different, the
5442 address of the initrd must be augmented by it's size, in the following
5443 format: "<initrd addres>:<initrd size>".
5449 One of the features of U-Boot is that you can dynamically load and
5450 run "standalone" applications, which can use some resources of
5451 U-Boot like console I/O functions or interrupt services.
5453 Two simple examples are included with the sources:
5458 'examples/hello_world.c' contains a small "Hello World" Demo
5459 application; it is automatically compiled when you build U-Boot.
5460 It's configured to run at address 0x00040004, so you can play with it
5464 ## Ready for S-Record download ...
5465 ~>examples/hello_world.srec
5466 1 2 3 4 5 6 7 8 9 10 11 ...
5467 [file transfer complete]
5469 ## Start Addr = 0x00040004
5471 => go 40004 Hello World! This is a test.
5472 ## Starting application at 0x00040004 ...
5483 Hit any key to exit ...
5485 ## Application terminated, rc = 0x0
5487 Another example, which demonstrates how to register a CPM interrupt
5488 handler with the U-Boot code, can be found in 'examples/timer.c'.
5489 Here, a CPM timer is set up to generate an interrupt every second.
5490 The interrupt service routine is trivial, just printing a '.'
5491 character, but this is just a demo program. The application can be
5492 controlled by the following keys:
5494 ? - print current values og the CPM Timer registers
5495 b - enable interrupts and start timer
5496 e - stop timer and disable interrupts
5497 q - quit application
5500 ## Ready for S-Record download ...
5501 ~>examples/timer.srec
5502 1 2 3 4 5 6 7 8 9 10 11 ...
5503 [file transfer complete]
5505 ## Start Addr = 0x00040004
5508 ## Starting application at 0x00040004 ...
5511 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5514 [q, b, e, ?] Set interval 1000000 us
5517 [q, b, e, ?] ........
5518 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5521 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5524 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5527 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5529 [q, b, e, ?] ...Stopping timer
5531 [q, b, e, ?] ## Application terminated, rc = 0x0
5537 Over time, many people have reported problems when trying to use the
5538 "minicom" terminal emulation program for serial download. I (wd)
5539 consider minicom to be broken, and recommend not to use it. Under
5540 Unix, I recommend to use C-Kermit for general purpose use (and
5541 especially for kermit binary protocol download ("loadb" command), and
5542 use "cu" for S-Record download ("loads" command). See
5543 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5544 for help with kermit.
5547 Nevertheless, if you absolutely want to use it try adding this
5548 configuration to your "File transfer protocols" section:
5550 Name Program Name U/D FullScr IO-Red. Multi
5551 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5552 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5558 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5559 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5561 Building requires a cross environment; it is known to work on
5562 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5563 need gmake since the Makefiles are not compatible with BSD make).
5564 Note that the cross-powerpc package does not install include files;
5565 attempting to build U-Boot will fail because <machine/ansi.h> is
5566 missing. This file has to be installed and patched manually:
5568 # cd /usr/pkg/cross/powerpc-netbsd/include
5570 # ln -s powerpc machine
5571 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5572 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5574 Native builds *don't* work due to incompatibilities between native
5575 and U-Boot include files.
5577 Booting assumes that (the first part of) the image booted is a
5578 stage-2 loader which in turn loads and then invokes the kernel
5579 proper. Loader sources will eventually appear in the NetBSD source
5580 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5581 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5584 Implementation Internals:
5585 =========================
5587 The following is not intended to be a complete description of every
5588 implementation detail. However, it should help to understand the
5589 inner workings of U-Boot and make it easier to port it to custom
5593 Initial Stack, Global Data:
5594 ---------------------------
5596 The implementation of U-Boot is complicated by the fact that U-Boot
5597 starts running out of ROM (flash memory), usually without access to
5598 system RAM (because the memory controller is not initialized yet).
5599 This means that we don't have writable Data or BSS segments, and BSS
5600 is not initialized as zero. To be able to get a C environment working
5601 at all, we have to allocate at least a minimal stack. Implementation
5602 options for this are defined and restricted by the CPU used: Some CPU
5603 models provide on-chip memory (like the IMMR area on MPC8xx and
5604 MPC826x processors), on others (parts of) the data cache can be
5605 locked as (mis-) used as memory, etc.
5607 Chris Hallinan posted a good summary of these issues to the
5608 U-Boot mailing list:
5610 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5611 From: "Chris Hallinan" <clh@net1plus.com>
5612 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5615 Correct me if I'm wrong, folks, but the way I understand it
5616 is this: Using DCACHE as initial RAM for Stack, etc, does not
5617 require any physical RAM backing up the cache. The cleverness
5618 is that the cache is being used as a temporary supply of
5619 necessary storage before the SDRAM controller is setup. It's
5620 beyond the scope of this list to explain the details, but you
5621 can see how this works by studying the cache architecture and
5622 operation in the architecture and processor-specific manuals.
5624 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5625 is another option for the system designer to use as an
5626 initial stack/RAM area prior to SDRAM being available. Either
5627 option should work for you. Using CS 4 should be fine if your
5628 board designers haven't used it for something that would
5629 cause you grief during the initial boot! It is frequently not
5632 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5633 with your processor/board/system design. The default value
5634 you will find in any recent u-boot distribution in
5635 walnut.h should work for you. I'd set it to a value larger
5636 than your SDRAM module. If you have a 64MB SDRAM module, set
5637 it above 400_0000. Just make sure your board has no resources
5638 that are supposed to respond to that address! That code in
5639 start.S has been around a while and should work as is when
5640 you get the config right.
5645 It is essential to remember this, since it has some impact on the C
5646 code for the initialization procedures:
5648 * Initialized global data (data segment) is read-only. Do not attempt
5651 * Do not use any uninitialized global data (or implicitely initialized
5652 as zero data - BSS segment) at all - this is undefined, initiali-
5653 zation is performed later (when relocating to RAM).
5655 * Stack space is very limited. Avoid big data buffers or things like
5658 Having only the stack as writable memory limits means we cannot use
5659 normal global data to share information beween the code. But it
5660 turned out that the implementation of U-Boot can be greatly
5661 simplified by making a global data structure (gd_t) available to all
5662 functions. We could pass a pointer to this data as argument to _all_
5663 functions, but this would bloat the code. Instead we use a feature of
5664 the GCC compiler (Global Register Variables) to share the data: we
5665 place a pointer (gd) to the global data into a register which we
5666 reserve for this purpose.
5668 When choosing a register for such a purpose we are restricted by the
5669 relevant (E)ABI specifications for the current architecture, and by
5670 GCC's implementation.
5672 For PowerPC, the following registers have specific use:
5674 R2: reserved for system use
5675 R3-R4: parameter passing and return values
5676 R5-R10: parameter passing
5677 R13: small data area pointer
5681 (U-Boot also uses R12 as internal GOT pointer. r12
5682 is a volatile register so r12 needs to be reset when
5683 going back and forth between asm and C)
5685 ==> U-Boot will use R2 to hold a pointer to the global data
5687 Note: on PPC, we could use a static initializer (since the
5688 address of the global data structure is known at compile time),
5689 but it turned out that reserving a register results in somewhat
5690 smaller code - although the code savings are not that big (on
5691 average for all boards 752 bytes for the whole U-Boot image,
5692 624 text + 127 data).
5694 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5695 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5697 ==> U-Boot will use P3 to hold a pointer to the global data
5699 On ARM, the following registers are used:
5701 R0: function argument word/integer result
5702 R1-R3: function argument word
5703 R9: platform specific
5704 R10: stack limit (used only if stack checking is enabled)
5705 R11: argument (frame) pointer
5706 R12: temporary workspace
5709 R15: program counter
5711 ==> U-Boot will use R9 to hold a pointer to the global data
5713 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5715 On Nios II, the ABI is documented here:
5716 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5718 ==> U-Boot will use gp to hold a pointer to the global data
5720 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5721 to access small data sections, so gp is free.
5723 On NDS32, the following registers are used:
5725 R0-R1: argument/return
5727 R15: temporary register for assembler
5728 R16: trampoline register
5729 R28: frame pointer (FP)
5730 R29: global pointer (GP)
5731 R30: link register (LP)
5732 R31: stack pointer (SP)
5733 PC: program counter (PC)
5735 ==> U-Boot will use R10 to hold a pointer to the global data
5737 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5738 or current versions of GCC may "optimize" the code too much.
5743 U-Boot runs in system state and uses physical addresses, i.e. the
5744 MMU is not used either for address mapping nor for memory protection.
5746 The available memory is mapped to fixed addresses using the memory
5747 controller. In this process, a contiguous block is formed for each
5748 memory type (Flash, SDRAM, SRAM), even when it consists of several
5749 physical memory banks.
5751 U-Boot is installed in the first 128 kB of the first Flash bank (on
5752 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5753 booting and sizing and initializing DRAM, the code relocates itself
5754 to the upper end of DRAM. Immediately below the U-Boot code some
5755 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5756 configuration setting]. Below that, a structure with global Board
5757 Info data is placed, followed by the stack (growing downward).
5759 Additionally, some exception handler code is copied to the low 8 kB
5760 of DRAM (0x00000000 ... 0x00001FFF).
5762 So a typical memory configuration with 16 MB of DRAM could look like
5765 0x0000 0000 Exception Vector code
5768 0x0000 2000 Free for Application Use
5774 0x00FB FF20 Monitor Stack (Growing downward)
5775 0x00FB FFAC Board Info Data and permanent copy of global data
5776 0x00FC 0000 Malloc Arena
5779 0x00FE 0000 RAM Copy of Monitor Code
5780 ... eventually: LCD or video framebuffer
5781 ... eventually: pRAM (Protected RAM - unchanged by reset)
5782 0x00FF FFFF [End of RAM]
5785 System Initialization:
5786 ----------------------
5788 In the reset configuration, U-Boot starts at the reset entry point
5789 (on most PowerPC systems at address 0x00000100). Because of the reset
5790 configuration for CS0# this is a mirror of the onboard Flash memory.
5791 To be able to re-map memory U-Boot then jumps to its link address.
5792 To be able to implement the initialization code in C, a (small!)
5793 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5794 which provide such a feature like MPC8xx or MPC8260), or in a locked
5795 part of the data cache. After that, U-Boot initializes the CPU core,
5796 the caches and the SIU.
5798 Next, all (potentially) available memory banks are mapped using a
5799 preliminary mapping. For example, we put them on 512 MB boundaries
5800 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5801 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5802 programmed for SDRAM access. Using the temporary configuration, a
5803 simple memory test is run that determines the size of the SDRAM
5806 When there is more than one SDRAM bank, and the banks are of
5807 different size, the largest is mapped first. For equal size, the first
5808 bank (CS2#) is mapped first. The first mapping is always for address
5809 0x00000000, with any additional banks following immediately to create
5810 contiguous memory starting from 0.
5812 Then, the monitor installs itself at the upper end of the SDRAM area
5813 and allocates memory for use by malloc() and for the global Board
5814 Info data; also, the exception vector code is copied to the low RAM
5815 pages, and the final stack is set up.
5817 Only after this relocation will you have a "normal" C environment;
5818 until that you are restricted in several ways, mostly because you are
5819 running from ROM, and because the code will have to be relocated to a
5823 U-Boot Porting Guide:
5824 ----------------------
5826 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5830 int main(int argc, char *argv[])
5832 sighandler_t no_more_time;
5834 signal(SIGALRM, no_more_time);
5835 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5837 if (available_money > available_manpower) {
5838 Pay consultant to port U-Boot;
5842 Download latest U-Boot source;
5844 Subscribe to u-boot mailing list;
5847 email("Hi, I am new to U-Boot, how do I get started?");
5850 Read the README file in the top level directory;
5851 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5852 Read applicable doc/*.README;
5853 Read the source, Luke;
5854 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5857 if (available_money > toLocalCurrency ($2500))
5860 Add a lot of aggravation and time;
5862 if (a similar board exists) { /* hopefully... */
5863 cp -a board/<similar> board/<myboard>
5864 cp include/configs/<similar>.h include/configs/<myboard>.h
5866 Create your own board support subdirectory;
5867 Create your own board include/configs/<myboard>.h file;
5869 Edit new board/<myboard> files
5870 Edit new include/configs/<myboard>.h
5875 Add / modify source code;
5879 email("Hi, I am having problems...");
5881 Send patch file to the U-Boot email list;
5882 if (reasonable critiques)
5883 Incorporate improvements from email list code review;
5885 Defend code as written;
5891 void no_more_time (int sig)
5900 All contributions to U-Boot should conform to the Linux kernel
5901 coding style; see the file "Documentation/CodingStyle" and the script
5902 "scripts/Lindent" in your Linux kernel source directory.
5904 Source files originating from a different project (for example the
5905 MTD subsystem) are generally exempt from these guidelines and are not
5906 reformated to ease subsequent migration to newer versions of those
5909 Please note that U-Boot is implemented in C (and to some small parts in
5910 Assembler); no C++ is used, so please do not use C++ style comments (//)
5913 Please also stick to the following formatting rules:
5914 - remove any trailing white space
5915 - use TAB characters for indentation and vertical alignment, not spaces
5916 - make sure NOT to use DOS '\r\n' line feeds
5917 - do not add more than 2 consecutive empty lines to source files
5918 - do not add trailing empty lines to source files
5920 Submissions which do not conform to the standards may be returned
5921 with a request to reformat the changes.
5927 Since the number of patches for U-Boot is growing, we need to
5928 establish some rules. Submissions which do not conform to these rules
5929 may be rejected, even when they contain important and valuable stuff.
5931 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5933 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5934 see http://lists.denx.de/mailman/listinfo/u-boot
5936 When you send a patch, please include the following information with
5939 * For bug fixes: a description of the bug and how your patch fixes
5940 this bug. Please try to include a way of demonstrating that the
5941 patch actually fixes something.
5943 * For new features: a description of the feature and your
5946 * A CHANGELOG entry as plaintext (separate from the patch)
5948 * For major contributions, your entry to the CREDITS file
5950 * When you add support for a new board, don't forget to add a
5951 maintainer e-mail address to the boards.cfg file, too.
5953 * If your patch adds new configuration options, don't forget to
5954 document these in the README file.
5956 * The patch itself. If you are using git (which is *strongly*
5957 recommended) you can easily generate the patch using the
5958 "git format-patch". If you then use "git send-email" to send it to
5959 the U-Boot mailing list, you will avoid most of the common problems
5960 with some other mail clients.
5962 If you cannot use git, use "diff -purN OLD NEW". If your version of
5963 diff does not support these options, then get the latest version of
5966 The current directory when running this command shall be the parent
5967 directory of the U-Boot source tree (i. e. please make sure that
5968 your patch includes sufficient directory information for the
5971 We prefer patches as plain text. MIME attachments are discouraged,
5972 and compressed attachments must not be used.
5974 * If one logical set of modifications affects or creates several
5975 files, all these changes shall be submitted in a SINGLE patch file.
5977 * Changesets that contain different, unrelated modifications shall be
5978 submitted as SEPARATE patches, one patch per changeset.
5983 * Before sending the patch, run the MAKEALL script on your patched
5984 source tree and make sure that no errors or warnings are reported
5985 for any of the boards.
5987 * Keep your modifications to the necessary minimum: A patch
5988 containing several unrelated changes or arbitrary reformats will be
5989 returned with a request to re-formatting / split it.
5991 * If you modify existing code, make sure that your new code does not
5992 add to the memory footprint of the code ;-) Small is beautiful!
5993 When adding new features, these should compile conditionally only
5994 (using #ifdef), and the resulting code with the new feature
5995 disabled must not need more memory than the old code without your
5998 * Remember that there is a size limit of 100 kB per message on the
5999 u-boot mailing list. Bigger patches will be moderated. If they are
6000 reasonable and not too big, they will be acknowledged. But patches
6001 bigger than the size limit should be avoided.
projects / people / ms / u-boot.git / blob