2 # (C) Copyright 2000 - 2013
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # SPDX-License-Identifier: GPL-2.0+
11 This directory contains the source code for U-Boot, a boot loader for
12 Embedded boards based on PowerPC, ARM, MIPS and several other
13 processors, which can be installed in a boot ROM and used to
14 initialize and test the hardware or to download and run application
17 The development of U-Boot is closely related to Linux: some parts of
18 the source code originate in the Linux source tree, we have some
19 header files in common, and special provision has been made to
20 support booting of Linux images.
22 Some attention has been paid to make this software easily
23 configurable and extendable. For instance, all monitor commands are
24 implemented with the same call interface, so that it's very easy to
25 add new commands. Also, instead of permanently adding rarely used
26 code (for instance hardware test utilities) to the monitor, you can
27 load and run it dynamically.
33 In general, all boards for which a configuration option exists in the
34 Makefile have been tested to some extent and can be considered
35 "working". In fact, many of them are used in production systems.
37 In case of problems see the CHANGELOG and CREDITS files to find out
38 who contributed the specific port. The boards.cfg file lists board
41 Note: There is no CHANGELOG file in the actual U-Boot source tree;
42 it can be created dynamically from the Git log using:
50 In case you have questions about, problems with or contributions for
51 U-Boot you should send a message to the U-Boot mailing list at
52 <u-boot@lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
58 Where to get source code:
59 =========================
61 The U-Boot source code is maintained in the git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
100 This is the README file for the U-Boot project.
102 File names etc. shall be based on the string "u-boot". Examples:
104 include/asm-ppc/u-boot.h
106 #include <asm/u-boot.h>
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
134 /arch Architecture specific files
135 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /pxa Files specific to Intel XScale PXA CPUs
145 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 /lib Architecture specific library files
147 /avr32 Files generic to AVR32 architecture
148 /cpu CPU specific files
149 /lib Architecture specific library files
150 /blackfin Files generic to Analog Devices Blackfin architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /m68k Files generic to m68k architecture
154 /cpu CPU specific files
155 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
156 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
157 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
158 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
159 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
160 /lib Architecture specific library files
161 /microblaze Files generic to microblaze architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /mips Files generic to MIPS architecture
165 /cpu CPU specific files
166 /mips32 Files specific to MIPS32 CPUs
167 /xburst Files specific to Ingenic XBurst CPUs
168 /lib Architecture specific library files
169 /nds32 Files generic to NDS32 architecture
170 /cpu CPU specific files
171 /n1213 Files specific to Andes Technology N1213 CPUs
172 /lib Architecture specific library files
173 /nios2 Files generic to Altera NIOS2 architecture
174 /cpu CPU specific files
175 /lib Architecture specific library files
176 /openrisc Files generic to OpenRISC architecture
177 /cpu CPU specific files
178 /lib Architecture specific library files
179 /powerpc Files generic to PowerPC architecture
180 /cpu CPU specific files
181 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
182 /mpc5xx Files specific to Freescale MPC5xx CPUs
183 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
184 /mpc8xx Files specific to Freescale MPC8xx CPUs
185 /mpc824x Files specific to Freescale MPC824x CPUs
186 /mpc8260 Files specific to Freescale MPC8260 CPUs
187 /mpc85xx Files specific to Freescale MPC85xx CPUs
188 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
189 /lib Architecture specific library files
190 /sh Files generic to SH architecture
191 /cpu CPU specific files
192 /sh2 Files specific to sh2 CPUs
193 /sh3 Files specific to sh3 CPUs
194 /sh4 Files specific to sh4 CPUs
195 /lib Architecture specific library files
196 /sparc Files generic to SPARC architecture
197 /cpu CPU specific files
198 /leon2 Files specific to Gaisler LEON2 SPARC CPU
199 /leon3 Files specific to Gaisler LEON3 SPARC CPU
200 /lib Architecture specific library files
201 /x86 Files generic to x86 architecture
202 /cpu CPU specific files
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /dts Contains Makefile for building internal U-Boot fdt.
211 /examples Example code for standalone applications, etc.
212 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
213 /include Header Files
214 /lib Files generic to all architectures
215 /libfdt Library files to support flattened device trees
216 /lzma Library files to support LZMA decompression
217 /lzo Library files to support LZO decompression
219 /post Power On Self Test
220 /spl Secondary Program Loader framework
221 /tools Tools to build S-Record or U-Boot images, etc.
223 Software Configuration:
224 =======================
226 Configuration is usually done using C preprocessor defines; the
227 rationale behind that is to avoid dead code whenever possible.
229 There are two classes of configuration variables:
231 * Configuration _OPTIONS_:
232 These are selectable by the user and have names beginning with
235 * Configuration _SETTINGS_:
236 These depend on the hardware etc. and should not be meddled with if
237 you don't know what you're doing; they have names beginning with
240 Later we will add a configuration tool - probably similar to or even
241 identical to what's used for the Linux kernel. Right now, we have to
242 do the configuration by hand, which means creating some symbolic
243 links and editing some configuration files. We use the TQM8xxL boards
247 Selection of Processor Architecture and Board Type:
248 ---------------------------------------------------
250 For all supported boards there are ready-to-use default
251 configurations available; just type "make <board_name>_config".
253 Example: For a TQM823L module type:
258 For the Cogent platform, you need to specify the CPU type as well;
259 e.g. "make cogent_mpc8xx_config". And also configure the cogent
260 directory according to the instructions in cogent/README.
263 Configuration Options:
264 ----------------------
266 Configuration depends on the combination of board and CPU type; all
267 such information is kept in a configuration file
268 "include/configs/<board_name>.h".
270 Example: For a TQM823L module, all configuration settings are in
271 "include/configs/TQM823L.h".
274 Many of the options are named exactly as the corresponding Linux
275 kernel configuration options. The intention is to make it easier to
276 build a config tool - later.
279 The following options need to be configured:
281 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
283 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
285 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
286 Define exactly one, e.g. CONFIG_ATSTK1002
288 - CPU Module Type: (if CONFIG_COGENT is defined)
289 Define exactly one of
291 --- FIXME --- not tested yet:
292 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
293 CONFIG_CMA287_23, CONFIG_CMA287_50
295 - Motherboard Type: (if CONFIG_COGENT is defined)
296 Define exactly one of
297 CONFIG_CMA101, CONFIG_CMA102
299 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
300 Define one or more of
303 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
304 Define one or more of
305 CONFIG_LCD_HEARTBEAT - update a character position on
306 the LCD display every second with
309 - Board flavour: (if CONFIG_MPC8260ADS is defined)
312 CONFIG_SYS_8260ADS - original MPC8260ADS
313 CONFIG_SYS_8266ADS - MPC8266ADS
314 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
315 CONFIG_SYS_8272ADS - MPC8272ADS
317 - Marvell Family Member
318 CONFIG_SYS_MVFS - define it if you want to enable
319 multiple fs option at one time
320 for marvell soc family
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
357 Specifies that the core is a 64-bit PowerPC implementation (implements
358 the "64" category of the Power ISA). This is necessary for ePAPR
359 compliance, among other possible reasons.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 CONFIG_SYS_PPC_E500_DEBUG_TLB
374 Enables a temporary TLB entry to be used during boot to work
375 around limitations in e500v1 and e500v2 external debugger
376 support. This reduces the portions of the boot code where
377 breakpoints and single stepping do not work. The value of this
378 symbol should be set to the TLB1 entry to be used for this
381 CONFIG_SYS_FSL_ERRATUM_A004510
383 Enables a workaround for erratum A004510. If set,
384 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
390 Defines one or two SoC revisions (low 8 bits of SVR)
391 for which the A004510 workaround should be applied.
393 The rest of SVR is either not relevant to the decision
394 of whether the erratum is present (e.g. p2040 versus
395 p2041) or is implied by the build target, which controls
396 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
398 See Freescale App Note 4493 for more information about
401 CONFIG_A003399_NOR_WORKAROUND
402 Enables a workaround for IFC erratum A003399. It is only
403 requred during NOR boot.
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
437 Freescale DDR driver in use. This type of DDR controller is
438 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
441 CONFIG_SYS_FSL_DDR_ADDR
442 Freescale DDR memory-mapped register base.
444 CONFIG_SYS_FSL_DDR_EMU
445 Specify emulator support for DDR. Some DDR features such as
446 deskew training are not available.
448 CONFIG_SYS_FSL_DDRC_GEN1
449 Freescale DDR1 controller.
451 CONFIG_SYS_FSL_DDRC_GEN2
452 Freescale DDR2 controller.
454 CONFIG_SYS_FSL_DDRC_GEN3
455 Freescale DDR3 controller.
457 CONFIG_SYS_FSL_DDRC_ARM_GEN3
458 Freescale DDR3 controller for ARM-based SoCs.
461 Board config to use DDR1. It can be enabled for SoCs with
462 Freescale DDR1 or DDR2 controllers, depending on the board
466 Board config to use DDR2. It can be eanbeld for SoCs with
467 Freescale DDR2 or DDR3 controllers, depending on the board
471 Board config to use DDR3. It can be enabled for SoCs with
472 Freescale DDR3 controllers.
474 CONFIG_SYS_FSL_IFC_BE
475 Defines the IFC controller register space as Big Endian
477 CONFIG_SYS_FSL_IFC_LE
478 Defines the IFC controller register space as Little Endian
480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
489 CONFIG_SYS_FSL_DDR_BE
490 Defines the DDR controller register space as Big Endian
492 CONFIG_SYS_FSL_DDR_LE
493 Defines the DDR controller register space as Little Endian
495 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
496 Physical address from the view of DDR controllers. It is the
497 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
498 it could be different for ARM SoCs.
500 CONFIG_SYS_FSL_DDR_INTLV_256B
501 DDR controller interleaving on 256-byte. This is a special
502 interleaving mode, handled by Dickens for Freescale layerscape
505 - Intel Monahans options:
506 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
508 Defines the Monahans run mode to oscillator
509 ratio. Valid values are 8, 16, 24, 31. The core
510 frequency is this value multiplied by 13 MHz.
512 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
514 Defines the Monahans turbo mode to oscillator
515 ratio. Valid values are 1 (default if undefined) and
516 2. The core frequency as calculated above is multiplied
520 CONFIG_SYS_INIT_SP_OFFSET
522 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
523 pointer. This is needed for the temporary stack before
526 CONFIG_SYS_MIPS_CACHE_MODE
528 Cache operation mode for the MIPS CPU.
529 See also arch/mips/include/asm/mipsregs.h.
531 CONF_CM_CACHABLE_NO_WA
534 CONF_CM_CACHABLE_NONCOHERENT
538 CONF_CM_CACHABLE_ACCELERATED
540 CONFIG_SYS_XWAY_EBU_BOOTCFG
542 Special option for Lantiq XWAY SoCs for booting from NOR flash.
543 See also arch/mips/cpu/mips32/start.S.
545 CONFIG_XWAY_SWAP_BYTES
547 Enable compilation of tools/xway-swap-bytes needed for Lantiq
548 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
549 be swapped if a flash programmer is used.
552 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
554 Select high exception vectors of the ARM core, e.g., do not
555 clear the V bit of the c1 register of CP15.
557 CONFIG_SYS_THUMB_BUILD
559 Use this flag to build U-Boot using the Thumb instruction
560 set for ARM architectures. Thumb instruction set provides
561 better code density. For ARM architectures that support
562 Thumb2 this flag will result in Thumb2 code generated by
565 CONFIG_ARM_ERRATA_716044
566 CONFIG_ARM_ERRATA_742230
567 CONFIG_ARM_ERRATA_743622
568 CONFIG_ARM_ERRATA_751472
569 CONFIG_ARM_ERRATA_794072
571 If set, the workarounds for these ARM errata are applied early
572 during U-Boot startup. Note that these options force the
573 workarounds to be applied; no CPU-type/version detection
574 exists, unlike the similar options in the Linux kernel. Do not
575 set these options unless they apply!
580 The frequency of the timer returned by get_timer().
581 get_timer() must operate in milliseconds and this CONFIG
582 option must be set to 1000.
584 - Linux Kernel Interface:
587 U-Boot stores all clock information in Hz
588 internally. For binary compatibility with older Linux
589 kernels (which expect the clocks passed in the
590 bd_info data to be in MHz) the environment variable
591 "clocks_in_mhz" can be defined so that U-Boot
592 converts clock data to MHZ before passing it to the
594 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
595 "clocks_in_mhz=1" is automatically included in the
598 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
600 When transferring memsize parameter to linux, some versions
601 expect it to be in bytes, others in MB.
602 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
606 New kernel versions are expecting firmware settings to be
607 passed using flattened device trees (based on open firmware
611 * New libfdt-based support
612 * Adds the "fdt" command
613 * The bootm command automatically updates the fdt
615 OF_CPU - The proper name of the cpus node (only required for
616 MPC512X and MPC5xxx based boards).
617 OF_SOC - The proper name of the soc node (only required for
618 MPC512X and MPC5xxx based boards).
619 OF_TBCLK - The timebase frequency.
620 OF_STDOUT_PATH - The path to the console device
622 boards with QUICC Engines require OF_QE to set UCC MAC
625 CONFIG_OF_BOARD_SETUP
627 Board code has addition modification that it wants to make
628 to the flat device tree before handing it off to the kernel
632 This define fills in the correct boot CPU in the boot
633 param header, the default value is zero if undefined.
637 U-Boot can detect if an IDE device is present or not.
638 If not, and this new config option is activated, U-Boot
639 removes the ATA node from the DTS before booting Linux,
640 so the Linux IDE driver does not probe the device and
641 crash. This is needed for buggy hardware (uc101) where
642 no pull down resistor is connected to the signal IDE5V_DD7.
644 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
646 This setting is mandatory for all boards that have only one
647 machine type and must be used to specify the machine type
648 number as it appears in the ARM machine registry
649 (see http://www.arm.linux.org.uk/developer/machines/).
650 Only boards that have multiple machine types supported
651 in a single configuration file and the machine type is
652 runtime discoverable, do not have to use this setting.
654 - vxWorks boot parameters:
656 bootvx constructs a valid bootline using the following
657 environments variables: bootfile, ipaddr, serverip, hostname.
658 It loads the vxWorks image pointed bootfile.
660 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
661 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
662 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
663 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
665 CONFIG_SYS_VXWORKS_ADD_PARAMS
667 Add it at the end of the bootline. E.g "u=username pw=secret"
669 Note: If a "bootargs" environment is defined, it will overwride
670 the defaults discussed just above.
672 - Cache Configuration:
673 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
674 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
675 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
677 - Cache Configuration for ARM:
678 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
680 CONFIG_SYS_PL310_BASE - Physical base address of PL310
681 controller register space
686 Define this if you want support for Amba PrimeCell PL010 UARTs.
690 Define this if you want support for Amba PrimeCell PL011 UARTs.
694 If you have Amba PrimeCell PL011 UARTs, set this variable to
695 the clock speed of the UARTs.
699 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
700 define this to a list of base addresses for each (supported)
701 port. See e.g. include/configs/versatile.h
703 CONFIG_PL011_SERIAL_RLCR
705 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
706 have separate receive and transmit line control registers. Set
707 this variable to initialize the extra register.
709 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
711 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
712 boot loader that has already initialized the UART. Define this
713 variable to flush the UART at init time.
717 Depending on board, define exactly one serial port
718 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
719 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
720 console by defining CONFIG_8xx_CONS_NONE
722 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
723 port routines must be defined elsewhere
724 (i.e. serial_init(), serial_getc(), ...)
727 Enables console device for a color framebuffer. Needs following
728 defines (cf. smiLynxEM, i8042)
729 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
731 VIDEO_HW_RECTFILL graphic chip supports
734 VIDEO_HW_BITBLT graphic chip supports
735 bit-blit (cf. smiLynxEM)
736 VIDEO_VISIBLE_COLS visible pixel columns
738 VIDEO_VISIBLE_ROWS visible pixel rows
739 VIDEO_PIXEL_SIZE bytes per pixel
740 VIDEO_DATA_FORMAT graphic data format
741 (0-5, cf. cfb_console.c)
742 VIDEO_FB_ADRS framebuffer address
743 VIDEO_KBD_INIT_FCT keyboard int fct
744 (i.e. i8042_kbd_init())
745 VIDEO_TSTC_FCT test char fct
747 VIDEO_GETC_FCT get char fct
749 CONFIG_CONSOLE_CURSOR cursor drawing on/off
750 (requires blink timer
752 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
753 CONFIG_CONSOLE_TIME display time/date info in
755 (requires CONFIG_CMD_DATE)
756 CONFIG_VIDEO_LOGO display Linux logo in
758 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
759 linux_logo.h for logo.
760 Requires CONFIG_VIDEO_LOGO
761 CONFIG_CONSOLE_EXTRA_INFO
762 additional board info beside
765 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
766 a limited number of ANSI escape sequences (cursor control,
767 erase functions and limited graphics rendition control).
769 When CONFIG_CFB_CONSOLE is defined, video console is
770 default i/o. Serial console can be forced with
771 environment 'console=serial'.
773 When CONFIG_SILENT_CONSOLE is defined, all console
774 messages (by U-Boot and Linux!) can be silenced with
775 the "silent" environment variable. See
776 doc/README.silent for more information.
778 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
780 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
784 CONFIG_BAUDRATE - in bps
785 Select one of the baudrates listed in
786 CONFIG_SYS_BAUDRATE_TABLE, see below.
787 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
789 - Console Rx buffer length
790 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
791 the maximum receive buffer length for the SMC.
792 This option is actual only for 82xx and 8xx possible.
793 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
794 must be defined, to setup the maximum idle timeout for
797 - Pre-Console Buffer:
798 Prior to the console being initialised (i.e. serial UART
799 initialised etc) all console output is silently discarded.
800 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
801 buffer any console messages prior to the console being
802 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
803 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
804 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
805 bytes are output before the console is initialised, the
806 earlier bytes are discarded.
808 'Sane' compilers will generate smaller code if
809 CONFIG_PRE_CON_BUF_SZ is a power of 2
811 - Safe printf() functions
812 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
813 the printf() functions. These are defined in
814 include/vsprintf.h and include snprintf(), vsnprintf() and
815 so on. Code size increase is approximately 300-500 bytes.
816 If this option is not given then these functions will
817 silently discard their buffer size argument - this means
818 you are not getting any overflow checking in this case.
820 - Boot Delay: CONFIG_BOOTDELAY - in seconds
821 Delay before automatically booting the default image;
822 set to -1 to disable autoboot.
823 set to -2 to autoboot with no delay and not check for abort
824 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
826 See doc/README.autoboot for these options that
827 work with CONFIG_BOOTDELAY. None are required.
828 CONFIG_BOOT_RETRY_TIME
829 CONFIG_BOOT_RETRY_MIN
830 CONFIG_AUTOBOOT_KEYED
831 CONFIG_AUTOBOOT_PROMPT
832 CONFIG_AUTOBOOT_DELAY_STR
833 CONFIG_AUTOBOOT_STOP_STR
834 CONFIG_AUTOBOOT_DELAY_STR2
835 CONFIG_AUTOBOOT_STOP_STR2
836 CONFIG_ZERO_BOOTDELAY_CHECK
837 CONFIG_RESET_TO_RETRY
841 Only needed when CONFIG_BOOTDELAY is enabled;
842 define a command string that is automatically executed
843 when no character is read on the console interface
844 within "Boot Delay" after reset.
847 This can be used to pass arguments to the bootm
848 command. The value of CONFIG_BOOTARGS goes into the
849 environment value "bootargs".
851 CONFIG_RAMBOOT and CONFIG_NFSBOOT
852 The value of these goes into the environment as
853 "ramboot" and "nfsboot" respectively, and can be used
854 as a convenience, when switching between booting from
858 CONFIG_BOOTCOUNT_LIMIT
859 Implements a mechanism for detecting a repeating reboot
861 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
864 If no softreset save registers are found on the hardware
865 "bootcount" is stored in the environment. To prevent a
866 saveenv on all reboots, the environment variable
867 "upgrade_available" is used. If "upgrade_available" is
868 0, "bootcount" is always 0, if "upgrade_available" is
869 1 "bootcount" is incremented in the environment.
870 So the Userspace Applikation must set the "upgrade_available"
871 and "bootcount" variable to 0, if a boot was successfully.
876 When this option is #defined, the existence of the
877 environment variable "preboot" will be checked
878 immediately before starting the CONFIG_BOOTDELAY
879 countdown and/or running the auto-boot command resp.
880 entering interactive mode.
882 This feature is especially useful when "preboot" is
883 automatically generated or modified. For an example
884 see the LWMON board specific code: here "preboot" is
885 modified when the user holds down a certain
886 combination of keys on the (special) keyboard when
889 - Serial Download Echo Mode:
891 If defined to 1, all characters received during a
892 serial download (using the "loads" command) are
893 echoed back. This might be needed by some terminal
894 emulations (like "cu"), but may as well just take
895 time on others. This setting #define's the initial
896 value of the "loads_echo" environment variable.
898 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
900 Select one of the baudrates listed in
901 CONFIG_SYS_BAUDRATE_TABLE, see below.
904 Monitor commands can be included or excluded
905 from the build by using the #include files
906 <config_cmd_all.h> and #undef'ing unwanted
907 commands, or using <config_cmd_default.h>
908 and augmenting with additional #define's
911 The default command configuration includes all commands
912 except those marked below with a "*".
914 CONFIG_CMD_ASKENV * ask for env variable
915 CONFIG_CMD_BDI bdinfo
916 CONFIG_CMD_BEDBUG * Include BedBug Debugger
917 CONFIG_CMD_BMP * BMP support
918 CONFIG_CMD_BSP * Board specific commands
919 CONFIG_CMD_BOOTD bootd
920 CONFIG_CMD_CACHE * icache, dcache
921 CONFIG_CMD_CLK * clock command support
922 CONFIG_CMD_CONSOLE coninfo
923 CONFIG_CMD_CRC32 * crc32
924 CONFIG_CMD_DATE * support for RTC, date/time...
925 CONFIG_CMD_DHCP * DHCP support
926 CONFIG_CMD_DIAG * Diagnostics
927 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
928 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
929 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
930 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
931 CONFIG_CMD_DTT * Digital Therm and Thermostat
932 CONFIG_CMD_ECHO echo arguments
933 CONFIG_CMD_EDITENV edit env variable
934 CONFIG_CMD_EEPROM * EEPROM read/write support
935 CONFIG_CMD_ELF * bootelf, bootvx
936 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
937 CONFIG_CMD_ENV_FLAGS * display details about env flags
938 CONFIG_CMD_ENV_EXISTS * check existence of env variable
939 CONFIG_CMD_EXPORTENV * export the environment
940 CONFIG_CMD_EXT2 * ext2 command support
941 CONFIG_CMD_EXT4 * ext4 command support
942 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
943 that work for multiple fs types
944 CONFIG_CMD_SAVEENV saveenv
945 CONFIG_CMD_FDC * Floppy Disk Support
946 CONFIG_CMD_FAT * FAT command support
947 CONFIG_CMD_FLASH flinfo, erase, protect
948 CONFIG_CMD_FPGA FPGA device initialization support
949 CONFIG_CMD_FUSE * Device fuse support
950 CONFIG_CMD_GETTIME * Get time since boot
951 CONFIG_CMD_GO * the 'go' command (exec code)
952 CONFIG_CMD_GREPENV * search environment
953 CONFIG_CMD_HASH * calculate hash / digest
954 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
955 CONFIG_CMD_I2C * I2C serial bus support
956 CONFIG_CMD_IDE * IDE harddisk support
957 CONFIG_CMD_IMI iminfo
958 CONFIG_CMD_IMLS List all images found in NOR flash
959 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
960 CONFIG_CMD_IMMAP * IMMR dump support
961 CONFIG_CMD_IMPORTENV * import an environment
962 CONFIG_CMD_INI * import data from an ini file into the env
963 CONFIG_CMD_IRQ * irqinfo
964 CONFIG_CMD_ITEST Integer/string test of 2 values
965 CONFIG_CMD_JFFS2 * JFFS2 Support
966 CONFIG_CMD_KGDB * kgdb
967 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
968 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
970 CONFIG_CMD_LOADB loadb
971 CONFIG_CMD_LOADS loads
972 CONFIG_CMD_MD5SUM * print md5 message digest
973 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
974 CONFIG_CMD_MEMINFO * Display detailed memory information
975 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
977 CONFIG_CMD_MEMTEST * mtest
978 CONFIG_CMD_MISC Misc functions like sleep etc
979 CONFIG_CMD_MMC * MMC memory mapped support
980 CONFIG_CMD_MII * MII utility commands
981 CONFIG_CMD_MTDPARTS * MTD partition support
982 CONFIG_CMD_NAND * NAND support
983 CONFIG_CMD_NET bootp, tftpboot, rarpboot
984 CONFIG_CMD_NFS NFS support
985 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
986 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
987 CONFIG_CMD_PCI * pciinfo
988 CONFIG_CMD_PCMCIA * PCMCIA support
989 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
991 CONFIG_CMD_PORTIO * Port I/O
992 CONFIG_CMD_READ * Read raw data from partition
993 CONFIG_CMD_REGINFO * Register dump
994 CONFIG_CMD_RUN run command in env variable
995 CONFIG_CMD_SANDBOX * sb command to access sandbox features
996 CONFIG_CMD_SAVES * save S record dump
997 CONFIG_CMD_SCSI * SCSI Support
998 CONFIG_CMD_SDRAM * print SDRAM configuration information
999 (requires CONFIG_CMD_I2C)
1000 CONFIG_CMD_SETGETDCR Support for DCR Register access
1002 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1003 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1004 (requires CONFIG_CMD_MEMORY)
1005 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1006 CONFIG_CMD_SOURCE "source" command Support
1007 CONFIG_CMD_SPI * SPI serial bus support
1008 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1009 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1010 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1011 CONFIG_CMD_TIMER * access to the system tick timer
1012 CONFIG_CMD_USB * USB support
1013 CONFIG_CMD_CDP * Cisco Discover Protocol support
1014 CONFIG_CMD_MFSL * Microblaze FSL support
1015 CONFIG_CMD_XIMG Load part of Multi Image
1018 EXAMPLE: If you want all functions except of network
1019 support you can write:
1021 #include "config_cmd_all.h"
1022 #undef CONFIG_CMD_NET
1025 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1027 Note: Don't enable the "icache" and "dcache" commands
1028 (configuration option CONFIG_CMD_CACHE) unless you know
1029 what you (and your U-Boot users) are doing. Data
1030 cache cannot be enabled on systems like the 8xx or
1031 8260 (where accesses to the IMMR region must be
1032 uncached), and it cannot be disabled on all other
1033 systems where we (mis-) use the data cache to hold an
1034 initial stack and some data.
1037 XXX - this list needs to get updated!
1039 - Regular expression support:
1041 If this variable is defined, U-Boot is linked against
1042 the SLRE (Super Light Regular Expression) library,
1043 which adds regex support to some commands, as for
1044 example "env grep" and "setexpr".
1048 If this variable is defined, U-Boot will use a device tree
1049 to configure its devices, instead of relying on statically
1050 compiled #defines in the board file. This option is
1051 experimental and only available on a few boards. The device
1052 tree is available in the global data as gd->fdt_blob.
1054 U-Boot needs to get its device tree from somewhere. This can
1055 be done using one of the two options below:
1058 If this variable is defined, U-Boot will embed a device tree
1059 binary in its image. This device tree file should be in the
1060 board directory and called <soc>-<board>.dts. The binary file
1061 is then picked up in board_init_f() and made available through
1062 the global data structure as gd->blob.
1065 If this variable is defined, U-Boot will build a device tree
1066 binary. It will be called u-boot.dtb. Architecture-specific
1067 code will locate it at run-time. Generally this works by:
1069 cat u-boot.bin u-boot.dtb >image.bin
1071 and in fact, U-Boot does this for you, creating a file called
1072 u-boot-dtb.bin which is useful in the common case. You can
1073 still use the individual files if you need something more
1078 If this variable is defined, it enables watchdog
1079 support for the SoC. There must be support in the SoC
1080 specific code for a watchdog. For the 8xx and 8260
1081 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1082 register. When supported for a specific SoC is
1083 available, then no further board specific code should
1084 be needed to use it.
1087 When using a watchdog circuitry external to the used
1088 SoC, then define this variable and provide board
1089 specific code for the "hw_watchdog_reset" function.
1092 CONFIG_VERSION_VARIABLE
1093 If this variable is defined, an environment variable
1094 named "ver" is created by U-Boot showing the U-Boot
1095 version as printed by the "version" command.
1096 Any change to this variable will be reverted at the
1101 When CONFIG_CMD_DATE is selected, the type of the RTC
1102 has to be selected, too. Define exactly one of the
1105 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1106 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1107 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1108 CONFIG_RTC_MC146818 - use MC146818 RTC
1109 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1110 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1111 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1112 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1113 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1114 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1115 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1116 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1119 Note that if the RTC uses I2C, then the I2C interface
1120 must also be configured. See I2C Support, below.
1123 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1125 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1126 chip-ngpio pairs that tell the PCA953X driver the number of
1127 pins supported by a particular chip.
1129 Note that if the GPIO device uses I2C, then the I2C interface
1130 must also be configured. See I2C Support, below.
1132 - Timestamp Support:
1134 When CONFIG_TIMESTAMP is selected, the timestamp
1135 (date and time) of an image is printed by image
1136 commands like bootm or iminfo. This option is
1137 automatically enabled when you select CONFIG_CMD_DATE .
1139 - Partition Labels (disklabels) Supported:
1140 Zero or more of the following:
1141 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1142 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1143 Intel architecture, USB sticks, etc.
1144 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1145 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1146 bootloader. Note 2TB partition limit; see
1148 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1150 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1151 CONFIG_CMD_SCSI) you must configure support for at
1152 least one non-MTD partition type as well.
1155 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1156 board configurations files but used nowhere!
1158 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1159 be performed by calling the function
1160 ide_set_reset(int reset)
1161 which has to be defined in a board specific file
1166 Set this to enable ATAPI support.
1171 Set this to enable support for disks larger than 137GB
1172 Also look at CONFIG_SYS_64BIT_LBA.
1173 Whithout these , LBA48 support uses 32bit variables and will 'only'
1174 support disks up to 2.1TB.
1176 CONFIG_SYS_64BIT_LBA:
1177 When enabled, makes the IDE subsystem use 64bit sector addresses.
1181 At the moment only there is only support for the
1182 SYM53C8XX SCSI controller; define
1183 CONFIG_SCSI_SYM53C8XX to enable it.
1185 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1186 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1187 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1188 maximum numbers of LUNs, SCSI ID's and target
1190 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1192 The environment variable 'scsidevs' is set to the number of
1193 SCSI devices found during the last scan.
1195 - NETWORK Support (PCI):
1197 Support for Intel 8254x/8257x gigabit chips.
1200 Utility code for direct access to the SPI bus on Intel 8257x.
1201 This does not do anything useful unless you set at least one
1202 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1204 CONFIG_E1000_SPI_GENERIC
1205 Allow generic access to the SPI bus on the Intel 8257x, for
1206 example with the "sspi" command.
1209 Management command for E1000 devices. When used on devices
1210 with SPI support you can reprogram the EEPROM from U-Boot.
1212 CONFIG_E1000_FALLBACK_MAC
1213 default MAC for empty EEPROM after production.
1216 Support for Intel 82557/82559/82559ER chips.
1217 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1218 write routine for first time initialisation.
1221 Support for Digital 2114x chips.
1222 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1223 modem chip initialisation (KS8761/QS6611).
1226 Support for National dp83815 chips.
1229 Support for National dp8382[01] gigabit chips.
1231 - NETWORK Support (other):
1233 CONFIG_DRIVER_AT91EMAC
1234 Support for AT91RM9200 EMAC.
1237 Define this to use reduced MII inteface
1239 CONFIG_DRIVER_AT91EMAC_QUIET
1240 If this defined, the driver is quiet.
1241 The driver doen't show link status messages.
1243 CONFIG_CALXEDA_XGMAC
1244 Support for the Calxeda XGMAC device
1247 Support for SMSC's LAN91C96 chips.
1249 CONFIG_LAN91C96_BASE
1250 Define this to hold the physical address
1251 of the LAN91C96's I/O space
1253 CONFIG_LAN91C96_USE_32_BIT
1254 Define this to enable 32 bit addressing
1257 Support for SMSC's LAN91C111 chip
1259 CONFIG_SMC91111_BASE
1260 Define this to hold the physical address
1261 of the device (I/O space)
1263 CONFIG_SMC_USE_32_BIT
1264 Define this if data bus is 32 bits
1266 CONFIG_SMC_USE_IOFUNCS
1267 Define this to use i/o functions instead of macros
1268 (some hardware wont work with macros)
1270 CONFIG_DRIVER_TI_EMAC
1271 Support for davinci emac
1273 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1274 Define this if you have more then 3 PHYs.
1277 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1279 CONFIG_FTGMAC100_EGIGA
1280 Define this to use GE link update with gigabit PHY.
1281 Define this if FTGMAC100 is connected to gigabit PHY.
1282 If your system has 10/100 PHY only, it might not occur
1283 wrong behavior. Because PHY usually return timeout or
1284 useless data when polling gigabit status and gigabit
1285 control registers. This behavior won't affect the
1286 correctnessof 10/100 link speed update.
1289 Support for SMSC's LAN911x and LAN921x chips
1292 Define this to hold the physical address
1293 of the device (I/O space)
1295 CONFIG_SMC911X_32_BIT
1296 Define this if data bus is 32 bits
1298 CONFIG_SMC911X_16_BIT
1299 Define this if data bus is 16 bits. If your processor
1300 automatically converts one 32 bit word to two 16 bit
1301 words you may also try CONFIG_SMC911X_32_BIT.
1304 Support for Renesas on-chip Ethernet controller
1306 CONFIG_SH_ETHER_USE_PORT
1307 Define the number of ports to be used
1309 CONFIG_SH_ETHER_PHY_ADDR
1310 Define the ETH PHY's address
1312 CONFIG_SH_ETHER_CACHE_WRITEBACK
1313 If this option is set, the driver enables cache flush.
1317 Support TPM devices.
1320 Support for i2c bus TPM devices. Only one device
1321 per system is supported at this time.
1323 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1324 Define the the i2c bus number for the TPM device
1326 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1327 Define the TPM's address on the i2c bus
1329 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1330 Define the burst count bytes upper limit
1332 CONFIG_TPM_ATMEL_TWI
1333 Support for Atmel TWI TPM device. Requires I2C support.
1336 Support for generic parallel port TPM devices. Only one device
1337 per system is supported at this time.
1339 CONFIG_TPM_TIS_BASE_ADDRESS
1340 Base address where the generic TPM device is mapped
1341 to. Contemporary x86 systems usually map it at
1345 Add tpm monitor functions.
1346 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1347 provides monitor access to authorized functions.
1350 Define this to enable the TPM support library which provides
1351 functional interfaces to some TPM commands.
1352 Requires support for a TPM device.
1354 CONFIG_TPM_AUTH_SESSIONS
1355 Define this to enable authorized functions in the TPM library.
1356 Requires CONFIG_TPM and CONFIG_SHA1.
1359 At the moment only the UHCI host controller is
1360 supported (PIP405, MIP405, MPC5200); define
1361 CONFIG_USB_UHCI to enable it.
1362 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1363 and define CONFIG_USB_STORAGE to enable the USB
1366 Supported are USB Keyboards and USB Floppy drives
1368 MPC5200 USB requires additional defines:
1370 for 528 MHz Clock: 0x0001bbbb
1374 for differential drivers: 0x00001000
1375 for single ended drivers: 0x00005000
1376 for differential drivers on PSC3: 0x00000100
1377 for single ended drivers on PSC3: 0x00004100
1378 CONFIG_SYS_USB_EVENT_POLL
1379 May be defined to allow interrupt polling
1380 instead of using asynchronous interrupts
1382 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1383 txfilltuning field in the EHCI controller on reset.
1385 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1386 interval for usb hub power-on delay.(minimum 100msec)
1389 Define the below if you wish to use the USB console.
1390 Once firmware is rebuilt from a serial console issue the
1391 command "setenv stdin usbtty; setenv stdout usbtty" and
1392 attach your USB cable. The Unix command "dmesg" should print
1393 it has found a new device. The environment variable usbtty
1394 can be set to gserial or cdc_acm to enable your device to
1395 appear to a USB host as a Linux gserial device or a
1396 Common Device Class Abstract Control Model serial device.
1397 If you select usbtty = gserial you should be able to enumerate
1399 # modprobe usbserial vendor=0xVendorID product=0xProductID
1400 else if using cdc_acm, simply setting the environment
1401 variable usbtty to be cdc_acm should suffice. The following
1402 might be defined in YourBoardName.h
1405 Define this to build a UDC device
1408 Define this to have a tty type of device available to
1409 talk to the UDC device
1412 Define this to enable the high speed support for usb
1413 device and usbtty. If this feature is enabled, a routine
1414 int is_usbd_high_speed(void)
1415 also needs to be defined by the driver to dynamically poll
1416 whether the enumeration has succeded at high speed or full
1419 CONFIG_SYS_CONSOLE_IS_IN_ENV
1420 Define this if you want stdin, stdout &/or stderr to
1424 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1425 Derive USB clock from external clock "blah"
1426 - CONFIG_SYS_USB_EXTC_CLK 0x02
1428 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1429 Derive USB clock from brgclk
1430 - CONFIG_SYS_USB_BRG_CLK 0x04
1432 If you have a USB-IF assigned VendorID then you may wish to
1433 define your own vendor specific values either in BoardName.h
1434 or directly in usbd_vendor_info.h. If you don't define
1435 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1436 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1437 should pretend to be a Linux device to it's target host.
1439 CONFIG_USBD_MANUFACTURER
1440 Define this string as the name of your company for
1441 - CONFIG_USBD_MANUFACTURER "my company"
1443 CONFIG_USBD_PRODUCT_NAME
1444 Define this string as the name of your product
1445 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1447 CONFIG_USBD_VENDORID
1448 Define this as your assigned Vendor ID from the USB
1449 Implementors Forum. This *must* be a genuine Vendor ID
1450 to avoid polluting the USB namespace.
1451 - CONFIG_USBD_VENDORID 0xFFFF
1453 CONFIG_USBD_PRODUCTID
1454 Define this as the unique Product ID
1456 - CONFIG_USBD_PRODUCTID 0xFFFF
1458 Some USB device drivers may need to check USB cable attachment.
1459 In this case you can enable following config in BoardName.h:
1460 CONFIG_USB_CABLE_CHECK
1461 This enables function definition:
1462 - usb_cable_connected() in include/usb.h
1463 Implementation of this function is board-specific.
1465 - ULPI Layer Support:
1466 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1467 the generic ULPI layer. The generic layer accesses the ULPI PHY
1468 via the platform viewport, so you need both the genric layer and
1469 the viewport enabled. Currently only Chipidea/ARC based
1470 viewport is supported.
1471 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1472 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1473 If your ULPI phy needs a different reference clock than the
1474 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1475 the appropriate value in Hz.
1478 The MMC controller on the Intel PXA is supported. To
1479 enable this define CONFIG_MMC. The MMC can be
1480 accessed from the boot prompt by mapping the device
1481 to physical memory similar to flash. Command line is
1482 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1483 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1486 Support for Renesas on-chip MMCIF controller
1488 CONFIG_SH_MMCIF_ADDR
1489 Define the base address of MMCIF registers
1492 Define the clock frequency for MMCIF
1494 - USB Device Firmware Update (DFU) class support:
1496 This enables the USB portion of the DFU USB class
1499 This enables the command "dfu" which is used to have
1500 U-Boot create a DFU class device via USB. This command
1501 requires that the "dfu_alt_info" environment variable be
1502 set and define the alt settings to expose to the host.
1505 This enables support for exposing (e)MMC devices via DFU.
1508 This enables support for exposing NAND devices via DFU.
1511 This enables support for exposing RAM via DFU.
1512 Note: DFU spec refer to non-volatile memory usage, but
1513 allow usages beyond the scope of spec - here RAM usage,
1514 one that would help mostly the developer.
1516 CONFIG_SYS_DFU_DATA_BUF_SIZE
1517 Dfu transfer uses a buffer before writing data to the
1518 raw storage device. Make the size (in bytes) of this buffer
1519 configurable. The size of this buffer is also configurable
1520 through the "dfu_bufsiz" environment variable.
1522 CONFIG_SYS_DFU_MAX_FILE_SIZE
1523 When updating files rather than the raw storage device,
1524 we use a static buffer to copy the file into and then write
1525 the buffer once we've been given the whole file. Define
1526 this to the maximum filesize (in bytes) for the buffer.
1527 Default is 4 MiB if undefined.
1529 - Journaling Flash filesystem support:
1530 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1531 CONFIG_JFFS2_NAND_DEV
1532 Define these for a default partition on a NAND device
1534 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1535 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1536 Define these for a default partition on a NOR device
1538 CONFIG_SYS_JFFS_CUSTOM_PART
1539 Define this to create an own partition. You have to provide a
1540 function struct part_info* jffs2_part_info(int part_num)
1542 If you define only one JFFS2 partition you may also want to
1543 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1544 to disable the command chpart. This is the default when you
1545 have not defined a custom partition
1547 - FAT(File Allocation Table) filesystem write function support:
1550 Define this to enable support for saving memory data as a
1551 file in FAT formatted partition.
1553 This will also enable the command "fatwrite" enabling the
1554 user to write files to FAT.
1556 CBFS (Coreboot Filesystem) support
1559 Define this to enable support for reading from a Coreboot
1560 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1566 Define this to enable standard (PC-Style) keyboard
1570 Standard PC keyboard driver with US (is default) and
1571 GERMAN key layout (switch via environment 'keymap=de') support.
1572 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1573 for cfb_console. Supports cursor blinking.
1576 Enables a Chrome OS keyboard using the CROS_EC interface.
1577 This uses CROS_EC to communicate with a second microcontroller
1578 which provides key scans on request.
1583 Define this to enable video support (for output to
1586 CONFIG_VIDEO_CT69000
1588 Enable Chips & Technologies 69000 Video chip
1590 CONFIG_VIDEO_SMI_LYNXEM
1591 Enable Silicon Motion SMI 712/710/810 Video chip. The
1592 video output is selected via environment 'videoout'
1593 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1596 For the CT69000 and SMI_LYNXEM drivers, videomode is
1597 selected via environment 'videomode'. Two different ways
1599 - "videomode=num" 'num' is a standard LiLo mode numbers.
1600 Following standard modes are supported (* is default):
1602 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1603 -------------+---------------------------------------------
1604 8 bits | 0x301* 0x303 0x305 0x161 0x307
1605 15 bits | 0x310 0x313 0x316 0x162 0x319
1606 16 bits | 0x311 0x314 0x317 0x163 0x31A
1607 24 bits | 0x312 0x315 0x318 ? 0x31B
1608 -------------+---------------------------------------------
1609 (i.e. setenv videomode 317; saveenv; reset;)
1611 - "videomode=bootargs" all the video parameters are parsed
1612 from the bootargs. (See drivers/video/videomodes.c)
1615 CONFIG_VIDEO_SED13806
1616 Enable Epson SED13806 driver. This driver supports 8bpp
1617 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1618 or CONFIG_VIDEO_SED13806_16BPP
1621 Enable the Freescale DIU video driver. Reference boards for
1622 SOCs that have a DIU should define this macro to enable DIU
1623 support, and should also define these other macros:
1629 CONFIG_VIDEO_SW_CURSOR
1630 CONFIG_VGA_AS_SINGLE_DEVICE
1632 CONFIG_VIDEO_BMP_LOGO
1634 The DIU driver will look for the 'video-mode' environment
1635 variable, and if defined, enable the DIU as a console during
1636 boot. See the documentation file README.video for a
1637 description of this variable.
1641 Enable the VGA video / BIOS for x86. The alternative if you
1642 are using coreboot is to use the coreboot frame buffer
1649 Define this to enable a custom keyboard support.
1650 This simply calls drv_keyboard_init() which must be
1651 defined in your board-specific files.
1652 The only board using this so far is RBC823.
1654 - LCD Support: CONFIG_LCD
1656 Define this to enable LCD support (for output to LCD
1657 display); also select one of the supported displays
1658 by defining one of these:
1662 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1664 CONFIG_NEC_NL6448AC33:
1666 NEC NL6448AC33-18. Active, color, single scan.
1668 CONFIG_NEC_NL6448BC20
1670 NEC NL6448BC20-08. 6.5", 640x480.
1671 Active, color, single scan.
1673 CONFIG_NEC_NL6448BC33_54
1675 NEC NL6448BC33-54. 10.4", 640x480.
1676 Active, color, single scan.
1680 Sharp 320x240. Active, color, single scan.
1681 It isn't 16x9, and I am not sure what it is.
1683 CONFIG_SHARP_LQ64D341
1685 Sharp LQ64D341 display, 640x480.
1686 Active, color, single scan.
1690 HLD1045 display, 640x480.
1691 Active, color, single scan.
1695 Optrex CBL50840-2 NF-FW 99 22 M5
1697 Hitachi LMG6912RPFC-00T
1701 320x240. Black & white.
1703 Normally display is black on white background; define
1704 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1706 CONFIG_LCD_ALIGNMENT
1708 Normally the LCD is page-aligned (tyically 4KB). If this is
1709 defined then the LCD will be aligned to this value instead.
1710 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1711 here, since it is cheaper to change data cache settings on
1712 a per-section basis.
1714 CONFIG_CONSOLE_SCROLL_LINES
1716 When the console need to be scrolled, this is the number of
1717 lines to scroll by. It defaults to 1. Increasing this makes
1718 the console jump but can help speed up operation when scrolling
1723 Support drawing of RLE8-compressed bitmaps on the LCD.
1727 Enables an 'i2c edid' command which can read EDID
1728 information over I2C from an attached LCD display.
1730 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1732 If this option is set, the environment is checked for
1733 a variable "splashimage". If found, the usual display
1734 of logo, copyright and system information on the LCD
1735 is suppressed and the BMP image at the address
1736 specified in "splashimage" is loaded instead. The
1737 console is redirected to the "nulldev", too. This
1738 allows for a "silent" boot where a splash screen is
1739 loaded very quickly after power-on.
1741 CONFIG_SPLASHIMAGE_GUARD
1743 If this option is set, then U-Boot will prevent the environment
1744 variable "splashimage" from being set to a problematic address
1745 (see README.displaying-bmps).
1746 This option is useful for targets where, due to alignment
1747 restrictions, an improperly aligned BMP image will cause a data
1748 abort. If you think you will not have problems with unaligned
1749 accesses (for example because your toolchain prevents them)
1750 there is no need to set this option.
1752 CONFIG_SPLASH_SCREEN_ALIGN
1754 If this option is set the splash image can be freely positioned
1755 on the screen. Environment variable "splashpos" specifies the
1756 position as "x,y". If a positive number is given it is used as
1757 number of pixel from left/top. If a negative number is given it
1758 is used as number of pixel from right/bottom. You can also
1759 specify 'm' for centering the image.
1762 setenv splashpos m,m
1763 => image at center of screen
1765 setenv splashpos 30,20
1766 => image at x = 30 and y = 20
1768 setenv splashpos -10,m
1769 => vertically centered image
1770 at x = dspWidth - bmpWidth - 9
1772 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1774 If this option is set, additionally to standard BMP
1775 images, gzipped BMP images can be displayed via the
1776 splashscreen support or the bmp command.
1778 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1780 If this option is set, 8-bit RLE compressed BMP images
1781 can be displayed via the splashscreen support or the
1784 - Do compresssing for memory range:
1787 If this option is set, it would use zlib deflate method
1788 to compress the specified memory at its best effort.
1790 - Compression support:
1793 Enabled by default to support gzip compressed images.
1797 If this option is set, support for bzip2 compressed
1798 images is included. If not, only uncompressed and gzip
1799 compressed images are supported.
1801 NOTE: the bzip2 algorithm requires a lot of RAM, so
1802 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1807 If this option is set, support for lzma compressed
1810 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1811 requires an amount of dynamic memory that is given by the
1814 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1816 Where lc and lp stand for, respectively, Literal context bits
1817 and Literal pos bits.
1819 This value is upper-bounded by 14MB in the worst case. Anyway,
1820 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1821 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1822 a very small buffer.
1824 Use the lzmainfo tool to determinate the lc and lp values and
1825 then calculate the amount of needed dynamic memory (ensuring
1826 the appropriate CONFIG_SYS_MALLOC_LEN value).
1830 If this option is set, support for LZO compressed images
1836 The address of PHY on MII bus.
1838 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1840 The clock frequency of the MII bus
1844 If this option is set, support for speed/duplex
1845 detection of gigabit PHY is included.
1847 CONFIG_PHY_RESET_DELAY
1849 Some PHY like Intel LXT971A need extra delay after
1850 reset before any MII register access is possible.
1851 For such PHY, set this option to the usec delay
1852 required. (minimum 300usec for LXT971A)
1854 CONFIG_PHY_CMD_DELAY (ppc4xx)
1856 Some PHY like Intel LXT971A need extra delay after
1857 command issued before MII status register can be read
1867 Define a default value for Ethernet address to use
1868 for the respective Ethernet interface, in case this
1869 is not determined automatically.
1874 Define a default value for the IP address to use for
1875 the default Ethernet interface, in case this is not
1876 determined through e.g. bootp.
1877 (Environment variable "ipaddr")
1879 - Server IP address:
1882 Defines a default value for the IP address of a TFTP
1883 server to contact when using the "tftboot" command.
1884 (Environment variable "serverip")
1886 CONFIG_KEEP_SERVERADDR
1888 Keeps the server's MAC address, in the env 'serveraddr'
1889 for passing to bootargs (like Linux's netconsole option)
1891 - Gateway IP address:
1894 Defines a default value for the IP address of the
1895 default router where packets to other networks are
1897 (Environment variable "gatewayip")
1902 Defines a default value for the subnet mask (or
1903 routing prefix) which is used to determine if an IP
1904 address belongs to the local subnet or needs to be
1905 forwarded through a router.
1906 (Environment variable "netmask")
1908 - Multicast TFTP Mode:
1911 Defines whether you want to support multicast TFTP as per
1912 rfc-2090; for example to work with atftp. Lets lots of targets
1913 tftp down the same boot image concurrently. Note: the Ethernet
1914 driver in use must provide a function: mcast() to join/leave a
1917 - BOOTP Recovery Mode:
1918 CONFIG_BOOTP_RANDOM_DELAY
1920 If you have many targets in a network that try to
1921 boot using BOOTP, you may want to avoid that all
1922 systems send out BOOTP requests at precisely the same
1923 moment (which would happen for instance at recovery
1924 from a power failure, when all systems will try to
1925 boot, thus flooding the BOOTP server. Defining
1926 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1927 inserted before sending out BOOTP requests. The
1928 following delays are inserted then:
1930 1st BOOTP request: delay 0 ... 1 sec
1931 2nd BOOTP request: delay 0 ... 2 sec
1932 3rd BOOTP request: delay 0 ... 4 sec
1934 BOOTP requests: delay 0 ... 8 sec
1936 - DHCP Advanced Options:
1937 You can fine tune the DHCP functionality by defining
1938 CONFIG_BOOTP_* symbols:
1940 CONFIG_BOOTP_SUBNETMASK
1941 CONFIG_BOOTP_GATEWAY
1942 CONFIG_BOOTP_HOSTNAME
1943 CONFIG_BOOTP_NISDOMAIN
1944 CONFIG_BOOTP_BOOTPATH
1945 CONFIG_BOOTP_BOOTFILESIZE
1948 CONFIG_BOOTP_SEND_HOSTNAME
1949 CONFIG_BOOTP_NTPSERVER
1950 CONFIG_BOOTP_TIMEOFFSET
1951 CONFIG_BOOTP_VENDOREX
1952 CONFIG_BOOTP_MAY_FAIL
1954 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1955 environment variable, not the BOOTP server.
1957 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1958 after the configured retry count, the call will fail
1959 instead of starting over. This can be used to fail over
1960 to Link-local IP address configuration if the DHCP server
1963 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1964 serverip from a DHCP server, it is possible that more
1965 than one DNS serverip is offered to the client.
1966 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1967 serverip will be stored in the additional environment
1968 variable "dnsip2". The first DNS serverip is always
1969 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1972 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1973 to do a dynamic update of a DNS server. To do this, they
1974 need the hostname of the DHCP requester.
1975 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1976 of the "hostname" environment variable is passed as
1977 option 12 to the DHCP server.
1979 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1981 A 32bit value in microseconds for a delay between
1982 receiving a "DHCP Offer" and sending the "DHCP Request".
1983 This fixes a problem with certain DHCP servers that don't
1984 respond 100% of the time to a "DHCP request". E.g. On an
1985 AT91RM9200 processor running at 180MHz, this delay needed
1986 to be *at least* 15,000 usec before a Windows Server 2003
1987 DHCP server would reply 100% of the time. I recommend at
1988 least 50,000 usec to be safe. The alternative is to hope
1989 that one of the retries will be successful but note that
1990 the DHCP timeout and retry process takes a longer than
1993 - Link-local IP address negotiation:
1994 Negotiate with other link-local clients on the local network
1995 for an address that doesn't require explicit configuration.
1996 This is especially useful if a DHCP server cannot be guaranteed
1997 to exist in all environments that the device must operate.
1999 See doc/README.link-local for more information.
2002 CONFIG_CDP_DEVICE_ID
2004 The device id used in CDP trigger frames.
2006 CONFIG_CDP_DEVICE_ID_PREFIX
2008 A two character string which is prefixed to the MAC address
2013 A printf format string which contains the ascii name of
2014 the port. Normally is set to "eth%d" which sets
2015 eth0 for the first Ethernet, eth1 for the second etc.
2017 CONFIG_CDP_CAPABILITIES
2019 A 32bit integer which indicates the device capabilities;
2020 0x00000010 for a normal host which does not forwards.
2024 An ascii string containing the version of the software.
2028 An ascii string containing the name of the platform.
2032 A 32bit integer sent on the trigger.
2034 CONFIG_CDP_POWER_CONSUMPTION
2036 A 16bit integer containing the power consumption of the
2037 device in .1 of milliwatts.
2039 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2041 A byte containing the id of the VLAN.
2043 - Status LED: CONFIG_STATUS_LED
2045 Several configurations allow to display the current
2046 status using a LED. For instance, the LED will blink
2047 fast while running U-Boot code, stop blinking as
2048 soon as a reply to a BOOTP request was received, and
2049 start blinking slow once the Linux kernel is running
2050 (supported by a status LED driver in the Linux
2051 kernel). Defining CONFIG_STATUS_LED enables this
2057 The status LED can be connected to a GPIO pin.
2058 In such cases, the gpio_led driver can be used as a
2059 status LED backend implementation. Define CONFIG_GPIO_LED
2060 to include the gpio_led driver in the U-Boot binary.
2062 CONFIG_GPIO_LED_INVERTED_TABLE
2063 Some GPIO connected LEDs may have inverted polarity in which
2064 case the GPIO high value corresponds to LED off state and
2065 GPIO low value corresponds to LED on state.
2066 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2067 with a list of GPIO LEDs that have inverted polarity.
2069 - CAN Support: CONFIG_CAN_DRIVER
2071 Defining CONFIG_CAN_DRIVER enables CAN driver support
2072 on those systems that support this (optional)
2073 feature, like the TQM8xxL modules.
2075 - I2C Support: CONFIG_SYS_I2C
2077 This enable the NEW i2c subsystem, and will allow you to use
2078 i2c commands at the u-boot command line (as long as you set
2079 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2080 based realtime clock chips or other i2c devices. See
2081 common/cmd_i2c.c for a description of the command line
2084 ported i2c driver to the new framework:
2085 - drivers/i2c/soft_i2c.c:
2086 - activate first bus with CONFIG_SYS_I2C_SOFT define
2087 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2088 for defining speed and slave address
2089 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2090 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2091 for defining speed and slave address
2092 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2093 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2094 for defining speed and slave address
2095 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2096 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2097 for defining speed and slave address
2099 - drivers/i2c/fsl_i2c.c:
2100 - activate i2c driver with CONFIG_SYS_I2C_FSL
2101 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2102 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2103 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2105 - If your board supports a second fsl i2c bus, define
2106 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2107 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2108 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2111 - drivers/i2c/tegra_i2c.c:
2112 - activate this driver with CONFIG_SYS_I2C_TEGRA
2113 - This driver adds 4 i2c buses with a fix speed from
2114 100000 and the slave addr 0!
2116 - drivers/i2c/ppc4xx_i2c.c
2117 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2118 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2119 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2121 - drivers/i2c/i2c_mxc.c
2122 - activate this driver with CONFIG_SYS_I2C_MXC
2123 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2124 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2125 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2126 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2127 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2128 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2129 If thoses defines are not set, default value is 100000
2130 for speed, and 0 for slave.
2132 - drivers/i2c/rcar_i2c.c:
2133 - activate this driver with CONFIG_SYS_I2C_RCAR
2134 - This driver adds 4 i2c buses
2136 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2137 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2138 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2139 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2140 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2141 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2142 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2143 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2144 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2146 - drivers/i2c/sh_i2c.c:
2147 - activate this driver with CONFIG_SYS_I2C_SH
2148 - This driver adds from 2 to 5 i2c buses
2150 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2151 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2152 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2153 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2154 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2155 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2156 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2157 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2158 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2159 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2160 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2161 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2162 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2164 - drivers/i2c/omap24xx_i2c.c
2165 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2166 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2167 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2168 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2169 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2170 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2171 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2172 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2173 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2174 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2175 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2177 - drivers/i2c/zynq_i2c.c
2178 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2179 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2180 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2182 - drivers/i2c/s3c24x0_i2c.c:
2183 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2184 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2185 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2186 with a fix speed from 100000 and the slave addr 0!
2190 CONFIG_SYS_NUM_I2C_BUSES
2191 Hold the number of i2c busses you want to use. If you
2192 don't use/have i2c muxes on your i2c bus, this
2193 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2196 CONFIG_SYS_I2C_DIRECT_BUS
2197 define this, if you don't use i2c muxes on your hardware.
2198 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2201 CONFIG_SYS_I2C_MAX_HOPS
2202 define how many muxes are maximal consecutively connected
2203 on one i2c bus. If you not use i2c muxes, omit this
2206 CONFIG_SYS_I2C_BUSES
2207 hold a list of busses you want to use, only used if
2208 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2209 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2210 CONFIG_SYS_NUM_I2C_BUSES = 9:
2212 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2213 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2214 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2215 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2216 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2217 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2218 {1, {I2C_NULL_HOP}}, \
2219 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2220 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2224 bus 0 on adapter 0 without a mux
2225 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2226 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2227 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2228 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2229 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2230 bus 6 on adapter 1 without a mux
2231 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2232 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2234 If you do not have i2c muxes on your board, omit this define.
2236 - Legacy I2C Support: CONFIG_HARD_I2C
2238 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2239 provides the following compelling advantages:
2241 - more than one i2c adapter is usable
2242 - approved multibus support
2243 - better i2c mux support
2245 ** Please consider updating your I2C driver now. **
2247 These enable legacy I2C serial bus commands. Defining
2248 CONFIG_HARD_I2C will include the appropriate I2C driver
2249 for the selected CPU.
2251 This will allow you to use i2c commands at the u-boot
2252 command line (as long as you set CONFIG_CMD_I2C in
2253 CONFIG_COMMANDS) and communicate with i2c based realtime
2254 clock chips. See common/cmd_i2c.c for a description of the
2255 command line interface.
2257 CONFIG_HARD_I2C selects a hardware I2C controller.
2259 There are several other quantities that must also be
2260 defined when you define CONFIG_HARD_I2C.
2262 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2263 to be the frequency (in Hz) at which you wish your i2c bus
2264 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2265 the CPU's i2c node address).
2267 Now, the u-boot i2c code for the mpc8xx
2268 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2269 and so its address should therefore be cleared to 0 (See,
2270 eg, MPC823e User's Manual p.16-473). So, set
2271 CONFIG_SYS_I2C_SLAVE to 0.
2273 CONFIG_SYS_I2C_INIT_MPC5XXX
2275 When a board is reset during an i2c bus transfer
2276 chips might think that the current transfer is still
2277 in progress. Reset the slave devices by sending start
2278 commands until the slave device responds.
2280 That's all that's required for CONFIG_HARD_I2C.
2282 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2283 then the following macros need to be defined (examples are
2284 from include/configs/lwmon.h):
2288 (Optional). Any commands necessary to enable the I2C
2289 controller or configure ports.
2291 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2295 (Only for MPC8260 CPU). The I/O port to use (the code
2296 assumes both bits are on the same port). Valid values
2297 are 0..3 for ports A..D.
2301 The code necessary to make the I2C data line active
2302 (driven). If the data line is open collector, this
2305 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2309 The code necessary to make the I2C data line tri-stated
2310 (inactive). If the data line is open collector, this
2313 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2317 Code that returns true if the I2C data line is high,
2320 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2324 If <bit> is true, sets the I2C data line high. If it
2325 is false, it clears it (low).
2327 eg: #define I2C_SDA(bit) \
2328 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2329 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2333 If <bit> is true, sets the I2C clock line high. If it
2334 is false, it clears it (low).
2336 eg: #define I2C_SCL(bit) \
2337 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2338 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2342 This delay is invoked four times per clock cycle so this
2343 controls the rate of data transfer. The data rate thus
2344 is 1 / (I2C_DELAY * 4). Often defined to be something
2347 #define I2C_DELAY udelay(2)
2349 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2351 If your arch supports the generic GPIO framework (asm/gpio.h),
2352 then you may alternatively define the two GPIOs that are to be
2353 used as SCL / SDA. Any of the previous I2C_xxx macros will
2354 have GPIO-based defaults assigned to them as appropriate.
2356 You should define these to the GPIO value as given directly to
2357 the generic GPIO functions.
2359 CONFIG_SYS_I2C_INIT_BOARD
2361 When a board is reset during an i2c bus transfer
2362 chips might think that the current transfer is still
2363 in progress. On some boards it is possible to access
2364 the i2c SCLK line directly, either by using the
2365 processor pin as a GPIO or by having a second pin
2366 connected to the bus. If this option is defined a
2367 custom i2c_init_board() routine in boards/xxx/board.c
2368 is run early in the boot sequence.
2370 CONFIG_SYS_I2C_BOARD_LATE_INIT
2372 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2373 defined a custom i2c_board_late_init() routine in
2374 boards/xxx/board.c is run AFTER the operations in i2c_init()
2375 is completed. This callpoint can be used to unreset i2c bus
2376 using CPU i2c controller register accesses for CPUs whose i2c
2377 controller provide such a method. It is called at the end of
2378 i2c_init() to allow i2c_init operations to setup the i2c bus
2379 controller on the CPU (e.g. setting bus speed & slave address).
2381 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2383 This option enables configuration of bi_iic_fast[] flags
2384 in u-boot bd_info structure based on u-boot environment
2385 variable "i2cfast". (see also i2cfast)
2387 CONFIG_I2C_MULTI_BUS
2389 This option allows the use of multiple I2C buses, each of which
2390 must have a controller. At any point in time, only one bus is
2391 active. To switch to a different bus, use the 'i2c dev' command.
2392 Note that bus numbering is zero-based.
2394 CONFIG_SYS_I2C_NOPROBES
2396 This option specifies a list of I2C devices that will be skipped
2397 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2398 is set, specify a list of bus-device pairs. Otherwise, specify
2399 a 1D array of device addresses
2402 #undef CONFIG_I2C_MULTI_BUS
2403 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2405 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2407 #define CONFIG_I2C_MULTI_BUS
2408 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2410 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2412 CONFIG_SYS_SPD_BUS_NUM
2414 If defined, then this indicates the I2C bus number for DDR SPD.
2415 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2417 CONFIG_SYS_RTC_BUS_NUM
2419 If defined, then this indicates the I2C bus number for the RTC.
2420 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2422 CONFIG_SYS_DTT_BUS_NUM
2424 If defined, then this indicates the I2C bus number for the DTT.
2425 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2427 CONFIG_SYS_I2C_DTT_ADDR:
2429 If defined, specifies the I2C address of the DTT device.
2430 If not defined, then U-Boot uses predefined value for
2431 specified DTT device.
2433 CONFIG_SOFT_I2C_READ_REPEATED_START
2435 defining this will force the i2c_read() function in
2436 the soft_i2c driver to perform an I2C repeated start
2437 between writing the address pointer and reading the
2438 data. If this define is omitted the default behaviour
2439 of doing a stop-start sequence will be used. Most I2C
2440 devices can use either method, but some require one or
2443 - SPI Support: CONFIG_SPI
2445 Enables SPI driver (so far only tested with
2446 SPI EEPROM, also an instance works with Crystal A/D and
2447 D/As on the SACSng board)
2451 Enables the driver for SPI controller on SuperH. Currently
2452 only SH7757 is supported.
2456 Enables extended (16-bit) SPI EEPROM addressing.
2457 (symmetrical to CONFIG_I2C_X)
2461 Enables a software (bit-bang) SPI driver rather than
2462 using hardware support. This is a general purpose
2463 driver that only requires three general I/O port pins
2464 (two outputs, one input) to function. If this is
2465 defined, the board configuration must define several
2466 SPI configuration items (port pins to use, etc). For
2467 an example, see include/configs/sacsng.h.
2471 Enables a hardware SPI driver for general-purpose reads
2472 and writes. As with CONFIG_SOFT_SPI, the board configuration
2473 must define a list of chip-select function pointers.
2474 Currently supported on some MPC8xxx processors. For an
2475 example, see include/configs/mpc8349emds.h.
2479 Enables the driver for the SPI controllers on i.MX and MXC
2480 SoCs. Currently i.MX31/35/51 are supported.
2482 - FPGA Support: CONFIG_FPGA
2484 Enables FPGA subsystem.
2486 CONFIG_FPGA_<vendor>
2488 Enables support for specific chip vendors.
2491 CONFIG_FPGA_<family>
2493 Enables support for FPGA family.
2494 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2498 Specify the number of FPGA devices to support.
2500 CONFIG_SYS_FPGA_PROG_FEEDBACK
2502 Enable printing of hash marks during FPGA configuration.
2504 CONFIG_SYS_FPGA_CHECK_BUSY
2506 Enable checks on FPGA configuration interface busy
2507 status by the configuration function. This option
2508 will require a board or device specific function to
2513 If defined, a function that provides delays in the FPGA
2514 configuration driver.
2516 CONFIG_SYS_FPGA_CHECK_CTRLC
2517 Allow Control-C to interrupt FPGA configuration
2519 CONFIG_SYS_FPGA_CHECK_ERROR
2521 Check for configuration errors during FPGA bitfile
2522 loading. For example, abort during Virtex II
2523 configuration if the INIT_B line goes low (which
2524 indicated a CRC error).
2526 CONFIG_SYS_FPGA_WAIT_INIT
2528 Maximum time to wait for the INIT_B line to deassert
2529 after PROB_B has been deasserted during a Virtex II
2530 FPGA configuration sequence. The default time is 500
2533 CONFIG_SYS_FPGA_WAIT_BUSY
2535 Maximum time to wait for BUSY to deassert during
2536 Virtex II FPGA configuration. The default is 5 ms.
2538 CONFIG_SYS_FPGA_WAIT_CONFIG
2540 Time to wait after FPGA configuration. The default is
2543 - Configuration Management:
2546 If defined, this string will be added to the U-Boot
2547 version information (U_BOOT_VERSION)
2549 - Vendor Parameter Protection:
2551 U-Boot considers the values of the environment
2552 variables "serial#" (Board Serial Number) and
2553 "ethaddr" (Ethernet Address) to be parameters that
2554 are set once by the board vendor / manufacturer, and
2555 protects these variables from casual modification by
2556 the user. Once set, these variables are read-only,
2557 and write or delete attempts are rejected. You can
2558 change this behaviour:
2560 If CONFIG_ENV_OVERWRITE is #defined in your config
2561 file, the write protection for vendor parameters is
2562 completely disabled. Anybody can change or delete
2565 Alternatively, if you #define _both_ CONFIG_ETHADDR
2566 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2567 Ethernet address is installed in the environment,
2568 which can be changed exactly ONCE by the user. [The
2569 serial# is unaffected by this, i. e. it remains
2572 The same can be accomplished in a more flexible way
2573 for any variable by configuring the type of access
2574 to allow for those variables in the ".flags" variable
2575 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2580 Define this variable to enable the reservation of
2581 "protected RAM", i. e. RAM which is not overwritten
2582 by U-Boot. Define CONFIG_PRAM to hold the number of
2583 kB you want to reserve for pRAM. You can overwrite
2584 this default value by defining an environment
2585 variable "pram" to the number of kB you want to
2586 reserve. Note that the board info structure will
2587 still show the full amount of RAM. If pRAM is
2588 reserved, a new environment variable "mem" will
2589 automatically be defined to hold the amount of
2590 remaining RAM in a form that can be passed as boot
2591 argument to Linux, for instance like that:
2593 setenv bootargs ... mem=\${mem}
2596 This way you can tell Linux not to use this memory,
2597 either, which results in a memory region that will
2598 not be affected by reboots.
2600 *WARNING* If your board configuration uses automatic
2601 detection of the RAM size, you must make sure that
2602 this memory test is non-destructive. So far, the
2603 following board configurations are known to be
2606 IVMS8, IVML24, SPD8xx, TQM8xxL,
2607 HERMES, IP860, RPXlite, LWMON,
2610 - Access to physical memory region (> 4GB)
2611 Some basic support is provided for operations on memory not
2612 normally accessible to U-Boot - e.g. some architectures
2613 support access to more than 4GB of memory on 32-bit
2614 machines using physical address extension or similar.
2615 Define CONFIG_PHYSMEM to access this basic support, which
2616 currently only supports clearing the memory.
2621 Define this variable to stop the system in case of a
2622 fatal error, so that you have to reset it manually.
2623 This is probably NOT a good idea for an embedded
2624 system where you want the system to reboot
2625 automatically as fast as possible, but it may be
2626 useful during development since you can try to debug
2627 the conditions that lead to the situation.
2629 CONFIG_NET_RETRY_COUNT
2631 This variable defines the number of retries for
2632 network operations like ARP, RARP, TFTP, or BOOTP
2633 before giving up the operation. If not defined, a
2634 default value of 5 is used.
2638 Timeout waiting for an ARP reply in milliseconds.
2642 Timeout in milliseconds used in NFS protocol.
2643 If you encounter "ERROR: Cannot umount" in nfs command,
2644 try longer timeout such as
2645 #define CONFIG_NFS_TIMEOUT 10000UL
2647 - Command Interpreter:
2648 CONFIG_AUTO_COMPLETE
2650 Enable auto completion of commands using TAB.
2652 Note that this feature has NOT been implemented yet
2653 for the "hush" shell.
2656 CONFIG_SYS_HUSH_PARSER
2658 Define this variable to enable the "hush" shell (from
2659 Busybox) as command line interpreter, thus enabling
2660 powerful command line syntax like
2661 if...then...else...fi conditionals or `&&' and '||'
2662 constructs ("shell scripts").
2664 If undefined, you get the old, much simpler behaviour
2665 with a somewhat smaller memory footprint.
2668 CONFIG_SYS_PROMPT_HUSH_PS2
2670 This defines the secondary prompt string, which is
2671 printed when the command interpreter needs more input
2672 to complete a command. Usually "> ".
2676 In the current implementation, the local variables
2677 space and global environment variables space are
2678 separated. Local variables are those you define by
2679 simply typing `name=value'. To access a local
2680 variable later on, you have write `$name' or
2681 `${name}'; to execute the contents of a variable
2682 directly type `$name' at the command prompt.
2684 Global environment variables are those you use
2685 setenv/printenv to work with. To run a command stored
2686 in such a variable, you need to use the run command,
2687 and you must not use the '$' sign to access them.
2689 To store commands and special characters in a
2690 variable, please use double quotation marks
2691 surrounding the whole text of the variable, instead
2692 of the backslashes before semicolons and special
2695 - Commandline Editing and History:
2696 CONFIG_CMDLINE_EDITING
2698 Enable editing and History functions for interactive
2699 commandline input operations
2701 - Default Environment:
2702 CONFIG_EXTRA_ENV_SETTINGS
2704 Define this to contain any number of null terminated
2705 strings (variable = value pairs) that will be part of
2706 the default environment compiled into the boot image.
2708 For example, place something like this in your
2709 board's config file:
2711 #define CONFIG_EXTRA_ENV_SETTINGS \
2715 Warning: This method is based on knowledge about the
2716 internal format how the environment is stored by the
2717 U-Boot code. This is NOT an official, exported
2718 interface! Although it is unlikely that this format
2719 will change soon, there is no guarantee either.
2720 You better know what you are doing here.
2722 Note: overly (ab)use of the default environment is
2723 discouraged. Make sure to check other ways to preset
2724 the environment like the "source" command or the
2727 CONFIG_ENV_VARS_UBOOT_CONFIG
2729 Define this in order to add variables describing the
2730 U-Boot build configuration to the default environment.
2731 These will be named arch, cpu, board, vendor, and soc.
2733 Enabling this option will cause the following to be defined:
2741 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2743 Define this in order to add variables describing certain
2744 run-time determined information about the hardware to the
2745 environment. These will be named board_name, board_rev.
2747 CONFIG_DELAY_ENVIRONMENT
2749 Normally the environment is loaded when the board is
2750 intialised so that it is available to U-Boot. This inhibits
2751 that so that the environment is not available until
2752 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2753 this is instead controlled by the value of
2754 /config/load-environment.
2756 - DataFlash Support:
2757 CONFIG_HAS_DATAFLASH
2759 Defining this option enables DataFlash features and
2760 allows to read/write in Dataflash via the standard
2763 - Serial Flash support
2766 Defining this option enables SPI flash commands
2767 'sf probe/read/write/erase/update'.
2769 Usage requires an initial 'probe' to define the serial
2770 flash parameters, followed by read/write/erase/update
2773 The following defaults may be provided by the platform
2774 to handle the common case when only a single serial
2775 flash is present on the system.
2777 CONFIG_SF_DEFAULT_BUS Bus identifier
2778 CONFIG_SF_DEFAULT_CS Chip-select
2779 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2780 CONFIG_SF_DEFAULT_SPEED in Hz
2784 Define this option to include a destructive SPI flash
2787 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2789 Define this option to use the Bank addr/Extended addr
2790 support on SPI flashes which has size > 16Mbytes.
2792 CONFIG_SF_DUAL_FLASH Dual flash memories
2794 Define this option to use dual flash support where two flash
2795 memories can be connected with a given cs line.
2796 currently Xilinx Zynq qspi support these type of connections.
2798 - SystemACE Support:
2801 Adding this option adds support for Xilinx SystemACE
2802 chips attached via some sort of local bus. The address
2803 of the chip must also be defined in the
2804 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2806 #define CONFIG_SYSTEMACE
2807 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2809 When SystemACE support is added, the "ace" device type
2810 becomes available to the fat commands, i.e. fatls.
2812 - TFTP Fixed UDP Port:
2815 If this is defined, the environment variable tftpsrcp
2816 is used to supply the TFTP UDP source port value.
2817 If tftpsrcp isn't defined, the normal pseudo-random port
2818 number generator is used.
2820 Also, the environment variable tftpdstp is used to supply
2821 the TFTP UDP destination port value. If tftpdstp isn't
2822 defined, the normal port 69 is used.
2824 The purpose for tftpsrcp is to allow a TFTP server to
2825 blindly start the TFTP transfer using the pre-configured
2826 target IP address and UDP port. This has the effect of
2827 "punching through" the (Windows XP) firewall, allowing
2828 the remainder of the TFTP transfer to proceed normally.
2829 A better solution is to properly configure the firewall,
2830 but sometimes that is not allowed.
2835 This enables a generic 'hash' command which can produce
2836 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2840 Enable the hash verify command (hash -v). This adds to code
2843 CONFIG_SHA1 - support SHA1 hashing
2844 CONFIG_SHA256 - support SHA256 hashing
2846 Note: There is also a sha1sum command, which should perhaps
2847 be deprecated in favour of 'hash sha1'.
2849 - Freescale i.MX specific commands:
2850 CONFIG_CMD_HDMIDETECT
2851 This enables 'hdmidet' command which returns true if an
2852 HDMI monitor is detected. This command is i.MX 6 specific.
2855 This enables the 'bmode' (bootmode) command for forcing
2856 a boot from specific media.
2858 This is useful for forcing the ROM's usb downloader to
2859 activate upon a watchdog reset which is nice when iterating
2860 on U-Boot. Using the reset button or running bmode normal
2861 will set it back to normal. This command currently
2862 supports i.MX53 and i.MX6.
2867 This enables the RSA algorithm used for FIT image verification
2868 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2870 The signing part is build into mkimage regardless of this
2873 - bootcount support:
2874 CONFIG_BOOTCOUNT_LIMIT
2876 This enables the bootcounter support, see:
2877 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2880 enable special bootcounter support on at91sam9xe based boards.
2882 enable special bootcounter support on blackfin based boards.
2884 enable special bootcounter support on da850 based boards.
2885 CONFIG_BOOTCOUNT_RAM
2886 enable support for the bootcounter in RAM
2887 CONFIG_BOOTCOUNT_I2C
2888 enable support for the bootcounter on an i2c (like RTC) device.
2889 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2890 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2892 CONFIG_BOOTCOUNT_ALEN = address len
2894 - Show boot progress:
2895 CONFIG_SHOW_BOOT_PROGRESS
2897 Defining this option allows to add some board-
2898 specific code (calling a user-provided function
2899 "show_boot_progress(int)") that enables you to show
2900 the system's boot progress on some display (for
2901 example, some LED's) on your board. At the moment,
2902 the following checkpoints are implemented:
2904 - Detailed boot stage timing
2906 Define this option to get detailed timing of each stage
2907 of the boot process.
2909 CONFIG_BOOTSTAGE_USER_COUNT
2910 This is the number of available user bootstage records.
2911 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2912 a new ID will be allocated from this stash. If you exceed
2913 the limit, recording will stop.
2915 CONFIG_BOOTSTAGE_REPORT
2916 Define this to print a report before boot, similar to this:
2918 Timer summary in microseconds:
2921 3,575,678 3,575,678 board_init_f start
2922 3,575,695 17 arch_cpu_init A9
2923 3,575,777 82 arch_cpu_init done
2924 3,659,598 83,821 board_init_r start
2925 3,910,375 250,777 main_loop
2926 29,916,167 26,005,792 bootm_start
2927 30,361,327 445,160 start_kernel
2929 CONFIG_CMD_BOOTSTAGE
2930 Add a 'bootstage' command which supports printing a report
2931 and un/stashing of bootstage data.
2933 CONFIG_BOOTSTAGE_FDT
2934 Stash the bootstage information in the FDT. A root 'bootstage'
2935 node is created with each bootstage id as a child. Each child
2936 has a 'name' property and either 'mark' containing the
2937 mark time in microsecond, or 'accum' containing the
2938 accumulated time for that bootstage id in microseconds.
2943 name = "board_init_f";
2952 Code in the Linux kernel can find this in /proc/devicetree.
2954 Legacy uImage format:
2957 1 common/cmd_bootm.c before attempting to boot an image
2958 -1 common/cmd_bootm.c Image header has bad magic number
2959 2 common/cmd_bootm.c Image header has correct magic number
2960 -2 common/cmd_bootm.c Image header has bad checksum
2961 3 common/cmd_bootm.c Image header has correct checksum
2962 -3 common/cmd_bootm.c Image data has bad checksum
2963 4 common/cmd_bootm.c Image data has correct checksum
2964 -4 common/cmd_bootm.c Image is for unsupported architecture
2965 5 common/cmd_bootm.c Architecture check OK
2966 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2967 6 common/cmd_bootm.c Image Type check OK
2968 -6 common/cmd_bootm.c gunzip uncompression error
2969 -7 common/cmd_bootm.c Unimplemented compression type
2970 7 common/cmd_bootm.c Uncompression OK
2971 8 common/cmd_bootm.c No uncompress/copy overwrite error
2972 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2974 9 common/image.c Start initial ramdisk verification
2975 -10 common/image.c Ramdisk header has bad magic number
2976 -11 common/image.c Ramdisk header has bad checksum
2977 10 common/image.c Ramdisk header is OK
2978 -12 common/image.c Ramdisk data has bad checksum
2979 11 common/image.c Ramdisk data has correct checksum
2980 12 common/image.c Ramdisk verification complete, start loading
2981 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2982 13 common/image.c Start multifile image verification
2983 14 common/image.c No initial ramdisk, no multifile, continue.
2985 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2987 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2988 -31 post/post.c POST test failed, detected by post_output_backlog()
2989 -32 post/post.c POST test failed, detected by post_run_single()
2991 34 common/cmd_doc.c before loading a Image from a DOC device
2992 -35 common/cmd_doc.c Bad usage of "doc" command
2993 35 common/cmd_doc.c correct usage of "doc" command
2994 -36 common/cmd_doc.c No boot device
2995 36 common/cmd_doc.c correct boot device
2996 -37 common/cmd_doc.c Unknown Chip ID on boot device
2997 37 common/cmd_doc.c correct chip ID found, device available
2998 -38 common/cmd_doc.c Read Error on boot device
2999 38 common/cmd_doc.c reading Image header from DOC device OK
3000 -39 common/cmd_doc.c Image header has bad magic number
3001 39 common/cmd_doc.c Image header has correct magic number
3002 -40 common/cmd_doc.c Error reading Image from DOC device
3003 40 common/cmd_doc.c Image header has correct magic number
3004 41 common/cmd_ide.c before loading a Image from a IDE device
3005 -42 common/cmd_ide.c Bad usage of "ide" command
3006 42 common/cmd_ide.c correct usage of "ide" command
3007 -43 common/cmd_ide.c No boot device
3008 43 common/cmd_ide.c boot device found
3009 -44 common/cmd_ide.c Device not available
3010 44 common/cmd_ide.c Device available
3011 -45 common/cmd_ide.c wrong partition selected
3012 45 common/cmd_ide.c partition selected
3013 -46 common/cmd_ide.c Unknown partition table
3014 46 common/cmd_ide.c valid partition table found
3015 -47 common/cmd_ide.c Invalid partition type
3016 47 common/cmd_ide.c correct partition type
3017 -48 common/cmd_ide.c Error reading Image Header on boot device
3018 48 common/cmd_ide.c reading Image Header from IDE device OK
3019 -49 common/cmd_ide.c Image header has bad magic number
3020 49 common/cmd_ide.c Image header has correct magic number
3021 -50 common/cmd_ide.c Image header has bad checksum
3022 50 common/cmd_ide.c Image header has correct checksum
3023 -51 common/cmd_ide.c Error reading Image from IDE device
3024 51 common/cmd_ide.c reading Image from IDE device OK
3025 52 common/cmd_nand.c before loading a Image from a NAND device
3026 -53 common/cmd_nand.c Bad usage of "nand" command
3027 53 common/cmd_nand.c correct usage of "nand" command
3028 -54 common/cmd_nand.c No boot device
3029 54 common/cmd_nand.c boot device found
3030 -55 common/cmd_nand.c Unknown Chip ID on boot device
3031 55 common/cmd_nand.c correct chip ID found, device available
3032 -56 common/cmd_nand.c Error reading Image Header on boot device
3033 56 common/cmd_nand.c reading Image Header from NAND device OK
3034 -57 common/cmd_nand.c Image header has bad magic number
3035 57 common/cmd_nand.c Image header has correct magic number
3036 -58 common/cmd_nand.c Error reading Image from NAND device
3037 58 common/cmd_nand.c reading Image from NAND device OK
3039 -60 common/env_common.c Environment has a bad CRC, using default
3041 64 net/eth.c starting with Ethernet configuration.
3042 -64 net/eth.c no Ethernet found.
3043 65 net/eth.c Ethernet found.
3045 -80 common/cmd_net.c usage wrong
3046 80 common/cmd_net.c before calling NetLoop()
3047 -81 common/cmd_net.c some error in NetLoop() occurred
3048 81 common/cmd_net.c NetLoop() back without error
3049 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3050 82 common/cmd_net.c trying automatic boot
3051 83 common/cmd_net.c running "source" command
3052 -83 common/cmd_net.c some error in automatic boot or "source" command
3053 84 common/cmd_net.c end without errors
3058 100 common/cmd_bootm.c Kernel FIT Image has correct format
3059 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3060 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3061 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3062 102 common/cmd_bootm.c Kernel unit name specified
3063 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3064 103 common/cmd_bootm.c Found configuration node
3065 104 common/cmd_bootm.c Got kernel subimage node offset
3066 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3067 105 common/cmd_bootm.c Kernel subimage hash verification OK
3068 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3069 106 common/cmd_bootm.c Architecture check OK
3070 -106 common/cmd_bootm.c Kernel subimage has wrong type
3071 107 common/cmd_bootm.c Kernel subimage type OK
3072 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3073 108 common/cmd_bootm.c Got kernel subimage data/size
3074 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3075 -109 common/cmd_bootm.c Can't get kernel subimage type
3076 -110 common/cmd_bootm.c Can't get kernel subimage comp
3077 -111 common/cmd_bootm.c Can't get kernel subimage os
3078 -112 common/cmd_bootm.c Can't get kernel subimage load address
3079 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3081 120 common/image.c Start initial ramdisk verification
3082 -120 common/image.c Ramdisk FIT image has incorrect format
3083 121 common/image.c Ramdisk FIT image has correct format
3084 122 common/image.c No ramdisk subimage unit name, using configuration
3085 -122 common/image.c Can't get configuration for ramdisk subimage
3086 123 common/image.c Ramdisk unit name specified
3087 -124 common/image.c Can't get ramdisk subimage node offset
3088 125 common/image.c Got ramdisk subimage node offset
3089 -125 common/image.c Ramdisk subimage hash verification failed
3090 126 common/image.c Ramdisk subimage hash verification OK
3091 -126 common/image.c Ramdisk subimage for unsupported architecture
3092 127 common/image.c Architecture check OK
3093 -127 common/image.c Can't get ramdisk subimage data/size
3094 128 common/image.c Got ramdisk subimage data/size
3095 129 common/image.c Can't get ramdisk load address
3096 -129 common/image.c Got ramdisk load address
3098 -130 common/cmd_doc.c Incorrect FIT image format
3099 131 common/cmd_doc.c FIT image format OK
3101 -140 common/cmd_ide.c Incorrect FIT image format
3102 141 common/cmd_ide.c FIT image format OK
3104 -150 common/cmd_nand.c Incorrect FIT image format
3105 151 common/cmd_nand.c FIT image format OK
3107 - FIT image support:
3109 Enable support for the FIT uImage format.
3111 CONFIG_FIT_BEST_MATCH
3112 When no configuration is explicitly selected, default to the
3113 one whose fdt's compatibility field best matches that of
3114 U-Boot itself. A match is considered "best" if it matches the
3115 most specific compatibility entry of U-Boot's fdt's root node.
3116 The order of entries in the configuration's fdt is ignored.
3118 CONFIG_FIT_SIGNATURE
3119 This option enables signature verification of FIT uImages,
3120 using a hash signed and verified using RSA. See
3121 doc/uImage.FIT/signature.txt for more details.
3123 - Standalone program support:
3124 CONFIG_STANDALONE_LOAD_ADDR
3126 This option defines a board specific value for the
3127 address where standalone program gets loaded, thus
3128 overwriting the architecture dependent default
3131 - Frame Buffer Address:
3134 Define CONFIG_FB_ADDR if you want to use specific
3135 address for frame buffer. This is typically the case
3136 when using a graphics controller has separate video
3137 memory. U-Boot will then place the frame buffer at
3138 the given address instead of dynamically reserving it
3139 in system RAM by calling lcd_setmem(), which grabs
3140 the memory for the frame buffer depending on the
3141 configured panel size.
3143 Please see board_init_f function.
3145 - Automatic software updates via TFTP server
3147 CONFIG_UPDATE_TFTP_CNT_MAX
3148 CONFIG_UPDATE_TFTP_MSEC_MAX
3150 These options enable and control the auto-update feature;
3151 for a more detailed description refer to doc/README.update.
3153 - MTD Support (mtdparts command, UBI support)
3156 Adds the MTD device infrastructure from the Linux kernel.
3157 Needed for mtdparts command support.
3159 CONFIG_MTD_PARTITIONS
3161 Adds the MTD partitioning infrastructure from the Linux
3162 kernel. Needed for UBI support.
3167 Adds commands for interacting with MTD partitions formatted
3168 with the UBI flash translation layer
3170 Requires also defining CONFIG_RBTREE
3172 CONFIG_UBI_SILENCE_MSG
3174 Make the verbose messages from UBI stop printing. This leaves
3175 warnings and errors enabled.
3180 Adds commands for interacting with UBI volumes formatted as
3181 UBIFS. UBIFS is read-only in u-boot.
3183 Requires UBI support as well as CONFIG_LZO
3185 CONFIG_UBIFS_SILENCE_MSG
3187 Make the verbose messages from UBIFS stop printing. This leaves
3188 warnings and errors enabled.
3192 Enable building of SPL globally.
3195 LDSCRIPT for linking the SPL binary.
3197 CONFIG_SPL_MAX_FOOTPRINT
3198 Maximum size in memory allocated to the SPL, BSS included.
3199 When defined, the linker checks that the actual memory
3200 used by SPL from _start to __bss_end does not exceed it.
3201 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3202 must not be both defined at the same time.
3205 Maximum size of the SPL image (text, data, rodata, and
3206 linker lists sections), BSS excluded.
3207 When defined, the linker checks that the actual size does
3210 CONFIG_SPL_TEXT_BASE
3211 TEXT_BASE for linking the SPL binary.
3213 CONFIG_SPL_RELOC_TEXT_BASE
3214 Address to relocate to. If unspecified, this is equal to
3215 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3217 CONFIG_SPL_BSS_START_ADDR
3218 Link address for the BSS within the SPL binary.
3220 CONFIG_SPL_BSS_MAX_SIZE
3221 Maximum size in memory allocated to the SPL BSS.
3222 When defined, the linker checks that the actual memory used
3223 by SPL from __bss_start to __bss_end does not exceed it.
3224 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3225 must not be both defined at the same time.
3228 Adress of the start of the stack SPL will use
3230 CONFIG_SPL_RELOC_STACK
3231 Adress of the start of the stack SPL will use after
3232 relocation. If unspecified, this is equal to
3235 CONFIG_SYS_SPL_MALLOC_START
3236 Starting address of the malloc pool used in SPL.
3238 CONFIG_SYS_SPL_MALLOC_SIZE
3239 The size of the malloc pool used in SPL.
3241 CONFIG_SPL_FRAMEWORK
3242 Enable the SPL framework under common/. This framework
3243 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3244 NAND loading of the Linux Kernel.
3246 CONFIG_SPL_DISPLAY_PRINT
3247 For ARM, enable an optional function to print more information
3248 about the running system.
3250 CONFIG_SPL_INIT_MINIMAL
3251 Arch init code should be built for a very small image
3253 CONFIG_SPL_LIBCOMMON_SUPPORT
3254 Support for common/libcommon.o in SPL binary
3256 CONFIG_SPL_LIBDISK_SUPPORT
3257 Support for disk/libdisk.o in SPL binary
3259 CONFIG_SPL_I2C_SUPPORT
3260 Support for drivers/i2c/libi2c.o in SPL binary
3262 CONFIG_SPL_GPIO_SUPPORT
3263 Support for drivers/gpio/libgpio.o in SPL binary
3265 CONFIG_SPL_MMC_SUPPORT
3266 Support for drivers/mmc/libmmc.o in SPL binary
3268 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3269 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3270 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3271 Address, size and partition on the MMC to load U-Boot from
3272 when the MMC is being used in raw mode.
3274 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3275 Sector to load kernel uImage from when MMC is being
3276 used in raw mode (for Falcon mode)
3278 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3279 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3280 Sector and number of sectors to load kernel argument
3281 parameters from when MMC is being used in raw mode
3284 CONFIG_SPL_FAT_SUPPORT
3285 Support for fs/fat/libfat.o in SPL binary
3287 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3288 Filename to read to load U-Boot when reading from FAT
3290 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3291 Filename to read to load kernel uImage when reading
3292 from FAT (for Falcon mode)
3294 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3295 Filename to read to load kernel argument parameters
3296 when reading from FAT (for Falcon mode)
3298 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3299 Set this for NAND SPL on PPC mpc83xx targets, so that
3300 start.S waits for the rest of the SPL to load before
3301 continuing (the hardware starts execution after just
3302 loading the first page rather than the full 4K).
3304 CONFIG_SPL_NAND_BASE
3305 Include nand_base.c in the SPL. Requires
3306 CONFIG_SPL_NAND_DRIVERS.
3308 CONFIG_SPL_NAND_DRIVERS
3309 SPL uses normal NAND drivers, not minimal drivers.
3312 Include standard software ECC in the SPL
3314 CONFIG_SPL_NAND_SIMPLE
3315 Support for NAND boot using simple NAND drivers that
3316 expose the cmd_ctrl() interface.
3318 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3319 Set for the SPL on PPC mpc8xxx targets, support for
3320 drivers/ddr/fsl/libddr.o in SPL binary.
3322 CONFIG_SPL_COMMON_INIT_DDR
3323 Set for common ddr init with serial presence detect in
3326 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3327 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3328 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3329 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3330 CONFIG_SYS_NAND_ECCBYTES
3331 Defines the size and behavior of the NAND that SPL uses
3334 CONFIG_SPL_NAND_BOOT
3335 Add support NAND boot
3337 CONFIG_SYS_NAND_U_BOOT_OFFS
3338 Location in NAND to read U-Boot from
3340 CONFIG_SYS_NAND_U_BOOT_DST
3341 Location in memory to load U-Boot to
3343 CONFIG_SYS_NAND_U_BOOT_SIZE
3344 Size of image to load
3346 CONFIG_SYS_NAND_U_BOOT_START
3347 Entry point in loaded image to jump to
3349 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3350 Define this if you need to first read the OOB and then the
3351 data. This is used for example on davinci plattforms.
3353 CONFIG_SPL_OMAP3_ID_NAND
3354 Support for an OMAP3-specific set of functions to return the
3355 ID and MFR of the first attached NAND chip, if present.
3357 CONFIG_SPL_SERIAL_SUPPORT
3358 Support for drivers/serial/libserial.o in SPL binary
3360 CONFIG_SPL_SPI_FLASH_SUPPORT
3361 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3363 CONFIG_SPL_SPI_SUPPORT
3364 Support for drivers/spi/libspi.o in SPL binary
3366 CONFIG_SPL_RAM_DEVICE
3367 Support for running image already present in ram, in SPL binary
3369 CONFIG_SPL_LIBGENERIC_SUPPORT
3370 Support for lib/libgeneric.o in SPL binary
3372 CONFIG_SPL_ENV_SUPPORT
3373 Support for the environment operating in SPL binary
3375 CONFIG_SPL_NET_SUPPORT
3376 Support for the net/libnet.o in SPL binary.
3377 It conflicts with SPL env from storage medium specified by
3378 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3381 Image offset to which the SPL should be padded before appending
3382 the SPL payload. By default, this is defined as
3383 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3384 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3385 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3388 Final target image containing SPL and payload. Some SPLs
3389 use an arch-specific makefile fragment instead, for
3390 example if more than one image needs to be produced.
3392 CONFIG_FIT_SPL_PRINT
3393 Printing information about a FIT image adds quite a bit of
3394 code to SPL. So this is normally disabled in SPL. Use this
3395 option to re-enable it. This will affect the output of the
3396 bootm command when booting a FIT image.
3400 Enable building of TPL globally.
3403 Image offset to which the TPL should be padded before appending
3404 the TPL payload. By default, this is defined as
3405 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3406 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3407 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3412 [so far only for SMDK2400 boards]
3414 - Modem support enable:
3415 CONFIG_MODEM_SUPPORT
3417 - RTS/CTS Flow control enable:
3420 - Modem debug support:
3421 CONFIG_MODEM_SUPPORT_DEBUG
3423 Enables debugging stuff (char screen[1024], dbg())
3424 for modem support. Useful only with BDI2000.
3426 - Interrupt support (PPC):
3428 There are common interrupt_init() and timer_interrupt()
3429 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3430 for CPU specific initialization. interrupt_init_cpu()
3431 should set decrementer_count to appropriate value. If
3432 CPU resets decrementer automatically after interrupt
3433 (ppc4xx) it should set decrementer_count to zero.
3434 timer_interrupt() calls timer_interrupt_cpu() for CPU
3435 specific handling. If board has watchdog / status_led
3436 / other_activity_monitor it works automatically from
3437 general timer_interrupt().
3441 In the target system modem support is enabled when a
3442 specific key (key combination) is pressed during
3443 power-on. Otherwise U-Boot will boot normally
3444 (autoboot). The key_pressed() function is called from
3445 board_init(). Currently key_pressed() is a dummy
3446 function, returning 1 and thus enabling modem
3449 If there are no modem init strings in the
3450 environment, U-Boot proceed to autoboot; the
3451 previous output (banner, info printfs) will be
3454 See also: doc/README.Modem
3456 Board initialization settings:
3457 ------------------------------
3459 During Initialization u-boot calls a number of board specific functions
3460 to allow the preparation of board specific prerequisites, e.g. pin setup
3461 before drivers are initialized. To enable these callbacks the
3462 following configuration macros have to be defined. Currently this is
3463 architecture specific, so please check arch/your_architecture/lib/board.c
3464 typically in board_init_f() and board_init_r().
3466 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3467 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3468 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3469 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3471 Configuration Settings:
3472 -----------------------
3474 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3475 Optionally it can be defined to support 64-bit memory commands.
3477 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3478 undefine this when you're short of memory.
3480 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3481 width of the commands listed in the 'help' command output.
3483 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3484 prompt for user input.
3486 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3488 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3490 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3492 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3493 the application (usually a Linux kernel) when it is
3496 - CONFIG_SYS_BAUDRATE_TABLE:
3497 List of legal baudrate settings for this board.
3499 - CONFIG_SYS_CONSOLE_INFO_QUIET
3500 Suppress display of console information at boot.
3502 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3503 If the board specific function
3504 extern int overwrite_console (void);
3505 returns 1, the stdin, stderr and stdout are switched to the
3506 serial port, else the settings in the environment are used.
3508 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3509 Enable the call to overwrite_console().
3511 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3512 Enable overwrite of previous console environment settings.
3514 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3515 Begin and End addresses of the area used by the
3518 - CONFIG_SYS_ALT_MEMTEST:
3519 Enable an alternate, more extensive memory test.
3521 - CONFIG_SYS_MEMTEST_SCRATCH:
3522 Scratch address used by the alternate memory test
3523 You only need to set this if address zero isn't writeable
3525 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3526 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3527 this specified memory area will get subtracted from the top
3528 (end) of RAM and won't get "touched" at all by U-Boot. By
3529 fixing up gd->ram_size the Linux kernel should gets passed
3530 the now "corrected" memory size and won't touch it either.
3531 This should work for arch/ppc and arch/powerpc. Only Linux
3532 board ports in arch/powerpc with bootwrapper support that
3533 recalculate the memory size from the SDRAM controller setup
3534 will have to get fixed in Linux additionally.
3536 This option can be used as a workaround for the 440EPx/GRx
3537 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3540 WARNING: Please make sure that this value is a multiple of
3541 the Linux page size (normally 4k). If this is not the case,
3542 then the end address of the Linux memory will be located at a
3543 non page size aligned address and this could cause major
3546 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3547 Enable temporary baudrate change while serial download
3549 - CONFIG_SYS_SDRAM_BASE:
3550 Physical start address of SDRAM. _Must_ be 0 here.
3552 - CONFIG_SYS_MBIO_BASE:
3553 Physical start address of Motherboard I/O (if using a
3556 - CONFIG_SYS_FLASH_BASE:
3557 Physical start address of Flash memory.
3559 - CONFIG_SYS_MONITOR_BASE:
3560 Physical start address of boot monitor code (set by
3561 make config files to be same as the text base address
3562 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3563 CONFIG_SYS_FLASH_BASE when booting from flash.
3565 - CONFIG_SYS_MONITOR_LEN:
3566 Size of memory reserved for monitor code, used to
3567 determine _at_compile_time_ (!) if the environment is
3568 embedded within the U-Boot image, or in a separate
3571 - CONFIG_SYS_MALLOC_LEN:
3572 Size of DRAM reserved for malloc() use.
3574 - CONFIG_SYS_BOOTM_LEN:
3575 Normally compressed uImages are limited to an
3576 uncompressed size of 8 MBytes. If this is not enough,
3577 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3578 to adjust this setting to your needs.
3580 - CONFIG_SYS_BOOTMAPSZ:
3581 Maximum size of memory mapped by the startup code of
3582 the Linux kernel; all data that must be processed by
3583 the Linux kernel (bd_info, boot arguments, FDT blob if
3584 used) must be put below this limit, unless "bootm_low"
3585 environment variable is defined and non-zero. In such case
3586 all data for the Linux kernel must be between "bootm_low"
3587 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3588 variable "bootm_mapsize" will override the value of
3589 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3590 then the value in "bootm_size" will be used instead.
3592 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3593 Enable initrd_high functionality. If defined then the
3594 initrd_high feature is enabled and the bootm ramdisk subcommand
3597 - CONFIG_SYS_BOOT_GET_CMDLINE:
3598 Enables allocating and saving kernel cmdline in space between
3599 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3601 - CONFIG_SYS_BOOT_GET_KBD:
3602 Enables allocating and saving a kernel copy of the bd_info in
3603 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3605 - CONFIG_SYS_MAX_FLASH_BANKS:
3606 Max number of Flash memory banks
3608 - CONFIG_SYS_MAX_FLASH_SECT:
3609 Max number of sectors on a Flash chip
3611 - CONFIG_SYS_FLASH_ERASE_TOUT:
3612 Timeout for Flash erase operations (in ms)
3614 - CONFIG_SYS_FLASH_WRITE_TOUT:
3615 Timeout for Flash write operations (in ms)
3617 - CONFIG_SYS_FLASH_LOCK_TOUT
3618 Timeout for Flash set sector lock bit operation (in ms)
3620 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3621 Timeout for Flash clear lock bits operation (in ms)
3623 - CONFIG_SYS_FLASH_PROTECTION
3624 If defined, hardware flash sectors protection is used
3625 instead of U-Boot software protection.
3627 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3629 Enable TFTP transfers directly to flash memory;
3630 without this option such a download has to be
3631 performed in two steps: (1) download to RAM, and (2)
3632 copy from RAM to flash.
3634 The two-step approach is usually more reliable, since
3635 you can check if the download worked before you erase
3636 the flash, but in some situations (when system RAM is
3637 too limited to allow for a temporary copy of the
3638 downloaded image) this option may be very useful.
3640 - CONFIG_SYS_FLASH_CFI:
3641 Define if the flash driver uses extra elements in the
3642 common flash structure for storing flash geometry.
3644 - CONFIG_FLASH_CFI_DRIVER
3645 This option also enables the building of the cfi_flash driver
3646 in the drivers directory
3648 - CONFIG_FLASH_CFI_MTD
3649 This option enables the building of the cfi_mtd driver
3650 in the drivers directory. The driver exports CFI flash
3653 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3654 Use buffered writes to flash.
3656 - CONFIG_FLASH_SPANSION_S29WS_N
3657 s29ws-n MirrorBit flash has non-standard addresses for buffered
3660 - CONFIG_SYS_FLASH_QUIET_TEST
3661 If this option is defined, the common CFI flash doesn't
3662 print it's warning upon not recognized FLASH banks. This
3663 is useful, if some of the configured banks are only
3664 optionally available.
3666 - CONFIG_FLASH_SHOW_PROGRESS
3667 If defined (must be an integer), print out countdown
3668 digits and dots. Recommended value: 45 (9..1) for 80
3669 column displays, 15 (3..1) for 40 column displays.
3671 - CONFIG_FLASH_VERIFY
3672 If defined, the content of the flash (destination) is compared
3673 against the source after the write operation. An error message
3674 will be printed when the contents are not identical.
3675 Please note that this option is useless in nearly all cases,
3676 since such flash programming errors usually are detected earlier
3677 while unprotecting/erasing/programming. Please only enable
3678 this option if you really know what you are doing.
3680 - CONFIG_SYS_RX_ETH_BUFFER:
3681 Defines the number of Ethernet receive buffers. On some
3682 Ethernet controllers it is recommended to set this value
3683 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3684 buffers can be full shortly after enabling the interface
3685 on high Ethernet traffic.
3686 Defaults to 4 if not defined.
3688 - CONFIG_ENV_MAX_ENTRIES
3690 Maximum number of entries in the hash table that is used
3691 internally to store the environment settings. The default
3692 setting is supposed to be generous and should work in most
3693 cases. This setting can be used to tune behaviour; see
3694 lib/hashtable.c for details.
3696 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3697 - CONFIG_ENV_FLAGS_LIST_STATIC
3698 Enable validation of the values given to environment variables when
3699 calling env set. Variables can be restricted to only decimal,
3700 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3701 the variables can also be restricted to IP address or MAC address.
3703 The format of the list is:
3704 type_attribute = [s|d|x|b|i|m]
3705 access_atribute = [a|r|o|c]
3706 attributes = type_attribute[access_atribute]
3707 entry = variable_name[:attributes]
3710 The type attributes are:
3711 s - String (default)
3714 b - Boolean ([1yYtT|0nNfF])
3718 The access attributes are:
3724 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3725 Define this to a list (string) to define the ".flags"
3726 envirnoment variable in the default or embedded environment.
3728 - CONFIG_ENV_FLAGS_LIST_STATIC
3729 Define this to a list (string) to define validation that
3730 should be done if an entry is not found in the ".flags"
3731 environment variable. To override a setting in the static
3732 list, simply add an entry for the same variable name to the
3735 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3736 If defined, don't allow the -f switch to env set override variable
3739 - CONFIG_SYS_GENERIC_BOARD
3740 This selects the architecture-generic board system instead of the
3741 architecture-specific board files. It is intended to move boards
3742 to this new framework over time. Defining this will disable the
3743 arch/foo/lib/board.c file and use common/board_f.c and
3744 common/board_r.c instead. To use this option your architecture
3745 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3746 its config.mk file). If you find problems enabling this option on
3747 your board please report the problem and send patches!
3749 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3750 This is set by OMAP boards for the max time that reset should
3751 be asserted. See doc/README.omap-reset-time for details on how
3752 the value can be calulated on a given board.
3754 The following definitions that deal with the placement and management
3755 of environment data (variable area); in general, we support the
3756 following configurations:
3758 - CONFIG_BUILD_ENVCRC:
3760 Builds up envcrc with the target environment so that external utils
3761 may easily extract it and embed it in final U-Boot images.
3763 - CONFIG_ENV_IS_IN_FLASH:
3765 Define this if the environment is in flash memory.
3767 a) The environment occupies one whole flash sector, which is
3768 "embedded" in the text segment with the U-Boot code. This
3769 happens usually with "bottom boot sector" or "top boot
3770 sector" type flash chips, which have several smaller
3771 sectors at the start or the end. For instance, such a
3772 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3773 such a case you would place the environment in one of the
3774 4 kB sectors - with U-Boot code before and after it. With
3775 "top boot sector" type flash chips, you would put the
3776 environment in one of the last sectors, leaving a gap
3777 between U-Boot and the environment.
3779 - CONFIG_ENV_OFFSET:
3781 Offset of environment data (variable area) to the
3782 beginning of flash memory; for instance, with bottom boot
3783 type flash chips the second sector can be used: the offset
3784 for this sector is given here.
3786 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3790 This is just another way to specify the start address of
3791 the flash sector containing the environment (instead of
3794 - CONFIG_ENV_SECT_SIZE:
3796 Size of the sector containing the environment.
3799 b) Sometimes flash chips have few, equal sized, BIG sectors.
3800 In such a case you don't want to spend a whole sector for
3805 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3806 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3807 of this flash sector for the environment. This saves
3808 memory for the RAM copy of the environment.
3810 It may also save flash memory if you decide to use this
3811 when your environment is "embedded" within U-Boot code,
3812 since then the remainder of the flash sector could be used
3813 for U-Boot code. It should be pointed out that this is
3814 STRONGLY DISCOURAGED from a robustness point of view:
3815 updating the environment in flash makes it always
3816 necessary to erase the WHOLE sector. If something goes
3817 wrong before the contents has been restored from a copy in
3818 RAM, your target system will be dead.
3820 - CONFIG_ENV_ADDR_REDUND
3821 CONFIG_ENV_SIZE_REDUND
3823 These settings describe a second storage area used to hold
3824 a redundant copy of the environment data, so that there is
3825 a valid backup copy in case there is a power failure during
3826 a "saveenv" operation.
3828 BE CAREFUL! Any changes to the flash layout, and some changes to the
3829 source code will make it necessary to adapt <board>/u-boot.lds*
3833 - CONFIG_ENV_IS_IN_NVRAM:
3835 Define this if you have some non-volatile memory device
3836 (NVRAM, battery buffered SRAM) which you want to use for the
3842 These two #defines are used to determine the memory area you
3843 want to use for environment. It is assumed that this memory
3844 can just be read and written to, without any special
3847 BE CAREFUL! The first access to the environment happens quite early
3848 in U-Boot initalization (when we try to get the setting of for the
3849 console baudrate). You *MUST* have mapped your NVRAM area then, or
3852 Please note that even with NVRAM we still use a copy of the
3853 environment in RAM: we could work on NVRAM directly, but we want to
3854 keep settings there always unmodified except somebody uses "saveenv"
3855 to save the current settings.
3858 - CONFIG_ENV_IS_IN_EEPROM:
3860 Use this if you have an EEPROM or similar serial access
3861 device and a driver for it.
3863 - CONFIG_ENV_OFFSET:
3866 These two #defines specify the offset and size of the
3867 environment area within the total memory of your EEPROM.
3869 - CONFIG_SYS_I2C_EEPROM_ADDR:
3870 If defined, specified the chip address of the EEPROM device.
3871 The default address is zero.
3873 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3874 If defined, the number of bits used to address bytes in a
3875 single page in the EEPROM device. A 64 byte page, for example
3876 would require six bits.
3878 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3879 If defined, the number of milliseconds to delay between
3880 page writes. The default is zero milliseconds.
3882 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3883 The length in bytes of the EEPROM memory array address. Note
3884 that this is NOT the chip address length!
3886 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3887 EEPROM chips that implement "address overflow" are ones
3888 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3889 address and the extra bits end up in the "chip address" bit
3890 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3893 Note that we consider the length of the address field to
3894 still be one byte because the extra address bits are hidden
3895 in the chip address.
3897 - CONFIG_SYS_EEPROM_SIZE:
3898 The size in bytes of the EEPROM device.
3900 - CONFIG_ENV_EEPROM_IS_ON_I2C
3901 define this, if you have I2C and SPI activated, and your
3902 EEPROM, which holds the environment, is on the I2C bus.
3904 - CONFIG_I2C_ENV_EEPROM_BUS
3905 if you have an Environment on an EEPROM reached over
3906 I2C muxes, you can define here, how to reach this
3907 EEPROM. For example:
3909 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3911 EEPROM which holds the environment, is reached over
3912 a pca9547 i2c mux with address 0x70, channel 3.
3914 - CONFIG_ENV_IS_IN_DATAFLASH:
3916 Define this if you have a DataFlash memory device which you
3917 want to use for the environment.
3919 - CONFIG_ENV_OFFSET:
3923 These three #defines specify the offset and size of the
3924 environment area within the total memory of your DataFlash placed
3925 at the specified address.
3927 - CONFIG_ENV_IS_IN_REMOTE:
3929 Define this if you have a remote memory space which you
3930 want to use for the local device's environment.
3935 These two #defines specify the address and size of the
3936 environment area within the remote memory space. The
3937 local device can get the environment from remote memory
3938 space by SRIO or PCIE links.
3940 BE CAREFUL! For some special cases, the local device can not use
3941 "saveenv" command. For example, the local device will get the
3942 environment stored in a remote NOR flash by SRIO or PCIE link,
3943 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3945 - CONFIG_ENV_IS_IN_NAND:
3947 Define this if you have a NAND device which you want to use
3948 for the environment.
3950 - CONFIG_ENV_OFFSET:
3953 These two #defines specify the offset and size of the environment
3954 area within the first NAND device. CONFIG_ENV_OFFSET must be
3955 aligned to an erase block boundary.
3957 - CONFIG_ENV_OFFSET_REDUND (optional):
3959 This setting describes a second storage area of CONFIG_ENV_SIZE
3960 size used to hold a redundant copy of the environment data, so
3961 that there is a valid backup copy in case there is a power failure
3962 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3963 aligned to an erase block boundary.
3965 - CONFIG_ENV_RANGE (optional):
3967 Specifies the length of the region in which the environment
3968 can be written. This should be a multiple of the NAND device's
3969 block size. Specifying a range with more erase blocks than
3970 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3971 the range to be avoided.
3973 - CONFIG_ENV_OFFSET_OOB (optional):
3975 Enables support for dynamically retrieving the offset of the
3976 environment from block zero's out-of-band data. The
3977 "nand env.oob" command can be used to record this offset.
3978 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3979 using CONFIG_ENV_OFFSET_OOB.
3981 - CONFIG_NAND_ENV_DST
3983 Defines address in RAM to which the nand_spl code should copy the
3984 environment. If redundant environment is used, it will be copied to
3985 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3987 - CONFIG_ENV_IS_IN_UBI:
3989 Define this if you have an UBI volume that you want to use for the
3990 environment. This has the benefit of wear-leveling the environment
3991 accesses, which is important on NAND.
3993 - CONFIG_ENV_UBI_PART:
3995 Define this to a string that is the mtd partition containing the UBI.
3997 - CONFIG_ENV_UBI_VOLUME:
3999 Define this to the name of the volume that you want to store the
4002 - CONFIG_ENV_UBI_VOLUME_REDUND:
4004 Define this to the name of another volume to store a second copy of
4005 the environment in. This will enable redundant environments in UBI.
4006 It is assumed that both volumes are in the same MTD partition.
4008 - CONFIG_UBI_SILENCE_MSG
4009 - CONFIG_UBIFS_SILENCE_MSG
4011 You will probably want to define these to avoid a really noisy system
4012 when storing the env in UBI.
4014 - CONFIG_ENV_IS_IN_MMC:
4016 Define this if you have an MMC device which you want to use for the
4019 - CONFIG_SYS_MMC_ENV_DEV:
4021 Specifies which MMC device the environment is stored in.
4023 - CONFIG_SYS_MMC_ENV_PART (optional):
4025 Specifies which MMC partition the environment is stored in. If not
4026 set, defaults to partition 0, the user area. Common values might be
4027 1 (first MMC boot partition), 2 (second MMC boot partition).
4029 - CONFIG_ENV_OFFSET:
4032 These two #defines specify the offset and size of the environment
4033 area within the specified MMC device.
4035 If offset is positive (the usual case), it is treated as relative to
4036 the start of the MMC partition. If offset is negative, it is treated
4037 as relative to the end of the MMC partition. This can be useful if
4038 your board may be fitted with different MMC devices, which have
4039 different sizes for the MMC partitions, and you always want the
4040 environment placed at the very end of the partition, to leave the
4041 maximum possible space before it, to store other data.
4043 These two values are in units of bytes, but must be aligned to an
4044 MMC sector boundary.
4046 - CONFIG_ENV_OFFSET_REDUND (optional):
4048 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4049 hold a redundant copy of the environment data. This provides a
4050 valid backup copy in case the other copy is corrupted, e.g. due
4051 to a power failure during a "saveenv" operation.
4053 This value may also be positive or negative; this is handled in the
4054 same way as CONFIG_ENV_OFFSET.
4056 This value is also in units of bytes, but must also be aligned to
4057 an MMC sector boundary.
4059 - CONFIG_ENV_SIZE_REDUND (optional):
4061 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4062 set. If this value is set, it must be set to the same value as
4065 - CONFIG_SYS_SPI_INIT_OFFSET
4067 Defines offset to the initial SPI buffer area in DPRAM. The
4068 area is used at an early stage (ROM part) if the environment
4069 is configured to reside in the SPI EEPROM: We need a 520 byte
4070 scratch DPRAM area. It is used between the two initialization
4071 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4072 to be a good choice since it makes it far enough from the
4073 start of the data area as well as from the stack pointer.
4075 Please note that the environment is read-only until the monitor
4076 has been relocated to RAM and a RAM copy of the environment has been
4077 created; also, when using EEPROM you will have to use getenv_f()
4078 until then to read environment variables.
4080 The environment is protected by a CRC32 checksum. Before the monitor
4081 is relocated into RAM, as a result of a bad CRC you will be working
4082 with the compiled-in default environment - *silently*!!! [This is
4083 necessary, because the first environment variable we need is the
4084 "baudrate" setting for the console - if we have a bad CRC, we don't
4085 have any device yet where we could complain.]
4087 Note: once the monitor has been relocated, then it will complain if
4088 the default environment is used; a new CRC is computed as soon as you
4089 use the "saveenv" command to store a valid environment.
4091 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4092 Echo the inverted Ethernet link state to the fault LED.
4094 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4095 also needs to be defined.
4097 - CONFIG_SYS_FAULT_MII_ADDR:
4098 MII address of the PHY to check for the Ethernet link state.
4100 - CONFIG_NS16550_MIN_FUNCTIONS:
4101 Define this if you desire to only have use of the NS16550_init
4102 and NS16550_putc functions for the serial driver located at
4103 drivers/serial/ns16550.c. This option is useful for saving
4104 space for already greatly restricted images, including but not
4105 limited to NAND_SPL configurations.
4107 - CONFIG_DISPLAY_BOARDINFO
4108 Display information about the board that U-Boot is running on
4109 when U-Boot starts up. The board function checkboard() is called
4112 - CONFIG_DISPLAY_BOARDINFO_LATE
4113 Similar to the previous option, but display this information
4114 later, once stdio is running and output goes to the LCD, if
4117 Low Level (hardware related) configuration options:
4118 ---------------------------------------------------
4120 - CONFIG_SYS_CACHELINE_SIZE:
4121 Cache Line Size of the CPU.
4123 - CONFIG_SYS_DEFAULT_IMMR:
4124 Default address of the IMMR after system reset.
4126 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4127 and RPXsuper) to be able to adjust the position of
4128 the IMMR register after a reset.
4130 - CONFIG_SYS_CCSRBAR_DEFAULT:
4131 Default (power-on reset) physical address of CCSR on Freescale
4134 - CONFIG_SYS_CCSRBAR:
4135 Virtual address of CCSR. On a 32-bit build, this is typically
4136 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4138 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4139 for cross-platform code that uses that macro instead.
4141 - CONFIG_SYS_CCSRBAR_PHYS:
4142 Physical address of CCSR. CCSR can be relocated to a new
4143 physical address, if desired. In this case, this macro should
4144 be set to that address. Otherwise, it should be set to the
4145 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4146 is typically relocated on 36-bit builds. It is recommended
4147 that this macro be defined via the _HIGH and _LOW macros:
4149 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4150 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4152 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4153 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4154 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4155 used in assembly code, so it must not contain typecasts or
4156 integer size suffixes (e.g. "ULL").
4158 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4159 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4160 used in assembly code, so it must not contain typecasts or
4161 integer size suffixes (e.g. "ULL").
4163 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4164 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4165 forced to a value that ensures that CCSR is not relocated.
4167 - Floppy Disk Support:
4168 CONFIG_SYS_FDC_DRIVE_NUMBER
4170 the default drive number (default value 0)
4172 CONFIG_SYS_ISA_IO_STRIDE
4174 defines the spacing between FDC chipset registers
4177 CONFIG_SYS_ISA_IO_OFFSET
4179 defines the offset of register from address. It
4180 depends on which part of the data bus is connected to
4181 the FDC chipset. (default value 0)
4183 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4184 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4187 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4188 fdc_hw_init() is called at the beginning of the FDC
4189 setup. fdc_hw_init() must be provided by the board
4190 source code. It is used to make hardware dependant
4194 Most IDE controllers were designed to be connected with PCI
4195 interface. Only few of them were designed for AHB interface.
4196 When software is doing ATA command and data transfer to
4197 IDE devices through IDE-AHB controller, some additional
4198 registers accessing to these kind of IDE-AHB controller
4201 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4202 DO NOT CHANGE unless you know exactly what you're
4203 doing! (11-4) [MPC8xx/82xx systems only]
4205 - CONFIG_SYS_INIT_RAM_ADDR:
4207 Start address of memory area that can be used for
4208 initial data and stack; please note that this must be
4209 writable memory that is working WITHOUT special
4210 initialization, i. e. you CANNOT use normal RAM which
4211 will become available only after programming the
4212 memory controller and running certain initialization
4215 U-Boot uses the following memory types:
4216 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4217 - MPC824X: data cache
4218 - PPC4xx: data cache
4220 - CONFIG_SYS_GBL_DATA_OFFSET:
4222 Offset of the initial data structure in the memory
4223 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4224 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4225 data is located at the end of the available space
4226 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4227 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4228 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4229 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4232 On the MPC824X (or other systems that use the data
4233 cache for initial memory) the address chosen for
4234 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4235 point to an otherwise UNUSED address space between
4236 the top of RAM and the start of the PCI space.
4238 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4240 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4242 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4244 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4246 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4248 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4250 - CONFIG_SYS_OR_TIMING_SDRAM:
4253 - CONFIG_SYS_MAMR_PTA:
4254 periodic timer for refresh
4256 - CONFIG_SYS_DER: Debug Event Register (37-47)
4258 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4259 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4260 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4261 CONFIG_SYS_BR1_PRELIM:
4262 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4264 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4265 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4266 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4267 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4269 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4270 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4271 Machine Mode Register and Memory Periodic Timer
4272 Prescaler definitions (SDRAM timing)
4274 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4275 enable I2C microcode relocation patch (MPC8xx);
4276 define relocation offset in DPRAM [DSP2]
4278 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4279 enable SMC microcode relocation patch (MPC8xx);
4280 define relocation offset in DPRAM [SMC1]
4282 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4283 enable SPI microcode relocation patch (MPC8xx);
4284 define relocation offset in DPRAM [SCC4]
4286 - CONFIG_SYS_USE_OSCCLK:
4287 Use OSCM clock mode on MBX8xx board. Be careful,
4288 wrong setting might damage your board. Read
4289 doc/README.MBX before setting this variable!
4291 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4292 Offset of the bootmode word in DPRAM used by post
4293 (Power On Self Tests). This definition overrides
4294 #define'd default value in commproc.h resp.
4297 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4298 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4299 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4300 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4301 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4302 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4303 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4304 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4305 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4307 - CONFIG_PCI_DISABLE_PCIE:
4308 Disable PCI-Express on systems where it is supported but not
4311 - CONFIG_PCI_ENUM_ONLY
4312 Only scan through and get the devices on the busses.
4313 Don't do any setup work, presumably because someone or
4314 something has already done it, and we don't need to do it
4315 a second time. Useful for platforms that are pre-booted
4316 by coreboot or similar.
4318 - CONFIG_PCI_INDIRECT_BRIDGE:
4319 Enable support for indirect PCI bridges.
4322 Chip has SRIO or not
4325 Board has SRIO 1 port available
4328 Board has SRIO 2 port available
4330 - CONFIG_SRIO_PCIE_BOOT_MASTER
4331 Board can support master function for Boot from SRIO and PCIE
4333 - CONFIG_SYS_SRIOn_MEM_VIRT:
4334 Virtual Address of SRIO port 'n' memory region
4336 - CONFIG_SYS_SRIOn_MEM_PHYS:
4337 Physical Address of SRIO port 'n' memory region
4339 - CONFIG_SYS_SRIOn_MEM_SIZE:
4340 Size of SRIO port 'n' memory region
4342 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4343 Defined to tell the NAND controller that the NAND chip is using
4345 Not all NAND drivers use this symbol.
4346 Example of drivers that use it:
4347 - drivers/mtd/nand/ndfc.c
4348 - drivers/mtd/nand/mxc_nand.c
4350 - CONFIG_SYS_NDFC_EBC0_CFG
4351 Sets the EBC0_CFG register for the NDFC. If not defined
4352 a default value will be used.
4355 Get DDR timing information from an I2C EEPROM. Common
4356 with pluggable memory modules such as SODIMMs
4359 I2C address of the SPD EEPROM
4361 - CONFIG_SYS_SPD_BUS_NUM
4362 If SPD EEPROM is on an I2C bus other than the first
4363 one, specify here. Note that the value must resolve
4364 to something your driver can deal with.
4366 - CONFIG_SYS_DDR_RAW_TIMING
4367 Get DDR timing information from other than SPD. Common with
4368 soldered DDR chips onboard without SPD. DDR raw timing
4369 parameters are extracted from datasheet and hard-coded into
4370 header files or board specific files.
4372 - CONFIG_FSL_DDR_INTERACTIVE
4373 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4375 - CONFIG_SYS_83XX_DDR_USES_CS0
4376 Only for 83xx systems. If specified, then DDR should
4377 be configured using CS0 and CS1 instead of CS2 and CS3.
4379 - CONFIG_ETHER_ON_FEC[12]
4380 Define to enable FEC[12] on a 8xx series processor.
4382 - CONFIG_FEC[12]_PHY
4383 Define to the hardcoded PHY address which corresponds
4384 to the given FEC; i. e.
4385 #define CONFIG_FEC1_PHY 4
4386 means that the PHY with address 4 is connected to FEC1
4388 When set to -1, means to probe for first available.
4390 - CONFIG_FEC[12]_PHY_NORXERR
4391 The PHY does not have a RXERR line (RMII only).
4392 (so program the FEC to ignore it).
4395 Enable RMII mode for all FECs.
4396 Note that this is a global option, we can't
4397 have one FEC in standard MII mode and another in RMII mode.
4399 - CONFIG_CRC32_VERIFY
4400 Add a verify option to the crc32 command.
4403 => crc32 -v <address> <count> <crc32>
4405 Where address/count indicate a memory area
4406 and crc32 is the correct crc32 which the
4410 Add the "loopw" memory command. This only takes effect if
4411 the memory commands are activated globally (CONFIG_CMD_MEM).
4414 Add the "mdc" and "mwc" memory commands. These are cyclic
4419 This command will print 4 bytes (10,11,12,13) each 500 ms.
4421 => mwc.l 100 12345678 10
4422 This command will write 12345678 to address 100 all 10 ms.
4424 This only takes effect if the memory commands are activated
4425 globally (CONFIG_CMD_MEM).
4427 - CONFIG_SKIP_LOWLEVEL_INIT
4428 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4429 low level initializations (like setting up the memory
4430 controller) are omitted and/or U-Boot does not
4431 relocate itself into RAM.
4433 Normally this variable MUST NOT be defined. The only
4434 exception is when U-Boot is loaded (to RAM) by some
4435 other boot loader or by a debugger which performs
4436 these initializations itself.
4439 Modifies the behaviour of start.S when compiling a loader
4440 that is executed before the actual U-Boot. E.g. when
4441 compiling a NAND SPL.
4444 Modifies the behaviour of start.S when compiling a loader
4445 that is executed after the SPL and before the actual U-Boot.
4446 It is loaded by the SPL.
4448 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4449 Only for 85xx systems. If this variable is specified, the section
4450 .resetvec is not kept and the section .bootpg is placed in the
4451 previous 4k of the .text section.
4453 - CONFIG_ARCH_MAP_SYSMEM
4454 Generally U-Boot (and in particular the md command) uses
4455 effective address. It is therefore not necessary to regard
4456 U-Boot address as virtual addresses that need to be translated
4457 to physical addresses. However, sandbox requires this, since
4458 it maintains its own little RAM buffer which contains all
4459 addressable memory. This option causes some memory accesses
4460 to be mapped through map_sysmem() / unmap_sysmem().
4462 - CONFIG_USE_ARCH_MEMCPY
4463 CONFIG_USE_ARCH_MEMSET
4464 If these options are used a optimized version of memcpy/memset will
4465 be used if available. These functions may be faster under some
4466 conditions but may increase the binary size.
4468 - CONFIG_X86_RESET_VECTOR
4469 If defined, the x86 reset vector code is included. This is not
4470 needed when U-Boot is running from Coreboot.
4473 Defines the MPU clock speed (in MHz).
4475 NOTE : currently only supported on AM335x platforms.
4477 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4478 Enables the RTC32K OSC on AM33xx based plattforms
4480 Freescale QE/FMAN Firmware Support:
4481 -----------------------------------
4483 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4484 loading of "firmware", which is encoded in the QE firmware binary format.
4485 This firmware often needs to be loaded during U-Boot booting, so macros
4486 are used to identify the storage device (NOR flash, SPI, etc) and the address
4489 - CONFIG_SYS_QE_FMAN_FW_ADDR
4490 The address in the storage device where the firmware is located. The
4491 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4494 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4495 The maximum possible size of the firmware. The firmware binary format
4496 has a field that specifies the actual size of the firmware, but it
4497 might not be possible to read any part of the firmware unless some
4498 local storage is allocated to hold the entire firmware first.
4500 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4501 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4502 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4503 virtual address in NOR flash.
4505 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4506 Specifies that QE/FMAN firmware is located in NAND flash.
4507 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4509 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4510 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4511 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4513 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4514 Specifies that QE/FMAN firmware is located on the primary SPI
4515 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4517 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4518 Specifies that QE/FMAN firmware is located in the remote (master)
4519 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4520 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4521 window->master inbound window->master LAW->the ucode address in
4522 master's memory space.
4524 Building the Software:
4525 ======================
4527 Building U-Boot has been tested in several native build environments
4528 and in many different cross environments. Of course we cannot support
4529 all possibly existing versions of cross development tools in all
4530 (potentially obsolete) versions. In case of tool chain problems we
4531 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4532 which is extensively used to build and test U-Boot.
4534 If you are not using a native environment, it is assumed that you
4535 have GNU cross compiling tools available in your path. In this case,
4536 you must set the environment variable CROSS_COMPILE in your shell.
4537 Note that no changes to the Makefile or any other source files are
4538 necessary. For example using the ELDK on a 4xx CPU, please enter:
4540 $ CROSS_COMPILE=ppc_4xx-
4541 $ export CROSS_COMPILE
4543 Note: If you wish to generate Windows versions of the utilities in
4544 the tools directory you can use the MinGW toolchain
4545 (http://www.mingw.org). Set your HOST tools to the MinGW
4546 toolchain and execute 'make tools'. For example:
4548 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4550 Binaries such as tools/mkimage.exe will be created which can
4551 be executed on computers running Windows.
4553 U-Boot is intended to be simple to build. After installing the
4554 sources you must configure U-Boot for one specific board type. This
4559 where "NAME_config" is the name of one of the existing configu-
4560 rations; see boards.cfg for supported names.
4562 Note: for some board special configuration names may exist; check if
4563 additional information is available from the board vendor; for
4564 instance, the TQM823L systems are available without (standard)
4565 or with LCD support. You can select such additional "features"
4566 when choosing the configuration, i. e.
4569 - will configure for a plain TQM823L, i. e. no LCD support
4571 make TQM823L_LCD_config
4572 - will configure for a TQM823L with U-Boot console on LCD
4577 Finally, type "make all", and you should get some working U-Boot
4578 images ready for download to / installation on your system:
4580 - "u-boot.bin" is a raw binary image
4581 - "u-boot" is an image in ELF binary format
4582 - "u-boot.srec" is in Motorola S-Record format
4584 By default the build is performed locally and the objects are saved
4585 in the source directory. One of the two methods can be used to change
4586 this behavior and build U-Boot to some external directory:
4588 1. Add O= to the make command line invocations:
4590 make O=/tmp/build distclean
4591 make O=/tmp/build NAME_config
4592 make O=/tmp/build all
4594 2. Set environment variable BUILD_DIR to point to the desired location:
4596 export BUILD_DIR=/tmp/build
4601 Note that the command line "O=" setting overrides the BUILD_DIR environment
4605 Please be aware that the Makefiles assume you are using GNU make, so
4606 for instance on NetBSD you might need to use "gmake" instead of
4610 If the system board that you have is not listed, then you will need
4611 to port U-Boot to your hardware platform. To do this, follow these
4614 1. Add a new configuration option for your board to the toplevel
4615 "boards.cfg" file, using the existing entries as examples.
4616 Follow the instructions there to keep the boards in order.
4617 2. Create a new directory to hold your board specific code. Add any
4618 files you need. In your board directory, you will need at least
4619 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4620 3. Create a new configuration file "include/configs/<board>.h" for
4622 3. If you're porting U-Boot to a new CPU, then also create a new
4623 directory to hold your CPU specific code. Add any files you need.
4624 4. Run "make <board>_config" with your new name.
4625 5. Type "make", and you should get a working "u-boot.srec" file
4626 to be installed on your target system.
4627 6. Debug and solve any problems that might arise.
4628 [Of course, this last step is much harder than it sounds.]
4631 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4632 ==============================================================
4634 If you have modified U-Boot sources (for instance added a new board
4635 or support for new devices, a new CPU, etc.) you are expected to
4636 provide feedback to the other developers. The feedback normally takes
4637 the form of a "patch", i. e. a context diff against a certain (latest
4638 official or latest in the git repository) version of U-Boot sources.
4640 But before you submit such a patch, please verify that your modifi-
4641 cation did not break existing code. At least make sure that *ALL* of
4642 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4643 just run the "MAKEALL" script, which will configure and build U-Boot
4644 for ALL supported system. Be warned, this will take a while. You can
4645 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4646 environment variable to the script, i. e. to use the ELDK cross tools
4649 CROSS_COMPILE=ppc_8xx- MAKEALL
4651 or to build on a native PowerPC system you can type
4653 CROSS_COMPILE=' ' MAKEALL
4655 When using the MAKEALL script, the default behaviour is to build
4656 U-Boot in the source directory. This location can be changed by
4657 setting the BUILD_DIR environment variable. Also, for each target
4658 built, the MAKEALL script saves two log files (<target>.ERR and
4659 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4660 location can be changed by setting the MAKEALL_LOGDIR environment
4661 variable. For example:
4663 export BUILD_DIR=/tmp/build
4664 export MAKEALL_LOGDIR=/tmp/log
4665 CROSS_COMPILE=ppc_8xx- MAKEALL
4667 With the above settings build objects are saved in the /tmp/build,
4668 log files are saved in the /tmp/log and the source tree remains clean
4669 during the whole build process.
4672 See also "U-Boot Porting Guide" below.
4675 Monitor Commands - Overview:
4676 ============================
4678 go - start application at address 'addr'
4679 run - run commands in an environment variable
4680 bootm - boot application image from memory
4681 bootp - boot image via network using BootP/TFTP protocol
4682 bootz - boot zImage from memory
4683 tftpboot- boot image via network using TFTP protocol
4684 and env variables "ipaddr" and "serverip"
4685 (and eventually "gatewayip")
4686 tftpput - upload a file via network using TFTP protocol
4687 rarpboot- boot image via network using RARP/TFTP protocol
4688 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4689 loads - load S-Record file over serial line
4690 loadb - load binary file over serial line (kermit mode)
4692 mm - memory modify (auto-incrementing)
4693 nm - memory modify (constant address)
4694 mw - memory write (fill)
4696 cmp - memory compare
4697 crc32 - checksum calculation
4698 i2c - I2C sub-system
4699 sspi - SPI utility commands
4700 base - print or set address offset
4701 printenv- print environment variables
4702 setenv - set environment variables
4703 saveenv - save environment variables to persistent storage
4704 protect - enable or disable FLASH write protection
4705 erase - erase FLASH memory
4706 flinfo - print FLASH memory information
4707 nand - NAND memory operations (see doc/README.nand)
4708 bdinfo - print Board Info structure
4709 iminfo - print header information for application image
4710 coninfo - print console devices and informations
4711 ide - IDE sub-system
4712 loop - infinite loop on address range
4713 loopw - infinite write loop on address range
4714 mtest - simple RAM test
4715 icache - enable or disable instruction cache
4716 dcache - enable or disable data cache
4717 reset - Perform RESET of the CPU
4718 echo - echo args to console
4719 version - print monitor version
4720 help - print online help
4721 ? - alias for 'help'
4724 Monitor Commands - Detailed Description:
4725 ========================================
4729 For now: just type "help <command>".
4732 Environment Variables:
4733 ======================
4735 U-Boot supports user configuration using Environment Variables which
4736 can be made persistent by saving to Flash memory.
4738 Environment Variables are set using "setenv", printed using
4739 "printenv", and saved to Flash using "saveenv". Using "setenv"
4740 without a value can be used to delete a variable from the
4741 environment. As long as you don't save the environment you are
4742 working with an in-memory copy. In case the Flash area containing the
4743 environment is erased by accident, a default environment is provided.
4745 Some configuration options can be set using Environment Variables.
4747 List of environment variables (most likely not complete):
4749 baudrate - see CONFIG_BAUDRATE
4751 bootdelay - see CONFIG_BOOTDELAY
4753 bootcmd - see CONFIG_BOOTCOMMAND
4755 bootargs - Boot arguments when booting an RTOS image
4757 bootfile - Name of the image to load with TFTP
4759 bootm_low - Memory range available for image processing in the bootm
4760 command can be restricted. This variable is given as
4761 a hexadecimal number and defines lowest address allowed
4762 for use by the bootm command. See also "bootm_size"
4763 environment variable. Address defined by "bootm_low" is
4764 also the base of the initial memory mapping for the Linux
4765 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4768 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4769 This variable is given as a hexadecimal number and it
4770 defines the size of the memory region starting at base
4771 address bootm_low that is accessible by the Linux kernel
4772 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4773 as the default value if it is defined, and bootm_size is
4776 bootm_size - Memory range available for image processing in the bootm
4777 command can be restricted. This variable is given as
4778 a hexadecimal number and defines the size of the region
4779 allowed for use by the bootm command. See also "bootm_low"
4780 environment variable.
4782 updatefile - Location of the software update file on a TFTP server, used
4783 by the automatic software update feature. Please refer to
4784 documentation in doc/README.update for more details.
4786 autoload - if set to "no" (any string beginning with 'n'),
4787 "bootp" will just load perform a lookup of the
4788 configuration from the BOOTP server, but not try to
4789 load any image using TFTP
4791 autostart - if set to "yes", an image loaded using the "bootp",
4792 "rarpboot", "tftpboot" or "diskboot" commands will
4793 be automatically started (by internally calling
4796 If set to "no", a standalone image passed to the
4797 "bootm" command will be copied to the load address
4798 (and eventually uncompressed), but NOT be started.
4799 This can be used to load and uncompress arbitrary
4802 fdt_high - if set this restricts the maximum address that the
4803 flattened device tree will be copied into upon boot.
4804 For example, if you have a system with 1 GB memory
4805 at physical address 0x10000000, while Linux kernel
4806 only recognizes the first 704 MB as low memory, you
4807 may need to set fdt_high as 0x3C000000 to have the
4808 device tree blob be copied to the maximum address
4809 of the 704 MB low memory, so that Linux kernel can
4810 access it during the boot procedure.
4812 If this is set to the special value 0xFFFFFFFF then
4813 the fdt will not be copied at all on boot. For this
4814 to work it must reside in writable memory, have
4815 sufficient padding on the end of it for u-boot to
4816 add the information it needs into it, and the memory
4817 must be accessible by the kernel.
4819 fdtcontroladdr- if set this is the address of the control flattened
4820 device tree used by U-Boot when CONFIG_OF_CONTROL is
4823 i2cfast - (PPC405GP|PPC405EP only)
4824 if set to 'y' configures Linux I2C driver for fast
4825 mode (400kHZ). This environment variable is used in
4826 initialization code. So, for changes to be effective
4827 it must be saved and board must be reset.
4829 initrd_high - restrict positioning of initrd images:
4830 If this variable is not set, initrd images will be
4831 copied to the highest possible address in RAM; this
4832 is usually what you want since it allows for
4833 maximum initrd size. If for some reason you want to
4834 make sure that the initrd image is loaded below the
4835 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4836 variable to a value of "no" or "off" or "0".
4837 Alternatively, you can set it to a maximum upper
4838 address to use (U-Boot will still check that it
4839 does not overwrite the U-Boot stack and data).
4841 For instance, when you have a system with 16 MB
4842 RAM, and want to reserve 4 MB from use by Linux,
4843 you can do this by adding "mem=12M" to the value of
4844 the "bootargs" variable. However, now you must make
4845 sure that the initrd image is placed in the first
4846 12 MB as well - this can be done with
4848 setenv initrd_high 00c00000
4850 If you set initrd_high to 0xFFFFFFFF, this is an
4851 indication to U-Boot that all addresses are legal
4852 for the Linux kernel, including addresses in flash
4853 memory. In this case U-Boot will NOT COPY the
4854 ramdisk at all. This may be useful to reduce the
4855 boot time on your system, but requires that this
4856 feature is supported by your Linux kernel.
4858 ipaddr - IP address; needed for tftpboot command
4860 loadaddr - Default load address for commands like "bootp",
4861 "rarpboot", "tftpboot", "loadb" or "diskboot"
4863 loads_echo - see CONFIG_LOADS_ECHO
4865 serverip - TFTP server IP address; needed for tftpboot command
4867 bootretry - see CONFIG_BOOT_RETRY_TIME
4869 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4871 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4873 ethprime - controls which interface is used first.
4875 ethact - controls which interface is currently active.
4876 For example you can do the following
4878 => setenv ethact FEC
4879 => ping 192.168.0.1 # traffic sent on FEC
4880 => setenv ethact SCC
4881 => ping 10.0.0.1 # traffic sent on SCC
4883 ethrotate - When set to "no" U-Boot does not go through all
4884 available network interfaces.
4885 It just stays at the currently selected interface.
4887 netretry - When set to "no" each network operation will
4888 either succeed or fail without retrying.
4889 When set to "once" the network operation will
4890 fail when all the available network interfaces
4891 are tried once without success.
4892 Useful on scripts which control the retry operation
4895 npe_ucode - set load address for the NPE microcode
4897 silent_linux - If set then linux will be told to boot silently, by
4898 changing the console to be empty. If "yes" it will be
4899 made silent. If "no" it will not be made silent. If
4900 unset, then it will be made silent if the U-Boot console
4903 tftpsrcport - If this is set, the value is used for TFTP's
4906 tftpdstport - If this is set, the value is used for TFTP's UDP
4907 destination port instead of the Well Know Port 69.
4909 tftpblocksize - Block size to use for TFTP transfers; if not set,
4910 we use the TFTP server's default block size
4912 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4913 seconds, minimum value is 1000 = 1 second). Defines
4914 when a packet is considered to be lost so it has to
4915 be retransmitted. The default is 5000 = 5 seconds.
4916 Lowering this value may make downloads succeed
4917 faster in networks with high packet loss rates or
4918 with unreliable TFTP servers.
4920 vlan - When set to a value < 4095 the traffic over
4921 Ethernet is encapsulated/received over 802.1q
4924 The following image location variables contain the location of images
4925 used in booting. The "Image" column gives the role of the image and is
4926 not an environment variable name. The other columns are environment
4927 variable names. "File Name" gives the name of the file on a TFTP
4928 server, "RAM Address" gives the location in RAM the image will be
4929 loaded to, and "Flash Location" gives the image's address in NOR
4930 flash or offset in NAND flash.
4932 *Note* - these variables don't have to be defined for all boards, some
4933 boards currenlty use other variables for these purposes, and some
4934 boards use these variables for other purposes.
4936 Image File Name RAM Address Flash Location
4937 ----- --------- ----------- --------------
4938 u-boot u-boot u-boot_addr_r u-boot_addr
4939 Linux kernel bootfile kernel_addr_r kernel_addr
4940 device tree blob fdtfile fdt_addr_r fdt_addr
4941 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4943 The following environment variables may be used and automatically
4944 updated by the network boot commands ("bootp" and "rarpboot"),
4945 depending the information provided by your boot server:
4947 bootfile - see above
4948 dnsip - IP address of your Domain Name Server
4949 dnsip2 - IP address of your secondary Domain Name Server
4950 gatewayip - IP address of the Gateway (Router) to use
4951 hostname - Target hostname
4953 netmask - Subnet Mask
4954 rootpath - Pathname of the root filesystem on the NFS server
4955 serverip - see above
4958 There are two special Environment Variables:
4960 serial# - contains hardware identification information such
4961 as type string and/or serial number
4962 ethaddr - Ethernet address
4964 These variables can be set only once (usually during manufacturing of
4965 the board). U-Boot refuses to delete or overwrite these variables
4966 once they have been set once.
4969 Further special Environment Variables:
4971 ver - Contains the U-Boot version string as printed
4972 with the "version" command. This variable is
4973 readonly (see CONFIG_VERSION_VARIABLE).
4976 Please note that changes to some configuration parameters may take
4977 only effect after the next boot (yes, that's just like Windoze :-).
4980 Callback functions for environment variables:
4981 ---------------------------------------------
4983 For some environment variables, the behavior of u-boot needs to change
4984 when their values are changed. This functionailty allows functions to
4985 be associated with arbitrary variables. On creation, overwrite, or
4986 deletion, the callback will provide the opportunity for some side
4987 effect to happen or for the change to be rejected.
4989 The callbacks are named and associated with a function using the
4990 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4992 These callbacks are associated with variables in one of two ways. The
4993 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4994 in the board configuration to a string that defines a list of
4995 associations. The list must be in the following format:
4997 entry = variable_name[:callback_name]
5000 If the callback name is not specified, then the callback is deleted.
5001 Spaces are also allowed anywhere in the list.
5003 Callbacks can also be associated by defining the ".callbacks" variable
5004 with the same list format above. Any association in ".callbacks" will
5005 override any association in the static list. You can define
5006 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5007 ".callbacks" envirnoment variable in the default or embedded environment.
5010 Command Line Parsing:
5011 =====================
5013 There are two different command line parsers available with U-Boot:
5014 the old "simple" one, and the much more powerful "hush" shell:
5016 Old, simple command line parser:
5017 --------------------------------
5019 - supports environment variables (through setenv / saveenv commands)
5020 - several commands on one line, separated by ';'
5021 - variable substitution using "... ${name} ..." syntax
5022 - special characters ('$', ';') can be escaped by prefixing with '\',
5024 setenv bootcmd bootm \${address}
5025 - You can also escape text by enclosing in single apostrophes, for example:
5026 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5031 - similar to Bourne shell, with control structures like
5032 if...then...else...fi, for...do...done; while...do...done,
5033 until...do...done, ...
5034 - supports environment ("global") variables (through setenv / saveenv
5035 commands) and local shell variables (through standard shell syntax
5036 "name=value"); only environment variables can be used with "run"
5042 (1) If a command line (or an environment variable executed by a "run"
5043 command) contains several commands separated by semicolon, and
5044 one of these commands fails, then the remaining commands will be
5047 (2) If you execute several variables with one call to run (i. e.
5048 calling run with a list of variables as arguments), any failing
5049 command will cause "run" to terminate, i. e. the remaining
5050 variables are not executed.
5052 Note for Redundant Ethernet Interfaces:
5053 =======================================
5055 Some boards come with redundant Ethernet interfaces; U-Boot supports
5056 such configurations and is capable of automatic selection of a
5057 "working" interface when needed. MAC assignment works as follows:
5059 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5060 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5061 "eth1addr" (=>eth1), "eth2addr", ...
5063 If the network interface stores some valid MAC address (for instance
5064 in SROM), this is used as default address if there is NO correspon-
5065 ding setting in the environment; if the corresponding environment
5066 variable is set, this overrides the settings in the card; that means:
5068 o If the SROM has a valid MAC address, and there is no address in the
5069 environment, the SROM's address is used.
5071 o If there is no valid address in the SROM, and a definition in the
5072 environment exists, then the value from the environment variable is
5075 o If both the SROM and the environment contain a MAC address, and
5076 both addresses are the same, this MAC address is used.
5078 o If both the SROM and the environment contain a MAC address, and the
5079 addresses differ, the value from the environment is used and a
5082 o If neither SROM nor the environment contain a MAC address, an error
5085 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5086 will be programmed into hardware as part of the initialization process. This
5087 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5088 The naming convention is as follows:
5089 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5094 U-Boot is capable of booting (and performing other auxiliary operations on)
5095 images in two formats:
5097 New uImage format (FIT)
5098 -----------------------
5100 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5101 to Flattened Device Tree). It allows the use of images with multiple
5102 components (several kernels, ramdisks, etc.), with contents protected by
5103 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5109 Old image format is based on binary files which can be basically anything,
5110 preceded by a special header; see the definitions in include/image.h for
5111 details; basically, the header defines the following image properties:
5113 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5114 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5115 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5116 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5118 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5119 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5120 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5121 * Compression Type (uncompressed, gzip, bzip2)
5127 The header is marked by a special Magic Number, and both the header
5128 and the data portions of the image are secured against corruption by
5135 Although U-Boot should support any OS or standalone application
5136 easily, the main focus has always been on Linux during the design of
5139 U-Boot includes many features that so far have been part of some
5140 special "boot loader" code within the Linux kernel. Also, any
5141 "initrd" images to be used are no longer part of one big Linux image;
5142 instead, kernel and "initrd" are separate images. This implementation
5143 serves several purposes:
5145 - the same features can be used for other OS or standalone
5146 applications (for instance: using compressed images to reduce the
5147 Flash memory footprint)
5149 - it becomes much easier to port new Linux kernel versions because
5150 lots of low-level, hardware dependent stuff are done by U-Boot
5152 - the same Linux kernel image can now be used with different "initrd"
5153 images; of course this also means that different kernel images can
5154 be run with the same "initrd". This makes testing easier (you don't
5155 have to build a new "zImage.initrd" Linux image when you just
5156 change a file in your "initrd"). Also, a field-upgrade of the
5157 software is easier now.
5163 Porting Linux to U-Boot based systems:
5164 ---------------------------------------
5166 U-Boot cannot save you from doing all the necessary modifications to
5167 configure the Linux device drivers for use with your target hardware
5168 (no, we don't intend to provide a full virtual machine interface to
5171 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5173 Just make sure your machine specific header file (for instance
5174 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5175 Information structure as we define in include/asm-<arch>/u-boot.h,
5176 and make sure that your definition of IMAP_ADDR uses the same value
5177 as your U-Boot configuration in CONFIG_SYS_IMMR.
5180 Configuring the Linux kernel:
5181 -----------------------------
5183 No specific requirements for U-Boot. Make sure you have some root
5184 device (initial ramdisk, NFS) for your target system.
5187 Building a Linux Image:
5188 -----------------------
5190 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5191 not used. If you use recent kernel source, a new build target
5192 "uImage" will exist which automatically builds an image usable by
5193 U-Boot. Most older kernels also have support for a "pImage" target,
5194 which was introduced for our predecessor project PPCBoot and uses a
5195 100% compatible format.
5204 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5205 encapsulate a compressed Linux kernel image with header information,
5206 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5208 * build a standard "vmlinux" kernel image (in ELF binary format):
5210 * convert the kernel into a raw binary image:
5212 ${CROSS_COMPILE}-objcopy -O binary \
5213 -R .note -R .comment \
5214 -S vmlinux linux.bin
5216 * compress the binary image:
5220 * package compressed binary image for U-Boot:
5222 mkimage -A ppc -O linux -T kernel -C gzip \
5223 -a 0 -e 0 -n "Linux Kernel Image" \
5224 -d linux.bin.gz uImage
5227 The "mkimage" tool can also be used to create ramdisk images for use
5228 with U-Boot, either separated from the Linux kernel image, or
5229 combined into one file. "mkimage" encapsulates the images with a 64
5230 byte header containing information about target architecture,
5231 operating system, image type, compression method, entry points, time
5232 stamp, CRC32 checksums, etc.
5234 "mkimage" can be called in two ways: to verify existing images and
5235 print the header information, or to build new images.
5237 In the first form (with "-l" option) mkimage lists the information
5238 contained in the header of an existing U-Boot image; this includes
5239 checksum verification:
5241 tools/mkimage -l image
5242 -l ==> list image header information
5244 The second form (with "-d" option) is used to build a U-Boot image
5245 from a "data file" which is used as image payload:
5247 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5248 -n name -d data_file image
5249 -A ==> set architecture to 'arch'
5250 -O ==> set operating system to 'os'
5251 -T ==> set image type to 'type'
5252 -C ==> set compression type 'comp'
5253 -a ==> set load address to 'addr' (hex)
5254 -e ==> set entry point to 'ep' (hex)
5255 -n ==> set image name to 'name'
5256 -d ==> use image data from 'datafile'
5258 Right now, all Linux kernels for PowerPC systems use the same load
5259 address (0x00000000), but the entry point address depends on the
5262 - 2.2.x kernels have the entry point at 0x0000000C,
5263 - 2.3.x and later kernels have the entry point at 0x00000000.
5265 So a typical call to build a U-Boot image would read:
5267 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5268 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5269 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5270 > examples/uImage.TQM850L
5271 Image Name: 2.4.4 kernel for TQM850L
5272 Created: Wed Jul 19 02:34:59 2000
5273 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5274 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5275 Load Address: 0x00000000
5276 Entry Point: 0x00000000
5278 To verify the contents of the image (or check for corruption):
5280 -> tools/mkimage -l examples/uImage.TQM850L
5281 Image Name: 2.4.4 kernel for TQM850L
5282 Created: Wed Jul 19 02:34:59 2000
5283 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5284 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5285 Load Address: 0x00000000
5286 Entry Point: 0x00000000
5288 NOTE: for embedded systems where boot time is critical you can trade
5289 speed for memory and install an UNCOMPRESSED image instead: this
5290 needs more space in Flash, but boots much faster since it does not
5291 need to be uncompressed:
5293 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5294 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5295 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5296 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5297 > examples/uImage.TQM850L-uncompressed
5298 Image Name: 2.4.4 kernel for TQM850L
5299 Created: Wed Jul 19 02:34:59 2000
5300 Image Type: PowerPC Linux Kernel Image (uncompressed)
5301 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5302 Load Address: 0x00000000
5303 Entry Point: 0x00000000
5306 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5307 when your kernel is intended to use an initial ramdisk:
5309 -> tools/mkimage -n 'Simple Ramdisk Image' \
5310 > -A ppc -O linux -T ramdisk -C gzip \
5311 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5312 Image Name: Simple Ramdisk Image
5313 Created: Wed Jan 12 14:01:50 2000
5314 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5315 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5316 Load Address: 0x00000000
5317 Entry Point: 0x00000000
5319 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5320 option performs the converse operation of the mkimage's second form (the "-d"
5321 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5324 tools/dumpimage -i image -p position data_file
5325 -i ==> extract from the 'image' a specific 'data_file', \
5326 indexed by 'position'
5329 Installing a Linux Image:
5330 -------------------------
5332 To downloading a U-Boot image over the serial (console) interface,
5333 you must convert the image to S-Record format:
5335 objcopy -I binary -O srec examples/image examples/image.srec
5337 The 'objcopy' does not understand the information in the U-Boot
5338 image header, so the resulting S-Record file will be relative to
5339 address 0x00000000. To load it to a given address, you need to
5340 specify the target address as 'offset' parameter with the 'loads'
5343 Example: install the image to address 0x40100000 (which on the
5344 TQM8xxL is in the first Flash bank):
5346 => erase 40100000 401FFFFF
5352 ## Ready for S-Record download ...
5353 ~>examples/image.srec
5354 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5356 15989 15990 15991 15992
5357 [file transfer complete]
5359 ## Start Addr = 0x00000000
5362 You can check the success of the download using the 'iminfo' command;
5363 this includes a checksum verification so you can be sure no data
5364 corruption happened:
5368 ## Checking Image at 40100000 ...
5369 Image Name: 2.2.13 for initrd on TQM850L
5370 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5371 Data Size: 335725 Bytes = 327 kB = 0 MB
5372 Load Address: 00000000
5373 Entry Point: 0000000c
5374 Verifying Checksum ... OK
5380 The "bootm" command is used to boot an application that is stored in
5381 memory (RAM or Flash). In case of a Linux kernel image, the contents
5382 of the "bootargs" environment variable is passed to the kernel as
5383 parameters. You can check and modify this variable using the
5384 "printenv" and "setenv" commands:
5387 => printenv bootargs
5388 bootargs=root=/dev/ram
5390 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5392 => printenv bootargs
5393 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5396 ## Booting Linux kernel at 40020000 ...
5397 Image Name: 2.2.13 for NFS on TQM850L
5398 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5399 Data Size: 381681 Bytes = 372 kB = 0 MB
5400 Load Address: 00000000
5401 Entry Point: 0000000c
5402 Verifying Checksum ... OK
5403 Uncompressing Kernel Image ... OK
5404 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
5405 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5406 time_init: decrementer frequency = 187500000/60
5407 Calibrating delay loop... 49.77 BogoMIPS
5408 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5411 If you want to boot a Linux kernel with initial RAM disk, you pass
5412 the memory addresses of both the kernel and the initrd image (PPBCOOT
5413 format!) to the "bootm" command:
5415 => imi 40100000 40200000
5417 ## Checking Image at 40100000 ...
5418 Image Name: 2.2.13 for initrd on TQM850L
5419 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5420 Data Size: 335725 Bytes = 327 kB = 0 MB
5421 Load Address: 00000000
5422 Entry Point: 0000000c
5423 Verifying Checksum ... OK
5425 ## Checking Image at 40200000 ...
5426 Image Name: Simple Ramdisk Image
5427 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5428 Data Size: 566530 Bytes = 553 kB = 0 MB
5429 Load Address: 00000000
5430 Entry Point: 00000000
5431 Verifying Checksum ... OK
5433 => bootm 40100000 40200000
5434 ## Booting Linux kernel at 40100000 ...
5435 Image Name: 2.2.13 for initrd on TQM850L
5436 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5437 Data Size: 335725 Bytes = 327 kB = 0 MB
5438 Load Address: 00000000
5439 Entry Point: 0000000c
5440 Verifying Checksum ... OK
5441 Uncompressing Kernel Image ... OK
5442 ## Loading RAMDisk Image at 40200000 ...
5443 Image Name: Simple Ramdisk Image
5444 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5445 Data Size: 566530 Bytes = 553 kB = 0 MB
5446 Load Address: 00000000
5447 Entry Point: 00000000
5448 Verifying Checksum ... OK
5449 Loading Ramdisk ... OK
5450 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
5451 Boot arguments: root=/dev/ram
5452 time_init: decrementer frequency = 187500000/60
5453 Calibrating delay loop... 49.77 BogoMIPS
5455 RAMDISK: Compressed image found at block 0
5456 VFS: Mounted root (ext2 filesystem).
5460 Boot Linux and pass a flat device tree:
5463 First, U-Boot must be compiled with the appropriate defines. See the section
5464 titled "Linux Kernel Interface" above for a more in depth explanation. The
5465 following is an example of how to start a kernel and pass an updated
5471 oft=oftrees/mpc8540ads.dtb
5472 => tftp $oftaddr $oft
5473 Speed: 1000, full duplex
5475 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5476 Filename 'oftrees/mpc8540ads.dtb'.
5477 Load address: 0x300000
5480 Bytes transferred = 4106 (100a hex)
5481 => tftp $loadaddr $bootfile
5482 Speed: 1000, full duplex
5484 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5486 Load address: 0x200000
5487 Loading:############
5489 Bytes transferred = 1029407 (fb51f hex)
5494 => bootm $loadaddr - $oftaddr
5495 ## Booting image at 00200000 ...
5496 Image Name: Linux-2.6.17-dirty
5497 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5498 Data Size: 1029343 Bytes = 1005.2 kB
5499 Load Address: 00000000
5500 Entry Point: 00000000
5501 Verifying Checksum ... OK
5502 Uncompressing Kernel Image ... OK
5503 Booting using flat device tree at 0x300000
5504 Using MPC85xx ADS machine description
5505 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5509 More About U-Boot Image Types:
5510 ------------------------------
5512 U-Boot supports the following image types:
5514 "Standalone Programs" are directly runnable in the environment
5515 provided by U-Boot; it is expected that (if they behave
5516 well) you can continue to work in U-Boot after return from
5517 the Standalone Program.
5518 "OS Kernel Images" are usually images of some Embedded OS which
5519 will take over control completely. Usually these programs
5520 will install their own set of exception handlers, device
5521 drivers, set up the MMU, etc. - this means, that you cannot
5522 expect to re-enter U-Boot except by resetting the CPU.
5523 "RAMDisk Images" are more or less just data blocks, and their
5524 parameters (address, size) are passed to an OS kernel that is
5526 "Multi-File Images" contain several images, typically an OS
5527 (Linux) kernel image and one or more data images like
5528 RAMDisks. This construct is useful for instance when you want
5529 to boot over the network using BOOTP etc., where the boot
5530 server provides just a single image file, but you want to get
5531 for instance an OS kernel and a RAMDisk image.
5533 "Multi-File Images" start with a list of image sizes, each
5534 image size (in bytes) specified by an "uint32_t" in network
5535 byte order. This list is terminated by an "(uint32_t)0".
5536 Immediately after the terminating 0 follow the images, one by
5537 one, all aligned on "uint32_t" boundaries (size rounded up to
5538 a multiple of 4 bytes).
5540 "Firmware Images" are binary images containing firmware (like
5541 U-Boot or FPGA images) which usually will be programmed to
5544 "Script files" are command sequences that will be executed by
5545 U-Boot's command interpreter; this feature is especially
5546 useful when you configure U-Boot to use a real shell (hush)
5547 as command interpreter.
5549 Booting the Linux zImage:
5550 -------------------------
5552 On some platforms, it's possible to boot Linux zImage. This is done
5553 using the "bootz" command. The syntax of "bootz" command is the same
5554 as the syntax of "bootm" command.
5556 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5557 kernel with raw initrd images. The syntax is slightly different, the
5558 address of the initrd must be augmented by it's size, in the following
5559 format: "<initrd addres>:<initrd size>".
5565 One of the features of U-Boot is that you can dynamically load and
5566 run "standalone" applications, which can use some resources of
5567 U-Boot like console I/O functions or interrupt services.
5569 Two simple examples are included with the sources:
5574 'examples/hello_world.c' contains a small "Hello World" Demo
5575 application; it is automatically compiled when you build U-Boot.
5576 It's configured to run at address 0x00040004, so you can play with it
5580 ## Ready for S-Record download ...
5581 ~>examples/hello_world.srec
5582 1 2 3 4 5 6 7 8 9 10 11 ...
5583 [file transfer complete]
5585 ## Start Addr = 0x00040004
5587 => go 40004 Hello World! This is a test.
5588 ## Starting application at 0x00040004 ...
5599 Hit any key to exit ...
5601 ## Application terminated, rc = 0x0
5603 Another example, which demonstrates how to register a CPM interrupt
5604 handler with the U-Boot code, can be found in 'examples/timer.c'.
5605 Here, a CPM timer is set up to generate an interrupt every second.
5606 The interrupt service routine is trivial, just printing a '.'
5607 character, but this is just a demo program. The application can be
5608 controlled by the following keys:
5610 ? - print current values og the CPM Timer registers
5611 b - enable interrupts and start timer
5612 e - stop timer and disable interrupts
5613 q - quit application
5616 ## Ready for S-Record download ...
5617 ~>examples/timer.srec
5618 1 2 3 4 5 6 7 8 9 10 11 ...
5619 [file transfer complete]
5621 ## Start Addr = 0x00040004
5624 ## Starting application at 0x00040004 ...
5627 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5630 [q, b, e, ?] Set interval 1000000 us
5633 [q, b, e, ?] ........
5634 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5637 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5640 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5643 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5645 [q, b, e, ?] ...Stopping timer
5647 [q, b, e, ?] ## Application terminated, rc = 0x0
5653 Over time, many people have reported problems when trying to use the
5654 "minicom" terminal emulation program for serial download. I (wd)
5655 consider minicom to be broken, and recommend not to use it. Under
5656 Unix, I recommend to use C-Kermit for general purpose use (and
5657 especially for kermit binary protocol download ("loadb" command), and
5658 use "cu" for S-Record download ("loads" command). See
5659 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5660 for help with kermit.
5663 Nevertheless, if you absolutely want to use it try adding this
5664 configuration to your "File transfer protocols" section:
5666 Name Program Name U/D FullScr IO-Red. Multi
5667 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5668 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5674 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5675 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5677 Building requires a cross environment; it is known to work on
5678 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5679 need gmake since the Makefiles are not compatible with BSD make).
5680 Note that the cross-powerpc package does not install include files;
5681 attempting to build U-Boot will fail because <machine/ansi.h> is
5682 missing. This file has to be installed and patched manually:
5684 # cd /usr/pkg/cross/powerpc-netbsd/include
5686 # ln -s powerpc machine
5687 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5688 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5690 Native builds *don't* work due to incompatibilities between native
5691 and U-Boot include files.
5693 Booting assumes that (the first part of) the image booted is a
5694 stage-2 loader which in turn loads and then invokes the kernel
5695 proper. Loader sources will eventually appear in the NetBSD source
5696 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5697 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5700 Implementation Internals:
5701 =========================
5703 The following is not intended to be a complete description of every
5704 implementation detail. However, it should help to understand the
5705 inner workings of U-Boot and make it easier to port it to custom
5709 Initial Stack, Global Data:
5710 ---------------------------
5712 The implementation of U-Boot is complicated by the fact that U-Boot
5713 starts running out of ROM (flash memory), usually without access to
5714 system RAM (because the memory controller is not initialized yet).
5715 This means that we don't have writable Data or BSS segments, and BSS
5716 is not initialized as zero. To be able to get a C environment working
5717 at all, we have to allocate at least a minimal stack. Implementation
5718 options for this are defined and restricted by the CPU used: Some CPU
5719 models provide on-chip memory (like the IMMR area on MPC8xx and
5720 MPC826x processors), on others (parts of) the data cache can be
5721 locked as (mis-) used as memory, etc.
5723 Chris Hallinan posted a good summary of these issues to the
5724 U-Boot mailing list:
5726 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5727 From: "Chris Hallinan" <clh@net1plus.com>
5728 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5731 Correct me if I'm wrong, folks, but the way I understand it
5732 is this: Using DCACHE as initial RAM for Stack, etc, does not
5733 require any physical RAM backing up the cache. The cleverness
5734 is that the cache is being used as a temporary supply of
5735 necessary storage before the SDRAM controller is setup. It's
5736 beyond the scope of this list to explain the details, but you
5737 can see how this works by studying the cache architecture and
5738 operation in the architecture and processor-specific manuals.
5740 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5741 is another option for the system designer to use as an
5742 initial stack/RAM area prior to SDRAM being available. Either
5743 option should work for you. Using CS 4 should be fine if your
5744 board designers haven't used it for something that would
5745 cause you grief during the initial boot! It is frequently not
5748 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5749 with your processor/board/system design. The default value
5750 you will find in any recent u-boot distribution in
5751 walnut.h should work for you. I'd set it to a value larger
5752 than your SDRAM module. If you have a 64MB SDRAM module, set
5753 it above 400_0000. Just make sure your board has no resources
5754 that are supposed to respond to that address! That code in
5755 start.S has been around a while and should work as is when
5756 you get the config right.
5761 It is essential to remember this, since it has some impact on the C
5762 code for the initialization procedures:
5764 * Initialized global data (data segment) is read-only. Do not attempt
5767 * Do not use any uninitialized global data (or implicitely initialized
5768 as zero data - BSS segment) at all - this is undefined, initiali-
5769 zation is performed later (when relocating to RAM).
5771 * Stack space is very limited. Avoid big data buffers or things like
5774 Having only the stack as writable memory limits means we cannot use
5775 normal global data to share information beween the code. But it
5776 turned out that the implementation of U-Boot can be greatly
5777 simplified by making a global data structure (gd_t) available to all
5778 functions. We could pass a pointer to this data as argument to _all_
5779 functions, but this would bloat the code. Instead we use a feature of
5780 the GCC compiler (Global Register Variables) to share the data: we
5781 place a pointer (gd) to the global data into a register which we
5782 reserve for this purpose.
5784 When choosing a register for such a purpose we are restricted by the
5785 relevant (E)ABI specifications for the current architecture, and by
5786 GCC's implementation.
5788 For PowerPC, the following registers have specific use:
5790 R2: reserved for system use
5791 R3-R4: parameter passing and return values
5792 R5-R10: parameter passing
5793 R13: small data area pointer
5797 (U-Boot also uses R12 as internal GOT pointer. r12
5798 is a volatile register so r12 needs to be reset when
5799 going back and forth between asm and C)
5801 ==> U-Boot will use R2 to hold a pointer to the global data
5803 Note: on PPC, we could use a static initializer (since the
5804 address of the global data structure is known at compile time),
5805 but it turned out that reserving a register results in somewhat
5806 smaller code - although the code savings are not that big (on
5807 average for all boards 752 bytes for the whole U-Boot image,
5808 624 text + 127 data).
5810 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5811 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5813 ==> U-Boot will use P3 to hold a pointer to the global data
5815 On ARM, the following registers are used:
5817 R0: function argument word/integer result
5818 R1-R3: function argument word
5819 R9: platform specific
5820 R10: stack limit (used only if stack checking is enabled)
5821 R11: argument (frame) pointer
5822 R12: temporary workspace
5825 R15: program counter
5827 ==> U-Boot will use R9 to hold a pointer to the global data
5829 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5831 On Nios II, the ABI is documented here:
5832 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5834 ==> U-Boot will use gp to hold a pointer to the global data
5836 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5837 to access small data sections, so gp is free.
5839 On NDS32, the following registers are used:
5841 R0-R1: argument/return
5843 R15: temporary register for assembler
5844 R16: trampoline register
5845 R28: frame pointer (FP)
5846 R29: global pointer (GP)
5847 R30: link register (LP)
5848 R31: stack pointer (SP)
5849 PC: program counter (PC)
5851 ==> U-Boot will use R10 to hold a pointer to the global data
5853 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5854 or current versions of GCC may "optimize" the code too much.
5859 U-Boot runs in system state and uses physical addresses, i.e. the
5860 MMU is not used either for address mapping nor for memory protection.
5862 The available memory is mapped to fixed addresses using the memory
5863 controller. In this process, a contiguous block is formed for each
5864 memory type (Flash, SDRAM, SRAM), even when it consists of several
5865 physical memory banks.
5867 U-Boot is installed in the first 128 kB of the first Flash bank (on
5868 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5869 booting and sizing and initializing DRAM, the code relocates itself
5870 to the upper end of DRAM. Immediately below the U-Boot code some
5871 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5872 configuration setting]. Below that, a structure with global Board
5873 Info data is placed, followed by the stack (growing downward).
5875 Additionally, some exception handler code is copied to the low 8 kB
5876 of DRAM (0x00000000 ... 0x00001FFF).
5878 So a typical memory configuration with 16 MB of DRAM could look like
5881 0x0000 0000 Exception Vector code
5884 0x0000 2000 Free for Application Use
5890 0x00FB FF20 Monitor Stack (Growing downward)
5891 0x00FB FFAC Board Info Data and permanent copy of global data
5892 0x00FC 0000 Malloc Arena
5895 0x00FE 0000 RAM Copy of Monitor Code
5896 ... eventually: LCD or video framebuffer
5897 ... eventually: pRAM (Protected RAM - unchanged by reset)
5898 0x00FF FFFF [End of RAM]
5901 System Initialization:
5902 ----------------------
5904 In the reset configuration, U-Boot starts at the reset entry point
5905 (on most PowerPC systems at address 0x00000100). Because of the reset
5906 configuration for CS0# this is a mirror of the onboard Flash memory.
5907 To be able to re-map memory U-Boot then jumps to its link address.
5908 To be able to implement the initialization code in C, a (small!)
5909 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5910 which provide such a feature like MPC8xx or MPC8260), or in a locked
5911 part of the data cache. After that, U-Boot initializes the CPU core,
5912 the caches and the SIU.
5914 Next, all (potentially) available memory banks are mapped using a
5915 preliminary mapping. For example, we put them on 512 MB boundaries
5916 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5917 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5918 programmed for SDRAM access. Using the temporary configuration, a
5919 simple memory test is run that determines the size of the SDRAM
5922 When there is more than one SDRAM bank, and the banks are of
5923 different size, the largest is mapped first. For equal size, the first
5924 bank (CS2#) is mapped first. The first mapping is always for address
5925 0x00000000, with any additional banks following immediately to create
5926 contiguous memory starting from 0.
5928 Then, the monitor installs itself at the upper end of the SDRAM area
5929 and allocates memory for use by malloc() and for the global Board
5930 Info data; also, the exception vector code is copied to the low RAM
5931 pages, and the final stack is set up.
5933 Only after this relocation will you have a "normal" C environment;
5934 until that you are restricted in several ways, mostly because you are
5935 running from ROM, and because the code will have to be relocated to a
5939 U-Boot Porting Guide:
5940 ----------------------
5942 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5946 int main(int argc, char *argv[])
5948 sighandler_t no_more_time;
5950 signal(SIGALRM, no_more_time);
5951 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5953 if (available_money > available_manpower) {
5954 Pay consultant to port U-Boot;
5958 Download latest U-Boot source;
5960 Subscribe to u-boot mailing list;
5963 email("Hi, I am new to U-Boot, how do I get started?");
5966 Read the README file in the top level directory;
5967 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5968 Read applicable doc/*.README;
5969 Read the source, Luke;
5970 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5973 if (available_money > toLocalCurrency ($2500))
5976 Add a lot of aggravation and time;
5978 if (a similar board exists) { /* hopefully... */
5979 cp -a board/<similar> board/<myboard>
5980 cp include/configs/<similar>.h include/configs/<myboard>.h
5982 Create your own board support subdirectory;
5983 Create your own board include/configs/<myboard>.h file;
5985 Edit new board/<myboard> files
5986 Edit new include/configs/<myboard>.h
5991 Add / modify source code;
5995 email("Hi, I am having problems...");
5997 Send patch file to the U-Boot email list;
5998 if (reasonable critiques)
5999 Incorporate improvements from email list code review;
6001 Defend code as written;
6007 void no_more_time (int sig)
6016 All contributions to U-Boot should conform to the Linux kernel
6017 coding style; see the file "Documentation/CodingStyle" and the script
6018 "scripts/Lindent" in your Linux kernel source directory.
6020 Source files originating from a different project (for example the
6021 MTD subsystem) are generally exempt from these guidelines and are not
6022 reformated to ease subsequent migration to newer versions of those
6025 Please note that U-Boot is implemented in C (and to some small parts in
6026 Assembler); no C++ is used, so please do not use C++ style comments (//)
6029 Please also stick to the following formatting rules:
6030 - remove any trailing white space
6031 - use TAB characters for indentation and vertical alignment, not spaces
6032 - make sure NOT to use DOS '\r\n' line feeds
6033 - do not add more than 2 consecutive empty lines to source files
6034 - do not add trailing empty lines to source files
6036 Submissions which do not conform to the standards may be returned
6037 with a request to reformat the changes.
6043 Since the number of patches for U-Boot is growing, we need to
6044 establish some rules. Submissions which do not conform to these rules
6045 may be rejected, even when they contain important and valuable stuff.
6047 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6049 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6050 see http://lists.denx.de/mailman/listinfo/u-boot
6052 When you send a patch, please include the following information with
6055 * For bug fixes: a description of the bug and how your patch fixes
6056 this bug. Please try to include a way of demonstrating that the
6057 patch actually fixes something.
6059 * For new features: a description of the feature and your
6062 * A CHANGELOG entry as plaintext (separate from the patch)
6064 * For major contributions, your entry to the CREDITS file
6066 * When you add support for a new board, don't forget to add a
6067 maintainer e-mail address to the boards.cfg file, too.
6069 * If your patch adds new configuration options, don't forget to
6070 document these in the README file.
6072 * The patch itself. If you are using git (which is *strongly*
6073 recommended) you can easily generate the patch using the
6074 "git format-patch". If you then use "git send-email" to send it to
6075 the U-Boot mailing list, you will avoid most of the common problems
6076 with some other mail clients.
6078 If you cannot use git, use "diff -purN OLD NEW". If your version of
6079 diff does not support these options, then get the latest version of
6082 The current directory when running this command shall be the parent
6083 directory of the U-Boot source tree (i. e. please make sure that
6084 your patch includes sufficient directory information for the
6087 We prefer patches as plain text. MIME attachments are discouraged,
6088 and compressed attachments must not be used.
6090 * If one logical set of modifications affects or creates several
6091 files, all these changes shall be submitted in a SINGLE patch file.
6093 * Changesets that contain different, unrelated modifications shall be
6094 submitted as SEPARATE patches, one patch per changeset.
6099 * Before sending the patch, run the MAKEALL script on your patched
6100 source tree and make sure that no errors or warnings are reported
6101 for any of the boards.
6103 * Keep your modifications to the necessary minimum: A patch
6104 containing several unrelated changes or arbitrary reformats will be
6105 returned with a request to re-formatting / split it.
6107 * If you modify existing code, make sure that your new code does not
6108 add to the memory footprint of the code ;-) Small is beautiful!
6109 When adding new features, these should compile conditionally only
6110 (using #ifdef), and the resulting code with the new feature
6111 disabled must not need more memory than the old code without your
6114 * Remember that there is a size limit of 100 kB per message on the
6115 u-boot mailing list. Bigger patches will be moderated. If they are
6116 reasonable and not too big, they will be acknowledged. But patches
6117 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob