1 #
2 # (C) Copyright 2000 - 2012
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 #
5 # See file CREDITS for list of people who contributed to this
6 # project.
7 #
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
12 #
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
17 #
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 # MA 02111-1307 USA
22 #
24 Summary:
25 ========
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
31 code.
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
46 Status:
47 =======
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
55 maintainers.
58 Where to get help:
59 ==================
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
79 directory.
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
85 Where we come from:
86 ===================
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
90 - clean up code
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
95 * S-Record download
96 * network boot
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
104 Names and Spelling:
105 ===================
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
126 Versioning:
127 ===========
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
136 Examples:
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
142 Directory Hierarchy:
143 ====================
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /mips32 Files specific to MIPS32 CPUs
184 /xburst Files specific to Ingenic XBurst CPUs
185 /lib Architecture specific library files
186 /nds32 Files generic to NDS32 architecture
187 /cpu CPU specific files
188 /n1213 Files specific to Andes Technology N1213 CPUs
189 /lib Architecture specific library files
190 /nios2 Files generic to Altera NIOS2 architecture
191 /cpu CPU specific files
192 /lib Architecture specific library files
193 /powerpc Files generic to PowerPC architecture
194 /cpu CPU specific files
195 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
196 /mpc5xx Files specific to Freescale MPC5xx CPUs
197 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
198 /mpc8xx Files specific to Freescale MPC8xx CPUs
199 /mpc8220 Files specific to Freescale MPC8220 CPUs
200 /mpc824x Files specific to Freescale MPC824x CPUs
201 /mpc8260 Files specific to Freescale MPC8260 CPUs
202 /mpc85xx Files specific to Freescale MPC85xx CPUs
203 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
204 /lib Architecture specific library files
205 /sh Files generic to SH architecture
206 /cpu CPU specific files
207 /sh2 Files specific to sh2 CPUs
208 /sh3 Files specific to sh3 CPUs
209 /sh4 Files specific to sh4 CPUs
210 /lib Architecture specific library files
211 /sparc Files generic to SPARC architecture
212 /cpu CPU specific files
213 /leon2 Files specific to Gaisler LEON2 SPARC CPU
214 /leon3 Files specific to Gaisler LEON3 SPARC CPU
215 /lib Architecture specific library files
216 /api Machine/arch independent API for external apps
217 /board Board dependent files
218 /common Misc architecture independent functions
219 /disk Code for disk drive partition handling
220 /doc Documentation (don't expect too much)
221 /drivers Commonly used device drivers
222 /examples Example code for standalone applications, etc.
223 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
224 /include Header Files
225 /lib Files generic to all architectures
226 /libfdt Library files to support flattened device trees
227 /lzma Library files to support LZMA decompression
228 /lzo Library files to support LZO decompression
229 /net Networking code
230 /post Power On Self Test
231 /rtc Real Time Clock drivers
232 /tools Tools to build S-Record or U-Boot images, etc.
234 Software Configuration:
235 =======================
237 Configuration is usually done using C preprocessor defines; the
238 rationale behind that is to avoid dead code whenever possible.
240 There are two classes of configuration variables:
242 * Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
244 "CONFIG_".
246 * Configuration _SETTINGS_:
247 These depend on the hardware etc. and should not be meddled with if
248 you don't know what you're doing; they have names beginning with
249 "CONFIG_SYS_".
251 Later we will add a configuration tool - probably similar to or even
252 identical to what's used for the Linux kernel. Right now, we have to
253 do the configuration by hand, which means creating some symbolic
254 links and editing some configuration files. We use the TQM8xxL boards
255 as an example here.
258 Selection of Processor Architecture and Board Type:
259 ---------------------------------------------------
261 For all supported boards there are ready-to-use default
262 configurations available; just type "make <board_name>_config".
264 Example: For a TQM823L module type:
266 cd u-boot
267 make TQM823L_config
269 For the Cogent platform, you need to specify the CPU type as well;
270 e.g. "make cogent_mpc8xx_config". And also configure the cogent
271 directory according to the instructions in cogent/README.
274 Configuration Options:
275 ----------------------
277 Configuration depends on the combination of board and CPU type; all
278 such information is kept in a configuration file
279 "include/configs/<board_name>.h".
281 Example: For a TQM823L module, all configuration settings are in
282 "include/configs/TQM823L.h".
285 Many of the options are named exactly as the corresponding Linux
286 kernel configuration options. The intention is to make it easier to
287 build a config tool - later.
290 The following options need to be configured:
292 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
294 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
296 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
297 Define exactly one, e.g. CONFIG_ATSTK1002
299 - CPU Module Type: (if CONFIG_COGENT is defined)
300 Define exactly one of
301 CONFIG_CMA286_60_OLD
302 --- FIXME --- not tested yet:
303 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
304 CONFIG_CMA287_23, CONFIG_CMA287_50
306 - Motherboard Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
308 CONFIG_CMA101, CONFIG_CMA102
310 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
311 Define one or more of
312 CONFIG_CMA302
314 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
315 Define one or more of
316 CONFIG_LCD_HEARTBEAT - update a character position on
317 the LCD display every second with
318 a "rotator" |\-/|\-/
320 - Board flavour: (if CONFIG_MPC8260ADS is defined)
321 CONFIG_ADSTYPE
322 Possible values are:
323 CONFIG_SYS_8260ADS - original MPC8260ADS
324 CONFIG_SYS_8266ADS - MPC8266ADS
325 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
326 CONFIG_SYS_8272ADS - MPC8272ADS
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
333 - MPC824X Family Member (if CONFIG_MPC824X is defined)
334 Define exactly one of
335 CONFIG_MPC8240, CONFIG_MPC8245
337 - 8xx CPU Options: (if using an MPC8xx CPU)
338 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
339 get_gclk_freq() cannot work
340 e.g. if there is no 32KHz
341 reference PIT/RTC clock
342 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
343 or XTAL/EXTAL)
345 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
346 CONFIG_SYS_8xx_CPUCLK_MIN
347 CONFIG_SYS_8xx_CPUCLK_MAX
348 CONFIG_8xx_CPUCLK_DEFAULT
349 See doc/README.MPC866
351 CONFIG_SYS_MEASURE_CPUCLK
353 Define this to measure the actual CPU clock instead
354 of relying on the correctness of the configured
355 values. Mostly useful for board bringup to make sure
356 the PLL is locked at the intended frequency. Note
357 that this requires a (stable) reference clock (32 kHz
358 RTC clock or CONFIG_SYS_8XX_XIN)
360 CONFIG_SYS_DELAYED_ICACHE
362 Define this option if you want to enable the
363 ICache only when Code runs from RAM.
365 - 85xx CPU Options:
366 CONFIG_SYS_PPC64
368 Specifies that the core is a 64-bit PowerPC implementation (implements
369 the "64" category of the Power ISA). This is necessary for ePAPR
370 compliance, among other possible reasons.
372 CONFIG_SYS_FSL_TBCLK_DIV
374 Defines the core time base clock divider ratio compared to the
375 system clock. On most PQ3 devices this is 8, on newer QorIQ
376 devices it can be 16 or 32. The ratio varies from SoC to Soc.
378 CONFIG_SYS_FSL_PCIE_COMPAT
380 Defines the string to utilize when trying to match PCIe device
381 tree nodes for the given platform.
383 CONFIG_SYS_PPC_E500_DEBUG_TLB
385 Enables a temporary TLB entry to be used during boot to work
386 around limitations in e500v1 and e500v2 external debugger
387 support. This reduces the portions of the boot code where
388 breakpoints and single stepping do not work. The value of this
389 symbol should be set to the TLB1 entry to be used for this
390 purpose.
392 CONFIG_SYS_FSL_ERRATUM_A004510
394 Enables a workaround for erratum A004510. If set,
395 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
396 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
398 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
399 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
401 Defines one or two SoC revisions (low 8 bits of SVR)
402 for which the A004510 workaround should be applied.
404 The rest of SVR is either not relevant to the decision
405 of whether the erratum is present (e.g. p2040 versus
406 p2041) or is implied by the build target, which controls
407 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
409 See Freescale App Note 4493 for more information about
410 this erratum.
412 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
414 This is the value to write into CCSR offset 0x18600
415 according to the A004510 workaround.
417 - Generic CPU options:
418 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
420 Defines the endianess of the CPU. Implementation of those
421 values is arch specific.
423 - Intel Monahans options:
424 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
426 Defines the Monahans run mode to oscillator
427 ratio. Valid values are 8, 16, 24, 31. The core
428 frequency is this value multiplied by 13 MHz.
430 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
432 Defines the Monahans turbo mode to oscillator
433 ratio. Valid values are 1 (default if undefined) and
434 2. The core frequency as calculated above is multiplied
435 by this value.
437 - MIPS CPU options:
438 CONFIG_SYS_INIT_SP_OFFSET
440 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
441 pointer. This is needed for the temporary stack before
442 relocation.
444 CONFIG_SYS_MIPS_CACHE_MODE
446 Cache operation mode for the MIPS CPU.
447 See also arch/mips/include/asm/mipsregs.h.
448 Possible values are:
449 CONF_CM_CACHABLE_NO_WA
450 CONF_CM_CACHABLE_WA
451 CONF_CM_UNCACHED
452 CONF_CM_CACHABLE_NONCOHERENT
453 CONF_CM_CACHABLE_CE
454 CONF_CM_CACHABLE_COW
455 CONF_CM_CACHABLE_CUW
456 CONF_CM_CACHABLE_ACCELERATED
458 CONFIG_SYS_XWAY_EBU_BOOTCFG
460 Special option for Lantiq XWAY SoCs for booting from NOR flash.
461 See also arch/mips/cpu/mips32/start.S.
463 CONFIG_XWAY_SWAP_BYTES
465 Enable compilation of tools/xway-swap-bytes needed for Lantiq
466 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
467 be swapped if a flash programmer is used.
469 - ARM options:
470 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
472 Select high exception vectors of the ARM core, e.g., do not
473 clear the V bit of the c1 register of CP15.
475 CONFIG_SYS_THUMB_BUILD
477 Use this flag to build U-Boot using the Thumb instruction
478 set for ARM architectures. Thumb instruction set provides
479 better code density. For ARM architectures that support
480 Thumb2 this flag will result in Thumb2 code generated by
481 GCC.
483 - Linux Kernel Interface:
484 CONFIG_CLOCKS_IN_MHZ
486 U-Boot stores all clock information in Hz
487 internally. For binary compatibility with older Linux
488 kernels (which expect the clocks passed in the
489 bd_info data to be in MHz) the environment variable
490 "clocks_in_mhz" can be defined so that U-Boot
491 converts clock data to MHZ before passing it to the
492 Linux kernel.
493 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
494 "clocks_in_mhz=1" is automatically included in the
495 default environment.
497 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
499 When transferring memsize parameter to linux, some versions
500 expect it to be in bytes, others in MB.
501 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
503 CONFIG_OF_LIBFDT
505 New kernel versions are expecting firmware settings to be
506 passed using flattened device trees (based on open firmware
507 concepts).
509 CONFIG_OF_LIBFDT
510 * New libfdt-based support
511 * Adds the "fdt" command
512 * The bootm command automatically updates the fdt
514 OF_CPU - The proper name of the cpus node (only required for
515 MPC512X and MPC5xxx based boards).
516 OF_SOC - The proper name of the soc node (only required for
517 MPC512X and MPC5xxx based boards).
518 OF_TBCLK - The timebase frequency.
519 OF_STDOUT_PATH - The path to the console device
521 boards with QUICC Engines require OF_QE to set UCC MAC
522 addresses
524 CONFIG_OF_BOARD_SETUP
526 Board code has addition modification that it wants to make
527 to the flat device tree before handing it off to the kernel
529 CONFIG_OF_BOOT_CPU
531 This define fills in the correct boot CPU in the boot
532 param header, the default value is zero if undefined.
534 CONFIG_OF_IDE_FIXUP
536 U-Boot can detect if an IDE device is present or not.
537 If not, and this new config option is activated, U-Boot
538 removes the ATA node from the DTS before booting Linux,
539 so the Linux IDE driver does not probe the device and
540 crash. This is needed for buggy hardware (uc101) where
541 no pull down resistor is connected to the signal IDE5V_DD7.
543 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
545 This setting is mandatory for all boards that have only one
546 machine type and must be used to specify the machine type
547 number as it appears in the ARM machine registry
548 (see http://www.arm.linux.org.uk/developer/machines/).
549 Only boards that have multiple machine types supported
550 in a single configuration file and the machine type is
551 runtime discoverable, do not have to use this setting.
553 - vxWorks boot parameters:
555 bootvx constructs a valid bootline using the following
556 environments variables: bootfile, ipaddr, serverip, hostname.
557 It loads the vxWorks image pointed bootfile.
559 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
560 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
561 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
562 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
564 CONFIG_SYS_VXWORKS_ADD_PARAMS
566 Add it at the end of the bootline. E.g "u=username pw=secret"
568 Note: If a "bootargs" environment is defined, it will overwride
569 the defaults discussed just above.
571 - Cache Configuration:
572 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
573 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
574 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
576 - Cache Configuration for ARM:
577 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
578 controller
579 CONFIG_SYS_PL310_BASE - Physical base address of PL310
580 controller register space
582 - Serial Ports:
583 CONFIG_PL010_SERIAL
585 Define this if you want support for Amba PrimeCell PL010 UARTs.
587 CONFIG_PL011_SERIAL
589 Define this if you want support for Amba PrimeCell PL011 UARTs.
591 CONFIG_PL011_CLOCK
593 If you have Amba PrimeCell PL011 UARTs, set this variable to
594 the clock speed of the UARTs.
596 CONFIG_PL01x_PORTS
598 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
599 define this to a list of base addresses for each (supported)
600 port. See e.g. include/configs/versatile.h
602 CONFIG_PL011_SERIAL_RLCR
604 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
605 have separate receive and transmit line control registers. Set
606 this variable to initialize the extra register.
608 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
610 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
611 boot loader that has already initialized the UART. Define this
612 variable to flush the UART at init time.
615 - Console Interface:
616 Depending on board, define exactly one serial port
617 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
618 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
619 console by defining CONFIG_8xx_CONS_NONE
621 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
622 port routines must be defined elsewhere
623 (i.e. serial_init(), serial_getc(), ...)
625 CONFIG_CFB_CONSOLE
626 Enables console device for a color framebuffer. Needs following
627 defines (cf. smiLynxEM, i8042)
628 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
629 (default big endian)
630 VIDEO_HW_RECTFILL graphic chip supports
631 rectangle fill
632 (cf. smiLynxEM)
633 VIDEO_HW_BITBLT graphic chip supports
634 bit-blit (cf. smiLynxEM)
635 VIDEO_VISIBLE_COLS visible pixel columns
636 (cols=pitch)
637 VIDEO_VISIBLE_ROWS visible pixel rows
638 VIDEO_PIXEL_SIZE bytes per pixel
639 VIDEO_DATA_FORMAT graphic data format
640 (0-5, cf. cfb_console.c)
641 VIDEO_FB_ADRS framebuffer address
642 VIDEO_KBD_INIT_FCT keyboard int fct
643 (i.e. i8042_kbd_init())
644 VIDEO_TSTC_FCT test char fct
645 (i.e. i8042_tstc)
646 VIDEO_GETC_FCT get char fct
647 (i.e. i8042_getc)
648 CONFIG_CONSOLE_CURSOR cursor drawing on/off
649 (requires blink timer
650 cf. i8042.c)
651 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
652 CONFIG_CONSOLE_TIME display time/date info in
653 upper right corner
654 (requires CONFIG_CMD_DATE)
655 CONFIG_VIDEO_LOGO display Linux logo in
656 upper left corner
657 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
658 linux_logo.h for logo.
659 Requires CONFIG_VIDEO_LOGO
660 CONFIG_CONSOLE_EXTRA_INFO
661 additional board info beside
662 the logo
664 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
665 a limited number of ANSI escape sequences (cursor control,
666 erase functions and limited graphics rendition control).
668 When CONFIG_CFB_CONSOLE is defined, video console is
669 default i/o. Serial console can be forced with
670 environment 'console=serial'.
672 When CONFIG_SILENT_CONSOLE is defined, all console
673 messages (by U-Boot and Linux!) can be silenced with
674 the "silent" environment variable. See
675 doc/README.silent for more information.
677 - Console Baudrate:
678 CONFIG_BAUDRATE - in bps
679 Select one of the baudrates listed in
680 CONFIG_SYS_BAUDRATE_TABLE, see below.
681 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
683 - Console Rx buffer length
684 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
685 the maximum receive buffer length for the SMC.
686 This option is actual only for 82xx and 8xx possible.
687 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
688 must be defined, to setup the maximum idle timeout for
689 the SMC.
691 - Pre-Console Buffer:
692 Prior to the console being initialised (i.e. serial UART
693 initialised etc) all console output is silently discarded.
694 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
695 buffer any console messages prior to the console being
696 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
697 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
698 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
699 bytes are output before the console is initialised, the
700 earlier bytes are discarded.
702 'Sane' compilers will generate smaller code if
703 CONFIG_PRE_CON_BUF_SZ is a power of 2
705 - Safe printf() functions
706 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
707 the printf() functions. These are defined in
708 include/vsprintf.h and include snprintf(), vsnprintf() and
709 so on. Code size increase is approximately 300-500 bytes.
710 If this option is not given then these functions will
711 silently discard their buffer size argument - this means
712 you are not getting any overflow checking in this case.
714 - Boot Delay: CONFIG_BOOTDELAY - in seconds
715 Delay before automatically booting the default image;
716 set to -1 to disable autoboot.
717 set to -2 to autoboot with no delay and not check for abort
718 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
720 See doc/README.autoboot for these options that
721 work with CONFIG_BOOTDELAY. None are required.
722 CONFIG_BOOT_RETRY_TIME
723 CONFIG_BOOT_RETRY_MIN
724 CONFIG_AUTOBOOT_KEYED
725 CONFIG_AUTOBOOT_PROMPT
726 CONFIG_AUTOBOOT_DELAY_STR
727 CONFIG_AUTOBOOT_STOP_STR
728 CONFIG_AUTOBOOT_DELAY_STR2
729 CONFIG_AUTOBOOT_STOP_STR2
730 CONFIG_ZERO_BOOTDELAY_CHECK
731 CONFIG_RESET_TO_RETRY
733 - Autoboot Command:
734 CONFIG_BOOTCOMMAND
735 Only needed when CONFIG_BOOTDELAY is enabled;
736 define a command string that is automatically executed
737 when no character is read on the console interface
738 within "Boot Delay" after reset.
740 CONFIG_BOOTARGS
741 This can be used to pass arguments to the bootm
742 command. The value of CONFIG_BOOTARGS goes into the
743 environment value "bootargs".
745 CONFIG_RAMBOOT and CONFIG_NFSBOOT
746 The value of these goes into the environment as
747 "ramboot" and "nfsboot" respectively, and can be used
748 as a convenience, when switching between booting from
749 RAM and NFS.
751 - Pre-Boot Commands:
752 CONFIG_PREBOOT
754 When this option is #defined, the existence of the
755 environment variable "preboot" will be checked
756 immediately before starting the CONFIG_BOOTDELAY
757 countdown and/or running the auto-boot command resp.
758 entering interactive mode.
760 This feature is especially useful when "preboot" is
761 automatically generated or modified. For an example
762 see the LWMON board specific code: here "preboot" is
763 modified when the user holds down a certain
764 combination of keys on the (special) keyboard when
765 booting the systems
767 - Serial Download Echo Mode:
768 CONFIG_LOADS_ECHO
769 If defined to 1, all characters received during a
770 serial download (using the "loads" command) are
771 echoed back. This might be needed by some terminal
772 emulations (like "cu"), but may as well just take
773 time on others. This setting #define's the initial
774 value of the "loads_echo" environment variable.
776 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
777 CONFIG_KGDB_BAUDRATE
778 Select one of the baudrates listed in
779 CONFIG_SYS_BAUDRATE_TABLE, see below.
781 - Monitor Functions:
782 Monitor commands can be included or excluded
783 from the build by using the #include files
784 <config_cmd_all.h> and #undef'ing unwanted
785 commands, or using <config_cmd_default.h>
786 and augmenting with additional #define's
787 for wanted commands.
789 The default command configuration includes all commands
790 except those marked below with a "*".
792 CONFIG_CMD_ASKENV * ask for env variable
793 CONFIG_CMD_BDI bdinfo
794 CONFIG_CMD_BEDBUG * Include BedBug Debugger
795 CONFIG_CMD_BMP * BMP support
796 CONFIG_CMD_BSP * Board specific commands
797 CONFIG_CMD_BOOTD bootd
798 CONFIG_CMD_CACHE * icache, dcache
799 CONFIG_CMD_CONSOLE coninfo
800 CONFIG_CMD_CRC32 * crc32
801 CONFIG_CMD_DATE * support for RTC, date/time...
802 CONFIG_CMD_DHCP * DHCP support
803 CONFIG_CMD_DIAG * Diagnostics
804 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
805 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
806 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
807 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
808 CONFIG_CMD_DTT * Digital Therm and Thermostat
809 CONFIG_CMD_ECHO echo arguments
810 CONFIG_CMD_EDITENV edit env variable
811 CONFIG_CMD_EEPROM * EEPROM read/write support
812 CONFIG_CMD_ELF * bootelf, bootvx
813 CONFIG_CMD_EXPORTENV * export the environment
814 CONFIG_CMD_EXT2 * ext2 command support
815 CONFIG_CMD_EXT4 * ext4 command support
816 CONFIG_CMD_SAVEENV saveenv
817 CONFIG_CMD_FDC * Floppy Disk Support
818 CONFIG_CMD_FAT * FAT command support
819 CONFIG_CMD_FDOS * Dos diskette Support
820 CONFIG_CMD_FLASH flinfo, erase, protect
821 CONFIG_CMD_FPGA FPGA device initialization support
822 CONFIG_CMD_GO * the 'go' command (exec code)
823 CONFIG_CMD_GREPENV * search environment
824 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
825 CONFIG_CMD_I2C * I2C serial bus support
826 CONFIG_CMD_IDE * IDE harddisk support
827 CONFIG_CMD_IMI iminfo
828 CONFIG_CMD_IMLS List all found images
829 CONFIG_CMD_IMMAP * IMMR dump support
830 CONFIG_CMD_IMPORTENV * import an environment
831 CONFIG_CMD_INI * import data from an ini file into the env
832 CONFIG_CMD_IRQ * irqinfo
833 CONFIG_CMD_ITEST Integer/string test of 2 values
834 CONFIG_CMD_JFFS2 * JFFS2 Support
835 CONFIG_CMD_KGDB * kgdb
836 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
837 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
838 (169.254.*.*)
839 CONFIG_CMD_LOADB loadb
840 CONFIG_CMD_LOADS loads
841 CONFIG_CMD_MD5SUM print md5 message digest
842 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
843 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
844 loop, loopw, mtest
845 CONFIG_CMD_MISC Misc functions like sleep etc
846 CONFIG_CMD_MMC * MMC memory mapped support
847 CONFIG_CMD_MII * MII utility commands
848 CONFIG_CMD_MTDPARTS * MTD partition support
849 CONFIG_CMD_NAND * NAND support
850 CONFIG_CMD_NET bootp, tftpboot, rarpboot
851 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
852 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
853 CONFIG_CMD_PCI * pciinfo
854 CONFIG_CMD_PCMCIA * PCMCIA support
855 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
856 host
857 CONFIG_CMD_PORTIO * Port I/O
858 CONFIG_CMD_REGINFO * Register dump
859 CONFIG_CMD_RUN run command in env variable
860 CONFIG_CMD_SAVES * save S record dump
861 CONFIG_CMD_SCSI * SCSI Support
862 CONFIG_CMD_SDRAM * print SDRAM configuration information
863 (requires CONFIG_CMD_I2C)
864 CONFIG_CMD_SETGETDCR Support for DCR Register access
865 (4xx only)
866 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
867 CONFIG_CMD_SHA1SUM print sha1 memory digest
868 (requires CONFIG_CMD_MEMORY)
869 CONFIG_CMD_SOURCE "source" command Support
870 CONFIG_CMD_SPI * SPI serial bus support
871 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
872 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
873 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
874 CONFIG_CMD_TIMER * access to the system tick timer
875 CONFIG_CMD_USB * USB support
876 CONFIG_CMD_CDP * Cisco Discover Protocol support
877 CONFIG_CMD_MFSL * Microblaze FSL support
880 EXAMPLE: If you want all functions except of network
881 support you can write:
883 #include "config_cmd_all.h"
884 #undef CONFIG_CMD_NET
886 Other Commands:
887 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
889 Note: Don't enable the "icache" and "dcache" commands
890 (configuration option CONFIG_CMD_CACHE) unless you know
891 what you (and your U-Boot users) are doing. Data
892 cache cannot be enabled on systems like the 8xx or
893 8260 (where accesses to the IMMR region must be
894 uncached), and it cannot be disabled on all other
895 systems where we (mis-) use the data cache to hold an
896 initial stack and some data.
899 XXX - this list needs to get updated!
901 - Device tree:
902 CONFIG_OF_CONTROL
903 If this variable is defined, U-Boot will use a device tree
904 to configure its devices, instead of relying on statically
905 compiled #defines in the board file. This option is
906 experimental and only available on a few boards. The device
907 tree is available in the global data as gd->fdt_blob.
909 U-Boot needs to get its device tree from somewhere. This can
910 be done using one of the two options below:
912 CONFIG_OF_EMBED
913 If this variable is defined, U-Boot will embed a device tree
914 binary in its image. This device tree file should be in the
915 board directory and called <soc>-<board>.dts. The binary file
916 is then picked up in board_init_f() and made available through
917 the global data structure as gd->blob.
919 CONFIG_OF_SEPARATE
920 If this variable is defined, U-Boot will build a device tree
921 binary. It will be called u-boot.dtb. Architecture-specific
922 code will locate it at run-time. Generally this works by:
924 cat u-boot.bin u-boot.dtb >image.bin
926 and in fact, U-Boot does this for you, creating a file called
927 u-boot-dtb.bin which is useful in the common case. You can
928 still use the individual files if you need something more
929 exotic.
931 - Watchdog:
932 CONFIG_WATCHDOG
933 If this variable is defined, it enables watchdog
934 support for the SoC. There must be support in the SoC
935 specific code for a watchdog. For the 8xx and 8260
936 CPUs, the SIU Watchdog feature is enabled in the SYPCR
937 register. When supported for a specific SoC is
938 available, then no further board specific code should
939 be needed to use it.
941 CONFIG_HW_WATCHDOG
942 When using a watchdog circuitry external to the used
943 SoC, then define this variable and provide board
944 specific code for the "hw_watchdog_reset" function.
946 - U-Boot Version:
947 CONFIG_VERSION_VARIABLE
948 If this variable is defined, an environment variable
949 named "ver" is created by U-Boot showing the U-Boot
950 version as printed by the "version" command.
951 Any change to this variable will be reverted at the
952 next reset.
954 - Real-Time Clock:
956 When CONFIG_CMD_DATE is selected, the type of the RTC
957 has to be selected, too. Define exactly one of the
958 following options:
960 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
961 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
962 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
963 CONFIG_RTC_MC146818 - use MC146818 RTC
964 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
965 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
966 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
967 CONFIG_RTC_DS164x - use Dallas DS164x RTC
968 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
969 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
970 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
971 CONFIG_SYS_RV3029_TCR - enable trickle charger on
972 RV3029 RTC.
974 Note that if the RTC uses I2C, then the I2C interface
975 must also be configured. See I2C Support, below.
977 - GPIO Support:
978 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
979 CONFIG_PCA953X_INFO - enable pca953x info command
981 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
982 chip-ngpio pairs that tell the PCA953X driver the number of
983 pins supported by a particular chip.
985 Note that if the GPIO device uses I2C, then the I2C interface
986 must also be configured. See I2C Support, below.
988 - Timestamp Support:
990 When CONFIG_TIMESTAMP is selected, the timestamp
991 (date and time) of an image is printed by image
992 commands like bootm or iminfo. This option is
993 automatically enabled when you select CONFIG_CMD_DATE .
995 - Partition Labels (disklabels) Supported:
996 Zero or more of the following:
997 CONFIG_MAC_PARTITION Apple's MacOS partition table.
998 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
999 Intel architecture, USB sticks, etc.
1000 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1001 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1002 bootloader. Note 2TB partition limit; see
1003 disk/part_efi.c
1004 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1006 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1007 CONFIG_CMD_SCSI) you must configure support for at
1008 least one non-MTD partition type as well.
1010 - IDE Reset method:
1011 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1012 board configurations files but used nowhere!
1014 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1015 be performed by calling the function
1016 ide_set_reset(int reset)
1017 which has to be defined in a board specific file
1019 - ATAPI Support:
1020 CONFIG_ATAPI
1022 Set this to enable ATAPI support.
1024 - LBA48 Support
1025 CONFIG_LBA48
1027 Set this to enable support for disks larger than 137GB
1028 Also look at CONFIG_SYS_64BIT_LBA.
1029 Whithout these , LBA48 support uses 32bit variables and will 'only'
1030 support disks up to 2.1TB.
1032 CONFIG_SYS_64BIT_LBA:
1033 When enabled, makes the IDE subsystem use 64bit sector addresses.
1034 Default is 32bit.
1036 - SCSI Support:
1037 At the moment only there is only support for the
1038 SYM53C8XX SCSI controller; define
1039 CONFIG_SCSI_SYM53C8XX to enable it.
1041 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1042 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1043 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1044 maximum numbers of LUNs, SCSI ID's and target
1045 devices.
1046 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1048 The environment variable 'scsidevs' is set to the number of
1049 SCSI devices found during the last scan.
1051 - NETWORK Support (PCI):
1052 CONFIG_E1000
1053 Support for Intel 8254x/8257x gigabit chips.
1055 CONFIG_E1000_SPI
1056 Utility code for direct access to the SPI bus on Intel 8257x.
1057 This does not do anything useful unless you set at least one
1058 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1060 CONFIG_E1000_SPI_GENERIC
1061 Allow generic access to the SPI bus on the Intel 8257x, for
1062 example with the "sspi" command.
1064 CONFIG_CMD_E1000
1065 Management command for E1000 devices. When used on devices
1066 with SPI support you can reprogram the EEPROM from U-Boot.
1068 CONFIG_E1000_FALLBACK_MAC
1069 default MAC for empty EEPROM after production.
1071 CONFIG_EEPRO100
1072 Support for Intel 82557/82559/82559ER chips.
1073 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1074 write routine for first time initialisation.
1076 CONFIG_TULIP
1077 Support for Digital 2114x chips.
1078 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1079 modem chip initialisation (KS8761/QS6611).
1081 CONFIG_NATSEMI
1082 Support for National dp83815 chips.
1084 CONFIG_NS8382X
1085 Support for National dp8382[01] gigabit chips.
1087 - NETWORK Support (other):
1089 CONFIG_DRIVER_AT91EMAC
1090 Support for AT91RM9200 EMAC.
1092 CONFIG_RMII
1093 Define this to use reduced MII inteface
1095 CONFIG_DRIVER_AT91EMAC_QUIET
1096 If this defined, the driver is quiet.
1097 The driver doen't show link status messages.
1099 CONFIG_CALXEDA_XGMAC
1100 Support for the Calxeda XGMAC device
1102 CONFIG_LAN91C96
1103 Support for SMSC's LAN91C96 chips.
1105 CONFIG_LAN91C96_BASE
1106 Define this to hold the physical address
1107 of the LAN91C96's I/O space
1109 CONFIG_LAN91C96_USE_32_BIT
1110 Define this to enable 32 bit addressing
1112 CONFIG_SMC91111
1113 Support for SMSC's LAN91C111 chip
1115 CONFIG_SMC91111_BASE
1116 Define this to hold the physical address
1117 of the device (I/O space)
1119 CONFIG_SMC_USE_32_BIT
1120 Define this if data bus is 32 bits
1122 CONFIG_SMC_USE_IOFUNCS
1123 Define this to use i/o functions instead of macros
1124 (some hardware wont work with macros)
1126 CONFIG_DRIVER_TI_EMAC
1127 Support for davinci emac
1129 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1130 Define this if you have more then 3 PHYs.
1132 CONFIG_FTGMAC100
1133 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1135 CONFIG_FTGMAC100_EGIGA
1136 Define this to use GE link update with gigabit PHY.
1137 Define this if FTGMAC100 is connected to gigabit PHY.
1138 If your system has 10/100 PHY only, it might not occur
1139 wrong behavior. Because PHY usually return timeout or
1140 useless data when polling gigabit status and gigabit
1141 control registers. This behavior won't affect the
1142 correctnessof 10/100 link speed update.
1144 CONFIG_SMC911X
1145 Support for SMSC's LAN911x and LAN921x chips
1147 CONFIG_SMC911X_BASE
1148 Define this to hold the physical address
1149 of the device (I/O space)
1151 CONFIG_SMC911X_32_BIT
1152 Define this if data bus is 32 bits
1154 CONFIG_SMC911X_16_BIT
1155 Define this if data bus is 16 bits. If your processor
1156 automatically converts one 32 bit word to two 16 bit
1157 words you may also try CONFIG_SMC911X_32_BIT.
1159 CONFIG_SH_ETHER
1160 Support for Renesas on-chip Ethernet controller
1162 CONFIG_SH_ETHER_USE_PORT
1163 Define the number of ports to be used
1165 CONFIG_SH_ETHER_PHY_ADDR
1166 Define the ETH PHY's address
1168 CONFIG_SH_ETHER_CACHE_WRITEBACK
1169 If this option is set, the driver enables cache flush.
1171 - TPM Support:
1172 CONFIG_GENERIC_LPC_TPM
1173 Support for generic parallel port TPM devices. Only one device
1174 per system is supported at this time.
1176 CONFIG_TPM_TIS_BASE_ADDRESS
1177 Base address where the generic TPM device is mapped
1178 to. Contemporary x86 systems usually map it at
1179 0xfed40000.
1181 - USB Support:
1182 At the moment only the UHCI host controller is
1183 supported (PIP405, MIP405, MPC5200); define
1184 CONFIG_USB_UHCI to enable it.
1185 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1186 and define CONFIG_USB_STORAGE to enable the USB
1187 storage devices.
1188 Note:
1189 Supported are USB Keyboards and USB Floppy drives
1190 (TEAC FD-05PUB).
1191 MPC5200 USB requires additional defines:
1192 CONFIG_USB_CLOCK
1193 for 528 MHz Clock: 0x0001bbbb
1194 CONFIG_PSC3_USB
1195 for USB on PSC3
1196 CONFIG_USB_CONFIG
1197 for differential drivers: 0x00001000
1198 for single ended drivers: 0x00005000
1199 for differential drivers on PSC3: 0x00000100
1200 for single ended drivers on PSC3: 0x00004100
1201 CONFIG_SYS_USB_EVENT_POLL
1202 May be defined to allow interrupt polling
1203 instead of using asynchronous interrupts
1205 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1206 txfilltuning field in the EHCI controller on reset.
1208 - USB Device:
1209 Define the below if you wish to use the USB console.
1210 Once firmware is rebuilt from a serial console issue the
1211 command "setenv stdin usbtty; setenv stdout usbtty" and
1212 attach your USB cable. The Unix command "dmesg" should print
1213 it has found a new device. The environment variable usbtty
1214 can be set to gserial or cdc_acm to enable your device to
1215 appear to a USB host as a Linux gserial device or a
1216 Common Device Class Abstract Control Model serial device.
1217 If you select usbtty = gserial you should be able to enumerate
1218 a Linux host by
1219 # modprobe usbserial vendor=0xVendorID product=0xProductID
1220 else if using cdc_acm, simply setting the environment
1221 variable usbtty to be cdc_acm should suffice. The following
1222 might be defined in YourBoardName.h
1224 CONFIG_USB_DEVICE
1225 Define this to build a UDC device
1227 CONFIG_USB_TTY
1228 Define this to have a tty type of device available to
1229 talk to the UDC device
1231 CONFIG_USBD_HS
1232 Define this to enable the high speed support for usb
1233 device and usbtty. If this feature is enabled, a routine
1234 int is_usbd_high_speed(void)
1235 also needs to be defined by the driver to dynamically poll
1236 whether the enumeration has succeded at high speed or full
1237 speed.
1239 CONFIG_SYS_CONSOLE_IS_IN_ENV
1240 Define this if you want stdin, stdout &/or stderr to
1241 be set to usbtty.
1243 mpc8xx:
1244 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1245 Derive USB clock from external clock "blah"
1246 - CONFIG_SYS_USB_EXTC_CLK 0x02
1248 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1249 Derive USB clock from brgclk
1250 - CONFIG_SYS_USB_BRG_CLK 0x04
1252 If you have a USB-IF assigned VendorID then you may wish to
1253 define your own vendor specific values either in BoardName.h
1254 or directly in usbd_vendor_info.h. If you don't define
1255 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1256 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1257 should pretend to be a Linux device to it's target host.
1259 CONFIG_USBD_MANUFACTURER
1260 Define this string as the name of your company for
1261 - CONFIG_USBD_MANUFACTURER "my company"
1263 CONFIG_USBD_PRODUCT_NAME
1264 Define this string as the name of your product
1265 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1267 CONFIG_USBD_VENDORID
1268 Define this as your assigned Vendor ID from the USB
1269 Implementors Forum. This *must* be a genuine Vendor ID
1270 to avoid polluting the USB namespace.
1271 - CONFIG_USBD_VENDORID 0xFFFF
1273 CONFIG_USBD_PRODUCTID
1274 Define this as the unique Product ID
1275 for your device
1276 - CONFIG_USBD_PRODUCTID 0xFFFF
1278 - ULPI Layer Support:
1279 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1280 the generic ULPI layer. The generic layer accesses the ULPI PHY
1281 via the platform viewport, so you need both the genric layer and
1282 the viewport enabled. Currently only Chipidea/ARC based
1283 viewport is supported.
1284 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1285 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1286 If your ULPI phy needs a different reference clock than the
1287 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1288 the appropriate value in Hz.
1290 - MMC Support:
1291 The MMC controller on the Intel PXA is supported. To
1292 enable this define CONFIG_MMC. The MMC can be
1293 accessed from the boot prompt by mapping the device
1294 to physical memory similar to flash. Command line is
1295 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1296 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1298 CONFIG_SH_MMCIF
1299 Support for Renesas on-chip MMCIF controller
1301 CONFIG_SH_MMCIF_ADDR
1302 Define the base address of MMCIF registers
1304 CONFIG_SH_MMCIF_CLK
1305 Define the clock frequency for MMCIF
1307 - Journaling Flash filesystem support:
1308 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1309 CONFIG_JFFS2_NAND_DEV
1310 Define these for a default partition on a NAND device
1312 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1313 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1314 Define these for a default partition on a NOR device
1316 CONFIG_SYS_JFFS_CUSTOM_PART
1317 Define this to create an own partition. You have to provide a
1318 function struct part_info* jffs2_part_info(int part_num)
1320 If you define only one JFFS2 partition you may also want to
1321 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1322 to disable the command chpart. This is the default when you
1323 have not defined a custom partition
1325 - FAT(File Allocation Table) filesystem write function support:
1326 CONFIG_FAT_WRITE
1328 Define this to enable support for saving memory data as a
1329 file in FAT formatted partition.
1331 This will also enable the command "fatwrite" enabling the
1332 user to write files to FAT.
1334 CBFS (Coreboot Filesystem) support
1335 CONFIG_CMD_CBFS
1337 Define this to enable support for reading from a Coreboot
1338 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1339 and cbfsload.
1341 - Keyboard Support:
1342 CONFIG_ISA_KEYBOARD
1344 Define this to enable standard (PC-Style) keyboard
1345 support
1347 CONFIG_I8042_KBD
1348 Standard PC keyboard driver with US (is default) and
1349 GERMAN key layout (switch via environment 'keymap=de') support.
1350 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1351 for cfb_console. Supports cursor blinking.
1353 - Video support:
1354 CONFIG_VIDEO
1356 Define this to enable video support (for output to
1357 video).
1359 CONFIG_VIDEO_CT69000
1361 Enable Chips & Technologies 69000 Video chip
1363 CONFIG_VIDEO_SMI_LYNXEM
1364 Enable Silicon Motion SMI 712/710/810 Video chip. The
1365 video output is selected via environment 'videoout'
1366 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1367 assumed.
1369 For the CT69000 and SMI_LYNXEM drivers, videomode is
1370 selected via environment 'videomode'. Two different ways
1371 are possible:
1372 - "videomode=num" 'num' is a standard LiLo mode numbers.
1373 Following standard modes are supported (* is default):
1375 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1376 -------------+---------------------------------------------
1377 8 bits | 0x301* 0x303 0x305 0x161 0x307
1378 15 bits | 0x310 0x313 0x316 0x162 0x319
1379 16 bits | 0x311 0x314 0x317 0x163 0x31A
1380 24 bits | 0x312 0x315 0x318 ? 0x31B
1381 -------------+---------------------------------------------
1382 (i.e. setenv videomode 317; saveenv; reset;)
1384 - "videomode=bootargs" all the video parameters are parsed
1385 from the bootargs. (See drivers/video/videomodes.c)
1388 CONFIG_VIDEO_SED13806
1389 Enable Epson SED13806 driver. This driver supports 8bpp
1390 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1391 or CONFIG_VIDEO_SED13806_16BPP
1393 CONFIG_FSL_DIU_FB
1394 Enable the Freescale DIU video driver. Reference boards for
1395 SOCs that have a DIU should define this macro to enable DIU
1396 support, and should also define these other macros:
1398 CONFIG_SYS_DIU_ADDR
1399 CONFIG_VIDEO
1400 CONFIG_CMD_BMP
1401 CONFIG_CFB_CONSOLE
1402 CONFIG_VIDEO_SW_CURSOR
1403 CONFIG_VGA_AS_SINGLE_DEVICE
1404 CONFIG_VIDEO_LOGO
1405 CONFIG_VIDEO_BMP_LOGO
1407 The DIU driver will look for the 'video-mode' environment
1408 variable, and if defined, enable the DIU as a console during
1409 boot. See the documentation file README.video for a
1410 description of this variable.
1412 - Keyboard Support:
1413 CONFIG_KEYBOARD
1415 Define this to enable a custom keyboard support.
1416 This simply calls drv_keyboard_init() which must be
1417 defined in your board-specific files.
1418 The only board using this so far is RBC823.
1420 - LCD Support: CONFIG_LCD
1422 Define this to enable LCD support (for output to LCD
1423 display); also select one of the supported displays
1424 by defining one of these:
1426 CONFIG_ATMEL_LCD:
1428 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1430 CONFIG_NEC_NL6448AC33:
1432 NEC NL6448AC33-18. Active, color, single scan.
1434 CONFIG_NEC_NL6448BC20
1436 NEC NL6448BC20-08. 6.5", 640x480.
1437 Active, color, single scan.
1439 CONFIG_NEC_NL6448BC33_54
1441 NEC NL6448BC33-54. 10.4", 640x480.
1442 Active, color, single scan.
1444 CONFIG_SHARP_16x9
1446 Sharp 320x240. Active, color, single scan.
1447 It isn't 16x9, and I am not sure what it is.
1449 CONFIG_SHARP_LQ64D341
1451 Sharp LQ64D341 display, 640x480.
1452 Active, color, single scan.
1454 CONFIG_HLD1045
1456 HLD1045 display, 640x480.
1457 Active, color, single scan.
1459 CONFIG_OPTREX_BW
1461 Optrex CBL50840-2 NF-FW 99 22 M5
1462 or
1463 Hitachi LMG6912RPFC-00T
1464 or
1465 Hitachi SP14Q002
1467 320x240. Black & white.
1469 Normally display is black on white background; define
1470 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1472 CONFIG_LCD_BMP_RLE8
1474 Support drawing of RLE8-compressed bitmaps on the LCD.
1477 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1479 If this option is set, the environment is checked for
1480 a variable "splashimage". If found, the usual display
1481 of logo, copyright and system information on the LCD
1482 is suppressed and the BMP image at the address
1483 specified in "splashimage" is loaded instead. The
1484 console is redirected to the "nulldev", too. This
1485 allows for a "silent" boot where a splash screen is
1486 loaded very quickly after power-on.
1488 CONFIG_SPLASH_SCREEN_ALIGN
1490 If this option is set the splash image can be freely positioned
1491 on the screen. Environment variable "splashpos" specifies the
1492 position as "x,y". If a positive number is given it is used as
1493 number of pixel from left/top. If a negative number is given it
1494 is used as number of pixel from right/bottom. You can also
1495 specify 'm' for centering the image.
1497 Example:
1498 setenv splashpos m,m
1499 => image at center of screen
1501 setenv splashpos 30,20
1502 => image at x = 30 and y = 20
1504 setenv splashpos -10,m
1505 => vertically centered image
1506 at x = dspWidth - bmpWidth - 9
1508 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1510 If this option is set, additionally to standard BMP
1511 images, gzipped BMP images can be displayed via the
1512 splashscreen support or the bmp command.
1514 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1516 If this option is set, 8-bit RLE compressed BMP images
1517 can be displayed via the splashscreen support or the
1518 bmp command.
1520 - Do compresssing for memory range:
1521 CONFIG_CMD_ZIP
1523 If this option is set, it would use zlib deflate method
1524 to compress the specified memory at its best effort.
1526 - Compression support:
1527 CONFIG_BZIP2
1529 If this option is set, support for bzip2 compressed
1530 images is included. If not, only uncompressed and gzip
1531 compressed images are supported.
1533 NOTE: the bzip2 algorithm requires a lot of RAM, so
1534 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1535 be at least 4MB.
1537 CONFIG_LZMA
1539 If this option is set, support for lzma compressed
1540 images is included.
1542 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1543 requires an amount of dynamic memory that is given by the
1544 formula:
1546 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1548 Where lc and lp stand for, respectively, Literal context bits
1549 and Literal pos bits.
1551 This value is upper-bounded by 14MB in the worst case. Anyway,
1552 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1553 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1554 a very small buffer.
1556 Use the lzmainfo tool to determinate the lc and lp values and
1557 then calculate the amount of needed dynamic memory (ensuring
1558 the appropriate CONFIG_SYS_MALLOC_LEN value).
1560 - MII/PHY support:
1561 CONFIG_PHY_ADDR
1563 The address of PHY on MII bus.
1565 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1567 The clock frequency of the MII bus
1569 CONFIG_PHY_GIGE
1571 If this option is set, support for speed/duplex
1572 detection of gigabit PHY is included.
1574 CONFIG_PHY_RESET_DELAY
1576 Some PHY like Intel LXT971A need extra delay after
1577 reset before any MII register access is possible.
1578 For such PHY, set this option to the usec delay
1579 required. (minimum 300usec for LXT971A)
1581 CONFIG_PHY_CMD_DELAY (ppc4xx)
1583 Some PHY like Intel LXT971A need extra delay after
1584 command issued before MII status register can be read
1586 - Ethernet address:
1587 CONFIG_ETHADDR
1588 CONFIG_ETH1ADDR
1589 CONFIG_ETH2ADDR
1590 CONFIG_ETH3ADDR
1591 CONFIG_ETH4ADDR
1592 CONFIG_ETH5ADDR
1594 Define a default value for Ethernet address to use
1595 for the respective Ethernet interface, in case this
1596 is not determined automatically.
1598 - IP address:
1599 CONFIG_IPADDR
1601 Define a default value for the IP address to use for
1602 the default Ethernet interface, in case this is not
1603 determined through e.g. bootp.
1604 (Environment variable "ipaddr")
1606 - Server IP address:
1607 CONFIG_SERVERIP
1609 Defines a default value for the IP address of a TFTP
1610 server to contact when using the "tftboot" command.
1611 (Environment variable "serverip")
1613 CONFIG_KEEP_SERVERADDR
1615 Keeps the server's MAC address, in the env 'serveraddr'
1616 for passing to bootargs (like Linux's netconsole option)
1618 - Gateway IP address:
1619 CONFIG_GATEWAYIP
1621 Defines a default value for the IP address of the
1622 default router where packets to other networks are
1623 sent to.
1624 (Environment variable "gatewayip")
1626 - Subnet mask:
1627 CONFIG_NETMASK
1629 Defines a default value for the subnet mask (or
1630 routing prefix) which is used to determine if an IP
1631 address belongs to the local subnet or needs to be
1632 forwarded through a router.
1633 (Environment variable "netmask")
1635 - Multicast TFTP Mode:
1636 CONFIG_MCAST_TFTP
1638 Defines whether you want to support multicast TFTP as per
1639 rfc-2090; for example to work with atftp. Lets lots of targets
1640 tftp down the same boot image concurrently. Note: the Ethernet
1641 driver in use must provide a function: mcast() to join/leave a
1642 multicast group.
1644 - BOOTP Recovery Mode:
1645 CONFIG_BOOTP_RANDOM_DELAY
1647 If you have many targets in a network that try to
1648 boot using BOOTP, you may want to avoid that all
1649 systems send out BOOTP requests at precisely the same
1650 moment (which would happen for instance at recovery
1651 from a power failure, when all systems will try to
1652 boot, thus flooding the BOOTP server. Defining
1653 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1654 inserted before sending out BOOTP requests. The
1655 following delays are inserted then:
1657 1st BOOTP request: delay 0 ... 1 sec
1658 2nd BOOTP request: delay 0 ... 2 sec
1659 3rd BOOTP request: delay 0 ... 4 sec
1660 4th and following
1661 BOOTP requests: delay 0 ... 8 sec
1663 - DHCP Advanced Options:
1664 You can fine tune the DHCP functionality by defining
1665 CONFIG_BOOTP_* symbols:
1667 CONFIG_BOOTP_SUBNETMASK
1668 CONFIG_BOOTP_GATEWAY
1669 CONFIG_BOOTP_HOSTNAME
1670 CONFIG_BOOTP_NISDOMAIN
1671 CONFIG_BOOTP_BOOTPATH
1672 CONFIG_BOOTP_BOOTFILESIZE
1673 CONFIG_BOOTP_DNS
1674 CONFIG_BOOTP_DNS2
1675 CONFIG_BOOTP_SEND_HOSTNAME
1676 CONFIG_BOOTP_NTPSERVER
1677 CONFIG_BOOTP_TIMEOFFSET
1678 CONFIG_BOOTP_VENDOREX
1679 CONFIG_BOOTP_MAY_FAIL
1681 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1682 environment variable, not the BOOTP server.
1684 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1685 after the configured retry count, the call will fail
1686 instead of starting over. This can be used to fail over
1687 to Link-local IP address configuration if the DHCP server
1688 is not available.
1690 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1691 serverip from a DHCP server, it is possible that more
1692 than one DNS serverip is offered to the client.
1693 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1694 serverip will be stored in the additional environment
1695 variable "dnsip2". The first DNS serverip is always
1696 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1697 is defined.
1699 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1700 to do a dynamic update of a DNS server. To do this, they
1701 need the hostname of the DHCP requester.
1702 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1703 of the "hostname" environment variable is passed as
1704 option 12 to the DHCP server.
1706 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1708 A 32bit value in microseconds for a delay between
1709 receiving a "DHCP Offer" and sending the "DHCP Request".
1710 This fixes a problem with certain DHCP servers that don't
1711 respond 100% of the time to a "DHCP request". E.g. On an
1712 AT91RM9200 processor running at 180MHz, this delay needed
1713 to be *at least* 15,000 usec before a Windows Server 2003
1714 DHCP server would reply 100% of the time. I recommend at
1715 least 50,000 usec to be safe. The alternative is to hope
1716 that one of the retries will be successful but note that
1717 the DHCP timeout and retry process takes a longer than
1718 this delay.
1720 - Link-local IP address negotiation:
1721 Negotiate with other link-local clients on the local network
1722 for an address that doesn't require explicit configuration.
1723 This is especially useful if a DHCP server cannot be guaranteed
1724 to exist in all environments that the device must operate.
1726 See doc/README.link-local for more information.
1728 - CDP Options:
1729 CONFIG_CDP_DEVICE_ID
1731 The device id used in CDP trigger frames.
1733 CONFIG_CDP_DEVICE_ID_PREFIX
1735 A two character string which is prefixed to the MAC address
1736 of the device.
1738 CONFIG_CDP_PORT_ID
1740 A printf format string which contains the ascii name of
1741 the port. Normally is set to "eth%d" which sets
1742 eth0 for the first Ethernet, eth1 for the second etc.
1744 CONFIG_CDP_CAPABILITIES
1746 A 32bit integer which indicates the device capabilities;
1747 0x00000010 for a normal host which does not forwards.
1749 CONFIG_CDP_VERSION
1751 An ascii string containing the version of the software.
1753 CONFIG_CDP_PLATFORM
1755 An ascii string containing the name of the platform.
1757 CONFIG_CDP_TRIGGER
1759 A 32bit integer sent on the trigger.
1761 CONFIG_CDP_POWER_CONSUMPTION
1763 A 16bit integer containing the power consumption of the
1764 device in .1 of milliwatts.
1766 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1768 A byte containing the id of the VLAN.
1770 - Status LED: CONFIG_STATUS_LED
1772 Several configurations allow to display the current
1773 status using a LED. For instance, the LED will blink
1774 fast while running U-Boot code, stop blinking as
1775 soon as a reply to a BOOTP request was received, and
1776 start blinking slow once the Linux kernel is running
1777 (supported by a status LED driver in the Linux
1778 kernel). Defining CONFIG_STATUS_LED enables this
1779 feature in U-Boot.
1781 - CAN Support: CONFIG_CAN_DRIVER
1783 Defining CONFIG_CAN_DRIVER enables CAN driver support
1784 on those systems that support this (optional)
1785 feature, like the TQM8xxL modules.
1787 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1789 These enable I2C serial bus commands. Defining either of
1790 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1791 include the appropriate I2C driver for the selected CPU.
1793 This will allow you to use i2c commands at the u-boot
1794 command line (as long as you set CONFIG_CMD_I2C in
1795 CONFIG_COMMANDS) and communicate with i2c based realtime
1796 clock chips. See common/cmd_i2c.c for a description of the
1797 command line interface.
1799 CONFIG_HARD_I2C selects a hardware I2C controller.
1801 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1802 bit-banging) driver instead of CPM or similar hardware
1803 support for I2C.
1805 There are several other quantities that must also be
1806 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1808 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1809 to be the frequency (in Hz) at which you wish your i2c bus
1810 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1811 the CPU's i2c node address).
1813 Now, the u-boot i2c code for the mpc8xx
1814 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1815 and so its address should therefore be cleared to 0 (See,
1816 eg, MPC823e User's Manual p.16-473). So, set
1817 CONFIG_SYS_I2C_SLAVE to 0.
1819 CONFIG_SYS_I2C_INIT_MPC5XXX
1821 When a board is reset during an i2c bus transfer
1822 chips might think that the current transfer is still
1823 in progress. Reset the slave devices by sending start
1824 commands until the slave device responds.
1826 That's all that's required for CONFIG_HARD_I2C.
1828 If you use the software i2c interface (CONFIG_SOFT_I2C)
1829 then the following macros need to be defined (examples are
1830 from include/configs/lwmon.h):
1832 I2C_INIT
1834 (Optional). Any commands necessary to enable the I2C
1835 controller or configure ports.
1837 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1839 I2C_PORT
1841 (Only for MPC8260 CPU). The I/O port to use (the code
1842 assumes both bits are on the same port). Valid values
1843 are 0..3 for ports A..D.
1845 I2C_ACTIVE
1847 The code necessary to make the I2C data line active
1848 (driven). If the data line is open collector, this
1849 define can be null.
1851 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1853 I2C_TRISTATE
1855 The code necessary to make the I2C data line tri-stated
1856 (inactive). If the data line is open collector, this
1857 define can be null.
1859 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1861 I2C_READ
1863 Code that returns TRUE if the I2C data line is high,
1864 FALSE if it is low.
1866 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1868 I2C_SDA(bit)
1870 If <bit> is TRUE, sets the I2C data line high. If it
1871 is FALSE, it clears it (low).
1873 eg: #define I2C_SDA(bit) \
1874 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1875 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1877 I2C_SCL(bit)
1879 If <bit> is TRUE, sets the I2C clock line high. If it
1880 is FALSE, it clears it (low).
1882 eg: #define I2C_SCL(bit) \
1883 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1884 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1886 I2C_DELAY
1888 This delay is invoked four times per clock cycle so this
1889 controls the rate of data transfer. The data rate thus
1890 is 1 / (I2C_DELAY * 4). Often defined to be something
1891 like:
1893 #define I2C_DELAY udelay(2)
1895 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1897 If your arch supports the generic GPIO framework (asm/gpio.h),
1898 then you may alternatively define the two GPIOs that are to be
1899 used as SCL / SDA. Any of the previous I2C_xxx macros will
1900 have GPIO-based defaults assigned to them as appropriate.
1902 You should define these to the GPIO value as given directly to
1903 the generic GPIO functions.
1905 CONFIG_SYS_I2C_INIT_BOARD
1907 When a board is reset during an i2c bus transfer
1908 chips might think that the current transfer is still
1909 in progress. On some boards it is possible to access
1910 the i2c SCLK line directly, either by using the
1911 processor pin as a GPIO or by having a second pin
1912 connected to the bus. If this option is defined a
1913 custom i2c_init_board() routine in boards/xxx/board.c
1914 is run early in the boot sequence.
1916 CONFIG_SYS_I2C_BOARD_LATE_INIT
1918 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1919 defined a custom i2c_board_late_init() routine in
1920 boards/xxx/board.c is run AFTER the operations in i2c_init()
1921 is completed. This callpoint can be used to unreset i2c bus
1922 using CPU i2c controller register accesses for CPUs whose i2c
1923 controller provide such a method. It is called at the end of
1924 i2c_init() to allow i2c_init operations to setup the i2c bus
1925 controller on the CPU (e.g. setting bus speed & slave address).
1927 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1929 This option enables configuration of bi_iic_fast[] flags
1930 in u-boot bd_info structure based on u-boot environment
1931 variable "i2cfast". (see also i2cfast)
1933 CONFIG_I2C_MULTI_BUS
1935 This option allows the use of multiple I2C buses, each of which
1936 must have a controller. At any point in time, only one bus is
1937 active. To switch to a different bus, use the 'i2c dev' command.
1938 Note that bus numbering is zero-based.
1940 CONFIG_SYS_I2C_NOPROBES
1942 This option specifies a list of I2C devices that will be skipped
1943 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1944 is set, specify a list of bus-device pairs. Otherwise, specify
1945 a 1D array of device addresses
1947 e.g.
1948 #undef CONFIG_I2C_MULTI_BUS
1949 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1951 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1953 #define CONFIG_I2C_MULTI_BUS
1954 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1956 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1958 CONFIG_SYS_SPD_BUS_NUM
1960 If defined, then this indicates the I2C bus number for DDR SPD.
1961 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1963 CONFIG_SYS_RTC_BUS_NUM
1965 If defined, then this indicates the I2C bus number for the RTC.
1966 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1968 CONFIG_SYS_DTT_BUS_NUM
1970 If defined, then this indicates the I2C bus number for the DTT.
1971 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1973 CONFIG_SYS_I2C_DTT_ADDR:
1975 If defined, specifies the I2C address of the DTT device.
1976 If not defined, then U-Boot uses predefined value for
1977 specified DTT device.
1979 CONFIG_FSL_I2C
1981 Define this option if you want to use Freescale's I2C driver in
1982 drivers/i2c/fsl_i2c.c.
1984 CONFIG_I2C_MUX
1986 Define this option if you have I2C devices reached over 1 .. n
1987 I2C Muxes like the pca9544a. This option addes a new I2C
1988 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1989 new I2C Bus to the existing I2C Busses. If you select the
1990 new Bus with "i2c dev", u-bbot sends first the commandos for
1991 the muxes to activate this new "bus".
1993 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1994 feature!
1996 Example:
1997 Adding a new I2C Bus reached over 2 pca9544a muxes
1998 The First mux with address 70 and channel 6
1999 The Second mux with address 71 and channel 4
2001 => i2c bus pca9544a:70:6:pca9544a:71:4
2003 Use the "i2c bus" command without parameter, to get a list
2004 of I2C Busses with muxes:
2006 => i2c bus
2007 Busses reached over muxes:
2008 Bus ID: 2
2009 reached over Mux(es):
2010 pca9544a@70 ch: 4
2011 Bus ID: 3
2012 reached over Mux(es):
2013 pca9544a@70 ch: 6
2014 pca9544a@71 ch: 4
2015 =>
2017 If you now switch to the new I2C Bus 3 with "i2c dev 3"
2018 u-boot first sends the command to the mux@70 to enable
2019 channel 6, and then the command to the mux@71 to enable
2020 the channel 4.
2022 After that, you can use the "normal" i2c commands as
2023 usual to communicate with your I2C devices behind
2024 the 2 muxes.
2026 This option is actually implemented for the bitbanging
2027 algorithm in common/soft_i2c.c and for the Hardware I2C
2028 Bus on the MPC8260. But it should be not so difficult
2029 to add this option to other architectures.
2031 CONFIG_SOFT_I2C_READ_REPEATED_START
2033 defining this will force the i2c_read() function in
2034 the soft_i2c driver to perform an I2C repeated start
2035 between writing the address pointer and reading the
2036 data. If this define is omitted the default behaviour
2037 of doing a stop-start sequence will be used. Most I2C
2038 devices can use either method, but some require one or
2039 the other.
2041 - SPI Support: CONFIG_SPI
2043 Enables SPI driver (so far only tested with
2044 SPI EEPROM, also an instance works with Crystal A/D and
2045 D/As on the SACSng board)
2047 CONFIG_SH_SPI
2049 Enables the driver for SPI controller on SuperH. Currently
2050 only SH7757 is supported.
2052 CONFIG_SPI_X
2054 Enables extended (16-bit) SPI EEPROM addressing.
2055 (symmetrical to CONFIG_I2C_X)
2057 CONFIG_SOFT_SPI
2059 Enables a software (bit-bang) SPI driver rather than
2060 using hardware support. This is a general purpose
2061 driver that only requires three general I/O port pins
2062 (two outputs, one input) to function. If this is
2063 defined, the board configuration must define several
2064 SPI configuration items (port pins to use, etc). For
2065 an example, see include/configs/sacsng.h.
2067 CONFIG_HARD_SPI
2069 Enables a hardware SPI driver for general-purpose reads
2070 and writes. As with CONFIG_SOFT_SPI, the board configuration
2071 must define a list of chip-select function pointers.
2072 Currently supported on some MPC8xxx processors. For an
2073 example, see include/configs/mpc8349emds.h.
2075 CONFIG_MXC_SPI
2077 Enables the driver for the SPI controllers on i.MX and MXC
2078 SoCs. Currently i.MX31/35/51 are supported.
2080 - FPGA Support: CONFIG_FPGA
2082 Enables FPGA subsystem.
2084 CONFIG_FPGA_<vendor>
2086 Enables support for specific chip vendors.
2087 (ALTERA, XILINX)
2089 CONFIG_FPGA_<family>
2091 Enables support for FPGA family.
2092 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2094 CONFIG_FPGA_COUNT
2096 Specify the number of FPGA devices to support.
2098 CONFIG_SYS_FPGA_PROG_FEEDBACK
2100 Enable printing of hash marks during FPGA configuration.
2102 CONFIG_SYS_FPGA_CHECK_BUSY
2104 Enable checks on FPGA configuration interface busy
2105 status by the configuration function. This option
2106 will require a board or device specific function to
2107 be written.
2109 CONFIG_FPGA_DELAY
2111 If defined, a function that provides delays in the FPGA
2112 configuration driver.
2114 CONFIG_SYS_FPGA_CHECK_CTRLC
2115 Allow Control-C to interrupt FPGA configuration
2117 CONFIG_SYS_FPGA_CHECK_ERROR
2119 Check for configuration errors during FPGA bitfile
2120 loading. For example, abort during Virtex II
2121 configuration if the INIT_B line goes low (which
2122 indicated a CRC error).
2124 CONFIG_SYS_FPGA_WAIT_INIT
2126 Maximum time to wait for the INIT_B line to deassert
2127 after PROB_B has been deasserted during a Virtex II
2128 FPGA configuration sequence. The default time is 500
2129 ms.
2131 CONFIG_SYS_FPGA_WAIT_BUSY
2133 Maximum time to wait for BUSY to deassert during
2134 Virtex II FPGA configuration. The default is 5 ms.
2136 CONFIG_SYS_FPGA_WAIT_CONFIG
2138 Time to wait after FPGA configuration. The default is
2139 200 ms.
2141 - Configuration Management:
2142 CONFIG_IDENT_STRING
2144 If defined, this string will be added to the U-Boot
2145 version information (U_BOOT_VERSION)
2147 - Vendor Parameter Protection:
2149 U-Boot considers the values of the environment
2150 variables "serial#" (Board Serial Number) and
2151 "ethaddr" (Ethernet Address) to be parameters that
2152 are set once by the board vendor / manufacturer, and
2153 protects these variables from casual modification by
2154 the user. Once set, these variables are read-only,
2155 and write or delete attempts are rejected. You can
2156 change this behaviour:
2158 If CONFIG_ENV_OVERWRITE is #defined in your config
2159 file, the write protection for vendor parameters is
2160 completely disabled. Anybody can change or delete
2161 these parameters.
2163 Alternatively, if you #define _both_ CONFIG_ETHADDR
2164 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2165 Ethernet address is installed in the environment,
2166 which can be changed exactly ONCE by the user. [The
2167 serial# is unaffected by this, i. e. it remains
2168 read-only.]
2170 - Protected RAM:
2171 CONFIG_PRAM
2173 Define this variable to enable the reservation of
2174 "protected RAM", i. e. RAM which is not overwritten
2175 by U-Boot. Define CONFIG_PRAM to hold the number of
2176 kB you want to reserve for pRAM. You can overwrite
2177 this default value by defining an environment
2178 variable "pram" to the number of kB you want to
2179 reserve. Note that the board info structure will
2180 still show the full amount of RAM. If pRAM is
2181 reserved, a new environment variable "mem" will
2182 automatically be defined to hold the amount of
2183 remaining RAM in a form that can be passed as boot
2184 argument to Linux, for instance like that:
2186 setenv bootargs ... mem=\${mem}
2187 saveenv
2189 This way you can tell Linux not to use this memory,
2190 either, which results in a memory region that will
2191 not be affected by reboots.
2193 *WARNING* If your board configuration uses automatic
2194 detection of the RAM size, you must make sure that
2195 this memory test is non-destructive. So far, the
2196 following board configurations are known to be
2197 "pRAM-clean":
2199 IVMS8, IVML24, SPD8xx, TQM8xxL,
2200 HERMES, IP860, RPXlite, LWMON,
2201 FLAGADM, TQM8260
2203 - Error Recovery:
2204 CONFIG_PANIC_HANG
2206 Define this variable to stop the system in case of a
2207 fatal error, so that you have to reset it manually.
2208 This is probably NOT a good idea for an embedded
2209 system where you want the system to reboot
2210 automatically as fast as possible, but it may be
2211 useful during development since you can try to debug
2212 the conditions that lead to the situation.
2214 CONFIG_NET_RETRY_COUNT
2216 This variable defines the number of retries for
2217 network operations like ARP, RARP, TFTP, or BOOTP
2218 before giving up the operation. If not defined, a
2219 default value of 5 is used.
2221 CONFIG_ARP_TIMEOUT
2223 Timeout waiting for an ARP reply in milliseconds.
2225 CONFIG_NFS_TIMEOUT
2227 Timeout in milliseconds used in NFS protocol.
2228 If you encounter "ERROR: Cannot umount" in nfs command,
2229 try longer timeout such as
2230 #define CONFIG_NFS_TIMEOUT 10000UL
2232 - Command Interpreter:
2233 CONFIG_AUTO_COMPLETE
2235 Enable auto completion of commands using TAB.
2237 Note that this feature has NOT been implemented yet
2238 for the "hush" shell.
2241 CONFIG_SYS_HUSH_PARSER
2243 Define this variable to enable the "hush" shell (from
2244 Busybox) as command line interpreter, thus enabling
2245 powerful command line syntax like
2246 if...then...else...fi conditionals or `&&' and '||'
2247 constructs ("shell scripts").
2249 If undefined, you get the old, much simpler behaviour
2250 with a somewhat smaller memory footprint.
2253 CONFIG_SYS_PROMPT_HUSH_PS2
2255 This defines the secondary prompt string, which is
2256 printed when the command interpreter needs more input
2257 to complete a command. Usually "> ".
2259 Note:
2261 In the current implementation, the local variables
2262 space and global environment variables space are
2263 separated. Local variables are those you define by
2264 simply typing `name=value'. To access a local
2265 variable later on, you have write `$name' or
2266 `${name}'; to execute the contents of a variable
2267 directly type `$name' at the command prompt.
2269 Global environment variables are those you use
2270 setenv/printenv to work with. To run a command stored
2271 in such a variable, you need to use the run command,
2272 and you must not use the '$' sign to access them.
2274 To store commands and special characters in a
2275 variable, please use double quotation marks
2276 surrounding the whole text of the variable, instead
2277 of the backslashes before semicolons and special
2278 symbols.
2280 - Commandline Editing and History:
2281 CONFIG_CMDLINE_EDITING
2283 Enable editing and History functions for interactive
2284 commandline input operations
2286 - Default Environment:
2287 CONFIG_EXTRA_ENV_SETTINGS
2289 Define this to contain any number of null terminated
2290 strings (variable = value pairs) that will be part of
2291 the default environment compiled into the boot image.
2293 For example, place something like this in your
2294 board's config file:
2296 #define CONFIG_EXTRA_ENV_SETTINGS \
2297 "myvar1=value1\0" \
2298 "myvar2=value2\0"
2300 Warning: This method is based on knowledge about the
2301 internal format how the environment is stored by the
2302 U-Boot code. This is NOT an official, exported
2303 interface! Although it is unlikely that this format
2304 will change soon, there is no guarantee either.
2305 You better know what you are doing here.
2307 Note: overly (ab)use of the default environment is
2308 discouraged. Make sure to check other ways to preset
2309 the environment like the "source" command or the
2310 boot command first.
2312 CONFIG_ENV_VARS_UBOOT_CONFIG
2314 Define this in order to add variables describing the
2315 U-Boot build configuration to the default environment.
2316 These will be named arch, cpu, board, vendor, and soc.
2318 Enabling this option will cause the following to be defined:
2320 - CONFIG_SYS_ARCH
2321 - CONFIG_SYS_CPU
2322 - CONFIG_SYS_BOARD
2323 - CONFIG_SYS_VENDOR
2324 - CONFIG_SYS_SOC
2326 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2328 Define this in order to add variables describing certain
2329 run-time determined information about the hardware to the
2330 environment. These will be named board_name, board_rev.
2332 - DataFlash Support:
2333 CONFIG_HAS_DATAFLASH
2335 Defining this option enables DataFlash features and
2336 allows to read/write in Dataflash via the standard
2337 commands cp, md...
2339 - Serial Flash support
2340 CONFIG_CMD_SF
2342 Defining this option enables SPI flash commands
2343 'sf probe/read/write/erase/update'.
2345 Usage requires an initial 'probe' to define the serial
2346 flash parameters, followed by read/write/erase/update
2347 commands.
2349 The following defaults may be provided by the platform
2350 to handle the common case when only a single serial
2351 flash is present on the system.
2353 CONFIG_SF_DEFAULT_BUS Bus identifier
2354 CONFIG_SF_DEFAULT_CS Chip-select
2355 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2356 CONFIG_SF_DEFAULT_SPEED in Hz
2358 - SystemACE Support:
2359 CONFIG_SYSTEMACE
2361 Adding this option adds support for Xilinx SystemACE
2362 chips attached via some sort of local bus. The address
2363 of the chip must also be defined in the
2364 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2366 #define CONFIG_SYSTEMACE
2367 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2369 When SystemACE support is added, the "ace" device type
2370 becomes available to the fat commands, i.e. fatls.
2372 - TFTP Fixed UDP Port:
2373 CONFIG_TFTP_PORT
2375 If this is defined, the environment variable tftpsrcp
2376 is used to supply the TFTP UDP source port value.
2377 If tftpsrcp isn't defined, the normal pseudo-random port
2378 number generator is used.
2380 Also, the environment variable tftpdstp is used to supply
2381 the TFTP UDP destination port value. If tftpdstp isn't
2382 defined, the normal port 69 is used.
2384 The purpose for tftpsrcp is to allow a TFTP server to
2385 blindly start the TFTP transfer using the pre-configured
2386 target IP address and UDP port. This has the effect of
2387 "punching through" the (Windows XP) firewall, allowing
2388 the remainder of the TFTP transfer to proceed normally.
2389 A better solution is to properly configure the firewall,
2390 but sometimes that is not allowed.
2392 - Show boot progress:
2393 CONFIG_SHOW_BOOT_PROGRESS
2395 Defining this option allows to add some board-
2396 specific code (calling a user-provided function
2397 "show_boot_progress(int)") that enables you to show
2398 the system's boot progress on some display (for
2399 example, some LED's) on your board. At the moment,
2400 the following checkpoints are implemented:
2402 - Detailed boot stage timing
2403 CONFIG_BOOTSTAGE
2404 Define this option to get detailed timing of each stage
2405 of the boot process.
2407 CONFIG_BOOTSTAGE_USER_COUNT
2408 This is the number of available user bootstage records.
2409 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2410 a new ID will be allocated from this stash. If you exceed
2411 the limit, recording will stop.
2413 CONFIG_BOOTSTAGE_REPORT
2414 Define this to print a report before boot, similar to this:
2416 Timer summary in microseconds:
2417 Mark Elapsed Stage
2418 0 0 reset
2419 3,575,678 3,575,678 board_init_f start
2420 3,575,695 17 arch_cpu_init A9
2421 3,575,777 82 arch_cpu_init done
2422 3,659,598 83,821 board_init_r start
2423 3,910,375 250,777 main_loop
2424 29,916,167 26,005,792 bootm_start
2425 30,361,327 445,160 start_kernel
2427 CONFIG_CMD_BOOTSTAGE
2428 Add a 'bootstage' command which supports printing a report
2429 and un/stashing of bootstage data.
2431 CONFIG_BOOTSTAGE_FDT
2432 Stash the bootstage information in the FDT. A root 'bootstage'
2433 node is created with each bootstage id as a child. Each child
2434 has a 'name' property and either 'mark' containing the
2435 mark time in microsecond, or 'accum' containing the
2436 accumulated time for that bootstage id in microseconds.
2437 For example:
2439 bootstage {
2440 154 {
2441 name = "board_init_f";
2442 mark = <3575678>;
2443 };
2444 170 {
2445 name = "lcd";
2446 accum = <33482>;
2447 };
2448 };
2450 Code in the Linux kernel can find this in /proc/devicetree.
2452 Legacy uImage format:
2454 Arg Where When
2455 1 common/cmd_bootm.c before attempting to boot an image
2456 -1 common/cmd_bootm.c Image header has bad magic number
2457 2 common/cmd_bootm.c Image header has correct magic number
2458 -2 common/cmd_bootm.c Image header has bad checksum
2459 3 common/cmd_bootm.c Image header has correct checksum
2460 -3 common/cmd_bootm.c Image data has bad checksum
2461 4 common/cmd_bootm.c Image data has correct checksum
2462 -4 common/cmd_bootm.c Image is for unsupported architecture
2463 5 common/cmd_bootm.c Architecture check OK
2464 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2465 6 common/cmd_bootm.c Image Type check OK
2466 -6 common/cmd_bootm.c gunzip uncompression error
2467 -7 common/cmd_bootm.c Unimplemented compression type
2468 7 common/cmd_bootm.c Uncompression OK
2469 8 common/cmd_bootm.c No uncompress/copy overwrite error
2470 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2472 9 common/image.c Start initial ramdisk verification
2473 -10 common/image.c Ramdisk header has bad magic number
2474 -11 common/image.c Ramdisk header has bad checksum
2475 10 common/image.c Ramdisk header is OK
2476 -12 common/image.c Ramdisk data has bad checksum
2477 11 common/image.c Ramdisk data has correct checksum
2478 12 common/image.c Ramdisk verification complete, start loading
2479 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2480 13 common/image.c Start multifile image verification
2481 14 common/image.c No initial ramdisk, no multifile, continue.
2483 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2485 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2486 -31 post/post.c POST test failed, detected by post_output_backlog()
2487 -32 post/post.c POST test failed, detected by post_run_single()
2489 34 common/cmd_doc.c before loading a Image from a DOC device
2490 -35 common/cmd_doc.c Bad usage of "doc" command
2491 35 common/cmd_doc.c correct usage of "doc" command
2492 -36 common/cmd_doc.c No boot device
2493 36 common/cmd_doc.c correct boot device
2494 -37 common/cmd_doc.c Unknown Chip ID on boot device
2495 37 common/cmd_doc.c correct chip ID found, device available
2496 -38 common/cmd_doc.c Read Error on boot device
2497 38 common/cmd_doc.c reading Image header from DOC device OK
2498 -39 common/cmd_doc.c Image header has bad magic number
2499 39 common/cmd_doc.c Image header has correct magic number
2500 -40 common/cmd_doc.c Error reading Image from DOC device
2501 40 common/cmd_doc.c Image header has correct magic number
2502 41 common/cmd_ide.c before loading a Image from a IDE device
2503 -42 common/cmd_ide.c Bad usage of "ide" command
2504 42 common/cmd_ide.c correct usage of "ide" command
2505 -43 common/cmd_ide.c No boot device
2506 43 common/cmd_ide.c boot device found
2507 -44 common/cmd_ide.c Device not available
2508 44 common/cmd_ide.c Device available
2509 -45 common/cmd_ide.c wrong partition selected
2510 45 common/cmd_ide.c partition selected
2511 -46 common/cmd_ide.c Unknown partition table
2512 46 common/cmd_ide.c valid partition table found
2513 -47 common/cmd_ide.c Invalid partition type
2514 47 common/cmd_ide.c correct partition type
2515 -48 common/cmd_ide.c Error reading Image Header on boot device
2516 48 common/cmd_ide.c reading Image Header from IDE device OK
2517 -49 common/cmd_ide.c Image header has bad magic number
2518 49 common/cmd_ide.c Image header has correct magic number
2519 -50 common/cmd_ide.c Image header has bad checksum
2520 50 common/cmd_ide.c Image header has correct checksum
2521 -51 common/cmd_ide.c Error reading Image from IDE device
2522 51 common/cmd_ide.c reading Image from IDE device OK
2523 52 common/cmd_nand.c before loading a Image from a NAND device
2524 -53 common/cmd_nand.c Bad usage of "nand" command
2525 53 common/cmd_nand.c correct usage of "nand" command
2526 -54 common/cmd_nand.c No boot device
2527 54 common/cmd_nand.c boot device found
2528 -55 common/cmd_nand.c Unknown Chip ID on boot device
2529 55 common/cmd_nand.c correct chip ID found, device available
2530 -56 common/cmd_nand.c Error reading Image Header on boot device
2531 56 common/cmd_nand.c reading Image Header from NAND device OK
2532 -57 common/cmd_nand.c Image header has bad magic number
2533 57 common/cmd_nand.c Image header has correct magic number
2534 -58 common/cmd_nand.c Error reading Image from NAND device
2535 58 common/cmd_nand.c reading Image from NAND device OK
2537 -60 common/env_common.c Environment has a bad CRC, using default
2539 64 net/eth.c starting with Ethernet configuration.
2540 -64 net/eth.c no Ethernet found.
2541 65 net/eth.c Ethernet found.
2543 -80 common/cmd_net.c usage wrong
2544 80 common/cmd_net.c before calling NetLoop()
2545 -81 common/cmd_net.c some error in NetLoop() occurred
2546 81 common/cmd_net.c NetLoop() back without error
2547 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2548 82 common/cmd_net.c trying automatic boot
2549 83 common/cmd_net.c running "source" command
2550 -83 common/cmd_net.c some error in automatic boot or "source" command
2551 84 common/cmd_net.c end without errors
2553 FIT uImage format:
2555 Arg Where When
2556 100 common/cmd_bootm.c Kernel FIT Image has correct format
2557 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2558 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2559 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2560 102 common/cmd_bootm.c Kernel unit name specified
2561 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2562 103 common/cmd_bootm.c Found configuration node
2563 104 common/cmd_bootm.c Got kernel subimage node offset
2564 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2565 105 common/cmd_bootm.c Kernel subimage hash verification OK
2566 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2567 106 common/cmd_bootm.c Architecture check OK
2568 -106 common/cmd_bootm.c Kernel subimage has wrong type
2569 107 common/cmd_bootm.c Kernel subimage type OK
2570 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2571 108 common/cmd_bootm.c Got kernel subimage data/size
2572 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2573 -109 common/cmd_bootm.c Can't get kernel subimage type
2574 -110 common/cmd_bootm.c Can't get kernel subimage comp
2575 -111 common/cmd_bootm.c Can't get kernel subimage os
2576 -112 common/cmd_bootm.c Can't get kernel subimage load address
2577 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2579 120 common/image.c Start initial ramdisk verification
2580 -120 common/image.c Ramdisk FIT image has incorrect format
2581 121 common/image.c Ramdisk FIT image has correct format
2582 122 common/image.c No ramdisk subimage unit name, using configuration
2583 -122 common/image.c Can't get configuration for ramdisk subimage
2584 123 common/image.c Ramdisk unit name specified
2585 -124 common/image.c Can't get ramdisk subimage node offset
2586 125 common/image.c Got ramdisk subimage node offset
2587 -125 common/image.c Ramdisk subimage hash verification failed
2588 126 common/image.c Ramdisk subimage hash verification OK
2589 -126 common/image.c Ramdisk subimage for unsupported architecture
2590 127 common/image.c Architecture check OK
2591 -127 common/image.c Can't get ramdisk subimage data/size
2592 128 common/image.c Got ramdisk subimage data/size
2593 129 common/image.c Can't get ramdisk load address
2594 -129 common/image.c Got ramdisk load address
2596 -130 common/cmd_doc.c Incorrect FIT image format
2597 131 common/cmd_doc.c FIT image format OK
2599 -140 common/cmd_ide.c Incorrect FIT image format
2600 141 common/cmd_ide.c FIT image format OK
2602 -150 common/cmd_nand.c Incorrect FIT image format
2603 151 common/cmd_nand.c FIT image format OK
2605 - FIT image support:
2606 CONFIG_FIT
2607 Enable support for the FIT uImage format.
2609 CONFIG_FIT_BEST_MATCH
2610 When no configuration is explicitly selected, default to the
2611 one whose fdt's compatibility field best matches that of
2612 U-Boot itself. A match is considered "best" if it matches the
2613 most specific compatibility entry of U-Boot's fdt's root node.
2614 The order of entries in the configuration's fdt is ignored.
2616 - Standalone program support:
2617 CONFIG_STANDALONE_LOAD_ADDR
2619 This option defines a board specific value for the
2620 address where standalone program gets loaded, thus
2621 overwriting the architecture dependent default
2622 settings.
2624 - Frame Buffer Address:
2625 CONFIG_FB_ADDR
2627 Define CONFIG_FB_ADDR if you want to use specific
2628 address for frame buffer.
2629 Then system will reserve the frame buffer address to
2630 defined address instead of lcd_setmem (this function
2631 grabs the memory for frame buffer by panel's size).
2633 Please see board_init_f function.
2635 - Automatic software updates via TFTP server
2636 CONFIG_UPDATE_TFTP
2637 CONFIG_UPDATE_TFTP_CNT_MAX
2638 CONFIG_UPDATE_TFTP_MSEC_MAX
2640 These options enable and control the auto-update feature;
2641 for a more detailed description refer to doc/README.update.
2643 - MTD Support (mtdparts command, UBI support)
2644 CONFIG_MTD_DEVICE
2646 Adds the MTD device infrastructure from the Linux kernel.
2647 Needed for mtdparts command support.
2649 CONFIG_MTD_PARTITIONS
2651 Adds the MTD partitioning infrastructure from the Linux
2652 kernel. Needed for UBI support.
2654 - SPL framework
2655 CONFIG_SPL
2656 Enable building of SPL globally.
2658 CONFIG_SPL_LDSCRIPT
2659 LDSCRIPT for linking the SPL binary.
2661 CONFIG_SPL_MAX_SIZE
2662 Maximum binary size (text, data and rodata) of the SPL binary.
2664 CONFIG_SPL_TEXT_BASE
2665 TEXT_BASE for linking the SPL binary.
2667 CONFIG_SPL_RELOC_TEXT_BASE
2668 Address to relocate to. If unspecified, this is equal to
2669 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2671 CONFIG_SPL_BSS_START_ADDR
2672 Link address for the BSS within the SPL binary.
2674 CONFIG_SPL_BSS_MAX_SIZE
2675 Maximum binary size of the BSS section of the SPL binary.
2677 CONFIG_SPL_STACK
2678 Adress of the start of the stack SPL will use
2680 CONFIG_SPL_RELOC_STACK
2681 Adress of the start of the stack SPL will use after
2682 relocation. If unspecified, this is equal to
2683 CONFIG_SPL_STACK.
2685 CONFIG_SYS_SPL_MALLOC_START
2686 Starting address of the malloc pool used in SPL.
2688 CONFIG_SYS_SPL_MALLOC_SIZE
2689 The size of the malloc pool used in SPL.
2691 CONFIG_SPL_FRAMEWORK
2692 Enable the SPL framework under common/. This framework
2693 supports MMC, NAND and YMODEM loading of U-Boot and NAND
2694 NAND loading of the Linux Kernel.
2696 CONFIG_SPL_DISPLAY_PRINT
2697 For ARM, enable an optional function to print more information
2698 about the running system.
2700 CONFIG_SPL_INIT_MINIMAL
2701 Arch init code should be built for a very small image
2703 CONFIG_SPL_LIBCOMMON_SUPPORT
2704 Support for common/libcommon.o in SPL binary
2706 CONFIG_SPL_LIBDISK_SUPPORT
2707 Support for disk/libdisk.o in SPL binary
2709 CONFIG_SPL_I2C_SUPPORT
2710 Support for drivers/i2c/libi2c.o in SPL binary
2712 CONFIG_SPL_GPIO_SUPPORT
2713 Support for drivers/gpio/libgpio.o in SPL binary
2715 CONFIG_SPL_MMC_SUPPORT
2716 Support for drivers/mmc/libmmc.o in SPL binary
2718 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
2719 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
2720 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
2721 Address, size and partition on the MMC to load U-Boot from
2722 when the MMC is being used in raw mode.
2724 CONFIG_SPL_FAT_SUPPORT
2725 Support for fs/fat/libfat.o in SPL binary
2727 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
2728 Filename to read to load U-Boot when reading from FAT
2730 CONFIG_SPL_NAND_BASE
2731 Include nand_base.c in the SPL. Requires
2732 CONFIG_SPL_NAND_DRIVERS.
2734 CONFIG_SPL_NAND_DRIVERS
2735 SPL uses normal NAND drivers, not minimal drivers.
2737 CONFIG_SPL_NAND_ECC
2738 Include standard software ECC in the SPL
2740 CONFIG_SPL_NAND_SIMPLE
2741 Support for NAND boot using simple NAND drivers that
2742 expose the cmd_ctrl() interface.
2744 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2745 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2746 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2747 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2748 CONFIG_SYS_NAND_ECCBYTES
2749 Defines the size and behavior of the NAND that SPL uses
2750 to read U-Boot
2752 CONFIG_SYS_NAND_U_BOOT_OFFS
2753 Location in NAND to read U-Boot from
2755 CONFIG_SYS_NAND_U_BOOT_DST
2756 Location in memory to load U-Boot to
2758 CONFIG_SYS_NAND_U_BOOT_SIZE
2759 Size of image to load
2761 CONFIG_SYS_NAND_U_BOOT_START
2762 Entry point in loaded image to jump to
2764 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2765 Define this if you need to first read the OOB and then the
2766 data. This is used for example on davinci plattforms.
2768 CONFIG_SPL_OMAP3_ID_NAND
2769 Support for an OMAP3-specific set of functions to return the
2770 ID and MFR of the first attached NAND chip, if present.
2772 CONFIG_SPL_SERIAL_SUPPORT
2773 Support for drivers/serial/libserial.o in SPL binary
2775 CONFIG_SPL_SPI_FLASH_SUPPORT
2776 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2778 CONFIG_SPL_SPI_SUPPORT
2779 Support for drivers/spi/libspi.o in SPL binary
2781 CONFIG_SPL_RAM_DEVICE
2782 Support for running image already present in ram, in SPL binary
2784 CONFIG_SPL_LIBGENERIC_SUPPORT
2785 Support for lib/libgeneric.o in SPL binary
2787 CONFIG_SPL_TARGET
2788 Final target image containing SPL and payload. Some SPLs
2789 use an arch-specific makefile fragment instead, for
2790 example if more than one image needs to be produced.
2792 Modem Support:
2793 --------------
2795 [so far only for SMDK2400 boards]
2797 - Modem support enable:
2798 CONFIG_MODEM_SUPPORT
2800 - RTS/CTS Flow control enable:
2801 CONFIG_HWFLOW
2803 - Modem debug support:
2804 CONFIG_MODEM_SUPPORT_DEBUG
2806 Enables debugging stuff (char screen[1024], dbg())
2807 for modem support. Useful only with BDI2000.
2809 - Interrupt support (PPC):
2811 There are common interrupt_init() and timer_interrupt()
2812 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2813 for CPU specific initialization. interrupt_init_cpu()
2814 should set decrementer_count to appropriate value. If
2815 CPU resets decrementer automatically after interrupt
2816 (ppc4xx) it should set decrementer_count to zero.
2817 timer_interrupt() calls timer_interrupt_cpu() for CPU
2818 specific handling. If board has watchdog / status_led
2819 / other_activity_monitor it works automatically from
2820 general timer_interrupt().
2822 - General:
2824 In the target system modem support is enabled when a
2825 specific key (key combination) is pressed during
2826 power-on. Otherwise U-Boot will boot normally
2827 (autoboot). The key_pressed() function is called from
2828 board_init(). Currently key_pressed() is a dummy
2829 function, returning 1 and thus enabling modem
2830 initialization.
2832 If there are no modem init strings in the
2833 environment, U-Boot proceed to autoboot; the
2834 previous output (banner, info printfs) will be
2835 suppressed, though.
2837 See also: doc/README.Modem
2839 Board initialization settings:
2840 ------------------------------
2842 During Initialization u-boot calls a number of board specific functions
2843 to allow the preparation of board specific prerequisites, e.g. pin setup
2844 before drivers are initialized. To enable these callbacks the
2845 following configuration macros have to be defined. Currently this is
2846 architecture specific, so please check arch/your_architecture/lib/board.c
2847 typically in board_init_f() and board_init_r().
2849 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2850 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2851 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2852 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2854 Configuration Settings:
2855 -----------------------
2857 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2858 undefine this when you're short of memory.
2860 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2861 width of the commands listed in the 'help' command output.
2863 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2864 prompt for user input.
2866 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2868 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2870 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2872 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2873 the application (usually a Linux kernel) when it is
2874 booted
2876 - CONFIG_SYS_BAUDRATE_TABLE:
2877 List of legal baudrate settings for this board.
2879 - CONFIG_SYS_CONSOLE_INFO_QUIET
2880 Suppress display of console information at boot.
2882 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2883 If the board specific function
2884 extern int overwrite_console (void);
2885 returns 1, the stdin, stderr and stdout are switched to the
2886 serial port, else the settings in the environment are used.
2888 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2889 Enable the call to overwrite_console().
2891 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2892 Enable overwrite of previous console environment settings.
2894 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2895 Begin and End addresses of the area used by the
2896 simple memory test.
2898 - CONFIG_SYS_ALT_MEMTEST:
2899 Enable an alternate, more extensive memory test.
2901 - CONFIG_SYS_MEMTEST_SCRATCH:
2902 Scratch address used by the alternate memory test
2903 You only need to set this if address zero isn't writeable
2905 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2906 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2907 this specified memory area will get subtracted from the top
2908 (end) of RAM and won't get "touched" at all by U-Boot. By
2909 fixing up gd->ram_size the Linux kernel should gets passed
2910 the now "corrected" memory size and won't touch it either.
2911 This should work for arch/ppc and arch/powerpc. Only Linux
2912 board ports in arch/powerpc with bootwrapper support that
2913 recalculate the memory size from the SDRAM controller setup
2914 will have to get fixed in Linux additionally.
2916 This option can be used as a workaround for the 440EPx/GRx
2917 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2918 be touched.
2920 WARNING: Please make sure that this value is a multiple of
2921 the Linux page size (normally 4k). If this is not the case,
2922 then the end address of the Linux memory will be located at a
2923 non page size aligned address and this could cause major
2924 problems.
2926 - CONFIG_SYS_TFTP_LOADADDR:
2927 Default load address for network file downloads
2929 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2930 Enable temporary baudrate change while serial download
2932 - CONFIG_SYS_SDRAM_BASE:
2933 Physical start address of SDRAM. _Must_ be 0 here.
2935 - CONFIG_SYS_MBIO_BASE:
2936 Physical start address of Motherboard I/O (if using a
2937 Cogent motherboard)
2939 - CONFIG_SYS_FLASH_BASE:
2940 Physical start address of Flash memory.
2942 - CONFIG_SYS_MONITOR_BASE:
2943 Physical start address of boot monitor code (set by
2944 make config files to be same as the text base address
2945 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2946 CONFIG_SYS_FLASH_BASE when booting from flash.
2948 - CONFIG_SYS_MONITOR_LEN:
2949 Size of memory reserved for monitor code, used to
2950 determine _at_compile_time_ (!) if the environment is
2951 embedded within the U-Boot image, or in a separate
2952 flash sector.
2954 - CONFIG_SYS_MALLOC_LEN:
2955 Size of DRAM reserved for malloc() use.
2957 - CONFIG_SYS_BOOTM_LEN:
2958 Normally compressed uImages are limited to an
2959 uncompressed size of 8 MBytes. If this is not enough,
2960 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2961 to adjust this setting to your needs.
2963 - CONFIG_SYS_BOOTMAPSZ:
2964 Maximum size of memory mapped by the startup code of
2965 the Linux kernel; all data that must be processed by
2966 the Linux kernel (bd_info, boot arguments, FDT blob if
2967 used) must be put below this limit, unless "bootm_low"
2968 enviroment variable is defined and non-zero. In such case
2969 all data for the Linux kernel must be between "bootm_low"
2970 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2971 variable "bootm_mapsize" will override the value of
2972 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2973 then the value in "bootm_size" will be used instead.
2975 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2976 Enable initrd_high functionality. If defined then the
2977 initrd_high feature is enabled and the bootm ramdisk subcommand
2978 is enabled.
2980 - CONFIG_SYS_BOOT_GET_CMDLINE:
2981 Enables allocating and saving kernel cmdline in space between
2982 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2984 - CONFIG_SYS_BOOT_GET_KBD:
2985 Enables allocating and saving a kernel copy of the bd_info in
2986 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2988 - CONFIG_SYS_MAX_FLASH_BANKS:
2989 Max number of Flash memory banks
2991 - CONFIG_SYS_MAX_FLASH_SECT:
2992 Max number of sectors on a Flash chip
2994 - CONFIG_SYS_FLASH_ERASE_TOUT:
2995 Timeout for Flash erase operations (in ms)
2997 - CONFIG_SYS_FLASH_WRITE_TOUT:
2998 Timeout for Flash write operations (in ms)
3000 - CONFIG_SYS_FLASH_LOCK_TOUT
3001 Timeout for Flash set sector lock bit operation (in ms)
3003 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3004 Timeout for Flash clear lock bits operation (in ms)
3006 - CONFIG_SYS_FLASH_PROTECTION
3007 If defined, hardware flash sectors protection is used
3008 instead of U-Boot software protection.
3010 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3012 Enable TFTP transfers directly to flash memory;
3013 without this option such a download has to be
3014 performed in two steps: (1) download to RAM, and (2)
3015 copy from RAM to flash.
3017 The two-step approach is usually more reliable, since
3018 you can check if the download worked before you erase
3019 the flash, but in some situations (when system RAM is
3020 too limited to allow for a temporary copy of the
3021 downloaded image) this option may be very useful.
3023 - CONFIG_SYS_FLASH_CFI:
3024 Define if the flash driver uses extra elements in the
3025 common flash structure for storing flash geometry.
3027 - CONFIG_FLASH_CFI_DRIVER
3028 This option also enables the building of the cfi_flash driver
3029 in the drivers directory
3031 - CONFIG_FLASH_CFI_MTD
3032 This option enables the building of the cfi_mtd driver
3033 in the drivers directory. The driver exports CFI flash
3034 to the MTD layer.
3036 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3037 Use buffered writes to flash.
3039 - CONFIG_FLASH_SPANSION_S29WS_N
3040 s29ws-n MirrorBit flash has non-standard addresses for buffered
3041 write commands.
3043 - CONFIG_SYS_FLASH_QUIET_TEST
3044 If this option is defined, the common CFI flash doesn't
3045 print it's warning upon not recognized FLASH banks. This
3046 is useful, if some of the configured banks are only
3047 optionally available.
3049 - CONFIG_FLASH_SHOW_PROGRESS
3050 If defined (must be an integer), print out countdown
3051 digits and dots. Recommended value: 45 (9..1) for 80
3052 column displays, 15 (3..1) for 40 column displays.
3054 - CONFIG_SYS_RX_ETH_BUFFER:
3055 Defines the number of Ethernet receive buffers. On some
3056 Ethernet controllers it is recommended to set this value
3057 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3058 buffers can be full shortly after enabling the interface
3059 on high Ethernet traffic.
3060 Defaults to 4 if not defined.
3062 - CONFIG_ENV_MAX_ENTRIES
3064 Maximum number of entries in the hash table that is used
3065 internally to store the environment settings. The default
3066 setting is supposed to be generous and should work in most
3067 cases. This setting can be used to tune behaviour; see
3068 lib/hashtable.c for details.
3070 The following definitions that deal with the placement and management
3071 of environment data (variable area); in general, we support the
3072 following configurations:
3074 - CONFIG_BUILD_ENVCRC:
3076 Builds up envcrc with the target environment so that external utils
3077 may easily extract it and embed it in final U-Boot images.
3079 - CONFIG_ENV_IS_IN_FLASH:
3081 Define this if the environment is in flash memory.
3083 a) The environment occupies one whole flash sector, which is
3084 "embedded" in the text segment with the U-Boot code. This
3085 happens usually with "bottom boot sector" or "top boot
3086 sector" type flash chips, which have several smaller
3087 sectors at the start or the end. For instance, such a
3088 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3089 such a case you would place the environment in one of the
3090 4 kB sectors - with U-Boot code before and after it. With
3091 "top boot sector" type flash chips, you would put the
3092 environment in one of the last sectors, leaving a gap
3093 between U-Boot and the environment.
3095 - CONFIG_ENV_OFFSET:
3097 Offset of environment data (variable area) to the
3098 beginning of flash memory; for instance, with bottom boot
3099 type flash chips the second sector can be used: the offset
3100 for this sector is given here.
3102 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3104 - CONFIG_ENV_ADDR:
3106 This is just another way to specify the start address of
3107 the flash sector containing the environment (instead of
3108 CONFIG_ENV_OFFSET).
3110 - CONFIG_ENV_SECT_SIZE:
3112 Size of the sector containing the environment.
3115 b) Sometimes flash chips have few, equal sized, BIG sectors.
3116 In such a case you don't want to spend a whole sector for
3117 the environment.
3119 - CONFIG_ENV_SIZE:
3121 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3122 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3123 of this flash sector for the environment. This saves
3124 memory for the RAM copy of the environment.
3126 It may also save flash memory if you decide to use this
3127 when your environment is "embedded" within U-Boot code,
3128 since then the remainder of the flash sector could be used
3129 for U-Boot code. It should be pointed out that this is
3130 STRONGLY DISCOURAGED from a robustness point of view:
3131 updating the environment in flash makes it always
3132 necessary to erase the WHOLE sector. If something goes
3133 wrong before the contents has been restored from a copy in
3134 RAM, your target system will be dead.
3136 - CONFIG_ENV_ADDR_REDUND
3137 CONFIG_ENV_SIZE_REDUND
3139 These settings describe a second storage area used to hold
3140 a redundant copy of the environment data, so that there is
3141 a valid backup copy in case there is a power failure during
3142 a "saveenv" operation.
3144 BE CAREFUL! Any changes to the flash layout, and some changes to the
3145 source code will make it necessary to adapt <board>/u-boot.lds*
3146 accordingly!
3149 - CONFIG_ENV_IS_IN_NVRAM:
3151 Define this if you have some non-volatile memory device
3152 (NVRAM, battery buffered SRAM) which you want to use for the
3153 environment.
3155 - CONFIG_ENV_ADDR:
3156 - CONFIG_ENV_SIZE:
3158 These two #defines are used to determine the memory area you
3159 want to use for environment. It is assumed that this memory
3160 can just be read and written to, without any special
3161 provision.
3163 BE CAREFUL! The first access to the environment happens quite early
3164 in U-Boot initalization (when we try to get the setting of for the
3165 console baudrate). You *MUST* have mapped your NVRAM area then, or
3166 U-Boot will hang.
3168 Please note that even with NVRAM we still use a copy of the
3169 environment in RAM: we could work on NVRAM directly, but we want to
3170 keep settings there always unmodified except somebody uses "saveenv"
3171 to save the current settings.
3174 - CONFIG_ENV_IS_IN_EEPROM:
3176 Use this if you have an EEPROM or similar serial access
3177 device and a driver for it.
3179 - CONFIG_ENV_OFFSET:
3180 - CONFIG_ENV_SIZE:
3182 These two #defines specify the offset and size of the
3183 environment area within the total memory of your EEPROM.
3185 - CONFIG_SYS_I2C_EEPROM_ADDR:
3186 If defined, specified the chip address of the EEPROM device.
3187 The default address is zero.
3189 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3190 If defined, the number of bits used to address bytes in a
3191 single page in the EEPROM device. A 64 byte page, for example
3192 would require six bits.
3194 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3195 If defined, the number of milliseconds to delay between
3196 page writes. The default is zero milliseconds.
3198 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3199 The length in bytes of the EEPROM memory array address. Note
3200 that this is NOT the chip address length!
3202 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3203 EEPROM chips that implement "address overflow" are ones
3204 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3205 address and the extra bits end up in the "chip address" bit
3206 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3207 byte chips.
3209 Note that we consider the length of the address field to
3210 still be one byte because the extra address bits are hidden
3211 in the chip address.
3213 - CONFIG_SYS_EEPROM_SIZE:
3214 The size in bytes of the EEPROM device.
3216 - CONFIG_ENV_EEPROM_IS_ON_I2C
3217 define this, if you have I2C and SPI activated, and your
3218 EEPROM, which holds the environment, is on the I2C bus.
3220 - CONFIG_I2C_ENV_EEPROM_BUS
3221 if you have an Environment on an EEPROM reached over
3222 I2C muxes, you can define here, how to reach this
3223 EEPROM. For example:
3225 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
3227 EEPROM which holds the environment, is reached over
3228 a pca9547 i2c mux with address 0x70, channel 3.
3230 - CONFIG_ENV_IS_IN_DATAFLASH:
3232 Define this if you have a DataFlash memory device which you
3233 want to use for the environment.
3235 - CONFIG_ENV_OFFSET:
3236 - CONFIG_ENV_ADDR:
3237 - CONFIG_ENV_SIZE:
3239 These three #defines specify the offset and size of the
3240 environment area within the total memory of your DataFlash placed
3241 at the specified address.
3243 - CONFIG_ENV_IS_IN_REMOTE:
3245 Define this if you have a remote memory space which you
3246 want to use for the local device's environment.
3248 - CONFIG_ENV_ADDR:
3249 - CONFIG_ENV_SIZE:
3251 These two #defines specify the address and size of the
3252 environment area within the remote memory space. The
3253 local device can get the environment from remote memory
3254 space by SRIO or PCIE links.
3256 BE CAREFUL! For some special cases, the local device can not use
3257 "saveenv" command. For example, the local device will get the
3258 environment stored in a remote NOR flash by SRIO or PCIE link,
3259 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3261 - CONFIG_ENV_IS_IN_NAND:
3263 Define this if you have a NAND device which you want to use
3264 for the environment.
3266 - CONFIG_ENV_OFFSET:
3267 - CONFIG_ENV_SIZE:
3269 These two #defines specify the offset and size of the environment
3270 area within the first NAND device. CONFIG_ENV_OFFSET must be
3271 aligned to an erase block boundary.
3273 - CONFIG_ENV_OFFSET_REDUND (optional):
3275 This setting describes a second storage area of CONFIG_ENV_SIZE
3276 size used to hold a redundant copy of the environment data, so
3277 that there is a valid backup copy in case there is a power failure
3278 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3279 aligned to an erase block boundary.
3281 - CONFIG_ENV_RANGE (optional):
3283 Specifies the length of the region in which the environment
3284 can be written. This should be a multiple of the NAND device's
3285 block size. Specifying a range with more erase blocks than
3286 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3287 the range to be avoided.
3289 - CONFIG_ENV_OFFSET_OOB (optional):
3291 Enables support for dynamically retrieving the offset of the
3292 environment from block zero's out-of-band data. The
3293 "nand env.oob" command can be used to record this offset.
3294 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3295 using CONFIG_ENV_OFFSET_OOB.
3297 - CONFIG_NAND_ENV_DST
3299 Defines address in RAM to which the nand_spl code should copy the
3300 environment. If redundant environment is used, it will be copied to
3301 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3303 - CONFIG_SYS_SPI_INIT_OFFSET
3305 Defines offset to the initial SPI buffer area in DPRAM. The
3306 area is used at an early stage (ROM part) if the environment
3307 is configured to reside in the SPI EEPROM: We need a 520 byte
3308 scratch DPRAM area. It is used between the two initialization
3309 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
3310 to be a good choice since it makes it far enough from the
3311 start of the data area as well as from the stack pointer.
3313 Please note that the environment is read-only until the monitor
3314 has been relocated to RAM and a RAM copy of the environment has been
3315 created; also, when using EEPROM you will have to use getenv_f()
3316 until then to read environment variables.
3318 The environment is protected by a CRC32 checksum. Before the monitor
3319 is relocated into RAM, as a result of a bad CRC you will be working
3320 with the compiled-in default environment - *silently*!!! [This is
3321 necessary, because the first environment variable we need is the
3322 "baudrate" setting for the console - if we have a bad CRC, we don't
3323 have any device yet where we could complain.]
3325 Note: once the monitor has been relocated, then it will complain if
3326 the default environment is used; a new CRC is computed as soon as you
3327 use the "saveenv" command to store a valid environment.
3329 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3330 Echo the inverted Ethernet link state to the fault LED.
3332 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3333 also needs to be defined.
3335 - CONFIG_SYS_FAULT_MII_ADDR:
3336 MII address of the PHY to check for the Ethernet link state.
3338 - CONFIG_NS16550_MIN_FUNCTIONS:
3339 Define this if you desire to only have use of the NS16550_init
3340 and NS16550_putc functions for the serial driver located at
3341 drivers/serial/ns16550.c. This option is useful for saving
3342 space for already greatly restricted images, including but not
3343 limited to NAND_SPL configurations.
3345 Low Level (hardware related) configuration options:
3346 ---------------------------------------------------
3348 - CONFIG_SYS_CACHELINE_SIZE:
3349 Cache Line Size of the CPU.
3351 - CONFIG_SYS_DEFAULT_IMMR:
3352 Default address of the IMMR after system reset.
3354 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
3355 and RPXsuper) to be able to adjust the position of
3356 the IMMR register after a reset.
3358 - CONFIG_SYS_CCSRBAR_DEFAULT:
3359 Default (power-on reset) physical address of CCSR on Freescale
3360 PowerPC SOCs.
3362 - CONFIG_SYS_CCSRBAR:
3363 Virtual address of CCSR. On a 32-bit build, this is typically
3364 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3366 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
3367 for cross-platform code that uses that macro instead.
3369 - CONFIG_SYS_CCSRBAR_PHYS:
3370 Physical address of CCSR. CCSR can be relocated to a new
3371 physical address, if desired. In this case, this macro should
3372 be set to that address. Otherwise, it should be set to the
3373 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3374 is typically relocated on 36-bit builds. It is recommended
3375 that this macro be defined via the _HIGH and _LOW macros:
3377 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3378 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3380 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3381 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3382 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3383 used in assembly code, so it must not contain typecasts or
3384 integer size suffixes (e.g. "ULL").
3386 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3387 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3388 used in assembly code, so it must not contain typecasts or
3389 integer size suffixes (e.g. "ULL").
3391 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3392 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3393 forced to a value that ensures that CCSR is not relocated.
3395 - Floppy Disk Support:
3396 CONFIG_SYS_FDC_DRIVE_NUMBER
3398 the default drive number (default value 0)
3400 CONFIG_SYS_ISA_IO_STRIDE
3402 defines the spacing between FDC chipset registers
3403 (default value 1)
3405 CONFIG_SYS_ISA_IO_OFFSET
3407 defines the offset of register from address. It
3408 depends on which part of the data bus is connected to
3409 the FDC chipset. (default value 0)
3411 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3412 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3413 default value.
3415 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3416 fdc_hw_init() is called at the beginning of the FDC
3417 setup. fdc_hw_init() must be provided by the board
3418 source code. It is used to make hardware dependant
3419 initializations.
3421 - CONFIG_IDE_AHB:
3422 Most IDE controllers were designed to be connected with PCI
3423 interface. Only few of them were designed for AHB interface.
3424 When software is doing ATA command and data transfer to
3425 IDE devices through IDE-AHB controller, some additional
3426 registers accessing to these kind of IDE-AHB controller
3427 is requierd.
3429 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3430 DO NOT CHANGE unless you know exactly what you're
3431 doing! (11-4) [MPC8xx/82xx systems only]
3433 - CONFIG_SYS_INIT_RAM_ADDR:
3435 Start address of memory area that can be used for
3436 initial data and stack; please note that this must be
3437 writable memory that is working WITHOUT special
3438 initialization, i. e. you CANNOT use normal RAM which
3439 will become available only after programming the
3440 memory controller and running certain initialization
3441 sequences.
3443 U-Boot uses the following memory types:
3444 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3445 - MPC824X: data cache
3446 - PPC4xx: data cache
3448 - CONFIG_SYS_GBL_DATA_OFFSET:
3450 Offset of the initial data structure in the memory
3451 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3452 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3453 data is located at the end of the available space
3454 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3455 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3456 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3457 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3459 Note:
3460 On the MPC824X (or other systems that use the data
3461 cache for initial memory) the address chosen for
3462 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3463 point to an otherwise UNUSED address space between
3464 the top of RAM and the start of the PCI space.
3466 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3468 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3470 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3472 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3474 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3476 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3478 - CONFIG_SYS_OR_TIMING_SDRAM:
3479 SDRAM timing
3481 - CONFIG_SYS_MAMR_PTA:
3482 periodic timer for refresh
3484 - CONFIG_SYS_DER: Debug Event Register (37-47)
3486 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3487 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3488 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3489 CONFIG_SYS_BR1_PRELIM:
3490 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3492 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3493 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3494 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3495 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3497 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3498 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3499 Machine Mode Register and Memory Periodic Timer
3500 Prescaler definitions (SDRAM timing)
3502 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3503 enable I2C microcode relocation patch (MPC8xx);
3504 define relocation offset in DPRAM [DSP2]
3506 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3507 enable SMC microcode relocation patch (MPC8xx);
3508 define relocation offset in DPRAM [SMC1]
3510 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3511 enable SPI microcode relocation patch (MPC8xx);
3512 define relocation offset in DPRAM [SCC4]
3514 - CONFIG_SYS_USE_OSCCLK:
3515 Use OSCM clock mode on MBX8xx board. Be careful,
3516 wrong setting might damage your board. Read
3517 doc/README.MBX before setting this variable!
3519 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3520 Offset of the bootmode word in DPRAM used by post
3521 (Power On Self Tests). This definition overrides
3522 #define'd default value in commproc.h resp.
3523 cpm_8260.h.
3525 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3526 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3527 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3528 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3529 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3530 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3531 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3532 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3533 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3535 - CONFIG_PCI_DISABLE_PCIE:
3536 Disable PCI-Express on systems where it is supported but not
3537 required.
3539 - CONFIG_PCI_ENUM_ONLY
3540 Only scan through and get the devices on the busses.
3541 Don't do any setup work, presumably because someone or
3542 something has already done it, and we don't need to do it
3543 a second time. Useful for platforms that are pre-booted
3544 by coreboot or similar.
3546 - CONFIG_SYS_SRIO:
3547 Chip has SRIO or not
3549 - CONFIG_SRIO1:
3550 Board has SRIO 1 port available
3552 - CONFIG_SRIO2:
3553 Board has SRIO 2 port available
3555 - CONFIG_SYS_SRIOn_MEM_VIRT:
3556 Virtual Address of SRIO port 'n' memory region
3558 - CONFIG_SYS_SRIOn_MEM_PHYS:
3559 Physical Address of SRIO port 'n' memory region
3561 - CONFIG_SYS_SRIOn_MEM_SIZE:
3562 Size of SRIO port 'n' memory region
3564 - CONFIG_SYS_NDFC_16
3565 Defined to tell the NDFC that the NAND chip is using a
3566 16 bit bus.
3568 - CONFIG_SYS_NDFC_EBC0_CFG
3569 Sets the EBC0_CFG register for the NDFC. If not defined
3570 a default value will be used.
3572 - CONFIG_SPD_EEPROM
3573 Get DDR timing information from an I2C EEPROM. Common
3574 with pluggable memory modules such as SODIMMs
3576 SPD_EEPROM_ADDRESS
3577 I2C address of the SPD EEPROM
3579 - CONFIG_SYS_SPD_BUS_NUM
3580 If SPD EEPROM is on an I2C bus other than the first
3581 one, specify here. Note that the value must resolve
3582 to something your driver can deal with.
3584 - CONFIG_SYS_DDR_RAW_TIMING
3585 Get DDR timing information from other than SPD. Common with
3586 soldered DDR chips onboard without SPD. DDR raw timing
3587 parameters are extracted from datasheet and hard-coded into
3588 header files or board specific files.
3590 - CONFIG_FSL_DDR_INTERACTIVE
3591 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3593 - CONFIG_SYS_83XX_DDR_USES_CS0
3594 Only for 83xx systems. If specified, then DDR should
3595 be configured using CS0 and CS1 instead of CS2 and CS3.
3597 - CONFIG_ETHER_ON_FEC[12]
3598 Define to enable FEC[12] on a 8xx series processor.
3600 - CONFIG_FEC[12]_PHY
3601 Define to the hardcoded PHY address which corresponds
3602 to the given FEC; i. e.
3603 #define CONFIG_FEC1_PHY 4
3604 means that the PHY with address 4 is connected to FEC1
3606 When set to -1, means to probe for first available.
3608 - CONFIG_FEC[12]_PHY_NORXERR
3609 The PHY does not have a RXERR line (RMII only).
3610 (so program the FEC to ignore it).
3612 - CONFIG_RMII
3613 Enable RMII mode for all FECs.
3614 Note that this is a global option, we can't
3615 have one FEC in standard MII mode and another in RMII mode.
3617 - CONFIG_CRC32_VERIFY
3618 Add a verify option to the crc32 command.
3619 The syntax is:
3621 => crc32 -v <address> <count> <crc32>
3623 Where address/count indicate a memory area
3624 and crc32 is the correct crc32 which the
3625 area should have.
3627 - CONFIG_LOOPW
3628 Add the "loopw" memory command. This only takes effect if
3629 the memory commands are activated globally (CONFIG_CMD_MEM).
3631 - CONFIG_MX_CYCLIC
3632 Add the "mdc" and "mwc" memory commands. These are cyclic
3633 "md/mw" commands.
3634 Examples:
3636 => mdc.b 10 4 500
3637 This command will print 4 bytes (10,11,12,13) each 500 ms.
3639 => mwc.l 100 12345678 10
3640 This command will write 12345678 to address 100 all 10 ms.
3642 This only takes effect if the memory commands are activated
3643 globally (CONFIG_CMD_MEM).
3645 - CONFIG_SKIP_LOWLEVEL_INIT
3646 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3647 low level initializations (like setting up the memory
3648 controller) are omitted and/or U-Boot does not
3649 relocate itself into RAM.
3651 Normally this variable MUST NOT be defined. The only
3652 exception is when U-Boot is loaded (to RAM) by some
3653 other boot loader or by a debugger which performs
3654 these initializations itself.
3656 - CONFIG_SPL_BUILD
3657 Modifies the behaviour of start.S when compiling a loader
3658 that is executed before the actual U-Boot. E.g. when
3659 compiling a NAND SPL.
3661 - CONFIG_USE_ARCH_MEMCPY
3662 CONFIG_USE_ARCH_MEMSET
3663 If these options are used a optimized version of memcpy/memset will
3664 be used if available. These functions may be faster under some
3665 conditions but may increase the binary size.
3667 - CONFIG_X86_NO_RESET_VECTOR
3668 If defined, the x86 reset vector code is excluded. You will need
3669 to do this when U-Boot is running from Coreboot.
3671 Freescale QE/FMAN Firmware Support:
3672 -----------------------------------
3674 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3675 loading of "firmware", which is encoded in the QE firmware binary format.
3676 This firmware often needs to be loaded during U-Boot booting, so macros
3677 are used to identify the storage device (NOR flash, SPI, etc) and the address
3678 within that device.
3680 - CONFIG_SYS_QE_FMAN_FW_ADDR
3681 The address in the storage device where the firmware is located. The
3682 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3683 is also specified.
3685 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3686 The maximum possible size of the firmware. The firmware binary format
3687 has a field that specifies the actual size of the firmware, but it
3688 might not be possible to read any part of the firmware unless some
3689 local storage is allocated to hold the entire firmware first.
3691 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3692 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3693 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3694 virtual address in NOR flash.
3696 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3697 Specifies that QE/FMAN firmware is located in NAND flash.
3698 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3700 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3701 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3702 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3704 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
3705 Specifies that QE/FMAN firmware is located on the primary SPI
3706 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3708 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3709 Specifies that QE/FMAN firmware is located in the remote (master)
3710 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3711 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3712 window->master inbound window->master LAW->the ucode address in
3713 master's memory space.
3715 Building the Software:
3716 ======================
3718 Building U-Boot has been tested in several native build environments
3719 and in many different cross environments. Of course we cannot support
3720 all possibly existing versions of cross development tools in all
3721 (potentially obsolete) versions. In case of tool chain problems we
3722 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3723 which is extensively used to build and test U-Boot.
3725 If you are not using a native environment, it is assumed that you
3726 have GNU cross compiling tools available in your path. In this case,
3727 you must set the environment variable CROSS_COMPILE in your shell.
3728 Note that no changes to the Makefile or any other source files are
3729 necessary. For example using the ELDK on a 4xx CPU, please enter:
3731 $ CROSS_COMPILE=ppc_4xx-
3732 $ export CROSS_COMPILE
3734 Note: If you wish to generate Windows versions of the utilities in
3735 the tools directory you can use the MinGW toolchain
3736 (http://www.mingw.org). Set your HOST tools to the MinGW
3737 toolchain and execute 'make tools'. For example:
3739 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3741 Binaries such as tools/mkimage.exe will be created which can
3742 be executed on computers running Windows.
3744 U-Boot is intended to be simple to build. After installing the
3745 sources you must configure U-Boot for one specific board type. This
3746 is done by typing:
3748 make NAME_config
3750 where "NAME_config" is the name of one of the existing configu-
3751 rations; see boards.cfg for supported names.
3753 Note: for some board special configuration names may exist; check if
3754 additional information is available from the board vendor; for
3755 instance, the TQM823L systems are available without (standard)
3756 or with LCD support. You can select such additional "features"
3757 when choosing the configuration, i. e.
3759 make TQM823L_config
3760 - will configure for a plain TQM823L, i. e. no LCD support
3762 make TQM823L_LCD_config
3763 - will configure for a TQM823L with U-Boot console on LCD
3765 etc.
3768 Finally, type "make all", and you should get some working U-Boot
3769 images ready for download to / installation on your system:
3771 - "u-boot.bin" is a raw binary image
3772 - "u-boot" is an image in ELF binary format
3773 - "u-boot.srec" is in Motorola S-Record format
3775 By default the build is performed locally and the objects are saved
3776 in the source directory. One of the two methods can be used to change
3777 this behavior and build U-Boot to some external directory:
3779 1. Add O= to the make command line invocations:
3781 make O=/tmp/build distclean
3782 make O=/tmp/build NAME_config
3783 make O=/tmp/build all
3785 2. Set environment variable BUILD_DIR to point to the desired location:
3787 export BUILD_DIR=/tmp/build
3788 make distclean
3789 make NAME_config
3790 make all
3792 Note that the command line "O=" setting overrides the BUILD_DIR environment
3793 variable.
3796 Please be aware that the Makefiles assume you are using GNU make, so
3797 for instance on NetBSD you might need to use "gmake" instead of
3798 native "make".
3801 If the system board that you have is not listed, then you will need
3802 to port U-Boot to your hardware platform. To do this, follow these
3803 steps:
3805 1. Add a new configuration option for your board to the toplevel
3806 "boards.cfg" file, using the existing entries as examples.
3807 Follow the instructions there to keep the boards in order.
3808 2. Create a new directory to hold your board specific code. Add any
3809 files you need. In your board directory, you will need at least
3810 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3811 3. Create a new configuration file "include/configs/<board>.h" for
3812 your board
3813 3. If you're porting U-Boot to a new CPU, then also create a new
3814 directory to hold your CPU specific code. Add any files you need.
3815 4. Run "make <board>_config" with your new name.
3816 5. Type "make", and you should get a working "u-boot.srec" file
3817 to be installed on your target system.
3818 6. Debug and solve any problems that might arise.
3819 [Of course, this last step is much harder than it sounds.]
3822 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3823 ==============================================================
3825 If you have modified U-Boot sources (for instance added a new board
3826 or support for new devices, a new CPU, etc.) you are expected to
3827 provide feedback to the other developers. The feedback normally takes
3828 the form of a "patch", i. e. a context diff against a certain (latest
3829 official or latest in the git repository) version of U-Boot sources.
3831 But before you submit such a patch, please verify that your modifi-
3832 cation did not break existing code. At least make sure that *ALL* of
3833 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3834 just run the "MAKEALL" script, which will configure and build U-Boot
3835 for ALL supported system. Be warned, this will take a while. You can
3836 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3837 environment variable to the script, i. e. to use the ELDK cross tools
3838 you can type
3840 CROSS_COMPILE=ppc_8xx- MAKEALL
3842 or to build on a native PowerPC system you can type
3844 CROSS_COMPILE=' ' MAKEALL
3846 When using the MAKEALL script, the default behaviour is to build
3847 U-Boot in the source directory. This location can be changed by
3848 setting the BUILD_DIR environment variable. Also, for each target
3849 built, the MAKEALL script saves two log files (<target>.ERR and
3850 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3851 location can be changed by setting the MAKEALL_LOGDIR environment
3852 variable. For example:
3854 export BUILD_DIR=/tmp/build
3855 export MAKEALL_LOGDIR=/tmp/log
3856 CROSS_COMPILE=ppc_8xx- MAKEALL
3858 With the above settings build objects are saved in the /tmp/build,
3859 log files are saved in the /tmp/log and the source tree remains clean
3860 during the whole build process.
3863 See also "U-Boot Porting Guide" below.
3866 Monitor Commands - Overview:
3867 ============================
3869 go - start application at address 'addr'
3870 run - run commands in an environment variable
3871 bootm - boot application image from memory
3872 bootp - boot image via network using BootP/TFTP protocol
3873 bootz - boot zImage from memory
3874 tftpboot- boot image via network using TFTP protocol
3875 and env variables "ipaddr" and "serverip"
3876 (and eventually "gatewayip")
3877 tftpput - upload a file via network using TFTP protocol
3878 rarpboot- boot image via network using RARP/TFTP protocol
3879 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3880 loads - load S-Record file over serial line
3881 loadb - load binary file over serial line (kermit mode)
3882 md - memory display
3883 mm - memory modify (auto-incrementing)
3884 nm - memory modify (constant address)
3885 mw - memory write (fill)
3886 cp - memory copy
3887 cmp - memory compare
3888 crc32 - checksum calculation
3889 i2c - I2C sub-system
3890 sspi - SPI utility commands
3891 base - print or set address offset
3892 printenv- print environment variables
3893 setenv - set environment variables
3894 saveenv - save environment variables to persistent storage
3895 protect - enable or disable FLASH write protection
3896 erase - erase FLASH memory
3897 flinfo - print FLASH memory information
3898 nand - NAND memory operations (see doc/README.nand)
3899 bdinfo - print Board Info structure
3900 iminfo - print header information for application image
3901 coninfo - print console devices and informations
3902 ide - IDE sub-system
3903 loop - infinite loop on address range
3904 loopw - infinite write loop on address range
3905 mtest - simple RAM test
3906 icache - enable or disable instruction cache
3907 dcache - enable or disable data cache
3908 reset - Perform RESET of the CPU
3909 echo - echo args to console
3910 version - print monitor version
3911 help - print online help
3912 ? - alias for 'help'
3915 Monitor Commands - Detailed Description:
3916 ========================================
3918 TODO.
3920 For now: just type "help <command>".
3923 Environment Variables:
3924 ======================
3926 U-Boot supports user configuration using Environment Variables which
3927 can be made persistent by saving to Flash memory.
3929 Environment Variables are set using "setenv", printed using
3930 "printenv", and saved to Flash using "saveenv". Using "setenv"
3931 without a value can be used to delete a variable from the
3932 environment. As long as you don't save the environment you are
3933 working with an in-memory copy. In case the Flash area containing the
3934 environment is erased by accident, a default environment is provided.
3936 Some configuration options can be set using Environment Variables.
3938 List of environment variables (most likely not complete):
3940 baudrate - see CONFIG_BAUDRATE
3942 bootdelay - see CONFIG_BOOTDELAY
3944 bootcmd - see CONFIG_BOOTCOMMAND
3946 bootargs - Boot arguments when booting an RTOS image
3948 bootfile - Name of the image to load with TFTP
3950 bootm_low - Memory range available for image processing in the bootm
3951 command can be restricted. This variable is given as
3952 a hexadecimal number and defines lowest address allowed
3953 for use by the bootm command. See also "bootm_size"
3954 environment variable. Address defined by "bootm_low" is
3955 also the base of the initial memory mapping for the Linux
3956 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3957 bootm_mapsize.
3959 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3960 This variable is given as a hexadecimal number and it
3961 defines the size of the memory region starting at base
3962 address bootm_low that is accessible by the Linux kernel
3963 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3964 as the default value if it is defined, and bootm_size is
3965 used otherwise.
3967 bootm_size - Memory range available for image processing in the bootm
3968 command can be restricted. This variable is given as
3969 a hexadecimal number and defines the size of the region
3970 allowed for use by the bootm command. See also "bootm_low"
3971 environment variable.
3973 updatefile - Location of the software update file on a TFTP server, used
3974 by the automatic software update feature. Please refer to
3975 documentation in doc/README.update for more details.
3977 autoload - if set to "no" (any string beginning with 'n'),
3978 "bootp" will just load perform a lookup of the
3979 configuration from the BOOTP server, but not try to
3980 load any image using TFTP
3982 autostart - if set to "yes", an image loaded using the "bootp",
3983 "rarpboot", "tftpboot" or "diskboot" commands will
3984 be automatically started (by internally calling
3985 "bootm")
3987 If set to "no", a standalone image passed to the
3988 "bootm" command will be copied to the load address
3989 (and eventually uncompressed), but NOT be started.
3990 This can be used to load and uncompress arbitrary
3991 data.
3993 fdt_high - if set this restricts the maximum address that the
3994 flattened device tree will be copied into upon boot.
3995 For example, if you have a system with 1 GB memory
3996 at physical address 0x10000000, while Linux kernel
3997 only recognizes the first 704 MB as low memory, you
3998 may need to set fdt_high as 0x3C000000 to have the
3999 device tree blob be copied to the maximum address
4000 of the 704 MB low memory, so that Linux kernel can
4001 access it during the boot procedure.
4003 If this is set to the special value 0xFFFFFFFF then
4004 the fdt will not be copied at all on boot. For this
4005 to work it must reside in writable memory, have
4006 sufficient padding on the end of it for u-boot to
4007 add the information it needs into it, and the memory
4008 must be accessible by the kernel.
4010 fdtcontroladdr- if set this is the address of the control flattened
4011 device tree used by U-Boot when CONFIG_OF_CONTROL is
4012 defined.
4014 i2cfast - (PPC405GP|PPC405EP only)
4015 if set to 'y' configures Linux I2C driver for fast
4016 mode (400kHZ). This environment variable is used in
4017 initialization code. So, for changes to be effective
4018 it must be saved and board must be reset.
4020 initrd_high - restrict positioning of initrd images:
4021 If this variable is not set, initrd images will be
4022 copied to the highest possible address in RAM; this
4023 is usually what you want since it allows for
4024 maximum initrd size. If for some reason you want to
4025 make sure that the initrd image is loaded below the
4026 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4027 variable to a value of "no" or "off" or "0".
4028 Alternatively, you can set it to a maximum upper
4029 address to use (U-Boot will still check that it
4030 does not overwrite the U-Boot stack and data).
4032 For instance, when you have a system with 16 MB
4033 RAM, and want to reserve 4 MB from use by Linux,
4034 you can do this by adding "mem=12M" to the value of
4035 the "bootargs" variable. However, now you must make
4036 sure that the initrd image is placed in the first
4037 12 MB as well - this can be done with
4039 setenv initrd_high 00c00000
4041 If you set initrd_high to 0xFFFFFFFF, this is an
4042 indication to U-Boot that all addresses are legal
4043 for the Linux kernel, including addresses in flash
4044 memory. In this case U-Boot will NOT COPY the
4045 ramdisk at all. This may be useful to reduce the
4046 boot time on your system, but requires that this
4047 feature is supported by your Linux kernel.
4049 ipaddr - IP address; needed for tftpboot command
4051 loadaddr - Default load address for commands like "bootp",
4052 "rarpboot", "tftpboot", "loadb" or "diskboot"
4054 loads_echo - see CONFIG_LOADS_ECHO
4056 serverip - TFTP server IP address; needed for tftpboot command
4058 bootretry - see CONFIG_BOOT_RETRY_TIME
4060 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4062 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4064 ethprime - controls which interface is used first.
4066 ethact - controls which interface is currently active.
4067 For example you can do the following
4069 => setenv ethact FEC
4070 => ping 192.168.0.1 # traffic sent on FEC
4071 => setenv ethact SCC
4072 => ping 10.0.0.1 # traffic sent on SCC
4074 ethrotate - When set to "no" U-Boot does not go through all
4075 available network interfaces.
4076 It just stays at the currently selected interface.
4078 netretry - When set to "no" each network operation will
4079 either succeed or fail without retrying.
4080 When set to "once" the network operation will
4081 fail when all the available network interfaces
4082 are tried once without success.
4083 Useful on scripts which control the retry operation
4084 themselves.
4086 npe_ucode - set load address for the NPE microcode
4088 tftpsrcport - If this is set, the value is used for TFTP's
4089 UDP source port.
4091 tftpdstport - If this is set, the value is used for TFTP's UDP
4092 destination port instead of the Well Know Port 69.
4094 tftpblocksize - Block size to use for TFTP transfers; if not set,
4095 we use the TFTP server's default block size
4097 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4098 seconds, minimum value is 1000 = 1 second). Defines
4099 when a packet is considered to be lost so it has to
4100 be retransmitted. The default is 5000 = 5 seconds.
4101 Lowering this value may make downloads succeed
4102 faster in networks with high packet loss rates or
4103 with unreliable TFTP servers.
4105 vlan - When set to a value < 4095 the traffic over
4106 Ethernet is encapsulated/received over 802.1q
4107 VLAN tagged frames.
4109 The following image location variables contain the location of images
4110 used in booting. The "Image" column gives the role of the image and is
4111 not an environment variable name. The other columns are environment
4112 variable names. "File Name" gives the name of the file on a TFTP
4113 server, "RAM Address" gives the location in RAM the image will be
4114 loaded to, and "Flash Location" gives the image's address in NOR
4115 flash or offset in NAND flash.
4117 *Note* - these variables don't have to be defined for all boards, some
4118 boards currenlty use other variables for these purposes, and some
4119 boards use these variables for other purposes.
4121 Image File Name RAM Address Flash Location
4122 ----- --------- ----------- --------------
4123 u-boot u-boot u-boot_addr_r u-boot_addr
4124 Linux kernel bootfile kernel_addr_r kernel_addr
4125 device tree blob fdtfile fdt_addr_r fdt_addr
4126 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4128 The following environment variables may be used and automatically
4129 updated by the network boot commands ("bootp" and "rarpboot"),
4130 depending the information provided by your boot server:
4132 bootfile - see above
4133 dnsip - IP address of your Domain Name Server
4134 dnsip2 - IP address of your secondary Domain Name Server
4135 gatewayip - IP address of the Gateway (Router) to use
4136 hostname - Target hostname
4137 ipaddr - see above
4138 netmask - Subnet Mask
4139 rootpath - Pathname of the root filesystem on the NFS server
4140 serverip - see above
4143 There are two special Environment Variables:
4145 serial# - contains hardware identification information such
4146 as type string and/or serial number
4147 ethaddr - Ethernet address
4149 These variables can be set only once (usually during manufacturing of
4150 the board). U-Boot refuses to delete or overwrite these variables
4151 once they have been set once.
4154 Further special Environment Variables:
4156 ver - Contains the U-Boot version string as printed
4157 with the "version" command. This variable is
4158 readonly (see CONFIG_VERSION_VARIABLE).
4161 Please note that changes to some configuration parameters may take
4162 only effect after the next boot (yes, that's just like Windoze :-).
4165 Command Line Parsing:
4166 =====================
4168 There are two different command line parsers available with U-Boot:
4169 the old "simple" one, and the much more powerful "hush" shell:
4171 Old, simple command line parser:
4172 --------------------------------
4174 - supports environment variables (through setenv / saveenv commands)
4175 - several commands on one line, separated by ';'
4176 - variable substitution using "... ${name} ..." syntax
4177 - special characters ('$', ';') can be escaped by prefixing with '\',
4178 for example:
4179 setenv bootcmd bootm \${address}
4180 - You can also escape text by enclosing in single apostrophes, for example:
4181 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
4183 Hush shell:
4184 -----------
4186 - similar to Bourne shell, with control structures like
4187 if...then...else...fi, for...do...done; while...do...done,
4188 until...do...done, ...
4189 - supports environment ("global") variables (through setenv / saveenv
4190 commands) and local shell variables (through standard shell syntax
4191 "name=value"); only environment variables can be used with "run"
4192 command
4194 General rules:
4195 --------------
4197 (1) If a command line (or an environment variable executed by a "run"
4198 command) contains several commands separated by semicolon, and
4199 one of these commands fails, then the remaining commands will be
4200 executed anyway.
4202 (2) If you execute several variables with one call to run (i. e.
4203 calling run with a list of variables as arguments), any failing
4204 command will cause "run" to terminate, i. e. the remaining
4205 variables are not executed.
4207 Note for Redundant Ethernet Interfaces:
4208 =======================================
4210 Some boards come with redundant Ethernet interfaces; U-Boot supports
4211 such configurations and is capable of automatic selection of a
4212 "working" interface when needed. MAC assignment works as follows:
4214 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4215 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4216 "eth1addr" (=>eth1), "eth2addr", ...
4218 If the network interface stores some valid MAC address (for instance
4219 in SROM), this is used as default address if there is NO correspon-
4220 ding setting in the environment; if the corresponding environment
4221 variable is set, this overrides the settings in the card; that means:
4223 o If the SROM has a valid MAC address, and there is no address in the
4224 environment, the SROM's address is used.
4226 o If there is no valid address in the SROM, and a definition in the
4227 environment exists, then the value from the environment variable is
4228 used.
4230 o If both the SROM and the environment contain a MAC address, and
4231 both addresses are the same, this MAC address is used.
4233 o If both the SROM and the environment contain a MAC address, and the
4234 addresses differ, the value from the environment is used and a
4235 warning is printed.
4237 o If neither SROM nor the environment contain a MAC address, an error
4238 is raised.
4240 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4241 will be programmed into hardware as part of the initialization process. This
4242 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4243 The naming convention is as follows:
4244 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4246 Image Formats:
4247 ==============
4249 U-Boot is capable of booting (and performing other auxiliary operations on)
4250 images in two formats:
4252 New uImage format (FIT)
4253 -----------------------
4255 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4256 to Flattened Device Tree). It allows the use of images with multiple
4257 components (several kernels, ramdisks, etc.), with contents protected by
4258 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4261 Old uImage format
4262 -----------------
4264 Old image format is based on binary files which can be basically anything,
4265 preceded by a special header; see the definitions in include/image.h for
4266 details; basically, the header defines the following image properties:
4268 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4269 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4270 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4271 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4272 INTEGRITY).
4273 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
4274 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4275 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4276 * Compression Type (uncompressed, gzip, bzip2)
4277 * Load Address
4278 * Entry Point
4279 * Image Name
4280 * Image Timestamp
4282 The header is marked by a special Magic Number, and both the header
4283 and the data portions of the image are secured against corruption by
4284 CRC32 checksums.
4287 Linux Support:
4288 ==============
4290 Although U-Boot should support any OS or standalone application
4291 easily, the main focus has always been on Linux during the design of
4292 U-Boot.
4294 U-Boot includes many features that so far have been part of some
4295 special "boot loader" code within the Linux kernel. Also, any
4296 "initrd" images to be used are no longer part of one big Linux image;
4297 instead, kernel and "initrd" are separate images. This implementation
4298 serves several purposes:
4300 - the same features can be used for other OS or standalone
4301 applications (for instance: using compressed images to reduce the
4302 Flash memory footprint)
4304 - it becomes much easier to port new Linux kernel versions because
4305 lots of low-level, hardware dependent stuff are done by U-Boot
4307 - the same Linux kernel image can now be used with different "initrd"
4308 images; of course this also means that different kernel images can
4309 be run with the same "initrd". This makes testing easier (you don't
4310 have to build a new "zImage.initrd" Linux image when you just
4311 change a file in your "initrd"). Also, a field-upgrade of the
4312 software is easier now.
4315 Linux HOWTO:
4316 ============
4318 Porting Linux to U-Boot based systems:
4319 ---------------------------------------
4321 U-Boot cannot save you from doing all the necessary modifications to
4322 configure the Linux device drivers for use with your target hardware
4323 (no, we don't intend to provide a full virtual machine interface to
4324 Linux :-).
4326 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4328 Just make sure your machine specific header file (for instance
4329 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4330 Information structure as we define in include/asm-<arch>/u-boot.h,
4331 and make sure that your definition of IMAP_ADDR uses the same value
4332 as your U-Boot configuration in CONFIG_SYS_IMMR.
4335 Configuring the Linux kernel:
4336 -----------------------------
4338 No specific requirements for U-Boot. Make sure you have some root
4339 device (initial ramdisk, NFS) for your target system.
4342 Building a Linux Image:
4343 -----------------------
4345 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4346 not used. If you use recent kernel source, a new build target
4347 "uImage" will exist which automatically builds an image usable by
4348 U-Boot. Most older kernels also have support for a "pImage" target,
4349 which was introduced for our predecessor project PPCBoot and uses a
4350 100% compatible format.
4352 Example:
4354 make TQM850L_config
4355 make oldconfig
4356 make dep
4357 make uImage
4359 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4360 encapsulate a compressed Linux kernel image with header information,
4361 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4363 * build a standard "vmlinux" kernel image (in ELF binary format):
4365 * convert the kernel into a raw binary image:
4367 ${CROSS_COMPILE}-objcopy -O binary \
4368 -R .note -R .comment \
4369 -S vmlinux linux.bin
4371 * compress the binary image:
4373 gzip -9 linux.bin
4375 * package compressed binary image for U-Boot:
4377 mkimage -A ppc -O linux -T kernel -C gzip \
4378 -a 0 -e 0 -n "Linux Kernel Image" \
4379 -d linux.bin.gz uImage
4382 The "mkimage" tool can also be used to create ramdisk images for use
4383 with U-Boot, either separated from the Linux kernel image, or
4384 combined into one file. "mkimage" encapsulates the images with a 64
4385 byte header containing information about target architecture,
4386 operating system, image type, compression method, entry points, time
4387 stamp, CRC32 checksums, etc.
4389 "mkimage" can be called in two ways: to verify existing images and
4390 print the header information, or to build new images.
4392 In the first form (with "-l" option) mkimage lists the information
4393 contained in the header of an existing U-Boot image; this includes
4394 checksum verification:
4396 tools/mkimage -l image
4397 -l ==> list image header information
4399 The second form (with "-d" option) is used to build a U-Boot image
4400 from a "data file" which is used as image payload:
4402 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4403 -n name -d data_file image
4404 -A ==> set architecture to 'arch'
4405 -O ==> set operating system to 'os'
4406 -T ==> set image type to 'type'
4407 -C ==> set compression type 'comp'
4408 -a ==> set load address to 'addr' (hex)
4409 -e ==> set entry point to 'ep' (hex)
4410 -n ==> set image name to 'name'
4411 -d ==> use image data from 'datafile'
4413 Right now, all Linux kernels for PowerPC systems use the same load
4414 address (0x00000000), but the entry point address depends on the
4415 kernel version:
4417 - 2.2.x kernels have the entry point at 0x0000000C,
4418 - 2.3.x and later kernels have the entry point at 0x00000000.
4420 So a typical call to build a U-Boot image would read:
4422 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4423 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4424 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4425 > examples/uImage.TQM850L
4426 Image Name: 2.4.4 kernel for TQM850L
4427 Created: Wed Jul 19 02:34:59 2000
4428 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4429 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4430 Load Address: 0x00000000
4431 Entry Point: 0x00000000
4433 To verify the contents of the image (or check for corruption):
4435 -> tools/mkimage -l examples/uImage.TQM850L
4436 Image Name: 2.4.4 kernel for TQM850L
4437 Created: Wed Jul 19 02:34:59 2000
4438 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4439 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4440 Load Address: 0x00000000
4441 Entry Point: 0x00000000
4443 NOTE: for embedded systems where boot time is critical you can trade
4444 speed for memory and install an UNCOMPRESSED image instead: this
4445 needs more space in Flash, but boots much faster since it does not
4446 need to be uncompressed:
4448 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4449 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4450 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4451 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4452 > examples/uImage.TQM850L-uncompressed
4453 Image Name: 2.4.4 kernel for TQM850L
4454 Created: Wed Jul 19 02:34:59 2000
4455 Image Type: PowerPC Linux Kernel Image (uncompressed)
4456 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4457 Load Address: 0x00000000
4458 Entry Point: 0x00000000
4461 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4462 when your kernel is intended to use an initial ramdisk:
4464 -> tools/mkimage -n 'Simple Ramdisk Image' \
4465 > -A ppc -O linux -T ramdisk -C gzip \
4466 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4467 Image Name: Simple Ramdisk Image
4468 Created: Wed Jan 12 14:01:50 2000
4469 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4470 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4471 Load Address: 0x00000000
4472 Entry Point: 0x00000000
4475 Installing a Linux Image:
4476 -------------------------
4478 To downloading a U-Boot image over the serial (console) interface,
4479 you must convert the image to S-Record format:
4481 objcopy -I binary -O srec examples/image examples/image.srec
4483 The 'objcopy' does not understand the information in the U-Boot
4484 image header, so the resulting S-Record file will be relative to
4485 address 0x00000000. To load it to a given address, you need to
4486 specify the target address as 'offset' parameter with the 'loads'
4487 command.
4489 Example: install the image to address 0x40100000 (which on the
4490 TQM8xxL is in the first Flash bank):
4492 => erase 40100000 401FFFFF
4494 .......... done
4495 Erased 8 sectors
4497 => loads 40100000
4498 ## Ready for S-Record download ...
4499 ~>examples/image.srec
4500 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4501 ...
4502 15989 15990 15991 15992
4503 [file transfer complete]
4504 [connected]
4505 ## Start Addr = 0x00000000
4508 You can check the success of the download using the 'iminfo' command;
4509 this includes a checksum verification so you can be sure no data
4510 corruption happened:
4512 => imi 40100000
4514 ## Checking Image at 40100000 ...
4515 Image Name: 2.2.13 for initrd on TQM850L
4516 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4517 Data Size: 335725 Bytes = 327 kB = 0 MB
4518 Load Address: 00000000
4519 Entry Point: 0000000c
4520 Verifying Checksum ... OK
4523 Boot Linux:
4524 -----------
4526 The "bootm" command is used to boot an application that is stored in
4527 memory (RAM or Flash). In case of a Linux kernel image, the contents
4528 of the "bootargs" environment variable is passed to the kernel as
4529 parameters. You can check and modify this variable using the
4530 "printenv" and "setenv" commands:
4533 => printenv bootargs
4534 bootargs=root=/dev/ram
4536 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4538 => printenv bootargs
4539 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4541 => bootm 40020000
4542 ## Booting Linux kernel at 40020000 ...
4543 Image Name: 2.2.13 for NFS on TQM850L
4544 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4545 Data Size: 381681 Bytes = 372 kB = 0 MB
4546 Load Address: 00000000
4547 Entry Point: 0000000c
4548 Verifying Checksum ... OK
4549 Uncompressing Kernel Image ... OK
4550 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
4551 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4552 time_init: decrementer frequency = 187500000/60
4553 Calibrating delay loop... 49.77 BogoMIPS
4554 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4555 ...
4557 If you want to boot a Linux kernel with initial RAM disk, you pass
4558 the memory addresses of both the kernel and the initrd image (PPBCOOT
4559 format!) to the "bootm" command:
4561 => imi 40100000 40200000
4563 ## Checking Image at 40100000 ...
4564 Image Name: 2.2.13 for initrd on TQM850L
4565 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4566 Data Size: 335725 Bytes = 327 kB = 0 MB
4567 Load Address: 00000000
4568 Entry Point: 0000000c
4569 Verifying Checksum ... OK
4571 ## Checking Image at 40200000 ...
4572 Image Name: Simple Ramdisk Image
4573 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4574 Data Size: 566530 Bytes = 553 kB = 0 MB
4575 Load Address: 00000000
4576 Entry Point: 00000000
4577 Verifying Checksum ... OK
4579 => bootm 40100000 40200000
4580 ## Booting Linux kernel at 40100000 ...
4581 Image Name: 2.2.13 for initrd on TQM850L
4582 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4583 Data Size: 335725 Bytes = 327 kB = 0 MB
4584 Load Address: 00000000
4585 Entry Point: 0000000c
4586 Verifying Checksum ... OK
4587 Uncompressing Kernel Image ... OK
4588 ## Loading RAMDisk Image at 40200000 ...
4589 Image Name: Simple Ramdisk Image
4590 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4591 Data Size: 566530 Bytes = 553 kB = 0 MB
4592 Load Address: 00000000
4593 Entry Point: 00000000
4594 Verifying Checksum ... OK
4595 Loading Ramdisk ... OK
4596 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
4597 Boot arguments: root=/dev/ram
4598 time_init: decrementer frequency = 187500000/60
4599 Calibrating delay loop... 49.77 BogoMIPS
4600 ...
4601 RAMDISK: Compressed image found at block 0
4602 VFS: Mounted root (ext2 filesystem).
4604 bash#
4606 Boot Linux and pass a flat device tree:
4607 -----------
4609 First, U-Boot must be compiled with the appropriate defines. See the section
4610 titled "Linux Kernel Interface" above for a more in depth explanation. The
4611 following is an example of how to start a kernel and pass an updated
4612 flat device tree:
4614 => print oftaddr
4615 oftaddr=0x300000
4616 => print oft
4617 oft=oftrees/mpc8540ads.dtb
4618 => tftp $oftaddr $oft
4619 Speed: 1000, full duplex
4620 Using TSEC0 device
4621 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4622 Filename 'oftrees/mpc8540ads.dtb'.
4623 Load address: 0x300000
4624 Loading: #
4625 done
4626 Bytes transferred = 4106 (100a hex)
4627 => tftp $loadaddr $bootfile
4628 Speed: 1000, full duplex
4629 Using TSEC0 device
4630 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4631 Filename 'uImage'.
4632 Load address: 0x200000
4633 Loading:############
4634 done
4635 Bytes transferred = 1029407 (fb51f hex)
4636 => print loadaddr
4637 loadaddr=200000
4638 => print oftaddr
4639 oftaddr=0x300000
4640 => bootm $loadaddr - $oftaddr
4641 ## Booting image at 00200000 ...
4642 Image Name: Linux-2.6.17-dirty
4643 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4644 Data Size: 1029343 Bytes = 1005.2 kB
4645 Load Address: 00000000
4646 Entry Point: 00000000
4647 Verifying Checksum ... OK
4648 Uncompressing Kernel Image ... OK
4649 Booting using flat device tree at 0x300000
4650 Using MPC85xx ADS machine description
4651 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4652 [snip]
4655 More About U-Boot Image Types:
4656 ------------------------------
4658 U-Boot supports the following image types:
4660 "Standalone Programs" are directly runnable in the environment
4661 provided by U-Boot; it is expected that (if they behave
4662 well) you can continue to work in U-Boot after return from
4663 the Standalone Program.
4664 "OS Kernel Images" are usually images of some Embedded OS which
4665 will take over control completely. Usually these programs
4666 will install their own set of exception handlers, device
4667 drivers, set up the MMU, etc. - this means, that you cannot
4668 expect to re-enter U-Boot except by resetting the CPU.
4669 "RAMDisk Images" are more or less just data blocks, and their
4670 parameters (address, size) are passed to an OS kernel that is
4671 being started.
4672 "Multi-File Images" contain several images, typically an OS
4673 (Linux) kernel image and one or more data images like
4674 RAMDisks. This construct is useful for instance when you want
4675 to boot over the network using BOOTP etc., where the boot
4676 server provides just a single image file, but you want to get
4677 for instance an OS kernel and a RAMDisk image.
4679 "Multi-File Images" start with a list of image sizes, each
4680 image size (in bytes) specified by an "uint32_t" in network
4681 byte order. This list is terminated by an "(uint32_t)0".
4682 Immediately after the terminating 0 follow the images, one by
4683 one, all aligned on "uint32_t" boundaries (size rounded up to
4684 a multiple of 4 bytes).
4686 "Firmware Images" are binary images containing firmware (like
4687 U-Boot or FPGA images) which usually will be programmed to
4688 flash memory.
4690 "Script files" are command sequences that will be executed by
4691 U-Boot's command interpreter; this feature is especially
4692 useful when you configure U-Boot to use a real shell (hush)
4693 as command interpreter.
4695 Booting the Linux zImage:
4696 -------------------------
4698 On some platforms, it's possible to boot Linux zImage. This is done
4699 using the "bootz" command. The syntax of "bootz" command is the same
4700 as the syntax of "bootm" command.
4702 Note, defining the CONFIG_SUPPORT_INITRD_RAW allows user to supply
4703 kernel with raw initrd images. The syntax is slightly different, the
4704 address of the initrd must be augmented by it's size, in the following
4705 format: "<initrd addres>:<initrd size>".
4708 Standalone HOWTO:
4709 =================
4711 One of the features of U-Boot is that you can dynamically load and
4712 run "standalone" applications, which can use some resources of
4713 U-Boot like console I/O functions or interrupt services.
4715 Two simple examples are included with the sources:
4717 "Hello World" Demo:
4718 -------------------
4720 'examples/hello_world.c' contains a small "Hello World" Demo
4721 application; it is automatically compiled when you build U-Boot.
4722 It's configured to run at address 0x00040004, so you can play with it
4723 like that:
4725 => loads
4726 ## Ready for S-Record download ...
4727 ~>examples/hello_world.srec
4728 1 2 3 4 5 6 7 8 9 10 11 ...
4729 [file transfer complete]
4730 [connected]
4731 ## Start Addr = 0x00040004
4733 => go 40004 Hello World! This is a test.
4734 ## Starting application at 0x00040004 ...
4735 Hello World
4736 argc = 7
4737 argv[0] = "40004"
4738 argv[1] = "Hello"
4739 argv[2] = "World!"
4740 argv[3] = "This"
4741 argv[4] = "is"
4742 argv[5] = "a"
4743 argv[6] = "test."
4744 argv[7] = "<NULL>"
4745 Hit any key to exit ...
4747 ## Application terminated, rc = 0x0
4749 Another example, which demonstrates how to register a CPM interrupt
4750 handler with the U-Boot code, can be found in 'examples/timer.c'.
4751 Here, a CPM timer is set up to generate an interrupt every second.
4752 The interrupt service routine is trivial, just printing a '.'
4753 character, but this is just a demo program. The application can be
4754 controlled by the following keys:
4756 ? - print current values og the CPM Timer registers
4757 b - enable interrupts and start timer
4758 e - stop timer and disable interrupts
4759 q - quit application
4761 => loads
4762 ## Ready for S-Record download ...
4763 ~>examples/timer.srec
4764 1 2 3 4 5 6 7 8 9 10 11 ...
4765 [file transfer complete]
4766 [connected]
4767 ## Start Addr = 0x00040004
4769 => go 40004
4770 ## Starting application at 0x00040004 ...
4771 TIMERS=0xfff00980
4772 Using timer 1
4773 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4775 Hit 'b':
4776 [q, b, e, ?] Set interval 1000000 us
4777 Enabling timer
4778 Hit '?':
4779 [q, b, e, ?] ........
4780 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4781 Hit '?':
4782 [q, b, e, ?] .
4783 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4784 Hit '?':
4785 [q, b, e, ?] .
4786 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4787 Hit '?':
4788 [q, b, e, ?] .
4789 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4790 Hit 'e':
4791 [q, b, e, ?] ...Stopping timer
4792 Hit 'q':
4793 [q, b, e, ?] ## Application terminated, rc = 0x0
4796 Minicom warning:
4797 ================
4799 Over time, many people have reported problems when trying to use the
4800 "minicom" terminal emulation program for serial download. I (wd)
4801 consider minicom to be broken, and recommend not to use it. Under
4802 Unix, I recommend to use C-Kermit for general purpose use (and
4803 especially for kermit binary protocol download ("loadb" command), and
4804 use "cu" for S-Record download ("loads" command). See
4805 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4806 for help with kermit.
4809 Nevertheless, if you absolutely want to use it try adding this
4810 configuration to your "File transfer protocols" section:
4812 Name Program Name U/D FullScr IO-Red. Multi
4813 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4814 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4817 NetBSD Notes:
4818 =============
4820 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4821 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4823 Building requires a cross environment; it is known to work on
4824 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4825 need gmake since the Makefiles are not compatible with BSD make).
4826 Note that the cross-powerpc package does not install include files;
4827 attempting to build U-Boot will fail because <machine/ansi.h> is
4828 missing. This file has to be installed and patched manually:
4830 # cd /usr/pkg/cross/powerpc-netbsd/include
4831 # mkdir powerpc
4832 # ln -s powerpc machine
4833 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4834 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4836 Native builds *don't* work due to incompatibilities between native
4837 and U-Boot include files.
4839 Booting assumes that (the first part of) the image booted is a
4840 stage-2 loader which in turn loads and then invokes the kernel
4841 proper. Loader sources will eventually appear in the NetBSD source
4842 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4843 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4846 Implementation Internals:
4847 =========================
4849 The following is not intended to be a complete description of every
4850 implementation detail. However, it should help to understand the
4851 inner workings of U-Boot and make it easier to port it to custom
4852 hardware.
4855 Initial Stack, Global Data:
4856 ---------------------------
4858 The implementation of U-Boot is complicated by the fact that U-Boot
4859 starts running out of ROM (flash memory), usually without access to
4860 system RAM (because the memory controller is not initialized yet).
4861 This means that we don't have writable Data or BSS segments, and BSS
4862 is not initialized as zero. To be able to get a C environment working
4863 at all, we have to allocate at least a minimal stack. Implementation
4864 options for this are defined and restricted by the CPU used: Some CPU
4865 models provide on-chip memory (like the IMMR area on MPC8xx and
4866 MPC826x processors), on others (parts of) the data cache can be
4867 locked as (mis-) used as memory, etc.
4869 Chris Hallinan posted a good summary of these issues to the
4870 U-Boot mailing list:
4872 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4873 From: "Chris Hallinan" <clh@net1plus.com>
4874 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4875 ...
4877 Correct me if I'm wrong, folks, but the way I understand it
4878 is this: Using DCACHE as initial RAM for Stack, etc, does not
4879 require any physical RAM backing up the cache. The cleverness
4880 is that the cache is being used as a temporary supply of
4881 necessary storage before the SDRAM controller is setup. It's
4882 beyond the scope of this list to explain the details, but you
4883 can see how this works by studying the cache architecture and
4884 operation in the architecture and processor-specific manuals.
4886 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4887 is another option for the system designer to use as an
4888 initial stack/RAM area prior to SDRAM being available. Either
4889 option should work for you. Using CS 4 should be fine if your
4890 board designers haven't used it for something that would
4891 cause you grief during the initial boot! It is frequently not
4892 used.
4894 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4895 with your processor/board/system design. The default value
4896 you will find in any recent u-boot distribution in
4897 walnut.h should work for you. I'd set it to a value larger
4898 than your SDRAM module. If you have a 64MB SDRAM module, set
4899 it above 400_0000. Just make sure your board has no resources
4900 that are supposed to respond to that address! That code in
4901 start.S has been around a while and should work as is when
4902 you get the config right.
4904 -Chris Hallinan
4905 DS4.COM, Inc.
4907 It is essential to remember this, since it has some impact on the C
4908 code for the initialization procedures:
4910 * Initialized global data (data segment) is read-only. Do not attempt
4911 to write it.
4913 * Do not use any uninitialized global data (or implicitely initialized
4914 as zero data - BSS segment) at all - this is undefined, initiali-
4915 zation is performed later (when relocating to RAM).
4917 * Stack space is very limited. Avoid big data buffers or things like
4918 that.
4920 Having only the stack as writable memory limits means we cannot use
4921 normal global data to share information beween the code. But it
4922 turned out that the implementation of U-Boot can be greatly
4923 simplified by making a global data structure (gd_t) available to all
4924 functions. We could pass a pointer to this data as argument to _all_
4925 functions, but this would bloat the code. Instead we use a feature of
4926 the GCC compiler (Global Register Variables) to share the data: we
4927 place a pointer (gd) to the global data into a register which we
4928 reserve for this purpose.
4930 When choosing a register for such a purpose we are restricted by the
4931 relevant (E)ABI specifications for the current architecture, and by
4932 GCC's implementation.
4934 For PowerPC, the following registers have specific use:
4935 R1: stack pointer
4936 R2: reserved for system use
4937 R3-R4: parameter passing and return values
4938 R5-R10: parameter passing
4939 R13: small data area pointer
4940 R30: GOT pointer
4941 R31: frame pointer
4943 (U-Boot also uses R12 as internal GOT pointer. r12
4944 is a volatile register so r12 needs to be reset when
4945 going back and forth between asm and C)
4947 ==> U-Boot will use R2 to hold a pointer to the global data
4949 Note: on PPC, we could use a static initializer (since the
4950 address of the global data structure is known at compile time),
4951 but it turned out that reserving a register results in somewhat
4952 smaller code - although the code savings are not that big (on
4953 average for all boards 752 bytes for the whole U-Boot image,
4954 624 text + 127 data).
4956 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4957 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4959 ==> U-Boot will use P3 to hold a pointer to the global data
4961 On ARM, the following registers are used:
4963 R0: function argument word/integer result
4964 R1-R3: function argument word
4965 R9: GOT pointer
4966 R10: stack limit (used only if stack checking if enabled)
4967 R11: argument (frame) pointer
4968 R12: temporary workspace
4969 R13: stack pointer
4970 R14: link register
4971 R15: program counter
4973 ==> U-Boot will use R8 to hold a pointer to the global data
4975 On Nios II, the ABI is documented here:
4976 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4978 ==> U-Boot will use gp to hold a pointer to the global data
4980 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4981 to access small data sections, so gp is free.
4983 On NDS32, the following registers are used:
4985 R0-R1: argument/return
4986 R2-R5: argument
4987 R15: temporary register for assembler
4988 R16: trampoline register
4989 R28: frame pointer (FP)
4990 R29: global pointer (GP)
4991 R30: link register (LP)
4992 R31: stack pointer (SP)
4993 PC: program counter (PC)
4995 ==> U-Boot will use R10 to hold a pointer to the global data
4997 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4998 or current versions of GCC may "optimize" the code too much.
5000 Memory Management:
5001 ------------------
5003 U-Boot runs in system state and uses physical addresses, i.e. the
5004 MMU is not used either for address mapping nor for memory protection.
5006 The available memory is mapped to fixed addresses using the memory
5007 controller. In this process, a contiguous block is formed for each
5008 memory type (Flash, SDRAM, SRAM), even when it consists of several
5009 physical memory banks.
5011 U-Boot is installed in the first 128 kB of the first Flash bank (on
5012 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5013 booting and sizing and initializing DRAM, the code relocates itself
5014 to the upper end of DRAM. Immediately below the U-Boot code some
5015 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5016 configuration setting]. Below that, a structure with global Board
5017 Info data is placed, followed by the stack (growing downward).
5019 Additionally, some exception handler code is copied to the low 8 kB
5020 of DRAM (0x00000000 ... 0x00001FFF).
5022 So a typical memory configuration with 16 MB of DRAM could look like
5023 this:
5025 0x0000 0000 Exception Vector code
5026 :
5027 0x0000 1FFF
5028 0x0000 2000 Free for Application Use
5029 :
5030 :
5032 :
5033 :
5034 0x00FB FF20 Monitor Stack (Growing downward)
5035 0x00FB FFAC Board Info Data and permanent copy of global data
5036 0x00FC 0000 Malloc Arena
5037 :
5038 0x00FD FFFF
5039 0x00FE 0000 RAM Copy of Monitor Code
5040 ... eventually: LCD or video framebuffer
5041 ... eventually: pRAM (Protected RAM - unchanged by reset)
5042 0x00FF FFFF [End of RAM]
5045 System Initialization:
5046 ----------------------
5048 In the reset configuration, U-Boot starts at the reset entry point
5049 (on most PowerPC systems at address 0x00000100). Because of the reset
5050 configuration for CS0# this is a mirror of the onboard Flash memory.
5051 To be able to re-map memory U-Boot then jumps to its link address.
5052 To be able to implement the initialization code in C, a (small!)
5053 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5054 which provide such a feature like MPC8xx or MPC8260), or in a locked
5055 part of the data cache. After that, U-Boot initializes the CPU core,
5056 the caches and the SIU.
5058 Next, all (potentially) available memory banks are mapped using a
5059 preliminary mapping. For example, we put them on 512 MB boundaries
5060 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5061 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5062 programmed for SDRAM access. Using the temporary configuration, a
5063 simple memory test is run that determines the size of the SDRAM
5064 banks.
5066 When there is more than one SDRAM bank, and the banks are of
5067 different size, the largest is mapped first. For equal size, the first
5068 bank (CS2#) is mapped first. The first mapping is always for address
5069 0x00000000, with any additional banks following immediately to create
5070 contiguous memory starting from 0.
5072 Then, the monitor installs itself at the upper end of the SDRAM area
5073 and allocates memory for use by malloc() and for the global Board
5074 Info data; also, the exception vector code is copied to the low RAM
5075 pages, and the final stack is set up.
5077 Only after this relocation will you have a "normal" C environment;
5078 until that you are restricted in several ways, mostly because you are
5079 running from ROM, and because the code will have to be relocated to a
5080 new address in RAM.
5083 U-Boot Porting Guide:
5084 ----------------------
5086 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5087 list, October 2002]
5090 int main(int argc, char *argv[])
5091 {
5092 sighandler_t no_more_time;
5094 signal(SIGALRM, no_more_time);
5095 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5097 if (available_money > available_manpower) {
5098 Pay consultant to port U-Boot;
5099 return 0;
5100 }
5102 Download latest U-Boot source;
5104 Subscribe to u-boot mailing list;
5106 if (clueless)
5107 email("Hi, I am new to U-Boot, how do I get started?");
5109 while (learning) {
5110 Read the README file in the top level directory;
5111 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5112 Read applicable doc/*.README;
5113 Read the source, Luke;
5114 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5115 }
5117 if (available_money > toLocalCurrency ($2500))
5118 Buy a BDI3000;
5119 else
5120 Add a lot of aggravation and time;
5122 if (a similar board exists) { /* hopefully... */
5123 cp -a board/<similar> board/<myboard>
5124 cp include/configs/<similar>.h include/configs/<myboard>.h
5125 } else {
5126 Create your own board support subdirectory;
5127 Create your own board include/configs/<myboard>.h file;
5128 }
5129 Edit new board/<myboard> files
5130 Edit new include/configs/<myboard>.h
5132 while (!accepted) {
5133 while (!running) {
5134 do {
5135 Add / modify source code;
5136 } until (compiles);
5137 Debug;
5138 if (clueless)
5139 email("Hi, I am having problems...");
5140 }
5141 Send patch file to the U-Boot email list;
5142 if (reasonable critiques)
5143 Incorporate improvements from email list code review;
5144 else
5145 Defend code as written;
5146 }
5148 return 0;
5149 }
5151 void no_more_time (int sig)
5152 {
5153 hire_a_guru();
5154 }
5157 Coding Standards:
5158 -----------------
5160 All contributions to U-Boot should conform to the Linux kernel
5161 coding style; see the file "Documentation/CodingStyle" and the script
5162 "scripts/Lindent" in your Linux kernel source directory.
5164 Source files originating from a different project (for example the
5165 MTD subsystem) are generally exempt from these guidelines and are not
5166 reformated to ease subsequent migration to newer versions of those
5167 sources.
5169 Please note that U-Boot is implemented in C (and to some small parts in
5170 Assembler); no C++ is used, so please do not use C++ style comments (//)
5171 in your code.
5173 Please also stick to the following formatting rules:
5174 - remove any trailing white space
5175 - use TAB characters for indentation and vertical alignment, not spaces
5176 - make sure NOT to use DOS '\r\n' line feeds
5177 - do not add more than 2 consecutive empty lines to source files
5178 - do not add trailing empty lines to source files
5180 Submissions which do not conform to the standards may be returned
5181 with a request to reformat the changes.
5184 Submitting Patches:
5185 -------------------
5187 Since the number of patches for U-Boot is growing, we need to
5188 establish some rules. Submissions which do not conform to these rules
5189 may be rejected, even when they contain important and valuable stuff.
5191 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5193 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
5194 see http://lists.denx.de/mailman/listinfo/u-boot
5196 When you send a patch, please include the following information with
5197 it:
5199 * For bug fixes: a description of the bug and how your patch fixes
5200 this bug. Please try to include a way of demonstrating that the
5201 patch actually fixes something.
5203 * For new features: a description of the feature and your
5204 implementation.
5206 * A CHANGELOG entry as plaintext (separate from the patch)
5208 * For major contributions, your entry to the CREDITS file
5210 * When you add support for a new board, don't forget to add this
5211 board to the MAINTAINERS file, too.
5213 * If your patch adds new configuration options, don't forget to
5214 document these in the README file.
5216 * The patch itself. If you are using git (which is *strongly*
5217 recommended) you can easily generate the patch using the
5218 "git format-patch". If you then use "git send-email" to send it to
5219 the U-Boot mailing list, you will avoid most of the common problems
5220 with some other mail clients.
5222 If you cannot use git, use "diff -purN OLD NEW". If your version of
5223 diff does not support these options, then get the latest version of
5224 GNU diff.
5226 The current directory when running this command shall be the parent
5227 directory of the U-Boot source tree (i. e. please make sure that
5228 your patch includes sufficient directory information for the
5229 affected files).
5231 We prefer patches as plain text. MIME attachments are discouraged,
5232 and compressed attachments must not be used.
5234 * If one logical set of modifications affects or creates several
5235 files, all these changes shall be submitted in a SINGLE patch file.
5237 * Changesets that contain different, unrelated modifications shall be
5238 submitted as SEPARATE patches, one patch per changeset.
5241 Notes:
5243 * Before sending the patch, run the MAKEALL script on your patched
5244 source tree and make sure that no errors or warnings are reported
5245 for any of the boards.
5247 * Keep your modifications to the necessary minimum: A patch
5248 containing several unrelated changes or arbitrary reformats will be
5249 returned with a request to re-formatting / split it.
5251 * If you modify existing code, make sure that your new code does not
5252 add to the memory footprint of the code ;-) Small is beautiful!
5253 When adding new features, these should compile conditionally only
5254 (using #ifdef), and the resulting code with the new feature
5255 disabled must not need more memory than the old code without your
5256 modification.
5258 * Remember that there is a size limit of 100 kB per message on the
5259 u-boot mailing list. Bigger patches will be moderated. If they are
5260 reasonable and not too big, they will be acknowledged. But patches
5261 bigger than the size limit should be avoided.