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1 #
2 # (C) Copyright 2000 - 2011
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 #
23
24 Summary:
25 ========
26
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.
32
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.
37
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.
44
45
46 Status:
47 =======
48
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.
52
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.
56
57
58 Where to get help:
59 ==================
60
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
67
68
69 Where to get source code:
70 =========================
71
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
75
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.
80
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
83
84
85 Where we come from:
86 ===================
87
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
102
103
104 Names and Spelling:
105 ===================
106
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:
110
111 This is the README file for the U-Boot project.
112
113 File names etc. shall be based on the string "u-boot". Examples:
114
115 include/asm-ppc/u-boot.h
116
117 #include <asm/u-boot.h>
118
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
121
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
124
125
126 Versioning:
127 ===========
128
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.
135
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
140
141
142 Directory Hierarchy:
143 ====================
144
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.
233
234 Software Configuration:
235 =======================
236
237 Configuration is usually done using C preprocessor defines; the
238 rationale behind that is to avoid dead code whenever possible.
239
240 There are two classes of configuration variables:
241
242 * Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
244 "CONFIG_".
245
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_".
250
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.
256
257
258 Selection of Processor Architecture and Board Type:
259 ---------------------------------------------------
260
261 For all supported boards there are ready-to-use default
262 configurations available; just type "make <board_name>_config".
263
264 Example: For a TQM823L module type:
265
266 cd u-boot
267 make TQM823L_config
268
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.
272
273
274 Configuration Options:
275 ----------------------
276
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".
280
281 Example: For a TQM823L module, all configuration settings are in
282 "include/configs/TQM823L.h".
283
284
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.
288
289
290 The following options need to be configured:
291
292 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
293
294 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
295
296 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
297 Define exactly one, e.g. CONFIG_ATSTK1002
298
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
305
306 - Motherboard Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
308 CONFIG_CMA101, CONFIG_CMA102
309
310 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
311 Define one or more of
312 CONFIG_CMA302
313
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" |\-/|\-/
319
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
327
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
332
333 - MPC824X Family Member (if CONFIG_MPC824X is defined)
334 Define exactly one of
335 CONFIG_MPC8240, CONFIG_MPC8245
336
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)
344
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
350
351 CONFIG_SYS_MEASURE_CPUCLK
352
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)
359
360 CONFIG_SYS_DELAYED_ICACHE
361
362 Define this option if you want to enable the
363 ICache only when Code runs from RAM.
364
365 - 85xx CPU Options:
366 CONFIG_SYS_FSL_TBCLK_DIV
367
368 Defines the core time base clock divider ratio compared to the
369 system clock. On most PQ3 devices this is 8, on newer QorIQ
370 devices it can be 16 or 32. The ratio varies from SoC to Soc.
371
372 CONFIG_SYS_FSL_PCIE_COMPAT
373
374 Defines the string to utilize when trying to match PCIe device
375 tree nodes for the given platform.
376
377 - Intel Monahans options:
378 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
379
380 Defines the Monahans run mode to oscillator
381 ratio. Valid values are 8, 16, 24, 31. The core
382 frequency is this value multiplied by 13 MHz.
383
384 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
385
386 Defines the Monahans turbo mode to oscillator
387 ratio. Valid values are 1 (default if undefined) and
388 2. The core frequency as calculated above is multiplied
389 by this value.
390
391 - MIPS CPU options:
392 CONFIG_SYS_INIT_SP_OFFSET
393
394 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
395 pointer. This is needed for the temporary stack before
396 relocation.
397
398 CONFIG_SYS_MIPS_CACHE_MODE
399
400 Cache operation mode for the MIPS CPU.
401 See also arch/mips/include/asm/mipsregs.h.
402 Possible values are:
403 CONF_CM_CACHABLE_NO_WA
404 CONF_CM_CACHABLE_WA
405 CONF_CM_UNCACHED
406 CONF_CM_CACHABLE_NONCOHERENT
407 CONF_CM_CACHABLE_CE
408 CONF_CM_CACHABLE_COW
409 CONF_CM_CACHABLE_CUW
410 CONF_CM_CACHABLE_ACCELERATED
411
412 CONFIG_SYS_XWAY_EBU_BOOTCFG
413
414 Special option for Lantiq XWAY SoCs for booting from NOR flash.
415 See also arch/mips/cpu/mips32/start.S.
416
417 CONFIG_XWAY_SWAP_BYTES
418
419 Enable compilation of tools/xway-swap-bytes needed for Lantiq
420 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
421 be swapped if a flash programmer is used.
422
423 - Linux Kernel Interface:
424 CONFIG_CLOCKS_IN_MHZ
425
426 U-Boot stores all clock information in Hz
427 internally. For binary compatibility with older Linux
428 kernels (which expect the clocks passed in the
429 bd_info data to be in MHz) the environment variable
430 "clocks_in_mhz" can be defined so that U-Boot
431 converts clock data to MHZ before passing it to the
432 Linux kernel.
433 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
434 "clocks_in_mhz=1" is automatically included in the
435 default environment.
436
437 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
438
439 When transferring memsize parameter to linux, some versions
440 expect it to be in bytes, others in MB.
441 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
442
443 CONFIG_OF_LIBFDT
444
445 New kernel versions are expecting firmware settings to be
446 passed using flattened device trees (based on open firmware
447 concepts).
448
449 CONFIG_OF_LIBFDT
450 * New libfdt-based support
451 * Adds the "fdt" command
452 * The bootm command automatically updates the fdt
453
454 OF_CPU - The proper name of the cpus node (only required for
455 MPC512X and MPC5xxx based boards).
456 OF_SOC - The proper name of the soc node (only required for
457 MPC512X and MPC5xxx based boards).
458 OF_TBCLK - The timebase frequency.
459 OF_STDOUT_PATH - The path to the console device
460
461 boards with QUICC Engines require OF_QE to set UCC MAC
462 addresses
463
464 CONFIG_OF_BOARD_SETUP
465
466 Board code has addition modification that it wants to make
467 to the flat device tree before handing it off to the kernel
468
469 CONFIG_OF_BOOT_CPU
470
471 This define fills in the correct boot CPU in the boot
472 param header, the default value is zero if undefined.
473
474 CONFIG_OF_IDE_FIXUP
475
476 U-Boot can detect if an IDE device is present or not.
477 If not, and this new config option is activated, U-Boot
478 removes the ATA node from the DTS before booting Linux,
479 so the Linux IDE driver does not probe the device and
480 crash. This is needed for buggy hardware (uc101) where
481 no pull down resistor is connected to the signal IDE5V_DD7.
482
483 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
484
485 This setting is mandatory for all boards that have only one
486 machine type and must be used to specify the machine type
487 number as it appears in the ARM machine registry
488 (see http://www.arm.linux.org.uk/developer/machines/).
489 Only boards that have multiple machine types supported
490 in a single configuration file and the machine type is
491 runtime discoverable, do not have to use this setting.
492
493 - vxWorks boot parameters:
494
495 bootvx constructs a valid bootline using the following
496 environments variables: bootfile, ipaddr, serverip, hostname.
497 It loads the vxWorks image pointed bootfile.
498
499 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
500 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
501 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
502 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
503
504 CONFIG_SYS_VXWORKS_ADD_PARAMS
505
506 Add it at the end of the bootline. E.g "u=username pw=secret"
507
508 Note: If a "bootargs" environment is defined, it will overwride
509 the defaults discussed just above.
510
511 - Cache Configuration:
512 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
513 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
514 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
515
516 - Cache Configuration for ARM:
517 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
518 controller
519 CONFIG_SYS_PL310_BASE - Physical base address of PL310
520 controller register space
521
522 - Serial Ports:
523 CONFIG_PL010_SERIAL
524
525 Define this if you want support for Amba PrimeCell PL010 UARTs.
526
527 CONFIG_PL011_SERIAL
528
529 Define this if you want support for Amba PrimeCell PL011 UARTs.
530
531 CONFIG_PL011_CLOCK
532
533 If you have Amba PrimeCell PL011 UARTs, set this variable to
534 the clock speed of the UARTs.
535
536 CONFIG_PL01x_PORTS
537
538 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
539 define this to a list of base addresses for each (supported)
540 port. See e.g. include/configs/versatile.h
541
542 CONFIG_PL011_SERIAL_RLCR
543
544 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
545 have separate receive and transmit line control registers. Set
546 this variable to initialize the extra register.
547
548 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
549
550 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
551 boot loader that has already initialized the UART. Define this
552 variable to flush the UART at init time.
553
554
555 - Console Interface:
556 Depending on board, define exactly one serial port
557 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
558 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
559 console by defining CONFIG_8xx_CONS_NONE
560
561 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
562 port routines must be defined elsewhere
563 (i.e. serial_init(), serial_getc(), ...)
564
565 CONFIG_CFB_CONSOLE
566 Enables console device for a color framebuffer. Needs following
567 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
568 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
569 (default big endian)
570 VIDEO_HW_RECTFILL graphic chip supports
571 rectangle fill
572 (cf. smiLynxEM)
573 VIDEO_HW_BITBLT graphic chip supports
574 bit-blit (cf. smiLynxEM)
575 VIDEO_VISIBLE_COLS visible pixel columns
576 (cols=pitch)
577 VIDEO_VISIBLE_ROWS visible pixel rows
578 VIDEO_PIXEL_SIZE bytes per pixel
579 VIDEO_DATA_FORMAT graphic data format
580 (0-5, cf. cfb_console.c)
581 VIDEO_FB_ADRS framebuffer address
582 VIDEO_KBD_INIT_FCT keyboard int fct
583 (i.e. i8042_kbd_init())
584 VIDEO_TSTC_FCT test char fct
585 (i.e. i8042_tstc)
586 VIDEO_GETC_FCT get char fct
587 (i.e. i8042_getc)
588 CONFIG_CONSOLE_CURSOR cursor drawing on/off
589 (requires blink timer
590 cf. i8042.c)
591 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
592 CONFIG_CONSOLE_TIME display time/date info in
593 upper right corner
594 (requires CONFIG_CMD_DATE)
595 CONFIG_VIDEO_LOGO display Linux logo in
596 upper left corner
597 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
598 linux_logo.h for logo.
599 Requires CONFIG_VIDEO_LOGO
600 CONFIG_CONSOLE_EXTRA_INFO
601 additional board info beside
602 the logo
603
604 When CONFIG_CFB_CONSOLE is defined, video console is
605 default i/o. Serial console can be forced with
606 environment 'console=serial'.
607
608 When CONFIG_SILENT_CONSOLE is defined, all console
609 messages (by U-Boot and Linux!) can be silenced with
610 the "silent" environment variable. See
611 doc/README.silent for more information.
612
613 - Console Baudrate:
614 CONFIG_BAUDRATE - in bps
615 Select one of the baudrates listed in
616 CONFIG_SYS_BAUDRATE_TABLE, see below.
617 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
618
619 - Console Rx buffer length
620 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
621 the maximum receive buffer length for the SMC.
622 This option is actual only for 82xx and 8xx possible.
623 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
624 must be defined, to setup the maximum idle timeout for
625 the SMC.
626
627 - Pre-Console Buffer:
628 Prior to the console being initialised (i.e. serial UART
629 initialised etc) all console output is silently discarded.
630 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
631 buffer any console messages prior to the console being
632 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
633 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
634 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
635 bytes are output before the console is initialised, the
636 earlier bytes are discarded.
637
638 'Sane' compilers will generate smaller code if
639 CONFIG_PRE_CON_BUF_SZ is a power of 2
640
641 - Boot Delay: CONFIG_BOOTDELAY - in seconds
642 Delay before automatically booting the default image;
643 set to -1 to disable autoboot.
644
645 See doc/README.autoboot for these options that
646 work with CONFIG_BOOTDELAY. None are required.
647 CONFIG_BOOT_RETRY_TIME
648 CONFIG_BOOT_RETRY_MIN
649 CONFIG_AUTOBOOT_KEYED
650 CONFIG_AUTOBOOT_PROMPT
651 CONFIG_AUTOBOOT_DELAY_STR
652 CONFIG_AUTOBOOT_STOP_STR
653 CONFIG_AUTOBOOT_DELAY_STR2
654 CONFIG_AUTOBOOT_STOP_STR2
655 CONFIG_ZERO_BOOTDELAY_CHECK
656 CONFIG_RESET_TO_RETRY
657
658 - Autoboot Command:
659 CONFIG_BOOTCOMMAND
660 Only needed when CONFIG_BOOTDELAY is enabled;
661 define a command string that is automatically executed
662 when no character is read on the console interface
663 within "Boot Delay" after reset.
664
665 CONFIG_BOOTARGS
666 This can be used to pass arguments to the bootm
667 command. The value of CONFIG_BOOTARGS goes into the
668 environment value "bootargs".
669
670 CONFIG_RAMBOOT and CONFIG_NFSBOOT
671 The value of these goes into the environment as
672 "ramboot" and "nfsboot" respectively, and can be used
673 as a convenience, when switching between booting from
674 RAM and NFS.
675
676 - Pre-Boot Commands:
677 CONFIG_PREBOOT
678
679 When this option is #defined, the existence of the
680 environment variable "preboot" will be checked
681 immediately before starting the CONFIG_BOOTDELAY
682 countdown and/or running the auto-boot command resp.
683 entering interactive mode.
684
685 This feature is especially useful when "preboot" is
686 automatically generated or modified. For an example
687 see the LWMON board specific code: here "preboot" is
688 modified when the user holds down a certain
689 combination of keys on the (special) keyboard when
690 booting the systems
691
692 - Serial Download Echo Mode:
693 CONFIG_LOADS_ECHO
694 If defined to 1, all characters received during a
695 serial download (using the "loads" command) are
696 echoed back. This might be needed by some terminal
697 emulations (like "cu"), but may as well just take
698 time on others. This setting #define's the initial
699 value of the "loads_echo" environment variable.
700
701 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
702 CONFIG_KGDB_BAUDRATE
703 Select one of the baudrates listed in
704 CONFIG_SYS_BAUDRATE_TABLE, see below.
705
706 - Monitor Functions:
707 Monitor commands can be included or excluded
708 from the build by using the #include files
709 "config_cmd_all.h" and #undef'ing unwanted
710 commands, or using "config_cmd_default.h"
711 and augmenting with additional #define's
712 for wanted commands.
713
714 The default command configuration includes all commands
715 except those marked below with a "*".
716
717 CONFIG_CMD_ASKENV * ask for env variable
718 CONFIG_CMD_BDI bdinfo
719 CONFIG_CMD_BEDBUG * Include BedBug Debugger
720 CONFIG_CMD_BMP * BMP support
721 CONFIG_CMD_BSP * Board specific commands
722 CONFIG_CMD_BOOTD bootd
723 CONFIG_CMD_CACHE * icache, dcache
724 CONFIG_CMD_CONSOLE coninfo
725 CONFIG_CMD_CRC32 * crc32
726 CONFIG_CMD_DATE * support for RTC, date/time...
727 CONFIG_CMD_DHCP * DHCP support
728 CONFIG_CMD_DIAG * Diagnostics
729 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
730 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
731 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
732 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
733 CONFIG_CMD_DTT * Digital Therm and Thermostat
734 CONFIG_CMD_ECHO echo arguments
735 CONFIG_CMD_EDITENV edit env variable
736 CONFIG_CMD_EEPROM * EEPROM read/write support
737 CONFIG_CMD_ELF * bootelf, bootvx
738 CONFIG_CMD_EXPORTENV * export the environment
739 CONFIG_CMD_SAVEENV saveenv
740 CONFIG_CMD_FDC * Floppy Disk Support
741 CONFIG_CMD_FAT * FAT partition support
742 CONFIG_CMD_FDOS * Dos diskette Support
743 CONFIG_CMD_FLASH flinfo, erase, protect
744 CONFIG_CMD_FPGA FPGA device initialization support
745 CONFIG_CMD_GO * the 'go' command (exec code)
746 CONFIG_CMD_GREPENV * search environment
747 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
748 CONFIG_CMD_I2C * I2C serial bus support
749 CONFIG_CMD_IDE * IDE harddisk support
750 CONFIG_CMD_IMI iminfo
751 CONFIG_CMD_IMLS List all found images
752 CONFIG_CMD_IMMAP * IMMR dump support
753 CONFIG_CMD_IMPORTENV * import an environment
754 CONFIG_CMD_IRQ * irqinfo
755 CONFIG_CMD_ITEST Integer/string test of 2 values
756 CONFIG_CMD_JFFS2 * JFFS2 Support
757 CONFIG_CMD_KGDB * kgdb
758 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
759 CONFIG_CMD_LOADB loadb
760 CONFIG_CMD_LOADS loads
761 CONFIG_CMD_MD5SUM print md5 message digest
762 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
763 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
764 loop, loopw, mtest
765 CONFIG_CMD_MISC Misc functions like sleep etc
766 CONFIG_CMD_MMC * MMC memory mapped support
767 CONFIG_CMD_MII * MII utility commands
768 CONFIG_CMD_MTDPARTS * MTD partition support
769 CONFIG_CMD_NAND * NAND support
770 CONFIG_CMD_NET bootp, tftpboot, rarpboot
771 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
772 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
773 CONFIG_CMD_PCI * pciinfo
774 CONFIG_CMD_PCMCIA * PCMCIA support
775 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
776 host
777 CONFIG_CMD_PORTIO * Port I/O
778 CONFIG_CMD_REGINFO * Register dump
779 CONFIG_CMD_RUN run command in env variable
780 CONFIG_CMD_SAVES * save S record dump
781 CONFIG_CMD_SCSI * SCSI Support
782 CONFIG_CMD_SDRAM * print SDRAM configuration information
783 (requires CONFIG_CMD_I2C)
784 CONFIG_CMD_SETGETDCR Support for DCR Register access
785 (4xx only)
786 CONFIG_CMD_SHA1SUM print sha1 memory digest
787 (requires CONFIG_CMD_MEMORY)
788 CONFIG_CMD_SOURCE "source" command Support
789 CONFIG_CMD_SPI * SPI serial bus support
790 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
791 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
792 CONFIG_CMD_TIME * run command and report execution time
793 CONFIG_CMD_USB * USB support
794 CONFIG_CMD_CDP * Cisco Discover Protocol support
795 CONFIG_CMD_FSL * Microblaze FSL support
796
797
798 EXAMPLE: If you want all functions except of network
799 support you can write:
800
801 #include "config_cmd_all.h"
802 #undef CONFIG_CMD_NET
803
804 Other Commands:
805 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
806
807 Note: Don't enable the "icache" and "dcache" commands
808 (configuration option CONFIG_CMD_CACHE) unless you know
809 what you (and your U-Boot users) are doing. Data
810 cache cannot be enabled on systems like the 8xx or
811 8260 (where accesses to the IMMR region must be
812 uncached), and it cannot be disabled on all other
813 systems where we (mis-) use the data cache to hold an
814 initial stack and some data.
815
816
817 XXX - this list needs to get updated!
818
819 - Device tree:
820 CONFIG_OF_CONTROL
821 If this variable is defined, U-Boot will use a device tree
822 to configure its devices, instead of relying on statically
823 compiled #defines in the board file. This option is
824 experimental and only available on a few boards. The device
825 tree is available in the global data as gd->fdt_blob.
826
827 U-Boot needs to get its device tree from somewhere. This can
828 be done using one of the two options below:
829
830 CONFIG_OF_EMBED
831 If this variable is defined, U-Boot will embed a device tree
832 binary in its image. This device tree file should be in the
833 board directory and called <soc>-<board>.dts. The binary file
834 is then picked up in board_init_f() and made available through
835 the global data structure as gd->blob.
836
837 CONFIG_OF_SEPARATE
838 If this variable is defined, U-Boot will build a device tree
839 binary. It will be called u-boot.dtb. Architecture-specific
840 code will locate it at run-time. Generally this works by:
841
842 cat u-boot.bin u-boot.dtb >image.bin
843
844 and in fact, U-Boot does this for you, creating a file called
845 u-boot-dtb.bin which is useful in the common case. You can
846 still use the individual files if you need something more
847 exotic.
848
849 - Watchdog:
850 CONFIG_WATCHDOG
851 If this variable is defined, it enables watchdog
852 support for the SoC. There must be support in the SoC
853 specific code for a watchdog. For the 8xx and 8260
854 CPUs, the SIU Watchdog feature is enabled in the SYPCR
855 register. When supported for a specific SoC is
856 available, then no further board specific code should
857 be needed to use it.
858
859 CONFIG_HW_WATCHDOG
860 When using a watchdog circuitry external to the used
861 SoC, then define this variable and provide board
862 specific code for the "hw_watchdog_reset" function.
863
864 - U-Boot Version:
865 CONFIG_VERSION_VARIABLE
866 If this variable is defined, an environment variable
867 named "ver" is created by U-Boot showing the U-Boot
868 version as printed by the "version" command.
869 This variable is readonly.
870
871 - Real-Time Clock:
872
873 When CONFIG_CMD_DATE is selected, the type of the RTC
874 has to be selected, too. Define exactly one of the
875 following options:
876
877 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
878 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
879 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
880 CONFIG_RTC_MC146818 - use MC146818 RTC
881 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
882 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
883 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
884 CONFIG_RTC_DS164x - use Dallas DS164x RTC
885 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
886 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
887 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
888 CONFIG_SYS_RV3029_TCR - enable trickle charger on
889 RV3029 RTC.
890
891 Note that if the RTC uses I2C, then the I2C interface
892 must also be configured. See I2C Support, below.
893
894 - GPIO Support:
895 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
896 CONFIG_PCA953X_INFO - enable pca953x info command
897
898 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
899 chip-ngpio pairs that tell the PCA953X driver the number of
900 pins supported by a particular chip.
901
902 Note that if the GPIO device uses I2C, then the I2C interface
903 must also be configured. See I2C Support, below.
904
905 - Timestamp Support:
906
907 When CONFIG_TIMESTAMP is selected, the timestamp
908 (date and time) of an image is printed by image
909 commands like bootm or iminfo. This option is
910 automatically enabled when you select CONFIG_CMD_DATE .
911
912 - Partition Support:
913 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
914 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
915
916 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
917 CONFIG_CMD_SCSI) you must configure support for at
918 least one partition type as well.
919
920 - IDE Reset method:
921 CONFIG_IDE_RESET_ROUTINE - this is defined in several
922 board configurations files but used nowhere!
923
924 CONFIG_IDE_RESET - is this is defined, IDE Reset will
925 be performed by calling the function
926 ide_set_reset(int reset)
927 which has to be defined in a board specific file
928
929 - ATAPI Support:
930 CONFIG_ATAPI
931
932 Set this to enable ATAPI support.
933
934 - LBA48 Support
935 CONFIG_LBA48
936
937 Set this to enable support for disks larger than 137GB
938 Also look at CONFIG_SYS_64BIT_LBA.
939 Whithout these , LBA48 support uses 32bit variables and will 'only'
940 support disks up to 2.1TB.
941
942 CONFIG_SYS_64BIT_LBA:
943 When enabled, makes the IDE subsystem use 64bit sector addresses.
944 Default is 32bit.
945
946 - SCSI Support:
947 At the moment only there is only support for the
948 SYM53C8XX SCSI controller; define
949 CONFIG_SCSI_SYM53C8XX to enable it.
950
951 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
952 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
953 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
954 maximum numbers of LUNs, SCSI ID's and target
955 devices.
956 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
957
958 - NETWORK Support (PCI):
959 CONFIG_E1000
960 Support for Intel 8254x/8257x gigabit chips.
961
962 CONFIG_E1000_SPI
963 Utility code for direct access to the SPI bus on Intel 8257x.
964 This does not do anything useful unless you set at least one
965 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
966
967 CONFIG_E1000_SPI_GENERIC
968 Allow generic access to the SPI bus on the Intel 8257x, for
969 example with the "sspi" command.
970
971 CONFIG_CMD_E1000
972 Management command for E1000 devices. When used on devices
973 with SPI support you can reprogram the EEPROM from U-Boot.
974
975 CONFIG_E1000_FALLBACK_MAC
976 default MAC for empty EEPROM after production.
977
978 CONFIG_EEPRO100
979 Support for Intel 82557/82559/82559ER chips.
980 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
981 write routine for first time initialisation.
982
983 CONFIG_TULIP
984 Support for Digital 2114x chips.
985 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
986 modem chip initialisation (KS8761/QS6611).
987
988 CONFIG_NATSEMI
989 Support for National dp83815 chips.
990
991 CONFIG_NS8382X
992 Support for National dp8382[01] gigabit chips.
993
994 - NETWORK Support (other):
995
996 CONFIG_DRIVER_AT91EMAC
997 Support for AT91RM9200 EMAC.
998
999 CONFIG_RMII
1000 Define this to use reduced MII inteface
1001
1002 CONFIG_DRIVER_AT91EMAC_QUIET
1003 If this defined, the driver is quiet.
1004 The driver doen't show link status messages.
1005
1006 CONFIG_DRIVER_LAN91C96
1007 Support for SMSC's LAN91C96 chips.
1008
1009 CONFIG_LAN91C96_BASE
1010 Define this to hold the physical address
1011 of the LAN91C96's I/O space
1012
1013 CONFIG_LAN91C96_USE_32_BIT
1014 Define this to enable 32 bit addressing
1015
1016 CONFIG_DRIVER_SMC91111
1017 Support for SMSC's LAN91C111 chip
1018
1019 CONFIG_SMC91111_BASE
1020 Define this to hold the physical address
1021 of the device (I/O space)
1022
1023 CONFIG_SMC_USE_32_BIT
1024 Define this if data bus is 32 bits
1025
1026 CONFIG_SMC_USE_IOFUNCS
1027 Define this to use i/o functions instead of macros
1028 (some hardware wont work with macros)
1029
1030 CONFIG_FTGMAC100
1031 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1032
1033 CONFIG_FTGMAC100_EGIGA
1034 Define this to use GE link update with gigabit PHY.
1035 Define this if FTGMAC100 is connected to gigabit PHY.
1036 If your system has 10/100 PHY only, it might not occur
1037 wrong behavior. Because PHY usually return timeout or
1038 useless data when polling gigabit status and gigabit
1039 control registers. This behavior won't affect the
1040 correctnessof 10/100 link speed update.
1041
1042 CONFIG_SMC911X
1043 Support for SMSC's LAN911x and LAN921x chips
1044
1045 CONFIG_SMC911X_BASE
1046 Define this to hold the physical address
1047 of the device (I/O space)
1048
1049 CONFIG_SMC911X_32_BIT
1050 Define this if data bus is 32 bits
1051
1052 CONFIG_SMC911X_16_BIT
1053 Define this if data bus is 16 bits. If your processor
1054 automatically converts one 32 bit word to two 16 bit
1055 words you may also try CONFIG_SMC911X_32_BIT.
1056
1057 CONFIG_SH_ETHER
1058 Support for Renesas on-chip Ethernet controller
1059
1060 CONFIG_SH_ETHER_USE_PORT
1061 Define the number of ports to be used
1062
1063 CONFIG_SH_ETHER_PHY_ADDR
1064 Define the ETH PHY's address
1065
1066 CONFIG_SH_ETHER_CACHE_WRITEBACK
1067 If this option is set, the driver enables cache flush.
1068
1069 - USB Support:
1070 At the moment only the UHCI host controller is
1071 supported (PIP405, MIP405, MPC5200); define
1072 CONFIG_USB_UHCI to enable it.
1073 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1074 and define CONFIG_USB_STORAGE to enable the USB
1075 storage devices.
1076 Note:
1077 Supported are USB Keyboards and USB Floppy drives
1078 (TEAC FD-05PUB).
1079 MPC5200 USB requires additional defines:
1080 CONFIG_USB_CLOCK
1081 for 528 MHz Clock: 0x0001bbbb
1082 CONFIG_PSC3_USB
1083 for USB on PSC3
1084 CONFIG_USB_CONFIG
1085 for differential drivers: 0x00001000
1086 for single ended drivers: 0x00005000
1087 for differential drivers on PSC3: 0x00000100
1088 for single ended drivers on PSC3: 0x00004100
1089 CONFIG_SYS_USB_EVENT_POLL
1090 May be defined to allow interrupt polling
1091 instead of using asynchronous interrupts
1092
1093 - USB Device:
1094 Define the below if you wish to use the USB console.
1095 Once firmware is rebuilt from a serial console issue the
1096 command "setenv stdin usbtty; setenv stdout usbtty" and
1097 attach your USB cable. The Unix command "dmesg" should print
1098 it has found a new device. The environment variable usbtty
1099 can be set to gserial or cdc_acm to enable your device to
1100 appear to a USB host as a Linux gserial device or a
1101 Common Device Class Abstract Control Model serial device.
1102 If you select usbtty = gserial you should be able to enumerate
1103 a Linux host by
1104 # modprobe usbserial vendor=0xVendorID product=0xProductID
1105 else if using cdc_acm, simply setting the environment
1106 variable usbtty to be cdc_acm should suffice. The following
1107 might be defined in YourBoardName.h
1108
1109 CONFIG_USB_DEVICE
1110 Define this to build a UDC device
1111
1112 CONFIG_USB_TTY
1113 Define this to have a tty type of device available to
1114 talk to the UDC device
1115
1116 CONFIG_SYS_CONSOLE_IS_IN_ENV
1117 Define this if you want stdin, stdout &/or stderr to
1118 be set to usbtty.
1119
1120 mpc8xx:
1121 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1122 Derive USB clock from external clock "blah"
1123 - CONFIG_SYS_USB_EXTC_CLK 0x02
1124
1125 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1126 Derive USB clock from brgclk
1127 - CONFIG_SYS_USB_BRG_CLK 0x04
1128
1129 If you have a USB-IF assigned VendorID then you may wish to
1130 define your own vendor specific values either in BoardName.h
1131 or directly in usbd_vendor_info.h. If you don't define
1132 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1133 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1134 should pretend to be a Linux device to it's target host.
1135
1136 CONFIG_USBD_MANUFACTURER
1137 Define this string as the name of your company for
1138 - CONFIG_USBD_MANUFACTURER "my company"
1139
1140 CONFIG_USBD_PRODUCT_NAME
1141 Define this string as the name of your product
1142 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1143
1144 CONFIG_USBD_VENDORID
1145 Define this as your assigned Vendor ID from the USB
1146 Implementors Forum. This *must* be a genuine Vendor ID
1147 to avoid polluting the USB namespace.
1148 - CONFIG_USBD_VENDORID 0xFFFF
1149
1150 CONFIG_USBD_PRODUCTID
1151 Define this as the unique Product ID
1152 for your device
1153 - CONFIG_USBD_PRODUCTID 0xFFFF
1154
1155
1156 - MMC Support:
1157 The MMC controller on the Intel PXA is supported. To
1158 enable this define CONFIG_MMC. The MMC can be
1159 accessed from the boot prompt by mapping the device
1160 to physical memory similar to flash. Command line is
1161 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1162 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1163
1164 CONFIG_SH_MMCIF
1165 Support for Renesas on-chip MMCIF controller
1166
1167 CONFIG_SH_MMCIF_ADDR
1168 Define the base address of MMCIF registers
1169
1170 CONFIG_SH_MMCIF_CLK
1171 Define the clock frequency for MMCIF
1172
1173 - Journaling Flash filesystem support:
1174 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1175 CONFIG_JFFS2_NAND_DEV
1176 Define these for a default partition on a NAND device
1177
1178 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1179 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1180 Define these for a default partition on a NOR device
1181
1182 CONFIG_SYS_JFFS_CUSTOM_PART
1183 Define this to create an own partition. You have to provide a
1184 function struct part_info* jffs2_part_info(int part_num)
1185
1186 If you define only one JFFS2 partition you may also want to
1187 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1188 to disable the command chpart. This is the default when you
1189 have not defined a custom partition
1190
1191 - FAT(File Allocation Table) filesystem write function support:
1192 CONFIG_FAT_WRITE
1193 Support for saving memory data as a file
1194 in FAT formatted partition
1195
1196 - Keyboard Support:
1197 CONFIG_ISA_KEYBOARD
1198
1199 Define this to enable standard (PC-Style) keyboard
1200 support
1201
1202 CONFIG_I8042_KBD
1203 Standard PC keyboard driver with US (is default) and
1204 GERMAN key layout (switch via environment 'keymap=de') support.
1205 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1206 for cfb_console. Supports cursor blinking.
1207
1208 - Video support:
1209 CONFIG_VIDEO
1210
1211 Define this to enable video support (for output to
1212 video).
1213
1214 CONFIG_VIDEO_CT69000
1215
1216 Enable Chips & Technologies 69000 Video chip
1217
1218 CONFIG_VIDEO_SMI_LYNXEM
1219 Enable Silicon Motion SMI 712/710/810 Video chip. The
1220 video output is selected via environment 'videoout'
1221 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1222 assumed.
1223
1224 For the CT69000 and SMI_LYNXEM drivers, videomode is
1225 selected via environment 'videomode'. Two different ways
1226 are possible:
1227 - "videomode=num" 'num' is a standard LiLo mode numbers.
1228 Following standard modes are supported (* is default):
1229
1230 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1231 -------------+---------------------------------------------
1232 8 bits | 0x301* 0x303 0x305 0x161 0x307
1233 15 bits | 0x310 0x313 0x316 0x162 0x319
1234 16 bits | 0x311 0x314 0x317 0x163 0x31A
1235 24 bits | 0x312 0x315 0x318 ? 0x31B
1236 -------------+---------------------------------------------
1237 (i.e. setenv videomode 317; saveenv; reset;)
1238
1239 - "videomode=bootargs" all the video parameters are parsed
1240 from the bootargs. (See drivers/video/videomodes.c)
1241
1242
1243 CONFIG_VIDEO_SED13806
1244 Enable Epson SED13806 driver. This driver supports 8bpp
1245 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1246 or CONFIG_VIDEO_SED13806_16BPP
1247
1248 CONFIG_FSL_DIU_FB
1249 Enable the Freescale DIU video driver. Reference boards for
1250 SOCs that have a DIU should define this macro to enable DIU
1251 support, and should also define these other macros:
1252
1253 CONFIG_SYS_DIU_ADDR
1254 CONFIG_VIDEO
1255 CONFIG_CMD_BMP
1256 CONFIG_CFB_CONSOLE
1257 CONFIG_VIDEO_SW_CURSOR
1258 CONFIG_VGA_AS_SINGLE_DEVICE
1259 CONFIG_VIDEO_LOGO
1260 CONFIG_VIDEO_BMP_LOGO
1261
1262 The DIU driver will look for the 'video-mode' environment
1263 variable, and if defined, enable the DIU as a console during
1264 boot. See the documentation file README.video for a
1265 description of this variable.
1266
1267 - Keyboard Support:
1268 CONFIG_KEYBOARD
1269
1270 Define this to enable a custom keyboard support.
1271 This simply calls drv_keyboard_init() which must be
1272 defined in your board-specific files.
1273 The only board using this so far is RBC823.
1274
1275 - LCD Support: CONFIG_LCD
1276
1277 Define this to enable LCD support (for output to LCD
1278 display); also select one of the supported displays
1279 by defining one of these:
1280
1281 CONFIG_ATMEL_LCD:
1282
1283 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1284
1285 CONFIG_NEC_NL6448AC33:
1286
1287 NEC NL6448AC33-18. Active, color, single scan.
1288
1289 CONFIG_NEC_NL6448BC20
1290
1291 NEC NL6448BC20-08. 6.5", 640x480.
1292 Active, color, single scan.
1293
1294 CONFIG_NEC_NL6448BC33_54
1295
1296 NEC NL6448BC33-54. 10.4", 640x480.
1297 Active, color, single scan.
1298
1299 CONFIG_SHARP_16x9
1300
1301 Sharp 320x240. Active, color, single scan.
1302 It isn't 16x9, and I am not sure what it is.
1303
1304 CONFIG_SHARP_LQ64D341
1305
1306 Sharp LQ64D341 display, 640x480.
1307 Active, color, single scan.
1308
1309 CONFIG_HLD1045
1310
1311 HLD1045 display, 640x480.
1312 Active, color, single scan.
1313
1314 CONFIG_OPTREX_BW
1315
1316 Optrex CBL50840-2 NF-FW 99 22 M5
1317 or
1318 Hitachi LMG6912RPFC-00T
1319 or
1320 Hitachi SP14Q002
1321
1322 320x240. Black & white.
1323
1324 Normally display is black on white background; define
1325 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1326
1327 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1328
1329 If this option is set, the environment is checked for
1330 a variable "splashimage". If found, the usual display
1331 of logo, copyright and system information on the LCD
1332 is suppressed and the BMP image at the address
1333 specified in "splashimage" is loaded instead. The
1334 console is redirected to the "nulldev", too. This
1335 allows for a "silent" boot where a splash screen is
1336 loaded very quickly after power-on.
1337
1338 CONFIG_SPLASH_SCREEN_ALIGN
1339
1340 If this option is set the splash image can be freely positioned
1341 on the screen. Environment variable "splashpos" specifies the
1342 position as "x,y". If a positive number is given it is used as
1343 number of pixel from left/top. If a negative number is given it
1344 is used as number of pixel from right/bottom. You can also
1345 specify 'm' for centering the image.
1346
1347 Example:
1348 setenv splashpos m,m
1349 => image at center of screen
1350
1351 setenv splashpos 30,20
1352 => image at x = 30 and y = 20
1353
1354 setenv splashpos -10,m
1355 => vertically centered image
1356 at x = dspWidth - bmpWidth - 9
1357
1358 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1359
1360 If this option is set, additionally to standard BMP
1361 images, gzipped BMP images can be displayed via the
1362 splashscreen support or the bmp command.
1363
1364 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1365
1366 If this option is set, 8-bit RLE compressed BMP images
1367 can be displayed via the splashscreen support or the
1368 bmp command.
1369
1370 - Compression support:
1371 CONFIG_BZIP2
1372
1373 If this option is set, support for bzip2 compressed
1374 images is included. If not, only uncompressed and gzip
1375 compressed images are supported.
1376
1377 NOTE: the bzip2 algorithm requires a lot of RAM, so
1378 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1379 be at least 4MB.
1380
1381 CONFIG_LZMA
1382
1383 If this option is set, support for lzma compressed
1384 images is included.
1385
1386 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1387 requires an amount of dynamic memory that is given by the
1388 formula:
1389
1390 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1391
1392 Where lc and lp stand for, respectively, Literal context bits
1393 and Literal pos bits.
1394
1395 This value is upper-bounded by 14MB in the worst case. Anyway,
1396 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1397 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1398 a very small buffer.
1399
1400 Use the lzmainfo tool to determinate the lc and lp values and
1401 then calculate the amount of needed dynamic memory (ensuring
1402 the appropriate CONFIG_SYS_MALLOC_LEN value).
1403
1404 - MII/PHY support:
1405 CONFIG_PHY_ADDR
1406
1407 The address of PHY on MII bus.
1408
1409 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1410
1411 The clock frequency of the MII bus
1412
1413 CONFIG_PHY_GIGE
1414
1415 If this option is set, support for speed/duplex
1416 detection of gigabit PHY is included.
1417
1418 CONFIG_PHY_RESET_DELAY
1419
1420 Some PHY like Intel LXT971A need extra delay after
1421 reset before any MII register access is possible.
1422 For such PHY, set this option to the usec delay
1423 required. (minimum 300usec for LXT971A)
1424
1425 CONFIG_PHY_CMD_DELAY (ppc4xx)
1426
1427 Some PHY like Intel LXT971A need extra delay after
1428 command issued before MII status register can be read
1429
1430 - Ethernet address:
1431 CONFIG_ETHADDR
1432 CONFIG_ETH1ADDR
1433 CONFIG_ETH2ADDR
1434 CONFIG_ETH3ADDR
1435 CONFIG_ETH4ADDR
1436 CONFIG_ETH5ADDR
1437
1438 Define a default value for Ethernet address to use
1439 for the respective Ethernet interface, in case this
1440 is not determined automatically.
1441
1442 - IP address:
1443 CONFIG_IPADDR
1444
1445 Define a default value for the IP address to use for
1446 the default Ethernet interface, in case this is not
1447 determined through e.g. bootp.
1448 (Environment variable "ipaddr")
1449
1450 - Server IP address:
1451 CONFIG_SERVERIP
1452
1453 Defines a default value for the IP address of a TFTP
1454 server to contact when using the "tftboot" command.
1455 (Environment variable "serverip")
1456
1457 CONFIG_KEEP_SERVERADDR
1458
1459 Keeps the server's MAC address, in the env 'serveraddr'
1460 for passing to bootargs (like Linux's netconsole option)
1461
1462 - Gateway IP address:
1463 CONFIG_GATEWAYIP
1464
1465 Defines a default value for the IP address of the
1466 default router where packets to other networks are
1467 sent to.
1468 (Environment variable "gatewayip")
1469
1470 - Subnet mask:
1471 CONFIG_NETMASK
1472
1473 Defines a default value for the subnet mask (or
1474 routing prefix) which is used to determine if an IP
1475 address belongs to the local subnet or needs to be
1476 forwarded through a router.
1477 (Environment variable "netmask")
1478
1479 - Multicast TFTP Mode:
1480 CONFIG_MCAST_TFTP
1481
1482 Defines whether you want to support multicast TFTP as per
1483 rfc-2090; for example to work with atftp. Lets lots of targets
1484 tftp down the same boot image concurrently. Note: the Ethernet
1485 driver in use must provide a function: mcast() to join/leave a
1486 multicast group.
1487
1488 - BOOTP Recovery Mode:
1489 CONFIG_BOOTP_RANDOM_DELAY
1490
1491 If you have many targets in a network that try to
1492 boot using BOOTP, you may want to avoid that all
1493 systems send out BOOTP requests at precisely the same
1494 moment (which would happen for instance at recovery
1495 from a power failure, when all systems will try to
1496 boot, thus flooding the BOOTP server. Defining
1497 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1498 inserted before sending out BOOTP requests. The
1499 following delays are inserted then:
1500
1501 1st BOOTP request: delay 0 ... 1 sec
1502 2nd BOOTP request: delay 0 ... 2 sec
1503 3rd BOOTP request: delay 0 ... 4 sec
1504 4th and following
1505 BOOTP requests: delay 0 ... 8 sec
1506
1507 - DHCP Advanced Options:
1508 You can fine tune the DHCP functionality by defining
1509 CONFIG_BOOTP_* symbols:
1510
1511 CONFIG_BOOTP_SUBNETMASK
1512 CONFIG_BOOTP_GATEWAY
1513 CONFIG_BOOTP_HOSTNAME
1514 CONFIG_BOOTP_NISDOMAIN
1515 CONFIG_BOOTP_BOOTPATH
1516 CONFIG_BOOTP_BOOTFILESIZE
1517 CONFIG_BOOTP_DNS
1518 CONFIG_BOOTP_DNS2
1519 CONFIG_BOOTP_SEND_HOSTNAME
1520 CONFIG_BOOTP_NTPSERVER
1521 CONFIG_BOOTP_TIMEOFFSET
1522 CONFIG_BOOTP_VENDOREX
1523
1524 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1525 environment variable, not the BOOTP server.
1526
1527 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1528 serverip from a DHCP server, it is possible that more
1529 than one DNS serverip is offered to the client.
1530 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1531 serverip will be stored in the additional environment
1532 variable "dnsip2". The first DNS serverip is always
1533 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1534 is defined.
1535
1536 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1537 to do a dynamic update of a DNS server. To do this, they
1538 need the hostname of the DHCP requester.
1539 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1540 of the "hostname" environment variable is passed as
1541 option 12 to the DHCP server.
1542
1543 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1544
1545 A 32bit value in microseconds for a delay between
1546 receiving a "DHCP Offer" and sending the "DHCP Request".
1547 This fixes a problem with certain DHCP servers that don't
1548 respond 100% of the time to a "DHCP request". E.g. On an
1549 AT91RM9200 processor running at 180MHz, this delay needed
1550 to be *at least* 15,000 usec before a Windows Server 2003
1551 DHCP server would reply 100% of the time. I recommend at
1552 least 50,000 usec to be safe. The alternative is to hope
1553 that one of the retries will be successful but note that
1554 the DHCP timeout and retry process takes a longer than
1555 this delay.
1556
1557 - CDP Options:
1558 CONFIG_CDP_DEVICE_ID
1559
1560 The device id used in CDP trigger frames.
1561
1562 CONFIG_CDP_DEVICE_ID_PREFIX
1563
1564 A two character string which is prefixed to the MAC address
1565 of the device.
1566
1567 CONFIG_CDP_PORT_ID
1568
1569 A printf format string which contains the ascii name of
1570 the port. Normally is set to "eth%d" which sets
1571 eth0 for the first Ethernet, eth1 for the second etc.
1572
1573 CONFIG_CDP_CAPABILITIES
1574
1575 A 32bit integer which indicates the device capabilities;
1576 0x00000010 for a normal host which does not forwards.
1577
1578 CONFIG_CDP_VERSION
1579
1580 An ascii string containing the version of the software.
1581
1582 CONFIG_CDP_PLATFORM
1583
1584 An ascii string containing the name of the platform.
1585
1586 CONFIG_CDP_TRIGGER
1587
1588 A 32bit integer sent on the trigger.
1589
1590 CONFIG_CDP_POWER_CONSUMPTION
1591
1592 A 16bit integer containing the power consumption of the
1593 device in .1 of milliwatts.
1594
1595 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1596
1597 A byte containing the id of the VLAN.
1598
1599 - Status LED: CONFIG_STATUS_LED
1600
1601 Several configurations allow to display the current
1602 status using a LED. For instance, the LED will blink
1603 fast while running U-Boot code, stop blinking as
1604 soon as a reply to a BOOTP request was received, and
1605 start blinking slow once the Linux kernel is running
1606 (supported by a status LED driver in the Linux
1607 kernel). Defining CONFIG_STATUS_LED enables this
1608 feature in U-Boot.
1609
1610 - CAN Support: CONFIG_CAN_DRIVER
1611
1612 Defining CONFIG_CAN_DRIVER enables CAN driver support
1613 on those systems that support this (optional)
1614 feature, like the TQM8xxL modules.
1615
1616 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1617
1618 These enable I2C serial bus commands. Defining either of
1619 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1620 include the appropriate I2C driver for the selected CPU.
1621
1622 This will allow you to use i2c commands at the u-boot
1623 command line (as long as you set CONFIG_CMD_I2C in
1624 CONFIG_COMMANDS) and communicate with i2c based realtime
1625 clock chips. See common/cmd_i2c.c for a description of the
1626 command line interface.
1627
1628 CONFIG_HARD_I2C selects a hardware I2C controller.
1629
1630 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1631 bit-banging) driver instead of CPM or similar hardware
1632 support for I2C.
1633
1634 There are several other quantities that must also be
1635 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1636
1637 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1638 to be the frequency (in Hz) at which you wish your i2c bus
1639 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1640 the CPU's i2c node address).
1641
1642 Now, the u-boot i2c code for the mpc8xx
1643 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1644 and so its address should therefore be cleared to 0 (See,
1645 eg, MPC823e User's Manual p.16-473). So, set
1646 CONFIG_SYS_I2C_SLAVE to 0.
1647
1648 CONFIG_SYS_I2C_INIT_MPC5XXX
1649
1650 When a board is reset during an i2c bus transfer
1651 chips might think that the current transfer is still
1652 in progress. Reset the slave devices by sending start
1653 commands until the slave device responds.
1654
1655 That's all that's required for CONFIG_HARD_I2C.
1656
1657 If you use the software i2c interface (CONFIG_SOFT_I2C)
1658 then the following macros need to be defined (examples are
1659 from include/configs/lwmon.h):
1660
1661 I2C_INIT
1662
1663 (Optional). Any commands necessary to enable the I2C
1664 controller or configure ports.
1665
1666 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1667
1668 I2C_PORT
1669
1670 (Only for MPC8260 CPU). The I/O port to use (the code
1671 assumes both bits are on the same port). Valid values
1672 are 0..3 for ports A..D.
1673
1674 I2C_ACTIVE
1675
1676 The code necessary to make the I2C data line active
1677 (driven). If the data line is open collector, this
1678 define can be null.
1679
1680 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1681
1682 I2C_TRISTATE
1683
1684 The code necessary to make the I2C data line tri-stated
1685 (inactive). If the data line is open collector, this
1686 define can be null.
1687
1688 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1689
1690 I2C_READ
1691
1692 Code that returns TRUE if the I2C data line is high,
1693 FALSE if it is low.
1694
1695 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1696
1697 I2C_SDA(bit)
1698
1699 If <bit> is TRUE, sets the I2C data line high. If it
1700 is FALSE, it clears it (low).
1701
1702 eg: #define I2C_SDA(bit) \
1703 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1704 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1705
1706 I2C_SCL(bit)
1707
1708 If <bit> is TRUE, sets the I2C clock line high. If it
1709 is FALSE, it clears it (low).
1710
1711 eg: #define I2C_SCL(bit) \
1712 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1713 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1714
1715 I2C_DELAY
1716
1717 This delay is invoked four times per clock cycle so this
1718 controls the rate of data transfer. The data rate thus
1719 is 1 / (I2C_DELAY * 4). Often defined to be something
1720 like:
1721
1722 #define I2C_DELAY udelay(2)
1723
1724 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1725
1726 If your arch supports the generic GPIO framework (asm/gpio.h),
1727 then you may alternatively define the two GPIOs that are to be
1728 used as SCL / SDA. Any of the previous I2C_xxx macros will
1729 have GPIO-based defaults assigned to them as appropriate.
1730
1731 You should define these to the GPIO value as given directly to
1732 the generic GPIO functions.
1733
1734 CONFIG_SYS_I2C_INIT_BOARD
1735
1736 When a board is reset during an i2c bus transfer
1737 chips might think that the current transfer is still
1738 in progress. On some boards it is possible to access
1739 the i2c SCLK line directly, either by using the
1740 processor pin as a GPIO or by having a second pin
1741 connected to the bus. If this option is defined a
1742 custom i2c_init_board() routine in boards/xxx/board.c
1743 is run early in the boot sequence.
1744
1745 CONFIG_SYS_I2C_BOARD_LATE_INIT
1746
1747 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1748 defined a custom i2c_board_late_init() routine in
1749 boards/xxx/board.c is run AFTER the operations in i2c_init()
1750 is completed. This callpoint can be used to unreset i2c bus
1751 using CPU i2c controller register accesses for CPUs whose i2c
1752 controller provide such a method. It is called at the end of
1753 i2c_init() to allow i2c_init operations to setup the i2c bus
1754 controller on the CPU (e.g. setting bus speed & slave address).
1755
1756 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1757
1758 This option enables configuration of bi_iic_fast[] flags
1759 in u-boot bd_info structure based on u-boot environment
1760 variable "i2cfast". (see also i2cfast)
1761
1762 CONFIG_I2C_MULTI_BUS
1763
1764 This option allows the use of multiple I2C buses, each of which
1765 must have a controller. At any point in time, only one bus is
1766 active. To switch to a different bus, use the 'i2c dev' command.
1767 Note that bus numbering is zero-based.
1768
1769 CONFIG_SYS_I2C_NOPROBES
1770
1771 This option specifies a list of I2C devices that will be skipped
1772 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1773 is set, specify a list of bus-device pairs. Otherwise, specify
1774 a 1D array of device addresses
1775
1776 e.g.
1777 #undef CONFIG_I2C_MULTI_BUS
1778 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1779
1780 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1781
1782 #define CONFIG_I2C_MULTI_BUS
1783 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1784
1785 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1786
1787 CONFIG_SYS_SPD_BUS_NUM
1788
1789 If defined, then this indicates the I2C bus number for DDR SPD.
1790 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1791
1792 CONFIG_SYS_RTC_BUS_NUM
1793
1794 If defined, then this indicates the I2C bus number for the RTC.
1795 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1796
1797 CONFIG_SYS_DTT_BUS_NUM
1798
1799 If defined, then this indicates the I2C bus number for the DTT.
1800 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1801
1802 CONFIG_SYS_I2C_DTT_ADDR:
1803
1804 If defined, specifies the I2C address of the DTT device.
1805 If not defined, then U-Boot uses predefined value for
1806 specified DTT device.
1807
1808 CONFIG_FSL_I2C
1809
1810 Define this option if you want to use Freescale's I2C driver in
1811 drivers/i2c/fsl_i2c.c.
1812
1813 CONFIG_I2C_MUX
1814
1815 Define this option if you have I2C devices reached over 1 .. n
1816 I2C Muxes like the pca9544a. This option addes a new I2C
1817 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1818 new I2C Bus to the existing I2C Busses. If you select the
1819 new Bus with "i2c dev", u-bbot sends first the commandos for
1820 the muxes to activate this new "bus".
1821
1822 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1823 feature!
1824
1825 Example:
1826 Adding a new I2C Bus reached over 2 pca9544a muxes
1827 The First mux with address 70 and channel 6
1828 The Second mux with address 71 and channel 4
1829
1830 => i2c bus pca9544a:70:6:pca9544a:71:4
1831
1832 Use the "i2c bus" command without parameter, to get a list
1833 of I2C Busses with muxes:
1834
1835 => i2c bus
1836 Busses reached over muxes:
1837 Bus ID: 2
1838 reached over Mux(es):
1839 pca9544a@70 ch: 4
1840 Bus ID: 3
1841 reached over Mux(es):
1842 pca9544a@70 ch: 6
1843 pca9544a@71 ch: 4
1844 =>
1845
1846 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1847 u-boot first sends the command to the mux@70 to enable
1848 channel 6, and then the command to the mux@71 to enable
1849 the channel 4.
1850
1851 After that, you can use the "normal" i2c commands as
1852 usual to communicate with your I2C devices behind
1853 the 2 muxes.
1854
1855 This option is actually implemented for the bitbanging
1856 algorithm in common/soft_i2c.c and for the Hardware I2C
1857 Bus on the MPC8260. But it should be not so difficult
1858 to add this option to other architectures.
1859
1860 CONFIG_SOFT_I2C_READ_REPEATED_START
1861
1862 defining this will force the i2c_read() function in
1863 the soft_i2c driver to perform an I2C repeated start
1864 between writing the address pointer and reading the
1865 data. If this define is omitted the default behaviour
1866 of doing a stop-start sequence will be used. Most I2C
1867 devices can use either method, but some require one or
1868 the other.
1869
1870 - SPI Support: CONFIG_SPI
1871
1872 Enables SPI driver (so far only tested with
1873 SPI EEPROM, also an instance works with Crystal A/D and
1874 D/As on the SACSng board)
1875
1876 CONFIG_SH_SPI
1877
1878 Enables the driver for SPI controller on SuperH. Currently
1879 only SH7757 is supported.
1880
1881 CONFIG_SPI_X
1882
1883 Enables extended (16-bit) SPI EEPROM addressing.
1884 (symmetrical to CONFIG_I2C_X)
1885
1886 CONFIG_SOFT_SPI
1887
1888 Enables a software (bit-bang) SPI driver rather than
1889 using hardware support. This is a general purpose
1890 driver that only requires three general I/O port pins
1891 (two outputs, one input) to function. If this is
1892 defined, the board configuration must define several
1893 SPI configuration items (port pins to use, etc). For
1894 an example, see include/configs/sacsng.h.
1895
1896 CONFIG_HARD_SPI
1897
1898 Enables a hardware SPI driver for general-purpose reads
1899 and writes. As with CONFIG_SOFT_SPI, the board configuration
1900 must define a list of chip-select function pointers.
1901 Currently supported on some MPC8xxx processors. For an
1902 example, see include/configs/mpc8349emds.h.
1903
1904 CONFIG_MXC_SPI
1905
1906 Enables the driver for the SPI controllers on i.MX and MXC
1907 SoCs. Currently i.MX31/35/51 are supported.
1908
1909 - FPGA Support: CONFIG_FPGA
1910
1911 Enables FPGA subsystem.
1912
1913 CONFIG_FPGA_<vendor>
1914
1915 Enables support for specific chip vendors.
1916 (ALTERA, XILINX)
1917
1918 CONFIG_FPGA_<family>
1919
1920 Enables support for FPGA family.
1921 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1922
1923 CONFIG_FPGA_COUNT
1924
1925 Specify the number of FPGA devices to support.
1926
1927 CONFIG_SYS_FPGA_PROG_FEEDBACK
1928
1929 Enable printing of hash marks during FPGA configuration.
1930
1931 CONFIG_SYS_FPGA_CHECK_BUSY
1932
1933 Enable checks on FPGA configuration interface busy
1934 status by the configuration function. This option
1935 will require a board or device specific function to
1936 be written.
1937
1938 CONFIG_FPGA_DELAY
1939
1940 If defined, a function that provides delays in the FPGA
1941 configuration driver.
1942
1943 CONFIG_SYS_FPGA_CHECK_CTRLC
1944 Allow Control-C to interrupt FPGA configuration
1945
1946 CONFIG_SYS_FPGA_CHECK_ERROR
1947
1948 Check for configuration errors during FPGA bitfile
1949 loading. For example, abort during Virtex II
1950 configuration if the INIT_B line goes low (which
1951 indicated a CRC error).
1952
1953 CONFIG_SYS_FPGA_WAIT_INIT
1954
1955 Maximum time to wait for the INIT_B line to deassert
1956 after PROB_B has been deasserted during a Virtex II
1957 FPGA configuration sequence. The default time is 500
1958 ms.
1959
1960 CONFIG_SYS_FPGA_WAIT_BUSY
1961
1962 Maximum time to wait for BUSY to deassert during
1963 Virtex II FPGA configuration. The default is 5 ms.
1964
1965 CONFIG_SYS_FPGA_WAIT_CONFIG
1966
1967 Time to wait after FPGA configuration. The default is
1968 200 ms.
1969
1970 - Configuration Management:
1971 CONFIG_IDENT_STRING
1972
1973 If defined, this string will be added to the U-Boot
1974 version information (U_BOOT_VERSION)
1975
1976 - Vendor Parameter Protection:
1977
1978 U-Boot considers the values of the environment
1979 variables "serial#" (Board Serial Number) and
1980 "ethaddr" (Ethernet Address) to be parameters that
1981 are set once by the board vendor / manufacturer, and
1982 protects these variables from casual modification by
1983 the user. Once set, these variables are read-only,
1984 and write or delete attempts are rejected. You can
1985 change this behaviour:
1986
1987 If CONFIG_ENV_OVERWRITE is #defined in your config
1988 file, the write protection for vendor parameters is
1989 completely disabled. Anybody can change or delete
1990 these parameters.
1991
1992 Alternatively, if you #define _both_ CONFIG_ETHADDR
1993 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1994 Ethernet address is installed in the environment,
1995 which can be changed exactly ONCE by the user. [The
1996 serial# is unaffected by this, i. e. it remains
1997 read-only.]
1998
1999 - Protected RAM:
2000 CONFIG_PRAM
2001
2002 Define this variable to enable the reservation of
2003 "protected RAM", i. e. RAM which is not overwritten
2004 by U-Boot. Define CONFIG_PRAM to hold the number of
2005 kB you want to reserve for pRAM. You can overwrite
2006 this default value by defining an environment
2007 variable "pram" to the number of kB you want to
2008 reserve. Note that the board info structure will
2009 still show the full amount of RAM. If pRAM is
2010 reserved, a new environment variable "mem" will
2011 automatically be defined to hold the amount of
2012 remaining RAM in a form that can be passed as boot
2013 argument to Linux, for instance like that:
2014
2015 setenv bootargs ... mem=\${mem}
2016 saveenv
2017
2018 This way you can tell Linux not to use this memory,
2019 either, which results in a memory region that will
2020 not be affected by reboots.
2021
2022 *WARNING* If your board configuration uses automatic
2023 detection of the RAM size, you must make sure that
2024 this memory test is non-destructive. So far, the
2025 following board configurations are known to be
2026 "pRAM-clean":
2027
2028 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
2029 HERMES, IP860, RPXlite, LWMON, LANTEC,
2030 FLAGADM, TQM8260
2031
2032 - Error Recovery:
2033 CONFIG_PANIC_HANG
2034
2035 Define this variable to stop the system in case of a
2036 fatal error, so that you have to reset it manually.
2037 This is probably NOT a good idea for an embedded
2038 system where you want the system to reboot
2039 automatically as fast as possible, but it may be
2040 useful during development since you can try to debug
2041 the conditions that lead to the situation.
2042
2043 CONFIG_NET_RETRY_COUNT
2044
2045 This variable defines the number of retries for
2046 network operations like ARP, RARP, TFTP, or BOOTP
2047 before giving up the operation. If not defined, a
2048 default value of 5 is used.
2049
2050 CONFIG_ARP_TIMEOUT
2051
2052 Timeout waiting for an ARP reply in milliseconds.
2053
2054 - Command Interpreter:
2055 CONFIG_AUTO_COMPLETE
2056
2057 Enable auto completion of commands using TAB.
2058
2059 Note that this feature has NOT been implemented yet
2060 for the "hush" shell.
2061
2062
2063 CONFIG_SYS_HUSH_PARSER
2064
2065 Define this variable to enable the "hush" shell (from
2066 Busybox) as command line interpreter, thus enabling
2067 powerful command line syntax like
2068 if...then...else...fi conditionals or `&&' and '||'
2069 constructs ("shell scripts").
2070
2071 If undefined, you get the old, much simpler behaviour
2072 with a somewhat smaller memory footprint.
2073
2074
2075 CONFIG_SYS_PROMPT_HUSH_PS2
2076
2077 This defines the secondary prompt string, which is
2078 printed when the command interpreter needs more input
2079 to complete a command. Usually "> ".
2080
2081 Note:
2082
2083 In the current implementation, the local variables
2084 space and global environment variables space are
2085 separated. Local variables are those you define by
2086 simply typing `name=value'. To access a local
2087 variable later on, you have write `$name' or
2088 `${name}'; to execute the contents of a variable
2089 directly type `$name' at the command prompt.
2090
2091 Global environment variables are those you use
2092 setenv/printenv to work with. To run a command stored
2093 in such a variable, you need to use the run command,
2094 and you must not use the '$' sign to access them.
2095
2096 To store commands and special characters in a
2097 variable, please use double quotation marks
2098 surrounding the whole text of the variable, instead
2099 of the backslashes before semicolons and special
2100 symbols.
2101
2102 - Commandline Editing and History:
2103 CONFIG_CMDLINE_EDITING
2104
2105 Enable editing and History functions for interactive
2106 commandline input operations
2107
2108 - Default Environment:
2109 CONFIG_EXTRA_ENV_SETTINGS
2110
2111 Define this to contain any number of null terminated
2112 strings (variable = value pairs) that will be part of
2113 the default environment compiled into the boot image.
2114
2115 For example, place something like this in your
2116 board's config file:
2117
2118 #define CONFIG_EXTRA_ENV_SETTINGS \
2119 "myvar1=value1\0" \
2120 "myvar2=value2\0"
2121
2122 Warning: This method is based on knowledge about the
2123 internal format how the environment is stored by the
2124 U-Boot code. This is NOT an official, exported
2125 interface! Although it is unlikely that this format
2126 will change soon, there is no guarantee either.
2127 You better know what you are doing here.
2128
2129 Note: overly (ab)use of the default environment is
2130 discouraged. Make sure to check other ways to preset
2131 the environment like the "source" command or the
2132 boot command first.
2133
2134 - DataFlash Support:
2135 CONFIG_HAS_DATAFLASH
2136
2137 Defining this option enables DataFlash features and
2138 allows to read/write in Dataflash via the standard
2139 commands cp, md...
2140
2141 - SystemACE Support:
2142 CONFIG_SYSTEMACE
2143
2144 Adding this option adds support for Xilinx SystemACE
2145 chips attached via some sort of local bus. The address
2146 of the chip must also be defined in the
2147 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2148
2149 #define CONFIG_SYSTEMACE
2150 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2151
2152 When SystemACE support is added, the "ace" device type
2153 becomes available to the fat commands, i.e. fatls.
2154
2155 - TFTP Fixed UDP Port:
2156 CONFIG_TFTP_PORT
2157
2158 If this is defined, the environment variable tftpsrcp
2159 is used to supply the TFTP UDP source port value.
2160 If tftpsrcp isn't defined, the normal pseudo-random port
2161 number generator is used.
2162
2163 Also, the environment variable tftpdstp is used to supply
2164 the TFTP UDP destination port value. If tftpdstp isn't
2165 defined, the normal port 69 is used.
2166
2167 The purpose for tftpsrcp is to allow a TFTP server to
2168 blindly start the TFTP transfer using the pre-configured
2169 target IP address and UDP port. This has the effect of
2170 "punching through" the (Windows XP) firewall, allowing
2171 the remainder of the TFTP transfer to proceed normally.
2172 A better solution is to properly configure the firewall,
2173 but sometimes that is not allowed.
2174
2175 - Show boot progress:
2176 CONFIG_SHOW_BOOT_PROGRESS
2177
2178 Defining this option allows to add some board-
2179 specific code (calling a user-provided function
2180 "show_boot_progress(int)") that enables you to show
2181 the system's boot progress on some display (for
2182 example, some LED's) on your board. At the moment,
2183 the following checkpoints are implemented:
2184
2185 Legacy uImage format:
2186
2187 Arg Where When
2188 1 common/cmd_bootm.c before attempting to boot an image
2189 -1 common/cmd_bootm.c Image header has bad magic number
2190 2 common/cmd_bootm.c Image header has correct magic number
2191 -2 common/cmd_bootm.c Image header has bad checksum
2192 3 common/cmd_bootm.c Image header has correct checksum
2193 -3 common/cmd_bootm.c Image data has bad checksum
2194 4 common/cmd_bootm.c Image data has correct checksum
2195 -4 common/cmd_bootm.c Image is for unsupported architecture
2196 5 common/cmd_bootm.c Architecture check OK
2197 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2198 6 common/cmd_bootm.c Image Type check OK
2199 -6 common/cmd_bootm.c gunzip uncompression error
2200 -7 common/cmd_bootm.c Unimplemented compression type
2201 7 common/cmd_bootm.c Uncompression OK
2202 8 common/cmd_bootm.c No uncompress/copy overwrite error
2203 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2204
2205 9 common/image.c Start initial ramdisk verification
2206 -10 common/image.c Ramdisk header has bad magic number
2207 -11 common/image.c Ramdisk header has bad checksum
2208 10 common/image.c Ramdisk header is OK
2209 -12 common/image.c Ramdisk data has bad checksum
2210 11 common/image.c Ramdisk data has correct checksum
2211 12 common/image.c Ramdisk verification complete, start loading
2212 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2213 13 common/image.c Start multifile image verification
2214 14 common/image.c No initial ramdisk, no multifile, continue.
2215
2216 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2217
2218 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2219 -31 post/post.c POST test failed, detected by post_output_backlog()
2220 -32 post/post.c POST test failed, detected by post_run_single()
2221
2222 34 common/cmd_doc.c before loading a Image from a DOC device
2223 -35 common/cmd_doc.c Bad usage of "doc" command
2224 35 common/cmd_doc.c correct usage of "doc" command
2225 -36 common/cmd_doc.c No boot device
2226 36 common/cmd_doc.c correct boot device
2227 -37 common/cmd_doc.c Unknown Chip ID on boot device
2228 37 common/cmd_doc.c correct chip ID found, device available
2229 -38 common/cmd_doc.c Read Error on boot device
2230 38 common/cmd_doc.c reading Image header from DOC device OK
2231 -39 common/cmd_doc.c Image header has bad magic number
2232 39 common/cmd_doc.c Image header has correct magic number
2233 -40 common/cmd_doc.c Error reading Image from DOC device
2234 40 common/cmd_doc.c Image header has correct magic number
2235 41 common/cmd_ide.c before loading a Image from a IDE device
2236 -42 common/cmd_ide.c Bad usage of "ide" command
2237 42 common/cmd_ide.c correct usage of "ide" command
2238 -43 common/cmd_ide.c No boot device
2239 43 common/cmd_ide.c boot device found
2240 -44 common/cmd_ide.c Device not available
2241 44 common/cmd_ide.c Device available
2242 -45 common/cmd_ide.c wrong partition selected
2243 45 common/cmd_ide.c partition selected
2244 -46 common/cmd_ide.c Unknown partition table
2245 46 common/cmd_ide.c valid partition table found
2246 -47 common/cmd_ide.c Invalid partition type
2247 47 common/cmd_ide.c correct partition type
2248 -48 common/cmd_ide.c Error reading Image Header on boot device
2249 48 common/cmd_ide.c reading Image Header from IDE device OK
2250 -49 common/cmd_ide.c Image header has bad magic number
2251 49 common/cmd_ide.c Image header has correct magic number
2252 -50 common/cmd_ide.c Image header has bad checksum
2253 50 common/cmd_ide.c Image header has correct checksum
2254 -51 common/cmd_ide.c Error reading Image from IDE device
2255 51 common/cmd_ide.c reading Image from IDE device OK
2256 52 common/cmd_nand.c before loading a Image from a NAND device
2257 -53 common/cmd_nand.c Bad usage of "nand" command
2258 53 common/cmd_nand.c correct usage of "nand" command
2259 -54 common/cmd_nand.c No boot device
2260 54 common/cmd_nand.c boot device found
2261 -55 common/cmd_nand.c Unknown Chip ID on boot device
2262 55 common/cmd_nand.c correct chip ID found, device available
2263 -56 common/cmd_nand.c Error reading Image Header on boot device
2264 56 common/cmd_nand.c reading Image Header from NAND device OK
2265 -57 common/cmd_nand.c Image header has bad magic number
2266 57 common/cmd_nand.c Image header has correct magic number
2267 -58 common/cmd_nand.c Error reading Image from NAND device
2268 58 common/cmd_nand.c reading Image from NAND device OK
2269
2270 -60 common/env_common.c Environment has a bad CRC, using default
2271
2272 64 net/eth.c starting with Ethernet configuration.
2273 -64 net/eth.c no Ethernet found.
2274 65 net/eth.c Ethernet found.
2275
2276 -80 common/cmd_net.c usage wrong
2277 80 common/cmd_net.c before calling NetLoop()
2278 -81 common/cmd_net.c some error in NetLoop() occurred
2279 81 common/cmd_net.c NetLoop() back without error
2280 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2281 82 common/cmd_net.c trying automatic boot
2282 83 common/cmd_net.c running "source" command
2283 -83 common/cmd_net.c some error in automatic boot or "source" command
2284 84 common/cmd_net.c end without errors
2285
2286 FIT uImage format:
2287
2288 Arg Where When
2289 100 common/cmd_bootm.c Kernel FIT Image has correct format
2290 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2291 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2292 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2293 102 common/cmd_bootm.c Kernel unit name specified
2294 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2295 103 common/cmd_bootm.c Found configuration node
2296 104 common/cmd_bootm.c Got kernel subimage node offset
2297 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2298 105 common/cmd_bootm.c Kernel subimage hash verification OK
2299 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2300 106 common/cmd_bootm.c Architecture check OK
2301 -106 common/cmd_bootm.c Kernel subimage has wrong type
2302 107 common/cmd_bootm.c Kernel subimage type OK
2303 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2304 108 common/cmd_bootm.c Got kernel subimage data/size
2305 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2306 -109 common/cmd_bootm.c Can't get kernel subimage type
2307 -110 common/cmd_bootm.c Can't get kernel subimage comp
2308 -111 common/cmd_bootm.c Can't get kernel subimage os
2309 -112 common/cmd_bootm.c Can't get kernel subimage load address
2310 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2311
2312 120 common/image.c Start initial ramdisk verification
2313 -120 common/image.c Ramdisk FIT image has incorrect format
2314 121 common/image.c Ramdisk FIT image has correct format
2315 122 common/image.c No ramdisk subimage unit name, using configuration
2316 -122 common/image.c Can't get configuration for ramdisk subimage
2317 123 common/image.c Ramdisk unit name specified
2318 -124 common/image.c Can't get ramdisk subimage node offset
2319 125 common/image.c Got ramdisk subimage node offset
2320 -125 common/image.c Ramdisk subimage hash verification failed
2321 126 common/image.c Ramdisk subimage hash verification OK
2322 -126 common/image.c Ramdisk subimage for unsupported architecture
2323 127 common/image.c Architecture check OK
2324 -127 common/image.c Can't get ramdisk subimage data/size
2325 128 common/image.c Got ramdisk subimage data/size
2326 129 common/image.c Can't get ramdisk load address
2327 -129 common/image.c Got ramdisk load address
2328
2329 -130 common/cmd_doc.c Incorrect FIT image format
2330 131 common/cmd_doc.c FIT image format OK
2331
2332 -140 common/cmd_ide.c Incorrect FIT image format
2333 141 common/cmd_ide.c FIT image format OK
2334
2335 -150 common/cmd_nand.c Incorrect FIT image format
2336 151 common/cmd_nand.c FIT image format OK
2337
2338 - Standalone program support:
2339 CONFIG_STANDALONE_LOAD_ADDR
2340
2341 This option defines a board specific value for the
2342 address where standalone program gets loaded, thus
2343 overwriting the architecture dependent default
2344 settings.
2345
2346 - Frame Buffer Address:
2347 CONFIG_FB_ADDR
2348
2349 Define CONFIG_FB_ADDR if you want to use specific
2350 address for frame buffer.
2351 Then system will reserve the frame buffer address to
2352 defined address instead of lcd_setmem (this function
2353 grabs the memory for frame buffer by panel's size).
2354
2355 Please see board_init_f function.
2356
2357 - Automatic software updates via TFTP server
2358 CONFIG_UPDATE_TFTP
2359 CONFIG_UPDATE_TFTP_CNT_MAX
2360 CONFIG_UPDATE_TFTP_MSEC_MAX
2361
2362 These options enable and control the auto-update feature;
2363 for a more detailed description refer to doc/README.update.
2364
2365 - MTD Support (mtdparts command, UBI support)
2366 CONFIG_MTD_DEVICE
2367
2368 Adds the MTD device infrastructure from the Linux kernel.
2369 Needed for mtdparts command support.
2370
2371 CONFIG_MTD_PARTITIONS
2372
2373 Adds the MTD partitioning infrastructure from the Linux
2374 kernel. Needed for UBI support.
2375
2376 - SPL framework
2377 CONFIG_SPL
2378 Enable building of SPL globally.
2379
2380 CONFIG_SPL_TEXT_BASE
2381 TEXT_BASE for linking the SPL binary.
2382
2383 CONFIG_SPL_LDSCRIPT
2384 LDSCRIPT for linking the SPL binary.
2385
2386 CONFIG_SPL_LIBCOMMON_SUPPORT
2387 Support for common/libcommon.o in SPL binary
2388
2389 CONFIG_SPL_LIBDISK_SUPPORT
2390 Support for disk/libdisk.o in SPL binary
2391
2392 CONFIG_SPL_I2C_SUPPORT
2393 Support for drivers/i2c/libi2c.o in SPL binary
2394
2395 CONFIG_SPL_GPIO_SUPPORT
2396 Support for drivers/gpio/libgpio.o in SPL binary
2397
2398 CONFIG_SPL_MMC_SUPPORT
2399 Support for drivers/mmc/libmmc.o in SPL binary
2400
2401 CONFIG_SPL_SERIAL_SUPPORT
2402 Support for drivers/serial/libserial.o in SPL binary
2403
2404 CONFIG_SPL_SPI_FLASH_SUPPORT
2405 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2406
2407 CONFIG_SPL_SPI_SUPPORT
2408 Support for drivers/spi/libspi.o in SPL binary
2409
2410 CONFIG_SPL_FAT_SUPPORT
2411 Support for fs/fat/libfat.o in SPL binary
2412
2413 CONFIG_SPL_LIBGENERIC_SUPPORT
2414 Support for lib/libgeneric.o in SPL binary
2415
2416 Modem Support:
2417 --------------
2418
2419 [so far only for SMDK2400 boards]
2420
2421 - Modem support enable:
2422 CONFIG_MODEM_SUPPORT
2423
2424 - RTS/CTS Flow control enable:
2425 CONFIG_HWFLOW
2426
2427 - Modem debug support:
2428 CONFIG_MODEM_SUPPORT_DEBUG
2429
2430 Enables debugging stuff (char screen[1024], dbg())
2431 for modem support. Useful only with BDI2000.
2432
2433 - Interrupt support (PPC):
2434
2435 There are common interrupt_init() and timer_interrupt()
2436 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2437 for CPU specific initialization. interrupt_init_cpu()
2438 should set decrementer_count to appropriate value. If
2439 CPU resets decrementer automatically after interrupt
2440 (ppc4xx) it should set decrementer_count to zero.
2441 timer_interrupt() calls timer_interrupt_cpu() for CPU
2442 specific handling. If board has watchdog / status_led
2443 / other_activity_monitor it works automatically from
2444 general timer_interrupt().
2445
2446 - General:
2447
2448 In the target system modem support is enabled when a
2449 specific key (key combination) is pressed during
2450 power-on. Otherwise U-Boot will boot normally
2451 (autoboot). The key_pressed() function is called from
2452 board_init(). Currently key_pressed() is a dummy
2453 function, returning 1 and thus enabling modem
2454 initialization.
2455
2456 If there are no modem init strings in the
2457 environment, U-Boot proceed to autoboot; the
2458 previous output (banner, info printfs) will be
2459 suppressed, though.
2460
2461 See also: doc/README.Modem
2462
2463 Board initialization settings:
2464 ------------------------------
2465
2466 During Initialization u-boot calls a number of board specific functions
2467 to allow the preparation of board specific prerequisites, e.g. pin setup
2468 before drivers are initialized. To enable these callbacks the
2469 following configuration macros have to be defined. Currently this is
2470 architecture specific, so please check arch/your_architecture/lib/board.c
2471 typically in board_init_f() and board_init_r().
2472
2473 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2474 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2475 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2476 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2477
2478 Configuration Settings:
2479 -----------------------
2480
2481 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2482 undefine this when you're short of memory.
2483
2484 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2485 width of the commands listed in the 'help' command output.
2486
2487 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2488 prompt for user input.
2489
2490 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2491
2492 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2493
2494 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2495
2496 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2497 the application (usually a Linux kernel) when it is
2498 booted
2499
2500 - CONFIG_SYS_BAUDRATE_TABLE:
2501 List of legal baudrate settings for this board.
2502
2503 - CONFIG_SYS_CONSOLE_INFO_QUIET
2504 Suppress display of console information at boot.
2505
2506 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2507 If the board specific function
2508 extern int overwrite_console (void);
2509 returns 1, the stdin, stderr and stdout are switched to the
2510 serial port, else the settings in the environment are used.
2511
2512 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2513 Enable the call to overwrite_console().
2514
2515 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2516 Enable overwrite of previous console environment settings.
2517
2518 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2519 Begin and End addresses of the area used by the
2520 simple memory test.
2521
2522 - CONFIG_SYS_ALT_MEMTEST:
2523 Enable an alternate, more extensive memory test.
2524
2525 - CONFIG_SYS_MEMTEST_SCRATCH:
2526 Scratch address used by the alternate memory test
2527 You only need to set this if address zero isn't writeable
2528
2529 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2530 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2531 this specified memory area will get subtracted from the top
2532 (end) of RAM and won't get "touched" at all by U-Boot. By
2533 fixing up gd->ram_size the Linux kernel should gets passed
2534 the now "corrected" memory size and won't touch it either.
2535 This should work for arch/ppc and arch/powerpc. Only Linux
2536 board ports in arch/powerpc with bootwrapper support that
2537 recalculate the memory size from the SDRAM controller setup
2538 will have to get fixed in Linux additionally.
2539
2540 This option can be used as a workaround for the 440EPx/GRx
2541 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2542 be touched.
2543
2544 WARNING: Please make sure that this value is a multiple of
2545 the Linux page size (normally 4k). If this is not the case,
2546 then the end address of the Linux memory will be located at a
2547 non page size aligned address and this could cause major
2548 problems.
2549
2550 - CONFIG_SYS_TFTP_LOADADDR:
2551 Default load address for network file downloads
2552
2553 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2554 Enable temporary baudrate change while serial download
2555
2556 - CONFIG_SYS_SDRAM_BASE:
2557 Physical start address of SDRAM. _Must_ be 0 here.
2558
2559 - CONFIG_SYS_MBIO_BASE:
2560 Physical start address of Motherboard I/O (if using a
2561 Cogent motherboard)
2562
2563 - CONFIG_SYS_FLASH_BASE:
2564 Physical start address of Flash memory.
2565
2566 - CONFIG_SYS_MONITOR_BASE:
2567 Physical start address of boot monitor code (set by
2568 make config files to be same as the text base address
2569 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2570 CONFIG_SYS_FLASH_BASE when booting from flash.
2571
2572 - CONFIG_SYS_MONITOR_LEN:
2573 Size of memory reserved for monitor code, used to
2574 determine _at_compile_time_ (!) if the environment is
2575 embedded within the U-Boot image, or in a separate
2576 flash sector.
2577
2578 - CONFIG_SYS_MALLOC_LEN:
2579 Size of DRAM reserved for malloc() use.
2580
2581 - CONFIG_SYS_BOOTM_LEN:
2582 Normally compressed uImages are limited to an
2583 uncompressed size of 8 MBytes. If this is not enough,
2584 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2585 to adjust this setting to your needs.
2586
2587 - CONFIG_SYS_BOOTMAPSZ:
2588 Maximum size of memory mapped by the startup code of
2589 the Linux kernel; all data that must be processed by
2590 the Linux kernel (bd_info, boot arguments, FDT blob if
2591 used) must be put below this limit, unless "bootm_low"
2592 enviroment variable is defined and non-zero. In such case
2593 all data for the Linux kernel must be between "bootm_low"
2594 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2595 variable "bootm_mapsize" will override the value of
2596 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2597 then the value in "bootm_size" will be used instead.
2598
2599 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2600 Enable initrd_high functionality. If defined then the
2601 initrd_high feature is enabled and the bootm ramdisk subcommand
2602 is enabled.
2603
2604 - CONFIG_SYS_BOOT_GET_CMDLINE:
2605 Enables allocating and saving kernel cmdline in space between
2606 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2607
2608 - CONFIG_SYS_BOOT_GET_KBD:
2609 Enables allocating and saving a kernel copy of the bd_info in
2610 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2611
2612 - CONFIG_SYS_MAX_FLASH_BANKS:
2613 Max number of Flash memory banks
2614
2615 - CONFIG_SYS_MAX_FLASH_SECT:
2616 Max number of sectors on a Flash chip
2617
2618 - CONFIG_SYS_FLASH_ERASE_TOUT:
2619 Timeout for Flash erase operations (in ms)
2620
2621 - CONFIG_SYS_FLASH_WRITE_TOUT:
2622 Timeout for Flash write operations (in ms)
2623
2624 - CONFIG_SYS_FLASH_LOCK_TOUT
2625 Timeout for Flash set sector lock bit operation (in ms)
2626
2627 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2628 Timeout for Flash clear lock bits operation (in ms)
2629
2630 - CONFIG_SYS_FLASH_PROTECTION
2631 If defined, hardware flash sectors protection is used
2632 instead of U-Boot software protection.
2633
2634 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2635
2636 Enable TFTP transfers directly to flash memory;
2637 without this option such a download has to be
2638 performed in two steps: (1) download to RAM, and (2)
2639 copy from RAM to flash.
2640
2641 The two-step approach is usually more reliable, since
2642 you can check if the download worked before you erase
2643 the flash, but in some situations (when system RAM is
2644 too limited to allow for a temporary copy of the
2645 downloaded image) this option may be very useful.
2646
2647 - CONFIG_SYS_FLASH_CFI:
2648 Define if the flash driver uses extra elements in the
2649 common flash structure for storing flash geometry.
2650
2651 - CONFIG_FLASH_CFI_DRIVER
2652 This option also enables the building of the cfi_flash driver
2653 in the drivers directory
2654
2655 - CONFIG_FLASH_CFI_MTD
2656 This option enables the building of the cfi_mtd driver
2657 in the drivers directory. The driver exports CFI flash
2658 to the MTD layer.
2659
2660 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2661 Use buffered writes to flash.
2662
2663 - CONFIG_FLASH_SPANSION_S29WS_N
2664 s29ws-n MirrorBit flash has non-standard addresses for buffered
2665 write commands.
2666
2667 - CONFIG_SYS_FLASH_QUIET_TEST
2668 If this option is defined, the common CFI flash doesn't
2669 print it's warning upon not recognized FLASH banks. This
2670 is useful, if some of the configured banks are only
2671 optionally available.
2672
2673 - CONFIG_FLASH_SHOW_PROGRESS
2674 If defined (must be an integer), print out countdown
2675 digits and dots. Recommended value: 45 (9..1) for 80
2676 column displays, 15 (3..1) for 40 column displays.
2677
2678 - CONFIG_SYS_RX_ETH_BUFFER:
2679 Defines the number of Ethernet receive buffers. On some
2680 Ethernet controllers it is recommended to set this value
2681 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2682 buffers can be full shortly after enabling the interface
2683 on high Ethernet traffic.
2684 Defaults to 4 if not defined.
2685
2686 - CONFIG_ENV_MAX_ENTRIES
2687
2688 Maximum number of entries in the hash table that is used
2689 internally to store the environment settings. The default
2690 setting is supposed to be generous and should work in most
2691 cases. This setting can be used to tune behaviour; see
2692 lib/hashtable.c for details.
2693
2694 The following definitions that deal with the placement and management
2695 of environment data (variable area); in general, we support the
2696 following configurations:
2697
2698 - CONFIG_BUILD_ENVCRC:
2699
2700 Builds up envcrc with the target environment so that external utils
2701 may easily extract it and embed it in final U-Boot images.
2702
2703 - CONFIG_ENV_IS_IN_FLASH:
2704
2705 Define this if the environment is in flash memory.
2706
2707 a) The environment occupies one whole flash sector, which is
2708 "embedded" in the text segment with the U-Boot code. This
2709 happens usually with "bottom boot sector" or "top boot
2710 sector" type flash chips, which have several smaller
2711 sectors at the start or the end. For instance, such a
2712 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2713 such a case you would place the environment in one of the
2714 4 kB sectors - with U-Boot code before and after it. With
2715 "top boot sector" type flash chips, you would put the
2716 environment in one of the last sectors, leaving a gap
2717 between U-Boot and the environment.
2718
2719 - CONFIG_ENV_OFFSET:
2720
2721 Offset of environment data (variable area) to the
2722 beginning of flash memory; for instance, with bottom boot
2723 type flash chips the second sector can be used: the offset
2724 for this sector is given here.
2725
2726 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2727
2728 - CONFIG_ENV_ADDR:
2729
2730 This is just another way to specify the start address of
2731 the flash sector containing the environment (instead of
2732 CONFIG_ENV_OFFSET).
2733
2734 - CONFIG_ENV_SECT_SIZE:
2735
2736 Size of the sector containing the environment.
2737
2738
2739 b) Sometimes flash chips have few, equal sized, BIG sectors.
2740 In such a case you don't want to spend a whole sector for
2741 the environment.
2742
2743 - CONFIG_ENV_SIZE:
2744
2745 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2746 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2747 of this flash sector for the environment. This saves
2748 memory for the RAM copy of the environment.
2749
2750 It may also save flash memory if you decide to use this
2751 when your environment is "embedded" within U-Boot code,
2752 since then the remainder of the flash sector could be used
2753 for U-Boot code. It should be pointed out that this is
2754 STRONGLY DISCOURAGED from a robustness point of view:
2755 updating the environment in flash makes it always
2756 necessary to erase the WHOLE sector. If something goes
2757 wrong before the contents has been restored from a copy in
2758 RAM, your target system will be dead.
2759
2760 - CONFIG_ENV_ADDR_REDUND
2761 CONFIG_ENV_SIZE_REDUND
2762
2763 These settings describe a second storage area used to hold
2764 a redundant copy of the environment data, so that there is
2765 a valid backup copy in case there is a power failure during
2766 a "saveenv" operation.
2767
2768 BE CAREFUL! Any changes to the flash layout, and some changes to the
2769 source code will make it necessary to adapt <board>/u-boot.lds*
2770 accordingly!
2771
2772
2773 - CONFIG_ENV_IS_IN_NVRAM:
2774
2775 Define this if you have some non-volatile memory device
2776 (NVRAM, battery buffered SRAM) which you want to use for the
2777 environment.
2778
2779 - CONFIG_ENV_ADDR:
2780 - CONFIG_ENV_SIZE:
2781
2782 These two #defines are used to determine the memory area you
2783 want to use for environment. It is assumed that this memory
2784 can just be read and written to, without any special
2785 provision.
2786
2787 BE CAREFUL! The first access to the environment happens quite early
2788 in U-Boot initalization (when we try to get the setting of for the
2789 console baudrate). You *MUST* have mapped your NVRAM area then, or
2790 U-Boot will hang.
2791
2792 Please note that even with NVRAM we still use a copy of the
2793 environment in RAM: we could work on NVRAM directly, but we want to
2794 keep settings there always unmodified except somebody uses "saveenv"
2795 to save the current settings.
2796
2797
2798 - CONFIG_ENV_IS_IN_EEPROM:
2799
2800 Use this if you have an EEPROM or similar serial access
2801 device and a driver for it.
2802
2803 - CONFIG_ENV_OFFSET:
2804 - CONFIG_ENV_SIZE:
2805
2806 These two #defines specify the offset and size of the
2807 environment area within the total memory of your EEPROM.
2808
2809 - CONFIG_SYS_I2C_EEPROM_ADDR:
2810 If defined, specified the chip address of the EEPROM device.
2811 The default address is zero.
2812
2813 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2814 If defined, the number of bits used to address bytes in a
2815 single page in the EEPROM device. A 64 byte page, for example
2816 would require six bits.
2817
2818 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2819 If defined, the number of milliseconds to delay between
2820 page writes. The default is zero milliseconds.
2821
2822 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2823 The length in bytes of the EEPROM memory array address. Note
2824 that this is NOT the chip address length!
2825
2826 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2827 EEPROM chips that implement "address overflow" are ones
2828 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2829 address and the extra bits end up in the "chip address" bit
2830 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2831 byte chips.
2832
2833 Note that we consider the length of the address field to
2834 still be one byte because the extra address bits are hidden
2835 in the chip address.
2836
2837 - CONFIG_SYS_EEPROM_SIZE:
2838 The size in bytes of the EEPROM device.
2839
2840 - CONFIG_ENV_EEPROM_IS_ON_I2C
2841 define this, if you have I2C and SPI activated, and your
2842 EEPROM, which holds the environment, is on the I2C bus.
2843
2844 - CONFIG_I2C_ENV_EEPROM_BUS
2845 if you have an Environment on an EEPROM reached over
2846 I2C muxes, you can define here, how to reach this
2847 EEPROM. For example:
2848
2849 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2850
2851 EEPROM which holds the environment, is reached over
2852 a pca9547 i2c mux with address 0x70, channel 3.
2853
2854 - CONFIG_ENV_IS_IN_DATAFLASH:
2855
2856 Define this if you have a DataFlash memory device which you
2857 want to use for the environment.
2858
2859 - CONFIG_ENV_OFFSET:
2860 - CONFIG_ENV_ADDR:
2861 - CONFIG_ENV_SIZE:
2862
2863 These three #defines specify the offset and size of the
2864 environment area within the total memory of your DataFlash placed
2865 at the specified address.
2866
2867 - CONFIG_ENV_IS_IN_NAND:
2868
2869 Define this if you have a NAND device which you want to use
2870 for the environment.
2871
2872 - CONFIG_ENV_OFFSET:
2873 - CONFIG_ENV_SIZE:
2874
2875 These two #defines specify the offset and size of the environment
2876 area within the first NAND device. CONFIG_ENV_OFFSET must be
2877 aligned to an erase block boundary.
2878
2879 - CONFIG_ENV_OFFSET_REDUND (optional):
2880
2881 This setting describes a second storage area of CONFIG_ENV_SIZE
2882 size used to hold a redundant copy of the environment data, so
2883 that there is a valid backup copy in case there is a power failure
2884 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2885 aligned to an erase block boundary.
2886
2887 - CONFIG_ENV_RANGE (optional):
2888
2889 Specifies the length of the region in which the environment
2890 can be written. This should be a multiple of the NAND device's
2891 block size. Specifying a range with more erase blocks than
2892 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2893 the range to be avoided.
2894
2895 - CONFIG_ENV_OFFSET_OOB (optional):
2896
2897 Enables support for dynamically retrieving the offset of the
2898 environment from block zero's out-of-band data. The
2899 "nand env.oob" command can be used to record this offset.
2900 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2901 using CONFIG_ENV_OFFSET_OOB.
2902
2903 - CONFIG_NAND_ENV_DST
2904
2905 Defines address in RAM to which the nand_spl code should copy the
2906 environment. If redundant environment is used, it will be copied to
2907 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2908
2909 - CONFIG_SYS_SPI_INIT_OFFSET
2910
2911 Defines offset to the initial SPI buffer area in DPRAM. The
2912 area is used at an early stage (ROM part) if the environment
2913 is configured to reside in the SPI EEPROM: We need a 520 byte
2914 scratch DPRAM area. It is used between the two initialization
2915 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2916 to be a good choice since it makes it far enough from the
2917 start of the data area as well as from the stack pointer.
2918
2919 Please note that the environment is read-only until the monitor
2920 has been relocated to RAM and a RAM copy of the environment has been
2921 created; also, when using EEPROM you will have to use getenv_f()
2922 until then to read environment variables.
2923
2924 The environment is protected by a CRC32 checksum. Before the monitor
2925 is relocated into RAM, as a result of a bad CRC you will be working
2926 with the compiled-in default environment - *silently*!!! [This is
2927 necessary, because the first environment variable we need is the
2928 "baudrate" setting for the console - if we have a bad CRC, we don't
2929 have any device yet where we could complain.]
2930
2931 Note: once the monitor has been relocated, then it will complain if
2932 the default environment is used; a new CRC is computed as soon as you
2933 use the "saveenv" command to store a valid environment.
2934
2935 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2936 Echo the inverted Ethernet link state to the fault LED.
2937
2938 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2939 also needs to be defined.
2940
2941 - CONFIG_SYS_FAULT_MII_ADDR:
2942 MII address of the PHY to check for the Ethernet link state.
2943
2944 - CONFIG_NS16550_MIN_FUNCTIONS:
2945 Define this if you desire to only have use of the NS16550_init
2946 and NS16550_putc functions for the serial driver located at
2947 drivers/serial/ns16550.c. This option is useful for saving
2948 space for already greatly restricted images, including but not
2949 limited to NAND_SPL configurations.
2950
2951 Low Level (hardware related) configuration options:
2952 ---------------------------------------------------
2953
2954 - CONFIG_SYS_CACHELINE_SIZE:
2955 Cache Line Size of the CPU.
2956
2957 - CONFIG_SYS_DEFAULT_IMMR:
2958 Default address of the IMMR after system reset.
2959
2960 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2961 and RPXsuper) to be able to adjust the position of
2962 the IMMR register after a reset.
2963
2964 - CONFIG_SYS_CCSRBAR_DEFAULT:
2965 Default (power-on reset) physical address of CCSR on Freescale
2966 PowerPC SOCs.
2967
2968 - CONFIG_SYS_CCSRBAR:
2969 Virtual address of CCSR. On a 32-bit build, this is typically
2970 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
2971
2972 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
2973 for cross-platform code that uses that macro instead.
2974
2975 - CONFIG_SYS_CCSRBAR_PHYS:
2976 Physical address of CCSR. CCSR can be relocated to a new
2977 physical address, if desired. In this case, this macro should
2978 be set to that address. Otherwise, it should be set to the
2979 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
2980 is typically relocated on 36-bit builds. It is recommended
2981 that this macro be defined via the _HIGH and _LOW macros:
2982
2983 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
2984 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
2985
2986 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
2987 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
2988 either 0 (32-bit build) or 0xF (36-bit build). This macro is
2989 used in assembly code, so it must not contain typecasts or
2990 integer size suffixes (e.g. "ULL").
2991
2992 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
2993 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
2994 used in assembly code, so it must not contain typecasts or
2995 integer size suffixes (e.g. "ULL").
2996
2997 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
2998 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
2999 forced to a value that ensures that CCSR is not relocated.
3000
3001 - Floppy Disk Support:
3002 CONFIG_SYS_FDC_DRIVE_NUMBER
3003
3004 the default drive number (default value 0)
3005
3006 CONFIG_SYS_ISA_IO_STRIDE
3007
3008 defines the spacing between FDC chipset registers
3009 (default value 1)
3010
3011 CONFIG_SYS_ISA_IO_OFFSET
3012
3013 defines the offset of register from address. It
3014 depends on which part of the data bus is connected to
3015 the FDC chipset. (default value 0)
3016
3017 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3018 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3019 default value.
3020
3021 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3022 fdc_hw_init() is called at the beginning of the FDC
3023 setup. fdc_hw_init() must be provided by the board
3024 source code. It is used to make hardware dependant
3025 initializations.
3026
3027 - CONFIG_IDE_AHB:
3028 Most IDE controllers were designed to be connected with PCI
3029 interface. Only few of them were designed for AHB interface.
3030 When software is doing ATA command and data transfer to
3031 IDE devices through IDE-AHB controller, some additional
3032 registers accessing to these kind of IDE-AHB controller
3033 is requierd.
3034
3035 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3036 DO NOT CHANGE unless you know exactly what you're
3037 doing! (11-4) [MPC8xx/82xx systems only]
3038
3039 - CONFIG_SYS_INIT_RAM_ADDR:
3040
3041 Start address of memory area that can be used for
3042 initial data and stack; please note that this must be
3043 writable memory that is working WITHOUT special
3044 initialization, i. e. you CANNOT use normal RAM which
3045 will become available only after programming the
3046 memory controller and running certain initialization
3047 sequences.
3048
3049 U-Boot uses the following memory types:
3050 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
3051 - MPC824X: data cache
3052 - PPC4xx: data cache
3053
3054 - CONFIG_SYS_GBL_DATA_OFFSET:
3055
3056 Offset of the initial data structure in the memory
3057 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3058 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3059 data is located at the end of the available space
3060 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3061 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
3062 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3063 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3064
3065 Note:
3066 On the MPC824X (or other systems that use the data
3067 cache for initial memory) the address chosen for
3068 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3069 point to an otherwise UNUSED address space between
3070 the top of RAM and the start of the PCI space.
3071
3072 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3073
3074 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3075
3076 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3077
3078 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3079
3080 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3081
3082 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3083
3084 - CONFIG_SYS_OR_TIMING_SDRAM:
3085 SDRAM timing
3086
3087 - CONFIG_SYS_MAMR_PTA:
3088 periodic timer for refresh
3089
3090 - CONFIG_SYS_DER: Debug Event Register (37-47)
3091
3092 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3093 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3094 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3095 CONFIG_SYS_BR1_PRELIM:
3096 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3097
3098 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3099 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3100 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3101 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3102
3103 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3104 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3105 Machine Mode Register and Memory Periodic Timer
3106 Prescaler definitions (SDRAM timing)
3107
3108 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3109 enable I2C microcode relocation patch (MPC8xx);
3110 define relocation offset in DPRAM [DSP2]
3111
3112 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3113 enable SMC microcode relocation patch (MPC8xx);
3114 define relocation offset in DPRAM [SMC1]
3115
3116 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3117 enable SPI microcode relocation patch (MPC8xx);
3118 define relocation offset in DPRAM [SCC4]
3119
3120 - CONFIG_SYS_USE_OSCCLK:
3121 Use OSCM clock mode on MBX8xx board. Be careful,
3122 wrong setting might damage your board. Read
3123 doc/README.MBX before setting this variable!
3124
3125 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3126 Offset of the bootmode word in DPRAM used by post
3127 (Power On Self Tests). This definition overrides
3128 #define'd default value in commproc.h resp.
3129 cpm_8260.h.
3130
3131 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3132 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3133 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3134 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3135 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3136 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3137 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3138 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3139 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3140
3141 - CONFIG_PCI_DISABLE_PCIE:
3142 Disable PCI-Express on systems where it is supported but not
3143 required.
3144
3145 - CONFIG_SYS_SRIO:
3146 Chip has SRIO or not
3147
3148 - CONFIG_SRIO1:
3149 Board has SRIO 1 port available
3150
3151 - CONFIG_SRIO2:
3152 Board has SRIO 2 port available
3153
3154 - CONFIG_SYS_SRIOn_MEM_VIRT:
3155 Virtual Address of SRIO port 'n' memory region
3156
3157 - CONFIG_SYS_SRIOn_MEM_PHYS:
3158 Physical Address of SRIO port 'n' memory region
3159
3160 - CONFIG_SYS_SRIOn_MEM_SIZE:
3161 Size of SRIO port 'n' memory region
3162
3163 - CONFIG_SYS_NDFC_16
3164 Defined to tell the NDFC that the NAND chip is using a
3165 16 bit bus.
3166
3167 - CONFIG_SYS_NDFC_EBC0_CFG
3168 Sets the EBC0_CFG register for the NDFC. If not defined
3169 a default value will be used.
3170
3171 - CONFIG_SPD_EEPROM
3172 Get DDR timing information from an I2C EEPROM. Common
3173 with pluggable memory modules such as SODIMMs
3174
3175 SPD_EEPROM_ADDRESS
3176 I2C address of the SPD EEPROM
3177
3178 - CONFIG_SYS_SPD_BUS_NUM
3179 If SPD EEPROM is on an I2C bus other than the first
3180 one, specify here. Note that the value must resolve
3181 to something your driver can deal with.
3182
3183 - CONFIG_SYS_DDR_RAW_TIMING
3184 Get DDR timing information from other than SPD. Common with
3185 soldered DDR chips onboard without SPD. DDR raw timing
3186 parameters are extracted from datasheet and hard-coded into
3187 header files or board specific files.
3188
3189 - CONFIG_FSL_DDR_INTERACTIVE
3190 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3191
3192 - CONFIG_SYS_83XX_DDR_USES_CS0
3193 Only for 83xx systems. If specified, then DDR should
3194 be configured using CS0 and CS1 instead of CS2 and CS3.
3195
3196 - CONFIG_ETHER_ON_FEC[12]
3197 Define to enable FEC[12] on a 8xx series processor.
3198
3199 - CONFIG_FEC[12]_PHY
3200 Define to the hardcoded PHY address which corresponds
3201 to the given FEC; i. e.
3202 #define CONFIG_FEC1_PHY 4
3203 means that the PHY with address 4 is connected to FEC1
3204
3205 When set to -1, means to probe for first available.
3206
3207 - CONFIG_FEC[12]_PHY_NORXERR
3208 The PHY does not have a RXERR line (RMII only).
3209 (so program the FEC to ignore it).
3210
3211 - CONFIG_RMII
3212 Enable RMII mode for all FECs.
3213 Note that this is a global option, we can't
3214 have one FEC in standard MII mode and another in RMII mode.
3215
3216 - CONFIG_CRC32_VERIFY
3217 Add a verify option to the crc32 command.
3218 The syntax is:
3219
3220 => crc32 -v <address> <count> <crc32>
3221
3222 Where address/count indicate a memory area
3223 and crc32 is the correct crc32 which the
3224 area should have.
3225
3226 - CONFIG_LOOPW
3227 Add the "loopw" memory command. This only takes effect if
3228 the memory commands are activated globally (CONFIG_CMD_MEM).
3229
3230 - CONFIG_MX_CYCLIC
3231 Add the "mdc" and "mwc" memory commands. These are cyclic
3232 "md/mw" commands.
3233 Examples:
3234
3235 => mdc.b 10 4 500
3236 This command will print 4 bytes (10,11,12,13) each 500 ms.
3237
3238 => mwc.l 100 12345678 10
3239 This command will write 12345678 to address 100 all 10 ms.
3240
3241 This only takes effect if the memory commands are activated
3242 globally (CONFIG_CMD_MEM).
3243
3244 - CONFIG_SKIP_LOWLEVEL_INIT
3245 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3246 low level initializations (like setting up the memory
3247 controller) are omitted and/or U-Boot does not
3248 relocate itself into RAM.
3249
3250 Normally this variable MUST NOT be defined. The only
3251 exception is when U-Boot is loaded (to RAM) by some
3252 other boot loader or by a debugger which performs
3253 these initializations itself.
3254
3255 - CONFIG_SPL_BUILD
3256 Modifies the behaviour of start.S when compiling a loader
3257 that is executed before the actual U-Boot. E.g. when
3258 compiling a NAND SPL.
3259
3260 - CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3261 define this, if you want to read first the oob data
3262 and then the data. This is used for example on
3263 davinci plattforms.
3264
3265 - CONFIG_USE_ARCH_MEMCPY
3266 CONFIG_USE_ARCH_MEMSET
3267 If these options are used a optimized version of memcpy/memset will
3268 be used if available. These functions may be faster under some
3269 conditions but may increase the binary size.
3270
3271 Building the Software:
3272 ======================
3273
3274 Building U-Boot has been tested in several native build environments
3275 and in many different cross environments. Of course we cannot support
3276 all possibly existing versions of cross development tools in all
3277 (potentially obsolete) versions. In case of tool chain problems we
3278 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3279 which is extensively used to build and test U-Boot.
3280
3281 If you are not using a native environment, it is assumed that you
3282 have GNU cross compiling tools available in your path. In this case,
3283 you must set the environment variable CROSS_COMPILE in your shell.
3284 Note that no changes to the Makefile or any other source files are
3285 necessary. For example using the ELDK on a 4xx CPU, please enter:
3286
3287 $ CROSS_COMPILE=ppc_4xx-
3288 $ export CROSS_COMPILE
3289
3290 Note: If you wish to generate Windows versions of the utilities in
3291 the tools directory you can use the MinGW toolchain
3292 (http://www.mingw.org). Set your HOST tools to the MinGW
3293 toolchain and execute 'make tools'. For example:
3294
3295 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3296
3297 Binaries such as tools/mkimage.exe will be created which can
3298 be executed on computers running Windows.
3299
3300 U-Boot is intended to be simple to build. After installing the
3301 sources you must configure U-Boot for one specific board type. This
3302 is done by typing:
3303
3304 make NAME_config
3305
3306 where "NAME_config" is the name of one of the existing configu-
3307 rations; see the main Makefile for supported names.
3308
3309 Note: for some board special configuration names may exist; check if
3310 additional information is available from the board vendor; for
3311 instance, the TQM823L systems are available without (standard)
3312 or with LCD support. You can select such additional "features"
3313 when choosing the configuration, i. e.
3314
3315 make TQM823L_config
3316 - will configure for a plain TQM823L, i. e. no LCD support
3317
3318 make TQM823L_LCD_config
3319 - will configure for a TQM823L with U-Boot console on LCD
3320
3321 etc.
3322
3323
3324 Finally, type "make all", and you should get some working U-Boot
3325 images ready for download to / installation on your system:
3326
3327 - "u-boot.bin" is a raw binary image
3328 - "u-boot" is an image in ELF binary format
3329 - "u-boot.srec" is in Motorola S-Record format
3330
3331 By default the build is performed locally and the objects are saved
3332 in the source directory. One of the two methods can be used to change
3333 this behavior and build U-Boot to some external directory:
3334
3335 1. Add O= to the make command line invocations:
3336
3337 make O=/tmp/build distclean
3338 make O=/tmp/build NAME_config
3339 make O=/tmp/build all
3340
3341 2. Set environment variable BUILD_DIR to point to the desired location:
3342
3343 export BUILD_DIR=/tmp/build
3344 make distclean
3345 make NAME_config
3346 make all
3347
3348 Note that the command line "O=" setting overrides the BUILD_DIR environment
3349 variable.
3350
3351
3352 Please be aware that the Makefiles assume you are using GNU make, so
3353 for instance on NetBSD you might need to use "gmake" instead of
3354 native "make".
3355
3356
3357 If the system board that you have is not listed, then you will need
3358 to port U-Boot to your hardware platform. To do this, follow these
3359 steps:
3360
3361 1. Add a new configuration option for your board to the toplevel
3362 "Makefile" and to the "MAKEALL" script, using the existing
3363 entries as examples. Note that here and at many other places
3364 boards and other names are listed in alphabetical sort order. Please
3365 keep this order.
3366 2. Create a new directory to hold your board specific code. Add any
3367 files you need. In your board directory, you will need at least
3368 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3369 3. Create a new configuration file "include/configs/<board>.h" for
3370 your board
3371 3. If you're porting U-Boot to a new CPU, then also create a new
3372 directory to hold your CPU specific code. Add any files you need.
3373 4. Run "make <board>_config" with your new name.
3374 5. Type "make", and you should get a working "u-boot.srec" file
3375 to be installed on your target system.
3376 6. Debug and solve any problems that might arise.
3377 [Of course, this last step is much harder than it sounds.]
3378
3379
3380 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3381 ==============================================================
3382
3383 If you have modified U-Boot sources (for instance added a new board
3384 or support for new devices, a new CPU, etc.) you are expected to
3385 provide feedback to the other developers. The feedback normally takes
3386 the form of a "patch", i. e. a context diff against a certain (latest
3387 official or latest in the git repository) version of U-Boot sources.
3388
3389 But before you submit such a patch, please verify that your modifi-
3390 cation did not break existing code. At least make sure that *ALL* of
3391 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3392 just run the "MAKEALL" script, which will configure and build U-Boot
3393 for ALL supported system. Be warned, this will take a while. You can
3394 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3395 environment variable to the script, i. e. to use the ELDK cross tools
3396 you can type
3397
3398 CROSS_COMPILE=ppc_8xx- MAKEALL
3399
3400 or to build on a native PowerPC system you can type
3401
3402 CROSS_COMPILE=' ' MAKEALL
3403
3404 When using the MAKEALL script, the default behaviour is to build
3405 U-Boot in the source directory. This location can be changed by
3406 setting the BUILD_DIR environment variable. Also, for each target
3407 built, the MAKEALL script saves two log files (<target>.ERR and
3408 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3409 location can be changed by setting the MAKEALL_LOGDIR environment
3410 variable. For example:
3411
3412 export BUILD_DIR=/tmp/build
3413 export MAKEALL_LOGDIR=/tmp/log
3414 CROSS_COMPILE=ppc_8xx- MAKEALL
3415
3416 With the above settings build objects are saved in the /tmp/build,
3417 log files are saved in the /tmp/log and the source tree remains clean
3418 during the whole build process.
3419
3420
3421 See also "U-Boot Porting Guide" below.
3422
3423
3424 Monitor Commands - Overview:
3425 ============================
3426
3427 go - start application at address 'addr'
3428 run - run commands in an environment variable
3429 bootm - boot application image from memory
3430 bootp - boot image via network using BootP/TFTP protocol
3431 tftpboot- boot image via network using TFTP protocol
3432 and env variables "ipaddr" and "serverip"
3433 (and eventually "gatewayip")
3434 tftpput - upload a file via network using TFTP protocol
3435 rarpboot- boot image via network using RARP/TFTP protocol
3436 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3437 loads - load S-Record file over serial line
3438 loadb - load binary file over serial line (kermit mode)
3439 md - memory display
3440 mm - memory modify (auto-incrementing)
3441 nm - memory modify (constant address)
3442 mw - memory write (fill)
3443 cp - memory copy
3444 cmp - memory compare
3445 crc32 - checksum calculation
3446 i2c - I2C sub-system
3447 sspi - SPI utility commands
3448 base - print or set address offset
3449 printenv- print environment variables
3450 setenv - set environment variables
3451 saveenv - save environment variables to persistent storage
3452 protect - enable or disable FLASH write protection
3453 erase - erase FLASH memory
3454 flinfo - print FLASH memory information
3455 bdinfo - print Board Info structure
3456 iminfo - print header information for application image
3457 coninfo - print console devices and informations
3458 ide - IDE sub-system
3459 loop - infinite loop on address range
3460 loopw - infinite write loop on address range
3461 mtest - simple RAM test
3462 icache - enable or disable instruction cache
3463 dcache - enable or disable data cache
3464 reset - Perform RESET of the CPU
3465 echo - echo args to console
3466 version - print monitor version
3467 help - print online help
3468 ? - alias for 'help'
3469
3470
3471 Monitor Commands - Detailed Description:
3472 ========================================
3473
3474 TODO.
3475
3476 For now: just type "help <command>".
3477
3478
3479 Environment Variables:
3480 ======================
3481
3482 U-Boot supports user configuration using Environment Variables which
3483 can be made persistent by saving to Flash memory.
3484
3485 Environment Variables are set using "setenv", printed using
3486 "printenv", and saved to Flash using "saveenv". Using "setenv"
3487 without a value can be used to delete a variable from the
3488 environment. As long as you don't save the environment you are
3489 working with an in-memory copy. In case the Flash area containing the
3490 environment is erased by accident, a default environment is provided.
3491
3492 Some configuration options can be set using Environment Variables.
3493
3494 List of environment variables (most likely not complete):
3495
3496 baudrate - see CONFIG_BAUDRATE
3497
3498 bootdelay - see CONFIG_BOOTDELAY
3499
3500 bootcmd - see CONFIG_BOOTCOMMAND
3501
3502 bootargs - Boot arguments when booting an RTOS image
3503
3504 bootfile - Name of the image to load with TFTP
3505
3506 bootm_low - Memory range available for image processing in the bootm
3507 command can be restricted. This variable is given as
3508 a hexadecimal number and defines lowest address allowed
3509 for use by the bootm command. See also "bootm_size"
3510 environment variable. Address defined by "bootm_low" is
3511 also the base of the initial memory mapping for the Linux
3512 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3513 bootm_mapsize.
3514
3515 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3516 This variable is given as a hexadecimal number and it
3517 defines the size of the memory region starting at base
3518 address bootm_low that is accessible by the Linux kernel
3519 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3520 as the default value if it is defined, and bootm_size is
3521 used otherwise.
3522
3523 bootm_size - Memory range available for image processing in the bootm
3524 command can be restricted. This variable is given as
3525 a hexadecimal number and defines the size of the region
3526 allowed for use by the bootm command. See also "bootm_low"
3527 environment variable.
3528
3529 updatefile - Location of the software update file on a TFTP server, used
3530 by the automatic software update feature. Please refer to
3531 documentation in doc/README.update for more details.
3532
3533 autoload - if set to "no" (any string beginning with 'n'),
3534 "bootp" will just load perform a lookup of the
3535 configuration from the BOOTP server, but not try to
3536 load any image using TFTP
3537
3538 autostart - if set to "yes", an image loaded using the "bootp",
3539 "rarpboot", "tftpboot" or "diskboot" commands will
3540 be automatically started (by internally calling
3541 "bootm")
3542
3543 If set to "no", a standalone image passed to the
3544 "bootm" command will be copied to the load address
3545 (and eventually uncompressed), but NOT be started.
3546 This can be used to load and uncompress arbitrary
3547 data.
3548
3549 fdt_high - if set this restricts the maximum address that the
3550 flattened device tree will be copied into upon boot.
3551 If this is set to the special value 0xFFFFFFFF then
3552 the fdt will not be copied at all on boot. For this
3553 to work it must reside in writable memory, have
3554 sufficient padding on the end of it for u-boot to
3555 add the information it needs into it, and the memory
3556 must be accessible by the kernel.
3557
3558 fdtcontroladdr- if set this is the address of the control flattened
3559 device tree used by U-Boot when CONFIG_OF_CONTROL is
3560 defined.
3561
3562 i2cfast - (PPC405GP|PPC405EP only)
3563 if set to 'y' configures Linux I2C driver for fast
3564 mode (400kHZ). This environment variable is used in
3565 initialization code. So, for changes to be effective
3566 it must be saved and board must be reset.
3567
3568 initrd_high - restrict positioning of initrd images:
3569 If this variable is not set, initrd images will be
3570 copied to the highest possible address in RAM; this
3571 is usually what you want since it allows for
3572 maximum initrd size. If for some reason you want to
3573 make sure that the initrd image is loaded below the
3574 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3575 variable to a value of "no" or "off" or "0".
3576 Alternatively, you can set it to a maximum upper
3577 address to use (U-Boot will still check that it
3578 does not overwrite the U-Boot stack and data).
3579
3580 For instance, when you have a system with 16 MB
3581 RAM, and want to reserve 4 MB from use by Linux,
3582 you can do this by adding "mem=12M" to the value of
3583 the "bootargs" variable. However, now you must make
3584 sure that the initrd image is placed in the first
3585 12 MB as well - this can be done with
3586
3587 setenv initrd_high 00c00000
3588
3589 If you set initrd_high to 0xFFFFFFFF, this is an
3590 indication to U-Boot that all addresses are legal
3591 for the Linux kernel, including addresses in flash
3592 memory. In this case U-Boot will NOT COPY the
3593 ramdisk at all. This may be useful to reduce the
3594 boot time on your system, but requires that this
3595 feature is supported by your Linux kernel.
3596
3597 ipaddr - IP address; needed for tftpboot command
3598
3599 loadaddr - Default load address for commands like "bootp",
3600 "rarpboot", "tftpboot", "loadb" or "diskboot"
3601
3602 loads_echo - see CONFIG_LOADS_ECHO
3603
3604 serverip - TFTP server IP address; needed for tftpboot command
3605
3606 bootretry - see CONFIG_BOOT_RETRY_TIME
3607
3608 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3609
3610 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3611
3612 ethprime - controls which interface is used first.
3613
3614 ethact - controls which interface is currently active.
3615 For example you can do the following
3616
3617 => setenv ethact FEC
3618 => ping 192.168.0.1 # traffic sent on FEC
3619 => setenv ethact SCC
3620 => ping 10.0.0.1 # traffic sent on SCC
3621
3622 ethrotate - When set to "no" U-Boot does not go through all
3623 available network interfaces.
3624 It just stays at the currently selected interface.
3625
3626 netretry - When set to "no" each network operation will
3627 either succeed or fail without retrying.
3628 When set to "once" the network operation will
3629 fail when all the available network interfaces
3630 are tried once without success.
3631 Useful on scripts which control the retry operation
3632 themselves.
3633
3634 npe_ucode - set load address for the NPE microcode
3635
3636 tftpsrcport - If this is set, the value is used for TFTP's
3637 UDP source port.
3638
3639 tftpdstport - If this is set, the value is used for TFTP's UDP
3640 destination port instead of the Well Know Port 69.
3641
3642 tftpblocksize - Block size to use for TFTP transfers; if not set,
3643 we use the TFTP server's default block size
3644
3645 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3646 seconds, minimum value is 1000 = 1 second). Defines
3647 when a packet is considered to be lost so it has to
3648 be retransmitted. The default is 5000 = 5 seconds.
3649 Lowering this value may make downloads succeed
3650 faster in networks with high packet loss rates or
3651 with unreliable TFTP servers.
3652
3653 vlan - When set to a value < 4095 the traffic over
3654 Ethernet is encapsulated/received over 802.1q
3655 VLAN tagged frames.
3656
3657 The following image location variables contain the location of images
3658 used in booting. The "Image" column gives the role of the image and is
3659 not an environment variable name. The other columns are environment
3660 variable names. "File Name" gives the name of the file on a TFTP
3661 server, "RAM Address" gives the location in RAM the image will be
3662 loaded to, and "Flash Location" gives the image's address in NOR
3663 flash or offset in NAND flash.
3664
3665 *Note* - these variables don't have to be defined for all boards, some
3666 boards currenlty use other variables for these purposes, and some
3667 boards use these variables for other purposes.
3668
3669 Image File Name RAM Address Flash Location
3670 ----- --------- ----------- --------------
3671 u-boot u-boot u-boot_addr_r u-boot_addr
3672 Linux kernel bootfile kernel_addr_r kernel_addr
3673 device tree blob fdtfile fdt_addr_r fdt_addr
3674 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
3675
3676 The following environment variables may be used and automatically
3677 updated by the network boot commands ("bootp" and "rarpboot"),
3678 depending the information provided by your boot server:
3679
3680 bootfile - see above
3681 dnsip - IP address of your Domain Name Server
3682 dnsip2 - IP address of your secondary Domain Name Server
3683 gatewayip - IP address of the Gateway (Router) to use
3684 hostname - Target hostname
3685 ipaddr - see above
3686 netmask - Subnet Mask
3687 rootpath - Pathname of the root filesystem on the NFS server
3688 serverip - see above
3689
3690
3691 There are two special Environment Variables:
3692
3693 serial# - contains hardware identification information such
3694 as type string and/or serial number
3695 ethaddr - Ethernet address
3696
3697 These variables can be set only once (usually during manufacturing of
3698 the board). U-Boot refuses to delete or overwrite these variables
3699 once they have been set once.
3700
3701
3702 Further special Environment Variables:
3703
3704 ver - Contains the U-Boot version string as printed
3705 with the "version" command. This variable is
3706 readonly (see CONFIG_VERSION_VARIABLE).
3707
3708
3709 Please note that changes to some configuration parameters may take
3710 only effect after the next boot (yes, that's just like Windoze :-).
3711
3712
3713 Command Line Parsing:
3714 =====================
3715
3716 There are two different command line parsers available with U-Boot:
3717 the old "simple" one, and the much more powerful "hush" shell:
3718
3719 Old, simple command line parser:
3720 --------------------------------
3721
3722 - supports environment variables (through setenv / saveenv commands)
3723 - several commands on one line, separated by ';'
3724 - variable substitution using "... ${name} ..." syntax
3725 - special characters ('$', ';') can be escaped by prefixing with '\',
3726 for example:
3727 setenv bootcmd bootm \${address}
3728 - You can also escape text by enclosing in single apostrophes, for example:
3729 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3730
3731 Hush shell:
3732 -----------
3733
3734 - similar to Bourne shell, with control structures like
3735 if...then...else...fi, for...do...done; while...do...done,
3736 until...do...done, ...
3737 - supports environment ("global") variables (through setenv / saveenv
3738 commands) and local shell variables (through standard shell syntax
3739 "name=value"); only environment variables can be used with "run"
3740 command
3741
3742 General rules:
3743 --------------
3744
3745 (1) If a command line (or an environment variable executed by a "run"
3746 command) contains several commands separated by semicolon, and
3747 one of these commands fails, then the remaining commands will be
3748 executed anyway.
3749
3750 (2) If you execute several variables with one call to run (i. e.
3751 calling run with a list of variables as arguments), any failing
3752 command will cause "run" to terminate, i. e. the remaining
3753 variables are not executed.
3754
3755 Note for Redundant Ethernet Interfaces:
3756 =======================================
3757
3758 Some boards come with redundant Ethernet interfaces; U-Boot supports
3759 such configurations and is capable of automatic selection of a
3760 "working" interface when needed. MAC assignment works as follows:
3761
3762 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3763 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3764 "eth1addr" (=>eth1), "eth2addr", ...
3765
3766 If the network interface stores some valid MAC address (for instance
3767 in SROM), this is used as default address if there is NO correspon-
3768 ding setting in the environment; if the corresponding environment
3769 variable is set, this overrides the settings in the card; that means:
3770
3771 o If the SROM has a valid MAC address, and there is no address in the
3772 environment, the SROM's address is used.
3773
3774 o If there is no valid address in the SROM, and a definition in the
3775 environment exists, then the value from the environment variable is
3776 used.
3777
3778 o If both the SROM and the environment contain a MAC address, and
3779 both addresses are the same, this MAC address is used.
3780
3781 o If both the SROM and the environment contain a MAC address, and the
3782 addresses differ, the value from the environment is used and a
3783 warning is printed.
3784
3785 o If neither SROM nor the environment contain a MAC address, an error
3786 is raised.
3787
3788 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3789 will be programmed into hardware as part of the initialization process. This
3790 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3791 The naming convention is as follows:
3792 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3793
3794 Image Formats:
3795 ==============
3796
3797 U-Boot is capable of booting (and performing other auxiliary operations on)
3798 images in two formats:
3799
3800 New uImage format (FIT)
3801 -----------------------
3802
3803 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3804 to Flattened Device Tree). It allows the use of images with multiple
3805 components (several kernels, ramdisks, etc.), with contents protected by
3806 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3807
3808
3809 Old uImage format
3810 -----------------
3811
3812 Old image format is based on binary files which can be basically anything,
3813 preceded by a special header; see the definitions in include/image.h for
3814 details; basically, the header defines the following image properties:
3815
3816 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3817 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3818 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3819 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3820 INTEGRITY).
3821 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3822 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3823 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
3824 * Compression Type (uncompressed, gzip, bzip2)
3825 * Load Address
3826 * Entry Point
3827 * Image Name
3828 * Image Timestamp
3829
3830 The header is marked by a special Magic Number, and both the header
3831 and the data portions of the image are secured against corruption by
3832 CRC32 checksums.
3833
3834
3835 Linux Support:
3836 ==============
3837
3838 Although U-Boot should support any OS or standalone application
3839 easily, the main focus has always been on Linux during the design of
3840 U-Boot.
3841
3842 U-Boot includes many features that so far have been part of some
3843 special "boot loader" code within the Linux kernel. Also, any
3844 "initrd" images to be used are no longer part of one big Linux image;
3845 instead, kernel and "initrd" are separate images. This implementation
3846 serves several purposes:
3847
3848 - the same features can be used for other OS or standalone
3849 applications (for instance: using compressed images to reduce the
3850 Flash memory footprint)
3851
3852 - it becomes much easier to port new Linux kernel versions because
3853 lots of low-level, hardware dependent stuff are done by U-Boot
3854
3855 - the same Linux kernel image can now be used with different "initrd"
3856 images; of course this also means that different kernel images can
3857 be run with the same "initrd". This makes testing easier (you don't
3858 have to build a new "zImage.initrd" Linux image when you just
3859 change a file in your "initrd"). Also, a field-upgrade of the
3860 software is easier now.
3861
3862
3863 Linux HOWTO:
3864 ============
3865
3866 Porting Linux to U-Boot based systems:
3867 ---------------------------------------
3868
3869 U-Boot cannot save you from doing all the necessary modifications to
3870 configure the Linux device drivers for use with your target hardware
3871 (no, we don't intend to provide a full virtual machine interface to
3872 Linux :-).
3873
3874 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3875
3876 Just make sure your machine specific header file (for instance
3877 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3878 Information structure as we define in include/asm-<arch>/u-boot.h,
3879 and make sure that your definition of IMAP_ADDR uses the same value
3880 as your U-Boot configuration in CONFIG_SYS_IMMR.
3881
3882
3883 Configuring the Linux kernel:
3884 -----------------------------
3885
3886 No specific requirements for U-Boot. Make sure you have some root
3887 device (initial ramdisk, NFS) for your target system.
3888
3889
3890 Building a Linux Image:
3891 -----------------------
3892
3893 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3894 not used. If you use recent kernel source, a new build target
3895 "uImage" will exist which automatically builds an image usable by
3896 U-Boot. Most older kernels also have support for a "pImage" target,
3897 which was introduced for our predecessor project PPCBoot and uses a
3898 100% compatible format.
3899
3900 Example:
3901
3902 make TQM850L_config
3903 make oldconfig
3904 make dep
3905 make uImage
3906
3907 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3908 encapsulate a compressed Linux kernel image with header information,
3909 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3910
3911 * build a standard "vmlinux" kernel image (in ELF binary format):
3912
3913 * convert the kernel into a raw binary image:
3914
3915 ${CROSS_COMPILE}-objcopy -O binary \
3916 -R .note -R .comment \
3917 -S vmlinux linux.bin
3918
3919 * compress the binary image:
3920
3921 gzip -9 linux.bin
3922
3923 * package compressed binary image for U-Boot:
3924
3925 mkimage -A ppc -O linux -T kernel -C gzip \
3926 -a 0 -e 0 -n "Linux Kernel Image" \
3927 -d linux.bin.gz uImage
3928
3929
3930 The "mkimage" tool can also be used to create ramdisk images for use
3931 with U-Boot, either separated from the Linux kernel image, or
3932 combined into one file. "mkimage" encapsulates the images with a 64
3933 byte header containing information about target architecture,
3934 operating system, image type, compression method, entry points, time
3935 stamp, CRC32 checksums, etc.
3936
3937 "mkimage" can be called in two ways: to verify existing images and
3938 print the header information, or to build new images.
3939
3940 In the first form (with "-l" option) mkimage lists the information
3941 contained in the header of an existing U-Boot image; this includes
3942 checksum verification:
3943
3944 tools/mkimage -l image
3945 -l ==> list image header information
3946
3947 The second form (with "-d" option) is used to build a U-Boot image
3948 from a "data file" which is used as image payload:
3949
3950 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3951 -n name -d data_file image
3952 -A ==> set architecture to 'arch'
3953 -O ==> set operating system to 'os'
3954 -T ==> set image type to 'type'
3955 -C ==> set compression type 'comp'
3956 -a ==> set load address to 'addr' (hex)
3957 -e ==> set entry point to 'ep' (hex)
3958 -n ==> set image name to 'name'
3959 -d ==> use image data from 'datafile'
3960
3961 Right now, all Linux kernels for PowerPC systems use the same load
3962 address (0x00000000), but the entry point address depends on the
3963 kernel version:
3964
3965 - 2.2.x kernels have the entry point at 0x0000000C,
3966 - 2.3.x and later kernels have the entry point at 0x00000000.
3967
3968 So a typical call to build a U-Boot image would read:
3969
3970 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3971 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3972 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3973 > examples/uImage.TQM850L
3974 Image Name: 2.4.4 kernel for TQM850L
3975 Created: Wed Jul 19 02:34:59 2000
3976 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3977 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3978 Load Address: 0x00000000
3979 Entry Point: 0x00000000
3980
3981 To verify the contents of the image (or check for corruption):
3982
3983 -> tools/mkimage -l examples/uImage.TQM850L
3984 Image Name: 2.4.4 kernel for TQM850L
3985 Created: Wed Jul 19 02:34:59 2000
3986 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3987 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3988 Load Address: 0x00000000
3989 Entry Point: 0x00000000
3990
3991 NOTE: for embedded systems where boot time is critical you can trade
3992 speed for memory and install an UNCOMPRESSED image instead: this
3993 needs more space in Flash, but boots much faster since it does not
3994 need to be uncompressed:
3995
3996 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3997 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3998 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3999 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4000 > examples/uImage.TQM850L-uncompressed
4001 Image Name: 2.4.4 kernel for TQM850L
4002 Created: Wed Jul 19 02:34:59 2000
4003 Image Type: PowerPC Linux Kernel Image (uncompressed)
4004 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4005 Load Address: 0x00000000
4006 Entry Point: 0x00000000
4007
4008
4009 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4010 when your kernel is intended to use an initial ramdisk:
4011
4012 -> tools/mkimage -n 'Simple Ramdisk Image' \
4013 > -A ppc -O linux -T ramdisk -C gzip \
4014 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4015 Image Name: Simple Ramdisk Image
4016 Created: Wed Jan 12 14:01:50 2000
4017 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4018 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4019 Load Address: 0x00000000
4020 Entry Point: 0x00000000
4021
4022
4023 Installing a Linux Image:
4024 -------------------------
4025
4026 To downloading a U-Boot image over the serial (console) interface,
4027 you must convert the image to S-Record format:
4028
4029 objcopy -I binary -O srec examples/image examples/image.srec
4030
4031 The 'objcopy' does not understand the information in the U-Boot
4032 image header, so the resulting S-Record file will be relative to
4033 address 0x00000000. To load it to a given address, you need to
4034 specify the target address as 'offset' parameter with the 'loads'
4035 command.
4036
4037 Example: install the image to address 0x40100000 (which on the
4038 TQM8xxL is in the first Flash bank):
4039
4040 => erase 40100000 401FFFFF
4041
4042 .......... done
4043 Erased 8 sectors
4044
4045 => loads 40100000
4046 ## Ready for S-Record download ...
4047 ~>examples/image.srec
4048 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4049 ...
4050 15989 15990 15991 15992
4051 [file transfer complete]
4052 [connected]
4053 ## Start Addr = 0x00000000
4054
4055
4056 You can check the success of the download using the 'iminfo' command;
4057 this includes a checksum verification so you can be sure no data
4058 corruption happened:
4059
4060 => imi 40100000
4061
4062 ## Checking Image at 40100000 ...
4063 Image Name: 2.2.13 for initrd on TQM850L
4064 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4065 Data Size: 335725 Bytes = 327 kB = 0 MB
4066 Load Address: 00000000
4067 Entry Point: 0000000c
4068 Verifying Checksum ... OK
4069
4070
4071 Boot Linux:
4072 -----------
4073
4074 The "bootm" command is used to boot an application that is stored in
4075 memory (RAM or Flash). In case of a Linux kernel image, the contents
4076 of the "bootargs" environment variable is passed to the kernel as
4077 parameters. You can check and modify this variable using the
4078 "printenv" and "setenv" commands:
4079
4080
4081 => printenv bootargs
4082 bootargs=root=/dev/ram
4083
4084 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4085
4086 => printenv bootargs
4087 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4088
4089 => bootm 40020000
4090 ## Booting Linux kernel at 40020000 ...
4091 Image Name: 2.2.13 for NFS on TQM850L
4092 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4093 Data Size: 381681 Bytes = 372 kB = 0 MB
4094 Load Address: 00000000
4095 Entry Point: 0000000c
4096 Verifying Checksum ... OK
4097 Uncompressing Kernel Image ... OK
4098 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
4099 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4100 time_init: decrementer frequency = 187500000/60
4101 Calibrating delay loop... 49.77 BogoMIPS
4102 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4103 ...
4104
4105 If you want to boot a Linux kernel with initial RAM disk, you pass
4106 the memory addresses of both the kernel and the initrd image (PPBCOOT
4107 format!) to the "bootm" command:
4108
4109 => imi 40100000 40200000
4110
4111 ## Checking Image at 40100000 ...
4112 Image Name: 2.2.13 for initrd on TQM850L
4113 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4114 Data Size: 335725 Bytes = 327 kB = 0 MB
4115 Load Address: 00000000
4116 Entry Point: 0000000c
4117 Verifying Checksum ... OK
4118
4119 ## Checking Image at 40200000 ...
4120 Image Name: Simple Ramdisk Image
4121 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4122 Data Size: 566530 Bytes = 553 kB = 0 MB
4123 Load Address: 00000000
4124 Entry Point: 00000000
4125 Verifying Checksum ... OK
4126
4127 => bootm 40100000 40200000
4128 ## Booting Linux kernel at 40100000 ...
4129 Image Name: 2.2.13 for initrd on TQM850L
4130 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4131 Data Size: 335725 Bytes = 327 kB = 0 MB
4132 Load Address: 00000000
4133 Entry Point: 0000000c
4134 Verifying Checksum ... OK
4135 Uncompressing Kernel Image ... OK
4136 ## Loading RAMDisk Image at 40200000 ...
4137 Image Name: Simple Ramdisk Image
4138 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4139 Data Size: 566530 Bytes = 553 kB = 0 MB
4140 Load Address: 00000000
4141 Entry Point: 00000000
4142 Verifying Checksum ... OK
4143 Loading Ramdisk ... OK
4144 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
4145 Boot arguments: root=/dev/ram
4146 time_init: decrementer frequency = 187500000/60
4147 Calibrating delay loop... 49.77 BogoMIPS
4148 ...
4149 RAMDISK: Compressed image found at block 0
4150 VFS: Mounted root (ext2 filesystem).
4151
4152 bash#
4153
4154 Boot Linux and pass a flat device tree:
4155 -----------
4156
4157 First, U-Boot must be compiled with the appropriate defines. See the section
4158 titled "Linux Kernel Interface" above for a more in depth explanation. The
4159 following is an example of how to start a kernel and pass an updated
4160 flat device tree:
4161
4162 => print oftaddr
4163 oftaddr=0x300000
4164 => print oft
4165 oft=oftrees/mpc8540ads.dtb
4166 => tftp $oftaddr $oft
4167 Speed: 1000, full duplex
4168 Using TSEC0 device
4169 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4170 Filename 'oftrees/mpc8540ads.dtb'.
4171 Load address: 0x300000
4172 Loading: #
4173 done
4174 Bytes transferred = 4106 (100a hex)
4175 => tftp $loadaddr $bootfile
4176 Speed: 1000, full duplex
4177 Using TSEC0 device
4178 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4179 Filename 'uImage'.
4180 Load address: 0x200000
4181 Loading:############
4182 done
4183 Bytes transferred = 1029407 (fb51f hex)
4184 => print loadaddr
4185 loadaddr=200000
4186 => print oftaddr
4187 oftaddr=0x300000
4188 => bootm $loadaddr - $oftaddr
4189 ## Booting image at 00200000 ...
4190 Image Name: Linux-2.6.17-dirty
4191 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4192 Data Size: 1029343 Bytes = 1005.2 kB
4193 Load Address: 00000000
4194 Entry Point: 00000000
4195 Verifying Checksum ... OK
4196 Uncompressing Kernel Image ... OK
4197 Booting using flat device tree at 0x300000
4198 Using MPC85xx ADS machine description
4199 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4200 [snip]
4201
4202
4203 More About U-Boot Image Types:
4204 ------------------------------
4205
4206 U-Boot supports the following image types:
4207
4208 "Standalone Programs" are directly runnable in the environment
4209 provided by U-Boot; it is expected that (if they behave
4210 well) you can continue to work in U-Boot after return from
4211 the Standalone Program.
4212 "OS Kernel Images" are usually images of some Embedded OS which
4213 will take over control completely. Usually these programs
4214 will install their own set of exception handlers, device
4215 drivers, set up the MMU, etc. - this means, that you cannot
4216 expect to re-enter U-Boot except by resetting the CPU.
4217 "RAMDisk Images" are more or less just data blocks, and their
4218 parameters (address, size) are passed to an OS kernel that is
4219 being started.
4220 "Multi-File Images" contain several images, typically an OS
4221 (Linux) kernel image and one or more data images like
4222 RAMDisks. This construct is useful for instance when you want
4223 to boot over the network using BOOTP etc., where the boot
4224 server provides just a single image file, but you want to get
4225 for instance an OS kernel and a RAMDisk image.
4226
4227 "Multi-File Images" start with a list of image sizes, each
4228 image size (in bytes) specified by an "uint32_t" in network
4229 byte order. This list is terminated by an "(uint32_t)0".
4230 Immediately after the terminating 0 follow the images, one by
4231 one, all aligned on "uint32_t" boundaries (size rounded up to
4232 a multiple of 4 bytes).
4233
4234 "Firmware Images" are binary images containing firmware (like
4235 U-Boot or FPGA images) which usually will be programmed to
4236 flash memory.
4237
4238 "Script files" are command sequences that will be executed by
4239 U-Boot's command interpreter; this feature is especially
4240 useful when you configure U-Boot to use a real shell (hush)
4241 as command interpreter.
4242
4243
4244 Standalone HOWTO:
4245 =================
4246
4247 One of the features of U-Boot is that you can dynamically load and
4248 run "standalone" applications, which can use some resources of
4249 U-Boot like console I/O functions or interrupt services.
4250
4251 Two simple examples are included with the sources:
4252
4253 "Hello World" Demo:
4254 -------------------
4255
4256 'examples/hello_world.c' contains a small "Hello World" Demo
4257 application; it is automatically compiled when you build U-Boot.
4258 It's configured to run at address 0x00040004, so you can play with it
4259 like that:
4260
4261 => loads
4262 ## Ready for S-Record download ...
4263 ~>examples/hello_world.srec
4264 1 2 3 4 5 6 7 8 9 10 11 ...
4265 [file transfer complete]
4266 [connected]
4267 ## Start Addr = 0x00040004
4268
4269 => go 40004 Hello World! This is a test.
4270 ## Starting application at 0x00040004 ...
4271 Hello World
4272 argc = 7
4273 argv[0] = "40004"
4274 argv[1] = "Hello"
4275 argv[2] = "World!"
4276 argv[3] = "This"
4277 argv[4] = "is"
4278 argv[5] = "a"
4279 argv[6] = "test."
4280 argv[7] = "<NULL>"
4281 Hit any key to exit ...
4282
4283 ## Application terminated, rc = 0x0
4284
4285 Another example, which demonstrates how to register a CPM interrupt
4286 handler with the U-Boot code, can be found in 'examples/timer.c'.
4287 Here, a CPM timer is set up to generate an interrupt every second.
4288 The interrupt service routine is trivial, just printing a '.'
4289 character, but this is just a demo program. The application can be
4290 controlled by the following keys:
4291
4292 ? - print current values og the CPM Timer registers
4293 b - enable interrupts and start timer
4294 e - stop timer and disable interrupts
4295 q - quit application
4296
4297 => loads
4298 ## Ready for S-Record download ...
4299 ~>examples/timer.srec
4300 1 2 3 4 5 6 7 8 9 10 11 ...
4301 [file transfer complete]
4302 [connected]
4303 ## Start Addr = 0x00040004
4304
4305 => go 40004
4306 ## Starting application at 0x00040004 ...
4307 TIMERS=0xfff00980
4308 Using timer 1
4309 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4310
4311 Hit 'b':
4312 [q, b, e, ?] Set interval 1000000 us
4313 Enabling timer
4314 Hit '?':
4315 [q, b, e, ?] ........
4316 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4317 Hit '?':
4318 [q, b, e, ?] .
4319 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4320 Hit '?':
4321 [q, b, e, ?] .
4322 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4323 Hit '?':
4324 [q, b, e, ?] .
4325 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4326 Hit 'e':
4327 [q, b, e, ?] ...Stopping timer
4328 Hit 'q':
4329 [q, b, e, ?] ## Application terminated, rc = 0x0
4330
4331
4332 Minicom warning:
4333 ================
4334
4335 Over time, many people have reported problems when trying to use the
4336 "minicom" terminal emulation program for serial download. I (wd)
4337 consider minicom to be broken, and recommend not to use it. Under
4338 Unix, I recommend to use C-Kermit for general purpose use (and
4339 especially for kermit binary protocol download ("loadb" command), and
4340 use "cu" for S-Record download ("loads" command).
4341
4342 Nevertheless, if you absolutely want to use it try adding this
4343 configuration to your "File transfer protocols" section:
4344
4345 Name Program Name U/D FullScr IO-Red. Multi
4346 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4347 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4348
4349
4350 NetBSD Notes:
4351 =============
4352
4353 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4354 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4355
4356 Building requires a cross environment; it is known to work on
4357 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4358 need gmake since the Makefiles are not compatible with BSD make).
4359 Note that the cross-powerpc package does not install include files;
4360 attempting to build U-Boot will fail because <machine/ansi.h> is
4361 missing. This file has to be installed and patched manually:
4362
4363 # cd /usr/pkg/cross/powerpc-netbsd/include
4364 # mkdir powerpc
4365 # ln -s powerpc machine
4366 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4367 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4368
4369 Native builds *don't* work due to incompatibilities between native
4370 and U-Boot include files.
4371
4372 Booting assumes that (the first part of) the image booted is a
4373 stage-2 loader which in turn loads and then invokes the kernel
4374 proper. Loader sources will eventually appear in the NetBSD source
4375 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4376 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4377
4378
4379 Implementation Internals:
4380 =========================
4381
4382 The following is not intended to be a complete description of every
4383 implementation detail. However, it should help to understand the
4384 inner workings of U-Boot and make it easier to port it to custom
4385 hardware.
4386
4387
4388 Initial Stack, Global Data:
4389 ---------------------------
4390
4391 The implementation of U-Boot is complicated by the fact that U-Boot
4392 starts running out of ROM (flash memory), usually without access to
4393 system RAM (because the memory controller is not initialized yet).
4394 This means that we don't have writable Data or BSS segments, and BSS
4395 is not initialized as zero. To be able to get a C environment working
4396 at all, we have to allocate at least a minimal stack. Implementation
4397 options for this are defined and restricted by the CPU used: Some CPU
4398 models provide on-chip memory (like the IMMR area on MPC8xx and
4399 MPC826x processors), on others (parts of) the data cache can be
4400 locked as (mis-) used as memory, etc.
4401
4402 Chris Hallinan posted a good summary of these issues to the
4403 U-Boot mailing list:
4404
4405 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4406 From: "Chris Hallinan" <clh@net1plus.com>
4407 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4408 ...
4409
4410 Correct me if I'm wrong, folks, but the way I understand it
4411 is this: Using DCACHE as initial RAM for Stack, etc, does not
4412 require any physical RAM backing up the cache. The cleverness
4413 is that the cache is being used as a temporary supply of
4414 necessary storage before the SDRAM controller is setup. It's
4415 beyond the scope of this list to explain the details, but you
4416 can see how this works by studying the cache architecture and
4417 operation in the architecture and processor-specific manuals.
4418
4419 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4420 is another option for the system designer to use as an
4421 initial stack/RAM area prior to SDRAM being available. Either
4422 option should work for you. Using CS 4 should be fine if your
4423 board designers haven't used it for something that would
4424 cause you grief during the initial boot! It is frequently not
4425 used.
4426
4427 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4428 with your processor/board/system design. The default value
4429 you will find in any recent u-boot distribution in
4430 walnut.h should work for you. I'd set it to a value larger
4431 than your SDRAM module. If you have a 64MB SDRAM module, set
4432 it above 400_0000. Just make sure your board has no resources
4433 that are supposed to respond to that address! That code in
4434 start.S has been around a while and should work as is when
4435 you get the config right.
4436
4437 -Chris Hallinan
4438 DS4.COM, Inc.
4439
4440 It is essential to remember this, since it has some impact on the C
4441 code for the initialization procedures:
4442
4443 * Initialized global data (data segment) is read-only. Do not attempt
4444 to write it.
4445
4446 * Do not use any uninitialized global data (or implicitely initialized
4447 as zero data - BSS segment) at all - this is undefined, initiali-
4448 zation is performed later (when relocating to RAM).
4449
4450 * Stack space is very limited. Avoid big data buffers or things like
4451 that.
4452
4453 Having only the stack as writable memory limits means we cannot use
4454 normal global data to share information beween the code. But it
4455 turned out that the implementation of U-Boot can be greatly
4456 simplified by making a global data structure (gd_t) available to all
4457 functions. We could pass a pointer to this data as argument to _all_
4458 functions, but this would bloat the code. Instead we use a feature of
4459 the GCC compiler (Global Register Variables) to share the data: we
4460 place a pointer (gd) to the global data into a register which we
4461 reserve for this purpose.
4462
4463 When choosing a register for such a purpose we are restricted by the
4464 relevant (E)ABI specifications for the current architecture, and by
4465 GCC's implementation.
4466
4467 For PowerPC, the following registers have specific use:
4468 R1: stack pointer
4469 R2: reserved for system use
4470 R3-R4: parameter passing and return values
4471 R5-R10: parameter passing
4472 R13: small data area pointer
4473 R30: GOT pointer
4474 R31: frame pointer
4475
4476 (U-Boot also uses R12 as internal GOT pointer. r12
4477 is a volatile register so r12 needs to be reset when
4478 going back and forth between asm and C)
4479
4480 ==> U-Boot will use R2 to hold a pointer to the global data
4481
4482 Note: on PPC, we could use a static initializer (since the
4483 address of the global data structure is known at compile time),
4484 but it turned out that reserving a register results in somewhat
4485 smaller code - although the code savings are not that big (on
4486 average for all boards 752 bytes for the whole U-Boot image,
4487 624 text + 127 data).
4488
4489 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4490 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4491
4492 ==> U-Boot will use P3 to hold a pointer to the global data
4493
4494 On ARM, the following registers are used:
4495
4496 R0: function argument word/integer result
4497 R1-R3: function argument word
4498 R9: GOT pointer
4499 R10: stack limit (used only if stack checking if enabled)
4500 R11: argument (frame) pointer
4501 R12: temporary workspace
4502 R13: stack pointer
4503 R14: link register
4504 R15: program counter
4505
4506 ==> U-Boot will use R8 to hold a pointer to the global data
4507
4508 On Nios II, the ABI is documented here:
4509 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4510
4511 ==> U-Boot will use gp to hold a pointer to the global data
4512
4513 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4514 to access small data sections, so gp is free.
4515
4516 On NDS32, the following registers are used:
4517
4518 R0-R1: argument/return
4519 R2-R5: argument
4520 R15: temporary register for assembler
4521 R16: trampoline register
4522 R28: frame pointer (FP)
4523 R29: global pointer (GP)
4524 R30: link register (LP)
4525 R31: stack pointer (SP)
4526 PC: program counter (PC)
4527
4528 ==> U-Boot will use R10 to hold a pointer to the global data
4529
4530 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4531 or current versions of GCC may "optimize" the code too much.
4532
4533 Memory Management:
4534 ------------------
4535
4536 U-Boot runs in system state and uses physical addresses, i.e. the
4537 MMU is not used either for address mapping nor for memory protection.
4538
4539 The available memory is mapped to fixed addresses using the memory
4540 controller. In this process, a contiguous block is formed for each
4541 memory type (Flash, SDRAM, SRAM), even when it consists of several
4542 physical memory banks.
4543
4544 U-Boot is installed in the first 128 kB of the first Flash bank (on
4545 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4546 booting and sizing and initializing DRAM, the code relocates itself
4547 to the upper end of DRAM. Immediately below the U-Boot code some
4548 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4549 configuration setting]. Below that, a structure with global Board
4550 Info data is placed, followed by the stack (growing downward).
4551
4552 Additionally, some exception handler code is copied to the low 8 kB
4553 of DRAM (0x00000000 ... 0x00001FFF).
4554
4555 So a typical memory configuration with 16 MB of DRAM could look like
4556 this:
4557
4558 0x0000 0000 Exception Vector code
4559 :
4560 0x0000 1FFF
4561 0x0000 2000 Free for Application Use
4562 :
4563 :
4564
4565 :
4566 :
4567 0x00FB FF20 Monitor Stack (Growing downward)
4568 0x00FB FFAC Board Info Data and permanent copy of global data
4569 0x00FC 0000 Malloc Arena
4570 :
4571 0x00FD FFFF
4572 0x00FE 0000 RAM Copy of Monitor Code
4573 ... eventually: LCD or video framebuffer
4574 ... eventually: pRAM (Protected RAM - unchanged by reset)
4575 0x00FF FFFF [End of RAM]
4576
4577
4578 System Initialization:
4579 ----------------------
4580
4581 In the reset configuration, U-Boot starts at the reset entry point
4582 (on most PowerPC systems at address 0x00000100). Because of the reset
4583 configuration for CS0# this is a mirror of the onboard Flash memory.
4584 To be able to re-map memory U-Boot then jumps to its link address.
4585 To be able to implement the initialization code in C, a (small!)
4586 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4587 which provide such a feature like MPC8xx or MPC8260), or in a locked
4588 part of the data cache. After that, U-Boot initializes the CPU core,
4589 the caches and the SIU.
4590
4591 Next, all (potentially) available memory banks are mapped using a
4592 preliminary mapping. For example, we put them on 512 MB boundaries
4593 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4594 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4595 programmed for SDRAM access. Using the temporary configuration, a
4596 simple memory test is run that determines the size of the SDRAM
4597 banks.
4598
4599 When there is more than one SDRAM bank, and the banks are of
4600 different size, the largest is mapped first. For equal size, the first
4601 bank (CS2#) is mapped first. The first mapping is always for address
4602 0x00000000, with any additional banks following immediately to create
4603 contiguous memory starting from 0.
4604
4605 Then, the monitor installs itself at the upper end of the SDRAM area
4606 and allocates memory for use by malloc() and for the global Board
4607 Info data; also, the exception vector code is copied to the low RAM
4608 pages, and the final stack is set up.
4609
4610 Only after this relocation will you have a "normal" C environment;
4611 until that you are restricted in several ways, mostly because you are
4612 running from ROM, and because the code will have to be relocated to a
4613 new address in RAM.
4614
4615
4616 U-Boot Porting Guide:
4617 ----------------------
4618
4619 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4620 list, October 2002]
4621
4622
4623 int main(int argc, char *argv[])
4624 {
4625 sighandler_t no_more_time;
4626
4627 signal(SIGALRM, no_more_time);
4628 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4629
4630 if (available_money > available_manpower) {
4631 Pay consultant to port U-Boot;
4632 return 0;
4633 }
4634
4635 Download latest U-Boot source;
4636
4637 Subscribe to u-boot mailing list;
4638
4639 if (clueless)
4640 email("Hi, I am new to U-Boot, how do I get started?");
4641
4642 while (learning) {
4643 Read the README file in the top level directory;
4644 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4645 Read applicable doc/*.README;
4646 Read the source, Luke;
4647 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4648 }
4649
4650 if (available_money > toLocalCurrency ($2500))
4651 Buy a BDI3000;
4652 else
4653 Add a lot of aggravation and time;
4654
4655 if (a similar board exists) { /* hopefully... */
4656 cp -a board/<similar> board/<myboard>
4657 cp include/configs/<similar>.h include/configs/<myboard>.h
4658 } else {
4659 Create your own board support subdirectory;
4660 Create your own board include/configs/<myboard>.h file;
4661 }
4662 Edit new board/<myboard> files
4663 Edit new include/configs/<myboard>.h
4664
4665 while (!accepted) {
4666 while (!running) {
4667 do {
4668 Add / modify source code;
4669 } until (compiles);
4670 Debug;
4671 if (clueless)
4672 email("Hi, I am having problems...");
4673 }
4674 Send patch file to the U-Boot email list;
4675 if (reasonable critiques)
4676 Incorporate improvements from email list code review;
4677 else
4678 Defend code as written;
4679 }
4680
4681 return 0;
4682 }
4683
4684 void no_more_time (int sig)
4685 {
4686 hire_a_guru();
4687 }
4688
4689
4690 Coding Standards:
4691 -----------------
4692
4693 All contributions to U-Boot should conform to the Linux kernel
4694 coding style; see the file "Documentation/CodingStyle" and the script
4695 "scripts/Lindent" in your Linux kernel source directory.
4696
4697 Source files originating from a different project (for example the
4698 MTD subsystem) are generally exempt from these guidelines and are not
4699 reformated to ease subsequent migration to newer versions of those
4700 sources.
4701
4702 Please note that U-Boot is implemented in C (and to some small parts in
4703 Assembler); no C++ is used, so please do not use C++ style comments (//)
4704 in your code.
4705
4706 Please also stick to the following formatting rules:
4707 - remove any trailing white space
4708 - use TAB characters for indentation and vertical alignment, not spaces
4709 - make sure NOT to use DOS '\r\n' line feeds
4710 - do not add more than 2 consecutive empty lines to source files
4711 - do not add trailing empty lines to source files
4712
4713 Submissions which do not conform to the standards may be returned
4714 with a request to reformat the changes.
4715
4716
4717 Submitting Patches:
4718 -------------------
4719
4720 Since the number of patches for U-Boot is growing, we need to
4721 establish some rules. Submissions which do not conform to these rules
4722 may be rejected, even when they contain important and valuable stuff.
4723
4724 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4725
4726 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4727 see http://lists.denx.de/mailman/listinfo/u-boot
4728
4729 When you send a patch, please include the following information with
4730 it:
4731
4732 * For bug fixes: a description of the bug and how your patch fixes
4733 this bug. Please try to include a way of demonstrating that the
4734 patch actually fixes something.
4735
4736 * For new features: a description of the feature and your
4737 implementation.
4738
4739 * A CHANGELOG entry as plaintext (separate from the patch)
4740
4741 * For major contributions, your entry to the CREDITS file
4742
4743 * When you add support for a new board, don't forget to add this
4744 board to the MAINTAINERS file, too.
4745
4746 * If your patch adds new configuration options, don't forget to
4747 document these in the README file.
4748
4749 * The patch itself. If you are using git (which is *strongly*
4750 recommended) you can easily generate the patch using the
4751 "git format-patch". If you then use "git send-email" to send it to
4752 the U-Boot mailing list, you will avoid most of the common problems
4753 with some other mail clients.
4754
4755 If you cannot use git, use "diff -purN OLD NEW". If your version of
4756 diff does not support these options, then get the latest version of
4757 GNU diff.
4758
4759 The current directory when running this command shall be the parent
4760 directory of the U-Boot source tree (i. e. please make sure that
4761 your patch includes sufficient directory information for the
4762 affected files).
4763
4764 We prefer patches as plain text. MIME attachments are discouraged,
4765 and compressed attachments must not be used.
4766
4767 * If one logical set of modifications affects or creates several
4768 files, all these changes shall be submitted in a SINGLE patch file.
4769
4770 * Changesets that contain different, unrelated modifications shall be
4771 submitted as SEPARATE patches, one patch per changeset.
4772
4773
4774 Notes:
4775
4776 * Before sending the patch, run the MAKEALL script on your patched
4777 source tree and make sure that no errors or warnings are reported
4778 for any of the boards.
4779
4780 * Keep your modifications to the necessary minimum: A patch
4781 containing several unrelated changes or arbitrary reformats will be
4782 returned with a request to re-formatting / split it.
4783
4784 * If you modify existing code, make sure that your new code does not
4785 add to the memory footprint of the code ;-) Small is beautiful!
4786 When adding new features, these should compile conditionally only
4787 (using #ifdef), and the resulting code with the new feature
4788 disabled must not need more memory than the old code without your
4789 modification.
4790
4791 * Remember that there is a size limit of 100 kB per message on the
4792 u-boot mailing list. Bigger patches will be moderated. If they are
4793 reasonable and not too big, they will be acknowledged. But patches
4794 bigger than the size limit should be avoided.